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Classical solution model

So far two models have been employed to rationalize the solvation process the classical solution model, either the mole-fraction scale or any other concentration scale, and the Flory-Huggins model. The question is where to use which theoretical model to interpret the results of partitioning experiments, in which solute molecules distribute between two phases, a and ft. If the two phases are at equilibrium at the same temperature and the same pressure, /z = /xf. After rearrangement and applying Eq. (11-8), we can write... [Pg.286]

Although Eq. (6-18) can be used to eliminate the stress components from the general microscopic equations of motion, a solution for the turbulent flow field still cannot be obtained unless some information about the spatial dependence and structure of the eddy velocities or turbulent (Reynolds) stresses is known. A classical (simplified) model for the turbulent stresses, attributed to Prandtl, is outlined in the following subsection. [Pg.157]

The classical royalty model has long been the norm, and is still well accepted for the manufacture of fine chemicals or commodities where the production costs are a very significant part of the final price of the product. However, our experience is that this model is not well accepted in the Life Science Industry and often presents a real hurdle for the application of proprietary technology for the production of new chemical entities. The all-inclusive model takes care of these concerns, and allows the customer to compare competing solutions on the basis of actual costs as well as of their potential for improvement. The same is true for volume-independent payments, and for both methods all process improvements totally benefit the customer s bottom line and are not reduced by increasing royalty fees. [Pg.1317]

Part 1 Control of Chemical Processes. Some common problems in chemical processes are presented and either classical solutions or physical interpretation of controllers are discussed. Thus, the first chapter includes modeling and local control whereas the second chapter is focussed on nonlinear control design from heat balance on chemical reactors. The three first chapters deal with regulation problems while the last one is devoted to a tracking one. [Pg.326]

We adopt the following simple picture. Initially, we assume that steps are far enough apart that the effects of step repulsions can be ignored. The relevant physics for evaporation involves the detachment of adatoms from step edges, their surface diffusion on the adjacent terraces, and their eventual evaporation. This is quite well described by a generalization of the classical BCF model "- which considers solutions to the adatom diffusion equation with boundary conditions at the step edges. [Pg.209]

It appears that a permanent solution to the world energy problem, dramatic reduction of biospheric hydrocarbon combustion pollution, and eliminating the need for nuclear power plants (whose nuclear component is used only as a heater) could be readily accomplished by the scientific community [18]. However, to solve the energy problem, we must (1) update the century-old false notions in electrodynamic theory of how an electrical circuit is powered and (2) correct the classical electrodynamics model for numerous foundations flaws. [Pg.643]

Interestingly, there have been repeated attempts to view such gradual structural changes due to chemical equilibria as phase transitions as well [262]. Instructive examples for such an analysis are living polymers — for example, in demixing solutions of polymers [263] and in sulfur [264], where the reversible polymerization process has been treated as a second-order phase transition. The experimental evidence for such an interpretation is, however, at best weak [265], and classical association models [266] describe the thermodynamic properties equally well. [Pg.42]

On-site production is one such opportunity. It has been a strong driver of growth for several years and will continue to be so in the near future. On-site production is a clear departure from the classic business model of a gases player. Instead of merely supplying gas, the gases company supplies a solution it not only develops an optimum supply concept for an industrial customer, but also builds, installs, operates, and maintains the on-site gas supply systems. [Pg.146]

We now present the solution of the hyperbolic model defined by Eqs. (52) and (53)-(54) and compare the solution to that of the classical parabolic model with Danckwerts boundary conditions. We use the axial length and convective time scales to non-dimensionalize the variables and write the hyperbolic model in the following form ... [Pg.227]

All these findings may point to limitations of the classical Frumkin model for correction of the double-layer influence on electrode kinetics in nonaqueous solvents, although it works well in aqueous solution. In the present author s opinion these rather surprising results may follow from some kind of compensation effects. For instance, ion-pair formation in these solutions by decreasing the effective charge of the reactant could reduce the double-layer effect. [Pg.256]

Concentration polarization Concentration polarization is important for membrane operation and modeling. It represents increased concentrations of rejected solutes near the membrane surface. The concentration-polarization layer is described with the classic film model [19]. [Pg.1105]

In this study we restrict our consideration by a class of ionic liquids that can be properly described based on the classical multicomponent models of charged and neutral particles. The simplest nontrivial example is a binary mixture of positive and negative particles disposed in a medium with dielectric constant e that is widely used for the description of molten salts [4-6], More complicated cases can be related to ionic solutions being neutral multicomponent systems formed by a solute of positive and negative ions immersed in a neutral solvent. This kind of systems widely varies in complexity [7], ranging from electrolyte solutions where cations and anions have a comparable size and charge, to highly asymmetric macromolecular ionic liquids in which macroions (polymers, micelles, proteins, etc) and microscopic counterions coexist. Thus, the importance of this system in many theoretical and applied fields is out of any doubt. [Pg.110]

In this section we have studied the cascaded quadratic processes with an input two-mode coherent state in order to characterize the quantum phase shift. We have assumed the steady-state fields and illustrated this situation by the Deutsch-Garrison technique. To fit in the framework of such a technique, we perform a linearization around a classical solution. Further we have adopted the traditional approach to the propagation. We have determined a -dependent unitary progression operator of the two-mode system in the Schrbdinger picture by direct integration. We have compared the results in the large-mismatch limit with a model of an ideal Kerr-like medium, whose properties are effectively those of the cascaded quadratic nonlinearities. [Pg.593]

Solutions of Schrodinger s wave equation give the allowed energy levels and the corresponding wavefunctions. By analogy with the orbits of electrons in the classical planetary model (see Topic AT), wavefunctions for atoms are known as atomic orbitals. Exact solutions of Schrodinger s equation can be obtained only for one-electron atoms and ions, but the atomic orbitals that result from these solutions provide pictures of the behavior of electrons that can be extended to many-electron atoms and molecules (see Topics A3 and C4-C7). [Pg.15]


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