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Sample records for reaction anneal time

  1. Enhancing Ductility of 1045 Nanoeutectic Steel Prepared by Aluminothermic Reaction through Annealing at 873 K

    Directory of Open Access Journals (Sweden)

    Zhengning Li

    2017-01-01

    Full Text Available The 1045 steel with lamellar spacing of pearlite in nanometer was prepared by aluminothermic reaction casting and annealed at 873 K (600°C with different time. Microstructures of steels were investigated by X-ray diffraction (XRD, scanning electron microscope (SEM, and transmission electron microscope (TEM. Tensile properties of the steels were measured. The results showed that the lamellar spacing of the pearlite increased with the annealing time. It was found that the microstructure of steels consisted of nanocrystalline-ferrite matrix and laminar pearlite phase. The average grain sizes of the ferrite were 26.9, 27.0, 26.1, and 34.9 nm for the cast steel and samples annealed for 2, 4, and 6 h, respectively. As the annealing time increased, the volume fraction of the pearlite almost remained constant, while the laminar spacing of pearlite increased from 146 to 300 nm. The tensile and yield strength varied slightly; the elongation obviously improved. After annealing for 4 h, the elongation increased to be 33%, which was the reported highest value for the steel up to now and about twice of the conventional 1045 steel.

  2. Interface reactions between Pd thin films and SiC by thermal annealing and SHI irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Njoroge, E.G., E-mail: eric.njoroge@up.ac.za [Department of Physics, University of Pretoria, Pretoria (South Africa); Theron, C.C. [Department of Physics, University of Pretoria, Pretoria (South Africa); Skuratov, V.A. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Wamwangi, D. [School of Physics, University of Witwatersrand, Johannesburg (South Africa); Hlatshwayo, T.T. [Department of Physics, University of Pretoria, Pretoria (South Africa); Comrie, C.M. [MRD, iThemba LABS, P.O. Box 722, Somerset West 7129 (South Africa); Malherbe, J.B. [Department of Physics, University of Pretoria, Pretoria (South Africa)

    2016-03-15

    The solid-state reactions between Pd thin films and 6H-SiC substrates induced by thermal annealing, room temperature swift heavy ion (SHI) irradiation and high temperature SHI irradiation have been investigated by in situ and real-time Rutherford backscattering spectrometry (RBS) and Grazing incidence X-ray diffraction (GIXRD). At room temperature, no silicides were detected to have formed in the Pd/SiC samples. Two reaction growth zones were observed in the samples annealed in situ and analysed by real time RBS. The initial reaction growth region led to formation of Pd{sub 3}Si or (Pd{sub 2}Si + Pd{sub 4}Si) as the initial phase(s) to form at a temperature of about 450 °C. Thereafter, the reaction zone did not change until a temperature of 640 °C was attained where Pd{sub 2}Si was observed to form in the reaction zone. Kinetic analysis of the initial reaction indicates very fast reaction rates of about 1.55 × 10{sup 15} at cm{sup −2}/s and the Pd silicide formed grew linear with time. SHI irradiation of the Pd/SiC samples was performed by 167 MeV Xe{sup 26+} ions at room temperature at high fluences of 1.07 × 10{sup 14} and 4 × 10{sup 14} ions/cm{sup 2} and at 400 °C at lower fluences of 5 × 10{sup 13} ions/cm{sup 2}. The Pd/SiC interface was analysed by RBS and no SHI induced diffusion was observed for room temperature irradiations. The sample irradiated at 400 °C, SHI induced diffusion was observed to occur accompanied with the formation of Pd{sub 4}Si, Pd{sub 9}Si{sub 2} and Pd{sub 5}Si phases which were identified by GIXRD analysis.

  3. Finite-time thermodynamics and simulated annealing

    International Nuclear Information System (INIS)

    Andresen, B.

    1989-01-01

    When the general, global optimization technique simulated annealing was introduced by Kirkpatrick et al. (1983), this mathematical algorithm was based on an analogy to the statistical mechanical behavior of real physical systems like spin glasses, hence the name. In the intervening span of years the method has proven exceptionally useful for a great variety of extremely complicated problems, notably NP-problems like the travelling salesman, DNA sequencing, and graph partitioning. Only a few highly optimized heuristic algorithms (e.g. Lin, Kernighan 1973) have outperformed simulated annealing on their respective problems (Johnson et al. 1989). Simulated annealing in its current form relies only on the static quantity 'energy' to describe the system, whereas questions of rate, as in the temperature path (annealing schedule, see below), are left to intuition. We extent the connection to physical systems and take over further components from thermodynamics like ensemble, heat capacity, and relaxation time. Finally we refer to finite-time thermodynamics (Andresen, Salomon, Berry 1984) for a dynamical estimate of the optimal temperature path. (orig.)

  4. Al/Ni metal intermetallic composite produced by accumulative roll bonding and reaction annealing

    International Nuclear Information System (INIS)

    Mozaffari, A.; Hosseini, M.; Manesh, H. Danesh

    2011-01-01

    Highlights: → Al/Ni metallic composites produced by accumulative roll bonding were heat treated at different temperatures and periods, to investigate the effect of reaction annealing on the structure and mechanical properties. → Based on the annealing conditions, various intermetallic phases were formed. The structure and composition of the composites were detected by SEM and XRD techniques. → The strength of the initial metallic composite can be improved due to the formation of the hard intermetallic phases, by the heat treatment process. - Abstract: In this research, Al/Ni multilayers composites were produced by accumulative roll bonding and then annealed at different temperatures and durations. The structure and mechanical properties of the fabricated metal intermetallic composites (MICs) were investigated. Scanning electron microscopy and X-ray diffraction analyses were used to evaluate the structure and composition of the composite. The Al 3 Ni intermetallic phase is formed in the Al/Ni interface of the samples annealed at 300 and 400 deg. C. When the temperature increased to 500 deg. C, the Al 3 Ni 2 phase was formed in the composite structure and grew, while the Al 3 Ni and Al phases were simultaneously dissociated. At these conditions, the strength of MIC reached the highest content and was enhanced by increasing time. At 600 deg. C, the AlNi phase was formed and the mechanical properties of MIC were intensively degraded due to the formation of structural porosities.

  5. Reduction of Annealing Times for Energy Conservation in Aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Anthony D. Rollett; Hasso Weiland; Mohammed Alvi; Abhijit Brahme

    2005-08-31

    Carnegie Mellon University was teamed with the Alcoa Technical Center with support from the US Dept. of Energy (Office of Industrial Technology) and the Pennsylvania Technology Investment Authority (PTIA) to make processing of aluminum less costly and more energy efficient. Researchers in the Department of Materials Science and Engineering have investigated how annealing processes in the early stages of aluminum processing affect the structure and properties of the material. Annealing at high temperatures consumes significant amounts of time and energy. By making detailed measurements of the crystallography and morphology of internal structural changes they have generated new information that will provide a scientific basis for shortening processing times and consuming less energy during annealing.

  6. Microstructure and electrical-optical properties of cesium tungsten oxides synthesized by solvothermal reaction followed by ammonia annealing

    International Nuclear Information System (INIS)

    Liu Jingxiao; Ando, Yoshihiko; Dong Xiaoli; Shi Fei; Yin Shu; Adachi, Kenji; Chonan, Takeshi; Tanaka, Akikazu; Sato, Tsugio

    2010-01-01

    Cesium tungsten oxides (Cs x WO 3 ) were synthesized by solvothermal reactions using ethanol and 57.1 vol% ethanol aqueous solution at 200 o C for 12 h, and the effects of post annealing in ammonia atmosphere on the microstructure and electrical-optical properties were investigated. Agglomerated particles consisting of disk-like nanoparticles and nanorods of Cs x WO 3 were formed in the pure ethanol and ethanol aqueous solutions, respectively. The samples retained the original morphology and crystallinity after annealing in ammonia atmosphere up to 500 o C, while a small amount of nitrogen ion were incorporated in the lattice. The as-prepared Cs x WO 3 sample showed excellent near infrared (NIR) light shielding ability as well as high transparency in the visible light region. The electrical resistivity of the pressed pellets of the powders prepared in pure ethanol and 57.1 vol% ethanol aqueous solution greatly decreased after ammonia annealing at 500 o C, i.e., from 734 to 31.5 and 231 to 3.58 Ω cm, respectively. - Graphical abstract: Cesium tungsten oxides (Cs x WO 3 ) with different morphology were synthesized by solvothermal reaction, and the effects of post-ammonia annealing on the microstructure and electrical-optical properties were investigated.

  7. Annealing Time Effect on Nanostructured n-ZnO/p-Si Heterojunction Photodetector Performance

    Science.gov (United States)

    Habubi, Nadir. F.; Ismail, Raid. A.; Hamoudi, Walid K.; Abid, Hassam. R.

    2015-02-01

    In this work, n-ZnO/p-Si heterojunction photodetectors were prepared by drop casting of ZnO nanoparticles (NPs) on single crystal p-type silicon substrates, followed by (15-60) min; step-annealing at 600∘C. Structural, electrical, and optical properties of the ZnO NPs films deposited on quartz substrates were studied as a function of annealing time. X-ray diffraction studies showed a polycrystalline, hexagonal wurtizte nanostructured ZnO with preferential orientation along the (100) plane. Atomic force microscopy measurements showed an average ZnO grain size within the range of 75.9 nm-99.9 nm with a corresponding root mean square (RMS) surface roughness between 0.51 nm-2.16 nm. Dark and under illumination current-voltage (I-V) characteristics of the n-ZnO/p-Si heterojunction photodetectors showed an improving rectification ratio and a decreasing saturation current at longer annealing time with an ideality factor of 3 obtained at 60 min annealing time. Capacitance-voltage (C-V) characteristics of heterojunctions were investigated in order to estimate the built-in-voltage and junction type. The photodetectors, fabricated at optimum annealing time, exhibited good linearity characteristics. Maximum sensitivity was obtained when ZnO/Si heterojunctions were annealed at 60 min. Two peaks of response, located at 650 nm and 850 nm, were observed with sensitivities of 0.12-0.19 A/W and 0.18-0.39 A/W, respectively. Detectivity of the photodetectors as function of annealing time was estimated.

  8. Implantation annealing by scanning electron beam

    International Nuclear Information System (INIS)

    Jaussaud, C.; Biasse, B.; Cartier, A.M.; Bontemps, A.

    1983-11-01

    Samples of ion implanted silicon (BF 2 , 30keV, 10 15 ions x cm -2 ) have been annealed with a multiple scan electron beam, at temperatures ranging from 1000 to 1200 0 C. The curves of sheet resistance versus time show a minimum. Nuclear reaction measurements of the amount of boron remaining after annealing show that the increase in sheet resistance is due to a loss of boron. The increase in junction depths, measured by spreading resistance on bevels is between a few hundred A and 1000 A [fr

  9. Interfacial reaction pathways and kinetics during annealing of 111-textured Al/TiN bilayers: A synchrotron x-ray diffraction and transmission electron microscopy study

    International Nuclear Information System (INIS)

    Chun, J.-S.; Desjardins, P.; Lavoie, C.; Petrov, I.; Cabral, C. Jr.; Greene, J. E.

    2001-01-01

    Growth of TiN layers in most diffusion-barrier applications is limited to deposition temperatures T s s =450 deg. C on SiO 2 by ultrahigh vacuum reactive magnetron sputter deposition in pure N 2 . Al overlayers, 160 nm thick with inherited 111 preferred orientation, were then deposited at T s =100 deg. C without breaking vacuum. The as-deposited TiN layer is underdense due to the low deposition temperature (T s /T m ≅0.23 in which T m is the melting point) resulting in kinetically limited adatom mobilities leading to atomic shadowing which, in turn, results in a columnar microstructure with both inter- and intracolumnar voids. The Al overlayer is fully dense. Synchrotron x-ray diffraction was used to follow interfacial reaction kinetics during postdeposition annealing of the 111-textured Al/TiN bilayers as a function of time (t a =12-1200 s) and temperature (T a =440-550 deg. C). Changes in bilayer microstructure and microchemistry were investigated using transmission electron microscopy (TEM) and scanning TEM to obtain compositional maps of plan-view and cross-sectional specimens. Interfacial reaction during annealing is initiated at the Al/TiN interface. Al diffuses rapidly into TiN voids during anneals at temperatures ∼ 3 Ti at the interface. Al 3 Ti exhibits a relatively planar growth front extending toward the Al free surface. Analyses of time-dependent x-ray diffraction peak intensities during isothermal annealing as a function of temperature show that Al 3 Ti growth kinetics are, for the entire temperature range investigated, diffusion limited with an activation energy of 1.5±0.2 eV

  10. Effect of Anneal temperature and Time on Change of Texture and Hardness of Al-Cu-Mg

    International Nuclear Information System (INIS)

    Masrukan; Adolf Asih, S.

    2000-01-01

    Observation of the effect of annealing temperature to its texture and hardness of the Al-Cu-Mg has been done. In this experiments aluminium alloy powder and 5 pieces cubes of this alloy with size of 8 x 8 x 8 mm 3 were used. The powder was not annealed, 2 pieces cube were annealed for 20 hours at temperatures of 200 o C and 300 o respectively, finally 3 pieces cube were annealed at temperature of 400 o C. Texture measurement was done using x-ray diffraction with wave length of 1.78892 A using inverse pole figure method. The hardness testing results at constant temperature of 400 o C and various time indicated that the hardness values are decreased with increasing annealed time. Also, at hardness testing for constant time and various annealing temperatures indicated that the hardness values decreased with increasing annealing temperature

  11. Rapid thermal pulse annealing

    International Nuclear Information System (INIS)

    Miller, M.G.; Koehn, B.W.; Chaplin, R.L.

    1976-01-01

    Characteristics of recovery processes have been investigated for cases of heating a sample to successively higher temperatures by means of isochronal annealing or by using a rapid pulse annealing. A recovery spectra shows the same features independent of which annealing procedure is used. In order to determine which technique provides the best resolution, a study was made of how two independent first-order processes are separated for different heating rates and time increments of the annealing pulses. It is shown that the pulse anneal method offers definite advantages over isochronal annealing when annealing for short time increments. Experimental data by means of the pulse anneal techniques are given for the various substages of stage I of aluminium. (author)

  12. Germanium nanoislands grown by radio frequency magnetron sputtering: Annealing time dependent surface morphology and photoluminescence

    International Nuclear Information System (INIS)

    Samavati, Alireza; Othaman, Z.; Ghoshal, S. K.; Amjad, R. J.

    2013-01-01

    Structural and optical properties of ∼ 20 nm Ge nanoislands grown on Si(100) by radio frequency (rf) magnetron sputtering under varying annealing conditions are reported. Rapid thermal annealing at a temperature of 600°C for 30 s, 90 s, and 120 s are performed to examine the influence of annealing time on the surface morphology and photoluminescence properties. X-ray diffraction spectra reveal prominent Ge and GeO 2 peaks highly sensitive to the annealing time. Atomic force microscope micrographs of the as-grown sample show pyramidal nanoislands with relatively high-density 10 11 cm −2) ). The nanoislands become dome-shaped upon annealing through a coarsening process mediated by Oswald ripening. The room temperature photoluminescence peaks for both as-grown 3.29 eV) and annealed 3.19 eV) samples consist of high intensity and broad emission, attributed to the effect of quantum confinement. The red shift (∼0.10 eV) of the emission peak is attributed to the change in the size of the Ge nanoislands caused by annealing. Our easy fabrication method may contribute to the development of Ge nanostructure-based optoelectronics. (interdisciplinary physics and related areas of science and technology)

  13. Annealing effects in solid-state track recorders

    International Nuclear Information System (INIS)

    Gold, R.; Roberts, J.H.; Ruddy, F.H.

    1981-01-01

    Current analyses of the annealing process in Solid State Track Recorders (SSTR) reveal fundamental misconceptions. The use of the Arrhenius equation to describe the decrease in track density resulting from annealing is shown to be incorrect. To overcome these deficiencies, generalized reaction rate theory is used to describe the annealing process in SSTR. Results of annealing experiments are used to guide this theoretical formulation. Within this framework, the concept of energy per etchable defect for SSTR is introduced. A general correlation between sensitivity and annealing susceptibility in SSTR is deduced. In terms of this general theory, the apparent correlation between fission track size and fission track density observed under annealing is readily explained. Based on this theoretical treatment of annealing phenomena, qualitative explanations are advanced for current enigmas in SSTR cosmic ray work

  14. Through-vial impedance spectroscopy of the mechanisms of annealing in the freeze-drying of maltodextrin: the impact of annealing hold time and temperature on the primary drying rate.

    Science.gov (United States)

    Smith, Geoff; Arshad, Muhammad Sohail; Polygalov, Eugene; Ermolina, Irina

    2014-06-01

    The study aims to investigate the impact of annealing hold time and temperature on the primary drying rate/duration of a 10% (w/v) solution of maltodextrin with an emphasis on how the mechanisms of annealing might be understood from the in-vial measurements of the ice crystal growth and the glass transition. The electrical impedance of the solution within a modified glass vial was recorded between 10 and 10(6) Hz during freeze-drying cycles with varying annealing hold times (1-5 h) and temperatures. Primary drying times decreased by 7%, 27% and 34% (1.1, 4.3 and 5.5 h) with the inclusion of an annealing step at temperatures of -15°C, -10°C and -5°C, respectively. The glass transition was recorded at approximately -16°C during the re-heating and re-cooling steps, which is close to the glass transition (Tg ') reported for 10% (w/v) maltodextrin and therefore indicates that a maximum freeze concentration (∼86%, w/w, from the Gordon-Taylor equation) was achieved during first freezing, with no further ice being formed on annealing. This observation, coupled to the decrease in electrical resistance that was observed during the annealing hold time, suggests that the reduction in the drying time was because of improved connectivity of ice crystals because of Ostwald ripening rather than devitrification. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  15. The influence of annealing temperature and time on the efficiency of pentacene: PTCDI organic solar cells

    Directory of Open Access Journals (Sweden)

    Mehmet Biber

    Full Text Available In this study, fabrication of a polycyclic aromatic hydrocarbon/Perylene Tetracarboxylic Di-Imide (PTCDI, donor/acceptor solar cells are presented using physical vapour deposition technique in a 1000 class glove box. An ITO/PEDOT:PSS/Pentacene/PTCDI/Al (ITO = Indium Tin Oxide and PEDOT:PSS = poly(3,4-ethylenedioxythiophene polystyrene sulfonate solar cell has been obtained and the power conversion efficiency, PCE (η of about 0.33% has been obtained under simulated solar illumination of 300 W/m2. Furthermore, the effects of annealing temperatures (at 100 and 150 °C and of annealing (at 100 °C times for 5 and 10 min. on the power conversion efficiency, η of the solar cells have also been investigated. In general, it has been seen that the thermal annealing deteriorated the characteristics parameters of Pentacene/PTCDI solar cell such that both fill factor, FF and η decreased after annealing and with increase of annealing time. Atomic force microscopy (AFM images showed that the phase segregation and grain size increased and the surface roughness of Pentacene film decreased and these effects reduced the η value. The η values of the solar cell have been determined as 0.33%, 0.12% and 0.06% for pre-annealing, annealing at 100 and 150 °C, respectively. Keywords: Organic solar cells, PTCDI, Pentacene, Annealing

  16. Effects of annealing time on the structure, morphology, and stress of gold–chromium bilayer film

    International Nuclear Information System (INIS)

    Zhang Hong; Wang Hu; Huang Hao-Peng; Jin Yun-Xia; Kong Fang-Yu; Cui Yun

    2016-01-01

    In this work, a 200-nm-thick gold film with a 10-nm-thick chromium layer used as an adhesive layer is fabricated on fused silica by the electron beam evaporation method. The effects of annealing time at 300 °C on the structure, morphology and stress of the film are studied. We find that chromium could diffuse to the surface of the film by formatting a solid solution with gold during annealing. Meanwhile, chromium is oxidized on the surface and diffused downward along the grain grooves in the gold film. The various operant mechanisms that change the residual stresses of gold films for different annealing times are discussed. (paper)

  17. Dissolution kinetics of small amounts of oxygen in tantalum alloy T-111 and internal oxide displacement reactions during annealing

    Science.gov (United States)

    Stecura, S.

    1976-01-01

    Oxygen was added to T-111 (Ta-8W-2Hf, wt. %) at 820 and 990 C at an oxygen pressure of about 0.0003 torr. The technique employed permitted predetermined and reproducible doping of T-111 up to 3.0 at. % oxygen. Based on the temperature dependence of the doping reaction, it is concluded that the initial rates of oxygen pickup are probably controlled by solution of oxygen into the T-111 lattice. Although hafnium oxides are more stable than those of tantalum or tungsten, analyses of extracted residues indicate that the latter oxides predominate in the as-doped specimens, presumably because of the higher concentrations of tantalum and tungsten in the alloy. However, high-temperature annealing promotes gettering of dissolved oxygen and of other oxides to form hafnium oxides. Small amounts of tantalum and tungsten oxides were still present after high-temperature annealing. Tungsten oxide (WO3) volatilizes slightly from the surface of T-111 at 990 C. The vaporization of WO3 has no apparent affect on the doping reaction.

  18. Effects of hydrothermal annealing on characteristics of CuInS{sub 2} thin films by SILAR method

    Energy Technology Data Exchange (ETDEWEB)

    Shi Yong, E-mail: sys-99@163.com [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Sciences and Technology, Dalian University of Technology, Dalian 116024 (China); Xue Fanghong [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Sciences and Technology, Dalian University of Technology, Dalian 116024 (China); Li Chunyan [School of Materials, Dalian University of Technology, Dalian 116024 (China); Zhao Qidong; Qu Zhenping; Li Xinyong [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Sciences and Technology, Dalian University of Technology, Dalian 116024 (China)

    2012-07-15

    CuInS{sub 2} thin films have been deposited by successive ionic layer absorption and reaction (SILAR) method, then annealed in a Na{sub 2}S solution (denoted as hydrothermal annealing) at 200 Degree-Sign C for different time. The effect of hydrothermal annealing on the properties of the films was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and optical absorption spectroscopy. The XRD, TEM and SEM results indicate that well-crystallized CuInS{sub 2} films could be obtained after annealing in 0.1 mol/L Na{sub 2}S solution for 1.5 h. The annealed CuInS{sub 2} films were slightly S-rich and the direct band gap varied from 1.32 to 1.58 eV as the annealing time increased from 0.5 h to 2 h.

  19. Thermal annealing in neutron-irradiated tribromobenzenes

    DEFF Research Database (Denmark)

    Siekierska, K.E.; Halpern, A.; Maddock, A. G.

    1968-01-01

    in the crystals was estimated by means of the 1,2-dibromoethylene exchange technique. The results suggest that, as a consequence of nuclear events, quite a number of different reactions occur whereas the principal annealing reaction is a recombination of atomic bromine with a dibromophenyl radical....

  20. Thermal annealing and recoil reactions of 128I atoms in thermal neutron activated iodate-nitrate mixed crystals

    International Nuclear Information System (INIS)

    Mishra, S.P.; Sharma, R.B.

    1983-01-01

    Recoil reaction of 128 I atoms in neutron irradiated mixed crystals (iodate-nitrate) have been studied by thermal annealing methods. The retention of 128 I (i.e. radioactivity of 128 I retained in the parent chemi cal form) decreases sharply in the beginning and then attains saturation value with the increase in concentration of nitrate. The annealing followed the usual characteristic pattern, viz., a steep rise in retention within the first few minutes and then a saturation value thereafter but these saturation values in case of mixed crystals are lower in comparison to those of pure iodate targets. The process obeys simple first order kinetics and the activation energy obtained are of lower order than those obtained in case of pure targets. The results are discussed in the light of present ideas and the role of nitrate ion and its radiolytic products have also been invoked. (author)

  1. Strong white photoluminescence from annealed zeolites

    International Nuclear Information System (INIS)

    Bai, Zhenhua; Fujii, Minoru; Imakita, Kenji; Hayashi, Shinji

    2014-01-01

    The optical properties of zeolites annealed at various temperatures are investigated for the first time. The annealed zeolites exhibit strong white photoluminescence (PL) under ultraviolet light excitation. With increasing annealing temperature, the emission intensity of annealed zeolites first increases and then decreases. At the same time, the PL peak red-shifts from 495 nm to 530 nm, and then returns to 500 nm. The strongest emission appears when the annealing temperature is 500 °C. The quantum yield of the sample is measured to be ∼10%. The PL lifetime monotonously increases from 223 μs to 251 μs with increasing annealing temperature. The origin of white PL is ascribed to oxygen vacancies formed during the annealing process. -- Highlights: • The optical properties of zeolites annealed at various temperatures are investigated. • The annealed zeolites exhibit strong white photoluminescence. • The maximum PL enhancement reaches as large as 62 times. • The lifetime shows little dependence on annealing temperature. • The origin of white emission is ascribed to the oxygen vacancies

  2. Defect production in simulated cascades: Cascade quenching and short-term annealing

    International Nuclear Information System (INIS)

    Heinisch, H.L.

    1983-01-01

    Defect production in displacement cascades in copper has been modeled using the MARLOWE code to generate cascades and the stochastic annealing code ALSOME to simulate cascade quenching and short-term annealing of isolated cascades. Quenching is accomplished by using exaggerated values for defect mobilities and for critical reaction distances in ALSOME for a very short time. The quenched cascades are then short-term annealed with normal parameter values. The quenching parameter values were empirically determined by comparison with results of resistivity measurements. Throughout the collisional, quenching and short-term annealing phases of cascade development, the high energy cascades continue to behave as a collection of independent lower energy lobes. For recoils above about 30 keV the total number of defects and the numbers of free defects scale with the damage energy. As the energy decreases from 30 keV, defect production varies with the changing nature of the cascade configuration, resulting in more defects per unit damage energy. The simulated annealing of a low fluence of interacting cascades revealed an interstitial shielding effect on depleted zones during Stage I recovery. (orig.)

  3. Effects of Annealing Time on the Performance of OTFT on Glass with ZrO2 as Gate Dielectric

    Directory of Open Access Journals (Sweden)

    W. M. Tang

    2012-01-01

    Full Text Available Copper phthalocyanine-based organic thin-film transistors (OTFTs with zirconium oxide (ZrO2 as gate dielectric have been fabricated on glass substrates. The gate dielectric is annealed in N2 at different durations (5, 15, 40, and 60 min to investigate the effects of annealing time on the electrical properties of the OTFTs. Experimental results show that the longer the annealing time for the OTFT, the better the performance. Among the devices studied, OTFTs with gate dielectric annealed at 350°C in N2 for 60 min exhibit the best device performance. They have a small threshold voltage of −0.58 V, a low subthreshold slope of 0.8 V/decade, and a low off-state current of 0.73 nA. These characteristics demonstrate that the fabricated device is suitable for low-voltage and low-power operations. When compared with the TFT samples annealed for 5 min, the ones annealed for 60 min have 20% higher mobility and nearly two times smaller the subthreshold slope and off-state current. The extended annealing can effectively reduce the defects in the high-k film and produces a better insulator/organic interface. This results in lower amount of carrier scattering and larger CuPc grains for carrier transport.

  4. Effect of annealing time on morphological characteristics of Ba(Zr,Ti)O3 thin films

    International Nuclear Information System (INIS)

    Cavalcante, L.S.; Anicete-Santos, M.; Pontes, F.M.; Souza, I.A.; Santos, L.P.S.; Rosa, I.L.V.; Santos, M.R.M.C.; Santos-Junior, L.S.; Leite, E.R.; Longo, E.

    2007-01-01

    Ba(Zr 0.50 Ti 0.50 )O 3 thin films were prepared by the polymeric precursor method using the annealing low temperature of 300 o C for 8, 16, 24, 48, 96 and 192h in a furnace tube with oxygen atmosphere. The X-ray diffraction patterns revealed that the film annealed for 192 h presented some crystallographic planes (1bar 0bar 0) (1bar 1bar 0) and (2bar 0bar 0) in its crystalline lattice. Fourier transformed infrared presented the formation of metal-oxygen stretching at around 756cm -1 . The atomic force microscopy analysis presented the growth of granules in the Ba(Zr 0.50 Ti 0.50 )O 3 films annealed from 8 to 96h. The crystalline film annealed for 192h already presents grains in its perovskite structure. It evidenced a reduction in the thickness of the thin films with the increase of the annealing time

  5. Annealing-induced interfacial reactions and the effects on the electrical properties of Ga doped ZnO/CuxS contacts to p-GaN

    International Nuclear Information System (INIS)

    Gu, Wen; Wu, Xingyang; Song, Peng; Zhang, Jianhua

    2015-01-01

    Highlights: • The electrical properties of GZO/CuS x contacts to p-GaN annealed at different temperatures in air have been studied. • Ohmic contacts were formed by annealing the contacts at 500 and 600 °C in air. • The oxygen in air was found to be essential for the formation of ohmic contact. • The possible formation mechanism of the ohmic contacts was illustrated. - Abstract: Ga-doped ZnO (GZO) contacts to p-GaN were investigated by using Cu x S interlayers under different annealing temperatures. It is shown that the GZO/Cu x S contacts annealed at 300 and 400 °C for 3 min in air exhibited non-ohmic characteristics. However, annealing the contacts at 500 and 600 °C in air resulted in linear current–voltage characteristics. The lowest specific contact resistivity of 1.66 × 10 −2 Ω cm 2 was obtained for the contact annealed at 500 °C. To account for the formation mechanism of the ohmic contact, AES and XPS were used to analyze the interfacial properties of the GZO/Cu x S/p-GaN and Cu x S/p-GaN interfaces, respectively. The possible reasons were discussed in detail, suggesting that the interfacial reactions and atomic diffusions are thought to be responsible for forming such a low contact resistance

  6. Quantitative Identification of the Annealing Degree of Apatite Fission Tracks Using Terahertz Time Domain Spectroscopy (THz-TDS).

    Science.gov (United States)

    Wu, Hang; Wu, Shixiang; Qiu, Nansheng; Chang, Jian; Bao, Rima; Zhang, Xin; Liu, Nian; Liu, Shuai

    2018-01-01

    Apatite fission-track (AFT) analysis, a widely used low-temperature thermochronology method, can provide details of the hydrocarbon generation history of source rocks for use in hydrocarbon exploration. The AFT method is based on the annealing behavior of fission tracks generated by 238 U fission in apatite particles during geological history. Due to the cumbersome experimental steps and high expense, it is imperative to find an efficient and inexpensive technique to determinate the annealing degree of AFT. In this study, on the basis of the ellipsoid configuration of tracks, the track volume fraction model (TVFM) is established and the fission-track volume index is proposed. Furthermore, terahertz time domain spectroscopy (THz-TDS) is used for the first time to identify the variation of the AFT annealing degree of Durango apatite particles heated at 20, 275, 300, 325, 450, and 500 ℃ for 10 h. The THz absorbance of the sample increases with the degree of annealing. In addition, the THz absorption index is exponentially related to annealing temperature and can be used to characterize the fission-track volume index. Terahertz time domain spectroscopy can be an ancillary technique for AFT thermochronological research. More work is urgently needed to extrapolate experimental data to geological conditions.

  7. Chemical vapour deposition at atmospheric pressure of graphene on molybdenum foil: Effect of annealing time on characteristics and corrosion stability of graphene coatings

    International Nuclear Information System (INIS)

    Naghdi, Samira; Jevremović, Ivana; Mišković-Stanković, Vesna; Rhee, Kyong Yop

    2016-01-01

    Highlights: • Atmospheric pressure chemical vapor deposition of graphene on molybdenum foils. • Quality and domain size of graphene layers increased with longer annealing times. • The number of graphene layers decreased with longer annealing times. • Graphene coatings on molybdenum foils exhibited corrosion inhibitive properties. - Abstract: In this work, the effect of pre-annealing of Mo substrate on the quality of graphene layers grown by chemical vapour deposition was investigated by X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy. Moreover, different electrochemical techniques were employed to investigate the corrosion stability of the graphene coated Mo in 0.1 M NaCl. Longer annealing time resulted in less defective graphene coatings with fewer layers. Graphene coating on the annealed Mo provided better protection against corrosion during the initial exposure times, while after prolonged exposure times, both graphene coatings on annealed and non-annealed Mo exhibited nearly the same corrosion inhibitive properties.

  8. Very fast simulated re-annealing

    OpenAIRE

    L. Ingber

    1989-01-01

    Draft An algorithm is developed to statistically find the best global fit of a nonlinear non-convex cost-function over a D-dimensional space. It is argued that this algorithm permits an annealing schedule for ‘‘temperature’’ T decreasing exponentially in annealing-time k, T = T0 exp(−ck1/D). The introduction of re-annealing also permits adaptation to changing sensitivities in the multidimensional parameter-space. This annealing schedule is faster than fast Cauchy annealing, ...

  9. Correlating defect density with growth time in continuous graphene films.

    Science.gov (United States)

    Kang, Cheong; Jung, Da Hee; Nam, Ji Eun; Lee, Jin Seok

    2014-12-01

    We report that graphene flakes and films which were synthesized by copper-catalyzed atmospheric pressure chemical vapor deposition (APCVD) method using a mixture of Ar, H2, and CH4 gases. It was found that variations in the reaction parameters, such as reaction temperature, annealing time, and growth time, influenced the domain size of as-grown graphene. Besides, the reaction parameters influenced the number of layers, degree of defects and uniformity of the graphene films. The increase in growth temperature and annealing time tends to accelerate the graphene growth rate and increase the diffusion length, respectively, thereby increasing the average size of graphene domains. In addition, we confirmed that the number of pinholes reduced with increase in the growth time. Micro-Raman analysis of the as-grown graphene films confirmed that the continuous graphene monolayer film with low defects and high uniformity could be obtained with prolonged reaction time, under the appropriate annealing time and growth temperature.

  10. Annealing time dependence of the physical, electrical and pH response characteristics of spin coated TiO2 thin films

    International Nuclear Information System (INIS)

    Zulkefle, M A; Rahman, R A; Yusoff, K A; Herman, S H; Abdullah, W F H; Rusop, M

    2015-01-01

    Titanium dioxide (TiO 2 ) thin film was deposited on indium tin oxide (ITO) substrate and used as sensing membrane of EGFET pH sensor. The thin film was fabricated using sol- gel spin coating method. All samples were annealed at 400 °C but the annealing time was varied. This is done to study the effects of annealing time on physical and electrical properties of titanium dioxide thin film. The sensitivity of each sample towards H + ion was measured and result shows that sample annealed for 45 minutes has the highest sensitivity (52.6 mV/pH). It is found that increasing annealing duration will increase the pH sensitivity but a limit will be reached at certain point. Longer annealing processes done beyond this point will results in lower pH sensitivity. (paper)

  11. Time-resolved photoluminescence of Ga(NAsP) multiple quantum wells grown on Si substrate: Effects of rapid thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Woscholski, R., E-mail: ronja.woscholski@physik.uni-marburg.de; Shakfa, M.K.; Gies, S.; Wiemer, M.; Rahimi-Iman, A.; Zimprich, M.; Reinhard, S.; Jandieri, K.; Baranovskii, S.D.; Heimbrodt, W.; Volz, K.; Stolz, W.; Koch, M.

    2016-08-31

    Time-resolved photoluminescence (TR-PL) spectroscopy has been used to study the impact of rapid thermal annealing (RTA) on the optical properties and carrier dynamics in Ga(NAsP) multiple quantum well heterostructures (MQWHs) grown on silicon substrates. TR-PL measurements reveal an enhancement in the PL efficiency when the RTA temperature is increased up to 925 °C. Then, the PL intensity dramatically decreases with the annealing temperature. This behavior is explained by the variation of the disorder degree in the studied structures. The analysis of the low-temperature emission-energy-dependent PL decay time enables us to characterize the disorder in the Ga(NAsP) MQWHs. The theoretically extracted energy-scales of disorder confirm the experimental observations. - Highlights: • Ga(NAsP) multiple quantum well heterostructures (MQWHs) grown on silicon substrates • Impact of rapid thermal annealing on the optical properties and carrier dynamics • Time resolved photoluminescence spectroscopy was applied. • PL transients became continuously faster with increasing annealing temperature. • Enhancement in the PL efficiency with increasing annealing temperature up to 925 °C.

  12. Time-resolved photoluminescence of Ga(NAsP) multiple quantum wells grown on Si substrate: Effects of rapid thermal annealing

    International Nuclear Information System (INIS)

    Woscholski, R.; Shakfa, M.K.; Gies, S.; Wiemer, M.; Rahimi-Iman, A.; Zimprich, M.; Reinhard, S.; Jandieri, K.; Baranovskii, S.D.; Heimbrodt, W.; Volz, K.; Stolz, W.; Koch, M.

    2016-01-01

    Time-resolved photoluminescence (TR-PL) spectroscopy has been used to study the impact of rapid thermal annealing (RTA) on the optical properties and carrier dynamics in Ga(NAsP) multiple quantum well heterostructures (MQWHs) grown on silicon substrates. TR-PL measurements reveal an enhancement in the PL efficiency when the RTA temperature is increased up to 925 °C. Then, the PL intensity dramatically decreases with the annealing temperature. This behavior is explained by the variation of the disorder degree in the studied structures. The analysis of the low-temperature emission-energy-dependent PL decay time enables us to characterize the disorder in the Ga(NAsP) MQWHs. The theoretically extracted energy-scales of disorder confirm the experimental observations. - Highlights: • Ga(NAsP) multiple quantum well heterostructures (MQWHs) grown on silicon substrates • Impact of rapid thermal annealing on the optical properties and carrier dynamics • Time resolved photoluminescence spectroscopy was applied. • PL transients became continuously faster with increasing annealing temperature. • Enhancement in the PL efficiency with increasing annealing temperature up to 925 °C

  13. Effects of post-stress hydrogen annealing on MOS oxides after 60Co irradiation or Fowler-Nordheim injection

    International Nuclear Information System (INIS)

    Saks, N.S.; Stahlbush, R.E.; Mrstik, B.J.; Rendell, R.W.; Klein, R.B.

    1993-01-01

    Changes in interface trap density D it have been determined in MOSFETs as a function of time during hydrogen annealing at 295K. Large increases in D it are observed during H 2 annealing in MOSFETs previously stressed by either 60 Co irradiation or Fowler-Nordheim electron injection. The annealing behavior is very similar for both types of stress, which suggests that the D it creation mechanism involves similar chemistry for hydrogen reactions. Studies of the time dependence of D it creation as a function of MOSFET gate length show that the time dependence is limited primarily by lateral diffusion of molecular hydrogen (H 2 ) through the gate oxide. An activation energy of 0.57 eV, which is consistent with H 2 diffusion, is obtained from the temperature dependence

  14. The effect of electrochemical CO annealing on platinum–cobalt nanoparticles in acid medium and their correlation to the oxygen reduction reaction

    International Nuclear Information System (INIS)

    Ciapina, Eduardo G.; Ticianelli, Edson A.

    2011-01-01

    Highlights: ► Modification of the surface properties of Pt 3 Co/C electrocatalyst. ► Electrochemical CO annealing in acid media generated a Pt-rich surface. ► In situ XAS revealed modifications in the Pt 5d band occupancy after CO annealing. ► The CO-annealed sample exhibited stronger interaction with oxygenated species. ► Increased Pt utilization in the CO-annealed Pt 3 Co/C electrocatalyst. - Abstract: This paper describes a modification of the surface properties of a carbon-supported Pt 3 Co catalyst resulting from an electrochemical cycling treatment in a 0.1 M HClO 4 and in a CO-saturated 0.1 M HClO 4 solution (electrochemical CO-annealing). The procedure generated a Pt-rich surface with electrochemical properties different from that presented by the as-received (untreated) sample. This was evidenced by a shift in the CO stripping peak to more positive potentials in the CO stripping voltammetry, and by an increased charge of H upd region and a modification of the oxide reduction peak observed in the base cyclic voltammogram. In situ X-ray absorption spectroscopy experiments conducted in the dispersive mode revealed differences in the electronic 5d band occupancy after the CO annealing, whereas the behavior of the intensity of the white-line as function of the potential for this material approached that found for pure Pt/C nanoparticles, in contrast to the small potential dependence profile exhibited by the as-received Pt 3 Co nanoparticles. Mass activities towards the oxygen reduction reaction measured by rotating disk experiments carried out at 1600 rpm in a O 2 -saturated solution at 25 °C increased from 0.10 A/mg of Pt to 0.19 A/mg of Pt, evidencing the higher Pt utilization in the CO-annealed Pt 3 Co/C electrocatalyst. The origin of the different electrochemical behavior is discussed.

  15. Investigation of the evolution of nitrogen defects in flash-lamp-annealed InGaZnO films and their effects on transistor characteristics

    Science.gov (United States)

    Eom, Tae-Yil; Ahn, Chee-Hong; Kang, Jun-Gu; Saad Salman, Muhammad; Lee, Sun-Young; Kim, Yong-Hoon; Lee, Hoo-Jeong; Kang, Chan-Mo; Kang, Chiwon

    2018-06-01

    In this study, we show the evolution of nitrogen defects during a sol–gel reaction in flash-lamp-annealed InGaZnO (IGZO) films and their effects on the device characteristics of their thin-film transistors (TFTs). The flash lamp annealing (FLA) of the IGZO TFT for 16 s helps achieve a mobility of approximately 7 cm2 V‑1 s‑1. However, further extension of the annealing time results only in drastic increases in carrier concentration and off-current. The X-ray photoelectron spectroscopy (XPS) analysis of the N 1s peak unravels the presence of oxygen-vacancy-associated nitrogen defects and their evolution with annealing time, which is possibly responsible for the increase in carrier concentration.

  16. Annealing of chemical radiation damage in zirconium nitrate

    International Nuclear Information System (INIS)

    Mahamood, Aysha; Chandunni, E.; Nair, S.M.K.

    1979-01-01

    A kinetic study of the annealing of γ-irradiation damage in zirconium nitrate is presented. The annealing can be represented as a combination of a first order and a second order process. It is considered that the first order process is the combination of close correlated pairs of Osup(-) and NO fragments and the second order process involves the single reaction of random recombination of the fragments throughout the crystal. (auth.)

  17. Annealing behavior of alpha recoil tracks in phlogopite

    International Nuclear Information System (INIS)

    Gao Shaokai; Yuan Wanming; Dong Jinquan; Bao Zengkuan

    2005-01-01

    Alpha recoil tracks (ARTs) formed during the a-decay of U, Th as well as their daughter nuclei are used as a new dating method which is to some extent a complementarity of fission track dating due to its ability to determine the age of young mineral. ARTs can be observable under phase-contrast interference microscope through chemical etching. In order to study the annealing behavior of ARTs in phlogopite, two methods of annealing experiments were executed. Samples were annealed in the electronic tube furnace at different temperatures ranging from 250 degree C to 450 degree C in steps of 50 degree C. For any given annealing temperature, different annealing times were used until total track fading were achieved. It is found that ARTs anneal much more easily than fission tracks, the annealing ratio increase non-linearly with annealing time and temperature. Using the Arrhenius plot, an activation energy of 0.68ev is finally found for 100% removal of ARTs, which is less than the corresponding value for fission tracks (FTs). Through extending the annealing time to geological time, a much lower temperature range of the sample's cooling history can be got.

  18. Simulated annealing with constant thermodynamic speed

    International Nuclear Information System (INIS)

    Salamon, P.; Ruppeiner, G.; Liao, L.; Pedersen, J.

    1987-01-01

    Arguments are presented to the effect that the optimal annealing schedule for simulated annealing proceeds with constant thermodynamic speed, i.e., with dT/dt = -(v T)/(ε-√C), where T is the temperature, ε- is the relaxation time, C ist the heat capacity, t is the time, and v is the thermodynamic speed. Experimental results consistent with this conjecture are presented from simulated annealing on graph partitioning problems. (orig.)

  19. Annealing time dependent up-conversion luminescence enhancement in magnesium–tellurite glass

    Energy Technology Data Exchange (ETDEWEB)

    Amjad, Raja J., E-mail: rajajunaid25@gmail.com [Advanced Optical Material Research Group, Faculty of Science, Universiti Teknologi Malaysia, Skudai, Johor bahru 81310 (Malaysia); Centre for Solid State Physics, University of the Punjab, QAC, Lahore 54590 (Pakistan); Sahar, M.R.; Ghoshal, S.K.; Dousti, M.R. [Advanced Optical Material Research Group, Faculty of Science, Universiti Teknologi Malaysia, Skudai, Johor bahru 81310 (Malaysia); Riaz, S. [Centre for Solid State Physics, University of the Punjab, QAC, Lahore 54590 (Pakistan); Samavati, A.R.; Arifin, R. [Advanced Optical Material Research Group, Faculty of Science, Universiti Teknologi Malaysia, Skudai, Johor bahru 81310 (Malaysia); Naseem, S. [Centre for Solid State Physics, University of the Punjab, QAC, Lahore 54590 (Pakistan)

    2013-04-15

    Silver nanoparticles (NPs) embedded Er{sup 3+} ions doped magnesium–tellurite glasses are prepared using melt quenching technique. Heat treatment with different time intervals above the glass transition temperature is applied in order to reduce the silver ions (Ag{sup +}) to silver NPs (Ag{sup o}). The transmission electron microscopy (TEM), differential thermal analyses (DTA), UV–vis-NIR absorption spectroscopy and photoluminescence (PL) spectroscopy are used to examine annealing time dependent structural and optical properties. The characteristics temperatures such as glass transition temperature (T{sub g}), crystallization temperature (T{sub c}) and melting temperature (T{sub m}) obtained from DTA for an as prepared sample are 322 °C, 450 °C and 580 °C, respectively. TEM image clearly shows the homogeneous distribution of silver NPs with an average diameter ∼12 nm. The observed localized surface plasmon resonance (LSPR) band is evidenced at 534 nm. Furthermore, the infrared to visible frequency up-conversion (UC) emission under 786 nm excitation exhibits three emission bands centered at 532 nm, 554 nm and 634 nm corresponding to {sup 2}H{sub 11/2}→{sup 4}I{sub 15/2}, {sup 4}S{sub 3/2}→{sup 4}I{sub 15/2} and {sup 4}F{sub 9/2}→{sup 4}I{sub 15/2} transitions of Er{sup 3+}, respectively. Intensity of all the bands is found to enhance by increasing the annealing time up to 24 h. However, further increase in the annealing time duration (∼40 h) reduces the intensity. Enhancement in the luminescence intensity is understood in terms of the local field effect of the silver NPs whereas the quenching is attributed to the energy transfer from Er{sup 3+} ions to silver NPs. -- Highlights: ► Er{sup 3+}-doped silver NPs embedded magnesium–tellurite glasses are prepared. ► TEM confirms the successful precipitation of spherical NPs by heat treatment (HT). ► Luminescence is enhanced due to the growth of NPs after HT up to 24 h. ► With HT>24 h (40 h

  20. Mathematical foundation of quantum annealing

    International Nuclear Information System (INIS)

    Morita, Satoshi; Nishimori, Hidetoshi

    2008-01-01

    Quantum annealing is a generic name of quantum algorithms that use quantum-mechanical fluctuations to search for the solution of an optimization problem. It shares the basic idea with quantum adiabatic evolution studied actively in quantum computation. The present paper reviews the mathematical and theoretical foundations of quantum annealing. In particular, theorems are presented for convergence conditions of quantum annealing to the target optimal state after an infinite-time evolution following the Schroedinger or stochastic (Monte Carlo) dynamics. It is proved that the same asymptotic behavior of the control parameter guarantees convergence for both the Schroedinger dynamics and the stochastic dynamics in spite of the essential difference of these two types of dynamics. Also described are the prescriptions to reduce errors in the final approximate solution obtained after a long but finite dynamical evolution of quantum annealing. It is shown there that we can reduce errors significantly by an ingenious choice of annealing schedule (time dependence of the control parameter) without compromising computational complexity qualitatively. A review is given on the derivation of the convergence condition for classical simulated annealing from the view point of quantum adiabaticity using a classical-quantum mapping

  1. Comparison between thermal annealing and ion mixing of alloyed Ni-W films on Si. I

    International Nuclear Information System (INIS)

    Pai, C.S.; Lau, S.S.; Poker, D.B.; Hung, L.S.

    1985-01-01

    The reactions between Ni-W alloys and Si substrates induced by thermal annealing and ion mixing were investigated and compared. Samples were prepared by sputtering of Ni-W alloys, both Ni-rich and W-rich, onto the Si substrates, and followed by either furnace annealing (200--900 0 C) or ion mixing (2 x 10 15 -- 4 x 10 16 86 Kr + ions/cm 2 ). The reactions were analyzed by Rutherford backscattering and x-ray diffraction (Read camera). In general, thermal annealing and ion mixing lead to similar reactions. Phase separation between Ni and W with Ni silicides formed next to the Si substrate and W silicide formed on the surface was observed for both Ni-rich and W-rich samples under thermal annealing. Phase separation was also observed for Ni-rich samples under ion mixing; however, a Ni-W-Si ternary compound was possibly formed for ion-mixed W-rich samples. These reactions were rationalized in terms of the mobilities of various atoms and the energetics of the systems

  2. Effects of deposition temperature and in-situ annealing time on structure and magnetic properties of (001) orientation FePt films

    International Nuclear Information System (INIS)

    Yu, Yongsheng; George, T.A.; Li, Haibo; Sun, Daqian; Ren, Zhenan; Sellmyer, D.J.

    2013-01-01

    FePt films were prepared on (100) oriented single crystal MgO substrates at high temperature ranging from 620 until 800 °C and in-situ annealed for different times ranging from 0 to 60 min to obtain ordered FePt films. The structural analysis indicates that FePt films grow epitaxially on MgO (100) substrates. Both increasing deposition temperature and in-situ annealing time enhance the (001) texture and ordering of FePt films. The magnetic analysis shows that these L1 0 FePt films have perpendicular anisotropy and the easy magnetization c-axis is perpendicular to the film plane. Magnetization reversal is controlled by a rotational mechanism. The hard magnetic properties of the films are improved with increasing deposition temperature or in-situ annealing time. - Highlights: ► The paper reports the texture and magnetic evolution of FePt films deposited on MgO substrates. ► Increasing deposition temperature or annealing time enhanced the texture and ordering. ► The magnetic analysis shows L1 0 FePt films have perpendicular anisotropy.

  3. Evolution of interface and surface structures of ZnO/Al2 O3 multilayers upon rapid thermal annealing

    Science.gov (United States)

    Liu, H. H.; Chen, Q. Y.; Chang, C. F.; Hsieh, W. C.; Wadekar, P. V.; Huang, H. C.; Liao, H. H.; Seo, H. W.; Chu, W. K.

    2015-03-01

    ZnO ∖Al2O3 multilayers were deposited on sapphires by atomic layer deposition at 85°C. This low substrate temperature ensures good interface smoothness useful for study of interfacial reaction or interdiffusion. Our study aimed at the effects of rapid thermal annealing at different annealing temperatures, times and PAr:PO2. XRR and XRD techniques were used to investigate the kinetics from which various terms of the activation energies could be determined. HR-TEM and electron diffraction were carried out to correlate the microstructures and interfacial alignments as a result of the reactions. AFM were used to assist SEM profiling of the surface morphological evolution in association with the TEM observations.

  4. Reaction time for trimolecular reactions in compartment-based reaction-diffusion models

    Science.gov (United States)

    Li, Fei; Chen, Minghan; Erban, Radek; Cao, Yang

    2018-05-01

    Trimolecular reaction models are investigated in the compartment-based (lattice-based) framework for stochastic reaction-diffusion modeling. The formulae for the first collision time and the mean reaction time are derived for the case where three molecules are present in the solution under periodic boundary conditions. For the case of reflecting boundary conditions, similar formulae are obtained using a computer-assisted approach. The accuracy of these formulae is further verified through comparison with numerical results. The presented derivation is based on the first passage time analysis of Montroll [J. Math. Phys. 10, 753 (1969)]. Montroll's results for two-dimensional lattice-based random walks are adapted and applied to compartment-based models of trimolecular reactions, which are studied in one-dimensional or pseudo one-dimensional domains.

  5. Influence of annealing time on pH sensitivity of ZnO sensing membrane for EGFET sensor

    Science.gov (United States)

    Zulkefle, M. A.; Rahman, R. A.; Yusoff, K. A.; Abdullah, W. F. H.; Rusop, M.; Herman, S. H.

    2018-05-01

    Solid-state materials have becomes essential in recent technological advancements. This study also utilized solid-state material but in form of thin films to sense hydrogen ions in solutions. Fabrication of ZnO thin film was done using sol-gel spin coating technique. In an attempt to increase the pH sensitivity of the produced film, prolonging of annealing time was done. It was found that the increase in annealing time from 15 minutes to 30 minutes had managed to improve the sensitivity by 4.35%. The optimum pH sensitivity and linearity obtained in this study is 50.40 mV/pH and 0.9911 respectively.

  6. Coherent Coupled Qubits for Quantum Annealing

    Science.gov (United States)

    Weber, Steven J.; Samach, Gabriel O.; Hover, David; Gustavsson, Simon; Kim, David K.; Melville, Alexander; Rosenberg, Danna; Sears, Adam P.; Yan, Fei; Yoder, Jonilyn L.; Oliver, William D.; Kerman, Andrew J.

    2017-07-01

    Quantum annealing is an optimization technique which potentially leverages quantum tunneling to enhance computational performance. Existing quantum annealers use superconducting flux qubits with short coherence times limited primarily by the use of large persistent currents Ip. Here, we examine an alternative approach using qubits with smaller Ip and longer coherence times. We demonstrate tunable coupling, a basic building block for quantum annealing, between two flux qubits with small (approximately 50-nA) persistent currents. Furthermore, we characterize qubit coherence as a function of coupler setting and investigate the effect of flux noise in the coupler loop on qubit coherence. Our results provide insight into the available design space for next-generation quantum annealers with improved coherence.

  7. Effects of annealing time on the recovery of Charpy V-notch properties of irradiated high-copper weld metal

    International Nuclear Information System (INIS)

    Iskander, S.K.; Sokolov, M.A.; Nanstad, R.K.

    1994-01-01

    One of the options to mitigate the effects of irradiation on reactor pressure vessels is to thermally anneal them to restore the toughness properties that have been degraded by neutron irradiation. An important issue to be resolved is the effect on the toughness properties of reirradiating a vessel that has been annealed. This paper describes the annealing response of irradiated high-copper submerged-arc weld HSSI 73W. For this study, the weld has been annealed at 454 C (850 F) for lengths of time varying between 1 and 14 days. The Charpy V-notch 41-J (30-ft-lb) transition temperature (TT 41J ) almost fully recovered for the longest period studied, but recovered to a lesser degree for the shorter periods. No significant recovery of the TT 41J was observed for a 7-day anneal at 343 C (650 F). At 454 C for the durations studied, the values of the upper-shelf impact energy of irradiated and annealed weld metal exceeded the values in the unirradiated condition. Similar behavior was observed after aging the unirradiated weld metal at 460 and 490 C for 1 week

  8. Interpretation of microstructure evolution during self-annealing and thermal annealing of nanocrystalline electrodeposits—A comparative study

    DEFF Research Database (Denmark)

    Pantleon, Karen; Somers, Marcel A. J.

    2010-01-01

    and nickel electrodeposits was achieved by time-resolved X-ray diffraction line profile analysis and crystallographic texture analysis during room temperature storage and during isothermal annealing at elevated temperatures. These in-situ studies with unique time resolution allowed quantification of the self-annealing......Electrodeposition results in a non-equilibrium state of the as-deposited nanocrystalline microstructure, which evolves towards an energetically more favorable state as a function of time and/or temperature upon deposition. Real-time investigation of the evolving microstructure in copper, silver...... kinetics of copper and silver electrodeposits as well as the annealing kinetics of electrodeposited nickel. Similarities and characteristic differences of the kinetics and mechanisms of microstructure evolution in the various electrodeposits are discussed and the experimental results are attempted...

  9. Reactor pressure vessel thermal annealing

    International Nuclear Information System (INIS)

    Lee, A.D.

    1997-01-01

    The steel plates and/or forgings and welds in the beltline region of a reactor pressure vessel (RPV) are subject to embrittlement from neutron irradiation. This embrittlement causes the fracture toughness of the beltline materials to be less than the fracture toughness of the unirradiated material. Material properties of RPVs that have been irradiated and embrittled are recoverable through thermal annealing of the vessel. The amount of recovery primarily depends on the level of the irradiation embrittlement, the chemical composition of the steel, and the annealing temperature and time. Since annealing is an option for extending the service lives of RPVs or establishing less restrictive pressure-temperature (P-T) limits; the industry, the Department of Energy (DOE) and the Nuclear Regulatory Commission (NRC) have assisted in efforts to determine the viability of thermal annealing for embrittlement recovery. General guidance for in-service annealing is provided in American Society for Testing and Materials (ASTM) Standard E 509-86. In addition, the American Society of Mechanical Engineers (ASME) Code Case N-557 addresses annealing conditions (temperature and duration), temperature monitoring, evaluation of loadings, and non-destructive examination techniques. The NRC thermal annealing rule (10 CFR 50.66) was approved by the Commission and published in the Federal Register on December 19, 1995. The Regulatory Guide on thermal annealing (RG 1.162) was processed in parallel with the rule package and was published on February 15, 1996. RG 1.162 contains a listing of issues that need to be addressed for thermal annealing of an RPV. The RG also provides alternatives for predicting re-embrittlement trends after the thermal anneal has been completed. This paper gives an overview of methodology and recent technical references that are associated with thermal annealing. Results from the DOE annealing prototype demonstration project, as well as NRC activities related to the

  10. Interpretation of microstructure evolution during self-annealing and thermal annealing of nanocrystalline electrodeposits-A comparative study

    International Nuclear Information System (INIS)

    Pantleon, Karen; Somers, Marcel A.J.

    2010-01-01

    Electrodeposition results in a non-equilibrium state of the as-deposited nanocrystalline microstructure, which evolves towards an energetically more favorable state as a function of time and/or temperature upon deposition. Real-time investigation of the evolving microstructure in copper, silver and nickel electrodeposits was achieved by time-resolved X-ray diffraction line profile analysis and crystallographic texture analysis during room temperature storage and during isothermal annealing at elevated temperatures. These in-situ studies with unique time resolution allowed quantification of the self-annealing kinetics of copper and silver electrodeposits as well as the annealing kinetics of electrodeposited nickel. Similarities and characteristic differences of the kinetics and mechanisms of microstructure evolution in the various electrodeposits are discussed and the experimental results are attempted to be interpreted in terms of recovery, recrystallization and grain growth.

  11. Hp Ge: Purification, crystal growth, and annealing properties

    International Nuclear Information System (INIS)

    Hall, R.N.

    1984-01-01

    The prospects for growing HP Ge crystals of increased size and purity are examined. One interesting approach is to grow dislocation-free crystals, which must then be annealed to reduce the concentration of V 2 H traps. The phenomena which occur during annealing are discussed and compared with experiment. Hydrogen, present in atomic form at the growth temperature, forms H 2 molecules during cooling, causing the effective diffusion coefficient to decrease rapidly. Models representing the reactions between H and the V 2 H, A(H, Si), and D(H,O) complexes are presented and analyzed

  12. Effect of germanium doping on the annealing characteristics of oxygen and carbon-related defects in Czochralski silicon

    International Nuclear Information System (INIS)

    Londos, C. A.; Andrianakis, A.; Sgourou, E. N.; Emtsev, V.; Ohyama, H.

    2010-01-01

    This paper is devoted to the annealing studies of defects produced in carbon-rich Ge-doped Czochralski-grown Si (Cz-Si) by 2 MeV electron irradiation. The annealing temperature of vacancy-oxygen (VO) complexes, carbon interstitial-oxygen interstitial (C i O i ), and carbon interstitial-carbon substitutional (C i C s ) pairs as well as the formation temperature of vacancy-two oxygen (VO 2 ) complexes are monitored as a function of Ge concentration. It has been established that the annealing of C i O i and C i C s defects remains practically unaffected by the Ge presence, whereas the annealing temperature of VO defects and the formation temperature of VO 2 complexes are substantially lowered at Ge concentrations larger than 1x10 19 cm -3 . The hydrostatic component of elastic strains introduced by Ge atoms in the Si crystal lattice was calculated. It appears to be very small, at least insufficient to exert a pronounced effect upon the annealing behavior of radiation-produced defects. This conclusion is in line with what is observed for the C i O i and C i C s species. In the case of VO, whose annealing process in Cz-Si is concurrently conducted by two reaction paths VO+O i →VO 2 and VO+Si I →O i , we suggest that the latter reaction in Ge-doped Cz-Si is enhanced by emitting self-interstitials (Si I ) from loosely bound self-interstitial clusters predominantly formed around Ge impurity atoms. As a result, the liberation of self-interstitials at lower annealing temperatures leads to an enhanced annealing of VO defects. An enhanced formation of VO 2 complexes at lower temperatures is also discussed in terms of other reactions running in parallel with the reaction VO+Si I →O i .

  13. Defect production in simulated cascades: cascade quenching and short-term annealing

    International Nuclear Information System (INIS)

    Heinisch, H.L.

    1982-01-01

    Defect production in high energy displacement cascades has been modeled using the computer code MARLOWE to generate the cascades and the stochastic computer code ALSOME to simulate the cascade quenching and short-term annealing of isolated cascades. The quenching is accomplished by using ALSOME with exaggerated values for defect mobilities and critical reaction distanes for recombination and clustering, which are in effect until the number of defect pairs is equal to the value determined from resistivity experiments at 4K. Then normal mobilities and reaction distances are used during short-term annealing to a point representative of Stage III recovery. Effects of cascade interactions at low fluences are also being investigated. The quenching parameter values were empirically determined for 30 keV cascades. The results agree well with experimental information throughout the range from 1 keV to 100 keV. Even after quenching and short-term annealing the high energy cascades behave as a collection of lower energy subcascades and lobes. Cascades generated in a crystal having thermal displacements were found to be in better agreement with experiments after quenching and annealing than those generated in a non-thermal crystal

  14. Forecasting nonlinear chaotic time series with function expression method based on an improved genetic-simulated annealing algorithm.

    Science.gov (United States)

    Wang, Jun; Zhou, Bi-hua; Zhou, Shu-dao; Sheng, Zheng

    2015-01-01

    The paper proposes a novel function expression method to forecast chaotic time series, using an improved genetic-simulated annealing (IGSA) algorithm to establish the optimum function expression that describes the behavior of time series. In order to deal with the weakness associated with the genetic algorithm, the proposed algorithm incorporates the simulated annealing operation which has the strong local search ability into the genetic algorithm to enhance the performance of optimization; besides, the fitness function and genetic operators are also improved. Finally, the method is applied to the chaotic time series of Quadratic and Rossler maps for validation. The effect of noise in the chaotic time series is also studied numerically. The numerical results verify that the method can forecast chaotic time series with high precision and effectiveness, and the forecasting precision with certain noise is also satisfactory. It can be concluded that the IGSA algorithm is energy-efficient and superior.

  15. Reactions between monolayer Fe and Si(001) surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, M; Kobayashi, N; Hayashi, N [Electrotechnical Lab., Tsukuba, Ibaraki (Japan)

    1997-03-01

    Reactions between 1.5 monolayer(ML) Fe deposited on Si(001)-2x1 and -dihydride surfaces were studied in situ by reflection high-energy electron diffraction and time-of-flight ion scattering spectrometry with the use of 25 keV H ions. The reactions between Fe and Si which were successively deposited on Si(001)-dihydride surface were also studied. After the room temperature deposition Fe reacted with Si(001)-2x1 substrate resulting in the formation of polycrystalline Fe5Si3. By annealing to 560-650degC composite heteroepitaxial layer of both type A and type B {beta}-FeSi2 was formed. On the dihydride surface polycrystalline Fe was observed after 1.5ML Fe deposition at room temperature, and reaction between Fe and Si(001)-dihydride surface is not likely at room temperature. We observed 3D rough surface when we deposited only Fe layer on the dihydride surface and annealed above 700degC. The hydrogen termination of Si(001) surface prevents the deposited Fe from diffusing into the substrate below 500degC, however the annealing above 710degC leads to the diffusion. We obtained 2D ordered surface, which showed 3x3 RHEED pattern as referenced to the primitive unreconstructed Si(001) surface net, when we deposited 2.5ML Fe and 5.8ML Si successively onto Si(001)-dihydride surface and annealed to 470degC. (author)

  16. Production of carbon nanotubes using mechanical milling in the presence of an exothermic reaction

    International Nuclear Information System (INIS)

    Karimi, E.Z.; Zebarjad, S.M.; Khaki, J. Vahdati; Izadi, H.

    2010-01-01

    Carbon nanotubes (CNTs) have shown promising potential for many applications in field of engineering due to their unusual significant properties. A major challenge for the industrial applications of CNTs is the large-quantity production. In this field, one new method for CNT production is annealing the ball milled graphite powder. The annealing process should be done in high temperature (1200-1400 o C) and needs time more than 6 h. The novel process introduced in this paper is elimination the annealing stage thorough a thermite reaction. The necessity heat for the conversion of milling products to CNTs was generated in the milling chamber by an exothermic reaction. In addition, the reaction products acted as catalysts to the CNT formation process. The adiabatic temperatures of 1809, 2000 and 2325 K were selected according to balancing graphite and thermite mixture (Aluminum + Iron oxide powders) for exothermic reaction. The results of thermo gravimetric analysis (TGA) test proved that CNT formation strongly depends on adiabatic temperature. The results of microscopic evaluation done by transition electron microscope (TEM) showed that at higher adiabatic temperature CNTs could be produced.

  17. Mechanical properties and annealing texture of zirconium sheets

    International Nuclear Information System (INIS)

    Hanif-ur-Rehman; Khawaja, F.A.

    1996-01-01

    Mechanical properties like yield strength (YS), ultimate tensile strength(UTS), percentage elongation and annealing texture has been studied in sheets of commercially pure zirconium. The YS and UTS decrease as a function of annealing temperature up to 600 V, but both quantities have maximum value in sample annealed at 800 deg. C. The percentage elongation decreased with increase in annealing temperature up to 600 deg. C. A slight decrease and minimum value of percentage elongation was observed at 650 and 800 C respectively. The texture development in the annealed samples has been studied by the X-ray diffraction method. The sampled annealed at 800 deg. C showed a texture component (0001) [01 bar 10] with orientation density of about 8 times random, while the samples annealed at 600,650 and 700 deg. C showed a texture component (0001)[2 bar 110] with orientation density of about 5 times random. Thus it is concluded, that the texture component (0001)[2 bar 110] and (0001)[01 bar 10] at 650 and 800 geg. C respectively, may be the responsible for the increase in YS and UTS and decrease in percentage elongation at these temperatures. (author)

  18. Thermal annealing studies in muscovite and in quartz

    International Nuclear Information System (INIS)

    Roberts, J.H.; Gold, R.; Ruddy, F.H.

    1979-06-01

    In order to use Solid State Track Recorders (SSTR) in environments at elevated temperatures, it is necessary to know the thermal annealing characteristics of various types of SSTR. For applications in the nuclear energy program, the principal interest is focused upon the annealing of fission tracks in muscovite mica and in quartz. Data showing correlations between changes in track diameters and track densities as a function of annealing time and temperature will be presented for Amersil quartz glass. Similar data showing changes in track lengths and in track densities will be presented for mica. Time-temperature regions will be defined where muscovite mica can be accurately applied with negligible correction for thermal annealing

  19. Typewriting rate as a function of reaction time.

    Science.gov (United States)

    Hayes, V; Wilson, G D; Schafer, R L

    1977-12-01

    This study was designed to determine the relationship between reaction time and typewriting rate. Subjects were 24 typists ranging in age from 19 to 39 yr. Reaction times (.001 sec) to a light were recorded for each finger and to each alphabetic character and three punctuation marks. Analysis of variance yielded significant differences in reaction time among subjects and fingers. Correlation between typewriting rate and average reaction time to the alphabetic characters and three punctuation marks was --.75. Correlation between typewriting rate and the difference between the reaction time of the hands was --.42. Factors influencing typewriting rate may include reaction time of the fingers, difference between the reaction time of the hands, and reaction time to individual keys on the typewriter. Implications exist for instructional methodology and further research.

  20. Isothermal annealing of silicon implanted with 50 keV 10B ions

    International Nuclear Information System (INIS)

    Weidner, B.; Zaschke, G.

    1974-01-01

    Isothermal annealing characteristics of silicon implanted with boron were measured and compared with calculated results. Implantation was performed with 50 keV 10 B ions in the dose range of 7.5 x 10 12 cm -2 to 2.0 x 10 15 cm -2 . Annealing temperatures ranged from 700 to 900 0 C. Maximum annealing time was 10 4 minutes. Annealing time strongly increases with increasing dose and decreasing temperature. Assuming that there is only one activation energy the isothermal annealing curves of constant dose and different temperatures were combined to a reduced annealing curve and the reduced isothermal annealing curve calculated. Starting from first order kinetics, considering the doping profile of boron in silicon and assuming a depth-dependent decay constant the experimentally determined annealing curves could be easily described over the total dose and time range

  1. Influence of multi-deposition multi-annealing on time-dependent dielectric breakdown characteristics of PMOS with high-k/metal gate last process

    International Nuclear Information System (INIS)

    Wang Yan-Rong; Yang Hong; Xu Hao; Wang Xiao-Lei; Luo Wei-Chun; Qi Lu-Wei; Zhang Shu-Xiang; Wang Wen-Wu; Yan Jiang; Zhu Hui-Long; Zhao Chao; Chen Da-Peng; Ye Tian-Chun

    2015-01-01

    A multi-deposition multi-annealing technique (MDMA) is introduced into the process of high-k/metal gate MOSFET for the gate last process to effectively reduce the gate leakage and improve the device’s performance. In this paper, we systematically investigate the electrical parameters and the time-dependent dielectric breakdown (TDDB) characteristics of positive channel metal oxide semiconductor (PMOS) under different MDMA process conditions, including the deposition/annealing (D and A) cycles, the D and A time, and the total annealing time. The results show that the increases of the number of D and A cycles (from 1 to 2) and D and A time (from 15 s to 30 s) can contribute to the results that the gate leakage current decreases by about one order of magnitude and that the time to fail (TTF) at 63.2% increases by about several times. However, too many D and A cycles (such as 4 cycles) make the equivalent oxide thickness (EOT) increase by about 1 Å and the TTF of PMOS worsen. Moreover, different D and A times and numbers of D and A cycles induce different breakdown mechanisms. (paper)

  2. The Effect of Vacuum Annealing of Magnetite and Zero-Valent Iron Nanoparticles on the Removal of Aqueous Uranium

    Directory of Open Access Journals (Sweden)

    R. A. Crane

    2013-01-01

    Full Text Available As-formed and vacuum annealed zero-valent iron nanoparticles (nano-Fe0 and magnetite nanoparticles (nano-Fe3O4 were tested for the removal of uranium from carbonate-rich mine water. Nanoparticles were introduced to batch systems containing the mine water under oxygen conditions representative of near-surface waters, with a uranyl solution studied as a simple comparator system. Despite the vacuum annealed nano-Fe0 having a 64.6% lower surface area than the standard nano-Fe0, similar U removal (>98% was recorded during the initial stages of reaction with the mine water. In contrast, ≤15% U removal was recorded for the mine water treated with both as-formed and vacuum annealed nano-Fe3O4. Over extended reaction periods (>1 week, appreciable U rerelease was recorded for the mine water solutions treated using nano-Fe0, whilst the vacuum annealed material maintained U at <50 μg L−1 until 4 weeks reaction. XPS analysis of reacted nanoparticulate solids confirmed the partial chemical reduction of UVI to UIV in both nano-Fe0 water treatment systems, but with a greater amount of UIV detected on the vacuum annealed particles. Results suggest that vacuum annealing can enhance the aqueous reactivity of nano-Fe0 and, for waters of complex chemistry, can improve the longevity of aqueous U removal.

  3. Annealing-induced Ge/Si(100) island evolution

    International Nuclear Information System (INIS)

    Zhang Yangting; Drucker, Jeff

    2003-01-01

    Ge/Si(100) islands were found to coarsen during in situ annealing at growth temperature. Islands were grown by molecular-beam epitaxy of pure Ge and annealed at substrate temperatures of T=450, 550, 600, and 650 deg. C, with Ge coverages of 6.5, 8.0, and 9.5 monolayers. Three coarsening mechanisms operate in this temperature range: wetting-layer consumption, conventional Ostwald ripening, and Si interdiffusion. For samples grown and annealed at T=450 deg. C, consumption of a metastably thick wetting layer causes rapid initial coarsening. Slower coarsening at longer annealing times occurs by conventional Ostwald ripening. Coarsening of samples grown and annealed at T=550 deg. C occurs via a combination of Si interdiffusion and conventional Ostwald ripening. For samples grown and annealed at T≥600 deg. C, Ostwald ripening of SiGe alloy clusters appears to be the dominant coarsening mechanism

  4. A temperature control method for shortening thermal cycling time to achieve rapid polymerase chain reaction (PCR) in a disposable polymer microfluidic device

    DEFF Research Database (Denmark)

    Bu, Minqiang; Perch-Nielsen, Ivan R.; Sørensen, Karen Skotte

    2013-01-01

    steps to achieve a rapid ramping between the temperature steps for DNA denaturation, annealing and extension. The temperature dynamics within the microfluidic PCR chamber was characterized and the overshooting and undershooting parameters were optimized using the temperature-dependent fluorescence......We present a temperature control method capable of effectively shortening the thermal cycling time of polymerase chain reaction (PCR) in a disposable polymer microfluidic device with an external heater and a temperature sensor. The method employs optimized temperature overshooting and undershooting...

