Theory competing

Theory of Steric Stabilization. A detailed description of the competing theories can be obtained from other publications (1-3) and only an outline will be given here. Almost all the acceptable theoretical descriptions have their origins in the Flory-Krigbaum theory (10) for a dilute polymer solution which has been adapted to the case of sterically stabilized particles. 

When you have two competing theories (models) which make exactly the same predictions, the one that is simpler is the better. ... 

Although the mechanism of action of SSRIs in treating alcohol dependence remains unclear, Gorelick and Paredes ( 432) postulate that it is not due to motor inhibition or general sedation. Rather, they believe it may be related to decreased appetite and food intake or a conditioned taste aversion mediated by increased brain serotonin activity. Other competing theories have been summarized by Thomas ( 433) ... 

However, the values of R extracted in this way are less reliable than Rq obtained above from asymptotic analysis, not only because this is a pseudocontact model but also because of uncertainty in v [104]. The rigorous alternative to this model is the straightforward calculation of r from Eq. (3.10), using in Eq. (3.4) an exact k(t) obtained as a solution of the DET equations (3.34) and (3.35). The authentic concentration dependence of k(c) obtained with contact DET will be compared in Section XII.B with other estimates of the same quantity made with a number of competing theories and approximations. 

These and other theories are compared below and, where possible, also with the exact solution [138] provided by DET for the target problem. The common feature of almost all these theories is the contact approximation for the transfer reaction. Therefore the same approximation will be used in IET and MET to compare them with competing theories. 

The vast majority of competing theories of the phenomenon were aimed at specifying the kinetics of the system approaching the equilibrium at ua = uc = 0. It is usually assumed that B particles are present in great excess,... 

However, at still larger concentrations only DET/UT is capable of reaching the kinetic limit of the Stem-Volmer constant and the static limit of the reaction product distribution. On the other hand, this theory is intended for only irreversible reactions and does not have the matrix form adapted for consideration of multistage reactions. The latter is also valid for competing theories based on the superposition approximation or nonequilibrium statistical mechanics. Moreover, most of them address only the contact reactions (either reversible or irreversible). These limitations strongly restrict their application to real transfer reactions, carried out by distant rates, depending on the reactant and solvent parameters. On the other hand, these theories can be applied to reactions in one- and two-dimensional spaces where binary approximation is impossible and encounter theories inapplicable. 

There are therefore two possible explanations for the difference in clearance between our two samples it could have arisen by sheer chance or it could be indicative of a real and consistent effect. The two possible explanations are formally called null and alternative hypotheses. Remember that at this stage these are simply two competing theories. As yet, we have not decided which should be accepted. 

When attempting to use these polymer interface theories (1-22) in planning and interpreting experiments, we encounter two problems associated with the interaction parameter in polymer-polymer systems. First we have to find a way of determining the values of the interaction parameters for the polymer pairs of interest. There is as yet no general experimental procedure which allows us evaluation of the x parameter. Without reliable values of the x parameter, comparative tests of the competing theories can only be made qualitatively. Secondly, to be able to use these theories with more confidence we have to have some idea about the dependence of the x parameter on concentration, temperature, etc. 

Ftirth s model for liquids pictures the liquid as if the vacant spaces in it behave like bubbles in a boiling liquid. Several other versions of liquids as disturbed solids with vacancies exist. The Woodcock and Singer Monte Carlo simulation of KCl shows a structure for liquid KCl similar to that ofFtirth s proposition. However, the most important point in favor of the model is this a contradiction to competing theories, in particular those arising from molecular dynamics, is that it allows an explanation of the heat of activation exhibited for diffusion and viscous flow for all nonassociated liquids, E =3J4RT. ... 

The Arrhenius equation can be derived from theoretical considerations using either of two competing theories, the collision theory and the transition state theory. A more accurate form of Eq. (7-8) includes an additional temperature factor... 

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