We previously showed that carcinogenic nickel, arsenic, and chromium(VI) compounds induced anchorage independence (AI) in diploid human fibroblastic cells (HFC) derived from foreskins (K. A. Biedermann and J. R. Landolph, Cancer Res., 47: 3815-3823, 1987). To elucidate the role of the valence state of chromium and solubility of chromium compounds in inducing AI, we studied the ability of solubl...

We investigate anisotropical and geometrical aspects of hexagonal structures of Silicon Carbide and propose a direction dependent interpolation method for oxidation growth rates. We compute threedimensional oxidation rates and perform one-, two-, and three-dimensional simulations for 4Hand 6H-Silicon Carbide thermal oxidation. The rates of oxidation are computed according to the four known grow...

Using X-ray diffraction, scanning and transmission electron microscopy, the microstructure of a new low-activation chromium-manganese austenitic steel with high content manganese strong carbide-forming elements is studied. Its structure, dislocation character particle composition are detailed. The processes taking place in under cold-rolling deformation described. It shown that mechanical prope...

Chromium supplements are thought to be the second most commonly taken nutritional supplement, used by an estimated 10 million Americans (1). Chromium is an essential element in humans, and deficiency is associated with the development of diabetes, which was first noted in patients receiving long-term parenteral nutrition before the advent of routine chromium supplementation (2,3). In these pati...

This study presents a failure analysis in two reformer tubes used for hydrogen production petrochemical industry. These (Tube A and Tube B) were made by the centrifugal casting of HP-Nb alloy such way that one contained titanium as micro-element, other was free from its chemical composition. Although subjected to similar creep conditions, failed after only 46,000 h operation against design life...

The primary carbide in high carbon chromium bearing steels, which arises from solute segregation during non-equilibrium solidification, is one of the key factors affecting mechanical properties and performance related components. In this work, effects forming element diffusion, austenite grain size, cooling rate on precipitation solidification an Fe–C binary alloy were studied by phase-field me...

The development of NbC-containing martensitic stainless steels has made it possible to unite the properties high corrosion resistance and wear resistance. If NbC is used as a hard phase instead chromium carbide, abrasive increased due greater hardness NbC. solubility in low. For this reason, fully available form passive surface layer increase In steel melt, niobium leads formation primary NbC, ...

In this work, the evolution of MC-type Nb-rich primary carbides in a 35Ni-25Cr-Nb-type refractory alloy, commonly known as HP40-Nb, and its transformation into Ni-Nb silicide G-phase (Ni16Nb6Si7), has been studied. For purpose, experimental technique scanning electron microscopy was used together with X-ray microanalysis to detect changes chemical composition niobium carbide over time at given ...

Chromium is a naturally occurring, toxic heavy metal used in many industrial processes. The U.S. Department of Labor's Occupational Safety and Health Administration has established specific limits for occupational exposure levels of chromium and guidelines for medical surveillance of individuals who have been exposed to chromium. The author presents a case in which a 54-year-old man who had bee...

This study evaluated the toxicity of hexavalent and trivalent compounds of chromium to the pacu, Piaractus mesopotamicus, in acute exposures of 96 h through mortality and histopathological responses. Hexavalent potassium dichromate was more toxic than trivalent compounds of chromium chloride, chromium oxide and chromium carbochelate. Sufficient mortalities occurred only with potassium dichromat...