Book of Abstracts

Transcription

Book of Abstracts

14th International Balkan Workshop on
Applied Physics
Constanţa, Romania, July 2-4, 2014
Book of Abstracts
Editors:
Marius BELC, Mihai GÎRȚU
Iuliana M. STĂNESCU
Constanţa, 2014
14th International Balkan Workshop on Applied
Physics
Is jointly organized by:
OVIDIUS UNIVERSITY OF CONSTANTA
in cooperation with:
BALKAN PHYSICAL UNION
ROMANIAN PHYSICAL SOCIETY
under the patronage of:
MINISTRY OF EDUCATION, RESEARCH, YOUTH AND SPORTS
Chairpersons:
Marius Belc
Department Chair,Ovidius University- Constanta
Mihai Gîrțu
President, Rom.Phys.Soc.-Constanta
Yesim Oktem
President, Balkan Physical Union
Nicolae V. Zamfir
President, Romanian Physical Society
International Organizing Committee
Goran Djordjević (vicepresident of BPU),
Athanasios Lambros (General Secretary of BPU),
Radu Constantinescu (Scientific Secretary of BPU),
Nicholai Tonchev (Scientific Project Coordinator of BPU),
Baki Akkus (Turkish Physical Society),
Angelos Angelopoulos (Hellenic Physical Society),
Emil Burzo (Romanian Physical Society and Romanian Academy of Science),
Damyan N. Damyanov (Union of Scientists in Bulgaria),
Antoneta Deda (Albanian Physical Society),
Stavros Ioannou (Physical Society of Cyprus),
Valeriu Kantser (Moldovian Physical Society),
Predrac Miranovic (Physical Society of Montenegro),
Zenun Mulaj (Albanian Physical Society),
Alexander Petrov (Bulgarian Physical Society),
E. Polychroniadis (Hellenic Physical Society)
Local Organizing Committee
Viorica Popescu, Ovidius University
Rodica Vladoiu, Ovidius University
Iuliana M. Stănescu, Ovidius University
Aurelia Mandeș, Ovidius University
Mirela Conțulov, Ovidius University
Virginia Dincă, Ovidius University
Madalina Prodan, Ovidius University
Gabriel Prodan, Ovidius University
Florin Moscalu, Ovidius University
Corneliu I Oprea, Ovidius University
Jeanina Lungu, Ovidius University
Constanța Ștefanov, Ovidius University
Petre Panait, Ovidius University
Daniela Stamate, Ovidius University
Viorel Ionescu, Ovidius University
Advisory Committee
Nafiye Gunec Kiyak (Turkey)
Horia Alexandru (Romania)
Dragana Krstić (Serbia)
Alexandru Aldea (Romania)
I. Lalov (Bulgaria)
Stefan Antohe (Romania)
Dumitru Luca (Romania)
Simion Astilean (Romania)
Cristian P. Lungu (Romania)
Metin Arik (Turkey)
Ion Malaescu (Romania)
Pervin Arikan (Turkey)
Ion N. Mihailescu (Romania)
Nicolae Avram (Romania)
Pedja Mihailović (Serbia)
Dimiter Balabanski (Bulgaria)
A. Minxhozi (Albania)
Antun Balaž (Serbia)
Ioan Morjan (Romania)
Virgil Baran (Romania)
Ibrahim Halil Mutlu (Turkey)
Ibrahim Belenli (Turkey)
Christo Nanev (Bulgaria)
P. Berberi (Albania)
Ljubiša Nešić (Serbia)
Dj. Bek-Uzarov (Serbia)
Alexandru Nicolin (Romania)
Aleksandar Bogojević (Serbia)
Dragoslav Nikezić (Serbia)
Dennis Bonatsos (Greece)
Milica Pavkov-Hrvojević (Serbia)
Madalin Bunoiu (Romania)
Lucian Pintilie (Romania)
Emil Burzo (Romania)
E. Polychroniadis (Greece)
Gheorghe Cata-Danil (Romania)
Viorel Pop (Romania)
Gabriela Carja (Romania)
Gheorghe Popa (Romania)
Gheorghe V. Cimpoca (Romania)
Ion V. Popescu (Romania)
Victor Ciupina (Romania)
Mihai Popescu (Romania)
Horia Chiriac (Romania)
Goran Ristić (Serbia)
Onuc Cozar (Romania)
Gheorghe Samoilescu (Romania)
Vladimir Cvjetković (Serbia)
Roman Schrittwieser (Austria)
Dragoljub Dimitrijević (Serbia)
Simion Simon (Romania)
Maria Dinescu (Romania)
Alexandru Stancu (Romania)
Ivan Dojčinović (Serbia)
Darko Tanasković (Serbia)
Mahmut Dogru (Turkey)
Cristian Teodorescu (Romania)
Branko Dragovic (Serbia)
Mihai Toma (Romania)
Miroljub Dugić(Serbia)
N. Tonchev (Bulgaria)
Mustafa Erol (Turkey)
Valentin Urumov (Macedonia)
Mats Fahlman (Sweden)
E. Valcheva (Bulgaria)
Mihai Gîrţu (Romania)
Miroslav Vesković (Serbia)
A. Georgieva (Bulgaria)
Valentin Vlad (Romania)
Constantin Grigoriu (Romania)
Rodica Vladoiu (Romania)
Husnu Salih Guder (Turkey)
Mihai Visinescu (Romania)
Dan Grecu (Romania)
Daniel Vizman (Romania)
Felicia Iacomi (Romania)
Dumitru Vulcanov (Romania)
Alexandru Jipa (Romania)
Latife Sahin Yalcin (Turkey)
Wilhelm Kappel (Romania)
Ch. Zerefos (Greece)
Topics:
1.
Materials Physics
Semiconductors, Dielectrics and Organic Materials
Spintronics, Magnetism and Superconductivity
Crystal growth, Surfaces, Interfaces and Thin Films
Polymers and Amorphous Materials
2.
Laser, Plasma and Radiation Physics and Applications
Laser Physics and applications
Plasma Physics and applications
Optoelectronics and photonics
Applied and non-linear optics
Ultrafast phenomena and applications
3.
Nuclear and sub-Nuclear Physics and Applications
Nuclear and subnuclear sciences and Engineering
Advanced detection systems
Accelerated particle beams
Nuclear Techniques and applications
Nuclear Safety and Radiation Protection
4.
Cross-disciplinary Applications of Physics
Nonlinear dynamics, complex systems and applications
Biological complexity and Genetics
Econophysics
Physics of Social System
5.
Engineering and Industrial Physics
Physics of energy transfer, conversion and storage
Environmental Physics
Sensors and Device Physics
Micro- and Nanoelectronics
Microelectromechanical systems
Instrumentation and Metrology
Imagining, Microscopy and Spectroscopy and their applications
Instrumentation, processing, fabrication and measurement technologies
Applications of fluid mechanics and microfluidics
6.
Topics in Physics Education Research
Physics curriculum design
Active learning techniques
Classroom teaching, demonstrations and laboratory experiments
14th International Balkan Workshop on Applied Physics
6
Plenary Session
S0 01
Ce:(Y1-xLux)3Al5O12 SINGLE CRYSTAL PHOSPHORS FOR HIGH-BRIGHTNESS WHITE LEDS
K. SHIMAMURA, E.G. VÍLLORA, S. ARJOCA, D. INOMATA, K. AOKI, J. HAYASHI
S0 02
INTERFACE PHENOMENA IN ORGANIC ELECTRONICS
MATS FAHLMAN
S0 03
GIANT MICRO-PHOTONICS FOR FUTURE ENERGY
Takunori TAIRA
S0 04
NUCLEAR PHYSICS AND APPLICATIONS AT ELI–NP
Calin Alexandru UR
S0 05
VORTEX CONFIGURATIONS IN BOSE-EINSTEIN CONDENSATES: FROM THE QUANTUM
SPIROGRAPH TO VORTEX LATTICES
Ricardo CARRETERO-GONZALEZ
S0 06
THE CENTRE FOR ADVANCED LASER TEHNOLOGIES (CETAL)
Constantin GRIGORIU, Constantin FENIC, Dan SPOREA, Catalin TICOS, Ion MORJAN
Section 1 Materials Physics
S1 L01
ADDRESSING PROPERTIES OF MORPHOLOGICALLY COMPLEX MATERIALS AND NANOSTRUCTURES USING SYNCHROTRON BASED PHOTOELECTRON MICROSCOPY
Maya KISKINOVA
S1 L02
FIRST-PRINCIPLES SIMULATIONS OF PLATINUM AND PALLADIUM CATALYSTS UNDER
OXYGEN-RICH CONDITIONS
Nicola SERIANI
S1 L03
EFFECTS OF IONIZING RADIATIONS ON THE PERFORMANCES OF CdS/CdTe SOLAR CELLS
Ştefan ANTOHE
S1 L04
GRAPHENE: FACTS AND FICTIONS
Ali EFTEKHARI
S1 L05
FUNDAMENTAL ASPECTS IN SOLUTION GROWTH OF NONLINEAR TETRAGONAL
CRYSTALS
Horia V. ALEXANDRU
S1 L06
RECENT DEVELOPMENT OF RARE EARTH LEAN PERMANENT MAGNETS
V. POP
7
S1 L07
CHEMISTRY AND PHOTOCHEMISTRY AT FERROELECTRIC SURFACES
Cristian-Mihail TEODORESCU
S1 L08
ANALYTICAL SOLUTIONS OF EIGENENERGY EQUATIONS OF QUANTUM PARTICLES WITH
APPLICATIONS TO NANOPHYSICS
Victor BARSAN
S1 L09
ENHANCING THE PLASTICITY OF METALLIC GLASSES: NANOCOMPOSITES AND
NANOGLASSES INVESTIGATED BY MOLECULAR DYNAMIC SIMULATIONS
Daniel ŞOPU, Karsten ALBE
S1 L10
FABRICATION OF ONE-DIMENSIONAL ZINC OXIDE NANOSTRUCTURES USING TEMPLATEFREE ELECTROCHEMICAL PATHWAYS
Vlad-Andrei ANTOHE, and Luc PIRAUX
S1 L11
EFFECTIVE SEGREGATION COEFFICIENT OF RARE-EARTH IONS IN FLUORITE CRYSTALS
Madalin BUNOIU, Marius STEF and Irina NICOARA
S1 L12
ELECTROCHEMICAL DEPOSITION OF ORGANOMETALLIC/POLYPYRROLE
COMPOSITES FOR OLED APPLICATIONS
S. POLOSAN
S1 L13
SENSOR ARRAY FABRICATION BY LASER-INDUCED FORWARD TRANSFER
A. PALLA PAPAVLU, T. LIPPERT, M. DINESCU
S1 L14
THE EFFECT OF THE SUBSTRATE TEMPERATURE AND THE ACCELERATION POTENTIAL
DROP ON THE STRUCTURAL AND PHYSICAL
PROPERTIES OF SiC THIN FILMS DEPOSED BY TVA METHOD
V.CIUPINĂ, G.PRODAN, , R.VLĂDOIU, C.P. POROŞNICU , E.VASILE, C.P.LUNGU, M.BELC,
I.M.OANCEA-STANESCU , V.DINCA, A.MANDES, V.NICOLESCU
S1 L15
RECENT STUDIES ON SOME IRON OXIDE NANOCOMPOSITES AND THIN FILMS
F. IACOMI
S1 L16
PRESSURE EFFECTS ON THE MAGNETIC BEHAVIOUR OF COBALT IN RARE-EARTH
COMPOUNDS
E. BURZO, P. VLAIC, D. KOZLENKO
S1 L17
EXCITATIONS OF A SHIBA MOLECULE
N. Y. YAO, C. P. MOCA, I. WEYMANN, J. D. SAU, M. D. LUKIN, E. A. DEMLER, G. ZARAND
S1 L18
MATRIX-ASSISTED PULSED LASER EVAPORATION: APPLICATION TO BIOPOLYMER THIN
FILM ASSEMBLIES
C. RISTOSCU, F. SIMA, E. AXENTE, L. E. SIMA, M. ERGINER, M. S. EROGLU, N. MIHAILESCU, S. M.
PETRESCU, E. TOKSOY ONER, I. N. MIHAILESCU
8
S1 O01
W-Mg ALLOY FILMS DEPOSITED by TVA on HYDROGENATED EUROFER SUBSTRATES for
PLASMA FACING COMPONENTS
Simona G. GRECULEASA, P. PALADE, G. SCHINTEIE, A. KUNCSER, A. LUNGU, C. POROSNICU, I.
JEPU, C.P. LUNGU, G. FILOTI, V. KUNCSER
S1 O02
Ba1-xSrxTiO3 FERROELECTRIC SOLID SOLUTIONS OF HIGH TECHNOLOGICAL IMPORTANCE
Liviu NEDELCU, Raluca BACSEI, Nicoleta VINETICU, Sorin Ion JINGA, Radu MANU , Constantin Paul
GANEA, Horia V. ALEXANDU
S1 O03
MAGNETIC RELAXATION IN FERROFLUIDS WITH DIFFERENT VOLUME FRACTIONS OF
MAGNETITE.
G. SCHINTEIE, P. PALADE, N. IACOB, L. VEKAS and V. KUNCSER
S1 P01
MORPHOLOGICAL AND COMPOSITINAL INVESTIGATIONS OF THE TRIBOLOGICAL
COATINGS WITH TERNARY COMPOSITION FROM COMPOUND MATERIALS, OBTAINED BY
DC MAGNGNETRON SPUTTERING DEPOSITION METHOD
A. O. MATEESCU, G. MATEESCU, L. CRACIUN, C. IONESCU, I. BURDUCEA
S1 P02
MECANICAL AND TRIBOLOGICAL BEHAVIOUR OF THE MULTILAYER DRY LUBRICANT
COATINGS WITH TERNARY COMPOSITION FROM COMPOUND MATERIALS
(TixNy; TiB2/ TixByNz; WC/ WxCyNz)
A. O. MATEESCU, G. MATEESCU, L. CRACIUN, C. IONESCU, C. SAMOILA, D. URSUTIU, D.
MUNTEANU, D. CRISTEA, V. JINGA
S1 P03
AN AFM AND SEM STUDY OF SOME DENTAL RESTORATIVE MATERIALS
CHICEA Dan, BOŢA Gabriela, CHICEA Liana-Maria, CHICEA Radu, ŞTEF Laura
S1 P04
PARAMETRIC MODELING OF FIRST-ORDER PHASE TRANSITIONS IN THE PRESENCE OF AN
INTERMEDIATE METASTABLE STATE
Ghennadii GUBCEAC, Florentin PALADI
S1 P05
SYNTHESIS AND CHARACTERIZATION OF SOME MAGNETIC NANO-WIRES BY USING
ANODIZED ALUMINA SHEET AS TEMPLATE
Daniela RUSU, Alina CANTARAGIU, Constantin GHEORGHIES, Antoaneta ENE , Nistor NICUSOR
S1 P06
FIRST PRINCIPLES INVESTIGATIONS ON THE HALF-METALLIC PROPERTIES OF THE NEW
FULL-HEUSLER COMPOUND Co2YSb
Anca BIRSAN, Petru PALADE, Victor KUNCSER
S1 P07
TERAHERTZ TIME-DOMAIN SPECTROSCOPY INVESTIGATIONS ON BULK AND FILM
MICROWAVE DIELECTRICS
M. G. BANCIU, L. NEDELCU, C. CHIRILA, D. GEAMBAŞU , T. FURUYA and M. TANI
S1 P08
NEW APPROACHES FOR TUNING SPECIFIC ABSORPTION RATES IN MAGNETIC FLUID
HYPERTHERMIA
N. IACOB, G. SCHINTEIE, D. TOADER, L. VEKAS and V. KUNCSER
9
S1 P09
MONTE CARLO TYPE INVESTIGATIONS ON THE NUCLEATION PROCESSES IN SOFT
MATTER SYSTEMS
C. BERLIC, V. BARNA, B. MANOLESCU and BEATRICE MAHLER
S1 P10
NEW TYPES OF CONDUCTIVE LEAD GLASS WITH POTENTIAL APPLICATIONS AS
ELECTRODES FOR BATTERIES
Liviu BOLUNDUŢ, Eugen CULEA, Loredana RUS, Maria Elena PICĂ, Mioara ZAGRAI, Simona RADA
S1 P11
STRUCTURE AND SPECTROSCOPIC PROPERTIES OF THE EUROPIUM-SILVER-LEADGERMANATE GLASSES
Ciprian BULZ, Eugen CULEA, Simona RADA
S1 P12
ELECTROCHEMICAL CHARACTERIZATION AND STRUCTURE OF LEAD-GERMANATE
GLASSES DOPING WITH LI2CO3, MOO3, WO3 AND BI2O3
Mioara ZAGRAI, Elena Maria PICĂ, Eugen CULEA, Liviu BOLUNDUŢ, Loredana RUS, Simona RADA,
Petru PĂŞCUŢĂ
S1 P13
ELECTRODES BASED ON LEAD GLASSES AND VITROCERAMICS FOR RECHARGEABLE
BATTERIES
Loredana RUS, Eugen CULEA, Tiberiu RUSU, Simona RADA, Mioara ZAGRAI, Nicolae DURA, Marius
RADA
S1 P14
NANOCRYSTALLIZATION KINETICS OF Al85Co5Ni5Y5 METALLIC GLASS
BARIS Avar, MUSA Gogebakan
S1 P15
INVESTIGATION OF STRUCTURAL, THERMAL AND MAGNETIC PROPERTIES OF
NANOCRYSTALLINE Co65W5Ti25B5 POWDERS BY MECHANICAL ALLOYING
BARIS Avar, SADAN Ozcan
S1 P16
MAGNETRON RF SPUTTERING OF INDIUM PHOSPHID FOR TERAHERTZ APPLICATION
L. SIRBU, A. IONESCU A. BARACU, A. VOICULESCU
S1 P17
FUNCTIONAL PROPERTIES OF GRAPHITE-DERIVED POROUS BaSrTiO3 CERAMICS
R. STANCULESCU, C. E. CIOMAGA, C. GALASSI, L. MITOSERIU,
S1 P18
IMPEDANCE SPECTROSCOPY OF SOME MANGANESE FERRITE POWDERS
I. MALAESCU, A. LUNGU, C. N. MARIN, P. VLAZAN, P. SFARLOAGA
S1 P19
SYNTHESIS AND CHARACTERIZATION OF MANGANESE FERRITES NANOPOWDERS
Vasilica GAFTON, Ioan DUMITRU, Valentin NICA, Ovidiu F CALTUN, Adrian BORHAN, Andrei
DIACONU, Irina V VARARU , Alexandra R IORDAN, Mircea N PALAMARU
S1 P20
STRUCTURAL PROPERTIES OF Sm-Co THIN FILMS
I. STANCIU, A. TAKACS, S. MICAN, D. BENEA and V. POP
S1 P21
STRUCTURAL AND ANTIBACTERIAL PROPERTIES OF Ni DOPED ZNO NANOPOWDERS
EDA ÇİNAR AVAR, BARIŞ AVAR, ELIF LOĞOĞLU
10
S1 P22
POROUS COPPER MINI-PLATES – A POSSIBLE CANDIDATE FOR GDL IN PEM FUEL CELLS
Cristina Mihaela SIMA, Victor CIUPINA, Gabriel PRODAN
S1 P23
CONTRIBUTIONS IN THE OPTIMIZATION OF THE ELECTRON DIFFRACTION PRECESSION
SYSTEM FOR THE EXAMINATION OF THIN FILMS
V. CIUPINĂ, G. PRODAN, R. MANU, Ş.G. TUTUN, L. PETRĂŞESCU, N. VINETICU, O.
BRÎNCOVEANU , I. PRIOTEASA.
S1 P24
LOOKING FOR IN BASED ACTIVE LAYER INTERFACE ON CLEAVED GAAS(100) SURFACE
C.C.NEGRILA, R.V.GHITA, C.LOGOFATU, C.COTIRLAN, F.FRUMOSU, M.F.LAZARESCU
S1 P25
EFFECT OF Li, Cu AND N DOPING ON THE MORPHOLOGY, OPTICAL AND ELECTRICAL
PROPERTIES OF ZnO THIN FILMS PREPARED BY SPIN-COATING TECHNIQUE
A. DANCIU, I. MIHALACHE, B. BITA, R. PLUGARU*
S1 P26
ZNO-BASED STRUCTURES: FROM POWDERS TO HIGH QUALITY THIN FILMS
L.M. TRINCA, A.C. GALCA, C. CHIRILA, C. BESLEAGA, L. PINTILIE
S1 P27
THE ROLE OF Sc IONS ON THE MAGNETIC AND CATALYTIC PROPERTIES OF Co- Ni
NANOFERRITE
C. DOROFTEI, P.D. POPA, E. REZLESCU, N. REZLESCU
S1 P28
NEW PROSPECTS FOR PERMEABLE THERMOELEMENTS APPLICATION
Radion CHERKEZ
S1 P29
THERMALLY TREATED CuCoFe THIN FILMS OBTAINED BY TVA METHOD
V.CIUPINĂ, I.PRIOTEASA, Ş.G.TUTUN, L.PETRĂŞESCU, C.P. POROSNICU , I.MUSTATA,
C.P.LUNGU , E.VASILE , G.SCHINTEIE
S1 P30
CARBON – PLATINUM NANOSTRUCTURED CATALYSTS FOR HYDROGEN FUEL CELLS
V.CIUPINĂ, R.VLĂDOIU, G.PRODAN, L.PETRĂŞESCU, Ş.G.TUTUN, C.P. POROŞNICU , E.VASILE,
I.PRIOTEASA, R. MANU
S1 P31
APPLICATION OF SOME CARBON-ALUMINIUM BASED NANOSTRUCTURES IN DIVERTORS
COATING FROM FUSION REACTOR
V.CIUPINĂ, R.VLĂDOIU, G.PRODAN, Ş.G.TUTUN , L.PETRĂŞESCU, C.P. POROŞNICU , E.VASILE, I.
PRIOTEASA, R. MANU
S1 P32
CAVITY RING-DOWN SPECTROSCOPY MEASUREMENTS ON HYDROXYAPATITE THIN
FILMS
Costel COTIRLAN-SIMIONIUC, Rodica V. GHITA, Daniela PREDOI, Cristina L. POPA
S1 P33
ASSESMENT OF THE STRUCTURAL, MORPHOLOGICAL AND PHOTOCATALYTIC
PROPERTIES OF TiO2-Ag BASED POROUS NANOARHITECTURES
G. KOVÁCS, V. DANCIU, ZS. PAP, L. BAIA, V. COȘOVEANU, A. VULPOI, T. RADU, K. MAGYARI, C.
GRUIAN and M. BAIA
11
S1 P34
POROUS TiO2- SiO2 BASED MATERIALS: STRUCTURAL, MORPHOLOGICAL AND
PHOTOCATALYTIC PROPERTIES
G. KOVÁCS, V. DANCIU, ZS. PAP, M. BAIA, V. COȘOVEANU, A. VULPOI, T. RADU, K. MAGYARI, C.
GRUIAN and L. BAIA
S1 P35
ORGANIC PHOTOVOLTAIC STRUCTURES BASED ON ZINC AND MAGNESIUM
PHTHALOCYANINE THIN FILMS
M. SOCOL, C. BREAZU, O. RASOGA, A. STANCULESCU, N. PREDA, F. STANCULESCU, M.
STOICANESCU
S1 P36
DESIGNING SUPERHYDROPHOBIC POLYMER SURFACES BY CONTROLLING THEIR
MORPHOLOGIES
M. SOCOL, N. PREDA, I. ZGURA, M. ENCULESCU, A. EVANGHELIDIS, C. FLORICA, E. MATEI, I.
ENCULESCU
S1 P37
TUNABLE SURFACE WETTABILITY OF ZnO NANOSTRUCTURED FILMS PREPARED BY WET
CHEMICAL ROUTE
I. ZGURA, N. PREDA, M. SOCOL, M. ENCULESCU, A. EVANGHELIDIS, C. FLORICA, E. MATEI, I.
ENCULESCU
S1 P38
MAGNETIC STRUCTURE OF Fe/Cu(001) THIN FILMS
D. BENEA, S. MICAN, I. STANCIU, A.F.TAKACS, V. POP
S1 P39
HIGHLY TEXTURED IRIDIUM THIN FILMS GROWN ON MgO AND Si SUBSTRATES
Lucian TRUPINA, Liviu NEDELCU, Constantin Catalin NEGRILA, Marius CIOANGHER
S1 P40
DEPOSITION OF TITANIUM DIOXIDE LAYERS UPON TEXTILE MATERIALS: CHECKING THE
ADHERENCE BY ULTRA-SONICATION
Irina ZGURA, Stefan FRUNZA, Ligia FRUNZA, Monica ENCULESCU, Camelia FLORICA, Florin
COTOROBAI
S1 P41
STRUCTURAL AND MAGNETIC PROPERTIES OF Nd2Fe14B/α-Fe NANOCOMPOSITES OBTAINED
BY MECHANICAL MILLING AND SHORT TIME ANNEALING
S. MICAN, R. HIRIAN, O. ISNARD, I. CHICINAŞ and V. POP
S1 P42
STRUCTURAL AND MAGNETIC PROPERTIES OF THE Mn50Al46Ni4 ALLOY
R. C. GAVREA, S. MICAN, B. V. NEAMŢU, M. COLDEA and V. POP
S1 P43
OPTICAL PROPERTIES AND SELF-ASSEMBLING CAPACITY OF METAL-CONTAINING
SILOXANE POLYAZOMETHINES
Mirela ZALTARIOV, Maria CAZACU, Carmen RACLES, Angelica VLAD, Mihaela AVADANEI, Gabriela
HITRUC, Luiza Gradinaru, George STIUBIANU, Anton AIRINEI
S1 P44
PHOTOPHYSICAL PROPERTIES OF SOME ANTHRAQUINONE DERIVATIVES
Ionut Radu TIGOIANU, Anton AIRINEI, Mirela ZALTARIOV, Mihaela HOMOCIANU, Petronela
DORNEANU, Nicusor FIFERE, Maria CAZACU
12
S1 P45
DIELECTRIC PROPERTIES OF Ba2/3Sr1/3TiO3 FERROELECTRIC CERAMICS
L. NEDELCU, L. TRUPINA, C. P. GANEA, C. D. GEAMBASU, M. CIOANGHER, M. G. BANCIU
S1 P46
BROADBAND DIELECTRIC SPECTROSCOPY OF Mg4Nb2O9 CERAMICS
L. NEDELCU, M. G. BANCIU, C. P. GANEA, G. V. ALDICA
S1 P47
WETTABILITY PROPERTIES OF TITANIA THIN FILMS
Catalin ADOMNITEI*, GHIORGHITA Liliana and Diana MARDARE
S1 P48
STRUCTURE OPTIMIZATION AND CHARACTERIZATION OF THIN FILMS CIGS SOLAR
CELLS
P. PREPELITA
S1 P49
MAGNETIC PROPERTIES OF Tb8-XYXCo16 COMPOUNDS
A.BEZERGHEANU, C.RUSU, D. BENEA, I.GR.DEAC, R.TETEAN
S1 P50
TEMPERATURE DEPENDENCE OF THE OPTICAL PROPERTIES OF Bi2O3. A THEORETICAL
APPROACH BASING ON NEURAL NETWORK
Gabriel MURARIU, Simona CONDURACHE-BOTA, and Nicolae TIGAU
S1 P51
THE TEMPERATURE-INDUCED TRANSITION IN SPIN-CROSSOVER ISING-LIKE MODEL WITH
FLUCTUATING EXTERNAL FIELD
A. MAKSYMOV, IU. GUDYMA, C. ENACHESCU
S1 P52
THE ISING-LIKE THERMODYNAMIC MODEL OF SPIN-CROSSOVER COMPOUNDS
Iu. GUDYMA, V. IVASHKO, A. MAKSYMOV
S1 P53
OPTICAL PROPERTIES OF WIDE-BANDGAP SEMICONDUCTING OXIDES FOR DYESENSITIZED SOLAR CELLS USE
Florin MOSCALU, Gabriel PRODAN and Anca DUMBRAVA
S1 P54
POLYMER NANOSTRUCTURES AS REINFORCING AGENTS FOR ZINC OXIDE –EUGENOL
(ZOE) MATERIALS
G. CALIN, L. DARTU, L. OLARU, F. IACOMI, V. BURLUI, N. OLARU
S1 P55
SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF AAO/METALLIC NANOCOMPOSITE
G. CALIN, L. DARTU, V. BURLUI, E. VASILE, R. TRUSCA, F. IACOMI
S1 P56
PANCHROMATIC HARVESTING TECHNIQUES APPLIED FOR NATURAL DYES IN DYESENSITIZED SOLAR CELLS
Alexandru ION, Jeanina LUNGU and Anca DUMBRAVA
S1 P57
SOME OPTICAL PROPERTIES OF YbF3 DOPED BaF2 AND CaF2 CRYSTALS
Madalin BUNOIU, Marius STEF, Gabriel BUSE and Irina NICOARA
13
S1 P58
APPROACH BASING ON THE KRAMERS-KRONIG TRANSFORMATION FOR POLYNOMIAL
DIFFERENT TERMS MODELS
S1 P59
ON THE PHYSICAL PROPERTIES OF DIFFERENT OXIDES THIN FILMS OBTAINED BY
THERMAL OXIDATION
Sorina IFTIMIE, A. RADU, R. MALLET, L. ION, Mihaela GIRTAN, S. ANTOHE
S1 P60
THE SPECTRAL RESPONSE OF CdS/CdTe PHOTOVOLTAIC CELLS WITH DIFFERENT TCO’s
A. RADU, Sorina IFTIMIE, L. ION, Raluca CONSTANTINEANU, Veta GHENESCU, M. GHENESCU, S.
ANTOHE
S1 P61
DEVELOPING AND TESTING A THIN FILM SAMPLE HOLDER FOR ION BEAM ANALYSIS
Victor RUNCEANU, Adrian ROTARU
S1 P62
MANUFACTURING A SYSTEM FOR PIXE AND PIGE ANALYSIS ON THIN FILMS USING 3D
PRINTING AND COMPUTER AIDED DESIGN
Adrian ROTARU, Victor RUNCEANU
Section 2: Laser, Plasma and Radiation Physics and Applications
S2 L01
COLD AND HOT PROBE DIAGNOSTICS
Roman SCHRITTWIESER, Codrina IONITA, Stefan COSTEA, Franz MEHLMANN, Johannes GRÜNWALD,
Bernd S. SCHNEIDER
S2 L02
APPLICATION OF THE BALL-PEN PROBE IN SLIGHTLY MAGNETIZED LOW-TEMPERATURE
DISCHARGE PLASMA
M. ZANÁŠKA, M. PETERKA, J. ADÁMEK,P. KUDRNA, M. TICHÝ
S2 L03
PERIODIC STRUCTURES FORMATION ON BERYLLIUM, CARBON, TUNGSTEN FILMS MIXED
FILMS BY TW LASER IRRADIATION
C. P. LUNGU, C. M. TICOS, C. POROSNICU, I. JEPU, M. LUNGU, P.DINCA, O. POMPILIAN, D.
URSESCU, R. BANICI, G. COJOCARU, R. UNGUREANU, C. LUCULESCU, A. MARCU, R. VLADOIU, A.
MARIN, I. FERARU, C. GRIGORESCU
S2 L04
BIOACTIVE COATINGS FOR DENTAL AND ORTHOPAEDIC IMPLANTS
BIOFUNCTIONALIZATION
A.VLADESCU, C. VITELARU, M.DINU, M. BRAIC, I.PANA, A.KISS, I.TITORENCU, V. BRAIC
S2 L05
COMPLEX STUDY OF BINARY NANOCOMPOSITES DEPOSITED BY THERMIONIC VACUUM
ARC (TVA) TECHNOLOGY
Rodica VLADOIU, Aurelia MANDES, Virginia DINCA
S2 L06
RADIATIVE PROCESSES IN BULK AND TWO-DIMENSIONAL LAYERED CRYSTALS OF
MOLYBDENUM AND TUNGSTEN DICALCOGENIDES
Leonid KULYUK
14
S2 L07
WAVEGUIDES FABRICATED IN ND:YAG BY DIRECT FS-LASER WRITING - REALIZATION
AND LASER EMISSION UNDER DIODE-LASER PUMPING
Nicolaie Pavel, Gabriela SALAMU, Flavius VOICU, Traian DASCALU, Florin JIPA and Marian
ZAMFIRESCU
S2 L08
OPTIMISATION OF MECHANICAL PROPERTIES OF nc-TiC/a-C:H COATINGS
Vilma BURSIKOVA, Pavel SOUCEK , Petr VASINA, Ondrej CAHA, Jiri BURSIK, Vratislav PERINA
S2 L09
OPTICAL AND ELECTRICAL INVESTIGATIONS ON TRANSIENT PLASMAS
GENERATED BY LASER ABLATION IN VARIOUS TEMPORAL REGIMES
S. GURLUI, P. NICA, M. AGOP, M. OSIAC, C. FOCSA
S2 L010
ULTRAFAST LASER NANOSTRUCTURING ON LARGE SURFACES
Marian ZAMFIRESCU, Catalina ALBU, Gabriel COJOCARU, Simion. SANDEL, Catalin LUCULESCU
S2 L011
HIGH POWER LASER SYSTEM IN ROMANIA AND LASER DEVELOPMENTS ROADMAP FOR
ELI-NP
Ioan DANCUS, Daniel URSESCU, Liviu NEAGU, Mihail CERNAIANU, Theodor ASAVEI, Razvan DABU,
Ion MORJAN, Sydney GALES, N.V. ZAMFIR
S2 OP1
PLASMA BASED PROCESSES FOR SYNTHESIS OF METAL-POLYMER NANOCOMPOSITES
Veronica SATULU, Bogdana MITU, Simona SOMACESCU, Ionela SARBU, Diana PELINESCU, Gheorghe
DINESCU
S2 OP2
LUMINESCENCE PROPERTIES IN LANGATATE CERAMICS DOPED WITH Tm3+ AND Yb3+
Cristina MATEI, Serban GEORGESCU, Ana-Maria VOICULESCU, Angela STEFAN, Octavian TOMA
S2 OP3
MULTIPLE THz PULSES GENERATED BY OPTICAL FILAMENTATION
T. DASCALU1, O. GRIGORE1,2, M. DINCA2, N. PAVEL1, G. COJOCARU1,2, R. UNGUREANU1,2, R.
BANICI1
S2 OP4
LASER EMISSION AT 1.06 μm IN Nd: GdLuCOB AND Nd:GdCOB CRYSTALS
Catalina BRANDUS, Lucian GHEORGHE, Flavius VOICU, and Traian DASCALU
S2 P01
SYNTHESIS AND CHARACTERIZATION OF MAGNESIUM EMBEDDED IN CARBON MATRIX
BY USING THERMIONIC VACUUM ARC (TVA) TECHNOLOGY
Aurelia MANDES, Rodica VLADOIU, Virginia DINCA
S2 P02
BIOMEDICAL APPLICATIONS OF POLYMERS TREATED BY DCSDBD
Virginia DINCA, Rodica VLADOIU, Aurelia MANDES
S2 P03
ELECTRON BEAM FLUE GAS TREATMENT IN THE PRESENCE OF FINE WATER DROPLETS
Daniel IGHIGEANU, Ioan CALINESCU, Elena MANAILA, Gabriela CRACIUN
S2 P04
SYNTHESIS OF A NOVEL POLYELECTROLYTE BY COPOLYMERIZATION OF ACRYLAMIDE
AND ACRYLIC ACID BY ELECTRON BEAM IRRADIATION
Gabriela CRACIUN, Daniel IGHIGEANU, Elena MANAILA
15
S2 P05
INFLUENCE OF ABSORBED DOZE ON CROSS-LINK DENSITY OF EPDM /TMPT RUBBER
VULCANIZED BY IRRADIATION
Elena MANAILA, Maria Daniela STELESCU, Gabriela CRACIUN, Daniel IGHIGEANU
S2 P06
INFLUENCE OF TRIALLYLCYANURATE ON CROSS-LINK DENSITY OF ETHYLENE-VINYLACETATE COPOLYMER VULCANIZED BY ELECTRON BEAM PROCESSING
Elena MANAILA, Maria Daniela STELESCU, Gabriela CRACIUN, Daniel IGHIGEANU
S2 P07
NON-LINEAR COOPERATIVE DECAY PROCESS OF THREE-LEVEL SYSTEMS STIMULATED
BY THERMAL FIELD AND GENERATION OF ENTANGLED PHOTON PAIRS
Nicolae A. ENAKI, Tudor ROSCA
S2 P08
PRELIMINARY SYNTHESIS FOR TRANSPARENT 1at.% Nd-YAG CERAMICS
Catalina-Andreea VASILESCU, Traian DASCALU, George STANCIU, Ruxandra BARJEGA, Catalin
LUCULESCU, Nicolaie PAVEL
S2 P09
QUASI-PHASE-MATCHING IN HIGH ORDER HARMONIC GENERATION IN DUAL GAS
MULTIJETS
Valer TOSA and Katalin KOVACS
S2 P10
SINGLE ATTOSECOND PULSE GENERATION FROM COMBINED 50 FS LONG NIR AND MIR
LASER PULSES – CASE STUDY
K. KOVÁCS, E. BALOGH, B. MAJOR, P. WEBER, B. SCHÜTTE, A. ROUZEE, V. TOŞA, K. VARJÚ, M.J.J.
VRAKKING
S2 P11
THE INFLUENCE OF THE RASHBA SPIN-ORBIT COUPLING ON TWO-DIMENSIONAL
MAGNETOEXCITON-POLARITONS IN MICROCAVITY
S.A. MOSKALENKO, M.A. LIBERMAN, I.V. PODLESNY, E.V. DUMANOV, B.V. NOVIKOV
S2 P12
IMPACT PARAMETERS OF THE TAC PF TRACKER SYSTEM
F. B. PİLİÇER, İ. TAPAN
S2 P13
DIFFUSIVE REFLECTANCE SPECTROSCOPY (DRS) ANALYSIS IN PRACTICAL SCIENTIFIC
RESTORATION
Andrei HRIB, Carmen MITA, Dana Ortansa DOROHOI
S2 P14
DEPOSITION OF POLYMERIC COATINGS BASED ON PCL/PLGA BLENDS: A COMPARATIVE
STUDY
G. POPESCU-PELIN, E. AXENTE, F. SIMA, I. IORDACHE, C. NITA, A. VISAN, I. ZGURA, O.L.
RASOAGA, C.S. BREAZU, A. STANCULESCU, G. SOCOL, I.N. MIHAILESCU
S2 P15
PHOTON DETECTION EFFICIENCY SIMULATION OF SILICON PHOTOMULTUPLIER
Esra YILDIRIM, Fatma KOCAK, Cuneyt CELIKTAS, Ercan PILICER
16
S2 P16
VARIABLE GEOMETRY DIRECT CURRENT REACTOR USED FOR PLASMA
POLYMERIZATION
V. BARNA, V. COVLEA, B. BUTOI, CRISTINA BEREZOVSKI, D. STAICU, R. BEREZOVSKI, A. M.
MARIN
S2 P17
MULTI-COMPONENT CARBIDE PROTECTIVE COATINGS FOR TRIBOLOGICAL
APPLICATION
Alina VLADESCU, Mihai BALACEANU, Viorel BRAIC, Anca PARAU, Iulian PANA, Mariana BRAIC
S2 P18
SOLID SOLUTION OR AMORPHOUS PHASE FORMATION IN TiZr-BASED TERNARY TO
QUINTERNARY MULTI-COMPONENT FILMS
Alina VLADESCU, Nicolae Catalin ZOITA, Mihai BALACEANU, Viorel BRAIC, Mariana BRAIC
S2 P19
EMISSIVE PROBE FOR HOT PLASMAS
Bernd S. SCHNEIDER, Roman SCHRITTWIESER, Codrina IONITA, Stefan COSTEA, Franz MEHLMANN,
Johannes GRÜNWALD
S2 P20
SYNTHESIS AND CHARACTERIZATION OF La3Ga5.5Ta0.5O14 DOPED WITH HOLMIUM AND
YTTERBIUM
Ana-Maria VOICULESCU, Serban GEORGESCU, Cristina MATEI, Angela STEFAN, Octavian TOMA
Section 3: Nuclear and sub-Nuclear Physics and Applications
S3 L01
THE MANY FACETS OF THE (NON-RELATIVISTIC) NUCLEAR EQUATION OF STATE
GIANLUCA GIULIANI, H. ZHENG, A. BONASERA
S3 L02
ASYMMETRY ENERGY OF NUCLEAR MATTER: TEMPERATURE AND DENSITY
DEPENDENCE, AND VALIDITY OF SEMI-EMPIRICAL FORMULA
G. H. BORDBAR, R. FERIDOONNEZHAD, M. TAGHIZADE
S3 L03
ISOSPIN AND MASS DEPENDENCE OF DIPOLE RESPONSE IN NEUTRON-RICH NUCLEI
V. BARAN, M. COLONNA, M. DI TORO, A. CROITORU
S3 L04
ELI-NP: NEW OPPORTUNITIES FOR NUCLEAR ASTROPHYSICS
O. TESILEANU, N.V. ZAMFIR
S3 OP1
SYSTEMATICS OF THE α-DECAY FINE STRUCTURE IN EVEN-EVEN NUCLEI
D. S. DELION, A. DUMITRESCU
S3 OP2
ENERGY DEPENDENCE OF NECK FRAGMENTATION REACTION MECHANISM
M.MARCIU , V.BARAN
S3 OP3
ISOVECTOR PROTON-NEUTRON PAIRING AND WIGNER ENERGY IN HARTREE-FOCK
MEAN FIELD CALCULATIONS
D. NEGREA and N. SANDULESCU
17
S3 OP4
DISTRIBUTION OF Ca AND K RADIOACTIVE ISOTOPES IN DOBROGEA COUNTY SOIL
Daniel ENACHE, Marius BELC, I.M.OANCEA-STANESCU
S3 P01
HIGH ENERGY (MeV) ION BEAM IMPLANTATION IN INT-WS2
Mihai STRATICIUC, Alla ZAK, Doru Gheorghe PACESILA, Victor Alexandru RUNCEANU, Adrian Ionut
ROTARU, Ion BURDUCEA, Dan Gabriel GHITA, Petru Mihai Racolta
S3 P02
OPTIMIZATION OF THE GEOMETRICAL DETECTION EFFICIENCY OF THE CBM-TRD
STATIONS
L.RADULESCU, M.PETRIS, M.PETROVICI, V.SIMION
S3 P03
THICKNESS EVALUATION OF DOPED BIFEO3 THIN FILMS USING DIFFERENT TECHNIQUES
Ion BURDUCEA, Mihai Straticiuc, Dan Gabriel GHITA, Petru Mihai RACOLTA, Ecaterina Tenea, Mariuca
GARTNER, Victor FRUTH
S3 P04
THE 1MV COCKCROFT-WALTON TANDETRON ACCELERATOR DEDICATED TO
ACCELERATOR MASS SPECTROMETRY (AMS) - 14C DATING
Oana GAZA, Corina Anca SIMION, Tiberiu Bogdan SAVA, Dan Gabriel GHITA, Doru Gheorghe PACESILA,
Ionut-Catalin CALINESCU, Alexandru Marian VASILIU, Horia IOVU
S3 P05
CHALENGES OF GAMMA-RAY ASSAY DURING DECOMMISISONING
Daniela GURAU
S3 P06
GEANT4 SIMULATION OF A PROTOTYPE DETECTOR FOR MUONS RADIOGRAPHY
Valerica BABAN, Dănuţ ARGINTARU, Jipa ALEXANDRU, Eliodor CONSTANTINESCU
S3 P07
MEASUREMENT OF STRANGE PARTICLE CORRELATIONS IN PP COLLISIONS
Catalin HANGA
S3 P08
THE USE OF MICRO-PIXE IN TRANSYLVANIAN NATIVE GOLD CHARACTERIZATION
B. CONSTANTINESCU, DANIELA CRISTEA-STAN, D. CECCATO, L. PICHON, Q. LEMASSON, Claire
PACHECO
S3 P09
SOME APPLICATIONS OF MICRO-PIXE IN THE STUDY OF ANCIENT BRONZE, SILVER AND
OBSIDIAN ARTIFACTS
Daniela CRISTEA-STAN, B. CONSTANTINESCU, D. CECCATO
S3 P10
USE OF LITHIUM NITRATE AS A POTENTIALLY CORROSION INHIBITOR FOR RADIOACTIVE
ALUMINIUM IN CEMENTING SYSTEMS
M. NICU, L. IONASCU, C. TURCANU, F. DRAGOLICI
S3 P11
EFFECT OF HEAVY IONS TO THE SILICON DETECTORS
Adnan KILIÇ
S3 P12
ENERGY DEPOSITION STUDIES FOR CRYSTALS USED IN MEDICAL APPLICATIONS
Nazli ERDINIZ1, Adnan KILIC1, Fatma Belgin PILICER1, Ercan PILICER1
18
S3 P13
NEUTRON DEGRADATION OF SEVERAL POLYMERS SUBJECTED TO IBR-2 RADIATION AT
DUBNA
Eduard Marius LUNGULESCU, Radu SETNESCU, Tanța SETNESCU, Mădălina MARINESCU, Otilia
CULICOV, Sergey KULIKOV
S3 P14
RIVET PLUG-IN FOR
PRODUCTION CROSS-SECTION MEASUREMENT IN pp
COLLISIONS AT s = 7 TeV
DUMITRIU Ana Elena, A. T. GRECU
S3 P15
ENHANCING SAFETY AND RADIATION PROTECTION IN TRANSPORT OF RADIOACTIVE
MATERIAL IN ROMANIA
Gheorghe VIERU
S3 P16
THE NEW SECONDARY EXTENSION PROTON BEAM LINE AND THE DESIGN OF THE LOCAL
SHIELDING FOR TR-19 CYCLOTRON IN IFIN-HH
L. S. CRACIUN, R. G. RATA, A. T. SERBAN, C. IONESCU, D. NICULAE
S3 P17
DETERMINATION OF THEORETICAL GAMMA-RAY ATTENUATION COEFFICIENTS OF
DIFFERENT ABSORBER MATERIALS BY USING CdTe DETECTOR
E. E. ERMIS, C.CELIKTAS and E. PILICER
S3 P18
BORON EQUIVALENT DETERMINATION IN NUCLEAR GRADE GRAPHITE
Anişoara SCARLAT, Carmen ŢUCĂ, Ana PANTELICĂ, Mitică DRĂGUŞIN, Ioan IORGA, Adrian ZORLIU
S3 P19
DETERMINATION OF TRACE ELEMENTS IN GRAPHITE BY INSTRUMENTAL NEUTRON
ACTIVATION ANALYSIS
Ana PANTELICĂ, Anişoara SCARLAT, Mitică DRĂGUŞIN
S3 P20
PIXE AND PIGE ANALYSIS OF NUCLEAR GRAPHITE
Ana PANTELICĂ, Dan Gabriel GHITA, Doru PACESILA, Paul IONESCU, Anişoara SCARLAT, Mitică
DRĂGUŞIN
S3 P21
A RETROSPECTIVE STUDY OF UTERIN AREA HIGH DOSE RATE BRACHYTHERAPY
PLANNED USING CATHETER RECONSTRUCTION
Lucia Elena ENCIU
S3 P22
ATOMIC METHODS APPLIED IN THE MATERIAL CHARACTERIZATION
Madalina IVANESCU, Marius BELC, Ion V. POPESCU
19
Section 4: Cross-disciplinary Applications of Physics
S4 L01
CONTROLLING BEC PROPERTIES VIA DISORDER AND DRIVING
Antun BALAŽ
S4 L02
A NOVEL SCALING FOR HUMAN TRAVEL
I. PAPP, L. VARGA,G. TOTH, A. KOVÁCS, Z. KOVÁCS-KRAUSZ and Z.NÉDA
S4 L03
DENSITY WAVES IN DIPOLAR BOSE-EINSTEIN CONDENSATES
Alexandru I. NICOLIN
S4 L04
COHERENCE-BASED METHOD TO DETECT TIME SHIFTS BELOW THE SAMPLING
THRESHOLD OF TIME SERIES
E.I. SCARLAT
S4 OP1
MONTE CARLO SIMULATIONS FOR TRANSPORT MODELING USING FRACTIONAL
EXCLUSION STATISTICS
G. A. NEMNES and D. V. ANGHEL
S4 OP2
OPTICAL PROCEDURE FOR ESTIMATING YEAST CONCENTRATION IN AQUEOUS
SUSPENSION BY FAR FIELD SPECKLE SIZE MEASUREMENT
Dan CHICEA
S4 P01
SYNTHETIC ANABOLIC STEROIDS BINDING TO THE HUMAN ANDROGEN RECEPTOR
Alecu Aurel CIORSAC, Iuliana POPESCU, Adriana ISVORAN
S4 P02
IMPROVED DIELECTRIC RESONATOR ANTENNAS WITH HALF SPLIT BNT RESONATORS
M. G. BANCIU , L. NEDELCU, D. GEAMBAŞU
S4 P03
COMPLEX MONITORING AND ALERT SYSTEM FOR SEISMOTECTONIC PHENOMENA
Victorin-Emilian TOADER, Iren-Adelina MOLDOVAN, IONESCU Constantin
S4 P04
HYSTERESIS AND BISTABILITY IN THE I-V CHARACTERISTICS OF p-n JUNCTIONS
A. KLYUKANOV, R. SCURTU, I. INCULEŢ, P. GAŞIN
S4 P05
AFM STUDY OF THE MORPHOLOGICAL MODIFICATIONS INDUCED BY DIFFERENT
DECONTAMINATION TREATMENTS ON ESCHERICHIA COLI
ZORILA Florina Lucica, IONESCU Cristina, CRACIUN Liviu Stefan, ZORILA Bogdan
S4 P06
INFLUENCE OF MENTAL TIREDNESS IN FIXATIONAL EYE MOVEMENTS DYNAMICS
Corina ASTEFANOAEI, Dorina CREANGA, Leandro L. Di STASI, Michael B. MCCAMY, Susana
MARTINEZ-CONDE, Tudor LUCHIAN
S4 P07
CHARACTERIZATION OF HIP IMPLANTS USING WDXRF SPECTROMETRY
Simona MIHAI , Iulian BANCUTA, Roxana BANCUTA, Viviana FILIP, Gheorghe. V. CIMPOCA, Ion V.
POPESCU, Gheorghe VLAICU
20
S4 P08
THE ANTHOCYANINS STABILITY TO LIGHT AND pH FOR ITS USE IN DSSC
Andrei CHILIAN, Oana-Roxana BANCUTA, Iulian BANCUTA, Rodica-Mariana ION, Radu SETNESCU,
Anca-Irina GHEBOIANU, Tanta SETNESCU, Cristiana RADULESCU, Ion V. POPESCU, Gabriel DIMA
S4 P09
ENVIRONMENTAL ANALYSIS BY X-RAY FLUORESCENCE. DETERMINATION OF
POLLUTANTS FROM STEELWORKS DUST BY WDXRF TECHNIQUE
Gheorghe VLAICU, Iulian BANCUTA, Florin PARSAN, Nicolae PAVEL, Oana Roxana BANCUTA, Claudia
STIHI,Gheorghe Valerica CIMPOCA,Ion V. POPESCU
S4 P10
THERMAL CHARACTERIZATION OF THE RESVERATROL
Oana Roxana BANCUTA, Iulian BANCUTA, Andrei CHILIAN, Radu SETNESCU Tanta SETNESCU, Rodica
ION, Gheorghe Valerica CIMPOCA, Ion V. POPESCU, Anca Irina GHEBOIANU , Gheorghe VLAICU
S4 P11
ANALYTICAL DESCRIPTION OF THE NONLINEAR DYNAMICS OF BOSE-EINSTEIN
CONDENSATES BY MEANS OF GENETIC ALGORITHMS
Mihaela Carina RAPORTARU, Jane JOVANOVSKI, Boro JAKIMOVSKI, Dragan JAKIMOVSKI, Anastas
MISHEV
S4 P12
X-RAY STRUCTURE ELUCIDATION OF New Pyrrolo DERIVATIVES
Costel MOLDOVEANU, Gheorghiţă ZBANCIOC, Dorina MANTU, Vasilichia ANTOCI, Ionel
MANGALAGIU
S4 P13
NEW PYRROLOQUINOXALINE COMPOUNDS: SYNTHESIS AND SPECTRAL ANALYSES
Gheorghiţă ZBANCIOC, Costel MOLDOVEANU, Ana Maria ZBANCIOC, Gabriela TATARINGA, Ionel
MANGALAGIU
S4 P14
CORRELATION BETWEEN THE SECONDARY STRUCTURE ELEMENTS IN THE SPATIAL
ARRANGEMENT OF THE EF-HAND CALCIUM BINDING PROTEINS
Dana CRACIUN, Adriana ISVORAN
S4 P15
SOME SIMPLE CONSIDERATIONS REGARDING THE PROBABILITY OF LIFE APPEARANCE
ON EARTH BY CHANCE
Dan CHICEA, Radu CHICEA, Liana Maria CHICEA
S4 P16
MICROWAVE NON-THERMAL INFLUENCE ON PHANEROCHAETE CHRYSOSPORIUM CELLS
L. OPRICA, G. VOCHITA, D. CREANGA, S. MICLAUS
S4 P17
LYAPUNOV EXPONENT IN SACCADIC EYE MOVEMENTS
ASTEFANOAEI, C., AGHEORGHIESEI, C., PRETEGIANI, E. , CREANGA, D., OPTICAN L., RUFA, A.
S4 P18
GENOTOXICITY STUDY ON UV-C RADIATION IN THE VEGETAL ORGANISMS
Alexandra-Cristina UTA, Claudia NADEJDE, Dorina CREANGA, Gabriela VOCHITA
S4 P19
MONOPOLY GAME ON NETWORKS
Szerena K. UJVARI, Melinda VARGA, Gabriel ISTRATE , Zoltan NEDA
21
S4 P20
ASSESSMENT OF PESTICIDES INTERACTIONS WITH BACILLUS PASTEURII UREASE. A
COMPUTATIONAL STUDY.
Diana Larisa VLĂDOIU, Nicoleta FILIMON, Vasile OSTAFE, Adriana ISVORAN
S4 P21
ORDER AND DISORDER IN COUPLED OSCILLATORS
L. DAVIDOVA AND Z. NÉDA
S4 P22
TEM CONTRAST IMPROVEMENT IN BUCK CELL SPERM SECTIONS
C.STEFANOV, S. ZAMFIRESCU, V.CIUPINA, I.M.OANCEA-STANESCU, A.C. ROSCA
S4 P23
CORRESPONDING MODELS FOR DANUBE RIVER STATE PARAMETERS DYNAMICS. CASE
STUDY THE GALATI AREA
Gabriel MURARIU, Paula POPA, Mihaela TIMOFTI, Marian BARBU
S4 P24
INVESTIGATION OF THE HEAVY METALS CONCENTRATION DYNAMICS IN SURFACE
WATER AND SEDIMENTS FROM AQUATIC COMPLEXES SOMOVA-PARCHES
Gabriel Murariu, Adrian BURADA, Catalina ITCESCU, Catalina TOPA, Lucian GEORGESCU
Section 5: Engineering and Industrial Physics
S5 L01
DESIGN OF NANOSCALED 1D AND 2D MATERIALS BASED ON TETRAOXA[8]CIRCULENE
MINAEV B. F., KARAUSH N. N., BARYSHNIKOV G. V., MINAEVA V. A.
S5 L02
DEVELOPMENT OF HIGH SPEED AND HIGHLY SENSITIVE TERAHERTZ TIME-DOMAIN
SPECTROMETER
T. FURUYA , G. NIEHUES , S. TSUZUKI , S. OZAWA, S. AZUMA, S. FUNKNER , A. IWAMAE, K.
YAMAMOTO, S. NISHIZAWA and M. TANI
S5 L03
PAPER AND PLASTIC-BASED WASTE NEUTRALIZATION USING MICROWAVE AND
ELECTRIC ENERGY
Sebastian POPESCU and Yasunori OHTSU
S5 L04
APPLICATIONS OF ELECTRON PARAMAGNETIC RESONANCE SPECTROSCOPY IN FOOD
SCIENCE
V.BERCU1, C.D. NEGUT , O.G.DULIU
S5 L05
WETTING LAYER CONTRIBUTION TO InAs/GaAs (001) QUANTUM DOTS NUCLEATION
Gheorghe Valerica CIMPOCA, Oana Catalina BUTE,
S5 L06
DESIGNING THE PHOSPHORS OF FUTURE DOMESTIC LIGHTING
Harry RAMANANTOANINA, Werner URLAND, Fanica CIMPOESU and Claude DAUL
S5 L07
PROPERTY ENGINEERING WITH MODELING AND COMPUTATIONAL TOOLS. CHARGE
TRANSFER AND ELECTRONIC TRANSITIONS IN COMPLEX UNITS.
Fanica CIMPOESU
22
S5 L08
NEURAL NETWORK PROBLEMS IN LOW COST EMBEDDED SYSTEM
G. PRODAN,
S5 L09
A COMPUTATIONAL STUDY OF DYE REGENERATION BY COBALT-BASED ELECTROLYTES
— APPLICATIONS TO DYE-SENSITIZED SOLAR CELLS
Corneliu I. OPREA, Anamaria TRANDAFIR, Adrian TRANDAFIR, Petre PANAIT, Fanica CIMPOESU,
Daniela STAMATE, Marilena FERBINTEANU and Mihai A. GÎRŢU
S5 L10
X-RAY FLUORESCENCE AND ATOMIC ABSORBTION SPECTROMETRY APPLIED IN THE
STUDY OF HEAVY METAL POLLUTION USING MOSS BIOMONITORING
I. V.POPESCU , C.STIHI, C.RADULESCU, A.GHEBOIANU, I.BANCUTA, I.DULAMA
E.D.CHELARESCU
S5 L11
TUNING THE SIZE, SHAPE (PARTICLES AND FILMS) AND INTERACTIONS OF NANOSTRUCTUREDMATERIALS TO CONTROL THE PHOTOCATALYSTS BAND GAP AND
PHOTOCATALYTIC EFFICIENCY
B. COJOCARU,V.I. PARVULESCU
S5 L12
DESIGNING NANO-BUILDINGS BASED ON TiO2-WO3-Au FOR PHOTOCATALYTIC
APPLICATIONS
Zs. PAP, V. DANCIU, G. KOVÁCS, and L. BAIA
S5 L13
RESEARCHES ON GALVANOMETER-BASED SCANNERS WITH APPLICATIONS IN
BIOMEDICAL IMAGING
Virgil-Florin DUMA
S5 OP01
ANALYSIS OF PHYSICOCHEMICAL CHARACTERISTICS AND ELEMENTAL CONTENT OF
ROMANIAN HONEY DETERMINED BY AAS AND EDXRF SPECTROMETRY METHODS
Elena Daniela CHELARESCU
S5 OP2
FLUE GAS FILTRATION PREDICTION IN MICROFLUIDIC DEVICES USING
DIELECTROPHORESIS
Adrian NECULAE, Madalin BUNOIU, Antoanetta LUNGU, Mihai LUNGU
S5 OP3
TIME DOMAIN AND SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY
EVALUATION OF DENTAL CERAMIC EMBEDDED DEFECTS
Cosmin SINESCU, Meda NEGRUTIU, Florin TOPALA, Adrian BRADU, Virgil-Florin DUMA, Adrian GH.
PODOLEANU
S5 P01
EVALUATION OF TRACE METAL BACKGROUND CONCENTRATION IN SOIL AND
SEDIMENTS IN LOWER PRUT WETLANDS
Oleg BOGDEVICH, Dina IZMAILOVA, Antoaneta ENE, Elena CULIGHIN
S5 P02
PREPARATION AND ANALYSIS OF FUNCTIONAL MATERIALS
M. LUNGU, C. POROSNICU, I. JEPU, P. DINCA, O. POMPILIAN, C. DOBREA, T. CRACIUNESCU, I.
TISEANU
23
S5 P03
METROLOGY AND OPTICAL PERFORMANCE OF OXIDE LAYERS PREPARED BY MODERN
TECHNIQUES
F. GAROI, V. R. MEDIANU, P. PREPELITA
S5 P04
TRACE METALS IN FISH FROM FRESHWATER ECOSYSTEMS OF LOWER PRUT NATURAL
RESERVE
Elena ZUBCOV, Natalia ZUBCOV, Antoaneta ENE, Lucia BILETCHI
S5 P05
IMPACT OF SPACE WEATHER EVENTS ON THE IONOSPHERE
H HARALAMBOUS , P VRYONIDES
S5 P06
RADIOLOGICAL CHARACTERIZATION OF THE DECOMMISSIONED UNDERGROUND
RADIOACTIVE EFFLUENTS PIPES FROM THE IFIN-HH VVR-S NUCLEAR RESEARCH
REACTOR
Ioan IORGA, Alexandru Octavian PAVELESCU, Mitica DRAGUSIN, Daniela GURAU.
S5 P07
SOIL CHEMICAL POLLUTION REFLECTED IN GROUNDWATER ELECTRICAL PROPERTIES
SERBAN Adrian, IOANE Dumitru, CHITEA Florina
S5 P08
HYSTERESIS ANALYSIS IN LITHIUM-ION BATTERIES
Flavian Mihai ZACREŢCHI, Alexandru STANCU
S5 P09
MATERIALS CHARACTERIZATION USING X-RAY TECHNIQUES
Antoaneta ENE, Marina V. FRONTASYEVA, Oleg V. IGNATENKO, Constantin GHEORGHIES
S5 P10
THERMODYNAMIC CONFIGURATIONS ASSOCIATED WITH HEAVY RAINFALL IN THE
BARLAD RIVER BASIN
Daniel CARBUNARU, Sorin BURCEA
S5 P11
DIRECT AND INDIRECT METHODS FOR ASSESING AN OIL POLLUTED SITE
SERBAN Adrian, CHITEA Florina, IOANE Dumitru
S5 P12
MONITORING OF SLUDGE FROM WASTEWATER TREATMENT PLANTS IN DAMBOVITA
COUNTY: DETERMINATION OF HEAVY METALS CONCENTRATIONS BY ANALYTICAL
METHODS
R. BANCUTA, I. BANCUTA, R. SETNESCU, A. CHILIAN, T. SETNESCU, I. V. POPESCU, A.
GHEBOIANU, O. CULICOV
S5 P13
HIGH POWER TAPPED-INDUCTOR LED ARRAY DRIVER
Marius APETREI , Adrian GEORGESCU, Grigore FETECĂU
S5 P14
THERMAL PROPERTIES OF NANOSCOPIC DETECTORS
Dragos-Victor ANGHEL
S5 P15
SOME FERROSPINEL NANOPOWDERS FOR CATALYST APPLICATIONS
E. REZLESCU, C. DOROFTEI, N. REZLESCU, P.D. POPA, M. IGNAT
24
S5 P16
EVANESCENT-WAVE CAVITY RING-DOWN SPECTROSCOPY SYSTEM FOR GASES
MONITORING
Costel COTIRLAN-SIMIONIUC, Rodica GHITA, Catalin Constantin NEGRILA, Constantin LOGOFATU
S5 P17
ESTIMATION OF THE THERMAL STRESS INDICES IN ROMANIA FROM THE LARGE-SCALE
PREDICTORS
Andreea DOBRINESCU, Aristita BUSUIOC
S5 P18
SPATIAL AND TEMPORAL CHARACTERISTICS OF SEASONAL WIND SPEED VARIABILITY IN
ROMANIA
Lenuta MARIN, Marius-Victor BIRSAN, Alexandru DUMITRESCU, Aristita BUSUIOC
S5 P19
LESSONS LEARNED ON RADIOLOGICAL EQUIPMENT SELECTION AND MATCHING IN
ORDER TO COMPLY WITH SPECIFIC REQUIREMENTS
Gheorghe DOGARU, Felicia DRAGOLICI, Laurentiu DONE
S5 P20
SEISMICITY EVOLUTION IN ROMANIA IN RECENT YEARS AND FAULT PLANE SOLUTIONS
RELATED TO MAJOR SEISMIC ZONES
A CRAIU, M. CRAIU, A. MARMUREANU
S5 P21
PHYSICO - CHEMICAL CHARACTERIZATION OF SEVERAL SEWAGE SLUDGES
Tanta SETNESCU, Anca GHEBOIANU, Radu SETNESCU, Iulian BĂNCUŢĂ, Roxana BĂNCUŢĂ, Marius
BUMBAC, Otilia CULICOV, Marina FRONTASYEVA
S5 P22
CROSS CORRELATION OF VLF/LF RADIO PROPAGATION PATHS AND THE EUROPEAN
SEISMICITY
Iren-Adelina MOLDOVAN, Dragos TOMA-DANILA, Angela Petruta CONSTANTIN, Mihaela POPA,
Victorin Emilian TOADER , Anica Otilia PLACINTA, Adrian Septimiu MOLDOVAN
S5 P23
SEISMICITY OF THE EASTERN PART OF THE MOESIAN PLATFORM
Mihail DIACONESCU, Angela Petruta CONSTANTIN, Iren-Adelina MOLDOVAN, Dragos TOMA-DANILA
S5 P24
MACROSEISMIC STUDY OF MAJOR TRANSBORDER HISTORICAL EARTHQUAKE
Angela Petruta CONSTANTIN, Mihail DIACONESCU, Iren-Adelina MOLDOVAN
S5 P25
DESIGN AND ANALYSIS OF A RAYLEIGH SAW RESONATOR FOR GAS DETECTING
APPLICATIONS
Viorel IONESCU
S5 P26
THERMAL INFRARED SATELLITE REMOTE SENSING FOR BUCHAREST ENVIRONMENTAL
STUDIES
Maria ZORAN, Roxana SAVASTRU, Dan SAVASTRU
S5 P27
EARTHQUAKE PRESIGNALS ASSESSMENT IN VRANCEA GEOTECTONIC ACTIVE ZONE
THROUGH SATELLITE AND IN-SITU MONITORING DATA
25
S5 P28
SPECTRAL MIXTURE ANALYSIS POTENTIAL OF SATELLITE IMAGERY
ANALYSIS FOR BUCHAREST URBAN ENVIRONMENT ASSESSMENT
Maria ZORAN, Roxana SAVASTRU, Dan SAVASTRU, Marina TAUTAN, Sorin MICLOS, Laurentiu
BASCHIR
S5 P29
PHYSICAL CHARACTERIZATION OF BIOLOGICAL CELLS USING AN ASSISTED
MICROMECHANIC SYSTEM
Mihaita Nicolae ARDELEANU, Marius Giorgian IONITA, Valentin GURGU, Ioan Alin BUCURICA, Ioana
Daniela DULAMA, Emil LUNGU
S5 P30
HEAVY METALS DISTRIBUTION IN URBAN SOILS COLLECTED FROM TARGOVISTE CITY
Ioana Daniela DULAMA, Claudia STIHI, Cristiana RADULESCU, Ion V. POPESCU, Ioan Alin BUCURICA,
Raluca STIRBESCU, Lucica Grigora TOMA, Daniela Elena CHELARESCU
S5 P31
NEW MIXED LIGAND CO(II) COMPLEXES AS POSSIBLE ELECTROLYTES FOR DYESENSITEZED SOLAR CELLS – A COMBINED EXPERIMENTAL AND COMPUTATIONAL
APPROACH
Marilena FERBINTEANU, Daniela STAMATE, Corneliu I. OPREA, Petre PANAIT, Mihai A. GÎRŢU
S5 P32
THE INTERACTION OF TiO2 NANOPARTICLES WITH FUNCTIONAL GROUPS OF SOME
AROMATIC AZO DYES IN DYE-SENSITIZED SOLAR CELLS AND IN PHOTOCATALYTIC
PROCESSES
Petre PANAIT, Corneliu I. OPREA, Jeanina, LUNGU, Daniela STAMATE,Anca DUMBRAVA, Mihai A.
GÎRŢU
S5 P33
ADSORPTION OF COUMARIN-BASED DYES ON TiO2 NANOCLUSTERS – EFFECT ON THE
SHORT-CIRCUIT CURRENT OF DYE-SENSITIZED SOLAR CELLS
Petre PANAIT,Corneliu I. OPREA and Mihai A. GÎRŢU
S5 P34
CRUSTAL SEISMICITY ANALYSIS IN ROMANIA USING ANTELOPE AND SEISCOMP 3
M. CRAIU, A. MARMUREANU, A. CRAIU
Section 6: Topics in Physics Education Research
S6 L01
THE BENCHMARKS OF A SUCCESSFUL REFORM PROPOSAL IN EDUCATION
C.HATU
S6 L02
KNOWLEDGE’S ASSESSMENT BY ITEM RESPONSE MODELS
Cristian OPARIUC-DAN
S6 L03
CHALLENGES IN PHYSICS TEACHING AND ASSESSMENT
Roxana ZUS
S6 OP01
THE KEY EXPERIMENT USING „AT HAND” RESOURCES – AN EFFICIENT METHOD IN
PHYSICS TEACHING
Ion BĂRARU
S6 P01
26
STUDYING PHYSICS BY TECHNOLOGICAL APPLICATIONS
Mihaela GHELMEZ (DUMITRU)1, Ionut-Alexandru MOLDOVEANU2,Manuel RIBEIRO DA SILVA
S6 P02
OPPORTUNITIES FOR IMPROVEMENT THE TEACHING PROCESS -CULTIVATION STUDENTS´
CREATIVE THINKING
Irina MARIN
S6 P03
BLENDED LEARNING MODELS IN ROMANIAN SCIENCE EDUCATION
Dana CRACIUN1, Madalin BUNOIU
S6 P04
LEARNING PHYSICS THROUGH ACTING GAMES
D. RĂSLEANU, A. DANCU, D. PETRE
28
PLENARY SESSION
14th International Balkan Workshop on Applied
Physics
ABSTRACTS
S0 – PLENARY SESSION
PLENARY SESSION
29
S0 01
Ce:(Y1-xLux)3Al5O12 SINGLE CRYSTAL PHOSPHORS FOR HIGH-BRIGHTNESS WHITE LEDS
K. SHIMAMURA1, E.G. VÍLLORA1, S. ARJOCA1, D. INOMATA2, K. AOKI2, J. HAYASHI3
1
National Institute for Materials Science, Tsukuba 305-0044, Japan,
Koha Co., Ltd., Tokyo 176-0022, Japan, 3 Shinko Manufacturing Co., Ltd., Osaka 534-0016, Japan
[email protected] / http://www.nims.go.jp/group/oscg/index_e.html
2
White light-emitting diodes (WLEDs) are demanded for general lighting applications. The most economical
WLED consists of a blue-LED and the yellow-phosphor Ce3+:Y3Al5O12 (Ce:YAG). Current packaging involves
Ce:YAG phosphor in powder form mixed with resins on top of the blue InGaN LED. In applications that require
high-brightness (HB), the encapsulant is degraded by high irradiation and Ce:YAG conversion efficiency is
quenched with the high operation temperature. This leads to a decrease in LED efficiency and lifetime. For HBWLED applications instead of current powder phosphors, we propose the use of single crystal phosphor plates
(SCPPs). These overcome the mentioned problems and are therefore especially suitable for HB-WLEDs.
Ce:YAG and Ce:(Y1-xLux)3Al5O12 (Ce:(Y,Lu)AG) single crystals were grown by the Czochralski method
(Fig.1). Fig.2 shows the internal quantum efficiency (QEint) of a Ce:YAG SCPP in comparison with a
commercial powder phosphor. As can be seen, the SCPP exhibits a very high QEint (over 95%), with an
outstanding temperature stability. Blue-LEDs + Ce:YAG deliver “cold” white light. It will be shown that
“warm” white light sources, with a tunable color temperature and a very high color rendering (Ra > 95) can be
obtained by adding a red phosphor on Ce:(Y,Lu)AG SCPPs.In summary, SCPPs operate as remote phosphors;
exhibit a very high QEint, and very high radiation and temperature stability, so that they are excellent candidates
as phosphors for HB-WLEDs. The effect of Gd on YAG will also be discussed.
Fig.1: 2 inch Ce:YAG single crystal.
Fig.2: QEint vs. temperature.
30
PLENARY SESSION
S0 02
INTERFACE PHENOMENA IN ORGANIC ELECTRONICS
MATS FAHLMAN
Division of Surface Physics and Chemistry, Department of Physics, Chemistry and Biology, Linköping
University, SE-58183, Linköping, Sweden
All organic-based electronic devices are made by deposition of successive layers (metal, oxide, insulating or
semiconducting layers), and many key electronic processes (such as charge injection from metallic electrodes,
charge recombination into light or light conversion into charges, etc.) occur at interfaces. In fact, as charges are
localized on (parts of) molecules in most films, even charge transport through a film can be seen as a sequence of
charge injection events at organic-organic junctions. Organic electronic and spintronic device performance thus
is strongly linked to the energy level alignment at the various interfaces contained within, and it is of great
importance to understand and predict energy level alignment at both metal-organic and organic-organic
interfaces. Here we will give an overview on energy level alignment at interfaces and give examples of how
photoelectron spectroscopy, sometimes combined with interface modeling, can shed light on device functionality
in e.g. organic photovoltaics,1 transistors,2 thermoelectrics3 and spintronics.4
References
1. Mats Fahlman, Parisa Sehati, Wojciech Osikowicz, Slawomir Braun, Michel P. de Jong, Geert Brocks,
J. Electron Spectrosc. Relat. Phenom, 190 (2013) 33.
2. Simone Fabiano, Slawomir Braun, Mats Fahlman, Xavier Crispin and Magnus Berggren , Adv. Funct.
Mater., 2013, 10.1002/adfm.201302070
3. Olga Bubnova, Zia Ullah Khan, Abdellah Malti, Slawomir Braun, Mats Fahlman, Magnus Berggren
and Xavier Crispin, Nature Mater., 10 (2011) 429; Olga Bubnova, et al, Nature Mater., 13 (2014) 190.
4. Yiqiang Zhan, Erik Holmström, Raquel Lizárraga, Olle Eriksson, Xianjie Liu, Fenghong Li, Elin
Carlegrim, Sven Stafström and Mats Fahlman, Adv. Mater., 22 (2010) 1626.
