Calcium systems

ChemicalRecope . There are advantages and disadvantages to each of the base systems employed in sulfite pulping (see Table 4). Each has its own potential recovery systems except the calcium system, which is obsolete. Calcium-based Hquors can be burned, but scaling problems are severe, and conversion of the calcium sulfate to CaO is not economical. 

Phase Diagrams, Intermetallic Phases and Compounds 7.3.3.1.3. Calcium Systems. 

Much attention has been paid to the pectin-calcium system because of its application in the food industry as gelling agent. A large body of the litterature on this subject is devoted to the gel formation as function of calcium concentration, pH and temperature [1-8]. There were also some reports on the... 

S+2H2O. Absorption efficiency of SO2 attainable in a magnesium system is good, and removal efficiencies from 90 to 95% have been claimed without difficulty at reasonable liquor recirculation and MgO feed rates. As with calcium systems, serious scaling occurs due 10 build-up of insoluble MgS03. 

Valyashko and Gode (414) have summarized the conditions necessary for formation of borates of sodium, potassium, ammonium, calcium, and magnesium. The effect of varying the cation is to alter the type of borate that is stable in contact with the aqueous solution. The stability ranges for solid phases in the sodium and calcium systems are shown in Table V. 

The detail studies of mechanochemical interaction in the course of activation of Ca(H2P04)i-H20+Ca0 mixtures showed that the degree of interaction is dependent on the amount of energy supplied to the reaction zone [37]. If the energy is less than 15 kJ/g, the phases of an aqueous phosphate-calcium system are... 

LM pectin/calcium systems Xanthan/carob and iota-carrageenan Xanthan/chromium Sodium alginates Gelatin. 

The calcium system is more complex than the cAMP system and contains a variety of mechanisms for transducing the Ca " " signal into changes in cellular function. It is also sensitive and responds to relatively small, transient changes in free Ca concentration. This sensitivity is desirable from a regulatory point of view, but it also... 

Cardoso et al. [13] also compared the dependency of the viscoelastic properties of mature OPE/calcium gels upon the polymer and calcium concentrations to those of the LMP. They showed that, for these variables, both pectin systems exhibited a power law dependence of the G. At pH 7, for the different concentrations of non-esterified carboxyl groups available in the pectin (o-GalA ), the PPE/calcium and citrus LMP/calcium systems exhibited similar dependencies on the calcium concentration (Fig. 8a), with a power law dependence of 2.9-3.3. Still, the gelling ability of OPE/calcium systems was more dependent on the polymer concentration than the citrus pectin. For the different calcium concentrations tested, the corresponding exponents of power law dependency were approximately 3.0 and 1.9 for OPE/calcium and citrus LMP/calcium systems, respectively (Fig. 8b). These results also confirm the lower capability of the pectic olive extracts to form, under similar ionic conditions, elastically effective junctions zones. 

Fig. 9 Temperature sweeps (1 Hz, 2°C/min) of OPE- and LMP-calcium systems ([GalA] = 10 g/L, [Ca " ] = 8.2 mmol/L (OPE) or [Ca ] = 4.4 mmol/L (LMP) at pH 7) afler maturation for 20 h at distinct temperatmes (open squares 5°C filled triangles 20°C filled circles 27.5°C and filled diamonds 35°C). Heating was performed from the respective matmation temperature to 70 or 80°C (adapted from [39])...

An alternative probe procedure is to use the trivalent lanthanides 42). Some lanthanide cations can replace calcium in a functional sense in biological systems. On the other hand, it is generally true that lanthanides inhibit calcium systems in a competitive way and they can be used therefore to probe the calcium sites. The lanthanides, 15 probes of slowly graded ionic size, represent a wonderful experimental tool for the study of biological selectivity and a chance to uncover fine control mechanisms. Almost every physical method can be used in the study of one or the other of these cations. 

Dob] Dobrovsky, L., Linzer, E., Unzeitigova, H., Analysis of the Fundamental Thermodynamic Data of Calcium Systems (in Czech), Shorn. Ved. Praci Vysok. Skoly Banske v Ostrava (Trans. Inst. Min. Metall. Ostrava Met Series), 1,1-20 (1988) (Calculation, Thermodyn., 31)... 

In the ternary alkaline earth octylsulphate-decanol-water system, the extension of the lamellar liquid crystalline phase towards the water comer increases in the order Mg " > Ca + > Ba (28 moles 0 per mole surfactant ion for magnesium against 18 moles for the calcium system and not quantified for the barium system). On the other hand, the minimum amount of water necessary to form the lamellar liquid crystalline phase in the calcium and magnesium systems is approximately the same, 8 moles per mole surfactant ion [4],... 

The solubility of oxide in the chloride melt increases by increasing the basicity of the system from the calcium system to the barium system. 

The EAR-6273 12 V battery based on the calcium chromate-calcium system was specifically designed to... 

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