Pressure coefficient, relative

Proton magnetrogyric ratio Yp Relative pressure coefficient p... 

Proton magnetrogyric ratio TP Relative pressure coefficient r... 

Let us look at this approach using a concrete example, the relative pressure coefficient f, which is a measure of how steeply pressure rises when a body is heated at cmistant volume ... 

These relative solubility coefficients completely define the character of the partial and total pressure curves of binary mixtures. 

For both HA and its esters, the solubility coefficient, defined as the ratio between water concentration in the polymer and the water relative pressure (S = cw/relative pressure), did not strictly increase with concentration (Tables 1-4). For example, at low water concentrations the solubility coefficient decreased with concentration, whereas an opposite trend was shown at higher water concentrations. The solubility coefficient attained a minimum relative pressure of about 0.6 for all the materials tested. 

On the left-hand side of "Equation H is, of course, still an unknown function involving the relatively activity coefficient. Its value must, in general, depend on the composition, temperature and pressure of the system ... 

Andersen et al (Ref 6) obtained about the same pressure coefficient of D for NM as Brochet et al. However, theoretical considerations pre diet that this coefficient should decrease at higher ambient pressure. This predicted decrease was not observed. Indeed for NM and a solid aluminized expl, HBX, D increased with ambient pressure in essentially the same manner as it would increase with increasing initial density of the expl due to compression by the ambient pressure. Since the compressibility of liq expls and solid expls at near crystal density is relatively low at moderate ambient pressures, the rather small effect of ambient pressure on D is understandable... 

A global electrophilicity index of common benzylating and acylating agents has been established from MO calculations and it shows a quantitative linear correlation with the experimental substrate selectivity index from a series of benzylation and acylation reactions.21 The values of relative rate coefficients predicted from the index may be accurate to within 10%. The reaction of /-butyl chloride with anisole catalysed by /Moluenesulfonic acid in supercritical difluoromethane has been subject to kinetic analysis.22 The proportions of substitution at the ortho -position and disubstitution increase at lower pressures, attributed to the decrease in the hydrogen-bonding ability of the solvent. 

Membrane extraction encompasses a class of liquid-phase separations where the primary driving force for transport stems from the concentration difference between the feed and extractant liquids rather than a pressure gradient, as is the case with most of the other processes discussed above. A microporous membrane placed between the feed and the extractant liquids functions primarily as a phase separator. The degree of separation achievable is determined by the relative partition coefficients among individual solutes. This operationx is known as membrane solvent extraction. If a nonporous, permselective membrane is used instead, however, the selectivity of the membrane would be superimposed on the partitioning selectivity in this case the process may be referred to as perstraction. These process concepts are illustrated in Fig. 34. 

Fig. 17.12. Plots of relative absorption coefficients as a function of temperature for [Y(TMHD)3] vapour under a total pressure of 1.33 x 103Pa (10 Torr) (a) without oxygen...

In either case the relative distributions between the separable liquid and vapor phases are predicted from the pure component vapor pressures Pi°, liquid phase activity coefficients, y/s, and imperfection-pressure coefficients Oi s. Using these three quantities, the relative distribution is expressed as... 

The selectivity into butenes, defined by the ratio [butenes] / [butenes + butane] is controlled by two parameters. One is kinetic and measures the butene hydrogenation rate relative to the butene desorption rate. The other one is thermodynamic and depends on the relative adsorption coefficients of butadiene and butenes. It will fix the relative coverages in butadiene and butenes on the surface as a function of their relative pressures. In practice the second parameter, the thermodynamical one, turns out to be preponderant and then fixes the selectivity into butenes as a function of the conversion percentage. A better selectivity will be observed if butadiene is more strongly adsorbed than butene, or in other words, if the ratio between adsorption coefficients bdiene/bbutenes is high. 

The elTective potentials of Fig. 21 can be used to evaluate the barrier frequencies a>j using Eq. (2.27), which are then used to evaluate the encounter rate as a function of bath density using an appropriate formulation of the friction, as discussed in Section III. The results show that the onset of diffusion control will occur when the relative diffusion coefficient approaches (aqV T) / (8/cT/7i i) /, that is, at pressures of hundreds of atmospheres. In the case of ion-ion recombination the predicted rollover occurs at about 1 atm, in good agreement with exjjeriment. The theory of this section has... 

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