It is common for the components in a homogeneous metallic alloy to separate at its surface. This phenomenon is known as surface segregation. For example, under certain conditions, the surface layer of atoms in a Cu85Pd15 is pure copper, while the second layer of atoms is 50% copper. The bulk retains its 85/15 composition. A depth-profile characterizes the surface segregation by describing the a...

Objective: The aims of this study were to investigate the release of element from, and the biological response in vitro to, cobalt-chromium alloys and other base-metal alloys used for the fabrication of metal-ceramic restorations. Material and methods: Eighteen different alloys were investigated. Nine cobalt-chromium alloys, three nickel-chromium alloys, two cobalt-chromium-iron alloys, one pal...

This study explores the role of membrane phospholipid peroxidation in the copper alloy mediated contact killing of Bacillus subtilis, a spore-forming gram-positive bacterial species. We found that B. subtilis endospores exhibited significant resistance to copper alloy surface killing but vegetative cells were highly sensitive to copper surface exposure. Cell death and lipid peroxidation occurre...

The amount of twin formation of electroplated and thermally treated copper thin films was evaluated by electron back-scattering diffraction (EBSD) analysis. The result establishes the importance of twin formation in the analysis of stress-induced voiding, and indicates that with the inclusion of a copper alloy co-element, twin formation was significantly reduced relative to pure-copper. Further...

The purpose of this study was to determine the galvanic interaction between pure titanium, a CoCrMo alloy, as well as their galvanic interaction with a high copper and a conventional amalgam at different area ratios. Pure titanium, a CoCrMo alloy and two dental amalgams with different copper compositions were tested in this study in 0.9% NaCl environment of pH 7. Polarization curves were record...

Previously, high temperature properties of the silver-palladium-copper-gold alloy were investigated. In this study, the thermal expansion percentage and coefficient, and high temperature strengths of ADAS Type 3 gold alloy were investigated up to the liquidus temperature. Furthermore, microstructural and compositional changes in the solid/liquid dual phase were studied. The following conclusion...

In this study, CoCu alloy nanoparticles-incorporated carbon nanofibers are introduced as effective non precious electrocatalyst for methanol oxidation in alkaline medium. The introduced electrocatalyst has been synthesized by simple and effective process; electrospinning. Typically, calcination, in nitrogen atmosphere, of electrospun nanofibers composed of cobalt acetate, copper acetate and pol...

We report the draft genome sequence of Pseudomonas psychrotolerans strain L19, isolated from a European 50-cent copper alloy coin. Multiple genes potentially involved in copper resistance were identified; however, it is unknown if these copper ion resistance determinants contribute to prolonged survival of this strain on dry metallic copper.

ABSTRACT Infrared spectroscopy has been employed for a detailed characterization of ZrO2 and CeO2/ZrO2 supported nickel and copper/nickel catalysts to be utilized for methane decomposition. Adsorption of CO at 303 K was performed in order to determine the surface composition and accessible adsorption sites. Alloy formation occurred during reduction, as indicated by a red-shift of the vibrationa...