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Sample records for low-level 63ni activity

  1. National Low-Level Waste Management Program Radionuclide Report Series. Volume 10, Nickel-63

    International Nuclear Information System (INIS)

    Carboneau, M.L.; Adams, J.P.

    1995-02-01

    This report outlines the basic radiological, chemical, and physical characteristics of nickel-63 ( 63 Ni) and examines how these characteristics affect the behavior of 63 Ni in various environmental media, such as soils, groundwater, plants, animals, the atmosphere, and the human body. Discussions also include methods of 63 Ni production, waste types, and waste forms that contain 63 Ni. The primary source of 63 Ni in the environment has been low-level radioactive waste material generated as a result of neutron activation of stable 62 Ni that is present in the structural components of nuclear reactor vessels. 63 Ni enters the environment from the dismantling activities associated with nuclear reactor decommissioning. However, small amounts of 63 Ni have been detected in the environment following the testing of thermonuclear weapons in the South Pacific. Concentrations as high as 2.7 Bq a per gram of sample (or equivalently 0.0022 parts per billion) were observed on Bikini Atoll (May 1954). 63 Ni was not created as a fission product species (e.g., from 235 U or 239 Pu fissions), but instead was produced as a result of neutron capture in 63 Ni, a common nickel isotope present in the stainless steel components of nuclear weapons (e.g., stainless-304 contains ∼9% total Ni or ∼0.3% 63 Ni)

  2. National Low-Level Waste Management Program Radionuclide Report Series. Volume 10, Nickel-63

    Energy Technology Data Exchange (ETDEWEB)

    Carboneau, M.L.; Adams, J.P.

    1995-02-01

    This report outlines the basic radiological, chemical, and physical characteristics of nickel-63 ({sup 63}Ni) and examines how these characteristics affect the behavior of {sup 63}Ni in various environmental media, such as soils, groundwater, plants, animals, the atmosphere, and the human body. Discussions also include methods of {sup 63}Ni production, waste types, and waste forms that contain {sup 63}Ni. The primary source of {sup 63}Ni in the environment has been low-level radioactive waste material generated as a result of neutron activation of stable {sup 62}Ni that is present in the structural components of nuclear reactor vessels. {sup 63}Ni enters the environment from the dismantling activities associated with nuclear reactor decommissioning. However, small amounts of {sup 63}Ni have been detected in the environment following the testing of thermonuclear weapons in the South Pacific. Concentrations as high as 2.7 Bq{sup a} per gram of sample (or equivalently 0.0022 parts per billion) were observed on Bikini Atoll (May 1954). {sup 63}Ni was not created as a fission product species (e.g., from {sup 235}U or {sup 239}Pu fissions), but instead was produced as a result of neutron capture in {sup 63}Ni, a common nickel isotope present in the stainless steel components of nuclear weapons (e.g., stainless-304 contains {approximately}9% total Ni or {approximately}0.3% {sup 63}Ni).

  3. Radiochemical method for 63Ni

    International Nuclear Information System (INIS)

    Holm, E.; Nilsson, U.; Hallstadius, L.

    1985-01-01

    A radianalytical method for the determination of 63 Ni content in environmental samples of activated corrosion products is described. After chemical separation and electrodepositing of 63 Ni on silver briquets, the chemical yield is determined by X-ray fluorescence analysis. For the detection of low-energy beta activity, an open gas flow GM-counter with an anticoincidence guard counter is put to use

  4. Chemical yield determination for 59Ni, 63Ni and 56Fe in low and intermediate nuclear wastes by ICP-AES

    International Nuclear Information System (INIS)

    Franco, Milton B.; Santos Neto, Francisco C. dos; Reis Junior, Aluisio S.; Temba, Eliane S.C.; Monteiro, Roberto P.G.

    2011-01-01

    Iron and nickel are constituents of a wide range of metallic materials used in nuclear reactor construction and their corresponding activation products are often encountered in reactor-derived solid low and intermediate-level wastes. The most significant radioisotopes of iron and nickel, in terms of quantity and half life, are 55 Fe (t 1/2 =2.73y), 59 Ni (t 1/2 =7.6x10 4 y) and 63 Ni (t 1/2 =10 2 y) and they are activation products of stable iron and nickel. 59 Ni is an X-ray - emitting and 55 Fe and 63 Ni are β-particle-emitting radionuclides and so they are radionuclides of interest for the performance of assessment studies of waste storage or disposal. For their determination in the radioactive wastes is necessary to know the chemical yield for the radiochemical separation procedures prior analytical measurements. In this work Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) technique was used for this aim. Total nickel and iron in waste samples from nuclear power plants were determined before and after the radiochemical separation at specific wavelengths, 231.604 nm and 259.940 nm respectively. The chemical yields for nickel and iron recovery were around 82 % for iron and 59 % for nickel according the analytical methodology adopted. (author)

  5. The process of Ni-63 production and measurement of beta radiation of irradiated Ni-63

    International Nuclear Information System (INIS)

    Kim, Jin Joo; Uhma, Young Rang; Kim, Jong Bum; Choi, Sang Mu; Son, Kwang Jae; Hong, Jin Tae; Park, Jong Han

    2016-01-01

    It has the following characteristics: long service lifetime, high energy density, easy small-scale fabrication, and minimum maintenance. For this reasons, betavoltaic batteries are widely used in many low-power applications such as medical applications and power sources for micro electro-mechanical system (MEMS) because they can operate effectively at extreme environments. Proper selection of radioisotope is a critical factor in the design of a betavoltaic battery. The important factors affecting the performance of a betavoltaic battery are specific activity, half-life, and toxicity. In this study, a target for irradiation was produced using 99% Ni-62 metal power concentrate. Ni-62 target of 1 g was irradiated in MARIA reactor operated in Poland for 470 hours, and estimated production of Ni- 63 was calculated. Irradiated Ni-63 pellets were dissolved in HCl solution, and its beta radiation was measured by Liquid Scintillation Counter (LSC).

  6. Activation measurements for fast neutrons. Part D. Evaluation of cosmic-ray-induced 63Ni background in copper

    International Nuclear Information System (INIS)

    Ruehm, Werner; Rugel, Georg; Faestermann, Thomas

    2005-01-01

    As a result of a joint collaboration between the University of Utah, LLNL, the Technical University Munich and the Ludwig Maximilians University Munich, it became possible to determine A-bomb induced 63 Ni in pure copper samples from Hiroshima beyond a ground range of 1,000 m (see Chapter 9, Part B). The low 63 Ni activities induced in copper samples due to neutrons from the A-bomb explosion at large distance require, however, a careful discussion of the fraction of 63 Ni produced in these samples due to cosmic radiation. In this section, an analysis of the production of 63 Ni in copper samples due to cosmic radiation is performed. Production due to neutrons, protons, stopped muons, and photonuclear reactions is discussed. It is obvious from Figure 1 (Pfennig et al. 1995) that a variety of reactions induced by neutrons, protons, muons and photons can contribute to the production of 63 Ni in copper. The most important of these processes will be discussed here. Since the cross-sections for the production of 63 Ni in copper samples due to fast and stopped muons were not known, they were determined experimentally. (J.P.N.)

  7. A comparative study using liquid scintillation counting to determine 63Ni in low and intermediate level radioactive waste

    International Nuclear Information System (INIS)

    Gautier, Celine; Colin, Christele; Garcia, Cecile

    2016-01-01

    A comparative study using liquid scintillation counting was performed to measure 63 Ni in low and intermediate level radioactive waste. Three dimethylglyoxime (DMG)-based radiochemical procedures (solvent extraction, precipitation, extraction chromatography) were investigated, the solvent extraction method being considered as the reference method. Theoretical speciation calculations enabled to better understand the chemical reactions involved in the three protocols and to optimize them. In comparison to the method based on DMG precipitation, the method based on extraction chromatography allowed to achieve the best results in one single step in term of recovery yield and accuracy for various samples. (author)

  8. Validation of a method for the determination of 14C and 63Ni activity in concrete matrices

    International Nuclear Information System (INIS)

    Rosskopfova, Olga; Galambos, Michal; Pupak, Matus

    2010-01-01

    Simple and reliable methods were developed for the determination of 14 C and 63 Ni activity in concrete by using a low-background liquid scintillation counter. Direct CO 2 absorption was used in the determination of 14 C whereas extraction chromatography on a Nickel Resin column (Eichrom) served to determine 63 Ni. The methods were validated by engagement in the Environmental Radioactivity Proficiency Test Exercise 2008, complying with ISO/IEC 17025:2005

  9. Activation measurements for fast neutrons. Part B. 63Ni measurements by accelerator mass spectrometry (AMS)

    International Nuclear Information System (INIS)

    Straume, Tore; Rugel, Georg; Marchetti, Alfredo A.

    2005-01-01

    The AMS-measurements of 63 Ni in copper samples obtained from different distances in Hiroshima represent the first detection of fast neutrons after more than 50 years, and the first reliable bomb-induced fast neutron measurements beyond 700 m from the hypocenter. A major significance of these 63 Ni results is that they provide, for the first time, fast neutron measurements at the distances most relevant to atomic-bomb survivor locations (900-1,500 m). The measurement of 63 Ni in copper samples using AMS provides a substantial improvement in fast neutron detection compared with the 32 P measurements made in 1945. For example, the measurement-to-background ratio at about 400 m from the hypocenter is about 55 for 63 Ni and only about 2 for the 32 P measurements. Also, the 63 Ni measurements reach background levels at about 1,800 m from the hypocenter compared with only about 700 m for 32 P. At distances of ∼1,800 m from the hypocenter, out to at least 5,000 meters, the measurements appear to level off at a value on the order of 7x10 4 atoms of 63 Ni/g of Cu, suggesting a background of approximately that magnitude. When this background is subtracted and the resulting data corrected to 1945, the measured 63 Ni in copper samples from Hiroshima are in good agreement with DS02 sample-specific calculations. Comparisons with DS86 calculations also show good agreement except at the Bank of Japan. The difference at that distance is significant when compared with DS86 calculations. (J.P.N.)

  10. Radioactive 63Ni in biological research

    International Nuclear Information System (INIS)

    Kasprzak, K.S.; Sunderman, F.W. Jr.

    1979-01-01

    Applications of 63 Ni in biological research are reviewed, with emphasis upon recent investigations of nickel metabolism and toxicology in experimental animals. The radiochemistry of 63 Ni is summarized, including consideration of the preparation of certain 63 Ni compounds (e.g. 63 Ni(CO) 4 and 63 Ni 3 S 2 ) that are of current interest in toxicology, teratology and cancer research. Practical guidance is given regarding the detection and determination of 63 Ni in biological materials by autoradiography and liquid scintillation spectrometry. (author)

  11. Separation and radiometric determination of 59Ni, 63Ni, 55Fe, 99Tc and 94Nb in radioactive wastes of low and intermediate activities from PWR nuclear power plants

    International Nuclear Information System (INIS)

    Temba, Eliane Silvia Codo

    2016-01-01

    The objective of this work was the development and establishment of a specific analytical protocol for the determination of the 59 Ni, 63 Ni, 55 Fe, 99 Tc and 94 Nb radionuclides in low and intermediate radioactive waste samples of Almirante Alvaro Alberto Nuclear Power Plant, CNAAA, located in the city of Angra dos Reis, RJ. The separation and purification techniques used have taken into account the particularities of each radionuclide studied. Chemical separation methods were used, as well as carriers and radioisotope tracers, and ion-exchange and extraction chromatography involving specific resins. The main techniques used for the analysis and determination of the radionuclides were Liquid Scintillation Counting (LSC) and Gamma Spectrometry. Also used were Atomic Emission Spectroscopy with Inductively Coupled Plasma (ICP-AES) and Neutron Activation Analysis (NAA) for the chemical yield determination. Concerning to the 59 Ni, 63 Ni, 55 Fe radionuclides, the methodology of sequential separation proved to be very appropriate for their separation and determination, as could be observed by the results obtained. Chemical yields in the range from 39 to 100%, and LSC counting efficiencies in the range of 37.8% for 55 Fe, and 71.5% for 63 Ni, are in accordance with the results found in the literature. The spectra of LSC showed that the methodology used to separation and purification of these radionuclides was very successful. The results for 59 Ni have shown that the use of a 55 Fe certified standard for calibration of the equipment was a viable alternative. In the case of the 99 Tc radionuclide the use of rhenium as carrier and chemical yield monitor, resulted in high chemical yields. Use of Gamma Spectrometry analysis made it possible to check that the main interfering agents were actually removed with the combined use of anion exchange chromatography and TEVA resin. The chemical yield of 94 Nb was measured by Gamma Spectrometry analysis of the 94 mNb nuclide formed by

  12. Neutron-induced {sup 63}Ni activity and microscopic observation of copper samples exposed to the Hiroshima atomic bomb

    Energy Technology Data Exchange (ETDEWEB)

    Shizuma, Kiyoshi, E-mail: shizuma@hiroshima-u.ac.jp [Quantum Energy Applications, Department of Mechanical Science and Engineering, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527 (Japan); Endo, Satoru [Quantum Energy Applications, Department of Mechanical Science and Engineering, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527 (Japan); Shinozaki, Kenji [Materials Joining Science and Engineering, Department of Mechanical Science and Engineering, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527 (Japan); Fukushima, Hiroshi [Materials Physics, Department of Mechanical Science and Engineering, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527 (Japan)

    2013-05-01

    Fast neutron activation data for {sup 63}Ni in copper samples exposed to the Hiroshima atomic bomb are important in evaluating neutron doses to the survivors. Up to until now, accelerator mass spectrometry and liquid scintillation counting methods have been applied in {sup 63}Ni measurements and data were accumulated within 1500 m from the hypocenter. The slope of the activation curve versus distance shows reasonable agreement with the calculation result, however, data near the hypocenter are scarce. In the present work, two copper samples obtained from the Atomic bomb dome (155 m from the hypocenter) and the Bank of Japan building (392 m) were utilized in {sup 63}Ni beta-ray measurement with a Si surface barrier detector. Additionally, microscopic observation of the metal surfaces was performed for the first time. Only upper limit of {sup 63}Ni production was obtained for copper sample of the Atomic bomb dome. The result of the {sup 63}Ni measurement for Bank of Japan building show reasonable agreement with the AMS measurement and to fast neutron activation calculations based on the Dosimetry System 2002 (DS02) neutrons.

  13. Study of 63Ni adsorption on NKF-6 zeolite

    International Nuclear Information System (INIS)

    Zhang Hui; Yu Xianjin; Chen Lei; Jing Yongjie; Ge Zhiwei

    2010-01-01

    The adsorption of 63 Ni from aqueous solutions using NKF-6 zeolite was investigated by a batch technique under ambient conditions. The adsorption was investigated as a function of contact time, pH, ionic strength, foreign ions, humic substances (FA/HA) and temperature. The kinetic adsorption was well described by the pseudo-second-order rate equation. The adsorption of 63 Ni on NKF-6 zeolite was strongly dependent on pH and ionic strength, and the adsorption of 63 Ni increased with increasing NKF-6 zeolite content. At low pH values, the presence of FA enhanced the adsorption of 63 Ni on NKF-6 zeolite, but the presence of HA had no drastic effect. At high pH values, the presence of FA or HA decreased the adsorption of 63 Ni on NKF-6 zeolite. The adsorption isotherms were well represented by the Langmuir model. The thermodynamic parameters (i.e., ΔH 0 , ΔS 0 and ΔG 0 ) for the adsorption of 63 Ni were determined from the temperature dependent isotherms at 293.15, 313.15 and 333.15 o K, respectively, and the results indicate that the adsorption reaction was favored at high temperature. The results suggest that the adsorption process of 63 Ni on NKF-6 zeolite is spontaneous and endothermic. - Research highlights: → As an economical and efficient method, adsorption technique has been widely applied in the disposal of wastewaters. The study of 63 Ni on NKF-6 zeolite, especially the thermodynamic data of 63 Ni adsorption on NKF-6 zeolite and the effect of humic substances on 63 Ni uptake to humic-zeolite hybrids, is still scarce. In this paper, the sorption of 63 Ni on NKF-6 zeolite is studied as a function of various environmental conditions such as contact time, pH, ionic strength, foreign ions, humic substances and temperature. Based on the obtained experimental results, the adsorption mechanism of 63 Ni on NKF-6 zeolite is stated in detail. This study will have an important reference value in evaluating the physiochemical behavior of radionuclide 63 Ni.

  14. Development of small-scale electroplating system for Ni-63 electroplating onto Ni foil

    International Nuclear Information System (INIS)

    Kim, Jin Joo; Choi, Sang Mu; Son, Kwang Jae; Hong, Jintae

    2016-01-01

    Betavoltaic battery is a device that converts the decay energy of beta-emitting radioisotopes into electric energy. Ni-63 is pure betaemitter with a low energy spectrum and significantly long half-life of 100.1 years and thus is widely used as the power source of betavoltaic battery. There are several methods for the formation of a Ni deposit onto a semiconductor such as electroplating, electroless plating, and chemical vapor deposition. In this study, small-scale radioisotope electroplating system was designed and fabricated to perform electroplating with a small amount of plating buffer and minimum exposure of radioactive materials. These procedures and the manufactured electroplating device can be applied to radioactive Ni-63 electroplating for the fabrication of a betavoltaic battery. In this study, an electroplating system for small-scale Ni electroplating was designed and manufactured. The process for the fabrication of a Ni-63 foil as the energy source of a betavoltaic battery was developed using the minimum concentration of Ni. These procedures and the manufactured electroplating device can be applied to radioactive Ni-63 electroplating for the fabrication of a betavoltaic battery

  15. Development of small-scale electroplating system for Ni-63 electroplating onto Ni foil

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Joo; Choi, Sang Mu; Son, Kwang Jae; Hong, Jintae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Betavoltaic battery is a device that converts the decay energy of beta-emitting radioisotopes into electric energy. Ni-63 is pure betaemitter with a low energy spectrum and significantly long half-life of 100.1 years and thus is widely used as the power source of betavoltaic battery. There are several methods for the formation of a Ni deposit onto a semiconductor such as electroplating, electroless plating, and chemical vapor deposition. In this study, small-scale radioisotope electroplating system was designed and fabricated to perform electroplating with a small amount of plating buffer and minimum exposure of radioactive materials. These procedures and the manufactured electroplating device can be applied to radioactive Ni-63 electroplating for the fabrication of a betavoltaic battery. In this study, an electroplating system for small-scale Ni electroplating was designed and manufactured. The process for the fabrication of a Ni-63 foil as the energy source of a betavoltaic battery was developed using the minimum concentration of Ni. These procedures and the manufactured electroplating device can be applied to radioactive Ni-63 electroplating for the fabrication of a betavoltaic battery.

  16. Activation measurements for fast neutrons. Part E. Evaluation of fast neutron 63Ni transmission factors

    International Nuclear Information System (INIS)

    Egbert, Stephen D.

    2005-01-01

    The 63 Ni measurements for fast neutrons in copper samples are compared to the calculated free-in-air 63 Ni neutron activation given in Chapter 3 by use of transmission factors. Transmission factors were calculated to account for the modification of the fluence and activation at each sample's in situ location. For the purposes of this discussion, the transmission factor (TF) is defined as the ratio of the in situ sample activation divided by the untilted free-in-air (FIA) activation at a height of 1 m above ground at the same ground range. Examples of the application of TF's will be provided in this section. (author)

  17. Synthesis of electroplated 63Ni source and betavoltaic battery

    International Nuclear Information System (INIS)

    Uhm, Young Rang; Yoo, Kwon Mo; Choi, Sang Mu; Kim, Jin Joo; Son, Kwang Jae

    2015-01-01

    Radioisotope (Nuclear) battery using 63 Ni was prepared as beta cell. The electroplated 63 Ni on Ni foil is fabricated, and beta cell and photovoltaic hybrid battery was designed to use at both day and night in space project. A Ni-plating solution is prepared by dissolving metal particles including 62 Ni and 63 Ni from neutron irradiation of (n,γ). Electroplating solution of a chloride bath consists on nickel ions in HCl, H 3 BO 3 , and KOH. The deposition was carried out at current density of 10 mA cm -2 . The prepared beta source was attached on a PN junction and measured I-V properties. The power output at activity of 0.07 mCi and 0.45 mCi were 0.55 pW and 2.69 nW, respectively

  18. Flowsheet for 63Ni production

    International Nuclear Information System (INIS)

    Williams, D.F.; Knauer, J.B.; O'Kelley, G.D.; Wiggins, J.T.; Porter, C.E.

    1992-01-01

    The production of large quantities of high specific activity 63 Ni (>10Ci/g) requires both a highly enriched 62 Ni target and a long irradiation period at high neutron flux. Trace impurities in the nickel and associated target materials are also activated and account for a significant fraction of the discharged activity and essentially all of the gamma activity. While most of these undesirable activation products (mainly transition metals) can be easily removed as chloride complexes during anion exchange, chromium, present as 51 Cr, and manganese, present as 54 Mn, are exceptions and require solvent extraction of the in-cell product to achieve the desired purity. In addition to summarizing the current development and production experience, optimized flowsheets are discussed

  19. Synthesis of electroplated {sup 63}Ni source and betavoltaic battery

    Energy Technology Data Exchange (ETDEWEB)

    Uhm, Young Rang; Yoo, Kwon Mo; Choi, Sang Mu; Kim, Jin Joo; Son, Kwang Jae [Radioisotope Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-12-15

    Radioisotope (Nuclear) battery using {sup 63}Ni was prepared as beta cell. The electroplated {sup 63}Ni on Ni foil is fabricated, and beta cell and photovoltaic hybrid battery was designed to use at both day and night in space project. A Ni-plating solution is prepared by dissolving metal particles including {sup 62}Ni and {sup 63}Ni from neutron irradiation of (n,γ). Electroplating solution of a chloride bath consists on nickel ions in HCl, H{sub 3}BO{sub 3}, and KOH. The deposition was carried out at current density of 10 mA cm{sup -2}. The prepared beta source was attached on a PN junction and measured I-V properties. The power output at activity of 0.07 mCi and 0.45 mCi were 0.55 pW and 2.69 nW, respectively.

  20. Selection of optimum ROI for dual radionuclide analysis of 55Fe-63Ni and 63Ni-60Co

    International Nuclear Information System (INIS)

    Priya, S.; Prabhath Ravi, K.; Yadav, R.K.B.; Rao, D.D.; Gopalakrishnan, R.K.

    2016-01-01

    Dual label counting in liquid scintillation counting (LSC) enables simultaneous activity determination of two radionuclides. Dual counting procedure for 3 H and 14 C has been well established. There are several other nuclides like 63 Ni (E β- =67keV), 55 Fe (6 keV X-ray and auger electron) which are often chemically separated using detailed procedures with high decontamination factors (DF) and quantified using LSC. Despite the laborious separations, traces of these nuclides in the chemically separated fractions can mutually make their quantification difficult due to overlap of counts from both radionuclides in the spectrum, which gets further complicated in presence of traces of 60 Co. For dual label counting technique, it is essential to establish the discriminator setting at which there will be spillover of counts from both radionuclides in the two counting regions required for the inclusion method. The objective of the current work is to establish two counting ROI's for dual counting of (i) 63 Ni- 55 Fe and (ii) 63 Ni- 60 Co in a TDCR based LSC system

  1. Relationship between {sup 63}Ni and {sup 3}H in an environmental monitoring program for water of a nuclear facility

    Energy Technology Data Exchange (ETDEWEB)

    Idoeta, R.; Herranz, M.; Legarda, F. [Universidad del Pais Vasco UPV/EHU (Spain); De Lucas, M.J. [Medidas Ambientales S.L. (Spain)

    2014-07-01

    During four years deep water coming from twelve different sampling points in the neighborhood of a nuclear facility have been quarterly analyzed for different radionuclides ({sup 63}Ni, {sup 55}Fe, {sup 90}Sr, {sup 14}C, {sup 3}H, {sup 240+239}Pu, {sup 241}Am, {sup 243+244}Cm, gross alpha, gross beta and gamma emitters) and for typical chemical components (pH, Conductivity (25 deg. C), Chlorides, Bicarbonates, Sulfates, Calcium, Magnesium, Sodium and Potassium). Sampling points are well characterized by measuring in situ and in every sampling campaign, its level (m), temperature, depth, pH, conductivity and free oxygen (mg/l). For the determination of alpha and beta specific radionuclides, methods, equipment and measurement parameters were chosen to be able to obtain low detection limits in order to characterize these waters. These detection limits, obtained following the ISO 11929 standard methodology, were around 2E-01 Bq/m{sup 3} for alpha emitters, around 2E+01 Bq/m{sup 3} for {sup 63}Ni, and {sup 55}Fe and around 3E+03 Bq/m{sup 3} for {sup 14}C and {sup 3}H. Despite these low detection limits, only small amounts of {sup 3}H and {sup 63}Ni have been systematically detected in some of these waters. These artificial radionuclides have different origins, being {sup 3}H mainly a tertiary fission product and {sup 63}Ni an activation product. {sup 3}H was determined by distillation followed by liquid scintillation counting (LSC) and {sup 63}Ni was determined by radiochemical isolation using specific Ni-resin, followed also by LSC. In this work, the relationship between {sup 3}H and {sup 63}Ni content values is obtained and analyzed and a multivariate analysis among the chemical water components and its {sup 3}H and {sup 63}Ni contents has been carried out in order to explain the behaviour of these radionuclides and its migration from the facility to the deep waters. Document available in abstract form only. (authors)

  2. Development of 63Ni sources for defence related applications

    International Nuclear Information System (INIS)

    Udhayakumar, J.; Pardeshi, G.S.; Gandhi, Shyamala S.; Dash, A.; Venkatesh, Meera

    2004-01-01

    63 Ni is seen as a good substitute for the conventional sources of ionization used in electron capture detectors in Gas Chromatography applications. It has advantages such as source stability, reasonably long shelf life due to its long half-life and viable for safe and easy handling due to low energy beta emission. At the special request from the Defence Establishments in India for supply of 63 Ni beta source on special dimension of a curved inner copper ring area, the new electro-deposition cell was designed and used for routine preparation and supply of such sources. The paper describes the procedure for fabrication of 63 Ni beta sources by electro-deposition method. Activity up to ∼370 MBq (∼10 mCi) was electrodeposited exclusively on inner curved area of ∼4 sq.cm. Copper annular ring, using Boric acid electrolyte bath solution at a temperature range of 50 deg - 60 deg C with a current density of ∼ 6 ma/sq.cm. For this purpose, a new electro depositing cell was specially designed and used. The paper discusses the details regarding source requirement, source preparation parameters, film thickness and its impact on beta output, source quality control aspects and other applications of the sources. The paper also highlights the demand and supply scenario of such electrodeposited sources, in terms of commercial supply sale value, as an import substitute. (author)

  3. A Simple theoretical model for 63Ni betavoltaic battery

    International Nuclear Information System (INIS)

    ZUO, Guoping; ZHOU, Jianliang; KE, Guotu

    2013-01-01

    A numerical simulation of the energy deposition distribution in semiconductors is performed for 63 Ni beta particles. Results show that the energy deposition distribution exhibits an approximate exponential decay law. A simple theoretical model is developed for 63 Ni betavoltaic battery based on the distribution characteristics. The correctness of the model is validated by two literature experiments. Results show that the theoretical short-circuit current agrees well with the experimental results, and the open-circuit voltage deviates from the experimental results in terms of the influence of the PN junction defects and the simplification of the source. The theoretical model can be applied to 63 Ni and 147 Pm betavoltaic batteries. - Highlights: • The energy deposition distribution is found following an approximate exponential decay law when beta particles emitted from 63 Ni pass through a semiconductor. • A simple theoretical model for 63 Ni betavoltaic battery is constructed based on the exponential decay law. • Theoretical model can be applied to the betavoltaic batteries which radioactive source has a similar energy spectrum with 63 Ni, such as 147 Pm

  4. Automated rapid method for the determination of Ni-63 in deconstruction of nuclear facilities- and environmental samples; Automatisiertes Schnellverfahren zur Bestimmung von Ni-63 in Rueckbau- und Umweltproben

    Energy Technology Data Exchange (ETDEWEB)

    Bach, M.; Flucht, R.; Burow, M.; Zoriy, M.V. [Forschungszentrum Juelich GmbH, Juelich (Germany)

    2012-07-01

    Because of the increasing demand on the deconstruction of nuclear facilities in the last few years, a rapid method for the determination of Ni-63 in environmental samples is required. At Juelich, Division of Safety and Radiation Protection we have established a routine method, based on the determination of Ni-63 in the environmental samples using extraction chromatography separation from 2000[1] and optimize the sample preparation. Samples of different matrices were prepared by wet chemical methods for the extraction chromatography separation. For the separation the samples were introduced manually via a peristaltic pump or by using developed automated separation system equipped with the extraction chromatography column of Ni-Resin. Nickel[2] forms a Dimethylglyoximkomplex (DMG) and can be separated. The activity of the Ni-63 then were measured bei means of liquid scintillation counter (LSC), the recovery was determined using MC-ICP-MS. The yields of the Ni-carrier for the develped procure was higher than 90% with the accuracy below 10%. The developed method allows the relatively simple and fast determination of Ni-63 in environmental samples with a detection limit of 0.1 Bq/l. (orig.)

  5. Determination of Fe-55 and Ni-63 in Environmental Samples. Analytical Problems. Characteristic Limits. Automatized Calculation; Determinacion de 55{sup F}e y 63{sup N}i en Muestras Ambientales. Problemas Analiticos. Limites Caracteristicos. Calculo Automatizado

    Energy Technology Data Exchange (ETDEWEB)

    Gasco, C; Navarro, N; Gonzalez, P; Heras, M C; Gapan, M P; Alonso, C; Calderon, A; Sanchez, D; Morante, R; Fernandez, M; Gajate, A; Alvarez, A

    2008-08-06

    The Department of Vigilance Radiologica y Radiactividad Ambiental from CIEMAT has developed an appropriate analytical methodology for Fe-55 and Ni-63 sequential determination in environmental samples based on the procedure used by RIS0 Laboratories. The experimental results obtained in the mayor and minor elements behaviour (soil and air constituents) in the different types of resins used for separating Fe-55 and Ni-63 are showed in this report. The measuring method of both isotopes by scintillation counting has been optimized with Ultima Gold liquid with different concentrations of stable element Fe and Ni. The decontamination factors of different gamma-emitters are experimentally determined in this method with the presence of soil matrix. The Fe-55 and Ni-63 activity concentrations and their associated uncertainties have been calculated from the counting data and sample preparation. A computer application has been implemented in Visual Basic in excel sheets for: (I) obtaining the counting data from spectrometer and counts in each window, (II) representing graphically the background and sample spectrums, (III) determining the activity concentration and its associated uncertainty and (IV) calculating the characteristic limits using ISO 11929 (2007) with various confidence levels. (Author) 30 refs.

  6. Tracer technique for measuring specific activity of 63 Ni, using 4πβ-γ

    International Nuclear Information System (INIS)

    Iwahara, A.

    1979-01-01

    The specific activity of a 6 3 Ni solution has been measured by an efficiency tracer technique using a 4 π β - γ coincidence system. 6 3 Ni was chosen. Because it's a very low energy pure beta emitter. Due to chemical compatibility and beta spectral shapes, 6 0 Co has been chosen as tracer. In the determination of 6 3 Ni, the specific activity. As the efficiency tracer techniques requires a previous knowledge of tracer activity, this has been measured by a conventional 4 π β -γ coincidence method. (author)

  7. Determination of {sup 90}Sr, {sup 63}Ni and {sup 55}Fe activities by liquid scintillation counting in the environmental samples close to French nuclear power plants located on Loire and Garonne rivers

    Energy Technology Data Exchange (ETDEWEB)

    Rousseau, G.; Mokili, M.B.; Le Roy, C.; Deniau, I. [SUBATECH, IN2P3 (France); Gontier, G.; Boyer, C. [EDF-DPI-DIN-CIDEN (France); Hemidy, P.Y. [EDF-DPN-UNIE-GPRE-IEV (France); Chardon, P. [CNRS/IN2P3 (France)

    2014-07-01

    The protection of the aquatic and terrestrial environment from a wide range of radioactive contaminants released by nuclear industry requires continuous monitoring of radionuclides released into the environment. Specific measurement methods depending of the radionuclide are used to determinate this contribution. A lot of radionuclide can easily be measured at low level by gamma spectrometry, like {sup 137}Cs, {sup 60}Co..., but others like {sup 90}Sr, {sup 63}Ni or {sup 55}Fe require prior specific radiochemical separations. Activity of {sup 90}Sr values in environmental samples are available but only few measurements of {sup 63}Ni and {sup 55}Fe activities have been carried out in samples collected in the environment close to French nuclear power plants located on the Loire and Garonne rivers despite they represent 12% to 24% for {sup 63}Ni activity and <1% for {sup 55}Fe + other minor radionuclides of total activity of their liquid effluent discharges. {sup 90}Sr is not rejected by the liquid effluent discharges of Nuclear Power Plants and can be found in the environmental samples because of thermonuclear test and subsequently after the Chernobyl nuclear power plant accident. Considering the French Nuclear Power Plant located on Loire and Garonne rivers, the determination of {sup 90}Sr, {sup 63}Ni and {sup 55}Fe levels in the environmental samples around French nuclear power plants is carried out to detect the traces of these radionuclides originating from nuclear technology activities. The environment around five French nuclear Power Plants was investigated for 4 years between 2009 and 2014. The radionuclide activities determined by liquid scintillation counting after chemical steps were performed on a large set of various matrix samples likely to be encountered in environmental monitoring as soils, sediments, terrestrial and aquatic bio-indicators. It was found that the mean activity concentration of the most frequently detected was for the radionuclide {sup 90

  8. Different behaviour of 63Ni and 59Fe during absorption in iron-deficient and iron-adequate jejunal rat segments ex vivo

    International Nuclear Information System (INIS)

    Mueller-Fassbender, M.; Elsenhans, B.; McKie, A.T.; Schuemann, K.

    2003-01-01

    Nickel exhibits low oral toxicity. It shares the absorptive pathways for iron, though there are substantial quantitative differences in handling of both metals. To analyse these differences more closely, jejunal segments from iron-deficient and iron-adequate rats were luminally perfused ex vivo with 59 Fe and 63 Ni at six different concentrations (1-500 μmo1/l) under steady state conditions. 59 Fe over-all absorption increased 2.0-4.6-fold in iron-deficiency at luminal concentrations between 1 and 100 μmol/l, while 63 Ni absorption increased to a much lower extent (2.6-fold at 1 μmol/l and 1.5-fold at higher luminal concentrations). Moreover, there was a 5-7-fold higher concentration for 63 Ni in the jejunal tissue than in the absorbate at luminal concentrations above 50 μmol/l which was not observed at 1 μmol 63 Ni/l and not for 59 Fe. 63 Ni tissue load showed a linear and a saturable fraction. In iron-deficiency the saturable 63 Ni fraction increased 4-fold as compared to only 1.5-fold increments for 59 Fe. Moreover, a substantially higher share of 63 Ni was retained in the jejunal tissue at high as compare to low luminal concentrations after perfusion had been continued without luminal radioactivity. This was not found for 59 Fe and suggests a concentration-dependent block of 63 Ni export across the enterocytes' basolateral membrane. To explain these results one may speculate that 63 Ni may bind more tightly to tissue ligands than 59 Fe due to the higher thermodynamic and kinetic stability of nickel complexes. In particular, nickel may bind to a basolateral population of metal carriers and block its own basolateral transfer in a concentration-dependent manner. Tight 63 Ni binding to non-specific jejunal ligands is responsible for the unaltered high linear fraction of jejunal 63 Ni load in iron-deficient and iron-adequate segments. Binding of 63 Ni to food and tissue ligands in the small intestine may, thus, be a likely explanation for the low oral nickel

  9. Electroplating Ni-63 metal ions in chloride bath on the Cu-plate

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Kwon Mo; Uhm, Young Rang; Son, Kwang Jae; Park, Keun Yung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Ni-63 plating is similar to other electroplating processes that employ soluble metal anodes. The nickel plating solution described by Watts in 1916 eventually replaced all other strategies in use up to that time. Charged Ni ions are formed by sulfate, sulfamate, chloride, and a Watts bath. However, charged Ni-63 ions are formed by dissolving metal Ni-63. Specifically, it requires the passage of direct current (DC) between two electrodes that are immersed in a conductive, aqueous solution of nickel salts. The flow of a DC causes one of the electrodes (the anode) to dissolve and the other electrode (the cathode) to become covered with nickel. The nickel in the solution is present in the form of divalent positively charged ions (Ni{sup 2+}). When the current flows, the positive ions react with two electrons (2e{sup -}) and are converted into metallic nickel (Ni{sup 0}) at the cathode surface. In the present study, we optimize and established process for the electroplating Ni-63 on Cu-plate. Nanocrystalline nickel (Ni) coatings were synthesized by DC electro deposition at a current density of 15 mA/cm{sup 2}. The bath was primarily composed of 0.2 M Ni ions, prepared by dissolving Ni-63 metal particles in HCl. The prototype for electroplating radioactive Ni-63 has been established. The electroplating was carried out by two-step processes such as preparation of ionic solution including Ni-63, and coating processes on the substrate.

  10. Electroplating Ni-63 metal ions in chloride bath on the Cu-plate

    International Nuclear Information System (INIS)

    Yoo, Kwon Mo; Uhm, Young Rang; Son, Kwang Jae; Park, Keun Yung

    2014-01-01

    Ni-63 plating is similar to other electroplating processes that employ soluble metal anodes. The nickel plating solution described by Watts in 1916 eventually replaced all other strategies in use up to that time. Charged Ni ions are formed by sulfate, sulfamate, chloride, and a Watts bath. However, charged Ni-63 ions are formed by dissolving metal Ni-63. Specifically, it requires the passage of direct current (DC) between two electrodes that are immersed in a conductive, aqueous solution of nickel salts. The flow of a DC causes one of the electrodes (the anode) to dissolve and the other electrode (the cathode) to become covered with nickel. The nickel in the solution is present in the form of divalent positively charged ions (Ni 2+ ). When the current flows, the positive ions react with two electrons (2e - ) and are converted into metallic nickel (Ni 0 ) at the cathode surface. In the present study, we optimize and established process for the electroplating Ni-63 on Cu-plate. Nanocrystalline nickel (Ni) coatings were synthesized by DC electro deposition at a current density of 15 mA/cm 2 . The bath was primarily composed of 0.2 M Ni ions, prepared by dissolving Ni-63 metal particles in HCl. The prototype for electroplating radioactive Ni-63 has been established. The electroplating was carried out by two-step processes such as preparation of ionic solution including Ni-63, and coating processes on the substrate

  11. Separation and radiometric determination of {sup 59}Ni, {sup 63}Ni, {sup 55}Fe, {sup 99}Tc and {sup 94}Nb in radioactive wastes of low and intermediate activities from PWR nuclear power plants; Separacao e determinacao radiometrica dos radionuclideos {sup 59}Ni, {sup 63}Ni, {sup 55}Fe, {sup 99}Tc e {sup 94}Nb em rejeitos radioativos de baixa e media atividades provenientes de centrais nucleares do tipo PWR

    Energy Technology Data Exchange (ETDEWEB)

    Temba, Eliane Silvia Codo

    2016-10-01

    The objective of this work was the development and establishment of a specific analytical protocol for the determination of the {sup 59}Ni, {sup 63}Ni, {sup 55}Fe, {sup 99}Tc and {sup 94}Nb radionuclides in low and intermediate radioactive waste samples of Almirante Alvaro Alberto Nuclear Power Plant, CNAAA, located in the city of Angra dos Reis, RJ. The separation and purification techniques used have taken into account the particularities of each radionuclide studied. Chemical separation methods were used, as well as carriers and radioisotope tracers, and ion-exchange and extraction chromatography involving specific resins. The main techniques used for the analysis and determination of the radionuclides were Liquid Scintillation Counting (LSC) and Gamma Spectrometry. Also used were Atomic Emission Spectroscopy with Inductively Coupled Plasma (ICP-AES) and Neutron Activation Analysis (NAA) for the chemical yield determination. Concerning to the {sup 59}Ni, {sup 63}Ni, {sup 55}Fe radionuclides, the methodology of sequential separation proved to be very appropriate for their separation and determination, as could be observed by the results obtained. Chemical yields in the range from 39 to 100%, and LSC counting efficiencies in the range of 37.8% for {sup 55}Fe, and 71.5% for {sup 63}Ni, are in accordance with the results found in the literature. The spectra of LSC showed that the methodology used to separation and purification of these radionuclides was very successful. The results for {sup 59}Ni have shown that the use of a {sup 55}Fe certified standard for calibration of the equipment was a viable alternative. In the case of the {sup 99}Tc radionuclide the use of rhenium as carrier and chemical yield monitor, resulted in high chemical yields. Use of Gamma Spectrometry analysis made it possible to check that the main interfering agents were actually removed with the combined use of anion exchange chromatography and TEVA resin. The chemical yield of {sup 94}Nb was

  12. Preparation of Ni-63 Source for the Fabrication of Betavoltaic Battery

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Joo; Uhm, Young Rang; Son, Kwang Jae; Hong, Jintae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    A beta radiation source, Ni-63, is prepared by electrical deposition of radioactive Ni-63 ions on a thin non-radioactive nickel foil. Ni-63 plating is similar to other electroplating processes that employ soluble metal anodes. Specifically, it requires the passage of direct current (DC) between two electrodes that are immersed in a conductive, aqueous solution of nickel salts. The flow of a DC causes one of the electrodes to dissolve and the other electrode to become covered with nickel. To establish the coating conditions for Ni-63, Niplating solution is prepared by dissolving metal particles, and the deposition conditions have been optimized by studying the influence of the current density. Also, Ni-63 is prepared by the electrophoretic deposition (EPD) is widely used for shaping, and coating for preparing uniform ceramic films with various thickness and assembling charged particles on electrodes with various morphologies. Since the discovery of repairing pit by using EPD method, well dispersed metal nanoparticles in suspension are applied to self-repairing pit on the metal surface. In order to deposit Ni nanoparticles, the EPD was executed by using two electrode cells in the suspension which was produced in organic solvents using HKD-2 as a dispersant. The coating of Ni particles on substrate of Ni plate was fabricated in suspension at 7 wt% HKD- 2 or more. It was found that the EPD process was important not only zeta potential of the suspension but also conductivity.

  13. Preparation of Ni-63 Source for the Fabrication of Betavoltaic Battery

    International Nuclear Information System (INIS)

    Kim, Jin Joo; Uhm, Young Rang; Son, Kwang Jae; Hong, Jintae

    2015-01-01

    A beta radiation source, Ni-63, is prepared by electrical deposition of radioactive Ni-63 ions on a thin non-radioactive nickel foil. Ni-63 plating is similar to other electroplating processes that employ soluble metal anodes. Specifically, it requires the passage of direct current (DC) between two electrodes that are immersed in a conductive, aqueous solution of nickel salts. The flow of a DC causes one of the electrodes to dissolve and the other electrode to become covered with nickel. To establish the coating conditions for Ni-63, Niplating solution is prepared by dissolving metal particles, and the deposition conditions have been optimized by studying the influence of the current density. Also, Ni-63 is prepared by the electrophoretic deposition (EPD) is widely used for shaping, and coating for preparing uniform ceramic films with various thickness and assembling charged particles on electrodes with various morphologies. Since the discovery of repairing pit by using EPD method, well dispersed metal nanoparticles in suspension are applied to self-repairing pit on the metal surface. In order to deposit Ni nanoparticles, the EPD was executed by using two electrode cells in the suspension which was produced in organic solvents using HKD-2 as a dispersant. The coating of Ni particles on substrate of Ni plate was fabricated in suspension at 7 wt% HKD- 2 or more. It was found that the EPD process was important not only zeta potential of the suspension but also conductivity

  14. Radiochemical procedure and quantitative determination of the activation product, 63Ni, in environmental soft water samples with high Ca and Mg phosphate concentration

    International Nuclear Information System (INIS)

    Jordan, N.; Michel, H.; Barci-Funel, G.; Barci, V.

    2008-01-01

    Nickel-63 is a low energy beta-emitter needing a radiochemical separation before β-counting. Several papers described the separation and the detection of 63 Ni in environmental samples. The method used in our work was first developed by SKWARZEC and HOLM. The main steps of this separation are the selective precipitation of nickel with dimethylglyoxime (DMG) and the use of the non-sorption of nickel on anion resin in hydrochloric acid solutions. In this paper, a new step is added to eliminate high quantities of calcium and magnesium phosphate disturbing the iron hydroxide precipitation step. The procedure has been applied to soft water samples: sediments, plants and fishes. The chemical yields are 60, 70 and 20%, respectively. The detection limit of 63 Ni by liquid scintillation spectrometer is 10 mBq. (author)

  15. Correlation factors for C-14, Cl-36, Ni-59, Ni-63, Mo-93, Tc-99, I-129 and Cs-135. In operational waste for SFR 1

    Energy Technology Data Exchange (ETDEWEB)

    Lindgren, Maria; Pettersson, Michael; Wiborgh, Marie (Kemakta AB, Stockholm (SE))

    2007-01-15

    The use of correlation factors is one possibility to estimate a reference radionuclide inventory for the purpose of safety assessment studies, when waste-type specific information is not at hand. The correlation factor approach requires that there is a correlation between the activity content of the difficult-to-measure nuclide and the key nuclide. A safety assessment of a future deep repository for low and intermediate level waste (SFL 3-5) was conducted during the second half of the 1990's. Within that project, correlation factors for estimating the inventory of radionuclides which are difficult to measure experimentally were developed. These factors have also partly been used to estimate a reference inventory for SFR 1. Based on a literature survey and recent reports published by SKB, it is concluded that new information is available making an update of some correlation factors relevant. For these radionuclides, reported data from estimations and measurements of radionuclide content and correlation factors in different types of radioactive wastes are summarised. The data is evaluated and updated correlation factors representative for fresh waste for eight radionuclides (C-14, Cl-36, Ni-59, Ni-63, Mo-93, Tc-99, I-129 and Cs-135) are suggested. New information from measurements in Swedish NPP has made it possible to define factors that are BWR and PWR specific for C-14, Ni-59 and Ni-63. The uncertainties in suggested data and the applicability of the correlation factors for estimates of the radionuclide content in operational waste are commented upon

  16. Single-particle and collective excitations in Ni-63

    OpenAIRE

    Albers, M.; Zhu, S.; Janssens, R. V. F.; Gellanki, Jnaneswari; Ragnarsson, Ingemar; Alcorta, M.; Baugher, T.; Bertone, P. F.; Carpenter, M. P.; Chiara, C. J.; Chowdhury, P.; Deacon, A. N.; Gade, A.; DiGiovine, B.; Hoffman, C. R.

    2013-01-01

    A study of excited states in Ni-63 up to an excitation energy of 28 MeV and a probable spin of 57/2 was carried out with the Mg-26(Ca-48,2 alpha 3n gamma)Ni-63 reaction at beam energies between 275 and 320 MeV. Three collective bands, built upon states of single-particle character, were identified. For two of the three bands, the transition quadrupole moments were extracted, herewith quantifying the deformation at high spin. The results have been compared with shell-model and cranked Nilsson-...

  17. Hyperfine structure of electronic levels and the first measurement of the nuclear magnetic moment of {sup 63}Ni

    Energy Technology Data Exchange (ETDEWEB)

    D' yachkov, A.B.; Firsov, V.A.; Gorkunov, A.A.; Labozin, A.V.; Mironov, S.M.; Saperstein, E.E.; Tolokonnikov, S.V.; Tsvetkov, G.O.; Panchenko, V.Y. [National Research Center ' ' Kurchatov Institute' ' , Moscow (Russian Federation)

    2017-01-15

    Laser resonant photoionization spectroscopy was used to study the hyperfine structure of the optical 3d{sup 8}4s{sup 2} {sup 3}F{sub 4} → 3d{sup 8}4s4p {sup 3}G{sup o}{sub 3} and 3d{sup 9}4s {sup 3}D{sub 3} → 3d{sup 8}4s4p {sup 3}G{sup o}{sub 3} transitions of {sup 63}Ni and {sup 61}Ni isotopes. Experimental spectra allowed us to derive hyperfine interaction constants and determine the magnetic dipole moment of the nuclear ground state of {sup 63}Ni for the first time: μ = +0.496(5)μ{sub N}. The value obtained agrees well with the prediction of the self-consistent theory of finite Fermi systems. (orig.)

  18. Studies on {sup 63}Ni based check-light sources for TL readers

    Energy Technology Data Exchange (ETDEWEB)

    Nagpal, J.S.; Venkataraman, G. [Bhabha Atomic Research Centre, Bombay (India). Radiation Protection Services Div.; Udhayakyumar, J. [Bhabha Atomic Research Centre, Bombay (India). Board of Radiation and Isotope Technology; Page, A.G. [Bhabha Atomic Research Centre, Bombay (India). Radiochemistry Div.

    1995-12-31

    The performance of indigenously produced, electrodeposited {sup 63}Ni sources having 10 mm x 10 mm active area and individually coupled to a plastic scintillator has been studied. TL phosphors such as CaF{sub 2}, CaF{sub 2}:Dy, CaF{sub 2}:Tm, CaF{sub 2}:Eu, TLD-100 and CaSO{sub 4}:Dy with {sup 63}Ni have been studied for their possible use as check-light sources for testing TL readers. Stability at ambient temperatures (298-323 K), build-up and decrease of light output with time have been examined. A preliminary study of the fluorescent species in the gamma irradiated plastic scintillator has been made. (author).

  19. Sorption properties of new composite materials suitable for radioanalytical determination of 59-Ni and 63-Ni

    International Nuclear Information System (INIS)

    Fisera, O.; Sebesta, F.

    2006-01-01

    New composite materials for separation and radioanalytical determination of radionickel ( 59, 63 Ni) were prepared and their sorption properties were examined. Chelating agents dimethylglyoxime (DMG) and diphenylglyoxime (DFG) as active components were immobilized in porous matrix of binding polymer polyacrylonitrile (PAN). Sorption properties of these materials were compared with commercial Ni Resin (Eichrom Technologies, USA). Weight distribution ratios, sorption kinetics and operating capacities were investigated during experiments performed. The highest weight distribution ratios were found for the material DFG-PAN. The sorbent DMG-PAN has the highest operating capacity. The fastest kinetics of nickel sorption was determined for the commercial Ni Resin. Elution of nickel with nitric acid solution allows subsequent and direct determination of radionickel by liquid scintillation counting. (author)

  20. Estimation of Ni63, Pu241, Pu242 and Am243 from Co60, Pu239, and Cm244 activities in groundwater samples

    International Nuclear Information System (INIS)

    Holcomb, H.P.

    1993-01-01

    The Part B Permit for F ampersand H Seepage Basins calls for analysis of several constituents of concern in groundwater monitoring wells. Four of these analytes are the radionuclides Ni 63 , Pu 241 , Pu 242 , and Am 243 . These are currently not being analyzed due to their very difficult, tedious analytical schemes coupled with their relatively low activity values. This report demonstrates how the activity value for Ni 63 , a week beta emitter, can be estimated from that of Co 60 , an easily detectable, high-energy gamma emitter. Similarly, estimates of Pu 241 , a beta emitter, and the alpha-emitting Pu 242 can be made from the activity value of the more easily detected Pu 239 . Am 243 can be estimated from the activity of Cm 244 , which is easier to detect because of a shorter half-life (higher specific activity) and the emission of higher energy alpha particles. These correlations are made under very specific parameters in order to ensure the validity of this approach. Therefore, assumptions must be established setting ground rules for establishing these activity relationships. Bases for these assumptions are explained and/or referenced. Their degree of uncertainty limits the accuracy of the data so that the term ''estimate'' is used. Such soundly-based, conservative estimates for these four rads can provide a tool for evaluating any hazards from their presence over the next several years. Hopefully, during this time, sufficient advances will be made in their radiochemical analyses and in counting techniques so that in the future, their activities may be quantitatively determined more easily and also more cost effectively

  1. Test Method for High β Particle Emission Rate of 63Ni Source Plate

    OpenAIRE

    ZHANG Li-feng

    2015-01-01

    For the problem of measurement difficulties of β particle emission rate of Ni-63 source plate used for Ni-63 betavoltaic battery, a relative test method of scintillation current method was erected according to the measurement principle of scintillation detector.β particle emission rate of homemade Ni-63 source plate was tested by the method, and the test results were analysed and evaluated, it was initially thought that scintillation current method was a feasible way of testing β particle emi...

  2. Distribution of /sup 63/Ni in mice by means of whole body autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Saito, T [Nihon Univ., Tokyo. School of Dentistry

    1974-11-01

    The uptake of Ni which was known to be contained in the dental alloy to the mammalian tissue was studied. /sup 63/Ni was injected intravenously to mice, and its distribution in their body was observed by counting radioactivity using whole body autoradiography and liquid scintillation counter from 30 minutes after the injection to 3 weeks later. Whole body autography revealed high uptake in the kidney, lung, incisor, intervertebral disc, epidermis cuticle, hair follicle, and liver during 30 minutes later to 8 hours period, and in the lung, renal cortex, central nerve, epidermis cuticle, and hair follicle during 2 days to 3 weeks period. /sup 63/Ni taken up in the tissue or organs rapidly disappeared by 8 hours period, and the rank of high uptake tissues slightly changed during 30 minutes later to 8 hours period. /sup 63/Ni administered in the body was considered to be excreted through the kidney, however, /sup 63/Ni taken up in the central nerve showed remarkably delayed excretion.

  3. Tracer diffusion of 60Co and 63Ni in amorphous NiZr alloy

    International Nuclear Information System (INIS)

    Hoshino, K.; Averback, R.S.; Hahn, H.; Rothman, S.J.

    1987-01-01

    Tracer diffusion of 60 Co and 63 Ni in equiatomic amorphous NiZr alloy in the temperature range between 486 and 641 0 K can be described by: D/sub Co/sup */ = 3.7 x 10 -7 exp[-(135 +- 14) kJ mole -1 /RT] m 2 /sec and D/sub Ni//sup */ = 1.7 x 10 -7 exp[-(140 +- 9) kJ mole -1 /RT] m 2 /sec. The values of D/sub Ni//sup */ are in reasonable agreement with those measured by the Rutherford backscattering technique. The measured diffusivities were independent of time, indicating that no relaxation took place during diffusion. 27 refs., 2 tabs

  4. 60Co, 63Ni and 94Nb soil-to-plant transfer in pot experiments

    International Nuclear Information System (INIS)

    Gerzabek, M.H.; Mohamad, S.A.; Mueck, K.; Horak, O.

    1995-01-01

    Soil-to-plant transfer factors for 60 Co, 63 Ni and 94 Nb were obtained via pot experiments with a Dystric Cambisol and a Calcic Chernozem, both from Lower Austria. Investigated plants were greenrape (Brassica napus oleifera L.), bean (Phaseolus vulgaris L.) and winter wheat (Triticum aestivum L.). The soil-to-plant transfer factors decreased from 63 Ni to 60 Co and 94 Nb. Mean values from all experiments ranged from 1.12 ( 63 Ni) to 0.0045 ( 94 Nb). The transfer values obtained for 60 Co and 63 Ni are comparable to literature values, but 94 Nb-transfer seems to be lower than previous estimates. All radionuclides showed differences between plant species and plant organs. Transfer values were also dependent on the soil type. (author)

  5. 63Ni schottky barrier nuclear battery of 4H-SiC

    International Nuclear Information System (INIS)

    Xiao-Ying Li; Yong Ren; Xue-Jiao Chen; Da-Yong Qiao; Wei-Zheng Yuan

    2011-01-01

    The design, fabrication, and testing of a 4H-SiC Schottky betavoltaic nuclear battery based on MEMS fabrication technology are presented in this paper. It uses a Schottky diode with an active area of 3.14 mm 2 to collect the charge from a 4 mCi/cm 2 63 Ni source. Some of the critical steps in process integration for fabricating silicon carbide-based Schottky diode were addressed. A prototype of this battery was fabricated and tested under the illumination of the 63 Ni source with an activity of 0.12 mCi. An open circuit voltage (V OC ) of 0.27 V and a short circuit current density (J SC ) of 25.57 nA/cm 2 are measured. The maximum output power density (P max ) of 4.08 nW/cm 2 and power conversion efficiency (η) of 1.01% is obtained. The performance of this battery is expected to be significantly improved by using larger activity and optimizing the design and processing technology of the battery. By achieving comparable performance with previously constructed p-n or p-i-n junction energy conversion structures, the Schottky barrier diode proves to be a feasible approach to achieve practical betavoltaics. (author)

  6. Performance of Spent Mushroom Farming Waste (SMFW) Activated Carbon for Ni (II) Removal

    Science.gov (United States)

    Desa, N. S. Md; Ghani, Z. Ab; Talib, S. Abdul; Tay, C. C.

    2016-07-01

    The feasibility of a low cost agricultural waste of spent mushroom farming waste (SMFW) activated carbon for Ni(II) removal was investigated. The batch adsorption experiments of adsorbent dosage, pH, contact time, metal concentration, and temperature were determined. The samples were shaken at 125 rpm, filtered and analyzed using ICP-OES. The fifty percent of Ni(II) removal was obtained at 0.63 g of adsorbent dosage, pH 5-6 (unadjusted), 60 min contact time, 50 mg/L Ni(II) concentration and 25 °C temperature. The evaluated SMFW activated carbon showed the highest performance on Ni(II) removal compared to commercial Amberlite IRC86 resin and zeolite NK3. The result indicated that SMFW activated carbon is a high potential cation exchange adsorbent and suitable for adsorption process for metal removal. The obtained results contribute toward application of developed SMFW activated carbon in industrial pilot study.

  7. Bioaccumulation, distribution and retention of 63Ni2+ in the brown trout (Salmo trutta)

    International Nuclear Information System (INIS)

    Tjaelve, Hans; Gottofrey, James; Borg, Kathleen

    1988-01-01

    Brown trout, Salmo trutta, were exposed to water containing 0.1 or 10 μgl -1 of 63 Ni 2+ for 1 or 3 weeks. Additional trout were exposed to 0.1 or 10 μgl -1 of 63 Ni 2+ during 3 weeks followed by a 1- or 3-week period without exposure to the metal. At termination of the experimental periods the uptake and distribution of the 63 Ni 2+ in the fishes were determined by whole-body autoradiography and liquid scintillation spectrometry. The average whole-fish concentration of 63 Ni 2+ in the fishes was about 3 times higher than the concentration of 6 Ni 2+ in the water after 1 week's exposure and about 7-8 times higher than in the water after three weeks' exposure. Our results show that there is a moderate bioaccumulation of nickel by fishes from the water. (author)

  8. Development of diode junction nuclear battery using 63Ni

    International Nuclear Information System (INIS)

    Ulmen, B.; Miley, G.H.; Desai, P.D.; Moghaddam, S.; Masel, R.I.

    2009-01-01

    The diode junction nuclear battery is a long-lived, high-energy-density, but low electrical current power source with many specialized applications. In this type of battery, nuclear radiation is directly converted to electric power. A model is described and used to design the device configuration. Details of fabrication and testing of a planar geometry battery with 63 Ni radiation source are described. The electron beam induced current (EBIC) measurement technique and CASINO Monte Carlo simulation code were employed to analyze the device performance. Finally, an improved design with 3-dimensional surface microstructures that will provide improved performance is presented. (author)

  9. Separation for the determination of 59/63Ni in radioactive wastes

    International Nuclear Information System (INIS)

    Lee, Chang Heon; Choi, Kwang Soon; Jee, Kwang Young; Kim, Won Ho; Jung, Kie Chul

    2005-01-01

    A study on the separation of 99 Tc, 94 Nb, 55 Fe, 90 Sr and 59/63 Ni in various radioactive wastes discharged from nuclear power plants has been performed for a use in their quantification which is indispensable for the evaluation of the radionuclide inventory. Ni was recovered along with Ca, Mg, Al, Cr, Ti, Mn, Ce, Na, K. and Cu through the sequential separation procedure of Re (as a surrogate of 99 Tc), Nb, Fe and Sr by anion exchange and Sr-SPec extraction chromatography. In this research, chemical separation of Ni from the co-existing elements was investigated by cation exchange and Ni-Spec extraction chromatography. Precipitation behaviour of Ni and the co-existing elements with dimethylglyoxime(DMG) was investigated in ammonium citrate/ethanol-H 2 O and tartaric acid/acetone-H 2 O in order to purify separated Ni fractions and to prepare 59/63 Ni source for the radioactivity measurement using a gas proportional counter. Recovery of Ni separated through ion exchange chromatographic separation procedure was 93.1% with relative standard deviation of 0.9%. In addition, recovery of Ni with DMG in the tartaric acid/acetone-H 2 O was 85.6% with relative standard deviation of 1.9%

  10. Crystallization behavior and the thermal properties of Zr63Al7.5Cu17.5Ni10B2 bulk amorphous alloy

    International Nuclear Information System (INIS)

    Jang, J.S.C.; Chang, L.J.; Jiang, Y.T.; Wong, P.W.

    2003-01-01

    The ribbons of amorphous Zr 63 Al 7.5 Cu 17.5 Ni 10 B 2 alloys with 0.1 mm thickness were prepared by melt spinning method. The thermal properties and micro structural development during the annealing of amorphous alloy have been investigated by a combination of differential thermal analysis, differential scanning calorimetry, high-temperature optical microscope, X-ray diffractometry and TEM. The glass transition temperature for the Zr 63 Al 7.5 Cu 17.5 Ni 10 B 2 alloys are measured about 645 K (372 C). This alloy also obtains a large temperature interval ΔT x about 63 K. Meanwhile, the calculated T rg for Zr 63 Al 7.5 Cu 17.5 Ni 10 B 2 alloy presents the value of 0.57. The activation energy of crystallization for the alloy Zr 63 Al 7.5 Cu 17.5 Ni 10 B 2 was about 370± 10 kJ/mole as determined by the Kissinger and Avrami plot, respectively. These values are about 20% higher than the activation energy of crystallization for the Zr 65 Al 7.5 Cu 17.5 Ni 10 alloy (314 kJ/mol.). This implies that the boron additions exhibit the effect of improving the thermal stability for the Zr-based alloy. The average value of the Avrami exponent n were calculated to be 1.75±0.15 for Zr 63 Al 7.5 Cu 17.5 Ni 10 B 2 alloy. This indicates that this alloy presents a crystallization process with decreasing nucleation rate. (orig.)

  11. Prediction of the phyto-availability of two radionuclides (63Ni and 99Tc) in soils

    International Nuclear Information System (INIS)

    Denys, S.

    2001-10-01

    A thorough knowledge of the behavior of long-lived radionuclides in the biosphere is needed for the safety assessment of deep underground nuclear waste repositories. Soils support terrestrial food chains and are thus a key compartment in the determination of transfers of radionuclides to Man. Tyre prediction of soil-to-plant transfers is based on the characterization of the phyto-availability of radionuclides in soils by taking into account all the transfer processes inside the soil profile. The aim of this study was to predict phyto-availability of radionuclides in cultivated soils. The phyto-availability of two radionuclides varying in their mobility, 63 Ni and 99 Tc, was studied a the level of the sieved soil sample and of the cultivated soil profile. Three soils showing contrasted hydraulic and physico-chemical properties were sampled in order to isolate undisturbed soil cores (50 cm x 50 cm): a rendzina, a clayey colluvial soil and a sandy-loam acidic soil. The cores were placed in a greenhouse and equipped with porous cups and leachate collectors in order to sample soil solution and drainage water. The first year, maize (Zea mays L.) was grown and irrigated. Soils were contaminated once on the surface by irrigation at the beginning of the summer season. After harvest, in early October, winter wheat (Triticum aestivum L.) was sawn. The cores were again contaminated in March: once in the case of 63 Ni and three tinges for 99 Tc. Transfers of radionuclides to water and aerial parts of crops were monitored throughout the two-year experiment. Results showed that the phyto-availability of radionuclides can be estimated from that of chemical or isotopic analogues ire the case of simple or multiple contamination. 63 Ni is diluted in the pool of isotopically exchangeable Ni 2+ ions in the soils. 99 TcO 4 - is diluted in the pool of available NO 3 - ions. Radionuclides stayed in the upper layer of the soils until harvest due to the high evapotranspiration rate of maize

  12. Prediction of the phyto-availability of two radionuclides ({sup 63}Ni and {sup 99}Tc) in soils; Prediction de la phytodisponibilite de deux radionucleides ({sup 63}Ni et {sup 99}Tc) dans les sols

    Energy Technology Data Exchange (ETDEWEB)

    Denys, S

    2001-10-01

    A thorough knowledge of the behavior of long-lived radionuclides in the biosphere is needed for the safety assessment of deep underground nuclear waste repositories. Soils support terrestrial food chains and are thus a key compartment in the determination of transfers of radionuclides to Man. Tyre prediction of soil-to-plant transfers is based on the characterization of the phyto-availability of radionuclides in soils by taking into account all the transfer processes inside the soil profile. The aim of this study was to predict phyto-availability of radionuclides in cultivated soils. The phyto-availability of two radionuclides varying in their mobility, {sup 63}Ni and {sup 99}Tc, was studied a the level of the sieved soil sample and of the cultivated soil profile. Three soils showing contrasted hydraulic and physico-chemical properties were sampled in order to isolate undisturbed soil cores (50 cm x 50 cm): a rendzina, a clayey colluvial soil and a sandy-loam acidic soil. The cores were placed in a greenhouse and equipped with porous cups and leachate collectors in order to sample soil solution and drainage water. The first year, maize (Zea mays L.) was grown and irrigated. Soils were contaminated once on the surface by irrigation at the beginning of the summer season. After harvest, in early October, winter wheat (Triticum aestivum L.) was sawn. The cores were again contaminated in March: once in the case of {sup 63}Ni and three tinges for {sup 99}Tc. Transfers of radionuclides to water and aerial parts of crops were monitored throughout the two-year experiment. Results showed that the phyto-availability of radionuclides can be estimated from that of chemical or isotopic analogues ire the case of simple or multiple contamination. {sup 63}Ni is diluted in the pool of isotopically exchangeable Ni{sup 2+} ions in the soils. {sup 99}TcO{sub 4}- is diluted in the pool of available NO{sub 3}- ions. Radionuclides stayed in the upper layer of the soils until harvest due

  13. Prediction of 4H–SiC betavoltaic microbattery characteristics based on practical Ni-63 sources

    International Nuclear Information System (INIS)

    Gui, Gui; Zhang, Kan; Blanchard, James P.; Ma, Zhenqiang

    2016-01-01

    We have investigated the performance of 4H–SiC betavoltaic microbatteries under exposure to the practical Ni-63 sources using the Monte Carlo method and Synopsys® Medici device simulator. A typical planar p–n junction betavoltaic device with the Ni-63 source of 20% purity on top is modeled in the simulation. The p–n junction structure includes a p+ layer, a p− layer, an n+ layer, and an n− layer. In order to obtain an accurate and valid predication, our simulations consider several practical factors, including isotope impurities, self-absorption, and full beta energy spectra. By simulating the effects of both the p–n junction configuration and the isotope source thickness on the battery output performance, we have achieved the optimal design of the device and maximum energy conversion efficiency. Our simulation results show that the energy conversion efficiency increases as the doping concentration and thickness of the p− layer increase, whereas it is independent of the total depth of the p–n junction. Furthermore, the energy conversion efficiency decreases as the thickness of the practical Ni-63 source increases, because of self-absorption in the isotope source. Therefore, we propose that a p–n junction betavoltaic cell with a thicker and heavily doped p− layer under exposure to a practical Ni-63 source with an appreciable thickness could produce the optimal energy conversion efficiency. - Highlights: • Different thicknesses of Ni-63 isotope sources with 20% purity were employed. • A self-absorption model was constructed for the beta energy spectra of Ni-63 sources. • The optimization strategies for betavoltaic microbatteries were outlined.

  14. Long-lived radionuclides in low-level waste

    International Nuclear Information System (INIS)

    Cline, J.E.; Coe, L.J.

    1983-01-01

    In July 1982, the Low-Level Waste Licensing Branch of the NRC, anticipating the impact of the proposed Part 61 to 10 CFR, funded a two-year project by SAI to study the radionuclide contents of LWR generated in low-level waste. The objectives of the study are: (1) to analyze, using verified techniques, 150 archived samples for specified beta- and x-ray-emitting nuclides that had not previously been analyzed; (2) to analyze twenty new samples obtained from operating plants for all relevant nuclides and compare them to previous data to ascertain trends; (3) to develop empirical scaling factors through the use of which concentrations of hard-to-analyze nuclides can be estimated from analyses of the gamma-ray emitting nuclides. The new samples are analyzed and the results are summarized and interpreted. Over fifty archived samples have also been analyzed. We discuss scaling factor development. Factors are presented that relate 63 Ni and 59 Ni to 60 Co for PWRs and to 58 Co for BWRs, 90 Sr to 137 Cs for BWRs and 241 Pu, 239 Pu, 241 Am, and 244 Cm to 144 Ce for all LWRs. 8 figures, 3 tables

  15. [sup 60]Co, [sup 63]Ni and [sup 94]Nb soil-to-plant transfer in pot experiments

    Energy Technology Data Exchange (ETDEWEB)

    Gerzabek, M.H.; Mohamad, S.A.; Mueck, K.; Horak, O. (Austrian Research Centre Seibersdorf (Austria). Div. of Life Sciences)

    1994-01-01

    Soil-to-plant transfer factors for [sup 60]Co, [sup 63]Ni and [sup 94]Nb were obtained via pot experiments with a Dystric Cambisol and a Calcic Chernozem, both from Lower Austria. Investigated plants were greenrape (Brassica napus oleifera L.), bean (Phaseolus vulgaris L.) and winter wheat (Triticum aestivum L.). The soil-to-plant transfer factors decreased from [sup 63]Ni to [sup 60]Co and [sup 94]Nb. Mean values from all experiments ranged from 1.12 ([sup 63]Ni) to 0.0045 ([sup 94]Nb). The transfer values obtained for [sup 60]Co and [sup 63]Ni are comparable to literature values, but [sup 94]Nb-transfer seems to be lower than previous estimates. All radionuclides showed differences between plant species and plant organs. Transfer values were also dependent on the soil type. (author).

  16. Natural Ni speciation in the Callovo-Oxfordian clay rocks: implications for potential 63Ni isotopic exchange and retention mechanisms

    International Nuclear Information System (INIS)

    Grangeon, S.; Tournassat, C.; Schaefer, T.; Lerouge, C.; Wille, G.; Giffaut, E.

    2010-01-01

    Document available in extended abstract form only. In the perspective of deep underground long-term nuclear waste storage, 63 Ni is considered as a priority radio-element to be studied. 63 Ni behaviour prediction is made difficult mainly because its geochemical behaviour is still subject to debate. For instance, the solubility of Ni simple compounds at high pH is ill-defined, and the knowledge on solubility control phases is still pending. Clay rocks such as Callovo-Oxfordian (COx) contain non negligible amounts of natural and stable isotopes of Ni. As a consequence, a good understanding of the natural speciation of Ni in the formation could help to understand 63 Ni controls in this environment, including long term isotopic exchange with naturally present Ni. We focused our study on the COx formation, where the Bure (France) ANDRA underground research laboratory is located. Speciation of naturally occurring Ni was studied by combining chemical, microscopic and spectrometric methods. Chemical methods consisted of total rock analyses and sequential extractions on various COx samples representative of the variability of the formation (from carbonate rich samples to clay rich samples). This method enabled quantifying the main Ni reservoirs. Physical methods were used to get a closer look at the Ni-bearing phases. Optical and scanning electron microscopy techniques were used to identify and isolate minerals from thin rock sections, originating from different geological horizons. Chemical results indicate that the mean Ni concentration in the Callovo-Oxfordian clay rock is of ∼30 ppm (10 -6 g/g). Identified Ni-bearing minerals were mainly primary minerals (biotite, chlorite, muscovite), calcite and pyrite; organic matter being also observed. Electron microprobe and X-ray fluorescence analyses were performed in order to quantify the amounts and variability of Ni contents in these different Callovo-Oxfordian components. Ni is occasionally present in primary minerals with

  17. Neutron Capture Cross Section of Unstable Ni63: Implications for Stellar Nucleosynthesis

    Science.gov (United States)

    Lederer, C.; Massimi, C.; Altstadt, S.; Andrzejewski, J.; Audouin, L.; Barbagallo, M.; Bécares, V.; Bečvář, F.; Belloni, F.; Berthoumieux, E.; Billowes, J.; Boccone, V.; Bosnar, D.; Brugger, M.; Calviani, M.; Calviño, F.; Cano-Ott, D.; Carrapiço, C.; Cerutti, F.; Chiaveri, E.; Chin, M.; Colonna, N.; Cortés, G.; Cortés-Giraldo, M. A.; Diakaki, M.; Domingo-Pardo, C.; Duran, I.; Dressler, R.; Dzysiuk, N.; Eleftheriadis, C.; Ferrari, A.; Fraval, K.; Ganesan, S.; García, A. R.; Giubrone, G.; Gómez-Hornillos, M. B.; Gonçalves, I. F.; González-Romero, E.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Gurusamy, P.; Jenkins, D. G.; Jericha, E.; Kadi, Y.; Käppeler, F.; Karadimos, D.; Kivel, N.; Koehler, P.; Kokkoris, M.; Korschinek, G.; Krtička, M.; Kroll, J.; Langer, C.; Leeb, H.; Leong, L. S.; Losito, R.; Manousos, A.; Marganiec, J.; Martínez, T.; Mastinu, P. F.; Mastromarco, M.; Meaze, M.; Mendoza, E.; Mengoni, A.; Milazzo, P. M.; Mingrone, F.; Mirea, M.; Mondelaers, W.; Paradela, C.; Pavlik, A.; Perkowski, J.; Pignatari, M.; Plompen, A.; Praena, J.; Quesada, J. M.; Rauscher, T.; Reifarth, R.; Riego, A.; Roman, F.; Rubbia, C.; Sarmento, R.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Tagliente, G.; Tain, J. L.; Tarrío, D.; Tassan-Got, L.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Versaci, R.; Vermeulen, M. J.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Ware, T.; Weigand, M.; Weiß, C.; Wright, T. J.; Žugec, P.

    2013-01-01

    The Ni63(n,γ) cross section has been measured for the first time at the neutron time-of-flight facility n_TOF at CERN from thermal neutron energies up to 200 keV. In total, capture kernels of 12 (new) resonances were determined. Maxwellian averaged cross sections were calculated for thermal energies from kT=5-100keV with uncertainties around 20%. Stellar model calculations for a 25M⊙ star show that the new data have a significant effect on the s-process production of Cu63, Ni64, and Zn64 in massive stars, allowing stronger constraints on the Cu yields from explosive nucleosynthesis in the subsequent supernova.

  18. Standardization of 3H, 14C and 63Ni radiation sources by calorimetric method

    International Nuclear Information System (INIS)

    Khol'nova, E.A.; Kul'kova, L.P.

    1979-01-01

    The calorimetric method of determination of activity of radionuclides 3 H, 14 C and 63 Ni with low mean energies of β-particles has, as compare to other methods which had been used for determination of activity of these nuclides, a number of advantages, because a nuclide to be measured can be introduced into the calorimeter in any physical and chemical state. It is not necessary to distroy integrity ane leek-proofness of a source wnich can be of arbitrary type. There is no correction for absorption and self-absorption of β-particles and measuring instruments are relatively simple. As a limitation of this method is it's low sensitivity which can be owercomed by means of application of modern high sensitivity calorimeters. Such calorimeters have been developed in the Mendeleev All-Union research Institute. The calorimetric installation consists of 3 independent β-calorimeters of differential-double type, working in the regime of heat equilibrium and beeng intended for different by sise and shape sources. Then, there are thermostatting device of special desighn and electric measuring device. Number of thermocouples in each calorimeter is from 75 to 120 and sensitivity of calorimeters is from 2.45x10 -7 to 4.5x10 -7 Bt/mm depending on the type of calorimeter. Calorimeters are intended for measuring activities from 10 9 to 10 12 Bk. Error of measurement of activities equals 0.8-1.5% (with confidence level of 0.99%). The main portion of error consists of error in the medium energy β-spectra. The calorimeter error itself is much more lower. Soueces, which have been measured in the calorimeter than can be used for preparation of solutions and sources of lower activity [ru

  19. Determination of 63Ni and 55Fe in nuclear waste samples using radiochemical separation and liquid scintillation counting

    DEFF Research Database (Denmark)

    Hou, Xiaolin; Frøsig Østergaard, L.; Nielsen, S.P.

    2005-01-01

    An analytical method for the determination of Ni-63 and Fe-55 in nuclear waste samples such as graphite, heavy concrete, aluminium and lead was developed. Different decomposition methods (i.e. ashing, acid digestion and alkali fusion) were investigated for the decomposition of the samples...... by extraction chromatography. The purified Ni-63 and Fe-55 was then measured by liquid scintillation counting. The chemical yields of the separation procedures for Fe-55 and Ni-63 are above 90% and the decontamination factors for all interfering radionuclides are more than 10(5). The detection limits...

  20. Simulation on the optimum thickness of Ni-63 for nuclear battery development

    International Nuclear Information System (INIS)

    Kang, S. K.; Kang, Y. R.; Lim, H. J.; Rhee, D. J.; Jeong, D. H.; Son, K. J.; Choi, B. G.

