Zinc and zirconium were selected as the alloying elements in biodegradable magnesium alloys, considering their strengthening effect and good biocompatibility. The degradation rate, hydrogen evolution, ion release, surface layer and in vitro cytotoxicity of two Mg-Zn-Zr alloys, i.e. ZK30 and ZK60, and a WE-type alloy (Mg-Y-RE-Zr) were investigated by means of long-term static immersion testing i...

Since luting cement is used for fixing cast restorations to their abutments, the cement surface at the junction between cast and tooth is exposed to oral environment. The conventional cement so far used does not adhere to the tooth and is slightly soluble into saliva and gingival fluid1,2). Consequently, the microleakage and subsequent recurrent caries seem to develop at this junction. Recently...

A partial least-squares multivariate calibration method for the resolution of mixtures of metal ions from the spectra of the complexes produced in a flow injection (FI) system has been developed. The method has been applied to the simultaneous determination of Cull and Znii with 4-(4'-methyl-2'-thiazolylazo)-2-methylresorcinol. The reagent exhibits a high absorbance and its spectrum strongly ov...

ZnSe and other zinc chalcogenide semiconductor materials can be doped with divalent transition metal ions to create a mid-IR laser gain medium with active function in the wavelength range 2 – 5 microns and potentially beyond using frequency conversion. As a step towards fiberized laser devices, we have manufactured ZnSe semiconductor fiber waveguides with low (less than 1dB/cm at 1550nm) optica...

Hexavalent chromium [Cr(VI)] and ozone are produced in many arc-welding processes. Cr(VI) is formed when welding with chromium-containing alloys and is a suspected carcinogen. Ozone is formed by the action of ultraviolet light from the arc on oxygen and can cause severe irritation to the eyes and mucous membranes. Previous work has demonstrated that reduction of sodium and potassium in manual m...

Manganese minerals are widely distributed throughout the globe. The most important industrial uses of Mn are in the manufacture of steel, non-ferrous alloys, carbon-zinc batteries and some chemical reagents. Microbial recovery of manganese from low grade manganese ores using bioleaching was investigated in this paper. A bacterial strain, Staphylococcus epidermidis (MTCC-435) was collected from ...

Arsenic is present in all copper, lead, and zinc sulfide ores and is carried along with those metals in the mining, milling and concentrating process. Separation, final concentration and refining of by-product arsenic as the trioxide is achieved at smelters. Arsenic is the essential consistent element of many compounds important and widely used in agriculture and wood preservation. Lesser amoun...

Proton induced X-ray emission spectroscopy (PIXE) has been used to determine the intensity of metals from crowns in human teeth. In order to measure elements distribution across the tooth section, proton beam (3 MeV) has been collimeted to provide a spatial resolution of 300 microns. The samples were selected according to the time of insertion of crowns and the kind of alloys they were made of....