National Library of Energy BETA

Sample records for ura ni um

  1. (ura avio teleco-mandado no tri-

    E-Print Network [OSTI]

    Instituto de Sistemas e Robotica

    Lançar um drone (ura avião teleco- mandado não tri- pulado) na Antárti- da e esperar que ele) controlou a ansie- dade e arriscou lançar o drone . O objetivo do 'Projeto 3D An- tártida' é ajudar'é perceber como o aumento da temperatura está a alterar o ecossistema A equipa lançou um drone de 20 mileuros

  2. Genome Rearrangement: A Planning Approach Tansel Uras and Esra Erdem

    E-Print Network [OSTI]

    Erdem, Esra

    Genome Rearrangement: A Planning Approach Tansel Uras and Esra Erdem Faculty of Engineering be reconstructed by pair- wise comparison of their entire genomes. Such a comparison can be quantified by determining the number of events that change the order of genes in a genome. Earlier Erdem and Tillier

  3. Genome Rearrangement and Planning: Revisited Tansel Uras and Esra Erdem

    E-Print Network [OSTI]

    Erdem, Esra

    Genome Rearrangement and Planning: Revisited Tansel Uras and Esra Erdem Faculty of Engineering be reconstructed by pair- wise comparison of their entire genomes. Such a comparison can be quantified by determining the number of events that change the order of genes in a genome. Earlier Erdem and Tillier

  4. Ni Ni: University of California - Los Angeles

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shinesSolarNew scholarshipThreeFebruary 2015 ESH&SCSU - EnergyNi Ni:

  5. Phosphorus content effect on the magnetoelectric properties of the NiP(Ni)/PZT/NiP(Ni) cylindrical layered composites

    E-Print Network [OSTI]

    Volinsky, Alex A.

    were polarized along the radial direction after electroplating a thin Ni layer on its inside and outside surfaces. The samples were pretreated with supersonic cleaning prior to Ni electroplating composite is shown else- where [13]. The final thickness of the inside and the outside coatings

  6. Influence of nuclear structure on sub-barrier hindrance in Ni+Ni fusion

    E-Print Network [OSTI]

    C. L. Jiang; K. E. Rehm; R. V. F. Janssens; H. Esbensen; I. Ahmad; B. B. Back; P. Collon; C. N. Davids; J. P. Greene; D. J. Henderson; G. Mukherjee; R. C. Pardo; M. Paul; T. O. Pennington; D. Seweryniak; S. Sinha; Z. Zhou

    2004-02-25

    Fusion-evaporation cross sections for $^{64}$Ni+$^{64}$Ni have been measured down to the 10 nb level. For fusion between two open-shell nuclei, this is the first observation of a maximum in the $S$-factor, which signals a strong sub-barrier hindrance. A comparison with the $^{58}$Ni+$^{58}$Ni, $^{58}$Ni+$^{60}$Ni, and $^{58}$Ni+$^{64}$Ni systems indicates a strong dependence of the energy where the hindrance occurs on the stiffness of the interacting nuclei.

  7. Sample & Assay Technologies Ni-NTA Superflow

    E-Print Network [OSTI]

    Lebendiker, Mario

    March 2007 Sample & Assay Technologies Ni-NTA Superflow Cartridge Handbook For manual or FPLCTM purification of His-tagged proteins #12;2 Ni-NTA Superflow Cartridge Handbook 03/2007 Trademarks: QIAGEN, are not to be considered unprotected by law. © 2007 QIAGEN, all rights reserved. #12;Ni-NTA Superflow Cartridge Handbook 03

  8. Monopole Strength in Ni-58 

    E-Print Network [OSTI]

    Youngblood, David H.; Lui, YW.

    1991-01-01

    Differential cross-section data from 0-degrees to 8-degrees for inelastic scattering of 129 MeV alpha particles exciting Ni-58 in the region of 14-22 MeV have been analyzed to explore the existence of monopole strength at approximately E(x) = 17 Me...

  9. Microstructural Characterization and Shape Memory Response of Ni-Rich NiTiHf and NiTiZr High Temperature Shape Memory Alloys 

    E-Print Network [OSTI]

    Evirgen, Alper

    2014-08-14

    NiTiHf and NiTiZr high temperature shape memory alloys (HTSMAs) have drawn a great deal of attention as cheaper alternatives to Pt, Pd and Au alloyed NiTi-based HTSMAs while NiTiZr alloys also providing at least 20% weight reduction then its Ni...

  10. UM NOVO MELHORAMENTO DE UM ALGORITMO PARA O PROBLEMA DOS K TRAJECTOS MAIS CURTOS

    E-Print Network [OSTI]

    Pascoal, Marta Margarida Braz

    UM NOVO MELHORAMENTO DE UM ALGORITMO PARA O PROBLEMA DOS K TRAJECTOS MAIS CURTOS Marta Pascoaly e de Queir'os Vieira Martins #12; Resumo 2 Resumo Um novo melhoramento de um algoritmo para o problema~ao decrescente de custos, K trajectos entre um dado par de n'os de uma rede. Os algoritmos conhecidos para

  11. Engineering the Martensitic Transformation Hysteresis of Ni-Rich NiTi Alloys 

    E-Print Network [OSTI]

    Franco, Brian Eelan

    2014-12-18

    The shape memory behavior in NiTi alloys can be exploited for a wide variety of applications that require active materials. The application dictates the transformation temperatures and hysteresis of the alloy. NiTi alloys ...

  12. Transformation Induced Fatigue of Ni-Rich NiTi Shape Memory Alloy Actuators 

    E-Print Network [OSTI]

    Schick, Justin Ryan

    2011-02-22

    In this work the transformation induced fatigue of Ni-rich NiTi shape memory alloys (SMAs) was investigated. The aerospace industry is currently considering implementing SMA actuators into new applications. However, before ...

  13. Simultaneous determination of Ni-63 and Ni-59 in radioactive wastes by liquid scintillation spectrometry 

    E-Print Network [OSTI]

    Kim, Esther Miyeun

    1988-01-01

    SIMULTANEOUS DETERMINATION OF Ni-63 AND Ni-59 IN RADIOACTIVE WASTES BY LIQUID SCINTILLATION SPECTROMETRY A Thesis by ESTHER MIYEUN KIM Submitted to the Office of Graduate Studies of Texas AgtM University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE May 1988 Major Subject: Health Physics SIMULTANEOUS DETERMINATION OF Ni-63 AND Ni-59 IN RADIOACTIVE WASTES BY LIQUID SCINTILLATION SPECTROMETRY A Thesis by ESTHER MIYEUN KIM Approved as to style...

  14. ³Ni² Clusterbank Replacement Project | Argonne Leadership Computing...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ni Clusterbank Replacement Project Event Sponsor: Argonne Leadership Computing Facility Seminar Start Date: Oct 20 2015 - 12:00pm BuildingRoom: Building 241Room D173...

  15. Magnetic structure near the Co/NiO(001) interface

    E-Print Network [OSTI]

    Arenholz, Elke

    2008-01-01

    are perpendicular to the NiO moments, hence demonstrating2+ L 3,2 XA spectra and NiO domain pattern (inset). SpectraThe 100 directions of the NiO(001) plane and the orientation

  16. UM-ASU Final Report

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnicalInformation4563 LLNL Small-scale Friction Sensitivity (BAM) Test . *UM-ASU Final

  17. Giant Quadrupole-Resonance in Ni Isotopes 

    E-Print Network [OSTI]

    Youngblood, David H.; Lui, YW; Garg, U.; Peterson, R. J.

    1992-01-01

    VOLUME 45, NUMBER 5 MAY 1992 Giant quadrupole resonance in Ni isotopes D. H. Youngblood and Y.-%. Lui Texas A&M UniUersity, College Station, Texas 77843 U. Garg University of Notre Dame, South Bend, Indiana 46556 R. J. Peterson University... (%) 58+12 76+14 78+14 90+16 Cp 0.80+0.04 0.84+0.04 0.82+0. 12 1.05+0. 10 2174 YOUNGBLOOD, LUI, GARG, AND PETERSON 45 1000 100 60Ni(n, n') E = 129 MeV 1 000 100 58Ni(n, n') 10 10 100 z' 1000 64Ni(n, n') 1OO~y 64 Ni 100 10 I s & & I...

  18. Enthalpy of mixing of liquid Ni-Zr and Cu-Ni-Zr alloys

    SciTech Connect (OSTI)

    Witusiewicz, V.T.; Sommer, F.

    2000-04-01

    Since the Al-Cu-Ni-Zr system is a basis for the production of bulk amorphous materials by rapid solidification techniques from the liquid state, it is of great scientific interest to determine the partial and the integral thermodynamic functions of liquid and undercooled liquid alloys. Such data, as was pointed out previously, are important in order to understand their extremely good glass-forming ability in multicomponent metallic systems as well as for processing improvements. In order to measure the thermodynamic properties of the Al-Cu-Ni-Zr quaternary, it is necessary to have reliable thermochemical data for its constituent canaries and ternaries first. In a series of articles, the authors have reported in detail the thermodynamic properties of liquid Al-Cu, Al-Ni, Cu-Ni, Cu-Zr, Al-Zr, Al-Cu-Ni, and Al-Cu-Zr alloys. This article deals with the direct calorimetric measurements of the partial and the integral enthalpies of mixing of liquid Ni-Zr and Cu-Ni-Zr alloys and the heat capacity of liquid Ni{sub 26}Zr{sub 74}. In a subsequent article, the authors will present similar data for the liquid ternary Al-Ni-Zr and for the liquid quaternary Al-Cu-Ni-Zr alloys.

  19. UM SMARTPHONE At agora, as tecnologias de

    E-Print Network [OSTI]

    Instituto de Sistemas e Robotica

    UM SMARTPHONE PARA CEGOS Até agora, as tecnologias de telemóvel disponíveis para os invisuais Instituto de Tecnologia de Rochester, em Nova lorque. #12;

  20. Spectromicroscopy study of interfacial Co/NiO(001)

    E-Print Network [OSTI]

    van der Laan, Gerrit

    2011-01-01

    study of interfacial Co/NiO(001) G. van der Laan, 1 N. D.the Co moments. The Ni moments in NiO prefer to be orienteda component of the moments in the NiO collinear to the Co.

  1. Layering and temperature-dependent magnetization and anisotropy of naturally produced Ni/NiO multilayers

    SciTech Connect (OSTI)

    Pappas, S. D.; Trachylis, D.; Velgakis, M. J.; Kapaklis, V.; Joensson, P. E.; Papaioannou, E. Th.; Delimitis, A.; Poulopoulos, P.; Fumagalli, P.; Politis, C.

    2012-09-01

    Ni/NiO multilayers were grown by magnetron sputtering at room temperature, with the aid of the natural oxidation procedure. That is, at the end of the deposition of each single Ni layer, air is let to flow into the vacuum chamber through a leak valve. Then, a very thin NiO layer ({approx}1.2 nm) is formed. Simulated x-ray reflectivity patterns reveal that layering is excellent for individual Ni-layer thickness larger than 2.5 nm, which is attributed to the intercalation of amorphous NiO between the polycrystalline Ni layers. The magnetization of the films, measured at temperatures 5-300 K, has almost bulk-like value, whereas the films exhibit a trend to perpendicular magnetic anisotropy (PMA) with an unusual significant positive interface anisotropy contribution, which presents a weak temperature dependence. The power-law behavior of the multilayers indicates a non-negligible contribution of higher order anisotropies in the uniaxial anisotropy. Bloch-law fittings for the temperature dependence of the magnetization in the spin-wave regime show that the magnetization in the multilayers decreases faster as a function of temperature than the one of bulk Ni. Finally, when the individual Ni-layer thickness decreases below 2 nm, the multilayer stacking vanishes, resulting in a dramatic decrease of the interface magnetic anisotropy and consequently in a decrease of the perpendicular magnetic anisotropy.

  2. Um quinto dos cursos tem taxa

    E-Print Network [OSTI]

    Instituto de Sistemas e Robotica

    . Os valores constam de um documento elaborado pela Direcção -Geral do Ensino Superior (DGES) - a que o desemprego entre os alunos di- plomados há mais de um ano, enquanto nas universidades esse valor cai para os bolsas + Superior para os alunos que escolham es- tudar nestas regiões e que vai arrancar no próximo ano

  3. Fig. 1. Magnetic hysteresis of NiO-doped NiF2 conversion materials

    E-Print Network [OSTI]

    Siegel, Paul H.

    member with CMRR, is leading her group to design, optimize and develop new materials for energy storage materials for higher energy lithium ion batteries (at least double the energy density of today's technologyFig. 1. Magnetic hysteresis of NiO-doped NiF2 conversion materials CMRR Newsletter Shirley Meng

  4. Electronic circuits having NiAl and Ni.sub.3 Al substrates

    DOE Patents [OSTI]

    Deevi, Seetharama C. (Midlothian, VA); Sikka, Vinod K. (Oak Ridge, TN)

    1999-01-01

    An electronic circuit component having improved mechanical properties and thermal conductivity comprises NiAl and/or Ni.sub.3 Al, upon which an alumina layer is formed prior to applying the conductive elements. Additional layers of copper-aluminum alloy or copper further improve mechanical strength and thermal conductivity.

  5. Antiproton Production in Ni+ni Collisions at 1.85 Gev/nucleon 

    E-Print Network [OSTI]

    LI, GQ; Ko, Che Ming.

    1994-01-01

    Antiproton production in Ni+Ni collisions at 1.85 GeV/nucleon is studied in the relativistic Vlasov-Uehling-Uhlenbeck model. The self-energies of the antiproton are determined from the nucleon self-energies by the G-parity transformation. Also...

  6. Photosensitivity of the Ni-A state of [NiFe] hydrogenase from Desulfovibrio vulgaris Miyazaki F with visible light

    SciTech Connect (OSTI)

    Osuka, Hisao; Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma-shi, Nara 630-0192 ; Shomura, Yasuhito; Komori, Hirofumi; Shibata, Naoki; Nagao, Satoshi; Higuchi, Yoshiki; CREST, JST, Gobancho, Chiyoda-ku, Tokyo 102-0076 ; Hirota, Shun; CREST, JST, Gobancho, Chiyoda-ku, Tokyo 102-0076

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer Ni-A state of [NiFe] hydrogenase showed light sensitivity. Black-Right-Pointing-Pointer New FT-IR bands were observed with light irradiation of the Ni-A state. Black-Right-Pointing-Pointer EPR g-values of the Ni-A state shifted upon light irradiation. Black-Right-Pointing-Pointer The light-induced state converted back to the Ni-A state under the dark condition. -- Abstract: [NiFe] hydrogenase catalyzes reversible oxidation of molecular hydrogen. Its active site is constructed of a hetero dinuclear Ni-Fe complex, and the oxidation state of the Ni ion changes according to the redox state of the enzyme. We found that the Ni-A state (an inactive unready, oxidized state) of [NiFe] hydrogenase from Desulfovibrio vulgaris Miyazaki F (DvMF) is light sensitive and forms a new state (Ni-AL) with irradiation of visible light. The Fourier transform infrared (FT-IR) bands at 1956, 2084 and 2094 cm{sup -1} of the Ni-A state shifted to 1971, 2086 and 2098 cm{sup -1} in the Ni-AL state. The g-values of g{sub x} = 2.30, g{sub y} = 2.23 and g{sub z} = 2.01 for the signals in the electron paramagnetic resonance (EPR) spectrum of the Ni-A state at room temperature varied for -0.009, +0.012 and +0.010, respectively, upon light irradiation. The light-induced Ni-AL state converted back immediately to the Ni-A state under dark condition at room temperature. These results show that the coordination structure of the Fe site of the Ni-A state of [NiFe] hydrogenase is perturbed significantly by light irradiation with relatively small coordination change at the Ni site.

  7. Preparation of PtNi Nanoparticles for the Electrocatalytic Oxidation of Methanol

    E-Print Network [OSTI]

    Deivaraj, T.C.

    Carbon supported PtNi nanoparticles were prepared by hydrazine reduction of Pt and Ni precursor salts under different conditions, namely by conventional heating (PtNi-1), by prolonged reaction at room temperature (PtNi-2) ...

  8. Blending Cr2O3 into a NiO-Ni electrocatalyst for sustained water splitting

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gong, Ming; Zhou, Wu; Kenney, Michael James; Kapusta, Rich; Cowley, Sam; Wu, Yingpeng; Lu, Bingan; Lin, Meng -Chang; Wang, Di -Yan; Yang, Jiang; et al

    2015-08-24

    The rising H2 economy demands active and durable electrocatalysts based on low-cost, earth-abundant materials for water electrolysis/photolysis. Here we report nanoscale Ni metal cores over-coated by a Cr2O3-blended NiO layer synthesized on metallic foam substrates. The Ni@NiO/Cr2O3 triphase material exhibits superior activity and stability similar to Pt for the hydrogen-evolution reaction in basic solutions. The chemically stable Cr2O3 is crucial for preventing oxidation of the Ni core, maintaining abundant NiO/Ni interfaces as catalytically active sites in the heterostructure and thus imparting high stability to the hydrogen-evolution catalyst. The highly active and stable electrocatalyst enables an alkaline electrolyzer operating at 20more »mA cm–2 at a voltage lower than 1.5 V, lasting longer than 3 weeks without decay. Thus, the non-precious metal catalysts afford a high efficiency of about 15 % for light-driven water splitting using GaAs solar cells.« less

  9. Energy absorption in Ni-Mn-Ga/ polymer composites

    E-Print Network [OSTI]

    Feuchtwanger, Jorge

    2006-01-01

    In recent years Ni-Mn-Ga has attracted considerable attention as a new kind of actuator material. Off-stoichiometric single crystals of Ni2MnGa can regularly exhibit 6% strain in tetragonal martensites and orthorhombic ...

  10. Carbon Nanotube Growth Using Ni Catalyst in Different Layouts

    E-Print Network [OSTI]

    Nguyen, H. Q.

    Vertically aligned carbon nanotubes have been grown using Ni as catalyst by plasma enhanced chemical vapor deposition system (PECVD) in various pre-patterned substrates. Ni was thermally evaporated on silicon substrates ...

  11. Oxygen Adsorption on Au–Ni(111) Surface Alloys

    E-Print Network [OSTI]

    Lee, Jae-Gook

    Molecular O[subscript 2] dissociates upon interaction with a Ni(111) surface, as the spatial and energetic overlap between the Ni 3d electrons and the O[subscript 2] antibonding orbitals is quite favorable. On a Au–Ni(111) ...

  12. High Temperature coatings based on {beta}-NiAI

    SciTech Connect (OSTI)

    Severs, Kevin

    2012-07-10

    High temperature alloys are reviewed, focusing on current superalloys and their coatings. The synthesis, characerization, and oxidation performance of a NiAl–TiB{sub 2} composite are explained. A novel coating process for Mo–Ni–Al alloys for improved oxidation performance is examined. The cyclic oxidation performance of coated and uncoated Mo–Ni–Al alloys is discussed.

  13. Giant monopole strength in Ni-58 

    E-Print Network [OSTI]

    Lui, YW; Clark, HL; Youngblood, David H.

    2000-01-01

    The strength distribution of the giant monopole resonance in Ni-58 has been measured from E-x = 10 to 35 MeV using small-angle scattering of 240-MeV alpha particles. E0 strength corresponding to 74(-12)(+22)% of the E0 EWSR was found between E-x...

  14. A Ni/surface-modified Diamond Composite Electroplating Coating on Superelastic NiTi Alloy as Potential Dental Bur Design

    E-Print Network [OSTI]

    Zheng, Yufeng

    A Ni/surface-modified Diamond Composite Electroplating Coating on Superelastic NiTi Alloy: Composite Electroplating; Surface-modified Diamond Particles; Interfacial Adhesion; NiTi alloy; Dental Bur into nickel coating, and its shank made of stainless steel. There are strong demands from the dentist

  15. In Situ XAS of Ni-W Hydrocracking Catalysts

    SciTech Connect (OSTI)

    Yang, N. [Argonne National Laboratory, Argonne, IL 60439 (United States); Mickelson, G. E.; Greenlay, N.; Bare, Simon R. [UOP LLC, Des Plaines, IL 60016 (United States); Kelly, S. D. [EXAFS Analysis, Bolingbrook, IL 60440 (United States)

    2007-02-02

    Ni-W based catalysts are very attractive in hydrotreating of heavy oil due to their high hydrogenation activity. In the present research, two catalyst samples, prepared by different methods, that exhibit significant differences in activity were sulfided in situ, and the local structure of the Ni and W were studied using X-ray absorption spectroscopy (XAS). The Ni XANES spectra were analyzed using a linear component fitting, and the EXAFS spectra of the WS2 platelets in the sulfided catalysts were modeled. The Ni and W are fully sulfided in the higher activity sample, and there are both unsulfided Ni ({approx}25%) and W (<10%) in the lower activity sample.

  16. NiW and NiRu Bimetallic Catalysts for Ethylene Steam Reforming: Alternative Mechanisms for Sulfur Resistance

    SciTech Connect (OSTI)

    Rangan, M.; Yung, M. M.; Medlin, J. W.

    2012-06-01

    Previous investigations of Ni-based catalysts for the steam reforming of hydrocarbons have indicated that the addition of a second metal can reduce the effects of sulfur poisoning. Two systems that have previously shown promise for such applications, NiW and NiRu, are considered here for the steam reforming of ethylene, a key component of biomass derived tars. Monometallic and bimetallic Al{sub 2}O{sub 3}-supported Ni and W catalysts were employed for ethylene steam reforming in the presence and absence of sulfur. The NiW catalysts were less active than Ni in the absence of sulfur, but were more active in the presence of 50 ppm H{sub 2}S. The mechanism for the W-induced improvements in sulfur resistance appears to be different from that for Ru in NiRu. To probe reasons for the sulfur resistance of NiRu, the adsorption of S and C{sub 2}H{sub 4} on several bimetallic NiRu alloy surfaces ranging from 11 to 33 % Ru was studied using density functional theory (DFT). The DFT studies reveal that sulfur adsorption is generally favored on hollow sites containing Ru. Ethylene preferentially adsorbs atop the Ru atom in all the NiRu (111) alloys investigated. By comparing trends across the various bimetallic models considered, sulfur adsorption was observed to be correlated with the density of occupied states near the Fermi level while C{sub 2}H{sub 4} adsorption was correlated with the number of unoccupied states in the d-band. The diverging mechanisms for S and C{sub 2}H{sub 4} adsorption allow for bimetallic surfaces such as NiRu that enhance ethylene binding without accompanying increases in sulfur binding energy. In contrast, bimetallics such as NiSn and NiW appear to decrease the affinity of the surface for both the reagent and the poison.

  17. Microstructures in rapidly solidified Ni-Mo alloys

    SciTech Connect (OSTI)

    Jayaraman, N.; Tewari, S.N.; Hemker, K.J.; Glasgow, T.K.

    1985-01-01

    Ni-Mo alloys of compositions ranging from pure Ni to Ni-40 at % Mo were rapidly solidified by chill block melt spinning in vacuum and were examined by optical metallography, x-ray diffraction and transmission electron microscopy. Rapid solidification resulted in an extension of molybdenum solubility in nickel from 28 to 37.5 at %. A number of different phases and microstructures were seen at different depths (solidification conditions) from the quenched surface of the melt spun ribbons.

  18. ARTIGO INTERNET Um milho de euros para estudar buracos negros

    E-Print Network [OSTI]

    Instituto de Sistemas e Robotica

    Técnico, acaba de receber um prestigioso prémio do European Research Council no valor de cerca de um/ Caixa Geral de Depósitos em 2008, e de uma bolsa Fulbright na Universidade do Mississippi em 2008

  19. Oxidation-resistant, solution-processed plasmonic Ni nanochain...

    Office of Scientific and Technical Information (OSTI)

    solution-processed plasmonic Ni nanochain-SiOsub x (x < 2) selective solar thermal absorbers Citation Details In-Document Search Title: Oxidation-resistant,...

  20. Fusion of radioactive $^{132}$Sn with $^{64}$Ni

    E-Print Network [OSTI]

    J. F. Liang; D. Shapira; J. R. Beene; C. J. Gross; R. L. Varner; A. Galindo-Uribarri; J. Gomez del Campo; P. A. Hausladen; P. E. Mueller; D. W. Stracener; H. Amro; J. J. Kolata; J. D. Bierman; A. L. Caraley; K. L. Jones; Y. Larochelle; W. Loveland; D. Peterson

    2007-04-05

    Evaporation residue and fission cross sections of radioactive $^{132}$Sn on $^{64}$Ni were measured near the Coulomb barrier. A large sub-barrier fusion enhancement was observed. Coupled-channel calculations including inelastic excitation of the projectile and target, and neutron transfer are in good agreement with the measured fusion excitation function. When the change in nuclear size and shift in barrier height are accounted for, there is no extra fusion enhancement in $^{132}$Sn+$^{64}$Ni with respect to stable Sn+$^{64}$Ni. A systematic comparison of evaporation residue cross sections for the fusion of even $^{112-124}$Sn and $^{132}$Sn with $^{64}$Ni is presented.

  1. The combustion synthesis of Ni-Ti shape memory alloys

    SciTech Connect (OSTI)

    Moore, J.J.; Yi, H.C. (Colorado School of Mines, Golden (USA))

    1990-08-01

    Combustion synthesis of Ni-Ti-series shape-memory alloys yields both time and energy savings over conventional production methods. The solidified combustion synthesis process products have been cold-rolled into plates which exhibit the shape-memory effect, and it was noted that shape-memory transition temperatures may be tailored over a -78 to 460 C temperature range through the substitution of a third element for Ni; this element may be Pd or Fe. Accounts are given of the experimental combustion syntheses of Ni-Ti-Fe and Ti-Ni-Pd. 24 refs.

  2. Enhanced photocatalytic efficiency in zirconia buffered n-NiO/p-NiO single crystalline heterostructures by nanosecond laser treatment

    SciTech Connect (OSTI)

    Molaei, R.; Bayati, M. R.; Alipour, H. M.; Nori, S.; Narayan, J.

    2013-06-21

    We report the formation of NiO based single crystalline p-n junctions with enhanced photocatalytic activity induced by pulsed laser irradiation. The NiO epilayers were grown on Si(001) substrates buffered with cubic yttria-stabilized zirconia (c-YSZ) by using pulsed laser deposition. The NiO/c-YSZ/Si heterostructures were subsequently laser treated by 5 pulses of KrF excimer laser (pulse duration = 25 Multiplication-Sign 10{sup -9} s) at lower energies. Microstructural studies, conducted by X-ray diffraction ({theta}-2{theta} and {phi} techniques) and high resolution transmission electron microscope, showed a cube-on-cube epitaxial relationship at the c-YSZ/Si interface; the epitaxial relationship across the NiO/c-YSZ interface was established as NiO<111 > Double-Vertical-Line Double-Vertical-Line c-YSZ<001> and in-plane NiO<110> Double-Vertical-Line Double-Vertical-Line c-YSZ<100>. Electron microscopy studies showed that the interface between the laser annealed and the pristine region as well as the NiO/c-YSZ interface was atomically sharp and crystallographically continuous. The formation of point defects, namely oxygen vacancies and NiO, due to the coupling of the laser photons with the NiO epilayers was confirmed by XPS. The p-type electrical characteristics of the pristine NiO epilayers turned to an n-type behavior and the electrical conductivity was increased by one order of magnitude after laser treatment. Photocatalytic activity of the pristine (p-NiO/c-YSZ/Si) and the laser-annealed (n-NiO/p-NiO/c-YSZ/Si) heterostructures were assessed by measuring the decomposition rate of 4-chlorophenol under UV light. The photocatalytic reaction rate constants were determined to be 0.0059 and 0.0092 min{sup -1} for the as-deposited and the laser-treated samples, respectively. The enhanced photocatalytic efficiency was attributed to the suppressed charge carrier recombination in the NiO based p-n junctions and higher electrical conductivity. Besides, the oxygen vacancies ease the adsorption of 4-chlorophenol, hydroxyl, and water molecules to the surface. Thus, n-NiO/p-NiO single crystalline catalysts can be introduced as a potent candidate to remediate the environmental pollution.

  3. Energies of Electronic States of Ni (II) Ion in NiO-Al2O3 Catalyst Prepared by Impregnation

    SciTech Connect (OSTI)

    Obadovic, D. Z.; Kiurski, J.; Marinkovic-Neducin, R. P.

    2007-04-23

    The behavior of NiO-Al2O3 catalysts is strongly dependent on the preparation method, as well as on pretreatment conditions. In the present work we investigated the influences of Ni(II) ion on NiO-Al2O3 catalysts properties due to the preparation by impregnation method. Based on experimental diffuse reflectance spectroscopy (DRS) data of electronic d-d transitions of Ni (II) promoter ion the energies of electronic states in spinel-like structure were calculated, and the most probable scheme of molecular orbital have been proposed.

  4. SF 6432-NI (04-95)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II) byMultidayAlumni > The EnergyRyanPhysics6/14/11 Page 1 of6432-NI

  5. Ni(II) Salts and 2-Propanol Effect Catalytic Reductive Coupling of Epoxides and Alkynes

    E-Print Network [OSTI]

    Beaver, Matthew G.

    A Ni-catalyzed reductive coupling of alkynes and epoxides using Ni(II) salts and simple alcohol reducing agents is described. Whereas previously reported conditions relied on Ni(cod)2 and Et3B, this system has several ...

  6. Continuous spin reorientation transition in epitaxially grown antiferromagnetic NiO thin films

    E-Print Network [OSTI]

    Li, J.

    2011-01-01

    along certain crystal axis [e.g. , NiO(100)]. Thusthe r 2 p S z 2, NiO ( dMgO ) / S NiO should be an approximation in the small limit.

  7. Solution-based thermodynamic modeling of the Ni-Al-Mo system...

    Office of Scientific and Technical Information (OSTI)

    (Al,Mo,Ni)0.75(Al,Mo,Ni)0.25. Thus, -fcc and -Ni3Al are modeled with a single Gibbs free energy function with appropriate treatment of the chemical ordering contribution. In...

  8. Synthesis and electrochemical properties of NiO nanospindles

    SciTech Connect (OSTI)

    Zhou, Hai; Lv, Baoliang; Xu, Yao; Wu, Dong

    2014-02-01

    Graphical abstract: NiO nanospindles with a different electrochemical activity as compared to those previous reports were synthesized via an agglomeration–dissolution–recrystallization growth process without the addition of any surfactant. - Highlights: • NiO nanospindles were synthesized without the addition of any surfactant. • The agglomeration–dissolution–recrystallization growth process was used to explain the precursors’ formation process of the spindle-like NiO. • As-obtained spindle-like NiO showed a different electrochemical activity as compared to those previous reports. - Abstract: NiO nanospindles were successfully synthesized via a hydrothermal and post-treatment method. The as-synthesized nanospindles were about several hundred nanometers in width and about one micrometer in length. X-ray diffraction (XRD) analysis revealed that the spindle-like structure was cubic NiO phase crystalline. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) analysis indicated that these NiO nanospindles were of single crystal nature. On the basis of time-dependent experiments, a possible agglomeration–dissolution–recrystallization growth process was proposed to explain the formation process of the spindle-like precursors. The cyclic voltammetry (CV) measurement showed that the as-prepared spindle-like NiO exhibited a pseudo-capacitance behavior.

  9. Lanthanide Al-Ni base Ericsson cycle magnetic refrigerants

    DOE Patents [OSTI]

    Gschneidner, K.A. Jr.; Takeya, Hiroyuki

    1995-10-31

    A magnetic refrigerant for a magnetic refrigerator using the Ericsson thermodynamic cycle comprises DyAlNi and (Gd{sub 0.54}Er{sub 0.46})AlNi alloys having a relatively constant {Delta}Tmc over a wide temperature range. 16 figs.

  10. Luminescence properties of the hybrid Si-Ni nanoparticles system

    E-Print Network [OSTI]

    Lalayan, A A; Movsesyan, H A

    2015-01-01

    The luminescence properties of the colloidal hybrid Si - Ni nanoparticles system fabricated in the pure water by pulsed laser ablation is considered. The red-shifted photoluminescence of this system because of the Stark effect in the Coulomb field of the charged Ni nanoparticles has been registered in the blue range of the spectrum.

  11. In situ XAS of Ni-W hydrocracking catalysts.

    SciTech Connect (OSTI)

    Yang, N.; Mickelson, G. E.; Greenlay, N.; Kelly, S. D.; Bare, S. R.; UOP LLC; EXAFS Analysis

    2007-01-01

    Ni-W based catalysts are very attractive in hydrotreating of heavy oil due to their high hydrogenation activity. In the present research, two catalyst samples, prepared by different methods, that exhibit significant differences in activity were sulfided in situ, and the local structure of the Ni and W were studied using X-ray absorption spectroscopy (XAS). The Ni XANES spectra were analyzed using a linear component fitting, and the EXAFS spectra of the WS{sub 2} platelets in the sulfided catalysts were modeled. The Ni and W are fully sulfided in the higher activity sample, and there are both unsulfided Ni ({approx}25%) and W (<10%) in the lower activity sample.

  12. Hydrides of CeNi/sub 5/, MmNi/sub 5/, Ca/sub 0/ /sub 2/(Ce/sub 0/ /sub 65/Mm/sub 0/ /sub 35/)/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Ce/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Mm/sub 0/ /sub 8/Ni/sub 5/, and mixed CeNi/sub 5//MmNi/sub 5/

    SciTech Connect (OSTI)

    Lakner, J.F.; Chow, T.S.

    1982-09-01

    Six intermetallic alloys (CeNi/sub 5/, MmNi/sub 5/, Ca/sub 0/ /sub 2/(Ce/sub 0/ /sub 65/Mm/sub 0/ /sub 35/)/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Ce/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Mm/sub 0/ /sub 8/Ni/sub 5/, and a mixed alloy, CeNi/sub 5//MmNi/sub 5/) were investigated with respect to their suitability to provide high hydrogen capacity and their potential for use in providing substantial hydrogen pressure at both low and high temperatures. A second phase of our investigation dealt with ball-milling and hydriding and dehydriding cycles to produce fine particles for use in hydride powder transfer studies. A summary of several Van't Hoff plots is also included for hydride-forming alloys.

  13. Effects of Cr and Ni on Interdiffusion and Reaction between U and Fe-Cr-Ni Alloys

    SciTech Connect (OSTI)

    K. Huang; Y. Park; L. Zhou; K.R. Coffey; Y.H. Sohn; B.H. Sencer; J. R. Kennedy

    2014-08-01

    Metallic U-alloy fuel cladded in steel has been examined for high temperature fast reactor technology wherein the fuel cladding chemical interaction is a challenge that requires a fundamental and quantitative understanding. In order to study the fundamental diffusional interactions between U with Fe and the alloying effect of Cr and Ni, solid-to-solid diffusion couples were assembled between pure U and Fe, Fe–15 wt.%Cr or Fe–15 wt.%Cr–15 wt.%Ni alloy, and annealed at high temperature ranging from 580 to 700 °C. The microstructures and concentration profiles that developed from the diffusion anneal were examined by scanning electron microscopy, and X-ray energy dispersive spectroscopy (XEDS), respectively. Thick U6Fe and thin UFe2 phases were observed to develop with solubilities: up to 2.5 at.% Ni in U6(Fe,Ni), up to 20 at.%Cr in U(Fe, Cr)2, and up to 7 at.%Cr and 14 at.% Ni in U(Fe, Cr, Ni)2. The interdiffusion and reactions in the U vs. Fe and U vs. Fe–Cr–Ni exhibited a similar temperature dependence, while the U vs. Fe–Cr diffusion couples, without the presence of Ni, yielded greater activation energy for the growth of intermetallic phases – lower growth rate at lower temperature but higher growth rate at higher temperature.

  14. The first principle study of Ni{sub 2}ScGa and Ni{sub 2}TiGa

    SciTech Connect (OSTI)

    Özduran, Mustafa; Turgut, Kemal; Arikan, Nihat; ?yigör, Ahmet; Candan, Abdullah

    2014-10-06

    We computed the electronic structure, elastic moduli, vibrational properties, and Ni{sub 2}TiGa and Ni{sub 2}ScGa alloys in the cubic L2{sub 1} structure. The obtained equilibrium lattice constants of these alloys are in good agreement with available data. In cubic systems, there are three independent elastic constants, namely C{sub 11}, C{sub 12} and C{sub 44}. We calculated elastic constants in L2{sub 1} structure for Ni{sub 2}TiGa and Ni{sub 2}ScGa using the energy-strain method. The electronic band structure, total and partial density of states for these alloys were investigated within density functional theory using the plane-wave pseudopotential method implemented in Quantum-Espresso program package. From band structure, total and projected density of states, we observed metallic characters of these compounds. The electronic calculation indicate that the predominant contributions of the density of states at Fermi level come from the Ni 3d states and Sc 3d states for Ni{sub 2}TiGa, Ni 3d states and Sc 3d states for Ni{sub 2}ScGa. The computed density of states at Fermi energy are 2.22 states/eV Cell for Ni{sub 2}TiGa, 0.76 states/eV Cell for Ni{sub 2}ScGa. The vibrational properties were obtained using a linear response in the framework at the density functional perturbation theory. For the alloys, the results show that the L2{sub 1} phase is unstable since the phonon calculations have imagine modes.

  15. Oblikoslovje v panonski nare?ni skupini

    E-Print Network [OSTI]

    Zorko, Zinka

    2010-01-01

    glagole: nes?, neseši, neset?; nesev?, neseta, nesete; nesem?, nesete, nes?t?; za atematske glagole: jesm?, jesi, jest?; jesv?, jesta, jeste; jesm?, jeste, s?t?. Slovenski knjižni jezik – tematska spregatev: nes-em, -eš, -e; -va, -ta, -ta; -mo, -te, -jo...; atematska spregatev: sem, si, je; sva, sta, sta; smo, ste, so. Prekmurš?ina (vsi glagoli se spregajo po temati?nem vzorcu): ne?s?:n, ne?s?:š, ne?s?:; ne?s?:va (m. sp.), ne?s?:ve (ž. sp.), ne?s?:ta, ne?s?:ta; ne?s?:mo, ne?s?:te, ne?s?:jo; ?sån, ?si, ?je; s...

  16. Ni/metal hydride secondary element

    DOE Patents [OSTI]

    Bauerlein, Peter

    2005-04-19

    A Ni/metal hydride secondary element having a positive nickel hydroxide electrode, a negative electrode having a hydrogen storage alloy, and an alkaline electrolyte, the positive electrode, provided with a three-dimensional metallic conductive structure, also contains an aluminum compound which is soluble in the electrolyte, in addition to nickel hydroxide and cobalt oxide. The aluminum compound is aluminum hydroxide and/or aluminum oxide, and the mass of the aluminum compound which is present in the positive bulk material mixture is 0.1 to 2% by weight relative to the mass of the nickel hydroxide which is present. In combination with aluminum hydroxide or aluminum oxide, the positive electrode further contains lanthanoid oxidic compounds Y.sub.2 O.sub.3, La.sub.2 O.sub.3 and Ca(OH).sub.2, as well as mixtures of these compounds.

  17. Usina do Trabalho do Ator: um teatro canibal

    E-Print Network [OSTI]

    Icle, Gilberto

    1999-10-01

    FALL 1999 97 Usina do Trabalho do Ator: um teatro canibal Gilberto lele O grupo Usina do Trabalho do Ator é um teatro-laboratório que vem trabalhando desde 1992, em Porto Alegre, estado do Rio Grande do Sul, no Brasil. O trabalho concentra... característico à arte produzida no Brasil. Somos um país gigantesco, descendemos de várias e ricas nações, possuímos manifestações culturais e folclóricas das mais diversas, talvez a aceitação desta diversidade seja nossa característica. Contudo...

  18. Graphene Monolayer Rotation on Ni(111) Facilities Bilayer Graphene Growth

    SciTech Connect (OSTI)

    Batzill M.; Sutter P.; Dahal, A.; Addou, R.

    2012-06-11

    Synthesis of bilayer graphene by chemical vapor deposition is of importance for graphene-based field effect devices. Here, we demonstrate that bilayer graphene preferentially grows by carbon-segregation under graphene sheets that are rotated relative to a Ni(111) substrate. Rotated graphene monolayer films can be synthesized at growth temperatures above 650 C on a Ni(111) thin-film. The segregated second graphene layer is in registry with the Ni(111) substrate and this suppresses further C-segregation, effectively self-limiting graphene formation to two layers.

  19. Effects of Process Conditions on Properties of Electroplated Ni Thin Films for Microsystem Applications

    E-Print Network [OSTI]

    Fleck, Norman A.

    Effects of Process Conditions on Properties of Electroplated Ni Thin Films for Microsystem, Southampton SO17 1QJ, United Kingdom The properties of electroplated Ni thin films have been systematically, micromotors, and pneumatic actuators.3-11 Ni and NiFe are the electroplated metals most commonly used for MEMS

  20. TiNi shape memory alloy thin films for microactuator application

    E-Print Network [OSTI]

    Fu, Yongqing

    TiNi films were prepared by co-sputtering TiNi target and a separate Ti target. Crystalline structure and phase transformation behaviors of TiNi films were investigated. Results showed that TiNi films had fine grain size ...

  1. Perpendicular magnetic anisotropy in ion beam sputtered Co/Ni multilayers

    E-Print Network [OSTI]

    Rasin, Boris

    2009-01-01

    Co/Ni multilayers display perpendicular magnetic anisotropy and have applications in magnetic devices that could lead to a large increase in the density of magnetic storage. Co/Ni 10-(2 Å Co/ 8Å Ni) and 10-(2 Å Co/ 4 Å Ni) ...

  2. Um Guia de Estudo Marco Aurelio Palumbo Cabral

    E-Print Network [OSTI]

    Cabral, Marco

    ´ALGEBRA Um Guia de Estudo 4a Edi¸c~ao Marco Aur´elio Palumbo Cabral mcabral@labma.ufrj.br Laborat

  3. Application of cluster-plus-glue-atom model to barrierless Cu–Ni–Ti and Cu–Ni–Ta films

    SciTech Connect (OSTI)

    Li, Xiaona, E-mail: lixiaona@dlut.edu.cn; Ding, Jianxin; Wang, Miao; Dong, Chuang [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024 (China); Chu, Jinn P. [Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China)

    2014-11-01

    To improve the thermal stability of copper and avoid its diffusion into surrounding dielectrics or interfacial reactions with them, the authors applied the cluster-plus-glue-atom model to investigate barrierless Cu–Ni–M (M?=?Ti or Ta) seed layers. The dissolution of the third element (Ti or Ta) in the Cu lattice with the aid of Ni significantly improved the thermal stability of the Cu seed layer. The appropriate M/Ni (M?=?Ti or Ta) ratio was selected to obtain a low resistivity: the resistivity was as low as 2.5??? cm for the (Ti{sub 1.5/13.5}Ni{sub 12/13.5}){sub 0.3}Cu{sub 99.7} film and 2.8??? cm for the (Ta{sub 1.1/13.1}Ni{sub 12/13.1}){sub 0.4}Cu{sub 99.6} film after annealing at 500?°C for 1?h. After annealing at 500?°C for 40?h, the two films remained stable without forming a Cu{sub 3}Si compound. The authors confirmed that the range of applications of the cluster-plus-glue-atom model could be extended. Therefore, a third element M with negative enthalpies of mixing with both Cu and Ni could be selected, under the premise that the mixing enthalpy of M–Ni is more negative than that of M–Cu.

  4. Ni(NiO)/single-walled carbon nanotubes composite: Synthesis of electro-deposition, gas sensing property for NO gas and density functional theory calculation

    SciTech Connect (OSTI)

    Li, Li; Zhang, Guo; Chen, Lei; Bi, Hong-Mei; Shi, Ke-Ying

    2013-02-15

    Graphical abstract: The Ni(NiO)/semiconducting single-walled carbon nanotubes composite collected from the cathode after electro-deposition shows a high sensitivity to low-concentration NO gas at room temperature (18 °C). Display Omitted Highlights: ? Ni(NiO) nanoparticles were deposited on semiconducting SWCNTs by electro-deposition. ? Ni(NiO)/semiconducting SWCNTs film shows a high sensitivity to NO gas at 18 °C. ?Theoretical calculation reveals electron transfer from SWCNTs to NO via Ni. -- Abstract: Single-walled carbon nanotubes which contains metallic SWCNTs (m-SWCNTs) and semiconducting SWCNTs (s-SWCNTs) have been obtained under electric arc discharge. Their separation can be effectively achieved by the electro-deposition method. The Ni(NiO)/s-SWCNTs composite was found on cathode where Ni was partially oxidized to NiO at ambient condition with Ni(NiO) nanoparticles deposited uniformly on the bundles of SWCNTs. These results were confirmed by Raman spectra, transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV–vis–NIR and TG characterizations. Furthermore, investigation of the gas sensing property of Ni(NiO)/s-SWCNTs composite film to NO gas at 18 °C demonstrated the sensitivity was approximately 5% at the concentration of 97 ppb. Moreover, density functional theory (DFT) calculations were performed to explore the sensing mechanism which suggested the adsorption of NO molecules onto the composite through N–Ni interaction as well as the proposition of electron transfer mechanisms from SWCNTs to NO via the Ni medium.

  5. $^{64}$Ni+$^{64}$Ni fusion reaction calculated with the density-constrained time-dependent Hartree-Fock formalism

    E-Print Network [OSTI]

    A. S. Umar; V. E. Oberacker

    2007-09-25

    We study fusion reactions of the $^{64}$Ni+$^{64}$Ni system using the density-constrained time-dependent Hartree-Fock (TDHF) formalism. In this formalism the fusion barriers are directly obtained from TDHF dynamics. In addition, we incorporate the entrance channel alignments of the slightly deformed (oblate) $^{64}$Ni nuclei due to dynamical Coulomb excitation. We show that alignment leads to a fusion barrier distribution and alters the naive picture for defining which energies are actually sub-barrier. We also show that core polarization effects could play a significant role in fusion cross section calculations.

  6. Electrodeposition of amorphous matrix Ni-W/Wp̳ composites

    E-Print Network [OSTI]

    Jenket, Donald R. (Donald Robert)

    2005-01-01

    An amorphous Ni-W alloy matrix was incorporated with W particulate through two types of electrodeposition. The plating bath for the electrodeposition contained nickel sulfate, sodium tungstate, sodium citrate, ammonium ...

  7. Double dumbbell shaped AgNi alloy by pulsed electrodeposition

    SciTech Connect (OSTI)

    Dhanapal, K.; Vasumathi, M.; Santhi, Kalavathy [Materials Science Centre, Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600 025 (India); Narayanan, V., E-mail: stephen-arum@hotmail.com; Stephen, A., E-mail: stephen-arum@hotmail.com [Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai-600 025 (India)

    2014-01-28

    Silver-Nickel is the well-known thermally immiscible system that makes them quite complex for the formation of alloy. This kind of alloy can be attained from electrodeposition method. In the present work, AgNi alloy was synthesized by pulsed electrodeposition in a single bath two electrode system with the use of anodic alumina membrane. The prepared AgNi alloy and pure Ag were characterized with X-ray Diffraction (XRD) for structural confirmation, Scanning Electron Microscopy (SEM) for morphological, and magnetic properties by Vibrating Sample Magnetometer, respectively. The X-ray Diffraction study shows the formation of cubic structure for pure Ag. SEM analysis reveals the double dumbbell morphology for AgNi alloy and spherically agglomeration for pure silver. Hysteresis behaviour from VSM measurement indicates that the AgNi alloy have good ferro-magnetic properties.

  8. TiNi-based thin films for MEMS applications

    E-Print Network [OSTI]

    Fu, Yongqing

    In this paper, some critical issues and problems in the development of TiNi thin films were discussed, including preparation and characterization considerations, residual stress and adhesion, frequency improvement, fatigue ...

  9. Grain boundary relaxation strengthening of nanocrystalline Ni–W alloys

    E-Print Network [OSTI]

    Rupert, Timothy J.

    The hardening effect caused by the relaxation of nonequilibrium grain boundary structure has been explored in nanocrystalline Ni–W alloys. First, the kinetics of relaxation hardening are studied, showing that higher annealing ...

  10. UM ALGORITMO EXATO PARA A OTIMIZAO DE CARTEIRAS DE INVESTIMENTO

    E-Print Network [OSTI]

    Gomes, Francisco A. M.

    UM ALGORITMO EXATO PARA A OTIMIZAÇÃO DE CARTEIRAS DE INVESTIMENTO COM RESTRIÇÕES DE CARDINALIDADE 162/2005 Villela, Pedro Ferraz V715a Um algoritmo exato para a otimização de carteiras de investimento. Método de Lemke. 3. Algoritmo Branch and Bound. 4. Restrições de cardinalidade. I. Gomes Neto, Francisco

  11. Anomalous magnetic behavior in nanocomposite materials of reduced graphene oxide-Ni/NiFe{sub 2}O{sub 4}

    SciTech Connect (OSTI)

    Kollu, Pratap E-mail: anirmalagrace@vit.ac.in; Prathapani, Sateesh; Varaprasadarao, Eswara K.; Mallick, Sudhanshu; Bahadur, D. E-mail: anirmalagrace@vit.ac.in; Santosh, Chella; Grace, Andrews Nirmala E-mail: anirmalagrace@vit.ac.in

    2014-08-04

    Magnetic Reduced Graphene Oxide-Nickel/NiFe{sub 2}O{sub 4} (RGO-Ni/NF) nanocomposite has been synthesized by one pot solvothermal method. Respective phase formations and their purities in the composite are confirmed by High Resolution Transmission Electron Microscope and X Ray Diffraction, respectively. For the RGO-Ni/NF composite material finite-size effects lead to the anomalous magnetic behavior, which is corroborated in temperature and field dependent magnetization curves. Here, we are reporting the behavior of higher magnetization values for Zero Field Cooled condition to that of Field Cooled for the RGO-Ni/NF nanocomposite. Also, the observed negative and positive moments in Hysteresis loops at relatively smaller applied fields (100?Oe and 200?Oe) are explained on the basis of surface spin disorder.

  12. Shape memory behavior of ultrafine grained NiTi and TiNiPd shape memory alloys 

    E-Print Network [OSTI]

    Kockar, Benat

    2009-05-15

    The cyclic instability in shape memory characteristics of NiTi-based shape memory alloys (SMAs), such as transformation temperatures, transformation and irrecoverable strains and transformation hysteresis upon thermal and ...

  13. Isotope correlations as a probe for freeze-out characterization: central 124Sn+64Ni, 112Sn+58Ni collisions

    E-Print Network [OSTI]

    E. Geraci; Reverse collaboration

    2003-10-15

    124Sn+64Ni and 112Sn+58Ni reactions at 35 AMeV incident energy were studied with the forward part of CHIMERA multi-detector. The most central collisions were selected by means of a multidimensional analysis. The characteristics of the source formed in the central collisions, as size, temperature and volume, were inspected. The measured isotopes of light fragments (3 <= Z <=8) were used to examine isotope yield ratios that provide information on the free neutron to proton densities.

  14. Electronic and structural influence of Ni by Pd substitution on the hydrogenation properties of TiNi

    SciTech Connect (OSTI)

    Emami, Hoda; Souques, Raphaeel; Crivello, Jean-Claude; Cuevas, Fermin

    2013-02-15

    In Ti (Ni,Pd) compounds, the hydrogen capacity and the stability of their hydrides decreases when Ni is partially substituted by larger in size Pd atoms. To understand this peculiar behaviour, the crystal structure of TiNi{sub 1-x}Pd{sub x}D{sub y} (x=0.1, 0.3 and 0.5) deuterides and the stability of TiNi{sub 1-x}Pd{sub x} (0{<=}x{<=}0.5) intermetallics and their hydrides have been investigated by both neutron diffraction experiments and Density Functional Theory (DFT) calculations. Neutron diffraction shows that at x=0.1 and 0.3, deuterium absorption induces tetragonal distortion in intermetallics sublattice whereas at x=0.5 the cubic symmetry is preserved. The structural properties and the heat of formation of TiNi{sub 1-x}Pd{sub x} (0{<=}x{<=}0.5) intermetallics and their hydrides have been determined by DFT. These results show that Pd substitution increases the stability of the intermetallics and decreases the stability of the hydrides, which confirms the rule of reverse stability. - Graphical abstract: Crystal structure of Ti(Ni,Pd)Hy hydrides in the I4/mmm space group. Highlights: Black-Right-Pointing-Pointer Neutron Diffraction and DFT calculations have been done on TiNi{sub 1-x}Pd{sub x}H{sub y} compounds. Black-Right-Pointing-Pointer Electronic effect of Pd substitution governs the hydrogenation properties in TiNi. Black-Right-Pointing-Pointer The rule of reverse stability in intermetallics/hydrides is observed with Pd substitution. Black-Right-Pointing-Pointer The hydrogen atoms in the I4/mmm structure prefer to occupy the 16n site.

  15. Solving the stellar 62Ni problem with AMS

    E-Print Network [OSTI]

    I. Dillmann; T. Faestermann; G. Korschinek; J. Lachner; M. Maiti; M. Poutivtsev; G. Rugel; S. Walter; F. Käppeler; M. Erhard; A. R. Junghans; C. Nair; R. Schwengner; A. Wagner

    2009-07-01

    An accurate knowledge of the neutron capture cross sections of 62,63Ni is crucial since both isotopes take key positions which affect the whole reaction flow in the weak s process up to A=90. No experimental value for the 63Ni(n,gamma) cross section exists so far, and until recently the experimental values for 62Ni(n,gamma) at stellar temperatures (kT=30 keV) ranged between 12 and 37 mb. This latter discrepancy could now be solved by two activations with following AMS using the GAMS setup at the Munich tandem accelerator which are also in perfect agreement with a recent time-of-flight measurement. The resulting (preliminary) Maxwellian cross section at kT=30 keV was determined to be 30keV = 23.4 +/- 4.6 mb. Additionally, we have measured the 64Ni(gamma,n)63Ni cross section close to threshold. Photoactivations at 13.5 MeV, 11.4 MeV and 10.3 MeV were carried out with the ELBE accelerator at Forschungszentrum Dresden-Rossendorf. A first AMS measurement of the sample activated at 13.5 MeV revealed a cross section smaller by more than a factor of 2 compared to NON-SMOKER predictions.

  16. Modified Ni-Cu catalysts for ethanol steam reforming

    SciTech Connect (OSTI)

    Dan, M.; Mihet, M.; Almasan, V.; Borodi, G.; Katona, G.; Muresan, L.; Lazar, M. D.

    2013-11-13

    Three Ni-Cu catalysts, having different Cu content, supported on ?-alumina were synthesized by wet co-impregnation method, characterized and tested in the ethanol steam reforming (ESR) reaction. The catalysts were characterized for determination of: total surface area and porosity (N{sub 2} adsorption - desorption using BET and Dollimer Heal methods), Ni surface area (hydrogen chemisorption), crystallinity and Ni crystallites size (X-Ray Diffraction), type of catalytic active centers (Hydrogen Temperature Programmed Reduction). Total surface area and Ni crystallites size are not significantly influenced by the addition of Cu, while Ni surface area is drastically diminished by increasing of Cu concentration. Steam reforming experiments were performed at atmospheric pressure, temperature range 150-350°C, and ethanol - water molar ration of 1 at 30, using Ar as carrier gas. Ethanol conversion and hydrogen production increase by the addition of Cu. At 350°C there is a direct connection between hydrogen production and Cu concentration. Catalysts deactivation in 24h time on stream was studied by Transmission Electron Microscopy (TEM) and temperature-programmed reduction (TPR) on used catalysts. Coke deposition was observed at all studied temperatures; at 150°C amorphous carbon was evidenced, while at 350°C crystalline, filamentous carbon is formed.

  17. Superior performance of Ni-W-Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rodriguez, Jose A.; Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; Johnson-Peck, Aaron C.; Zhao, Fuzhen; Michorczyk, Piotr; Kubacka, Anna; Stach, Eric A.; Fernandez-Garica, Marcos; et al

    2014-11-26

    The ethanol steam reforming (ESR) reaction was studied over a series of Ni-W-Ce oxide catalysts. The structures of the catalysts were characterized using in-situ techniques including X-ray diffraction, Pair Distribution Function, X-ray absorption fine structure and transmission electron microscopy; while possible surface intermediates for the ESR reaction were investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. In these materials, all the W and part of the Ni were incorporated into the CeO? lattice, with the remaining Ni forming highly dispersed nano NiO (more »The Ni-W-Ce systeme exhibited a much larger lattice strain than those seen for Ni-Ce and W-Ce. Synergistic effects between Ni and W inside ceria produced a substantial amount of defects and O vacancies that led to high catalytic activity, selectivity and stability (i.e. resistance to coke formation) during ethanol steam reforming.« less

  18. U-M AFRICAN PRESIDENTIAL SCHOLARS PROGRAM RESEARCH SYMPOSIUM II

    E-Print Network [OSTI]

    Kamat, Vineet R.

    study of trace element of iron ore samples from Tokada Mines in northeastern Liberia in two acid minutes. Renee Gerring University of Liberia, Monrovia, Liberia U-M Mentor-Colleague: Dimitrios Zekkos

  19. Priorities, Themes, & Strategic Objectives President Wolfe's UM System Priorities

    E-Print Network [OSTI]

    Missouri-Rolla, University of

    Priorities, Themes, & Strategic Objectives President Wolfe's UM System Priorities I. Strategic 2012-2013 Strategic Objectives I. Strategic Planning Enhancement Refine process to align with campus parents, alumni, employers, and the local community. IV. Resource Management/Operational Excellence Focus

  20. Mitigation of Sulfur Poisoning of Ni/Zirconia SOFC Anodes by Antimony and Tin

    SciTech Connect (OSTI)

    Marina, Olga A.; Coyle, Christopher A.; Engelhard, Mark H.; Pederson, Larry R.