    2013-01-01

    A nuclear battery is an electrical device to obtain the electrical power using radiations from a radioisotope. The beta-ray emitting radioisotopes such as H-3, Ni-63, Pm-147, Tc-99 were used for producing the nuclear battery. Specifically, long half-life (>50 years) radioisotopes were preferred for developing a long-life battery. Recently, the nuclear battery is considered to be an alternate energy source. The efficiency of the output power of the nuclear battery can be improved by changing the fabrication process. Designing the shape of the radioisotope and the semiconductor structures, and determining the type of the elements in the battery in manufacturing process were required before the production of the nuclear battery. In this study, the flat Ni-63 sources with various thicknesses were simulated to maximize the efficiency of the transfer of the total energy of beta-rays into the electrical power. The minimum thicknesses of the silicon layer and the Ni-63 source in the nuclear battery for the optimized efficiency were determined to be 16 μm and 2.0 μm respectively. This simulation results would be applied to the development in the high efficiency nuclear battery. Further study to determine the geometry and the shape of the radioisotopes and the semiconductors for developing the more efficient nuclear battery would be desired

  1. Radiochemical methodologies applied to analytical characterization of low and intermediate level wastes from nuclear power plants

    International Nuclear Information System (INIS)

    Monteiro, Roberto Pellacani G.; Júnior, Aluísio Souza R.; Kastner, Geraldo F.; Temba, Eliane S.C.; Oliveira, Thiago C. de; Amaral, Ângela M.; Franco, Milton B.

    2017-01-01

    The aim of this work is to present radiochemical methodologies developed at CDTN/CNEN in order to answer a program for isotopic inventory of radioactive wastes from Brazilian Nuclear Power Plants. In this program some radionuclides, 3 H, 14 C, 55 Fe, 59 Ni, 63 Ni, 90 Sr, 93 Zr, 94 Nb, 99 Tc, 129 I, 235 U, 238 U, 238 Pu, 239 + 240 Pu, 241 Pu, 242 Pu, 241 Am, 242 Cm e 243 + 244 Cm, were determined in Low Level Wastes (LLW) and Intermediate Level Wastes (ILW) and a protocol of analytical methodologies based on radiochemical separation steps and spectrometric and nuclear techniques was established. (author)

  2. Low content of Pt supported on Ni-MoC{sub x}/carbon black as a highly durable and active electrocatalyst for methanol oxidation, oxygen reduction and hydrogen evolution reactions in acidic condition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yan; Zang, Jianbing; Jia, Shaopei; Tian, Pengfei; Han, Chan; Wang, Yanhui, E-mail: diamond_wangyanhui@163.com

    2017-08-01

    Highlights: • Ni-MoC{sub x}/C catalyst support was synthesized by a two-step method. • 10Pt/Ni-MoC{sub x}/C was an active and durable low Pt catalyst for MOR, ORR and HER. • The high stability of 10Pt/Ni-MoC{sub x}/C was ascribed to the anchoring effect of MoC{sub x}. • High activity of 10Pt/Ni-MoC{sub x}/C was due to a synergistic of Pt, Ni, MoO{sub x} and MoC{sub x}. - Abstract: Nickel and molybdenum carbide modified carbon black (Ni-MoC{sub x}/C) was synthesized by a two-step microwave-assisted deposition/carbonthermal reduction method and characterized by X-ray diffraction, transmission electron microscopy, energy dispersive spectroscopy and X-ray photoelectron spectroscopy. The as-prepared Ni-MoC{sub x}/C supported Pt (10 wt%) electrocatalyst (10Pt/Ni-MoC{sub x}/C) was synthesized through a microwave-assisted reduction method and 10Pt/Ni-MoC{sub x}/C exhibited high electrocatalytic activity for methanol oxidation, oxygen reduction and hydrogen evolution reactions. Results showed that 10Pt/Ni-MoC{sub x}/C electrocatalyst had better electrocatalytic activity and stability performance than 20 wt% Pt/C (20Pt/C) electrocatalyst. Among them, the electrochemical surface area of 10Pt/Ni-MoC{sub x}/C reached 68.4 m{sup 2} g{sup −1}, which was higher than that of 20Pt/C (63.2 m{sup 2} g{sup −1}). The enhanced stability and activity of 10Pt/Ni-MoC{sub x}/C electrocatalyst were attributed to: (1) an anchoring effect of Ni and MoC{sub x} formed during carbonthermal reduction process; (2) a synergistic effect among Pt, Ni, MoO{sub x} and MoC{sub x}. These findings indicated that 10Pt/Ni-MoC{sub x}/C was a promising electrocatalyst for direct methanol fuel cells.

  3. Automated rapid method for the determination of Ni-63 and Fe-55 in environmental samples from dismantling of nuclear facilities; Automatisiertes Schnellverfahren zur Bestimmung von Ni-63 und Fe-55 in Umweltproben aus dem Rueckbau

    Energy Technology Data Exchange (ETDEWEB)

    Coeguer, E.; Zoriy, M. [Forschungszentrum Juelich GmbH (Germany). Geschaeftsbereich Sicherheit und Strahlenschutz

    2016-07-01

    The shutdown and decommissioning of nuclear facilities is continuing in Germany. As a consequence, due to the resulting radioactive waste, it becomes more and more important to analyse the nuclides in the produced radioactive waste efficiently. Thereby a fast and reliable analysis procedure for the determination of Ni-63 and Fe-55 is needed. Therefor we developed recently a method for the determination of Ni-63 and Fe-55 in waste water based on extraction chromatography. The method was optimized in order to improve the sample preparation. The samples with usually relatively high matrix content were decomposed by wet chemical digestion. A unique feature of the current method is the use of an automated separating column module (TSM), developed in our laboratory, in order to selectively separate the radionuclides of interest. At last separated Ni-63 and Fe-55 are analyzed by means of Liquid Scintillation Counting (LSC). To validate the developed procedure synthetically prepared (doped) matrix-matched samples as well as certificated standards were analyzed. The obtained results were in a good agreement with the expected or certified values.

  4. Use of Ni63 Overvoltage Gap Switches in the Flight Termination Systems on Boosters Launched from U.S. Army Kwajalein Atoll (USAKA)

    Science.gov (United States)

    1990-05-01

    COMMAND AGENCY: United States Army Strategic Defense Command. ACTION: Use of Ni63 Overvoltage Gap Switches in the Flight Termination Systems on Boosters...SOURCE OF FUNDING NUMBERS PROGRAM PROJECT TASK WORK UNIT ELEMENT NO. NO. NO. ACCESSION NO. I TITLE (Include Security Claification) Use of Ni63 ...U) 1 PERSONAL AUTHOR(S) Ni63 Environmental Assessment Team, Mr. Randy Gallien (Chairman) 1𔄁. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT

  5. The neutron capture cross section of the ${s}$-process branch point isotope $^{63}$Ni

    CERN Multimedia

    Neutron capture nucleosynthesis in massive stars plays an important role in Galactic chemical evolution as well as for the analysis of abundance patterns in very old metal-poor halo stars. The so-called weak ${s}$-process component, which is responsible for most of the ${s}$ abundances between Fe and Sr, turned out to be very sensitive to the stellar neutron capture cross sections in this mass region and, in particular, of isotopes near the seed distribution around Fe. In this context, the unstable isotope $^{63}$Ni is of particular interest because it represents the first branching point in the reaction path of the ${s}$-process. We propose to measure this cross section at n_TOF from thermal energies up to 500 keV, covering the entire range of astrophysical interest. These data are needed to replace uncertain theoretical predicitons by first experimental information to understand the consequences of the $^{63}$Ni branching for the abundance pattern of the subsequent isotopes, especially for $^{63}$Cu and $^{...

  6. A very sensitive LSC procedure to determine Ni-63 in environmental samples, steel and concrete

    International Nuclear Information System (INIS)

    Scheuerer, C.; Schupfner, R.; Schuettelkopf, H.

    1995-01-01

    This procedure to determine Ni-63 contributes to a safe and economically reasonable decommissioning of nuclear power plants. Co-60, Fe-55 and Ni-63 are the most abundant long-lived radionuclides associated with contaminated piping, hardware and concrete for a period of several decades of years after shutdown. Samples are carefully ashed leached, or dissolved by suitable mixtures of acids. The analysis starts with the absorption Ni 2+ on the chelating resin CHELEX 100. The next purification steps include an anionic exchange column and a precipitation as Ni-dimethyl-glyoxime, which is extracted into chloroform. After reextraction with sulfuric acid the solution containing Ni 2+ is mixed with a scintillation cocktail and counted in an anticoincidence shielded LSC. The decontamination factors are determined for all important artificially and naturally occurring radionuclides ranging form above 10 4 to 10 9 . The chemical yield adopts a value of (95±5)%. Up to maximum sample amounts of 0.4 g steel, 5 g concrete and about 100 g of environmental samples the detection limits are about 5 mBq per sample or 12 mBq/g steel, 1 mBq/g concrete and 0.05 mBq/g environmental sample at a counting time of 1000 minutes. (author) 16 refs.; 2 figs.; 2 tabs

  7. Considerations on the activity concentration determination method for low-level waste packages and nuclide data comparison between different countries

    International Nuclear Information System (INIS)

    Kashiwagi, M.; Mueller, W.

    2000-01-01

    In low-level waste disposal, acceptable activity concentration limits are regulated for individual nuclides and groups of nuclides according to the conditions of each disposal site. Such regulated limits principally concern total alpha and beta /gamma activity as well as nuclides such as C-14, Ni-63, and Pu-238 which are long-lived and difficult to measure (hereinafter referred to as difficult-to-measure nuclides). Before waste packages are transported to the disposal site, the activities or activity concentrations of the regulated nuclides and groups of nuclides in the waste packages must be assessed and declared. A generally applicable theoretical method to determine these activities is lacking at present. Therefore, to meet this requirement, for NPP waste each country independently samples actual waste and carries out radiochemical analyses on these samples. The activity concentrations of difficult-to-measure nuclides are then determined by statistical correlation of the measured data between difficult-to-measure nuclides and Co-60 and Cs-137 which are measurable from outside the waste packages (hereinafter referred to as key nuclides). This method is called 'Scaling Factor Method'. It is widely adopted as a method for determining the activity concentrations of the limited nuclides in low-level waste packages from NPP, and it is also approved by responsible authorities in the respective country. In the past, each country independently determined scaling factors based on measurements on samples from the local NPPs. In the first part of this study, the possibility of an international scaling factor assessment using a database integrating data from different countries was studied by comparing radiochemical analysis data between Germany, Japan, and the United States. These countries have accumulated a large number of those nuclide data required to determine scaling factors. Statistical values such as correlation coefficients change with an accumulation of data. In

  8. Validation of a method for the determination of 14C and 63Ni in samples of concrete

    International Nuclear Information System (INIS)

    Rosskopfova, Olga; Galambos, Michal; Pupak, Matus

    2009-01-01

    For the determination of 14 C, the concrete sample was distilled in inert atmosphere and the released 14 CO 2 was trapped in a scintillation vial with Carbo-Sorb E. Permafluor E was added and the well mixed sample was kept in the dark for 24 h, after which the preparation was measured on a liquid scintillation spectrometer. For the determination of 63 Ni the sample was ignited at 550 deg C overnight and subjected to acid leaching. Nickel was then separated by a procedure which included separation from Fe by precipitation with NH 4 OH and precipitation of Ni with dimethylglyoxime and purification by extraction chromatography on Ni Resin; 63 Ni was determined by liquid scintillation spectrophotometry of the beta radiation. The participation in the interlaboratory comparison exercise gave evidence of the reliability and quality of the results achieved by the laboratory. (P.A.)

  9. Low content of Pt supported on Ni-MoCx/carbon black as a highly durable and active electrocatalyst for methanol oxidation, oxygen reduction and hydrogen evolution reactions in acidic condition

    Science.gov (United States)

    Zhang, Yan; Zang, Jianbing; Jia, Shaopei; Tian, Pengfei; Han, Chan; Wang, Yanhui

    2017-08-01

    Nickel and molybdenum carbide modified carbon black (Ni-MoCx/C) was synthesized by a two-step microwave-assisted deposition/carbonthermal reduction method and characterized by X-ray diffraction, transmission electron microscopy, energy dispersive spectroscopy and X-ray photoelectron spectroscopy. The as-prepared Ni-MoCx/C supported Pt (10 wt%) electrocatalyst (10Pt/Ni-MoCx/C) was synthesized through a microwave-assisted reduction method and 10Pt/Ni-MoCx/C exhibited high electrocatalytic activity for methanol oxidation, oxygen reduction and hydrogen evolution reactions. Results showed that 10Pt/Ni-MoCx/C electrocatalyst had better electrocatalytic activity and stability performance than 20 wt% Pt/C (20Pt/C) electrocatalyst. Among them, the electrochemical surface area of 10Pt/Ni-MoCx/C reached 68.4 m2 g-1, which was higher than that of 20Pt/C (63.2 m2 g-1). The enhanced stability and activity of 10Pt/Ni-MoCx/C electrocatalyst were attributed to: (1) an anchoring effect of Ni and MoCx formed during carbonthermal reduction process; (2) a synergistic effect among Pt, Ni, MoOx and MoCx. These findings indicated that 10Pt/Ni-MoCx/C was a promising electrocatalyst for direct methanol fuel cells.

  10. Radiochemical methodologies applied to analytical characterization of low and intermediate level wastes from nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Monteiro, Roberto Pellacani G.; Júnior, Aluísio Souza R.; Kastner, Geraldo F.; Temba, Eliane S.C.; Oliveira, Thiago C. de; Amaral, Ângela M.; Franco, Milton B., E-mail: rpgm@cdtn.br, E-mail: reisas@cdtn.br, E-mail: gfk@cdtn.br, E-mail: esct@cdtn.br, E-mail: tco@cdtn.br, E-mail: ama@cdtn.br, E-mail: francom@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    The aim of this work is to present radiochemical methodologies developed at CDTN/CNEN in order to answer a program for isotopic inventory of radioactive wastes from Brazilian Nuclear Power Plants. In this program some radionuclides, {sup 3}H, {sup 14}C, {sup 55}Fe, {sup 59}Ni, {sup 63}Ni, {sup 90}Sr, {sup 93}Zr, {sup 94}Nb, {sup 99}Tc, {sup 129}I, {sup 235}U, {sup 238}U, {sup 238}Pu, {sup 239}+{sup 240}Pu, {sup 241}Pu, {sup 242}Pu, {sup 241}Am, {sup 242}Cm e {sup 243}+{sup 244}Cm, were determined in Low Level Wastes (LLW) and Intermediate Level Wastes (ILW) and a protocol of analytical methodologies based on radiochemical separation steps and spectrometric and nuclear techniques was established. (author)

  11. NiO-NF/MWCNT nanocomposite catalyst as a counter electrode for high performance dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Raissan Al-bahrani, Majid; Liu, Linfeng; Ahmad, Waqar; Tao, Jiayou; Tu, Fanfan; Cheng, Ze; Gao, Yihua

    2015-01-01

    Highlights: • High-performance NiO-NF/MWCNT CE was incorporated in a Pt-CE in DSSCs. • NiO-NF/MWCNT CE exhibits a high power conversion efficiency (PCE) of 7.63%. • NiO-NF/MWCNT composite has a high catalytic activity for the reduction of I 3 − . • NiO-NF/MWCNT composite has a low R ct on the electrolyte/CE interface. - Abstract: In this paper, we fabricated nickel oxide nanofilament/multiwall carbon nanotubes (NiO-NF/MWCNT) nanocomposite by a simple hydrothermal synthesis method as a counter- electrode (CE) in a dye-sensitized solar cell (DSSC). Transmission electron microscopy, scanning electron microscopy images and X-ray diffraction analysis clearly indicated the formation of NiO-NF/MWCNT nanocomposite. The electro-chemical properties of NiO-NF/MWCNT CE are studied by cyclic voltammetry and electrochemical impedance spectroscopy. In particular, current-voltage measurements indicated superior power conversion efficiency (PCE) of 7.63% of the NiO-NF/MWCNT CE compared to 6.72% for the platinum (Pt). The superior photovoltaic performance and low cost of the NiO-NF/MWCNT nanocomposite can be potentially exploited as a new counter-electrode in DSSCs

  12. Development of 63Ni-voltaic nuclear micro-battery prototype

    International Nuclear Information System (INIS)

    Zhang Huaming; Hu Rui; Wang Guanquan; Gao Hui; Liu Guoping; Luo Shunzhong

    2013-01-01

    Crystal silicon based energy-conversion unit was prepared using the parameters from theoretical simulation. A battery prototype was assembled through ascertaining the process of 63 Ni deposition, the formula of sealing materials and the sealing technique. The electric output properties were assessed with accelerating ageing and changing the temperatures. The results show that the open circuit voltage and short circuit current of the manufactured nuclear micro-battery prototype are 88.0 mV and 5.97 nA, and the maximum power output and the energy conversion efficiency are 0.255 nW and 0.561%, respectively. It preserves steadily over 220 days. (authors)

  13. Low-Temperature Electrical Characteristics of Si-Based Device with New Tetrakis NiPc-SNS Active Layer

    Science.gov (United States)

    Yavuz, Arzu Büyükyağci; Carbas, Buket Bezgın; Sönmezoğlu, Savaş; Soylu, Murat

    2016-01-01

    A new tetrakis 4-(2,5-di-2-thiophen-2-yl-pyrrol-1-yl)-substituted nickel phthalocyanine (NiPc-SNS) has been synthesized. This synthesized NiPc-SNS thin film was deposited on p-type Si substrate using the spin coating method (SCM) to fabricate a NiPc-SNS/ p-Si heterojunction diode. The temperature-dependent electrical characteristics of the NiPc-SNS/ p-Si heterojunction with good rectifying behavior were investigated by current-voltage ( I- V) measurements between 50 K and 300 K. The results indicate that the ideality factor decreases while the barrier height increases with increasing temperature. The barrier inhomogeneity across the NiPc-SNS/ p-Si heterojunction reveals a Gaussian distribution at low temperatures. These results provide further evidence of the more complicated mechanisms occurring in this heterojunction. Based on these findings, NiPc-SNS/ p-Si junction diodes are feasible for use in low-temperature applications.

  14. Fabrication of a Cu/Ni stack in supercritical carbon dioxide at low-temperature

    Energy Technology Data Exchange (ETDEWEB)

    Rasadujjaman, Md, E-mail: rasadphy@duet.ac.bd [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511 (Japan); Department of Physics, Dhaka University of Engineering & Technology, Gazipur 1700 (Bangladesh); Watanabe, Mitsuhiro [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511 (Japan); Sudoh, Hiroshi; Machida, Hideaki [Gas-Phase Growth Ltd., 2-24-16 Naka, Koganei, Tokyo 184-0012 (Japan); Kondoh, Eiichi [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511 (Japan)

    2015-09-30

    We report the low-temperature deposition of Cu on a Ni-lined substrate in supercritical carbon dioxide. A novel Cu(I) amidinate precursor was used to reduce the deposition temperature. From the temperature dependence of the growth rate, the activation energy for Cu growth on the Ni film was determined to be 0.19 eV. The films and interfaces were characterized by Auger electron spectroscopy. At low temperature (140 °C), we successfully deposited a Cu/Ni stack with a sharp Cu/Ni interface. The stack had a high adhesion strength (> 1000 mN) according to microscratch testing. The high adhesion strength originated from strong interfacial bonding between the Cu and the Ni. However, at a higher temperature (240 °C), significant interdiffusion was observed and the adhesion became weak. - Highlights: • Cu/Ni stack fabricated in supercritical CO{sub 2} at low temperature. • A novel Cu(I) amidinate precursor was used to reduce the deposition temperature. • Adhesion strength of Cu/Ni stack improved dramatically. • Fabricated Cu/Ni stack is suitable for Cu interconnections in microelectronics.

  15. Low temperature gaseous nitriding of Ni based superalloys

    DEFF Research Database (Denmark)

    Eliasen, K. M.; Christiansen, Thomas Lundin; Somers, Marcel A. J.

    2010-01-01

    In the present work the nitriding response of selected Ni based superalloys at low temperatures is addressed. The alloys investigated are nimonic series nos. 80, 90, 95 and 100 and nichrome (Ni/Cr......In the present work the nitriding response of selected Ni based superalloys at low temperatures is addressed. The alloys investigated are nimonic series nos. 80, 90, 95 and 100 and nichrome (Ni/Cr...

  16. Near-infrared scintillation of xenon by 63Ni beta decay

    Science.gov (United States)

    Yoshimizu, Norimasa; Lal, Amit; Pollock, Clifford R.

    2006-07-01

    The near-infrared scintillation of xenon gas by the β decay of 37MBq of Ni63 was studied, in the interest of its use in integrated devices for applications such as optical beacons and wavelength calibration. The emission was imaged and analyzed using Spencer's theory of electron penetration using xenon scattering cross sections derived from Thomas-Fermi theory. The total emission was approximately 2×105photons/s at 20kPa and 1×105photons/s at 100kPa. Spectral data show three dominant peaks at 823, 828, and 882nm as well as the formation of metastable states.

  17. Model of Ni-63 battery with realistic PIN structure

    Science.gov (United States)

    Munson, Charles E.; Arif, Muhammad; Streque, Jeremy; Belahsene, Sofiane; Martinez, Anthony; Ramdane, Abderrahim; El Gmili, Youssef; Salvestrini, Jean-Paul; Voss, Paul L.; Ougazzaden, Abdallah

    2015-09-01

    GaN, with its wide bandgap of 3.4 eV, has emerged as an efficient material for designing high-efficiency betavoltaic batteries. An important part of designing efficient betavoltaic batteries involves a good understanding of the full process, from the behavior of the nuclear material and the creation of electron-hole pairs all the way through the collection of photo-generated carriers. This paper presents a detailed model based on Monte Carlo and Silvaco for a GaN-based betavoltaic battery device, modeled after Ni-63 as an energy source. The accuracy of the model is verified by comparing it with experimental values obtained for a GaN-based p-i-n structure under scanning electron microscope illumination.

  18. Model of Ni-63 battery with realistic PIN structure

    Energy Technology Data Exchange (ETDEWEB)

    Munson, Charles E.; Voss, Paul L.; Ougazzaden, Abdallah, E-mail: aougazza@georgiatech-metz.fr [Georgia Tech Lorraine, Georgia Tech-C.N.R.S., UMI2958, 2-3 rue Marconi, 57070 Metz (France); School of Electrical and Computer Engineering, Georgia Institute of Technology, 777 Atlantic Drive NW, 30332-0250 Atlanta (United States); Arif, Muhammad; Salvestrini, Jean-Paul [Georgia Tech Lorraine, Georgia Tech-C.N.R.S., UMI2958, 2-3 rue Marconi, 57070 Metz (France); Université de Lorraine, CentraleSupélec, LMOPS, EA 4423, 2 rue E. Belin, 57070 Metz (France); Streque, Jeremy; El Gmili, Youssef [Georgia Tech Lorraine, Georgia Tech-C.N.R.S., UMI2958, 2-3 rue Marconi, 57070 Metz (France); Belahsene, Sofiane; Martinez, Anthony; Ramdane, Abderrahim [Laboratory for Photonics and Nanostructures, CNRS, Route de Nozay, 91460 Marcoussis (France)

    2015-09-14

    GaN, with its wide bandgap of 3.4 eV, has emerged as an efficient material for designing high-efficiency betavoltaic batteries. An important part of designing efficient betavoltaic batteries involves a good understanding of the full process, from the behavior of the nuclear material and the creation of electron-hole pairs all the way through the collection of photo-generated carriers. This paper presents a detailed model based on Monte Carlo and Silvaco for a GaN-based betavoltaic battery device, modeled after Ni-63 as an energy source. The accuracy of the model is verified by comparing it with experimental values obtained for a GaN-based p-i-n structure under scanning electron microscope illumination.

  19. Model of Ni-63 battery with realistic PIN structure

    International Nuclear Information System (INIS)

    Munson, Charles E.; Voss, Paul L.; Ougazzaden, Abdallah; Arif, Muhammad; Salvestrini, Jean-Paul; Streque, Jeremy; El Gmili, Youssef; Belahsene, Sofiane; Martinez, Anthony; Ramdane, Abderrahim

    2015-01-01

    GaN, with its wide bandgap of 3.4 eV, has emerged as an efficient material for designing high-efficiency betavoltaic batteries. An important part of designing efficient betavoltaic batteries involves a good understanding of the full process, from the behavior of the nuclear material and the creation of electron-hole pairs all the way through the collection of photo-generated carriers. This paper presents a detailed model based on Monte Carlo and Silvaco for a GaN-based betavoltaic battery device, modeled after Ni-63 as an energy source. The accuracy of the model is verified by comparing it with experimental values obtained for a GaN-based p-i-n structure under scanning electron microscope illumination

  20. Enhanced Electrocatalytic Activity for Water Splitting on NiO/Ni/Carbon Fiber Paper

    Directory of Open Access Journals (Sweden)

    Ruoyu Zhang

    2016-12-01

    Full Text Available Large-scale growth of low-cost, efficient, and durable non-noble metal-based electrocatalysts for water splitting is crucial for future renewable energy systems. Atomic layer deposition (ALD provides a promising route for depositing uniform thin coatings of electrocatalysts, which are useful in many technologies, including the splitting of water. In this communication, we report the growth of a NiO/Ni catalyst directly on carbon fiber paper by atomic layer deposition and report subsequent reduction and oxidation annealing treatments. The 10–20 nm NiO/Ni nanoparticle catalysts can reach a current density of 10 mA·cm−2 at an overpotential of 189 mV for hydrogen evolution reactions and 257 mV for oxygen evolution reactions with high stability. We further successfully achieved a water splitting current density of 10 mA·cm−2 at 1.78 V using a typical NiO/Ni coated carbon fiber paper two-electrode setup. The results suggest that nanoparticulate NiO/Ni is an active, stable, and noble-metal-free electrocatalyst, which facilitates a method for future water splitting applications.

  1. Electroplating condition for Ni nanocrystalline on metal (Ni and Cu) plates

    Energy Technology Data Exchange (ETDEWEB)

    Park, Keun Yung; Uhm, Young Rang; Son, Kwang Jae; Shim, Young Ho; Choi, Sun Ju [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    Ni 63, a beta radiation source, is prepared by the electrical deposition of radioactive Ni 63 ions on a thin non radioactive nickel foil or Cu plate. Given a half life of 100 years, a nuclear battery will still produce half of its initial starting power after 100 years. A speck of a radioisotope like nickel 63, for example, contains enough energy to power a nano nuclear battery for decades, and to do so safely. Ni 63 plating is similar to other electroplating processes that employ soluble metal anodes. It requires the passage of a direct current between two electrodes that are immersed in a conductive, aqueous solution of nickel salts. The charged Ni ions are formed by sulfate, sulfamate, chloride, and a Watts bath. However, the charged Ni 63 ions are formed by dissolving metal Ni 63. To established the coating condition of Ni 63, non radioactive metal Ni particles are dissolved an acid solution and electroplated on a Ni sheet. The nickel plating process is used extensively for decorative, engineering and electro forming purposes because the appearance and other properties of electrodeposited nickel can be varied over a wide range by controlling the composition and operating parameters of the plating solution. A continuous increase in the grain size versus current density has also been recognized in the direct current electrodeposition of nickel coating. On the other hand, A runa et al. reported that the current density has no significant effect on the grain size of nickel electro deposits. A review of the literature shows that saccharin has often been added to a nickel plating bath since the 1980s to improve the ductility and brightness, and in later periods as a grain refiner agent. In the present paper, not only the preparation of a Ni plating solution prepared by dissolving metal particles, but also an optimization of the deposition conditions, such as the current density, saccharin concentration in the bath, and different metal substrates were investigated

  2. Electroplating condition for Ni nanocrystalline on metal (Ni and Cu) plates

    International Nuclear Information System (INIS)

    Park, Keun Yung; Uhm, Young Rang; Son, Kwang Jae; Shim, Young Ho; Choi, Sun Ju

    2012-01-01

    Ni 63, a beta radiation source, is prepared by the electrical deposition of radioactive Ni 63 ions on a thin non radioactive nickel foil or Cu plate. Given a half life of 100 years, a nuclear battery will still produce half of its initial starting power after 100 years. A speck of a radioisotope like nickel 63, for example, contains enough energy to power a nano nuclear battery for decades, and to do so safely. Ni 63 plating is similar to other electroplating processes that employ soluble metal anodes. It requires the passage of a direct current between two electrodes that are immersed in a conductive, aqueous solution of nickel salts. The charged Ni ions are formed by sulfate, sulfamate, chloride, and a Watts bath. However, the charged Ni 63 ions are formed by dissolving metal Ni 63. To established the coating condition of Ni 63, non radioactive metal Ni particles are dissolved an acid solution and electroplated on a Ni sheet. The nickel plating process is used extensively for decorative, engineering and electro forming purposes because the appearance and other properties of electrodeposited nickel can be varied over a wide range by controlling the composition and operating parameters of the plating solution. A continuous increase in the grain size versus current density has also been recognized in the direct current electrodeposition of nickel coating. On the other hand, A runa et al. reported that the current density has no significant effect on the grain size of nickel electro deposits. A review of the literature shows that saccharin has often been added to a nickel plating bath since the 1980s to improve the ductility and brightness, and in later periods as a grain refiner agent. In the present paper, not only the preparation of a Ni plating solution prepared by dissolving metal particles, but also an optimization of the deposition conditions, such as the current density, saccharin concentration in the bath, and different metal substrates were investigated

  3. NiO-NF/MWCNT nanocomposite catalyst as a counter electrode for high performance dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Raissan Al-bahrani, Majid [Center for Nanoscale Characterization & Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO)-School of Physics, Huazhong University of Science and Technology - HUST, Luoyu Road 1037, Wuhan 430074 (China); Faculty of Science, Thi-Qar University, Nassiriya (Iraq); Liu, Linfeng [Michael Grätzel Center for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074 (China); Ahmad, Waqar; Tao, Jiayou; Tu, Fanfan [Center for Nanoscale Characterization & Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO)-School of Physics, Huazhong University of Science and Technology - HUST, Luoyu Road 1037, Wuhan 430074 (China); Cheng, Ze [School of Physics, Huazhong University of Science and Technology (HUST), Luoyu Road 1037, Wuhan 430074 (China); Gao, Yihua, E-mail: gaoyihua@hust.edu.cn [Center for Nanoscale Characterization & Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO)-School of Physics, Huazhong University of Science and Technology - HUST, Luoyu Road 1037, Wuhan 430074 (China)

    2015-03-15

    Highlights: • High-performance NiO-NF/MWCNT CE was incorporated in a Pt-CE in DSSCs. • NiO-NF/MWCNT CE exhibits a high power conversion efficiency (PCE) of 7.63%. • NiO-NF/MWCNT composite has a high catalytic activity for the reduction of I{sub 3}{sup −}. • NiO-NF/MWCNT composite has a low R{sub ct} on the electrolyte/CE interface. - Abstract: In this paper, we fabricated nickel oxide nanofilament/multiwall carbon nanotubes (NiO-NF/MWCNT) nanocomposite by a simple hydrothermal synthesis method as a counter- electrode (CE) in a dye-sensitized solar cell (DSSC). Transmission electron microscopy, scanning electron microscopy images and X-ray diffraction analysis clearly indicated the formation of NiO-NF/MWCNT nanocomposite. The electro-chemical properties of NiO-NF/MWCNT CE are studied by cyclic voltammetry and electrochemical impedance spectroscopy. In particular, current-voltage measurements indicated superior power conversion efficiency (PCE) of 7.63% of the NiO-NF/MWCNT CE compared to 6.72% for the platinum (Pt). The superior photovoltaic performance and low cost of the NiO-NF/MWCNT nanocomposite can be potentially exploited as a new counter-electrode in DSSCs.

  4. Midcourse Space Experiment (MSX)

    Science.gov (United States)

    1992-08-01

    activities will occur. Krypton and xenon flash lamps in the CE will contain a small amount of low-level Ni63 radioactive element. The Ni63 will serve as...Radiation emitted from Ni63 is small enough (80 microcuries 0*Ci)) to exempt it from Nuclear Regulatory Commission licensing and Department of...MSX mission, and only the small quantity of radioactive material ( Ni63 ) will be aboard and deorbit (PRA, 1992). 2.1.8 Spacecraft Control and Data

  5. Prestudy of final disposal of long-lived low and intermediate level waste

    International Nuclear Information System (INIS)

    Wiborgh, M.

    1995-01-01

    The repository for long-lived low and intermediate level waste, SFL 3-5, is foreseen to be located adjacent to the deep repository for spent encapsulated fuel, SFL 2. The SFL 3-5 repository comprises of three repository parts which will be used for the different categories of waste. In this report the work performed within a pre-study of the SFL 3-5 repository concept is summarised. The aim was to make a first preliminary and simplified assessment of the near-field as a barrier to radionuclide dispersion. A major task has been to compile information on the waste foreseen to be disposed of in SFL 3-5. The waste comprises of; low and intermediate level waste from Studsvik, operational waste from the central interim storage for spent fuel, CLAB, and the encapsulation plant, decommissioning waste from these facilities, and core components and internal parts from the reactors. The total waste volume has been estimated to about 25000 m 3 . The total activity content at repository closure is estimated to be about 1 ·10 17 Bq in SFL 3-5. At repository closure the short-lived radionuclides, for example Co-60 and Fe-55, have decayed considerably and the activity is dominated by nickel isotopes in the metallic waste from the reactors, to be disposed of in SFL 5. However, other radionuclides may be more or equally important from a safety point of view, e.g cesium-isotopes and actinides which are found in largest amounts in the SFL 3 waste. A first evaluation of the long term performance or the SFL 3-5 repository has been made. A systematic methodology for scenario formulation was tested. The near-field release of contaminants was calculated for a selected number of radionuclides and chemo-toxic elements. The radionuclide release calculations revealed that Cs-137 and Ni-63 would dominate the annual release from all repository parts during the first 1000 years after repository closure and that Ni-59 would dominate at longer times

  6. Prestudy of final disposal of long-lived low and intermediate level waste

    Energy Technology Data Exchange (ETDEWEB)

    Wiborgh, M [ed.; Kemakta Konsult AB., Stockholm (Sweden)

    1995-01-01

    The repository for long-lived low and intermediate level waste, SFL 3-5, is foreseen to be located adjacent to the deep repository for spent encapsulated fuel, SFL 2. The SFL 3-5 repository comprises of three repository parts which will be used for the different categories of waste. In this report the work performed within a pre-study of the SFL 3-5 repository concept is summarised. The aim was to make a first preliminary and simplified assessment of the near-field as a barrier to radionuclide dispersion. A major task has been to compile information on the waste foreseen to be disposed of in SFL 3-5. The waste comprises of; low and intermediate level waste from Studsvik, operational waste from the central interim storage for spent fuel, CLAB, and the encapsulation plant, decommissioning waste from these facilities, and core components and internal parts from the reactors. The total waste volume has been estimated to about 25000 m{sup 3}. The total activity content at repository closure is estimated to be about 1 {center_dot}10{sup 17} Bq in SFL 3-5. At repository closure the short-lived radionuclides, for example Co-60 and Fe-55, have decayed considerably and the activity is dominated by nickel isotopes in the metallic waste from the reactors, to be disposed of in SFL 5. However, other radionuclides may be more or equally important from a safety point of view, e.g cesium-isotopes and actinides which are found in largest amounts in the SFL 3 waste. A first evaluation of the long term performance or the SFL 3-5 repository has been made. A systematic methodology for scenario formulation was tested. The near-field release of contaminants was calculated for a selected number of radionuclides and chemo-toxic elements. The radionuclide release calculations revealed that Cs-137 and Ni-63 would dominate the annual release from all repository parts during the first 1000 years after repository closure and that Ni-59 would dominate at longer times.

  7. Analysis of Low Level DNA Mixtures

    Czech Academy of Sciences Publication Activity Database

    Slovák, Dalibor; Zvárová, Jana

    2013-01-01

    Roč. 1, č. 1 (2013), s. 63-63 ISSN 1805-8698. [EFMI 2013 Special Topic Conference. 17.04.2013-19.04.2013, Prague] Institutional support: RVO:67985807 Keywords : forensic DNA interpretation * low level samples * allele peak heights * dropout probability Subject RIV: IN - Informatics, Computer Science

  8. Combining Ru, Ni and Ni(OH){sub 2} active sites for improving catalytic performance in benzene hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Lihua, E-mail: lihuazhu@stu.xmu.edu.cn [School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiang Xi (China); Department of Chemical and Biochemical Engineering, National Engineering Laboratory for Green Productions of Alcohols-Ethers-Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Sun, Hanlei; Zheng, Jinbao [Department of Chemical and Biochemical Engineering, National Engineering Laboratory for Green Productions of Alcohols-Ethers-Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Yu, Changlin, E-mail: yuchanglinjx@163.com [School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiang Xi (China); Zhang, Nuowei [Department of Chemical and Biochemical Engineering, National Engineering Laboratory for Green Productions of Alcohols-Ethers-Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Shu, Qing [School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiang Xi (China); Chen, Bing H., E-mail: chenbh@xmu.edu.cn [Department of Chemical and Biochemical Engineering, National Engineering Laboratory for Green Productions of Alcohols-Ethers-Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China)

    2017-05-01

    In this study, the Ru{sub 0.04}Ni{sub 0.96}/C(T) catalysts were successfully prepared by the simple methods of hydrazine-reduction and galvanic replacement, where 0.04/0.96 and T represented the Ru/Ni atomic ratio and reducing temperature of the catalyst in N{sub 2}+10%H{sub 2}, respectively. The nanostructures of the Ru{sub 0.04}Ni{sub 0.96} nanoparticles in the Ru{sub 0.04}Ni{sub 0.96}/C(T) catalysts were controlled by modulating their annealing temperature in N{sub 2}+10%H{sub 2} and characterized by an array of techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), scanning transmission electron microscopy energy dispersive X-ray spectroscopy (STEM-EDS) mapping and high-sensitivity low-energy ion scattering (HS-LEIS). The Ru{sub 0.04}Ni{sub 0.96}/C(30) catalyst, which was composed of Ru clusters or single atoms supported on Ni/Ni(OH){sub 2} nanoparticles, exhibited much better catalytic performance for benzene hydrogenation than the Ru{sub 0.04}Ni{sub 0.96}/C(T) catalysts reduced at above 30 °C, such as Ru{sub 0.04}Ni{sub 0.96}/C(160) with the nanostructure of partial Ru{sub 0.04}Ni{sub 0.9} alloy and Ru{sub 0.04}Ni{sub 0.96}/C(280) with the nanostructure of complete Ru{sub 0.04}Ni{sub 0.9} alloy. The reason was that the synergistic effect of multiple active sites – Ru, Ni and Ni(OH){sub 2} sites was present in the Ru{sub 0.04}Ni{sub 0.96}/C(30) catalyst, where hydrogen was preferentially activated at Ru sites, benzene was probably activated at Ni(OH){sub 2} surface and Ni acted as a “bridge” for transferring activated H{sup ∗} species to activated benzene by hydrogen spillover effect, hydrogenating and forming product – cyclohexane. This study also provided a typical example to illustrate that the synergy effect of multiple active sites can largely improve the catalytic hydrogenation performance. - Highlights: • The Ru

  9. Beta-electric power supply based in nickel-63

    International Nuclear Information System (INIS)

    Pustovalov, A.A.; Gusev, V.V.; Zaddeh, V.V.; Petrenko, N.S.; Tsvetkov, L.A.; Tikhomiorov, A.V.

    2007-01-01

    One analyzes the possibility to design 63 Ni base β-electric microwatt atomic battery expected to serve minimum 30 years. One proposes a process to ensure the full-scale commercial production of 63 Ni with 80-90% concentration in the end product. One presents and analyzes the design of a microporous silicon base β-electric converter with the optimized configuration and depth of micropores (microchannels). 63 Ni is coated on the microchannel inner surface. 63 Ni base atomic battery laboratory mock-up is available. Paper lists the design parameters and the volt-ampere characteristics of 500 microwatt capacity 63 Ni (of 90% concentration) base atomic battery [ru

  10. Ni62(n,γ) and Ni63(n,γ) cross sections measured at the n_TOF facility at CERN

    Science.gov (United States)

    Lederer, C.; Massimi, C.; Berthoumieux, E.; Colonna, N.; Dressler, R.; Guerrero, C.; Gunsing, F.; Käppeler, F.; Kivel, N.; Pignatari, M.; Reifarth, R.; Schumann, D.; Wallner, A.; Altstadt, S.; Andriamonje, S.; Andrzejewski, J.; Audouin, L.; Barbagallo, M.; Bécares, V.; Bečvář, F.; Belloni, F.; Berthier, B.; Billowes, J.; Boccone, V.; Bosnar, D.; Brugger, M.; Calviani, M.; Calviño, F.; Cano-Ott, D.; Carrapiço, C.; Cerutti, F.; Chiaveri, E.; Chin, M.; Cortés, G.; Cortés-Giraldo, M. A.; Dillmann, I.; Domingo-Pardo, C.; Duran, I.; Dzysiuk, N.; Eleftheriadis, C.; Fernández-Ordóñez, M.; Ferrari, A.; Fraval, K.; Ganesan, S.; García, A. R.; Giubrone, G.; Gómez-Hornillos, M. B.; Gonçalves, I. F.; González-Romero, E.; Gramegna, F.; Griesmayer, E.; Gurusamy, P.; Harrisopulos, S.; Heil, M.; Ioannides, K.; Jenkins, D. G.; Jericha, E.; Kadi, Y.; Karadimos, D.; Korschinek, G.; Krtička, M.; Kroll, J.; Langer, C.; Lebbos, E.; Leeb, H.; Leong, L. S.; Losito, R.; Lozano, M.; Manousos, A.; Marganiec, J.; Marrone, S.; Martinez, T.; Mastinu, P. F.; Mastromarco, M.; Meaze, M.; Mendoza, E.; Mengoni, A.; Milazzo, P. M.; Mingrone, F.; Mirea, M.; Mondalaers, W.; Paradela, C.; Pavlik, A.; Perkowski, J.; Plag, R.; Plompen, A.; Praena, J.; Quesada, J. M.; Rauscher, T.; Riego, A.; Roman, F.; Rubbia, C.; Sarmento, R.; Schillebeeckx, P.; Schmidt, S.; Tagliente, G.; Tain, J. L.; Tarrío, D.; Tassan-Got, L.; Tsinganis, A.; Tlustos, L.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Vermeulen, M. J.; Versaci, R.; Vlachoudis, V.; Vlastou, R.; Ware, T.; Weigand, M.; Weiß, C.; Wright, T. J.; Žugec, P.; n TOF Collaboration

    2014-02-01

    The cross section of the Ni62(n,γ) reaction was measured with the time-of-flight technique at the neutron time-of-flight facility n_TOF at CERN. Capture kernels of 42 resonances were analyzed up to 200 keV neutron energy and Maxwellian averaged cross sections (MACS) from kT = 5-100 keV were calculated. With a total uncertainty of 4.5%, the stellar cross section is in excellent agreement with the the KADoNiS compilation at kT=30 keV, while being systematically lower up to a factor of 1.6 at higher stellar temperatures. The cross section of the Ni63(n ,γ) reaction was measured for the first time at n_TOF. We determined unresolved cross sections from 10 to 270 keV with a systematic uncertainty of 17%. These results provide fundamental constraints on s-process production of heavier species, especially the production of Cu in massive stars, which serve as the dominant source of Cu in the solar system.

  11. Hydrodeoxygenation of prairie cordgrass bio-oil over Ni based activated carbon synergistic catalysts combined with different metals.

    Science.gov (United States)

    Cheng, Shouyun; Wei, Lin; Zhao, Xianhui; Kadis, Ethan; Cao, Yuhe; Julson, James; Gu, Zhengrong

    2016-06-25

    Bio-oil can be upgraded through hydrodeoxygenation (HDO). Low-cost and effective catalysts are crucial for the HDO process. In this study, four inexpensive combinations of Ni based activated carbon synergistic catalysts including Ni/AC, Ni-Fe/AC, Ni-Mo/AC and Ni-Cu/AC were evaluated for HDO of prairie cordgrass (PCG) bio-oil. The tests were carried out in the autoclave under mild operating conditions with 500psig of H2 pressure and 350°C temperature. The catalysts were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and transmission electron microscope (TEM). The results show that all synergistic catalysts had significant improvements on the physicochemical properties (water content, pH, oxygen content, higher heating value and chemical compositions) of the upgraded PCG bio-oil. The higher heating value of the upgraded bio-oil (ranging from 29.65MJ/kg to 31.61MJ/kg) improved significantly in comparison with the raw bio-oil (11.33MJ/kg), while the oxygen content reduced to only 21.70-25.88% from 68.81% of the raw bio-oil. Compared to raw bio-oil (8.78% hydrocarbons and no alkyl-phenols), the Ni/AC catalysts produced the highest content of gasoline range hydrocarbons (C6-C12) at 32.63% in the upgraded bio-oil, while Ni-Mo/AC generated the upgraded bio-oil with the highest content of gasoline blending alkyl-phenols at 38.41%. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Active Crohn's disease is associated with low vitamin D levels

    DEFF Research Database (Denmark)

    Jørgensen, Søren Peter; Hvas, Christian Lodberg; Agnholt, Jørgen

    2013-01-01

    activity is associated with low vitamin D levels. METHODS: In a cross-sectional study of 182 CD patients and 62 healthy controls, we measured serum 25-OH vitamin D. Stratified analysis was used to compare 25-OH vitamin D levels with Crohn's disease activity index, C-reactive protein, smoking status, intake...... of oral vitamin D supplements and seasonal variation in CD patients and healthy controls. RESULTS: Serum 25-OH vitamin D was inversely associated with disease activity: Median 25-OH vitamin D levels of Crohn's disease in remission, mildly, and moderately active diseases evaluated by Crohn's disease...... D levels (51nmol/l) than patients who did not smoke (76nmol/l), plevels. CONCLUSIONS: Active Crohn's disease was associated with low serum 25-OH vitamin D. Patients who smoked had lower 25-OH...

  13. Actively shielded low level gamma - spectrometric system

    International Nuclear Information System (INIS)

    Mrdja, D.; Bikit, I.; Forkapic, S.; Slivka, J.; Veskovic, M.

    2005-01-01

    The results of the adjusting and testing of the actively shielded low level gamma-spectrometry system are presented. The veto action of the shield reduces the background in the energy region of 50 keV to the 2800 keV for about 3 times. (author) [sr

  14. Application of Ni-63 photo and corona discharge ionization for the analysis of chemical warfare agents and toxic wastes

    Science.gov (United States)

    Stach, J.; Adler, J.; Brodacki, M.; Doring, H.-R.

    1995-01-01

    Over the past decade, advances in instrumental design and refinements in the understanding of ion molecule reactions at atmospheric pressure enabled the application of Ion Mobility Spectrometry (IMS) as a simple inexpensive and sensitive analytical method for the detection of organic trace compounds. Positive and negative gas-phase ions for ion mobility spectrometry have been produced by a variety of methods, including photo-ionization, laser multi photon ionization, surface ionization, corona discharge ionization. The most common ion source used in ion mobility spectrometry is a radioactive Ni-63 foil which is favored due to simplicity, stability, convenience, and high selectivity. If reactant ions like (H2O(n)H)(+) or (H2O(n)O2)(-) dominate in the reaction region, nearly all kinds of compounds with a given proton or electron affinity; are ionized. However, the radioactivity of the Ni-63 foil is one disadvantage of this ion source that stimulates the development and application of other ionization techniques. In this paper, we report analyses of old chemical warfare agents and toxic wastes using Bruker RAID ion mobility spectrometers. Due to the modular construction of the measuring cell, the spectrometers can be equipped with different ion sources. The combined use of Ni-63, photo- and corona discharge ionization allows the identification of different classes of chemical compounds and yields in most cases comparable results.

  15. Low Temperature Steam Methane Reforming Over Ni Based Catalytic Membrane Prepared by Electroless Palladium Plating.

    Science.gov (United States)

    Lee, Sang Moon; Hong, Sung Chang; Kim, Sung Su

    2018-09-01

    A Pd/Ni-YSZ porous membrane with different palladium loadings and hydrazine as a reducing reagent was prepared by electroless plating and evaluated for the steam methane reforming activity. The steam-reforming activity of a Ni-YSZ porous membrane was greatly increased by the deposition of 4 g/L palladium in the low-temperature range (600 °C). With an increasing amount of reducing reagent, the Pd clusters were well dispersed on the Ni-YSZ surface and were uniform in size (∼500 nm). The Pd/Ni-YSZ catalytic porous membrane prepared by 1 of Pd/hydrazine ratio possessed an abundant amount of metallic Pd. The optimal palladium loadings and Pd/hydrazine ratio increased the catalytic activity in both the steam-reforming reaction and the Pd dispersion.

  16. Influence of ni addition to a low-loaded palladium catalyst on the selective hydrogenation of 1-heptyne

    Directory of Open Access Journals (Sweden)

    Cecilia R. Lederhos

    2010-01-01

    Full Text Available Semi-hydrogenation of alkynes has industrial and academic relevance on a large scale. To increase the activity, selectivity and lifetime of monometallic catalysts, the development of bimetallic catalysts has been investigated. 1-Heptyne hydrogenation over low-loaded Pd and Ni monometallic and PdNi bimetallic catalysts was studied in liquid phase at mild conditions. XPS results suggest that nickel addition to Pd modifies the electronic state of palladium as nickel loading is increased. Low-loaded Pd catalysts showed the highest selectivities (> 95%. The most active prepared catalyst, PdNi(1%, was more selective than the Lindlar catalyst.

  17. Low energy structure of even-even Ni isotopes close to 78Ni

    International Nuclear Information System (INIS)

    Rykaczewski, Krzysztof Piotr; Mazzocchi, C.; Grzywacz, Robert Kazimierz; Batchelder, J.C.; Bingham, Carrol R.; Fong, D.; Hamilton, J.H.; Hwang, J.K.; Karny, M.; Krolas, W.; Liddick, S.N.; Lisetskiy, A. F.; Morton, N.H.; Mantica, P.F.; Mueller, W.F.; Steiner, M.; Stolz, A.; Winger, J.A.

    2005-01-01

    The structure of magic neutron-rich nickel isotopes produced in the fragmentation of a 140 A MeV 86 Kr beam was investigated. For the first time four gamma transitions were assigned to the decay of the I π =8 + , T 1/2 = 590 +180 -110 isomer, thus establishing the 0 + -2 + -4 + -6 + -8 + ground-state band in 76 Ni. The previously unknown 2 + and 4 + levels belonging to the ground-state band in 74 Ni were identified in the β decay of 74 Co (T 1/2 =30(3) ms). The decay properties of 72 Co → 72 Ni were verified and confirmed on the basis of γ-γ coincidence data. The relevance of the measured level properties for the magicity of 78 Ni is analyzed with the help of advanced shell-model predictions

  18. Potential low-level waste disposal limits for activation products from fusion

    International Nuclear Information System (INIS)

    Kennedy, W.E. Jr.; Peloquin, R.A.

    1983-09-01

    Hanford Engineering Development Laboratory (HEDL) scientists are involved in studies considering alternative construction materials for the first wall of commercial fusion reactors. To permit a comparison of radioactivity levels, both the level of activation and an acceptable limit for the radionuclides present must be known. Generic material composition guidelines can be developed using the US Nuclear Regulatory Commission (NRC) regulations governing the near-surface disposal of low-level radioactive wastes. These regulations consider wastes defined as containing source, special nuclear, or by-product materials arising from research, industrial, medical, and nuclear fuel-cycle activities. However, not all of the activation products produced in low-level wastes from fusion reactors are considered by the NRC in their regulations. The purpose of this report is to present potential low-level waste-disposal limits for ten radionuclides resulting from fusion reactor operations that are not considered in the NRC low-level waste regulations. These potential limits will be used by HEDL scientists to complete their generic material composition guidelines for the first wall of commercial fusion reactors

  19. Do low levels of physical activity in female adolescents cause ...

    African Journals Online (AJOL)

    Recently Mokabane et al. asserted that black female periurban adolescents exhibited low levels of physical activity and high levels of sedentary behaviour, and that there is a causal, unidirectional, inverse relationship between physical activity and adiposity.[1] However, contrary to their conclusions, the data they presented ...

  20. Modeling, design, fabrication and experimentation of a GaN-based, 63Ni betavoltaic battery

    Science.gov (United States)

    E Munson, C., IV; Gaimard, Q.; Merghem, K.; Sundaram, S.; Rogers, D. J.; de Sanoit, J.; Voss, P. L.; Ramdane, A.; Salvestrini, J. P.; Ougazzaden, A.

    2018-01-01

    GaN is a durable, radiation hard and wide-bandgap semiconductor material, making it ideal for usage with betavoltaic batteries. This paper describes the design, fabrication and experimental testing of 1 cm2 GaN-based betavoltaic batteries (that achieve an output power of 2.23 nW) along with a full model that accurately simulates the device performance which is the highest to date (to the best of our knowledge) for GaN-based devices with a 63Ni source.

  1. Level density of radioactive doubly-magic nucleus 56Ni

    International Nuclear Information System (INIS)

    Santhosh Kumar, S.; Rengaiyan, R.; Victor Babu, A.; Preetha, P.

    2012-01-01

    In this work the single particle energies are obtained by diagonalising the Nilsson Hamiltonian in the cylindrical basis and are generated up to N =11 shells for the isotopes of Ni from A = 48-70, emphasizing the three magic nuclei viz, 48 Ni, 56 Ni and 68 Ni. The statistical quantities like excitation energy, level density parameter and nuclear level density which play the important roles in the nuclear structure and nuclear reactions can be calculated theoretically by means of the Statistical or Partition function method. Hence the statistical model approach is followed to probe the dynamical properties of the nucleus in the microscopic level

  2. CO2 activation on bimetallic CuNi nanoparticles

    Directory of Open Access Journals (Sweden)

    Natalie Austin

    2016-10-01

    Full Text Available Density functional theory calculations have been performed to investigate the structural, electronic, and CO2 adsorption properties of 55-atom bimetallic CuNi nanoparticles (NPs in core-shell and decorated architectures, as well as of their monometallic counterparts. Our results revealed that with respect to the monometallic Cu55 and Ni55 parents, the formation of decorated Cu12Ni43 and core-shell Cu42Ni13 are energetically favorable. We found that CO2 chemisorbs on monometallic Ni55, core-shell Cu13Ni42, and decorated Cu12Ni43 and Cu43Ni12, whereas, it physisorbs on monometallic Cu55 and core-shell Cu42Ni13. The presence of surface Ni on the NPs is key in strongly adsorbing and activating the CO2 molecule (linear to bent transition and elongation of C˭O bonds. This activation occurs through a charge transfer from the NPs to the CO2 molecule, where the local metal d-orbital density localization on surface Ni plays a pivotal role. This work identifies insightful structure-property relationships for CO2 activation and highlights the importance of keeping a balance between NP stability and CO2 adsorption behavior in designing catalytic bimetallic NPs that activate CO2.

  3. Magnetocaloric Properties of Fe-Ni-Cr Nanoparticles for Active Cooling

    Science.gov (United States)

    Chaudhary, V.; Ramanujan, R. V.

    2016-10-01

    Low cost, earth abundant, rare earth free magnetocaloric nanoparticles have attracted an enormous amount of attention for green, energy efficient, active near room temperature thermal management. Hence, we investigated the magnetocaloric properties of transition metal based (Fe70Ni30)100-xCrx (x = 1, 3, 5, 6 and 7) nanoparticles. The influence of Cr additions on the Curie temperature (TC) was studied. Only 5% of Cr can reduce the TC from ~438 K to 258 K. These alloys exhibit broad entropy v/s temperature curves, which is useful to enhance relative cooling power (RCP). For a field change of 5 T, the RCP for (Fe70Ni30)99Cr1 nanoparticles was found to be 548 J-kg-1. Tunable TCin broad range, good RCP, low cost, high corrosion resistance and earth abundance make these nanoparticles suitable for low-grade waste heat recovery as well as near room temperature active cooling applications.

  4. Is the low level of physical activity a public policy issue?

    Directory of Open Access Journals (Sweden)

    Kalman Michal

    2013-03-01

    Full Text Available BACKGROUND: Many studies and scientific evidence confirm a positive effect of physical activity on the quality of life and human health. Physical activity, which is also one of the key factors preventing mass non-communicable diseases, is decreasing in Europe, including the Czech Republic, both in children and adults. Serious health consequences for the population and economy of the countries are a reason for a discussion about including the low level of physical activity among public policy issues and a higher allocation of public sources into the area of physical activity promotion. OBJECTIVES: The main objective of the paper is to determine whether the low level of physical activity is a public policy issue. An issue that should by systematically addressed by national, regional as well as local policy. METHODS: Through the policy analysis approach we conducted a content analysis of 25 systematically selected foreign national strategies aimed at the issue of physical activity promotion. The data source was an internal database of the World Health Organization - the International Inventory of Documents on Physical Activity Promotion. The content analysis of the strategies was performed using the Atlas.ti software tool. RESULTS: During a content analysis of 25 foreign strategies a total of 411 text segments (quotations relating to the low level of physical activity were selected. These text segments showed five basic features of a public policy issue according to a conceptual framework developed by Bardach (2000 and Patton and Sawicky (1993 - 1 affects the lives of a significant number of people of a society; 2 is analysable; 3 can be solved through public policy tools; 4 the primary cause or problem can be defined; 5 cannot be solved easily and quickly. CONCLUSIONS: The results indicate that the low level of physical activity is a public policy issue that must be systematically addressed at national level.

  5. Low-field spin dynamics of Cr7Ni and Cr7Ni-Cu -Cr 7Ni molecular rings as detected by μ SR

    Science.gov (United States)

    Sanna, S.; Arosio, P.; Bordonali, L.; Adelnia, F.; Mariani, M.; Garlatti, E.; Baines, C.; Amato, A.; Sabareesh, K. P. V.; Timco, G.; Winpenny, R. E. P.; Blundell, S. J.; Lascialfari, A.

    2017-11-01

    Muon spin rotation measurements were used to investigate the spin dynamics of heterometallic Cr7Ni and Cr7Ni -Cu-Cr7Ni molecular clusters. In Cr7Ni the magnetic ions are arranged in a quasiplanar ring and interact via an antiferromagnetic exchange coupling constant J , while Cr7Ni -Cu-Cr7Ni is composed of two Cr7Ni linked by a bridging moiety containing one Cu ion, that induces an inter-ring ferromagnetic interaction J'≪J . The longitudinal muon relaxation rate λ collected at low magnetic fields μ0H BPP)-like heuristic fitting model that takes into account of a distribution of electronic spin characteristic times for T >5 K, while the shoulder presented by Cr7Ni can be reproduced by a BPP function that incorporates a single electronic characteristic time theoretically predicted to dominate for T <5 K. The flattening of λ (T ) in Cr7Ni -Cu-Cr7Ni occurring at very low temperature can be tentatively attributed to field-dependent quantum effects and/or to an inelastic term in the spectral density of the electronic spin fluctuations.

  6. Low level beta-activity radiometer with compensation of the background

    Energy Technology Data Exchange (ETDEWEB)

    Vankov, I [and others

    1996-12-31

    New type of the low level beta-activity scintillation detector system is developed. The procedure of finding the beta activity and the operation of the recording unit of the radiometer are considered. 3 refs.; 5 figs.

  7. CuNi NPs supported on MIL-101 as highly active catalysts for the hydrolysis of ammonia borane

    Science.gov (United States)

    Gao, Doudou; Zhang, Yuhong; Zhou, Liqun; Yang, Kunzhou

    2018-01-01

    The catalysts containing Cu, Ni bi-metallic nanoparticles were successfully synthesized by in-situ reduction of Cu2+ and Ni2+ salts into the highly porous and hydrothermally stable metal-organic framework MIL-101 via a simple liquid impregnation method. When the total amount of loading metal is 3 × 10-4 mol, Cu2Ni1@MIL-101 catalyst shows higher catalytic activity comparing to CuxNiy@MIL-101 with different molar ratio of Cu and Ni (x, y = 0, 0.5, 1.5, 2, 2.5, 3). Cu2Ni1@MIL-101 catalyst has the highest catalytic activity comparing to mono-metallic Cu and Ni counterparts and pure bi-metallic CuNi nanoparticles in hydrolytic dehydrogeneration of ammonia borane (AB) at room temperature. Additionally, in the hydrolysis reaction, the Cu2Ni1@MIL- 101 catalyst possesses excellent catalytic performances, which exhibit highly catalytic activity with turn over frequency (TOF) value of 20.9 mol H2 min-1 Cu mol-1 and a very low activation energy value of 32.2 kJ mol-1. The excellent catalytic activity has been successfully achieved thanks to the strong bi-metallic synergistic effects, uniform distribution of nanoparticles and the bi-functional effects between CuNi nanoparticles and the host of MIL-101. Moreover, the catalyst also displays satisfied durable stability after five cycles for the hydrolytically releasing H2 from AB. The non-noble metal catalysts have broad prospects for commercial applications in the field of hydrogen-stored materials due to the low prices and excellent catalytic activity.

  8. Changes in the binding of concanavalin A after mouse lymphocyte activation

    Energy Technology Data Exchange (ETDEWEB)

    Draber, P; Draber, P [Czechoslovak Academy of Sciences, Prague. Institute of Molecular Genetics

    1982-01-01

    Binding /sup 63/Ni-concanavalin A (/sup 63/Ni-Con A) to the cell surface of freshly prepared (non-activated) and Con A-activated spleen cells and the inhibitory effect of pea lectin (PsA) on this binding was investigated. Binding of /sup 63/Ni-Con A to activated cells was much greater as compared with non-activated cells. In the presence of PsA the binding of /sup 63/Ni-Con A was inhibited. 51% of non-activated cells, 3a% of Con A-activated cells and 7 to 14% of permanently transformed cells (myeloma cells NS-1, cells of sarcoma Sa-1 and fibroblasts L-A9) were inhibited by PsA. The results indicate changes (either qualitative or topographic) in the binding sites for Con A in the course of cell activation.

  9. 40 CFR 141.63 - Maximum contaminant levels (MCLs) for microbiological contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels (MCLs) for microbiological contaminants. 141.63 Section 141.63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.63 Maximum...

  10. Micro-structural characterization of low resistive metallic Ni germanide growth on annealing of Ni-Ge multilayer

    Directory of Open Access Journals (Sweden)

    Mitali Swain

    2015-07-01

    Full Text Available Nickel-Germanides are an important class of metal semiconductor alloys because of their suitability in microelectronics applications. Here we report successful formation and detailed characterization of NiGe metallic alloy phase at the interfaces of a Ni-Ge multilayer on controlled annealing at relatively low temperature ∼ 250 °C. Using x-ray and polarized neutron reflectometry, we could estimate the width of the interfacial alloys formed with nanometer resolution and found the alloy stoichiometry to be equiatomic NiGe, a desirable low-resistance interconnect. We found significant drop in resistance (∼ 50% on annealing the Ni-Ge multilayer suggesting metallic nature of alloy phase at the interfaces. Further we estimated the resistivity of the alloy phase to be ∼ 59μΩ cm.

  11. State and Federal activities on low-level waste

    International Nuclear Information System (INIS)

    1983-01-01

    With the passage of the Low-Level Waste Policy Act in December 1980, the states have assumed the management responsibility and the federal government has become a facilitator. State and Federal roles in regulation have not altered. This paper reviews the developments over the last two years to point out the progress made and critical steps that lie ahead. Both technological and political aspects are covered, and a conclusion is presented with a look to the future. Since compact development in the tool chosen by the politicans for low-level waste management, the author reviews the present status starting with the northwest compact which has been introduced into the House and Senate and is subject to hearings. The past two years have seen real progress in technology in the broadest sense. An information development and dissemination system was established in 1978 wih the state-by-state assessment of low-level waste disposal. Annual examinations have been made through 1981 which enables one to understand the generation of low-level wastes. Policy level planning by states can be supported by the base level of information available. Incineration of dry active waste and other non-fuel cycle waste is ready to be fully accepted. Much work has been done on volume reduction of liquids. The increased understanding of the ways to make a disposal site work represents a major technolological improvement. Within the DOE system, there is beginning to be a real understanding of the critical parameters in disposal site performance in the East

  12. Green synthesis of Ni-Nb oxide catalysts for low-temperature oxidative dehydrogenation of ethane

    KAUST Repository

    Zhu, Haibo

    2015-03-05

    The straightforward solid-state grinding of a mixture of Ni nitrate and Nb oxalate crystals led to, after mild calcination (T<400°C), nanostructured Ni-Nb oxide composites. These new materials efficiently catalyzed the oxidative dehydrogenation (ODH) of ethane to ethylene at a relatively low temperature (T<300°C). These catalysts appear to be much more stable than the corresponding composites prepared by other chemical methods; more than 90% of their original intrinsic activity was retained after 50h with time on-stream. Furthermore, the stability was much less affected by the Nb content than in composites prepared by classical "wet" syntheses. These materials, obtained in a solvent-free way, are thus promising green and sustainable alternatives to the current Ni-Nb candidates for the low-temperature ODH of ethane.

  13. Analysis of neonicotinoids by gas chromatography coupled to nuclide 63Ni - Electron Capture Detector - GC/ECD

    International Nuclear Information System (INIS)

    Amaral, Priscila O.; Leao, Claudio; Redigolo, Marcelo M.; Crepaldi, Caike; Bustillos, Oscar V.

    2015-01-01

    Recently, several reports have been published discussing reduction in bee population which polymerizes cultures around the world this phenomenon is known as Colony Collapse Disorder (CCD). The phenomenon describes the lack of worker honeybees in the colony despite having pups and food. The causes of this problem are unknown but there are studies that claim that reduction of population of bees is linked to poisoning through insecticides specifically neonicotinoids. Among this type of pesticide are imidacloprid (C 9 H 10 ClN 5 O 2 ), clothianidin (C 6 H 8 ClN 5 O 2 S) and thiamethoxam (C 8 H 10 ClN 5 O 3 S). This paper presents the analysis of neonicotinoids - clothianidin, imidacloprid and thiamethoxam - by the technique of gas chromatography coupled to nuclide 63 Ni electron capture detector (GC/ECD). The electron capture detector (ECD) is a gas chromatography detector that has been used for the detection of organic halogens, nitriles, nitrates and organometallic compounds. The ECD detector ionizes the analytes by the beta particles from the nuclide sources 63 Ni within carrier gas N 2 . The electrons produced in this process are collected and create a current that are amplified and generates a chromatographic peak. Methodology and details of the analysis are present in this work. (author)

  14. Recovery and purification of nickel-63 from HFIR-irradiated targets

    International Nuclear Information System (INIS)

    Williams, D.F.; O'Kelley, G.D.; Knauer, J.B.; Porter, C.E.; Wiggins, J.T.

    1993-06-01

    The production of large quantities of high-specific-activity 63 Ni (>10 Ci/g) requires both a highly enriched 62 Ni target and a long irradiation period at high neutron flux. Trace impurities in the nickel and associated target materials are also activated and account for a significant fraction of the discharged activity and essentially all of the gamma activity. While most of these undesirable activation products can be removed as chloride complexes during anion exchange, chromium, present at 51 Cr, and scandium, present as 46 Sc, are exceptions and require additional processing to achieve the desired purity. Optimized flowsheets are discussed based upon the current development and production experience

  15. Improved ethanol electrooxidation performance by shortening Pd-Ni active site distance in Pd-Ni-P nanocatalysts

    Science.gov (United States)

    Chen, Lin; Lu, Lilin; Zhu, Hengli; Chen, Yueguang; Huang, Yu; Li, Yadong; Wang, Leyu

    2017-01-01

    Incorporating oxophilic metals into noble metal-based catalysts represents an emerging strategy to improve the catalytic performance of electrocatalysts in fuel cells. However, effects of the distance between the noble metal and oxophilic metal active sites on the catalytic performance have rarely been investigated. Herein, we report on ultrasmall (~5 nm) Pd-Ni-P ternary nanoparticles for ethanol electrooxidation. The activity is improved up to 4.95 A per mgPd, which is 6.88 times higher than commercial Pd/C (0.72 A per mgPd), by shortening the distance between Pd and Ni active sites, achieved through shape transformation from Pd/Ni-P heterodimers into Pd-Ni-P nanoparticles and tuning the Ni/Pd atomic ratio to 1:1. Density functional theory calculations reveal that the improved activity and stability stems from the promoted production of free OH radicals (on Ni active sites) which facilitate the oxidative removal of carbonaceous poison and combination with CH3CO radicals on adjacent Pd active sites.

  16. Coral-like CeO{sub 2}/NiO nanocomposites with efficient enzyme-mimetic activity for biosensing application

    Energy Technology Data Exchange (ETDEWEB)

    Mu, Jianshuai; Zhao, Xin; Li, Jie [College of Chemistry, Key Laboratory of Inorganic-Organic Hybrid Functional Material Chemistry, Ministry of Education, Tianjin Key Laboratory of Structure and Performance for Functional Molecules, Tianjin Normal University, Tianjin 300387 (China); Yang, En-Cui, E-mail: encui_yang@163.com [College of Chemistry, Key Laboratory of Inorganic-Organic Hybrid Functional Material Chemistry, Ministry of Education, Tianjin Key Laboratory of Structure and Performance for Functional Molecules, Tianjin Normal University, Tianjin 300387 (China); Zhao, Xiao-Jun, E-mail: xiaojun_zhao15@163.com [College of Chemistry, Key Laboratory of Inorganic-Organic Hybrid Functional Material Chemistry, Ministry of Education, Tianjin Key Laboratory of Structure and Performance for Functional Molecules, Tianjin Normal University, Tianjin 300387 (China); Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300071 (China)

    2017-05-01

    Development of nanomaterials-based enzymatic mimics has gained considerable attention in recent years, because of their low cost, high stability and efficiently catalytic ability. Here, CeO{sub 2} was successfully incorporated into the coral-like NiO nanostructures assembled by nanoflakes with high surface area, forming the coral-like CeO{sub 2}/NiO nanocomposites. The morphology and composition of CeO{sub 2}/NiO nanocomposites were characterized by XRD, SEM, element mapping and XPS. The results of characterization showed that cerium was highly dispersed in the coral-like NiO nanostructures. The peroxidase-like activity of CeO{sub 2}/NiO nanocomposites was investigated, and they exhibited enhanced peroxidase-like activity in comparison to that of pure NiO or CeO{sub 2}. The catalytic activity was dependent on the cerium content, and the optimal content was 2.5%. The enhanced catalytic activity of CeO{sub 2}/NiO nanocomposites arised from their high ability of electron transfer because of cerium incorporation. The catalytic performance of CeO{sub 2}/NiO nanocomposites was evaluated by steady-state kinetic, which showed that the CeO{sub 2}/NiO nanocomposites exhibited higher affinity for the substrates and similar catalytic efficiency compared with natural peroxidase. Based on the efficient peroxidase-like activity, CeO{sub 2}/NiO was used for H{sub 2}O{sub 2} determination. The constructed colorimetric H{sub 2}O{sub 2} sensor had fast response for only 5 min, a wide linear range from 0.05 to 40 mM and a low detection limit with 0.88 μM. The CeO{sub 2}/NiO nanocomposites were expected to have potential applications in clinical diagnosis and biotechnology as enzymatic mimics. - Highlights: • Coral-like CeO{sub 2}/NiO nanocomposites with different Ce content were synthesized. • CeO{sub 2} was highly dispersed in the NiO matrixes with high surface area. • CeO{sub 2}/NiO nanocomposites exhibited efficient peroxidase-like activity. • A colorimetric H{sub 2}O

  17. Separation and preparation of "6"2Ni isotope

    International Nuclear Information System (INIS)

    Ren Xiuyan; Mi Yajing; Zeng Ziqiang; Li Gongliang; Tu Rui

    2014-01-01

    Micro nuclear battery is the perfect power of space craft equipment. "6"3Ni is the core operation material of the "6"3Ni battery. It can produce radioisotope "6"3Ni while high abundance "6"2Ni is irradiated in the reactor. In order to meet the requirements of the abundance and the purity, research of the separation for "6"2Ni isotope was developed. The magnetic field and beam transmission status were simulated. The improvement designs of the ion source and the collector pocket were carried out. The process flow of high abundance "6"2Ni using electromagnetic separation method was established. The experiment of "6"2Ni isotope was developed by using electromagnetism isotope separator. The results show that the enrichment of "6"2Ni isotope is more than 90%. (authors)

  18. Interannual sea level variability in the Pearl River Estuary and its response to El Niño-Southern Oscillation

    Science.gov (United States)

    Wang, Linlin; Li, Qiang; Mao, Xian-zhong; Bi, Hongsheng; Yin, Peng

    2018-03-01

    The South China coast, especially the Pearl River Estuary (PRE) region, is prosperous and densely populated, but vulnerable to sea level changes. Sea level anomalies (SLA) during 1954-2012 from tide gauge station data and regional SLAs during 1993-2012 from satellite altimetry are analyzed and compare to the El Niño-Southern Oscillation (ENSO). Results show that sea level declines during El Niño events and rises during La Niña. Sea level in the PRE responds to ENSO with 3-month lag. The ENSO can cause sea level in the PRE to fluctuate from -8.70 to 8.11 cm. Sea level cycles of 3 and 5 years are related to ENSO. The ENSO mechanism affecting sea level in the PRE was analyzed by identifying dominant regional and local forces. Weak/strong SLAs in most El Niño/La Niña events may be attributed to less/more seawater transport driven by anomalously weak/strong north winds and local anomalously high/low sea level pressure. Wind-driven coastal current is the predominant factor. It generated coastal seawater volume transport along a 160 km wide cross section to decrease by 21.07% in a typical El Niño period (January 2010) and increase by 44.03% in a typical La Niña period (January 2011) as compared to an ENSO neutral situation (January 2013). Results of sea level rise and its potential mechanism provide insight for disaster protection during extreme El Niño/La Niña events.

  19. Ni3S2 nanowires grown on nickel foam as an efficient bifunctional electrocatalyst for water splitting with greatly practical prospects

    Science.gov (United States)

    Zhang, Dawei; Li, Jingwei; Luo, Jiaxian; Xu, Peiman; Wei, Licheng; Zhou, Dan; Xu, Weiming; Yuan, Dingsheng

    2018-06-01

    It is essential to synthesize low-cost, earth-abundant bifunctional electrocatalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reactions (OER) for water electrolysis. Herein, we present a one-step sulfurization method to fabricate Ni3S2 nanowires directly grown on Ni foam (Ni3S2 NWs/Ni) as such an electrocatalyst. This synthetic strategy has several advantages including facile preparation, low cost and can even be expanded to large-scale preparation for practical applications. The as-synthesized Ni3S2 NWs/Ni exhibits a low overpotential of 81 and 317 mV to render a current density of 10 mA cm‑2 for the HER and OER, respectively, in 1.0 mol l‑1 KOH solution. The Ni3S2 NWs/Ni was integrated to be the cathode and the anode in the alkaline electrolyzer for overall water splitting with a current density of 10 mA cm‑2 afforded at a cell voltage of 1.63 V. More importantly, this electrolyzer maintained its electrocatalytic activity even after continual water splitting for 30 h. Owing to its simple synthesis process, the earth-abundant electrocatalyst and high performance, this versatile Ni3S2 NWs/Ni electrode will become a promising electrocatalyst for water splitting.

  20. Lung clearance and disposition of 63Ni in F344/N rats after intratracheal instillation of nickel sulfate solutions

    International Nuclear Information System (INIS)

    Medinsky, M.A.; Benson, J.M.; Hobbs, C.H.

    1987-01-01

    Epidemiology studies have indicated increased incidences of respiratory tract and renal cancer in nickel refinery workers. Since the most likely route of exposure to nickel in the workplace is via the respiratory tract, the objectives of the experiments described here were to determine the retention pattern of Ni in the lungs, identify the target organs for Ni absorbed from the respiratory tract, and determine rates for excretion of Ni. Male and female F344 rats were given 17, 190, or 1800 nmoles Ni (as a nickel sulfate solution) in saline, containing trace amounts of 63 Ni, by intratracheal instillation. Urine and feces were collected, and rats were necropsied at predetermined times up to 96 hr after instillation. At all times, lungs, trachea, larynx, kidney, and urinary bladder contained the highest concentrations of Ni as determined by liquid scintillation spectrometry. Urine was the major route for excretion of Ni, accounting for 50% of the dose after instillation of 17 or 190 nmoles Ni, and 80% of the dose after instillation of 1800 nmoles Ni. The half-time for urinary excretion of Ni increased from 4.6 hr at the highest dose to 23 hr at the lowest dose used. Fecal excretion accounted for 30% (17- and 190-nmole doses) or 13% (1800 nmoles) of the initial dose. Of the Ni remaining in the body at the end of 96 hr, over 50% was in the lungs. The long-term half-time for clearance of Ni from the lungs ranged from 21 hr at the highest dose to 36 hr at the lowest dose instilled. As the amount of instilled Ni decreased, the fraction of the instilled Ni associated with the long-term clearance component increased (from 24% at the highest dose to 40% at the lowest dose). Results suggest that, over the range of doses studied, both pulmonary clearance of Ni and routes for excretion of Ni were dependent on the instilled dose

  1. A comprehensive study on photocatalytic activity of supported Ni/Pb sulfide and oxide systems onto natural zeolite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Babaahamdi-Milani, Majid [Department of Chemistry, Shahreza Branch, Islamic Azad University, P.O. Box 311-86145, Shahreza, Isfahan (Iran, Islamic Republic of); Young Researchers and Elite Club, Shahreza Branch, Islamic Azad University, Shahreza (Iran, Islamic Republic of); Nezamzadeh-Ejhieh, Alireza, E-mail: arnezamzadeh@iaush.ac.ir [Department of Chemistry, Shahreza Branch, Islamic Azad University, P.O. Box 311-86145, Shahreza, Isfahan (Iran, Islamic Republic of); Young Researchers and Elite Club, Shahreza Branch, Islamic Azad University, Shahreza (Iran, Islamic Republic of); Razi Chemistry Research Center (RCRC), Shahreza Branch, Islamic Azad University, Isfahan (Iran, Islamic Republic of)

    2016-11-15

    Highlights: • Increase in photocatalytic activity of hybridized/supported PbO/NiO and PbS/NiS systems with respect to semiconductors alone. • Higher efficiency of PbO/NiO than PbS/NiS. • Positive role of p-n junction for enhancement of photocatalytic activity of the used semiconductors. - Abstract: The Ni(II)-Pb(II) exchanged clinoptilolite nanoparticles (NCP) were transformed to corresponding oxides and sulfides via calcination and sulfiding processes, respectively. The obtained catalysts were characterized by XRD, FT-IR, TEM and DRS and used in photodegradation of p-nitrophenol (4-NP) aqueous solution under Hg-lamp irradiation. Results showed considerable increase in activity of the coupled semiconductors with respect to monocomponent one. In NiO-PbO-NCP system, conduction band (CB) of NiO is enough negative for easily migration of photogenerated electrons to CB-PbO level, while such phenomena take place from more negative CB-PbS level to CB-NiS level in NiS-PbS-NCP. These phenomena significantly prevented from electron-hole recombination which increased photocatalytic activity of the coupled semiconductors. Best photodegradation activities obtained by NiO{sub 1.3%}–PbO{sub 14.7%}-NCP and NiS{sub 2.1%}–PbS{sub 10.0%}-NCP, confirming semiconductors' mass-ratio dependence of the photocatalytic process. The supported coupled semiconductors showed blue shifts in band gap energies with respect to the bulk semiconductors which confirm formation of semiconductors nanoparticles inside the zeolite framework. The highest degradation percentage of 4-NP was obtained at: 0.5 g L{sup −1} photocatalysts, 15 mg L{sup −1} 4-NP at pH 7.5.

