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...

SMMSS, K. Calcium and carbonate metabolism in the frcg (Rana temporia) during respiratory acidosis. Am. J. Physiol. 2 14(3) : 627634. 1968.-Frogs (R. temporaria) contain large deposits of calcium carbonate in the endolymphatic sacs of the inner ear. Methods are described for determining the quantities of calcium and phosphate lost from frogs made acidotic with carbon dioxide (5-200/o in oxygen)...

Introduction Rivers are one of the most important water resources and it is very important to study their water quality. Therefore, in this study, sampling was done from 15 permanent waterway stations of Pirbadush and Gashun of Qolyan River in Lorestan province, which are located in the path of oil shales.   Materials and Methods  Hydro-geochemical parameters were calculated by analyzing t...

The occurrence of pregnancy induced hypertension in low-income young nulliparous women is confirmed in different reports and increase the risk of preeclampsia. More knowledge on the role of nutrients especially calcium demonstrates its major role in regulating blood pressure. Sufficient intake of pregnancy can prevent pregnancy induced hypertension. This study was conducted to evaluate efficacy...

The effects of solid state synthesis process parameters (time and temperature) and primary calcium precursor on the amount of produced α-tricalcium phosphate (Ca3(PO4)2 or α -TCP) have been investigated. α-TCP was synthesized by firing of stoichiometric amount of calcium carbonate and monetite in first group and calcium carbonate and brushite in the second group, once at 1350°C for 3,6,8,16 h d...

In the present work the internal sulfate attack on pastes made from pure clinker phases was studied. Two binders were produced: (a) a binder with 2% C3A and 18% C4AF content; (b) a binder with 10% C3A and C4AF content each. Gypsum was used as the sulfate bearing compound, while calcium carbonate added to differentiate the binders produced. The phases formed were identified by XRD analysis. The ...

The authors previously published a theory of calculus formation that components of a calculus separated from colloidal body fluid are coagulated and solidified by electrostatic effect of electrolytes, bridging action of high molecular-weight organic substances, and kinetic energy supplied from the organism. In support of this theory, they could produce gallstone-like concre ments of calcium bil...