A simple thermodynamical model to estimate the rate of depletion of nocturnal low level inversion layer

The low level inversion, be it that of ground based or elevated, plays a significant role in the dispersion of polluted particles and in aviation meteorology. The rate of rise of the ground based inversion top and the base of elevated inversion causes the decrease of inversion strength and thereby permits vertical mixing of pollutants as the stability of the atmosphere is reduced. A simple thermodynamical model using the global radiation and vertical temperature profile has been proposed to estimate the rate of rise of (i) the ground based inversion top and (ii) the base of the elevated inversion. The depth of inversion thus estimated can be used in the pollution/fog dispersion models. The model is simple and operationally practicable. The limitations of the model are also discussed.

Influence of Open-Porous System on the Solid-State Phase Transition in 1-Octadecene

The solid-state phase transition in the silica gel–1-octadecene system has been studied at various temperatures with the help of differential scanning calorimetry and FTIR spectroscopy. Silica gels KSK-2.5, KSS-4, and Silica Gel 60 with different surface parameters are used. The temperature of the solid-state phase transition in the silica gel–1-octadecene system is shown to linearly depend on the ratio between the pore surface area and the pore volume. The energy characteristics of 1-octadecene nanocrystals in the surface layer are calculated in the framework of a thermodynamical model of crystal melting in pores.