  2. ROS generation and MAPKs activation contribute to the Ni-induced testosterone synthesis disturbance in rat Leydig cells.

    Science.gov (United States)

    Han, Aijie; Zou, Lingyue; Gan, Xiaoqin; Li, Yu; Liu, Fangfang; Chang, Xuhong; Zhang, Xiaotian; Tian, Minmin; Li, Sheng; Su, Li; Sun, Yingbiao

    2018-06-15

    Nickel (Ni) can disorder testosterone synthesis in rat Leydig cells, whereas the mechanisms remain unclear. The aim of this study was to investigate the role of reactive oxygen species (ROS) and mitogen-activated protein kinases (MAPKs) in Ni-induced disturbance of testosterone synthesis in rat Leydig cells. The testosterone production and ROS levels were detected in Leydig cells. The mRNA and protein levels of testosterone synthetase, including StAR, CYP11A1, 3β-HSD, CYP17A1 and 17β-HSD, were determined. Effects of Ni on the ERK1/2, p38 and JNK MAPKs were also investigated. The results showed that Ni triggered ROS generation, consequently resulted in the decrease of testosterone synthetase expression and testosterone production in Leydig cells, which were then attenuated by ROS scavengers of N-acetylcysteine (NAC) and 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), indicating that ROS are involved in the Ni-induced testosterone biosynthesis disturbance. Meanwhile Ni activated the ERK1/2, p38 and JNK MAPKs. Furthermore, Ni-inhibited testosterone synthetase expression levels and testosterone secretion were all alleviated by co-treatment with MAPK specific inhibitors (U0126 and SB203580, respectively), implying that Ni inhibited testosterone synthesis through activating ERK1/2 and p38 MAPK signal pathways in Leydig cells. In conclusion, these findings suggest that Ni causes testosterone synthesis disorder, partly, via ROS and MAPK signal pathways. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Effect of Ni Core Structure on the Electrocatalytic Activity of Pt-Ni/C in Methanol Oxidation

    Directory of Open Access Journals (Sweden)

    Vladimir Linkov

    2013-07-01

    Full Text Available Methanol oxidation catalysts comprising an outer Pt-shell with an inner Ni-core supported on carbon, (Pt-Ni/C, were prepared with either crystalline or amorphous Ni core structures. Structural comparisons of the two forms of catalyst were made using transmission electron microscopy (TEM, X-ray diffraction (XRD and X-ray photoelectron spectroscopy (XPS, and methanol oxidation activity compared using CV and chronoamperometry (CA. While both the amorphous Ni core and crystalline Ni core structures were covered by similar Pt shell thickness and structure, the Pt-Ni(amorphous/C catalyst had higher methanol oxidation activity. The amorphous Ni core thus offers improved Pt usage efficiency in direct methanol fuel cells.

  4. Widely available active sites on Ni2P for electrochemical hydrogen evolution - insights from first principles calculations

    DEFF Research Database (Denmark)

    Hansen, Martin Hangaard; Stern, Lucas-Alexandre; Feng, Ligang

    2015-01-01

    We present insights into the mechanism and the active site for hydrogen evolution on nickel phosphide (Ni2P). Ni2P was recently discovered to be a very active non-precious hydrogen evolution catalyst. Current literature attributes the activity of Ni2P to a particular site on the (0001) facet....... In the present study, using Density Functional Theory (DFT) calculations, we show that several widely available low index crystal facets on Ni2P have better properties for a high catalytic activity. DFT calculations were used to identify moderately bonding nickel bridge sites and nickel hollow sites for hydrogen...... adsorption and to calculate barriers for the Tafel pathway. The investigated surfaces in this study were the (10 (1) over bar0), ((1) over bar(1) over bar 20), (11 (2) over bar0), (11 (2) over bar1) and (0001) facets of the hexagonal Ni2P crystal. In addition to the DFT results, we present experiments on Ni2...

  5. Effects of preparation method and active metal content on of Ni/kieselguhr catalyst activity

    International Nuclear Information System (INIS)

    Galuh Widiyarti; Wuryaningsih Sri Rahayu

    2010-01-01

    The preparation and the active metal content influence the activity of catalyst. Study has been conducted to see the activity of Ni/kieselguhr based on preparation method and Nickel (Ni) contents in the catalyst in the laboratory scale. The Ni/kieselguhr catalyst were prepared by impregnation and precipitation methods, with Ni active contents of 10, 20, and 30 % by weight. The catalysts characterization was analyzed using X-Ray Diffraction (XRD). Catalysts activities were analyzed based on decreasing of iodine number from hydrogenation of crude palm oil for 2 hours. The activity tests results show that precipitation catalysts are more active than impregnation catalysts. The decreasing in iodine number of fatty acid after 2 hours of hydrogenation process using precipitation catalysts and impregnation catalysts are 51.53 and 21.85 %, respectively. In addition, the catalysts are more active with increasing Ni contents. (author)

  6. Enhancing the water oxidation activity of Ni2P nanocatalysts by iron-doping and electrochemical activation

    International Nuclear Information System (INIS)

    Liu, Guang; He, Dongying; Yao, Rui; Zhao, Yong; Li, Jinping

    2017-01-01

    Highlights: •A sol-gel method for synthesis of Fe-doping Ni 2 P nanocatalysts was present. •Fe-doping Ni 2 P sample exhibited high OER activity after electrochemical activation. •In situ formed Fe-NiOOH layer on activated Fe-Ni 2 P provided more active OER sites. -- Abstract: In this work, we reported a facile and safe route for synthesis of Ni 2 P nanocatalysts by sol-gel method and demonstrated that the oxygen evolution reaction (OER) activity of Ni 2 P nanocatalysts can be dramatically enhanced by iron-doping and electrochemical activation. Compared with the fresh Fe-doped Ni 2 P nanocatalysts, a stable Fe-NiOOH layer was formed on the surface of Fe-doped Ni 2 P nanoparticles by electrochemical activation, thus promoting the charge transfer ability and surface electrochemically active sites generation for the electrochemical activated Fe-doped Ni 2 P nanocatalysts, ultimately accounting for the improvement of water oxidation activity, which was evidenced by cyclic voltammograms (CV), electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectra (XPS) as well as high-resolution transmission electron microscopy (HR-TEM) measurements. For water oxidation reaction in 1 M KOH solution, the electrochemical activated Fe-doped Ni 2 P nanocatalysts can attain 10 mA/cm 2 at an overpotential of 292 mV with Tafel slope of 50 mV/dec, which was also much better than that of individual Ni 2 P, Fe 2 P nanocatalysts as well as commercial RuO 2 electrocatalyst. Moreover, long-term stability performance by chronoamperometric and chronopotentiometric tests for the activated Fe-doped Ni 2 P nanocatalysts exhibited no obvious decline within 56 h. It was demonstrated that modulating the OER catalytic activity for metal phosphide by iron-doping and electrochemical activation may provide new opportunities and avenues to engineer high performance electrocatalysts for water splitting.

  7. Spatio-temporal variability of lightning and convective activity over South/South-East Asia with an emphasis during El Niño and La Niña

    Science.gov (United States)

    Saha, Upal; Siingh, Devendraa; Midya, S. K.; Singh, R. P.; Singh, A. K.; Kumar, S.

    2017-11-01

    The present analysis investigates the spatio-temporal variability of the convective parameters and associated lightning flash rates during the period 1997-2013 including the El Niño and La Niña episode. It reveals that north-western and north-eastern part along the foothills of Himalayas as well as Indo-China peninsular region and South China Sea are much convective prone zones over the South/South-East Asia. The terrain/orography of the Himalayan range, the influence of cross-equatorial low-level jet and large-scale circulation during pre-monsoon and active phase of monsoon, the western Pacific Warm Pool with increased sea surface temperature as well as the solar-heating-originated local instability instigate the convective anomaly to propagate over the north-western and north eastern Indian sub-continent along with the Indo-China peninsula and South China Sea respectively. The land surfaces of the Indian sub-continent and the sea surface of South China Sea possesses significant correlation with lightning flash rates and convective parameters whereas the sea surface surrounding Indian sub-continent do not show such good correlations among them. Although, the occurrence of convective activities during the El Niño (La Niña) gets reduced (increased), the occurrence of lightning flashes gets enhanced (diminished) during this period which may be the direct consequence of warming atmosphere in relation to changing patterns of regional climate. Fig. S2 Spatial trend distribution per year of (a) LFR, (b) CAPE, (c) SCP, (d) LI, (e) CINE and (f) AT anomaly over South/South-East Asia during January-December for the years 1997-2013 (Trend is significant at 95% confidence level). Fig. S3 Correlation maps of LFR with (a) CAPE, (b) SCP, (c) CINE and (d) LI over South/South-East Asia during January-December for the years 1997-2013. Fig. S4 Synoptic wind direction patterns during (a)-(b) El Niño (May 2002 - February 2003) conditions and (c)-(d) La Niña (July 1998 - March

  8. Determination of selenium in Ni + Co concentrates applying epithermal neutron activation analysis

    International Nuclear Information System (INIS)

    Capote Rodriguez, G.; Perez Sayaz, G.; Hernandez Rivero, A.; Moreno Bermudez, J.; Ribeiro Guevara, S.; Arribere, M.A.; Molina Insfran, J.

    1996-01-01

    Concentration of Se in Ni + Co concentrates obtained in nickel industry has to be determined as that is a quality control requirement for its commercialization. At present, analysis of Se, specially at a minor and trace levels is relatively complicated and destructive procedures are frequently required. In this work determination of Se by epithermal neutron activation analysis (ENAA) in 17 samples of nickel industry was investigated. Application of ENAA allowed nondestructive determination of Se concentration down to ppm level in spite of presence of high Co, Fe, Ni, and Cr contents in the samples

  9. Analysis of neonicotinoids by gas chromatography coupled to nuclide {sup 63}Ni - Electron Capture Detector - GC/ECD

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, Priscila O.; Leao, Claudio; Redigolo, Marcelo M.; Crepaldi, Caike; Bustillos, Oscar V., E-mail: priscilaoamaral@gmail.com, E-mail: claudio.leao@usp.br, E-mail: marceloredigolo@gmail.com, E-mail: caike1995@gmail.com, E-mail: ovega@ipen.bremails [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Recently, several reports have been published discussing reduction in bee population which polymerizes cultures around the world this phenomenon is known as Colony Collapse Disorder (CCD). The phenomenon describes the lack of worker honeybees in the colony despite having pups and food. The causes of this problem are unknown but there are studies that claim that reduction of population of bees is linked to poisoning through insecticides specifically neonicotinoids. Among this type of pesticide are imidacloprid (C{sub 9}H{sub 10}ClN{sub 5}O{sub 2}), clothianidin (C{sub 6}H{sub 8}ClN{sub 5}O{sub 2}S) and thiamethoxam (C{sub 8}H{sub 10}ClN{sub 5}O{sub 3}S). This paper presents the analysis of neonicotinoids - clothianidin, imidacloprid and thiamethoxam - by the technique of gas chromatography coupled to nuclide {sup 63}Ni electron capture detector (GC/ECD). The electron capture detector (ECD) is a gas chromatography detector that has been used for the detection of organic halogens, nitriles, nitrates and organometallic compounds. The ECD detector ionizes the analytes by the beta particles from the nuclide sources {sup 63}Ni within carrier gas N{sub 2}. The electrons produced in this process are collected and create a current that are amplified and generates a chromatographic peak. Methodology and details of the analysis are present in this work. (author)

  10. Synthesis of a novel Au nanoparticles decorated Ni-MOF/Ni/NiO nanocomposite and electrocatalytic performance for the detection of glucose in human serum.

    Science.gov (United States)

    Chen, Jingyuan; Xu, Qin; Shu, Yun; Hu, Xiaoya

    2018-07-01

    A nonenzymatic glucose electrochemical sensor was constructed based on Au nanoparticles (AuNPs) decorated Ni metal-organic-framework (MOF)/Ni/NiO nanocomposite. Ni-MOF/Ni/NiO nanocomposite was synthesized by one-step calcination of Ni-MOF. Then AuNPs were loaded onto the Ni-based nanocomposites' surface through electrostatic adsorption. Through characterization by transmission electron microscopy (TEM), high resolution TEM (HRTEM) and energy disperse spectroscopy (EDS) mapping, it is found that the AuNPs were well distributed on the surface of Ni-based nanocomposite. Cyclic voltammetric (CV) study showed the electrocatalytic activity of Au-Ni nanocomposite was highly improved after loading AuNPs onto it. Amperometric study demonstrated that the Au-Ni nanocomposites modified glassy carbon electrode (GCE) exhibited a high sensitivity of 2133.5 mA M -1 cm -2 and a wide linear range (0.4-900 μM) toward the oxidation of glucose with a detection limit as low as 0.1 μM. Moreover, the reproducibility, selectivity and stability of the sensor all exhibited outstanding performance. We applied the as-fabricated high performance sensor to measure the glucose levels in human serum and obtained satisfactory results. It is believed that AuNPs decorated Ni MOF/Ni/NiO nanocomposite provides a new platform for developing highly performance electrochemical sensors in practical applications. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Amorphous NiFe-OH/NiFeP Electrocatalyst Fabricated at Low Temperature for Water Oxidation Applications

    KAUST Repository

    Liang, Hanfeng

    2017-04-11

    Water splitting driven by electricity or sunlight is one of the most promising ways to address the global terawatt energy needs of future societies; however, its large-scale application is limited by the sluggish kinetics of the oxygen evolution reaction (OER). NiFe-based compounds, mainly oxides and hydroxides, are well-known OER catalysts and have been intensively studied; however, the utilization of the synergistic effect between two different NiFe-based materials to further boost the OER performance has not been achieved to date. Here, we report the rapid conversion of NiFe double hydroxide into metallic NiFeP using PH3 plasma treatment and further construction of amorphous NiFe hydroxide/NiFeP/Ni foam as efficient and stable oxygen-evolving anodes. The strong electronic interactions between NiFe hydroxide and NiFeP significantly lower the adsorption energy of H2O on the hybrid and thus lead to enhanced OER performance. As a result, the hybrid catalyst can deliver a geometrical current density of 300 mA cm–2 at an extremely low overpotential (258 mV, after ohmic-drop correction), along with a small Tafel slope of 39 mV decade–1 and outstanding long-term durability in alkaline media.

  12. Disclosure of key stereoelectronic factors for efficient H2 binding and cleavage in the active site of [NiFe]-hydrogenases.

    Science.gov (United States)

    Bruschi, Maurizio; Tiberti, Matteo; Guerra, Alessandro; De Gioia, Luca

    2014-02-05

    A comparative analysis of a series of DFT models of [NiFe]-hydrogenases, ranging from minimal NiFe clusters to very large systems including both the first and second coordination sphere of the bimetallic cofactor, was carried out with the aim of unraveling which stereoelectronic properties of the active site of [NiFe]-hydrogenases are crucial for efficient H2 binding and cleavage. H2 binding to the Ni-SIa redox state is energetically favored (by 4.0 kcal mol(-1)) only when H2 binds to Ni, the NiFe metal cluster is in a low spin state, and the Ni cysteine ligands have a peculiar seesaw coordination geometry, which in the enzyme is stabilized by the protein environment. The influence of the Ni coordination geometry on the H2 binding affinity was then quantitatively evaluated and rationalized analyzing frontier molecular orbitals and populations. Several plausible reaction pathways leading to H2 cleavage were also studied. It turned out that a two-step pathway, where H2 cleavage takes place on the Ni-SIa redox state of the enzyme, is characterized by very low reaction barriers and favorable reaction energies. More importantly, the seesaw coordination geometry of Ni was found to be a key feature for facile H2 cleavage. The discovery of the crucial influence of the Ni coordination geometry on H2 binding and activation in the active site of [NiFe]-hydrogenases could be exploited in the design of novel biomimetic synthetic catalysts.

  13. Differences in genotoxic activity of alpha-Ni3S2 on human lymphocytes from nickel-hypersensitized and nickel-unsensitized donors.

    Science.gov (United States)

    Arrouijal, F Z; Marzin, D; Hildebrand, H F; Pestel, J; Haguenoer, J M

    1992-05-01

    The genotoxic activity of alpha-Ni3S2 was assessed on human lymphocytes from nickel-hypersensitized (SSL) and nickel-unsensitized (USL) subjects. Three genotoxicity tests were performed: the sister chromatid exchange (SCE) test, the metaphase analysis test and the micronucleus test. (i) The SCE test (3-100 micrograms/ml) showed a weak but statistically significant increase in the number of SCE in both lymphocyte types with respect to controls, USL presenting a slightly higher SCE incidence but only at one concentration. (ii) The metaphase analysis test demonstrated a high dose-dependent clastogenic activity of alpha-Ni3S2 in both lymphocyte types. The frequency of chromosomal anomalies was significantly higher in USL than in SSL for all concentrations applied. (iii) The micronucleus test confirmed the dose-dependent clastogenic activity of alpha-Ni3S2 and the differences already observed between USL and SSL, i.e. the number of cells with micronuclei was statistically higher in USL. Finally, the incorporation study with alpha-63Ni3S2 showed a higher uptake of its solubilized fraction by USL. This allows an explanation of the different genotoxic action of nickel on the two cell types. In this study we demonstrated that hypersensitivity has an influence on the incorporation of alpha-Ni3S2 and subsequently on the different induction of chromosomal aberrations in human lymphocytes.

  14. A NEUTRON DIFFRACTION DETERMINATION OF SHORT RANGE ORDER IN A Ni63.7Zr36.3 GLASS

    OpenAIRE

    Bellissent , R.; Bigot , J.; Calvayrac , Y.; Lefebvre , S.; Quivy , A.

    1985-01-01

    A precise determination of the three partial structure factors for the eutectic composition Ni63.7Zr36.3 has been carried out using neutron diffraction on three isotopically substituted glasses. The use of a "zero alloy" yields a direct determination of the Bhatia-Thornton structure factor SCC. Evidence for the existence of strong chemical short-range order and a clear size effect is obtained. Due to this chemical order, the partial structure factors cannot be consistent with the ones calcula...

  15. Preparation and characterization of a supported system of Ni2P/Ni12P5 nanoparticles and their use as the active phase in chemoselective hydrogenation of acetophenone

    Science.gov (United States)

    Costa, Dolly C.; Soldati, Analía L.; Pecchi, Gina; Bengoa, José Fernando; Marchetti, Sergio Gustavo; Vetere, Virginia

    2018-05-01

    Ni2P/Ni12P5 nanoparticles were obtained by thermal decomposition of nickel organometallic salt at low temperature. The use of different characterization techniques allowed us to determine that this process produced a mixture of two nickel phosphide phases: Ni2P and Ni12P5. These nickel phosphides nanoparticles, supported on mesoporous silica, showed activity and high selectivity for producing the hydrogenation of the acetophenone carbonyl group to obtain 1-phenylethanol. This is a first report that demonstrates the ability of supported Ni2P/Ni12P5 nanoparticles to produce the chemoselective hydrogenation of acetophenone. We attribute these special catalytic properties to the particular geometry of the Ni–P sites on the surface of the nanoparticles. This is an interesting result because the nickel phosphides have a wide composition range (from Ni3P to NiP3), with different crystallographic structures, therefore we think that different phases could be active and selective to hydrogenate many important molecules with more than one functional group.

  16. Low-level radioactive waste, mixed low-level radioactive waste, and biomedical mixed waste

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    This document describes the proceedings of a workshop entitled: Low-Level Radioactive Waste, Mixed Low-Level Radioactive Waste, and Biomedical Mixed Waste presented by the National Low-Level Waste Management Program at the University of Florida, October 17-19, 1994. The topics covered during the workshop include technical data and practical information regarding the generation, handling, storage and disposal of low-level radioactive and mixed wastes. A description of low-level radioactive waste activities in the United States and the regional compacts is presented

  17. Determination of nickel-63

    International Nuclear Information System (INIS)

    Poletiko, C.

    1988-01-01

    The research of activation products in the environment is often centered on cobalt-60 or other gamma emitters, since pure beta emitters require time consuming separations to be counted. However, some beta emitters must be checked because they have a build up in the environment, leading to potential hazards. Among these nuclides, there is nickel-63 which is a pure, soft beta emitter (67 keV) with a long half-life (100 years). A chemical separation, providing good results, was developed. Such a separation is based upon nickel carrier addition in the sample than DMG complex formation and isolation; after elimination of solvent. DMG complex is destroyed. Chemical yield is determined by flame atomic absorption measurement and nickel-63 counted by liquid scintillation. The described procedure allows the determination of low-level activities in different samples (soils, effluents, etc.). Detection limits are close to 0.1 Bq per sample

  18. Trace element assessment of low-alloy and stainless steels with reference to gamma activity

    International Nuclear Information System (INIS)

    Goddard, A.J.H.; Macmahon, T.D.; Gamberini, D.; Taylor, J.M.; Duggan, F.

    1984-01-01

    In order to predict the long-lived gamma activities leading to radiation exposure during dismantling operations it is necessary to know the likely trace element content of the reactor vessel and internals. This work has been concerned with measuring the elements Ni, Nb, Mo, Co, Ag, Eu, Sm and Ho in steels, with particular reference to light-water reactors. Various steel samples have been provided by organizations in Europe. Analyses have been carried out principally by neutron activation analysis, but also by atomic absorption (AA), inductively coupled plasma (ICP) and secondary ion microprobe spectrometry (SIMS). Analyses for Ni, Mo and Co were straightforward and results agreed with analyses carried out elsewhere. A variety of techniques were employed for Nb; ICP was the most successful and results were confirmed using SIMS. In the case of Ag only flameless AA yielded results for all samples. The low concentration of rare earth elements required the development of a preliminary ion exchange technique. Low-alloy steels examined had Nb concentrations less than 10 ppm. Ag levels in the vicinity of 1 ppm were found in all steel samples, indicating that Ag may be the most significant element at long cooling times. Rare earth concentrations from this and other work indicate that these elements are unlikely to give gamma activities exceeding those of 60 Co, 59 Ni, sup(108m)Ag and 94 Nb activities. Illustrative gamma activity decay calculations using the Origen code are presented

  19. Low-level dosimetry based on activation analysis of badge film, 1

    International Nuclear Information System (INIS)

    Morikawa, Kaoru; Yamashita, Kazuya; Inamoto, Kazuo; Maeda, Masayuki; Sato, Takashi; Ono, Koichi.

    1988-01-01

    Underexposed badge film contains a minor quantity of silver which corresponds to the low radiation dose even after completion of the photographic densitometry ; however, it cannot be detected with a photographic densitometer. We intended to clarify the minor silver content based on radioactivation analysis with thermal neutrons at KUR (Kyoto University Research Reactor). The natural silver consists of two stable nuclides, i.e., 107 Ag and 109 Ag. These can be activated with irradiation of thermal neutrons to two radionuclides, i.e., 108 Ag and 110 Ag. In this paper, through the activation analysis of an underexposed badge film, methods of measurements are shown regarding both 108 Ag produced by the 107 Ag (n, γ) reaction and 110 Ag by the 109 Ag (n, γ). After underexposed badge films were irradiated with thermal neutrons, some gamma-rays emitted from the radionuclides in the activated films were measured with a high pure Ge detector or a NaI (Tl) scintillation detector. The following results were obtained: (1) several elements such as silver, iodine, gold, antimony, manganese and copper were detected by activation analyses of films exposed to low level 60 Co gamma-rays, (2) the exposure vs 108 Ag or 110 Ag activity curve was linear in the lower dose range of 60 Co gamma-rays. These data indicate that low level radiation doses, which is indeterminable by ordinary photographic densitometry, can be estimated by activation analysis of silver atoms in badge films. (author)

  20. 59Ni and 63Ni separation from boric acid concentrates produced at NPP

    International Nuclear Information System (INIS)

    Fisera, O.

    2010-01-01

    Procedure for direct separation of radionickel from boric acid concentrate was developed. Quantitative separation from 100 mL of real concentrate on the column filled with 3 mL of PAN-DMG composite material was achieved. PAN-DMG material (dimethylglyoxime in porous beads of polyacrylonitrile) was compared with Ni Resin and DMG-PAN material exhibited higher sorption capacity for nickel than Ni Resin. (author)

  1. Status of activities: Low-level radioactive waste management in the United States

    International Nuclear Information System (INIS)

    Ozaki, C.B.; Shilkett, R.C.; Kirkpatrick, T.D.

    1989-01-01

    A primary objective of low-level radioactive waste management in the United States is to protect the health and safety of the public and the quality of the environment. In support of this objective is the development of waste treatment and disposal technologies designed to provide stabilization and long-term institutional control of low-level radioactive wastes. Presented herein is a technical review of specific low-level radioactive waste management activities in the United States. Waste treatment and disposal technologies are discussed along with the performance objectives of the technologies aimed at protecting the health and safety of the public and the quality of the environment. 13 refs., 4 figs

  2. Segregation of low-level dry active waste

    International Nuclear Information System (INIS)

    Kornblith, L. Jr.; Naughton, M.D.; Welsh, L.

    1984-01-01

    A program has been carried out to characterize the Dry Active Waste (DAW) stream from a typical PWR power plant in order to determine the usefulness of large-volume DAW monitors for segregating such waste in order to dispose of it in appropriate facilities. A waste monitor using plastic scintillation counters was used for measuring the waste. The monitor had a volume of about 300 liters and an overall efficiency of about 12% for a typical fission product mixture. It provides automatic compensation for background radioactivity and can measure a bag of waste in less than a minute, including background measurements. Six hundred consecutively generated bags of DAW were measured. These had a total activity of about one millicurie and an average specific activity of about 540 nanocuries per kilogram. About half of the bags contained less than 1000 nanocuries and had specific activities of less than 100 nanocuries per kilogram. Based on simplified preliminary calculations, it appears that an evaluation of the risks of disposal of bags such as these in a landfill other than a low-level waste disposal facility could be carried out that would demonstrate that such disposal of half or more of these bags would not result in any substantial hazard, either short or long term

  3. Simulation of Ni-MH Batteries via an Equivalent Circuit Model for Energy Storage Applications

    Directory of Open Access Journals (Sweden)

    Ying Zhu

    2016-01-01

    Full Text Available Impedance measurement was conducted at the entire cell level for studying of the Ni-MH rechargeable batteries. An improved equivalent circuit model considering diffusion process is proposed for simulation of battery impedance data at different charge input levels. The cell capacity decay was diagnosed by analyzing the ohmic resistance, activation resistance, and mass transfer resistance of the Ni-MH cells with degraded capacity. The capacity deterioration of this type, Ni-MH cell, is considered in relation to the change of activation resistance of the nickel positive electrodes. Based on the report and surface analysis obtained from the energy dispersive X-ray spectroscopy, the composition formula of metal-hydride electrodes can be closely documented as the AB5 type alloy and the “A” elements are recognized as lanthanum (La and cerium (Ce. The capacity decay of the Ni-MH cell is potentially initiated due to starved electrolyte for the electrochemical reaction of active materials inside the Ni-MH battery, and the discharge product of Ni(OH2 at low state-of-charge level is anticipated to have more impeding effects on electrode kinetic process for higher power output and efficient energy delivery.

  4. Study of a betavoltaic battery using electroplated nickel-63 on nickel foil as a power source

    International Nuclear Information System (INIS)

    Uhm, Young Rang; Kim, Jong Bum; Son, Kwang Jae; Choi, Byoung Gun; Jeong, Dong Hyuk

    2016-01-01

    A betavoltaic battery was prepared using radioactive 63 Ni attached to a three-dimensional single trenched P-N absorber. The optimum thickness of a 63Ni layer was determined to be approximately 2 μm, considering the minimum self-shielding effect of beta particles. Electroplating of radioactive 63 Ni on a nickel (Ni) foil was carried out at a current density of 20 mA/cm 2 . The difference of the short-circuit currents (I sc ) between the pre- and postdeposition of 63 Ni (16.65 MBq) on the P#-N junction was 5.03 nA, as obtained from the I-V characteristics. An improved design with a sandwich structure was provided for enhancing performance

  5. First-principles study of low Miller index Ni3S2 surfaces in hydrotreating conditions.

    Science.gov (United States)

    Aray, Yosslen; Vega, David; Rodriguez, Jesus; Vidal, Alba B; Grillo, Maria Elena; Coll, Santiago

    2009-03-12

    Density functional theory (DFT) calculations combined with surface thermodynamic arguments and the Gibbs-Curie-Wulff equilibrium morphology formalism have been employed to explore the effect of the reaction conditions, temperature (T), and gas-phase partial pressures (PH2 and PH2S) on the stability of nickel sulfide (Ni3S2) surfaces. Furthermore, the strength and nature of chemical bonds for selected Ni3S2 surface cuts were investigated with the quantum theory of atoms in molecules methodology. A particular analysis of the electrostatic potential within this theoretical framework is performed to study the potential activity of nickel sulfide nanoparticles as hydrodesulfurization (HDS) catalysts. The calculated thermodynamic surface stabilities and the resulting equilibrium morphology model suggest that unsupported Ni3S2 nanoparticles mainly expose (111) and (111) type surface faces in HDS conditions. Analysis of the electrostatic potential mapped onto a selected electron density isocontour (0.001 au) on those expose surface reveals a poor potential reactivity toward electron-donating reagents (i.e., low Lewis acidity). Consequently, a very low attraction between coordinatively unsaturated active sites (Lewis sites) exposed at the catalytic particles and the S atoms coming from reagent polluting molecules does inactive these kinds of particles for HDS.

  6. Pt-Ni and Pt-M-Ni (M = Ru, Sn Anode Catalysts for Low-Temperature Acidic Direct Alcohol Fuel Cells: A Review

    Directory of Open Access Journals (Sweden)

    Ermete Antolini

    2017-01-01

    Full Text Available In view of a possible use as anode materials in acidic direct alcohol fuel cells, the electro-catalytic activity of Pt-Ni and Pt-M-Ni (M = Ru, Sn catalysts for methanol and ethanol oxidation has been widely investigated. An overview of literature data regarding the effect of the addition of Ni to Pt and Pt-M on the methanol and ethanol oxidation activity in acid environment of the resulting binary and ternary Ni-containing Pt-based catalysts is presented, highlighting the effect of alloyed and non-alloyed nickel on the catalytic activity of these materials.

  7. Reference values on safety regulation of land disposal of low level radioactive solid waste (the second interim report) and its incorporation into legal regulations

    International Nuclear Information System (INIS)

    Aoki, Terumi

    1994-01-01

    Safety regulation of land disposal of low level radioactive solid waste in Japan is based on 'the basic philosophy on the safety regulation of land disposal of low level radioactive solid waste' determined by the Nuclear safety Committee (October 1985). The basic philosophy on the upper limit of radioactivity of disposed wastes was published as the reference values in the interim report (February 1987) and in the second interim report (June 1992). In the second interim report, the upper limits of radioactivity are established for three types of solid radioactive wastes: 1) metals, incombustible or flame resistant wastes generated nuclear reactor facilities and solidified in vessels, 2) large metallic structures generated from decommissioning of reactor facilities and difficult to solidify in vessels, and 3) radioactive concrete waste generated from decommissioning of reactor facilities. The upper limits of radioactivity are presented for C-14, Co-60, Ni-63, Sr-90, Cs-137, alfa-emmitters, Ca-41 (for concrete) and Eu-152 (for concrete). Related laws and regulations in Japan on safe disposal of low level wastes are explained. (T.H.)

  8. Low level alpha activity measurements with pulse shape discrimination

    International Nuclear Information System (INIS)

    Noguchi, Masayasu; Satoh, Kaneaki; Higuchi, Hideo.

    1984-01-01

    Pulse shape discrimination of α and β rays with liquid scintillation counting was investigated for the purpose of low level α activity measurements. Various liquid scintillators for pulse shape discrimination were examined by means of pulse rise time analysis. A new scintillator of low cost and of superior characteristics was found. The figure of merits better than 3.5 in risetime spectrum and the energy resolution better than 9% were obtained for carefully prepared samples. The background counting rate for a sample of 10 ml was reduced to 0.013 cpm/MeV in the range of α ray energy 5 to 7 MeV. (author)

  9. Structure determination of the ordered (2 × 1) phase of NiSi surface alloy on Ni(111) using low-energy electron diffraction

    Science.gov (United States)

    Sazzadur Rahman, Md.; Amirul Islam, Md.; Saha, Bidyut Baran; Nakagawa, Takeshi; Mizuno, Seigi

    2015-12-01

    The (2 × 1) structure of the two-dimensional nickel silicide surface alloy on Ni(111) was investigated using quantitative low-energy electron diffraction analysis. The unit cell of the determined silicide structure contains one Si and one Ni atom, corresponding to a chemical formula of NiSi. The Si atoms adopt substitutional face-centered cubic hollow sites on the Ni(111) substrate. The Ni-Si bond lengths were determined to be 2.37 and 2.34 Å. Both the alloy surface and the underlying first layers of Ni atoms exhibit slight corrugation. The Ni-Si interlayer distance is smaller than the Ni-Ni interlayer distance, which indicates that Si atoms and underlying Ni atoms strongly interact.

  10. Study of a betavoltaic battery using electroplated nickel-63 on nickel foil as a power source

    Energy Technology Data Exchange (ETDEWEB)

    Uhm, Young Rang; Kim, Jong Bum; Son, Kwang Jae [Radioisotope Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Choi, Byoung Gun [Human Interface SoC Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon (Korea, Republic of); Jeong, Dong Hyuk [Dongnam Institute of Radiological and Medical Science, Busan(Korea, Republic of)

    2016-06-15

    A betavoltaic battery was prepared using radioactive {sup 63}Ni attached to a three-dimensional single trenched P-N absorber. The optimum thickness of a 63Ni layer was determined to be approximately 2 μm, considering the minimum self-shielding effect of beta particles. Electroplating of radioactive {sup 63}Ni on a nickel (Ni) foil was carried out at a current density of 20 mA/cm{sup 2}. The difference of the short-circuit currents (I{sub sc}) between the pre- and postdeposition of {sup 63}Ni (16.65 MBq) on the P#-N junction was 5.03 nA, as obtained from the I-V characteristics. An improved design with a sandwich structure was provided for enhancing performance.

  11. Study of a Betavoltaic Battery Using Electroplated Nickel-63 on Nickel Foil as a Power Source

    Directory of Open Access Journals (Sweden)

    Young Rang Uhm

    2016-06-01

    Full Text Available A betavoltaic battery was prepared using radioactive 63Ni attached to a three-dimensional single trenched P–N absorber. The optimum thickness of a 63Ni layer was determined to be approximately 2 μm, considering the minimum self-shielding effect of beta particles. Electroplating of radioactive 63Ni on a nickel (Ni foil was carried out at a current density of 20 mA/cm2. The difference of the short-circuit currents (Isc between the pre- and postdeposition of 63Ni (16.65 MBq on the P–N junction was 5.03 nA, as obtained from the I–V characteristics. An improved design with a sandwich structure was provided for enhancing performance.

  12. Energy and Rate Determinations to Activate the C-C σ-BOND of Acetone by Gaseous NI^+

    Science.gov (United States)

    Castleberry, Vanessa A.; Dee, S. Jason; Villarroel, Otsmar J.; Laboren, Ivanna E.; Frey, Sarah E.; Bellert, Darrin J.

    2009-06-01

    A unique application of a custom fabricated photodissociation spectrometer permits the determination of thermodynamic properties (activation energies), reaction rates, and mechanistic details of bare metal cation mediated C-C σ-bond activation in the gas phase. Specifically, the products and rates resulting from the unimolecular decomposition of the Ni^+Acetone (Ni^+Ac) adduct are monitored after absorption of a known amount of energy. The three dissociative products which are observed in high yield are Ni^+, Ni^+CO, and CH3CO^+. The latter two fragment ions result from the activation of a C-C σ-bond. It was found that minimally 14 000 cm^{-1} of energy must be deposited into the adduct ion to induce C-C bond breakage. Preliminary results for the Ni^+ activation of the C-C σ-bond of acetone indicate that there are (at least) two low energy reaction coordinates leading to C-C bond breakage. The lower energy pathway emerges from the doublet ground state with an upper limit to the activation energy of 14 000 cm^{-1} and reaction rate ≈0.14 molecules/μs. The higher energy path is assumed to be along the quartet reaction coordinate with a minimum activation energy of 18 800 cm^{-1} (relative to the ground state) and a slightly slower reaction rate.

  13. Impurity levels and fatigue lives of pseudoelastic NiTi shape memory alloys

    International Nuclear Information System (INIS)

    Rahim, M.; Frenzel, J.; Frotscher, M.; Pfetzing-Micklich, J.; Steegmüller, R.; Wohlschlögel, M.; Mughrabi, H.; Eggeler, G.

    2013-01-01

    In the present work we show how different oxygen (O) and carbon (C) levels affect fatigue lives of pseudoelastic NiTi shape memory alloys. We compare three alloys, one with an ultrahigh purity and two which contain the maximum accepted levels of C and O. We use bending rotation fatigue (up to cycle numbers >10 8 ) and scanning electron microscopy (for investigating microstructural details of crack initiation and growth) to study fatigue behavior. High cycle fatigue (HCF) life is governed by the number of cycles required for crack initiation. In the low cycle fatigue (LCF) regime, the high-purity alloy outperforms the materials with higher number densities of carbides and oxides. In the HCF regime, on the other hand, the high-purity and C-containing alloys show higher fatigue lives than the alloy with oxide particles. There is high experimental scatter in the HCF regime where fatigue cracks preferentially nucleate at particle/void assemblies (PVAs) which form during processing. Cyclic crack growth follows the Paris law and does not depend on impurity levels. The results presented in the present work contribute to a better understanding of structural fatigue of pseudoelastic NiTi shape memory alloys

  14. Comparison of doubly labeled water with respirometry at low- and high-activity levels

    International Nuclear Information System (INIS)

    Westerterp, K.R.; Brouns, F.; Saris, W.H.; ten Hoor, F.

    1988-01-01

    In previous studies the doubly labeled water method for measuring energy expenditure in free-living humans has been validated against respirometry under sedentary conditions. In the present investigation, energy expenditure is measured simultaneously with doubly labeled water and respirometry at low- and high-activity levels. Over 6 days, five subjects were measured doing mainly sedentary activities like desk work; their average daily metabolic rate was 1.40 +/- 0.09 (SD) times sleeping metabolic rate. Four subjects were measured twice over 3.5 days, including 2 days with heavy bicycle ergometer work, resulting in an average daily metabolic rate of 2.61 +/- 0.25 (SD) times sleeping metabolic rate. At the low-activity level, energy expenditures from the doubly labeled water method were on the average 1.4 +/- 3.9% (SD) larger than those from respirometry. At the high-activity level, the doubly labeled water method yielded values that were 1.0 +/- 7.0% (SD) lower than those from respirometry. Results demonstrate the utility of the doubly labeled water method for the determination of energy expenditure in the range of activity levels in daily life

  15. Nano-engineered intrapores in nanoparticles of PtNi networks for increased oxygen reduction reaction activity

    Science.gov (United States)

    Ding, Jieting; Ji, Shan; Wang, Hui; Key, Julian; Brett, Dan J. L.; Wang, Rongfang

    2018-01-01

    Network-like metallic alloys of solid nanoparticles have been frequently reported as promising electrocatalysts for fuel cells. The three-dimensional structure of such networks is rich in pores in the form of voids between nanoparticles, which collectively expose a large surface area for catalytic activity. Herein, we present a novel solution to this problem using a precursor comprising a flocculent core-shell PtNi@Ni to produce PtNi network catalysts with nanoparticle intraporosity after carefully controlled electrochemical dealloying. Physical characterization shows a hierarchical level of nanoporosity (intrapores within nanoparticles and pores between them) evolves during the controlled electrochemical dealloying, and that a Pt-rich surface also forms after 22 cycles of Ni leaching. In ORR cycling, the PtNi networks gain 4-fold activity in both jECSA and jmass over a state of the art Pt/C electrocatalyst, and also significantly exceed previously reported PtNi networks. In ORR degradation tests, the PtNi networks also proved stable, dropping by 30.4% and 62.6% in jECSA and jmass respectively. The enhanced performance of the catalyst is evident, and we also propose that the presented synthesis procedure can be generally applied to developing other metallic networks.

  16. Low-field spin dynamics of Cr7Ni and Cr7Ni-Cu-Cr7Ni molecular rings as detected by μsR

    OpenAIRE

    Sanna, S.; Arosio, P.; Bordonali, L.; Adelnia, F.; Mariani, M.; Garlatti, E.; Baines, C.; Amato, A.; Sabareesh, K. P.V.; Timco, G.; Winpenny, R. E.P.; Blundell, S. J.; Lascialfari, A.

    2017-01-01

    Muon spin rotation measurements were used to investigate the spin dynamics of heterometallic Cr7Ni and Cr7Ni-Cu-Cr7Ni molecular clusters. In Cr7Ni the magnetic ions are arranged in a quasiplanar ring and interact via an antiferromagnetic exchange coupling constant J, while Cr7Ni-Cu-Cr7Ni is composed of two Cr7Ni linked by a bridging moiety containing one Cu ion, that induces an inter-ring ferromagnetic interaction J ≪ J. The longitudinal muon relaxation rate λ collected at low magnetic fields...

  17. The relationship between the addition method of the Ni-activator and the sinterability for the Ni-doped W-powder compact

    International Nuclear Information System (INIS)

    Moon, I.H.; Kim, J.S.

    1984-01-01

    The relationship between the nickel size added to tungsten powder and the sinterability was investigated for the Ni-doped W-powder compact. The Ni-added W-powder compact with various particle size ratios of W to Ni were prepared by mechanical mixing as well as by salt solution and reduction method. In the latter method the size of reduced Ni-particle could be controlled by drying rate of salt solution. The smaller the size of nickel particles added to W was, the activatedly sintered W-powder compact has shown higher sinterability in the initial stage of sintering. The dependence of sinterability on the size of Ni-activator could be partly explained by some physical characteristics of Ni-activator at sintering temperature. (Auth.)

  18. Stochastic estimation of nuclear level density in the nuclear shell model: An application to parity-dependent level density in 58Ni

    Directory of Open Access Journals (Sweden)

    Noritaka Shimizu

    2016-02-01

    Full Text Available We introduce a novel method to obtain level densities in large-scale shell-model calculations. Our method is a stochastic estimation of eigenvalue count based on a shifted Krylov-subspace method, which enables us to obtain level densities of huge Hamiltonian matrices. This framework leads to a successful description of both low-lying spectroscopy and the experimentally observed equilibration of Jπ=2+ and 2− states in 58Ni in a unified manner.

  19. Porous bimetallic PdNi catalyst with high electrocatalytic activity for ethanol electrooxidation.

    Science.gov (United States)

    Feng, Yue; Bin, Duan; Yan, Bo; Du, Yukou; Majima, Tetsuro; Zhou, Weiqiang

    2017-05-01

    Porous bimetallic PdNi catalysts were fabricated by a novel method, namely, reduction of Pd and Ni oxides prepared via calcining the complex chelate of PdNi-dimethylglyoxime (PdNi-dmg). The morphology and composition of the as-prepared PdNi were investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Furthermore, the electrochemical properties of PdNi catalysts towards ethanol electrooxidation were also studied by electrochemical impedance spectrometry (EIS), cyclic voltammetry (CV) and chronoamperometry (CA) measurement. In comparison with porous Pd and commercial Pd/C catalysts, porous structural PdNi catalysts showed higher electrocatalytic activity and durability for ethanol electrooxidation, which may be ascribed to Pd and Ni property, large electroactive surface area and high electron transfer property. The Ni exist in the catalyst in the form of the nickel hydroxides (Ni(OH) 2 and NiOOH) which have a high electron and proton conductivity enhances the catalytic activity of the catalysts. All results highlight the great potential application of the calcination-reduction method for synthesizing high active porous PdNi catalysts in direct ethanol fuel cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. More active and sulfur resistant bimetallic Pd-Ni catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Betti, Carolina; Carrara, Nicolás; Badano, Juan; Lederhos, Cecilia; Vera, Carlos; Quiroga, Mónica, E-mail: mquiroga@fiq.unl.edu.ar [Instituto de Investigaciones en Catálisis y Petroquímica, INCAPE (FIQ-UNL, CONICET), Santa Fe (Argentina)

    2018-02-15

    The influence of the kind of metal precursor and the sequence of impregnation on the properties of Pd-Ni catalysts was evaluated during the test reaction of selective hydrogenation of styrene to ethylbenzene by means of physicochemical characterization. The focus was put on the final hydrogenating activity and the resistance to deactivation by sulfide compounds (thiophene). The used techniques of characterization were ICP, XPS, XDR, TPR, CO chemisorption and TEM. XPS results indicated the presence of different Pd species: Pd{sup δ-}, Pd{sup 0} and Pd{sup δ+}. In the case of the Ni containing catalysts, Ni{sup 0} and NiO species were also detected. These palladium and nickel species would be responsible of the variation of activity and sulfur resistance of the catalysts. NiClPd catalysts had a higher resistance to deactivation by sulfur poisoning. This was associated to a higher concentration of Pd{sup η+}Cl{sub x}O{sub y} species that would prevent the adsorption of thiophene by both steric and electronic effects. It could also be due to the lower concentration of Pd{sup 0} and Ni{sup 0} on these catalysts, as compared to those shown by the PdNiCl catalysts. Both the Pd{sup 0} and Ni{sup 0} species are more prone to poisoning because of their higher electronic availability. (author)

  1. Synthesis and electrochemical performances of LiNiCuZn oxides as anode and cathode catalyst for low temperature solid oxide fuel cell.

    Science.gov (United States)

    Jing, Y; Qin, H; Liu, Q; Singh, M; Zhu, B

    2012-06-01

    Low temperature solid oxide fuel cell (LTSOFC, 300-600 degrees C) is developed with advantages compared to conventional SOFC (800-1000 degrees C). The electrodes with good catalytic activity, high electronic and ionic conductivity are required to achieve high power output. In this work, a LiNiCuZn oxides as anode and cathode catalyst is prepared by slurry method. The structure and morphology of the prepared LiNiCuZn oxides are characterized by X-ray diffraction and field emission scanning electron microscopy. The LiNiCuZn oxides prepared by slurry method are nano Li0.28Ni0.72O, ZnO and CuO compound. The nano-crystallites are congregated to form ball-shape particles with diameter of 800-1000 nm. The LiNiCuZn oxides electrodes exhibits high ion conductivity and low polarization resistance to hydrogen oxidation reaction and oxygen reduction reaction at low temperature. The LTSOFC using the LiNiCuZn oxides electrodes demonstrates good cell performance of 1000 mW cm(-2) when it operates at 470 degrees C. It is considered that nano-composite would be an effective way to develop catalyst for LTSOFC.

  2. Low-energy charge transfer excitations in NiO

    International Nuclear Information System (INIS)

    Sokolov, V I; Yermakov, A Ye; Uimin, M A; Gruzdev, N B; Pustovarov, V A; Churmanov, V N; Ivanov, V Yu; Sokolov, P S; Baranov, A N; Moskvin, A S

    2012-01-01

    Comparative analysis of photoluminescence (PL) and photoluminescence excitation (PLE) spectra of NiO poly- and nanocrystals in the spectral range 2-5.5 eV reveals two PLE bands peaked near 3.7 and 4.6 eV with a dramatic rise in the low-temperature PLE spectral weight of the 3.7 eV PLE band in the nanocrystalline NiO as compared with its polycrystalline counterpart. In frames of a cluster model approach we assign the 3.7 eV PLE band to the low-energy bulk-forbidden p-d (t 1g (π)-e g ) charge transfer (CT) transition which becomes the allowed one in the nanocrystalline state while the 4.6 eV PLE band is related to a bulk allowed d-d (e g -e g ) CT transition scarcely susceptible to the nanocrystallization. The PLE spectroscopy of the nanocrystalline materials appears to be a novel informative technique for inspection of different CT transitions.

  3. Bioaccumulation of sediment-bound Cr-51, Ni-63 and C-14 by benthic invertebrates

    International Nuclear Information System (INIS)

    Kumblad, L.; Bradshaw, C.; Giled, M.

    2004-01-01

    Sediments in many areas of the Baltic Sea are highly contaminated with particle-reactive trace metals and/or radionuclides. These may be re-mobilised into aquatic food chains by bioaccumulation into benthic organisms. In this study, we examined and compared assimilation efficiencies and bioaccumulation kinetics (rates of uptake and elimination) of sediment-associated Cr-51, Ni-63 and organic-associated C- 14 in three common benthic invertebrates from the Baltic Sea (the bivalve Macoma balthica, the amphipod Monoporeia affinis and the priapulid worm Halicryptus spinulosus). There were differences between animals and radionuclides in both the rate of uptake and elimination and the maximum amount accumulated. Understanding how and to what degree different deposit-feeding benthic invertebrates are exposed to and bio-accumulate sediment-associated metals are important for both ecological risk assessment and management decisions in coastal ecosystems. (author)

  4. Study of surface activation of PET by low energy (keV) Ni+ and N+ ion implantation

    International Nuclear Information System (INIS)

    Nathawat, Rashi; Kumar, Anil; Kulshrestha, V.; Vijay, Y.K.; Kobayashi, T.; Kanjilal, D.

    2008-01-01

    Polyethyleneterephthalate (PET) has been modified by 100 keV Ni + and N + ions using metal ion from volatile compound (MIVOC) ion source to fluence ranging from 1 x 10 14 to 1 x 10 16 ions/cm 2 . The increasing application of polymeric material in technological and scientific field has motivated the use of surface treatment to modify the physical and chemical properties of polymer surfaces. When a material is exposed to ionization radiation, it suffers damage leading to surface activation depending on the type. The surface morphology was observed by atomic force microscopy (AFM). That show the roughness increases with fluence in both the cases. The Ni particles as precipitation in PET were observed by cross-section transmission electron microscopy (XTEM). The optical band gap (E g ) deduced from absorption spectra; was calculated by Tau'c relation. Raman spectroscopy shows quantitatively the chemical nature at the damage caused by the Ni + and N + bombardment. The ration of I D /I G shows graphite-like structure is formed on the surface. A layer of hydrogenated amorphous carbon is formed on the surface, which has confirmed by XPS results also.

  5. Low cycle fatigue behavior of polycrystalline NiAl at 300 and 1000 K

    Science.gov (United States)

    Lerch, Bradley A.; Noebe, Ronald D.

    1993-01-01

    The low cycle fatigue behavior of polycrystalline NiAl was determined at 300 and 1000 K - temperatures below and above the brittle- to-ductile transition temperature (BDTT). Fully reversed, plastic strain-controlled fatigue tests were conducted on two differently fabricated alloy samples: hot isostatically pressed (HIP'ed) prealloyed powder and hot extruded castings. HIP'ed powder (HP) samples were tested only at 1000 K, whereas the more ductile cast-and-extruded (C+E) NiAl samples were tested at both 1000 and 300 K. Plastic strain ranges of 0.06 to 0.2 percent were used. The C+E NiAl cyclically hardened until fracture, reaching stress levels approximately 60 percent greater than the ultimate tensile strength of the alloy. Compared on a strain basis, NiAl had a much longer fatigue life than other B2 ordered compounds in which fracture initiated at processing-related defects. These defects controlled fatigue life at 300 K, with fracture occurring rapidly once a critical stress level was reached. At 1000 K, above the BDTT, both the C+E and HP samples cyclically softened during most of the fatigue tests in air and were insensitive to processing defects. The processing method did not have a major effect on fatigue life; the lives of the HP samples were about a factor of three shorter than the C+E NiAl, but this was attributed to the lower stress response of the C+E material. The C+E NiAl underwent dynamic grain growth, whereas the HP material maintained a constant grain size during testing. In both materials, fatigue life was controlled by intergranular cavitation and creep processes, which led to fatigue crack growth that was primarily intergranular in nature. Final fracture by overload was transgranular in nature. Also, HP samples tested in vacuum had a life three times longer than their counterparts tested in air and, in contrast to those tested in air, hardened continuously over half of the sample life, thereby indicating an environmentally assisted fatigue damage

  6. Nickel accumulation and storage in bradyrhizobium japonicum

    International Nuclear Information System (INIS)

    Maier, R.J.; Pihl, T.D.; Stults, L.; Sray, W.

    1990-01-01

    Hydrogenase-depressed (chemolithotrophic growth conditions) and heterotrophically grown cultures of Bradyrhizobium japonicum accumulated nickel about equally over a 3-h period. Both types of cultures accumulated nickel primarily in a form that was not exchangeable with NiCl 2 , and they accumulated much more Ni than would be needed for the Ni-containing hydrogenase. The nickel accumulated by heterotrophically incubated cultures could later be mobilized to allow active hydrogenase synthesis during derepression in the absence of nickel, while cells both grown with Ni and the derepressed without nickel had low hydrogenase activities. The level of activity in cells grown with Ni and then derepressed without nickel was about the same as that in cultures derepressed in the presence of nickel. The Ni accumulated by heterotrophically grown cultures was associated principally with soluble proteins rather than particulate material, and this Ni was not lost upon dialyzing an extract containing the soluble proteins against either Ni-containing or EDTA-containing buffer. However, this Ni was lost upon pronase or low pH treatments. The soluble Ni-binding proteins were partially purified by gel filtration and DEAE chromatography. They were not antigenically related to hydrogenase peptides. Much of the 63 Ni eluted as a single peak of 48 kilodaltons. Experiments involving immunuprecipitation of 63 Ni-containing hydrogenase suggested that the stored source of Ni in heterotrophic cultures that could later be mobilized into hydrogenase resided in the nonexchangeable Ni-containing fraction rather than in loosely bound or ionic forms

  7. USDOE activities in low-level radioactive waste treatment

    International Nuclear Information System (INIS)

    Vath, J.E.

    1981-01-01

    This paper describes current research, development and demonstration (R, D and D) programs sponsored by the US Department of Energy in the area of low-level radioactive waste treatment. During the twelve month period ending September 30, 1981, 14 prime US Department of Energy contractors were involved with over 40 low-level radioactive waste disposal technology projects. Three specific projects or task areas have been selected for discussion to illustrate new and evolving technologies, and application of technology developed in other waste management areas to low-level waste treatment. The areas to be discussed include a microwave plasma torch incinerator, application of waste vitrification, and decontamination of metal waste by melting

  8. Physical Activity Levels During Acute Inpatient Admission After Hip Fracture are Very Low.

    Science.gov (United States)

    Davenport, Sarah J; Arnold, Meaghan; Hua, Carol; Schenck, Amie; Batten, Sarah; Taylor, Nicholas F

    2015-09-01

    Hip fractures are very common in older adults and result in serious health consequences. Early mobilization post-surgical intervention for hip fractures is very important. The purpose of this study was to determine physical activity levels during an acute inpatient admission of patients after surgery for hip fracture. The observational study was completed on an orthopaedic ward in an acute general hospital. Twenty patients (18 women, mean age ± standard deviation, 79.1 ± 9.3 years) post-surgical intervention for a hip fracture were included. Physical activity levels were measured using an accelerometer to record the percentage of time spent in lying/sitting, standing and walking, number of steps taken and average energy expenditure. Physical activity levels were extremely low, with participants spending an average of 99% of the day either lying or sitting and a little more than 1% of the day either standing or walking (16 min). Participants took an average of 35.7 ± 80.4 steps per day. Patients received more physiotherapy intervention on weekdays compared with weekends. There was no significant difference in activity levels between weekdays to weekends. No measures of physical activity were associated with length of stay. A mild to moderate association (r = 0.26-0.41) was observed between the measures of physical activity and the amount of physiotherapy received during the weekdays. Physical activity levels during an acute inpatient admission surgery for hip fracture are very low. Patients may have difficulty completing basic activities of daily living post-discharge into the community. Physical activity should be optimized as early in the rehabilitation process as able. Copyright © 2014 John Wiley & Sons, Ltd.

  9. Microstructural Characterization of Clad Interface in Welds of Ni-Cr-Mo High Strength Low Alloy Steel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hong-Eun; Kim, Min-Chul; Lee, Ho-Jin; Kim, Keong-Ho [KAERI, Daejeon (Korea, Republic of); Lee, Ki-Hyoung [KAIST, Daejeon (Korea, Republic of); Lee, Chang-Hee [Hanyang Univ., Seoul (Korea, Republic of)

    2011-08-15

    SA508 Gr.4N Ni-Cr-Mo low alloy steel, in which Ni and Cr contents are higher than in commercial SA508 Gr.3 Mn-Mo-Ni low alloy steels, may be a candidate reactor pressure vessel (RPV) material with higher strength and toughness from its tempered martensitic microstructure. The inner surface of the RPV is weld-cladded with stainless steels to prevent corrosion. The goal of this study is to evaluate the microstructural properties of the clad interface between Ni-Cr-Mo low alloy steel and stainless weldment, and the effects of post weld heat treatment (PWHT) on the properties. The properties of the clad interface were compared with those of commercial Mn-Mo-Ni low alloy steel. Multi-layer welding of model alloys with ER308L and ER309L stainless steel by the SAW method was performed, and then PWHT was conducted at 610°C for 30 h. The microstructural changes of the clad interface were analyzed using OM, SEM and TEM, and micro-Vickers hardness tests were performed. Before PWHT, the heat affected zone (HAZ) showed higher hardness than base and weld metals due to formation of martensite after welding in both steels. In addition, the hardness of the HAZ in Ni-Cr-Mo low alloy steel was higher than that in Mn-Mo-Ni low alloy steel due to a comparatively high martensite fraction. The hardness of the HAZ decreased after PWHT in both steels, but the dark region was formed near the fusion line in which the hardness was locally high. In the case of Mn-Mo-Ni low alloy steel, formation of fine Cr-carbides in the weld region near the fusion line by diffusion of C from the base metal resulted in locally high hardness in the dark region. However, the precipitates of the region in the Ni-Cr-Mo low alloy steel were similar to that in the base metal, and the hardness in the region was not greatly different from that in the base metal.

  10. Microstructural Characterization of Clad Interface in Welds of Ni-Cr-Mo High Strength Low Alloy Steel

    International Nuclear Information System (INIS)

    Kim, Hong-Eun; Kim, Min-Chul; Lee, Ho-Jin; Kim, Keong-Ho; Lee, Ki-Hyoung; Lee, Chang-Hee

    2011-01-01

    SA508 Gr.4N Ni-Cr-Mo low alloy steel, in which Ni and Cr contents are higher than in commercial SA508 Gr.3 Mn-Mo-Ni low alloy steels, may be a candidate reactor pressure vessel (RPV) material with higher strength and toughness from its tempered martensitic microstructure. The inner surface of the RPV is weld-cladded with stainless steels to prevent corrosion. The goal of this study is to evaluate the microstructural properties of the clad interface between Ni-Cr-Mo low alloy steel and stainless weldment, and the effects of post weld heat treatment (PWHT) on the properties. The properties of the clad interface were compared with those of commercial Mn-Mo-Ni low alloy steel. Multi-layer welding of model alloys with ER308L and ER309L stainless steel by the SAW method was performed, and then PWHT was conducted at 610°C for 30 h. The microstructural changes of the clad interface were analyzed using OM, SEM and TEM, and micro-Vickers hardness tests were performed. Before PWHT, the heat affected zone (HAZ) showed higher hardness than base and weld metals due to formation of martensite after welding in both steels. In addition, the hardness of the HAZ in Ni-Cr-Mo low alloy steel was higher than that in Mn-Mo-Ni low alloy steel due to a comparatively high martensite fraction. The hardness of the HAZ decreased after PWHT in both steels, but the dark region was formed near the fusion line in which the hardness was locally high. In the case of Mn-Mo-Ni low alloy steel, formation of fine Cr-carbides in the weld region near the fusion line by diffusion of C from the base metal resulted in locally high hardness in the dark region. However, the precipitates of the region in the Ni-Cr-Mo low alloy steel were similar to that in the base metal, and the hardness in the region was not greatly different from that in the base metal.

  11. Galvanic displacement synthesis of Al/Ni core–shell pigments and their low infrared emissivity application

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Le, E-mail: yuanle.cn@gmail.com [Center for Advanced Materials and Energy, Xihua University, Chengdu, 610039 (China); National Engineering Research Center of Electromagnetic Radiation Control Materials, UESTC, Chengdu, 610054 (China); Hu, Juan [Center for Advanced Materials and Energy, Xihua University, Chengdu, 610039 (China); Weng, Xiaolong [National Engineering Research Center of Electromagnetic Radiation Control Materials, UESTC, Chengdu, 610054 (China); Zhang, Qingyong [Center for Advanced Materials and Energy, Xihua University, Chengdu, 610039 (China); Deng, Longjiang [National Engineering Research Center of Electromagnetic Radiation Control Materials, UESTC, Chengdu, 610054 (China)

    2016-06-15

    We have successfully developed a magnetic Al/Ni core–shell pigment via a galvanic displacement reaction to obtain low infrared emissivity pigment with low lightness and visible light reflectance. Al/Ni core–shell particles were prepared via a simple one-step synthetic method where Ni was deposited onto the Al surface at the expense of Al atoms. The influence of pH and the amount of NH{sub 4}F complexing agent on phase structure, surface morphology, optical and magnetic properties were studied systematically. The neutral condition and high concentration of NH{sub 4}F forms smooth, flat, uniform and dense Ni shell on the surface of flake Al particles, which can significantly reduce the lightness and visible light reflectance but slightly increase the infrared emissivity. When the core–shell pigments are prepared in neutral pH solution at NH{sub 4}F = 11.2 g/L, the lightness (L{sup *}) and visual light reflectivity can be reduced by 12.6 and 0.46, respectively versus uncoated flake Al pigments, but the infrared emissivity is only increased by 0.02. The color changes from brilliant silver to gray black and the saturation magnetization value is 6.59 emu/g. Therefore, these Al/Ni magnetic composite pigments can be used as a novel low infrared emissivity pigment to improve the multispectral stealth performance of low-E coatings in the visual, IR and Radar wavebands. - Highlights: • Prepared magnetic Al/Ni core–shell pigment with low lightness and low emissivity. • Used one-pot galvanic displacement reaction to form smooth and dense Ni shell. • Show enhanced stealth performance in the visual, IR and Radar wavebands. • The lightness and visible light reflectance was decreased by 12.6 and 0.46. • But the infrared emissivity was only increases by 0.02.

  12. Galvanic displacement synthesis of Al/Ni core–shell pigments and their low infrared emissivity application

    International Nuclear Information System (INIS)

    Yuan, Le; Hu, Juan; Weng, Xiaolong; Zhang, Qingyong; Deng, Longjiang

    2016-01-01

    We have successfully developed a magnetic Al/Ni core–shell pigment via a galvanic displacement reaction to obtain low infrared emissivity pigment with low lightness and visible light reflectance. Al/Ni core–shell particles were prepared via a simple one-step synthetic method where Ni was deposited onto the Al surface at the expense of Al atoms. The influence of pH and the amount of NH_4F complexing agent on phase structure, surface morphology, optical and magnetic properties were studied systematically. The neutral condition and high concentration of NH_4F forms smooth, flat, uniform and dense Ni shell on the surface of flake Al particles, which can significantly reduce the lightness and visible light reflectance but slightly increase the infrared emissivity. When the core–shell pigments are prepared in neutral pH solution at NH_4F = 11.2 g/L, the lightness (L"*) and visual light reflectivity can be reduced by 12.6 and 0.46, respectively versus uncoated flake Al pigments, but the infrared emissivity is only increased by 0.02. The color changes from brilliant silver to gray black and the saturation magnetization value is 6.59 emu/g. Therefore, these Al/Ni magnetic composite pigments can be used as a novel low infrared emissivity pigment to improve the multispectral stealth performance of low-E coatings in the visual, IR and Radar wavebands. - Highlights: • Prepared magnetic Al/Ni core–shell pigment with low lightness and low emissivity. • Used one-pot galvanic displacement reaction to form smooth and dense Ni shell. • Show enhanced stealth performance in the visual, IR and Radar wavebands. • The lightness and visible light reflectance was decreased by 12.6 and 0.46. • But the infrared emissivity was only increases by 0.02.

  13. Comparative study of electroless Co-Ni-P plating on Tencel fabric by Co0-based and Ni0-based activation for electromagnetic interference shielding

    Science.gov (United States)

    Bi, Siyi; Zhao, Hang; Hou, Lei; Lu, Yinxiang

    2017-10-01

    The primary objective of this research work was to develop high-performance conductive fabrics with desired electromagnetic interference (EMI) shielding effectiveness (SE), excellent durability and improved corrosion resistance. Such conductive fabrics were fabricated by combining an ultra-low-cost electroless plating method with an alkoxy silane self-assembly technology, which involved successive steps of modification, activation, Co-Ni-P coating deposition and 3-aminopropyltrimethoxysilane (APTMS) thin coatings assembling. Malic acid (MA) was selected to modify the pristine Tencel (TS) substrates, and the probably interaction mechanism was investigated by FT-IR measurement. Co0 and Ni0 nanoparticles (NPs) were used as the activators to initiate electroless plating, respectively, and thereby two categories of Co-Ni-P coatings with different Co/Ni atomic ratio were obtained. Both of them presented compact morphologies and preferential (1 1 1) crystal orientation, which were validated by FE-SEM and XRD measurements. Owing to the lower square resistance and higher magnetic properties, the Co-Ni-P coated fabric activated by Co0 activator showed a higher EMI SE (18.2-40.1 dB) at frequency of 30-1000 MHz. APTMS thin coatings were then assembled on the top of alloy coated fabrics to act as anti-corrosion barriers. Electrochemical polarization measurement in 3.5 wt.% NaCl solution showed that top-APTMS coated conductive fabric exhibited a higher corrosion resistance than the one in absence of APTMS assembly. Overall, the whole process of fabrication could be performed in several hours (or less) without any specialized equipment, which shows a great potential as EMI shielding fabrics in mass-production.

  14. One method of measure low activity level of α, β

    International Nuclear Information System (INIS)

    Sun Shimin

    2003-01-01

    In this paper it is described that several method of measure low activity level of Alpha and Beta, and an circuit diagram for signal of Alpha and Beta to differentiate with method of wave shape identification. With the method, the signal of Beta did not interfere any signal to the count-way of Alpha. For adopted the technology the model JA-3502 of eight detectors of low background Alpha and Beta measuring instrument only have 2.65 x 10 -4 cpm/cm 2 background count rate at count-way of Alpha. Opposite the model FJ-2600 middle area low background Alpha and Beta measuring instrument have 1.27 x 10 -3 cpm/cm 2 background count rate at count-way of Alpha. The latter is 5 times of other

  15. The activation energy for loop growth in Cu and Cu-Ni alloys

    International Nuclear Information System (INIS)

    Barlow, P.; Leffers, T.; Singh, B.N.

    1978-08-01

    The apparent activation energy for the growth of interstitial dislocation loops in copper, Cu-1%Ni, Cu-2%Ni, and Cu-5%Ni during high voltage electron microscope irradiation was determined. The apparent activation energy for loop growth in all these materials can be taken to be 0.34eV+-0.02eV. This value together with the corresponding value of 0.44eV+-0.02eV determined earlier for Cu-10%Ni is discussed with reference to the void growth rates observed in these materials. The apparent activation energy for loop growth in copper (and in Cu-1%Ni that has a void growth rate similar to that in pure copper) is interpreted as twice the vacancy migration energy (indicating that divacancies do not play any significant role). For the materials with higher Ni content (in which the void growth rate is much lower than that in Cu and Cu-1%Ni) the measured apparent activation energy is interpreted to be characteristic of loops positioned fairly close to the foil surface and not of loops in ''bulk material''. From the present results in combination with the earlier results for Cu-10%Ni it is concluded that interstitial trapping is the most likely explanation of the reduced void growth rate in Cu-Ni alloys. (author)

  16. Influence of sliding friction on leveling force of superelastic NiTi arch wire: A computational analysis

    Science.gov (United States)

    Razali, M. F.; Mahmud, A. S.; Mokhtar, N.; Abdullah, J.

    2017-10-01

    This study investigated the influence of sliding friction toward the effective force of superelastic NiTi arch wire applied in orthodontic bracing for tooth leveling. A three-dimensional finite-element model integrated with superelastic subroutine and contact interaction was used to predict the contribution of friction on force-deflection curve of NiTi wire in three brackets bending configuration. It was found that the friction between the wire and the bracket increased proportionally as a function of wire deflection, thus transforming the constant force characteristic of NiTi material into a slope. The highest magnitude of sliding friction was measured to be 3.1 N and 2.2 N with respect to the activation and deactivation of the arch wire.

  17. Low temperature phase transition of the stoichiometric Ln2NiO4 oxides

    International Nuclear Information System (INIS)

    Fernandez, F.; Saez-Puche, R.; Botto, I.L.; Baran, E.J.

    1991-01-01

    In this paper we will present a comparative study of the structural phase transition in Ln 2 NiO 4 oxides, by means of neutron diffraction and infrared(IR) spectroscopy. In the Ln 2 NiO 4 oxides (Ln=La, Pr and Nd), there is a low temperature structural phase transition from the orthorhombic symmetry to a tetragonal phase, of first order character. The IR spectra show, at low temperature, a splitting of the bands related with the stretching Ni-O, strongly correlated with the phase transformation. From the neutron data, the phase transition can be visualized as a sudden tilt of the nickel octahedra

  18. Measurement of the GMR in the Unstable 56Ni Nucleus using the Active Target Maya

    International Nuclear Information System (INIS)

    Monrozeau, C.; Khan, E.; Blumenfeld, Y.; Mittig, W.; Beaumel, D.; Caamano, M.; Cortina-Gil, D.; Demonchy, C.E.; Frascaria, N.; Garg, U.; Gelin, M.; Gillibert, A.; Gupta, D.; Marechal, F.; Obertelli, A.; Roussel-Chomaz, P.; Scarpaci, J.-A.

    2007-01-01

    The measurement of the Isoscalar Giant Monopole Resonance(GMR) in unstable nuclei remains a major experimental challenge due to low radioactive beam intensities and unfavourable conditions in reverse kinematics. At GANIL, we have tested a new experimental method based on the unique capabilities of the active target Maya to probe the GMR by the inelastic scattering reaction 56 Ni(d,d') at 50 AMeV. The preliminary excitation energy spectrum of 56 Ni presents a bump between 12 and 25 MeV where isoscalar resonances are expected

  19. Effect of Cu{sup 2+} and Ni{sup 2+} substitution at the Mn site in (La{sub 0.63}Ca{sub 0.37})MnO{sub 3}: A neutron powder diffraction investigation

    Energy Technology Data Exchange (ETDEWEB)

    Martinelli, A., E-mail: alberto.martinelli@spin.cnr.it [CNR-SPIN, C.so Perrone 24, 16152 Genova (Italy); Ferretti, M. [CNR-SPIN, C.so Perrone 24, 16152 Genova (Italy); Dipartimento di Chimica e Chimica Industriale, Università di Genova, Via Dodecaneso 31, 16146 Genova (Italy); Castellano, C. [Università degli Studi di Milano, Dipartimento di Chimica Strutturale e Stereochimica Inorganica, Via G. Venezian 21, 20133 Milano (Italy); Cimberle, M.R. [IMEM-CNR, Via Dodecaneso 33, 16146 Genova (Italy); Ritter, C. [Institute Laue—Langevin, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9 (France)

    2013-04-15

    The crystal and magnetic structures of the (La{sub 0.63}Ca{sub 0.37})(Mn{sub 1−x}TM{sub x})O{sub 3} compounds (x=0.00, 0.03, 0.08; TM=Cu{sup 2+}, Ni{sup 2+}) were investigated between 5 K and 300 K by means of dc magnetic measurements and neutron powder diffraction analysis followed by Rietveld refinement. Both substituting cations lead to a reduction of the long range ferromagnetic ordering temperature; ferromagnetism is strongly suppressed in the 8% Cu-substituted sample, where long- and short-range FM magnetic orders coexist together with short-range A-type AFM order. This particular feature can be related to the Jahn–Teller character of Cu{sup 2+}, absent in Ni{sup 2+}, and suggests the occurrence of a quantum critical point in the (La{sub 0.63}Ca{sub 0.37})(Mn{sub 1−x}Cu{sub x})O{sub 3} system. - Graphical abstract: Rietveld refinement plot of (La{sub 0.63}Ca{sub 0.37})(Mn{sub 0.92}Cu{sub 0.08})O{sub 3} showing in the inset the coexistence of broad A-type AFM peaks with FM ones. Highlights: ► (La{sub 0.63}Ca{sub 0.37})MnO{sub 3} was substituted with Ni and Cu. ► Neutron powder diffraction and Rietveld refinement were carried out. ► A quantum critical point possibly occurs in the (La{sub 0.63}Ca{sub 0.37})(Mn{sub 1−x}Cu{sub x})O{sub 3} system.

  20. Electronic Structure Control of Tungsten Oxide Activated by Ni for Ultrahigh-Performance Supercapacitors.

    Science.gov (United States)

    Meng, Tian; Kou, Zongkui; Amiinu, Ibrahim Saana; Hong, Xufeng; Li, Qingwei; Tang, Yongfu; Zhao, Yufeng; Liu, Shaojun; Mai, Liqiang; Mu, Shichun

    2018-04-17

    Tuning the electron structure is of vital importance for designing high active electrode materials. Here, for boosting the capacitive performance of tungsten oxide, an atomic scale engineering approach to optimize the electronic structure of tungsten oxide by Ni doping is reported. Density functional theory calculations disclose that through Ni doping, the density of state at Fermi level for tungsten oxide can be enhanced, thus promoting its electron transfer. When used as electrode of supercapacitors, the obtained Ni-doped tungsten oxide with 4.21 at% Ni exhibits an ultrahigh mass-specific capacitance of 557 F g -1 at the current density of 1 A g -1 and preferable durability in a long-term cycle test. To the best of knowledge, this is the highest supercapacitor performance reported so far in tungsten oxide and its composites. The present strategy demonstrates the validity of the electronic structure control in tungsten oxide via introducing Ni atoms for pseudocapacitors, which can be extended to other related fields as well. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Determination of 90Sr in low-level radioactive wastes using extraction chromatography and LSC

    International Nuclear Information System (INIS)

    Temba, Eliane S.C.; Reis Junior, Aluisio S.; Mingote, Raquel M.; Monteiro, Roberto P.G.

    2009-01-01

    A procedure for the determination of 90 Sr in low-level radioactive wastes is presented in this work. It is a part of a methodology developed for the sequential radiochemical separation of radionuclides in low-level radioactive wastes. These radionuclides comprises the actinides and 55 Fe, 63 Ni and 90 Sr, classified as difficult-to-measure (DTM) radionuclides in the radioactive waste characterization, because they cannot be measured by direct measurements, like gamma spectrometry. A variety of methods have been reported in the literature, based on precipitation, liquid-liquid extraction and ion exchange. In this work, the separation was carried out using precipitation and extraction chromatography using the Sr Resin (Eichrom). This resin is strontium-selective, the extractant is a crown ether-derivative immobilized on an inert polymeric support. The 90 Sr eluted from column was measured by LSC. The counting was carried out within 5 hours of the start of yttrium ingrowth to minimize interferences from 90 Y. The counting efficiency was calculated by using a 90 Sr standard solution purified by the specific resin. The chemical yield of the procedure was determined gravimetrically by the addition of a stable Sr carrier. Optimum conditions for the pretreatment, separation and LSC setting were determined using simulated samples. This procedure showed to be rapid and achieved a good chemical recovery, with an average of 84 %, and a detection limit of 0.6 Bq L -1 . (author)

  2. Transcriptional activator TAp63 is upregulated in muscular atrophy during ALS and induces the pro-atrophic ubiquitin ligase Trim63

    Science.gov (United States)

    von Grabowiecki, Yannick; Abreu, Paula; Blanchard, Orphee; Palamiuc, Lavinia; Benosman, Samir; Mériaux, Sophie; Devignot, Véronique; Gross, Isabelle; Mellitzer, Georg; Gonzalez de Aguilar, José L; Gaiddon, Christian

    2016-01-01

    Mechanisms of muscle atrophy are complex and their understanding might help finding therapeutic solutions for pathologies such as amyotrophic lateral sclerosis (ALS). We meta-analyzed transcriptomic experiments of muscles of ALS patients and mouse models, uncovering a p53 deregulation as common denominator. We then characterized the induction of several p53 family members (p53, p63, p73) and a correlation between the levels of p53 family target genes and the severity of muscle atrophy in ALS patients and mice. In particular, we observed increased p63 protein levels in the fibers of atrophic muscles via denervation-dependent and -independent mechanisms. At a functional level, we demonstrated that TAp63 and p53 transactivate the promoter and increased the expression of Trim63 (MuRF1), an effector of muscle atrophy. Altogether, these results suggest a novel function for p63 as a contributor to muscular atrophic processes via the regulation of multiple genes, including the muscle atrophy gene Trim63. DOI: http://dx.doi.org/10.7554/eLife.10528.001 PMID:26919175

  3. The optimization of the analysis of nickel-63 in urine

    International Nuclear Information System (INIS)

    Kramer, G.H.

