CaCl, type

Oil/water interfacial tensions were measured for a number of heavy crude oils at temperatures up to 200°C using the spinning drop technique. The influences of spinning rate, surfactant type and concentration, NaCI and CaCI2 concentrations, and temperature were studied. The heavy oil type and pH (in the presence of surfactant) had little effect on interfacial tensions. Instead, interfacial tensions depended strongly on the surfactant type, temperature, and NaCI and CaCL concentrations. Low interfacial tensions (<0.1 mN/m) were difficult to achieve at elevated temperatures. 

Looking at the trends in atomic properties, we can see that K atom is bigger than Ca and consequently that Ca is smaller than K but bigger than Ca. Thus, the ionic radius for Ca can be approximated as in between that of K and Ca. Since KCl has an NaCI-type structure, we can safely assume that CaCl would have the same, so we are using cationic radii for coordination six (138 + 100)pm/2 = 119 pm. We have ... 

This study also showed that CaCl had a softening effect masked by the commonly seen firming action of Ca , Table I and Ref (19). When bean pods, cooked earlier In either CaCl solution or distilled water, were soaked In the same type of salt solutlon In order to create similar cooked pod salt concentrations the beans cooked In distilled water had significantly firmer texture. 

The three different organic types (IHSS HA FA, NOM) and the three NOM fractions (humic, fulvic and hydrophilic) were compared at the high calcium concentration of 2.5 mM CaCl 2. This smdy was undertaken in order to investigate if the different organics respond diff erendy to aggregation with calcium. 

Table 7.11 Rejection in the presence of different organic types for the TFC-SR membrane (0.5 mM CaCl, 1 mM NaHCO, 20 mM NaC/).

Table 7.24 Flux and deposit as a function of membrane type (0.5 mM CaCl 1 mM NaHCOj, 20 mM NaCl and 12.5 mgL DOC FA).

Table 7.30 Effect of organic type and concentration with TFC-S membrane (12.5 mgL DOC, 2.5 mM CaCl().

Table 7.31 Deposition andflux as a function of organic type (TFC-SR, 12.5 mgE DOC, 2.5 mM CaCl, pH 8, conductivity 2 mScnf).

Allow uptake to occur for the desired time period. In wild-type cells responses to chemoattractants have usually terminated by 60 s after the addition of chemoattractant see Note 15). At each desired time point terminate Ca entry by addition of 100 pL ice-cold H buffer containing 775 mM CaCl. ... 

Autoclaved physiological saline solution. Traditionally, Howard s Ringer solution is used (0.12M NaCl, 0.0015M CaCl, 0.005M KCl pH adjusted to 7.2 with very diluted HCl), but saline (0.123 M NaCl pH 7.0) or phosphate-buffered saline (PBS 0.01 M phosphate buffer, 0.0027M KCl, and 0.137M NaCl, pH 7.4) suffice. Note, when saline is quoted in the text, any of the three types of solutions can be used. Penicillin-streptomycin (Sigma) SOO-pl aliquots, store at -20°C. 

In many cases it is not only the reagents depletion that can be measured, but also the product appearance, as a function of the excitation laser. The latter type of spectrum is termed an action spectrum. Figure 24.9 shows the CaCl action spectrum from the laser-induced Ca - HCl intra-cluster reaction. The Ca HCl complex is prepared in a supersonic expansion and excited by a laser pulse (at a frequency close to the atomic resonance) to a repulsive electronic state. The dissociation into CaCl and H products can be characterized either by tuning the laser frequency and recording the subsequent action spectmm, or by using LIF detection. 

Preparation of uranium metal. As discussed previously, some nuclear power plant reactors such as the UNGG type have required in the past a nonenriched uranium metal as nuclear fuel. Hence, such reactors were the major consumer of pure uranium metal. Uranium metal can be prepared using several reduction processes. First, it can be obtained by direct reduction of uranium halides (e.g., uranium tetrafluoride) by molten alkali metals (e.g., Na, K) or alkali-earth metals (e.g.. Mg, Ca). For instance, in the Ames process, uranium tetrafluoride, UF, is directly reduced by molten calcium or magnesium at yoO C in a steel bomb. Another process consists in reducing uranium oxides with calcium, aluminum (i.e., thermite or aluminothermic process), or carbon. Third, the pure metal can also be recovered by molten-salt electrolysis of a fused bath made of a molten mixture of CaCl and NaCl, with a solute of KUFj or UF. However, like hafnium or zirconium, high-purity uranium can be prepared according to the Van Arkel-deBoer process, i.e., by the hot-wire process, which consists of thermal decomposition of uranium halides on a hot tungsten filament (similar in that way to chemical vapor deposition, CVD). 

So far we have discussed the colligative properties of nonelectrolyte solutions. Because electrolytes undergo dissociation when dissolved in water [W Section 4.1], we must consider them separately. Recall, for example, that when NaCl dissolves in water, it dissociates into Na Co ) and C aq). For every mole of NaCl dissolved, we get two moles of ions in solution. Similarly, when a formula unit of CaCL dissolves, we get three ions one Ca ion and two Cl ions. Thus, for every mole of CaCl2 dissolved, we get three moles of ions in solution. Colligative properties depend only on the number of dissolved particle.s—not on the type of particles. This means that a 0.1 m solution of NaCl will exhibit a freezing point depression twice that of a 0.1 m solution of a nonelectrolyte, such as sucrose. Similarly, we expect a 0.1 m solution of CaCL to depress the freezing point of water three times as much as a 0.1 m sucrose solution. To account for this effect, we introduce and define a quantity called the van t Hoff factor (i), which is given by... 

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