    2011-02-28

    Surface Ni/Sb and Ni/Sb alloys were found to efficiently minimize the negative effects of sulfur on the performance of Ni/zirconia anode-supported solid oxide fuel cells (SOFC). Prior to operating on fuel gas containing low concentrations of H2S, the nickel/zirconia anodes were briefly exposed to antimony or tin vapor, which only slightly affected the SOFC performance. During the subsequent exposures to 1 and 5 ppm H2S, increases in anodic polarization losses were minimal compared to those observed for the standard nickel/zirconia anodes. Post-test XPS analyses showed that Sb and Sn tended to segregate to the surface of Ni particles, and further confirmed a significant reduction of adsorbed sulfur on the Ni surface in Ni/Sn and Ni/Sb samples compared to the Ni. The effect may be the result of weaker sulfur adsorption on bimetallic surfaces, adsorption site competition between sulfur and Sb or Sn on Ni, or other factors. The use of dilute binary alloys of Ni-Sb or Ni-Sn in the place of Ni, or brief exposure to Sb or Sn vapor, may be effective means to counteract the effects of sulfur poisoning in SOFC anodes and Ni catalysts. Other advantages, including suppression of coking or tailoring the anode composition for the internal reforming, are also expected.

  1. Bimetallic Fe-Ni Oxygen Carriers for Chemical Looping Combustion

    SciTech Connect (OSTI)

    Bhavsar, Saurabh; Veser, Goetz

    2013-11-06

    The relative abundance, low cost, and low toxicity of iron make Fe-based oxygen carriers of great interest for chemical looping combustion (CLC), an emerging technology for clean and efficient combustion of fossil and renewable fuels. However, Fe also shows much lower reactivity than other metals (such as Ni and Cu). Here, we demonstrate strong improvement of Fe-based carriers by alloying the metal phase with Ni. Through a combination of carrier synthesis and characterization with thermogravimetric and fixed-bed reactor studies, we demonstrate that the addition of Ni results in a significant enhancement in activity as well as an increase in selectivity for total oxidation. Furthermore, comparing alumina and ceria as support materials highlights the fact that reducible supports can result in a strong increase in oxygen carrier utilization.

  2. Healing of graphene on single crystalline Ni(111) films

    SciTech Connect (OSTI)

    Zeller, Patrick; Wintterlin, Joost; Speck, Florian; Ostler, Markus; Weinl, Michael; Schreck, Matthias; Seyller, Thomas

    2014-11-10

    The annealing of graphene layers grown on 150?nm thick single crystal Ni(111) films was investigated in situ by low energy electron microscopy and photoemission electron microscopy. After growth, by means of chemical vapor deposition of ethylene, the graphene layers consist of several domains showing different orientations with respect to the underlying Ni surface and also of small bilayer areas. It is shown that, in a controlled process, the rotated domains can be transformed into lattice-aligned graphene, and the bilayer areas can be selectively dissolved, so that exclusively the aligned monolayer graphene is obtained. The ordering mechanism involves transport of C atoms across the surface and solution in the bulk.

  3. Synthesis, electrochemistry and First Principles Calculation studies of layered Li-Ni-Ti-O compounds

    E-Print Network [OSTI]

    Kang, Kisuk

    New layered cathode materials, Li?.?Ni?.??Ti?.??O?, were synthesized by means of ion-exchange from Na?.?Ni?.??Ti?.??O?. The degree of cation disordering in the material depends critically on the synthesis conditions. Longer ...

  4. Effect of Aging Heat Treatments on Ni52Ti48 Shape Memory Alloy 

    E-Print Network [OSTI]

    Akin, Erhan

    2011-10-21

    Ni-rich NiTi shape memory alloys (SMAs) are capable of attaining a wide range of transformation temperatures depending on the heat treatment conditions and superior thermo-mechanical cycling stability, which are desired for repeated solid...

  5. Mechanism(s) of Ni Sorption on Al-Hydroxy-Interlayered Vermiculite Using Time-Resolved EXAFS

    E-Print Network [OSTI]

    Sparks, Donald L.

    Mechanism(s) of Ni Sorption on Al-Hydroxy-Interlayered Vermiculite Using Time-Resolved EXAFS D. R sorbed and the mechanism of Ni sorption. #12;

  6. Superior performance of Ni-W-Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

    SciTech Connect (OSTI)

    Rodriguez, Jose A.; Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; Johnson-Peck, Aaron C.; Zhao, Fuzhen; Michorczyk, Piotr; Kubacka, Anna; Stach, Eric A.; Fernandez-Garica, Marcos; Senanayake, Sanjaya D.

    2014-11-26

    The ethanol steam reforming (ESR) reaction was studied over a series of Ni-W-Ce oxide catalysts. The structures of the catalysts were characterized using in-situ techniques including X-ray diffraction, Pair Distribution Function, X-ray absorption fine structure and transmission electron microscopy; while possible surface intermediates for the ESR reaction were investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. In these materials, all the W and part of the Ni were incorporated into the CeO? lattice, with the remaining Ni forming highly dispersed nano NiO (< 2 nm) outside the Ni-W-Ce oxide structure. The nano NiO was reduced to Ni under ESR conditions. The Ni-W-Ce systeme exhibited a much larger lattice strain than those seen for Ni-Ce and W-Ce. Synergistic effects between Ni and W inside ceria produced a substantial amount of defects and O vacancies that led to high catalytic activity, selectivity and stability (i.e. resistance to coke formation) during ethanol steam reforming.

  7. Superior performance of Ni-W-Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rodriguez, Jose A. [Brookhaven National Lab. (BNL), Upton, NY (United States); State Univ. of New York Stony Brook, Stony Brook, NY (United States); Liu, Zongyuan [Brookhaven National Lab. (BNL), Upton, NY (United States); State Univ. of New York Stony Brook, Stony Brook, NY (United States); Xu, Wenqian [Brookhaven National Lab. (BNL), Upton, NY (United States); Yao, Siyu [Brookhaven National Lab. (BNL), Upton, NY (United States); Johnson-Peck, Aaron C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zhao, Fuzhen [Brookhaven National Lab. (BNL), Upton, NY (United States); Michorczyk, Piotr [Inst. de Catalisis y Petroleoquimica, Madrid (Spain); Kubacka, Anna [Inst. de Catalisis y Petroleoquimica, Madrid (Spain); Stach, Eric A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fernandez-Garica, Marcos [State Univ. of New York Stony Brook, Stony Brook, NY (United States); Senanayake, Sanjaya D. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-01-01

    The ethanol steam reforming (ESR) reaction was studied over a series of Ni-W-Ce oxide catalysts. The structures of the catalysts were characterized using in-situ techniques including X-ray diffraction, Pair Distribution Function, X-ray absorption fine structure and transmission electron microscopy; while possible surface intermediates for the ESR reaction were investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. In these materials, all the W and part of the Ni were incorporated into the CeO? lattice, with the remaining Ni forming highly dispersed nano NiO (< 2 nm) outside the Ni-W-Ce oxide structure. The nano NiO was reduced to Ni under ESR conditions. The Ni-W-Ce systeme exhibited a much larger lattice strain than those seen for Ni-Ce and W-Ce. Synergistic effects between Ni and W inside ceria produced a substantial amount of defects and O vacancies that led to high catalytic activity, selectivity and stability (i.e. resistance to coke formation) during ethanol steam reforming.

  8. XES Nanoprobe for Hard X-Ray Region: Mitigating Degradation in Ni-ZEBRA Batteries Research Team: Mark Bowden, Kyle Alvine, Nancy Hess, Guosheng Li, Tamas Varga

    E-Print Network [OSTI]

    XES Nanoprobe for Hard X-Ray Region: Mitigating Degradation in Ni-ZEBRA Batteries Research Team scientific understanding of link between Ni-NiCl2 ZEBRA battery cycle degradation and FeS additive Chemical battery performance by poisoning Ni surfaces ­ optimizing Ni/NiCl2 distributions and conductive pathways

  9. Shape memory response of ni2mnga and nimncoin magnetic shape memory alloys under compression 

    E-Print Network [OSTI]

    Brewer, Andrew Lee

    2009-05-15

    In this study, the shape memory response of Ni2MnGa and NiMnCoIn magnetic shape memory alloys was observed under compressive stresses. Ni2MnGa is a magnetic shape memory alloy (MSMA) that has been shown to exhibit fully ...

  10. Oxygen Reduction Activity of PtxNi1-x Alloy Nanoparticles on Multiwall Carbon Nanotubes

    E-Print Network [OSTI]

    Kim, Junhyung

    PtxNi1 - x nanoparticles (Pt:Ni; 1:0, 4:1, 3:1 and 0.7:1) of ~5 nm, were synthesized on carboxylic acid-functionalized multiwall carbon nanotubes (PtxNi1 - x NPs/MWNT). The oxygen reduction reaction (ORR) activity measurements ...

  11. CO2 hydrogenation to formic acid on Ni(110) Guowen Peng a

    E-Print Network [OSTI]

    Sibener, Steven

    CO2 hydrogenation to formic acid on Ni(110) Guowen Peng a , S.J. Sibener b , George C. Schatz c of subsurface H for hydrogenating carbon dioxide (CO2) on Ni(110). The energetics of surface and subsurface H reacting with surface CO2 to form for- mate, carboxyl, and formic acid on Ni(110) is systematically studied

  12. Which Optical Smoothing for LMJ and NIF ? Centre de Mathmatiques Appliques, CNRS URA 756,

    E-Print Network [OSTI]

    Garnier, Josselin

    pattern relies on the same general concept. First a broadband pulse is generated either by a naturally components so as to produce on target a moving speckle pattern (with Gaussian statistics for the electric field). However, if the principles are shared in common, it should be emphasized that the values

  13. Investigation of Ni Sorption on Pyrophyllite: An XAFS Study

    E-Print Network [OSTI]

    Sparks, Donald L.

    , * , G E R A L D I N E M . L A M B L E , A N D D O N A L D L . S P A R K S Department of Plant and SoilInvestigation of Ni Sorption on Pyrophyllite: An XAFS Study A N D R E M . S C H E I D E G G E R

  14. Semantic Sensor Net: An Extensible Framework Lionel M. Ni1

    E-Print Network [OSTI]

    Liu, Yunhao

    (MEMS) have led to the wide deployment of large-scale wireless sensor networks (WSN), which promisesSemantic Sensor Net: An Extensible Framework Lionel M. Ni1 , Yanmin Zhu1 , Jian Ma1 , Minglu Li2-ml@cs.sjtu.edu.cn Abstract. Existing approaches for sensor networks suffer from a number of critical drawbacks. First

  15. High strain rate deformation of NiAl

    SciTech Connect (OSTI)

    Maloy, S.A.; Gray, G.T. III; Darolia, R.

    1994-07-01

    NiAl is a potential high temperature structural material. Applications for which NiAl is being considered (such as rotating components in jet engines) requires knowledge of mechanical properties over a wide range of strain rates. Single crystal NiAl (stoichiometric and Ni 49.75Al 0.25Fe) has been deformed in compression along [100] at strain rates of 0.001, 0.1/s and 2000/s and temperatures of 76,298 and 773K. <111> slip was observed after 76K testing at a strain rate of 0.001/s and 298K testing at a strain rate of 2000/s. Kinking was observed after deformation at 298K and a strain rate of 0.001/s and sometimes at 298 K and a strain rate of 0.1/s. Strain hardening rates of 8200 and 4000 MPa were observed after 773 and 298K testing respectively, at a strain rate of 2000/s. Results are discussed in reference to resulting dislocation substructure.

  16. 90° magnetic coupling in a NiFe/FeMn/biased NiFe multilayer spin valve component investigated by polarized neutron reflectometry

    SciTech Connect (OSTI)

    Callori, S. J., E-mail: sara.callori@ansto.gov.au; Bertinshaw, J. [School of Physics, The University of New South Wales, Sydney, New South Wales 2052 (Australia); Bragg Institute, Australian Nuclear Science and Technology Organization, Lucas Heights, New South Wales 2234 (Australia); Cortie, D. L. [The Institute for Superconducting and Electronic Materials, The University of Wollongong, Wollongong, New South Wales 2522 (Australia); Bragg Institute, Australian Nuclear Science and Technology Organization, Lucas Heights, New South Wales 2234 (Australia); Cai, J. W., E-mail: jwcai@aphy.iphy.ac.cn; Zhu, T. [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Le Brun, A. P. [Bragg Institute, Australian Nuclear Science and Technology Organization, Lucas Heights, New South Wales 2234 (Australia); Klose, F. [Bragg Institute, Australian Nuclear Science and Technology Organization, Lucas Heights, New South Wales 2234 (Australia); Department of Physics and Materials Science, City University of Hong Kong (Hong Kong)

    2014-07-21

    We have observed 90° magnetic coupling in a NiFe/FeMn/biased NiFe multilayer system using polarized neutron reflectometry. Magnetometry results show magnetic switching for both the biased and free NiFe layers, the latter of which reverses at low applied fields. As these measurements are only capable of providing information about the total magnetization within a sample, polarized neutron reflectometry was used to investigate the reversal behavior of the NiFe layers individually. Both the non-spin-flip and spin-flip neutron reflectometry signals were tracked around the free NiFe layer hysteresis loop and were used to detail the evolution of the magnetization during reversal. At low magnetic fields near the free NiFe coercive field, a large spin-flip signal was observed, indicating magnetization aligned perpendicular to both the applied field and pinned layer.

  17. Low-temperature magnetization in Ni-rich gamma-Ni100-x-yFexVy alloys 

    E-Print Network [OSTI]

    Chakraborty, S.; Mukherjee, GD; Rathnayaka, KDD; Naugle, Donald G.; Majumdar, AK.

    2000-01-01

    Detailed studies of the temperature dependence of the spontaneous magnetization have been made in eight different compositions of gamma-Ni100-x-yFexVy (4 less than or equal to x less than or equal to 17; 2 less than or equal to y less than or equal...

  18. Probing antiferromagnetism in NiMn/Ni/(Co)/Cu3Au(001) single-crystalline epitaxial thin films

    E-Print Network [OSTI]

    Kuch, Wolfgang

    hexagonal-close- packed and composition-modulated atomic layer stacking Appl. Phys. Lett. 102, 012407 (2013-of-plane (OoP) as well as in-plane (IP) magnetized Ni films, the latter stabilized by Co under-layer deposition) Electron molecular beam epitaxy: Layer-by-layer growth of complex oxides via pulsed electron

  19. First-principles investigations of Ni3Al(111) and NiAl(110) surfaces at metal dusting conditions

    SciTech Connect (OSTI)

    Saadi, Souheil

    2011-03-01

    We investigate the structure and surface composition of the {gamma}{prime}-Ni{sub 3}Al(111) and {beta}-NiAl(110) alloy surfaces at conditions relevant for metal dusting corrosion related to catalytic steam reforming of natural gas. In regular service as protective coatings, nickel-aluminum alloys are protected by an oxide scale, but in case of oxide scale spallation, the alloy surface may be directly exposed to the reactive gas environment and vulnerable to metal dusting. By means of density functional theory and thermochemical calculations for both the Ni{sub 3}Al and NiAl surfaces, the conditions under which CO and OH adsorption is to be expected and under which it is inhibited, are mapped out. Because CO and OH are regarded as precursors for nucleating graphite or oxide on the surfaces, phase diagrams for the surfaces provide a simple description of their stability. Specifically, this study shows how the CO and OH coverages depend on the steam to carbon ratio (S/C) in the gas and thereby provide a ranking of the carbon limits on the different surface phases.

  20. STRUCTURAL DETERMINATION OF MOLECULAR OVERLAYER SYSTEMS WITH NORMAL PHOTOELECTRON DIFFRACTION: c(2x2)CO-Ni(001) AND (/3 x /3)R30| Co-Ni(111)

    E-Print Network [OSTI]

    Kevan, S.D.

    2012-01-01

    electron diffraction (LEED), for subsequent, quantitativeadsorption system and because LEED structure analysis has° CO-Ni(lll) system, for which no LEED data presently exist.

  1. The thermal stability of TiB[sub 2] in Ni-43 a% Al

    SciTech Connect (OSTI)

    Korinko, P.S. (General Motors, Indianapolis, IN (United States). Allison Gas Turbine Div.); Duquette, D.J. (Rensselaer Polytechnic Inst., Troy, NY (United States))

    1994-02-01

    The intermetallic compound NiAl has been suggested for use as a matrix for high temperature composites. Interest in this compound is derived from its low density compared to conventional superalloys, high melting point, and excellent oxidation resistance. It has been demonstrated that a composite of stoichiometric NiAl and TiB[sub 2] is stable when exposed at elevated temperatures for extended periods of time. However, it has been shown that a composite consisting of Ni[sub 3]Al and TiB[sub 2] is not stable in the same temperature range. In the case of Ni[sub 3]Al, the TiB[sub 2] particles dissolve and the matrix is enriched with Ti and transforms to Ni[sub 3](Al,Ti) and NiTi. If stoichiometric NiAl reinforced with TiB[sub 2] is used in a high temperature oxidizing atmosphere, then there is also a possibility that the Al may be depleted as it is oxidized. If this occurs, the composition of the matrix may shift to nickel-rich NiAl or even to Ni[sub 3]Al. This work was conducted to determine if TiB[sub 2] is used in a high temperature oxidizing atmosphere, then there is also a possibility that the Al may be depleted as it is oxidized. If this occurs, the composition of the matrix may shift to nickel-rich NiAl or even to Ni[sub 3]Al. This work was conducted to determine if TiB[sub 2] is stable in nickel-rich NiAl. The Ni-Al phase diagram is shown, and the composition of NiAl used in this study is indicated.

  2. Temperature-induced sign change of the magnetic interlayer coupling in Ni/Ni{sub 25}Mn{sub 75}/Ni trilayers on Cu{sub 3}Au(001)

    SciTech Connect (OSTI)

    Shokr, Y. A.; Zhang, B.; Sandig, O.; Kuch, W.; Erkovan, M.; Wu, C.-B.

    2015-05-07

    We investigated the magnetic interlayer coupling between two ferromagnetic (FM) Ni layers through an antiferromagnetic (AFM) Ni{sub 25}Mn{sub 75} layer and the influence of this coupling on the exchange bias phenomenon. The interlayer coupling energy of an epitaxial trilayer of 14 atomic monolayers (ML) Ni/45 ML Ni{sub 25}Mn{sub 75}/16 ML Ni on Cu{sub 3}Au(001) was extracted from minor-loop magnetization measurements using in-situ magneto-optical Kerr effect. The interlayer coupling changes from ferromagnetic to antiferromagnetic when the temperature is increased above 300?K. This sign change is interpreted as the result of the competition between an antiparallel Ruderman-Kittel-Kasuya-Yosida (RKKY)-type interlayer coupling, which dominates at high temperature, and a stronger direct exchange coupling across the AFM layer, which is present only below the Néel temperature of the AFM layer.

  3. Activity and structure of hydrotreating Ni, Mo, and Ni-Mo sulfide catalysts supported on {gamma}-Al{sub 2}O{sub 3}--USY zeolite

    SciTech Connect (OSTI)

    Li, D.; Nishijima, A.; Morris, D.E.; Guthrie, G.D.

    1999-11-15

    The catalytic hydrocracking (HC) of diphenylmethane (DPM) and hydrodesulfurization (HDS) of dibenzothiophene (DBT) over Ni, Mo, and Ni-Mo sulfide catalysts supported on a mixed ultrastable Y (USY) zeolite and gamma-Al{sub 2}O{sub 3} were studied. The catalysts were characterized using NH{sub 3} temperature-programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS), UV-Vis-NIR diffuse reflectance spectroscopy (DRS), high-resolution transmission electron microscopy (HRTEM), and chemical composition analysis. Because addition of zeolite to a conventional alumina support improves acidity, Ni, Mo, and Ni-Mo catalysts supported on the combined supports had much higher HC activity. Ni was found to be uniformly distributed throughout the catalysts; however, Mo preferentially entered the structure of {gamma}-Al{sub 2}O{sub 3} or was accommodated as oxide aggregates on {gamma}-Al{sub 2}O{sub 3}, rather than associating with zeolite. Ni and Mo catalysts supported on {gamma}-Al{sub 2}O{sub 3}-USY zeolite were good HDS catalysts and showed a shallow maximum in catalytic activity at a NiO and MoO{sub 3} content of 5 mol%. The higher activity at this content occurred because Ni or Mo species had higher surface concentrations, higher dispersion, and were more easily sulfided. Ni-Mo catalysts supported on {gamma}-Al{sub 2}O{sub 3}-USY zeolite had high HDS activity, which showed a prominent maximum at a NiO/(NiO + MoO{sub 3}) ratio of about 0.4, because at this ratio the surface species of Ni and Mo were well dispersed and more easily sulfided to form a Ni-Mo-S phase responsible for the high HDS activity. The Ni-Mo catalysts supported on gamma-Al{sub 2}O{sub 3}-USY zeolite have slightly higher HDS activity than {gamma}-Al{sub 2}O{sub 3}-USY zeolite have slightly higher HDS activity than {gamma}-Al{sub 2}O{sub 3}-supported Ni-Mo catalysts.

  4. Architectural-Level Risk Analysis Using UMLy g

    E-Print Network [OSTI]

    Bae, Doo-Hwan

    6/12/2010 1 Architectural-Level Risk Analysis Using UMLy g IEEE Transactions on Software Introduction Background Risk analysis methodology Conclusion Discussion KAIST SE LAB 2010 2/27 #12;6/12/2010 2 at the architecture level is more beneficial than assessment at later development phases Risk analysis methodology

  5. UM Design Deliverables Page 1 of 11 UNIVERSITY OF MICHIGAN

    E-Print Network [OSTI]

    Kamat, Vineet R.

    -M or the Construction Manager as backgrounds for special construction bid packs (e.g. telephone/data and audio) 19. If multiple bid packages, clear indication of scope of each release 20. Identification/visual wiring bid packs) #12;UM Design De

  6. ''Bare'' single-particle energies in Ni-56 

    E-Print Network [OSTI]

    Trache, L.; Kolomiets, A.; Shlomo, S.; Heyde, K.; Dejbakhsh, H.; Gagliardi, Carl A.; Tribble, Robert E.; Zhou, XG; Jacob, VE; Oros, AM.

    1996-01-01

    of 57Ni and 57Cu that the lowest orbital in the N53 shell is 2p3/2 @1#. The first and second excited states in 57Ni at E*50.768 MeV, Jp55/22 and E*51.113 MeV, Jp51/22 have good single-particle character @2# and corre- spond to the next two orbitals.... A quick look higher into the energy spectrum shows a group of three levels of negative parity and spins Jp55/22, 7/22, and 3/22 around the energy of the first excited state in the core at E(211)52701 keV with half-lives T1/25 31, 47, and 12 fs...

  7. Auxiliary Ligand-Dependent Assembly of Several Ni/Ni-Cd Compounds with N2O2 Donor Tetradentate Symmetrical Schiff Base Ligand

    SciTech Connect (OSTI)

    Ge, Ying Ying; Li, Guo-Bi; Fang, Hua-Cai; Zhan, Xu Lin; Gu, Zhi-Gang; Chen, Jin Hao; Sun, Feng; Cai, Yue-Peng; Thallapally, Praveen K.

    2010-09-18

    Several low-dimensional Ni/Ni-Cd complexes containing N2O2 donor tetradentate symmetrical Schiff base ligand bis(acetylacetone)ethylene-diamine (sy-H2L2), namely, [Ni(sy-L2)]2?HLa?ClO4 (2), (HLa)2?(ClO4)?(NO3) (3), [Ni(sy-L2)X]2](4,4’-bipy) (where La = 5,7-dimethyl-3,6-dihydro-2H-1,4-diazepine, X = ClO4 (4), X=NO3 (5), [Ni(sy-L2)Cd(SCN)2]n (6) and [Ni(sy-L2)?Cd(N3)2]n (7) have been synthesized from [Ni(sy-L2)]2?H2O (1). Complex 2, is three component discrete assembly generated from (HLa)+ moiety bridged with [Ni(sy-L2)] unit and ClO4- anion. A solution containing complex 2 and Cd(NO3)2 results in a mixture of 1 and 3. Further re-crystallization of 1 and 3 with various auxiliary ligands, provides coordination complexes 4 – 7 stabilized by weak hydrogen bonds in which 6 and 7 represent the first 1D heteronuclear complexes based on symmetric acacen-base Schiff base ligand.

  8. Magnetic field-induced phase transformation and variant reorientation in Ni2MnGa and NiMnCoIn magnetic shape memory alloys 

    E-Print Network [OSTI]

    Karaca, Haluk Ersin

    2009-05-15

    The purpose of this work is to reveal the governing mechanisms responsible for the magnetic field-induced i) martensite reorientation in Ni2MnGa single crystals, ii) stress-assisted phase transformation in Ni2MnGa single ...

  9. Effects of thermo-mechanical treatment on the shape memory behavior of NiTi and CoNiAl alloys 

    E-Print Network [OSTI]

    Karaca, Haluk Ersin

    2004-09-30

    Nickel-Titanium (NiTi) shape memory alloys have been the focus of extensive research due to its unique characteristics such as high recoverable strain and ductility. However, solutionized samples of NiTi do not demonstrate good shape memory...

  10. Ni(OH){sub 2} nanoflakes electrodeposited on Ni foam-supported vertically oriented graphene nanosheets for application in asymmetric supercapacitors

    SciTech Connect (OSTI)

    Wang, Xin; Liu, Jiyue; Wang, Yayu; Zhao, Cuimei; Zheng, Weitao

    2014-04-01

    Highlights: • Ni(OH){sub 2}/vertically oriented graphene nanosheets (V-GNs) was prepared. • Ni(OH){sub 2}/V-GNs had enhanced specific capacitance, cycling reversibility and stability. • Performance of Ni(OH){sub 2}/GNs/NF-AC asymmetric supercapacitor was studied. - Abstract: Binderless Ni(OH){sub 2} nanoflakes grown on Ni foam (NF)-supported vertically oriented graphene nanosheets (V-GNs) has been fabricated as a positive electrode material for asymmetric supercapacitor (ASC), coupled with activated carbon (AC) as a counter electrode material. The introduction of V-GNs leads to dense growth of nanocrystalline ?-Ni(OH){sub 2} that is confirmed by X-ray diffraction, transmission electron microscopic and scanning electron microscopic analyses. The electrochemical performances of the Ni(OH){sub 2}/GNs/NF electrode are characterized by cyclic voltammetry and charge–discharge tests, which exhibit high specific capacitance of 2215 F g{sup ?1} at a scan current density of 2.3 A g{sup ?1}, enhanced cycling stability and high rate capability. The Ni(OH){sub 2}/GNs/NF-AC-based ASC can achieve a cell voltage of 1.4 V and a specific energy density of 11.11 Wh kg{sup ?1} at 0.5 mA cm{sup ?2} with a nearly 100% coulombic efficiency at room temperature.

  11. Sources of stress gradients in electrodeposited Ni MEMS.

    SciTech Connect (OSTI)

    Hearne, Sean Joseph; Floro, Jerrold Anthony; Dyck, Christopher William

    2004-06-01

    The ability of future integrated metal-semiconductor micro-systems such as RF MEMS to perform highly complex functions will depend on developing freestanding metal structures that offer improved conductivity and reflectivity over polysilicon structures. For example, metal-based RF MEMS technology could replace the bulky RF system presently used in communications, navigation, and avionics systems. However, stress gradients that induce warpage of active components have prevented the implementation of this technology. Figure 1, is an interference micrograph image of a series of cantilever beams fabricated from electrodeposited Ni. The curvature in the beams was the result of stress gradients intrinsic to the electrodeposition process. To study the sources of the stress in electrodeposition of Ni we have incorporated a wafer curvature based stress sensor, the multibeam optical stress sensor, into an electrodeposition cell. We have determined that there are two regions of stress induced by electrodepositing Ni from a sulfamate-based bath (Fig 2). The stress evolution during the first region, 0-1000{angstrom}, was determined to be dependent only on the substrate material (Au vs. Cu), whereas the stress evolution during the second region, >1000{angstrom}, was highly dependent on the deposition conditions. In this region, the stress varied from +0.5 GPa to -0.5GPa, depending solely on the deposition rate. We examined four likely sources for the compressive intrinsic stress, i.e. reduction in tensile stress, and determined that only the adatom diffusion into grain boundaries model of Sheldon, et al. could account for the observed compressive stress. In the presentation, we shall discuss the compressive stress generation mechanisms considered and the ramifications of these results on fabrication of electrodeposited Ni for MEMS applications.

  12. Precipitation in 18 wt% Ni maraging steel of grade 350

    SciTech Connect (OSTI)

    Tewari, R.; Mazumder, S.; Batra, I.S.; Dey, G.K.; Banerjee, S.

    2000-03-14

    The evolution of precipitates in maraging steel of grade 350 was studied using the complementary techniques of small angle X-ray scattering (SACS) and transmission electron microscopy (TEM). These investigations revealed that ageing the steel at 703 K involved a rhombohedral distortion of the supersaturated b.c.c. martensite accompanied by the appearance of diffuse {omega}-like structures. This was followed by the appearance of well-defined {omega} particles containing chemical order. At the ageing temperature of 783 K, Ni{sub 3}(Ti,Mo) precipitates were the first to appear with a growth exponent of 1/3. The values of the Pored exponent obtained from the SAXS profiles indicated that the {omega} particles, formed below 723 K, had diffuse interfaces up to an ageing time of 48 h. On the other hand, Ni{sub 3}(Ti,Mo) precipitates, formed above 723 K, developed sharp interfaces in just about an hour. Also, the steel exhibited scaling in phase separation both at 703 and 783 K, but only during the early stages. Through this study it was established that at temperatures of ageing less than 723 K, evolution of {omega} particles takes place through the collapse of the unstable b.c.c. lattice and, at temperatures above 723 K, precipitation of A{sub 3}B type of phases through the mechanism of clustering and ordering of atomic species. Sharp interfaces develop rather quickly when the mechanism of precipitation involves development and amplification of a concentration wave along as in the nucleation of Ni{sub 3}(Ti,Mo) at 783 K than when an interplay of both the displacement and concentration waves is required as in the evolution of {omega} at 703 K. These results indicate towards the possibility of existence of two separate time-temperature-transformation (TTT) curves, one for the evolution of {omega}-phase and another for nucleation and growth of Ni{sub 3}(Ti,Mo).

  13. Facile approach to prepare hollow core–shell NiO microspherers for supercapacitor electrodes

    SciTech Connect (OSTI)

    Han, Dandan; Xu, Pengcheng; Jing, Xiaoyan; Wang, Jun; Song, Dalei; Liu, Jingyuan; Zhang, Milin

    2013-07-15

    A facile lamellar template method (see image) has been developed for the preparation of uniform hollow core–shell structure NiO (HCS–NiO) with a nanoarchitectured wall structure. The prepared NiO was found to be highly crystalline in uniform microstructures with high specific surface area and pore volume. The results indicated that ethanol interacted with trisodium citrate played an important role for the formation of hollow core–shell spheres. On the basis of the analysis of the composition and the morphology, a possible formation mechanism was investigated. NiO microspheres with hollow core–shell showed excellent capacitive properties. The exceptional cyclic, structural and electrochemical stability with ?95% coulombic efficiency, and very low ESR value from impedance measurements promised good utility value of hollow core–shell NiO material in fabricating a wide range of high-performance electrochemical supercapacitors. - The hollow core–shell NiO was prepared with a facile lamellar template method. The prepared NiO show higher capacitance, lower ion diffusion resistance and better electroactive surface utilization for Faradaic reactions. - Highlights: • Formation of hollow core–shell NiO via a novel and facile precipitation route. • Exhibited uniform feature sizes and high surface area of hollow core–shell NiO. • Synthesized NiO has high specific capacitance ( 448 F g{sup 1}) and very low ESR value. • Increased 20% of long life cycles capability after 500 charge–discharge cycles.

  14. Present status of the KADoNiS database

    E-Print Network [OSTI]

    I. Dillmann; R. Plag; M. Heil; F. Käppeler; T. Rauscher

    2008-06-12

    The "Karlsruhe Astrophysical Database of Nucleosynthesis in Stars" (KADoNiS) project is an online database for experimental cross sections relevant to the $s$ process and $p$ process. It is available under \\http://nuclear-astrophysics.fzk.de/kadonis and consists of two parts. Part 1 is an updated sequel to the well-known Bao et al. compilations from 1987 and 2000, which is online since April 2005. An extension of this $s$-process database to $(n,p)$ and $(n,\\alpha)$ cross sections at $kT$= 30 keV, as in the first version of the Bao compilation, is planned. The second part of KADoNiS is a $p$-process library, which includes all available experimental data from $(p,\\gamma)$, $(p,n)$, $(\\alpha,\\gamma)$, $(\\alpha,n)$, $(\\alpha,\\alpha)$, $(n,\\alpha)$ and $(\\gamma,n)$ reactions in or close to the respective Gamow window. Despite the great number of reactions required for a $p$-process reaction network, experimental data is still scarce and up to now restricted to stable targets. Given here is a short overview about the present status of the KADoNiS database.

  15. Low temperature spin dynamics in Cr{sub 7}Ni-Cu-Cr{sub 7}Ni coupled molecular rings

    SciTech Connect (OSTI)

    Bordonali, L.; Furukawa, Y.; Mariani, M.; Sabareesh, K. P. V.; Garlatti, E.; Borsa, F.

    2014-05-07

    Proton Nuclear Magnetic Resonance (NMR) relaxation measurements have been performed down to very low temperature (50?mK) to determine the effect of coupling two Cr{sub 7}Ni molecular rings via a Cu{sup 2+} ion. No difference in the spin dynamics was found from nuclear spin lattice relaxation down to 1.5?K. At lower temperature, the {sup 1}H-NMR line broadens dramatically indicating spin freezing. From the plot of the line width vs. magnetization, it is found that the freezing temperature is higher (260?mK) in the coupled ring with respect to the single Cr{sub 7}Ni ring (140?mK)

  16. $^{62}$Ni($n,?$) and $^{63}$Ni($n,?$) cross sections measured at n_TOF/CERN

    E-Print Network [OSTI]

    C. Lederer; C. Massimi; E. Berthoumieux; N. Colonna; R. Dressler; C. Guerrero; F. Gunsing; F. Käppeler; N. Kivel; M. Pignatari; R. Reifarth; D. Schumann; A. Wallner; S. Altstadt; S. Andriamonje; J. Andrzejewski; L. Audouin; M. Barbagallo; V. Becares; F. Becvar; F. Belloni; B. Berthier; J. Billowes; V. Boccone; D. Bosnar; M. Brugger; M. Calviani; F. Calvino; D. Cano-Ott; C. Carrapico; F. Cerutti; E. Chiaveri; M. Chin; G. Cortes; M. A. Cortes-Giraldo; I. Dillmann; C. Domingo-Pardo; I. Duran; N. Dzysiuk; C. Eleftheriadis; M. Fernandez-Ordonez; A. Ferrari; K. Fraval; S. Ganesan; A. R. Garc?a; G. Giubrone; M. B. Gomez-Hornillos; I. F. Goncalves; E. Gonzalez-Romero; F. Gramegna; E. Griesmayer; P. Gurusamy; S. Harrisopulos; M. Heil; K. Ioannides; D. G. Jenkins; E. Jericha; Y. Kadi; D. Karadimos; G. Korschinek; M. Krticka; J. Kroll; C. Langer; E. Lebbos; H. Leeb; L. S. Leong; R. Losito; M. Lozano; A. Manousos; J. Marganiec; S. Marrone; T. Martinez; P. F. Mastinu; M. Mastromarco; M. Meaze; E. Mendoza; A. Mengoni; P. M. Milazzo; F. Mingrone; M. Mirea; W. Mondalaers; C. Paradela; A. Pavlik; J. Perkowski; R. Plag; A. Plompen; J. Praena; J. M. Quesada; T. Rauscher; A. Riego; F. Roman; C. Rubbia; R. Sarmento; P. Schillebeeckx; S. Schmidt; G. Tagliente; J. L. Tain; D. Tarr?o; L. Tassan-Got; A. Tsinganis; L. Tlustos; S. Valenta; G. Vannini; V. Variale; P. Vaz; A. Ventura; M. J. Vermeulen; R. Versaci; V. Vlachoudis; R. Vlastou; T. Ware; M. Weigand; C. Weiß; T. J. Wright; P. Zugec

    2014-03-19

    The cross section of the $^{62}$Ni($n,\\gamma$) 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 $^{63}$Ni($n,\\gamma$) 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.

  17. PT AND PT/NI "NEEDLE" ELETROCATALYSTS ON CARBON NANOTUBES WITH HIGH ACTIVITY FOR THE ORR

    SciTech Connect (OSTI)

    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.

  18. Structural and Mössbauer spectroscopic study of Fe-Ni alloy nanoparticles

    SciTech Connect (OSTI)

    Kumar, Asheesh; Banerjee, S. Sudarsan, V.; Meena, S. S.

    2014-04-24

    Nano-crystalline Fe-Ni alloys have been synthesized in ethylene glycol medium. Based on XRD studies it is confirmed that, in these alloys Fe atoms are incorporated at Ni site to form Ni-Fe solid solutions. Mössbauer studies have established that for alloy particles having smaller size there is significant concentration of two different types of paramagnetic Fe species and their relative concentration decreased with increase in particle size.

  19. Prompt Proton Decay and Deformed Bands in 56Ni

    SciTech Connect (OSTI)

    Johansson, E. K.; Rudolph, D.; Andersson, L. L.; Torres, D. A.; Ragnarsson, I.; Andreoiu, C.; Baktash, Cyrus; Carpenter, M. P.; Charity, R. J.; Chiara, C. J.; Ekman, J.; Fahlander, C.; Hoel, C.; Pechenaya, O. L.; Reviol, W.; du Rietz, R.; Sarantites, D. G.; Seweryniak, D.; Sobotka, L. G.; Yu, Chang-Hong; Zhu, S.

    2008-06-01

    High-spin states in the doubly magic N=Z nucleus {sup 56}Ni have been investigated with three fusion-evaporation reaction experiments. New {gamma}-ray transitions are added, and a confirmation of a previously suggested prompt proton decay from a rotational band in {sup 56}Ni into the ground state of {sup 55}Co is presented. The rotational bands in {sup 56}Ni are discussed within the framework of cranked Nilsson-Strutinsky calculations.

  20. Ductile Ni[sub 3]Al alloys as bonding agents for ceramic materials

    DOE Patents [OSTI]

    Tiegs, T.N.; McDonald, R.R.

    1990-04-24

    An improved ceramic-metal composite is described comprising a mixture of a ceramic material with a ductile intermetallic alloy, preferably Ni[sub 3]Al. 2 figs.

  1. Ductile Ni.sub.3 Al alloys as bonding agents for ceramic materials in cutting tools

    DOE Patents [OSTI]

    Tiegs, Terry N. (Lenoir City, TN); McDonald, Robert R. (Traverse City, MI)

    1991-01-01

    An improved ceramic-metal composite comprising a mixture of a ceramic material with a ductile intermetallic alloy, preferably Ni.sub.3 Al.

  2. Ductile Ni[sub 3]Al alloys as bonding agents for ceramic materials in cutting tools

    DOE Patents [OSTI]

    Tiegs, T.N.; McDonald, R.R.

    1991-05-14

    An improved ceramic-metal composite comprising a mixture of a ceramic material with a ductile intermetallic alloy, preferably Ni[sub 3]Al is disclosed. 2 figures.

  3. Neutron Scattering of CeNi at the Spallation Neutron Source at...

    Office of Scientific and Technical Information (OSTI)

    Spallation Neutron Source at Oak Ridge National Laboratory: A Preliminary Report Citation Details In-Document Search Title: Neutron Scattering of CeNi at the Spallation Neutron...

  4. Strain mediated coupling in magnetron sputtered multiferroic PZT/Ni-Mn-In/Si thin film heterostructure

    SciTech Connect (OSTI)

    Singh, Kirandeep; Kaur, Davinder, E-mail: dkaurfph@iitr.ernet.in [Functional Nanomaterials Research Lab, Department of Physics and Centre of Nanotechnology, Indian Institute of Technology Roorkee, Roorkee-247667, Uttarakhand (India); Singh, Sushil Kumar [Functional Materials Division, Solid State Physics Lab (SSPL), DRDO, Lucknow Road, Timarpur, Delhi 110054 (India)

    2014-09-21

    The strain mediated electrical and magnetic properties were investigated in PZT/Ni-Mn-In heterostructure deposited on Si (100) by dc/rf magnetron sputtering. X-ray diffraction pattern revealed that (220) orientation of Ni-Mn-In facilitate the (110) oriented tertragonal phase growth of PZT layer in PZT/Ni-Mn-In heterostructure. A distinctive peak in dielectric constant versus temperature plots around martensitic phase transformation temperature of Ni-Mn-In showed a strain mediated coupling between Ni-Mn-In and PZT layers. The ferroelectric measurement taken at different temperatures exhibits a well saturated and temperature dependent P-E loops with a highest value of P{sub sat}~55 ?C/cm² obtained during martensite-austenite transition temperature region of Ni-Mn-In. The stress induced by Ni-Mn-In layer on upper PZT film due to structural transformation from martensite to austenite resulted in temperature modulated Tunability of PZT/Ni-Mn-In heterostructure. A tunability of 42% was achieved at 290 K (structural transition region of Ni-Mn-In) in these heterostructures. I-V measurements taken at different temperatures indicated that ohmic conduction was the main conduction mechanism over a large electric field range in these heterostructures. Magnetic measurement revealed that heterostructure was ferromagnetic at room temperature with a saturation magnetization of ~123 emu/cm³. Such multiferroic heterostructures exhibits promising applications in various microelectromechanical systems.

  5. Synthesis and Magnetic Properties of Ni-Zirconia Composites I. Zhitomirsky,* M. Niewczas, and A. Petric

    E-Print Network [OSTI]

    Niewczas, Marek

    Synthesis and Magnetic Properties of Ni-Zirconia Composites I. Zhitomirsky,* M. Niewczas, and A of the composites. Key Words: Electrodeposition; Hydrolysis; Polynuclear species; Zirconia; Nickel; Composite

  6. SF6432-NI Fixed Price Contracts with the Newly Independent States...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    CORPORATION SF 6432-NI (112015) SECTION II STANDARD TERMS AND CONDITIONS FOR FIXED PRICE CONTRACTS WITH THE NEWLY INDEPENDENT STATES OF THE FORMER SOVIET UNION THE FOLLOWING...

  7. Simple route for the synthesis of supercapacitive Co-Ni mixed hydroxide thin films

    SciTech Connect (OSTI)

    Dubal, D.P.; Department of Materials Science and Engineering, Gwangju Institute of Science and Technology, 261 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 ; Jagadale, A.D.; Patil, S.V.; Lokhande, C.D.

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Novel method for deposition of Co-Ni mixed hydroxide. Black-Right-Pointing-Pointer Nanoparticle network of Co-Ni hydroxide. Black-Right-Pointing-Pointer High specific capacitance of 672 F g{sup -1}. Black-Right-Pointing-Pointer High discharge/charge rates. -- Abstract: Facile synthesis of Co-Ni mixed hydroxides films with interconnected nanoparticles networks through two step route is successfully established. These films have been characterized by X-ray diffraction (XRD), Fourier transform infrared technique (FTIR), scanning electron microscopy (SEM) and wettability test. Co-Ni film formation is confirmed from XRD and FTIR study. SEM shows that the surface of Co-Ni films is composed of interconnected nanoparticles. Contact angle measurement revealed the hydrophilic nature of films which is feasible for the supercapacitor. The electrochemical performance of the film is evaluated by cyclic voltammetry, and constant-current charge/discharge cycling techniques. Specific capacitance of the Co-Ni mixed hydroxide electrode achieved 672 F g{sup -1}. Impedance analysis shows that Co-Ni mixed hydroxide electrode provides less resistance for the intercalation and de-intercalation of ions. The Co-Ni mixed electrode exhibited good charge/discharge rate at different current densities. The results demonstrated that Co-Ni mixed hydroxide composite is very promising for the next generation high performance electrochemical supercapacitors.

  8. Superior performance of Ni–W–Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; Johnson-Peck, Aaron C.; Zhao, Fuzhen; Michorczyk, Piotr; Kubacka, Anna; Stach, Eric A.; Fernández-García, Marcos; Senanayake, Sanjaya D.; et al

    2014-11-26

    In this study, the ethanol steam reforming (ESR) reaction was examined over a series of Ni-W-Ce oxide catalysts. The structures of the catalysts were characterized using in-situ techniques including X-ray diffraction, Pair Distribution Function, X-ray absorption fine structure and transmission electron microscopy; while possible surface intermediates for the ESR reaction were investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. In these materials, all the W and part of the Ni were incorporated into the CeO? lattice, with the remaining Ni forming highly dispersed nano NiO (more »under ESR conditions. The Ni-W-Ce systeme exhibited a much larger lattice strain than those seen for Ni-Ce and W-Ce. Synergistic effects between Ni and W inside ceria produced a substantial amount of defects and O vacancies that led to high catalytic activity, selectivity and stability (i.e. resistance to coke formation) during ethanol steam reforming.« less

  9. Effect of the accumulation of excess Ni atoms in the crystal structure of the intermetallic semiconductor n-ZrNiSn

    SciTech Connect (OSTI)

    Romaka, V. A.; Rogl, P.; Romaka, V. V.; Stadnyk, Yu. V.; Hlil, E. K.; Krajovskii, V. Ya.; Horyn, A. M.

    2013-07-15

    The crystal structure, electron density distribution, and energy, kinetic, and magnetic properties of the n-ZrNiSn intermetallic semiconductor heavily doped with a Ni impurity are investigated. The effect of the accumulation of an excess number of Ni{sub 1+x} atoms in tetrahedral interstices of the crystal structure of the semiconductor is found and the donor nature of such structural defects that change the properties of the semiconductor is established. The results obtained are discussed within the Shklovskii-Efros model of a heavily doped and strongly compensated semiconductor.

  10. Improved oxidation sulfidation resistance of Fe-Cr-Ni alloys

    DOE Patents [OSTI]

    Natesan, K.; Baxter, D.J.

    1983-07-26

    High temperature resistance of Fe-Cr-Ni alloy compositions to oxidative and/or sulfidative conditions is provided by the incorporation of about 1 to 8 wt % of Zr or Nb and results in a two-phase composition having an alloy matrix as the first phase and a fine grained intermetallic composition as the second phase. The presence and location of the intermetallic composition between grains of the matrix provides mechanical strength, enhanced surface scale adhesion, and resistance to corrosive attack between grains of the alloy matrix at temperatures of 500 to 1000/sup 0/C.

  11. Oxidation sulfidation resistance of Fe-Cr-Ni alloys

    DOE Patents [OSTI]

    Natesan, Ken (Naperville, IL); Baxter, David J. (Woodridge, IL)

    1984-01-01

    High temperature resistance of Fe-Cr-Ni alloy compositions to oxidative and/or sulfidative conditions is provided by the incorporation of about 1-8 wt. % of Zr or Nb and results in a two-phase composition having an alloy matrix as the first phase and a fine grained intermetallic composition as the second phase. The presence and location of the intermetallic composition between grains of the matrix provides mechanical strength, enhanced surface scale adhesion, and resistance to corrosive attack between grains of the alloy matrix at temperatures of 500.degree.-1000.degree. C.

  12. Stable atomic structure of NiTi austenite

    SciTech Connect (OSTI)

    Zarkevich, Nikolai A [Ames Laboratory; Johnson, Duane D [Ames Laboratory

    2014-08-01

    Nitinol (NiTi), the most widely used shape-memory alloy, exhibits an austenite phase that has yet to be identified. The usually assumed austenitic structure is cubic B2, which has imaginary phonon modes, hence it is unstable. We suggest a stable austenitic structure that “on average” has B2 symmetry (observed by x-ray and neutron diffraction), but it exhibits finite atomic displacements from the ideal B2 sites. The proposed structure has a phonon spectrum that agrees with that from neutron scattering, has diffraction spectra in agreement with x-ray diffraction, and has an energy relative to the ground state that agrees with calorimetry data.

  13. An analysis of the x-ray linear dichroism spectrum for NiO thin films grown on vicinal Ag(001)

    E-Print Network [OSTI]

    Wu, Y.Z.

    2008-01-01

    dichroism spectrum for NiO thin films grown on vicinal Ag(Antiferromagnetic (AFM) NiO thin films are grown epitaxiallyXLD). We find that the NiO AFM spin exhibits an in- plane

  14. UM Computer Science 2014-2015 Parent/Guardian Consent & Contact Form

    E-Print Network [OSTI]

    Chu, Xi

    UM Computer Science 2014-2015 Parent/Guardian Consent & Contact Form Print Child's Name: __________ I/we give our son/daughter permission to participate in the UM Computer Science workshop to the provision of any necessary emergency treatment to my son/daughter during the program by UM Computer Science

  15. Deformations and magnetic rotations in the {sup 60}Ni nucleus

    SciTech Connect (OSTI)

    Torres, D. A.; Cristancho, F.; Andersson, L.-L.; Johansson, E. K.; Rudolph, D.; Fahlander, C.; Ekman, J.; Rietz, R. du; Andreoiu, C.; Carpenter, M. P.; Seweryniak, D.; Zhu, S.; Charity, R. J.; Chiara, C. J.; Hoel, C.; Pechenaya, O. L.; Reviol, W.; Sarantites, D. G.; Sobotka, L. G.; Baktash, C.

    2008-11-15

    Data from three experiments using the heavy-ion fusion evaporation-reaction {sup 36}Ar+{sup 28}Si have been combined to study high-spin states in the residual nucleus {sup 60}Ni, which is populated via the evaporation of four protons from the compound nucleus {sup 64}Ge. The GAMMASPHERE array was used for all the experiments in conjunction with a 4{pi} charged-particle detector arrays (MICROBALL, LUWUSIA) and neutron detectors (NEUTRON SHELL) to allow for the detection of {gamma} rays in coincidence with the evaporated particles. An extended {sup 60}Ni level scheme is presented, comprising more than 270{gamma}-ray transitions and 110 excited states. Their spins and parities have been assigned via directional correlations of {gamma} rays emitted from oriented states. Spherical shell-model calculations in the fp-shell characterize some of the low-spin states, while the experimental results of the rotational bands are analyzed with configuration-dependent cranked Nilsson-Strutinsky calculations.

  16. Fabrication of NiTi shape memory alloy from elemental powders by hot isostatic pressing 

    E-Print Network [OSTI]

    McNeese, Matthew Doyle

    1997-01-01

    .0 and 50.6at.% Ni, packed and sealed into stainless steel containers, hot isostatically pressed (HIPed) at 20OMPa and 900-1050 'C, and machined to expose a gauge section of consolidated NiTi material for thennomechanical testing. Some samples of material...

  17. COMPARATIVE LIFE CYCLE ASSESSMENT OF ALCALINE CELLS AND NI-MH RECHARGEABLE BATTERIES

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Page 1 COMPARATIVE LIFE CYCLE ASSESSMENT OF ALCALINE CELLS AND NI-MH RECHARGEABLE BATTERIES Jean by applying the LCA methodology to evaluate the environmental footprint of alkaline cells and Ni-MH batteries phase. Besides, the emphasis on rechargeable batteries is only justified from an environmental point

  18. Nanoscale compositional analysis of NiTi shape memory alloy films deposited by DC magnetron sputtering

    SciTech Connect (OSTI)

    Sharma, S. K.; Mohan, S.; Bysakh, S.; Kumar, A.; Kamat, S. V.

    2013-11-15

    The formation of surface oxide layer as well as compositional changes along the thickness for NiTi shape memory alloy thin films deposited by direct current magnetron sputtering at substrate temperature of 300 °C in the as-deposited condition as well as in the postannealed (at 600 °C) condition have been thoroughly studied by using secondary ion mass spectroscopy, x-ray photoelectron spectroscopy, and scanning transmission electron microscopy-energy dispersive x-ray spectroscopy techniques. Formation of titanium oxide (predominantly titanium dioxide) layer was observed in both as-deposited and postannealed NiTi films, although the oxide layer was much thinner (8 nm) in as-deposited condition. The depletion of Ti and enrichment of Ni below the oxide layer in postannealed films also resulted in the formation of a graded microstructure consisting of titanium oxide, Ni{sub 3}Ti, and B2 NiTi. A uniform composition of B2 NiTi was obtained in the postannealed film only below a depth of 200–250 nm from the surface. Postannealed film also exhibited formation of a ternary silicide (Ni{sub x}Ti{sub y}Si) at the film–substrate interface, whereas no silicide was seen in the as-deposited film. The formation of silicide also caused a depletion of Ni in the film in a region ?250–300 nm just above the film substrate interface.

  19. Method For Making Electronic Circuits Having Nial And Ni3al Substrates

    DOE Patents [OSTI]

    Deevi, Seetharama C. (Midlothian, VA); Sikka, Vinod K. (Oak Ridge, TN)

    2001-01-30

    A method for making electronic circuit component having improved mechanical properties and thermal conductivity comprises steps of providing NiAl and/or Ni.sub.3 Al, and forming an alumina layer thereupon prior to applying the conductive elements. Additional layers of copper-aluminum alloy or copper further improve mechanical strength and thermal conductivity.

  20. Dehydrogenation of Propane to Propylene over Supported Model NiAu Catalysts

    E-Print Network [OSTI]

    Goodman, Wayne

    Dehydrogenation of Propane to Propylene over Supported Model Ni­Au Catalysts Zhen Yan · Yunxi Yao 2012 Ó Springer Science+Business Media, LLC 2012 Abstract Hydrogenolysis and dehydrogenation of propane. For the conversionofpropane in the presence of hydrogen, the dehydrogenation of propane to propylene was observed onthe Ni

  1. Evolution of Graphene Growth on Ni and Cu by Carbon Isotope Labeling

    E-Print Network [OSTI]

    and acceptance by the semiconductor industry, Ni and Cu have received the most attention as a graphene substrateEvolution of Graphene Growth on Ni and Cu by Carbon Isotope Labeling Xuesong Li, Weiwei Cai, Luigi Instruments Incorporated, Dallas, Texas 75243 Received August 3, 2009 ABSTRACT Large-area graphene growth

  2. A Linear Combination Analyses Approach For Directly Speciating Ni Contaminated Soils.

    E-Print Network [OSTI]

    Sparks, Donald L.

    A Linear Combination Analyses Approach For Directly Speciating Ni Contaminated Soils. (S02-trivedi215458-Oral) Abstract: To provide an accurate description of the fate of Ni in aerial- contaminated soils to combine multiple analytical techniques to accurately determine metal speciation in complex soil systems

  3. Finite Element Based Micromechanical Analysis of Precipitated NiTi Shape Memory Alloys 

    E-Print Network [OSTI]

    Cox, Austin Edward

    2015-07-22

    into the material and its thermomechanical response than ever before. The most widely modeled and produced SMA class in industry today is one which hosts Ni as a core component of its composition, and usually takes the form of NiTi. When these SMA materials are heat...

  4. Ni-dispersed fullerenes: Hydrogen storage and desorption properties Weon Ho Shin and Seong Ho Yang

    E-Print Network [OSTI]

    Goddard III, William A.

    Ni-dispersed fullerenes: Hydrogen storage and desorption properties Weon Ho Shin and Seong Ho Yang could be viable alternatives to reversible hydrogen storage. It is demonstrated that a single Ni coated-dispersed fullerenes are considered to be the novel hydrogen storage media capable of storing 6.8 wt % H2, thus

  5. Biomaterials 24 (2003) 39313939 Corrosion and wear-corrosion behavior of NiTi modified

    E-Print Network [OSTI]

    Crone, Wendy C.

    2003-01-01

    Biomaterials 24 (2003) 3931­3939 Corrosion and wear-corrosion behavior of NiTi modified by plasma, aerospace, and automotive industries. NiTi alloys are important materials for biomedical and dental devices. The alloy has been used for making orthodontic dental arch wires and medical guide wires for diagnostic

  6. Effect of Mo Addition on Structure and Magnetocaloric Effect in c-FeNi Nanocrystals

    E-Print Network [OSTI]

    Laughlin, David E.

    - tion metals have been investigated to replace rare- earth metals for cost reduction. Researchers have comparable to those of rare-earth metals. Recently, Fe-Ni alloys were suggested as economical alterna- tives3 refrigerants without critical rare-earth materials. Key words: Nanostructured FeNi, magnetocaloric effect

  7. Superelastic and cyclic response of NiTi SMA at various strain rates and temperatures

    E-Print Network [OSTI]

    Nemat-Nasser, Sia

    in the range of 77­400 K. The influence of the annealing temperature on the fatigue response is also examined of NiTi SMAs depend on the annealing temperature; (2) in cyclic loading, the dissipated energy over loading rates, NiTi SMAs show properties similar to ordinary steels, as has been established by the first

  8. Formation and Stability of Ni-Al Hydroxide Phases in Soils

    E-Print Network [OSTI]

    Sparks, Donald L.

    surface precipitate phases on kaolinite surfaces as the humic acid content of the system was increased. At 1% humic acid by weight, mixed Ni-Al hydroxide precipitates formed on the kaolinite surface after 4 days. At 5 wt % humic acid, however, precipitate formation was slower and resulted in Ni(OH)2

  9. Bilayer thickness effects on nanoindentation behavior of Ag/Ni multilayers

    E-Print Network [OSTI]

    Hong, Soon Hyung

    by nanoindentation hardness and creep tests. The hardness increased with decreasing bilayer thickness, although of nanoindentation creep tests on Ag/Ni nanomultilayers with various bilayer thicknesses. Multilayered Ag/Ni films thickness. A nanoindentation creep test was used to study the creep behavior of nano- scale multilayers

  10. THREE-DIMENSIONAL ATOMIC STRUCTURE OF NiO ZrO2(CUBIC) INTERFACES

    E-Print Network [OSTI]

    Pennycook, Steve

    THREE-DIMENSIONAL ATOMIC STRUCTURE OF NiO± ZrO2(CUBIC) INTERFACES E. C. DICKEY{1 , V. P. DRAVID1-dimensional atomic structure of low-energy NiO±ZrO2(cubic) interfaces is determined through a combination of electron the structural and chemical aspects of the interface and associ- ated interfacial relaxation mechaubic) interface

  11. Ferromagnetic interactions and martensitic transformation in Fe doped Ni-Mn-In shape memory alloys

    SciTech Connect (OSTI)

    Lobo, D. N.; Priolkar, K. R.; Emura, S.; Nigam, A. K.

