Diffusion coefficient analysis method using data statistical processing to reduce interference fringe noise effects

Abstract

We proposed a simple statistical analysis method of minute concentration changes for measuring diffusion coefficient with reduced interference fringe noise effect. In the "Soret-Facet Mission," the one-dimensional diffusion equation discretized by the finite difference method was applied for temporal homogenization processes of the minute concentration gradient induced by the Soret effect with random noises. Measured diffusion coefficient D exp was determined by evaluating the obtained apparent diffusion coefficient distributions D. The measured value D exp obtained by the proposed processes was found to be valid because the measured value D exp was close to the theoretical one D th calculated by the Darken equation and the reference one D ref calculated in" Facet Mission" in the same solution system, respectively. In addition, by analyzing about 1/16th of the total field of view, it was possible to obtain a diffusion coefficient that are more than 95% convergent for the measured value D exp obtained from the full field of view analysis.