Effects of randomly inhomogeneous diffusion barrier on impurity transport in a double-porous medium Peter S. Kondratenko, Vladimir A. Kutsepalov and Leonid V. Matveev Eur. Phys. J. B, 92 9 (2019) 210 Published online: 16 September 2019 DOI: 10.1140/epjb/e2019-100290-y