    2014-11-14

    The structure, magnetic, and martensitic properties of Fe doped Ni-Mn-In magnetic shape memory alloys have been studied by differential scanning calorimetry, magnetization, resistivity, X-ray diffraction (XRD), and EXAFS. While Ni{sub 2}MnIn{sub 1?x}Fe{sub x} (0???x???0.6) alloys are ferromagnetic and non martensitic, the martensitic transformation temperature in Ni{sub 2}Mn{sub 1.5}In{sub 1?y}Fe{sub y} and Ni{sub 2}Mn{sub 1.6}In{sub 1?y}Fe{sub y} increases for lower Fe concentrations (y???0.05) before decreasing sharply for higher Fe concentrations. XRD analysis reveals presence of cubic and tetragonal structural phases in Ni{sub 2}MnIn{sub 1?x}Fe{sub x} at room temperature with tetragonal phase content increasing with Fe doping. Even though the local structure around Mn and Ni in these Fe doped alloys is similar to martensitic Mn rich Ni-Mn-In alloys, presence of ferromagnetic interactions and structural disorder induced by Fe affect Mn-Ni-Mn antiferromagnetic interactions resulting in suppression of martensitic transformation in these Fe doped alloys.

  12. The Influence of Ni-Coated TiC on Laser-Deposited IN625 Metal Matrix Composites

    E-Print Network [OSTI]

    2010-01-01

    The In?uence of Ni-Coated TiC on Laser-Deposited IN625 Metalwith Ni-coated and uncoated TiC reinforcement particles toand spatial distribution of TiC particles in the deposited

  13. Direct synthesis of porous NiO nanowall arrays on conductive substrates for supercapacitor application

    SciTech Connect (OSTI)

    Zhu, Jianhui; Jiang, Jian; Liu, Jingping; Ding, Ruimin; Ding, Hao; Feng, Yamin; Wei, Guangming; Huang, Xintang

    2011-03-15

    Porous NiO nanowall arrays (NWAs) grown on flexible Fe-Co-Ni alloy have been successfully synthesized by using nullaginite (Ni{sub 2}(OH){sub 2}CO{sub 3}) as precursor and investigated as supercapacitor electrodes. In details, we adopted a simple hydrothermal method to realize Ni{sub 2}(OH){sub 2}CO{sub 3} NWAs and examined their robust mechanical adhesion to substrate via a long-time ultrasonication test. Porous NiO NWAs were then obtained by a post-calcination towards precursors at 500 {sup o}C in nitrogen atmosphere. Electrochemical properties of as-synthesized NiO NWAs were evaluated by cyclic voltammetry and galvanostatic charge/discharge; porous NiO NWAs electrode delivered a specific capacitance of 270 F/g (0.67 A/g); even at high current densities, the electrode could still deliver a high capacitance up to 236 F/g (13.35 A/g). Meanwhile, it exhibited excellent cycle lifetime with {approx}93% specific capacitance kept after 4000 cycles. These results suggest that as-made porous NiO NWAs electrode is a promising candidate for future thin-film supercapacitors and other microelectronic systems. -- Graphical abstract: Porous NiO nanowall arrays (NWAs) grown on alloy substrate have been made using nullaginite as precursor and studied as supercapacitor electrodes. Porous nanowalls interconnected with each other resulting in the formation of extended-network architectures and exhibited excellent capacitor properties. NiO NWAs electrode delivered a capacitance of 270 F/g (0.67 A/g); even at high current density, the electrode could still deliver a high capacitance up to 236 F/g (13.35 A/g). Besides, it exhibited excellent cycle lifetime with {approx}93% capacitance kept after 4000 cycles. These remarkable results made it possible for mass production of NiO NWAs and future thin-film microelectronic applications. Display Omitted Research highlights: {yields} Large-scale nullaginite (Ni{sub 2}(OH){sub 2}CO{sub 3}) nanowall arrays (NWAs) have been synthesized on flexible alloy substrate by a facile hydrothermal method. {yields} Ultrasonication test has been conducted to demonstrate the robust mechanical adhesion between NWAs and substrate. {yields} As supercapacitor electrodes porous NiO NWAs obtained by a post-calcination towards Ni{sub 2}(OH){sub 2}CO{sub 3} precursors have exhibited excellent electrochemical properties.

  14. Understanding and engineering of NiGe/Ge junction formed by phosphorus ion implantation after germanidation

    SciTech Connect (OSTI)

    Oka, Hiroshi, E-mail: oka@asf.mls.eng.osaka-u.ac.jp; Minoura, Yuya; Hosoi, Takuji; Shimura, Takayoshi; Watanabe, Heiji [Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2014-08-11

    Modulation of the effective electron Schottky barrier height (eSBH) of NiGe/Ge contacts induced by phosphorus ion implantation after germanide formation was investigated by considering local inhomogeneity in the eSBH. Systematic studies of NiGe/Ge contact devices having various germanide thicknesses and ion implantation areas indicated the threshold dopant concentration at the NiGe/Ge interface required for eSBH modulation and negligible dopant diffusion even at NiGe/Ge interface during drive-in annealing, leading to variation in the eSBH between the bottom and sidewall portions of the NiGe regions. Consequently, this method makes it possible to design source/drain contacts with low-resistivity Ohmic and ideal rectifying characteristics for future Ge-based transistors.

  15. Thermal plasma synthesis of Fe{sub 1?x}Ni{sub x} alloy nanoparticles

    SciTech Connect (OSTI)

    Raut, Suyog A.; Kanhe, Nilesh S.; Bhoraskar, S. V.; Mathe, V. L.; Das, A. K.

    2014-04-24

    Fe-Ni alloy nanoparticles are of great interest because of diverse practical applications in the fields such as magnetic fluids, high density recording media, catalysis and medicine. We report the synthesis of Fe-Ni nanoparticles via thermal plasma route. Thermal plasma assisted synthesis is a high temperature process and gives high yields of production. Here, we have used direct arc thermal plasma plume of 6kw as a source of energy at operating pressure 500 Torr. The mixture of Fe-Ni powder in required proportion (Fe{sub 1?x}Ni{sub x}; x=0.30, 0.32, 0.34, 0.36, 0.38 and 0.40) was made to evaporate simultaneously from the graphite anode in thermal plasma reactor to form Fe-Ni bimetallic nanoparticles. The as synthesized particles were characterized by X-Ray Diffraction (XRD), Thermo-Gravimetric Analysis/Differential Scanning Calorimtry (TGA/DSC)

  16. Electrochemical sensing behaviour of Ni doped Fe{sub 3}O{sub 4} nanoparticles

    SciTech Connect (OSTI)

    Suresh, R.; Giribabu, K.; Manigandan, R.; Narayanan, V., E-mail: vnnara@yahoo.co.in [Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai 600 025 (India); Vijayalakshmi, L. [Annai Veilankanni's College for Women (Arts and Science), Saidapet, Chennai 600015 (India); Stephen, A. [Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600 025 (India)

    2014-01-28

    Ni doped Fe{sub 3}O{sub 4} nanoparticles were synthesized by simple hydrothermal method. The prepared nanomaterials were characterized by X-ray diffraction analysis, DRS-UV-Visible spectroscopy and field emission scanning electron microscopy. The XRD confirms the phase purity of the synthesized Ni doped Fe{sub 3}O{sub 4} nanoparticles. The optical property of Ni doped Fe{sub 3}O{sub 4} nanoparticles were studied by DRS UV-Visible analysis. The electrochemical sensing property of pure and Ni doped Fe{sub 3}O{sub 4} nanoparticles were examined using uric acid as an analyte. The obtained results indicated that the Ni doped Fe{sub 3}O{sub 4} nanoparticles exhibited higher electrocatalytic activity towards uric acid.

  17. Eutectic bonding of a Ti sputter coated, carbon aerogel wafer to a Ni foil

    SciTech Connect (OSTI)

    Jankowski, A.F.; Hayes, J.P.; Kanna, R.L.

    1994-06-01

    The formation of high energy density, storage devices is achievable using composite material systems. Alternate layering of carbon aerogel wafers and Ni foils with rnicroporous separators is a prospective composite for capacitor applications. An inherent problem exists to form a physical bond between Ni and the porous carbon wafer. The bonding process must be limited to temperatures less than 1000{degrees}C, at which point the aerogel begins to degrade. The advantage of a low temperature eutectic in the Ni-Ti alloy system solves this problem. Ti, a carbide former, is readily adherent as a sputter deposited thin film onto the carbon wafer. A vacuum bonding process is then used to join the Ni foil and Ti coating through eutectic phase formation. The parameters required for successfld bonding are described along with a structural characterization of the Ni foil-carbon aerogel wafer interface.

  18. Fabrication of NiO thin film electrode for supercapacitor applications

    SciTech Connect (OSTI)

    Mali, V. V.; Navale, S. T.; Chougule, M. A.; Khuspe, G. D.; Godse, P. R.; Patil, V. B., E-mail: drvbpatil@gmail.com [Functional Materials Research Laboratory, School of Physical Sciences, Solapur University, Solapur-413255 (India); Pawar, S. A. [Department of Electronics, Shri Shivaji Mahavidhyala, Barshi, Solapur-413411 (India)

    2014-04-24

    Nanocrystalline NiO electrode is successfully electrosynthesized for supercapacitor application. The nanocrystalline NiO electrode is characterized using scanning electron microscope (SEM). Nickel oxide is a highly porous and the film surface looked smooth and composed of fine elongated particles. The supercapacitive performance of NiO electrode is tested using cyclic voltammetry (C-V) technique in 0.5M Na{sub 2}S{sub 2}O{sub 3} electrolyte within potential range of ?1.2 to +1.2 V. The effect of scan rate on the capacitance of NiO electrode is studied. The highest specific capacitance of 439 Fg{sup ?1} at the voltage scan rate of 50mVs{sup ?1} is achieved. Additionally stability and charging–discharging of NiO electrode are studied.

  19. Monodisperse core/shell Ni/FePt nanoparticles and their con-version to Ni/Pt to catalyze oxygen reduction

    SciTech Connect (OSTI)

    Zhang, Sen; Su, Dong; Doan-Nguyen, Vicky V. T.; Wu, Yaoting; Li, Jing; Sun, Shouheng; Murray, Christopher B.; Hao, Yizhou

    2014-11-12

    We report a size-controllable synthesis of monodisperse core/shell Ni/FePt nanoparticles (NPs) via a seed-mediated growth and their subsequent conversion to Ni/Pt NPs. Preventing surface oxidation of the Ni seeds is essential for the growth of uniform FePt shells. These Ni/FePt NPs have a thin (? 1 nm) FePt shell, and can be converted to Ni/Pt by acetic acid wash to yield active catalysts for oxygen reduction reaction (ORR). Tuning the core size allow for optimization of their electrocatalytic activity. The specific activity and mass activity of 4.2 nm/0.8 nm core/shell Ni/FePt reach 1.95 mA/cm² and 490 mA/mgPt at 0.9 V (vs. reversible hydrogen electrode, RHE), which are much higher than those of benchmark commercial Pt catalyst (0.34 mA/cm² and 92 mA/mgPt at 0.9 V). Our studies provide a robust approach to monodisperse core/shell NPs with non-precious metal core, making it possible to develop advanced NP catalysts with ultralow Pt content for ORR and many other heterogeneous reactions.

  20. An APFIM and TEM study of Ni{sub 4}Mo precipitation in a commercial Ni-28% Mo-1.4% Fe-0.4% Cr wt. % alloy

    SciTech Connect (OSTI)

    Thomson, R.C.; Brown, N.; Bates, J.S. [Loughborough Univ. (United Kingdom). Inst. of Polymer Technology and Materials Engineering; Russell, K.F.; Miller, M.K. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

    1998-02-01

    Ni-Mo alloys containing at least 26 wt.% Mo have a negligible corrosion rate in boiling 10% hydrochloric acid and are therefore used in corrosive environments. A series of commercial Ni-Mo alloys has been developed with subtle variations in chemical composition. These alloys usually contain {approximately} 28 wt.% Mo with additions of up to 5% Fe and Cr. A significant amount of research has been performed to understand the microstructure and properties of these alloys, although most of the effort has concentrated on the Ni-Mo binary system. In some alloys with low Fe and Cr contents, a severe embrittlement problem has been observed due to the formation of the Ni{sub 4}Mo (D1{sub a}-ordered) phase within the microstructure. This research focuses on a commercial alloy with nominal composition Ni-28% Mo-1.4% Fe-0.4% Cr-0.1% Mn-0.003 wt.% C. The material supplied was a heat treatment coupon which had been attached to a large vessel during fabrication. Assessment of the chemical analysis of the alloy suggested that detrimental phases could be present or might appear during subsequent repair work. Therefore, it was important to assess the microstructural condition of the vessel, and in particular the kinetics of precipitation of Ni{sub 4}Mo.

  1. Correlating Extent of Pt–Ni Bond Formation with Low-temperature Hydrogenation of Benzene and 1,3-butadiene over Supported Pt/Ni Bimetallic Catalysts

    SciTech Connect (OSTI)

    Lonergan, W.; Vlachos, D; Chen, J

    2010-01-01

    Low-temperature hydrogenation of benzene and 1,3-butadiene on supported Pt/Ni catalysts have been used as probe reactions to correlate hydrogenation activity with the extent of Pt-Ni bimetallic bond formation. Pt/Ni bimetallic and Pt and Ni monometallic catalysts were supported on {gamma}-Al{sub 2}O{sub 3} using incipient wetness impregnation. Two sets of bimetallic catalysts were synthesized: one set to study the effect of metal atomic ratio and the other to study the effect of impregnation sequence. Fourier transform infrared spectroscopy (FTIR) CO adsorption studies were performed to characterize the surface composition of the bimetallic nanoparticles, and transmission electron microscopy (TEM) was utilized to characterize the particle size distribution. Batch reactor studies with FTIR demonstrated that all bimetallic catalysts outperformed monometallic catalysts for both benzene and 1,3-butadiene hydrogenation. Within the two sets of bimetallic catalysts, it was found that catalysts with a smaller Pt:Ni ratio possessed higher hydrogenation activity and that catalysts synthesized using co-impregnation had greater activity than sequentially impregnated catalysts. Extended X-ray absorption fine structure (EXAFS) measurements were performed in order to verify the extent of Pt-Ni bimetallic bond formation, which was found to correlate with the hydrogenation activity.

  2. Monodisperse core/shell Ni/FePt nanoparticles and their con-version to Ni/Pt to catalyze oxygen reduction

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, Sen [Univ. of Pennsylvania, Philadelphia, PA (United States); Su, Dong [Brookhaven National Lab. (BNL), Upton, NY (United States); Doan-Nguyen, Vicky V. T. [Univ. of Pennsylvania, Philadelphia, PA (United States); Wu, Yaoting [Univ. of Pennsylvania, Philadelphia, PA (United States); Li, Jing [Brookhaven National Lab. (BNL), Upton, NY (United States); Sun, Shouheng [Brown Univ., Providence, RI (United States); Murray, Christopher B. [Univ. of Pennsylvania, Philadelphia, PA (United States); Hao, Yizhou [Univ. of Pennsylvania, Philadelphia, PA (United States)

    2014-11-12

    We report a size-controllable synthesis of monodisperse core/shell Ni/FePt nanoparticles (NPs) via a seed-mediated growth and their subsequent conversion to Ni/Pt NPs. Preventing surface oxidation of the Ni seeds is essential for the growth of uniform FePt shells. These Ni/FePt NPs have a thin (? 1 nm) FePt shell, and can be converted to Ni/Pt by acetic acid wash to yield active catalysts for oxygen reduction reaction (ORR). Tuning the core size allow for optimization of their electrocatalytic activity. The specific activity and mass activity of 4.2 nm/0.8 nm core/shell Ni/FePt reach 1.95 mA/cm² and 490 mA/mgPt at 0.9 V (vs. reversible hydrogen electrode, RHE), which are much higher than those of benchmark commercial Pt catalyst (0.34 mA/cm² and 92 mA/mgPt at 0.9 V). Our studies provide a robust approach to monodisperse core/shell NPs with non-precious metal core, making it possible to develop advanced NP catalysts with ultralow Pt content for ORR and many other heterogeneous reactions.

  3. Monodisperse core/shell Ni/FePt nanoparticles and their con-version to Ni/Pt to catalyze oxygen reduction

    SciTech Connect (OSTI)

    Zhang, Sen; Hao, Yizhou; Su, Dong; Doan-Nguyen, Vicky V. T.; Wu, Yaoting; Li, Jing; Sun, Shouheng; Murray, Christopher B.

    2014-10-28

    We report a size-controllable synthesis of monodisperse core/shell Ni/FePt nanoparticles (NPs) via a seed-mediated growth and their subsequent conversion to Ni/Pt NPs. Preventing surface oxidation of the Ni seeds is essential for the growth of uniform FePt shells. These Ni/FePt NPs have a thin (? 1 nm) FePt shell, and can be converted to Ni/Pt by acetic acid wash to yield active catalysts for oxygen reduction reaction (ORR). Tuning the core size allow for optimization of their electrocatalytic activity. The specific activity and mass activity of 4.2 nm/0.8 nm core/shell Ni/FePt reach 1.95 mA/cm² and 490 mA/mgPt at 0.9 V (vs. reversible hydrogen electrode, RHE), which are much higher than those of benchmark commercial Pt catalyst (0.34 mA/cm² and 92 mA/mgPt at 0.9 V). Our studies provide a robust approach to monodisperse core/shell NPs with non-precious metal core, making it possible to develop advanced NP catalysts with ultralow Pt content for ORR and many other heterogeneous reactions.

  4. Monodisperse core/shell Ni/FePt nanoparticles and their con-version to Ni/Pt to catalyze oxygen reduction

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, Sen; Hao, Yizhou; Su, Dong; Doan-Nguyen, Vicky V. T.; Wu, Yaoting; Li, Jing; Sun, Shouheng; Murray, Christopher B.

    2014-10-28

    We report a size-controllable synthesis of monodisperse core/shell Ni/FePt nanoparticles (NPs) via a seed-mediated growth and their subsequent conversion to Ni/Pt NPs. Preventing surface oxidation of the Ni seeds is essential for the growth of uniform FePt shells. These Ni/FePt NPs have a thin (? 1 nm) FePt shell, and can be converted to Ni/Pt by acetic acid wash to yield active catalysts for oxygen reduction reaction (ORR). Tuning the core size allow for optimization of their electrocatalytic activity. The specific activity and mass activity of 4.2 nm/0.8 nm core/shell Ni/FePt reach 1.95 mA/cm² and 490 mA/mgPt at 0.9 Vmore »(vs. reversible hydrogen electrode, RHE), which are much higher than those of benchmark commercial Pt catalyst (0.34 mA/cm² and 92 mA/mgPt at 0.9 V). Our studies provide a robust approach to monodisperse core/shell NPs with non-precious metal core, making it possible to develop advanced NP catalysts with ultralow Pt content for ORR and many other heterogeneous reactions.« less

  5. Hybrid Composite Ni(OH)(2)@NiCo2O4 Grown on Carbon Fiber Paper for High-Performance Supercapacitors

    SciTech Connect (OSTI)

    Huang, L; Chen, DC; Ding, Y; Wang, ZL; Zeng, ZZ; Liu, ML

    2013-11-13

    We have successfully fabricated and tested the electrochemical performance of supercapacitor electrodes consisting of Ni(OH)(2) nanosheets coated on NiCo2O4 nanosheets grown on carbon fiber paper (CFP) current collectors. When the NiCo2O4 nanosheets are replaced by Co3O4 nanosheets, however, the energy and power density as well as the rate capability of the electrodes are significantly reduced, most likely due to the lower conductivity of Co3O4 than that of NiCo2O4. The 3D hybrid composite Ni(OH)(2)/ NiCo2O4/CFP electrodes demonstrate a high areal capacitance of 5.2 F/cm(2) at a cycling current density of 2 rnA/cm(2), with a capacitance retention of 79% as the cycling current density was increased from 2 to 50 mA/cm(2). The remarkable performance of these hybrid composite electrodes implies that supercapacitors based on them have potential for many practical applications.

  6. Resonant two-photon ionization spectroscopy of NiC Dale J. Brugh and Michael D. Morse

    E-Print Network [OSTI]

    Morse, Michael D.

    Resonant two-photon ionization spectroscopy of NiC Dale J. Brugh and Michael D. Morse University investigation of jet-cooled diatomic NiC has revealed a complex pattern of vibronic levels in the wave number as far to the blue as 26 951 cm 1 indicates that D0 NiC 3.34 eV, and the ionization energy of NiC has

  7. Influence of Mn and Ni on the microstructure and toughness of C-Mn-Ni weld metals

    SciTech Connect (OSTI)

    Zhang, Z.; Farrar, R.A. [Univ. of Southampton (United Kingdom). Dept. of Mechanical Engineering

    1997-05-01

    A systematic investigation has been carried out to study the microstructure and toughness of C-Mn-Ni low-alloy shielded metal arc (SMA) weld metals. The manganese and nickel concentrations were progressively changed to determine their influence on weld microstructure and mechanical properties as well as to identify their interactions. The results obtained showed that manganese and nickel have considerable effect on the weld metal microstructure, and both Mn and Ni affect the microstructure in a similar way, i.e., promoting acicular ferrite at the expense of proeutectoid ferrite (grain boundary ferrite and ferrite sideplates). The results in the top bead also showed that there is an optimum composition range that produces an optimum balance of weld metal microstructures. For optimum toughness, a combination of 0.6--1.4% manganese and 1.0--3.7% nickel is suggested. Additions beyond this limit promotes the formation of martensite and other microstructural features, which may be detrimental to weld metal toughness.

  8. The interfacial reaction of Ni on (100) Si?â??xGex (x=0, 0.25) and (111) Ge

    E-Print Network [OSTI]

    Jin, Lijuan

    The interfacial reaction of Ni with Si, Si?.??Ge?.??, and Ge at 400°C has been investigated. A uniform epitaxial NiSi film was obtained at 400°C for Ni-Silicidation on Si using rapid thermal annealing method. Similarly, ...

  9. Development of ZnNiCd coatings by pulse electrodeposition process Prabhu Ganesan, Swaminatha P. Kumaraguru, Branko N. Popov

    E-Print Network [OSTI]

    Popov, Branko N.

    Development of Zn­Ni­Cd coatings by pulse electrodeposition process Prabhu Ganesan, Swaminatha P indicated that Zn­Ni­Cd alloys exhibit superior barrier properties when compared to Cd or Zn­Ni coatings of corrosion resistant coating in aerospace, electrical, and fastener industries due to its excel- lent

  10. The corrosion behavior and hemocompatibility of TiNi alloys coated with DLC by plasma based ion implantation

    E-Print Network [OSTI]

    Zheng, Yufeng

    The corrosion behavior and hemocompatibility of TiNi alloys coated with DLC by plasma based ion successfully deposited on Ti­50.8 at.% Ni alloys using plasma based ion implantation (PBII) technique on the surface modification of TiNi alloys, including ion implan- tation, multi arc ion-plating as well as Ti

  11. Ni(III)/(IV) Bis(dicarbollide) as a Fast, Noncorrosive Redox Shuttle for Dye-Sensitized Solar Cells

    E-Print Network [OSTI]

    multiple redox transformations involving net charges of -2, -1, and 0, with Ni(II), Ni(III) (3), and Ni at the electrolyte interface. Previous DSC Fc/Fc+ couple work showed that dark currents can be suppressed by TiO2/Fc+ vs SCE (translating to a smaller potential difference between the dark electrode and quasi

  12. Chemically anchored NiOxcarbon composite fibers for Li-ion batteries with long cycle-life and

    E-Print Network [OSTI]

    Cao, Guozhong

    the research hot-pot of NiO based anodes for LIBs. Amorphous carbon, carbon nanotubes, graphene, and carbon enhanced properties.16,17 Carbon nanotubes were also used to prepare NiO­carbon composites via a surfaceO­gra- phene commonly began with nickel salts and graphene oxide, and the resultant NiO­graphene composites

  13. A numerical method for predicting the bending fatigue life of NiTi and stainless steel root canal

    E-Print Network [OSTI]

    Zheng, Yufeng

    A numerical method for predicting the bending fatigue life of NiTi and stainless steel root canal. A numerical method for predicting the bending fatigue life of NiTi and stainless steel root canal instruments­titanium alloy (NiTi) and stainless steel (SS) endodontic files using finite element analysis. Methodology

  14. High Temperature Oxidation Behavior of gamma-Ni+gamma'-Ni3Al Alloys and Coatings Modified with Pt and Reactive Elements

    SciTech Connect (OSTI)

    Nan Mu

    2007-12-01

    Materials for high-pressure turbine blades must be able to operate in the high-temperature gases (above 1000 C) emerging from the combustion chamber. Accordingly, the development of nickel-based superalloys has been constantly motivated by the need to have improved engine efficiency, reliability and service lifetime under the harsh conditions imposed by the turbine environment. However, the melting point of nickel (1455 C) provides a natural ceiling for the temperature capability of nickel-based superalloys. Thus, surface-engineered turbine components with modified diffusion coatings and overlay coatings are used. Theses coatings are capable of forming a compact and adherent oxide scale, which greatly impedes the further transport of reactants between the high-temperature gases and the underlying metal and thus reducing attack by the atmosphere. Typically, these coatings contain {beta}-NiAl as a principal constituent phase in order to have sufficient aluminum content to form an Al{sub 2}O{sub 3} scale at elevated temperatures. The drawbacks to the currently-used {beta}-based coatings, such as phase instabilities, associated stresses induced by such phase instabilities, and extensive coating/substrate interdiffusion, are major motivations in this study to seek next-generation coatings. The high-temperature oxidation resistance of novel Pt + Hf-modified {gamma}-Ni + {gamma}-Ni{sub 3}Al-based alloys and coatings were investigated in this study. Both early-stage and 4-days isothermal oxidation behavior of single-phase {gamma}-Ni and {gamma}{prime}-Ni{sub 3}Al alloys were assessed by examining the weight changes, oxide-scale structures, and elemental concentration profiles through the scales and subsurface alloy regions. It was found that Pt promotes Al{sub 2}O{sub 3} formation by suppressing the NiO growth on both {gamma}-Ni and {gamma}{prime}Ni{sub 3}Al single-phase alloys. This effect increases with increasing Pt content. Moreover, Pt exhibits this effect even at lower temperatures ({approx}970 C) in the very early stage of oxidation. It was also inferred that Pt enhances the diffusive flux of aluminum from the substrate to the scale/alloy interface. Relatively low levels of hafnium addition to Pt-free {gamma}{prime}-Ni{sub 3}Al increased the extent of external NiO formation due to non-protective HfO{sub 2} formation. Accordingly, this effect intensified with increasing Hf content from 0.2 to 0.5 at.%.

  15. Advertising rates for 4NI, the Directory Portal for Northern IrelandAdd to the Guestbook of 4NI, the Directory Portal for Northern IreBack to 4NI, the Directory Portal for No 24 February 2004 @ 10:33:27 AM

    E-Print Network [OSTI]

    West, Stuart

    Advertising rates for 4NI, the Directory Portal for Northern IrelandAdd to the Guestbook of 4NI, the Directory Portal for Northern IreBack to 4NI, the Directory Portal for No 24 February 2004 @ 10:33:27 AM Directory Portal For Northern Ireland Industry News 20 February 2004 Some mammals can adjust sex

  16. In situ carbonyl extraction of Ni from gaseous diffusion cells

    SciTech Connect (OSTI)

    Visnapuu, A. [USBM Salt Lake Research Center, Salt Lake City, UT (United States); Hollenberg, G.W. [Battelle Pacific Northwest Lab., Richland, WA (United States); Bundy, R.D. [Battelle Memorial Institute, Oak Ridge, TN (United States)

    1995-12-31

    This paper discusses the use of carbonyl processing technology for recovery of nickel from uranium isotope separation diffusion cells, and potential applications to recover nickel, iron, chromium, cobalt, and other carbonyl forming metals from nuclear waste while reducing the volume of the high level residue for more economic disposal. Nickel powder was carbonylated under static and dynamic conditions using only carbon monoxide to determine if the nickel powder would react rapidly enough to require no promoter. Nickel to Ni(CO){sub 4} conversion was realized in all cases and nickel metal was vapor deposited in the thermal decomposer, but the conversion rates in all cases the reaction were too slow for practical recovery. Addition of hydrogen sulfide gas as a promoter increased the conversion rate more than 500-fold over conversion with no promoter. Test summaries are provided in the paper; results indicate that promoter activated carbonylation is a viable approach for recovery of nickel from uranium isotope diffusion cells.

  17. Properties of Ni-Al under shock loading

    SciTech Connect (OSTI)

    Koskelo, A. C.; McClellan, K. J.; Brooks, J. D.; Paisley, Dennis L.; Swift, D. C.

    2002-01-01

    New models for the dynamic response of materials will be based increasingly on better understanding and representation of processes occurring at the microstructural level. These developments require advances in diagnostics and models which can be applied explicitly to microstructural response. Various phenomena occur at the microstructural level which are generally ignored or averaged out in continuum-level models. One example of such 'irregular hydrodynamics' is the roughness imparted to a shock wave as it propagates through a polycrystalline material. We have developed imaging techniques to study spatial variations in shock propagation through polycrystalline materials. In order to interpret spatially-resolved data from polycrystal samples, we need to compare with simulations which represent the microstructure. Here we describe work undertaken to develop a model of the dynamic response of individual grains. The material chosen was Ni-Al alloy, because it exhibits a relatively large degree of elastic anisotropy, and it is relatively easy to manufacture.

  18. Monopole resonance strengths in Ni-58 and Pb-208 

    E-Print Network [OSTI]

    Youngblood, David H.

    1997-01-01

    . Unfortunately, those data did not ex- tend to the small angles necessary to identify the GMR and to separate it from other multipoles. Both authors speculate of the E0 EWSR @7# are shown in Table I. Folded potentials and form factors were obtained using... and TABLE I. Parameters for folding model calculations. Nucleus c ~fm! a ~fm! ^r2& ~fm2! a02 Ex ~MeV! V ~MeV! W ~MeV! 58Ni 4.08 0.515 13.653 0.0194 17.0 35.5 21.5 208Pb 6.67 0.545 30.798 0.00297 13.7 40.5 26.0 both nuclei, with 160% of the E0...

  19. Thermomechanical behavior of 55Ni45Ti nitinol

    SciTech Connect (OSTI)

    Ford, D.S.; White, S.R. [Univ. of Illinois, Urbana, IL (United States)] [Univ. of Illinois, Urbana, IL (United States)

    1996-06-01

    Extensive and full range mechanical testing of 55Ni45Ti nitinol alloy wire up to failure over a wide range of testing temperatures is reported. Thermomechanical properties are obtained including: initial modulus, secondary modulus, critical martensitic start and finish stresses, plastic flow stress, recovery strain limit, failure stress and plastic modulus. The data is correlated with the Brinson constitutive model modified to account for full range loading. The ratio of austenite to martensite moduli was found to be 5.8 and the secondary modulus (stress-induced martensite) was found to be smaller by a factor of two when compared to the modulus of (stress-free) thermally induced martensite. The influence of the initial temperature treatment of the nitinol was shown to be pronounced within the transformation range. Reasonably accurate correlation is obtained with the modified Brinson constitutive model although there is some discrepancy in critical stress predictions which is partially attributed to experimental scatter.

  20. Undercooled and rapidly quenched Ni-Mo alloys

    SciTech Connect (OSTI)

    Tewari, S.N.; Glasgow, T.K.

    1986-01-01

    Hypoeutectic, eutectic, and hypereutectic nickel-molybdenum alloys were rapidly solidified by both bulk undercooling and melt spinning techniques. Alloys were undercooled in both electromagnetic levitation and differential thermal analysis equipment. The rate of recalescence depended upon the degree of initial undercooling and the nature (faceted or nonfaceted) of the primary nucleating phase. Alloy melts were observed to undercool more in the presence of primary Beta (NiMo intermetallic) phase than in gamma (fcc solid solution) phase. Melt spinning resulted in an extension of molybdenum solid solubility in gamma nickel, from 28 to 37.5 at % Mo. Although the microstructures observed by undercooling and melt spinning were similar the microsegregation pattern across the gamma dendries was different. The range of microstructures evolved was analyzed in terms of the nature of the primary phase to nucleate, its subsequent dendritic growth, coarsening and fragmentation, and final solidification of interfenderitic liquid.

  1. CH{sub 4}-CO{sub 2} reforming over Ni-substituted barium hexaaluminate catalysts

    SciTech Connect (OSTI)

    Gardner, Todd H. [U.S. DOE; Spivey, James J. [ORISE; Kugler, Edwin L.; Pakhare, Devendra

    2013-03-30

    A series of Ni-substituted barium hexaaluminate catalysts, Ba{sub 0.75}Ni{sub y}Al{sub 12?y}O{sub 19??} (y = 0.4, 0.6 and 1.0), were tested for CO{sub 2} reforming of CH{sub 4} at temperatures between 200 and 900 °C. Temperature programmed surface reaction results show that the reaction lights-off in a temperature range between 448 and 503 °C with a consistent decrease in light-off temperature with increasing Ni substitution. Isothermal runs performed at 900 °C show near equilibrium conversion and stable product concentrations for 18 h on all catalysts. Temperature programmed oxidation of the used catalysts show that the amount of carbon deposited on the catalyst increases with Ni substitution. High resolution XRD of the used Ba{sub 0.75}Ni{sub 0.4}Al{sub 11.6}O{sub 19??} catalyst shows a statistically significant contraction of the unit cell which is the result of NiO reduction from the lattice. XRD of the used catalyst also confirms the presence of graphitic carbon. XPS and ICP measurements of the as prepared catalysts show that lower levels of Ni substitution result in an increasing proportion of Ba at the surface.

  2. Structural and Electrical Functionality of NiO Interfacial Films in Bulk Heterojunction Organic Solar Cells

    SciTech Connect (OSTI)

    Irwin, M.D.; Servaites, J.D.; Buchholz, B.D.; Leever, B.J.; Liu, J.; Emery, J.D.; Zhang, M.; Song, J.H.; Durstock, M.F.; Freeman, Arthur J.; Bedzyk, M.J.; Hersam, Mark C.; Chang, R.P.H.; Ratner, Mark A.; Marks, Tobin J.

    2011-01-01

    The functionality of NiO interfacial layers in enhancing bulk heterojunction (BHJ) organic photovoltaic (OPV) cell performance is investigated by integrated characterization of the electrical properties, microstructure, electronic structure, and optical properties of thin NiO films grown on glass/ITO electrodes. These NiO layers are found to be advantageous in BHJ OPV applications due to favorable energy band levels, interface passivation, p-type character, crystallinity, smooth surfaces, and optical transparency. The NiO overlayers are fabricated via pulsed-laser deposition and found to have a work function of ?5.3 eV. They are investigated by both topographic and conductive atomic force microscopy and shown to passivate interfacial charge traps. The films also have an average optical transparency of >80% in the visible range, crucial for efficient OPV function, and have a near-stoichiometric Ni:O surface composition. By grazing-incidence X-ray diffraction, the NiO thin films are shown to grow preferentially in the (111) direction and to have the fcc NaCl crystal structure. Diodes of p?n structure and first-principles electronic structure calculations indicate that the NiO interlayer is preferentially conductive to holes, with a lower hole charge carrier effective mass versus that of electrons. Finally, the implications of these attributes in advancing efficiencies for state-of-the-art OPV systems—in particular, improving the open circuit voltage (V{sub OC})—are discussed.

  3. On characterisation of wire-arc-plasma-sprayed Ni on alumina substrate

    SciTech Connect (OSTI)

    Laik, A.; Chakravarthy, D.P.; Kale, G.B. . E-mail: gbkale@apsara.barc.ernet.in

    2005-08-15

    A study was carried out on metal-ceramic bonding produced by the technique of wire-arc-plasma spraying of Ni on Al{sub 2}O{sub 3} substrate. The Ni layer and the Ni/Al{sub 2}O{sub 3} interface were characterised using optical and electro-optic techniques. The plasma-deposited Ni layer shows a uniform lamellar microstructure throughout the cross-section. The metal-ceramic interface was found to be well bonded with no pores, flaws or cracks in the as-sprayed condition. The optical metallography and concentration profiles established with the help of an electron probe microanalyser confirmed the absence of any intermediate phase at the interface. An annealing treatment at 1273 K for 24 h on the plasma-coated samples did not result in formation of any intermetallic compound or spinel at the Ni/Al{sub 2}O{sub 3} interface. This indicates that the oxygen picked up by Ni during the spraying operation is less than the threshold value required to form the spinel NiAl{sub 2}O{sub 4}.

  4. (001) Oriented piezoelectric films prepared by chemical solution deposition on Ni foils

    SciTech Connect (OSTI)

    Yeo, Hong Goo, E-mail: hxy162@psu.edu; Trolier-McKinstry, Susan [Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

    2014-07-07

    Flexible metal foil substrates are useful in some microelectromechanical systems applications including wearable piezoelectric sensors or energy harvesters based on Pb(Zr,Ti)O? (PZT) thin films. Full utilization of the potential of piezoelectrics on metal foils requires control of the film crystallographic texture. In this study, (001) oriented PZT thin films were grown by chemical solution deposition (CSD) on Ni foil and Si substrates. Ni foils were passivated using HfO? grown by atomic layer deposition in order to suppress substrate oxidation during subsequent thermal treatment. To obtain the desired orientation of PZT film, strongly (100) oriented LaNiO? films were integrated by CSD on the HfO? coated substrates. A high level of (001) LaNiO? and PZT film orientation were confirmed by X-ray diffraction patterns. Before poling, the low field dielectric permittivity and loss tangents of (001) oriented PZT films on Ni are near 780 and 0.04 at 1 kHz; the permittivity drops significantly on poling due to in-plane to out-of-plane domain switching. (001) oriented PZT film on Ni displayed a well-saturated hysteresis loop with a large remanent polarization ~36 ?C/cm², while (100) oriented PZT on Si showed slanted P-E hysteresis loops with much lower remanent polarizations. The |e{sub 31,f}| piezoelectric coefficient was around 10.6 C/m² for hot-poled (001) oriented PZT film on Ni.

  5. Carbon-Supported IrNi Core-Shell Nanoparticles: Synthesis Characterization and Catalytic Activity

    SciTech Connect (OSTI)

    K Sasaki; K Kuttiyiel; L Barrio; D Su; A Frenkel; N Marinkovic; D Mahajan; R Adzic

    2011-12-31

    We synthesized carbon-supported IrNi core-shell nanoparticles by chemical reduction and subsequent thermal annealing in H{sub 2}, and verified the formation of Ir shells on IrNi solid solution alloy cores by various experimental methods. The EXAFS analysis is consistent with the model wherein the IrNi nanoparticles are composed of two-layer Ir shells and IrNi alloy cores. In situ XAS revealed that the Ir shells completely protect Ni atoms in the cores from oxidation or dissolution in an acid electrolyte under elevated potentials. The formation of Ir shell during annealing due to thermal segregation is monitored by time-resolved synchrotron XRD measurements, coupled with Rietveld refinement analyses. The H{sub 2} oxidation activity of the IrNi nanoparticles was found to be higher than that of a commercial Pt/C catalyst. This is predominantly due to Ni-core-induced Ir shell contraction that makes the surface less reactive for IrOH formation, and the resulting more metallic Ir surface becomes more active for H{sub 2} oxidation. This new class of core-shell nanoparticles appears promising for application as hydrogen anode fuel cell electrocatalysts.

  6. Fabrication of hollow mesoporous NiO hexagonal microspheres via hydrothermal process in ionic liquid

    SciTech Connect (OSTI)

    Zhao, Jinbo; School of Materials Science and Engineering, Shandong University, 250061, Jinan ; Wu, Lili; School of Materials Science and Engineering, Shandong University, 250061, Jinan ; Zou, Ke; School of Materials Science and Engineering, Shandong University, 250061, Jinan

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Ni(OH){sub 2} precursors were synthesized in ionic liquid and water solution by hydrothermal method. Black-Right-Pointing-Pointer NiO hollow microspheres were prepared by thermal treatment of Ni(OH){sub 2} precursors. Black-Right-Pointing-Pointer NiO hollow microspheres were self-assembled by mesoporous cubic and hexagonal nanocrystals with high specific surface area. Black-Right-Pointing-Pointer The mesoporous structure is stable at 773 K. Black-Right-Pointing-Pointer The ionic liquid absorbed on the O-terminate surface of the crystals to form hydrogen bond and played key roles in determining the final shape of the NiO novel microstructure. -- Abstract: The novel NiO hexagonal hollow microspheres have been successfully prepared by annealing Ni(OH){sub 2}, which was synthesized via an ionic liquid-assisted hydrothermal method. The samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), N{sub 2} adsorption-desorption and Fourier transform infrared spectrometer (FTIR). The results show that the hollow NiO microstructures are self-organized by mesoporous cubic and hexagonal nanocrystals. The mesoporous structure possessed good thermal stability and high specific surface area (ca. 83 m{sup 2}/g). The ionic liquid 1-butyl-3methylimidazolium tetrafluoroborate ([Bmim][BF{sub 4}]) was found to play a key role in controlling the morphology of NiO microstructures during the hydrothermal process. The special hollow mesoporous architectures will have potential applications in many fields, such as catalysts, absorbents, sensors, drug-delivery carriers, acoustic insulators and supercapacitors.

  7. Features of a priori heavy doping of the n-TiNiSn intermetallic semiconductor

    SciTech Connect (OSTI)

    Romaka, V. A.; Rogl, P.; Romaka, V. V.; Hlil, E. K.; Stadnyk, Yu. V.; Budgerak, S. M.

    2011-07-15

    The crystal structure, the distribution of electron density, and the energy, kinetic, and magnetic properties of the n-TiNiSn intermetallic semiconductor are investigated. It is shown that a priori doping of n-TiNiSn with donors originates from partial, up to 0.5 at %, redistribution of Ti and Ni atoms in crystallographic sites of Ti atoms. The correlation is established between the donor concentration, amplitude of modulation of the continuous energy bands, and degree of filling of low-scale fluctuation potential wells with charge carriers. The results obtained are discussed within the Shklovskii-Efros model of a heavily doped and compensated semiconductor.

  8. In Situ Observations of the Atomistic Mechanisms of Ni Catalyzed Low Temperature Graphene Growth

    E-Print Network [OSTI]

    Patera, Laerte L.; Africh, Cristina; Weatherup, Robert S.; Blume, Raoul; Bhardwaj, Sunil; Castellarin-Cudia, Carla; Knop-Gericke, Axel; Schloegl, Robert; Comelli, Giovanni; Hofmann, Stephan; Cepek, Cinzia

    2013-08-08

    , CA (283.2eV), CDis (283.8eV), CGr (284.4eV), and CB (284.8eV). The C1s spectrum of the graphene covered Ni(111) surface in Figure 3c shows a dominant CB component, ?72% of the total C1s intensity, with the CDis and CGr contributing ?12% and ?15... -range ordered structure, would show a component of similar binding energy resulting from a similar charge transfer from Ni to embedded C atoms. This broader assignment of CA could account for previous observations of a CA peak under conditions where Ni2C may...

  9. Improved synthesis and crystal structure of the flexible pillared layer porous coordination polymer: Ni(1,2-bis(4-pyridyl)ethylene)[Ni(CN)(4)

    SciTech Connect (OSTI)

    Wong-Ng, W.; Culp, J. T.; Chen, Y. S.; Zavalij, P.; Espinal, L.; Siderius, D. W.; Allen, A. J.; Scheins, S Matranga, C

    2013-04-04

    This paper reports our synthesis of flexible coordination polymer, Ni(L)[Ni(CN){sub 4}], (L = 1,2-bis(4- pyridyl)ethylene (nicknamed bpene)), and its structural characterization using synchrotron single crystal X-ray diffraction. The structure of the purplish crystals has been determined to be monoclinic, space group P2{sub 1}/m, a = 13.5941(12) Å, b = 14.3621(12) Å, c = 14.2561(12) Å, {beta} = 96.141(2){degrees|, V = 2767.4(4) Å{sup 3}, Z = 4, D{sub c} = 1.46 g cm{sup -1}. Ni(bpene)[Ni(CN){sub 4}] assumes a pillared layer structure with layers defined by Ni[Ni(CN){sub 4}]{sub n} nets and bpene ligands acting as pillars. With the present crystallization technique which involves the use of concentrated ammonium hydroxide solution and dimethyl sulfoxide (DMSO), disordered free bpene ligands and solvents of crystallization (DMSO and water molecules) occupy the pores, resulting in a formula of Ni(bpene)[Ni(CN){sub 4}](1/2)bpene.DMSO.2H{sub 2}O, or Ni{sub 2}N{sub 7}C{sub 24}H{sub 2}.5SO{sub 3}. Without the inclusion of free bpene ligands and solvent molecules, the free volume is approximately 61% of the total volume; this free volume fraction is reduced to 50% with the free ligands present. Pores without the free ligands were found to have a local diameter of 5.7 Å and a main aperture of 3.5 Å. Based on the successful crystal synthesis, we also devised a new bulk synthetic technique which yielded a polycrystalline material with a significantly improved CO{sub 2} uptake as compared to the originally reported powder material. The improved synthetic technique yielded a polycrystalline material with 40% higher CO{sub 2} uptake compared to the previously reported powder material. An estimated 14.4 molecules of CO{sub 2} per unit cell was obtained.

  10. A semisynthetic strategy leads to alteration of the backbone amidate ligand in the NiSOD active site

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Campeciño, Julius O.; Dudycz, Lech W.; Tumelty, David; Berg, Volker; Cabelli, Diane E.; Maroney, Michael J.

    2015-07-01

    Computational investigations have implicated the amidate ligand in nickel superoxide dismutase (NiSOD) in stabilizing Ni-centered redox catalysis and in preventing cysteine thiolate ligand oxidation. To test these predictions, we have used an experimental approach utilizing a semisynthetic scheme that employs native chemical ligation of a pentapeptide (HCDLP) to recombinant S. coelicolor NiSOD lacking these N-terminal residues, N?5-NiSOD. Wild-type enzyme produced in this manner exhibits the characteristic spectral properties of recombinant WT-NiSOD and is as catalytically active. The semisynthetic scheme was also employed to construct a variant where the amidate ligand was converted to a secondary amine, H1*-NiSOD, a novel strategymore »that retains a backbone N-donor atom. The H1*-NiSOD variant was found to have only ~1% of the catalytic activity of the recombinant wild-type enzyme, and had altered spectroscopic properties. X-ray absorption spectroscopy reveals a four-coordinate planar site with N2S2-donor ligands, consistent with electronic absorption spectroscopic results indicating that the Ni center in H1*-NiSOD is mostly reduced in the as-isolated sample, as opposed to 50:50 Ni(II)/Ni(III) mixture that is typical for the recombinant wild-type enzyme. The EPR spectrum of as-isolated H1*-NiSOD accounts for ~11% of the Ni in the sample and is similar to WT-NiSOD, but more axial, with gz x,y. 14N-hyperfine is observed on gz« less

  11. Shape memory and superelasticity in polycrystalline Cu-Al-Ni microwires

    E-Print Network [OSTI]

    Chen, Ying

    We report a strategy to significantly improve the ductility and achieve large superelastic and shape memory strains in polycrystalline Cu–Al–Ni shape memory alloys that are normally brittle. We use a liquid-phase (Taylor) ...

  12. Contact-induced spin polarization of monolayer hexagonal boron nitride on Ni(111)

    SciTech Connect (OSTI)

    Ohtomo, Manabu; Entani, Shiro; Matsumoto, Yoshihiro; Naramoto, Hiroshi; Sakai, Seiji; Yamauchi, Yasushi; Kuzubov, Alex A.; Eliseeva, Natalya S.; Avramov, Pavel V.

    2014-02-03

    Hexagonal boron nitride (h-BN) is a promising barrier material for graphene spintronics. In this Letter, spin-polarized metastable de-excitation spectroscopy (SPMDS) is employed to study the spin-dependent electronic structure of monolayer h-BN/Ni(111). The extreme surface sensitivity of SPMDS enables us to elucidate a partial filling of the in-gap states of h-BN without any superposition of Ni 3d signals. The in-gap states are shown to have a considerable spin polarization parallel to the majority spin of Ni. The positive spin polarization is attributed to the ?-d hybridization and the effective spin transfer to the nitrogen atoms at the h-BN/Ni(111) interface.

  13. Understanding and development of combined acoustic and magnetic actuation of Ni?MnGa single crystals

    E-Print Network [OSTI]

    Techapiesancharoenkij, Ratchatee, 1979-

    2007-01-01

    Ni-Mn-Ga based ferromagnetic shape memory alloys (FSMAs) have emerged as a promising new class of active materials capable of producing a large (several %) magnetic-field-induced strain (MFIS). FSMAs still have several ...

  14. Thermodynamic modeling and experimental validation of the Fe-Al-Ni-Cr-Mo alloy system

    SciTech Connect (OSTI)

    Teng, Zhenke; Zhang, F; Miller, Michael K; Liu, Chain T; Huang, Shenyan; Chou, Y.T.; Tien, R; Chang, Y A; Liaw, Peter K

    2012-01-01

    NiAl-type precipitate-strengthened ferritic steels have been known as potential materials for the steam turbine applications. In this study, thermodynamic descriptions of the B2-NiAl type nano-scaled precipitates and body-centered-cubic (BCC) Fe matrix phase for four alloys based on the Fe-Al-Ni-Cr-Mo system were developed as a function of the alloy composition at the aging temperature. The calculated phase structure, composition, and volume fraction were validated by the experimental investigations using synchrotron X-ray diffraction and atom probe tomography. With the ability to accurately predict the key microstructural features related to the mechanical properties in a given alloy system, the established thermodynamic model in the current study may significantly accelerate the alloy design process of the NiAl-strengthened ferritic steels.

  15. Hydroxyl and molecular H2O diffusivity in a haploandesitic melt Huaiwei Ni a,b,

    E-Print Network [OSTI]

    Zhang, Youxue

    Hydroxyl and molecular H2O diffusivity in a haploandesitic melt Huaiwei Ni a,b, , Zhengjiu Xu c) rather than hydroxyl group (OH), water diffusivity has been experimentally determined for a variety

  16. Thermal properties of Ni-substituted LaCoO{sub 3} perovskite

    SciTech Connect (OSTI)

    Thakur, Rasna Thakur, Rajesh K. Gaur, N. K.; Srivastava, Archana

    2014-04-24

    With the objective of exploring the unknown thermodynamic behavior of LaCo{sub 1?x}Ni{sub x}O{sub 3} family, we present here an investigation of the temperature-dependent (10K ? T ? 300K) thermodynamic properties of LaCo{sub 1?x}Ni{sub x}O{sub 3} (x=0.1, 0.3, 0.5). The specific heat of LaCoO3 with Ni doping in the perovskite structure at B-site has been studied by means of a Modified Rigid Ion Model (MRIM). This replacement introduces large cation variance at B-site hence the specific heat increases appreciably. We report here probably for the first time the cohesive energy, Reststrahlen frequency (?) and Debye temperature (?{sub D}) of LaCo{sub 1?x}Ni{sub x}O{sub 3} compounds.

  17. Measuring relative performance of an EDS detector using a NiO...

    Office of Scientific and Technical Information (OSTI)

    performance of energy dispersive spectrometers (EDS) on a TEM is discussed. A NiO thin-film standard fabricated at Sandia CA is used. A performance parameter,, is measured and...

  18. Scattering of xenon from Ni,,111...: Collision-induced corrugation and energy transfer dynamics

    E-Print Network [OSTI]

    , Stanford, California 94305 Received 19 April 1999; accepted 26 October 1999 Experiments have been conducted in which a beam of xenon atoms collides with a clean Ni 111 surface, and the speed and angular super- sonic molecular

  19. Fabrication and characterization of porous NiTi Shape Memory Alloy by elevated pressure sintering 

    E-Print Network [OSTI]

    Vandygriff, Eric Layton

    2002-01-01

    have not been adequately developed. Currently, three methods are commonly used for producing porous NiTi SMAs from elemental powders. These methods include conventional sintering, Self-propagating High-temperature Synthesis (SHS), and sintering...

  20. Study on Degradation of Solid Oxide Fuel Cell With Pure Ni Anode Zhenjun Jiaoa

    E-Print Network [OSTI]

    Kasagi, Nobuhide

    Study on Degradation of Solid Oxide Fuel Cell With Pure Ni Anode Zhenjun Jiaoa , Naoki Shikazonoa Solid oxide fuel cell (SOFC) has attracted more and more attentions in the last few decades

  1. Isoscalar and neutron modes in the E 1 spectra of Ni isotopes...

    Office of Scientific and Technical Information (OSTI)

    Isoscalar and neutron modes in the E 1 spectra of Ni isotopes and the relevance of shell effects and the continuum Citation Details In-Document Search This content will become...

  2. Pressure-Induced Structural Phase Transition in CeNi: X-ray and...

    Office of Scientific and Technical Information (OSTI)

    Pressure-Induced Structural Phase Transition in CeNi: X-ray and Neutron Scattering Studies and First-Principles Calculations Citation Details In-Document Search This content will...

  3. Shape-Memory Transformations of NiTi: Minimum-Energy Pathways...

    Office of Scientific and Technical Information (OSTI)

    Details In-Document Search This content will become publicly available on December 24, 2015 Title: Shape-Memory Transformations of NiTi: Minimum-Energy Pathways between Austenite,...

  4. Low Spring Index NiTi Coil Actuators for Use in Active Compression Garments

    E-Print Network [OSTI]

    Holschuh, Bradley T.

    This paper describes the modeling, development, and testing of low spring index nickel titanium (NiTi) coil actuators designed for use in wearable compression garments, and presents a prototype tourniquet system using these ...

  5. Computational Thermodynamics of CoNiGa High Temperature Shape Memory Alloys 

    E-Print Network [OSTI]

    Chari, Arpita

    2012-10-19

    Shape Memory Alloys (SMAs) are advanced materials with interesting properties such as pseudoelasticity (PE) and the shape memory effect (SME). Recently, the CoNiGa system has emerged as the basis for very promising High ...

  6. Structure and magnetic properties of Ce?(Ni/Al/Ga)??-A...

    Office of Scientific and Technical Information (OSTI)

    Ce(NiAlGa)-A new phase with the LaAl structure type Janka, Oliver Univ. of California, Davis, CA (United States); Westfalische Wilhelms-Universitat, Munster...

  7. Graphene-on-Insulator Transistors Made Using C on Ni Chemical-Vapor Deposition

    E-Print Network [OSTI]

    Keast, Craig L.

    Graphene transistors are made by transferring a thin graphene film grown on Ni onto an insulating SiO[subscript 2] substrate. The properties and integration of these graphene-on-insulator transistors are presented and ...

  8. The thermomechanical constitutive experimentation of NiTi shape memory alloy strips and rods 

    E-Print Network [OSTI]

    Howard, Stephen David

    1995-01-01

    The purpose of this thesis was to study the effect of temperature on the thermomechanical constitutive behavior of NiTi shape memory alloy strip and rod specimens. The stress-strain relationship is analyzed for isothermal monotonic tensile testing...

  9. Hydrogen absorption characteristics of amorphous LaNi[sub 5. 0] films prepared by reactive sputtering

    SciTech Connect (OSTI)

    Sakaguchi, H.; Tsujimoto, T.; Adachi, Ginya (Osaka University, Suita (Japan))

    1993-01-01

    Amorphous LaNi[sub 5] thin films are expected to be one of the promising materials for use in hydrogen separation and battery electrodes, because the durability of the films is great in regard to the hydrogen absorption-desorption cycling process and the films have excellent resistance to harmful impurities in the hydrogen gas in comparison with the crystalline bulk material. An amorphous LaNi[sub 5.0] film having high hydrogen density and low hydrogen-induced stress was obtained by means of a reactive sputtering method using an Ar-H[sub 2] gas mixture. Pressure-composition isotherms show that the amount of hydrogen (H/LaNi[sub 5.0]) taken up by a formula weight of LaNi[sub 5.0] is about 1.5 times larger for the reactive sputtered film than for the conventional sputtered film prepared by using Ar gas. 18 refs., 1 fig, 1 tabs.

  10. Magnetism of NiMn2O4-Fe3O4 spinel interfaces

    E-Print Network [OSTI]

    Nelson-Cheeseman, B. B.

    2007-01-01

    2 O 4 –Fe 3 O 4 spinel interfaces B. B. Nelson-Cheeseman,isostructural spinel-spinel interface of NiMn 2 O 4 (NMO)–Feis preserved, both bulk and interface sensitive measurements

  11. Fu-Hao Chen 12/22/2014 Fabrication of small apertures (diameter of 30~40um) on 25 um-thick Teflon using

    E-Print Network [OSTI]

    Movileanu, Liviu

    um. 7. Squeeze the rectangular Teflon film in the cartridge holder, which are two plastic plates. Put the cartridge holder in the gap between the two electrodes; make sure the electrodes are aiming

  12. Recovery Act: Novel Kerf-Free PV Wafering that provides a low-cost approach to generate wafers from 150um to 50um in thickness

    SciTech Connect (OSTI)

    Fong, Theodore E.

    2013-05-06

    The technical paper summarizes the project work conducted in the development of Kerf-Free silicon wafering equipment for silicon solar wafering. This new PolyMax technology uses a two step process of implantation and cleaving to exfoliate 50um to 120um wafers with thicknesses ranging from 50um to 120um from a 125mm or 156mm pseudo-squared silicon ingot. No kerf is generated using this method of wafering. This method of wafering contrasts with the current method of making silicon solar wafers using the industry standard wire saw equipment. The report summarizes the activity conducted by Silicon Genesis Corporation in working to develop this technology further and to define the roadmap specifications for the first commercial proto-type equipment for high volume solar wafer manufacturing using the PolyMax technology.

