K. Dworecki | Searcharxiv

arXiv2005

How to Measure Subdiffusion Parameters

We propose a method to measure the subdiffusion parameter $α$ and subdiffusion coefficient $D_α$ which are defined by means of the relation $ =\frac{2D_α} {Γ(1+α)} t^α$ where $ $ denotes a mean square displacement of a random walker starting from $x=0$ at the initial time $t=0$. The method exploits a membrane system where a substance of interest is transported in a solvent from one vessel to another across a thin membrane which plays here only an auxiliary role. We experimentally study a diffusion of glucose and sucrose in a gel solvent, and we precisely determine the parameters $α$ and $D_α$, using a fully analytic solution of the fractional subdiffusion equation.

cond-mat.stat-mech↗

arXiv2005

Measuring subdiffusion parameters

We propose a method to extract from experimental data the subdiffusion parameter $α$ and subdiffusion coefficient $D_α$ which are defined by means of the relation $ =2D_α/Γ(1+α) t^α$ where $ $ denotes a mean square displacement of a random walker starting from $x=0$ at the initial time $t=0$. The method exploits a membrane system where a substance of interest is transported in a solvent from one vessel to another across a thin membrane which plays here only an auxiliary role. Using such a system, we experimentally study a diffusion of glucose and sucrose in a gel solvent. We find a fully analytic solution of the fractional subdiffusion equation with the initial and boundary conditions representing the system under study. Confronting the experimental data with the derived formulas, we show a subdiffusive character of the sugar transport in gel solvent. We precisely determine the parameter $α$, which is smaller than 1, and the subdiffusion coefficient $D_α$.

cond-mat.stat-mech↗