Chromium occurs mostly in tri- and hexavalent states in the environment. Hexavalent chromium [Cr(VI)] compounds are extensively used in diverse industries, and trivalent chromium [Cr(III)] salts are used as micronutrients and dietary supplements. In the present work, we report that they both induce genetic mutations in yeast cells. They both also cause DNA damage in both yeast and Jurkat cells ...

For the years 1987-1990 160 individual samples of manual metal arc stainless steel (MMA/SS) welding fumes from the breathing zone of welders in four industrial plants were collected. Concentrations of soluble and insoluble chromium (Cr) III and Cr VI compounds as well as of some other welding fume elements (Fe, Mn, Ni, F) were determined. Concentration of welding fumes in the breathing zone ran...

The effect of chromium (VI) on the activity of dehydrogenases, urease, acid and alkaline phosphatases and the yield of lupine was assayed in a pot experiment. Chromium was applied as K2Cr2O7 in the amounts of 0, 10, 20, 30, 40, 50, 100 and 150 in mg · kg of soil. The tests were conducted on brown leached soil from slightly dusty clay sand of pH in 1 M KCl 5.80. Soil was inoculated with nitragin...

The effect of Ni and Cr additions on microstructure, lattice misfit, oxidation, creep properties are investigated for six W- Mo-free cobalt-based superalloys with compositions Co-xNi-5Al-yCr-3V–2Ti-1.5Nb-1.5Ta-0.08B (at.%), where x = 10, 20, or 30 y 4 8. In all alloys, the γ + γ′ microstructure is stable up to 1000 h upon aging at 850 °C. As increases from 10 at.%, area fraction 32 49% in three...

AIM There is little information considering the framework association between cast clasps and attachments. The aim of this study was to evaluate the retention strength of frameworks match circumferential clasps and extra resilient attachment cast in three different alloys (cobalt-chromium, nickel-chromium titanium and commercially pure titanium), using two undercut (0.25 and 0.75 mm) and consid...

In this study, finite element analysis was used to investigate the fatigue behavior of eight different hip stems. All of the prostheses investigated in the analysis are already being used in Turkish orthopaedic surgery. All stems were compared with each other in terms of fatigue, deformation and safety factors. Primary analysis was applied on three of the stems, which were tested experimentally...

A base aluminium-silicon alloy AlSi25Cu5Cr was used to investigate the possibility of alloying aluminium alloys with hard-to-melt elements. The elements Co, Cr and Mo were introduced into melt using metal powder from a hard-melting dental cobalt-chromium-molybdenum alloy. packed in foil studied at temperature 810º C. After mechanical stirring melt, it stood for 30 min. temperature, raised 850º ...

STATEMENT OF PROBLEM Cobalt-chromium (Co-Cr) alloys have been widely used for metal-ceramic fixed prostheses and can be fabricated using conventionally cast or new computer-aided technology. However, the effect of different manufacturing methods on the metal-ceramic bond strength needs further evaluation. PURPOSE The purpose of this in vitro study was to evaluate the metal-ceramic bond streng...