  13. Experimental determination of band offsets of NiO-based thin film heterojunctions

    SciTech Connect (OSTI)

    Kawade, Daisuke; Sugiyama, Mutsumi, E-mail: mutsumi@rs.noda.tus.ac.jp [Faculty of Science and Technology/Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510 (Japan); Chichibu, Shigefusa F. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba, Sendai 980–8577 (Japan)

    2014-10-28

    The energy band diagrams of NiO-based solar cell structures that use various n-type oxide semiconductors such as ZnO, Mg{sub 0.3}Zn{sub 0.7}O, Zn{sub 0.5}Sn{sub 0.5}O, In{sub 2}O{sub 3}:Sn (ITO), SnO{sub 2}, and TiO{sub 2} were evaluated by photoelectron yield spectroscopy. The valence band discontinuities were estimated to be 1.6?eV for ZnO/NiO and Mg{sub 0.3}Zn{sub 0.7}O/NiO, 1.7?eV for Zn{sub 0.5}Sn{sub 0.5}O/NiO and ITO/NiO, and 1.8?eV for SnO{sub 2}/NiO and TiO{sub 2}/NiO heterojunctions. By using the valence band discontinuity values and corresponding energy bandgaps of the layers, energy band diagrams were developed. Judging from the band diagram, an appropriate solar cell consisting of p-type NiO and n-type ZnO layers was deposited on ITO, and a slight but noticeable photovoltaic effect was obtained with an open circuit voltage (V{sub oc}) of 0.96?V, short circuit current density (J{sub sc}) of 2.2??A/cm{sup 2}, and fill factor of 0.44.

  14. Heat treatment of NiCrFe alloy to optimize resistance to intergrannular stress corrosion

    DOE Patents [OSTI]

    Steeves, Arthur F. (Schenectady, NY); Bibb, Albert E. (Clifton Park, NY)

    1984-01-01

    A process of producing a NiCrFe alloy having a high resistance to stress corrosion cracking comprising heating a NiCrFe alloy to a temperature sufficient to enable the carbon present in the alloy body in the form of carbide deposits to enter into solution, rapidly cool the alloy body, and heat the cooled body to a temperature between 1100.degree. to 1500.degree. F. for about 1 to 30 hours.

  15. Determination of mechanical properties of Ni-Cr-P amorphous alloys 

    E-Print Network [OSTI]

    Kondlapudi, Swaroop Kumar R

    1991-01-01

    DETERMINATION OF MECHANICAL PROPERTIES OF Ni-Cr-P AMORPHOUS ALLOYS A Thesis by SWAROOP KUMAR R. KONDLAPUDI Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE August 1991 Major Subject: Mechanical Engineering DETERMINATION OF MECHANICAL PROPERTIES OF Ni-Cr-P AMORPHOUS ALLOYS A Thesis by SWAROOP KUMAR R. KONDLAPUDI Approved as to style and content by I-t (, :()o . e, ~&am A. Wolfenden...

  16. Experimental determination and thermodynamic modeling of the Ni-Re binary system

    SciTech Connect (OSTI)

    Yaqoob, Khurram [Chimie Metallurgique des Terres Rares (CMTR), Institut de Chimie et des Materiaux Paris-Est (ICMPE), 2-8 rue Henri Dunant, 94320 Thiais Cedex (France)] [Chimie Metallurgique des Terres Rares (CMTR), Institut de Chimie et des Materiaux Paris-Est (ICMPE), 2-8 rue Henri Dunant, 94320 Thiais Cedex (France); Joubert, Jean-Marc, E-mail: jean-marc.joubert@icmpe.cnrs.fr [Chimie Metallurgique des Terres Rares (CMTR), Institut de Chimie et des Materiaux Paris-Est (ICMPE), 2-8 rue Henri Dunant, 94320 Thiais Cedex (France)] [Chimie Metallurgique des Terres Rares (CMTR), Institut de Chimie et des Materiaux Paris-Est (ICMPE), 2-8 rue Henri Dunant, 94320 Thiais Cedex (France)

    2012-12-15

    The phase diagram of the Ni-Re binary system has been partially reinvestigated by chemical, structural and thermal characterization of the arc melted alloys. The experimental results obtained during the present investigation were combined with the literature data and a new phase diagram of the Ni-Re binary system is proposed. In comparison with the Ni-Re phase diagram proposed by Nash et al. in 1985 [1], significant differences in the homogeneity domains, freezing ranges and peritectic reaction temperature were evidenced. On the other hand, thermodynamic modeling of the studied system by using the new experimental information has also been carried out with the help of the CALPHAD method. The calculated Ni-Re phase diagram showed a good agreement with the selected experimental information. - Graphical abstract: Ni-Re phase diagram according to the present study. Highlights: Black-Right-Pointing-Pointer Re-investigation of the Ni-Re phase diagram. Black-Right-Pointing-Pointer Extended phase field of the hcp phase. Black-Right-Pointing-Pointer Different freezing ranges and peritectic reaction temperature. Black-Right-Pointing-Pointer Thermodynamic modeling of the studied system by using the CALPHAD method.

  17. An Update on Improvements to NiCE Support for RELAP-7

    SciTech Connect (OSTI)

    McCaskey, Alex; Wojtowicz, Anna; Deyton, Jordan H.; Patterson, Taylor C.; Billings, Jay Jay

    2015-01-01

    The Multiphysics Object-Oriented Simulation Environment (MOOSE) is a framework that facilitates the development of applications that rely on finite-element analysis to solve a coupled, nonlinear system of partial differential equations. RELAP-7 represents an update to the venerable RELAP-5 simulator that is built upon this framework and attempts to model the balance-of-plant concerns in a full nuclear plant. This report details the continued support and integration of RELAP-7 and the NEAMS Integrated Computational Environment (NiCE). RELAP-7 is fully supported by the NiCE due to on-going work to tightly integrate NiCE with the MOOSE framework, and subsequently the applications built upon it. NiCE development throughout the first quarter of FY15 has focused on improvements, bug fixes, and feature additions to existing MOOSE-based application support. Specifically, this report will focus on improvements to the NiCE MOOSE Model Builder, the MOOSE application job launcher, and the 3D Nuclear Plant Viewer. This report also includes a comprehensive tutorial that guides RELAP-7 users through the basic NiCE workflow: from input generation and 3D Plant modeling, to massively parallel job launch and post-simulation data visualization.

  18. Interplay between out-of-plane anisotropic L1{sub 1}-type CoPt and in-plane anisotropic NiFe layers in CoPt/NiFe exchange springs

    SciTech Connect (OSTI)

    Saravanan, P.; Hsu, Jen-Hwa Tsai, C. L.; Tsai, C. Y.; Lin, Y. H.; Kuo, C. Y.; Wu, J.-C.; Lee, C.-M.

    2014-06-28

    Films of L1{sub 1}-type CoPt/NiFe exchange springs were grown with different NiFe (Permalloy) layer thickness (t{sub NiFe}?=?0–10?nm). X-ray diffraction analysis reveals that the characteristic peak position of NiFe(111) is not affected by the CoPt-layer—confirming the absence of any inter-diffusion between the CoPt and NiFe layers. Magnetic studies indicate that the magnetization orientation of NiFe layer can be tuned through varying t{sub NiFe} and the perpendicular magnetic anisotropy of L1{sub 1}-type CoPt/NiFe films cannot sustain for t{sub NiFe} larger than 3.0?nm due to the existence of exchange interaction at the interface of L1{sub 1}-CoPt and NiFe layers. Magnetic force microscopy analysis on the as-grown samples shows the changes in morphology from maze-like domains with good contrast to hazy domains when t{sub NiFe}???3.0?nm. The three-dimensional micro-magnetic simulation results demonstrate that the magnetization orientation in NiFe layer is not uniform, which continuously increases from the interface to the top of NiFe layer. Furthermore, the tilt angle of the topmost NiFe layers can be changed over a very wide range from a small number to about 75° by varying t{sub NiFe} from 1 to 10?nm. It is worth noting that there is an abrupt change in the magnetization direction at the interface, for all the t{sub NiFe} investigated. The results of present study demonstrate that the tunable tilted exchange springs can be realized with L1{sub 1}-type CoPt/NiFe bilayers for future applications in three-axis magnetic sensors or advanced spintronic devices demanding inclined magnetic anisotropy.

  19. Metallic glass alloys of Zr, Ti, Cu and Ni

    DOE Patents [OSTI]

    Lin, Xianghong (Pasadena, CA); Peker, Atakan (Pasadena, CA); Johnson, William L. (Pasadena, CA)

    1997-01-01

    At least quaternary alloys form metallic glass upon cooling below the glass transition temperature at a rate less than 10.sup.3 K/s. Such alloys comprise titanium from 19 to 41 atomic percent, an early transition metal (ETM) from 4 to 21 atomic percent and copper plus a late transition metal (LTM) from 49 to 64 atomic percent. The ETM comprises zirconium and/or hafnium. The LTM comprises cobalt and/or nickel. The composition is further constrained such that the product of the copper plus LTM times the atomic proportion of LTM relative to the copper is from 2 to 14. The atomic percentage of ETM is less than 10 when the atomic percentage of titanium is as high as 41, and may be as large as 21 when the atomic percentage of titanium is as low as 24. Furthermore, when the total of copper and LTM are low, the amount of LTM present must be further limited. Another group of glass forming alloys has the formula (ETM.sub.1-x Ti.sub.x).sub.a Cu.sub.b (Ni.sub.1-y Co.sub.y).sub.c wherein x is from 0.1 to 0.3, y.cndot.c is from 0 to 18, a is from 47 to 67, b is from 8 to 42, and c is from 4 to 37. This definition of the alloys has additional constraints on the range of copper content, b.

  20. Electrochemical Testing of Ni-Cr-Mo-Gd Alloys

    SciTech Connect (OSTI)

    T. E. Lister; R. E. Mizia; H. Tian

    2005-10-01

    The waste package site recommendation design specified a boron-containing stainless steel, Neutronit 976/978, for fabrication of the internal baskets that will be used as a corrosion-resistant neutron-absorbing material. Recent corrosion test results gave higher-than-expected corrosion rates for this material. The material callout for these components has been changed to a Ni-Cr-Mo-Gd alloy (ASTM-B 932-04, UNS N06464) that is being developed at the Idaho National Laboratory. This report discusses the results of initial corrosion testing of this material in simulated in-package environments that could contact the fuel baskets after breach of the waste package outer barrier. The corrosion test matrix was executed using the potentiodynamic and potentiostatic electrochemical test techniques. The alloy performance shows low rates of general corrosion after initial removal of a gadolinium-rich second phase that intersects the surface. The high halide-containing test solutions exhibited greater tendencies toward initiation of crevice corrosion.

  1. Armazenar energia mais rapidamente O armazenamento de energia um desafio tecnolgico ainda por vencer. Os supercondensadores

    E-Print Network [OSTI]

    Instituto de Sistemas e Robotica

    numa aplicação real, envolvendo, por exemplo, o armazenamento de energia pro- duzida por turbina eólicaArmazenar energia mais rapidamente O armazenamento de energia é um desafio tecnológico ainda por: armazena muita energia e de forma muito rápida. Além de ser fabricado através de um processo sim- ples, com

  2. Insulating and metallic spin glass in Ni-doped KxFe2-ySe? single crystals

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ryu, Hyejin; Abeykoon, Milinda; Wang, Kefeng; Lei, Hechang; Lazarevic, N.; Warren, J. B.; Bozin, E. S.; Popovic, Z. V.; Petrovic, C.

    2015-05-04

    We report electron doping effects by Ni in KxFe2-?-yNiySe? (0.06 ? y ? 1.44) single crystal alloys. A rich ground state phase diagram is observed. A small amount of Ni (~ 4%) suppressed superconductivity below 1.8 K, inducing insulating spin glass magnetic ground state for higher Ni content. With further Ni substitution, metallic resistivity is restored. For high Ni concentration in the lattice the unit cell symmetry is high symmetry I4/mmm with no phase separation whereas both I4/m + I4/mmm space groups were detected in the phase separated crystals when concentration of Ni more »with the absence of crystalline Fe vacancy order.« less

  3. Observation of Precipitation Evolution in Fe-Ni-Mn-Ti-Al Maraging Steel using Atom Probe Tomography

    SciTech Connect (OSTI)

    Pereloma, E. V.; Stohr, R A; Miller, Michael K; Ringer, S. P.

    2009-01-01

    We describe the full decomposition sequence in an Fe-Ni-Mn-Ti-Al maraging steel during isothermal annealing at 550 C. Following significant pre-precipitation clustering reactions within the supersaturated martensitic solid solution, (Ni,Fe){sub 3}Ti and (Ni,Fe){sub 3}(Al,Mn) precipitates eventually form after isothermal aging for {approx}60 seconds. The morphology of the (Ni,Fe){sub 3}Ti particles changes gradually during aging from predominantly plate-like to rod-like, and, importantly, Mn and Al were observed to segregate to these precipitate/matrix interfaces. The (Ni,Fe){sub 3}(Al,Mn) precipitates occurred at two main locations: uniformly within the matrix and at the periphery of the (Ni,Fe){sub 3}Ti particles. We relate this latter mode of precipitation to the Mn-Al segregation.

  4. Insulating and metallic spin glass in Ni-doped K x Fe 2 - y Se 2 single crystals

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ryu, Hyejin; Abeykoon, Milinda; Wang, Kefeng; Lei, Hechang; Lazarevic, N.; Warren, J. B.; Bozin, E. S.; Popovic, Z. V.; Petrovic, C.

    2015-05-01

    We report electron doping effects by Ni in KxFe2-?-yNiySe?(0.06?y?1.44) single-crystal alloys. A rich ground-state phase diagram is observed. A small amount of Ni (~4%) suppressed superconductivity below 1.8 K, inducing insulating spin-glass magnetic ground state for higher Ni content. With further Ni substitution, metallic resistivity is restored. For high Ni concentration in the lattice the unit cell symmetry is high symmetry I4/mmm with no phase separation whereas both I4/m+I4/mmm space groups were detected in the phase separated crystals when concentration of Ni < Fe. The absence of superconductivity coincides with the absence of crystalline Fe vacancy order.

  5. TSNo s02-roberts104537-O Microscopic and Spectroscopic Speciation of Ni in Soils in the Vicinity of a Ni Refinery.

    E-Print Network [OSTI]

    Sparks, Donald L.

    . Quantification of Ni species in these soils will be presented using a principle component analysis approach. D.R. Authors ROBERTS* UNIV. OF DELAWARE G.S. SENESI UNIV. OF DELAWARE U. KUKIER USDA-ARS, BELTSVILLE, MD R. CHANEY USDA-ARS, BELTSVILLE, MD D.L. SPARKS UNIV. OF DELAWARE For more information, please contact

  6. Symmetry energy and the isoscaling properties of the fragments in multifragmentation of 40Ca+58Ni, 40Ar+58Ni, and 40Ar+58Fe reactions 

    E-Print Network [OSTI]

    Iglio, Jennifer Ann

    2007-09-17

    The symmetry energy and the isoscaling properties of the fragments produced in multifragmentation of 40Ar, 40Ca + 58Fe, 58Ni reactions at 25, 33, 45 and 53 MeV/nucleon were investigated within the framework of a statistical multifragmentation model...

  7. Exploring the influence of transfer channels on fusion reactions: The case of 40 Ca + 58,64 Ni

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bourgin, D.; Courtin, S.; Haas, F.; Goasduff, A.; Stefanini, A. M.; Montagnoli, G.; Montanari, D.; Corradi, L.; Huiming, J.; Scarlassara, F.; et al

    2015-01-29

    Fusion cross sections have been measured in the 40Ca + 58Ni and 40Ca + 64Ni systems at beam energies ranging from Elab = 104.75 MeV to 153.5 MeV using the Laboratori Nazionali di Legnaro electrostatic deflector. Distributions of barriers have been extracted from the experimental data. Preliminary coupled channel calculations were performed and hints of effects of neutron transfers on the fusion below the barrier in the 40Ca + 64Ni are discussed.

  8. Hydrogen Insertion Effects on the Electronic Structure of Equiatomic MgNi Traced by ab initio Calculations.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Hydrogen Insertion Effects on the Electronic Structure of Equiatomic MgNi Traced by ab initio-xxx / Received October 18, 2012. Doi: 10.5560/ ZNB.2012-xxx For equiatomic MgNi which can be hydrogenated up to the composition MgNiH1.6 at an absorption/desorption temperature of 200 °C, the effects of hydrogen are approached

  9. Effect of temperature and time on properties of Spark Plasma Sintered NiCuZn: Co ferrite

    E-Print Network [OSTI]

    Effect of temperature and time on properties of Spark Plasma Sintered NiCuZn: Co ferrite K. Zehani hundred MHz, and a high resistivity, but the conventional sintering temperature is too high for co. EXPERIMENTAL: Powders of basic oxides Fe2O3, NiO, CuO and ZnO and Co2O3 were used for the preparation of Ni

  10. In Situ Time-Resolved Characterization of Ni-MoO2 Catalysts for the Water-Gas Shift Reaction

    SciTech Connect (OSTI)

    Wen,W.; Calderon, J.; Brito, J.; Marinkovic, N.; Hanson, J.; Rodriquez, J.

    2008-01-01

    Active catalysts for the water-gas shift (WGS, CO + H2O ? H2 + CO2) reaction were synthesized from nickel molybdates ({beta}-NiMoO4 and nH2O{center_dot}NiMoO4) as precursors, and their structural transformations were monitored using in situ time-resolved X-ray diffraction and X-ray absorption near-edge spectroscopy. In general, the nickel molybdates were not stable and underwent partial reduction in the presence of CO or CO/H2O mixtures at high temperatures. The interaction of {beta}-NiMoO4 with the WGS reactants at 500 C led to the formation of a mixture of Ni (24 nm particle size) and MoO2 (10 nm particle size). These Ni-MoO2 systems displayed good catalytic activity at 350, 400, and 500 C. At 350 and 400 C, catalytic tests revealed that the Ni-MoO2 system was much more active than isolated Ni (some activity) or isolated MoO2 (negligible activity). Thus, cooperative interactions between the admetal and oxide support were probably responsible for the high WGS activity of Ni-MoO2. In a second synthetic approach, the NiMoO4 hydrate was reduced to a mixture of metallic Ni, NiO, and amorphous molybdenum oxide by direct reaction with H2 gas at 350 C. In the first pass of the water-gas shift reaction, MoO2 appeared gradually at 500 C with a concurrent increase of the catalytic activity. For these catalysts, the particle size of Ni (4 nm) was much smaller than that of the MoO2 (13 nm). These systems were found to be much more active WGS catalysts than Cu-MoO2, which in turn is superior to commercial low-temperature Cu-ZnO catalysts.

  11. BUILDING COUNTEREXAMPLES L.R.I., U.R.A. 410 du C.N.R.S.,

    E-Print Network [OSTI]

    Rusu, Irena

    three conditions hold: 1. neither G, nor ¯G has an even pair; 2. neither G, nor ¯G has a stable cutset; 3. neither G, nor ¯G has a star-cutset, then G or ¯G is diamond-free. We show that this conjecture formulated thirty years ago and it is neither proved, nor invalidated. Conjecture 1. (SPGC) A graph

  12. Metallic glass alloys of Zr, Ti, Cu and Ni

    DOE Patents [OSTI]

    Lin, X.; Peker, A.; Johnson, W.L.

    1997-04-08

    At least quaternary alloys form metallic glass upon cooling below the glass transition temperature at a rate less than 10{sup 3} K/s. Such alloys comprise titanium from 19 to 41 atomic percent, an early transition metal (ETM) from 4 to 21 atomic percent and copper plus a late transition metal (LTM) from 49 to 64 atomic percent. The ETM comprises zirconium and/or hafnium. The LTM comprises cobalt and/or nickel. The composition is further constrained such that the product of the copper plus LTM times the atomic proportion of LTM relative to the copper is from 2 to 14. The atomic percentage of ETM is less than 10 when the atomic percentage of titanium is as high as 41, and may be as large as 21 when the atomic percentage of titanium is as low as 24. Furthermore, when the total of copper and LTM are low, the amount of LTM present must be further limited. Another group of glass forming alloys has the formula (ETM{sub 1{minus}x}Ti{sub x}){sub a} Cu{sub b} (Ni{sub 1{minus}y}Co{sub y}){sub c} wherein x is from 0.1 to 0.3, y{center_dot}c is from 0 to 18, a is from 47 to 67, b is from 8 to 42, and c is from 4 to 37. This definition of the alloys has additional constraints on the range of copper content, b. 2 figs.

  13. A Si Photocathode Protected and Activated with a Catalytic Ti and Ni Composite Film for Solar Hydrogen Production in Water

    E-Print Network [OSTI]

    Lai, Yi-Hsuan; Park, Hyun S.; Zhang, Jenny Z.; Matthews, Peter D.; Wright, Dominic S.; Reisner, Erwin

    2015-02-04

    is consistent with the Ni species having a higher formal oxidation state than TiNicat and similar electronic characteristics to Ni(OH)2 and NiO. The Fourier-transformed Ni extended X-ray absorption fine structure (FT EXAFS) c(k)k2 spectrum of hydro- lyzed Ti... -based O2 evolution electrocata- lysts and photoanodes are only functional in neutral or alkaline conditions. However, operating close to pH neutral conditions can give rise to a pH gradient at the electrode surface.[13] This may lead to a non-optimal fill...

  14. Synthesis of nanocrystalline aluminum matrix composites reinforced with in situ devitrified Al-Ni-La amorphous particles

    E-Print Network [OSTI]

    Zhang, Zhihui H; Han, B Q; Witkin, D; Ajdelsztajn, L; Laverna, E J

    2006-01-01

    metals, RE = rare earth metals) alloys [4] provides a newwith Al and Ni, the rare earth metal La, however, has the

  15. Direct Measurement of the Nanoscale Mechanical Properties of NiTi Shape Memory Gordon A. Shaw1

    E-Print Network [OSTI]

    Crone, Wendy C.

    .035 µm with Nitinol (roughly 49.5 atomic % Ni). Subsequent to annealing, the 10 and 1.7 µm films were

  16. Three-dimensional multimodal imaging and analysis of biphasic microstructure in a Ti-Ni-Sn thermoelectric material

    E-Print Network [OSTI]

    Douglas, Jason E; Echlin, McLean P; Lenthe, William C; Seshadri, Ram; Pollock, Tresa M

    2015-01-01

    microstructure in a Ti–Ni–Sn thermoelectric material Jasonsolid-state option. Thermoelectric materials, which convertin biphasic hH- based thermoelectric materials. This work

  17. In Anthony Jameson, Ccile Paris, and Carlo Tasso (Eds.), User Modeling: Proceedings of the Sixth International Con-ference, UM97. Vienna, New York: Springer Wien New York. CISM, 1997. Available on-line from http://um.org.

    E-Print Network [OSTI]

    Mizoguchi, Riichiro

    International Con- ference, UM97. Vienna, New York: Springer Wien New York. © CISM, 1997. Available on-line from

  18. In Anthony Jameson, Ccile Paris, and Carlo Tasso (Eds.), User Modeling: Proceedings of the Sixth International Con ference, UM97. Vienna, New York: Springer Wien New York. CISM, 1997. Available on-line from http://um.org.

    E-Print Network [OSTI]

    Grasso, Floriana

    International Con­ ference, UM97. Vienna, New York: Springer Wien New York. © CISM, 1997. Available on-line from

  19. Production of Ni-Cr-Ti-natural fibres composite and investigation of mechanical properties

    SciTech Connect (OSTI)

    Pesmen, G.; Erol, A.

    2015-03-30

    Intermetallic materials such as Ni{sub 2}Ti, Cr{sub 2}Ti are among advanced technology materials that have outstanding mechanical and physical properties for high temperature applications. Especially creep resistance, low density and high hardness properties stand out in such intermetallics. The microstructure, mechanical properties of (%50Ni-%48Cr-%2Ti)-%10Naturel Fibres and (%64Ni-%32Cr-%4Ti)-%10Naturel Fibres powders were investigated using specimens produced by tube furnace sintering at 1000-1200-1400°C temperature. A composite consisting of ternary additions, a metallic phase, Ti,Cr and Ni have been prepared under Ar shroud and then tube furnace sintered. XRD, SEM (Scanning Electron Microscope), were investigated to characterize the properties of the specimens. Experimental results carried out for composition (%64Ni-%32Cr-%4Ti)-%10Naturel at 1400°C suggest that the best properties as 112.09HV and 5,422g/cm{sup 3} density were obtained at 1400°C.

  20. Effect of Surface Termination on the Electonic Properties of LaNiO? Films

    SciTech Connect (OSTI)

    Kumah, Divine P.; Malashevich, Andrei; Disa, Ankit S.; Arena, Dario A.; Walker, Fred J.; Ismail-Beigi, Sohrab; Ahn, Charles H.

    2014-11-06

    The electronic and structural properties of thin LaNiO? films grown by using molecular beam epitaxy are studied as a function of the net ionic charge of the surface terminating layer. We demonstrate that electronic transport in nickelate heterostructures can be manipulated through changes in the surface termination due to a strong coupling of the surface electrostatic properties to the structural properties of the Ni—O bonds that govern electronic conduction. We observe experimentally and from first-principles theory an asymmetric response of the structural properties of the films to the sign of the surface charge, which results from a strong interplay between electrostatic and mechanical boundary conditions governing the system. The structural response results in ionic buckling in the near-surface NiO? planes for films terminated with negatively charged NiO? and bulklike NiO? planes for films terminated with positively charged LaO planes. The ability to modify transport properties by the deposition of a single atomic layer can be used as a guiding principle for nanoscale device fabrication.

  1. Effect of Surface Termination on the Electonic Properties of LaNiO? Films

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kumah, Divine P.; Malashevich, Andrei; Disa, Ankit S.; Arena, Dario A.; Walker, Fred J.; Ismail-Beigi, Sohrab; Ahn, Charles H.

    2014-11-06

    The electronic and structural properties of thin LaNiO? films grown by using molecular beam epitaxy are studied as a function of the net ionic charge of the surface terminating layer. We demonstrate that electronic transport in nickelate heterostructures can be manipulated through changes in the surface termination due to a strong coupling of the surface electrostatic properties to the structural properties of the Ni—O bonds that govern electronic conduction. We observe experimentally and from first-principles theory an asymmetric response of the structural properties of the films to the sign of the surface charge, which results from a strong interplay betweenmore »electrostatic and mechanical boundary conditions governing the system. The structural response results in ionic buckling in the near-surface NiO? planes for films terminated with negatively charged NiO? and bulklike NiO? planes for films terminated with positively charged LaO planes. The ability to modify transport properties by the deposition of a single atomic layer can be used as a guiding principle for nanoscale device fabrication.« less

  2. Heavyweight Applications of Lightweight User Models UM 2001 Invited Talk Copyright 2001 Joseph A. Konstan July 16, 2001

    E-Print Network [OSTI]

    Minnesota, University of

    Heavyweight Applications of Lightweight User Models UM 2001 Invited Talk Copyright 2001 Joseph A. Konstan July 16, 2001 UM 2001 1 Heavyweight Applications of Lightweight User Models Collaborative@cs.umn.edu http://www.grouplens.org UM 2001 2 Where We're Going · So much with so little ­ the power

  3. UM,CP Dive Manual Exam Page 1 Rev. 3/15/2012 Diving Safety Diving Manual Exam

    E-Print Network [OSTI]

    Boynton, Walter R.

    UM,CP Dive Manual Exam Page 1 Rev. 3/15/2012 Diving Safety ­ Diving Manual Exam 1. AAUS records of dives equipment inspection and testing records all of the above #12;UM,CP Dive Manual Exam Page 2 Rev. 3/15/2012 8. Before conducting any diving operation under the auspices of the UM,CP

  4. Micro-PIXE measurement of Ni distribution over supported nickel oxide catalyst

    SciTech Connect (OSTI)

    Ahmed, M.; Rahman, A.; Nickel, J. [King Fahd Univ., Dhahran (Saudi Arabia)] [and others

    1994-12-31

    Supported nickel oxide catalysts have a wide range of applications in petrochemical industry. This work reports the results of a micro-PIXE measurement of Ni distribution in a supported nickel oxide catalyst over individual silica base particles, 60-200 {mu}m in size. These catalysts were synthesized with 1% and 5% then calcined at 400 {degrees}C. A 2.5 MeV proton microbeam was used to scan the samples of individual grains. Two dimensional distribution maps of Ni and Si have been measured. This paper discusses the important effects of the process of calcination on the distribution of Ni. The effects of different nickel loading and other synthesis conditions will also be discussed.

  5. Mass Measurements of Proton-Rich Nuclei Fe-50 and Ni-54 

    E-Print Network [OSTI]

    Tribble, Robert E.; Cossairt, J. D.; May, D. P.; Kenefick, R. A.

    1977-01-01

    to different kinematic shifts for the 'He' s from the light (A=12) and heavy (A =54, 58) mass targets. Calibrated 'He spectra from Fe and "Ni are shown in Fig. 1. From previous ('He, 'He) measurements, the cross sections to "Fe and ' Ni were expected... are TABLE I. Properties of Fe and 5 Ni. All entries are in MeV. Nuclide Expt. Mass excess Garvey and Kelson ~ Coulomb energy ~ip ~2p Coulomb energy 50Fe -34.48 +0.06 -39.21 +0.05 -34.50 39.27 -34.472 +0.013 -39.296 +0.013 4.16 6.24 8.93 +0.06 3...

  6. Surface roughness and interface width scaling of magnetron sputter deposited Ni/Ti multilayers

    SciTech Connect (OSTI)

    Maidul Haque, S.; Biswas, A.; Tokas, R. B.; Bhattacharyya, D.; Sahoo, N. K.; Bhattacharya, Debarati

    2013-09-14

    Using an indigenously built r.f. magnetron sputtering system, several single layer Ti and Ni films have been deposited at varying deposition conditions. All the samples have been characterized by Grazing Incidence X-ray Reflectivity (GIXR) and Atomic Force Microscopy to estimate their thickness, density, and roughness and a power law dependence of the surface roughness on the film thickness has been established. Subsequently, at optimized deposition condition of Ti and Ni, four Ni/Ti multilayers of 11-layer, 21-layer, 31-layer, and 51-layer having different bilayer thickness have been deposited. The multilayer samples have been characterized by GIXR and neutron reflectivity measurements and the experimental data have been fitted assuming an appropriate sample structure. A power law correlation between the interface width and bilayer thickness has been observed for the multilayer samples, which was explained in the light of alternate roughening/smoothening of multilayers and assuming that at the interface the growth “restarts” every time.

  7. Desenvolvimento de um Sistema para Anlise da Variabilidade da Freqncia Cardaca

    E-Print Network [OSTI]

    Carvalho, João Luiz

    sinal de HRV utilizando um algoritmo de detecção automática dos complexos QRS. O usuário pode de HRV. Existem programas que implementam alguns dos algoritmos disponíveis, mas não todos eles

  8. Um Sistema Computacional integrando Suporte `a Decis~ao na Area de Reproduc ~ao Humana

    E-Print Network [OSTI]

    Baranauskas, José Augusto

    desenvolvimento de um sistema computacional que a implementa. Tais elementos permitem informatizar os processos e¸ ~ao. Palavras-chaves: Reproduc¸ ~ao Assistida, Sistemas de Suporte `a Decis~ao, Aprendizado de M´aquina

  9. Characterization and corrosion behaviour of CoNi alloys obtained by mechanical alloying

    SciTech Connect (OSTI)

    Olvera, S. [Instituto Politécnico Nacional, ESIQIE, Departamento de Ingeniería en Metalurgia y Materiales, México, D. F. (Mexico); Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química-Física Aplicada, 28049 Madrid (Spain); Sánchez-Marcos, J. [Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química-Física Aplicada, 28049 Madrid (Spain); Palomares, F.J. [Instituto de Ciencia de Materiales de Madrid, ICMM-CSIC, Cantoblanco, 28049 Madrid (Spain); Salas, E. [Spline Spanish CRG Beamline at the European Synchrotron Radiation Facilities, ESRF, BP 220-38043, Grenoble Cedex (France); Arce, E.M. [Instituto Politécnico Nacional, ESIQIE, Departamento de Ingeniería en Metalurgia y Materiales, México, D. F. (Mexico); Herrasti, P., E-mail: pilar.herrasti@uam.es [Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química-Física Aplicada, 28049 Madrid (Spain)

    2014-07-01

    CoNi alloys including Co{sub 30}Ni{sub 70}, Co{sub 50}Ni{sub 50} and Co{sub 70}Ni{sub 30} were prepared via mechanical alloying using Co and Ni powders. The crystallinity and short-range order were studied using X-ray diffraction and X-ray absorption spectroscopy. The results show that the milling process increases the number of vacancies, especially around the Co atoms, while the milling time decreases the crystalline size and enhances the crystallinity. X-ray photoelectron spectroscopy was used to characterise the chemical composition of the samples surface. The magnetic properties were analysed using zero-field cooling, field cooling and a magnetic hysteresis loops. The magnetic saturation moment is approximately 1.05 ?{sub B}/atom; this value decreases with the mechanical alloying time, and it is proportional to the cobalt concentration. The polarization and impedance curves in different media (NaCl, H{sub 2}SO{sub 4} and NaOH) showed similar corrosion resistance values. The corrosion resistance increased in the order NaCl, H{sub 2}SO{sub 4} and NaOH. A good passivation layer was formed in NaOH due to the cobalt and nickel oxides on the particle surfaces. - Highlights: • Ni{sub x}Co{sub 100-x} alloys were synthesized by mechanical alloying • Milling time decrease size and enhances crystallinity. • Oxygen is not present in a significant percentage in bulk but is detected on the surface. • Magnetic saturation moment is 1.05 mB/atom and decrease with mechanical allowing time • Corrosion resistance is higher in NaOH than in NaCl or HCl solutions.

  10. [TiII] and [NiII] emission from the strontium filament of eta Carinae

    E-Print Network [OSTI]

    M. A. Bautista; H. Hartman; T. R. Gull; N. Smith; K. Lodders

    2006-06-12

    We study the nature of the [TiII] and [NiII] emission from the so-called strontium filament found in the ejecta of eta Carinae. To this purpose we employ multilevel models of the TiII and NiII systems which are used to investigate the physical condition of the filament and the excitation mechanisms of the observed lines. For the TiII ion, for which no atomic data was previously available, we carry out ab initio calculations of radiative transition rates and electron impact excitation rate coefficients. It is found that the observed spectrum is consistent with the lines being excited in a mostly neutral region with an electron density of the order of $10^7$ cm$^{-3}$ and a temperature around 6000 K. In analyzing three observations with different slit orientations recorded between March~2000 and November~2001 we find line ratios that change among various observations, in a way consistent with changes of up to an order of magnitude in the strength of the continuum radiation field. These changes result from different samplings of the extended filament, due to the different slit orientations used for each observation, and yield clues on the spatial extent and optical depth of the filament. The observed emission indicates a large Ti/Ni abundance ratio relative to solar abundances. It is suggested that the observed high Ti/Ni ratio in gas is caused by dust-gas fractionation processes and does not reflect the absolute Ti/Ni ratio in the ejecta of \\etacar. We study the condensation chemistry of Ti, Ni and Fe within the filament and suggest that the observed gas phase overabundance of Ti

  11. Preparation and characterization of nanodiamond cores coated with a thin Ni-Zn-P alloy film

    SciTech Connect (OSTI)

    Wang Rui; Ye Weichun; Ma Chuanli; Wang Chunming

    2008-02-15

    Nanodiamond cores coated with a thin Ni-Zn-P alloy film were prepared by an electroless deposition method under the conditions of tin chloride sensitization and palladium chloride activation. The prepared materials were analyzed by Fourier transform infrared (FTIR) spectrometry and X-ray diffraction (XRD). The nanostructure of the materials was then characterized by transmission electron microscopy (TEM). The alloy film composition was characterized by Energy Dispersive X-ray (EDX) analysis. The results indicated the approximate composition 49.84%Ni-37.29%Zn-12.88%P was obtained.

  12. KADoNiS-$p$: The astrophysical $p$-process database

    E-Print Network [OSTI]

    T. Szücs; I. Dillmann; R. Plag; Zs. Fülöp

    2015-03-02

    The KADoNiS-$p$ project is an online database for cross sections relevant to the $p$-process. All existing experimental data was collected and reviewed. With this contribution a user-friendly database using the KADoNiS (Karlsruhe Astrophysical Database of Nucleosynthesis in Stars) framework is launched, including all available experimental data from (p,$\\gamma$), (p,n), (p,$\\alpha$), ($\\alpha$,$\\gamma$), ($\\alpha$,n) and ($\\alpha$,p) reactions in or close to the respective Gamow window with cut-off date of August 2012 (www.kadonis.org/pprocess).

  13. Contact-induced spin polarization in BNNT(CNT)/TM (TM=Co, Ni) nanocomposites

    SciTech Connect (OSTI)

    Kuzubov, Alexander A.; Kovaleva, Evgenia A. Avramov, Paul; Kuklin, Artem V.; Mikhaleva, Natalya S.; Tomilin, Felix N.; Sakai, Seiji; Entani, Shiro; Matsumoto, Yoshihiro; Naramoto, Hiroshi

    2014-08-28

    The interaction between carbon and BN nanotubes (NT) and transition metal Co and Ni supports was studied using electronic structure calculations. Several configurations of interfaces were considered, and the most stable ones were used for electronic structure analysis. All NT/Co interfaces were found to be more energetically favorable than NT/Ni, and conductive carbon nanotubes demonstrate slightly stronger bonding than semiconducting ones. The presence of contact-induced spin polarization was established for all nanocomposites. It was found that the contact-induced polarization of BNNT leads to the appearance of local conductivity in the vicinity of the interface while the rest of the nanotube lattice remains to be insulating.

  14. Surface segregation effects in electrocatalysis: Kinetics ofoxygen reduction reaction on polycrystalline Pt3Ni alloy surfaces

    SciTech Connect (OSTI)

    Stamenkovic, V.; Schmidt, T.J.; Ross, P.N.; Markovic, N.M.

    2002-11-01

    Effects of surface segregation on the oxygen reduction reaction (ORR) have been studied on a polycrystalline Pt3Ni alloy in acid electrolyte using ultra high vacuum (UHV) surface sensitive probes and the rotating ring disk electrode (RRDE) method. Preparation, modification and characterization of alloy surfaces were done in ultra high vacuum (UHV). Depending on the preparation method, two different surface compositions of the Pt3Ni alloy are produced: a sputtered surface with 75 % Pt and an annealed surface (950 K ) with 100 % Pt. The latter surface is designated as the 'Pt-skin' structure, and is a consequence of surface segregation, i.e., replacement of Ni with Pt atoms in the first few atomic layers. Definitive surface compositions were established by low energy ion scattering spectroscopy (LEISS). The cyclic voltammetry of the 'Pt-skin' surface as well as the pseudocapacitance in the hydrogen adsorption/desorption potential region is similar to a polycrystalline Pt electrode. Activities of ORR on Pt3Ni alloy surfaces were compared to polycrystalline Pt in 0.1M HClO4 electrolyte for the observed temperature range of 293 < T < 333 K. The order of activities at 333 K was: 'Pt-skin' > Pt3Ni (75% Pt) > Pt with the maximum catalytic enhancement obtained for the 'Pt-skin' being 4 times that for pure Pt. Catalytic improvement of the ORR on Pt3Ni and 'Pt-skin' surfaces was assigned to the inhibition of Pt-OHad formation (on Pt sites) versus polycrystalline Pt. Production of H2O2 on both surfaces were similar compared to the pure Pt. Kinetic analyses of RRDE data confirmed that kinetic parameters for the ORR on the Pt3Ni and 'Pt-skin' surfaces are the same as on pure Pt: reaction order, m=1, two identical Tafel slopes, activation energy, {approx} 21-25 kJ/mol. Therefore the reaction mechanism on both Pt3Ni and 'Pt-skin' surfaces is the same as one proposed for pure Pt i.e. 4e{sup -} reduction pathway.

  15. Electrical characteristics of Ni Ohmic contact on n-type GeSn

    SciTech Connect (OSTI)

    Li, H.; Cheng, H. H., E-mail: hhcheng@ntu.edu.tw [Center for Condensed Matter Sciences and Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 106, Taiwan (China); Lee, L. C.; Lee, C. P. [Center for Nano Science and Technology, National Chiao Tung University, Hsinchu 300, Taiwan (China); Su, L. H.; Suen, Y. W. [Department of Physics and Institute of Nano Science, National Chung Hsing University, Taichung 402, Taiwan (China)

    2014-06-16

    We report an investigation of the electrical and material characteristics of Ni on an n-type GeSn film under thermal annealing. The current-voltage traces measured with the transmission line method are linear for a wide range of annealing temperatures. The specific contact resistivity was found to decrease with increasing annealing temperature, followed by an increase as the annealing temperature further increased, with a minimum value at an annealing temperature of 350?°C. The material characteristics at the interface layer were measured by energy-dispersive spectrometer, showing that an atomic ratio of (Ni)/(GeSn)?=?1:1 yields the lowest specific contact resistivity.

  16. Na, Mg, Ni and Cs distribution and speciation after long-term alteration of a simulated nuclear waste glass

    E-Print Network [OSTI]

    Farges b,c , Marika Vespa a,1 a Laboratory for Waste Management, Paul Scherrer Institut, CH-5232 Villigen distribution and speciation of Na, Mg, Ni and Cs in a simulated (inactive) nuclear waste glass were studied and Cs represent dose determining long-lived radionuclides (59 Ni, 135 Cs) in vitrified nuclear waste

  17. Young's modulus of electroplated Ni thin film for MEMS applications J.K. Luoa,*, A.J. Flewitta

    E-Print Network [OSTI]

    Fleck, Norman A.

    to a less dense coating. D 2004 Elsevier B.V. All rights reserved. Keywords: Young's modulus; ElectroplatedYoung's modulus of electroplated Ni thin film for MEMS applications J.K. Luoa,*, A.J. Flewitta , S online 28 April 2004 Abstract The Young's modulus of an electroplated nickel (Ni) thin film suitable

  18. The NiCE Discussion Room: Integrating Paper and Digital Media to Support Co-Located Group Meetings

    E-Print Network [OSTI]

    -based interfaces, multi-user input, digital meeting room, design ACM Classification Keywords H5.3. GroupThe NiCE Discussion Room: Integrating Paper and Digital Media to Support Co-Located Group Meetings or replicate. We introduce a novel digital meeting room design, the NiCE Discussion Room, which integrates

  19. Structural model for the Al72Ni20Co8 decagonal quasicrystals National Renewable Energy Laboratory, Golden, Colorado 80401

    E-Print Network [OSTI]

    Pennycook, Steve

    Structural model for the Al72Ni20Co8 decagonal quasicrystals Yanfa Yan National Renewable Energy, Oak Ridge, Tennessee 37831 Received 15 February 2000 We propose a structure model for the Al72Ni20Co8 structural models have been proposed for de- cagonal quasicrystals based upon x-ray and neutron diffrac- tion

  20. Growth, crystalline structure and magnetic properties of ultrathin alloy lms CoxNi1x/Cu(1 0 0)

    E-Print Network [OSTI]

    Lin, Minn-Tsong

    Growth, crystalline structure and magnetic properties of ultrathin alloy ®lms CoxNi1Àx/Cu(1 0 0) W 2001 Abstract Magnetic ultrathin alloy ®lms CoxNi1Àx/Cu(1 0 0) were prepared to characterize diraction oscillation and Auger electron spectroscopy, the composition of the alloy ®lms was controlled

  1. 1600 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 22, NO. 5, SEPTEMBER 2007 Solar Battery Chargers for NiMH Batteries

    E-Print Network [OSTI]

    Lehman, Brad

    1600 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 22, NO. 5, SEPTEMBER 2007 Solar Battery Chargers for NiMH Batteries Florent Boico, Brad Lehman, Member, IEEE, and Khalil Shujaee Abstract--This paper proposes new solar battery chargers for NiMH batteries. First, it is shown that existing charge

  2. Z .Surface and Coatings Technology 130 2000 164 172 Production of high-density Ni-bonded tungsten carbide

    E-Print Network [OSTI]

    Ghoniem, Nasr M.

    Z .Surface and Coatings Technology 130 2000 164 172 Production of high-density Ni-bonded tungsten carbide coatings using an axially fed DC-plasmatron S. Sharafata,U , A. Kobayashib , S. Chena , N of high-density Ni WC coatings were produces with uniform distribution of WC particles. The small powder

  3. 3D Microstructure of Ni-YSZ anodes: Prediction of effective transport properties and optimization of redox stability

    E-Print Network [OSTI]

    Schmidt, Volker

    3D Microstructure of Ni-YSZ anodes: Prediction of effective transport properties and optimization a fuel (e.g. natural gas, biogas, H2). The advantages of SOFCs are a high efficiency, fuel flexibility). The electrochemical performance of Ni-YSZ anodes depends on the interplay between different transport processes

  4. Hydrogen dissociation and diffusion on Ni-and Ti-doped Mg,,0001... M. Pozzo,1,2

    E-Print Network [OSTI]

    Alfè, Dario

    Hydrogen dissociation and diffusion on Ni- and Ti-doped Mg,,0001... surfaces M. Pozzo,1,2 D. Alfè,1 functional theory investigation of hydrogen dissociation and surface diffusion over a Ni-doped surface show that the energy barrier for hydrogen dissociation on the pure Mg 0001 surface is high, while

  5. Thermal Expansion, Heat Capacity, and Thermal Conductivity of Nickel Ferrite (NiFe[subscript 2]O[subscript 4])

    E-Print Network [OSTI]

    Nelson, Andrew T.

    Nickel ferrite (NiFe[subscript 2]O[subscript 4]) is a major constituent of the corrosion deposits formed on the exterior of nuclear fuel cladding tubes during operation. NiFe[subscript 2]O[subscript 4] has attracted much ...

  6. Experimental study of the FeNiTi system L.I. Duarte a,b,*, U.E. Klotz a,1

    E-Print Network [OSTI]

    Giger, Christine

    system, which is relevant for many different materials such as steels, Ni-based superalloys, alloyed a mixture of Ni and Ti powders on an iron substrate and annealing at 1100, 1200 and 1250 C for 5­120 min

  7. UMS attainment at AS-level of applicants, by subject and offer status The graphs show the profile of our 2014 gathered field banded by their average UMS

    E-Print Network [OSTI]

    UMS attainment at AS-level of applicants, by subject and offer status The graphs show the profile and differentiating those who received offers from the rest of the field. For the sciences courses other than can produce some odd looking profiles by percentages receiving offers based on very small numbers

  8. In situ sulfiding of Ni-W hydrocracking catalysts : differentiation of different preparation procedures using EXAFS and HRTEM.

    SciTech Connect (OSTI)

    Kelly, S. D.; Yang, N.; Mickelson, G. E.; Greenlay, N.; Karapetrova, E.; Sinkler, W.; Bare, S. R.; UOP LLC; EXAFS Analysis

    2009-01-01

    The detailed structural characterization of the metal function of two fully formulated Ni-W hydrocracking catalysts was investigated by time resolved in situ X-ray absorption spectroscopy (EXAFS and XANES) at both the Ni K-edge and W L{sub 3}-edge, and by high resolution transmission electron microscopy. These two hydrocracking catalysts (designated as HCA and HCB) contained the same wt% of Ni and W, the same wt% of the other constituents ({gamma}-Al{sub 2}O{sub 3}/silico-aluminate), and were calcined at the same temperature, but were prepared by different methods in order to highlight the sensitivity of the characterization techniques to the structural differences. The morphology of the WS{sub 2} particles in the sulfided catalyst is substantially different between the two catalysts: in the HCA catalyst there are many more particles with multiple WS{sub 2} layers whereas in HCB there are more single layers. The average diameter of the WS{sub 2} plates is similar in both. The catalysts show a difference in the amount of W sulfidation after the 410 C sulfidation treatment in 10% H{sub 2}S/H{sub 2}. The W of HCA catalyst was completely sulfided whereas 16% W of HCB catalyst was unsulfided. Similarly there is a difference in the amount of sulfided Ni: 16% Ni in HCA and 60% Ni in HCB remain unsulfided. In the sulfided form of both catalysts the Ni exists in three different morphologies: oxidized Ni (six-fold coordinate as a nickel aluminate), nanoparticulate Ni{sub 3}S{sub 2}, and Ni decorating the edge sites of the WS{sub 2}. In both the Ni{sub 3}S{sub 2}, and Ni decorating the edge sites of the WS{sub 2}, the Ni is in a tetrahedral coordination with sulfur. In both catalysts the sulfidation of the Ni and W occurs essentially simultaneously over most of the temperature range and the sulfidation of the W proceeds through the same tungsten oxysulfide in both samples. The characterization methodology presented here is a powerful one for elucidating the structural differences of complex heterogeneous catalysts.

  9. Microstructures and Mechanical Properties of Compositionally Complex Co-free FeNiMnCr18 FCC Solid Solution Alloy

    SciTech Connect (OSTI)

    Wu, Zhenggang [The University of Tennessee; Bei, Hongbin [ORNL

    2015-01-01

    Recently,a structurally-simplebutcompositionally-complex FeNiCoMnCr highentropyalloywasfoundto haveexcellentmechanicalproperties(e.g.,highstrengthandductility).Tounderstandthepotentialof using highentropyalloysasstructuralmaterialsforadvancednuclearreactorandpowerplants,itis necessary tohaveathoroughunderstandingoftheirstructuralstabilityandmechanicalpropertiesde- gradation underneutronirradiation.ThisrequiresustodevelopasimilarmodelalloywithoutCobe- cause materialwithCowillmakepost-neutron-irradiationtestingdifficult duetotheproductionofthe 60Co radioisotope.Toachievethisgoal,aFCC-structuredsingle-phasealloywithacompositionof FeNiMnCr18 wassuccessfullydeveloped.Thisnear-equiatomicFeNiMnCr18 alloy hasgoodmalleability and itsmicrostructurecanbecontrolledbythermomechanicalprocessing.Byrollingandannealing,the as-cast elongated-grained-microstructureisreplacedbyhomogeneousequiaxedgrains.Themechanical properties (e.g.,strengthandductility)oftheFeNiMnCr18 alloy arecomparabletothoseoftheequiatomic FeNiCoMnCr highentropyalloy.Bothstrengthandductilityincreasewithdecreasingdeformation temperature,withthelargestdifferenceoccurringbetween293and77K.Extensivetwin-bandswhich are bundlesofnumerousindividualtwinsareobservedwhenitistensile-fracturedat77K.Notwin bands aredetectedbyEBSDformaterialsdeformedat293Kandhigher.Theunusualtemperature-de- pendencies ofUTSanduniformelongationcouldbecausedbythedevelopmentofthedensetwin substructure, twin-dislocationinteractionsandtheinteractionsbetweenprimaryandsecondarytwin- ning systemswhichresultinamicrostructurerefinement andhencecauseenhancedstrainhardening and postponednecking.

  10. Induced spin-polarization of EuS at room temperature in Ni/EuS multilayers

    SciTech Connect (OSTI)

    Poulopoulos, P.; Goschew, A.; Straub, A.; Fumagalli, P.; Kapaklis, V.; Wolff, M.; Delimitis, A.; Wilhelm, F.; Rogalev, A.; Pappas, S. D.

    2014-03-17

    Ni/EuS multilayers with excellent multilayer sequencing are deposited via e-beam evaporation on the native oxide of Si(100) wafers at 4?×?10{sup ?9} millibars. The samples have very small surface and interface roughness and show sharp interfaces. Ni layers are nanocrystalline 4–8?nm thick and EuS layers are 2–4?nm thick and are either amorphous or nanocrystalline. Unlike for Co/EuS multilayers, all Eu ions are in divalent (ferromagnetic) state. We show a direct antiferromagnetic coupling between EuS and Ni layers. At room temperature, the EuS layers are spin-polarized due to the proximity of Ni. Therefore, Ni/EuS is a candidate for room-temperature spintronics applications.

  11. X-ray absorption fine structure (XAFS) analyses of Ni species trapped in graphene sheet of carbon nanofibers

    SciTech Connect (OSTI)

    Ushiro, Mayuko; Uno, Kanae; Fujikawa, Takashi; Sato, Yoshinori; Tohji, Kazuyuki; Watari, Fumio; Chun, W.-J.; Koike, Yuichiro; Asakura, Kiyotaka

    2006-04-01

    Metal impurities in the carbon nanotubes and carbon nanofibers play an important role in understanding their physical and chemical properties. We apply the Ni K-edge x-ray absorption fine structure analyses to the local electronic and geometric structures around embedded Ni impurities used as catalysts in a carbon nanofiber in combination with multiple scattering analyses. We find almost Ni catalysts as metal particles are removed by the purification treatment. Even after the purification, residual 100 ppm Ni species are still absorbed; most of them are in monomer structure with Ni-C bond length 1.83 A, and each of them is substituted for a carbon atom in a graphene sheet.

  12. Effect of annealing temperature on the contact properties of Ni/V/4H-SiC structure

    SciTech Connect (OSTI)

    Dai, Chong-Chong; Zhou, Tian-Yu; University of Chinese Academy of Sciences, Beijing 100049 ; Liu, Xue-Chao Zhuo, Shi-Yi; Kong, Hai-Kuan; Yang, Jian-Hua; Shi, Er-Wei

    2014-04-15

    A sandwich structure of Ni/V/4H-SiC was prepared and annealed at different temperatures from 650?°C to 1050?°C. The electrical properties and microstructures were characterized by transmission line method, X-ray diffraction, Raman spectroscopy and transmission electron microscopy. A low specific contact resistance of 3.3 × 10{sup -5} ?·cm{sup 2} was obtained when the Ni/V contact was annealed at 1050?°C for 2 min. It was found that the silicide changed from Ni{sub 3}Si to Ni{sub 2}Si with increasing annealing temperature, while the vanadium compounds appeared at 950?°C and their concentration increased at higher annealing temperature. A schematic diagram was proposed to explain the ohmic contact mechanism of Ni/V/4H-SiC structure.

  13. Molecular oxygen adsorbates at a Au/Ni(111) surface alloy and their role in catalytic CO oxidation at 70 - 250 K

    E-Print Network [OSTI]

    Lahr, David Louis

    2006-01-01

    Oxygen is observed to adsorb molecularly on 0.13 - 0.27 ML Au/Ni(1 111) surface alloys at 77 K, in stark contrast to dissociative adsorption on Ni and no adsorption on Au surfaces. Molecular 02 adsorbates on the Au/Ni(111) ...

  14. Optical spectroscopy of jet-cooled NiSi Ned F. Lindholm, Dale J. Brugh, Gretchen K. Rothschopf, Shane M. Sickafoose,

    E-Print Network [OSTI]

    Morse, Michael D.

    -power microwave circuitry,4 anode mate- rial in lithium batteries, and development of ULSI circuitry.5 Because was determined to be D0(NiSi) 3.26 0.18 eV us- ing the reaction Ni g Si2C g C graphite NiSi g SiC2 g . Several

  15. Adsorption of a carbon atom on the Ni38 magic cluster and three low-index nickel surfaces: A comparative first-principles study

    E-Print Network [OSTI]

    Gong, Xingao

    Adsorption of a carbon atom on the Ni38 magic cluster and three low-index nickel surfaces in the catalytic growth of carbon C nanotubes on clusters of transition metal catalysts. Here we focus by studying a C atom on a nickel Ni magic cluster (Ni38), which preserves fcc geometry, and three low

  16. THE KINETICS OF THE 02/C02 REACTION IN MOLTEN CARBONATE: REACTION ORDERS FOR 02 AND CO2 ON NiO

    E-Print Network [OSTI]

    Winnick, Jack

    2011-01-01

    ORDERS FOR 0 2 AND C0 2 ON NiO Jack Winnick and Philip N.REACTION ORDERS FOR 0 AND C0 ON NiO Jack Winnick Depar·tmentversion of the electrodes to NiO. Measurements were made

  17. Combustion synthesis/quasi-isostatic pressing of TiC0.7NiTi cermets: microstructure and transformation characteristics

    E-Print Network [OSTI]

    Meyers, Marc A.

    Combustion synthesis/quasi-isostatic pressing of TiC0.7­NiTi cermets: microstructure Abstract TiC0.7­NiTi cermets were produced by com- bustion synthesis followed by quasi-isostatic consolidation while the reaction products were still hot and ductile. The TiC0.7­NiTi cermets were characterized

  18. Monitoring the hydration of cement using highly nonlinear solitary waves Xianglei Ni a

    E-Print Network [OSTI]

    Daraio, Chiara

    Monitoring the hydration of cement using highly nonlinear solitary waves Xianglei Ni Available online 22 May 2012 Keywords: Highly nonlinear solitary waves Cement Hydration Nondestructive on the propagation of highly nonlinear solitary waves (HNSWs) to monitor the hydration of cement. HNSWs

  19. Surface characteristics and corrosion resistance properties of TiNi shape memory alloy coated with Ta

    E-Print Network [OSTI]

    Zheng, Yufeng

    for electroplated, crimped, or swaged metal bands that can be abrasive, loosen, crack, or fall off. For coatingSurface characteristics and corrosion resistance properties of TiNi shape memory alloy coated coated with tantalum by the arc ion plating method with the aim to improve their radiopacity. Surface

  20. YouTubeEvent: on Large-Scale Video Event Classification Bingbing Ni

    E-Print Network [OSTI]

    Cortes, Corinna

    YouTubeEvent: on Large-Scale Video Event Classification Bingbing Ni Advanced Digital Sciences the problem of general event classification from uncontrolled YouTube videos. It is a challenging task due from YouTube to represent these categories. To improve classification per- formance, video content

  1. The importance of 56Ni in shaping the light curves of type II supernovae

    E-Print Network [OSTI]

    Nakar, Ehud; Katz, Boaz

    2015-01-01

    What intrinsic properties shape the light curves of Type II supernovae (SNe)? To address this question we derive observational measures that are robust (i.e., insensitive to detailed radiative transfer) and constrain the contribution from 56Ni, as well as a combination of the ejecta mass, progenitor radius, and explosion energy. By applying our methods to a sample of type II SNe from the literature we find that 56Ni contribution is often significant. It is typically the source of about 20% of the radiated energy during the photospheric phase, and in extreme cases it even dominates. We find that the 56Ni relative contribution is anti-correlated with the luminosity decline rate, while it is not significantly correlated with other properties of the light curve. When added to other clues, this in turn suggests that the flat plateaus often observed in type II SNe are not a generic feature of the cooling envelope emission, and that without 56Ni many of the SNe that are classified as II-P would have shown a decline ...