PLENARY SESSION
31
S0 03
GIANT MICRO-PHOTONICS FOR FUTURE ENERGY
Takunori TAIRA
1
Institute for Molecular Science, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan
Progress of internal combustion engines has been paced by the melioration of ignitions for efficient and
high-power engines. Even now, the improvement of thermal efficiency in combustion engines, and the
reductions of carbon dioxides (CO2) and harmful pollutant emissions (NOx, SOx and etc.) have become more
important. IEA reported the current energy ratio of the coal, oil and gas is up to 82%. There are no changes for
25 years. Furthermore, IEA predicted their energy share in 2040 should be still 79% [1]. On the other hand,
much CO2 emission reduction has been realized with “Shale Gas Revolution” in USA [2]. These indicate that the
improvement of combustion engines promise to have a great impact on the future of the world. On the other
hand, rapid growth of solid-state laser development since the first laser action demonstration by Maiman on
1960, have created the new fields in science. With the progress of giant pulse (>10 6 W) solid-state laser, the
quantum electronics based laser ignitions for combustion engine have been discussed widely to make change the
ignition innovatively and have many advantages compared with conventional electromagnetism based electric
spark plugs. Also, a laser can ignite at the optimal spatial points apart from a “cold” cylinder wall of a
combustion chamber, and it also does not suffer from thermal quenching effect of electrodes. In addition,
because of the flexibility of light, laser ignition has great potential for simultaneous, spatial multipoint ignition
within a chamber. This shortens combustion time dramatically, and improves the power and efficiency of
engines. Further lasers can ignite leaner or highpressure mixtures that are difficult to be ignited by a
conventional electric spark plug. A laser igniter should
be expected to have a longer lifetime than a spark plug
due to the absence of electrodes [3]. Unfortunately,
laser ignitions were limited as a basic research for a
long time [4]. Recently, this situation has been
changed. Much progress in micro solid-state photonics
could provide extreme performances as a new
generation of solid-state lasers. The world first
microchip laser ignited real gasoline engine vehicle has
been demonstrated by a new generation of
quantum-electronics as “Giant Micro-photonics”
Fig. 1 Energy save by Giant Micro-photonics based laser ignition.
[5]-[9].
International Energy Agency (IEA), “World Energy Outlook 2013,” ISBN 978-92-64-20130-9.
Business Topics, WEDGE, 25 (12), 35 (2013).
R. Hickling, et al., SAE Tech. Paper, 740114, 555 (1974).
D. Graham-Rowe, Nature Photonics, 2 (9), 515 (2008).
M.Tsunekane, et. al., IEEE J.Quantum Elecron., 46 (2), 277 (2010).
OSA News <http://www.osa.org/en-us/about_osa/newsroom/newsreleases/2011/lasersparksrevolution/>
BBC News <http://www.bbc.co.uk/news/science-environment-13160950>
T. Taira, "Domain-controlled laser ceramics toward giant micro-photonics [Invited], " Opt. Mater. Express,
1 (5), 1040-1050 (2011).
[9] T. Taira, et. al., LIC’13, OPIC ’13, Yokohama, Japan, April 23-25, LIC3-1 (2013).
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
32
PLENARY SESSION
S0 04
NUCLEAR PHYSICS AND APPLICATIONS AT ELI–NP
Calin Alexandru UR
National Institute for Physics and Nuclear Engineering (IFIN–HH), Bucharest, Romania
Extreme Light Infrastructure – Nuclear Physics (ELI–NP) is one of the three pillars of the pan–European ELI
initiative, aiming to use extreme electromagnetic fields for nuclear physics research. The pillar is presently under
construction and will comprise two state–of–the–art research equipment: a high power laser system and a very
brilliant gamma beam system. The high power laser system will consist of two 10 PW lasers. The gamma beam
produced via Compton backscattering of a laser beam on a relativistic electron beam will be characterized by a
narrow bandwidth (< 0.5%) and tunable energy of up to 20 MeV. The research program of the facility will cover
a broad range of key topics in frontier fundamental physics, new nuclear physics as well as the development of
innovative applications.
The status of the project, the overall performance characteristics and the main fundamental physics and applied
research topics will be reviewed.
S0 05
VORTEX CONFIGURATIONS IN BOSE-EINSTEIN CONDENSATES: FROM THE QUANTUM
SPIROGRAPH TO VORTEX LATTICES
Ricardo CARRETERO-GONZALEZ
Nonlinear Dynamical Systems Group, Department of Mathematics and Statistics, San Diego State University,
San Diego CA, 92182-7720, USA E-mail: [email protected]
Motivated by recent experiments studying the dynamics of configurations bearing a small number of vortices in
atomic Bose-Einstein condensates (BECs), we illustrate that such systems can be accurately described by
reduced models of coupled ordinary differential equations (ODEs). We study in detail the dynamics and
symmetry-breaking bifurcations of vortex pair configurations yielding an excellent agreement with experimental
observations. Cases with higher number of vortices arranged in a polygon are also studied and found to be stable
up to a critical number of vortices. Finally, for larger collections of vortices, we introduce a coarse-graining
continuum approach enabling the accurate identification of the radial distribution of co-rotating stationary vortex
lattices.
PLENARY SESSION
33
S0 06
THE CENTRE FOR ADVANCED LASER TEHNOLOGIES
(CETAL)
Constantin GRIGORIU, Constantin FENIC, Dan SPOREA, Catalin TICOS, Ion MORJAN
National Institute of Laser, Plasma and Radiation Physics,
Atomistilor 409, Măgurele, Jud. Ilfov, 077125, Romania
The CETAL facility is being developed at the National
Institute for Laser, Plasma and Radiation Physics
(NILPRP), Bucharest-Măgurele. It is a world class facility
and the first centre for research in the field of photonics in
Romania and in South-Eastern Europe.
CETAL will enable new basic/applied exploratory research
activities in physics, chemistry, biology /medicine, energy,
material science, manufacturing, etc., providing a direct
benefit to the Romanian economy and to society.
The centre consists of three major labs:
 Hyper-intense laser – mater interaction laboratory
 Laboratory for advanced technologies by laser processing
 Laboratory for photonics investigations
One of the main research fields will be in the frontier scientific domain of hyper-intense laser beam-matter
interaction at levels of the electromagnetic radiation density over 10 20 W/cm2.
The main equipment is a high power femtosecond laser system of 1 PW/25 fs, the most powerful femtosecond
laser in Europe.
Specific experiments: physics of extreme states of matter in hyper-intense optical fields, accelerated particle
beams, higher harmonic generation, X-ray beams, etc.).
This laboratory will provide a major role in training of the specialists for Extreme Light Infrastructure –Nuclear
Physics (ELI-NP) and will allow the study of technological issues which must be overcame for ELI-NP laser
systems.
1 PW /25 fs laser system
A suite of equipment (pulsed and CW lasers) will be
dedicated for diverse exploratory research activities with
applications in material processing or material synthesis, from macro to micro and down to the nanoscale level
(drilling, welding, cutting, thermal treatments, cladding, pulsed laser deposition, 3D laser lithography,
photochemistry, etc.). New advanced technologies will be especially developed for Small-Medium-Enterprises
(SMEs). The synthesis of new materials (metamaterials, photonic crystals, nanomaterials, etc.) will also be
promoted.
Another area of investigations in the field of photonics will deal with the evaluation and application of optical
radiation over the entire spectral domain between 180 nm (UV) and 1 mm (THz) (measurements, testing,
metrology and education). The laboratory will facilitate studies such as: optical frequency reference based on
frequency comb laser, optical clocks, chemical identification/imaging, THz technologies, coherent and noncoherent optical spectroscopy, laser metrology, etc.
CETAL will be an opportunity for the scientific photonics community to accede to the forefront of advanced
research and to strengthen the innovative and technological capabilities of SMEs.
The implementation of CETAL will foster mutually beneficial research collaboration on a national and European
level, NILPRP joining to the European Union efforts to develop regional R&D activities.
34
Section 1 - MATERIALS PHYSICS
SECTION
S1 – Materials Physics
Semiconductors, Dielectrics and Organic Materials
Spintronics, Magnetism and Superconductivity
Crystal growth, Surfaces, Interfaces and Thin Films
Polymers and Amorphous Materials
35
INVITED LECTURES
S1 L01
ADDRESSING PROPERTIES OF MORPHOLOGICALLY COMPLEX MATERIALS AND NANOSTRUCTURES USING SYNCHROTRON BASED PHOTOELECTRON MICROSCOPY
Maya KISKINOVA
Elettra-Sincrotrone Trieste, Area Science Park, Trieste 34149, Italy
An important prerequisite for understanding dimensionality dependent phenomena in nano-structured materials
is probing their properties at their natural length scales. The complementary capabilities of synchrotron-based
photoelectron microscopes, in terms of imaging, spectroscopy, spatial and time resolution, have opened unique
opportunities to explore the properties of technologically relevant complex materials at their natural length scales
and to follow their modifications when exposed to different environment. In particular, chemical specific
imaging and micro-spectroscopy of processes occurring at surfaces and interfaces is shedding light on key
factors governing the complexity at microscopic length scales, a prerequisite for understanding dimensionality
dependent phenomena. The recent achievements in this respect will be illustrated by selected results obtained
with the synchrotron-based Scanning PhotoElectron Microscopy (SPEM) and X-ray PhotoEmission Electron
Microscopy (XPEEM), outlining the complementary capabilities of the two microscopy approaches in terms of
imaging, spectroscopy, spatial and time resolution [1, 2]. The specific topics that will be addressed and discussed
in the talk are (i) self-assembly in multi-component adlayers [3]; (ii) size and morphology effects in supported
catalyst particles [4]; (iii) oxidation–reduction and mass transport events in operating electrochemical cells [5];
and (iv) reactivity and electronic properties of individual nanostructures [7-9]. They will demonstrate the unique
opportunities provided by synchrotron-based photoelectron microscopes to explore the surface structural,
electronic and transport properties as a function of their size, morphology, gas environment and temperature.
[1] A. Barinov et al, Nucl. Instr. Meth. Phys. Res. A 601 (2009) 195.
[2] A. Locatelli et al, Chemistry A, Eur. J. 12 (2006) 8890.
[3] T.O. Mentes et al, EPL, 94 (2011) 38003.
[4] M. Dalmiglio et al, J. Phys. Chem. C 114 (2010) 16885.
[5] B. Bozzini et al, Chem. Eur. J. 18 (2012) 10196; Scientific Reports 2013, DOI: 10.1038/srep02848
[6] A. Kolmakov et al, ACS Nano 2 (2008) 1993.
[7] A. Barinov et al, Adv. Mater. 21 (2009) 1916.
[8] F. Jabeen et al, Nano Res. 3 (2010) 706.
36
S1 L02
FIRST-PRINCIPLES SIMULATIONS OF PLATINUM AND PALLADIUM CATALYSTS UNDER
OXYGEN-RICH CONDITIONS
Nicola SERIANI
The Abdus Salam ICTP, Strada Costiera 11, 34151 Trieste, Italy
The catalytic activity of nanostructured platinum-group catalysts is influenced by size and morphology of the
nanostructures. At the same time, morphology and stability of a nanostructure depend crucially on the
environmental conditions of fabrication and operation. It is therefore of fundamental interest to understand in
detail how the environment influences these properties. In this talk, I will discuss atomistic simulations based on
density functional theory aimed at investigating the formation and stability of bulk and nanostructured oxides of
platinum and palladium in an oxygen-rich environment. I will show that the thermodynamics of oxides is
different when the nanoscopic size is taken into account and that this has consequences for their functionality.
Moreover, the calculations predict that the addition of promoters like sodium to a palladium catalyst can also
lead to the formation of unconventional oxide phases such as cubic NaPd 3O4. I will thoroughly compare the
calculations with experimental results on oxidation state, morphology and functional behavior of nanostructures,
and I will discuss open questions and future developments.
[1] N. Seriani, W. Pompe, L. Colombi Ciacchi, Journal of Physical Chemistry B 110, 14860 (2006)
[2] N. Seriani, Z. Jin, W. Pompe, L. Colombi Ciacchi, Physical Review B 76, 155421 (2007)
[3] N. Seriani, F. Mittendorfer, Journal of Physics: Condensed Matter 20, 184023 (2008)
[4] A. Dianat, N. Seriani, M. Bobeth, W. Pompe, L. Colombi Ciacchi, Journal of Physical Chemistry C 112,
13623 (2008)
[5] N. Seriani, J. Harl, F. Mittendorfer, G. Kresse, Journal of Chemical Physics 131, 054701 (2009)
[6] N. Seriani, Journal of Physical Chemistry C 116, 22974 (2012)
37
S1 L03
EFFECTS OF IONIZING RADIATIONS ON THE PERFORMANCES OF CdS/CdTe SOLAR CELLS
Ştefan ANTOHE
University of Bucharest, Faculty of Physics, Department of Electricity, Solid State and Biophysics, 077125,
Magurele-Ilfov, Atomistilor 405, Romania, [email protected]
Due to their physical and chemical properties (such as suitable band gaps, large absorption coefficients and good
chemical stability) CdS and CdTe thin films are interesting materials for electronic and optoelectronic devices,
including particularly, the photovoltaic cells for both terrestrial and space applications. For this specific
application, it is of prime importance to study the influence of ionizing radiations on the structural, electrical and
optical properties of the component materials on a hand and on the photovoltaic structures based on them, on the
other hand.
In this paper, the photovoltaic cells based on CdS/CdTe thin films, produced by thermal vacuum sublimation,
were irradiated with protons and alpha particles, (both components of cosmic rays), at room temperature. The
irradiation energy for both protons and alpha particles was 3 MeV and the fluencies were 10 14 protons/cm2 and
1013 alpha particles/cm2, respectively. The prepared samples configuration was a ”superstrat” one having CdS as
”window” layer and CdTe as ”absorber” layer, respectively. The films were deposited by conventional thermal
vacuum evaporation technique. The CdS/CdTe is given a post deposition CdCl2 heat treatment which enables
grain enhancement, reduces the defect density in the films, promotes the interdiffusion of the CdTe and CdS
layers and thereby improves solar cell efficiency. The effects of irradiation were studied by investigating the
changes in the electrical and optical properties of the cells. The structures were electrical characterized before
and after protons and alpha particles irradiation by measuring the I-V characteristics both in dark and in AM 1.5
conditions and the results were compared. The parameters characterizing a photovoltaic cell, short-circuit
current, open circuit photovoltage and fill factor were calculated before and after protons and alpha particles
irradiation and the obtained values are comparable, but less for irradiated samples. Moreover, the maximum
power obtained for a photovoltaic cell half decreased after alpha particles irradiation. A discussion about the
possible origin of those defects is given. In this sense, it was found that proton irradiation in the above mentioned
conditions results mainly in the introduction of defects at the CdS/CdTe interface.
Keywords: Solar cells, Cadmium Telluride, Thin Films, Proton and Alpha Particles Irradiation
Acknowledgements: Partially this work was supported by the Project CDI-STAR ,,Stability tests on new
photovoltaic structures for space applications against the protons and alpha particles irradiation”, No. 64/2013
38
S1 L04
GRAPHENE: FACTS AND FICTIONS
Ali EFTEKHARI
National Institute of Arts & Sciences, 411 Walnut Street, Green Cove Springs, Florida 32043-3443, United
States; Email: [email protected]
Department of Materials Science & Engineering, Jimma University, P. O. Box 1282, Jimma, Ethiopia; Email:
[email protected]
Graphene is one of the most promising nanomaterials, which attracted the attention of research from quite
different disciplines in the past two decades. Since the potential features of graphene were initially predicted
theoretically rather than experimental findings, the potentials of graphene for practical applications have been
somehow exaggerated, and thus, this nanomaterial is somewhat fashionable now.
The main problem in this direction is that most the main effort is to achieve the targeted properties rather than
fundamental studies of the nanomaterial in the course of synthesis. As a result, several common techniques are
generally used for the characterization of graphene without considering their reliability for the material under
consideration.
For example, Atomic Force Microscopy (AFM) is widely used to judge about the thickness of graphene samples,
without considering the fact that a very small amount of sample is used for AFM experiments, and finding a
graphite sample with a few layers of graphene does not guarantee that this is the dominant structure in the whole
sample. As a matter of fact, it is probable to find a few layers of graphene in any graphite sample.
In general, the main focus is on selective techniques for judging a graphene sample, though it is necessary to
examine a considerable amount of the sample to judge about a dominant nanostructure across the sample.
Thermogravimetric Analysis (TGA) is a reliable technique, as the data can be statistically extended for the entire
sample. In the preparation of graphene samples with lesser layers, TGA is a guiding star, as reactivity of graphite
depends on the number of layers. In the simplest experiment, reaction of carbon nanomaterials with oxygen can
reveal how much the individual carbon atoms are chemically exposed to the reactive oxygen.
For the case of a single sheet of graphene, the burning temperature should be quite low due to the exposure of
carbon atoms to the atmosphere oxygen. For an ideally smooth sheet of graphene, the burning temperature is
higher than single walled carbon nanotubes, as the altered hybrid of carbon atoms in curved structure of carbon
nanotubes enhances the chemical reactivity. However, it should be taken into account that a huge flat sheet of
graphene is mechanically unstable. In any case, TGA can give us a reliable estimation for the size distribution of
such nanomaterials.
In this talk, it is attempted to propose a straightforward pathway for the characterization of graphene samples.
[1] A. Eftekhari, P. Jafarkhani, J. Phys. Chem. C, 2013, 117, 25845.
39
S1 L05
FUNDAMENTAL ASPECTS IN SOLUTION GROWTH OF
NONLINEAR TETRAGONAL CRYSTALS
Horia V. ALEXANDRU
University of Bucharest, Faculty of Physics, P.O. Box 74-165, Bucharest, Romania
Tetragonal crystals from the KDP (KH2PO4) family have essential technological applications, particularly in the
nuclear fusion program. In such programs are involved USA, Japan, France, etc. This technology use a number
of high power lasers (192 in the USA program and 240 in France) which shuts simultaneously in less than
nanosecond time, a minute target of hydrogen and deuterium in a gold capsule (less than 1 cm diameter). A
temperature of 100 billion Celsius degrees attained, activate the nuclear fusion and the release of a huge quantity
of energy. Besides a possible source of energy, such nuclear reactions are studied on line. Both, the third
harmonic generation and the Q-switch effect to release the laser pulses at appropriate times are realized using
KDP crystals. On this purpose and for some other nonlinear applications of the KDP crystals family, the kinetics
and peculiar aspects of such crystal growing from solution are very important. Some data we have already
presented in the Intern. Conf. on Crystal Growth - Warsaw - August 11-16, 2013 and shall be completed for this
lecture.
Kinetic and peculiar growth properties of KDP and ADP (NH 4H2PO4) tetragonal crystals shall be presented.
Fractional recrystallization procedure in many steps was used to improve the quality of the basic substance (H.V.
Alexandru 2007). Optimum stirring rates (reversible rotation) was used to ensure the kinetic regime of growth
and horizontal [001] and vertical [110] crystals dimensions were registered in-situ versus the supersaturation.
Arrhenius corrections of the growth rates were made for rates measured at several temperatures.
The influence of the very sensitive Me3+ impurities (with adsorption energy of ~18 kcal/mol) was carefully
analyzed at several levels of supersaturations , during growth periods of one month. At the limit of the “dead
growth zone”, at smaller supersaturations, the critical coverage of impurities *~10-3 is much higher than  ~10-6
at higher supersaturations (  8%) of 2D nucleation regime of growth. This figure suggests the segregation
coefficient of such impurity increases dramatically towards the lower supersaturations.
The surface diffusion mechanism of growth is adequate to apply at usual supersaturations, but other peculiar
aspects are very important. The extremely large dispersion of the growth kinetic at   1÷5 % fits a large number
of distinct BCF curves, corresponding to several growth efficiencies. The interaction of dislocations having
several Burgers vector in the dominating centers of dislocations which are responsible for the large dispersion of
the experimental data shall be discussed. Unexpected switching effect of efficiencies, found around 0.5 %
supersaturations shall be discussed in relation with literature data (Vekilov, Kuznetsov 1992 ).
40
S1 L06
RECENT DEVELOPMENT OF RARE EARTH LEAN PERMANENT MAGNETS
V. POP
Babeş-Bolyai University, Faculty of Physics, Cluj-Napoca, RO-400084 Romania
Permanent magnets are of continuous increasing importance because they become critical
components in many devices and advanced technologies. From all the magnets on the market, the rare earth (RE)
based permanent magnets present the better magnetic properties (high remanence and the higher specific
energy). The major weakness of RE based magnets consists in the global distribution of rare earths, the major
resources being located in China, which imposed a high price and high risk of these materials. This paper aims to
present the development of new magnetic materials for the next generation of RE lean (or free) permanent
magnets. Many research directions have been conducted in the last years in order to reduce the rare-earth content
of magnets and to increase the magnet’s energy product. Certainly, it is not a trivial task to reduce the amount of
RE without diminishing the magnetic performances and the way we propose in this paper is to compensate the
anisotropy energy given by the RE by additional, eventual extrinsic, anisotropy sources and to take advantages
of the magnetic nanocomposites.
Nanocomposite spring-magnets, consisting of a fine mixture of hard (high coercivity) and soft (high
magnetization) magnetic phases, have attracted attention for permanent magnet fabrication [1]. Additionally to
the predicted high energy product of 1090 kJ/m3 [2], the presence of Fe or Fe based phases in spring magnets is
promising for better thermal stabilities, higher corrosion resistance and lower prices. The exchange-spring
behaviour can be understood on the basis of the intrinsic parameters of the hard and soft magnetic phases, which
are coupled by exchange interactions.
Another promising group of materials are the tetragonal distorted Fe based alloys with predicted high
saturation magnetization and uniaxial magnetic anisotropy for specific values of the lattice distortion c/a and the
alloy composition [3]. For the new Fe16N2 phase [4], 3.0μB/Fe magnetic moment was reported. By band structure
calculations in iron intermetallic compounds with rare earth or thorium we found Fe magnetic moment of 3.4
μB/Fe [5].
New promising magnetic phases, without rare earths, with high coercivity and interesting magnetic
properties could be the Mn-Bi or Mn-Al intermetallic phases [6, 7]. Due to its magnetization, 600 kA/m at 300
K, and to important axial anisotropy at high temperature (~ 3·10 6 J/m3 at 500 K), the MnBi compound has been
considered to be of interest for the application as a permanent magnet and for magneto-optic devices [8, 9].
1.
2.
3.
4.
5.
6.
7.
8.
9.
R. Coehoorn, D.B. de Mooij, C. De Waard, J. Magn. Magn. Mater. 80, 101, (1989)
R. Skomski et al IEEE Trans. Magn. 49 (2013) 3215
A. S. Mikhaylushkin et al, Phys. Rev. B 79 (2009)132106
Eiji Kita et al., J. Magn. Magn. Matter. 310 (2007) 2411
D. Benea, O. Isnard, J. Minar, H. Ebert, and V. Pop, J. Appl. Phys. 109 (2011)
J. H. Park et al., kjhgfcv J. Apll. Phys. 107 (2010) 09A731
Yongsheng Liu et al. Phys. Review B 72, 214410 (2005)
N.V. RamaRao, A.M. Gabay, X. Hu, G.C. Hadjipanayis, J. Alloys Comp. 586 (2014) 349
S. Gutoiu, E. Dorolti, O. Isnard, V. Pop, I. Chicinaş, Studia Univ. “Babes-Bolyai”, Physica, 54 (2009) 33
Acknowledgment: The author would like to acknowledge the support from the Romanian UEFISCDI Project
No. PN-II-ID-PCE-2012-4-0470.
41
S1 L07
CHEMISTRY AND PHOTOCHEMISTRY AT FERROELECTRIC SURFACES
Cristian-Mihail TEODORESCU
National Institute of Materials Physics, Atomistilor 105b, 077125 Magurele-Ilfov, Romania
Ferroelectric single crystal surfaces are a hot topic nowadays, justified by the tremendous number of
applications of these materials in ferroelectric memories, piezoelectric and pyroelectric devices. To these
functionalities, controlled adsorption of molecules onto ferroelectrics could be a key feature for heterogenous
catalysis. Differences of 100 K are observed between the desorption temperatures of polar molecules (2propanol1 or acetic acid2), from LiNbO3(0001) exhibiting outwards (P (+)) or inwards (P(-)) polarization. For nonpolar molecules (dodecane2), no dependence on the initial polarization state of the substrate is reported. There is
also an interplay between surface chemical reactions and the ferroelectric polarization state. For instance, oxygen
adsorption at the surface of PbTiO3 is able to reverse its polarization3. The basic phenomena stimulating the
interest in ferroelectrics photocatalysis relies on the ability of charge separation inside a film presenting out-ofplane polarization, since the internal (depolarization) field transports electrons towards the P (+) oriented face and
holes at the opposite face. Therefore, the P (+) face will be active for reduction, and the P(-) face will be active for
oxidation4, as represented in Figure 1.
X-ray photoelectron spectroscopy (XPS) is widely used in the characterization of surfaces and
interfaces. To the well known composition and chemical sensitivity of this technique, recently our group
demonstrated the ability of this technique to quantify of band bendings at charged surfaces and at interfaces
between metals and semiconductors5-9.
In this contribution, I will summarize recent photoemission experiments revealing the interplay between
ferroelectric surfaces and molecular adsorption and photodesorption experiments, by using the Elettra
synchrotron light source and a surface science setup belonging to the National Institute of Materials Physics and
installed at Elettra. The high intensity of the Elettra light source is able to induce the formation of ferroelectric
domains with reversed polarization, owing to the hole accumulation nearby the surface. Spectromicroscopy
photoemission measurements with sub-micrometer spatial resolution revealed the existence of ferrroelectric
domains without compensation of fixed charges, which are expected to be highly chemically active, owing to
their large ability to operate charge separation. Also, a clear dependence of the adsorption of polar molecules on
the surface ferroelectric polarization state was evidenced 10. These experiments promote ferroelectric surface as
valid candidates for catalysis and photocatalysis.
1. Y. Yun, L. Kampschulte, M. Li, D. Liao, and E.I. Altman, J.
Phys. Chem. C 2007, 111, 13951-13956.
2. Y. Yun and E.I. Altman, J. Am. Chem. Soc. 2007, 129, 1568415689.
3. M.J. Highland, T.T. Fister, D.D. Fong, P.H. Fuoss, C. Thompson,
J.A. Eastman, S.K. Streiffer, and G.B. Stephenson, Phys. Rev. Lett.
2011, 107, 187602.
4. Y. Cui, J. Briscoe and S. Dunn, Chem. Mater. 2013, 25, 42154223.
5. N.G. Apostol, L.E. Ştoflea, G.A. Lungu, C. Chirila, L. Trupină,
R.F. Negrea, C. Ghica, L. Pintilie, and C.M. Teodorescu, Appl. Surf.
Sci. 2013, 273, 415-425.
6. N.G. Apostol, L.E. Ştoflea, G.A. Lungu, L.C. Tănase, C. Chirilă,
L. Frunza, L. Pintilie, and C.M. Teodorescu, Thin Solid Films 2013,
545, 13-21.
7. N.G. Apostol, L.E. Ştoflea, G.A. Lungu, C.A. Tache, L. Pintilie,
Figure 1. Charge transport towards surfaces and and C.M. Teodorescu, Mater. Sci. Eng. B 2013, 178, 1317-1322.
possible catalytic activities of both surfaces 8. L.E. Ştoflea, N.G. Apostol, C. Chirilă, L. Trupină, R. Negrea, L.
(reduction for the outwards polarization, oxidation Pintilie, and C.M. Teodorescu, J. Mater. Sci. 2014, 49, 3337-3351.
for the inwards polarization).
9. I. Pintilie, C.M. Teodorescu, C. Ghica, C. Chirilă, A.G. Boni, L.
Hrib, I. Pasuk, R. Negrea, N.G. Apostol, and L. Pintilie, ACS Adv.
Mater. Interf. 2014, 6, 2929-2939.
10. L.E. Ştoflea, N.G. Apostol, L. Trupină, and C.M. Teodorescu, J.
Mater. Chem. A 2014, submitted.
42
S1 L08
ANALYTICAL SOLUTIONS OF EIGENENERGY EQUATIONS OF QUANTUM PARTICLES WITH
APPLICATIONS TO NANOPHYSICS
Victor BARSAN
IFIN-HH & HHF, Magurele - Bucharest
A simple method for solving a class of transcendental equations giving the eigenenergy of a non-relativistic
quantum particle is presented. The method is based on the “algebraization” of the trigonometric functions
entering into the transcendental equations, and transforming them into low degree algebraic equations. Several
examples are presented in detail, with application in the physics of ultra-thin metallic films and photovoltaic
materials.
S1 L09
ENHANCING THE PLASTICITY OF METALLIC GLASSES: NANOCOMPOSITES AND
NANOGLASSES INVESTIGATED BY MOLECULAR DYNAMIC SIMULATIONS
Daniel ŞOPU, Karsten ALBE
Technische Universität Darmstadt, Institut für Materialwissenschaft, Fachgebiet Materialmodellierung,
Petersenstr. 32, D-64287 Darmstadt, Germany
Bulk metallic glasses (BMGs) combine unique mechanical properties, such as high strength and hardness with
substantial fracture toughness. However, their strong tendency towards shear localization results in
macroscopically brittle failure at room temperature which has imposed a barrier to broad commercial
application. In this study, we investigate the influence of various microstructural features on the deformation
behavior of binary Cu64 Zr36 glasses by molecular dynamics computer simulations and discuss how and why
the very same modifications established for enhancing the strengths of crystalline materials, namely the
insertion of solutes, precipitates and grain boundaries, can be used for tuning the mechanical properties of
metallic glasses. First, the influence of crystalline nanoprecipitates on shear band nucleation and propagation is
investigated. In the second part of this talk, we analyze the effect of grain size and composition on the
deformation behavior of nanoglasses. The results reveal that glass–glass interfaces act as structural
heterogeneities, which promote shear band formation and prevent strain localization.
43
S1 L10
FABRICATION OF ONE-DIMENSIONAL ZINC OXIDE NANOSTRUCTURES USING TEMPLATEFREE ELECTROCHEMICAL PATHWAYS
Vlad-Andrei ANTOHE, and Luc PIRAUX
Université catholique de Louvain (UCL), Institute of Condensed Matter and
Nanosciences (IMCN), Place Croix du Sud 1, B-1348 Louvain-la-Neuve, Belgium
The conception of one-dimensional (1D) ZnO nanostructures using straightforward low-cost methods
became a subject of intensive research in the last decade, due to the wide range of applications requiring large
active surface for boosting the device performance while maintaining its small dimensions. Moreover, the design
of such highly-oriented ZnO architectures arranged on top of transparent substrates specifically received
considerable attention due to their potential use within transparent electronics and optoelectronics. In this
context, we will discuss a direct template-free electrochemical deposition (ECD) route to grow oriented ZnO
nanostructures, supported onto various types of solid substrates, such as: Au – coated bulk Si, F-doped SnO2
(FTO) – coated glass and Al-doped ZnO (AZO) – coated glass. The resulted ZnO structures were characterized in
terms of their morphology and crystalline quality. We will also point out the strong impact of the substrate
properties over the shape, size, crystallinity and verticality of the prepared ZnO nanostructures.
The “home-made” Si/Au platforms enabled the growth of large arrays of ZnO nanocolumns exhibiting a
well-defined hexagonal symmetry with an excellent crystallinity. Scanning electron microscopy (SEM)
investigations revealed the potential of this method for obtaining a high degree of verticality and orientation of
the ZnO nanostructures, as well as for controlling their aspect-ratio in an easy manner [1]. In contrast, the
commercially-available Sn-doped In2O3 (ITO) or FTO – based substrates hardly combined the two essential but
antagonistic properties of providing a higher conductivity coupled with a low superficial roughness profile.
Consequently, none of the ECD attempts overcame these limitations to produce vertical ZnO 1D nanostructures,
favoring in contrast the formation of different types of architectures, such as “flower-like” structures, nano-discs
or nano-platelets. Finally, we explored the morphological and electrical benefits provided by “in-house”
prepared thin AZO films acting as high quality transparent electrodes and facilitating the growth of dense arrays
of ZnO vertical nanorods displaying a polycrystalline nature and exhibiting an excellent substrate – enhanced
orientation along ZnO c-axis crystallographic Wurtzite phase [2].
The presented one-step, low-cost and low-temperature ECD approach may be an attractive technique to be
also applied onto substrates with lower thermal toughness, like plastics and/or flexible media. Additionally, the
developed protocol may have great potential to be used in the fabrication processes of modern transparent
electronic and optoelectronic devices, where well-localized, ordered and dense ZnO 1D architectures are desired
to be settled on top of highly transparent and good quality substrates, such as large area multi-touch display
panels or hybrid organic/inorganic photovoltaic elements. For the latter category, it is worth pointing out that the
process of developing AZO – supported ZnO nanorods is particularly promising, because the inorganic material
may borrow the texture and crystalline structure from the collecting electrode, reducing in this way the
potentially existing defects at the interface (associated with possible lattice mismatches) and further improving
locally the electrical transport properties, and thus the overall device efficiency.
[1] V. A. Antohe et al. Nanotechnology 23, 255602 (2012).
[2] V. A. Antohe et al. Appl. Surf. Sci., DOI: 10.1016/j.apsusc.2014.06.031 (2014).
Authors acknowledge financial support from the French Community of Belgium via the Concerted Research
Action (ARC Convention: 13/18-052)
44
S1 L11
EFFECTIVE SEGREGATION COEFFICIENT OF RARE-EARTH IONS IN FLUORITE CRYSTALS
Madalin BUNOIU, Marius STEF and Irina NICOARA
West University of Timisoara, Dept. of Physics, Blvd. V. Parvan 4, Timisoara 300223, Romania
Fluorite crystals (MeF2: Me=Ca, Ba, Sr) are used as a host for applications in laser, opto-electronic
devices and detectors due to its low refractive index limiting nonlinear effects, low phonon energy reducing nonradiative relaxation, wide range of solubility for RE ions, high transparency in a wide wavelength region varying
from VUV to IR, high thermal conductivity and chemical stability and good mechanical properties. Calcium
fluoride (CaF2) crystals doped with various rare-earth (RE) ions have attracted much interest in order to develop
new laser materials. BaF2 is a scintillating crystal, having two fast emission components (195 and 220 nm) and
a slow emission at 310 nm. Among the RE ions, the Er 3+ and Yb3+ ions are more investigated in order to improve
the laser efficiency, both of various alkaline-earth fluorides crystals and glasses. The homogeneous distribution
of the impurity in laser crystals is important because this affects the efficiency of the laser. The spectroscopic
and laser properties of the ErF3 and YbF3 doped CaF2 crystals are well studied [1-3]. Although these crystals are
known as good laser host, surprising, the analysis of the Er 3+ and Yb3+/Yb2+ ions distribution along the CaF2 and
BaF2 crystal has been less investigated.
The goal of this work is to determine the effective segregation coefficient of the Er3+, Yb3+, Yb2+ ions, in
ErF3 and YbF3 doped CaF2 and YbF3 doped BaF2 crystals using the optical absorption method [4, 5].
ErF3 and YbF3 –doped CaF2 crystals and YbF3 doped BaF2 were grown using the vertical Bridgman
method [6]. The optical absorption spectra reveal the characteristic peaks of the Er 3+, Yb3+, Yb2+ ions. The dopant
distribution along two crystals has been investigated using the optical absorption method. The effective
segregation coefficient of the various ions has been calculated using the classical Scheil relationship between the
impurity concentration and the crystal growth conditions. Our study shows that the effective segregation
coefficient of the Er3+ , Yb3+, Yb2+ ions in the CaF2 and BaF2 hosts depends on the doping concentration and on
the host.
[1] Labbe C, Doualan J, Camy P, Moncorge R, Thuau M 2002 Opt. Commun. 209 193
[2] V. Petit, P. Camy, J.L. Doualan, R. Moncorge, J. of Luminesc. 122–123 (2007) 5,
[3] V. Petit, P. Camy, J-L. Doualan, X, Portier and R. Moncorge, Phys. Rev. B78 (2008) 085131
[4] Kuwano Y 1982 J. Crystal Growth 57 353
[5] Sun D, Zhang Q, Wang Z, Su J, Go C, Wang A, Yin S 2005 Cryst. Res. Technol. 40 698
[6] Nicoara D and Nicoara I 1988 Mater. Science and Eng. A 102 L1
45
S1 L12
ELECTROCHEMICAL DEPOSITION OF ORGANOMETALLIC/POLYPYRROLE
COMPOSITES FOR OLED APPLICATIONS
S. POLOSAN
National Institute of Materials Physics R-77125 Bucharest-Magurele, Romania
Neat film of organometallic/polypyrrole (Ppy) composites can be obtained by electrochemical methods
directly on the electrodes, ITO or gold thin layers, deposited on quartz or glasses. Conducting polymer thin films
can be obtained in different ways starting with spinning methods, but the composite organometallic/polypyrrole
require a different approach in order to ensure uniform dispersion of the organometallic in thin layer. Polypyrrole
can be easily doped with IrQ(ppy)2 organometallic compound formed by two types of ligands: phenylpiridine
and quinoline. The photoluminescence measurements of IrQ(ppy) 2 shows two main emissions at 530 nm (2,34
eV) the green one coming from the phenylpiridine ligand and at 640 nm (1,93 eV) the red one coming from the
quinoline ligand.
The IrQ(ppy)2 nanoparticles (1 mM) were dispersed in 0.1 M HCl deionized water and sonicated for 3 h
in an ultrasonic bath. Subsequently, 0.1 M Ppy was gradually dissolved with vigorously magnetic stirring in this
emulsion solution for 30 min. Then, PPy/IrQ(ppy) 2 were electrochemically polymerized at a constant potential of
0.7 V versus Ag/AgCl. A thin layer of about 50 nm was deposited on the ITO/glass substrate in 3 minutes which
was used for spectroscopic characterization
Polymerization through chronoamperometry
Intensity (arb. units)
2000
polypyrol with IrQ(ppy)
2
IrQ(ppy)
2
polypirol
1500
1000
500
0
490
530
570
610
650
690
 (nm)
Fig. 1 SEM patterns of IrQ(ppy) 2:Ppy composite
Fig. 2 PL spectra of IrQ(ppy)2:Ppy composite, Ppy
and IrQ(ppy)2
As can be seen in the PL spectra, the IrQ(ppy) 2:Ppy composite is dominated by the emissions of the
both compounds: polypyrrole and IrQ(ppy)2. Depending of the excitation area of this thin film, the red emission
may be higher or lower in intensity than the green one. The enhancement of the red emission can be explained
through the crystallization behaviors of this compound along the quinoline ligands into a triclinic structure. This
means that the emissions are influenced by the mixture between amorphous and crystalline structures on the thin
film.
46
S1 L13
SENSOR ARRAY FABRICATION BY LASER-INDUCED FORWARD TRANSFER
A. PALLA PAPAVLU1,2, T. LIPPERT2, M. DINESCU1
1) Lasers Department, National Institute for Lasers, Plasma and Radiation Physics, 077125 Magurele, Romania
2) General Energy Research Department, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
Environmental monitoring due to air pollution is a problem of current interest both for the industry, i.e.
automotive (detection of polluting gases from cars) as well as for many research groups. Since sensors are the
main components in products and systems used to detect volatile organic compounds (VOCs) in air, there are
always new and innovative sensor technologies emerging. Several key requirements for sensors include
sensitivity, the minimum concentration of target gases they can detect, response speed, reversibility, energy
consumption, and fabrication costs.
Laser-induced forward transfer (LIFT) is a powerful technique for the deposition of a wide range of materials in
solid or liquid phase. In LIFT, a laser beam is focused through a transparent support plate onto the backside of a
sacrificial layer, i.e. metal or polymer thin film coated with the material to be transferred (donor film). Each
single laser pulse promotes the transfer of the thin film material (donor film) onto a receiver substrate that is
usually placed parallel and facing the thin film at a short distance. The sacrificial layer can be a polymer layer
(triazene polymer TP), which is also called dynamic release layer (DRL). This layer has the purpose to improve
the process efficiency and to reduce the risk of damaging the layer to be transferred.
This work summarizes the developments in DRL assisted LIFT of complex materials such as polymers,
biomolecules, or carbon nanotubes (CNT) for applications as recognizing elements in miniaturized surface
acoustic wave (SAW) resonators and chemiresistor devices.
As the functionality of such sensors depends on the applied laser source, target material, and transfer geometry,
first an optimization of the process parameters is presented.
Following a morphological, structural, and chemical characterization of the active material, i.e. CNT, polymers,
and odorant binding proteins the performance, i.e. the sensitivity, resolution, and response time of the laserprinted devices was evaluated by exposure of the sensor arrays to different toxic vapors. Different sensitivities
and selectivity to the selected chemical agents i.e. dimethyl methylphosphonate, dichloromethane,
dichloropentyhane, ethyl acetate, ammonia, etc. have been measured thus proving the feasibility of LIFT for
applications in chemical sensors and biosensors.
S1 L14
THE EFFECT OF THE SUBSTRATE TEMPERATURE AND THE ACCELERATION POTENTIAL
DROP ON THE STRUCTURAL AND PHYSICAL
PROPERTIES OF SiC THIN FILMS DEPOSED BY TVA METHOD
V.CIUPINĂ1,3, G.PRODAN1, , R.VLĂDOIU1, C.P. POROŞNICU3 , E.VASILE4, C.P.LUNGU3, M.BELC1,
I.M.OANCEA-STANESCU5 , V.DINCA1, A.MANDES1, V.NICOLESCU6,
1
Department of Plasma, Faculty ofApplied Physics and Engineering, Ovidius University, Constanta
3
Academy of Romanian Scientists, Independenţei 54, Bucharest, Romania
3
National Institute for Laser, Plasma and Radiation Physics, , Bucharest, Romania
4
METAV C.D., Bucharest, Romania
5
Faculty Mechanical, Industrial and Marine Engineering,Ovidius University, Constanta
5
CERONAV Constanta
There is a particular interest for SiC due to its physical properties, classified as wide band semiconductor, which
influences its behavior to different stimuli: optical, electrical, mechanical, thermal. Crystalline silicon carbide
was deposited on the carbon support found at different temperatures, as well as for different acceleration
voltages of the plasma system. It was followed the evolution of structural and physical properties depending on
the deposition parameters. Specific techniques were used, TEM, SEM, EDS, ESCA to determine the structural
properties respectively tribological methods, optical absorption, electrical conductivity measurements for
determining physical properties.
Keywords: SiC, TVA, SEM, EDS, ESCA, tribological methods, optical absorption, electrical conductivity
47
S1 L15
RECENT STUDIES ON SOME IRON OXIDE NANOCOMPOSITES AND THIN FILMS
F. IACOMI
Faculty of Physics, Alexandru Ioan Cuza University, 11 Carol I Blvd., 700506-Iasi, Romania
The influence of inter-particle interactions on the functional properties of iron oxide nanocomposites and thin
films is investigated. Iron oxide/MCM-41 (M-M15), iron oxide/polymer (P1-P3) were synthesized using solid
reaction, and making mixtures from siloxane polymer with hydrophobized silica and iron oxide nanoparticles,
choosing certain iron oxide contents (0% - 15% for M-M15 and 2%-6% for P1-P3 respectively) and certain silica
contents (14%, 28%). Nanostructured, hematite thin films (150 nm) were grown on a ceramic substrate by using
a spin-coating method.
Information related to the structure, morphology, electrical and magnetic properties is extracted from XRD,
SEM, TEM, AFM and electrical and magnetic investigations (Fig.1.a). Electron Spin Resonance results allow to
conclude that by controlling the distance between the magnetic particles it is possible to control the dipolar
interaction between the aligned particles and that the chemical neighborhood is important (Fig.1. b-c).
The sensitivity to water and chemical vapors and catalytic activity is also discussed.
a)
c)
b)
d)
Fig.1. a) Grazing XRD patterns of iron oxide/MCM-41 nanocomposites; b) Room temperature ESR spectra of
iron oxide/MCM-41 nanocomposites c) Room temperature ESR spectra of iron oxide/polymer nanocomposites
d). Angular dependence of room temperature ESR signal of hematite thin film.
Aknowledgments
We are grateful for the financial support from IUCN-Romania collaboration project no.54/ theme 04-4-10692009/2014
48
S1 L16
PRESSURE EFFECTS ON THE MAGNETIC BEHAVIOUR OF COBALT IN RARE-EARTH
COMPOUNDS
E. BURZO1), P. VLAIC1), D. KOZLENKO2)
1)
Faculty of Physics, Babes-Bolyai University Cluj-Napoca 400084 Romania
Joint Institute for Nuclear Research, 141980 Dubna Moscow Reg., Russia
2)
The cobalt in rare-earth, R, compounds shows a wide variety of magnetic behaviour as strong or weak
ferromagnetism as well as an exchange enhanced paramagnetism. The effect of pressure on the cobalt magnetic
behaviour in RCo5, R-Co-B and RCo2 compounds is analysed. In case of a weak ferromagnetism there is a direct
collapse of cobalt moment, while when shows strong ferromagnetism, a transition from high to low spin state is
observed. A decoupling of magnetic sublattices are often evidenced and correlated with the evolution of
exchange fields. A critical field Hex = 74 T is necessary for supporting an ordered cobalt moment. Band structure
calculations show that the pressure dependence of cobalt moments is the result of the shift, on the energy scale,
of the spin-up and spin-down sub-bands. There is an instability in thermodynamic state when are similarly high
values of spin-up and spin-down DOS, respectively.
S1 L17
EXCITATIONS OF A SHIBA MOLECULE
N. Y. YAO1, C. P. MOCA2,3, I. WEYMANN4, J. D. SAU5, M. D. LUKIN1, E. A. DEMLER1, G. ZARAND2
1
Physics Department, Harvard University, Cambridge, MA 02138, U.S.A.
2
BME-MTA Exotic Quantum Phase Group, Institute of Physics,
Budapest University of Technology and Economics, H-1521 Budapest, Hungary,
3
Department of Physics, University of Oradea, 410087, Oradea, Romania
4
Facult of h sics, dam Mic iewic Universit , - 4, o nan , Poland
5
Joint Quantum Institute and Condensed Matter Theory Center,
Department of Physics, University of Maryland, College Park, Maryland 20742, U.S.A.
We analyze the phase diagram associated with a pair of magnetic impurities trapped in a superconducting host.
The natural interplay between Kondo screening, superconductivity and exchange interactions leads to a rich
array of competing phases, whose transitions are characterized by dis- continuous changes of the total spin. Our
analysis is based on a combination of numerical renor- malization group techniques as well as semi-classical
analytics. In addition to the expected screened and unscreened phases, we observe a new molecular doublet
phase where the impurity spins are only partially screened by a single extended quasiparticle. Direct signatures
of the various Shiba molecule states can be observed via RF spectroscopy.
49
S1 L18
MATRIX-ASSISTED PULSED LASER EVAPORATION: APPLICATION TO BIOPOLYMER THIN
FILM ASSEMBLIES
C. RISTOSCU1, F. SIMA1, E. AXENTE1, L. E. SIMA2, M. ERGINER3, M. S. EROGLU3, N.
MIHAILESCU1, S. M. PETRESCU2, E. TOKSOY ONER3, I. N. MIHAILESCU1
1
National Institute for Lasers, Plasma and Radiation Physics, POB MG-36, Magurele, Ilfov, Romania;
[email protected]
2
Department of Molecular Cell Biology, Institute of Biochemistry, Romanian Academy, 296 Splaiul
Independentei, 060031, Bucharest 17, Romania
3
Marmara University, Turkey
Laser-assisted methods prove some key advantages over the other deposition techniques: the accurate control of
the layer thickness and/or expulsed material, absence of contamination, uniform distribution of material over
quite large areas and rather easy synthesis of multistructures. Matrix-Assisted Pulsed Laser Evaporation
(MAPLE) method was particularly developed to provide a soft laser transfer of organic and/or biologic
materials. Extremophilic microorganisms provide non-pathogenic products, suitable for uses in food industry,
pharmacy and cosmetics as emulsifiers, stabilizers, gel agents, coagulants, thickeners and suspending agents.
One exopolisacharide extremophile producer is the halophilic Halomonas sp. AAD6 bacteria, which secrets high
level of levan. The transfer of pure levan (L) and oxidized levan (OL) by MAPLE was achieved without any
addition of plasticizers or pigments [1]. We mention that the deposition of this delicate biomaterial was
unapproachable by any other laser techniques. The coatings preserved the bulk composition as demonstrated by
the IR absorption data. The samples presented a compact structure, good adhesion to substrate and a uniform,
homogenous nanostructured surface. Cell viability and proliferation studies confirmed the biocompatible
behavior of the synthesized nanostructures.
We introduce a new method, combinatorial MAPLE (C-MAPLE) for the fabrication of organic biopolymer thin
films [2,3] (Fig. 1).
Fig. 1. Design of C-MAPLE experimental set-up.
Structures with compositional gradient are obtained by the simultaneous laser vaporization of two distinct
targets. Synchronized MAPLE of L and OL cryogenic targets was applied in order to transfer under protection
and assemble a two-compound biopolymer film structure. FTIR micro-spectroscopy confirmed the existence of a
composition gradient along the length of the sample. Modification of chemical composition from L to OL and
the physical texture stayed at the origin of the improved accumulation of cells on discrete film regions (different
from the two ends) as compared with all other film areas. In-vitro assays illustrated characteristic responses of
cells to specific surface regions. The cell response induced by the compositional gradient was investigated. Cells
attached along the gradient in direct proportion with oxidized levan concentration.
The proposed method opens the possibility to both combine and immobilize two or more organic materials on a
solid substrate in a well defined manner by laser evaporation under protection. Moreover, the versatility of CMAPLE allows for the synthesis of new hybrid materials by tailoring the irradiation conditions in correlation
with the thermo-physical properties of the starting materials which are used for libraries fabrication.
1) Felix Sima, Esra Cansever Mutlu, Mehmet S. Eroglu, Livia E. Sima, Natalia Serban, Carmen Ristoscu,
Stefana M. Petrescu, Ebru Toksoy Oner, Ion N. Mihailescu, “Levan Nanostructured Thin Films by MAPLE
ssembling”, Biomacromolecules, Volume 12, Issue 6, June 2011, pp 2251–2256
2) F. Sima, E. Axente, L. E. Sima, U. Tuyel, M. S. Eroglu, N. Serban, C. Ristoscu, S. M. Petrescu, E. Toksoy
Oner, I. N. Mihailescu, “Combinatorial Matrix-Assisted Pulsed Laser Evaporation: Single-step synthesis of
biopol mer compositional gradient thin film assemblies”, Applied Physics Letters 101, 233705 (2012)
3) E. Axente, F. Sima, L. E. Sima, M. Erginer, M. S. Eroglu, N. Serban, C. Ristoscu, S. M. Petrescu, E. Toksoy
Oner, I. N. Mihailescu, “Combinatorial MAPLE gradient thin film assemblies signalling to human osteoblasts”,
Accepted for publication in Biofabrication, April 2014
50
ORAL PRESENTATIONS
S1 O01
W-Mg ALLOY FILMS DEPOSITED by TVA on HYDROGENATED EUROFER SUBSTRATES for
PLASMA FACING COMPONENTS
Simona G. GRECULEASA1,3, P. PALADE1, G. SCHINTEIE1, A. KUNCSER1,3, A. LUNGU1, C.
POROSNICU2, I. JEPU2, C.P. LUNGU2, G. FILOTI1, V. KUNCSER1
1
National Institute for Materials Physics, P.O.Box MG-7, 77125, Bucharest-Magurele, Romania
National Institute for Laser, Plasma and Radiation Physics, 77125, Bucharest-Magurele, Romania
3
Bucharest University, Faculty of Physics, 077125, Bucharest-Magurele, Romania
2
Keywords: plasma facing components, hydrogenation, atomic interdiffusion, XPS, CEMS
Special reduced-activation ferritic / martensitic (RAFM) steels such as complex Fe alloys (Eurofer) coated by
self passivating W-based alloys are of high importance in the design of plasma facing components for future
tokamak-like nuclear fusion reactors. Two W0.2Mg0.8 films (50 nm thick) have been deposited by thermionic
vacuum arc (TVA) method on Eurofer slabs in different atmospheres (sample B in an atmosphere richer in
oxygen than sample A). In order to simulate the impact of hydrogen/deuterium absorption, we have applied
thermal treatments in hydrogen atmosphere on the Eurofer slabs. Complex analyses of the involved samples
have been performed, both before and after annealing, by X-ray diffractometry, scanning electron microscopy,
energy dispersive spectroscopy, X-ray photoelectron spectroscopy and conversion electron Mössbauer
spectroscopy. The untreated Eurofer substrate presents a bcc structure of average alloy composition approaching
Fe0.9Cr0.1 (with Al, W and Mg dopants < 1% at.). The XPS data show a high degree of oxidation of the surface
with an increased Cr and Al relative content (12% at. and 14% at) at a depth of 3 nm from the surface whereas
the CEMS spectra prove significant compositional deviations from an homogeneous alloy. While the alloy
composition is homogeneous in the surface according to the EDS elemental maps, the only consistent
explanation of the experimental data infer a depth dependent composition in the first 100 nm, with Cr and Al
content increasing toward the surface. The hydrogenation increases additionally the expulsion of the Cr and
mainly the Al atoms toward the surface of the Eurofer substrate. After the alloy film deposition, the W content is
prevailing over Mg at or close to the surface, in spite of the designed average composition. Sample B is more
oxidized than sample A, in accordance to the preparation conditions. It is shown that the hydrogenation
treatments induce considerable changes in both the surface properties of the steel as well as of the deposited W
based films.
Aknowledgements: This work was supported by the Romanian National Program and the European
Communities under the contract of Association between EURATOM and MEdC (project founded by the
EUROATOM consortium).
51
S1 O02
Ba1-xSrxTiO3 FERROELECTRIC SOLID SOLUTIONS OF HIGH TECHNOLOGICAL IMPORTANCE
Liviu NEDELCU 1, Raluca BACSEI 2, Nicoleta VINETICU 2, Sorin Ion JINGA 3,
Radu MANU 4, Constantin Paul GANEA 2, Horia V. ALEXANDU 2
1
2
National Institute of Materials Physics, Bucharest-Magurele, Romania
University of Bucharest, Faculty of Physics, Bucharest-Magurele, Romania, [email protected]
3
Universit “ olitehnica” of Bucharest, Romania
4
Ovidius University of Constanta, Romania
The ferroelectric ceramic of solid solution family Ba1-xSrxTiO3 (BST) for the entire substitution range
(0 < x < 1), present a major technological interest. It has applications in DRAM memories, in high frequency
communication due to the nonlinear variation of their permittivity with the applied electric field, etc. The Curie
temperature of the continuous solid solutions decreases monotonically with the strontium content. Thus, the
transition temperature and hence the electrical properties of BST can be tailored over a broad temperature range,
in
order
to
meet
the
requirements
of
various
electronic
applications.
Ba1-xSrxTiO3 solid solutions with x = 0.20 and 0.40 were prepared by solid-state reaction and were sintered at
several temperatures between 1300 and 1450 oC. X-ray diffraction and scanning electron microscopy have been
used for structural and morphological characterization.
The complex dielectric function dispersion of the BST samples was investigated using Quattro
Cryosystem
with
Alpha
Analyzer
(Novocontrol)
on
the
frequency
range
10-2 Hz - 1 MHz and on the temperature range – 120 oC - + 150 oC. Experimental data has shown a linear
decrease of the Curie point Tc (oC) ≈ 120 – 360 x, versus x strontium content, according to literature data [1, 2].
The relaxation time, found in Arrhenius coordinate, shows for BST 40 activation energy of 0.6 ÷ 0.8 eV, for
1300 – 1400 oC and more than 1 eV for 1450 oC thermal treatment. An extensive analysis of literature data [3]
has shown the composition x = 0.4 Sr content is on the border of some electrical parameters changes (e.g. peak
changes). Cole-Cole correlations have shown (for the first time) three relaxation processes having the relaxation
time of the order: LOW ~ 102 s, MEDDIUM ~ 10-6 s, and HIGH ~ 10-8 s [4]. These results strongly suggest the
BST materials, particularly in the paraelectric phase, are suitable for important microwave applications.
1. H.V.Alexandru et al., Mater. Sci. Eng. B 109 (2004) 152.
2. H.V.Alexandru et al., Appl. Surf. Sci. 253 (2006) 354.
3. J.-H. Jeon, J. Eur. Ceram. Soc. 24 (2004) 1045.
4. R. Bacsei, Ph. D. thesis, University of Bucharest, 2014.
Acknowledgements: This work was partially supported by a grant of the Romanian Ministry of Education and
Research, CNCS – UEFISCDI, project number PN-II-ID-JRP-RO-FR-2012-0160.
52
S1 O03
MAGNETIC RELAXATION IN FERROFLUIDS WITH DIFFERENT VOLUME FRACTIONS OF
MAGNETITE.
G. SCHINTEIE1, P. PALADE1, N. IACOB2,3, L. VEKAS4 and V. KUNCSER1
1
National Institute of Materials Physics, PO Box MG-7, 077125, Magurele, Romania
National Institute for Lasers, Plasma and Radiation Physics, PO Box MG-36, Romania
3
Faculty of Physics, University of Bucharest, 077125, -Magurele, Romania
4
Laboratory of Magnetic Fluids, Centre for Fundamental and Advanced Technical Research, Romanian,
Academy-Timisoara Division, 300223, Timisoara, Romania
2
Ferrofluid samples of different volume fractions ranging from 0.005 to 0.2, consisting of magnetite
nanoparticles coated with oleic acid and dispersed in a non-polar organic solvent were studied by SQUID
magnetometry and temperature dependent Mössbauer spectroscopy in order to obtain useful information about
magnetic relaxation phenomena, interparticle interactions, blocking temperature and anisotropy energy barriers.
Both Neel and Brownian relaxations have been experimentally put in evidence in case of the analyzed
ferrofluid samples. The prevailing mechanism depends on the temperature and specific magnetic parameters of
nanoparticles. New criteria to separate the two relaxation contributions for a correct interpretation of the
experimental relaxation data are proposed and exemplified.
Fig.1: Tipically ZFC and FC magnetization curves
specific to ferrofuids samples with high volume
fraction of magnetite. Measurements have been done
in 100 Oe applied field. The low temperature
maximum of the ZFC curve (lower curve) offers
relevant information about the Neel relaxation
mechanism whereas the jumps at higher temperatures
are related to starting Brownian relaxation .
In case of high volume fraction systems, the interparticle interactions plays an essential role, their
effects being of crucial role in respect to different applications from rotating seal [1,2] to hyperthermia
treatments[3] (in the last case, mainly due to the non-uniform dispersion of the nanoparticles in the tissue). The
interparticle interactions have drastic influence on the relaxation mechanisms, as will be also discussed. Specific
deviations from the superparamagnetic behavior in the ZFC-FC curves are connected to the defreezing
mechanism and may offer information about the Brownian relaxation. Other types of specific measurements
giving information about the two relaxation mechanisms are also provided.
.
1.
R E Rosensweig Sci. Am. 247 136(1982)
2.
Ray K, Moskowitz B and Casciari R J. Magn. Magn.Mater. 149 174(1995)
3.
Fortin J, Wilhelm C, Servais J, M´enager C, Bacri J and Gazeau F J. Am. Chem. Soc. 129 2628(2007)
53
POSTERS
S1 P01
MORPHOLOGICAL AND COMPOSITINAL INVESTIGATIONS OF THE TRIBOLOGICAL
COATINGS WITH TERNARY COMPOSITION FROM COMPOUND MATERIALS, OBTAINED BY
DC MAGNGNETRON SPUTTERING DEPOSITION METHOD
A. O. MATEESCU, G. MATEESCU, L. CRACIUN, C. IONESCU, I. BURDUCEA
“Horia Hulubei” National Institute of h sics and Nuclear Engineering, Romania
The purpose of this work is to make the first investigations of the complex tribological coatings with
ternary composition from compound materials and with a structure of monolayer or multilayer-type, from the
following compound materials: Ti/TixNy; TiB2/ TixByNz; WC/WxCyNz, using Ti, TiB2 and WC sputtering targets.
For obtaining of the monolayer-type structures of Ti+TiB2+WC the DC standard magnetron sputtering
deposition method was used and for obtaining of the monolayer-type structures of TixNy+TixByNz+WxCyNz the
DC reactive magnetron sputtering deposition method was used, with N2 as reactive gas, with simultaneous
working of 3 guns/ magnetron devices. The multilayer type structure of: TixNy/TixByNz/WxCyNz was obtained by
successively deposition of the component materials by DC reactive magnetron sputtering deposition method.
The coatings were investigated by using Atomic Force Microscopy and Rutherford Backscattering
Spectrometry as analyze and measurement methods.
Surface topography, roughness and section analysis of the coating surface layer were examined by
MultiMode NanoScope IIID Controller atomic force microscope working in the so-called tapping mode. Images
were taken using a TESP (0.01-0.025 Ohm-cm Antimony (n) doped Si) tip at 1 Hz scan rate.
The Rutherford Backscattering Spectrometry (RBS) as a nuclear measurement & analysis technique,
with a high resolution, uses the irradiation of the sample that must be analysed with a well collimated and
accelerated mono-energetic beam of H or He ions with energy in the field of MeV (usually: 1-2 MeV).
This work is based on a Patent of Gheorghe Mateescu and Alice-Ortansa Mateescu granted by the
Romanian State Office for Inventions and Trademarks (OSIM) in 2013.
54
S1 P02
MECANICAL AND TRIBOLOGICAL BEHAVIOUR OF THE MULTILAYER DRY LUBRICANT
COATINGS WITH TERNARY COMPOSITION FROM COMPOUND MATERIALS
(TixNy; TiB2/ TixByNz; WC/ WxCyNz)
A. O. MATEESCU1, G. MATEESCU1, L. CRACIUN1, C. IONESCU1, C. SAMOILA2, D. URSUTIU2, D.
MUNTEANU2, D. CRISTEA2, V. JINGA2
1
“Horia Hulubei” National Institute of h sics and Nuclear Engineering, Romania
2
Transilvania University of Brasov, Romania
The Dry Lubricant Coatings with ternary composition from the following compound materials: TixNy;
TiB2/ TixByNz; WC/ WxCyNz were obtained by using DC standard or reactive magnetron sputtering deposition
method.
The multilayer-type structures of: one package of three constituent layers 1x(TiNx/TiB2/WC), five
packages of three constituent layers 5x( TixNy/TixByNz/WxCyNz), with constant composition for each layer and six
packages of five constituent layers with variable composition of the three constituent materials for each layer
6x{5x
[(TixNy+TixByNz+WxCyNz)1/
(TixNy+TixByNz+WxCyNz)2/
(TixNy+TixByNz+WxCyNz)3/
(TixNy+TixByNz+WxCyNz)4/ (TixNy+TixByNz+WxCyNz)5]}
were investigated by: Atomic Force Microscopy,
Hardness Test, Scratch Test and Pin-Ball Tribometer Test, as analyze and measurement methods
Mechanical properties of the thin films at nanometer level were evaluated by using AFM
nanoindentation technique. A diamond tip mounted on a stainless steel cantilever was used. In order to obtain a
good statistics The samples were indented using the option Auto Indent Mode, that allow to set up the number of
the lines, columns and the space between them.
The CSM Table Top Platform that contains the standard Micro/Nanoindentation head (NHT) and the
standard Micro scratch tester head (MST) into a small and simple-to-use instrument was used for evaluation of
the tribological parameters.
Acknowledgments
This work is based on a Patent of Gheorghe Mateescu and Alice-Ortansa Mateescu granted by the
Romanian State Office for Inventions and Trademarks (OSIM) in 2013.
55
S1 P03
AN AFM AND SEM STUDY OF SOME DENTAL RESTORATIVE MATERIALS
CHICEA Dan 1,2, BOŢA Gabriela3, CHICEA Liana-Maria3, CHICEA Radu 3, ŞTEF Laura 3
1- Department of Environmental Sciences, Lucian Blaga University, Dr. Ion Ratiu str., no 5-7, Sibiu, 550012,
ROMANIA
2 - Pediatric Respiratory Medicine Research Center (CCMRP), Str. Pompeiu Onofreiu Nr. 2 – 4, Sibiu,
ROMANIA
3 – Faculty of Medicine, Lucian Blaga University, Lucian Blaga str. No 2A, Sibiu, Romania
A dental restoration is a material used to restore the morphology, integrity and functionality of the
missing tooth structure. There is a big variety of materials that are currently approved and used in the EU
countries. Amalgam is still used in most of the countries, except Norway, Sweden and Denmark where it is
banned because of the controversy related to the Hg content. A review of different studies states that dental
amalgam fillings leach mercury into the mouth, in different questionable amounts, in respect of being high
enough to be a risk to health.
One preferred alternative is composite resin fillings. They are a mixture of powdered glass and plastic
resin. Most composite resins harden with light exposure of a certain wavelength. A topography study of
amalgam and resin filling was carried on using Atomic force microscopy (AFM) and Scanning electron
microscopy (SEM), which employed essentially different physical processes for producing images. A grain
analysis was carried on and the scanning parameters and the results are presented in detail. A discussion
regarding the grain structure and the mechanical properties is presented, as well.
An AFM 3D topography image of one of the composite resins is presented below.
Acknowledgement: We are especially indebted to Total Spectrum SRL (http://www.total-spectrum.ro/) for
access to the Phenom Pro Desktop SEM.
References
1. Dental Amalgam: Myths vs. Facts, (Press release), American Dental Association.
2. Bernardo, Mario, Survival and reasons for failure of amalgam versus composite posterior restorations
placed in a randomized clinical trial, J Am Dent Assoc. vol. 38, 779-783, 2007.
56
S1 P04
PARAMETRIC MODELING OF FIRST-ORDER PHASE TRANSITIONS IN THE PRESENCE OF AN
INTERMEDIATE METASTABLE STATE
Ghennadii GUBCEAC, Florentin PALADI
Theoretical Physics Department, Faculty of Physics and Engineering, Moldova State University, 60 A. Mateevici
str., Chișinău, Moldova
The modeling of phase transitions and the analysis of the role of an intermediate liquid state in irreversible
relaxation processes at low temperatures were performed. As an example, one can consider the systems with two
stable states (L1 and C that means liquid and crystalline, respectively, and the third one – intermediate fluid
state, namely L2). Such L2 state has been experimentally discovered in supercooled liquids [1]. The models
include one order parameter and three control parameters in the Landau-type kinetic general potential of 6th
degree, and have been developed to study the impact of both asymmetry (heterogeneity) and external field on
phase transitions in the presence of an intermediate fluid state. First of all, the intrinsic dynamics are studied, and
the mean transition time is calculated. We noticed that the presence of the intermediate liquid state may indeed
enhance the nucleation rate, and, furthermore, an increase in the heterogeneity of system accelerates the
transition dynamics, while the presence of an external field would increase the mean transition time. In the
previous work, analytical solutions were also obtained according to the Descartes-Euler method for solving
polynomial equations [2]. Depending on the values of
its control parameters, the potential has one, two or
three possible minima, and the problem dealt with the
construction of the equilibrium phase diagrams. It is
also worth mentioning that the presently obtained
results are general and suggest a complete set of
different transition scenarios in the entire parameter
plane.
The shape of kinetic potential U (x) involving a single
order parameter x is shown in Fig. 1, corresponding to
a, c and b which are two minima, and a central
maximum. The system is thus most likely to be found at
a or c.
In 1940 Kramers introduced what is called the Kramers
equation in which he considered motion under the
Fig.1. Plot of p s x  and U  x  for a double well
influence of a potential which was double welled [3].
potential in case of single order parameter
1. Paladi F., Oguni M., Anomalous generation and extinction of crystal nuclei in nonequilibrium supercooled
liquid o-benzylphenol. Physical
doi:10.1103/PhysRevB.65.144202.
Review
B,
2002,
Vol.
65,
No.14,
144202
(6
pages),
2. Barsuk A.A., Gamurari V., Gubceac G., Paladi F., Bifurcation and stability analysis for phase transitions in
the presence of an intermediate state: A general solution. Physica A, 392(9), p. 1931 – 1945 (2013),
doi:10.1016/j.physa.2013.01.036.
3. Gardiner C.W., Handbook of Stochastic Methods: for Physics, Chemistry and the Natural Sciences 3rd ed.
Berlin: Springer, 2004, 415p. ISBN 9783540208822
57
S1 P05
SYNTHESIS AND CHARACTERIZATION OF SOME MAGNETIC NANO-WIRES BY USING
ANODIZED ALUMINA SHEET AS TEMPLATE
Daniela RUSU1, Alina CANTARAGIU2, Constantin GHEORGHIES2, Antoaneta ENE2 ,
Nistor NICUSOR2
1
S.C. Automobile DACIA S.A., (Renault Technologie Roumanie), UMCD-Department ACU, Mioveni, Arges,
Uzinei Street, No.1-3, 115400, Romania
2
Dunarea de Jos University of Galati, Faculty of Sciences and Environment, Department of Chemistry, Physics
and Environment, 47 Domneasca St, 800008 Galati, Romania,
e-mail: [email protected]
The aim of this paper was synthesis of Ni-Co and Ni-Co/barium ferrite (BaFe) nano-wires in sulfamate
electrolyte by using anodic aluminum oxide (AAO) as template. Self-ordered porous AAO membranes have
been fabricated and used as templates in order to produce Ni-Co/BaFe nano-wires. Morphological and structural
studies of nano-wires have been performed by Scanning Electron Microscope (SEM) and X-Ray Diffraction
(XRD), respectively. Energy Dispersive X-Ray Analysis (EDAX) was used for determination of the chemical
composition. The nucleation process of nano-wires was monitored by galvanostatic analysis. Our investigations
showed the formation of the Ni-Co and Ni-Co/BaFe nano-wires by incorporating nano-particles during
electrodeposition process. The magnetic investigations have been performed by using Superconducting Quantum
Interference Device (SQUID) and the influence of the BaFe particles embedded in Ni-Co wires was revealed.
Keywords: AAO templates, nano-wires, microstructure, magnetic hysteresis.
58
S1 P06
FIRST PRINCIPLES INVESTIGATIONS ON THE HALF-METALLIC PROPERTIES OF THE NEW
FULL-HEUSLER COMPOUND Co2YSb
Anca BIRSAN1,2, Petru PALADE1, Victor KUNCSER1
1
National Institute of Materials Physics, 105 bis Atomistilor Street, PO Box MG-7, 077125 Magurele-Ilfov,
Romania
2
University of Bucharest, Faculty of Physics, 105 Atomistilor Street, PO Box MG-11, 077125
Magurele-Ilfov, Romania
Full-Heusler materials [1] with half-metallic properties [2] have been attracting extensive research
interest in the recent years, due to their suitability for providing spin polarized currents.
In this context, we report results of first principles investigations, obtained within the Density
Functional Theory framework, as applied on a new full-Heusler compound, Co2YSb. The magnetic properties
derived from the electronic structure of this compound are analyzed. It is proven that the ferromagnetic state for
a L21 lattice geometry (Cu2MnAl - type) is energetically more favorable than paramagnetic and
antiferromagnetic states, in bulk materials. The majority spin channel presents metallic behavior, while the
minority spin channel is semiconducting with an energy band gap of 0.435 eV, as obtained at the equilibrium
lattice parameter of 6.41 Ǻ. Moreover, the compound keeps its half metallic ferromagnet (HMF) behavior with a
complete spin polarization for any lattice parameter ranging from 6.032 to 6.526 Å (see also the figure). The
calculated total magnetic moment is 2µB, at T= 0K.
The theoretically proven high spin polarization and the relative low magnetic moment indicate the
Co2YSb Heusler compound as a potential attractive material to be used in spin torque transfer magnetic random
access memory devices.
References:
[1] Heusler Fr. Verh Deutsch Phys Ges 1903;5:219.
[2] de Groot RA, Mueller FM, van Engen G, Buschow KHJ. Phys Rev
Lett 1983;50:
2024.
Acknowledgments:
This work was financially supported from the projects PNII IDEI
75/2011 of the Romanian Ministry of Education Research, Youth and
Sport. Anca Birsan would like to acknowledge the financial support
from European Social Fund (POSDRU/159/1.5/S/137750).
Fig: The positions of lowest unoccupied states
from the conduction band (solid red circles) and
of highest occupied states from valence band
(solid black squares) of total DOSs (minority
spin channel) for Co2YSb as function of lattice
parameter.
59
S1 P07
TERAHERTZ TIME-DOMAIN SPECTROSCOPY INVESTIGATIONS ON BULK AND FILM
MICROWAVE DIELECTRICS
M. G. BANCIU 1, L. NEDELCU 1, C. CHIRILA 1, D. GEAMBAŞU 1, T. FURUYA 2, and M. TANI 2
1
2
National Institute of Materials Physics, Bucharest-Magurele, Romania, [email protected]
Research Center for Development of Far-Infrared Region (FIR), University of Fukui, Japan, [email protected]
Materials with improved characteristics as low loss, high dielectric constant and enhanced thermal
stability are required by communication systems, which tend to migrate toward higher frequencies in order to
avoid problems associated with the overcrowded electromagnetic spectrum.
The continuous evolution of far-infrared technology allowed the development of required systems to
adequately process the Terahertz waves [1]. After the coverage with essential technology of the so-called “THz
gap”, the THz science continued to evolve [2, 3]. In this work, Terahertz Time Domain Spectroscopy (THzTDS) was employed in order to investigate materials with special characteristics in microwave range [4]. This
method allows the measurement of amplitude and phase of the THz signal. Therefore, as an advantage compared
to such methods as Fourier Transform Infra-Red (FTIR) method, THz-TDS provides both the refraction index
and dielectric loss without using any approximation derived from Kramers-Kröning relations [1]. The equipment
used for measurements in THz range was the IRS 2000 pro Time-Domain Spectrometer from Aispec, which
allowed measurements up to 7 THz for very low loss samples.
In the work, there are discussed THz-TDS measurements on barium neodymium titanate, zirconium tin
titanate and barium magnesium tantalite bulk low dielectric-loss materials. Moreover, barium strontium titanate
thin films deposited by PLD (Pulsed Laser Deposition) on MgO substrate were also investigated in THz.
Acknowledgements: This work was partially supported by a grant of the Romanian Ministry of
Education, CNCS-UEFISCDI, project number PN-II-ID-PCE-2012-4-0654”.
References
1. K. Sakai, Ed.”Terahertz Optoelectronics”, Springer-Verlag Berlin (2005).
2. M. Tani, K.-S. Lee, X.-C. Zhang, “Detection of terahertz radiation with low-temperature-grown GaAs-based
photoconductive antenna using 1.55 m probe”, App. Phys. Lett., vol. 9, 1396-1398 (2000).
3. M. Tani, T. Kinoshita, T. Nagase, K. Horita, C. T. Que, E. Estacio, K. Yamamoto, M. Bakunov, “Nonellipsometric detection of terahertz radiation using heterodyne EO sampling in the Cherenkov velocity matching
scheme”, Opt. Express, Vol. 21, #184785 (2013).
4. M. G. Banciu, L. Nedelcu, K. Yamamoto, S. Tsuzuki, and M. Tani, “THz-TDS investigations on dielectrics
for microwave applications”, Proceedings of the 5 th International Workshop on Far-Infrared Technologies 2014
(IW-FIRT 2014), University of Fukui, Japan, 5-7 March (2014).