    1981-05-01

    A method has been developed that separates nickel-63 from urine. The subsequent estimation of activity is by liquid scintillation counting. The urine is wet ashed by a new procedure which is much faster than conventional ashing methods. Interfering phosphates are removed prior to a precipitation of Ni as the dimethylglyoxime complex. The effects of the carrier weight, the pH of the phosphate removal step and the pH of the dimethylglyoxime precipiation have been investigated and optimized to give a mean recovery of 97 +- 8% for nickel-63. The detection limit is estimated to be 1.5 pCi (55 mBq) per sample. (author)

  4. Status report on Texas Low-Level Radioactive Waste Disposal Authority activities

    International Nuclear Information System (INIS)

    Avant, R.V. Jr.

    1990-01-01

    In 1981, the Texas Low-Level Radioactive Waste Disposal Authority was created by Article 4590f-1 to site, develop, operate, decommission, and close a low-level radioactive waste disposal facility for Texas generated waste. In 1989, the Authority's act was recodified by the Texas legislature in the Health and Safety Code., Title 5. Sanitation and Environmental Quality, Subtitle D. Nuclear and Radioactive Materials, Chapter 402. The Authority is governed by a Board of Directors appointed by the Governor, composed of a certified health physicist, geologist, attorney, medical doctor, and two private citizens. Under the statute, low-level radioactive waste is defined as any radioactive material with a half-life of 35 years or less or having less than 10 nanocuries per gram of transuranics. Materials with half-lives of greater than 35 years may be classed as low-level waste if special criteria are established by the Texas Department of Health Bureau of Radiation Control. Subsequent sessions of the legislature have amended the act to revise siting criteria, require consideration of state land, create a Citizen's Advisory Committee, incorporate alternative designs, and establish a special low-level radioactive waste account in the state treasury. The Authority began its activities in 1982. The Authority has proposed a site in far West Texas near Fort Hancock, but El Paso County, the neighboring county to the west, has instituted three separate lawsuits to slow or stop the site selection process. Particular attention was paid early in the site selection process to items which could be fatal flaws from a licensing standpoint. This paper discusses the Fort Hancock site description, site evaluation studies, siting issues, waste volume projections, facility design, license application, cost and schedule

  5. Hydrogen insertion effects on the electronic structure of equiatomic MgNi traced by ab initio calculations

    Energy Technology Data Exchange (ETDEWEB)

    Matar, Samir F. [CNRS, ICMCB, UPR 9048, Pessac (France); Bordeaux Univ., Pessac (France). ICMCB, UPR 9048; Al Alam, Adel F.; Ouaini, Naim [Univ. Saint Esprit de Kaslik (USEK), Jounieh (Lebanon). URA GREVE, CSR-USEK

    2013-01-15

    For equiatomic MgNi which can be hydrogenated up to the composition MgNiH{sub 1.6} at an absorption/desorption temperature of 200 C, the effects of hydrogen absorption are approached with the model structures MgNiH, MgNiH{sub 2} and MgNiH{sub 3}. From full geometry optimization and calculated cohesive energies obtained within DFT, the MgNiH{sub 2} composition close to the experimental limit is identified as most stable. Charge density analysis shows an increasingly covalent character of hydrogen: MgNiH(H{sup -0.67}) {yields} MgNiH{sub 2}(H{sup -0.63}) {yields} MgNiH{sub 3}(H{sup -0.55}). While Mg-Ni bonding prevails in MgNi and hydrogenated model phases, extra itinerant low-energy Ni states appear when hydrogen is introduced signaling Ni-H bonding which prevails over Mg-H as evidenced from total energy calculations and chemical bonding analyses. (orig.)

  6. 40 CFR 63.4 - Prohibited activities and circumvention.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Prohibited activities and circumvention... § 63.4 Prohibited activities and circumvention. (a) Prohibited activities. (1) No owner or operator... part. (3)-(5) [Reserved] (b) Circumvention. No owner or operator subject to the provisions of this part...

  7. Electroplated Ni on the PN Junction Semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Joo; Uhm, Young Rang; Son, Kwang Jae; Kim, Jong Bum; Choi, Sang Moo; Park, Jong Han; Hong, Jintae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Nickel (Ni) electroplating was implemented by using a metal Ni powder in order to establish a Ni-63 plating condition on the PN junction semiconductor needed for production of betavoltaic battery. PN junction semiconductors with a Ni seed layer of 500 and 1000 A were coated with Ni at current density from 10 to 50 mA cm{sup 2}. The surface roughness and average grain size of Ni deposits were investigated by XRD and SEM techniques. The roughness of Ni deposit was increased as the current density was increased, and decreased as the thickness of Ni seed layer was increased.

  8. Electroplated Ni on the PN Junction Semiconductor

    International Nuclear Information System (INIS)

    Kim, Jin Joo; Uhm, Young Rang; Son, Kwang Jae; Kim, Jong Bum; Choi, Sang Moo; Park, Jong Han; Hong, Jintae

    2015-01-01

    Nickel (Ni) electroplating was implemented by using a metal Ni powder in order to establish a Ni-63 plating condition on the PN junction semiconductor needed for production of betavoltaic battery. PN junction semiconductors with a Ni seed layer of 500 and 1000 A were coated with Ni at current density from 10 to 50 mA cm 2 . The surface roughness and average grain size of Ni deposits were investigated by XRD and SEM techniques. The roughness of Ni deposit was increased as the current density was increased, and decreased as the thickness of Ni seed layer was increased

  9. National Low-Level Waste Management Program final summary report of key activities and accomplishments for fiscal year 1997

    International Nuclear Information System (INIS)

    Rittenberg, R.B.

    1998-03-01

    The US Department of Energy (DOE) has responsibilities under the Low-Level Radioactive Waste Policy Amendments Act of 1985 to assist states and compacts in their siting and licensing efforts for low-level radioactive waste disposal facilities. The National Low-Level Waste Management Program (NLLWMP) is the element of the DOE that performs the key support activities under the Act. The NLLWMP's activities are driven by the needs of the states and compacts as they prepare to manage their low-level waste under the Act. Other work is added during the fiscal year as necessary to accommodate new requests brought on by status changes in states' and compacts' siting and licensing efforts. This report summarizes the activities and accomplishments of the NLLWMP during FY 1997

  10. Characterization of the low-lying 0$^{+}$ and 2$^{+}$ states of $^{68}$ Ni

    CERN Multimedia

    Recently, a number of low-lying low-spin states have been firmly identified in $^{68}$Ni; the position of the first excited state (which is a 0$^{+}$ state), the spin and parity of the second excited 0$^{+}$ state and the spin and parity of the second and third 2$^+$ states have been fixed. The identification of these three pairs of 0$^+$ and 2$^+$ states in $^{68}$Ni (Z=28 and N=40) forms ideal tests to validate shell-model calculations and the effective interactions developed for the nickel region but also hints to triple shape coexistence including even strongly deformed structures. The aim of this proposal is to collect detailed spectroscopic data of the low-spin states of $^{68}$Ni (Z=28, N=40) in order to characterize these triple pairs of 0$^+$ and 2$^+$ states. $\\gamma$-branching ratios of the 0$^+$ and 2$^+$ states and the E0 transition strengths as well as the E2 transition rate of the 0$_3^+$ will be obtained using the new ISOLDE decay station that is constructed from an efficient array of germaniu...

  11. TiO2 nanotubes supported NiW hydrodesulphurization catalysts: Characterization and activity

    International Nuclear Information System (INIS)

    Palcheva, R.; Dimitrov, L.; Tyuliev, G.; Spojakina, A.; Jiratova, K.

    2013-01-01

    Highlights: ► NiW catalysts supported on TiO 2 nanotubes, titania and alumina. ► The best results are obtained with NiW/TiO 2 nanotubes in hydrodesulfurization (HDS) of thiophene. ► Active phase is Ni-WO x S y . ► Electronic promotion of W by Ti. - Abstract: High surface area TiO 2 nanotubes (Ti-NT) synthesized by alkali hydrothermal method were used as a support for NiW hydrodesulphurization catalyst. Nickel salt of 12-tungstophosphoric acid – Ni 3/2 PW 12 O 40 was applied as oxide precursor of the active components. The catalyst was characterized by S BET , XRD, UV–vis DRS, Raman spectroscopy, XPS, TPR and HRTEM. The results obtained were compared with those for the NiW catalysts prepared over high surface area titania and alumina supports. A polytungstate phase evidenced by Raman spectroscopy was observed indicating the destruction of the initial heteropolyanion. The catalytic experiments revealed two times higher thiophene conversion on NiW catalyst supported on Ti-NT than those of catalysts supported on alumina and titania. Increased HDS activity of the NiW catalyst supported on Ti-NT could be related to a higher amount of W oxysulfide entities interacting with Ni sulfide particles as consequence of the electronic effects of the Ti-NT observed with XPS analysis.

  12. Understanding low levels of physical activity in people with intellectual disabilities : A systematic review to identify barriers and facilitators

    NARCIS (Netherlands)

    Bossink, Leontien; van der Putten, Annette; Vlaskamp, Carla

    2017-01-01

    Background: People with intellectual disabilities (ID) undertake extremely low levels of physical activity. Aims: To enhance understanding concerning low levels of physical activity in people with ID, this study has three aims: (1) to identify barriers to and facilitators of physical activity in

  13. Synchrotron radiation-based 61Ni Mössbauer spectroscopic study of Li(Ni1/3Mn1/3Co1/3)O2 cathode materials of lithium ion rechargeable battery

    Science.gov (United States)

    Segi, Takashi; Masuda, Ryo; Kobayashi, Yasuhiro; Tsubota, Takayuki; Yoda, Yoshitaka; Seto, Makoto

    2016-12-01

    Layered rocksalt type oxides, such as Li(Ni1/3Mn1/3Co1/3)O2, are widely used as the cathode active materials of lithium-ion rechargeable batteries. Because the nickel ions are associated with the role of the charge compensation at discharge and charge, the 61Ni Mössbauer measurements at 6 K using synchrotron radiation were performed to reveal the role of Ni. The Ni ions of the active materials play two roles for the redox process between the charge and discharge states of lithium-ion batteries. Half of the total Ni ions change to the low-spin Ni3+ with Jahn-Teller distortion from the Ni2+ ions of the discharge state. The remainder exhibit low-spin state divalent Ni ions.

  14. Technical baseline description of high-level waste and low-activity waste feed mobilization and delivery

    International Nuclear Information System (INIS)

    Papp, I.G.

    1997-01-01

    This document is a compilation of information related to the high-level waste (HLW) and low-activity waste (LAW) feed staging, mobilization, and transfer/delivery issues. Information relevant to current Tank Waste Remediation System (TWRS) inventories and activities designed to feed the Phase I Privatization effort at the Hanford Site is included. Discussions on the higher level Phase II activities are offered for a perspective on the interfaces

  15. Activation behaviour of ZrCrNi mechanically milled with nickel

    International Nuclear Information System (INIS)

    Jung, C. B.; Ho Kim, J.; Sub Lee, K.

    1998-01-01

    AB 2 type Laves phase alloys have some promising properties as a negative electrode in rechargeable Ni/MH batteries because of high electrochemical capacity and good cyclic life. However, they have the disadvantage of requiring many charge-discharge cycles for activation. In this study, the mechanical milling with nickel has been introduced to modify the electrochemical behaviour of the ZrCrNi alloy. A composite-like structure (ZrCrNi+nickel) and nanocrystalline ZrCrNi were obtained through the mechanical milling and the hydrogenation behaviour of the electrode was greatly improved. (orig.)

  16. Heterobimetallic [NiFe] Complexes Containing Mixed CO/CN- Ligands: Analogs of the Active Site of the [NiFe] Hydrogenases.

    Science.gov (United States)

    Perotto, Carlo U; Sodipo, Charlene L; Jones, Graham J; Tidey, Jeremiah P; Blake, Alexander J; Lewis, William; Davies, E Stephen; McMaster, Jonathan; Schröder, Martin

    2018-03-05

    The development of synthetic analogs of the active sites of [NiFe] hydrogenases remains challenging, and, in spite of the number of complexes featuring a [NiFe] center, those featuring CO and CN - ligands at the Fe center are under-represented. We report herein the synthesis of three bimetallic [NiFe] complexes [Ni( N 2 S 2 )Fe(CO) 2 (CN) 2 ], [Ni( S 4 )Fe(CO) 2 (CN) 2 ], and [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] that each contain a Ni center that bridges through two thiolato S donors to a {Fe(CO) 2 (CN) 2 } unit. X-ray crystallographic studies on [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ], supported by DFT calculations, are consistent with a solid-state structure containing distinct molecules in the singlet ( S = 0) and triplet ( S = 1) states. Each cluster exhibits irreversible reduction processes between -1.45 and -1.67 V vs Fc + /Fc and [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] possesses a reversible oxidation process at 0.17 V vs Fc + /Fc. Spectroelectrochemical infrared (IR) and electron paramagnetic resonance (EPR) studies, supported by density functional theory (DFT) calculations, are consistent with a Ni III Fe II formulation for [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] + . The singly occupied molecular orbital (SOMO) in [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] + is based on Ni 3d z 2 and 3p S with the S contributions deriving principally from the apical S-donor. The nature of the SOMO corresponds to that proposed for the Ni-C state of the [NiFe] hydrogenases for which a Ni III Fe II formulation has also been proposed. A comparison of the experimental structures, and the electrochemical and spectroscopic properties of [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] and its [Ni( N 2 S 3 )] precursor, together with calculations on the oxidized [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] + and [Ni( N 2 S 3 )] + forms suggests that the binding of the {Fe(CO)(CN) 2 } unit to the {Ni(CysS) 4 } center at the active site of the [NiFe] hydrogenases suppresses thiolate-based oxidative chemistry involving the bridging thiolate S donors

  17. Identification of 100Sn and other proton drip-line nuclei in the reaction 112Sn + natNi at 63 MeV/nucleon

    International Nuclear Information System (INIS)

    Lewitowicz, M.; Anne, R.; Auger, G.; Bazin, D.; Corre, J.M.; Borcea, C.; Borrel, V.; Fomichov, A.; Grzywacz, R.; and others.

    1996-01-01

    The doubly-magic nucleus 100 Sn and six new neutron-deficient nuclei in the A∼100 region were identified in the reaction 112 Sn + nat Ni at 63 MeV/nucleon. The experiment was carried out using the high acceptance device SISSI and the Alpha and LISE3 spectrometers at GANIL. The identification of the reaction products (A, Z and Q) was made using the measurements of time-of-flight, energy-loss and kinetic energy. (author)

  18. Facile synthesis of ferromagnetic Ni doped CeO{sub 2} nanoparticles with enhanced anticancer activity

    Energy Technology Data Exchange (ETDEWEB)

    Abbas, Fazal; Jan, Tariq [Laboratory of Nanoscience and Technology, Department of Physics, International Islamic University Islamabad (Pakistan); Iqbal, Javed, E-mail: javed.saggu@iiu.edu.pk [Laboratory of Nanoscience and Technology, Department of Physics, International Islamic University Islamabad (Pakistan); Ahmad, Ishaq [Experimental Physics Labs, National Center for Physics, Islamabad (Pakistan); Naqvi, M. Sajjad H. [Department of Biochemistry, University of Karachi, Karachi (Pakistan); Malik, Maaza [UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West 7129, PO Box 722, Somerset West, Western Cape Province (South Africa)

    2015-12-01

    Highlights: • The synthesized undoped and Ni doped CeO{sub 2} nanoparticles exhibited RTFM. • Oxygen vacancies and magnetic ions both were believed to be responsible for RTFM. • The prepared nanoparticles exhibited selective cytotoxicity. • Ni doping enhanced the anticancer activity of CeO{sub 2} nanoparticles. • Differential ROS generation was observed to control their cytotoxicity. - Abstract: Ni{sub x}Ce{sub 1−x}O{sub 2} (where x = 0, 0.01, 0.03, 0.05 and 0.07) nanoparticles were synthesized by soft chemical method and were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman, UV–vis absorption spectroscopy and vibrating sample magnetometer (VSM). XRD and Raman results indicated the formation of single phase cubic fluorite structure for the synthesized nanoparticles. Ni dopant induced excessive structural changes such as decrease in crystallite size as well as lattice constants and enhancement in oxygen vacancies in CeO{sub 2} crystal structure. These structural variations significantly influenced the optical and magnetic properties of CeO{sub 2} nanoparticles. The synthesized Ni{sub x}Ce{sub 1−x}O{sub 2} nanoparticles exhibited room temperature ferromagnetic behavior. Ni doping induced effects on the cytotoxicity of CeO{sub 2} nanoparticles were examined against HEK-293 healthy cell line and SH-SY5Y neuroblastoma cancer cell line. The prepared Ni{sub x}Ce{sub 1−x}O{sub 2} nanoparticles demonstrated differential cytotoxicity. Furthermore, anticancer activity of CeO{sub 2} nanoparticles observed to be significantly enhanced with Ni doping which was found to be strongly correlated with the level of reactive oxygen species (ROS) production. The prepared ferromagnetic Ni{sub x}Ce{sub 1−x}O{sub 2} nanoparticles with differential cytotoxic nature may be potential for future targeted cancer therapy.

  19. Impaired bacterial attachment to light activated Ni-Ti alloy

    International Nuclear Information System (INIS)

    Chrzanowski, Wojciech; Valappil, Sabeel P.; Dunnill, Charles W.; Abou Neel, Ensanya A.; Lee, Kevin; Parkin, Ivan P.; Wilson, Michael; Armitage, David A.; Knowles, Jonathan C.

    2010-01-01

    Ni-Ti alloy due to its unique mechanical properties, is used for many types of implants. Failure of these implants can be attributed to many different factors; however infections are a common problem. In this paper, the attachment of the bacteria, Staphylococcus aureus, to the Ni-Ti surface modified by a range of processes with and without of light activation (used to elicit antimicrobial properties of materials) was assessed and related to different surface characteristics. Before the light activation the number of bacterial colony forming units was the greatest for the samples thermally oxidised at 600 deg. C. This sample and the spark oxidised samples showed the highest photocatalytic activity but only the thermally oxidised samples at 600 deg. C showed a significant drop of S. aureus attachment. The findings in this study indicate that light activation and treating samples at 600 deg. C is a promising method for Ni-Ti implant applications with inherent antimicrobial properties. Light activation was shown to be an effective way to trigger photocatalytic reactions on samples covered with relatively thick titanium dioxide via accumulation of photons in the surface and a possible increase in defects which may result in free oxygen. Moreover, light activation caused an increase in the total surface energy.

  20. The role of promoters for Ni catalysts in low temperature (membrane) steam methane reforming

    NARCIS (Netherlands)

    Ligthart, D.A.J.M.; Pieterse, J.A.Z.; Hensen, E.J.M.

    2011-01-01

    In the search for active and stable Ni-based catalysts for steam methane reforming in membrane reactors, the effect of three different promoters La, B and Rh was compared. Promoted and unpromoted Ni catalysts were characterized by TEM, TPR and X-ray absorption spectroscopy. The average Ni particle

  1. Water-Gas Shift and CO Methanation Reactions over Ni-CeO2(111) Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    S Senanayake; J Evans; S Agnoli; L Barrio; T Chen; J Hrbek; J Rodriguez

    2011-12-31

    X-ray and ultraviolet photoelectron spectroscopies were used to study the interaction of Ni atoms with CeO{sub 2}(111) surfaces. Upon adsorption on CeO{sub 2}(111) at 300 K, nickel remains in a metallic state. Heating to elevated temperatures (500-800 K) leads to partial reduction of the ceria substrate with the formation of Ni{sup 2+} species that exists as NiO and/or Ce{sub 1-x}Ni{sub x}O{sub 2-y}. Interactions of nickel with the oxide substrate significantly reduce the density of occupied Ni 3d states near the Fermi level. The results of core-level photoemission and near-edge X-ray absorption fine structure point to weakly bound CO species on CeO{sub 2}(111) which are clearly distinguishable from the formation of chemisorbed carbonates. In the presence of Ni, a stronger interaction is observed with chemisorption of CO on the admetal. When the Ni is in contact with Ce{sup +3} cations, CO dissociates on the surface at 300 K forming NiC{sub x} compounds that may be involved in the formation of CH{sub 4} at higher temperatures. At medium and large Ni coverages (>0.3 ML), the Ni/CeO{sub 2}(111) surfaces are able to catalyze the production of methane from CO and H{sub 2}, with an activity slightly higher than that of Ni(100) or Ni(111). On the other hand, at small coverages of Ni (<0.3 ML), the Ni/CeO{sub 2}(111) surfaces exhibit a very low activity for CO methanation but are very good catalysts for the water-gas shift reaction.

  2. Hydrogen production using thermocatalytic decomposition of methane on Ni30/activated carbon and Ni30/carbon black.

    Science.gov (United States)

    Srilatha, K; Viditha, V; Srinivasulu, D; Ramakrishna, S U B; Himabindu, V

    2016-05-01

    Hydrogen is an energy carrier of the future need. It could be produced from different sources and used for power generation or as a transport fuel which mainly in association with fuel cells. The primary challenge for hydrogen production is reducing the cost of production technologies to make the resulting hydrogen cost competitive with conventional fuels. Thermocatalytic decomposition (TCD) of methane is one of the most advantageous processes, which will meet the future demand, hence an attractive route for COx free environment. The present study deals with the production of hydrogen with 30 wt% of Ni impregnated in commercially available activated carbon and carbon black catalysts (samples coded as Ni30/AC and Ni30/CB, respectively). These combined catalysts were not attempted by previous studies. Pure form of hydrogen is produced at 850 °C and volume hourly space velocity (VHSV) of 1.62 L/h g on the activity of both the catalysts. The analysis (X-ray diffraction (XRD)) of the catalysts reveals moderately crystalline peaks of Ni, which might be responsible for the increase in catalytic life along with formation of carbon fibers. The activity of carbon black is sustainable for a longer time compared to that of activated carbon which has been confirmed by life time studies (850 °C and 54 sccm of methane).

  3. Properties of Ni^+ from microwave spectroscopy of n=9 Rydberg levels of Nickel

    Science.gov (United States)

    Woods, Shannon; Keele, Julie; Smith, Chris; Lundeen, Stephen

    2012-06-01

    The microwave/RESIS method was used to determine the relative positions of 15 of the n=9 Rydberg levels of Nickel with L >= 6. Because the ground state of the Ni^+ ion is a ^2D5/2 level, each Rydberg level (n,L) splits into six eigenstates whose relative positions are determined by long-range e-Ni^+ interactions present in addition to the dominant Coulomb interaction. A previous study with the optical RESIS method determined these positions with precision of +/- 30 MHz [1]. Using the microwave/RESIS method improves that precision by a factor of 300, and leads to much improved determinations of the Ni+ properties that control the long-range interactions. [4pt] [1] Julie A. Keele, Shannon L. Woods, M.E. Hanni, and S.R. Lundeen Phys. Rev. 81, 022506 (2010)

  4. Effects of surface treatments of MlNi 4.0Co 0.6Al 0.4 hydrogen storage alloy on the activation, charge/discharge cycle and degradation of Ni/MH batteries

    Science.gov (United States)

    Chen, Weixiang

    The effects of the surface treatment of the hydrogen storage alloy on the activation property and cycle life of nickel/metal-hydride (Ni/MH) batteries were investigated by means of the electrochemical impedance spectra. It was found that the oxide layer on the alloy surface affected its electrochemical properties and catalysis for the oxygen combination. Therefore, Ni/MH battery employed the untreated alloy as negative electrode material exhibited bad activation property, short cycle life and high internal pressure. Because of the improvement in the metal hydride electrode electrochemical characteristics and catalysis for oxygen recombination by the surface treatment of the alloy in 0.02 M KBH 4+6 M KOH or 6 M KOH solution, the battery used the treated alloy as negative exhibited good activation, long cycle life and low internal pressure. The composition and dissolution of the alloy surface were analyzed by an electron probe microanalysis (EPMA) and induced coupled plasma spectroscopy (ICP). It was found that the Ni-rich surface layer was an important factor to improve the activation and cycle life of battery.

  5. Low-Temperature Catalytic Performance of Ni-Cu/Al2O3 Catalysts for Gasoline Reforming to Produce Hydrogen Applied in Spark Ignition Engines

    Directory of Open Access Journals (Sweden)

    Le Anh Tuan

    2016-03-01

    Full Text Available The performance of Ni-Cu/Al2O3 catalysts for steam reforming (SR of gasoline to produce a hydrogen-rich gas mixture applied in a spark ignition (SI engine was investigated at relatively low temperature. The structural and morphological features and catalysis activity were observed by X-ray diffractometry (XRD, scanning electron microscopy (SEM, and temperature programmed reduction (TPR. The results showed that the addition of copper improved the dispersion of nickel and therefore facilitated the reduction of Ni at low temperature. The highest hydrogen selectivity of 70.6% is observed over the Ni-Cu/Al2O3 catalysts at a steam/carbon ratio of 0.9. With Cu promotion, a gasoline conversion of 42.6% can be achieved at 550 °C, while with both Mo and Ce promotion, the gasoline conversions were 31.7% and 28.3%, respectively, higher than with the conventional Ni catalyst. On the other hand, initial durability testing showed that the conversion of gasoline over Ni-Cu/Al2O3 catalysts slightly decreased after 30 h reaction time.

  6. Preparation and Characterization of Cu and Ni on Alumina Supports and Their Use in the Synthesis of Low-Temperature Metal-Phthalocyanine Using a Parallel-Plate Reactor

    Directory of Open Access Journals (Sweden)

    Carlos J. Lucio-Ortiz

    2013-09-01

    Full Text Available Ni- and Cu/alumina powders were prepared and characterized by X-ray diffraction (XRD, scanning electronic microscope (SEM, and N2 physisorption isotherms were also determined. The Ni/Al2O3 sample reveled agglomerated (1 μm of nanoparticles of Ni (30–80 nm however, NiO particles were also identified, probably for the low temperature during the H2 reduction treatment (350 °C, the Cu/Al2O3 sample presented agglomerates (1–1.5 μm of nanoparticles (70–150 nm, but only of pure copper. Both surface morphologies were different, but resulted in mesoporous material, with a higher specificity for the Ni sample. The surfaces were used in a new proposal for producing copper and nickel phthalocyanines using a parallel-plate reactor. Phthalonitrile was used and metallic particles were deposited on alumina in ethanol solution with CH3ONa at low temperatures; ≤60 °C. The mass-transfer was evaluated in reaction testing with a recent three-resistance model. The kinetics were studied with a Langmuir-Hinshelwood model. The activation energy and Thiele modulus revealed a slow surface reaction. The nickel sample was the most active, influenced by the NiO morphology and phthalonitrile adsorption.

  7. Structural and room temperature ferromagnetic properties of Ni doped ZnO nanoparticles via low-temperature hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Kun; Liu, Changzhen, E-mail: liuchangzhen94@163.com; Chen, Rui; Fang, Xiaoxiang; Wu, Xiuling; Liu, Jie

    2016-12-01

    A series of Zn{sub 1−x}Ni{sub x}O (x=0, 1%, 3%, 5%) nanoparticles have been synthesized via a low-temperature hydrothermal method. Influence of Ni doping concentration on the structure, morphology, optical properties and magnetism of the samples was investigated by means of X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, UV–vis spectrophotometer and vibrating sample magnetometer instruments. The results show that the undoped and doped ZnO nanoparticles are both hexagonal wurtzite structures. The surface analysis was performed using X-ray photoelectron spectroscopic studies. The images of SEM reveal that the structure of pure ZnO and Ni doped samples are nanoparticles which intended to form flakes with thickness of few nanometers, being overlain with each one to develop the network with some pores and voids. Based on the ultraviolet–visible (UV–vis) spectroscopy analysis, it indicates that the band gap energy decreases with the increasing concentration of Ni. Furthermore, The Ni doped ZnO samples didn't exhibit higher ultraviolet-light-driven photocatalytic activity compared to the undoped ZnO sample. Vibrating sample magnetometer was used for the magnetic property investigations, and the result indicates that room temperature ferromagnetism property of 3% Ni doped sample is attributed to oxygen vacancy and interaction between doped ions.

  8. Thermally activated low temperature creep and primary water stress corrosion cracking of NiCrFe alloys

    International Nuclear Information System (INIS)

    Hall, M.M. Jr.

    1993-01-01

    A phenomenological SCC-CGR model is developed based on an apriori assumption that the SCC-CGR is controlled by low temperature creep (LTC). This mode of low temperature time dependent deformation occurs at stress levels above the athermal flow stress by a dislocation glide mechanism that is thermally activated and may be environmentally assisted. The SCC-CGR model equations developed contain thermal activation parameters descriptive of the dislocation creep mechanism. Thermal activation parameters are obtained by fitting the CGR model to SCC-CGR data obtained on Alloy 600 and Alloy X-750. These SCC-CGR activation parameters are compared to LTC activation parameters obtained from stress relaxation tests. When the high concentration of hydrogen at the tip of an SCC crack is considered, the SCC-CGR activation energies and rate sensitivities are shown to be quantitatively consistent with hydrogen reducing the activation energy and increasing the strain rate sensitivity in LTC stress relaxation tests. Stress dependence of SCC-CGR activation energy consistent with that found for the LTC activation energy. Comparisons between temperature dependence of the SCC-CGR stress sensitivity and LTC stress sensitivity provide a basis for speculation on effects of hydrogen and solute carbon on SCC crack growth rates

  9. Structural high-temperature and (βNiAl+γ)-alloys based on Ni-Al-Co-Me systems with an improved low-temperature ductility

    International Nuclear Information System (INIS)

    Povarova, K.B.; Kazanskaya, N.K.; Drozdov, A.A.; Lomberg, B.S.; Gerasimov, V.V.

    2001-01-01

    The βNiAl-based alloys (B2) have lower density higher resistance to oxidation, and higher melting temperature relative to those of Ni-superalloys or γ'Ni 3 Al-base alloys. An improved low-temperature ductility of advanced Ni-AI-Co-M β+γ alloys(El=9-16 % at 293-1173 K is achieved due to the formation γ-Ni solid solution intergranular interlayers of eutectic origin. Secondary γ and/or γ' precipitates form in the grains of the supersaturated β-solid solution upon heat treatment at 1473-1573 K and 1073-1173 K. The limiting contents of alloying elements (Ti, Hf, Nb, Ta, Cr, Mo) for the (β+γ) alloys Ni - (19-29) % AI - (22-35) % Co, are determined which allowed to avoid the formation of primary γ'-phase (decrease solidus temperature ≤1643 K) and hard phases of the types σ, η and δ (decrease ductility). Alloying affects the morphology of the secondary γ and γ' precipitates: globular equiaxed precipitates are formed in the alloys containing Cr, Mo, and needle precipitates are formed in alloys alloys containing γ'-forming elements Nb, Ta and, especially, Ti and Hf. After directional solidification, (β+γ')-alloys have directed columnar special structure with a low extension of transverse grain boundaries. This microstructure allows one to increase UTS, by a factor 1,5-2 and long-term strength (time to rupture increase by a factor of 5-10 at 1173 K). (author)

  10. Ni-Based Catalysts for Low Temperature Methane Steam Reforming: Recent Results on Ni-Au and Comparison with Other Bi-Metallic Systems

    Directory of Open Access Journals (Sweden)

    Anna M. Venezia

    2013-06-01

    Full Text Available Steam reforming of light hydrocarbons provides a promising method for hydrogen production. Ni-based catalysts are so far the best and the most commonly used catalysts for steam reforming because of their acceptably high activity and significantly lower cost in comparison with alternative precious metal-based catalysts. However, nickel catalysts are susceptible to deactivation from the deposition of carbon, even when operating at steam-to-carbon ratios predicted to be thermodynamically outside of the carbon-forming regime. Reactivity and deactivation by carbon formation can be tuned by modifying Ni surfaces with a second metal, such as Au through alloy formation. In the present review, we summarize the very recent progress in the design, synthesis, and characterization of supported bimetallic Ni-based catalysts for steam reforming. The progress in the modification of Ni with noble metals (such as Au and Ag is discussed in terms of preparation, characterization and pretreatment methods. Moreover, the comparison with the effects of other metals (such as Sn, Cu, Co, Mo, Fe, Gd and B is addressed. The differences of catalytic activity, thermal stability and carbon species between bimetallic and monometallic Ni-based catalysts are also briefly shown.

  11. Probing the semi-magicity of $^{68}$Ni via the $^{66}$Ni(t,p)$^{68}$Ni two-neutron transfer reaction in inverse kinematics

    CERN Document Server

    AUTHOR|(CDS)2079390; Van Duppen, Piet

    The region around the nucleus $^{68}$Ni, with a shell closure for its protons at Z=28 and a harmonic oscillator shell gap for its neutrons at N=40, has drawn considerable interest over the past decades. $^{68}$Ni has properties that are typical for a doubly-magic nucleus, such as a high excitation energy and low B($E2:2^{+} \\rightarrow 0^{+}$) transition probability for the first excited 2$^{+}$ level and a 0$^{+}$ level as the first excited state. However, it has been suggested that the magic properties of $^{68}$Ni arise due to the fact that the N=40 separates the negative parity $pf$-shell from the positive parity 1$g_{9/2}$ orbital, and indeed, recent mass measurements have not revealed a clear N = 40 energy gap. Despite all additional information that was acquired over the last decade the specific role of the N=40 is not yet understood and a new experimental approach to study $^{68}$Ni was proposed. Namely, a two-neutron transfer reaction on $^{66}$Ni to characterize and disentangle the structure of the ...

  12. Nonenzymatic Glucose Sensor Based on In Situ Reduction of Ni/NiO-Graphene Nanocomposite

    Directory of Open Access Journals (Sweden)

    Xiaohui Zhang

    2016-10-01

    Full Text Available Ni/NiO nanoflower modified reduced graphene oxide (rGO nanocomposite (Ni/NiO-rGO was introduced to screen printed electrode (SPE for the construction of a nonenzymatic electrochemical glucose biosensor. The Ni/NiO-rGO nanocomposite was synthesized by an in situ reduction process. Graphene oxide (GO hybrid Nafion sheets first chemical adsorbed Ni ions and assembled on the SPE. Subsequently, GO and Ni ions were reduced by hydrazine hydrate. The electrochemical properties of such a Ni/NiO-rGO modified SPE were carefully investigated. It showed a high activity for electrocatalytic oxidation of glucose in alkaline medium. The proposed nonenzymatic sensor can be utilized for quantification of glucose with a wide linear range from 29.9 μM to 6.44 mM (R = 0.9937 with a low detection limit of 1.8 μM (S/N = 3 and a high sensitivity of 1997 μA/mM∙cm−2. It also exhibited good reproducibility as well as high selectivity.

  13. Improving carbon tolerance of Ni-YSZ catalytic porous membrane by palladium addition for low temperature steam methane reforming

    Science.gov (United States)

    Lee, Sang Moon; Won, Jong Min; Kim, Geo Jong; Lee, Seung Hyun; Kim, Sung Su; Hong, Sung Chang

    2017-10-01

    Palladium was added on the Ni-YSZ catalytic porous membrane by wet impregnation and electroless plating methods. Its surface morphology characteristics and carbon deposition properties for the low temperature steam methane reforming were investigated. The addition of palladium could obviously be enhanced the catalytic activity as well as carbon tolerance of the Ni-YSZ porous membrane. The porous membranes were evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), H2 temperature-programmed reduction (H2-TPR), CH4 temperature-programmed reduction (CH4-TPR), and O2 temperature-programmed oxidation (O2-TPO). It was found that the Pd-Ni-YSZ catalytic porous membrane showed the superior stability as well as the deposition of carbon on the surface during carbon dissociation adsorption at 650 °C was also suppressed.

  14. Clearance of very low level radioactive waste in spanish nuclear power plants

    International Nuclear Information System (INIS)

    Alvarez Mir, F.

    2001-01-01

    According to present Spanish legislation a radioactive waste is defined as any material or waste product, without any possible planned use, that contains or is contaminated with radionuclides in concentrations or activity levels higher than those established by the Regulatory Authorities. Legally, this situation allows to develop a conventional management of very low level radioactive waste, by checking the negligibility of their radiological impact, and thus obtaining the corresponding Authorization to treat them as conventional waste. This presentation describes the clearance project of contaminated oils from spanish nuclear power plants. The on-site management includes: -) preliminary settling, centrifugation and filtration; -) oil purification; and -) radiological characterization. The off-site management includes the following operations: -) transportation to the facility where treatment is developed (dilution); -) temporary storage (decay); -) transportation to the place where final management is carried out; -) oil burning (dilution); and management of ashes and other combustion products. An annual amount of 70 m 3 /year (63 MBq) of very low contaminated oil with a specific concentration of 1 Bq/g could be disposed off. (A.C.)

  15. Study and development of NiAl intermetallic coating on hypo-eutectoid steel using highly activated composite granules of the Ni-Al system

    Energy Technology Data Exchange (ETDEWEB)

    Shahzad, Aamir; Zadorozhnyy, Vladislav Yu.; Pavlov, Mikhail D.; Semenov, Dmitri V.; Kaloshkin, Sergey D. [National Univ. of Science and Technology (MISIS), Moscow (Russian Federation)

    2018-01-15

    NiAl intermetallic coating thickness of about 50 μm was fabricated on hypo-eutectoid steel by mechanical alloying using pre-activated Ni-Al composite granules as coating material. First, Ni and Al powders were mixed with the composition of Ni-50 at.% Al and mechanically activated in a planetary ball mill, until the composite granules of this powder mixture, having maximum activity (9 cm sec{sup -1}), were formed after 120 min of milling at 200 rpm. The composite granules were then taken out from the planetary ball mill just before the critical time, i. e. the time at which these granules synthesize and convert to an intermetallic NiAl compound. The highly activated composite granules of Ni-Al were then put into the vial of a vibratory ball mill with the substrate on top of the chamber. After mechanical alloying for 60 min in the vibratory ball mill, the composite granules were synthesized fully and heat was produced during the synthesis which helped producing a thick and strong adhesive coating of NiAl intermetallic on the steel substrate. The main advantage of this technique is that not only is time saved but also there is no need for any post mechanical alloying process such as annealing or laser treatment etc. to get homogeneous, strongly bonded intermetallic coatings. X-ray diffraction analysis clearly indicates the formation of NiAl phase. Micro-hardness of the coating and substrate was also measured. The cross-sectional microstructure of the composite granules and the final coating were studied by scanning electron microscopy.

  16. National Low-Level Waste Management Program final summary report of key activities and accomplishments for fiscal year 1996

    International Nuclear Information System (INIS)

    Garcia, R.S.

    1996-12-01

    To assist the Department of Energy (DOE) in fulfilling its responsibilities under the Low-Level Radioactive Waste Policy Amendments Act of 1985, the National Low-Level Waste Management Program (NLLWMP) outlines the key activities tat the NLLWMP will accomplish in the following fiscal year. Additional activities are added during the fiscal year as necessary to accomplish programmatic goals. This report summarizes the activities and accomplishments of the NLLWMP during Fiscal Year 1996

  17. National Low-Level Waste Management Program final summary report of key activities and accomplishments for fiscal year 1995

    International Nuclear Information System (INIS)

    Forman, S.

    1995-12-01

    To assist the Department of Energy (DOE) in fulfilling its responsibilities under the Low-Level Radioactive Waste Policy Amendments Act of 1985, the National Low-Level Waste Management Program (NLLWMP) outlines the key activities that the NLLWMP will accomplish in the following fiscal year. Additional activities are added during the fiscal year as necessary to accomplish programmatic goals. This report summarizes the activities and accomplishments of the NLLWMP during fiscal year 1995

  18. Sp1/Sp3 and DNA-methylation contribute to basal transcriptional activation of human podoplanin in MG63 versus Saos-2 osteoblastic cells

    Directory of Open Access Journals (Sweden)

    Puri Christina

    2007-03-01

    Full Text Available Abstract Background Podoplanin is a membrane mucin that, among a series of tissues, is expressed on late osteoblasts and osteocytes. Since recent findings have focussed on podoplanin's potential role as a tumour progression factor, we aimed at identifying regulatory elements conferring PDPN promoter activity. Here, we characterized the molecular mechanism controlling basal PDPN transcription in human osteoblast-like MG63 versus Saos-2 cells. Results We cloned and sequenced 2056 nucleotides from the 5'-flanking region of the PDPN gene and a computational search revealed that the TATA and CAAT box-lacking promoter possesses features of a growth-related gene, such as a GC-rich 5' region and the presence of multiple putative Sp1, AP-4 and NF-1 sites. Reporter gene assays demonstrated a functional promoter in MG63 cells exhibiting 30-fold more activity than in Saos-2 cells. In vitro DNase I footprinting revealed eight protected regions flanked by DNaseI hypersensitive sites within the region bp -728 to -39 present in MG63, but not in Saos-2 cells. Among these regions, mutation and supershift electrophoretic mobility shift assays (EMSA identified four Sp1/Sp3 binding sites and two binding sites for yet unknown transcription factors. Deletion studies demonstrated the functional importance of two Sp1/Sp3 sites for PDPN promoter activity. Overexpression of Sp1 and Sp3 independently increased the stimulatory effect of the promoter and podoplanin mRNA levels in MG63 and Saos-2 cells. In SL2 cells, Sp3 functioned as a repressor, while Sp1 and Sp3 acted positively synergistic. Weak PDPN promoter activity of Saos-2 cells correlated with low Sp1/Sp3 nuclear levels, which was confirmed by Sp1/Sp3 chromatin immunoprecipitations in vivo. Moreover, methylation-sensitive Southern blot analyses and bisulfite sequencing detected strong methylation of CpG sites upstream of bp -464 in MG63 cells, but hypomethylation of these sites in Saos-2 cells. Concomitantly

  19. Electrochemical behavior of low phosphorus electroless Ni-P-Si3N4 composite coatings

    International Nuclear Information System (INIS)

    Balaraju, J.N.; Ezhil Selvi, V.; Rajam, K.S.

    2010-01-01

    In the present investigation the electroless Ni-P-Si 3 N 4 composite coatings were prepared by using a low phosphorus bath containing submicron size silicon nitride particles. Plain Ni-P deposits were also prepared for comparison. The phosphorus contents present in electroless plain Ni-P and Ni-P-Si 3 N 4 coatings are 3.7 and 3.4 wt.%, respectively. Scanning electron microscope (SEM) images obtained for composite coatings (cross-sections) showed that the second phase particles are uniformly distributed throughout the thickness of the deposits. It was found that nodularity increased with particle codeposition in Ni-P matrix. To find out the electrochemical behavior of plain Ni-P and composite coatings, potentiodynamic polarization and electrochemical impedance (EIS) studies were carried out in 3.5 wt.% sodium chloride solution in non-deaerated condition. Second phase particle incorporation in Ni-P matrix indicated a marginal decrease in corrosion current density compared to the plain Ni-P deposits. This was further confirmed by EIS studies and SEM analysis of the corroded samples.

  20. Characterization of thin Zn-Ni alloy coatings electrodeposited on low carbon steel

    International Nuclear Information System (INIS)

    El Hajjami, A.; Gigandet, M.P.; De Petris-Wery, M.; Catonne, J.C.; Duprat, J.J.; Thiery, L.; Raulin, F.; Pommier, N.; Starck, B.; Remy, P.

    2007-01-01

    The characteristics of initial layer formation in alkaline bath for Zn-Ni (12-15%) alloy electrodeposition on low carbon steel plates are detected in a nanometric thickness range by electron probe microanalysis (EPMA), with both bulk sample and thin film on substrate correction procedure, glow discharge optical emission spectroscopy (GDOES) and gracing incidence X-ray diffraction (GIXRD). The Zn-Ni coatings were elaborated using either intensiostatic or potentiostatic mode. A preferential deposition of Ni, in the initial thin layer, is detected by these analyses; according to EPMA and GDOES measurements, a layer rich in nickel at the interface substrate/deposit is observed (90 wt.% Ni) and approved by GIXRD; the thin layer of Ni formed in the first moments of electrolysis greatly inhibits the Zn deposition. The initial layer depends upon the relative ease of hydrogen and metal discharge and on the different substrate surfaces involved. The electrodeposition of zinc-nickel alloys in the first stage is a normal phenomenon of codeposition, whereby nickel - the more noble metal - is deposited preferentially

  1. Effects of Ni particle morphology on cell performance of Na/NiCl2 battery

    Science.gov (United States)

    Kim, Mangi; Ahn, Cheol-Woo; Hahn, Byung-Dong; Jung, Keeyoung; Park, Yoon-Cheol; Cho, Nam-ung; Lee, Heesoo; Choi, Joon-Hwan

    2017-11-01

    Electrochemical reaction of Ni particle, one of active cathode materials in the Na/NiCl2 battery, occurs on the particle surface. The NiCl2 layer formed on the Ni particle surface during charging can disconnect the electron conduction path through Ni particles because the NiCl2 layer has very low conductivity. The morphology and size of Ni particles, therefore, need to be controlled to obtain high charge capacity and excellent cyclic retention. Effects of the Ni particle size on the cell performance were investigated using spherical Ni particles with diameters of 0.5 μm, 6 μm, and 50 μm. The charge capacities of the cells with spherical Ni particles increased when the Ni particle size becomes smaller because of their higher surface area but their charge capacities were significantly decreased with increasing cyclic tests owing to the disconnection of electron conduction path. The inferior cyclic retention of charge capacity was improved using reticular Ni particles which maintained the reliable connection for the electron conduction in the Na/NiCl2 battery. The charge capacity of the cell with the reticular Ni particles was higher than the cell with the small-sized spherical Ni particles approximately by 26% at 30th cycle.

  2. Excitation function of alpha-particle-induced reactions on {sup nat}Ni from threshold to 44 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Uddin, M.S. [Atomic Energy Research Establishment, Tandem Accelerator Facilities, Institute of Nuclear Science and Technology, Savar, Dhaka (Bangladesh); Kim, K.S.; Nadeem, M.; Kim, G.N. [Kyungpook National University, Department of Physics, Buk-gu, Daegu (Korea, Republic of); Sudar, S. [Debrecen University, Institute of Experimental Physics, Debrecen (Hungary)

    2017-05-15

    Excitation functions of the {sup nat}Ni(α,x){sup 62,63,65}Zn, {sup nat}Ni(α,x){sup 56,57}Ni and {sup nat}Ni(α,x){sup 56,57,58m+g}Co reactions were measured from the respective thresholds to 44MeV using the stacked-foil activation technique. The tests for the beam characterization are described. The radioactivity was measured using HPGe γ-ray detectors. Theoretical calculations on α-particles-induced reactions on {sup nat}Ni were performed using the nuclear model code TALYS-1.8. A few results are new, the others strengthen the database. Our experimental data were compared with results of nuclear model calculations and described the reaction mechanism. (orig.)

  3. The microstructural stability and mechanical properties of two low activation martensitic steels

    International Nuclear Information System (INIS)

    Victoria, M.; Marmy, P.; Batawi, E.; Peters, J.; Briguet, C.; Rezai-Aria, F.; Gavillet, D.

    1996-01-01

    A desirable feature of future magnetically confined fusion reactors is the prospect of producing low level radioactive waste. In order to minimize the volume of radioactive material, in particular from the first wall and blanket structures, reduced long term activation alloys are being developed. Here, a low activation composition of a martensitic 9% Cr steel has been studied, based on the DIN (Deutsches Inst. fuer Normung) 1.4914 composition (MANET) but replacing Ni, Mo and Nb by the low activation elements W, V and Ta. Two casts were produced from high purity components, in which the effects of controlled additions of Mn (0.58 and 0.055 wt. %) and N (7 and 290 wt. ppm) were studied, so that the final compositions resulted in one cast with high Mn and low N (steel A) and the other with the opposite conditions (steel B). The two steels were evaluated in terms of structural stability and mechanical properties under tensile, fatigue and fracture toughness tests. It has been found that both alloys have a DBTT below room temperature, which in the case of the steel A is 70 K below that of MANET. Although the tensile strength is somewhat below that of the parent steel, both steels have longer fatigue life

  4. NiMo-sulfide supported on activated carbon to produce renewable diesel

    Directory of Open Access Journals (Sweden)

    Nancy Y Acelas

    2017-03-01

    Full Text Available Due to their weak polarity and large surface area, activated carbon supports have the potential to enhance the dispersion of metal-sulfides. It is expected that the absence of a strong metal-support interaction can result in the formation of a very active and stable Ni-Mo-S phase. In this study, catalysts with different amounts of nickel and molybdenum supported on a commercial activated carbon were prepared by a co-impregnation method and characterized by BET, XRF, and SEM techniques. The catalytic activity for hydroprocessing of Jatropha oil was evaluated in a batch reactor, and the composition of the liquid and gaseous products were determined. Results showed that gaseous products are mainly composed of high amounts of propane and small amounts of other light hydrocarbons (C1 to C5. Liquid hydrocarbon products consisted of a mixture containing mainly n-paraffins of C15-C18 and some oxygenated compounds. The catalysts with a mass fraction of 3 % Ni, 15 % Mo (Ni3Mo15/AC presented the highest selectivity toward C17-C18 hydrocarbons, with a product distribution similar to a commercial alumina-supported Ni-Mo-S catalyst.

  5. Low level waste disposal

    International Nuclear Information System (INIS)

    Barthoux, A.

    1985-01-01

    Final disposal of low level wastes has been carried out for 15 years on the shallow land disposal of the Manche in the north west of France. Final participant in the nuclear energy cycle, ANDRA has set up a new waste management system from the production center (organization of the waste collection) to the disposal site including the setting up of a transport network, the development of assessment, additional conditioning, interim storage, the management of the disposal center, records of the location and characteristics of the disposed wastes, site selection surveys for future disposals and a public information Department. 80 000 waste packages representing a volume of 20 000 m 3 are thus managed and disposed of each year on the shallow land disposal. The disposal of low level wastes is carried out according to their category and activity level: - in tumuli for very low level wastes, - in monoliths, a concrete structure, of the packaging does not provide enough protection against radioactivity [fr

  6. The effect of Fe2NiO4 and Fe4NiO4Zn magnetic nanoparticles on anaerobic digestion activity.

    Science.gov (United States)

    Chen, Jian Lin; Steele, Terry W J; Stuckey, David C

    2018-06-11

    Two types of magnetic nanoparticles (MNPs), i.e. Ni ferrite nanoparticles (Fe 2 NiO 4 ) and Ni Zn ferrite nanoparticles (Fe 4 NiO 4 Zn) containing the trace metals Ni and Fe, were added to the anaerobic digestion of synthetic municipal wastewater at concentrations between 1 and 100 mg Ni L -1 in order to compare their effects on biogas (methane) production and sludge activity. Using the production of methane over time as a measure, the assays revealed that anaerobic digestion was stimulated by the addition of 100 mg Ni L -1 in Fe 2 NiO 4 NPs, while it was inhibited by the addition of 1-100 mg Ni L -1 in Fe 4 NiO 4 Zn NPs. Especially at 100 mg Ni L -1 , Fe 4 NiO 4 Zn NPs resulted in a total inhibition of anaerobic digestion. The metabolic activity of the anaerobic sludge was tested using the resazurin reduction assay, and the assay clearly revealed the negative effect of Fe 4 NiO 4 Zn NPs and the positive effect of Fe 2 NiO 4 NPs. Re-feeding fresh synthetic medium reactivated the NPs added to the anaerobic sludge, except for the experiment with 100 mg Ni L -1 addition of Fe 4 NiO 4 Zn NPs. The findings in this present study indicate a possible new strategy for NPs design to enhance anaerobic digestion. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

  7. Summary report, low-level radioactive waste management activities in the states and compacts. Vol. 4. No. 1

    International Nuclear Information System (INIS)

    1996-01-01

    'Low-Level Radioactive Waste Management Activities in the States and Compacts' is a supplement to 'LLW Notes' and is distributed periodically by Afton Associates, Inc. to state, compact and federal officials that receive 'LLW Notes'. The Low-Level Radioactive Waste Forum (LLW Forum) is an association of state and compact representatives, appointed by governors and compact commissions, established to facilitate state and compact implementation of the Low- Level Radioactive Waste Policy Act of 1980 and the Low-Level Radioactive Waste Policy Amendments Act of 1985 and to promote the objectives of low-level radioactive waste regional compacts. The LLW Forum provides an opportunity for state and compact officials to share information with one another and to exchange views with officials of federal agencies and other interested parties

  8. Summary report. Low-level radioactive waste management activities in the states and compacts. Volume 4, No. 2

    International Nuclear Information System (INIS)

    1996-08-01

    'Low-Level Radioactive Waste Management Activities in the States and Compacts' is a supplement to 'LLW Notes' and is distributed periodically by Afton Associates, Inc. to state, compact and federal officials that receive 'LLW Notes'. The Low-Level Radioactive Waste Forum (LLW Forum) is an association of state and compact representatives, appointed by governors and compact commissions, established to facilitate state and compact implementation of the Low- Level Radioactive Waste Policy Act of 1980 and the Low-Level Radioactive Waste Policy Amendments Act of 1985 and to promote the objectives of low-level radioactive waste regional compacts. The LLW Forum provides an opportunity for state and compact officials to share information with one another and to exchange views with officials of federal agencies and other interested parties

  9. Calculation of Gibbs energy of Zr-Al-Ni, Zr-Al-Cu, Al-Ni-Cu and Zr-Al-Ni-Cu liquid alloys based on quasiregular solution model

    International Nuclear Information System (INIS)

    Li, H.Q.; Yang, Y.S.; Tong, W.H.; Wang, Z.Y.

    2007-01-01

    With the effects of electronic structure and atomic size being introduced, the mixing enthalpy as well as the Gibbs energy of the ternary Zr-Al-Cu, Ni-Al-Cu, Zr-Ni-Al and quaternary Zr-Al-Ni-Cu systems are calculated based on quasiregular solution model. The computed results agree well with the experimental data. The sequence of Gibbs energies of different systems is: G Zr-Al-Ni-Cu Zr-Al-Ni Zr-Al-Cu Cu-Al-Ni . To Zr-Al-Cu, Ni-Al-Cu and Zr-Ni-Al, the lowest Gibbs energy locates in the composition range of X Zr 0.39-0.61, X Al = 0.38-0.61; X Ni = 0.39-0.61, X Al = 0.38-0.60 and X Zr = 0.32-0.67, X Al = 0.32-0.66, respectively. And to the Zr-Ni-Al-Cu system with 66.67% Zr, the lowest Gibbs energy is obtained in the region of X Al = 0.63-0.80, X Ni = 0.14-0.24

  10. NiO-NF/MWCNT nanocomposite catalyst as a counter electrode for high performance dye-sensitized solar cells

    Science.gov (United States)

    Raissan Al-bahrani, Majid; Liu, Linfeng; Ahmad, Waqar; Tao, Jiayou; Tu, Fanfan; Cheng, Ze; Gao, Yihua

    2015-03-01

    In this paper, we fabricated nickel oxide nanofilament/multiwall carbon nanotubes (NiO-NF/MWCNT) nanocomposite by a simple hydrothermal synthesis method as a counter- electrode (CE) in a dye-sensitized solar cell (DSSC). Transmission electron microscopy, scanning electron microscopy images and X-ray diffraction analysis clearly indicated the formation of NiO-NF/MWCNT nanocomposite. The electro-chemical properties of NiO-NF/MWCNT CE are studied by cyclic voltammetry and electrochemical impedance spectroscopy. In particular, current-voltage measurements indicated superior power conversion efficiency (PCE) of 7.63% of the NiO-NF/MWCNT CE compared to 6.72% for the platinum (Pt). The superior photovoltaic performance and low cost of the NiO-NF/MWCNT nanocomposite can be potentially exploited as a new counter-electrode in DSSCs.

  11. [Correlation between knowledge about the consequences of obesity and physical activity levels among university students].

    Science.gov (United States)

    Ocampo-Mascaró, Javier; Silva-Salazar, Vera; da Costa-Bullón, A Daniel

    2015-12-02

    Obesity is a growing public health issue. One of the main strategies to prevent it is physical activity. To determine if a correlation exists between awareness of the consequences of obesity and physical activity level. A cross-sectional study performed on a group of 215 students was conducted in 2013 and 2014. Non-health related program students were selected by convenience sampling at a university in Lima, Peru. Their physical activity level was measured using the International Physical Activity Questionnaire (IPAQ), and knowledge about the consequences of obesity was assessed using the Obesity Risk Knowledge-10 scale (ORK-10). Each student was also asked to record the source where they obtained whatever information they knew about the topic. The median age of the participants was 20 (interquartile range of 4; 22-18), and 63% of the participants were female. According to the IPAQ, 53.9% of the participants recorded high levels of physical activity, 35.4% recorded moderate levels, and 10.7%, recorded low levels. While a low correlation between the ORK-10 score and the amount of METs/minute/week spent was found (rs=0.06), it was not significant (p=0.38). We found that people who were informed by the media or by healthcare personnel achieved higher scores on the ORK-10 scale than those who used other sources of information (p<0,05). There is a very low correlation between the knowledge about the consequences of obesity and a person’s physical activity level. A multidisciplinary approach that includes all determinants of physical activity is necessary in order to attain changes in people’s behavior.

  12. IGRIS for characterizing low-level radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Peters, C.W. [Nuclear Diagnostic Systems, Springfield, VA (United States); Swanson, P.J. [Concord Associates, Knoxville, TN (United States)

    1993-03-01

    A recently developed neutron diagnostic probe system has the potential to noninvasively characterize low-level radioactive waste in bulk soil samples, containers such as 55-gallon barrels, and in pipes, valves, etc. The probe interrogates the target with a low-intensity beam of 14-MeV neutrons produced from the deuterium-tritium reaction in a specially designed sealed-tube neutron-generator (STNG) that incorporates an alpha detector to detect the alpha particle associated with each neutron. These neutrons interact with the nuclei in the target to produce inelastic-, capture-, and decay-gamma rays that are detected by gamma-ray detectors. Time-of-flight methods are used to separate the inelastic-gamma rays from other gamma rays and to determine the origin of each inelastic-gamma ray in three dimensions through Inelastic-Gamma Ray Imaging and Spectroscopy (IGRIS). The capture-gamma ray spectrum is measured simultaneously with the IGRIS measurements. The decay-gamma ray spectrum is measured with the STNG turned off. Laboratory proof-of-concept measurements were used to design prototype systems for Bulk Soil Assay, Barrel Inspection, and Decontamination and Decommissioning and to predict their minimum detectable levels for heavy toxic metals (As, Hg, Cr, Zn, Pb, Ni, and Cd), uranium and transuranics, gamma-ray emitters, and elements such as chlorine, which is found in PCBs and other pollutants. These systems are expected to be complementary and synergistic with other technologies used to characterize low-level radioactive waste.

  13. Simulation of Ni-63 based nuclear micro battery using Monte Carlo modeling

    International Nuclear Information System (INIS)

    Kim, Tae Ho; Kim, Ji Hyun

    2013-01-01

    The radioisotope batteries have an energy density of 100-10000 times greater than chemical batteries. Also, Li ion battery has the fundamental problems such as short life time and requires recharge system. In addition to these things, the existing batteries are hard to operate at internal human body, national defense arms or space environment. Since the development of semiconductor process and materials technology, the micro device is much more integrated. It is expected that, based on new semiconductor technology, the conversion device efficiency of betavoltaic battery will be highly increased. Furthermore, the radioactivity from the beta particle cannot penetrate a skin of human body, so it is safer than Li battery which has the probability to explosion. In the other words, the interest for radioisotope battery is increased because it can be applicable to an artificial internal organ power source without recharge and replacement, micro sensor applied to arctic and special environment, small size military equipment and space industry. However, there is not enough data for beta particle fluence from radioisotope source using nuclear battery. Beta particle fluence directly influences on battery efficiency and it is seriously affected by radioisotope source thickness because of self-absorption effect. Therefore, in this article, we present a basic design of Ni-63 nuclear battery and simulation data of beta particle fluence with various thickness of radioisotope source and design of battery

  14. Preparation and Characterization of Surface Photocatalytic Activity with NiO/TiO₂ Nanocomposite Structure.

    Science.gov (United States)

    Chen, Jian-Zhi; Chen, Tai-Hong; Lai, Li-Wen; Li, Pei-Yu; Liu, Hua-Wen; Hong, Yi-You; Liu, Day-Shan

    2015-07-13

    This study achieved a nanocomposite structure of nickel oxide (NiO)/titanium dioxide (TiO₂) heterojunction on a TiO₂ film surface. The photocatalytic activity of this structure evaluated by decomposing methylene blue (MB) solution was strongly correlated to the conductive behavior of the NiO film. A p -type NiO film of high concentration in contact with the native n -type TiO₂ film, which resulted in a strong inner electrical field to effectively separate the photogenerated electron-hole pairs, exhibited a much better photocatalytic activity than the controlled TiO₂ film. In addition, the photocatalytic activity of the NiO/TiO₂ nanocomposite structure was enhanced as the thickness of the p -NiO film decreased, which was beneficial for the migration of the photogenerated carriers to the structural surface.

  15. A low-level needle counter

    International Nuclear Information System (INIS)

    Fujita, Y.; Taguchi, Y.; Imamura, M.; Inoue, T.; Tanaka, S.

    1977-01-01

    A small end-window type gas-flow counter which has a sharpened needle (anode) against the end-window plane (cathode) was developed for low-level counting of β particles to the amount of less than one count per hour in solid sources of relatively high specific activity. The advantage of the needle counter for low-level work is that being of a conical shape the active volume as against the window area is small. The background count rate of 0.0092+-0.0005 cpm was obtained for a 10 mm dia needle counter operating in GM mode and in anticoincidence with a well-type NaI(Tl) guard crystal with massive shields. The counter design and the counter characteristics are presented in detail. The needle counter is simple in design, low-cost and stable in long time operation. (author)

  16. Multimorbidity in Atlantic Canada and association with low levels of physical activity.

    Science.gov (United States)

    Keats, Melanie R; Cui, Yunsong; DeClercq, Vanessa; Dummer, Trevor J B; Forbes, Cynthia; Grandy, Scott A; Hicks, Jason; Sweeney, Ellen; Yu, Zhijie Michael; Parker, Louise

    2017-12-01

    Owing to an aging population and medical advances, the anticipated growth and prevalence of multimorbidity has been recognized as a significant challenge and priority in health care settings. Although physical activity has been shown to play a vital role in the primary and secondary prevention of chronic disease, much less is known about the relationship between physical activity and multimorbidity. The objective of the present study was to examine the relationship between physical activity levels and multimorbidity in male and female adults after adjusting for key demographic, geographical, and lifestyle factors. The study drew data from a prospective cohort in Atlantic Canada (2009-2015). The sample included 18,709 participants between the ages of 35-69. Eighteen chronic diseases were identified. Physical activity levels were estimated based on the long form of the International Physical Activity Questionnaire. Using logistic regression analysis, we found that multimorbid individuals were significantly more likely to be physically inactive (OR=1.26; 95% CI 1.10, 1.44) after adjusting for key sociodemographic and lifestyle characteristics. Additional stratified analyses suggest that the magnitude of the effect between multimorbidity and physical activity was stronger for men (OR=1.41; 95% CI 1.12, 1.79) than women (OR=1.18; CI 1.00, 1.39) and those living in rural (OR=1.43; CI 1.10, 1.85) versus urban (OR=1.20; CI 1.02, 141) areas. Given the generally low levels of physical activity across populations and a growing prevalence of multimorbidity, there is a need for a prospective study to explore causal associations between physical activity, multimorbidity, and health outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Low Temperature Diffusion Transformations in Fe-Ni-Ti Alloys During Deformation and Irradiation

    Science.gov (United States)

    Sagaradze, Victor; Shabashov, Valery; Kataeva, Natalya; Kozlov, Kirill; Arbuzov, Vadim; Danilov, Sergey; Ustyugov, Yury

    2018-03-01

    The deformation-induced dissolution of Ni3Ti intermetallics in the matrix of austenitic alloys of Fe-36Ni-3Ti type was revealed in the course of their cascade-forming neutron irradiation and cold deformation at low temperatures via employment of Mössbauer method. The anomalous deformation-related dissolution of the intermetallics has been explained by the migration of deformation-induced interstitial atoms from the particles into a matrix in the stress field of moving dislocations. When rising the deformation temperature, this process is substituted for by the intermetallics precipitation accelerated by point defects. A calculation of diffusion processes has shown the possibility of the realization of the low-temperature diffusion of interstitial atoms in configurations of the crowdions and dumbbell pairs at 77-173 K. The existence of interstitial atoms in the Fe-36Ni alloy irradiated by electrons or deformed at 77 K was substantiated in the experiments of the electrical resistivity measurements.

  18. A novel Ni{sup 2+}-doped Ag{sub 3}PO{sub 4} photocatalyst with high photocatalytic activity and enhancement mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Song, Limin, E-mail: songlmnk@sohu.com [College of Environment and Chemical Engineering, State Key Laboratory of Hollow-Fiber Membrane Materials and Membrane Processes, Tianjin Polytechnic University, Tianjin 300387 (China); Chen, Zewen; Li, Tongtong [College of Environment and Chemical Engineering, State Key Laboratory of Hollow-Fiber Membrane Materials and Membrane Processes, Tianjin Polytechnic University, Tianjin 300387 (China); Zhang, Shujuan, E-mail: zhangshujuan@tust.edu.cn [College of Science, Tianjin University of Science & Technology, Tianjin, 300457 (China)

    2017-01-15

    Ni{sup 2+}-doped Ag{sub 3}PO{sub 4} (Ni{sup 2+}-Ag{sub 3}PO{sub 4}) photocatalysts with superhigh activity for photodegradation of organic pollutants were prepared by a simple hydrothermal method. The photocatalysts were characterized with X-ray powder diffractometry, transmission electron microscopy, ultraviolet–visible absorption spectroscopy, X-ray photoelectron spectroscopy, measurement of total organic carbon, and electron paramagnetic resonance spectrometry. The photocatalysts were evaluated by methyl orange (MO) photodegradation experiments under visible light irradiation (λ > 420 nm). Comparative analysis showed the optimal doping dosage was 0.05 mol/L Ni{sup 2+}. The optimal Ni{sup 2+}-Ag{sub 3}PO{sub 4} has an MO photodegradation rate constant four times larger than pure Ag{sub 3}PO{sub 4}. The photocatalytic ratio of 40 mg/L MO over the optimal Ni{sup 2+}-Ag{sub 3}PO{sub 4} after 10 min is 89%, which indicates excellent photocatalytic ability in high-concentration MO solutions. The Ni{sup 2+} doping into Ag{sub 3}PO{sub 4} can increase the level of band gap, and accelerate the utilization of photons and the separation of photo-generated charges. Therefore, the Ni{sup 2+} doping into Ag{sub 3}PO{sub 4} is responsible for the enhancement of photocatalytic ability. - Highlights: • Ni{sup 2+}-modified with higher photodegradation ability was synthesized. • ·OH radicals were the main active species in the oxidation of MO. • The doping of Ni{sup 2+} in Ag{sub 3}PO{sub 4} is responsible for the enhanced activity.

  19. Support effects on hydrotreating activity of NiMo catalysts

    International Nuclear Information System (INIS)

    Dominguez-Crespo, M.A.; Arce-Estrada, E.M.; Torres-Huerta, A.M.; Diaz-Garcia, L.; Cortez de la Paz, M.T.

    2007-01-01

    The effect of the gamma alumina particle size on the catalytic activity of NiMoS x catalysts prepared by precipitation method of aluminum acetate at pH = 10 was studied. The structural characterization of the supports was measured by using XRD, pyridine FTIR-TPD and nitrogen physisorption. NiMo catalysts were characterized during the preparation steps (annealing and sulfidation) using transmission electron microscopy (TEM). Hydrogen TPR studies of the NiMo catalysts were also carried out in order to correlate their hydrogenating properties and their catalytic functionality. Catalytic tests were carried out in a pilot plant at 613, 633 and 653 K temperatures. The results showed that the rate constants of hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and hydrodearomatizing (HDA) at 613-653 K decreased in the following order: A > B > C corresponding to the increase of NiMoS particle size associated to these catalysts

  20. TiFeCoNi oxide thin film - A new composition with extremely low electrical resistivity at room temperature

    International Nuclear Information System (INIS)

    Yang, Ya-Chu; Tsau, Chun-Huei; Yeh, Jien-Wei

    2011-01-01

    We show the electrical resistivity of a TiFeCoNi oxide thin film. The electrical resistivity of the TiFeCoNi thin film decreased sharply after a suitable period of oxidation at high temperature. The lowest resistivity of the TiFeCoNi oxide film was 35 ± 3 μΩ-cm. The low electrical resistivity of the TiFeCoNi oxide thin film was attributed to Ti, which is more reactive than the other elements, reacting with oxygen at the initial stage of annealing. The low resistivity is caused by the remaining electrons.

  1. Features of Pd-Ni-Fe solder system for vacuum brazing of low alloy steels

    International Nuclear Information System (INIS)

    Radzievskij, V.N.; Kurochko, R.S.; Lotsmanov, S.N.; Rymar', V.I.

    1975-01-01

    The brazing solder of the Pd-Ni-Fe alloyed with copper and lithium, in order to decrease the melting point and provide for a better spreading, when soldered in vacuum ensures a uniform strength of soldered joints with the base metal of low-alloyed steels of 34KHNIM-type. The properties of low-alloyed steel joints brazed with the Pd-Ni-Fe-system solder little depend on the changes in the soldering parameters. The soldered joint keeps a homogeneous structure after all the stages of heat treatment (annealing, quenching and tempering)

  2. Nanocrystalline soft ferromagnetic Ni-Co-P thin film on Al alloy by low temperature electroless deposition

    International Nuclear Information System (INIS)

    Aal, A. Abdel; Shaaban, A.; Hamid, Z. Abdel

    2008-01-01

    Soft ferromagnetic ternary Ni-Co-P films were deposited onto Al 6061 alloy from low temperature Ni-Co-P electroless plating bath. The effect of deposition parameters, such as time and pH, on the plating rate of the deposit were examined. The results showed that the plating rate is a function of pH bath and the highest coating thickness can be obtained at pH value from 8 to10. The surface morphology, phase structure and the magnetic properties of the prepared films have been investigated using scanning electron microscopy (SEM), X-ray diffraction analysis (XRD) and vibrating magnetometer device (VMD), respectively. The deposit obtained at optimum conditions showed compact and smooth with nodular grains structure and exhibited high magnetic moments and low coercivety. Potentiodynamic polarization corrosion tests were used to study the general corrosion behavior of Al alloys, Ni-P and Ni-Co-P coatings in 3.5% NaCl solution. It was found that Ni-Co-P coated alloy demonstrated higher corrosion resistance than Ni-P coating containing same percent of P due to the Co addition. The Ni-Co-P coating with a combination of high corrosion resistance, high hardness and excellent magnetic properties would be expected to enlarge the applications of the aluminum alloys

  3. The Effect of Surface Site Ensembles on the Activity and Selectivity of Ethanol Electrooxidation by Octahedral PtNiRh Nanoparticles.

    Science.gov (United States)

    Erini, Nina; Beermann, Vera; Gocyla, Martin; Gliech, Manuel; Heggen, Marc; Dunin-Borkowski, Rafal E; Strasser, Peter

    2017-06-01

    Direct ethanol fuel cells are attractive power sources based on a biorenewable, high energy-density fuel. Their efficiency is limited by the lack of active anode materials which catalyze the breaking of the C-C bond coupled to the 12-electron oxidation to CO 2 . We report shape-controlled PtNiRh octahedral ethanol oxidation electrocatalysts with excellent activity and previously unachieved low onset potentials as low as 0.1 V vs. RHE, while being highly selective to complete oxidation to CO 2 . Our comprehensive characterization and in situ electrochemical ATR studies suggest that the formation of a ternary surface site ensemble around the octahedral Pt 3 Ni 1 Rh x nanoparticles plays a crucial mechanistic role for this behavior. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. HTLV-1 Tax-induced NFκB activation is independent of Lys-63-linked-type polyubiquitination

    International Nuclear Information System (INIS)

    Gohda, Jin; Irisawa, Masato; Tanaka, Yuetsu; Sato, Shintaro; Ohtani, Kiyoshi; Fujisawa, Jun-ichi; Inoue, Jun-ichiro

    2007-01-01

    Human T-cell leukemia virus type 1 (HTLV-1) Tax-induced activation of nuclear factor-κB (NFκB) is thought to play a critical role in T-cell transformation and onset of adult T-cell leukemia. However, the molecular mechanism of the Tax-induced NFκB activation remains unknown. One of the mitogen-activated protein kinase kinase kinses (MAP3Ks) members, TAK1, plays a critical role in cytokine-induced activation of NFκB, which involves lysine 63-linked (K63) polyubiquitination of NEMO, a noncatalytic subunit of the IκB kinase complex. Here we show that Tax induces K63 polyubiquitination of NEMO. However, TAK1 is dispensable for Tax-induced NFκB activation, and deubiquitination of the K63 polyubiquitin chain failed to block Tax-induced NFκB activation. In addition, silencing of other MAP3Ks, including MEKK1, MEKK3, NIK, and TPL-2, did not affect Tax-induced NFκB activation. These results strongly suggest that unlike cytokine signaling, Tax-induced NFκB activation does not involve K63 polyubiquitination-mediated MAP3K activation

  5. Microwave-activated Ni/carbon catalysts for highly selective hydrogenation of nitrobenzene to cyclohexylamine.

    Science.gov (United States)

    Lu, Xinhuan; He, Jie; Jing, Run; Tao, Peipei; Nie, Renfeng; Zhou, Dan; Xia, Qinghua

    2017-06-01

    Biocarbon supported Ni catalysts have been prepared by facile impregnation of Ni species by microwave-heating and used for selective hydrogenation of nitrobenzene to cyclohexylamine. These catalysts were characterized by X-ray diffraction, Raman spectra, N2 sorption measurement, X-ray photoelectron spectroscopy, temperature programmed reduction of H2 and H2 temperature-programmed desorption. The morphology and particle size of catalysts were imaged by scanning electron microscope and transmission electron microscope. For the hydrogenation of nitrobenzene to cyclohexylamine, 10%Ni/CSC-II(b) exhibits the best catalytic activity to achieve 100 mol% conversion of nitrobenzene and 96.7% selectivity of cyclohexylamine under reaction conditions of 2.0 MPa H2 and 200 °C, ascribed to high dispersion of Ni species and formation of nanosized Ni particles on the support aided by microwave-heating. Thus-prepared Ni/CSC catalyst is greatly activated, in which the addition of precious metal like Rh is totally avoided.

  6. NiCo2O4 nanosheets in-situ grown on three dimensional porous Ni film current collectors as integrated electrodes for high-performance supercapacitors

    Science.gov (United States)

    Wang, Tao; Guo, Ying; Zhao, Bo; Yu, Shuhui; Yang, Hai-Peng; Lu, Daniel; Fu, Xian-Zhu; Sun, Rong; Wong, Ching-Ping

    2015-07-01

    Three dimensional interconnected hierarchical porous Ni films are easily fabricated as effective current collectors through hydrogen bubble template electrochemical deposition. The binder-free integrated electrodes of spinel NiCo2O4 nanosheets directly coated the three dimensional porous Ni films are facilely obtained through successively electrochemical co-deposition of Ni/Co alloy layer then followed by subsequent annealing at 350 °C in air. Compared with NiCo2O4 nanosheets on smooth Ni foil or porous NiO/Ni film electrodes, the porous NiCo2O4/Ni integrated film electrodes for supercapacitors demonstrate remarkably higher area specific capacitance. The porous NiCo2O4/Ni film electrodes also exhibit excellent rate capability and cycling stability. The super electrochemical capacitive performances are attributed to the unique integrated architecture of NiCo2O4 nanosheets in-situ grown on three dimensional continuous hierarchical porous Ni collector collectors, which could provide large electrode-electrolyte interface area, high active sites, low contact resistance between current collector and active materials, fast electron conduction and ion/electrolyte diffusion.

  7. Synchrotron radiation-based {sup 61}Ni Mössbauer spectroscopic study of Li(Ni{sub 1/3}Mn{sub 1/3}Co{sub 1/3})O{sub 2} cathode materials of lithium ion rechargeable battery

    Energy Technology Data Exchange (ETDEWEB)

    Segi, Takashi, E-mail: segi.takashi@kki.kobelco.com [Kobelco Research Institute, Inc. (Japan); Masuda, Ryo; Kobayashi, Yasuhiro [Kyoto University, Research Reactor Institute (Japan); Tsubota, Takayuki [Kobelco Research Institute, Inc. (Japan); Yoda, Yoshitaka [Japan Synchrotron Radiation Research Institute, Research and Utilization Division (Japan); Seto, Makoto [Kyoto University, Research Reactor Institute (Japan)

    2016-12-15

    Layered rocksalt type oxides, such as Li(Ni{sub 1/3}Mn{sub 1/3}Co{sub 1/3})O{sub 2}, are widely used as the cathode active materials of lithium-ion rechargeable batteries. Because the nickel ions are associated with the role of the charge compensation at discharge and charge, the {sup 61}Ni Mössbauer measurements at 6 K using synchrotron radiation were performed to reveal the role of Ni. The Ni ions of the active materials play two roles for the redox process between the charge and discharge states of lithium-ion batteries. Half of the total Ni ions change to the low-spin Ni {sup 3+} with Jahn-Teller distortion from the Ni {sup 2+} ions of the discharge state. The remainder exhibit low-spin state divalent Ni ions.