  5. A novel temperature control method for shortening thermal cycling time to achieve rapid polymerase chain reaction (PCR) in a disposable polymer microfluidic device

    DEFF Research Database (Denmark)

    Bu, Minqiang; R. Perch-Nielsen, Ivan; Sørensen, Karen Skotte

    steps to achieve a rapid ramping between the temperature steps for DNA denaturation, annealing and extension. The temperature dynamics within the microfluidic PCR chamber was characterized and the overshooting and undershooting parameters were optimized using the temperature dependent fluorescence......We present a new temperature control method capable of effectively shortening the thermal cycling time of polymerase chain reaction (PCR) in a disposable polymer microfluidic device with external heater and temperature sensor. The method employs optimized temperature overshooting and undershooting...

  6. Quantum Monte Carlo tunneling from quantum chemistry to quantum annealing

    Science.gov (United States)

    Mazzola, Guglielmo; Smelyanskiy, Vadim N.; Troyer, Matthias

    2017-10-01

    Quantum tunneling is ubiquitous across different fields, from quantum chemical reactions and magnetic materials to quantum simulators and quantum computers. While simulating the real-time quantum dynamics of tunneling is infeasible for high-dimensional systems, quantum tunneling also shows up in quantum Monte Carlo (QMC) simulations, which aim to simulate quantum statistics with resources growing only polynomially with the system size. Here we extend the recent results obtained for quantum spin models [Phys. Rev. Lett. 117, 180402 (2016), 10.1103/PhysRevLett.117.180402], and we study continuous-variable models for proton transfer reactions. We demonstrate that QMC simulations efficiently recover the scaling of ground-state tunneling rates due to the existence of an instanton path, which always connects the reactant state with the product. We discuss the implications of our results in the context of quantum chemical reactions and quantum annealing, where quantum tunneling is expected to be a valuable resource for solving combinatorial optimization problems.

  7. Implantation annealing in GaAs by incoherent light

    International Nuclear Information System (INIS)

    Davies, D.E.; Ryan, T.G.; Soda, K.J.; Comer, J.J.

    1983-01-01

    Implanted GaAs has been successfully activated through concentrating the output of quartz halogen lamps to anneal in times of the order of 1 sec. The resulting layers are not restricted by the reduced mobilities and thermal instabilities of laser annealed GaAs. Better activation can be obtained than with furnace annealing but this generally requires maximum temperatures >= 1050degC. (author)

  8. RESIDENCE TIMES OF PARTICLES IN DIFFUSIVE PROTOPLANETARY DISK ENVIRONMENTS. II. RADIAL MOTIONS AND APPLICATIONS TO DUST ANNEALING

    International Nuclear Information System (INIS)

    Ciesla, F. J.

    2011-01-01

    The origin of crystalline grains in comets and the outer regions of protoplanetary disks remains a mystery. It has been suggested that such grains form via annealing of amorphous precursors in the hot, inner region of a protoplanetary disk, where the temperatures needed for such transformations were found, and were then transported outward by some dynamical means. Here we develop a means of tracking the paths that dust grains would have taken through a diffusive protoplanetary disk and examine the types and ranges of environments that particles would have seen over a 10 6 yr time period in the dynamic disk. We then combine this model with three annealing laws to examine how the dynamic evolution of amorphous grains would have led to their physical restructuring and their delivery to various regions of the disk. It is found that 'sibling particles' - those particles that reside at the same location at a given period of time-take a wide range of unique and independent paths through the disk to arrive there. While high temperatures can persist in the disk for very long time periods, we find that those grains that are delivered to the cold outer regions of the disk are largely annealed in the first few x10 5 yr of disk history. This suggests that the crystallinity of grains in the outer disk would be determined early and remain unchanged for much of disk history, in agreement with recent astronomical observations.

  9. Temperature distribution study in flash-annealed amorphous ribbons

    International Nuclear Information System (INIS)

    Moron, C.; Garcia, A.; Carracedo, M.T.

    2003-01-01

    Negative magnetrostrictive amorphous ribbons have been locally current annealed with currents from 1 to 8 A and annealing times from 14 ms to 200 s. In order to obtain information about the sample temperature during flash or current annealing, a study of the temperature dispersion during annealing in amorphous ribbons was made. The local temperature variation was obtained by measuring the local intensity of the infrared emission of the sample with a CCD liquid nitrogen cooled camera. A distribution of local temperature has been found in spite of the small dimension of the sample

  10. Visible light emission from silicon implanted and annealed SiO2layers

    International Nuclear Information System (INIS)

    Ghislotti, G.; Nielsen, B.; Asoka-Kumar, P.; Lynn, K.G.; Di Mauro, L.F.; Bottani, C.E.; Corni, F.; Tonini, R.; Ottaviani, G.P.

    1997-01-01

    Silicon implanted and annealed SiO 2 layers are studied using photoluminescence (PL) and positron annihilation spectroscopy (PAS). Two PL emission bands are observed. A band centered at 560 nm is present in as-implanted samples and it is still observed after 1,000 C annealing. The emission time is fast. A second band centered at 780 nm is detected after 1,000 C annealing. The intensity of the 780 nm band further increased when hydrogen annealing was performed. The emission time is long (1 micros to 0.2 ms). PAS results show that defects produced by implantation anneal at 600 C. Based on the annealing behavior and on the emission times, the origin of the two bands is discussed

  11. Sintering and annealing effects on undoped yttria transparent ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Letue, Laetitia; Petit, Johan, E-mail: johan.petit@onera.fr; Ritti, Marie-Hélène; Lalanne, Sylvie; Landais, Stéphane

    2017-06-15

    Transparent yttrium oxide (Y{sub 2}O{sub 3}) ceramics were processed by several densifications steps without any doping species. The green bodies were obtained by the aqueous way and sintered at high temperature under vacuum and then under high pressure. We studied the effects of different sintering cycles and air annealing at different steps of the process on the density and the grain growth. We also focused on the reaction between yttria ceramics and BN-coated graphite crucible which occurs during HIP. We noted that a low heating rate and two annealing steps are necessary to improve our samples’ transparency. - Highlights: • The quality of transparent ceramics is compared with the tested process parameters. • Air annealing is critical when using a carbon environment in the process. • Intra-granular pores, and so the final transparency, are directly linked to the sintering heating rates.

  12. Simulated annealing (SA to vehicle routing problems with soft time windows

    Directory of Open Access Journals (Sweden)

    Suphan Sodsoon

    2014-12-01

    Full Text Available The researcher has applied and develops the meta-heuristics method to solve Vehicle Routing Problems with Soft Time Windows (VRPSTW. For this case there was only one depot, multi customers which each generally sparse either or demand was different though perceived number of demand and specific period of time to receive them. The Operation Research was representative combinatorial optimization problems and is known to be NP-hard. In this research algorithm, use Simulated Annealing (SA to determine the optimum solutions which rapidly time solving. After developed the algorithms, apply them to examine the factors and the optimum extended time windows and test these factors with vehicle problem routing under specific time windows by Solomon in OR-Library in case of maximum 25 customers. Meanwhile, 6 problems are including of C101, C102, R101, R102, RC101 and RC102 respectively. The result shows the optimum extended time windows at level of 50%. At last, after comparison these answers with the case of vehicle problem routing under specific time windows and flexible time windows, found that percentage errors on number of vehicles approximately by -28.57% and percentage errors on distances approximately by -28.57% which this algorithm spent average processing time on 45.5 sec/problems.

  13. Global warming: Temperature estimation in annealers

    Directory of Open Access Journals (Sweden)

    Jack Raymond

    2016-11-01

    Full Text Available Sampling from a Boltzmann distribution is NP-hard and so requires heuristic approaches. Quantum annealing is one promising candidate. The failure of annealing dynamics to equilibrate on practical time scales is a well understood limitation, but does not always prevent a heuristically useful distribution from being generated. In this paper we evaluate several methods for determining a useful operational temperature range for annealers. We show that, even where distributions deviate from the Boltzmann distribution due to ergodicity breaking, these estimates can be useful. We introduce the concepts of local and global temperatures that are captured by different estimation methods. We argue that for practical application it often makes sense to analyze annealers that are subject to post-processing in order to isolate the macroscopic distribution deviations that are a practical barrier to their application.

  14. Ion-beam mixing and thermal annealing of Al--Nb and Al--Ta thin films

    International Nuclear Information System (INIS)

    Rai, A.K.; Bhattacharya, R.S.; Mendiratta, M.G.; Subramanian, P.R.; Dimiduk, D.M.

    1988-01-01

    Ion-beam mixing and thermal annealing of thin, alternating layers of Al and Nb, as well as Al and Ta, were investigated by selected area diffraction and Rutherford backscattering. The individual layer thicknesses were adjusted to obtain the overall compositions as Al 3 Nb and Al 3 Ta. The films were ion mixed with 1 MeV Au + ions at a dose of 1 x 10 16 ions cm/sup -2/ . Uniform mixing and amorphization were achieved for both Al--Nb and Al--Ta systems. Equilibrium crystalline Al 3 Nb and Al 3 Ta phases were formed after annealing of ion mixed amorphous films at 400 0 C for 6 h. Unmixed films, however, remained unreacted at 400 0 C for 1 h. Partial reaction was observed in the unmixed film of Al--Nb at 400 0 C for 6 h. After annealing at 500 0 C for 1 h, a complete reaction and formation of Al 3 Nb and Al 3 Ta phases in the respective films were observed. The influence of thermodynamics on the phase formation by ion mixing and thermal annealing is discussed

  15. Stored energy and annealing behavior of heavily deformed aluminium

    DEFF Research Database (Denmark)

    Kamikawa, Naoya; Huang, Xiaoxu; Kondo, Yuka

    2012-01-01

    It has been demonstrated in previous work that a two-step annealing treatment, including a low-temperature, long-time annealing and a subsequent high-temperature annealing, is a promising route to control the microstructure of a heavily deformed metal. In the present study, structural parameters...... are quantified such as boundary spacing, misorientation angle and dislocation density for 99.99% aluminium deformed by accumulative roll-bonding to a strain of 4.8. Two different annealing processes have been applied; (i) one-step annealing for 0.5 h at 100-400°C and (ii) two-step annealing for 6 h at 175°C...... followed by 0.5 h annealing at 200-600°C, where the former treatment leads to discontinuous recrystallization and the latter to uniform structural coarsening. This behavior has been analyzed in terms of the relative change during annealing of energy stored as elastic energy in the dislocation structure...

  16. Effects of a modular two-step ozone-water and annealing process on silicon carbide graphene

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Matthew J., E-mail: matthew.webb@cantab.net; Lundstedt, Anna; Grennberg, Helena [Department of Chemistry—BMC, Uppsala University, Box 576, SE-751 23 Uppsala (Sweden); Polley, Craig; Niu, Yuran; Zakharov, Alexei A.; Balasubramanian, Thiagarajan [MAX IV Laboratory, Lund University, 22100 Lund (Sweden); Dirscherl, Kai [DFM—Danish Fundamental Metrology, Matematiktorvet 307, DK-2800 Lyngby (Denmark); Burwell, Gregory; Guy, Owen J. [College of Engineering, Faraday Tower, Singleton Park, Swansea University, Swansea SA2 8PP (United Kingdom); Palmgren, Pål [VG Scienta Scientific AB, Box 15120, Vallongatan 1, SE-750 15 Uppsala (Sweden); Yakimova, Rositsa [Department of Physics, Chemistry, and Biology, Linköping University, SE-581 83 Linköping (Sweden)

    2014-08-25

    By combining ozone and water, the effect of exposing epitaxial graphene on silicon carbide to an aggressive wet-chemical process has been evaluated after high temperature annealing in ultra high vacuum. The decomposition of ozone in water produces a number of oxidizing species, however, despite long exposure times to the aqueous-ozone environment, no graphene oxide was observed after the two-step process. The systems were comprehensively characterized before and after processing using Raman spectroscopy, core level photoemission spectroscopy, and angle resolved photoemission spectroscopy together with low energy electron diffraction, low energy electron microscopy, and atomic force microscopy. In spite of the chemical potential of the aqueous-ozone reaction environment, the graphene domains were largely unaffected raising the prospect of employing such simple chemical and annealing protocols to clean or prepare epitaxial graphene surfaces.

  17. High-Temperature-Short-Time Annealing Process for High-Performance Large-Area Perovskite Solar Cells.

    Science.gov (United States)

    Kim, Minjin; Kim, Gi-Hwan; Oh, Kyoung Suk; Jo, Yimhyun; Yoon, Hyun; Kim, Ka-Hyun; Lee, Heon; Kim, Jin Young; Kim, Dong Suk

    2017-06-27

    Organic-inorganic hybrid metal halide perovskite solar cells (PSCs) are attracting tremendous research interest due to their high solar-to-electric power conversion efficiency with a high possibility of cost-effective fabrication and certified power conversion efficiency now exceeding 22%. Although many effective methods for their application have been developed over the past decade, their practical transition to large-size devices has been restricted by difficulties in achieving high performance. Here we report on the development of a simple and cost-effective production method with high-temperature and short-time annealing processing to obtain uniform, smooth, and large-size grain domains of perovskite films over large areas. With high-temperature short-time annealing at 400 °C for 4 s, the perovskite film with an average domain size of 1 μm was obtained, which resulted in fast solvent evaporation. Solar cells fabricated using this processing technique had a maximum power conversion efficiency exceeding 20% over a 0.1 cm 2 active area and 18% over a 1 cm 2 active area. We believe our approach will enable the realization of highly efficient large-area PCSs for practical development with a very simple and short-time procedure. This simple method should lead the field toward the fabrication of uniform large-scale perovskite films, which are necessary for the production of high-efficiency solar cells that may also be applicable to several other material systems for more widespread practical deployment.

  18. Electrical properties and annealing kinetics study of laser-annealed ion-implanted silicon

    International Nuclear Information System (INIS)

    Wang, K.L.; Liu, Y.S.; Kirkpatrick, C.G.; Possin, G.E.

    1979-01-01

    This paper describes measurements of electrical properties and the regrowth behavior of ion-implanted silicon annealed with an 80-ns (FWHM) laser pulse at 1.06 μm. The experimental results include: (1) a determination of threshold energy density required for melting using a transient optical reflectivity technique, (2) measurements of dopant distribution using Rutherford backscattering spectroscopy, (3) characterization of electrical properties by measuring reverse leakage current densities of laser-annealed and thermal-annealed mesa diodes, (4) determination of annealed junction depth using an electron-beam-induced-current technique, and (5) a deep-level-transient spectroscopic study of residual defects. In particular, by measuring these properties of a diode annealed at a condition near the threshold energy density for liquid phase epitaxial regrowth, we have found certain correlations among these various annealing behaviors and electrical properties of laser-annealed ion-implanted silicon diodes

  19. Study of the reduction in detection limits of track detectors used for {sup 10}B(n,α){sup 7}Li reaction rate measure through annealing and chemical etching experiments; Estudo da reducao nos limites de deteccao de detectores de tracos utilizados na medida de taxa de reacao {sup 10}B(n, α){sup 7}Li atraves de experimentos de annealing e ataque quimico

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcellos, Herminiane L.; Smilgys, Barbara; Guedes, Sandro, E-mail: hluizav@ifi.unicamp.br [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Instituto de Fisica Gleb Wataghin; Castro, Vinicius A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Engenharia Nuclear

    2013-08-15

    The Boron Neutron Capture Therapy (BNCT) is an experimental radiotherapy for cancer treatment. It is based on {sup 10}B(n, α){sup 7}Li reaction, which can be measured by track detectors capable of recording events that strike them. With this recording, it is possible to determine the number of alpha particles and recoiling Lithium-7 nucleus, reaction products, and from this information, which amount of radiation dose a patient is exposed to. In this work, PADC detectors were characterized, irradiated at the IEA-R1 IPEN/CNEN reactor to assess the contribution of the{sup 10}B(n, α){sup 7}Li reaction and protons from fast neutron scattering with the elements that compounds the tissue. With the aim of reducing the proton background, the detectors were subjected to heating experiments at 80°C for periods in the range 0-100 hours. This was done in order to restore partially modified structure of the detector, causing a reduction in the size and density of tracks. This effect is known as annealing. For the visualization of tracks at microscope, detectors were made three chemical attacks with sodium hydroxide (NaOH) for 30, 60 and 90 minutes at 70°C. It was observed a reduction in the track density achieving a plateau heating time of 50 hours. For detectors that have not undergone annealing and were etched with another etchant, PEW solution, a reduction of 87% in track density was obtained. (author)

  20. Selective molecular annealing: in situ small angle X-ray scattering study of microwave-assisted annealing of block copolymers.

    Science.gov (United States)

    Toolan, Daniel T W; Adlington, Kevin; Isakova, Anna; Kalamiotis, Alexis; Mokarian-Tabari, Parvaneh; Dimitrakis, Georgios; Dodds, Christopher; Arnold, Thomas; Terrill, Nick J; Bras, Wim; Hermida Merino, Daniel; Topham, Paul D; Irvine, Derek J; Howse, Jonathan R

    2017-08-09

    Microwave annealing has emerged as an alternative to traditional thermal annealing approaches for optimising block copolymer self-assembly. A novel sample environment enabling small angle X-ray scattering to be performed in situ during microwave annealing is demonstrated, which has enabled, for the first time, the direct study of the effects of microwave annealing upon the self-assembly behavior of a model, commercial triblock copolymer system [polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene]. Results show that the block copolymer is a poor microwave absorber, resulting in no change in the block copolymer morphology upon application of microwave energy. The block copolymer species may only indirectly interact with the microwave energy when a small molecule microwave-interactive species [diethylene glycol dibenzoate (DEGDB)] is incorporated directly into the polymer matrix. Then significant morphological development is observed at DEGDB loadings ≥6 wt%. Through spatial localisation of the microwave-interactive species, we demonstrate targeted annealing of specific regions of a multi-component system, opening routes for the development of "smart" manufacturing methodologies.

  1. Tunable metal-insulator transitions in bilayer graphene by thermal annealing

    OpenAIRE

    Kalon, Gopinadhan; Shin, Young Jun; Yang, Hyunsoo

    2012-01-01

    Tunable and highly reproducible metal-insulator transitions have been observed in bilayer graphene upon thermal annealing at 400 K under high vacuum conditions. Before annealing, the sample is metallic in the whole temperature regime of study. Upon annealing, the conductivity changes from metallic to that of an insulator and the transition temperature is a function of annealing time. The pristine metallic state can be reinstated by exposing to air thereby inducing changes in the electronic pr...

  2. Comparison between thermal annealing and ion mixing of multilayered Ni-W films on Si. II

    International Nuclear Information System (INIS)

    Pai, C.S.; Lau, S.S.; Poker, D.B.; Hung, L.S.

    1985-01-01

    The reactions between bilayered Ni/W films and Si substrates induced by thermal annealing and ion mixing were investigated and compared. Samples were prepared by electron-beam sequential deposition of Ni and W onto the Si substrates and following by either furnace annealing (approx. 200--900 0 C) or ion mixing (approx. 2 x 10 15 -- 4 x 10 16 86 Kr + ions/cm 2 ). The reactions were analyzed by Rutherford backscattering and x-ray diffraction (Read camera). Thermal annealing of both W/Ni/Si and Ni/W/Si samples led to the formation of Ni silicide next to the Si substrate and W silicide on the sample surface (layer reversal between Ni and W in the Ni/W/Si case). Ion mixing of W/Ni/Si samples led to the formation of Ni silicide with a thin layer of Ni-W-Si mixture located at the sample surface. For Ni/W/Si samples a ternary amorphous mixture of Ni-W-Si was obtained with ion mixing. These reactions were rationalized in terms of the mobilities of various atoms and the intermixings between layers

  3. Structural, electrical and optical studies of SILAR deposited cadmium oxide thin films: Annealing effect

    International Nuclear Information System (INIS)

    Salunkhe, R.R.; Dhawale, D.S.; Gujar, T.P.; Lokhande, C.D.

    2009-01-01

    Successive ionic layer adsorption and reaction (SILAR) method has been successfully employed for the deposition of cadmium oxide (CdO) thin films. The films were annealed at 623 K for 2 h in an air and changes in the structural, electrical and optical properties were studied. From the X-ray diffraction patterns, it was found that after annealing, H 2 O vapors from as-deposited Cd(O 2 ) 0.88 (OH) 0.24 were removed and pure cubic cadmium oxide was obtained. The as-deposited film consists of nanocrystalline grains of average diameter about 20-30 nm with uniform coverage of the substrate surface, whereas for the annealed film randomly oriented morphology with slight increase in the crystallite size has been observed. The electrical resistivity showed the semiconducting nature with room temperature electrical resistivity decreased from 10 -2 to 10 -3 Ω cm after annealing. The decrease in the band gap energy from 3.3 to 2.7 eV was observed after the annealing

  4. Scalable effective-temperature reduction for quantum annealers via nested quantum annealing correction

    Science.gov (United States)

    Vinci, Walter; Lidar, Daniel A.

    2018-02-01

    Nested quantum annealing correction (NQAC) is an error-correcting scheme for quantum annealing that allows for the encoding of a logical qubit into an arbitrarily large number of physical qubits. The encoding replaces each logical qubit by a complete graph of degree C . The nesting level C represents the distance of the error-correcting code and controls the amount of protection against thermal and control errors. Theoretical mean-field analyses and empirical data obtained with a D-Wave Two quantum annealer (supporting up to 512 qubits) showed that NQAC has the potential to achieve a scalable effective-temperature reduction, Teff˜C-η , with 0 temperature of a quantum annealer. Such effective-temperature reduction is relevant for machine-learning applications. Since we demonstrate that NQAC achieves error correction via a reduction of the effective-temperature of the quantum annealing device, our results address the problem of the "temperature scaling law for quantum annealers," which requires the temperature of quantum annealers to be reduced as problems of larger sizes are attempted to be solved.

  5. Annealing effect on restoration of irradiation steel properties

    International Nuclear Information System (INIS)

    Vishkarev, O.M.; Kolesova, T.N.; Myasnikova, K.P.; Pecherin, A.M.; Shamardin, V.K.

    1986-01-01

    The effect of temperature and annealing time on the restoration of properties of the 15Kh2NMFAA and 15Kh2MFA steels after irradiation at 285 deg with the fluence of 6x10 23 neutr/m 2 (E>0.5 MeV) is studied. Microhardness (H μ ) restoration in the irradiated 15Kh2NMFAA steel is shown to start from 350 deg C annealing temperature. The complete microhardness restoration is observed at the annealing temperature of 500 deg C for 10 hours

  6. Cascade annealing: an overview

    International Nuclear Information System (INIS)

    Doran, D.G.; Schiffgens, J.O.

    1976-04-01

    Concepts and an overview of radiation displacement damage modeling and annealing kinetics are presented. Short-term annealing methodology is described and results of annealing simulations performed on damage cascades generated using the Marlowe and Cascade programs are included. Observations concerning the inconsistencies and inadequacies of current methods are presented along with simulation of high energy cascades and simulation of longer-term annealing

  7. An electrochemical analysis of AZ91 Mg alloy processed by plasma electrolytic oxidation followed by static annealing

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Y.G. [School of Materials Science and Engineering, Yeungnam University, 214-1 Dae-Dong, Gyeongsan 712-749, Gyeongbuk (Korea, Republic of); Lee, K.M.; Lee, B.U. [Department of Metallurgy and Materials Engineering, Hanyang University, Ansan 425-791 (Korea, Republic of); Shin, D.H., E-mail: dhshin@hanyang.ac.kr [Department of Metallurgy and Materials Engineering, Hanyang University, Ansan 425-791 (Korea, Republic of)

    2011-06-15

    Research highlights: > The amount of MgO in the oxide film increased with increasing annealing temperature. > The dehydration reaction resulted in the formation of micro-cracks in the oxide film. > Electrochemical response of the PEO-treated sample annealed at 150 deg. C was improved. - Abstract: In this study, the effect of subsequent annealing on the electrochemical response of AZ91 Mg alloy coated via plasma electrolytic oxidation (PEO) was investigated. PEO coating was carried out on the Mg alloy under AC condition in an alkaline silicate electrolyte, and the PEO-coated samples underwent several subsequent annealing treatments at three different temperatures of 100, 150, and 200 deg. C. The surface morphologies of the coating layers were observed via a scanning electron microscope (SEM) and their constituent compounds were characterized by qualitative observation based on X-ray photoelectron spectroscopy (XPS). In addition, the corrosion protection properties of the PEO-coated sample were examined by electrochemical impedance spectroscopy (EIS) in a 3.5 wt% NaCl solution with a focus on exploring the effect of subsequent annealing on the electrochemical response in a quantitative manner. SEM and XPS observations evidenced that the subsequent annealing at temperatures higher than 150 deg. C resulted in significant morphological changes due to the dehydration reaction of Mg(OH){sub 2} to form MgO. Thus, it was found that the sample annealed at 150 deg. C exhibited a better corrosion resistance than the other samples, which were analyzed by taking an equivalent circuit model into account.

  8. Cyclical Annealing Technique To Enhance Reliability of Amorphous Metal Oxide Thin Film Transistors.

    Science.gov (United States)

    Chen, Hong-Chih; Chang, Ting-Chang; Lai, Wei-Chih; Chen, Guan-Fu; Chen, Bo-Wei; Hung, Yu-Ju; Chang, Kuo-Jui; Cheng, Kai-Chung; Huang, Chen-Shuo; Chen, Kuo-Kuang; Lu, Hsueh-Hsing; Lin, Yu-Hsin

    2018-02-26

    This study introduces a cyclical annealing technique that enhances the reliability of amorphous indium-gallium-zinc-oxide (a-IGZO) via-type structure thin film transistors (TFTs). By utilizing this treatment, negative gate-bias illumination stress (NBIS)-induced instabilities can be effectively alleviated. The cyclical annealing provides several cooling steps, which are exothermic processes that can form stronger ionic bonds. An additional advantage is that the total annealing time is much shorter than when using conventional long-term annealing. With the use of cyclical annealing, the reliability of the a-IGZO can be effectively optimized, and the shorter process time can increase fabrication efficiency.

  9. Unified model of damage annealing in CMOS, from freeze-in to transient annealing

    International Nuclear Information System (INIS)

    Sander, H.H.; Gregory, B.L.

    Results of an experimental study at 76 0 K, are presented showing that radiation-produced holes in SiO 2 are immobile at this temperature. If an electric field is present in the SiO 2 during low temperature (76 0 K) irradiation to sweep out the mobile electrons, the holes will virtually all be trapped where created and produce a uniform positive charge density in the oxide. These results are the basis for concluding that if a complimentary p,n metal-oxide semiconductor (CMOS) device is irradiated for sufficient time at 76 0 K to build-in an appreciable field, further irradiation with gate bias removed will produce very little additional change in V/sub th/, since the field in the oxide tends to keep all generated electrons in the oxide where they recombine with trapped holes. Hence the hole trapping rate = the hole annihilation rate. The room-temperature annealing following a pulsed gamma exposure occurs in two regimes. The first recovery of V/sub th/ occurs prior to 10 -4 seconds. The magnitude of this very early-time recovery, at room temperature, is oxide-dependent, and oxide process dependent. The rate-of-annealing is what is truly different between a rad-hard and a rad-soft device, since annealing in the hardest devices occurs very quickly at room temperature. (U.S.)

  10. Effect of annealing temperatures on the electrical conductivity and dielectric properties of Ni1.5Fe1.5O4 spinel ferrite prepared by chemical reaction at different pH values

    Science.gov (United States)

    Aneesh Kumar, K. S.; Bhowmik, R. N.

    2017-12-01

    The electrical conductivity and dielectric properties of Ni1.5Fe1.5O4 ferrite has been controlled by varying the annealing temperature of the chemical routed samples. The frequency activated conductivity obeyed Jonscher’s power law and universal scaling suggested semiconductor nature. An unusual metal like state has been revealed in the measurement temperature scale in between two semiconductor states with different activation energy. The metal like state has been affected by thermal annealing of the material. The analysis of electrical impedance and modulus spectra has confirmed non-Debye dielectric relaxation with contributions from grains and grain boundaries. The dielectric relaxation process is thermally activated in terms of measurement temperature and annealing temperature of the samples. The hole hopping process, due to presence of Ni3+ ions in the present Ni rich ferrite, played a significant role in determining the thermal activated conduction mechanism. This work has successfully applied the technique of a combined variation of annealing temperature and pH value during chemical reaction for tuning electrical parameters in a wide range; for example dc limit of conductivity ~10-4-10-12 S cm-1, and unusually high activation energy ~0.17-1.36 eV.

  11. The Effect of Sports and Physical Activity on Elderly Reaction Time and Response Time

    Directory of Open Access Journals (Sweden)

    Abdolrahman Khezri

    2014-07-01

    Full Text Available Objectives: Physical activities ameliorate elderly motor and cognitive performance. The aim of this research is to study the effect of sport and physical activity on elderly reaction time and response time. Methods & Materials: The research method is causal-comparative and its statistical population consists of 60 active and non-active old males over 60 years residing at Mahabad city. Reaction time was measured by reaction timer apparatus, made in Takei Company (YB1000 model. Response time was measured via Nelson’s Choice- Response Movement Test. At first, reaction time and then response time was measured. For data analysis, descriptive statistic, K-S Test and One Sample T Test were used Results K-S Test show that research data was parametric. According to the results of this research, physical activity affected reaction time and response time. Results: of T test show that reaction time (P=0.000 and response time (P=0.000 of active group was statistically shorter than non- active group. Conclusion: The result of current study demonstrate that sport and physical activity, decrease reaction and response time via psychomotor and physiological positive changes.

  12. Extrapolation of zircon fission-track annealing models

    International Nuclear Information System (INIS)

    Palissari, R.; Guedes, S.; Curvo, E.A.C.; Moreira, P.A.F.P.; Tello, C.A.; Hadler, J.C.

    2013-01-01

    One of the purposes of this study is to give further constraints on the temperature range of the zircon partial annealing zone over a geological time scale using data from borehole zircon samples, which have experienced stable temperatures for ∼1 Ma. In this way, the extrapolation problem is explicitly addressed by fitting the zircon annealing models with geological timescale data. Several empirical model formulations have been proposed to perform these calibrations and have been compared in this work. The basic form proposed for annealing models is the Arrhenius-type model. There are other annealing models, that are based on the same general formulation. These empirical model equations have been preferred due to the great number of phenomena from track formation to chemical etching that are not well understood. However, there are two other models, which try to establish a direct correlation between their parameters and the related phenomena. To compare the response of the different annealing models, thermal indexes, such as closure temperature, total annealing temperature and the partial annealing zone, have been calculated and compared with field evidence. After comparing the different models, it was concluded that the fanning curvilinear models yield the best agreement between predicted index temperatures and field evidence. - Highlights: ► Geological data were used along with lab data for improving model extrapolation. ► Index temperatures were simulated for testing model extrapolation. ► Curvilinear Arrhenius models produced better geological temperature predictions

  13. Principal and secondary luminescence lifetime components in annealed natural quartz

    International Nuclear Information System (INIS)

    Chithambo, M.L.; Ogundare, F.O.; Feathers, J.

    2008-01-01

    Time-resolved luminescence spectra from quartz can be separated into components with distinct principal and secondary lifetimes depending on certain combinations of annealing and measurement temperature. The influence of annealing on properties of the lifetimes related to irradiation dose and temperature of measurement has been investigated in sedimentary quartz annealed at various temperatures up to 900 deg. C. Time-resolved luminescence for use in the analysis was pulse stimulated from samples at 470 nm between 20 and 200 deg. C. Luminescence lifetimes decrease with measurement temperature due to increasing thermal effect on the associated luminescence with an activation energy of thermal quenching equal to 0.68±0.01eV for the secondary lifetime but only qualitatively so for the principal lifetime component. Concerning the influence of annealing temperature, luminescence lifetimes measured at 20 deg. C are constant at about 33μs for annealing temperatures up to 600 0 C but decrease to about 29μs when the annealing temperature is increased to 900 deg. C. In addition, it was found that lifetime components in samples annealed at 800 deg. C are independent of radiation dose in the range 85-1340 Gy investigated. The dependence of lifetimes on both the annealing temperature and magnitude of radiation dose is described as being due to the increasing importance of a particular recombination centre in the luminescence emission process as a result of dynamic hole transfer between non-radiative and radiative luminescence centres

  14. Influence of alloying and secondary annealing on anneal hardening ...

    Indian Academy of Sciences (India)

    Unknown

    Influence of alloying and secondary annealing on anneal hardening effect at sintered copper alloys. SVETLANA NESTOROVIC. Technical Faculty Bor, University of Belgrade, Bor, Yugoslavia. MS received 11 February 2004; revised 29 October 2004. Abstract. This paper reports results of investigation carried out on sintered ...

  15. Preparation and Thermal Characterization of Annealed Gold Coated Porous Silicon

    Directory of Open Access Journals (Sweden)

    Afarin Bahrami

    2012-01-01

    Full Text Available Porous silicon (PSi layers were formed on a p-type Si wafer. Six samples were anodised electrically with a 30 mA/cm2 fixed current density for different etching times. The samples were coated with a 50–60 nm gold layer and annealed at different temperatures under Ar flow. The morphology of the layers, before and after annealing, formed by this method was investigated by scanning electron microscopy (SEM. Photoacoustic spectroscopy (PAS measurements were carried out to measure the thermal diffusivity (TD of the PSi and Au/PSi samples. For the Au/PSi samples, the thermal diffusivity was measured before and after annealing to study the effect of annealing. Also to study the aging effect, a comparison was made between freshly annealed samples and samples 30 days after annealing.

  16. Effect of thermal annealing on the structure and magnetism of Fe-doped ZnO nanocrystals synthesized by solid state reaction

    Science.gov (United States)

    Wang, Dong; Chen, Z. Q.; Wang, D. D.; Gong, J.; Cao, C. Y.; Tang, Z.; Huang, L. R.

    2010-11-01

    High purity Fe 2O 3/ZnO nanocomposites were annealed in air at different temperatures between 100 and 1200 °C to get Fe-doped ZnO nanocrystals. The structure and grain size of the Fe 2O 3/ZnO nanocomposites were investigated by X-ray diffraction 2θ scans. Annealing induces an increase of the grain size from 25 to 195 nm and appearance of franklinite phase of ZnFe 2O 4. Positron annihilation measurements reveal large number of vacancy defects in the interface region of the Fe 2O 3/ZnO nanocomposites, and they are gradually recovered with increasing annealing temperature. After annealing at temperatures higher than 1000 °C, the number of vacancies decreases to the lower detection limit of positrons. Room temperature ferromagnetism can be observed in Fe-doped ZnO nanocrystals using physical properties measurement system. The ferromagnetism remains after annealing up to 1000 °C, suggesting that it is not related with the interfacial defects.

  17. Effect of thermal annealing on the structure and magnetism of Fe-doped ZnO nanocrystals synthesized by solid state reaction

    International Nuclear Information System (INIS)

    Wang Dong; Chen, Z.Q.; Wang, D.D.; Gong, J.; Cao, C.Y.; Tang, Z.; Huang, L.R.

    2010-01-01

    High purity Fe 2 O 3 /ZnO nanocomposites were annealed in air at different temperatures between 100 and 1200 o C to get Fe-doped ZnO nanocrystals. The structure and grain size of the Fe 2 O 3 /ZnO nanocomposites were investigated by X-ray diffraction 2θ scans. Annealing induces an increase of the grain size from 25 to 195 nm and appearance of franklinite phase of ZnFe 2 O 4 . Positron annihilation measurements reveal large number of vacancy defects in the interface region of the Fe 2 O 3 /ZnO nanocomposites, and they are gradually recovered with increasing annealing temperature. After annealing at temperatures higher than 1000 o C, the number of vacancies decreases to the lower detection limit of positrons. Room temperature ferromagnetism can be observed in Fe-doped ZnO nanocrystals using physical properties measurement system. The ferromagnetism remains after annealing up to 1000 o C, suggesting that it is not related with the interfacial defects.

  18. Facile Synthesis of Calcium Borate Nanoparticles and the Annealing Effect on Their Structure and Size

    Directory of Open Access Journals (Sweden)

    Manizheh Navasery

    2012-11-01

    Full Text Available Calcium borate nanoparticles have been synthesized by a thermal treatment method via facile co-precipitation. Differences of annealing temperature and annealing time and their effects on crystal structure, particle size, size distribution and thermal stability of nanoparticles were investigated. The formation of calcium borate compound was characterized by X-ray diffraction (XRD and Fourier Transform Infrared spectroscopy (FTIR, Transmission electron microscopy (TEM, and Thermogravimetry (TGA. The XRD patterns revealed that the co-precipitated samples annealed at 700 °C for 3 h annealing time formed an amorphous structure and the transformation into a crystalline structure only occurred after 5 h annealing time. It was found that the samples annealed at 900 °C are mostly metaborate (CaB2O4 nanoparticles and tetraborate (CaB4O7 nanoparticles only observed at 970 °C, which was confirmed by FTIR. The TEM images indicated that with increasing the annealing time and temperature, the average particle size increases. TGA analysis confirmed the thermal stability of the annealed samples at higher temperatures.

  19. Time effects in the thermal annealing of Fe/V multilayers

    CERN Document Server

    Borges, J F M

    2003-01-01

    We report a study on the structural and magnetic properties of iron-vanadium thin films grown in multilayer form and mixed by thermal treatment. The multilayer samples were annealed at 610 deg. C for times ranging from 10 to 540 min. The samples were structurally characterized by means of x-ray diffraction (XRD) and by x-ray absorption spectroscopy (XAS). The magnetic characterization was carried out with a conventional alternating gradient magnetometer (AGM) and by conversion electron Moessbauer spectroscopy (CEMS). The XRD result for the as-deposited multilayer shows a high degree of crystallinity while the CEMS result suggests an abrupt interface, since no significant contribution from vanadium in iron is observed. After the thermal treatment, the results from XRD show a phase transformation of the disordered body-centred-cubic structure (alpha-phase) into a tetragonal structure (sigma-phase) and a subsequent return to the alpha-phase. This alpha-sigma-alpha oscillation is not reported in the literature av...

  20. Liquid nitrogen enhancement of partially annealed fission tracks in glass

    International Nuclear Information System (INIS)

    Pilione, L.J.; Gold, D.P.

    1976-01-01

    It is known that the number density of fission tracks in solids is reduced if the sample is heated before chemical etching, and the effect of annealing must be allowed for before an age can be assigned to the sample. The extent of annealing can be determined by measuring the reduction of track parameters (diameter and/or length) and comparison with unannealed tracks. Correct ages can be obtained by careful calibration studies of track density reduction against track diameter or length reduction at different annealing temperatures and times. For crystallised minerals, however, the resulting correction techniques are not generally valid. In the experimental work described glass samples were partially annealed and then immersed in liquid N 2 for various periods, and it was shown that the properties of the glass and the track parameters could be altered so as to observe tracks that would normally be erased by annealing. The results of track density measurements against liquid N 2 immersion times are shown graphically. A gain of about 40% was achieved after 760 hours immersion time. The size of the tracks was not noticeably affected by the immersion. It was thought that thermal shock might be the cause of the track enhancement, but it was found that repeated immersion for about 2 hours did not lead to an increase in track density. Other studies suggest that the mechanism that erases the tracks through annealing may be partially reversed when the temperature of the sample is significantly lowered for a sufficient length of time. Further work is under way to find whether or not the process of enhancement is a reversal of the annealing process. Similar enhancement effects using liquid N 2 have been observed for d-particle tracks in polycarbonate detectors. (U.K.)

  1. Optimization using quantum mechanics: quantum annealing through adiabatic evolution

    International Nuclear Information System (INIS)

    Santoro, Giuseppe E; Tosatti, Erio

    2006-01-01

    We review here some recent work in the field of quantum annealing, alias adiabatic quantum computation. The idea of quantum annealing is to perform optimization by a quantum adiabatic evolution which tracks the ground state of a suitable time-dependent Hamiltonian, where 'ℎ' is slowly switched off. We illustrate several applications of quantum annealing strategies, starting from textbook toy-models-double-well potentials and other one-dimensional examples, with and without disorder. These examples display in a clear way the crucial differences between classical and quantum annealing. We then discuss applications of quantum annealing to challenging hard optimization problems, such as the random Ising model, the travelling salesman problem and Boolean satisfiability problems. The techniques used to implement quantum annealing are either deterministic Schroedinger's evolutions, for the toy models, or path-integral Monte Carlo and Green's function Monte Carlo approaches, for the hard optimization problems. The crucial role played by disorder and the associated non-trivial Landau-Zener tunnelling phenomena is discussed and emphasized. (topical review)

  2. Alloying and microstructural changes in platinum–titanium milled and annealed powders

    International Nuclear Information System (INIS)

    Maweja, Kasonde; Phasha, M.J.; Yamabe-Mitarai, Y.

    2012-01-01

    Graphical abstract: (a) SE-SEM micrographs of PtTi martensite formed in powder milled for short time annealed at 1500 °C and quenched in helium gas flow (b) BSE-SEM of structure formed after slow cooling. Highlights: ► A disordered metastable FCC Pt(Ti) solid solution was formed after longer milling period. ► HCP Ti crystals were first deformed and then the atoms were dissolved in strained FCC Pt lattices. ► Longer milling time suppressed the occurrence of martensitic transformation after annealing. ► Martensite phase was formed in products that went through a short milling time then annealed and quenched. ► The width of the martensite features formed was smaller at higher cooling rates. - Abstract: Equiatomic platinum–titanium powder mixtures were processed by high energy ball milling under argon atmosphere and sintered under vacuum. Evolution of the crystal structures and microstructures of the products formed were investigated by XRD and SEM techniques, respectively. The HCP crystals of Ti were first deformed and then a disordered metastable FCC Pt(Ti) solid solution was formed during milling due to semi-coherency of FCC lattices. A nanostructured Pt(Ti) product was formed after long milling time, which contained 44–47 at.% Ti and 53–56 at.% Pt. An ordered PtTi intermetallic was formed by annealing the metastable Pt(Ti) at temperature above 1300 °C. The crystal structure and microstructure of the TiPt phase depended on the milling time, annealing temperature and the cooling rate. The B19 PtTi plate martensite was formed after annealing at 1500 °C and quenching at a cooling rate of 23 °C/min to 200 °C/min for short time milled products. The width of martensite features was smaller at high cooling rate. In PtTi products milled for longer time, no martensitic transformation was observed on cooling the annealed samples. Small amounts of Pt 5 Ti 3 were formed in the powders milled for 16 h or more, followed by annealing at 1500 °C and furnace

  3. Annealing bounds to prevent further Charge Transfer Inefficiency increase of the Chandra X-ray CCDs

    Energy Technology Data Exchange (ETDEWEB)

    Monmeyran, Corentin, E-mail: comonmey@mit.edu [Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Patel, Neil S., E-mail: neilp@mit.edu [Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Bautz, Mark W., E-mail: mwb@space.mit.edu [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Grant, Catherine E., E-mail: cgrant@space.mit.edu [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Prigozhin, Gregory Y., E-mail: gyp@space.mit.edu [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Agarwal, Anuradha, E-mail: anu@mit.edu [Microphotonics Center, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Kimerling, Lionel C., E-mail: lckim@mit.edu [Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Microphotonics Center, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)

    2016-12-15

    After the front-illuminated CCDs on board the X-ray telescope Chandra were damaged by radiation after launch, it was decided to anneal them in an effort to remove the defects introduced by the irradiation. The annealing led to an unexpected increase of the Charge Transfer Inefficiency (CTI). The performance degradation is attributed to point defect interactions in the devices. Specifically, the annealing at 30 °C activated the diffusion of the main interstitial defect in the device, the carbon interstitial, which led to its association with a substitutional impurity, ultimately resulting in a stable and electrically active defect state. Because the formation reaction of this carbon interstitial and substitutional impurity associate is diffusion limited, we recommend a higher upper bound for the annealing temperature and duration of any future CCD anneals, that of −50 °C for one day or −60 °C for a week, to prevent further CTI increase.

  4. Dependence of high density nitrogen-vacancy center ensemble coherence on electron irradiation doses and annealing time

    Science.gov (United States)

    Zhang, C.; Yuan, H.; Zhang, N.; Xu, L. X.; Li, B.; Cheng, G. D.; Wang, Y.; Gui, Q.; Fang, J. C.

    2017-12-01

    Negatively charged nitrogen-vacancy (NV-) center ensembles in diamond have proved to have great potential for use in highly sensitive, small-package solid-state quantum sensors. One way to improve sensitivity is to produce a high-density NV- center ensemble on a large scale with a long coherence lifetime. In this work, the NV- center ensemble is prepared in type-Ib diamond using high energy electron irradiation and annealing, and the transverse relaxation time of the ensemble—T 2—was systematically investigated as a function of the irradiation electron dose and annealing time. Dynamical decoupling sequences were used to characterize T 2. To overcome the problem of low signal-to-noise ratio in T 2 measurement, a coupled strip lines waveguide was used to synchronously manipulate NV- centers along three directions to improve fluorescence signal contrast. Finally, NV- center ensembles with a high concentration of roughly 1015 mm-3 were manipulated within a ~10 µs coherence time. By applying a multi-coupled strip-lines waveguide to improve the effective volume of the diamond, a sub-femtotesla sensitivity for AC field magnetometry can be achieved. The long-coherence high-density large-scale NV- center ensemble in diamond means that types of room-temperature micro-sized solid-state quantum sensors with ultra-high sensitivity can be further developed in the near future.

  5. Application of annealing for extension of WWER vessel lives

    International Nuclear Information System (INIS)

    Badanin, V.; Dragunow, Yu.G.; Fedorov, V.; Gorynin, I.; Nickolaev, V.

    1992-01-01

    The safe operation of nuclear power plants (NPP) is dependent upon the assurance that the reactor pressure vessel will not fail in a brittle manner when the effects of radiation embrittlement are taken into account. The recovery of the properties of the irradiated materials is an important way of extending the operating life of a reactor vessel. The intent of this paper is to demonstrate the efficiency of thermal annealing for the recovery of reactor vessel material properties and to present the implications for extended service life. In order to substantiate the application of annealing to the extensior of the service life of vessels, detailed investigations were conducted which involved thermal annealing temperature and time, fast neutron fluence, and metallurgical factors (i.e. impurity contents) on the recovery of properties after the annealing of irradiated materials. Similar studies were continued to determine predictive methods for radiation embrittlement after repeated annealings. In May 1987 the first pilot annealing of a commercial reactor vessel (Novo-Voronezhskaya, III, NPP) was performed. The development of the annealing equipment and investigations performed to test the annealing process proved successful, and an improved safe operation for the reactor vessel was thus atttained providing for an extended service life. (orig.)

  6. Direct and pulsed current annealing of p-MOSFET based dosimeter: the "MOSkin".

    Science.gov (United States)

    Alshaikh, Sami; Carolan, Martin; Petasecca, Marco; Lerch, Michael; Metcalfe, Peter; Rosenfeld, Anatoly

    2014-06-01

    Contemporary radiation therapy (RT) is complicated and requires sophisticated real-time quality assurance (QA). While 3D real-time dosimetry is most preferable in RT, it is currently not fully realised. A small, easy to use and inexpensive point dosimeter with real-time and in vivo capabilities is an option for routine QA. Such a dosimeter is essential for skin, in vivo or interface dosimetry in phantoms for treatment plan verification. The metal-oxide-semiconductor-field-effect-transistor (MOSFET) detector is one of the best choices for these purposes, however, the MOSFETs sensitivity and its signal stability degrade after essential irradiation which limits its lifespan. The accumulation of positive charge on the gate oxide and the creation of interface traps near the silicon-silicon dioxide layer is the primary physical phenomena responsible for this degradation. The aim of this study is to investigate MOSFET dosimeter recovery using two proposed annealing techniques: direct current (DC) and pulsed current (PC), both based on hot charged carrier injection into the gate oxide of the p-MOSFET dosimeter. The investigated MOSFETs were reused multiple times using an irradiation-annealing cycle. The effect of the current-annealing parameters was investigated for the dosimetric characteristics of the recovered MOSFET dosimeters such as linearity, sensitivity and initial threshold voltage. Both annealing techniques demonstrated excellent results in terms of maintaining a stable response, linearity and sensitivity of the MOSFET dosimeter. However, PC annealing is more preferable than DC annealing as it offers better dose response linearity of the reused MOSFET and has a very short annealing time.

  7. Effect of thermal annealing on the structure and magnetism of Fe-doped ZnO nanocrystals synthesized by solid state reaction

    Energy Technology Data Exchange (ETDEWEB)

    Wang Dong [Hubei Nuclear Solid Physics Key Laboratory, Department of Physics, Wuhan University, Wuhan 430072 (China); Chen, Z.Q., E-mail: chenzq@whu.edu.c [Hubei Nuclear Solid Physics Key Laboratory, Department of Physics, Wuhan University, Wuhan 430072 (China); Wang, D.D.; Gong, J. [Hubei Nuclear Solid Physics Key Laboratory, Department of Physics, Wuhan University, Wuhan 430072 (China); Cao, C.Y.; Tang, Z. [Department of Electronic and Engineering, East China Normal University, Shanghai 200241 (China); Huang, L.R. [Wuhan National Laboratory for Optoelectronics, College of Opto-electronics Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2010-11-15

    High purity Fe{sub 2}O{sub 3}/ZnO nanocomposites were annealed in air at different temperatures between 100 and 1200 {sup o}C to get Fe-doped ZnO nanocrystals. The structure and grain size of the Fe{sub 2}O{sub 3}/ZnO nanocomposites were investigated by X-ray diffraction 2{theta} scans. Annealing induces an increase of the grain size from 25 to 195 nm and appearance of franklinite phase of ZnFe{sub 2}O{sub 4}. Positron annihilation measurements reveal large number of vacancy defects in the interface region of the Fe{sub 2}O{sub 3}/ZnO nanocomposites, and they are gradually recovered with increasing annealing temperature. After annealing at temperatures higher than 1000 {sup o}C, the number of vacancies decreases to the lower detection limit of positrons. Room temperature ferromagnetism can be observed in Fe-doped ZnO nanocrystals using physical properties measurement system. The ferromagnetism remains after annealing up to 1000 {sup o}C, suggesting that it is not related with the interfacial defects.

  8. Rapid magnetic hardening by rapid thermal annealing in NdFeB-based nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Chu, K.-T.; Jin, Z Q; Chakka, Vamsi M; Liu, J P [Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States)

    2005-11-21

    A systematic study of heat treatments and magnetic hardening of NdFeB-based melt-spun nanocomposite ribbons have been carried out. Comparison was made between samples treated by rapid thermal annealing and by conventional furnace annealing. Heating rates up to 200 K s{sup -1} were adopted in the rapid thermal processing. It was observed that magnetic hardening can be realized in an annealing time as short as 1 s. Coercivity of 10.2 kOe in the nanocomposites has been obtained by rapid thermal annealing for 1 s, and prolonged annealing did not give any increase in coercivity. Detailed results on the effects of annealing time, temperature and heating rate have been obtained. The dependence of magnetic properties on the annealing parameters has been investigated. Structural characterization revealed that there is a close correlation between magnetic hardening and nanostructured morphology. The coercivity mechanism was also studied by analysing the magnetization minor loops.

  9. X-ray diffraction investigation of self-annealing in nanocrystalline copper electrodeposits

    DEFF Research Database (Denmark)

    Pantleon, Karen; Somers, Marcel A. J.

    2006-01-01

    X-ray diffraction analysis and electrical resistivity measurements were conducted simultaneously for in-situ examination of self-annealing in copper electrodeposits. Considerable growth of the as-deposited nano-sized crystallites occurs with time and the crystallographic texture changes by multip...... twinning during self-annealing. The kinetics of self-annealing depends on the layer thickness as well as on the orientation and/or the size of the as-deposited crystallites. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.......X-ray diffraction analysis and electrical resistivity measurements were conducted simultaneously for in-situ examination of self-annealing in copper electrodeposits. Considerable growth of the as-deposited nano-sized crystallites occurs with time and the crystallographic texture changes by multiple...

  10. Influence of annealing conditions on anodic tungsten oxide layers and their photoelectrochemical activity

    International Nuclear Information System (INIS)

    Syrek, Karolina; Zych, Marta; Zaraska, Leszek; Sulka, Grzegorz D.

    2017-01-01

    Highlights: • Effect of annealing temperature on the morphology and crystalline structure of anodic WO 3 was investigated. • Photoelectrochemical properties of WO 3 layers annealed at different temperatures were studied. • Edges of conduction and valence bands were estimated for tungsten oxide layers annealed at different temperatures. • Influence of annealing time on crystalline structure, morphology and photoelectrochemical performance was studied. - Abstract: The nanoporous tungsten oxide films having an amorphous structure were prepared in an electrolyte containing fluoride ions via an anodization process. The as-synthesized anodic oxide layers can be easily converted to the monoclinic WO 3 phase upon annealing in air. The as-synthesized and annealed WO 3 layers were investigated by using X-ray diffraction, scanning electron microscopy, and photocurrent spectroscopy. The effect of annealing temperature and annealing time on the oxide morphology, crystal structure and electrochemical properties were studied. The samples were annealed in air at the temperatures ranging from 400 to 600 °C, and it was found that the original porous morphology of oxide is completely lost after annealing at 600 °C. The changes in the average crystallite sizes upon annealing were confirmed by XRD measurements. The photoelectrochemical performance of the annealed WO 3 layers were studied under pulsed UV illumination, and the highest photocurrents were observed at the incident light wavelength of 350 nm for the sample annealed at 500 °C for 2 h. The band gap energy and the positions of conduction and valence band edges were determined for all studied samples.

  11. Chemical reaction at ferromagnet/oxide interface and its influence on anomalous Hall effect

    International Nuclear Information System (INIS)

    Liu, Yi-Wei; Teng, Jiao; Zhang, Jing-Yan; Liu, Yang; Chen, Xi; Li, Xu-Jing; Feng, Chun; Wang, Hai-Cheng; Li, Ming-Hua; Yu, Guang-Hua; Wu, Zheng-Long

    2014-01-01

    Chemical reactions at the ferromagnet/oxide interface in [Pt/Fe] 3 /MgO and [Pt/Fe] 3 /SiO 2 multilayers before and after annealing were investigated by X-ray photoelectron spectroscopy. The results show that Fe atoms at the Fe/MgO interface were completely oxidized in the as-grown state and significantly deoxidized after vacuum annealing. However, only some of the Fe atoms at the Fe/SiO 2 interface were oxidized and rarely deoxidized after annealing. The anomalous Hall effect was modified by this interfacial chemical reaction. The saturation anomalous Hall resistance (R xy ) was greatly increased in the [Pt/Fe] 3 /MgO multilayers after annealing and was 350% higher than that in the as-deposited film, while R xy of the [Pt/Fe] 3 /SiO 2 multilayer only increased 10% after annealing.

  12. a-Si:H crystallization from isothermal annealing and its dependence on the substrate used

    Energy Technology Data Exchange (ETDEWEB)

    Rojas-Lopez, M., E-mail: marlonrl@yahoo.com.mx [CIBA-Tlaxcala, Instituto Politecnico Nacional, Tepetitla, Tlax. 90700 (Mexico); Orduna-Diaz, A.; Delgado-Macuil, R.; Gayou, V.L.; Bibbins-Martinez, M. [CIBA-Tlaxcala, Instituto Politecnico Nacional, Tepetitla, Tlax. 90700 (Mexico); Torres-Jacome, A.; Trevino-Palacios, C.G. [INAOE, Tonantzintla, Puebla, Pue. 72000 (Mexico)

    2010-10-25

    We present hydrogenated amorphous silicon (a-Si:H) films which were deposited on two different substrates (glass and mono-crystalline silicon) after an isothermal annealing treatment at 250 deg. C for up to 14 h. The annealed amorphous films were analyzed using atomic force microscopy, Raman and FTIR spectroscopy. Films deposited on glass substrate experienced an amorphous-crystalline phase transition after annealing because of the metal-induced crystallization effect, reaching approximately 70% conversion after 14 h of annealing. An absorption frequency of the TO-phonon mode that varies systematically with the substoichiometry of the silicon oxide in the 1046-1170 cm{sup -1} region was observed, revealing the reactivity of the film with the annealing time. For similar annealing time, films deposited on mono-crystalline silicon substrate remained mainly amorphous with minimal Si-crystalline formation. Therefore, the crystalline formations and the shape of the films surfaces depends on the annealing time as well as on the substrate employed during the deposition process of the a-Si:H film.

  13. Effects of methane annealing ambience on the structure and photoluminescence of BCNO phosphors

    International Nuclear Information System (INIS)

    Lu, Fang; Zhang, Xinghua; Lu, Zunming; Tang, Chengchun

    2014-01-01

    Green-emitting BCNO phosphors are synthetized by low temperature liquid method. And then the properties of structure and photoluminescence of BCNO phosphors annealed under methane ambience at 500–700 °C for 4 h and at 600 °C for 3–6 h are researched. When the phosphor was annealed for the same time period, the crystallinity was improved first and then became poor as the annealing temperature increased. In addition, the emission peak shifted to high wavelength, and the maximum shift span reached up to 40 nm. When the phosphor was annealed at the same temperature, the crystallinity was improved and the emission peak was red-shifted. The multi-peaks fitting results indicated that three luminescence mechanisms which were C-related defect, B–O luminescence center and other defects or vacancies played important roles in BCNO phosphors. - Highlights: • When the annealing time period was fixed to 4 h, the XRD results showed the crystallinity was improved at first and then became poor as the annealing temperature increased. Furthermore, the PL results indicated the emission peak was red-shifted and then blue-shifted and the maximum shift span reached up to 40 nm when the annealing temperature was 600 °C. • With regard to the samples annealed at 600 °C for 3, 4, 5 and 6 h respectively, the crystallinity was improved as the annealing time period prolonged. In addition, the emission peak was red-shifted first and then blue-shifted and the maximum shift span reached up to 40 nm when the annealing time was 4 h. • What's more, the three-peaks fitting graphs uncovered that the luminescence properties were decided by three mechanisms which were C-related defect, B–O luminescence center and other defects or vacancies. Therefore, the peakshift and luminescence intensity were influenced by the comprehensive superposition of these three factors. • In this work, we found the inter luminescence mechanisms of BCNO phosphor by the annealing experiments under methane

  14. Propagating self-sustained annealing of radiation-induced interstitial complexes

    International Nuclear Information System (INIS)

    Bokov, P M; Selyshchev, P A

    2016-01-01

    A propagating self-sustained annealing of radiation induced defects as a result of thermal-concentration instability is studied. The defects that are considered in the model are complexes. Each of them consists of one atom of impunity and of one interstitial atom. Crystal with defects has extra energy which is transformed into heat during defect annealing. Simulation of the auto-wave of annealing has been performed. The front and the speed of the auto-wave have been obtained. It is shown that annealing occurs in a narrow region of time and space. There are two kinds of such annealing behaviour. In the first case the speed of the auto-wave oscillates near its constant mean value and the front of temperature oscillates in a complex way. In the second case the speed of propagation is constant and fronts of temperature and concentration look like sigmoid functions. (paper)

  15. Effect of isothermal annealing on the compressive strength of a ZrAlNiCuNb metallic glass

    International Nuclear Information System (INIS)

    Song Min; He Yuehui

    2011-01-01

    Research highlights: → Only structural relaxation happens during annealing at the temperature below T g . → Nanocrystallization happens during annealing at the temperature above T g . → The compressive strength increases with annealing time up to 20 min. → The compressive strength decreases with annealing time after 20 min. - Abstract: The effects of isothermal annealing on the microstructures and compressive strength of a Zr 56 Al 10.9 Ni 4.6 Cu 27.8 Nb 0.7 bulk metallic glass (BMG) have been studied using X-ray diffraction, scanning electron microscopy and compression tests. It has been shown that only structural relaxation happens during annealing at the temperature below T g (glass transition temperature), while both structural relaxation and nanocrystallization happen during annealing at the temperature above T g . Compression tests indicated that the strength of the BMG increases with annealing time at 437 deg. C up to 20 min, after which the strength starts to decrease. The strength evolution of the BMG with the annealing time is due to combined effects of the variations of the free volume and nanocrystals.

  16. Synergic solventing-out crystallization with subsequent time-delay thermal annealing of PbI2 precursor in mesostructured perovskite solar cells

    Science.gov (United States)

    Jia, Fujin; Guo, Yanqun; Che, Lijia; Liu, Zhiyong; Zeng, Zhigang; Cai, Chuanbing

    2018-06-01

    Although the two-step sequential deposition method provides an efficient route to fabricate high performance perovskite solar cells (PSSCs) with increasing reproducibility, the inefficient and incomplete conversion of PbI2 to perovskite is still quite a challenge. Following pioneering works, we found that the conversion process from PbI2 to perovskite mainly involves diffusion, infiltration, contact and reaction. In order to facilitate the conversion from PbI2 to perovskite, we demonstrate an effective method to regulate supersaturation level (the driving force to crystallization) of PbI2 by solventing-out crystallization combining with subsequent time-delay thermal annealing of PbI2 wet film. Enough voids and spaces in resulting porous PbI2 layer will be in favor of efficient diffusion, infiltration of CH3NH3I solution, and further enhance the contact and reaction between PbI2 and CH3NH3I in the whole film, leading to rapid, efficient and complete perovskite conversion with a conversion level of about 99.9%. Enhancement of light harvesting ranging from visible to near-IR region was achieved for the resultant high-quality perovskite. Upon this combined method, the fabricated mesostructured solar cells show tremendous power conversion efficiency (PCE) improvement from 3.2% to about 12.3% with less hysteresis owing to the simultaneous enhancement of short-circuit photocurrent density (J sc), open-circuit voltage (V oc) and fill factor (FF).

  17. Crystallization degree change of expanded graphite by milling and annealing

    International Nuclear Information System (INIS)

    Tang Qunwei; Wu Jihuai; Sun Hui; Fang Shijun

    2009-01-01

    Expanded graphite was ball milled with a planetary mill in air atmosphere, and subsequently thermal annealed. The samples were characterized by using X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA). It was found that in the milling initial stage (less than 12 h), the crystallization degree of the expanded graphite declined gradually, but after milling more than 16 h, a recrystallization of the expanded graphite toke place, and ordered nanoscale expanded graphite was formed gradually. In the annealing initial stage, the non-crystallization of the graphite occurred, but, beyond an annealing time, recrystallizations of the graphite arise. Higher annealing temperature supported the recrystallization. The milled and annealed expanded graphite still preserved the crystalline structure as raw material and hold high thermal stability.

  18. RecO protein initiates DNA recombination and strand annealing through two alternative DNA binding mechanisms.

    Science.gov (United States)

    Ryzhikov, Mikhail; Gupta, Richa; Glickman, Michael; Korolev, Sergey

    2014-10-17

    Recombination mediator proteins (RMPs) are important for genome stability in all organisms. Several RMPs support two alternative reactions: initiation of homologous recombination and DNA annealing. We examined mechanisms of RMPs in both reactions with Mycobacterium smegmatis RecO (MsRecO) and demonstrated that MsRecO interacts with ssDNA by two distinct mechanisms. Zinc stimulates MsRecO binding to ssDNA during annealing, whereas the recombination function is zinc-independent and is regulated by interaction with MsRecR. Thus, different structural motifs or conformations of MsRecO are responsible for interaction with ssDNA during annealing and recombination. Neither annealing nor recombinase loading depends on MsRecO interaction with the conserved C-terminal tail of single-stranded (ss) DNA-binding protein (SSB), which is known to bind Escherichia coli RecO. However, similarly to E. coli proteins, MsRecO and MsRecOR do not dismiss SSB from ssDNA, suggesting that RMPs form a complex with SSB-ssDNA even in the absence of binding to the major protein interaction motif. We propose that alternative conformations of such complexes define the mechanism by which RMPs initiate the repair of stalled replication and support two different functions during recombinational repair of DNA breaks. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Determining Annealing Temperatures for Polymerase Chain Reaction

    Science.gov (United States)

    Porta, Angela R.; Enners, Edward

    2012-01-01

    The polymerase chain reaction (PCR) is a common technique used in high school and undergraduate science teaching. Students often do not fully comprehend the underlying principles of the technique and how optimization of the protocol affects the outcome and analysis. In this molecular biology laboratory, students learn the steps of PCR with an…

  20. Luminescence lifetimes in quartz: dependence on annealing temperature prior to beta irradiation

    International Nuclear Information System (INIS)

    Galloway, R.B.

    2002-01-01

    It is well known that the thermal history of a quartz sample influences the optically stimulated luminescence sensitivity of the quartz. It is found that the optically stimulated luminescence lifetime, determined from time resolved spectra obtained with pulsed stimulation, also depends on past thermal treatment. For samples at 20 deg. C during stimulation, the lifetime depends on beta dose and on duration of preheating at 220 deg. C prior to stimulation for quartz annealed at 600 deg. C and above, but is independent of these factors for quartz annealed at 500 deg. C and below. For stimulation at higher temperatures, the lifetime becomes shorter if the sample is held at temperatures above 125 deg. C during stimulation, in a manner consistent with thermal quenching. A single exponential decay is all that is required to fit the time resolved spectra for un-annealed quartz regardless of the temperature during stimulation (20-175 deg. C), or to fit the time resolved spectra from all samples held at 20 deg. C during stimulation, regardless of annealing temperature (20-1000 deg. C). An additional shorter lifetime is found for some combinations of annealing temperature and temperature during stimulation. The results are discussed in terms of a model previously used to explain thermal sensitisation. The luminescence lifetime data are best explained by the presence of two principal luminescence centres, their relative importance depending on the annealing temperature, with a third centre involved for limited combinations of annealing temperature and temperature during stimulation

  1. In Situ Apparatus to Study Gas-Metal Reactions and Wettability at High Temperatures for Hot-Dip Galvanizing Applications

    Science.gov (United States)

    Koltsov, A.; Cornu, M.-J.; Scheid, J.

    2018-02-01

    The understanding of gas-metal reactions and related surface wettability at high temperatures is often limited due to the lack of in situ surface characterization. Ex situ transfers at low temperature between annealing furnace, wettability device, and analytical tools induce noticeable changes of surface composition distinct from the reality of the phenomena.Therefore, a high temperature wettability device was designed in order to allow in situ sample surface characterization by x-rays photoelectron spectroscopy after gas/metal and liquid metal/solid metal surface reactions. Such airless characterization rules out any contamination and oxidation of surfaces and reveals their real composition after heat treatment and chemical reaction. The device consists of two connected reactors, respectively, dedicated to annealing treatments and wettability measurements. Heat treatments are performed in an infrared lamp furnace in a well-controlled atmosphere conditions designed to reproduce gas-metal reactions occurring during the industrial recrystallization annealing of steels. Wetting experiments are carried out in dispensed drop configuration with the precise control of the deposited droplets kinetic energies. The spreading of drops is followed by a high-speed CCD video camera at 500-2000 frames/s in order to reach information at very low contact time. First trials have started to simulate phenomena occurring during recrystallization annealing and hot-dip galvanizing on polished pure Fe and FeAl8 wt.% samples. The results demonstrate real surface chemistry of steel samples after annealing when they are put in contact with liquid zinc alloy bath during hot-dip galvanizing. The wetting results are compared to literature data and coupled with the characterization of interfacial layers by FEG-Auger. It is fair to conclude that the results show the real interest of such in situ experimental setup for interfacial chemistry studies.

  2. Ultrafast Self-Assembly of Sub-10 nm Block Copolymer Nanostructures by Solvent-Free High-Temperature Laser Annealing.

    Science.gov (United States)

    Jiang, Jing; Jacobs, Alan G; Wenning, Brandon; Liedel, Clemens; Thompson, Michael O; Ober, Christopher K

    2017-09-20

    Laser spike annealing was applied to PS-b-PDMS diblock copolymers to induce short-time (millisecond time scale), high-temperature (300 to 700 °C) microphase segregation and directed self-assembly of sub-10 nm features. Conditions were identified that enabled uniform microphase separation in the time frame of tens of milliseconds. Microphase ordering improved with increased temperature and annealing time, whereas phase separation contrast was lost for very short annealing times at high temperature. PMMA brush underlayers aided ordering under otherwise identical laser annealing conditions. Good long-range order for sub-10 nm cylinder morphology was achieved using graphoepitaxy coupled with a 20 ms dwell laser spike anneal above 440 °C.

  3. DOE's annealing prototype demonstration projects

    International Nuclear Information System (INIS)

    Warren, J.; Nakos, J.; Rochau, G.

    1997-01-01

    One of the challenges U.S. utilities face in addressing technical issues associated with the aging of nuclear power plants is the long-term effect of plant operation on reactor pressure vessels (RPVs). As a nuclear plant operates, its RPV is exposed to neutrons. For certain plants, this neutron exposure can cause embrittlement of some of the RPV welds which can shorten the useful life of the RPV. This RPV embrittlement issue has the potential to affect the continued operation of a number of operating U.S. pressurized water reactor (PWR) plants. However, RPV material properties affected by long-term irradiation are recoverable through a thermal annealing treatment of the RPV. Although a dozen Russian-designed RPVs and several U.S. military vessels have been successfully annealed, U.S. utilities have stated that a successful annealing demonstration of a U.S. RPV is a prerequisite for annealing a licensed U.S. nuclear power plant. In May 1995, the Department of Energy's Sandia National Laboratories awarded two cost-shared contracts to evaluate the feasibility of annealing U.S. licensed plants by conducting an anneal of an installed RPV using two different heating technologies. The contracts were awarded to the American Society of Mechanical Engineers (ASME) Center for Research and Technology Development (CRTD) and MPR Associates (MPR). The ASME team completed its annealing prototype demonstration in July 1996, using an indirect gas furnace at the uncompleted Public Service of Indiana's Marble Hill nuclear power plant. The MPR team's annealing prototype demonstration was scheduled to be completed in early 1997, using a direct heat electrical furnace at the uncompleted Consumers Power Company's nuclear power plant at Midland, Michigan. This paper describes the Department's annealing prototype demonstration goals and objectives; the tasks, deliverables, and results to date for each annealing prototype demonstration; and the remaining annealing technology challenges

  4. Molecular motions in sucrose-PVP and sucrose-sorbitol dispersions-II. Implications of annealing on secondary relaxations.

    Science.gov (United States)

    Bhattacharya, Sisir; Bhardwaj, Sunny P; Suryanarayanan, Raj

    2014-10-01

    To determine the effect of annealing on the two secondary relaxations in amorphous sucrose and in sucrose solid dispersions. Sucrose was co-lyophilized with either PVP or sorbitol, annealed for different time periods and analyzed by dielectric spectroscopy. In an earlier investigation, we had documented the effect of PVP and sorbitol on the primary and the two secondary relaxations in amorphous sucrose solid dispersions (1). Here we investigated the effect of annealing on local motions, both in amorphous sucrose and in the dispersions. The average relaxation time of the local motion (irrespective of origin) in sucrose, decreased upon annealing. However, the heterogeneity in relaxation time distribution as well as the dielectric strength decreased only for β1- (the slower relaxation) but not for β2-relaxations. The effect of annealing on β2-relaxation times was neutralized by sorbitol while PVP negated the effect of annealing on both β1- and β2-relaxations. An increase in local mobility of sucrose brought about by annealing could be negated with an additive.

  5. High temperature annealing effect on structural and magnetic properties of Ti/Ni multilayers

    International Nuclear Information System (INIS)

    Bhatt, Pramod; Ganeshan, V.; Reddy, V.R.; Chaudhari, S.M.

