905 resultados para magnetism, Fe-Ti-O-phasesystem, Co-Ti-O-phasesystem
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Raulin, Jean (O.S.B.), 1443-1514. Itinerarium paradisi religiosissimi patris artium ac sacre pagine p[ro]fessoris Parisien[sis] diuiniq[ue] verbi declamatoris facundissimi magistri Ioannis Raulin ordinis Cluniace[nsis], co[m]plecte[n]s sermones de Penit
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Pie de imp. tomado del colofón
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Experimental diffusion data were critically assessed to develop the atomic mobility for the bcc phase of the Ti–Al–Fe system by using the DICTRA software. Good agreements were obtained from comprehensive comparisons made between the calculated and the experimental diffusion coefficients. The developed atomic mobility was then validated by well predicting the interdiffusion behavior observed from the diffusion-couple experiments in available literature.
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Identifying terrigenous sources in deep-sea sediments may reveal temporal trends in paleocirculation and the relative role of eolian, upwelled, and hemipelagic Fe sources to surface waters. Bulk elemental and isotopic geochemistry of deep-sea sediments recovered during Ocean Drilling Program Leg 177 in the southeastern Atlantic sector of the Southern Ocean reveal several important aspects of paleocirculation and terrigenous provenance. The sites studied span 43°-53°S and represent different oceanographic settings relative to regional hydrography and sediment type. Bulk sediment geochemistry indicates that terrigenous provenance varied over the past 600 k.y. Site 1089, the northernmost site, exhibits clear glacial-interglacial variability in provenance, while provenance appears to vary regardless of climate state at the more southerly sites (Site 1093 and 1094). Nd and Sr isotopes and Sm/Nd ratios of the terrigenous fraction indicate that study sites have geochemically distinguishable provenance. Nd and Sr isotopes further suggest that Sites 1089 and 1094 both contain detrital components that originated in South America over the past 30 k.y.; however, Site 1089 is also influenced by southern African sources and the strength of the Agulhas Current. The e-Nd data support a more hemipelagic source for the terrigenous material rather than an eolian source based on comparisons with Antarctic ice core data and known sea-ice extent.
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Edit16,
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The purpose of this study was to evaluate the incidence of corrosion and fretting in 48 retrieved titanium-6aluminum-4vanadium and/or cobalt-chromium-molybdenum modular total hip prosthesis with respect to alloy material microstructure and design parameters. The results revealed vastly different performance results for the wide array of microstructures examined. Severe corrosion/fretting was seen in 100% of as-cast, 24% of low carbon wrought, 9% of high carbon wrought and 5% of solution heat treated cobalt-chrome. Severe corrosion/fretting was observed in 60% of Ti-6Al-4V components. Design features which allow for fluid entry and stagnation, amplification of contact pressure and/or increased micromotion were also shown to play a role. 75% of prosthesis with high femoral head-trunnion offset exhibited poor performance compared to 15% with a low offset. Large femoral heads (>32mm) did not exhibit poor corrosion or fretting. Implantation time was not sufficient to cause poor performance; 54% of prosthesis with greater than 10 years in-vivo demonstrated none or mild corrosion/fretting.