Results 81 to 90 of about 1,364,858 (220)

Spectral properties of a Frankl type problem for parabolic-hyperbolic equations

Electronic Journal of Differential Equations, 2018
In this article we study spectral properties of non-local boundary-value problem for an equation of parabolic-hyperbolic type. The non-local condition binds the solution values at points on boundaries of the parabolic and hyperbolic parts of the ...
Makhmud A. Sadybekov, Gulnar Dildabek, Marina B. Ivanova   +2 more
doaj  

Stable difference schemes for hyperbolic–parabolic equations with unknown parameter

Boletín de la Sociedad Matemática Mexicana
AbstractIn the present paper, we study the first and second order of accuracy difference schemes for the approximate solution of the inverse problem for hyperbolic–parabolic equations with unknown time-independent source term. The unique solvability of constructed difference schemes and the stability estimates for their solutions are obtained.
Maksat Ashyraliyev, Maral Ashyralyyeva
openaire   +1 more source

The Role of Dendritic Spines in Water Exchange Measurements With Diffusion MRI: Time‐Dependent Single Diffusion Encoding MRI

NMR in Biomedicine, Volume 39, Issue 10, October 2026.
Geometric exchange between dendritic spines and shafts is often neglected, yet it exhibits the same signature as permeative exchange, biasing NEXI/SMEX measurements. We propose two models: an extended three‐compartment Kärger model that resolves spine–shaft exchange explicitly, and a coarse‐grained Kärger model that absorbs spines into an effective ...
Kadir Şimşek, Arthur Chakwizira, Markus Nilsson, Marco Palombo   +3 more
wiley   +1 more source

The mathematics of suspensions: Kac walks and asymptotic analyticity

Electronic Journal of Differential Equations, 2000
Of concern are suspension flows. These combine directed and random motions and are typically modelled by parabolic partial differential equations.
Eugene C. Eckstein, Jerome A. Goldstein, Mark Leggas   +2 more
doaj  

On the uniqueness and nonuniqueness of weak solutions of hyperbolic-parabolic Volterra equations

Differential and Integral Equations, 1994
The author considers a nonlinear Volterra equation that occurs in viscoelasticity models and reduces to a wave equation or a diffusion equation for suitable choices of the kernel. He indicates conditions on the kernel and the nonlinearity under which the general equation has a unique weak solution, and conditions under which it has infinitely many weak
openaire   +3 more sources

Buoyancy‐Driven Flow at Reservoir Conditions

Geophysical Research Letters, Volume 53, Issue 17, 16 September 2026.
Abstract Quantifying the transition between viscous‐ and buoyancy‐dominated flow during CO2 ${\text{CO}}_{2}$ injection is essential for predicting plume migration and evaluating storage efficiency in saline aquifers. While previous studies have examined the interaction of viscous, gravitational, and capillary forces, the precise definition of buoyancy‐
Almostafa Alhadi, Carlos Torres‐Verdín, David DiCarlo   +2 more
wiley   +1 more source

Numerical Solution of Parabolic Equations by the Box Scheme [PDF]

, 1973
The box scheme proposed by H. B. Keller is a numerical method for solving parabolic partial differential equations. We give a convergence proof of this scheme for the heat equation, for a linear parabolic system, and for a class of nonlinear parabolic ...
Fong, Kirby William
core   +1 more source

Adaptive Observer for Coupled Wave PDE and Infinite ODE With Sampled Data and Unknown Input: Application to Brain Hemodynamics Estimation

International Journal of Adaptive Control and Signal Processing, Volume 40, Issue 9, Page 1932-1944, September 2026.
This article proposes a convergent adaptive observer for a damped wave PDE and an infinite‐dimensional ODE coupled in cascade using sampled‐in‐space ODE state measurements. The proposed observer estimates the distributed states of the PDE and ODE along with unknown PDE parameters and spatial input.
Zehor Belkhatir, Sarah Mechhoud, Taous‐Meriem Laleg‐Kirati   +2 more
wiley   +1 more source

Lack of controllability of the heat equation with memory [PDF]

, 2012
We consider a model for the heat equation with memory, which has infinite propagation speed, like the standard heat equation. We prove that, in spite of this, for every T > 0 there exist square integrable initial data which cannot be steered to hit zero ...
Andrei Halanay, Pandolfi, Luciano
core   +1 more source

Modeling Heavy Metal Sorption and Interaction in a Multispecies Biofilm

Mathematics, 2019
A mathematical model able to simulate the physical, chemical and biological interactions prevailing in multispecies biofilms in the presence of a toxic heavy metal is presented.
Berardino D’Acunto, Luigi Frunzo, Vincenzo Luongo, Maria Rosaria Mattei   +3 more
doaj   +1 more source