Calcium fundamental properties

We have reported only the results of the last investigation of fundamental properties of this process. But there are many problems remaining unsolved such as growing mechanism of calcium phosphate, the reason of difference in phosphate removal efficiency between application to wastewater and tap water, and also how contaminants include into growing calcium phosphate. 

Gadolinium ions are highly toxic in their hydrated form [Gd(H20)g] +. In vivo, Gd + ions compete with calcium ions and block the reticuloendothelial system. To avoid this toxicity, gadolinium is complexed with an organic thermodynamically stable matrix, (see Lanthanide Complexes with Multidentate Ligands, Organometallic Chemistry Fundamental Properties, Lanthanides Coordination Chemistry) In addition, ligands that allow coordination sites for one (or more) water molecule(s) ate preferred since they increase... 

Calcium phosphates have a mmrber of fundamental properties which make them ideal for solid dosage formulations with a wide range of actives. Such properties include white color, stability, insolubility, no case hardening, good action with disintegrants, compatable with a wide range of active ingredients, and a source of calcium and phosphorus. 

The most important property of the dissolved solids in fresh waters is whether or not they are such as to lead to the deposition of a protective film on the steel that will impede rusting. This is determined mainly by the amount of carbon dioxide dissolved in the water, so that the equilibrium between calcium carbonate, calcium bicarbonate and carbon dioxide, which has been studied by Tillmans and Heublein and others, is of fundamental significance. Since hard waters are more likely to deposit a protective calcareous scale than soft waters, they tend as a class to be less aggressive than these indeed, soft waters can often be rendered less corrosive by the simple expedient of treating them with lime (Section 2.3). 

Nicol, S. K. Clarke, A. J. 1969. Some electrochemical properties of the calcium hydrozyapatite/ solution interface. In Fearnhead, R. W. Stack, M. V. (eds) Tooth Enamel II Its Composition, Properties, and Fundamental Structure. John Wright Sons, Bristol, UK, 179-186. 

Casein may be coagulated and recovered as rennet casein by treatment of milk with selected proteinases (rennets). However, one of the caseins, K-casein, is hydrolysed during renneting and therefore the properties of rennet casein differ fundamentally from those of acid casein. Rennet casein, which contains the colloidal calcium phosphate of milk, is insoluble in water at pH 7 but can be dissolved by adding calcium sequestering agents, usually citrates or polyphosphates. It has desirable functional properties for certain food applications, e.g. in the production of cheese analogues. 

Concrete made with calcium aluminate cement at a properly low w/c ratio is highly resistant to sulphate solutions, sea water or dilute acid solutions with pH > 4, including natural waters in which CO2 is the only significant solute. Resistance may extend to pH 3 if the salt formed is of sufficiently low solubility. Midgley (M96) showed that, for fully converted material exposed to a sulphate ground water for 18 years, penetration with formation of a substituted ettringite was limited to a depth of 5 mm. These properties are consistent with Lea s (L6) view that the resistance is due to the formation of a protective coating of alumina gel, coupled with the absence of CH. No fundamental studies, e.g. on microstructural effects, appear to have been reported. 

Abstract This chapter focuses on dental biomaterials designed for permanent placement in the mouth. The development of flowahle polymer-ceramic composites is traced and their rheological properties, such as pseudoplasticity and thixotropy, discussed. Also considered are some materials that are being developed for root canal therapy, including calcium phosphate cements. There is vast scope for research into materials development, clinical applications and fundamental mechanisms. 

Calcium plays a fundamental role in water oxidation ((1) for a review). The depletion of one Ca + ion results In the loss of oxygen evolution (2). The enzyme is blocked at the S3 to Sq step (3). the step at which O2 is released and probably also the step at which water is oxidized. A fraction of centres is incapable of Mn oxidation when Ca " " Is depleted. We suggested that these centres represent depletion of Ca + in centres In the SQ-state (3.4). We also proposed that the Ca binding properties were S-state dependent (3). Experimental evidence for this was obtained from observations that Ca + depletion procedures were much more efficient In certain S-states (S3>So S2>S ) (4). 

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