60
S1 P08
NEW APPROACHES FOR TUNING SPECIFIC ABSORPTION RATES IN MAGNETIC FLUID
HYPERTHERMIA
N. IACOB1,2, G. SCHINTEIE3, D. TOADER1, L. VEKAS4 and V. KUNCSER3
1
National Institute for Lasers, Plasma and Radiation Physics, PO Box MG-36, Romania
2
Faculty of Physics, University of Bucharest, 077125, -Magurele, Romania
3
National Institute of Materials Physics, PO Box MG-7, 077125, Magurele, Romania
4
Laboratory of Magnetic Fluids, Centre for Fundamental and Advanced Technical Research, Romanian,
Academy-Timisoara Division, 300223, Timisoara, Romania
Magnetic hyperthermia (MHT) is a potential therapeutic tool in treatment of cancer relying on thermal
effects generated by magnetic relaxation processes [1] in magnetic nanoparticles (MNPs) subjected to RF
magnetic fields. A temperature increment in malign human tissues by only a few Celsius degrees could change
the functionality of the cellular structures in order to induce the apoptosis process. The blocking temperature of
MNPs [2] plays a fundamental role in MHT while depending on its relationality to the sample temperature, could
modify substantially the heat transfer mechanism (hysteretic losses versus superparamagnetic relaxation). On the
other hand, the blocking temperature can be tuned for a same nanoparticulate system by either changing the
frequency of the field or applying low constant (DC) magnetic fields in order to tune the magnetic relaxation
time. There is this second procedure which we have chosen in order to compare relaxation mechanisms and
specific absorption rates (SARs) in ferrofluid samples of high and low volume fraction subjected to a RF
magnetic field. Specific procedure for the correct evaluation of SARs [3] are also discussed in regard to volume
fraction values.
References:
[1] R.E. Rosensweig, “Journal of Magnetism and Magnetic Materials”, 252, (2002) 370–374
[2] G Schinteie et al., “J. Phys. D: Appl. Phys”, 46 (2013), 395501, (8pp)
[3] N. Iacob et al, “A new approach for an improved experimental SAR evaluation in magnetic fluid
hyperthermia” sent to Applied Physics Letters.
Acknowledgements:
Nicusor
Iacob
would
like
to
Social Fund (POSDRU/159/1.5/S/137750).
acknowledge
the
financial
support
from
European
61
S1 P09
MONTE CARLO TYPE INVESTIGATIONS ON THE NUCLEATION PROCESSES IN SOFT
MATTER SYSTEMS
C. BERLIC1, V. BARNA1, B. MANOLESCU1 and BEATRICE MAHLER2,3
1
University of Bucharest, Faculty of Physics, PO Box Mg-11, 077125,Bucharest, Romania
Universit of Medicine and harmac “Carol Davila” Bucharest, Facult of Medicine, No. 8 Eroilor Sanitari
Blvd., Bucharest
3
"Marius Nasta" Pneumology Institute, No. 90 Soseaua Viilor, Bucharest
2
Contrasting to micro-molecular substances, as a subfield of soft matter systems, polymers consist of
long, linear or branched chains, covering a broad distribution of molecular lengths. Usually, polymers solidify as
very tiny crystals dispersed in an amorphous matrix and interconnected by disordered chains randomly disposed.
In polymer solutions or melts, the macromolecules are entangled, giving rise to bunches of interpenetrated
random chains. The kinetics of crystallization of polymers is based on the appearance and growth of crystalline
regions which expand over the volume of the polymer during the transformation. Understanding the kinetics of
crystallization of polymers is very important for the manufacturing process and controlling of the finished
product properties. Mechanical, electrical, optical properties and thermal stability - all of them depend on the
crystal size distribution and the degree of crystallinity. The macroscopic study of the crystallization process is
based on recording the evolution of the crystalline fraction of the material as function of the time.
The standard method of analyzing the phase transformation of polymers is based on the now classical
Kolmogorov–Johnson–Mehl–Avrami (KJMA) theory. Starting from the probabilistic method of Kolmogorov,
continuing with the mean field approximation of Johnson and Mehl, Avrami assumed that the semicrystalline
polymer structure may be described by a two-phase model: a crystalline and a liquid phase. The main goal of the
Avrami equation is to obtain the overall crystallization rate constant, k, and the Avrami index, n.
By means of Monte Carlo simulations, we studied the transition process behavior in soft matter
systems, when induced by an instantaneous or a sporadic nucleation mechanism. We took into account
simulations in 1, 2 and 3-Dimensional spaces and we calculated the overall crystallization rate constants and the
Avrami indices for various starting conditions. The results were compared with the predictions from the KJMA
theory and we conclude that our computational model is in excellent agreement.
[1]. C. Berlic, V. Barna, B. Manolescu , D. Dena; Digest J of Nanomaterials And Biostructures 8,4,1845 (2013).
[2]. C. Berlic, V. Barna, B. Manolescu , D. Dena; Digest J of Nanomaterials And Biostructures 9,1,197 (2014).
[3] H. Janeschitz-Kriegl, Crystallization Modalities in Polymer Melt Processing. Fundamental Aspects of
Structure Formation, Springer-Verlag Wien (2010).
[4] G. Allegra (Ed.), Interphases and Mesophases in Polymer Crystallization I, Advances in Polymer Science,
180, Springer Verlag (2005).
[5] A. S. Myerson (Ed.), Molecular Modeling Applications in Crystallization, Cambridge University Press,
Cambridge (1999).
[6] P. Pasini, C. Zannoni, S. Žumer (Eds.), Computer Simulations of Liquid Crystals and Polymers, Kluver
Academic Publishers, Dordrecht (2005).
62
S1 P10
NEW TYPES OF CONDUCTIVE LEAD GLASS WITH POTENTIAL APPLICATIONS AS
ELECTRODES FOR BATTERIES
Liviu BOLUNDUŢ, Eugen CULEA, Loredana RUS, Maria Elena PICĂ, Mioara ZAGRAI, Simona RADA
Physics and Chemistry Department, Technical University of Cluj-Napoca, 400020, Romania
This work present new type of conductive lead glasses obtained by melt quenching method, with
potential applications as electrodes for batteries. The samples were analyzed by X-ray diffraction, FT-IR
spectroscopy and cyclic voltammetry.
XRD spectra shows two halos, characteristic to the amorphous structure.
The FT-IR spectra shows that vanadium ions act as network formers, due to the lead atoms inability to
accommodate with excess of oxygen ions. Also the number of [PbO6] units decrease and increase in this way
probably the number of free lead ions (Pb +2) and improving the electrochemical properties of the glass sample.
The cyclic voltammograms shows that all type of obtained glass samples are conductive glasses. From
figure 1 can be observed that the glass doped with antimony, are less conductive (has a smaller value for the
current), perhaps because antimony can form oxygen bridges, and in this way the glass has a low conductivity.
20% V2O5
0.15
current [A]
0.10
0.05
0.00
10% Sb2O3
-0.05
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
potential [V]
Fig. 1. Cyclic voltammograms for the glass samples: 20V2O5∙80[4PbO2∙Pb], 4PbO2∙Pb şi 10Sb2O3∙90[4PbO2∙Pb]
in 38% H2SO4 solution.
The highest conductivity has the samples doped with vanadium. This is due to the fact that the
vanadium forms different structural units with oxygen.
Acknowledgements: This research has been supported by the Project for doctoral studies in UTCN.
The assistance from Technical University of Cluj-Napoca (UTCN) in data collection and for computational work
is gratefully acknowledged.
63
S1 P11
STRUCTURE AND SPECTROSCOPIC PROPERTIES OF THE EUROPIUM-SILVER-LEADGERMANATE GLASSES
Ciprian BULZ1, 2, Eugen CULEA1, 2, Simona RADA1
1
Physics and Chemistry Department, Technical University of Cluj-Napoca, 400020, Romania
2
Babes-Bolyai University, Cluj-Napoca, 400028, Romania
absorbance [u.a.]
The goal of this work is to synthesise by melt-quenching method rare-earth doped glasses with the
xEu2O3∙(100-x){0.10Ag2O∙0.9[GeO2∙PbO]} composition where x=0, 1, 5, 10, 15, 20 and 30%Eu2O3 and to
investigate structural and spectroscopic properties. These glasses are excellent materials for photonic devices
such as optical fiber amplifiers, telecommunications and lasers. The obtained samples were characterized by Xray diffraction and FTIR spectroscopy.
XRD difractograms shows for all samples two
halos, characteristic to the amorphous structure. The FTIR
30%
spectra of the xEu2O3∙(100-x){0.10Ag2O∙0.9[GeO2∙PbO]}
glasses are shown in Fig. 1. The FTIR spectra analysis shows
20%
some modifications of the structural units with increasing of
15%
Eu2O3 content in the host matrix which can be summarized as
10%
follows: i) the intensities of the IR bands situated at about
470, 620 and 990cm-1 were increased; ii) the position of the
5%
band situated at about 405cm-1 was shifted towards smaller
1%
wavenumbers.
-1
At 580cm there is a small band width could be
0%
assigned to the stretching vibration of the Ag-O bond with
400
600
800
1000
increasing Eu2O3 concentration was observed. These
wavenumber [cm ]
structural modifications can be explained considering that the
excess of oxigen ions in the matrix network implies the
rearangements induced by the europium (III) oxide content.
Fig. 1: FTIR spectra of the xEu2O3∙( 00Breaks some of the Pb-O and Ge-O covalent bonds and thus
x){0.10Ag2O∙0.9[GeO2∙ bO]} glasses where
modifying lead-germanate network into europium-silverx=0-30% Eu2O3
lead-germanate structure
-1
64
S1 P12
ELECTROCHEMICAL CHARACTERIZATION AND STRUCTURE OF LEAD-GERMANATE
GLASSES DOPING WITH LI2CO3, MOO3, WO3 AND BI2O3
Mioara ZAGRAI, Elena Maria PICĂ, Eugen CULEA, Liviu BOLUNDUŢ, Loredana RUS, Simona RADA,
Petru PĂŞCUŢĂ
Department of Physics & Chemistry, Technical University of Cluj-Napoca, 400020 Cluj-Napoca, Romania
The recent interest in conductive glasses and related glass-ceramics derivatives comes from their
electrical, mechanical and optical properties which produce to extensive technological applications, especially in
vacuum ultraviolet optics, electronic devices, batteries. Lead-containing glasses formed with different glass
network formers were received attention because of their electrical conduction. The semiconducting properties
of glasses are due to such electron transfer. Moreover, it was early assumed that molybdenum or tungsten oxide
units participate in the glass network itself.
On the other hand, the modifier Pb +2 ions are able to migrate under an applied electric field and are
responsible for electrical conduction in binary PbO-B2O3 glasses which is of ionic nature.
The aim of the present work is to investigate the effect of lithium, molybdenum, tungsten and bismuth
ions on the structural and electrochemical properties of lead-germanate glasses in view of applications as
electrochemical devices. The FTIR and cyclic voltammetry were conducted on these samples to evaluate the
doping effect of structure of the host matrix network. IR data analysis indicated the structural flexibility of the
lead-germanate network due to its incapacity to accommodate with the excess of oxygen atoms and the creation
of bridging oxygen ions.
The envelope of the cyclic voltammograms for glassy samples used as a working electrode in a
electrochemical cell and silver nitrate solution as electrolyte show redox waves corresponding to the lead,
tungsten, molybdenum and silver ions. In case of bismuth and lithium ions, the redox waves were not evidenced
suggesting a slow transfer of electrons.
S1 P13
ELECTRODES BASED ON LEAD GLASSES AND VITROCERAMICS FOR RECHARGEABLE
BATTERIES
Loredana RUS, Eugen CULEA, Tiberiu RUSU, Simona RADA, Mioara ZAGRAI, Nicolae DURA, Marius
RADA1
Department of Physics & Chemistry, Technical University of Cluj-Napoca, 400020, Romania
1
Nat. Inst. For R&D of Isotopic and Molec. Technologies, Cluj-Napoca, 400293, Romania
It is impossible to think of a world without batteries. Rechargeable batteries are now ubiquitous in the
modern world. Lead acid battery is constituted by an anode of metallic Pb, cathode of PbO 2 and a 38% H2SO4
solution used as electrolyte.
Secondary lead produced by recycling process of the lead-acid batteries has become the primary source
of lead in much of the world. Presently, battery manufacturing accounts for greater than 80% of lead
consumption while recycled lead accounts for approximately the same market share of lead supply. These facts
strongly demonstrate the battery manufacturing and recycled lead are intimately coupled in everyday life.
In this work, focus will be on addressing the results obtained on lead glasses and vitroceramics with the
xPb∙(100-x)PbO2 composition, where x=0-50% mole Pb, synthesized by melt-quenching method and the effects
of lead content on host network. This study is a starting step in exploring of a research for how recycled leadacid batteries can become the glass electrods.
The diffractograms of the samples with x = 0 and 40mol% Pb reveal two large halos specific to
amorphous structure. Then, for sample with x=50% Pb, the X-ray diffraction pattern suggests the presence of
metallic lead crystalline phase in the vitroceramic.
FTIR spectra analysis shows that the accommodation of the host network with excess of the lead
content is possible due to the conversion of [PbO6] octahedral units into [PbO3] and [PbO4] structural units.
These structural modifications are supported by the increase in the intensity of the UV-VIS absorption band
associated to electronic transitions of the Pb+2 ions and the formation of non-bridging oxygen centers.
The vitrification method applicable in recycling of the secondary batteries is equivalently in terms of
maturity of production technology, the low cost of production, energy and time saving.
65
S1 P14
NANOCRYSTALLIZATION KINETICS OF Al85Co5Ni5Y5 METALLIC GLASS
BARIS Avar1*, MUSA Gogebakan2
1
Department of Metallurgical and Materials Engineering, Bulent Ecevit University, Zonguldak, Turkey
2
Department of Physics, Kahramanmaras Sutcu Imam University, Kahramanmaras, Turkey
*[email protected]
The Al-rich Al-TM-RE (TM: transition metal; RE: rare earth) metallic glasses have received and still receive
considerable interest because of their unique mechanical properties and capability of the nanocrystallization
during thermal annealing. By annealing, the fcc-Al nanocrystals are embedded in an amorphous matrix, which
resulted in nanocomposite microstructure, leading to remarkable mechanical properties. Therefore, it is
necessary to investigate the crystallization mechanism as well as the microstructural change of the glass-forming
alloys for their technical applications. In the present study, the crystallization kinetics of the glassy Al 85Co5Ni5Y5
melt-spun ribbon were studied by differential scanning calorimetry (DSC) by means of continuous heating and
isothermal annealing, and the products of crystallization were analyzed by X-ray diffraction (XRD) and
transmission electron microscopy (TEM). It was found that the amorphous alloy exhibited a three-stage
crystallization process in the case of continuous heating. The reactions in each stage can be represented as:
Amorphous → Amorphous' + fcc-Al → fcc-Al + Al9Co2 + Al3Y + Al3Ni5. TEM analysis confirmed that the
structure consisted of fcc-Al nanoparticles embedded in an amorphous matrix produced by non-isothermal
annealing of initially fully amorphous ribbons (corresponding to the first exothermic peak). Activation energies
of the crystallization process were determined by Kissinger, Ozawa and Augis-Bennett plots. Isothermal kinetics
was modeled by the Johnson-Mehl-Avrami equation. The Avrami exponents were calculated to be in the range
of 2.5-3 for different isothermal temperatures, which indicated a diffusion-controlled three-dimensional growth.
On the basis of the Arrhenius relation, the activation energy in the isothermal process was calculated to be 450 ±
13 kJ/mol. The Vickers microhardness of the alloys was studied during the crystallization process. The highest
microhardness achieved is 603 ± 21 HV during the first-stage of the crystallization, which related to the presence
of fcc-Al dispersoids in the amorphous matrix.
S1 P15
INVESTIGATION OF STRUCTURAL, THERMAL AND MAGNETIC PROPERTIES OF
NANOCRYSTALLINE Co65W5Ti25B5 POWDERS BY MECHANICAL ALLOYING
BARIS Avar1*, SADAN Ozcan2
1
Department of Metallurgical and Materials Engineering, Bulent Ecevit University, Zonguldak, Turkey
2
SNTG Lab., Physics Engineering Department, Hacettepe University, Ankara, Turkey
*[email protected]
In this work, nanocrystalline Co65W5Ti25B5 (at.%) powders were prepared by mechanical alloying (MA) of the
elemental powder mixture under argon gas atmosphere. The powders were milled during different periods (2.5 h,
5 h, 10 h, 20 h and 30 h) using a planetary ball-mill (Retsch PM100 CM) at 400 rpm. The structural,
morphological, thermal and magnetic properties of nanocrystalline Co 65W5Ti25B5 powders were studied by
means of X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy
(SEM/EDX), differential thermal analysis (DTA) and vibrating sample magnetometer (VSM) techniques.
Because of its high melting point, hardness and low solubility in the alloy components, a small amount of
tungsten remains in the amorphous matrix during milling. By using the Williamson-Hall method, the crystallite
size and lattice strain of the tungsten phase were calculated as 17 ± 5 nm and % 0.37 respectively, after 30 h of
milling. The DTA curves of the milled powders demonstrated an exothermic peak at about 600 °C, indicating the
crystallization of the amorphous phase. The apparent mean activation energy for 10 h milled powders, 290.5 ± 3
kJ/mol was determined by Kissenger and Ozawa methods. The saturation magnetization (Ms) and the coercivity
(Hc) values are of about 66 emu/g, and 9 Oe respectively, after 30 h of milling.
66
S1 P16
MAGNETRON RF SPUTTERING OF INDIUM PHOSPHID FOR TERAHERTZ APPLICATION
L. SIRBU1, A. IONESCU2 A. BARACU3, A. VOICULESCU2
1.
D. Ghitu Institute of Electronic Engineering and Nanotechnologies, 3/3, Academiei str., MD-2028 Chisinau,
Moldova
2. National Institute for Laser, Plasma and Radiation Physics Laboratory of Solid-State Quantum Electronics,
PO Box MG-36, Magurele, 077125, Romania
3. National Institute for R&D in Microtechnologies- IMT Bucharest, Erou Iancu Nicolae 126 A str., Bucharest,
Romania
We developed a combination of technology for deposition contacts/wires upon RF sputtering InP films. In this
way we demonstrate the possibility of fabrication the antennas and detectors. Indium phosphide (InP) films were
deposited onto sapphire substrate using RF magnetron sputtering by varying the substrate temperature (50–
100oC), under constant argon pressure (6.3•10-3 Bar) and RF power (100 W). The absorption coefficient versus
photon energy for InP films were measured at 300 K for three type of thickness, 500, 1000 and 2000 nm,
respectively before and after HNO3 etching. In figure 1 a, b, and c is presented the THz-TDS spectra for three
different thicknesses, and insets represents the amplitude of THz pulse for etched vs initial samples.
According to the early report of Aspnes and Studna [1983] the thickness of InP films was optimized in order to
obtain a high absorption coefficient (α) [1]. As it can be seen in figure 1. d, the slope of the absorption coefficient
vs wavelength is changed after indium layer etching wich remained after RF deposition. THz-TDS spectra are
obtained using a system based on a self mode locked Ti-Sapphire oscillator (FEMTOLASERS) which emits
pulses of 19fs pulse width at a wavelength of 808nm and an average output power of 160mW. We report a
surface impedance for the magnetron RF sputtering InP films of ~0.57 MΩ compared with 0.6 MΩ for LT-GaAs
(PCA 40-05-10-800-x from BATOP Optoelectronics) [2].
a)
b)
c)
d)
Fig. 1. Time-dependent THz field strength after transmission of the THz pulses through InP films of different
thicknesses a) 500nm b), 1000nm c), 2000nm before (blue) and after etching (red) and d) IR spectra for InP films
of 500 and 1000 nm thickness before and after HNO3 etching (inset is represented a butterfly antenna with gap
inter-distance of 5 μm).
1. Aspnes, D. E. and A. A. Studna, Phys. Rev. B27, 2 (1983) 985-1009
2. www.batop.com/products/terahertz/photoconductive-antenna/data-sheet/manual_PCA-40-05-10-800.pdf
67
S1 P17
FUNCTIONAL PROPERTIES OF GRAPHITE-DERIVED POROUS BaSrTiO3 CERAMICS
R. STANCULESCU1, C. E. CIOMAGA1, C. GALASSI2, L. MITOSERIU1,
1
Faculty of Physics, Alexandru Ioan Cuza University, Iasi, Romania
2
ISTEC-CNR, Via Granarolo, no.64, I - 48018, Faenza, Italy
Corresponding Author: [email protected]
Porous Ba0.70Sr0.30TiO3 (BST) ferroelectric ceramics are promising substitutes for their dense
homologous in order to maintain a high dielectric tunability while the dielectric constant is decreasing, to avoid
the dielectric breakdowns as well as to keep a low dielectric loss tangent. From the viewpoint of practical
applications, these are critical parameters for tunable devices.
The aim of this study was to prepare dense and graphite – derived porous BST ceramics with different
degrees of porosity and to discuss the role of porosity on its functional properties.
The powders with Ba0.70Sr0.30TiO3 composition were prepared following the mixed oxide method by
solid-state reaction, calcinated at a temperature of 950oC for 4 h and sintered at 1450°C for 2h in order to obtain
pure phase in the final bulk ceramic. BST ceramic samples with various porosities have been obtain by using
graphite in concentration of 10, 20 and 35 vol% as sacrificial template in the BST powder. The sintering process
at 1450°C/2h allow to the graphite phase to burn out inducing changes in the morphology, microstructure as
well as the density, shape and size of pores in the ceramic product. The purity phase of these samples was
checked by XRD analysis and the microstructures was observed using Scanning Electron Microscopy (SEM). A
fracture mode transformation from intragranular to an intergranular fracture has been observed. Modifications of
the grain size and of the grain boundaries volume were also observed and discussed.
The prepared ceramics were investigated using Impedance Spectroscopy method in the temperature
range of (21-200)°C and frequency of 20Hz–2MHz. From dielectric investigations, it was observed that the
dielectric permittivity of the BST ceramics with different degree of porosity presents a decrease with increasing
the porosity, from ' 7500 (for dense BST ceramic) down to ' 250 (for the BST with 35vol% graphite
addition). The temperature dependence of permittivity revealed that the phase transition from ferroelectric to
paraelectric state with a Curie temperature close to the room temperature (around 30 oC) for all the investigated
ceramics was obtained. A complex dielectric relaxation response was obtain by investigation dielectric
properties vs. frequency for different temperature and the thermally activated mechanism with the activation
energies were determined. The effect of addition of lamellar graphite as pore forming agent on the dielectric
response at low and high electric field was investigated and discussed.
Acknowledgements: This work was financially supported by CNCS-UEFISCDI project PNII-RU-TE-20123-0150 and by the strategic grant POSDRU/159/1.5/S/137750, roject “Doctoral and Postdoctoral programs
support for increased competitiveness in Exact Sciences research” cofinanced by the European Social Found
within the Sectorial Operational Program Human Resources Development 2007 – 2013.
68
S1 P18
IMPEDANCE SPECTROSCOPY OF SOME MANGANESE FERRITE POWDERS
I. MALAESCU1, A. LUNGU1, C. N. MARIN1, P. VLAZAN2, P. SFARLOAGA2
1
West University of Timisoara, Faculty of Physics, Bd.V. Parvan,No. 4, 300223 Timisoara, Romania,
2
National Institute for Research and Development in Electrochemistry and Condensed Matter, 300569
Timisoara, Romania
Two powder samples of manganese ferrite denoted by S1 and S2, have been synthesized by different
methods. For all samples the raw materials were MnCl2ˑ4H2O and FeCl3ˑ6H2O. The sample S1 has been
synthesized by calcination at 700 ˚C and sample S2 has been obtained by hydrothermal method. The crystalline
phase of samples is ABO3 perovskite type (for sample A) and AB 2O4 spinel type (for sample B), which were
confirmed using X-ray diffraction (XRD). The grain morphologies were analyzed by scanning electron
microscopy (SEM) and the compositional analysis was done by energy dispersive spectroscopy (EDAX).
The frequency ( f  / 2 ) and temperature ( T ) dependencies of the complex impedance,
Z ( f ,T )  R( f ,T ) iX ( f ,T ) , over the ranges 200 Hz to 2 MHz and 250C to 950C, for investigated manganese
ferrite samples, are presented. The experimental complex-plane impedance spectrum for samples is a semicircle
(figure 1) and show that the impedance has a capacitive character between the resonance frequency, f0 (which
decreases by increasing temperature) and frequency of 2 MHz (fig. 1).
0
(1) - T = 30 C
0
(2) - T = 50 C
0
(3) - T = 70 C
0
(4) - T = 92 C
25
20
15
2
10
5
0
2 MHz
0
5
1
3
4
T
f01=670 Hz
- Im Z [ k]
30
f04=4141 Hz
10
15 20
Re Z [ k]
25
30
Figure 1. Impedance Cole-Cole plot of the sample S1 at various temperatures
In this work, the impedance spectroscopy for investigating of the samples is presented. For this an
equivalent electric circuit for testing the method was designed, the complex impedance was determined and the
obtained data were used to compute the constitutive elements (R,C) of the circuit on the bases of the Cole-Cole
plot.
Keywords: manganese ferrite, complex impedance, Cole-Cole plot.
References
[1] Khalid Mujasam Batoo, Study of dielectric and impedance properties of Mn ferrites, Physica B, 406 (2011)
382–387
[2] E. Barsoukov et al., Impedance Spectroscopy Theory, Experiment & Applications, Wiley Interscience (2005)
[3] M. Azizar Rahman, A. K. M. Akther Hossain, Electrical transport properties of Mn-Ni-Zn ferrite using
complex impedance spectroscopy, Phis. Scripta, 89-2 (2014) 025803
69
S1 P19
SYNTHESIS AND CHARACTERIZATION OF MANGANESE FERRITES NANOPOWDERS
Vasilica GAFTON1, Ioan DUMITRU1, Valentin NICA1, Ovidiu F CALTUN1, Adrian BORHAN2, Andrei
DIACONU2, Irina V VARARU2, , Alexandra R IORDAN2, Mircea N PALAMARU2
1
Faculty of Physics, Alexandru Ioan Cuza University from Iasi, Romania
Faculty of Chemistry, Alexandru Ioan Cuza University from Iasi, Romania
2
Polycrystalline oxides with spinel structure, with general formula AIIBIII2O4, have drawn attention of
researchers because of various applications. If B III = Fe3+, compounds obtained are called ferrites, and these
materials have magnetic applications [1, 2].
Our main objective was to synthesize pure nanocrystalline manganese ferrite powders by sol-gel autocombustion method and to investigate the influence of chelating/combustion agents on the structural features and
magnetic properties by using, for the first time, five different chelating/combustion agents. As is known, the
effectiveness of materials depends on micro-structural properties that are sensitive to preparation method. Hence,
sol-gel auto-combustion method offers specific advantages in preparations of multi-component oxide materials,
such as: stoichiometric control of simple reactants, reduced synthesis time, good chemical homogeneity and
obtaining nanoparticles. Our interest in producing and characterization of this type of compounds is given by the
observation that Mn2+ and Fe2+ metallic ions exhibit a good contrast for investigations on spin-lattice relaxation
time in MRI technique due to their high magnetic moments [3, 4].
Nanoparticles of MnFe2O4 ferrite were prepared by sol-gel auto-combustion method. Fuel agents were
added to each sample of metal nitrates mixture in 1:1 molar ratio of fuel agent to metallic cations. After
corresponding salts solubilisation and fuel agents addition, the solutions were heated at 75ºC through gel phase
transformation. The gel was gradually heated at 300ºC, when the autocombustion occurred. The obtained
powders were subjected to heat treatment.
The structure was investigated by X-ray diffraction technique. The broad XRD lines indicate that ferrite
particles are in the nano-size scale. Magnetizations (M) versus magnetic field (H) curves were measured at room
temperature.
In the present work we successfully synthesized manganese ferrites nanopowders by a sol-gel method
using several compounds as fuel. The magnetic properties measurements demonstrate an increase of the
saturation magnetization with the type of combustion agents as a consequence of the structure features.
References
[1]T.K. Pathak, N.H. Vasoya, V.K. Lakhani, K.B. Modi, Ceram. Int. 36, 275 (2010).
[2] C. Barcena, A. K. Sra, G. S. Chaubey, C. Khemtong, J. P. Liu, J. Gao, Chem. Comm., 2224 (2008).
[3] A. Doaga, A. M. Cojocariu, C. P. Constantin, R. Hempelmann, O. F. Calțun, AIP Conf Proc 1564 , 123
(2013)
[4] A. Doagă, A.M. Cojocariu, W. Amin, F. Heib, R. Hempelmann, O.F. Călțun, Mat Chem Phys 143 (1) , 305
(2013)
70
S1 P20
STRUCTURAL PROPERTIES OF Sm-Co THIN FILMS
I. STANCIU, A. TAKACS, S. MICAN, D. BENEA AND V. POP
In this study we investigated the formation of the SmCo5 phase in thin films deposited on a Si substrate.
Obtaining the SmCo5 phase was of particular interest because of its high anisotropy which is critical to the
production of exchange-coupled SmCo5/Fe65Co35/SmCo5 multilayers.
Thin films were deposited in the Cr(150nm)/Sm-Co(30nm)/Cr(5nm) configuration by DC magnetron
sputtering from a SmCo5 target onto Si(100) substrates with a 100 nm SiO 2 layer. The substrates were buffered
by a Cr layer in order to maintain the in-plane anisotropy of SmCo5. A lattice mismatch of 3.3% between the
Cr(110) buffer and the SmCo5 c axis plane was calculated. Several samples were deposited at different substrate
temperatures and later subjected to ex-situ heat treatments under vacuum for one hour at 600 °C. The effects of
substrate temperature on the films’ crystallinity were investigated.
Structural analysis was performed by X-Ray Diffraction. The as-deposited Sm-Co samples appear to be
amorphous – Figure 1a, while the heat treated films exhibit SmCo5 (111) and (110) characteristic peaks – Figure
1b. Increasing peak intensities of the SmCo5 phase are correlated with the increase in substrate temperature
during deposition. The enhanced (110) peak is indicative of the in-plane preferential orientation of the c axis.
Figure 1 – XRD patterns of the as deposited (a) and heat treated (b) Cr(150nm)/SmCo(30nm)/Cr(5nm) films.
a
b
Acknowledgment This work was supported by the Romanian Ministry of Education and Research, Grant PN-II
RU-TE-2011-3-0048.
71
S1 P21
STRUCTURAL AND ANTIBACTERIAL PROPERTIES OF Ni DOPED ZNO NANOPOWDERS
EDA ÇİNAR AVAR1, BARIŞ AVAR2, ELIF LOĞOĞLU1
1
Department of Chemistry, Faculty of Sciences, Gazi University, Teknikokullar, 06500, Ankara, Turkey
2
Department of Metallurgy and Materials Engineering, Bülent Ecevit Universit , 7 00,
Zonguldak, Turkey, *[email protected]
Due to the microbial contamination is a serious issue in healthcare and food industry, the development of
antibacterial agents and surface coatings has been attracting increasing attention in recent years. Transition metal
oxide doped zinc oxide (ZnO) nanoparticles exhibit strong antibacterial activities against a broad spectrum of
bacteria though its antibacterial mechanism is still under investigation. In this study, Ni doped ZnO nanopowders
were synthesized using high-energy ball milling process. The milling process was performed at 450 rpm milling
speed for different milling durations. Structural and morphological properties of the powders during ball milling
were investigated by means of X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive
X-ray spectroscopy (SEM/EDX) and transmission electron microscopy (TEM). However, these samples were
tested for antimicrobial activity aganist gram-positive bacteria such as Bacillus licheniformis M30, Bacillus
cereus B9, Staphylococcus aureus ATCC 6538, Micrococcus luteus M3; gram negative as Escherichia coli
ATCC 25922, Pseudomonas aeruginosa P7. The antibacterial activities were determined by the disc-diffusion
method and minimum inhibition concentration (MIC) against gram-positive and gram-negative bacteria. All the
bacterial strains were studied against to antibiotics like chloramphenicol, tetracycline, ampicilline, gentamicin,
ketoconazole, and penicillin to compare with our chemicals zone diameters.
S1 P22
POROUS COPPER MINI-PLATES – A POSSIBLE CANDIDATE FOR GDL IN PEM FUEL CELLS
Cristina Mihaela SIMA1, Victor CIUPINA2, Gabriel PRODAN2
¹Department of Solid-State Physics, University of Bucharest, Buchaest-Magurele 077125, Romania
² Ovidius Universit of Constanta, Constanta 900527, Romania
The performance of a Proton Exchange Membrane Fuel Cell (PEMFC) is strongly influenced by the
material of the gas diffusion layer (GDL). In general, a GDL is made of a carbon black mixed with Teflon
micro-porous layer applied onto macro-porous carbon fiber substrate. This paper comes with the novelty that
instead of the carbon based GDL we introduced a porous copper GDL. The copper mini-plates were sintered in
Ar-H2 gas mixture. Different amounts of naphthalene were mixed with copper filings in order to obtain the
porous mini-plates. The results showed that after sintering, there were no more amounts of naphthalene, fact
proved by the pore appearance in their place, in the sintered copper filings. Tests have highlighted that the
porous copper mini-plates provide gas access from the flow-field channels to the catalyst layer, which is one of
the main goals of the GDL.
Keywords: PEM fuel cell, GDL, carbon black, catalyst layer
72
S1 P23
CONTRIBUTIONS IN THE OPTIMIZATION OF THE ELECTRON DIFFRACTION PRECESSION
SYSTEM FOR THE EXAMINATION OF THIN FILMS
V. CIUPINĂ1,2,3,4, G. PRODAN2, R. MANU3, Ş.G. TUTUN3, L. PETRĂŞESCU3,
N. VINETICU3, O. BRÎNCOVEANU3 , I. PRIOTEASA3.
1
Department of h sics, Facult of pplied Sciences and Engineering, Ovidius Universit , Constanţa, Romania
2
Institute for Nanotechnolog and lternative Energ Sources, Ovidius Universit , Constanţa, , Romania
3
Faculty of Physics, University of Bucharest, tomiştilor 405, Măgurele, Ilfov
4
Nanostructured materials are accurately investigate using TEM (transmission electron microscopy), but
compromise must be taken when information are acquired using electron diffraction technique. Due to
instrument geometries, the errors in electron diffraction data will be larger compared with X-Ray diffraction, and
difficult to analyze. In 1994, Vincent and Midgley was start development a new technique for electron
diffraction, that improve quality of electron diffraction pattern and data extracted from there. The new technique
are based on simple precession device, that are apply to electron beam before interaction with sample and final
image are refocused by microscope lens. The advantages of new techniques are evident, and we can note that are
compatible with old type of electron microscope, eliminate the dynamic effects, and very easy to setup.
All diffraction patterns include data that must be interpreted with precaution. Comparative with other techniques
(XRD, neutron diffraction), electron diffraction are very sensitive to background noise. Advantage of using
electron diffraction is small area taken in study, until few nanometers square, but sample can be complex and
affects results. For amorphous samples, we cannot separate useful data because of additional quantity given by
scattering on amorphous carbon or formvar film substrate, for example. Crystalline structure analysis can be
done in two-step: first, crystallographic information and cell parameters determination and second, refinement of
the unit cell, including atom position.
Concerning the crystalline structure data extracted from electron diffraction pattern can be improved by means of
statistical method. Cohen method, applied to XRD data with model implemented to cover instrumental behavior
are a good example. We applied Cohen method with a model implemented by Nielson-Riley adapted for electron
diffraction by simple trigonometric approximation valid in electron diffraction case (sinθ=0, cosθ=1).
73
S1 P24
LOOKING FOR IN BASED ACTIVE LAYER INTERFACE ON CLEAVED GAAS(100) SURFACE
C.C.NEGRILA, R.V.GHITA, C.LOGOFATU, C.COTIRLAN, F.FRUMOSU, M.F.LAZARESCU
National Institute of Materials Physics, P.O.Box MG-7, Magurele, Bucharest, ROMANIA,
E-mail:[email protected]
An alloying method is widely used to fabricate an ohmic contact to III-V compounds, where metal films are
deposited on semiconductor surface and are alloyed with the substrate forming a degenerate semiconductor layer
beneath the contact [1]. Semi-insulating GaAs is a potential candidate for electronic devices as Schottky diodes
and in this view the technological problems to be overcome are Schottky barriers and ohmic contacts deposition.
This work presented an extended study on In-based thin film deposited on a cleaved GaAs(SI) (100) surface with
the purpose of obtaining a good ohmic contact( contact resistivity~10 -5Ωcm2), for a special Schottky device
obtained in a dedicated cleaved geometry. The InGe film of 30 nm was deposited on a in situ vacuum cleaved
GaAs(100) surface, the active surface being obtained with a home-made device. There are expected isolated
islands of graded InxGa1-xAs heterojunction formed during annealing [2, 3]. The In/GaAs interface and Ge role
was investigated by XPS measurements and an experimental depth profiling was provided by ion etching (Ar ion
beam of 3 keV, beam current: 10μA, etching time: 6 minutes) as can be seen in picture:
The XPS analysis and the depth profiling obtained in a XPS-SPECS machine, indicated at In line (17.1 eV) the
compound InxGa1-xAs, at As line the presence of oxide, and at Ge line, the presence Ge metallic state acting as a
doping element in semiconductor layer. The experimental InGe contact on GaAs(SI) conduced to a measured
Rs~ 200Ω with a linear I-V characteristics.
[1] M.Ogawa, J.Appl. Phys. 51(1), pp.406, (1980)
[2] A.A.Lakhani, J.Appl.Phys. 56 (6), pp.1888, (1984)
[3] M.Murakami, Science and Technology of Advanced Materials, (3),pp1, (2002)
74
S1 P25
EFFECT OF Li, Cu AND N DOPING ON THE MORPHOLOGY, OPTICAL AND ELECTRICAL
PROPERTIES OF ZnO THIN FILMS PREPARED BY SPIN-COATING TECHNIQUE
A. DANCIU, I. MIHALACHE, B. BITA, R. PLUGARU*
National Institute for Research and Development in Microtechnologies-IMT Bucharest, Romania
* corresponding author: [email protected]
The effect of Li, Cu or N elements on the morphology, optical and electrical conduction properties of ZnO
thin films has been studied for dopant concentrations in the range 1-5 wt.%. The films were deposited on p-type
Si(100)/SiO2 and glass substrates by sol-gel, spin-coating technique. A pre-heating treatment at 130 °C for 5 min
was performed after each deposition and the multilayered films were annealed in a furnace at 500 °C in air
atmosphere, for 1 h. Scanning Electron Microscopy investigation revealed that the surface morphology and
porosity of the films are affected by the dopant type and doping concentration. Thus, Li:ZnO and N:ZnO films
show rippled surfaces, while Cu:ZnO films surfaces appear smooth. The roughness decreases with increasing
doping concentration. All the films present a good transparency with the transmittance in the visible region in the
range of 80-83 % for Li:ZnO, 87-89 % for Cu:ZnO and 76-83 % for the N:ZnO films. The band gap energy
calculated from the absorbance measurements varies from 3.21 eV in the case of undoped ZnO films to 3.22 eV
for 5 wt.% Li:ZnO films, to 3.16 eV for Cu:ZnO films and increases to 3.24 eV for N:ZnO films. The blue shift
of optical band gap observed in the case of Li and particularly N doping is attributed to the Burstein–Moss effect
and suggests that these impurities are incorporated in the host matrix by creating shallow donor centers which
challenge the formation of acceptor centers [1]. The optical band gap red shift which appears in the Cu doped
films evidences that deep localized defect states are induced by Cu and can act as charge carriers traps [2]. The IV characteristics of the films were measured in the dark and under the light conditions. The highest conductivity
has been obtained in the case of 1 wt.% Li:ZnO films and 5 wt.% N:ZnO films. The optical and electrical
ZnO
Li: ZnO
Cu:
ZnO
properties of the films are discussed in relationship with the doping process parameters.
Acknowledgements
This research was supported by STAR program, Project no. 94 MATSPACE, funded by the Romanian Space
Agency ROSA.
[1] A. Janotti, C. G.Van de Walle, Rep. Prog. Phys. 72 (2009) 126501.
[2] M. Caglar, F. Yakuphanoglu, Appl. Surf. Sci. 258 (2012) 3039-3044.
75
S1 P26
ZNO-BASED STRUCTURES: FROM POWDERS TO HIGH QUALITY THIN FILMS
L.M. TRINCA1,2, A.C. GALCA1, C. CHIRILA1, C. BESLEAGA1, L. PINTILIE1
1
2
National Institute of Materials Physics, 105 bis Atomistilor Str., 077125 Magurele, Ilfov, Romania
University of Bucharest, Faculty of Physics, 405 Atomistilor Street, PO Box MG-11, 077125, Magurele-Ilfov,
Romania, Contact author: [email protected]
Transparent oxide electronics is a hot topic nowadays, being of great interest for worldwide technology
development. Zinc oxide (ZnO) is attractive for electronic applications due to a wide range of electrical
properties while doping with different impurities, also being transparent in the visible spectrum. Despite of the
great amount of studies on zinc oxide nanostructures, there are only a few which refer to ZnO integrated in
devices[1,2].
In this work is presented the technological process of achieving ZnO-based multilayer structures,
starting with distinct oxide powders, continuing with target preparation and ending with pulsed laser deposition
of thin films. Looking forward to a ferroelectric field effect transistor, each thin film has been characterized and
the processing was optimized in order to get the best functionality.
Aluminium doped ZnO (AZO) which is known to be a good alternative to expensive ITO [3], is used as
transparent electrode. For dielectric/ferroelectric layer is considered Lithium doped ZnO (LZO) [4]. The 3-layer
structures (Li:ZnO/Al:ZnO/ZnO and Li:ZnO/Pt/Si) were processed and characterized by means of structural,
optical and electrical properties.
There will be presented a comparative study on the structural and electrical properties of non-perovskite
Li:ZnO thin films deposited on Platinum and on a transparent conductive oxide, highlighting if the C-V
hysteresis is of ferroelectric nature or not.
[1] H. Ohta, M. Orita, M. Hirano, J. Appl. Phys. 89, 5720 (2001)
[2] A. P.Ramirez, Science 315, 1377 (2007)
[3] J. G. Lu, Z. Z. Ye, Y. J. Zeng, L. P. Zhu, L. Wang, J. Yuan, B. H. Zhao, Q. L. Liang, J. Appl. Phys. 100,
073714 (2006)
[4] Dhananjay, J. Nagaraju, S. B. Krupanidhi, J. Appl. Phys. 101, 104104 (2007)
S1 P27
THE ROLE OF Sc IONS ON THE MAGNETIC AND CATALYTIC PROPERTIES OF Co- Ni
NANOFERRITE
C. DOROFTEI1,2, P.D. POPA1, E. REZLESCU1, N. REZLESCU1
1
Institute of Technical Physics, 47 D. Mangeron Blvd, 700050 Iasi, Romania.
“ l. I. Cu a” Universit , Facult of h sics,
Carol I Blvd, 700050 Iasi, Romania.
In the last years, besides the magnetic properties of spinel ferrite, their catalytic properties in the flameless
combustion of volatile organic compounds have also been investigated [1]. The magnetic and catalytic properties
of the spinel ferrites are influenced by the distribution and nature of cations among the octahedral and tetrahedral
sites in the spinel structure [2,3].
2
In this work the Sc3+ doped Ni-Co ferrites was synthesized by self-combustion method. The properties of these
ferrites have not been investigated until now. The magnetic properties of the nanocrystalline Ni 0.5Co0.5ScxFe2-xO4
and its catalytic activity in the combustion reaction were studied. The catalytic activity of some air diluted
VOC’s in the combustion reaction improves with the increase of Sc3+ content. The magnetic properties of these
ferrites diminish with the increase of Sc3+ ion content as the result of the decrease of Fe3+ ion content in the
lattice.
Acknowledgements: This work was performed by financial support of the Project PN-II-ID-PCE-2011-3-0453,
CNST-UEFISCDI.
References
[1] D. Hirabayashi, T. Yosikawa, Y. Kawamoto, K. Mockizuki, K. Sukuki, Adv. Sci. Tech. 45, (2006), 2169.
[2] J. Smit, H.P.J. Wijn, Les Ferrites, Dunod, Paris, 1961.
[3] J. Baijal, S. Phanjouban, C. Prakash, I. Kishan, J. Sol. Stat. Com. 82 (1993) 679681.
76
S1 P28
NEW PROSPECTS FOR PERMEABLE THERMOELEMENTS APPLICATION
Radion CHERKEZ
Chernivtsi, Ukraine
…………………….
S1 P29
THERMALLY TREATED CuCoFe THIN FILMS OBTAINED BY TVA METHOD
V.CIUPINĂ,1,4, I.PRIOTEASA2, Ş.G.TUTUN2, L.PETRĂŞESCU2, C.P. POROSNICU3 , I.MUSTATA3 ,
C.P.LUNGU3 , E.VASILE5 , G.SCHINTEIE6
1
Department of Plasma, Faculty of Applied Sciences and Engineering,Ovidius Universit , Constanţa, Romania
2
Faculty of Physics, University of Bucharest, tomiştilor 405, Măgurele, Ilfov
3
National Institute for Laser, Plasma and Radiation Physics, Bucharest, Romania
4
5
6
National Institute for Material Physics, Magurele, Romania
CuCoFe thin films were deposited by Thermionic Vacuum Arc(TVA) method on glass and Si substrate. The
deposition was a multilayer one, each layer having a thickness of 10 nm. The first layer was of Cu, then one
layer of Co, one of Cu and last one of Fe; this order repeated itself until it reached the thickness of 160 nm (16
layers). After the deposition, a part of the samples were thermally treated for an hour at the temperature
of 4000C. In the case of thermally non-treated films, the scanning electron microscopy (SEM) analysis reveals
the presence of grains with sizes of 16-20 nm. In the case of thermally treated structures the grains size is
about 40-45 nm. The magneto resistance of the films was measured at different temperatures.
Keywords: Thermionic Vacuum Arc, Scanning Electron Microscopy, magneto-resistance
77
S1 P30
CARBON – PLATINUM NANOSTRUCTURED CATALYSTS FOR HYDROGEN FUEL CELLS
V.CIUPINĂ1,2,5, R.VLĂDOIU1, G.PRODAN1,2, L.PETRĂŞESCU3, Ş.G.TUTUN3, C.P. POROŞNICU4 ,
E.VASILE6, I.PRIOTEASA3, R. MANU3
1
Department of Plasma, Faculty of Applied Sciences and Engineering,Ovidius Universit , Constanţa, Romania
2
Institute for Nanotechnolog and lternative Energ Sources, Ovidius Universit , , Constanţa, Romania
3
Facult of h sics, Universit of Bucharest, tomiştilor 405, Măgurele, Ilfov
4
National Institute for Laser, Plasma and Radiation Physics, Bucharest, Romania
5
6
As the necessity for energy keeps on growing it has become a pressing concern the development of new methods
of producing energy both efficient and harmless for our environment. In the past the limiting factors of
renewable energy were the storage and transport of that energy. By using fuel cells and hydrogen based
technology the electrical energy from renewable sources can be distributed where and when is needed, clean,
efficient and sustainable. Nanotechnology is the area of interest in the research of new methods of improving the
performance and reducing the costs of the catalysts used in fuel cells.
In order to prepare nanostructured carbon based films (C – Glass + Pt) for use in the anode and cathode parts of
fuel cells, the method of thermionic vacuum arc (TVA) was used in one electronic gun configuration. One of the
main advantages of this technology is the bombardment of the growing thin film just by the ions of the
depositing film. Moreover, the energy of ions can be controlled. Thermo-electrons emitted by an externally
heated cathode and focused by a Wehnelt focusing cylinder are accelerated towards the anode whose material is
evaporated and bright plasma is ignited by a high voltage DC supply.
The nanostructured C – Glass + Pt films were characterized by Transmission Electron Microscopy (TEM) and
magnetoresistance analysis. In the presence of a magnetic field of 0.3 T all the films that were investigated
showed a slight drop in resistance.
The TEM analysis revealed that both films have a uniform morphology and amorphous structure.
Keywords: C – Glass + Pt, TEM, TVA, magnetoresistance, fuel cells
78
S1 P31
APPLICATION OF SOME CARBON-ALUMINIUM BASED NANOSTRUCTURES IN DIVERTORS
COATING FROM FUSION REACTOR
V.CIUPINĂ1,2,5, R.VLĂDOIU1, G.PRODAN1,2, Ş.G.TUTUN3 , L.PETRĂŞESCU3, C.P. POROŞNICU4 ,
E.VASILE6, I. PRIOTEASA3, R. MANU3
1
Department of Plasma, Faculty of Physics, Chemistry, Electronics and Oil Technology,
Ovidius Universit , Mamaia 24, Constanţa, 900527, Romania
2
Institute for Nanotechnology and Alternative Energy Sources, Ovidius University,
Mamaia 24, Constanţa, 900527, Romania
3
Facult of h sics, Universit of Bucharest, tomiştilor 405, Măgurele, Ilfov
4
National Institute for Laser, Plasma and Radiation Physics, PO Box MG-36, 077125, Bucharest, Romania
5
6
Nanostrctured carbon materials have increasingly attracted the interest of the scientific community, because of
their fascinating physical properties and potential application in high-tech devices. In the current ITER
(International Thermonuclear Experimantal Reactor) design, the tiles made of carbon fiber composites (CFCs)
are forseen for the strike point zone and tungsten (W) for other parts of the divertor region. This choice is a
compromise based mainly on experience with individual materials in many different tokamaks. Also C-Al
composites are the candidate material for this first Wall in ITER.
In order to prepare nanostructured carbon based nanocomposite for the divertor part in fusion application, the
method thermionic vaccum arc (TVA) was used in two electronic gun configuration. One of the main advantages
of this technology is the bombardment of the growing thin film just by the ions of the depositing film. Moreover,
the energy of ions can be controlled. Thermo-electrons emitted by an externally heated cathode and focused by a
Wehnelt focusing cylinder are strongly accelerated towards the anode whose material is evaporated and bright
plasma is ignited by a high voltage DC supply.
The nanostructured amorphous C-Al samples were characterized by Transmission Electron Microscopy (TEM)
and with a magneto-resistance coil device. The carbon based nanostructures were identified by TEM as having
an uniform morphology and amorphous structure. In the presence of a magnetic field of 0.3T all the thin films
that were investigated showed a slight drop in resistence.
S1 P32
CAVITY RING-DOWN SPECTROSCOPY MEASUREMENTS ON HYDROXYAPATITE THIN
FILMS
Costel COTIRLAN-SIMIONIUC, Rodica V. GHITA, Daniela PREDOI, Cristina L. POPA
National Institute for Materials Physics, 105 Bis Atomistilor Street, P.O. Box MG-7, 077125, BucharestMagurele, Romania
Coatings of hydroxyapatite are often applied to metallic implants to alter the surface properties so the
body accepts the implant like bone-type material. On the other hand like bone filler the hydroxyapatite will
provide a scaffold and encourages the rapid filling of the void by naturally forming bone and provides an
alternative to bone grafts. It will also become part of the bone structure and will reduce healing times compared
to the situation, if no bone filler was used.
Despite their increasing importance in scientific and technological research nowadays, this kind of
material has not been enough studied. In the present work we will report about the results of cavity ring-down
spectroscopy measurements for optical absorption correlated to the crystallinity of hydroxyapatite thin films
obtained by thermal vacuum deposition (TVD) on quartz substrate. The crystalline coatings are observed to be
more adherent to substrate. The crystals grown in granular morphology are generally resisting delamination than
the columnar morphology. The transition from amorphous phase to crystalline phase can occur at 340 oC (Koch
et al 2007). The hydrothermal treatment subsequent to TVD can further reduce the temperature of the
amorphous-to-crystalline transition of hydroxyapatite.
79
S1 P33
ASSESMENT OF THE STRUCTURAL, MORPHOLOGICAL AND PHOTOCATALYTIC
PROPERTIES OF TiO2-Ag BASED POROUS NANOARHITECTURES
G. KOVÁCS,1,2 V. DANCIU,1 ZS. PAP,1,2 L. BAIA,2,3 V. COȘOVEANU,1 A. VULPOI,2,3 T. RADU,2,3 K.
MAGYARI,2,3 C. GRUIAN,2,3 and M. BAIA2,3
1
Facult of Chemistr and Chemical Engineering, Babeş-Bolyai University, Cluj-Napoca, Romania,
2
Facult of h sics, Babeş-Bol ai Universit , M. Kogălniceanu ,400084 Cluj-Napoca, Romania.
3
Institute for Interdisciplinary Research in Bio-Nano-Sciences, Babes-Bolyai University, Cluj-Napoca, Romania
The destroying of chemical pollutants from water by photocatalysis is a rather complex issue because
the improvement of the photocatalytic activity of the employed materials strongly depends on several factors like
specific surface area, crystalline structure, crystallites size, time of recombination of the electron-hole
photogenerated pairs, etc.
Titania is a well-known semiconductor with a band gap energy that permits UV light absorption and
possesses a high oxidation power. In the last decades it was extensively employed in photocatalytic applications.
Titania based aerogels are porous solid architectures with high surface area and a continuous mesoporous
network formed from interconnected nano-quasicrystallites building blocks [1]. However, an important
drawback of TiO2 is that it absorbs only UV light that represents less than 8% of the solar spectrum. Any shift in
its optical response from the UV to visible spectral range could lead to a further increase of the photocatalytic
performance. Therefore, the obtaining of novel porous TiO 2 based materials and the understanding of the
morphological and structural particularities with the purpose of improving their photocatalytic activity still
remains an imperative challenge. In this respect, it has been reported that the addition of transition metals to
TiO2 can increase its photocatalytic activity by decreasing the energy band gap or preventing electron-hole pair
recombination [1].
Having in mind the above mentioned aspects, in the present work, the interest was focused on the
obtaining of silver doped TiO2 porous materials and evaluating their structural and morphological properties
from the perspective of improving their photocatalytic performances. Besides the photocatalytic activity
assessment, several complementary techniques like nitrogen sorption, transmission electron microscopy in high
resolution mode, X-ray photoelectron spectroscopy, and diffuse reflectance UV-vis spectroscopy were used to
evidence the influence of the silver amount on the TiO2 porous structures. Correlations between the structural
and morphological data obtained from the performed investigations and the acquired apparent photodegradation
rates were also performed.
Acknowledgments: This work was supported by the grants of the Romanian National Authority for Scientific
Research MNT ERA_NET nr.7-065/26.09.2012 and PN-II-ID-PCE-2011-3-0442.
Reference
1. M. Baia, Zs. Pap, V. Danciu, and L. Baia, Chapter 7: Towards improving the functionalities of porous TiO2Au/Ag based materials, in “Advanced Sensor and Detection Materials” (Eds. A. Tiwari and M. Demir), ISBN:
978-1-118-77348-2, WILEY-Scrivener Publishing, 189-223, 2014.
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POROUS TiO2- SiO2 BASED MATERIALS: STRUCTURAL, MORPHOLOGICAL AND
PHOTOCATALYTIC PROPERTIES
G. KOVÁCS,1,2 V. DANCIU,1 ZS. PAP,1,2 M. BAIA,2,3 V. COȘOVEANU,1 A. VULPOI,2,3 T. RADU,2,3 K.
MAGYARI,2,3 C. GRUIAN,2,3 and L. BAIA2,3
1
Facult of Chemistr and Chemical Engineering, Babeş-Bolyai University, Cluj-Napoca, Romania,
2
Facult of h sics, Babeş-Bolyai University, Cluj-Napoca, Romania.
3
Institute for Interdisciplinary Research in Bio-Nano-Sciences, Babes-Bolyai University,Cluj-Napoca, Romania
The scientific interest for TiO2-SiO2 based materials has been lately increased due to their applicability
in photocatalysis, their high chemical stability and non-toxicity [1]. The presence of SiO2, besides of TiO2, was
found to constrain the increase of the titania particles size [1]. Furthermore, silica increases the specific surface
area and porosity of the composite matrix. On the other hand, ones of the most representative drawbacks are the
wide band-gap energy, which allows only the absorption of the UV light from the solar spectrum, and their low
specific surface area. There are a few ways employed for solving the above mentioned problems such as the
doping of the photocatalysts with various chemical species (e.g. nitrogen or silver) or the addition of some noblemetal nanoparticles on the surface (for lowering the photocatalyst band-gap energy), and the use of sol-gel
method followed by the supercritical drying (for increasing the specific surface area) [2].
Based on the facts described above, the aims of the present work were the synthesis of N-doped TiO2
aerogels and the investigation of the Ag nanoparticles additions’ effect on its morphological and structural
properties as well as the correlation of the obtained results with photocatalytic data obtained by employing a
model-pollutant, i.e. salicylic acid. The synthesis of the aerogels was already described by us in previous works
[1, 2], while the N-doped samples were obtained by the addition of diethyl-amine and AgNO3 during the sol-gel
synthesis. The obtained aerogels were characterized by diffuse reflectance spectroscopy, X-ray diffraction, X-ray
photoelectron spectroscopy, transmission electron microscopy and sorption measurements. The data acquired
from the performed investigations shown that the induced changes in the band-gap values are closely related to
the results obtained from the photodegradation tests and to the presence of both nitrogen and silver species (Ag
nanoparticles and/or Ag+ ions) in the proximity of the mixed aerogels surface.
Acknowledgments: This work was supported by the grants of the Romanian National Authority for Scientific
Research, MNT ERA_NET nr.7-065/26.09.2012 and PN-II-ID-PCE-2011-3-0442.
References
1. W. Zhao, L. Feng, R. Yang, J. Zheng, X. Li, Applied Catalysis B: Environmental, 103, (2011) 181–189.
2. L. Baia, A. Peter, V. Cosoveanu, E. Indrea, M. Baia, J. Popp, V. Danciu, Thin Solid Films, 511-512, (2006)
512-516.
3. L. Baia, A. Vulpoi, T. Radu, É. Karácsonyi, A. Dombi, K. Hernádi, V. Danciu, S. Simon, K. Norén, S.E.
Canton, G. Kovács, Zs. Pap, Appl. Catal. B: Environmental, 148-149, (2014) 589-600.
81
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ORGANIC PHOTOVOLTAIC STRUCTURES BASED ON ZINC AND MAGNESIUM
PHTHALOCYANINE THIN FILMS
M. SOCOL1, C. BREAZU1, O. RASOGA1, A. STANCULESCU1, N. PREDA1, F. STANCULESCU2, M.
STOICANESCU3
1
2
National Institute of Material Physics,105 bis Atomistilor Street, , Bucharest-Magurele, Romania
University of Bucharest, Faculty of Physics, 405 Atomistilor Street, , Bucharest-Magurele, Romania
3
Transilvania University of Brasov, 29 Eroilor Boulevard, Brasov, Romania
We report the deposition of zinc and magnesium phthalocyanine (ZnPc and MgPc) thin films by spincoating technique. Metal phthalocyanines are suitable organic materials for photovoltaic structures due to the
high absorption in the visible range of the solar spectrum. In our study, different concentrations (1% (w/v), 2
%(w/v) and 3% (w/v)) of ZnPc or MgPc in dimethylsulphoxide (DMSO) were used. ZnPc and MgPc spincoating films were deposited on ITO, fused silica and silicon substrates. Optical and structural properties of the
films were characterized by UV-VIS, Photoluminescence and FTIR spectroscopy. Atomic Force Microscopy
(AFM) and Scanning Electron Microscopy (SEM) were used to investigate the grain size and the morphological
features of the obtained layers. We found out that the grain size of the films depends on the concentration of the
metal phthalocyanines in DMSO. I-V characteristics of (metal/organic/ITO/glass substrate) structures were
recorded in dark and under the illumination with solar simulator (AM1.5). A correlation between the layer grain
size and the optical and electrical properties of the obtained structures was made. Also, we observed an increase
of the current value and quantum efficiency with the increase of the layer grain size.
S1 P36
DESIGNING SUPERHYDROPHOBIC POLYMER SURFACES BY CONTROLLING THEIR
MORPHOLOGIES
M. SOCOL, N. PREDA, I. ZGURA, M. ENCULESCU, A. EVANGHELIDIS, C. FLORICA, E. MATEI, I.
ENCULESCU
National Institute of Materials Physics, Magurele-Bucharest, P.O. Box MG-7, R-77125, Romania
Due to their huge variety of properties, polymers have recently attracted the attention of researchers as choices
for designing, developing and producing superhydrophobic surfaces. In the present study by combining efficient
and suitable methods for covering large areas, like electrospinning or spin-coating, we have obtained
superhydrophobic polymeric surfaces (Fig. 1). Thus, complex spherical cage-like structures (a), porous films
with honeycomb-patterned structures (b) or sponge-like structures (c) and fibers and strings of beads smooth or
with pores on their surfaces (d, e, f) were obtained using polystyrene-hydroxyethyl methacrylate, polystyrene or
polymethylmethacrylate. A strong dependence between the surface wetting properties of the films and their
morphologies has been put in evidence. A hydrophobic/hydrophilic switch was observed after the polymeric
surfaces were treated in oxygen plasma.
Fig. 1: SEM images of polymer structures. In the insets the optical photographs of the water droplets shape on
the polymer surfaces and the water contact angles for the corresponding samples are shown.
82
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TUNABLE SURFACE WETTABILITY OF ZnO NANOSTRUCTURED FILMS PREPARED BY WET
CHEMICAL ROUTE
I. ZGURA, N. PREDA, M. SOCOL, M. ENCULESCU, A. EVANGHELIDIS, C. FLORICA, E. MATEI, I.
ENCULESCU
National Institute of Materials Physics, Magurele-Bucharest, P.O. Box MG-7, R-77125, Romania
Designing ZnO nanostructured films with tailored morphology is one of the key steps towards their
implementation in different application areas. The chemical deposition process is a suitable technique for
fabricating large-area ZnO uniform films. The present study is focused on the growth of ZnO films by simple
wet chemical routes using as reactants zinc nitrate and a reducing agent (hexamethylenetetramine, sodium
hydroxide or dimethylamineborane). For a complex characterization of the ZnO nanostructured films their
morphology, crystalline structure, optical and wetting properties were investigated. All samples have a
hexagonal wurtzite structure and optical signatures (band-gap value and emission bands) typical for ZnO. The
shape of the nanostructures (Fig.1) rods (a, b), flowers (c, d) and prisms (e, f) influences the contact angle values,
varying from a superhydrophobic behavior to a hydrophilic one.
Fig. 1: SEM images of ZnO nanostructures at different magnifications. In the insets the optical photographs of
the water droplets shape on the ZnO nanostructured films surfaces and the water contact angles for the
corresponding samples are shown.
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MAGNETIC STRUCTURE OF Fe/Cu(001) THIN FILMS
D. BENEA1, S. MICAN1, I. STANCIU1, A.F.TAKACS1, V. POP1
1
Faculty of physics, Babes-Bolyai University, Cluj-Napoca, Romania
Ab-initio band structure calculations of Fe films on Cu (001) substrate are presented. The films are modelled as
6Cu/nFe/6Vc slabs with n=1,2,4,6. Several ferromagnetic and antiferromagnetic spin configurations with
coupling of layer blocks have been considered, with the in-plane and out-of-plane direction of magnetization.
The mixing of deposited Fe atoms with the Cu substrate has been studied by using the Coherent Potential
Approximation (CPA). Total energy calculations have been performed and the most stable spin configurations
for unrelaxed fcc thin films are shown.
83
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HIGHLY TEXTURED IRIDIUM THIN FILMS GROWN ON MgO AND Si SUBSTRATES
Lucian TRUPINA, Liviu NEDELCU, Constantin Catalin NEGRILA, Marius CIOANGHER
National Institute of Materials Physics, Bucharest, Romania
Growth of perovskite oxides on silicon substrates for thin films devices has to be made on highly stable
bottom electrode in harsh condition as high temperature and oxygen atmosphere. The most used bottom
electrode is Pt/Ti/SiO2/Si but it has some problems of interdiffusion of Ti with Pt and hillocks formation [1,2].
An alternative for overcoming these limitations is to use iridium as bottom electrode due to its high thermal
stability, low oxygen permeability and good electric conductivity [3,4]. Experimental results on the growth of
iridium thin films on different substrates and their stability at high temperature (700 oC) are reported. Highly
textured (111) or (200) oriented iridium thin films were obtained on Si substrate buffered with a 5nm thick Ti
layer and on (100) MgO substrates, respectively. The crystalline structure, surface morphology and surface
chemical investigations were made using X-ray diffraction, atomic force microscopy and X-ray photoelectron
spectroscopy. (111) or (200) textured iridium thin films grow at 700 °C substrate temperatures, in argon at 5x10-3
torr working pressure and 0,25 Wcm-2 applied DC power density. Preliminary experiments on the thermal
stability of Ir/Ti/SiO2/Si system showed that it is stable under processing conditions of ferroelectric thin films
materials (700 oC and oxygen atmosphere) and can be successfully used as bottom electrode in ferroelectric thin
films devices.
a)
b)
Atomic force microscopy images of Ir thin film deposited on a) Ti/SiO 2/Si and b) MgO substrates
References:
[1] R. Bruchhaus, D. Pitzer, O. Eibl, U. Scheithauer, W. Hoesler: Mater. Res.Soc. Symp. Proc. 243, 123 (1992)
[2] J.O. Olowolafe, R.E. Jones, A.C. Campbell, P.D. Maniar, R.I. Hedge, C.J. Mogab: Mater. Res. Soc. Symp.
Proc. 243, 355 (1992)
[3] Z. Dai, C.B. Meinke, R. Loloee, B. Golding, Appl. Phys. Lett. 82, 3847 (2003)
[4] X. Yan, Q.Y. Zhang, X.D. Fan, Mater. Lett. 61, 216 (2007)
Acknowledgements: This work was supported by a grant of the Romanian Ministry of Education and Research,
CNCS - UEFISCDI, project number PN-II-ID-JRP-RO-FR-2012-0160
84
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DEPOSITION OF TITANIUM DIOXIDE LAYERS UPON TEXTILE MATERIALS: CHECKING THE
ADHERENCE BY ULTRA-SONICATION
Irina ZGURA, Stefan FRUNZA, Ligia FRUNZA, Monica ENCULESCU, Camelia FLORICA, Florin
COTOROBAI
National Institute of Materials Physics, PO Box Mg 07, 077125 Magurele, Romania
Titanium dioxide TiO2 is a transition metal oxide with UV absorbing properties which are very interesting from
a scientific standpoint and also due to technological applications in many fields. TiO 2 deposition at low
temperature by sol-gel or sputtering techniques was applied onto polyester textile materials and compared with
the deposition upon poly(lactic acid) and polyamide material. Polyester is known as less chemically active but
needs mild deposition conditions. Therefore we applied both a sol-gel and a sputtering method at a low (room)
temperature. Structural and spectroscopic characterization of the raw and deposited samples has been performed.
We found that the deposition leads to amorphous oxide particles; in fact amorphous layers are rarely mentioned.
TiO2 layer is quite adherent as checked by an ultra-sonication method.
Thus, functionalization of textile surface was performed either by sputtering (SP) deposition using a SputterCoater (Tectra GmbH) installation and a TiO2 target (99.9% oxide, K.J. Lesker) for 6 h at three pressures or by
sol-gel (SG) deposition in a home made dip coating installation. In some cases, TiO 2 layers were deposited onto
(cleaned) glass plates at the same time with the textile samples for an easy comparison.
We focus now on the check of this functionalization of the textile surface from the adherence point of view. The
composite systems were submited to a sonication treatment for 3 min or for 1h in an equipment UIS250V
(Hilscher Ultrasound Technology), the sample immersed in water being very close to the resonant horn.
SEM images of these composite systems (see some representative images in Fig. 1) after sonication (Fig 1a)
have indicated that the deposited fibers are quite similar to that without sonication (Fig 1b) showing that the
deposited layer is quite adherent. Increasing the duration of ultra sonication up to 1 h does not detach the
deposited layer but destroys only the interfiber bridges.
Ultrasounds may lead to phase transformation anatase-to-rutile of nanostructured TiO2 synthesized via sol–gel
technique. We could also observe some crystallization of the deposited matter.
Fig. 1: SEM images of TiO2 nanostructures at different magnifications: a) TiO2 layer submitted to ultrasonication process; b) TiO2 layer without ultra-sonication;
Acknowledgements. The authors gratefully thank the Romanian Authority of the Education Ministry for the
financial support under the project IDEI 281/2011 and Dr. A. Dorogan (National Institute for Textile & Leather,
Bucharest) for some textile samples.
85
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STRUCTURAL AND MAGNETIC PROPERTIES OF Nd2Fe14B/α-Fe NANOCOMPOSITES OBTAINED
BY MECHANICAL MILLING AND SHORT TIME ANNEALING
S. MICAN1, R. HIRIAN1, O. ISNARD2,3, I. CHICINAŞ4 AND V. POP1
1
2
Université Grenoble lpes, Institut Néel, Grenoble, F-38042 France
3
CNRS, Institut Néel, Grenoble, F-38042 France
4
Materials Science and Engineering Department, Technical University of Cluj-Napoca, Romania
The Nd2Fe14B+10% wt. α-Fe hard/soft magnetic nanocomposites were prepared by mechanical
milling for 2, 4 and 6 h, followed by short time annealing at 700 to 800 ºC for different times ranging from 0.5 to
2.5 minutes and quenched. The effects of different preparation, milling and annealing conditions on the
structural and magnetic properties of Nd2Fe14B/α-Fe magnetic nanocomposites were investigated. The influence
of soft phase pre-milling on the interphase exchange coupling was also studied. The width of the X-ray
diffraction peaks of the hard magnetic phase increases with increasing milling time, with the peaks disappearing
after 6 h of milling. Following annealing, the characteristic peaks of the hard magnetic phase are restored with a
limited growth of the soft magnetic phase crystallites. The magnetic behavior was investigated from hysteresis
curves and dM/dH vs. H plots [1, 2]. The best exchange coupling was obtained for the 6 h milled sample
annealed at 700 °C for 2 minutes with a maximum coercive field value of 0.44 T. Taking into account the
milling time and annealing conditions, the Nd2Fe14B/α-Fe exchange coupling is analyzed.
[1] V. Pop, S. Gutoiu, E. Dorolti, O. Isnard, I. Chicinaş, J. Alloys Compd., 509, 9964 (2011).
[2] V. Pop, S. Gutoiu, E. Dorolti, C. Leostean, O. Isnard, I. Chicinaş and O. Pana, J. Alloys Compd., 581, 821
(2013).
Acknowledgment
The authors would like to acknowledge support from the Romanian UEFISCDI Project No. PN-II-ID-PCE2012-4-0470.
86
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STRUCTURAL AND MAGNETIC PROPERTIES OF THE Mn50Al46Ni4 ALLOY
R. C. GAVREA1, S. MICAN1, B. V. NEAMŢU2, M. COLDEA1 AND V. POP1
1
2
Materials Science and Engineering Department, Technical University of Cluj-Napoca, Romania
Previous studies have shown that in the Mn-Al system a metastable phase (the tetragonal L10 or 
phase) with remarkable magnetic properties can be obtained, the most stable composition being Mn 54Al46 [1-3].
In order to decrease the weight of the antiferromagnetic interactions on the magnetic characteristics of the Mn-Al
system [1], we prepared the Mn50Al46Ni4 alloy and investigated its structural and magnetic properties.
Differential Thermal Analysis (DTA) measurements pointed out the formation of the metastable  phase around
743 K and its decomposition into the stable 2 and -Mn(Al) phases at 1123 K. X-ray Diffraction (XRD)
investigations show that all of the samples are phase mixtures. The  phase was found along with the ' phase
only in the as-cast sample and the ones annealed at 743 K, a fact confirmed by M(T) measurements which
showed two transitions at 445 K and 628 K, which correspond to the ferromagnetic  and  phases, respectively.
The samples annealed at 983 and 1123 K showed a single magnetic phase behavior with lower Curie
temperatures of 418 K (Al2Mn3) and 434 K ('-type phase) respectively. A maximum  phase concentration of
43% was found for the sample annealed at 743 K for 5 h. The close values of the theoretical and experimental
effective magnetic moments confirm the existence of the  and  phases in these alloys.
[1] H. Kono, J. Phys. Soc. Jpn., 13, 1444-1451 (1958).
[2] A. Sakuma, J. Phys. Soc. Jpn., 63, 1422-1428 (1994).
[3] T. E. Prost, "PhD Thesis: Magnetic Properties Study of the Mn-Al System with Additions of B or C and
Mechanical Milling Techniques", University of Nebraska – Lincoln, 2012.
Acknowledgment
The authors would like to acknowledge support from the Romanian UEFISCDI Project No. PN-II-ID-PCE2012-4-0470.
87
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OPTICAL PROPERTIES AND SELF-ASSEMBLING CAPACITY OF METAL-CONTAINING
SILOXANE POLYAZOMETHINES
Mirela ZALTARIOV, Maria CAZACU, Carmen RACLES, Angelica VLAD, Mihaela AVADANEI, Gabriela
HITRUC, Luiza Gradinaru, George STIUBIANU, Anton AIRINEI
” etru oni” Institute of Macromolecular Chemistr , Iaşi-700487, Romania
Imine polymers and their metal-derivatives have been especially studied for their thermal, optical,
electrical and electrochemical properties, the presence of metals in polymeric materials leading to new physical
properties and potential applications.
In this study a polyazomethine has been prepared starting from a siloxanice dialdehyde, bis(formyl-pphenoxymethyl)-tetramethyldisiloxane, and a diamine containing oxadiazole cycle in the structure, 2,5-bis(paminophenyl)-1,3,4-oxadiazol, and used as a ligand for Cu(II), Co(II) and Zn(II) ions. The presence in structure
of the highly flexible and hidrophobe tetramethyldisiloxane units improves the solubility of the polyazomethine
and its metal derivatives and induces self-organization capacity in film and solution, while the oxadiazole ring,
besides azomethine group, confers optical properties and the ability to complex metal ions. Thus, the film
morphology rised from the solvents with different polarities was studied by different techniques: AFM, SEM and
TEM (Fig. 1).
Figure 1. The AFM (a), SEM (b) and TEM (c) images of the polyazomethine-Cu complex in thin films deposited
from CHCl3
Absorption and photoluminescence properties were studied through UV-VIS and fluorescence
spectroscopies, respectively.
Acknowledgements: This work was supported by a grant of the Ministry of National Education, CNCS –
UEFISCDI, project number PN-II-ID-PCE-2012-4-0261 (Contract 53/02.09.2013).
88
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PHOTOPHYSICAL PROPERTIES OF SOME ANTHRAQUINONE DERIVATIVES
Ionut Radu TIGOIANU, Anton AIRINEI, Mirela ZALTARIOV, Mihaela HOMOCIANU, Petronela
DORNEANU, Nicusor FIFERE, Maria CAZACU
” etru oni” Institute of Macromolecular Chemistry, Iaşi-700487, Romania
The emission and absorption spectra of some siloxane anthraquinone derivatives have been studied in
different nonpolar and polar and solvents in order to estimate the interaction nature occurring in solution.
Electronic spectral studies reveal that the solvatochromic behavior depend not only on the solvent polarity but
also on the specific hydrogen bonding interactions.
By using nonpolar solvents (hexane, heptane, toluene, dioxane) the absolute values of the quantum
yields, QY, increased with decreasing the electrical permittivity and refractive index of the solvents from 4.48%
to 12.85%. In the case of polar solvents, especially alcohols (methanol, ethanol, 1-butanol) the absolute values of
the quantum yields, also increased with decreasing the electrical permittivity and with increasing the refractive
index from 9.21% to 10.88%. These variations of the quantum yields, can be explained by existence of different
interactions in solution (dispersion, orientation, etc.).
Also, by knowing the values of the quantum yields, we can consider that the non-radiative processes
are predominant in solution as against the radiative processes. This fact is determined by involving of the
vibrational relaxations (internal conversion, intersystem crossing).
