In this paper diffusion processes with changing modes are studied involving the variable order partial differential equations. We prove the existence and uniqueness theorem of a solution of the Cauchy problem for fractional variable order (with respect to the time derivative) pseudo-differential equations. Depending on the parameters of variable order derivatives short or long range memories ma...

We show how to reconstruct a two-dimensional surface, the drift field, and the diffusion tensor from a planar projection of trajectories of a diffusion process on the surface. The reconstruction is based on the stochastic differential equations of the projected motion, whose drift and diffusion tensor depend on the local curvature of the surface. The reconstruction process requires the solution...

The single-file diffusion of water in the straight channels of two different crystalline microporous aluminosilicates (zeolites bikitaite and Li-ABW) was studied by comparing the results of molecular dynamics computer simulations with the predictions of anomalous diffusion theory modeled by using fractional diffusion equations. At high coverage, the agreement is reasonably good, in particular f...

For more details as regards semigroup theory of operators, see [1]. Fractional differential equations have been widely applied in many important areas, including thermodynamics, porous media, plasma dynamics, cosmic rays, continuum mechanics, electrodynamics, quantummechanics, biological systems and prime number theory [2, 3]. In particular, the fractional diffusion equations have been successf...

In this paper, a non-isothermal two-phase flow in the cathode gas diffusion layer (GDL) of PEM fuel cell is modeled. The governing equations including energy, mass and momentum conservation equations are solved by numerical methods. Also, the optimal values of the effective parameters such as the electrodes porosity, gas diffusion layer (GDL) thickness and inlet relative humidity are calculated...

Oxygen is an essential part of the living organism. It is transported from blood to the body tissue by the systematic circulation and large part of it is stored in the blood flowing in capillaries. In this work we discuss a mathematical model for oxygen transport in tissues. The governing equations are established assuming that the blood is flowing along a co-axial cylindrical capillary inside ...

We describe the mathematical theory of diffusion and heat transport with a view to including some of the main directions of recent research. The linear heat equation is the basic mathematical model that has been thoroughly studied in the last two centuries. It was followed by the theory of parabolic equations of different types. In a parallel development, the theory of stochastic differential e...

In this paper, we discuss the numerical solution of space fractional diffusion equations. The method of solution is based on using Chebyshev polynomials and finite difference with Gauss-Lobatto points. The validity and reliability of this scheme is tested by its application in various space fractional diffusion equations. The obtained results reveal that the proposed method is more accurate and...

This paper develops and analyzes an efficient numerical method for solving elliptic partial differential equations, where the diffusion coefficients are random perturbations of deterministic diffusion coefficients. The method is based upon a multimodes representation of the solution as a power series of the perturbation parameter, and the Monte Carlo technique for sampling the probability space...