2 research outputs found
Exact steady state solution of the Boltzmann equation: A driven 1-D inelastic Maxwell gas
The exact nonequilibrium steady state solution of the nonlinear Boltzmann
equation for a driven inelastic Maxwell model was obtained by Ben-Naim and
Krapivsky [Phys. Rev. E 61, R5 (2000)] in the form of an infinite product for
the Fourier transform of the distribution function . In this paper we
have inverted the Fourier transform to express in the form of an
infinite series of exponentially decaying terms. The dominant high energy tail
is exponential, , where and the amplitude is given in terms of a converging
sum. This is explicitly shown in the totally inelastic limit ()
and in the quasi-elastic limit (). In the latter case, the
distribution is dominated by a Maxwellian for a very wide range of velocities,
but a crossover from a Maxwellian to an exponential high energy tail exists for
velocities around a crossover velocity , where .
In this crossover region the distribution function is extremely small, .Comment: 11 pages, 4 figures; a table and a few references added; to be
published in PR
Apparent Rate Constant for Diffusion-Controlled Three molecular (catalytic) reaction
We present simple explicit estimates for the apparent reaction rate constant
for three molecular reactions, which are important in catalysis. For small
concentrations and , the apparent reaction rate constant depends only on
the diffusion coefficients and sizes of the particles. For small concentrations
and , it is also time -- dependent. For large concentrations, it gains
the dependence on concentrations.Comment: 12 pages, LaTeX, Revised: missing ref. for important paper by G.
Oshanin and A. Blumen was added and minor misprints correcte