  2. Grain size dependence of fracture toughness and crack-growth resistance of superelastic NiTi

    E-Print Network [OSTI]

    Sun, Qing-Ping

    Available online xxxx Keywords: Shape memory alloys Martensitic phase transformation Microstructure to a reversible martensitic phase transformation (PT), superelastic (SE) NiTi shape memory alloys (SMAs with thickness of 1.7 mm were sandwiched in stainless steel sheets and were cold-rolled to 42% of thickness

  3. Factors Affecting Ni and Zn Hydroxide Precipitate Formation in Soils. (S02-peltier222185-oral)

    E-Print Network [OSTI]

    Sparks, Donald L.

    Factors Affecting Ni and Zn Hydroxide Precipitate Formation in Soils. (S02-peltier222185-oral) Authors: E.F. Peltier* - Univ. of Delaware D.L. Sparks - Univ. of Delaware Abstract: The formation matter in the soil. Speaker Information: Edward Peltier, Univ. of Delaware, Dept. of Plant and Soil

  4. Melting and crystallization in Ni nanoclusters: The mesoscale regime Yue Qi and Tahir C agin

    E-Print Network [OSTI]

    Goddard III, William A.

    Melting and crystallization in Ni nanoclusters: The mesoscale regime Yue Qi and Tahir C¸ agin to a mesoscale nanocrystal regime well-defined bulk and surface properties above 750 atoms 2.7 nm . We find that the mesoscale nanocrystals melt via surface processes, leading to Tm,N Tm,bulk N 1/3 , dropping from Tm

  5. Kinetics of Mixed Ni-Al Precipitate Formation on a Soil Clay Fraction

    E-Print Network [OSTI]

    Sparks, Donald L.

    , industrial waste disposal, atmospheric deposition, and application of fertilizers and pesticides (1 and Soil Sciences, University of Delaware, 147 Townsend Hall, Newark, Delaware 19717-1303, and Waste Management Laboratory, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland The kinetics of mixed Ni

  6. Tantalum coated NiTi alloy by PIIID for biomedical application Y. Zhou a,b

    E-Print Network [OSTI]

    Zheng, Yufeng

    by electrodeposition [14], magnetron sputtering [15], plasma immersion ion implantation (PIII) [16,17] and multi-arc November 2012 Keywords: PIIID Ta coating Corrosion resistance NiTi Plasma immersion ion implantation technique combines the advantages of plasma immer- sion ion implantation (PIII) and magnetron deposition

  7. Constraints on explosive silicon burning in core-collapse supernovae from measured Ni/Fe ratios

    E-Print Network [OSTI]

    Jerkstrand, A; Magkotsios, G; Sim, S A; Fransson, C; Spyromilio, J; Heger, A; Müller, B; Sollerman, J; Smartt, S J

    2015-01-01

    Measurements of explosive nucleosynthesis yields in core-collapse supernovae provide tests for explosion models. We investigate constraints on explosive conditions derivable from measured amounts of nickel and iron after radioactive decays using nucleosynthesis networks with parameterized thermodynamic trajectories. The Ni/Fe ratio is for most regimes dominated by the production ratio of 58Ni/(54Fe + 56Ni), which tends to grow with higher neutron excess and with higher entropy. For SN 2012ec, a supernova that produced a Ni/Fe ratio of $3.4\\pm1.2$ times solar, we find that burning of a fuel with neutron excess $\\eta \\approx 6\\times 10^{-3}$ is required. Unless the progenitor metallicity is over 5 times solar, the only layer in the progenitor with such a neutron excess is the silicon shell. Supernovae producing large amounts of stable nickel thus suggest that this deep-lying layer can be, at least partially, ejected in the explosion. We find that common spherically symmetric models of $M_{\\rm ZAMS} \\lesssim 13$...

  8. Theoretical study of the photoelectron spectrum of (n5-C5H5)Ni(NO) 

    E-Print Network [OSTI]

    Miller, Thomas F.

    2013-02-22

    The valence photoelectron spectrum of cyclopentadienyl nickel nitrosyl (CpNiNO) was computed to determine the ion state orbital ordering of the 5e1, 7a1, and 3e2 bands. Calculations were performed with Hartree-Fock theory, density functional theory...

  9. Ni3Al-based alloys for die and tool application

    DOE Patents [OSTI]

    Liu, Chain T. (Oak Ridge, TN); Bloom, Everett E. (Kingston, TN)

    2001-01-01

    A novel Ni.sub.3 Al-based alloy exhibits strengths and hardness in excess of the standard base alloy IC-221M at temperatures of up to about 1000.degree. C. The alloy is useful in tool and die applications requiring such temperatures, and for structural elements in engineering systems exposed to such temperatures.

  10. ORIGINAL ARTICLES Silica-Supported AuNi Catalysts for the Dehydrogenation

    E-Print Network [OSTI]

    Goodman, Wayne

    Introduction Gold­nickel bimetallic catalysts have shown enhanced catalytic properties for a number of reactions [1­9], such as steaming reforming of hydrocarbons [1, 2], the water­gas shift reaction [3 reforming of n-butane, whereas a monometallic Ni catalyst deactivated rapidly [1]. For the water­gas shift

  11. A first principles study of CH 3 dehydrogenation on Ni(111) A. Michaelides and P. Hu

    E-Print Network [OSTI]

    Alavi, Ali

    step in funda- mental catalytic processes such as steam reforming and methanation. It is also); 10.1063/1.3297885 The internal energy of CO 2 produced by the catalytic oxidation of CH 3 OH by O 2 on Ni 111 , a crucial step in many important catalytic reactions. The reaction, CH3 ads CH2 ads H ads

  12. Evolution of microstructures inside the Ni-YSZ anode of a solid oxide fuel cell

    E-Print Network [OSTI]

    Petta, Jason

    Evolution of microstructures inside the Ni-YSZ anode of a solid oxide fuel cell Jeff Lillibridge Department of Mechanical & Aerospace Engineering Advisor: Mikko Haataja #12;What is a solid oxide fuel cell microstructuralcoarsening processes to electrochemical performancein solid oxide fuel cells: An integrated modeling approach

  13. THE LINK BETWEEN CLAY MINERAL WEATHERING AND THE FORMATION OF NI SURFACE PRECIPITATES

    E-Print Network [OSTI]

    Sparks, Donald L.

    THE LINK BETWEEN CLAY MINERAL WEATHERING AND THE FORMATION OF NI SURFACE PRECIPITATES Andreas C minerals may proceed via formation of surface precipitates, which may lead to a significant long the formation of several mineral phases with distinct solubilities. While turbostratic a-type metal hydroxides

  14. Ni.sub.3 Al-based intermetallic alloys having improved strength above 850.degree. C.

    DOE Patents [OSTI]

    Liu, Chain T. (Oak Ridge, TN)

    2000-01-01

    Intermetallic alloys composed essentially of: 15.5% to 17.0% Al, 3.5% to 5.5% Mo, 4% to 8% Cr, 0.04% to 0.2% Zr, 0.04% to 1.5% B, balance Ni, are characterized by melting points above 1200.degree. C. and superior strengths at temperatures above 1000.degree. C.

  15. Assessing the Bioavailability of Ni in Smelter Contaminated Soils. (S11-everhart242852-oral)

    E-Print Network [OSTI]

    Sparks, Donald L.

    Assessing the Bioavailability of Ni in Smelter Contaminated Soils. (S11-everhart242852-oral contaminants in soil environments derived from industrial pollution have clearly established the need in soils. However, there is still a need to better understand the availability of metal contaminants

  16. Structural aspects of glass-formation in Ni-Nb melts

    SciTech Connect (OSTI)

    Holland-Moritz, D.; Yang, F.; Gegner, J.; Meyer, A. [Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), 51170 Köln (Germany); Hansen, T. [Institut Laue-Langevin (ILL), 38042 Grenoble (France); Ruiz-Martín, M. D. [Grup de Caracterització de Materials, Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Barcelona (Spain); Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), 51170 Köln (Germany)

    2014-05-28

    We report on investigations of the static structure factors of glass-forming Ni{sub 59.5}Nb{sub 40.5} alloy melts by combination of the containerless processing technique of electrostatic levitation with neutron diffraction. By application of the isotopic substitution method, the full set of partial structure factors was determined. The short-range order in liquid Ni{sub 59.5}Nb{sub 40.5} is characterized by a large nearest neighbor coordination number of Z{sub NN}?=?14.3 and a chemical short-range order with an affinity for the formation of heterogeneous Nb-Ni nearest neighbors. The structure factors observed here in the liquid state closely resemble those reported for amorphous Nb-Ni solids. The comparison with earlier results on the short-range structure in Zr-based glass-forming melts suggests that a large local density of packing, chemical order, and structural frustration are, amongst others, common structural properties of these metallic glass-forming systems, which favor glass-formation.

  17. Aliovalent titanium substitution in layered mixed Li Ni-Mn-Co oxides for lithium battery applications

    SciTech Connect (OSTI)

    Kam, Kinson; Doeff, Marca M.

    2010-12-01

    Improved electrochemical characteristics are observed for Li[Ni1/3Co1/3-yMyMn1/3]O2 cathode materials when M=Ti and y<0.07, compared to the baseline material, with up to 15percent increased discharge capacity.

  18. Angular dependence of metamagnetic transitions in HoNi2B2C 

    E-Print Network [OSTI]

    Canfield, PC; Budko, SL; Cho, BK; Lacerda, A.; Farrell, D.; JohnstonHalperin, E.; Kalatsky, VA; Pokrovsky, Valery L.

    1997-01-01

    Detailed measurements of M(2 K, H, theta) of HoNi2B2C, where theta is the angle that the applied field H makes with the [110] axis while remaining perpendicular to the crystallographic c axis, reveal three metamagnetic transitions with angular...

  19. Microscopic model for the magnetic subsystem in HoNi2B2C 

    E-Print Network [OSTI]

    Kalatsky, VA; Pokrovsky, Valery L.

    1998-01-01

    We demonstrate that the system of localized magnetic moments in HoNi2B2C can be described by the four-positional clock model. This model, at a proper choice of the coupling constants, yields several metamagnetic phases in magnetic field at zero...

  20. Recent advances in alloy design of Ni{sub 3}Al alloys for structural use

    SciTech Connect (OSTI)

    Liu, C.T.; George, E.P.

    1996-12-31

    This is a comprehensive review of recent advances in R&D of Ni{sub 3}Al-based alloys for structural use at elevated temperatures in hostile environments. Recent studies indicate that polycrystalline Ni{sub 3}Al is intrinsically quite ductile at ambient temperatures, and its poor tensile ductility and brittle grain-boundary fracture are caused mainly by moisture-induced hydrogen embrittlement when the aluminide is tested in moisture- or hydrogen-containing environments. Tensile ductility is improved by alloying with substitutional and interstitial elements. Among these additives, B is most effective in suppressing environmental embrittlement and enhancing grain-boundary cohesion, resulting in a dramatic increase of tensile ductility at room temperature. Both B-doped and B-free Ni{sub 3}Al alloys exhibit brittle intergranular fracture and low ductility at intermediate temperatures (300-850 C) because of oxygen-induced embrittlement in oxidizing environments. Cr is found to be most effective in alleviating elevated-temperature embrittlement. Parallel efforts on alloy development using physical metallurgy principles have led to development of several Ni{sub 3}Al alloys for industrial use. The unique properties of these alloys are briefly discussed. 56 refs, 15 figs, 3 tabs.

  1. Investigation of surface endothelialization on biomedical nitinol (NiTi) alloy: Effects of surface micropatterning combined

    E-Print Network [OSTI]

    Lee, James

    Investigation of surface endothelialization on biomedical nitinol (NiTi) alloy: Effects of surface outstanding biocompatibility in our previous studies. In this study, endothelialization on biomedical nitinol- trolled thickness between 40 and 50 nm were deposited onto micropatterned nitinol surface in a direct

  2. Point defects and high temperature creep of NiO single crystals (*) J. Cabrera-Cano

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    durations between 1 h and 18 h have been used, depending on temperature creep test, with no influence on mL-119 Point defects and high temperature creep of NiO single crystals (*) J. Cabrera MPa-150 MPa. Oxygen partial pressures were varied between 10-5 atm. and air. The steady state creep

  3. Aging effects in palladium and LaNi sub 4. 25 Al sub 0. 75 tritides

    SciTech Connect (OSTI)

    Nobile, A.; Wermer, J.R.; Walters, R.T.

    1991-01-01

    Palladium and LaNi{sub 5-x}Al{sub x} (x=0.30, 0.75, 0.85), which form reversible hydrides, are used for tritium processing and storage in the Savannah River Site (SRS) tritium facilities. As part of a program to develop technology based on the use of reversible metal hydrides for tritium processing and storage, the effects of aging on the thermodynamic behavior of palladium and LaNi{sub 4.25}Al{sub 0. 75} tritides are under investigation. During aging, the {sup 3}He tritium decay product remains in the tritide lattice and changes the thermodynamics of the tritium-metal tritide system. Aging effects in 755-day-aged palladium and 1423-day-aged LaNi{sub 4.25}Al{sub 0.75} tritides will be reported. Changes in the thermodynamics were determined by measuring tritium desorption isotherms on aging samples. In palladium, aging decreases the desorption isotherm plateau pressure and changes the {alpha}-phase portion of the isotherm. Aging-induced changes in desorption isotherms are more drastic in LaNi{sub 4.25}Al{sub 0.75}. Among the changes noted are: (1) decreased isotherm plateau pressure, (2) increased isotherm plateau slope, and (3) appearance of deep-trapped tritium, removable only by exchange with deuterium.

  4. Precipitation in the Equiatomic High-Entropy Alloy CrMnFeCoNi

    E-Print Network [OSTI]

    Pickering, E. J.; Muñoz-Moreno, R.; Stone, H. J.; Jones, N. G.

    2015-11-02

    CrMnFeCoNi is widely considered to be an exemplar high-entropy alloy, which is stable as a single solid-solution phase at all temperatures below its melting point. Here, for the first time, the formation of two distinct types of Cr-rich precipitate...

  5. Glass formation in binary and ternary Zr based Fe and Ni bearing alloys

    SciTech Connect (OSTI)

    Savalia, R.T.; Tewari, R.; Banerjee, S.; Dey, G.K.

    1996-01-01

    Rapid solidification of the Zr{sub 76}Fe{sub 24-x}Ni{sub x} alloys (x - 0, 4, 8, 12, 16, 20 and 24) by melt spinning under different conditions has yielded fully amorphous as well as partially crystalline ribbons. The partially crystalline ribbons have been found to contain crystal aggregates comprising a core of the {beta}-Zr phase surrounded by peripheral crystals of the Zr{sub 3}(Fe,Ni) phase in alloys with x < 12. In alloys containing larger amount of Ni (x {ge} 12), both Zr{sub 2}Ni and Zr{sub 3}(Fe,Ni) crystals have been found to be present in the periphery. The nucleation of the core crystals and the peripheral crystals in the undercooled melt has been examined by considering transient and steady state homogeneous and heterogeneous nucleation. The transient nucleation time and the steady state nucleation rate of crystals have been evaluated. For this purpose, use has been made of molar free energy difference {Delta}G{sub c} between the liquid and the crystalline phases determined from experimentally evaluated quantities. The growth of the crystals in the undercooled melt has been examined taking into account recalescence and heat removal during melt spinning. The glass forming ability of the alloys has been evaluated on the basis of the avoidance of crystallization approach. A comparison has been made between the microstructures of the splat cooled and the melt spun alloys in order to understand the process of solidification and the nature of phase transformation during post solidification cooling.

  6. SANS EXAMINATION OF THE Mg{sub 3}CoNi{sub 2} ALLOY FOR HYDROGEN STORAGE MATERIAL

    SciTech Connect (OSTI)

    Insani, Andon; Mulyana, Yohanes Anda [Center for Technology of Nuclear Industry Materials-BATAN, Gedung 40, Kawasan Puspiptek, Serpong, Tangerang Selatan 15310, Banten (Indonesia); Suwarno, Hadi [Center for Technology of Nuclear Fuel-BATAN, Gedung 20, Kawasan Puspiptek, Serpong, Tangerang Selatan 15310, Banten (Indonesia)

    2010-06-22

    The nanocrystalline Mg{sub 3}CoNi{sub 2} alloys have been synthesized from Mg, Co and Ni pure metal powder by using a SPEX 8000 High Energy Milling through wet method with its vial and ball made of stainless steel. A weight ratio of ball to sample was set at 8:1 and the milling times were set at 20 and 30 h. SANS measurements were performed in an instrument SMARTer at BATAN using a distances between 1.5, 4 and 13 m and a wavelength, {lambda}, of 0.39 nm. The SANS investigation results showed that the intensity profiles decrease with q and a power law exponent of about 4. It is suggested that surface Porod scattering dominates. The relative intensity decreases with increased hydrogen concentration, indicating a decline in surface area. Hydrogenation leads to significant changes in the scattering curves mainly due to the 1 Mg{sub 2}Ni attice expansion and changes of the Mg{sub 2}Ni-H/Mg{sub 2}Ni phase boundaries and that of the Mg{sub 2}Ni or Mg{sub 2}NiH{sub 4} grain boundaries. The samples absorb about 3.3 and 1.9 wt% hydrogen with increasing milling time of 20 and 30 h, respectively.

  7. Three-dimensional microstructural changes in the Ni–YSZ solid oxide fuel cell anode during operation

    SciTech Connect (OSTI)

    Nelson G. J.; Chu Y.; Grew, K.N.; Izzo Jr. J.R.; Lombardo, J.J.; Harris, W.M.; Faes, A.; Hessler-Wyser, A.; Van herle, J.; Wang, S.; Virkar, A.V.; Chiu, W.K.S.

    2012-04-07

    Microstructural evolution in solid oxide fuel cell (SOFC) cermet anodes has been investigated using X-ray nanotomography along with differential absorption imaging. SOFC anode supports composed of Ni and yttria-stabilized zirconia (YSZ) were subjected to extended operation and selected regions were imaged using a transmission X-ray microscope. X-ray nanotomography provides unique insight into microstructure changes of all three phases (Ni, YSZ, pore) in three spatial dimensions, and its relation to performance degradation. Statistically significant 3D microstructural changes were observed in the anode Ni phase over a range of operational times, including phase size growth and changes in connectivity, interfacial contact area and contiguous triple-phase boundary length. These observations support microstructural evolution correlated to SOFC performance. We find that Ni coarsening is driven by particle curvature as indicated by the dihedral angles between the Ni, YSZ and pore phases, and hypothesize that growth occurs primarily by means of diffusion and particle agglomeration constrained by a pinning mechanism related to the YSZ phase. The decrease in Ni phase size after extended periods of time may be the result of a second process connected to a mobility-induced decrease in the YSZ phase size or non-uniform curvature resulting in a net decrease in Ni phase size.

  8. Oxidation-resistant, solution-processed plasmonic Ni nanochain-SiO{sub x} (x?

    SciTech Connect (OSTI)

    Yu, Xiaobai; Wang, Xiaoxin; Liu, Jifeng; Zhang, Qinglin; Li, Juchuan

    2014-08-21

    Metal oxidation at high temperatures has long been a challenge in cermet solar thermal absorbers, which impedes the development of atmospherically stable, high-temperature, high-performance concentrated solar power (CSP) systems. In this work, we demonstrate solution-processed Ni nanochain-SiO{sub x} (x?Ni nanochain-SiO{sub 2} selective solar thermal absorbers that exhibit a strong anti-oxidation behavior up to 600?°C in air. The thermal stability is far superior to previously reported Ni nanoparticle-Al{sub 2}O{sub 3} selective solar thermal absorbers, which readily oxidize at 450?°C. The SiO{sub x} (x?Ni/SiO{sub x} interface to passivate the surface of Ni nanoparticles and prevent oxidation. X-ray photoelectron spectroscopy and Raman spectroscopy demonstrate that the excess Si in the SiO{sub x} (x?Ni nanostructures to form silicides at the interfaces, which further improves the anti-oxidation properties. As a result, Ni-SiO{sub x} (x?Ni-SiO{sub 2} systems. This oxidation-resistant Ni nanochain-SiO{sub x} (x?

  9. Influence of Cr and W alloying on the fiber-matrix interfacial shear strength in cast and directionally solidified sapphire NiAl composites

    SciTech Connect (OSTI)

    Asthana, R.; Tiwari, R.; Tewari, S.N.

    1995-08-01

    Sapphire-reinforced NiAl matrix composites with chromium or tungsten as alloying additions were synthesized using casting and zone directional solidification (DS) techniques and characterized by a fiber pushout test as well as by microhardness measurements. The sapphire-NiAl(Cr) specimens exhibited an interlayer of Cr rich eutectic at the fiber-matrix interface and a higher interfacial shear strength compared to unalloyed sapphire-NiAl specimens processed under identical conditions. In contrast, the sapphire-NiAl(W) specimens did not show interfacial excess of tungsten rich phases, although the interfacial shear strength was high and comparable to that of sapphire-NiAl(Cr). The postdebond sliding stress was higher in sapphire-NiAl(Cr) than in sapphire-NiAl(W) due to interface enrichment with chromium particles. The matrix microhardness progressively decreased with increasing distance from the interface in both DS NiAl and NiAl(Cr) specimens. The study highlights the potential of casting and DS techniques to improve the toughness and strength of NiAl by designing dual-phase microstructures in NiAl alloys reinforced with sapphire fibers.

  10. Improving the phase stability and oxidation resistance of B-NiAl

    SciTech Connect (OSTI)

    Brammer, Travis

    2011-08-15

    High temperature alloys are essential to many industries that require a stable material to perform in harsh oxidative environments. Many of these alloys are suited for specific applications such as jet engine turbine blades where most other materials would either melt or oxidize and crumble (1). These alloys must have a high melting temperature, excellent oxidation resistance, good creep resistance, and decent fracture toughness to be successfully used in such environments. The discovery of Ni based superalloys in the 1940s revolutionized the high temperature alloy industry and there has been continued development of these alloys since their advent (2). These materials are capable of operating in oxidative environments in the presence of combustion gases, water vapor and at temperatures around 1050 C. Demands for increased f uel efficiency, however, has highlighted the need for materials that can be used under similar atmospheres and at temperatures in excess of 1200 C. The current Ni based superalloys are restricted to lower temperatures due to the presence of a number of low melting phases that result in softening of the alloys above 1000 C. Therefore, recent research has been aimed at exploring and developing newer alloy systems that can meet the escalating requirements. This thesis comprises a part of such an effort. The motivation of this work is to develop a novel high temperature alloy system that shows improved performance at higher temperatures than the currently employed alloys. The desired alloy should be in accordance with the requirements established in the National Energy Technology Laboratory (NETL) FutureGen program having an operating temperature around 1300 C. Alloys based on NiAl offer significant potential payoffs as structural materials in gas turbine applications due to a unique range of physical and mechanical properties. Alloying additions to NiAl could be used to further improve the pertinent properties that currently limit this system from replacing Ni based superalloys. Modifications to NiAl were explored to increase the phase stability and oxidation resistance which would allow these alloys to be used at even higher temperatures yielding greater efficiencies. The extended Miedema model was an effective tool that screened all of the potential phase space for ternary substitutions to NiAl and found the few potential systems worth further investigation. After production of the alloys it was determined that Ir, Rh, and Pd were the top candidates for substitution on Ni site up to 12 at%. The melting temperature of NiAl could be increased as much as 150 C with 12 at% Ir and 130 C with 12 at% Rh substitution. Pall adium on the other hand decreased the melting temperature by 50 C at the 12 at% substitution level. The grain size was found to have a profound influence on the oxidation resistance. Both Ir and Rh substitutions resulted in finer grain sizes compared to Pd substitutions or base NiAl. The grain size increased drastically during high temperature annealing with the PGM substitutions hindering grain growth only slightly. However, the addition of 0.05 at% Hf limited the grain growth dramatically during high temperature annealing. NiAl inherently has respectable oxidation resistance up to 1100 C. It was found through experimental testing that both Ir and Rh substitutions improve the oxidation resistance of NiAl at ultra-high temperatures with Ir performing the best. Both PGM substitutions decreased the growth rate as well as forming a more adherent oxide scale. Pd substitutions appeared to have a negligible effect to the oxidation resistance of NiAl. Hafnium addition of 0.05 at% was found to decrease the oxidation rate as well as increase the scale adherence. The combination of both Ir substitution (6-9 at%) and Hf addition (0.05 at%) produced the alloy with the best oxidation resistance. Although improvements in phase stability and oxidation resistance have been made to the NiAl system, more development and testing are still needed. Two major issues yet to be resolved are the low fracture toughn

  11. Magnetic domain structure and domain-wall energy in UFe{sub 8}Ni{sub 2}Si{sub 2} and UFe{sub 6}Ni{sub 4}Si{sub 2} intermetallic compounds

    SciTech Connect (OSTI)

    Wyslocki, J.J.; Suski, W.; Wochowski, K.

    1994-03-01

    Magnetic domain structures in the UFe{sub 8}Ni{sub 2}Si{sub 2} and UFe{sub 6}Ni{sub 4}Si{sub 2} compounds were studied using the powder pattern method. The domain structure observed is typical for uniaxial materials. The domain-wall energy density {gamma} was determined from the average surface domain width D{sub s} observed on surfaces perpendicular to the easy axis as equal to 16 erg/cm{sup 2} for UFe{sub 8}Ni{sub 2}Si{sub 2} and 10 erg/cm{sup 2} for UFe{sub 6}Ni{sub 4}Si{sub 2}. Moreover, the critical diameter for single domain particle D{sub c} was calculated for the studied compounds.

  12. Shape memory response and microstructural evolution of a severe plastically deformed high temperature shape memory alloy (NiTiHf) 

    E-Print Network [OSTI]

    Simon, Anish Abraham

    2006-04-12

    NiTiHf alloys have attracted considerable attention as potential high temperature Shape Memory Alloy (SMA) but the instability in transformation temperatures and significant irrecoverable strain during thermal cycling under constant stress remains a...

  13. Using Dynamic DCF and Real Option Methods for Economic Analysis in NI43-101 Technical Reports

    E-Print Network [OSTI]

    Using Dynamic DCF and Real Option Methods for Economic Analysis in NI43-101 Technical Reports or staff. #12;Abstract The introduction of Dynamic Discounted Cash Flow ("Dynamic DCF") and Real Options

  14. Systematic analysis of the crystal structure, chemical ordering, and microstructure of Ni-Mn-Ga ferromagnetic shape memory alloys

    E-Print Network [OSTI]

    Richard, Marc Louis

    2005-01-01

    Ni-n-Ga based ferromagnetic shape-memory alloys (FSMAs) have shown great promise as an active material that yields a large output strain over a range of actuation frequencies. The maximum strain has been reported to be 6% ...

  15. Ni coarsening in the three-phase solid oxide fuel cell anode - a phase-field simulation study

    E-Print Network [OSTI]

    Chen, Hsun-Yi; Cronin, J Scott; Wilson, James R; Barnett, Scott A; Thornton, Katsuyo

    2012-01-01

    Ni coarsening in Ni-yttria stabilized zirconia (YSZ) solid oxide fuel cell anodes is considered a major reason for anode degradation. We present a predictive, quantative modeling framework based on the phase-field approach to systematically examine coarsening kinetics in such anodes. The initial structures for simulations are experimentally acquired functional layers of anodes. Sample size effects and error analysis of contact angles are examined. Three phase boundary (TPB) lengths and Ni surface areas are quantatively identified on the basis of the active, dead-end, and isolated phase clusters throughout coarsening. Tortuosity evolution of the pores is also investigated. We find that phase clusters with larger characteristic length evolve slower than those with smaller length scales. As a result, coarsening has small positive effects on transport, and impacts less on the active Ni surface area than the total counter part. TPBs, however, are found to be sensitive to local morphological features and are only i...

  16. High-Performance ZrO2-Coated LiNiO2 Cathode Material Jaephil Cho,a,

    E-Print Network [OSTI]

    Park, Byungwoo

    O2 has a high-fracture toughness of 8-12 MPa m.16 Experimental LiNiO2 powders were prepared from lattice structure. Since metal oxides with low ductility initiate mechanically induced micro- cracks

  17. Isospin diffusion in semi-peripheral $^{58}Ni$ + $^{197}Au$ collisions at intermediate energies (II): Dynamical simulations

    E-Print Network [OSTI]

    E. Galichet; M. Colonna; B. Borderie; M. F. Rivet

    2008-12-15

    We study isospin effects in semi-peripheral collisions above the Fermi energy by considering the symmetric $^{58}Ni$ + $^{58}Ni$ and the asymmetric reactions $^{58}Ni$ + $^{197}Au$ over the incident energy range 52-74 A MeV. A microscopic transport model with two different parameterizations of the symmetry energy term is used to investigate the isotopic content of pre-equilibrium emission and the N/Z diffusion process. Simulations are also compared to experimental data obtained with the INDRA array and bring information on the degree of isospin equilibration observed in Ni + Au collisions. A better overall agreement between data and simulations is obtained when using a symmetry term which linearly increases with nuclear density.

  18. Type of presentation: Oral ID-12-O-2236 Measurements of local chemistry and structure in NiO/YSZ composites

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    , Germany, 4 Fuelmat Group, School of Engineering, Ecole Polytechnique Fédérale de Lausanne, LausanneO)/yttria-stabilized zirconia (YSZ) composite to the electrochemically active Ni/YSZ state, is assessed using energy

  19. Frequency Dependence Modulus of Pd??Ni??Cu??P?? Amorphous Alloy around the Glass Transition by Dynamic Mechanical Analysis

    E-Print Network [OSTI]

    Lee, M.L.

    Dynamic Mechanical Analyzer (DMA) was used to study the frequency dependence of storage and loss modulus of amorphous Pd??Ni??Cu??P?? alloy over a broad frequency range around its glass transition temperature. The amorphous ...

  20. PII S0016-7037(00)00385-9 Stability of layered Ni hydroxide surface precipitates--A dissolution kinetics study

    E-Print Network [OSTI]

    Sparks, Donald L.

    in stability, as was documented by decreasing amounts of Ni released by nitric acid (HNO3) and ethylenediaminetetraacetic acid (EDTA) treatments. This aging effect may be partly explained by the silicate

  1. Ab initio study of structural, electronic, magnetic alloys: XTiSb (X = Co, Ni and Fe)

    SciTech Connect (OSTI)

    Ibrir, M. Berri, S.; Lakel, S.; Alleg, S.; Bensalem, R.

    2015-03-30

    Structural, electronic and magnetic properties of three semi-Heusler compounds of CoTiSb, NiTiSb and FeTiSb were calculated by the method (FP-LAPW) which is based on the DFT code WIEN2k. We used the generalized gradient approximation (GGA (06)) for the term of the potential exchange and correlation (XC) to calculate structural properties, electronic properties and magnetic properties. Structural properties obtained as the lattice parameter are in good agreement with the experimental results available for the electronic and magnetic properties was that: CoTiSb is a semiconductor NiTiSb is a metal and FeTiSb is a half-metal ferromagnetic.

  2. Bulk glass formation in the Pd{endash}Ni{endash}P system

    SciTech Connect (OSTI)

    He, Y.; Schwarz, R.B.; Archuleta, J.I. [Center for Materials Science, MS K-765, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Center for Materials Science, MS K-765, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    1996-09-01

    Bulk amorphous Pd{endash}Ni{endash}P rods with diameters ranging from 10 to 25 mm were prepared by a fluxing technique over a wide composition range. For most bulk glassy alloys studied, the difference between the glass transition temperature and the crystallization temperature, {ital T}{sub {ital x}}{minus}{ital T}{sub {ital g}}, is larger than 90 K. Of all the alloy compositions examined, Pd{sub 40}Ni{sub 40}P{sub 20} has the highest glass formability, and 300-g bulk amorphous cylinders, 25 mm in diameter and 50 mm in length, were easily and repeatedly formed. This size, however, is not an upper limit. The elastic properties of these bulk amorphous alloys were determined by a resonant ultrasound spectroscopy technique.

  3. Magnetic properties of double perovskite La2BMnO6 (B = Ni or Co) nanoparticles

    SciTech Connect (OSTI)

    Mao, Yuanbing; Parsons, Jason; McCloy, John S.

    2013-03-31

    Double perovskite La2BMnO6 (B = Ni and Co) nanoparticles with average particle size of ~50 nm were synthesized using a facile, environmentally friendly, scalable molten-salt reaction at 700 °C in air. Their structural and morphological properties were characterized by x-ray diffraction and transmission electron microscopy. Magnetic properties were evaluated using dc magnetic M-T and M-H, and ac magnetic susceptibility versus frequency, temperature, and field. The magnetization curve shows a paramagnetic-ferromagnetic transition at TC ~275 and 220 K for La2NiMnO6 (LNMO) and La2CoMnO6 (LCMO) nanoparticles, respectively. ac susceptibility revealed that the LCMO had a single magnetic transition indicative of Co2+-O2--Mn4+ ordering, whereas the LNMO showed more complex magnetic behavior suggesting a re-entrant spin glass.

  4. Numerical prediction of the thermodynamic properties of ternary Al-Ni-Hf alloys

    SciTech Connect (OSTI)

    Romanowska, Jolanta; Kotowski, S?awomir; Zagula-Yavorska, Maryana

    2014-10-06

    Thermodynamic properties of ternary Al-Hf-Ni system, such as {sup ex}G, ?{sub Al}, ?{sub Ni} and ?{sub Zr} at 1373K were predicted on the basis of thermodynamic properties of binary systems included in the investigated ternary system. The idea of predicting {sup ex}G values was regarded as the calculation of excess Gibbs energy values inside a certain area (a Gibbs triangle) unless all boundary conditions, that is values of {sup ex}G on all legs of the triangle are known. {sup ex}G and L{sub ijk} ternary interaction parameters in the Muggianu extension of the Redlich-Kister formalism are calculated numerically using Wolfram Mathematica 9 software.

  5. A Ni-Fe Layered Double Hydroxide-Carbon Nanotube Complex for Water Oxidation

    E-Print Network [OSTI]

    Gong, Ming; Wang, Hailiang; Liang, Yongye; Wu, Justin Zachary; Zhou, Jigang; Wang, Jian; Regier, Tom; Wei, Fei; Dai, Hongjie

    2013-01-01

    Highly active, durable and cost-effective electrocatalysts for water oxidation to evolve oxygen gas hold a key to a range of renewable energy solutions including water splitting and rechargeable metal-air batteries. Here, we report the synthesis of ultrathin nickel iron layered double hydroxide nanoplates on mildly oxidized multi-walled carbon nanotubes. Incorporation of Fe into the nickel hydroxide induced the formation of NiFe-layered double hydroxide. The nanoplates were covalently attached to a network of nanotubes, affording excellent electrical wiring to the nanoplates. The ultra-thin Ni-Fe layered double hydroxide nanoplates/carbon nanotube complex was found to exhibit unusually high electro-catalytic activity and stability for oxygen evolution and outperformed commercial precious metal Ir catalysts.

  6. KADoNiS- The Karlsruhe Astrophysical Database of Nucleosynthesis in Stars

    E-Print Network [OSTI]

    I. Dillmann; M. Heil; F. Käppeler; R. Plag; T. Rauscher; F. -K. Thielemann

    2008-05-30

    The "Karlsruhe Astrophysical Database of Nucleosynthesis in Stars" (KADoNiS) project is an online database for experimental cross sections relevant to the s process and p process. It is available under http://nuclear-astrophysics.fzk.de/kadonis and consists of two parts. Part 1 is an updated sequel to the previous Bao et al. compilations from 1987 and 2000 for (n,$\\gamma$) cross sections relevant to the big bang and s-process nucleosynthesis. The second part will be an experimental p-process database, which is expected to be launched in winter 2005/06. The KADoNiS project started in April 2005, and a first partial update is online since August 2005. In this paper we present a short overview of the first update of the s-process database, as well as an overview of the status of stellar (n,$\\gamma$) cross sections of all 32 p isotopes.

  7. Interfacial shear strength of cast and directionally solidified NiAl-sapphire fiber composites

    SciTech Connect (OSTI)

    Tewari, S.N.; Asthana, R. . Chemical Engineering Dept.); Noebe, R.D. . Intermetallics Branch)

    1993-09-01

    The feasibility of fabricating intermetallic NiAl-sapphire fiber composites by casting and zone directional solidification has been examined. The fiber-matrix interfacial shear strengths measured using a fiber push-out technique in both cast and directionally solidified composites are greater than the strengths reported for composites fabricated by powder cloth process using organic binders. Microscopic examination of fibers extracted from cast, directionally solidified (DS), and thermally cycled composites, and the high values of interfacial shear strengths suggest that the fiber-matrix interface does not degrade due to casting and directional solidification. Sapphire fibers do not pin grain boundaries during directional solidification, suggesting that this technique can be used to fabricate sapphire fiber reinforced NiAl composites with single crystal matrices.

  8. Synthesis and characterization of NiFe{sub 2}O{sub 4}–Pd magnetically recyclable catalyst for hydrogenation reaction

    SciTech Connect (OSTI)

    Karao?lu, E.; Özel, U.; Caner, C.; Baykal, A.; Summak, M.M.; Sözeri, H.

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ? Novel superparamagnetic NiFe{sub 2}O{sub 4}–Pd magnetically recyclable catalyst was fabricated through co-precipitation. ? It could be reused several times without significant loss in catalytic activity for hydrogenation reaction. ? No further modification of the NiFe{sub 2}O{sub 4}–Pd magnetically recyclable catalyst is necessary for utilization as catalyst. -- Abstract: Herein we report the fabrication and characterization magnetically recyclable catalysts of NiFe{sub 2}O{sub 4}–Pd nanocomposite as highly effective catalysts for reduction reactions in liquid phase. The reduction Pd{sup 2+} was accomplished with polyethylene glycol 400 (PEG-400) instead of sodium borohydride (NaBH{sub 4}) and NiFe{sub 2}O{sub 4} nanoparticles was prepared by sonochemically using FeCI{sub 3}·6H{sub 2}O and NiCl{sub 2}. The chemical characterization of the product was done with X-ray diffractometry, Infrared spectroscopy, transmission electron microscopy, UV–Vis spectroscopy, thermal gravimetry and inductively coupled plasma. Thus formed NiFe{sub 2}O{sub 4}–Pd MRCs showed a very high activity in reduction reactions of 4-nitro aniline and 1,3-dinitrobenzene in liquid phase. It was found out that the catalytic activity of NiFe{sub 2}O{sub 4}–Pd MRCs on the reduction of 4-nitro aniline and 1,3-dinitrobenzene in liquid phase are between 99–93% and 98–93%, respectively. Magnetic character of this system allowed recovery and multiple use without significant loss of its catalytic activity. It is found that NiFe{sub 2}O{sub 4}–Pd MRCs showed very efficient catalytic activity and multiple usability.

  9. On the amorphization behavior and hydrogenation performance of high-energy ball-milled Mg{sub 2}Ni alloys

    SciTech Connect (OSTI)

    Kou, Hongchao; Hou, Xiaojiang; Zhang, Tiebang, E-mail: tiebangzhang@nwpu.edu.cn; Hu, Rui; Li, Jinshan; Xue, Xiangyi

    2013-06-15

    Amorphous Mg{sub 2}Ni alloy was prepared by high energy ball-milling starting with polycrystalline Mg{sub 2}Ni which was prepared with the help of a metallurgy method by using a SPEX 8000D mill. The microstructural and phase structure characterization of the prepared materials was performed via scanning electron microscopy, transition electron microscope and X-ray diffraction. The thermal stabilities were investigated by differential scanning calorimetry. The apparent activation energies were determined by means of the Kissinger method. The first and second crystallization reactions take place at ? 255 °C and ? 410 °C, and the corresponding activation energy of crystallization is E{sub a1} = 276.9 and E{sub a2} = 382.4 kJ/mol, respectively. At 3 MPa hydrogen pressure and 250 °C, the hydrogen absorption capacities of crystalline, partially and fully amorphous Mg{sub 2}Ni alloy are 2.0 wt.%, 3.2 wt.% and 3.5 wt.% within 30 min, respectively. - Graphical Abstract: We mainly focus on the amorphization behavior of crystalline Mg{sub 2}Ni alloy in the high energy ball-milling process and the crystallization behavior of the amorphous Mg{sub 2}Ni alloy in a follow-up heating process. The relationship of milling, microstructure and hydrogenation properties is established and explained by models. - Highlights: • Amorphous Mg{sub 2}Ni has been obtained by high energy ball milling the as-cast alloy. • The amorphization behavior of polycrystalline Mg{sub 2}Ni is presented. • The crystallization behavior of the amorphous Mg{sub 2}Ni alloy is illustrated. • Establish the relationship of milling, microstructure and hydrogenation properties.

  10. The energy dependence of flow in Ni induced collisions from 400 to 1970A MeV

    E-Print Network [OSTI]

    Jerry Chance; the EOS-Collaboration

    1996-07-23

    We study the energy dependence of collective (hydrodynamic-like) nuclear matter flow in 400-1970 A MeV Ni+Au and 1000-1970 A MeV Ni+Cu reactions. The flow increases with energy, reaches a maximum, and then gradually decreases at higher energies. A way of comparing the energy dependence of flow values for different projectile-target mass combinations is introduced, which demonstrates a common scaling behaviour among flow values from different systems.

  11. Influence of $?$ mesons on negative kaons in Ni+Ni collisions at 1.91A GeV beam energy

    E-Print Network [OSTI]

    K. Piasecki; N. Herrmann; R. Averbeck; A. Andronic; V. Barret; Z. Basrak; N. Bastid; M. L. Benabderrahmane; M. Berger; P. Buehler; M. Cargnelli; R. ?aplar; P. Crochet; O. Czerwiakowa; I. Deppner; P. Dupieux; M. Dželalija; L. Fabbietti; Z. Fodor; P. Gasik; I. Gašpari?; Y. Grishkin; O. N. Hartmann; K. D. Hildenbrand; B. Hong; T. I. Kang; J. Kecskemeti; Y. J. Kim; M. Kirejczyk; M. Kiš; P. Koczon; R. Kotte; A. Lebedev; Y. Leifels; A. Le Fèvre; J. L. Liu; X. Lopez; V. Manko; J. Marton; T. Matulewicz; R. Münzer; M. Petrovici; F. Rami; A. Reischl; W. Reisdorf; M. S. Ryu; P. Schmidt; A. Schüttauf; Z. Seres; B. Sikora; K. S. Sim; V. Simion; K. Siwek-Wilczy?ska; V. Smolyankin; K. Suzuki; Z. Tymi?ski; P. Wagner; I. Weber; E. Widmann; K. Wi?niewski; Z. G. Xiao; I. Yushmanov; Y. Zhang; A. Zhilin; V. Zinyuk; J. Zmeskal

    2014-12-15

    $\\phi$ and K$^-$ mesons from Ni+Ni collisions at the beam energy of 1.91A GeV have been measured by the FOPI spectrometer, with a trigger selecting central and semi-central events amounting to 51% of the total cross section. The phase space distributions, and the total yield of K$^-$, as well as the kinetic energy distribution and the total yield of $\\phi$ mesons are presented. The $\\phi$\\K$^-$ ratio is found to be $0.44 \\pm 0.07(\\text{stat}) ^{+0.18}_{-0.12} (\\text{syst})$, meaning that about 22% of K$^-$ mesons originate from the decays of $\\phi$ mesons, occurring mostly in vacuum. The inverse slopes of direct kaons are up to about 15 MeV larger than the ones extracted within the one-source model, signalling that a considerable share of gap between the slopes of K$^+$ and K$^-$ could be explained by the contribution of $\\phi$ mesons to negative kaons.

  12. Um Estudo de Algoritmos para Visualizao Simultnea de Dados Volumtricos e Superfcies Poligonais

    E-Print Network [OSTI]

    de Figueiredo, Luiz Henrique

    Um Estudo de Algoritmos para Visualização Simultânea de Dados Volumétricos e Superfícies Poligonais algoritmos de visualização volumétrica direta e algumas variações de forma a permitir a renderização simultânea de dados volumétricos e superfícies poligonais. São apresentadas versões de algoritmos híbridos de

  13. Prmio Cientfico IBM 2012 distingue um trabalho de investigao do Instituto Superior Tcnico

    E-Print Network [OSTI]

    Instituto de Sistemas e Robotica

    Prémio Científico IBM 2012 distingue um trabalho de investigação do Instituto Superior Técnico 0 Publicado 28 de Maio de 2013 por Luis Vedor em Notícias O Prémio Científico IBM referente ao ano de 2012 Técnico, em Lisboa. É a segunda vez que uma mulher recebe o galardão. O Prémio Científico IBM, no valor de

  14. Lamper, Karen Teresa From: UM Research Listserv on behalf of Lamper,

    E-Print Network [OSTI]

    Shyu, Mei-Ling

    -L@LISTSERV.MIAMI.EDU Subject: Internal Competition for NSF, Mid-Scale Innovations Program in Astronomical Sciences (MSIP): UM Science Foundation (NSF), MidScale Innovations Program in Astronomical Sciences (MSIP) is 7/27/15. If you15580.htm Purpose: The MidScale Innovations Program (MSIP) is designed to fill the need

  15. Thomas/Fischer 1 UM-96 Using Agents to Improve the

    E-Print Network [OSTI]

    Fischer, Gerhard

    Christoph G. Thomas1,2 & Gerhard Fischer3 Abstract: The World-Wide Web (WWW) has emerged as a new typeThomas/Fischer 1 UM-96 Using Agents to Improve the Usability and Usefulness of the World-Wide Web and overcome problems of global information spaces such as the WWW, we have designed and implemented

  16. Constraints on shallow {sup 56}Ni from the early light curves of type Ia supernovae

    SciTech Connect (OSTI)

    Piro, Anthony L. [Theoretical Astrophysics, California Institute of Technology, 1200 E California Boulevard, M/C 350-17, Pasadena, CA 91125 (United States); Nakar, Ehud, E-mail: piro@caltech.edu [Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel)

    2014-03-20

    Ongoing transient surveys are presenting an unprecedented account of the rising light curves of Type Ia supernovae (SNe Ia). This early emission probes the shallowest layers of the exploding white dwarf (WD), which can provide constraints on the progenitor star and the properties of the explosive burning. We use semianalytic models of radioactively powered rising light curves to analyze these observations. As we have summarized in previous work, the main limiting factor in determining the surface distribution of {sup 56}Ni is the lack of an unambiguously identified time of explosion, as would be provided by detection of shock breakout or shock-heated cooling. Without this the SN may in principle exhibit a 'dark phase' for a few hours to days, where the only emission is from shock-heated cooling that is too dim to be detected. We show that by assuming a theoretically motivated time-dependent velocity evolution, the explosion time can be better constrained, albeit with potential systematic uncertainties. This technique is used to infer the surface {sup 56}Ni distributions of three recent SNe Ia that were caught especially early in their rise. In all three we find fairly similar {sup 56}Ni distributions. Observations of SN 2011fe and SN 2012cg probe shallower depths than SN 2009ig, and in these two cases {sup 56}Ni is present merely ?10{sup –2} M {sub ?} from the WDs' surfaces. The uncertainty in this result is up to an order of magnitude given the difficulty of precisely constraining the explosion time. We also use our conclusions about the explosion times to reassess radius constraints for the progenitor of SN 2011fe, as well as discuss the roughly t {sup 2} power law that is inferred for many observed rising light curves.

  17. Low energy ($p,?$) reactions in Ni and Cu nuclei using microscopic optical model

    E-Print Network [OSTI]

    G. Gangopadhyay

    2010-08-05

    Radiative capture reactions for low energy protons have been theoretically studied for Ni and Cu isotopes using the microscopic optical model. The optical potential has been obtained in the folding model using different microscopic interactions with the nuclear densities from Relativistic Mean Field calculations. The calculated total cross sections as well as the cross sections for individually low lying levels have been compared with measurements involving stable nuclear targets. Rates for the rapid proton capture process have been evaluated for astrophysically important reactions.

  18. Synthesis of mesoporous NiO doped TiO{sub 2} submicrosphere via spray hydrolysis

    SciTech Connect (OSTI)

    Bahadur, J.; Sen, D.; Prakash, J.; Singh, Ripandeep; Paul, B.; Mazumder, S.; Sathiyamoorthy, D.

    2012-06-05

    NiO doped TiO{sub 2} submicrosphere have been prepared via spray hydrolysis. The doping concentration has been varied form 2 wt% to 15 wt%. Morphology of the submicrospheres has been investigated using small-angle neutron scattering and scanning electron microscopy. Elemental analysis has been carried out by energy dispersive X-ray analysis which confirms the doping concentrations. The mesopores in submicrospheres possess cylindrical morphology.

  19. Synthesis of pure, active, and fine NiFe?O? by aerosolization 

    E-Print Network [OSTI]

    Yu, Hsuan-Fu

    1989-01-01

    in water, a dilute aqueous solution of Ni(II) and Fe(III) nitrates was used to prepare as starting material to synthesize pure, active, and fine nickel ferrite powders. The pyrolysis temperature was varied from 450'C to 810'C. The final product.... As the pyrolysis temperature increased, sintering occurred, larger particles and broader size distribution were obtained, and the degree of crystallinity of nickel ferrite increased. The products at pyrolysis temperatures of 660'C and above exhibited magnetic...

  20. Incorporation of trace elements in Portland cement clinker: Thresholds limits for Cu, Ni, Sn or Zn

    SciTech Connect (OSTI)

    Gineys, N.; Aouad, G.; Sorrentino, F.; Damidot, D.

    2011-11-15

    This paper aims at defining precisely, the threshold limits for several trace elements (Cu, Ni, Sn or Zn) which correspond to the maximum amount that could be incorporated into a standard clinker whilst reaching the limit of solid solution of its four major phases (C{sub 3}S, C{sub 2}S, C{sub 3}A and C{sub 4}AF). These threshold limits were investigated through laboratory synthesised clinkers that were mainly studied by X-ray Diffraction and Scanning Electron Microscopy. The reference clinker was close to a typical Portland clinker (65% C{sub 3}S, 18% C{sub 2}S, 8% C{sub 3}A and 8% C{sub 4}AF). The threshold limits for Cu, Ni, Zn and Sn are quite high with respect to the current contents in clinker and were respectively equal to 0.35, 0.5, 0.7 and 1 wt.%. It appeared that beyond the defined threshold limits, trace elements had different behaviours. Ni was associated with Mg as a magnesium nickel oxide (MgNiO{sub 2}) and Sn reacted with lime to form a calcium stannate (Ca{sub 2}SnO{sub 4}). Cu changed the crystallisation process and affected therefore the formation of C{sub 3}S. Indeed a high content of Cu in clinker led to the decomposition of C{sub 3}S into C{sub 2}S and of free lime. Zn, in turn, affected the formation of C{sub 3}A. Ca{sub 6}Zn{sub 3}Al{sub 4}O{sub 15} was formed whilst a tremendous reduction of C{sub 3}A content was identified. The reactivity of cements made with the clinkers at the threshold limits was followed by calorimetry and compressive strength measurements on cement paste. The results revealed that the doped cements were at least as reactive as the reference cement.

  1. Propagating spectroscopy of backward volume spin waves in a metallic FeNi film

    SciTech Connect (OSTI)

    Sato, N.; Ishida, N.; Kawakami, T.; Sekiguchi, K.

    2014-01-20

    We report a propagating spin wave spectroscopy for a magnetostatic backward volume spin wave in a metallic Fe{sub 19}Ni{sub 81} film. We show that the mutual-inductance between two independent antennas detects a small but clear propagation signal of backward volume spin waves. All experimental data are consistent with the time-domain propagating spin-wave spectroscopy. The control of propagating backward spin wave enables to realize the miniaturize spin-wave circuit.

  2. The effect of substrate constraint on the martensitic transformation of Ni-Ti thin films

    SciTech Connect (OSTI)

    Mathews, S.A.; Wuttig, M.; Su, Q. [Univ. of Maryland, College Park, MD (United States). Dept. of Materials and Nuclear Engineering

    1996-09-01

    Previous work on an equiatomic alloy of nickel and titanium (nitinol) indicates that the martensitic transformation in thin films may be suppressed by interfacial constraint imposed by the substrate. Ni{sub 50}Ti{sub 50} films were deposited at room temperature on oxidized (100) Si substrates and tested to determine when the martensitic transformation occurred for both attached and free-standing conditions.

  3. Bimetallic Ni-Rh catalysts with low amounts of Rh for the steam and autothermal reforming of n-butane for fuel-cell applications.

    SciTech Connect (OSTI)

    Ferrandon, M.; Kropf, A. J.; Krause, T.; Chemical Sciences and Engineering Division

    2010-05-15

    Mono-metallic nickel and rhodium catalysts and bimetallic Ni-Rh catalysts supported on La-Al{sub 2}O{sub 3}, CeZrO{sub 2} and CeMgOx were prepared and evaluated for catalyzing the steam and autothermal reforming of n-butane. The binary Ni-Rh supported on La-Al{sub 2}O{sub 3} catalysts with low weight loading of rhodium exhibited higher H{sub 2} yields than Ni or Rh alone. The Ni-Rh/CeZrO{sub 2} catalyst exhibited higher performance and no coke formation, compared to the same metals on other supports. A NiAl{sub 2}O{sub 4} spinel phase was obtained on all Ni and Ni-Rh catalysts supported on La-Al{sub 2}O{sub 3}. The presence of rhodium stabilized the spinel phase as well as NiOx species upon reforming while Ni alone was mostly reduced into metallic species. Extended X-ray absorption fine-structure analysis showed evidence of Ni-Rh alloy during preparation and even further after an accelerated aging at 900C in a H{sub 2}/H{sub 2}O atmosphere.

  4. Effect of oxygen vacancy on half metallicity in Ni-doped CeO{sub 2} diluted magnetic semiconductor

    SciTech Connect (OSTI)

    Saini, Hardev S. Saini, G. S. S.; Singh, Mukhtiyar; Kashyap, Manish K.

    2015-05-15

    The electronic and magnetic properties of Ni-doped CeO{sub 2} diluted amgentic semiconductor (DMS) including the effect of oxygen vacancy (V{sub o}) with doping concentration, x = 0.125 have been calculated using FPLAPW method based on Density Functional Theory (DFT) as implemented in WIEN2k. In the present supercell approach, the XC potential was constructed using GGA+U formalism in which Coulomb correction is applied to standard GGA functional within the parameterization of Perdew-Burke-Ernzerhof (PBE). We have found that the ground state properties of bulk CeO{sub 2} compound have been modified significantly due to the substitution of Ni-dopant at the cation (Ce) site with/without V{sub O} and realized that the ferromagnetism in CeO{sub 2} remarkably depends on the V{sub o} concentrations. The presence of V{sub o}, in Ni-doped CeO{sub 2}, can leads to strong ferromagnetic coupling between the nearest neighboring Ni-ions and induces a HMF in this compound. Such ferromagnetic exchange coupling is mainly attributed to spin splitting of Ni-d states, via electrons trapped in V{sub o}. The HMF characteristics of Ni-doped CeO{sub 2} including V{sub o} makes it an ideal material for spintronic devices.

  5. Ligand-Based Steric Effects in Ni-Catalyzed Chain-Growth Polymerizations Using Bis(dialkylphosphino)ethanes

    SciTech Connect (OSTI)

    Lanni, Erica L.; Locke, Jonas R.; Gleave, Christine M.; McNeil, Anne J.

    2011-07-12

    The role of ligand-based steric effects was investigated in the polymerization of 4-bromo-2,5-bis(hexyloxy)phenylmagnesium chloride. Three different Ni(L-L)Cl? catalysts were synthesized using commercially available bis(dialkylphosphino)ethane ligands with varying steric properties. One of these catalysts (Ni(depe)Cl?) outperformed the others for this polymerization. The polymer characterization data were consistent with a chain-growth mechanism. Rate and spectroscopic studies revealed a rate-limiting reductive elimination for both initiation and propagation with Ni(depe)Cl?. In contrast, less hindered Ni(dmpe)Cl? and more hindered Ni(dcpe)Cl? were ineffective polymerization catalysts; NMR spectroscopic studies indicated that competing decomposition and uncontrolled pathways intervene. For other monomers, Ni(depe)Cl? performed similar to the conventional catalysts. Copolymerization studies revealed that block copolymers could be effectively prepared. Overall, these studies indicate that altering the ligand-based steric properties can have a significant impact on the chain-growth polymerization.

  6. Rationalization of Au concentration and distribution in AuNi@Pt core-shell nanoparticles for oxygen reduction reaction

    SciTech Connect (OSTI)

    An, Wei; Liu, Ping

    2015-09-18

    Improving the activity and stability of Pt-based core–shell nanocatalysts for proton exchange membrane fuel cells while lowering Pt loading has been one of the big challenges in electrocatalysis. Here, using density functional theory, we report the effect of adding Au as the third element to enhance the durability and activity of Ni@Pt core–shell nanoparticles (NPs) during the oxygen reduction reaction (ORR). Our results show that the durability and activity of a Ni@Pt NP can be finely tuned by controlling Au concentration and distribution. For a NiAu@Pt NP, the durability can be greatly promoted by thermodynamically favorable segregation of Au to replace the Pt atoms at vertex, edge, and (100) facets on the shell, while still keeping the ORR activity on the active Pt(111) shell as high as that of Ni@Pt nanoparticles. Such behavior strongly depends on a direct interaction with the Ni interlayer. The results not only highlight the importance of interplay between surface strain on the shell and the interlayer–shell interaction in determining the durability and activity but also provide guidance on how to maximize the usage of Au to optimize the performance of core–shell (Pt) nanoparticles. As a result, such understanding has allowed us to discover a novel NiAu@Pt nanocatalyst for the ORR.

