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Predicting behavior inside

The other one is to roughly predict the hydrodynamic behavior inside a J-type CCC device, in order to know the best combinations of some experimental conditions to obtain the highest retention of the stationary phase. For this purpose, the research worker may also use the theoretical settling velocity of a droplet of a lighter phase inside the heavier continuous liquid phase. It was demonstrated to be the better way of predicting the hydrodynamic behavior and, consequently, the best combination of experimental parameters for the highest retention of the stationary phase. [Pg.1481]

Computational fluid dynamics enables us to investigate the time-dependent behavior of what happens inside a reactor with spatial resolution from the micro to the reactor scale. That is to say, CFD in itself allows a multi-scale description of chemical reactors. To this end, for single-phase flow, the space resolution of the CFD model should go down to the scales of the smallest dissipative eddies (Kolmogorov scales) (Pope, 2000), which is inversely proportional to Re-3/4 and of the orders of magnitude of microns to millimeters for typical reactors. On such scales, the Navier-Stokes (NS) equations can be expected to apply directly to predict the hydrodynamics of well-defined system, resolving all the meso-scale structures. That is the merit of the so-called DNS. [Pg.10]

Here z = WqLR is identical to the EM parameter provided Wo = k-el. Z(D) behavior for inner starts is qualitatively similar for contact starts from the exponential reaction zone. The noncontact starts from the exponential reaction zone are also similar to the starts from inside the rectangular recombination zone. Only for starts outside this zone, Z(D) is a monotonically increasing function of the diffusion coefficient [Fig. 3.26(h)]. For thin layers (qL << 1) this dependence coincides with that predicted by the CA Eq. (3.209). This is a consequence of the artificially sharp borders of the rectangular recombination layer. Ions that are born outside do not react in principle unless diffusion delivers them into the reaction zone. [Pg.193]

Many of these approaches have been used in mixed potential models to predict the behavior of copper nuclear waste containers in a compacted clay environment (22), and to predict the corrosion rate of nuclear fuel inside these containers once they have failed and water allowed to contact the nuclear fuel (U02) wasteform (6). The container is lined with a carbon shell liner to give it mechanical integrity. Consequently, when the container floods with water on failure, two corrosion processes are possible, corrosion of the U02 wasteform (conservatively assumed to be unprotected by the Zircalloy cladding within which it is encapsulated) and corrosion of the carbon steel liner. The reaction scheme underlying... [Pg.230]

Without perfusive flow (to = 0) the equation reduces to the classical expression for HC ts as used in pressure-driven LC. Equation (9) predicts some of the expected behavior of systems in which a high pore flow is present. For nonsorbed compounds (k" and k equal to 0) the Cs term contains a factor (1 -to) in the numerator. This implies that peak broadening is not related to the flow velocity itself, but depends on the flow velocity difference between the pore and interstitial volume. For unretained compounds the Cs term vanishes with fully perfusive flow (to = 1). This result is as expected when the transport rate of a tracer inside the particles matches that outside the particles, there cannot be a contribution to peak broadening related to mass exchange. For retained solutes (k" 0), however, the velocity within the particles is still different from that between the particles, and consequently mass transfer effects will occur. [Pg.200]

TCM, say Jf. When goes to infinity, Jf is saturated to certain value. This property is directly related to the existence of tori inside the TCM (the dynamics with E < 0). Thanks to a large mass ratio H, He, Li+, Be +, and so on, in the collinear eZe configuration are probably hyperbolic. This hyperbolicty and the intermittency would reflect the behavior of the quantum defects of H, He, Li+, Be +, and so on. Nonhyperbolic systems are also predicted by our finding, that is e-e-e, p-p-p, and Hj. [Pg.333]

There is an inherent coupling of the behavior of the micro-scale variables to the behavior of macro-scale variables. This in itself presents complications when simrrlating these models. A few researchers have tried to address this problem of couphng of scales in these models. The solid state concentration term defined by the micro scale diffusion equation need to be coupled with the governing equations for the macro-scale to predict electrochemical behavior. Wang and co-workers used volume averaged equations and a parabolic profile approximation for solid-phase concentration. Subramanian et al. developed approximations assuming that the solid-state concentration inside the spherical electrode particle can be expressed as a polynomial in the spatial direction. [Pg.324]

Finally, the use of computer modeling is seen to rapidly increase. This growth is likely to continue or accelerate and chemical synthesis strategies should benefit markedly from it. It can be expected that at first especially shape selective application will profit and it will still be largely a visualization technique to understand how a reactant /product molecule adapts and fits into the microporous environment. The challenge on theoretical chemistry will be how to predict reactivity patterns and molecule transformation inside these pores in order to be able to model the chemical behavior. [Pg.401]

The discovery of the periodic structure of the elements by Dmitri Ivanovich Mendeleev, shown in Fig. 9.1, must be ranked as one the greatest achievements in the history of science. And perhaps the most impressive conceptual accomplishment of quantum mechanics has been its rational account of the origin of the periodic table. Although accurate computations become increasingly more difficult as the number of electrons increases, the general patterns of atomic behavior can be predicted with remarkable accuracy. A modem version of the periodic table is printed on the inside back cover. [Pg.232]


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Behavioral prediction

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