Metal Hydride
Mostrando 13-22 de 22 artigos, teses e dissertações.
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13. Effect of partial substitution of nickel by tin, aluminum, manganese and palladium on the properties of LaNi5-type metal hydride alloys
Neste trabalho é feito um estudo do comportamento eletroquímico de eletrodos formados por pó de ligas de hidreto metálico do tipo AB5 com formulações LaNi(5-x)Zx, onde Z é um elemento metálico que substitui parcialmente o Ni, que inclui Sn, Al, Mn e Pd. No caso do Mn, algumas estruturas do tipo AB6 são também consideradas. A substituição de uma p
Journal of the Brazilian Chemical Society. Publicado em: 2003-08
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14. Baterias de níquel-hidreto metálico, uma alternativa para as baterias de níquel-cádmio
Nickel metal hydride (Ni-MH) batteries have emerged as an alternative for replacement of nickel-cadmium batteries, because of their more environmental compatibility and high energy capacity. In this article, we described the properties and applications for Ni-MH batteries, giving some emphasis on the metal-hydride electrode, including the description of comp
Química Nova. Publicado em: 2001-04
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15. Estudo das propriedades fisico-quimicas de catalisadores a base de CeO2 e Pd-CeO2 modificados por alcalinos I
The objective of this work was to study the physico-chemical and catalytic properties of ceO2 and Pd-CeO2 systems. Cerium oxides of high (C400) and low (C850) surface area and cerium oxides doped with sodium and barium compounds were used in this study. It was also analysed the influence of residual contaminants such as carbonates and nitrates on the propert
Publicado em: 1995
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16. Tecnicas eletricas para caracterização de eletrodos em celulas eletroquimicas
In this work we developed a series of electronic equiprnents which generate current or potential waveshapes appropriated for the study of the several aspects of the eletrochemical processes. Detailed circuits and a description of the apparatus are presented, associated with its corresponding technique: (a) current interruption technique for caracterizing ele
Publicado em: 1990
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17. Ressonancia paramagnetica eletronica do ion Gd3+, em hidretos metalicos do tipo fase de laves AB2Hx
The ternary intermetallic hydrides LaRu2Hx, CeRu2Hx, YRh2Hx and YNi2Hx, doped with Gd3+ ions, were investigated in function of both the hydrogen concentration, x, and temperature. A single EPR line was observed for Gd in the uncharged LaRu2 compound (x = O) in the normal state. The EPR parameters were found in good agreement with the previously published dat
Publicado em: 1988
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18. Alkyl-metal and aryl-metal bond chemistry in coordinately unsaturated polynuclear metal complexes
A new class of coordinately unsaturated polynuclear rhodium and iridium alkyl, benzyl, and aryl derivatives of the form [RM(1,5-cyclooctadiene)]x have been prepared by the reaction of the organolithium reagent with the cyclooctadienemetal chlorides at -78°C. The x-ray crystal structure of [μ-CH3Rh (1,5-cyclooctadiene)]2 is reported. The analogous iridium d
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19. Production of Volatile Derivatives of Metal(loid)s by Microflora Involved in Anaerobic Digestion of Sewage Sludge
Gases released from anaerobic wastewater treatment facilities contain considerable amounts of volatile methyl and hydride derivatives of metals and metalloids, such as arsine (AsH3), monomethylarsine, dimethylarsine, trimethylarsine, trimethylbismuth (TMBi), elemental mercury (Hg0), trimethylstibine, dimethyltellurium, and tetramethyltin. Most of these compo
American Society for Microbiology.
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20. A remarkably effective copper(II)-dipyridylphosphine catalyst system for the asymmetric hydrosilylation of ketones in air
The combination of catalytic amounts of optically active dipyridylphosphine and CuF2 along with hydride donor PhSiH3 generated in situ a remarkably reactive catalyst system (substrate-to-ligand molar ratio up to 100,000) for the highly enantioselective hydrosilylation of a broad spectrum of aryl alkyl ketones (up to 97% enantiomeric excess) in normal atmosph
National Academy of Sciences.
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21. Oxidative damage of DNA by chromium(V) complexes: relative importance of base versus sugar oxidation.
Chromium(V)-mediated oxidative damage of deoxy-ribonucleic acids was investigated at neutral pH in aqueous solution by utilizing bis(2-ethyl-2-hydroxy-butanato)oxochromate(V) (I) and bis(hydroxyethyl)-amino-tris(hydroxymethyl)methane)oxochromate(V) (II). Single-stranded and double-stranded (ds) calf thymus and human placenta DNA, as well as two oligomers, 5'
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22. A structure-based catalytic mechanism for the xanthine oxidase family of molybdenum enzymes.
The crystal structure of the xanthine oxidase-related molybdenum-iron protein aldehyde oxido-reductase from the sulfate reducing anaerobic Gram-negative bacterium Desulfovibrio gigas (Mop) was analyzed in its desulfo-, sulfo-, oxidized, reduced, and alcohol-bound forms at 1.8-A resolution. In the sulfo-form the molybdenum molybdopterin cytosine dinucleotide