  7. Rationalization of Au concentration and distribution in AuNi@Pt core-shell nanoparticles for oxygen reduction reaction

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    An, Wei; Liu, Ping

    2015-09-18

    Improving the activity and stability of Pt-based core–shell nanocatalysts for proton exchange membrane fuel cells while lowering Pt loading has been one of the big challenges in electrocatalysis. Here, using density functional theory, we report the effect of adding Au as the third element to enhance the durability and activity of Ni@Pt core–shell nanoparticles (NPs) during the oxygen reduction reaction (ORR). Our results show that the durability and activity of a Ni@Pt NP can be finely tuned by controlling Au concentration and distribution. For a NiAu@Pt NP, the durability can be greatly promoted by thermodynamically favorable segregation of Au tomore »replace the Pt atoms at vertex, edge, and (100) facets on the shell, while still keeping the ORR activity on the active Pt(111) shell as high as that of Ni@Pt nanoparticles. Such behavior strongly depends on a direct interaction with the Ni interlayer. The results not only highlight the importance of interplay between surface strain on the shell and the interlayer–shell interaction in determining the durability and activity but also provide guidance on how to maximize the usage of Au to optimize the performance of core–shell (Pt) nanoparticles. As a result, such understanding has allowed us to discover a novel NiAu@Pt nanocatalyst for the ORR.« less

  8. Preparation and characterization of nanostructured NiO/MnO{sub 2} composite electrode for electrochemical supercapacitors

    SciTech Connect (OSTI)

    Liu Enhui Li Wen; Li Jian; Meng Xiangyun; Ding Rui; Tan Songting

    2009-05-06

    Nanostructured nickel-manganese oxides composite was prepared by the sol-gel and the chemistry deposition combination new route. The surface morphology and structure of the composite were characterized by scanning electron microscope and X-ray diffraction. The as-synthesized NiO/MnO{sub 2} samples exhibit higher surface area of 130-190 m{sup 2} g{sup -1}. Cyclic voltammetry and galvanostatic charge/discharge measurements were applied to investigate the electrochemical performance of the composite electrodes with different ratios of NiO/MnO{sub 2}. When the mass ratio of MnO{sub 2} and NiO in composite material is 80:20, the specific capacitance value of NiO/MnO{sub 2} calculated from the cyclic voltammetry curves is 453 F g{sup -1}, for pure NiO and MnO{sub 2} are 209, 330 F g{sup -1} in 6 mol L{sup -1} KOH electrolyte and at scan rate of 10 mV s{sup -1}, respectively. The specific capacitance of NiO/MnO{sub 2} electrode is much larger than that of each pristine component. Moreover, the composite electrodes showed high power density and stable electrochemical properties.

  9. A practical grinding-assisted dry synthesis of nanocrystalline NiMoO{sub 4} polymorphs for oxidative dehydrogenation of propane

    SciTech Connect (OSTI)

    Chen Miao; Wu Jialing; Liu Yongmei; Cao Yong; Guo Li; He Heyong; Fan Kangnian

    2011-12-15

    A practical two-stage reactive grinding-assisted pathway waste-free and cost-effective for the synthesis of NiMoO{sub 4} has been successfully developed. It was demonstrated that proper design in synthetic strategy for grinding plays a crucial role in determining the ultimate polymorph of NiMoO{sub 4}. Specifically, direct grinding (DG) of MoO{sub 3} and NiO rendered {alpha}-NiMoO{sub 4} after annealing, whereas sequential grinding (SG) of the two independently pre-ground oxides followed by annealing generated {beta}-NiMoO{sub 4} solid solution. Characterizations in terms of Raman and X-ray diffraction suggest the creation of {beta}-NiMoO{sub 4} precursor in the latter alternative is the key aspect for the formation of {beta}-NiMoO{sub 4}. The DG-derived {alpha}-NiMoO{sub 4} tested by oxidative dehydrogenation of propane exhibited superior activity in contrast to its analog synthesized via conventional coprecipitation. It is suggested that the favorable chemical composition facilely obtained via grinding in contrast to that by coprecipitation was essential for achieving a more selective production of propylene. - Graphical Abstract: Grinding-assisted synthesis of NiMoO{sub 4} offers higher and more reproducible activities in contrast to coprecipitation for oxidative dehydrogenation of propane, and both {alpha}- and {beta}-NiMoO{sub 4} can be synthesized. Highlights: Black-Right-Pointing-Pointer NiMoO{sub 4} was prepared through grinding-assisted pathway. Black-Right-Pointing-Pointer Direct/sequential grinding rendered {alpha}-, {beta}-NiMoO{sub 4}, respectively. Black-Right-Pointing-Pointer Grinding-derived {alpha}-NiMoO{sub 4} showed high and reproducible activity for oxidative dehydrogenation of propane.

  10. Synthesis and Oxidation Behavior of Platinum-Enriched ?+?' Bond Coatings on Ni-Based Superalloys

    SciTech Connect (OSTI)

    Zhang, Ying [Tennessee Technological University; Ballard, D A [Tennessee Technological University; Stacy, J P [Tennessee Technological University; Pint, Bruce A [ORNL; Haynes, James A [ORNL

    2006-01-01

    Simple Pt-enriched {gamma}+{gamma}{prime} coatings were synthesized on Rene 142 and Rene N5 Ni-based superalloys by electroplating a thin layer of Pt followed by a diffusion treatment at 1150-1175 C. The Al content in the resulting {gamma}+{gamma}{prime} coating was in the range of 16-19 at.% on superalloys with 13-14 at.% Al. After oxidation testing, alumina scale adherence to these {gamma}+{gamma}{prime} coatings was not as uniform as to the {beta}-(Ni,Pt)Al coatings on the same superalloy substrates. To better understand the effect of Al, Pt and Hf concentrations on coating oxidation resistance, a number of Ni-Pt-Al cast alloys with {gamma}+{gamma}{prime} or {beta} phase were cyclically oxidized at 1100 C. The Hf-containing {gamma}+{gamma}{prime} alloys with 22 at.% Al and 10-30 at.% Pt exhibited similar oxidation resistance to the {beta} alloys with 50 at.% Al. An initial effort was made to increase the Al content in the Pt-enriched {gamma}+{gamma}{prime} coatings by introducing a short-term aluminizing process via chemical vapor deposition or pack cementation. However, too much Al was deposited, leading to the formation of {beta} or martensitic phase on the coating surface.

  11. Computational study of hydrocarbon adsorption in metal-organic framework Ni2(dhtp)

    SciTech Connect (OSTI)

    Sun, Xiuquan; Wick, Collin D.; Thallapally, Praveen K.; McGrail, B. Peter; Dang, Liem X.

    2011-03-31

    Molecular dynamic simulations were carried out to study the sorption, structural properties, and diffusivities of n-hexane and cyclohexane adsorbed in Ni2(dhtp). The results indicated strong interactions between the alkanes and the host material. The free energy perturbation method was employed to investigate the adsorption free energies of methane, ethane, n-butane, n-hexane and cyclohexane. For linear alkanes, the free energy lowered as the length of the carbon chain increased. Also, the adsorption of n-hexane was preferred over cyclohexane, due to its ability to rearrange its structure to maximize contacts with the host. Furthermore, due to the large pore size of Ni2(dhtp), higher loadings of alkanes did not significantly affect the alkane structure, and enhanced the free energy of adsorption for subsequent alkanes being loaded. According to our studies, Ni2(dhtp) has a very promising potential for adsorption and storage of alkanes. This work was supported by the US Department of Energy Basic Energy Sciences' Chemical Sciences, Geosciences & Biosciences Division. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  12. Stability of precipitate phases in Fe-rich Fe-Cr-Ni-Mo alloys

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yang, Ying; Tan, Lizhen; Busby, Jeremy T

    2015-01-01

    Understanding the stability of precipitate phases in the Fe-rich Fe-Cr-Ni-Mo alloys is critical to the alloy design and application of Mo-containing Austenitic steels. Coupled with thermodynamic modeling, stability of the and phases in two Fe-Cr-Ni-Mo alloys were investigated at 1000, 850 and 700 C for different annealing time. The morphologies, compositions and crystal structures of the matrix and precipitate phases were carefully examined by Scanning Electron Microscopy, Electron Probe Microanalysis, X-ray diffraction and Transmission Electron Microscopy. Two key findings resulted from this work. One is that the phase is stable at high temperature and transformed into the phase at lowmore »temperature. The other is that both the and phases have large solubilites of Cr, Mo and Ni, among which the Mo solubility has a major role on the relative stability of the precipitate phases. The developed thermodynamic models were then applied to evaluating the Mo effect on the stability of precipitate phases in AISI 316 and NF709 alloys.« less

  13. Bulk amorphous Pd{endash}Ni{endash}Fe{endash}P alloys: Preparation and characterization

    SciTech Connect (OSTI)

    Shen, T.D.; He, Y.; Schwarz, R.B. [Materials Science and Technology Division, MS K765, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    1999-05-01

    Bulk amorphous alloys of Pd{sub x}Ni{sub y}Fe{sub 80{minus}x{minus}y}P{sub 20} (25{le}x{le}60, 20{le}y{le}55, x+y{ge}60) were prepared by a flux-melting and water-quenching method. Seven-mm diameter glassy rods of Pd{sub 40}Ni{sub 40{minus}x}Fe{sub x}P{sub 20} (0{le}x{le}20) were studied in greater detail. For these alloys, the difference between the crystallization and glass transition temperatures ranges from 102 K for x=0 to 53 K for x=20. In this composition range, the reduced glass transition temperature, T{sub rg}, ranges from 0.66 to 0.57. The change in density upon crystallization ranges from 0.24{plus_minus}0.04{percent} for x=0 to 1.33{plus_minus}0.24{percent} for x=10. The partial molar volume of Fe in amorphous Pd{sub 40}Ni{sub 40{minus}x}Fe{sub x}P{sub 20} alloys is significantly larger than the molar volume of (metastable) fcc Fe. This, as well as a comparison with the molar volumes of crystalline compounds, suggests chemically selective Fe{endash}Pd bonding in these glasses. {copyright} {ital 1999 Materials Research Society.}

  14. Laser power beaming to extend lives of GSO NiCd satellites

    SciTech Connect (OSTI)

    Monroe, D.K.

    1993-12-31

    It is proposed that a ground-based laser can beam power to commercial communication satellites in geosynchronous orbit and reduce battery depth-of-discharge during eclipses. Two laser system designs are presented which have the capability of reducing battery discharge by 100%. Both utilize a steerable beam director, with a mirror diameter of 4 meters in one case and 8 meters in the other. Both also use an adaptive optics unit within the beam train to provide real-time corrections for wavefront distortions caused by atmospheric turbulence. The required system power output is in the range of 100 to 200 kW for a transmitted wavelength just under 900 nm. Laser power beaming can nearly double the remaining lifetime of a satellite that uses NiCd batteries. However, by the time such lasers become available, nearly all NiCd satellites will be replaced by NiH{sub 2} satellites, which stand to benefit much less from power beaming.

  15. Thermal stability of intermetallic phases in Fe-rich Fe-Cr-Ni-Mo alloys

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yang, Ying; Tan, Lizhen; Busby, Jeremy T.

    2015-06-12

    Understanding the stability of precipitate phases in the Fe-rich Fe-Cr-Ni-Mo alloys is critical to the alloy design and application of Mo-containing Austenitic steels. Coupled with thermodynamic modeling, stability of the chi and Laves phases in two Fe-Cr-Ni-Mo alloys were investigated at 1000, 850 and 700 °C for different annealing time. The morphologies, compositions and crystal structures of the matrix and precipitate phases were carefully examined by Scanning Electron Microscopy, Electron Probe Microanalysis, X-ray diffraction and Transmission Electron Microscopy. The two key findings resulted from this work. One is that the chi phase is stable at high temperature and transformed intomore »the Laves phase at low temperature. The other is that both the chi and Laves phases have large solubilites of Cr, Mo and Ni, among which the Mo solubility has a major role on the relative stability of the precipitate phases. The developed thermodynamic models were then applied to evaluating the Mo effect on the stability of precipitate phases in AISI 316 and NF709 alloys.« less

  16. High Energy Density Na-S/NiCl2 Hybrid Battery

    SciTech Connect (OSTI)

    Lu, Xiaochuan; Lemmon, John P.; Kim, Jin Yong; Sprenkle, Vincent L.; Yang, Zhenguo

    2013-02-15

    High temperature (250-350°C) sodium-beta alumina batteries (NBBs) are attractive energy storage devices for renewable energy integration and other grid related applications. Currently, two technologies are commercially available in NBBs, e.g., sodium-sulfur (Na-S) battery and sodium-metal halide (ZEBRA) batteries. In this study, we investigated the combination of these two chemistries with a mixed cathode. In particular, the cathode of the cell consisted of molten NaAlCl4 as a catholyte and a mixture of Ni, NaCl and Na2S as active materials. During cycling, two reversible plateaus were observed in cell voltage profiles, which matched electrochemical reactions for Na-S and Na-NiCl2 redox couples. An irreversible reaction between sulfur species and Ni was identified during initial charge at 280°C, which caused a decrease in cell capacity. The final products on discharge included Na2Sn with 1< n < 3, which differed from Na2S3 found in traditional Na-S battery. Reduction of sulfur in the mixed cathode led to an increase in overall energy density over ZEBRA batteries. Despite of the initial drop in cell capacity, the mixed cathode demonstrated relatively stable cycling with more than 95% of capacity retained over 60 cycles under 10mA/cm2. Optimization of the cathode may lead to further improvements in battery performance.

  17. Improved phenomenological description of equilibrium charge state distributions for Ni, Co, and Cu ions in Mo based on new experimental data at 2 MeV/u

    E-Print Network [OSTI]

    P. Gastis; G. Perdikakis; D. Robertson; R. Almus; T. Anderson; W. Bauder; P. Collon; W. Lu; K. Ostdiek; M. Skulski

    2015-09-24

    Equilibrium charge state distributions of stable 60Ni, 59Co, and 63Cu beams passing through a 1um thick Mo foil were measured at beam energies of 1.84 MeV/u, 2.09 MeV/u, and 2.11 MeV/u respectively. A 1-D position sensitive Parallel Grid Avalanche Counter detector (PGAC) was used at the exit of a spectrograph magnet, enabling us to measure the intensity of several charge states simultaneously. The number of charge states measured for each beam constituted more than 99% of the total equilibrium charge state distribution for that elements. Currently, little experimental data exists for equilibrium charge state distributions for heavy ions with 1954 (Zp and Zt, are the projectile's and target's atomic numbers respectively). Hence the success of the semi-empirical models in predicting typical characteristics of equilibrium CSDs (mean charge states and distribution widths), has not been thoroughly tested at the energy region of interest. A number of semi-empirical models from the literature were evaluated in this study, regarding their ability to reproduce the characteristics of the measured charge state distributions. The evaluated models were selected from the literature based on whether they are suitable for the given range of atomic numbers and on their frequent use by the nuclear physics community. Finally, an attempt was made to combine model predictions for the mean charge state, the distribution width and the distribution shape, to come up with a more reliable model. We discuss this new "combinatorial" prescription and compare its results with our experimental data and with calculations using the other semi-empirical models studied in this work.

  18. O Uso de uma Arquitetura Baseada em Componentes para Incrementar um Servio do Ambiente AulaNet

    E-Print Network [OSTI]

    Barbosa, Alberto

    O Uso de uma Arquitetura Baseada em Componentes para Incrementar um Serviço do Ambiente Aula de ensino-aprendizagem AulaNet. Palavras-chave: Componentes de colaboração, arquitetura componentizada, aprendizagem colaborativa. 1. Introdução Um groupware envolve aspectos multidisciplinares em sua

  19. Simplifying strong electronic correlations in uranium: Localized uranium heavy-fermion UM2Zn20 (M=Co,Rh) compounds

    E-Print Network [OSTI]

    Lawrence, Jon

    Simplifying strong electronic correlations in uranium: Localized uranium heavy-fermion UM2Zn20 (M Atómica, 8400 Bariloche, Argentina 6 Department of Chemistry and Biochemistry, University of Delaware-field effects corroborate an ionic-like uranium electronic configura- tion in UM2Zn20. DOI: 10.1103/PhysRevB.78

  20. Seat Belt Use Policy Outline the policy regarding use of seat belt in University of Michigan (U-M) vehicles.

    E-Print Network [OSTI]

    Kirschner, Denise

    Seat Belt Use Policy Objective Outline the policy regarding use of seat belt in University belt when operating a U-M vehicle. 2. Operators are also required to ensure that all occupants are adhering to the seat belt use laws when operating a U-M vehicle. 3. State of Michigan seat belt laws

  1. Tribological properties of self-lubricating NiAl/Mo-based composites containing AgVO{sub 3} nanowires

    SciTech Connect (OSTI)

    Liu, Eryong; Gao, Yimin; Bai, Yaping; Yi, Gewen; Wang, Wenzhen; Zeng, Zhixiang; Jia, Junhong

    2014-11-15

    Silver vanadate (AgVO{sub 3}) nanowires were synthesized by hydrothermal method and self-lubricating NiAl/Mo-AgVO{sub 3} composites were fabricated by powder metallurgy technique. The composition and microstructure of NiAl/Mo-based composites were characterized and the tribological properties were investigated from room temperature to 900 °C. The results showed that NiAl/Mo-based composites were consisted of nanocrystalline B2 ordered NiAl matrix, Al{sub 2}O{sub 3}, Mo{sub 2}C, metallic Ag and vanadium oxide phase. The appearance of metallic Ag and vanadium oxide phase can be attributed to the decomposition of AgVO{sub 3} during sintering. Wear testing results confirmed that NiAl/Mo-based composites have excellent tribological properties over a wide temperature range. For example, the friction coefficient and wear rate of NiAl/Mo-based composites containing AgVO{sub 3} were significantly lower than the composites containing only metallic Mo or AgVO{sub 3} lubricant when the temperature is above 300 °C, which can be attributed to the synergistic lubricating action of metallic Mo and AgVO{sub 3} lubricants. Furthermore, Raman results indicated that the composition on the worn surface of NiAl-based composites was self-adjusted after wear testing at different temperatures. For example, Ag{sub 3}VO{sub 4} and Fe{sub 3}O{sub 4} lubricants were responsible for the improvement of tribological properties at 500 °C, AgVO{sub 3}, Ag{sub 3}VO{sub 4} and molybdate for 700 °C, and AgVO{sub 3} and molybdate for 900 °C of NiAl-based composites with the addition of metallic Mo and AgVO{sub 3}. - Highlights: • NiAl/Mo-AgVO{sub 3} nanocomposites were prepared by mechanical alloying and sintering. • AgVO{sub 3} decomposed to metallic Ag and vanadium oxide during the sintering process. • NiAl/Mo-AgVO{sub 3} exhibited superior tribological properties at a board temperature range. • Phase composition on the worn surface was varied with temperatures. • Self-adjusted action was responsible for the improvement of tribological properties.

  2. Characterization of Ultrathin Films of -Al2O3 and the Chemistry of 1,3-Butadiene on NiAl(001) and -Al2O3

    E-Print Network [OSTI]

    Characterization of Ultrathin Films of -Al2O3 and the Chemistry of 1,3-Butadiene on NiAl(001 by warming above 210 K. Adsorption and reaction of 1,3-butadiene on NiAl(001), and thin films of -Al2O3, have (LID-FTMS), AES, and LEED. We find that at 170 K, the 1,3-butadiene is irreversibly -bonded to NiAl(001

  3. Effect of pulse frequency on microstructural, nanomechanical, and wear properties of electrodeposited Ni–TiN composite coatings

    SciTech Connect (OSTI)

    Xia, Fafeng; Tian, Jiyu; Ma, Chunyang Guo, Xue; Potts, Matt

    2014-12-21

    The current paper reports successful syntheses of Ni–TiN composite coatings by pulse electrodeposition. The effect of pulse frequency on the microstructures, nanomechanical, and wear properties of the coatings was investigated using transmission electron microscopy, X–ray diffraction, nanoindenter, scanning electron microscopy, and wear test instrument. The results showed that the Ni–TiN composite coating prepared at the pulse frequency of 100?Hz showed the presence of a less number of TiN particles and some degrees of aggregation in micro-regions. By contrast, in the Ni–TiN coating deposited at the pulse frequency of 500?Hz, the TiN particles were large in number and dispersed homogeneously, thereby, offering the coating a uniform and fine structure. The average grain diameters of Ni and TiN in the coating prepared at 100?Hz were 154.7 and 44.8?nm, respectively, whereas those for the coating prepared at 500?Hz were 67.3 and 25.9?nm, respectively. The maximum TiN content in the Ni-TiN coating deposited at 800?Hz was approximately 10.5?wt.?%. The maximum microhardness and the Young's modulus values for the Ni–TiN composite coatings deposited at 800?Hz were 35.7?GPa and 167.4?GPa, respectively. Furthermore, the Ni–TiN composite coating prepared at 100?Hz had more severe damages, whereas the morphologies of worn surface of the coatings deposited at 500?Hz and 800?Hz were smooth and only a few small pits appeared on the surface.

  4. Microstructure degradation of YSZ in Ni/YSZ anodes of SOFC operated in phosphine-containing fuels

    SciTech Connect (OSTI)

    Chen, Yun; Chen, Song; Hackett, Gregory; Finklea, Harry; Zondlod, John; Celik, Ismail; Song, Xueyan; Gerdes, Kirk

    2013-03-07

    The interaction of trace (ppm) phosphine with the nickel/yttria stabilized zirconia (YSZ) anode of commercial solid oxide fuel cells has been investigated and evaluated for both synthesis gas and hydrogen fuels in an effort to examine P–Y reactions. The Ni poisoning effects reported in literature were confirmed and degradation was examined by electrochemical methods and post-test microstructural and chemical analyses. The results indicate that P-induced degradation rates and mechanisms are fuel dependent and that degradation of cells operated in synthesis gas (syngas) with phosphine is more severe than that of cells operated in hydrogen with phosphine. As reported in published literature, a cell operated in syngas containing 10 ppm phosphine demonstrated significant microstructural degradation within the Ni phase, including formation of Ni–P phases concentrated on the outer layer of the anode and significant pitting corrosion in the Ni grains. In this research, a previously undetected YPO{sub 4} phase is observed at the YSZ/YSZ/Ni triple grain junctions located at the interface with the YSZ electrolyte. Tetragonal YSZ (t-YSZ) and cubic-YSZ (c-YSZ) domains with sizes of several tens of nanometers are also newly observed along the Ni/YSZ interface. These observations contrast with data obtained for a cell operated in dry hydrogen with phosphine, where no YPO{sub 4} phase is observed and the alternating t-YSZ and c-YSZ domains at the Ni/YSZ interface are smaller with typical sizes of 5–10 nm. The data imply that electrolyte attack by P is a potentially debilitating mode of degradation in SOFC anodes, and that the associated reaction mechanisms and rates are worthy of further examination.

  5. Hydrocracking of n-decane over zeolite-supported metal sulfide catalysts. 2: Zeolite Y-supported Ni and Ni-Mo sulfides

    SciTech Connect (OSTI)

    Welters, W.J.J.; Waerden, O.H. van der; Beer, V.H.J. de; Santen, R.A. van [Eindhoven Univ. of Technology (Netherlands). Schuit Inst. of Catalysis

    1995-04-01

    For zeolite Y-supported nickel sulfide catalysts the influence of the metal sulfide dispersion on the hydrocracking properties for n-decane is examined. In order to obtain different nickel sulfide distributions (inside or outside the zeolite structure) and dispersions, the preparation method (impregnation of CaY or ion exchange of NaY), sulfidation procedure (direct sulfidation or sulfidation after drying), and metal loading are varied. A higher nickel sulfide surface (as measured by dynamic oxygen chemisorption) results in a strong increase of the n-decane conversion, but this is not accompanied by an improvement of the catalytic properties toward ideal hydrocracking. Additionally, some zeolite Y-supported Ni-Mo sulfide catalysts (varying in preparation method and sulfidation procedure) are tested for the hydroconversion of it-decane. However, no promoter effect could be observed. The activity of the bimetallic sulfide catalysts is always almost equal to that of the most active monometallic sulfide constituent.

  6. High-pressure stability relations, crystal structures, and physical properties of perovskite and post-perovskite of NaNiF{sub 3}

    SciTech Connect (OSTI)

    Shirako, Y.; Shi, Y.G.; Aimi, A.; Mori, D.; Kojitani, H.; Yamaura, K.; Inaguma, Y.; Akaogi, M.

    2012-07-15

    NaNiF{sub 3} perovskite was found to transform to post-perovskite at 16-18 GPa and 1273-1473 K. The equilibrium transition boundary is expressed as P (GPa)=-2.0+0.014 Multiplication-Sign T (K). Structure refinements indicated that NaNiF{sub 3} perovskite and post-perovskite have almost regular NiF{sub 6} octahedra consistent with absence of the first-order Jahn-Teller active ions. Both NaNiF{sub 3} perovskite and post-perovskite are insulators. The perovskite underwent a canted antiferromagnetic transition at 156 K, and the post-perovskite antiferromagnetic transition at 22 K. Magnetic exchange interaction of NaNiF{sub 3} post-perovskite is smaller than that of perovskite, reflecting larger distortion of Ni-F-Ni network and lower dimension of octahedral arrangement in post-perovskite than those in perovskite. - Graphical abstract: Perovskite-post-perovskite transition in NaNiF{sub 3} at high pressure Highlights: Black-Right-Pointing-Pointer NaNiF{sub 3} perovskite (Pv) transforms to post-perovskite (pPv) at 16 GPa and 1300 K. Black-Right-Pointing-Pointer The equilibrium transition boundary is expressed as P (GPa)=-2.0+0.014 T (K). Black-Right-Pointing-Pointer Antiferromagnetic transition occurs at 156 K in Pv and 22 K in pPv.

  7. Effect of modifier Pd metal on hydrocracking of polyaromatic compounds over Ni-loaded Y-type zeolite and its application as hydrocracking of polyaromatic compounds over Ni-loaded Y-type zeolite and its application as hydrodesulfurization catalysts

    SciTech Connect (OSTI)

    Wada, T.; Murata, S.; Nomura, M. [Osaka Univ. (Japan)

    1995-12-31

    We have been studying the hydrocracking of polyaromatic compounds over Ni-loaded zeolite catalysts (ZSM-5, mordenite, and Y-type) and found the fact that pore size of zeolite exerts an interesting effect on product distribution. In this study, we have conducted the hydrocracking of pyrene using Pd-modified Ni-loaded Y-type zeolite as catalyst. Addition of Pd-metal activated Ni-loaded Y-type zeolite at a great extent. 100% conversion of pyrene was attained under milder conditions like at 325{degrees}C for 1 h (H{sub 2} 70 kg/cm{sup 2}) while Ni-loaded Y-type zeolite can attain 100% conversion at 350{degrees}C for 1 h. Detailed analysis of product distribution suggested us to apply this catalyst for the hydrodesulfurization of dibenzothiophene. We have conducted hydrocracking of dibenzothiophene at 300{degrees}C for 1 h and found that almost all of dibenzothiophene was hydrocracked while both Ni-loaded Y-type zeolite and Pd-loaded Y-type zeolite show about 10-15% of starting materials remained. This result clearly indicates that modifier Pd-metal shows a kind of synergy for hydrodesulfurization of dibenzothiophene.

  8. Rare-earth-rich tellurides: Gd{sub 4}NiTe{sub 2} and Er{sub 5}M{sub 2}Te{sub 2} (M=Co, Ni)

    SciTech Connect (OSTI)

    Magliocchi, Carmela; Meng, Fanqin; Hughbanks, Timothy . E-mail: trh@mail.chem.tamu.edu

    2004-11-01

    Three new rare earth metal-rich compounds, Gd{sub 4}NiTe{sub 2}, and Er{sub 5}M{sub 2}Te{sub 2} (M=Ni, Co), were synthesized in direct reactions using R, R{sub 3}M, and R{sub 2}Te{sub 3} (R=Gd, Er; M=Co, Ni) and single-crystal structures were determined. Gd{sub 4}NiTe{sub 2} is orthorhombic and crystallizes in space group Pnma with four formula units per cell. Lattice parameters at 110(2)K are a=15.548(9), b=4.113(2), c=11.7521(15)A. Er{sub 5}Ni{sub 2}Te{sub 2} and Er{sub 5}Co{sub 2}Te{sub 2} are isostructural and crystallize in the orthorhombic space group Cmcm with two formula units per cell. Lattice parameters at 110(2)K are a=3.934(1), b=14.811(4), c=14.709(4)A, and a=3.898(1), b=14.920(3), c=14.889(3)A, respectively. Metal-metal bonding correlations were analyzed using the empirical Pauling bond order concept.

  9. /SETA~1niEssl MECHANISTIC QUANTITATIVE STRUCTURE-ACTIVITY RELATIONSHIP MODEL FOR

    E-Print Network [OSTI]

    Krylov, Sergey

    Bibbo) in simulated solar radiation (SSR) was developed. UmMl Bibbo was chosenfor this study, the fluenc\\: rate of actinic radiation is lower within leaves than in the aqueousphase,and the toxicity yield for formation of triplet-state PAH, and rate of PAR photomodHication. Data for growth

  10. Characterization of Ni-Fe/Si{sub 3}N{sub 4} Nanocomposite Coatings Deposited by Electroplating

    SciTech Connect (OSTI)

    Marita, Yusrini; Yaacob, Iskandar Idris [Center for Nanotechnology, Precision and Advanced Materials, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2009-05-27

    Ni-Fe/Si{sub 3}N{sub 4} nanocomposite coatings with various amount of Si{sub 3}N{sub 4} were prepared by electrodeposition technique. The effect of Si{sub 3}N{sub 4} nanoparticulates in the Ni-Fe nanocomposite coatings was investigated in relation to the ratio of Si{sub 3}N{sub 4} to Na-saccharine in the plating bath. X-ray diffraction analysis showed that the Ni-Fe nanocomposite coating has face-centered cubic structure (FCC). However, a mixture of body-centered cubic (BCC) and face-centered cubic (FCC) phases was observed when the ratio of Si{sub 3}N{sub 4} to Na-saccharine was around 8.3. The crystallite size of the Ni-Fe nanocomposite coating decreased when the ratio of Si{sub 3}N{sub 4} to Na-saccharine was increased. From the results of the elemental mapping procedure, it was found that inclusions of silicon were uniformly distributed in Ni-Fe composite coating, indicating good dispersion of Si{sub 3}N{sub 4} and this contributed in increasing the microhardness of coating.

  11. Microstructural and chemical evolution near anode triple phase boundary in Ni/YSZ solid oxide fuel cells

    SciTech Connect (OSTI)

    Chen, Yun; Chen, Song; Hackett, Gregory; Finklea, Harry; Song, Xueyan; Gerdes, Kirk

    2011-12-12

    In this study, we report the micro-structural and chemical evolution of anode grain boundaries and triple phase boundary (TPB) junctions of Ni/YSZ anode supported solid oxide fuel cells. A NiO phase was found to develop along the Ni/YSZ interfaces extending to TPBs in the operated cells. The thickness of the NiO ribbon phase remains constant at ~ 5 nm in hydrogen for operating durations up to 540 h. When operating on synthesis gas, an increase in interphase thickness was observed from ~ 11 nm for 24 h of operation to ~ 51 nm for 550 h of operation. YSZ phases are observed to be stable in H{sub 2} over 540 h of operation. However, for the cell operated in syngas for 550 h, a 5–10 nm tetragonal YSZ (t-YSZ) interfacial layer was identified that originated from the Ni/YSZ interfaces. Yttrium species seem to segregate to the interfaces during operation, leading to the formation of t-YSZ in the Y-depleted regions.

  12. Magnetic properties and transmission electron microscopy studies of Ni nanoparticles encapsulated in carbon nanocages and carbon nanotubes

    SciTech Connect (OSTI)

    He Chunnian; Zhao Naiqin Shi Chunsheng; Li Jiajun; Li Haipeng

    2008-08-04

    Three types of carbon nanomaterials, including bamboo-shaped carbon nanotubes with Ni encapsulated and hollow and Ni catalytic particles filled carbon nanocages, have been prepared by methane catalytic decomposition at a relatively low temperature. Transmission electron microscopy observations showed that fascinating fullerene-like Ni-C (graphitic) core-shell nanostructures predominated. Detailed examination of high-resolution transmission electron microscopy showed that the walls of bamboo-shaped carbon nanotubes with quasi-cone catalytic particles encapsulated consisted of oblique graphene planes with respect to the tube axis. The Ni particles encapsulated in the carbon nanocages were larger than that encapsulated in carbon nanotubes, but the diameters of the cores of hollow carbon nanocages were less than that of Ni particles encapsulated in carbon nanotubes, suggesting that the sizes of catalyst particles played an important role during carbon nanomaterial growth. The magnetic properties of the carbon nanomaterials were measured, which showed relatively large coercive force (H{sub c} = 138.4 O{sub e}) and good ferromagnetism (M{sub r}/M{sub s} = 0.325)

  13. Features of an intermetallic n-ZrNiSn semiconductor heavily doped with atoms of rare-earth metals

    SciTech Connect (OSTI)

    Romaka, V. A., E-mail: vromaka@polynet.lviv.ua [National Academy of Sciences of Ukraine, Ya. Pidstryhach Institute for Applied Problems of Mechanics and Mathematics (Ukraine); Fruchart, D.; Hlil, E. K. [CNRS, Institute Neel (France); Gladyshevskii, R. E. [Ivan Franko Lviv National University (Ukraine); Gignoux, D. [CNRS, Institute Neel (France); Romaka, V. V.; Kuzhel, B. S. [Ivan Franko Lviv National University (Ukraine); Krayjvskii, R. V. [Lvivska Politechnika National University (Ukraine)

    2010-03-15

    The crystal structure, density of electron states, electron transport, and magnetic characteristics of an intermetallic n-ZrNiSn semiconductor heavily doped with atoms of rare-earth metals (R) have been studied in the ranges of temperatures 1.5-400 K, concentrations of rare-earth metal 9.5 x 10{sup 19}-9.5 x 10{sup 21} cm{sup -3}, and magnetic fields H {<=} 15 T. The regions of existence of Zr{sub 1-x}R{sub x}NiSn solid solutions are determined, criteria for solubility of atoms of rare-earth metals in ZrNiSn and for the insulator-metal transition are formulated, and the nature of 'a priori doping' of ZrNiSn is determined as a result of redistribution of Zr and Ni atoms at the crystallographic sites of Zr. Correlation between the concentration of the R impurity, the amplitude of modulation of the bands of continuous energies, and the degree of occupation of potential wells of small-scale fluctuations with charge carriers is established. The results are discussed in the context of the Shklovskii-Efros model of a heavily doped and compensated semiconductor.

  14. Influence of fabrication technique on the fiber pushout behavior in a sapphire-reinforced NiAl matrix composite

    SciTech Connect (OSTI)

    Asthana, R.; Bowman, R.R. . Materials Division); Tewari, S.N. )

    1995-01-01

    Directional solidification (DS) of powder-cloth'' (PC) processed sapphire-NiAl composites was carried out to examined the influence of fabrication technique on the fiber-matrix interfacial shear strength, measured using a fiber-pushout technique. The DS process replaced the fine, equiaxed NiAl grain structure of the PC composites with an oriented grain structure comprised of large columnar NiAl grains aligned parallel to the fiber axis, with fibers either completely engulfed within the NiAl grains or anchored at one to three grain boundaries. The load-displacement behavior during the pushout test exhibited an initial pseudoelastic'' response, followed by an inelastic'' response, and finally a frictional'' sliding response. The fiber-matrix interfacial shear strength and the fracture behavior during fiber pushout were investigated using an interrupted pushout test and fractography, as functions of specimen thickness and fabrication technique. The composites fabricated using the PC and the DS techniques had different matrix and interface structures and appreciably different interfacial shear strengths. In the DS composites, where the fiber-matrix interfaces were identical for all the fibers, the interfacial debond shear stresses were larger for the fibers embedded completely within the NiAl grains and smaller for the fibers anchored at a few grain boundaries. The matrix grain boundaries coincident on sapphire fibers were observed to be the preferred sties for crack formation and propagation.

  15. Effect of Sodium Sulfide on Ni-Containing Carbon Monoxide Dehydrogenases

    SciTech Connect (OSTI)

    Jian Feng; Paul A. Lindahl

    2004-07-28

    OAK-B135 The structure of the active-site C-cluster in CO dehydrogenase from Carboxythermus hydrogenoformans includes a {mu}{sup 2}-sulfide ion bridged to the Ni and unique Fe, while the same cluster in enzymes from Rhodospirillum rubrum (CODH{sub Rr}) and Moorella thermoacetica (CODH{sub Mt}) lack this ion. This difference was investigated by exploring the effects of sodium sulfide on activity and spectral properties. Sulfide partially inhibited the CO oxidation activity of CODH{sub Rr} and generated a lag prior to steady-state. CODH{sub Mt} was inhibited similarly but without a lag. Adding sulfide to CODH{sub Mt} in the C{sub red1} state caused the g{sub av} = 1.82 EPR signal to decline and new features to appear, including one with g = 1.95, 1.85 and (1.70 or 1.62). Removing sulfide caused the g{sub av} = 1.82 signal to reappear and activity to recover. Sulfide did not affect the g{sub av} = 1.86 signal from the C{sub red2} state. A model was developed in which sulfide binds reversibly to C{sub red1}, inhibiting catalysis. Reducing this adduct causes sulfide to dissociate, C{sub red2} to develop, and activity to recover. Using this model, apparent K{sub I} values are 40 {+-} 10 nM for CODH{sub Rr} and 60 {+-} 30 {micro}M for CODH{sub Mt}. Effects of sulfide are analogous to those of other anions, including the substrate hydroxyl group, suggesting that these ions also bridge the Ni and unique Fe. This proposed arrangement raises the possibility that CO binding labilizes the bridging hydroxyl and increases its nucleophilic tendency towards attacking Ni-bound carbonyl.

  16. Development and Test Evaluations for Ni-DOBDC Metal Organic Framework (MOF) Engineered Forms

    SciTech Connect (OSTI)

    Troy G. Garn; Mitchell Greenhalgh

    2013-07-01

    A joint effort to prepare engineered forms of a Ni-DOBDC metal organic framework (MOF) was completed with contributions from PNNL, SNL and the INL. Two independent methods were used at INL and SNL to prepare engineered form (EF) sorbents from Ni-DOBDC MOF powder developed and prepared at PNNL. Xe and Kr capacity test evaluations were performed at ambient temperature with the cryostat experimental setup at INL. The initial INL EF MOF test results indicated a Xe capacity of 1.6 mmol/kg sorbent and no Kr capacity. A large loss of surface area also occurred during minimal testing rendering the INL EF MOF unusable. Four capacity tests were completed using the SNL EF MOF at ambient temperature and resulted in Xe capacities of 1.4, 4.2, 5.0 and 3.8 mmol/kg sorbent with no Kr capacity observed in any ambient temperature tests. Two additional capacity tests were performed at 240 K to further evaluate SNL EF MOF performance. Xe capacities of 50.7 and 49.3 mmol/kg of sorbent and Kr capacities of 0.77 and 0.69 mmol/kg of sorbent were obtained, respectively. Following the adsorption evaluations, the SNL EF MOF material had lost about 40 % of the initial mass and 40 % of the initial surface area. In general, the Xe capacity results at ambient temperature for the INL and SNL EF Ni-DOBDC MOF’s were lower than 9.8 mmol Xe/kg sorbent test results reported by INL in FY-12 using PNNL’s inital EF supplied material.

  17. Thermal aging modeling and validation on the Mo containing Fe-Cr-Ni alloys

    SciTech Connect (OSTI)

    Yang, Ying; Tan, Lizhen; Busby, Jeremy T.

    2015-04-01

    Thermodynamics of intermetallic phases in Fe-rich Fe-Cr-Ni-Mo alloys is critical knowledge to understand thermal aging effect on the phase stability of Mo-containing austenitic steels, which subsequently facilitates alloy design/improvement and degradation mitigation of these materials for reactor applications. Among the intermetallic phases, Chi (?), Laves, and Sigma (?) are often of concern because of their tendency to cause embrittlement of the materials. The focus of this study is thermal stability of the Chi and Laves phases as they were less studied compared to the Sigma phase. Coupled with thermodynamic modeling, thermal stability of intermetallic phases in Mo containing Fe-Cr-Ni alloys was investigated at 1000, 850 and 700 C for different annealing times. The morphologies, compositions and crystal structures of the precipitates of the intermetallic phases were carefully examined by scanning electron microscopy, electron probe microanalysis, X-ray diffraction, and transmission electron microscopy. Three key findings resulted from this study. First, the Chi phase is stable at high temperature, and with decreasing temperature it transforms into the Laves phase that is stable at low temperature. Secondly, Cr, Mo, Ni are soluble in both the Chi and Laves phases, with the solubility of Mo playing a major role in the relative stability of the intermetallic phases. Thirdly, in situ transformation from Chi phase to Laves phase was directly observed, which increased the local strain field, generated dislocations in the intermetallic phases, and altered the precipitate phase orientation relationship with the austenitic matrix. The thermodynamic models that were developed and validated were then applied to evaluating the effect of Mo on the thermal stability of intermetallic phases in type 316 and NF709 stainless steels.

  18. Quantum spin coherence in halogen-modified Cr$_7$Ni molecular nanomagnets

    E-Print Network [OSTI]

    Danielle Kaminski; Amy L. Webber; Christopher J. Wedge; Junjie Liu; Grigore A. Timco; Inigo J. Vitorica-Yrezabal; Eric J. L. McInnes; Richard E. P. Winpenny; Arzhang Ardavan

    2014-10-30

    Among the factors determining the quantum coherence of the spin in molecular magnets is the presence and the nature of nuclear spins in the molecule. We have explored modifying the nuclear spin environment in Cr$_7$Ni-based molecular nanomagnets by replacing hydrogen atoms with deuterium or the halogen atoms, fluorine or chlorine. We find that the spin coherence, studied at low temperatures by pulsed electron spin resonance, is modified by a range of factors, including nuclear spin and magnetic moment, changes in dynamics owing to nuclear mass, and molecular morphology changes.

  19. Photocatalytic Hydrogen Production using Polymeric Carbon Nitride with a Hydrogenase and a Bioinspired Synthetic Ni Catalyst

    E-Print Network [OSTI]

    Caputo, Christine A.; Gross, Manuela A.; Lau, Vincent W.; Cavazza, Christine; Lotsch, Bettina V.; Reisner, Erwin

    2014-09-09

    groups which, much like those found in the active site of [FeFe]-H2ases,[8] can act as catalytically active proton relays in the second coordination sphere of the 3d metal center. To date, photocatalytic H2 generation with a Ni-bis(diphosphine) catalyst... of approximately 7×10-2 %, whereas an EQE of 5×10–3 % was obtained at ? = 465 nm (Figure S8). A centrifugation test was performed to gain insight into the strength of interaction between the enzyme and CNx particles. First, H2 production was monitored for 2 h...

  20. Elastic Constants of Ni-Mn-Ga Magnetic Shape Memory Alloys

    SciTech Connect (OSTI)

    Stipcich, M. [Universitat de Barcelona; Manosa, L. [Universitat de Barcelona; Planes, A. [Universitat de Barcelona; Morin, M. [INSA de Lyon; Zarestky, Jerel L [ORNL; Lograsso, Tom [Ames Laboratory; Stassis, C. [Ames Laboratory

    2004-01-01

    We have measured the adiabatic second order elastic constants of two Ni-Mn-Ga magnetic shape memory crystals with different martensitic transition temperatures, using ultrasonic methods. The temperature dependence of the elastic constants has been followed across the ferromagnetic transition and down to the martensitic transition temperature. Within experimental errors no noticeable change in any of the elastic constants has been observed at the Curie point. The temperature dependence of the shear elastic constant C' has been found to be very different for the two alloys. Such a different behavior is in agreement with recent theoretical predictions for systems undergoing multi-stage structural transitions.

  1. Comment on the Evidence for a Monopole Resonance at Approximately 20 Mev in Ni-58 

    E-Print Network [OSTI]

    Garg, U.; Bogucki, P.; Bronson, J. D.; Lui, YW; Rozsa, C. M.; Youngblood, David H.

    1982-01-01

    and a keyword abstract. Comment on the evidence for a monopole resonance at approximately 20 MeV in 5sNi U. Garg, P. Bogucki, J. D. Bronson, Y. -W. Lui, C. M. Rozsa, * and D. H. Youngblood Cyclotron Institute, Texas AckM Uniuersity, College Station.... Rozsa, D. H. Youngblood, J. D. Bronson, Y.-W. Lui, and U. Garg, Phys. Rev. C +1, 1252 (1980). SD. C. Kocher, F. E. Bertrand, E. E. Gross, and E. New- man, Phys. Rev. C 14, 1392 (1976). Y.-W. Lui, P. Bogucki, J. D. Bronson, U. Garg, C. M. Rozsa...

  2. Effect of Substrate Configuration on the Grain Structure and Morphology of Electrodeposited Ni for Prototyping LIGA

    SciTech Connect (OSTI)

    Nacy Y. C. Yang

    2002-07-01

    Synchrotron X-ray lithographic molding of PMMA-Ti/Cu/Ti substrates has been developed and used in the electrodeposition of Ni microparts for prototype LIGA development at SNL, CA. Alternative molding processes that minimize x-ray beam line use and reduce processing time are of interest for the rapid fabrication of large quantities of microparts. The objective of this investigation is to examine, archive, and compare the grain structure and morphology of deposits produced from four different molding technologies currently under development. We conclude that deposit microstructure and uniformity are greatly influenced by substrate material and design configuration. The findings are summarized.

  3. Sintering atmosphere effects on the ductility of W-Ni-Fe heavy metals

    SciTech Connect (OSTI)

    German, R.M.; Churn, K.S.

    1984-04-01

    Residual porosity has a strong negative effect on the ductility of tungsten-nickel-iron heavy metals. This investigation examined the sintering atmosphere role in stabilizing detrimental residual pore structures. Experiments are reported on alloys containing 93, 95, or 97 wt pct W with Ni:Fe ratios of 7:3. The negative effect of prolonged sintering is attributed to pore coarsening involving trapped gas. Calculated pore growth rates for hydrogen filled pores suggest that pore coarsening involves both ripening and coalescence driven by tungsten grain growth. A change in sintering atmosphere from hydrogen to argon midway through the sintering cycle can aid pore degassing and increase ductility and strength.

  4. Corrosion and degradation of a polyurethane/Co-Ni-Cr-Mo pacemaker lead

    SciTech Connect (OSTI)

    Sung, P.; Fraker, A.C.

    1987-12-01

    An investigation to study changes in the metal surfaces and the polyurethane insulation of heart pacemaker leads under controlled in vitro conditions was conducted. A polyurethane (Pellethane 2363-80A)/Co-Ni-Cr-Mo (MP35N) wire lead was exposed in Hanks' physiological saline solution for 14 months and then analyzed using scanning electron microscopy, x-ray energy dispersive analysis, and small angle x-ray scattering. Results showed that some leakage of solution into the lead had occurred and changes were present on both the metal and the polyurethane surfaces.

  5. Primary arm spacing in chill block melt spun Ni-Mo alloys

    SciTech Connect (OSTI)

    Tewari, S.N.; Glasgow, T.K.

    1986-01-01

    Chill block melt spun ribbons of Ni-Mo binary alloys containing 8.0 to 41.8 wt % Mo have been prepared under carefully controlled processing conditions. The growth velocity has been determined as a function of distance from the quench surface from the observed ribbon thickness dependence on the melt puddle residence time. Primary arm spacings measured at the midribbon thickness locations show a dependence on growth velocity and alloy composition which is expected from dendritic growth models for binary alloys directionally solidified in a positive temperature gradient.

  6. SF6432-NI Fixed Price Contracts with the Newly Independent States of the Former Soviet Union

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II) byMultidayAlumni > The2/01/12 Page 1 of 24Department2/01/12 PageNI

  7. Fsica da UFRGS conquista Prmio L'Oral-Unesco O Brasil um dos vencedores do 15o Prmio L'Oral-Unesco

    E-Print Network [OSTI]

    Barbosa, Marcia C. B.

    "descobrir uma das peculiaridades da água que podem levar a um melhor entendimento de como os terremotos

  8. Shape-Memory Transformations of NiTi: Minimum-Energy Pathways between Austenite, Martensites, and Kinetically Limited Intermediate States

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zarkevich, N. A.; Johnson, D. D.

    2014-12-24

    NiTi is the most used shape-memory alloy, nonetheless, a lack of understanding remains regarding the associated structures and transitions, including their barriers. Using a generalized solid-state nudge elastic band (GSSNEB) method implemented via density-functional theory, we detail the structural transformations in NiTi relevant to shape memory: those between body-centered orthorhombic (BCO) groundstate and a newly identified stable austenite (“glassy” B2-like) structure, including energy barriers (hysteresis) and intermediate structures (observed as a kinetically limited R-phase), and between martensite variants (BCO orientations). All results are in good agreement with available experiment. We contrast the austenite results to those from the often-assumed, butmore »unstable B2. These high- and low-temperature structures and structural transformations provide much needed atomic-scale detail for transitions responsible for NiTi shape-memory effects.« less

  9. Calculations of structural, elastic, electronic, magnetic and phonon properties of FeNiMnAl by the first principles

    SciTech Connect (OSTI)

    U?ur, ?ule; ?yigör, Ahmet

    2014-10-06

    The electronic, elastic and dynamical properties of the quaternary alloy FeNiMnAl have been investigated using a pseudopotential plane wave method within the generalized gradient approximation (GGA). We determined the lattice parameters and the bulk modulus B. In addition, the elastic properties such as elastic constans (C{sub 11}, C{sub 12} and C{sub 44}), the shear modulus G, the young modulus E, the poisson's ratio ? and the B/G ratio are also given. The FeNiMnAl Heusler alloy exhibit a ferromagnetic half-metallic behavior with the total magnetic moment of 4.02 ?{sub B}. The phonon dispersion of FeNiMnAl has been performed using the density functional theory and the direct method with 2×2×2 supercell.

  10. Quantum valley Hall states and topological transitions in Pt(Ni, Pd)-decorated silicene: A first-principles study

    SciTech Connect (OSTI)

    Zhao, Bao; Zhang, Jiayong; Wang, Yicheng; Yang, Zhongqin

    2014-12-28

    The electronic states and topological behaviors of Pt(Ni, Pd)-decorated silicene are investigated by using an ab-initio method. All the three kinds of the adatoms prefer hollow sites of the silicene, guaranteeing the Dirac cones unbroken. The Pt(Ni, Pd)-decorated silicene systems all present quantum valley Hall (QVH) states with the gap opened exactly at the Fermi level. The gaps of the QVH states can be increased substantially by applying a positive electric field. Very fascinating phase transitions from QVH to quantum spin Hall (QSH) and then to QVH again are achieved in the Pt/Ni-decorated silicene when a negative electric field is applied. The QSH state in the Pd case with a negative electric field is, however, quenched because of relatively larger Rashba spin-orbit coupling (SOC) than the intrinsic SOC in the system. Our findings may be useful for the applications of silicene-based devices in valleytronics and spintronics.

  11. Interface control of ferroelectricity in LaNiO{sub 3}-BaTiO{sub 3} superlattices

    SciTech Connect (OSTI)

    Wu, Yin-Zhong, E-mail: yzwu@cslg.edu.cn [Jiangsu Laboratory of Advanced Functional Materials and Physics Department, Changshu Institute of Technology, Changshu 215500 (China); School of Mathematics and Physics, Suzhou University of Science and Technology, Suzhou 215009 (China); Lu, Hai-Shuang; Cai, Tian-Yi; Ju, Sheng, E-mail: jusheng@suda.edu.cn [Department of Physics and Jiangsu Key Laboratory of Thin Films, Soochow University, Suzhou 215006 (China)

    2014-08-15

    LaNiO{sub 3}-BaTiO{sub 3} superlattices with different types of interfaces are studied from first-principles density-functional theory. It is revealed that the ferroelectricity in the superlattice with (NiO{sub 2}){sup ?}/(BaO){sup 0} interfaces is enhanced from that of the superlattice with (LaO){sup +}/(TiO{sub 2}){sup 0} interfaces. The origin lies at the polar discontinuity at the interface, which makes the holes localized within the (NiO{sub 2}){sup ?}/(BaO){sup 0} interface, but drives a penetration of electrons into BaTiO{sub 3} component near (LaO){sup +}/(TiO{sub 2}){sup 0} interface. Our calculations demonstrate an effective avenue to the robust ferroelectricity in BaTiO{sub 3} ultrathin films.

  12. Effect of electronic structures on catalytic properties of CuNi alloy and Pd in MeOH-related reactions

    SciTech Connect (OSTI)

    Tsai, An-Pang [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); National Institute for Materials Science, Tsukuba 305-0047 (Japan); Kimura, Tomofumi; Suzuki, Yukinori; Kameoka, Satoshi [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Shimoda, Masahiko [National Institute for Materials Science, Tsukuba 305-0047 (Japan); Ishii, Yasushi [Department of Physics, Chuo University, Kasuga, Tokyo 112-8551 (Japan)

    2013-04-14

    We investigated the catalytic properties of a CuNi solid solution and Pd for methanol-related reactions and associated valence electronic structures. Calculations and X-ray photoelectron spectroscopy measurements revealed that the CuNi alloy has a similar valence electronic structure to Pd and hence they exhibited similar CO selectivities in steam reforming of methanol and decomposition of methanol. Samples prepared by various processes were found to have similar CO selectivities. We conjecture that alloying of Cu and Ni dramatically alters the valence electronic structures, making it similar to that of Pd so that the alloy exhibits similar catalytic properties to Pd. First-principles slab calculations of surface electronic structures support this conjecture.

  13. High-resolution transmission electron microscopy study of carbon deposited on the NiO/MgO solid solution catalysts

    SciTech Connect (OSTI)

    Hu, Y.H.; Ruckenstein, E.

    1999-05-15

    The carbon deposition due to the CH{sub 4} decomposition at 790 C over NiO/MgO catalysts was investigated by high-resolution transmission electron microscopy. While no deposits could be detected over the catalysts with a NiO content smaller than 9.1 wt%, they were detected over the catalysts with NiO contents of 23 and 50 wt%. The carbon deposits are composed of platelets located at distances of about 0.34 nm, corresponding to the graphitic carbon. Various structures of the deposited carbon were observed: (a) carbon consisting of platelets parallel to the surface of the particle, which covers a catalyst particle, (b) nanotubes composed of platelets parallel to their axis, and (c) carbon vortexes consisting of platelets parallel to their axis.

  14. Influence of fabrication technique and matrix alloying on the interfacial shear strength of sapphire-NiAl composites

    SciTech Connect (OSTI)

    Asthana, R.; Bowman, R.R.; Tewari, S.N.

    1994-12-31

    The influence of fabrication technique and alloying on the fiber matrix interfacial shear strength, measured using a fiber push-out technique, has been examined in sapphire fiber-reinforced NiAl matrix composites. The composites were fabricated using the powder-cloth (P-C) process, a casting process, and the zone directional solidification (DS) process. The NiAl matrix was alloyed with Cr, W or Yb. The results showed that, in general, cast and DS composites had higher interfacial shear strengths compared to the P-C composites containing binders. Neither matrix alloying nor casting and DS impaired the interface strength. The study highlights the potential of the DS process in designing dual-phase ductile microstructures in sapphire-reinforced NiAl alloys for improved toughness and strength.

  15. The Role of FeS in Initial Activation and Performance Degradation of Na-NiCl2 Batteries

    SciTech Connect (OSTI)

    Li, Guosheng; Lu, Xiaochuan; Kim, Jin Yong; Engelhard, Mark H.; Lemmon, John P.; Sprenkle, Vincent L.

    2014-12-25

    The role of iron sulfide (FeS) in initial cell activation and degradation in the Na-NiCl2 battery was investigated in this work. The research focused on identifying the effects of the FeS level on the electrochemical performance and morphological changes in the cathode. The x-ray photoelectron spectroscopy study along with battery tests revealed that FeS plays a critical role in initial battery activation by removing passivation layers on Ni particles. It was also found that the optimum level of FeS in the cathode resulted in minimum Ni particle growth and improved battery cycling performance. The results of electrochemical characterization indicated that sulfur species generated in situ during initial charging, such as polysulfide and sulfur, are responsible for removing the passivation layer. Consequently, the cells containing elemental sulfur in the cathode exhibited similar electrochemical behavior during initial charging compared to that of the cells containing FeS.

  16. 1.0 Espa,cos de Banach de se,c"oes de um fibrado vetorial. Definiremos nesta se,c"ao v'arios espa,cos vetoriais de se,c"oes de um fibr*

    E-Print Network [OSTI]

    Tausk, Daniel Victor

    1.0 Espa,cos de Banach de se,c"oes de um fibrado vetorial. Definiremos nesta se,c"ao v'arios espa,cos vetoriais de se,c"oes de um fibr* *ado vetorial sobre uma variedade compacta (possivelmente com bordo). Definiremos normas nestes esp* *a,cos mediante as quais eles se tornar"ao espa,cos de

  17. 48 SBA Controle & Automao Vol. 10 no. 01 / Jan., Fev., Mar, Abril de 1999 OTIMIZAO DE UM SISTEMA DE GERAO DE ENERGIA ELICA

    E-Print Network [OSTI]

    Simões, Marcelo Godoy

    SISTEMA DE GERAÇÃO DE ENERGIA EÓLICA ATRAVÉS DE CONTROLE FUZZY M. Godoy Simões, N.N. Franceschetti, Bimal lógica e controle fuzzy visando melhorias no desempenho de um sistema de geração de energia eólica, em turbina eólica de eixo vertical. Há um gerador de indução que alimenta um conversor PWM duplo, com

  18. Castability of Traditionally Wrought Ni-Based Superalloys for USC Steam Turbines

    SciTech Connect (OSTI)

    Jablonski, P D; Cowen, C J; Hawk, J A; Evens, N; Maziasz, P

    2011-02-27

    The high temperature components within conventional coal fired power plants are manufactured from ferritic/martensitic steels. In order to reduce greenhouse gas emissions the efficiency of pulverized coal steam power plants must be increased. The proposed steam temperature in the Advanced Ultra Supercritical (A-USC) power plant is high enough (760°C) that ferritic/martensitic steels will not work due to temperature limitations of this class of materials; thus Ni-based superalloys are being considered. The full size castings are quite substantial: ~4in thick, several feet in diameter and weigh 5-10,000lb each half. Experimental castings were quite a bit smaller, but section size was retained and cooling rate controlled in order to produce relevant microstructures. A multi-step homogenization heat treatment was developed in order to better deploy the alloy constituents. The castability of two traditionally wrought Ni-based superalloys to which minor alloy adjustments have been made in order to improve foundry performance is further explored.

