A parallel multigrid solver applied to the simulation of thermal oxidation and diffusion processes

This paper gives the first results of a work in progress, in collaboration with G. Michaud and G. Vauclair. It is a first attempt to compute the effects of meridional circulation and turbulence on diffusion processes in stellar envelopes. Computations have been made for a 2 Mʘstar, which lies in the Am - δ Scuti region of the HR diagram.Let us recall that in Am stars diffusion cannot occur between the two outer convection zones, contrary to what was assumed by Watson (1970, 1971) and Smith (1971), since they are linked by overshooting (Latour, 1972; Toomre et al., 1975). But diffusion may occur at the bottom of the second convection zone. According to Vauclair et al. (1974), the second convection zone, due to He II ionization, disappears after a time equal to the helium diffusion time, and then diffusion may happen at the bottom of the first convection zone, so that the arguments by Watson and Smith are preserved.

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NMR-Study of Structure and Diffusion Processes in Li3N

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1980607 ◽

1980 ◽

Vol 41 (C6) ◽

pp. C6-28-C6-31 ◽

Cited By ~ 2

Author(s):

R. Messer ◽

H. Birli ◽

K. Differt

Keyword(s):

Diffusion Processes ◽

Nmr Study ◽

And Diffusion

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Effect of cluster-gradient architecture of nanostructured topocomposites on features of tribointeraction with heterophased material

10.36652/1813-1336-2020-16-3-130-135 ◽

2020 ◽

pp. 130-135

Author(s):

D.N. Korotaev ◽

K.N. Poleshchenko ◽

E.N. Eremin ◽

E.E. Tarasov

Keyword(s):

Wear Resistance ◽

Titanium Alloy ◽

Energy Dissipation ◽

Phase Structure ◽

Diffusion Processes ◽

Structural Phase ◽

High Wear Resistance ◽

Wear Characteristics ◽

And Diffusion

The wear resistance and wear characteristics of cluster-gradient architecture (CGA) nanostructured topocomposites are studied. The specifics of tribocontact interaction under microcutting conditions is considered. The reasons for retention of high wear resistance of this class of nanostructured topocomposites are studied. The mechanisms of energy dissipation from the tribocontact zone, due to the nanogeometry and the structural-phase structure of CGA topocomposites are analyzed. The role of triboactivated deformation and diffusion processes in providing increased wear resistance of carbide-based topocomposites is shown. They are tested under the conditions of blade processing of heat-resistant titanium alloy.

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Parallel Multigrid Solver for Unstructured Grid

Journal of Software ◽

10.3724/sp.j.1001.2013.04241 ◽

2013 ◽

Vol 24 (2) ◽

pp. 391-404

Author(s):

Zong-Zhe LI ◽

Zheng-Hua WANG ◽

Lu YAO ◽

Wei CAO

Keyword(s):

Unstructured Grid ◽

Multigrid Solver ◽

Parallel Multigrid

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Certain Problems with the Application of Stochastic Diffusion Processes for the Description of Chemical Engineering Phenomena. Diffusional Change of Solid Particle Size

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19960536 ◽

1996 ◽

Vol 61 (4) ◽

pp. 536-563

Author(s):

Vladimír Kudrna ◽

Pavel Hasal

Keyword(s):

Particle Size ◽

Solid Particle ◽

Chemical Engineering ◽

Diffusion Processes ◽

Granular Systems ◽

Size Distributions ◽

Particle Size Distributions ◽

Diffusion Term ◽

Population Balances ◽

And Diffusion

To the description of changes of solid particle size in population, the application was proposed of stochastic differential equations and diffusion equations adequate to them making it possible to express the development of these populations in time. Particular relations were derived for some particle size distributions in flow and batch equipments. It was shown that it is expedient to complement the population balances often used for the description of granular systems by a "diffusion" term making it possible to express the effects of random influences in the growth process and/or particle diminution.

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