Evaporative ensemble model

The evaporative ensemble model is one in which the cluster ions have been generated in a broad distribution of cluster sizes and internal energies. Hence, the rate constant, k E), is inversely related to the reaction time, f, so that ln( ) = —ln(t) and cnn(A ) = —dln(t). This permits us to convert the derivative in Eq. (10.55) from dln(fe) to dln(f) (Lifshitz, 1993) as... 

With respect to the absolute values of porosity parameters, the data from adsorption isotherms are much less reliable. When considering these data, one has to remember that they actually characterize an equivalent model system composed of an ensemble of open-ended, independent cylindrical capillaries of constant width. This model is far from the real structure of a polymeric adsorbent. Another serious drawback is the rather arbitrary choice between the adsorption and the desorption branches of the hysteresis loop for the calculations. If, indeed, open-ended channels are anticipated in the material, the desorption branch should give more representative results. On the other hand, if closed ink-bottle-type pores are present, the adsorption branch could be used. Filling of a bottle-type pore starts at a low p/p value corresponding to the diameter of the neck and ends at a higher relative pressure corresponding to the size of the bottle s interior, whereas evaporation proceeds at a single p/p value determined by the meniscus in the neck. Partially for this reason, the... 

The ASTM F 1291 and ASTM F 2370 standards are widely used to quantify and compare thermal and evaporative resistance values provided by clothing ensembles having different designs, fabrics, garment layers, closures, and fits (ASTM F 1291, 2010 ASTM F 2370,2010) the thermal and evaporative resistance values of clothing ensembles obtained from these standards can further be used in models to empirically predict the physiological responses of people in different environmental conditions... 

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