Hristov J.2024-07-102024-07-102024-07-102024-07-102017-01-010354-983610.2298/TSCI160427247HSCOPUS_ID:85015621310https://rlib.uctm.edu/handle/123456789/423The paper addresses approximate integral-balance approach to a time-fractional diffusion equation of order 0 < μ < 1 with a time-dependent diffusion coefficient of power-law type D(t) = D0tβ where 0 < β < 1. The form of the solution spreading in a semi-infinite medium through an analysis of the second moment of the approximate solution reveals that depending on the sum μ + β the solution can model subdiffusive (μ + β < 1), superdiffusive (μ + β > 1), or Gaussian (μ + β = 1) process of transport. The optimal exponents of the approximate parabolic profiles have been determined by minimization the mean squared error of approximation over the penetration depth.enArticle