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in subjects: "Palladium"

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Phonon-limited lifetimes of electrons in Pd

Quasiparticle lifetimes 1/tau/sub k/ are calculated for electrons on the Fermi surface (FS) of Pd using the rigid muffin tin model. Results are presented for the gamma-centered and the open sheets.

Date: January 1, 1981

Creator: Khan, F. S.; Allen, P. B. & Butler, W. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Formation and characterization of highly-dispersed metal colloid catalysts

The objective of this research is to explore the feasibility of using small metal colloids, in microemulsions, as catalysts. The product of this work will be a new concept for tailoring highly dispersed materials to specific catalytic reactions. The knowledge gained from the proposed research will be broadly applicable to variety of reactions, including hydrogenation, synthesis gas conversion, and hydrogen conversion. To achieve this objective, a plan has been formulated to prepare and characte… more

Date: January 1, 1991

Creator: Wilcoxon, J.; Martino, A.; Nigrey, P.; Sylwester, A.; Klavetter, E. & Baughman, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Metal hydride based isotope separation: Large-scale operations

A program to develop a metal hydride based hydrogen isotope separation process began at the Savannah River Laboratory in 1980. This semi-continuous gas chromatographic separation process will be used in new tritium facilities at the Savannah River Site. A tritium production unit is scheduled to start operation in 1993. An experimental, large-scale unit is currently being tested using protium and deuterium. Operation of the large-scale unit has demonstrated separation of mixed hydrogen isotopes … more

Date: January 1, 1991

Creator: Horen, A.S. & Lee, Myung W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Effect of dissipation on dynamical fusion thresholds

The existence of dynamical thresholds to fusion in heavy nuclei (A greater than or equal to 200) due to the nature of the potential-energy surface is shown. These thresholds exist even in the absence of dissipative forces, due to the coupling between the various collective deformation degrees of freedom. Using a macroscopic model of nuclear shape dynamics, It is shown how three different suggested dissipation mechanisms increase by varying amounts the excitation energy over the one-dimensional … more

Date: January 1, 1986

Creator: Sierk, A.J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Experiments on a ceramic electrolysis cell and a palladium diffuser at the tritium systems test assembly

A ceramic electrolysis cell and a palladium diffuser are developed in Japan and is tested with tritium in Tritium Systems Test Assembly (TSTA) of the Los Alamos National Laboratory, in order to confirm the feasibility as possible upgrades for the fuel cleanup system (PCU). The ceramic electrolysis cell made of stabilized zirconia was operated at 630/sup 0/C for an extended period with a mixture of 3% T/sub 2/O in He carrier gas in the circulation system with oxidizing catalyst bed. The palladiu… more

Date: January 1, 1985

Creator: Konishi, Satoshi; Yoshida, Hiroshi; Ohno, Hideo; Naruse, Yuji; Coffin, D.O.; Walthers, C.R. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Phase 2 of the Array Automated Assembly Task for the Low Cost Solar Array Project. Quarterly report 5, October 1-December 31, 1978

Various top contact metal systems have been studied. Only Ti-Pd-Cu approaches baseline (Ti-Pd-Ag) quality, but this system shows a lack of long-term stability. Aluminum back surface field structures have been fabricated and thicknesses of p/sup +/ material of up to 7.0 microns have been achieved with open circuit voltages of 0.59V. A general purpose ultrasonic welder has been purchased and tests using various metal foils are under way. During fabrication of the demonstration module, several cel… more

Date: January 31, 1979

Creator: Campbell, R. B.; Page, D. J.; Rai-Choudhury, P.; Seman, E. J.; Hanes, M. H.; Rohatgi, A. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Atomic and electronic structure of metals and alloys: Clean surfaces and chemisorbed molecules

The accomplishments of the work done under DOE sponsorship are summarized in the list of publications at the end of this narrative. Here we give a brief description of the nature and the significance of the accomplishments. The activity can be roughly subdivided into three parts: studies of surface alloys, studies of epitaxial ultra-thin films, and studies of electron band structure of metals. The list reflects the developments of particular areas of research and the phasing out of others as th… more

Date: November 26, 1991

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Tensile strength and creep resistance in nanocrystalline Cu, Pd and Ag

Measurements of tensile strength and creep resistance have been made on bulk samples of nanocrystalline Cu, Pd and Ag consolidated from powders by cold compaction. Samples of Cu-Cu{sub 2}O have also been tested. Yield strength for samples with mean grains sizes of 5-80 nm and bulk densities on the order of 95% of theoretical density are increased 2--5 times over that measured in pure, annealed samples of the same composition with micrometer grain sizes. Ductility in the nanocrystalline Cu has e… more

Date: December 1, 1990

Creator: Nieman, G. W.; Weertman, J. R. (Northwestern Univ., Evanston, IL (USA). Dept. of Materials Science and Engineering) & Siegel, R. W. (Argonne National Lab., IL (USA))

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Correlations between surface structure and catalytic activity/selectivity