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DIELECTRIC PROPERTIES OF Ba2/3Sr1/3TiO3 FERROELECTRIC CERAMICS
L. NEDELCU, L. TRUPINA, C. P. GANEA, C. D. GEAMBASU, M. CIOANGHER, M. G. BANCIU
Ferroelectric materials have been intensively studied in the last years for applications in electrically
tunable devices [1]. Among these, barium strontium titanate solid solutions have received much attention for
their large tunability and moderate dielectric loss. However, it is well known that near Curie temperature the Ba1xSrxTiO3 materials exhibit highest values of tunability [2]. Therefore, based on our precedent results [3],
Ba2/3Sr1/3TiO3 (BST) ceramics have been prepared and characterized. The BST samples were prepared from high
purity SrCO3, BaCO3, and TiO2 raw materials by using conventional ceramic technology. The ball-milled
powders were subsequently calcined in order to determine the temperature of the solid-state reaction. Singlephase BST powders calcined at 1225 oC/2h were sintered at temperatures between 1300 oC and 1400 oC. The
sintered BST pellets were morphologically and structurally characterized by scanning electron microscopy and
X-ray diffraction. Dielectric measurements carried out in a frequency band from 1 Hz to 1 MHz revealed a sharp
ferroelectric to paraelectric transition with Curie point near room temperature. The structural, morphological,
and dielectric data will be discussed and compared with some previous results [3-6].
References
1. L.B. Kong et al., Electrically tunable dielectric materials and strategies to improve their performances, Prog.
Mater. Sci. 55 (2010) 840.
2. A.K. Tagantsev et al., Ferroelectric materials for microwave tunable applications, J. Electroceram. 11 (2003)
5.
3. A. Ioachim et al., Barium strontium titanate-based perovskite materials for microwave applications, Prog.
Solid State Chem. 35 (2007) 513.
4. A. Ioachim et al., Transitions of barium strontium titanate ferroelectric ceramics for different strontium
content, Thin Solid Films 515 (2007) 6289.
5. L. Nedelcu et al., Dielectric properties of paraelectric Ba 1-xSrxTiO3 ceramics, Ferroelectrics 391 (2009) 33.
6. L. Nedelcu et al., Synthesis and dielectric characterization of Ba 0.6Sr0.4TiO3 ferroelectric ceramics, Thin Solid
Films 519 (2011) 5811.
Acknowledgements: This work was supported by a grant of the Romanian Ministry of Education and Research,
CNCS – UEFISCDI, project number PN-II-ID-JRP-RO-FR-2012-0160.
89
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BROADBAND DIELECTRIC SPECTROSCOPY OF Mg4Nb2O9 CERAMICS
L. NEDELCU, M. G. BANCIU, C. P. GANEA, G. V. ALDICA
Continuous evolution of the wireless communications emphasizes the jamming issues due to the
scarcity of the electromagnetic spectrum used in both terrestrial and space infrastructures. As a consequence,
microwave links tend to expand toward millimeter- and submillimeter-waves [1]. On this line, temperaturestable dielectrics with low-loss and high permittivity have been developed to carry forward the progress of the
telecommunications systems [2]. In this work, we report on the synthesis and characterization of the Mg 4Nb2O9
dielectric materials. The samples have been prepared by conventional ceramic technology from high purity MgO
and Nb2O5 oxides. The starting powders were homogenized in a planetary mill using ZrO 2 balls and jars. The
ball-milled powders were simultaneous investigated by differential thermal analysis and thermogravimetry in
order to determine the temperature of the solid-state reaction. Mg4Nb2O9 calcined powders have been sintered in
air at temperatures between 1300 oC and 1450 oC. The obtained samples with were structurally and
morphologically characterized by X-ray Diffraction and Scanning Electron Microscopy. The broadband
frequency behavior of the dielectric function was investigated through 3 different measurement techniques. At
low frequency the dielectric spectra were measured on parallel-plate capacitors with a Novocontrol Impedance
Analyzer. Microwave parameters were carried out on Mg4Nb2O9 dielectric resonators by means of the HakkiColeman method by using an Agilent PNA E8361A Network Analyzer. Millimeter- and submillimeter-waves
dispersion of the dielectric function was obtained on lamellae with thickness of about 0.2 mm. An Aispec pulse
IRS-2000 Pro time-domain spectrometer on transmission set-up was employed for terahertz measurements.
Several soft phonon modes have been evidenced by Terahertz Time-Domain Spectroscopy at frequencies
unavailable for conventional Fourier-Transform Infrared Spectroscopy. Experimental data will be discussed and
compared with some others temperature-stable microwave dielectrics [3-5] (Zr0.8Sn0.2TiO4, BaZn1/3Ta2/3O3,
BaMg1/3Ta2/3O3 etc.).
References
1. J. Federici, L. Moeller, Review of terahertz and subterahertz wireless communications, Journal of Applied
Physics 107 (2010) 111101.
2. M.T. Sebastian, Dielectric materials for wireless communication, Elsevier, Oxford, 2008.
3. A. Ioachim, M. G. Banciu, M. I. Toacsen, L. Nedelcu, D. Ghetu, H. V. Alexandru, G. Stoica, G. Annino, M.
Cassettari, M. Martinelli, Nickel-Doped (Zr0.8,Sn0.2)TiO4 for Microwave and Millimeter Wave Applications,
Mater. Sci. Eng. B 118 (2005) 205.
4. L. Nedelcu, M. I. Toacsan, M. G. Banciu, A. Ioachim, Microwave properties of Ba(Zn1/3Ta2/3)O3 dielectric
resonators, J. Alloy. Compd. 509 (2011) 477.
5. L. Nedelcu, C. Busuioc, M. G. Banciu, R. Ramer, Ba(X1/3Ta2/3)O3 complex perovskites for microwave and
millimeter wave applications, Proceedings of the 35 th International Semiconductor Conference, CAS 2012,
Sinaia, Romania, vol. 2 (2012) 303.
Acknowledgements: This work was supported by a grant of the Romanian National Authority for Scientific
Research, Programme for Research - Space Technology and Advanced Research - STAR, project number 85.
90
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WETTABILITY PROPERTIES OF TITANIA THIN FILMS
Catalin ADOMNITEI*, GHIORGHITA Liliana and Diana MARDARE
"Alexandru Ioan Cuza" University, Faculty of Physics, 11 Carol I Blvd., 700506 Iasi Romania,
[email protected]
Titanium dioxide (TiO2) is a promising photocatalytic material which, under the action of UV radiation,
possesses two important properties for the environment, such as: high oxidation of pollutants organic compounds
and a high affinity for water, and it is used in the purification of air, water, sterilization etc.. To improve the
hydrophilic and photocatalytic properties of TiO2, we have prepared films with different amounts of Ni and Mo.
To obtain a large active surface area, the films were deposited by spray pyrolysis. The as-deposited amorphous
thin films were subjected to a heat treatment in air (60 min at 400 ºC) to obtain polycrystalline structures. X-ray
Photoelectron Spectroscopy and Scanning Electron Microscopy confirm the existence of Ni and Mo atoms in the
TiO2 matrix. The optical transmittance spectra of the films were investigated, and the optical band gap was
derived for each film. The obtained values increase by increasing the Ni content in the films, and decrease by
increasing the Mo content. Surface wettability investigation indicates that, Ni doping drive to a decrease in the
hydrophilic properties, while Mo induces an improve of these properties.
Acknowledgements
This work was supported by grant POSDRU/159/1.5/S/ 137750
S1 P48
STRUCTURE OPTIMIZATION AND CHARACTERIZATION OF THIN FILMS CIGS SOLAR
CELLS
P. PREPELITA
National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, PO Box MG-36, Magurele
077125, Ilfov, Romania
In this paper I report on the CuIn1-xGaxSe2 (CIGS) solar cells realized by successive rf magnetron sputtering
deposition of thin films (CIGS/CdS/Au) onto different substrates (e.g. glass, polyamide) and coated with ITO
layer.
Structural properties of the deposited thin films (CIGS (1200 m), CdS (60 nm)) and contact electrodes (Au (500
nm) and ITO (300 nm)) were investigated.
AFM analysis showed that CIGS thin films have a high porosity. The CdS “reference sample” film directly
deposited onto substrate is characterized by a low surface roughness (Rrms = 2 nm) while the CIGS solar cell has
crystallites with a greater size (e.g. roughness is about 70 – 150 nm).
The surface topography of the samples was analyzed using scanning electron microscopy (SEM) and the
polycrystalline nature of the films was observed from XRD patterns.
91
S1 P49
MAGNETIC PROPERTIES OF Tb8-XYXCo16 COMPOUNDS
A. BEZERGHEANU1, C.RUSU1, D. BENEA1, I.GR.DEAC1, R.TETEAN1
1
Faculty of Physics, Babes-Bolyai University 400084 Cluj-Napoca, Romania
The structure, magnetic properties and the magnetic entropy change of Tb 8-XYXCo16 compounds with x =
1,2,3,4,5 and 6 have been investigated.
X-ray diffraction measurements confirm the formation of the cubic MgCu 2 (C15) structure in all of the
investigated samples. The lattice parameters were found to be little dependent on yttrium content.The magnetic
measurements were performed in the temperature range 4.2-700 K and external fields up to12T. The compounds
are ferrimagnetically ordered. The cobalt magnetic moments at 4.2 K decreases with increasing Y content from
B/Co atom. The Curie temperature was found to decrease from 206 (x=1) to 52 K
(x=6). The total density of states at the Fermi level decreases slightly when the yttrium content increase. The
calculated spin contribution to the magnetic moment of Tb is not too much affected by alloying, the total terbium
moment being close to the value determined by neutron diffraction studies. The 3d-4d hybridization is reduced
for the spin up states lowering the occupation of 4d spin up states while for the opposite spins the effect is
contrary. As a consequence a magnetic moment on Y site appears. The changes in the neighborhood of the Co
atoms through substitution of Y for Tb will modify the contribution associated with R 5d–M 3d hybridization
and finally the cobalt magnetic moment.
The magnetic entropy changes, ΔSM(T), peaks are broad and have a symmetrical shape around the transition
temperature for the samples with high terbium content, a behavior which is characteristic for materials exhibiting
a second-order magnetic phase transition. In the case of compounds with high yttrium content the shape of the
ΔSM(T) peaks are only approximately symmetric fact that suggest that the magnetic transition is not purely of
second-order. The obtained maximum entropy change values were found to decrease from 5.3 J/kgK for x = 1 to
1.9 J/kgK for x = 6 for a magnetic field change from 0 to 4 T.
High RCP(ΔS) values were found, due to the large δTFWHM values. It was found that the RCP(ΔS)/ΔB values
do not show a significant variation with varying Y concentration. For example, an RCP(ΔS)/ΔB value of 53.25
J/kgT was obtained for the sample with x = 1, while for the sample with x = 6 a value of 37.8J/kgT.
Due to their high RCP values these compounds are promising candidates for applications in magnetic
refrigeration devices.
S1 P50
APPROACH BASING ON NEURAL NETWORK
h sics, Chemistr and Environment Department, Facult of Sciences and Environment, “Dunarea de Jos”
University of Galati, Romania
The optical reflectance of Bi2O3 was measured for different five samples. The study is implemented for Bi2O3
films deposited by thermal vacuum evaporation at different temperatures of the glass substrates and the
comparison with the experimental data set being made using the transmission and the reflection optical spectra.
Two different neural network models were consdered in order to succeeed in evaluating the best metod for a
global representation of the temperature of the reflectance. The novelty of the present study is due to the
implementation of a MAPLE software approach to the complex computations implied by this assessment. The
neural network obtained fit of the reflectance spectrum is applied, accompanied by a careful selection of the
considered model.For each data set were considered 20 models and were presented the best ten of then. In the
final section were presented the best 10 models for the
Keywords: Numerical approaching; Kramers–Kronig analysis; Bi2O3 films; computational physics
92
S1 P51
THE TEMPERATURE-INDUCED TRANSITION IN SPIN-CROSSOVER ISING-LIKE MODEL WITH
FLUCTUATING EXTERNAL FIELD
A. MAKSYMOV2, IU. GUDYMA2, C. ENACHESCU1
1
Alexandru Ioan Cuza University of Iasi, Bulevardul Carol I, Nr. 11, Iasi 700506, Romania
2
Chernivtsi National University, Kotsubynski Str., Nr. 2, Chernivtsi 58012, Ukraine
E-mail: [email protected]
The nanoparticles play an important role in miniaturization the next generation media devices, taking into
account the development of available methods for the synthesis of nanomaterials. The functional properties of
magnetic spin-crossover nanoparticles represent especial interest due to their practical application as
informational materials, in particular as storage media of ultrahigh density. The spin-crossover compounds are
the class of inorganic coordination complexes with d  d electronic configuration and transition metal ion
central situated in the ligand field with octahedral symmetry [1, 2]. The main characteristic of spin-crossover
nanoparticles, which make promising their wide practical application, is molecular bistability due to inherent
high-spin (HS) metastable configuration and low-spin (LS) stable one of the sublevels of d d-orbital. Between
the HS and LS states of spin-crossover compound the interconversion is possible during the action of external
physical fields such as magnetic field, temperature, light irradiation, pressure etc.
Due to interaction of spin-crossover system with environment the action of external physical field cannot
be deterministic but fluctuate in time. In this case the behavior of nanoscopic spin-crossover system is more
correctly to analyze by microscopic Ising-like model with fluctuating external field. The Hamiltonian of such
system takes the following form:
4
H   J  si s j  hi  si ,
ij
where
7
(1)
i
hi  h0   t  . Here si , j are pseudospin scalar variables which take the values +1 for HS state and -1
J is spin-spin interaction; h0    kT ln g is external field depending on energy gap between
HS and LS states  , its multiplicity ratio g , and temperature T ( k is Boltzmann constant and for simplicity is
k  1 ). The term  t  is stochastic Gaussian non-Markovian process
for LS one;
describing the action of all possible fluctuations in microscopic spincrossover system taking into account its space-time correlation. The
behavior of phenomenological parameters of spin-crossover system under
noise influence was studied in [3]. In the Fig.1 are shown the actions of
fluctuation transition curves. As we can see the presence of fluctuations
provoke the widening of hysteresis loop.
[1] Spin Crossover in Transition Metal Compounds 1,2,3, edited by P.
Gütlich, H. Goodwin (Springer, Berlin, 2004)
[2] Iu. Gudyma, C. Enachescu, A. Maksymov Kinetics of nonequilibrium
transition in spin-crossover compounds in Nanocomposites,
Fig.1. The spin transition curves for
Nanophotonics, Nanobiotechnology, and Applications, edited by O.
different statistical characteristics
Fesenko, L. Yatsenko (Springer, Berlin, 2014) (in press)
of fluctuations.
[3] Iu. Gudyma, A.Maksymov, C. Enachescu Eur. Phys. J. B 78, 167
(2010)
93
S1 P52
THE ISING-LIKE THERMODYNAMIC MODEL OF SPIN-CROSSOVER COMPOUNDS
IU. GUDYMA, V. IVASHKO, A. MAKSYMOV
Chernivtsi National Universitiy, Kotsubynski Str., Nr. 2, Chernivtsi 58012, Ukraine
The spin-crossover compounds (SCO) are belonging to the family of bistable molecular solids and are
functional switching materials that can change their spin state under external physical perturbations (pressure,
radiation, temperature, the actions of magnetic or electric fields). Typically, these compounds are based on
transition metals ions with d  d electronic configuration which may have one of two stable states: high-spin
(HS) or low-spin (LS) state. The setting of spin-state is related to the balance between the orbital energy, which
is necessary for populating the all 3d sublevels, and the average energy of the Coulomb interaction between
electrons on the d-levels. If these energies values are approximately equal, then both states are populated and the
4
7
2
system is bistable. As a result of an external perturbation the spin state of Fe ion changes from diamagnetic
HS state to paramagnetic LS state. The ability to influence on the transition between the states of SCO
compounds by external fields is very promising for development the new types of switching and magnetic media
[1].
In this work we have studied the model of SCO material for the case where the deformations are
homogeneous and isotropic. The spin-crossover magnetic ions are situated in the crystal lattice sites of cubic
form and in follow undergo the limitations in the specific locations of regular spaces. The Hamiltonian of such
model was described in the following way:
H   h s i  J  s i s j 
where

i
{i , j }
{i , j }
1
 2  P ,

2 {i , j}
(1)
means that only the interaction between nearest neighbors are
si is a fictitious classical spin, which is characterized by
two eigenvalues  1 corresponding to the LS and HS states respectively; the
taken into account;
variation of  corresponds to a relative change of internal distance. The free
Gibbs energy per spin was calculated as follows:
g  zJ  s 2   K 2  P  k B T ln[ 2 cosh(
Fig. 1 The dependence of dynamic
parameters n H and  on temperature.
2 zJ 2  s  h
)] ,
k BT
(2)
where z is the number of nearest neighbors; K is bulk modulus of the
crystal lattice; J  J 0  J 1 is the exchange integral; h is the
external field; <s> = m is the value of magnetization;
J 0 is inter-ion
interaction constant, P is pressure; J 1 is the first derivative of the exchange integral over tensions. From the Eq.
(2) we can obtain the dependence of magnetization on temperature and internal distance. These dependences are
shown in Fig.1.
1. Spin Crossover in Transition Metal Compounds I-III, Top. Curr. Chem. No. 233-235/ eds. Gütlich P. and
Goodwin H. – Berlin, Heidelberg : Springer-Verlag, 2004.
94
S1 P53
OPTICAL PROPERTIES OF WIDE-BANDGAP SEMICONDUCTING OXIDES FOR DYESENSITIZED SOLAR CELLS USE
Florin MOSCALU,1 Gabriel PRODAN,1 and Anca DUMBRAVA2,*
1
2
Department of h sics and Electronics, Ovidius Universit of Constanţa, Romania
Department of Chemistr and Chemical Engineering, Ovidius Universit of Constanţa, Romania
Wide bandgap semiconductors, such as TiO2 and ZnO, are commonly used in dye-sensitized solar cells
and in photocatalytic processes. In order to absorb visible light and generate the electron–hole pairs for
photocatalysis, the oxide should be functionalized, for instance by coupling to a narrow band gap sensitizing
semiconductor. Another way to improve the optical properties, involving the band gap energy, is the tuning of
particle dimension by choosing the proper synthesis method and/or conditions.
We studied the variation of zinc oxide band gap energy, which was estimated using the Tauc equation,
for powders and films obtained by different methods [1]. The structure and morphology of ZnO were
investigated by electron diffraction and transmission electron microscopy, and the optical properties were
studied using UV-Visible diffused reflectance spectroscopy. The values of band gap energy were correlated
with particle dimension (as a result of synthesis method) and with the functionalization process. Compared to
bulk ZnO (Eg = 3.37 eV), the values obtained for ZnO nanopowders are higher (around 3.50 eV), respective the
absorption bands are broader in the functionalized semiconductor, this behavior involving superior photoelectrochemical applications.
[1] A. Dumbrava, G. Prodan, F. Moscalu, Mater. Sci. Semic. Proc. 16, 1095 (2013).
*E-mail: [email protected]
S1 P54
POLYMER NANOSTRUCTURES AS REINFORCING AGENTS FOR ZINC OXIDE –EUGENOL
(ZOE) MATERIALS
G. CALIN1, L. DARTU1, L. OLARU2, F. IACOMI3, V. BURLUI1, N. OLARU2
1
2
Facult of Medicine, “ pollonia” Universit of Iasi, Iasi, Mu icii Street, no. 2, Iasi, Romania
“ etru oni” Institute of Macromolecular Chemistr , leea Grigore Ghica-Voda 41 A, Iasi, 700487, Romania
3
Facult of h sics, “ lexandru Ioan Cu a” Universit of Iasi,
Carol I Blvd. Iasi, Romania
It is known that zinc oxide – eugenol (ZOE) pastes can be used to temporary or permanent cement cast
restoration or appliances. Presence of eugenol in pastes has a soothing effect on the pulp and that is why ZOE
cement is preferred for patients who might have tooth sensitivity following a cavity filling procedure.
Commercial ZOE materials are presented in different compositions which influence physical and clinical
characteristics of pastes. Addition of polymers as reinforcing agents can transform ZOE into a final cement and
intermediate restorative material with an improved compressive strength.
This paper sought to improve physical and clinical properties of ZOE materials by addition of polymer
nanostructures as reinforcing filler in their composition. Polymer nanofibers and nanoparticles investigated in
this paper were obtained by electrospinning technique using cellulose acetate as starting polymer. Nanostructures
as obtained were deacetylated and the resulted cellulose nanofibers and nanoparticles were used as reinforcing
filler for ZOE materials. Physical and clinical characteristics of these pastes were studied.
95
S1 P55
SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF AAO/METALLIC NANOCOMPOSITE
G. CALIN1, L. DARTU1, V. BURLUI1, E. VASILE2, R. TRUSCA2, F. IACOMI3
1
Facult of Medicine, “ pollonia” Universit of Iasi, Iasi, Mu icii Street, no. 2, IasiRomania
2
SC METAV-Research and Development SA, 31C A Roseti Street, Bucharest, Romania
3
Facult of h sics, “ lexandru Ioan Cu a” Universit of Iasi,
Carol I Blvd. Iasi, Romania
Metallic nanotubes have attracted the interest of researchers due to their fundamental importance and potential
applications in nanodevices, sensors, catalysts and conversion / energy storage [1, 2].
AAO/metallic nanocomposite was obtained by using a sol-gel method that uses ultrasonic vibrations to induce
the penetration of a coloidal solution through the pores of an anodized aluminum oxide (AAO) template. The
AAO template, with the sol into its pores, was annealed at 648 K. The entire ‘dip–anneal–dip’ process was
repeated three times. Finally, the metal nanotubes were formed by further annealing at 873 K in hydrogen
atmosphere for 1 h.
The morphology and structure of AAO matrix were investigated by using XRD and SEM methods. HRTEM and
EPR analysis evidenced the formation of metal nanotubes in the AAO matrix.
[1]ZhuY C, Zheng H G, LiY, Gao L S, Yang Z P and Qian Y T 2003 Mater. Res. Bull. 38 1829
[2]Wang Q T, Wang G Z, Han X H,Wang X P and Hou J G 2005 J. Phys. Chem.
S1 P56
PANCHROMATIC HARVESTING TECHNIQUES APPLIED FOR NATURAL DYES IN DYESENSITIZED SOLAR CELLS
Alexandru ION,1 Jeanina LUNGU,2 and Anca DUMBRAVA1,*
1
Department of Chemistr and Chemical Engineering, Ovidius Universit of Constanţa, Romania
2
Department of h sics and Electronics, Ovidius Universit of Constanţa, Romania
The efficient absorption over the entire visible and near IR spectrum is a requirement and also an
aspiration for dyes used in dye-sensitized solar cells (DSSCs). This property is difficult to be assigned to a single
dye and the combination of multiple dyes is considered to be a promising approach for obtaining panchromatic
systems.[1, 2]
For harvesting light over a wide range of wavelengths, we used two techniques to obtain DSSCs with
mixtures of natural pigments, namely the successive adsorption of dyes and some cocktails of dyes.[3] The
natural dyes were extracted from red cabbage, respective green algae. The cocktails were prepared for different
dyes ratios and at different values of pH. The photovoltaic performance of a photoelectrode adsorbed with
single-dye (red cabbage or green algae) otherwise the mixture or successive adsorption of the two dyes was
evaluated from current–voltage measurements. The efficiencies and the values of fill factors were dependent on
the cocktail composition and on the pH value, and were superior for two-dyes cells compared to those obtained
for single-dye cells.
[1] J.H. Yum, E. Baranoff, S. Wenger, Md. K. Nazeeruddin, M. Graetzel, Energy Environ. Sci. 4, 842 (2011).
[2] N. Robertson, Angew. Chem. Int. Ed. 47, 1012 (2008).
[3] K.H. Park, T.Y. Kim, S. Han, H.S. Ko, S.H. Lee, Y.M. Song, J.H. Kim, J.W. Lee, Spectrochim. Acta A 128,
868 (2014).
96
S1 P57
SOME OPTICAL PROPERTIES OF YbF3 DOPED BaF2 AND CaF2 CRYSTALS
Madalin BUNOIU, Marius STEF, Gabriel BUSE and Irina NICOARA
West University of Timisoara, Faculty of Physics, Blvd. V. Parvan 4, Timisoara 300223, Romania
In the last time the interest in rare-earth-doped fluorite crystals used as laser material is still growing
due to the well known good optical characteristics of the MeF 2 (Me = Ca, Ba, Sr) host. The Ytterbium ions are
most easily stabilized as trivalent ions in MeF2 crystals, but the divalent state has certain distinct advantages for
laser applications [1, 2]. The change of valence has been attained by baking the crystals in a suitable atmosphere
[3,4], by electrolytic coloration or exposing them to ionizing radiation [3,5]. The properties of Yb 2+ ions have
been less investigated than the properties of the trivalent Yb.
In this work we report the growth and some optical properties of YbF 3- doped MeF2 (Me=Ca, Ba) crystals
with high divalent Yb ions concentration obtained without any other treatment. Me1-xYbxF2-x (x = 0.0007 and
0.017) crystals have been grown using the conventional Bridgman technique [6]. In order to obtain high
Yb3+Yb2+ conversion a special procedure has been developed. The optical absorption spectra of the crystals
exhibit intense UV absorption bands, characteristic for divalent Yb ions. It is known that the optical properties of
the crystals depend on the relative Yb2+,3+ and F- ions positions in the lattice. The Yb3+ ions substitute for Me2+
ions in the lattice and need charge compensation obtained by an interstitial fluoride ion located in various
positions giving rise to a rich multisite structure, which leads to broad absorption and emission bands. The Yb 2+
ions substitute for Me2+ ions, do not need charge compensation and posses cubic symmetry.
Preliminary luminescence studies reveal a strong concentration dependence of the near UV emission
bands. The emission spectra of the MeF2:Yb2+ crystals have been investigated by other authors by exciting only
in 365 nm absorption band [1,2,3]. For the first time we studied the emission spectra of the MeF 2 crystals
exciting in all absorption bands.
References
[1] A. A. Kaplyanskii et al., Opt. Spectrosc. 41(1976) 615,
[2] S. Lizzo et al. J. Lumin. 63(1995)223,
[3] S. M. Kaczmarek et al. J. Phys.: Condens. Mater. 17(2005)3771,
[4] A.S. Shcheulin, A.E. Angervaks, T.S. Semenova, L.F. Koryakina, M.A. Petrova, P.P. Fedorov, V.M.
Reiterov, E.A. Garibin, A.I. Ryskin, Appl. Phys. B 111 (2013) 551-557
[5] D. S. McClure and Z. Kiss, J. Chem. Phys. 39(1963)3251,
[6] D. Nicoara and I. Nicoara, Mater. Science and Eng. A 102, L1 (1988)
S1 P58
TEMPERATURE DEPENDENCE OF THE OPTICAL PROPERTIES OF Bi2O3. A
THEORETICAL APPROACH BASING ON THE KRAMERS-KRONIG TRANSFORMATION FOR
POLYNOMIAL DIFFERENT TERMS MODELS
h sics, Chemistr and Environment Department, Facult of Sciences and Environment, “Dunarea de
Jos” Universit of Galati, Romania
The optical reflectance of Bi2O3 was measured for different five samples. The study is implemented for
Bi2O3 films deposited by thermal vacuum evaporation at different temperatures of the glass substrates and the
comparison with the experimental data set being made using the transmission and the reflection optical spectra.
Two different neural network models were consdered in order to succeeed in evaluating the best metod for a
global representation of the temperature of the reflectance. The novelty of the present study is due to the
implementation of a MAPLE software approach to the complex computations implied by this assessment. There
are presented two different polynomial approach method in a comparative way
Keywords: Numerical approaching; Kramers–Kronig analysis; Bi2O3 films; computational physics
97
S1 P59
ON THE PHYSICAL PROPERTIES OF DIFFERENT OXIDES THIN FILMS OBTAINED BY
THERMAL OXIDATION
Sorina IFTIMIEa, A. RADUa, R. MALLETb, L. IONa, Mihaela GIRTANb, S. ANTOHEa
a
MDEO Research Center, Faculty of Physics, University of Bucharest, Romania
b
LPHIA Laboratory, LUNAM – Angers University, France
ZnO, AZO, ITO and NiO oxides thin films were obtained by direct thermal oxidation of sputtered
layers (Zn, Zn:Al, In:Sn and Ni, respectively). The thermal treatment was gradually performed from room
temperature (RT) up to 550°C. Two different arrangements were taken into account for the obtained samples:
parallel, denoted horizontal, and perpendicular, denoted vertical, to plasma flow. X-ray measurements were used
to investigate the structural features of the obtained oxides thin films. The morphological characteristics were
analyzed using atomic force microscopy (AFM, contact mode) and scanning electron microscopy (SEM).
Optical transmittance in the visible range (300 – 800 nm) was measured for all the samples, at room temperature.
The electrical behavior was analyzed using van der Pauw method (300 – 10 K).
Thermal oxidation can be an alternative to obtain transparent oxides thin films, potentially conductive
used as buffer or dielectric layers.
Acknowledgments: S.I. is grateful to the Pays de la Loire and Angers University for the post-doc fellowship No
2012-12029 financial support.
S1 P60
THE SPECTRAL RESPONSE OF CdS/CdTe PHOTOVOLTAIC CELLS WITH DIFFERENT TCO’s
A. RADUa, Sorina IFTIMIEa, L. IONa, Raluca CONSTANTINEANUa, Veta GHENESCUb, M. GHENESCUb,
S. ANTOHEa
a
MDEO Research Center, Faculty of Physics, University of Bucharest, Romania
b
Institute of Space Science, Magurele-Ilfov, Romania
Photovoltaic cells based on CdS/CdTe heterojunction were prepared by thermal vacuum evaporation
technique (TVE) onto optical glass substrates. Indium tin oxide (ITO) and ITO/IGZO thin films were used as
transparent conductive oxides (TCO’s). Indium gallium zinc oxide (IGZO) layers were deposited onto ITO by
magnetron sputtering technique and their physical properties were investigated. The surface morphology was
investigated by scanning electron microscopy (SEM) and the structural features were determined by X-ray
measurements. Optical transmittance was higher that 60% in the 200 – 1100 nm and the calculated values of the
band gaps were similar with those in literature. Based on this, photovoltaic structures with different TCO’s and
having CdTe as absorber layer were made and their photovoltaic performances were compared. Parameters
characterizing photovoltaic cells like, external quantum efficiency (EQE) were calculated and compared for the
prepared samples.
The obtained experimental data presented in this study showed that IGZO thin films could be an
alternative as transparent conductive oxides for photovoltaic structures. Moreover, IGZO thin films behave as
photoactive layer shifting the action spectra toward the shorter wavelength, and improving the photovoltaic
performances of the prepared cells.
Acknowledgements
Partially this work was supported by the Project CDI-STAR ,,Stability tests on new photovoltaic structures for
space applications against the protons and alpha particles irradiation”, No. 64/2013
98
S1 P61
DEVELOPING AND TESTING A THIN FILM SAMPLE HOLDER FOR ION BEAM ANALYSIS
Victor RUNCEANU, Adrian ROTARU
"Horia Hulubei" National Institute of Physics and Nuclear Engineering - IFIN-HH, 077125 Magurele, Romania
The demand for Particle Induced X-ray Emission (PIXE) and Particle Induced Gamma-Ray Emission (PIGE)
measurements of thin films encouraged us to design and develop a new type of sample holder. The ensemble is
interchangeable with the existing thick target sample holder, fitted on the same multi-axis goniometer ( µm
resolution). A new Faraday cup was also integrated into the design, allowing us to measure currents behind the
target, down to 0.1nA. 3D printing and Computer Numerical Control (CNC) machining were used for
manufacturing the thin film sample holder. The system is housed inside the Ion Beam Analysis (IBA) chamber
of the 3MV Cockcroft-Walton Tandem Particle accelerator at IFIN-HH. This new configuration allows the
calculation of materials stopping power, along with PIXE and PIGE measurements. For the measurements, thin
samples made from liquids and dissolved organic material deposited on Mylar films are used (e.g. fruits,
vegetables, mollusks).
Keywords: thin film, IBA, PIXE, PIGE, transmission, RBS, stopping power, Faraday cup.
S1 P62
MANUFACTURING A SYSTEM FOR PIXE AND PIGE ANALYSIS ON THIN FILMS USING 3D
PRINTING AND COMPUTER AIDED DESIGN
Adrian ROTARU, Victor RUNCEANU
"Horia Hulubei" National Institute of Physics and Nuclear Engineering - IFIN-HH, 077125 Magurele, Romania
A method for elemental analysis of liquid solutions and thin films by IBA techniques, as well as ion stopping
power is presented. Liquid droplets are attached to a thin Mylan film and evaporated, leaving dry constituents.
The samples are irradiated with protons at the 3MV Tandetron accelerator of IFIN-HH, Măgurele. Particle
induced X-ray emission (Pixe) and particle induced Gamma-emission (Pige) are extensively employed to study
the elemental composition of various substances. We have developed a device to help us perform Pixe and Pige
on liquid droplets. Rutherford back scattering (RBS) can be employed to study ion stopping power of thin films.
The device we’ve created was developed using Computer aided design (CAD) and contains plastic polymer and
metal components. The plastic parts were manufactured using a micrometer-precision 3D printer and the metal
parts using computer guided milling. Thus rapid development and testing was possible, along with cheap
manufacturing costs. We’re designed this device to be used in conjuncture with the existing experimental setup,
therefore no modifications were necessary to the reaction chamber in order to accommodate the new upgrade.
The device consists of a carousel that can support up to 18 targets, a system to align the targets with the ion beam
optical axis and a Faraday cup with electron-suppressor to measure transmission currents.
Keywords: thin film, IBA, transmission, RBS, PIXE, PIGE, stopping power, faraday cup
Section 2 – LASER, PLASMA AND RADIATION PHYSICS AND APPLICATIONS
SECTION
S2 – Laser, Plasma and Radiation Physics and Applications
Laser Physics and applications
Plasma Physics and applications
Optoelectronics and photonics
Applied and non-linear optics
Ultrafast phenomena and applications
99
100
INVITED LECTURES
S2 L01
COLD AND HOT PROBE DIAGNOSTICS
Roman SCHRITTWIESER, Codrina IONITA, Stefan COSTEA,
Franz MEHLMANN, Johannes GRÜNWALD, Bernd S. SCHNEIDER
Association EURATOM/ÖAW, Innsbruck Experimental Plasma Physics Group, Institute for Ion Physics
and Applied Physics, University of Innsbruck, Austria
Probes are small test electrodes inserted into the plasma. From the probe's current-voltage (I-V)
characteristic plasma density, electron temperature, floating potential and plasma potential can be deduced.
Probes can on one side perturb the plasma, on the other side probes can be affected in various ways by the
plasma, even be destroyed. The basic handling of probes is easy, while their exact theory is very complex.
Probes are simple to construct and inexpensive. Although their invention is usually ascribed to Irving
Langmuir, who has developed and described both cold and electron-emissive probes, probably already William
Crookes has used probes. He was the first to call ionized gases the fourth state of matter.
Being material objects, probes can on one side perturb the plasma, on the other side probes can be affected
in various ways by the plasma, sometimes even be destroyed. Therefore measurements might suffer from
systematic errors. In any case, we always have to keep in mind that the basic handling of probes is easy, while
their exact theory is very complex.
Particularly in metallic and reactive plasmas, the probe surface can be physically or chemically altered: it
can be sputtered by plasma ions, unwantedly heated by the probe current, coated or etched by the plasma
material or even melted in hot and dense plasmas. All these effects can influence the probe measurements,
mainly due to the change of the probe's work function. A part of these effects can be avoided or mitigated if the
probe surface is kept clean which means usually heating so that contaminations from the surface evaporate.
In this review first a brief introduction into probes and their theory will be given. Then cold probes will be
treated and in particular problems related to measuring the plasma potential. In particular emissive probes –
which are simple tools for directly obtaining an approximate measure of the plasma potential also in
unmagnetized plasmas – will be treated in detail. Finally probes in certain types of reactive plasma will be
discussed, i.e. the magnetized alkaline plasma created by contact ionization in a Q-machine (Quiescent plasma
machine).
101
S2 L02
APPLICATION OF THE BALL-PEN PROBE IN SLIGHTLY MAGNETIZED LOW-TEMPERATURE
DISCHARGE PLASMA
M. ZANÁŠKA1, M. PETERKA1,2, J. ADÁMEK2,P. KUDRNA1, M. TICHÝ1
1
Charles University in Prague, Faculty of Mathematics and Physics, Department of Surface and Plasma
Science, V Holesovickach 2, 180 00 Praha 8, Czech Republic
1
Institute of Plasma Physics AS CR, Za Slovankou 1782/3, 182 00 Praha 8, Czech Republic
The space (or plasma) potential is most widely estimated by using a Langmuir probe. From the probe's
current voltage characteristics many plasma parameters can be found. In periodic plasma fluctuations the timeresolved probe measurements are possible. However, the time-resolved probe measurements in irregular
fluctuations are rather complicated, see e.g. [1]. If only the variations of the space potential have to be
determined the direct probe methods of its estimation are useful, e.g. the emissive or, in case of a magnetized
plasma, the ball-pen probe [2]. The ball-pen probe consists of a metallic collector, which is shielded by an
insulating tube; the probe head itself must be oriented perpendicular to magnetic field lines. The ball-pen probe
floating potential should yield the space potential. However, the internal impedance of the ball-pen probe at
floating potential as a signal source is much larger that of classical Langmuir probe. Hence the ball-pen probe
signal was measured using a high-input-impedance voltage follower (1G). In the irregular discharge
fluctuations the ball-pen probe as well as the Langmuir probe measured the time-averaged data while the
emissive probe was able to follow the plasma fluctuations.
In this work we compared the space potential measurements by ball-pen probe in the slightly
magnetized discharge argon plasma by measurements using the classical Langmuir probe. In Langmuir probe
measurements the plasma potential was estimated from the abscissa of the maximum of the first derivative of the
current-voltage Langmuir probe characteristic. During measurements both probes were inserted in the discharge
vessel simultaneously using two vacuum ports. The measurements were performed in argon within the pressure
range 1-14 Pa, discharge current 60-100 mA and the magnetic field 40 mT. By plotting the difference between
the data estimated from the Langmuir and from the ball-pen probe with respect to the similarity parameter B/p
we believe that we found the limit of the proper operation of the ball-pen probe towards low magnetic fields and
higher pressures.
[1] L. Albarède, S. Mazouffre, A. Bouchoule, M. Dudeck, Physics of Plasmas 13, 063505 2006
[2] J. Adamek, J. Stockel, M. Hron, et al., Czech.J.Phys. 54, 95 2004
Acknowledgment. The authors would like to acknowledge the financial support by the Charles University in
Prague, Faculty of Mathematics and Physics, by EURATOM and by the CEEPUS project AT-0063.
102
S2 L03
PERIODIC STRUCTURES FORMATION ON BERYLLIUM, CARBON, TUNGSTEN FILMS MIXED
FILMS BY TW LASER IRRADIATION
C. P. LUNGU1, C. M. TICOS1, C. POROSNICU1, I. JEPU1, M. LUNGU1, P.DINCA1, O. POMPILIAN1, D.
URSESCU1, R. BANICI1, G. COJOCARU1, R. UNGUREANU1, C. LUCULESCU1, A. MARCU1, R.
VLADOIU2, A. MARIN3, I. FERARU4, C. GRIGORESCU4
1
National Institute for Lasers, Plasma and Radiation Physics, Magurele, jud Ilfov, Romania
2
”Ovidius” University, Constanta, Romania
3
“Ilie Murgulescu” Institute of Physical Chemistry, Bucharest, Romania
4
National Institute R&D for Optoelectronics INOE 2000, Bucharest, Romania
Very intense laser irradiation produces effects that affect the structure and morphology of the bulk
materials and thin films.
Due to the interest of the study of the behavior of materials used in the fusion technology, pure Be, C,
W and mixed films were tested under direct and indirect irradiation of a laser beam produced by TWALAS
facility of NILPRP. The films, prepared by thermionic vacuum arc (TVA) method interacted with the plasma
produced in the gaseous environment by laser irradiation in order to simulate the plasma-wall phenomena
appearing during fusion device operation. The laser power was 17 TW, pulse duration: 70 fs, the pulse energy: 6
mJ and the repetition rate: 10 Hz. The laser beam was directed parallel with the films surfaces in air and
deuterium atmosphere. In the focal point intense plasma was formed and interacted with pure and mixed films.
The films were characterized before and after exposure using scanning electron microscopy (SEM), Xray photoelectron spectroscopy (XPS) and Raman spectroscopy.
On the irradiated samples elongated craters with depth correlated with the number of the applied pulses
(1000, 300, 100, 30 and 1) were observed. The irradiated film surfaces show film morphologies with periodic
structures. This observation could be of interest for the creation of surfaces with variable morphology at the
micron level. The XPS analyses clearly display a mixture of metallic and oxide berylium or tungsten with the
metallic feature increasing with the sampling depth as a result of a diminishing amount of Oxygen. BeO, WO 3
and W3O9 oxides were observed on the top layer of the irradiated samples. The concentration of the sp3 bonding
component in the carbon conaining mixed films shows a tendency to increase with the sampling depth,
accompanied by a corresponding decrease of the sp2 feature. We observed also the carbon film melting with a
re-solidification effect into a form of nano-crystalline graphite.
Acknowledgements: Funding by the Romanian National Authority for Scientific Research, UEFISCDI, through
project number PN-II-ID-PCE-2011-3-0522 is acknowledged
103
S2 L04
BIOACTIVE COATINGS FOR DENTAL AND ORTHOPAEDIC IMPLANTS
BIOFUNCTIONALIZATION
A.VLADESCU1, C. VITELARU1, M.DINU1, M. BRAIC1, I.PANA1, A.KISS1, I.TITORENCU2, V. BRAIC1
1
2
National Institute for Optoelectronics, 409 Atomistilor Str., Magurele, Romania
Institute of Cellular Biology and Pathology Nicolae Simionescu, 8 B.P.Hasdeu Str., Bucharest, Romania
The bioactive coatings are frequently used to improve the osseointegration of the metallic implants used
in dentistry or orthopaedics. Among different types of bioactive coatings, hydroxyapatite (HAPCa10(PO4)6(OH)2) is one of the most extensively used due to its chemical similarities to the components of bones
and teeth. Despite their remarkable osseointegration and bioactivity characteristics, it was demonstrated that
HAP coating presents low mechanical strength which restricts its use as biomaterial. Improvement of mechanical
and anticorrosive properties, as well as superior osseointegration of the HAP coated titanium alloy were reported
in the last years by the addition of different elements (Si or Ti) into HAP films.
The aim of this work was to investigate the HAP coatings enriched with SiC in order to enhance
mechanical, electrochemical and biological properties of HAP films. All the coatings were prepared by RF
magnetron sputtering. The pure HAP coatings were obtained by sputtering of pure HAP target in an Ar
atmosphere, at 700 °C substrate temperature. The HAP with SiC coatings were prepared by co-sputtering of
HAP and SiC targets. The RF power fed on HAP cathode was constant (50W) and on SiC was varied (10W,
15W and 20W).
The coatings were analyzed for elemental and phase composition, crystalline structure, morphology,
mechanical characteristics, corrosion resistance and biocompatibility. The HAP+SiC coating characteristics were
assessed in comparison to pure HAP coatings, taken as reference. Also, the effect of the silicon content to the
properties of the HAP+SiC coatings was analyzed.
The nanoindentation results show that presence of SiC interlayer has affirmative effect on mechanical
properties of HAP coatings on Ti alloy substrate. Also, it was demonstrated that the anticorrosive and biological
characteristics of HAP coatings deposited on Ti6Al4V substrate were improved by addition of SiC to the basic
HAP structure. So, the HAP enriched with SiC could be a possible candidate for osseointegration in orthopaedic
or dental applications.
Acknowledgements: This work was supported by a grant of the Romanian National Authority for
Scientific Research, CNCS-UEFISCDI the project number PN-II-RU-TE-2011-3-0284.
104
S2 L05
COMPLEX STUDY OF BINARY NANOCOMPOSITES DEPOSITED BY THERMIONIC VACUUM
ARC (TVA) TECHNOLOGY
Rodica VLADOIU, Aurelia MANDES, Virginia DINCA
Dep. of Plasma Physics, Faculty of Applied Science and Engineering,
Ovidius University, Mamaia 124, Constanta, 900527, Romania
Composite materials at the nanometer level started to be real dimensions for coating the components on
production line. The challenge of this research is to find the best combination for coating the mechanical parts of
components by suitable complex nanocomposites and by using innovative technology. Specifically, complex
carbon and titanium based nanocomposites owing to their remarcable properties of the coating surfaces such as
wear resistance, roughness, low friction coefficients have been synthetized and investigated in different
combination and forms, such as multi-component composites.
Multicomponent thin films (binary –SiC, TiC and MgC) were deposited using Thermionic Vacuum Arc
(TVA) technology. The thin films were characterized using X-ray diffractometer (XRD, Philips PW1050, Cu K),
scanning electron microscope (SEM, Zeiss EVO 50 SEM) accompanied with energy dispersive spectrometer,
transmission electron microscope (TEM, Phillips CM 120 ST, 100 kV) and wettability by surface free energy
(SFE).
The SiC film is composed of nanoparticles very smoothly distributed of 15-30 nanometer size
embedded in amorphous matrix film. The results reveal high hardness for SiC (10-40 GPa). Also, the surface
free energy (SFE) was determined by means of Surface Energy Evaluation System (See System) indicating a
hydrophobic character for C-Mg and TiC thin films.
Keywords: carbon, nanomaterials, Silicon, Titanium, Magnezium, TEM, TVA.
Acknowledgements: This work was supported by a grant of the Romanian National Authority for
Scientific Research, CNDI–UEFISCDI, project number 160/2012, PN-II-PT-PCCA-2011-3.2-1453.
105
S2 L06
RADIATIVE PROCESSES IN BULK AND TWO-DIMENSIONAL LAYERED CRYSTALS OF
MOLYBDENUM AND TUNGSTEN DICALCOGENIDES
Leonid KULYUK
Institute of Applied Physics, Academy of Sciences of Moldova,
Academiei Str. 5, Chisinau, MD-2028, Republic of Moldova
1.
2.
3.
4.
Transition metal dichalcogenides (TX2) such as MoS2, WS2 or WSe2 are semiconducting layered materials,
whose electronic and optical properties depend on the number of layers. [1]. In their two-dimensional (2D) form
the TX2 compounds are promising building blocks for novel semiconductor heterostructures [2]. Owing to their
layered structure, some physical properties of these indirect band gap bulk semiconductors can be modified by
intercalation of foreign atoms and molecules into the van der Waals gap [3]. Despite a rich body of research on
the intercalation complexes of transition metal dichalcogenides, the intercalation of the halogen molecules in
lamellar TX2 crystals has not been sufficiently investigated [4 and refs. therein].
This work concerns the radiative properties of 2H-WS2, 2H- and 3R-MoS2 bulk crystals and 2D flakes
intercalated with halogen molecules (Br2, I2 or Cl2). The single crystals were grown through the chemical-vapor
method, using iodine, bromine and chlorine as transport agents. Single- and few-layer flakes of TX2 samples
have been obtained by mechanical exfoliation of bulk crystals.
The luminescence spectra of a single layer flakes are dominated by strong emission bands, located at around 2eV
and 1.9eV for WS2 and MoS2 respectively, which correspond to the predicted excitonic recombination across the
direct gap of single-layer TX2 samples.
At low temperatures the IR photoluminescence sharp lines are observed at energy values nearly 0.1eV lower
than those of the indirect band gaps of the bulk crystals. We show this to be produced by bound excitons related
to the transport agent, intercalated in TX2 samples. The diatomic halogen molecules unambiguously positioned
in the adjacent tetrahedral sites of the van der Waals gap yield neutral centers, providing an efficient radiative
recombination. Because of their large electronic affinity, the halogen molecules exhibit properties of electronattractive centers, creating a short-range potential similar to that of the isoelectronic traps in the indirect band
gap semiconductors. The structure of the excitonic emission spectrum of each MoS 2 polytype is individual,
which can be used for the identification of the 2H and 3R polytypes.
In addition, a structured IR luminescence broad band associated with an intrinsic defect (deep center) of the TX 2
host lattice was detected for bulk samples. A kinetic model is proposed to describe the recombination processes
taking place in the halogen-intercalated TX2 crystals. The fast thermal quenching of the sharp-lines emission at T
>50K is accounted for by the self-trapping of the bound excitons. The simulation, relying on the experimentally
determined lifetime and energy values of the excitonic states, shows a good agreement with the observed
luminescence characteristics.
Q. H Wang, K. Kalantar-Zadeh, A. Kis, J. N. Coleman, M. S. Strano Nat. Nanotechnol. 2012, 7, 699.
A. K. Geim, I. V. Grigorieva Nature 2013, 499, 419.
E. Benavente, M. A. Santa Ana, F. Mendizábal, G. González, Coordination Chemistry Reviews 2002, 224, 87.
D. Dumchenko, C. Gherman, L. Kulyuk, E. Fortin, E. Bucher Thin Solid Films 2006, 495(1–2), 82.
106
S2 L07
WAVEGUIDES FABRICATED IN Nd:YAG BY DIRECT fs-LASER WRITING REALIZATION AND LASER EMISSION UNDER DIODE-LASER PUMPING
Nicolaie PAVEL,1 Gabriela SALAMU,1 Flavius VOICU,1 Traian DASCALU,1
Florin JIPA,2 and Marian ZAMFIRESCU2
National Institute for Laser, Plasma and Radiation Physics, Bucharest R-077125, Romania
1
Laboratory of Solid-State Quantum Electronics
2
Solid-State Laser Laboratory, Laser Department
email: [email protected]
The optical writing is nowadays a powerful method for realizing waveguides in various transparent optical
materials. This technique employs a femtosecond (fs)-laser beam to induce changes of the refractive index, the
modifications being dependent of the medium type and of the fs-laser beam parameters [1]. Waveguides were
fabricated in various laser media, from which efficient laser emission was obtained in principal under the pump
with a Ti:sapphire laser [2].
In this work we present our recent results regarding realization of waveguide lasers in Nd:YAG by the direct
fs-laser beam writing method, and on emission at 1.06 m and 1.3 m from these waveguides using the pump
with a fiber-coupled diode laser.
In the first experiments we used a step-by-step translation technique [3] to inscribe two-wall type and
cladding waveguides with various shapes (circular, elliptical and rectangular) in Nd:YAG single crystals and
Nd:YAG ceramic media. The waveguides propagation losses were measured. The laser emission was obtained
using the pump at 807 nm with a fiber-coupled diode laser. For example, laser pulses at 1.06 m with 0.9-mJ
energy and with 0.4-mJ energy at 1.3 m were obtained from a two-wall type waveguide with a separation of 40
m that was inscribed in a 5-mm long, 0.7-at.% Nd:YAG single crystal. The overall optical-to-optical efficiency
(o) was 0.20 at 1.06 m and ~0.09 at 1.3 m, while the slope efficiency (s) amounted to 0.28 and 0.17,
respectively. Furthermore, a circular waveguide with 110-m diameter that was fabricated in the same Nd:YAG
yielded an increased 1.4-mJ pulse energy at 1.06 m (with o~0.15 and s= 0.22). Circular waveguides of
various diameters were fabricated in longer (8.0 mm) Nd:YAG ceramics with 0.7-at.% and 1.1-at.% Nd, for
which the laser performances will be discussed [4, 5].
We have also developed a new method of writing circular waveguides by moving the laser medium on a
helical trajectory during the inscribing process, the medium direction of translation and the fs-laser beam being
parallel [6]. Circular waveguides with well defined walls and low propagation losses were realized in a 1.1-at.%
Nd:YAG ceramic, and efficient laser emission was obtained. Laser pulses at 1.06 m with 4.1-mJ energy (at
o~0.31 and s= 0.36) were obtained from a waveguide with 50-m diameter, and a 100-m in diameter
waveguide yielded laser pulses at 1.3 m with 1.2-mJ energy (at o~0.09 and s= 0.12). This kind of devices
shows good potential for realization of compact, efficient laser sources for optoelectronics.
Acknowledgements This work was financed by a grant of the Romanian National Authority for Scientific
Research, CNCS - UEFISCDI, project number PN-II-ID-PCE-2011-3-0363.
[1] A. Ródenas et al, Appl. Phys. B. 95 (1), 85-96 (2009).
[2] F. Chen and J. R. V´azquez de Aldana, Laser Photonics Rev. 8 (2), 251-275 (2014).
[3] A. G. Okhrimchuk, A. V. Shestakov, I. Khrushchev, J. Mitchell, Opt. Lett. 30 (17), 2248-2250 (2005).
[4] N. Pavel, G. Salamu, F. Voicu, F. Jipa, M. Zamfirescu, and T. Dascalu, Laser Phys. Lett. 10 (9), 095802
(2013).
[5] G. Salamu, F. Jipa, M. Zamfirescu, and N. Pavel, Opt. Express 22 (5), 5177-5182 (2014).
[6] G. Salamu, F. Jipa, M. Zamfirescu, and N. Pavel, Opt. Mater. Express 4 (4), 790-797 (2014).
107
S2 L08
OPTIMISATION OF MECHANICAL PROPERTIES OF nc-TiC/a-C:H COATINGS
Vilma BURSIKOVA, Pavel SOUCEK , Petr VASINA, Ondrej CAHA, Jiri BURSIK, Vratislav PERINA
Lukas Zabransky , Masaryk University, Brno,Czech Republic
The aim of the present work was to prepare nanocomposite materials consisting of nanocrystalline titanium
carbide embedded in an amorphous (hydrogenated) carbon matrix (nc-TiC/a-C:H). Combining the properties of
hard titanium carbide grains and softer a-C:H matrix, the mechanical properties can be tailored from very hard
films with hardness reaching over 40 GPa and Young’s modulus higher than 300 GPa o softer low friction films
with friction coefficient around 0.1 and low wear rate. Magnetron sputtering of titanium target in acetylene
containing atmosphere was used for nc-TiC/a-C:H preparation. The aim of this work was to study the structure,
mechanical and tribological properties of 4-6 micrometers thick coatings deposited onto industrially attractive
substrates such high speed steel and cemented tungsten carbide. Special focus was given on the analysis of the
influence of deposition conditions (i.e. hydrocarbon supply, ion flux) on the mechanical properties and the
thermal stability of prepared coatings.
S2 L09
OPTICAL AND ELECTRICAL INVESTIGATIONS ON TRANSIENT PLASMAS
GENERATED BY LASER ABLATION IN VARIOUS TEMPORAL REGIMES
S. GURLUI1, P. NICA2, M. AGOP2, M. OSIAC3, C. FOCSA4*
1) Faculty of Physics, Alexandru Ioan Cuza University, 700506 Iasi, Romania
2) Department of Physics, Gh. Asachi Technical University, 700050 Iasi, Romania
3) Faculty of Physics, University of Craiova, 200585 Craiova, Romania
4) Laboratoire de Physique des Lasers, Atomes et Molécules, Université Lille 1,
59655 Villeneuve d’Ascq, France
Our recent research has focused on the electrical (Langmuir probe) and optical (space- and time-resolved
optical emission spectroscopy) characterization of the dynamics of transient plasmas generated by nanosecond,
picosecond and femtosecond laser ablation of metallic targets in vacuum [1-4]. The occurrence of two structures
with distinct life-times and expansion velocities has been evidenced experimentally and simulated theoretically
in the frame of a new fractal hydrodynamic model [1, 2]. The first part of the transient ionic signal recorded by a
Langmuir probe presents an oscillatory structure, which has been correlated with the transient current recorded
on the target [3, 4].
In the particular case of femtosecond laser ablation of various metallic targets (W, In, Te, Mn, Ni, Cu, Al),
the time-dependence of the probe current is discussed assuming a shifted Maxwellian velocity distribution. By
applying various probe biasing voltages and current time-integration, the probe volt-ampere characteristics were
obtained. Two types of particles (hot and cold) are evidenced as having different temperatures and expansion
velocities. An additional positive target biasing gives a residual ion current as consequence of center-of-mass
velocity changing, and the probe characteristic is shifted with a constant value. At higher pressure (~10 -2 Torr),
an interesting behavior was observed in the electronic branch of the volt-ampere probe characteristics: periodic
drops of the current for specific values of the probe bias. Some hypothesis on the origin of this peculiar behavior
will be presented, along with a tentative correlation with the physical properties of the various metals
investigated.
[1] S. Gurlui, M. Agop, P. Nica, M. Ziskind, C. Focsa, "Experimental and Theoretical Investigations of a
Laser Produced Aluminum Plasma", Phys. Rev. E, 78, 026405 (2008)
[2] C. Ursu, S. Gurlui, C. Focsa, G. Popa, “Space- and time-resolved optical diagnosis for the study of laser
ablation”, Nucl. Instrum. Meth. B, 267, 446 (2009)
[3] P. Nica, M. Agop, S. Gurlui, C. Focsa, “Oscillatory Langmuir probe ion current in laser-produced
plasma expansion”, Eur. Phys. Lett., 89, 65001 (2010)
[4] P. Nica, M. Agop, S. Gurlui, C. Bejinariu, C. Focsa, “Characterization of Aluminum Laser Produced
Plasma by Target Current Measurements”, Jpn. J. Appl. Phys., 51, 106102 (2012)
KEYWORDS:
laser ablation, plasma plume dynamics, fractal hydrodynamic model ,Langmuir probe
108
S2 L010
ULTRAFAST LASER NANOSTRUCTURING ON LARGE SURFACES
Marian ZAMFIRESCU, Catalina ALBU, Gabriel COJOCARU, Simion. SANDEL, Catalin LUCULESCU
National Institute for Laser, Plasma and Radiation Physics, Atomistilor 409, 077125 Măgurele, Romania
The ultrashort pulsed lasers are intensively used for fundamental research and technological
developments in the field in material processing and characterization. In a "bottom-up" approach, under laser
irradiation below the ablation threshold, periodical structures with sub-wavelength periodicity can be selforganized providing an efficient method for nano-texturing of large areas for application such as fabrication of
hydrophobic surfaces, bio-mimetic surfaces, surfaces with modified tribologic properties, color marking of
metals.
The laser induced surface nanostructures appears on almost any kind of materials irradiated by ultrashort
laser pulses. However, the main issue regarding such processing technique remains the control of the
nanostructures morphology. In this work the control parameters of the Laser Induced Periodical Surface
Structures (LIPSS) are investigated, such as focusing geometry, pulse duration, temporal pulse shape, and
thickness of the irradiated films.
Metals and dielectrics with different thicknesses or bulk
Ni
Pt
materials are irradiated by focused single or multiple femtosecond
laser pulses. The pulse duration was varied from 200 fs to several
ps. Monopulses and double pulses with time delays from subpicosecond up to tens of ps were used. High Spatial Frequencies
LIPSS (LSFL) with periods in the range of 500 - 700 nm, as well
as High Spatial Frequencies LIPSS (HSFL) with periods from 100300 nm are obtained, depending on the irradiation conditions. A
Cr
SiO2
strong dependence of the nanostructures morphology with diameter
of the focused spot was also observed. When the samples surface is
scanned with the laser beam focused by microscope objectives with
high numerical aperture, HSFL structures are predominant on the
surfaces. The results are correlated with the plasmonic properties of
the surfaces such as the wavelength or the propagation length of the
surface plasmons. Various substrates are nanostructured by
Fig. 1. LIPSS on various materials.
femtosecond laser pulses on large areas of tens to hundreds of
Scale bar is 1 m.
mm2. Potential applications of laser nano-textured surfaces are
discussed.
Acknowledgements: This work was supported by a grant of the Ministry of National Education, CNCS –
UEFISCDI, project number PN-II-ID-PCE-2012-4-0539.
References
[1] C. Albu et al., Periodical structures induced by femtosecond laser on metals in air and liquid environments,
Appl. Surf. Science 278, 347-351 (2013).
[2] M. Zamfirescu et al., The role of the substrate material type in formation of laser induced periodical surface
structures on ZnO thin films, Appl. Surf. Science 258, 9385-9388 (2011).
109
S2 L011
HIGH POWER LASER SYSTEM IN ROMANIA AND LASER DEVELOPMENTS ROADMAP FOR
ELI-NP
Ioan DANCUS1,2, Daniel URSESCU1,2, Liviu NEAGU1,2, Mihail CERNAIANU1, Theodor ASAVEI1, Razvan
DABU1,2, Ion MORJAN1,2, Sydney GALES1, N.V. ZAMFIR1
1
Extreme Light Infrastructure-Nuclear Physics, IFIN-HH, Bucharest-Magurele, Romania
2
INFLPR, Bucharest-Magurele, Romania
ELI Nuclear Physics facility in Romania [1] is part of a broader pan-European distributed facility that addresses
also specific research subjects in the field of secondary radiation sources (in Czech Republic [2]) and attosecond
science (in Hungary[3,4]).
The development of High Power Lasers Systems (HPLS) in Romania will be presented and the ELI-NP laser
facility will be introduced. The ELI-NP HPLS is specified to have two laser arms that can deliver 10 PW each
with a repetition rate of one pulse per minute. Each laser arm can be used at higher repetition rate and lower
power: 100TW @ 10 Hz, 1PW @ 1Hz. In order to achieve the required contrast, of 10 12 :1, the Front End of the
laser system will be based on OPCPA and will include crossed polarized wave system (XPW). The following
amplification stages to reach the required high power are Ti:Sapphire based. The resulting laser beams are
transported to five experimental area where dedicated experiments are envisaged. The beam transport system
shall include beam conditioning systems such as plasma mirror, circular polarization and adaptive optics. The
ELI-NP HPLS is design to reach high intensities on the targets, on the order of 10 23 W/cm2.
[1] Daniel Ursescu, Ovidiu Tesileanu, Mihail O. Cernaianu, Sydney Gales, N. V. Zamfir, The Review of Laser
Engineering, vol 42, (p123-126) 2014
[2] B. Rus, P. Bakule, D. Kramer, G. Korn et al., 87801T (May 7, 2013), doi:10.1117/12.2021264
[3] S. Banerjee, M. Baudisch, J. Biegert, A. Borot, A. Borzsonyi et al., CLEO: 2013, OSA Technical Digest
(online) (Optical Society of America, 2013), paper CTu2D.6
[4] C. L. Arnold, F. Brizuela, A. Borot, F. Calegari, CLEO: 2013, OSA Technical Digest (online) (Optical
Society of America, 2013), paper JTh2A.13
110
ORAL PRESENTATIONS
S2 OP1
PLASMA BASED PROCESSES FOR SYNTHESIS OF METAL-POLYMER NANOCOMPOSITES
Veronica SATULU1, Bogdana MITU1, Simona SOMACESCU2, Ionela SARBU3, Diana PELINESCU3,
Gheorghe DINESCU1
1 National Institute for Lasers, Plasma and Radiation Physics,
PO-Box MG-36, 077125, Măgurele - Bucharest, Romania
2 “Ilie Murgulescu” Institute of Physical Chemistry, Bucharest, Romania
3 University of Bucharest, Centre for Research, Education and Consulting in Microbiology, Genetics and
Biotechnology (MICROGEN), Bucharest, Romania
Organic-inorganic nanocomposites are among the most studies systems nowadays due to their unique
properties which combine in a synergistic manner the characteristics of individual components [1]. Therefore,
such materials have found an extensive range of application in various fields, from energy storage to catalysis or
biomedical materials. In particular, metallic nanoparticles embedded in polymeric matrices are of high interest
for biomedicine [2].
In this context, the present contribution illustrates, based on two practical examples, the versatility of
plasma techniques for the synthesis of metal-polymer nanocomposites.
In a first approach, a combined PVD-PECVD system was employed for obtaining copper and titanium
polysiloxane nanocomposites. Metal nanoparticles were provided by RF magnetron sputtering of metallic target,
while plasma polymerization of hexamethyldisiloxane (HMDSO) precursor conducted to the formation of
organic based matrix. Separate control of the matrix properties and on the dimension of the metallic inclusions is
provided by means of time of exposure and the distance between the substrate and each of the plasma sources.
The second example approaches a multistep method based on low pressure RF plasma utilization for
obtaining polyethylene glycol - silver (PEG-Ag) nanocomposites on polymeric foils. It consists of polymer
surface activation by exposure to oxygen plasma, followed by surface grafting of colloidal dispersion of Agethylene glycol and plasma induced graft polymerization upon plasma exposure, conducting to Ag-PEG
nanocomposites. In this case, the control is achieved by proper tuning the number of active sites on the polymer
surface, and by Ag concentration in the colloidal suspension.
The material characteristics as regarding the morphology, chemical composition and bonding were
determined by means of Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy
(FTIR), and X-ray Photoelectron Spectrsocopy (XPS), respectively. The antimicrobial effect against various
strains as S. aureus, E. coli and C. albicans was demonstrated.
[1] Guido Kickelbick, Progr. Polym. Sci., 28 (2003) 83–114;
[2] D. R. Monteiro, L. F. Gorup, A. S. Takamiya, A. C. Ruvollo-Filho, E. R. de Camargo, D. Barros Barbosa,
Int. J. Antimicrob. Ag., 34 (2009) 103–110
111
S2 OP2
LUMINESCENCE PROPERTIES IN LANGATATE CERAMICS DOPED WITH Tm3+ AND Yb3+
Cristina MATEI1,2, Serban GEORGESCU1, Ana-Maria VOICULESCU1, Angela STEFAN1,2, Octavian TOMA1
1
National Institute for Lasers, Plasma and Radiation Physics, 077125 Magurele-Bucharest, Romania
University of Bucharest, Faculty of Physics, 405 Atomistilor Street, 077125 Magurele-Ilfov, Romania
[email protected]
2
Ultraviolet (365 nm, 1D2 → 3H6), blue (480 nm, 1G4 → 3H6), red (650 – 660 nm, 1G4 → 3F4 + 3F2,3 →
H6), and infrared (800 nm, 3H4 → 3H6) upconversion luminescence, were obtained for the first time in
La3Ga5.5Ta0.5O14:Tm:Yb ceramic sample, synthesized by solid-state reaction (obtained from stoichiometric
quantities of high purity oxides: La2O3, Ga2O3, Ta2O5, Tm2O3, Yb2O3) pumped at 973 nm. Yb3+ → Tm3+ energy
transfer processes accounting for population of the emitting levels of Tm3+ are discussed. Also, the backtransfer
process Tm3+ → Yb3+ was observed. The decay curves of the metastable levels 1D2, 1G4, 3H4, and 3F4 of Tm3+
and 2F5/2 of Yb3+ were analyzed. The cross-relaxation microparameters of Tm3+ were found. The efficiency of the
Yb3+ → Tm3+ transfer was estimated.
All the synthesized samples were checked for the phase purity using X-ray diffraction. The diffraction
lines belong to the langatate phase (card PDF 00-047-0532). Besides these diffraction lines, very-low-intensity
extra diffraction lines, which could be attributed, respectively, to LaGaO 3 (card PDF-01-072-8227) and to βGa2O3 (card PDF-00-041-1103) are observed.
We measured the absorption spectra of the LGT:Tm:Yb sample, in the UV-VIS and in IR domains. Due
to experimental limitations (in the UV-domain - the intrinsic absorption of LGT crystal and in IR, the spectral
sensitivity of the InGaAs detector) the absorption spectra were measured in the 325 nm – 1800 nm wavelength
domain.
3
The luminescence spectra of LGT:Tm:Yb sample were excited at 365 nm (transition 3H6 → 1D2), at
465.8 nm (3H6 → 1G4) and by upconversion, at 973 nm, via Yb 3+ absorption (2F7/2 → 2F5/2).
The decay curves of the 1D2, 1G4 and 3H4 Tm3+ levels were studied using the Inokuti-Hirayama,
Burshtein and Yokota-Tanimoto models, assuming dipole-dipole interactions between the rare earth ions. The
decay curves of 1D2 and 1G4 could be described well using the Inokuti-Hirayama model; the microparameters
obtained are CDA = 5×10-39 cm6s-1 and 1.7×10-39 cm6s-1, respectively. In the case of 3H4 level, the decay curve
presented migration effects; both Burshtein (hopping) and Yokota-Tanimoto (diffusion) models were tested on
this decay curve; the adequate model was Yokota-Tanimoto, yielding CDA=4.8  10-40 cm6s-1 and CDD=2.0  10-41
cm6s-1. The presence of Yb3+ in the samples did not influence significantly the decay of 3H4, in accord with the
low intensity of the Yb3+ luminescence obtained when pumping in the Tm3+. An efficiency of the Yb3+ → Tm3+
energy transfer of 16.4 % was estimated.
Acknowledgement.This work was supported by the Romanian Executive Agency for Higher Education,
Research, Development and Innovation Funding (UEFISCDI), in the frame of the Projects IDEI 82/06.10.2011.
112
S2 OP3
MULTIPLE THz PULSES GENERATED BY OPTICAL FILAMENTATION
T. DASCALU1, O. GRIGORE1,2, M. DINCA2, N. PAVEL1, G. COJOCARU1,2, R. UNGUREANU1,2, R.
BANICI1
1
National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor str, PO Box MG-36, Magurele,
077125, Romania
2
Universitatea Bucuresti, Facultatea de Fizica, 455 Atomistilor str, PO Box MG-11, Magurele, 077125,
Romania
High intensity THz pulses are of great interest for large proteins conformational changes and nonlinear
physics. Multiple THz pulses open ways in very interesting pump-probe experiments and fueled the research in
this field.
By self focusing phenomena the short and high energy laser pulses can generate a plasma filament in air
and interact with it in a large variety of physical phenomena such as ponderomotive force or Cerenkov emission
from laser wake field. Laser induced gas plasma is used to generate directional, coherent, broadband and very
intense THz pulses through various nonlinear processes. This method based on the interaction of very short laser
pulse with the plasma generated by laser pulse itself was later refined to use two different wavelength laser
pulses giving ten times more intense THz radiation [1].
Here we present a new method to obtain THz pulses from multiple filaments with a controlled delay and
various energy ratio between first and second THz pulse. The laser pulse parameters used for experiments
typically are few mJ and 40fs and the experimental setup is presented in fig.1 for two methods: (a) spectral
clipping, (b) thin film beam splitter method.
Figure 1.The experimental setup used for THz emission and detection.
THz pulse shape is detected by using electrooptical sampling. The multiple pulses high energy THz
radiation is presented in fig. 2.
The experimental results show the implications of optical pulse polarization on THz pulse intensity and
are very useful for refining the experimental setup.
113
S2 OP4
LASER EMISSION AT 1.06 μm IN Nd: GdLuCOB AND Nd:GdCOB CRYSTALS
Catalina BRANDUS, 1, 2 Lucian GHEORGHE, 1 Flavius VOICU, 1, 2 and Traian DASCALU1
1
Laboratory of Solid State Quantum Electronics,
National Institute for Laser, Plasma and Radiation Physics, Bucharest R-077125, Romania
2
Doctoral School of Physics, Faculty of Physics, University of Bucharest, Romania
Exploring gain materials with suitable self-frequency-doubling nonlinear properties is important for
developing compact and efficient laser devices with applications like optical data storage, laser display,
spectroscopy, or medical treatment [1-3]. Discovering new such nonlinear crystals is also demanding and few
papers discussed results obtained with a novel Nd:GdLuCOB crystal that could yield improved laser emission as
compared to the Nd: GdCOB medium [4, 5].
In this work we report on the infrared laser emission at 1.06 m in Nd:GdLuCOB and Nd:GdCOB single
crystals under quasi-continuous wave pumping with a fiber-coupled diode laser at 812 nm. For example, a 4.5mm thick, 5.0-at.% Nd:GdLuCOB crystal yielded laser pulses with 3.3-W peak power for an absorbed peak
pump power of 12.8 W, corresponding to an overall optical-to-optical efficiency (with respect to the absorbed
pump power) of oa~0.26; the slope efficiency was sa= 0.38. Furthermore, a 6.5-mm thick, 4.0-at. %
Nd:GdCOB crystal outputted laser pulses with 3.4 W peak power (at oa= 0.29) and slope sa= 0.34. Both the
laser crystals were uncoated. The design methods for these lasers, starting with the crystals growth and
preparation, the choice of the laser resonator and characterization of the output performances are discussed.
Experiments on self-frequency-doubling doubling in Nd:GdLuCOB are under investigation.
Acknowledgements This work was financed by a grant of the Romanian National Authority for Scientific
Research, CNCS-UEFISCDI, project number PN-II-ID-PCE-2011-3-0801 and by the International Cooperation
Project 3 RO-FR / 03.01.2012, Romania - France.
[1] G. Lucas-Leclin et al, J. Opt. Soc. Am. B. 17 (9), 1526-1530 (2000).
[2] Y. Shao et al, Laser Physics Lett. 8 (10), 715-718 (2011).
[3] J. Wang et al, Opt. Express 18 (11), 11058-11062 (2010)
[4] L. Gheorghe, P. Loiseau, G. Aka, and V. Lupei, Opt. Mat. 30 (1), 44-46 (2007).
[5] C. Gheorghe, L. Gheorghe, P. Loiseau, and G. Aka, J. Appl. Phys. 111, 013102 (2012).
114
POSTERS
S2 P01
SYNTHESIS AND CHARACTERIZATION OF MAGNESIUM EMBEDDED IN CARBON MATRIX
BY USING THERMIONIC VACUUM ARC (TVA) TECHNOLOGY
Aurelia MANDES, Rodica VLADOIU, Virginia DINCA
Magnesium is one of the lightest hydrogen storage material known; it is also abundant and inexpensive,
but some properties such high binding energy of hydrogen and the slow kinetics of uptake still could not satisfy
the demands of application fields. One possible way to improve magnesium thin films properties is to prepare
composites of Mg and other materials such as C-Mg composite.
The aim of this paper is investigate the growth and structure properties of C-Mg thin films deposited by
Thermionic Vacuum Arc (TVA) technology in one electron gun configuration on silicon, glass and OLC 45
special substrate, with great applications in the industrial area.
The properties of the deposited C- Mg thin films were investigated in terms of morphology, tribology
and wettability. The thin films were characterized using Scanning Electron Microscopy with energy-dispersive
X-ray detection (SEM/EDX) and the quantitative assessment of surface roughness was performed by analyzing
the topographies with an Olympus LEXT OLS4000 (CLSM). Also, the surface free energy was determined by
means of SEE System indicating a hydrophobic character and the morphology were determined from BF-TEM
image performed by Philips CM 120 ST TEM system.
To summarize, the deposited film presents a good hydrophobic character meaning that the surface had a
high contact angle for water and ethylene glycol, as well a small value for the surface free energy. The energy
dispersive X-ray (EDX) analysis of the deposited films indicates that the distribution of Mg and C particles was
uniformly homogenous in all samples. Aslo, TEM images revealed high uniformity and smoothnesses of the
coatings with great interest for emerging coating applications.
Keywords: C-Mg thin films, TVA method, TEM, SEM/EDX.
Acknowledgements: This work was supported by CNDI–UEFISCDI, project 78/2013, PN-II-ID-PCE2012-4-0059
115
S2 P02
BIOMEDICAL APPLICATIONS OF POLYMERS TREATED BY DCSDBD
Virginia DINCA, Rodica VLADOIU, Aurelia MANDES
Medical polymers are widely used because of their excellent mechanical and biological properties. The
surface properties of materials play an essential role in determining their biocompatibility and strongly influence
their biological response. So it is important to have biomaterials with the right surface properties to achieve the
biocompatibility of artificial biomaterial surfaces.
