Some Problems In Nonlinear Diffusion

Nonlinear Diffusion Equations

Nonlinear diffusion equations, an important class of parabolic equations, come from a variety of diffusion phenomena which appear widely in nature. They are suggested as mathematical models of physical problems in many fields, such as filtration, phase transition, biochemistry and dynamics of biological groups. In many cases, the equations possess degeneracy or singularity. The appearance of degeneracy or singularity makes the study more involved and challenging. Many new ideas and methods have been developed to overcome the special difficulties caused by the degeneracy and singularity, which enrich the theory of partial differential equations.This book provides a comprehensive presentation of the basic problems, main results and typical methods for nonlinear diffusion equations with degeneracy. Some results for equations with singularity are touched upon.

Nonlinear Diffusion of Electromagnetic Fields

Nonlinear Diffusion of Electromagnetic Fields covers applications of the phenomena of non-linear diffusion of electromagnetic fields, such as magnetic recording, electromagnetic shielding and non-destructive testing, development of CAD software, and the design of magnetic components in electrical machinery. The material presented has direct applications to the analysis of eddy currents in magnetically nonlinear and hysteretic conductors and to the study of magnetization processes in electrically nonlinear superconductors. This book will provide very valuable technical and scientific information to a broad audience of engineers and researchers who are involved in these diverse areas. - Contains extensive use of analytical techniques for the solution of nonlinear problems of electromagnetic field diffusion - Simple analytical formulas for surface impedances of nonlinear and hysteretic media - Analysis of nonlinear diffusion for linear, circular and elliptical polarizations of electromagnetic fields - Novel and extensive analysis of eddy current losses in steel laminations for unidirectional and rotating magnetic fields - Preisach approach to the modeling of eddy current hysteresis and superconducting hysteresis - Extensive study of nonlinear diffusion in superconductors with gradual resistive transitions (scalar and vertorial problems)

Some Problems in Nonlinear Diffusion