    2006-01-01

    High temperature annealing effect on structural and magnetic properties of Ti/Ni multilayer (ML) up to 600 deg. C have been studied and reported in this paper. Ti/Ni multilayer samples having constant layer thicknesses of 50 A each are deposited on float glass and Si(1 1 1) substrates using electron-beam evaporation technique under ultra-high vacuum (UHV) conditions at room temperatures. The micro-structural parameters and their evolution with temperature for as-deposited as well as annealed multilayer samples up to 600 deg. C in a step of 100 deg. C for 1 h are determined by using X-ray diffraction (XRD) and grazing incidence X-ray reflectivity techniques. The X-ray diffraction pattern recorded at 300 deg. C annealed multilayer sample shows interesting structural transformation (from crystalline to amorphous) because of the solid-state reaction (SSR) and subsequent re-crystallization at higher temperatures of annealing, particularly at ≥400 deg. C due to the formation of TiNi 3 and Ti 2 Ni alloy phases. Sample quality and surface morphology are examined by using atomic force microscopy (AFM) technique for both as-deposited as well as annealed multilayer samples. In addition to this, a temperature dependent dc resistivity measurement is also used to study the structural transformation and subsequent alloy phase formation due to annealing treatment. The corresponding magnetization behavior of multilayer samples after each stage of annealing has been investigated by using Magneto-Optical Kerr Effect (MOKE) technique and results are interpreted in terms of observed micro-structural changes

  6. Oxidation phase growth diagram of vanadium oxides film fabricated by rapid thermal annealing

    Institute of Scientific and Technical Information of China (English)

    Tamura KOZO; Zheng-cao LI; Yu-quan WANG; Jie NI; Yin HU; Zheng-jun ZHANG

    2009-01-01

    Thermal evaporation deposited vanadium oxide films were annealed in air by rapid thermal annealing (RTP). By adjusting the annealing temperature and time, a series of vanadium oxide films with various oxidation phases and surface morphologies were fabricated, and an oxidation phase growth diagram was established. It was observed that different oxidation phases appear at a limited and continuous annealing condition range, and the morphologic changes are related to the oxidation process.

  7. New heating schedule in hydrogen annealing furnace based on process simulation for less energy consumption

    International Nuclear Information System (INIS)

    Saboonchi, Ahmad; Hassanpour, Saeid; Abbasi, Shahram

    2008-01-01

    Cold rolled steel coils are annealed in batch furnaces to obtain desirable mechanical properties. Annealing operations involve heating and cooling cycles which take long due to high weight of the coils under annealing. To reduce annealing time, a simulation code was developed that is capable of evaluating more effective schedules for annealing coils during the heating process. This code is additionally capable of accurate determination of furnace turn-off time for different coil weights and charge dimensions. After studying many heating schedules and considering heat transfer mechanism in the annealing furnace, a new schedule with the most advantages was selected as the new operation conditions in the hydrogen annealing plant. The performance of all the furnaces were adjusted to the new heating schedule after experiments had been carried out to ensure the accuracy of the code and the fitness of the new operation condition. Comparison of similar yield of cold rolled coils over two months revealed that specific energy consumption of furnaces under the new heating schedule decreased by 11%, heating cycle time by 16%, and the hydrogen consumption by 14%

  8. New heating schedule in hydrogen annealing furnace based on process simulation for less energy consumption

    Energy Technology Data Exchange (ETDEWEB)

    Saboonchi, Ahmad [Department of Mechanical Engineering, Isfahan University of Technology, Isfahan 84154 (Iran); Hassanpour, Saeid [Rayan Tahlil Sepahan Co., Isfahan Science and Technology Town, Isfahan 84155 (Iran); Abbasi, Shahram [R and D Department, Mobarakeh Steel Complex, Isfahan (Iran)

    2008-11-15

    Cold rolled steel coils are annealed in batch furnaces to obtain desirable mechanical properties. Annealing operations involve heating and cooling cycles which take long due to high weight of the coils under annealing. To reduce annealing time, a simulation code was developed that is capable of evaluating more effective schedules for annealing coils during the heating process. This code is additionally capable of accurate determination of furnace turn-off time for different coil weights and charge dimensions. After studying many heating schedules and considering heat transfer mechanism in the annealing furnace, a new schedule with the most advantages was selected as the new operation conditions in the hydrogen annealing plant. The performance of all the furnaces were adjusted to the new heating schedule after experiments had been carried out to ensure the accuracy of the code and the fitness of the new operation condition. Comparison of similar yield of cold rolled coils over two months revealed that specific energy consumption of furnaces under the new heating schedule decreased by 11%, heating cycle time by 16%, and the hydrogen consumption by 14%. (author)

  9. Effect of annealing treatments on normal state resistivity of YBa 2 ...

    African Journals Online (AJOL)

    Samples of YBa2(Cu1-xTix)3Oy superconductor with x=0.00 , 0.01, 0.03 have been prepared by solide state reaction method. The effect of annealing treatments on normal electrical resistivity has been done using the bipolaron model. The results of this study show the increase of localized charge when the dopant content ...

  10. Finite-time barriers to reaction front propagation

    Science.gov (United States)

    Locke, Rory; Mahoney, John; Mitchell, Kevin

    2015-11-01

    Front propagation in advection-reaction-diffusion systems gives rise to rich geometric patterns. It has been shown for time-independent and time-periodic fluid flows that invariant manifolds, termed burning invariant manifolds (BIMs), serve as one-sided dynamical barriers to the propagation of reaction front. More recently, theoretical work has suggested that one-sided barriers, termed burning Lagrangian Coherent structures (bLCSs), exist for fluid velocity data prescribed over a finite time interval, with no assumption on the time-dependence of the flow. In this presentation, we use a time-varying fluid ``wind'' in a double-vortex channel flow to demonstrate that bLCSs form the (locally) most attracting or repelling fronts.

  11. The effects of acute bout of cycling on auditory & visual reaction times.

    Science.gov (United States)

    Ashnagar, Zinat; Shadmehr, Azadeh; Jalaei, Shohreh

    2015-04-01

    The purpose of this study was to investigate the effects of an acute bout of cycling exercise on auditory choice reaction time, visual choice reaction time, auditory complex choice reaction time and visual complex choice reaction time. 29 subjects were randomly divided into experimental and control groups. The subjects of the experimental group carried out a single bout of submaximal cycling exercise. The auditory choice reaction time, visual choice reaction time, auditory complex choice reaction time and visual complex choice reaction times were measured before and after the exercise session. The reaction time tests were taken from the subjects by using Speed Anticipation and Reaction Tester (SART) software. In the control group, the reaction time tests were performed by the subjects with an interval of 30 min. In the experimental group, the percentage changes of mean auditory choice and complex choice reaction time values were significantly decreased in comparison with the control group (P visual choice and complex choice reaction times were decreased after the exercise, the changes were not significant (P > 0.05). An acute bout of cycling exercise improved the speed of auditory and visual reaction times in healthy young females. However, these positive changes were significantly observed only in the auditory reaction time tests in comparison with the control group. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. The effect of annealing on the time-dependent behavior of isotactic polypropylene at finite strains

    DEFF Research Database (Denmark)

    Drozdov, Aleksey D.; Christiansen, Jesper de Claville

    2002-01-01

    Four series of tensile relaxation tests are performed on isotactic polypropylene at elongations up to the necking point. In the first series of experiments, injection-molded samples are used without thermal pre-treatment. In the other series, the specimens are annealed for 24 h prior to testing a...... at annealing. In the post-critical region (large strains), an increase in the fraction of active amorphous domains is attributed to disintegration of primary (thick) lamellae....

  13. Reactions and Diffusion During Annealing-Induced H(+) Generation in SOI Buried Oxides

    International Nuclear Information System (INIS)

    Devine, R.A.B.; Fleetwood, D.M.; Vanheusden, K; Warren, W.L.

    1999-01-01

    We report experimental results suggesting that mobile protons are generated at strained Si-O-Si bonds near the Si/SiO 2 interface during annealing in forming gas. Our data further suggest that the presence of the top Si layer plays a crucial role in the mobile H + generation process. Finally, we show that the diffusion of the reactive species (presumably H 2 or H 0 ) towards the H + generation sites occurs laterally along the buried oxide layer, and can be impeded significantly due to the presence of trapping sites in the buried oxide

  14. Semiconductor annealing

    International Nuclear Information System (INIS)

    Young, J.M.; Scovell, P.D.

    1982-01-01

    A process for annealing crystal damage in ion implanted semiconductor devices in which the device is rapidly heated to a temperature between 450 and 900 0 C and allowed to cool. It has been found that such heating of the device to these relatively low temperatures results in rapid annealing. In one application the device may be heated on a graphite element mounted between electrodes in an inert atmosphere in a chamber. (author)

  15. Remarkably Enhanced Room-Temperature Hydrogen Sensing of SnO₂ Nanoflowers via Vacuum Annealing Treatment.

    Science.gov (United States)

    Liu, Gao; Wang, Zhao; Chen, Zihui; Yang, Shulin; Fu, Xingxing; Huang, Rui; Li, Xiaokang; Xiong, Juan; Hu, Yongming; Gu, Haoshuang

    2018-03-23

    In this work, SnO₂ nanoflowers synthesized by a hydrothermal method were employed as hydrogen sensing materials. The as-synthesized SnO₂ nanoflowers consisted of cuboid-like SnO₂ nanorods with tetragonal structures. A great increase in the relative content of surface-adsorbed oxygen was observed after the vacuum annealing treatment, and this increase could have been due to the increase in surface oxygen vacancies serving as preferential adsorption sites for oxygen species. Annealing treatment resulted in an 8% increase in the specific surface area of the samples. Moreover, the conductivity of the sensors decreased after the annealing treatment, which should be attributed to the increase in electron scattering around the defects and the compensated donor behavior of the oxygen vacancies due to the surface oxygen adsorption. The hydrogen sensors of the annealed samples, compared to those of the unannealed samples, exhibited a much higher sensitivity and faster response rate. The sensor response factor and response rate increased from 27.1% to 80.2% and 0.34%/s to 1.15%/s, respectively. This remarkable enhancement in sensing performance induced by the annealing treatment could be attributed to the larger specific surface areas and higher amount of surface-adsorbed oxygen, which provides a greater reaction space for hydrogen. Moreover, the sensors with annealed SnO₂ nanoflowers also exhibited high selectivity towards hydrogen against CH₄, CO, and ethanol.

  16. Roles of fluorine and annealing on optical and structural properties of Nd:YF{sub 3} phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Santos, H.D.A.; Novais, S.M.V.; Jacinto, C., E-mail: cjacinto@fis.ufal.br

    2016-07-15

    The optical and structural properties of Nd:YF{sub 3} phosphors, synthesized by precipitation reaction using ethylene glycol solvent, were investigated. The Y:F molar ratio of precursors, where NH{sub 4}F was employed as the fluorine source, was varied to prevent oxygen contamination during nucleation of the particles and to improve the photoluminescence efficiency. Structural investigations were carried out by means of X-ray diffraction, Fourier transform infrared spectroscopy and energy dispersive X-ray techniques. Samples prepared using precursors in stoichiometric proportion presented orthorhombic YF{sub 3} structure. The use of fluorine source in excess promoted formation of NH{sub 4}Y{sub 2}F{sub 7} crystalline phase, which was decomposed into YF{sub 3} after annealing at 400 °C for 1 h. Emission spectra of samples thermally treated enhanced by over 50 times compared with the as prepared. The results obtained show the role of fluorine excess associated with thermal annealing to obtain YF{sub 3} with improved features.

  17. Positron annihilation studies on reactor irradiated and thermal annealed ferrocene

    International Nuclear Information System (INIS)

    Marques Netto, A.; Carvalho, R.S.; Magalhaes, W.F.; Sinisterra, R.D.

    1996-01-01

    Retention and thermal annealing following (n, γ) reaction in solid ferrocene, Fe(C 5 H 5 ) 2 , were studied by positron annihilation lifetime spectroscopy (PAL). Positronium (Ps) formation was observed in the non-irradiated compound with a probability or intensity (I 3 ) of 30%. Upon irradiation of the compound with thermal neutrons in a nuclear reactor, I 3 decreases with increasing irradiation time. Thermal treatment again increases I 3 values from 16% to 25%, revealing an important proportion of molecular reformation without variation of the ortho-positronium lifetime (τ 3 ). These results point out the major influence of the electronic structure as determining the Ps yields in the pure complex. In the irradiated and non irradiated complexes the results are satisfactorily explained on the basis of the spur model. (orig.)

  18. Autonomous Vehicles: Disengagements, Accidents and Reaction Times.

    Directory of Open Access Journals (Sweden)

    Vinayak V Dixit

    Full Text Available Autonomous vehicles are being viewed with scepticism in their ability to improve safety and the driving experience. A critical issue with automated driving at this stage of its development is that it is not yet reliable and safe. When automated driving fails, or is limited, the autonomous mode disengages and the drivers are expected to resume manual driving. For this transition to occur safely, it is imperative that drivers react in an appropriate and timely manner. Recent data released from the California trials provide compelling insights into the current factors influencing disengagements of autonomous mode. Here we show that the number of accidents observed has a significantly high correlation with the autonomous miles travelled. The reaction times to take control of the vehicle in the event of a disengagement was found to have a stable distribution across different companies at 0.83 seconds on average. However, there were differences observed in reaction times based on the type of disengagements, type of roadway and autonomous miles travelled. Lack of trust caused by the exposure to automated disengagements was found to increase the likelihood to take control of the vehicle manually. Further, with increased vehicle miles travelled the reaction times were found to increase, which suggests an increased level of trust with more vehicle miles travelled. We believe that this research would provide insurers, planners, traffic management officials and engineers fundamental insights into trust and reaction times that would help them design and engineer their systems.

  19. Autonomous Vehicles: Disengagements, Accidents and Reaction Times.

    Science.gov (United States)

    Dixit, Vinayak V; Chand, Sai; Nair, Divya J

    2016-01-01

    Autonomous vehicles are being viewed with scepticism in their ability to improve safety and the driving experience. A critical issue with automated driving at this stage of its development is that it is not yet reliable and safe. When automated driving fails, or is limited, the autonomous mode disengages and the drivers are expected to resume manual driving. For this transition to occur safely, it is imperative that drivers react in an appropriate and timely manner. Recent data released from the California trials provide compelling insights into the current factors influencing disengagements of autonomous mode. Here we show that the number of accidents observed has a significantly high correlation with the autonomous miles travelled. The reaction times to take control of the vehicle in the event of a disengagement was found to have a stable distribution across different companies at 0.83 seconds on average. However, there were differences observed in reaction times based on the type of disengagements, type of roadway and autonomous miles travelled. Lack of trust caused by the exposure to automated disengagements was found to increase the likelihood to take control of the vehicle manually. Further, with increased vehicle miles travelled the reaction times were found to increase, which suggests an increased level of trust with more vehicle miles travelled. We believe that this research would provide insurers, planners, traffic management officials and engineers fundamental insights into trust and reaction times that would help them design and engineer their systems.

  20. Autonomous Vehicles: Disengagements, Accidents and Reaction Times

    Science.gov (United States)

    Dixit, Vinayak V.; Chand, Sai; Nair, Divya J.

    2016-01-01

    Autonomous vehicles are being viewed with scepticism in their ability to improve safety and the driving experience. A critical issue with automated driving at this stage of its development is that it is not yet reliable and safe. When automated driving fails, or is limited, the autonomous mode disengages and the drivers are expected to resume manual driving. For this transition to occur safely, it is imperative that drivers react in an appropriate and timely manner. Recent data released from the California trials provide compelling insights into the current factors influencing disengagements of autonomous mode. Here we show that the number of accidents observed has a significantly high correlation with the autonomous miles travelled. The reaction times to take control of the vehicle in the event of a disengagement was found to have a stable distribution across different companies at 0.83 seconds on average. However, there were differences observed in reaction times based on the type of disengagements, type of roadway and autonomous miles travelled. Lack of trust caused by the exposure to automated disengagements was found to increase the likelihood to take control of the vehicle manually. Further, with increased vehicle miles travelled the reaction times were found to increase, which suggests an increased level of trust with more vehicle miles travelled. We believe that this research would provide insurers, planners, traffic management officials and engineers fundamental insights into trust and reaction times that would help them design and engineer their systems. PMID:27997566

  1. The Effects of Annealing Parameters on the Crystallization and Morphology of Cu(In,GaSe2 Absorber Layers Prepared by Annealing Stacked Metallic Precursors

    Directory of Open Access Journals (Sweden)

    Chia-Ho Huang

    2014-01-01

    Full Text Available CIGS films are prepared by single-stage annealing of the solid Se-coated In/Cu-Ga bilayer precursor. The annealing processes were performed using various Ar pressures, heating rates, and soaking times. A higher Ar pressure is needed to fabricate highly crystalline CIGS films, as no extra Se-vapor source is supplied. As the heating rate increases, the surface morphologies of the CIGS films become looser and some cracks are observed. However, the influence of soaking time is insignificant and the selenization process only requires a short time when the precursors are selenized at a higher temperature with a lower heating rate and a higher Ar pressure. In this study, a dense chalcopyrite CIGS film with a thickness of about 1.5-1.6 μm, with large grains (~1.2 μm and no cracking or peeling is obtained after selenizing at a temperature of 550°C, an Ar pressure of 300 Torr, a heating rate of 60°C/min, and a soaking time of 20 min. By adequate design of the stacked precursor and controlling the annealing parameters, single-stage annealing of the solid Se-coated In/Cu-Ga bilayer precursor is simplified for the fabrication of a fully crystallized chalcopyrite CIGS absorber layers with good crystallization and large grains.

  2. Coupled Qubits for Next Generation Quantum Annealing: Improving Coherence

    Science.gov (United States)

    Weber, Steven; Samach, Gabriel; Hover, David; Rosenberg, Danna; Yoder, Jonilyn; Kim, David K.; Kerman, Andrew; Oliver, William D.

    Quantum annealing is an optimization technique which potentially leverages quantum tunneling to enhance computational performance. Existing quantum annealers use superconducting flux qubits with short coherence times, limited primarily by the use of large persistent currents. Here, we examine an alternative approach, using flux qubits with smaller persistent currents and longer coherence times. We demonstrate tunable coupling, a basic building-block for quantum annealing, between two such qubits. Furthermore, we characterize qubit coherence as a function of coupler setting and investigate the effect of flux noise in the coupler loop on qubit coherence. Our results provide insight into the available design space for next-generation quantum annealers with improved coherence. This research was funded by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA) and by the Assistant Secretary of Defense for Research & Engineering under Air Force Contract No. FA8721-05-C-0002. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of ODNI, IARPA, or the US Government.

  3. No Evidence of Reaction Time Slowing in Autism Spectrum Disorder

    Science.gov (United States)

    Ferraro, F. Richard

    2016-01-01

    A total of 32 studies comprising 238 simple reaction time and choice reaction time conditions were examined in individuals with autism spectrum disorder (n?=?964) and controls (n?=?1032). A Brinley plot/multiple regression analysis was performed on mean reaction times, regressing autism spectrum disorder performance onto the control performance as…

  4. Projection of the annealing behavior of irradiated Si sensors in the LHC environment

    CERN Document Server

    Chatterji, S; Bhardwaj, N; Chauhan, S S; Choudhary, B C; Gupta, P; Jha, M; Kumar, A; Naimuddin, M; Ranjan, K; Shivpuri, R K; Srivastava-Ajay, K

    2004-01-01

    The study of the radiation tolerance and subsequent annealing effects on p+-n-n+ silicon micro strip detectors has been performed as a part of R&D program for the preshower detector in the CMS experiment. CMS silicon strip sensors were irradiated with 24 GeV protons at CERN proton synchrotron (PS) to a total fluence of 3*10/sup 14/ p/cm/sup 2 /. Sensors were stored in freezer after irradiation and I-V and C-V measurements were carried out. Variation in full depletion voltage and leakage current have been studied as a function of annealing time. The breakdown performance of the device actually improves after irradiation due to the beneficial effect of type-inversion. The breakdown voltage increases further with annealing time. However, the leakage current increases tremendously just after irradiation. As the sensors are annealed, there is a drop in leakage current. The rate of annealing is observed to be temperature dependent. Hence in terms of leakage current, it seems that room temperature annealing is b...

  5. Order-disorder transitions in lattice gases with annealed reactive constraints

    Science.gov (United States)

    Dudka, Maxym; Bénichou, Olivier; Oshanin, Gleb

    2018-04-01

    We study equilibrium properties of catalytically-activated reactions taking place on a lattice of adsorption sites. The particles undergo continuous exchanges with a reservoir maintained at a constant chemical potential μ and react when they appear at the neighbouring sites, provided that some reactive conditions are fulfilled. We model the latter in two different ways: in the Model I some fraction p of the bonds connecting neighbouring sites possesses special catalytic properties such that any two As appearing on the sites connected by such a bond instantaneously react and desorb. In the Model II some fraction p of the adsorption sites possesses such properties and neighbouring particles react if at least one of them resides on a catalytic site. For the case of annealed disorder in the distribution of the catalyst, which is tantamount to the situation when the reaction may take place at any point on the lattice but happens with a finite probability p, we provide an exact solution for both models for the interior of an infinitely large Cayley tree—the so-called Bethe lattice. We show that both models exhibit a rich critical behaviour: for the annealed Model I it is characterised by a transition into an ordered state and a re-entrant transition into a disordered phase, which both are continuous. For the annealed Model II, which represents a rather exotic model of statistical mechanics in which interactions of any particle with its environment have a peculiar Boolean form, the transition to an ordered state is always continuous, while the re-entrant transition into the disordered phase may be either continuous or discontinuous, depending on the value of p.

  6. Effect of annealing process on TiN/TiC bilayers grown by pulsed arc discharge

    International Nuclear Information System (INIS)

    Ramos-Rivera, L.; Escobar, D.; Benavides-Palacios, V.; Arango, P.J.; Restrepo-Parra, E.

    2012-01-01

    In this work, a study of annealing process effect on TiN/TiC bilayer is presented. The annealing temperature was varied between room temperature and 500 °C. Materials were produced by the plasma-assisted pulsed vacuum arc discharge technique. In order to grow the films, a target of Ti with 99.9999% purity and stainless-steel 304 substrate were used. For the production of TiN layer, the reaction chamber was filled up with nitrogen gas until reaching 25 Pa and the discharge was performed at 310 V. The TiC layer was grown in a methane atmosphere at 30 Pa and 270 V. X-ray diffraction and X photoelectron spectroscopy were employed for studying the structure and chemical composition evolution during the annealing process. At 400 °C, TiO 2 phase begun to appear and it was well observed at 500 °C. Crystallite size and microstrain was obtained as a function of the annealing temperature. XPS technique was employed for analyzing the bilayers before and after the annealing process. Narrow spectra of Ti2p, N1s and O1s were obtained, presenting TiO phases.

  7. Effect of annealing time and NH3 flow on GaN films deposited on amorphous SiO2 by MOCVD

    Science.gov (United States)

    Li, Tianbao; Liu, Chenyang; Zhang, Zhe; Yu, Bin; Dong, Hailiang; Jia, Wei; Jia, Zhigang; Yu, Chunyan; Xu, Bingshe

    2018-05-01

    GaN polycrystalline films were successfully grown on amorphous SiO2 by metal-organic chemical vapour deposition to fabricate transferable devices using inorganic films. Field-emission scanning electron microscopy images show that by prolonging the annealing time, re-evaporation is enhanced, which reduced the uniformity of the nucleation layer and GaN films. X-ray diffraction patterns indicate that the decomposition rate of the nucleation layer increases when the annealing flow rate of NH3 is 500 sccm, which makes the unstable plane and amorphous domains decompose rapidly, thereby improving the crystallinity of the GaN films. Photoluminescence spectra also indicate the presence of fewer defects when the annealing flow rate of NH3 is 500 sccm. The excellent crystal structure of the GaN films grown under optimized conditions was revealed by transmission electron microscopy analysis. More importantly, the crystal structure and orientation of GaN grown on SiO2 are the same as that of GaN grown on conventional sapphire substrate when a buffer layer is used. This work can aid in the development of transferable devices using GaN films.

  8. Laser annealing heals radiation damage in avalanche photodiodes

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Jin Gyu [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); University of Waterloo, Department of Electrical and Computer Engineering, Waterloo, ON (Canada); Anisimova, Elena; Higgins, Brendon L.; Bourgoin, Jean-Philippe [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); University of Waterloo, Department of Physics and Astronomy, Waterloo, ON (Canada); Jennewein, Thomas [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); University of Waterloo, Department of Physics and Astronomy, Waterloo, ON (Canada); Canadian Institute for Advanced Research, Quantum Information Science Program, Toronto, ON (Canada); Makarov, Vadim [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); University of Waterloo, Department of Electrical and Computer Engineering, Waterloo, ON (Canada); University of Waterloo, Department of Physics and Astronomy, Waterloo, ON (Canada)

    2017-12-15

    Avalanche photodiodes (APDs) are a practical option for space-based quantum communications requiring single-photon detection. However, radiation damage to APDs significantly increases their dark count rates and thus reduces their useful lifetimes in orbit. We show that high-power laser annealing of irradiated APDs of three different models (Excelitas C30902SH, Excelitas SLiK, and Laser Components SAP500S2) heals the radiation damage and several APDs are restored to typical pre-radiation dark count rates. Of nine samples we test, six APDs were thermally annealed in a previous experiment as another solution to mitigate the radiation damage. Laser annealing reduces the dark count rates further in all samples with the maximum dark count rate reduction factor varying between 5.3 and 758 when operating at -80 C. This indicates that laser annealing is a more effective method than thermal annealing. The illumination power to reach these reduction factors ranges from 0.8 to 1.6 W. Other photon detection characteristics, such as photon detection efficiency, timing jitter, and afterpulsing probability, fluctuate but the overall performance of quantum communications should be largely unaffected by these variations. These results herald a promising method to extend the lifetime of a quantum satellite equipped with APDs. (orig.)

  9. Amplified Self-replication of DNA Origami Nanostructures through Multi-cycle Fast-annealing Process

    Science.gov (United States)

    Zhou, Feng; Zhuo, Rebecca; He, Xiaojin; Sha, Ruojie; Seeman, Nadrian; Chaikin, Paul

    We have developed a non-biological self-replication process using templated reversible association of components and irreversible linking with annealing and UV cycles. The current method requires a long annealing time, up to several days, to achieve the specific self-assembly of DNA nanostructures. In this work, we accomplished the self-replication with a shorter time and smaller replication rate per cycle. By decreasing the ramping time, we obtained the comparable replication yield within 90 min. Systematic studies show that the temperature and annealing time play essential roles in the self-replication process. In this manner, we can amplify the self-replication process to a factor of 20 by increasing the number of cycles within the same amount of time.

  10. Effects of annealing on evaporated SnS thin films

    International Nuclear Information System (INIS)

    Samsudi Sakrani; Bakar Ismail

    1994-01-01

    The effects of annealing of evaporated tin sulphide thin films (SnS) are described. The films were initially deposited onto glass substrate, followed by annealing in an encapsulated carbon block under the running argon gas at 310 degree Celsius. Short time annealing of the films results in a slight change of the compositions to a mix SnS/SnS sub 2 compound, and the tendency of increasing SnS sub 2 formation was observed on the films annealed for longer periods up to 20 hours. X-ray results showed the transformation of SnS peaks (040) and (080) to predominantly SnS sub 2 peaks - (001), (100), (101), and (110). The associated absorption coefficients measured on the films were found to be greater than 10 sup 5 cm sup -1, with indication of higher photon energy leading to the formation of SnS sub 2 compound

  11. Effects of annealing on evaporated SnS thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sakrani, Samsudi; Ismail, Bakar [Universiti Teknologi Malaysia, Skudai, Johor Bahru (Malaysia). Dept. of Physics

    1994-12-31

    The effects of annealing of evaporated tin sulphide thin films (SnS) are described. The films were initially deposited onto glass substrate, followed by annealing in an encapsulated carbon block under the running argon gas at 310 degree Celsius. Short time annealing of the films results in a slight change of the compositions to a mix SnS/SnS sub 2 compound, and the tendency of increasing SnS sub 2 formation was observed on the films annealed for longer periods up to 20 hours. X-ray results showed the transformation of SnS peaks (040) and (080) to predominantly SnS sub 2 peaks - (001), (100), (101), and (110). The associated absorption coefficients measured on the films were found to be greater than 10 sup 5 cm sup -1, with indication of higher photon energy leading to the formation of SnS sub 2 compound.

  12. Traffic Flow Optimization Using a Quantum Annealer

    Directory of Open Access Journals (Sweden)

    Florian Neukart

    2017-12-01

    Full Text Available Quantum annealing algorithms belong to the class of metaheuristic tools, applicable for solving binary optimization problems. Hardware implementations of quantum annealing, such as the quantum processing units (QPUs produced by D-Wave Systems, have been subject to multiple analyses in research, with the aim of characterizing the technology’s usefulness for optimization and sampling tasks. In this paper, we present a real-world application that uses quantum technologies. Specifically, we show how to map certain parts of a real-world traffic flow optimization problem to be suitable for quantum annealing. We show that time-critical optimization tasks, such as continuous redistribution of position data for cars in dense road networks, are suitable candidates for quantum computing. Due to the limited size and connectivity of current-generation D-Wave QPUs, we use a hybrid quantum and classical approach to solve the traffic flow problem.

  13. Raman Spectroscopy Study of Annealing-Induced Effects on Graphene Prepared by Micromechanical Exfoliation

    International Nuclear Information System (INIS)

    Song, Ji Eun; Ko, Taeg Yeoung; Ryu, Sun Min

    2010-01-01

    Raman spectroscopy was combined with AFM to investigate the effects of thermal annealing on the graphene samples prepared by the widely used micromechanical exfoliation method. Following annealing cycles, adhesive residues were shown to contaminate graphene sheets with thin molecular layers in their close vicinity causing several new intense Raman bands. Detailed investigation shows that the Raman scattering is very strong and may be enhanced by the interaction with graphene. Although the current study does not pinpoint detailed origins for the new Raman bands, the presented results stress that graphene prepared by the above method may require extra cautions when treated with heat or possibly solvents. Since its isolation from graphite, graphene has drawn a lot of experimental and theoretical research. These efforts have been mostly in pursuit of various applications such as electronics, sensors, stretchable transparent electrodes, and various composite materials. To accomplish such graphene-based applications, understanding chemical interactions of this new material with environments during various processing treatments will become more important. Since thermal annealing is widely used in various research of graphene for varying purposes such as cleaning, nanostructuring, reactions, etc., understanding annealing-induced effects is prerequisite to many fundamental studies of graphene. In this regard, it is to be noted that there has been a controversy on the cause of the annealing-induced hole doping in graphene

  14. Effect of annealing and UV-radiation time over micropore architecture of self-assembled block copolymer thin film

    Directory of Open Access Journals (Sweden)

    G. del C. Pizarro

    2015-06-01

    Full Text Available Block copolymers have been recognized as versatile materials to prepare nanoporous polymer films or membranes, but their potential has not been completely explored. This study focuses on the formation and characterization of nanoporous polymer films based on poly(styrene-block-(methylmethacrylate/methacrylic acid; (PS-b-MMA/MAA were obtained through atom transfer radical polymerization (ATRP, by using two different protocols: annealing and annealingirradiation; for improving the formation of microporous surface. The composition, crystallinity and structural order of the films were studied by Raman spectroscopy. The film polymer thickness was obtained through very high resolution ellipsometry (VHRE. Finally, atomic force microcopy (AFM and scanning electron microscopy (SEM techniques were used to detect changes in the porous-structure. These results show that the morphological properties of the block copolymer were affected via the modification of two variables, UV-radiation time and annealing. SEM and AFM micrographs showed that the morphology exhibit a porous ordered structure. Contact angle measurement suggests additional interactions between hydrophilic functional groups that influence the film wettability.

  15. Computational algorithm for molybdenite concentrate annealing

    International Nuclear Information System (INIS)

    Alkatseva, V.M.

    1995-01-01

    Computational algorithm is presented for annealing of molybdenite concentrate with granulated return dust and that of granulated molybdenite concentrate. The algorithm differs from the known analogies for sulphide raw material annealing by including the calculation of return dust mass in stationary annealing; the latter quantity varies form the return dust mass value obtained in the first iteration step. Masses of solid products are determined by distribution of concentrate annealing products, including return dust and benthonite. The algorithm is applied to computations for annealing of other sulphide materials. 3 refs

  16. Annealing Induced Softening in Deformed AI-4043 Alloy

    International Nuclear Information System (INIS)

    Saad, G.; Fawzy, A.; Soliman, H.N.; Mohammed, Gh.; Fayek, S.A.

    2011-01-01

    The present paper is devoted to study the effect of annealing temperature for different annealing periods of time on the structure and consequently on the tensile properties of Al-4043 alloy. The obtained results showed that the microstructure of AI-4043 alloy is characterized by the presence of spherically shaped Si-particles, which were found to be uniformly distributed within the AI-matrix. Stress-strain characterizations of AI-4043 samples annealed at different temperatures (T a = 573, 673 and 773 K) for different periods of time (t a = 0.5, 1,2.5,5 and 10 h), showed that the tensile parameters; yield stress ε y 0.2 and fracture stress ε f were decreased with increasing Ta and/or ta while the total strain ε T was increased. This was interpreted in terms of growth of Si-particles with increasing T a and/or t a . Attention has been also paid to the role of the minor elements Fe, Cu and Ti on the structure and tensile response behavior of the alloy under investigation

  17. Tailoring of magnetoimpedance effect and magnetic softness of Fe-rich glass-coated microwires by stress- annealing.

    Science.gov (United States)

    Zhukova, V; Blanco, J M; Ipatov, M; Churyukanova, M; Taskaev, S; Zhukov, A

    2018-02-16

    There is a pressing need for improving of the high-frequency magneto-impedance effect of cost-effective soft magnetic materials for use in high-performance sensing devices. The impact of the stress-annealing on magnetic properties and high frequency impedance of Fe-rich glass-coated microwires was studied. Hysteresis loops of Fe-rich microwires have been considerably affected by stress- annealing. In stress-annealed Fe- rich microwire we obtained drastic decreasing of coercivity and change of character of hysteresis loop from rectangular to linear. By controlling stress-annealing conditions (temperature and time) we achieved drastic increasing (by order of magnitude) of giant magnetoimpedance ratio. Coercivity, remanent magnetization, diagonal and of-diagonal magnetoimpedance effect of Fe-rich microwires can be tuned by stress-annealing conditions: annealing temperature and time. Observed experimental results are discussed considering relaxation of internal stresses, compressive "back-stresses" arising after stress annealing and topological short range ordering.

  18. Matrix isolation infrared spectra of O2 and N2 insertion reactions with atomic uranium

    International Nuclear Information System (INIS)

    Hunt, R.D.; Toth, L.M.; Yustein, J.T.; Andrews, L.

    1993-01-01

    Laser ablation of refractory metals can be an effective source of vapor for matrix isolation IR studies. This combination of techniques was used for the first time to study the mechanisms of U vapor reactions with atmospheric components. U atoms and O 2 were codeposited with excess Ar at 12 K. The dominant codeposition products were UO 2 and UO 3 . In contrast, the UO yield was always small because UO 2 is formed by an insertion mechanism. This mechanism was verified in the 16 O 2 / 18 O 2 experiments which failed to produce 16 OU 18 O. The effects of UV photolysis and matrix annealings were also examined. The U atoms and O 2 reaction requires little or no activation energy since UO 2 was formed from cold reagents. New charge-transfer species, (UO 2+ 2 )(O 2- 2 ) and (UO + 2 )(O - 2 ), and a weak complex, UO 3 --O 2 , were primarily produced under conditions which favored further O 2 reactions. Similar U atom and N 2 experiments produced only linear NUN which is also produced by an insertion mechanism. This U reaction represents the first time that atom was observed breaking and inserting into the triple bond of N 2 . Photolysis dramatically increased the NUN yield by 3-fold. Matrix annealings produced weak UN 2 --N 2 and UN 2 --2N 2 complexes

  19. Matrix isolation infrared spectra of O2 and N2 insertion reactions with atomic uranium

    Science.gov (United States)

    Hunt, Rodney D.; Toth, L. Mac; Yustein, Jason T.; Andrews, Lester

    1993-10-01

    Laser ablation of refractory metals can be an effective source of vapor for matrix isolation IR studies. This combination of techniques was used for the first time to study the mechanisms of U vapor reactions with atmospheric components. U atoms and O2 were codeposited with excess Ar at 12 K. The dominant codeposition products were UO2 and UO3. In contrast, the UO yield was always small because UO2 is formed by an insertion mechanism. This mechanism was verified in the 16O2/18O2 experiments which failed to produce 16OU18O. The effects of UV photolysis and matrix annealings were also examined. The U atoms and O2 reaction requires little or no activation energy since UO2 was formed from cold reagents. New charge-transfer species, (UO2+2)(O2-2) and (UO+2)(O-2), and a weak complex, UO3-O2, were primarily produced under conditions which favored further O2 reactions. Similar U atom and N2 experiments produced only linear NUN which is also produced by an insertion mechanism. This U reaction represents the first time that atom was observed breaking and inserting into the triple bond of N2. Photolysis dramatically increased the NUN yield by 3-fold. Matrix annealings produced weak UN2-N2 and UN2-2N2 complexes.

  20. Detection of Toxoplasma gondii and Epstein-Barr virus in HIV patients with clinical symptoms of suspected central nervous system infection using duplex real-time polymerase chain reaction

    Science.gov (United States)

    Rahmawati, E.; Ibrahim, F.; Imran, D.; Sudarmono, P.

    2017-08-01

    Focal brain lesion is a neurological complication in HIV, which is marked as a space occupying lesion (SOL) and needs rapid and effective treatment. This lesion is mainly caused by encephalitis toxoplasma and primary central nervous system lymphoma related to the Epstein-Barr virus (EBV) infection, which is difficult to distinguish using CT scan or magnetic resonance imaging (MRI). The gold standard of diagnosing focal brain lesion has been brain biopsy, but this examination is an invasive procedure that causes complications. The objective of this study is to obtain the rapid laboratory diagnosis of Toxoplasma gondii (T. gondii) and EBV infection. In this experimental study, blood and cerebrospinal fluid were obtained from HIV patients who were admitted to the Neurology Department of Cipto Mangunkusumo Hospital. The samples were examined using duplex real-time polymerase chain reaction (PCR) to detect T. gondii and EBV. The first step was the optimization of duplex real-time PCR, including the annealing temperature, primer and probe concentration, elution volume, and template volume. Minimal DNA detection was used to measure minimal T. gondii and EBV. Cross reactions were determined for technical specificity using the bacteria and viruses Staphylococcus aureus, Klebsiella pneumonia, Pseudomonas aeruginosa, Mycobacterium tuberculosis H37Rv, Candida spp, cytomegalovirus, herpes zoster virus, and varicella zoster virus. Duplex real-time PCR was applied optimally to patients. In the optimization of duplex real-time PCR, the annealing temperature of T. gondii and EBV were 58 °C, the concentration of primer forward and reverse for T. gondii and EBV were 0.2 μM, the concentration of probe for T. gondii and EBV were 0.4μM and 0.2 μM, respectively. Minimal DNA detection of T. gondii and EBV were 5.68 copy/ml and 1.31 copy/ml, respectively. There was no cross reaction between another bacteria and virus that were used as the primer and probe for T. gondii and EBV. The

  1. Effect of tensile stress on the annealed structure of a metallic glass

    International Nuclear Information System (INIS)

    Vianco, P.T.; Li, J.C.M.

    1987-01-01

    The low-temperature (120 0 --245 0 C) structural relaxation of Metglas/sup R/ 2826B (Ni 49 Fe 29 P 14 B 6 Si 2 ) amorphous alloy was investigated for samples subjected to a tensile stress in the range of 20--400 MPa during annealing. The stress-annealed samples demonstrated a much smaller increase of microhardness than was observed in similarly annealed ribbons without a stress. Further heat treatment of the stress-annealed specimens, this time without the stress, was capable of increasing the microhardnesses of only some ribbons to values equal to those of samples similarly heat treated initially without a stress. An additional exothermic peak in the differential scanning calorimetry (DSC) thermograms of the stress-annealed specimens indicated the presence of a more disordered structure at room temperature, which was found to correlate with the lower microhardness values. Otherwise, those artifacts of the DSC thermograms that were characteristic of samples annealed without a stress were still present in the stress-annealed ribbons. No effect on the crystallization temperature was noted but the glass transition temperature was increased in the stress-annealed case with respect to values attained when the stress was absent during heat treatment. A reduction in the degree of embrittlement of those samples annealed with a tensile stress was a further indication of more disorder in the stress-annealed ribbons

  2. The annealing of radiation damage in type Ia diamond

    International Nuclear Information System (INIS)

    Collins, Alan T; Kiflawi, Isaac

    2009-01-01

    The kinetics of the recovery of radiation damage in type Ia diamond has been investigated using isothermal annealing at 600 deg. C. In diamonds having a reasonably homogeneous distribution of nitrogen the decay of the vacancy concentration with time can be approximately described by a single exponential. Previous investigations have identified 'fast' and 'slow' components in the annealing, and we show that the existence of more than one time constant is associated with inhomogeneous nitrogen concentrations. The measurements show further that, in order to obtain the oscillator strengths of nitrogen-vacancy centres, studies must be restricted to diamonds with moderately high nitrogen concentrations.

  3. Semiconductor annealing

    International Nuclear Information System (INIS)

    Young, J.M.; Scovell, P.D.

    1981-01-01

    A process for annealing crystal damage in ion implanted semiconductor devices is described in which the device is rapidly heated to a temperature between 450 and 600 0 C and allowed to cool. It has been found that such heating of the device to these relatively low temperatures results in rapid annealing. In one application the device may be heated on a graphite element mounted between electrodes in an inert atmosphere in a chamber. The process may be enhanced by the application of optical radiation from a Xenon lamp. (author)

  4. Control of O-H bonds at a-IGZO/SiO2 interface by long time thermal annealing for highly stable oxide TFT

    Directory of Open Access Journals (Sweden)

    Jae Kwon Jeon

    2017-12-01

    Full Text Available We report two-step annealing, high temperature and sequent low temperature, for amorphous indium-gallium-zinc-oxide (a-IGZO thin-film transistor (TFT to improve its stability and device performance. The annealing is carried out at 300 oC in N2 ambient for 1 h (1st step annealing and then at 250 oC in vacuum for 10 h (2nd step annealing. It is found that the threshold voltage (VTH changes from 0.4 V to -2.0 V by the 1st step annealing and to +0.6 V by 2nd step annealing. The mobility changes from 18 cm2V-1s-1 to 25 cm2V-1s-1 by 1st step and decreases to 20 cm2V-1s-1 by 2nd step annealing. The VTH shift by positive bias temperature stress (PBTS is 3.7 V for the as-prepared TFT, and 1.7 V for the 1st step annealed TFT, and 1.3 V for the 2nd step annealed TFT. The XPS (X-ray photoelectron spectroscopy depth analysis indicates that the reduction in O-H bonds at the top interface (SiO2/a-IGZO by 2nd step annealing appears, which is related to the positive VTH shift and smaller VTH shift by PBTS.

  5. Control of O-H bonds at a-IGZO/SiO2 interface by long time thermal annealing for highly stable oxide TFT

    Science.gov (United States)

    Jeon, Jae Kwon; Um, Jae Gwang; Lee, Suhui; Jang, Jin

    2017-12-01

    We report two-step annealing, high temperature and sequent low temperature, for amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistor (TFT) to improve its stability and device performance. The annealing is carried out at 300 oC in N2 ambient for 1 h (1st step annealing) and then at 250 oC in vacuum for 10 h (2nd step annealing). It is found that the threshold voltage (VTH) changes from 0.4 V to -2.0 V by the 1st step annealing and to +0.6 V by 2nd step annealing. The mobility changes from 18 cm2V-1s-1 to 25 cm2V-1s-1 by 1st step and decreases to 20 cm2V-1s-1 by 2nd step annealing. The VTH shift by positive bias temperature stress (PBTS) is 3.7 V for the as-prepared TFT, and 1.7 V for the 1st step annealed TFT, and 1.3 V for the 2nd step annealed TFT. The XPS (X-ray photoelectron spectroscopy) depth analysis indicates that the reduction in O-H bonds at the top interface (SiO2/a-IGZO) by 2nd step annealing appears, which is related to the positive VTH shift and smaller VTH shift by PBTS.

  6. Thermally multiplexed polymerase chain reaction.

    Science.gov (United States)

    Phaneuf, Christopher R; Pak, Nikita; Saunders, D Curtis; Holst, Gregory L; Birjiniuk, Joav; Nagpal, Nikita; Culpepper, Stephen; Popler, Emily; Shane, Andi L; Jerris, Robert; Forest, Craig R

    2015-07-01

    Amplification of multiple unique genetic targets using the polymerase chain reaction (PCR) is commonly required in molecular biology laboratories. Such reactions are typically performed either serially or by multiplex PCR. Serial reactions are time consuming, and multiplex PCR, while powerful and widely used, can be prone to amplification bias, PCR drift, and primer-primer interactions. We present a new thermocycling method, termed thermal multiplexing, in which a single heat source is uniformly distributed and selectively modulated for independent temperature control of an array of PCR reactions. Thermal multiplexing allows amplification of multiple targets simultaneously-each reaction segregated and performed at optimal conditions. We demonstrate the method using a microfluidic system consisting of an infrared laser thermocycler, a polymer microchip featuring 1 μl, oil-encapsulated reactions, and closed-loop pulse-width modulation control. Heat transfer modeling is used to characterize thermal performance limitations of the system. We validate the model and perform two reactions simultaneously with widely varying annealing temperatures (48 °C and 68 °C), demonstrating excellent amplification. In addition, to demonstrate microfluidic infrared PCR using clinical specimens, we successfully amplified and detected both influenza A and B from human nasopharyngeal swabs. Thermal multiplexing is scalable and applicable to challenges such as pathogen detection where patients presenting non-specific symptoms need to be efficiently screened across a viral or bacterial panel.

  7. Mechanical behavior of multipass welded joint during stress relief annealing

    International Nuclear Information System (INIS)

    Ueda, Yukio; Fukuda, Keiji; Nakacho, Keiji; Takahashi, Eiji; Sakamoto, Koichi.

    1978-01-01

    An investigation into mechanical behavior of a multipass welded joint of a pressure vessel during stress relief annealing was conducted. The study was performed theoretically and experimentally on idealized research models. In the theoretical analysis, the thermal elastic-plastic creep theory developed by the authors was applied. The behavior of multipass welded joints during the entire thermal cycle, from welding to stress relief annealing, was consistently analyzed by this theory. The results of the analysis show a good, fundamentally coincidence with the experimental findings. The outline of the results and conclusions is as follows. (1) In the case of the material (2 1/4Cr-1Mo steel) furnished in this study, the creep strain rate during stress relief annealing below 575 0 C obeys the strain-hardening creep law using the transient creep and the one above 575 0 C obeys the power creep law using the stational creep. (2) In the transverse residual stress (σsub(x)) distribution after annealing, the location of the largest tensile stress on the top surface is about 15 mm away from the toe of weld, and the largest at the cross section is just below the finishing bead. These features are similar to those of welding residual stresses. But the stress distribution after annealing is smoother than one from welding. (3) The effectiveness of stress relief annealing depends greatly on the annealing temperature. For example, most of residual stresses are relieved at the heating stage with a heating rate of 30 0 C/hr. to 100 0 C/hr. if the annealing temperature is 650 0 C, but if the annealing temperature is 550 0 C, the annealing is not effective even with a longer holding time. (4) In the case of multipass welding residual stresses studied in this paper, the behaviors of high stresses during annealing are approximated by ones during anisothermal relaxation. (auth.)

  8. Processes in N-channel MOSFETs during postirradiation thermal annealing

    International Nuclear Information System (INIS)

    Pejovic, M.; Jaksic, A.; Ristic, G.; Baljosevic, B.

    1997-01-01

    The processes during postirradiation thermal annealing of γ-ray irradiated n-channel MOSFETs with both wet and dry gate oxides are investigated. For both analysed technologies, a so-called ''latent'' interface trap buildup is observed, followed at very late annealing times by the decrease in the interface-trap density. A model is proposed that successfully accounts for the experimental results. Implications of observed effects for total dose hardness assurance test methods implementation are discussed. (author)

  9. Management of the Bohunice RPVs annealing procedures

    International Nuclear Information System (INIS)

    Repka, M.

    1994-01-01

    The program of annealing regeneration procedure of RPVs units 1 and 2 of NPP V-1 (EBO) realization in the year 1993, is the topic of this paper. In the paper the following steps are described in detail: the preparation works, the annealing procedure realization schedule and safety management: starting with zero conditions, assembling of annealing apparatus, annealing procedure, cooling down and disassembling procedure of annealing apparatus. At the end the programs of annealing of both RPVs including the dosimetry measurements are discussed and evaluated. (author). 3 figs

  10. Effect Of Low-Temperature Annealing On The Properties Of Ni-P Amorphous Alloys Deposited Via Electroless Plating

    Directory of Open Access Journals (Sweden)

    Zhao Guanlin

    2015-06-01

    Full Text Available Amorphous Ni-P alloys were prepared via electroless plating and annealing at 200°C at different times to obtain different microstructures. The effects of low-temperature annealing on the properties of amorphous Ni-P alloys were studied. The local atomic structure of the annealed amorphous Ni-P alloys was analyzed by calculating the atomic pair distribution function from their X-ray diffraction patterns. The results indicate that the properties of the annealed amorphous Ni-P alloys are closely related to the order atomic cluster size. However, these annealed Ni-P alloys maintained their amorphous structure at different annealing times. The variation in microhardness is in agreement with the change in cluster size. By contrast, the corrosion resistance of the annealed alloys in 3.5 wt% NaCl solution increases with the decrease in order cluster size.

  11. Influence of oxygen on the annealing of radioactive defects in germanium

    International Nuclear Information System (INIS)

    Gasimov, G.M.; Mustafayev, Yn.M.; Gasimova, V.G.

    2002-01-01

    The isochronal annealing were carried out in the wide temperature range, for the establishment of oxygen influence on the annealing of radioactive defects (Rd) in any radiated germanium samples, concentrated with oxygen up to concentration of 9.7·10 16 cm -3 . It is shown that the curves of isochronal annealing of one of the such samples 1, with primary current charge concentration of 9.0·10 cm 14 , radiated by integral electron flow of φ= 8.0·10 16 cm -3 , at 293 K and also the non-oxygen samples 2, with primary concentration of 1.7·10 cm -3 , radiated at above mentioned conditions. The sample 1 is converted by radiation to p-type, but the conversion not occur in samples 2. It is illustrated, that that there is two annealing stage at 340-430 K, for the samples 2, which in results takes place the complete annealing of the RD. At 300 K the annealing takes place in samples of 1, but at 340 K - the reverse annealing of RD. The sample was at compensated state in the temperature range of 360-400 K. An annealing of RD takes place again at 440 K and the sample re-converted its conductivity type. The reverse annealing at 480 K, and at about 510 K, the substantial annealing of the defects has been observed, which in results a sample restores it's primary parameters. The carried out experiments show that as in converted, and also in n-type be samples, Is observed the reverse annealing of RD, but the reverse annealing of current charge carriers in n-type samples is observed only at such conditions, of the integral flow of accelerated elections exceeds the primary concentration of current charge carriers about 4 time of magnitude (φ≥4n 0 ). Besides, the complete annealing of RD in germanium samples concentrated with oxygen, takes place at more high temperatures in comparison with the non-oxygen samples

  12. Comparison of Sprint Reaction and Visual Reaction Times of Athletes in Different Branches

    Science.gov (United States)

    Akyüz, Murat; Uzaldi, Basar Basri; Akyüz, Öznur; Dogru, Yeliz

    2017-01-01

    The aims of this study are to analyse sprint reaction and visual reaction times of female athletes of different branches competing in Professional leagues and to show the differences between them. 42 voluntary female athletes from various branches of Professional leagues of Istanbul (volleyball, basketball, handball) were included in the…

  13. Comparing of the Reaction Time in Substance-Dependent and Non-Dependent Individuals

    Directory of Open Access Journals (Sweden)

    Mohammad Narimani

    2012-11-01

    Full Text Available Aim: The aim of this study was to compare the simple, selective, and discrimination reaction time in substance-dependent and non-dependent individuals. Method: In this causal-comparative study, the population included of 425 males (opium and crystal dependents who were referred to addiction rehabilitation centers in Tabriz. By random sampling, 16 opium dependents, 16 crystal dependents, and 16 non-dependent individuals with no history of dependency as the compare group were selected. All groups peered in age, and marital status. For gathering data, “Addicts Admit Questionnaire” and laboratory device known as the "Reaction Time Assay" have been used. Results: The results of this study showed that there are significant differences among all groups in simple reaction time, choice reaction time and reaction time to auditory stimuli, but no significant difference in discrimination reaction time and reaction time to visual stimulus observed. Conclusion: The reaction time of substance-dependent groups is slower than non-dependent groups.

  14. ACTIVITY-BASED COSTING DAN SIMULATED ANNEALING UNTUK PENCARIAN RUTE PADA FLEXIBLE MANUFACTURING SYSTEMS

    Directory of Open Access Journals (Sweden)

    Gregorius Satia Budhi

    2003-01-01

    Full Text Available Flexible Manufacturing System (FMS is a manufacturing system that is formed from several Numerical Controlled Machines combine with material handling system, so that different jobs can be worked by different machines sequences. FMS combine the high productivity and flexibility of Transfer Line and Job Shop manufacturing system. In this reasearch, Activity-Based Costing(ABC approach was used as the weight to search the operation route in the proper machine, so that the total production cost can be optimized. The search method that was used in this experiment is Simulated Annealling, a variant form Hill Climbing Search method. An ideal operation time to proses a part was used as the annealling schedule. From the empirical test, it could be proved that the use of ABC approach and Simulated Annealing to search the route (routing process can optimize the Total Production Cost. In the other hand, the use of ideal operation time to process a part as annealing schedule can control the processing time well. Abstract in Bahasa Indonesia : Flexible Manufacturing System (FMS adalah sistem manufaktur yang tersusun dari mesin-mesin Numerical Control (NC yang dikombinasi dengan Sistem Penanganan Material, sehingga job-job berbeda dikerjakan oleh mesin-mesin dengan alur yang berlainan. FMS menggabungkan produktifitas dan fleksibilitas yang tinggi dari Sistem Manufaktur Transfer Line dan Job Shop. Pada riset ini pendekatan Activity-Based Costing (ABC digunakan sebagai bobot / weight dalam pencarian rute operasi pada mesin yang tepat, untuk lebih mengoptimasi biaya produksi secara keseluruhan. Adapun metode Searching yang digunakan adalah Simulated Annealing yang merupakan varian dari metode searching Hill Climbing. Waktu operasi ideal untuk memproses sebuah part digunakan sebagai Annealing Schedulenya. Dari hasil pengujian empiris dapat dibuktikan bahwa penggunaan pendekatan ABC dan Simulated Annealing untuk proses pencarian rute (routing dapat lebih

  15. Dependence of annealing time on structural and morphological properties of Ca(Zr0.05Ti0.95)O3 thin films

    International Nuclear Information System (INIS)

    Cavalcante, L.S.; Simoes, A.Z.; Orlandi, M.O.; Santos, M.R.M.C.; Varela, J.A.; Longo, E.

    2008-01-01

    Ca(Zr 0.05 Ti 0.95 )O 3 (CZT) thin films were prepared by the polymeric precursor method by spin-coating process. The films were deposited on Pt(1 1 1)/Ti/SiO 2 /Si(1 0 0) substrates and annealed at 650 deg. C for 2, 4, and 6 h in oxygen atmosphere. Structure and morphology of the CZT thin films were characterized by the X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM) and field-emission scanning electron microscopy (FEG-SEM). XRD revealed that the film is free of secondary phases and crystallizes in the orthorhombic structure. The annealing time influences the grain size, lattices parameter and in the film thickness

  16. On the analysis of the activation mechanisms of sub-melt laser anneals

    DEFF Research Database (Denmark)

    Clarysse, T.; Bogdanowicz, J.; Goosens, J.

    2008-01-01

    electrically active concentration level as well as the concurrent mobility is dependent on the dopant concentration level. This implies that the activation of B through the laser anneal process in the explored temperature–time space is governed by kinetic processes (i.e. the dissolution of B–I pairs......In order to fabricate carrier profiles with a junction depth (15 nm) and sheet resistance value suited for sub-32 nm Si-CMOS technology, the usage of sub-melt laser anneal is a promising route to explore. As laser annealed junctions seem to outperform standard anneal approaches, a detailed......) and not by the (temperature related) solid solubility....

  17. Annealing effect on the performance of RuO{sub 2}-Ta{sub 2}O{sub 5}/Ti electrodes for use in supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ho-Rei; Lai, Huen-Hua [Department of Chemical and Materials Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung, 80782 Taiwan (China); Jow, Jiin-Jiang, E-mail: jjjow@cc.kuas.edu.tw [Department of Chemical and Materials Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung, 80782 Taiwan (China)

    2011-02-15

    The preparation of RuO{sub 2}-Ta{sub 2}O{sub 5}/Ti electrodes, by dip-coating, for use in supercapacitors was investigated. The stability and specific capacitance of the electrodes annealed at various temperatures was examined. The results show that highly stable electrodes with a specific capacitance of 170 F g RuO{sub 2}{sup -1} were obtained at approximately 250 deg. C, while electrodes with a lower capacitance (130 F g RuO{sub 2}{sup -1}) were obtained at 300 deg. C. The annealing time needed to obtain a stable RuO{sub 2}-Ta{sub 2}O{sub 5}/Ti electrode at various temperatures correlates well with the Arrhenius' law: with the activation energy (E) of the annealing reactions for the electrodes being estimated as 73.5 kJ mol{sup -1}. SEM images of the electrodes show the coating films to have rough surface morphology with cracks 2-6 {mu}m in width. XRD data indicate that the coating films obtained are composed of crystalline RuO{sub 2} and amorphous tantalum oxide.

  18. Placement by thermodynamic simulated annealing

    International Nuclear Information System (INIS)

    Vicente, Juan de; Lanchares, Juan; Hermida, Roman

    2003-01-01

    Combinatorial optimization problems arise in different fields of science and engineering. There exist some general techniques coping with these problems such as simulated annealing (SA). In spite of SA success, it usually requires costly experimental studies in fine tuning the most suitable annealing schedule. In this Letter, the classical integrated circuit placement problem is faced by Thermodynamic Simulated Annealing (TSA). TSA provides a new annealing schedule derived from thermodynamic laws. Unlike SA, temperature in TSA is free to evolve and its value is continuously updated from the variation of state functions as the internal energy and entropy. Thereby, TSA achieves the high quality results of SA while providing interesting adaptive features

  19. Modernizing quantum annealing using local searches

    International Nuclear Information System (INIS)

    Chancellor, Nicholas

    2017-01-01

    I describe how real quantum annealers may be used to perform local (in state space) searches around specified states, rather than the global searches traditionally implemented in the quantum annealing algorithm (QAA). Such protocols will have numerous advantages over simple quantum annealing. By using such searches the effect of problem mis-specification can be reduced, as only energy differences between the searched states will be relevant. The QAA is an analogue of simulated annealing, a classical numerical technique which has now been superseded. Hence, I explore two strategies to use an annealer in a way which takes advantage of modern classical optimization algorithms. Specifically, I show how sequential calls to quantum annealers can be used to construct analogues of population annealing and parallel tempering which use quantum searches as subroutines. The techniques given here can be applied not only to optimization, but also to sampling. I examine the feasibility of these protocols on real devices and note that implementing such protocols should require minimal if any change to the current design of the flux qubit-based annealers by D-Wave Systems Inc. I further provide proof-of-principle numerical experiments based on quantum Monte Carlo that demonstrate simple examples of the discussed techniques. (paper)

  20. Influence of annealing time and temperature on the Fe3Al intermetallic alloys microstructure modification

    Directory of Open Access Journals (Sweden)

    K. Garbala

    2011-04-01

    Full Text Available There is an industry interesting in intermetallic alloys in recent years. There are widely possibilities to adopt this kind of materials for structural units. More expensive materials can be replaced by them. A property which limits their wider application is the low plasticity at environment and elevated temperatures. In paper the results of the thermal microstructure modification are shown. To this end, the influence of annealing time and temperature on the intermetallic phase Fe3Al grain size was investigated. The impact of these factors on micro-hardness was examined as well. It was found that these operations cause the grain size reduction and the micro-hardness decrease.

  1. Thermoluminescence of annealed and shock-loaded feldspar

    International Nuclear Information System (INIS)

    Hartmetz, C.P.

    1988-01-01

    Samples of oligoclase and bytownite were shock-loaded to a variety of pressures, and annealed for a variety of temperatures and times. The effect of Mrad doses of gamma-rays on oligoclase TL were also studied. After these treatments, thermoluminescence (TL) and X-ray diffraction (XRD) measurements were made to: (1) determine the effects of shock on terrestrial feldspar and compare with variations in the TL emission of ordinary chondrites (OCs); (2) determine if disordering in feldspar was responsible for any related changes in TL properties of OCs; (3) determine if the combined effect of shock plus annealing causes the changes in TL properties; (4) see if radiation damage from cosmic ray exposure plays a role in the TL variations; (5) examine the implications of this work to the thermal and shock histories of OCs. The lightly shock-loaded and annealed oligoclase samples have a dominant peak temperature of 120-140 C, identical to type 3.3-3.5 OCs. The heavily shocked samples dominant peak is at 230C, similar to type > 3.5 OCs . While the heavily annealed/disordered oligoclase samples have a peak at 280C, this peak is rarely observed in OCs. Radiation damage from Mrad doses of gamma-rays produced no change in peak temperature, but facilitated the shift to higher peak temperatures. The TL sensitivity of the shocked samples decreased by a factor of 25. Samples annealed at low temperatures (438-533C) showed a factor of 2 decrease in TL, but at the highest temperatures, the TL was a factor of 8 higher

  2. Ensemble annealing of complex physical systems

    OpenAIRE

    Habeck, Michael

    2015-01-01

    Algorithms for simulating complex physical systems or solving difficult optimization problems often resort to an annealing process. Rather than simulating the system at the temperature of interest, an annealing algorithm starts at a temperature that is high enough to ensure ergodicity and gradually decreases it until the destination temperature is reached. This idea is used in popular algorithms such as parallel tempering and simulated annealing. A general problem with annealing methods is th...

  3. Comparison of pulsed electron beam-annealed and pulsed ruby laser-annealed ion-implanted silicon

    International Nuclear Information System (INIS)

    Wilson, S.R.; Appleton, B.R.; White, C.W.; Narayan, J.; Greenwald, A.C.

    1978-11-01

    Recently two new techniques, pulsed electron beam annealing and pulsed laser annealing, have been developed for processing ion-implanted silicon. These two types of anneals have been compared using ion-channeling, ion back-scattering, and transmission electron microscopy (TEM). Single crystal samples were implanted with 100 keV As + ions to a dose of approx. 1 x 10 16 ions/cm 2 and subsequently annealed by either a pulsed Ruby laser or a pulsed electron beam. Our results show in both cases that the near-surface region has melted and regrown epitaxially with nearly all of the implanted As (97 to 99%) incroporated onto lattice sites. The analysis indicates that the samples are essentially defect free and have complete electrical recovery

  4. Improving ion irradiated high Tc Josephson junctions by annealing: The role of vacancy-interstitial annihilation

    International Nuclear Information System (INIS)

    Sirena, M.; Matzen, S.; Bergeal, N.; Lesueur, J.; Faini, G.; Bernard, R.; Briatico, J.; Crete, D. G.

    2007-01-01

    The authors have studied the annealing effect in the transport properties of high T c Josephson junctions (JJs) made by ion irradiation. Low temperature annealing (80 deg. C) increases the JJ coupling temperature (T J ) and the I c R n product, where I c is the critical current and R n the normal resistance. They have found that the spread in JJ characteristics can be reduced by sufficient long annealing times, increasing the reproducibility of ion irradiated Josephson junctions. The characteristic annealing time and the evolution of the spread in the JJ characteristics can be explained by a vacancy-interstitial annihilation process rather than by an oxygen diffusion one

  5. Annealing helicase HARP closes RPA-stabilized DNA bubbles non-processively.

    Science.gov (United States)

    Burnham, Daniel R; Nijholt, Bas; De Vlaminck, Iwijn; Quan, Jinhua; Yusufzai, Timur; Dekker, Cees

    2017-05-05

    We investigate the mechanistic nature of the Snf2 family protein HARP, mutations of which are responsible for Schimke immuno-osseous dysplasia. Using a single-molecule magnetic tweezers assay, we construct RPA-stabilized DNA bubbles within torsionally constrained DNA to investigate the annealing action of HARP on a physiologically relevant substrate. We find that HARP closes RPA-stabilized bubbles in a slow reaction, taking on the order of tens of minutes for ∼600 bp of DNA to be re-annealed. The data indicate that DNA re-anneals through the removal of RPA, which is observed as clear steps in the bubble-closing traces. The dependence of the closing rate on both ionic strength and HARP concentration indicates that removal of RPA occurs via an association-dissociation mechanism where HARP does not remain associated with the DNA. The enzyme exhibits classical Michaelis-Menten kinetics and acts cooperatively with a Hill coefficient of 3 ± 1. Our work also allows the determination of some important features of RPA-bubble structures at low supercoiling, including the existence of multiple bubbles and that RPA molecules are mis-registered on the two strands. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  6. Far-infrared spectroscopy of thermally annealed tungsten silicide films

    International Nuclear Information System (INIS)

    Amiotti, M.; Borghesi, A.; Guizzetti, G.; Nava, F.; Santoro, G.

    1991-01-01

    The far-infrared transmittance spectrum of tungsten silicide has been observed for the first time. WSi 2 polycrystalline films were prepared by coevaporation and chemical-vapour deposition on silicon wafers, and subsequently thermally annealed at different temperatures. The observed structures are interpreted, on the basis of the symmetry properties of the crystal, such as infrared-active vibrational modes. Moreover, the marked lineshape dependence on annealing temperature enables this technique to analyse the formation of the solid silicide phases

  7. Remarkable changes in interface O vacancy and metal-oxide bonds in amorphous indium-gallium-zinc-oxide thin-film transistors by long time annealing at 250 °C

    International Nuclear Information System (INIS)

    Chowdhury, Md Delwar Hossain; Um, Jae Gwang; Jang, Jin

    2014-01-01

    We have studied the effect of long time post-fabrication annealing on negative bias illumination stress (NBIS) of amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film-transistors. Annealing for 100 h at 250 °C increased the field effect mobility from 14.7 cm 2 /V s to 17.9 cm 2 /V s and reduced the NBIS instability remarkably. Using X-ray photoelectron spectroscopy, the oxygen vacancy and OH were found to exist at the interfaces of a-IGZO with top and bottom SiO 2 . Long time annealing helps to decrease the vacancy concentration and increase the metal-oxygen bonds at the interfaces; this leads to increase in the free carrier concentrations in a-IGZO and field-effect mobility. X-ray reflectivity measurement indicated the increment of a-IGZO film density of 5.63 g cm −3 to 5.83 g cm −3 (3.4% increase) by 100 h annealing at 250 °C. The increase in film density reveals the decrease of O vacancy concentration and reduction of weak metal-oxygen bonds in a-IGZO, which substantially helps to improve the NBIS stability

  8. Reaction paths based on mean first-passage times

    International Nuclear Information System (INIS)

    Park, Sanghyun; Sener, Melih K.; Lu Deyu; Schulten, Klaus

    2003-01-01

    Finding representative reaction pathways is important for understanding the mechanism of molecular processes. We propose a new approach for constructing reaction paths based on mean first-passage times. This approach incorporates information about all possible reaction events as well as the effect of temperature. As an application of this method, we study representative pathways of excitation migration in a photosynthetic light-harvesting complex, photosystem I. The paths thus computed provide a complete, yet distilled, representation of the kinetic flow of excitation toward the reaction center, thereby succinctly characterizing the function of the system

  9. Effects of annealing on the physical properties of therapeutic proteins during freeze drying process.

    Science.gov (United States)

    Lim, Jun Yeul; Lim, Dae Gon; Kim, Ki Hyun; Park, Sang-Koo; Jeong, Seong Hoon

    2018-02-01

    Effects of annealing steps during the freeze drying process on etanercept, model protein, were evaluated using various analytical methods. The annealing was introduced in three different ways depending on time and temperature. Residual water contents of dried cakes varied from 2.91% to 6.39% and decreased when the annealing step was adopted, suggesting that they are directly affected by the freeze drying methods Moreover, the samples were more homogenous when annealing was adopted. Transition temperatures of the excipients (sucrose, mannitol, and glycine) were dependent on the freeze drying steps. Size exclusion chromatography showed that monomer contents were high when annealing was adopted and also they decreased less after thermal storage at 60°C. Dynamic light scattering results exhibited that annealing can be helpful in inhibiting aggregation and that thermal storage of freeze-dried samples preferably induced fragmentation over aggregation. Shift of circular dichroism spectrum and of the contents of etanercept secondary structure was observed with different freeze drying steps and thermal storage conditions. All analytical results suggest that the physicochemical properties of etanercept formulation can differ in response to different freeze drying steps and that annealing is beneficial for maintaining stability of protein and reducing the time of freeze drying process. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Annealing effect on the reproducibility of Josephson Junctions made by ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sirena, M; Matzen, S; Bergeal, N; Lesueur, J [Laboratoire Photons Et Matiere, CNRS, ESPCI, 10 Rue Vauquelin 75231 Paris (France) (France); Faini, G [Laboratoire de Photonique et Nanostructures, Route de Nozay, 91460 Marcoussis (France) (France); Bernard, R; Briatico, J; Crete, D [UMR-CNRS/THALES, Route D128, 91767 Palaiseau (France) (France)], E-mail: martin.sirena@espci.fr

    2008-02-01

    We have studied the annealing effects on the transport properties of High Tc Josephson Junctions (JJ) made by ion irradiation. Several JJ were measured for different annealing times and the experimental data were compared to numerical simulations. We have successfully used a vacancy-interstitial annihilation mechanism to describe the evolution of the JJ coupling temperature (T{sub J}) and the homogeneity of a JJ array, related to the evolution of the defects density mean value and its distribution width. For sufficient long annealing times (t > 600 min), {delta}T{sub J} was significatively reduced. This result appears to be very encouraging for future applications where the spread in JJ characteristics has to be as low as possible.

  11. Annealing effect on the reproducibility of Josephson Junctions made by ion irradiation

    International Nuclear Information System (INIS)

    Sirena, M; Matzen, S; Bergeal, N; Lesueur, J; Faini, G; Bernard, R; Briatico, J; Crete, D

    2008-01-01

    We have studied the annealing effects on the transport properties of High Tc Josephson Junctions (JJ) made by ion irradiation. Several JJ were measured for different annealing times and the experimental data were compared to numerical simulations. We have successfully used a vacancy-interstitial annihilation mechanism to describe the evolution of the JJ coupling temperature (T J ) and the homogeneity of a JJ array, related to the evolution of the defects density mean value and its distribution width. For sufficient long annealing times (t > 600 min), ΔT J was significatively reduced. This result appears to be very encouraging for future applications where the spread in JJ characteristics has to be as low as possible

  12. Effects of (n, γ) reaction on chromium oxides (VI)

    International Nuclear Information System (INIS)

    Di Risio, Cecilia; Marques, Roberto

    1988-01-01

    A study of the behaviour of the recoil atom in irradiated CrO 3 has been performed. Irradiations were made in a nuclear reactor; post-irradiation analysis was performed using low voltage paper electrophoresis; an isothermal step annealing study was also conducted. Obtained values for rate constants and the activation energy for the annealing reaction are presented. A comparison with the behaviour reported for different chromates was performed. (Author) [es

  13. Evolution of Self-Assembled Au NPs by Controlling Annealing Temperature and Dwelling Time on Sapphire (0001).

    Science.gov (United States)

    Lee, Jihoon; Pandey, Puran; Sui, Mao; Li, Ming-Yu; Zhang, Quanzhen; Kunwar, Sundar

    2015-12-01

    Au nanoparticles (NPs) have been utilized in a wide range of device applications as well as catalysts for the fabrication of nanopores and nanowires, in which the performance of the associated devices and morphology of nanopores and nanowires are strongly dependent on the size, density, and configuration of the Au NPs. In this paper, the evolution of the self-assembled Au nanostructures and NPs on sapphire (0001) is systematically investigated with the variation of annealing temperature (AT) and dwelling time (DT). At the low-temperature range between 300 and 600 °C, three distinct regimes of the Au nanostructure configuration are observed, i.e., the vermiform-like Au piles, irregular Au nano-mounds, and Au islands. Subsequently, being provided with relatively high thermal energy between 700 and 900 °C, the round dome-shaped Au NPs are fabricated based on the Volmer-Weber growth model. With the increased AT, the size of the Au NPs is gradually increased due to a more favorable surface diffusion while the density is gradually decreased as a compensation. On the other hand, with the increased DT, the size and density of Au NPs decrease due to the evaporation of Au at relatively high annealing temperature at 950 °C.

  14. Annealing of ion irradiated high TC Josephson junctions studied by numerical simulations

    International Nuclear Information System (INIS)

    Sirena, M.; Matzen, S.; Bergeal, N.; Lesueur, J.; Faini, G.; Bernard, R.; Briatico, J.; Crete, D. G.