Plasma treatments are frequently employed to modify surface properties of materials such as adhesivity,
hydrophobicity, oleophobicity etc. Present work deals with surface modification of polymers such as
polycarbonate (PC) and polyester (PE) by diffuse coplanar surface dielectric barrier discharge (DCSDBD) at
atmospheric pressure in air and helium. One of the advantages of this technique is that it offers the possibility of
inducing significant surface chemical modifications on a material exposed to the discharge at atmospheric
pressure at different treatment times, 1 min, 5 min and 10 min in this work.
The DCSDBD reactor used in our experiments consists of two electrodes separated by a 100x100 mm 2
alumina dielectric plate of 0,5 mm thickness. The alumina plate has a discharge electrodes system on its upper
surface and an induction electrode on its lower surface. In this way the thin diffuse plasma layer is generated
without any direct contact with electrodes, protecting the electrodes erosion.
Material characterization was carried out by contact angle measurements using water, ethylene glycol and
formamide as testing liquids. The plasma-induced modifications are associated with incorporation of polar
oxygen and nitrogen containing groups on the polymer surface. The results reveal that the water contact angles
of the Polyester surfaces treated for 1 min decrease from 74.68 0 (untreated sample) to 50.020 (treated in air) and
to 38.330 (treated in Helium). The treated surfaces present a modified morphology with an increased wettability
compared to the untreated ones, effect which is favourable for the physical adsorption at the surface.
Keywords: Medical polymers, Dielectric Barrier Discharge, atmospheric pressure, Contact angle
measurement
Acknowledgements: This work was supported by CNDI–UEFISCDI, project 78/2013, PN-II-ID-PCE2012-4-0059
S2 P03
ELECTRON BEAM FLUE GAS TREATMENT IN THE PRESENCE OF FINE WATER DROPLETS
Daniel IGHIGEANU1, Ioan CALINESCU2, Elena MANAILA1, Gabriela CRACIUN1
1
National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor, Magurele, 077125, Romania, email: [email protected]
2
University Politehnica of Bucharest, Faculty of Applied Chemistry and Material Science, 149 Calea Victoriei,
Bucharest,010072, Romania
The present research highlights the advantages of the high energy electron beam irradiation treatment in
the presence of fine water droplets performed into a laboratory scale installation. The particularities of this
experimental stage represent the gas burner that was introduced in the facility in order to burn a liquid mixture,
giving gases with a composition similar to that obtained at the industrial scale, and also the device that sprays
water into the gas mixture as fine droplets in order to assure the necessary amount of water to reduce the electron
beam penetration depth through gas. Thus, the processes performed at large industrial combustion plants are
reproduced with a high accuracy at laboratory scale. The presence of the fine water droplets has a favorable
effect on the overall process by increasing the level of liquid phase reactions. By determining the energy
efficiency of the process the favorable effect of using fine water droplets and high-energy electron beam was
demonstrated.
116
S2 P04
SYNTHESIS OF A NOVEL POLYELECTROLYTE BY COPOLYMERIZATION OF ACRYLAMIDE
AND ACRYLIC ACID BY ELECTRON BEAM IRRADIATION
Gabriela CRACIUN, Daniel IGHIGEANU, Elena MANAILA
National Institute for Lasers, Plasma and Radiation Physics, Electron Accelerators Laboratory, #409
Atomistilor St., 077125 Magurele, Romania,
Polyelectrolytes are water-soluble polymers or copolymers carrying ionic charge along the polymer
chain. The inherent solid - liquid separating efficiency makes these polyelectrolytes a unique class of polymers
which find extensive application in potable water, industrial raw and processed water, municipal sewage
treatment, mineral processing and metallurgy, oil drilling and recovery, etc. The main goal of this study was to
investigate the influence of the absorbed irradiation dose and initiator concentration upon physical and chemical
properties of the acrylamide – acrylic acid based polyelectrolites, obtained by copolymerization in accelerated
electron beam field. The experiments were performed using a linear accelerator facility (ALIN-10, built in
NILPRP Accelerators Laboratory, Bucharest) of 6.23 MeV at irradiation doses between 0.5 kGy and 2 kGy at
room temperature and ambient pressure.
S2 P05
INFLUENCE OF ABSORBED DOZE ON CROSS-LINK DENSITY OF EPDM /TMPT RUBBER
VULCANIZED BY IRRADIATION
Elena MANAILA1, Maria Daniela STELESCU2, Gabriela CRACIUN1, Daniel IGHIGEANU1
1
National Institute for Lasers, Plasma and Radiation Physics, Electron Accelerators Laboratory, #409
Atomistilor St., 077125 Magurele, Romania,e-mail: [email protected]
2
National Research and Development Institute for Textile and Leather – Leather and Footwear Research
Institute, 93 Ion Minulescu St., Bucharest, Romania,
Elastomer crosslinking by means of electron beam (EB) is done without heating and in the absence of
vulcanization agents. The reaction mechanism is similar to crosslinking with peroxides, but in this case, reaction
initiation is due to the action of EB and in the presence of the polyfunctional monomers. Ionizing radiation
produces the excitation of polymer molecules. The energies associated with the excitation depend on the electron
beam irradiation dose. The interaction results in the formation of free radicals by molecules dissociation in the
excited state or by interaction of molecular ions. The free radicals or molecular ions can react by connecting the
polymer chains directly or initiating grafting reactions. Several researchers suggest that appropriate
polyfunctional monomers-PFMs (co-agents) in polymer matrix could be used to obtain desired rubber physical
properties at lower irradiation doses . Co-agents are multi-functional organic molecules which are highly reactive
towards free radicals . They are used as reactive additives to boost the vulcanization efficiency.
Effect of polyfunctional monomer - trimethylopropane trimethacrylate (TMPT) on the cross-link density and gel
fraction of the ethylene-propylene rubber (EPDM) vulcanized by electron beam processing was evaluated.
Dependence of gel fraction and crosslink density by irradiation dose was studied in the dose range of 100 kGy to
250 kGy. The results show that the addition of polyfunctional monomer, increase the cross-link density and gel
content comparing with the control samples.
117
S2 P06
INFLUENCE OF TRIALLYLCYANURATE ON CROSS-LINK DENSITY OF ETHYLENE-VINYLACETATE COPOLYMER VULCANIZED BY ELECTRON BEAM PROCESSING
Elena MANAILA1, Maria Daniela STELESCU2, Gabriela CRACIUN1, Daniel IGHIGEANU1
1
National Institute for Laser, Plasma and Radiation Physics, Electron Accelerators Laboratory, #409
Atomistilor St., 077125 Magurele, Romania, e-mail: [email protected]
2
National Research and Development Institute for Textile and Leather – Leather and Footwear Research
Institute, 93 Ion Minulescu St., Bucharest, Romania,
Ethylene vinyl acetate (EVA) copolymers are randomly structured polymers which offer excellent
ozone resistance, weather resistance, and excellent mechanical properties. EVA is one of the widely used
polymers as a cable insulators. But new applications have now been developed and EVA has been recognized as
an oil resistant material, which can be used for automotive applications, such as gaskets, seals, and hoses. EVA
is available as a plastic, thermoplastic elastomer or rubber material, depending on the vinyl acetate (VA) content
in the copolymer. EVA containing 28% 54 VA, is a thermoplastic elastomer and a rubber when the polymer
contains 50% VA. An important stage in the EVA processing technology is cross-linking. It consists in forming
cross-linking bridges between macromolecules, thus leading to a significant improvement of thermal and
dimensional stability of products. Since it has a fully saturated backbone, EVA does not crosslink by means of
sulfur. It has to be cured radically by means of peroxides or high-energy radiation.
In order to investigate the effect of ionizing radiation on EVA/TAC samples, the latter were subjected to
electron beam treatment with doses ranging between 50 kGy and 500 kGy. Sol-gel analysis and cross-linking
density have shown that samples tend to crosslinking after electron beam irradiation. Following the results
obtained, it was observed that increasing the irradiation dose leads to an increase in crosslinking density
118
S2 P07
NON-LINEAR COOPERATIVE DECAY PROCESS OF THREE-LEVEL SYSTEMS STIMULATED
BY THERMAL FIELD AND GENERATION OF ENTANGLED PHOTON PAIRS
Nicolae A. ENAKI, Tudor ROSCA
Institute of Applied Physics, Academy of Sciences of Moldova, Academiei str. 5, Chisinau MD 2028, Republic of
Moldova
The cooperative phenomena between the radiators in nonlinear interaction through the vacuum states are in the
center of attention in the last time. This type of generation processes of the coherent photon pairs is function of
the initiation stage of the induced emission from vacuum fluctuations. The two-photon emission depends on the
confinement of the radiators in the optical cavities like the spontaneous two-photon
emission from a solid-state single quantum emitter recently observed in the Ref. [1],
and proposed for three radiators in Ref. [2].
Combining single- and two-photon processes, this report aims to investigate new
cooperative emissions of the inverted system of radiators taking into account the
resonance between single- and two-photon cooperative transitions of three - level
atomic subsystems. In this case we replace two dipole active radiators with three level
atom in cascade- and V- configurations. The resonance appears between the inverted
relatively the single-photon transitions of the three-level radiator and the dipole
forbidden transitions of D-radiator (Hydrogen or He-like atom). These cooperative
effects between the three-level radiators occur through the vacuum fluctuations of the
electromagnetic field and can amplify the spontaneous emission rates of each atomic
subsystem. The sign of exchange integral depends on the distance between the dipole forbidden D- radiator and
the three-level atom in cascade- (or V-) configuration and has many analogies with the three particle processes
proposed in paper [2]. Comparing with Ref. [2], where it is proposed three subsystems in cooperative interaction
this report proposes the cooperative interaction between two radiator subsystems in which one of them is
inverted relative the dipole-forbidden transition. The mutual influences of two- and single-photon cooperative
processes on the two-photon cooperative emission of the inverted subsystems are examined. The increasing of
the number of entangled photons is observed in the process of single and two-photon resonances between the
subsystems. It is demonstrated that the product of two vacuum polarizations of the three-level atom comes into
resonance with the nonlinear polarization of the dipole-forbidden transitions of the D-radiator. The time-space
evolution of the two-particle correlation function is described by a closed system of differential equations.
1. Y. Ota, S. Iwamoto, N. Kumagai, and Y. Arakawa, Spontaneous two-Photon emission from a single
quantum dot Phys. Rev. Lett. 107, 233602 (2011).
2. N.A. Enaki ,Mutual cooperative effects between single- and two-photon super-fluorescent processes
through vacuum field, Eur. Phys. J. D 66: 98 (2012)
119
S2 P08
PRELIMINARY SYNTHESIS FOR TRANSPARENT 1at.% Nd-YAG CERAMICS
Catalina-Andreea VASILESCU1, Traian DASCALU1, George STANCIU1, Ruxandra BARJEGA1, Catalin
LUCULESCU1, Nicolaie PAVEL1
1
National Institute for Lasers, Plasma and Radiation Physics, 077125 Magurele-Bucharest, Romania
[email protected]
Large volume and cheap transparent ceramics doped with rare earth ions are very desirable for high
power lasers. The development of short pulse lasers and their applications fueled the research in this field,
especially for Yb and Nd doped Y3Al5O12 material which allows ceramic engineering for new laser architectures
[1-3].
Here, we report on preliminary results on transparent ceramic fabrication process prepared by solid state
reaction method or wet chemical method.
1at.% Nd-YAG nanopowders were prepared by solid-state reaction method using Al2O3, Y2O3 and
Nd2O3 powders as starting materials. The 1at.% Nd-YAG powders were moulded into thin disks using a steel die
at 10 MPa. To increase the density of the samples they were cold isostatic pressed for 5 minutes at 245 MPa.
X-ray diffraction data was performed for the green disks and also for the sintered one at different
temperatures. They show the formation of YAG solid solutions, with small amount of secondary phases when
the samples were calcined in air at 1450°C, 1500°C, 1550°C for 4 hours.
The microstructure of the ceramic samples were analyzed by scanning electron microscopy (SEM). The
SEM micrographs allow us to appreciate the homogeneous and dense microstructure.
References:
[1] G.C. Wei, J. Phys. D: Appl. Phys. 38 (2005) 3057–3065.
[2] Y. Li, S. Zhou, H. Lin, X. Hou, W. Li, H. Teng, T. Jia, J. Alloys Comp. 502 (2010) 225–
230.
[3] A. Krell, T. Hutzler, J. Kinke, J. Eur. Ceram. Soc. 29 (2009) 207–221.
120
S2 P09
QUASI-PHASE-MATCHING IN HIGH ORDER HARMONIC GENERATION IN DUAL GAS
MULTIJETS
Valer TOSA and Katalin KOVACS
National Institute for R&D Isotopic and Molecular Technologies, Cluj-Napoca, Romania
In this paper we numerically analyze the process of high-order harmonic generation (HHG) in a multi-jet
configuration. In HHG process an outer-shell electron from a (usually) noble gas atom is ionized by a high
intensity laser pulse and moves as a free particle in the oscillating laser field. If driven back to the parent ion the
kinetic energy accumulated from the laser field is emitted as a single photon. At macroscopic level the harmonic
yield depends critically on the phase matching between the single emission phase and the harmonic field phase
built previously. On phase matching the dipole contributes to the harmonic field increase, otherwise we observe
a decrease of the harmonic signal.
During propagation however, the phase mismatch is unavoidable because the phase of the single emission and
harmonic field evolve independently. The initial idea [1] was to create a multi-jet, that is a sequence of
successive gas jets separated by vacuum regions and to choose the thickness of each gas jet such that the phase
mismatch is avoided. Between the jets, the laser and harmonic fields propagate in vacuum and phase-matched
HHG can be re-established in the next jet.
0.0
0.5
1.0
H61 phase ( radians)
Fig. 1. Harmonic field intensity (solid black line) and phase
difference (blue squares), in a dual-gas multijet formed by
Ne (producing HHG) and hydrogen (totally ionized). The
jet lengths are delimitated by the electron fraction (red
dashed line) along the propagation distance. The evolution
of the intensity proves the quasi-phase-matched regime of
harmonic generation while the phase difference confirm the
mechanism.
1.5
1.0
0
-1
0.5
-2
-3
0.0
-4
-5
0.0
0.5
1.0
1.5
Propagated distance (mm)
The next improving step [2] is to use a second ionizing medium instead of vacuum so that one can control the
phase difference by adjusting the pressure of the second gas. In this way the length of the medium can be kept
fixed which is a great technical advantage. This is the case we analyse in the present work. We numerically
calculate HHG in multijets using Ne and He and Ne and H2 as dual gas pairs. The nature of gases is dictating the
occurrence of phase matching condition: a gas which easily ionize can be use to reset the phase matching
condition (see Fig. 1) while a gas with high ionization potential (He) has the advantage of not disturbing the
driving beam propagation but cannot induce the phase matching condition.
Acknowledgement Research financed through project PNII-PT-PCCA-2011-3.1-0886.
References
[1] V. Tosa, V.S. Yakovlev , F. Krausz , New Journal of Physics 10, 025016 (2008)
[2] A.Willner, et al., New Journal of Physics 13, 113001 (2011)
121
S2 P10
SINGLE ATTOSECOND PULSE GENERATION FROM COMBINED 50 FS LONG NIR AND MIR
LASER PULSES – CASE STUDY
K. KOVÁCS1, E. BALOGH2, B. MAJOR2, P. WEBER3, B. SCHÜTTE3, A. ROUZEE3, V. TOŞA1, K. VARJÚ2,
M.J.J. VRAKKING3
1
Natl. Inst. for R&D of Isotopic and Molecular Technologies, 400293 - Cluj-Napoca, Romania
2
Department of Optics and Quantum Electronics, University of Szeged, Hungary
3
Max Born Inst, D-12489 Berlin, Germany
We present a case study to show the possibility to obtain single attosecond pulse (SAP) through high-harmonic
generation (HHG) in a two-color configuration. In this case we combine a near-IR (790 nm) pulse with a mid-IR
(1300 nm) pulse, both having 50 fs duration. The experiments were performed at MBI Berlin, optimal
configurations were developed. We present here simulation results obtained with a 3D non-adiabatic model, and
analyze in detail one case considered to be near the optimum.
The main difference of this configuration compared to standard two-color HHG cases is the relatively loose
focusing of the pulses (f=50cm) together with high gas pressure (500 mbar, Ne) and long interaction region (6
mm). These circumstances together create favorable HHG conditions for: (1) extended cutoff with high photon
flux, and (2) the possibility to obtain SAP only by applying a spatial filter to keep mostly the on-axis part of the
harmonic emission.
In the case study presented here, the strong mid-IR pulse drives the HHG process assisted by a weaker near-IR
beam. A high yield and high cutoff scenario is reached when the cell is positioned before focus because we
match the conditions to have almost flat intensity profile through the whole propagation. There is a balance
between: (a) geometrical focusing which tends to increases intensity; (b) high pressure causes significant
dispersion on neutrals; (c) plasma dispersion.
The possibility of generating SAP with such long pulses is due to a combined gating effect. First, due to the
combination of 790 nm and 1300 nm pulses the elementary dipole emissions occur at 2.5 optical cycles (of 790
nm) time interval. Then, in the high pressure the pulses are distorted in a short distance of propagation such that
the emissions from only 2-3 half-cycles build up constructively. This practically means that there is a narrow
time-window within the leading edge of the combined pulses that contributes to the HHG process. Further, by
propagation in the ionized medium the “satellite” attosecond pulses are cleaned, and we end up with a bright
SAP at the exit of the HHG cell.
K. Kovács and V. Toşa acknowledge the support of the project PN-II-RU-PD-2011-3-0236.
122
S2 P11
THE INFLUENCE OF THE RASHBA SPIN-ORBIT COUPLING ON TWO-DIMENSIONAL
MAGNETOEXCITON-POLARITONS IN MICROCAVITY
S.A. MOSKALENKO1, M.A. LIBERMAN2,3, I.V. PODLESNY1, E.V. DUMANOV1, B.V. NOVIKOV4
1
Institute of Applied Physics, Chisinau, Republic of Moldova
KTH Royal Institute of Technology and Stockholm University, Stockholm, Sweden
3
Moscow Institute of Physics and Technology, Russia
4
Institute of Physics, St. Petersburg State University, St. Petersburg, Russia
2
Our results concern the electron-radiation and Coulomb electron-electron interactions in system of twodimensional (2D) electron-hole pairs on the layer embedded into the microcavity and subjected to the action of a
strong perpendicular magnetic field as well as of the electric field in the same direction giving rise to the Rashba
spin-orbit coupling (RSOC) with the third order chirality terms and with a quartic term in the nonparabolic
dispersion law of the heavy holes in the GaAs-type quantum well.
In these conditions the magnetoexciton-polariton branches have the nonmonotonous dependences on the
magnetic field strength B with intersections and strong changing of the quantum transition probabilities. The
more simple cases without polariton branches were described earlier in the Refs. [1, 2].
The Rabi frequencies which determine the spread of the polariton branches are proportional to the dipole moment
Pcv of the optical quantum transition between the valence and conduction bands, they increase as
B with the
increasing of the magnetic field and obey to the selection rule following which the numbers of the Landau quantization
levels of the electron and hole in the composition of the magnetoexciton coincide. Similar properties were revealed in
Ref. [3].
The coherent macroscopic state was introduced into the Hamiltonian following the Keldysh-Kozlov-Kopaev
method in combination with the Bogoliubov theory of the quasiaverages. The equations of motion were deduced for
the two-particle integral operators
 (Q)
and D(Q) describing the optical and acoustical plasmons
correspondingly as well as for the creation and annihilation operators
ˆ ex† (k|| ), ˆ ex (k|| ), Ck† ,k , Ck ,k
z
||
z
||
of the
magnetoexciton and photon modes in the microcavity correspondingly. Such possibility is due to the degeneracy of
the Landau levels, which in Landau gauge do not depend on the one-dimensional wave vector. It was shown that
the presence of the SOC is equivalent to take into account the influence of some excited Landau levels. It permits to
obtain following [4] the energy spectrum of the collective elementary excitations, even when the ground state of the
system is the Bose-Einstein condensation of the 2D magnetoexciton-polaritons on the lower polariton branch with
the in-plane vector
k||  0 . The calculations in this direction are continued.
References
[1] S.A .Moskalenko et al, Solid State Communications, 151, 1690–1695 (2011).
[2] I.V. Podlesny et al, Physica E, 49, 45–51 (2013).
[3] S.A. Moskalenko et al, J. Nanophoton., 6(1), 061806 (2012).
[4] S.A. Moskalenko et al, Eur. Phys. J. B, 85: 359 (2012).
S2 P12
IMPACT PARAMETERS OF THE TAC PF TRACKER SYSTEM
F. B. PİLİÇER1, İ. TAPAN1
1
Uludağ University, Physics Department, Bursa, Turkey
A silicon tracker system was designed for the Turkish Accelerator Center Particle Factory (TAC PF) detector for
effectively tracking of the relatively low momentum charged particles. The initial design of the tracking detector
consists of five individual cylindrical barrel modules and each module has two parallel single-sided silicon strip
detector planes assembled into carbon layers. In the present work, FLUKA simulation code was used to calculate
impact parameters of particle passing straight through the tracker. Impact parameters variations as a function of
the incident particles momentum and pseudo-rapidity have also been calculated for the silicon tracker system.
123
S2 P13
DIFFUSIVE REFLECTANCE SPECTROSCOPY (DRS) ANALYSIS IN PRACTICAL SCIENTIFIC
RESTORATION
Andrei HRIB1, Carmen MITA2, Dana Ortansa DOROHOI1
1
2
"Alexandru Ioan Cuza" University, Faculty of Physics
"Alexandru Ioan Cuza" University, Faculty of Chemistry
Spectral analysis of painted surfaces by diffuse reflection is an appropriate method for investigating pictorial
surfaces restored. Identification of pigments and metamerism phenomenon encountered in case of imitative
reintegration highlight the effectiveness of the method.
S2 P14
DEPOSITION OF POLYMERIC COATINGS BASED ON PCL/PLGA BLENDS: A COMPARATIVE
STUDY
G. POPESCU-PELIN1, E. AXENTE1, F. SIMA1, I. IORDACHE1, C. NITA1, A. VISAN1, I. ZGURA2, O.L.
RASOAGA2, C.S. BREAZU2, A. STANCULESCU2, G. SOCOL1, I.N. MIHAILESCU1
1
National Institute for Lasers, Plasma and Radiation Physics, Magurele, Ilfov, Romania
2
National Institute of Materials Physics, Magurele, Ilfov, Romania
The treatment of bone defects remains the major challenge of reconstructive surgery. In order to repair
the defects caused by tumors or other disease, one can improve the properties of implants surface by adding
organic or inorganic materials (polymers, bioglass).
Simple and mixtures of poly(ε-caprolactone) (PCL) and poly(lactic acid-co-glycolic acid) (PLGA) in
different ratios (1:3, 1:1, 3:1) have been deposited by matrix assisted pulsed laser evaporation (MAPLE) and dipcoating to produce thin films on titanium, glass and silicon substrates. We identify the optimum deposition
conditions with respect to the structural, morphological, and wettability properties of thin films. In the case of
MAPLE technique, PCL/PLGA composite films were deposited at different laser fluences, in the range (300500) mJ/cm2, while the withdrawal speed was varied for dip-coating. Fourier transform infrared (FTIR)
spectrometry evidenced that the chemical composition of coatings deposited by the two methods was preserved
whereas the X-ray diffraction (XRD) studies revealed the presence of diffraction peaks of PCL only. SEM
investigations exhibited a dependence of surface morphology on the chemical composition, polymeric mixture
ratio and deposition method. Depending on the polymeric mixture ratio and deposition method, wettability tests
performed on the polymeric coatings showed a either hydrophobic or hydrophilic behavior.
S2 P15
PHOTON DETECTION EFFICIENCY SIMULATION OF SILICON PHOTOMULTUPLIER
Esra YILDIRIM1, Fatma KOCAK1, Cuneyt CELIKTAS2, Ercan PILICER1
1
2
Ege University, Physics Department, İzmir, Turkey
Silicon photomultipliers have been started to consider to be replaced by conventional photomultipliers in some
applications like medical and high energy physics. In this work, the photon detection mechanism has been
simulated for a silicon photomultiplier structure by using Single Particle Monte Carlo Technique written in C++
within Root framework. The photon detection efficiency of the silicon photomultiplier have been investigated at
a constant operating voltage. The simulation results give good agreement with the photon detection efficiency
given in the literature.
124
S2 P16
VARIABLE GEOMETRY DIRECT CURRENT REACTOR USED FOR PLASMA
POLYMERIZATION
V. BARNA1, V. COVLEA1, B. BUTOI1, CRISTINA BEREZOVSKI1, D. STAICU1, R. BEREZOVSKI1, A. M.
MARIN2
1
University of Bucharest, Faculty of Physics, PO Box Mg-11, 077125, Bucharest, Romania
University of Medicine and Pharmacy “Carol Davila”, No. 8 Eroilor Sanitari Blvd., Bucharest, Romania
2
Plasma polymerization is a valuable and wide used tool for processing thin and very thin polymeric
films [1-3]. We report the realization of a new DC reactor with variable geometry used for plasma
polymerization. The reactor has a cylindrical shape with a changeable distance between electrodes of 1-20 cm.
The anode is situated in the upper side of the reactor, while the cathode is located in its bottom part. The shape of
the cathode is of a circular disk with a central hole through which the substrate enters in the core of the reactor.
The distance for which the substrate enters inside the space between electrodes is also variable. The angle
between the substrate surface and the direction of the electric field may vary between 0 and 90 o. Figure 1 shows
a schematic representation of the reflex discharge reactor.
We found that modifying the position and angle of the substrate, the topology of the film significantly
changes, from almost perfect smooth surfaces to spatially grown structures.
The monomer is injected inside the reactor
from above, through a hole situated in the center of the
anode. The mechanism of the monomer injection
consists in controlled evaporation together with direct
plasma injection. The plasma parameters were 10-2-1
torr and DC voltage of 400-1500V. The plasma was
investigated using optical spectra fitted with custom
made software [4], in order to determine the electrons
and ions temperature.
For testing our device, we performed polymer
DC plasma deposition using aniline and pyrrole as
monomers. The samples were studied by SEM, FTIR
and AFM.
Fig.1. Schematic representation of
the DC plasma reactor
1. H.Yasuda, "Plasma Polymerization", Academic Press, London, UK, 1985.
2. M. A. Lieberman, A. J. Lichetenberg, "Principles of Plasma Discharges and Materials Processing",
John Wiley, New York, 1994
3. A. Grill, "Cold Plasma in Materials Fabrication-From Fundamentals to Applications", IEEE Press,
New York, 1994
4. M. Bazavan, I. Iova, Rom. Rep. Phys. 60, 671 (2008)
125
S2 P17
MULTI-COMPONENT CARBIDE PROTECTIVE COATINGS FOR TRIBOLOGICAL
APPLICATION
Alina VLADESCU, Mihai BALACEANU, Viorel BRAIC, Anca PARAU, Iulian PANA, Mariana BRAIC
National Institute for Optoelectronics-INOE 2000, 409 Atomistilor Str., Magurele, Romania
Based on the principle of high-entropy alloys, comprising at least five principal metallic elements, each
of its content is over 5 at%, and there is no dominant element, multi-component nitride or carbide coatings have
received increasingly interest due to their unique combination of structural, mechanical and wear-corrosionoxidation resistant characteristics. They were found to exhibit nanocrystalline solid solutions or amorphous
phases and to possess high hardness and toughness, good thermal stability, low compressive stress, smooth
surface, compact microstructures, superior resistance to wear, corrosion and oxidation. For the present study,
three types of multi-component carbide coatings were investigated: (HfNbTaTiZr)C, (CuSiTiYZr)C and
(CrCuNbTiY)C. The coatings were deposited on different substrates by co-sputtering of pure metallic targets in
an Ar + CH4 reactive atmosphere, using an ATC ORION magnetron unit. The mass flow ratio of the working
gases was set at different values for obtaining stoichiometric and overstoichiometric coatings. Coatings were
characterized in terms of elemental and phase composition, chemical bonds, morphology, residual stress,
hardness, and adhesion. The tribological behaviour of the coatings in dry conditions was also investigated.
All the investigated coatings exhibit FCC solid solution structures, with (111) preferred orientations.
The presence of the amorphous carbon phases was observed in all the overstoichiometric coatings. The
overstoichiometric coatings presented the best tribological performances, with friction coefficients lower than
0.15 and wear rates in the domain (0.8 – 1.9) *10-6 mm3N-1m-1.
The development of multi-component carbide coatings would provide a benchmark to develop new
materials with unique properties, which would be impossible to attain based on only one dominant element.
Acknowledgements: Work supported by Romanian National Authority for Scientific Research, CNCS –
UEFISCDI, Project PN-II-ID-PCE-2011-3-1016.
126
S2 P18
SOLID SOLUTION OR AMORPHOUS PHASE FORMATION IN TiZr-BASED TERNARY TO
QUINTERNARY MULTI-COMPONENT FILMS
Alina VLADESCU, Nicolae Catalin ZOITA, Mihai BALACEANU, Viorel BRAIC, Mariana BRAIC
National Institute for Optoelectronics-INOE 2000, 409 Atomistilor Str., Magurele, Romania
TiZr-based multi-component metallic films composed of 3 to 5 constituents with almost equal atomic
concentrations were prepared by co-sputtering of pure metallic targets in an Ar atmosphere. For the specific
elements (Ti, Zr, Hf, Nb, Al, Cu, Cr,Y and Si) taken in different combinations, under the deposition conditions
chosen for the present study (deposition temperature – 3000C, negative substrate bias – 100 V), only solid
solutions (fcc, bcc, hcp) or amorphous phases were obtained, no intermetallic compounds being detected by Xray diffraction. It was found that certain elements can be used to tune the microstructure of the multi-component
metallic films: the hcp structure is stabilized by either Hf or Y, bcc by Nb or Al, fcc by Cu, while Si facilities
amorphous phase formation.
An analysis of the thermodynamical and atomic size factors which can control the phase formation was
performed. Based on the Miedema’s approach of the regular solution model, mixing enthalpy, mixing entropy,
Gibbs free energy of mixing and electronegativity difference for the formation of solid solution or amorphous
phases in TiZr-based multi-principal-element metallic films were determined.
For the investigated films, it was experimentally demonstrated that amorphous phases formed when the
atomic size difference (quantified by the  parameter) exceeded a certain value ). Except for the TiZrSi
film, it was found for the amorphous films that both the values of the Gibbs free energy and enthalpy of mixing
of the amorphous phase were lower than the corresponding values related to the solid solution phase. As a rough
approximation, highly negative chemical enthalpies and high electronegativity differences are indicative of
amorphous phase formation.
The atomic size difference of the constituent elements and the relationship between the Gibbs free
energy of mixing of solid solution and amorphous phases are proposed as criteria for predicting phase formation
in multicomponent metallic films.
Acknowledgements: Work supported by Romanian National Authority for Scientific Research, CNCS
– UEFISCDI, Project PN-II-ID-PCE-2011-3-1016.
S2 P19
EMISSIVE PROBE FOR HOT PLASMAS
Bernd S. SCHNEIDER, Roman SCHRITTWIESER,
Codrina IONITA, Stefan COSTEA, Franz MEHLMANN, Johannes GRÜNWALD
Association EURATOM/ÖAW, Innsbruck Experimental Plasma Physics Group, Institute for Ion Physics
and Applied Physics, University of Innsbruck, Austria
For plasma diagnostics electrical probes have the advantage of measuring the most important plasma
parameters directly at the position of the probe with the spatial resolution determined just by the probe size and
the probe drive. In particular, emissive probes show the tendency to display the plasma potential directly with the
additional benefit of higher time resolution than conventional cold probes.
A prototype of an emissive probe for hot plasmas has been developed and will be presented. Using an
electrically heated LaB6 rod of 1,5 mm diameter as probe pin, the goal is to design a probe able to penetrate
deeper into hot, dense plasmas than earlier designs. LaB6 has a low work function and high thermal resistance.
The rod has a length of 10 mm and is heated in the lower part by dc on a length of 3 mm.
Test results and probe characteristics obtained in the low temperature plasma of Innsbruck’s DP-machine
(Double Plasma machine) will be illustrated. In detail, a comparison with a cold Langmuir probe current-voltage
(I-V) characteristic using the inflection point method is carried out. We want to demonstrate that with sufficient
heating of the probe pin the emissive probe’s floating potential is capable to reach the actual plasma potential in
the DP machine plasma. Also a closer look on the probe’s temperature and resistivity behaviour is considered.
The further outlook is to enhance the probe design to make it suitable for use in hot plasma devices like
tokamaks or stellarators and promoting it as an easy tool for plasma diagnostics.
127
S2 P20
SYNTHESIS AND CHARACTERIZATION OF La3Ga5.5Ta0.5O14 DOPED WITH HOLMIUM AND
YTTERBIUM
Ana-Maria VOICULESCU1, Serban GEORGESCU1, Cristina MATEI1,2, Angela STEFAN1,2, Octavian TOMA1
1
National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Street, Magurele, Ilfov, 077125,
Romania, [email protected]
2
University of Bucharest, Faculty of Physics, 405 Atomistilor Street, 077125, Magurele-Ilfov, Romania
The La3Ga5.5Ta0.5O14 ceramic samples doped with holmium and ytterbium (1 at% and 3 at%,
respectively) was synthesized by solid-state reaction. Stoichiometric quantities of high purity oxides (La 2O3,
Ga2O3, Tm2O3, Yb2O3, Ta2O5) were mixed in an agate mortar, pressed with a hydraulic press at 2.5 MPa and
then annealed in air at 1350ᵒC for 35h. The phase purity of LGT:Er:Yb was analyzed by X ray diffraction.
Besides the diffraction lines of LGT phase, some other lines, but with very low intensities, were observed. The
‘‘extralines’’ belong to perovskite LaGaO3 (*) and β-Ga2O3 (ᵒ)phases (Fig.1).
Fig. 1. XRD patterns of LGT:Yb:Ho.
Fig. 2. Luminescence spectrum of LGT:Yb:Ho
excited at 488nm.
The sample was characterized by optical spectroscopy (luminescence, absorption, decay
measurements). The luminescence of the samples was excited in blue (at 488 nm), with the Argon laser. The
experimental set-up for measurements in UV-vis domain contains a Horiba Jobin-Yvon monochromator (model
1000MP), an S-20 photomultiplier and the SR830 lock-in amplifier on line with a computer. For IR
luminescence, the Horiba Jobin-Yvon monochromator was replaced by a 1 m Jarrell Ash monochromator with a
thermoelectrically cooled InGaAs photodiode. For decay measurements (of the Ho 3+ levels (5S2, 5F4) and 5I6 for
Yb3+ ) the luminescence was excited with the Quantel Rainbow OPO. All the measurements were performed at
room temperature.
The luminescence spectrum of Ho3+ in LGT:Yb:Ho in IR (700 – 1600 nm) domains, is given in Fig. 2.
The observed transitions are: 5S2→5I7, 5F5→5I6, 5I6→5I8, 5S2→5I5, 5I5→5I7. The effect of the energy transfer
processes between Ho3+ and Yb3+ in LGT on the emission properties in visible and IR of Ho3+ and Yb3+ is
studied.
Ackowledgments This work was supported by the Romanian Executive Agency for Higher Education,
Research, Development and Innovation Funding (UEFISCDI), in the frame of the Projects IDEI 82/06.10.2011.
128
Section 3 – NUCLEAR AND SUB-NUCLEAR PHYSICS AND APPLICATIONS
SECTION
S3 – Nuclear and sub-Nuclear Physics and Applications
Nuclear and subnuclear sciences and Engineering
Advanced detection systems
Accelerated particle beams
Nuclear Techniques and applications
Nuclear Safety and Radiation Protection
129
INVITED LECTURES
S3 L01
THE MANY FACETS OF THE (NON-RELATIVISTIC) NUCLEAR EQUATION OF STATE
GIANLUCA GIULIANI1,2, H. ZHENG2, A. BONASERA2,3
(1) Department of Physics and Astronomy University of Catania, Catania, Italy
(2)Cyclotron Institute, Texas A&M University, College Station TX, USA
(3)INFN Laboratori Nazionali del Sud, Catania, Italy
The knowledge of the Nuclear Equation Of State (NEOS) [1] is crucial to understand the properties of nuclear
systems at different densities, far from the ground state one 0=0.l6 fm-3, and temperatures; the study of the
composition and evolution of neutron stars [2] is a well known case of a nuclear system undergoing critical
conditions. On the other hand, experiments performed in terrestrial laboratories, concerning Heavy Ion
Collisions (HIC) in the Fermi energy domain, still provide constraints on the parameters and on the density
dependence of the NEOS [3]..
The aim of this oral presentation will be to discuss the recent progresses regarding the NEOS studies.
The first section will start with the introduction of the NEOS at zero temperature. Particular interest will be
devoted to the asymmetric nuclear matter case and, consequently, on the definition of the symmetry energy S(ρ)
and the quantities L(ρ)≈∂S/∂ρ and Ksym(ρ)≈∂2S/∂ρ2 [4]. Such quantities play a role in constraining the density
dependence of S(ρ) and to determine the strength of S(ρ) at 0 density, the so-called symmetry term; at present
there is no universal consensus on their values. The momentum dependence of the NEOS will be also discussed.
Since nucleons are not elementary particles [5], most experimental data require a non-local potential. Momentum
dependent interactions have been successfully proposed in order to reproduce low excitation energy phenomena
such as giant resonances. For the asymmetric nuclear matter case, the momentum dependence also affects the
symmetry energy by introducing the difference in the Fermi energy momenta of protons and neutrons when their
densities are different. At the end of this section some features related to the NEOS at finite temperatures will be
highlighted [3].
The second section will be related to the test of the NEOS parameterizations suggested in [1] for the following
cases:
1.Neutron Stars
2.Finite nuclei in their ground states: Neutron Skin Thickness (NST) and density dependence of the symmetry
energy [278-280]
3.Nuclear collective modes: Isovector Giant Dipole Resonances (IVGDR)
The last two cases have been addressed by exploiting dynamical and transport models such as the Constrained
Molecular Dynamics (CoMD) [6] model and the Boltzmann-Nordheim-Vlasov (BNV) transport model [7]. The
IVGDR study by means of the BNV model has been performed by following very well known calculations
found in the literature [8]. On the other hand, NST calculations by means of the CoMD model represent a novel
approach to such topic. Furthermore, the Isobaric Analog States (IAS) method to extract the symmetry term
will be also presented [9].
The last section will briefly address the constraints to the NEOS from HIC. It will be shown how is possible, by
studying fragmentation reactions, to extract the symmetry energy within the framework of the Landau's theory of
phase transitions [10].
New features for nuclear matter and nuclei, concerning their descriptions not only as strongly interacting
Fermionic systems (made of neutrons and protons) but also as mixtures of Bosons (alpha particles, deuterons,....)
and Fermions, will be suggested.
References:
1.
G. Giuliani, H. Zheng, A. Bonasera, Prog. In Part. And Nucl. Phys. 76 (2014) 116-164
and refs. Therein
2.
A. W. Steiner, J. M. Lattimer and E. F. Brown, The Astr. Journ., 722:33-54 (2010) and refs. Therein
3.
B. A. Li, L.-W. Chen, C. M. Ko, Phys. Rep. 464 (2008) 113-281 and refs. Therein
4.
V. Baran, M. Colonna, M. Di Toro, V. Greco, Phys. Rep. 410 (2005) 335 and refs therein
5.
R. B. Wiringa, V. G. J. Stoks, R. Schiavilla, Phys. Rev. C 81 (1995) 38.
6.
M. Papa, T. Maruyama, A. Bonasera, Phys. Rev. C 64 024612 (2001)
7.
A. Bonasera, F. Gulminelli, J. Molitoris, Phys. Rep. 243 (1994) 1-124
8.
V. Baran, B. Frecus, M. Colonna, M. Di Toro, Phys. Rev. C 85 051601(R) (2012); V. Baran, M. Colonna, M. Di Toro, A.
Croitoru and D. Dumitru, Phys. Rev. C 88 044610 (2013)
9.
P. Danielewicz, J. Lee, Nucl. Phys. A 922 (2014) 1
10.
H. Zheng, A. Bonasera, Phys. Rev. C 86 (2012) 027602; H. Zheng, G. Giuliani, A. Bonasera, Nucl. Phys. A 892 (2012) 43; H.
Zheng, G. Giuliani, A. Bonasera Phys. Rev. C 88 024607 (2013); H. Zheng, G. Giuliani, A. Bonasera Journ. Of Phys. G: Nucl. Part. Phys.
41 (2014) 055109
130
S3 L02
ASYMMETRY ENERGY OF NUCLEAR MATTER: TEMPERATURE AND DENSITY
DEPENDENCE, AND VALIDITY OF SEMI-EMPIRICAL FORMULA
G. H. BORDBAR,1,2 R. FERIDOONNEZHAD,1 M. TAGHIZADE1
1
Physics Department, Shiraz University, Shiraz 71454, Iran
Center for Excellence in Astronomy and Astrophysics (CEAA-RIAAM)-Maragha, P.O. Box 55134-441,
Maragha 55177-36698, Iran
2
Nuclear matter is an extremely large hypothetical system of constrained nucleons which interact through the
strong nuclear force. It can be considered as an ideal model for the nuclear matter within the heavy nuclei. The
nuclear matter asymmetry energy is an important subject in nuclear physics and astrophysics. It plays a central
role in the investigation of heavy-ion collisions, stellar collapse, supernova explosions, neutron stars, etc. In this
work, we have calculated the binding energy of asymmetric nuclear matter using a many-body variational
method based on the cluster expansion of energy at finite temperature. In our calculations, we have employed the
nuclear potential. This potential is written in an operator format which depends on the value of J, L, S, T
and of nucleon-nucleon pair. Therefore, in the calculations with this potential, the third component of isospin
( ) should be explicitly considered. This is a very important point in the calculations for asymmetrical nuclear
matter consisting of Z protons and N neutrons, where in general
. There are only few microscopic studies
on asymmetric nuclear matter. The calculations of asymmetric nuclear matter binding energy have been mainly
done using a parabolic approximation. Therefore, it is interesting to study the validity of this estimation for the
binding energy of nuclear matter at different proton to neutron ratios. Here, we have done a completely
microscopic calculation to compute the asymmetry energy of nuclear matter. We have also investigated the
temperature and density dependence of asymmetry energy. Our results show that the asymmetry energy of
nuclear matter depends on density and temperature. We have also studied the effects of different terms in the
asymmetry energy of nuclear matter. These investigations indicate that at different densities and temperatures,
the contribution of parabolic term is very substantial with respect to the other terms. Therefore, we can conclude
that the parabolic approximation is a relatively good estimation, and our calculated binding energy of
asymmetric nuclear matter is in a relatively good agreement with that of semi-empirical mass formula. However,
for the accurate calculations, it is better to consider the effects of other terms.
S3 L03
ISOSPIN AND MASS DEPENDENCE OF DIPOLE RESPONSE IN NEUTRON-RICH NUCLEI
V. BARAN1, M. COLONNA2, M. DI TORO2, A. CROITORU1
1
Physics Faculty, University of Bucharest, RO-77125 Bucharest, Romania
2
Laboratori Nazionali del Sud, INFN, Catania, Italy
We explore the dipole response of atomic nuclei within a transport model based on a system of two coupled
Vlasov equations. These equations describe the dynamics of one-body distribution function for protons and
neutrons and can be obtained as the semiclassical limit of Wigner tranformation of Time Dependent HartreeFock (TDHF) equations. From numerical simulations we conclude that the polarizability follows a mass
dependence consistent with the Migdal predictions, but with a slope which is influenced by the density
dependence of the symmetry energy around saturation. We also estimate the energy weighted dipole sum-rule
exhausted by Pygmy Dipole Resonance for an isotopic chain of Sn and we find a quadratic evolution with
isospin parameter of the system. These features may have relevance from experimental point of view, since
future measurements, for example at ELI-NP, can determine for various isotopic chains, the dipole strength with
high accuracy. We consider these results as being linked to the polarization effects of the isovector density which
manifest in finite systems.
131
S3 L04
ELI-NP: NEW OPPORTUNITIES FOR NUCLEAR ASTROPHYSICS
O. TESILEANU, N.V. ZAMFIR
Extreme Light Infrastructure – Nuclear Physics, ”Horia Hulubei” National Institute for Physics and Nuclear
Engineering (IFIN-HH), 30 Reactorului St, 077125 Magurele (Ilfov), Romania
The study of nuclear reactions of astrophysical interest by using very intense gamma radiation beams is one of
the scientific fields where ELI-NP promises to break new ground with its capabilities beyond the present day
state-of-the-art. For the study of key reactions such as 12C(α,γ) or 24
e p-process nucleosynthesis,
three charged particle detectors were proposed by the international community: an array of silicon strip
detectors, an electronic-readout time projection chamber (eTPC), and a bubble chamber. These have
complementary capabilities for some reactions, and together cover the needs of the detection of charged particles
in experiments using the gamma beam at ELI-NP. An overview of the proposed scientific cases as well as the
relevant experimental setups proposed will be given.
132
ORAL PRESENTATIONS
S3 OP1
SYSTEMATICS OF THE α-DECAY FINE STRUCTURE IN EVEN-EVEN NUCLEI
D. S. DELION1,2,3, A. DUMITRESCU1,4
1
”Horia Hulubei” National Institute of Physics and Nuclear Engineering, 407 Atomiștilor, POB MG-6,
Bucharest-Măgurele, RO-077125, România
2
Academy of Romanian Scientists, 54 Splaiul Independentei, Bucharest, RO-050094, România 3Bioterra
University, 81 Gârlei str., Bucharest, RO-013724, România
4
Department of Physics, University of Bucharest, 405 Atomiștilor, POB MG-11, Bucharest-Măgurele, RO077125, România
We describe α-decay transitions to low-lying states in even-even nuclei with Z > 50, N > 82 by using the
Coherent State Model (CSM). We reproduce the energies and electromagnetic transitions of the ground state
band by using two parameters, namely the deformation parameter and the strength of the harmonic CSM
Hamiltonian. The B(E2) values are described in terms of an effective charge which depends linearly on the
deformation parameter. The α-emission process is described by using an α-daughter interaction containing a
monopole component, estimated within a double folding procedure with M3Y interaction plus a repulsive core
simulating the Pauli principle, and a quadrupole-quadrupole (QQ) interaction. The decaying states are identified
with the lowest narrow outgoing resonances obtained within the coupled channels method. The α-branching
ratios to 2+ states were reproduced by using the QQ strength. This interaction strength can be fitted by a linear
dependence versus the deformation parameter, as predicted by CSM. The theoretical intensities to 4+ and 6+
states are in a reasonable agreement with available experimental data. This work was supported by a grant of the
Romanian Ministry of Education and Research, CNCS - UEFISCDI, project number PN-II-ID-PCE-2011-30092. We thank Professors Z.Z. Ren (Nanjing) and F.R. Xu (Beijing) for valuable discussions during our
cooperation in the Kavli Institute for Theoretical Physics, China
S3 OP2
ENERGY DEPENDENCE OF NECK FRAGMENTATION REACTION MECHANISM
M.MARCIU1 , V.BARAN1
1
Physics Faculty, University of Bucharest, RO-77125 Bucharest, Romania
In this presentation we shall discuss new features of the fragmentation dynamics at the transition from
semicentral to semiperipheral heavy-ion collisions at Fermi energies. Our results are obtained within a
microscopic transport model, stochastic mean field (SMF). We show new results of the numerical simulations
for the collisions of nuclear systems Sn124+Ni64 and Xe124+Zn64 at two beam energies, 35 AMeV and 45 AMeV
respectively, considered also experimentally by CHIMERA experiment. We analyze various kinematical features
and investigate the possible correlations between the time scales of fragmentation mechanism and the dynamics
of isospin degree of freedom by employing two different parameterizations with density of symmetry energy
133
S3 OP3
ISOVECTOR PROTON-NEUTRON PAIRING AND WIGNER ENERGY IN HARTREE-FOCK
MEAN FIELD CALCULATIONS
D. NEGREA and N. SANDULESCU
National Institute of Physics and Nuclear Engineering,
P.O. Box MG-6, 76900 Bucharest-Magurele, Romania
We propose a new approach for the treatment of isovector pairing in self-consistent mean field calculations
which conserves exactly the isospin and the particle number in the pairing channel. The mean field is generated
by a Skyrme-HF functional while the isovector pairing correlations are described in terms of quartets formed by
two neutrons and two protons coupled to the total isospin T=0. In this framework we analyse the contribution of
isovector pairing to the symmetry and Wigner energies. It is shown that the isovector pairing is able to provide a
good description of the Wigner energy, which is not the case for the mean field calculations in which the
isovector pairing is treated by BCS-like models
S3 OP4
DISTRIBUTION OF Ca AND K RADIOACTIVE ISOTOPES IN DOBROGEA COUNTY SOIL
Daniel ENACHE, Marius BELC, I.M.OANCEA-STANESCU
Heavy metal pollution is a problem associated with areas of intensive industrial activity. The soil bio-monitoring
technique was employed in this work to study the atmospheric deposition in Dobrogea County Romania together
with complementary nuclear and atomic analytical methods: Neutron Activation Analysis (INAA), Atomic
Absorption Spectrometry (AAS), Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) and
Particle Induced X-Ray Excitation (PIXE). These high sensitivity analysis methods were used to determine the
elemental composition of some samples of soil placed in different vision areas with different pollution industrial
sources. The design of a monitoring programs was involve: sampling locations, sample collection, heavy metals
to be analyzed, multi-element determination using INAA(Neutron Activation Analysis), AAS (Atomic
Absorption Spectrometry), ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometry) and Particle
Induced X-Ray Excitation (PIXE) techniques and data analysis.
Keywords: INAA, AAS, ICP-AES, elemental composition
134
POSTERS
S3 P01
HIGH ENERGY (MEV) ION BEAM IMPLANTATION IN INT-WS2
Mihai STRATICIUC1, Alla ZAK2, Doru Gheorghe PACESILA3, Victor Alexandru RUNCEANU3, Adrian Ionut
ROTARU3, Ion BURDUCEA1, Dan Gabriel GHITA3, Petru Mihai RACOLTA1
(1) Applied Nuclear Physics Department, Horia Hulubei National
Institute of Physics and Nuclear Engineering (IFIN-HH), 30 Reactorului St., Magurele Ilfov 077125,
Romania
(2) Department of Science, Holon Institute of Technology,
Golomb St. 52, Holon 58102, Israel
(3) Tandem Accelerators Department, Horia Hulubei National Institute of Physics and Nuclear Engineering
(IFIN-HH), 30 Reactorului St., Magurele Ilfov 077125, Romania
Niobium ions implantation was performed on tungsten disulfide inorganic nanotubes powder (INT-WS2)
synthesized in a fluidized bed reactor (FBR). A dose of 10 15 ions/cm2 and different beam energies, between 1
MeV and 15 MeV, were delivered by using a 3 MV HVEE Tandetron accelerator recently installed at IFIN-HH,
in Romania. In order to determine the modifications induced by the ion beam irradiation in the INT-WS2 pellets,
various nuclear and atomic techniques were applied: Rutherford Backscattering Spectrometry (RBS), Particle
Induced X-ray Emission (PIXE) and Transmission Electron Microscopy (TEM).
S3 P02
OPTIMIZATION OF THE GEOMETRICAL DETECTION EFFICIENCY OF THE CBM-TRD
STATIONS
L.RADULESCU, M.PETRIS, M.PETROVICI, V.SIMION
“Horia Hulubei” National Institute of Physics and Nuclear Engineering,
Bucharest-Magurele, Romania
This paper presents the optimization of the Transition Radiation Detector (TRD) geometry of the CBM
experiment at FAIR, from the point of view of the active area, relative to the total area of the TRD subdetector.
The TRD wall consists from three stations. The first and the second one will comprise four TRD layers
and the last one two layers. Due to the different configurations of CBM experiment for the SIS100 and SIS300
accelerators, both, the stations configuration and the position of the stations relative to the target should be
flexible. Therefore, the presented method optimize the TRD chambers dimensions for each station and the
position along the beam line, in order to get a high geometrical detection efficiency, matching the dead zones of
the TRD chambers frames among different layers.
135
S3 P03
THICKNESS EVALUATION OF DOPED BIFEO3 THIN FILMS USING DIFFERENT TECHNIQUES
Ion BURDUCEA1, Mihai Straticiuc1, Dan Gabriel GHITA1, Petru Mihai RACOLTA1, Ecaterina TENEA2,
Mariuca GARTNER2, Victor FRUTH2
(1)
Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN HH, 30 Reactorului St., Magurele
077125, Romania
(2)
Institute of Physical Chemistry, 202 Splaiul Independentei St., Bucharest 060021, Romania
BiFeO3 (BFO) thin films have become attractive nanostructures because of their potential applications in a new
generation of multifunctional devices. Strontium doped and pure BFO thin layers were deposited on silicon and
microscope glass slide substrates using liquid precursors and dip coating technique. In order to have a more
complete characterization of the obtained materials and their quality along with conventional techniques nuclear
methods were also used. Structural and morphological observations were realized by means of XRD and SEM
investigation. The thicknesses of the deposited layers were evaluated by spectro-ellipsometry (SE) and
Rutherford Backscattering Spectrometry (RBS) techniques. RBS measurements were done at the new 3MV
Tandetron accelerator available at Horia Hulubei National Institute of Physics and Nuclear Engineering (IFINHH). The results revealed a good correlation between values obtained with different evaluation techniques.
S3 P04
THE 1MV COCKCROFT-WALTON TANDETRON ACCELERATOR DEDICATED TO
ACCELERATOR MASS SPECTROMETRY (AMS) - 14C DATING
Oana GAZA1,2, Corina Anca SIMION1, Tiberiu Bogdan SAVA1, Dan Gabriel GHITA1, Doru Gheorghe
PACESILA1, Ionut-Catalin CALINESCU1, Alexandru Marian VASILIU1, Horia IOVU2
1
Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN- HH Bucharest), 30
Reactorului St., Magurele, jud. Ilfov, P.O.B. MG-6, RO-077125, ROMANIA
2
University “POLITEHNICA” of Bucharest, Faculty of Applied Chemistry and Materials Science, 149 Calea
Victoriei St., Bucharest, 010072, ROMANIA
The machine was commissioned to measure C, Be, Al and I isotopic ratios with an accuracy of 10 -15.
Performing analysis with such accuracy opens the possibility for applications in various domains such as: carbon
dating of artefacts, material research, geology, determination of erosion rates, detection of existing nuclear
pollution, forensic science and nuclear activity surveillance, diagnose of fusion experiments, astrophysics and
oceanography, biomedical, pharmacological applications, and many more.
This sensitivity is equivalent with the possibility to select and count one single type of atom from one
million of billions of other types of atoms. This is the reason why Accelerator Mass Spectrometry (AMS) has
been developed to perform analyses at highest sensitivities, able to detect radio-isotopes concentrations where
other methods fail.
Towards the development of a National Dating Program in Romania, a 14C dating laboratory was
commissioned in 2012 at IFIN-HH Bucharest. Our activity at this moment is mainly focused on radiocarbon
dating of organic samples, especially bones.
The standard procedure for measuring an organic sample using AMS technique consists in extracting
and graphitization of the collagen, following a very complex sequence of chemical transformations from bone to
graphite. The two main stages of the preparation are pretreatment stage, in which the organic material is
extracted from the bone and the graphitization stage, in which the extracted material is transformed to graphite
that is inserted in a matrix of iron powder through a reduction process of the CO 2 obtained from the combustion
of the organic sample. The whole process is done using a fully automated graphitization unit.
Work is in progress to improve the classical pretreatment methods by using a High Pressure Liquid
Chromatography system for the separation and identification of individual fractions of amino acids from raw
collagen. This fractionate dating technique is a very useful verification tool for cross checking the dating results
and is also a more reliable source of information.
As future activities we intend to develop new sample preparation methods, in order to enlarge our
capabilities regarding the various types of materials that are going to be dated.
136
S3 P05
CHALENGES OF GAMMA-RAY ASSAY DURING DECOMMISISONING
Daniela GURAU1
1
Horia Hulubei national Institute for Physics and Nuclear Engineering, POB MG-6, RO-077125, Magurele,
Romania
In the decommissioning process are resulted a lot of radioactive materials that need to be radiological
characterized. Some of these materials could be evacuated from the controlled area, other can be released under
the authorization and other can be treated as a radioactive waste following to be disposed. The most detailed
analysis of the gamma emitting radionuclides can be obtained using gamma-ray spectrometry. The requirement
for short data collection time or the measurement of containers with materials with a low or very low level of
radioactivity often means putting the detector as close as possible to the container. When the detector is
positioned close to a large item containing radioactive material, the coincidence summing corrections need to be
taken into account.
In the country and worldwide, many studies have been carried out to assess the coincidence summing
corrections, being a problem of major interest in gamma-ray spectrometry measurements. In the case of a nuclide
decaying through a cascade of successive photon emissions measured close to a high efficiency detector,
coincidence-summing effects can be important. These effects take place when there is a non-negligible chance
that two or more than two photons originating from the same decay process hit simultaneously the detector,
contributing together to the detector signal. The coincidence-summing effects depend in a complex way on the
decay scheme of the nuclide, on the sample geometry and composition, on the detector efficiency and on the
distribution and scattering properties of the materials surrounding the sample and the detector (Debertin and
Helmer, 1988; Arnold and Sima, 2000; Sima and Arnold, 2000; Sima et al.,2001; Arnold and Sima, 2001;
Arnold and Sima, 2004; Debertin and Schotzig, 1979).
The ISOCART method for gamma-ray assay is a versatile instrument in its ability to measure a wide
range of containers including large containers and objects that can only be measured in situ. The ISOTOPIC
software includes an algorithm to correct the presence of true coincidence summing effects in spectral data. A
“TCC” check box in the analysis settings enables the feature and ISOTOPIC algorithms will apply the correction
factors to the results. Because these factors cannot be seen in the report analysis and the Monte Carlo simulation
of a large container (Gurau and Sima, 2012) will necessitate a large amount of time (for describing the
measurement geometry: the detector, the container, absorbers, materials, etc.) and powerful calculations, analysis
will be made using different algorithms. Based on the differences of results obtained with the normal analysis
procedure and with the different algorithm, the coincidence summing correction factors will be evaluated.
References
1. Debertin, K., Helmer, R.G., North-Holland, Amsterdam (1988)
2. Arnold, D., Sima, O., Appl. Rad. Isot. 52 (2000) 725-732
3. Sima, O., Arnold, D., Appl. Rad. Isot. 53 (2000) 51-56
4. Sima, O., Arnold, D., Dovlete, C., J. Radioanal. Nucl. Chem. 248 (2001) 359-364
5. Arnold, D., Sima, O., Appl. Rad. Isot. 61 (2004) 117-121
6. Debertin, K., Schotzig, U., Nucl. Instr. Meth. Phys. Res. 158 (1979) 471-477
7. Gurau, D., Sima, O., Appl. Rad. Isot. 70 (2012) 305-308
8. Gurau, D., Sima., O., Rom. Rep. Phys. 64 (2012)
137
S3 P06
GEANT4 SIMULATION OF A PROTOTYPE DETECTOR FOR MUONS RADIOGRAPHY
Valerica BABAN(1), Dănuţ ARGINTARU(1), Jipa ALEXANDRU(2), Eliodor CONSTANTINESCU(1)
(1)
Constanţa Maritime University , (2) Bucharest University Faculty of Physics
Cosmic rays are energetic particles originating outside of our solar system that constantly bombards the
Earth’s atmosphere. A fraction of these particles penetrates the Earth’s surface at high relativistic velocities. The
primary particles, usually highly energetic protons decays in a secondary particles resulting showers of other
particles and radiation. Most of these particles are pions . Pions are short lived and usually decays too. For
examples the charged pions decays into charged muons (π+ → µ+ + νµ , π - → µ - + ν ) and the neutral ones
decay into gamma rays , which may convert into electrons and positrons. Because cosmic muons produced in
these showers have speed close to the speed of light they have a longer life time than other particles resulting in
these showers. This is the reason that muons represent a 80% of the radiation that reaches the sea level [1] . In
the current work we use the Geant 4 toolkit [2] to simulate the muons interaction with a plastic scintillators and
to define a basic model of a detector module for testing propose . Our goal is to build a portable and
inexpensive detector for muons radiography that can be used as a non-destructive method to scan various
structures using the flux of muons coming from outer space.
[1] Particle Data Group , http://pdg.lbl.gov/2013/reviews/rpp2013-rev-cosmic-rays.pdf
[2] Geant4 is a toolkit for the simulation of the passage of particles through matter, http://geant4.cern.ch/
S3 P07
MEASUREMENT OF STRANGE PARTICLE CORRELATIONS IN PP COLLISIONS
Catalin HANGA
…………….
…………………...
138
S3 P08
THE USE OF MICRO-PIXE IN TRANSYLVANIAN NATIVE GOLD CHARACTERIZATION
B. CONSTANTINESCU1, DANIELA CRISTEA-STAN1, D. CECCATO2, L. PICHON3,
Q. LEMASSON3, Claire PACHECO3
1
Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering, Magurele, Romania
2
Universita di Padova, and INFN, LNL, I-35020 Legnaro (Padova), Italy
3
CRRMF, Palais du Louvre, 75001 Paris, France
Small samples (hundreds of microns) of native gold from Rosia Montana and from Cavnic were scanned by
micro-PIXE to obtain information on presence of Au and Ag minerals (Te and Sb compounds) – many as microinclusions and on other characteristic elements as Hg. Rosia Montana is one of the oldest and most interesting
gold deposit with both veins and stockworks. Cavnic deposit is located in the eastern part of the Carpathian belt,
one of Europe’s major metallogenic provinces. Analyzed samples are from recovery obtained by inhabitants
from landfills of former mining plants. Micro-PIXE analyses were performed at LNL AN2000 accelerator from
Legnaro and at AGLAE Louvre Accelerator in Paris. On Rosia Montana samples we detected micrometric areas
(5m X 5m) rich in Ag and Sb and without Au, Sb/Ag ratio being 1/5-6, indicating the presence of stephanite Ag5SbS4. In one sample we detected the micro-presence of mercury, suggesting Hg could be used as a
“fingerprint” for Rosia Montana gold deposit. On Cavnic-Roata samples, to investigate Au and Ag minerals, we
analyzed areas of approx. 50 microns diameter. One micro-area revealed an important presence of Te (16657
ppm), a significant presence of Sb (2861 ppm) and an increase of Ag content (Ag=32.75% versus Au =50.05%),
indicating the presence of a Ag telluride containing also Sb. The high As content (6.64%) could indicate
benleonardite - Ag8(Sb,As)Te2S3 highlighted in Kremnica, Slovakia. A comparison with a micro-mineralogical
study using a SEM (Scanning Electron Microscope) associated with EDX (Energy-dispersive X-ray
spectroscopy) facility is presented. Some cassiterite (Sn oxide) micro-grains extracted from Valea Pianului
alluvial gold samples were also analyzed and traces of Zr, Nb, Ta, W were identified.
139
S3 P09
SOME APPLICATIONS OF MICRO-PIXE IN THE STUDY OF ANCIENT BRONZE, SILVER AND
OBSIDIAN ARTIFACTS
Daniela CRISTEA-STAN1, B. CONSTANTINESCU1, D. CECCATO2
1
Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering, Magurele, Romania
2
Universita di Padova, and INFN, LNL, I-35020 Legnaro (Padova), Italy
A study concerning the copper provenance of some Bronze Age items (axes, sickles, daggers, swords, celts)
found on Romanian territory was performed at AN2000 accelerator in Legnaro. The problem consists in their
classification from the Bronze Age regional mines point of view – North-East Bulgaria [Ai Bunar –
“fingerprints” minor-trace elements As (up to 2-3%), Ni and Sb (hundreds of ppm)], Serbia [Rudna Glava and
Majdanpek – “fingerprints” trace elements As, Sb, Ni, Ag, Se (thousands-hundreds ppm)] or Transylvania (e.g.
Baia-Mare – “fingerprints” trace elements Sb and Ag – thousands of ppm). We analyzed 15 very small samples
(less than 500 microns diameter) from different archaeological sites in south Romania – especially axes and
sickles. The majority presents relevant traces of arsenic and antimony, suggesting the use of copper from north
Bulgaria.
For silver items, we performed a study on some Silver (drachms) issued between V and III Century BC by
Greek colony Histria – situated on Romanian Black Sea coast and on Dacian silver imitations of Greek silver
tetradrachms to detect trace elements which can be used as fingerprints for Silver provenance (e.g. bismuth for
South-Balkans deposits, antimony for Carpathian deposits, gold, lead) and to determine copper content which is
an indicator of the metallurgical procedure - copper was used to increase the mechanical properties of silver.
We also used micro-PIXE to study some Neolithic micro-tools (blades) found in Romania to determine the
obsidian provenance: Tokay Mts. (Hungary, Slovakia), Melos (Greek islands), Lipari, etc. Micro-blades found in
Magura - an important Early Neolithic site from Teleorman county, Muntenia, approx. 100 km South-Vest of
Bucharest – were analyzed. To identify the obsidian sources we used the group Rb-Sr-Y-Zr, a “pattern” specific
for each source as illustrated in PIXE spectra. Our results suggest for Magura Early Neolithic – Crish Starcevo
culture (6200 – 5200 BC) samples some Aegean sources, obsidian arriving from Macedonia crossing the
Balkans.
Our studies demonstrated that micro-PIXE is a good analytical tool to investigate the composition of ancient
artefacts in order to determine their provenance, especially the geological sources of metals and obsidian.
S3 P10
USE OF LITHIUM NITRATE AS A POTENTIALLY CORROSION INHIBITOR FOR RADIOACTIVE
ALUMINIUM IN CEMENTING SYSTEMS
M. NICU, L. IONASCU, C. TURCANU, F. DRAGOLICI
“Horia Hulubei” National Institute of Physics and Nuclear Engineering, P.O. Box MG-6, RO-077125 Magurele,
Romania
The safe conditioning process of radioactive metallic aluminium generated during the decommissioning of
VVR-S Research Nuclear Reactor, Magurele, is imposed by National regulations, before final disposal at BaitaBihor repository. To respect waste acceptance criteria (WAC) for disposal, the matrix must be stable in time
from chemical, physical, mechanic and geometric point of view.
Generally, the most common matrix is based on cementing systems which develop in the hydration and
setting steps a pore solution with a pH higher than the passivation (4.5 ÷ 8.5) domain for metallic aluminium. To
decrease the chemical attack of metal in the alkaline medium, the protection of aluminium can be accomplished
by passivation, coating or inhibition.
The management of metallic radioactive waste impose the simplest processing, so passivation or coating can be
difficult to realize, the inhibition being much easier by direct addition of the inhibition reagent directly in the
cementing system. This research is focused on the use of lithium nitrate in the conditioning of radioactive
aluminium, to minimize the alkaline corrosion and to improve the performances of the final radioactive waste
package. The selected conditioning systems for characterization were CEM III-A, CEM V-A and magnesium
phosphate binders.
140
S3 P11
EFFECT OF HEAVY IONS TO THE SILICON DETECTORS
ADNAN KILIÇ1
1
Silicon particle detectors are used in several applications such as accelerators in high energy physics, space,
nuclear physics experiments and medicine. Thereby, it is crucially important to understand the effect of various
particles with different energies on performance of silicon detectors. In this study, we have investigated spectra
of secondary particles generated by different particles types in the silicon detectors with common dimensions by
GEANT4 and FLUKA tools. Also, we have done some studies using SRIM/TRIM (Stopping and Range of Ions
in Matter) software to estimate the effect of secondary heavy ions produced by the incident particles to silicon
detectors.
S3 P12
ENERGY DEPOSITION STUDIES FOR CRYSTALS USED IN MEDICAL APPLICATIONS
Nazli ERDINIZ1, Adnan KILIC1, Fatma Belgin PILICER1, Ercan PILICER1
1
Inorganic crystals are used to detect gamma rays from positron annihilation process in human body. Some of the
widely used scintillating crystals like BGO, LSO, GSO, NaI(Tl) are of interests in medical applications. In this
work, the energy deposition in these crystals were investigated and compared by using extensively used Geant4
and Fluka Monte Carlo Carlo simulation programs. The scintillation light generated in the crystal is proportional
to the energy deposition due to the radiation sources. The intensity of these light, as well as other parameters, is
important for medical imaging. Additionally, we examined longitudinal and lateral shower developments in each
crystals in order to estimate and optimize crystal dimensions.
S3 P13
NEUTRON DEGRADATION OF SEVERAL POLYMERS SUBJECTED TO IBR-2 RADIATION AT
DUBNA
Eduard Marius LUNGULESCU1, Radu SETNESCU1,2, Tanța SETNESCU2, Mădălina MARINESCU1, Otilia
CULICOV1,3, Sergey KULIKOV3
1
National Institute for R&D in Electrical Engineering, Department of Advanced Materials. Splaiul Unirii 313,
Sector 3 Bucharest, 030138, Romania
2
Valahia University of Targoviste, Faculty of Sciences and Arts, Department of Sciences and Advanced
Technologies, Bd. Unirii 18 - 24, Targoviste, 130024,Romania
3
Joint Institute for Nuclear Research (JINR) Dubna, 141980 Dubna, Moscow region, Russia
The degradation effect of different doses of nuclear reactor radiations on different polymeric materials low density polyethylene (LDPE), high density polyethylene (HDPE) and polystyrene (PS) has been assessed by
DSC and FTIR. The changes in different physical or chemical transitions observed in DSC, such as glass
transition (Tg), melting temperature and oxidation [either as oxidation induction temperature (OOT) or oxidation
induction time (OIT)] are discussed in function of both the dose (in the range of 0 to 80 kGy) and the absorbance
of different FTIR bands related to radiation induced degradation. Durability evaluation, based on oxidation
induction parameters, of the studied materials in the reactor radiation field are also presented.
S3 P14
RIVET PLUG-IN FOR
141
PRODUCTION CROSS-SECTION MEASUREMENT IN pp
COLLISIONS AT
s = 7 TeV
DUMITRIU Ana Elena, A. T. GRECU
Horia Hulubei National Institute of Physics and Nuclear Engineering,
Reactorului 30, RO-077125, Bucharest-Magurele, Romania
The Rivet project (Robust Independent Validation of Experiment and Theory) is an efficient and portable toolkit
in form of C++ class library enabling validation of Monte Carlo (MC) event generator models and tunings in
elementary particle physics and astrophysics. It provides a large collection of standard experimental analyses
useful for MC generator development, validation, tuning and regression testing proposing a new way by which
analysis code from the LHC and other high-energy collider experiments is preserved for comparison and
development of future theory models.
The results of the Rivet plug-in developed for the LHCb measurement of Z e+e- production crosssection in pp collisions at 7 TeV center-of-mass energy [1], are presented for a few selected tunes in the detector
fiducial pseudo-rapidity range 2<η<4.5. The cross section is determined at a value of
 ( pp  Z  e  e  )  76.0  0.8(stat)  2.0(syst)  2.6(lumi)pb .
Its single differential distributions
are given as function of Z rapidity and an angular variable which is closely related to Z transverse momentum.
References
[1] “Measurement of the cross-section for
J. High Energy Phys. 02 (2013) 106.
production in pp collisions at
s = 7 TeV”, LHCb Collab.,
S3 P15
ENHANCING SAFETY AND RADIATION PROTECTION IN TRANSPORT OF RADIOACTIVE
MATERIAL IN ROMANIA
Gheorghe VIERU,
ARWN/ c,o Institute For Nuclear Research, Pitesti, Romania
The transport of Dangerous Goods-Class #7 Radioactive Material (RAM), according to the UN classification is
an important part of the Radioactive Material Management.
The overall aim of this activity is for enhancing operational safety and radiation protection measures during the
transport of the radioactive materials, in order to ensure the protection of the people and the environment.
The paper will present an overall of the safety and radiation protection measures recommended and
implemented during transportation of Radioactive Material in Romania. Some aspects on the potential threat on
environment will be also approached with special referring to the low level radioactive material (waste) and
NORM transportation either by road or by rail. A special attention will be given to the assessment and evaluation
of the possible radiological consequences due to the potential threats over shipments by using available computer
codes such as INTERTRAN 2 and RADTRAN 6.
The analyze will emphasize the importance and responsibility for establishing and sustaining effective leadership
in the management of safety and rasiation protection measures for transport of RAM.
The paper is a part of the IAEA’s Vienna Scientific Research Contract on the State Management of Nuclear
Security Regime (Framework) concluded with the Institute for Nuclear Research, Romania, where the author is
the CSI (Chief Scientific Investigator).
142
S3 P16
THE NEW SECONDARY EXTENSION PROTON BEAM LINE AND THE DESIGN OF THE LOCAL
SHIELDING FOR TR-19 CYCLOTRON IN IFIN-HH
L. S. CRACIUN1*, R. G. RATA2, A. T. SERBAN1, C. IONESCU1, D. NICULAE1
1
2
Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), Romania
International Institute for Accelerator Applications West Building, University of Huddersfield Queensgate,
Huddersfield, GB
*Corresponding Author e-mail: [email protected]
IFIN-HH installed the TR19 Cyclotron dedicated to both research of short-lived radioisotopes and nuclear
physics research activities, in 2012. The accelerator was designed, custom-built and tested for IFIN-HH by
Advanced Cyclotron System Inc. (ACSI), in Richmond, Canada. The dual beam construction of the cyclotron
allowed equipping the machine with a specifically conceived 6 m long external beam line, ending in a separate
bunker (the experimental hall). Recently was installed The Secondary Beam Line that will allow for a second
pathway to conduct the variable energy proton beam from the cyclotron to allow the attachment of a single target
or a multiple target changer. The Secondary Beam Line was
designed to be mounted underneath the existing beam line. It
was constructed to connect to the existing TR-19 combination
switching magnet. At the end of the Secondary beam line a
solid target or a target station can be accommodate.
During the target bombardment, the high intensity prompt
neutron/gamma radiation fields are produced. The target
shield should protect the surrounding equipment, floors and
walls from appreciable neutron fluxes from the target. On the
other hand experience has shown the need for access to the
target position. The shield should therefore consist of
Fig. 1 TR19 cyclotron with two beam lines on one
materials that produce predominately short lived
side of the machine. The top beam line is used for
radioactivity and it should provide high absorption of the
nuclear physics research activities in the second
residual radiations. The volume and cost of the shield are
bunker. The bottom beam line houses a solid
also important factors.
target station designed to accept up to 300 uA of
This report summarizes the results of the Monte Carlo
proton beam. Additional shielding around the solid
simulation performed in order to study the neutron and
target station attenuates the higher radiation fields
photon ambient dose equivalents around the target selector
from this target.
at the end of the secondary proton beam line. The goal of
this calculus is to estimate the local shielding around the
irradiated solid target in order to reduce the radiation dose outside of the bunker.
