Results 11 to 20 of about 62 (62)

Modeling and Simulation of a Bacterial Biofilm That Is Controlled by pH and Protonated Lactic Acids

open access: yesComputational and Mathematical Methods in Medicine, Volume 9, Issue 1, Page 47-67, 2008., 2008
We present a mathematical model for growth and control of facultative anaerobic bacterial biofilms in nutrient rich environments. The growth of the microbial population is limited by protonated lactic acids and the local pH value, which in return are altered as the microbial population changes.
Hassan Khassehkhan, Hermann J. Eberl
wiley   +1 more source

A free boundary problem describing the saturated‐unsaturated flow in a porous medium

open access: yesAbstract and Applied Analysis, Volume 2004, Issue 9, Page 729-755, 2004., 2004
This paper presents a functional approach to a nonlinear model describing the complete physical process of water infiltration into an unsaturated soil, including the saturation occurrence and the advance of the wetting front. The model introduced in this paper involves a multivalued operator covering the simultaneous saturated and unsaturated flow ...
Gabriela Marinoschi
wiley   +1 more source

On a nonlinear compactness lemma in Lp(0, T; B)

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 27, Page 1725-1730, 2003., 2003
We consider a nonlinear counterpart of a compactness lemma of Simon (1987), which arises naturally in the study of doubly nonlinear equations of elliptic‐parabolic type. This paper was motivated by previous results of Simon (1987), recently sharpened by Amann (2000), in the linear setting, and by a nonlinear compactness argument of Alt and Luckhaus ...
Emmanuel Maitre
wiley   +1 more source

The hp version of Eulerian‐Lagrangian mixed discontinuous finite element methods for advection‐diffusion problems

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 53, Page 3385-3411, 2003., 2003
We study the hp version of three families of Eulerian‐Lagrangian mixed discontinuous finite element (MDFE) methods for the numerical solution of advection‐diffusion problems. These methods are based on a space‐time mixed formulation of the advection‐diffusion problems.
Hongsen Chen, Zhangxin Chen, Baoyan Li
wiley   +1 more source

The nonlinear diffusion equation of the ideal barotropic gas through a porous medium

open access: yesOpen Mathematics, 2017
The nonlinear diffusion equation of the ideal barotropic gas through a porous medium is considered. If the diffusion coefficient is degenerate on the boundary, then the solutions may be controlled by the initial value completely, the well-posedness of ...
Zhan Huashui
doaj   +1 more source

Critical global asymptotics in higher‐order semilinear parabolic equations

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 60, Page 3809-3825, 2003., 2003
We consider a higher‐order semilinear parabolic equation ut = −(−Δ)mu − g(x, u) in ℝN × ℝ+, m > 1. The nonlinear term is homogeneous: g(x, su) ≡ |s|p−1sg(x, u) and g(sx, u) ≡ |s|Qg(x, u) for any s ∈ ℝ, with exponents P > 1, and Q > −2m. We also assume that g satisfies necessary coercivity and monotonicity conditions for global existence of solutions ...
Victor A. Galaktionov
wiley   +1 more source

Anisotropic nonlinear diffusion with absorption: existence and extinction

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 19, Issue 3, Page 427-434, 1996., 1994
The authors prove that the nonlinear parabolic partial differential equation with homogeneous Dirichlet boundary conditions and a nonnegative initial condition has a nonnegative generalized solution u. They also give necessary and sufficient conditions on the constitutive functions φij and f which ensure the existence of a time t0 > 0 for which u ...
Alan V. Lair, Mark E. Oxley
wiley   +1 more source

A system of impulsive degenerate nonlinear parabolic functional‐differential inequalities

open access: yesInternational Journal of Stochastic Analysis, Volume 8, Issue 1, Page 59-68, 1995., 1994
A theorem about a system of strong impulsive degenerate nonlinear parabolic functional‐differential inequalities in an arbitrary parabolic set is proved. As a consequence of the theorem, some theorems about impulsive degenerate nonlinear parabolic differential inequalities and the uniqueness of a classical solution of an impulsive degenerate nonlinear ...
Ludwik Byszewski
wiley   +1 more source

On the parabolic potentials in degenerate‐type heat equation

open access: yesInternational Journal of Stochastic Analysis, Volume 4, Issue 2, Page 147-160, 1991., 1991
Using distributions theory technique we introduce parabolic potentials for the heat equation with one time‐dependent coefficient (not everywhere positive and continuous) at the highest space‐derivative, discuss their properties, and apply obtained results to three illustrative problems.
Igor Malyshev
wiley   +1 more source

Null controllability for a degenerate population model in divergence form via Carleman estimates

open access: yesAdvances in Nonlinear Analysis, 2019
In this paper we consider a degenerate population equation in divergence form depending on time, on age and on space and we prove a related null controllability result via Carleman estimates.
Fragnelli Genni
doaj   +1 more source

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