Work continued on the correlations of catalytic activity of metals and surface structure. Work is described in the following areas: CO oxidation on a Cu/Rh(100) Bimetallic catalysts; electronic properties of bimetallic surfaces; and reflection absorption spectroscopy of bimetallic surfaces. 5 figs. (CBS)

Date: November 1990

Creator: Goodman, D. W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Probe molecule studies: Active species in alcohol synthesis

The goal of this research is to develop a better understanding of the mechanisms of formation of alcohols and other oxygenates from syngas over supported catalysts. Probe molecules will be added in situ during the reaction to help delineate reaction pathways and identify reaction intermediate species. The key of our study is to investigate how the species generated by these probe molecules interact with surface species present during oxygenate formation. A reaction and analysis system capable o… more

Date: September 1, 1991

Creator: Blackmond, D.G. & Wender, I.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Tabulation of thermodynamic data for chemical reactions involving 58 elements common to radioactive waste package systems

The rate of release and migration of radionuclides from a nuclear waste repository to the biosphere is dependent on chemical interactions between groundwater, the geologic host rock, and the radioactive waste package. For the purpose of this report, the waste package includes the wasteform, canister, overpack, and repository backfill. Chemical processes of interest include sorption (ion exchange), dissolution, complexation, and precipitation. Thermochemical data for complexation and precipitati… more

Date: August 1, 1980

Creator: Benson, L. V. & Teague, L. S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Chemical interactions in multimetal/zeolite catalysts

Research is proposed on two groups of zeolite based catalysts that contain two transition elements. In one group both metals are fully reduced, in the other group one element is left as a positive ion; it can act as a chemical anchor'', or as a catalyst promoter for the reduced metal. The objective is to explore the potential of such materials for designing superior catalysts for synthesis and conversion of hydrocarbons and other energy carriers. ENDOR, EXAFS, CO-FTIR and TPD will be used to id… more

Date: December 21, 1992

Creator: Sachtler, W.M.H.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Catalyst and process development for the H/sub 2/ preparation from future fuel cell feedstocks. Quarterly progress report, January 1-March 31, 1979

Phase I of this contract, which involved preliminary catalyst and process evaluations, has been completed with a decision to pursue an autothermal type reforming process in which the reactants, steam and oil, are preheated to reacting temperature by partial oxidation of the reactants over a monolithic catalyst upstream of the high temperature steam reformer. Five commercial steam reforming catalysts were evaluated in short tests to indicate initial aging. Methane leakage in the range of 2.4 to … more

Date: April 1, 1979

Creator: Yarrington, R M; Feins, I R; Hwang, H S & Mayer, C P

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Hydrogen isotopic exchange over palladium metal

We have recently developed the laser-Raman technique as a means of unambiguously measuring the partial pressures of all possible hydrogen isotopes in the gas phase. Using this technique we have investigated the hydrogen-deuterium exchange in a number of metals. This report presents detailed data for isotopic exchange in the palladium hydride system over the temperature range 26{degree}C to -100{degree}C at a pressure of 7 atm. First order kinetic rate constants and activation energies are summa… more

Date: January 1, 1990

Creator: Carstens, D.H.W. & Encinias, P.D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Electron yield XAFS study of evaporated Co/Pd multilayers with various thickness ratios of Co to Pd sublayers: Simulations of the Co K-edge XAFS and fourier transforms

Electron-yield XAFS measurements using the NSLS were made on e-beam evaporated Co/Pd multilayers with various sublayer thicknesses and different thickness ratios of Co to Pd sublayers. The Co K-edge and the Pd K-edge XAFS data were obtained for the Co/Pd multilayers with sublayer thicknesses of 3[Angstrom]/ 4[Angstrom], 15[Angstrom]/4[Angstrom], 3[Angstrom]/15[Angstrom], 2.1[Angstrom]/13.5[Angstrom], and 2.2[Angstrom]/4.5[Angstrom]. Fourier transforms of Co K XAFS for most samples show a splitt… more

Date: January 1, 1992

Creator: Choi, M. (Catholic Univ. Medical Coll., Seoul (Korea, Republic of). Dept. of Physics); Joo, J. H. (Korea Inst. of Science and Technology, Seoul (Korea, Republic of). Materials Design Lab.); Kim, S. K.; Kang, J. S.; Lee, Y. P. (Research Inst. of Industrial Science Technology, Pohang (Korea, Republic of)); Shin, S. C. (Korea Advanced Inst. of Science and Technology, Seoul (Korea, Republic of)) et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Systematic preparation of selective heterogeneous catalysts

The Single Turnover (STO) procedure, involving pulses of hydrogen and 1-butene, was developed for studying the types of active sites present on supported metal catalysts. The STO procedure was used to study direct saturated sites and other topics. Frontier molecular orbital studies were also made.