The suggested designs for target shields and beam stops discussed here include some extrapolations, they
demonstrate the feasibility of such devices for reducing the residual radiation levels by a few orders of
magnitude.
References:
[1] Facure A., França W. “Optimal shielding design for bunkers of compact cyclotrons used in the production of
medical radionuclides”, Med. Phys. 37 (1) 6332-6337, December 2010
[2] Facure A “Monte Carlo Simulation of TR 1 9shielding (Bucharest project), Advanced Cyclotron System Inc.,
Richmond, Canada, May 2011
143
S3 P17
DETERMINATION OF THEORETICAL GAMMA-RAY ATTENUATION COEFFICIENTS OF
DIFFERENT ABSORBER MATERIALS BY USING CdTe DETECTOR
E. E. ERMIS1, C.CELIKTAS1 and E. PILICER2
1
Ege University, Faculty of Science, Physics Department, 35100, Bornova, Izmir, TURKEY
Uludag University, Faculty of Arts and Science, Physics Department, 16059, Gorukle, Bursa, TURKEY
2
The theoretical gamma-ray linear and the mass attenuation coefficients of water, plexiglass and bakelite
materials were calculated by using CdTe detector. For this purpose, FLUKA Monte Carlo (MC) method and
XCOM program were used. Obtained attenuation coefficients from both theoretical methods were compared
with each other and the literature values.
Keywords: Gamma-ray attenuation coefficient, FLUKA MC method, CdTe detector.
S3 P18
BORON EQUIVALENT DETERMINATION IN NUCLEAR GRADE GRAPHITE
Anişoara SCARLAT1, Carmen ŢUCĂ1, Ana PANTELICĂ2, Mitică DRĂGUŞIN1, Ioan IORGA1,
Adrian ZORLIU1
Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN-HH),
30 Reactorului St., Magurele, Ilfov county, P.O.B. MG-6, 077125, Romania
1
Department of Reactor Decommissioning (DDR)
2
Department of Nuclear Physics (DFN)
Graphite is used in nuclear technology due to its neutron moderator and reflector qualities, combined
with high temperature stability and its structural strength. In order to be used as moderator of neutrons, graphite
must be of high purity (nuclear grade graphite), with very low level of neutrons absorbing impurities. The
elements of interest are those with the highest thermal neutron-capture cross section, such as Gd, Sm, Eu, Cd,
Dy, and B. Over time, the presence of boron in graphite appeared as a problem of large interest because of its
high neutrons capture cross section (767 barn).
To be considered as nuclear grade graphite, according to the imposed requirements in the Nuclear
Safeguards Regulations, the boron equivalent content of all impurities should be less or equal with 5 mg·kg -1
(parts per million), and the material density should be greater than 1.5 g·cm-3. Equivalent boron content is
calculated as a sum of the elemental mass fractions multiplied by factors containing thermal neutron cross
section and atomic mass values for each element relative to boron [1].
This paper presents the assessment of the boron equivalent content in graphite material stored in the
warehouse of IFIN-HH VVR-S reactor, based on analytical results obtained in our institute by INAA
(Instrumental Neutron Activation Analysis), PIXE (Proton Induced X-ray Emission), PIGE (Proton Induced
Gamma Emission), and AMS (Accelerator Mass Spectrometry). A total 43 elements were determined, as
follows: Au, Ag, As, Ba, Br, Ca, Cd, Ce, Co, Cr, Cs, Cu, Eu, Fe, Hf, Hg, K, La, Lu, Mo, Na, Ni, Rb, Sb, Sm, Sc,
Sr, Ta, Tb, Th, Zn, Zr, Yb, U, and W (35 elements) by INAA [2]; Al, Si, P, S, Cl, V, and Mn (7 elements) by
PIXE and PIGE (besides K, Ca, Cr, Fe, Ni, Cu, and Zn) [3]; B (0.26 g·kg-1) by AMS [4]. Boron equivalent
content in the investigated graphite material was found to be lower than 5 mg·kg -1 confirming its classification as
nuclear grade graphite.
[1] NGN-02 (Lista detaliata a materialelor, dispozitivelor, echipamentelor si informatiilor pertinente pentru
proliferarea armelor nucleare si a altor dispozitive nucleare explozive), HG 916/22.08.2002, MO nr.
687/18.09.2002 (in Romanian).
[2] Ana Pantelică, Anişoara Scarlat, Mitică Drăguşin, Determination of trace elements in graphite by
Instrumental Neutron Activation Analysis (this conference).
[3] Ana Pantelică, Dan Gabriel Ghiță, Doru Păceşilă, Paul Ionescu, Anişoara Scarlat, Mitică Drăguşin, PIXE and
PIGE analysis of nuclear graphite (to be published).
[4] C. Stan-Sion, M. Enachescu, A. Petre, C. Calinescu, AMS measurements of boron trace levels in graphite
(sent to Analytical Methods).
144
S3 P19
DETERMINATION OF TRACE ELEMENTS IN GRAPHITE BY INSTRUMENTAL
NEUTRON ACTIVATION ANALYSIS
Ana PANTELICĂ1, Anişoara SCARLAT2, Mitică DRĂGUŞIN2
1
2
Within the decommissioning activity of the VVR-S nuclear reactor of IFIN-HH, Magurele, besides the
radioactive waste materials produced over the course of forty years of operation (from 1957 until 1997) there are
some unused/clean materials that have to be investigated in accordance with specific decommissioning
procedures. In this respect, elemental impurities in graphite bricks from the reactor warehouse have to be
determined for its classification as nuclear-grade graphite, a material of nuclear interest subjected to nuclear
safeguards requirements.
Analytical results obtained by Instrumental Neutron Activation Analysis (INAA) for trace elements in
unirradiated graphite samples from the VVR-S reactor warehouse are presented in this paper. Neutron irradiation
of samples (mass of about 130 mg each) and appropriate standards was carried out at the TRIGA reactor of the
Institute for Nuclear Research (ICN) Pitesti, at a neutron fluence rate of 1·10 17 m-2·s-1. Gamma-ray spectra were
measured in the GamaSpec laboratory of IFIH-HH, after decay/cooling times of 3, 5, 18, and 48-51 d. The
spectrometric chain was based on HPGe Ortec detector of 2.3 keV FWHM at 1332.5 keV of 60Co and 30%
relative efficiency.
The following elements were determined in the investigated graphite samples (medium and long halflife radionuclides with T1/2>12 h): Au, Ag, As, Ba, Br, Ca, Cd, Ce, Co, Cr, Cs, Cu, Eu, Fe, Hf, Hg, K, La, Lu,
Mo, Na, Ni, Rb, Sb, Sm, Sc, Sr, Ta, Tb, Th, Zn, Zr, Yb, U, and W (a total 35 elements). Their concentrations
were found to be situated between 3 g·kg-1 for Lu and 190 mg·kg-1 for Fe, corresponding to a high purity
graphite.
S3 P20
PIXE AND PIGE ANALYSIS OF NUCLEAR GRAPHITE
Ana PANTELICĂ1, Dan Gabriel GHITA1, Doru PACESILA1, Paul IONESCU1, Anişoara SCARLAT2,
Mitică DRĂGUŞIN2
1
2
This paper presents application of Ion Beam Analysis (IBA) techniques on graphite samples (thick
targets) at the 3 MV Tandetron of IFIN-HH, using a 3 MeV proton beam. PIXE (Proton Induced X-ray
Emission), PIGE (Proton Induced Gamma Emission), and RBS (Rutherford Backscattering Spectrometry)
characteristic X-, gamma-, and particle spectra, respectively, were simultaneously registered together with
information on the proton beam charge on the target.
The elements determined by PIXE in the graphite samples investigated were Al, Si, P, S, Cl, K, Ca, V,
Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Rb, and Sr. In addition, PIGE was able to determine Na, besides Al, Cr, Mn, and
Fe in the samples. Gupix program was used for a quantitative analysis by PIXE. Some of the results obtained by
IBA techniques (Na, K, Ca, Cr, Fe, Ni, Cu, Zn, As, Se, Rb, and Sr) could be compared with those determined by
Instrumental Neutron Activation Analysis (INAA) in this graphite material [1].
Analytical information obtained by nuclear techniques for graphite samples provided by the Department
of Reactor Decommissioning (DDR) in IFIN-HH is of great importance to classify it as nuclear grade graphite.
145
S3 P21
A RETROSPECTIVE STUDY OF UTERIN AREA HIGH DOSE RATE BRACHYTHERAPY
PLANNED USING CATHETER RECONSTRUCTION
Lucia Elena ENCIU (1)
(1) University of Bucharest, Faculty of Physics;
Intracavitary brachytherapy technique is practiced for treating different forms of cancer of uterin area , either
alone or in combination with external beam radiotherapy. High dose rate brachytherapy treatment planning often
involves optimization methods to calculate dwell position and dwell times of the radioactive source along
specified afterloading catheters. ion The purpose of this study is to compare the dose distribution and the dose
obtained to organs of risk from the first application to the second application. This is a retospective study of 50
patients high dose rate brachytherapy planned using catheter reconstruction and geometric optimization and
treated with a dose of 5 Gy to 7.5 Gy per fraction. Dose obtained to organs of risk was analyzed and we obtained
better results in the second application, witch could means that we have the local control of the tumor.
S3 P22
ATOMIC METHODS APPLIED IN THE MATERIAL CHARACTERIZATION
Madalina IVANESCU1, Marius BELC2, Ion V. POPESCU3
1
Bucharest University, Romania
3
Valahia University of Targoviste, Romania
2
The atomic methods, X-ray diffraction (XRD), electron microscopy (EM and atomic force microscopy
AFM), X-ray fluorescence (XRF, PIXE) and Atomic Absorption Spectrometry (AAS) are used primarily in
analysis of the structure and composition of special materials: powder, organic or inorganic, natural or synthetic,
crystalline or amorphous and nanomaterials. Complementary methods with atomic techniques for analyzing
atomic structure, the classical methods to optimize processes and improve physicochemical properties of these
materials.
This paper describes the experimental method of structure analysis by electron microscopy (EM) of some
special materials.
146
Section 4 – CROSS-DISCIPLINARY APPLICATIONS OF PHYSICS
SECTION
S4 – Cross-Disciplinary Applications of Physics
Nonlinear dynamics, complex systems and applications
Biological complexity and genetics, Biophysics and bioengineering
Econophysics
Physics of Social Systems
147
INVITED LECTURES
S4 L01
CONTROLLING BEC PROPERTIES VIA DISORDER AND DRIVING
Antun BALAŽ
Scientific Computing Laboratory, Institute of Physics Belgrade, Serbia
Email: [email protected]
The control of Bose-Einstein condensates (BEC) properties can be achieved using different experimental
protocols. In this talk we will explore prospects of control via anisotropic disorder and driving of the trap.
We will investigate the effects of a weak anisotropic disorder at zero temperature on properties of a
homogeneous dipolar BEC [1]. We will present analytic results for the disorder ensemble averages of both the
condensate and the superfluid depletion, the equation of state and the sound velocity. For a dipolar BEC with
anisotropic disorder, we will find that the physical observables exhibit anisotropies due to the formation of
fragmented condensates in the local minima of the disorder potential.
We will also study the emergence of Faraday (density) waves in a binary non-miscible BEC due to a modulation
of the trap [2]. We will show that the excited waves are of similar periods, emerge simultaneously, and do not
impact the dynamics of the bulk. We will derive analytically their spatial periods and analyze the behavior of the
system driven at resonant modulation frequencies, which turns the two components miscible.
Finally, we will investigate Faraday waves in single-component BECs with spatially inhomogeneous interactions
[3]. In the regime of weak inhomogeneity, we will show that the properties of generated Faraday waves are very
similar to the case of homogeneous interactions, while in the strong inhomogeneity regime the periods of density
waves strongly depend on the typical length scale of the inhomogeneity.
[1] B. Nikolić, A. Balaž, and A. Pelster, Phys. Rev. A 88, 013624 (2013).
[2] A. Balaž and A. I. Nicolin, Phys. Rev. A 85, 023613 (2012).
[3] A. Balaž, R. Paun, A. I. Nicolin, S. Balasubramanian, and R. Ramaswamy, Phys. Rev. A 89, 023609 (2014).
148
S4 L02
A NOVEL SCALING FOR HUMAN TRAVEL
I. PAPP1, L. VARGA1,G. TOTH2, A. KOVÁCS3, Z. KOVÁCS-KRAUSZ1 and Z.NÉDA1,3
1
Babeș-Bolyai University, Department of Physics, Cluj-Napoca, Romania
2
Hungarian Central Statistical Office, Budapest, Hungary
3
Edutus College, Department of International Business, Tatabánya, Hungary
Human travel exhibits many fascinating universalities [1-3]. Here a novel scaling law connecting the length of a
trip (d) and the necessary travel time (t) is revealed by experiments and it is explained through a simple networkmodel. We show that the scaling is universally valid for many different traveling modes: terrestrial, air, or even
virtual ones. The scaling exponent determined from the controlled experiments is not universal however. In
order to understand this fascinating and seemingly universal feature of human travel, a simple network model is
considered. The model deals with a random undirected graph at criticality, embedded in a two-dimensional
Euclidean space. Edges of this network are the transportation channels, while nodes are the centers (cities, hubs,
airports, etc..). Between each two node of the graph, a direct link (edge) is created with a probability that
depends on the size of the involved nodes and the Euclidean distance between them. The size distribution of the
nodes is taken as the entropy maximizing distribution, although the existence of the scaling law is not
conditioned by this assumption. To construct the graph, we start from a completely disconnected graph and add
edges consecutively, respecting their probabilities until the percolation thrshold is reached. On the created
network we assume that transport between any two nodes is realized on the shortest distance taken along the
existing edges (distance on the graph). We study the relation between the Euclidean distance and the distance on
the graph as a function of the number of nodes, parameters of the nodes size-distribution function and the linear
size of the embedding two-dimensional Euclidean plane. The model successfully reproduces the experimentally
observed scaling law. As a practically important application we determine the distance versus time scaling for
virus-spreading and comment on many important consequences.
Acknowledgement: This research was supported in the framework of TAMOP 4.2.4. A/2-11-1-2012-0001
“National Excellence Program - Elaborating and operating an inland student and researcher personal support
system” project. The project was subsidized by the European Union and the State of Hungary. We thank Tamas
Dusek for data provided on air transportation.
[l] A. Noulas, S. Scellato,R. Lambiotte , M. Pontil, and C. Mascolo, Plos One 7, e37027 (2012).
[2] F. Simini, A. Maritan and Z. Neda, Plos One 8, e60069 (2013).
[3] L. Bettencourt, G. West, Nature 467, 912 (2010).
S4 L03
DENSITY WAVES IN DIPOLAR BOSE-EINSTEIN CONDENSATES
Alexandru I. NICOLIN
“Horia Hulubei” National Institute for Physics and Nuclear Engineering, Department of Computational Physics
and Information Technologies, 30 Reactorului, Magurele-Bucharest, 077125, Romania
Density waves in cigar-shaped dipolar Bose-Einstein condensates are analysed by numerical and variational
means and we show analytically how the dipole-dipole interaction between the atoms generates a roton-maxon
excitation spectrum. A simple model is used to derive the effective equations which describe the emergence of
the density waves.
[1.] A.I. Nicolin, Proc. Rom. Acad. - Series A 14, 35 (2013)
149
S4 L04
COHERENCE-BASED METHOD TO DETECT TIME SHIFTS BELOW THE SAMPLING
THRESHOLD OF TIME SERIES
E.I. SCARLAT
University Politehnica Bucharest, Applied Sciences - Physics Dept., [email protected]
Detecting of time shifts among processes evidenced by synchronously sampled quantities in the form of time
series is of ultimate importance to predicting the evolution of economic and financial phenomena, to measuring
propagation delays, or to disclose deterministic relationships or correlations between seemingly disparate
phenomena. Generally, the classical cross correlation methods allow for the detection of temporal shifts that are
multiple of the sampling rate. Unlike the general case, this paper proposes a method that can estimate time shifts
smaller than the sampling rate. Prediction below the sampling threshold is useful for economic forecasting of
macro-economic indicators before they become publicly available – the case of "bridge" and "factor" models for
gross domestic product (GDP) estimates –, or in the case of speculative trades on the stock exchange market,
where every trader tries to anticipate the competitors’ sell/buy actions by looking for the logical fingerprint of
their decision taking – the case of chaotic models with missing states in the phase space, subsequently filled in
by using interpolation or filtering procedures [1]. Moreover, the method is suitable for the estimation of distinct
time shifts in separate frequency bands, allowing for the disentangling of long-term analysis of business cycles
from the short-term speculative transactions as prerequisites for clustering techniques [2].
Here the method is based on exploiting both the modulus and the phase of the complex cross coherence function.
The measure of the time shift – if any – is given by the dependence on frequency of the phase shift provided that
the existence of significant coherence coefficients and the statistical significances are fulfilled [3].
The paper is presenting the theoretical justification of the technique, a bootstrap analysis using aggregate series,
and the calibration procedure. Finally, the method is
applied to analyze the series of exchange rates as well as of
macro-economic indicators. The exchange rates were
acquired from the site Forex Trading and Exchange Rates
Services and correspond to the interval 1 Jan. 1999-31
Dec. 2013 (18 series, 5479 points each). The quarterly
economic indicators were acquired from Eurostat database
and correspond to the interval 1 Jan. 2000-31 Dec. 2013
(23 series, 56 points each).
The presence of relevant time shifts was seldom found
ROL/USD and ROL/EUR time series; the
among the exchange rates. The picture is richer in the case
beginning of the financial shock in Aug. 2007 is
of quarterly GDP, where distinct bands were found in
marked with vertical line
several cases. The influence of the August 2007 financial
shock is discussed [4].
References
[1] C. Foroni, M. Marcellino, A survey of econometric
methods for mixed frequency data, Norge Bank Research, ISSN 1502-8143, ISBN 978-82-7553-723-0,
2013.
[2] E.A. Maharaj, P. D’Urso, Physica A, 389, 3516-3537, 2010.
[3] E.I. Scarlat, Rom. Journ. Phys. 59 Nos. 3-4, 382–396, 2014.
[4] E.I. Scarlat, UPB Sci. Bul. A, 76 (4), inprint, 2014.
150
ORAL PRESENTATIONS
S4 OP1
MONTE CARLO SIMULATIONS FOR TRANSPORT MODELING USING FRACTIONAL
EXCLUSION STATISTICS
G. A. NEMNES1,2 and D. V. ANGHEL1
1
Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH),
P.O. Box MG-6, 077126 Magurele, Ilfov, Romania
2
University of Bucharest, Faculty of Physics, ''Materials and Devices for Electronics and Optoelectronics''
Research Center, 077125 Magurele-Ilfov, Romania
The fractional exclusion statistics (FES) was introduced by Haldane [1] as a generalization of Pauli
exclusion principle and the thermodynamic properties were subsequently calculated by Wu [2] and Isakov [3]. In
this framework, systems of fermions or bosons with interactions are described as ideal FES gases.
The transition rates for homogeneous FES systems were calculated in Ref. [4] and Monte Carlo
simulations were employed to describe the dynamics of FES systems. Upon equilibration, the thermodynamic
quantities were extracted.
In Refs. [5,6,7] the species were redefined to include classical degrees of freedom, such as positions.
The approach was applied on model systems of fermions with screened Coulomb interactions.
Here we take a step further and calculate the transition rates for an inhomogeneous system, where the
species are position dependent. This approach is suitable to describe transport in FES systems. Using Monte
Carlo simulations we analyze the transport of fermions with screened Coulomb interactions in two terminal
device. Our approach is suitable for device modeling, making use of a local description of the quantum electron
gas in terms of ideal FES gas.
[1] F.D.M. Haldane, Phys. Rev. Lett. 67, 937 (1991).
[2] Y.-S. Wu, Phys. Rev. Lett. 73, 922 (1994).
[3] S.B. Isakov, Phys. Rev. Lett. 73, 2150 (1994).
[4] G.A. Nemnes and D.V. Anghel, J. Stat. Mech. 2010, P09011 (2010).
[5] G.A. Nemnes and D.V. Anghel, J. Phys.: Conf. Ser. 410, 012120 (2013).
[6] D.V. Anghel, G.A. Nemnes, and F. Gulminelli, Phys. Rev. E 88, 042150 (2013).
[7] G. A. Nemnes and D. V. Anghel, Rom. Rep. Phys. 66, 336 (2014).
151
S4 OP2
OPTICAL PROCEDURE FOR ESTIMATING YEAST CONCENTRATION IN AQUEOUS
SUSPENSION BY FAR FIELD SPECKLE SIZE MEASUREMENT
Dan CHICEA1,2
1- Department of Environmental Sciences, Lucian Blaga University, Dr. Ion Ratiu str., no 5-7, Sibiu, 550012,
ROMANIA
2 - Pediatric Respiratory Medicine Research Center (CCMRP), Str. Pompeiu Onofreiu Nr. 2 – 4 , Sibiu,
ROMANIA
A coherent light scattering experiment on aqueous suspension of Saccharomyces cerevisia yeast with a
concentration that covers five orders of magnitude was performed. The scattered far field was recorded using a
CCD. A computer code for image processing was used to calculate the far interference field speckle size (SPS).
The figure below presents the variation of the average SPS with the yeast concentration. Examining the figure
we notice that the average SPS variation with the concentration in monotone for yeast concentration bigger than
1 g/l, which is in the range of yeast concentration at the beginning of controlled beverage fermentation, as grape
juice. This suggests a very fast procedure for monitoring the yeast concentration, hence for monitoring the
fermentation process in aqueous solution, by assessing the variation of the yeast concentration during
fermentation.
Sps
9.00E+00
8.00E+00
Sps
7.00E+00
6.00E+00
5.00E+00
4.00E+00
3.00E+00
0.00E+00
2.00E+00
4.00E+00
6.00E+00
8.00E+00
1.00E+01
1.20E+01
c, g/l
References
1. Kurtzman C.P., Fell J.W., Yeast Systematics and Phylogeny—Implications of Molecular Identification
Methods for Studies in Ecology, in Biodiversity and Ecophysiology of Yeasts, The Yeast Handbook, Edited
by C. Rosa & G. Péter, Springer-Verlag, 11-30, 2006.
2. Chicea D., Speckle Size, Intensity and Contrast Measurement Application in Micron-Size Particle
Concentration Assessment, European Physical Journal Applied Physics 2007, 40, 305-310, doi:
10.1051/epjap:2007163.
3. High Alcohol Wine Production from Grape Juice Concentrates, Am. J. Enol. Vitic. 52(4), 345-351, 2001.
152
POSTERS
S4 P01
SYNTHETIC ANABOLIC STEROIDS BINDING TO THE HUMAN ANDROGEN RECEPTOR
Alecu Aurel CIORSAC1, Iuliana POPESCU2, Adriana ISVORAN3
Department of Physical Education and Sport, Politehnica University of Timi șoara, 2 P-ta Victoriei, 300306
Timisoara, Romania
2
Faculty of Agriculture, University of Agricultural Sciences and Veterinary Medicine of Banat “Regele Mihai I
al Romaniei” from Timișoara, Calea Aradului nr.119, 300645 Timișoara Romania
3
Laboratory of Advanced Researches in Environmental Protection, Department of Biology-Chemistry, West
University of Timișoara, 16 Pestalozzi, 300316 Timișoara, Romania
1
Anabolic steroids are testosterone derivatives that increase the metabolism of ingested proteins and facilitate the
synthesis of skeletal muscle. They are a class of drugs legally available only by prescription, but non-medical use
of anabolic steroids is found especially in sports for performance improving, but also by young people obsessed
with body image. There are many health risks from the use and abuse of anabolic steroids because they have a
lot of side effects.
There are three structural files in the Protein Data Bank concerning the structures of the human androgen
receptor ligand-binding domain (hARLBD) in complex with two natural androgens (testosterone and
dihydrotestosterone) and with an androgenic steroid used in sport doping (tetrahydrogestrinone). Starting from
these structures we assess the affinity binding of a few synthetic androgenic oral administrable steroids:
oxymetholone, oxandrolone, methandrostenolone and stanozolol to the human androgen receptor. Molecular
docking studies reveal that all these steroids are able to bind to the hARLBD and the interactions energies are
presented in Table 1, in addition to the molecular properties of the investigated steroids.
Table 1. Molecular properties of steroids and their interaction energies with the human androgenic receptor
ligand-binding domain
Androgenic steroid
testoterone
oxymetholone
oxandrolone
methandrostenolone
stanozolol
Molecular
weight
(Da)
288.42
332.48
306.42
300.43
328.49
Molecular
surface (Å2)
Molecular volume
(Å3)
244.4
276.1
251.9
252.9
274.9
263.2
306.2
278.7
275.8
304.0
Interaction
energy
(kcal/mol)
-1400.63
-1350.53
-1359.39
-1369.55
-1356.99
ΔG
(kcal/mol)
-10.06
-8.83
-8.65
-9.34
-8.43
The methandrostenolone posses the highest binding affinity for hARLBD, its molecular properties being the
most similar to those of the natural ligand, testosterone, illustrating that even small differences in the ligand
structure have a great impact on the interaction strength.
153
S4 P02
IMPROVED DIELECTRIC RESONATOR ANTENNAS WITH HALF SPLIT BNT RESONATORS
M. G. BANCIU , L. NEDELCU, D. GEAMBAŞU
Dielectric resonators of barium neodymium titanate (BMT) provide significant size reduction even at low
frequencies due to the very high dielectric constant (up to 92) and moderate loss (product quality factor times
frequency ~6THz) [1]. The lead addition not only increases the dielectric constant but offers a good control of
the temperature coefficient of the resonance frequency f.
We recently showed that the dielectric constant of BNT resonators is so high, that high-order modes can be used
together with the fundamental mode for radiation purposes [2]. However, the resonance modes exhibit high
radiative quality factor when the dielectric constant is very high [3]. In this work, in order to develop dielectric
resonator antennas (DRA) with increased bandwidth, half-split resonators were investigated. Previous
researchers aimed the size reduction and placed the symmetry axis in the ground plane for the probe-fed DRA. In
dissimilarity with this, in our work, the size reduction is obtained by the material characteristics. We fed the
resonator with a microstrip line and investigated the possibility of coupling two modes in order to increase the
impedance bandwidth. In order to achieve this, two methods are proposed. The first one uses a microstrip cross
stub and the resonator is placed in asymmetrical way over the stub. The second uses only the microstrip line and
Acknowledgements: This work was partially supported by the Romanian Space Agency, ADANSPACE project
63/29.11.2013.
References
1. A. Ioachim, M. I. Toacsan, M. G. Banciu, L. Nedelcu, H. Alexandru, C. Berbecaru, D. Ghetu, and G. Stoica,
“BNT ceramics synthesis and characterization,” Mater. Sci. Eng. B, vol. 109, No. 1-3, pp. 183–187, 2004.
2. O. G. Avădănei, G. M. Banciu, I. Nicolaescu, L. Nedelcu, “Superior Modes in High Permittivity Cylindrical
Dielectric Resonator Antenna Excited by a Central Rectangular Slot”, IEEE Trans. Antennas Propagat., vol. 60,
No. 11, pp. 5032-5038.
3. A. Petosa, and A. Ittipiboon “Dielectric resonator antennas: a historical review and the current state of the art”,
IEEE Antennas and Propag. Magazine, 2010, vol. 52, (5), pp. 91-116, 2010.
154
S4 P03
COMPLEX MONITORING AND ALERT SYSTEM FOR SEISMOTECTONIC PHENOMENA
Victorin-Emilian TOADER, Iren-Adelina MOLDOVAN, IONESCU Constantin
National Institute for Earth Physics e-mail: [email protected]
The paper describesa complex multidisciplinary monitoring system designed for Vrancea seismic area (bending
zone of Carpathians Mountains). This includes hardware (stations with sensors, acquisition and communication
equipment) and software for data processing in real time. The result of this project is the growth ofan alert
service through: perfecting risk evaluation, seismic and climate forecast, informing the decision factors regarding
the impact minimization of natural disasters and the education of the population. The information from database
will help the scientists to develop the system and to improve their knowledge for other applications.
A monitoring network involves a multidisciplinary activity that highlights the interdependence of environmental
factors (air, earth) and their balance under normal conditions. Weather or seismic events represent the point of
maximum imbalance.
Electromagnetic,
infrasound,
seismoacoustic,
air ionization and
solar
radiation monitoring,
in
correlation with global and local environmental factors (including seismic zones), is a new approach for
atmospheric study in our area.Figure 1 describes a global structure of system.
Fig. 1 General structure of a complex monitoring station and data processing
Data are acquired from ground (National Institute for Earth Physics seismic stations) and satellites..
155
S4 P04
HYSTERESIS AND BISTABILITY IN THE I-V CHARACTERISTICS OF p-n JUNCTIONS
A. KLYUKANOV, R. SCURTU, I. INCULEŢ, P. GAŞIN
Semiconductor Physics Lab, Faculty of Physics and engineering, Moldova State University.
We study the problem of I-V characteristics of planar p-n junction from the view point of nonlinear
dynamics. In order to evaluate analytically a kinetic function describing a charge balance of nonlinear system we
propose a simple model of planar p-n junction and consider a possibility of observation of bistability and
hysteresis. First of all the basic equations of planar p-n junction are nonlinear due to the generationrecombination term described by the Shockley-Read-Hall formalism, secondly origin of the nonlinearity is the
Boltzmann distribution of the carriers. We determine a model of p-n junction by the next interpolation of
generation-recombination rate
 n( x )  n p 0

x  xp
x x
p ( x)  p n 0
U ( x)  {
, [d1 , x p ]},{U p  (U 0  U p )
, [ x p ,0]},{U n  (U n  U 0 ) n , [0, xn ]},{
, [ xn , d 2 ]}
1
xp
xn
2


(1)
and only consider direct charge pair recombination without a trapping. Here
U p  n( x p )  n p0 /  1
and
U n   p( xn )  pn0  /  2 . In steady state the parameter U 0 has to be found from the equation U 0 U (0) with
using of the Shockley-Read-Hall approximation at x  0 . We consider idealized p-n junction structure with an
abrupt doping step. Determination of model by equations (1) is considered as problem formulation. This gives us
E1 
kT
E (d1 )
q
, where E (d1 ) is the electric
the facility to reduce a number of unknown quantities till to one
field applied to the p-side, and to transform the charge continuity equations into a single kinetic equation of type
pt  nt  f ( E1 )  0
. Our model provides a solution of basic equations yielding an analytical expression for
1 , balancing the incoming and outgoing of charges at the p-n boundary x  0 .
nonlinear kinetic function
Continuity conditions for electron and hole currents together with continuity condition for electron concentration
f (E )
n(x) and for hole concentration p(x) at the interface x  0 leads to the system of four non-homogeneous
linear algebraic equations. The Shockley equation with account of parasitic resistance can be derived from the
system of these equations in the limit
U0
U 0  0 . Solving these equations at U 0  0 one obtains the parameter
E1 and V . To calculate the I-V characteristics of the planar p-n junction the parameter E1
as a function of the bias voltage V must be evaluated numerically from the transcendental algebraic equation
dependent on
pt  nt  f ( E1 ,V )  U 0 ( E1 ,V )  U (0)  0
(2)
On the basis of equations (1,2) one can analyze the non equilibrium carrier and current densities, electric
field strength and recombination-generation rate versus position x at various applied voltage.
The competition between recombination and diffusion contributions is evident. Recombination current
dominates if the lifetime in the neutral region is much more than that in the depletion. Numerical results obtained
for the I-V curves show that our model is in agreement with the experiment. 1,2
References
1. S.M.Sze, Kwok K.Ng, Physics of semiconductor devices. Hoboken. New Jersey. 2007
2. W.Monch. Electronic properties of Semiconductor Interfaces. Springer, 2004
156
S4 P05
AFM STUDY OF THE MORPHOLOGICAL MODIFICATIONS INDUCED BY DIFFERENT
DECONTAMINATION TREATMENTS ON ESCHERICHIA COLI
ZORILA Florina Lucica, IONESCU Cristina, CRACIUN Liviu Stefan, ZORILA Bogdan
Horia Hulubei National Institute for Physics and Nuclear Engineering, P.O.B. MG-6, 077125 Magurele,
Romania
In this study the atomic force microscopy (AFM) was used to compare morphological modifications on
Escherichia coli, induced by different chemical and fizical decontamination treatments. Escherichia coli is an
important Gram negative bacteria used in clinical and environmental study. The bacterial suspensions was
treated with chemical substances utilized in surfaces decontamination (alcoholic solutions, chlorine solution) at
sub-minimum inhibitory concentrations (MICs) and UV light emited by a lowpressure mercury lamp (254 nm).
The surface topography of Escherichia coli attached on mica substrate was acquired in tapping mode under
ambient condition. The results show that each type of treatment induce his one modifications, from reducing
cells dimensions to a wrinkled appearance of cells surfaces, collapse and cells destruction.
Figure 1. 3D high resolution AFM images of Escherichia coli (a). untreated bacteria; b) alcoholic solution 70%;
c) chlorine solution; d) UV ) immobilized on mica substrate. Image size 10x10 μm2
Keywords: AFM, Escherichia coli, decomtamination treatment
1.
High-resolution Atomic Force Microscopic Imaging of Escherichia coli Immobilized on Mica Surface,
Suthiwan Udomrat, Suwatchai Praparn, Theeraporn Puntheeranurak, Journal of Microscopy Society of Thailand
2009, 23(1): 38-41;
2.
Measuring bacterial cells size with AFM, Denise Osiro, Rubens Bernardes Filho, Odilio Benedito
Garrido Assis, Lúcio André de Castro Jorge, Luiz Alberto Colnago, Brazilian Journal of Microbiology (2012):
341-347, ISSN 1517-8382.
157
S4 P06
INFLUENCE OF MENTAL TIREDNESS IN FIXATIONAL EYE MOVEMENTS DYNAMICS
Corina ASTEFANOAEI1, Dorina CREANGA1, Leandro L. Di STASI2, Michael B. MCCAMY2, Susana
MARTINEZ-CONDE2, Tudor LUCHIAN1
1
2
Department of Physics, University Alexandru Ioan Cuza, Iasi, Romania
Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, USA
Microsaccades are defined as short duration and small amplitude eye movements that occur 3-4 times
per second, during voluntary fixation of an object (Fig. 1). We analyzed such fixational eye movements recorded
from healthy human subjects through an experiment designed in order to evaluate the influence of mental fatigue
during prolonged visual exploration and fixation.
The recording session for one subject had a total time of two hours and it was divided in four blocks of about 30
minutes each; the subject did not rest between blocks. We considered that the evolution from one block to
another causes a higher degree of subject's mental tiredness. During each block, fixation conditions were
interleaved with free-viewing conditions. In the fixation condition the subjects were asked to keep their visual
attention focused on the central fixation spot. The analyses were conducted with data representing the eye
Fig. 1. Microsaccadic signal
1.
2.
Fig. 2. State space portrait for 4 consecutive
time intervals
position upon time, extracted only from the fixation conditions of the four blocks. Fourier transform, autocorrelation function, Hurst main exponent, phase space portrait, and Lyapunov exponent were the main
computational tools for the diagnosis of the dynamical type in the neural pathway responsible for the
microsaccades. Comparative analyses revealed similar power spectra and auto-correlation function along the
entire recording as well as the data histograms and Hurst exponent. High values of auto-correlation time were
emphasized. However the state space portrait reconstructed in delay coordinates evidenced semi-quantitative
differences among the four sub sets of data (S1-1, ..., S1-4) as visible in Fig. 2. Overlapping of chaotic and quasiperiodic trends were rebealed. Fatigue influence is going to be further investigated in different subjects to get
comparative data on fixational movements evolution during specific experimental design.
Martinez-Conde,S., L.Macknik, S., Hubel H.D., The role of fixational eye movements in visual perception,
Nature Reviews, Neuroscience, 5, 229-240 2004.
Carpenter, R. H. S. Movements of the Eyes, 2nd Edition, Pion, London, 1988, 593 pp.
158
S4 P07
CHARACTERIZATION OF HIP IMPLANTS USING WDXRF SPECTROMETRY
Simona MIHAI 1,4, Iulian BANCUTA1, Roxana BANCUTA2,4, Viviana FILIP1, Gheorghe. V. CIMPOCA1,3, Ion
V. POPESCU1,3, Gheorghe VLAICU5
1
Valahia University of Targoviste, Multidisciplinary Research Institute for Sciences and Technologies, 130024,
Targoviste, Romania, E-mail: [email protected]
2
The Water Company from Targoviste, Dambovita County, 130055, Romania
3
Academy of Romanian Scientists, 050094, Bucharest, Romania
4
Valahia University of Targoviste, Doctoral School, 130105 Targoviste, Romania
5
The Special Steel Plant Targoviste S.A, 130087, Targoviste, Romania
Over the past 20 years replacement prostheses have been developed and refined to enhance durability and
reproducibility. Total hip arthroplasty is being performed in an increasing number of younger patients; therefore
orthopaedic surgeons seek implants with a longer life span. With regards to the progress of mechanical
behaviour of the biomaterials used in an arthroplasty, little is known about the long-term biological effects of
wear debris. The composition of the prostheses currently in use it is very important for knowing and anticipating
of these effects. In this paper have been analysed five samples of different components of the hip prosthesis by
Wavelength Dispersive X-ray Fluorescence (WDXRF). Their potential toxicity, hypersensitivity and
carcinogenicity it will be also discussed in this paper.
Keyword: hip implants, WDXRF, arthroplasty.
S4 P08
THE ANTHOCYANINS STABILITY TO LIGHT AND pH FOR ITS USE IN DSSC
Andrei CHILIAN1,2, Oana-Roxana BANCUTA1,2, Iulian BANCUTA3, Rodica-Mariana ION4,5, Radu
SETNESCU6,7, Anca-Irina GHEBOIANU3, Tanta SETNESCU6,7, Cristiana RADULESCU6, Ion V.
POPESCU6,8, Gabriel DIMA6
1
Valahia University of Targoviste, Doctoral School, 130105 Targoviste, Romania, E-mail:
[email protected]
2
The Water Company from Targoviste, 130055 Targoviste, Romania
3
Valahia University of Targoviste, Multidisciplinary Research Institute for Sciences and Technologies, 130082
Targoviste, Romania
4
National Research & Development Institute for Chemistry, 060021, Bucharest, Romania
5
Valahia University of Targoviste, Faculty of Materials Engineering and Mechanics, 130082 Targoviste,
Romania
6
Valahia University of Targoviste, Faculty of Sciences and Arts, 130082 Targoviste, Romania
7
R&D Institute for Electrical Engineering, Department for Advanced Materials, 030138 Bucharest, Romania
8
Romanian Academy of Scientists, 050094, Bucharest, Romania
The anthocyanins are organic pigments, very common in nature. In recent years, these compounds were tested
in many areas, including the manufacture of dye-sensitized solar cells (DSSC). At present, the most efficient
dyes for the industry are based on ruthenium and therefore their cost is rather high. The anthocyanins cost could
be much lower, but their efficiency also is much lower. By UV-VIS spectrophotometry it was identified the
stability conditions of these compounds on the pH and the light to be applied in DSSC.
Keywords: anthocyanins stability, DSSC, UV-VIS spectrophotometry.
159
S4 P09
ENVIRONMENTAL ANALYSIS BY X-RAY FLUORESCENCE. DETERMINATION OF
POLLUTANTS FROM STEELWORKS DUST BY WDXRF TECHNIQUE
1
Gheorghe VLAICU, 2Iulian BANCUTA, 1Florin PARSAN, 1Nicolae PAVEL, 3,4Oana Roxana
BANCUTA, 5Claudia STIHI, 2,6Gheorghe Valerica CIMPOCA, 2,6Ion V. POPESCU
1
The Special Steel Plant Targoviste S.A, 130087, Targoviste, Romania, E-mail: [email protected]
Valahia University of Targoviste, Multidisciplinary Research Institute for Sciences and Technologies,
130082, Targoviste, Romania
3
Valahia University of Targoviste, Doctoral School, 130105 Targoviste, Romania
4
The Water Company from Targoviste, 130055, Targoviste, Romania
5
Valahia University of Targoviste, Faculty of Sciences and Arts, 130082, Targoviste, Romania
6
2
Abstract: Metallurgy, steelmaking process, generates large amounts of dust steelworks. This dust has a
negative impact on the environment due to several pollutants that are found in high concentrations: Cd, Pb, Zn,
S, Cl. Full determination of the chemical composition of steelworks dust is critical for at least of two aspects. On
one side is the monitoring of pollutants harmful to the environment, the design of high efficiency cleaning
facilities with retention of these compounds, storage and management of these waste products. On the other hand
it is important to know the concentration of various oxides of Fe, Cr, Zn, Pb, in the operations of recovery of
such wastes. The paper proposes the complete determination of the chemical composition of steelworks dust
from COS Targoviste, Romania by X-ray fluorescence (WDXRF technique) on samples pressed.
Keyword: dust steelworks, WDXRF
S4 P10
THERMAL CHARACTERIZATION OF THE RESVERATROL
Oana Roxana BANCUTA1,2, Iulian BANCUTA3, Andrei CHILIAN1,2, Radu SETNESCU4,5, Tanta
SETNESCU4,5, Rodica ION6,7, Gheorghe Valerica CIMPOCA3,8, Ion V. POPESCU3,8, Anca Irina GHEBOIANU
3
, Gheorghe VLAICU9
1
Valahia University of Targoviste, Doctoral School, 130105 Targoviste, Romania, E-mail:
[email protected]
2
The Water Company from Targoviste, 130055, Targoviste, Romania
3
Targoviste, Romania
4
Valahia University of Targoviste, Faculty of Sciences and Arts, 130082, Targoviste, Romania
5
R&D Institute for Electrical Engineering, Department for Advanced Materials, 030138 Bucharest, Romania
6
National Research & Development Institute for Chemistry, 060021, Bucharest, Romania
7
Valahia University of Targoviste, Faculty of Materials Engineering and Mechanics, 130082, Targoviste,
Romania
8
9
The Special Steel Plant Targoviste S.A, 130087, Targoviste, Romania
Abstract: Resveratrol, or 3,4’,5-trihydroxystilbene is a type of polyphenol that has attracted attention as a natural
antioxidant and it is found in many natural foods (e.g., grapes, red wine, purple grape juice, and some berries). In
plants, a major form of resveratrol is trans-resveratrol-3-O-β-D-glucoside, often referred to as piceid. In this
paper was followed effect of temperature on the trans-resveratrol till to total degradation. This is important
because resveratrol can be introduced as a natural antioxidant in the polymer (such as LDPE, HDPE, etc.) and
the degradation time and temperature of resveratrol is unknown. Once inside the polymer resveratrol can
influence biodegradation of this polymer in a manner beneficial to the environment.
Keyword: polyphenol, resveratrol, polymer
160
S4 P11
ANALYTICAL DESCRIPTION OF THE NONLINEAR DYNAMICS OF BOSE-EINSTEIN
CONDENSATES BY MEANS OF GENETIC ALGORITHMS
Mihaela Carina RAPORTARU1, Jane JOVANOVSKI2, Boro JAKIMOVSKI2, Dragan JAKIMOVSKI2, Anastas
MISHEV2
1
Horia Hulubei National Institute of Physics and Nuclear Engineering, Department of Computational Physics
and Information Technologies, Reactorului 30, Magurele, Ilfov, Romania
2
"Ss Cyril and Methodius" University in Skopje, Faculty of Computer Science and Engineering, Rugjer
Boshkovikj 16, Skopje, Macedonia
Email: [email protected]
In this paper we show that parallel genetic algorithms provide an accurate analytical description of the nonlinear
dynamics of a Bose-Einstein condensate. We consider a spherically symmetric condensate subject to periodic
and aperiodic parametric excitations and show that the standard variational equation which describe the timeevolution of the condensate has simple analytical solutions. These solutions are obtained using parallel genetic
algorithms and allow us to quantify analytically distinct physical processes such as resonant energy transfers and
mode-lockings. The observed efficiency of this method for the aforementioned one-dimensional variational
equation suggests that this method can be efficiently used for charting the stability spectrum of condensates
subject to parametric excitations and possibly for the description of optic waves travelling in nonlinear media.
Acknowledgements: The authors thank A.I. Nicolin and M. Dulea for numerous fruitful discussions. The work of
M.C. Raportaru is covered by PN 09370104/2014. The authors acknowledge the use of resources provided by
the NGI MARGI, as part of the European Grid Infrastructure.
161
S4 P12
X-RAY STRUCTURE ELUCIDATION OF New Pyrrolo DERIVATIVES
Costel MOLDOVEANU, Gheorghiţă ZBANCIOC, Dorina MANTU, Vasilichia ANTOCI, Ionel
MANGALAGIU
"Al. I. Cuza” University of Iasi, Organic and Biochemistry Department, 11 Carol 1 st Bd., 700506 Iasi, Romania.
Due to their wide range of potential applications, from electroluminescent materials to macrocyclic fluorescent
sensors,1,2 the synthesis of azaindolizines has received increasing interest during the last years. In particular, the
interest in pyrroloquinoxaline derivatives arises from their highly efficient blue fluorescence emission 3, which
makes them attractive materials in optoelectronics for blue organic light-emitting diodes.
Herein we report the structure elucidation of two new class of pyrrolo derivatives: N-aryl pyrrol 3a,b and 4-oxo4,5-dihydropyrrolo[1,2-a]quinoxaline 4b obtained by cycloaddition of the benzo[d]imidazolium ylides 2 to
DMAD (dimethyl acetylenedicarboxylate) as activated Z-alkynes.
The benzo[d]imidazolium ylides were generated ‘in situ’ from the corresponding benzo[d]imidazolium salts 1,
using Et3N as base according to Khronke salt method.4
The corresponding cycloadducts are unstable; they suffer an imidazol ring opening to N-aryl pyrolo derivatives
which can be stable (in the case of 3a) or can eliminate MeOH to close a more stable 6 atom pyrazine ring (in the
case of 4b) Scheme 1.
The structure of the new compounds was proven by elemental (C, H, N), spectral analysis (IR, 1H NMR, 13C
NMR, 2D-COSY, HMQC, HMBC) and X-Ray analysis. All the elemental and spectral data are in accordance
with the proposed structure.
Acknowledgement:
To CNCS - UEFISCDI, grant PN-II-TE/ 0010 -79/05.10.2011 (director lect. dr. Costel Moldoveanu) for
financial support.
References:
1. B. Valeur, Molecular Fluorescence, Ed. Wiley-VCH, Weinheim, 2002.
2. M.A. Thompson and S.R. Forrest, Nature 2000, 403, 750.
3. T. Mitsumori, M. Bendikov, J. Sedo and F. Wudl, Chem. Mater. 2003, 15, 3759.
4. E. Krohnke, Ber. Dtsch. Chem. Ges. 1935, 68, 1177.
162
S4 P13
NEW PYRROLOQUINOXALINE COMPOUNDS: SYNTHESIS AND SPECTRAL ANALYSES
Gheorghiţă ZBANCIOC1, Costel MOLDOVEANU1, Ana Maria ZBANCIOC2, Gabriela TATARINGA2, Ionel
MANGALAGIU1
1.
"Al. I. Cuza” University of Iasi, Organic and Biochemistry Department, Bd. 1 st Carol 11, 700506 Iasi,
Romania.
2
University of Medicine and Pharmacy “Grigore T. Popa” Iasi, Str. Universitatii 16, 700115 Iasi, Romania.
Synthesis azaindolizines has received increasing interest during the last years driven by a wide range of potential
applications, from electroluminescent materials to macrocyclic fluorescent sensors.1,2 In particular, the interest in
pyrroloquinoxaline derivatives arises from their highly efficient blue fluorescence emission 3, which makes them
attractive materials in optoelectronics for blue organic light-emitting diodes.
Initially, we generate ‘in situ’ the benzo[d]imidazolium ylides 2, from the corresponding benzo[d]imidazolium
salts 1, using Et3N as base. In the next step, the ylides 2 were treated with DMAD (dimethyl
acetylenedicarboxylate) or methyl propiolate (as activated Z-alkynes), leading to the corresponding fused
pyrroloquinoxaline derivatives 4, Scheme 1.
In the case of cycloaddition reaction of ylides 2 with the symmetrical substituted alkynes DMAD, the reaction
occur again as a normal Huisgen [3+2] dipolar cycloaddition, leading pyrroloimidazole derivatives 3 which
suffering a intramolecular rearrangement, lead to the more thermodynamically stable pyrroloquinoxaline ring.
The structure of the new compounds was proven by elemental (C, H, N), spectral analysis (IR, 1H NMR, 13C
NMR, 2D-COSY, HMQC, HMBC) and X-Ray analysis. All the elemental and spectral data are in accordance
with the proposed structure.
ACKNOWLEDGEMENT: To CNCS - UEFISCDI, grant PN-II-TE/ 0010 -79/05.10.2011 (director lect. dr.
Costel Moldoveanu) for financial support.
REFERENCES:
5.
B. Valeur, Molecular Fluorescence, Ed. Wiley-VCH, Weinheim, 2002.
6.
M.A. Thompson and S.R. Forrest, Nature 2000, 403, 750.
7.
T. Mitsumori, M. Bendikov, J. Sedo and F. Wudl, Chem. Mater. 2003, 15, 3759.
8.
E. Krohnke, Ber. Dtsch. Chem. Ges. 1935, 68, 1177.
163
S4 P14
CORRELATION BETWEEN THE SECONDARY STRUCTURE ELEMENTS IN THE SPATIAL
ARRANGEMENT OF THE EF-HAND CALCIUM BINDING PROTEINS
Dana CRACIUN1, Adriana ISVORAN2
1
Teacher Training Department, West University of Timisoara, 4 V.Pirvan, 300223 Timisoara, Romania
2
Department of Biology-Chemistry, West University of Timisoara, 16 Pestalozzi, 300316 Timisoara,
Romania
A large number of calcium binding proteins contain an EF-hand structural motif being called EF-hand
calcium binding proteins (EFCaBPs) and exhibiting extended or compact spatial structures in strong correlation
with their biological functions [1]. We obtained the description of secondary structure motifs of EFCaBPs using
the SA-Mot analysis method [2] and we analyzed the presence of long-range correlation between the successive
positioning of the secondary structure elements in the spatial arrangement of proteins using the non-linear
analysis methods: spectral analysis (SA) and detrended fluctuation analysis (DFA) respectively. SA method
gives the spectral coefficient, α [3] and DFA method gives the scaling exponent, β [4], those values are used to
characterize the series of evaluated data. The values of the two coefficients are presented in Figure 1.
1.36
1.4
spectral coefficient
spectral coefficient
1.5
1.3
1.2
1.1
1.32
1.28
1.24
1.20
1.16
0
2
4
6
8
10
12
0
structure number of compact EFCaBPs
1.2
4
6
8
10
1.1
scaling exponent
scaling exponent
2
structure number of extended EFCaBPs
1.0
0.8
1.0
0.9
0.8
0.6
0
2
4
6
8
10
structure number of compact EFCaBPs
12
0.7
0
2
4
6
8
10
structure number of extended EFCaBPs
Fig.1 The values of the spectral coefficient and the scaling exponent obtained for the secondary structural
data of EFCaBPs
The mean values of the spectral coefficient are α=1.38±0.12 and α=1.32±0.11 for extended and compact
EFCaBPs respectively. ANOVA statistical test reflects that, at 0.05 level, the two means are not statistically
distinct. It is also true for the values of the scaling exponents: β=1.02±0.03 and β=0.91±0.01 for extended and
compact EFCaBPs respectively. These values reveal long-range correlation in the successive positioning of the
secondary structure elements in the spatial arrangement of EFCabPs and there are not distinct characteristics for
extended and compact EFCaBPs.
References
1. Lewit-Bentley A, Rety S Curr Opin Struct Biol (2000) 10:637.
2. Regad L, Martin J, Nuel G, Camproux AC, BMC Bioinformatics (2010) 11:75.
3. P. Szendro, G. Vincze, A. Szasz, Eur Biophys J (2001) 30:227
4. C.K. Peng, S.V. Buldyrev, S. Havlin, M. Simons, H. E. Stanley, A. L. Goldberger, Phys. Rev. E (1994)
491685.
164
S4 P15
SOME SIMPLE CONSIDERATIONS REGARDING THE PROBABILITY OF LIFE
APPEARANCE ON EARTH BY CHANCE
Dan CHICEA1,2, Radu CHICEA3, Liana Maria CHICEA3
1- Department of Environmental Sciences, Lucian Blaga University, Dr. Ion Ratiu str. No. 5-7, Sibiu, 550012,
ROMANIA
2 - Pediatric Respiratory Medicine Research Center (CCMRP), Str. Pompeiu Onofreiu Nr. 2– 4, Sibiu,
ROMANIA
3-Victor Papilian Faculty of Medicine, Lucian Blaga University, Sibiu
A very simple model can be established to asses the probability that the protein encoding genes sequence came
in the right order, in the Last Universal Common Ancestor (LUCA hereafter), by chances. We can consider
only the protein encoding genes, not al the genes, to be ready made entities that can combine in a randomly
combining experiment that is repeated continuously. We can consider the expected event to be achieved when
the protein encoding gene sequence is the sequence that could be found in LUCA, hereafter the right sequence.
As the purpose of this simple model is to assess the magnitude of certain probabilities not the exact values, we
can simply ignore the symmetry; with this assumption the combination 1-2-3 is different from 3-2-1, for
instance. Moreover, we can consider that during the early stage of existence of the Earth, this was a huge
laboratory where this combinatorial experiment was carried on constantly. We can assume that one
combinatorial experiment was completed every second. The number of experiments that was completed in one
year was 365 days times 24 hours a day times 3600 seconds per hour, which is 31536000. And more, if we
consider that the combinatorial experiment took place in parallel in one billion, 10 12, places, each trying
different combinations, in one year the total number of combinations that were tried is 3.1536*10 19.
If we move further, the total number of possible combinations of n entities to form a chain is n!. For big
numbers the Stirling approximation was used:
lnn!  n  lnn  n  ln 2 n
(1)
Afterwards we can estimate the factorial, as in eq. (2).
n! explnn! (2)
The total number of possibilities for a number of entities from 2 to 50 was computed and the time required for
trying all the possible combinations, in the above mentioned hypothesis was assessed. The number of essential
genes in a simple organism like LUCA was estimated to be 300 and for this number the time required to
complete the experiment was estimated to be 10588 years. The age of the Earth was estimated to be 4.5·10 9 years
and the age of the Universe to be 13.798·10 9 years, which are ridiculously small as compared with the time
required by the experiment to be completed, therefore we can conclude that the probability that life appeared by
chance is too small to consider this hypothesis as the ultimate one.
References
1. Glansdorff N., Xu Y., Labedan B., (2008), The Last Universal Common Ancestor: Emergence, constitution
and genetic legacy of an elusive forerunner, Biology Direct 3, 29, doi:10.1186/1745-6150-3-29,
http://www.biologydirect.com/content/pdf/1745-6150-3-29.pdf
2. Ouzounis C.A., Kunin V., Darzentas N., Goldovsky L., (2006), A minimal estimate for the gene content of
the last universal common ancestor – exobiology from a terrestrial perspective, Res. Microbiol 157, 57-68.
165
S4 P16
MICROWAVE NON-THERMAL INFLUENCE ON PHANEROCHAETE CHRYSOSPORIUM CELLS
L. OPRICA1, G. VOCHITA2, D. CREANGA3, S. MICLAUS4
1“
Alexandru Ioan Cuza” University, Iasi, Romania; Biology Faculty; e-mail: [email protected],
2
Institute of Biological Research, Iasi, Romania; e-mail:[email protected]
3“
* Alexandru Ioan Cuza” University, Iasi, Romania; Physics Faculty; e-mail: [email protected],
4
Land Forces Academy, Sibiu, Romania, e-mail:[email protected]
Units/mg of protein
Like other living organisms from different biosphere ecological nisches the cellulolytic fungi are constantly
subjected to physical and chemical stress
factors from natural and artificial sources.
160
The study of such microorganisms is
important due to their capacity of degrading
140
wood waste and therefore contributing to
120
environment rehabilitation. One of the
major
consequences
of
various
100
environmental constraints, of physical or
80
chemical origin, is the oxidative stress
SOD 14 days
mediated by increased levels of reactive
60
MDA 14 days
oxygen species. Among environmental
SOD 7 days
40
factors generating reactive oxygen species
SOD 7 days
20
the most studied are ionizing radiations (,
β, γ, and X-rays) and UV rays but during
0
latest half century electromagnetic waves
control SAR 1 - SAR 1 control SAR 2 - SAR 2 raised also the scientific interest related to
1h
4h
1h
4h
biosphere safety [1]. We present the results
of fungi exposure to non-thermal
Fig. 1. Biochemical parameters assayed in fungi cells
microwaves (970 MHz, SAR of 2 J/kg and
SOD-superoxidedismutase, CAT-catalase,
8 J/kg) with focus on lipid peroxidation.
MDA-malonaldehyde
Linear increase on the exposure time was
noticed for highest SAR level compared to
lower one where non-linear variation of the three parameters was evidenced (Fig. 1). The results suggest
enzyme biosynthesis intensification as needed to fight against reactive oxygen species but also lipid
peroxidation increasing. As microwaves significantly perturbed fungus cell metabolism at the level of lipid
peroxidation the concern on the membrane integrity and functions was raised not only for the main cell
membrane but also for the nuclear membrane, thus threatening DNA molecules with possible genetic
consequences. So, atmospheric microwave polluting effect could damage cellulolytic fungi and indirectly could
impair wood waste degrading i.e. the environment self-cleaning mechanisms.
References
[1] Su R., He L-n, Xu Q-p., Su H., Zhao S., J. Yunnan Univ. (Nat. Sci.), 2009, 31 (2), 200-203.
166
S4 P17
LYAPUNOV EXPONENT IN SACCADIC EYE MOVEMENTS
ASTEFANOAEI, C. 1, AGHEORGHIESEI, C.1, PRETEGIANI, E. 2, CREANGA, D.1, OPTICAN L.3, RUFA,
A.2
1
Physics Department, University Alexandru Ioan Cuza, 11 Blvd. Carol I., Iasi, Romania, e-mail:
[email protected], [email protected]
2
Eye-tracking&Visual Application Lab EVALab, Department of Medicine Surgery and Neuroscience, University
of Siena, Siena 53100, Italy, e-mail: [email protected], [email protected]
3
Laboratory of Sensorimotor Research, IRP, National Eye Institute, DHHS, Bethesda, MD, 20892, USA, e-mail:
[email protected]
The study of rapid eye movements known as saccades is of actual importance for neurobiophysics as well as for
neurology since saccadic data series bear information on visuo-motor systems with many implication in humans
life [1-3]. The investigated voluntary subjects participated in a two-part experiment: a simple saccadic task
(visually guided, organized according to Saslow protocol, [4]) and a dual saccade-decision task – with additional
mission of assessing chronology of light stimuli pairs used for saccade triggering. Eye position was tracked with
specific laser beam recording device resulting in temporal series of long duration (Fig. 1). To analyze the
saccadic neurosystem sensitivity to initial conditions largest Lyapunov exponent (LyEx) was calculated using
adequate mathematical iteration algorithm. Segmentation of the recorded temporal series was carried out
planning to evidence variation of LyEx values along recording session duration when subject attention is
supposed to change or fatigue to concur with attention. Graphical representation of LyEx distributions in the two
types of saccadic series was used as box chart diagrams to compare the saccadic system dynamics during long
recording sessions. It was concluded that non-linear dynamics underlying neural saccadic pathways could be
described applying this mathematical algorithm proposed for emphasizing chaotic systems behavior with
possible application in designing alternative computational tool for psychophysics approach of eye movement.
Acknowledgement. This research was supported by FP
7 Project IRSES People 269263 “CERVISO”.
References
[1]Daye P M, Optican L M, Roze E, Gaymard B and
Pouget P, J Translat Med 2013, 11:125
[2]Leigh R J and Kennard C Using saccades as a
research tool in the clinical neurosciences Brain 2004,
127 460-77
[3]Wong A L and Shelhamer M, Ann Biomed Eng
2013, 41 1613-24
[4] Saslow M, J Opt Soc Am 1967, 57 1024-29
Fig. 1. Segment of saccadic temporal series
167
S4 P18
GENOTOXICITY STUDY ON UV-C RADIATION IN THE VEGETAL ORGANISMS
Alexandra-Cristina UTA1, Claudia NADEJDE1, Dorina CREANGA1, Gabriela VOCHITA2
1
Faculty of Physics, Alexandru Ioan Cuza University, 11 Blvd. Carol I, Iasi, Romania
2
Institute of Biological Research, Iasi, Romania
This experimental study was focused on some bioeffects induced by UV-C radiation in seedlings of maize (Zea
mays) samples: control, P1 exposed 2 h/day and P2 exposed 4 h/day. Genotoxicity was assessed by cytogenetic
methods based on root cell meristeme investigation at about three days after germination. Photosynthetic
pigments levels were assayed by spectrophotometric measurement carried out in the green tissue of ten days old
seedlings. Radiation source was a UV-C lamp (254 nm, 30 W), Nikon type microscope was used for cytogenetic
data gathering while Shimadzu device was used for spectral investigation. Remarkably increased percentage of
cells with abnormal divisions was estimated (Fig. 1) following UV-C rays impact. The main types of
chromosmal aberrations were highlighted in all root meristeme tissues: expelled and retarded chromosomes,
inter-chromatin bridge (Fig. 1) and micronuclei. However the influence of UV-C radiation on the mitotic
division rate was insignificant as resulted from mitotic index calculation since growing stimulation was not
Fig. 1. Mitotic cell percentage in maize tissue
Fig. 2. Chlorophyll ratio measuring photosynthesis rate
significant. As found in other experiments carried out on vegetal organisms, phenomena stimulation and
inhibition of the synthesis of assimilatory pigments has a complex dependence on the exposure parameters and
possible of some biological parameters. It was shown a negative effect on the reactions of chlorophyll and
carotenoid pigments biosynthesis - contents diminished with 20 to 40%; but the ratio of chlorophyll
A/chlorophyll B measuring photosynthesis efficiency ratio was only slightly increased (Fig. 2) suggesting
relative high stability of corresponding complex phenomena against UV radiation.
Concluding, genotoxicity of UV-C radiation was demonstrated in young maize seedlings but practically
unaffected photosynthesis.
References
Bara, I.C. Cytogenetic Effects of irradiation with UV at 6 Romanian cultivars of Phaseolus vulgaris L, Analele
Stiintifice ale Universitatii Al. I. Cuza” sectia Genetica si Biologie Moleculara, X, 51-55, 2009
Bornmann, J.F., Reuber, S., Cen, Y.P., Weissenbock, G., Ultraviolet radiation as a stress factor and the role of
protective pigments. In LUNDSE, J. (ed.), Plants and UV-B: responses to environmental changes, 157-168.
Cambridge University Press, Cambridge,1997.
168
S4 P19
MONOPOLY GAME ON NETWORKS
Szerena K. UJVARI1, Melinda VARGA2, Gabriel ISTRATE3 , Zoltan NEDA1,4
1
Babes-Bolyai University, Dept. of Physics, Romania
University of Notre Dame, Dept. of Physics, Center for Complex Networks, USA
3
Intitutul eAustria, Universitatea de Vest din Timisoara, Romania
4
Edutus College, Department of International Business, Hungary
2
In order to simulate wealth redistribution in a simple model society a monopolist game 1 is considered on
different network topologies. The rules of the game are simple. On the considered network each node starts with
the same initial wealth W. (2) Depending on the manner in which the players are chosen for a “game”, two
different type of games are defined. In the first version (a), in each step a random node is selected, and this node
plays a monopolist game with it's neighbors. Each player (i) puts an amount (1/n i ) from it's wealth in the pot (ni
represents the number of neighboring nodes that are able to pay (have nonzero wealth). In case one, or more
from the chosen players don't have enough wealth, everyone is asked to put in the pot the amount of money that
the poorer one has. The pot will be won by a randomly selected player. This step is repeated until there are no
two connected nodes in the network which can play another game. In the second case (b) in each step two
connected nodes are selected, by choosing a random edge from the network. The players will play if both of
them have nonzero wealth, otherwise another edge is slected. In order to play the game the players are asked to
put one unit from their wealth in the pot. One of them will win the pot by chance. This step will be repeated until
there are no neighbours that can play.
The above described simple interacting community was studied trough computer simulations using a
Monte Carlo method. The outcome of this game was analyzed on different network topologies: one dimensional
regular network, two dimensional regular network, Barabási-Albert scale-free network2, Erdős-Rényi random
network3 and a complete graph. It is found that according to the network type there are different scaling laws that
define the total number of steps needed to reach the final configuration. It is shown how the number of steps
needed to reach final configuration is increasing with network size and initial wealth. As a function of the initial
2
wealth, the time needed to reach the final configuration scales always as t ~ W . As a function of the system
α
size the scaling is nontrivial and we get: t ~ N . The α scaling exponent depends on the networks type, more
precisely on how the diameter of the network scales with its size. The scaling exponents for model (a) and (b) are
the same. In the final configuration the wealth distribution is also studied.
169
S4 P20
ASSESSMENT OF PESTICIDES INTERACTIONS WITH BACILLUS PASTEURII UREASE. A
COMPUTATIONAL STUDY.
Diana Larisa VLĂDOIU, Nicoleta FILIMON, Vasile OSTAFE, Adriana ISVORAN
Laboratory of Advanced Researches in Environmental Protection, Department of Biology-Chemistry, West
University of Timisoara, 16 Pestalozzi, 300316 Timisoara, Romania
Urease activity in soil may originate from plant residues, animal waste or soil microorganisms, but it is
generally assumed that microorganisms are responsible for most of urease activity in soil.
Two herbicides (chlorosulfuron and nicosulfuron) and one fungicide (difenoconazole) are considered in this
work and molecular docking studies have been implemented to evaluate their interactions with Bacillus
pasteurii urease, a soil microorganism enzyme using a bimetallic nickel active center. Structural
characterization of herbicides and fungicide is also performed by comparison to urea and known inhibitors of
urease and taking into account the protein surface description. The active domain of the Bacillus pasteurii
urease exposes 32 cavities on its surface, its active site being situated in the biggest polar cavity. The two
herbicides, chlorosulfuron and nicosulfuron, and the fungicide difenoconazole have higher dimensions than
urea and known ligands of Bacillus pasteurii urease (beta-mercaptoethanol, diamidophosphate,
acetohydroxamic acid) but only chlorosulfuron exhibits a region with pronounced negatively surface potential
as the inhibitors do.
Both herbicides and the fungicide are evaluated to strongly interact to Bacillus pasteurii urease, the most
favorable interaction being predicted for chlorosulfuron (table 1). All values inside table 1 are strongly
negative illustrating that the bound state of the protein has a more attractive energy than the unbound state.
Moreover, all the pesticide molecules provide the capacity to bind to urease in several places to the enzyme
surface, but only chlorosulfuron is proficient to bind to the catalytic site. It may be explained by the fact that
chlorosulfuron contains a negatively charged region that is assumed to interact electrostatically with the Ni 2+
ions present in the active site of the enzyme, the known inhibitors also exhibiting such a region.
Table 1. Interaction energies of pesticides with Bacillus pasteurii urease
Substrate/Pesticide
urea
difenoconazole
nicosulfuron
chlorosulfuron
Substrate/
volume (Å3)
47.05
330.70
309.60
261.50
Pesticide
Interaction
(kcal/mol)
-3866.45
-3750.12
-3974.46
-4010.47
energy
This study reveals that ligand binding to Bacillus pasteurii urease active site seems to depend on the ligand
surface polarity. Further experimental analysis is required to evaluate the effects of the predicted interactions.
S4 P21
ORDER AND DISORDER IN COUPLED OSCILLATORS
L. DAVIDOVA AND Z. NÉDA
Babeş-Bolyai University, Department of Physics,str. Kogălniceanu 1 nr. 1, 400084, Cluj-Napoca, Romania
A system of harmonic oscillators coupled by a common moving platform is a fascinating example of how
complex behaviors can emerge in a simple system, such as spontaneous in-phase or anti-phase synchronization.
Having performed an extensive numerical study on multiple variations of coupled oscillator systems, we can
show how its various properties and parameters affect the emergent synchronization and provide the conditions
for order-disorder transitions.
170
S4 P22
TEM CONTRAST IMPROVEMENT IN BUCK CELL SPERM SECTIONS
C.STEFANOV, S. ZAMFIRESCU, V.CIUPINA, I.M.OANCEA-STANESCU, A.C. ROSCA
Ovidius University of Constanta, Bd. Mamaia nr.124, 900527 Constanta, Romania, E-mail:
[email protected]; Email: [email protected]
This paper work presents possible options for people that operate with electronicmicroscope in order to obtain
images with enhanced resolution and contrast for experiments in biology domain. Diagnostic study of the cases
is related to the accurate identification of cellular components, their position in the cell and plasmatic membrane
integrity. In the experimental part of the paper work we presents the method of acquisition and multiple image
alignment (MIA = multiple image alignment), to obtain an image of the area of interest inside the spermatozoa.
The choice of operating parameters such as increasing the time of exposure, and so on are directly related to the
geometry of the cell. We have obtained an increase of contrast of 32% at a resolution of ~ 9nm using the MIA
compared with images obtained at a resolution of ~ 13nm..
S4 P23
CORRESPONDING MODELS FOR DANUBE RIVER STATE PARAMETERS DYNAMICS. CASE
STUDY THE GALATI AREA
Gabriel MURARIU, Paula POPA, Mihaela TIMOFTI, Marian BARBU
Physics, Chemistry and Environment Department, Faculty of Sciences and Environment, “Dunărea de Jos”,
Galaţi, România
The objective of this paper is to present and to validate a nonlinear dynamical model for Danube River state
parameters' records, based on the neural network approach. One measurable output was selected, namely the pH,
whose dynamics has an important role in the equilibrium of the buffer system as it was shown in previous
papers. A mechanistic dynamical model describing the interactions the chemical and physics parameters was
used for a LRS algorithm implementation. The promising results lead to consider a neural network approach.
The accuracy for prediction of the pH dynamics is better than 96 percent. Given its complexity, this approach
was made only for one parameter. In the future papers will be included an entire list of complete state
parameters.
S4 P24
INVESTIGATION OF THE HEAVY METALS CONCENTRATION DYNAMICS IN SURFACE
WATER AND SEDIMENTS FROM AQUATIC COMPLEXES SOMOVA-PARCHES
Gabriel Murariu, Adrian BURADA, Catalina ITCESCU, Catalina TOPA, Lucian GEORGESCU
Physics, Chemistry and Environment Department, Faculty of Sciences and Environment, “Dunărea de Jos”,
Galaţi, România
The objective of this paper is to present and to validate a nonlinear dynamical model heavy metals
dynamics in surface water and sediments from aquatic complexes Somova-Parches. The study is based on LRS
algorithm approach and, in the second stage on neural network method. The experimental data set cover a period
of 5 years and the measurements were made in sediments and surface water of 4 aquatic linked systems. The
promising results lead to consider a neural network approaching in order to investigate the heavy metals
concentration dynamics. The preliminary results are presented in this paper.
1
2
E. Bach, Information Processing Letters, 101(2007), 86-92
Barabasi A-L., Albert R., Science, 286 (1990), 509-512
3
Erdő Sciences,5 (1960) 17–16
Section 5 – ENGINEERING AND INDUSTRIAL PHYSICS
SECTION
S5 – Engineering and Industrial Physics
Physics of energy transfer, conversion and storage
Environmental Physics
Sensors and Device Physics
Micro- and Nanoelectronics
Microelectromechanical systems
Instrumentation and Metrology
Imagining, Microscopy and Spectroscopy and their applications
Instrumentation, processing, fabrication and measurement technologies
Applications of fluid mechanics and microfluidics
171
172
INVITED LECTURES
S5 L01
DESIGN OF NANOSCALED 1D AND 2D MATERIALS BASED ON TETRAOXA[8]CIRCULENE
MINAEV B. F., KARAUSH N. N., BARYSHNIKOV G. V., MINAEVA V. A.
Bohdan Khmelnytsky National University, blvd. Shevchenko 81, Cherkassy, Ukraine
The two-dimensional (2D) nanoscaled compounds 1–4 (Fig. 1) and nanotubes (1D) 5 (Fig. 2) based on the
tetraoxa[8]circulene species have been designed and described for the first time. The electronic structure and
spectra of the species 1–5 have been studied at the B3LYP/6-21G(d) level of the density functional theory (DFT)
[1] with the control of possible symmetry constrains.
The 2D sheets are absolutely planar aromatic compounds which exhibit the bending ability with the subsequent
spiralization and closing into the single-wall nanotube with the high symmetry (D8h symmetry point group,
diameter of 27 Å for the simplest nanotube based on the ribbon n×m = 2×8), according to a spiralization
mechanism (“cochlea” model) similar to the fullerenes formation mechanism [2]. This model predicts that the
initial planar heterocabon cluster like 2 is gradually growing (to the 2×8 size, for example) and finally get a form
of a curved sheet which is closed into the cylinder nanotube 5 (Fig. 2) to minimize the number of free vacancies.
Fig.
1.
The
structure
of
the
2D
tetraoxo[8]circulene sheets (n and m denote the
numbers of circulene fragments along the
horizontal and vertical directions, respectively).
Fig. 2. The optimized model of the single wall nanotube 5
(left – front view, right – side view) formed by the
spiralization of the tetraoxa[8]circulene sheet (n×m = 2×8).
The designed structures 1–5 are predicted to be extremely stable both in the thermal and kinetic aspects. They
are characterized by unusually strong light absorption in the visible region (around 500 nm) which is not typical
for the free tetraoxa[8]circulene molecule and other π-extended tetraoxa[8]circulenes. Such unusual strong
absorption of the compounds 1–5 can be assigned to the anthracene chromophore moiety formation upon
tetraoxa[8]circulene units conjugation. The increase of the visible absorbance with the growth of molecular
surface is in a good agreement with the acene chromophore dominant role.
The HOMO energy levels for the compounds 1–5 are relatively high (1, –4.99 eV; 2, –4.96 eV; 3, –4.95 eV; 4, –
4.94 eV; 5, –4.87 eV) and comparable with the corresponding values for the electron donating tetracene (–
4.86 eV), pentacene (–4.60 eV) and tetrabenzo[8]circulene (–4.84 eV) species [3]. Thus, we have predicted that
the 1–5 compounds can be considered as a good electron donor and implemented as the p-type semiconducting
material. The large cavities with a diameter of 6 Ǻ in the 2D sheets could be useful for the hydrogen storage
purposes like it was previously predicted for the layered octathio[8]circulene [4].
References.