  8. Noble-metal-free NiO@Ni-ZnO/reduced graphene oxide/CdS heterostructure for efficient photocatalytic hydrogen generation

    Science.gov (United States)

    Chen, Fayun; Zhang, Laijun; Wang, Xuewen; Zhang, Rongbin

    2017-11-01

    Noble-metal-free semiconductor materials are widely used for photocatalytic hydrogen generation because of their low cost. ZnO-based heterostructures with synergistic effects exhibit an effective photocatalytic activity. In this work, NiO@Ni-ZnO/reduced graphene oxide (rGO)/CdS heterostructures are synthesized by a multi-step method. rGO nanosheets and CdS nanoparticles were introduced into the heterostructures via a redox reaction and light-assisted growth, respectively. A novel Ni-induced electrochemical growth method was developed to prepare ZnO rods from Zn powder. NiO@Ni-ZnO/rGO/CdS heterostructures with a wide visible-light absorption range exhibited highly photocatalytic hydrogen generation rates under UV-vis and visible light irradiation. The enhanced photocatalytic activity is attributed to the Ni nanoparticles that act as cocatalysts for capturing photoexcited electrons and the improved synergistic effect between ZnO and CdS due to the rGO nanosheets acting as photoexcited carrier transport channels.

  9. Low-level waste research and development activities of the Department of Energy

    International Nuclear Information System (INIS)

    Barainca, M.J.

    1986-01-01

    This paper presents an overview of the technical activities of the Department of Energy's Defense and Nuclear Energy Low-Level Radioactive Waste Management Programs (LLWPs). Although each Program was established with a different purpose, the technologies developed and demonstrated by each are transferable for use in both the commercial and DOE sectors. This paper presents an overview of the technical activities being pursued through both the Defense and Nuclear Energy LLWP's. These technologies have been placed in the following categories; Criteria and Standards, Systems Analysis, Information and Technology Transfer, Waste Treatment and Wast Form, Improved Near Surface Disposal, Greater Confinement Disposal, Corrective Measures, and Monitoring

  10. Ga-Doped Pt-Ni Octahedral Nanoparticles as a Highly Active and Durable Electrocatalyst for Oxygen Reduction Reaction.

    Science.gov (United States)

    Lim, JeongHoon; Shin, Hyeyoung; Kim, MinJoong; Lee, Hoin; Lee, Kug-Seung; Kwon, YongKeun; Song, DongHoon; Oh, SeKwon; Kim, Hyungjun; Cho, EunAe

    2018-04-11

    Bimetallic PtNi nanoparticles have been considered as a promising electrocatalyst for oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells (PEMFCs) owing to their high catalytic activity. However, under typical fuel cell operating conditions, Ni atoms easily dissolve into the electrolyte, resulting in degradation of the catalyst and the membrane-electrode assembly (MEA). Here, we report gallium-doped PtNi octahedral nanoparticles on a carbon support (Ga-PtNi/C). The Ga-PtNi/C shows high ORR activity, marking an 11.7-fold improvement in the mass activity (1.24 A mg Pt -1 ) and a 17.3-fold improvement in the specific activity (2.53 mA cm -2 ) compared to the commercial Pt/C (0.106 A mg Pt -1 and 0.146 mA cm -2 ). Density functional theory calculations demonstrate that addition of Ga to octahedral PtNi can cause an increase in the oxygen intermediate binding energy, leading to the enhanced catalytic activity toward ORR. In a voltage-cycling test, the Ga-PtNi/C exhibits superior stability to PtNi/C and the commercial Pt/C, maintaining the initial Ni concentration and octahedral shape of the nanoparticles. Single cell using the Ga-PtNi/C exhibits higher initial performance and durability than those using the PtNi/C and the commercial Pt/C. The majority of the Ga-PtNi nanoparticles well maintain the octahedral shape without agglomeration after the single cell durability test (30,000 cycles). This work demonstrates that the octahedral Ga-PtNi/C can be utilized as a highly active and durable ORR catalyst in practical fuel cell applications.

  11. Modelling the active site of NiFe hydrogenases: new catalysts for the electro-production of H2 and mechanistic studies

    International Nuclear Information System (INIS)

    Canaguier, S.

    2009-01-01

    NiFe hydrogenases are unique metalloenzymes that catalyze H + /H 2 interconversion with remarkable efficiency close to the thermodynamic potential. Their active site consists of a hetero-bimetallic complex containing a nickel ion in a sulphur-rich environment connected by two thiolate bridges to an organometallic cyano-carbonyl iron moiety. In order to improve the understanding of the enzymatic mechanism and to obtain new base-metal electrocatalysts for H 2 production, we synthesized a series of bio-inspired low molecular weight model complexes with the butterfly structure Ni(μ-S 2 )M (M= Ru, Mn and Fe). All these compounds displayed a catalytic activity of hydrogen production. Modulating the electronic and steric properties of the ruthenium center allowed optimizing the catalytic performances of these compounds in terms of stability, catalytic rate and overpotential. Mechanistic studies of the catalytic cycle of the Ni-Ru complexes have also been carried out. They allowed us to suggest a bio-relevant bridging hydride as the catalytic intermediate. Finally, we synthesized one of the first Ni-Fe complexes that is both a structural and a functional model of NiFe hydrogenase. (author) [fr

  12. Elementary study of encapsulation of radioisotope battery prototype based on 63Ni radio-voltaic effect

    International Nuclear Information System (INIS)

    Gao Hui; Zhang Huaming; Luo Shunzhong; Wang Heyi; Fu Zhonghua

    2012-01-01

    For isotope battery application, it is necessary to encapsulate in a certain method. After having accomplished selection of material composing and proportion, procedure and encapsulating process based on GD3217Y detector. the different types of device come from untouched, loaded by slip of stainless steel with or without 63 Ni isotope were encapsulated respectively. Despite necessary reliability of package has been evaluated in the previous work. in view of specialty due to the incorporation of radioactive isotopes into device, the reliability issue must be further taken into account for actual application. Hence, we emphasize on the comparison about electrical capability of types of devices under the different situations, namely, before and after encapsulation, the natural aging and artificial accelerated aging. The results of the comparison indicate that the adoption of the method of the encapsulation supply effectively stable electrical capability at the condition of ensuring safety of radioactive source besides improving environmental adaptability for device. Further, it offers technological support for the encapsulation of radioisotope battery based on β radio-voltaic effect. (authors)

  13. Fatigue strain mapping via digital image correlation for Ni-based superalloys: The role of thermal activation on cube slip

    International Nuclear Information System (INIS)

    Mello, Alberto W.; Nicolas, Andrea; Sangid, Michael D.

    2017-01-01

    A deformation mechanism map for a Ni-based superalloy is presented during cyclic loading at low (300 °C), intermediate (550 °C), and high (700 °C) temperatures for low (0.7%) and high (1.0%) applied strain amplitudes. Strain mapping is performed via digital image correlation (DIC) during interrupted fatigue experiments at elevated temperatures at 1, 10, 100 and 1000 cycles, for each specified loading and temperature condition. The DIC measurements are performed in a scanning electron microscope, which allows high-resolution measurements of heterogeneous slip events and a vacuum environment to ensure stability of the speckle pattern for DIC at high temperatures. The cumulative fatigue experiments show that the slip bands are present in the first cycle and intensify with number of cycles; resulting in highly localized strain accumulation. The strain mapping results are combined with microstructure characterization via electron backscatter diffraction. The combination of crystal orientations and high-resolution strain measurements was used to determine the active slip planes. At low temperatures, slip bands follow the {111} octahedral planes. However, as temperature increases, both the {111} octahedral and {100} cubic slip planes accommodate strain. The activation of cubic slip via cross-slip within the ordered intermetallic γ’ phase has been well documented in Ni-based superalloys and is generally accepted as the mechanism responsible for the anomalous yield phenomenon. The results in this paper represent an important quantifiable study of cubic slip system activity at the mesoscale in polycrystalline γ-γ’ Ni-based superalloys, which is a key advancement to calibrate the thermal activation components of polycrystalline deformation models.

  14. Fatigue strain mapping via digital image correlation for Ni-based superalloys: The role of thermal activation on cube slip

    Energy Technology Data Exchange (ETDEWEB)

    Mello, Alberto W.; Nicolas, Andrea; Sangid, Michael D., E-mail: msangid@purdue.edu

    2017-05-17

    A deformation mechanism map for a Ni-based superalloy is presented during cyclic loading at low (300 °C), intermediate (550 °C), and high (700 °C) temperatures for low (0.7%) and high (1.0%) applied strain amplitudes. Strain mapping is performed via digital image correlation (DIC) during interrupted fatigue experiments at elevated temperatures at 1, 10, 100 and 1000 cycles, for each specified loading and temperature condition. The DIC measurements are performed in a scanning electron microscope, which allows high-resolution measurements of heterogeneous slip events and a vacuum environment to ensure stability of the speckle pattern for DIC at high temperatures. The cumulative fatigue experiments show that the slip bands are present in the first cycle and intensify with number of cycles; resulting in highly localized strain accumulation. The strain mapping results are combined with microstructure characterization via electron backscatter diffraction. The combination of crystal orientations and high-resolution strain measurements was used to determine the active slip planes. At low temperatures, slip bands follow the {111} octahedral planes. However, as temperature increases, both the {111} octahedral and {100} cubic slip planes accommodate strain. The activation of cubic slip via cross-slip within the ordered intermetallic γ’ phase has been well documented in Ni-based superalloys and is generally accepted as the mechanism responsible for the anomalous yield phenomenon. The results in this paper represent an important quantifiable study of cubic slip system activity at the mesoscale in polycrystalline γ-γ’ Ni-based superalloys, which is a key advancement to calibrate the thermal activation components of polycrystalline deformation models.

  15. Electrodeposition and characterization of nanocrystalline CoNiFe films

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y.; Wang, Q.P. [Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027 (China); Cai, C. [School of Chemistry and chemical engineering, Ningxia University, Yinchuan 750021 (China); Yuan, Y.N. [Department of Materials and Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027 (China); Cao, F.H. [Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027 (China); Zhang, Z., E-mail: eaglezzy@zjuem.zju.edu.cn [Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027 (China); Zhang, J.Q. [Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027 (China); State Key Laboratory for Corrosion and Protection of Metals, Shenyang 110016 (China)

    2012-02-29

    Nanocrystalline Co{sub 45}Ni{sub 10}Fe{sub 24} films have been fabricated using cyclic voltammetry technique from the solutions containing sulfate, then characterized by scanning electron microscopy, X-ray diffraction and vibrating sample magnetometer. Meanwhile, Electrochemical Impedance Spectroscopy technique has been employed to probe into the nucleation/growth behavior of Co{sub 45}Ni{sub 10}Fe{sub 24} films. The results show that, the obtained Co{sub 45}Ni{sub 10}Fe{sub 24} film possesses low coercivity of 973.3 A/m and high saturation magnetic flux density of 1.59 Multiplication-Sign 10{sup 5} A/m. Under the experimental conditions, the nucleation/growth process of Co{sub 45}Ni{sub 10}Fe{sub 24} films is mainly under activation control. With the increase of the applied cathodic potential bias, the charge transfer resistance for CoNiFe deposition decreases exponentially. - Highlights: Black-Right-Pointing-Pointer Nanocrystalline Co{sub 45}Ni{sub 10}Fe{sub 24} film is obtained using cyclic voltammetry technique. Black-Right-Pointing-Pointer Nanocrystalline Co{sub 45}Ni{sub 10}Fe{sub 24} possesses low coercivity of 973.3 A/m. Black-Right-Pointing-Pointer Nanocrystalline Co{sub 45}Ni{sub 10}Fe{sub 24} possesses high saturation magnetic flux density. Black-Right-Pointing-Pointer The nucleation/growth process of CoNiFe films is mainly under activation control. Black-Right-Pointing-Pointer The charge transfer resistance for CoNiFe deposition decreases exponentially.

  16. When NiO@Ni Meets WS2 Nanosheet Array: A Highly Efficient and Ultrastable Electrocatalyst for Overall Water Splitting.

    Science.gov (United States)

    Wang, Dewen; Li, Qun; Han, Ce; Xing, Zhicai; Yang, Xiurong

    2018-01-24

    The development of low-cost, high-efficiency, and stable bifunctional electrocatalysts toward the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is of paramount importance for large-scale water splitting. Here, we develop a new strategy for the first design and synthesis of a NiO@Ni decorated WS 2 nanosheet array on carbon cloth (NiO@Ni/WS 2 /CC) composite. This composite serves as a unique three-dimensional (3D) synergistic electrocatalyst that not only combines the intrinsic properties of individual NiO@Ni and WS 2 , but also exhibits significantly improved HER and OER activities when compared to that of pure NiO@Ni and WS 2 . This electrocatalyst possesses Pt-like activity for HER and exhibits better OER performance than that for commercial RuO 2 , as well as demonstrating superior long-term durability in alkaline media. Furthermore, it enables an alkaline electrolyzer with a current density of 10 mA cm -2 at a cell voltage as 1.42 V, which is the lowest one among all reported values to date. The excellent performance is mainly attributed to the unique 3D configuration and multicomponent synergies among NiO, Ni, and WS 2 . Our findings provide a new idea to design advanced bifunctional catalysts for water splitting.

  17. Effects of a short-term exercise training program on aerobic fitness, fatigue, health perception and activity level of subjects with multiple sclerosis.

    Science.gov (United States)

    Mostert, S; Kesselring, J

    2002-04-01

    Multiple sclerosis (MS) patients of an inpatient rehabilitation program have been randomly assigned to an exercise training (MS-ET) or nontraining group (MS-NI). Before and after 4 weeks of aerobic exercise training, a graded maximal exercise test with measurement of gas exchange and a lung function test was administered to all 26 patients fulfilling the inclusion criteria. Activity level, fatigue and health perception were measured by means of questionnaires. Twenty-six healthy persons served as control group and were matched in respect of age, gender and activity level. Training intervention consisted of 5x30 min sessions per week of bicycle exercise with individualised intensity. Compared with baseline, the MS training group demonstrated a significant rightward placement of the aerobic threshold (AT) (VO2+13%; work rate [WR])+11%), an improvement of health perception (vitality+46%; social interaction+36%), an increase of activity level (+17%) and a tendency to less fatigue. No changes were observed for the MS-NI group and the control groups. Maximal aerobic capacity and lung function were not changed by either training or nontraining in all four groups. Overall compliance to the training program was quite low (65%), whereas incidence of symptom exacerbation by physical activity has been lower than expected (6%).

  18. Understanding low-level radioactive waste. National Low-Level Radioactive Waste Management Program

    International Nuclear Information System (INIS)

    1983-10-01

    Chapters are devoted to: background and policymaking for low-level waste management; commercial low-level waste generation; Department of Energy low-level waste generation; low-level waste treatment; packaging and transportation; commercial low-level waste disposal; Department of Energy low-level waste disposal; Department of Energy low-level waste management program; and laws and regulations

  19. Ordered Mesoporous NiCeAl Containing Catalysts for Hydrogenolysis of Sorbitol to Glycols

    Science.gov (United States)

    Zhou, Zhiwei; Zhang, Jiaqi; Qin, Juan; Li, Dong; Wu, Wenliang

    2018-03-01

    Cellulose-derived sorbitol is emerging as a feasible and renewable feedstock for the production of value-added chemicals. Highly active and stable catalyst is essential for sorbitol hydrogenolysis. Ordered mesoporous M- xNi yCeAl catalysts with different loadings of nickel and cerium species were successfully synthesized via one-pot evaporation-induced self-assembly strategy (EISA) and their catalytic performance were tested in the hydrogenolysis of sorbitol. The physical chemical properties for the catalysts were characterized by XRD, N2 physisorption, H2-TPR, H2 impulse chemisorption, ICP and TEM techniques. The results showed that the ordered mesopores with uniform pore sizes can be obtained and the Ni nanoparticles around 6 nm in size were homogeneously dispersed in the mesopore channels. A little amount of cerium species introduced would be beneficial to their textural properties resulting in higher Ni dispersion, metal area and smaller size of Ni nanoparticles. The M-10Ni2CeAl catalyst with Ni and Ce loading of 10.9 and 6.3 wt % shows better catalytic performance than other catalysts, and the yield of 1,2-PG and EG can reach 56.9% at 493 K and 6 MPa pressure for 8 h after repeating reactions for 12 times without obvious deterioration of physical and chemical properties. Ordered mesoporous M-NiCeAl catalysts are active and stable in sorbitol hydrogenolysis.

  20. The Influence of oxide additives on Ni/Al2O3 catalysts in low temperature methane steam reforming

    International Nuclear Information System (INIS)

    Lazar, Mihaela; Dan, Monica; Mihet, Maria; Almasan, Valer

    2009-01-01

    Hydrogen is industrially produced by methane steam reforming. The process is catalytic and the usual catalyst is based on Ni as the active element. The main problem of this process is its inefficiency. It requires high temperatures at which Ni also favors the formation of graphite, which deactivates the catalysts. Ni has the advantage of being much cheaper than noble metal catalysts, so many researches are done in order to improve the properties of supported Ni catalysts and to decrease the temperature at which the process is energetically efficient. In order to obtain catalysts with high activity and stability, it is essential to maintain the dispersion of the active phase (Ni particles) and the stability of the support. Both properties can be improved by addition of a second oxide to the support. In this paper we present the results obtained in preparation and characterization of Ni/Al 2 O 3 catalysts modified by addition of CeO 2 and La 2 O 3 to alumina support. The following catalysts were prepared by impregnation method: Ni/Al 2 O 3 , Ni/CeO 2 -Al 2 O 3 and Ni/La 2 O 3 -Al 2 O 3 (10 wt.% Ni and 6 wt.% additional oxide). The catalytic surface was characterized by N 2 adsorption - desorption isotherms. The hydrogen - surface bond was characterized by Thermo-Programmed-Desorption (TPD) method. All catalysts were tested in steam reforming reaction of methane in the range of 600 - 700 deg. C, at atmospheric pressure working with CH 4 :H 2 O ratio of 1:3. The modified catalysts showed a better catalytic activity and selectivity for H 2 and CO 2 formation, at lower temperatures than the simple Ni/Al 2 O 3 catalyst. (authors)

  1. Corticosterone levels predict survival probabilities of Galápagos marine iguanas during El Niño events

    Science.gov (United States)

    Romero, L. Michael; Wikelski, Martin

    2001-01-01

    Plasma levels of corticosterone are often used as a measure of “stress” in wild animal populations. However, we lack conclusive evidence that different stress levels reflect different survival probabilities between populations. Galápagos marine iguanas offer an ideal test case because island populations are affected differently by recurring El Niño famine events, and population-level survival can be quantified by counting iguanas locally. We surveyed corticosterone levels in six populations during the 1998 El Niño famine and the 1999 La Niña feast period. Iguanas had higher baseline and handling stress-induced corticosterone concentrations during famine than feast conditions. Corticosterone levels differed between islands and predicted survival through an El Niño period. However, among individuals, baseline corticosterone was only elevated when body condition dropped below a critical threshold. Thus, the population-level corticosterone response was variable but nevertheless predicted overall population health. Our results lend support to the use of corticosterone as a rapid quantitative predictor of survival in wild animal populations. PMID:11416210

  2. Closure Plan for Active Low Level Burial Grounds

    Energy Technology Data Exchange (ETDEWEB)

    SKELLY, W.A.

    2000-11-16

    This plan has been prepared in response to direction from the U.S. Department of Energy. The purpose of the plan is to define approaches that will be implemented to ensure protection of the public and the environment when active Low-Level Burial Grounds (LLBGs) at the Hanford Site are closed. Performance assessments for active burial grounds in the 200 East and West 200 Areas provide current estimates of potential environmental contamination and doses to the ''maximum exposed individual'' from burial ground operation and closure and compare dose estimates to performance objective dose limits for the facilities. This is an Operational Closure Plan. The intent of the guidance in DOE Order 435.1 is that this plan will be a living document, like the facility performance assessments, and will be revised periodically through the operational life of the LLBGs to reflect updated information on waste inventory. management practices, facility transition planning, schedule dates, assessments of post-closure performance, and environmental consequences. Out year dates identified in this plan are tentative. A Final Closure Plan will be prepared in the future when the timing and extent of closure-related activities for LLBGs can be established with greater certainty. After current operations at the LLBGs are concluded, this plan proposes transitioning of these facilities to the Environmental Restoration Program. This action will enable the Environmental Restoration Program to design and implement consistent and coordinated final remedial actions for active and inactive LLBGs. Active and inactive burial grounds in the 200 West and 200 East Areas are commingled. This plan describes approaches that will be implemented during Interim Closure, Final Closure, and Institutional Control Periods to prepare LLBGs for surface barriers, and the construction of barriers, as well as the scope of inspection, monitoring and maintenance practices that will be performed during

  3. Low-level waste workshops. Final report

    International Nuclear Information System (INIS)

    1983-01-01

    The Low-Level Radioactive Waste Policy Act of 1980 specifies that each state is responsible for the disposal of the low-level waste which is generated within its boundaries. The Act states that such wastes can be most safely and efficiently managed on a regional basis through compacts. It also defines low-level waste as waste which is not classified as high-level radioactive waste, transuranic waste, spent nuclear fuel, or by-product material as defined in the Atomic Energy Act of 1954. The Policy Act also stipulates that regional agreements or compacts shall not be applicable to the transportation, management, or disposal of low-level radioactive waste from atomic energy defense activities or federal research and development activities. It also specifies that agreements or compacts shall take affect on January 1, 1986, upon Congressional approval. In February 1983, the US Department of Energy awarded a grant to the Council of State Governments' Midwestern Office. The grant was to be used to fund workshops for legislation on low-level radioactive waste issues. The purpose of the workshops was to provide discussion specifically on the Midwest Interstate Compact on Low-Level Radioactive Waste. Legislators from the states which were eligible to join the compact were invited: Delaware, Illinois, Indiana, Iowa, Kentucky, Maryland, Michigan, Minnesota, Missouri, North Dakota, Ohio, South Dakota and Wisconsin. Virginia, Kansas and Nebraska were also eligible but had joined other compacts. Consequently, they weren't invited to the workshops. The Governor's office of West Virginia expressed interest in the compact, and its legislators were invited to attend a workshop. Two workshops were held in March. This report is a summary of the proceedings which details the concerns of the compact and expresses the reasoning behind supporting or not supporting the compact

  4. Chemical vapor deposition of NiSi using Ni(PF3)4 and Si3H8

    International Nuclear Information System (INIS)

    Ishikawa, M.; Muramoto, I.; Machida, H.; Imai, S.; Ogura, A.; Ohshita, Y.

    2007-01-01

    NiSi x films were deposited using chemical vapor deposition (CVD) with a Ni(PF 3 ) 4 and Si 3 H 8 /H 2 gas system. The step coverage quality of deposited NiSi x was investigated using a horizontal type of hot-wall low pressure CVD reactor, which maintained a constant temperature throughout the deposition area. The step coverage quality improved as a function of the position of the gas flow direction, where PF 3 gas from decomposition of Ni(PF 3 ) 4 increased. By injecting PF 3 gas into the Ni(PF 3 ) 4 and Si 3 H 8 /H 2 gas system, the step coverage quality markedly improved. This improvement in step coverage quality naturally occurred when PF 3 gas was present, indicating a strong relationship. The Si/Ni deposit ratio at 250 deg. C is larger than at 180 deg. C. It caused a decreasing relative deposition rate of Ni to Si. PF 3 molecules appear to be adsorbed on the surface of the deposited film and interfere with faster deposition of active Ni deposition species

  5. Evaluation of damage induced by high irradiation levels on α-Ni-Ni3Si eutectic structure

    Science.gov (United States)

    Camacho Olguin, Carlos Alberto; Garcia-Borquez, Arturo; González-Rodríguez, Carlos Alberto; Loran-Juanico, Jose Antonio; Cruz-Mejía, Hector

    2015-06-01

    to 380 dpa at 650°C in a Tandetron linear accelerator. The level of irradiation dose was chosen similar to the irradiation conditions of the next-generation nuclear reactors. The theoretical maximum depth of the DII (maximum depth of damage (MDD)) was calculated as 1.35 µm using the SRIM-2013 program; the laminar microstructure of the eutectic was simulated using the lattice parameters of the eutectic before irradiation. The experimental MDD was 1.47 µm, as determined through transmission electron microscope (TEM) images and the DII was characterized using µX-ray diffraction and TEM. The elimination of cubic phase of the intermetallic Ni3Si, the suppression of lamellae of the α-Ni phase, the generation of dislocation loops and lines, all of these changes generated by the irradiation are clear evidences that the DII was severe. Based on theoretical and experimental evidence, we propose that the amount of phases, alternate of lamellae with different chemical concentrations of silicon and lamellae spatial distribution have a direct relation with the severe evolution of the DII.

  6. Preparation and Characterization of Surface Photocatalytic Activity with NiO/TiO2 Nanocomposite Structure

    Directory of Open Access Journals (Sweden)

    Jian-Zhi Chen

    2015-07-01

    Full Text Available This study achieved a nanocomposite structure of nickel oxide (NiO/titanium dioxide (TiO2 heterojunction on a TiO2 film surface. The photocatalytic activity of this structure evaluated by decomposing methylene blue (MB solution was strongly correlated to the conductive behavior of the NiO film. A p-type NiO film of high concentration in contact with the native n-type TiO2 film, which resulted in a strong inner electrical field to effectively separate the photogenerated electron-hole pairs, exhibited a much better photocatalytic activity than the controlled TiO2 film. In addition, the photocatalytic activity of the NiO/TiO2 nanocomposite structure was enhanced as the thickness of the p-NiO film decreased, which was beneficial for the migration of the photogenerated carriers to the structural surface.

  7. Do low levels of physical activity in female adolescents cause ...

    African Journals Online (AJOL)

    Background. The increase in obesity levels in South African adolescents is attributed to an energy imbalance such that physical inactivity is causally related to adiposity. However, in some settings obesity occurs in spite of high physical activity levels. Objectives. To examine objectively measured physical activity levels of ...

  8. Hydrogen Activation by Biomimetic [NiFe]-Hydrogenase Model Containing Protected Cyanide Cofactors

    Science.gov (United States)

    Manor, Brian C.; Rauchfuss, Thomas B.

    2013-01-01

    Described are experiments that allow incorporation of cyanide cofactors and hydride substrate into active site models [NiFe]-hydrogenases (H2ases). Complexes of the type (CO)2(CN)2Fe(pdt)Ni(dxpe), (dxpe = dppe, 1; dxpe = dcpe, 2) bind the Lewis acid B(C6F5)3 (BArF3) to give the adducts (CO)2(CNBArF3)2Fe(pdt)Ni(dxpe), (1(BArF3)2, 2(BArF3)2). Upon decarbonylation using amine oxides, these adducts react with H2 to give hydrido derivatives Et4N[(CO)(CNBArF3)2Fe(H)(pdt)Ni(dxpe)], (dxpe = dppe, Et4N[H3(BArF3)2]; dxpe = dcpe, Et4N[H4(BArF3)2]). Crystallographic analysis shows that Et4N[H3(BArF3)2] generally resembles the active site of the enzyme in the reduced, hydride-containing states (Ni-C/R). The Fe-H…Ni center is unsymmetrical with rFe-H = 1.51(3) and rNi-H = 1.71(3) Å. Both crystallographic and 19F NMR analysis show that the CNBArF3− ligands occupy basal and apical sites. Unlike cationic Ni-Fe hydrides, [H3(BArF3)2]− and [H4(BArF3)2]− oxidize at mild potentials, near the Fc+/0 couple. Electrochemical measurements indicate that in the presence of base, [H3(BArF3)2]− catalyzes the oxidation of H2. NMR evidence indicates dihydrogen bonding between these anionic hydrides and ammonium salts, which is relevant to the mechanism of hydrogenogenesis. In the case of Et4N[H3(BArF3)2], strong acids such as HCl induce H2 release to give the chloride Et4N[(CO)(CNBArF3)2Fe(pdt)(Cl)Ni(dppe)]. PMID:23899049

  9. Simulation about Self-absorption of Ni-63 Nuclear Battery Using Monte Carlo Code

    International Nuclear Information System (INIS)

    Kim, Tae Ho; Kim, Ji Hyun

    2014-01-01

    The radioisotope batteries have an energy density of 100-10000 times greater than chemical batteries. Also, Li ion battery has the fundamental problems such as short life time and requires recharge system. In addition to these things, the existing batteries are hard to operate at internal human body, national defense arms or space environment. Since the development of semiconductor process and materials technology, the micro device is much more integrated. It is expected that, based on new semiconductor technology, the conversion device efficiency of betavoltaic battery will be highly increased. Furthermore, the radioactivity from the beta particle cannot penetrate a skin of human body, so it is safer than Li battery which has the probability to explosion. In the other words, the interest for radioisotope battery is increased because it can be applicable to an artificial internal organ power source without recharge and replacement, micro sensor applied to arctic and special environment, small size military equipment and space industry. However, there is not enough data for beta particle fluence from radioisotope source using nuclear battery. Beta particle fluence directly influences on battery efficiency and it is seriously affected by radioisotope source thickness because of self-absorption effect. Therefore, in this article, we present a basic design of Ni-63 nuclear battery and simulation data of beta particle fluence with various thickness of radioisotope source and design of battery

  10. Simulation about Self-absorption of Ni-63 Nuclear Battery Using Monte Carlo Code

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Ho; Kim, Ji Hyun [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-05-15

    The radioisotope batteries have an energy density of 100-10000 times greater than chemical batteries. Also, Li ion battery has the fundamental problems such as short life time and requires recharge system. In addition to these things, the existing batteries are hard to operate at internal human body, national defense arms or space environment. Since the development of semiconductor process and materials technology, the micro device is much more integrated. It is expected that, based on new semiconductor technology, the conversion device efficiency of betavoltaic battery will be highly increased. Furthermore, the radioactivity from the beta particle cannot penetrate a skin of human body, so it is safer than Li battery which has the probability to explosion. In the other words, the interest for radioisotope battery is increased because it can be applicable to an artificial internal organ power source without recharge and replacement, micro sensor applied to arctic and special environment, small size military equipment and space industry. However, there is not enough data for beta particle fluence from radioisotope source using nuclear battery. Beta particle fluence directly influences on battery efficiency and it is seriously affected by radioisotope source thickness because of self-absorption effect. Therefore, in this article, we present a basic design of Ni-63 nuclear battery and simulation data of beta particle fluence with various thickness of radioisotope source and design of battery.

  11. When NiO@Ni Meets WS2 Nanosheet Array: A Highly Efficient and Ultrastable Electrocatalyst for Overall Water Splitting

    Directory of Open Access Journals (Sweden)

    Dewen Wang

    2017-12-01

    Full Text Available The development of low-cost, high-efficiency, and stable bifunctional electrocatalysts toward the hydrogen evolution reaction (HER and oxygen evolution reaction (OER is of paramount importance for large-scale water splitting. Here, we develop a new strategy for the first design and synthesis of a NiO@Ni decorated WS2 nanosheet array on carbon cloth (NiO@Ni/WS2/CC composite. This composite serves as a unique three-dimensional (3D synergistic electrocatalyst that not only combines the intrinsic properties of individual NiO@Ni and WS2, but also exhibits significantly improved HER and OER activities when compared to that of pure NiO@Ni and WS2. This electrocatalyst possesses Pt-like activity for HER and exhibits better OER performance than that for commercial RuO2, as well as demonstrating superior long-term durability in alkaline media. Furthermore, it enables an alkaline electrolyzer with a current density of 10 mA cm–2 at a cell voltage as 1.42 V, which is the lowest one among all reported values to date. The excellent performance is mainly attributed to the unique 3D configuration and multicomponent synergies among NiO, Ni, and WS2. Our findings provide a new idea to design advanced bifunctional catalysts for water splitting.

  12. Ni/La2O3 catalyst containing low content platinum-rhodium for the dehydrogenation of N2H4·H2O at room temperature

    Science.gov (United States)

    O, Song-Il; Yan, Jun-Min; Wang, Hong-Li; Wang, Zhi-Li; Jiang, Qing

    2014-09-01

    Ni/La2O3 nanocatalyst with Pt and Rh content as low as 5 mol%, respectively, is successfully synthesized by a facile co-reduction method in the presence of hexadecyl trimethyl ammonium chloride aqueous solution under ambient atmosphere. Interestingly, the resulted Ni/La2O3 catalyst with low cost exhibits excellent catalytic activity to dehydrogenation of hydrous hydrazine (N2H4·H2O), producing hydrogen with 100% selectivity at room temperature (298 K), which represents a promising step toward the practical application for N2H4·H2O system on fuel cells.

  13. Simple synthesis of mesoporous FeNi/graphitic carbon nanocomposite catalysts and study on their activities in catalytic cracking of toluene

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yangang, E-mail: ygwang8136@gmail.com [Department of Environmental Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093 (China); Chen, Yuting; Yao, Mingcui [Department of Environmental Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093 (China); Qin, Hengfei; Kang, Shifei; Li, Xi [Department of Environmental Science and Engineering, Fudan University, Shanghai 200433 (China); Zuo, Yuanhui; Zhang, Xiaodong [Department of Environmental Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093 (China); Cui, Li-Feng, E-mail: lifeng.cui@gmail.com [Department of Environmental Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093 (China)

    2015-11-01

    Mesoporous FeNi alloy/graphitic carbon nanocomposite catalysts with different Fe/Ni molar ratios have been synthesized through a simple solid–liquid grinding/templating method using mesoporous silica SBA-15 as the template. Metal nitrates and natural soybean oil were respectively used as the magnetic particle precursors and carbon source, which can be infiltrated into the silica template after simple impregnation, grinding and subsequent heat treatment. X-ray diffraction, nitrogen adsorption–desorption, transmission electron microscopy and thermogravimetric analysis techniques were used to characterize the samples. It is observed that high contents of FeNi alloy nanoparticles with the sizes of 3–6 nm are well dispersed into the walls of graphitic mesoporous carbon matrix, and the resulting nanocomposites have a uniform mesostructure with a high specific surface area and large pore volume. Because of these properties, the obtained FeNi/graphitic carbon nanocomposites can be used as novel catalysts for the catalytic cracking of toluene and exhibit a higher activity and stability than FeNi/commercial activated carbon (AC) catalyst. After a period of 810 min reaction at 700 °C, the toluene conversion on the FeNi/graphitic carbon nanocomposites can be maintained at a level of more than 75% and this value is 2.5 times as high as that of the FeNi/AC catalyst. - Highlights: • Mesoporous FeNi alloy/graphitic carbon nanocomposites (FeNi/GCN) were synthesized. • High contents of FeNi alloy nanoparticles are well embedded into the graphitic carbon walls. • The obtained FeNi/GCN catalysts have a high surface area and uniform mesostructure. • The FeNi/GCN catalysts exhibited excellent catalytic performance in the cracking of toluene.

  14. The Use of Refundable Tax Credits to Increase Low-Income Children's After-School Physical Activity Level.

    Science.gov (United States)

    Dunton, Genevieve; Ebin, Vicki J; Efrat, Merav W; Efrat, Rafael; Lane, Christianne J; Plunkett, Scott

    2015-06-01

    The current study investigates the extent to which a refundable tax credit could be used to increase low-income children's after-school physical activity levels. An experimental study was conducted evaluating the effectiveness of an intervention offering a simulated refundable tax credit to parents of elementary-school-age children (n = 130) for enrollment in after-school physical activity programs. A randomized controlled design was used, with data collected at baseline, immediately following the 4-month intervention (postintervention), and 6 weeks after the end of the intervention (follow-up). Evaluation measures included (1) enrollment rate, time spent, weekly participation frequency, duration of enrollment, and long-term enrollment patterns in after-school physical activity programs and (2) moderate to vigorous physical activity. The simulated tax credits did not significantly influence low-income children's rates of enrollment in after-school physical activity programs, frequency of participation, time spent in after-school physical activity programs, and overall moderate-to-vigorous intensity physical activity at postintervention or follow-up. The use of refundable tax credits as incentives to increase participation in after-school physical activity programs in low-income families may have limited effectiveness. Lawmakers might consider other methods of fiscal policy to promote physical activity such as direct payment to after-school physical activity program providers for enrolling and serving a low-income child in a qualified program, or improvements to programming and infrastructure.

  15. High-performance germanium n+/p junction by nickel-induced dopant activation of implanted phosphorus at low temperature

    International Nuclear Information System (INIS)

    Huang Wei; Lu Chao; Yu Jue; Wei Jiang-Bin; Chen Chao-Wen; Wang Jian-Yuan; Xu Jian-Fang; Li Cheng; Chen Song-Yan; Lai Hong-Kai; Wang Chen; Liu Chun-Li

    2016-01-01

    High-performance Ge n + /p junctions were fabricated at a low formation temperature from 325 °C to 400 °C with a metal(nickel)-induced dopant activation technique. The obtained NiGe electroded Ge n + /p junction has a rectification ratio of 5.6× 10 4 and a forward current of 387 A/cm 2 at −1 V bias. The Ni-based metal-induced dopant activation technique is expected to meet the requirement of the shallow junction of Ge MOSFET. (paper)

  16. A novel bifunctional Ni-doped TiO2 inverse opal with enhanced SERS performance and excellent photocatalytic activity

    Science.gov (United States)

    Li, Xuehong; Wu, Yun; Shen, Yuhua; Sun, Yan; Yang, Ying; Xie, Anjian

    2018-01-01

    Three-dimensional inverse opal photonic microarray (IOPM) structure exhibits good qualities in structural regularity and interconnectivity, such as high specific surface area, large pore volume, uniform pore size, and ordered periodic construction. Here, a novel nickel-doped titanium dioxide IOPM (Ni-TiO2 IOPM) was fabricated for the first time as a bifunctional material for the applications of surface-enhanced Raman scattering (SERS) substrate and photocatalyst. The Ni doping could change the defect concentration of the substrate to enhance the SERS effect, and could increase the light absorption of the substrate in visible region. The synergistic effect of Ni doping and the periodically ordered porous structure enhanced both SERS sensitivity and photocatalytic activity. As a SERS substrate, the Ni-TiO2 IOPM exhibited highly sensitive detection capability for 4-mercaptobenzoic acid (4-MBA) at a concentration as low as 1 × 10-11 M. Under simulated sunlight, about 95% of the methylene blue (MB) was degraded within 90 min when Ni-TiO2 IOPM was used as the photocatalytst. The Ni-TiO2 IOPM prepared in this work may be a promising bifunctional SERS substrate candidate for organic sewage detection and environment protection. In addition, the fabrication strategy can be extended to synthesize other nanomaterials with orderly and porous structure.

  17. Investigation of the Enzyme activities of Alkaline Phosphatase, Lactate Dehydrogenase, Transaminase and Histopathological Changes of Liver after Exposure to NiO and NiO Nanoparticles in Rats

    Directory of Open Access Journals (Sweden)

    Aidin Marzban

    2017-08-01

    Conclusion: The results of this study demonstrate that exposure to different doses of NiONPs and NiO can induce different degrees of damage in a dose dependent manner. Thus, increasing level of liver enzymes and histopathological changes confirmed NiONPs and NiO toxicity.

  18. Effect of surface properties of NiFe2O4 nanoparticles synthesized by dc thermal plasma route on antimicrobial activity

    Science.gov (United States)

    Bhosale, S. V.; Ekambe, P. S.; Bhoraskar, S. V.; Mathe, V. L.

    2018-05-01

    The present work reports the role of surface properties of NiFe2O4 nanoparticles on the antimicrobial activity. The NiFe2O4 nanoparticles were synthesized by gas phase condensation and chemical co-precipitation route. These nanoparticles were extensively investigated using X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and electro-kinetic property measurements. The HRTEM was used to analyze surface morphology of nickel ferrite nanoparticles obtained by two different routes. Electro-kinetic properties of the nanoparticles under investigation were recorded, analyzed and correlated with the antimicrobial properties. It was observed that nickel ferrite nanoparticles synthesized by thermal plasma route (NFOTP) formed highly stable colloidal solution as compared to chemically synthesized (NFOCP), as the later tends to agglomerate due to low surface charge. The antimicrobial activity of NiFe2O4 nanoparticles were investigated on two Gram positive bacteria Staphylococcus aureus and Streptococcus pyogenes, two Gram negative bacteria Escherichia coli and Salmonella typhimurium and one fungal species Candida albicans. It was noted that the surface properties of NiFe2O4 particles have revealing effect on the antimicrobial activity. The NFOTP nanoparticles showed significant activity for gram negative E. coli bacteria however no activity was observed for other bacteria's and fungi under study. Moreover NFOCP particles did not show any significant activity for both bacteria's and fungi. Further, antimicrobial activity of nickel ferrite nanoparticles were studied even for different concentration to obtain the minimum inhibition concentration (MIC).

  19. Directions in low-level radioactive waste management. The siting process: establishing a low-level waste-disposal facility

    International Nuclear Information System (INIS)

    1982-11-01

    The siting of a low-level radioactive waste disposal facility encompasses many interrelated activities and, therefore, is inherently complex. The purpose of this publication is to assist state policymakers in understanding the nature of the siting process. Initial discussion focuses on the primary activities that require coordination during a siting effort. Available options for determining site development, licensing, regulating, and operating responsibilities are then considered. Additionally, the document calls attention to technical services available from federal agencies to assist states in the siting process; responsibilities of such agencies are also explained. The appendices include a conceptual plan for scheduling siting activities and an explanation of the process for acquiring agreement state status. An agreement state takes responsibility for licensing and regulating a low-level waste facility within its borders

  20. Precipitation in 20 Cr-25 Ni type stainless steel irradiated at low temperatures in a thermal reactor (AGR)

    International Nuclear Information System (INIS)

    Taylor, C.

    1983-01-01

    The effects of irradiation on the microstructure of AGR fuel rod cladding have been studied by analytical electron microscopy. Two alloys were investigated, the standard 20 Cr-25 Ni steel stabilised with Nb and a variant containing less Nb but strengthened with a dispersion of TiN precipitates. Irradiation at 360 deg C to 480 deg C produced (Ni, Si)-rich precipitates in both alloys; additionally the standard alloy contained (Ni, Nb, Si)-rich precipitates when irradiated at 440 deg C to 640 deg C. While similar features have been observed in other austenitic stainless steels irradiated in fast reactors, where the lattice-damage rate is greater than in a thermal reactor, their formation is not predicted by isothermal equilibrium diagrams. It is suggested here that the phases are irradiation-induced and that the total displacement damage is the controlling factor. Cladding solution-treated above 1050 deg C then irradiated at 2 -based reactor coolant occurred in cladding with low levels of cold-work at the outer surface, also resulting in Cr-rich carbide formation. (author)

  1. Development of low-activation design method for reduction of radioactive waste (3). Various types of low-activation concrete

    International Nuclear Information System (INIS)

    Kinno, Masaharu; Kimura, Ken-ichi; Fujikura, Yusuke

    2008-01-01

    Manufacturing tests by mixing together with low-activation aggregates, low-activation cements, low-activation additives, low-activation admixtures and low-activation neutron absorbers have been performed to develop low-activation concrete. After that, we developed various types (1/10, 1/20, 1/30, 1/50, 1/100, 1/300, 1/1,000, 1/3,000 and 1/10,000) of low-activation concrete composed of low-activation raw materials as very useful shielding material in a nuclear facility. The term '1/10 of low-activation concrete' denotes that the activity reduction rate to ordinary concrete is designed to be 1/10. By adopting some suitable types of low-activation concrete, most of the shielding concrete around ABWR and APWR are classified below clearance level on decommissioning. (author)

  2. Highly conductive and low cost Ni-PET flexible substrate for efficient dye-sensitized solar cells.

    Science.gov (United States)

    Su, Haijun; Zhang, Mingyang; Chang, Ya-Huei; Zhai, Peng; Hau, Nga Yu; Huang, Yu-Ting; Liu, Chang; Soh, Ai Kah; Feng, Shien-Ping

    2014-04-23

    The highly conductive and flexible nickel-polyethylene terephthalate (Ni-PET) substrate was prepared by a facile way including electrodeposition and hot-press transferring. The effectiveness was demonstrated in the counter electrode of dye-sensitized solar cells (DSSCs). The Ni film electrodeposition mechanism, microstructure, and DSSC performance for the Ni-PET flexible substrate were investigated. The uniform and continuous Ni film was first fabricated by electroplating metallic Ni on fluorine-doped tin oxide (FTO) and then intactly transferred onto PET via hot-pressing using Surlyn as the joint adhesive. The obtained flexible Ni-PET substrate shows low sheet resistance of 0.18Ω/□ and good chemical stability for the I(-)/I(3-) electrolyte. A high light-to-electric energy conversion efficiency of 7.89% was demonstrated in DSSCs system based on this flexible electrode substrate due to its high conductivity, which presents an improvement of 10.4% as compared with the general ITO-PEN flexible substrate. This method paves a facile and cost-effective way to manufacture various metals on a plastic nonconducive substrate beneficial for the devices toward flexible and rollable.

  3. One-step synthesis of N-doped activated carbon with controllable Ni nanorods for ethanol oxidation

    International Nuclear Information System (INIS)

    Shi, Wenjuan; Gao, Haiyan; Yu, Jianguo; Jia, Miaomiao; Dai, Tangming; Zhao, Yongnan; Xu, Jingjing; Li, Guodong

    2016-01-01

    N-doped activated carbons with controllable Ni nanorods (NiNC) catalysts were fabricated by a facile one-pot method for electrocatalytic oxidation of ethanol. The effects of carbon source and Ni precursor for the different microstructures of the forming Ni are discussed in this work. The sucrose and chloride ion are the key factors for forming nanorod-like nickel catalyst. The sizes of Ni nanorods can be controlled by the reactant ratios and influence the catalytic performance for ethanol oxidation. The doped N atoms are also used to improve the catalytic performance for ethanol oxidation. The NiNC–3 catalyst with the proper content and size of Ni exhibits an improved catalytic activity toward ethanol oxidation with a 5 times current density and 16 times rate constant in comparison with the NiNC–1 catalysts. A current density of 47.5 mA cm −2 is generated on NiNC–3 electrode. Furthermore, current density retention of 80.7% suggests an excellent cyclic stability after 1500 cycle on the NiNC–3 electrode. All of these elevated performances can be attributed to the relatively uniform nanorods size, as well as the excellent electrical conductivity and stability of the carbon support.

  4. Optimization of measurement techniques for very low-level radioactive waste material

    International Nuclear Information System (INIS)

    Hoffmann, R.; Leidenberger, B.

    1991-01-01

    Relative radiotoxicities of all relevant waste nuclides are defined and calculated according to the limits set by the German Radiation Protection Ordinance. The hard-to-detect nuclides (e.g. Fe-55, Ni-59, Ni-63) are found to be of minor radiological relevance, even if their abundance in certain waste categories is predominant. Standard beta or gamma measurements are highly sufficient if alpha contamination can be excluded. Twenty different detectors were tested and their suitability for release measurements, i.e. detection efficiencies, limits of detection and minimum measuring times, were determined using standards of C-14, Pm-147, Co-60, Cs-137, Sr-90/Y-90, Cr-51 and Am-241 in 5 geometries representative of contaminated waste material. In most geometries, proportional counters were found adequate for release measurements while for detection of alpha radiation in difficult geometries, small detectors (i.e. surface barrier detectors, photodiodes or Geiger-Muller counters) are needed

  5. Elementary study on encapsulation reliability of radioisotope battery prototype based on 63Ni Radio-Voltaic effect

    International Nuclear Information System (INIS)

    Gao Hui; Zhang Huaming; Luo Shunzhong; Wang Heyi

    2012-01-01

    For isotope battery application, it is necessary to encapsulate in a certain method. After having accomplished selection of material composing and proportion, procedure and encapsulating process based on GD3217Y detector, the different types of device come from untouched, loaded by slip of stainless steel with or without 63 Ni isotope were encapsulated respectively. Despite necessary reliability of package was evaluated in the previous work, in view of specialty due to the incorporation of radioactive isotopes into device, the reliability issue must be further taken into account for actual application. Hence, we emphasize on the comparison about electrical capability of types of devices under the different situations, namely, before and after encapsulation, the natural aging and artificial accelerated aging. The results of the comparison indicate that the adoption of the method of the encapsulation supplies effectively stable electrical capability at the condition of ensuring safety of radioactive source besides improving environmental adaptability for device. Further, it offers technological support for the encapsulation of radioisotope battery based on β radio-voltaic effect. (authors)

  6. Self-powered p-NiO/n-ZnO heterojunction ultraviolet photodetectors fabricated on plastic substrates

    Directory of Open Access Journals (Sweden)

    Md Rezaul Hasan

    2015-10-01

    Full Text Available A self-powered ultraviolet (UV photodetector (PD based on p-NiO and n-ZnO was fabricated using low-temperature sputtering technique on indium doped tin oxide (ITO coated plastic polyethylene terephthalate (PET substrates. The p-n heterojunction showed very fast temporal photoresponse with excellent quantum efficiency of over 63% under UV illumination at an applied reverse bias of 1.2 V. The engineered ultrathin Ti/Au top metal contacts and UV transparent PET/ITO substrates allowed the PDs to be illuminated through either frontside or backside. Morphology, structural, chemical, and optical properties of sputtered NiO and ZnO films were also investigated.

  7. Self-powered p-NiO/n-ZnO heterojunction ultraviolet photodetectors fabricated on plastic substrates

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Md Rezaul [Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Department of Electrical and Computer Engineering, George Mason University, 4400 University Drive, Fairfax, Virginia 22030 (United States); Xie, Ting; Liu, Guannan [Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Department of Electrical and Computer Engineering, University of Maryland, College Park, Maryland 20742 (United States); Barron, Sara C. [Materials Measurement Science Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Nguyen, Nhan V. [Semiconductor and Dimensional Metrology Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Motayed, Abhishek [Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States); Rao, Mulpuri V. [Department of Electrical and Computer Engineering, George Mason University, 4400 University Drive, Fairfax, Virginia 22030 (United States); Debnath, Ratan, E-mail: ratan.debnath@nist.gov [Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)

    2015-10-01

    A self-powered ultraviolet (UV) photodetector (PD) based on p-NiO and n-ZnO was fabricated using low-temperature sputtering technique on indium doped tin oxide (ITO) coated plastic polyethylene terephthalate (PET) substrates. The p-n heterojunction showed very fast temporal photoresponse with excellent quantum efficiency of over 63% under UV illumination at an applied reverse bias of 1.2 V. The engineered ultrathin Ti/Au top metal contacts and UV transparent PET/ITO substrates allowed the PDs to be illuminated through either frontside or backside. Morphology, structural, chemical, and optical properties of sputtered NiO and ZnO films were also investigated.

  8. Hydrogen production via reforming of biogas over nanostructured Ni/Y catalyst: Effect of ultrasound irradiation and Ni-content on catalyst properties and performance

    Energy Technology Data Exchange (ETDEWEB)

    Sharifi, Mahdi [Chemical Engineering Faculty, Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz (Iran, Islamic Republic of); Reactor and Catalysis Research Center (RCRC), Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz (Iran, Islamic Republic of); Haghighi, Mohammad, E-mail: haghighi@sut.ac.ir [Chemical Engineering Faculty, Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz (Iran, Islamic Republic of); Reactor and Catalysis Research Center (RCRC), Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz (Iran, Islamic Republic of); Abdollahifar, Mozaffar [Chemical Engineering Faculty, Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz (Iran, Islamic Republic of); Reactor and Catalysis Research Center (RCRC), Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz (Iran, Islamic Republic of)

    2014-12-15

    Highlights: • Synthesis of nanostructured Ni/Y catalyst by sonochemical and impregnation methods. • Enhancement of size distribution and active phase dispersion by employing sonochemical method. • Evaluation of biogas reforming over Ni/Y catalyst with different Ni-loadings. • Preparation of highly active and stable catalyst with low Ni content for biogas reforming. • Getting H{sub 2}/CO very close to equilibrium ratio by employing sonochemical method. - Abstract: The effect of ultrasound irradiation and various Ni-loadings on dispersion of active phase over zeolite Y were evaluated in biogas reforming for hydrogen production. X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray, Brunauer–Emmett–Teller, Fourier transform infrared analysis and TEM analysis were employed to observe the characteristics of nanostructured catalysts. The characterizations implied that utilization of ultrasound irradiation enhanced catalyst physicochemical properties including high dispersion of Ni on support, smallest particles size and high catalyst surface area. The reforming reactions were carried out at GHSV = 24 l/g.h, P = 1 atm, CH{sub 4}/CO{sub 2} = 1 and temperature range of 550–850 °C. Activity test displayed that ultrasound irradiated Ni(5 wt.%)/Y had the best performance and the activity remained stable during 600 min. Furthermore, the proposed reaction mechanism showed that there are three major reaction channels in biogas reforming.

  9. Effect of Low-Level Laser Stimulation on EEG

    Directory of Open Access Journals (Sweden)

    Jih-Huah Wu

    2012-01-01

    Full Text Available Conventional laser stimulation at the acupoint can induce significant brain activation, and the activation is theoretically conveyed by the sensory afferents. Whether the insensible low-level Laser stimulation outside the acupoint could also evoke electroencephalographic (EEG changes is not known. We designed a low-level laser array stimulator (6 pcs laser diode, wavelength 830 nm, output power 7 mW, and operation frequency 10 Hz to deliver insensible laser stimulations to the palm. EEG activities before, during, and after the laser stimulation were collected. The amplitude powers of each EEG frequency band were analyzed. We found that the low-level laser stimulation was able to increase the power of alpha rhythms and theta waves, mainly in the posterior head regions. These effects lasted at least 15 minutes after cessation of the laser stimulation. The amplitude power of beta activities in the anterior head regions decreased after laser stimulation. We thought these EEG changes comparable to those in meditation.

  10. Effect of low-level laser stimulation on EEG.

    Science.gov (United States)

    Wu, Jih-Huah; Chang, Wen-Dien; Hsieh, Chang-Wei; Jiang, Joe-Air; Fang, Wei; Shan, Yi-Chia; Chang, Yang-Chyuan

    2012-01-01

    Conventional laser stimulation at the acupoint can induce significant brain activation, and the activation is theoretically conveyed by the sensory afferents. Whether the insensible low-level Laser stimulation outside the acupoint could also evoke electroencephalographic (EEG) changes is not known. We designed a low-level laser array stimulator (6 pcs laser diode, wavelength 830 nm, output power 7 mW, and operation frequency 10 Hz) to deliver insensible laser stimulations to the palm. EEG activities before, during, and after the laser stimulation were collected. The amplitude powers of each EEG frequency band were analyzed. We found that the low-level laser stimulation was able to increase the power of alpha rhythms and theta waves, mainly in the posterior head regions. These effects lasted at least 15 minutes after cessation of the laser stimulation. The amplitude power of beta activities in the anterior head regions decreased after laser stimulation. We thought these EEG changes comparable to those in meditation.

  11. The Enhanced Catalytic Activities of Asymmetric Au-Ni Nanoparticle Decorated Halloysite-Based Nanocomposite for the Degradation of Organic Dyes

    Science.gov (United States)

    Jia, Lei; Zhou, Tao; Xu, Jun; Li, Xiaohui; Dong, Kun; Huang, Jiancui; Xu, Zhouqing

    2016-02-01

    Janus particles (JPs) are unique among the nano-/microobjects because they provide asymmetry and can thus impart drastically different chemical or physical properties. In this work, we have fabricated the magnetic halloysite nanotube (HNT)-based HNTs@Fe3O4 nanocomposite (NCs) and then anchored the Janus Au-Ni or isotropic Au nanoparticles (NPs) to the surface of external wall of sulfydryl modified magnetic nanotubes. The characterization by physical methods authenticates the successful fabrication of two different magnetic HNTs@Fe3O4@Au and HNTs@Fe3O4@Au-Ni NCs. The catalytic activity and recyclability of the two NCs have been evaluated considering the degradation of Congo red (CR) and 4-nitrophenol (4-NP) using sodium borohydride as a model reaction. The results reveal that the symmetric Au NPs participated NCs display low activity in the degradation of the above organic dyes. However, a detailed kinetic study demonstrates that the employ of bimetallic Janus Au-Ni NPs in the NCs indicates enhanced catalytic activity, owing to the structurally specific nature. Furthermore, the magnetic functional NCs reported here can be used as recyclable catalyst which can be recovered simply by magnet.

  12. Irradiation-Induced Solute Clustering in a Low Nickel FeMnNi Ferritic Alloy

    International Nuclear Information System (INIS)

    Meslin, E.; Barbu, A.; Radiguet, B.; Pareige, P.; Toffolon, C.

    2011-01-01

    Understanding the radiation embrittlement of reactor pressure vessel (RPV) steels is required to be able to operate safely a nuclear power plant or to extend its lifetime. The mechanical properties degradation is partly due to the clustering of solute under irradiation. To gain knowledge about the clustering process, a Fe-1.1 Mn-0.7 Ni (at.%) alloy was irradiated in a test reactor at two fluxes of 0.15 and 9 *10 17 n E≥1MeV . m -2 .s -1 and at increasing doses from 0.18 to 1.3 *10 24 n E≥1MeV ) . m -2 at 300 degrees C. Atom probe tomography (APT) experiments revealed that the irradiation promotes the formation in the α iron matrix of Mn/Mn and/or Ni/Ni pair correlations at low dose and Mn-Ni enriched clusters at high dose. These clusters dissolve partially after a thermal treatment at 400 degrees C. Based on a comparison with thermodynamic calculations, we show that the solute clustering under irradiation can just result from an induced mechanism. (authors)

  13. Optimization of Silicon parameters as a betavoltaic battery: Comparison of Si p-n and Ni/Si Schottky barrier

    International Nuclear Information System (INIS)

    Rahmani, Faezeh; Khosravinia, Hossein

    2016-01-01

    Theoretical studies on the optimization of Silicon (Si) parameters as the base of betavoltaic battery have been presented using Monte Carlo simulations and the state equations in semiconductor to obtain maximum power. Si with active area of 1 cm 2 has been considered in p-n junction and Schottky barrier structure to collect the radiation induced-charge from 10 mCi cm −2 of Nickle-63 ( 63 Ni) Source. The results show that the betavoltaic conversion efficiency in the Si p-n structure is about 2.7 times higher than that in the Ni/Si Schottky barrier structure. - Highlights: • Silicon parameters were studied in betavoltaic batteries. • Studied betavoltaic batteries include p-n and Schottky barrier structures. • The p-n structure has higher conversion efficiency.

  14. Population-Level Exposure to Particulate Air Pollution during Active Travel: Planning for Low-Exposure, Health-Promoting Cities.

    Science.gov (United States)

    Hankey, Steve; Lindsey, Greg; Marshall, Julian D

    2017-04-01

    Providing infrastructure and land uses to encourage active travel (i.e., bicycling and walking) are promising strategies for designing health-promoting cities. Population-level exposure to air pollution during active travel is understudied. Our goals were a ) to investigate population-level patterns in exposure during active travel, based on spatial estimates of bicycle traffic, pedestrian traffic, and particulate concentrations; and b ) to assess how those exposure patterns are associated with the built environment. We employed facility-demand models (active travel) and land use regression models (particulate concentrations) to estimate block-level ( n = 13,604) exposure during rush-hour (1600-1800 hours) in Minneapolis, Minnesota. We used the model-derived estimates to identify land use patterns and characteristics of the street network that are health promoting. We also assessed how exposure is correlated with indicators of health disparities (e.g., household income, proportion of nonwhite residents). Our work uses population-level rates of active travel (i.e., traffic flows) rather than the probability of walking or biking (i.e., "walkability" or "bikeability") to assess exposure. Active travel often occurs on high-traffic streets or near activity centers where particulate concentrations are highest (i.e., 20-42% of active travel occurs on blocks with high population-level exposure). Only 2-3% of blocks (3-8% of total active travel) are "sweet spots" (i.e., high active travel, low particulate concentrations); sweet spots are located a ) near but slightly removed from the city-center or b ) on off-street trails. We identified 1,721 blocks (~ 20% of local roads) where shifting active travel from high-traffic roads to adjacent low-traffic roads would reduce exposure by ~ 15%. Active travel is correlated with population density, land use mix, open space, and retail area; particulate concentrations were mostly unchanged with land use. Public health officials and

  15. Incineration of low level and mixed wastes: 1986

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    The University of California at Irvine, in cooperation with the Department of Energy, American Society of Mechanical Engineers, and chapters of the Health Physics Society, coordinated this conference on the Incineration of Low-Level Radioactive and Mixed Wastes, with the guidance of professionals active in the waste management community. The conference was held in April 22-25, 1986 at Sheraton airport hotel Charlotte, North Carolina. Some of the papers' titles were: Protection and safety of different off-gas treatment systems in radioactive waste incineration; performance assessment of refractory samples in the Los Alamos controlled-Air incinerator; incineration systems for low-level and mixed wastes; incineration of low-level radioactive waste in Switzerland-operational experience and future activities

  16. Regional characteristics of the effects of the El Niño-Southern Oscillation on the sea level in the China Sea

    Science.gov (United States)

    Wang, Hui; Liu, Kexiu; Wang, Aimei; Feng, Jianlong; Fan, Wenjing; Liu, Qiulin; Xu, Yao; Zhang, Zengjian

    2018-05-01

    Based on coastal tide level, satellite altimetry, and sea surface temperature (SST) data of offshore areas of China's coast and the equatorial Pacific Ocean, the regional characteristics of the effects of the El Niño-Southern Oscillation (ENSO) on the sea level in the China Sea were investigated. Singular value decomposition results show a significant teleconnection between the sea level in the China Sea and the SST of the tropical Pacific Ocean; the correlation coefficient decreases from south to north. Data from tide gauges along China's coast show that the seasonal sea-level variations are significantly correlated with the ENSO. In addition, China's coast was divided into three regions based on distinctive regional characteristics. Results obtained show that the annual amplitude of sea level was low during El Niño developing years, and especially so during the El Niño year. The ENSO intensity determined the response intensity of the annual amplitude of the sea level. The response region (amplitude) was relatively large for strong ENSO intensities. Significant oscillation periods at a timescale of 4-7 years existed in the sea level of the three regions. The largest amplitude of oscillation was 1.5 cm, which was the fluctuation with the 7-year period in the South China Sea. The largest amplitude of oscillation in the East China Sea was about 1.3 cm. The amplitude of oscillation with the 6-year period in the Bohai Sea and Yellow Sea was the smallest (less than 1 cm).

  17. Thermal treatment to enhance saturation magnetization of superparamagnetic Ni nanoparticles while maintaining low coercive force

    Science.gov (United States)

    Ishizaki, Toshitaka; Yatsugi, Kenichi; Akedo, Kunio

    2018-05-01

    Superparamagnetic nanoparticles capped by insulators have the potential to decrease eddy current and hysteresis losses. However, the saturation magnetization ( M s) decreases significantly with decreasing the particle size. In this study, superparamagnetic Ni nanoparticles having the mean size of 11.6 ± 1.8 nm were synthesized from the reduction of Ni(II) acetylacetonate in oleylamine with the addition of trioctylphosphine, indicating the coercive force ( H c) less than 1 Oe. Thermal treatments of the Ni nanoparticles were investigated as a method to enhance the M s. The results indicated that the M s was enhanced by an increase of the Ni mass ratio with increasing thermal treatment temperature. However, the decomposition behavior of the capping layers indicated that their alkyl chains actively decomposed at temperatures above 523 K to form Ni3P via reaction between Ni and P, resulting in particle growth with a significant increase in the H c. Therefore, the optimal temperature was determined to be 473 K, which increased the Ni ratio without formation of Ni3P while maintaining particle sizes with superparamagnetic properties. Further, the M s could be improved by 22% (relative to the as-synthesized Ni nanoparticles) after thermal treatment at 473 K while maintaining the H c to be less than 1 Oe.

  18. Direct selenylation of mixed Ni/Fe metal-organic frameworks to NiFe-Se/C nanorods for overall water splitting

    Science.gov (United States)

    Xu, Bo; Yang, He; Yuan, Lincheng; Sun, Yiqiang; Chen, Zhiming; Li, Cuncheng

    2017-10-01

    Development of low-cost, highly active bifunctional catalyst for efficient overall water splitting based on earth-abundant metals is still a great challenging task. In this work, we report a NiFe-Se/C composite nanorod as efficient non-precious-metal electrochemical catalyst derived from direct selenylation of a mixed Ni/Fe metal-organic framework. The as-obtained catalyst requires low overpotential to drive 10 mA cm-2 for HER (160 mV) and OER (240 mV) in 1.0 M KOH, respectively, and its catalytic activity is maintained for at least 20 h. Moreover, water electrolysis using this catalyst achieves high water splitting current density of 10 mA cm-2 at cell voltage of 1.68 V.

  19. Ni nanoparticles@Ni-Mo nitride nanorod arrays: a novel 3D-network hierarchical structure for high areal capacitance hybrid supercapacitors.

    Science.gov (United States)

    Ruan, Yunjun; Lv, Lin; Li, Zhishan; Wang, Chundong; Jiang, Jianjun

    2017-11-23

    Because of the advanced nature of their high power density, fast charge/discharge time, excellent cycling stability, and safety, supercapacitors have attracted intensive attention for large-scale applications. Nevertheless, one of the obstacles for their further development is their low energy density caused by sluggish redox reaction kinetics, low electroactive electrode materials, and/or high internal resistance. Here, we develop a facile and simple nitridation process to successfully synthesize hierarchical Ni nanoparticle decorated Ni 0.2 Mo 0.8 N nanorod arrays on a nickel foam (Ni-Mo-N NRA/NF) from its NiMoO 4 precursor, which delivers a high areal capacity of 2446 mC cm -2 at a current density of 2 mA cm -2 and shows outstanding cycling stability. The superior performance of the Ni-Mo-N NRA/NF can be ascribed to the metallic conductive nature of the Ni-Mo nitride, the fast surface redox reactions for the electrolyte ions and electrode materials, and the low contacted resistance between the active materials and the current collectors. Furthermore, a hybrid supercapacitor (HSC) is assembled using the Ni-Mo-N NRA/NF as the positive electrode and reduced graphene oxide (RGO) as the negative electrode. The optimized HSC exhibits excellent electrochemical performance with a high energy density of 40.9 W h kg -1 at a power density of 773 W kg -1 and a retention of 80.1% specific capacitance after 6000 cycles. These results indicate that the Ni-Mo-N NRA/NF have a promising potential for use in high-performance supercapacitors.

  20. CO methanation over supported bimetallic Ni-Fe catalysts: From computational studies towards catalyst optimization

    DEFF Research Database (Denmark)

    Kustov, Arkadii; Frey, Anne Mette; Larsen, Kasper Emil

    2007-01-01

    with compositions 25Fe75Ni and 50Fe50Ni showed significantly better activity and in some cases also a higher selectivity to methane compared with the traditional monometallic Ni and Fe catalysts. A catalyst with composition 25Fe75Ni was found to be the most active in CO hydrogenation for the MgAl2O4 support at low...... metal loadings. At high metal concentrations, the maximum for the methanation activity was found for catalysts with composition 50Ni50Fe both on the MgAl2O4 and Al2O3 supports. This difference can be attributed to a higher reducibility of the constituting metals with increasing metal concentration......DFT calculations combined with a computational screening method have previously shown that bimetallic Ni-Fe alloys should be more active than the traditional Ni-based catalyst for CO methanation. That was confirmed experimentally for a number of bimetallic Ni-Fe catalysts supported on MgAl2O4. Here...

  1. ACTIVITY TEST AND REGENERATION OF NiMo/Z CATALYST FOR HYDROCRACKING OF WASTE PLASTIC FRACTION TO GASOLINE FRACTION

    Directory of Open Access Journals (Sweden)

    Rodiansono Rodiansono

    2010-06-01

    Full Text Available Activity test and regeneration of NiMo/active natural zeolite catalyst for hydrocracking of waste plastic fraction of polyprophylene (PP type have been carried out. The catalysts was prepared by loading Mo followed by Ni Metals onto the natural zeolite (Z sample, then calcined at 500oC, oxidized and reduced at 400oC under nitrogen, oxygen and hydrogen stream, respectively. The characterization of catalysts including spesific surface area, average pore radius, and total pore volume were performed by gas sorption analyzer, amount of total acid sites was determined by gas sorption method, and acid site strength was confirmed by IR spectroscopy. The hydrocracking process was carried out in a semi-flow reactor system at 360 oC and catalyst:feed ratio 0.5 under hydrogen stream (150 mL/hour. The feed was vaporized from the pyrolisis reactor into the hydrocracking reactor. A liquid product was collected and analyzed by gas chromatography (GC and gas chromatography-mass spectroscopy (GC-MS. The characterization results showed that spesific surface area, average pore radius, and total pore volume of the Z sample decreased after loading of the Ni and Mo metals. Amount of total acid sites of the NiMo/Z catalyst was higher than that of the Z sample. The activity of NiMo/Z catalyst decreased after several continously runs. Its regeneration produced the NiMo/Z reg catalyst with similar activity and selectivity to the fresh catalyst (NiMo/Z. The activity of catalysts at the optimum condition followed the order of NiMo/Z reg>NiMo/Z>Z (conversion of hydrocarbon C>12 and NiMo/Z reg>NiMo/Z>Z (total yield of gasoline fraction. The selectivity of catalysts for C7-C8 product followed the order of Z>NiMo/Z>NiMo/Z reg. Keywords: activity, polyprophylene, catalyst, gasoline fraction.

  2. M3C (M: Fe, Co, Ni) Nanocrystals Encased in Graphene Nanoribbons: An Active and Stable Bifunctional Electrocatalyst for Oxygen Reduction and Hydrogen Evolution Reactions.

    Science.gov (United States)

    Fan, Xiujun; Peng, Zhiwei; Ye, Ruquan; Zhou, Haiqing; Guo, Xia

    2015-07-28

    Transition metal carbide nanocrystalline M3C (M: Fe, Co, Ni) encapsulated in graphitic shells supported with vertically aligned graphene nanoribbons (VA-GNRs) are synthesized through a hot filament chemical vapor deposition (HF-CVD) method. The process is based on the direct reaction between iron group metals (Fe, Co, Ni) and carbon source, which are facilely get high purity carbide nanocrystals (NCs) and avoid any other impurity at relatively low temperature. The M3C-GNRs exhibit superior enhanced electrocatalystic activity for oxygen reduction reaction (ORR), including low Tafel slope (39, 41, and 45 mV dec(-1) for Fe3C-GNRs, Co3C-GNRs, and Ni3C-GNRs, respectively), positive onset potential (∼0.8 V), high electron transfer number (∼4), and long-term stability (no obvious drop after 20 000 s test). The M3C-GNRs catalyst also exhibits remarkable hydrogen evolution reaction (HER) activity with a large cathodic current density of 166.6, 79.6, and 116.4 mA cm(-2) at an overpotential of 200 mV, low onset overpotential of 32, 41, and 35 mV, small Tafel slope of 46, 57, and 54 mV dec(-1) for Fe3C-GNRs, Co3C-GNRs, and Ni3C-GNRs, respectively, as well as an excellent stability in acidic media.

  3. Ni hollow spheres as catalysts for methanol and ethanol electrooxidation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Changwei [Department of Chemistry and Institute of Nanochemistry, Jinan University, Guangzhou 510632 (China); School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Hu, Yonghong; Rong, Jianhua; Liu, Yingliang [Department of Chemistry and Institute of Nanochemistry, Jinan University, Guangzhou 510632 (China); Jiang, San Ping [School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2007-08-15

    In this paper, we successfully synthesized Ni hollow spheres consisting of needle-like nickel particles by using silica spheres as template with gold nanoparticles seeding method. The Ni hollow spheres are applied to methanol and ethanol electrooxidation in alkaline media. The results show that the Ni hollow spheres give a very high activity for alcohol electrooxidation at a very low nickel loading of 0.10 mg cm{sup -2}. The current on Ni hollow spheres is much higher than that on Ni particles. The onset potential and peak potential on Ni hollow spheres are more negative than that on Ni particles for methanol and ethanol electrooxidation. The Ni hollow spheres may be of great potential in alcohol sensor and direct alcohol fuel cells. (author)

  4. Nano-structureal and nano-chemical analysis of Ni-based alloy/low alloy steel dissimilar metal weld interfaces

    International Nuclear Information System (INIS)

    Choi, Kyoung Joon; Shin, Sang Hun; Kim, Jong Jin; Jung, Ju Ang; Kim, Ji Hyun

    2012-01-01

    The dissimilar metal joints welded between Ni-based alloy, Alloy 690 and low alloy steel, A533 Gr. B with Alloy 152 filler metal were characterized by using optical microscope, scanning electron microscope, transmission electron microscope, secondary ion mass spectrometry and 3-dimensional atom probe tomography. It was found that in the weld root region, the weld was divided into several regions including unmixed zone in Ni-base alloy, fusion boundary, and heat-affected zone in the low alloy steel. The result of nanostructural and nanochemical analyses in this study showed the non-homogeneous distribution of elements with higher Fe but lower Mn, Ni and Cr in A533 Gr. B compared with Alloy 152, and the precipitation of carbides near the fusion boundary.

  5. Nano-structureal and nano-chemical analysis of Ni-based alloy/low alloy steel dissimilar metal weld interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Kyoung Joon; Shin, Sang Hun; Kim, Jong Jin; Jung, Ju Ang; Kim, Ji Hyun [Interdisciplinary School of Green Energy, Ulsan National Institute of Science and Technology (UNIST), Ulsan (Korea, Republic of)

    2012-06-15

    The dissimilar metal joints welded between Ni-based alloy, Alloy 690 and low alloy steel, A533 Gr. B with Alloy 152 filler metal were characterized by using optical microscope, scanning electron microscope, transmission electron microscope, secondary ion mass spectrometry and 3-dimensional atom probe tomography. It was found that in the weld root region, the weld was divided into several regions including unmixed zone in Ni-base alloy, fusion boundary, and heat-affected zone in the low alloy steel. The result of nanostructural and nanochemical analyses in this study showed the non-homogeneous distribution of elements with higher Fe but lower Mn, Ni and Cr in A533 Gr. B compared with Alloy 152, and the precipitation of carbides near the fusion boundary.

  6. Study of the electroplated of Ni for betavoltaic battery using PN junction without seed layer

    Energy Technology Data Exchange (ETDEWEB)

    Uhm, Young Rang; Kim, Jong Bum; Son, Kwang Jae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Cho, Byoung Gun [Electronics and Telecommunications Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The mechanism of a nuclear battery is same as the P.N junction diode for solar cell application. The photovoltaic is operated by converting photons into electrical energy in the junction. In a betavoltaic battery, beta particles are collected and converted into electrical energy with a similar principle as a photovoltaic. If a radioisotope (RI) with a long half-life (over 100 years) is used, the lifetime of the power source is extended to as long as the half-life time of the RI. Hence, the power sources we describe could extend a system's operating life by several decades or even a century, during which time the system can gain learned behavior without worrying about the power turning off. The beta spectrum of {sup 63}Ni is below the radiation damage threshold (approximately 200 keV for Si) of semiconductors such as Si and SiC. Beta particles of 63Ni were deposited by electroplating on the Ni-foil substrate and attached on the trench P-N absorber with a spacing of 50 μm. The optimum total thickness of the 63Ni layer was determined to be about 2 μm, when regarding the minimum self-shielding effect of the beta-ray (β-ray). The optimum condition of the electroplating {sup 63}Ni was determined at current density of 20 mA/cm{sup 2}.

  7. Study of the electroplated of Ni for betavoltaic battery using PN junction without seed layer

    International Nuclear Information System (INIS)

    Uhm, Young Rang; Kim, Jong Bum; Son, Kwang Jae; Cho, Byoung Gun

    2015-01-01

    The mechanism of a nuclear battery is same as the P.N junction diode for solar cell application. The photovoltaic is operated by converting photons into electrical energy in the junction. In a betavoltaic battery, beta particles are collected and converted into electrical energy with a similar principle as a photovoltaic. If a radioisotope (RI) with a long half-life (over 100 years) is used, the lifetime of the power source is extended to as long as the half-life time of the RI. Hence, the power sources we describe could extend a system's operating life by several decades or even a century, during which time the system can gain learned behavior without worrying about the power turning off. The beta spectrum of 63 Ni is below the radiation damage threshold (approximately 200 keV for Si) of semiconductors such as Si and SiC. Beta particles of 63Ni were deposited by electroplating on the Ni-foil substrate and attached on the trench P-N absorber with a spacing of 50 μm. The optimum total thickness of the 63Ni layer was determined to be about 2 μm, when regarding the minimum self-shielding effect of the beta-ray (β-ray). The optimum condition of the electroplating 63 Ni was determined at current density of 20 mA/cm 2

  8. Diffusion of Ni, Ga, and As in the surface layer of GaAs and characteristics of the Ni/GaAs contact

    International Nuclear Information System (INIS)

    Uskov, V.A.; Fedotov, A.B.; Erofeeva, E.A.; Rodionov, A.I.; Dzhumakulov, D.T.

    1987-01-01

    The authors investigate the low-temperature codiffusion of Ni, Ga, and As in the surface layer of gallium arsenide and study its effect on the current-voltage characteristics of a Ni/GaAs rectifier contact. The concentration distribution of atoms in the function layer of a Ni-GaAs system was investigated by the methods of layerwise radiometric and neutron-activation analyses. It was found that interdiffusion of components takes place in the Ni-GaAs system in an elastic stress field, generated by the differences in the lattice parameters and thermal-expansion coefficients of Ni, GaAs, and the intermetallic compound which form. The form and parameters of the current-voltage characteristics of a Ni/GaAs contact are determined by the phase composition and the structure of the junction layer

  9. Effect of Ni on the characteristics and hydrogenation activity of sulfide Mo/γ-Al2O3

    International Nuclear Information System (INIS)

    Schachtl, E.; Wuttke, E.; Gutierrez, O.Y.; Lercher, J.A.

