The essentiality and carcinogenicity of chromium depend on its chemical form. Oxidation state and solubility are particularly important in determining the biological effects of chromium compounds. For this reason, total chromium measurements are of little value in assessing its nutritional benefits or its toxicological hazards. Aqueous sodium carbonate-sodium hydroxide solutions have been succe...

Thermal infrared spectra of the martian surface indicate the presence of small concentrations (approximately 2 to 5 weight %) of carbonates, specifically dominated by magnesite (MgCO3). The carbonates are widely distributed in the martian dust, and there is no indication of a concentrated source. The presence of small concentrations of carbonate minerals in the surface dust and in martian meteo...

Measurements of electrochemical (EC) arsenite oxidation demonstrated thatthe arsenite oxidation current increased in the presence of carbonate while the potential of the onset of EC arsenite oxidation exhibited a strong shift toward less positive values. Examination of pH and total carbonate concentration effects on the EC arsenite oxidation parameters showed that they were affected solely by t...

abstract a study was conducted to evaluate the effect of incubation time, sewage sludge and clay content on the distribution of nickel and cadmium in different fractions of selected calcareous soils. to meet this purpose, an experiment with two different soils (4 and 30 percent caco3), two different textures (8 and 40 percent clay), two levels of nickel (0 and 100 mg.kg-1), two levels of cadmiu...

Analysis of 171 samples taken from the Neogene cohesive soils of the Southeastern edge of the Granada basin shows inverse correlation between carbonate content and dispersion index and swelling behaviour and direct correlations between carbonate content and shear strength. This paper shows that carbonate content and clay fraction activity have a great influence on the compaction characteristics...

Venus' canali, very long meandering channels, are inferred to be products of carbonate-sulfate magmas, comparable in some ways to carbonatite magmas on Earth. In 1994, [1] inferred that alkali-rich carbonate sulfate magmas were common and abundant just beneath Venus' surface. Current understanding of Venus suggests a cooler geotherm, so that carbonate-sulfate melt can be abundant only at pressu...

Near-surface reaction of CO2-bearing fluids with silicate minerals in peridotite and basalt forms solid carbonate minerals. Such processes form abundant veins and travertinedeposits, particularly in associationwith tectonically exposed mantle peridotite. This is important in the global carbon cycle, in weathering, and in understanding physical-chemical interaction during retrograde metamorphism...

Calcium carbonate and calcium-magnesium carbonate in the form of limestone, dolomite, marl, chalk, and Oyster shell are one of the most widely utilized non-metallic materials in the industrial world. The largest use of limestone or calcium carbonate is in the cement industry where it is used as a source of CaO and also in the concrete industry where it is used as the primary coarse aggregate. F...