  19. Direct production of nanostructured copper-nickel (Cu-Ni) alloy particles

    SciTech Connect (OSTI)

    Apaydin, Ramazan Oguzhan; Ebin, Burcak; Gurmen, Sebahattin

    2013-12-16

    Copper-Nickel (CuNi) nanostructured alloy particles were produced by Ultrasonic Spray Pyrolysis and Hydrogen Reduction Method (USP-HR) from high purity copper and nickel nitrate aqueous solutions. The effect of the precursor solution in the range of 0.1 and 0.5 mol/L on the morphology and crystallite size of CuNi nanoparticles were investigated under 2 h running time, 700 °C operating temperature and 0.5 L/min H{sub 2} flow rate. Particle size, morphology, composition and crystallite structure were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-Ray Diffraction (XRD). Particle characterization studies show that nanostructured alloy particles have cubic crystal structure and they are in submicron size range with spherical morphology. The crystallite sizes of the particles calculated with Scherrer formula are 40 and 34 nm and average particles sizes observed from the SEM images are 300 and 510 nm for each experiment respectively.

  20. Exponentially decaying magnetic coupling in sputtered thin film FeNi/Cu/FeCo trilayers

    SciTech Connect (OSTI)

    Wei, Yajun Akansel, Serkan; Thersleff, Thomas; Brucas, Rimantas; Lansaker, Pia; Leifer, Klaus; Svedlindh, Peter; Harward, Ian; Celinski, Zbigniew; Ranjbar, Mojtaba; Dumas, Randy K.; Jana, Somnath; Pogoryelov, Yevgen; Karis, Olof; Åkerman, Johan

    2015-01-26

    Magnetic coupling in trilayer films of FeNi/Cu/FeCo deposited on Si/SiO{sub 2} substrates have been studied. While the thicknesses of the FeNi and FeCo layers were kept constant at 100?Å, the thickness of the Cu spacer was varied from 5 to 50?Å. Both hysteresis loop and ferromagnetic resonance results indicate that all films are ferromagnetically coupled. Micromagnetic simulations well reproduce the ferromagnetic resonance mode positions measured by experiments, enabling the extraction of the coupling constants. Films with a thin Cu spacer are found to be strongly coupled, with an effective coupling constant of 3?erg/cm{sup 2} for the sample with a 5?Å Cu spacer. The strong coupling strength is qualitatively understood within the framework of a combined effect of Ruderman-Kittel-Kasuya-Yosida and pinhole coupling, which is evidenced by transmission electron microscopy analysis. The magnetic coupling constant surprisingly decreases exponentially with increasing Cu spacer thickness, without showing an oscillatory thickness dependence. This is partially connected to the substantial interfacial roughness that washes away the oscillation. The results have implications on the design of multilayers for spintronic applications.

  1. Magnetocaloric properties and critical behavior of high relative cooling power FeNiB nanoparticles

    SciTech Connect (OSTI)

    Chaudhary, V. [Interdisciplinary Graduate School, Nanyang Technological University, Singapore 639798 (Singapore); Energy Research Institute @NTU, Nanyang Technological University, Singapore 637553 (Singapore); School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Maheswar Repaka, D. V.; Chaturvedi, A.; Ramanujan, R. V., E-mail: ramanujan@ntu.edu.sg [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Sridhar, I. [School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2014-10-28

    Low cost magnetocaloric nanomaterials have attracted considerable attention for energy efficient applications. We report a very high relative cooling power (RCP) in a study of the magnetocaloric effect in quenched FeNiB nanoparticles. RCP increases from 89.8 to 640?J kg{sup ?1} for a field change of 1 and 5?T, respectively, these values are the largest for rare earth free iron based magnetocaloric nanomaterials. To investigate the magnetocaloric behavior around the Curie temperature (T{sub C}), the critical behavior of these quenched nanoparticles was studied. Detailed analysis of the magnetic phase transition using the modified Arrott plot, Kouvel-Fisher method, and critical isotherm plots yields critical exponents of ??=?0.364, ??=?1.319, ??=?4.623, and ??=??0.055, which are close to the theoretical exponents obtained from the 3D-Heisenberg model. Our results indicate that these FeNiB nanoparticles are potential candidates for magnetocaloric fluid based heat pumps and low grade waste heat recovery.

  2. Sessile dislocations by reactions in NiAl severely deformed at room temperature

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Geist, D.; Gammer, C.; Rentenberger, C.; Karnthaler, H. P.

    2015-02-05

    B2 ordered NiAl is known for its poor room temperature (RT) ductility; failure occurs in a brittle like manner even in ductile single crystals deforming by single slip. In the present study NiAl was severely deformed at RT using the method of high pressure torsion (HPT) enabling the hitherto impossible investigation of multiple slip deformation. Methods of transmission electron microscopy were used to analyze the dislocations formed by the plastic deformation showing that as expected dislocations with Burgers vector a(100) carry the plasticity during HPT deformation at RT. In addition, we observe that they often form a(110) dislocations by dislocationmore »reactions; the a(110) dislocations are considered to be sessile based on calculations found in the literature. It is therefore concluded that the frequently encountered 3D dislocation networks containing sessile a(110) dislocations are pinned and lead to deformation-induced embrittlement. In spite of the severe deformation, the chemical order remains unchanged.« less

  3. In situ transmission electron microscopy investigation of the interfacial reaction between Ni and Al during rapid heating in a nanocalorimeter

    SciTech Connect (OSTI)

    Grapes, Michael D., E-mail: mgrapes1@jhu.edu, E-mail: david.lavan@nist.gov, E-mail: weihs@jhu.edu [Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Material Measurement Laboratory, Materials Measurement Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); LaGrange, Thomas; Reed, Bryan W.; Campbell, Geoffrey H. [Lawrence Livermore National Laboratory, Materials Science and Technology Division, Livermore, California 94550 (United States); Woll, Karsten [Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Institute of Applied Materials, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen (Germany); LaVan, David A., E-mail: mgrapes1@jhu.edu, E-mail: david.lavan@nist.gov, E-mail: weihs@jhu.edu [Material Measurement Laboratory, Materials Measurement Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Weihs, Timothy P., E-mail: mgrapes1@jhu.edu, E-mail: david.lavan@nist.gov, E-mail: weihs@jhu.edu [Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States)

    2014-11-01

    The Al/Ni formation reaction is highly exothermic and of both scientific and technological significance. In this report, we study the evolution of intermetallic phases in this reaction at a heating rate of 830 K/s. 100-nm-thick Al/Ni bilayers were deposited onto nanocalorimeter sensors that enable the measurement of temperature and heat flow during rapid heating. Time-resolved transmission electron diffraction patterns captured simultaneously with thermal measurements allow us to identify the intermetallic phases present and reconstruct the phase transformation sequence as a function of time and temperature. The results show a mostly unaltered phase transformation sequence compared to lower heating rates.

  4. Duplex precipitates and their effects on the room-temperature fracture behaviour of a NiAl-strengthened ferritic alloy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sun, Zhiqian; Song, Gian; Ilavsky, Jan; Liaw, Peter K.

    2015-03-23

    Duplex precipitates are presented in a NiAl-strengthened ferritic alloy. They were characterized by the ultra-small angle X-ray scattering and transmission electron microscope. Fine cooling precipitates with the size of several to tens of nanometres harden the matrix considerably at room temperature. Cracks are likely to initiate from precipitates, and coalesce and propagate quickly through the matrix due to the excessive hardening effect of cooling precipitates, which lead to the premature fracture of NiAl-strengthened ferritic alloys.

  5. Madžarski kalk hištvo in sorodno v stari knjižni prekmurš?ini

    E-Print Network [OSTI]

    Dudá s, El?d

    2011-01-01

    uporabiti pri raziskavi madžarsko-slovenskih stikov, moramo poznati zgodovinske okoliš?ine, ki so igrale pri teh stikih pomembno vlogo. Prekmursko obmo?je je bilo vklju?eno v madžarski upravni sistem leta 1077 (Just 2009: 18) in je ostalo njegov del do... hižni zakon is a hybrid. Zakon is Slo- vene proper, whereas hižni is a calqued element from Hungarian. Among the calques discussed. Hištvo and hižnik are attested from the beginnings of Prekmurje Slovene literature. Hižna tivarišica is perhaps a hapax...

  6. Structural characterization of metastable hcp-Ni thin films epitaxially grown on Au(100) single-crystal underlayers

    SciTech Connect (OSTI)

    Ohtake, Mitsuru; Tanaka, Takahiro; Futamoto, Masaaki; Kirino, Fumiyoshi

    2010-05-15

    Ni(1120) epitaxial thin films with hcp structure were prepared on Au(100) single-crystal underlayers at 100 deg. C by ultra high vacuum molecular beam epitaxy. The detailed film structure is studied by in situ reflection high energy electron diffraction, x-ray diffraction, and transmission electron microscopy. The hcp-Ni film consists of two types of variants whose c-axes are rotated around the film normal by 90 deg. each other. An atomically sharp boundary is recognized between the film and the underlayer, where misfit dislocations are introduced. Presence of such dislocations seems to relieve the strain caused by the lattice mismatch between the film and the underlayer.

  7. Introduction: Bencubbin-like meteorites (CB) are metal-rich chondritic breccias containing about 60 vol% metallic (Fe,Ni) [1]. Unlike the CBa (Becubbin, Weatherford,

    E-Print Network [OSTI]

    vol% metallic (Fe,Ni) [1]. Unlike the CBa (Becubbin, Weatherford, Gujba) subgroup, the CBb (HH 237 al. [4] found that the Ir/Fe, Pd/Fe and Ni/Fe ratios in unzoned metal grains in the CBa chondrites that the components of CBa and CBb chondrites formed in a giant impact: SO chondrules and unzoned metal in Gujba

  8. Maxim > App Notes > BATTERY MANAGEMENT INTERFACE CIRCUITS Keywords: USB, USB Charger, Li+ USB charger, Lithium Ion USB charger, NiMH USB charger, USB battery

    E-Print Network [OSTI]

    Allen, Jont

    charger, Lithium Ion USB charger, NiMH USB charger, USB battery charger, charging batteries from USB, and cabling. An overview of nickel metal hydride (NiMH) and lithium battery technologies, charging methodsMaxim > App Notes > BATTERY MANAGEMENT INTERFACE CIRCUITS Keywords: USB, USB Charger, Li+ USB

  9. Crystal structure and dielectric properties of complex perovskite (Sr, Ba, Ca)(Ni0.5W0.5)O3

    E-Print Network [OSTI]

    Messing, Gary L.

    Crystal structure and dielectric properties of complex perovskite (Sr, Ba, Ca)(Ni0.5W0.5)O3 Takashi + was made for the complex perovskite Sr(Ni0.5W0.5)O3 to correlate with the structure evolution temperatures were studied using high temperature X-ray powder diffractometry. A single phase of the perovskite

  10. Ni SPECIATION IN A HUMIC ACID-KAOLINITE SYSTEM Maarten Nachtegaal,l Elham A. Ghabbour,2 Geoffrey Davies2and Donald L. Sparks}

    E-Print Network [OSTI]

    Sparks, Donald L.

    Ni SPECIATION IN A HUMIC ACID-KAOLINITE SYSTEM Maarten Nachtegaal,l Elham A. Ghabbour,2 Geoffrey and desorption experiments of Ni to a kaolinite-humic acid complex (containing both 1 and 5 wt% HA). Selected structure spectroscopy (XANES) studies will be used to describe interactions of humic acids with kaolinite

  11. Electroless preparation and characterization of Ni-B nanoparticles supported on multi-walled carbon nanotubes and their catalytic activity towards hydrogenation of styrene

    SciTech Connect (OSTI)

    Liu, Zheng; Li, Zhilin; Institute of Carbon Fibers and Composites, Beijing University of Chemical Technology, Beijing 100029 ; Wang, Feng; Institute of Carbon Fibers and Composites, Beijing University of Chemical Technology, Beijing 100029 ; Liu, Jingjun; Ji, Jing; Institute of Carbon Fibers and Composites, Beijing University of Chemical Technology, Beijing 100029 ; Park, Ki Chul; Endo, Morinobu

    2012-02-15

    Graphical abstract: The MWCNT/Ni-B catalyst has been successfully prepared by an electroless deposition process. The Ni-B nanoparticles on the supporter are amorphous and are well-distributed. The catalytic conversion towards hydrogenation of styrene shows excellent catalytic activity of the obtained materials. Highlights: Black-Right-Pointing-Pointer A two-step treatment of MWCNTs enabled the homogeneous growth of Ni-B nanoparticles. Black-Right-Pointing-Pointer Ni-B nanoparticles were amorphous with an average size of 60 nm. Black-Right-Pointing-Pointer There were electron transfer between Ni and B. Black-Right-Pointing-Pointer The catalyst had excellent catalytic activity towards hydrogenation of styrene. -- Abstract: Nickel-boron (Ni-B) nanoparticles supported on multi-walled carbon nanotubes (MWCNTs) were successfully synthesized through an electroless deposition process using the plating bath with sodium borohydride as a reducing agent. The structural and morphological analyses using field-emission scanning electron microscopy, X-ray diffractometry and high-resolution transmission electron microscopy have shown that the Ni-B nanoparticles deposited on the sidewalls of MWCNTs are fine spheres comprised of amorphous structure with the morphologically unique fine-structure like flowers, and homogenously dispersed with a narrow particle size distribution centered at around 60 nm diameter. The catalytic activity of MWCNT/Ni-B nanoparticles was evaluated with respect to hydrogenation of styrene. The hydrogenation catalyzed by MWCNT-supported Ni-B nanoparticles has been found to make styrene selectively converted into ethylbenzene. The highest conversion reaches 99.8% under proper reaction conditions, which demonstrates the high catalytic activity of MWCNT/Ni-B nanoparticles.

  12. Modification of carbon nanotubes by CuO-doped NiO nanocomposite for use as an anode material for lithium-ion batteries

    SciTech Connect (OSTI)

    Mustansar Abbas, Syed; Tajammul Hussain, Syed; Ali, Saqib; Ahmad, Nisar; Ali, Nisar; Abbas, Saghir; Ali, Zulfiqar

    2013-06-15

    CuO-doped NiO (CuNiO) with porous hexagonal morphology is fabricated via a modified in-situ co-precipitation method and its nanocomposite is prepared with carbon nanotubes (CNTs). The electrochemical properties of CuNiO/CNT nanocomposite are investigated by cyclic voltammetry (CV), galvanostatic charge–discharge tests and electrochemical impedance spectroscopy (EIS). Since Cu can both act as conductor and a catalyst, the CuNiO/CNT nanocomposite exhibits higher initial coulombic efficiency (82.7% of the 2nd cycle) and better capacity retention (78.6% on 50th cycle) than bare CuNiO (78.9% of the 2nd cycle), CuO/CNT (76.8% of the 2nd cycle) and NiO/CNT (77.7% of the 2nd cycle) at the current density of 100 mA /g. This high capacity and good cycling ability is attributed to the partial substitution of Cu{sup +2} for Ni{sup +2}, resulting in an increase of holes concentration, and therefore improved p-type conductivity along with an intimate interaction with CNTs providing large surface area, excellent conduction, mechanical strength and chemical stability. - Graphical abstract: The porous CuNiO/CNT nanocomposite synthesized via a modified co-precipitation method in combination with subsequent calcination was applied in the negative electrode materials for lithium-ion batteries and exhibited high electrochemical performance. - Highlights: • CuO doped NiO/CNTs nano composite is achieved via a simple co-precipitation method. • Monodispersity, shape and sizes of sample particles is specifically controlled. • Good quality adhesion between CNTs and CuNiO is visible from TEM image. • High electrochemical performance is achieved. • Discharge capacity of 686 mA h/g after 50 cycles with coulombic efficiency (82.5%)

  13. Influence of topography and Co domain walls on the magnetization reversal of the FeNi layer in FeNi/Al2O3/Co magnetic tunnel junctions

    E-Print Network [OSTI]

    Kuch, Wolfgang

    Influence of topography and Co domain walls on the magnetization reversal of the FeNi layer in Fe situated on and situated be- tween steps is large. To test the influence of the topography microscopic view of the influence of the substrate-induced layer topography on the magnetization reversal

  14. A flip-chip LIGA assembly technique via electroplating L.-W. Pan, L. Lin, J. Ni

    E-Print Network [OSTI]

    Lin, Liwei

    A flip-chip LIGA assembly technique via electroplating L.-W. Pan, L. Lin, J. Ni Abstract A novel ¯ip-chip assembly technique by means of electroplating at a low processing temperature has been to glass substrate. The bonding process is conducted by nickel electroplating at 50 °C with a current

  15. Chemical synthesis of monodisperse -FeNi magnetic nanoparticles with tunable Curie temperatures for self-regulated hyperthermia

    E-Print Network [OSTI]

    Laughlin, David E.

    magnetic field, MNPs in fer- rofluids dissipate heat via Néel and Brownian relaxation losses.3 Losses heating rate in ferrofluids is achievable for metallic nanoparticles having the largest satu- rationChemical synthesis of monodisperse -Fe­Ni magnetic nanoparticles with tunable Curie temperatures

  16. Measurement of spin diffusion length in sputtered Ni films using a special exchange-biased spin valve geometry

    E-Print Network [OSTI]

    Birge, Norman

    valve geometry Charles E. Moreaua Department of Physics, Albion College, Albion, Michigan 49224 Ion C exchange-biased spin valve geometry that inserts a Ni "spoiler" layer into a Py/Cu/Py spin valve. Fits In the context of ferromagnetic/nonmagnetic F/N multilayers or spin valves, the size of the giant

  17. Local domain structure of exchange-coupled NiFe/CoO nanowire probed by nonlocal spin valve measurement

    E-Print Network [OSTI]

    Otani, Yoshichika

    Local domain structure of exchange-coupled NiFe/CoO nanowire probed by nonlocal spin valve magnetization process in a 100-nm-wide Permalloy/CoO exchange-coupled wire by means of nonlocal spin valve valve structures.1 This phenomenon is described by the Meiklejohn­Bean model, which is based

  18. Perpendicular local magnetization under voltage control in Ni films on ferroelectric BaTiO3 substrates

    E-Print Network [OSTI]

    Ghidini, Massimo; Maccherozzi, Francesco; Moya, Xavier; Phillips, Lee C.; Yan, Wenjing; Soussi, Jordane; Métallier, Nicolas; Vickers, Mary E.; Steinke, Nina -J.; Mansell, Rhodri; Barnes, Crispin H. W.; Dhesi, Sarnjeet S.; Mathur, Neil D.

    2015-01-12

    University of Cambridge Cambridge, CB3 0HE , UK Dr. N.-J. Steinke ISIS, Harwell Science and Innovation Campus Didcot , Oxfordshire, OX11 0QX , UK DOI: 10.1002/adma.201404799 and destroy an OOP anisotropy in large contiguous areas of Ni fi lms...

  19. Features of the band structure and conduction mechanisms in the n-HfNiSn semiconductor heavily doped with Ru

    SciTech Connect (OSTI)

    Romaka, V. A.; Rogl, P.; Romaka, V. V.; Stadnyk, Yu. V.; Korzh, R. O.; Krayovskyy, V. Ya.; Horyn, A. M.

    2014-12-15

    The crystal and electronic structure and energy and kinetic properties of the n-HfNiSn semiconductor heavily doped with a Ru acceptor impurity are investigated in the temperature and Ru concentration ranges T = 80–400 K and N{sub A}{sup Ru} ? 9.5 × 10{sup 19}?5.7 × 10{sup 20} cm{sup ?3} (x = 0–0.03), respectively. The mechanism of structural-defect generation is established, which changes the band gap and degree of compensation of the semiconductor and consists in the simultaneous concentration reduction and elimination of donor structural defects by means of the displacement of ?1% of Ni atoms from the Hf (4a) positions, the generation of acceptor structural defects upon the substitution of Ru atoms for Ni atoms in the 4c positions, and the generation of donor defects in the form of vacancies in the Sn (4b) positions. The calculated electronic structure of HfNi{sub 1?x}Ru{sub x}Sn is consistent with the experiment. The results obtained are discussed within the Shklovsky-Efros model for a heavily doped and compensated semiconductor.

  20. Temperature dependence of carrier spin polarization determined from current-induced domain wall motion in a Co/Ni nanowire

    SciTech Connect (OSTI)

    Ueda, K.; Koyama, T.; Hiramatsu, R.; Kobayashi, K.; Ono, T.; Chiba, D.; Fukami, S.; Tanigawa, H.; Suzuki, T.; Ohshima, N.; Ishiwata, N.; Nakatani, Y.

    2012-05-14

    We have investigated the temperature dependence of the current-induced magnetic domain wall (DW) motion in a perpendicularly magnetized Co/Ni nanowire at various temperatures and with various applied currents. The carrier spin polarization was estimated from the measured domain wall velocity. We found that it decreased more with increasing temperature from 100 K to 530 K than the saturation magnetization did.

  1. Time Delays in Two-Photon Ionization Jing Su, Hongcheng Ni, Agnieszka Jaro-Becker, and Andreas Becker

    E-Print Network [OSTI]

    Becker, Andreas

    Time Delays in Two-Photon Ionization Jing Su, Hongcheng Ni, Agnieszka Jaro-Becker, and Andreas results of ab initio numerical simulations of time delays in two-photon ionization of the helium atom contributions, namely, a time delay acquired during the absorption of the two photons from the extreme

  2. The adsorption of molecular oxygen on Au/Ni(111) alloys and its oxidation of CO at 85 K

    E-Print Network [OSTI]

    Fischer, Jonathan David

    2010-01-01

    Molecular oxygen is observed to adsorb on 0.2 - 0.6 ML Au/Ni(111) surface alloys. Molecular oxygen adsorbates are characterized by their 0-0 stretching frequencies of 740 cm', 851 cm' and 962 cm', as measured by high ...

  3. Structure and magnetic properties of Ce?(Ni/Al/Ga)??—A new phase with the La?Al?? structure type

    SciTech Connect (OSTI)

    Janka, Oliver; Shang, Tian; Baumbach, Ryan E.; Bauer, Eric D.; Thompson, Joe D.; Kauzlarich, Susan M.

    2015-03-01

    Single crystals of Ce?(Ni/Al/Ga)?? were obtained from an Al flux reaction. Single crystals of the title compound crystallizing in the orthorhombic space group Immm (No. 71, Z = 2) with a = 436.38(14), b = 1004.5(3) and c = 1293.4(4) pm. This is a standardized unit cell of the previously published La?Al?? structure type. Wavelength dispersive microprobe provides the composition of Ce?.?????Ni?.?????Al?.?????Ga?.?????. Single crystal refinement provides the composition Ce?Ni?.??Al?.??Ga?.?? with substitution of the Ni and Ga on the Al1 and Al4 sites with the Al2 and Al3 solely occupied by Al. Magnetic susceptibility measurements reveal antiferromagnetic ordering with TN = 4.8 K and there is no evidence for a ferromagnetic ordering that has been reported for Ce?Al??. The effective magnetic moment was found to be ?eff = 1.9?B/Ce, which is lower than the expected value for trivalent Ce (2.54?B/Ce).

  4. Salicidation process using NiSi and its device application R. A. Johnson, P. M. Asbeck, and S. S. Lau

    E-Print Network [OSTI]

    Asbeck, Peter M.

    gate lines due to the retarded phase transition from the high resistivity C49 phase to the low temperature requirement for the C49 to C54 phase transition ( 800 °C) and the silicide agglomeration temperature window. In this article, the formation of nickel mono-silicide NiSi using rapid thermal annealing

  5. Mksbauer measurements of spin correlations in a-(Fe,Ni),,Zt$n D. Wiard&and D. H. Ryan

    E-Print Network [OSTI]

    Ryan, Dominic

    amorphous Fe,u-,Ni,Z@n system was investigated by Miissbauer spectroscopyfor x=1,3. The magnetic probe atom 57Feand the nonmagneticr19Snwere usedto monitor thelocal correlationof the spins.The additional ma $ netic correla- tions and excitations. Neutron depolarization and Lorentz microscopy4clearly show

  6. Electrodeposition, characterization and morphological investigations of NiFe/Cu multilayers prepared by pulsed galvanostatic, dual bath technique

    SciTech Connect (OSTI)

    Esmaili, S.; Bahrololoom, M.E.; Kavanagh, K.L.

    2011-02-15

    NiFe/Cu multilayers were grown sequentially by pulsed electrodeposition on copper (Cu) substrates. The layers were prepared in galvanostatic mode using a dual bath technique. The morphology, thickness, roughness and composition of the layers were studied using scanning electron microscopy, scanning transmission electron microscopy with energy dispersive X-ray spectroscopy, X-ray diffraction and atomic force microscopy. Analysis showed that the resulting multilayers were continuous layers with a root mean square roughness of 30 nm and a grain size of 20-60 nm. The Cu substrate and the electrodeposited Cu layer were preferentially (200) oriented while the NiFe layers were polycrystalline but with a preferred (200) texture. The thinnest multilayers produced were 20/40, NiFe/Cu, respectively. - Research Highlights: {yields} Thin MLs of Cu and Py can be ED utilizing a pulsed-galvanostatic, DBT. {yields} The resulting multilayers were continuous layers with an rms of 30 nm. {yields} The smallest average thickness achieved by DBT was 40 nm/20 nm for Cu/NiFe.

  7. The characterization of fluorocarbon films on NiTi alloy by magnetron sputtering *, F.T. Zi a

    E-Print Network [OSTI]

    Zheng, Yufeng

    reported. In our study, we used PTFE as the target, while the fluorocarbon films were prepared on Ni ultrasonically in acetone, methanol for 30 min, respec- tively, prior to being held on the cathode. A PTFE target between the substrates and the PTFE target was 85 mm and base pressure was 6.0 Â 10À4 Pa. The structure

  8. Electrical, optical and magnetic investigations on LiNiPO{sub 4} based olivines synthesized by solution combustion technique

    SciTech Connect (OSTI)

    Vijayan, Lakshmi [St. Aloysius College, Edathua, Alappuzha (District), Kerala 689573 (India); Cheruku, Rajesh [Department of Physics, School of Physical, Chemical and Applied Sciences, Pondicherry University, R.V. Nagar, Kalapet, Pondicherry 605 014 (India); Govindaraj, G., E-mail: ggraj_7@yahoo.com [Department of Physics, School of Physical, Chemical and Applied Sciences, Pondicherry University, R.V. Nagar, Kalapet, Pondicherry 605 014 (India)

    2014-02-01

    Highlights: • Solution combustion technique and preparation of nanocrystalline olivine materials. • Olivine type LiNiPO{sub 4} based nanocrystalline materials and characterization. • AC electrical studies on olivine type LiNi{sub 1?x}M{sub x}PO{sub 4}(M = Cu{sup 2+}/Mg{sup 2+})based materials. • Enhancement of ionic conductivity in the nanocrystalline phase of LiNiPO{sub 4} material. - Abstract: Citric acid assisted solution combustion technique is explored for synthesis of supervalent Cu{sup 2+}/Mg{sup 2+} ion doped LiNiPO{sub 4} system. XRD, FT-IR and microscopy studies confirmed the formation of a well crystallized material at low concentration of dopants. Ionic conductivity increases for lower concentrations of dopants due to the increased channel size for Li{sup +} diffusion. Owing to inherent anti-site defects, ionic conductivity decreases with increase of dopant concentration. Magnetic studies are explored for confirmation of antiferromagnetic nature of ions. Wagner polarization method is used to elucidate the negligible contribution of electrons to total conductivity.

  9. Cycle-Life Characterization of Automotive Lithium-Ion Batteries with LiNiO2 Cathode

    E-Print Network [OSTI]

    Cycle-Life Characterization of Automotive Lithium-Ion Batteries with LiNiO2 Cathode Yancheng Zhang of lithium- ion batteries for electric vehicles EVs and hybrid EVs HEVs . Substantial research has been- face, which is critical to the cycle life and calendar life of lithium- ion batteries.1,2 Unfortunately

  10. Ferromagnetism in Topochemically Prepared Layered Perovskite Li0.3Ni0.85La2Ti3O10

    E-Print Network [OSTI]

    Spinu, Leonard

    Ferromagnetism in Topochemically Prepared Layered Perovskite Li0.3Ni0.85La2Ti3O10 Doinita Neiner between the perovskite blocks of triple-layer Ruddlesden-Popper titanate Li2La2Ti3O10 by ion exchange

  11. Materials Science and Engineering A 394 (2005) 4352 NiAl bond coats made by a directed vapor deposition approach

    E-Print Network [OSTI]

    Wadley, Haydn

    2005-01-01

    Materials Science and Engineering A 394 (2005) 43­52 NiAl bond coats made by a directed vapor materials in thermal barrier coating systems applied to nickel base super alloy components. They are usually to nickel base su- peralloy components used in gas turbine engines [1]. In these systems, a metallic bond

  12. X-ray Absorption Measurements on Nickel Cathode of Sodium-beta Alumina batteries: Fe-Ni-CI Chemical Associations

    SciTech Connect (OSTI)

    Bowden, Mark E.; Alvine, Kyle J.; Fulton, John L.; Lemmon, John P.; Lu, Xiaochuan; Webb-Robertson, Bobbie-Jo M.; Heald, Steve M.; Balasubramanian, Mahalingam; Mortensen, Devon R.; Seidler, Gerald T.; Hess, Nancy J.

    2014-02-01

    Sections of Na-Al-NiCl2 cathodes from sodium-beta alumina ZEBRA batteries have been characterized with X-ray fluorescence mapping, and XANES measurements to probe the microstructure, elemental correlation, and chemical speciation after voltage cycling. Cycling was performed under identical load conditions at either 240 or 280 °C operating temperature and subsequently quenched in either the charged or discharged state. X-ray fluorescence mapping and XANES measurements were made adjacent to the current collector and ?"-Al2O3 solid electrolyte interfaces to detect possible gradients in chemical properties across the cathode. An FeS additive, introduced during battery synthesis, was found to be present as either Fe metal or an Fe(II) chloride in all cathode samples. X-ray fluorescence mapping reveals an operating temperature and charge-state dependent spatial correlation between Fe, Ni, and Cl concentration. XANES measurements indicate that both Ni and Fe are chemically reactive and shift between metallic and chloride phases in the charged and discharged states, respectively. However the percentage of chemically active Ni and Fe is significantly less in the cell operated at lower temperature. Additionally, the cathode appeared chemically homogeneous at the scale of our X-ray measurements.

  13. Development of Ni1-xCoxO as the cathode/interconnect contact for solid oxide fuel cells

    SciTech Connect (OSTI)

    Lu, Zigui; Xia, Guanguang; Templeton, Joshua D.; Li, Xiaohong S.; Nie, Zimin; Yang, Zhenguo; Stevenson, Jeffry W.

    2011-06-01

    A new type of material, Ni1-xCoxO, was developed for solid oxide fuel cell (SOFC) cathode/interconnect contact applications. The phase structure, coefficient of thermal expansion, sintering behavior, electrical property, and mechanical bonding strength of these materials were evaluated against the requirements of the SOFC cathode/interconnect contact. A dense cathode/interconnect contact layer was developed through reaction sintering from Ni and Co metal powders. An area specific resistance (ASR) as low as 5.5 mohm.cm2 was observed after 1000 h exposure in air at 800 °C for the LSM/Ni0.33Co0.67O/AISI441 assembly. Average mechanical strengths of 6.8 and 5.0 MPa were obtained for the cathode/contact/cathode and interconnect/contact/interconnect structures, respectively. The significantly low ASR was probably due to the dense structure and therefore improved electrical conductivity of the Ni0.33Co0.67O contact and the good bonding of the interfaces between the contact and the cathode, and between the contact and the interconnect.

  14. Aging effects in palladium and LaNi{sub 4.25}Al{sub 0.75} tritides

    SciTech Connect (OSTI)

    Nobile, A.; Wermer, J.R.; Walters, R.T.

    1991-12-31

    Palladium and LaNi{sub 5-x}Al{sub x} (x=0.30, 0.75, 0.85), which form reversible hydrides, are used for tritium processing and storage in the Savannah River Site (SRS) tritium facilities. As part of a program to develop technology based on the use of reversible metal hydrides for tritium processing and storage, the effects of aging on the thermodynamic behavior of palladium and LaNi{sub 4.25}Al{sub 0. 75} tritides are under investigation. During aging, the {sup 3}He tritium decay product remains in the tritide lattice and changes the thermodynamics of the tritium-metal tritide system. Aging effects in 755-day-aged palladium and 1423-day-aged LaNi{sub 4.25}Al{sub 0.75} tritides will be reported. Changes in the thermodynamics were determined by measuring tritium desorption isotherms on aging samples. In palladium, aging decreases the desorption isotherm plateau pressure and changes the {alpha}-phase portion of the isotherm. Aging-induced changes in desorption isotherms are more drastic in LaNi{sub 4.25}Al{sub 0.75}. Among the changes noted are: (1) decreased isotherm plateau pressure, (2) increased isotherm plateau slope, and (3) appearance of deep-trapped tritium, removable only by exchange with deuterium.

  15. Interdiffusion Behavior of Pt-Diffused gamma+gamma' Coatings on Ni-Based Superalloys

    SciTech Connect (OSTI)

    Zhang, Ying [Tennessee Technological University; Stacy, J P [Tennessee Technological University; Pint, Bruce A [ORNL; Haynes, James A [ORNL; Hazel, Brian T [GE Aviation; Nagaraj, Ben [GE Aviation

    2008-01-01

    Platinum-diffused {gamma} + {gamma}{prime} coatings ({approx} 20 at.% Al, {approx} 22 at.% Pt) were synthesized on Rene 142 and Rene N5 Ni-based superalloys by electroplating the substrates with {approx} 7 {micro}m of Pt, followed by an annealing treatment in vacuum at 1175 C. In order to study the compositional and microstructural evolution of these coatings at elevated temperatures, interdiffusion experiments were carried out on coated specimens in the temperature range of 900-1050 C for various durations. Composition profiles of the alloying elements in the {gamma} + {gamma}{prime} coatings before and after diffusion experiments were determined by electron probe microanalysis. Although the change of the Al content in the coatings was minimal under these interdiffusion conditions, the decrease of the Pt content and increase of the diffusion depth of Pt into the substrate alloys were significant. A preliminary diffusion model was used to estimate the Pt penetration depth after diffusion.

  16. Moessbauer and SANS Studies of Anti-Invar Fe-Ni-C Alloy under Magnetic Field

    SciTech Connect (OSTI)

    Nadutov, V. M.; Kosintsev, S. G.; Svystunov, Ye. O. [G.V. Kurdyumov Institute for Metal Physics of the N.A.S. of Ukraine, Kyiv (Ukraine); Garamus, V. M.; Willumeit, R.; Eckerlebe, H. [GKSS research center, Geeshtacht (Germany); Ericsson, T.; Annersten, H. [Uppsala University, Uppsala (Sweden)

    2010-07-13

    Anti-Invar effect in the f.c.c.-Fe-25.3%Ni-C alloy was revealed, i.e., enhanced thermal expansion coefficient (TEC)({approx}20x10{sup -6} K{sup -1}) which was accompanied by almost temperature-insensitive behavior in a temperature range of 122-525 K that was considerably expanded to the low temperature range due to alloying with carbon. The Moessbauer and small-angle neutron scattering (SANS) experiments with the varying temperature and in an external magnetic field of 1.5-5 T have revealed an existence of inhomogeneous magnetic order in anti-Invar alloy below and above the magnetic transition point. The anti-Invar behavior correlates with the thermally induced change in the magnetic order and interspin interaction.

  17. MINERALOGICAL MAGAZINE .VOLUME 62A Assessment of Ni sorption mechanisms on soil mineral surfaces

    E-Print Network [OSTI]

    Sparks, Donald L.

    a r t m e n t o f P l a n t a n d S o i l S c i e n c e s , U n i v e r s i t y o f D e l a w a r e , D . L . S p a r k s N e w a r k , D E 1 9 7 1 7 - 1 3 0 3 , U S A Many kinetic studies have shown was not Ni(0H)2 (s). The nucleation of the heterogeneous s o l i d a t t h e s u r f a c e i n t e r f a c e

  18. Seed influence on the ferromagnetic resonance response of Co/Ni multilayers

    SciTech Connect (OSTI)

    Sabino, Maria Patricia Rouelli, E-mail: maria-sabino@dsi.a-star.edu.sg; Tran, Michael; Hin Sim, Cheow; Ji Feng, Ying; Eason, Kwaku [Data Storage Institute, Agency for Science, Technology and Research, 5 Engineering Drive 1, Singapore 117608 (Singapore)

    2014-05-07

    The effect of Pd and Ru seed layers on the magnetic properties of [Co/Ni]{sub N} multilayers with varying number of bilayer repeats N is investigated using vector network analyzer ferromagnetic resonance. The effective anisotropy field H{sub Keff} is found to increase with N for Ru seed, but decreases for Pd until N?=?15. As N is increased beyond 15, H{sub Keff} decreases for both seeds. In contrast, the damping parameter ? decreases with N regardless of the seed, showing a 1/N dependence. Taking spin pumping into account, the intrinsic damping ?{sub 0} for both Pd and Ru seeds reduce to ?{sub 0} ? 0.01. These results demonstrate that there can be a strong influence of the seed/Co interface on anisotropy, especially for sufficiently low N, but not necessarily on ?{sub 0}.

  19. Isospin symmetry and proton decay: Identification of the 10{sup +} isomer in {sup 54}Ni

    SciTech Connect (OSTI)

    Rudolph, D.; Hellstroem, M.; Andersson, L.-L.; Fahlander, C.; Johansson, E. K. [Department of Physics, Lund University, S-22100 Lund (Sweden); Hoischen, R. [Department of Physics, Lund University, S-22100 Lund (Sweden); Gesellschaft fuer Schwerionenforschung mbH, D-64291 Darmstadt (Germany); Pietri, S.; Podolyak, Zs.; Regan, P. H.; Steer, S. J. [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Garnsworthy, A. B. [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520-8124 (United States); Becker, F.; Gerl, J.; Gorska, M.; Kojouharov, I.; Kurz, N.; Schaffner, H.; Wollersheim, H. J. [Gesellschaft fuer Schwerionenforschung mbH, D-64291 Darmstadt (Germany); Bednarczyk, P.; GrePbosz, J. [Gesellschaft fuer Schwerionenforschung mbH, D-64291 Darmstadt (Germany); Henryk Niewodniczanski Institute of Nuclear Physics (IFJ PAN), PL-31342 Krakow (Poland)] (and others)

    2008-08-15

    The {gamma} decays from an isomeric 10{sup +} state at 6457 keV in the nucleus {sub 28}{sup 54}Ni{sub 26} have been identified using the GSI fragment separator in conjunction with the RISING Ge-detector array. The state is interpreted as the isobaric analog of the 6527-keV 10{sup +} isomer in {sub 26}{sup 54}Fe{sub 28}. The results are discussed in terms of isospin-dependent shell-model calculations. Clear evidence is presented for a discrete l=5 proton decay branch into the first excited 9/2{sup -} state of the daughter {sup 53}Co. This decay is the first of its kind observed following projectile fragmentation reactions.

  20. Gii thiu v trng UMass Amherst l trng ni ting trong h thng i Hc Mas-

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    trng i hc vi 60% s sinh viên i hc ti các khu ký túc xá trong trng và thng thc các món n cng tin. Cng hc ca trng cng c ánh giá rt cao. Bng xp hng 5.000 chng trình tin s nm 2010 ca y Ban Nghiên Cu Quc Gia hc t thc. Tám ngành hc khác cng rt ni ting là: công ngh sinh hc ng vt, hóa k thut, hóa hc, công ngh

  1. Development of Ni-based Sulfur Resistant Catalyst for Diesel Reforming

    SciTech Connect (OSTI)

    Gunther Dieckmann

    2006-06-30

    In order for diesel fuel to be used in a solid oxide fuel cell auxiliary power unit, the diesel fuel must be reformed into hydrogen, carbon monoxide and carbon dioxide. One of the major problems facing catalytic reforming is that the level of sulfur found in low sulfur diesel can poison most catalysts. This report shows that a proprietary low cost Ni-based reforming catalyst can be used to reform a 7 and 50 ppm sulfur containing diesel fuel for over 500 hours of operation. Coking, which appears to be route of catalyst deactivation due to metal stripping, can be controlled by catalyst modifications, introduction of turbulence, and/or by application of an electromagnetic field with a frequency from {approx}50 kHz to 13.56 MHz with field strength greater than about 100 V/cm and more preferably greater about 500 V/cm.

  2. Strain controlled metal-insulator transition in epitaxial NdNiO{sub 3} thin films

    SciTech Connect (OSTI)

    Xiang, P.-H. Zhong, N.; Duan, C.-G.; Tang, X. D.; Hu, Z. G.; Yang, P. X.; Zhu, Z. Q.; Chu, J. H.

    2013-12-28

    We have fabricated epitaxial thin films of NdNiO{sub 3} (NNO) on various single crystal substrates. The transport properties of NNO films are very sensitive to substrate-controlled epitaxial strain. As the strain varies from tensile to compressive, the Mott metal-insulator transition of NNO films shifts to low temperatures. Under a larger compressive strain, the film on LaSrAlO{sub 4} substrate exhibits a practically metallic transport characteristic. We have found that the conductivities of NNO films at low temperatures follow Mott's variable range hopping mechanism rather than thermal activation model and the epitaxial strain has a strong effect on Mott's parameters of NNO films. These findings demonstrate that the electronic transport of NNO thin films can be tuned by the epitaxial strain for next-generation perovskite-based microelectronic devices.

  3. Energy levels and radiative rates for transitions in Cr-like Co IV and Ni V

    E-Print Network [OSTI]

    Aggarwal, K M; Karpuškien?, R; Keenan, F P; Kisielius, R; Stancalie, V

    2015-01-01

    We report calculations of energy levels and radiative rates ($A$-values) for transitions in Cr-like Co IV and Ni V. The quasi-relativistic Hartree-Fock (QRHF) code is adopted for calculating the data although GRASP (general-purpose relativistic atomic structure package) and flexible atomic code (FAC) have also been employed for comparison purposes. No radiative rates are available in the literature to compare with our results, but our calculated energies are in close agreement with those compiled by NIST for a majority of the levels. However, there are discrepancies for a few levels of up to 3\\%. The $A$-values are listed for all significantly contributing E1, E2 and M1 transitions, and the corresponding lifetimes reported, although unfortunately no previous theoretical or experimental results exist to compare with our data.

  4. NaNi sub 3 Mn sub 2 alloy as a tritium storage material

    SciTech Connect (OSTI)

    Ide, T.; Okuno, K.; Konishi, S.; Sakai, F.; Fukui, H.; Enoeda, M.; Naruse, Y.; Anderson, J.L.; Bartlit, J.R. (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan); Los Alamos National Lab., NM (USA))

    1989-01-01

    An all metal apparatus has been constructed and installed in the main cell of the Tritium System Assembly (TSTA) at Los Alamos National Laboratory, as a separate experiment, to handle about 2600 Ci of tritium for study of metal tritides of potential application for storing tritium in fusion fuel processing. The apparatus is similar to that used for protium/deuterium gas but some modifications were made to assure safe handling of tritium. The pressure-composition isotherms for the LaNi{sub 3}Mn{sub 2}-protium (H), deuterium (D) and tritium (T) system were measured to study isotopic effects in the temperature range of 60 {degree}C to 250 {degree}C, the pressure range below 120 kPa. 2 refs., 10 figs.

  5. Crystallization and phase transformations in amorphous NiTi thin films for microelectromechanical systems

    SciTech Connect (OSTI)

    Lee, Hoo-Jeong; Ramirez, Ainissa G. [Department of Mechanical Engineering, Yale University, New Haven, Connecticut 06520 (United States)

    2004-08-16

    Amorphous sputtered nickel-titanium thin films were deposited onto micromachined silicon-nitride membranes and subjected to heating and cooling conditions. Their associated microstructure was monitored directly and simultaneously with in situ transmission electron microscopy. These electron-transparent membranes constrained the NiTi films and rendered it possible for observation of the complete transformation cycle, which includes: the crystallization of the amorphous phase to austenite phase (cubic B2 structure) with heating; and the conversion of austenite (B2) to martensite (monoclinic B19{sup '} structure) with cooling. Electron micrographs show the nucleation and growth of grains occurs at a temperature of 470 deg. C and at a rate that indicates a polymorphic transformation. The onset of martensitic transformation occurs between 25 and 35 deg. C. Calorimetric measurements are consistent with the observed crystallization.

  6. A Climate Network Based Stability Index for El Ni\\~no Variability

    E-Print Network [OSTI]

    Feng, Qing Yi

    2015-01-01

    Most of the existing prediction methods gave a false alarm regarding the El Ni\\~no event in 2014. A crucial aspect is currently limiting the success of such predictions, i.e. the stability of the slowly varying Pacific climate. This property determines whether sea surface temperature perturbations will be amplified by coupled ocean-atmosphere feedbacks or not. The so-called Bjerknes stability index has been developed for this purpose, but its evaluation is severely constrained by data availability. Here we present a new promising background stability index based on complex network theory. This index efficiently monitors the changes in spatial correlations in the Pacific climate and can be evaluated by using only sea surface temperature data.

  7. Transition-metal and metalloid substitutions in L1(0)-ordered FeNi

    SciTech Connect (OSTI)

    Manchanda, P; Skomski, R; Bordeaux, N; Lewis, LH; Kashyap, A

    2014-05-07

    The effect of atomic substitutions on the magnetization, exchange, and magnetocrystalline anisotropy energy of L1(0)-ordered FeNi (tetrataenite) is computationally investigated. The compound naturally occurs in meteorites but has attracted renewed attention as a potential material for permanent magnets, and elemental additives will likely be necessary to facilitate the phase formation. Our density functional theory calculations use the Vienna ab-initio simulation package, applied to 4-atom unit cells of Fe2XNi and 32-atom supercells (X = Al, P, S, Ti, V, Cr, Mn, Fe, Co). While it is found that most additives deteriorate the magnetic properties, there are exceptions: excess substitutional Fe and Co additions improve the magnetization, whereas Cr, S, and interstitial B additions improve the magnetocrystalline anisotropy. (C) 2014 AIP Publishing LLC.

  8. Transition-metal and metalloid substitutions in L1{sub 0}-ordered FeNi

    SciTech Connect (OSTI)

    Manchanda, Priyanka; Skomski, Ralph; Bordeaux, N.; Lewis, L. H.; Kashyap, Arti

    2014-05-07

    The effect of atomic substitutions on the magnetization, exchange, and magnetocrystalline anisotropy energy of L1{sub 0}-ordered FeNi (tetrataenite) is computationally investigated. The compound naturally occurs in meteorites but has attracted renewed attention as a potential material for permanent magnets, and elemental additives will likely be necessary to facilitate the phase formation. Our density functional theory calculations use the Vienna ab-initio simulation package, applied to 4-atom unit cells of Fe{sub 2}XNi and 32-atom supercells (X?=?Al, P, S, Ti, V, Cr, Mn, Fe, Co). While it is found that most additives deteriorate the magnetic properties, there are exceptions: excess substitutional Fe and Co additions improve the magnetization, whereas Cr, S, and interstitial B additions improve the magnetocrystalline anisotropy.

  9. Electric and magnetic behaviors observed in NiO-based thin films under light-irradiation

    SciTech Connect (OSTI)

    Luo, Yi-Dong; Song, Kenan; Shun, Li; Gao, Junqi; Xu, Ben, E-mail: xuben@mail.tsinghua.edu.cn, E-mail: linyh@mail.tsinghua.edu.cn; Lin, Yuan-Hua, E-mail: xuben@mail.tsinghua.edu.cn, E-mail: linyh@mail.tsinghua.edu.cn; Nan, Ce-Wen; Liu, Wei [State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2014-09-07

    We report the room-temperature ferromagnetic properties that can be tuned by light irradiation in the Li and Mn co-doped NiO films (LMNO) grown by the spinning coating. The optical tunable magnetic behavior is enhanced by the increase of the Li doping concentration. First-principle calculations reveal that the Li doping plays key roles in the optical tuned magnetic behavior, which brings a 3d-like impurity state to enhance a significant hybridization between the Mn{sup 3+} 3d state and the impurity band, thus strengthening the ferromagnetic coupling effects. Additionally, it can tune the band gap of the LMNO films and produce more holes under the light irradiation, enhancing the optical tuned magnetic behavior.

  10. Factors affecting initial permeability of Co-substituted Ni-Zn-Cu ferrites

    SciTech Connect (OSTI)

    Byun, T.Y.; Byeon, S.C.; Hong, K.S.; Kim, C.K.

    1999-09-01

    Iron deficient compositions of (Ni{sub 0.2}Cu{sub 0.2}Zn{sub 0.6}){sub 1.02{minus}x}Co{sub x}Fe{sub 1.98}O{sub 4} (0 {le} x {le} 0.05) were prepared to investigate their initial permeability dependence on cobalt contents. Extrinsic factors such as grain size and sintered density change little in samples sintered at 900 C, so their effects on permeability can be neglected. Intrinsic factors such as saturation magnetization, magnetocrystalline anisotropy (K{sub 1}) and magnetoelastic anisotropy (K{sub {sigma}}) can not account for the variation of initial permeability with Co content. Measurement of thermoelectric power shows that the concentration of cation vacancies increases with Co content. Therefore, the local induced anisotropy increases by the ordering of Co ions cia increased cation vacancy concentration. This increase in induced anisotropy results in the decrease of initial permeability.

  11. Cu--Ni--Fe anode for use in aluminum producing electrolytic cell

    SciTech Connect (OSTI)

    Bergsma, S. Craig; Brown, Craig W.; Bradford, Donald R; Barnett, Robert J.; Mezner, Michael B.

    2006-07-18

    A method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte, the method comprising the steps of providing a molten salt electrolyte at a temperature of less than 900.degree. C. having alumina dissolved therein in an electrolytic cell having a liner for containing the electrolyte, the liner having a bottom and walls extending upwardly from said bottom. A plurality of non-consumable Cu--Ni--Fe anodes and cathodes are disposed in a vertical direction in the electrolyte, the cathodes having a plate configuration and the anodes having a flat configuration to compliment the cathodes. The anodes contain apertures therethrough to permit flow of electrolyte through the apertures to provide alumina-enriched electrolyte between the anodes and the cathodes. Electrical current is passed through the anodes and through the electrolyte to the cathodes, depositing aluminum at the cathodes and producing gas at the anodes.

  12. Self-assembled nano- to micron-size fibers from molten R11Ni4In9 intermetallics

    SciTech Connect (OSTI)

    Provino, Alessia; Manfrinetti, Pietro; Gschneidner, Karl A.; Dhar, Sudesh K.; Schlagel, Deborah L.; Lograsso, Thomas A.; Miller, Gordon J.; Thimmaiah, Srinivasa; Wang, Hui; Russell, Alan M.; Becker, Andrew; Mudryk, Yaroslav

    2014-07-01

    A study of the formation of Gd11M4In9 (M = Ni, Pd, Pt) and R11Ni4In9 (R = rare earth) compounds revealed a unique and peculiar property, which is to naturally crystallize in a bundle of self-assembled fibers when cooled from the melt. The fibers, which are nano- to millimeters in cross-section and approximate to 11-40 mm long, grow unidirectionally along a temperature gradient. These compounds adopt the orthorhombic Nd11Pd4In9 structure type (oC48-Cmmm). This structure is layered, with slabs of R atoms alternating with slabs of Ni/In atoms along a short c-axis (much shorter than either the a- or b-axis). The growth direction of the fibers is along the crystallographic c-axis, orthogonal to the a-b plane. Two strong and short In In bonds lie in the a-b plane, which are even shorter than in In metal. Integrated crystal orbital Hamilton population calculations show that the In In bonds create isolated "R8Ni4In9" rods growing along the c-axis, with the In In bonds being part of the rods. This appears to be an important factor explaining the microfibrous nature of these phases. Some physical properties have been measured on the Gd11Ni4In9 homolog. The compound orders ferrimagnetically at T-c approximate to 88 K, and at lower temperatures (46 and 10 K), two other magnetic anomalies were observed, probably due to spin reorientations. As expected from the bonding features, the mechanical, magnetic and electrical properties are strongly anisotropic. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  13. Characteristics of a new creep regime in polycrystalline NiAl

    SciTech Connect (OSTI)

    Raj, S.V.; Farmer, S.C. )

    1995-02-01

    Constant-load creep tests were conducted on fine-grained ([approximately]23 [mu]m) Ni-50.6 (at. pct) Al in the temperature range of 1,000 to 1,400 K. Power-law creep with a stress exponent, n [approx] 6.5, and an activation energy, Q[sub c] [approx] 290 kJ mol[sup [minus]1], was observed above 25 MPa, while a new mechanism with n [approx] 2 and Q[sub c] [approx] 100 kJ mol[sup [minus]1] dominates when [sigma] < 25 MPa, where [sigma] is the applied stress. A comparison of the creep behavior of fine- and course-grained NiAl established that the mechanism in the n [approx] 2 region was dependent on grain size, and the magnitude of the grain-size exponent was estimated to be about 2. Transmission electron microscopy (TEM) observations of the deformed specimens revealed a mixture of dislocation tangles, dipoles, loops, and subboundary networks in the power-law creep regime. The deformation microstructures were inhomogeneous in the n [approx] 2 creep regime, and many grains did not reveal any dislocation activity. However, bands of dislocation loops were observed in a few grains, where these loops appeared to have been emitted from the grain boundaries. The observed creep characteristics of the low-stress region suggest the dominance of an accommodated grain-boundary sliding (GBS) mechanism, although the experimental creep rates were lower than those predicted by theoretical models by over seven orders of magnitude. The low value of Q[sub c] in this region, which is approximately one-third that for lattice self-diffusion, is attributed to the possible existence of interconnected vacancy flow channels, or nanotubes'', at the grain boundaries.

  14. Mechanistic insights of ethanol steam reforming over Ni-CeOx(111): The importance of hydroxyl groups for suppressing coke formation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Zongyuan; Senanayake, Sanjaya D.; Duchon, Tomas; Wang, Huanru; Peterson, Erik W.; Zhou, Yinghui; Luo, Si; Zhou, Jing; Matolin, Vladimir; Stacchiola, Dario J.; et al

    2015-07-10

    We have studied the reaction of ethanol and water over Ni–CeO2-x(111) model surfaces to elucidate the mechanistic steps associated with the ethanol steam reforming (ESR) reaction. Our results provide insights about the importance of hydroxyl groups to the ESR reaction over Ni-based catalysts. Systematically, we have investigated the reaction of ethanol on Ni–CeO2-x(111) at varying Ce³? concentrations (CeO1.8–2.0) with absence/presence of water using a combination of soft X-ray photoelectron spectroscopy (sXPS) and temperature-programmed desorption (TPD). Consistent with previous reports, upon annealing, metallic Ni formed on reduced ceria while NiO was the main component on fully oxidized ceria. Ni? is themore »active phase leading to both the C–C and C–H cleavage of ethanol but is also responsible for carbon accumulation or coking. We have identified a Ni?C phase that formed prior to the formation of coke. At temperatures above 600K, the lattice oxygen from ceria and the hydroxyl groups from water interact cooperatively in the removal of coke, likely through a strong metal–support interaction between nickel and ceria that facilitates oxygen transfer.« less

  15. Mechanistic Insights of Ethanol Steam Reforming over Ni–CeO x (111): The Importance of Hydroxyl Groups for Suppressing Coke Formation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Zongyuan; Ducho?, Tomáš; Wang, Huanru; Peterson, Erik W.; Zhou, Yinghui; Luo, Si; Zhou, Jing; Matolín, Vladimir; Stacchiola, Dario J.; Rodriguez, José A.; et al

    2015-07-30

    We have studied the reaction of ethanol and water over Ni–CeO2-x(111) model surfaces to elucidate the mechanistic steps associated with the ethanol steam reforming (ESR) reaction. Our results provide insights about the importance of hydroxyl groups to the ESR reaction over Ni-based catalysts. Systematically, we have investigated the reaction of ethanol on Ni–CeO2-x(111) at varying Ce³? concentrations (CeO1.8–2.0) with absence/presence of water using a combination of soft X-ray photoelectron spectroscopy (sXPS) and temperature-programmed desorption (TPD). Consistent with previous reports, upon annealing, metallic Ni formed on reduced ceria while NiO was the main component on fully oxidized ceria. Ni? is themore »active phase leading to both the C–C and C–H cleavage of ethanol but is also responsible for carbon accumulation or coking. We have identified a Ni?C phase that formed prior to the formation of coke. At temperatures above 600K, the lattice oxygen from ceria and the hydroxyl groups from water interact cooperatively in the removal of coke, likely through a strong metal–support interaction between nickel and ceria that facilitates oxygen transfer.« less

  16. Synthesis of murdochite-type Ni{sub 6}MnO{sub 8} with variable specific surface areas and the application in methane oxidation

    SciTech Connect (OSTI)

    Taguchi, Hideki; Tahara, Shohei; Okumura, Mikoto; Hirota, Ken

    2014-07-01

    To synthesize a murdochite-type Ni{sub 6}MnO{sub 8} with variable specific surface areas, an oxalate precursor was calcined at 350–500 °C in flowing argon, and the calcined sample was heated to 600 °C in air. The lattice constant of the Ni{sub 6}MnO{sub 8} did not depend on the calcination temperature of the precursor, while the specific surface area decreased from 8.4 m{sup 2}/g to 2.6 m{sup 2}/g when increasing the calcination temperature of the precursor. The methane (CH{sub 4}) oxidation data indicated that the temperature corresponding to the 50% conversion (T{sub 50%}) of Ni{sub 6}MnO{sub 8} calcined at 350 °C or 400 °C was lower than that of all other Ni{sub 6}MnO{sub 8} specimens. However, the intrinsic conversion of Ni{sub 6}MnO{sub 8} calcined at 350 °C, which is defined as conversion per specific surface area, was half of that of all other Ni{sub 6}MnO{sub 8} specimens. The degree of crystallinity and catalytic performance of the Ni{sub 6}MnO{sub 8} calcined at 400 °C were high. - Graphical abstract: The conversion of CH{sub 4} into CO{sub 2} and H{sub 2}O on Ni{sub 6}MnO{sub 8}, which was heated at 600 °C in air after the calcination of the precursor at 350 °C, 400 °C, 450 °C, or 500 °C in flowing argon, was measured. Since the specific surface area was strongly affected by the calcination temperature of the precursor, intrinsic conversion (IC) was defined as conversion per the specific surface area. For comparison, the IC value on Ni{sub 6}MnO{sub 8} synthesized by the direct calcination of the precursor at 600 °C in air is plotted. - Highlights: • The oxalate precursor was calcined at 350–500 °C in flowing argon. • Murdochite-type Ni{sub 6}MnO{sub 8} was obtained by heating the calcined sample in air. • The specific surface area of Ni{sub 6}MnO{sub 8} varied with the calcination temperature. • The degree of crystallinity and catalysis of Ni{sub 6}MnO{sub 8} calcined at 400 °C were high.