    2009-01-01

    Recently, annealing of ion irradiated high T c Josephson iunctions (JJs) has been studied experimentally in the perspective of improving their reproducibility. Here we present numerical simulations based on random walk and Monte Carlo calculations of the evolution of JJ characteristics such as the transition temperature T c ' and its spread ΔT c ' , and compare them with experimental results on junctions irradiated with 100 and 150 keV oxygen ions, and annealed at low temperatures (below 80 deg. C). We have successfully used a vacancy-interstitial annihilation mechanism to describe the evolution of the T c ' and the homogeneity of a JJ array, analyzing the evolution of the defects density mean value and its distribution width. The annealing first increases the spread in T c ' for short annealing times due to the stochastic nature of the process, but then tends to reduce it for longer times, which is interesting for technological applications

  15. Evolution of the radiation-induced defect structure in 316 type stainless steel after post-irradiation annealing

    Energy Technology Data Exchange (ETDEWEB)

    Van Renterghem, W., E-mail: wvrenter@sckcen.be; Konstantinović, M.J., E-mail: mkonstan@sckcen.be; Vankeerberghen, M., E-mail: mvankeer@sckcen.be

    2014-09-15

    Highlights: • TEM study of irradiated CW316 steel after post-irradiation annealing. • Frank loops were removed after annealing at 550 °C, by unfaulting and growing. • The cavity density decreases after annealing at 550 °C, but not completely removed. • Frank loop and cavity removal is controlled by the annealing temperature. • The dissolution of γ' precipitates is controlled by the iron diffusion length. - Abstract: The thermal stability of Frank loops, black dots, cavities and γ′ precipitates in an irradiated 316 stainless steel was studied by transmission electron microscopy. The samples were retrieved from a thimble tube irradiated at around 320 °C up to 80 dpa in a commercial nuclear power reactor, and thermally annealed, varying both annealing temperature and time. With increasing annealing temperature the density of all defects gradually decreased, resulting in the complete removal of Frank loops at 550 °C. In contrast to other defects, the density of the γ′ precipitates sharply decreased with increasing annealing time, which indicates that the dissolution of the γ′ precipitates is governed by the iron diffusion length.

  16. CdCl{sub 2} activation treatment: A comprehensive study by monitoring the annealing temperature

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Bing Lei; Rimmaudo, Ivan; Salavei, Andrei [LAPS-Laboratory for Applied Physics, Department of Computer Science, University of Verona, Ca' Vignal 1, Strada Le Grazie 15, 37134 Verona (Italy); Piccinelli, Fabio [Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona (Italy); Di Mare, Simone [LAPS-Laboratory for Applied Physics, Department of Computer Science, University of Verona, Ca' Vignal 1, Strada Le Grazie 15, 37134 Verona (Italy); Menossi, Daniele; Bosio, Alessio; Romeo, Nicola [Physics and Earth Science Department, University of Parma, V.le G.P. Usberti 7A, 43124 (Italy); Romeo, Alessandro, E-mail: alessandro.romeo@univr.it [LAPS-Laboratory for Applied Physics, Department of Computer Science, University of Verona, Ca' Vignal 1, Strada Le Grazie 15, 37134 Verona (Italy)

    2015-05-01

    CdTe thin film solar cells have demonstrated high scalability, high efficiency and low cost fabrication process. One of the key factors for the achievements of this technology is the transformation of the absorber layer by an activation treatment where chlorine reacts with CdTe in a controlled atmosphere or in air, improving the electrical properties of the absorber and enhancing the intermixing of the CdS/CdTe layers. With this work we study the activation process by analyzing the CdCl{sub 2} treatment made by wet deposition with different annealing temperatures from 310 °C up to 410 °C in air keeping the same CdCl{sub 2} concentration in methanol solution. In this way the whole dynamic of the chemical reaction from the minimum activation energy is analyzed. Activated CdTe layers have been analyzed by means of X-ray diffraction and atomic force microscopy. Finished devices with efficiencies from 8% for the low temperature annealing up to more than 14% for the high temperature ones have been thoroughly analyzed by current-voltage, capacitance-voltage and drive-level capacitance profiling techniques. The best performance has been achieved with an annealing temperature of 395 °C. - Highlights: • CdCl{sub 2} treatment with 6 different annealing temperatures has been studied. • The amount and the nature of defects change drastically with temperature. • Jsc is proportional to annealing temperature and to grain size. • Efficiency increases with annealing temperature until a threshold is reached.

  17. Reaction kinetics of dolomite rim growth

    Science.gov (United States)

    Helpa, V.; Rybacki, E.; Abart, R.; Morales, L. F. G.; Rhede, D.; Jeřábek, P.; Dresen, G.

    2014-04-01

    Reaction rims of dolomite (CaMg[CO3]2) were produced by solid-state reactions at the contacts of oriented calcite (CaCO3) and magnesite (MgCO3) single crystals at 400 MPa pressure, 750-850 °C temperature, and 3-146 h annealing time to determine the reaction kinetics. The dolomite reaction rims show two different microstructural domains. Elongated palisades of dolomite grew perpendicular into the MgCO3 interface with length ranging from about 6 to 41 µm. At the same time, a 5-71 µm wide rim of equiaxed granular dolomite grew at the contact with CaCO3. Platinum markers showed that the original interface is located at the boundary between the granular and palisade-forming dolomite. In addition to dolomite, a 12-80 µm thick magnesio-calcite layer formed between the dolomite reaction rims and the calcite single crystals. All reaction products show at least an axiotactic crystallographic relationship with respect to calcite reactant, while full topotaxy to calcite prevails within the granular dolomite and magnesio-calcite. Dolomite grains frequently exhibit growth twins characterized by a rotation of 180° around one of the equivalent axis. From mass balance considerations, it is inferred that the reaction rim of dolomite grew by counter diffusion of MgO and CaO. Assuming an Arrhenius-type temperature dependence, activation energies for diffusion of CaO and MgO are E a (CaO) = 192 ± 54 kJ/mol and E a (MgO) = 198 ± 44 kJ/mol, respectively.

  18. Effect of thermal annealing on the microstructures and photocatalytic performance of silver orthophosphate: The synergistic mechanism of Ag vacancies and metallic Ag

    International Nuclear Information System (INIS)

    Yan, Tingjiang; Guan, Wenfei; Xiao, Ying; Tian, Jun; Qiao, Zheng; Zhai, Huishan; Li, Wenjuan; You, Jinmao

    2017-01-01

    Highlights: • Ag_3PO_4 was initially prepared via ion-exchange reaction and then annealed in air. • Thermal annealing also resulted in the formation of metallic Ag and Ag vacancies. • The annealed samples exhibited superior activity to the pristine sample. • Both Ag vacancies and metallic Ag contributed to the high activity. - Abstract: In this work, a simple thermal annealing route has been developed to improve the photocatalytic performance of silver orthophosphate (Ag_3PO_4) photocatalyst toward organic pollutants degradation under visible light irradiation. The experimental results indicated that thermal treatment of Ag_3PO_4 led to an obvious lattice shift towards right and significantly narrowed band gap energies due to the formation of Ag vacancies and metallic Ag during Ag_3PO_4 decomposition. These structural variations notably affected the photocatalytic performance of Ag_3PO_4 photocatalysts. The activity of the annealed samples was found to be significantly enhanced toward the degradation of MO dye. The highest activity was observed over the sample annealed at 400 °C, which exceeded that of pristine Ag_3PO_4 by a factor of about 21 times. By means of photoluminescence spectroscopy and photoelectrochemical measurements, we propose that the enormous enhancement in activity was mainly attributed to the efficient separation of photogenerated electrons and holes driven by the synergistic effect of Ag vacancies and metallic Ag. The strong interaction between annealed particles also inhibited the dissolution of Ag"+ from Ag_3PO_4 into aqueous solution, contributing to an improved photocatalytic stability. The strategy presented here provides an ideal platform for the design of other highly efficient and stable Ag-based photocatalysts for broad applications in the field of photocatalysis.

  19. WO{sub 3} nanorods prepared by low-temperature seeded growth hydrothermal reaction

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Chai Yan [School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Abdul Razak, Khairunisak, E-mail: khairunisak@eng.usm.my [School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); NanoBiotechnology Research and Innovation (NanoBRI), Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Lockman, Zainovia, E-mail: zainovia@eng.usm.my [School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)

    2014-03-05

    Highlights: • WO{sub 3} nanorods with 5–10 nm diameter were grown directly on seeded tungsten foil. • WO{sub 3} nanorods were successfully grown at low temperature of 80 °C. • WO{sub 3} nanorods were grown on the entire surface of the seed layer after 24 h. • Annealed nanorods showed better electrochromic properties than as-made nanorods. -- Abstract: This work describes the first tungsten oxide (WO{sub 3}) nanorods hydrothermally grown on W foil. WO{sub 3} nanorods were successfully grown at low hydrothermal temperature of 80 °C by seeded growth hydrothermal reaction. The seed layer was prepared by thermally oxidized the W foil at 400 °C for 0.5 h. This work discusses the effect of hydrothermal reaction and annealing period on the morphological, structural, and electrochromic properties of WO{sub 3} nanorods. Various hydrothermal reaction periods (8–24 h) were studied. Monoclinic WO{sub 3} nanorods with 5–10 nm diameter were obtained after hydrothermal reaction for 24 h. These 24 h WO{sub 3} nanorods were also annealed at 400 °C with varying dwelling periods (0.5–4 h). Electrochromic properties of WO{sub 3} nanorods in an acidic electrolyte were analyzed using cyclic voltammetry and UV–vis spectrophotometry. WO{sub 3} nanorods annealed at 400 °C for 1 h showed the highest charge capacity and the largest optical contrast among the 24 h WO{sub 3} films. The sample also showed good cycling stability without significant degradation. Based on the results, the reaction mechanism of WO{sub 3} nanorod formation on W foil was proposed.

  20. Reaction time in relation to duration of heroin abuse

    Directory of Open Access Journals (Sweden)

    Martinović-Mitrović Slađana

    2011-01-01

    Full Text Available Introduction. Consequences of heroin abuse include organic damage of cerebral structures. The level of impairments is in a direct and positive relation with the length of heroin abuse. Objective. The aim of this research was the evaluation of the reaction time with heroin addicts with different length of substance abuse. Methods. Research method: 90 examinees were divided into three groups with relation to the length of heroin abuse. Data collection included a questionnaire referring to socio-demographic and addictive characteristics. A specially designed programme was used for the evaluation of reaction time to audio/ visual signal. Results. In relation to the reaction time as overall model, the difference between examinees with different length of heroin abuse can be found on the marginal level of significance (F=1.69; df=12; p=0.07. In visual modality, with the increase of length of heroin abuse leads to a significant prolongation of simple (the first visual sign: F=3.29; df=2; p=0.04 and choice reaction time (the second visual sign: F=4.97; df=2; p=0.00; the third visual sign: F=3.08; df=2; p=0.05. Longer heroin consumption also leads to the prolongation of the simple (the first auditory task: F=3.41; df=2; p=0.04 and the complex auditory reaction time (the second auditory task: F=5.67; df=2; p=0.01; the third auditory task: F=6.42; df=2; p=0.00. Conclusion. Heroin abuse leads to the prolongation of both simple and choice reaction time in visual as well as auditory modality. The average daily dose of opiates was the most important predictor of the abovementioned cognitive dysfunction.

  1. Effects of recrystallization annealing on mechanical properties of cold-rolled PdNi5 wires

    Directory of Open Access Journals (Sweden)

    Aleksandra Ivanović

    2016-03-01

    Full Text Available The aim of this investigation was to determine the influence of the recrystallization temperature and recrystallization time on the microstructure and mechanical properties of the PdNi5 alloy subjected to cold deformation in the process of rolling at a constant deformation degree. The samples of PdNi5 alloy were recrystallization annealed within the temperature range of 200-1000ºC and annealing time range of 20-45 min after cold rolling with deformation degree of 97%. The tensile test was carried out using universal material testing machine. The hardness was also measured on the combined device for measuring Vickers and Brinell hardness. Metallographic observations were performed on an optical microscope. The analysis of the results of investigations regarding the microstructural changes and corresponding mechanical properties of cold-rolled PdNi5 strips shows that annealing temperature of 500ºC was sufficient to activate the energy for various recrystallization processes causing a change in the mechanical properties of cold-rolled PdNi5 strips. The annealing time, at constant annealing temperature, almost did not affect a recrystallization temperature and the mechanical properties of the cold-rolled PdNi5 strips.

  2. Force, reaction time, and precision of Kung Fu strikes.

    Science.gov (United States)

    Neto, Osmar Pinto; Bolander, Richard; Pacheco, Marcos Tadeu Tavares; Bir, Cynthia

    2009-08-01

    The goal was to compare values of force, precision, and reaction time of several martial arts punches and palm strikes performed by advanced and intermediate Kung Fu practitioners, both men and women. 13 Kung Fu practitioners, 10 men and three women, participated. Only the men, three advanced and seven intermediate, were considered for comparisons between levels. Reaction time values were obtained using two high speed cameras that recorded each strike at 2500 Hz. Force of impact was measured by a load cell. For comparisons of groups, force data were normalized by participant's body mass and height. Precision of the strikes was determined by a high speed pressure sensor. The results show that palm strikes were stronger than punches. Women in the study presented, on average, lower values of reaction time and force but higher values of precision than men. Advanced participants presented higher forces than intermediate participants. Significant negative correlations between the values of force and precision and the values of force and reaction time were also found.

  3. Understanding the microwave annealing of silicon

    Directory of Open Access Journals (Sweden)

    Chaochao Fu

    2017-03-01

    Full Text Available Though microwave annealing appears to be very appealing due to its unique features, lacking an in-depth understanding and accurate model hinder its application in semiconductor processing. In this paper, the physics-based model and accurate calculation for the microwave annealing of silicon are presented. Both thermal effects, including ohmic conduction loss and dielectric polarization loss, and non-thermal effects are thoroughly analyzed. We designed unique experiments to verify the mechanism and extract relevant parameters. We also explicitly illustrate the dynamic interaction processes of the microwave annealing of silicon. This work provides an in-depth understanding that can expedite the application of microwave annealing in semiconductor processing and open the door to implementing microwave annealing for future research and applications.

  4. Verbal Processing Reaction Times in "Normal" and "Poor" Readers.

    Science.gov (United States)

    Culbertson, Jack; And Others

    After it had been determined that reaction time (RT) was a sensitive measure of hemispheric dominance in a verbal task performed by normal adult readers, the reaction times of three groups of subjects (20 normal reading college students, 12 normal reading third graders and 11 poor reading grade school students) were compared. Ss were exposed to…

  5. Rapid Thermal annealing of silicon layers amorphized by ion implantation

    International Nuclear Information System (INIS)

    Hasenack, C.M.

    1986-01-01

    The recrystallization behavior and the supression mechanisms of the residual defects of silicon layers amorphized by ion implantation, were investigated. The samples were annealed with the aid of a rapid thermal annealing (RTA) system at temperature range from 850 to 1200 0 C, and annealing time up to 120 s. Random and aligned Rutherford backscattering spectroscopy were used to analyse the samples. Similarities in the recrystallization behavior for layers implanted with ions of the same chemical groups such as As or Sb; Ge, Sn or Pb, In or Ga, are observed. The results show that the effective supression of resisual defects of the recrystallired layers is vinculated to the redistribution of impurities via thermal diffusion. (author) [pt

  6. Effect of annealing time on optical and electrical properties of CdS thin films

    Science.gov (United States)

    Soliya, Vanshika; Tandel, Digisha; Patel, Chandani; Patel, Kinjal

    2018-05-01

    Cadmium sulphide (CdS) is semiconductor compound of II-VI group. Thin film of CdS widely used in the applications such as, a buffer layer in copper indium diselenide (CIS) hetrojunction based solar cells, transistors, photo detectors and light emitting diodes. Because of the ease of making like chemical bath deposition (CBD), screen printing and thermal evaporation. It is extensively used in the CIS based solar cells as a buffer layers. The buffer layers usually used for reducing the interface recombination of the photo generated carriers by means of improving the lattice mismatch between the layers. The optimum thickness and the optoelectronics properties of CdS thin films like, optical band gap, electrical resistivity, structure, and composition etc., are to be considering for its use as a buffer layer. In the present study the CdS thin film were grown by simple dip coating method. In this method we had prepared 0.1M Cadmium-thiourea precursor solution. Before the deposition process of CdS, glass substrate has been cleaned using Methanol, Acetone, Trichloroethylene and De-ionized (DI) water. After coating of precursor layer, it was heated at 200 °C for themolysis. Then after CdS films were annealed at 200 °C for different time and studied its influence on the optical transmission, band gap, XRD, raman and the electrical resistivity. As increasing the annealing time we had observed the average transmission of the films was reduce after the absorption edge. In addition to the blue shift of absorption edge was observed. The observed optimum band gap was around 2.50 eV. XRD and raman analysis confirms the cubuc phase of CdS. Hot probe method confirms the n-type conductivity of the CdS film. Hall probe data shows the resistivity of the films was in the order of 103 Ωcm. Observed data signifies its future use in the many optoelectronics devices.

  7. Post deposition annealing effect on the properties of Al2O3/InP interface

    Science.gov (United States)

    Kim, Hogyoung; Kim, Dong Ha; Choi, Byung Joon

    2018-02-01

    Post deposition in-situ annealing effect on the interfacial and electrical properties of Au/Al2O3/n-InP junctions were investigated. With increasing the annealing time, both the barrier height and ideality factor changed slightly but the series resistance decreased significantly. Photoluminescence (PL) measurements showed that the intensities of both the near band edge (NBE) emission from InP and defect-related bands (DBs) from Al2O3 decreased with 30 min annealing. With increasing the annealing time, the diffusion of oxygen (indium) atoms into Al2O3/InP interface (into Al2O3 layer) occurred more significantly, giving rise to the increase of the interface state density. Therefore, the out-diffusion of oxygen atoms from Al2O3 during the annealing process should be controlled carefully to optimize the Al2O3/InP based devices.

  8. Models for embrittlement recovery due to annealing of reactor pressure vessel steels

    International Nuclear Information System (INIS)

    Eason, E.D.; Wright, J.E.; Nelson, E.E.; Odette, G.R.; Mader, E.V.

    1995-05-01

    The reactor pressure vessel (RPV) surrounding the core of a commercial nuclear power plant is subject to embrittlement due to exposure to high energy neutrons. The effects of irradiation embrittlement can be reduced by thermal annealing at temperatures higher than the normal operating conditions. However, a means of quantitatively assessing the effectiveness of annealing for embrittlement recovery is needed. The objective of this work was to analyze the pertinent data on this issue and develop quantitative models for estimating the recovery in 30 ft-lb (41 J) Charpy transition temperature and Charpy upper shelf energy due to annealing. Data were gathered from the Test Reactor Embrittlement Data Base and from various annealing reports. An analysis data base was developed, reviewed for completeness and accuracy, and documented as part of this work. Independent variables considered in the analysis included material chemistries, annealing time and temperature, irradiation time and temperature, fluence, and flux. To identify important variables and functional forms for predicting embrittlement recovery, advanced statistical techniques, including pattern recognition and transformation analysis, were applied together with current understanding of the mechanisms governing embrittlement and recovery. Models were calibrated using multivariable surface-fitting techniques. Several iterations of model calibration, evaluation with respect to mechanistic and statistical considerations, and comparison with the trends in hardness data produced correlation models for estimating Charpy upper shelf energy and transition temperature after irradiation and annealing. This work provides a clear demonstration that (1) microhardness recovery is generally a very good surrogate for shift recovery, and (2) there is a high level of consistency between the observed annealing trends and fundamental models of embrittlement and recovery processes

  9. Crystallization to polycrystalline silicon thin film and simultaneous inactivation of electrical defects by underwater laser annealing

    Energy Technology Data Exchange (ETDEWEB)

    Machida, Emi [Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192 (Japan); Research Fellowships of the Japan Society for the Promotion of Science, Japan Society for the Promotion of Science, 1-8 Chiyoda, Tokyo 102-8472 (Japan); Horita, Masahiro; Ishikawa, Yasuaki; Uraoka, Yukiharu [Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192 (Japan); Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Honcho, Kawaguchi, Saitama 332-0012 (Japan); Ikenoue, Hiroshi [Graduate School of Information Science and Electrical Engineering, Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395 (Japan)

    2012-12-17

    We propose a low-temperature laser annealing method of a underwater laser annealing (WLA) for polycrystalline silicon (poly-Si) films. We performed crystallization to poly-Si films by laser irradiation in flowing deionized-water where KrF excimer laser was used for annealing. We demonstrated that the maximum value of maximum grain size of WLA samples was 1.5 {mu}m, and that of the average grain size was 2.8 times larger than that of conventional laser annealing in air (LA) samples. Moreover, WLA forms poly-Si films which show lower conductivity and larger carrier life time attributed to fewer electrical defects as compared to LA poly-Si films.

  10. On crystallization of bisphenol-A polycarbonate thin films upon annealing

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chunhong; Li, Qichao; Mao, Wenfeng; Wang, Peng; He, Chunqing, E-mail: hecq@whu.edu.cn

    2015-10-16

    Crystallization of polycarbonate (PC) films as a function of annealing time has been investigated by various methods. A distinct diffraction peak at 17.56°, a sharp decrease of film thickness, an increase of refractive index and branch-type structures on the surface are found merely for the film after crystallization. Interestingly, positron annihilation parameters demonstrate fractional free-volumes in PC films vary significantly not only before crystallization but also at the early stage of annealing, which are not found by other methods. The results show that free-volumes in PC film must be increased remarkably before crystallization, which enables the occurrence of molecule rearrangement. - Highlights: • Fractional free-volume in PC film decreased of early stage of annealing. • Crystallization of PC film on Si substrate occurred after annealed for ∼48 hours. • Fractional free-volume in PC film increased remarkably before crystallization. • Positron diffusion length and S parameter revealed the variation of free volumes.

  11. On crystallization of bisphenol-A polycarbonate thin films upon annealing

    International Nuclear Information System (INIS)

    Yang, Chunhong; Li, Qichao; Mao, Wenfeng; Wang, Peng; He, Chunqing

    2015-01-01

    Crystallization of polycarbonate (PC) films as a function of annealing time has been investigated by various methods. A distinct diffraction peak at 17.56°, a sharp decrease of film thickness, an increase of refractive index and branch-type structures on the surface are found merely for the film after crystallization. Interestingly, positron annihilation parameters demonstrate fractional free-volumes in PC films vary significantly not only before crystallization but also at the early stage of annealing, which are not found by other methods. The results show that free-volumes in PC film must be increased remarkably before crystallization, which enables the occurrence of molecule rearrangement. - Highlights: • Fractional free-volume in PC film decreased of early stage of annealing. • Crystallization of PC film on Si substrate occurred after annealed for ∼48 hours. • Fractional free-volume in PC film increased remarkably before crystallization. • Positron diffusion length and S parameter revealed the variation of free volumes

  12. Influence of oxygen annealing on the dielectric properties of SrBi2(V0.1Nb0.9)2O9 ceramics

    International Nuclear Information System (INIS)

    Wu, Y.; Forbess, M.; Seraji, S.; Limmer, S.; Chou, T.; Cao, G.Z.

    2001-01-01

    The influences of O 2 and N 2 annealing on the dielectric properties of SrBi 2 (V 0.1 Nb 0.9 ) 2 O 9 (SBVN) ferroelectrics were studied. Ceramic samples were prepared by reaction sintering a powder mixture of constituent oxides at 950 deg. C for 2 h in air. Some samples were also subsequently annealed at 800 deg. C for 3 h in O 2 or N 2 . With O 2 annealing, the Curie point of the SBVN ferroelectrics changed from ∼433 to ∼438 deg. C and the peak dielectric constant increased from ∼760 to ∼1010 (at 100 kHz). However, no change in the Curie point was found with N 2 annealing. Furthermore, O 2 annealing was found to reduce significantly both the dielectric constant and loss tangent of the SBVN ferroelectrics at frequencies below 1000 Hz. XRD results revealed a small reduction in the lattice constants with O 2 annealing, but no appreciable change with N 2 annealing. In addition, no detectable change in the microstructure of the SBVN samples was found with annealing. These results imply that some V 4+ ions, which are compensated by the formation of oxygen vacancies, existed in the SBVN ferroelectrics prior to O 2 annealing. V 4+ ions were oxidized to V 5+ with O 2 annealing, which resulted in improved dielectric properties. (author)

  13. Mantra, music and reaction times: a study of its applied aspects

    Directory of Open Access Journals (Sweden)

    Varun Malhotra, Rinku Garg, Usha Dhar, Neera Goel, Yogesh Tripathy, Iram Jaan, Sachit Goyal, Sumit Arora

    2014-11-01

    Full Text Available Aims &Objectives: The mechanism of the effects of music is still under scientific study and needs to be understood in a better way. We designed this study to see how music affects reaction time and concentration. The aim of our study was to study the effect of Gayatri mantra on reaction time. Material and Methods: 30 healthy subjects were selected for the study. Baseline record of Visual online Reaction time test was taken. Online visual reaction time was measured during listening to Gayatri Mantra was taken. Results:The reaction times decreased significantly p<0.001. Conclusion: Listening to music at work area reduces distractions, helps increase concentration and delays fatigue. It can be used to heal tinnitus, as an educational tool to develop children with special needs, Alzheimers disease, to improve motor skills in Parkinsonism and help alleviate pain after surgery.

  14. Remarkable changes in interface O vacancy and metal-oxide bonds in amorphous indium-gallium-zinc-oxide thin-film transistors by long time annealing at 250 °C

    Energy Technology Data Exchange (ETDEWEB)

    Chowdhury, Md Delwar Hossain; Um, Jae Gwang; Jang, Jin, E-mail: jjang@khu.ac.kr [Advanced Display Research Center and Department of Information Display, Kyung Hee University, Seoul 130-701 (Korea, Republic of)

    2014-12-08

    We have studied the effect of long time post-fabrication annealing on negative bias illumination stress (NBIS) of amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film-transistors. Annealing for 100 h at 250 °C increased the field effect mobility from 14.7 cm{sup 2}/V s to 17.9 cm{sup 2}/V s and reduced the NBIS instability remarkably. Using X-ray photoelectron spectroscopy, the oxygen vacancy and OH were found to exist at the interfaces of a-IGZO with top and bottom SiO{sub 2}. Long time annealing helps to decrease the vacancy concentration and increase the metal-oxygen bonds at the interfaces; this leads to increase in the free carrier concentrations in a-IGZO and field-effect mobility. X-ray reflectivity measurement indicated the increment of a-IGZO film density of 5.63 g cm{sup −3} to 5.83 g cm{sup −3} (3.4% increase) by 100 h annealing at 250 °C. The increase in film density reveals the decrease of O vacancy concentration and reduction of weak metal-oxygen bonds in a-IGZO, which substantially helps to improve the NBIS stability.

  15. X-ray studies of interface Fe-oxide in annealed MgO based magnetic tunneling junctions

    Energy Technology Data Exchange (ETDEWEB)

    Telesca, D., E-mail: donaldtelesca@gmail.com [Department of Physics, University of Connecticut, 2152 Hillside Road, Storrs, CT 06269 (United States); Space Vehicles Directorate, Air Force Research Lab (AFRL), Kirtland AFB, NM 87117 (United States); Sinkovic, B. [Space Vehicles Directorate, Air Force Research Lab (AFRL), Kirtland AFB, NM 87117 (United States); Yang, See-Hun; Parkin, S.S.P. [IBM Amaden Research Center, 650 Harry Road, San Jose, CA 95120 (United States)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer This work concludes the presence of oxide in MgO/transition-metal bi-layers. Black-Right-Pointing-Pointer Thermal annealing causes a possible structural transformation of the oxide. Black-Right-Pointing-Pointer This is first evidence for a possible structural change of the oxide. Black-Right-Pointing-Pointer First use of the O K-edge XAS signature of TM oxides to confirm presence of oxide. Black-Right-Pointing-Pointer We see a diffusion of oxygen and a decrease in interface roughness. -- Abstract: X-ray absorption spectroscopy and X-ray scattering have been used to determine the oxidation reactions at the buried MgO/Fe interface as a result of the deposition of MgO. We confirm that Fe-oxide is present at the MgO/Fe and MgO/CoFe interfaces and amounts to less than 1 mL in thickness. The Fe-oxide is a mixture of different iron oxide phases within the ultra-thin layer which can be reduced following annealing. We observe the transformation of the interfacial oxide from a more Fe{sub 2}O{sub 3}-like phase to a more FeO-like phase following annealing, and that this process is most noticeable between the 200 and 350 Degree-Sign C annealing steps. In addition, the formation of a more bulk like MgO electronic structure following annealing was observed.

  16. X-ray Diffraction Investigation of Annealing Behavior of Peened Surface Deformation Layer on Precipitation Hardening Stainless Steel

    Science.gov (United States)

    Huang, Junjie; Wang, Zhou; Gan, Jin; Yang, Ying; Huang, Feng; Wu, Gang; Meng, Qingshuai

    2018-05-01

    In order to investigate the recrystallization behavior of peened surface deformation layer of precipitation hardening stainless steel, a classic x-ray diffraction line profile analysis, Voigt method, was carried out on peened 17-4PH with different isothermal annealing temperatures. The activation energy of domain boundary migration ( Q a) and the activation energy of microstrain relaxation ( Q b) were calculated by regression analysis in different annealing temperature conditions. The results show that the value of Q a decreases with annealing temperature increasing, which is due to the influence of precipitation (ɛ-Cu) size on the movements of grain and subgrain boundaries. The maximum growth rate of ɛ-Cu particles occurs during 400 to 500 °C interval. Compared with growth behavior of domain size, microstrain relaxation behavior is less sensitive to precipitation particle size. The effects of annealing temperature and time on dislocation density are both significant when annealing temperature is lower than 500 °C. However, the effect of annealing temperature on dislocation density becomes insignificant when annealing temperature is higher than 500 °C. 300 °C annealing temperature only leads to the microstrain relaxation but nearly cannot lead to the domain size growth even if prolonging annealing time. Microstructure enhancement effect still exists in plastic deformation layer when 300 °C annealing temperature lasts for 60 min but nearly disappears when 600 °C annealing temperature lasts for 20 min.

  17. X-ray Diffraction Investigation of Annealing Behavior of Peened Surface Deformation Layer on Precipitation Hardening Stainless Steel

    Science.gov (United States)

    Huang, Junjie; Wang, Zhou; Gan, Jin; Yang, Ying; Huang, Feng; Wu, Gang; Meng, Qingshuai

    2018-04-01

    In order to investigate the recrystallization behavior of peened surface deformation layer of precipitation hardening stainless steel, a classic x-ray diffraction line profile analysis, Voigt method, was carried out on peened 17-4PH with different isothermal annealing temperatures. The activation energy of domain boundary migration (Q a) and the activation energy of microstrain relaxation (Q b) were calculated by regression analysis in different annealing temperature conditions. The results show that the value of Q a decreases with annealing temperature increasing, which is due to the influence of precipitation (ɛ-Cu) size on the movements of grain and subgrain boundaries. The maximum growth rate of ɛ-Cu particles occurs during 400 to 500 °C interval. Compared with growth behavior of domain size, microstrain relaxation behavior is less sensitive to precipitation particle size. The effects of annealing temperature and time on dislocation density are both significant when annealing temperature is lower than 500 °C. However, the effect of annealing temperature on dislocation density becomes insignificant when annealing temperature is higher than 500 °C. 300 °C annealing temperature only leads to the microstrain relaxation but nearly cannot lead to the domain size growth even if prolonging annealing time. Microstructure enhancement effect still exists in plastic deformation layer when 300 °C annealing temperature lasts for 60 min but nearly disappears when 600 °C annealing temperature lasts for 20 min.

  18. Radiation annealing mechanisms of low-alloy reactor pressure vessel steels dependent on irradiation temperature and neutron fluence

    International Nuclear Information System (INIS)

    Pachur, D.

    1982-01-01

    Heat treatment after irradiation of reactor pressure vessel steels showed annealing of irradiation embrittlement. Depending on the irradiation temperature, the embrittlement started to anneal at about 220 0 C and was completely annealed at 500 0 C with 4 h of annealing time. The annealing behavior was normally measured in terms of the Vickers hardness increase produced by irradiation relative to the initial hardness as a function of the annealing temperature. Annealing results of other mechanical properties correspond to hardness results. During annealing, various recovery mechanisms occur in different temperature ranges. These are characterized by activation energies from 1.5 to 2.1 eV. The individual mechanisms were determined by the different time dependencies at various temperatures. The relative contributions of the mechanisms showed a neutron fluence dependence, with the lower activation energy mechanisms being predominant at low fluence and vice versa. In the temperature range where partial annealing of a mechanism took place during irradiation, an increase in activation energy was observed. Trend curves for the increase in transition temperature with irradiation, for the relative increase of Vickers hardness and yield strength, and for the relative decrease of Charpy-V upper shelf energy are interpreted by the behavior of different mechanisms

  19. Effect of transient annealing on patterned CoFeB-based magnetic tunnel junctions

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Kuo-Ming; Huang, Chao-Hsien; Lin, Shiao-Chi; Wu, Jong-Ching [Department of Physics and Taiwan SPIN Research Center, National Changhua University of Education, Changhua 50007 (China); Kao, Ming-Jer; Tsai, Ming-Jinn [Industrial Technology Research Institute, Hsinchu 31040 (China); Horng, Lance

    2007-12-15

    In this study, the transient annealing effect on the switching behavior of microstructured Co{sub 60}Fe{sub 20}B{sub 20}-based magnetic tunnel junctions has been studied through magnetoresistance measurements (R-H loop). Elliptical shape of devices with long/short axis of 4/2 micrometers was patterned out of sheet film stack of: Ta(20)/PtMn(15)/CoFeB(3)/Al(0.7)-oxide/CoFeB(2)/Ru(8)/Ta(40) (thickness unit in nanometers) after a conventional long time field cooling annealing. The transient annealing was then executed by sample loading into a furnace with pre-set temperatures ranging from 100 to 400 C for only 5 minutes in the absence of any external magnetic field. The vortex-like reverse of free layer in as-etched MTJ evidently changes to single-domain-like reverser after 200{proportional_to}250 C transient annealing. The magnetoresistance was found to increase with increasing annealing temperatures up to 265 C and then slowly decrease at higher annealing temperatures. The transient thermal annealing creates obvious efforts to repair magnetic properties of MTJ cell befor 265 C annealing and results in less damage at temperature of 350 C and 400 C. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. Effect of transient annealing on patterned CoFeB-based magnetic tunnel junctions

    International Nuclear Information System (INIS)

    Wu, Kuo-Ming; Huang, Chao-Hsien; Lin, Shiao-Chi; Wu, Jong-Ching; Kao, Ming-Jer; Tsai, Ming-Jinn; Horng, Lance

    2007-01-01

    In this study, the transient annealing effect on the switching behavior of microstructured Co 60 Fe 20 B 20 -based magnetic tunnel junctions has been studied through magnetoresistance measurements (R-H loop). Elliptical shape of devices with long/short axis of 4/2 micrometers was patterned out of sheet film stack of: Ta(20)/PtMn(15)/CoFeB(3)/Al(0.7)-oxide/CoFeB(2)/Ru(8)/Ta(40) (thickness unit in nanometers) after a conventional long time field cooling annealing. The transient annealing was then executed by sample loading into a furnace with pre-set temperatures ranging from 100 to 400 C for only 5 minutes in the absence of any external magnetic field. The vortex-like reverse of free layer in as-etched MTJ evidently changes to single-domain-like reverser after 200∝250 C transient annealing. The magnetoresistance was found to increase with increasing annealing temperatures up to 265 C and then slowly decrease at higher annealing temperatures. The transient thermal annealing creates obvious efforts to repair magnetic properties of MTJ cell befor 265 C annealing and results in less damage at temperature of 350 C and 400 C. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. Analysis of the absorption coefficient by annealing in carbon implanted Nd: YVO4

    International Nuclear Information System (INIS)

    Sanchez-Morales, M E; Vazquez, G V; Lifante, G; Cantelar, E; Rickards, J; Trejo-Luna, R

    2011-01-01

    Low loss in optical waveguides is very important in order to achieve high laser efficiency. Waveguide fabrication by ion implantation generates color centers, leading to absorption losses which can be reduced by annealing; however, this process may eliminate the waveguide and hence it is necessary to consider both the optimum annealing time and temperature. This work reports the behavior of the absorption coefficient by successive annealing steps in Nd:YVO 4 implanted with a dose of 5xl0 14 ions/cm 2 .

  2. The influence of annealing atmosphere on the material properties of sol-gel derived SnO2:Sb films before and after annealing

    International Nuclear Information System (INIS)

    Jeng, Jiann-Shing

    2012-01-01

    SnO 2 films with and without Sb doping were prepared by the sol-gel spin-coating method. Material properties of the SnO 2 films with different Sb contents were investigated before and after annealing under O 2 or N 2 . When SnO 2 films are annealed under N 2 or O 2 , the resistivity decreases with increasing annealing temperature, which may be related to the increased crystallinity and reduced film defects. The intensity of SnO 2 peaks for both O 2 - and N 2 -annealed films increases as the annealing temperature increases. Small nodules are revealed on the surface of SnO 2 films after annealing in N 2 or O 2 atmospheres, and some voids are present on the surface of N 2 -annealed SnO 2 films. After doping with Sb, the resistivity of SnO 2 films after annealing in O 2 is greater than that of N 2 -annealed SnO 2 films. The surface morphology of SnO 2 films incorporating different molar ratios of Sb after annealing are similar to that of as-spun SnO 2 films with adding Sb. There were no voids found on the surfaces of N 2 -annealed SnO 2 :Sb films. In addition, the peak intensity of SnO 2 :Sb films after O 2 -annealing is higher than those films after N 2 -annealing. The chemical binding states and Hall mobility of the high-temperature annealed SnO 2 films without and with adding Sb are also related to the annealing atmospheres. This study discusses the connection among the material properties of the SnO 2 films with different Sb contents and how these properties are influenced by the Sb-doping concentration and the annealing atmospheres of SnO 2 films.

  3. Effects of annealing on the recombination dynamics of low-temperature grown ZnO nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Hilker, B.; Bekeny, C.; Voss, T.; Gutowski, J. [IFP, Universitaet Bremen, 28334 Bremen (Germany); Hauschild, R.; Kalt, H. [Universitaet Karlsruhe, 76128 Karlsruhe (Germany); Postels, B.; Bakin, Andrey; Waag, A. [IHT, TU Braunschweig, 38023 Braunschweig (Germany)

    2007-07-01

    We present systematic temperature and excitation density dependent time-resolved photoluminescence (TRPL) measurements of as-grown and annealed ZnO nanorods fabricated by an aqueous chemical growth (ACG) technique at {proportional_to}90 C. The as-grown nanorods show strong nearband-edge and rather weak deep-level emission indicating their already good optical quality. At 4K, we find a broad emission line at 3.36 eV (line width 30 meV) which we attribute to recombination from a donor band formed through the high donor concentration. After annealing in oxygen and nitrogen atmospheres at 600-800 C well-resolved and sharper excitonic transitions are observed. To understand the recombination dynamics in the nanorods we carried out TRPL measurements using a frequency-doubled femtosecond laser and a streak camera. The as-grown sample shows a very fast monoexponential decay time of {proportional_to}10ps independent of temperature and excitation density. In contrast, the annealed samples exhibit a biexponential decay. Each a fast {tau}1 and a slow {tau}2 time constant have been determined for all annealed samples both of them significantly varying depending on the annealing atmosphere and temperature. This will be discussed on the basis of a phenomenological rate-equation model.

  4. The annealing influence onto the electrical and magnetic behavior of magnetoresistive/insulator system

    International Nuclear Information System (INIS)

    Ahmed, A.M.; Mohamed Abd El-Mo'ez A; Mohamed, H.F.; Diab, A.K.; Mohamed Ami M; Mazen, A.E.A.

    2016-01-01

    This investigation is mainly concerned with the effect of annealing temperature (600, 700, 800 and 900 deg C) in air for (La 0. 7Ba 0.3 MnO 3 ) 1-x /(NiO) x with x = 0 and x = 0.10 samples. It was shown that the annealing temperature does not affect the structure and parameters of rhombohedral lattice of the samples. However, it is observed that the annealing treatment has a notable effect on the electrical resistivity and the metal-semiconductor transition temperature Tms. Temperature dependent magnetization measurements showed a decrease in Curie temperature TC with annealing temperature. In the same time, annealing process decreases the magnetoresistance of La 0.7 Ba 0.3 MnO 3 , in contrast to (La 0.7 Ba 0.3 MnO 3 ) 0.9 /(NiO) 0.1 composite.

  5. Effects of thermal annealing on the performance of Al/ZnO nanorods/Pt structure ultraviolet photodetector

    International Nuclear Information System (INIS)

    Zhou Hai; Fang Guojia; Liu Nishuang; Zhao Xingzhong

    2011-01-01

    Highlights: → Schottky barrier ultraviolet photodetectors were obtained by sputtering Pt electrode and evaporating Al electrode on the top of ZnO nanorod arrays with thermal treatment. When annealing temperature was up to 300 deg. C, the performance of the PDs was improved with the great decrease of response and recovery times. → For annealing temperature at 300 deg. C and above, the responsivity decreases with increasing annealing temperature. → The ratio of detectivity (D254* to D546*) was calculated as high as 103 for all PDs annealed at 300 deg. C and above. - Abstract: ZnO nanorod arrays were fabricated on ZnO coated glass substrate by hydrothermal method. Schottky barrier ultraviolet photodetectors (PDs) were obtained by sputtering Pt electrode and evaporating Al electrode on the top of ZnO nanorod arrays with thermal treatment. It is illustrated that Schottky contacts at the electrode/ZnO NRs interface were formed at the annealing temperature of 300 deg. C and above. When annealing temperature was up to 300 o C, the performance of the PDs was improved with the great decrease of response and recovery times. At the forward bias of 2 V, the Schottky contact PDs showed the biggest responsivity and the best detectivity at the annealing temperature of 300 deg. C. For annealing temperature at 300 deg. C and above, the responsivity decreases with increasing annealing temperature and the ratio of detectivity (D 254 * to D 546 *) was calculated as high as 10 3 for all PDs annealed at 300 deg. C and above.

  6. Chemical reactions at CdS heterojunctions with CuInSe{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, Angel; Rockett, Angus [Department of Materials Science and Engineering, University of Illinois, 1304 West Green Street, Urbana, Illinois 61801 (United States)

    2013-03-15

    The stability of the CdS/CuInSe{sub 2} (CIS) heterojunction is critical to understanding the projected lifetime of CIS devices and the effect of processing conditions on the nanoscale chemistry of the heterojunction. This article reports the results of annealing heterojunctions between CdS deposited by chemical bath deposition and single crystal and polycrystalline CIS films between 200 and 500 Degree-Sign C for 10 to 150 min. No atomic movement was observed by secondary ion mass spectrometry at temperatures of 300 Degree-Sign C and below. At 400 Degree-Sign C even for the shortest time studied, Cu and In were found throughout the region initially consisting of CdS only and Cd was found to have moved into the CIS. In the polycrystal, annealing at 500 Degree-Sign C resulted in movement of Cd throughout the CIS layer. No time dependence was observed in the 400 and 500 Degree-Sign C anneals indicating that a reaction had occurred forming a compound that was in thermodynamic equilibrium with the remaining CIS. Diffusion turns on rapidly between 300 and 400 Degree-Sign C, indicating a high activation energy for atomic movement ({approx}2.4 eV). The onset of diffusion is consistent with the onset of Cu diffusion in CIS.

  7. Substrate-Coated Illumination Droplet Spray Ionization: Real-Time Monitoring of Photocatalytic Reactions

    Science.gov (United States)

    Zhang, Hong; Li, Na; Zhao, Dandan; Jiang, Jie; You, Hong

    2017-09-01

    Real-time monitoring of photocatalytic reactions facilitates the elucidation of the mechanisms of the reactions. However, suitable tools for real-time monitoring are lacking. Herein, a novel method based on droplet spray ionization named substrate-coated illumination droplet spray ionization (SCI-DSI) for direct analysis of photocatalytic reaction solution is reported. SCI-DSI addresses many of the analytical limitations of electrospray ionization (ESI) for analysis of photocatalytic-reaction intermediates, and has potential for both in situ analysis and real-time monitoring of photocatalytic reactions. In SCI-DSI-mass spectrometry (MS), a photocatalytic reaction occurs by loading sample solutions onto the substrate-coated cover slip and by applying UV light above the modified slip; one corner of this slip adjacent to the inlet of a mass spectrometer is the high-electric-field location for launching a charged-droplet spray. After both testing and optimizing the performance of SCI-DSI, the value of this method for in situ analysis and real-time monitoring of photocatalytic reactions was demonstrated by the removal of cyclophosphamide (CP) in TiO2/UV. Reaction times ranged from seconds to minutes, and the proposed reaction intermediates were captured and identified by tandem mass spectrometry. Moreover, the free hydroxyl radical (·OH) was identified as the main radicals for CP removal. These results show that SCI-DSI is suitable for in situ analysis and real-time monitoring of CP removal under TiO2-based photocatalytic reactions. SCI-DSI is also a potential tool for in situ analysis and real-time assessment of the roles of radicals during CP removal under TiO2-based photocatalytic reactions. Graphical Abstract[Figure not available: see fulltext.

  8. Temperature behavior and annealing of insulated gate transistors subjected to localized lifetime control by proton implantation

    International Nuclear Information System (INIS)

    Mogro-Campero, A.; Love, R.P.; Chang, M.F.; Dyer, R.F.

    1987-01-01

    Localized lifetime control by proton implantation can result in a considerable improvement (as much as an order of magnitude or more) in the trade-off between device turn-off time and forward voltage when compared with the unlocalized method of electron irradiation. The physical mechanisms responsible for the qualitative temperature dependences are identified: MOS channel resistance for forward voltage, carrier capture cross-section for turn-off time, and generation and diffusion components of leakage current. Since no catastrophic or unrecoverable behavior is observed, normal device operation within the tested temperature range is possible. Isothermal annealing curves of turn-off time measured after annealing, and corresponding to a few hours annealing time, reveal that a constant turn-off time is reached after about an hour. The constant value increases with temperature, but is still below the unimplanted value after 4 h at 525 0 C. The turn-off time was verified to be constant even after 24 h of annealing at 200 0 C. Lifetime control by proton implantation seems to be more thermally stable than that caused by electron irradiation. (author)

  9. Defect annealing and thermal desorption of deuterium in low dose HFIR neutron-irradiated tungsten

    International Nuclear Information System (INIS)

    Shimada, Masashi; Hara, Masanori; Otsuka, Teppei; Oya, Yasuhisa; Hatano, Yuji

    2015-01-01

    Three tungsten samples irradiated at High Flux Isotope Reactor at Oak Ridge National Laboratory were exposed to deuterium plasma (ion fluence of 1 × 10 26 m −2 ) at three different temperatures (100, 200, and 500 °C) in Tritium Plasma Experiment at Idaho National Laboratory. Subsequently, thermal desorption spectroscopy was performed with a ramp rate of 10 °C min −1 up to 900 °C, and the samples were annealed at 900 °C for 0.5 h. These procedures were repeated three times to uncover defect-annealing effects on deuterium retention. The results show that deuterium retention decreases approximately 70% for at 500 °C after each annealing, and radiation damages were not annealed out completely even after the 3rd annealing. TMAP modeling revealed the trap concentration decreases approximately 80% after each annealing at 900 °C for 0.5 h

  10. Defect annealing and thermal desorption of deuterium in low dose HFIR neutron-irradiated tungsten

    Science.gov (United States)

    Shimada, Masashi; Hara, Masanori; Otsuka, Teppei; Oya, Yasuhisa; Hatano, Yuji

    2015-08-01

    Three tungsten samples irradiated at High Flux Isotope Reactor at Oak Ridge National Laboratory were exposed to deuterium plasma (ion fluence of 1 × 1026 m-2) at three different temperatures (100, 200, and 500 °C) in Tritium Plasma Experiment at Idaho National Laboratory. Subsequently, thermal desorption spectroscopy was performed with a ramp rate of 10 °C min-1 up to 900 °C, and the samples were annealed at 900 °C for 0.5 h. These procedures were repeated three times to uncover defect-annealing effects on deuterium retention. The results show that deuterium retention decreases approximately 70% for at 500 °C after each annealing, and radiation damages were not annealed out completely even after the 3rd annealing. TMAP modeling revealed the trap concentration decreases approximately 80% after each annealing at 900 °C for 0.5 h.

  11. Defect annealing and thermal desorption of deuterium in low dose HFIR neutron-irradiated tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Shimada, Masashi, E-mail: Masashi.Shimada@inl.gov [Fusion Safety Program, Idaho National Laboratory, Idaho Falls, ID (United States); Hara, Masanori [Hydrogen Isotope Research Center, University of Toyama, Toyama (Japan); Otsuka, Teppei [Kyushu University, Interdisciplinary Graduate School of Engineering Science, Higashi-ku, Fukuoka (Japan); Oya, Yasuhisa [Radioscience Research Laboratory, Faculty of Science, Shizuoka University, Shizuoka (Japan); Hatano, Yuji [Hydrogen Isotope Research Center, University of Toyama, Toyama (Japan)

    2015-08-15

    Three tungsten samples irradiated at High Flux Isotope Reactor at Oak Ridge National Laboratory were exposed to deuterium plasma (ion fluence of 1 × 10{sup 26} m{sup −2}) at three different temperatures (100, 200, and 500 °C) in Tritium Plasma Experiment at Idaho National Laboratory. Subsequently, thermal desorption spectroscopy was performed with a ramp rate of 10 °C min{sup −1} up to 900 °C, and the samples were annealed at 900 °C for 0.5 h. These procedures were repeated three times to uncover defect-annealing effects on deuterium retention. The results show that deuterium retention decreases approximately 70% for at 500 °C after each annealing, and radiation damages were not annealed out completely even after the 3rd annealing. TMAP modeling revealed the trap concentration decreases approximately 80% after each annealing at 900 °C for 0.5 h.

  12. Study of the optical properties and the carbonaceous clusters in thermally-annealed CR-39 and Makrofol-E polymer-based solid-state nuclear track detectors

    International Nuclear Information System (INIS)

    El Ghazaly, M.

    2012-01-01

    The induced modifications in the optical properties of CR-39 and Makrofol-E polymer-based solid state nuclear track detectors were investigated after thermal annealing at a temperature of 200 .deg. C for different durations. The optical properties were studied using an UV-visible spectrophotometer. From the UV-visible spectra, the direct and the indirect optical band gaps, Urbach's energies, and the number of carbon atoms in a cluster were determined. The absorbance of CR-39 plastic detector was found to decrease with increasing annealing time while the absorbance of Makrofol-E decreased with increasing annealing time. The width of the tail of localized states in the band gap ΔE was evaluated with the Urbach method. The optical energy band gaps were obtained from the direct and the indirect allowed transitions in K-space. Both of the direct and the indirect band gaps of the annealed CR-39 detector decrease with increasing annealing time while in Makrofol-E, they decreased after an annealing time of 15 minute and then showed no remarkable changes for a prolonged annealing times. Urbach's energy decreased significantly for both CR-39 and Makrofol-E with increasing annealing time. The number of carbon atoms in a cluster increased in the CR-39 detector with increasing annealing time while it decreased with increasing annealing time for Makrofol-E. We may conclude that the CR-39 detector undergoes greater modifications than the Makrofol-E detector upon thermal annealing at 200 .deg. C. In conclusion, the induced modifications in the optical properties of CR-39 and Makrofol-E are correlated with the temperature and the duration of annealing.

  13. Reaction time for processing visual stimulus in a computer-assisted rehabilitation environment.

    Science.gov (United States)

    Sanchez, Yerly; Pinzon, David; Zheng, Bin

    2017-10-01

    To examine the reaction time when human subjects process information presented in the visual channel under both a direct vision and a virtual rehabilitation environment when walking was performed. Visual stimulus included eight math problems displayed on the peripheral vision to seven healthy human subjects in a virtual rehabilitation training (computer-assisted rehabilitation environment (CAREN)) and a direct vision environment. Subjects were required to verbally report the results of these math calculations in a short period of time. Reaction time measured by Tobii Eye tracker and calculation accuracy were recorded and compared between the direct vision and virtual rehabilitation environment. Performance outcomes measured for both groups included reaction time, reading time, answering time and the verbal answer score. A significant difference between the groups was only found for the reaction time (p = .004). Participants had more difficulty recognizing the first equation of the virtual environment. Participants reaction time was faster in the direct vision environment. This reaction time delay should be kept in mind when designing skill training scenarios in virtual environments. This was a pilot project to a series of studies assessing cognition ability of stroke patients who are undertaking a rehabilitation program with a virtual training environment. Implications for rehabilitation Eye tracking is a reliable tool that can be employed in rehabilitation virtual environments. Reaction time changes between direct vision and virtual environment.

  14. Characteristics of OMVPE grown GaAsBi QW lasers and impact of post-growth thermal annealing

    Science.gov (United States)

    Kim, Honghyuk; Guan, Yingxin; Babcock, Susan E.; Kuech, Thomas F.; Mawst, Luke J.

    2018-03-01

    Laser diodes employing a strain-compensated GaAs1-xBix/GaAs1-yPy single quantum well (SQW) active region were grown by organometallic vapor phase epitaxy (OMVPE). High resolution x-ray diffraction, room temperature photoluminescence, and real-time optical reflectance measurements during the OMVPE growth were used to find the optimum process window for the growth of the active region material. Systematic post-growth in situ thermal anneals of various lengths were carried out in order to investigate the impacts of thermal annealing on the laser device performance characteristics. While the lowest threshold current density was achieved after the thermal annealing for 30 min at 630 °C, a gradual decrease in the external differential quantum efficiency was observed as the annealing time increases. It was observed that the temperature sensitivities of the threshold current density increase while those of lasing wavelength and slope efficiency remain nearly constant with increasing annealing time. Z-contrast scanning transmission electron microscopic) analysis revealed inhomogeneous Bi distribution within the QW active region.

  15. Acute physical exercise under hypoxia improves sleep, mood and reaction time.

    Science.gov (United States)

    de Aquino-Lemos, Valdir; Santos, Ronaldo Vagner T; Antunes, Hanna Karen Moreira; Lira, Fabio S; Luz Bittar, Irene G; Caris, Aline V; Tufik, Sergio; de Mello, Marco Tulio

    2016-02-01

    This study aimed to assess the effect of two sessions of acute physical exercise at 50% VO2peak performed under hypoxia (equivalent to an altitude of 4500 m for 28 h) on sleep, mood and reaction time. Forty healthy men were randomized into 4 groups: Normoxia (NG) (n = 10); Hypoxia (HG) (n = 10); Exercise under Normoxia (ENG) (n = 10); and Exercise under Hypoxia (EHG) (n = 10). All mood and reaction time assessments were performed 40 min after awakening. Sleep was reassessed on the first day at 14 h after the initiation of hypoxia; mood and reaction time were measured 28 h later. Two sessions of acute physical exercise at 50% VO2peak were performed for 60 min on the first and second days after 3 and 27 h, respectively, after starting to hypoxia. Improved sleep efficiency, stage N3 and REM sleep and reduced wake after sleep onset were observed under hypoxia after acute physical exercise. Tension, anger, depressed mood, vigor and reaction time scores improved after exercise under hypoxia. We conclude that hypoxia impairs sleep, reaction time and mood. Acute physical exercise at 50% VO2peak under hypoxia improves sleep efficiency, reversing the aspects that had been adversely affected under hypoxia, possibly contributing to improved mood and reaction time.

  16. Influence of initial annealing on structure evolution and magnetic properties of 3.4% Si non-oriented steel during final annealing

    Energy Technology Data Exchange (ETDEWEB)

    Simões Mendanha Pedrosa, Josiane [Department of Physics, Federal University of Ouro Preto, Ouro Preto MG-3540000 (Brazil); Costa Paolinelli, Sebastião da [Research Department Aperam South America, Praça Primeiro de Maio, 9, Timóteo MG-35180018 (Brazil); Barros Cota, André, E-mail: abcota@ufop.br [Department of Physics, Federal University of Ouro Preto, Ouro Preto MG-3540000 (Brazil)

    2015-11-01

    The effect of the initial annealing on structure evolution and magnetic properties during the final annealing of a 3.4% Si non-oriented grain steel was evaluated. Half of the samples were submitted to initial annealing at 1030 °C before cold rolling and all samples were subjected to final annealing process at temperatures from 540 °C to 1100 °C. The magnetic induction and core loss in the final samples, the microstructure by optical microscopy and the crystallographic texture by X-ray diffraction and EBSD were evaluated. The results show that the samples without initial annealing presented better magnetic properties than the samples with initial annealing, due to the higher ratio between Eta fiber and Gamma fiber volume fractions (Eta/Gamma ratio) in their structure after final annealing. - Highlights: • Texture and magnetic properties of 3.4% Si non-oriented electrical steel were measured. • Without initial annealing, better texture and magnetic properties were obtained. • Good texture and magnetic properties are obtained with Steckel hot band structure.

  17. PERBANDINGAN KINERJA ALGORITMA GENETIKA DAN SIMULATED ANNEALING UNTUK MASALAH MULTIPLE OBJECTIVE PADA PENJADWALAN FLOWSHOP

    Directory of Open Access Journals (Sweden)

    I Gede Agus Widyadana

    2002-01-01

    Full Text Available The research is focused on comparing Genetics algorithm and Simulated Annealing in the term of performa and processing time. The main purpose is to find out performance both of the algorithm to solve minimizing makespan and total flowtime in a particular flowshop system. Performances of the algorithms are found by simulating problems with variation of jobs and machines combination. The result show the Simulated Annealing is much better than the Genetics up to 90%. The Genetics, however, only had score in processing time, but the trend that plotted suggest that in problems with lots of jobs and lots of machines, the Simulated Annealing will run much faster than the Genetics. Abstract in Bahasa Indonesia : Penelitian ini difokuskan pada pembandingan algoritma Genetika dan Simulated Annealing ditinjau dari aspek performa dan waktu proses. Tujuannya adalah untuk melihat kemampuan dua algoritma tersebut untuk menyelesaikan problem-problem penjadwalan flow shop dengan kriteria minimasi makespan dan total flowtime. Kemampuan kedua algoritma tersebut dilihat dengan melakukan simulasi yang dilakukan pada kombinasi-kombinasi job dan mesin yang berbeda-beda. Hasil simulasi menunjukan algoritma Simulated Annealing lebih unggul dari algoritma Genetika hingga 90%, algoritma Genetika hanya unggul pada waktu proses saja, namun dengan tren waktu proses yang terbentuk, diyakini pada problem dengan kombinasi job dan mesin yang banyak, algoritma Simulated Annealing dapat lebih cepat daripada algoritma Genetika. Kata kunci: Algoritma Genetika, Simulated Annealing, flow shop, makespan, total flowtime.

  18. Effect of Annealing Time for Quenching CuAl7Fe5Ni5W2Si2 Bronze on the Microstructure and Mechanical Properties

    Directory of Open Access Journals (Sweden)

    B. P. Pisarek

    2012-04-01

    Full Text Available This paper presents the influence of annealing time 30, 60 and 120 min at 1000°C for quenching CuAl7Fe5Ni5W2Si2 bronze in 10% water solution of NaCl, on the microstructure and mechanical properties. The presented results concern the species newly developed aluminum-iron-nickel bronze, with additions W and Si.In order to determine changes in the microstructure of the hardened bronze metallographic studies were performed on cylindrical samples of diameter 10 mm, on the metallographic microscope with digital image analysis, X-ray phase analysis, EDX point with the digital recording on the computer. Specified percentage of the microstructure of martensite and bainite, participation of proeutectoid α phase in the microstructure, grain size of former β phase, the amount of dissolved κ phase.It was found that in the microstructure of bronze in the cast state, there are a number of intermetallic phases of κ type. At interphase boundaries of primary intermetallic faceted precipitates, especially rich in tungsten (IM_W, nucleate and grow dendritic primary intermetallic κI phases, with chemical composition similar to the type of Fe3Si iron silicide.Dissolved, during the heating, in the β phase are all the intermediate phase included in the microstructure, with the exception of primary intermetallic phases of tungsten and κI. Prolongation of the isothermal annealing causes coagulation and coalescence of primary phases. In microstructure of the bronze after quenching obtained the α phase precipitation on the grain boundary of secondary β phase, coarse bainite and martensite, for all annealing times. With the change of annealing time are changed the relative proportions of individual phases or their systems, in the microstructure. In the microstructure of bronze, hold at temperature of 1000°C for 60 min, after quenching martensitic microstructure was obtained with the primary phases, and the least amount of bainite.

  19. The Simplest Chronoscope V: A Theory of Dual Primary and Secondary Reaction Time Systems.

    Science.gov (United States)

    Montare, Alberto

    2016-12-01

    Extending work by Montare, visual simple reaction time, choice reaction time, discriminative reaction time, and overall reaction time scores obtained from college students by the simplest chronoscope (a falling meterstick) method were significantly faster as well as significantly less variable than scores of the same individuals from electromechanical reaction timers (machine method). Results supported the existence of dual reaction time systems: an ancient primary reaction time system theoretically activating the V5 parietal area of the dorsal visual stream that evolved to process significantly faster sensory-motor reactions to sudden stimulations arising from environmental objects in motion, and a secondary reaction time system theoretically activating the V4 temporal area of the ventral visual stream that subsequently evolved to process significantly slower sensory-perceptual-motor reactions to sudden stimulations arising from motionless colored objects. © The Author(s) 2016.

  20. A protected annealing strategy to enhanced light emission and photostability of YAG:Ce nanoparticle-based films

    Science.gov (United States)

    Revaux, Amelie; Dantelle, Geraldine; George, Nathan; Seshadri, Ram; Gacoin, Thierry; Boilot, Jean-Pierre

    2011-05-01

    A significant obstacle in the development of YAG:Ce nanoparticles as light converters in white LEDs and as biological labels is associated with the difficulty of finding preparative conditions that allow simultaneous control of structure, particle size and size distribution, while maintaining the optical properties of bulk samples. Preparation conditions frequently involve high-temperature treatments of precursors (up to 1400 °C), which result in increased particle size and aggregation, and lead to oxidation of Ce(iii) to Ce(iv). We report here a process that we term protected annealing, that allows the thermal treatment of preformed precursor particles at temperatures up to 1000 °C while preserving their small size and state of dispersion. In a first step, pristine nanoparticles are prepared by a glycothermal reaction, leading to a mixture of YAG and boehmite crystalline phases. The preformed nanoparticles are then dispersed in a porous silica. Annealing of the composite material at 1000 °C is followed by dissolution of the amorphous silica by hydrofluoric acid to recover the annealed particles as a colloidal dispersion. This simple process allows completion of YAG crystallization while preserving their small size. The redox state of Ce ions can be controlled through the annealing atmosphere. The obtained particles of YAG:Ce (60 +/- 10 nm in size) can be dispersed as nearly transparent aqueous suspensions, with a luminescence quantum yield of 60%. Transparent YAG:Ce nanoparticle-based films of micron thickness can be deposited on glass substrates using aerosol spraying. Films formed from particles prepared by the protected annealing strategy display significantly improved photostability over particles that have not been subject to such annealing.A significant obstacle in the development of YAG:Ce nanoparticles as light converters in white LEDs and as biological labels is associated with the difficulty of finding preparative conditions that allow simultaneous

  1. Experimental quantum annealing: case study involving the graph isomorphism problem.

    Science.gov (United States)

    Zick, Kenneth M; Shehab, Omar; French, Matthew

    2015-06-08

    Quantum annealing is a proposed combinatorial optimization technique meant to exploit quantum mechanical effects such as tunneling and entanglement. Real-world quantum annealing-based solvers require a combination of annealing and classical pre- and post-processing; at this early stage, little is known about how to partition and optimize the processing. This article presents an experimental case study of quantum annealing and some of the factors involved in real-world solvers, using a 504-qubit D-Wave Two machine and the graph isomorphism problem. To illustrate the role of classical pre-processing, a compact Hamiltonian is presented that enables a reduced Ising model for each problem instance. On random N-vertex graphs, the median number of variables is reduced from N(2) to fewer than N log2 N and solvable graph sizes increase from N = 5 to N = 13. Additionally, error correction via classical post-processing majority voting is evaluated. While the solution times are not competitive with classical approaches to graph isomorphism, the enhanced solver ultimately classified correctly every problem that was mapped to the processor and demonstrated clear advantages over the baseline approach. The results shed some light on the nature of real-world quantum annealing and the associated hybrid classical-quantum solvers.

  2. Annealing effects on the migration of ion-implanted cadmium in glassy carbon

    Energy Technology Data Exchange (ETDEWEB)

    Hlatshwayo, T.T., E-mail: thulani.hlatshwayo@up.ac.za [Physics Department, University of Pretoria, Pretoria (South Africa); Sebitla, L.D. [Physics Department, University of Pretoria, Pretoria (South Africa); Physics Department, University of Botswana, Gaborone (Botswana); Njoroge, E.G.; Mlambo, M.; Malherbe, J.B. [Physics Department, University of Pretoria, Pretoria (South Africa)

    2017-03-15

    The migration behaviour of cadmium (Cd) implanted into glassy carbon and the effects of annealing on radiation damage introduced by ion implantation were investigated. The glassy carbon substrates were implanted with Cd at a dose of 2 × 10{sup 16} ions/cm{sup 2} and energy of 360 keV. The implantation was performed at room temperature (RT), 430 °C and 600 °C. The RT implanted samples were isochronally annealed in vacuum at 350, 500 and 600 °C for 1 h and isothermally annealed at 350 °C up to 4 h. The as-implanted and annealed samples were characterized by Raman spectroscopy and Rutherford backscattering spectrometry (RBS). Raman results revealed that implantation at room temperature amorphized the glassy carbon structure while high temperature implantations resulted in slightly less radiation damage. Isochronal annealing of the RT implanted samples resulted in some recrystallization as a function of increasing temperature. The original glassy carbon structure was not achieved at the highest annealing temperature of 600 °C. Diffusion of Cd in glassy carbon was already taking place during implantation at 430 °C. This diffusion of Cd was accompanied by significant loss from the surface during implantation at 600 °C. Isochronal annealing of the room temperature implanted samples at 350 °C for 1 h caused Cd to diffuse towards the bulk while isothermal annealing at 500 and 600 °C resulted in the migration of implanted Cd toward the surface accompanied by a loss of Cd from the surface. Isothermal annealing at 350 °C for 1 h caused Cd to diffuse towards the bulk while for annealing time >1 h Cd diffused towards the surface. These results were interpreted in terms of trapping and de-trapping of implanted Cd by radiation damage.

  3. Simulated annealing and circuit layout

    NARCIS (Netherlands)

    Aarts, E.H.L.; Laarhoven, van P.J.M.

    1991-01-01

    We discuss the problem of approximately sotvlng circuit layout problems by simulated annealing. For this we first summarize the theoretical concepts of the simulated annealing algorithm using Ihe theory of homogeneous and inhomogeneous Markov chains. Next we briefly review general aspects of the

  4. Radiation annealing in cuprous oxide

    DEFF Research Database (Denmark)

    Vajda, P.

    1966-01-01

    Experimental results from high-intensity gamma-irradiation of cuprous oxide are used to investigate the annealing of defects with increasing radiation dose. The results are analysed on the basis of the Balarin and Hauser (1965) statistical model of radiation annealing, giving a square...

  5. Effect of Annealing on Microstructures and Hardening of Helium-Hydrogen-Implanted Sequentially Vanadium Alloys

    Science.gov (United States)

    Jiang, Shaoning; Wang, Zhiming

    2018-03-01

    The effect of post-irradiation annealing on the microstructures and mechanical properties of V-4Cr-4Ti alloys was studied. Helium-hydrogen-irradiated sequentially V-4Cr-4Ti alloys at room temperature (RT) were undergone post-irradiation annealing at 450 °C over periods of up to 30 h. These samples were carried out by high-resolution transmission electron microscopy (HRTEM) observation and nanoindentation test. With the holding time, large amounts of point defects produced during irradiation at RT accumulated into large dislocation loops and then dislocation nets which promoted the irradiation hardening. Meanwhile, bubbles appeared. As annealing time extended, these bubbles grew up and merged, and finally broke up. In the process, the size of bubbles increased and the number density decreased. Microstructural changes due to post-irradiation annealing corresponded to the change of hardening. Dislocations and bubbles are co-contributed to irradiation hardening. With the holding time up to 30 h, the recovery of hardening is not obvious. The phenomenon was discussed by dispersed barrier hardening model and Friedel-Kroupa-Hirsch relationship.

  6. Enhanced Photoelectrochemical Behavior of H-TiO2 Nanorods Hydrogenated by Controlled and Local Rapid Thermal Annealing.

    Science.gov (United States)

    Wang, Xiaodan; Estradé, Sonia; Lin, Yuanjing; Yu, Feng; Lopez-Conesa, Lluis; Zhou, Hao; Gurram, Sanjeev Kumar; Peiró, Francesca; Fan, Zhiyong; Shen, Hao; Schaefer, Lothar; Braeuer, Guenter; Waag, Andreas

    2017-12-01

    Recently, colored H-doped TiO 2 (H-TiO 2 ) has demonstrated enhanced photoelectrochemical (PEC) performance due to its unique crystalline core-disordered shell nanostructures and consequent enhanced conduction behaviors between the core-shell homo-interfaces. Although various hydrogenation approaches to obtain H-TiO 2 have been developed, such as high temperature hydrogen furnace tube annealing, high pressure hydrogen annealing, hydrogen-plasma assisted reaction, aluminum reduction and electrochemical reduction etc., there is still a lack of a hydrogenation approach in a controlled manner where all processing parameters (temperature, time and hydrogen flux) were precisely controlled in order to improve the PEC performance of H-TiO 2 and understand the physical insight of enhanced PEC performance. Here, we report for the first time a controlled and local rapid thermal annealing (RTA) approach to prepare hydrogenated core-shell H-TiO 2 nanorods grown on F:SnO 2 (FTO) substrate in order to address the degradation issue of FTO in the typical TiO 2 nanorods/FTO system observed in the conventional non-RTA treated approaches. Without the FTO degradation in the RTA approach, we systematically studied the intrinsic relationship between the annealing temperature, structural, optical, and photoelectrochemical properties in order to understand the role of the disordered shell on the improved photoelectrochemical behavior of H-TiO 2 nanorods. Our investigation shows that the improvement of PEC performance could be attributed to (i) band gap narrowing from 3.0 to 2.9 eV; (ii) improved optical absorption in the visible range induced by the three-dimensional (3D) morphology and rough surface of the disordered shell; (iii) increased proper donor density; (iv) enhanced electron-hole separation and injection efficiency due to the formation of disordered shell after hydrogenation. The RTA approach developed here can be used as a suitable hydrogenation process for TiO 2 nanorods

  7. Pattern Laser Annealing by a Pulsed Laser

    Science.gov (United States)

    Komiya, Yoshio; Hoh, Koichiro; Murakami, Koichi; Takahashi, Tetsuo; Tarui, Yasuo

    1981-10-01

    Preliminary experiments with contact-type pattern laser annealing were made for local polycrystallization of a-Si, local evaporation of a-Si and local formation of Ni-Si alloy. These experiments showed that the mask patterns can be replicated as annealed regions with a resolution of a few microns on substrates. To overcome shortcomings due to the contact type pattern annealing, a projection type reduction pattern laser annealing system is proposed for resistless low temperature pattern forming processes.

  8. Effect of Nicotine on Audio and Visual Reaction Time in Dipping ...

    African Journals Online (AJOL)

    Nicotine through blood is harmful and as there are fewer studies in India with respect to nicotines influence on reaction time especially in the smokeless tobacco users we studied this. Reaction time is a measure of the sensorimotor integration in a person. We used a PC 1000 Hz reaction timer to record the audio and visual ...

  9. Effect of Contact Time on Interface Reaction between Aluminum Silicon (7% and 11% Alloy and Steel Dies SKD 61

    Directory of Open Access Journals (Sweden)

    Bambang Suharno

    2010-10-01

    Full Text Available Die soldering (die sticking is a defect of metal casting in which molten metal “welds” to the metallic die mold surface during casting process. Die soldering is the result of an interface reaction between the molten aluminum and the die material. Aluminum alloy with 7 and 11% silicon and SKD 61 die steel are the most common melt and die material used in aluminum die casting. This research is done to study the morphology and the characteristics of the formed AlxFeySiz intermetallic layer during interface reaction at dipping test. The samples of as-anneal SKD 61 tool steel was dipped into the molten of Al-7%Si held at temperature 680oC and into molten Al-11%Si held at temperature 710oC with the different contact time of 10 minutes; 30 minutes; and 50 minutes. The research results showed that the interface reaction can form a compact intermetallic layer with AlxFey phase and a broken intermetallic layer with AlxFeySiz phase on the surface of SKD 61 tool steel. The increasing of the contact time by the immersion of material SKD 61 tool steel in both of molten Al-7%Si and Al-11%Si will increase the thickness of the AlxFeySiz intermetallic layer until an optimum point and then decreasing. The micro hardness of the AlxFeySiz intermetallic layer depends on the content of the iron. Increasing of the iron content in intermetallic layer will increase the micro hardness of the AlxFeySiz. This condition happened because the increasing of Fe content will cause forming of intermetallic AlxFeySiz phase becomes quicker.

