Simulation of growth process in random lattice as applied to optical diagnosis of nonstationary mass transfer in heterogeneous media

2002 ◽  
Author(s):  
O. I. Chanilov
Keyword(s):  
Mass Transfer ◽  
Growth Process ◽  
Heterogeneous Media ◽  
Optical Diagnosis ◽  
Random Lattice

Identifying mass transfer influences on Au nanoparticles growth process by centrifugation

2012 ◽  
Vol 48 (59) ◽  
pp. 7353 ◽  
Author(s):  
Bing-Sheng Yin ◽  
Jian-Qiang Hu ◽  
Song-Yuan Ding ◽  
An Wang ◽  
Jason R. Anema ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Growth Process ◽  
Au Nanoparticles

scholarly journals Coupling of mass transfer and reactive transport for nonlinear reactions in heterogeneous media

2010 ◽  
Vol 46 (7) ◽  
Author(s):  
M. Willmann ◽  
J. Carrera ◽  
X. Sanchez-Vila ◽  
O. Silva ◽  
M. Dentz
Keyword(s):  
Mass Transfer ◽  
Reactive Transport ◽  
Heterogeneous Media ◽  
Nonlinear Reactions

scholarly journals Algorithms for Numerical Solution to the Problem of Diffusion in Nanoporous Media

2020 ◽  
pp. 44-52
Author(s):  
N.A. Vareniuk ◽  
N.I. Tukalevska
Keyword(s):  
Mathematical Modeling ◽  
Finite Element Method ◽  
Mass Transfer ◽  
Finite Element ◽  
Numerical Solution ◽  
Heterogeneous Media ◽  
Mutual Influence ◽  
Single Substance ◽  
Nonstationary Diffusion ◽  
Element Method

Introduction. Mathematical modeling of mass transfer in heterogeneous media of microporous structure and construction of solutions to the corresponding problems of mass transfer was considered by many authors [1–9, etc.]. In [6, 7] authors proposed a methodology for modeling mass transfer systems and parameter identification in nanoporous particle media (diffusion, adsorption, competitive diffusion of gases, filtration consolidation), which are described by non-classical boundary and initial-boundary value problems taking into account the mutual influence of micro- and macro-transfer flows, heteroporosity, the structure of microporous particles, multicomponent and other factors. In [8, 9] for a mathematical model of nonstationary diffusion of a single substance in a nanoporous medium described in [2] in the form of a multi-scale differential mathematical problem, the classical problems in the weak formulation were obtained. In this paper, algorithms for solving the above mathematical problems are constructed by using the finite element method. The results of the numerical solution of the test problem are presented. The results confirm the efficiency of the developed algorithms. The purpose is to solve a problem of nonstationary diffusion of single substance in nanoporous medium by constructing discretization algorithms using FEM quadratic basis functions. Results. Algorithms for the numerical solution of the problem of nonstationary diffusion of single substance in a nanoporous medium are proposed. Peculiarities of discretization of the region and construction of the matrix of masses, stiffness, and vector of right-hand sides when solving the problem by using FEM are described. The efficiency of the developed algorithms is confirmed by the results of solving a model example. Keywords: mathematical modeling, numerical methods, nonstationary diffusion, nanoporous medium, finite element method.

Heat and mass transfer simulation of SiC boule growth by sublimation

2000 ◽  
Vol 640 ◽  
Author(s):  
Michel Pons ◽  
Cecile Moulin ◽  
Jean-Marc Dedulle ◽  
Alexandre Pisch ◽  
Bernard Pelissier ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Temperature Field ◽  
Growth Process ◽  
Radiative Heat ◽  
Species Transport ◽  
Density Of Dislocations ◽  
Heterogeneous Reactivity ◽  
Mechanical Approach ◽  
Sublimation Growth

ABSTRACTAn accurate modelling and simulation of the sublimation growth process needs a software taking into account a multitude of highly coupled phenomena: fluid mechanics, convective, conductive and radiative heat transfer, electromagnetic, multicomponent species transport, homogeneous and heterogeneous reactivity and finally thermal and transport databases. The objective of this paper is to combine modelling trends with experimental results to propose explanations and solutions to growth problems. Finally, a simple and generic mechanical approach will show the relations between the density of dislocations and the temperature field.

A new mechanism in the growth process of GaN by HVPE

2000 ◽  
Vol 639 ◽  
Author(s):  
A. Trassoudaine ◽  
E. Aujol ◽  
R. Cadoret ◽  
T. Paskova ◽  
B. Monemar
Keyword(s):  
Mass Transfer ◽  
Experimental Study ◽  
Growth Rate ◽  
Theoretical Analysis ◽  
Growth Process ◽  
High Growth ◽  
High Growth Rate ◽  
General Mechanism ◽  
Surface Kinetics ◽  
Mechanism Of Growth

ABSTRACTExperimental results obtained in two different HVPE reactors are analyzed and compared to the theoretical curves, taking into account the surface kinetics, the mass transfer, and parasitic deposition on the glass walls before the substrate. Unexpected high growth rate values, up to 50νm/h, were measured in conditions of expected substrate etching by HCl. A systematic experimental study of this new phenomenon is presented together with a theoretical analysis. This analysis suggests a new mixed general mechanism of growth.

Analysis of the Sublimation Growth Process of Silicon Carbide Bulk Crystals

1996 ◽  
Vol 423 ◽  
Author(s):  
R. Eckstein ◽  
D. Hofmann ◽  
Y. Makarov ◽  
St. G. Müller ◽  
G. Pensl ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Silicon Carbide ◽  
Optical Properties ◽  
Growth Process ◽  
Numerical Models ◽  
Chemical Processes ◽  
Bulk Crystals ◽  
Electrical And Optical Properties ◽  
Bulk Growth ◽  
Sublimation Growth

AbstractExperimental and numerical analysis have been performed on the sublimation growth process of SiC bulk crystals. Crystallographic, electrical and optical properties of the grown silicon carbide (SIC) crystals have been evaluated by various characterization techniques. Numerical models for the global simulation of SiC bulk growth including heat and mass transfer and chemical processes are applied and experimentally verified.

scholarly journals PATTERNS OF THE VARIATION OF PARAMETERS OF TRANSFER PROCESSES FOR MULTICOMPONENT HYDROCARBON GAS MEDIA UNDER SEPARATION

2020 ◽  
pp. 86-95
Author(s):  
A.V. Dmitriev ◽  
◽  
P.N. Zyatikov ◽  
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Heterogeneous Media ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Gas Mixtures ◽  
Transfer Processes ◽  
Mass Transfer Processes ◽  
Hydrocarbon Gas ◽  
Property Changes

A detailed study of the evolution of local and integral parameters of momentum, heat, and mass transfer processes in hydrocarbon gas mixtures under separation conditions at given temperature and pressure values in working media is carried out within the framework of the principles of equilibrium thermodynamics using the Aspen HYSYS software package, namely, the Peng-Robinson equation of state for real gas mixtures, the principles of statistical mechanics, the approaches of corresponding states, the Chapman-Enskog and the Golubev methods, and the theory of similarity and dimensional analysis. The limits of similarity method applicability in quantitative estimates and qualitative forecasts of the mechanisms and configurations of convective heat and mass transfer in oil treatment units are established. The paper also discusses results of the analog method application in separation process modeling for momentum, heat and mass transfer processes in the problems of oil and gas industry. The conclusions about the aspects of property changes in complex mixtures and about heat and mass transfer intensity during separation, which violate a triple analogy in non-isothermal homogeneous and heterogeneous media, are recommended to take into account when designing real equipment.

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