Partial condenser Particle model

Heterogeneous reaction rates on particles in polar stratospheric clouds (PSCs) are more difficult to estimate because of the uncertainties in the type of PSC particles present in the lower stratosphere. The particle composition, volume density and radius must be derived from a thermodynamic model (e.g., Carslaw cl at, 1994 1997). Condensation of HNO3 occurs when the partial pressure of nitric acid in air exceeds the equilibrium vapor pressure Pjjnq F°r example, in the case of nitric acid trihydrates (NAT), if partial pressures are expressed in Torr and the temperature T in Kelvin, we have (Hanson and Mauersberger, 1988)... 

An interesting variant of the cellular automaton approach is the lattice gas automaton. Despite the name, lattice gas automata can be used to simulate reactions in condensed as well as gaseous media. They were introduced initially as an alternative to partial differential equations (PDE) for modeling complex problems in fluid flow (Hardy et al., 1976) and have been adapted to include the effects of chemical reaction as well (Dab et al., 1990). Lattice gas automata are similar to cellular automata in that they employ a lattice, but differ because they focus on the motions of individual particles along the lattice and because they can accoimt... 

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