scholarly journals Theoretical analysis of the factors, influencing composition uniformity of the cadmium zinc telluride substrates grown by THM

2021 ◽  
Vol 9 (5) ◽  
pp. 402-409
Author(s):  
Alekxander Senchenkov
Keyword(s):  
Thermal Field ◽  
Composition Distribution ◽  
Feed Composition ◽  
Local Composition ◽  
Feed Material ◽  
Factors Influencing ◽  
Composition Variation ◽  
Sample Composition ◽  
Random Character ◽  
Composition Fluctuations

The effect of the sample composition, variation of the temperature field and the feed material non-homogeneity on uniformity of the growing crystal is considered. It is shown that optimization of the solvent composition makes it possible to minimize the jump of the ZnTe concentration at the seed/crystal boundary. The composition fluctuations at variation of the thermal field during crystal growth are smooth enough and relatively non-significant. The feed composition distribution has, as a rule, a random character. Different harmonics of composition distribution non-uniformity in the feed material differently affect the homogeneity of the growing crystal. Longwave non-uniformities in the feed transform into the growing crystal almost completely. At the wavelength equals to a half of the solvent length or shorter, the perturbations of the growing crystal composition are relatively small. Evidently, the cause of the local composition variations, found in real crystals, is, basically, the feed composition non-uniformities

scholarly journals Factors influencing microbial mat composition, distribution and dinitrogen fixation in three western Indian Ocean coral reefs

2012 ◽  
Vol 47 (1) ◽  
pp. 51-66 ◽  
Author(s):  
Loïc Charpy ◽  
Katarzyna A. Palinska ◽  
Raeid M. M. Abed ◽  
Marie José Langlade ◽  
Stjepko Golubic
Keyword(s):  
Indian Ocean ◽  
Coral Reefs ◽  
Western Indian Ocean ◽  
Dinitrogen Fixation ◽  
Microbial Mat ◽  
Composition Distribution ◽  
Factors Influencing

scholarly journals Computer Simulation of C-N-V Precipitates Evolution Based on Local Concentration Fluctuations

2005 ◽  
Vol 500-501 ◽  
pp. 719-728 ◽  
Author(s):  
J. Aldazabal ◽  
Carlos García-Mateo
Keyword(s):  
Ostwald Ripening ◽  
Point Of View ◽  
Small Cells ◽  
Microalloyed Steels ◽  
Local Concentration ◽  
Local Composition ◽  
The Matrix ◽  
System Temperature ◽  
A Cell ◽  
Composition Fluctuations

From a “macroscopic” point of view, steel composition is assumed to vary smoothly along its microstructure. A closer look reveals that, on the atomic level the material composition does not change so smoothly. Single atoms jump randomly along the crystal lattice due to their thermal energy. These random jumps create sporadic zones of the crystal with higher concentration of certain species, and they are responsible for many phenomena, such as precipitation, Ostwald ripening, some phase transformations… This paper proposes a model to simulate the evolution of C-N-V precipitates in microalloyed steels heat treated in the range of warm temperatures (800-900 °C); when the matrix is austenite (fcc), thus taking into account for the local composition fluctuations. The model works by dividing the space into very small cells, containing a single atomic cell each. If during the random movement of atoms a cell that touches a precipitate reaches some critical composition, it is very easy to stick it to the precipitate by changing its “phase”. But it is also possible that some atoms escape from the precipitate by jumping to the austenitic matrix. Both processes happening simultaneously, and which one is leading depends on the atoms energy, i.e. system temperature.

scholarly journals Local composition fluctuations in strongly nonideal binary mixtures

2002 ◽  
Vol 117 (3) ◽  
pp. 1155-1165 ◽  
Author(s):  
Rajesh K. Murarka ◽  
Biman Bagchi
Keyword(s):  
Binary Mixtures ◽  
Local Composition ◽  
Composition Fluctuations

scholarly journals Effect of Fe Content on the As-Cast Microstructures of Ti–6Al–4V–xFe Alloys

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 989
Author(s):  
Ling Ding ◽  
Rui Hu ◽  
Yulei Gu ◽  
Danying Zhou ◽  
Fuwen Chen ◽  
...  
Keyword(s):  
Grain Size ◽  
Solidification Process ◽  
Experimental Methods ◽  
Composition Distribution ◽  
Local Composition ◽  
Levitation Melting ◽  
Fe Content ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Solidification Microstructures

In this work, the evolution of the solidification microstructures of Ti–6Al–4V–xFe (x = 0.1, 0.3, 0.5, 0.7, 0.9) alloys fabricated by levitation melting was studied by combined simulative and experimental methods. The growth of grains as well as the composition distribution mechanisms during the solidification process of the alloy are discussed. The segregation of the Fe element at the grain boundaries promotes the formation of a local composition supercooling zone, thus inhibiting the mobility of the solid–liquid interface and making it easier for the grains to grow into dendrites. With the increase in Fe content, the grain size of the alloy decreased gradually, while the overall decreasing trend was mitigated. The segregation of Fe was more obvious than that of Al and V, and the increase in Fe content had less effect on the segregation of Al and V.

Numerical Simulation of the Impact of Natural Fracture on Fluid Composition Variation Through a Porous Medium

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Ali Papi ◽  
Ali Mohebbi ◽  
S. Ehsan Eshraghi
Keyword(s):  
Fracture Network ◽  
Natural Fracture ◽  
Computational Time ◽  
Single Fracture ◽  
Fracture Aperture ◽  
Fluid Composition ◽  
Composition Distribution ◽  
Engineering Software ◽  
Composition Variation ◽  
The Impact

In order to lessen the computational time in fractured oil reservoir simulations, all fractures are usually assumed to be as one equivalent fracture at the center or around the model. This, specially, has applications in industrial engineering software, where this assumption applies. In this study, using two general contradictory examples, it is shown that ignoring a fracture network and assuming an equivalent single-fracture has no logical justification and results in a considerable error. The effect of fracture aperture on composition distribution of a binary and a ternary mixture was also investigated. These mixtures were C1 (methane)/n-C4 (normal-butane) and C1 (methane)/C2 (ethane)/n-C4 (normal-butane), which were under diffusion and natural convection. Governing equations were numerically solved using matlab. One of the main relevant applications of this study is where permeability and temperature gradient are the key difference between reservoirs. Compositional distribution from this study could be used to estimate initial oil in place. Using this study, one can find the optimum permeability, namely the permeability at which the maximum species separation happens, and the threshold permeability (or fracture aperture), after which the convection imposes its effect on composition distribution. It is found that the threshold permeability is not constant from reservoir to reservoir. Also, one can find that full mixing happens in the model, namely heavy and light densities of top and bottom mix up together in the model. Furthermore, after maximum separation point, convection causes unification of components.

Local composition fluctuations and wetting phenomena

Langmuir ◽  
1990 ◽  
Vol 6 (3) ◽  
pp. 539-542 ◽  
Author(s):  
E. Tronel-Peyroz ◽  
J. M. Douillard ◽  
M. Privat ◽  
R. Bennes
Keyword(s):  
Local Composition ◽  
Wetting Phenomena ◽  
Composition Fluctuations
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