    2012-01-01

    The hydrogenation of phenanthrene was explored on sulfide Mo/γ-Al 2 O 3 catalysts promoted with increasing concentrations of Ni. The characterization of the materials was done by N 2 -physisorption, X-ray diffraction, transmission electron microscopy, temperature programmed sulfidation and NO adsorption experiments. Increasing loading of Ni improves the dispersion of MoS 2 species; however, at Ni/(Mo+Ni) molar ratio higher than 0.5, segregation of Ni-sulfides is observed. The presence of Ni also facilitates the sulfidation of oxidic catalyst precursors by lowering the reduction temperature of Mo species. In the sulfide catalysts, Ni changes the structure of MoS 2 leading to shorter slabs with higher stacking degree than on Mo/γ-Al 2 O 3 , and increases the concentration of coordinatively unsaturated sites. The kinetic results (increased hydrogenation rate and changed reaction network in the presence of Ni) suggest that a highly active kind of active site is created by Ni promotion. (orig.)

  10. Maternal hemochromatosis gene H63D single-nucleotide polymorphism and lead levels of placental tissue, maternal and umbilical cord blood

    Energy Technology Data Exchange (ETDEWEB)

    Kayaalti, Zeliha, E-mail: kayaalti@ankara.edu.tr [Ankara University, Institute of Forensic Sciences, Ankara (Turkey); Kaya-Akyüzlü, Dilek [Ankara University, Institute of Forensic Sciences, Ankara (Turkey); Söylemez, Esma [Ankara University, Institute of Forensic Sciences, Ankara (Turkey); Middle Black Sea Passage Generation of Agricultural Research Station Director, Tokat (Turkey); Söylemezoğlu, Tülin [Ankara University, Institute of Forensic Sciences, Ankara (Turkey)

    2015-07-15

    Human hemochromatosis protein (HFE), a major histocompatibility complex class I-like integral membrane protein, participates in the down regulation of intestinal iron absorption by binding to transferrin receptor (TR). HFE competes with transferrin-bound iron for the TR and thus reduces uptake of iron into cells. On the other hand, a lack of HFE increases the intestinal absorption of iron similarly to iron deficiency associated with increasing in absorption and deposition of lead. During pregnancy, placenta cannot prevent transfer lead to the fetus; even low-level lead poisoning causes neurodevelopmental toxicity in children. The aim of this study was to determine the association between the maternal HFE H63D single-nucleotide polymorphism and lead levels in placental tissue, maternal blood and umbilical cord bloods. The study population comprised 93 mother–placenta pairs. Venous blood from mother was collected to investigate lead levels and HFE polymorphism that was detected by standard PCR–RFLP technique. Cord bloods and placentas were collected for lead levels which were analyzed by dual atomic absorption spectrometer system. The HFE H63D genotype frequencies of mothers were found as 75.3% homozygote typical (HH), 23.6% heterozygote (HD) and 1.1% homozygote atypical (DD). Our study results showed that the placental tissue, umbilical cord and maternal blood lead levels of mothers with HD+DD genotypes were significantly higher than those with HH genotype (p<0.05). The present study indicated for the first time that mothers with H63D gene variants have higher lead levels of their newborn's placentas and umbilical cord bloods. - Highlights: • Mothers with H63D gene variants have higher lead levels of their newborn's umbilical cord blood. • Unborn child of women with HD+DD genotypes may be at increased risk of internal exposure to lead. • Maternal HFE status may have an effect on increased placenta, maternal and cord blood lead levels.

  11. Maternal hemochromatosis gene H63D single-nucleotide polymorphism and lead levels of placental tissue, maternal and umbilical cord blood

    International Nuclear Information System (INIS)

    Kayaalti, Zeliha; Kaya-Akyüzlü, Dilek; Söylemez, Esma; Söylemezoğlu, Tülin

    2015-01-01

    Human hemochromatosis protein (HFE), a major histocompatibility complex class I-like integral membrane protein, participates in the down regulation of intestinal iron absorption by binding to transferrin receptor (TR). HFE competes with transferrin-bound iron for the TR and thus reduces uptake of iron into cells. On the other hand, a lack of HFE increases the intestinal absorption of iron similarly to iron deficiency associated with increasing in absorption and deposition of lead. During pregnancy, placenta cannot prevent transfer lead to the fetus; even low-level lead poisoning causes neurodevelopmental toxicity in children. The aim of this study was to determine the association between the maternal HFE H63D single-nucleotide polymorphism and lead levels in placental tissue, maternal blood and umbilical cord bloods. The study population comprised 93 mother–placenta pairs. Venous blood from mother was collected to investigate lead levels and HFE polymorphism that was detected by standard PCR–RFLP technique. Cord bloods and placentas were collected for lead levels which were analyzed by dual atomic absorption spectrometer system. The HFE H63D genotype frequencies of mothers were found as 75.3% homozygote typical (HH), 23.6% heterozygote (HD) and 1.1% homozygote atypical (DD). Our study results showed that the placental tissue, umbilical cord and maternal blood lead levels of mothers with HD+DD genotypes were significantly higher than those with HH genotype (p<0.05). The present study indicated for the first time that mothers with H63D gene variants have higher lead levels of their newborn's placentas and umbilical cord bloods. - Highlights: • Mothers with H63D gene variants have higher lead levels of their newborn's umbilical cord blood. • Unborn child of women with HD+DD genotypes may be at increased risk of internal exposure to lead. • Maternal HFE status may have an effect on increased placenta, maternal and cord blood lead levels.

  12. Structure and properties of nitrided surface layer produced on NiTi shape memory alloy by low temperature plasma nitriding

    International Nuclear Information System (INIS)

    Czarnowska, Elżbieta; Borowski, Tomasz; Sowińska, Agnieszka; Lelątko, Józef; Oleksiak, Justyna; Kamiński, Janusz; Tarnowski, Michał; Wierzchoń, Tadeusz

    2015-01-01

    Highlights: • Low temperature plasma nitriding process of NiTi shape memory alloy is presented. • The possibility of treatment details of sophisticated shape. • TiN surface layer has diffusive character. • TiN surface layer increases corrosion resistance of NiTi alloy. • Produced TiN layer modify the biological properties of NiTi alloy. - Abstract: NiTi shape memory alloys are used for bone and cardiological implants. However, on account of the metallosis effect, i.e. the release of the alloy elements into surrounding tissues, they are subjected to various surface treatment processes in order to improve their corrosion resistance and biocompatibility without influencing the required shape memory properties. In this paper, the microstructure, topography and morphology of TiN surface layer on NiTi alloy, and corrosion resistance, both before and after nitriding in low-temperature plasma at 290 °C, are presented. Examinations with the use of the potentiodynamic and electrochemical impedance spectroscopy methods were carried out and show an increase of corrosion resistance in Ringer's solution after glow-discharge nitriding. This surface titanium nitride layer also improved the adhesion of platelets and the proliferation of osteoblasts, which was investigated in in vitro experiments with human cells. Experimental data revealed that nitriding NiTi shape memory alloy under low-temperature plasma improves its properties for bone implant applications

  13. Structure and properties of nitrided surface layer produced on NiTi shape memory alloy by low temperature plasma nitriding

    Energy Technology Data Exchange (ETDEWEB)

    Czarnowska, Elżbieta [Children' s Memorial Health Institute, Pathology Department, Al. Dzieci Polskich 20, 04-730 Warsaw (Poland); Borowski, Tomasz [Warsaw University of Technology, Faculty of Materials Science and Engineering, Wołoska 141, 02-507 Warsaw (Poland); Sowińska, Agnieszka [Children' s Memorial Health Institute, Pathology Department, Al. Dzieci Polskich 20, 04-730 Warsaw (Poland); Lelątko, Józef [Silesia University, Faculty of Computer Science and Materials Science, 75 Pułku Piechoty 1A, 41-500 Chorzów (Poland); Oleksiak, Justyna; Kamiński, Janusz; Tarnowski, Michał [Warsaw University of Technology, Faculty of Materials Science and Engineering, Wołoska 141, 02-507 Warsaw (Poland); Wierzchoń, Tadeusz, E-mail: twierz@inmat.pw.edu.pl [Warsaw University of Technology, Faculty of Materials Science and Engineering, Wołoska 141, 02-507 Warsaw (Poland)

    2015-04-15

    Highlights: • Low temperature plasma nitriding process of NiTi shape memory alloy is presented. • The possibility of treatment details of sophisticated shape. • TiN surface layer has diffusive character. • TiN surface layer increases corrosion resistance of NiTi alloy. • Produced TiN layer modify the biological properties of NiTi alloy. - Abstract: NiTi shape memory alloys are used for bone and cardiological implants. However, on account of the metallosis effect, i.e. the release of the alloy elements into surrounding tissues, they are subjected to various surface treatment processes in order to improve their corrosion resistance and biocompatibility without influencing the required shape memory properties. In this paper, the microstructure, topography and morphology of TiN surface layer on NiTi alloy, and corrosion resistance, both before and after nitriding in low-temperature plasma at 290 °C, are presented. Examinations with the use of the potentiodynamic and electrochemical impedance spectroscopy methods were carried out and show an increase of corrosion resistance in Ringer's solution after glow-discharge nitriding. This surface titanium nitride layer also improved the adhesion of platelets and the proliferation of osteoblasts, which was investigated in in vitro experiments with human cells. Experimental data revealed that nitriding NiTi shape memory alloy under low-temperature plasma improves its properties for bone implant applications.

  14. Sensitive Nonenzymatic Electrochemical Glucose Detection Based on Hollow Porous NiO

    Science.gov (United States)

    He, Gege; Tian, Liangliang; Cai, Yanhua; Wu, Shenping; Su, Yongyao; Yan, Hengqing; Pu, Wanrong; Zhang, Jinkun; Li, Lu

    2018-01-01

    Transition metal oxides (TMOs) have attracted extensive research attentions as promising electrocatalytic materials. Despite low cost and high stability, the electrocatalytic activity of TMOs still cannot satisfy the requirements of applications. Inspired by kinetics, the design of hollow porous structure is considered as a promising strategy to achieve superior electrocatalytic performance. In this work, cubic NiO hollow porous architecture (NiO HPA) was constructed through coordinating etching and precipitating (CEP) principle followed by post calcination. Being employed to detect glucose, NiO HPA electrode exhibits outstanding electrocatalytic activity in terms of high sensitivity (1323 μA mM-1 cm-2) and low detection limit (0.32 μM). The excellent electrocatalytic activity can be ascribed to large specific surface area (SSA), ordered diffusion channels, and accelerated electron transfer rate derived from the unique hollow porous features. The results demonstrate that the NiO HPA could have practical applications in the design of nonenzymatic glucose sensors. The construction of hollow porous architecture provides an effective nanoengineering strategy for high-performance electrocatalysts.

  15. Comparison of reduction agents in the synthesis of infinite-layer LaNiO2 films

    International Nuclear Information System (INIS)

    Ikeda, Ai; Manabe, Takaaki; Naito, Michio

    2014-01-01

    Highlights: • Reduction agents were compared from a viewpoint of the facility for topotactic reduction of LaNiO 3 to LaNiO 2 films. • TiH 2 and CaH 2 yielded infinite-layer LaNiO 2 with low and metallic resistivity. • H 2 released from metal hydrides plays a dominant role in the topotactic reduction. - Abstract: Reduction agents, such as activated carbon, TiH 2 , and CaH 2 , were compared from a viewpoint of the facility for the topotactic reduction of LaNiO 3 to LaNiO 2 films. Activated carbon did not yield infinite-layer LaNiO 2 whereas both of TiH 2 and CaH 2 yielded infinite-layer LaNiO 2 with low resistivity (∼1 mΩ cm at 300 K) as well as metallic behavior down to 70 K. Thermal desorption spectroscopy indicated that H 2 released from metal hydrides plays a dominant role in the topotactic reduction

  16. Metal oxides modified NiO catalysts for oxidative dehydrogenation of ethane to ethylene

    KAUST Repository

    Zhu, Haibo; Dong, Hailin; Laveille, Paco; Saih, Youssef; Caps, Valerie; Basset, Jean-Marie

    2014-01-01

    in contrast to pure NiO. The introduction of group IV, V and VI transition metals into NiO decreases the catalytic activity in ethane ODH. However, the ethylene selectivity is enhanced with the highest level for the Ni-W-O and Ni-Ti-O catalysts. As a result

  17. A possible highly active supported Ni dimer catalyst for O{sub 2} dissociation: A first-principles study

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Shan [College of Physics and Materials Science, Henan Normal University, Xinxiang, Henan 453007 (China); Zhang, Yanxing, E-mail: 2016025@htu.edu.cn [College of Physics and Materials Science, Henan Normal University, Xinxiang, Henan 453007 (China); Zhang, Xilin; Mao, Jianjun [College of Physics and Materials Science, Henan Normal University, Xinxiang, Henan 453007 (China); Yang, Zongxian, E-mail: yzx@henannu.edu.cn [College of Physics and Materials Science, Henan Normal University, Xinxiang, Henan 453007 (China); Collaborative Innovation Center of Nano Functional Materials and Applications, Henan Province (China)

    2017-04-30

    Graphical abstract: The minimum energy paths (MEPs) for the dissociation process of O{sub 2} on the surfaces of bare YSZ (111) and Ni{sub n}/YSZ (111) (n = 1, 2 and 3). - Highlights: • The catalytic activity of supported metal catalysts is closely related to the size of metal particles. • The dissociation of O{sub 2} on the YSZ (111) surface is largely enhanced by the supported Ni cluster. • The supported Ni dimer is predicted to be the smallest Ni cluster needed for efficient O{sub 2} dissociation. • The results would provide an important reference to improve the activity and efficiency of the Ni/YSZ(111) nanocomposite catalysts in cost-effective materials. - Abstract: The adsorption and dissociation of O{sub 2} on the supported small nickel clusters with one-, two-, three-Ni atoms on yttria-stabilized zirconia (YSZ) (111) surfaces, as well as those on the bare YSZ(111) and Ni(111) surfaces are comparatively studied using ab initio density functional theory calculations. It is found that the dissociation of O{sub 2} on the YSZ(111) surface is largely enhanced by the supported Ni dimer, which is predicted to be the smallest Ni cluster needed for efficient O{sub 2} dissociation. The results would provide an important reference to improve the activity and efficiency of the Ni/YSZ(111) nanocomposite catalysts in cost-effective materials.

  18. Explosives vapour identification in ion mobility spectrometry using a tunable laser ionization source: a comparison with conventional 63Ni ionization

    International Nuclear Information System (INIS)

    Clark, A.; Deas, R.M.; Kosmidis, C.; Ledingham, K.W.D.; Marshall, A.; Singhal, R.P.

    1995-01-01

    Laser multiphoton ionization (MPI) is used to produce ions from explosive vapours at atmospheric pressure in air for analysis by ion mobility spectrometry (IMS). In the positive ion mode of detection, NO + ions, generated directly by multiphoton dissociation/ionization of the explosive compounds, show strong variation with laser wavelength. This provides a means of identifying the presence of nitro-containing compounds. Moreover, electrons formed in the MPI of gaseous components in the air carrier stream, primarily O 2 , are transferred via neutral molecular oxygen (O 2 ) to trace explosive vapour, forming negative ions which give rise to characteristic and identifiable ion mobility spectra. Further, negative ion mobility spectra of several explosive vapours are presented using conventional 63 Ni ionization and are compared qualitatively with the laser ionization approach. (author)

  19. Alloyed Ni-Fe nanoparticles as catalysts for NH3 decomposition

    DEFF Research Database (Denmark)

    Simonsen, Søren Bredmose; Chakraborty, Debasish; Chorkendorff, Ib

    2012-01-01

    A rational design approach was used to develop an alloyed Ni-Fe/Al2O3 catalyst for decomposition of ammonia. The dependence of the catalytic activity is tested as a function of the Ni-to-Fe ratio, the type of Ni-Fe alloy phase, the metal loading and the type of oxide support. In the tests with high...... temperatures and a low NH3-to-H2 ratio, the catalytic activity of the best Ni-Fe/Al2O3 catalyst was found to be comparable or even better to that of a more expensive Ru-based catalyst. Small Ni-Fe nanoparticle sizes are crucial for an optimal overall NH3 conversion because of a structural effect favoring...

  20. Effect of Mg substitution on crystal structure and hydrogenation of Ce{sub 2}Ni{sub 7}-type Pr{sub 2}Ni{sub 7}

    Energy Technology Data Exchange (ETDEWEB)

    Iwase, Kenji, E-mail: fbiwase@mx.ibaraki.ac.jp [Department of Materials Science and Engineering, Ibaraki University, 4-12-1 Nakanarusawa, Hitachi 316-8511 (Japan); Mori, Kazuhiro [Research Reactor Institute, Kyoto University, 2-1010 Asashiro-nishi, Kumatori, Sennan, Osaka 590-0494 (Japan); Terashita, Naoyoshi [Japan Metals & Chemicals Co., Ltd., Nishiokitama-gun, Yamagata 999-1351 (Japan); Tashiro, Suguru; Suzuki, Tetsuya [Department of Materials Science and Engineering, Ibaraki University, 4-12-1 Nakanarusawa, Hitachi 316-8511 (Japan)

    2017-03-15

    The effect of Pr being substituted by Mg in Pr{sub 2}Ni{sub 7} with a Ce{sub 2}Ni{sub 7}-type structure was investigated by X-ray diffraction (XRD) and pressure−composition (P−C) isotherm measurements. The maximum hydrogen capacity of Pr{sub 2}Ni{sub 7} reached 1.24 H/M in the first absorption process. However, 0.61 H/M hydrogen remained in the sample after the first desorption and the reversible hydrogen capacity decreased to 0.63 H/M. Severe peak broadening was observed in the XRD profile of Pr{sub 2}Ni{sub 7}H{sub 5.4} after the first P−C isotherm cycle. The metal sublattice of Pr{sub 2}Ni{sub 7}H{sub 5.4} is deformed and changes from the Ce{sub 2}Ni{sub 7}-type structure to a lower symmetry during hydrogenation, with no detection of an amorphous phase. Pr{sub 1.5}Mg{sub 0.5}Ni{sub 7} consists of two phases: 80% Gd{sub 2}Co{sub 7}-type and 20% PuNi{sub 3}-type phases. Mg substitution leads to the relative stability of the Gd{sub 2}Co{sub 7}-type and PuNi{sub 3}-type structures. The Gd{sub 2}Co{sub 7}-type and PuNi{sub 3}-type structures are retained after the P-C isotherm. The reversible hydrogen capacity reached 1.05 H/M. The structural change during the hydrogen absorption−desorption cycle and the hydrogenation characteristics are changed by Mg atoms replacing Pr in the MgZn{sub 2}-type cell. - Graphical abstract: The maximum hydrogen capacity is 1.2 H/M in the first absorption process and the reversible capacity is 0.63 H/M.

  1. The status of siting activities for a low level waste repository in the Philippines

    International Nuclear Information System (INIS)

    Valdezco, E.M.; Visitacion, M.; Palattao, B.; Marcelo, E.A.; Venida, L.L.

    2001-01-01

    The process of site selection for a low level waste repository was initiated in 1976 when the Philippine Government decided to go nuclear and constructed the first Philippine Nuclear Power Plant in the Bataan Peninsula. However, all siting activities were suspended when the nuclear power plant was mothballed and the final decision was made to convert the plant into a combined cycle power plant. In 1995, an inter-agency committee was created under the Nuclear Power Steering Committee and mandated to conduct studies on siting of radioactive waste disposal facilities, and at the same time, perform R and D activities in support of the project. This paper describes the various siting activities carried out to date. (author)

  2. A case of tongue edema associated with radiation-induced ulcer with low level of C1 inhibitor activity

    International Nuclear Information System (INIS)

    Hata, Tsuyoshi; Hosoda, Masaru

    2003-01-01

    A 66-year-old man became aware of sudden swelling of the tongue with swallowing disturbance. He had a medical history of tongue cancer treated by interstitial radiotherapy and had undergone a cytological examination of an ulcer on the right side of the tongue three weeks earlier because of suspected recurrence. The cytological examination result was class I with no malignant findings. Angioneurotic edema, so-called ''Quincke's edema'', associated with radiation-induced ulcer of the tongue, was diagnosed. Tranexamic acid, d-chlorpheniramine maleate, and epinephrine were administered. After six days, the tongue edema had almost disappeared. Laboratory examination revealed a low level of C1 inhibitor activity with normal levels of CH50, C1, C3, and C4 at the time of swelling. Hereditary angioneurotic edema with absence of hereditary trait was suspected based on the sudden edema attack and low level of C1 inhibitor activity. The C1 inhibitor activity returned to normal after disappearance of the tongue edema. (author)

  3. Thermally Stable Ni-rich Austenite Formed Utilizing Multistep Intercritical Heat Treatment in a Low-Carbon 10 Wt Pct Ni Martensitic Steel

    Science.gov (United States)

    Jain, Divya; Isheim, Dieter; Zhang, Xian J.; Ghosh, Gautam; Seidman, David N.

    2017-08-01

    Austenite reversion and its thermal stability attained during the transformation is key to enhanced toughness and blast resistance in transformation-induced-plasticity martensitic steels. We demonstrate that the thermal stability of Ni-stabilized austenite and kinetics of the transformation can be controlled by forming Ni-rich regions in proximity of pre-existing (retained) austenite. Atom probe tomography (APT) in conjunction with thermodynamic and kinetic modeling elucidates the role of Ni-rich regions in enhancing growth kinetics of thermally stable austenite, formed utilizing a multistep intercritical ( Quench- Lamellarization- Tempering (QLT)-type) heat treatment for a low-carbon 10 wt pct Ni steel. Direct evidence of austenite formation is provided by dilatometry, and the volume fraction is quantified by synchrotron X-ray diffraction. The results indicate the growth of nm-thick austenite layers during the second intercritical tempering treatment (T-step) at 863 K (590 °C), with austenite retained from first intercritical treatment (L-step) at 923 K (650 °C) acting as a nucleation template. For the first time, the thermal stability of austenite is quantified with respect to its compositional evolution during the multistep intercritical treatment of these steels. Austenite compositions measured by APT are used in combination with the thermodynamic and kinetic approach formulated by Ghosh and Olson to assess thermal stability and predict the martensite-start temperature. This approach is particularly useful as empirical relations cannot be extrapolated for the highly Ni-enriched austenite investigated in the present study.

  4. ¿Son los niños con sobrepeso menos activos durante los recreos escolares? [Are overweight children less active during school recesses?].

    Directory of Open Access Journals (Sweden)

    Iván López-Fernández

    2017-01-01

    Full Text Available La actividad física diaria realizada por niños con sobrepeso es menor que la realizada por niños con peso normal. El objetivo de esta investigación era conocer si esa diferencia se mantenía también en entornos, como los recreos escolares, en los que todos cuentan con las mismas oportunidades de ser físicamente activos. Participaron 263 alumnos (140 niños, 123 niñas; 39,9% con sobrepeso de seis a ocho años de edad. La actividad física durante los recreos fue evaluada a través de podómetros. No se encontraron diferencias significativas entre la actividad física desarrollada en los recreos por niños con peso normal y con sobrepeso (p = 0,586. El fomento de entornos, como los recreos escolares, podría contribuir a reducir la diferencia en los niveles de actividad física diaria entre niños con sobrepeso y con peso normal. Abstract Daily physical activity performed by overweight children is lower than daily physical activity performed by normal weight children. The aim of this research was to know if this difference was also maintained in environments, as school recesses, where all children have equal opportunities to be physically active. A total of 263 students (140 boys, 123 girls; 39.9% overweight from six to eight years old participated in this study. Pedometers assessed physical activity during recesses. No significant differences were found between physical activity in recess for normal weight and overweight children (p = 0.586. Promoting environments, such as recesses, could help reduce the difference in levels of daily physical activity among overweight and normal weight children.

  5. Giant magnetoimpedance effect in sputtered single layered NiFe film and meander NiFe/Cu/NiFe film

    International Nuclear Information System (INIS)

    Chen, L.; Zhou, Y.; Lei, C.; Zhou, Z.M.; Ding, W.

    2010-01-01

    Giant magnetoimpedance (GMI) effect on NiFe thin film is very promising due to its application in developing the magnetic field sensors with highly sensitivity and low cost. In this paper, the single layered NiFe thin film and NiFe/Cu/NiFe thin film with a meander structure are prepared by the MEMS technology. The influences of sputtering parameters, film structure and conductor layer width on GMI effect in NiFe single layer and meander NiFe/Cu/NiFe film are investigated. Maximum of the GMI ratio in single layer and sandwich film is 5% and 64%, respectively. The results obtained are useful for developing the high-performance magnetic sensors based on NiFe thin film.

  6. Low activation diagnostic equipment design studies

    International Nuclear Information System (INIS)

    Hopkins, G.R.; Cheng, E.T.; Fisher, R.K.

    1985-01-01

    The low activation fusion concept has been applied to the diagnostic equipment in a fusion reactor. The components where fabrication from low activation materials is feasible have been identified. Other systems where higher activation elements are required can have their activation reduced by design approaches which include shielding and operation only in low flux regions of the reactor. Some components will not operate in a high flux so activation is not a major concern. This low activation diagnostic equipment study completes a series of low activation studies where all the components in a fusion power reactor have now been evaluated. It is concluded that a completely low activation fusion reactor is feasible with all components meeting the functional requirements. This provides an environmentally benign energy source with a high confidence level in meeting safety criteria in operation, maintenance and waste disposal

  7. Temperature dependent mechanical properties and thermal activation plasticity of nanocrystalline and coarse grained Ni-18.75 at.% Fe alloy

    International Nuclear Information System (INIS)

    Tabachnikova, E D; Podolskiy, A V; Smirnov, S N; Psaruk, I A; Liao, P K

    2014-01-01

    Mechanical properties of Ni-18.75 at.% Fe in coarse grained (average grain size 15 gm) and nanocrystalline (average grain size 22 nm) states were studied in uniaxial compression in the temperature range 4.2-350 K. Temperature dependences of the flow stress, strain rate sensitivity and activation volume of plastic deformation were measured. The thermal activation analysis of the experimental data has been fulfilled for the the plastic deformation value of 2 %. It was shown that plastic deformation in temperature range from 35 to 350 K in both studied structural states has the thermally activated type. Comparative analysis of low temperature thermal activation plastic deformation was carried out for the alloy in coarse grained and nanocrystalline states. Empirical estimates of parameters of the dislocation interaction with local barriers and internal stress value estimates were obtained for the both studied structural states. Analysis of the results indicates that different mechanisms control the thermal activation plasticity of the Ni-18.75 at.% Fe alloy in coarse grained and nanocrystalline states. Possible mechanisms, which control plactisity of the studied states, are disscussed

  8. Amino-terminal residues of ΔNp63, mutated in ectodermal dysplasia, are required for its transcriptional activity.

    Science.gov (United States)

    Lena, Anna Maria; Duca, Sara; Novelli, Flavia; Melino, Sonia; Annicchiarico-Petruzzelli, Margherita; Melino, Gerry; Candi, Eleonora

    2015-11-13

    p63, a member of the p53 family, is a crucial transcription factor for epithelial development and skin homeostasis. Heterozygous mutations in TP63 gene have been associated with human ectodermal dysplasia disorders. Most of these TP63 mutations are missense mutations causing amino acidic substitutions at p63 DNA binding or SAM domains that reduce or abolish the transcriptional activity of mutants p63. A significant number of mutants, however, resides in part of the p63 protein that apparently do not affect DNA binding and/or transcriptional activity, such as the N-terminal domain. Here, we characterize five p63 mutations at the 5' end of TP63 gene aiming to understand the pathogenesis of the diseases and to uncover the role of ΔNp63α N-terminus residues in determining its transactivation potential. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Non-Newtonian plastic flow of a Ni-Si-B metallic glass at low stresses

    International Nuclear Information System (INIS)

    Csach, K.; Fursova, Y.V.; Khonik, V.A.; Ocelik, V.

    1998-01-01

    The problem of the rheological behavior of metallic glasses (MGs) is quite important both from theoretical and practical viewpoints. Early experiments carried out on MGs at temperatures T > 300 K using low shear stress levels revealed plastic flow to be Newtonian while measurements at relative high shear stresses (more than 200 to 400 MPa, depending on temperature, thermal prehistory of samples and chemical composition) indicated a non-linear behavior with 1 < m < 12. Numerous investigations performed later both on as-cast and relaxed MGs of various chemical compositions using a number of testing methods (tensile creep, tensile and bend stress relaxation) showed that a transition from Newtonian behavior at low stresses to a non-linear flow at high stresses was observed. At present, such a situation is considered to be generally accepted. The authors performed precise creep measurements of a Ni-Si-B metallic glass. The results obtained indicate that plastic flow in this case at low tensile stress (12 le σ le 307 MPa) is clearly non-Newtonian and, consequently, the viscosity is stress dependent

  10. Correlation analysis of Standardized Precipitation Index (SPI) for the water debit and level of the Cisadane River during El Niño and La Niña years

    Science.gov (United States)

    Khoir, A. N.; Rohmah, M.; Nuryadi

    2018-03-01

    Hydrometeorological factor causes most disaster in Indonesia, and two of them are drought and flood. This study aims to correlate Standardized Precipitation Index (SPI) 3-monthly to water debit and water level in the Cisadane River. The monthly rainfall data from Serpong and Pasar Baru rain station from 2009 to 2011 when moderate El Niño and moderate La Niña happened. The correlation analysis between debit and water level to SPI 3-monthly used rain post of Serpong to represent the condition of the upstream area and rain post of Pasar Baru to represent the condition of the downstream area. The results showed that during La Niña year, the rainfall on the upstream area of the Cisadane River influenced the increase and the decrease in water debit and water level. Meanwhile, the rainfall on the downstream area of the river has an opposite effect on the increase and the decrease of debit and water level of the Pasar Baru. On the upstream area, the correlation between rainfall and water debit is 0.8, and the correlation between rainfall and water level is also 0.8. During El Niño year, the correlation was less than 0.5.

  11. Study on treating of low-level radioactive reactor wastewater by combined membrane process (UF-RO)

    International Nuclear Information System (INIS)

    Lu Yunyun; Cao Qiru; Chen Yunming; Huang Lijuan; Bai Xiaofeng; Li Bing; Feng Liang

    2013-01-01

    According to the characteristics of radionuclide exists in the low-level radioactive reactor waste water from HFETR, we use a new combined membrane process separation technology to study the efficient treating of low-lever radioactive reactor wastewater. First, the prepared the simulated wastewater contained Cs + , Sr 2+ , CO 2+ , Ni 2+ , and Fe 3+ . Then, we sequentially investigated the pressure, ion concentration, pH value and EDTA, which have effects on the desalination rate of membrane processing metal ions in wastewater. The results show that: in the condition of pH = 7, and added 0.15 mol/L EDTA, the simulated wastewater separated by UF-RO, desalination rates of Cs + , Sr 2+ , CO 2+ , Ni 2+ and Fe 3+ are all above 95%; In the subsequent trials, adding 0.15 mol/L EDTA into the radioactive residuary solution, and then treating by UF-RO-RO, the decontamination efficiency can reach 95.7%. (authors)

  12. Solution-processed flexible NiO resistive random access memory device

    Science.gov (United States)

    Kim, Soo-Jung; Lee, Heon; Hong, Sung-Hoon

    2018-04-01

    Non-volatile memories (NVMs) using nanocrystals (NCs) as active materials can be applied to soft electronic devices requiring a low-temperature process because NCs do not require a heat treatment process for crystallization. In addition, memory devices can be implemented simply by using a patterning technique using a solution process. In this study, a flexible NiO ReRAM device was fabricated using a simple NC patterning method that controls the capillary force and dewetting of a NiO NC solution at low temperature. The switching behavior of a NiO NC based memory was clearly observed by conductive atomic force microscopy (c-AFM).

  13. A preliminary evaluation of alternatives for disposal of INEL low-level waste and low-level mixed waste

    International Nuclear Information System (INIS)

    Smith, T.H.; Roesener, W.S.; Jorgenson-Waters, M.J.

    1993-07-01

    The Mixed and Low-Level Waste Disposal Facility (MLLWDF) project was established in 1992 by the US Department of Energy Idaho Operations Office to provide enhanced disposal capabilities for Idaho National Engineering Laboratory (INEL) low-level mixed waste and low-level waste. This Preliminary Evaluation of Alternatives for Disposal of INEL Low-Level Waste and Low-Level Mixed Waste identifies and evaluates-on a preliminary, overview basis-the alternatives for disposal of that waste. Five disposal alternatives, ranging from of no-action'' to constructing and operating the MLLWDF, are identified and evaluated. Several subalternatives are formulated within the MLLWDF alternative. The subalternatives involve various disposal technologies as well as various scenarios related to the waste volumes and waste forms to be received for disposal. The evaluations include qualitative comparisons of the projected isolation performance for each alternative, and facility, health and safety, environmental, institutional, schedule, and rough order-of-magnitude life-cycle cost comparisons. The performance of each alternative is evaluated against lists of ''musts'' and ''wants.'' Also included is a discussion of other key considerations for decisionmaking. The analysis of results indicated further study is necessary to obtain the best estimate of long-term future waste volume and characteristics from the INEL Environmental Restoration activities and the expanded INEL Decontamination and Decommissioning Program

  14. Ni3Si2 nanowires grown in situ on Ni foam for high-performance supercapacitors

    Science.gov (United States)

    Jiang, Yizhe; Li, Zhihui; Li, Beibei; Zhang, Jinying; Niu, Chunming

    2016-07-01

    Ni3Si2 nanowires and nanoawls have grown in situ on the surface of Ni foams by a controlled low pressure chemical vapor deposition process. Structural characterization shows that the individual Ni3Si2 nanowire is single crystal covered with a thin layer (1-2 nm) of SiO2 with a diameter of ∼20-30 nm and length of ten's micrometers. Individual nanoawl with a circular cone shape is polycrystalline. Both Ni3Si2 nanowire and nanoawl samples are evaluated as potential electrode materials for supercapacitors. The nanowire electrode delivers a very high specific capacitance and excellent rate capability. A specific capacitance of 760 F g-1 is measured at current density of 0.5 A g-1, which decreases to 518 F g-1 when the current density increases to 10 A g-1. The capacitance is dominated by pseudocapacitance with a mechanism similar to that of NiO or Ni(OH)2 widely studied in the literature. An asymmetric supercapacitor fabricated by pairing Ni3Si2 nanowire electrode with an activated carbon electrode exhibits energy densities of 17.5 Wh kg-1 and 8.8 Wh kg-1 at power densites of 301 W kg-1 and 3000 W kg-1.

  15. Effect of Ni doping on structural and optical properties of Zn{sub 1−x}Ni{sub x}O nanopowder synthesized via low cost sono-chemical method

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Budhendra, E-mail: bksingh@ua.pt [TEMA-NRD, Mechanical Engineering Department, Aveiro Institute of Nanotechnology (AIN), University of Aveiro, 3810-193 Aveiro (Portugal); Kaushal, Ajay, E-mail: ajay.kaushal@ua.pt [Department of Ceramic and Glass Engineering, CICECO, University of Aveiro, 3810-193 Aveiro (Portugal); Bdikin, Igor [TEMA-NRD, Mechanical Engineering Department, Aveiro Institute of Nanotechnology (AIN), University of Aveiro, 3810-193 Aveiro (Portugal); Venkata Saravanan, K. [Department of Physics, School of Basic and Applied Sciences, Central University of Tamil Nadu, Thiruvarur 610101 (India); Ferreira, J.M.F. [Department of Ceramic and Glass Engineering, CICECO, University of Aveiro, 3810-193 Aveiro (Portugal)

    2015-10-15

    Highlights: • Pure and Ni doped ZnO nanopowders were synthesized by low cost sonochemical method. • The optical properties of Zn{sub 1−x}Ni{sub x}O nanopowders can be tuned by varying Ni content. • The results reveal the solubility limit of Ni into ZnO matrix as below 8%. - Abstract: Zn{sub 1−x}Ni{sub x}O nanopowders with different Ni contents of x = 0.0, 0.04 and 0.08 were synthesized via cost effective sonochemical reaction method. X-ray diffraction (XRD) pattern reveals pure wurtzite phase of prepared nanostructures with no additional impurity peaks. The morphology and dimensions of nanoparticles were investigated using scanning electron microscope (SEM). A sharp and strong peak for first order optical mode for wurtzite zinc oxide (ZnO) structure was observed at ∼438 cm{sup −1} in Raman spectra. The calculated optical band gap (E{sub g}) from UV–vis transmission data was found to decrease with increase in Ni content. The observed red shift in E{sub g} with increasing Ni content in ZnO nanopowders were in agreement with band gap behaviours found in their photoluminescence (PL) spectra. The synthesised ZnO nanopowders with controlled band gap on Ni doping reveals their potential for use in various electronic and optical device applications. The results were discussed in detail.

  16. Application of nuclear activation analysis (NAA) and low-level gamma counting to determine the radionuclide and trace element pollutant releases from coal-fired power plants in Vietnam

    International Nuclear Information System (INIS)

    Vanduong, P.; Thanh, V.T.; Dien, P.Q.; Binh, N.T.

    1995-01-01

    Results are reported of the application of NAA using research reactors TRIGA II in Dalat, Vietnam, and Vienna, Austria (with pyrolysis separation for Hg, Se, and As before irradiation), to determine As, Cd, Cu, Hg, Ni, Co, Pb, Sn and Zn. Low-level gamma counting was used to measure Ra-226, Th-228 and K-40, released from coal-fired power plants in Vietnam. Results showed that: (1) the content of the air pollutants in the vicinity of the operating power plants (in 1991, the Phalai plant produced 1700 million kWh, and the Ninhbinh plant 100 million kWh) depends on the coal combustion which is used for their applied operation technology, both plants used Quangninh anthracite as fuel. The content of trace elements pollutants (TEP) in the environment of the Ninhbinh plant is higher than in the Phalai plant. (2) In the vicinity of both plants, rain water is highly polluted by trace elements such as As, Cu, Pb, Hg, Ni, Co, Cd, Se, U, Th and sulphuric acid. Therefore, this kind of water is not acceptable for human consumption. (3) The algae growing in the waterfield in the vicinity of the power plants can be used to monitor TEP. Four NAA methods, in combination with low-level gamma counting and AAS, can be successfully used to monitor TEP released from power plants

  17. Effect of low cost iron oxide with Si additive on structural properties of Ni-Zn ferrite

    International Nuclear Information System (INIS)

    Ghazanfar, U.

    2010-01-01

    Mixed Ni-Zn ferrites (x = 0.66, 0.77, 0.88, 0.99) were prepared by double sintering ceramic method using locally available low cost Fe/sub 2/O/sub 3/ with 0.5% (by wt) of Si additive. The chemical phase analysis, carried out by X-ray powder diffraction method, confirms the major phase of Ni-Zn ferrite. Study of the effect of composition on structural properties of ferrite system revealed a decreasing trend of lattice parameters with increasing Ni content. X-ray density and mass density increase with increasing Ni content, which in turn decreases the porosity due to successive presence of Si in Fe/sub 2/O/sub 3/. This decrease in porosity along with chemical homogeneities, distribution of phases and grain formation were also observed in scanning electron micrographs. (author)

  18. Management of low level waste generated from ISER

    International Nuclear Information System (INIS)

    Mizushina, Tomoyuki

    1987-01-01

    Low level wastes are generated during nuclear power plant operation. In the case of ISER, low level wastes from the reactor are basically the same as of existing light water reactors. Various low level wastes, including solid, liquid and gaseous, are listed and discussed. In normal operation, high-activity wastes are not subjected to any treatment. For contaminated equipment or reactor parts, it may be desirable to transfer most of the activity to liquid phase through an appropriate decontamination procedure. Highly active solid wastes are usually fixed in a solid form through incorporation into either concrete or asphalt as containment material. Decantation and filtration treatments are usually sufficient before dilution and release of liquid wastes into the environment. Except for ordinary gas filtration, there in normally no other treatment. Under certain circumstances, however, it may be important to apply the decay storage before release to the atmosphere. In accidental circumstances, specific filtration is recommended or even sometimes needed. There are some alternatives for storage and-or disposal of low level wastes. In many cases, shallow land burial is chosen as a realistic method for storage and-or disposal of solid waste. In chosing a disposal method, the radiation dose rate from solid wastes or the specific activity should be taken into account. Boric acid is a retarder for cement setting. This effect of boric acid is inhibited by adding a complexing agent before mixing the waste with cement. (Nogami, K.)

  19. Low-level activity of the trunk extensor muscles causes electromyographic manifestations of fatigue in absence of decreased oxygenation

    NARCIS (Netherlands)

    Dieën, J.H. van; Westebring van der; Putten, E.P.; Kingma, I.; Looze, M.P. de

    2009-01-01

    This study was designed to determine whether trunk extensor fatigue occurs during low-level activity and whether this is associated with a drop in muscle tissue oxygenation. Electromyography (EMG) feedback was used to impose constant activity in a part of the trunk extensor muscles. We hypothesized

  20. Enhanced catalytic hydrogenation activity of Ni/reduced graphene oxide nanocomposite prepared by a solid-state method

    Science.gov (United States)

    Li, Yizhao; Cao, Yali; Jia, Dianzeng

    2018-01-01

    A simple solid-state method has been applied to synthesize Ni/reduced graphene oxide (Ni/rGO) nanocomposite under ambient condition. Ni nanoparticles with size of 10-30 nm supported on reduced graphene oxide (rGO) nanosheets are obtained through one-pot solid-state co-reduction among nickel chloride, graphene oxide, and sodium borohydride. The Ni/rGO nanohybrid shows enhanced catalytic activity toward the reduction of p-nitrophenol (PNP) into p-aminophenol compared with Ni nanoparticles. The results of kinetic research display that the pseudo-first-order rate constant for hydrogenation reaction of PNP with Ni/rGO nanocomposite is 7.66 × 10-3 s-1, which is higher than that of Ni nanoparticles (4.48 × 10-3 s-1). It also presents superior turnover frequency (TOF, 5.36 h-1) and lower activation energy ( E a, 29.65 kJ mol-1) in the hydrogenation of PNP with Ni/rGO nanocomposite. Furthermore, composite catalyst can be magnetically separated and reused for five cycles. The large surface area and high electron transfer property of rGO support are beneficial for good catalytic performance of Ni/rGO nanocomposite. Our study demonstrates a simple approach to fabricate metal-rGO heterogeneous nanostructures with advanced functions.

  1. Level structure of 60Ni from the 58Ni(α,2p#betta#) reaction

    International Nuclear Information System (INIS)

    Chan, T.U.; Morand, C.; Azgui, F.

    1982-03-01

    The 60 Ni nucleus has been studied via the 58 Ni (α, 2p#betta#) reaction at Esub(α)=32 MeV using in-beam #betta# spectroscopy techniques. High-spin states up to 10 MeV excitation have been established. Among the 5 branches depopulating the Yrast Jsup(π)=7 - state, has been found an E3 transition down to the 4 + state. Comparison with direct reaction results leads to assign very probably the [#betta#fsub(5/2),#betta#gsub(9/2)] 7 - configuration to the Jsup(π)=7 - Yrast state at 5349 keV. Other high-spin states might be accounted for by the breaking of the 56 Ni core

  2. 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.

  3. Synthesis, Characterization, and NIR Reflectance of Highly Dispersed NiTiO3 and NiTiO3/TiO2 Composite Pigments

    Directory of Open Access Journals (Sweden)

    Yuping Tong

    2016-01-01

    Full Text Available The highly dispersed nanostructured NiTiO3 pigments and NiTiO3/TiO2 composite pigments can be synthesized at relative low temperature. The activation energy of crystal growth of NiTiO3 during calcinations via salt-assistant combustion method is 9.35 kJ/mol. The UV-vis spectra results revealed that the absorbance decreased with the increasing of calcinations temperature due to small size effect of nanometer particles. The optical data of NiTiO3 nanocrystals were analyzed at the near-absorption edge. SEM showed that the obtained NiTiO3 nanocrystals and NiTiO3/TiO2 nanocomposite were composed of highly dispersed spherical-like and spherical particles with uniform size distribution, respectively. The chromatic properties and diffuse reflectance of samples were investigated. The obtained NiTiO3/TiO2 composite samples have higher NIR reflectance than NiTiO3 pigments.

  4. Plasma-Assisted Synthesis of NiCoP for Efficient Overall Water Splitting

    KAUST Repository

    Liang, Hanfeng

    2016-11-09

    Efficient water splitting requires highly active, earth-abundant, and robust catalysts. Monometallic phosphides such as NiP have been shown to be active toward water splitting. Our theoretical analysis has suggested that their performance can be further enhanced by substitution with extrinsic metals, though very little work has been conducted in this area. Here we present for the first time a novel PH plasma-assisted approach to convert NiCo hydroxides into ternary NiCoP. The obtained NiCoP nanostructure supported on Ni foam shows superior catalytic activity toward the hydrogen evolution reaction (HER) with a low overpotential of 32 mV at 10 mA cm in alkaline media. Moreover, it is also capable of catalyzing the oxygen evolution reaction (OER) with high efficiency though the real active sites are surface oxides in situ formed during the catalysis. Specifically, a current density of 10 mA cm is achieved at overpotential of 280 mV. These overpotentials are among the best reported values for non-noble metal catalysts. Most importantly, when used as both the cathode and anode for overall water splitting, a current density of 10 mA cm is achieved at a cell voltage as low as 1.58 V, making NiCoP among the most efficient earth-abundant catalysts for water splitting. Moreover, our new synthetic approach can serve as a versatile route to synthesize various bimetallic or even more complex phosphides for various applications.

  5. Test of level density models from reactions of Li6 on Fe58 and Li7 on Fe57

    Science.gov (United States)

    Oginni, B. M.; Grimes, S. M.; Voinov, A. V.; Adekola, A. S.; Brune, C. R.; Carter, D. E.; Heinen, Z.; Jacobs, D.; Massey, T. N.; O'Donnell, J. E.; Schiller, A.

    2009-09-01

    The reactions of Li6 on Fe58 and Li7 on Fe57 have been studied at 15 MeV beam energy. These two reactions produce the same compound nucleus, Cu64. The charged particle spectra were measured at backward angles. The data obtained have been compared with Hauser-Feshbach model calculations. The level density parameters of Ni63 and Co60 have been obtained from the particle evaporation spectra. We also find contributions from the break up of the lithium projectiles to the low energy region of the α spectra.

  6. Catalytic reforming of glycerol in supercritical water over bimetallic Pt-Ni catalyst

    NARCIS (Netherlands)

    Chakinala, A.G.; van Swaaij, Willibrordus Petrus Maria; Kersten, Sascha R.A.; de Vlieger, Dennis; Seshan, Kulathuiyer; Brilman, Derk Willem Frederik

    2013-01-01

    Catalytic reforming of pure glycerol for the production of hydrogen at low temperature and short residence times in supercritical water was investigated using a bimetallic Pt–Ni catalyst supported on alumina. Initial tests were carried out to study the reforming activity of bimetallic Pt–Ni

  7. Experimental observations on uniaxial whole-life transformation ratchetting and low-cycle stress fatigue of super-elastic NiTi shape memory alloy micro-tubes

    Science.gov (United States)

    Song, Di; Kang, Guozheng; Kan, Qianhua; Yu, Chao; Zhang, Chuanzeng

    2015-07-01

    In this work, the low-cycle fatigue failure of super-elastic NiTi shape memory alloy micro-tubes with a wall thickness of 150 μm is investigated by uniaxial stress-controlled cyclic tests at human body temperature 310 K. The effects of mean stress, peak stress, and stress amplitude on the uniaxial whole-life transformation ratchetting and fatigue failure of the NiTi alloy are observed. It is concluded that the fatigue life depends significantly on the stress levels, and the extent of martensite transformation and its reverse play an important role in determining the fatigue life. High peak stress or complete martensite transformation shortens the fatigue life.

  8. Experimental observations on uniaxial whole-life transformation ratchetting and low-cycle stress fatigue of super-elastic NiTi shape memory alloy micro-tubes

    International Nuclear Information System (INIS)

    Song, Di; Kang, Guozheng; Kan, Qianhua; Yu, Chao; Zhang, Chuanzeng

    2015-01-01

    In this work, the low-cycle fatigue failure of super-elastic NiTi shape memory alloy micro-tubes with a wall thickness of 150 μm is investigated by uniaxial stress-controlled cyclic tests at human body temperature 310 K. The effects of mean stress, peak stress, and stress amplitude on the uniaxial whole-life transformation ratchetting and fatigue failure of the NiTi alloy are observed. It is concluded that the fatigue life depends significantly on the stress levels, and the extent of martensite transformation and its reverse play an important role in determining the fatigue life. High peak stress or complete martensite transformation shortens the fatigue life. (paper)

  9. Low-activation Mn-Cr austenitic stainless steel with further reduced content of long-lived radioactive elements

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, M.; Saida, T.; Hirai, S. [Mitsubishi Heavy Ind. Ltd., Yokohama (Japan); Kusuhashi, M.; Sato, I.; Hatakeyama, T. [The Japan Steel Works Ltd., Chatsu-machi 4, Muroran 051-8505 (Japan)

    1998-06-01

    Low-activation austenitic stainless steel based on Mn-Cr non-magnetic steels has been developed. The alloying elements of long-life activation, such as Ni, Mo and Co, were eliminated and substituted with Mn along with an addition of N. A Mn-Cr austenitic stainless steel, 24.5Mn-13.5Cr-0.02C-0.2N, has been developed successfully. Examined material properties, including mechanical, thermal and magnetic properties, as well as weldability and characteristics of corrosion resistance, are presented. It was found that the alloy has excellent material properties virtually equivalent to those of 316SS. In this study, the applicability of the Schaeffler, DeLong and Hull constitution diagrams for the stainless steels with low Ni and high Mn contents was also examined. The boundary conditions distinguishing the single austenite phase from the others have been identified for the Mn-Cr steels. (orig.) 22 refs.

  10. Low-activation Mn Cr austenitic stainless steel with further reduced content of long-lived radioactive elements

    Science.gov (United States)

    Onozuka, Masanori; Saida, Tomikane; Hirai, Shouzou; Kusuhashi, Mikio; Sato, Ikuo; Hatakeyama, Tsuyoshi

    1998-06-01

    Low-activation austenitic stainless steel based on Mn-Cr non-magnetic steels has been developed. The alloying elements of long-life activation, such as Ni, Mo and Co, were eliminated and substituted with Mn along with an addition of N. A Mn-Cr austenitic stainless steel, 24.5Mn-13.5Cr-0.02C-0.2N, has been developed successfully. Examined material properties, including mechanical, thermal and magnetic properties, as well as weldability and characteristics of corrosion resistance, are presented. It was found that the alloy has excellent material properties virtually equivalent to those of 316SS. In this study, the applicability of the Schaeffler, DeLong and Hull constitution diagrams for the stainless steels with low Ni and high Mn contents was also examined. The boundary conditions distinguishing the single austenite phase from the others have been identified for the Mn-Cr steels.

  11. Association of physical activity level with depression, anxiety, and quality of life in children with type 1 diabetes mellitus.

    Science.gov (United States)

    Mutlu, Ebru Kaya; Mutlu, Caner; Taskiran, Hanifegul; Ozgen, Ilker Tolga

    2015-11-01

    Children with type 1 diabetes mellitus (T1DM) have low physical activity levels and are at high risk for psychosocial morbidities, including depression, heightened anxiety and low health-related quality of life (HRQoL). The aim of this study was to assess the associations of physical activity level with depression, anxiety, and HRQoL in children with T1DM. A cross-sectional study design, including children with T1DM aged between 8 and 12 years and healthy controls, was used. Physical activity (PA) level was assessed with the Physical Activity Questionnaire for Older Children (PAQ-C). Anxiety was screened by The Screen for Anxiety Related Emotional Disorders (SCARED) questionnaire. Depressive symptoms were evaluated using the Children's Depression Inventory (CDI). Quality of life was assessed with the The Pediatric Quality of Life Inventory 4.0 (PedsQL 4.0). Forty-seven T1DM and 55 healthy children were included with mean ages of 9.87±1.63 and 9.56±1.60 years, respectively. The T1DM group had significantly higher depression and anxiety score (pchildren with T1DM. The result of our study suggested that only HRQoL was related to physical activity, anxiety and HbA1c in children with T1DM.

  12. A population-based randomized controlled trial of the effect of combining a pedometer with an intervention toolkit on physical activity among individuals with low levels of physical activity or fitness

    DEFF Research Database (Denmark)

    Petersen, Christina Bjørk; Severin, Maria; Hansen, Andreas Wolff

    2012-01-01

    To examine if receiving a pedometer along with an intervention toolkit is associated with increased physical activity, aerobic fitness and better self-rated health among individuals with low levels of physical activity or fitness.......To examine if receiving a pedometer along with an intervention toolkit is associated with increased physical activity, aerobic fitness and better self-rated health among individuals with low levels of physical activity or fitness....

  13. The molecular basis of low activity levels of coagulation factor VII: a Brazilian cohort.

    Science.gov (United States)

    Rabelo, F Y; Jardim, L L; Landau, M B; Gadelha, T; Corrêa, M F B; Pereira, I F M; Rezende, S M

    2015-09-01

    Inherited factor VII (FVII) deficiency is the most common among the rare bleeding disorders. It is transmitted as an autosomal recessive inheritance, due to mutations in the FVII gene (F7). Molecular studies of FVII deficiency are rare in non-Caucasian populations. The aim of the study was to evaluate the molecular basis behind low levels of FVII activity (FVII:C) levels in a cohort of Brazilian patients. A total of 34 patients with low FVII levels were clinically evaluated and submitted to laboratory tests, among these, prothrombin time and FVII:C, with different thromboplastins. All exons and intron/exon boundaries of F7 were amplified and sequenced. A total of 14 genetic alterations were identified, of which six were described previously, c.1091G>A, c.1151C>T, c.-323_-313insCCTATATCCT, c.285G>A, c.525C>T, c.1238G>A and eight (54.0%) and eight were new, c.128G>A, c.252C>T, c.348G>A, c.417G>A, c.426G>A, c.745_747delGTG, c.843G>A and c.805+52C>T. In addition to the mutation c.1091G>A, known as FVII Padua, the mutation c.1151C>T also presented discrepant FVII:C levels when tested with human and rabbit brain thromboplastin. There was no association between phenotype and genotype. Most of the identified genetic alterations found were polymorphisms. Low levels of FVII:C in this population were mostly related to polymorphisms in F7 and associated with a mild clinical phenotype. Mutation c.1151C>T was associated with discrepant levels of FVII:C using different thromboplastins, such as reported with FVII Padua. © 2015 John Wiley & Sons Ltd.

  14. The atomistic origin of the extraordinary oxygen reduction activity of Pt3Ni7 fuel cell catalysts.

    Science.gov (United States)

    Fortunelli, Alessandro; Goddard Iii, William A; Sementa, Luca; Barcaro, Giovanni; Negreiros, Fabio R; Jaramillo-Botero, Andrés

    2015-07-01

    Recently Debe et al. reported that Pt 3 Ni 7 leads to extraordinary Oxygen Reduction Reaction (ORR) activity. However, several reports show that hardly any Ni remains in the layers of the catalysts close to the surface ("Pt-skin effect"). This paradox that Ni is essential to the high catalytic activity with the peak ORR activity at Pt 3 Ni 7 while little or no Ni remains close to the surface is explained here using large-scale first-principles-based simulations. We make the radical assumption that processing Pt-Ni catalysts under ORR conditions would leach out all Ni accessible to the solvent. To simulate this process we use the ReaxFF reactive force field, starting with random alloy particles ranging from 50% Ni to 90% Ni and containing up to ∼300 000 atoms, deleting the Ni atoms, and equilibrating the resulting structures. We find that the Pt 3 Ni 7 case and a final particle radius around 7.5 nm lead to internal voids in communication with the exterior, doubling the external surface footprint, in fair agreement with experiment. Then we examine the surface character of these nanoporous systems and find that a prominent feature in the surface of the de-alloyed particles is a rhombic structure involving 4 surface atoms which is crystalline-like but under-coordinated. Using density-functional theory, we calculate the energy barriers of ORR steps on Pt nanoporous catalysts, focusing on the O ad -hydration reaction (O ad + H 2 O ad → OH ad + OH ad ) but including the barriers of O 2 dissociation (O 2ad → O ad + O ad ) and water formation (OH ad + H ad → H 2 O ad ). We find that the reaction barrier for the O ad -hydration rate-determining-step is reduced significantly on the de-alloyed surface sites compared to Pt(111). Moreover we find that these active sites are prevalent on the surface of particles de-alloyed from a Pt-Ni 30 : 70 initial composition. These simulations explain the peak in surface reactivity at Pt 3 Ni 7 , and provide a rational guide to

  15. Commercial low-level radioactive waste management

    International Nuclear Information System (INIS)

    Coleman, J.A.

    1982-01-01

    The goals, objectives and activities of the Department of Energy's Low-Level Radioactive Waste Management program are reviewed. The goal of the overall Program is to support development of an acceptable, nationwide, near surface waste disposal system by 1986. The commercial LLW program has two major functions: (1) application of the technology improvements for waste handling, treatment and disposal, and (2) assistance to states as they carry out their responsibilities under the Low-Level Radioactive Waste Policy Act of 1980. The priorities for the commercial side of the Low-Level Waste Management Program have been established to meet one goal: to support development of an effective commercial management system by 1986. The first priority is being given to supporting state efforts in forming the institutional structures needed to manage the system. The second priority is the state and industry role in transferring and demonstrating treatment and disposal technologies

  16. Health effects of low-level ionizing radiation

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1979-04-01

    It is now assumed that any exposure to radiaton at low levels of dose carries some risk of deleterious effects. How low this level may be, or the probability or magnitude of the risk, still are not known. Our best scientific knowledge and advice are essential for the protection of the public health, for the effective application of new technologies in medicine and industry and for guidance in the production of nuclear energy. Unless man wishes to dispense with those activities which inevitably involve exposure to low levels of ionizing radiations, he must recognize that some degree of risk to health, however small, exists. A pragmatic appraisal of how man wishes to continue to derive the benefits of health and happiness from such activities involving ionizing radiaton in times of everchanging conditions and public attitudes in our resource-limited society is the task which lies before all of us - all men and women of our society, of science and of medicine, and of law and government - now and in the future

  17. Pt Single Atoms Embedded in the Surface of Ni Nanocrystals as Highly Active Catalysts for Selective Hydrogenation of Nitro Compounds.

    Science.gov (United States)

    Peng, Yuhan; Geng, Zhigang; Zhao, Songtao; Wang, Liangbing; Li, Hongliang; Wang, Xu; Zheng, Xusheng; Zhu, Junfa; Li, Zhenyu; Si, Rui; Zeng, Jie

    2018-06-13

    Single-atom catalysts exhibit high selectivity in hydrogenation due to their isolated active sites, which ensure uniform adsorption configurations of substrate molecules. Compared with the achievement in catalytic selectivity, there is still a long way to go in exploiting the catalytic activity of single-atom catalysts. Herein, we developed highly active and selective catalysts in selective hydrogenation by embedding Pt single atoms in the surface of Ni nanocrystals (denoted as Pt 1 /Ni nanocrystals). During the hydrogenation of 3-nitrostyrene, the TOF numbers based on surface Pt atoms of Pt 1 /Ni nanocrystals reached ∼1800 h -1 under 3 atm of H 2 at 40 °C, much higher than that of Pt single atoms supported on active carbon, TiO 2 , SiO 2 , and ZSM-5. Mechanistic studies reveal that the remarkable activity of Pt 1 /Ni nanocrystals derived from sufficient hydrogen supply because of spontaneous dissociation of H 2 on both Pt and Ni atoms as well as facile diffusion of H atoms on Pt 1 /Ni nanocrystals. Moreover, the ensemble composed of the Pt single atom and nearby Ni atoms in Pt 1 /Ni nanocrystals leads to the adsorption configuration of 3-nitrostyrene favorable for the activation of nitro groups, accounting for the high selectivity for 3-vinylaniline.

  18. Fear of Movement and Low Self-Efficacy Are Important Barriers in Physical Activity after Renal Transplantation.

    Directory of Open Access Journals (Sweden)

    Dorien M Zelle

    Full Text Available Physical activity (PA and exercise are commonly used as preventive measures for cardiovascular disease in the general population, and could be effective in the management of post-transplantation cardiovascular risk. PA levels are low after renal transplantation and very few renal transplant recipients (RTR meet the PA guidelines. Identification of barriers to regular PA is important to identify targets for intervention to improve PA levels after renal transplantation. We investigated fear of movement and physical self-efficacy as barriers to PA in RTR.RTR were investigated between 2001-2003. The Tampa Score of Kinesiophobia-Dutch Version (TSK-11 was used to assess fear of movement. Physical self-efficacy was measured with the LIVAS-scale. PA was assessed using validated questionnaires (Tecumseh Occupational Activity Questionnaire and the Minnesota Leisure Time Physical Activity Questionnaire.A total of 487 RTR (age 51±12 years, 55% men were studied. Median score [interquartile range] on TSK-11 was 22 [17-26]. Low physical self-efficacy (Exp B:0.41[0.31-0.54], p<0.001 and history of myocardial infarction, transient ischemic attack and cerebrovascular accident (Exp B:1.30[1.03-1.63],p = 0.03 were independent determinants for fear of movement. Fear of movement was associated with lower daily PA, occupational, sports and leisure time PA. Mediation-analysis showed that a large part (73% of the effect of fear of movement on PA was explained by low physical self-efficacy.This study was the first to examine fear of movement and self-efficacy in relation to PA in RTR. Fear of movement was associated with a low PA level, and the larger part of this relation was mediated by low physical self-efficacy. Both fear of movement and physical self-efficacy level are important targets for intervention during rehabilitation after renal transplantation.

  19. Greater-than-Class C low-level radioactive waste characterization. Appendix A-3: Basis for greater-than-Class C low-level radioactive waste light water reactor projections

    International Nuclear Information System (INIS)

    Mancini, A.; Tuite, P.; Tuite, K.; Woodberry, S.

    1994-09-01

    This study characterizes low-level radioactive waste types that may exceed Class C limits at light water reactors, estimates the amounts of waste generated, and estimates radionuclide content and distribution within the waste. Waste types that may exceed Class C limits include metal components that become activated during operations, process wastes such as cartridge filters and decontamination resins, and activated metals from decommissioning activities. Operating parameters and current management practices at operating plants are reviewed and used to estimate the amounts of low-level waste exceeding Class C limits that is generated per fuel cycle, including amounts of routinely generated activated metal components and process waste. Radionuclide content is calculated for specific activated metals components. Empirical data from actual low-level radioactive waste are used to estimate radionuclide content for process wastes. Volumes and activities are also estimated for decommissioning activated metals that exceed Class C limits. To estimate activation levels of decommissioning waste, six typical light water reactors are modeled and analyzed. This study does not consider concentration averaging

  20. Low levels of physical activity in patients with severe mental illness

    DEFF Research Database (Denmark)

    Nyboe, Lene; Lund, H

    2013-01-01

    Background: Physical inactivity is an independent risk factor for cardiovascular diseases and Type 2 diabetes, both being highly prevalent in patients with severe mental illness. Though physical activity has become an important issue in psychiatric treatment and rehabilitation in the past decade......, systematic evaluations of physical activity level in psychiatric populations could be more disseminated. Aim: The primary aim of the study was to investigate the physical activity level of psychiatric patients in comparison with healthy controls. Methods: Patients with severe mental illness (n =47......) and a group of healthy controls (n =28) matched on sex and age reported their physical activity level using the Physical Activity Scale (PAS). PAS was administered as an interview in relation to patients and as a questionnaire in relation to healthy controls. Results: Patients had statistically significant...

  1. Low-level waste management

    International Nuclear Information System (INIS)

    Levin, G.B.

    1980-01-01

    An overview of the current situation in the United States and a look to the future of low-level waste management are presented. Current problems and challenges are discussed, such as: the need of additional disposal sites in the future; risks and costs involved in transport of low-level wastes; reduction of low-level waste volume through smelting, incineration, and storage for wastes containing nuclides with short half lives; development of a national policy for the management of low-level waste, and its implementation through a sensible system of regulations. Establishing a success with low-level waste management should provide the momentum and public confidence needed to continue on and to resolve the technical and politically more difficult low-level waste problems

  2. Exchange bias in sputtered FeNi/FeMn systems: Effect of short low-temperature heat treatments

    Energy Technology Data Exchange (ETDEWEB)

    Savin, Peter, E-mail: peter.savin@urfu.ru [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Guzmán, Jorge [Instituto de Ciencia de Materiales de Madrid-CSIC, 28049 Madrid (Spain); Lepalovskij, Vladimir [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Svalov, Andrey; Kurlyandskaya, Galina [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Departamento de Electricidad y Electrónica, Universidad del País Vasco (UPV/EHU), 48940 Leioa, Vizcaya (Spain); Asenjo, Agustina [Instituto de Ciencia de Materiales de Madrid-CSIC, 28049 Madrid (Spain); Vas’kovskiy, Vladimir [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Vazquez, Manuel [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Instituto de Ciencia de Materiales de Madrid-CSIC, 28049 Madrid (Spain)

    2016-03-15

    Short (5 min) post-deposition thermal treatments under magnetic field at low temperature (up to 200 °C) performed in exchange-coupled FeNi(40 nm)/FeMn(20 nm) bilayer thin films prepared by magnetron sputtering are shown to be effective to significantly modify their exchange field (from around 40 Oe down to 27 Oe) between FeNi and FeMn layers. A similar exchange field decrease was observed for the first deposited FeNi layer of the FeNi(40 nm)/FeMn(20 nm)/FeNi(40 nm) trilayer films after the same thermal treatments. The exchange field value for the second FeNi layer was not substantially changed. The X-ray diffraction patterns indicates that such a heat treatment has no effect on the grain size and crystalline texture of the films, while atomic force microscope studies reveal an increase of the surface roughness after the treatment which is more noticeable in the case of the trilayer film. Analysis of the experimental results leads us to conclude that the variations of the exchange field after heat treatment are likely caused by a modification of interfacial roughness and/or interfacial magnetic structure, but unlikely by the changes in the microstructure and/or changes of composition of the antiferromagnetic FeMn layer. - Highlights: • FeNi/FeMn bilayers and FeNi/FeMn/FeNi trilayers were prepared by magnetron sputtering. • Post-deposition heat treatments at the temperatures below 200 °C during 5 min were made. • Annealing reduces the exchange field for the first FeNi layer in trilayers. • The exchange field value for the second FeNi layer was not substantially changed. • Exchange field changes are most likely caused by a modification of interface roughness.

  3. Improved gamma spectrometry of very low level radioactive samples

    International Nuclear Information System (INIS)

    Pineira, T.H.

    1989-01-01

    Today, many laboratories face the need to perform measurements of very low level activities using gamma spectroscopy. The techniques in use are identical to those applicable for higher levels of activities, but there is a need to use better adapted materials and modify the measurement conditions to minimize the background noise around the area. This paper presents the design of a very low level activity laboratory which has addressed the laboratory itself, the measuring chamber and the detector. The lab is constructed underground using specially selected materials of construction. The lab atmosphere is filtered and recycled with frequent changeovers. The rate of make-up fresh air is reduced and is sampled high above ground and filtered

  4. Towards Smart Homes Using Low Level Sensory Data

    Directory of Open Access Journals (Sweden)

    Young-Koo Lee

    2011-12-01

    Full Text Available Ubiquitous Life Care (u-Life care is receiving attention because it provides high quality and low cost care services. To provide spontaneous and robust healthcare services, knowledge of a patient’s real-time daily life activities is required. Context information with real-time daily life activities can help to provide better services and to improve healthcare delivery. The performance and accuracy of existing life care systems is not reliable, even with a limited number of services. This paper presents a Human Activity Recognition Engine (HARE that monitors human health as well as activities using heterogeneous sensor technology and processes these activities intelligently on a Cloud platform for providing improved care at low cost. We focus on activity recognition using video-based, wearable sensor-based, and location-based activity recognition engines and then use intelligent processing to analyze the context of the activities performed. The experimental results of all the components showed good accuracy against existing techniques. The system is deployed on Cloud for Alzheimer’s disease patients (as a case study with four activity recognition engines to identify low level activity from the raw data captured by sensors. These are then manipulated using ontology to infer higher level activities and make decisions about a patient’s activity using patient profile information and customized rules.

  5. PT AND PT/NI "NEEDLE" ELETROCATALYSTS ON CARBON NANOTUBES WITH HIGH ACTIVITY FOR THE ORR

    Energy Technology Data Exchange (ETDEWEB)

    Colon-Mercado, H.

    2011-11-10

    Platinum and platinum/nickel alloy electrocatalysts supported on graphitized (gCNT) or nitrogen doped carbon nanotubes (nCNT) are prepared and characterized. Pt deposition onto carbon nanotubes results in Pt 'needle' formations that are 3.5 nm in diameter and {approx}100 nm in length. Subsequent Ni deposition and heat treatment results in PtNi 'needles' with an increased diameter. All Pt and Pt/Ni materials were tested as electrocatalysts for the oxygen reduction reaction (ORR). The Pt and Pt/Ni catalysts showed excellent performance for the ORR, with the heat treated PtNi/gCNT (1.06 mA/cm{sup 2}) and PtNi/nCNT (0.664 mA/cm{sup 2}) showing the highest activity.

  6. Radioactivity evaluation method for pre-packed concrete packages of low-level dry active wastes

    International Nuclear Information System (INIS)

    Sakai, Toshiaki; Funahashi, Tetsuo; Watabe, Kiyomi; Ozawa, Yukitoshi; Kashiwagi, Makoto

    1998-01-01

    Low-level dry active wastes of nuclear power plants are grouted with cement mortal in a container and planned to disposed into the shallow land disposal site. The characteristics of radionuclides contained in dry active wastes are same as homogeneous solidified wastes. In the previous report, we reported the applicability of the radioactivity evaluation methods established for homogeneous solidified wastes to pre-packed concrete packages. This report outlines the developed radioactivity evaluation methods for pre-packed concrete packages based upon recent data. Since the characteristics of dry active wastes depend upon the plant system in which dry active wastes originate and the types of contamination, sampling of wastes and activity measurement were executed to derive scaling factors. The radioactivity measurement methods were also verified. The applicability of non-destructive methods to measure radioactivity concentration of pre-packed concrete packages was examined by computer simulation. It is concluded that those methods are accurate enough to measure actual waste packages. (author)

  7. Green synthesis of Ni-Nb oxide catalysts for low-temperature oxidative dehydrogenation of ethane.

    Science.gov (United States)

    Zhu, Haibo; Rosenfeld, Devon C; Anjum, Dalaver H; Caps, Valérie; Basset, Jean-Marie

    2015-04-13

    The straightforward solid-state grinding of a mixture of Ni nitrate and Nb oxalate crystals led to, after mild calcination (Tethane to ethylene at a relatively low temperature (Tethane. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Redox poly[Ni(saldMp)] modified activated carbon electrode in electrochemical supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Gao Fei [Department of Physical Chemistry, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083 (China); Li Jianling, E-mail: lijianling@ustb.edu.c [Department of Physical Chemistry, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083 (China); Zhang Yakun; Wang Xindong [Department of Physical Chemistry, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083 (China); Kang Feiyu [Department of Material Science and Engineering, Tsinghua University, Beijing 100083 (China)

    2010-08-01

    The complex (2,2-dimethyl-1,3-propanediaminebis(salicylideneaminato))-nickel(II), [Ni(saldMp)], was oxidatively electropolymerized on activated carbon (AC) electrode in acetonitrile solution. The poly[Ni(saldMp)] presented an incomplete coated film on the surface of carbon particles of AC electrode by field emission scanning electron microscopy. The electrochemical behaviors of poly[Ni(saldMp)] modified activated carbon (PAC) electrode were evaluated in different potential ranges by cyclic voltammetry. Counterions and solvent swelling mainly occurred up to 0.6 V for PAC electrode by the comparison of D{sup 1/2}C values calculated from chronoamperometry experiments. Both the Ohmic resistance and Faraday resistance of PAC electrode gradually approached to those of AC electrode when its potential was ranging from 1.2 V to 0.0 V. Galvanostatic charge/discharge experiments indicated that both the specific capacitance and energy density were effectively improved by the reversible redox reaction of poly[Ni(saldMp)] film under the high current density up to 10 mA cm{sup -2} for AC electrode. The specific capacitance of PAC electrode decreased during the first 50 cycles but thereafter it remained constant for the next 200 cycles. This study showed the redox polymer may be an attractive material in supercapacitors.

  9. METHANE DRY REFORMING OVER Ni SUPPORTED ON PINE SAWDUST ACTIVATED CARBON: EFFECTS OF SUPPORT SURFACE PROPERTIES AND METAL LOADING

    Directory of Open Access Journals (Sweden)

    Rafael García

    2015-05-01

    Full Text Available The influence of metal loading and support surface functional groups (SFG on methane dry reforming (MDR over Ni catalysts supported on pine-sawdust derived activated carbon were studied. Using pine sawdust as the catalyst support precursor, the smallest variety and lowest concentration of SFG led to best Ni dispersion and highest catalytic activity, which increased with Ni loading up to 3 Ni atoms nm-2. At higher Ni loading, the formation of large metal aggregates was observed, consistent with a lower "apparen" surface area and a decrease in catalytic activity. The H2/CO ratio rose with increasing reaction temperature, indicating that increasingly important side reactions were taking place in addition to MDR.

  10. Physical activity level at work and risk of chronic low back pain: A follow-up in the Nord-Trøndelag Health Study.

    Science.gov (United States)

    Heuch, Ingrid; Heuch, Ivar; Hagen, Knut; Zwart, John-Anker

    2017-01-01

    Physical activity in leisure time seems to reduce the risk of low back pain, but it is not known whether occupational activity, as recorded in a representative working population, produces a higher or lower risk. To study associations between physical activity level at work and risk of chronic low back pain. Associations were examined in a Norwegian prospective study using data from the HUNT2 and HUNT3 surveys carried out in the whole county of Nord-Trøndelag. Participants were 7580 women and 7335 men who supplied information about physical activity level at work. Levels considered were sedentary work, work involving walking but no heavy lifting, work involving walking and heavy lifting, and particularly strenuous physical work. Nobody in the cohort was affected by chronic low back pain at baseline. After 11 years, participants reported whether they suffered from chronic low back pain. Generalized linear modelling with adjustment for potential confounders was applied to assess associations with risk factors. In age-adjusted analyses both women and men showed statistically significant associations between physical activity at work and risk of chronic low back pain, suggesting positive relationships. For particularly strenuous physical work the relative risk of chronic low back pain was 1.30 (95% CI: 1.00-1.71) in women and 1.36 (95% CI 1.17-1.59) in men, compared to sedentary work. Women still showed a general association with activity level after adjustment for education, leisure time physical activity, BMI, smoking and occupational category. In men, the higher risk was only maintained for particularly strenuous work. In this cohort, women had a higher risk of chronic low back pain with work involving walking and heavy lifting or particularly strenuous work, compared to sedentary work. Men participating in particularly strenuous work also experienced a higher risk of chronic low back pain.

  11. Physical activity level at work and risk of chronic low back pain: A follow-up in the Nord-Trøndelag Health Study.

    Directory of Open Access Journals (Sweden)

    Ingrid Heuch

    Full Text Available Physical activity in leisure time seems to reduce the risk of low back pain, but it is not known whether occupational activity, as recorded in a representative working population, produces a higher or lower risk.To study associations between physical activity level at work and risk of chronic low back pain.Associations were examined in a Norwegian prospective study using data from the HUNT2 and HUNT3 surveys carried out in the whole county of Nord-Trøndelag. Participants were 7580 women and 7335 men who supplied information about physical activity level at work. Levels considered were sedentary work, work involving walking but no heavy lifting, work involving walking and heavy lifting, and particularly strenuous physical work. Nobody in the cohort was affected by chronic low back pain at baseline. After 11 years, participants reported whether they suffered from chronic low back pain. Generalized linear modelling with adjustment for potential confounders was applied to assess associations with risk factors.In age-adjusted analyses both women and men showed statistically significant associations between physical activity at work and risk of chronic low back pain, suggesting positive relationships. For particularly strenuous physical work the relative risk of chronic low back pain was 1.30 (95% CI: 1.00-1.71 in women and 1.36 (95% CI 1.17-1.59 in men, compared to sedentary work. Women still showed a general association with activity level after adjustment for education, leisure time physical activity, BMI, smoking and occupational category. In men, the higher risk was only maintained for particularly strenuous work.In this cohort, women had a higher risk of chronic low back pain with work involving walking and heavy lifting or particularly strenuous work, compared to sedentary work. Men participating in particularly strenuous work also experienced a higher risk of chronic low back pain.

  12. Low-level Radioactive waste Management

    International Nuclear Information System (INIS)

    1991-01-01

    This meeting describes low-level radioactive waste management problems and contains 8 papers: 1 Low-level radioactive waste management: exemption concept and criteria used by international organizations. 2 Low-level radioactive waste management: french and foreign regulations 3 Low-level radioactive waste management in EDF nuclear power plants (FRANCE) 4 Low-level radioactive waste management in COGEMA (FRANCE) 5 Importance of low-level radioactive wastes in dismantling strategy in CEA (FRANCE) 6 Low-level radioactive waste management in hospitals 7 Low-level radioactive waste disposal: radiation protection laws 8 Methods of low-level radioactive materials measurements during reactor dismantling or nuclear facilities demolition (FRANCE)

  13. IRMM low level underground laboratory in HADES

    Energy Technology Data Exchange (ETDEWEB)

    Mouchel, D [CEC-JRC, Inst. for Reference Materials and Measurements (IRMM), Geel (Belgium); Wordel, R [CEC-JRC, Inst. for Reference Materials and Measurements (IRMM), Geel (Belgium)

    1997-03-01

    The operation of low background HPGe detectors at a depth of 225 m, reduced the background by two orders of magnitude; a large amount of the remaining background is still attributable to the cosmic rays. The selection of radiopure materials, the characterization of reference matrices and the measurements of low radioactivities in environmental samples are performed. Coupling the low level spectrometry with additional techniques, e.g. neutron activation, will allow to measure extremely low radioactivities. (orig.)

