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...

First principles density functional theory calculations are carried out to investigate the scaling trends of band offsets at model silicon/zirconium silicate interfaces. Owing to the d character of zirconium silicate conduction bands, the band gap and band offset are shown to decrease as the zirconium concentration is increased. Since the valence band character of silicates remains unchanged re...

The syntheses of a series of tris(amidate) mono(amido) titanium and zirconium complexes are reported. The binding motif of the amidate ligand has been determined to depend on the size of the metal centre for these sterically demanding N,O-chelating ligands; the larger zirconium metal centre supports three κ(2)-(N,O) bound amidate ligands while the titanium analogue has one ligand bound in a κ(1...

An overview on the developments of zirconium phosphate (ZrP) and its organic derivatives in heterogeneous catalysis in recent years is reported in the present review. Two basic aspects have been emphasized: first, the catalytic properties of zirconium phosphates were discussed, with particular attention to the effect of surface acidity and hydrophobic/hydrophilic character, textural properties,...

We report results of simulations on the formation of simple zirconium iodide molecules. Previous work by Wimmer et al. [1] explored the relationship between iodine and a zirconium surface. We investigate the reaction schemes through atomistic simulations to better understand the nature of Zr-I interactions through isolated molecules. The computed energy values of varying Zr-I systems suggests a...

AIMS To report the appearances of zirconium dioxide and barium sulphate in interface membranes, synovium, and other tissues around joint prostheses. METHODS Histological sections from 23 specimens were reviewed by light microscopy and polarisation. Scanning electron microscopy and x ray microanalysis were performed on routinely processed paraffin wax sections. RESULTS Polyethylene, metals, ...

The mechanical properties and good biocompatibility of zirconium and some of its alloys make these materials good candidates for biomedical applications. The attractive in vivo performance of zirconium is mainly due to the presence of a protective oxide layer. In this preliminary study, the surface of pure zirconium modified by anodisation in acidic media at low potentials to enhance its barrie...