Cavity theory

Attempts have been made to distinguish between these theories on the basis of the AH° and values anticipated for the two theories, but it may be illusory to think of them as independent alternatives. The eavity model has been criticized on the basis that it eannot account for certain observations such as the denaturing effect of urea, but it must be noted that the cavity theory includes not only the cavity term AAy, but also a term (or terms) for the interaction of the solutes and the solvent. A more eogent objeetion might be to the extension of the macroseopic concepts of surface area and tension to the molecular scale. A demonstration of the validity of the cavity concept has been made with silanized glass beads, which aggregate in polar solvents and disperse in nonpolar solvents. 

Following the expansion cavity theory, Johnson (1985) proposed a model in which the contact surface of the indenter is encased within a hemispherical core. 

With the help of the condensation criterion from Sec. IV.B, the extent of the correlation-enhanced condensation can be further quantified. The Manning fraction from the molecular dynamics simulation increases only by a fairly small amount. It is at most 4% larger than the PB value. This translates to an effective Manning parameter eff = 1/(1 — fe) being 5-10% larger than the bare one. This increase is very accurately captured by the Debye-Hiickel hole-cavity theory. Its prediction for fe is at most 1% smaller than the value obtained in the simulation. Interestingly, it is even independent of density. This, however, is not a feature to be generally expected and should therefore not be overinterpreted. 

Still there is no chance to find some experimental criterion for checking each of the described theories. It should be stressed that the polaron model of the cavity with the localized electron is definitely proved by the volume expansion of ammonia when adding the alkali metal to it (38). Besides, on the basis of any of the cavity theories it becomes comparatively easy to explain the results of investigation of e tr photoannealing—i.e., the dispersion of the trap depths, and temperature dependence of ExmaX of the electrons. In this connection it is rather desirable to find some approach to determining the sizes of the cavities for the electrons in the irradiated polar systems, as it has been done for the metal-ammonia solutions. 

The advance in the dosimetric properties of phosphors was mostly empirical. More theoretical work on the effects involved in the preparation of phosphors and in the TL emission may lead to more efficient phosphors, hr the present situation it happens that minor changes in the preparation of a phosphor lead to changes by orders of magnitude in the intensity of the dosimetric TL peak (see, for example, Dhopte et al. 1991a). Burlin and co-workers have developed the cavity theory (sect. 3.2.3) to explain the effect of the grain sizes on the sensitivity of TL detectors. Unfortunately, the use of this theory was limited presumably because of additional effects which masked the cavity effect. 

An effective cavity theory for the degradation of Young s modulus... 

GleadaU et al. (2014a,b) developed an effective cavity theory using the atomic finite element method (AFEM) for the change of Young s modulus during degradation... 

Figure 9.29 Experimental data of Duek et al. are shown for (a) number-average molecular weight and crystallinity, and (b) Young s modulus. Also shown in (b) is a representative fitting of the effective cavity theory model of GleadalP for Young s modulus degradation.

Robinson J, Kingman S, Irvine D et al (2010) Understanding microwave heating effects in single mode type cavities-theory and experiment. Phys Chem Chem Phys 12 4750-4758... 

Chandos and Chandos (1974) Radiometric Properties of Diffuse Wall Cavity Sources by R. J. Chandos and R. E. Chandos, Appl. Opt. 13, 2142. Overview of cavity theory cites earlier work. 

In numerous solvation models, the partition of a solute between the gas phase and a solvent (or stationary phase) may be described by a cavity theory of solution (Vitha Carr, 2006 Abraham et al., 1999) in which the solvation process is divided into three steps. In the step 1, a cavity of suitable size to accommodate the solute is created in the solvent (Figure 1). This process is endoergic because work is required to disrupt solvent-solvent interactions. In the... 

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