  10. Examining the Reaction Times of International Level Badminton Players Under 15

    Directory of Open Access Journals (Sweden)

    Mehmet Fatih Yüksel

    2018-03-01

    Full Text Available This research was conducted to examine the simple visual and auditory reaction times of badminton players of the national teams and to examine the possible effects of reaction-time average values of badminton players under the age of 15 who participated in the fifth International Rumi Child Sport Games. In total, 48 players (male = 24; female = 24 from six countries (Turkey, Azerbaijan, Bulgaria, Macedonia, Serbia, Georgia participated in the study. Stature, bodyweight, BMI, dominant and non-dominant hand visual and auditory reaction time values of the participants were detected. At the end of the study, it was determined that there were statistically significant differences between the countries in terms of male dominant and non-dominant hand visual reaction values, and male dominant hand auditory reaction values. It was also determined that there were statistically significant differences between the countries in terms of female bodyweight, BMI, dominant and non-dominant hand visual reaction values, and female non-dominant hand auditory reaction values. There was statistically significant difference between female and male players with regards to dominant and non-dominant hand visual, and non-dominant hand auditory reaction values. In conclusion, it was determined that the reaction times of the top ranking countries in the fifth International Rumi Child Sport Games under-15 were at a better level, and it can be concluded that this factor played an important role for success alongside with technique and tactic features.

  11. Reduced annealing temperatures in silicon solar cells

    Science.gov (United States)

    Weinberg, I.; Swartz, C. K.

    1981-01-01

    Cells irradiated to a fluence of 5x10,000,000,000,000/square cm showed short circuit current on annealing at 200 C, with complete annealing occurring at 275 C. Cells irradiated to 100,000,000,000,000/square cm showed a reduction in annealing temperature from the usual 500 to 300 C. Annealing kinetic studies yield an activation energy of (1.5 + or - 2) eV for the low fluence, low temperature anneal. Comparison with activation energies previously obtained indicate that the presently obtained activation energy is consistent with the presence of either the divacancy or the carbon interstitial carbon substitutional pair, a result which agrees with the conclusion based on defect behavior in boron-doped silicon.

  12. Structural and chemical analysis of annealed plasma-enhanced atomic layer deposition aluminum nitride films

    Energy Technology Data Exchange (ETDEWEB)

    Broas, Mikael, E-mail: mikael.broas@aalto.fi; Vuorinen, Vesa [Department of Electrical Engineering and Automation, Aalto University, P.O. Box 13500, FIN-00076 Aalto, Espoo (Finland); Sippola, Perttu; Pyymaki Perros, Alexander; Lipsanen, Harri [Department of Micro- and Nanosciences, Aalto University, P.O. Box 13500, FIN-00076 Aalto, Espoo (Finland); Sajavaara, Timo [Department of Physics, University of Jyväskylä, P.O. Box 35, FIN-40014 Jyväskylä (Finland); Paulasto-Kröckel, Mervi [Department of Electrical Engineering and Automation, Aalto University. P.O. Box 13500, FIN-00076 Aalto, Espoo (Finland)

    2016-07-15

    Plasma-enhanced atomic layer deposition was utilized to grow aluminum nitride (AlN) films on Si from trimethylaluminum and N{sub 2}:H{sub 2} plasma at 200 °C. Thermal treatments were then applied on the films which caused changes in their chemical composition and nanostructure. These changes were observed to manifest in the refractive indices and densities of the films. The AlN films were identified to contain light element impurities, namely, H, C, and excess N due to nonideal precursor reactions. Oxygen contamination was also identified in the films. Many of the embedded impurities became volatile in the elevated annealing temperatures. Most notably, high amounts of H were observed to desorb from the AlN films. Furthermore, dinitrogen triple bonds were identified with infrared spectroscopy in the films. The triple bonds broke after annealing at 1000 °C for 1 h which likely caused enhanced hydrolysis of the films. The nanostructure of the films was identified to be amorphous in the as-deposited state and to become nanocrystalline after 1 h of annealing at 1000 °C.

  13. Effects of copolymer composition, film thickness, and solvent vapor annealing time on dewetting of ultrathin block copolymer films.

    Science.gov (United States)

    Huang, Changchun; Wen, Gangyao; Li, Jingdan; Wu, Tao; Wang, Lina; Xue, Feifei; Li, Hongfei; Shi, Tongfei

    2016-09-15

    Effects of copolymer composition, film thickness, and solvent vapor annealing time on dewetting of spin-coated polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) films (dewetting of the films with different thicknesses occur via the spinodal dewetting and the nucleation and growth mechanisms, respectively. The PS-b-PMMA films rupture into droplets which first coalesce into large ones to reduce the surface free energy. Then the large droplets rupture into small ones to increase the contact area between PMMA blocks and acetone molecules resulting from ultimate migration of PMMA blocks to droplet surface, which is a novel dewetting process observed in spin-coated films for the first time. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Annealing studies of zircaloy-2 cladding at 580-8500C

    International Nuclear Information System (INIS)

    Hindle, E.D.

    1978-05-01

    For fuel element cladding it is important to determine if prior metallurgical condition combined with irradiation damage can influence high temperature deformation, because studies of such deformation are required to produce data for the cladding ballooning models which are used in analysing loss-of-coolant accidents (LOCA). If the behaviour of all cladding conditions during a LOCA can be represented by, say, the annealed condition, then much experimental work on a multiplicity of cladding conditions can be avoided. By examining the metallographic structure and hardness, the present study determines the time required in the range 580 to 850 0 C for returning Zircaloy cladding to the annealed condition, so that for any transient, a point can be specified where the material should have annealed. An equation has been derived to give this information. (author)

  15. The influence of thermal annealing on the characteristics of Au/Ni Schottky contacts on n-type 4 H-SiC

    Science.gov (United States)

    Omotoso, E.; Auret, F. D.; Igumbor, E.; Tunhuma, S. M.; Danga, H. T.; Ngoepe, P. N. M.; Taleatu, B. A.; Meyer, W. E.

    2018-05-01

    The effects of isochronal annealing on the electrical, morphological and structural characteristics of Au/Ni/4 H-SiC Schottky barrier diodes (SBDs) have been studied. Current-voltage ( I- V), capacitance-voltage ( C- V), deep-level transient spectroscopy, scanning electron microscope (SEM) and X-ray diffraction measurements were employed to study the thermal effect on the characteristics of the SBDs. Prior to thermal annealing of Schottky contacts, the I- V measurements results confirmed the good rectification behaviour with ideality factor of 1.06, Schottky barrier height of 1.20 eV and series resistance of 7 Ω. The rectification properties after annealing was maintained up to an annealing temperature of 500 °C, but deviated slightly above 500 °C. The uncompensated ionized donor concentration decreased with annealing temperature, which could be attributed to out-diffusion of the 4 H-SiC into the Au/Ni contacts and decrease in bonding due to formation of nickel silicides. We observed the presence of four deep-level defects with energies 0.09, 0.11, 0.16 and 0.65 eV below the conduction band before and after the isochronal annealing up to 600 °C. The conclusion drawn was that annealing did not affect the number of deep-level defects present in Au/Ni/4 H-SiC contacts. The variations in electrical properties of the devices were attributed to the phase transformations and interfacial reactions that occurred after isochronal annealing.

  16. Energy Saving in Industrial Annealing Furnaces

    Directory of Open Access Journals (Sweden)

    Fatma ÇANKA KILIÇ

    2018-03-01

    Full Text Available In this study, an energy efficiency studies have been carried out in a natural gas-fired rolling mill annealing furnace of an industrial establishment. In this context, exhaust gas from the furnace has been examined in terms of waste heat potential. In the examinations that have been made in detail; waste heat potential was found as 3.630,31 kW. Technical and feasibility studies have been carried out to realize electricity production through an Organic Rankine Cycle (ORC system for evaluating the waste heat potential of the annealing furnace. It has been calculated that 1.626.378,88 kWh/year of electricity can be generated by using the exhaust gas waste heat of the annealing furnace through an ORC system to produce electric energy with a net efficiency of 16%. The financial value of this energy was determined as 436.032,18 TL/year and the simple repayment period of the investment was 8,12 years. Since the annealing period of the annealing furnace is 2800 hours/year, the investment has not been found to be feasible in terms of the feasibility studies. However, the investment suitability can be assured when the annealing furnace is operating at full capacity for 8,000 hours or more annually.

  17. Phage annealing proteins promote oligonucleotide-directed mutagenesis in Escherichia coli and mouse ES cells

    Directory of Open Access Journals (Sweden)

    Muyrers Joep PP

    2003-01-01

    Full Text Available Abstract Background The phage protein pairs, RecE/RecT from Rac or Redα/Redβ from λ, initiate efficient double strand break repair (DSBR in Escherichia coli that has proven very useful for DNA engineering. These phage pairs initiate DSBR either by annealing or by another mechanism that is not defined. Results Here we report that these proteins also mediate single strand oligonucleotide repair (ssOR at high efficiencies. The ssOR activity, unlike DSBR, does not require a phage exonuclease (RecE or Redα but only requires a phage annealing protein (RecT or Redβ. Notably, the P22 phage annealing protein Erf, which does not mediate the same DSBR reactions, also delivers ssOR activity. By altering aspects of the oligonucleotides, we document length and design parameters that affect ssOR efficiency to show a simple relationship to homologies either side of the repair site. Notably, ssOR shows strand bias. Oligonucleotides that can prime lagging strand replication deliver more ssOR than their leading complements. This suggests a model in which the annealing proteins hybridize the oligonucleotides to single stranded regions near the replication fork. We also show that ssOR is a highly efficient way to engineer BACs and can be detected in a eukaryotic cell upon expression of a phage annealing protein. Conclusion Phage annealing proteins can initiate the recombination of single stranded oligonucleotides into endogenous targets in Escherichia coli at very high efficiencies. This expands the repertoire of useful DNA engineering strategies, shows promise for applications in eukaryotic cells, and has implications for the unanswered questions regarding DSBR mediated by RecE/RecT and Redα/Redβ.

  18. Annealing Effect on Corrosion Behavior of the Beta-Quenched HANA Alloy

    International Nuclear Information System (INIS)

    Kim, Hyun Gil; Kim, Il Hyun; Choi, Byung Kwan; Park, Sang Yoon; Park, Jeong Yong; Jeong, Yong Hwan

    2009-01-01

    The advanced fuel cladding materials named as HANA cladding have been developed at KAERI for application of high burn-up and that cladding showed an improved performance in both in-pile and out-of-pile conditions. However, the cladding performance could be changed by the annealing conditions during the tube manufacturing process. Especially, the corrosion resistance is considerably sensitive to their microstructure which is determined by a manufacturing process in the high Nb-containing zirconium alloys. They reported that the corrosion properties of the Nb-containing Zr alloys were considerably affected by the microstructure conditions such as the Nb concentration in the matrix and the second phase types. Therefore, the corrosion behavior of HANA cladding having the high Nb could be considerably affected by the annealing time and temperatures. The purpose of this study is focused on the annealing effect of the beta quenched HANA alloy to obtain the optimum annealing conditions

  19. Annealing of radiation damage in 0.1- and 2-ohm-centimeter Silicon solar cells

    Science.gov (United States)

    Weinberg, I.; Swartz, C. K.

    1979-01-01

    Isochronal and isothermal annealing studies were conducted on 0.1 and 2 ohm centimeter n(+)/p silicon cells after irradiation by 1 MeV electrons at fluences of 10 to the 14th power, 5 times 10 to the 14th power, and 10 to the 15th power per square centimeter. For the 0.1 ohm centimeter cells, reverse annealing was not observed in the isochronal data. However, reverse annealing was observed between approximately 200 and 325 C in the isochronal data of the 2 ohm centimeter cells. Isothermal annealing of 0.1 ohm centimeter cells at 500 C restored pre-irradiation maximum power P sub max within 20 minutes at fluence = 10 to the 14th power, in 180 minutes at fluence = 5 times 10 to the 14th power and to 92 percent of pre-irradiation P sub max in 180 minutes for fluence = 10 to the 15th power. Annealing at 450 C was found inadequate to restore 0.1 ohm centimeter cell performance within reasonable times for all fluence levels. By comparison, at 450 C, the P sub max of 2 ohm centimeter cells was restored within 45 minutes, for the two highest fluence levels, while for the lowest fluence, restoration was completed within 15 minutes. Spectral response data indicate that, for both resistivities, degradation occurs predominantly in the cells p-type base region.

  20. Electrophysiological Correlates of Changes in Reaction Time Based on Stimulus Intensity

    Science.gov (United States)

    Lakhani, Bimal; Vette, Albert H.; Mansfield, Avril; Miyasike-daSilva, Veronica; McIlroy, William E.

    2012-01-01

    Background Although reaction time is commonly used as an indicator of central nervous system integrity, little is currently understood about the mechanisms that determine processing time. In the current study, we are interested in determining the differences in electrophysiological events associated with significant changes in reaction time that could be elicited by changes in stimulus intensity. The primary objective is to assess the effect of increasing stimulus intensity on the latency and amplitude of afferent inputs to the somatosensory cortex, and their relation to reaction time. Methods Median nerve stimulation was applied to the non-dominant hand of 12 healthy young adults at two different stimulus intensities (HIGH & LOW). Participants were asked to either press a button as fast as possible with their dominant hand or remain quiet following the stimulus. Electroencephalography was used to measure somatosensory evoked potentials (SEPs) and event related potentials (ERPs). Electromyography from the flexor digitorum superficialis of the button-pressing hand was used to assess reaction time. Response time was the time of button press. Results Reaction time and response time were significantly shorter following the HIGH intensity stimulus compared to the LOW intensity stimulus. There were no differences in SEP (N20 & P24) peak latencies and peak-to-peak amplitude for the two stimulus intensities. ERPs, locked to response time, demonstrated a significantly larger pre-movement negativity to positivity following the HIGH intensity stimulus over the Cz electrode. Discussion This work demonstrates that rapid reaction times are not attributable to the latency of afferent processing from the stimulated site to the somatosensory cortex, and those latency reductions occur further along the sensorimotor transformation pathway. Evidence from ERPs indicates that frontal planning areas such as the supplementary motor area may play a role in transforming the elevated sensory

  1. Interlayer growth in Mo/B4C multilayered structures upon thermal annealing

    International Nuclear Information System (INIS)

    Nyabero, S. L.; Kruijs, R. W. E. van de; Yakshin, A. E.; Zoethout, E.; Bosgra, J.; Loch, R. A.; Blanckenhagen, G. von; Bijkerk, F.

    2013-01-01

    Both multilayer period thickness expansion and compaction were observed in Mo/B 4 C multilayers upon annealing, and the physical causes for this were explored in detail. Using in situ time-dependent grazing incidence X-ray reflectometry, period changes down to picometer-scale were resolved. It was shown that the changes depend on the thickness of the B 4 C layers, annealing temperature, and annealing time. Although strong stress relaxation during annealing was observed, it was excluded as a cause for period expansion. Auger electron spectroscopy and wide angle X-ray diffraction measurements revealed the growth of interlayers, with associated period changes influenced by the supply of B and C atoms to the growing compound interlayers. For multilayers with a Mo thickness of 3 nm, two regimes were recognized, depending on the deposited B 4 C thickness: in multilayers with B 4 C ≤ 1.5 nm, the supply of additional Mo into the already formed MoB x C y interlayer was dominant and led to densification, resulting in period compaction. For multilayers with B 4 C ≥ 2 nm, the B and C enrichment of interlayers formed low density compounds and yielded period expansion.

  2. Resistivity behavior in isothermal annealing of Pd-H(D) alloys around 50 K

    International Nuclear Information System (INIS)

    Yamakawa, Kohji; Maeta, Hiroshi

    2004-01-01

    The behavior of electrical resistivity during hydrogen (deuterium) ordering is investigated for Pd-H(D) alloys of various hydrogen concentrations around 50 K. The disordered hydrogen (deuterium) atoms are introduced by quenching from 100 K into liquid helium immediately before isothermal annealings. The disordered atoms order by migration of the atoms during the heating-up of the specimens. On the isothermal curves of the resistivity in the high temperature range, the resistivity increases at first and then adopts a constant value dependent on the annealing temperature. On the other hand, the resistivity increases and then decreases during isothermal annealing in the low temperature range, nevertheless the ordering is progressing. The annealing time, at which the resistivity maximum appears, and the resistivity value of the maximum increase with decreasing annealing temperature. Furthermore, the decreasing resistivity after the maximum saturates to a value dependent on each annealing temperature. Therefore, it becomes clear that an equilibrium amount of ordering depends on the temperature and the resistivity increases in the early stage of hydrogen (deuterium) ordering and decreases in the later stage. The resistivity maximum in the isothermal annealing curve is caused by the nucleation and growth of ordered domains of hydrogen (deuterium) atoms

  3. A proposal simulated annealing algorithm for proportional parallel flow shops with separated setup times

    Directory of Open Access Journals (Sweden)

    Helio Yochihiro Fuchigami

    2014-08-01

    Full Text Available This article addresses the problem of minimizing makespan on two parallel flow shops with proportional processing and setup times. The setup times are separated and sequence-independent. The parallel flow shop scheduling problem is a specific case of well-known hybrid flow shop, characterized by a multistage production system with more than one machine working in parallel at each stage. This situation is very common in various kinds of companies like chemical, electronics, automotive, pharmaceutical and food industries. This work aimed to propose six Simulated Annealing algorithms, their perturbation schemes and an algorithm for initial sequence generation. This study can be classified as “applied research” regarding the nature, “exploratory” about the objectives and “experimental” as to procedures, besides the “quantitative” approach. The proposed algorithms were effective regarding the solution and computationally efficient. Results of Analysis of Variance (ANOVA revealed no significant difference between the schemes in terms of makespan. It’s suggested the use of PS4 scheme, which moves a subsequence of jobs, for providing the best percentage of success. It was also found that there is a significant difference between the results of the algorithms for each value of the proportionality factor of the processing and setup times of flow shops.

  4. Time-temperature-sensitization and time-temperature-precipitation behavior of alloy 625

    International Nuclear Information System (INIS)

    Koehler, M.; Heubner, U.

    1996-01-01

    Time-Temperature-Sensitization diagrams have been established for a low-carbon version of alloy 625 (UNS N06625). Sensitization in terms of a 50 microm (2 mils) intergranular penetration criterion starts after about 3 h aging time at 750 C (soft annealed condition) or after less than 1 h aging time at 800 C (solution annealed condition) when tested according to ASTM-G 28 method A. Grain boundary precipitation of carbides occurs during aging of both the soft annealed and the solution annealed material, but the soft annealed material exhibits a more pronounced general precipitation of Ni 3 (Nb,Mo) phase giving rise to more distinct loss of ductility. Sensitization of alloy 625 may be retarded by lowering its iron content

  5. Influence of deposition parameters and annealing on Cu2ZnSnS4 thin films grown by SILAR

    International Nuclear Information System (INIS)

    Patel, Kinjal; Shah, Dimple V.; Kheraj, Vipul

    2015-01-01

    Highlights: • Optimisation of Cu 2 ZnSnS 4 (CZTS) thin film deposition using SILAR method. • Study on effects of annealing at different temperature under two different ambients, viz. sulphur and tin sulphide. • Formation of CZTS thin films with good crystalline quality confirmed by XRD and Raman spectra. - Abstract: Cu 2 ZnSnS 4 (CZTS) thin films were deposited on glass substrates using Successive Ionic Layer Adsorption and Reaction (SILAR) technique at the room-temperature. The deposition parameters such as concentration of precursors and number of cycles were optimised for the deposition of uniform CZTS thin films. Effects of annealing at different temperature under two different ambient, viz. sulphur and tin sulphide have also been investigated. The structural and optical properties of the films were studied using X-ray diffraction, scanning electron microscopy, Raman spectroscopy and UV-visible spectra in light with the deposition parameters and annealing conditions. It is observed that a good quality CZTS film can be obtained by SILAR at room temperature followed by annealing at 500 °C in presence of sulphur

  6. Chromium depletion from stainless steels during vacuum annealing

    International Nuclear Information System (INIS)

    Smith, A.F.; Hales, R.

    1977-01-01

    During selective chromium oxidation of stainless steels the changes in chromium concentration at the metal surface and in the metal have an important bearing on the overall oxidation performance. It has been proposed that an analogue of chromium behaviour during selective oxidation is obtained from volatilisation of chromium during high temperature vacuum annealing. In the present report the evaporation of chromium from 316 type of steel, vacuum annealed at 1,000 0 C, has been investigated by means of energy dispersive X-ray analysis and by neutron activation analysis. It was established that chromium loss from austenitic stainless steels is rate controlled by interdiffusion in the alloy. As predicted the chromium concentration at the metal surface decreased with increasing vacuum annealing time. The chromium depletion profile in the metal was in good agreement with the previously derived model apart from an anomalous region near the surface. Here the higher resolution of the neutron activation technique indicated a zone within approximately 2μm of the surface where the chromium concentration decreased more steeply than expected. (orig.) [de

  7. Temperature Scaling Law for Quantum Annealing Optimizers.

    Science.gov (United States)

    Albash, Tameem; Martin-Mayor, Victor; Hen, Itay

    2017-09-15

    Physical implementations of quantum annealing unavoidably operate at finite temperatures. We point to a fundamental limitation of fixed finite temperature quantum annealers that prevents them from functioning as competitive scalable optimizers and show that to serve as optimizers annealer temperatures must be appropriately scaled down with problem size. We derive a temperature scaling law dictating that temperature must drop at the very least in a logarithmic manner but also possibly as a power law with problem size. We corroborate our results by experiment and simulations and discuss the implications of these to practical annealers.

  8. Choice reaction time in patients with post-operative cognitive dysfunction

    DEFF Research Database (Denmark)

    Steinmetz, J.; Rasmussen, L.S.

    2008-01-01

    BACKGROUND: Post-operative cognitive dysfunction (POCD) is detected by administration of a neuropsychological test battery. Reaction time testing is at present not included as a standard test. Choice reaction time (CRT) data from the first International Study of Post-operative Cognitive Dysfunction...... in nine countries. CRT was measured 52 times using the four boxes test. Patients performed the test before surgery (n=1083), at 1 week (n=926) and at 3 months (n=852) post-operatively. CRT for the individual patient was determined as the median time of correct responses. The usefulness of the CRT...... had a significantly longer CRT. ROC curves revealed that a reaction time of 813 ms was the most appropriate cut-off at 1 week and 762 ms at 3 months but the positive predictive value for POCD was low: 34.4% and 14.7%, respectively. CONCLUSIONS: Post-operative cognitive dysfunction is associated...

  9. Decorative properties of annealed Ti N coatings

    International Nuclear Information System (INIS)

    Klubovich, V.V.; Rubanik, V.V.; Bagrets, D.A.

    2012-01-01

    The decorative properties of annealed TiN coatings on austenitic stainless steel which were formed by vacuum-arc deposition wen investigated. It was shown the principal possibility to control colour characteristics of TiN films due to heat treatment at different temperature and time that expand their usage as decorative coatings. (authors).

  10. Infrared thermal annealing device

    International Nuclear Information System (INIS)

    Gladys, M.J.; Clarke, I.; O'Connor, D.J.

    2003-01-01

    A device for annealing samples within an ultrahigh vacuum (UHV) scanning tunneling microscopy system was designed, constructed, and tested. The device is based on illuminating the sample with infrared radiation from outside the UHV chamber with a tungsten projector bulb. The apparatus uses an elliptical mirror to focus the beam through a sapphire viewport for low absorption. Experiments were conducted on clean Pd(100) and annealing temperatures in excess of 1000 K were easily reached

  11. Aqueous chemical growth of Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films: Air annealing and photoelectrochemical properties

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, N.M.; Deshmukh, P.R.; Patil, S.V. [Thin Film Physics Laboratory, Department of Physics, Shivaji University, Kolhapur 416004, M.S. (India); Lokhande, C.D., E-mail: l_chandrakant@yahoo.com [Thin Film Physics Laboratory, Department of Physics, Shivaji University, Kolhapur 416004, M.S. (India)

    2013-05-15

    Highlights: ► Facile and efficient route for synthesis of CZTS film. ► Effect of annealing on structural, morphological and electrical properties of CZTS films. ► Solar cell study. - Abstract: In present investigation, Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films have been deposited on to glass substrates by novel chemical successive ionic layer adsorption and reaction (SILAR) method. The effect of air annealing in the temperature range between 573 and 773 K on the structural, morphological, optical and electrical properties has been studied. The X-ray diffraction studies revealed the formation of polycrystalline CZTS films. The surface morphological study showed smooth, compact and uniform film formation after annealing formation. The band gap was in between range from 1.5 to 1.8 eV depending on annealing temperature. The thermo emf measurement revealed that the CZTS exhibits p-type electrical conductivity. Further, photoactivity of CZTS thin films was tested by forming the photoelectrochemical cell.

  12. Simulated annealing model of acupuncture

    Science.gov (United States)

    Shang, Charles; Szu, Harold

    2015-05-01

    The growth control singularity model suggests that acupuncture points (acupoints) originate from organizers in embryogenesis. Organizers are singular points in growth control. Acupuncture can cause perturbation of a system with effects similar to simulated annealing. In clinical trial, the goal of a treatment is to relieve certain disorder which corresponds to reaching certain local optimum in simulated annealing. The self-organizing effect of the system is limited and related to the person's general health and age. Perturbation at acupoints can lead a stronger local excitation (analogous to higher annealing temperature) compared to perturbation at non-singular points (placebo control points). Such difference diminishes as the number of perturbed points increases due to the wider distribution of the limited self-organizing activity. This model explains the following facts from systematic reviews of acupuncture trials: 1. Properly chosen single acupoint treatment for certain disorder can lead to highly repeatable efficacy above placebo 2. When multiple acupoints are used, the result can be highly repeatable if the patients are relatively healthy and young but are usually mixed if the patients are old, frail and have multiple disorders at the same time as the number of local optima or comorbidities increases. 3. As number of acupoints used increases, the efficacy difference between sham and real acupuncture often diminishes. It predicted that the efficacy of acupuncture is negatively correlated to the disease chronicity, severity and patient's age. This is the first biological - physical model of acupuncture which can predict and guide clinical acupuncture research.

  13. Nuclide creation and annealing reactor waste in neutron fields

    International Nuclear Information System (INIS)

    Kondrat'ev, V.N.; Kadenko, I.M.

    2007-01-01

    We consider chemical elements in the Universe (their properties and transmutations) as a fuel powering an evolution of stars, galaxies, etc. The nuclear fusion reactions represent an energy source of stars and, in particular, the Sun fitting the life on the Earth. This brings a question on an origin and conditions for creation of life. We discuss some specific features of nuclear reaction chains at the hydrostatic burning of nuclides in stars and treaties for development of thermonuclear fusion reactors at the Earth based environment. The nova and supernova give promising astrophysical site candidates for synthesis of heavy atomic nuclei and renewing other nuclear components. Such an explosive nucleosynthesis yields the actinides containing basic fuel for nuclear fission reactors, among others. We briefly outline the e-, s-, and r-processes while accounting for ultra-strong stellar magnetization, and discuss some ideas for annealing the radioactive toxic nuclear waste

  14. Annealing effect on the microstructure and magnetic properties of 14%Cr-ODS ferritic steel

    International Nuclear Information System (INIS)

    Ding, H.L.; Gao, R.; Zhang, T.; Wang, X.P.; Fang, Q.F.; Liu, C.S.

    2015-01-01

    Graphical abstract: TEM images of microstructure for 14%Cr-ODS ferritic steel annealed for 2 h at different temperatures: (a) 600 °C, (b) 800 °C, (c) 950 °C, and (d) 1150 °C, and the evolution trends of coercivity field (H_C) and Vickers microhardness for samples annealed at above temperatures for 2 h and 50 h. - Highlights: • The thermal stability of annealed 14%Cr-ODS ferritic steel was investigated. • The particle size keeps fairly constant with increasing annealing temperature. • The grain size is still 2–4 μm even after annealing for 50 h at 1150 °C. • The hardness and H_C are almost unchanged after annealing from 800 °C to 1150 °C. - Abstract: The microstructure and magnetic properties of the 14%Cr oxide dispersion strengthened (ODS) ferritic steel fabricated by sol–gel and HIP method were investigated by annealing in vacuum for 2 h (at 300, 600, 800, 950 and 1150 °C) and 50 h (at 600, 800, 950 and 1150 °C). Microstructure analysis shows that as the annealing temperature increases, the size of oxide nanoparticles becomes smaller and their dispersion in matrix becomes more homogeneous. Grain size remains stable when the annealing temperature is below 800 °C, while above 800 °C, grain size grows with the increasing annealing temperature and time. The Vickers microhardness and coercivity (H_C) display almost similar evolution trend with annealing temperature for 2 h and 50 h. No obvious recrystallization appears after 1150 °C annealing, which indicates the high microstructural stability of 14%Cr-ODS ferritic steel. The possible mechanism for above behaviors is discussed in this paper.

  15. High-temperature stability of chemically vapor-deposited tungsten-silicon couples rapid thermal annealed in ammonia and argon

    International Nuclear Information System (INIS)

    Broadbent, E.K.; Morgan, A.E.; Flanner, J.M.; Coulman, B.; Sadana, D.K.; Burrow, B.J.; Ellwanger, R.C.

    1988-01-01

    A rapid thermal anneal (RTA) in an NH 3 ambient has been found to increase the thermal stability of W films chemically vapor deposited (CVD) on Si. W films deposited onto single-crystal Si by low-pressure CVD were rapid thermal annealed at temperatures between 500 and 1100 0 C in NH 3 and Ar ambients. The reactions were studied using Rutherford backscattering spectrometry, x-ray diffraction, Auger electron spectroscopy, transmission electron microscopy, and four-point resistivity probe. High-temperature (≥1000 0 C) RTA in Ar completely converted W into the low resistivity (31 μΩ cm) tetragonal WSi 2 phase. In contrast, after a prior 900 0 C RTA in NH 3 , N inclusion within the W film and at the W/Si interface almost completely suppressed the W-Si reaction. Detailed examination, however, revealed some patches of WSi 2 formed at the interface accompanied by long tunnels extending into the substrate, and some crystalline precipitates in the substrate close to the interface. The associated interfacial contact resistance was only slightly altered by the 900 0 C NH 3 anneal. The NH 3 -treated W film acted as a diffusion barrier in an Al/W/Si contact metallurgy up to at least 550 0 C, at which point some increase in contact resistance was measured

  16. Boosting quantum annealer performance via sample persistence

    Science.gov (United States)

    Karimi, Hamed; Rosenberg, Gili

    2017-07-01

    We propose a novel method for reducing the number of variables in quadratic unconstrained binary optimization problems, using a quantum annealer (or any sampler) to fix the value of a large portion of the variables to values that have a high probability of being optimal. The resulting problems are usually much easier for the quantum annealer to solve, due to their being smaller and consisting of disconnected components. This approach significantly increases the success rate and number of observations of the best known energy value in samples obtained from the quantum annealer, when compared with calling the quantum annealer without using it, even when using fewer annealing cycles. Use of the method results in a considerable improvement in success metrics even for problems with high-precision couplers and biases, which are more challenging for the quantum annealer to solve. The results are further enhanced by applying the method iteratively and combining it with classical pre-processing. We present results for both Chimera graph-structured problems and embedded problems from a real-world application.

  17. The kinetics of isothermal annealing of gamma-irradiation damage in crystalline barium nitrate

    International Nuclear Information System (INIS)

    Nair, S.M.K.; Krishnan, M.S.; James, C.

    1983-01-01

    The annealing of #betta#-irradiation damage in crystalline barium nitrate at different temperatures in the range 370 to 430 deg C is a combination of a first-order process affecting a small portion of the fragments and a second-order process, with a higher energy of activation, governing the behaviour of the remainder approx. 73%. The annealing data have been analysed on the models for simple interstitial vacancy recombination and also as a combination of a first-order and second-order process with an energy of activation of 10.9 and 24.0 kcal mole - 1 respectively. It is considered that the first-order process is the combination of close-correlated pairs of O and NO 2- fragments and the second order process involves the single reaction of random recombination of the fragments throughout the crystal. (author)

  18. Effect of thermal annealing on electron spin relaxation of beryllium-doped In0.8Ga0.2As0.45P0.55 bulk

    Directory of Open Access Journals (Sweden)

    Hao Wu

    2016-08-01

    Full Text Available The effect of thermal annealing on the electron spin relaxation of beryllium-doped In0.8Ga0.2As0.45P0.55 bulk was investigated by time-resolved spin-dependent pump and probe reflection measurement with a high time resolution of 200 fs. Three similar InGaAsP samples were examined one of which was annealed at 800 °C for 1 s, one was annealed at 700 °C for 1 s and the other was not annealed after crystal growth by molecular beam epitaxy. Although the carrier lifetimes of the 700 °C-annealed sample and the unannealed sample were similar, that of the 800 °C-annealed sample was extended to 11.6 (10.4 ns at 10 (300 K, which was more than two (four times those of the other samples. However, interestingly the spin relaxation time of the 800 °C-annealed sample was found to be similar to those of the other two samples. Particularly at room temperature, the spin relaxation times are 143 ps, 147 ps, and 111 ps for the 800 °C-annealed sample, 700 °C-annealed sample, and the unannealed sample, respectively.

  19. Stress-induced leakage current characteristics of PMOS fabricated by a new multi-deposition multi-annealing technique with full gate last process

    International Nuclear Information System (INIS)

    Wang Yanrong; Yang Hong; Xu Hao; Luo Weichun; Qi Luwei; Zhang Shuxiang; Wang Wenwu; Zhu Huilong; Zhao Chao; Chen Dapeng; Ye Tianchun; Yan Jiang

    2017-01-01

    In the process of high- k films fabrication, a novel multi deposition multi annealing (MDMA) technique is introduced to replace simple post deposition annealing. The leakage current decreases with the increase of the post deposition annealing (PDA) times. The equivalent oxide thickness (EOT) decreases when the annealing time(s) change from 1 to 2. Furthermore, the characteristics of SILC (stress-induced leakage current) for an ultra-thin SiO 2 /HfO 2 gate dielectric stack are studied systematically. The increase of the PDA time(s) from 1 to 2 can decrease the defect and defect generation rate in the HK layer. However, increasing the PDA times to 4 and 7 may introduce too much oxygen, therefore the type of oxygen vacancy changes. (paper)

  20. Rapid thermal annealing of phosphorus implanted silicon

    International Nuclear Information System (INIS)

    Lee, Y.H.; Pogany, A.; Harrison, H.B.; Williams, J.S.

    1985-01-01

    Rapid thermal annealing (RTA) of phosphorus-implanted silicon has been investigated by four point probe, Van der Pauw methods and transmission electron microscopy. The results have been compared to furnace annealing. Experiments show that RTA, even at temperatures as low as 605 deg C, results in good electrical properties with little remnant damage and compares favourably with furnace annealing

  1. Texture evolution in Fe-3% Si steel treated under unconventional annealing conditions

    International Nuclear Information System (INIS)

    Stoyka, Vladimir; Kovac, Frantisek; Stupakov, Oleksandr; Petryshynets, Ivan

    2010-01-01

    The present work investigates texture evolution stages in grain-oriented steel heat-treated using unconventional conditions. The Fe-3%Si steel taken after final cold rolling reduction from an industrial line was subjected to a laboratory isothermal annealing at different temperatures. The annealing temperatures were varied in a range of 850-1150 deg. C. During the annealing each specimen was heated at 10 deg. C/s and kept at the stated temperature for 5 min. Development of microstructure and texture in the annealed specimens were followed by the DC measurements of magnetic properties. The grain oriented steel, taken from the same industrial line after final box annealing was also analyzed and compared with the laboratory annealed specimens. It was shown that there is an optimal temperature region that, with combination of a fast heating rate, led to the best conditions of a drastically reduced development time of the {110} crystallographic texture in the cold rolled grain-oriented steel. Materials heat treated below the optimum temperature region account for a primary recrystallization, while applying heat above this region leads to a secondary recrystallization without abnormal grain growth. Moreover, in the optimum temperature range, there was a particular temperature leading to the most optimal microstructure and texture. The magnetic properties, measured after the optimal heat treatment, were close to that measured on specimens taken after the final box annealing. The electron back scattered diffraction measurement technique revealed that sharpness of the {110} crystallographic texture, developed at the optimum temperature is comparable to the steel taken after the industrial final box annealing. This fact is evidence that there is a temperature where the abnormal grain growth proceeds optimally.

  2. Effect of High-Temperature Annealing on Ion-Implanted Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Hyunpil Boo

    2012-01-01

    Full Text Available P-type and n-type wafers were implanted with phosphorus and boron, respectively, for emitter formation and were annealed subsequently at 950∼1050∘C for 30∼90 min for activation. Boron emitters were activated at 1000∘C or higher, while phosphorus emitters were activated at 950∘C. QSSPC measurements show that the implied Voc of boron emitters increases about 15 mV and the J01 decreases by deep junction annealing even after the activation due to the reduced recombination in the emitter. However, for phosphorus emitters the implied Voc decreases from 622 mV to 560 mV and the J01 increases with deep junction annealing. This is due to the abrupt decrease in the bulk lifetime of the p-type wafer itself from 178 μs to 14 μs. PC1D simulation based on these results shows that, for p-type implanted solar cells, increasing the annealing temperature and time abruptly decreases the efficiency (Δηabs=−1.3%, while, for n-type implanted solar cells, deep junction annealing increases the efficiency and Voc, especially (Δηabs=+0.4% for backside emitter solar cells.

  3. Effect of solution annealing temperature on precipitation in 2205 duplex stainless steel

    International Nuclear Information System (INIS)

    Kashiwar, A.; Vennela, N. Phani; Kamath, S.L.; Khatirkar, R.K.

    2012-01-01

    1050 °C. ► σ Phase precipitated preferentially in the samples solution annealed at 1100 °C. ► For SA at 1050 °C, the sequence of precipitation was carbides → χ phase → σ phase. ► For SA at 1100 °C, σ phase precipitated via the eutectoid reaction: ferrite (F) → σ + γ 2 .

  4. Effect of solution annealing temperature on precipitation in 2205 duplex stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Kashiwar, A., E-mail: akashiwar@gmail.com [Department of Metallurgical and Materials Engineering, Visvesvaraya National Institute of Technology (VNIT), South Ambazari Road, Nagpur-440010, Maharashtra (India); Vennela, N. Phani, E-mail: phanivennela@gmail.com [Department of Metallurgical and Materials Engineering, Visvesvaraya National Institute of Technology (VNIT), South Ambazari Road, Nagpur-440010, Maharashtra (India); Kamath, S.L., E-mail: kamath@iitb.ac.in [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay (IITB), Powai, Mumbai-400076, Maharashtra (India); Khatirkar, R.K., E-mail: rajesh.khatirkar@gmail.com [Department of Metallurgical and Materials Engineering, Visvesvaraya National Institute of Technology (VNIT), South Ambazari Road, Nagpur-440010, Maharashtra (India)

    2012-12-15

    : Black-Right-Pointing-Pointer Effect of solution annealing temperature on microstructural evolution is studied. Black-Right-Pointing-Pointer {chi} Phase precipitated preferentially in the samples solution annealed at 1050 Degree-Sign C. Black-Right-Pointing-Pointer {sigma} Phase precipitated preferentially in the samples solution annealed at 1100 Degree-Sign C. Black-Right-Pointing-Pointer For SA at 1050 Degree-Sign C, the sequence of precipitation was carbides {yields} {chi} phase {yields} {sigma} phase. Black-Right-Pointing-Pointer For SA at 1100 Degree-Sign C, {sigma} phase precipitated via the eutectoid reaction: ferrite (F) {yields} {sigma} + {gamma}{sub 2}.

  5. Computational Multiqubit Tunnelling in Programmable Quantum Annealers

    Science.gov (United States)

    2016-08-25

    ARTICLE Received 3 Jun 2015 | Accepted 26 Nov 2015 | Published 7 Jan 2016 Computational multiqubit tunnelling in programmable quantum annealers...state itself. Quantum tunnelling has been hypothesized as an advantageous physical resource for optimization in quantum annealing. However, computational ...qubit tunnelling plays a computational role in a currently available programmable quantum annealer. We devise a probe for tunnelling, a computational

  6. The influence of ingot annealing on the corrosion resistance of a PrFeCoBNbP alloy

    International Nuclear Information System (INIS)

    Oliveira, M.C.L.; Takiishi, H.; Faria, R.N.; Costa, I.

    2008-01-01

    The influence of the annealing time on the corrosion resistance of a Pr-Fe-Co-B-Nb alloy with the addition of 0.1 wt% P was investigated here using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The cast ingot alloys were annealed at 1100 deg. C for 10, 15 and 20 h. The specimens were immersed for 30 days in naturally aerated 0.02 M Na 2 HPO 4 solution at room temperature, during which period the evolution of the electrochemical behavior was assessed using EIS. The results indicated that the corrosion resistance of the Pr 14 Fe bal Co 16 B 6 Nb 0.1 P 0.25 alloy was related to the annealing time and, hence, to its microstructure. Annealing at 1100 deg. C for 10 h was insufficient to eliminate the Fe-α phase from the alloy microstructure, whereas annealing for 15 and 20 h removed an increasing amount of Fe-α phase, thereby increasing the alloy's corrosion resistance

  7. SAGRAD: A Program for Neural Network Training with Simulated Annealing and the Conjugate Gradient Method.

    Science.gov (United States)

    Bernal, Javier; Torres-Jimenez, Jose

    2015-01-01

    SAGRAD (Simulated Annealing GRADient), a Fortran 77 program for computing neural networks for classification using batch learning, is discussed. Neural network training in SAGRAD is based on a combination of simulated annealing and Møller's scaled conjugate gradient algorithm, the latter a variation of the traditional conjugate gradient method, better suited for the nonquadratic nature of neural networks. Different aspects of the implementation of the training process in SAGRAD are discussed, such as the efficient computation of gradients and multiplication of vectors by Hessian matrices that are required by Møller's algorithm; the (re)initialization of weights with simulated annealing required to (re)start Møller's algorithm the first time and each time thereafter that it shows insufficient progress in reaching a possibly local minimum; and the use of simulated annealing when Møller's algorithm, after possibly making considerable progress, becomes stuck at a local minimum or flat area of weight space. Outlines of the scaled conjugate gradient algorithm, the simulated annealing procedure and the training process used in SAGRAD are presented together with results from running SAGRAD on two examples of training data.

  8. The effects of different heat treatment annealing on structural properties of LaFe11.5Si1.5 compound

    Science.gov (United States)

    Norizan, Yang Nurhidayah Asnida; Din, Muhammad Faiz Md; Zamri, Wan Fathul Hakim W.; Hashim, Fakroul Ridzuan; Jusoh, Mohd Taufik; Rahman, Mohd Rashid Abdul

    2018-02-01

    The cubic NaZn13-type LaFe13-xSix based compounds have been studied systematically and has become one of the most interesting systems for exploring large MCE. Its magnetic properties are strongly doping dependent and provides many of advantage compare to other as magnetic materials for magnetic refrigerator application. In other to produce high quality of cubic NaZn13-type structure, the structural properties of LaFe11.5Si1.5 compounds annealed at different temperature have been investigated. The LaFe11.5Si1.5 compounds was prepared by arc melting and annealed at two different heat treatment which are 1323 K for 14 days and 1523 K for 4 hour. The powder X-ray diffraction (XRD) shows that a short time and high temperature annealing process has benefits for the formation of the NaZn13-type phase compared to a long time and low temperature annealing process. This is shown by the weight fraction of cubic NaZn13- type structure increases from 80% for low temperature annealing to 83% for high temperature annealing. At the same time, high temperature annealing increase the main structure and decrease the impurity (α-Fe and LaFeSi). Furthermore, it can be clearly seen in the Rietveld refinement results that the lattice parameter is increase at the high temperature annealing because of more cubic NaZn13 is formed at higher temperature.

  9. Superheated steam annealing of pressurized water reactor vessel

    International Nuclear Information System (INIS)

    Porowski, J.S.

    1993-01-01

    Thermal annealing of an embrittled Reactor Pressure Shell is the only recognized means for recovering material properties lost due to long-term exposure of the reactor walls to radiation. Reduced toughness of the material during operation is a major concern in evaluations of structural integrity of older reactors. Extensive studies performed within programs related to life extension of nuclear plants have confirmed that the thermal treatment of 850 deg. F for 168 hours on irradiated material essentially recovers material properties lost due to neutron exposure. Dry and wet annealing methods have been considered. Wet annealing involves operating the reactor at near design temperatures and pressures. Since the temperature of wet annealing must be limited to vessel design temperature of 650 deg. F, only partial recovery of the lost properties is achieved. Thus dry annealing was selected as an alternative for future development and industrial implementation to extend the safe life of reactors. Dry thermal annealing consists of heating portions of the reactor vessel at a specific temperature for a given period of time using a high temperature heat source. The use of spent fuel assemblies, induction heating and resistance heating elements as well as the circulation of heated fluid were investigated as potential candidate methods. To date the use of resistance heating elements which are lowered into a dry empty reactor was considered to be the preferred method. In-depth research in the United States and practical applications of such a method in Russia have confirmed feasibility of the method. The method of using circulating superheated steam to anneal the vessel at 850 deg. F without complete removal of the reactor internals is described herein. After removing the reactor head and fuel, the core barrel along with the upper and lower core in PWRs is lifted to open an annular space between the reactor shell flange and the core barrel flange. The thermal shield can remain

  10. Effect of Anodizing Time and Annealing Temperature on Photoelectrochemical Properties of Anodized TiO2 Nanotube for Corrosion Prevention Application

    Directory of Open Access Journals (Sweden)

    Misriyani Misriyani

    2017-07-01

    Full Text Available A study on the influence of anodizing time, annealing temperature and photoelectrochemical properties of TiO2 nanotube (TiO2 NT has been investigated. The crystallinity was investigated using X-Ray Diffraction and the anti-corrosion performance of stainless steel 304 (SS 304 coupled with TiO2 NT was evaluated using electrochemical techniques under ultraviolet exposure. The optimum anodizing condition occurs at a voltage of 20 V for 3 h. After anodizing, the TiO2 NT amorf was calcined at 500 °C to obtain anatase crystalline phase. For the photoelectrochemical property, the effects of pH and NaCl concentration on corrosion prevention have been examined. The result showed that the corrosion rate of stainless steel 304 coupled with TiO2 NT can be reduced up to 1.7 times compared to the uncoupled stainless steel 304 (3.05×10-6 to 1.78×10-6 mpy under ultraviolet exposure by shifted the photopotential to the more negative value (-0.302 V to -0.354 V at a pH of 8 and 3% NaCl concentration (-0.264 V to -0.291 V. In conclusion, the TiO2 NT films, which was prepared by anodization and followed by annealing can prevent the corrosion of stainless steel 304.

  11. First application of quantum annealing to IMRT beamlet intensity optimization

    International Nuclear Information System (INIS)

    Nazareth, Daryl P; Spaans, Jason D

    2015-01-01

    Optimization methods are critical to radiation therapy. A new technology, quantum annealing (QA), employs novel hardware and software techniques to address various discrete optimization problems in many fields. We report on the first application of quantum annealing to the process of beamlet intensity optimization for IMRT.We apply recently-developed hardware which natively exploits quantum mechanical effects for improved optimization. The new algorithm, called QA, is most similar to simulated annealing, but relies on natural processes to directly minimize a system’s free energy. A simple quantum system is slowly evolved into a classical system representing the objective function. If the evolution is sufficiently slow, there are probabilistic guarantees that a global minimum will be located.To apply QA to IMRT-type optimization, two prostate cases were considered. A reduced number of beamlets were employed, due to the current QA hardware limitations. The beamlet dose matrices were computed using CERR and an objective function was defined based on typical clinical constraints, including dose-volume objectives, which result in a complex non-convex search space. The objective function was discretized and the QA method was compared to two standard optimization methods, simulated annealing and Tabu search, run on a conventional computing cluster.Based on several runs, the average final objective function value achieved by the QA was 16.9 for the first patient, compared with 10.0 for Tabu and 6.7 for the simulated annealing (SA) method. For the second patient, the values were 70.7 for the QA, 120.0 for Tabu and 22.9 for the SA. The QA algorithm required 27–38% of the time required by the other two methods.In this first application of hardware-enabled QA to IMRT optimization, its performance is comparable to Tabu search, but less effective than the SA in terms of final objective function values. However, its speed was 3–4 times faster than the other two methods

  12. Effect of annealing on the compositional modulation of InAlAsSb

    Energy Technology Data Exchange (ETDEWEB)

    Baladés, N., E-mail: nuria.balades@uca.es [INNANOMAT group, Departamento de Ciencia de los Materiales e I. M. y Q. I., Instituto Universitario de Investigación en Microscopía Electrónica y Materiales (IMEYMAT), CEIMAR, Universidad de Cádiz, 11510 Puerto Real, Cádiz (Spain); Sales, D.L.; Herrera, M.; Delgado, F.J. [INNANOMAT group, Departamento de Ciencia de los Materiales e I. M. y Q. I., Instituto Universitario de Investigación en Microscopía Electrónica y Materiales (IMEYMAT), CEIMAR, Universidad de Cádiz, 11510 Puerto Real, Cádiz (Spain); González, M. [U.S Naval Research Laboratory, 4555 Overlook Ave. SW, Washington D.C. 20375 (United States); Sotera Defense Solutions, 430 National Business Pkwy # 100, Annapolis Junction, MD 20701 (United States); Clark, K.; Pinsunkajana, P. [Intelligent Epitaxy Technology, Inc. Richardson, TX, 75801 (United States); Hoven, N.; Hubbard, S. [Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623 (United States); Tomasulo, S.; Walters, J.R. [U.S Naval Research Laboratory, 4555 Overlook Ave. SW, Washington D.C. 20375 (United States); Molina, S.I. [INNANOMAT group, Departamento de Ciencia de los Materiales e I. M. y Q. I., Instituto Universitario de Investigación en Microscopía Electrónica y Materiales (IMEYMAT), CEIMAR, Universidad de Cádiz, 11510 Puerto Real, Cádiz (Spain)

    2017-02-15

    Highlights: • A post-growth annealing under As overpressure over 500 °C for several minutes induces a blue-shift in the InAlAsSb emission. • TEM analysis evidences that the small compositional fluctuations of the as-grown samples disappear after being annealed. • Annealing stimulates atomic diffusion of the quaternary, homogenizing their constituents and enhancing structural quality. - Abstract: The effect of a post-growth thermal treatment in two different heterostructures with InAlAsSb as the top layer grown by molecular beam epitaxy lattice-matched to InP, have been studied by diffraction contrast transmission electron microscopy (TEM). This novel top cell layer material with application in ultra-high efficiency solar cells were grown on (001) InP substrate with or without an InGaAs buffer layer. Initial photoluminescence (PL) measurements revealed deviations from their predicted bandgap, suggesting non-random atomic distribution of the quaternary layer. Then, a thermal annealing was performed at different temperatures and times. The effect on the structure of the InAlAsSb active layer caused by the new arrangement of layers and the post-growth annealing treatments has been reported. Our results show that the small compositional fluctuations of the as-grown heterostructures disappear after being annealed, and the bandgap energy correspondingly increases towards the predicted value.

  13. Origin of reverse annealing effect in hydrogen-implanted silicon

    Energy Technology Data Exchange (ETDEWEB)

    Di, Zengfeng [Los Alamos National Laboratory; Nastasi, Michael A [Los Alamos National Laboratory; Wang, Yongqiang [Los Alamos National Laboratory

    2009-01-01

    In contradiction to conventional damage annealing, thermally annealed H-implanted Si exhibits an increase in damage or reverse annealing behavior, whose mechanism has remained elusive. On the basis of quantitative high resolution transmission electron microscopy combined with channeling Rutherford backscattering analysis, we conclusively elucidate that the reverse annealing effect is due to the nucleation and growth of hydrogen-induce platelets. Platelets are responsible for an increase in the height and width the channeling damage peak following increased isochronal anneals.

  14. Annealing-induced evolution of optical properties of the multilayered nanoperiodic SiOx/ZrO2 system containing Si nanoclusters

    International Nuclear Information System (INIS)

    Ershov, A. V.; Tetelbaum, D. I.; Chugrov, I. A.; Mashin, A. I.; Mikhaylov, A. N.; Nezhdanov, A. V.; Ershov, A. A.; Karabanova, I. A.

    2011-01-01

    The photoluminescence, infrared absorption, and Raman spectra of amorphous multilayered nanoperiodic a-SiO x /ZrO 2 structures produced by vacuum evaporation and then annealed at different temperatures (500–1100°C) are studied. It is established that the evolution of the optical properties with increasing annealing temperature is controlled by sequential transformation of Si clusters formed in the SiO x layers from nonphase inclusions to amorphous clusters and then to nanocrystals. The finally formed nanocrystals are limited in sizes by the thickness of the initial SiO x layers and by chemical reactions with ZrO 2 .

  15. Estimating Reaction Rate Coefficients Within a Travel-Time Modeling Framework

    Energy Technology Data Exchange (ETDEWEB)

    Gong, R [Georgia Institute of Technology; Lu, C [Georgia Institute of Technology; Luo, Jian [Georgia Institute of Technology; Wu, Wei-min [Stanford University; Cheng, H. [Stanford University; Criddle, Craig [Stanford University; Kitanidis, Peter K. [Stanford University; Gu, Baohua [ORNL; Watson, David B [ORNL; Jardine, Philip M [ORNL; Brooks, Scott C [ORNL

    2011-03-01

    A generalized, efficient, and practical approach based on the travel-time modeling framework is developed to estimate in situ reaction rate coefficients for groundwater remediation in heterogeneous aquifers. The required information for this approach can be obtained by conducting tracer tests with injection of a mixture of conservative and reactive tracers and measurements of both breakthrough curves (BTCs). The conservative BTC is used to infer the travel-time distribution from the injection point to the observation point. For advection-dominant reactive transport with well-mixed reactive species and a constant travel-time distribution, the reactive BTC is obtained by integrating the solutions to advective-reactive transport over the entire travel-time distribution, and then is used in optimization to determine the in situ reaction rate coefficients. By directly working on the conservative and reactive BTCs, this approach avoids costly aquifer characterization and improves the estimation for transport in heterogeneous aquifers which may not be sufficiently described by traditional mechanistic transport models with constant transport parameters. Simplified schemes are proposed for reactive transport with zero-, first-, nth-order, and Michaelis-Menten reactions. The proposed approach is validated by a reactive transport case in a two-dimensional synthetic heterogeneous aquifer and a field-scale bioremediation experiment conducted at Oak Ridge, Tennessee. The field application indicates that ethanol degradation for U(VI)-bioremediation is better approximated by zero-order reaction kinetics than first-order reaction kinetics.

  16. Organic products from Ca14Co3 autoradiolysis: effects of thermal annealing

    International Nuclear Information System (INIS)

    Albarran S, M.G.; Collins, K.E.; Collins, C.H.

    1986-01-01

    Autoradiolysis of Ca 14 Co 3 produces several different low molecular mass organic compounds which can be conveniently observed after ion exclusion-partition chromatographic separation of the dissolved sample, provided that the solid was prepared with high specific activity carbon-14 and has been stored for a sufficiently long period. Subsequent thermal annealing changes the distribution of these observed compounds, demonstrating that chemical reactions of the precursor species take place in the solid Ca 14 Co 3 matrix. Specifically, the following products were observed after an autoradiolytic dose of 5 MGy: methanol, formaldehyde, formic acid, oxalic acid, glyoxylic acid, glycolic acid and acetic acid, with-G-values ranging from 5x10 -6 to 2x10 -3 . Isochronal annealing to 500 0 C markedly changes the yields of carbon-14 labelled formic and acetic acids but has lesser effects on the other acidic products. This indicates that several different precursor species are present in the autoradiolyzed solid. (Author) [pt

  17. Electrical behavior of amide functionalized graphene oxide and graphene oxide films annealed at different temperatures

    International Nuclear Information System (INIS)

    Rani, Sumita; Kumar, Mukesh; Kumar, Dinesh; Sharma, Sumit

    2015-01-01

    Films of graphene oxide (GO) and amide functionalized graphene oxides (AGOs) were deposited on SiO 2 /Si(100) by spin coating and were thermally annealed at different temperatures. Sheet resistance of GO and AGOs films was measured using four probe resistivity method. GO an insulator at room temperature, exhibits decrease in sheet resistance with increase in annealing temperature. However, AGOs' low sheet resistance (250.43 Ω) at room temperature further decreases to 39.26 Ω after annealing at 800 °C. It was observed that the sheet resistance of GO was more than AGOs up to 700 °C, but effect was reversed after annealing at higher temperature. At higher annealing temperatures the oxygen functionality reduces in GO and sheet resistance decreases. Sheet resistance was found to be annealing time dependent. Longer duration of annealing at a particular temperature results in decrease of sheet resistance. - Highlights: • Amide functionalized graphene oxides (AGOs) were synthesized at room temperature (RT). • AGO films have low sheet resistance at RT as compared to graphene oxide (GO). • Fast decrease in the sheet resistance of GO with annealing as compared to AGOs • AGOs were found to be highly dispersible in polar solvents

  18. Standard Guide for In-Service Annealing of Light-Water Moderated Nuclear Reactor Vessels

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2003-01-01

    1.1 This guide covers the general procedures to be considered for conducting an in-service thermal anneal of a light-water moderated nuclear reactor vessel and demonstrating the effectiveness of the procedure. The purpose of this in-service annealing (heat treatment) is to improve the mechanical properties, especially fracture toughness, of the reactor vessel materials previously degraded by neutron embrittlement. The improvement in mechanical properties generally is assessed using Charpy V-notch impact test results, or alternatively, fracture toughness test results or inferred toughness property changes from tensile, hardness, indentation, or other miniature specimen testing (1). 1.2 This guide is designed to accommodate the variable response of reactor-vessel materials in post-irradiation annealing at various temperatures and different time periods. Certain inherent limiting factors must be considered in developing an annealing procedure. These factors include system-design limitations; physical constrain...

  19. Annealing dependence of magnetic properties in nanostructured Sm0.5Y0.5Co5

    International Nuclear Information System (INIS)

    Elizalde-Galindo, J.T.; Hidalgo, J.L.; Botez, C.E.; Matutes-Aquino, J.A.

    2008-01-01

    Nanocrystalline Sm 0.5 Y 0.5 Co 5 powders with high coercivity H C and enhanced remanence M r were prepared by mechanical milling and subsequent annealing. Annealing temperatures T ranging from 973 to 1173 K, and times t ranging from 1 to 5 min were used. X-ray diffraction (XRD) and DC-magnetization measurements were carried out to study the microstructure and magnetic properties of these samples. XRD patterns demonstrate that the average grain size of the nanocrystalline powders depends on the annealing temperature T and time t: ranges from 11 nm (for T=973 K and t=1 min) to 93 nm (for T=1173 K and t=5 min). Magnetic measurements performed at room temperature indicate high coercivity values (H C >955 kA/m), and enhanced remanence (M r /M max >0.5) for all samples. A strong annealing-induced grain size dependence of these magnetic properties was found

  20. Effect of thermal annealing on a novel polyamide–imide polymer membrane for aggressive acid gas separations

    KAUST Repository

    Vaughn, Justin T.; Koros, William J.; Johnson, J.R.; Karvan, Oguz

    2012-01-01

    A fluorinated, 6FDA based polyamide-imide is investigated for the purification of CH 4 from CO 2 and H 2S containing gas streams. Dense polymer films were thermally annealed and showed that increased annealing temperatures at constant annealing time caused transport behavior that does not resemble physical aging. Free volume increased after annealing at 200°C for 24h relative to annealing at 150°C for the same time. CO 2 and CH 4 permeabilities and diffusivities did not decrease as a result of the higher annealing temperature, and in fact, were shown to increase slightly. A change to the intrinsic microstructure that cannot be described by simple, densification based physical aging is hypothesized to be the reason for this trend. Furthermore, annealing increased CO 2 induced plasticization resistance and a temperature of 200°C was shown to have the greatest effect on plasticization suppression. Annealing at 200°C for 24h suppressed pure gas CO 2 plasticization up to 450psia. Fluorescence spectroscopy revealed increased intramolecular charge transfer, which is presumably due to increased electron conjugation over the N-phenyl bond. Additionally, intermolecular charge transfer increased with thermal annealing, as inferred from fluorescence intensity measurements and XRD patterns. 50/50 CO 2/CH 4 mixed gas permeation measurements reveal stable separation performance up to 1000psia. Ternary mixed gas feeds containing toluene/CO 2/CH 4 and H 2S/CO 2/CH 4 show antiplasticization, but more importantly, selectivity losses due to plasticization did not occur up to 900psia of total feed pressure. These results show that the polyamide-imide family represents a promising class of separation materials for aggressive acid gas purifications. © 2012 Elsevier B.V.

  1. Effect of thermal annealing on a novel polyamide–imide polymer membrane for aggressive acid gas separations

    KAUST Repository

    Vaughn, Justin T.

    2012-05-01

    A fluorinated, 6FDA based polyamide-imide is investigated for the purification of CH 4 from CO 2 and H 2S containing gas streams. Dense polymer films were thermally annealed and showed that increased annealing temperatures at constant annealing time caused transport behavior that does not resemble physical aging. Free volume increased after annealing at 200°C for 24h relative to annealing at 150°C for the same time. CO 2 and CH 4 permeabilities and diffusivities did not decrease as a result of the higher annealing temperature, and in fact, were shown to increase slightly. A change to the intrinsic microstructure that cannot be described by simple, densification based physical aging is hypothesized to be the reason for this trend. Furthermore, annealing increased CO 2 induced plasticization resistance and a temperature of 200°C was shown to have the greatest effect on plasticization suppression. Annealing at 200°C for 24h suppressed pure gas CO 2 plasticization up to 450psia. Fluorescence spectroscopy revealed increased intramolecular charge transfer, which is presumably due to increased electron conjugation over the N-phenyl bond. Additionally, intermolecular charge transfer increased with thermal annealing, as inferred from fluorescence intensity measurements and XRD patterns. 50/50 CO 2/CH 4 mixed gas permeation measurements reveal stable separation performance up to 1000psia. Ternary mixed gas feeds containing toluene/CO 2/CH 4 and H 2S/CO 2/CH 4 show antiplasticization, but more importantly, selectivity losses due to plasticization did not occur up to 900psia of total feed pressure. These results show that the polyamide-imide family represents a promising class of separation materials for aggressive acid gas purifications. © 2012 Elsevier B.V.

  2. A Comparative Study of Simple Auditory Reaction Time in Blind (Congenitally) and Sighted Subjects

    OpenAIRE

    Gandhi, Pritesh Hariprasad; Gokhale, Pradnya A.; Mehta, H. B.; Shah, C. J.

    2013-01-01

    Background: Reaction time is the time interval between the application of a stimulus and the appearance of appropriate voluntary response by a subject. It involves stimulus processing, decision making, and response programming. Reaction time study has been popular due to their implication in sports physiology. Reaction time has been widely studied as its practical implications may be of great consequence e.g., a slower than normal reaction time while driving can have grave results. Objective:...

  3. Annealing experiments on and high-temperature behavior of the superconductor yttrium barium copper oxide (YBa2Cu3Ox)

    NARCIS (Netherlands)

    Brabers, V.A.M.; Jonge, de W.J.M.; Bosch, L.A.; Steen, van der C.; de Groote, A.M.W.; Verheyen, A.A.; Vennix, C.W.H.M.

    1988-01-01

    The high temperature behaviour (300–1100 K) of the superconductor YBa2Cu3Ox has been studied by annealing experiments, thermal dilatation, thermogravimetry and measurements of the electrical resistance and thermoelectric power. For the fast oxidation process of this compound, reaction enthalpies

  4. Quantum annealing for combinatorial clustering

    Science.gov (United States)

    Kumar, Vaibhaw; Bass, Gideon; Tomlin, Casey; Dulny, Joseph

    2018-02-01

    Clustering is a powerful machine learning technique that groups "similar" data points based on their characteristics. Many clustering algorithms work by approximating the minimization of an objective function, namely the sum of within-the-cluster distances between points. The straightforward approach involves examining all the possible assignments of points to each of the clusters. This approach guarantees the solution will be a global minimum; however, the number of possible assignments scales quickly with the number of data points and becomes computationally intractable even for very small datasets. In order to circumvent this issue, cost function minima are found using popular local search-based heuristic approaches such as k-means and hierarchical clustering. Due to their greedy nature, such techniques do not guarantee that a global minimum will be found and can lead to sub-optimal clustering assignments. Other classes of global search-based techniques, such as simulated annealing, tabu search, and genetic algorithms, may offer better quality results but can be too time-consuming to implement. In this work, we describe how quantum annealing can be used to carry out clustering. We map the clustering objective to a quadratic binary optimization problem and discuss two clustering algorithms which are then implemented on commercially available quantum annealing hardware, as well as on a purely classical solver "qbsolv." The first algorithm assigns N data points to K clusters, and the second one can be used to perform binary clustering in a hierarchical manner. We present our results in the form of benchmarks against well-known k-means clustering and discuss the advantages and disadvantages of the proposed techniques.

  5. Annealing of KDP crystals in vacuum and under pressure

    International Nuclear Information System (INIS)

    Pritula, I.M.; Kolybayeva, M.I.; Salo, V.I.

    1997-01-01

    The effect of the high temperature annealing (T an > 230 degrees C) on the absorption spectra and laser damage threshold of KDP crystals was studied in the present paper. The experiments on isotermal annealing were performed under pressure in the atmosphere with specific properties. The composition of the atmosphere was selected to be chose to that of the desorbing gas component determined during annealing in vacuum. The mentioned conditions allowed to conduct annealing in the temperature range of 230 - 280 degrees C without degradation of the sample. The variations in the absorption spectra showed that the effect of the annealing is most strongly revealed in the short - wave region of the spectrum (λ -1 before and k=0.12 cm -1 after annealing) demonstrate that at temperatures ∼ 230 - 280 degrees C the processes ensuring the improvement of the structure quality are stimulated in the volume of the crystals: (a) before the annealing laser damage threshold was 1.5 10 11 W/cm 2 ; (b) after the annealing (t = 280 degrees C) it became 4 10 11 W/cm 2

  6. A comparative study of simple auditory reaction time in blind (congenitally) and sighted subjects.

    Science.gov (United States)

    Gandhi, Pritesh Hariprasad; Gokhale, Pradnya A; Mehta, H B; Shah, C J

    2013-07-01

    Reaction time is the time interval between the application of a stimulus and the appearance of appropriate voluntary response by a subject. It involves stimulus processing, decision making, and response programming. Reaction time study has been popular due to their implication in sports physiology. Reaction time has been widely studied as its practical implications may be of great consequence e.g., a slower than normal reaction time while driving can have grave results. To study simple auditory reaction time in congenitally blind subjects and in age sex matched sighted subjects. To compare the simple auditory reaction time between congenitally blind subjects and healthy control subjects. STUDY HAD BEEN CARRIED OUT IN TWO GROUPS: The 1(st) of 50 congenitally blind subjects and 2(nd) group comprises of 50 healthy controls. It was carried out on Multiple Choice Reaction Time Apparatus, Inco Ambala Ltd. (Accuracy±0.001 s) in a sitting position at Government Medical College and Hospital, Bhavnagar and at a Blind School, PNR campus, Bhavnagar, Gujarat, India. Simple auditory reaction time response with four different type of sound (horn, bell, ring, and whistle) was recorded in both groups. According to our study, there is no significant different in reaction time between congenital blind and normal healthy persons. Blind individuals commonly utilize tactual and auditory cues for information and orientation and they reliance on touch and audition, together with more practice in using these modalities to guide behavior, is often reflected in better performance of blind relative to sighted participants in tactile or auditory discrimination tasks, but there is not any difference in reaction time between congenitally blind and sighted people.

  7. A study on residual stress mitigation of the HDPE pipe for various annealing conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Sung [Sunchon National University, Sunchon (Korea, Republic of); Yoo, Jeong Ho [Korea Laboratory Engineering System, Daejeon (Korea, Republic of); Oh, Young Jin [KEPCO E and C, Sungnam (Korea, Republic of)

    2015-03-15

    This paper presents effects of the annealing condition variables such as temperature and time on the residual stress mitigation. The effects were investigated by using the various measurement methods such as hole-drilling method and slitting method. As a result of the investigation, the residual stress mitigation magnitude increases with increasing the annealing time and temperature. Based on the investigation results, the quantitative correlations between the annealing variables and the residual stress mitigation were derived. Finally, the effect of long-term operation under the normal operating temperature conditions on the residual stress mitigation was investigated by referring to the derived equations and performing some additional tests, and it is identified that the residual stresses are not significantly relaxed over the design lifetime of the safety class III buried HDPE pipes.

  8. Ion-beam mixing and solid-state reaction in Zr-Fe multilayers

    International Nuclear Information System (INIS)

    Paesano, A. Jr.; Motta, A.T.; Birtcher, R.C.; Ryan, E.A.; Teixeira, S.R.; Bruckmann, M.E.; Amaral, L.

    1997-01-01

    Vapor-deposited Zr-Fe multilayered thin films with various wavelengths and of overall composition either 50% Fe or Fe-rich up to 57% Fe were either irradiated with 300 keV Kr ions at temperatures from 25 K to 623 K to fluences up to 2 x 10 16 cm -2 , or simply annealed at 773 K in-situ in the Intermediate Voltage Electron microscope At Argonne National Laboratory. Under irradiation, the final reaction product is the amorphous phase in all cases studied, but the dose to amorphization depends on the temperature and on the wavelength. In the purely thermal case (annealing at 773 K), the 50-50 composition produces the amorphous phase but for the Fe-rich multilayers the reaction products depend on the multilayer wavelength. For small wavelength, the amorphous phase is still formed, but at large wavelength the Zr-Fe crystalline intermetallic compounds appear. These results are discussed in terms of existing models of irradiation kinetics and phase selection during solid state reaction

  9. AFM and FTIR characterization of microcrystalline Si obtained from isothermal annealing of Al/a-Si:H

    Energy Technology Data Exchange (ETDEWEB)

    Rojas-Lopez, M.; Orduna-Diaz, A.; Delgado-Macuil, R. [Centro de Investigacion en Biotecnologia Aplicada (CIBA), IPN, Tlaxcala, Tlax. 72197 (Mexico); Olvera-Hernandez, J. [Centro de Investigacion en Dispositivos Semiconductores (CIDS), BUAP, Puebla, Pue. 72570 (Mexico); Navarro-Contreras, H.; Vidal, M.A.; Saucedo, N.; Mendez-Garcia, V.H. [Instituto de Investigacion en Comunicacion Optica (IICO), UASLP, San Luis Potosi, S.L.P. 78100 (Mexico)

    2007-04-15

    Atomic force microscopy and Fourier transform infrared spectroscopy were used to investigate the morphology of the microcrystalline surface, and also the amorphous-crystalline structural transformation of a-Si:H films, isothermally annealed during several hours. Crystallization process was strongly influenced by the deposition of an Al layer on the surface of a-Si:H samples. Representative AFM images show the presence of grains, which increase in diameter with the annealing time. Relative crystallized fraction as a function of the annealing time can be described adequately by using the Avrami equation. The kinetic of this crystallization process suggest a two-dimensional growth of the Si nuclei. Fourier transform infrared measurements show the presence of an intense band near 512 cm{sup -1} associated to Si-Si bonding. We observed the relative diminishing of the intensity of the Si-H wagging mode at 694 cm{sup -1} with annealing time, suggesting effusion of hydrogen to the surface of microcrystalline films. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Development of microstructure and mechanical properties during annealing of a cold-swaged Co-Cr-Mo alloy rod.

    Science.gov (United States)

    Mori, Manami; Sato, Nanae; Yamanaka, Kenta; Yoshida, Kazuo; Kuramoto, Koji; Chiba, Akihiko

    2016-12-01

    In this study, we investigated the evolution of the microstructure and mechanical properties during annealing of a cold-swaged Ni-free Co-Cr-Mo alloy for biomedical applications. A Co-28Cr-6Mo-0.14N-0.05C (mass%) alloy rod was processed by cold swaging, with a reduction in area of 27.7%, and then annealed at 1173-1423K for various periods up to 6h. The duplex microstructure of the cold-swaged rod consisted of a face-centered cubic γ-matrix and hexagonal closed-packed ε-martensite developed during cold swaging. This structure transformed nearly completely to the γ-phase after annealing and many annealing twin boundaries were observed as a result of the heat treatment. A small amount of the ε-phase was identified in specimens annealed at 1173K. Growth of the γ-grains occurred with increasing annealing time at temperatures ≥1273K. Interestingly, the grain sizes remained almost unchanged at 1173K and a very fine grain size of approximately 8μm was obtained. The precipitation that occurred during annealing was attributed to the limited grain coarsening during heat treatment. Consequently, the specimens treated at this temperature showed the highest tensile strength and lowest ductility among the specimens prepared. An elongation-to-failure value larger than 30% is sufficient for the proposed applications. The other specimens treated at higher temperatures possessed similar tensile properties and did not show any significant variations with different annealing times. Optimization of the present rod manufacturing process, including cold swaging and interval annealing heat treatment, is discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Onset temperature for Si nanostructure growth on Si substrate during high vacuum electron beam annealing.

