Rescaling of diffusion coefficients in two-time scale chemical systems

We study reaction-diffusion systems which involve processes that occur on d ifferent time scales. In particular, we apply a multiscale analysis to obta in a reduced description of the slow dynamics. Under certain assumptions th is reduction yields a new set of reaction-diffusion equations with rescaled diffusion coefficients. We analyze the Selkov model [E. E. Selkov, Eur. J. Biochem. 4, 79 (1968)] and the ferrocyanide-iodide-sulfite reaction [E. C. Edblom et al., J. Am. Chem. Soc. 108, 2826 (1986)] to determine whether th e rescaling in this case may account for the difference of diffusivities th at the formation of certain types of patterns requires. (C) 2000 American I nstitute of Physics. [S0021-9606(99)51848-5].