Programme

P.24 -- Poster, NCTP-39

Date: Wednesday, 30-07-2014

Time: 14h00 - 15h30

THE GENERAL SOLUTION OF BACKWARD DIFFUSION EQUATION

Vu Ba Dung (1), Dao Thi Trang (2) and Dinh Van Thien (1)

(1) Hanoi University of Mining and Geology (2) Hanoi National University of Education

The diffusion is elementary and universal process in natural. The rate law of diffusion had been formulated by A. Fick in which the diffusion flux is proportional to the gradient of the concentration and diffusion flux goes from regions of higher concentration to regions of lower concentration. If the thermal velocity of molecules in lower concentration area is greater than velocity of molecules in higher concentration area, there are two molecule fluxes, one of them is the advection flux and the other is backward diffusion flux. Both the advection flux and the backward diffusion flux are going from regions of lower concentration to regions of higher concentration (backward diffusion process). In this paper the backward diffusion process is contrary to the fundamental laws of diffusion as Fick’s law and Onsager’s laws, but which are explained. Moreover, the equation of backward diffusion and the solution of which are also presented and discussed.

Presenter: Vu Ba Dung