Date: November 7, 1991

Creator: Augustine, R.L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Use of metal hydrous titanium oxide catalysts to enhance coal tar yield via hydropyrolysis

Catalytic hydropyrolysis experiments performed in this project on several US and UK coals have established that tar yields in excess of 70% (daf basis) and conversions (100%-char) in excess of 80% can be achieved from bituminous coals containing 80--84% dmmf carbon using hydrous titanium oxide (HTO) catalysts with low concentrations of active metals. Total conversion approaches the reactive maceral contents for these coals. Previously performed two-stage catalytic hydropyrolysis experiments hav… more

Date: January 1, 1990

Creator: Klavetter, E.A.; Stephens, H.P. & Dosch, R.G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Evolution of tritium from deuterided palladium subject to high electrical currents

An increase in the tritium level was detected in deuterium when various configurations of palladium foil or powder and silicon wafers or powder were subject to a high pulsed current. The deuterium, at one atmosphere pressure, and was circulated in a sealed loop containing the cell and an ionization chamber to measure the tritium increase as a function of time. Over 4800 hours of data, spanning 10 cells (including deuterium and hydrogen controls), were collected with this system. Average tritium… more

Date: January 1, 1992

Creator: Claytor, T.N.; Tuggle, D. G. & Taylor, S. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Diffraction studies of the thermal properties of nanocrystalline Pd and Cr

Quantitative X-ray and neutron diffraction measurements were made on nanocrystalline and coarse-grained samples of Pd and Cr. For both materials, Debye-Waller parameter comparisons over a temperature range of approximately 20-300 K indicate that the nanocrystalline materials have increased static displacements of atoms from their equilibrium sites compared to coarse-grained material. No grain-size-correlated differences in thermal vibrational amplitude, lattice parameter, or thermal expansion c… more

Date: September 1, 1992

Creator: Eastman, J. A.; Thompson, L. J. (Argonne National Lab., IL (United States)); Fitzsimmons, M. R.; Lawson, A. C. & Robinson, R. A. (Los Alamos National Lab., NM (United States))

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Disposal of tritium-exposed metal hydrides

A plan has been established for disposal of tritium-exposed metal hydrides used in Savannah River Site (SRS) tritium production or Materials Test Facility (MTF) R D operations. The recommended plan assumes that the first tritium-exposed metal hydrides will be disposed of after startup of the Solid Waste Disposal Facility (SWDF) Expansion Project in 1992, and thus the plan is consistent with the new disposal requiremkents that will be in effect for the SWDF Expansion Project. Process beds contai… more

Date: January 1, 1991

Creator: Nobile, A. & Motyka, T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Study of muonic atoms in the A = 40 to 70 and A = 100 to 130 mass regions (nuclear charge radii, isotope and isotone shifts) and in the Sm-Gd and W-Os-Pt transition regions (electric monopole and quadrupole moments). Progress report No. 5, December 1, 1979-October 15, 1980. [Dept. of Physics, Purdue Univ. , 12/1/79-10/15/80]

The muonic x-ray spectra of the stable Ru and Pd isotope have been measured, and the data have been analyzed in terms of the effective Barrett radii and in terms of isotope shifts. The effects of the neutron subshell closure on the ..delta..N = 2 isotopes shifts at N = 56 is much smaller in the Ru (Z = 44) isotopes as compared to the recently observed effect in the Mo (Z = 42) isotope shifts. This is the first time a pronounced difference in ..delta..N = 2 isotope shifts has been observed for d… more

Date: October 1, 1980

Creator: Steffen, R M

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Metallization of large silicon wafers. Quarterly technical report No. 1, August 26--December 31, 1977. [45 references]

A proposed metallization system for large area silicon solar cells with shallow junctions is outlined, and its desirable features are discussed. A baseline process sequence for the nickel palladium metallization system (NPMS) is delineated. This baseline process sequence is serving as the starting point from which process variations are being performed. The eventual goal is optimization of the NPMS process and determination of the control ranges for NPMS process variables. Initial studies of pa… more

Date: January 1, 1977

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Cost estimate for muddy water palladium production facility at Mound

An economic feasibility study was performed on the ''Muddy Water'' low-chlorine content palladium powder production process developed by Mound. The total capital investment and total operating costs (dollars per gram) were determined for production batch sizes of 1--10 kg in 1-kg increments. The report includes a brief description of the Muddy Water process, the process flow diagram, and material balances for the various production batch sizes. Two types of facilities were evaluated--one for pr… more

Date: November 30, 1988

Creator: McAdams, R.K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Applications of Heavy-Ion Rutherford Backscattering Spectrometry (HIRBS) to the analysis of contact structures on GaAs and Ge

The use of Heavy-Ion Rutherford Backscattering Spectrometry (HIRBS) for the analysis of layered structures on GaAs and Ge substrates has been studied. Direct comparisons of data obtained using both /sup 16/O and /sup 4/He projectiles for the characterization of contact structures have demonstrated the advantages of HIRBS for the study of substrates with increased atomic masses due to the improved mass resolution of the method for high Z materials. We present results obtained from a study of the… more

Date: September 1, 1984

Creator: Yu, K.M.; Jaklevic, J.M. & Haller, E.E.

Item Type: Article

Partner: UNT Libraries Government Documents Department