The separation of hafnium from zirconium using tributyl phosphate offers interesting alternatives to present methods for making reactor-grade zirconium. Feed solution for the extraction step can be prepared from the reaction product of caustic and zircon sand. The purified zirconium can be converted into a variety of compounds, depending on the process chosen for reduction to the metal. It may ...

Titanium and zirconium were immersed in Hanks’ solution with and without calcium and phosphate ions, and the surfaces were characterized with X-ray photoelectron spectroscopy (XPS) to determine the mechanism of calcium phosphate formation on titanium in simulated body fluids and in a living body. In addition, they were cathodically polarized in the above solutions. As a result, neither calcium ...

The anisotropic field dependence of the Sommerfeld coefficient gamma has been measured down to B-->0 by combining specific heat and Hall probe magnetization measurements in MgB2 single crystals. We find that gamma(B,theta) is the sum of two contributions arising from the sigma and pi band, respectively. We show that gammasigma(B,theta)=B/Bc2(theta) where Bc2(theta)=Bc2ab/sqrt[sin2theta+Gamma2co...

Many materials that are usually found in the earth's crust contain small but measurable amount of naturally occurring radioactivity (NORM). Some particular ores contain natural radionuclide at levels much higher those usually present in earth's crust; and are also subject to radioisotope enrichment, during technological process, known as technologically enhanced natural radioactivity (TENORM). ...

Ceramic plates with dimensions of 90 × 40 7 mm and a density 3.41 g/cm3 were obtained by the method free SHS-compression. The resulting consist three phases: aluminum oxide, titanium diboride, mullite. have composite structure: matrix based on Al2O3 diboride particles distributed in it. Also, structure plates, whiskers monoboride thickness about 100 nm observed. results high-temperature tests r...

Zirconium oxy-salts were hydrolyzed to form positively charged polymer or cluster species in acidic solutions. The zirconium hydrolyzed polymer was found to react with a negatively charged polyelectrolyte, such as poly(vinyl sulfate), and to form a stoichiometric polyion complex. Thus, colloidal titration with poly(vinyl sulfate) was applied to measure the zirconium concentration in an acidic s...

o bjectives: providing reliable attachment between bracket base and zirconia surface is a prerequisite for exertion of orthodontic force. the purpose of the present study was to eval- uate the effect of four zirconium surface treatment methods on shear bond strength (sbs) of orthodontic brackets. mat erials and methods: one block of zirconium was trimmed into four zirconium sur- faces, which se...

In the present study, novel MRI compatible zirconium-ruthenium alloys with ultralow magnetic susceptibility were developed for biomedical and therapeutic devices under MRI diagnostics environments. The results demonstrated that alloying with ruthenium into pure zirconium would significantly increase the strength and hardness properties. The corrosion resistance of zirconium-ruthenium alloys inc...

BACKGROUND In vitro analysis has shown that oxidized zirconium on ultra-high molecular weight polyethylene has better wear properties than cobalt-chromium on ultra-high molecular weight polyethylene. The purpose of this study was to determine if oxidized zirconium femoral components performed better than cobalt-chromium in vivo and if the use of oxidized zirconium components had clinical advers...

Reaction of a zinc/zirconium heterobimetallic complex with 1,5-cyclooctadiene (1,5-COD) results in slow isomerization to 1,3-cyclooctadiene (1,3-COD), along with the formation of a new complex that includes a cyclooctyne ligand bridging two metal centers. While analogous magnesium/zirconium and aluminum/zirconium heterobimetallic complexes are competent for the catalytic isomerization of 1,5-CO...