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

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.

Numerical Analysis of an Electromagnetic CZ-Si Growth Process by 3D Global Modeling

2005 ◽  
Author(s):  
Lijun Liu ◽  
Satoshi Nakano ◽  
Koichi Kakimoto
Keyword(s):  
Mass Transfer ◽  
Electric Current ◽  
Heat And Mass Transfer ◽  
Growth Process ◽  
Three Dimensional ◽  
Transverse Magnetic ◽  
Thermal Flow ◽  
Global Modeling ◽  
Silicon Melt ◽  
Crystal Interface

Three-dimensional (3D) thermal flow of silicon melt in an electromagnetic Czochralski (CZ) system was numerically investigated with a recently developed 3D global model. The electromagnetic CZ system was established with a transverse magnetic field and an injected electric current applied on the melt surface. Different azimuthal and radial positions of the electrode on the melt surface were taken into account to investigate their influences on the heat and mass transfer in the melt, as well as on the melt-crystal interface. The influence of the electric current direction on the melt flow pattern and temperature distribution was also demonstrated. The results showed that the position of the electrode on the melt surface and the direction of the applied electric current play an important role in controlling the heat and mass transfer in the silicon melt.

scholarly journals Modeling the Interactions of Lactobacillus curvatus Colonies in Solid Medium: Consequences for Food Quality and Safety

2002 ◽  
Vol 68 (7) ◽  
pp. 3432-3441 ◽  
Author(s):  
P. K. Malakar ◽  
D. E. Martens ◽  
W. van Breukelen ◽  
R. M. Boom ◽  
M. H. Zwietering ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Lactic Acid ◽  
Growth Process ◽  
Solid Medium ◽  
Lactic Acid Production ◽  
Lactobacillus Curvatus ◽  
Mass Transfer Limitation ◽  
Inoculation Density ◽  
Food Quality And Safety ◽  
Rate Interaction

ABSTRACT The growth process of Lactobacillus curvatus colonies was quantified by a coupled growth and diffusion equation incorporating a volumetric rate of lactic acid production. Analytical solutions were compared to numerical ones, and both were able to predict the onset of interaction well. The derived analytical solution modeled the lactic acid concentration profile as a function of the diffusion coefficient, colony radius, and volumetric production rate. Interaction was assumed to occur when the volume-averaged specific growth rate of the cells in a colony was 90% of the initial maximum rate. Growth of L. curvatus in solid medium is dependent on the number of cells in a colony. In colonies with populations of fewer than 105 cells, mass transfer limitation is not significant for the growth process. When the initial inoculation density is relatively high, colonies are not able to grow to these sizes and growth approaches that of broth cultures (negligible mass transfer limitation). In foods, which resemble the model solid system and in which the initial inoculation density is high, it will be appropriate to use predictive models of broth cultures to estimate growth. For a very low initial inoculation density, large colonies can develop that will start to deviate from growth in broth cultures, but only after large outgrowth.

scholarly journals Optimization of a Hydrothermal Growth Process for Low Resistance 1D Fluorine-Doped Zinc Oxide Nanostructures

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Muhammad L. M. Napi ◽  
S. M. Sultan ◽  
Razali Ismail ◽  
Mohd K. Ahmad ◽  
G. M. T. Chai
Keyword(s):  
Zinc Oxide ◽  
Growth Process ◽  
Au Nanoparticles ◽  
Hydrothermal Reaction ◽  
Hydrothermal Growth ◽  
Zinc Oxide Nanostructures ◽  
Hydrothermal Conditions ◽  
Hydrothermal Temperature ◽  
Gold Sputtering

Design of Experiment (DOE) has been used for the optimization of a hydrothermal growth process of one-dimensional fluorine-doped zinc oxide (1D-FZO). Box-Behnken design was used in the DOE which includes three design points on each of the synthesis condition parameters. The condition parameters were the gold sputtering time (10 s, 15 s, and 20 s), hydrothermal reaction time (3 hours, 6.5 hours, and 10 hours), and hydrothermal temperature (50°C, 75°C, and 100°C). This statistical method of DOE was used to study the effects of these hydrothermal conditions on the quality of 1D-FZO produced. Au nanoparticles were used as the catalyst to enable the growth of the 1D-FZO. The XRD and EDX analysis confirmed the formation of polycrystalline FZO with the presence of fluorine, zinc, and oxygen elements. SEM observations indicated that the sputtering time of the Au nanoparticles has significant effect on the morphology and growth process of 1D-FZO. The lowest resistance value of 22.57 Ω was achieved for 1D-FZO grown with the longest Au sputtering time at growth temperature below 100°C.

Assessment of SiC Crystal Chemistry during the PVT Growth Process: Coupled Numerical Modeling and Thermodynamics Approach

2015 ◽  
Vol 821-823 ◽  
pp. 96-99
Author(s):  
Kanaparin Ariyawong ◽  
Christian Chatillon ◽  
Elisabeth Blanquet ◽  
Jean Marc Dedulle ◽  
Didier Chaussende
Keyword(s):  
Numerical Simulation ◽  
Solid Solution ◽  
Mass Transfer ◽  
Numerical Modeling ◽  
Crystal Chemistry ◽  
Growth Process ◽  
Growth Conditions ◽  
Thermodynamic Calculations ◽  
Key Issues

Numerical simulation appeared till now as the only tool able to describe the SiC growth by PVT process, while the chemistry of the Si-C system and its coupling to mass transfer were not considered in a satisfactory way. To assess the chemistry of SiC crystal, the coupling of numerical and thermodynamic calculations computed by FEM, and by treating SiC as a solid solution, respectively, is presented. This enables the possibilities to control the activity of each component in SiC crystal during the growth. The link between growth conditions and SiC crystal chemistry could be one of the key issues to link the growth and the occurrence of cubic or hexagonal polytypes.

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