    Science.gov (United States)

    Fang, F; Markwitz, A

    2009-05-01

    Silicon nanostructures, called Si nanowhiskers, are successfully synthesized on Si(100) substrate by high vacuum electron beam annealing. The onset temperature and duration needed for the Si nanowhiskers to grow was investigated. It was found that the onset and growth morphology of Si nanowhiskers strongly depend on the annealing temperature and duration applied in the annealing cycle. The onset temperature for nanowhisker growth was determined as 680 degrees C using an annealing duration of 90 min and temperature ramps of +5 degrees C s(-1) for heating and -100 degrees C s(-1) for cooling. Decreasing the annealing time at peak temperature to 5 min required an increase in peak temperature to 800 degrees C to initiate the nanowhisker growth. At 900 degrees C the duration for annealing at peak temperature can be set to 0 s to grow silicon nanowhiskers. A correlation was found between the variation in annealing temperature and duration and the nanowhisker height and density. Annealing at 900 degrees C for 0 s, only 2-3 nanowhiskers (average height 2.4 nm) grow on a surface area of 5 x 5 microm, whereas more than 500 nanowhiskers with an important average height of 4.6 nm for field emission applications grow on the same surface area for a sample annealed at 970 degrees C for 0 s. Selected results are presented showing the possibility of controlling the density and height of Si nanowhisker growth for field emission applications by applying different annealing temperature and duration.

  12. Microstructure and Dielectric Properties of LPCVD/CVI-SiBCN Ceramics Annealed at Different Temperatures

    Directory of Open Access Journals (Sweden)

    Jianping Li

    2017-06-01

    Full Text Available SiBCN ceramics were introduced into porous Si3N4 ceramics via a low-pressure chemical vapor deposition and infiltration (LPCVD/CVI technique, and then the composite ceramics were heat-treated from 1400 °C to 1700 °C in a N2 atmosphere. The effects of annealing temperatures on microstructure, phase evolution, dielectric properties of SiBCN ceramics were investigated. The results revealed that α-Si3N4 and free carbon were separated below 1700 °C, and then SiC grains formed in the SiBCN ceramic matrix after annealing at 1700 °C through a phase-reaction between free carbon and α-Si3N4. The average dielectric loss of composites increased from 0 to 0.03 due to the formation of dispersive SiC grains and the increase of grain boundaries.

  13. Effect of annealing on the structural properties of electron beam deposited CIGS thin films

    Energy Technology Data Exchange (ETDEWEB)

    Venkatachalam, M. [Department of Electronics, Erode Arts College, Erode (India)], E-mail: prabhu7737@yahoo.com; Kannan, M.D.; Jayakumar, S.; Balasundaraprabhu, R. [Thin Film Center, PSG College of Technology, Coimbatore (India); Muthukumarasamy, N. [Department of Physics, Coimbatore Institute of Technology, Coimbatore (India)

    2008-08-30

    CIGS bulk compound of three different compositions CuIn{sub 0.85}Ga{sub 0.15}Se{sub 2}, CuIn{sub 0.80}Ga{sub 0.20}Se{sub 2} and CuIn{sub 0.75}Ga{sub 0.25}Se{sub 2} have been prepared by direct reaction of elemental copper, indium, gallium and selenium. CIGS thin films of the three compositions have been deposited onto glass and silicon substrates using the prepared bulk by electron beam deposition method. The structural properties of the deposited films have been studied using X-ray diffraction technique. The as-deposited CIGS films have been found to be amorphous in nature. To study the effect of annealing on the structural properties, the films have been annealed in vacuum of the order of 10{sup -5} Torr. The X-ray diffractograms of the annealed CIGS films exhibited peaks revealing that the annealed films are crystalline in nature with tetragonal chalcopyrite structure. The (112) peak corresponding to the chalcopyrite structure has been observed to be the dominating peak in all the annealed films. The position of the (112) peak and other peaks in the X-ray diffraction pattern has been observed to shift to higher values of 2{theta} with the increase of gallium concentration. The lattice parameter values 'a' and 'c' have been calculated and they are found to be dependent on the concentration of gallium in the films. The FWHM in the X-ray diffraction pattern is found to decrease with an increase in annealing temperature indicating that the crystalline nature of the CIGS improves with increase in annealing temperature. The films grown on silicon substrates have been found to be of better crystalline quality than those deposited on glass substrates. The micro structural parameters like grain size, dislocation density and strain have been evaluated. The chemical constituents present in the deposited CIGS films have been identified using energy dispersive X-ray analysis. The surface topographical study on the films has been performed by AFM. The

  14. Annealed star-branched polyelectrolytes in solution

    NARCIS (Netherlands)

    Klein Wolterink, J.; Male, van J.; Cohen Stuart, M.A.; Koopal, L.K.; Zhulina, E.B.; Borisov, O.V.

    2002-01-01

    Equilibrium conformations of annealed star-branched polyelectrolytes (polyacids) are calculated with a numerical self-consistent-field (SCF) model. From the calculations we obtain also the size and charge of annealed polyelectrolyte stars as a function of the number of arms, pH, and the ionic

  15. Radiation damage annealing mechanisms and possible low temperature annealing in silicon solar cells

    Science.gov (United States)

    Weinberg, I.; Swartz, C. K.

    1980-01-01

    Deep level transient spectroscopy and the Shockley-Read-Hall recombination theory are used to identify the defect responsible for reverse annealing in 2 ohm-cm n+/p silicon solar cells. This defect, with energy level at Ev + 0.30 eV, has been tentatively identified as a boron-oxygen-vacancy complex. It has been also determined by calculation that the removal of this defect could result in significant annealing at temperatures as low as 200 C for 2 ohm-cm and lower resistivity cells.

  16. Open-System Quantum Annealing in Mean-Field Models with Exponential Degeneracy*

    Directory of Open Access Journals (Sweden)

    Kostyantyn Kechedzhi

    2016-05-01

    Full Text Available Real-life quantum computers are inevitably affected by intrinsic noise resulting in dissipative nonunitary dynamics realized by these devices. We consider an open-system quantum annealing algorithm optimized for such a realistic analog quantum device which takes advantage of noise-induced thermalization and relies on incoherent quantum tunneling at finite temperature. We theoretically analyze the performance of this algorithm considering a p-spin model that allows for a mean-field quasiclassical solution and, at the same time, demonstrates the first-order phase transition and exponential degeneracy of states, typical characteristics of spin glasses. We demonstrate that finite-temperature effects introduced by the noise are particularly important for the dynamics in the presence of the exponential degeneracy of metastable states. We determine the optimal regime of the open-system quantum annealing algorithm for this model and find that it can outperform simulated annealing in a range of parameters. Large-scale multiqubit quantum tunneling is instrumental for the quantum speedup in this model, which is possible because of the unusual nonmonotonous temperature dependence of the quantum-tunneling action in this model, where the most efficient transition rate corresponds to zero temperature. This model calculation is the first analytically tractable example where open-system quantum annealing algorithm outperforms simulated annealing, which can, in principle, be realized using an analog quantum computer.

  17. Infrared studies of defects formed during postirradiation anneals of Czochralski silicon

    Science.gov (United States)

    Londos, C. A.; Sarlis, N. V.; Fytros, L. G.

    1998-10-01

    This article reports on defect studies of neutron-irradiated Czochralski-grown silicon (Cz-Si) material by means of infrared spectroscopy. In particular, the investigation was focused on the evolution of the 828 cm-1 well-known band of A-center, due to isochronal anneals from room temperature (RT) up to ≈700 °C. The strength of the VO band begins to increase above ≈200 gradually up to 300 °C (stage I); then, it begins to decrease up to ≈400 °C (stage II), where upon it stabilizes up to ≈550 °C (stage III). Upon re-irradiation under exactly the same conditions and repeating the annealing process, the increase of the VO signal in stage I disappears. The phenomenon is ascribed to the existence of defect aggregates labeled as Xi centers which are correlated with (impurity-defect) clusters that compete with Oi in capturing vacancies. The presence of Xi centers is related to the thermal annealings performed. Comparison of the evolution of VO (828 cm-1) and VO2 (887 cm-1) bands between irradiated and re-irradiated materials, during stage II, is made and the results are discussed in the framework of established reaction patterns. The stabilization of the amplitude of the 828 cm-1 line in stage III is examined. The prevailing aspect is that a portion of A-centers in neutron-irradiated Si acquires larger thermal stability by relaxing in the vicinity of larger defects.

  18. Liquid nitrogen enhancement of partially annealed fission tracks in glass; and reply

    International Nuclear Information System (INIS)

    Wagner, G.A.; Carpenter, B.S.; Pilione, L.J.; Gold, D.P.

    1977-01-01

    Pilione and Gold (Nature 262: 773 (1976)) stated that it was possible to reveal partially annealed fission tracks in glass by immersion in liquid N 2 , and that it was possible to increase the total number of etchable tracks by increasing the immersion time. The present authors attempted to duplicate the work of the former authors using the same glass. They found no significant change in the number of etchable tracks after immersion in liquid N 2 , and they concluded that the latter has no effect on annealed tracks in glass. Any observed enhancement of partially annealed tracks is probably a surface effect and has no effect on the interior matrix of the glass. A reply by Pilione and Gold is appended. (U.K.)

  19. Time behaviour of the reaction front in the catalytic A + B → B + C reaction-diffusion processes

    International Nuclear Information System (INIS)

    Nicolini, F.G.; Rodriguez, M.A.; Wio, H.S.

    1994-07-01

    The problem of the time evolution of the position and width of a reaction front between initially separated reactants for the catalytic reaction A + B → B + C (C inert) is treated within a recently introduced Galanin-like scheme. (author). 6 refs

  20. High-temperature stability of chemically vapor-deposited tungsten-silicon couples rapid thermal annealed in ammonia and argon

    Energy Technology Data Exchange (ETDEWEB)

    Broadbent, E.K.; Morgan, A.E.; Flanner, J.M.; Coulman, B.; Sadana, D.K.; Burrow, B.J.; Ellwanger, R.C.

    1988-12-15

    A rapid thermal anneal (RTA) in an NH/sub 3/ ambient has been found to increase the thermal stability of W films chemically vapor deposited (CVD) on Si. W films deposited onto single-crystal Si by low-pressure CVD were rapid thermal annealed at temperatures between 500 and 1100 /sup 0/C in NH/sub 3/ and Ar ambients. The reactions were studied using Rutherford backscattering spectrometry, x-ray diffraction, Auger electron spectroscopy, transmission electron microscopy, and four-point resistivity probe. High-temperature (greater than or equal to1000 /sup 0/C) RTA in Ar completely converted W into the low resistivity (31 ..mu cap omega.. cm) tetragonal WSi/sub 2/ phase. In contrast, after a prior 900 /sup 0/C RTA in NH/sub 3/, N inclusion within the W film and at the W/Si interface almost completely suppressed the W-Si reaction. Detailed examination, however, revealed some patches of WSi/sub 2/ formed at the interface accompanied by long tunnels extending into the substrate, and some crystalline precipitates in the substrate close to the interface. The associated interfacial contact resistance was only slightly altered by the 900 /sup 0/C NH/sub 3/ anneal. The NH/sub 3/-treated W film acted as a diffusion barrier in an Al/W/Si contact metallurgy up to at least 550 /sup 0/C, at which point some increase in contact resistance was measured.

  1. Microwave Synthesized ZnO Nanorod Arrays for UV Sensors: A Seed Layer Annealing Temperature Study.

    Science.gov (United States)

    Pimentel, Ana; Ferreira, Sofia Henriques; Nunes, Daniela; Calmeiro, Tomas; Martins, Rodrigo; Fortunato, Elvira

    2016-04-20

    The present work reports the influence of zinc oxide (ZnO) seed layer annealing temperature on structural, optical and electrical properties of ZnO nanorod arrays, synthesized by hydrothermal method assisted by microwave radiation, to be used as UV sensors. The ZnO seed layer was produced using the spin-coating method and several annealing temperatures, ranging from 100 to 500 °C, have been tested. X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and spectrophotometry measurements have been used to investigate the structure, morphology, and optical properties variations of the produced ZnO nanorod arrays regarding the seed layer annealing temperatures employed. After the growth of ZnO nanorod arrays, the whole structure was tested as UV sensors, showing an increase in the sensitivity with the increase of seed layer annealing temperature. The UV sensor response of ZnO nanorod arrays produced with the seed layer annealed temperature of 500 °C was 50 times superior to the ones produced with a seed layer annealed at 100 °C.

  2. Impact of soft annealing on the performance of solution-processed amorphous zinc tin oxide thin-film transistors

    KAUST Repository

    Nayak, Pradipta K.; Hedhili, Mohamed N.; Cha, Dong Kyu; Alshareef, Husam N.

    2013-01-01

    It is demonstrated that soft annealing duration strongly affects the performance of solution-processed amorphous zinc tin oxide thin-film transistors. Prolonged soft annealing times are found to induce two important changes in the device: (i) a

  3. Structural and electrical characterization of AuPtAlTi ohmic contacts to AlGaN/GaN with varying annealing temperature and Al content

    OpenAIRE

    Fay, Mike W.; Han, Y.; Brown, Paul D.; Harrison, Ian; Hilton, K.P.; Munday, A.; Wallis, D.; Balmer, R.S.; Uren, M.J.; Martin, T.

    2008-01-01

    The effect of varying annealing temperature and Al layer thickness on the structural and electrical characteristics of AuPtAlTi/AlGaN/GaN ohmic contact structures has been systematically investigated. The relationship between annealing temperature, Al content, interfacial microstructure, surface planarity and contact resistance is\\ud examined. In particular, the presence of a detrimental low temperature Pt-Al reaction is identified. This is implicated in both the requirement for a higher Al:T...

  4. The role of Frenkel defect diffusion in dynamic annealing in ion-irradiated Si

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, J. B.; Aji, L. B. Bayu; Martin, A. A.; Shin, S. J.; Shao, L.; Kucheyev, S. O.

    2017-01-06

    The formation of stable radiation damage in crystalline solids often proceeds via complex dynamic annealing processes, involving migration and interaction of ballistically-generated point defects. The dominant dynamic annealing processes, however, remain unknown even for crystalline Si. Here, we use a pulsed ion beam method to study defect dynamics in Si bombarded in the temperature range from -20 to 140 °C with 500 keV Ar ions. Results reveal a defect relaxation time constant of ~10–0.2 ms, which decreases monotonically with increasing temperature. The dynamic annealing rate shows an Arrhenius dependence with two well-defined activation energies of 73 ± 5 meV and 420 ± 10 meV, below and above 60 °C, respectively. Rate theory modeling, bench-marked against this data, suggests a crucial role of both vacancy and interstitial diffusion, with the dynamic annealing rate limited by the migration and interaction of vacancies.

  5. Chemical effects of (n,2n) reactions on iodate and periodates systems

    International Nuclear Information System (INIS)

    Mendonca, J.M.A. de.

    1975-12-01

    The chemical consequences of (n,2n) reactions on cristalline sodium iodate and periodates were investigated measuring the initial yield and the post irradiation thermal annealing yields (90 0 C) of the separated fractions I - , IO 3 - and IO 4 - . NaIO 3 , NaIO 3 .H 2 O and NaIO 4 , Na 4 H 2 IO 6 , Na 4 I 2 O 9 .3H 2 O containing 127 I and 129 I, or both, were irradiated with 14 MeV neutrons. Results obtained show different effects for each system and that 126 I and 128 I isotopes keep the same behaviour in the irradiated compounds containing only α 127 I or 129 I and in compounds having both 127 I and 129 I. Neither isotope effect nor qualitative differences on thermal annealing at 90 0 C were observed. The annealed fractions in the three studied periodates were IO - 3 and IO - 4 . These results differ from the ones reported previously for (n,γ) reactions on the same compounds [pt

  6. QRTEngine: An easy solution for running online reaction time experiments using Qualtrics.

    Science.gov (United States)

    Barnhoorn, Jonathan S; Haasnoot, Erwin; Bocanegra, Bruno R; van Steenbergen, Henk

    2015-12-01

    Performing online behavioral research is gaining increased popularity among researchers in psychological and cognitive science. However, the currently available methods for conducting online reaction time experiments are often complicated and typically require advanced technical skills. In this article, we introduce the Qualtrics Reaction Time Engine (QRTEngine), an open-source JavaScript engine that can be embedded in the online survey development environment Qualtrics. The QRTEngine can be used to easily develop browser-based online reaction time experiments with accurate timing within current browser capabilities, and it requires only minimal programming skills. After introducing the QRTEngine, we briefly discuss how to create and distribute a Stroop task. Next, we describe a study in which we investigated the timing accuracy of the engine under different processor loads using external chronometry. Finally, we show that the QRTEngine can be used to reproduce classic behavioral effects in three reaction time paradigms: a Stroop task, an attentional blink task, and a masked-priming task. These findings demonstrate that QRTEngine can be used as a tool for conducting online behavioral research even when this requires accurate stimulus presentation times.

  7. Development of a supplemental surveillance program for reactor pressure vessel thermal annealing

    International Nuclear Information System (INIS)

    Server, W.L.; Rosinski, S.T.

    1997-01-01

    The technical decision to thermally anneal a nuclear reactor pressure vessel (RPV) depends upon the level of embrittlement in the RPV steels, the amount of recovery of fracture toughness properties expected from the anneal, and the rate of re-embrittlement after the vessel is placed back into service. The recovery of Charpy impact toughness properties after annealing can be estimated initially by using a recovery model developed using experimental measurements of recovery (such as that developed by Eason et al. for U.S. vessel materials). However, actual validation measurements on plant-specific archived vessel materials (hopefully in the existing surveillance program) are needed; otherwise, irradiated surrogate materials, essentially the same as the RPV steels or bounding in expected behavior, must be utilized. The efficient use of any of these materials requires a supplemental surveillance program focused at both recovery and reirradiation embrittlement. Reconstituted Charpy specimens and new surveillance capsules will most likely be needed as part of this supplemental surveillance program. A new version of ASTM E 509 has recently been approved which provides guidance on thermal annealing in general and specifically for the development of an annealing supplemental surveillance program. The post-anneal re-embrittlement properties are crucial for continued plant operation, and the use of a re-embrittlement model, such as the lateral shift approach, may be overly conservative. This paper illustrates the new ASTM E 509 Standard Guide methodology for an annealing supplemental surveillance program. As an example, the proposed program for the Palisades RPV beltline steels is presented which covers the time from annealing to the end of operating license and beyond, if license renewal is pursued. The Palisades nuclear power plant RPV was planned to be annealed in 1998, but that plant is currently being re-evaluated. The proposed anneal was planned to be conducted at a

  8. Structure and properties of melt-spun high acrylonitrile copolymer fibers via continuous zone-drawing and zone-annealing processes

    International Nuclear Information System (INIS)

    Wu Zongquan; Zhang Anqiu; Percec, Simona; Jin Shi; Jing, Alexander J.; Ge, Jason J.; Cheng, Stephen Z.D.

    2003-01-01

    Continuous zone-drawing and zone-annealing processes have been utilized to probe improvements in mechanical performance of melt-spun high acrylonitrile copolymer fibers (AMLON TM ). The as-spun fibers were zone-drawn at different ratios in a narrow temperature range of 100-105 deg. C and then zone-annealed. As a result of these processes, the fibers show substantial increases in tensile strength and tensile modulus (about three times) and significant improvements in elongation-at-break (about two times) after zone annealing. The thermal transition behavior, dimensional stability and dynamic relaxation properties of the as-spun, zone-drawn and zone-annealed fibers have been studied using differential scanning calorimetry, thermal mechanical and dynamic mechanical experiments. Their mechanical and thermal property changes after the zone-drawing and zone-annealing processes can be associated with the microscopic structural evolution including crystallinity, crystal orientation and apparent crystallite size detected by wide angle X-ray diffraction experiments

  9. The time dependence of rate constants of esub(aq)sup(-) reactions

    International Nuclear Information System (INIS)

    Burcl, R.; Byakov, V.M.; Grafutin, V.I.

    1982-01-01

    Published data about the time dependence of rate constants k(esub(aq)sup(-)+Ac) of esub(aq)sup(-) reactions with the acceptor Ac are analyzed, using the results of rate constant k(Ps+Ac) measurements for positronium reactions. It is shown that neither esub(aq)sup(-) nor Ps reaction rate constants depend on time in the observable range. Experimentally found concentration dependence of k(esub(aq)sup(-)+Ac) is due to other factors, connected with the existence of electric charge of esub(aq)sup(-), e.g. ionic strength, tunnelling effect etc. (author)

  10. Room-temperature annealing of Si implantation damage in InP

    International Nuclear Information System (INIS)

    Akano, U.G.; Mitchell, I.V.

    1991-01-01

    Spontaneous recovery at 295 K of Si implant damage in InP is reported. InP(Zn) and InP(S) wafers of (100) orientation have been implanted at room temperature with 600 keV Si + ions to doses ranging from 3.6x10 11 to 2x10 14 cm -2 . Room-temperature annealing of the resultant damage has been monitored by the Rutherford backscattering/channeling technique. For Si doses ≤4x10 13 cm -2 , up to 70% of the initial damage (displaced atoms) annealed out over a period of ∼85 days. The degree of recovery was found to depend on the initial level of damage. Recovery is characterized by at least two time constants t 1 2 ∼100 days. Anneal rates observed between 295 and 375 K are consistent with an activation energy of 1.2 eV, suggesting that the migration of implant-induced vacancies is associated with the reordering of the InP lattice

  11. Annealing studies of Zircaloy-2 cladding at 580-850 deg C

    International Nuclear Information System (INIS)

    Hindle, E.D.

    1983-01-01

    For fuel rod cladding it is important to determine if prior metallurgical condition combined with irradiation damage can influence high temperature deformation, because studies of such deformation are required to produce data for the cladding ballooning models which are used in analysing loss-of-coolant (LOCA). If the behaviour of all cladding conditions during a LOCA can be represented by, say, the annealed condition, then a great deal of experimental work on a multiplicity of cladding conditions can be avoided. By examining the metallographic structure and hardness, the present study determines the time required in the range 580 to 850 deg C for returning Zircaloy cladding to the annealed condition, so that for any transient a point can be specified where the material should have annealed. An equation has been derived to give this information. (author)

  12. Effects of solvent evaporation conditions on solvent vapor annealed cylinder-forming block polymer thin films

    Science.gov (United States)

    Grant, Meagan; Jakubowski, William; Nelson, Gunnar; Drapes, Chloe; Baruth, A.

    Solvent vapor annealing is a less time and energy intensive method compared to thermal annealing, to direct the self-assembly of block polymer thin films. Periodic nanostructures have applications in ultrafiltration, magnetic arrays, or other structures with nanometer dimensions, driving its continued interest. Our goal is to create thin films with hexagonally packed, perpendicular aligned cylinders of poly(lactide) in a poly(styrene) matrix that span the thickness of the film with low anneal times and low defect densities, all with high reproducibility, where the latter is paramount. Through the use of our computer-controlled, pneumatically-actuated, purpose-built solvent vapor annealing chamber, we have the ability to monitor and control vapor pressure, solvent concentration within the film, and solvent evaporation rate with unprecedented precision and reliability. Focusing on evaporation, we report on two previously unexplored areas, chamber pressure during solvent evaporation and the flow rate of purging gas aiding the evaporation. We will report our exhaustive results following atomic force microscopy analysis of films exposed to a wide range of pressures and flow rates. Reliably achieving well-ordered films, while occurring within a large section of this parameter space, was correlated with high-flow evaporation rates and low chamber pressures. These results have significant implications on other methods of solvent annealing, including ``jar'' techniques.

  13. Study of grain structure evolution during annealing of a twin-roll-cast Mg alloy

    International Nuclear Information System (INIS)

    Tripathi, A.; Samajdar, I.; Nie, J.F.; Tewari, A.

    2016-01-01

    The evolution of microstructure under static annealing was studied for mid-thickness section of a twin-roll-cast (TRC) magnesium alloy. Annealing was performed at 300 °C and 500 °C for different times. Microstructural evolution was quantitatively analyzed, from optical micrographs, using grain path envelope analysis. Additional information from electron backscatter diffraction (EBSD) was used for addressing the possible mechanism(s). It was found that the TRC structure had a bimodal grain size, which was preserved even after annealing at 300 °C. However, the annealing at 500 °C led to a unimodal grain size. This difference in the grain size distribution created a contrasting behavior in the normalized standard deviations. This was primarily attributed to a competition between recovery and recrystallization, and their respective dominance at 300° and 500 °C. A deformation induced recrystallization recovery (DIRR) model was proposed. The proposed model could successfully address the experimental microstructural evolution. - Highlights: • Annealing of twin roll cast (TRC) magnesium alloy was done at temperatures of 300 °C and 500 °C. • TRC had bimodal structure. Bimodality preserved for annealing at 300 °C. Annealing at 500 °C led to unimodal structure. • Grain evolution was described based on the competition between recovery and recrystallization. • Deformation induced recrystallization recovery (DIRR) mechanistic model was developed.

  14. Low thermal budget annealing technique for high performance amorphous In-Ga-ZnO thin film transistors

    Directory of Open Access Journals (Sweden)

    Joong-Won Shin

    2017-07-01

    Full Text Available In this paper, we investigate a low thermal budget post-deposition-annealing (PDA process for amorphous In-Ga-ZnO (a-IGZO oxide semiconductor thin-film-transistors (TFTs. To evaluate the electrical characteristics and reliability of the TFTs after the PDA process, microwave annealing (MWA and rapid thermal annealing (RTA methods were applied, and the results were compared with those of the conventional annealing (CTA method. The a-IGZO TFTs fabricated with as-deposited films exhibited poor electrical characteristics; however, their characteristics were improved by the proposed PDA process. The CTA-treated TFTs had excellent electrical properties and stability, but the CTA method required high temperatures and long processing times. In contrast, the fabricated RTA-treated TFTs benefited from the lower thermal budget due to the short process time; however, they exhibited poor stability. The MWA method uses a low temperature (100 °C and short annealing time (2 min because microwaves transfer energy directly to the substrate, and this method effectively removed the defects in the a-IGZO TFTs. Consequently, they had a higher mobility, higher on-off current ratio, lower hysteresis voltage, lower subthreshold swing, and higher interface trap density than TFTs treated with CTA or RTA, and exhibited excellent stability. Based on these results, low thermal budget MWA is a promising technology for use on various substrates in next generation displays.

  15. Low thermal budget annealing technique for high performance amorphous In-Ga-ZnO thin film transistors

    Science.gov (United States)

    Shin, Joong-Won; Cho, Won-Ju

    2017-07-01

    In this paper, we investigate a low thermal budget post-deposition-annealing (PDA) process for amorphous In-Ga-ZnO (a-IGZO) oxide semiconductor thin-film-transistors (TFTs). To evaluate the electrical characteristics and reliability of the TFTs after the PDA process, microwave annealing (MWA) and rapid thermal annealing (RTA) methods were applied, and the results were compared with those of the conventional annealing (CTA) method. The a-IGZO TFTs fabricated with as-deposited films exhibited poor electrical characteristics; however, their characteristics were improved by the proposed PDA process. The CTA-treated TFTs had excellent electrical properties and stability, but the CTA method required high temperatures and long processing times. In contrast, the fabricated RTA-treated TFTs benefited from the lower thermal budget due to the short process time; however, they exhibited poor stability. The MWA method uses a low temperature (100 °C) and short annealing time (2 min) because microwaves transfer energy directly to the substrate, and this method effectively removed the defects in the a-IGZO TFTs. Consequently, they had a higher mobility, higher on-off current ratio, lower hysteresis voltage, lower subthreshold swing, and higher interface trap density than TFTs treated with CTA or RTA, and exhibited excellent stability. Based on these results, low thermal budget MWA is a promising technology for use on various substrates in next generation displays.

  16. Preparation of (Bi, Pb)-2223/Ag tapes by high temperature sintering and post-annealing process

    DEFF Research Database (Denmark)

    Hua, L.; Grivel, Jean-Claude; Andersen, L.G.

    2002-01-01

    A novel heat treatment process was developed to fabricate (Bi, Pb)-2223/Ag tapes with high critical current density (J(c)). The process can be divided into two parts: reformation and post-annealing. Tapes were first heated to the maximum temperature (830-860 degreesC) followed by slow cooling...... (reformation). Then, tape, were annealed between 760 and 820 degreesC (post-annealing). Reformation is expected to produce a large amount of liquid phase which may heat microcracks, decrease porosity, and improve grain growth. However, since the sintering temperature is beyond the Bi-2223 single-phase region......-energy synchrotron XRD and SEM/EDX. Some process parameters e.g. sintering temperature. cooling rate. and post-annealing time were optimised. (C) 2002 Elsevier Science B.V. All rights reserved....

  17. Controllably annealed CuO-nanoparticle modified ITO electrodes: Characterisation and electrochemical studies

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tong; Su, Wen; Fu, Yingyi [College of Chemistry, Beijing Normal University, Beijing 100875 (China); Hu, Jingbo, E-mail: hujingbo@bnu.edu.cn [College of Chemistry, Beijing Normal University, Beijing 100875 (China); Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, Beijing 100875 (China)

    2016-12-30

    Graphical abstract: We report a simple and controllable synthesis of CuO-nanoparticle-modified ITO by employing a combination of ion-implantation and annealing methods for the first time. The optimum CuO/ITO electrode shows uniform morphology, highly accessible surface area, long-term stability and excellent electrochemical performance towards biomolecules such as glucose in alkaline solution. - Highlights: • Controllably annealed CuO/ITO electrode was synthesized for the first time. • The generation mechanism of CuO nanoparticles is revealed. • The optimum CuO/ITO electrode shows excellent electrochemical performance. • A reference for the controllable preparation of other metal oxide nanoparticles. - Abstract: In this paper, we report a facile and controllable two-step approach to produce indium tin oxide electrodes modified by copper(II) oxide nanoparticles (CuO/ITO) through ion implantation and annealing methods. After annealing treatment, the surface morphology of the CuO/ITO substrate changed remarkably and exhibited highly electroactive sites and a high specific surface area. The effects of annealing treatment on the synthesis of CuO/ITO were discussed based on various instruments’ characterisations, and the possible mechanism by which CuO nanoparticles were generated was also proposed in this work. Cyclic voltammetric results indicated that CuO/ITO electrodes exhibited effective catalytic responses toward glucose in alkaline solution. Under optimal experimental conditions, the proposed CuO/ITO electrode showed sensitivity of 450.2 μA cm{sup −2} mM{sup −1} with a linear range of up to ∼4.4 mM and a detection limit of 0.7 μM (S/N = 3). Moreover, CuO/ITO exhibited good poison resistance, reproducibility, and stability properties.

  18. Time-reversal asymmetry: polarization and analyzing power in nuclear reactions

    International Nuclear Information System (INIS)

    Rioux, C.; Roy, R.; Slobodrian, R.J.; Conzett, H.E.

    1984-01-01

    Measurements of the proton polarization in the reactions 7 Li( 3 He, p vector) 9 Be and 9 Be( 3 He, p vector) 11 B and of the analyzing powers in the inverse reactions, initiated by polarized protons at the same center-of-mass energies, show significant differences. This implies the failure of the polarization-analyzing-power theorem and, prima facie, of time-reversal invariance in these reactions. The reaction 2 H( 3 He, p vector) 4 He and its inverse have also been investigated and show smaller differences. A discussion of instrumental asymmetries is presented

  19. Time asymmetry: Polarization and analyzing power in the nuclear reactions

    International Nuclear Information System (INIS)

    Rioux, C.; Roy, R.; Slobodrian, R.J.; Conzett, H.E.

    1983-01-01

    Measurements of the proton polarization in the reactions 7 Li( 3 He, p vector) 9 Be and 9 Be( 3 He, p vector) 11 B and of the analyzing powers of the inverse reactions, initiated by polarized protons at the same c.m. energies, show significant differences which imply the failure of the polarization-analyzing-power theorem and, prima facie, of time-reversal invariance in these reactions. The reaction 2 H( 3 He, p vector) 4 He and its inverse have also been investigated and show some smaller differences. A discussion of the instrumental asymmetries is presented. (orig.)

  20. Room temperature photoluminescence properties of ZnO nanorods grown by hydrothermal reaction

    Energy Technology Data Exchange (ETDEWEB)

    Iwan, S., E-mail: iwan-sugihartono@unj.ac.id [Jurusan Fisika, FMIPA-UNJ, Rawamangun, Jakarta (Indonesia); Prodi Ilmu Material, Departemen Fisika, FMIPA, Universitas Indonesia, Kampus UI Depok (Indonesia); Fauzia, Vivi [Prodi Ilmu Material, Departemen Fisika, FMIPA, Universitas Indonesia, Kampus UI Depok (Indonesia); Umar, A. A. [Institute of Microengineering and Nanoelectronics, Universiti Kebangsaan Malaysia, UKM Bangi, Selangor (Malaysia); Sun, X. W. [School of Electrical & Electronic Engineering, Nanyang Technological University, Nanyang Avenue (Singapore)

    2016-04-19

    Zinc oxide (ZnO) nanorods were fabricated by a hydrothermal reaction on silicon (Si) substrate at 95 °C for 6 hours. The ZnO seed layer was fabricated by depositing ZnO thin films on Si substrates by ultrasonic spray pyrolisis (USP). The annealing effects on crystal structure and optical properties of ZnO nanorods were investigated. The post-annealing treatment was performed at 800 °C with different environments. The annealed of ZnO nanorods were characterized by X-ray diffraction (XRD) and photoluminescence (PL) in order to analyze crystal structure and optical properties, respectively. The results show the orientations of [002], [101], [102], and [103] diffraction peaks were observed and hexagonal wurtzite structure of ZnO nanorods were vertically grown on Si substrates. The room temperature PL spectra show ultra-violet (UV) and visible emissions. The annealed of ZnO nanorods in vacuum condition (3.8 × 10{sup −3} Torr) has dominant UV emission. Meanwhile, non-annealed of ZnO nanorods has dominant visible emission. It was expected that the annealed of ZnO in vacuum condition suppresses the existence of native defects in ZnO nanorods.

  1. Loading pattern optimization by multi-objective simulated annealing with screening technique

    International Nuclear Information System (INIS)

    Tong, K. P.; Hyun, C. L.; Hyung, K. J.; Chang, H. K.

    2006-01-01

    This paper presents a new multi-objective function which is made up of the main objective term as well as penalty terms related to the constraints. All the terms are represented in the same functional form and the coefficient of each term is normalized so that each term has equal weighting in the subsequent simulated annealing optimization calculations. The screening technique introduced in the previous work is also adopted in order to save computer time in 3-D neutronics evaluation of trial loading patterns. For numerical test of the new multi-objective function in the loading pattern optimization, the optimum loading patterns for the initial and the cycle 7 reload PWR core of Yonggwang Unit 4 are calculated by the simulated annealing algorithm with screening technique. A total of 10 optimum loading patterns are obtained for the initial core through 10 independent simulated annealing optimization runs. For the cycle 7 reload core one optimum loading pattern has been obtained from a single simulated annealing optimization run. More SA optimization runs will be conducted to optimum loading patterns for the cycle 7 reload core and results will be presented in the further work. (authors)

  2. Single-molecule stochastic times in a reversible bimolecular reaction

    Science.gov (United States)

    Keller, Peter; Valleriani, Angelo

    2012-08-01

    In this work, we consider the reversible reaction between reactants of species A and B to form the product C. We consider this reaction as a prototype of many pseudobiomolecular reactions in biology, such as for instance molecular motors. We derive the exact probability density for the stochastic waiting time that a molecule of species A needs until the reaction with a molecule of species B takes place. We perform this computation taking fully into account the stochastic fluctuations in the number of molecules of species B. We show that at low numbers of participating molecules, the exact probability density differs from the exponential density derived by assuming the law of mass action. Finally, we discuss the condition of detailed balance in the exact stochastic and in the approximate treatment.

  3. Simulated Stochastic Approximation Annealing for Global Optimization With a Square-Root Cooling Schedule

    KAUST Repository

    Liang, Faming

    2014-04-03

    Simulated annealing has been widely used in the solution of optimization problems. As known by many researchers, the global optima cannot be guaranteed to be located by simulated annealing unless a logarithmic cooling schedule is used. However, the logarithmic cooling schedule is so slow that no one can afford to use this much CPU time. This article proposes a new stochastic optimization algorithm, the so-called simulated stochastic approximation annealing algorithm, which is a combination of simulated annealing and the stochastic approximation Monte Carlo algorithm. Under the framework of stochastic approximation, it is shown that the new algorithm can work with a cooling schedule in which the temperature can decrease much faster than in the logarithmic cooling schedule, for example, a square-root cooling schedule, while guaranteeing the global optima to be reached when the temperature tends to zero. The new algorithm has been tested on a few benchmark optimization problems, including feed-forward neural network training and protein-folding. The numerical results indicate that the new algorithm can significantly outperform simulated annealing and other competitors. Supplementary materials for this article are available online.

  4. Direct comparison of quantum and simulated annealing on a fully connected Ising ferromagnet

    Science.gov (United States)

    Wauters, Matteo M.; Fazio, Rosario; Nishimori, Hidetoshi; Santoro, Giuseppe E.

    2017-08-01

    We compare the performance of quantum annealing (QA, through Schrödinger dynamics) and simulated annealing (SA, through a classical master equation) on the p -spin infinite range ferromagnetic Ising model, by slowly driving the system across its equilibrium, quantum or classical, phase transition. When the phase transition is second order (p =2 , the familiar two-spin Ising interaction) SA shows a remarkable exponential speed-up over QA. For a first-order phase transition (p ≥3 , i.e., with multispin Ising interactions), in contrast, the classical annealing dynamics appears to remain stuck in the disordered phase, while we have clear evidence that QA shows a residual energy which decreases towards zero when the total annealing time τ increases, albeit in a rather slow (logarithmic) fashion. This is one of the rare examples where a limited quantum speedup, a speedup by QA over SA, has been shown to exist by direct solutions of the Schrödinger and master equations in combination with a nonequilibrium Landau-Zener analysis. We also analyze the imaginary-time QA dynamics of the model, finding a 1 /τ2 behavior for all finite values of p , as predicted by the adiabatic theorem of quantum mechanics. The Grover-search limit p (odd )=∞ is also discussed.

  5. Auditory and visual reaction time and peripheral field of vision in helmet users

    Directory of Open Access Journals (Sweden)

    Abbupillai Adhilakshmi

    2016-12-01

    Full Text Available Background: The incidence of fatal accidents are more in two wheeler drivers compared to four wheeler drivers. Head injury is of serious concern when recovery and prognosis of the patients are warranted, helmets are being used for safety purposes by moped, scooters and motorcycle drivers. Although, helmets are designed with cushioning effect to prevent head injuries but there are evidences of increase risk of neck injuries and reduced peripheral vision and hearing in helmet users. A complete full coverage helmets provide about less than 3 percent restrictions in horizontal peripheral visual field compared to rider without helmet. The standard company patented ergonomically designed helmets which does not affect the peripheral vision neither auditory reaction time. Objective: This pilot study aimed to evaluate the peripheral field of vision and auditory and visual reaction time in a hypertensive, diabetic and healthy male and female in order to have a better insight of protective characteristics of helmet in health and disease. Method: This pilot study carried out on age matched male of one healthy, one hypertensive and one diabetic and female subject of one healthy, one hypertensive and one diabetics. The field of vision was assessed by Lister’s perimeter whereas auditory and visual reaction time was recorded with response analyser. Result : Gender difference was not noted in peripheral field of vision but mild difference was found in auditory reaction time for high frequency and visual reaction time for both red and green colour in healthy control. But lateral and downward peripheral visual field was found reduced whereas auditory and visual reaction time was found increased in both hypertensive and diabetic subject in both sexes. Conclusion: Peripheral vision, auditory reaction time and visual reaction time in hypertensive and diabetics may lead to vulnerable accident. Helmet use has proven to reduce extent of injury in motorcyclist and

  6. Effect of milling time and annealing temperature on nanoparticles evolution for 13.5% Cr ODS ferritic steel powders by joint application of XAFS and TEM

    Science.gov (United States)

    He, P.; Hoffmann, J.; Möslang, A.

    2018-04-01

    The characteristics of strengthening nanoparticles have a major influence on the mechanical property and irradiation resistance of oxide dispersion strengthened (ODS) steels. To determine how to control nanoparticles evolution, 0.3% Ti with 0.3% Y2O3 were added in 13.5%Cr pre-alloyed steel powders via different milling and consolidation conditions, then characterized by transmission electron microscopy (TEM) and X-ray absorption fine structure (XAFS) at synchrotron irradiation facility. The dissolution of Y2O3 is greatly dependent on the milling time at fixed milling speeds. After 24 h of milling, only minor amounts of the initially added Y2O3 dissolve into the steel matrix whereas TEM results reveal nearly complete dissolution of Y2O3 in 80-h-milled powder. The annealed powder FT-A800 (at 800 °C for 1 h) exhibits a structure near to the initially added Y2O3. The slightly deviation may be accounted for considerable lattice distortion related to the presence of atomic vacancies or formation of Y-Ti-O nucleus. The annealed powders FT-A1000 and FT-A1100 contain complex mixtures of Y-O/Y-Ti-O oxides, which cannot be fitted by any single thermally stable compounds. The coordination numbers of these first two shells in the annealed powders significantly raise as a function of the annealing temperature, indicating the formation of more ordered Y-O or Y-Ti-O particles. The extended X-ray absorption fine structure (EXAFS) spectrum could not necessarily distinguish the dominant oxide species.

  7. Plasticity margin recovery during annealing after cold deformation

    International Nuclear Information System (INIS)

    Bogatov, A.A.; Smirnov, S.V.; Kolmogorov, V.L.

    1978-01-01

    Restoration of the plasticity margin in steel 20 after cold deformation and annealing at 550 - 750 C and soaking for 5 - 300 min was investigated. The conditions of cold deformation under which the metal acquires microdefects unhealed by subsequent annealing were determined. It was established that if the degree of utilization of the plasticity margin is psi < 0.5, the plasticity margin in steel 20 can be completely restored by annealing. A mathematical model of restoration of the plasticity margin by annealing after cold deformation was constructed. A statistical analysis showed good agreement between model and experiment

  8. Quantum Annealing and Quantum Fluctuation Effect in Frustrated Ising Systems

    OpenAIRE

    Tanaka, Shu; Tamura, Ryo

    2012-01-01

    Quantum annealing method has been widely attracted attention in statistical physics and information science since it is expected to be a powerful method to obtain the best solution of optimization problem as well as simulated annealing. The quantum annealing method was incubated in quantum statistical physics. This is an alternative method of the simulated annealing which is well-adopted for many optimization problems. In the simulated annealing, we obtain a solution of optimization problem b...

  9. Annealing properties of potato starches with different degrees of phosphorylation

    DEFF Research Database (Denmark)

    Muhrbeck, Per; Svensson, E

    1996-01-01

    Changes in the gelatinization temperature interval and gelatinization enthalpy with annealing time at 50 degrees C were followed for a number of potato starch samples, with different degrees of phosphorylation, using differential scanning calorimetry. The gelatinization temperature increased...

  10. The influence of annealing on manganese implanted GaAs films

    International Nuclear Information System (INIS)

    Buerger, Danilo; Zhou, Shengqiang; Grenzer, Joerg; Reuther, Helfried; Anwand, Wolfgang; Gottschalch, Volker; Helm, Manfred; Schmidt, Heidemarie

    2009-01-01

    Besides low-temperature molecular beam epitaxy, ion implantation provides an alternative route to incorporate Mn into GaAs above the equilibrium solubility limit. Recently, Mn implanted GaAs diluted magnetic semiconductor was obtained by pulsed laser annealing. However, post-implantation annealing can lead to the formation of secondary phases. In order to compare the post-annealing effect, we investigate GaMnAs by implanting up to 6 at% Mn followed by rapid thermal and flashlamp annealing. The structural properties were probed by high resolution X-ray diffraction. The magnetic properties were determined by SQUID measurements. Auger electron spectroscopy has been used to profile the depth distribution of Mn in GaAs after implantation and annealing. We elucidate after implantation a loss of As and that during rapid thermal annealing most of the Mn diffuses towards the surface. Flash lamp annealing prevents out-diffusion, but the recrystallisation efficiency is low. Only the flash lamp annealed samples reveal weak ferromagnetism.

  11. Susceptor and proximity rapid thermal annealing of InP

    International Nuclear Information System (INIS)

    Katz, A.; Pearton, S.J.; Geva, M.

    1990-01-01

    This paper presents a comparison between the efficiency of InP rapid thermal annealing within two types of SiC-coated graphite susceptors and by using the more conventional proximity approach, in providing degradation-free substrate surface morphology. The superiority of annealing within a susceptor was clearly demonstrated through the evaluation of AuGe contact performance to carbon-implanted InP substrates, which were annealed to activate the implants prior to the metallization. The susceptor annealing provided better protection against edge degradation, slip formation and better surface morphology, due to the elimination of P outdiffusion and pit formation. The two SiC-coated susceptors that were evaluated differ from each other in their geometry. The first type must be charged with the group V species prior to any annealing cycle. Under the optimum charging conditions, effective surface protection was provided only to one anneal (750 degrees C, 10s) of InP before charging was necessary. The second contained reservoirs for provision of the group V element partial pressure, enabled high temperature annealing at the InP without the need for continual recharging of the susceptor. Thus, one has the ability to subsequentially anneal a lot of InP wafers at high temperatures without inducing any surface deterioration

  12. Effects of thermal annealing on the electrical characteristics of In-Ga-Zn-O thin-film transistors with Al2O3 gate dielectric

    International Nuclear Information System (INIS)

    Zhang, Wen-Peng; Chen, Sun; Qian, Shi-Bing; Ding, Shi-Jin

    2015-01-01

    We studied how the performance of In–Ga–Zn–O (IGZO) thin film transistors (TFTs) with Al 2 O 3 gate insulator was affected by post-fabrication annealing temperature and annealing time. At a fixed annealing time of 2 min, the IGZO TFT exhibited the best transfer and output characteristics in the case of 300 °C in N 2 atmosphere, which is attributed to the achievement of appropriate carrier concentration and Hall mobility in the IGZO film. Further, it was found that both of the carrier concentration and Hall mobility in the IGZO film increased with the increment of annealing temperature. For the annealing temperature of 300 °C, the performance of the IGZO TFT was further improved by extending annealing time to 5 min, i.e., the field effect mobility, sub-threshold swing and on/off current ratio were 11.6 cm 2 /(V · s), 0.42 V dec −1 and 10 6 , respectively. The underlying mechanism was discussed. (paper)

  13. Optical scattering characteristic of annealed niobium oxide films

    International Nuclear Information System (INIS)

    Lai Fachun; Li Ming; Wang Haiqian; Hu Hailong; Wang Xiaoping; Hou, J.G.; Song Yizhou; Jiang Yousong

    2005-01-01

    Niobium oxide (Nb 2 O 5 ) films with thicknesses ranging from 200 to 1600 nm were deposited on fused silica at room temperature by low frequency reactive magnetron sputtering system. In order to study the optical losses resulting from the microstructures, the films with 500 nm thickness were annealed at temperatures between 600 and 1100 deg. C, and films with thicknesses from 200 to 1600 nm were annealed at 800 deg. C. Scanning electron microscopy and atomic force microscopy images show that the root mean square of surface roughness, the grain size, voids, microcracks, and grain boundaries increase with increasing both the annealing temperature and the thickness. Correspondingly, the optical transmittance and reflectance decrease, and the optical loss increases. The mechanisms of the optical losses are discussed. The results suggest that defects in the volume and the surface roughness should be the major source for the optical losses of the annealed films by causing pronounced scattering. For samples with a determined thickness, there is a critical annealing temperature, above which the surface scattering contributes to the major optical losses. In the experimental scope, for the films annealed at temperatures below 900 deg. C, the major optical losses resulted from volume scattering. However, surface roughness was the major source for the optical losses when the 500-nm films were annealed at temperatures above 900 deg. C

  14. Annealing Kinetic Model Using Fast and Slow Metastable Defects for Hydrogenated-Amorphous-Silicon-Based Solar Cells

    Directory of Open Access Journals (Sweden)

    Seung Yeop Myong

    2007-01-01

    Full Text Available The two-component kinetic model employing “fast” and “slow” metastable defects for the annealing behaviors in pin-type hydrogenated-amorphous-silicon- (a-Si:H- based solar cells is simulated using a normalized fill factor. Reported annealing data on pin-type a-Si:H-based solar cells are revisited and fitted using the model to confirm its validity. It is verified that the two-component model is suitable for fitting the various experimental phenomena. In addition, the activation energy for annealing of the solar cells depends on the definition of the recovery time. From the thermally activated and high electric field annealing behaviors, the plausible microscopic mechanism on the defect removal process is discussed.

  15. Improvement on the electrical characteristics of Pd/HfO2/6H-SiC MIS capacitors using post deposition annealing and post metallization annealing

    Science.gov (United States)

    Esakky, Papanasam; Kailath, Binsu J.

    2017-08-01

    HfO2 as a gate dielectric enables high electric field operation of SiC MIS structure and as gas sensor HfO2/SiC capacitors offer higher sensitivity than SiO2/SiC capacitors. The issue of higher density of oxygen vacancies and associated higher leakage current necessitates better passivation of HfO2/SiC interface. Effect of post deposition annealing in N2O plasma and post metallization annealing in forming gas on the structural and electrical characteristics of Pd/HfO2/SiC MIS capacitors are reported in this work. N2O plasma annealing suppresses crystallization during high temperature annealing thereby improving the thermal stability and plasma annealing followed by rapid thermal annealing in N2 result in formation of Hf silicate at the HfO2/SiC interface resulting in order of magnitude lower density of interface states and gate leakage current. Post metallization annealing in forming gas for 40 min reduces interface state density by two orders while gate leakage current density is reduced by thrice. Post deposition annealing in N2O plasma and post metallization annealing in forming gas are observed to be effective passivation techniques improving the electrical characteristics of HfO2/SiC capacitors.

  16. Multifragment emission times in Xe induced reactions

    Energy Technology Data Exchange (ETDEWEB)

    Moroni, A. [INFN and Dipartimento di Fisica, Via Celoria 16, 20133 Milano (Italy); Bowman, D.R. [AECL Research, Chalk River Laboratories, Chalk River, Ont. (Canada); Bruno, M. [Dipartimento di Fisica and INFN, Via Irnerio 46, 40126 Bologna (Italy); Buttazzo, P. [Dipartimento di Fisica and INFN, Via A. Valerio 2, 34127 Trieste (Italy); Celano, L. [INFN, Via Amendola 173, 70126 Bari (Italy); Colonna, N. [INFN, Via Amendola 173, 70126 Bari (Italy); D`Agostino, M. [Dipartimento di Fisica and INFN, Via Irnerio 46, 40126 Bologna (Italy); Dinius, J.D. [NSCL, Michigan State University, E. Lansing, 48824 MI (United States); Ferrero, A. [INFN and Dipartimento di Fisica, Via Celoria 16, 20133 Milano (Italy); Fiandri, M.L. [Dipartimento di Fisica and INFN, Via Irnerio 46, 40126 Bologna (Italy); Gelbke, K. [NSCL, Michigan State University, E. Lansing, 48824 MI (United States); Glasmacher, T. [NSCL, Michigan State University, E. Lansing, 48824 MI (United States); Gramegna, F. [INFN Laboratori Nazionali di Legnaro, Via Romea 4, 35020 Legnaro (Italy); Handzy, D.O. [NSCL, Michigan State University, E. Lansing, 48824 MI (United States); Horn, D. [AECL Research, Chalk River Laboratories, Chalk River, Ont. (Canada); Hsi Wenchien [NSCL, Michigan State University, E. Lansing, 48824 MI (United States); Huang, M. [NSCL, Michigan State University, E. Lansing, 48824 MI (United States); Iori, I. [INFN and Dipartimento di Fisica, Via Celoria 16, 20133 Milano (Italy); Lisa, M. [NSCL, Michigan State University, E. Lansing, 48824 MI (United States); Lynch, W.G. [NSCL, Michigan State University, E. Lansing, 48824 MI (United States); Margagliotti, G.V. [Dipartimento di Fisica and INFN, Via A. Valerio 2, 34127 Trieste (Italy); Mastinu, P.F. [Dipartimento di Fisica and INFN, Via Irnerio 46, 40126 Bologna (Italy); Milazzo, P.M. [Dipartimento di Fisica and INFN, Via Irnerio 46, 40126 Bologna (Italy); Montoya, C.

    1995-02-06

    Multifragment emission is studied in {sup 129}Xe+{sup nat}Cu reactions. The emission process for central collisions occurs on a time scale of similar 200fm/c at 30MeV/n. Intermediate-mass-fragment yields, velocity correlation functions and emission velocities of Z=6 fragments are compared with predictions of statistical decay models. ((orig.)).

  17. Impact of soft annealing on the performance of solution-processed amorphous zinc tin oxide thin-film transistors

    KAUST Repository

    Nayak, Pradipta K.

    2013-05-08

    It is demonstrated that soft annealing duration strongly affects the performance of solution-processed amorphous zinc tin oxide thin-film transistors. Prolonged soft annealing times are found to induce two important changes in the device: (i) a decrease in zinc tin oxide film thickness, and (ii) an increase in oxygen vacancy concentration. The devices prepared without soft annealing exhibited inferior transistor performances, in comparison to devices in which the active channel layer (zinc tin oxide) was subjected to soft annealing. The highest saturation field-effect mobility - 5.6 cm2 V-1 s-1 with a drain-to-source on-off current ratio (Ion/Ioff) of 2 × 108 - was achieved in the case of devices with 10-min soft-annealed zinc tin oxide thin films as the channel layer. The findings of this work identify soft annealing as a critical parameter for the processing of chemically derived thin-film transistors, and it correlates device performance to the changes in material structure induced by soft annealing. © 2013 American Chemical Society.

  18. Optimization of pressurized water reactor shuffling by simulated annealing with heuristics

    International Nuclear Information System (INIS)

    Stevens, J.G.; Smith, K.S.; Rempe, K.R.; Downar, T.J.

    1995-01-01

    Simulated-annealing optimization of reactor core loading patterns is implemented with support for design heuristics during candidate pattern generation. The SIMAN optimization module uses the advanced nodal method of SIMULATE-3 and the full cross-section detail of CASMO-3 to evaluate accurately the neutronic performance of each candidate, resulting in high-quality patterns. The use of heuristics within simulated annealing is explored. Heuristics improve the consistency of optimization results for both fast- and slow-annealing runs with no penalty from the exclusion of unusual candidates. Thus, the heuristic application of designer judgment during automated pattern generation is shown to be effective. The capability of the SIMAN module to find and evaluate families of loading patterns that satisfy design constraints and have good objective performance within practical run times is demonstrated. The use of automated evaluations of successive cycles to explore multicycle effects of design decisions is discussed

  19. Delta-electron spectroscopy: An aid for the determination of reaction times in heavy ion reactions

    International Nuclear Information System (INIS)

    Skapa, H.

    1983-01-01

    For the systems I->Au and I->Bi at an incident energy of 6.2 MeV/u (I->Au) and 6.6 MeV/u (I->Bi) the emission probability of delta electrons was determined. In an energy range from 150 KeV to 1000 KeV electrons were spectroscoped in coincidence to elastically, quasielastically, and deep inelastically scattered ions. In deep inelastic reaction between reaction products with high and without a mean mass drift was discriminated. The contribution of the conversion electrons, determined from gamma spectra, extends in the range of deep inelastic reactions of about 60%. While the ratio of conversion electrons for deep inelastic events with large to such without mass drift shows a flat, monotoneous growth for the ratio of the measured emission probabilities a oscillation-like structure with about 400 KeV width results. An interpretation of this structure as interference effect by nuclear time delay yields for the case of large mass drift a nuclear retention time of 7.5 x 10 -21 s. (orig./HSI) [de

  20. Carrier capture efficiency in InGaN/GaN LEDs: Role of high temperature annealing

    Science.gov (United States)

    Vinattieri, A.; Batignani, F.; Bogani, F.; Meneghini, M.; Meneghesso, G.; Zanoni, E.; Zhu, D.; Humphreys, C. J.

    2014-02-01

    By means of time integrated (TI), time-resolved (TR) photoluminescence (PL) and PL excitation spectra, we investigate the role of an high temperature post-growth thermal annealing (TA) on a set of InGaN/GaN LED structures with different dislocation densities. We provide evidence of the nature of the radiative recombination from a wide distribution of non-interacting localised states and we show the beneficial effect of thermal annealing in reducing the contribution of non-radiative recombination in the well region.

  1. Carrier capture efficiency in InGaN/GaN LEDs: Role of high temperature annealing

    Energy Technology Data Exchange (ETDEWEB)

    Vinattieri, A.; Batignani, F. [Dipartimento di Fisica e Astronomia, LENS, CNISM, Università di Firenze (Italy); Bogani, F. [Dipartimento di Ingegneria Industriale, Università di Firenze (Italy); Meneghini, M.; Meneghesso, G.; Zanoni, E. [Dipartimento di Ingegneria dell' Informazione, Università di Padova (Italy); Zhu, D.; Humphreys, C. J. [Department Materials Science, University of Cambridge, Cambridge, CB2 3QZ (United Kingdom)

    2014-02-21

    By means of time integrated (TI), time-resolved (TR) photoluminescence (PL) and PL excitation spectra, we investigate the role of an high temperature post-growth thermal annealing (TA) on a set of InGaN/GaN LED structures with different dislocation densities. We provide evidence of the nature of the radiative recombination from a wide distribution of non-interacting localised states and we show the beneficial effect of thermal annealing in reducing the contribution of non-radiative recombination in the well region.

  2. Improvement on the electrical characteristics of Pd/HfO{sub 2}/6H-SiC MIS capacitors using post deposition annealing and post metallization annealing

    Energy Technology Data Exchange (ETDEWEB)

    Esakky, Papanasam, E-mail: papanasamte@gmail.com; Kailath, Binsu J

    2017-08-15

    Highlights: • Post deposition annealing (PDA) and post metallization annealing (PMA) on the electrical characteristics of Pd/HfO{sub 2}/6H-SiC MIS capacitors. • Post deposition N{sub 2}O plasma annealing inhibits crystallization of HfO{sub 2} during high temperature annealing. • Plasma annealing followed by RTA in N{sub 2} results in formation of hafnium silicate at the HfO{sub 2}-SiC interface. • PDA reduces interface state density (D{sub it}) and gate leakage current density (J{sub g}) by order. • PMA in forming gas for 40 min results in better passivation and reduces D{sub it} by two orders and J{sub g} by thrice. - Abstract: HfO{sub 2} as a gate dielectric enables high electric field operation of SiC MIS structure and as gas sensor HfO{sub 2}/SiC capacitors offer higher sensitivity than SiO{sub 2}/SiC capacitors. The issue of higher density of oxygen vacancies and associated higher leakage current necessitates better passivation of HfO{sub 2}/SiC interface. Effect of post deposition annealing in N{sub 2}O plasma and post metallization annealing in forming gas on the structural and electrical characteristics of Pd/HfO{sub 2}/SiC MIS capacitors are reported in this work. N{sub 2}O plasma annealing suppresses crystallization during high temperature annealing thereby improving the thermal stability and plasma annealing followed by rapid thermal annealing in N{sub 2} result in formation of Hf silicate at the HfO{sub 2}/SiC interface resulting in order of magnitude lower density of interface states and gate leakage current. Post metallization annealing in forming gas for 40 min reduces interface state density by two orders while gate leakage current density is reduced by thrice. Post deposition annealing in N{sub 2}O plasma and post metallization annealing in forming gas are observed to be effective passivation techniques improving the electrical characteristics of HfO{sub 2}/SiC capacitors.

  3. Laser annealing of ion implanted silicon

    International Nuclear Information System (INIS)

    White, C.W.; Narayan, J.; Young, R.T.

    1978-11-01

    The physical and electrical properties of ion implanted silicon annealed with high powered ruby laser radiation are summarized. Results show that pulsed laser annealing can lead to a complete removal of extended defects in the implanted region accompanied by incorporation of dopants into lattice sites even when their concentration far exceeds the solid solubility limit

  4. Study of annealing effects in Al–Sb bilayer thin films

    Indian Academy of Sciences (India)

    There are three methods to prepare compound semiconductor systems: bilayer annealing (Singh and Vijay 2004a), rapid thermal annealing (Singh and Vijay 2004b) and ion beam mixing (Dhar et al 2003). The annealing and ion beam mixing were found to show inferior mixing effects compared to rapid thermal annealing.

  5. Microstructure evolution during annealing of TiAl/NiCoCrAl multilayer composite prepared by EB-PVD

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Rubing, E-mail: zrb86411680@126.com [Department of Mechanics, School of Civil Engineering, Beijing Jiaotong University, Beijing 100044 (China); Zhang, Deming [Beijing General Research Institute of Mining and Metallurgy, Beijing 100044 (China); Chen, Guiqing [Center for Composite Materials, Harbin Institute of Technology, Harbin 150001 (China); Wang, Yuesheng [Department of Mechanics, School of Civil Engineering, Beijing Jiaotong University, Beijing 100044 (China)

    2014-07-01

    TiAl/NiCoCrAl laminate composite sheet with a thickness of 0.4–0.6 mm as well as a dimension of 150 mm × 100 mm was fabricated successfully by using electron beam physical vapor deposition (EB-PVD) method. The annealing treatment was processed at 1123 and 1323 K for 3 h in a high vacuum atmosphere, respectively. The phase composition and microstructure of TiAl/NiCoCrAl microlaminated sheet have been analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Based on the sheet characterization and results of the microstructure evolution during annealing treatment process, the diffusion mechanism of interfacial reaction in TiAl/NiCoCrAl microlaminate was investigated and discussed.

  6. Rapid thermal annealing of FePt and FePt/Cu thin films

    Energy Technology Data Exchange (ETDEWEB)

    Brombacher, Christoph

    2011-01-10

    Chemically ordered FePt is one of the most promising materials to reach the ultimate limitations in storage density of future magnetic recording devices due to its high uniaxial magnetocrystalline anisotropy and a corrosion resistance superior to rare-earth based magnets. In this study, FePt and FePt/Cu bilayers have been sputter deposited at room temperature onto thermally oxidized silicon wafers, glass substrates and self-assembled arrays of spherical SiO{sub 2} particles with diameters down to 10 nm. Millisecond flash lamp annealing, as well as conventional rapid thermal annealing was employed to induce the phase transformation from the chemically disordered A1 phase into the chemically ordered L1{sub 0} phase. The influence of the annealing temperature, annealing time and the film thickness on the ordering transformation and (001) texture evolution of FePt films with near equiatomic composition was studied. Whereas flash lamp annealed FePt films exhibit a polycrystalline morphology with high chemical L1{sub 0} order, rapid thermal annealing can lead to the formation of chemically ordered FePt films with (001) texture on amorphous SiO{sub 2}/Si substrates. The resultant high perpendicular magnetic anisotropy and large coercivities up to 40 kOe are demonstrated. Simultaneously to the ordering transformation, rapid thermal annealing to temperatures exceeding 600 C leads to a break up of the continuous FePt film into separated islands. This dewetting behavior was utilized to create regular arrays of FePt nanostructures on SiO{sub 2} particle templates with periods down to 50 nm. The addition of Cu improves the (001) texture formation and chemical ordering for annealing temperatures T{sub a} {<=}600 C. In addition, the magnetic anisotropy and the coercivity of the ternary FePtCu alloy can be effectively tailored by adjusting the Cu content. The prospects of FePtCu based exchange spring media, as well as the magnetic properties of FePtCu nanostructures fabricated

  7. Enhanced off-resonance magnetoelectric response in laser annealed PZT thick film grown on magnetostrictive amorphous metal substrate

    Energy Technology Data Exchange (ETDEWEB)

    Palneedi, Haribabu [Materials Interface Laboratory, Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701 (Korea, Republic of); Functional Ceramics Group, Korea Institute of Materials Science (KIMS), Changwon 641-831 (Korea, Republic of); Maurya, Deepam; Priya, Shashank [Bio-inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061 (United States); Kim, Gi-Yeop; Choi, Si-Young, E-mail: youngchoi@kims.re.kr [Materials Modeling and Characterization Department, Korea Institute of Materials Science (KIMS), Changwon 641-831 (Korea, Republic of); Kang, Suk-Joong L. [Materials Interface Laboratory, Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701 (Korea, Republic of); Kim, Kwang-Ho [School of Materials Science and Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Ryu, Jungho, E-mail: jhryu@kims.re.kr [Functional Ceramics Group, Korea Institute of Materials Science (KIMS), Changwon 641-831 (Korea, Republic of)

    2015-07-06

    A highly dense, 4 μm-thick Pb(Zr,Ti)O{sub 3} (PZT) film is deposited on amorphous magnetostrictive Metglas foil (FeBSi) by granule spray in vacuum process at room temperature, followed by its localized annealing with a continuous-wave 560 nm ytterbium fiber laser radiation. This longer-wavelength laser radiation is able to anneal the whole of thick PZT film layer without any deteriorative effects, such as chemical reaction and/or atomic diffusion, at the interface and crystallization of amorphous Metglas substrate. Greatly enhanced dielectric and ferroelectric properties of the annealed PZT are attributed to its better crystallinity and grain growth induced by laser irradiation. As a result, a colossal off-resonance magnetoelectric (ME) voltage coefficient that is two orders of magnitude larger than previously reported output from PZT/Metglas film-composites is achieved. The present work addresses the problems involved in the fabrication of PZT/Metglas film-composites and opens up emerging possibilities in employing piezoelectric materials with low thermal budget substrates (suitable for integrated electronics) and designing laminate composites for ME based devices.

  8. Time asymmetry: Polarization and analyzing power in the nuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Rioux, C.; Roy, R.; Slobodrian, R.J. (Laval Univ., Quebec City (Canada). Lab. de Physique Nucleaire); Conzett, H.E. (California Univ., Berkeley (USA). Lawrence Berkeley Lab.)

    1983-02-28

    Measurements of the proton polarization in the reactions /sup 7/Li(/sup 3/He, p vector)/sup 9/Be and /sup 9/Be(/sup 3/He, p vector)/sup 11/B and of the analyzing powers of the inverse reactions, initiated by polarized protons at the same c.m. energies, show significant differences which imply the failure of the polarization-analyzing-power theorem and, prima facie, of time-reversal invariance in these reactions. The reaction /sup 2/H(/sup 3/He, p vector)/sup 4/ He and its inverse have also been investigated and show some smaller differences. A discussion of the instrumental asymmetries is presented.

  9. Enhancing GMI properties of melt-extracted Co-based amorphous wires by twin-zone Joule annealing

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J.S.; Cao, F.Y.; Xing, D.W.; Zhang, L.Y. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Qin, F.X. [Advanced Composite Center for Innovation and Science (ACCIS), Department of Aerospace Engineering, University of Bristol, University Walk, Bristol BS8 1TR (United Kingdom); Peng, H.X. [Advanced Composite Center for Innovation and Science (ACCIS), Department of Aerospace Engineering, University of Bristol, University Walk, Bristol BS8 1TR (United Kingdom); Centre for Nanoscience and Quantum Information, University of Bristol, Tyndall Avenue, Bristol BS8 1FD (United Kingdom); Xue, X. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Sun, J.F., E-mail: jfsun_hit@263.net [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer GMI effect is closely related to annealed microstructures observed by HRTEM. Black-Right-Pointing-Pointer Twin-zone Joule-heated annealing (TJHA) as a novel effective annealing treatment. Black-Right-Pointing-Pointer TJHA wires have relatively larger GMI ratio and field sensitivity. Black-Right-Pointing-Pointer From HRTEM perspective to explain the GMI peaks feature of different states wires. Black-Right-Pointing-Pointer TJHA wires are useful for high-resolution magnetic sensor applications. - Abstract: The influence of twin-zone Joule annealing (TJA) on the microstructure and magnetic properties of melt-extracted Co{sub 68.2}Fe{sub 4.3}B{sub 15}Si{sub 12.5} amorphous microwires has been investigated. Experimental results indicated that twin-zone Joule annealing treatment improved the GMI property of as-cast wires to a greater extent comparing with Joule annealing (JA) and conventional vacuum annealing (CVA) techniques. At 15 MHz, e.g., the maximum GMI ratio [{Delta}Z/Z{sub 0}]{sub max} of a TJA wire increases to 104.29%, which is more than 5 times of 20.49% for the as-cast wire, nearly two times of 56.47% for the JA wire, while the CVA wire has a decreased GMI ratio; the field response sensitivity of the TJA wire increased to 171.62%/Oe from 80.32%/Oe for the as-cast wire, exceeding the values of 140.76%/Oe for the JA wire and of 39.17%/Oe for the CVA wire. The stress or structural relaxation in TJA wire increases circumferential permeability, and magnetic moment achieves a critical state of excitation for overcoming eddy-current damping or 'nail-sticked' action in rotational magnetization process at relatively high frequency. From the microstructural point of view, the role of regularly arranged atomic micro-regions (RAAM) and of medium range order region (MROR) determines the efficiency of various annealing techniques. Conclusively, TJA is established as an efficient annealing technique to enhance the GMI effect

  10. An Improved Simulated Annealing Technique for Enhanced Mobility in Smart Cities

    Directory of Open Access Journals (Sweden)

    Hayder Amer

    2016-06-01

    Full Text Available Vehicular traffic congestion is a significant problem that arises in many cities. This is due to the increasing number of vehicles that are driving on city roads of limited capacity. The vehicular congestion significantly impacts travel distance, travel time, fuel consumption and air pollution. Avoidance of traffic congestion and providing drivers with optimal paths are not trivial tasks. The key contribution of this work consists of the developed approach for dynamic calculation of optimal traffic routes. Two attributes (the average travel speed of the traffic and the roads’ length are utilized by the proposed method to find the optimal paths. The average travel speed values can be obtained from the sensors deployed in smart cities and communicated to vehicles via the Internet of Vehicles and roadside communication units. The performance of the proposed algorithm is compared to three other algorithms: the simulated annealing weighted sum, the simulated annealing technique for order preference by similarity to the ideal solution and the Dijkstra algorithm. The weighted sum and technique for order preference by similarity to the ideal solution methods are used to formulate different attributes in the simulated annealing cost function. According to the Sheffield scenario, simulation results show that the improved simulated annealing technique for order preference by similarity to the ideal solution method improves the traffic performance in the presence of congestion by an overall average of 19.22% in terms of travel time, fuel consumption and CO2 emissions as compared to other algorithms; also, similar performance patterns were achieved for the Birmingham test scenario.

  11. An Improved Simulated Annealing Technique for Enhanced Mobility in Smart Cities.

    Science.gov (United States)

    Amer, Hayder; Salman, Naveed; Hawes, Matthew; Chaqfeh, Moumena; Mihaylova, Lyudmila; Mayfield, Martin

    2016-06-30

    Vehicular traffic congestion is a significant problem that arises in many cities. This is due to the increasing number of vehicles that are driving on city roads of limited capacity. The vehicular congestion significantly impacts travel distance, travel time, fuel consumption and air pollution. Avoidance of traffic congestion and providing drivers with optimal paths are not trivial tasks. The key contribution of this work consists of the developed approach for dynamic calculation of optimal traffic routes. Two attributes (the average travel speed of the traffic and the roads' length) are utilized by the proposed method to find the optimal paths. The average travel speed values can be obtained from the sensors deployed in smart cities and communicated to vehicles via the Internet of Vehicles and roadside communication units. The performance of the proposed algorithm is compared to three other algorithms: the simulated annealing weighted sum, the simulated annealing technique for order preference by similarity to the ideal solution and the Dijkstra algorithm. The weighted sum and technique for order preference by similarity to the ideal solution methods are used to formulate different attributes in the simulated annealing cost function. According to the Sheffield scenario, simulation results show that the improved simulated annealing technique for order preference by similarity to the ideal solution method improves the traffic performance in the presence of congestion by an overall average of 19.22% in terms of travel time, fuel consumption and CO₂ emissions as compared to other algorithms; also, similar performance patterns were achieved for the Birmingham test scenario.

