1. An attempt has been made to locate the site of action of vitamin D(3) as it affects the translocation of calcium across the intestine. 2. Calcium appears to be pumped out of cells by a process dependent on energy from metabolism. 3. The effects of cold, inhibitors and vitamin D(3) on the translocation of calcium by everted sacs of intestine were studied and compared with results obtained in ...

This paper investigated thermal properties of natural thaumasite, such as phase composition and reaction mechanism decomposition using simultaneous TG/DTG-DSC in Ar Air medium up to 1673 K, coupled with masspectrometer for analysis evolving gases, in-situ powder X-ray diffraction measurements. The transitional solid phases, grown increasing temperature at thaumasite decomposition, are calcium h...

Background/ Objectives: Chemical Oxygen Demand (COD) is a widely used aggregate organic pollutant index in national discharge standards and one of the critical parameters for water quality assessment. The conventional COD determination by wet oxidative method encounters problem chloride interference samples with high content. dichromate reflux oxidizes 85-95% matter also 100% ions samples, with...

The rate of hydration influences many important physical properties of gypsum. Previous research examined the rate of gypsum hydration and related this to compressive strength and microstructure development using BET specific surface area analysis. The analysis of gypsum porosity in combination with BET surface area and rate of hydration remains to be done. In the present study, mesoporosity is...

Stabilisation of natural pavement materials to make road pavements is widespread in South Africa, using cement and lime as cementitious binders. The rapid speed of the cementing reaction limits these to plant based construction. Some hydraulic binders have the potential to be developed for Labour Intensive Construction stabilisation technology because their slow hydration reaction allows time t...

We present here a methodology, using holographic interferometry, enabling to measure the pure surface reaction rate constant of the dissolution of a mineral in water, unambiguously free from the influence of mass transport. We use that technique to access to this value for gypsum and we demonstrate that it was never measured before but could be deduced a posteriori from the literature results i...

Organic tofu using organic compatible coagulants of magnesium chloride and three polysaccharides including carrageenan, guar gum and gum Arabic were generated. For MgCl2 coagulated tofu, carrageenan significantly increased the hardness from 969.5 g to 1210.5 g whereas guar gum (0.6g) decreased the hardness to 505.5 g. Interestingly, gypsum and guar gum (0.6g) increased the yield of tofu signifi...

Amelioration of subsoil acidity using gypsum (CaS04.2Hz0) or lime (CaC03) was studied on sandy textured soils with low water holding capacity in a low rainfall environment. Field trials were established in 1989 at two sites on yellow sandplain soils to investigate whether different rates, sources and combinations of gypsum and lime application could be used to increase wheat and lupin yields. G...

The degree of III-CaSO4 to II-CaSO4 transition was estimated on wet specimens, 25 mm in diameter and 50 mm high, prepared from a gypsum-bonded investment for quick casting. After 30 min from mixing the specimens were heated in a 700 degrees C furnace until a specimen temperature of 200 degrees C to 700 degrees C was reached. The estimation was made by measuring mass changes of the specimens bef...