Specific pressure dependence

Miller W H 1988 Effect of fluctuations in state-specific unimolecular rate constants on the pressure dependence of the average unimolecular reaction rated. Phys. Chem. 92 4261-3... 

Song K and Hase W L 1998 Role of state specificity in the temperature- and pressure-dependent unimolecular rate constants for H02->H+02 dissociation J. Phys. Chem. A 102 1292-6... 

Experimental studies show that the ozone concentration iacreases with specific energy (eV/O2) before reaching a steady state. The steady-state ozone concentration varies iaversely with temperature but directiy with pressure, reaching a maximum at about 101.3 kPa (1 atm). Above atmospheric pressure the steady-state ozone concentration decreases with pressure, apparentiy due to the pressure dependence of the rate constant ratio for the... 

Equivalent hydrostatic pressure Pressure dependence of Curie temperature Change in compressibility Change in specific heat Change in thermal expansion... 

Compressibility and pressure dependence of Curie temperature are directly measured changes in specific heat and thermal expansion are calculated from the Ehrenfest relation. 

Ideally, separators would present no resistance to ion transport. In practice, some resistance must be tolerated. Still, the resistance of the separator is usually insignificant relative to the transport limitations in the electrodes. Separator permeability is typically characterized by air permeability. The Gurley number expresses the time required for a specific amount of air to pass through a specific area of separator under a specific pressure (e.g., 10 mL through 1 in2 (6.45 cm2) at 2.3 cm Hg). This measurement depends on porosity, pore size, thickness, and tortuosity according to Eq. (1) [17] ... 

The relevance of methods in this section to the measurement of specific surface depends on certain relationships that are assumed to hold between the rate of fluid flow, the pressure head,... 

During ongoing therapy with the antiarrhythmic dragp, the nurse takes the patient s blood pressure apical and radial pulses, and respiratory rate at periodic intervals, usually every 1 to 4 hours. Specific intervals depend on... 

Measurements of filtration rates should be repeated at different pressures or different vacuum levels. This gives information on the influence of pressure on the specific cake resistance. The specific resistance of cakes that are difficult to filter is often pressure-dependent. Thus, use of excessive pressure can result in blocking of the cake, causing filtration to stop. In the case of compressible cakes, information is needed over the whole range of pressures being considered for industrial filters since extrapolation of compressibility beyond the experimentally covered region is always risky. The larger the scale of an experimental filter, the less risky predictions based on the experimental data. 

The simplicity and accuracy of such models for the hydration of small molecule solutes has been surprising, as well as extensively scrutinized (Pratt, 2002). In the context of biophysical applications, these models can be viewed as providing a basis for considering specific physical mechanisms that contribute to hydrophobicity in more complex systems. For example, a natural explanation of entropy convergence in the temperature dependence of hydrophobic hydration and the heat denaturation of proteins emerges from this model (Garde et al., 1996), as well as a mechanistic description of the pressure dependence of hydrophobic... 

It should be recognized that the operation of a filter is an unsteady cyclic process. As the cake builds up and its resistance increases with time, either the flow rate (Q) will drop or the pressure drop (AP) will increase with time. The specific behavior depends on how the filter is operated, as follows. 

What this comparison indicates is that as a first approximation, the terms A and B in equation (45) are not strongly dependent upon temperature and concentration. The pressure dependence of K for electrolyte solutions can be thus estimated from the properties of pure water. Since K = 1/B , the reciprocal of the 1 atm compressibility, it thus becomes possible to make reasonable estimates of vp from 1 atm specific volume data (v°) and compressibility data (B ). 

Once a particular class of unit has been decided upon, the choice of a specific unit depends on initial and operating costs, the space available, the type and size of the product, the characteristics of the feed liquor, the need for corrosion resistance and so on. Particular attention must be paid to liquor mixing zones since the circulation loop includes many regions where flow streams of different temperature and composition mix. These are all points at which temporary high supersaturations may occur causing heavy nucleation and hence encrustation, poor performance and operating instabilities. As Toussaint and Donders(72) stresses, it is essential that the compositions and enthalpies of mixer streams are always such that, at equilibrium, only one phase exists under the local conditions of temperature and pressure. 

At ordinary pressure all the ionizable groups have their specific pK values and are present in ionized states according to these values. When pressure increases, we can expect all pK values to change, whereby the overall ionized state of the protein is changed. The whole hydration sheet may also be changed around the protein and conformational rearrangements may occur. This fact indicates that the volume of a protein may be very pressure-dependent. 

Interest in the pressure dependence of structural relaxation in fluids has been stimulated by recent applications [175, 176] of a simple pressure analogue of the VFTH equation for the relaxation time x at a constant pressure P to the analysis of experimental data at variable pressures. Specifically, x(P) for both polymer and small molecule fluids has been found to extrapolate to infinity at a critical pressure Pg, and this divergence takes the form of an essential singularity,... 

Here the pre-exponential factor At is the product of a temperature-dependent constant (ksT/h) = 2 X 10 °Ts where ke and h are the Boltzmann and Planck constants, and a solvent-specific coefficient that relates to both the solvent viscosity and to its orientational relaxation rate. This coefficient may be near unity for very mobile solvent molecules but may be considerably less than unity for viscous or orientationally hindered highly stractured solvents. The exponential factor involves the activation Gibbs energy that describes the height of the barrier to the formation of the activated complex from the reactants. It also describes temperature and pressure dependencies of the reaction rate. It is assumed that the activated complex is in equilibrium with the reactants, but that its change to form the products is rapid and independent of its environment in the solution (de Sainte Claire et al., 1997). 

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