Ternary amorphous W–xCr–yZr alloys containing 9−38 at % tungsten, 15−42 at % chromium and 39−73 at % zirconium were successfully prepared by direct current (DC) magnetron sputtering technique. The corrosion rates of all the examined sputter−deposited W–xCr–yZr alloys were in the range of 1 × 10−3 mm/y or lower which are nearly one order of magnitude lower than those of the sputter−deposited tun...

We investigated the wear characteristics and clinical performance of four different total hip joint articulations in 114 patients. Wear and migration was measured by roentgenstereophotogrammetric analysis at five years or at the last follow-up. The mean annual wear was 0.11 mm for a stainless steel/Enduron articulation, 0.34 mm for stainless steel/Hylamer cup, 0.17 mm for zirconium oxide cerami...

Study of the implant-tissue interface is one of the fundamental issues in implantology, both odontologic and orthopedic. The characteristics of this interface will influence the success or failure of an implant. The aim of the present study was to evaluate histomorphometrically the capacity of different metals to osseointegrate employing laminar implants of zirconium, titanium, aluminum, and zi...

PURPOSE The present study compared changes in CIE L*a*b* color coordinates of substrates of different colors when covered with zirconium oxide discs (Procera) and with such discs if veneered with two shades of porcelain. MATERIAL AND METHODS Forty background substrates were fabricated and divided into four groups depending on the color of the substrates: white, black, gray, and tooth-colored ...

Raman spectroscopy has been used as a local probe to characterize the structural evolution of magnetron-sputtered decorative zirconium oxynitride ZrOxNy films which result from an increase of reactive gas flow in the deposition The lines shapes, the frequency position and widths of the Raman bands show a systematic change as a function of the reactive gas flow (a mixture of both oxygen and nitr...

The influence of zirconium on the grain refinement of Al 6063 alloy has been experimentally investigated. The microstructure and macrostructure of the refined alloy were investigated. The experimental results reveal that, the coarse dendrites in the microstructure of the alloy are effectively refined with the addition of zirconium to the melt prior to solidification. Grains of Al 6063 alloy can...

Porous zirconium alginate beads as a novel adsorbent were prepared for fluoride removal and characterized by SEM, FTIR, TG, EDX and XPS. The effect of solution pH, adsorbent dose, initial fluoride concentration, contact time, medium temperature and the coexisting ions on adsorption capacity of fluoride ion has been studied. The presence of HCO3 , SO4 2and PO4 3had a large negative impact on flu...

In the presence of large excesses of borohydride salts, gold monolayer protected-clusters can be grown to larger sizes simply by controlling the amount of reducing agent added to smaller clusters. In addition, gold monolayer clusters can be used as catalysts for reduction reactions by sodium borohydride; results suggest such catalysts have sterically constrained active sites.

A variety of phosphine oxides and sulfides can be efficiently converted directly to the corresponding phosphine boranes using oxalyl chloride followed by sodium borohydride. Optically active P-stereogenic phosphine oxides can be converted stereospecifically to phosphine boranes with inversion of configuration by treatment with Meerwein's salt followed by sodium borohydride.

The difficult to handle and store zinc borohydride, Zn(BH4)2, is stabilized by supporting it on polyvinylpyridine. This new mild, efficient, selective, and regenerable polymer supported borohydride reducing agent reduces a variety organic compounds such as, aldehydes, a-b-unsaturated carbonyl compounds, acid chlorides, epoxides, disu...