Results 271 to 280 of about 220,647 (316)

Differential diffusivity of the Turing morphogens

Progress in Biophysics and Molecular Biology, 2019
The Turing morphogens cAMP and ATP are considered as electrolytes. Each is made of a slow anion and fast cation. The unequal diffusion of the of the cation and the anion creates an electric field which accelerates the anion and decelerates the cation. This effect is more pronounced for ATP than cAMP since ATP has higher charge and greater concentration
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ON THE DIFFERENTIAL EQUATIONS OF DIFFUSION

Canadian Journal of Research, 1950
The fundamental bases of the differential equation of diffusion are examined. From a dynamical equation defining the motion of the gas, an equation of continuity expressing the law of conservation of mass, and an equation of state giving the relation between concentration and pressure, the differential equations are derived for the interdiffusion of ...
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Effects of differential diffusion on unsteady diffusion flames

International Communications in Heat and Mass Transfer, 1998
The effects of differential diffusion on unsteady diffusion flames are considered for one-dimensional geometries. A Stefan problem is obtained for a single planar flame separating two semi-infinite regions containing fuel and oxidizer. Non-unity diffusivity ratio and the stoichiometry affect strongly the flame evolution and determine the conditions to ...
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Differentially diffusing scalars in turbulence

Physics of Fluids, 1997
Direct numerical simulation (DNS) data are presented to study differentially diffusing conserved scalars in isotropic turbulence. The two scalars are initially identical but subsequently decorrelate because one is diffusing faster than the other. The main focus of the paper is the study of the time evolution and possible modeling of quantities that ...
Nilsen, Vebjørn, Kosály, George
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The Differential Diagnosis of Diffuse Scleroses in Children

Archives of Pediatrics & Adolescent Medicine, 1960
Introduction Progressive mental deterioration associated with increasingly severe neurologic deficit is a clinical picture which not infrequently confronts the pediatrician. After infection, brain tumor, or subdural hematoma have all been ruled out, the diagnosis of "Schilder's disease" or "diffuse sclerosis" is usually made in the belief that this ...
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BRANCHING DIFFUSION PROCESSES AND SYSTEMS OF REACTION-DIFFUSION DIFFERENTIAL EQUATIONS

Mathematics of the USSR-Sbornik, 1989
Differential equation systems of reaction-diffusion type are considered: \[ \partial u_ k/\partial t=L_ ku_ k+f_ k(t,x,u),\quad x\in D\subseteq R^ r,\quad t>0,\quad u=(u_ 1,...,u_ n),\quad k=1,...,n, \] \[ L_ k=2^{-1}\sum a_ k^{ij}(x)\partial^ 2/\partial x^ i\partial x^ j+\sum b^ i_ k(x)\partial /\partial x^ i.
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Numerical Solution of Diffusion and Reaction–Diffusion Partial Integro-Differential Equations

International Journal of Computational Methods, 2018
In this paper, a collocation method based on Haar wavelet is developed for numerical solution of diffusion and reaction–diffusion partial integro-differential equations. The equations are parabolic partial integro-differential equations and we consider both one-dimensional and two-dimensional cases. Such equations have applications in several practical
Imran Aziz, Imran Khan
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Differential Control of Cellular Gene Expression by Diffusible and Non-Diffusible EGF

Journal of Biochemistry, 2001
Cell gene expression is affected by both the kind and mode of growth factor stimulation (diffusive vs. non-diffusive). Epidermal growth factor (EGF) was pattern-immobilized on a polystyrene plate. Although the growth of the rat phaeochromocytoma cell line PC12 is stimulated by diffusible EGF, and differentiation is stimulated by diffusible nerve growth
Y, Ito, G, Chen, Y, Imanishi, T, Morooka, E, Nishida, Y, Okabayashi, M, Kasuga   +6 more
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Differential diffusion: an oceanographic primer

Progress in Oceanography, 2003
Even where mean gradients of temperature T and salinity S are both stabilizing, it is possible for the larger molecular diffusivity of T to result in differential diffusion, the preferential transfer of T relative to S. The present note reviews existing evidence of differential diffusion as provided by laboratory experiments, numerical simulations, and
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On a differential equation of atmospheric diffusion

Eos, Transactions American Geophysical Union, 1952
Exact closed solutions of the following equation of diffusionequation imagewhere m and n are considered to be independent, are obtained for the following cases: (1) diffusion from a line‐source embedded in a smooth surface; (2) diffusion from a smooth surface; (3) vapor concentration in the wake of an evaporating surface.
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