In this note, necessary and sufficient conditions for the existence of an entropy structure certain classes cross-diffusion systems with diffusion matrix A ( u ) are given, based on results from factorization. The is important in analysis such equations since typically neither symmetric nor positive definite. particular, normal ellipticity all symmetry Onsager implies its definiteness hence str...

Abstract The cross joint is one of the standard connection types for urban water supply pipelines. A pipeline containing joints was taken as research object using NaCl tracer. turbulent mixing characteristics and pollutants at pollutant migration diffusion were studied analysed by numerical analysis experimental measurement. primary purpose to check comprehensive influence six factors pipe diam...

This paper deals with a one-dimensional parabolic cross-diffusion system describing two-species models. The system under consideration is strongly coupled and the coefficients of the equations are allowed to be discontinuous. The existence and uniqueness of nonnegative global solutions are given when one of the cross-diffusion pressures is zero. Our approach to the problem is by an approximatio...