  17. Pressure-Induced Structural Phase Transition in CeNi: X-ray and Neutron Scattering Studies and First-Principles Calculations

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Mirmelstein, A.; Podlesnyak, Andrey A.; dos Santos, Antonio M.; Ehlers, Georg; Kerbel, O.; Matvienko, V.; Sefat, A. S.; Saporov, B.; Halder, G. J.; Tobin, J. G.

    2015-08-03

    The pressure-induced structural phase transition in the intermediate-valence compound CeNi has been investigated by x-ray and neutron powder diffraction techniques. It is shown that the structure of the pressure-induced CeNi phase (phases) can be described in terms of the Pnma space group. Equations of state for CeNi on both sides of the phase transition are derived and an approximate P-T phase diagram is suggested for Pmore »the phase transition.« less

  18. Soil Moisture Initialization for Climate Prediction: Characterization of Model and Observation Errors Wenge Ni-Meister (1), Jeffrey Walker(3), and Paul R. Houser (2)

    E-Print Network [OSTI]

    Walker, Jeff

    and Observation Errors Wenge Ni-Meister (1), Jeffrey Walker(3), and Paul R. Houser (2) 1. Department of Geology of the land surface soil moisture states. Passive microwave remote sensing provides quantitative information

  19. Surface Chemistry and Non-Stoichiometry of Nd2NiO4+  Epitaxial Thin Films with Different Orientation and Strain

    E-Print Network [OSTI]

    Tsvetkov, Nikolai

    The influence of lattice strain on non-stoichiometry and surface chemical composition was investigated for epitaxial Nd2NiO4+ä (NNO) films during annealing in ultra high vacuum (below 10[superscript -8] mbar) and temperatures ...

  20. Ab-initio First Principle Modeling of Structural and Magnetic Phase Transformations in Co-Ni-Al Based Shape Memory Alloys 

    E-Print Network [OSTI]

    Thawabi, Hassan S

    2013-04-16

    . These magnetic properties are mainly attributed to the martensitic structural phase trans- formation these material experience in response to temperature variation. Co-Ni-Al based alloys are one of the most promising ferromagnetic shape memory alloy FSMA that has...

  1. IMPROVED Ni I log(gf) VALUES AND ABUNDANCE DETERMINATIONS IN THE PHOTOSPHERES OF THE SUN AND METAL-POOR STAR HD 84937

    SciTech Connect (OSTI)

    Wood, M. P.; Lawler, J. E.; Sneden, C.; Cowan, J. J. E-mail: jelawler@wisc.edu E-mail: cowan@nhn.ou.edu

    2014-04-01

    Atomic transition probability measurements for 371 Ni I lines in the UV through near-IR are reported. Branching fractions from data recorded using a Fourier transform spectrometer and a new echelle spectrograph are combined with published radiative lifetimes to determine these transition probabilities. Generally good agreement is found in comparisons to previously reported Ni I transition probability measurements. Use of the new echelle spectrograph, independent radiometric calibration methods, and independent data analysis routines enable a reduction of systematic errors and overall improvement in transition probability uncertainty over previous measurements. The new Ni I data are applied to high-resolution visible and UV spectra of the Sun and metal-poor star HD 84937 to derive new, more accurate Ni abundances. Lines covering a wide range of wavelength and excitation potential are used to search for non-LTE effects.

  2. Effect of Residence Time on Ni-Sorption Mechanisms on Clay and Oxide Minerals: An X-ray Absorption Fine Structure (XAFS) Study

    E-Print Network [OSTI]

    Sparks, Donald L.

    Effect of Residence Time on Ni-Sorption Mechanisms on Clay and Oxide Minerals: An X-ray Absorption minerals is typically fast initially, then the rates gradually diminish. In the literature the decline

  3. First-principle investigations of K{sub 2}NiF{sub 4}-type double perovskite oxides La{sub 4}B?B?O{sub 8} (B?B??=?Fe, Co, Ni)

    SciTech Connect (OSTI)

    Mao, Hejie; Wei, Yingfen; Gui, Hong; Li, Xin; Zhao, Zhenjie Xie, Wenhui

    2014-06-07

    The K{sub 2}NiF{sub 4}-type structure La{sub 4}CoNiO{sub 8} (LCNO), La{sub 4}FeCoO{sub 8} (LFCO), and La{sub 4}FeNiO{sub 8} (LFNO) are studied by using the first-principle electronic structure calculations. Our results indicate that the ground state of LCNO is a ferrimagnetism (FiM) with a large energy gap about 1.9?eV, LFCO and LFNO are antiferromagnetism with energy gaps about 1.3 and 1.4?eV, respectively. Their orthorhombic distortions, out-of-plane elongation, and tilting of octahedron are discussed. It is indicated that LFCO and LFNO have stronger crystal distortion than LCNO. Our calculations indicate that the in-plane magnetic exchange interaction of LCNO is much stronger than LFCO and LFNO, thus LCNO should have much higher magnetic ordering temperature than LFCO and LFNO.

  4. Alternating magnetic anisotropy of Li2(Li1–xTx)N(T=Mn,Fe,Co,andNi)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jesche, A.; Ke, L.; Jacobs, J. L.; Harmon, B.; Houk, R. S.; Canfield, P. C.

    2015-05-11

    Substantial amounts of the transition metals Mn, Fe, Co, and Ni can be substituted for Li in single crystalline Li2(Li1–xTx)N. Isothermal and temperature-dependent magnetization measurements reveal local magnetic moments with magnitudes significantly exceeding the spin-only value. The additional contributions stem from unquenched orbital moments that lead to rare-earth-like behavior of the magnetic properties. Accordingly, extremely large magnetic anisotropies have been found. Most notably, the magnetic anisotropy alternates as easy plane?easy axis?easy plane?easy axis when progressing from T = Mn ? Fe ? Co ? Ni. This behavior can be understood based on a perturbation approach in an analytical, single-ion model.more »As a result, the calculated magnetic anisotropies show surprisingly good agreement with the experiment and capture the basic features observed for the different transition metals.« less

  5. Alternating magnetic anisotropy of Li 2 ( Li 1 - x T x ) N ( T = Mn , Fe , Co , and Ni )

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jesche, A.; Ke, L.; Jacobs, J. L.; Harmon, B.; Houk, R. S.; Canfield, P. C.

    2015-05-01

    Substantial amounts of the transition metals Mn, Fe, Co, and Ni can be substituted for Li in single crystalline Li?(Li1-xTx)N. Isothermal and temperature-dependent magnetization measurements reveal local magnetic moments with magnitudes significantly exceeding the spin-only value. The additional contributions stem from unquenched orbital moments that lead to rare-earth-like behavior of the magnetic properties. Accordingly, extremely large magnetic anisotropies have been found. Most notably, the magnetic anisotropy alternates as easy plane?easy axis?easy plane?easy axis when progressing from T = Mn ? Fe ? Co ? Ni. This behavior can be understood based on a perturbation approach in an analytical, single-ion model.more »The calculated magnetic anisotropies show surprisingly good agreement with the experiment and capture the basic features observed for the different transition metals.« less

  6. Ni(III)/(IV) Bis(dicarbollide) as a Fast, Noncorrosive Redox Shuttle for Dye-Sensitized Solar Cells

    SciTech Connect (OSTI)

    Li, Tina C.; Spokoyny, Alexander M.; She, Chunxing; Farha, Omar K.; Mirkin, Chad; Marks, Tobin J.; Hupp, Joseph T.

    2010-01-01

    Nickel bis(dicarbollide) is used as a fast, one-electron outer sphere redox couple in dye-sensitized solar cells. Device performances with this anionic shuttle are investigated with different electrolyte concentrations and additives, using only 0.030 M of the Ni(III) bis(dicarbollide) to efficiently regenerate the ruthenium dye. Atomic layer deposition of Al{sub 2}O{sub 3} on the nanoparticulate TiO{sub 2} photoanodes is further used to improve device performances, increasing current densities almost 2-fold and attaining power conversion efficiencies 10× greater than its metallocene analogue, ferrocene/ferrocenium. Open-circuit voltage decay is used to probe the kinetics of the Ni(III)/(IV) bis(dicarbollide) redox couple, and electron interception is found to be 10{sup 3}× slower than ferrocene/ferrocenium, explaining the large discrepancy in open-circuit voltage potentials between these two redox shuttles.

  7. Ni(III)/(IV) Bis(dicarbollide) as a Fast, Noncorrosive Redox Shuttle for Dye-Sensitized Solar Cells

    SciTech Connect (OSTI)

    Li, Tina C. [Northwestern Univ., Evanston, IL (United States); Spokoyny, Alexander M. [Northwestern Univ., Evanston, IL (United States); Chunxing, She [Northwestern Univ., Evanston, IL (United States); Farha, Omar K. [Northwestern Univ., Evanston, IL (United States); Mirkin, Chad A. [Northwestern Univ., Evanston, IL (United States); Marks, Tobin J. [Northwestern Univ., Evanston, IL (United States); Hupp, Joseph T. [Northwestern Univ., Evanston, IL (United States)

    2010-01-01

    Nickel bis(dicarbollide) is used as a fast, one-electron outer sphere redox couple in dye-sensitized solar cells. Device performances with this anionic shuttle are investigated with different electrolyte concentrations and additives, using only 0.030 M of the Ni(III) bis(dicarbollide) to efficiently regenerate the ruthenium dye. Atomic layer deposition of Al{sub 2}O{sub 3} on the nanoparticulate TiO{sub 2} photoanodes is further used to improve device performances, increasing current densities almost 2-fold and attaining power conversion efficiencies ?10× greater than its metallocene analogue, ferrocene/ferrocenium. Open-circuit voltage decay is used to probe the kinetics of the Ni(III)/(IV) bis(dicarbollide) redox couple, and electron interception is found to be ?10{sup 3}× slower than ferrocene/ferrocenium, explaining the large discrepancy in open-circuit voltage potentials between these two redox shuttles.

  8. Elastic scattering and total reaction cross section for the {sup 6}He+{sup 58}Ni system

    SciTech Connect (OSTI)

    Morcelle, V.; Lichtenthäler, R.; Lépine-Szily, A.; Guimarães, V.; Gasques, L.; Scarduelli, V.; Condori, R. Pampa; Leistenschneider, E.; Mendes Jr, D. R.; Faria, P. N. de; Pires, K. C. C.; Barioni, A.; Morais, M. C.; Shorto, J. M. B.; Zamora, J. C.

    2014-11-11

    Elastic scattering measurements of {sup 6}He + {sup 58}Ni system have been performed at the laboratory energy of 21.7 MeV. The {sup 6}He secondary beam was produced by a transfer reaction {sup 9}Be ({sup 7}Li, {sup 6}He) and impinged on {sup 58}Ni and {sup 197}Au targets, using the Radioactive Ion Beam (RIB) facility, RIBRAS, installed in the Pelletron Laboratory of the Institute of Physics of the University of São Paulo, Brazil. The elastic angular distribution was obtained in the angular range from 15° to 80° in the center of mass frame. Optical model calculations have been performed using a hybrid potential to fit the experimental data. The total reaction cross section was derived.

  9. Spatially resolved penetration depth measurements and vortex manipulation in the ferromagnetic superconductor ErNi2B2C

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wulferding, Dirk; Yang, Ilkyu; Yang, Jinho; Lee, Minkyung; Choi, Hee Cheul; Bud'ko, Sergey L.; Canfield, Paul C.; Yeom, Han Woong; Kim, Jeehoon

    2015-07-31

    We present a local probe study of the magnetic superconductor ErNi2B2C, using magnetic force microscopy at sub-Kelvin temperatures. ErNi2B2C is an ideal system to explore the effects of concomitant superconductivity and ferromagnetism. At 500 mK, far below the transition to a weakly ferromagnetic state, we directly observe a structured magnetic background on the micrometer scale. We determine spatially resolved absolute values of the magnetic penetration depth ? and study its temperature dependence as the system undergoes magnetic phase transitions from paramagnetic to antiferromagnetic, and to weak ferromagnetic, all within the superconducting regime. We estimate the absolute pinning force of Abrikosovmore »vortices, which shows a position dependence and temperature dependence as well, and discuss the possibility of the purported spontaneous vortex formation.« less

  10. Alternating magnetic anisotropy of Li 2 ( Li 1 - x T x ) N ( T = Mn , Fe , Co , and Ni )

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jesche, A.; Ke, L.; Jacobs, J. L.; Harmon, B.; Houk, R. S.; Canfield, P. C.

    2015-05-01

    Substantial amounts of the transition metals Mn, Fe, Co, and Ni can be substituted for Li in single crystalline Li?(Li1-xTx)N. Isothermal and temperature-dependent magnetization measurements reveal local magnetic moments with magnitudes significantly exceeding the spin-only value. The additional contributions stem from unquenched orbital moments that lead to rare-earth-like behavior of the magnetic properties. Accordingly, extremely large magnetic anisotropies have been found. Most notably, the magnetic anisotropy alternates as easy plane?easy axis?easy plane?easy axis when progressing from T = Mn ? Fe ? Co ? Ni. This behavior can be understood based on a perturbation approach in an analytical, single-ion model. The calculated magnetic anisotropies show surprisingly good agreement with the experiment and capture the basic features observed for the different transition metals.

  11. Superconducting epitaxial thin films of CeNi{sub x}Bi{sub 2} with a bismuth square net structure

    SciTech Connect (OSTI)

    Buckow, Alexander; Kupka, Katharina; Retzlaff, Reiner; Kurian, Jose; Alff, Lambert [Institute of Materials Science, Technische Universitaet Darmstadt, 64287 Darmstadt (Germany)

    2012-10-15

    We have grown highly epitaxial and phase pure thin films of the arsenic-free pnictide compound CeNi{sub x}Bi{sub 2} on (100) MgO substrates by reactive molecular beam epitaxy (RMBE). X-ray diffraction and reflection high-energy electron diffraction of the films confirm the ZrCuSiAs structure with a Bi square net layer. Superconductivity was observed in magnetization and resistivity measurements for x= 0.75 to 0.93 in these CeNi{sub x}Bi{sub 2} thin films with the highest critical temperature of 4.05 K and a resistive transition width of 0.1 K for x= 0.86. Our results indicate that thin film deposition by RMBE provides a tool to synthesize high-quality pnictide superconductors of the novel 112 type.

  12. Electron-Transport Properties of Amorphous (Zr0.64ni0.36)1-Xalx Alloys 

    E-Print Network [OSTI]

    BHATNAGAR, AK; PAN, R.; Naugle, Donald G.

    1989-01-01

    .06 ?~x=0.15 ?x=0. 1 0 x=0.20 C; 210- 1.04- OO x =0.25~ . . ::.- -? .~x=0.05 185 . 1.02-. x=0.0~ '- 160 0.1 0.2 0.3 FIG. 2. Room-temperature (300-K) resistivity p as a function of Al concentration x for amorphous (ZrQ 64NiQ 3{j), Al... coefficient 8& for amorphous (ZrQ 64NiQ 36) ) Al . 0 0.05 0.10 0.15 0.20 0.25 0.30 Tcryst (K) 679' 747" 718" 785" 764' 792' 800' T. (K) 2.54' 2.560' 2.68g 2.05' 2.33g 1.62' 1.810 pm (g/cm ) 7.25' 7.10' 6.96' 6.73' 6.53' 6...

  13. Performance of La0.8Sr0.2CoO3 coated NiO as cathodes for molten carbonate fuel cells

    E-Print Network [OSTI]

    Popov, Branko N.

    Performance of La0.8Sr0.2CoO3 coated NiO as cathodes for molten carbonate fuel cells Prabhu Ganesan.2CoO3; Nickel oxide 1. Introduction The molten carbonate fuel cell (MCFC) is a promising power current density of 160 mA/cm2 . The LSC­NiO shows promise as an alternate cathode in molten carbonate fuel

  14. Sr3PbNiO6: Trigonal Prismatic Lead in a Novel Inverse K4CdCl6-type Pseudo-One-Dimensional Oxide

    E-Print Network [OSTI]

    zur Loye, Hans-Conrad

    Sr3PbNiO6: Trigonal Prismatic Lead in a Novel Inverse K4CdCl6-type Pseudo-One-Dimensional Oxide example of lead in the 2H hexagonal perovskite-related family of oxides with the formula A3ABO6 Manuscript Received August 11, 1999 The new one-dimensional oxide Sr3PbNiO6 contains the first reported

  15. Rapid Laser Induced Crystallization of Amorphous NiTi Films Observed by Nanosecond Dynamic Transmission Electron Microscopy (DTEM)

    SciTech Connect (OSTI)

    LaGrange, T; Campbell, G H; Browning, N D; Reed, B W; Grummon, D S

    2010-03-01

    The crystallization processes of the as-deposited, amorphous NiTi thin films have been studied in detail using techniques such as differential scanning calorimetry and, in-situ TEM. The kinetic data have been analyzed in terms of Johnson-Mehl-Avrami-Kolomogrov (JMAK) semi-empirical formula. The kinetic parameters determined from this analysis have been useful in defining process control parameters for tailoring microstructural features and shape memory properties. Due to the commercial push to shrink thin film-based devices, unique processing techniques have been developed using laser-based annealing to spatially control the microstructure evolution down to sub-micron levels. Nanosecond, pulse laser annealing is particularly attractive since it limits the amount of peripheral heating and unwanted microstructural changes to underlying or surrounding material. However, crystallization under pulsed laser irradiation can differ significantly from conventional thermal annealing, e.g., slow heating in a furnace. This is especially true for amorphous NiTi materials and relevant for shape memory thin film based microelectromechanical systems (MEMS) applications. There is little to no data on the crystallization kinetics of NiTi under pulsed laser irradiation, primarily due to the high crystallization rates intrinsic to high temperature annealing and the spatial and temporal resolution limits of standard techniques. However, with the high time and spatial resolution capabilities of the dynamic transmission electron microscope (DTEM) constructed at Lawrence Livermore National Laboratory, the rapid nucleation events occurring from pulsed laser irradiation can be directly observed and nucleation rates can be quantified. This paper briefly explains the DTEM approach and how it used to investigate the pulsed laser induced crystallization processes in NiTi and to determine kinetic parameters.

  16. Strain, interdiffusion, and microstructural evolution under ion irradiation in Ni(111)/Mo(110) multilayers: Interdependence with elastic properties

    SciTech Connect (OSTI)

    Martin, F.; Jaouen, C.; Pacaud, J.; Abadias, G.; Djemia, Ph.; Ganot, F.

    2005-01-15

    The interdependence between the microstructure of sputter-deposited Ni(111)/Mo(110) superlattices and their elastic behavior is investigated as a function of the bilayer period ({lambda}). Brillouin light scattering measurements show that a drastic softening of the effective shear modulus occurs with decreasing {lambda}, until {lambda}=2 nm where it reaches -62%. Ion irradiation is here used to trigger stress relaxation and to induce, in a controlled way, interdiffusion and structural changes allowing us thus to investigate their influence on the elastic anomaly. At a very low irradiation dose (0.1 displacements per atom), the relief of the lattice expansion and associated compressive stresses does not induce any change of the elastic response, which indicates that the elastic behavior of the as-grown multilayers is not correlated with the presence of elastic strains. Furthermore, a detailed x-ray diffraction analysis shows that the unstrained lattice parameter of Mo layers exhibit a linear dependence with the interface density, while the Ni unstrained lattice parameter remains nearly unchanged in the same {lambda} range. This effect can be attributed to an interfacial mixing of a constant Ni amount ({approx}1.5 monolayers) into the Mo layers, as a consequence of a dynamic segregation of Ni atoms during growth. Thus, the formation of interfacial metastable and supersaturated solid solutions, structurally and mechanically unstable, appears as the origin of the huge elastic softening observed in this system. At high ion fluences, when the mixing process becomes dominant, the present study also provides experimental data on phase transformation in 'driven' alloys, by addressing the issue of the stability of out-of-equilibrium structures under irradiation.

  17. Temperature dependence of dynamic Young's modulus and internal friction in three plasma sprayed NiCrAlY coating alloys 

    E-Print Network [OSTI]

    Cook, Lloyd Steven

    1989-01-01

    for internal friction 6. 3 The corstant C TABLE OF CONTENTS (Continued) CONCLUSIONS Page 17 REFERENCES VITA 00 LIST OF TABLES Table l. Alloy Compositions . 2. Measured Densities of Specimens 3. Polynomials for CTE Data 4. Dynamic Young's Modulus... in failure, the mechanical properties of coatings have not been a subject of much concern. Recently, however, plasma sprayed NiCrA1Y coatings have been used as "bond coats", intermediate between an insulating top coat and the protected structural member...

  18. The carburization of transition metal molybdates (MxMoO?, M= Cu, Ni or Co) and the generation of highly active metal/carbide catalysts for CO? hydrogenation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rodriguez, Jose A.; Xu, Wenqian; Ramirez, Pedro J.; Stachiola, Dario; Brito, Joaquin L.

    2015-05-06

    A new approach has been tested for the preparation of metal/Mo?C catalysts using mixed-metal oxide molybdates as precursors. Synchrotron-based in situ time-resolved X-ray diffraction was used to study the reduction and carburization processes of Cu?(MoO?)?(OH)?, a-NiMoO? and CoMoO?•nH?O by thermal treatment under mixtures of hydrogen and methane. In all cases, the final product was ?-Mo?C and a metal phase (Cu, Ni, or Co), but the transition sequence varied with the different metals, and it could be related to the reduction potential of the Cu²?, Ni²? and Co²? cations inside each molybdate. The synthesized Cu/Mo?C, Ni/Mo?C and Co/Mo?C catalysts were highlymore »active for the hydrogenation of CO?. The metal/Mo?C systems exhibited large variations in the selectivity towards methanol, methane and CnH?n?? (n > 2) hydrocarbons depending on the nature of the supported metal and its ability to cleave C-O bonds. Cu/Mo?C displayed a high selectivity for CO and methanol production. Ni/Mo?C and Co/Mo?C were the most active catalysts for the activation and full decomposition of CO?, showing high selectivity for the production of methane (Ni case) and CnH?n?? (n > 2) hydrocarbons (Co case).« less

  19. Characterization of self-propagating formation reactions in Ni/Zr multilayered foils using reaction heats, velocities, and temperature-time profiles

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Barron, S. C.; Knepper, R.; Walker, N.; Weihs, T. P.

    2011-01-11

    We report on intermetallic formation reactions in vapor-deposited multilayered foils of Ni/Zr with 70 nm bilayers and overall atomic ratios of Ni:Zr, 2 Ni:Zr, and 7 Ni:2 Zr. The sequence of alloy phase formation and the stored energy is evaluated at slow heating rates (~1 K/s) using differential scanning calorimetry (DSC) traces to 725ºC. All three chemistries initially form a Ni-Zr amorphous phase which crystallizes first to the intermetallic NiZr. The heat of reaction to the final phase is 34-36 kJ/mol atom for all chemistries. Intermetallic formation reactions are also studied at rapid heating rates (greater than 105 K/s) inmore »high temperature, self-propagating reactions which can be ignited in these foils by an electric spark. We find that reaction velocities and maximum reaction temperatures (Tmax) are largely independent of foil chemistry at 0.6 ± 0.1 m/s and 1220 ± 50 K, respectively, and that the measured Tmax is more than 200 K lower than predicted adiabatic temperatures (Tad). The difference between Tmax and Tad is explained by the prediction that transformation to the final intermetallic phases occurs after Tmax and results in the release of 20-30 % of the total heat of reaction and a delay in rapid cooling.« less

  20. The carburization of transition metal molybdates (MxMoO?, M= Cu, Ni or Co) and the generation of highly active metal/carbide catalysts for CO? hydrogenation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rodriguez, Jose A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Xu, Wenqian [Brookhaven National Lab. (BNL), Upton, NY (United States); Ramirez, Pedro J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Univ. Central De Venezuela, Caracas (Venesuela); Stachiola, Dario [Brookhaven National Lab. (BNL), Upton, NY (United States); Brito, Joaquin L. [Inst. Venezolano de Investigaciones Cientificas, Caracas (Venezuela)

    2015-05-06

    A new approach has been tested for the preparation of metal/Mo?C catalysts using mixed-metal oxide molybdates as precursors. Synchrotron-based in situ time-resolved X-ray diffraction was used to study the reduction and carburization processes of Cu?(MoO?)?(OH)?, a-NiMoO? and CoMoO?•nH?O by thermal treatment under mixtures of hydrogen and methane. In all cases, the final product was ?-Mo?C and a metal phase (Cu, Ni, or Co), but the transition sequence varied with the different metals, and it could be related to the reduction potential of the Cu²?, Ni²? and Co²? cations inside each molybdate. The synthesized Cu/Mo?C, Ni/Mo?C and Co/Mo?C catalysts were highly active for the hydrogenation of CO?. The metal/Mo?C systems exhibited large variations in the selectivity towards methanol, methane and CnH?n?? (n > 2) hydrocarbons depending on the nature of the supported metal and its ability to cleave C-O bonds. Cu/Mo?C displayed a high selectivity for CO and methanol production. Ni/Mo?C and Co/Mo?C were the most active catalysts for the activation and full decomposition of CO?, showing high selectivity for the production of methane (Ni case) and CnH?n?? (n > 2) hydrocarbons (Co case).

  1. A Unified Energy-Reservoir Model Containing Contributions from $^{56}$Ni and Neutron Stars and Its Implication to Luminous Type Ic Supernovae

    E-Print Network [OSTI]

    Wang, S Q; Dai, Z G; Wu, X F

    2015-01-01

    Most type-Ic core-collapse supernovae (CCSNe) produce $^{56}$Ni and neutron stars (NSs) or black holes (BHs). The dipole radiation of nascent NSs has usually been neglected in explaining supernovae (SNe) with peak absolute magnitude $M_{\\rm peak}$ in any band are $\\gtrsim -19.5$~mag, while the $^{56}$Ni can be neglected in fitting most type-Ic superluminous supernovae (SLSNe Ic) whose $M_{\\rm peak}$ in any band are $\\lesssim -21$~mag, since the luminosity from a magnetar (highly magnetized NS) can outshine that from a moderate amount of $^{56}$Ni. For luminous SNe Ic with $-21 \\lesssim M_{\\rm peak}\\lesssim -19.5$~mag, however, both contributions from $^{56}$Ni and NSs cannot be neglected without serious modeling, since they are not SLSNe and the $^{56}$Ni mass could be up to $\\sim 0.5 M_{\\odot}$. In this paper we propose a unified model that contain contributions from both $^{56}$Ni and a nascent NS. We select three luminous SNe Ic-BL, SN~2010ay, SN~2006nx, and SN~14475, and show that, if these SNe are powere...

  2. Characterization of self-propagating formation reactions in Ni/Zr multilayered foils using reaction heats, velocities, and temperature-time profiles

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Barron, S. C.; Knepper, R.; Walker, N.; Weihs, T. P.

    2011-01-11

    We report on intermetallic formation reactions in vapor-deposited multilayered foils of Ni/Zr with 70 nm bilayers and overall atomic ratios of Ni:Zr, 2 Ni:Zr, and 7 Ni:2 Zr. The sequence of alloy phase formation and the stored energy is evaluated at slow heating rates (~1 K/s) using differential scanning calorimetry (DSC) traces to 725ºC. All three chemistries initially form a Ni-Zr amorphous phase which crystallizes first to the intermetallic NiZr. The heat of reaction to the final phase is 34-36 kJ/mol atom for all chemistries. Intermetallic formation reactions are also studied at rapid heating rates (greater than 105 K/s) in high temperature, self-propagating reactions which can be ignited in these foils by an electric spark. We find that reaction velocities and maximum reaction temperatures (Tmax) are largely independent of foil chemistry at 0.6 ± 0.1 m/s and 1220 ± 50 K, respectively, and that the measured Tmax is more than 200 K lower than predicted adiabatic temperatures (Tad). The difference between Tmax and Tad is explained by the prediction that transformation to the final intermetallic phases occurs after Tmax and results in the release of 20-30 % of the total heat of reaction and a delay in rapid cooling.

  3. A Platinum-Enriched gamma+gamma' Two-Phase Bond Coat on Ni-Base Superalloys

    SciTech Connect (OSTI)

    Zhang, Ying [Tennessee Technological University; Pint, Bruce A [ORNL; Haynes, James A [ORNL; Wright, Ian G [ORNL

    2005-01-01

    Pt-enriched {gamma} + {gamma}{prime} two-phase coating was applied to directionally-solidified Ni-based superalloy Ren{acute e} 142 substrates with three different Hf levels (0.02, 0.76, and 1.37 wt.%). The coating was prepared by electroplating a thin layer of Pt on the superalloy followed by a diffusion treatment. The as-deposited coating exhibited a {gamma} + {gamma}{prime} two-phase microstructure with a major composition of Ni-16Al-18Pt-7Cr-9Co (in at.%) along with some incorporation of refractory elements from the substrates. Cyclic oxidation testing at 1100 C in air indicated improved oxidation resistance of the Ren{acute e} 142 alloys with the Pt-enriched {gamma} + {gamma}{prime} coatings. In addition, the oxidation resistance of both uncoated and coated alloys was proportional to the Hf content in the substrate. Compared with the single-phase {beta}-(Ni,Pt)Al coating, slightly higher mass gains and localized spallation were observed on the {gamma} + {gamma}{prime} two-phase coating, which might be due to the segregation of refractory elements and high sulfur levels in these superalloy substrates.

  4. Microstructure–property relationships in a high-strength 51Ni–29Ti–20Hf shape memory alloy

    SciTech Connect (OSTI)

    Coughlin, D. R.; Casalena, L.; Yang, F.; Noebe, R. D.; Mills, M. J.

    2015-09-18

    NiTiHf alloys exhibit remarkable shape memory and pseudoelastic properties that are of fundamental interest to a growing number of industries. In this study, differential scanning calorimetry and isothermal compression tests have revealed that the 51Ni–29Ti–20Hf alloy has useful shape memory properties that include a wide range of transformation temperatures as well as highly stable pseudoelastic behavior. These properties are governed by short-term aging conditions, which may be tailored to control transformation temperatures while giving rise to exceptionally high austenite yield strengths which aid transformation stability. The yield strength of the austenite phase can reach 2.1 GPa by aging for 3hrs at 500°C, while aging for 3hrs at 700°C produced an alloy with an austenite finish temperature (A f ) of 146°C. High-resolution scanning transmission electron microscopy has revealed a new precipitate phase, H-phase, under the homogenized and extruded condition and the aged 3 hrs at 500°C condition, but only the previously identified H-phase precipitate was observed after aging at temperatures of 600°C and 700°C for 3 hrs. Finally, dislocation analysis indicated that plastic deformation of the austenite phase occurred by <100> type slip, similar to that observed in binary NiTi.

  5. Microstructure–property relationships in a high-strength 51Ni–29Ti–20Hf shape memory alloy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Coughlin, D. R.; Casalena, L.; Yang, F.; Noebe, R. D.; Mills, M. J.

    2015-09-18

    NiTiHf alloys exhibit remarkable shape memory and pseudoelastic properties that are of fundamental interest to a growing number of industries. In this study, differential scanning calorimetry and isothermal compression tests have revealed that the 51Ni–29Ti–20Hf alloy has useful shape memory properties that include a wide range of transformation temperatures as well as highly stable pseudoelastic behavior. These properties are governed by short-term aging conditions, which may be tailored to control transformation temperatures while giving rise to exceptionally high austenite yield strengths which aid transformation stability. The yield strength of the austenite phase can reach 2.1 GPa by aging for 3hrsmore »at 500°C, while aging for 3hrs at 700°C produced an alloy with an austenite finish temperature (A f ) of 146°C. High-resolution scanning transmission electron microscopy has revealed a new precipitate phase, H-phase, under the homogenized and extruded condition and the aged 3 hrs at 500°C condition, but only the previously identified H-phase precipitate was observed after aging at temperatures of 600°C and 700°C for 3 hrs. Finally, dislocation analysis indicated that plastic deformation of the austenite phase occurred by type slip, similar to that observed in binary NiTi.« less

  6. Preparation and characterization of Ni(111)/graphene/Y{sub 2}O{sub 3}(111) heterostructures

    SciTech Connect (OSTI)

    Dahal, Arjun; Coy-Diaz, Horacio; Addou, Rafik; Lallo, James; Batzill, Matthias; Sutter, Eli

    2013-05-21

    Integration of graphene with other materials by direct growth, i.e., not using mechanical transfer procedures, is investigated on the example of metal/graphene/dielectric heterostructures. Such structures may become useful in spintronics applications using graphene as a spin-filter. Here, we systematically discuss the optimization of synthesis procedures for every layer of the heterostructure and characterize the material by imaging and diffraction methods. 300 nm thick contiguous (111) Ni-films are grown by physical vapor deposition on YSZ(111) or Al{sub 2}O{sub 3}(0001) substrates. Subsequently, chemical vapor deposition growth of graphene in ultra-high vacuum (UHV) is compared to tube-furnace synthesis. Only under UHV conditions, monolayer graphene in registry with Ni(111) has been obtained. In the tube furnace, mono- and bilayer graphene is obtained at growth temperatures of {approx}800 Degree-Sign C, while at 900 Degree-Sign C, non-uniform thick graphene multilayers are formed. Y{sub 2}O{sub 3} films grown by reactive molecular beam epitaxy in UHV covers the graphene/Ni(111) surface uniformly. Annealing to 500 Degree-Sign C results in crystallization of the yttria with a (111) surface orientation.

  7. Enhanced magnetic moment and conductive behavior in NiFe{sub 2}O{sub 4} spinel ultrathin films

    SciTech Connect (OSTI)

    Lueders, Ulrike [Institut de Ciencia de Materials de Barcelona, CSIC, Campus de la UAB, 08193 Bellaterra, Catalunya (Spain); LPMC-FRE2686 CNRS-ONERA, 2 avenue Edouard Belin, 31400 Toulouse (France); Bibes, Manuel [Unite Mixte de Physique THALES/CNRS, Domaine de Corbeville, 91404 Orsay (France); Institut d'Electronique Fondamentale, Universite Paris-Sud, 91405 Orsay (France); Bobo, Jean-Francois [LPMC-FRE2686 CNRS-ONERA, 2 avenue Edouard Belin, 31400 Toulouse (France); Cantoni, Matteo; Bertacco, Riccardo [INFM and L-NESS, Dipartimento di Fisica del Politecnico di Milano, via Anzani 52, 22100 Como (Italy); Fontcuberta, Josep [Institut de Ciencia de Materials de Barcelona, CSIC, Campus de la UAB, 08193 Bellaterra, Catalunya (Spain)

    2005-04-01

    Bulk NiFe{sub 2}O{sub 4} is an insulating ferrimagnet. Here, we report on the epitaxial growth of spinel NiFe{sub 2}O{sub 4} ultrathin films onto SrTiO{sub 3} single crystals. We will show that--under appropriate growth conditions--epitaxial stabilization leads to the formation of a spinel phase with magnetic and electrical properties that radically differ from those of the bulk material: an enhanced magnetic moment (M{sub S})--about 250% larger--and a metallic character. A systematic study of the thickness dependence of M{sub S} allows us to conclude that its enhanced value is due to an anomalous distribution of the Fe and Ni cations among the A and B sites of the spinel structure resulting from the off-equilibrium growth conditions and to interface effects. The relevance of these findings for spinel- and, more generally, oxide-based heterostructures is discussed. We will argue that this novel material could be an alternative ferromagetic-metallic electrode in magnetic tunnel junctions.

  8. Single crystal neutron diffraction study of the magnetic structure of TmNi{sub 2}B{sub 2}C

    SciTech Connect (OSTI)

    Sternlieb, B.; Shapiro, S.; Stassis, C.; Goldman, A.I.; Canfield, P.

    1997-02-01

    Neutron diffraction techniques have been used to study the magnetic structure of single crystals of the magnetic superconductor (T{sub c} {congruent} 11K) TmNi{sub 2}B{sub 2}C. We find that below approximately 1.5K the magnetic moments order in an incommensurate spin wave with propagation vector q{sub m} = q{sub m} (a* +b*) (or q{sub m} = q{sub m} (a* + b*)) with q{sub m} = 0.094 {+-} 0.001. The spin wave is transverse with the moments aligned along the c-axis, and the observation of relatively intense higher order harmonics shows that the modulation is not purely sinusoidal but considerably squared. This incommensurate magnetic structure, which coexists with superconductivity below T{sub N} {congruent} 1.5K, is quite different from those observed in the magnetic superconductors HoNi{sub 2}B{sub 2}C and ErNi{sub 2}B{sub 2}C. The origin of diffraction peaks observed in scans parallel to a* is briefly discussed.

  9. Post-doctoral Data Analyst University of Michigan Company Information: The University of Michigan Kidney Epidemiology and Cost Center (UM-

    E-Print Network [OSTI]

    Shepp, Larry

    Post-doctoral Data Analyst University of Michigan Company Information: The University of Michigan Kidney Epidemiology and Cost Center (UM- KECC) is an interdisciplinary research group drawing from-doctoral Data Analyst Duties & Responsibilities: We are inviting applicants to a Post-doctoral Data Analyst

  10. Einstein apaixonado: A cincia mal-contada de um mito bem-traado Carlos Alberto dos Santos

    E-Print Network [OSTI]

    dos Santos, C.A.

    . (...) A luz de junho explode através das janelas que dão para a Unionstrasse, no coração do lendário e "a nova teoria das ondas de luz de James Clerk Maxwell" e a controvérsia em torno da natureza da luz fazer com que os raios catódicos, isto é, os elétrons, fossem emitidos de um metal expondo-o à luz

  11. Quasielastic transfer in the {sup 136}Xe+{sup 64}Ni reaction

    SciTech Connect (OSTI)

    Sanders, S.J.; Dummer, A.K.; Farrar, K.A.; Prosser, F.W. [Department of Physics and Astronomy, The University of Kansas, Lawrence, Kansas 66045 (United States)] [Department of Physics and Astronomy, The University of Kansas, Lawrence, Kansas 66045 (United States); Fornal, B. [Purdue University, West Lafayette, Indiana 47907 (United States)] [Purdue University, West Lafayette, Indiana 47907 (United States); [The Institute for Nuclear Physics, Cracow (Poland); Janssens, R.V.; Carpenter, M.P.; Khoo, T.L. [Argonne National Laboratory, Argonne, Illinois 60439 (United States)] [Argonne National Laboratory, Argonne, Illinois 60439 (United States); Beck, C.; Mahboub, D.; Haas, F. [Centre de Recherches Nucleaires, IN2P3-CNRS/Universite Louis Pasteur, Boite Postal 22, F-67037 Strasbourg Cedex 2 (France)] [Centre de Recherches Nucleaires, IN2P3-CNRS/Universite Louis Pasteur, Boite Postal 22, F-67037 Strasbourg Cedex 2 (France); Cavallaro, S. [Dipartimento di Fisica dell`Universita di Catania and Laboratorio Nazionale del Sud, I-95129, Catania (Italy)] [Dipartimento di Fisica dell`Universita di Catania and Laboratorio Nazionale del Sud, I-95129, Catania (Italy); Sferrazza, M.; Mayer, R.; Nisius, D. [Purdue University, West Lafayette, Indiana 47907 (United States)] [Purdue University, West Lafayette, Indiana 47907 (United States); de Angelis, G. [Istituto Nazionali di Fisica Nucleare, Laboratori Nazionali di Legnaro, Legnaro (Italy)] [Istituto Nazionali di Fisica Nucleare, Laboratori Nazionali di Legnaro, Legnaro (Italy)

    1997-05-01

    Single and multinucleon transfer yields for the {sup 136}Xe+{sup 64}Ni reaction at a scattering energy {approx}5{percent} above the Coulomb barrier energy are studied using particle{endash}{gamma}-ray coincidence data. Q-value and scattering-angle distributions are extracted for the stronger channels. A fast transfer mechanism dominates the yields to these channels over an extended Q-value range, leading to a concentration of the cross section near the grazing angle. Analysis of the angular distributions based on a semiclassical barrier penetration model suggests that the single-nucleon and two-neutron exchange channels are dominated, respectively, by direct and two-step sequential transfer from the ground or low-lying excited states of the participating nuclei. The multiproton transfer channels have angular distributions that indicate a more complex mechanism, although direct cluster transfer from an excited configuration cannot be fully discounted. In a separate analysis, the relative population of different mass channels is found to be in general agreement with the expectations of a {open_quotes}random walk{close_quotes} model of particle exchange. {copyright} {ital 1997} {ital The American Physical Society}

  12. Modified magnetic ground state in NiMn2O4 thin films

    SciTech Connect (OSTI)

    Nelson-Cheeseman, B. B.; Chopdekar, R. V.; Toney, M. F.; Arenholz, E.; Suzuki, Y.; Iwata, J.M.

    2010-08-03

    We demonstrate the stabilization of a magnetic ground state in epitaxial NiMn2O4 (NMO) thin films not observed in their bulk counterpart. Bulk NMO exhibits a magnetic transition from a paramagnetic phase to a collinear ferrimagnetic moment configuration below 110 K and to a canted moment configuration below 70 K. By contrast, as-grown NMO films exhibit a single magnetic transition at 60 K and annealed films exhibit the magnetic behavior found in bulk. Cation inversion and epitaxial strain are ruled out as possible causes for the new magnetic ground state in the as-grown films. However, a decrease in the octahedral Mn{sup 4+}:Mn{sup 3+} concentration is observed and likely disrupts the double exchange that produces the magnetic state at intermediate temperatures. X-ray magnetic circular dichroism and bulk magnetometry indicate a canted ferrimagnetic state in all samples at low temperature. Together these results suggest that the collinear ferrimagnetic state observed in bulk NMO at intermediate temperatures is suppressed in the as grown NMO thin films due to a decrease in octahedral Mn{sup 4+} while the canted moment ferrimagnetic ordering is preserved below 60 K.

  13. Effective core potential investigation of Ni, Pd, and Pt and their monohydrides

    SciTech Connect (OSTI)

    Rohlfing, C.M.; Hay, P.J.; Martin, R.L.

    1986-08-01

    The nickel, palladium, and platinum atoms and their monohydrides are investigated using effective core potentials (ECP's) recently introduced by Hay and Wadt (J. Chem. Phys. 82, 270, 299 (1985)). The palladium and platinum ECP's include relativistic effects. Two types of ECP's, which differ in their definition of the core region, are used in conjunction with large valence basis sets including f-italic functions. Electron correlation is incorporated by Mo-dash-barller--Plesset perturbation theory through fourth order. The results demonstrate the success of the ECP approximation: they are similar in quality to those of all-electron studies and at the same time are achieved at a reduced computational cost. Total correlation energies obtained with both types of ECP's are compared, and are found to be very sensitive to details of the basis set. Correlation effects are treated more consistently by the ECP's which include the outermost core orbitals in the valence region. The relative ordering of molecular states is calculated to be /sup 2/..delta..NiH, /sup 2/..sigma../sup +/ < /sup 2/..delta.. < /sup 2/Pi for PdH, and /sup 2/..delta..roughly-equal/sup 2/..sigma../sup +/

  14. Deformation and fracture behavior of composite structured Ti-Nb-Al-Co(-Ni) alloys

    SciTech Connect (OSTI)

    Okulov, I. V. Marr, T.; Schultz, L.; Eckert, J.; Kühn, U.; Freudenberger, J.; Oertel, C.-G.; Skrotzki, W.

    2014-02-17

    Tensile ductility of the Ti-based composites, which consist of a ?-Ti phase surrounded by ultrafine structured intermetallics, is tunable through the control of intermetallics. The two Ti-based alloys studied exhibit similar compressive yield strength (about 1000?MPa) and strain (about 35%–40%) but show a distinct difference in their tensile plasticity. The alloy Ti{sub 71.8}Nb{sub 14.1}Ni{sub 7.4}Al{sub 6.7} fractures at the yield stress while the alloy Ti{sub 71.8}Nb{sub 14.1}Co{sub 7.4}Al{sub 6.7} exhibits about 4.5% of tensile plastic deformation. To clarify the effect of microstructure on the deformation behavior of these alloys, tensile tests were carried out in the scanning electron microscope. It is shown that the distribution as well as the type of intermetallics affects the tensile ductility of the alloys.

  15. First ground-based 200-um observing with THUMPER on JCMT - sky characterisation and planet maps

    E-Print Network [OSTI]

    D. Ward-Thompson; P. A. R. Ade; H. Araujo; I. Coulson; J. Cox; G. R. Davis; Rh. Evans; M. J. Griffin; W. K. Gear; P. Hargrave; P. Hargreaves; D. Hayton; B. J. Kiernan; S. J. Leeks; P. Mauskopf; D. Naylor; N. Potter; S. A. Rinehart; R. Sudiwala; C. R. Tucker; R. J. Walker; S. L. Watkin

    2005-09-22

    We present observations that were carried out with the Two HUndred Micron PhotometER (THUMPER) mounted on the James Clerk Maxwell Telescope (JCMT) in Hawaii, at a wavelength of 200 um (frequency 1.5 THz). The observations utilise a small atmospheric window that opens up at this wavelength under very dry conditions at high-altitude observing sites. The atmosphere was calibrated using the sky-dipping method and a relation was established between the optical depth, tau, at 1.5 THz and that at 225 GHz: tau_1.5THz = (95 +/- 10)*tau_225GHz. Mars and Jupiter were mapped from the ground at this wavelength for the first time, and the system characteristics measured. A noise equivalent flux density (NEFD) of ~65 +/- 10 Jy (1 sigma 1 second) was measured for the THUMPER-JCMT combination, consistent with predictions based upon our laboratory measurements. The main-beam resolution of 14 arcsec was confirmed and an extended error-beam detected at roughly two-thirds of the magnitude of the main beam. Measurements of the Sun allow us to estimate that the fraction of the power in the main beam is ~15%, consistent with predictions based on modelling the dish surface accuracy. It is therefore shown that the sky over Mauna Kea is suitable for astronomy at this wavelength under the best conditions. However, higher or drier sites should have a larger number of useable nights per year.

  16. Brazing ZrO{sub 2} ceramic to Ti–6Al–4V alloy using NiCrSiB amorphous filler foil: Interfacial microstructure and joint properties

    SciTech Connect (OSTI)

    Cao, J., E-mail: cao_jian@hit.edu.cn [Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Song, X.G., E-mail: song_xiaoguohit@yahoo.com.cn [Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Li, C., E-mail: li_chun1989@yahoo.cn [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Zhao, L.Y., E-mail: Zhao_ly@163.com [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Feng, J.C., E-mail: feng_jicai@163.com [Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China)

    2013-07-15

    Reliable brazing of ZrO{sub 2} ceramic and Ti–6Al–4V alloy was achieved using NiCrSiB amorphous filler foil. The interfacial microstructure of ZrO{sub 2}/Ti–6Al–4V joints was characterized by scanning electron microscope, energy dispersive spectrometer and micro-focused X-ray diffractometer. The effects of brazing temperature on the interfacial microstructure and joining properties of brazed joints were investigated in detail. Active Ti of Ti–6Al–4V alloy dissolved into molten filler metal and reacted with ZrO{sub 2} ceramic to form a continuous TiO reaction layer, which played an important role in brazing. Various reaction phases including Ti{sub 2}Ni, Ti{sub 5}Si{sub 3} and ?-Ti were formed in brazed joints. With an increasing of brazing temperature, the TiO layer thickened gradually while the Ti{sub 2}Ni amount reduced. Shear test indicated that brazed joints tend to fracture at the interface between ZrO{sub 2} ceramic and brazing seam or Ti{sub 2}Ni intermetallic layer. The maximum average shear strength reached 284.6 MPa when brazed at 1025 °C for 10 min. - Graphical Abstract: Interfacial microstructure of ZrO{sub 2}/TC4 joint brazed using NiCrSiB amorphous filler foil was: ZrO{sub 2}/TiO/Ti{sub 2}Ni + ?-Ti + Ti{sub 5}Si{sub 3}/?-Ti/Widmanstätten structure/TC4. - Highlights: • Brazing of ZrO{sub 2} ceramic and Ti-6Al-4V alloy was achieved. • Interfacial microstructure was TiO/Ti{sub 2}Ni + ? + Ti{sub 5}Si{sub 3}/?/Widmanstätten structure. • The formation of TiO produced the darkening effect of ZrO{sub 2} ceramic. • The highest joining strength of 284.6MPa was obtained.

  17. MATTER MIXING IN ASPHERICAL CORE-COLLAPSE SUPERNOVAE: A SEARCH FOR POSSIBLE CONDITIONS FOR CONVEYING {sup 56}Ni INTO HIGH VELOCITY REGIONS

    SciTech Connect (OSTI)

    Ono, Masaomi; Nagataki, Shigehiro; Ito, Hirotaka; Lee, Shiu-Hang; Mao, Jirong; Tolstov, Alexey [Astrophysical Big Bang Laboratory, RIKEN, Saitama 351-0198 (Japan); Hashimoto, Masa-aki, E-mail: masaomi.ono@riken.jp [Department of Physics, Kyushu University, Fukuoka 812-8581 (Japan)

    2013-08-20

    We perform two-dimensional axisymmetric hydrodynamic simulations of matter mixing in aspherical core-collapse supernova explosions of a 16.3 M{sub Sun} star with a compact hydrogen envelope. Observations of SN 1987A have provided evidence that {sup 56}Ni synthesized by explosive nucleosynthesis is mixed into fast moving matter ({approx}>3500 km s{sup -1}) in the exploding star. In order to clarify the key conditions for reproducing such high velocity of {sup 56}Ni, we revisit matter mixing in aspherical core-collapse supernova explosions. Explosions are initiated artificially by injecting thermal and kinetic energies around the interface between the iron core and the silicon-rich layer. Perturbations of 5% or 30% amplitude in the radial velocities are introduced at several points in time. We find that no high velocity {sup 56}Ni can be obtained if we consider bipolar explosions with perturbations (5% amplitude) of pre-supernova origins. If large perturbations (30% amplitude) are introduced or exist due to some unknown mechanism in a later phase just before the shock wave reaches the hydrogen envelope, {sup 56}Ni with a velocity of 3000 km s{sup -1} can be obtained. Aspherical explosions that are asymmetric across the equatorial plane with clumpy structures in the initial shock waves are investigated. We find that the clump sizes affect the penetration of {sup 56}Ni. Finally, we report that an aspherical explosion model that is asymmetric across the equatorial plane with multiple perturbations of pre-supernova origins can cause the penetration of {sup 56}Ni clumps into fast moving matter of 3000 km s{sup -1}. We show that both aspherical explosions with clumpy structures and perturbations of pre-supernova origins may be necessary to reproduce the observed high velocity of {sup 56}Ni. To confirm this, more robust three-dimensional simulations are required.

  18. Crystal structure and hydrogenation properties of pseudo-binary Mg{sub 6}Pd{sub 0.5}Ni{sub 0.5} complex metallic alloy

    SciTech Connect (OSTI)

    Cuevas, F.; Latroche, M.

    2009-10-15

    The crystal structure of the Ni-substituted Mg{sub 6.10(2)}Pd{sub 0.52(2)}Ni{sub 0.41(2)} complex metallic alloy has been determined by X-ray and neutron powder diffraction. The reaction of this compound at 573 K towards deuterium absorption for pressures up to 23 bar has also been studied. The crystal structure of Mg{sub 6.10(2)}Pd{sub 0.52(2)}Ni{sub 0.41(2)} compound was determined in the light of Samson's [Acta Crystallogr. B 28 (1972) 936) and Makongo's (Philos. Mag. 86 (2006) 427] models for the binary Mg{sub 6}Pd compound. It crystallizes in F4-bar3m space group with lattice parameter 20.13331(7) A. The refined unit-cell composition is Mg{sub 342(1)}Pd{sub 29(1)}Ni{sub 23(1)} with Z=56. Nickel by palladium substitution is not fully random. Nickel atoms preferentially locate on Pd sites with low coordination number due to steric effects. Deuterium uptake is 9.6 D/f.u. under the given conditions of pressure and temperature. Upon absorption, the intermetallic compound disproportionates into MgD{sub 2}, Mg{sub 5}Pd{sub 2} and Mg{sub 2}NiD{sub 4} phases. The Mg{sub 2}NiD{sub 4} phase is observed to crystallize in the orthorhombic LT2 modification for which an averaged crystal structure in the Pcc2 space group is proposed. - Graphical abstract: Coordination polyhedron around site Mg14 in pseudobinary Mg{sub 6}(Pd,Ni) compounds.

  19. Neutron structural characterization, inversion degree and transport properties of NiMn{sub 2}O{sub 4} spinel prepared by the hydroxide route

    SciTech Connect (OSTI)

    Sagua, A.; Lescano, Gabriela M.; Alonso, J.A.; Martínez-Coronado, R.; Fernández-Díaz, M.T.; Morán, E.

    2012-06-15

    Graphical abstract: A pure specimen has been synthesized by the hydroxide route. This spinel, studied by NPD, shows an important inversion degree, ? = 0.80. A bond-valence study shows that the tetrahedral Mn ions are divalent whereas the octahedral Mn and Ni are slightly oxidized from the expected 3+ and 2+ values, respectively. The mixed valence Mn{sup 3+}/Mn{sup 4+} accounts for a hopping mechanism between adjacent octahedral sites, leading to a significant conductivity. Highlights: ? A low-temperature hydroxide route allowed preparing almost pure specimens of NiMn{sub 2}O{sub 4}. ? NPD essential to determine inversion degree; contrasting Ni and Mn for neutrons. ? Bond valence establishes valence state of octahedral and tetrahedral Ni and Mn ions. ? Thermal analysis, transport measurements complement characterization of this oxide. ? A structure–properties relationship is established. -- Abstract: The title compound has been synthesized by the hydroxide route. The crystal structure has been investigated at room temperature from high-resolution neutron powder diffraction (NPD) data. It crystallizes in a cubic spinel structure, space group Fd3{sup ¯}m, Z = 8, with a = 8.3940(2) ? at 295 K. The crystallographic formula is (Ni{sub 0.202(1)}Mn{sub 0.798(1)}){sub 8a}(Ni{sub 0.790(1)}Mn{sub 1.210(1)}){sub 16d}O{sub 4} where 8a and 16d stand for the tetrahedral and octahedral sites of the spinel structure, respectively. There is a significant inversion degree of the spinel structure, ? = 0.80. In fact, the variable parameter for the oxygen position, u = 0.2636(4), is far from that expected (u = 0.25) for normal spinels. From a bond-valence study, it seems that the valence distribution in NiMn{sub 2}O{sub 4} spinel is not as trivial as expected (Ni{sup 2+} and Mn{sup 3+}), but clearly the tetrahedral Mn ions are divalent whereas the octahedral Mn and Ni are slightly oxidized from the expected +3 and +2 values, respectively. The mixed valence observed at the octahedral sites provides the charge carriers that, by a hopping mechanism between Mn{sup 3+}/Mn{sup 4+} adjacent sites, leads to a significant conductivity, up to 0.85 S cm{sup ?1} at 800 °C in air.

  20. Substitution effect on the magnetic and transport properties of CeNi{sub 0.8?x}Mn{sub x}Bi{sub 2}

    SciTech Connect (OSTI)

    Kim, Soo-Whan; Lee, Kyujoon; Jung, Myung-Hwa; Adroja, D. T.; Demmel, F.; Taylor, J. W.

    2014-08-21

    We report the results of Mn substitution for Ni in CeNi{sub 0.8}Bi{sub 2} (i.e., CeNi{sub 0.8?x}Mn{sub x}Bi{sub 2}). All the samples have an antiferromagnetic ordered state below T{sub N}?=?5.0?K due to localized 4f-magnetic moment on the Ce ions. Besides this antiferromagnetic ordering caused by Ce, the magnetic and transport properties are abruptly changed with increasing Mn contents at the boundary composition of x?=?0.4. The magnetic state is changed into a ferromagnetic state around 200?K for x?>?0.4, where the electrical resistivity is strongly suppressed to become simple metallic. These results of ferromagnetism and metallicity can be explained by the double exchange mechanism, rather than the simple picture of Doniach phase diagram. The mixed valence states of Ni and Mn ions are confirmed by X-ray photoelectron spectroscopy. For x???0.4, the initial Ni{sup 3+} state gradually changes to the Ni{sup 2+} state with increasing x up to 0.4. On further increase of x?>?0.4, the Ni{sup 2+} state is replaced by the Mn{sup 2+} state, which gradually changes to the final Mn{sup 3+} state. We also present an inelastic neutron scattering (INS) measurements on CeNi{sub 0.8}Bi{sub 2} (i.e., x?=?0) between 1.2 and 12?K. The high energy INS study reveals the presence of two well-defined crystal electric field (CEF) excitations near 9?meV and 19?meV at 1.2?K and 6?K, while the low energy INS study reveals the presence of quasielastic scattering above 4?K. We will discuss our INS results of CeNi{sub 0.8}Bi{sub 2} based on the CEF model.