1. A. D. Becke. J. Chem. Phys. 98 (1993) 5648.
2. H. W. Kroto, K. McKay. Nature. 331 (1988) 328.
3. Y. Sakamoto, T. Suzuki. J. Am. Chem. Soc. 135 (2013) 14074.
4. A. Datta, S. K. Pati. J. Phys. Chem. C. 111 (2007) 4487.
173
S5 L02
DEVELOPMENT OF HIGH SPEED AND HIGHLY SENSITIVE TERAHERTZ TIME-DOMAIN
SPECTROMETER
T. FURUYA 1, G. NIEHUES 2, S. TSUZUKI 1, S. OZAWA 1, S. AZUMA2, S. FUNKNER2
A. IWAMAE2, K. YAMAMOTO 2, S. NISHIZAWA 2 and M. TANI 2
1
2
Technical Division, University of Fukui, Japan, [email protected]
Research Center for Development of Far-Infrared Region, University of Fukui, Japan,
[email protected]
In the terahertz (THz) region (0.1 - 10 THz), a variety of spectra, such as due to vibrations of biological
molecules and rotations of gas phase molecules, are observed. In addition, THz electromagnetic waves are
transmitted through many industrial materials (for example, papers and plastics). Therefore, THz waves are
expected to be useful for non-destructive inspection and quality control of industrial products, such as medical
tablets, polymer products, and so on. THz time-domain spectroscopy (THz-TDS) is the one of the key
technologies for such applications. By using THz-TDS we can obtain absorption and dispersion spectra of the
targeted materials in the FIR/THz region faster than with the conventional Fourier-transform spectroscopy.
However, it is strongly desired to improve the speed and sensitivity of THz-TDS for realistic industrial
applications.
In this paper, we report some of our works to improve the speed and sensitivity of THz-TDS. One is a rapid
scan technique based on random sampling method. In recent years, rapid scan THz-TDS systems based on
asynchronous optical sampling1 and similar schemes were reported. In the past, we demonstrated a rapid scan
based on laser repetition- frequency modulation.2 However, the measurable frequency range with this technique
was limited below 100 GHz because of the laser timing jitter. As an alternative rapid scan technique in THzTDS, we recently suggested “random sampling”, where the probe optical pulses sample the THz signal with
random time-delay (caused by the laser timing-jitter) in every single sampling event. Another topic is detection
of THz wave by using “heterodyne” electro optical (EO) sampling3 and its sensitivity enhancement by using a
tapered metallic parallel plate waveguide (PPWG). Unlike conventional EO sampling, the heterodyne EO
sampling does not require any polarization optics (such as a waveplate). It has been demonstrated that the
heterodyne EO sampling signal can be enhanced by more than an order by using a tapered- PPWG coupled to the
EO sampling device (LiNbO3 crystal with a Si coupling prism).
Acknowledgements: This work was supported by JSPS KAKENHI Grant Number 25820139, 25286066 and
JSPS Bilateral Joint Research Projects.
References
1. T. Yasui, E. Saneyoshi and T. Araki, Appl. Phys. Lett. 87, 061101 (2005)
2. T. Furuya, et al, Jpn J. Appl. Phys. 52, 022401 (2013)
3. M. Tani, et al, Opt. Express 21, 9277 (2013)
174
S5 L03
PAPER AND PLASTIC-BASED WASTE NEUTRALIZATION USING MICROWAVE AND
ELECTRIC ENERGY
Sebastian POPESCU1 and Yasunori OHTSU2
1
Department of Physics, “Alexandru Ioan Cuza” University of Iasi, Romania
Department of Electrical and Electronic Engineering, Saga University, Japan
2
In the last decades the accumulation of paper and plastic-based waste permanently increased. Because of the
serious threats presented by these wastes to the land, air and underground water, a continuous search and effort
have been done in order to find an efficient alternative for their neutralization.
In the present talk two new cavity reactors will be presented. They were built by us in order to study their
advantages in waste management. The improvements made on them clearly showed that such devices represent a
good alternative to the traditional landfilling and/or incineration. The reactors operate with microwaves at
atmospheric pressure.
The first reactor was designed to neutralize paper-based waste, especially the contaminated products containing
paper, e.g. diapers. The constructive details of the reactor built by us and the thermal properties of the materials
used to build it will be presented. Additionally, some of the experimental results, obtained after the preliminary
tests, will also be presented. They prove the ability of this new device to neutralize definitively the type of waste
for which it was designed [1,2].
In order to cope with some of the various medical wastes, i.e. the plastic ones, as the disposable
syringes, another, smaller, reactor was built and its performances were assessed [2,3]. This reactor also used
microwave energy for heating the wastes, but also it can operate using a hybrid heating system, combining the
microwave energy with that obtained from an electrical heater. The purpose was to obtain a more uniform
heating inside the reactor, the maximal reduction of the waste volume and mass, a high enough temperature
necessary to destroy the microorganisms present in the waste, the decrease of the toxic gas emission level, as
well as the lowering of the cost per kilogram of treated waste. The design of the reactor also took into account
the easiness of operation and the safety of the personnel operating the device. The experimental results obtained
using this reactor are also presented, pointing out the advantages presented when the waste is heated solely by
microwaves or using the hybrid system (microwaves and the electrical heater).
These new types of reactors work without the need of oxygen injection, so the operation cost is
considerably lower than in the reactors already present in the medical facilities and in some of the facilities in
which the wastes from the retirement/nursing homes are processed.
References
[1].
S. Popescu, T. Misawa, Y. Ohtsu, H. Fujita, S. Sanematsu, Resources, Conservation and Recycling 52
(2008) 671–677.
[2].
Y. Ohtsu, R. Yamada, H. Urasaki, T. Misawa, S. Popescu, H. Fujita, J. Materials Cycles and Waste
Management 12 (2010) 25–29.
[3].
Y. Ohtsu, K. Onoda, H. Kawashita, H. Urasaki, J. Renewable and Sustainable Energy 3 (2011) 033106.
175
S5 L04
APPLICATIONS OF ELECTRON PARAMAGNETIC RESONANCE SPECTROSCOPY IN FOOD
SCIENCE
V.BERCU 1, C.D. NEGUT 2, O.G.DULIU 1
1.University of Bucharest, Faculty of Physics, P.O. Box MG-11, 077125 Magurele (Illfov), Romania
2.Horia Hulubei National Institute of Physics and Nuclear Engineering, P.O. Box MG - 06, RO-077125,
Magurele (Ilfov), Romania
In a global society in which the food trade is intensively used one of the main issues is represented by food
safely. The irradiation with high energy gamma rays represents the only method which can be used to
decontaminate raw food without unwanted effects on savor and texture. However, the effects of the ionizing
radiation are well know and for this reason all countries from European Union have their own set of rules
regarding the proper information of consumers about the use of this methods in the process of food
decontamination. Although there are more physical methods able to identify irradiated foods, accepted by
European Committee for Standardization (CEN) as European standards are Electron Paramagnetic Resonance
(EPR), Thermoluminescence (TL) and Chemiluminescence (CL). Among these EPR seems to be the most
adequate in the case of foodstuff containing a hard skeleton. Using the temperature and the irradiation dose
dependence of the EPR signal we have analyzed and characterized the free radicals produced in varies food stuff.
The methods used shows new features of the effects produced by the ionizing radiations.
S5 L05
WETTING LAYER CONTRIBUTION TO InAs/GaAs (001) QUANTUM DOTS NUCLEATION
1,2,3
.Gheorghe Valerica CIMPOCA, 1,.2.Oana Catalina BUTE,
1) Valahia University of Targoviste, Faculty of Science and Arts, 2 King Carol I Street , 130024
Targoviste, Romania. E-mail: [email protected]
2) Multidisciplinary Research Institute of Valahia University of Targoviste,13 Aleea Sinaia, Targoviste,
Romania, E-mail [email protected]
3) Academy of Romanian Scientists, Bucharest, Romania
We have followed by Atomic Force Microscopy (AFM) the complete evolution of InAs/GaAs (001) quantum
dots as a function of deposited InAs. In our paper we focus on InGa/GaAs (001) system as prototype of high
mismatch (7%). There are processes, such as, In segregation and Ga-In intermixing which can influence the
growth of InAs quantum dots (QDs) on the GaAs (001) surface. Thermodynamic and kinetic models show that
the formation of 3D QDs (as in the Stranski-Krastanow growth mode) takes place after the In concentration
reaches about 83%. Until this concentration the 2D growth is favored. However, we can’t talk about a pure
Stranski-Krastanow growth mode due to the substantial contribution of wetting layer (WL) and substrate to QDs
formation. A step erosion process by quantum dots nucleated at the step edges is evidenced. Analyzing the
quantum dots volume as a function of InAs coverage, we show that a surface mass contribution to quantum dots
formation exists. Analyzing the number density of QDs-down as a function of coverage and doing a comparison
between the quasi-3D QDs and 3D QDs number density, in the following, we’ll try to establish if the step
erosion process plays an important role in the 3D QDs nucleation.
Keywords: Quantum Dots, InAs/GaAs, AFM
176
S5 L06
DESIGNING THE PHOSPHORS OF FUTURE DOMESTIC LIGHTING
Harry RAMANANTOANINA,a Werner URLAND,a Fanica CIMPOESUB and Claude DAULA
a
Department of Chemistry, University of Fribourg, Chemin du Musée 9, 1700 Fribourg Switzerland, E-mail:
[email protected]
b
Institute of Physical Chemistry, Splaiul Independentei 202, Bucharest 060021, Romania
We deal with the computational determination of the electronic structure and properties of lanthanide ions in
complexes and extended structures having open-shell f and d configurations. [1,2] Particularly, we present
conceptual and methodological issues based on Density Functional Theory (DFT) enabling the reliable
calculation and description of the f - d transitions in lanthanide doped phosphors. We consider here the optical
properties of the Pr3+ ion embedded into various solid state fluoride host lattices, for the prospection and
understanding of the so-called quantum cutting process, [1,3] being important in the further quest of warm-white
light source in light emitting diodes (LED). We use the conceptual formulation of the revisited ligand field (LF)
theory, fully compatibilized with the quantum chemistry tools: LFDFT. We present methodological advances for
the calculations of the Slater–Condon parameters, [3] the ligand field interaction [4] and the spin–orbit coupling
constants, important in the non-empirical parameterization of the effective Hamiltonian adjusted from the ligand
field theory. The model shows simple procedure using less sophisticated computational tools, which is intended
to contribute to the design of modern phosphors and to help to complement the understanding of the 4fn - 4fn1
5d1 transitions in any lanthanide system.
[1] H. Ramanantoanina, W. Urland, F. Cimpoesu and C. Daul, Phys. Chem. Chem. Phys. 2013, 15, 1390213910.
[2] H. Ramanantoanina, W. Urland, A. Garcia-Fuente, F. Cimpoesu and C. Daul, Chem. Phys. Lett., 2013, 588,
260-266.
[3] H. Ramanantoanina, W. Urland, A. Garcia-Fuente, F. Cimpoesu and C. Daul, Phys. Chem. Chem. Phys.
2014, Accepted manuscript, DOI: 10.1039/C3CP55521F.
[4] H. Ramanantoanina, W. Urland, F. Cimpoesu and C. Daul, Phys. Chem. Chem. Phys. 2014, 16, 1228212290.
S5 L07
PROPERTY ENGINEERING WITH MODELING AND COMPUTATIONAL TOOLS. CHARGE
TRANSFER AND ELECTRONIC TRANSITIONS IN COMPLEX UNITS.
Fanica CIMPOESU
Institute of Physical Chemistry, Splaiul Independentei 202, Bucharest 060021, Romania
The modern computation machines are reaching a level that allows the use of first principles in the
rationalization of causal structure-property relationships, and, on this background, challenging the design of
special properties rated as desiderata of new technologies, at molecular and nano-scale. However, the task is not
simple, since implies the conceptual ordering and filtering of humungous numerical data provided by codes
working in different versions of electron structure theories. Methods like Density Functional Theory (DFT),
rather popular and accessible nowadays, have certain inherent limitations, particularized handling being
necessary,[1] in order to reach full interpretation power and to reach the outskirts of a domain dealing with the
prediction of the properties as proxy to experimental way to technologies. We show methodological advances
and application examples dedicated to the tuning of electron structure prerequisites in photovoltaic and lightemitting diode (LED) devices.[2, 3] Collaterally, the roles of spin states and spin coupling effects are discussed.
Phenomenological theories, such as two-state and ligand field models are used to descript in transparent way the
full-scale calculations, extracting the key parameters with relevance in material science entries.
[1] F. Cimpoesu, A. Zaharia, D. Stamate, P. Panait, C.I. Oprea, M.A. Girtu, M. Ferbinteanu, Polyhedron 2013,
52,183.
[2] H. Ramanantoanina, W. Urland, F. Cimpoesu, C. Daul, Phys. Chem. Chem. Phys. 2013, 15, 13902.
[3] H. Ramanantoanina, W. Urland, A. García-Fuente, F. Cimpoesu, C. Daul, Phys. Chem. Chem. Phys. 2014, in
press, DOI:10.1039/c3cp55521f
177
S5 L08
NEURAL NETWORK PROBLEMS IN LOW COST EMBEDDED SYSTEM
G. PRODAN,
Institute for Nanotechnologies and Alternative Energy Sources, Ovidius University of Constanta, Mamaia
Avenue No. 124, 900527, Romania
Implementation of neural networks in modern systems it is an open problem to finding solutions for calculating
algorithms, which areaccurate and fast at the same time. We meet every day with new systems in the form of
electronic gadgets, such as smartphones, TV, and so one that are able to interact with environment. Control
application of these devices isusually based on neural networks, capable to develop in relation to the work
environment. A disadvantage is that the implementation of such solutions can be achieved with a relatively high
cost, due to the computational power needed for application software that manages the operation of the system.
Thus, implementation of neural networks at the level of the low-cost platform, such as for example, Arduino
systems or those based on PIC microcontrollers, returns to find a simple algorithm, working in conditions of
limited resources (RAM/flash memory, working frequency, etc). The paper presents a way to implement neural
network in a simple systems, testing algorithms andtheir limitations for neural networks problem assets in lowcost systems. The chosen algorithms are based on the LUT (look up table) method, the Taylor expansion series,
and the CORDIC algorithm, to evaluate complex functions such as trigonometric functions, used in the
construction of the neural network. The Arduino UNO platform and PIC16F88 based system were chosen for
neural network implementation and testing.
Keywords: neural networks, CORDIC, embedded systems, microcontroller, low-cost
178
S5 L09
A COMPUTATIONAL STUDY OF DYE REGENERATION BY COBALT-BASED ELECTROLYTES
— APPLICATIONS TO DYE-SENSITIZED SOLAR CELLS
Corneliu I. OPREA,1 Anamaria TRANDAFIR,1 Adrian TRANDAFIR,1 Petre PANAIT,1 Fanica CIMPOESU,2
Daniela STAMATE,1 Marilena FERBINTEANU,3 and Mihai A. GÎRŢU1,*,**
1
Ovidius University of Constanţa, Constanţa 900527, Romania
Institute of Physical Chemistry, Bucharest 060021, Romania
3
University of Bucharest, Bucharest 020462, Romania
2
We report a computational study of the dye regeneration mechanism conducted on interacting cobalt redox
mediators and organic dyes and its impact on the performance of the corresponding dye-sensitized solar cells
(DSSCs). To begin with, we focus on two purely organic dyes, L0 and D35, which in conjunction with
cobalt(II) complexes [Co(terpy) 2]2+ and [Co(bpy-pz)2]2+, respectively, led to rather different regeneration and
device efficiencies.[1] Geometry optimizations performed using density functional theory (DFT) methodologies
show the redox complex present in the vicinity of the anchor group of L0 dye, or close to the alkoxy chains of
D35. We find that when the redox complex is located close to the binding group, the likelihood of the backtransfer from the semiconducting substrate to the dye is increased. The third dye we study is Y123, endowed
with long alkoxy chains, in conjuction with the heteroleptic complex [Co(phen) 2bpy]2+. Investigation of the
electron transfer from the cobalt electrolyte to the oxidized dye is performed by calculating reorganization
energies for high-spin and low-spin pathways, the latter being characterized by lower energy barrier. These
results allow us to draw structure-property relations required for further development of cobalt-based electrolytes
for DSSCs.
[1]
S.M. Feldt, P.W. Lohse, F. Kessler, M.K.
A. Hagfeldt, Phys. Chem. Chem. Phys. 15, 7087 (2013).
Nazeeruddin,
M.
Gratzel,
G.
Boschloo,
*Acknowledgments: The authors acknowledge the financial support received from SNSF and UEFISCDI under
the Romanian-Swiss Research Programme, through the grant RSRP #IZERO-142144/1 — PN-II-ID-RSRP1/2012.
**Email: [email protected], [email protected]
179
S5 L10
X-RAY FLUORESCENCE AND ATOMIC ABSORBTION SPECTROMETRY APPLIED IN THE
STUDY OF HEAVY METAL POLLUTION USING MOSS BIOMONITORING
I. V.POPESCU 1,3,4, C.STIHI1, C.RADULESCU1, A.GHEBOIANU2, I.BANCUTA2, I.DULAMA2
E.D.CHELARESCU4
1
Valahia University of Targoviste, Faculty of Science and Arts, Multidisciplinary Research Institute for Science
and Technologies, No 2 Carol I Street, 130024 Targoviste, Romania,
2
Valahia University of Targoviste, Multidisciplinary Research Institute for Science and Technologies, No 2
Carol I Street, 130024 Targoviste, Romania
3
Academy of Romanian Scientist, Bucharest, Romania
4
National Institute for Physics and Nuclear Engineering, Bucharest-Magurele,Romania
5
College Ienachta Vacarescu, Targoviste, Romania
The analysis of environmental samples for their elemental content is governed by the sample type, the element of
interest, the sensitivity, precision and accuracy needed and the availability of the technique. The choice of
multielement methods available includes inductively coupled plasma atomic emission spectrometry (ICPAES),
inductively coupled plasma mass spectrometry (ICPMS), X-ray fluorescence spectrometry (XRF), ion beam
analysis (IBA) [i.e. particle-induced X-ray emission (PIXE) and proton-induced gamma-ray emission (PIGE)],
nuclear activation analysis [neutron activation analysis (NAA), prompt gamma neutron activation analysis
(PGNAA), charged particle activation analysis (CPAA)], and several other methods, which are seldom used on a
routine basis. Some of these methods can be complemented by the use of monoelement techniques such as
atomic absorption spectrometry (AAS). Atomic Absorption Spectrometry (AAS) and Energy Dispersive X-Ray
Fluorescence (EDXRF) combined with biomonitoring methods were applied for determination of pollutant
heavy metals.These high sensitivity analysis methods were used to determine the elemental composition of some
samples of mosses, used as bioindicators, samples collected from different geographical areas with different
pollution industrial sources. We have studied the presence of elements such as Cd, Cr, Cu, Co, K, Fe, Mn, Ni,
Pb, and Zn in these environmental samples.The aim of this study was to assess the air quality in Romania using
terrestrial moss, to reveal highly polluted critical regions in the country in order to permanently survey the
degree of atmospheric pollution and to contribute to the European moss survey 2010/11 conducted under the
auspices of the UNECE ICP Vegetation covering some “white areas” in the map of atmospheric deposition of
heavy metals in Europe.
180
S5 L11
TUNING THE SIZE, SHAPE (PARTICLES AND FILMS) AND INTERACTIONS OF NANOSTRUCTUREDMATERIALS TO CONTROL THE PHOTOCATALYSTS BAND GAP AND
PHOTOCATALYTIC EFFICIENCY
B. COJOCARU,V.I. PARVULESCU
University of Bucharest, Department of Organic Chemistry, Biochemistry and Catalysis,
B-dul Regina Elisabeta 4-12, Bucharest 033016, e-mail: [email protected]
The degradation of the persistent pollutants from water and air is of major importance. However, this should be
done in a safety mode, without generating secondary pollutants that sometimes could be even more dangerous
than the initial pollutants. In this respect, photocatalysis may provide very elegant solutions.
To be successful a light quanta should contribute to the activation of molecular oxygen. This may efficiently
occur following different routes: (i) promotion of an electron from the valence to the conduction band in the case
of semiconductors, with an efficient separation of charges, or (ii) or by the transfers of the excess energy of an
excited sensitizer producing excited state singlet oxygen (1O2), and regenerating the ground-state sensitizer.
Singlet oxygen then reacts with the substrate to generate oxidized products.Surface plasmons may also
contribute in this activation process.
The use of nano-structures like nano-oxide semiconductor films, dispersed nano-oxides or dispersed nano-metals
represents modalities to enhance the electron transfer (Scheme 1).This presentation will provide examples on
how can be correlated tuning of the size, shape (particles or films) and interactions ofnano-structured materials
with a support with the band gap, and photocatalysis efficiency.
Scheme 1. Activation of oxygen and persistent molecules on supported nano-gold particles
1. D. Dumitriu, A. R. Bally, C. Ballif, P. Hones, P. E. Schmid, R. Sanjines, F. Levy and V. I. Pârvulescu,
Appl. Catal. B: Environmental, 25 (2000) 83-92.
2. B. Cojocaru, M. Laferriere, E. Carbonell, V.I. Parvulescu, H. Garcia, J.C. Scaiano, Langmuir, 24 (2008)
4478-4481.
3. B. Cojocaru, V.I. Parvulescu, E. Preda, G. Iepure, V. Somoghi, E. Carbonell, M. Alvaro, H. Garcia,
Environ. Sci. & Technol. 42 (2008) 4908-4913.
4. F. Lin, B. Cojocaru, C.-L. Chou, Ch.A. Cadigan, Y. Ji, D. Nordlund, T.-C. Weng, Z. Zheng, V.I.
Pârvulescu, R.M. Richards, ChemCatChem 5 (2013) 3841–3846.
181
S5 L12
DESIGNING NANO-BUILDINGS BASED ON TiO2-WO3-Au FOR PHOTOCATALYTIC
APPLICATIONS
Zs. PAP,1,2 V. DANCIU,1 G. KOVÁCS,1,2 and L. BAIA2,3
1
Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai University,
Arany János 11, 400028 Cluj-Napoca, Romania,
2
Faculty of Physics, Babeş-Bolyai University, M. Kogălniceanu 1,
400084 Cluj-Napoca, Romania.
3
Institute for Interdisciplinary Research in Bio-Nano-Sciences, Babes-Bolyai University,
Treboniu Laurian 42, 400271 Cluj-Napoca, Romania
The decomposition of phenol by photocatalytic means is a well-known issue. There are numereous types of
photocatalysts tht can be used to eliminate this pollutant from wastewaters, but the most important problem
comes from the phenol’s intermediates that appear during its degradation process, in different concentrations and
at different stages, and manifest different toxic effects to animals/humans and other organisms. Therefore, it is
necessary to find a liaison between the intermediates’ appearance and the fine structure of the photocatalysts. In
the last decades a large number of titania based composites were synthesized for improving the photocatalytic
performances. The critical role in getting progress in this issue is certainly played by the understanding of the
metal/semiconductor and semiconductor/semiconductor interfaces as well as of the composite’s structural and
morphological particularities.
For this reason, titania/tungsten (VI) oxide/Au composites with various amounts of the constituent oxides and
different porosities were synthesized by sol-gel method (with or without supercritical drying) followed by
selective noble metal photodeposition on the desired oxide’s surface (on TiO 2 or WO3 surface) and thermal
treatment. The noble metal particles’ localization was proved by scanning electron microscopy (SEM)/ energy
dispersive X-ray spectroscopy (EDX), while their size was obtained with the help of X-ray diffraction and
transmission electron spectroscopy (TEM). The influence of the tungsten oxide on the structural and
morphological properties of the composites was analyzed by performing X-ray photoelectron spectroscopy
(XPS), diffuse reflectance spectroscopy (DRS), extended X-ray absorption fine structure (EXAFS), Raman and
adsorption/desorption measurements.
Structural and morphological particularities derived from complementary information related to the structural
units of the constituent oxides, bond length and coordination number of the Ti and W atoms as well as the
influence of the selective Au deposition on the oxide network were acquired [1,2]. From the applicative
perspective an essential role is played by the selective deposition of Au on the oxide’s surface, and therefore, a
special attention was directed to the understanding of the changes related to the optical properties and surface
particularities of the obtained composites. Important changes of the titania and tungsten surface species,
depending on the deposition type and WO3 amount, were found. With the help of the achieved data, strong
correlations were made between the degradation intermediates and the materials’ fine structure, emphasizing the
importance of the careful design of ternary composites [1,2].
Acknowledgment: This work was supported by the grant of the Romanian National Authority for Scientific
Research PN-II-ID-PCE-2011-3-0442.
References
1. L. Baia, A. Vulpoi, T. Radu, É. Karácsonyi, A. Dombi, K. Hernádi, V. Danciu, S. Simon, K. Norén, S.E.
Canton, G. Kovács, Zs. Pap, Appl. Catal. B: Environmental, 2014, 148-149, 589-600.
2. G. Kovács, L. Baia, A. Vulpoi, T. Radu, T. Karácsonyi, A., Dombi, K. Hernádi, V. Danciu, S. Simon, Zs. Pap,
Appl. Catal. B: Environmental, 2014, 147, 508-5175.
182
S5 L13
RESEARCHES ON GALVANOMETER-BASED SCANNERS WITH APPLICATIONS IN
BIOMEDICAL IMAGING
Virgil-Florin DUMA
3OM Optomechatronics Group, Aurel Vlaicu University of Arad, Romania
[email protected]
We present several of our researches on galvanometer-based scanners (GSs) applied in one of the most dynamic
area of biomedical imaging: Optical Coherence Tomography (OCT) [1].
In the first part of the presentation the three most common input signals of GSs (i.e., sinusoidal, sawtooth, and
triangular) are investigated from the point of view of the effective duty cycle of the output signals (the scanning
functions) and of their capability to produce artifact-free images in OCT [2, 3]. Functional parameters like the
scan frequency and amplitude, as well as the theoretical (ideal) duty cycle are considered in the analysis. The
triangular input signal of the GSs is demonstrated to be best, while the drawbacks of the sinusoidal and sawtooth
input signals are discussed. OCT images show the capabilities of each scanning function of the GS.
In the second part of the presentation the more complex triangular input signals are studied: linear on the active
scan portion and with a designed non-linearity on the stop-and-turn portions. These non-linear portions are
explored theoretically in order to produce the maximum possible duty cycle of the scanning functions of the GS.
Thus, while in the literature linear plus sinusoidal signals have been considered best [4], we demonstrate that
actually the linear plus parabolic signals are those capable to produce the highest possible duty cycle of the GSs
[5].
A discussion on other aspects of our researches, such as optimized control structures of GSs, command
functions, and handheld scanning probes for OCT conclude the presentation [6, 7].
Acknowledgements. This work is supported by a Partnership grant of the Romanian Authority for Scientific Research,
CNDI–UEFISCDI project PN-II-PT-PCCA-2011-3.2-1682 (http://3om-group-optomechatronics.ro/).
References
[1] D. Huang, E. A. Swanson, C. P. Lin, et al., “Optical coherence tomography,” Science 254(5035), 1178-1181 (1991).
[2] V. F. Duma, K.-S. Lee, P. Meemon, and J. P. Rolland, “Experimental investigations of the scanning functions of
galvanometer-based scanners with applications in OCT,” Applied Optics 50(29), 5735-5749 (2011).
[3] V. F. Duma, J. P. Rolland, and A. Gh. Podoleanu, “Perspectives of optical scanning in OCT,” Proc. SPIE
7556, 7556-10 (2010).
[4] J. Montagu, “Scanners - galvanometric and resonant,” Chap. in Encyclopedia of Optical Engineering, R. G.
Driggers, C. Hoffman, R. Driggers, Eds., 2465-2487, Taylor & Francis, N.Y. (2003), DOI: 10.1081/E-EOE120009595.
[5] V. F. Duma, “Optimal scanning function of a galvanometer scanner for an increased duty cycle,” Opt. Eng. 49(10),
103001 (2010).
[6] V. F. Duma, “Command functions of open loop galvanometer scanners with optimized duty cycles,” Theoretical and
Applied Mechanics Letters 2(4), 043005 (2012).
[7] V. F. Duma, “Scanning in biomedical imaging: from classical devices to handheld heads and micro-systems,” Proc. SPIE
8925, 8925 0L (2014) - Invited.
183
ORAL PRESENTATIONS
S5 OP01
ANALYSIS OF PHYSICOCHEMICAL CHARACTERISTICS AND ELEMENTAL CONTENT OF
ROMANIAN HONEY DETERMINED BY AAS AND EDXRF SPECTROMETRY METHODS
Elena Daniela CHELARESCU
Horia Hulubei National Institute of Physics and Nuclear Engineering-IFIN HH, Reactorului Street, 023465
Bucharest - Magurele, Romania
Honey is a complex food with a content of more than 200 substances: is a source of food for human consumption
and with the multiple therapeutic effects, but may be a bioindicator of environmental pollution with heavy metals
[1, 2]. Average composition of honey is approximately 79.5% carbohydrate, 17.2% water and 3.3% other
ingredients in that are included and the chemical elements. [www.stavrofores.ro]. The honey composition is
influenced by the plant species (plant flowers), soil resources, environmental conditions and by the beekeepers,
the type of hive, honey extraction mode and processing. The honey commercially available in Romania markets
is of different varieties of high quality largely assessed by colour, density and flavour, but it is not free of trace
elements, including heavy metals. A deep control of honey quality from diferent romanian zone is very
important and necessary to verify compliance with quality specifications of the European Union [1].
The aim of this study was to characterise the samples of bee honeys (monofloral and multifloral) from some
geographical zone of Romania. Honey samples were collected in the summer of the years 2012 and 2013. For
this purpose physicochemical characteristics together with elemental content were evaluated. Physicochemical
parameters: pH, electrical conductivity, ash content, refractive index and water content, were analysed using the
Harmonised Methods of the International Honey Commission [3]. Concentrations of Al, K, Ca, Mn, Fe, Ni, Cu,
Zn, Mg, Cd, Cr and Pb in about 50 multifloral and monofloral bee honey samples collected from various
romanian zones, of different botanical origin , were determined by analytical techniques of high accuracy and
sensitivity:Atomic Absorbtion Spectrometry (AAS) and Energy Dispersive X-Ray Fluorescence (EDXRF)[4],
combined with Internal Standard Technique.
The results obtained indicate a good quality level that demonstrates an adequate extracting and processing of
Romanian honey. Moreover, the honey can be used to assess the pollution of the environment with heavy metals.
The research was performed in the frame of collaboration between Multidisciplinary Institute for Scientific and
Technological Research from Valahia University of Targoviste (ICSTM – UVT) and Horia Hulubei Institute for
Physics and Nuclear Engineering (IFIN-HH), Magurele, Romania.
Keywords: honey, physicochemical parameters, mineral elements, quality.
References
1. European Union Directive, Council Directive 2001/110/EC relating to honey (2002).
2. Alvarez-Suarez, J. M., Tulipani, S., Romandini, S., Bertoli. E., Battino, M.,
Contribution of honey in nutrition and human health:a review, Mediterr J Nutr Metab
(2010) 3:15–23.
3. Bogdanov S., Martin P. and Lüllmann C.: Harmonised methods of the European honey
commission. Apidologie (extra issue) 1-59 (1997)
4. Stihi, C., Radulescu, C., Busuioc, G., Popescu, I.V., Gheboianu, A., Ene., A.,
Studies on accumulation of heavy metals from substrate to edible wild
mushrooms, Romanian. Journal of Physics, Vol. 56, No.1-2, p.257-264, 2011
Acknowledgements for Dr. Claudia Stihi, Dr. Cristiana Radulescu, Lucia Toma and Andrei Chilian from
ICSTM-UVT for the support given in research achievement.
184
S5 OP2
FLUE GAS FILTRATION PREDICTION IN MICROFLUIDIC DEVICES USING
DIELECTROPHORESIS
Adrian NECULAE, Madalin BUNOIU, Antoanetta LUNGU, Mihai LUNGU
West University of Timisoara, Faculty of Physics, 4 V. Parvan, 300223 Timisoara, Romania
This contribution investigates the possibility to improve the filtering process of flue gas by controlling
entrapment of suspended nanoparticle using dielectrophoresis (DEP). A realistic description of the manipulation
process requires an accurate description of microchannel geometry and a precise evaluation of the DEP forces
spatial distribution. The work presents the results of a simulation study in order to characterize the functionality
of a 3D DEP-based microsystem for the selective manipulation of nanometric particles. The analysis focuses on
the nanoparticles having radii ranging from 50 to 150 nm, particles that cannot be filtrated by classical
techniques but have a harmful effect for environment and human health. The numerical solutions of the electric
potential, electric field, DEP force and particle concentration distribution for a typical separation device with
interdigitated electrodes array are calculated using the COMSOL finite element solver. The performances of the
device were analyzed in terms of a specific quantity related to the separation process, called Filtration and
Separation Efficiency. The simulations provide the optimal set of values for the control parameters of the
separation process, and aim to be useful in designing of microfluidic devices for separating nanoparticle from
flue gas.
Keywords: Air pollution, Flue gas filtration, Nanoparticle separation, Microfluidic device, Dielectrophoresis,
Separation Efficiency, Filtration, 3D numerical simulations.
Acknowledgments This work was supported by a grant of the Romanian National Authority for Scientific
Research, CNCS – UEFISCDI, project number PN-II-ID-PCE-2011-3-0762.
References
[1] M. Lungu,, A. Neculae, and M. Bunoiu, J. of Optoelectronics and Advanced Materials 12 2423-2426 (2010)
[2] R. Pethig, Biomicrofluidics, 4 022811-1 – 02281-34 (2010)
[3] A. Neculae, C.G. Biris, M. Bunoiu, and M. Lungu, J. Nanopart. Res. 14 1154-1165 (2012)
[4] N.G. Green, A. Ramos, and H. Morgan, J. of Electrostatics 56 235-254 (2002)
[5] H. Morgan and N.G. Green, AC Electrokinetics: Colloids and nanoparticles Research Studies ltd. Baldock,
Hertfordshire (2003)
185
S5 OP3
TIME DOMAIN AND SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY
EVALUATION OF DENTAL CERAMIC EMBEDDED DEFECTS
Cosmin SINESCU 1, Meda NEGRUTIU 1 , Florin TOPALA 1 , Adrian BRADU 2, Virgil-Florin DUMA 3* ,
Adrian GH. PODOLEANU 2
1
School of Dentistry, Victor Babes University of Medicine and Pharmacy of Timisoara,
Romania
2
School of Physical Sciences, University of Kent, Canterbury, U.K.
3
3OM Optomechatronics Group, Aurel Vlaicu University of Arad, Romania
*
Corresponding author: [email protected]
Introduction. Two in house built Optical Coherence Tomography (OCT) systems [1], equipped with handheld
scanning probes of our own design are being used to evaluate non-invasively dental constructs – for ceramic
prostheses. The brittle fracture of dental ceramics could affect the prosthetic treatment. These fractures occur
because of the unavoidable presence of microscopic flaws (micro-cracks, internal pores, and atmospheric
contaminants) produced during the cooling process. The compressive strength is typically ten times the tensile
strength. This makes ceramics good structural materials under compression, but not in conditions of tensile stress
(i.e., under flexure). Plastic deformation in crystalline ceramics is by slip, which is difficult due to the structure
and the strong local electrostatic potentials. There is very little plastic deformation before fracture. Therefore it is
important to detect the defects from the ceramic materials and to repair them. Non-invasive research methods are
essential to characterize the infrastructure of the fixed partial brides; it is thus possible to use the support after the
evaluation in order to make a good and more resistant dental bridge. The aim of this study is to analyze the
possible fractures in fixed partial dentures using OCT.
Materials and method. 54 metal ceramics and integral ceramic fixed partial dentures were investigated using en
face Time Domain (FD) and Spectral Domain (SD) OCT combined with a fluorescent method. 350 slices were
used for each set of investigation. The distance between the slices was 10 microns. A 3D reconstruction was
made for each investigation in order to evaluate the position and the magnitude of the ceramic defect.
Results. Using incisal scanning we found numerous pores which can cause fractures of the investigated dental
bridges due to their dimensions and positions. All the pores depicted are deep in the dental ceramic material;
therefore they cannot be detected via normal visual inspection. The material defects within the ceramic layers
have a large volume highly capable to generate fracture lines in the proximal or almost superficial on the
occlusal area, leading to the failure of the prosthetic treatment. The detection of these defects before inserting the
prostheses allows for corrections in order to avoid the fracture of the ceramic component. For a better
understanding of the ceramic defect spreading 3D reconstructions were developed.
Conclusions. Early detection of substance defects within the ceramic layers allows for optimal corrections
before inserting the prostheses and applying masticatory stress. For the embedded ceramic defects the en face
OCT non-invasive evaluation remains the only method capable to evaluate a prosthetic dental construct.
Acknowledgements. This work is supported by a Partnership grant of the Romanian Authority for Scientific Research,
CNDI–UEFISCDI project PN-II-PT-PCCA-2011-3.2-1682 (http://3om-group-optomechatronics.ro/).
[1] C. Marcauteanu, A. Bradu, C. Sinescu, F. I. Topala, M. L. Negrutiu, and A. Gh. Podoleanu, “Quantitative evaluation of
dental abfraction and attrition using a swept-source optical coherence tomography system,” J. Biomed. Opt. 19(2), 021108
(2014).
186
POSTERS
S5 P01
EVALUATION OF TRACE METAL BACKGROUND CONCENTRATION IN SOIL AND
SEDIMENTS IN LOWER PRUT WETLANDS
Oleg BOGDEVICH1, Dina IZMAILOVA1, Antoaneta ENE2, Elena CULIGHIN1
1
Laboratory of Geochemistry, Institute of Geology and Seismology, Academy of Sciences of Moldova, 3
Academiei St., Chisinau, MD-2028, Republic of Moldova
2
and Environment, 47 Domneasca St, 800008 Galati, Romania, e-mail: [email protected]
The evaluation of the background concentration of trace metals in soil and sediments is important for the
assessment of possible pollution from different sources. The Lower Prut wetlands are important areas with
nature parks and protected territories. In the last years these areas have been under the intensive impact from
anthropogenic sources: agriculture, transport, localities activity, unauthorized landfill and polluted sites, etc. The
Environmental Risk Assessment from some pollution sources should be made in order to take into consideration
a pollution level by different toxic substances including trace elements and persistent organic pollutants. The aim
of this study is the determination of the background concentration of trace elements in soil and sediments from
wetland area of Prut River, in the border region between Moldova and Romania.
The analysis of soil and sediments samples for the trace element determination was made by Atomic Absorption
Spectrometry method by flame and THGA technique (AAnalyst800). This analytical technique allows the
determination of Cu, Zn, Fe, Mn, Pb, Cd, Al, Ni, Co, Mo, Cr, As in different environmental media. The
background concentrations of the studied trace elements were obtained and compared with other regional
investigation and Clarke of chemical elements in different rocks. The general conclusion is that wetland area of
Prut River has a relative good ecological status regarding the trace element concentration in alluvial soil and
river sediments. The high level of trace elements can be determined near point pollution sources and agriculture
lands. The obtained results can be used for the Environmental Risk Assessment procedure in studied area.
This study work is carried out in the frame of Romanian-Moldavian-Ukrainian cross- border cooperation
(Project MIS ETC 1676) between Dunarea de Jos University of Galati, Institute of Zoology and Institute of
Geology and Seismology, Academy of Sciences of Moldova, and Ukrainian Scientific Centre for Ecology of the
Sea, for the complex investigation of toxic substances in terrestrial and aquatic ecosystems in Lower Danube
Euroregion.
Keywords: trace elements, AAS technique, alluvial soil, river sediments, wetlands, Prut River.
187
S5 P02
PREPARATION AND ANALYSIS OF FUNCTIONAL MATERIALS
M. LUNGU1, C. POROSNICU1, I. JEPU1, P. DINCA1, O. POMPILIAN1, C. DOBREA1,
T. CRACIUNESCU1, I. TISEANU1
1
National Institute for Lasers, Plasma and Radiation Physics, Magurele, jud Ilfov, Romania
W thickness(m)
During the last years, increased drastically the interest in the field of fusion nuclear energy. There is a great
interest in developing functional materials in order to resist to the high temperatures and nuclear irradiations. In
the proposed fusion reactor ITER, the first wall in a possible interaction with the fusion plasma will be realized
by a combination of bulk Be and W tiles, while the ASDEX Upgrade reactor is working with full tungsten wall.
In these conditions the erosion, deposition and the transport of Be, W and Ni/Mo (used as inter-layers) were
studied.
In this paper we report the studies on the marker tiles used in the JET reactor working with Be and W coated
tiles.
In order to determine the JET sample thickness we
prepared by thermionic vacuum arc (TVA) method W, Ni
and Mo etalon samples with known thickness, using
20
18
successfully an “in situ” quartz balance monitor for real
16
time estimation. The validation of the µ-X ray
14
fluorescence (µ-XRF) and high energy X ray fluorescence
12
(HEXRF) methods used for thickness measurements was
10
performed by analyzing the W and Ni films having 10 nm,
8
20 nm, 40 nm, 50 nm, 180 nm, 260 nm, 2.7 µm an
6
25
4
respectively 10 µm coated on silicon substrates and 0 nm,
20
2
4
15
20 nm, 40 nm, 50 nm and respectively 4.1 µm coated on
6
)
10
8
wid
10
(cm
fine grain graphite (FGG) substrates.
The methods
th(c
h
5
t
12
g
m)
14
len
were applied to measure about 20 samples used in the
3D mapping of a W coated marker tile
JET-ILW program. The primary parameters of the X-ray
source were chosen in relationship with the equipment
specifications at a working voltage of 100 kV and an anode current of 150 μA. A great advantage of this method
is the fact that the samples were measured in non-contaminating conditions, the samples were kept into the
original enclosures.
The sample thicknesses were compared with those obtained using SEM and GDOES (Glow Discharge Optical
Emission Spectroscopy) investigation techniques.
Acknowledgements: Funding by the Romanian National Authority for Scientific Research, UEFISCDI, through
project number PN-II-ID-PCE-2011-3-0522 is acknowledged.
188
S5 P03
METROLOGY AND OPTICAL PERFORMANCE OF OXIDE LAYERS PREPARED BY MODERN
TECHNIQUES
F. GAROI, V. R. MEDIANU, P. PREPELITA
National Institute for Laser, Plasma and Radiation Physics
409 Atomistilor Street, PO Box MG-36, Magurele 077125, Ilfov, Romania
Oxide layers (ITO and SnO2) was deposited onto glass substrate by modern deposition techniques. It was
obtained both from ITO (30 nm thickness) by vacuum thermal evaporation and from SnO 2 (30 nm thickness), by
rf magnetron sputtering.
The characteristics and metrology of the oxide depositions as well as the obtained layers were investigated.
Atomic force microscopy measurements show a roughness on the order of nanometers (3 nm) for the ITO and
AZO layers. Therefore, advanced metrology solutions for oxide layers applications are appropriate.
We conducted spectrophotometric investigations of these layers in the 0.2-1.8 μm wavelength range. A high
transmission in visible and near infrared range as well as a value of 3.70 eV and 3.75 eV for the energy band gap
(calculated from the absorption spectra) were particularly noted for these layers.
These results were analyzed along with the various metrology challenges. The present investigations of oxide
layers are also useful in applications of transparent conductive oxides.
S5 P04
TRACE METALS IN FISH FROM FRESHWATER ECOSYSTEMS OF LOWER PRUT NATURAL
RESERVE
Elena ZUBCOV1, Natalia ZUBCOV1, Antoaneta ENE2, Lucia BILETCHI1
1
Laboratory of Hydrobiology and Ecotoxicology, Institute of Zoology, Academy of Sciences of Moldova, 1
Academiei St., Chisinau, MD-2028, Republic of Moldova
e-mail:[email protected], [email protected]
2
and Environment, 47 Domneasca St, 800008 Galati, Romania, e-mail: [email protected]
The research on trace elements migration is considered to be one of the topical interests in modern hydrobiology,
ecology and hydrochemistry and has a great theoretical and practical significance. The development of the
theory on functioning of freshwater ecosystems is impossible without a proper understanding of the chemical
elements migration processes.
This work provides results obtained by the application of Atomic Absorption Spectrometry (AAS) technique for
the determination of trace elements in fish from Prut River and lakes from Lower Prut natural reservation,
Republic of Moldova.
The AAS method allowed the determination of chemical elements Cu, Zn, Fe, Mn, Pb, Cd, Al, Ni, Co, Mo, Cr,
V, As, Ti and Ag in different organs and tissues (skeletal muscles, liver, gonads, gills, skin and scales) of fish
from Cyprinidae and Percidae families.
Discussion is made on the differences in metal accumulation in fish tissues, which are conditioned by a complex
of factors determined by the intensity of plastic and generative metabolism of fish.
On-going work is carried out in the frame of Romanian-Moldavian-Ukrainian cross- border cooperation (Project
MIS ETC 1676) between Dunarea de Jos University of Galati, Institute of Zoology and Institute of Geology and
Seismology, Academy of Sciences of Moldova, and Ukrainian Scientific Centre for Ecology of the Sea, for the
investigation of complex relationship between water and sediment composition and accumulation of
microelements in fish body, for aquatic ecosystems in Lower Danube Euroregion.
Keywords: trace elements, AAS technique, fish, water, Prut River, Lower Danube Euroregion
189
S5 P05
IMPACT OF SPACE WEATHER EVENTS ON THE IONOSPHERE
H HARALAMBOUS , P VRYONIDES
Frederick Research Center Cyprus
The interaction between the Sun and upper atmosphere intensifies during space weather events such as CME
(Coronal Mass Ejections) and solar flares which significantly modify the spatial and temporal ionospheric
structure. This is reflected on ionospheric characteristics which exhibit excursions from their median behaviour
and therefore have to be studied in conjunction with the operation of technological systems that depend on or are
affected by the ionosphere. During the present solar cycle, that is currently undergoing its maximum activity
phase, a number of such events was registered and is presented along with a quantitative demonstration of their
effects on ionospheric characteristics such as electron densities and total electron content.
S5 P06
RADIOLOGICAL CHARACTERIZATION OF THE DECOMMISSIONED UNDERGROUND
RADIOACTIVE EFFLUENTS PIPES FROM THE IFIN-HH VVR-S NUCLEAR RESEARCH
REACTOR
Ioan Iorga1, Alexandru Octavian Pavelescu1, Mitica Dragusin1, Daniela Gurau1.
1
Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN HH
The IFIN-HH VVR-S Nuclear Research Reactor operated since 1957 until 1997. Decommissioning of the
reactor started in 2010 and will be completed in three phases until 2021. Due to the preparatory activities (sitting,
authorization and building) for the European Light Infrastructure - Nuclear Physics Facility (ELI-NP) built in the
vicinity of the reactor, it was necessary to remove the underground pipes of the reactors. The reactor was fitted
with a 30 m3 radioactive effluents leakages pond connected by an underground pipe with two 300 m3 radioactive
effluents storage ponds belonging to the IFIN-HH Radioactive Waste Treatment Plant (STDR). The following
pipes were decommissioned: a radioactive effluent transporting stainless steel pipe, a ventilation carbon steel
pipe for the 300 m3 ponds and a ventilation carbon steel pipe for the exhausted filter. Radiological
characterization was carried out for pipes discharged from the site, including soil, cutting mixture and pipe smear
samples. There have been two types of measurements: indirect measurement of beta-gamma contamination by
sampling smears and gamma spectrometric analysis to determine the specific activity of the samples.
Key words: nuclear decommissioning, contamination, gamma spectroscopy, soil samples, pipe samples
190
S5 P07
SOIL CHEMICAL POLLUTION REFLECTED IN GROUNDWATER ELECTRICAL PROPERTIES
SERBAN Adrian1, IOANE Dumitru2, CHITEA Florina2,3
University of Bucharest, Faculty of Physics1
University of Bucharest, Faculty of Geology and Geophysics2
Geodynamics Institute of Romanian Academy3
Soil affected by stock or fund pollutants can be evaluated by specific chemical and physical analyses. In many
cases there is the need to transfer the chemicals (absorbed by the solid matrix or trapped in soil micro or macro
pores) from solids into aqueous phase, in order to be able to evaluate their presence and concentration. In this
study, two types of pollutants effects were analysed: salty water and hydrocarbons. According to their electrical
properties, the salty water is classified as a very good electrical conductor while crude oil and most of the
petroleum derivate products (fuels, oils), in normal conditions, behave as electrical insulators.
In a test area, bulk electrical conductivity was determinate by in-situ measurements. Measurement were made on
25m long profiles by inducing very small electrical “eddy” currents in the ground and measuring the magnetic
field generated by these currents. The quad-phase results were used to analyse the soil electrical conductivity
variation. By means of the indirect method of investigation an area characterized by high salinity > 260 (mS/m)
was detected. Also a 10m x 5m area characterized by low electrical conductivity values (< 130 mS/m) was
delineated in the resulted map.
Based on these observations, small depth boreholes (2-3m) were projected and executed. Water and soil samples
were extracted and analysed in laboratory conditions. Evaluating the total hydrocarbons (THP) results, it was
noticed that the high values correspond to the area characterized by low quad-phase values. In all investigated
area a high content of chlorides was detected, exceeding even the imposed limits for the discharged waste
waters. Chloride concentration is extremely high (> 1200mg/kg solid substance) in the electrical conductive area
observed by electromagnetic investigation method.
In a few hours, groundwater accumulated into the drilled boreholes. By using a 1.5m special dropper, water
samples were obtained and then analysed in laboratory. Total dissolved solids (TDS) high values correlated well
with the high electrical conductivity anomaly, while lower TDS values were noticed for the sample extracted
from the hydrocarbon highly polluted area.
By integrated evaluation of all results it was concluded that the high conductivity area observed by
electromagnetic measurements is closest to the pollution source. The contaminant spreads both laterally and indepth, as shown by TPH and chloride measurements on soil samples. As we move away from the source
groundwater conductivity decreases (less chloride content), but soluble hydrocarbons presence is still at a high
rate. Therefore, by analysing ground water electrical properties salty water pollution can be evaluated, while
hydrocarbons pollution needs to be assessed either by measuring bulk soil conductivity or by specific chemical
analyses.
191
S5 P08
HYSTERESIS ANALYSIS IN LITHIUM-ION BATTERIES
Flavian Mihai ZACREŢCHI1, Alexandru STANCU1
1
Faculty of Physics, Alexandru Ioan Cuza University of Iaşi, 11 Boulevard Carol I, 700506 Iaşi
Energy storage systems have a very important role in industry, economics and science, Lithium-ion battery being
one of the most promising technologies for this field. Providing a performance battery management system
(BMS) is one of the most important goals which needs to be achieved in order to obtain better results in real
world application (like Electric Vehicles –EV).
This paper aims at investigating the hysteresis in the relationship between state-of charge (SOC) and open-circuit
voltage (OCV) of lithium batteries in order to obtain a performance model able to be used in online applications
by battery management systems.
The measurements have been carried out using a Volta Potentiostat controlled with a PC software able to
generate cycle charging/discharging scenarios and to acquire data like voltage, current and temperature.
Using an old battery it was really easy to observe a considerable improvement of its performance after first 5
recharging cycles: the real capacity was raised, the yield in charging process passed over 50% and the SOCOCV static characteristic exhibits a more compact hysteresis cycle.
A new, unused battery was used for exploring the hysteresis in different discharge/charge loops of different
sizes, each one included in the other, having as the major loop, the one which is obtained over a complete
discharge/charge cycle of the cell. The obtained results showed that in the 20%-80% region of SOC, the
hysteresis presents a flat characteristic, having just a small variation of OCV.
From all the experiments, it can be concluded that the relaxation time has a big influence on battery
performances, and the behavior of such a system presents a time dependent characteristic. Using the
experimental results, a theoretical model which should be able to describe the evolution of the batteries in
online-systems can be developed. This model can be used in further battery management systems (BMS).
References:
[1] F. Baronti, W. Zamboni, N. Femia, R. Roncella, R. Saletti, and W. Zamboni, Proc. of the IEEE IECON 2013,
6728 – 6733.
[2] X. Tang, X. Mao, J. Lin, and B. Koch, American Control Conference (ACC) 2011, 941 – 946.
[3] M. A. Roscher, O. Bohlen, and J. Vetter, International Journal of Electrochemistry 2011, p1(6).
192
S5 P09
MATERIALS CHARACTERIZATION USING X-RAY TECHNIQUES
Antoaneta ENE1, Marina V. FRONTASYEVA2, Oleg V. IGNATENKO3, Constantin GHEORGHIES1
1
Dunarea de Jos University of Galati, Faculty of Sciences and Environment, Department of Chemistry,
Physics and Environment, 47 Domneasca St, 800008 Galati, Romania,
e-mail: [email protected], [email protected]
2
Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 141980 Dubna, Moscow
Region, Russia, e-mail: [email protected]
3
Scientific and Practical Materials Research Centre of NAS of Belarus,
P. Brovka St., 19, Minsk, 220072, Belarus, [email protected]
This work provides results obtained by the application of X-ray based techniques for the microcomposition and structure characterization of industrial metallurgical samples and new synthesized materials,
such as lithium and boron nitrides and diamonds, obtained at National Academy of Sciences of Belarus. The
techniques employed are scanning electron microscopy coupled with energy dispersive X-ray analysis (SEMEDX) and X-ray Diffraction (XRD).
Application of SEM-EDX using a Quanta 200 FEI type scanning electron microscope for the
investigation of micro-composition of metallurgical samples allowed the determination of chemical elements in
industrial samples (B, C, O, La, Ga, Mo, Pr, Rh, Na, K, Mg, Al, Ti, Si, V, P, Nd, Ca, Cr, Ni, Cu, Sm, Mn, Fe,
Co, Zn) and of impurity content in Li3N samples (Na, Fe, Cl, Zr), besides the transformation of lithium nitride
into carbonate with increasing synthesizing pressure. XRD technique using a DRON-3.0 diffractometer (Cu-Kα
radiation) was employed for the evaluation of size and shape of crystalline phases, transformation of phases
during activation processes, lattice parameters, and mineralogy in different materials.
On-going work is carried out in the frame of Romanian-Russian collaboration between Dunarea de Jos
University of Galati and Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research (JINR),
Dubna, Russia, by using SEM-EDX and XRD for the investigation of microstructure and micro-composition of
crystalline diamonds and of lithium and boron nitrides synthesized in different nitrogen pressure conditions and
mechanically activated for different periods.
Keywords: Li-N, B-N, XRF, SEM-EDX, XRD.
193
S5 P10
THERMODYNAMIC CONFIGURATIONS ASSOCIATED WITH HEAVY RAINFALL IN THE
BARLAD RIVER BASIN
Daniel CARBUNARU1, Sorin BURCEA1
1
National Meteorological Administration, Bucharest, Romania
Lately, heavy rainfall events associated with severe weather have produced significant damages in various
regions of Romania. Among the areas most at risk from floods are those found in river catchments. This study is
focused on Bârlad River Basin, and aims at revealing thermodynamic configurations characteristic to severe
weather events.
The analysis revealed various synoptic baroclinic configurations and their characteristics associated with rainfall
exceeding 20 l/m2 in Bârlad River Basin. Considering the evolution of baroclinic waves, which are
predominantly from west to east, a synoptic domain was chosen. Fig.1 illustrates this domain, extending at
European level and not centered on Romania. The choice of this domain highlights the evolution of troughs with
different amplitudes and wavelengths toward Romania in relation to mean tropospheric circulation existing at
European level. Horizontal expansion is approximately 6670 km and, thus, for the average speed of 10 m/s in
troposphere, we have a Rossby number of about 0.15 units (an order of magnitude smaller than 1).
Fig.1 Synoptic domain used for the analysis.
Within this study, 62 days were investigated using both reanalysis (NCEP/NCAR) and radar data. The radar data
was provided by the WSR-98D S-band Doppler system from Barnova (Iasi County). The days to be investigated
were chosen such that both datasets were available. The days were afterwards clustered using the extended EOF
(Empirical Orthogonal Functions) analysis performed on daily average geopotential field at 300 hPa, 500 hPa
and 850 hPa. Since the first three eigenvectors explain about 73% of the data, the clustering was done by
projecting their positive and negative values on the data, resulting eight classes. For each of these eighth classes,
the daily averages of geopotential and the relative geopotential field heights were obtained, highlighting the
various dynamic and thermodynamic features. From radar data maximum heights of radar echoes ET (Echo Tops
- km) and the amount of precipitable water in a vertical column VIL (Vertical Integrated Liquid – kg/m2), for
each class were calculated. For two points located in the northern and southern parts of Barlad River basin (A1
and B1, Fig.1) instability indices like Total Total Index, K Index and SWEAT Index were calculated. This was
performed to observe the vertical thermodynamic structure near the basin for each class.
194
S5 P11
DIRECT AND INDIRECT METHODS FOR ASSESING AN OIL POLLUTED SITE
SERBAN Adrian1, CHITEA Florina2,3, IOANE Dumitru2
University of Bucharest, Faculty of Physics, P.O.BOX MG-11, Magurele, Bucharest, Romania1
University of Bucharest, Faculty of Geology and Geophysics2
Geodynamics Institute of Romanian Academy3
Standard analysis for hydrocarbon pollutions consists in laboratory determination of volatile compounds or total
hydrocarbons (direct method). Such methods allow precise evaluation of local effect produced by the pollutant,
but are time-demanding and expensive to apply in cases of long – term activity of the contaminant source.
If surface spills occur, hydrocarbons will start a lateral migration and a downward movement. In depth extension
will be limited by the aquifer, as a consequence of density differences between the water (≥ 1g/cm 3) and
pollutant (< 1g/cm3). Groundwater will also act as a transporter for the pollutant, extending the environmental
problem through great distances from the source. Therefore, for large affected areas evaluation by an indirect
method (geophysical investigation) should be included in the investigation program.
In an area severely affected by oil contamination, direct and indirect methods were used in order to evaluate their
applicability. Samples of free phase hydrocarbons and water were extracted from the studied area, from 5m
depth. The results obtained using both methods showed that the pollutant can be described as electric insulator.
In contrast with hydrocarbons electrical properties, the ground water is considered to be electrically conductive.
The indirect investigation method consisted in non-invasive in-situ measurements of electrical properties of soil
and groundwater. This parameter was chosed based on professional and scientific reports, as well as on data
obtained on samples.
High contaminated zone
Low contaminated zone
a)
b)
Fig. 1 - Apparent electrical resistivity results obtained by indirect investigation method:
chart with variation of measured parameter with depth (a); sections showing lateral and in depth variation of
pollutant as resulted from electrical resistivity data (b)
Results presented in Figure 1 showed that the indirect method is efficient in the investigation of such
environmental problems, but data interpretation is significantly improved when information from direct methods
are also available.
195
S5 P12
MONITORING OF SLUDGE FROM WASTEWATER TREATMENT PLANTS IN DAMBOVITA
COUNTY: DETERMINATION OF HEAVY METALS CONCENTRATIONS BY ANALYTICAL
METHODS
R. BANCUTA1, I. BANCUTA2, R. SETNESCU2,3, A. CHILIAN2, T. SETNESCU2,3, I. V. POPESCU2,4, A.
GHEBOIANU2, O. CULICOV3,5
1
The Water Company from Targoviste, Dambovita County, 130055, Romania
Targoviste, Romania
3
R&D Institute for Electrical Engineering, Department for Advanced Materials, 313 Splaiul Unirii, Bucharest
030138, Romania
4
Academy of Romanian Scientists, 050094, Bucharest, Romania
5
JINR Dubna, Moscow Region, Russia
2
Abstract: Most wastewater treatment processes produce a sludge which should be disposed off. The sludge is
referring to the residual semi-solid material left from industrial or domestic wastewater or sewage treatment
processes. Land application of raw or treated sewage sludge can reduce significantly the sludge disposal cost
component of sewage treatment as well as providing a large part of the nitrogen and phosphorus requirements of
many crops. However, this sludge contains also heavy metals. Some heavy metals from sewage sludge are
accumulating in soils after successive sludge applications and can be toxic to plants, soil organisms, as well for
humans and animals along the food chain. Therefore, great importance is the monitoring of the heavy metal
content. In this paper, it has been represented the levels of heavy metals in sludge collected from five towns of
Dambovita County, Romania. The analyses have been performed using Atomic Absorption Spectrometry (AAS)
and Energy Dispersive X-Ray Fluorescence (EDXRF).
Keywords: wastewater, sewage sludge, heavy metals, EDXRF, AAS
196
S5 P13
HIGH POWER TAPPED-INDUCTOR LED ARRAY DRIVER
Marius APETREI 1, Adrian GEORGESCU 2, Grigore FETECĂU 3
1
Department of Physics, Ovidius University of Constanţa, Constanţa, 900527, Romania
School of Engineering and Computing Sciences, Texas A&M University of Corpus Christi, Corpus Christi,
78412, Texas, United States of America
3
School of Computing Sciences, Electrical and Electronics Engineering, Dunărea de Jos University of Galaţi,
Galaţi, 800210, Romania
2
Keywords: LED, array, driver, tapped-inductor, buck, converter, high efficiency
Over the last years there has been a constant increase in the number of Light Emitting Diodes (LED) applications
because of their small weight, low power consumption and low operating temperatures. Developments in the
manufacturing technology have pushed the luminous efficacy far beyond the 100lm/W boundary. With the
introduction of multi-chip LED arrays the assembly cost has decreased, allowing luminaire manufacturers to
provide high lumen output from compact light sources at affordable prices. It is predicted that over the next years
the use of LEDs in the lighting and consumer sectors will continue to grow with an estimated annual compound
rate of 19%. In order to benefit from these improvements in LED technology, the driver also plays an important
role in the total system efficacy.
The present paper covers the design, fabrication and testing of a high power tapped-inductor buck converter
especially suited for use in luminaires employing LED arrays. Compared to conventional buck drivers, which
regularly attain efficiencies between 82 and 86%, the proposed circuit has a minimum efficiency of 90% and a
peak efficiency of 92,1%. The goal was obtaining maximum conversion efficiency at a low cost and using
widely available components. The only custom component is the ferrite core tapped-inductor.
The proposed circuit has a maximum output power of 120W and can be used with current type LED arrays. It is
also suitable for powering a series string of high power LEDs provided that the string voltage and current needs
are met. The driver is flexible, allowing a range of output voltages ranging from 20V to 45V. The output current
can be preset between 1A and 4A. Load current regulation is better than ±1,2% over the whole output voltage
range and better than ±4,4% over the 0ºC to 50ºC ambient temperature range.
The driver operates from a wide range, high voltage, direct current input bus (between 280 – 420V) using pulsewidth-modulation at a nominal frequency of 132kHz. The oscillator frequency is dithered ±4kHz with 250Hz for
easier EMI compliance and reduced input filter cost.
The TopSwitch-GX integrated circuit from Power Integrations provides the necessary control functions
and also integrates a high voltage MOSfet for lower cost. By careful component selection, optimisation of the
tapped inductor turns ratio and losses distribution a high efficiency is achieved. A low value resistor is used for
output current sensing in order to reduce power losses as much as possible. The low-current operational
amplifier and optocoupler buffer reduce low-load losses by minimising the power requirement of the control
circuit. The power consumption is further reduced at low load by a linear reduction of the converter operating
frequency. A non-dissipative snubber recycles the leakage inductance energy to the power supply output bus.
The converter prototype has a small footprint (overall dimensions 88*68*35mm) and includes protections
against input undervoltage and overvoltage, output overvoltage, output short-circuit and over-temperature,
providing a good reliability. Because of the high efficiency it requires minimal external heat sinks for this power
level.
197
S5 P14
THERMAL PROPERTIES OF NANOSCOPIC DETECTORS
Dragos-Victor ANGHEL
Horia Hulubei National Institute of Physics and Nuclear Engineering
To achieve the desired performances, ultra-sensitive detectors of electromagnetic radiation are nanoscopic in size
and operate at sub-Kelvin temperatures. They consist of several layers of different materials tailored by vapor
deposition and electron beam lithography. At such low temperatures and dimensions, the finite size effects play a
major role and the physical properties of the detectors or of the detectors' parts are qualitatively different from
those of macroscopic objects.
In this presentation I show the principle of operation of such a detector and I discuss different models for the
calculation of its characteristics and thermal properties. Then I focus on the glassy properties of the detector's
components and the difficulties met in their interpretation by the standard macroscopic theories. I adapt these
models to our type of systems, I calculate the thermal properties I need, and I investigate the accuracy of some
old paradigms in the field of glassy materials.
S5 P15
SOME FERROSPINEL NANOPOWDERS FOR CATALYST APPLICATIONS
E. REZLESCU1, C. DOROFTEI1,2, N. REZLESCU1, P.D. POPA1, M. IGNAT3
1
Institute of Technical Physics, 47 D. Mangeron Blvd, 700050 Iasi, Romania.
“Al. I. Cuza” University, Faculty of Physics, 11 Carol I Blvd, 7000506 Iasi, Romania.
3
“Al. I. Cuza” University, Faculty of Chemistry, 11 Carol I Blvd, 7000506 Iasi, Romania.
2
The purpose of this work was to find new ferrite compositions with suitable properties for catalyst applications.
Spinel-type ferrite nanopowders of chemical composition Me xFe3-xO4 (x = 1 for divalent metal, Me = Mg, Co,
Ca and x = 0.5 for monovalent metal Me = Li) were prepared through sol-gel-self-combustion procedure. Some
structural and morphological aspects of the four-ferrite nanopowders were investigated to clarify how
compositional changes affect properties and characteristics of ferrites.
X-ray diffraction (XRD), nitrogen adsorption by BET, scanning electron microscopy (SEM) and energy
dispersive X-ray (EDAX) techniques were used to investigate the structural and chemical properties. The
catalyst activity of the ferrite powders was tested. It is known that the starting temperature for combustion
reaction of volatile organic compounds (VOC) depends on the composition of the catalyst and the nature of the
compound to be oxidized [1,2]. The minimum temperature of the catalytic combustion reaction of diluted gases
(ethanol/air, methanol/air and acetone/air) over ferrite nanopowders catalysts was determined and the effect of
Me-type was analyzed.
Acknowledgements: This work was performed by financial support of the Project PN-II-ID-PCE-2011-3-0453,
CNST-UEFISCDI.
References
[1] V.R. Choudhary, S. Banerjee, S.G. Pataskar, Appl. Catalysis A-General 253 (2003) 65-74.
[2] P.O. Thevenin, P.G. Menon, S.G. Jaras, Cattech 7 (2003) 10-22.
198
S5 P16
EVANESCENT-WAVE CAVITY RING-DOWN SPECTROSCOPY SYSTEM FOR GASES
MONITORING
Costel COTIRLAN-SIMIONIUC, Rodica GHITA, Catalin Constantin NEGRILA, Constantin LOGOFATU
National Institute for Materials Physics, 105 Bis Atomistilor Street, P.O. Box MG-7, 077125, BucharestMagurele, Romania
A new configuration of spectroscopic system is used to analyse and record gas emissions. The nitrogen oxides
(NOx) are exhaust emissions of a car that have an adverse effect on health. Both gasoline and diesel engines
produce nitrogen oxides from the burning of air-fuel mixture. Due to the operating principles of the engines and
different characteristics of the two fuels, the emissions of NOx are different. The evanescent-wave cavity ringdown spectroscopy (EW-CRDS) technique can detect gas molecules located in the evanescent-wave (EW) field
of spectroscopic system: NO2 with absorptions in 425-460 nm and 562-582 nm spectral ranges, respectively NO3
with absorption in 655-670 nm spectral range. The EW field is more extended if the incidence angle α is closer
to the critical angle of total internal reflection.
Results for testing of system are presented for exhaust gases from gasoline engine and Diesel engine.
EW field
Gases output
Gases input
EW-CRDS input mirror
Laser
EW-CRDS output mirror
α α
Δα
Δα
PMT
EW-CRDS
Monitor
Fig.1 EW-CRDS system for gases monitoring
199
S5 P17
ESTIMATION OF THE THERMAL STRESS INDICES IN ROMANIA FROM THE LARGE-SCALE
PREDICTORS
Andreea DOBRINESCU1,2, Aristita BUSUIOC1
1
National Meteorological Administration, 97 Sos. Bucuresti-Ploiesti, Sect. 1, Bucharest, Romania
University of Bucharest, Faculty of Physics, P.O.BOX MG-11, Magurele, Bucharest, Romania
2
Temperature extremes have a great impact on the society. The future climate change scenarios based on global
climate models project significant increase in temperature extremes in the next decades. There are some
complex indices quantifying the direct discomfort felt by human body and they were less analysed so far. Two of
such indices are known: heat index corroborating the air temperature with the relative humidity (ITU) specific
for the summer season; for winter, a cooling index (IR) is dependent on air temperature and wind speed. The IR
was calculated at 61 stations while ITU was calculated at 87 stations, uniformly distributed over the Romanian
territory. The information supplied by the global climate models (GCMs) are too coarse (about 100 km) to
calculate these indices for practical needs. There are two techniques to derive information on higher spatial
resolution, usual known as downscaling: dynamical downscaling given by the regional climate models (RCMs)
that are nested in the global climate models and statistical downscaling (SD) techniques that are based on
statistical relationships between local variables of interest and large-scale variables (predictors). The large-scale
predictors should well simulated by GCMs. The two downscaling techniques have advantages and disadvantages
and they are used as complementary techniques. The SD models have the advantages to be less costly and easier
to apply, compared to the RCMs that are very costly because they need very powerful computers.In this paper a
SD technique is proposed to estimate the two stress indices (predictands) from the large-scale predictors that are
usually well simulated by the GCMs. The SD models are based on the canonical correlation analysis (CCA).
Before the CCA, the predictors and predictands are transformed to anomalies (by subtracting the long term
mean) and then are projected on their EOF (empirical orthogonal functions). The most important EOFs
(explaining the most part of the observed variance) are retained for the CCA model. The air temperature at 850
hPa (T850), sea level pressure (SLP) and specific humidity at 700 hPa (SH700) have been considered as
predictors for the two predictands. It was found that the T850 alone is a very good predictor for both indices, the
model performance (represented by the correlation between estimated and observed values, as well as by the
explained variance of estimated values from the total observed variance) being very high for all stations. The
combination between T850 and SLP (for IR) or SH700 (for ITU) increases a little the model performance only
for ITU, while for IR the model performance is increased only for a few stations (fig.1). These results show that
the statistical model presented in this paper can be used in the future to project the future ITU/IR changes on
station scale in Romania using the climate change GCM simulations.
100
100
80
80
60
60
40
40
20
20
0
1
6 11 16 21 26 31 36 41 46 51 56 61
0
1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86
Figure 1. Correlation coefficients (*100) between the estimated and observed anomalies for IR (left) and ITU
(right) for the independent interval 1991-2010 with the SD model calibrated over 1961-1990 (station values).
200
S5 P18
SPATIAL AND TEMPORAL CHARACTERISTICS OF SEASONAL WIND SPEED VARIABILITY IN
ROMANIA
Lenuta MARIN1,2, Marius-Victor BIRSAN1, Alexandru DUMITRESCU1, Aristita BUSUIOC1
¹) Meteo Romania (National Meteorological Administration), Bucharest, Romania.
²) Faculty of Physics, University of Bucharest, Bucharest, Romania.
The empirical orthogonal function (EOF) technique has been used to reveal the main characteristics of the spatial
and temporal variability of the seasonal (average) wind speed from 104 meteorological stations fairly spreaded
over Romania. The analysis was conducted for the 1961-2010 period, using all time series with continuous and
homogenized records from Meteo Romania. The main mode of spatial variability is given by the first EOF
pattern (EOF1) and the main characteristic of temporal variability is given by the temporal coefficient associated
to EOF1 (PC1). The most important modes are EOF1 and EOF2. It was found that, for all seasons, the EOF1
exhibits the same sign of variability over the entire counttry, with the highest magnitude over the eastern and
southwestern regions and lowest over the intra-Carpathian area. This result shows that a large-scale mechanism
controlls the seasonal wind variability in Romania and this is represented by the the surface circulation
quantified by the sea level pressure (SLP) variability. PC1 exhibits a significant downward trend for all seasons,
with highest rate for winter (0.26 m/s per year) and lowest for summer and autumn (0.16 m/s per year). As an
example, Figure 1 shows EOF1 and PC1 for winter. To understand the physical reasons for this behaviour, a
correlation analysis between the principal components of SLP and wind speed has been carried out. For all
seasons, a negative correlation between the aforementioned variables was found. Considering the (positive) sign
of SLP EOF1 pattern, it was found a SLP PC1 increase (significant for winter and spring), which suggest an
increase in the frequency of anticyclonic patterns covering Romania, leading to a decrease in wind speed. These
results are in good agreement with the recent findings of decreasing trends in wind speed in Romania.
Figure 1. Spatial (EOF1) and temporal evolution (PC1) of wind speed for winter season.
201
S5 P19
LESSONS LEARNED ON RADIOLOGICAL EQUIPMENT SELECTION AND MATCHING IN
ORDER TO COMPLY WITH SPECIFIC REQUIREMENTS
Gheorghe DOGARU, Felicia DRAGOLICI, Laurentiu DONE
National Institute of Research&Development for Physics and Nuclear Engineering – Horia Hulubei
Decommissioning of VVR-S research reactor from IFIN-HH site as well as of the other nuclear and radiological
facilities which will be decommissioned in the near future implies the necessity of refurbishment and upgrading
of Radioactive Waste Treatment Facilities in order to be able to manage the radioactive waste generated.
In the last decades, the scientific and technical development leads/were focused on to the application of the
radioactive waste management principles based on safety processesand implementation of best practices in order
to increase the public confidence.
The refurbishment and upgrading of Radioactive Waste Treatment Facilities consists of adoption and matching
of new process for management of radioactive waste as super-compaction of solid waste, filtering, ultra filtering
and reverse osmosis for liquid radioactive waste.
In order to improve the safety at handling and encapsulation of spent sealed sources, in particular of neutron
sources,a shielded box was established to be used in the radwaste management processes. In the purchasing
process of shielded box, the specific requirements was issued andcontinuously updated in order to comply with
specific operating conditions.
During the design and construction of the equipment, the entire work was carefully supervised by the operator as
beneficiary. The shielded box was tested in order to check the compliance with parameters imposed by Terms of
Reference.
As conclusion, for acquisition in safe conditions was taken into account the safety requirements for handling,
design and construction as well as the radiological parameters of the spent sealed radioactive sources.
This paper presents the results of the performance tests of the shielded box done with alpha, gamma and neutron
radioactive sources.
202
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SEISMICITY EVOLUTION IN ROMANIA IN RECENT YEARS AND FAULT PLANE
SOLUTIONS RELATED TO MAJOR SEISMIC ZONES
A CRAIU, M. CRAIU, A. MARMUREANU
INCDFP, Bucharest, Romania
The seismic activity of the Romania territory consists on both shallow and intermediate-depth
earthquakes. To define the seismotectonic charachteristics of a seismic region, it is essential to know the seismic
and tectonic activities.
The seismicity of Romania is distributed in several epicentral zones: Vrancea, Fagaras-Campulung, Banat,
Crisana, Maramures and Dobrogea. The seismic activity in Romania is mainly distributed at the contact between
the principal tectonic units: the East-European Plate, the Moesian Plate and Intra-Alpine Plate. This activity is
monitorized by the National Seismic Network operated by NIEP.
The main goal of this presentation is to study seismicity evolution and the focal mechanism analysis of
recent earthquakes occurred in Romania (in last five years) and their correlation with the average stress field.
To this aim we use a data set recorded during 1 Jan 2010-31 May 2014. Location of seismic events
was made with the program developed by Oncescu HYPOPLUS (1996).
From this data set for analysis foult plane solution we used only earthquakes with magnitude M≥4
(h≥60km), M≥3 (h≤60km) and recorded at minimum ten stations. For analysis we applied the SEISAN 8.1
algorithm (Jens Havskov and Lars Ottemoller, 2005) and for focal mechanism we used polarities of P waves.