  12. Annealing of Al implanted 4H silicon carbide

    International Nuclear Information System (INIS)

    Hallen, A; Suchodolskis, A; Oesterman, J; Abtin, L; Linnarsson, M

    2006-01-01

    Al ions were implanted with multiple energies up to 250 keV at elevated temperatures in n-type 4H SiC epitaxial layers to reach a surface concentration of 1x10 20 cm -3 . These samples were then annealed at temperatures between 1500 and 1950 deg. C. A similar 4H SiC epitaxial sample was implanted by MeV Al ions to lower doses and annealed only at 200 and 400 deg. C. After annealing, cross-sections of the samples were characterized by scanning spreading resistance microscopy (SSRM). The results show that the resistivity of high-dose Al implanted samples has not reached a saturated value, even after annealing at the highest temperature. For the MeV Al implanted sample, the activation of Al has not yet started, but a substantial annealing of the implantation induced damage can be seen from the SSRM depth profiles

  13. Neutron Scattering in Hydrogenous Moderators, Studied by Time Dependent Reaction Rate Method

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, L G; Moeller, E; Purohit, S N

    1966-03-15

    The moderation and absorption of a neutron burst in water, poisoned with the non-1/v absorbers cadmium and gadolinium, has been followed on the time scale by multigroup calculations, using scattering kernels for the proton gas and the Nelkin model. The time dependent reaction rate curves for each absorber display clear differences for the two models, and the separation between the curves does not depend much on the absorber concentration. An experimental method for the measurement of infinite medium reaction rate curves in a limited geometry has been investigated. This method makes the measurement of the time dependent reaction rate generally useful for thermalization studies in a small geometry of a liquid hydrogenous moderator, provided that the experiment is coupled to programs for the calculation of scattering kernels and time dependent neutron spectra. Good agreement has been found between the reaction rate curve, measured with cadmium in water, and a calculated curve, where the Haywood kernel has been used.

  14. Shrinking of silicon nanocrystals embedded in an amorphous silicon oxide matrix during rapid thermal annealing in a forming gas atmosphere

    Science.gov (United States)

    van Sebille, M.; Fusi, A.; Xie, L.; Ali, H.; van Swaaij, R. A. C. M. M.; Leifer, K.; Zeman, M.

    2016-09-01

    We report the effect of hydrogen on the crystallization process of silicon nanocrystals embedded in a silicon oxide matrix. We show that hydrogen gas during annealing leads to a lower sub-band gap absorption, indicating passivation of defects created during annealing. Samples annealed in pure nitrogen show expected trends according to crystallization theory. Samples annealed in forming gas, however, deviate from this trend. Their crystallinity decreases for increased annealing time. Furthermore, we observe a decrease in the mean nanocrystal size and the size distribution broadens, indicating that hydrogen causes a size reduction of the silicon nanocrystals.

  15. Burst annealing of high temperature GaAs solar cells

    Science.gov (United States)

    Brothers, P. R.; Horne, W. E.

    1991-01-01

    One of the major limitations of solar cells in space power systems is their vulnerability to radiation damage. One solution to this problem is to periodically heat the cells to anneal the radiation damage. Annealing was demonstrated with silicon cells. The obstacle to annealing of GaAs cells was their susceptibility to thermal damage at the temperatures required to completely anneal the radiation damage. GaAs cells with high temperature contacts and encapsulation were developed. The cells tested are designed for concentrator use at 30 suns AMO. The circular active area is 2.5 mm in diameter for an area of 0.05 sq cm. Typical one sun AMO efficiency of these cells is over 18 percent. The cells were demonstrated to be resistant to damage after thermal excursions in excess of 600 C. This high temperature tolerance should allow these cells to survive the annealing of radiation damage. A limited set of experiments were devised to investigate the feasibility of annealing these high temperature cells. The effect of repeated cycles of electron and proton irradiation was tested. The damage mechanisms were analyzed. Limitations in annealing recovery suggested improvements in cell design for more complete recovery. These preliminary experiments also indicate the need for further study to isolate damage mechanisms. The primary objective of the experiments was to demonstrate and quantify the annealing behavior of high temperature GaAs cells. Secondary objectives were to measure the radiation degradation and to determine the effect of repeated irradiation and anneal cycles.

  16. Burst annealing of high temperature GaAs solar cells

    International Nuclear Information System (INIS)

    Brothers, P.R.; Horne, W.E.

    1991-01-01

    One of the major limitations of solar cells in space power systems is their vulnerability to radiation damage. One solution to this problem is to periodically heat the cells to anneal the radiation damage. Annealing was demonstrated with silicon cells. The obstacle to annealing of GaAs cells was their susceptibility to thermal damage at the temperatures required to completely anneal the radiation damage. GaAs cells with high temperature contacts and encapsulation were developed. The cells tested are designed for concentrator use at 30 suns AMO. The circular active area is 2.5 mm in diameter for an area of 0.05 sq cm. Typical one sun AMO efficiency of these cells is over 18 percent. The cells were demonstrated to be resistant to damage after thermal excursions in excess of 600 degree C. This high temperature tolerance should allow these cells to survive the annealing of radiation damage. A limited set of experiments were devised to investigate the feasibility of annealing these high temperature cells. The effect of repeated cycles of electron and proton irradiation was tested. The damage mechanisms were analyzed. Limitations in annealing recovery suggested improvements in cell design for more complete recovery. These preliminary experiments also indicate the need for further study to isolate damage mechanisms. The primary objective of the experiments was to demonstrate and quantify the annealing behavior of high temperature GaAs cells. Secondary objectives were to measure the radiation degradation and to determine the effect of repeated irradiation and anneal cycles

  17. Formation of oxygen related donors in step-annealed CZ–silicon

    Indian Academy of Sciences (India)

    The effect of step-annealing necessitated by the difficulties being faced in the long duration annealing treatments to be given to CZ–silicon has been studied. One pre-anneal of 10 h followed by annealing of 10 h causes a decrease in the absorption coefficient for carbon (c). Oxygen and carbon both accelerate thermal ...

  18. A note on simulated annealing to computer laboratory scheduling ...

    African Journals Online (AJOL)

    The concepts, principles and implementation of simulated Annealing as a modem heuristic technique is presented. Simulated Annealing algorithm is used in solving real life problem of Computer Laboratory scheduling in order to maximize the use of scarce and insufficient resources. KEY WORDS: Simulated Annealing ...

  19. Improved perovskite phototransistor prepared using multi-step annealing method

    Science.gov (United States)

    Cao, Mingxuan; Zhang, Yating; Yu, Yu; Yao, Jianquan

    2018-02-01

    Organic-inorganic hybrid perovskites with good intrinsic physical properties have received substantial interest for solar cell and optoelectronic applications. However, perovskite film always suffers from a low carrier mobility due to its structural imperfection including sharp grain boundaries and pinholes, restricting their device performance and application potential. Here we demonstrate a straightforward strategy based on multi-step annealing process to improve the performance of perovskite photodetector. Annealing temperature and duration greatly affects the surface morphology and optoelectrical properties of perovskites which determines the device property of phototransistor. The perovskite films treated with multi-step annealing method tend to form highly uniform, well-crystallized and high surface coverage perovskite film, which exhibit stronger ultraviolet-visible absorption and photoluminescence spectrum compare to the perovskites prepared by conventional one-step annealing process. The field-effect mobilities of perovskite photodetector treated by one-step direct annealing method shows mobility as 0.121 (0.062) cm2V-1s-1 for holes (electrons), which increases to 1.01 (0.54) cm2V-1s-1 for that treated with muti-step slow annealing method. Moreover, the perovskite phototransistors exhibit a fast photoresponse speed of 78 μs. In general, this work focuses on the influence of annealing methods on perovskite phototransistor, instead of obtains best parameters of it. These findings prove that Multi-step annealing methods is feasible to prepared high performance based photodetector.

  20. Effect of thermal annealing on electron spin relaxation of beryllium-doped In{sub 0.8}Ga{sub 0.2}As{sub 0.45}P{sub 0.55} bulk

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hao; Harasawa, Ryo; Yasue, Yuya; Aritake, Takanori; Jiang, Canyu; Tackeuchi, Atsushi, E-mail: atacke@waseda.jp [Department of Applied Physics, Waseda University, Shinjuku, Tokyo 169-8555 (Japan); Ji, Lian; Lu, Shulong [Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Dushu Lake Higher Education Town, Ruoshui Road 398, Suzhou Industrial Park, Suzhou (China)

    2016-08-15

    The effect of thermal annealing on the electron spin relaxation of beryllium-doped In{sub 0.8}Ga{sub 0.2}As{sub 0.45}P{sub 0.55} bulk was investigated by time-resolved spin-dependent pump and probe reflection measurement with a high time resolution of 200 fs. Three similar InGaAsP samples were examined one of which was annealed at 800 °C for 1 s, one was annealed at 700 °C for 1 s and the other was not annealed after crystal growth by molecular beam epitaxy. Although the carrier lifetimes of the 700 °C-annealed sample and the unannealed sample were similar, that of the 800 °C-annealed sample was extended to 11.6 (10.4) ns at 10 (300) K, which was more than two (four) times those of the other samples. However, interestingly the spin relaxation time of the 800 °C-annealed sample was found to be similar to those of the other two samples. Particularly at room temperature, the spin relaxation times are 143 ps, 147 ps, and 111 ps for the 800 °C-annealed sample, 700 °C-annealed sample, and the unannealed sample, respectively.

  1. Annealing effect of H+ -implanted single crystal silicon on strain and crystal structure

    International Nuclear Information System (INIS)

    Duo Xinzhong; Liu Weili; Zhang Miao; Gao Jianxia; Fu Xiaorong; Lin Chenglu

    2000-01-01

    The work focuses on the rocking curves of H + -implanted single silicon crystal detected by Four-Crystal X-ray diffractometer. The samples were annealed under different temperatures. Lattice defect in H + -implanted silicon crystals was detected by Rutherford Backscattering Spectrometry. It appeared that H-related complex did not crush until annealing temperature reached about 400 degree C. At that temperature H 2 was formed, deflated in silicon lattice and strained the lattice. But defects did not come into being in large quantity. The lattice was undamaged. When annealing temperature reached 500 degree C, strain induced by H 2 deflation crashed the silicon lattice. A large number of defects were formed. At the same time bubbles in the crystal and blister/flaking on the surface could be observed

  2. Quantitative analysis of swelling on annealing of hydrogen ion implanted diamond single crystals

    International Nuclear Information System (INIS)

    Kuznetsov, G.F.

    2006-01-01

    Local swelling observed upon high-temperature annealing of natural diamond single crystals implanted by 350-keV hydrogen ions with a dose of 12 10 16 cm 2 is studied. Based on room-temperature measurements, Griffith cracking criterion in combination with gas law, model quantitative calculations of the swelling size and the amount of hydrogen molecules in a swelling have been carried out for the first time. At room temperature, T 1 293 K, the amount of local elastic stresses in the upper layer of the diamond is counterbalanced by inner hydrogen pressure. Behavior of the gas bubbles with the annealing temperature increase up to 1693 K and repeated annealing at a temperature of 1743 K has been calculated [ru

  3. Electron backscatter and X-ray diffraction studies on the deformation and annealing textures of austenitic stainless steel 310S

    Energy Technology Data Exchange (ETDEWEB)

    Nezakat, Majid, E-mail: majid.nezakat@usask.ca [Canadian Light Source Inc., 44 Innovation Boulevard, Saskatoon, SK, S7N 2V3 (Canada); Akhiani, Hamed [Westpower Equipment Ltd., 4451 54 Avenue South East, Calgary, AB T2C 2A2 (Canada); Sabet, Seyed Morteza [Department of Ocean and Mechanical Engineering, Florida Atlantic University, Boca Raton, FL 33431 (United States); Szpunar, Jerzy [Department of Mechanical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK, S7N 5A9 (Canada)

    2017-01-15

    We studied the texture evolution of thermo-mechanically processed austenitic stainless steel 310S. This alloy was cold rolled up to 90% reduction in thickness and subsequently annealed at 1050 °C. At the early stages of deformation, strain-induced martensite was formed from deformed austenite. By increasing the deformation level, slip mechanism was found to be insufficient to accommodate higher deformation strains. Our results demonstrated that twinning is the dominant deformation mechanism at higher deformation levels. Results also showed that cold rolling in unidirectional and cross rolling modes results in Goss/Brass and Brass dominant textures in deformed samples, respectively. Similar texture components are observed after annealing. Thus, the annealing texture was greatly affected by texture of the deformed parent phase and martensite did not contribute as it showed an athermal reversion during annealing. Results also showed that when the fraction of martensite exceeds a critical point, its grain boundaries impeded the movement of austenite grain boundaries during annealing. As a result, recrystallization incubation time would increase. This caused an incomplete recrystallization of highly deformed samples, which led to a rational drop in the intensity of the texture components. - Highlights: •Thermo-mechanical processing through different cold rolling modes can induce different textures. •Martensite reversion is athermal during annealing. •Higher fraction of deformation-induced martensite can increase the annealing time required for complete recrystallization. •Annealing texture is mainly influenced by the deformation texture of austenite.

  4. Examination of the effect of the annealing cation on higher order structures containing guanine or isoguanine repeats

    Science.gov (United States)

    Pierce, Sarah E.; Wang, Junmei; Jayawickramarajah, Janarthanan; Hamilton, Andrew D.; Brodbelt, Jennifer S.

    2010-01-01

    Isoguanine (2-oxo-6-amino-guanine), a natural but non-standard base, exhibits unique self-association properties compared to its isomer, guanine, and results in formation of different higher order DNA structures. In this work, the higher order structures formed by oligonucleotides containing guanine repeats or isoguanine repeats after annealing in solutions containing various cations are evaluated by electrospray ionization mass spectrometry (ESI-MS) and circular dichroism (CD) spectroscopy. The guanine-containing strand (G9) consistently formed quadruplexes upon annealing, whereas the isoguanine strand (Ig9) formed both pentaplexes and quadruplexes depending on the annealing cation. Quadruplex formation with G9 showed some dependence on the identity of the cation present during annealing with high relative quadruplex formation detected with six of ten cations. Analogous annealing experiments with Ig9 resulted in complex formation with all ten cations, and the majority of the resulting complexes were pentaplexes. CD results indicated most of the original complexes survived the desalting process necessary for ESI-MS analysis. In addition, several complexes, especially the pentaplexes, were found to be capable of cation exchange with ammonium ions. Ab initio calculations were conducted for isoguanine tetrads and pentads coordinated with all ten cations to predict the most energetically stable structures of the complexes in the gas phase. The observed preference of forming quadruplexes versus pentaplexes as a function of the coordinated cation can be interpreted by the calculated reaction energies of both the tetrads and pentads in combination with the distortion energies of tetrads. PMID:19746468

  5. High-temperature annealing of graphite: A molecular dynamics study

    Science.gov (United States)

    Petersen, Andrew; Gillette, Victor

    2018-05-01

    A modified AIREBO potential was developed to simulate the effects of thermal annealing on the structure and physical properties of damaged graphite. AIREBO parameter modifications were made to reproduce Density Functional Theory interstitial results. These changes to the potential resulted in high-temperature annealing of the model, as measured by stored-energy reduction. These results show some resemblance to experimental high-temperature annealing results, and show promise that annealing effects in graphite are accessible with molecular dynamics and reactive potentials.

  6. Effect of annealing on refractive indices of radio-frequency magnetron sputtered waveguiding zinc oxide films on glass

    International Nuclear Information System (INIS)

    Mehan, Navina; Gupta, Vinay; Sreenivas, Kondepudy; Mansingh, Abhai

    2004-01-01

    The effects of annealing and gas composition on the refractive indices of zinc oxide films were studied in light of the structural properties. ZnO films (1 μm) were deposited by rf magnetron sputtering in different oxygen:argon mixtures on glass and annealed at 380 deg. C in air, at different times. Waveguide modes were excited in the films by prism coupling using a He-Ne laser. The estimated values of the extraordinary and ordinary refractive indices of the films, which were close to the corresponding bulk values (n e =2.006, n o =1.990), initially decreased with annealing time and later increased before becoming constant with further annealing. The variation in refractive indices was explained on the basis of contribution from both packing density p and lattice constant c of the films. The initial decrease in refractive indices was attributed to the observed lattice contraction, and the latter increase was explained in terms of the increase in packing density (p) of the films on annealing. A relation is proposed to estimate the refractive indices of films, which have the lattice constant c different from the bulk value

  7. Dopant rearrangement and superconductivity in Bi2Sr2-xLaxCuO6 thin films under annealing

    International Nuclear Information System (INIS)

    Cancellieri, C; Lin, P H; Ariosa, D; Pavuna, D

    2007-01-01

    By combining x-ray diffraction (XRD), x-ray photoemission spectroscopy (XPS) and AC susceptibility measurements we investigate the evolution of structural and superconducting properties of La-doped Bi-2201 thin films grown by pulsed laser deposition (PLD) under different annealing conditions. We find that the main effect of oxygen annealing is to improve the crystal coherence by enabling La cation migration to the Sr sites. This activates the desired hole doping. Short-time Ar annealing removes the interstitial oxygen between the BiO layers, fine adjusting the effective hole doping. The superconducting critical temperature is consequently enhanced. However, longer annealings result in phase separation and segregation of the homologous compound Bi-1201. We attribute this effect to the loss of Bi during the annealing

  8. Effect of dual task activity on reaction time in males and females.

    Science.gov (United States)

    Kaur, Manjinder; Nagpal, Sangeeta; Singh, Harpreet; Suhalka, M L

    2014-01-01

    The present study was designed to compare the auditory and visual reaction time on an Audiovisual Reaction Time Machine with the concomitant use of mobile phones in 52 women and 30 men in the age group of 18-40 years. Males showed significantly (p multitasking, in hand held (24.38% & 18.70% respectively) and hands free modes (36.40% & 18.40% respectively) of the use of cell phone. VRT increased non significantly during multitasking in both the groups. However, the multitasking per se has detrimental effect on the reaction times in both the groups studied. Hence, it should best be avoided in crucial and high attention demanding tasks like driving.

  9. The Effect of Annealing Temperature on Nickel on Reduced Graphene Oxide Catalysts on Urea Electrooxidation

    International Nuclear Information System (INIS)

    Glass, Dean E.; Galvan, Vicente; Prakash, G.K. Surya

    2017-01-01

    Highlights: •Nickel was reduced on graphene oxide and annealed under argon from 300 to 700 °C. •Nickel was oxidized from the removal of oxygen groups on the graphene oxide. •Higher annealed catalysts displayed decreased urea electrooxidation currents. •Micro direct urea/hydrogen peroxide fuel cells were employed for the first time. •Ni/rGO catalysts displayed enhanced fuel cell performance than the bare nickel. -- Abstract: The annealing temperature effects on nickel on reduced graphene oxide (Ni/rGO) catalysts for urea electrooxidation were investigated. Nickel chloride was directly reduced in an aqueous solution of graphene oxide (GO) followed by annealing under argon at 300, 400, 500, 600, and 700 °C, respectively. X-ray Diffraction (XRD) patterns revealed an increase in the crystallite size of the nickel nanoparticles while the Raman spectra displayed an increase in the graphitic disorder of the reduced graphene oxide at higher annealing temperatures due to the removal of oxygen functional groups. The Ni/rGO catalysts annealed at higher temperatures displayed oxidized nickel surface characteristics from the Ni 2p X-ray Photoelectron Spectra (XPS) due to the oxidation of the nickel from the oxygen functional groups in the graphitic lattice. In the half-cell testing, the onset potential of urea electrooxidation decreased while the urea electrooxidation currents decreased as the annealing temperature was increased. The nickel catalyst annealed at 700 °C displayed a 31% decrease in peak power density while the catalyst annealed at 300 °C displayed a 13% increase compared with the unannealed Ni/rGO catalyst in the micro direct urea/hydrogen peroxide fuel cells tests.

  10. Caffeine Reduces Reaction Time and Improves Performance in Simulated-Contest of Taekwondo

    Science.gov (United States)

    Santos, Victor G. F.; Santos, Vander R. F.; Felippe, Leandro J. C.; Almeida, Jose W.; Bertuzzi, Rômulo; Kiss, Maria A. P. D. M.; Lima-Silva, Adriano E.

    2014-01-01

    The aim of this study was to investigate the effects of caffeine on reaction time during a specific taekwondo task and athletic performance during a simulated taekwondo contest. Ten taekwondo athletes ingested either 5 mg·kg−1 body mass caffeine or placebo and performed two combats (spaced apart by 20 min). The reaction-time test (five kicks “Bandal Tchagui”) was performed immediately prior to the first combat and immediately after the first and second combats. Caffeine improved reaction time (from 0.42 ± 0.05 to 0.37 ± 0.07 s) only prior to the first combat (P = 0.004). During the first combat, break times during the first two rounds were shorter in caffeine ingestion, followed by higher plasma lactate concentrations compared with placebo (P = 0.029 and 0.014, respectively). During the second combat, skipping-time was reduced, and relative attack times and attack/skipping ratio was increased following ingestion of caffeine during the first two rounds (all P Caffeine resulted in no change in combat intensity parameters between the first and second combat (all P > 0.05), but combat intensity was decreased following placebo (all P caffeine reduced reaction time in non-fatigued conditions and delayed fatigue during successive taekwondo combats. PMID:24518826

  11. Theoretical study of annealed proton-exchanged Nd $LiNbO_{3}$ channel waveguide lasers with variational method

    CERN Document Server

    De Long Zhang; Yuan Guo Xie; Guilan, Ding; Yuming, Cui; Cai He Chen

    2001-01-01

    The controllable fabrication parameters, including anneal time, initial exchange time, channel width, dependences of TM/sub 00/ mode size, corresponding effective refractive index, effective pump area, and coupling efficiency between pump and laser modes in z-cut annealed proton-exchanged (APE) Nd:LiNbO/sub 3/ channel waveguide lasers were studied by using variational method. The effect of channel width on the surface index increment and the waveguide depth was taken into account. The features of mode size and effective refractive index were summarized, discussed, and compared with previously published experimental results. The effective pump area, which is directly proportional to threshold pump power, increases strongly, slightly, and very slightly with the increase of anneal time, channel width, and initial exchange time, respectively. However, the coupling efficiency, which is directly proportional to slope efficiency, remains constant (around 0.82) no matter what changes made to these parameters. The var...

  12. Investigating the combined effects of heat and lighting on students reaction time in laboratory condition

    Directory of Open Access Journals (Sweden)

    Zohre Mohebian

    2016-12-01

    Full Text Available Introduction: In many workplaces there is exposure to heat and light simultaneously. This study investigated the combined effect of heat and lighting on some cognitive performance, i.e. reaction time. Methodology: the present semi-experimental study was conducted 2015 on 33 healthy students (16 girls and 17 boys with a mean age of 22.1 in the thermal stress chamber. The reaction time parameter by the reaction time measurement device, after exposure to different heat surfaces (dry temperatures 22 °C and 37 °C and lighting surfaces (200, 500 and 1500 lux. Data were analyzed using ANOVA test in SPSS-20. Results: The results showed that the average simple, diagnostic, two-color selective, two-sound selective reaction times and reaction time error increased after combined exposure to heat and lighting and showed a significant difference (P<0.05. The maximum score of reaction time belong to temperature of 37 c° and lighting of 1500 lux, the minimum score of reaction time belong to temperature of 22 °c and lighting of 1500 lux.

  13. High pressure annealing of Europium implanted GaN

    KAUST Repository

    Lorenz, K.; Miranda, S. M. C.; Alves, E.; Roqan, Iman S.; O'Donnell, K. P.; Bokowski, M.

    2012-01-01

    GaN epilayers were implanted with Eu to fluences of 1×10^13 Eu/cm2 and 1×10^15 Eu/cm2. Post-implant thermal annealing was performed in ultra-high nitrogen pressures at temperatures up to 1450 ºC. For the lower fluence effective structural recovery of the crystal was observed for annealing at 1000 ºC while optical activation could be further improved at higher annealing temperatures. The higher fluence samples also reveal good optical activation; however, some residual implantation damage remains even for annealing at 1450 ºC which leads to a reduced incorporation of Eu on substitutional sites, a broadening of the Eu luminescence lines and to a strongly reduced fraction of optically active Eu ions. Possibilities for further optimization of implantation and annealing conditions are discussed.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  14. High pressure annealing of Europium implanted GaN

    KAUST Repository

    Lorenz, K.

    2012-02-09

    GaN epilayers were implanted with Eu to fluences of 1×10^13 Eu/cm2 and 1×10^15 Eu/cm2. Post-implant thermal annealing was performed in ultra-high nitrogen pressures at temperatures up to 1450 ºC. For the lower fluence effective structural recovery of the crystal was observed for annealing at 1000 ºC while optical activation could be further improved at higher annealing temperatures. The higher fluence samples also reveal good optical activation; however, some residual implantation damage remains even for annealing at 1450 ºC which leads to a reduced incorporation of Eu on substitutional sites, a broadening of the Eu luminescence lines and to a strongly reduced fraction of optically active Eu ions. Possibilities for further optimization of implantation and annealing conditions are discussed.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  15. Rapid hardening induced by electric pulse annealing in nanostructured pure aluminum

    DEFF Research Database (Denmark)

    Zeng, Wei; Shen, Yao; Zhang, Ning

    2012-01-01

    Nanostructured pure aluminum was fabricated by heavy cold-rolling and then subjected to recovery annealing either by applying electric pulse annealing or by traditional air furnace annealing. Both annealing treatments resulted in an increase in yield strength due to the occurrence of a “dislocation...... source-limited hardening” mechanism. However, the hardening kinetics was substantially faster for the electric pulse annealed material. Detailed microstructural characterization suggested that the rapid hardening during electric pulse annealing is related to an enhanced rate of recovery of dislocation...

  16. PENJADWALAN FLOWSHOP DENGAN MENGGUNAKAN SIMULATED ANNEALING

    Directory of Open Access Journals (Sweden)

    Muhammad Firdaus

    2015-04-01

    Full Text Available This article apply a machine scheduling technique, named Simulate Annealing (SA to schedule 8 jobs and 5 machines to minimize makespan. A flowshop production flow is chosen as a case study to collect data and attempted to reduce jobs’ makespan. This article also does a sensitivity analysis to explore the implication of the changes of SA parameters as temperature. The results shows that the completion time of the jobs uses SA algoritm can decrease the completion time of the jobs, about 5 hours lower than the existing method. Moreover, total idle time of the machines is also reduced by 2.18 per cent using SA technique. Based on the sensitivity analysis, it indicates that there is a significant relationship between the changes of temperatures and makespan and computation time.

  17. Microstructure Evolution of Electron Beam Physical Vapour Deposited Ni-23.5Cr-2.66Co-1.44Al Superalloy Sheet During Annealing at 600 °C

    Directory of Open Access Journals (Sweden)

    Li Mingwei

    2013-02-01

    Full Text Available Microstructure evolution of electron beam physical vapour deposited (EB-PVD Ni‑23.5Cr‑2.66Co‑1.44Al superalloy sheet during annealing at 600 °C was investigated. The results showed that the as-deposited alloy was composed of only g phase. After annealing at 600 °C, the locations of diffraction peaks were still the same. The (220 diffraction peak of the deposition side increased with annealing time. The sheet on deposited side had a tendency toward forming (220 texture during post-annealing. No obvious texture was observed at as-deposited and annealed sheet at 600 °C in substrate side. The count and size of "voids" decreased with time. The size of grains increased obviously with annealing time. The ultimate tensile strength of EB-PVD Ni-23.5Cr-2.66Co-1.44Al alloy sheet increased from 641 MPa to 829 MPa after annealing at 600 °C for 30 hours.

  18. The effect of annealing atmosphere on the thermoluminescence of synthetic calcite

    International Nuclear Information System (INIS)

    Pagonis, Vasilis

    1998-01-01

    Samples of high purity calcite powder were annealed in air, nitrogen and carbon dioxide atmospheres in the temperature range 300-700 deg. C and in atmospheric pressure. The samples were subsequently irradiated and the effect of the annealing atmosphere and temperature on the thermoluminescence (TL) of the samples was studied. Our results show that both carbonate and oxygen ions play an important part in the TL of calcite annealed in this temperature range. The intensities of the TL signal in the nitrogen and carbon dioxide anneals rise continuously with the annealing temperature. For all annealing temperatures it was found that the carbon dioxide atmosphere caused an increase in the observed TL signal as compared with anneals in an inert nitrogen atmosphere, while the shape of the TL glow curves remained the same. This increase in the observed TL signal is explained via the surface adsorption of carbonate ions. The shape and location of the TL peaks suggest that samples annealed in air exhibit a different type of TL center than samples annealed in nitrogen and carbon dioxide atmospheres. A possible mechanism for the role of oxygen ions involves a surface adsorption process and a subsequent diffusion of oxygen ions in the bulk of the crystal. Annealing of the samples in air at temperatures T>600 deg. C causes a collapse of the TL signal, in agreement with previous studies of calcite powders. No such collapse of the TL signal is observed for the nitrogen and carbon dioxide anneals, suggesting that a different type of TL center and/or recombination center is involved in air anneals. Arrhenius plots for the air anneals yield an activation energy E=0.45±0.05 eV, while the carbon dioxide and nitrogen anneals yield a lower activation energy E=0.28±0.04 eV

  19. Effect of isothermal annealing on degree of crystallinity and mechanical properties of poly(l-lactide-co-glycolide)

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Na; Wang, Liansong [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan, 610041 (China); Graduated School of Chinese Academy of Sciences, Beijing, 100039 (China); Huang, Dongling; Zhang, Tianyao; Zhang, Lifang [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan, 610041 (China); Xiong, Chengdong

    2010-03-15

    We investigated the effect of isothermal annealing on the degree of crystallinity and mechanical properties of a random copolymer-poly(l-lactide-co -glycolide) (PLLGA)-with monomer molar ratios of 85/15 (PLLGA85/15) by performing polarizing optical microscopy, differential scanning calorimetry, and X-ray diffraction, and studying the tensile properties. Isothermal annealing of PLLGA at 130 C was conducted to improve the degree of crystallinity of the copolymer; the maximum degree of crystallinity (44.5%) was achieved after 60 min of annealing. The crystal size/perfection was observed to increase with annealing time. The highest tensile strength of 65.8 MPa was achieved after 80 min of annealing. However, the degree of crystallinity and tensile strength can only reach to certain extent. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. Influence of deposition parameters and annealing on Cu{sub 2}ZnSnS{sub 4} thin films grown by SILAR

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Kinjal; Shah, Dimple V. [Department of Applied Physics, S.V. National Institute of Technology, Surat 395007 (India); Kheraj, Vipul, E-mail: vipulkheraj@gmail.com [Department of Applied Physics, S.V. National Institute of Technology, Surat 395007 (India); Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT 84112 (United States)

    2015-02-15

    Highlights: • Optimisation of Cu{sub 2}ZnSnS{sub 4} (CZTS) thin film deposition using SILAR method. • Study on effects of annealing at different temperature under two different ambients, viz. sulphur and tin sulphide. • Formation of CZTS thin films with good crystalline quality confirmed by XRD and Raman spectra. - Abstract: Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films were deposited on glass substrates using Successive Ionic Layer Adsorption and Reaction (SILAR) technique at the room-temperature. The deposition parameters such as concentration of precursors and number of cycles were optimised for the deposition of uniform CZTS thin films. Effects of annealing at different temperature under two different ambient, viz. sulphur and tin sulphide have also been investigated. The structural and optical properties of the films were studied using X-ray diffraction, scanning electron microscopy, Raman spectroscopy and UV-visible spectra in light with the deposition parameters and annealing conditions. It is observed that a good quality CZTS film can be obtained by SILAR at room temperature followed by annealing at 500 °C in presence of sulphur.

  1. Annealing behavior of high permeability amorphous alloys

    International Nuclear Information System (INIS)

    Rabenberg, L.

    1980-06-01

    Effects of low temperature annealing on the magnetic properties of the amorphous alloy Co 71 4 Fe 4 6 Si 9 6 B 14 4 were investigated. Annealing this alloy below 400 0 C results in magnetic hardening; annealing above 400 0 C but below the crystallization temperature results in magnetic softening. Above the crystallization temperature the alloy hardens drastically and irreversibly. Conventional and high resolution transmission electron microscopy were used to show that the magnetic property changes at low temperatures occur while the alloy is truly amorphous. By imaging the magnetic microstructures, Lorentz electron microscopy has been able to detect the presence of microscopic inhomogeneities in this alloy. The low temperature annealing behavior of this alloy has been explained in terms of atomic pair ordering in the presence of the internal molecular field. Lorentz electron microscopy has been used to confirm this explanation

  2. Isothermal and isochronal annealing methodology to study post-irradiation temperature activated phenomena

    International Nuclear Information System (INIS)

    Chabrerie, C.; Autran, J.L.; Paillet, P.; Flament, O.; Leray, J.L.; Boudenot, J.C.

    1997-01-01

    In this work, the evolution of the oxide trapped charge has been modeled, to predict post-irradiation behavior for arbitrary anneal conditions (i.e., arbitrary temperature-time profiles). Using experimental data obtained from a single isochronal anneal, the method consists of calculating the evolution of the energy distribution of the oxide trapped charge, in the framework of a thermally activated charge detrapping model. This methodology is illustrated in this paper by the prediction of experimental isothermal data from isochronal measurements. The implications of these results to hardness assurance test methods are discussed

  3. Poststimulation time interval-dependent effects of motor cortex anodal tDCS on reaction-time task performance.

    Science.gov (United States)

    Molero-Chamizo, Andrés; Alameda Bailén, José R; Garrido Béjar, Tamara; García López, Macarena; Jaén Rodríguez, Inmaculada; Gutiérrez Lérida, Carolina; Pérez Panal, Silvia; González Ángel, Gloria; Lemus Corchero, Laura; Ruiz Vega, María J; Nitsche, Michael A; Rivera-Urbina, Guadalupe N

    2018-02-01

    Anodal transcranial direct current stimulation (tDCS) induces long-term potentiation-like plasticity, which is associated with long-lasting effects on different cognitive, emotional, and motor performances. Specifically, tDCS applied over the motor cortex is considered to improve reaction time in simple and complex tasks. The timing of tDCS relative to task performance could determine the efficacy of tDCS to modulate performance. The aim of this study was to compare the effects of a single session of anodal tDCS (1.5 mA, for 15 min) applied over the left primary motor cortex (M1) versus sham stimulation on performance of a go/no-go simple reaction-time task carried out at three different time points after tDCS-namely, 0, 30, or 60 min after stimulation. Performance zero min after anodal tDCS was improved during the whole course of the task. Performance 30 min after anodal tDCS was improved only in the last block of the reaction-time task. Performance 60 min after anodal tDCS was not significantly different throughout the entire task. These findings suggest that the motor cortex excitability changes induced by tDCS can improve motor responses, and these effects critically depend on the time interval between stimulation and task performance.

  4. Feasibility of and methodology for thermal annealing an embrittled reactor vessel. Volume 1. Program overview. Final report

    International Nuclear Information System (INIS)

    Mager, T.R.

    1983-01-01

    An EPRI sponsored program was carried out by Westinghouse to determine the extent of fracture toughness recovery as a function of annealing time and temperature for neutron embrittlement sensitive reactor vessel material and to develop an optimal thermal anneal procedure for field applications. Program materials were three weldments fabricated by Combustion Engineering, Inc., from the same heat of A533 Grade B Class 1 plate material and the same heat of MnMoNi weld wire. The only variables were the target copper level and the welding flux which was Linde Grade 80 and Linde 0091. Weldments of 0.22, 0.36, and 0.41 wt % copper were produced. It was concluded from this study that excellent recovery of all properties could be achieved by annealing at 850 0 F (454 0 C) and above for 168 hours. Such an annealing resulted in ductile-brittle transition temperature shift recovery of 80 to 100%, and reirradiation after this annealing indicated that the ductile-brittle transition temperature shift appears to continue at the rate which would have been expected had no anneal been performed. System limitations were identified for both wet and dry annealing methods

  5. Effect of Te atmosphere annealing on the properties of CdZnTe single crystals

    International Nuclear Information System (INIS)

    Yu Pengfei; Jie Wanqi; Wang Tao

    2011-01-01

    Low-resistivity CdZnTe:In (CZT:In) single crystals were annealed under Te atmosphere according to the behaviors of deep-donor Te antisite. The results indicated that the star-like Cd inclusions were completely eliminated after 120 h annealing. Meanwhile, the resistivity is greatly enhanced. The resistivity of the slice annealed after 240 h was achieved as high as 1.8x10 11 Ω cm, five orders of magnitude higher than that of as-grown slice. It suggested that the deep-donor level Te antisites were successfully introduced to pin the Fermi level at the mid band-gap position. The IR transmittances of the slices were also improved, which increased as the annealing time increased. PL measurement revealed that the (D 0 ,X) peak representing high quality of CZT crystal appeared. It can be concluded that the quality of CZT crystals is obviously improved after annealing under Te atmosphere. - Highlights: → High resistivity is due to deep-donor level Te Cd . → The resistivity achieved was as high as 1.8x10 11 Ω cm. → Star-like inclusions are Cd inclusions. → (D 0 ,X) peak represents the improvement of the crystal quality.

  6. High luminescent L-cysteine capped CdTe quantum dots prepared at different reaction times

    Science.gov (United States)

    Kiprotich, Sharon; Onani, Martin O.; Dejene, Francis B.

    2018-04-01

    This paper reports a facile synthesis route of high luminescent L-cysteine capped CdTe quantum dots (QDs). The effect of reaction time on the growth mechanism, optical and physical properties of the CdTe QDs was investigated in order to find the suitability of them towards optical and medical applications. The representative high-resolution transmission microscopy (HRTEM) analysis showed that the as-obtained CdTe QDs appeared as spherical particles with excellent monodispersity. The images exhibited clear lattice fringes which are indicative of good crystallinity. The X-ray diffraction (XRD) pattern displayed polycrystalline nature of the QDs which correspond well to zinc blende phase of bulk CdTe. The crystallite sizes calculated from the Scherrer equation were less than 10 nm for different reaction times which were in close agreement with the values estimated from HRTEM. An increase in reaction time improved crystallinity of the sample as explained by highest peak intensity of the XRD supported by the photoluminescence emission spectra which showed high intensity at a longer growth time. It was observed that for prolonged growth time the emission bands were red shifted from about 517-557 nm for 5-180 min of reaction time due to increase in particle sizes. Ultraviolet and visible analysis displayed well-resolved absorption bands which were red shifted upon an increase in reaction time. There was an inverse relation between the band gap and reaction time. Optical band gap decreases from 3.98 to 2.59 eV with the increase in reaction time from 15 to 180 min.

  7. Dosimetric characteristics of muscovite mineral studied under different annealing conditions

    International Nuclear Information System (INIS)

    Kalita, J M; Wary, G

    2015-01-01

    The annealing effect on the thermoluminescence (TL) characteristics of x-ray irradiated muscovite mineral relevant to dosimetry has been studied. For un-annealed and 473 K annealed samples an isolated TL peak has been observed at around 347 K; however, annealing at 573, 673 and 773 K two composite peaks have been recorded at around 347 and 408 K. Kinetic analysis reveals that there is a trap level at a depth of 0.71 eV, and due to annealing at 573 K (or above), a new trap level generates at 1.23 eV. The dosimetric characteristics, such as dose response, fading and reproducibility, have been studied in detail for all types of samples. The highest linear dose response has been observed from 10 to 2000 mGy in the 773 K annealed sample. Due to generation of the deep trap level, fading is found to reduce significantly just after annealing above 573 K. Reproducibility analysis shows that after 10 cycles of reuse the coefficient of variations in the results for 60, 180 and 1000 mGy dose irradiated 773 K annealed samples are found to be 1.78%, 1.37% and 1.58%, respectively. These analyses demand that after proper annealing muscovite shows important dosimetric features that are essentially required for a thermoluminescence dosimeter (TLD). (paper)

  8. Modeling of irradiation embrittlement and annealing/recovery in pressure vessel steels

    International Nuclear Information System (INIS)

    Lott, R.G.; Freyer, P.D.

    1996-01-01

    The results of reactor pressure vessel (RPV) annealing studies are interpreted in light of the current understanding of radiation embrittlement phenomena in RPV steels. An extensive RPV irradiation embrittlement and annealing database has been compiled and the data reveal that the majority of annealing studies completed to date have employed test reactor irradiated weldments. Although test reactor and power reactor irradiations result in similar embrittlement trends, subtle differences between these two damage states can become important in the interpretation of annealing results. Microstructural studies of irradiated steels suggest that there are several different irradiation-induced microstructural features that contribute to embrittlement. The amount of annealing recovery and the post-anneal re-embrittlement behavior of a steel are determined by the annealing response of these microstructural defects. The active embrittlement mechanisms are determined largely by the irradiation temperature and the material composition. Interpretation and thorough understanding of annealing results require a model that considers the underlying physical mechanisms of embrittlement. This paper presents a framework for the construction of a physically based mechanistic model of irradiation embrittlement and annealing behavior

  9. Cu-Al alloy formation by thermal annealing of Cu/Al multilayer films deposited by cyclic metal organic chemical vapor deposition

    Science.gov (United States)

    Moon, Hock Key; Yoon, Jaehong; Kim, Hyungjun; Lee, Nae-Eung

    2013-05-01

    One of the most important issues in future Cu-based interconnects is to suppress the resistivity increase in the Cu interconnect line while decreasing the line width below 30 nm. For the purpose of mitigating the resistivity increase in the nanoscale Cu line, alloying Cu with traces of other elements is investigated. The formation of a Cu alloy layer using chemical vapor deposition or electroplating has been rarely studied because of the difficulty in forming Cu alloys with elements such as Al. In this work, Cu-Al alloy films were successfully formed after thermal annealing of Cu/Al multilayers deposited by cyclic metal-organic chemical vapor deposition (C-MOCVD). After the C-MOCVD of Cu/Al multilayers without gas phase reaction between the Cu and Al precursors in the reactor, thermal annealing was used to form Cu-Al alloy films with a small Al content fraction. The resistivity of the alloy films was dependent on the Al precursor delivery time and was lower than that of the aluminum-free Cu film. No presence of intermetallic compounds were detected in the alloy films by X-ray diffraction measurements and transmission electron spectroscopy.

  10. Chemical and morphological modifications of single layer graphene submitted to annealing in water vapor

    Science.gov (United States)

    Rolim, Guilherme Koszeniewski; Corrêa, Silma Alberton; Galves, Lauren Aranha; Lopes, João Marcelo J.; Soares, Gabriel Vieira; Radtke, Cláudio

    2018-01-01

    Modifications of single layer graphene transferred to SiO2/Si substrates resulting from annealing in water vapor were investigated. Near edge X-ray absorption fine structure spectroscopy evidenced graphene puckering between 400 and 500 °C. Synchrotron radiation based X-ray photoelectron spectroscopy showed variation of sp2 and sp3C bonding configurations specially in this same temperature range. Moreover, oxygen related functionalities are formed as a result of water vapor annealing. Based on these results and complementary Raman and nuclear reaction analysis, one distinguishes three different regimes of water interaction with graphene concerning modifications of the graphene layer. In the low temperature range (200-400 °C), no prominent modification of graphene itself is observed. At higher temperatures (400-500 °C), to accommodate newly formed oxygen functionalities, the flat and continuous sp2 bonding network of graphene is disrupted, giving rise to a puckered layer. For 600 °C and above, shrinking of graphene domains and a higher doping level take place.

  11. Continuous performance task in ADHD: Is reaction time variability a key measure?

    Science.gov (United States)

    Levy, Florence; Pipingas, Andrew; Harris, Elizabeth V; Farrow, Maree; Silberstein, Richard B

    2018-01-01

    To compare the use of the Continuous Performance Task (CPT) reaction time variability (intraindividual variability or standard deviation of reaction time), as a measure of vigilance in attention-deficit hyperactivity disorder (ADHD), and stimulant medication response, utilizing a simple CPT X-task vs an A-X-task. Comparative analyses of two separate X-task vs A-X-task data sets, and subgroup analyses of performance on and off medication were conducted. The CPT X-task reaction time variability had a direct relationship to ADHD clinician severity ratings, unlike the CPT A-X-task. Variability in X-task performance was reduced by medication compared with the children's unmedicated performance, but this effect did not reach significance. When the coefficient of variation was applied, severity measures and medication response were significant for the X-task, but not for the A-X-task. The CPT-X-task is a useful clinical screening test for ADHD and medication response. In particular, reaction time variability is related to default mode interference. The A-X-task is less useful in this regard.

  12. Improved behavior of cooper-amine complexes during thermal annealing for conductive thin film synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Ayag, Kevin Ray; Panama, Gustavo; Paul, Shrabani; Kim, Hong Doo [Dept. of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin (Korea, Republic of)

    2017-02-15

    Previous studies successfully produced conductive thin films from organo-metallic-compounds-based inks. Some inks like those made from copper salt and amines, however, tend to move during thermal annealing and, thus, affect the conductive pattern on the substrate. In this study, conductive inks were synthesized by forming complexes of copper with amines and/or blended amines. To build-up an organo-metallic framework and preserve the pattern throughout the annealing period, diamine was added to the complex in different proportions. The prepared inks were coated on glass substrate and were annealed on a hot plate at 170°C under the gaseous mixture of formic acid and alcohol for 5 min. The metallic film was observed to retain the original pattern of the ink during and after annealing. Adhesion on the substrate was also improved. Inks with blended amines produced films with lower resistivities. The lowest electrical resistivity recorded was 4.99 μΩ cm, three times that of bulk copper.

  13. Observation of glassy state relaxation during annealing of frozen sugar solutions by X-ray computed tomography.

    Science.gov (United States)

    Nakagawa, Kyuya; Tamiya, Shinri; Do, Gabsoo; Kono, Shinji; Ochiai, Takaaki

    2018-06-01

    Glassy phase formation in a frozen product determines various properties of the freeze-dried products. When an aqueous solution is subjected to freezing, a glassy phase forms as a consequence of freeze-concentration. During post-freezing annealing, the relaxation of the glassy phase and the ripening of ice crystals (i.e. Ostwald ripening) spontaneously occur, where the kinetics are controlled by the annealing and glass transition temperatures. This study was motivated to observe the progress of glassy state relaxation separate from ice coarsening during annealing. X-ray computed tomography (CT) was used to observe a frozen and post-freezing annealed solutions by using monochromatized X-ray from the synchrotron radiation. CT images were successfully obtained, and the frozen matrix were analyzed based on the gray level values that were equivalent to the linear X-ray attenuation coefficients of the observed matters. The CT images obtained from rapidly frozen sucrose and dextrin solutions with different concentrations gave clear linear relationships between the linear X-ray attenuation coefficients values and the solute concentrations. It was confirmed that the glassy state relaxation progressed as increasing annealing time, and this trend was larger in the order of the glass transition temperature of the maximally freeze-concentrated phase. The sucrose-water system required nearly 20 h of annealing time at -5 °C for the completion of the glassy phase relaxation, whereas dextrin-water systems required much longer periods because of their higher glass transition temperatures. The trends of ice coarsening, however, did not perfectly correspond to the trends of the relaxation, suggesting that the glassy phase relaxation and Ostwald ripening would jointly control the ice crystal growth/ripening kinetics, and the dominant mechanism differed by the annealing stage. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Time-dependent--S-matrix Hartree-Fock theory of complex reactions

    International Nuclear Information System (INIS)

    Griffin, J.J.; Lichtner, P.C.; Dworzecka, M.

    1980-01-01

    Some limitations of the conventional time-dependent Hartree-Fock method for describing complex reactions are noted, and one particular ubiquitous defect is discussed in detail: the post-breakup spurious cross channel correlations which arise whenever several asymptotic reaction channels must be simultaneously described by a single determinant. A reformulated time-dependent--S-matrix Hartree-Fock theory is proposed, which obviates this difficulty. Axiomatic requirements minimal to assure that the time-dependent--S-matrix Hartree-Fock theory represents an unambiguous and physically interpretable asymptotic reaction theory are utilized to prescribe conditions upon the definition of acceptable asymptotic channels. That definition, in turn, defines the physical range of the time-dependent--S-matrix Hartree-Fock theory to encompass the collisions of mathematically well-defined ''time-dependent Hartree-Fock droplets.'' The physical properties of these objects then circumscribe the content of the Hartree-Fock single determinantal description. If their periodic vibrations occur for continuous ranges of energy then the resulting ''classical'' time-dependent Hartree-Fock droplets are seen to be intrinsically dissipative, and the single determinantal description of their collisions reduces to a ''trajectory'' theory which can describe the masses and relative motions of the fragments but can provide no information about specific asymptotic excited states beyond their constants of motion, or the average properties of the limit, if it exists, of their equilibrization process. If, on the other hand, the periodic vibrations of the time-dependent Hartree-Fock droplets are discrete in energy, then the time-dependent--S-matrix Hartree-Fock theory can describe asymptotically the time-average properties of the whole spectrum of such periodic vibrations

  15. Numerical and experimental simulation of mechanical and microstructural transformations in Batch annealing steels

    International Nuclear Information System (INIS)

    Monsalve, A.; Artigas, A.; Celentano, D.; Melendez, F.

    2004-01-01

    The heating and cooling curves during batch annealing process of low carbon steel have been modeled using the finite element technique. This has allowed to predict the transient thermal profile for every point of the annealed coils, particularly for the hottest and coldest ones. Through experimental measurements, the results have been adequately validated since a good agreement has been found between experimental values and those predicted by the model. Moreover, an Avrami recrystallization model. Moreover, and Avrami recrystallization model has been coupled to this thermal balance computation. Interrupted annealing experiments have been made by measuring the recrystallized fraction on the extreme points of the coil foe different times. These data gave the possibility to validate the developed recrystallization model through a reasonably good numerical-experimental fittings. (Author) 6 refs

  16. Thermal annealing of an embrittled reactor pressure vessel

    International Nuclear Information System (INIS)

    Mager, T.R.; Dragunov, Y.G.; Leitz, C.

    1998-01-01

    As a result of the popularity of the Agencies report 'Neutron Irradiation Embrittlement of Reactor Pressure Vessel Steels' of 1975, it was decided that another report on this broad subject would be of use. In this report, background and contemporary views on specially identified areas of the subject are considered as self-contained chapters, written by experts. Chapter 11 deals with thermal annealing of an embrittled reactor pressure vessel. Anneal procedures for vessels from both the US and the former USSR are mentioned schematically, wet anneals at lower temperature and dry anneals above RPV design temperatures are investigated. It is shown that heat treatment is a means of recovering mechanical properties which were degraded by neutron radiation exposure, thus assuring reactor pressure vessel compliance with regulatory requirements

  17. Solvent vapor annealing of an insoluble molecular semiconductor

    KAUST Repository

    Amassian, Aram

    2010-01-01

    Solvent vapor annealing has been proposed as a low-cost, highly versatile, and room-temperature alternative to thermal annealing of organic semiconductors and devices. In this article, we investigate the solvent vapor annealing process of a model insoluble molecular semiconductor thin film - pentacene on SiO 2 exposed to acetone vapor - using a combination of optical reflectance and two-dimensional grazing incidence X-ray diffraction measurements performed in situ, during processing. These measurements provide valuable and new insight into the solvent vapor annealing process; they demonstrate that solvent molecules interact mainly with the surface of the film to induce a solid-solid transition without noticeable swelling, dissolving or melting of the molecular material. © 2010 The Royal Society of Chemistry.

  18. Enhancement of electron transfer from CdSe core/shell quantum dots to TiO2 films by thermal annealing

    International Nuclear Information System (INIS)

    Shao, Cong; Meng, Xiangdong; Jing, Pengtao; Sun, Mingye; Zhao, Jialong; Li, Haibo

    2013-01-01

    We demonstrated the enhancement of electron transfer from CdSe/ZnS core/shell quantum dots (QDs) to TiO 2 films via thermal annealing by means of steady-state and time-resolved photoluminescence (PL) spectroscopy. The significant decrease in PL intensities and lifetimes of the QDs on TiO 2 films was clearly observed after thermal annealing at temperature ranging from 100 °C to 300 °C. The obtained rates of electron transfer from CdSe core/shell QDs with red, yellow, and green emissions to TiO 2 films were significantly enhanced from several times to an order of magnitude (from ∼10 7 s −1 to ∼10 8 s −1 ). The improvement in efficiencies of electron transfer in the TiO 2 /CdSe QD systems was also confirmed. The enhancement could be considered to result from the thermal annealing reduced distance between CdSe QDs and TiO 2 films. The experimental results revealed that thermal annealing would play an important role on improving performances of QD based optoelectronic devices. -- Highlights: • Annealing-induced enhancement of electron transfer from CdSe to TiO 2 is reported. • CdSe QDs on TiO 2 and SiO 2 films are annealed at various temperatures. • Steady-state and time-resolved PL spectroscopy of CdSe QDs is studied. • The enhancement is related to the reduced distance between CdSe QDs and TiO 2

  19. Post-annealing effects on shallow-junction characteristics caused by 20 keV BGe molecular ion implantation

    International Nuclear Information System (INIS)

    Liang, J.H.; Sang, Y.J.; Wang, C.-H.; Wang, T.W.; Hsu, J.Y.; Niu, H.; Tseng, M.S.

    2005-01-01

    This study examines the post-annealing-dependent behaviors of the shallow junction produced by implanting 10 15 cm -2 20 keV BGe ions into n-type silicon specimens. Post-annealing treatments consisted of one- and two-step annealing including both furnace annealing (FA) and rapid thermal annealing (RTA). Comparison of the one-step FA at 550 deg. C and the one-step RTA at 1050 deg. C revealed that boron depth profiles were slightly diffused in the former but exhibited considerable transient-enhanced diffusion (TED) in the latter. However, both the one-step FA- and RTA-annealed germanium depth profiles barely diffused, while the latter diffusing slightly deeper than the former. The optimum value of junction depth (x j ) times sheet resistance (R s ) was obtained with one-step FA at 550 deg. C for 1 h. The two-step annealing (FA at 550 deg. C and RTA at 1050 deg. C) results showed that the RTA-induced TED in the boron depth profiles could be effectively retarded only when FA took place for more than 3 h. Again, germanium depth profiles are also barely diffused while the corresponding TEDs were larger than those in one-step FA but smaller than those in one-step RTA. Furthermore, the two-step annealing of FA at 550 deg. C for 3 h followed by RTA at 1050 deg. C for 30 s is suggested when attempting to obtain an optimum value of x j R s

  20. Simulation of biochemical reactions with time-dependent rates by the rejection-based algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Thanh, Vo Hong, E-mail: vo@cosbi.eu [The Microsoft Research - University of Trento Centre for Computational and Systems Biology, Piazza Manifattura 1, Rovereto 38068 (Italy); Priami, Corrado, E-mail: priami@cosbi.eu [The Microsoft Research - University of Trento Centre for Computational and Systems Biology, Piazza Manifattura 1, Rovereto 38068 (Italy); Department of Mathematics, University of Trento, Trento (Italy)

    2015-08-07

    We address the problem of simulating biochemical reaction networks with time-dependent rates and propose a new algorithm based on our rejection-based stochastic simulation algorithm (RSSA) [Thanh et al., J. Chem. Phys. 141(13), 134116 (2014)]. The computation for selecting next reaction firings by our time-dependent RSSA (tRSSA) is computationally efficient. Furthermore, the generated trajectory is exact by exploiting the rejection-based mechanism. We benchmark tRSSA on different biological systems with varying forms of reaction rates to demonstrate its applicability and efficiency. We reveal that for nontrivial cases, the selection of reaction firings in existing algorithms introduces approximations because the integration of reaction rates is very computationally demanding and simplifying assumptions are introduced. The selection of the next reaction firing by our approach is easier while preserving the exactness.

  1. Annealing-induced Fe oxide nanostructures on GaAs

    OpenAIRE

    Lu, Y X; Ahmad, E; Xu, Y B; Thompson, S M

    2005-01-01

    We report the evolution of Fe oxide nanostructures on GaAs(100) upon pre- and post-growth annealing conditions. GaAs nanoscale pyramids were formed on the GaAs surface due to wet etching and thermal annealing. An 8.0-nm epitaxial Fe film was grown, oxidized, and annealed using a gradient temperature method. During the process the nanostripes were formed, and the evolution has been demonstrated using transmission and reflection high energy electron diffraction, and scanning electron microscopy...

  2. Hydrogen Annealing Of Single-Crystal Superalloys

    Science.gov (United States)

    Smialek, James L.; Schaeffer, John C.; Murphy, Wendy

    1995-01-01

    Annealing at temperature equal to or greater than 2,200 degrees F in atmosphere of hydrogen found to increase ability of single-crystal superalloys to resist oxidation when subsequently exposed to oxidizing atmospheres at temperatures almost as high. Supperalloys in question are principal constituents of hot-stage airfoils (blades) in aircraft and ground-based turbine engines; also used in other high-temperature applications like chemical-processing plants, coal-gasification plants, petrochemical refineries, and boilers. Hydrogen anneal provides resistance to oxidation without decreasing fatigue strength and without need for coating or reactive sulfur-gettering constituents. In comparison with coating, hydrogen annealing costs less. Benefits extend to stainless steels, nickel/chromium, and nickel-base alloys, subject to same scale-adhesion and oxidation-resistance considerations, except that scale is chromia instead of alumina.

  3. MgO magnetic tunnel junctions of enduring F-type upon annealing

    International Nuclear Information System (INIS)

    Schleicher, F; Halisdemir, U; Urbain, E; Gallart, M; Boukari, S; Beaurepaire, E; Gilliot, P; Bowen, M; Lacour, D; Montaigne, F; Hehn, M

    2015-01-01

    The authors performed magnetotransport experiments to determine whether annealing alters the oxygen vacancy-mediated tunnelling potential landscape of the central portion of a MgO ultrathin film within sputtered CoFeB/MgO/CoFeB magnetic tunnel junctions. Using the Î rel method reveals a temperature-dependent tunnelling barrier height for a non-annealed barrier that arises from single oxygen vacancies (F centres) and is qualitatively identical to that found for its partly and fully annealed counterparts. Thus these MTJs with F centres remain of F-type upon annealing. This explicitly confirms that the large tunnel-magnetoresistance (TMR) increase upon annealing results mainly from structural modifications of MgO and CoFeB and not from vacancy pairing within the barrier. Photoluminescence spectra performed on both annealed and non-annealed thin MgO films grown on CoFeB electrodes support this conclusion. This work should promote renewed scrutiny over the precise impact of annealing on tunnelling magnetotransport across MgO. (paper)

  4. Influence of oxygen annealing on the dielectric properties of SrBi{sub 2}(V{sub 0.1}Nb{sub 0.9}){sub 2}O{sub 9} ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Y.; Forbess, M.; Seraji, S.; Limmer, S.; Chou, T.; Cao, G.Z. [University of Washington, Materials Science and Engineering, Seattle, WA (United States)]. E-mail: gzcao@u.washington.edu

    2001-09-07

    The influences of O{sub 2} and N{sub 2} annealing on the dielectric properties of SrBi{sub 2}(V{sub 0.1}Nb{sub 0.9}){sub 2}O{sub 9} (SBVN) ferroelectrics were studied. Ceramic samples were prepared by reaction sintering a powder mixture of constituent oxides at 950 deg. C for 2 h in air. Some samples were also subsequently annealed at 800 deg. C for 3 h in O{sub 2} or N{sub 2}. With O{sub 2} annealing, the Curie point of the SBVN ferroelectrics changed from {approx}433 to {approx}438 deg. C and the peak dielectric constant increased from {approx}760 to {approx}1010 (at 100 kHz). However, no change in the Curie point was found with N{sub 2} annealing. Furthermore, O{sub 2} annealing was found to reduce significantly both the dielectric constant and loss tangent of the SBVN ferroelectrics at frequencies below 1000 Hz. XRD results revealed a small reduction in the lattice constants with O{sub 2} annealing, but no appreciable change with N{sub 2} annealing. In addition, no detectable change in the microstructure of the SBVN samples was found with annealing. These results imply that some V{sup 4+} ions, which are compensated by the formation of oxygen vacancies, existed in the SBVN ferroelectrics prior to O{sub 2} annealing. V{sup 4+} ions were oxidized to V{sup 5+} with O{sub 2} annealing, which resulted in improved dielectric properties. (author)

  5. Effect of electric-spark alloying and subsequent annealing on the thermal stability of metallic structural materials

    International Nuclear Information System (INIS)

    Vdovin, S.F.; Reshetnikov, S.M.

    2000-01-01

    The effect of annealing on resistive properties of electric-spark coatings on the carbon steels is studied. The steels 10 and 20 samples with electric spark coatings of various compositions and control ones without annealing and coating are chosen for the study. The steels cr27 and 12cr18ni10ti, the nichrome (cr20ni80) alloy, aluminium as well as compositions of these materials: aluminium + cr27 and aluminium + nichrome were used as coating materials. It is shown that aluminium coatings increase the steel 10 heat resistance more them by 4 times, the aluminium + nichrome coatings - more than by 6 times and aluminium + cr27 coatings - more than by 6 times. In contrast to the electric-spark coating of the carbon steel surface by chromium-nickel alloys, the composition aluminium-containing coatings with annealing in vacuum provide for reliability of long-term protection of these steels from air oxidation with the temperature above the aluminium melting [ru

  6. Vessel annealing. Will it become a routine procedure?

    International Nuclear Information System (INIS)

    Davies, M.

    1995-01-01

    The effect of neutron radiation on the reactor pressure vessel and the influence of annealing performed to eliminate this effect are explained. Some practical examples are given. A simple heat treatment at 450 degC for 168 h is sufficient to eliminate a major fraction of the radiation effect in the displacement of the transition temperature from the brittle state to the tough state. Some observations indicate that at this temperature, excessive energy recovery takes place at the upper toughness limit in the Charpy diagram. The annealing furnace manufactured by the SKODA company is described. The furnace consists of heating elements in 13 zones and 5 heating sections. The maximum power of each element is 75 kW, the total power of the furnace is 975 kW. The annealing procedure and its results are briefly outlined for the reactor pressure vessel at unit 2 of the Jaslovske Bohunice NPP. Reactor pressure vessel annealing is proposed for the Marble Hill NPP which has been shut down. Preparatory activities for annealing are also under way at the Loviisa NPP. (J.B.)

  7. MoO3 Thickness, Thermal Annealing and Solvent Annealing Effects on Inverted and Direct Polymer Photovoltaic Solar Cells

    Directory of Open Access Journals (Sweden)

    Guillaume Wantz

    2012-11-01

    Full Text Available Several parameters of the fabrication process of inverted polymer bulk heterojunction solar cells based on titanium oxide as an electron selective layer and molybdenum oxide as a hole selective layer were tested in order to achieve efficient organic photovoltaic solar cells. Thermal annealing treatment is a common process to achieve optimum morphology, but it proved to be damageable for the performance of this kind of inverted solar cells. We demonstrate using Auger analysis combined with argon etching that diffusion of species occurs from the MoO3/Ag top layers into the active layer upon thermal annealing. In order to achieve efficient devices, the morphology of the bulk heterojunction was then manipulated using the solvent annealing technique as an alternative to thermal annealing. The influence of the MoO3 thickness was studied on inverted, as well as direct, structure. It appeared that only 1 nm-thick MoO3 is enough to exhibit highly efficient devices (PCE = 3.8% and that increasing the thickness up to 15 nm does not change the device performance. 

  8. Atomic scale simulations of arsenic ion implantation and annealing in silicon

    International Nuclear Information System (INIS)

    Caturla, M.J.; Diaz de la Rubia, T.; Jaraiz, M.

    1995-01-01

    We present results of multiple-time-scale simulations of 5, 10 and 15 keV low temperature ion implantation of arsenic on silicon (100), followed by high temperature anneals. The simulations start with a molecular dynamics (MD) calculation of the primary state of damage after 10ps. The results are then coupled to a kinetic Monte Carlo (MC) simulation of bulk defect diffusion and clustering. Dose accumulation is achieved considering that at low temperatures the damage produced in the lattice is stable. After the desired dose is accumulated, the system is annealed at 800 degrees C for several seconds. The results provide information on the evolution for the damage microstructure over macroscopic length and time scales and affords direct comparison to experimental results. We discuss the database of inputs to the MC model and how it affects the diffusion process

  9. MEDICAL STAFF SCHEDULING USING SIMULATED ANNEALING

    Directory of Open Access Journals (Sweden)

    Ladislav Rosocha

    2015-07-01

    Full Text Available Purpose: The efficiency of medical staff is a fundamental feature of healthcare facilities quality. Therefore the better implementation of their preferences into the scheduling problem might not only rise the work-life balance of doctors and nurses, but also may result into better patient care. This paper focuses on optimization of medical staff preferences considering the scheduling problem.Methodology/Approach: We propose a medical staff scheduling algorithm based on simulated annealing, a well-known method from statistical thermodynamics. We define hard constraints, which are linked to legal and working regulations, and minimize the violations of soft constraints, which are related to the quality of work, psychic, and work-life balance of staff.Findings: On a sample of 60 physicians and nurses from gynecology department we generated monthly schedules and optimized their preferences in terms of soft constraints. Our results indicate that the final value of objective function optimized by proposed algorithm is more than 18-times better in violations of soft constraints than initially generated random schedule that satisfied hard constraints.Research Limitation/implication: Even though the global optimality of final outcome is not guaranteed, desirable solutionwas obtained in reasonable time. Originality/Value of paper: We show that designed algorithm is able to successfully generate schedules regarding hard and soft constraints. Moreover, presented method is significantly faster than standard schedule generation and is able to effectively reschedule due to the local neighborhood search characteristics of simulated annealing.

  10. Post-growth annealing of Bridgman-grown CdZnTe and CdMnTe crystals for room-temperature nuclear radiation detectors

    International Nuclear Information System (INIS)

    Egarievwe, Stephen U.; Yang, Ge; Egarievwe, Alexander A.; Okwechime, Ifechukwude O.; Gray, Justin; Hales, Zaveon M.; Hossain, Anwar; Camarda, Giuseppe S.; Bolotnikov, Aleksey E.; James, Ralph B.

    2015-01-01

    Bridgman-grown cadmium zinc telluride (CdZnTe or CZT) and cadmium manganese telluride (CdMnTe or CMT) crystals often have Te inclusions that limit their performances as X-ray- and gamma-ray-detectors. We present here the results of post-growth thermal annealing aimed at reducing and eliminating Te inclusions in them. In a 2D analysis, we observed that the sizes of the Te inclusions declined to 92% during a 60-h annealing of CZT at 510 °C under Cd vapor. Further, tellurium inclusions were eliminated completely in CMT samples annealed at 570 °C in Cd vapor for 26 h, whilst their electrical resistivity fell by an order of 10 2 . During the temperature-gradient annealing of CMT at 730 °C and an 18 °C/cm temperature gradient for 18 h in a vacuum of 10 −5 mbar, we observed the diffusion of Te from the sample, so causing a reduction in size of the Te inclusions. For CZT samples annealed at 700 °C in a 10 °C/cm temperature gradient, we observed the migration of Te inclusions from a low-temperature region to a high one at 0.022 μm/s. During the temperature-gradient annealing of CZT in a vacuum of 10 −5 mbar at 570 °C and 30 °C/cm for 18 h, some Te inclusions moved toward the high-temperature side of the wafer, while other inclusions of the same size, i.e., 10 µm in diameter, remained in the same position. These results show that the migration, diffusion, and reaction of Te with Cd in the matrix of CZT- and CMT-wafers are complex phenomena that depend on the conditions in local regions, such as composition and structure, as well as on the annealing conditions

  11. Study on thermal annealing of cadmium zinc telluride (CZT) crystals

    International Nuclear Information System (INIS)

    Yang, G.; Bolotnikov, A.E.; Fochuk, P.M.; Camarda, G.S.; Cui, Y.; Hossain, A.; Kim, K.; Horace, J.; McCall, B.; Gul, R.; Xu, L.; Kopach, O.V.; James, R.B.

    2010-01-01

    Cadmium Zinc Telluride (CZT) has attracted increasing interest with its promising potential as a room-temperature nuclear-radiation-detector material. However, different defects in CZT crystals, especially Te inclusions and dislocations, can degrade the performance of CZT detectors. Post-growth annealing is a good approach potentially to eliminate the deleterious influence of these defects. At Brookhaven National Laboratory (BNL), we built up different facilities for investigating post-growth annealing of CZT. Here, we report our latest experimental results. Cd-vapor annealing reduces the density of Te inclusions, while large temperature gradient promotes the migration of small-size Te inclusions. Simultaneously, the annealing lowers the density of dislocations. However, only-Cd-vapor annealing decreases the resistivity, possibly reflecting the introduction of extra Cd in the lattice. Subsequent Te-vapor annealing is needed to ensure the recovery of the resistivity after removing the Te inclusions.

  12. Stepwise kinetic equilibrium models of quantitative polymerase chain reaction

    Directory of Open Access Journals (Sweden)

    Cobbs Gary

    2012-08-01

    Full Text Available Abstract Background Numerous models for use in interpreting quantitative PCR (qPCR data are present in recent literature. The most commonly used models assume the amplification in qPCR is exponential and fit an exponential model with a constant rate of increase to a select part of the curve. Kinetic theory may be used to model the annealing phase and does not assume constant efficiency of amplification. Mechanistic models describing the annealing phase with kinetic theory offer the most potential for accurate interpretation of qPCR data. Even so, they have not been thoroughly investigated and are rarely used for interpretation of qPCR data. New results for kinetic modeling of qPCR are presented. Results Two models are presented in which the efficiency of amplification is based on equilibrium solutions for the annealing phase of the qPCR process. Model 1 assumes annealing of complementary targets strands and annealing of target and primers are both reversible reactions and reach a dynamic equilibrium. Model 2 assumes all annealing reactions are nonreversible and equilibrium is static. Both models include the effect of primer concentration during the annealing phase. Analytic formulae are given for the equilibrium values of all single and double stranded molecules at the end of the annealing step. The equilibrium values are then used in a stepwise method to describe the whole qPCR process. Rate constants of kinetic models are the same for solutions that are identical except for possibly having different initial target concentrations. Analysis of qPCR curves from such solutions are thus analyzed by simultaneous non-linear curve fitting with the same rate constant values applying to all curves and each curve having a unique value for initial target concentration. The models were fit to two data sets for which the true initial target concentrations are known. Both models give better fit to observed qPCR data than other kinetic models present in the

  13. Stepwise kinetic equilibrium models of quantitative polymerase chain reaction.

    Science.gov (United States)

    Cobbs, Gary

    2012-08-16

    Numerous models for use in interpreting quantitative PCR (qPCR) data are present in recent literature. The most commonly used models assume the amplification in qPCR is exponential and fit an exponential model with a constant rate of increase to a select part of the curve. Kinetic theory may be used to model the annealing phase and does not assume constant efficiency of amplification. Mechanistic models describing the annealing phase with kinetic theory offer the most potential for accurate interpretation of qPCR data. Even so, they have not been thoroughly investigated and are rarely used for interpretation of qPCR data. New results for kinetic modeling of qPCR are presented. Two models are presented in which the efficiency of amplification is based on equilibrium solutions for the annealing phase of the qPCR process. Model 1 assumes annealing of complementary targets strands and annealing of target and primers are both reversible reactions and reach a dynamic equilibrium. Model 2 assumes all annealing reactions are nonreversible and equilibrium is static. Both models include the effect of primer concentration during the annealing phase. Analytic formulae are given for the equilibrium values of all single and double stranded molecules at the end of the annealing step. The equilibrium values are then used in a stepwise method to describe the whole qPCR process. Rate constants of kinetic models are the same for solutions that are identical except for possibly having different initial target concentrations. Analysis of qPCR curves from such solutions are thus analyzed by simultaneous non-linear curve fitting with the same rate constant values applying to all curves and each curve having a unique value for initial target concentration. The models were fit to two data sets for which the true initial target concentrations are known. Both models give better fit to observed qPCR data than other kinetic models present in the literature. They also give better estimates of

  14. Interface Structure and Elements Diffusion of As-Cast and Annealed Ductile Iron/Stainless Steel Bimetal Castings

    Directory of Open Access Journals (Sweden)

    M. Ramadan

    2018-04-01

    Full Text Available Bimetal casting is considered to a promising technique for the production of high performance function materials. Heat treatment process for bimetal castings became an essential tool for improving interface structure and metallurgical diffusion bond. Molten iron alloy with carbon equivalent of 4.40 is poured into sand mold cavities containing solid 304 stainless steel strips insert. Specimens are heated to 7200C in an electrical heating furnace and holded at 720 0C for 60min and 180min. For as-cast specimens, a good coherent interface structure of ductile cast iron/304 stainless bimetal with four layers interfacial microstructure are obtained. Low temperature annealing at 720oC has a significat effect on the interface layers structure, where, three layers of interface structure are obtained after 180min annealing time because of the complete dissolving of thin layer of ferrite and multi carbides (Layer 2. Low temperature annealing shows a significant effect on the diffusion of C and otherwise shows slightly effect on the diffusion of Cr and Ni. Plearlite phase of Layer 3 is trsformed to spheroidal shape instead of lamallar shape in as-cast bimetals by low tempeature annealing at 720oC. The percent of the performed spheroidal cementit increases by increasing anneaaling time. Hardness of interface layers is changed by low temperauture annealing due to the significant carbon deffussion.

