A Cluster Dynamics Model For Accumulation Of Helium In Tungsten Under Helium Ions And Neutron Irradiation

2012 ◽  
Vol 11 (5) ◽  
pp. 1547-1568 ◽  
Author(s):  
Y. G. Li ◽  
W. H. Zhou ◽  
R. H. Ning ◽  
L. F. Huang ◽  
Z. Zeng ◽  
...  
Keyword(s):  
Diffusion Processes ◽  
Rate Theory ◽  
Dynamics Model ◽  
System Temperature ◽  
Type Size ◽  
Helium Implantation ◽  
Material Conditions ◽  
Reaction Processes ◽  
And Diffusion ◽  
Good Agreement

AbstractA cluster dynamics model based on rate theory has been developed to describe the accumulation and diffusion processes of helium in tungsten under helium implantation alone or synergistic irradiation with neutron, by involving different types of objects, adopting up-to-date parameters and complex reaction processes as well as considering the diffusion process along with depth. The calculated results under different conditions are in good agreement with experiments much well. The model describes the behavior of helium in tungsten within 2D space of defect type/size and depth on different ions incident conditions (energies and fluences) and material conditions (system temperature and existent sinks), by including the synergistic effect of helium-neutron irradiations and the influence of inherent sinks (dislocation lines and grain boundaries). The model, coded as IRadMat, would be universally applicable to the evolution of defects for ions/neutron irradiated on plasma-facing materials.

Meridional Circulation, Turbulence, and Diffusion Processes in Stars

1976 ◽  
Vol 32 ◽  
pp. 109-116 ◽  
Author(s):  
S. Vauclair
Keyword(s):  
Convection Zone ◽  
Diffusion Processes ◽  
Meridional Circulation ◽  
Diffusion Time ◽  
Work In Progress ◽  
First Results ◽  
Stellar Envelopes ◽  
And Diffusion ◽  
Turbulence And Diffusion ◽  
Hr Diagram

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.

NMR-Study of Structure and Diffusion Processes in Li3N

1980 ◽  
Vol 41 (C6) ◽  
pp. C6-28-C6-31 ◽  
Author(s):  
R. Messer ◽  
H. Birli ◽  
K. Differt
Keyword(s):  
Diffusion Processes ◽  
Nmr Study ◽  
And Diffusion

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

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.

Virus Removal by Filtration

1982 ◽  
Vol 14 (4-5) ◽  
pp. 253-256
Author(s):  
N Sriramula ◽  
M Chaudhuri
Keyword(s):  
Experimental Data ◽  
Escherichia Coli ◽  
Cationic Polyelectrolyte ◽  
Electrokinetic Phenomena ◽  
Virus Removal ◽  
Bacterial Virus ◽  
Gravity Settling ◽  
And Diffusion ◽  
Model Virus ◽  
Good Agreement

An investigation was undertaken on the removal of a model virus, bacterial virus MS2 against Escherichia coli, by sand filtration using untreated, and alum or cationic polyelectrolyte treated media, and uncoagulated as well as alum coagulated influent. Data on discrete virus removal were satisfactorily accounted for by electrokinetic phenomena and diffusion. For virus in association with turbidity, filter coefficients computed from experimental data were in good agreement with those predicted by mechanical straining and gravity settling which were the dominant mechanisms for removal of the turbidity particles to which the viruses attached.

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

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.

scholarly journals Influence of Geometry on Thin Layer and Diffusion Processes at Carbon Electrodes

Langmuir ◽  
2021 ◽  
Author(s):  
Qun Cao ◽  
Zijun Shao ◽  
Dale K. Hensley ◽  
Nickolay V. Lavrik ◽  
B. Jill Venton
Keyword(s):  
Thin Layer ◽  
Diffusion Processes ◽  
Carbon Electrodes ◽  
And Diffusion

Decoupling Electrochemical Reaction and Diffusion Processes in Ionically-Conductive Solids on the Nanometer Scale

ACS Nano ◽  
2010 ◽  
Vol 4 (12) ◽  
pp. 7349-7357 ◽  
Author(s):  
Nina Balke ◽  
Stephen Jesse ◽  
Yoongu Kim ◽  
Leslie Adamczyk ◽  
Ilia N. Ivanov ◽  
...  
Keyword(s):  
Diffusion Processes ◽  
Electrochemical Reaction ◽  
Nanometer Scale ◽  
And Diffusion ◽  
Reaction And Diffusion

Rapid Thermal Annealing of Ni/Al/Si and Ni/Si Systems

1986 ◽  
Vol 74 ◽  
Author(s):  
A. Katz ◽  
Y. KOMEM
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Thermal Processing ◽  
Reference System ◽  
Diffusion Processes ◽  
Eutectic Temperature ◽  
Melting Process ◽  
Polycrystalline Layer ◽  
Smooth Interface ◽  
And Diffusion

AbstractThe effect of Rapid Thermal Annealing on phase formation and diffusion processes in the Ni(30 nm) /Al(10 nm)/Si system was studied and coxpared to a Ni(30 nm)/Si reference system. Heat treatments were carried out at temperatures between 400°C and 900°C for 2 seconds.The results obtained by means of TEM, AES and XRD indicated that the Ni/Al/Si system underwent a local melting in the intermediate Al layer at the Al/Si eutectic temperature (577°C). This reaction, due to the rapid melting process, resulted in formation of a unique layered-structure composed of a columnar polycrystalline layer (60 nm thick) of Ni2Si and NiSi adjacent to the Si substrate with relatively smooth interface and an outer layer of two separate polycrystalline films (both about 10 m thick) of Al3Ni (inside) and Ni(Al0.5Si0.5 ) (outside). Under the same rapid thermal processing conditions the Ni/Si reference system underwent a solid state reaction which resulted in the formation of a polycrystalline layer (60 nm thick) composed of Ni2Si and NiSi as well as NiSi2.

Boltzmann’s H-Function and Diffusion Processes

2013 ◽  
Vol 117 (42) ◽  
pp. 12836-12843 ◽  
Author(s):  
Joseph B. Hubbard ◽  
Steven P. Lund ◽  
Michael Halter
Keyword(s):  
Diffusion Processes ◽  
And Diffusion
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