We have determined fault plane solutions and analyzed seismic activity on the Romania territory in
connection with seismogenic zones. At the same time, our results are integrated and interpreted in connection
with the stress field characteristics, deduced from the available fault plane solutions on different depth intervals.
Over the years the National Seismic Network has developed and now covers even the “aseismic” areas
which now are chracterized by microseismicity (M>2), which a few years ago was impossible to realize. The
growth of seismic stations in the last years on Romania’s territory provides a complete data base, due to the
number of detections and data quality, which leds in the same time to a better location accuracy.
S5 P21
PHYSICO - CHEMICAL CHARACTERIZATION OF SEVERAL SEWAGE SLUDGES
Tanta SETNESCU1, Anca GHEBOIANU2, Radu SETNESCU1,3, Iulian BĂNCUŢĂ2, Roxana BĂNCUŢĂ4,
Marius BUMBAC1, Otilia CULICOV3, 5, Marina FRONTASYEVA5
1
Valahia University of Targoviste, Faculty of Sciences and Arts, Department of Sciences and Advanced
Technologies, Bd. Unirii 18 - 24, Targoviste, 130024,Romania
2
Valahia University of Targovişte - Multidisciplinary Research Institute for Science and Technologies, Bd. Unirii
18-22.,130082, Târgovişte, Romania
3
National Institute for R&D in Electrical Engineering, Department of Advanced Materials. Splaiul Unirii 313,
Sector 3 Bucharest, 030138, Romania
4
The Water Company from Targoviste, 50 I.C. Bratianu Bld.,130055 Targoviste, Romania
5
Joint Institute for Nuclear Research (JINR) Dubna, 141980 Dubna, Moscow region, Russia
Several muds collected from different wastewater treatment stations in Dambovita county were characterized by
different physico-chemical methods (Differential Scanning Calorimetry, ATR-FTIR, EDXRF, AAS). Paralel
DSC measurements in either air or nitrogen, in the range 25 - 550 °C, enabled the characterization of organic
phase oxidability. Finally, the organic content was gravimetrically determined. The organic/ inorganic ratios and
the concentrations of heavy metals (i.e. Fe, Mn, Cr, Cu, Cd, Zn, Pb) were related to different stations as well as
to different sewage steps. The results are discussed in terms of the aplicability of these materials for agricultural
and environmental purposes.
203
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CROSS CORRELATION OF VLF/LF RADIO PROPAGATION PATHS AND THE EUROPEAN
SEISMICITY
Iren-Adelina MOLDOVAN(1), Dragos TOMA-DANILA(1), Angela Petruta CONSTANTIN(1), Mihaela POPA(1),
Victorin Emilian TOADER (1), Anica Otilia PLACINTA (1), Adrian Septimiu MOLDOVAN (2)
(1)
National Institute for Earth Physics, Magurele, Romania ([email protected])
(2)
Azel Desingning Group, Magurele, Ilfov, Romania ([email protected])
International Network for Frontier Research on Earthquake Precursors (INFREP), a network of VLF (20-60
kHz) and LF (150-300 kHz) radio receivers was put into operation in 2009, having as principal goal, the study of
disturbances produced by the earthquakes on the propagation properties of these signals. VLF / LF receivers are
deployed in different locations in Europe. Each one is monitoring up to ten different transmissions of radio
stations across the continent. Information on electromagnetic fields' intensities created by transmitters at each
receiving site and gathered from this network is indicating the quality of the propagation along the paths between
the receivers and transmitters. The Romanian NIEP VLF / LF monitoring system is a part of the international
initiative INFREP, consisting in a radio receiver -made by Elettronika S.R.L. (Italy) and provided by the Bari
University- and the infrastructure that is necessary to record and transmit the collected data. The NIEP VLF / LF
receiver installed in Romania was put into operation in March 2009 in Bucharest and relocated to the Black-Sea
shore (Dobrudja Seismologic Observatory) in December 2009. The receiver can monitor 10 frequencies
distributed in VLF and LF bands and, for each of them, saves the signal's level at a selectable time interval and
has two standard XLR antenna connectors, one for each band, with four poles.
The study will present the status of the VLF/LF electromagnetic monitoring INFREP network having as main
goal the cross correlation of existing radio paths and the most active seismic sources of Europe. The study will
improve the monitoring capabilities of the network and will give us a general view about the existing degree of
coverage.
204
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SEISMICITY OF THE EASTERN PART OF THE MOESIAN PLATFORM
MIHAIL DIACONESCU, ANGELA PETRUTA CONSTANTIN, IREN-ADELINA MOLDOVAN, DRAGOS
TOMA-DANILA
National Institute for Earth Physics, Magurele, Romania ([email protected])
The eastern part of the Moesian Platform is among the areas with moderate seismicity. A study of Cornea and
Polonic (1979) shows a sequence of crustal earthquakes recorded between 1897 and 1977, with magnitudes ≤ 5:
on 04/01/1960 at Căzăneşti (Ialomita River between Urziceni and Slobozia), Ms = 4.5 and epicentral intensity
VI, focal depth 40 km, or earthquake from Radulesti (15 km north Urziceni) from 27/02/1967 with a magnitude
Ms = 5.0 and an epicentral intensity of V degrees
Earthquakes with magnitude ≤ 4.5 were also recorded in the period
analyzed by the authors, with the epicentral areas in the following
localities: Tomşani (east of Ploiesti), Plopeni and Urlati (north and
north east of Ploiesti), Ploiesti then between Bucharest and Ploiesti in
Peris, Tg.Fierbinţi, Caciulati, Otopeni and Vereşti in Bucharest area and
south of Bucharest to Frumuşani Vereşti.
According to Săndulescu (1984) Intramoesian fault crosses the Moesian
platform in the SE-NW separating the two sectors with different
constitution and petrography. Enescu (1992) shows this fault as a well
defined deep fault which cross all lithosphere and extends from the
Black Sea continental shelf northwest up under Getic nappe. Associated
seismic activity is diffuse and low, with only two events exceeding
magnitude 5 and therefore we do not recognize as a active fault. In this
area is remarkable alignment of the north-west of Bucharest NE-SW
oriented to crustal depths of reverse and strike slip faulting type which
leads to the idea that there is a fault with NE-SW reverse fault
Fig. 1 - Seismicity of Dobrudja zone
character, which southeast compartment down south and to the ends
(Romplus 900-2014, Mw> 2)
of the faults are found two faults of strike slip type. The area should
remain under close attention because of the proximity of Bucharest. In
Dobrudja we highlight Horia-Pantelimonul de Sus alignment and Mangalia alignment as alignments of high
seismic sensitivity. Anyway, these two are known as fault and we can say that active faults with a large number
of earthquakes but “unfortunately” the reduced magnitude leading to inability splitting nature of these faults.
205
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MACROSEISMIC STUDY OF MAJOR TRANSBORDER HISTORICAL EARTHQUAKE
Angela Petruta CONSTANTIN, Mihail DIACONESCU, Iren-Adelina MOLDOVAN
National Institute for Earth Physics, Magurele, Romania
On 14 October 1892, at 6.50 a.m. (GMT) (Romplus catalogue), an earthquake caused serious damage in some
places in Bulgaria-Romania transborder area, among the densely populated places of both countries and just
some 100 km away from Bucharest, 145 km from Constanta respectively. The earthquake was felt within the
territory of several countries: Bulgaria, Romania, Rep. of Moldova, Ukraine, Turkey, Serbia (Glavcheva and
Radu, 1994). According to Romplus catalogue this seismic event had M W = 6.5, h = 10 km, I0=VIII MSK
(Oncescu et al., 2000).
Although the studies on this earthquake have been previously done (e.g. Glavcheva and Radu, 1994), a detailed
investigation of documentary sources was performed, in archives storing the documents of old book funds. In
archives we found published reports and most important the original records regarding the effects of the
earthquake. The collected records allowed us to increase the number of macroseismic information, including
new observations in the damaged area from the Romanian territory. The results have been then interpreted in
terms of Medvedev-Sponheuer-Karnik macroseismic scale.
This event is located not far from important cities from both Romanian and Bulgarian territory and to site where
nuclear power plants were to be built in the 1980s (Cernavoda NPP) or could be built in future.
In this study we present macroseismic information about this major transborder crustal earthquake, information
that was obtained as a result of the search in various types of historical sources. Thus, in order to deepen the
studies over the major earthquake that occurred on October 14, 1892 there has been analyzed a great number of
records made by the contemporaries at that time, some of these being discovered as a result of the research made
through more archives and old book funds (Constantin et al., 2009). It can be said that the investigations were
directed especially in finding new primary and original information existing in some of the historical sources
mentioned above, information that are scientifically the most important without being affected by some
interpretations, usually subjective of those who collected and compiled. In this study will be used, as much as
possible, the information coming from the primary sources.
References:
1. Constantin A. P., Pantea A., Stoica R., Amarandei C., Stefan S., (2009) - New Data about Historical
Earthquakes Occurred on the Romanian Territory, Romanian Journal of Physics, ISSN: 1221-146X, Volumul 54,
Nr. 1-2, P. 239–248, 2009, Editura Academiei Romane.
2. Glavcheva, R., Radu, C. (1994) - The Earthquake of October 14th, 1892 in Central Balkans: a transfrontier
case. Historical investigation of European Earthquakes. Materials of the CEC Project “Review of Historical
Seismicity in Europe” – vol. 2., p. 215-223.
3. Medvedev, S. V., Sponheuer, W. and Karnik, V. (1967): Seismic intensity scale version MSK 1964. Publ.
Inst. Geodynamik, 48, Jena.
4. Oncescu, M. C., Marza, V. I., Rizescu, M., Popa, M. (2000) The Romanian earthquake catalogue between
984-1997. Vrancea Earthquakes: Tectonics, Hazard and Risk Mitigation, F. Wenzel, D. Lungu (eds) & O.
Novak (coed.), pp. 43-47, Kluwer Academic Publishers, Dordrecht, Netherlands.
206
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DESIGN AND ANALYSIS OF A RAYLEIGH SAW RESONATOR FOR GAS DETECTING
APPLICATIONS
Viorel IONESCUa
a
Department of Physics and Electronics, Ovidius University, Constanta, 900527, Romania
Polymer coated gas-phase sensors using the classical Rayleigh-type surface acoustic wave (RSAW) mode
showed higher sensitivity and larger dynamic range compared to bulk acoustic wave (BAW) sensors, being
widely used in a variety of sensor systems for chemical and biological gas detection. Finite element approach has
proven to be a viable option to model wave propagation in SAW devices operating in MHz-GHz range.
Using Comsol Multiphysics software, we investigated a 2D finite element model of a SAW gas sensor, which
consists of an Inter Digitated Transducer (IDT) etched onto a piezoelectric LiNbO 3 (Lithium Niobate) substrate
and covered with a thin Poly Isobutylene (PIB) film. We selected for this study a sensor with two IDT structure
types: bidirectional and single phase unidirectional transducer and we computed the deformed shape plot of the
resonance and anti-resonance SAW mode. The variation of electrical potential and total displacement as a
function of structure depth (y coordinate) was also obtained. The sensitivity of the sensor was evaluated by
exposing the sensor to various CH2Cl2 (Dichrolomethane) concentrations.
Keywords: Rayleigh wave, eigenfrequency, DCM gas.
S5 P26
THERMAL INFRARED SATELLITE REMOTE SENSING FOR BUCHAREST ENVIRONMENTAL
STUDIES
National Institute of R&D for Optoelectronics, MG5 Magurele-Bucharest, 077125 Romania.
In frame of global warming, the field of urbanization and urban thermal environment are important issues among
scientists all over the world. Due to rapid influx of urban population, increasing energy consumption and
resultant changes in land use/cover, urbanization and industrialization have led to an overall reduced green
spaces and environmental degradation in the urban/periurban areas. Adverse thermal environment and air
pollution at local and regional levels in Bucharest metropolitan region represent one of the major environmental
issues, among which the urban heat island (UHI) effect is the most important.
Thermal infrared (TIR) remote sensing methods were applied in environmental studies for Bucharest
metropolitan region mainly for analyzing land surface temperature (LST) patterns and its relationship with land
cover surface characteristics, assessing urban heat island (UHI), and relating LSTs with surface energy fluxes to
characterize landscape properties, patterns, and processes.
This paper investigated the influences of urbanization on urban thermal environment as well as the relationships
of thermal characteristics to other biophysical variables in Bucharest metropolitan area of Romania based on
satellite remote sensing imagery Landsat TM/ETM+, time series MODIS Terra/Aqua data and IKONOS
acquired during 1990- 2013 period.
Have been analyzed LST patterns and their relationships with urban/periurban surface biophysical parameters,
especially with vegetation indices NDVI and land use/cover types. Also, have been derived UHI parameters and
surface energy fluxes from time series MODIS Terra/Aqua and NOAA AVHRR satellite data. Derived remotely
sensed variables have been used in synergy with situ meteorological data for urban surface energy modeling.
Results have shown that the ratio of impervious surface in Bucharest increased significantly during more than
two decades investigated period, the intensity of urban heat island and heat wave events being most significant.
The correlation analyses revealed that, at the pixel-scale, LSTs possessed a strong positive correlation with
percent impervious surfaces and negative correlation with vegetation abundances at the regional scale,
respectively. This analysis provided an integrated research scheme and the findings can be very useful for urban
ecosystem modeling.
Keywords: satellite remote sensing, thermal infrared, Urban Heat Island, Bucharest, Romania.
207
S5 P27
EARTHQUAKE PRESIGNALS ASSESSMENT IN VRANCEA GEOTECTONIC ACTIVE ZONE
THROUGH SATELLITE AND IN-SITU MONITORING DATA
1
Medium- to short-term earthquake prediction is becoming ever more essential for safeguarding man, but till now
there have been no verifiable methods of reliable earthquake prediction developed. As one of the most
seismically active area in Europe, Vrancea region in Romania presents a relatively high potential of seismic risk
mainly due to the subcrustal earthquakes located at the sharp bend of the Southeast Carpathians. Earthquake
prediction has two potentially compatible but distinctly different objectives: (a) phenomena that provide
information about the future earthquake hazard useful to those who live in earthquake-prone regions and (b)
phenomena causally related to the physical processes governing failure on a fault that will improve our
understanding of those processes. Cumulative stress energy in seismic active regions under operating tectonic
force manifests various earthquakes’ precursors. This energy transformation may result in enhanced transient
thermal infrared (TIR) emission, as well as of local magnetic field variations, electromagnetic emissions over a
wide range of frequencies, a variety of atmospheric and ionospheric phenomena. For seismic hazard analysis in
Vrancea area, Romania have been selected the earthquake precursors detectable from space which can also be
observed by ground-based monitoring experiments: surface deformation provided by GPS and SAR imaging,
land surface temperature anomalies as possible precursors provided by time-series satellite which can be
detected through satellites equipped with thermal sensors like MODIS (Terra/Aqua) and AVHRR (NOAA),
Landsat TM and ETM, electromagnetic and ionospheric anomalies, radon gas emissions in the faults areas prior
to earthquakes, as well as seismicity. The joint analysis of geodetic, seismological and geological information on
the spatial distribution of crustal deformations is revealing new insights in the understanding of the kinematics
and dynamics of the complex plate boundary system present in the Eastern Carpathians. Fusion of satellite
(LANDSAT TM, ETM, SAR-ERS, ASTER), GPS and field data on Vrancea area including radon (Rn 222)
concentrations variation provides a better monitoring of different geophysical parameters and long-term
deformation in relation with earthquake activity. Multispectral and multitemporal satellite time-series data over
2000-2013 period have been analyzed for recognizing the continuity and regional relationships of active faults as
well as for geologic and seismic hazard mapping. GPS Romanian network stations data revealed a displacement
of about 5 - 6 millimeters/year in horizontal direction relative motion, and a few millimeters/year in vertical
direction. As Vrancea area has a significant regional tectonic activity in Romania and Europe, the survey and
joint analysis of geospatial and in-situ geophysical information of land surface and outgoing long-wave radiation
reveal new insights in the field of seismic hazard assessment.
208
S5 P28
SPECTRAL MIXTURE ANALYSIS POTENTIAL OF SATELLITE IMAGERY
ANALYSIS FOR BUCHAREST URBAN ENVIRONMENT ASSESSMENT
Maria ZORAN, Roxana SAVASTRU, Dan SAVASTRU, Marina TAUTAN, Sorin MICLOS, Laurentiu
BASCHIR
1
Due to anthropogenic and climate stressors, urban landscapes change over time as new urban fabric is added and
also as the existing fabric is internally modified (e.g. new buildings replace old ones, plots are amalgamated or
subdivided, street layouts are modified). These patterns of urban densification and internal modifications are of
major concern to sustainable development because they represent the physical manifestation of a range of social,
economic, cultural, and political dimensions associated with urban dynamics.
Satellite remote sensing has considerable potential for providing accurate, up-to-date information of urban
environments. Mapping land cover, biophysical and thermal parameters in urban environment can be done
through multispectral and multitemporal satellite remote sensing data. Spectral mixture analysis (SMA), based
on a physical mixture model, has ability to extract sub-pixel information such as the abundances of each
endmember presented in the pixel (image unity). In order to examine the performance of each model in dealing
with very high spectral and spatial variability of urban surface, in this paper have been applied different spectral
mixture methods. To extract the abundances of urban surface components, the comparison was focused on linear
spectral mixture analysis (LSMA) which was based on a fixed number of endmembers for the entire scene, and
multiple endmember spectral mixture analysis (MESMA) which allowed the number and types of endmembers
to vary from pixel to pixel.
These techniques have been applied to map the physical components of urban land cover for the urban area of
Bucharest metropolitan area, Romania, using Landsat TM/ETM+ imagery for 1989 – 2013 together with
IKONOS satellite data. Field spectra of vegetation, soil, and impervious surface areas collected with the use of a
fine resolution and IKONOS image and pixel purity index tool in ENVI 4.7 software were modeled as reference
endmembers in addition to photometric shade that was incorporated in every model. This study employs 28
endmembers and 650 spectral models to identify soil, impervious, vegetation, and shade in the metropolitan area
of Bucharest. The mean RMS error for the selected land use land cover classes range from 0.0049 to 0.018. The
Pearson correlation between the fraction outputs from MESMA and reference data from IKONOS 1m
panchromatic resolution data for soil, impervious, and vegetation were 0.763, 0.7312, and 0.8316 respectively.
This paper demonstrates the potential of moderate-and high resolution, multispectral imagery to map and
monitor the evolution of the physical urban environment, MESMA approach being reliable as the subpixel
processor picked out the spectral signatures effectively. These techniques adequately characterize the diversity of
materials that compose land cover within a diverse urban area like Bucharest, and at the same time provide a
conceptual structure for grouping the specific materials into three general classes—vegetation, impervious, and
soil. These generalized classes can characterize urban land cover regardless of specific construction materials or
local environmental variation, facilitating comparison of urban data sets on a global scale.
Keywords:
Romania.
satellite remote sensing, Spectral Mixture Analysis, urban/periurban land cover, Bucharest,
209
S5 P29
PHYSICAL CHARACTERIZATION OF BIOLOGICAL CELLS USING AN ASSISTED
MICROMECHANIC SYSTEM
Mihaita Nicolae ARDELEANU1, Marius Giorgian IONITA2,
Valentin GURGU3, Ioan Alin BUCURICA4, Ioana Daniela DULAMA4, Emil LUNGU5
1
Valahia University of Targoviste, Faculty of Materials Engineering and Mechanics, 130024 Targoviste,
Romania. E-mail: [email protected]
2
Valahia University of Targoviste, Faculty of Electrical Engineering, Electronics and Information Technology,
130024 Targoviste, Romania. E-mail: [email protected]
3
Valahia University of Targoviste, Doctoral School, 130024 Targoviste, Romania.E-mail:
[email protected]
4
Valahia University of Targoviste, Multidisciplinary Research Institute for Science and Technologies, 130024
Targoviste, Romania. E-mail: [email protected]; [email protected]
5
Valahia University of Targoviste, Faculty of Sciences and Arts, 130024 Targoviste, Romania.E-mail:
[email protected]
Physical properties characterization of the soft microscopic objects presumes very precisely measurements of the
object deformations and involved deformation forces. Video-detection can offer the correct solutions for both
problems.
The present work study proposes the accomplishment (development) of an experimental model through which it
can be simultaneously measure the deformation and the elasticity of polyurethane spheres. These emulate the
physical model of biological cells.
The experimental model is based on a microfiber with double role: force generator and sensor. Another essential
component of the proposed system is represented by the video detection elements used to obtain data regarding
the spheres and microfiber deformations.
After experimental data processing, it will be acquired information about membrane elasticity of the analyzed
cells.
Acknowledgement: The authors would like to thank the Project ADMAN “Advanced devices for micro and
nanoscale manipulation and characterization”, code: PN-II-RU-TE-2011-3-0299 of Valahia University of
Targoviste.
210
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HEAVY METALS DISTRIBUTION IN URBAN SOILS COLLECTED FROM TARGOVISTE CITY
Ioana Daniela DULAMA1, Claudia STIHI2, Cristiana RADULESCU2, Ion V. POPESCU1,2,3,4, Ioan Alin
BUCURICA1, Raluca STIRBESCU5, Lucica Grigora TOMA1, Daniela Elena CHELARESCU4,5
1
Valahia University of Targoviste, Multidisciplinary Research Institute for Science and Technologies, 130024
Targoviste, Romania.
2
Valahia University of Targoviste, Faculty of Sciences and Arts, 130024 Targoviste, Romania.
3
Academy of Romanian Scientists, 050094 Bucharest, Romania.
4
Horia Hulubei National Institute of Physics and Nuclear Engineering, 077125 Magurele, Romania.
5
University of Bucharest, Faculty of Physics, Doctoral School, 050107 Bucharest, Romania.
[email protected]
Urban soil pollution can be influenced by both the natural and anthropogenic factors. In this study, the
concentration of 7 heavy metals including Fe, Co, Cu, Zn, As, Cd and Pb in urban soils was assessed in
Targoviste City, Romania.
For this analysis, soil samples were collected from 40 different locations (cross-roads) from Targoviste and
adjacent areas. For more investigations, the samples were collected in both 2012 and 2013. The results revealed
that the mean concentrations were in the order Fe ≫ Zn ≫ Cu ≫ As > Co > Pb > Cd, in both years. The first
conclusion of this study is the decrease of concentration values for all metals in 2013 than 2012 as a
supplementary proof of the decrease of activity from industrial platform. But the industrial platform isn’t the
only pollution source, the buildings construction sites, vehicle emissions, storages with building materials,
industrial activity from Doicesti, all of these represent important pollution sources.
In this study were draw the spatial distribution maps and all the obtained data have been compared with normal
values (NV), maximum (ML) and intervention level (IL) appointed by the Romanian legislation – Order
756/1997, and also with the mean European value (ME).
211
S5 P31
NEW MIXED LIGAND CO(II) COMPLEXES AS POSSIBLE ELECTROLYTES FOR DYESENSITEZED SOLAR CELLS – A COMBINED EXPERIMENTAL AND COMPUTATIONAL
APPROACH
Marilena FERBINTEANU,a Daniela STAMATE,b Corneliu I. OPREA,b Petre PANAIT,b Mihai A. GÎRŢU a
a
Department of Inorganic Chemistry, University of Bucharest, Bucharest 020462, Romania
b
Department of Physics, Ovidius University of Constanţa, Constanţa 900527
Dye-sensitized solar cells (DSSCs) with cobalt complex redox electrolytes have achieved high photoconversion
efficiencies of over 12% and high open-circuit voltages (Voc) because of the higher redox potential in cobalt
complex redox systems as compared to that of conventional I 3-/I- redox systems.1 We report the synthesis and
characterization of a new series of mixed ligand Co(II) complexes, [Co(AA)(BB) 2]X2, where AA and BB
are
derivatives of
1,10-phenanthroline and 2,2’-bipyridil,
X=Cl-,
TFSI(TFSI=
bis(trifluoromethanesulfonyl)imide), as possible redox electrolytes for dye-sensitized solar cells (DSSC).
In particular, our goal is to increase the open circuit voltage and the overall photovoltaic conversion
efficiency of the device by fine tuning the redox potentials of Co(II) complexes. The synthetic strategy of such
heteroleptic compounds is a challenge due to the tendency of the Co(II) ion to form tris chelates compounds or to
disproportionate and includes in the first step the synthesis of [Co(AA)Cl 2] and [Co(BB)2Cl2] complexes and
then the addition of the second aromatic diamine and TFSI anion. The compounds were characterized by
spectral (IR and UV-VIS spectroscopy) and theoretical modeling via Density Functional Theory calculations.
(nm)
=427 nm
=442 nm
=459 nm
Absorption (arbitrary units)
Absorption (arbitrary units)
[1] A. Yella, H. Lee, H.N. Tsao, C. Yi, A.K.
Chandiran, M.K. Nazeeruddin, E.W. Diau, C.
(1)
Yeh, S.M. Zakeeruddin, M. Gratzel, Science
(2)
2011, 334, 629.
(3)
(4)
*Acknowledgement: The financial support
received from SNSF and UEFISCDI under the
Romanian-Swiss Research Programme, through
the grant RSRP #IZERO-142144/1—PN-II-IDRSRP-1/2012 is gratefully acknowledged.
**Email:
[email protected],
200
400
600
800 1000 1200
[email protected]
400
600
(nm)
800
212
S5 P32
THE INTERACTION OF TiO2 NANOPARTICLES WITH FUNCTIONAL GROUPS OF SOME
AROMATIC AZO DYES IN DYE-SENSITIZED SOLAR CELLS AND IN PHOTOCATALYTIC
PROCESSES
Petre PANAIT,1 Corneliu I. OPREA,1 Jeanina, LUNGU,1 Daniela STAMATE,1
Anca DUMBRAVA,2 Mihai A. GÎRŢU1*,**
1
2
Department of Physics and Electronics, Ovidius University of Constanţa, Romania
Department of Chemistry and Chemical Engineering, Ovidius University of Constanţa, Romania
Azo dyes, the largest class of synthetic dyes, may be used as TiO2 sensitizers in dye-sensitized solar cells
(DSSCs).
We report here results of theoretical studies of Mordant Yellow 10 (MY 10), 5-(4sulfophenylazo)salicylic acid disodium salt, focusing on the adsorption of the dye, in various pH dependent
forms (protonated and deprotonated) onto TiO2 nanoclusters, taking advantage of the presence of carboxyl,
hydroxyl and sulfonic groups as possible anchors. Using DFT calculations to study the charge transfer from the
dye to the semiconductor, we demonstrated that using MY 10 the DSSC performance as a function of the
anchoring group decreases in the order hydroxyl + carboxyl > carboxyl > sulfonic group [1].
A similar approach can be applied to the photocatalytic degradation with TiO 2 as catalyst of azo dyes in
wastewaters, having in view not only the breaking of the azo bond, but also the degradation of the aromatic
rings. Compounds like phenol, benzoic acid, p-hydroxy-benzoic acid and salicylic acid may result due to the
breakup of the azo bond and their removal from wastewaters is an important environmental issue. We analyzed
the absorption spectrum of the free and adsorbed molecules, the binding configurations, the matching of the
energy levels with the TiO2 catalyst and the likelihood of the charge-transfer to the substrate. We demonstrated,
using DFT calculation, that the
efficiency of degradation under visible
light irradiation decreases in the
sequence salicylic acid > phenol > phydroxy-benzoic acid > benzoic acid,
results which are in good agreement
with the experiments.
[1] C.I. Oprea, P. Panait, J. Lungu, D.
Stamate, A. Dumbravă, F. Cimpoesu,
M.A. Gîrţu, Int. J. Photoen. 2013,
893850.
*Acknowledgements: The financial
support received from SNSF and
UEFISCDI under the Romanian-Swiss
Research Programme, through the
grant RSRP #IZERO-142144/1—PNII-ID-RSRP-1/2012
is
gratefully
acknowledged.
**E-mail:
mihai.
[email protected]
213
S5 P33
ADSORPTION OF COUMARIN-BASED DYES ON TiO2 NANOCLUSTERS – EFFECT ON THE
SHORT-CIRCUIT CURRENT OF DYE-SENSITIZED SOLAR CELLS
Petre PANAIT,1Corneliu I. OPREA,1 and Mihai A. GÎRŢU1,*,**
1
Department of Physics, Ovidius University of Constanţa, Constanţa900527, Romania
Coumarin-based dyes have been successfully used in dye-sensitized solar cells, leading to photovoltaic
conversion efficiencies of up to about 8%. Given the need to better understand the behavior of the dye adsorbed
on the TiO2 nanoparticle, we report results of density functional theory(DFT) and time-dependent DFT(TDDFT) studies of threecoumarin-based dyes,C343, NKX-2398 and NKX-2311, as well as complex systems
consisting of the dye bound to a TiO2 cluster. We provide the electronic structure and simulated UV-Vis spectra
of the dyes alone and adsorbed to the cluster and discuss the matching with the solar spectrum. We display the
energy level diagrams and the electron density of the key
molecular orbitals and analyze the electron transfer from the
dye to the oxide. Finally, we compare our theoretical results
with the experimental data available and discuss the key
issues that influence the device performance.[1]
[1] C.I. Oprea, P.Panait, F.Cimpoesu, M.Ferbinteanu,M.A.
Gîrţu, Materials2013, 6, 2372-2392.
*Acknowledgements:The financial support received from
SNSF and UEFISCDI under the Romanian-Swiss Research
Programme, through the grant RSRP#IZERO-142144/1—
PN-II-ID-RSRP-1/2012 is gratefully acknowledged.
**E-mail:
[email protected],
[email protected]
S5 P34
CRUSTAL SEISMICITY ANALYSIS IN ROMANIA USING ANTELOPE AND SEISCOMP 3
M. CRAIU, A. MARMUREANU, A. CRAIU
INCDFP, Bucharest, Romania
The main goal of this study was the comparison of the informations provided by the seismic bulletins obtained
after location of a seismic event with two different acquisition systems (Antelope and SeisComp3), in order to
improve their detection capabilities, location accuracy, magnitude and depth determination and reduce the RMS
and other location errors.
The Seedlink and AntelopeTM program packages are used for this real-time data acquisition and
exchange. The Antelope real-time system provides automatic event detection, arrival picking, event location, and
magnitude calculation. In order to refine the automatic solutions, Antelope is further used for manual processing
(e.g. association events, magnitude computation, database, sending seismic bulletins, calculation of peak ground
acceleration and velocity), for generating ShakeMap products and interacting with international data centers.
In parallel, SeisComP3 is running at NIEP Bucharest as a complementary data acquisition and back-up
automated system, data quality control, real-time data exchange and processing, network status monitoring.
In this study we included the crustal eartquakes (H<60 Km) recorded in the main seismic zones of Romania
(Vrancea, Fagaras-Campulung, Banat, Transilvania and Dobrogea) during January – March 2014.
Seismological observatories are increasingly required to provide very rapid information. To meet this goal
automatic location tools and rapid interpretation tools like automatic locations, magnitudes and ShakeMaps are
currently being implemented within the observatories. Modular software packages for Antelope and SeisComp3
are often developed in research environments and these provide observatories with new or improved tools
facilitating routine observatory practices.
172
Section 6 – TOPICS IN PHYSICS EDUCATION RESEARCH
SECTION
S6 – Topics in Physics Education Research
Physics curriculum design
Active learning techniques
Classroom teaching, demonstrations and laboratory experiments
173
INVITED LECTURES
S6 L01
THE BENCHMARKS OF A SUCCESSFUL REFORM PROPOSAL IN EDUCATION
C.HATU
Romanian Physical Society, 409 Atomiștilor Street, Măgurele, Ilfov
Besides preparing a scientifically correctchangeing proposal of the teaching methodsin Physics, there are other
key elements that matter in successful completion of such a proposal. We began a project which aimed to change
the teaching methods in Physicsthree years ago. During the presentation, I intend to answer the following
questions: what are the elements to take into account when we design and develop a project which aims to make
a change in the education system? How do we proceed to increase the chances of success of such reform
proposals?
Acknowledgments:“Reforming the Teaching of Physics in Secondary Education” is a project coordinated by
Romanian Physical Society and supported by the Romanian-American Foundation.
S6 L02
KNOWLEDGE’S ASSESSMENT BY ITEM RESPONSE MODELS
Cristian OPARIUC-DAN
Ovidius University of Constanţa, Romania
Knowledge’s assessment by specific tests, usually, represents a process marked by subjectivism despite the
appearance of objectivity that provides exact sciences. In the vast majority of cases, this assessment process
results in a ranking of students based on an ordinal measurement level, this being the case of so called normative
assessment. More rarely, based on assessment results, the future performances can be predicted using some data
analysis specific techniques, the process called criterion based assessment. Regardless the type of assessment, we
cannot find the quantity of the knowledge, because they cannot be measured directly, naming this concept as a
latent content.
This paper intends to present the specifics of such measurements and the reasons underlying the subjectivity of
this kind of assessments, suggesting an alternative assessment model through which we can reach a scalar level
of measurement, even we do not achieve a ratio level. It’s about the exposure of the principles of the item
response theory and their relations with the continuum latent factor term, with applications in physics knowledge
assessment.
Key-words: assessment, item response models, latent trait, items bank.
S6 L03
CHALLENGES IN PHYSICS TEACHING AND ASSESSMENT
Roxana ZUS
University of Bucharest, Faculty of Physics, P.O. Box MG-11, RO – 077125 Bucharest-Magurele, Romania
Science education has not increased its efficiency for many years, as shown in the TIMSS (Trends in
International Mathematics and Science Study) rankings for Romania, starting 1995 [1]. Only the best performing
students (between 2% and 4% of the total Romanian school population) meet the requirements of the science
curriculum [2,3]. One needs to adapt the teaching approach to the real life experience of pupils and to employ
teaching strategies that attract and motivate them.
Several national recent projects, as [3] and [4], have focused on solutions to physics/ science teaching and
learning. Apart methodological guides for physics teachers employing techniques centred on pupils in order to
encourage active learning and critical thinking, the projects included programs of training and support for
teachers.
174
Similar challenges are faced at international level and one should also focus on ongoing and future training and
educational programs at European level.
Keywords: physics teaching, physics assessment, active learning, critical thinking.
References:
[1] Martin, M.O., Mullis, I.V.S., Foy, P., & Stanco, G.M. (2012). Chestnut Hill, MA: TIMSS & PIRLS
International Study Center, Boston College.
[2] Noveanu, G.N., “Curriculum intenţionat – curriculum realizat. Studiu comparativ la disciplina chimie”,
Bucureşti: Sigma (2009).
[3] “Un învăţământ performant bazat pe decizii fundamentate - Strategii de valorificare a evaluărilor
internaţionale privind rezultatele învăţării”, POSDRU/55/1.1/S/35279.
[4] “The reform of teaching Physics in pre-university education” - project coordinated by Romanian Physical
Society in partnership with Center Education 2000+ and supported by the Romanian-American Foundation.
ORAL PRESENTATION
S6 OP01
THE KEY EXPERIMENT USING „AT HAND” RESOURCES – AN EFFICIENT METHOD IN
PHYSICS TEACHING
Ion BĂRARU
Colegiul Național ”Mircea cel Bătrân”, Constanța, România
In the recent years, teaching physics became a quite difficult process, because both of the lack of
material resources and the conceptual attitudes. One can notice the lack of interest to use the „integrated in
lesson” experiment. There is a justification: there are not sufficient didactic materials and the students and
parents interest for physics is dramatically low. But we consider that the students’ interest for the technology is
relatively constant, perhaps quite increased. We also strongly believe that it is possible to realize key
experiments using „at hand” resources. This kind of experiment can be the reference element for a certain lesson.
It can be appealed as many times as necessary during the lesson. It can be reproduced easily at home, attracting
more and more students in physics phenomena.
In this article we show some essential aspects in order to elaborate and apply the „at hand” resources
experiments in physics lessons. Even though the experiments seem to be very simple, they request very
important attention and careful preparation. We offer some samples of one minute movie showing key
experiments. They are strictly addressed to the teachers, as a guide in certain lessons. We also propose an
orientated data sheet in order to use the movies in classroom. We posted some of these movies on SRF site
‘rpfip.srfizica.ro:85.’ Recent site statistics show that these movies are quite often accessed by physics teachers
POSTERS
S6 P01
STUDYING PHYSICS BY TECHNOLOGICAL APPLICATIONS
Mihaela GHELMEZ (DUMITRU)1, Ionut-Alexandru MOLDOVEANU2,Manuel RIBEIRO DA SILVA2
1
“Politehnica” University of Bucharest, Physics Department
”Politehnica”University of Bucharest, Mechanical and Mechatronics Faculty
Splaiul Independentei 303, 77206, Bucharest, Romania Tel: +4021 402 9102; E-mail: [email protected]
2
175
At Mechanical and Mechatronics Faculty-U.P.B., Physics is a subject studied in the first year, 1 st
Semester 2 h course of lectures and 1 h seminar/per week, and 2 nd Semester 1h course of lectures and 1h
laboratory/per week.The paper presents thework of teacher and students together for improving the Physics
knowledge by studying in parallel some specific application, interesting for the students of this faculty.
A list of possible applications is first proposed by the teacher, and students are asked to choose one as a home
project; they also could propose their own themes of interest and develop them, as well.Basic literature is studied
and relevant physical phenomena involved are underlined. The work is completed by means of some
experiments, computer simulations, or even creating some new devices and installations.
Students’ work is individual or in teams, formed by them; their leaders appear in a natural way. The
best results are presented at the SSCS (Scientific Session of the Students from P.U.B.). In the paper, we
exemplify with some works that evidence the physical phenomena involved in functioning of some important
motors for the future mechanic engineer, but not only: thermic/frigorific, auto, human. Taking into account the
physic principles involved in each situation, some methods for improving and developing are proposed and
realized by the students. They worked together with the teacher and some companies or specialists. The results
are presented in the paper.
For instance, a work in obtaining information on some physical properties of old and new materials in the
frigorific mashines domain is presented, in connection with the usual diagrams based on the II nd Principle of
Thermodinamics. In the auto motors domain –very interesting especially for young people – the physical
phenomena concerning “tuning” are analysed and some practical results are presented. The performances are
studied by “dyno test”, a diagram realized with special software, measuring the power (CP) and the cuple(Nm),
as in the next figure:
In all cases,protection and ecological aspects are fully underlined.
This form of learning is as a completion of the tutorial.The goal is to evidence the role of Physics in explaining
and creating new items in engineering
S6 P02
OPPORTUNITIES FOR IMPROVEMENT THE TEACHING PROCESS -CULTIVATION STUDENTS´
CREATIVE THINKING
Irina MARIN
Physics Department, Economic College Mangalia, Constanta, Romania
Physics is the „engine” in the progress of all the other sciences, which opened paths, boosted decisive
evolution of other areas and has opened new research directions. Notions, concepts, phenomena, laws of physics
underlying technological progress and improve human life.
Promoting creativity is the key to technological progress. Creativity education is an approach that involves
being open to the experience, sensitivity to new, originality, flexible and divergent thinking, the ability to
combine more ideas.
Stimulating and training students´ creativity can be done through learning focus on the needs, aspirations and
interests of students, interdisciplinary and transdisciplinary.
In this approach of developing the capacity of investigation in detail, adaptability, finding new uses, increase
devices performance, is enroll the project „Raspberry Pi” made by a team of students of 8th grade from
„Callatis” high school of Mangalia.
176
S6 P03
BLENDED LEARNING MODELS IN ROMANIAN SCIENCE EDUCATION
Dana CRACIUN1, Madalin BUNOIU2
1
Teacher Training Departament, West University of Timișoara 4 V. Pârvan, Timișoara, Romania
2
Faculty of Physics, West University of Timișoara 4 V. Pârvan, Timișoara, Romania
Abstract. The penetration of Information and Communication Technology (ICT) in the Romanian education
environment leads to significant changes in the teaching-learning-evaluation process [1]. Teachers can use ICT
in at least three ways: to ensure the necessary materials and distribute course related information through
announcements or emails; to enhance the quality of the students’ learning experiences outside the classroom by
using ICT resources for communication and collaboration, evaluation and course management - blended learning
(BL); or to support self-directed learning through interactive and collaborative learning activities - online courses
[2].BL can be used in primary, secondary and high school science education to design activities that rely on
problem based learning, project based learning or activity based learning.
In tertiary science education BL can be integrated in the structure of theoretic activities (lectures). Moreover, BL
is also a good choice for applied activities where experiments can be combined with simulations or remote lab
assignments[3].
Figure 1. Traditional and BL Teaching and learning experiences
In this study we present various models for the design of mixed/blended learning activities that can be applied in
the Romanian educational system for primary, secondary and also tertiary level physics education using current
ICT resources. We also describe the reasons why blended learning is not used on a wide scale in science classes
especially in primary and secondary education.
Keywords: blended learning, science, BL scenarios
References:
[1] Noveanu E., D. Potolea, S. Velea, P. Botnariuc, C. Novak, O. Istrate, Informatizarea sistemului de
invatamant: Programul S.E.I., EVAL SEI 2008, Bucuresti, Agata (2008).
[2] Oh, E., & Park, S. (2009), How are universities involved in blended instruction?, Educational
Technology&Society, 12 (3).
[3] Shaer M. El, M. Mobasher, H. Arafa, A. Zaki, Blended Learning Approach in Research and Education of
Laboratory Physics, Conference ICL2010, 2010 Hasselt, Belgium.
S6 P04
LEARNING PHYSICS ACTING GAMES
D. RĂSLEANU, A. DANCU, D. PETRE
High School „Lazar Edeleanu”, Navodari, Romania
The electronic Physics Journal "Quasar" represents the final step of every activity within the scientific project
“Physics and Computer”. The journal is realized by the high school students under the guidance of physics
teachers.
In this year, our team, students and teachers, has traveled in time.
177
S6 P05
INTERDISCIPLINARITY IN TEACHING, LEARNING AND EVALUATING SCIENCE OF NATURE
Madalina IVANESCU
Universitatea Bucuresti,Romania
Inspectoratul Scolar Judetean Constanta, Romania
School subjects today comprise plenty of information which does not simplify them, on the contrary, it makes
them more difficult to be understood. Thus, interdisciplinarity represents an essential part in the process of
knowledge. The young generation needs to be prepared to face not only the present, but the future as well. Their
creativity must be stimulated, since they will be required to cope with different situations.
The principle of interdisciplinarity derives from scientific research. As far as education is concerned,
interdisciplinarity is observed through elaborating the contents and lesson planning.
Subject connection is achieved at four levels:

Multidisciplinarity – joining aspects from different subjects, in order to underline their common
elements; it is the most frequent way of overloading the curriculum and it brings about negative effects on
students’ personalities.

Pluridisciplinarity – contents are organized according to a topic, situation, problem discussed by
different subjects; it presents the general aspect of a topic in relation with other real phenomena.

Interdisciplinarity – high level coordination which implies a certain level of integration of different
fields and different approaches, using a common language. According to this, the already existent knowledge is
selected and other is formed.

Transdisciplinarity – high level coordination and cooperation; subjects are seen as situation and learning
experience suppliers.
In education, interdiscplinarity focuses on decreasing the differences between school subjects.
Monodisciplinarity is gradual and rigorous, but it can lead to isolating both the student and the teacher from
reality. Being devoted to his subject, the teacher tends to put aside his main object – the student. The analytical
approach is essential in certain moments of teaching, but there is also a need to trace bridges between different
school subjects, in order to understand the reality better.
Interdisciplinarity between Chemistry, Physics, Mathematics and Biology is achieved through teaching
strategies, both as a form of lesson planning and methods used to understand the knowledge that is checked or
evaluated.
The content is also important, Mathematics being the instrument for observation, experimentation, rules, theory,
each approach being done through mathematical operations.
INDEX
A
A. EVANGHELIDIS, S1 P36 S1 P37
A. LUNGU S1 O01 S1 P18
ADÁMEK J. S2 L02
ADOMNITEI Catalin S1 P47
AGHEORGHIESEI, C S4 P17
AGOP M. S2 L09
AIRINEI Anton S1 P43 S1 P44
ALBE Karsten S1 L09
ALBU Catalina, S2 L010
ALDICA G. V. S1 P46
ALEXANDRU Horia V. S1 L05 S1 O02
ANGHEL D. V. S4 OP1
ANGHEL Dragos-Victor S5 P14
ANTOCI Vasilichia, S4 P12
ANTOHE Ştefan S1 L03 S1 P59 S1 P60
ANTOHE Vlad-Andrei, S1 L10
AOKI K. S0 01
APETREI Marius S5 P13
ARDELEANU Mihaita Nicolae S5 P29
ARGINTARU Dănuţ S3 P06
ARJOCA S. S0 01
ASAVEI Theodor S2 L011
ASTEFANOAEI Corina S4 P06
ASTEFANOAEI, C. S4 P17
AVADANEI Mihaela, S1 P43
AXENTE E. S1 L18 S2 P14
AZUMA S. S5 L02
B
BABAN Valerica S3 P06
BACSEI Raluca S1 O02
BAIA L. S1 P34 S5 L12 S1 P33
BAIA M. S1 P33 S1 P34
BALACEANU Mihai, S2 P17 S2 P18
BALAŽ Antun S4 L01
BALOGH E. S2 P10
BANCIU M. G., S4 P02 S1 P07 S1 P45 S1 P46
BANCUTA Iulian S4 P07 S4 P08 S4 P09 S4 P10
S5 P21 S5 P12 S5 L10
BANCUTA Oana Roxana S4 P09 S4 P10 S4 P08
BANCUTA Roxana S4 P07 S5 P21 S5 P12
BANICI R. S2 L03 S2 OP3
BARACU A. S1 P16
BARAN V. S3 L03 S3 OP2
BĂRARU Ion S6 OP01
BARBU Marian S4 P23
BARIS Avar S1 P14 S1 P15 S1 P21
BARJEGA Ruxandra S2 P08
BARNA V. S1 P09 S2 P16
BARSAN Victor S1 L08
BARYSHNIKOV G. V., S5 L01
BASCHIR Laurentiu S5 P28
BELC M. S1 L14 S3 OP4 S3 P22
BENEA D. S1 P20 S1 P38 S1 P49
BERCU V. S5 L04
BEREZOVSKI Cristina S2 P16
BEREZOVSKI R. S2 P16
BERLIC C. S1 P09
BESLEAGA C. S1 P26
222
BEZERGHEANU A. S1 P49
BILETCHI Lucia S5 P04
BIRSAN Anca S1 P06
BIRSAN Marius-Victor S5 P18
BITA B., S1 P25
BOGDEVICH Oleg S5 P01
BOLUNDUŢ Liviu, S1 P10 S1 P12
BONASERA A. S3 L01
BORDBAR G. H. S3 L02
BORHAN Adrian S1 P19
BOŢA Gabriela S1 P03
BRADU Adrian, S5 OP4
BRAIC Mariana S2 P17 S2 P18 S2 L04
BRAIC Viorel, S2 P17 S2 P18 S2 L04
BRANDUS Catalina, S2 OP4
BREAZU C. S1 P35
BREAZU C.S. S2 P14
BRÎNCOVEANU O. S1 P23
BUCURICA Ioan Alin S5 P29 S5 P30
BULZ Ciprian S1 P11
BUMBAC Marius S5 P21
BUNOIU Madalin S6 P03
BUNOIU Madalin, S1 L11 S1 P57 S5 OP2
BURADA Adrian, S4 P24
BURCEA Sorin S5 P10
BURDUCEA I. S1 P01
BURDUCEA Ion S3 P01 S3 P03
BURLUI V. S1 P54 S1 P55
BURSIK Jiri, S2 L08
BURSIKOVA Vilma, S2 L08
BURZO E. S1 L16
BUSE Gabriel S1 P57
BUSUIOC Aristita S5 P17 S5 P18
BUTE Oana Catalina, S5 L05
BUTOI B. S2 P16
C
CAHA Ondrej, S2 L08
CALIN G. S1 P54 S1 P55
CALINESCU Ioan S2 P03
CALINESCU Ionut-Catalin S3 P04
CALTUN Ovidiu F S1 P19
CANTARAGIU Alina S1 P05
CARBUNARU Daniel S5 P10
CARRETERO-GONZALEZ Ricardo S0 05
CAZACU Maria S1 P44 S1 P43
CECCATO D. S3 P08 S3 P09
CELIKTAS C. S3 P17
CELIKTAS Cuneyt S2 P15
CERNAIANU Mihail S2 L011
CHELARESCU Daniela Elena S5 P30 S5 L10 S5
OP01
CHERKEZ Radion S1 P28
CHICEA Dan S4 OP2 S4 P15 S1 P03
CHICEA Liana Maria S4 P15 S1 P03
CHICEA Radu S1 P03 S4 P15
CHICINAŞ I. S1 P41
CHILIAN A. S5 P12
CHILIAN Andrei S4 P08 S4 P10
CHIRILA C. S1 P07 S1 P26
INDEX
CHITEA Florina S5 P07 S5 P11
CIMPOCA Gheorghe Valerica S4 P09 S4 P10 S5
L05 S4 P07
CIMPOESU Fanica S5 L06 S5 L07 S5 L09
CIOANGHER M., S1 P45
CIOANGHER Marius S1 P39
CIOMAGA C. E. S1 P17
CIORSAC Alecu Aurel S4 P01
CIUPINĂ V. S1 P23 S1 L14 S1 P29 S1 P30 S1
P31 S4 P22 S1 P22
Claudia STIHI S4 P09 S5 P30
COJOCARU B. S5 L11
COJOCARU G. S2 L03 S2 OP3
COJOCARU Gabriel, S2 L010
COLDEA M. S1 P42
COLONNA M. S3 L03
CONDURACHE-BOTA Simona S1 P50 S1 P58
CONSTANTIN Angela Petruta S5 P22 S5 P23 S5
P24
CONSTANTINEANU Raluca S1 P60
CONSTANTINESCU B. S3 P08 S3 P09
CONSTANTINESCU Eliodor S3 P06
COȘOVEANU V. S1 P34 S1 P33
COSTEA Stefan, S2 L01 S2 P19
COTIRLAN C., S1 P24
COTIRLAN-SIMIONIUC Costel, S1 P32 S5 P16
COTOROBAI Florin S1 P40
COVLEA V. S2 P16
CRACIUN Dana S4 P14 S6 P03
CRACIUN Gabriela S2 P03 S2 P05 S2 P06 S2 P04
CRACIUN L. S1 P02 S1 P01
CRACIUN Liviu Stefan, S4 P05 S3 P16
CRACIUNESCU T. S5 P02
CRAIU A, S5 P20 S5 P34
CRAIU M., S5 P34 S5 P20
CREANGA Dorina S4 P06 S4 P18 S4 P16 S4 P17
S1 P02
CRISTEA-STAN Daniela S3 P08 S3 P09
CROITORU A. S3 L03
CULEA Eugen S1 P11 S1 P10 S1 P12 S1 P13
CULICOV Otilia S5 P21 S3 P13 S5 P12
CULIGHIN Elena S5 P01
D
DA SILVA Manuel Ribeiro S6 P01
DABU Razvan S2 L011
DANCIU A., S1 P25 S6 P04
DANCIU V. S1 P33 S5 L12 S1 P34
DANCUS Ioan S2 L011
DARTU L. S1 P54 S1 P55
DASCALU T. S2 OP3
DASCALU Traian S2 L07 S2 OP4 S2 P08
DAUL Claude S5 L06
DAVIDOVA L. S4 P21
DEAC I.GR. S1 P49
DELION D. S. S3 OP1
DEMLER E. A. S1 L17
Di STASI Leandro L. S4 P06
DI TORO M. S3 L03
DIACONESCU Mihail, S5 P23 S5 P24
223
DIACONU Andrei S1 P19
DIMA Gabriel S4 P08
DINCA M. S2 OP3
DINCA P. S2 L03 S5 P02
DINCA Virginia S2 L05 S2 P01 S2 P02 S1 L14
DINESCU Gheorghe S2 OP1
DINESCU M. S1 L13
DINU M. S2 L04
DOBREA C. S5 P02
DOBRINESCU Andreea S5 P17
DOGARU Gheorghe, S5 P19
DONE Laurentiu S5 P19
DORNEANU Petronela, S1 P44
DOROFTEI C. S1 P27 S5 P15
DOROHOI Dana Ortansa S2 P13
DRAGOLICI Felicia, S5 P19 S3 P10
DRĂGUŞIN Mitică S3 P18 S3 P19 S3 P20 S5 P06
DULAMA I. S5 L10
DULAMA Ioana Daniela S5 P29 S5 P30
DULIU O.G. S5 L04
DUMA Virgil-Florin S5 L13 S5 OP4
DUMANOV E.V. S2 P11
DUMBRAVA Anca S1 P53 S1 P56 S5 P32
DUMITRESCU A. S3 OP1
DUMITRESCU Alexandru S5 P18
DUMITRIU Ana Elena, S3 P14
DUMITRU Ioan S1 P19
DURA Nicolae, S1 P13
E
EDA Çinar Avar S1 P21
EFTEKHARI Ali S1 L04
ELIF Loğoğlu S1 P21
ENACHE Daniel S3 OP4
ENACHESCU C. S1 P51
ENAKI Nicolae A., S2 P07
ENCIU Lucia Elena S3 P21
ENCULESCU I. S1 P36 S1 P37
ENCULESCU M., S1 P36 S1 P37
ENCULESCU Monica, S1 P40
ENE Antoaneta S1 P05 S5 P01 S5 P04 S5 P09
ERDINIZ Nazli S3 P12
ERGINER M. S1 L18
ERMIS E. E. S3 P17
EROGLU M. S. S1 L18
F
FAHLMAN Mats S0 02
FENIC Constantin, S0 06
FERARU I. S2 L03
FERBINTEANU Marilena S5 L09 S5 P31
FERIDOONNEZHAD R. S3 L02
FETECĂU Grigore S5 P13
FIFERE Nicusor, S1 P44
FILIMON Nicoleta, S4 P20
FILIP Viviana S4 P07
FILOTI G. S1 O01
FLORICA Camelia, S1 P40 S1 P36 S1 P37
FOCSA C. S2 L09
FRONTASYEVA Marina V. S5 P09 S5 P21
INDEX
FRUMOSU F., S1 P24
FRUNZA Ligia, S1 P40
FRUNZA Stefan, S1 P40
FRUTH Victor S3 P03
FUNKNER S. S5 L02
FURUYA T. S1 P07 S5 L02
G
GAFTON Vasilica S1 P19
GALASSI C. S1 P17
GALCA A.C. S1 P26
GALES Sydney S2 L011
GANEA Constantin Paul S1 O02 S1 P45 S1 P46
GAROI F., S5 P03
GARTNER Mariuca S3 P03
GAŞIN P. S4 P04
GAVREA R. C. S1 P42
GAZA Oana S3 P04
GEAMBASU C. D. S1 P45,
GEAMBAŞU D. S1 P07 S4 P02
GEORGESCU Adrian S5 P13
GEORGESCU Lucian S4 P24
GEORGESCU Serban S2 OP2 S2 P20
GHEBOIANU Anca Irina S4 P10 S4 P08
GHEBOIANU Anca S5 P21 S5 L10 S5 P12
GHELMEZ (DUMITRU) Mihaela S6 P01
GHENESCU M. S1 P60
GHENESCU Veta S1 P60
GHEORGHE Lucian, S2 OP4
GHEORGHIES Constantin S1 P05 S5 P09
GHIORGHITA Liliana S1 P47
GHITA Dan Gabriel S3 P01 S3 P03 S3 P04 S3
P20
GHITA Rodica, S5 P16
GHITA V. Rodica, S1 P32 S1 P24
GIRTAN Mihaela S1 P59
GÎRŢU A. Mihai S5 P33 S5 P32 S5 P31 S5 L09
GIULIANI Gianluca S3 L01
GRADINARU Luiza, S1 P43
GRECU A. T. S3 P14
GRECULEASA Simona G. S1 O01
GRIGORE O. S2 OP3
GRIGORESCU C. S2 L03
GRIGORIU Constantin, S0 06
GRUIAN C., S1 P33 S1 P34
GRÜNWALD Johannes S2 P19 S2 L01
GUBCEAC Ghennadii, S1 P04
GUDYMA Iu. S1 P51 S1 P52
GURAU Daniela S3 P05 S5 P06
GURGU Valentin S5 P29
GURLUI S. S2 L09
H
HANGA Catalin S3 P07
HARALAMBOUS H, S5 P05
HATU C. S6 L01
HAYASHI J. S0 01
HIRIAN R. S1 P41
HITRUC Gabriela, S1 P43
HOMOCIANU Mihaela, S1 P44
224
HRIB Andrei S2 P13
I
IACOB N. S1 O03 S1 P08
IACOMI F. S1 L15 S1 P54 S1 P55
IFTIMIE Sorina S1 P60 S1 P59
IGHIGEANU Daniel S2 P03 S2 P05 S2 P06 S2
P04
IGNAT M. S5 P15
IGNATENKO Oleg V. S5 P09
INCULEŢ I., S4 P04
INOMATA D. S0 01
IOANE Dumitru S5 P07 S5 P11
ION Alexandru S1 P56
ION L. S1 P59 S1 P60
ION Rodica S4 P10
ION Rodica-Mariana S4 P08
IONASCU L. S3 P10
IONESCU A. S1 P16
IONESCU C. S1 P02 S3 P16 S1 P01
IONESCU Constantin S4 P03
IONESCU Cristina, S4 P05
IONESCU Paul S3 P20
IONESCU Viorel S5 P25
IONITA Codrina, S2 L01 S2 P19
IONITA Marius Giorgian S5 P29
IORDACHE I. S2 P14
IORDAN Alexandra R S1 P19
IORGA Ioan S3 P18 S5 P06
IOVU Horia S3 P04
ISNARD O. S1 P41
ISTRATE Gabriel S4 P19
ISVORAN Adriana S4 P01 S4 P14 S4 P20
ITCESCU Catalina, S4 P24
IVASHKO V., S1 P52
IVANESCU Madalina S3 P22
IWAMAE A. S5 L02
IZMAILOVA Dina S5 P01
J
JAKIMOVSKI Boro S4 P11
JAKIMOVSKI Dragan S4 P11
JEPU I. S1 O01 S2 L03 S5 P02
JINGA V. S1 P02
JINGA Sorin Ion S1 O02
JIPA Florin S2 L07
JIPA Alexandru S3 P06
JOVANOVSKI Jane S4 P11
K
KARAUSH N. N., S5 L01
KILIÇ Adnan S3 P11 S3 P12
KISKINOVA Maya S1 L01
KISS A. S2 L04
KLYUKANOV A., S4 P04
KOCAK Fatma S2 P15
KOVÁCS A. S4 L02
KOVÁCS G. S5 L12 S1 P33 S1 P34
KOVACS Katalin S2 P09 S2 P10
KOVÁCS-KRAUSZ Z. S4 L02
INDEX
KOZLENKO D. S1 L16
KUDRNA P. S2 L02
KULIKOV Sergey S3 P13
KULYUK Leonid S2 L06
KUNCSER A. S1 O01
KUNCSER Victor S1 P06 S1 O01 S1 O03 S1 P08
L
LAZARESCU M.F. S1 P24
LEMASSON Q. S3 P08
LIBERMAN M.A. S2 P11
LIPPERT T. S1 L13
LOGOFATU Constantin S5 P16 S1 P24
LUCHIAN Tudor S4 P06
LUCULESCU Catalin S2 L010 S2 P08 S2 L03
LUKIN M. D. S1 L17
LUNGU Antoanetta, S5 OP2
LUNGU C.P. S1 O01 S1 L14 S1 P29 S2 L03
LUNGU Emil S5 P29
LUNGU Jeanina S1 P56 S5 P32
LUNGU M. S2 L03 S5 P02
LUNGU Mihai S5 OP2
LUNGULESCU Eduard Marius S3 P13
M
MAGYARI K., S1 P33 S1 P34
MAHLER Beatrice S1 P09
MAJOR B. S2 P10
MAKSYMOV A. S1 P51 S1 P52
MALAESCU I. S1 P18
MALLET R. S1 P59
MANAILA Elena S2 P03S2 P04 S2 P05 S2 P06
MANDES Aurelia S2 P02 S2 L05 S2 P01 S1 L14
MANGALAGIU Ionel S4 P12 S4 P13
MANOLESCU B. S1 P09
MANTU Dorina, S4 P12
MANU Radu S1 O02 S1 P23 S1 P30 S1 P31
MARCIU M. S3 OP2
MARCU A. S2 L03
MARDARE Diana S1 P47
MARIN A. M. S2 P16
MARIN A. S2 L03
MARIN C. N. S1 P18
MARIN Irina S6 P02
MARIN Lenuta S5 P18
MARINESCU Mădălina S3 P13
MARMUREANU A. S5 P20 S5 P34
MARTINEZ-CONDE Susana S4 P06
MATEESCU A. O. S1 P01S1 P02
MATEESCU G. S1 P02 S1 P01
MATEI Cristina S2 OP2 S2 P20
MATEI E., S1 P36 S1 P37
MCCAMY Michael B. S4 P06
MEDIANU V. R., S5 P03
MEHLMANN Franz, S2 L01 S2 P19
MICAN S. S1 P38 S1 P41 S1 P42 S1 P20
MICLAUS S. S4 P16
MICLOS Sorin, S5 P28
MIHAI Simona S4 P07
MIHAILESCU I. N. S1 L18 S2 P14
225
MIHAILESCU N. S1 L18
MIHALACHE I., S1 P25
MINAEV B. F., S5 L01
MINAEVA V. A. S5 L01
MISHEV Anastas S4 P11
MITA Carmen S2 P13
MITOSERIU L. S1 P17
MITU Bogdana S2 OP1
MOCA C. P. S1 L17
MOLDOVAN Adrian Septimiu S5 P22
MOLDOVAN Iren-Adelina S5 P22 S5 P24 S4 P03
S5 P23
MOLDOVEANU Costel S4 P13 S4 P12
MOLDOVEANU Ionut-Alexandru, S6 P01
MORJAN Ion S0 06 S2 L011
MOSCALU Florin S1 P53
MOSKALENKO S.A. S2 P11
MUNTEANU D. S1 P02
MURARIU Gabriel, S1 P50 S1 P58, S4 P23 S4
P24
MUSA Gogebakan S1 P14
MUSTATA I. S1 P29
N
NADEJDE Claudia S4 P18
NEAGU Liviu S2 L011
NEAMŢU B. V. S1 P42
NECULAE Adrian, S5 OP2
NEDA Zoltan S4 P19 S4 P21 S4 L02
NEDELCU Liviu S1 O02 S1 P39 S1 P07 S1 P45
S1 P46
NEGREA D. S3 OP3
NEGRILA Catalin Constantin, S5 P16 S1 P24 S1
P39,
NEGRUTIU Meda, S5 OP3
NEGUT C.D. S5 L04
NEMNES G. A. S4 OP1
NICA P. S2 L09
NICA Valentin S1 P19
NICOARA Irina S1 L11 S1 P57
NICOLESCU V. S1 L14
NICOLIN Alexandru I. S4 L03
NICU M. S3 P10
NICULAE D. S3 P16
NIEHUES G. S5 L02
NISHIZAWA S. S5 L02
NISTOR Nicusor S1 P05
NITA C. S2 P14
NOVIKOV B.V. S2 P11
O
OANCEA-STANESCU I.M. S1 L14 S3 OP4 S4
P22
OHTSU Yasunori S5 L03
OLARU L. S1 P54
OLARU N. S1 P54
OPARIUC-DAN Cristian S6 L02
OPREA I. Corneliu S5 L09 S5 P31 S5 P32 S5 P33
OPRICA L. S4 P16
OPTICAN L. S4 P17
INDEX
OSIAC M. S2 L09
OSTAFE Vasile, S4 P20
OZAWA S. S5 L02
P
PACESILA Doru Gheorghe S3 P01 S3 P04 S3 P20
PACHECO Claire S3 P08
PALADE P. S1 O01 S1 O03
PALADE Petru S1 P06
PALADI Florentin S1 P04
PALAMARU Mircea N S1 P19
PALLA PAPAVLU A. S1 L13
PANA I. S2 L04
PANA Iulian, S2 P17
PANAIT Petre S5 L09 S5 P31 S5 P32 S5 P33
PANTELICĂ Ana S3 P18 S3 P19 S3 P20
PAP Zs. S5 L12 S1 P33 S1 P34
PAPP I. S4 L02
PARAU Anca, S2 P17
PARSAN Florin S4 P09
PARVULESCU V.I. S5 L11
PĂŞCUŢĂ Petru S1 P12
PAVEL Nicolae S4 P09 S2 L07 S2 P08 S2 OP3
PAVELESCU Alexandru Octavian S5 P06
PELINESCU Diana S2 OP1
PERINA Vratislav S2 L08
PETERKA M. S2 L02
PETRĂŞESCU L. S1 P29 S1 P30 S1 P31 S1 P23
PETRE D. S6 P04
PETRESCU S. M. S1 L18
PETRIS M., S3 P02
PETROVICI M., S3 P02
PICĂ Elena Maria, S1 P12 S1 P10
PICHON L. S3 P08
PILICER E. S3 P17
PILICER Ercan S2 P15 S3 P12
PİLİÇER F. B. S2 P12
PILICER Fatma Belgin S3 P12
PINTILIE L. S1 P26
PIRAUX Luc S1 L10
PLACINTA Anica Otilia S5 P22
PLUGARU R. S1 P25
PODLESNY I.V. S2 P11
PODOLEANU Adrian GH. S5 OP4
POLOSAN S. S1 L12
POMPILIAN O. S2 L03 S5 P02
POP V. S1 L06 S1 P20 S1 P38 S1 P41 S1 P42
POPA Cristina L. S1 P32
POPA Mihaela S5 P22
POPA P.D. S5 P15 S1 P27
POPA Paula, S4 P23
POPESCU Ion V. S4 P07 S4 P08 S4 P09 S4 P10
S5 P30 S5 P12 S5 L10 S3 P22
POPESCU Iuliana S4 P01
POPESCU Sebastian S5 L03
POPESCU-PELIN G. S2 P14
POROŞNICU C. S1 L14 S1 P29 S1 P30 S1 P31
S1 O01 S2 L03 S5 P02
PREDA N. S1 P35 S1 P36 S1 P37
PREDOI Daniela, S1 P32
226
PREPELITA P. S1 P48 S5 P03
PRETEGIANI, E. S4 P17
PRIOTEASA I. S1 P23 S1 P31 S1 P29
PRODAN Gabriel S1 P22 S1 P53 S1 P23 S5 L08
S1 L14 S1 P30 S1 P31
R
RACLES Carmen, S1 P43
RACOLTA Petru Mihai S3 P01 S3 P03
RADA Marius S1 P13
RADA Simona, S1 P13 S1 P12 S1 P11 S1 P10
RADU A. S1 P59 S1 P60
RADU T., S1 P33 S1 P34
RADULESCU Cristiana S4 P08 S5 P30 S5 L10
RADULESCU L., S3 P02
RAMANANTOANINA Harry S5 L06
RAPORTARU Mihaela Carina S4 P11
RĂSLEANU D., S6 P04
RASOAGA O.L. S2 P14
RASOGA O. S1 P35
RATA R. G. S3 P16
REZLESCU E. S1 P27 S5 P15
REZLESCU N. S1 P27 S5 P15
RISTOSCU C. S1 L18
ROSCA A.C. S4 P22
ROSCA Tudor S2 P07
ROTARU Adrian Ionut S3 P01
ROTARU Adrian S1 P61 S1 P62
ROUZEE A. S2 P10
RUFA, A. S4 P17
RUNCEANU Victor Alexandru S3 P01
RUNCEANU Victor S1 P62 S1 P61
RUS Loredana, S1 P10 S1 P12 S1 P13
RUSU C. S1 P49
RUSU Daniela S1 P05
RUSU Tiberiu, S1 P13
S
SADAN Ozcan S1 P15
SALAMU Gabriela S2 L07
SAMOILA C. S1 P02
SANDEL Simion., S2 L010
SANDULESCU N. S3 OP3
SARBU Ionela S2 OP1
SATULU Veronica S2 OP1
SAU J. D. S1 L17
SAVA Tiberiu Bogdan S3 P04
SAVASTRU Dan S5 P26 S5 P27 S5 P28
SAVASTRU Roxana, S5 P26
SAVASTRU Roxana, S5 P27 S5 P28
SCARLAT Anişoara S3 P18 S3 P19 S3 P20
SCARLAT E.I. S4 L04
SCHINTEIE G. S1 O01 S1 O03 S1 P08 S1 P29
SCHNEIDER Bernd S. S2 L01 S2 P19
SCHRITTWIESER Roman, S2 L01, S2 P19
SCHÜTTE B. S2 P10
SCURTU R., S4 P04
SERBAN A. T. S3 P16
SERBAN Adrian S5 P07 S5 P11
SERIANI Nicola S1 L02
INDEX
SETNESCU R. S5 P12
SETNESCU Radu S3 P13 S4 P08 S4 P10 S5 P21
SETNESCU T. S5 P12 S3 P13 S4 P08 S4 P10 S5
P21
SFARLOAGA P. S1 P18
SHIMAMURA K. S0 01
SIMA Cristina Mihaela S1 P22
SIMA F. S1 L18 S2 P14
SIMA L. E. S1 L18
SIMION Corina Anca S3 P04
SIMION V. S3 P02
SINESCU Cosmin, S5 OP4
SIRBU L. S1 P16
SOCOL G. S2 P14
SOCOL M. S1 P35 S1 P36 S1 P37
SOMACESCU Simona S2 OP1
ŞOPU Daniel, S1 L09
SOUCEK Pavel, S2 L08
SPOREA Dan, S0 06
STAICU D. S2 P16
STAMATE Daniela S5 L09 S5 P31 S5 P32
STANCIU George S2 P08
STANCIU I. S1 P38 S1 P20
STANCU Alexandru S5 P08
STANCULESCU A. S1 P35 S2 P14
STANCULESCU F. S1 P35
STANCULESCU R. S1 P17
ŞTEF Laura S1 P03
STEF Marius, S1 P57 S1 L11
STEFAN Angela S2 OP2 S2 P20
STEFANOV C., S4 P22
STELESCU Maria Daniela S2 P05 S2 P06
STIHI C. S5 L10
STIRBESCU Raluca S5 P30
STIUBIANU George, S1 P43
STOICANESCU M. S1 P35
STRATICIUC Mihai S3 P01 S3 P03
T
TAGHIZADE M. S3 L02
TAIRA Takunori S0 03
TAKACS A., S1 P20
TAKACS A.F. S1 P38
TANI M. S1 P07 S5 L02
TAPAN İ. S2 P12
TATARINGA Gabriela S4 P13
TAUTAN Marina, S5 P28
TENEA Ecaterina S3 P03
TEODORESCU Cristian-Mihail S1 L07
TESILEANU O. S3 L04
TETEAN R. S1 P49
TICHÝ M. S2 L02
TICOS C. M. S2 L03
TICOS Catalin, S0 06
TIGAU Nicolae S1 P50 S1 P58
TIGOIANU Ionut Radu, S1 P44
TIMOFTI Mihaela, S4 P23
TISEANU I. S5 P02
TITORENCU I. S2 L04
TOADER D. S1 P08
227
TOADER Victorin Emilian S5 P22 S4 P03
TOKSOY ONER E. S1 L18
TOMA Lucica Grigora S5 P30
TOMA Octavian S2 OP2 S2 P20
TOMA-DANILA Dragos S5 P22 S5 P23
TOPA Catalina, S4 P24
TOPALA Florin, S5 OP4
TOŞA V. S2 P10
TOSA Valer S2 P09
TOTH G. S4 L02
TRANDAFIR Adrian S5 L09
TRANDAFIR Anamaria S5 L09
TRINCA L.M. S1 P26
TRUPINA L., S1 P45
TRUPINA Lucian, S1 P39
TRUSCA R. S1 P55
TSUZUKI S. S5 L02
ŢUCĂ Carmen S3 P18
TURCANU C. S3 P10
TUTUN Ş.G. S1 P23 S1 P29 S1 P30 S1 P31
U
UJVARI K. Szerena S4 P19
UNGUREANU R. S2 L03 S2 OP3
UR Calin Alexandru S0 04
URLAND Werner S5 L06
URSESCU D. S2 L03
URSESCU Daniel S2 L011
URSUTIU D. S1 P02
UTA Alexandra-Cristina S4 P18
V
VINETICU N. S1 P23
VARARU Irina V S1 P19
VARGA L. S4 L02
VARGA Melinda S4 P19
VARJÚ K. S2 P10
VASILE E. S1 L14 S1 P29 S1 P30 S1 P31
VASILE E. S1 P55
VASILESCU Catalina-Andreea S2 P08
VASILIU Alexandru Marian, S3 P04
VASINA Petr, S2 L08
VEKAS L. S1 O03 S1 P08
VIERU Gheorghe S3 P15
VÍLLORA E.G. S0 01
VINETICU Nicoleta S1 O02
VISAN A. S2 P14
VITELARU C. S2 L04
VLAD Angelica, S1 P43
VLADESCU A. S2 L04
VLADESCU Alina, S2 P17 S2 P18
VLĂDOIU Diana Larisa, S4 P20
VLĂDOIU R. S1 L14 S1 P30 S1 P31
VLADOIU R. S2 L03
VLADOIU Rodica, S2 L05 S2 P01 S2 P02
VLAIC P. S1 L16
VLAICU Gheorghe S4 P07 S4 P09 S4 P10
VLAZAN P. S1 P18
VOCHITA G. S4 P16
VOCHITA Gabriela S4 P18
INDEX
VOICU Flavius S2 L07 S2 OP4
VOICULESCU A. S1 P16
VOICULESCU Ana-Maria S2 OP2 S2 P20
VRAKKING M.J.J. S2 P10
VRYONIDES P S5 P05
VULPOI A., S1 P33 S1 P34
W
WEBER P. S2 P10
WEYMANN I. S1 L17
YAMAMOTO K. S5 L02
YAO N. Y. S1 L17
YILDIRIM Esra S2 P15
Z
ZACREŢCHI Flavian Mihai S5 P08
ZAGRAI Mioara, S1 P10 S1 P12 S1 P13
ZAK Alla S3 P01
ZALTARIOV Mirela, S1 P43 S1 P44
ZAMFIR N.V. S2 L011 S3 L04
ZAMFIRESCU Marian S2 L07 S2 L010
ZAMFIRESCU S., S4 P22
ZANÁŠKA M. S2 L02
ZARAND G. S1 L17
ZBANCIOC Ana Maria S4 P13
ZBANCIOC Gheorghiţă S4 P13 S4 P12
ZGURA I. S2 P14 S1 P36 S1 P37
ZGURA Irina, S1 P40
ZHENG H. S3 L01
ZOITA Nicolae Catalin, S2 P18
ZORAN Maria, S5 P26 S5 P27 S5 P28
ZORILA Bogdan S4 P05
ZORILA Florina Lucica, S4 P05
ZORLIU Adrian S3 P18
ZUBCOV Elena S5 P04
ZUBCOV Natalia S5 P04
ZUS Roxana S6 L03
228

Book of Abstracts

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