  14. Effect of phosphorus addition on the hydrotreating activity of NiMo/Al{sub 2}O{sub 3} carbide catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Sundaramurthy, V.; Dalai, A.K. [Catalysis and Chemical Reaction Engineering Laboratories, Department of Chemical Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9 (Canada); Adjaye, J. [Syncrude Edmonton Research Centre, Edmonton, AB T6N 1H4 (Canada)

    2007-07-30

    A series of phosphorus promoted {gamma}-Al{sub 2}O{sub 3} supported NiMo carbide catalysts with 0-4.5 wt.% P, 13 wt.% Mo and 2.5 wt.% Ni were synthesized and characterized by elemental analysis, pulsed CO chemisorption, BET surface area measurement, X-ray diffraction, near-edge X-ray absorption fine structure, DRIFT spectroscopy of CO adsorption and H{sub 2} temperature programmed reduction. X-ray diffraction patterns and CO uptake showed the P addition to NiMo/{gamma}-Al{sub 2}O{sub 3} carbide, increased the dispersion of {beta}-Mo{sub 2}C particles. DRIFT spectra of adsorbed CO revealed that P addition to NiMo/{gamma}-Al{sub 2}O{sub 3} carbide catalyst not only increases the dispersion of Ni-Mo carbide phase, but also changes the nature of surface active sites. The hydrodenitrogenation (HDN) and hydrodesulfurization (HDS) activities of these P promoted NiMo/{gamma}-Al{sub 2}O{sub 3} carbide catalysts were performed in trickle bed reactor using light gas oil (LGO) derived from Athabasca bitumen and model feed containing quinoline and dibenzothiophene at industrial conditions. The P added NiMo/{gamma}-Al{sub 2}O{sub 3} carbide catalysts showed enhanced HDN activity compared to the NiMo/{gamma}-Al{sub 2}O{sub 3} catalysts with both the feed stocks. The P had almost no influence on the HDS activity of NiMo/{gamma}-Al{sub 2}O{sub 3} carbide with LGO and dibenzothiophene. P addition to NiMo/{gamma}-Al{sub 2}O{sub 3} carbide accelerated C-N bond breaking and thus increased the HDN activity. (author)

  15. Multiple functionalities of Ni nanoparticles embedded in carboxymethyl guar gum polymer: catalytic activity and superparamagnetism

    International Nuclear Information System (INIS)

    Sardar, Debasmita; Sengupta, Manideepa; Bordoloi, Ankur; Ahmed, Md. A.; Neogi, S.K.; Bandyopadhyay, Sudipta; Jain, Ruchi; Gopinath, Chinnakonda S.; Bala, Tanushree

    2017-01-01

    Highlights: • Ni nanoparticles were synthesized in polymer to form Ni-Polymer composite. • Ni nanoparticles retain their superparamagnetism in the composite. • Ni-Polymer composites showed catalytic activity. - Abstract: Composites comprising of metallic nanoparticles in polymer matrices have allured significant importance due to multifunctionalities. Here a simple protocol has been described to embed Ni nanoparticles in carboxymethyl guar gum (CMGG) polymer. The composite formation helps in the stabilization of Ni nanoparticles which are otherwise prone towards aerial oxidation. Further the nanoparticles retain their superparamagnetic nature and catalytic capacity. Ni-Polymer composite catalyses the reduction of 4-Nitrophenol to 4-Aminophenol very efficiently in presence of NaBH_4, attaining a complete conversion under some experimental conditions. Ni-Polymer composite is well characterized using UV–vis spectroscopy, FTIR, XPS, powder XRD, TGA, SEM and TEM. A detailed magnetic measurement using superconducting quantum interference device-vibrating sample magnetometer (SQUID-VSM) reveals superparamagnetic behaviour of the composite.

  16. Multiple functionalities of Ni nanoparticles embedded in carboxymethyl guar gum polymer: catalytic activity and superparamagnetism

    Energy Technology Data Exchange (ETDEWEB)

    Sardar, Debasmita [Department of Chemistry, University of Calcutta, 92 A.P.C. Road, Kolkata 700009 (India); Sengupta, Manideepa; Bordoloi, Ankur [Nano Catalysis, Catalytic Conversion and Process Division, CSIR—Indian Institute of Petroleum (IIP), Mohkampur, Dehradun 248005 (India); Ahmed, Md. A.; Neogi, S.K.; Bandyopadhyay, Sudipta [Department of Physics, University of Calcutta, 92 A.P.C. Road, Kolkata 700009 (India); Jain, Ruchi; Gopinath, Chinnakonda S. [Catalysis Division and Center of Excellence on Surface Science, CSIR—National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008 (India); Bala, Tanushree, E-mail: tanushreebala@gmail.com [Department of Chemistry, University of Calcutta, 92 A.P.C. Road, Kolkata 700009 (India)

    2017-05-31

    Highlights: • Ni nanoparticles were synthesized in polymer to form Ni-Polymer composite. • Ni nanoparticles retain their superparamagnetism in the composite. • Ni-Polymer composites showed catalytic activity. - Abstract: Composites comprising of metallic nanoparticles in polymer matrices have allured significant importance due to multifunctionalities. Here a simple protocol has been described to embed Ni nanoparticles in carboxymethyl guar gum (CMGG) polymer. The composite formation helps in the stabilization of Ni nanoparticles which are otherwise prone towards aerial oxidation. Further the nanoparticles retain their superparamagnetic nature and catalytic capacity. Ni-Polymer composite catalyses the reduction of 4-Nitrophenol to 4-Aminophenol very efficiently in presence of NaBH{sub 4}, attaining a complete conversion under some experimental conditions. Ni-Polymer composite is well characterized using UV–vis spectroscopy, FTIR, XPS, powder XRD, TGA, SEM and TEM. A detailed magnetic measurement using superconducting quantum interference device-vibrating sample magnetometer (SQUID-VSM) reveals superparamagnetic behaviour of the composite.

  17. Defects in codoped NiO with gigantic dielectric response

    Science.gov (United States)

    Wu, Ping; Ligatchev, Valeri; Yu, Zhi Gen; Zheng, Jianwei; Sullivan, Michael B.; Zeng, Yingzhi

    2009-06-01

    We combine first-principles, statistical, and phenomenological methods to investigate the electronic and dielectric properties of NiO and clarify the nature of the gigantic dielectric response in codoped NiO. Unlike previous models which are dependent on grain-boundary effects, our model based on small polaron hopping in homogeneous material predicts the dielectric permittivity (104-5) for heavily Li- and MD -codoped NiO (MD=Ti,Al,Si) . Furthermore, we reproduce the experimental trends in dielectric properties as a function of the dopants nature and their concentrations, as well as the reported activation energies for the relaxation in Li- and Ti-codoped NiO (0.308 eV or 0.153 eV depending on the Fermi-level position). In this study, we demonstrate that small polaron hopping on dopant levels is the dominant mechanism for the gigantic dielectric response in these codoped NiO.

  18. Expression analysis of CD63 in salivary neutrophils and the increased level of Streptococcus mutans in severe early childhood caries

    Directory of Open Access Journals (Sweden)

    Muhammad Luthfi

    2015-06-01

    Full Text Available Background: Severe early childhood caries (S-ECC and decay exfoliation filling teeth (def-t >6 is a destructive disease that afflicts teeth, including maxillary anterior teeth. In Indonesia, the prevalence of this disease is still high, for instance in Semarang 2007, the rate reached 90.5% in urban areas and 95.9% in rural areas for early childhood caries which is caused by Streptococcus mutans (S. mutans. Neutrophils are effector cells of innate immunity which become the main component of the very first line of defense against microbes. Purpose: This study analyzed the effect caused by the change of CD63 expression on the surface of salivary neutrophils and the increased level of S. mutans in S-ECC. Method: This study employs observational analytic and cross sectional approach by using T test analysis technique for forty cases of early childhood that had been divided into two groups, first group of twenty children positively diagnosed as S-ECC and second group of twenty children negatively diagnosed as the control group. The sample’s result of gargling with 1.5% NaCl was used for neutrophils isolation and analysis function of salivary neutrophils phagocytosis by using flow cytometry test, while the sample of saliva was used to isolate S. mutans and calculate the level of S. mutans. Result: The expression of CD63+ salivary neutrophils in S-ECC was lower (2.32% ± 0.57 than in caries-free (2.67% ± 0.46, while the level of S. mutans showed that the level was not higher than in S-ECC (9.78 ± 2.22x105 CFU/ml compared to in caries-free (5.13 ± 1.86x105 CFU/ml. Conclusion: The low expression of CD63 in salivary neutrophils can lead to the increased level of S. mutans in S-ECC.

  19. Low activation material design methodology for reduction of radio-active wastes of nuclear power plant

    International Nuclear Information System (INIS)

    Hasegawa, A.; Satou, M.; Nogami, S.; Kakinuma, N.; Kinno, M.; Hayashi, K.

    2007-01-01

    Most of the concrete shielding walls and pipes around a reactor pressure vessel of a light water reactor become low level radioactive waste at decommission phase because they contain radioactive nuclides by thermal-neutron irradiation during its operation. The radioactivity of some low level radioactive wastes is close to the clearance level. It is very desirable in terms of life cycle cost reduction that the radioactivity of those low level radioactive wastes is decreased below clearance level. In case of light water reactors, however, methodology of low activation design of a nuclear plant has not been established yet because the reactor is a large-scale facility and has various structural materials. The Objectives of this work are to develop low activation material design methodology and material fabrication for reduction of radio-active wastes of nuclear power plant such as reinforced concrete. To realize fabrication of reduced radioactive concrete, it is necessary to develop (1) the database of the chemical composition of raw materials to select low activation materials, (2) the tool for calculation of the neutron flux and the spectrum distribution of nuclear plants to evaluate radioactivity of reactor components, (3) optimization of material process conditions to produce the low activation cement and the low activation steels. Results of the data base development, calculation tools and trial production of low activation cements will be presented. (authors)

  20. Enhanced constitutive invasion activity in human nontumorigenic keratinocytes exposed to a low level of barium for a long time.

    Science.gov (United States)

    Thang, Nguyen D; Yajima, Ichiro; Ohnuma, Shoko; Ohgami, Nobutaka; Kumasaka, Mayuko Y; Ichihara, Gaku; Kato, Masashi

    2015-02-01

    We have recently demonstrated that exposure to barium for a short time (≤4 days) and at a low level (5 µM = 687 µg/L) promotes invasion of human nontumorigenic HaCaT cells, which have characteristics similar to those of normal keratinocytes, suggesting that exposure to barium for a short time enhances malignant characteristics. Here we examined the effect of exposure to low level of barium for a long time, a condition mimicking the exposure to barium through well water, on malignant characteristics of HaCaT keratinocytes. Constitutive invasion activity, focal adhesion kinase (FAK) protein expression and activity, and matrix metalloproteinase 14 (MMP14) protein expression in primary cultured normal human epidermal keratinocytes, HaCaT keratinocytes, and HSC5 and A431 human squamous cell carcinoma cells were augmented following an increase in malignancy grade of the cells. Constitutive invasion activity, FAK phosphorylation, and MMP14 expression levels of HaCaT keratinocytes after treatment with 5 µM barium for 4 months were significantly higher than those of control untreated HaCaT keratinocytes. Taken together, our results suggest that exposure to a low level of barium for a long time enhances constitutive malignant characteristics of HaCaT keratinocytes via regulatory molecules (FAK and MMP14) for invasion. © 2013 Wiley Periodicals, Inc.

  1. Rust Layer Formed on Low Carbon Weathering Steels with Different Mn, Ni Contents in Environment Containing Chloride Ions

    Directory of Open Access Journals (Sweden)

    Gui-qin FU

    2016-11-01

    Full Text Available The rusting evolution of low carbon weathering steels with different Mn, Ni contents under a simulated environment containing chloride ions has been investigated to clarify the correlation between Mn, Ni and the rust formed on steels. The results show that Mn contents have little impact on corrosion kinetics of experimental steels. Content increase of Ni both enhances the anti-corrosion performance of steel substrate and the rust. Increasing Ni content is beneficial to forming compact rust. Semi-quantitative XRD phase analysis shows that the quantity ratio of α/γ*(α-FeOOH/(γ-FeOOH+Fe3O4 decreases as Mn content increases but it increases as Ni content increases. Ni enhances rust layer stability but Mn content exceeding 1.06 wt.% is disadvantageous for rust layer stability. The content increase of Mn does not significantly alter the parameters of the polarization curve. However, as Ni contents increases, Ecorr has shifted to the positive along with decreased icorr values indicating smaller corrosion rate especially as Ni content increases from 0.42 wt.% to 1.50 wt.%.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.12844

  2. Highly active Ni/Y-doped ZrO{sub 2} catalysts for CO{sub 2} methanation

    Energy Technology Data Exchange (ETDEWEB)

    Takano, H., E-mail: takano_hi@hitachizosen.co.jp [Hitachi Zosen Corporation, Kashiwa, 277-8515 (Japan); Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, 060-8628 (Japan); Kirihata, Y.; Izumiya, K.; Kumagai, N. [Hitachi Zosen Corporation, Kashiwa, 277-8515 (Japan); Habazaki, H., E-mail: habazaki@eng.hokudai.ac.jp [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, 060-8628 (Japan); Division of Applied Chemistry & Frontier Chemistry Center, Faculty of Engineering, Hokkaido University, Sapporo, 060-8628 (Japan); Hashimoto, K. [Tohoku Institute of Technology, Sendai, 277-8515 (Japan)

    2016-12-01

    Highlights: • The Ni/Y-doped ZrO{sub 2} catalysts show highly catalytic activity for CO{sub 2} methanation. • Bidentate carbonate is a major adsorption spice on the Ni/Y-doped ZrO{sub 2} catalysts. • The oxide support of t-ZrO{sub 2} and/or c-ZrO{sub 2} with oxygen vacancies plays a key role. - Abstract: The catalytic methanation of CO{sub 2} was carried out on Ni catalysts supported on Y-doped ZrO{sub 2} with various Y{sup 3+} concentrations and Ni/(Zr + Y) molar ratio = 1. The catalysts were characterized by X-ray diffraction, scanning transmission electron microscopy, specific surface area, temperature-programmed desorption of CO{sub 2}, and temperature-programmed reaction. In addition, operando diffuse-reflectance infrared Fourier-transform spectroscopy (DRIFT) was used to identify the adsorbed reaction intermediate. Catalysts supported on Y-doped ZrO{sub 2} show higher catalytic activity than the catalyst on Y-free ZrO{sub 2} with a monoclinic ZrO{sub 2} phase. The catalytic activity is also dependent upon the Y{sup 3+} concentration, and the highest activity was obtained for the catalyst with a Y/(Zr + Y) molar ratio of 0.333, which consists mainly of fcc Ni and cubic ZrO{sub 2} phase. Y{sup 3+} doping into ZrO{sub 2} introduces oxygen vacancies, which play an important role in enhancing the catalytic activity. The operando DRIFT study reveals that a CO adsorption intermediate is absent, and bidentate carbonate is an important intermediate for CH{sub 4} formation.

  3. Cobalt internal standard for Ni to assist the simultaneous determination of Mo and Ni in plant materials by high-resolution continuum source graphite furnace atomic absorption spectrometry employing direct solid sample analysis.

    Science.gov (United States)

    de Babos, Diego Victor; Bechlin, Marcos André; Barros, Ariane Isis; Ferreira, Edilene Cristina; Gomes Neto, José Anchieta; de Oliveira, Silvana Ruella

    2016-05-15

    A new method is proposed for the simultaneous determination of Mo and Ni in plant materials by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS), employing direct solid sample analysis (DSS) and internal standardization (IS). Cobalt was used as internal standard to minimize matrix effects during Ni determinations, enabling the use of aqueous standards for calibration. Correlation coefficients for the calibration curves were typically better than 0.9937. The performance of the method was checked by analysis of six plant certified reference materials, and the results for Mo and Ni were in agreement with the certified values (95% confidence level, t-test). Analysis was made of different types of plant materials used as renewable sources of energy, including sugarcane leaves, banana tree fiber, soybean straw, coffee pods, orange bagasse, peanut hulls, and sugarcane bagasse. The concentrations found for Mo and Ni ranged from 0.08 to 0.63 ng mg(-1) and from 0.41 to 6.92 ng mg(-1), respectively. Precision (RSD) varied from 2.1% to 11% for Mo and from 3.7% to 10% for Ni. Limits of quantification of 0.055 and 0.074 ng were obtained for Mo and Ni, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Comparison of reduction agents in the synthesis of infinite-layer LaNiO{sub 2} films

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Ai [Department of Applied Physics, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Koganei, Tokyo 184-8588 (Japan); Research Fellow of the Japan Society for the Promotion of Science, Ichiban-cho 8, Chiyoda, Tokyo 102-8472 (Japan); Manabe, Takaaki [National Institute of Advanced Industrial Science and Technology (AIST), Higashi 1-1-1, Tsukuba, Ibaraki 305-8565 (Japan); Naito, Michio, E-mail: minaito@cc.tuat.ac.jp [Department of Applied Physics, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Koganei, Tokyo 184-8588 (Japan)

    2014-11-15

    Highlights: • Reduction agents were compared from a viewpoint of the facility for topotactic reduction of LaNiO{sub 3} to LaNiO{sub 2} films. • TiH{sub 2} and CaH{sub 2} yielded infinite-layer LaNiO{sub 2} with low and metallic resistivity. • H{sub 2} released from metal hydrides plays a dominant role in the topotactic reduction. - Abstract: Reduction agents, such as activated carbon, TiH{sub 2}, and CaH{sub 2}, were compared from a viewpoint of the facility for the topotactic reduction of LaNiO{sub 3} to LaNiO{sub 2} films. Activated carbon did not yield infinite-layer LaNiO{sub 2} whereas both of TiH{sub 2} and CaH{sub 2} yielded infinite-layer LaNiO{sub 2} with low resistivity (∼1 mΩ cm at 300 K) as well as metallic behavior down to 70 K. Thermal desorption spectroscopy indicated that H{sub 2} released from metal hydrides plays a dominant role in the topotactic reduction.

  5. High-level physical activity in childhood seems to protect against low back pain in early adolescence.

    Science.gov (United States)

    Wedderkopp, N; Kjaer, P; Hestbaek, L; Korsholm, L; Leboeuf-Yde, C

    2009-02-01

    The evidence on the impact of physical activity on back pain in children and adolescents has been contradicting. It has also been shown that the physical activity cannot accurately be estimated in children using questionnaires. The aim of this study was to establish if physical activity in childhood had any impact on back pain reporting in early adolescence (3 years later), using an objective instrumental measurement of physical activity. Prospective cohort study. Representative random sample of Danish children from the city of Odense sampled at age 9 years and followed-up at age 12 years. The 1-month period prevalence of back pain (neck pain, mid back pain, and low back pain) was established using a structured interview. Physical activity was assessed with the MTI-accelerometer. The accelerometer provides a minute-by-minute measure of the physical activity performed. An overall measure of physical activity and time spent in high activity were studied in relation to back pain using logistic regression. The analyses were performed on the total sample and then stratified on back pain (yes/no) at baseline. High physical activity (HPA) levels seem to protect against future low back pain and appear to actually "treat" and reduce the odds of future mid back pain. When comparing the least active children to the most active children, the least active had a multivariate odds ratio of 3.3 of getting low back pain and 2.7 of getting mid back pain 3 years later. When stratified on back pain at baseline, this effect on mid back pain was especially noticeable in children who had had mid back pain already at baseline, with an odds ratio of 7.2. HPA in childhood seems to protect against low back pain and mid back pain in early adolescence. Larger prospective studies with repetitive follow-ups and preferably intervention studies should be performed, to see if these findings can be reproduced.

  6. Electrodeposited synthesis of self-supported Ni-P cathode for efficient electrocatalytic hydrogen generation

    Directory of Open Access Journals (Sweden)

    Ruixian Wu

    2016-06-01

    Full Text Available One of the key challenges for electrochemical water splitting is the development of low-cost and efficient hydrogen evolution cathode. In this work, a self-supported Ni-P cathode was synthesized by a facile electrodeposition method. The composition and morphology were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy. The Ni-P cathode performed low onset over-potential, good catalytic activity and long-term stability under neutral and alkaline conditions. The mechanism of Ni-P electrode for hydrogen production was discussed by electrochemical impedance spectroscopy. The excellent performance of Ni-P cathode was mainly attributed to the synergistic effect of phosphate anions and the self-supported feature.

  7. Effect of carbon content on microstructure and mechanical properties of hot-rolled low carbon 12Cr-Ni stainless steel

    International Nuclear Information System (INIS)

    Zheng, H.; Ye, X.N.; Li, J.D.; Jiang, L.Z.; Liu, Z.Y.; Wang, G.D.; Wang, B.S.

    2010-01-01

    Research highlights: → Hot-rolled ultra low carbon martensite is characterized by dislocation cells substructure. → The formation of dislocation cells is attributed to high Ms and low interstitial atoms content. → Hot-rolled ultra low carbon 12Cr-Ni stainless steel has excellent impact toughness. → Delta ferrite deteriorates the impact toughness of hot-rolled 12Cr-Ni stainless steel. - Abstract: 12Cr-Ni stainless steels containing different carbon contents from 0.004 wt.% to 0.034 wt.% were hot-rolled and air-cooled. Their corresponding microstructures were observed with optical microscope and transmission electron microscope, and the Vickers hardness, tensile and impact tests were also carried out. It was found that the martensitic morphology was significantly influenced by carbon content. The as-received ultra low carbon martensite in the steel containing 0.004 wt.% C is characterized by dislocation cells substructure. The formation of dislocation cells is attributed to high martensite finishing point (above 400 deg. C) and low interstitial atoms content. On the other hand, the martensite in the steel containing 0.034 wt.% C consists mainly of typical martensite laths because of low martensite finishing point and high interstitial atoms content which hinder dislocation motion. Furthermore, carbon content has an evident effect on the mechanical properties of 12Cr-Ni steels. The hardness and strength of the as-received steels increase with an increase in carbon content, but their elongation and impact toughness decrease with the carbon content. The steel containing 0.004 wt.% C has excellent impact toughness due to the ultra low carbon content in the martensite composed of dislocation cells.

  8. Effect of Ni on the characteristics and hydrogenation activity of sulfide Mo/{gamma}-Al{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Schachtl, E.; Wuttke, E.; Gutierrez, O.Y.; Lercher, J.A. [Technische Univ. Muenchen, Garching (Germany). Dept. of Chemistry and Catalysis Research Center

    2012-07-01

    The hydrogenation of phenanthrene was explored on sulfide Mo/{gamma}-Al{sub 2}O{sub 3} catalysts promoted with increasing concentrations of Ni. The characterization of the materials was done by N{sub 2}-physisorption, X-ray diffraction, transmission electron microscopy, temperature programmed sulfidation and NO adsorption experiments. Increasing loading of Ni improves the dispersion of MoS{sub 2} species; however, at Ni/(Mo+Ni) molar ratio higher than 0.5, segregation of Ni-sulfides is observed. The presence of Ni also facilitates the sulfidation of oxidic catalyst precursors by lowering the reduction temperature of Mo species. In the sulfide catalysts, Ni changes the structure of MoS{sub 2} leading to shorter slabs with higher stacking degree than on Mo/{gamma}-Al{sub 2}O{sub 3}, and increases the concentration of coordinatively unsaturated sites. The kinetic results (increased hydrogenation rate and changed reaction network in the presence of Ni) suggest that a highly active kind of active site is created by Ni promotion. (orig.)

  9. Catalytic Activity of Urchin-like Ni nanoparticles Prepared by Solvothermal Method for Hydrogen Evolution Reaction in Alkaline Solution

    International Nuclear Information System (INIS)

    Abbas, Syed Asad; Iqbal, Muhammad Ibrahim; Kim, Seong-Hoon; Jung, Kwang-Deog

    2017-01-01

    Highlights: • Urchin-like Ni is prepared in solvothermal reaction. • Urchin-like Ni is formed via Ni(OH) 2 aggregates in ethanol and oleylamine. • Exchange current density of urchin-like Ni is 0.191 mA cm −2 . • Urchin-like Ni exceeds the catalytic performance of commercial Pt/C in HER. - Abstract: Ni nanoparticles with different morphologies were synthesized for hydrogen evolution reaction (HER) in alkaline solution. Here, Ni(acac) 2 was converted into Ni metal nanoparticles in solvothermal reactions with simple alcohols and oleylamine (OAm). The morphology of the resulting Ni nanoparticles was dependent mainly on the OAm/Ni molar ratio in alcohol solvent. Aggregates of spherical Ni nanoparticles (NiEt-OAm1) were observed at the OAm/Ni molar ratio of 1.0, whereas two echinoid Ni nanoparticles (NiEt-OAm4 and NiEt-OAm6) could be prepared in ethanol at the OAm/Ni molar ratios of 4.0 and 6.0. Ni(OH) 2 formed in ethanol during a reaction time of 5 h was then reduced into echinoid Ni nanoparticles after 8 h. Echinoid Ni nanoparticles were formed by atomic addition on the tops of the multipod Ni particles formed via Ni(OH) 2 /NiO aggregates. Webbed feet-like particles (NiIPA-OAm4) with plate edges were also observed in isopropanol under the same reaction conditions. The catalytic activities of the prepared Ni nanoparticles for the hydrogen evolution reaction were evaluated in alkaline solution. The NiEt-OAm4 with urchin-like morphology was much more active than the NiIPA-OAm4 with webbed feet-like morphology. The exchange current density of Ni catalysts was increased with increasing the OAm/Ni molar ratio. The NiEt-OAm6 exhibited an exchange current of 0.191 mA cm −2 and the NiEt-OAm4 exceeded electrocatalytic performance of a commercial Pt catalysts (40% Pt on Vulcan XC 72) in a stability test for 100 kiloseconds at −1.5 V (vs. Hg/HgO) in 1.0 M NaOH due to its high stability.

  10. Moessbauer of phase separation in FeNi multilayers under ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, L.; Paesano, A.; Brueckman, M.E. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica; Scorzelli, R.B.; Dominguez, A.B. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Shinjo, T.; Ono, T.; Hosoito, N. [Kyoto Univ. (Japan). Inst. for Chemical Research

    1997-01-01

    We investigated the effect of noble gas irradiation (He, Ne, Ar and Xe) on the Fe-Ni multilayers with a very thin modulation and nominal composition in the invar region Fe{sub 0.63} Ni{sub 0.37}. The evaluation of the formation/stability of the Fe-Ni phases formed under irradiation with different ions and doses was followed by conversion electron Moessbauer spectroscopy (CEMS). (author). 21 refs., 4 figs., 2 tabs.; e-mail: scorza at novell.cat.cbpf.br.

  11. Low-level viremia and proviral DNA impede immune reconstitution in HIV-1-infected patients receiving highly active antiretroviral therapy

    DEFF Research Database (Denmark)

    Ostrowski, Sisse R; Katzenstein, Terese L; Thim, Per T.

    2005-01-01

    Immunological and virological consequences of low-level viremia in human immunodeficiency virus (HIV) type 1-infected patients receiving highly active antiretroviral therapy (HAART) remain to be determined....

  12. Electrochemical preparation and characteristics of Ni-Co-LaNi5 composite coatings as electrode materials for hydrogen evolution

    International Nuclear Information System (INIS)

    Wu Gang; Li Ning; Dai Changsong; Zhou Derui

    2004-01-01

    Electrocatalytic activity for the hydrogen evolution reaction on Ni-Co-LaNi 5 composite electrodes prepared by electrochemical codeposition technique was evaluated. The relationship between the current density for hydrogen evolution reaction and the amount of LaNi 5 particles in Ni-Co baths is like the well-known 'volcano plot'. The Surface morphology and microstructure of Ni-Co-LaNi 5 coatings were determined by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD). The kinetic parameters were determined from electrochemical steady-state Tafel polarization and electrochemical impedance spectroscopy technology in 1 M NaOH solution. The values obtained for the apparent energies of activation are 32.48, 46.29 and 57.03 kJ mol -1 for the Ni-Co-LaNi 5 , Ni-Co and Ni electrodes, respectively. The hydrogen evolution reaction on Ni-Co-LaNi 5 proceeds via Volmer-Tafel reaction route with the mixed rate determining characteristics. The composite coating Ni-Co-LaNi 5 is catalytically more active than Ni and Ni-Co electrodes due to the increase in its real surface areas and the decrease in the apparent free energy of activation caused by the electrocatalytic synergistic effect of the Ni-Co alloys and the hydrogen storage intermetallic particles on the electrode surface

  13. Acoustic properties of TiNiMoFe base alloys

    International Nuclear Information System (INIS)

    Gyunter, V.Eh.; Chernyshev, V.I.; Chekalkin, T.L.

    2000-01-01

    The regularity of changing the acoustic properties of the TiNi base alloys in dependence on the alloy composition and impact temperature is studied. It is shown that the oscillations of the TiNiMoFe base alloys within the temperature range of the B2 phase existence and possible appearance of the martensite under the load differ from the traditional materials oscillations. After excitation of spontaneous oscillations within the range of M f ≤ T ≤ M d there exists the area of long-term and low-amplitude low-frequency acoustic oscillations. It is established that free low-frequency oscillations of the TH-10 alloy sample are characterized by the low damping level in the given temperature range [ru

  14. Electroless Ni-Mo-P diffusion barriers with Pd-activated self-assembled monolayer on SiO2

    International Nuclear Information System (INIS)

    Liu Dianlong; Yang Zhigang; Zhang Chi

    2010-01-01

    Ternary Ni-based amorphous films can serve as a diffusion barrier layer for Cu interconnects in ultralarge-scale integration (ULSI) applications. In this paper, electroless Ni-Mo-P films deposited on SiO 2 layer without sputtered seed layer were prepared by using Pd-activated self-assembled monolayer (SAM). The solutions and operating conditions for pretreatment and deposition were presented, and the formation of Pd-activated SAM was demonstrated by XPS (X-ray photoelectron spectroscopy) analysis and BSE (back-scattered electron) observation. The effects of the concentration of Na 2 MoO 4 added in electrolytes, pH value, and bath temperature on the surface morphology and compositions of Ni-Mo-P films were investigated. The microstructures, diffusion barrier property, electrical resistivity, and adhesion were also examined. Based on the experimental results, the Ni-Mo-P alloys produced by using Pd-activated SAM had an amorphous or amorphous-like structure, and possessed good performance as diffusion barrier layer.

  15. Gram-Scale Synthesis of Highly Active and Durable Octahedral PtNi Nanoparticle Catalysts for Proton Exchange Membrane Fuel Cell

    DEFF Research Database (Denmark)

    Choi, Juhyuk; Jang, Jue-Hyuk; Roh, Chi-Woo

    2018-01-01

    for the commercialization of PEMFCs. In this study, we focus on gram-scale synthesis of octahedral PtNi nanoparticles with Pt overlayers (PtNi@Pt) supported on the carbon, resulting in enhanced catalytic activity and durability. Such PtNi@Pt catalysts show high mass activity (1.24 A mgPt−1) at 0.9 V (vs RHE) for the ORR......Proton exchange membrane fuel cells (PEMFC) are regarded as a promising renewable energy source for a future hydrogen energy society. However, highly active and durable catalysts are required for the PEMFCs because of their intrinsic high overpotential at the cathode and operation under the acidic...... condition for oxygen reduction reaction (ORR). Since the discovery of the exceptionally high surface activity of Pt3Ni(111), the octahedral PtNi nanoparticles have been synthesized and tested. Nonetheless, their milligram-scale synthesis method and poor durability make them unsuitable...

  16. Radiation damage buildup and dislocation evolution in Ni and equiatomic multicomponent Ni-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Levo, E. [Department of Physics, P.O. Box 43, FIN-00014, University of Helsinki (Finland); Granberg, F., E-mail: fredric.granberg@helsinki.fi [Department of Physics, P.O. Box 43, FIN-00014, University of Helsinki (Finland); Fridlund, C.; Nordlund, K. [Department of Physics, P.O. Box 43, FIN-00014, University of Helsinki (Finland); Djurabekova, F. [Department of Physics, P.O. Box 43, FIN-00014, University of Helsinki (Finland); Helsinki Institute of Physics, P.O. Box 43, FIN-00014, University of Helsinki (Finland)

    2017-07-15

    Single-phase multicomponent alloys of equal atomic concentrations (“equiatomic”) have proven to exhibit promising mechanical and corrosion resistance properties, that are sought after in materials intended for use in hazardous environments like next-generation nuclear reactors. In this article, we investigate the damage production and dislocation mobility by simulating irradiation of elemental Ni and the alloys NiCo, NiCoCr, NiCoFe and NiFe, to assess the effect of elemental composition. We compare the defect production and the evolution of dislocation networks in the simulation cells of two different sizes, for all five studied materials. We find that the trends in defect evolution are in good agreement between the different cell sizes. The damage is generally reduced with increased alloy complexity, and the dislocation evolution is specific to each material, depending on its complexity. We show that increasing complexity of the alloys does not always lead to decreased susceptibility to damage accumulation under irradiation. We show that, for instance, the NiCo alloy behaves very similarly to Ni, while presence of Fe or Cr in the alloy even as a third component reduces the saturated level of damage substantially. Moreover, we linked the defect evolution with the dislocation transformations in the alloys. Sudden drops in defect number and large defect fluctuations from the continuous irradiation can be explained from the dislocation activity.

  17. An Asymmetric Supercapacitor Based on Activated Porous Carbon Derived from Walnut Shells and NiCo₂O₄ Nanoneedle Arrays Electrodes.

    Science.gov (United States)

    Wang, Wei; Qi, Jiqiu; Sui, Yanwei; He, Yezeng; Meng, Qingkun; Wei, Fuxiang; Jin, Yunxue

    2018-08-01

    A facile method was utilized to convert a common biomass of walnut shells into activated porous carbon by carbonization and activation with nitricacid treatment. The obtained activated carbon (WSs-2) exhibited excellent electrochemical performance with high specific capacitance of 137 F · g-1 at 1 A · g-1 and super cycling performance of 96% capacitance retention at 5 A · g-1 after 5000 cycles. In addition, NiCo2O4 nanoneedle arrays with good electrochemical properties were successfully prepared by a simple hydrothermal method. An aqueous asymmetric supercapacitor (ASC) device based on WSs-2 and NiCo2O4 was assembled, which delivered 21 Wh · kg-1 at a power density of 424.5 W · kg-1, and maintained 19 Wh · kg-1 at power density of 4254 W · kg-1 as well as excellent cycling stability of 99.3% capacitance retention after 5000 cycles at 4 A · g-1. Through this method, low-cost, environmentally friendly and large-scale carbon materials can be fabricated and applied in supercapacitor electrodes.

  18. Physical Activity in Public Parks of High and Low Socioeconomic Status in Colombia Using Observational Methods.

    Science.gov (United States)

    Camargo, Diana Marina; Ramírez, Paula Camila; Quiroga, Vanesa; Ríos, Paola; Férmino, Rogério César; Sarmiento, Olga L

    2018-03-28

    Public parks are an important resource for the promotion of physical activity (PA). This is the first study in Colombia and the fourth in Latin America to describe the characteristics of park users and their levels of PA using objective measures. A systematic observation assessed sex, age, and the level of PA of users of 10 parks in an intermediate-size city in Colombia, classified in low (5 parks) and high (5 parks) socioeconomic status (SES). A total of 10 daily observations were conducted, in 5 days of the week during 3 periods: morning, afternoon, and evening. In total, 16,671 observations were completed, recording 46,047 users. A higher number of users per park, per day, were recorded in high SES (1195) versus low SES (647). More men were observed in low-SES than high-SES parks (70.1% vs 54.2%), as well as more children were observed in low-SES than high-SES parks (30.1% vs 15.9%). Older adults in high-SES parks were more frequent (9.5% vs 5.2%). Moderate to vigorous PA was higher in low-SES parks (71.7% vs 63.2%). Low-SES parks need more green spaces, walk/bike trails, and areas for PA. All parks need new programs to increase the number of users and their PA level, considering sex, age group, and period of the week.

  19. Low cost RISC implementation of intelligent ultra fast charger for Ni-Cd battery

    International Nuclear Information System (INIS)

    Petchjatuporn, Panom; Sirisuk, Phaophak; Khaehintung, Noppadol; Sunat, Khamron; Wicheanchote, Phinyo; Kiranon, Wiwat

    2008-01-01

    This paper presents a low cost reduced instruction set computer (RISC) implementation of an intelligent ultra fast charger for a nickel-cadmium (Ni-Cd) battery. The charger employs a genetic algorithm (GA) trained generalized regression neural network (GRNN) as a key to ultra fast charging while avoiding battery damage. The tradeoff between mean square error (MSE) and the computational burden of the GRNN is addressed. Besides, an efficient technique is proposed for estimation of a radial basis function (RBF) in the GRNN. Hardware realization based upon the techniques is discussed. Experimental results with commercial Ni-Cd batteries reveal that while the proposed charger significantly reduces the charging time, it scarcely deteriorates the battery energy storage capability when compared with the conventional charger

  20. Low cost RISC implementation of intelligent ultra fast charger for Ni-Cd battery

    Energy Technology Data Exchange (ETDEWEB)

    Petchjatuporn, Panom; Khaehintung, Noppadol [Department of Control and Instrumentation Engineering, Faculty of Engineering, Mahanakorn University of Technology, Bangkok 10530 (Thailand); Sirisuk, Phaophak; Sunat, Khamron [Department of Computer Engineering, Faculty of Engineering, Mahanakorn University of Technology, Bangkok 10530 (Thailand); Wicheanchote, Phinyo [Test Engineering Department, Sanmina-SCI Systems Co. Ltd. (Thailand); Kiranon, Wiwat [Department of Telecommunication Engineering, Faculty of Engineering, King Mongkut' s Institue of Technology, Ladkrabang, Bangkok 10520 (Thailand)

    2008-02-15

    This paper presents a low cost reduced instruction set computer (RISC) implementation of an intelligent ultra fast charger for a nickel-cadmium (Ni-Cd) battery. The charger employs a genetic algorithm (GA) trained generalized regression neural network (GRNN) as a key to ultra fast charging while avoiding battery damage. The tradeoff between mean square error (MSE) and the computational burden of the GRNN is addressed. Besides, an efficient technique is proposed for estimation of a radial basis function (RBF) in the GRNN. Hardware realization based upon the techniques is discussed. Experimental results with commercial Ni-Cd batteries reveal that while the proposed charger significantly reduces the charging time, it scarcely deteriorates the battery energy storage capability when compared with the conventional charger. (author)

  1. Long-term management of wastes resulting from dismantling operations. Storing the very low-level activity wastes at Morvilliers

    International Nuclear Information System (INIS)

    Duret, F.; Dutzer, M.; Beranger, V.; Lecoq, P.

    2003-01-01

    Extension of dismantling operations in France in the years to come poses the question of availability of long-term waste facility. Large amount of such wastes will be produced after progressive shutdown of the 58 pressurized water reactors now in operation, not before 2010. However, France is already confronted with dismantling of 9 power reactors (6 of which of gas cooled graphite type), the first reprocessing plant at Marcoule, as well as, dismantling of other installations, for instance the CEA reactors or laboratories. The systems of processing the dismantling waste are not different from those used for wastes resulting from nuclear operations. For the high-level or long-term intermediate level activity disposal the debates must start by 2006, as based on the results of the research conducted according to different provisions of the December 30, 1991 law. These wastes represent however small amounts from the dismantling (around 2000 t for the 9 reactors at shutdown) and they will be stored until a decision will be made. A specific storing system should be implemented by 2008-2010 for the graphite wastes (around 23,000 t) which contain significant amount of long-lived radioelements, although their gross activity is low. But the most significant amount will come from low-level or intermediate-level of short lifetime or from wastes of very low activity. The first category is stored at Storage Center at Aube (CSA), its capacity being of 1,000,000 m 3 of drums. The total volume stored by the end of 2002 amounted 136,500 m 3 with an annual delivering of 12-15,000 m 3 at design rate of 30,000 m 3 /y. This center will be able to absorb the flux increase resulting from dismantling of the decommissioned nuclear installations (around 50,000 t from the dismantling of the 9 power reactor). The Center at Aube can be also adapted for storing wastes of large sizes as for instance the lid of the reactor vessel. According to the French regulation, the wastes produced within a

  2. NiFe{sub 2}O{sub 4}/activated carbon nanocomposite as magnetic material from petcoke

    Energy Technology Data Exchange (ETDEWEB)

    Briceño, Sarah, E-mail: sbriceno@ivic.gob.ve [Laboratorio de Física de la Materia Condensada, Centro de Física, Instituto Venezolano de Investigaciones Científicas IVIC, Apartado 20632, Caracas 1020-A (Venezuela, Bolivarian Republic of); Brämer-Escamilla, W., E-mail: wbramer@ivic.gob.ve [Laboratorio de Física de la Materia Condensada, Centro de Física, Instituto Venezolano de Investigaciones Científicas IVIC, Apartado 20632, Caracas 1020-A (Venezuela, Bolivarian Republic of); Silva, P. [Laboratorio de Física de la Materia Condensada, Centro de Física, Instituto Venezolano de Investigaciones Científicas IVIC, Apartado 20632, Caracas 1020-A (Venezuela, Bolivarian Republic of); García, J.; Del Castillo, H.; Villarroel, M. [Laboratorio de Cinética y Catálisis, Departamento de Química, Facultad de Ciencias, Universidad de Los Andes ULA, Mérida 5101-A (Venezuela, Bolivarian Republic of); Rodriguez, J.P. [Laboratorio de Microscopia Electrónica. Instituto de Estudios Científicos y Tecnológicos IDECYT. Apartado 47925 - Caracas 1041-A (Venezuela, Bolivarian Republic of); Ramos, M.A.; Morales, R. [Instituto Zuliano de Investigaciones Tecnológicas INZIT. Apdo. Postal 331. La Cañada-Maracaibo (Venezuela, Bolivarian Republic of); Diaz, Y. [Centro de Química, Instituto Venezolano de Investigaciones Científicas IVIC, Apartado 20632, Caracas 1020-A (Venezuela, Bolivarian Republic of)

    2014-06-01

    Nickel ferrite (NiFe{sub 2}O{sub 4}) was supported on activated carbon (AC) from petroleum coke (petcoke). Potassium hydroxide (KOH) was employed with petcoke to produce activated carbon. NiFe{sub 2}O{sub 4} were synthesized using PEG-Oleic acid assisted hydrothermal method. The structural and magnetic properties were determined using thermogravimetric and differential thermal analysis (TGA–DTA), X-ray diffraction (XRD), Fourier Transform Infrared (IR-FT), surface area (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). XRD analysis revealed the cubic spinel structure and ferrite phase with high crystallinity. IR-FT studies showed that chemical modification promoted the formation of surface oxygen functionalities. Morphological investigation by SEM showed conglomerates of spherical nanoparticles with an average particle size of 72 nm and TEM showed the formation of NiFe{sub 2}O{sub 4}/carbon nanofibers. Chemical modification and activation temperature of 800 °C prior to activation dramatically increased the BET surface area of the resulting activated carbon to 842.4 m{sup 2}/g while the sulfur content was reduced from 6 to 1%. Magnetic properties of nanoparticles show strong dependence on the particle size. - Highlights: • TEM showed the formation of NiFe{sub 2}O{sub 4}/carbon nanofibers. • Nanoparticles were supported on the activated carbon from petcoke. • Activation dramatically increased the BET surface area to 842 m{sup 2}/g. • Magnetic properties show strong dependence on the particle size. • Sulphur content was reduced from 6 to 1% with the petcoke activation.

  3. HER Catalytic Activity of Electrodeposited Ni-P Nanowires under the Influence of Magnetic Field

    Directory of Open Access Journals (Sweden)

    Hung-Bin Lee

    2013-01-01

    Full Text Available Nickel alloy electrodes both in plane and nanowire morphologies were fabricated by electrodeposition in sulfamate bath. With the increasing concentration of phosphorous acid in the electrolyte, the P content in the deposition increased accordingly. In the meantime, the grain refined and even became amorphous in microstructure as the P content was raised. For the nanowire electrode, vibrating sample magnetometer (VSM measurement showed that its coercivity was anisotropic and decreased with P-content. In addition, the easy axis for magnetization of the electrode was parallel to the axial direction of nanowire. The electrocatalytic activity measurement of the electrode in 0.5 M H2SO4 electrolyte showed that the nanowire electrode had higher activity than the plane one, and the alloying of P in Ni electrode raised its hydrogen evolution reaction (HER performance. The enhanced performance of nanowire electrode was attributed to the smaller and more uniform hydrogen bubbles generated in HER reaction. Finally, the applied magnetic field (3.2 T improved significantly the HER activity of Ni but not Ni-P electrode. By using nanowire morphology and applying magnetic field, the current density at −0.75 V HER stability test of the Ni electrode increased fourfold more than its plane counterpart.

  4. Ni-Nanocluster Modified Black TiO2 with Dual Active Sites for Selective Photocatalytic CO2 Reduction.

    Science.gov (United States)

    Billo, Tadesse; Fu, Fang-Yu; Raghunath, Putikam; Shown, Indrajit; Chen, Wei-Fu; Lien, Hsiang-Ting; Shen, Tzu-Hsien; Lee, Jyh-Fu; Chan, Ting-Shan; Huang, Kuo-You; Wu, Chih-I; Lin, M C; Hwang, Jih-Shang; Lee, Chih-Hao; Chen, Li-Chyong; Chen, Kuei-Hsien

    2018-01-01

    One of the key challenges in artificial photosynthesis is to design a photocatalyst that can bind and activate the CO 2 molecule with the smallest possible activation energy and produce selective hydrocarbon products. In this contribution, a combined experimental and computational study on Ni-nanocluster loaded black TiO 2 (Ni/TiO 2[Vo] ) with built-in dual active sites for selective photocatalytic CO 2 conversion is reported. The findings reveal that the synergistic effects of deliberately induced Ni nanoclusters and oxygen vacancies provide (1) energetically stable CO 2 binding sites with the lowest activation energy (0.08 eV), (2) highly reactive sites, (3) a fast electron transfer pathway, and (4) enhanced light harvesting by lowering the bandgap. The Ni/TiO 2[Vo] photocatalyst has demonstrated highly selective and enhanced photocatalytic activity of more than 18 times higher solar fuel production than the commercial TiO 2 (P-25). An insight into the mechanisms of interfacial charge transfer and product formation is explored. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Comparison of reduction agents in the synthesis of infinite-layer LaNiO2 films

    Science.gov (United States)

    Ikeda, Ai; Manabe, Takaaki; Naito, Michio

    2014-11-01

    Reduction agents, such as activated carbon, TiH2, and CaH2, were compared from a viewpoint of the facility for the topotactic reduction of LaNiO3 to LaNiO2 films. Activated carbon did not yield infinite-layer LaNiO2 whereas both of TiH2 and CaH2 yielded infinite-layer LaNiO2 with low resistivity (∼1 mΩ cm at 300 K) as well as metallic behavior down to 70 K. Thermal desorption spectroscopy indicated that H2 released from metal hydrides plays a dominant role in the topotactic reduction.

  6. Grain boundary diffusion and segregation of Ni in Cu

    International Nuclear Information System (INIS)

    Divinski, Sergiy; Ribbe, Jens; Schmitz, Guido; Herzig, Christian

    2007-01-01

    Grain boundary (GB) diffusion of 63 Ni in polycrystalline Cu was investigated by the radiotracer technique in an extended temperature interval from 476 to 1156K. The independent measurements in Harrison's C and B kinetic regimes resulted in direct data of the GB diffusivity D gb and of the so-called triple product P=s.δ.D gb (s and δ are the segregation factor and the diffusional GB width, respectively). Arrhenius-type temperature dependencies for both the D gb and P values were measured, resulting in the pre-exponential factors D gb 0 =6.93x10 -7 m 2 s -1 and P 0 =1.89x10 -16 m 3 s -1 and the activation enthalpies of 90.4 and 73.8kJmol -1 , respectively. Although Ni is completely soluble in Cu, it reveals a distinct but still moderate ability to segregate copper GBs with a segregation enthalpy of about -17kJmol -1

  7. Determination of standard Ghibbs free energy of formation of NiW sub 2 B sub 2 and activity of Ni-W binary system by EMF measurement. Kidenryokuho ni yoru NiW sub 2 B sub 2 no hyojun seisei Gibbs jiyu energy to Ni-W 2 seibunkei no katsuryo no sokutei

    Energy Technology Data Exchange (ETDEWEB)

    Kayama, Koichiro; Hashimoto, Yasuhiko; Suzuki, Kenji; Matsuo, Hideki (Himeji Inst. of Tech., Hyogo (Japan) Fukushin Electric Co., Ltd., Hyogo (Japan))

    1989-12-25

    NiW {sub 2} B {sub 2} (M phase), existing in trinary Ni-W-B system, was measured in standard Gibbs free energy (GF) of formation in the temperature range from 1273K to 1423K by an electromotive force method (EMF) with use of solid oxide electrolyte. First, oxide phase in equilibrium with three-phase M-W-Ni solid solution region was confirmed to be B {sub 2} O {sub 3}. Binary Ni-W system solid solution in equilibrium with M phase and W phase is constant in composition with Ni-16.4mo1%W in the above temperature range. WO {sub 2} and WO {sub 2.72} were actually measured in GF. As Ni-W solid solution is in equilibrium with WO {sub 2} and WO {sub 2.72}, binary Ni-W system was measured in activity by the EMF, and Ni-16.4mo1%W solid solution was calculated in GF of mixing by use of the above measured GF of WO {sub 2} and WO {sub 2.72}. Finally with use of sample in M-W-Ni solid solution region, M phase was calculated in GF by the EMF. The result of those calculations were expressed with experimental formulas. 19 refs., 10 figs., 3 tabs.

  8. Steam Reforming of CH4 Using Ni- Substituted Pyrochlore Catalysts

    Science.gov (United States)

    Haynes, Daniel J.

    less lanthanum at the surface. Comparing the XANES and EXAFS profiles for the supported and substituted Ni catalysts showed no detectable difference between the spectra, further confirming the Ni to be present as NiO after substitution. Activity testing found the NiO on the surface to be the active catalytic form. However, the Ni proved to be highly sensitive to sintering and oxidation by steam, especially under high pressures (1.8 MPa), which caused all catalysts to suffer irreversible activity loss. Low reaction pressures (0.23 MPa) elicited an activation effect in which the Ni initially lost activity, but then recovered to near equilibrium yields after nearly 10 hours time on stream. The activation was correlated with an increase in Ni particle size, as observed by XRD. It is speculated from similar behavior reported in the literature that ability to recovery activity was linked to a redox cycling of the Ni particles under reaction conditions, in which a small amount of the Ni was redistributed over the surface through the volatilization with steam, as well as the exsolution of the Sr from the structure which helped stabilize the Ni. A comparison of the supported and substituted forms of Ni showed the substituted form to have a weaker interaction with the pyrochlore surface, which is the likely cause for the rapid sintering and deactivation by steam. It was also found that the substitution of more Sr into the structure produced only strong basic sites, which resulted in a lower degree of activity loss and more stable activity under high pressure conditions (1.8 MPa) compared to the catalyst with less Sr. Carbon formation was not an issue for these materials, due to the rapid sintering and oxidation of the metal in-situ. Fitting the Ni particle size growth with time showed a parabolic relationship with growth proportional to time by the power 0.28. This value is close to results observed in the literature which indicates the Ni agglomerates via atomic migration.

  9. Joint influence of temperature and ions of metals on level of activity alkaline phosphatase the mucous membrane of intestines beluga, the starlet and their hybrid

    Directory of Open Access Journals (Sweden)

    D. A. Bednyakov

    2010-01-01

    Full Text Available In work joint influence of ions of bivalent metals (Mn, Fe, Co, Ni, Cu and Zn and temperatures on level of activity alkaline phosphatase mucous membrane beluga, starlet and their hybrid is shown. Dependence of response of enzyme on action of ions of metals according to their position in a periodic table of chemical elements is shown. The given dependence remains and at temperature change incubation, only at low temperatures the activating effect of metals being in the period beginning is maximum, and at high, is maximum inhibiting effect of metals being in the period end.

  10. Low Levels of Physical Activity and Sedentary Behavior in Adults with Intellectual Disabilities

    Directory of Open Access Journals (Sweden)

    Kelly Hsieh

    2017-12-01

    Full Text Available Adults with intellectual disabilities (ID are more likely to lead sedentary lifestyles and have low levels of physical activity (LLPA. The present study investigated the prevalence of reported LLPA and time spent watching TV in adults with ID and identified the associated factors for these behaviors. The proxy informants of 1618 adults with ID completed the surveys regarding their health behaviors. Multiple logistic regressions were employed for LLPA and multiple linear regressions for time spent watching TV. About 60% of adults with ID had LLPA and average time spent watching TV was 3.4 h a day. Some characteristics and health and function variables were identified as associated factors. While engaging in community activities and involvement in Special Olympics were inversely associated with LLPA, they were not associated with time spent watching TV. Attending day/educational programs or being employed were associated with spending less time watching TV. Findings highlight differential factors associated with LLPA versus TV-watching behavior in adults with ID. Hence, a key strategy aimed at increasing physical activity includes promoting participation in social and community activities, while targeted activities for reducing sedentary behavior might focus on providing day programs or employment opportunities for adults with ID.

  11. Highly Active PdNi/RGO/Polyoxometalate Nanocomposite Electrocatalyst for Alcohol Oxidation.

    Science.gov (United States)

    Hu, Jing; Wu, Xiaofeng; Zhang, Qingfan; Gao, Mingyan; Qiu, Haifang; Huang, Keke; Feng, Shouhua; Wang, Tingting; Yang, Ying; Liu, Zhelin; Zhao, Bo

    2018-02-27

    A PdNi/RGO/polyoxometalate nanocomposite has been successfully synthesized by a simple wet-chemical method. Characterizations such as transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction analysis, and X-ray photoelectron spectroscopy are employed to verify the morphology, structure, and elemental composition of the as-prepared nanocomposite. Inspired by the fast-developing fuel cells, the electrochemical catalytic performance of the nanocomposite toward methanol and ethanol oxidation in alkaline media is further tested. Notably, the nanocomposite exhibits excellent catalytic activity and long-term stability toward alcohol electrooxidation compared with the PdNi/RGO and commercial Pd/C catalyst. Furthermore, the electrochemical results reveal that the prepared nanocomposite is attractive as a promising electrocatalyst for direct alcohol fuel cells, in which the phosphotungstic acid plays a crucial role in enhancing the electrocatalytic activities of the catalyst.

  12. Effects of short-range order on electronic properties of Zr-Ni glasses as seen from low-temperature specific heat

    Science.gov (United States)

    Kroeger, D. M.; Koch, C. C.; Scarbrough, J. O.; McKamey, C. G.

    1984-02-01

    Measurements of the low-temperature specific heat Cp of liquid-quenched Zr-Ni glasses for a large number of compositions in the range from 55 to 74 at.% Zr revealed an unusual composition dependence of the density of states at the Fermi level, N(EF). Furthermore, for some compositions the variation of Cp near the superconducting transition temperature Tc indicated the presence of two superconducting phases, i.e., two superconducting transitions were detected. Comparison of the individual Tc's in phase-separated samples to the composition dependence of Tc for all of the samples suggests that amorphous phases with compositions near 60 and 66.7 at.% Zr occur. We discuss these results in terms of an "association model" for liquid alloys (due to Sommer), in which associations of unlike atoms with definite stoichiometries are assumed to exist in equilibrium with unassociated atoms. We conclude that in the composition range studied, associate clusters with the compositions Zr3Ni2 and Zr2Ni occur. In only a few cases are the clusters sufficiently large, compared with the superconducting coherence length, for separate superconducting transitions to be observed. The variation of N(EF) with composition is discussed, as well as the effects of this chemical short-range ordering on the crystallization behavior and glass-forming tendency.

  13. Effects of the Microstructure on Segregation behavior of Ni-Cr-Mo High Strength Low Alloy RPV Steel

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang Gyu; Wee, Dang Moon [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Kim, Min Chul; Lee, Bong Sang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-10-15

    SA508 Gr.4N Ni-Cr-Mo low alloy steel has an improved fracture toughness and strength, compared to commercial Mn-Mo-Ni low alloy RPV steel SA508 Gr.3. Higher strength and fracture toughness of low alloy steels could be achieved by adding Ni and Cr. So there are several researches on SA508 Gr.4N low alloy steel for a RPV application. The operation temperature and time of a reactor pressure vessel is more than 300 .deg. C and over 40 years. Therefore, in order to apply the SA508 Gr.4N low alloy steel for a reactor pressure vessel, it requires a resistance of thermal embrittlement in the high temperature range including temper embrittlement resistance. S. Raoul reported that the susceptibility to temper embrittlement was increasing a function of the cooling rate in SA533 steel, which suggests the martensitic microstructures resulting from increased cooling rates are more susceptible to temper embrittlement. However, this result has not been proved yet. So the comparison of temper embrittlement behavior was made between martensitic microstructure and bainitic microstructure with a viewpoint of boundary features in SA508 Gr.4N, which have mixture of tempered bainite/martensite. In this study, we have compared temper embrittlement behaviors of SA508 Gr.4N low alloy steel with changing volume fraction of martensite. The mechanical properties of these low alloy steels) were evaluated after a long-term heat treatment(450 .deg. C, 2000hr. Then, the images of the segregated boundaries were observed and segregation behavior was analyzed by AES. In order to compare the misorientation distributions of model alloys, grain boundary structures were measured with EBSD

  14. Magnetic Properties of FeNi-Based Thin Film Materials with Different Additives

    Directory of Open Access Journals (Sweden)

    Cai Liang

    2014-07-01

    Full Text Available This paper presents a study of FeNi-based thin film materials deposited with Mo, Al and B using a co-sputtering process. The existence of soft magnetic properties in combination with strong magneto-mechanical coupling makes these materials attractive for sensor applications. Our findings show that FeNi deposited with Mo or Al yields magnetically soft materials and that depositing with B further increases the softness. The out-of-plane magnetic anisotropy of FeNi thin films is reduced by depositing with Al and completely removed by depositing with B. The effect of depositing with Mo is dependent on the Mo concentration. The coercivity of FeNiMo and FeNiAl is reduced to less than a half of that of FeNi, and a value as low as 40 A/m is obtained for FeNiB. The surfaces of the obtained FeNiMo, FeNiAl and FeNiB thin films reveal very different morphologies. The surface of FeNiMo shows nano-cracks, while the FeNiAl films show large clusters and fewer nano-cracks. When FeNi is deposited with B, a very smooth morphology is obtained. The crystal structure of FeNiMo strongly depends on the depositant concentration and changes into an amorphous structure at a higher Mo level. FeNiAl thin films remain polycrystalline, even at a very high concentration of Al, and FeNiB films are amorphous, even at a very low concentration of B.

  15. Magnetic properties of FeNi-based thin film materials with different additives

    KAUST Repository

    Liang, C.

    2014-07-04

    This paper presents a study of FeNi-based thin film materials deposited with Mo, Al and B using a co-sputtering process. The existence of soft magnetic properties in combination with strong magneto-mechanical coupling makes these materials attractive for sensor applications. Our findings show that FeNi deposited with Mo or Al yields magnetically soft materials and that depositing with B further increases the softness. The out-of-plane magnetic anisotropy of FeNi thin films is reduced by depositing with Al and completely removed by depositing with B. The effect of depositing with Mo is dependent on the Mo concentration. The coercivity of FeNiMo and FeNiAl is reduced to less than a half of that of FeNi, and a value as low as 40 A/m is obtained for FeNiB. The surfaces of the obtained FeNiMo, FeNiAl and FeNiB thin films reveal very different morphologies. The surface of FeNiMo shows nano-cracks, while the FeNiAl films show large clusters and fewer nano-cracks. When FeNi is deposited with B, a very smooth morphology is obtained. The crystal structure of FeNiMo strongly depends on the depositant concentration and changes into an amorphous structure at a higher Mo level. FeNiAl thin films remain polycrystalline, even at a very high concentration of Al, and FeNiB films are amorphous, even at a very low concentration of B. 2014 by the authors.

  16. Low Amount of Salinomycin Greatly Increases Akt Activation, but Reduces Activated p70S6K Levels

    Directory of Open Access Journals (Sweden)

    Sungpil Yoon

    2013-08-01

    Full Text Available The present study identified a novel salinomycin (Sal-sensitization mechanism in cancer cells. We analyzed the signal proteins Akt, Jnk, p38, Jak, and Erk1/2 in cancer cell lines that had arrested growth following low amounts of Sal treatment. We also tested the signal molecules PI3K, PDK1, GSK3β, p70S6K, mTOR, and PTEN to analyze the PI3K/Akt/mTOR pathway. The results showed that Sal sensitization positively correlates with large reductions in p70S6K activation. Interestingly, Akt was the only signal protein to be significantly activated by Sal treatment. The Akt activation appeared to require the PI3K pathway as its activation was abolished by the PI3K inhibitors LY294002 and wortmannin. The Akt activation by Sal was conserved in the other cell lines analyzed, which originated from other organs. Both Akt activation and C-PARP production were proportionally increased with increased doses of Sal. In addition, the increased levels of pAkt were not reduced over the time course of the experiment. Co-treatment with Akt inhibitors sensitized the Sal-treated cancer cells. The results thereby suggest that Akt activation is increased in cells that survive Sal treatment and resist the cytotoxic effect of Sal. Taken together; these results indicate that Akt activation may promote the resistance of cancer cells to Sal.

  17. Low oxygen level increases proliferation and metabolic changes in bovine granulosa cells.

    Science.gov (United States)

    Shiratsuki, Shogo; Hara, Tomotaka; Munakata, Yasuhisa; Shirasuna, Koumei; Kuwayama, Takehito; Iwata, Hisataka

    2016-12-05

    The present study addresses molecular backgrounds underlying low oxygen induced metabolic changes and 1.2-fold change in bovine granulosa cell (GCs) proliferation. RNA-seq revealed that low oxygen (5%) upregulated genes associated with HIF-1 and glycolysis and downregulated genes associated with mitochondrial respiration than that in high oxygen level (21%). Low oxygen level induced high glycolytic activity and low mitochondrial function and biogenesis. Low oxygen level enhanced GC proliferation with high expression levels of HIF-1, VEGF, AKT, mTOR, and S6RP, whereas addition of anti-VEGF antibody decreased cellular proliferation with low phosphorylated AKT and mTOR expression levels. Low oxygen level reduced SIRT1, whereas activation of SIRT1 by resveratrol increased mitochondrial replication and decreased cellular proliferation with reduction of phosphorylated mTOR. These results suggest that low oxygen level stimulates the HIF1-VEGF-AKT-mTOR pathway and up-regulates glycolysis, which contributes to GC proliferation, and downregulation of SIRT1 contributes to hypoxia-associated reduction of mitochondria and cellular proliferation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Urinary nickel as bioindicator of workers' Ni exposure in a galvanizing plant in Brazil.

    Science.gov (United States)

    Oliveira, J P; de Siqueira, M E; da Silva, C S

    2000-01-01

    We measured urinary nickel (U-Ni) in ten workers (97 samples) from a galvanizing plant that uses nickel sulfate, and in ten control subjects (55 samples) to examine the association between occupational exposure to airborne Ni and Ni absorption. Samples from the exposed group were taken before and after the work shift on 5 successive workdays. At the same time airborne Ni (A-Ni) was measured using personal samplers. Ni levels in biological material and in the airborne were determined by a graphite furnace atomic absorption spectrometry validated method. In the control group the urine samples were collected twice a day, in the before and after the work shift, on 3 successive days. Ni exposure low to moderate was detected in all the examined places in the plant, the airborne levels varying between 2.8 and 116.7 micrograms/m3 and the urine levels, from samples taken postshift, between 4.5 and 43.2 micrograms/g creatinine (mean 14.7 micrograms/g creatinine). Significant differences in U-Ni creatinine were seen between the exposed and control groups (Student's t test, P galvanizing plants regardless of the day of the workweek on which the samples are collected.

  19. Inhibition of fungal growth with extreme low oxygen levels

    DEFF Research Database (Denmark)

    Nielsen, Per Væggemose; Haasum, Iben

    1998-01-01

    Fungal spoilage of foods is effectively controlled by removal of oxygen from the package, especially if this is combined with elevated carbon dioxide (CO2) levels. However, great uncertainty exist on just how low the residual oxygen levels in the package must be especially when carbon dioxide lev...... food with low CO2 levels. Active packaging with oxygen absorbers may be considered for these products. The packaging solution must also reflect the micro flora of the product.......Fungal spoilage of foods is effectively controlled by removal of oxygen from the package, especially if this is combined with elevated carbon dioxide (CO2) levels. However, great uncertainty exist on just how low the residual oxygen levels in the package must be especially when carbon dioxide...... Penicillia and Aspergilli were also inhibited by oxygen levels less than 0.5%, but less than 0.01% was required to efficiently inhibit these fungi. Most resistant to very low oxygen levels was the Fusarium species.These results shows that very low oxygen levels are required to avoid fungal growth in package...

  20. Computational studies of a paramagnetic planar dibenzotetraaza[14]annulene Ni(II) complex.

    Science.gov (United States)

    Rabaâ, Hassan; Khaledi, Hamid; Olmstead, Marilyn M; Sundholm, Dage

    2015-05-28

    A square-planar Ni(II) dibenzotetraaza[14]annulene complex substituted with two 3,3-dimethylindolenine groups in the meso positions has recently been synthesized and characterized experimentally. In the solid-state, the Ni(II) complex forms linear π-interacting stacks with Ni···Ni separations of 3.448(2) Å. Measurements of the temperature dependence of the magnetic susceptibility revealed a drastic change in the magnetic properties at a temperature of 13 K, indicating a transition from low-to-high spin states. The molecular structures of the free-base ligand, the lowest singlet, and triplet states of the monomer and the dimer of the Ni complex have been studied computationally using density functional theory (DFT) and ab initio correlation levels of theory. In calculations at the second-order Møller-Plesset (MP2) perturbation theory level, a large energy of 260 kcal mol(-1) was obtained for the singlet-triplet splitting, suggesting that an alternative explanation of the observed magnetic properties is needed. The large energy splitting between the singlet and triplet states suggests that the observed change in the magnetism at very low temperatures is due to spin-orbit coupling effects originating from weak interactions between the fine-structure states of the Ni cations in the complex. The lowest electronic excitation energies of the dibenzotetraaza[14]annulene Ni(II) complex calculated at the time-dependent density functional theory (TDDFT) levels are in good agreement with values deduced from the experimental UV-vis spectrum. Calculations at the second-order algebraic-diagrammatic construction (ADC(2)) level on the dimer of the meso-substituted 3,3-dimethylindolenine dibenzotetraaza[14] annulene Ni(II) complex yielded Stokes shifts of 85-100 nm for the lowest excited singlet states. Calculations of the strength of the magnetically induced ring current for the free-base 3,3-dimethylindolenine-substituted dibenzotetraaza[14]annulene show that the annulene

  1. The superexchange interactions and magnetic ordering in low-dimentional ludwigite Ni_5GeB_2O_1_0

    International Nuclear Information System (INIS)

    Sofronova, S.N.; Bezmaternykh, L.N.; Eremin, E.V.; Nazarenko, I.I.; Volkov, N.V.; Kartashev, A.V.; Moshkina, E.M.

    2016-01-01

    The ludwigite Ni_5Ge(BO_5)_2 belongs to a family of oxyborates which have low-dimensional subunits in the form of three-leg ladders unit structure. This material was studied by magnetic and thermodynamic measurements. Ni_5Ge(BO_5)_2 does not show full long-range magnetic order, but one goes into a partial ordering or spin-glass state at 87 K. The superexchange interactions were calculated in the framework of a simple indirect coupling model. Different models of magnetic structure of Ni_5Ge(BO_5)_2 and its unique magnetic behaviour was discussed. - Highlights: • The single crystals of Ni_5Ge(BO_5)_2 with a ludwigite structure were grown. • Magnetic and the specific heat measurements were performed. • The calculation of the exchange interactions shows a competition between interactions. • The magnetic behaviour corresponds to ions moments part freezing or spin-glass state. • We propose two models of magnetic ordering in Ni_5Ge(BO_5)_2.

  2. The peroxidase and oxidase-like activity of NiCo{sub 2}O{sub 4} mesoporous spheres: Mechanistic understanding and colorimetric biosensing

    Energy Technology Data Exchange (ETDEWEB)

    Su, Li, E-mail: suli@htu.edu.cn [Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University, Xinxiang, Henan 453007 (China); Henan Key Laboratory of Green Chemical Media and Reactions, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007 (China); Dong, Wenpei; Wu, Chengke; Gong, Yijun; Zhang, Yan; Li, Ling; Mao, Guojiang; Feng, Suling [Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University, Xinxiang, Henan 453007 (China); Henan Key Laboratory of Green Chemical Media and Reactions, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007 (China)

    2017-01-25

    The synthesized NiCo{sub 2}O{sub 4} mesoporous spheres (MS) displayed intrinsic peroxidase and oxidase-like activity were firstly reported. The catalytic mechanism of the oxidase-like activity of NiCo{sub 2}O{sub 4} MS was analyzed in detail using the electron spin resonance (ESR) method. It is found that NiCo{sub 2}O{sub 4} MS could directly oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) but did not produce {sup 1}O{sub 2} and ·OH. And the mechanism of the peroxidase-like activity of NiCo{sub 2}O{sub 4} MS was also verified that the oxidation of TMB stemmed from not only ·OH but also {sup 1}O{sub 2}. Based on the NiCo{sub 2}O{sub 4} MS showed excellent peroxidase-like activity over a broad temperature range, especially at normal body temperature, a detection tool was designed for glucose determination in diabetics' serum samples. And this detection method based on NiCo{sub 2}O{sub 4} MS gave a lower limit of detection than the method using Co{sub 3}O{sub 4} NPs and NiO NPs, as the single-component oxides of NiCo{sub 2}O{sub 4}. Our study may open up the possibility to make a great influence on the next generation of enzyme mimetics system. - Highlights: • NiCo{sub 2}O{sub 4} MS were found to possess the peroxidase and oxidase-like activity. • The peroxidase-like activity of NiCo{sub 2}O{sub 4} MS was stemmed from not only ·OH but also {sup 1}O{sub 2}. • The oxidase-like activity may stem from NiCo{sub 2}O{sub 4} MS′ oxidation rather than ·OH and {sup 1}O{sub 2}. • A colorimetric detection tool is designed for glucose determination in serum samples.

  3. Origin of low temperature deactivation of Ni5Ga3 nanoparticles as catalyst for methanol synthesis

    DEFF Research Database (Denmark)

    Gardini, Diego; Sharafutdinov, Irek; Damsgaard, Christian Danvad

    that the highest methanol yield is obtained with a Ni5Ga3 alloy exposed to a 25% CO2 – 75% H2 reaction mixture at 210 °C [2]. Under these experimental conditions, the catalyst is found to lose 35% of its activity after 20 hours of continuous testing at both 1 and 5 Bars. Although in situ XRD and EXAFS studies [3......In an effort to find alternative energy sources capable to compete with fossil fuels, methanol synthesis could represent a realistic solution to store “green” hydrogen produced from electrolysis or photo-induced water splitting. Recently, density functional theory (DFT) calculations [1] proposed Ni......-Ga alloys as active catalysts for methanol production from syngas mixtures and Ni-Ga nanoparticles supported on highly porous silica have been prepared using an incipient wetness impregnation technique from a solution of nickel and gallium nitrates [2]. Tests conducted in a fixed-bed reactor showed...

  4. Core/shell AgNi/PtAgNi nanoparticles as methanol-tolerant oxygen reduction electrocatalysts

    International Nuclear Information System (INIS)

    Wu, Dengfeng; Cheng, Daojian

    2015-01-01

    A core/shell AgNi/PtAgNi nanoparticle (NP) was synthesized via a new seed-mediated growth method in organic solvent medium. The as-synthesized AgNi/PtAgNiNP exhibits an AgNi core coated with PtAgNi shell, which was confirmed by transmission electron microscopy (TEM), ultraviolet–visible absorption spectroscopy and X-ray Photoelectron Spectroscopy (XPS). The AgNi/PtAgNiNPs/C catalyst possesses higher oxygen reduction reaction (ORR) activity and better durability compared with the commercial Pt/C catalyst. It is found that the ORR polarization curve of the AgNi/PtAgNiNPs/C catalyst shows an onset potential of 0.91 V vs. RHE, which is superior to the commercial Pt/C (0.88 V vs. RHE). In addition, the AgNi/PtAgNiNPs/C catalyst shows much better durability than the commercial Pt/C catalyst. More interestingly, the AgNi/PtAgNiNPs/C catalyst displays much higher methanol tolerance than the commercial Pt/C catalyst in 0.1 M KOH solution in the presence of 0.5 M methanol. Our results show that core/shell AgNi/PtAgNiNPs possess selective activity for ORR even in the presence of methanol, showing potential application as methanol-tolerant cathode catalysts in direct methanol fuel cells.

  5. Characteristics of monsoon low level jet (MLLJ)

    Indian Academy of Sciences (India)

    Temperature and wind data are used to describe variation in the strength of the Monsoon Low Level Jet (MLLJ) from an active phase of the monsoon to a break phase. Also estimated are the characteristics of turbulence above and below MLLJ.

  6. Update on the activities of the central interstate low-level radioactive waste compact commission

    International Nuclear Information System (INIS)

    Peery, R.J.

    1987-01-01

    Since its formation in 1983, the Central Interstate Low-Level Radioactive Waste Compact Commission has moved at a deliberate pace to meet the responsibilities placed on the states by federal law. In addition to the normal activities associated with an agency empowered to regulate a specific industry, the Commission has conducted a number of studies designed to help it meet its responsibilities. The Phase I Site Exclusionary Study identified those areas in each of the member states that failed to meet criteria set out in 10 CFR 61. The key elements of a Management Study are: an evaluation of the region's waste stream, development of the procedures the Commission will use to select a developer for the region's waste facility, an assessment of disposal alternatives, and the development of a plan to review the results of the management plan. The Commission is conducting a Phase II Site Exclusionary Study in which a closer analysis of each area will allow the Commission to determine if there are areas in each state that are capable of being sited. The Commission is also considering the draft Request for Proposals to Develop a Low-Level Radioactive Waste Facility within the Region

  7. The role of Ni in sulfided carbon-supported Ni-Mo hydrodesulfurization catalysts

    NARCIS (Netherlands)

    Bouwens, S.M.A.M.; Barthe-Zahir, N.; Beer, de V.H.J.; Prins, R.

    1991-01-01

    The thiophene hydrodesulfurization activities of Ni and Ni---Mo sulfide catalysts supported on activated carbon were measured at atmospheric pressure and the catalyst structures were studied by means of X-ray photoelectron spectroscopy, dynamic oxygen chemisorption, and chemical sulfur analysis. The

  8. A detailed study of Au-Ni bimetal synthesized by the phase separation mechanism for the cathode of low-temperature solid oxide fuel cells

    Science.gov (United States)

    Yang, Tao; Rodrigues de Almeida, Carlos Manuel; Ramasamy, Devaraj; Almeida Loureiro, Francisco José

    2014-12-01

    A facile co-reduction and annealing synthesis route of nanospheric particles of Au-Ni bimetal with adjustable composition was developed. In a typical synthesis, a direct co-reduction of HAuCl4.4H2O and NiCl2 in aqueous solution was performed with the assistance of reductive NaBH4 and an anionic surfactant sodium dodecyl sulfate (SDS) functioned as the structure-directing agent. Ultrasonic mixing was used at the same time to control the size of the particles. The morphology, microstructure and the state of the surface atoms were analyzed in detail. These nanospheres showed enhanced electrocatalytic activity towards oxygen reduction reaction than that of pure Au nanoparticles, demonstrated in the low temperature SOFC as cathode. The maximum power density generated is 810 mW cm-2 at 550 °C. This is a promising route of taking advantages the Phase Separation Mechanism to greatly reduce the use of noble metals in the ORR field without sacrificing the electrocatalytic activity.

  9. Electrochemical preparation and characteristics of Ni-Co-LaNi{sub 5} composite coatings as electrode materials for hydrogen evolution

    Energy Technology Data Exchange (ETDEWEB)

    Wu Gang; Li Ning; Dai Changsong; Zhou Derui

    2004-02-15

    Electrocatalytic activity for the hydrogen evolution reaction on Ni-Co-LaNi{sub 5} composite electrodes prepared by electrochemical codeposition technique was evaluated. The relationship between the current density for hydrogen evolution reaction and the amount of LaNi{sub 5} particles in Ni-Co baths is like the well-known 'volcano plot'. The Surface morphology and microstructure of Ni-Co-LaNi{sub 5} coatings were determined by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD). The kinetic parameters were determined from electrochemical steady-state Tafel polarization and electrochemical impedance spectroscopy technology in 1 M NaOH solution. The values obtained for the apparent energies of activation are 32.48, 46.29 and 57.03 kJ mol{sup -1} for the Ni-Co-LaNi{sub 5}, Ni-Co and Ni electrodes, respectively. The hydrogen evolution reaction on Ni-Co-LaNi{sub 5} proceeds via Volmer-Tafel reaction route with the mixed rate determining characteristics. The composite coating Ni-Co-LaNi{sub 5} is catalytically more active than Ni and Ni-Co electrodes due to the increase in its real surface areas and the decrease in the apparent free energy of activation caused by the electrocatalytic synergistic effect of the Ni-Co alloys and the hydrogen storage intermetallic particles on the electrode surface.