  15. Irradiation embrittlement and optimisation of annealing

    International Nuclear Information System (INIS)

    1993-01-01

    This conference is composed of 30 papers grouped in 6 sessions related to the following themes: neutron irradiation effects in pressure vessel steels and weldments used in PWR, WWER and BWR nuclear plants; results from surveillance programmes (irradiation induced damage and annealing processes); studies on the influence of variations in irradiation conditions and mechanisms, and modelling; mitigation of irradiation effects, especially through thermal annealing; mechanical test procedures and specimen size effects

  16. Irradiation embrittlement and optimisation of annealing

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    This conference is composed of 30 papers grouped in 6 sessions related to the following themes: neutron irradiation effects in pressure vessel steels and weldments used in PWR, WWER and BWR nuclear plants; results from surveillance programmes (irradiation induced damage and annealing processes); studies on the influence of variations in irradiation conditions and mechanisms, and modelling; mitigation of irradiation effects, especially through thermal annealing; mechanical test procedures and specimen size effects.

  17. Effect of Colour of Object on Simple Visual Reaction Time in Normal Subjects

    Directory of Open Access Journals (Sweden)

    Sunita B. Kalyanshetti

    2014-01-01

    Full Text Available The measure of simple reaction time has been used to evaluate the processing speed of CNS and the co-ordination between the sensory and motor systems. As the reaction time is influenced by different factors; the impact of colour of objects in modulating the reaction time has been investigated in this study. 200 healthy volunteers (female gender 100 and male gender100 of age group 18-25 yrs were included as subjects. The subjects were presented with two visual stimuli viz; red and green light by using an electronic response analyzer. Paired‘t’ test for comparison of visual reaction time for red and green colour in male gender shows p value<0.05 whereas in female gender shows p<0.001. It was observed that response latency for red colour was lesser than that of green colour which can be explained on the basis of trichromatic theory.

  18. Iron phthalocyanine on Cu(111): Coverage-dependent assembly and symmetry breaking, temperature-induced homocoupling, and modification of the adsorbate-surface interaction by annealing.

    Science.gov (United States)

    Snezhkova, Olesia; Bischoff, Felix; He, Yuanqin; Wiengarten, Alissa; Chaudhary, Shilpi; Johansson, Niclas; Schulte, Karina; Knudsen, Jan; Barth, Johannes V; Seufert, Knud; Auwärter, Willi; Schnadt, Joachim

    2016-03-07

    We have examined the geometric and electronic structures of iron phthalocyanine assemblies on a Cu(111) surface at different sub- to mono-layer coverages and the changes induced by thermal annealing at temperatures between 250 and 320 °C by scanning tunneling microscopy, x-ray photoelectron spectroscopy, and x-ray absorption spectroscopy. The symmetry breaking observed in scanning tunneling microscopy images is found to be coverage dependent and to persist upon annealing. Further, we find that annealing to temperatures between 300 and 320 °C leads to both desorption of iron phthalocyanine molecules from the surface and their agglomeration. We see clear evidence of temperature-induced homocoupling reactions of the iron phthalocyanine molecules following dehydrogenation of their isoindole rings, similar to what has been observed for related tetrapyrroles on transition metal surfaces. Finally, spectroscopy indicates a modified substrate-adsorbate interaction upon annealing with a shortened bond distance. This finding could potentially explain a changed reactivity of Cu-supported iron phthalocyanine in comparison to that of the pristine compound.

  19. Origin of two maxima in specific heat in enthalpy relaxation under thermal history composed of cooling, annealing, and heating.

    Science.gov (United States)

    Sakatsuji, Waki; Konishi, Takashi; Miyamoto, Yoshihisa

    2016-12-01

    The origin of two maxima in specific heat observed at the higher and the lower temperatures in the glass-transition region in the heating process has been studied for polymethyl methacrylate and polyvinyl chloride using differential scanning calorimetry, and the calculation was done using the phenomenological model equation under a thermal history of the typical annealing experiment composed of cooling, annealing, and heating. The higher maximum is observed above the glass-transition temperature, and it remains almost unchanged independent of annealing time t_{a}, while the lower one is observed above an annealing temperature T_{a} and shifts toward the higher one, increasing its magnitude with t_{a}. The analysis by the phenomenological model equation proposed in order to interpret the memory effect in the glassy state clarifies that under a typical annealing history, two maxima in specific heat essentially appear. The shift of the lower maximum toward higher temperatures from above T_{a} is caused by an increase in the amount of relaxation during annealing with t_{a}. The annealing temperature and the amount of relaxation during annealing play a major role in the determination of the number of maxima in the specific heat.

  20. Challenge for real-time and real-space resolved spectroscopy of surface chemical reactions. Aiming at trace of irreversible and inhomogeneous reactions

    International Nuclear Information System (INIS)

    Amemiya, Kenta

    2015-01-01

    A novel experimental technique, time-resolved wavelength-dispersive soft X-ray imaging spectroscopy, is proposed in order to achieve real-time and real-space resolved spectroscopy for the observation of irreversible and inhomogeneous surface chemical reactions. By combining the wavelength-dispersed soft X rays, in which the X-ray wavelength (photon energy) changes as a function of position on the sample, with the photoelectron emission microscope, the soft X-ray absorption spectra are separately obtained at different positions on the sample without scanning the X-ray monochromator. Therefore, the real-time resolved measurement of site-selective soft X-ray absorption spectroscopy is realized in one event without repeating the chemical reaction. It is expected that the spatial distribution of different chemical species is traced during the surface chemical reaction, which is essential to understand the reaction mechanism. (author)

  1. Unraveling Quantum Annealers using Classical Hardness

    Science.gov (United States)

    Martin-Mayor, Victor; Hen, Itay

    2015-01-01

    Recent advances in quantum technology have led to the development and manufacturing of experimental programmable quantum annealing optimizers that contain hundreds of quantum bits. These optimizers, commonly referred to as ‘D-Wave’ chips, promise to solve practical optimization problems potentially faster than conventional ‘classical’ computers. Attempts to quantify the quantum nature of these chips have been met with both excitement and skepticism but have also brought up numerous fundamental questions pertaining to the distinguishability of experimental quantum annealers from their classical thermal counterparts. Inspired by recent results in spin-glass theory that recognize ‘temperature chaos’ as the underlying mechanism responsible for the computational intractability of hard optimization problems, we devise a general method to quantify the performance of quantum annealers on optimization problems suffering from varying degrees of temperature chaos: A superior performance of quantum annealers over classical algorithms on these may allude to the role that quantum effects play in providing speedup. We utilize our method to experimentally study the D-Wave Two chip on different temperature-chaotic problems and find, surprisingly, that its performance scales unfavorably as compared to several analogous classical algorithms. We detect, quantify and discuss several purely classical effects that possibly mask the quantum behavior of the chip. PMID:26483257

  2. Thermal annealing study on P3HT: PCBM based bulk heterojunction organic solar cells using impedance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gollu, Sankara Rao, E-mail: sankar.gollu@gmail.com [Plastic Electronics and Energy Lab (PEEL), Department of Metallurgical Engineering and Material Science, Indian Institute of Technology Bombay, Powai, Mumbai-400076 (India); Sharma, Ramakant, E-mail: diptig@iitb.ac.in; G, Srinivas, E-mail: diptig@iitb.ac.in; Gupta, Dipti, E-mail: diptig@iitb.ac.in [Plastic Electronics and Energy Lab (PEEL) Department of Metallurgical Engineering and Material Science, Indian Institute of Technology Bombay, Powai, Mumbai-400076 (India)

    2014-10-15

    Recently, Thermal annealing is an important process for bulk heterojunction organic solar cells (BHJ OSCs) to improve the device efficiency and performance of the organic solar cells. Here in, we have examined the changes in the efficiency and morphology of P3HT: PCBM film according to the thermal annealing temperature to find the changes during the annealing process by measuring the optical absorption, atomic force microscope and X-ray diffraction. We also investigated the effect of different annealing process conditions (without, pre- and post-annealing) on the device performance of the inverted bulk heterojunction organic solar cells consist the structure of ITO/ ZnO / P3HT: PCBM / MoO{sub 3}/ Al by measuring AC impedance characteristics. Particularly, the power conversion efficiency (PCE), crystalline nature of the polymer, light absorption and the surface smoothness of P3HT: PCBM films are significantly improved after the annealing process. These results indicated the improvement in terms of PCE, interface smoothness between the P3HT: PCBM and MoO{sub 3} layers of the post annealed device originated from the decrease of series resistance between P3HT: PCBM layer and Al electrodes, which could be due to decrease in the effective life time of charge carriers.

  3. Effects of annealing on the compositional heterogeneity and structure in zirconium-based bulk metallic glass thin films

    International Nuclear Information System (INIS)

    He, L.; Chu, J.P.; Li, C.-L.; Lee, C.-M.; Chen, Y.-C.; Liaw, P.K.; Voyles, P.M.

    2014-01-01

    In-situ heating fluctuation electron microscopy and scanning transmission electron microscopy have been utilized to study compositional and structural heterogeneities in Zr 51 Cu 32 Al 9 Ni 8 thin films upon annealing. Composition fluctuations are present in the as-deposited thin films. Well below the glass transition temperature, the composition fluctuations increase with annealing time. Short- and medium-range order also change with annealing temperature. The observed heterogeneities in the glass structure persist until annealing causes crystallization. The 20 nm thick Zr 51 Cu 32 Al 9 Ni 8 films contain oxide layers both at the surface and the film/substrate interface with the total thickness of 7–8 nm. In-situ annealing increased the oxygen content of the whole films to about 24 wt.% after 2 h at 400 °C. - Highlights: • Zr 51 Cu 32 Al 9 Ni 8 thin films were studied with in-situ heating electron microscopy. • Annealing at 400 °C increases the Zr and Cu compositional fluctuations. • Short-range order in Zr 51 Cu 32 Al 9 Ni 8 becomes less homogeneous above 350 °C. • Medium-range order changes in degree and types at 400 °C, well below T g . • Annealing increases composition and structure heterogeneities until crystallization

  4. Reduced-Complexity Deterministic Annealing for Vector Quantizer Design

    Directory of Open Access Journals (Sweden)

    Ortega Antonio

    2005-01-01

    Full Text Available This paper presents a reduced-complexity deterministic annealing (DA approach for vector quantizer (VQ design by using soft information processing with simplified assignment measures. Low-complexity distributions are designed to mimic the Gibbs distribution, where the latter is the optimal distribution used in the standard DA method. These low-complexity distributions are simple enough to facilitate fast computation, but at the same time they can closely approximate the Gibbs distribution to result in near-optimal performance. We have also derived the theoretical performance loss at a given system entropy due to using the simple soft measures instead of the optimal Gibbs measure. We use thederived result to obtain optimal annealing schedules for the simple soft measures that approximate the annealing schedule for the optimal Gibbs distribution. The proposed reduced-complexity DA algorithms have significantly improved the quality of the final codebooks compared to the generalized Lloyd algorithm and standard stochastic relaxation techniques, both with and without the pairwise nearest neighbor (PNN codebook initialization. The proposed algorithms are able to evade the local minima and the results show that they are not sensitive to the choice of the initial codebook. Compared to the standard DA approach, the reduced-complexity DA algorithms can operate over 100 times faster with negligible performance difference. For example, for the design of a 16-dimensional vector quantizer having a rate of 0.4375 bit/sample for Gaussian source, the standard DA algorithm achieved 3.60 dB performance in 16 483 CPU seconds, whereas the reduced-complexity DA algorithm achieved the same performance in 136 CPU seconds. Other than VQ design, the DA techniques are applicable to problems such as classification, clustering, and resource allocation.

  5. Time-dependent, many-body scattering theory and nuclear reaction applications

    International Nuclear Information System (INIS)

    Levin, F.S.

    1977-01-01

    The channel component state form of the channel coupling array theory of many-body scattering is briefly reviewed. These states obey a non-hermitian matrix equation whose exact solution yields the Schroedinger eigenstates, eigenvalues and scattering amplitudes. A time-dependent formulation of the theory is introduced in analogy to the time-dependent Schrodinger equation and several consequences of the development are noted. These include an interaction picture, a single (matrix) S operator, and the usual connection between the t = 0 time-dependent and the time-independent scattering states. Finally, the channel component states (psi/sub j/) are shown to have the useful property that only psi/sub j/ has (two-body) outgoing waves in channel j: psi/sub m/, m not equal to j, is asymptotically zero in two-body channel j. This formalism is then considered as a means for direct nuclear reaction analysis. Typical bound state approximations are introduced and it is shown that a DWBA amplitude occurs in only one channel. The non-time-reversal invariance of the approximate theory is noted. Results of calculations based on a realistic model for two sets of light-ion induced, one-particle transfer reactions are discussed and compared with the coupled reaction channel (CRC) results using the CRC procedure of Cotanch and Vincent. Angular distributions for the two calculational methods are found to be similar in shape and magnitude. Higher ordercorrections are small as are time-reversal non-invariant effects. Post- and prior-type CRC calculations are seen to differ; the latter are closer to the full CRC results

  6. Effect of annealing on properties of Mg doped Zn-ferrite nanoparticles

    Directory of Open Access Journals (Sweden)

    K. Nadeem

    2015-04-01

    Full Text Available A comparison of structural and magnetic properties of as-prepared and annealed (900 °C Mg doped Zn ferrite nanoparticles (Zn1−xMgxFe2O4, with x=0, 0.1, 0.2, 0.3, 0.4 and 0.5 is presented. X-ray diffraction (XRD studies confirmed the cubic spinel structure for both the as-prepared and annealed nanoparticles. The average crystallite size and lattice parameter were increased by annealing. Scanning electron microscopy (SEM images also showed that the average particle size increased after annealing. Fourier transform infrared spectroscopy (FTIR also confirmed the spinel structure for both series of nanoparticles. For both annealed and as-prepared nanoparticles, the O–Mtet.–O vibrational band shifts towards higher wave numbers with increased Mg concentration due to cationic rearrangement on the lattice sites. Magnetization studies revealed an anomalous decreasing magnetization for the annealed nanoparticles which is also ascribed to cationic rearrangement on the lattice sites after annealing. The measurement of coercivity showed a decreasing trend by annealing due to the increased nanoparticle size and better crystallinity.

  7. Relativistic nucleus-nucleus collisions: Zone of reactions and space-time structure of fireball

    International Nuclear Information System (INIS)

    Anchishkin, D.; Muskeyev, A.; Yezhov, S.

    2010-01-01

    A zone of reactions is determined and then exploited as a tool in studying the space-time structure of an interacting system formed in a collision of relativistic nuclei. The time dependence of the reaction rates integrated over spatial coordinates is also considered. Evaluations are made with the help of the microscopic transport model UrQMD. The relation of the boundaries of different zones of reactions and the hypersurfaces of sharp chemical and kinetic freeze-outs is discussed.

  8. Embrittlement recovery due to annealing of reactor pressure vessel steels

    International Nuclear Information System (INIS)

    Eason, E.D.; Wright, J.E.; Nelson, E.E.; Odette, G.R.; Mader, E.V.

    1996-01-01

    Embrittlement of reactor pressure vessels (RPVs) can be reduced by thermal annealing at temperatures higher than the normal operating conditions. Although such an annealing process has not been applied to any commercial plants in the United States, one US Army reactor, the BR3 plant in Belgium, and several plants in eastern Europe have been successfully annealed. All available Charpy annealing data were collected and analyzed in this project to develop quantitative models for estimating the recovery in 30 ft-lb (41 J) Charpy transition temperature and Charpy upper shelf energy over a range of potential annealing conditions. Pattern recognition, transformation analysis, residual studies, and the current understanding of the mechanisms involved in the annealing process were used to guide the selection of the most sensitive variables and correlating parameters and to determine the optimal functional forms for fitting the data. The resulting models were fitted by nonlinear least squares. The use of advanced tools, the larger data base now available, and insight from surrogate hardness data produced improved models for quantitative evaluation of the effects of annealing. The quality of models fitted in this project was evaluated by considering both the Charpy annealing data used for fitting and the surrogate hardness data base. The standard errors of the resulting recovery models relative to calibration data are comparable to the uncertainty in unirradiated Charpy data. This work also demonstrates that microhardness recovery is a good surrogate for transition temperature shift recovery and that there is a high level of consistency between the observed annealing trends and fundamental models of embrittlement and recovery processes

  9. Annealing of the BR3 reactor pressure vessel

    International Nuclear Information System (INIS)

    Fabry, A.; Motte, F.; Stiennon, G.; Debrue, J.; Gubel, P.; Van de Velde, J.; Minsart, G.; Van Asbroeck, P.

    1985-01-01

    The pressure vessel of the Belgian BR-3 plant, a small (11 MWe) PWR presently used for fuel testing programs and operated since 1962, was annealed during March, 1984. The anneal was performed under wet conditions for 168 hours at 650 0 F with core removal and within plant design margins justification for the anneal, summary of plant characteristics, description of materials sampling, summary of reactor physics and dosimetry, development of embrittlement trend curves, hypothesized pressurized and overcooling thermal shock accidents, and conclusions are provided in detail

  10. Temporal Frequency Modulates Reaction Time Responses to First-Order and Second-Order Motion

    Science.gov (United States)

    Hutchinson, Claire V.; Ledgeway, Tim

    2010-01-01

    This study investigated the effect of temporal frequency and modulation depth on reaction times for discriminating the direction of first-order (luminance-defined) and second-order (contrast-defined) motion, equated for visibility using equal multiples of direction-discrimination threshold. Results showed that reaction times were heavily…

  11. Manipulation of magnetic properties of glass-coated microwires by annealing

    Energy Technology Data Exchange (ETDEWEB)

    Zhukov, A., E-mail: arkadi.joukov@ehu.es [Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU, 20009 San Sebastian (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain); Chichay, K. [Immanuel Kant Baltic Federal University, 236041 Kaliningrad (Russian Federation); Talaat, A. [Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU, 20009 San Sebastian (Spain); Rodionova, V. [Immanuel Kant Baltic Federal University, 236041 Kaliningrad (Russian Federation); National University of Science and Technology (MISIS), 119049 Moscow (Russian Federation); Blanco, J.M. [Dpto. Física Aplicada, EUPDS Basque Country University UPV/EHU (Spain); Ipatov, M.; Zhukova, V. [Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU, 20009 San Sebastian (Spain)

    2015-06-01

    We demonstrated that magnetic properties (hysteresis loops, domain wall propagation and giant magnetoimpedance effect) of Fe and Co-rich amorphous microwires can be tailored by stress and conventional annealing. Observed dependences discussed considering stress relaxation, back stresses and change of the magnetostriction after samples annealing. These considerations have been proved by experimental observation of the change of the magnetostriction coefficient sign induced by annealing. - Highlights: • Manipulation of hysteresis loop of amorphous Co–Fe- rich microwires by annealing. • Coexistence of Giant magnetoimpedance effect and fast domain wall propagation in the same sample. • Evidence of annealing dependence of the magnetostriction coefficient. • Effect of stress induced anisotropy on magnetic properties and GMI effect.

  12. Manipulation of magnetic properties of glass-coated microwires by annealing

    International Nuclear Information System (INIS)

    Zhukov, A.; Chichay, K.; Talaat, A.; Rodionova, V.; Blanco, J.M.; Ipatov, M.; Zhukova, V.

    2015-01-01

    We demonstrated that magnetic properties (hysteresis loops, domain wall propagation and giant magnetoimpedance effect) of Fe and Co-rich amorphous microwires can be tailored by stress and conventional annealing. Observed dependences discussed considering stress relaxation, back stresses and change of the magnetostriction after samples annealing. These considerations have been proved by experimental observation of the change of the magnetostriction coefficient sign induced by annealing. - Highlights: • Manipulation of hysteresis loop of amorphous Co–Fe- rich microwires by annealing. • Coexistence of Giant magnetoimpedance effect and fast domain wall propagation in the same sample. • Evidence of annealing dependence of the magnetostriction coefficient. • Effect of stress induced anisotropy on magnetic properties and GMI effect

  13. Calcium and zirconium as texture modifiers during rolling and annealing of magnesium–zinc alloys

    Energy Technology Data Exchange (ETDEWEB)

    Bohlen, Jan, E-mail: jan.bohlen@hzg.de; Wendt, Joachim; Nienaber, Maria; Kainer, Karl Ulrich; Stutz, Lennart; Letzig, Dietmar

    2015-03-15

    Rolling experiments were carried out on a ternary Mg–Zn–Ca alloy and its modification with zirconium. Short time annealing of as-rolled sheets is used to reveal the microstructure and texture development. The texture of the as-rolled sheets can be characterised by basal pole figures with split peak towards the rolling direction (RD) and a broad transverse angular spread of basal planes towards the transverse direction (TD). During annealing the RD split peaks as well as orientations in the sheet plane vanish whereas the distribution of orientations tilted towards the TD remains. It is shown in EBSD measurements that during rolling bands of twin containing structures form. During subsequent annealing basal orientations close to the sheet plane vanish based on a grain nucleation and growth mechanism of recrystallisation. Orientations with tilt towards the TD remain in grains that do not undergo such a mechanism. The addition of Zr delays texture weakening. - Highlights: • Ca in Mg–Zn-alloys contributes to a significant texture weakening during rolling and annealing. • Grain nucleation and growth in structures consisting of twins explain a texture randomisation during annealing. • Grains with transverse tilt of basal planes preferentially do not undergo a grain nucleation and growth mechanism. • Zr delays the microstructure and texture development.

  14. Characterization of in-situ annealed sub-micron thick Cu(In,Ga)Se{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Byoung-Soo; Sung, Shi-Joon; Hwang, Dae-Kue, E-mail: dkhwang@dgist.ac.kr

    2015-09-01

    Sub-micron thick Cu(In,Ga)Se{sub 2} (CIGS) thin films were deposited on Mo-coated soda-lime glass substrates under various conditions by single-stage co-evaporation. Generally, the short circuit current (J{sub sc}) decreased with the decreasing thickness of the absorber layer. However, in this study, J{sub sc} was nearly unchanged with decreasing thickness, while the open circuit voltage (V{sub oc}) and fill factor (FF) decreased by 31.9 and 31.1%, respectively. We believe that the remarkable change of V{sub oc} and FF can be attributed to the difference in the total amount of injected thermal energy. Using scanning electron microscopy, we confirmed that the surface morphology becomes smooth and the grain size increased after the annealing process. In the X-ray diffraction patterns, the CIGS thin film also showed an improved crystal quality. We observed that the electric properties were improved by the in-situ annealing of CIGS thin films. The reverse saturation current density of the annealed CIGS solar cell was 100 times smaller than that of reference solar cell. Thus, sub-micron CIGS thin films annealed under a constant Se rate showed a 64.7% improvement in efficiency. - Highlights: • The effects of in-situ annealing the sub-micron CIGS film have been investigated. • The surface morphology and the grain size were improved by in-situ annealing. • The V{sub oc} and FF of the films were increased by about 30% after in-situ annealing. • In-situ annealing of sub-micron thick CIGS films can be improved an efficiency.

  15. In situ annealing of hydroxyapatite thin films

    International Nuclear Information System (INIS)

    Johnson, Shevon; Haluska, Michael; Narayan, Roger J.; Snyder, Robert L.

    2006-01-01

    Hydroxyapatite is a bioactive ceramic that mimics the mineral composition of natural bone. Unfortunately, problems with adhesion, poor mechanical integrity, and incomplete bone ingrowth limit the use of many conventional hydroxyapatite surfaces. In this work, we have developed a novel technique to produce crystalline hydroxyapatite thin films involving pulsed laser deposition and postdeposition annealing. Hydroxyapatite films were deposited on Ti-6Al-4V alloy and Si (100) using pulsed laser deposition, and annealed within a high temperature X-ray diffraction system. The transformation from amorphous to crystalline hydroxyapatite was observed at 340 deg. C. Mechanical and adhesive properties were examined using nanoindentation and scratch adhesion testing, respectively. Nanohardness and Young's modulus values of 3.48 and 91.24 GPa were realized in unannealed hydroxyapatite films. Unannealed and 350 deg. C annealed hydroxyapatite films exhibited excellent adhesion to Ti-6Al-4V alloy substrates. We anticipate that the adhesion and biological properties of crystalline hydroxyapatite thin films may be enhanced by further consideration of deposition and annealing parameters

  16. Thermal engineering of FAPbI3 perovskite material via radiative thermal annealing and in situ XRD

    Science.gov (United States)

    Pool, Vanessa L.; Dou, Benjia; Van Campen, Douglas G.; Klein-Stockert, Talysa R.; Barnes, Frank S.; Shaheen, Sean E.; Ahmad, Md I.; van Hest, Maikel F. A. M.; Toney, Michael F.

    2017-01-01

    Lead halide perovskites have emerged as successful optoelectronic materials with high photovoltaic power conversion efficiencies and low material cost. However, substantial challenges remain in the scalability, stability and fundamental understanding of the materials. Here we present the application of radiative thermal annealing, an easily scalable processing method for synthesizing formamidinium lead iodide (FAPbI3) perovskite solar absorbers. Devices fabricated from films formed via radiative thermal annealing have equivalent efficiencies to those annealed using a conventional hotplate. By coupling results from in situ X-ray diffraction using a radiative thermal annealing system with device performances, we mapped the processing phase space of FAPbI3 and corresponding device efficiencies. Our map of processing-structure-performance space suggests the commonly used FAPbI3 annealing time, 10 min at 170 °C, can be significantly reduced to 40 s at 170 °C without affecting the photovoltaic performance. The Johnson-Mehl-Avrami model was used to determine the activation energy for decomposition of FAPbI3 into PbI2. PMID:28094249

  17. The effects of pre-dose and annealing temperature on some dosimetric properties of thermoluminescence of quartz

    International Nuclear Information System (INIS)

    Lin Zhikai

    1996-02-01

    The following aspects of dosimetric properties of quartz sample were studied. (1) The changes in dosimetric sensitivity of quartz with different pre-doses under different annealing temperature; (2) the option of optimal annealing temperature which can make the dosimetric sensitivity of quartz to restore its original level; (3) The changes in dosimetric sensitivity of quartz with different annealing time at 500 degree C for 8 h; (4) Repeated experiments were carried out in order to prove whether the sensitivity of quartz can restore its original level at annealing temperature 700 degree C for 3 h. It has been found that at 700 degree C for 3 h gave the least sensitivity change and the sensitivity of quartz almost restored its original level. Repeated experiments with four kinds of quartz sample confirmed this conclusion. The dramatic change of TL glow curve occurred only at the condition of annealing temperature 900 degree C for 1 h. This result was different from that obtained by D. J. Huntley et al. (1988). (3 refs., 4 figs., 1 tab.)

  18. Structural evolution of Fe-50 at.% Al powders during mechanical alloying and subsequent annealing processes

    International Nuclear Information System (INIS)

    Haghighi, Sh. Ehtemam; Janghorban, K.; Izadi, S.

    2010-01-01

    Iron aluminides, despite having desirable properties like excellent corrosion resistance, present low room-temperature ductility and low strength at high temperatures. Mechanical alloying as a capable process to synthesize nanocrystalline materials is under consideration to modify these drawbacks. In this study, the microstructure of iron aluminide powders synthesized by mechanical alloying and subsequent annealing was investigated. Elemental Fe and Al powders with the same atomic percent were milled in a planetary ball mill for 15 min to 100 h. The powder milled for 80 h was annealed at temperatures of 300, 500 and 700 o C for 1 h. The alloyed powders were disordered Fe(Al) solid solutions which were transformed to FeAl intermetallic after annealing. The effect of the milling time and annealing treatment on structural parameters, such as crystallite size, lattice parameter and lattice strain was evaluated by X-ray diffraction. Typically, these values were 15 nm, 2.92 A and 3.1% for the disordered Fe(Al) solid solution milled for 80 h and were 38.5 nm, 2.896 A and 1.2% for the FeAl intermetallic annealed at 700 o C, respectively.

  19. Effects of uncertainty, transmission type, driver age and gender on brake reaction and movement time.

    Science.gov (United States)

    Warshawsky-Livne, Lora; Shinar, David

    2002-01-01

    Braking time (BT) is a critical component in safe driving, and various approaches have been applied to minimize it. This study analyzed the components of BT in order to assess the effects of age, gender, vehicle transmission type, and event uncertainty, on its two primary components, perception-reaction time and brake-movement time. Perception-reaction time and brake-movement time were measured at the onset of lights for 72 subjects in a simulator. The six experimental conditions were three levels of uncertainty conditions (none, some, and some + false alarms) and two types of transmission (manual and automatic). The 72 subjects, half male and half female, were further divided into three age groups (mean of 23, 30, and 62 years). Each subject had 10 trials in each of the three levels of uncertainty conditions. Transmission type did not significantly affect either perception-reaction time or brake-movement time. Perception-reaction time increased significantly from 0.32 to 0.42 s (P brake-movement time did not change. Perception-reaction time increased (from 0.35 to 0.43 s) with age but brake-movement time did not change with age. Gender did not affect perception-reaction time but did affect brake-movement time (males 0.19 s vs. females 0.16 s). At 90 km/h, a car travels 0.25 m in 0.01 s. Consequently, even such small effects multiplied by millions of vehicle-kilometers can contribute to significant savings in lives and damages.

  20. The coercivity mechanism of sintered SM(Co_b_a_lFe_0_._2_4_5Cu_0_._0_7Zr_0_._0_2)_7_._8 permanent magnets with different isothermal annealing time

    International Nuclear Information System (INIS)

    Sun, Wei; Zhu, Minggang; Guo, Zhaohui; Fang, Yikun; Li, Wei

    2015-01-01

    Precipitation-hardened 2:17-type SmCo permanent magnet has attracted much attention due to its high Curie temperature and excellent magnetic properties. Sm(Co_b_a_lFe_0_._2_4_5Cu_0_._0_7Zr_0_._0_2)_7_._8 (at%) sintered magnets with high remanence (B_r ~1.15 T) were prepared using a traditional powder metallurgy method. The intrinsic coercivity H_c_j of the magnets was increased from 429 to 994 kA m"−"1 with isothermal annealing time increasing from 10 to 40 h, which is different from the phenomenon that increasing aging time leads to a reduced coercivity mentioned in the Ref. [16]. In consideration of rarely report about the microstructure of the final magnet isothermally annealed for 40 h, we have tried to originally analyze the relationship between the microstructure and the magnetic properties. Besides, the lattice constants of sintered Sm(Co_b_a_lFe_0_._2_4_5Cu_0_._0_7Zr_0_._0_2)_7_._8 permanent magnet isothermally annealed for 40 h have been given by indexing the HRTEM results including the selected area electron diffraction (SAED) and HRTEM images.

  1. An assessment of the economic consequences of thermal annealing of a nuclear reactor pressure vessel

    International Nuclear Information System (INIS)

    Griesbach, T.J.; Server, W.L.

    1991-01-01

    The use of a thermal heat treatment to recover mechanical properties which were degraded by neutron radiation exposure is a potential method for assuring reactor pressure vessel licensing life and possible license renewal. 'Wet anneals' at temperatures less than 343degC have been conducted on test reactors in Alaska (SM-1A) and Belgium (BR3). The Soviets have also performed 'dry anneals' at higher temperatures near or above 450degC on several commercial reactor vessels. Technical and economic uncertainties have made utilities in the United States reluctant to seriously consider thermal annealing of large commercial reactor vessels except as a last resort option. However, as a utility begins to experience significant radiation embrittlement or considers extending the operating license life of the vessel, thermal annealing can be a viable option depending upon many considerations. These considerations include other possible remedial measures that can be taken (i.e., flux reduction), economic issues with regard to utility finances, and corporate philosophy. A decision analysis model has been developed to analyze the thermal anneal option in comparison to other alternatives for a number of possible combinations and timing. The results for a postulated vessel and embrittlement condition are presented to show that thermal annealing can be a viable management option which should be taken seriously. (author)

  2. Defect evolution and dopant activation in laser annealed Si and Ge

    DEFF Research Database (Denmark)

    Cristiano, F.; Shayesteh, M.; Duffy, R.

    2016-01-01

    Defect evolution and dopant activation are intimately related to the use of ion implantation and annealing, traditionally used to dope semiconductors during device fabrication. Ultra-fast laser thermal annealing (LTA) is one of the most promising solutions for the achievement of abrupt and highly...... doped junctions. In this paper, we report some recent investigations focused on this annealing method, with particular emphasis on the investigation of the formation and evolution of implant/anneal induced defects and their impact on dopant activation. In the case of laser annealed Silicon, we show...

  3. Decoding flow unit evolution upon annealing from fracture morphology in metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Gao, M., E-mail: gaomeng10@hotmail.com; Cao, X.F.; Ding, D.W.; Wang, B.B.; Wang, W.H., E-mail: whw@iphy.ac.cn

    2017-02-16

    The intrinsic correlation between the fracture morphology evolution and the structural heterogeneity of flow units in a typical Zr{sub 52.5}Ti{sub 5}Cu{sub 17.9}Ni{sub 14.6}Al{sub 10} (vit105) metallic glass (MG) upon annealing was investigated. By systematically tuning the annealing time at temperature below the glass transition temperature, a series of dimple-like fracture morphology were obtained, which is the unique fingerprint-like pattern for every annealing state. Based on the structural relaxation model of flow units, the evolution of the typical dimple sizes, the largest and smallest dimple size, with annealing were well fitted. Then the evolution of flow unit density was estimated from the fracture morphology evolution, which displays the same evolution trend with that measured from thermal relaxation. A stochastic dynamic model considering the interaction of activated flow units was proposed to analyze the effect of the initial flow unit density and the flow unit interaction intensity on the dynamic evolution of dimple distribution. Our work may provide a novel scheme to investigate the structural fingerprint information on flow units from fracture morphology, and enlighten the microscopic structural origin of the ductile-to-brittle transition during structural relaxation in MGs.

  4. Self-Healing Thermal Annealing: Surface Morphological Restructuring Control of GaN Nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Conroy, Michele; Li, Haoning; Zubialevich, Vitaly Z.; Kusch, Gunnar; Schmidt, Michael; Collins, Timothy; Glynn, Colm; Martin, Robert W.; O’Dwyer, Colm; Morris, Michael D.; Holmes, Justin D.; Parbrook, Peter J.

    2016-12-07

    With advances in nanolithography and dry etching, top-down methods of nanostructuring have become a widely used tool for improving the efficiency of optoelectronics. These nano dimensions can offer various benefits to the device performance in terms of light extraction and efficiency, but often at the expense of emission color quality. Broadening of the target emission peak and unwanted yellow luminescence are characteristic defect-related effects due to the ion beam etching damage, particularly for III–N based materials. In this article we focus on GaN based nanorods, showing that through thermal annealing the surface roughness and deformities of the crystal structure can be “self-healed”. Correlative electron microscopy and atomic force microscopy show the change from spherical nanorods to faceted hexagonal structures, revealing the temperature-dependent surface morphology faceting evolution. The faceted nanorods were shown to be strain- and defect-free by cathodoluminescence hyperspectral imaging, micro-Raman, and transmission electron microscopy (TEM). In-situ TEM thermal annealing experiments allowed for real time observation of dislocation movements and surface restructuring observed in ex-situ annealing TEM sampling. This thermal annealing investigation gives new insight into the redistribution path of GaN material and dislocation movement post growth, allowing for improved understanding and in turn advances in optoelectronic device processing of compound semiconductors.

  5. Effect of the annealing environment on the optical properties of ZnO/GaAs grown by MOCVD

    International Nuclear Information System (INIS)

    Dangbegnon, J.K.; Talla, K.; Botha, J.R.

    2011-01-01

    The optical properties of ZnO grown on (1 0 0) GaAs substrate using metalorganic chemical vapor deposition are investigated by photoluminescence (PL) spectroscopy. Postgrowth annealing in nitrogen and oxygen was performed for different times and temperatures in order to incorporate As from the substrate into the ZnO thin films. The PL spectra of the samples annealed in different ambients reveal that the effect of As diffusion into the ZnO thin films is more pronounced when the annealing is performed in oxygen at 550 o C. The 11 K PL spectra show the appearance of a transition at ∼3.35 eV after annealing in oxygen at 550 deg. C for 1 h. A further increase in the annealing temperature leads to the disappearance of this line, while for annealing times longer than 2 h at 550 o C, it is no longer prominent. The increase in intensity of this new transition is also accompanied by the enhancement of radiative centers related to structural defects, such as the stacking fault-related transition at 3.31 eV and the Y-line. Temperature dependent PL illustrates the excitonic nature of the new transition at ∼3.35 eV, which is therefore assigned to (A 0 , X) transition, where the acceptor is possibly the 2V Zn -As Zn complex, with an activation energy E A in the range of 160-240 meV. Furthermore, the enhancement of the radiative centers related to structural defects is regarded as evidence that As atoms tend to segregate in the vicinity of structural defects to relieve local strain. - Highlights: → (A 0 , X) and DAP transitions at 3.35 and 3.26 eV related to arsenic acceptor. → Oxygen annealing ambient promotes arsenic acceptor into ZnO films. → Increase in structural defect lines is related to arsenic incorporation. → Annealing at optimal temperature of around 550 deg. C is necessary for arsenic incorporation.

  6. In-situ cyclic pulse annealing of InN on AlN/Si during IR-lamp-heated MBE growth

    Science.gov (United States)

    Suzuki, Akira; Bungi, Yu; Araki, Tsutomu; Nanishi, Yasushi; Mori, Yasuaki; Yamamoto, Hiroaki; Harima, Hiroshi

    2009-05-01

    To improve crystal quality of InN, an in-situ cyclic rapid pulse annealing during growth was carried out using infrared-lamp-heated molecular beam epitaxy. A cycle of 4 min growth of InN at 400 °C and 3 s pulse annealing at a higher temperature was repeated 15 times on AlN on Si substrate. Annealing temperatures were 550, 590, 620, and 660 °C. The back of Si was directly heated by lamp irradiation through a quartz rod. A total InN film thickness was about 200 nm. With increasing annealing temperature up to 620 °C, crystal grain size by scanning electron microscope showed a tendency to increase, while widths of X-ray diffraction rocking curve of (0 0 0 2) reflection and E 2 (high) mode peak of Raman scattering spectra decreased. A peak of In (1 0 1) appeared in X-ray diffraction by annealing higher than 590 °C, and In droplets were found on the surface by annealing at 660 °C.

  7. Annealing behavior of solution grown polyethylene single crystals

    NARCIS (Netherlands)

    Loos, J.; Tian, M.

    2006-01-01

    The morphology evolution of solution grown polyethylene single crystals has been studied upon annealing below their melting temperature by using atomic force microscopy (AFM). AFM investigations have been performed ex situ, which means AFM investigations at room temperature after the annealing

  8. Investigation on fuel-cladding chemical interaction in metal fuel for FBR. Reaction of rare earth elements with Fe-Cr alloy

    International Nuclear Information System (INIS)

    Inagaki, Kenta; Ogata, Takanari

    2010-01-01

    Rare-earth fission product (FP) elements generated in the metal fuel interact with cladding alloy and result in the wastage of the cladding (Fuel-Cladding Chemical Interaction (FCCI)). To evaluate FCCI quantitatively, several influential factors must be considered. They are temperature, temperature gradient, time, composition of the cladding and the behavior of rare-earth FP. In this research, the temperature and time dependencies are investigated with tests in the simplified system. Fe-12wt%Cr was used as stimulant material of cladding and rare-earth alloy 13La -24Ce -12Pr -39Nd -12Sm (RE) as a rare-earth FP. A diffusion couple Fe-Cr/RE was made and annealed at 923K, 853K, 773K or 693K. The structures of reaction layers were analyzed with Electron Probe Micro Analyzer (EPMA) and the details of the structures were clarified. The width of the reaction layer in the Fe-Cr alloy grew in proportion to the square root of time. The reaction rate constants K=(square of the width of reaction layer / time) were evaluated. It was confirmed that the relation between K and the inverse of the temperature showed linearity above 773 K. (author)

  9. Annealing temperature effect on self-assembled Au droplets on Si (111).

    Science.gov (United States)

    Sui, Mao; Li, Ming-Yu; Kim, Eun-Soo; Lee, Jihoon

    2013-12-13

    We investigate the effect of annealing temperature on self-assembled Au droplets on Si (111). The annealing temperature is systematically varied while fixing other growth parameters such as deposition amount and annealing duration clearly to observe the annealing temperature effect. Self-assembled Au droplets are fabricated by annealing from 50°C to 850°C with 2-nm Au deposition for 30 s. With increased annealing temperatures, Au droplets show gradually increased height and diameter while the density of droplets progressively decreases. Self-assembled Au droplets with fine uniformity can be fabricated between 550°C and 800°C. While Au droplets become much larger with increased deposition amount, the extended annealing duration only mildly affects droplet size and density. The results are systematically analyzed with cross-sectional line profiles, Fourier filter transform power spectra, height histogram, surface area ratio, and size and density plots. This study can provide an aid point for the fabrication of nanowires on Si (111).

  10. Annealing effects on electron-beam evaporated Al2O3 films

    International Nuclear Information System (INIS)

    Shang Shuzhen; Chen Lei; Hou Haihong; Yi Kui; Fan Zhengxiu; Shao Jianda

    2005-01-01

    The effects of post-deposited annealing on structure and optical properties of electron-beam evaporated Al 2 O 3 single layers were investigated. The films were annealed in air for 1.5 h at different temperatures from 250 to 400 deg. C. The optical constants and cut-off wavelength were deduced. Microstructure of the samples was characterized by X-ray diffraction (XRD). Profile and surface roughness measurement instrument was used to determine the rms surface roughness. It was found that the cut-off wavelength shifted to short wavelength as the annealing temperature increased and the total optical loss decreased. The film structure remained amorphous even after annealing at 400 deg. C temperature and the samples annealed at higher temperature had the higher rms surface roughness. The decreasing total optical loss with annealing temperature was attributed to the reduction of absorption owing to oxidation of the film by annealing. Guidance to reduce the optical loss of excimer laser mirrors was given

  11. Annealing effects on electron-beam evaporated Al 2O 3 films

    Science.gov (United States)

    Shuzhen, Shang; Lei, Chen; Haihong, Hou; Kui, Yi; Zhengxiu, Fan; Jianda, Shao

    2005-04-01

    The effects of post-deposited annealing on structure and optical properties of electron-beam evaporated Al 2O 3 single layers were investigated. The films were annealed in air for 1.5 h at different temperatures from 250 to 400 °C. The optical constants and cut-off wavelength were deduced. Microstructure of the samples was characterized by X-ray diffraction (XRD). Profile and surface roughness measurement instrument was used to determine the rms surface roughness. It was found that the cut-off wavelength shifted to short wavelength as the annealing temperature increased and the total optical loss decreased. The film structure remained amorphous even after annealing at 400 °C temperature and the samples annealed at higher temperature had the higher rms surface roughness. The decreasing total optical loss with annealing temperature was attributed to the reduction of absorption owing to oxidation of the film by annealing. Guidance to reduce the optical loss of excimer laser mirrors was given.

  12. Hydration-annealing of chemical radiation damage in calcium nitrate

    International Nuclear Information System (INIS)

    Nair, S.M.K.; James, C.

    1984-01-01

    The effect of hydration on the annealing of chemical radiation damage in anhydrous calcium nitrate has been investigated. Rehydration of the anhydrous irradiated nitrate induces direct recovery of the damage. The rehydrated salt is susceptible to thermal annealing but the extent of annealing is small compared to that in the anhydrous salt. The direct recovery of damage on rehydration is due to enhanced lattice mobility. The recovery process is unimolecular. (author)

  13. Time-resolved FTIR emission studies of laser photofragmentation and radical reactions

    Energy Technology Data Exchange (ETDEWEB)

    Leone, S.R. [Univ. of Colorado, Boulder (United States)

    1993-12-01

    Recent studies have focused specifically on collision processes, such as single collision energy transfer, reaction dynamics, and radical reactions. The authors employ novel FTIR techniques in the study of single collision energy transfer processes using translationally fast H atom, as well as radical-radical reactions, e.g. CH{sub 3} + O, CF{sub 3} + H(D), and Cl + C{sub 2}H{sub 5}. The fast atoms permit unique high energy regions of certain transition states of combustion species to be probed for the first time.

  14. Effect of low thermal budget annealing on surface passivation of silicon by ALD based aluminum oxide films.

    Science.gov (United States)

    Vandana; Batra, Neha; Gope, Jhuma; Singh, Rajbir; Panigrahi, Jagannath; Tyagi, Sanjay; Pathi, P; Srivastava, S K; Rauthan, C M S; Singh, P K

    2014-10-21

    Thermal ALD deposited Al2O3 films on silicon show a marked difference in surface passivation quality as a function of annealing time (using a rapid thermal process). An effective and quality passivation is realized in short anneal duration (∼100 s) in nitrogen ambient which is reflected in the low surface recombination velocity (SRV passivation. Both as-deposited and low thermal budget annealed films show the presence of positive fixed charges and this is never been reported in the literature before. The role of field and chemical passivation is investigated in terms of fixed charge and interface defect densities. Further, the importance of the annealing step sequence in the MIS structure fabrication protocol is also investigated from the view point of its effect on the nature of fixed charges.

  15. Reaction layer growth and reaction heat of U-Mo/Al dispersion fuels using centrifugally atomized powders

    International Nuclear Information System (INIS)

    Ryu, Ho Jin; Han, Young Soo; Park, Jong Man; Park, Soon Dal; Kim, Chang Kyu

    2003-01-01

    The growth behavior of reaction layers and heat generation during the reaction between U-Mo powders and the Al matrix in U-Mo/Al dispersion fuels were investigated. Annealing of 10 vol.% U-10Mo/Al dispersion fuels at temperatures from 500 to 550 deg. C was carried out for 10 min to 36 h to measure the growth rate and the activation energy for the growth of reaction layers. The concentration profiles of reaction layers between the U-10Mo vs. Al diffusion couples were measured and the integrated interdiffusion coefficients were calculated for the U and Al in the reaction layers. Heat generation of U-Mo/Al dispersion fuels with 10-50 vol.% of U-Mo fuel during the thermal cycle from room temperature to 700 deg. C was measured employing the differential scanning calorimetry. Exothermic heat from the reaction between U-Mo and the Al matrix is the largest when the volume fraction of U-Mo fuel is about 30 vol.%. The unreacted fraction in the U-Mo powders increases as the volume fraction of U-Mo fuel increases from 30 to 50 vol.%

  16. Annealing Studies of irradiated p-type Sensors Designed for the Upgrade of ATLAS Phase-II Strip Tracker

    CERN Document Server

    Wiik-Fuchs, Liv Antje Mari; The ATLAS collaboration

    2018-01-01

    The upgrade for the High Luminosity LHC in 2025 will challenge the silicon strip detector performance with high fluence and long operation time. Sensors have been designed and tests on charge collection and electrical performance have been carried out in order to evaluate their behaviour. Besides that, it is important to understand and predict the long-term evolution of the sensor prop- erties. In this work, detailed studies on the annealing behaviour of ATLAS12 strip sensors designed by the ITK Strip Sensor Working Group and irradiated from 5 × 1013 neqcm−2 to 2 × 1015 neqcm−2 are presented. Systematic charge collection, leakage current and impedance measurements have been carried out during the annealing time at 23 and 60◦C until break-down or the appearance of charge multiplication. Sensors showing charge multiplication have been then kept at high voltage for a long time in order to monitor their stability. The difference in the annealing behaviour between the two temperatures has been analysed and...

  17. Annealing studies of irradiated p-type sensors designed for the upgrade of ATLAS Phase-II Strip Tracker

    CERN Document Server

    Wiik-Fuchs, Liv Antje Mari; The ATLAS collaboration

    2018-01-01

    The upgrade for the High Luminosity LHC in 2025 will challenge the silicon strip detector performance with high fluence and long operation time. Sensors have been designed and tests on charge collection and electrical performance have been carried out in order to evaluate their behavior. Besides that, it is important to understand and predict the long-term evolution of the sensor properties. In this work, we present detailed studies on the annealing behavior of ATLAS12 strip sensors designed by the ITK Strip Sensor Working Group and irradiated from 510^13 to 210^15 n_eq/cm^2. Systematic charge collection, leakage current and impedance measurements have been carried out during the annealing time at 23 and 60°C until break-down or the appearance of charge multiplication. Sensors showing charge multiplication have been then kept at high voltage for a long time in order to monitor their stability. The difference in the annealing behavior between the two temperatures has been analyzed. From the impedance measurem...

  18. Hysteresis in Lanthanide Zirconium Oxides Observed Using a Pulse CV Technique and including the Effect of High Temperature Annealing.

    Science.gov (United States)

    Lu, Qifeng; Zhao, Chun; Mu, Yifei; Zhao, Ce Zhou; Taylor, Stephen; Chalker, Paul R

    2015-07-29

    A powerful characterization technique, pulse capacitance-voltage (CV) technique, was used to investigate oxide traps before and after annealing for lanthanide zirconium oxide thin films deposited on n-type Si (111) substrates at 300 °C by liquid injection Atomic Layer Deposition (ALD). The results indicated that: (1) more traps were observed compared to the conventional capacitance-voltage characterization method in LaZrO x ; (2) the time-dependent trapping/de-trapping was influenced by the edge time, width and peak-to-peak voltage of a gate voltage pulse. Post deposition annealing was performed at 700 °C, 800 °C and 900 °C in N₂ ambient for 15 s to the samples with 200 ALD cycles. The effect of the high temperature annealing on oxide traps and leakage current were subsequently explored. It showed that more traps were generated after annealing with the trap density increasing from 1.41 × 10 12 cm -2 for as-deposited sample to 4.55 × 10 12 cm -2 for the 800 °C annealed one. In addition, the leakage current density increase from about 10 - ⁶ A/cm² at V g = +0.5 V for the as-deposited sample to 10 -3 A/cm² at V g = +0.5 V for the 900 °C annealed one.

  19. Hysteresis in Lanthanide Zirconium Oxides Observed Using a Pulse CV Technique and including the Effect of High Temperature Annealing

    Directory of Open Access Journals (Sweden)

    Qifeng Lu

    2015-07-01

    Full Text Available A powerful characterization technique, pulse capacitance-voltage (CV technique, was used to investigate oxide traps before and after annealing for lanthanide zirconium oxide thin films deposited on n-type Si (111 substrates at 300 °C by liquid injection Atomic Layer Deposition (ALD. The results indicated that: (1 more traps were observed compared to the conventional capacitance-voltage characterization method in LaZrOx; (2 the time-dependent trapping/de-trapping was influenced by the edge time, width and peak-to-peak voltage of a gate voltage pulse. Post deposition annealing was performed at 700 °C, 800 °C and 900 °C in N2 ambient for 15 s to the samples with 200 ALD cycles. The effect of the high temperature annealing on oxide traps and leakage current were subsequently explored. It showed that more traps were generated after annealing with the trap density increasing from 1.41 × 1012 cm−2 for as-deposited sample to 4.55 × 1012 cm−2 for the 800 °C annealed one. In addition, the leakage current density increase from about 10−6 A/cm2 at Vg = +0.5 V for the as-deposited sample to 10−3 A/cm2 at Vg = +0.5 V for the 900 °C annealed one.

  20. Reduction of thermal quenching of biotite mineral due to annealing

    International Nuclear Information System (INIS)

    Kalita, J.M.; Wary, G.

    2014-01-01

    Graphical abstract: - Highlights: • Thermoluminescence of X-ray irradiate biotite was studied at various heating rates. • Thermal quenching was found to decrease with increase in annealing temperature. • Due to annealing one trap level was vanished and a new shallow trap level generated. • The new trap level contributes low thermally quenched thermoluminescence signal. - Abstract: Thermoluminescence (TL) of X-ray irradiated natural biotite annealed at 473, 573, 673 and 773 K were studied within 290–480 K at various linear heating rates (2, 4, 6, 8 and 10 K/s). A Computerized Glow Curve Deconvolution technique was used to study various TL parameters. Thermal quenching was found to be very high for un-annealed sample, however it decreased significantly with increase in annealing temperature. For un-annealed sample thermal quenching activation energy (W) and pre-exponential frequency factor (C) were found to be W = (2.71 ± 0.05) eV and C = (2.38 ± 0.05) × 10 12 s −1 respectively. However for 773 K annealed sample, these parameters were found to be W = (0.63 ± 0.03) eV, C = (1.75 ± 0.27) × 10 14 s −1 . Due to annealing, the initially present trap level at depth 1.04 eV was vanished and a new shallow trap state was generated at depth of 0.78 eV which contributes very low thermally quenched TL signal

  1. Effect of Annealing on the Thermoluminescence Properties of ZnO Nanophosphor

    Science.gov (United States)

    Kalita, J. M.; Wary, G.

    2017-07-01

    We report the effect of annealing on the thermoluminescence (TL) properties of zinc oxide (ZnO) nanophosphor. The sample was synthesised by a wet chemical process. The characterisation report shows that the size of the grains is within 123.0 nm-160.5 nm. TL measured at 2 K/s from a fresh un-annealed sample irradiated to 60 mGy shows a composite glow curve containing three peaks at 353.2 K, 429.1 K, and 455.3 K. On the other hand, samples annealed at 473 K and 573 K followed by irradiation to 60 mGy do not give TL. However, annealing at 673 K and 773 K followed by irradiation to the same dose produces a glow curve comprising two overlapping peaks at 352.3 K and 370.6 K. In the TL emission spectrum of un-annealed sample, two emission peaks were found in green ( 523 nm) and orange ( 620 nm) regions whereas in annealed samples, only a peak was found in the orange region ( 618 nm). Kinetic analysis shows that the activation energy corresponding to TL peaks at 353.2 K, 429.1 K, and 455.3 K of the un-annealed sample are 0.64 eV, 0.80 eV, and 1.20 eV whereas that of the peaks at 352.3 K and 370.6 K of 673 K and 773 K annealed samples are 0.64 eV and 0.70 eV, respectively. All peaks of un-annealed and annealed samples, except the one at 429.1 K of the un-annealed sample, follow first-order kinetics whereas the peak at 429.1 K follows second-order kinetics. Considering the kinetic and spectral features, an energy band model for ZnO nanophosphor has been proposed.

  2. Comparison of boron diffusion in silicon during shallow p{sup +}/n junction formation by non-melt excimer and green laser annealing

    Energy Technology Data Exchange (ETDEWEB)

    Aid, Siti Rahmah; Matsumoto, Satoru [Department of Electronics and Electrical Engineering, Keio University, 3-14-1 Hiyoshi, Kouhoku-ku, Yokohama, Kanagawa 223-8522 (Japan); Fuse, Genshu [SEN Corporation, SBS Tower 9F, 4-10-1 Yoga, Setagaya-ku, Tokyo 158-0097 (Japan); Sakuragi, Susumu [Sumitomo Heavy Industries Ltd., 19 Natsushima-cho, Yokosuka, Kanagawa 237-8555 (Japan)

    2011-12-15

    The combination of Ge pre-amorphization implantation, low-energy boron implantation, and non-melt laser annealing is a promising method for forming ultrashallow p{sup +}/n junctions in silicon. In this study, shallow p{sup +}/n junctions were formed by non-melt annealing implanted samples using a green laser (visible laser). The dopant diffusion, activation, and recrystallization of an amorphous silicon layer were compared with those obtained in our previous study in which non-melt annealing was performed using a KrF excimer laser (UV laser). The experimental results reveal that only slight diffusion of boron in the tail region occurred in green-laser-annealed samples. In contrast, remarkable boron diffusion occurred in KrF-laser-annealed samples for very short annealing times. Recrystallization of the amorphous silicon layer was slower in green-laser-annealed samples than in KrF-laser-annealed samples. We consider the penetration depth and the pulse duration are important factors that may affect boron diffusion. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. In-place thermal annealing of nuclear reactor pressure vessels

    International Nuclear Information System (INIS)

    Server, W.L.

    1985-04-01

    Radiation embrittlement of ferritic pressure vessel steels increases the ductile-brittle transition temperature and decreases the upper shelf level of toughness as measured by Charpy impact tests. A thermal anneal cycle well above the normal operating temperature of the vessel can restore most of the original Charpy V-notch energy properties. The Amry SM-1A test reactor vessel was wet annealed in 1967 at less than 343 0 C (650 0 F), and wet annealing of the Belgian BR-3 reactor vessel at 343 0 C (650 0 F) has recently taken place. An industry survey indicates that dry annealing a reactor vessel in-place at temperatures as high as 454 0 C (850 0 F) is feasible, but solvable engineering problems do exist. Economic considerations have not been totally evaluated in assessing the cost-effectiveness of in-place annealing of commercial nuclear vessels. An American Society for Testing and Materials (ASTM) task group is upgrading and revising guide ASTM E 509-74 with emphasis on the materials and surveillance aspects of annealing rather than system engineering problems. System safety issues are the province of organizations other than ASTM (e.g., the American Society of Mechanical Engineers Boiler and Pressure Vessel Code body)

  4. Impact of high temperature and short period annealing on SnS films deposited by E-beam evaporation

    International Nuclear Information System (INIS)

    Gedi, Sreedevi; Reddy, Vasudeva Reddy Minnam; Kang, Jeong-yoon; Jeon, Chan-Wook

    2017-01-01

    Highlights: • Preparation SnS films using electron beam evaporation at room temperature. • SnS films were annealed at a high temperaure for different short period of times. • The films showed highly oriented (111) planes with orthorhombic crystal structure. • Surface morphology showed bigger and faceted grains embedded in orthorombic. • The TEM confirmed that big orthorombic slabs had single-crystalline nature. - Abstract: Thin films of SnS were deposited on Mo-substrate using electron beam evaporation at room temperature. As-deposited SnS films were annealed at a constant high temperaure of 860 K for different short period of times, 1 min, 3 min, and 5 min. The impact of heat treatment period on the physical properties of SnS films was investigated using appropriate characterization tools. XRD analysis revealed that the films were highly oriented along (111) plane with orthorhombic crystal structure. Surface morphology of as-deposited SnS films showed an identical leaf texture where as the annealed films showed large orthorombic slab shape grains in adidition to the leaf shape grains, which indicates the significance of short period annealing at high temperature. The transmission electron microscopy confirmed that those large orthorombic slabs had single-crystalline nature. The results emphasized that the short period annealing treatment at high temperature stimulated the growth of film towards the single crystallinity.

  5. Impact of high temperature and short period annealing on SnS films deposited by E-beam evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Gedi, Sreedevi; Reddy, Vasudeva Reddy Minnam; Kang, Jeong-yoon; Jeon, Chan-Wook, E-mail: cwjeon@ynu.ac.kr

    2017-04-30

    Highlights: • Preparation SnS films using electron beam evaporation at room temperature. • SnS films were annealed at a high temperaure for different short period of times. • The films showed highly oriented (111) planes with orthorhombic crystal structure. • Surface morphology showed bigger and faceted grains embedded in orthorombic. • The TEM confirmed that big orthorombic slabs had single-crystalline nature. - Abstract: Thin films of SnS were deposited on Mo-substrate using electron beam evaporation at room temperature. As-deposited SnS films were annealed at a constant high temperaure of 860 K for different short period of times, 1 min, 3 min, and 5 min. The impact of heat treatment period on the physical properties of SnS films was investigated using appropriate characterization tools. XRD analysis revealed that the films were highly oriented along (111) plane with orthorhombic crystal structure. Surface morphology of as-deposited SnS films showed an identical leaf texture where as the annealed films showed large orthorombic slab shape grains in adidition to the leaf shape grains, which indicates the significance of short period annealing at high temperature. The transmission electron microscopy confirmed that those large orthorombic slabs had single-crystalline nature. The results emphasized that the short period annealing treatment at high temperature stimulated the growth of film towards the single crystallinity.

  6. Chemical effects of (n, γ) nuclear reaction on (Mo6Cl8)Cl4

    International Nuclear Information System (INIS)

    Fucugauchi, L.A.; Millan, S.; Mondragon, A.; Solache-Rios, M.

    1994-01-01

    The chemical effects of 98 Mo(n, γ) 99 Mo reaction on molybdenum(II) chloride [(Mo 6 Cl 8 )Cl 4 ] have been studied. Retention, thermal and radiolytical annealing were determined. It was found that this molybdenum compound has low retention, a negligible tendency to thermal annealing and a virtual insensitivity to hydrolysis. For practical applications in the enrichment of 99 Mo by the Shilard-Chalmers method, molybdenum(II) chloride [(Mo 6 Cl 8 )Cl 4 ] appears to offer good prospects. (author) 14 refs.; 2 figs

  7. Strain relaxation near high-k/Si interface by post-deposition annealing

    International Nuclear Information System (INIS)

    Emoto, T.; Akimoto, K.; Yoshida, Y.; Ichimiya, A.; Nabatame, T.; Toriumi, A.

    2005-01-01

    We studied the effect of post-deposition annealing on a HfO 2 /Si interface of by extremely asymmetric X-ray diffraction. Comparing the rocking curves before annealing the sample with those of the annealed sample, it is found that an interfacial layer with a density of 3 g/cm 3 grows at the interface between the HfO 2 layer and the substrate during post-deposition annealing. The wavelength dependency of the integrated intensities of the rocking curve for the as-deposited sample fluctuated with the observation position. This fluctuation was suppressed by annealing. From these results we concluded that the strain introduced into the substrate becomes homogeneous by annealing. Moreover, a quantitative estimation of the strain by curve fitting reveals the existence of compressive strain under the HfO 2 layer

  8. On lumped models for thermodynamic properties of simulated annealing problems

    International Nuclear Information System (INIS)

    Andresen, B.; Pedersen, J.M.; Salamon, P.; Hoffmann, K.H.; Mosegaard, K.; Nulton, J.

    1987-01-01

    The paper describes a new method for the estimation of thermodynamic properties for simulated annealing problems using data obtained during a simulated annealing run. The method works by estimating energy-to-energy transition probabilities and is well adapted to simulations such as simulated annealing, in which the system is never in equilibrium. (orig.)

  9. The changes of ADI structure during high temperature annealing

    OpenAIRE

    A. Krzyńska; M. Kaczorowski

    2010-01-01

    The results of structure investigations of ADI during it was annealing at elevated temperature are presented. Ductile iron austempered at temperature 325oC was then isothermally annealed 360 minutes at temperature 400, 450, 500 and 550oC. The structure investigations showed that annealing at these temperatures caused substantial structure changes and thus essential hardness decrease, which is most useful property of ADI from point of view its practical application. Degradation advance of the ...

  10. Melting phenomenon and laser annealing in semiconductors

    International Nuclear Information System (INIS)

    Narayan, J.

    1981-03-01

    The work on annealing of displacement damage, dissolution of boron precipitates, and the broadening of dopant profiles in semiconductors after treating with ruby and dye laser pulses is reviewed in order to provide convincing evidence for the melting phenomenon and illustrate the mechanism associated with laser annealing. The nature of the solid-liquid interface and the interface instability during rapid solidification is considered in detail. It is shown that solute concentrations after pulsed laser annealing can far exceed retrograde maxima values. However, there is a critical solute concentration above which a planar solid-liquid interface becomes unstable and breaks into a cellular structure. The solute concentrations and cell sizes associated with this instability are calculated using a perturbation theory, and compared with experimental results

  11. Microstructural evaluation of Ti-35Nb-7,5 T alloy deformed by cold rolling and annealed

    International Nuclear Information System (INIS)

    Giudice, M.L.C.; Hayama, A.O.F.; Button, S.T.; Caram, R.

    2010-01-01

    This work presents the main results of microstructural characterization of Ti- 35Nb-7.5Ta (% in weight) deformed by cold rolling and annealed. Samples were obtained by electric arc melting, heat treated at 1000 deg C for 8 hours and water quenched. Samples were deformed by cold rolling in multiple passes up to a maximum reduction of 84%. Deformed samples were encapsulated in quartz under vacuum and annealed at 600, 700 e 800 deg C, in variable times and water quenched. Characterization was carried out using light optical microscopy, X-ray diffraction, Vickers hardness test and acoustic emission measurements to determine the Young's modulus. The results show the orientation occurrence of the martensitic phase in relation to the cold rolling direction in deformed samples. In samples annealed at 600 deg C recovery is predominant and samples annealed at 800 deg C for 60 min are fully recrystallized. (author)

  12. Strain of laser annealed silicon surfaces

    Science.gov (United States)

    Nemanich, R. J.; Haneman, D.

    1982-05-01

    High resolution Raman scattering measurements have been carried out on pulse and continuous-wave laser annealed silicon samples with various surface preparations. These included polished and ion-bombarded wafers, and saw-cut crystals. The pulse annealing treatments were carried out in ultrahigh vacuum and in air. The residual strain was inferred from the frequency shift of the first-order Raman active mode of Si, and was detectable in the range 10-2-10-3 in all except the polished samples.

  13. Annealing of ion implanted silicon

    International Nuclear Information System (INIS)

    Chivers, D.; Smith, B.J.; Stephen, J.; Fisher, M.

    1980-09-01

    The newer uses of ion implantation require a higher dose rate. This has led to the introduction of high beam current implanters; the wafers move in front of a stationary beam to give a scanning effect. This can lead to non-uniform heating of the wafer. Variations in the sheet resistance of the layers can be very non-uniform following thermal annealing. Non-uniformity in the effective doping both over a single wafer and from one wafer to another, can affect the usefulness of ion implantation in high dose rate applications. Experiments to determine the extent of non-uniformity in sheet resistance, and to see if it is correlated to the annealing scheme have been carried out. Details of the implantation parameters are given. It was found that best results were obtained when layers were annealed at the maximum possible temperature. For arsenic, phosphorus and antimony layers, improvements were observed up to 1200 0 C and boron up to 950 0 C. Usually, it is best to heat the layer directly to the maximum temperature to produce the most uniform layer; with phosphorus layers however it is better to pre-heat to 1050 0 C. (U.K.)

  14. Effects of thermal annealing on electrical characteristics of Cd/CdS/n-Si/Au-Sb sandwich structure

    International Nuclear Information System (INIS)

    Saglam, M.; Ates, A.; Guezeldir, B.; Astam, A.; Yildirim, M.A.

    2009-01-01

    In general, at the metal-semiconductor contacts, interfacial layers have been fabricated by different methods such as molecular beam epitaxy, metal organic chemical vapor deposition, sputtering and vacuum evaporation. However, all of these techniques have encountered various difficulties in the deposited films. Instead of these methods, since Successive Ionic Layer Adsorption and Reaction (SILAR) method is simple, fast, sensitive, and less costly to prepare interfacial layer, we have first employed this method in order to prepare Cd/CdS/n-Si/Au-Sb sandwich structure. For this reason, the CdS thin film has been directly formed on n-type Si substrate by means of SILAR method. The Cd/CdS/n-Si/Au-Sb sandwich structure has demonstrated clearly rectifying behaviour by the current-voltage (I-V) curves studied at room temperature. In order to observe the effect of the thermal annealing, this structure has been annealed at temperatures from 50 to 300 deg. C for 3 min in N 2 atmosphere. The characteristic parameters such as barrier height, ideality factor and series resistance of this structure have been calculated from the forward bias I-V characteristics as a function of annealing temperature with different methods. The values of n, Φ b and mean R s of the initial Cd/CdS/n-Si/Au-Sb sandwich structure were found to be 2.31, 0.790 eV and 1.86 kΩ respectively. After annealing at 300 deg. C, these values were changed to 1.89, 0.765 eV and 0.48 kΩ. It has been seen that the barrier height, ideality factor and series resistance have slightly changed with increasing annealing temperature up to 300 deg. C.

  15. Vestibular stimulation after head injury: effect on reaction times and motor speech parameters

    DEFF Research Database (Denmark)

    Engberg, A

    1989-01-01

    Earlier studies by other authors indicate that vestibular stimulation may improve attention and dysarthria in head injured patients. In the present study of five severely head injured patients and five controls, the effect of vestibular stimulation on reaction times (reflecting attention) and some...... motor speech parameters (reflecting dysarthria) was investigated. After eight weeks with regular stimulation, it was concluded that reaction time changes were individual and consistent for a given subject. Only occasionally were they shortened after stimulation. However, reaction time was lengthened...... in three cases, prohibiting further stimulation in one case. Motion sickness was prohibitive in a second case. However, after-stimulation increase of phonation time and/or vital capacity was found in one patient and four controls. Oral diadochokinetic rates were slowed in several cases. Collectively, when...

  16. Thermal Annealing Reduces Geminate Recombination in TQ1:N2200 All-Polymer Solar Cells

    KAUST Repository

    Karuthedath, Safakath

    2018-03-27

    A combination of steady-state and time-resolved spectroscopic measurements is used to investigate the photophysics of the all-polymer bulk heterojunction system TQ1:N2200. Upon thermal annealing a doubling of the external quantum efficiency and an improved fill factor (FF) is observed, resulting in an increase in the power conversion efficiency. Carrier extraction is similar for both blends, as demonstrated by time-resolved electric-field-induced second harmonic generation experiments in conjunction with transient photocurrent studies, spanning the ps-µs time range. Complementary transient absorption spectroscopy measurements reveal that the different quantum efficiencies originate from differences in charge carrier separation and recombination at the polymer-polymer interface: in as-spun samples ~35 % of the charges are bound in interfacial charge-transfer states and recombine geminately, while this pool is reduced to ~7 % in thermally-annealed sample, resulting in higher short-circuit currents. Time-delayed collection field experiments demonstrate a field-dependent charge generation process in as-spun samples, which reduces the FF. In contrast, field-dependence of charge generation is weak in annealed films. While both devices exhibit significant non-geminate recombination competing with charge extraction, causing low FFs, our results demonstrate that the donor/acceptor interface in all-polymer solar cells can be favourably altered to enhance charge separation, without compromising charge transport and extraction.

  17. Kinetics of Solute Partitioning During Intercritical Annealing of a Medium-Mn Steel

    Science.gov (United States)

    Kamoutsi, H.; Gioti, E.; Haidemenopoulos, Gregory N.; Cai, Z.; Ding, H.

    2015-11-01

    The evolution of austenite fraction and solute partitioning (Mn, Al, and C) during intercritical annealing was calculated for a medium-Mn steel containing 11 pct Mn. Austenite growth takes place in three stages. The first stage is growth under non-partitioning local equilibrium (NPLE) controlled by carbon diffusion in ferrite. The second stage is growth under partitioning local equilibrium (PLE) controlled by diffusion of Mn in ferrite. The third stage is shrinkage of austenite under PLE controlled by diffusion of Mn in austenite. During PLE growth, the austenite is progressively enriched in Mn. Compositional spikes evolve early during NPLE growth and broaden with annealing temperature and time.

  18. One step synthesis of chlorine-free Pt/Nitrogen-doped graphene composite for oxygen reduction reaction

    KAUST Repository

    Varga, Tamá s; Varga, Á gnes Tí mea; Ballai, Gergő; Haspel, Henrik; Kukovecz, Á kos; Kó nya, Z.

    2018-01-01

    Chlorine-free Platinum/nitrogen-doped graphene oxygen reduction reaction catalysts were synthesized by a one step method of annealing a mixture of platinum acetylacetonate and graphene oxide under ammonia atmosphere. Nanoparticles with close

  19. The effects of reactants ratios, reaction temperatures and times on Maillard reaction products of the L-ascorbic acid/L-glutamic acid system

    Directory of Open Access Journals (Sweden)

    Yong-Yan ZHOU

    2016-01-01

    Full Text Available Abstract The transformation law of the Maillard reaction products with three different reactants ratios - equimolar reactants, excess L-glutamic acid and excess L-ascorbic acid reaction respectively, five different temperatures, and different time conditions for the L-ascorbic acid / L-glutamic acid system were investigated. Results showed that, the increase of the reaction time and temperature led to the increase of the browning products, uncoloured intermediate products, as well as aroma compounds. Compared with the equimolar reaction system, the excess L-ascorbic acid reaction system produced more browning products and uncoloured intermediate products, while the aroma compounds production remained the same. In the excess L-glutamic acid system, the uncoloured intermediate products increased slightly, the browning products remained the same, while the aroma compounds increased.

  20. Contribution to implanted silicon layers and their annealing

    International Nuclear Information System (INIS)

    Combasson, J.-L.

    1976-01-01

    Defects created by boron implantation in silicon have been characterized by measuring the diffusion coefficient during annealing. Implanted impurity distributions were calculated after analyzing the hypotheses relating to charged particle slowing down through matter. Profiles are predicted with a good accuracy, by replacing occasionally the electronic stopping law by an empirical law. The asymmetries predicted are generally observed but deviations may occur for crystalline targets, or when the ion is heavy with regard to the substrate (in the event the Thomas-Fermi potential is not yet valid due to the high impact parameters). When deviations are neglected, the displacement cascade from implantation is represented by a damage profile proportional to the distribution of the Frenkel pairs. The annealing of the implanted layers is characterized by three annealing stages. The first one (400 deg C-600 deg C) is imputed to divacancy annealing associated to the formation and migration of boron-vacancy complexes. The second one (500 deg C-650 deg C) is characterized by the Watkins replacement mechanism. At high temperatures, when the annealing duration is longer than that of precipitation, interstitial loops are dissolved, and the thermal diffusion of boron atoms involves the vacancy mechanism of thermal diffusion [fr