  10. Low-level waste certification plan

    International Nuclear Information System (INIS)

    Greenhalph, W.O.

    1995-01-01

    This plan describes the organization and methodology for the certification of solid low-level waste (LLW) and mixed-waste (MW) generated at any of the facilities or major work activities of the Engineered Process Application (EPA) organization. The primary LLW and MW waste generating facility operated by EPA is the 377 Building. This plan does not cover the handling of hazardous or non-regulated waste, though they are mentioned at times for completeness

  11. Low-level siting, Edgemont, South Dakota

    International Nuclear Information System (INIS)

    Andrews, L.J.

    1984-01-01

    The siting of a low-level radwaste disposal facility and characterization activities to date in Edgemont, South Dakota are discussed. By using past and present experience the author sets forth the major problem, the social and political considerations, community acceptance, media and public officials' attitudes, criteria for acceptance and significance of countywide vote in support of facility. Characterization activities, site selection planning and criteria, above-grade and below-grade technical evaluation, NRC interface, 10 CFR Part 61 related to technical work, as well as community acceptance and license application are covered. The paper deals with specific problems, solutions and ongoing activities

  12. Effect of organic complexants on the mobility of low-level-waste radionuclides in soils

    International Nuclear Information System (INIS)

    Swanson, J.L.

    1982-02-01

    The effect of certain organic complexants on the distribution of some radionuclides between solution and soil has been measured. The complexants and radionuclides examined are some of those most likely to be present in low-level waste disposal sites; Cs, Sr, Ni, Co, and Eu radionuclides, and EDTA, DTPA, oxalate, and citrate complexants. The effect of complexants was found to vary widely; in some systems there was no effect and in other systems there were large effects. In some cases slow rates of reaction have not allowed equilibrium measurements to be made

  13. Low level of objectively measured physical activity and cardiorespiratory fitness, and high prevalence of metabolic syndrome among Pakistani male immigrants in Oslo, Norway

    Directory of Open Access Journals (Sweden)

    Eivind Andersen

    2011-08-01

    Full Text Available Background: The level of physical fitness in south Asian immigrants living in Norway is largely unknown, but the level of physical activity seems to be low, possibly in part explaining their high prevalence of diabetes and cardiovascular diseases. However, previous studies have used self-reported measures of physical activity, and it might be questioned whether the previous data reflect the true physical activity level.Aim: To describe objectively measured physical activity level, cardiorespiratory fitness and diabetes risk in a group of Pakistani immigrant men living in Oslo, Norway.Methods: One hundred and fifty Pakistani immigrant men in the age group 25-60 years were included. Physical activity level was assessed with an accelerometer. Cardiorespiratory fitness was measured until exhaustion on a treadmill, and diabetes risk was evaluated with an oral glucose tolerance test.Results: Mean age was 37.3 years (SD=7.7. Total physical activity level was 308 counts/min (SD=131, and peak oxygen uptake was 34.2 ml·kg-1·min-1 (SD=5.6. Fifty percent of the participants had the metabolic syndrome, and 76% were obese. Physical activity level and cardiorespiratory fitness level were lower, and prevalence of the metabolic syndrome higher in a subgroup of taxi drivers as compared with those inother occupations (P<0.05.Conclusions: Physical activity and cardiorespiratory fitness levels are low and diabetes risk high among Pakistani immigrant men living in Oslo, especially in taxi drivers

  14. Hot-injection synthesis of Ni-ZnO hybrid nanocrystals with tunable magnetic properties and enhanced photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Deqian; Qiu, Yulong; Chen, Yuanzhi, E-mail: yuanzhi@xmu.edu.cn; Zhang, Qinfu; Liu, Xiang; Peng, Dong-Liang, E-mail: dlpeng@xmu.edu.cn [Xiamen University, Department of Materials Science and Engineering, Fujian Provincial Key Laboratory of Materials Genome, Collaborative Innovation Center of Chemistry for Energy Materials, College of Materials (China)

    2017-04-15

    Magnetic metal-semiconductor hybrid nanocrystals containing ferromagnetic Ni and semiconductor ZnO have been prepared via a hot-injection route. The Ni-ZnO hybrid nanocrystals have a flower-like morphology that consists of Ni inner cores and ZnO petal shells. In spite of their large lattice mismatch, ZnO nanocrystals can still grow on faceted Ni nanocrystals to form stable interfaces. The composition of Ni-ZnO hybrid nanocrystals is readily controlled, and the average size of Ni core is tunable from 25 to 50 nm. Room temperature ferromagnetic properties are observed in these hybrid nanocrystals, and tunable magnetic properties also can be achieved by varying the size of Ni core. The as-prepared Ni-ZnO hybrid nanocrystals exhibit enhanced photocatalytic performance under ultraviolet light illumination as compared to pure ZnO nanocrystals. Furthermore, the superior reusability of hybrid nanocrystals for photocatalytic application is achieved by virtue of their magnetic properties. The facile and efficient seed-mediate strategy is particularly attractive to construct hybrid magnetic-semiconducting heterostructures. The as-obtained Ni-ZnO hybrid nanocrystals offer great potential for various applications due to their combined magnetic and semiconducting properties and low-cost earth-abundant availability.

  15. Beta decay of 72Co and excited levels in 72Ni

    International Nuclear Information System (INIS)

    Grzywacz, R.; Rykaczewski, K.; Sawicka, M.; Pfuetzner, M.; Daugas, J.M.; Belier, G.; Sauvestre, J.E.; Meot, V.; Roig, O.; Giovinazzo, J.; Grawe, H.; Mayet, P.; Matea, I.; Georgiev, G.; Lewitowicz, M.; Olivieira, F. de; Stodel, C.; Saint-Laurent, M. G.; Stanoiu, M.; Verney, D.

    2003-01-01

    An experiment was performed at GANIL to observe isomeric- and beta-delayed gamma rays from very neutron-rich nuclei around 74Ni. Fragmentation products of the 86Kr beam at 58 AMeV were studied using new devices: the LISE 2000 spectrometer and detectors from the EXOGAM germanium array. The primary aim of the experiment was to find the 8+ microsecond isomer in 76Ni and to perform beta decay spectroscopy of Co nuclei. We have successfully measured the beta delayed gammas from the decay of 72Co to 72Ni. The energies for the lowest excited states in 72Ni are proposed, with the first 2+ state at 1096 keV. These findings suggest a solution of the problem of the disappearance of the 8+ isomer in 72Ni. We also measured beta decay of other neutron-rich Co isotopes including 70Co. First evidence was found for a new short lived isomer, most likely the Iπ=8+ state, in 76Ni

  16. p63 promotes cell survival through fatty acid synthase.

    Directory of Open Access Journals (Sweden)

    Venkata Sabbisetti

    2009-06-01

    Full Text Available There is increasing evidence that p63, and specifically DeltaNp63, plays a central role in both development and tumorigenesis by promoting epithelial cell survival. However, few studies have addressed the molecular mechanisms through which such important function is exerted. Fatty acid synthase (FASN, a key enzyme that synthesizes long-chain fatty acids and is involved in both embryogenesis and cancer, has been recently proposed as a direct target of p53 family members, including p63 and p73. Here we show that knockdown of either total or DeltaN-specific p63 isoforms in squamous cell carcinoma (SCC9 or immortalized prostate epithelial (iPrEC cells caused a decrease in cell viability by inducing apoptosis without affecting the cell cycle. p63 silencing significantly reduced both the expression and the activity of FASN. Importantly, stable overexpression of either FASN or myristoylated AKT (myr-AKT was able to partially rescue cells from cell death induced by p63 silencing. FASN induced AKT phosphorylation and a significant reduction in cell viability was observed when FASN-overexpressing SCC9 cells were treated with an AKT inhibitor after p63 knockdown, indicating that AKT plays a major role in FASN-mediated survival. Activated AKT did not cause any alteration in the FASN protein levels but induced its activity, suggesting that the rescue from apoptosis documented in the p63-silenced cells expressing myr-AKT cells may be partially mediated by FASN. Finally, we demonstrated that p63 and FASN expression are positively associated in clinical squamous cell carcinoma samples as well as in the developing prostate. Taken together, our findings demonstrate that FASN is a functionally relevant target of p63 and is required for mediating its pro-survival effects.

  17. Improved ethanol electrooxidation performance by shortening Pd–Ni active site distance in Pd–Ni–P nanocatalysts

    Science.gov (United States)

    Chen, Lin; Lu, Lilin; Zhu, Hengli; Chen, Yueguang; Huang, Yu; Li, Yadong; Wang, Leyu

    2017-01-01

    Incorporating oxophilic metals into noble metal-based catalysts represents an emerging strategy to improve the catalytic performance of electrocatalysts in fuel cells. However, effects of the distance between the noble metal and oxophilic metal active sites on the catalytic performance have rarely been investigated. Herein, we report on ultrasmall (∼5 nm) Pd–Ni–P ternary nanoparticles for ethanol electrooxidation. The activity is improved up to 4.95 A per mgPd, which is 6.88 times higher than commercial Pd/C (0.72 A per mgPd), by shortening the distance between Pd and Ni active sites, achieved through shape transformation from Pd/Ni–P heterodimers into Pd–Ni–P nanoparticles and tuning the Ni/Pd atomic ratio to 1:1. Density functional theory calculations reveal that the improved activity and stability stems from the promoted production of free OH radicals (on Ni active sites) which facilitate the oxidative removal of carbonaceous poison and combination with CH3CO radicals on adjacent Pd active sites. PMID:28071650

  18. Preparation and Characterization of Surface Photocatalytic Activity with NiO/TiO2 Nanocomposite Structure

    OpenAIRE

    Chen, Jian-Zhi; Chen, Tai-Hong; Lai, Li-Wen; Li, Pei-Yu; Liu, Hua-Wen; Hong, Yi-You; Liu, Day-Shan

    2015-01-01

    This study achieved a nanocomposite structure of nickel oxide (NiO)/titanium dioxide (TiO2) heterojunction on a TiO2 film surface. The photocatalytic activity of this structure evaluated by decomposing methylene blue (MB) solution was strongly correlated to the conductive behavior of the NiO film. A p-type NiO film of high concentration in contact with the native n-type TiO2 film, which resulted in a strong inner electrical field to effectively separate the photogenerated electron-hole pairs,...

  19. High levels of exosomes expressing CD63 and caveolin-1 in plasma of melanoma patients.

    Science.gov (United States)

    Logozzi, Mariantonia; De Milito, Angelo; Lugini, Luana; Borghi, Martina; Calabrò, Luana; Spada, Massimo; Perdicchio, Maurizio; Marino, Maria Lucia; Federici, Cristina; Iessi, Elisabetta; Brambilla, Daria; Venturi, Giulietta; Lozupone, Francesco; Santinami, Mario; Huber, Veronica; Maio, Michele; Rivoltini, Licia; Fais, Stefano

    2009-01-01

    Metastatic melanoma is an untreatable cancer lacking reliable and non-invasive markers of disease progression. Exosomes are small vesicles secreted by normal as well as tumor cells. Human tumor-derived exosomes are involved in malignant progression and we evaluated the presence of exosomes in plasma of melanoma patients as a potential tool for cancer screening and follow-up. We designed an in-house sandwich ELISA (Exotest) to capture and quantify exosomes in plasma based on expression of housekeeping proteins (CD63 and Rab-5b) and a tumor-associated marker (caveolin-1). Western blot and flow cytometry analysis of exosomes were used to confirm the Exotest-based findings. The Exotest allowed sensitive detection and quantification of exosomes purified from human tumor cell culture supernatants and plasma from SCID mice engrafted with human melanoma. Plasma levels of exosomes in melanoma-engrafted SCID mice correlated to tumor size. We evaluated the levels of plasma exosomes expressing CD63 and caveolin-1 in melanoma patients (n = 90) and healthy donors (n = 58). Consistently, plasma exosomes expressing CD63 (504+/-315) or caveolin-1 (619+/-310) were significantly increased in melanoma patients as compared to healthy donors (223+/-125 and 228+/-102, respectively). While the Exotest for CD63+ plasma exosomes had limited sensitivity (43%) the Exotest for detection of caveolin-1+ plasma exosomes showed a higher sensitivity (68%). Moreover, caveolin-1+ plasma exosomes were significantly increased with respect to CD63+ exosomes in the patients group. We describe a new non-invasive assay allowing detection and quantification of human exosomes in plasma of melanoma patients. Our results suggest that the Exotest for detection of plasma exosomes carrying tumor-associated antigens may represent a novel tool for clinical management of cancer patients.

  20. High levels of exosomes expressing CD63 and caveolin-1 in plasma of melanoma patients.

    Directory of Open Access Journals (Sweden)

    Mariantonia Logozzi

    Full Text Available BACKGROUND: Metastatic melanoma is an untreatable cancer lacking reliable and non-invasive markers of disease progression. Exosomes are small vesicles secreted by normal as well as tumor cells. Human tumor-derived exosomes are involved in malignant progression and we evaluated the presence of exosomes in plasma of melanoma patients as a potential tool for cancer screening and follow-up. METHODOLOGY/PRINCIPAL FINDINGS: We designed an in-house sandwich ELISA (Exotest to capture and quantify exosomes in plasma based on expression of housekeeping proteins (CD63 and Rab-5b and a tumor-associated marker (caveolin-1. Western blot and flow cytometry analysis of exosomes were used to confirm the Exotest-based findings. The Exotest allowed sensitive detection and quantification of exosomes purified from human tumor cell culture supernatants and plasma from SCID mice engrafted with human melanoma. Plasma levels of exosomes in melanoma-engrafted SCID mice correlated to tumor size. We evaluated the levels of plasma exosomes expressing CD63 and caveolin-1 in melanoma patients (n = 90 and healthy donors (n = 58. Consistently, plasma exosomes expressing CD63 (504+/-315 or caveolin-1 (619+/-310 were significantly increased in melanoma patients as compared to healthy donors (223+/-125 and 228+/-102, respectively. While the Exotest for CD63+ plasma exosomes had limited sensitivity (43% the Exotest for detection of caveolin-1+ plasma exosomes showed a higher sensitivity (68%. Moreover, caveolin-1+ plasma exosomes were significantly increased with respect to CD63+ exosomes in the patients group. CONCLUSIONS/SIGNIFICANCE: We describe a new non-invasive assay allowing detection and quantification of human exosomes in plasma of melanoma patients. Our results suggest that the Exotest for detection of plasma exosomes carrying tumor-associated antigens may represent a novel tool for clinical management of cancer patients.

  1. Low back pain in physically active young adults

    Directory of Open Access Journals (Sweden)

    Maja Bučar Pajek

    2012-03-01

    Full Text Available Background: Research of low back pain (LBP has been recently directed towards the younger age groups due to high predictive value for later life. The aim of the study was to assess the prevalence and risk factors for LBP in the Slovene population of young adults, which are yet unknown. Methods: In this cross sectional study firstgrade students at the Faculty of Sport (FS and the Faculty of Chemistry (FC, University of Ljubljana, in 2009 were included. The Slovene translation of Chronic Pain Grade questionnaire was implemented. In the FS subgroup the associations between questionnaire results and results of the entrance examination were analyzed and a follow-up questionnaire survey was done after the 1st semesterResults: The questionnaire was returned by 283 students. Average age was 19.9 (2.3 years. Lifelong and 6-month LBP prevalences were 87.3 % (83.1–90.9 % and 63 % (57.4–68.6 %, respectively. Average LBP intensity was 36.6 (16.9 (range 0–90 out of 100 points, average disability was 18 (18.7 (range 0–83 out of 100 points. Females had higher intensity and disability scores. Competitors had higher pain disability scores than students engaging in sports at recreational level. Gender and level of physical activity were significant independent predictors of intensity and disability scores at multivariate linear regression. LBP was not associated with entrance test results and there were no important changes in the follow- up after the 1st semester in the FS students. Conclusions: We found high LBP prevalence, which was of moderate intensity and caused minor disability. LBP was more severe in females and associated with the level of physical activity. Information about LBP and preventive workout programs should be incorporated into study programs.

  2. Fe-, Co-, and Ni-Loaded Porous Activated Carbon Balls as Lightweight Microwave Absorbents.

    Science.gov (United States)

    Li, Guomin; Wang, Liancheng; Li, Wanxi; Xu, Yao

    2015-11-16

    Porous activated carbon ball (PACB) composites impregnated with iron, cobalt, nickel and/or their oxides were synthesized through a wet chemistry method involving PACBs as the carrier to load Fe(3+), Co(2+), and Ni(2+) ions and a subsequent carbothermal reduction at different annealing temperatures. The results show that the pyrolysis products of nitrates and/or the products from the carbothermal reduction are embedded in the pores of the PACBs, with different distributions, resulting in different crystalline phases. The as-prepared PACB composites possessed high specific surface areas of 791.2-901.5 m(2)  g(-1) and low densities of 1.1-1.3 g cm(-3). Minimum reflection loss (RL) values of -50.1, -20.6, and -20.4 dB were achieved for Fe-PACB (annealed at 500 °C), Co-PACB (annealed at 800 °C), and Ni-PACB (annealed at 800 °C) composites, respectively. Moreover, the influence of the amount of the magnetic components in the PACB composites on the microwave-absorbing performances was investigated, further confirming that the dielectric loss was the primary contributor to microwave absorption. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Surface chemistry and catalytic activity of Ni/Al{sub 2}O{sub 3} irradiated with high-energy electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Jun, Jin [Department of Optometry and Optic Science, Dongshin University, 252 Daeho-Dong, Naju 520-714 (Korea, Republic of)], E-mail: jinjun@dsu.ac.kr; Dhayal, Marshal [Liquid Crystal and Self Assembled Monolayer Section, National Physical Laboratory, Dr. KS Krisnan Marg, New Delhi 120011 (India); Shin, Joong-Hyeok [Department of Environmental Engineering, Dongshin University, 252 Daeho-Dong, Naju 520-714 (Korea, Republic of); Han, Young Hwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Getoff, Nikola [Department of Nutrition, Section Radiation Biology, University of Vienna, Althanstr. 14, A-1090 Vienna (Austria)

    2008-05-30

    The radiation effects induced effects by electron beam (EB) treatment on the catalytic activity of Ni/{gamma}-Al{sub 2}O{sub 3} were studied for the carbon dioxide reforming of methane with different EB energy and absorbed radiation dose. Transmission electron microscope (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to determine the change in structure and surface states of Ni/{gamma}-Al{sub 2}O{sub 3} catalyst before and after the EB treatment. Higher energy EB treatment is useful for increasing the proportion of the active sites (such as Ni{sup 0} and NiAl{sub 2}O{sub 4}-phase) on the surface. The increase of Ni/Al-ratio indicates that the Ni dispersion on the surface increased with the EB-treatment, resulting in an increase of the active sites, which leads to improving the catalytic activity. XPS measurement also showed a decrease of the surface carbon with EB dose. The maximum 20% increase in the conversion of CO{sub 2}/CH{sub 4}-mixture into CO/H{sub 2} gas was observed for the catalyst treated with 2 MeV energy and 600 kGy dose of EB relative to untreated.

  4. 1989 state-by-state assessment of low-level radioactive wastes received at commercial disposal sites: National Low-Level Waste Management Program

    International Nuclear Information System (INIS)

    Fuchs, R.L.; Culbertson-Arendts, K.

    1990-12-01

    The National Low-Level Waste Management Program has published eleven annual state-by-state assessment reports. These reports provide both national and state-specific disposal data on low-level radioactive wastes. Data in this report are divided into generator category, waste class, volume, and activity. Included in this report are tables showing a distribution of wastes by state for 1989 and a comparison of waste volumes by state for 1985 through 1989; also included is a list of all commercial nuclear power reactors in the United States as of December 31, 1989. In this year's report, a distinction has been made between low-level radioactive waste shipped directly for disposal by generators and that handled by an intermediary. 7 refs., 4 tabs

  5. NiO/nanoporous graphene composites with excellent supercapacitive performance produced by atomic layer deposition

    International Nuclear Information System (INIS)

    Chen, Caiying; Chen, Chaoqiu; Duan, Feifei; Zhao, Shichao; Qin, Yong; Huang, Peipei; Li, Ping; Fan, Jinchuan; Song, Weiguo

    2014-01-01

    Nickel oxide (NiO) is a promising electrode material for supercapacitors because of its low cost and high theoretical specific capacitance of 2573 F g −1 . However, the low electronic conductivity and poor cycling stability of NiO limit its practical applications. To overcome these limitations, an efficient atomic layer deposition (ALD) method is demonstrated here for the fabrication of NiO/nanoporous graphene (NG) composites as electrode materials for supercapacitors. ALD allows uniform deposition of NiO nanoparticles with controlled sizes on the surface of NG, thus offering a novel route to design NiO/NG composites for supercapacitor applications with high surface areas and greatly improved electrical conductivity and cycle stability. Electrochemical measurements reveal that the NiO/NG composites obtained by ALD exhibited excellent specific capacitance of up to ∼1005.8 F g −1 per mass of the composite electrode (the specific capacitance value is up to ∼1897.1 F g −1 based on the active mass of NiO), and stable performance after 1500 cycles. Furthermore, electrochemical performance of the NiO/NG composites is found to strongly depend on the size of NiO nanoparticles. (paper)

  6. [Factors associated with low levels of aerobic fitness among adolescents].

    Science.gov (United States)

    Gonçalves, Eliane Cristina de Andrade; Silva, Diego Augusto Santos

    2016-06-01

    To evaluate the prevalence of low aerobic fitness levels and to analyze the association with sociodemographic factors, lifestyle and excess body fatness among adolescents of southern Brazil. The study included 879 adolescents aged 14 to 19 years the city of São José/SC, Brazil. The aerobic fitness was assessed by Canadian modified test of aerobic fitness. Sociodemographic variables (skin color, age, sex, study turn, economic level), sexual maturation and lifestyle (eating habits, screen time, physical activity, consumption of alcohol and tobacco) were assessed by a self-administered questionnaire. Excess body fatness was evaluated by sum of skinfolds triceps and subscapular. We used logistic regression to estimate odds ratios and 95% confidence intervals. Prevalence of low aerobic fitness level was 87.5%. The girls who spent two hours or more in front screen, consumed less than one glass of milk by day, did not smoke and had an excess of body fatness had a higher chance of having lower levels of aerobic fitness. White boys with low physical activity had had a higher chance of having lower levels of aerobic fitness. Eight out of ten adolescents were with low fitness levels aerobic. Modifiable lifestyle factors were associated with low levels of aerobic fitness. Interventions that emphasize behavior change are needed. Copyright © 2015 Sociedade de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

  7. Chemical diffusion of Cr, Ni and Si in welded joints. II

    International Nuclear Information System (INIS)

    Kucera, J.; Ciha, K.

    1987-01-01

    The results are given of a study in chemical diffusion in welded joints P2/A and P3/A. P2 stands for the steel (Fe-17.48 Cr-8.15 Ni-0.14 Si), P3 for (Fe-18.52 Cr-8.20 Ni-1.78 Si) and A for the Fe-Arema. Triadic sandwiche-like samples were diffusion heated at temperatures from 920 to 1170 degC. The concentration distributions N(x,t) of the given elements were measured with microprobe JXA-3A. The evaluation of the experimental data was carried out either by Grube's method, or in some cases by the spline-polynomial method. The evaluated diffusivities D-bar satisfy the Arrhenius relation and yield the standard diffusion characteristics D 0 and H. The diffusivities D-bar of Cr, Ni and Si in P1/A, in P2/A and P3/A welded joints vary with Si content in P1, P2 and P3 alloys, similar to the Cr-51 and Ni-63 self-diffusivities in Fe-18 Cr-12 Ni-X Si steels, and tend to increase with increasing Si content. The values D-bar measured in the vicinity of grain boundaries are higher than the bulk diffusion coefficients. The most rapid diffusant is Si and the slowest one Ni. Thus, the relations D-bar Si :D-bar Cr :D-bar Ni ≅ 6:3:1 (P3/A) and D-bar Si :D-bar Cr :D-bar Ni ≅ 1.7:1.4:1 (P3/A) are valid at 1050 degC. Comparing the results with those published if can be noted that the Cr-51 and Ni-63 self-diffusion in Fe-18 Cr-12 Ni-X Si steels is faster than chemical diffusion of these elements in the said steel welded joints P2/A and P3/A; X varies from 0.14 to 1.98. (author). 7 tabs., 7 figs., 20 refs

  8. p63 expression defines a lethal subset of muscle-invasive bladder cancers.

    Directory of Open Access Journals (Sweden)

    Woonyoung Choi

    Full Text Available p63 is a member of the p53 family that has been implicated in maintenance of epithelial stem cell compartments. Previous studies demonstrated that p63 is downregulated in muscle-invasive bladder cancers, but the relationship between p63 expression and survival is not clear.We used real-time PCR to characterize p63 expression and several genes implicated in epithelial-to-mesenchymal transition (EMT in human bladder cancer cell lines (n = 15 and primary tumors (n = 101. We correlated tumor marker expression with stage, disease-specific (DSS, and overall survival (OS. Expression of E-cadherin and p63 correlated directly with one another and inversely with expression of the mesenchymal markers Zeb-1, Zeb-2, and vimentin. Non-muscle-invasive (Ta and T1 bladder cancers uniformly expressed high levels of E-cadherin and p63 and low levels of the mesenchymal markers. Interestingly, a subset of muscle-invasive (T2-T4 tumors maintained high levels of E-cadherin and p63 expression. As expected, there was a strongly significant correlation between EMT marker expression and muscle invasion (p<0.0001. However, OS was shorter in patients with muscle-invasive tumors that retained p63 (p = 0.007.Our data confirm that molecular markers of EMT are elevated in muscle-invasive bladder cancers, but interestingly, retention of the "epithelial" marker p63 in muscle-invasive tumors is associated with a worse outcome.

  9. In situ visualization of Ni-Nb bulk metallic glasses phase transition

    OpenAIRE

    Oreshkin, A. I.; Mantsevich, V. N.; Savinov, S. V.; Oreshkin, S. I.; Panov, V. I.; Yavari, A. R.; Miracle, D. B.; Louzguine-Luzgin, D. V.

    2013-01-01

    We report the results of the Ni-based bulk metallic glass structural evolution and crystallization behavior in situ investigation. The X-ray diffraction (XRD), transmission electron microscopy (TEM), nano-beam diffraction (NBD), differential scanning calorimetry (DSC), radial distribution function (RDF) and scanning probe microscopy/spectroscopy (STM/STS) techniques were applied to analyze the structure and electronic properties of Ni63.5Nb36.5 glasses before and after crystallization. It was...

  10. Low-level effects

    International Nuclear Information System (INIS)

    Devine, R.T.; Chaput, R.L.

    1987-01-01

    Risk assignments can be made to given practices involving exposure to radiation, because sufficient data are available for the effects of high-dose, low-LET radiation and because sufficient exists in the methods of extrapolation to low doses and low dose rates. The confidence in the extrapolations is based on the fact that the risk is not expected to be overestimated, using the assumptions made (as opposed to the possibility that the extrapolations represent an accurate estimate of the risk). These risk estimates have been applied to the selection of permissible exposure levels, to show that various amounts of radiation involve no greater risk to the worker than the risk expected in another industry that is generally considered safe. The setting of standards for protection from exposure to low levels of ionizing radiation is made by expert committees at the national and international levels who weigh social factors as well as scientific factors. Data on low-level effects may be applied when assigning a ''probability of causation'' to a certain exposure of radiation. This has become a prominent method for arriving at an equitable award for damages caused by such exposure. The generation of these tables requires as many (if not more) social and political considerations as does the setting up of protection criteria. It is impossible to extract a purely scientific conclusion solely from the protection standards and other legal decisions. Sufficient information exists on low-LET radiation that safety standards for exposure can be rationally (if not scientifically) agreed upon

  11. PROMETHEE: An Alpha Low Level Waste Assay System Using Passive and Active Neutron Measurement Methods

    International Nuclear Information System (INIS)

    Passard, Christian; Mariani, Alain; Jallu, Fanny; Romeyer-Dherbey, Jacques; Recroix, Herve; Rodriguez, Michel; Loridon, Joel; Denis, Caroline; Toubon, Herve

    2002-01-01

    The development of a passive-active neutron assay system for alpha low level waste characterization at the French Atomic Energy Commission is discussed. Less than 50 Bq[α] (about 50 μg Pu) per gram of crude waste must be measured in 118-l 'European' drums in order to reach the requirements for incinerating wastes. Detection limits of about 0.12 mg of effective 239 Pu in total active neutron counting, and 0.08 mg of effective 239 Pu coincident active neutron counting, may currently be detected (empty cavity, measurement time of 15 min, neutron generator emission of 1.6 x 10 8 s -1 [4π]). The most limiting parameters in terms of performances are the matrix of the drum - its composition (H, Cl...), its density, and its heterogeneity degree - and the localization and self-shielding properties of the contaminant

  12. Structure-activity relations for Ni-containing zeolites during NO reduction. II. Role of the chemical state of Ni

    NARCIS (Netherlands)

    Mosqueda Jimenez, B.I.; Jentys, A.; Seshan, Kulathuiyer; Lercher, J.A.

    2003-01-01

    The influence of the metal in Ni-containing zeolites used as catalysts for the reduction of NO with propane and propene was studied. In the fresh catalysts, Ni is located in ion exchange positions for Ni/MOR, Ni/ZSM-5, and Ni/MCM-22. The formation of carbonaceous deposits, the removal of Al from

  13. A low knee voltage and high breakdown voltage of 4H-SiC TSBS employing poly-Si/Ni Schottky scheme

    Science.gov (United States)

    Kim, Dong Young; Seok, Ogyun; Park, Himchan; Bahng, Wook; Kim, Hyoung Woo; Park, Ki Cheol

    2018-02-01

    We report a low knee voltage and high breakdown voltage 4H-SiC TSBS employing poly-Si/Ni dual Schottky contacts. A knee voltage was significantly improved from 0.75 to 0.48 V by utilizing an alternative low work-function material of poly-Si as an anode electrode. Also, reverse breakdown voltage was successfully improved from 901 to 1154 V due to a shrunk low-work-function Schottky region by a proposed self-align etching process between poly-Si and SiC. SiC TSBS with poly-Si/Ni dual Schottky scheme is a suitable structure for high-efficiency rectification and high-voltage blocking operation.

  14. g-factor of the 9/2+ isomeric state in 65Ni from transfer reaction

    International Nuclear Information System (INIS)

    Georgiev, G.; Matea, I.; Balabanski, D.L.; Daugas, J.M.; Meot, V.; Morel, P.; Oliveira Santos, F. de; Lewitowicz, M.; Franchoo, S.; Ibrahim, F.; Le Blanc, F.; Sorlin, O.; Stanoiu, M.; Verney, D.; Lo Bianco, G.; Saltarelli, A.; Lukyanov, S.; Penionzhkevich, Yu.E.; Neyens, G.; Vermeulen, N.; Yordanov, D.; Tarisien, M.

    2006-01-01

    We report a measurement of the g-factor of the I π =9/2 + , t 1/2 =22 ns isomer in 65 Ni. The state of interest was populated and spin-oriented using a single-neutron transfer on an enriched 64 Ni target. The value, which was obtained, g(9/2 + , 65m Ni)=-0.296(3) is well in agreement with the g-factors of the other 9/2 + states in the region and with large-basis shell model calculations. The known g-factor of the 9/2 + isomer in 63 Ni was used in order to verify the strength of the hyperfine field of Ni(Ni) at room temperature. (orig.)

  15. Low-level radioactive waste disposal: radiation protection laws

    International Nuclear Information System (INIS)

    Chapuis, A.M.; Guetat, P.; Garbay, H.

    1991-01-01

    The politics of radioactive waste management is a part of waste management and activity levels are one of the components of potential waste pollutions in order to assume man and environment safety. French regulations about personnel and public' radiation protection defines clearly the conditions of radioactive waste processing, storage, transport and disposal. But below some activity levels definite by radiation protection laws, any administrative procedures or processes can be applied for lack of legal regulations. So regulations context is not actually ready to allow a rational low-level radioactive waste management. 15 refs.; 4 tabs.; 3 figs

  16. Nanofoaming to Boost the Electrochemical Performance of Ni@Ni(OH)2 Nanowires for Ultrahigh Volumetric Supercapacitors.

    Science.gov (United States)

    Xu, Shusheng; Li, Xiaolin; Yang, Zhi; Wang, Tao; Jiang, Wenkai; Yang, Chao; Wang, Shuai; Hu, Nantao; Wei, Hao; Zhang, Yafei

    2016-10-10

    Three-dimensional free-standing film electrodes have aroused great interest for energy storage devices. However, small volumetric capacity and low operating voltage limit their practical application for large energy storage applications. Herein, a facile and novel nanofoaming process was demonstrated to boost the volumetric electrochemical capacitance of the devices via activation of Ni nanowires to form ultrathin nanosheets and porous nanostructures. The as-designed free-standing Ni@Ni(OH) 2 film electrodes display a significantly enhanced volumetric capacity (462 C/cm 3 at 0.5 A/cm 3 ) and excellent cycle stability. Moreover, the as-developed hybrid supercapacitor employed Ni@Ni(OH) 2 film as positive electrode and graphene-carbon nanotube film as negative electrode exhibits a high volumetric capacitance of 95 F/cm 3 (at 0.25 A/cm 3 ) and excellent cycle performance (only 14% capacitance reduction for 4500 cycles). Furthermore, the volumetric energy density can reach 33.9 mWh/cm 3 , which is much higher than that of most thin film lithium batteries (1-10 mWh/cm 3 ). This work gives an insight for designing high-volume three-dimensional electrodes and paves a new way to construct binder-free film electrode for high-performance hybrid supercapacitor applications.

  17. Management of low-level radioactive wastes around the world

    International Nuclear Information System (INIS)

    Lakey, L.T.; Harmon, K.M.; Colombo, P.

    1985-04-01

    This paper reviews the status of various practices used throughout the world for managing low-level radioactive wastes. Most of the information in this review was obtained through the DOE-sponsored International Program Support Office (IPSO) activities at Pacific Northwest Laboratory (PNL) at Richland, Washington. The objective of IPSO is to collect, evaluate, and disseminate information on international waste management and nuclear fuel cycle activities. The center's sources of information vary widely and include the proceedings of international symposia, papers presented at technical society meetings, published topical reports, foreign trip reports, and the news media. Periodically, the information is published in topical reports. Much of the information contained in this report was presented at the Fifth Annual Participants' Information Meeting sponsored by DOE's Low-Level Waste Management Program Office at Denver, Colorado, in September of 1983. Subsequent to that presentation, the information has been updated, particularly with information provided by Dr. P. Colombo of Brookhaven National Laboratory who corresponded with low-level waste management specialists in many countries. The practices reviewed in this paper generally represent actual operations. However, major R and D activities, along with future plans, are also discussed. 98 refs., 6 tabls

  18. Health effects of low level radiation

    International Nuclear Information System (INIS)

    Hattori, Sadao

    1998-01-01

    In 1982, Prof. Thomas Don Luckey of Missouri Univ. asserted 'Radiation Hormesis' on the Journal of Health Physics and he published two books. CRIEPI initiated the research program on Radiation Hormesis following his assertion to confirm 'is it true or not?' After nearly ten year research activities on data surveys and animal tests with many Universities, we are realizing scientific truth of bio-positive effects by low level radiation exposures. The interesting bio-positive effects we found could be categorized in following five groups. 1) Rejuvenation of cells such as increase of SOD and cell membrane permeability, 2) Moderation of psychological stress through response of key enzymes, 3) Suppression and therapy of adult-diseases such as diabetes and hypertension, 4) Suppression of cancer through enhancement of immune systems such as lymphocytes, 5) Suppression of cancer and ratio-adaptive response by activation of DNA repair and apoptosis. In the responses of many specialists to our initiation of radiation hormesis research program following T.D. Luckey's claim about low level radiation, I have to pick up for the first, the great success of Prof. Sakamoto. Prof. Sakamoto had been already applying whole body low dose irradiation for ten years before our radiation hormesis research started on the therapy to suppress the cancer reappearing after treatment. He reported about his successful trial to real patients and showed an enhancement of immune system. (author)

  19. Health effects of low level radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hattori, Sadao [Central Research Inst. of Electric Power Industry, Tokyo (Japan)

    1998-12-31

    In 1982, Prof. Thomas Don Luckey of Missouri Univ. asserted `Radiation Hormesis` on the Journal of Health Physics and he published two books. CRIEPI initiated the research program on Radiation Hormesis following his assertion to confirm `is it true or not?` After nearly ten year research activities on data surveys and animal tests with many Universities, we are realizing scientific truth of bio-positive effects by low level radiation exposures. The interesting bio-positive effects we found could be categorized in following five groups. 1) Rejuvenation of cells such as increase of SOD and cell membrane permeability, 2) Moderation of psychological stress through response of key enzymes, 3) Suppression and therapy of adult-diseases such as diabetes and hypertension, 4) Suppression of cancer through enhancement of immune systems such as lymphocytes, 5) Suppression of cancer and ratio-adaptive response by activation of DNA repair and apoptosis. In the responses of many specialists to our initiation of radiation hormesis research program following T.D. Luckey`s claim about low level radiation, I have to pick up for the first, the great success of Prof. Sakamoto. Prof. Sakamoto had been already applying whole body low dose irradiation for ten years before our radiation hormesis research started on the therapy to suppress the cancer reappearing after treatment. He reported about his successful trial to real patients and showed an enhancement of immune system. (author)

  20. Carbon Supported Engineering NiCo2O4 Hybrid Nanofibers with Enhanced Electrocatalytic Activity for Oxygen Reduction Reaction

    Directory of Open Access Journals (Sweden)

    Diab Hassan

    2016-09-01

    Full Text Available The design of cheap and efficient oxygen reduction reaction (ORR electrocatalysts is of a significant importance in sustainable and renewable energy technologies. Therefore, ORR catalysts with superb electrocatalytic activity and durability are becoming a necessity but still remain challenging. Herein, we report C/NiCo2O4 nanocomposite fibers fabricated by a straightforward electrospinning technique followed by a simple sintering process as a promising ORR electrocatalyst in alkaline condition. The mixed-valence oxide can offer numerous accessible active sites. In addition, the as-obtained C/NiCo2O4 hybrid reveals significantly remarkable electrocatalytic performance with a highly positive onset potential of 0.65 V, which is only 50 mV lower than that of commercially available Pt/C catalysts. The analyses indicate that C/NiCo2O4 catalyst can catalyze O2-molecules via direct four electron pathway in a similar behavior as commercial Pt/C catalysts dose. Compared to single NiCo2O4 and carbon free NiCo2O4, the C/NiCo2O4 hybrid displays higher ORR current and more positive half-wave potential. The incorporated carbon matrices are beneficial for fast electron transfer and can significantly impose an outstanding contribution to the electrocatalytic activity. Results indicate that the synthetic strategy hold a potential as efficient route to fabricate highly active nanostructures for practical use in energy technologies.

  1. Electrochemical vs X-ray Spectroscopic Measurements of NiFe(CN)6 Crystals

    Science.gov (United States)

    Peecher, Benjamin; Hampton, Jennifer

    Pseudocapacitive materials like hexacyanoferrate have greater energy storage capabilities than standard capacitors while maintaining an ability to charge and discharge quickly. We modify the surface of an electrodeposited Ni thin film with a layer of hexacyanoferrate. Charging and discharging these modified films using cyclic voltammetry (CV) allows us to measure the electrochemically active Fe in the film. To determine how closely this resembles the full amount of Fe in the film, we measure the films' composition using particle-induced x-ray emission (PIXE). We also vary the amount of Ni deposited, both to compare the electrolysis value of charge deposited to the PIXE measurement of Ni in the film, and also to measure how varying the thickness of the Ni surface affects the presence of Fe in the film. Comparisons of the CV and PIXE measurements show agreement in Ni levels but disagreement in Fe levels. PIXE measurements of Fe in the film have positive correlation with Ni in the film. This correlation between PIXE measurements of Ni and Fe suggests that PIXE provides a reliable measure of Fe in the film. This implies that a variable proportion of total Fe in a given film is electrochemically active. This research was made possible by the Hope College Department of Physics Frissel Research Fund and the National Science Foundation under Grants RUI-DMR-1104725, MRI-CHE-0959282, and MRI/RUI-PHY-0319523.

  2. Seventh annual DOE LLWMP participants' information meeting. DOE Low-Level Waste Management Program. Abstracts

    International Nuclear Information System (INIS)

    1985-08-01

    The following sessions were held: International Low-Level Waste Management Activities; Low-Level Waste Disposal; Characteristics and Treatment of Low-Level Waste; Environmental Monitoring and Performance; Greater Confinement and Alternative Disposal Methods; Low-Level Waste Management; Corrective Measures; Performance Prediction and Assessment; and Siting New Defense and Commercial Low-Level Waste Disposal Facilities

  3. Improvement of thermoelectric properties for half-Heusler TiNiSn by interstitial Ni defects

    International Nuclear Information System (INIS)

    Hazama, Hirofumi; Matsubara, Masato; Asahi, Ryoji; Takeuchi, Tsunehiro

    2011-01-01

    We have synthesized off-stoichiometric Ti-Ni-Sn half-Heusler thermoelectrics in order to investigate the relation between randomly distributed defects and thermoelectric properties. A small change in the composition of Ti-Ni-Sn causes a remarkable change in the thermal conductivity. An excess content of Ni realizes a low thermal conductivity of 2.93 W/mK at room temperature while keeping a high power factor. The low thermal conductivity originates in the defects generated by an excess content of Ni. To investigate the detailed defect structure, we have performed first-principles calculations and compared with x ray photoemission spectroscopy measurement. Based on these analyses, we conclude that the excess Ni atoms randomly occupy the vacant sites in the half-Heusler structure, which play as phonon scattering centers, resulting in significant improvement of the figure of merit without any substitutions of expensive heavy elements, such as Zr and Hf.

  4. Low-level siting, Edgemont, South Dakota

    International Nuclear Information System (INIS)

    Andrews, L.J.

    1984-01-01

    The siting of a low-level radwaste disposal facility and characterization activities to date, at Edgemont, South Dakota are given. Using past and present experience setting forth the major problem as viewed by the author, the social and political considerations, community acceptance, media and public officials' attitudes, criteria for acceptance and significance of countywide vote in support of facility are presented. Characterization activities, site selection planning and criteria, above-grade and below-grade technical evaluation, NRC interface, 10 CFR Part 61 related to technical work, as well as community acceptance and license application are included. The paper deals with specific problems, solutions and ongoing activities

  5. Preparation of Au/Y2O3 and Au/NiO catalysts by co-precipitation and their oxidation activities

    International Nuclear Information System (INIS)

    Sreethawong, Thammanoon; Sitthiwechvijit, Norsit; Rattanachatchai, Apiwat; Ouraipryvan, Piya; Schwank, Johannes W.; Chavadej, Sumaeth

    2011-01-01

    Research highlights: → The catalytic activity of Au catalysts supported on Y 2 O 3 and NiO prepared by co-precipitation was investigated for CO and methanol oxidation. → The phase transformation of yttrium support greatly affected the CO oxidation activity. → The Au/Y 2 O 3 exhibited the same activity as Au/NiO for the methanol oxidation while the Au/NiO gave higher activity for CO oxidation. - Abstract: The objective of this work was to investigate the catalytic activity of gold catalysts supported on two metal oxides, yttrium oxide and nickel oxide, prepared by co-precipitation for CO and methanol oxidation reactions. The TGA and XRD results confirmed that yttrium hydroxide (Y(OH) 3 ) was formed at calcination temperature below 300 deg. C. When it was calcined at 400 deg. C, the Y(OH) 3 was transformed to yttrium oxide hydroxide (YOOH). Finally, when calcination temperature was raised to 600 deg. C, the YOOH was completely transformed to yttrium oxide (Y 2 O 3 ). Interestingly, the gold loaded on YOOH calcined at 400 deg. C and gold loaded on Y 2 O 3 calcined at 500 deg. C comparatively showed the highest catalytic activity for complete CO oxidation at a reaction temperature of 300 deg. C. The 0.12% Au/Y 2 O 3 catalyst calcined at 500 deg. C was employed for both CO and methanol oxidation studies. For complete CO oxidation, the reaction temperatures of Au/Y 2 O 3 and Au/NiO catalysts were 325 deg. C and 250 deg. C, respectively. The light-off temperatures of Au/Y 2 O 3 and Au/NiO catalysts for methanol oxidation were 210 deg. C and 205 deg. C, respectively. Conclusively, the Au/Y 2 O 3 clearly exhibited the same activity as that of Au/NiO for methanol oxidation while the Au/NiO gave higher activity for CO oxidation.

  6. 10 CFR 63.9 - Employee protection.

    Science.gov (United States)

    2010-01-01

    ... because the employee has engaged in protected activities. An employee's engagement in protected activities... 10 Energy 2 2010-01-01 2010-01-01 false Employee protection. 63.9 Section 63.9 Energy NUCLEAR... MOUNTAIN, NEVADA General Provisions § 63.9 Employee protection. (a) Discrimination by a Commission licensee...

  7. Greater-than-Class-C low-level radioactive waste management concepts

    International Nuclear Information System (INIS)

    Knecht, M.A.

    1988-01-01

    In 1986, Public Law 99-240, the Low-Level Radioactive Waste Policy Amendments Act of 1985 assigned to the Federal Government responsibility for the disposal of commercial greater-than-Class-C (GTCC) low-level radioactive waste (LLW). In 1987, DOE committed to Congress to accept GTCC LLW and provide storage and other waste management as necessary until disposal capacity is available. Current estimates are that about 6,000 m 3 of unpackaged GTCC LLW will be generated to the year 2020. Generators estimate that 100 m 3 of raw GTCC LLW might exceed planned storage capacity to the year 2020. This paper reports the activities of the National Low-Level Waste Program to manage GTCC low-level radioactive waste

  8. Geometric structures of thin film: Pt on Pd(110) and NiO on Ni(100)

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Oden L. [Iowa State Univ., Ames, IA (United States)

    1993-07-01

    This thesis is divided into 3 papers: dynamical low-energy electron- diffraction investigation of lateral displacements in topmost layer of Pd(110); determination of (1x1) and (1x2) structures of Pt thin films on Pd(110) by dynamical low-energy electron-diffraction analysis; and structural determination of a NiO(111) film on Ni(100) by dynamical low-energy electron-diffraction analysis.

  9. Effects of short-range order on electronic properties of Zr-Ni glasses as seen from low-temperature specific heat

    International Nuclear Information System (INIS)

    Kroeger, D.M.; Koch, C.C.; Scarbrough, J.O.; McKamey, C.G.

    1984-01-01

    Measurements of the low-temperature specific heat C/sub p/ of liquid-quenched Zr-Ni glasses for a large number of compositions in the range from 55 to 74 at. % Zr revealed an unusual composition dependence of the density of states at the Fermi level, N(E/sub F/). Furthermore, for some compositions the variation of C/sub p/ near the superconducting transition temperature T/sub c/ indicated the presence of two superconducting phases, i.e., two superconducting transitions were detected. Comparison of the individual T/sub c/'s in phase-separated samples to the composition dependence of T/sub c/ for all of the samples suggests that amorphous phases with compositions near 60 and 66.7 at. % Zr occur. We discuss these results in terms of an ''association model'' for liquid alloys (due to Sommer), in which associations of unlike atoms with definite stoichiometries are assumed to exist in equilibrium with unassociated atoms. We conclude that in the composition range studied, associate clusters with the compositions Zr 3 Ni 2 and Zr 2 Ni occur. In only a few cases are the clusters sufficiently large, compared with the superconducting coherence length, for separate superconducting transitions to be observed. The variation of N(E/sub F/) with composition is discussed, as well as the effects of this chemical short-range ordering on the crystallization behavior and glass-forming tendency

  10. Crystal field and low energy excitations measured by high resolution RIXS at the L edge of Cu, Ni and Mn

    DEFF Research Database (Denmark)

    Ghiringhelli, G.; Piazzalunga, A.; Wang, X.

    2009-01-01

    of the 3d transition metals with unprecedented energy resolution, of the order of 100 meV for Mn, Ni and Cu. We present here some preliminary spectra on CuO, malachite, NiO, , MnO and . The dd excitations are very well resolved allowing accurate experimental evaluation of 3d state energy splitting. The low...

  11. Bimetallic Ag–Ni/C particles as cathode catalyst in AFCs (alkaline fuel cells)

    International Nuclear Information System (INIS)

    Song, Xingjuan; Zhang, Dongming

    2014-01-01

    AFCs (alkaline fuel cells) is one of the promising fuel cells, due to their low working temperature and less corrosive environment. However, decreasing the catalyst cost and improving its performance are still the challenges in its application. Transition metal as the catalyst for AFCs not only can reduce its cost, but also has great electro-catalytic efficiency. In this paper, Carbon supported Ag–Ni bimetallic catalysts with differential Ag/Ni atomic ratios were prepared by chemically reducing silver and nickel salts. Ag 3 Ni/C shows the relatively higher ORR (oxygen reduction reaction) activity among the differential Ag/Ni bimetallic particles. In order to improve the activity and stability, the catalysts were heat-treated at the temperature of 500 °C. The results indicate that the limiting current density has been improved greatly for Ag 3 Ni/C-500 °C, which is as high as 2.5× that of Ag/C. The microstructure investigation show that the non-equilibrium state of Ag–Ni alloy by heat treatment is confirmed by HRTEM (high-resolution transmission electron microscopy) images, and Ag(111) surfaces are decreased in XRD pattern, which results in the ORR activity improved and overpotential decreased. Heat treatment also has contributed to Ag–Ni/C electrochemistry stability in some degree. - Highlights: • Ag–Ni/C is applied as cathode catalyst for AFCs (alkaline fuel cells). • Ag 3 Ni/C-500 °C shows the best performance. • Non-equilibrium state of Ag–Ni alloy by heat treatment is observed. • The decreased Ag(111) surfaces are favor to improve the catalyst activity

  12. Influence of Leisure Competence and Level of Leisure Activity on Life Satisfaction in Low-Income Older Adults in Rural South Korea.

    Science.gov (United States)

    Choi, Jihea; Choi, Jung A

    2017-03-01

    The purpose of the current study was to investigate the relationships among leisure competence, level of leisure activity, and life satisfaction in low-income older adults in rural South Korea. A sample of 137 older adults answered the study questionnaire, and significant differences in leisure competence were noted depending on age, religion, and perceived health status as well as level of leisure activity based on perceived health status and type of leisure activities. There were also notable differences in life satisfaction regarding religion and perceived health status, and a correlation among leisure competence, level of leisure activity, and life satisfaction; the influencing power of leisure competence and level of leisure activity on life satisfaction was 47%. The findings suggest that enhancement of older adults' leisure competence may increase participation in leisure activities. [Res Gerontol Nurs. 2017; 10(2):67-75.]. Copyright 2017, SLACK Incorporated.

  13. Strength and low temperature toughness of Fe-13%Ni-Mo alloys

    International Nuclear Information System (INIS)

    Ishikawa, Keisuke; Maruyama, Norio; Tsuya, Kazuo

    1978-01-01

    Mechanical tests were made on newly developed Fe-13%Ni-Mo alloys for eryogenic service. The effects of the additional elements were investigated from the viewpoint of the strength and the low temperature toughness. The alloys added by Al, Ti or V have the better balance of these properties. They did not show low temperature brittleness induced by cleavage fracture in Charpy impact test at 77 K. The microfractography showed the utterly dimple rupture patterns on the broken surface of all specimens. It would be supposed that the cleavage fracture stress is considerably higher than the flow stress. These alloys are superior to some commercial structural materials for low temperature use in the balance between the strength at 300 K and the toughness at 77 K. Additionally, it is noted that these experimental alloys have a good advantage in getting high strength and high toughness by the rather simple heat treatment. (auth.)

  14. Low back pain and low level flying

    NARCIS (Netherlands)

    J.C.F.M. Aghina

    1989-01-01

    textabstractLow level flying is a very good tactical possibility to carry out a mission unseen by a hostile radarsystem. Nowadays, Western Europe in general and the Federal Republic of Germany in particular, decreased . the permissions to low level flying in assigned regions. That's why the

  15. MORE ACTIVE AND SULFUR RESISTANT BIMETALLIC Pd-Ni CATALYSTS

    OpenAIRE

    Betti, Carolina; Carrara, Nicolás; Badano, Juan; Lederhos, Cecilia; Vera, Carlos; Quiroga, Mónica

    2018-01-01

    The influence of the kind of metal precursor and the sequence of impregnation on the properties of Pd-Ni catalysts was evaluated during the test reaction of selective hydrogenation of styrene to ethylbenzene by means of physicochemical characterization. The focus was put on the final hydrogenating activity and the resistance to deactivation by sulfided compounds (thiophene). The used techniques of characterization were ICP, XPS, XDR, TPR, CO chemisorption and TEM. XPS results indicated the pr...

  16. Low-level Radioactivity Measurements

    International Nuclear Information System (INIS)

    Churtgen, C.

    2007-01-01

    The low-level radioactivity measurements service performs measurements of alpha or beta emitters on various types of low-radioactivity samples (biological and environmental) from internal and external clients. to maintain and develop techniques concerning the measurement of low-level radioactivity of alpha and beta emitting radionuclides in environmental or biological samples; to measure these samples by means of low-background counters (liquid scintillators, proportional counters, ZnS counters and alpha-spectrometers); to support and advise the nuclear and non-nuclear industry on problems of radioactive contamination or low level radioactivity measurements; to maintain the quality assurance system according to the ISO17025 standard for which we obtained the Beltest accreditation in 1998; to assess the internal dose from occupational intakes of radionuclides for workers of the nuclear industry;

  17. Low-level waste disposal site selection demonstration

    International Nuclear Information System (INIS)

    Rogers, V.C.

    1984-01-01

    This paper discusses the results of recent studies undertaken at EPRI related to low-level waste disposal technology. The initial work provided an overview of the state of the art including an assessment of its influence upon transportation costs and waste form requirements. The paper discusses work done on the overall system design aspects and computer modeling of disposal site performance characteristics. The results of this analysis are presented and provide a relative ranking of the importance of disposal parameters. This allows trade-off evaluations to be made of factors important in the design of a shallow land burial facility. To help minimize the impact of a shortage of low-level radioactive waste disposal sites, EPRI is closely observing the development of bellweather projects for developing new sites. The purpose of this activity is to provide information about lessons learned in those projects in order to expedite the development of additional disposal facilities. This paper describes most of the major stems in selecting a low-level radioactive waste disposal site in Texas. It shows how the Texas Low-Level Radioactive Waste Disposal Authority started with a wide range of potential siting areas in Texas and narrowed its attention down to a few preferred sites. The parameters used to discriminate between large areas of Texas and, eventually, 50 candidate disposal sites are described, along with the steps in the process. The Texas process is compared to those described in DOE and EPRI handbooks on site selection and to pertinent NRC requirements. The paper also describes how an inventory of low-level waste specific to Texas was developed and applied in preliminary performance assessments of two candidate sites. Finally, generic closure requirements and closure operations for low-level waste facilities in arid regions are given

  18. Compositional and structural characterisation of Ni-phyllosilicates in hydrous silicate type Ni-laterite deposits

    OpenAIRE

    Villanova de Benavent, Cristina

    2015-01-01

    Ni-bearing Mg-phyllosilicates (commonly known as garnierites) are significant ore minerals in many Ni-laterite deposits worldwide. However, the characterisation of these mineral phases is complex, as well as their classification and nomenclature, due to their fine-grained nature, low crystallinity and frequent occurrence as mixtures. The aim of this study is to shed some light to the nature of the Ni-bearing Mg-phyllosilicates occurring at the Falcondo Ni-laterite. In this deposit, these ...

  19. Blade design and performance analysis on the horizontal axis tidal current turbine for low water level channel

    International Nuclear Information System (INIS)

    Chen, C C; Choi, Y D; Yoon, H Y

    2013-01-01

    Most tidal current turbine design are focused on middle and large scale for deep sea, less attention was paid in low water level channel, such as the region around the islands, coastal seas and rivers. This study aims to develop a horizontal axis tidal current turbine rotor blade which is applicable to low water level island region in southwest of Korea. The blade design is made by using BEMT(blade element momentum theory). The section airfoil profile of NACA63-415 is used, which shows good performance of lift coefficient and drag coefficient. Power coefficient, pressure and velocity distributions are investigated according to TSR by CFD analysis

  20. Transmutation and activation of stainless steel 316 SS in a thermal fusion reactor blanket

    International Nuclear Information System (INIS)

    Gruber, J.; Schneider, J.

    1977-10-01

    Using the program MATEXP (matrix exponential method) the influence of neutron flux is calculated for stainless steel 3s16 SS which is used as a structural material in a fusion reactor blanket (CTRD-I). The transmutations, activations and γ-dose rates are determined for an operation time of 20 years. Investigating the decay behaviour after operation time, we found that the long term activity and dose rate was mainly influenced by five nuclides: Fe55, Ni63, Ni59, Co60 and Nb94. (orig.) [de

  1. Magnetization reversal dynamics in exchange-coupled NiO - Co bilayers

    International Nuclear Information System (INIS)

    Camarero, J.; Pennec, Y.; Bonfim, M.; Vogel, J.; Pizzini, S.; Fontaine, A.; Cartier, M.; Fettar, F.; Dieny, B.

    2001-01-01

    We performed a detailed study of the magnetization reversal in polycrystalline exchange-coupled NiO/Co bilayers over 10 decades of field sweep rate dH/dt for different NiO and Co thicknesses. For all sweep rates and thicknesses, the symmetry of the hysteresis loops shows that an identical pinning strength has to be overcome in both directions of the reversal. At low dH/dt the reversal is governed by domain wall displacement while domain nucleation is dominant at higher ones. The dH/dt at which the transition between the two regimes takes place depends on the relative thickness of the NiO and Co layers. It increases (decreases) when the Co (NiO) thickness is increased. Experimentally, it was found that the energy barrier varies linearly with the square root of the area corresponding to the activation (Barkhausen) volume which is consistent with a random walk model of the coupling between antiferromagnetic and ferromagnetic layers. The results can be explained in terms of a thermally activated switching of the NiO magnetization dragged by the Co reversal. [copyright] 2001 American Institute of Physics

  2. Prussian Blue Analogues Derived Penroseite (Ni,Co)Se2 Nanocages Anchored on 3D Graphene Aerogel for Efficient Water Splitting

    KAUST Repository

    Xu, Xun; Liang, Hanfeng; Ming, Fangwang; Qi, Zhengbing; Xie, Yaqiang; Wang, Zhoucheng

    2017-01-01

    Efficient water splitting demands highly active, low cost, and robust electrocatalysts. In this study, we report the synthesis of penroseite (Ni,Co)Se2 nanocages anchored on 3D graphene aerogel using Prussian blue analogues as precursor and further their applications in overall water splitting electrolysis. The synergy between the high activity of (Ni,Co)Se2 and the good conductivity of graphene leads to superior performance of the hybrid toward the water splitting in basic solutions. The (Ni,Co)Se2-GA only requires a low cell voltage of 1.60 V to reach the current density of 10 mA cm-2, making the (Ni,Co)Se2-GA hybrid a competitive alternative to noble metal based catalysts for water splitting.

  3. Prussian Blue Analogues Derived Penroseite (Ni,Co)Se2 Nanocages Anchored on 3D Graphene Aerogel for Efficient Water Splitting

    KAUST Repository

    Xu, Xun

    2017-08-14

    Efficient water splitting demands highly active, low cost, and robust electrocatalysts. In this study, we report the synthesis of penroseite (Ni,Co)Se2 nanocages anchored on 3D graphene aerogel using Prussian blue analogues as precursor and further their applications in overall water splitting electrolysis. The synergy between the high activity of (Ni,Co)Se2 and the good conductivity of graphene leads to superior performance of the hybrid toward the water splitting in basic solutions. The (Ni,Co)Se2-GA only requires a low cell voltage of 1.60 V to reach the current density of 10 mA cm-2, making the (Ni,Co)Se2-GA hybrid a competitive alternative to noble metal based catalysts for water splitting.

  4. Microstructural investigations of Ni and Ni2Al3 coatings exposed in biomass power plants

    DEFF Research Database (Denmark)

    Wu, D. L.; Dahl, K. V.; Christiansen, T. L.

    2018-01-01

    The present work investigates the corrosion resistance of Ni and Ni2Al3 coated austenitic stainless steel (TP347H) tubes, which were exposed in a biomass-fired boiler with an outlet steam temperature of 540 °C for 6757 h. The Ni2Al3 coating was produced by electroplating Ni followed by low...... temperature pack cementation. After exposure, microstructural investigations were performed by light optical and electron microscopy (SEM-EDS). Electroplated Ni coatings were not protective in straw firing power plants and exhibited similar corrosion morphology as uncoated tubes. For Ni2Al3 coatings...

  5. Low-level Radioactivity Measurements

    International Nuclear Information System (INIS)

    Hurtgen, C.

    2002-01-01

    The objectives of the research performed in the area of low-level radioactivity measurements are (1) to maintain and develop techniques for the measurement of low-level environmental and biological samples, (2) to measure these samples by means of low-background counters (liquid scintillators, proportional counters, ZnS counters, alpha spectrometry), (3) to support and advise the nuclear and non-nuclear industry on problems of radioactive contamination and low-level radioactivity measurements; (4) to maintain and improve the quality assurance system according to the ISO17025 standard; and (5) to assess the internal dose from occupational intakes of radionuclides of workers of the nuclear industry. Progress and achievements in these areas in 2001 are reported

  6. Low-level Radioactivity Measurements

    International Nuclear Information System (INIS)

    Hurtgen, C.

    2001-01-01

    The objectives of the research performed in the area of low-level radioactivity measurements are (1) to maintain and develop techniques for the measurement of low-level environmental and biological samples, (2) to measure these samples by means of low-background counters (liquid scintillators, proportional counters, ZnS counters, alpha spectrometry), (3) to support and advice the nuclear and non-nuclear industry in matters concerning radioactive contamination and/or low-level radioactivity measurements; (4) to maintain the quality assurance system according to the EN45001/ISO17025 standard; and (5) to assess the internal dose from occupational intakes of radionuclides of workers of the nuclear industry. Progress and achievements in these areas in 2000 are reported

  7. Microbial activity of trench leachates from shallow-land, low-level radioactive waste disposal sites

    International Nuclear Information System (INIS)

    Francis, A.J.; Dobbs, S.; Nine, B.J.

    1980-01-01

    Trench leachate samples collected anoxically from shallow-land, low-level radioactive waste disposal sites were analyzed for total aerobic and anaerobic populations, sulfate reducers, denitrifiers, and methanogens. Among the several aerobic and anaerobic bacteria isolated, only Bacillus sp., Pseudomonas sp., Citrobacter sp., and Clostridium sp. were identified. Mixed bacterial cultures isolated from the trench leachates were able to grow anaerobically in trench leachates, which indicates that the radionuclides and organic chemicals present were not toxic to these bacteria. Changes in concentrations of several of the organic constituents of the waste leachate samples were observed due to anaerobic microbial activity. Growth of a mixed culture of trench-water bacteria in media containing a mixture of radionuclides, 60 Co, 85 Sr, and 134 137 Cs, was not affected at total activity concentrations of 2.6 x 10 2 and 2.7 x 10 3 pCi/ml

  8. Ni-Pt nanoparticles growing on metal organic frameworks (MIL-96) with enhanced catalytic activity for hydrogen generation from hydrazine at room temperature.

    Science.gov (United States)

    Wen, Lan; Du, Xiaoqiong; Su, Jun; Luo, Wei; Cai, Ping; Cheng, Gongzhen

    2015-04-07

    Well-dispersed bimetallic Ni-Pt nanoparticles (NPs) with different compositions have been successfully grown on the MIL-96 by a simple liquid impregnation method using NaBH4 as the reducing agent. Powder X-ray diffraction, transmission electron microscopy, energy-dispersive X-ray spectroscopy, N2 adsorption-desorption, and inductively coupled plasma-atomic emission spectroscopy measurements were employed to characterize the NiPt/MIL-96. Catalytic activity of NiPt/MIL-96 catalysts was tested in the hydrogen generation from the aqueous alkaline solution of hydrazine at room temperature. These catalysts are composition dependent on their catalytic activity, while Ni64Pt36/MIL-96 exhibits the highest catalytic activity among all the catalysts tested, with a turnover frequency value of 114.3 h(-1) and 100% hydrogen selectivity. This excellent catalytic performance might be due to the synergistic effect of the MIL-96 support and NiPt NPs, while NiPt NPs supported on other conventional supports, such as SiO2, carbon black, γ-Al2O3, poly(N-vinyl-2-pyrrolidone) (PVP), and the physical mixture of NiPt and MIL-96, all of them exhibit inferior catalytic activity compared to that of NiPt/MIL-96.

  9. Applications of low level liquid scintillation counting

    International Nuclear Information System (INIS)

    Noakes, J.E.

    1983-01-01

    Low level liquid scintillation counting is reviewed in terms of its present use and capabilities for measuring low activity samples. New areas of application of the method are discussed with special interest directed to the food industry and environmental monitoring. Advantages offered in the use of a low background liquid scintillation counter for the nuclear power industry and nuclear navy are discussed. Attention is drawn to the need for commercial development of such instrumentation to enable wider use of the method. A user clientele is suggested as is the required technology to create such a counter

  10. First-principles calculations for the elastic properties of Ni-base model superalloys: Ni/Ni3Al multilayers

    International Nuclear Information System (INIS)

    Yun-Jiang, Wang; Chong-Yu, Wang

    2009-01-01

    A model system consisting of Ni[001](100)/Ni 3 Al[001](100) multi-layers are studied using the density functional theory in order to explore the elastic properties of single crystal Ni-based superalloys. Simulation results are consistent with the experimental observation that rafted Ni-base superalloys virtually possess a cubic symmetry. The convergence of the elastic properties with respect to the thickness of the multilayers are tested by a series of multilayers from 2γ'+2γ to 10γ'+10γ atomic layers. The elastic properties are found to vary little with the increase of the multilayer's thickness. A Ni/Ni 3 Al multilayer with 10γ'+10γ atomic layers (3.54 nm) can be used to simulate the mechanical properties of Ni-base model superalloys. Our calculated elastic constants, bulk modulus, orientation-dependent shear modulus and Young's modulus, as well as the Zener anisotropy factor are all compatible with the measured results of Ni-base model superalloys R1 and the advanced commercial superalloys TMS-26, CMSX-4 at a low temperature. The mechanical properties as a function of the γ' phase volume fraction are calculated by varying the proportion of the γ and γ' phase in the multilayers. Besides, the mechanical properties of two-phase Ni/Ni 3 Al multilayer can be well predicted by the Voigt–Reuss–Hill rule of mixtures. (classical areas of phenomenology)

  11. Linear thermal expansion coefficient of cast Fe-Ni invar and Fe-Ni-Co superinvar alloys

    International Nuclear Information System (INIS)

    Ogorodnikova, O.M.; Chermenskaya, E.V.; Rabinovich, S.V.; Grachev, S.V.

    1999-01-01

    Cast invar alloys Fe-Ni (28-35 wt. % Ni) are investigated using metallography, dilatometry and X-ray methods as soon as the crystallization is completed and again after low-temperature treatment resulting in martensitic transformation in low nickel alloys. Nickel distribution in a cast superinvar Fe-32% Ni-4% Co is studied by means of X-ray spectrum microanalysis. The results obtained permit the correction of model concepts about cast invars and the estimate of a coefficient of linear expansion depending on phase composition and nickel microsegregation [ru

  12. Improved Sensitivity with Low Limit of Detection of a Hydrogen Gas Sensor Based on rGO-Loaded Ni-Doped ZnO Nanostructures.

    Science.gov (United States)

    Bhati, Vijendra Singh; Ranwa, Sapana; Rajamani, Saravanan; Kumari, Kusum; Raliya, Ramesh; Biswas, Pratim; Kumar, Mahesh

    2018-04-04

    We report enhanced hydrogen-gas-sensing performance of a Ni-doped ZnO sensor decorated with the optimum concentration of reduced graphene oxide (rGO). Ni-doped ZnO nanoplates were grown by radio frequency sputtering, rGO was synthesized by Hummer's method and decorated by the drop cast method of various concentration of rGO (0-1.5 wt %). The current-voltage characteristics of the rGO-loaded sensor are highly influenced by the loading concentration of rGO, where current conduction decreases and sensor resistance increases as the rGO concentration is increased up to 0.75 wt % because of the formation of various Schottky heterojunctions at rGO/ZnO interfaces. With the combined effect of more active site availability and formation of various p-n heterojunctions due to the optimum loading concentration of rGO (0.75 wt %), the sensor shows the maximum sensing response of ∼63.8% for 100 ppm hydrogen at moderate operating temperature (150 °C). The rGO-loaded sensors were able to detect a minimum of 1 ppm hydrogen concentration and showed high selectivity. However, a further increase in the rGO concentration (1.5 wt %) leads to the reduction of the relative response of hydrogen gas, ascribed to the formation of interconnections of rGO between electrodes. Therefore, it reduces the total resistance of the sensor and minimizes the effect of p-n heterojunction on sensor response.

  13. Plant growth and development vs. high and low levels of plant-beneficial heavy metal ions

    Directory of Open Access Journals (Sweden)

    Namira Arif

    2016-11-01

    Full Text Available Heavy metals (HMs exists in the environment in both forms as essential and non-essential. These HM ions enter in soil biota from various sources like natural and anthropogenic. Essential HMs such as cobalt (Co, copper (Cu, iron (Fe, manganese (Mn, molybdenum (Mo, nickel (Ni, and zinc (Zn plays a beneficial role in plant growth and development. At optimum level these beneficial elements improves the plant’s nutritional level and also several mechanisms essential for the normal growth and better yield of plants. The range of their optimality for land plants is varied. Plant uptake heavy metals as a soluble component or solubilized them by root exudates. While their presence in excess become toxic for plants that switches the plant’s ability to uptake and accumulate other nonessential elements. The increased amount of HMs within the plant tissue displays direct and indirect toxic impacts. Such direct effects are the generation of oxidative stress which further aggravates inhibition of cytoplasmic enzymes and damage to cell structures. Although, indirect possession is the substitution of essential nutrients at plant’s cation exchange sites. These ions readily influence role of various enzymes and proteins, arrest metabolism, and reveal phytotoxicity. On account of recent advancements on beneficial HMs ions Co, Cu, Fe, Mn, Mo, Ni, and Zn in soil-plant system, the present paper: overview the sources of HMs in soils and their uptake and transportation mechanism, here we have discussed the role of metal transporters in transporting the essential metal ions from soil to plants. The role played by Co, Cu, Fe, Mn, Mo, Ni, and Zn at both low and high level on the plant growth and development and the mechanism to alleviate metal toxicity at high level have been also discussed. At the end, on concluding the article we have also discussed the future perspective in respect to beneficial HM ions interaction with plant at both levels.

  14. SCC propagation and cessation behavior near the fusion boundary of dissimilar weld joint with Ni-based weld metal and low alloy steel

    International Nuclear Information System (INIS)

    Ishizawa, Makoto; Abe, Hiroshi; Watanabe, Yutaka

    2009-01-01

    The purpose of this study is to investigate the following items focused on the microstructure near the fusion boundary of dissimilar weld joint with Ni-based weld metal and low alloy steel; (1) Microstructural characteristics near the fusion boundary, (2) Dominant factor that makes crack retardation near the fusion boundary. Main conclusions can be summarized as follows; (1) From the results of CBB tests, it has been understood that the low alloy steel has no SCC susceptibility and that there is a difference in oxidation behavior between high and low sulfur containing low alloy steel, (2) In Alloy182/LAS sample, most of crack tips were located at the fusion boundary. It has been thought that crack become less active when crack reach at fusion boundary, (3) It has been suggested that the dominant factor of crack retardation is low SCC susceptibility of low alloy steel in high temperature water. (author)

  15. Low-level radioactive waste management: federal-state cooperation or confusion

    International Nuclear Information System (INIS)

    Choi, Y.H.

    1984-01-01

    This paper describes and analyzes the legislative history of the Low-Level Radioactive Waste Policy Act of 1980 and discusses major issues and problems resulting from the implementation of the Act. Five specific issues addressed in this paper are: what radioactive waste constitutes ''low-level radioactive waste'' within the meaning of the Act; what responsibilities, if any, do the states have to dispose of federal radioactive waste; what liabilities and protections govern the disposal of waste not generated in a disposal-site state (hereafter, the ''host state''); to what standards of care should generators of low-level radioactive waste be held, and by what authority should such generators be licensed and inspected; which disposal-site activities should be considered ''disposal,'' and which activities should be considered ''management,'' within the meaning of the Act, and what authority do the states have, under the Act, to engage in each activity, respectively. The federal government and state governments must solve these problems in order to implement the Act, and thus, to establish equity among the 50 states, and the interstate regional compacts

  16. Levels Of Mn, Fe, Ni, Cu, Zn And Cd, In Effluent From A Sewage ...

    African Journals Online (AJOL)

    This study reports the results of preliminary investigation of heavy metal levels-Ni, Cd, Fe, Zn, Cu and Mn; pH; temperature and electrical conductivity in effluents from a sewage treatment oxidation pond and its receiving stream. The heavy metal concentrations were determined with Inductively Coupled Plasma-Mass ...

  17. Low-level counting techniques in the underground laboratory `Felsenkeller` in Dresden

    Energy Technology Data Exchange (ETDEWEB)

    Niese, S [Nuclear Engineering and Analytics Rossendorf, Inc., Dresden (Germany); Koehler, M [Nuclear Engineering and Analytics Rossendorf, Inc., Dresden (Germany)

    1997-03-01

    Low radioactivity measurements are characterized by low detection limits. They are mainly determined by the background. The contribution of cosmic rays may be reduced drastically by installation of measurement devices in an underground laboratory. In 1982 we installed a chamber with a shield of ultramafic rock for low-level measurements within a cave of an old brewery named `Felsenkeller`. In this laboratory we used low-level {gamma}-spectrometry for the measurement of neutron activated samples of semiconductor silicon (Niese (1986)), of cosmic induced radioactivity in meteorites, chemically separated long-lived nuclides in low-level wastes, contaminated materials and of environmental samples. (orig./DG)

  18. Development for low-activation concrete design reducing radioactive waste

    International Nuclear Information System (INIS)

    Kimura, Ken-ichi; Kinno, Masaharu; Hasegawa, Akira

    2008-01-01

    Full text: Concrete is very valuable and inexpensive material, however it can be changed to be expensive and hard to deal with in use of a nuclear plant after long operation. One of the counter plans for the above is to use low-activation concrete instead of the ordinary concrete, that will reduce radioactive waste and could be even below clearance level in decommissioning and that is very useful in term of life cycle cost. Radioactive analysis showed that Co and Eu were the major target elements which decide the radioactivity level of reinforced concrete in decommissioning stage, and a several material were selected as a low-activation raw material from wide survey of raw materials for concrete (typically aggregates and cements). With the canditate of raw materials, several low-activation concrete were proposed for various portion of light water reactor plant, which reduction ratio were 1/10 to 1/30 which were mainly consist of limestone and low heat cement or white cement, and 1/100 to 1/300 which were mainly consist of alumina aggregate or quartz and high almina cement, comparing to the ordinary concrete in ΣDi/Ci unit, where 'Di' indicates concentration of each residual radioisotope, Ci defined by IAEA as a clearance level, and suffition of 'i' indicates each radioisotope. National funded project for development of low-activation design method for reduction of radioactive waste below clearance level were started from 2005 with aiming (1) development of a database on the content of target elements, which transform radioactive nuclides, in raw materials of reinforced concrete, (2) development of calculation tools for estimation of residual radioactivity of plant components, and (3) development of low-activation materials for concrete such as cements and reinforcing steel bars for structural components. For the optimized design for applying low-activation concrete to the reactor portion, effective evaluation of neutron spectrum in the certain portion including

  19. Effect of Ca, Ce or K oxide addition on the activity of Ni/SiO{sub 2} catalysts for the methane decomposition reaction

    Energy Technology Data Exchange (ETDEWEB)

    Zapata, Beatriz; Torres-Garcia, Enelio [Instituto Mexicano del Petroleo, Programa de Procesos y Reactores, Eje C. 152, Mexico, D.F., C.P. 07730 (Mexico); Valenzuela, Miguel A.; Palacios, Jorge [Instituto Politecnico Nacional-ESIQIE, Lab. Catalisis y Materiales, Zacatenco, Mexico, D.F., C.P. 07738 (Mexico)

    2010-11-15

    To increase the activity and stability of Ni/SiO{sub 2} catalysts, a series of Ni-Ca, Ni-K and Ni-Ce promoted catalysts were prepared by successive impregnations. The textural properties, reducibility and catalytic performance in the methane decomposition reaction were investigated. The catalyst containing 30 wt.% Ni and 30 wt.% cerium oxide greatly increased the conversion of methane (90% of equilibrium value) and improved the stability, whereas the Ni-K and Ni-Ca were less active and stable than the Ni/SiO{sub 2} catalyst. The results suggest that Ce addition prevents the sintering of nickel particles during reduction process maintaining a random distribution between the silica and cerium oxide improving the distribution and migration of deposited carbon. (author)

  20. Low level waste repositories

    International Nuclear Information System (INIS)

    Hill, P.R.H.; Wilson, M.A.

    1983-11-01

    Factors in selecting a site for low-level radioactive waste disposal are discussed. South Australia has used a former tailings dam in a remote, arid location as a llw repository. There are also low-level waste disposal procedures at the Olympic Dam copper/uranium project