The order-disorder transformation at supercooled melt/crystal transition region of binary melts (I) the master equation

1985 ◽  
Vol 20 (8) ◽  
pp. 1007-1014 ◽  
Author(s):  
Yu. D. Chistyakov ◽  
Yu. A. Baikov ◽  
H. G. Schneider ◽  
V. Ruth
Keyword(s):  
Master Equation ◽  
Transition Region ◽  
Crystal Transition ◽  
Supercooled Melt

scholarly journals Особенности микрокристаллизации 50 % двухкомпонентных металлических расплавов в модели переходной двухфазной зоны в диффузионно-релаксационном режиме

2019 ◽  
Vol 21 (2) ◽  
pp. 164-181
Author(s):  
Yury A. Baikov ◽  
Nikolai I. Petrov ◽  
Margorita I. Timoshina ◽  
Evgeniy V. Akimov
Keyword(s):  
Transition Region ◽  
Steady State Solution ◽  
Phase Zone ◽  
Two Phase ◽  
Mathematical Mode ◽  
Metal Melts ◽  
Two Component ◽  
Crystal Transition ◽  
Supercooled Melt ◽  
Metallic Melts

    В диффузионно-релаксационном режиме кристаллизации 50% двухкомпонентных металлических расплавов в модели переходной  двухфазной зоны оценены термодинамические параметры, при которых возможно образование полностью разупорядоченной  двухкомпонентной кристаллической фазы с простой кубической элементарной решеткой стехиометрического состава. Исследована область вблизи точки разупорядочения кристаллической фазы и установлен закон стремления параметра дальнего порядка к нулю при достижении критической температуры (переохлаждения) системы двухкомпонентный расплав-кристалл. Установлены кинетические особенности роста кристаллической фазы в точке разупорядочения. Установлен закон восстановления упорядоченной двухкомпонентной кристаллической фазы во времени. Оценены возможные значения времен релаксации при переходе из разупорядоченной двухкомпонентной кристаллической фазы с простой кубической элементарной ячейкой к полностью  упорядоченной. Установлены кинетические особенности образования полностью упорядоченного двухкомпонентного кристалла.       REFERENCES Sarkisov P. D., Baikov Yu. A., Meshalkin V. P. Matematicheskoe modelirovanie kristallizatsii odno- i dvukhkomponentnykh metallicheskikh rasplavov [The one- and binary metallic melts mathematical mode ling crystallization]. Moscow, Physmatlit Publ., 2003. 378 p. (in Russ.) Baikov Y. A., Petrov N. I. Structure of the Transitive Two-Phase Zone in Crystallization of Two-Component Metal Melts. Russian Physics Journal, 2014, v. 57(4), pp. 459–468. https://doi.org/10.1007/s11182-014-0262-2 Baikov Yu. A., Petrov N. I. Special Features of disordering in Crystallization of Two-Component Metal Melts in the Model of Two-Phase Transitive Zone. Russian Physics Journal, 2014, v. 57(5), pp. 598–614. https://doi.org/10.1007/s11182-014-0282-y Petrov N. I. The Crystal Disordering Study When Growing From the Binary Metallic Melts. National University of Science and Technology «MISiS» Dis. Cand. Phys.-Mat. Sci. Moscow, 2017, 180 p. URL: http:// misis.ru/fi les/6902/Petrov_AR.pdf (in Russ.) Sarkissov P. D., Baikov Yu. A., Meshalkin V. P. Order-disorder processes in crystals when crystallizing binary metallic melts. Doklady Physics, 2003, v. 48(6), pp. 290–295. https://doi.org/10.1134/1.1591316 Chistyakov Yu. D., Baikov Yu. A., Schneider H. G., Ruth V. The order-disorder transformation at supercooled melt/crystal transition region of binary melts (I) the master equation. Crystal Research and Technology, 1985, v. 20(8), pp. 1007–1014. https://doi.org/10.1002/crat.2170200802 Chistyakov Yu. D., Baikov Yu. A., Schneider H. G., Ruth V. The order-disorder transformation at supercooled melt/crystal transition region of binary melts (II) the steady state solution // Crystal Research and Technology, 1985, v. 20(9), pp. 1149–1156. https://doi.org/10.1002/crat.2170200903 Guinier A. J., Griffoul R. Compte Rendu, 1945, v. 221, pp. 121. Guinier A. J. Imperfections of crystal lattices as investigated by the study of X-ray diffuse scattering // Proceedings of the Physical Society, 1945, v. 57(4), pp. 310–324. https://doi.org/10.1088/0959-5309/57/4/306 Schneider H. G. Collection: Advances in Epitaxy and Endotaxy. Akademiai Kiado, Budapest, 1976, p. 23. Chistyakov Yu. D., Baikov Yu. A. Collection: Advances in Epitaxy and Endotaxy. Akademiai Kiado, Budapest, 1976, p. 159. Chistyakov Yu. D., Baikov Yu. A. Collection: Advances in Epitaxy and Endotaxy. Akademiai Kiado, Budapest, 1976, p. 257.

Effects of Ambipolar Diffusion on Prominence Thread Models

1994 ◽  
Vol 144 ◽  
pp. 315-321 ◽  
Author(s):  
M. G. Rovira ◽  
J. M. Fontenla ◽  
J.-C. Vial ◽  
P. Gouttebroze
Keyword(s):  
Energy Balance ◽  
Transition Region ◽  
Ambipolar Diffusion ◽  
Line Profiles ◽  
Balance Equations ◽  
Model Calculations ◽  
Partial Frequency ◽  
Frequency Redistribution ◽  
Partial Frequency Redistribution ◽  
Theoretical Structure

AbstractWe have improved previous model calculations of the prominence-corona transition region including the effect of the ambipolar diffusion in the statistical equilibrium and energy balance equations. We show its influence on the different parameters that characterize the resulting prominence theoretical structure. We take into account the effect of the partial frequency redistribution (PRD) in the line profiles and total intensities calculations.

SPECTRAL ANALYSIS OF NOISE IN POOL BOILING IN THE TRANSITION REGION

1974 ◽  
Author(s):  
V. I. Tolubinsky ◽  
A.M. Kltchigin ◽  
S.G. Povsten
Keyword(s):  
Spectral Analysis ◽  
Transition Region ◽  
Pool Boiling

Crystal Transition and Drug-excipient Compatibility of Clarithromycin in Sustained Release Tablets

2020 ◽  
Vol 16 (7) ◽  
pp. 950-959
Author(s):  
Yu Li ◽  
Xiangwen Kong ◽  
Fan Hu
Keyword(s):  
Sustained Release ◽  
Powder Diffraction ◽  
Magnesium Stearate ◽  
Influential Factor ◽  
High Concentration ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Sustained Release Tablets ◽  
Crystal Transition ◽  
Excipient Compatibility

Background: Clarithromycin is widely used for infections of helicobacter pylori. Clarithromycin belongs to polymorphic drug. Crystalline state changes of clarithromycin in sustained release tablets were found. Objective: The aim of this study was to find the influential factor of the crystal transition of clarithromycin in preparation process of sustained-release tablets and to investigate the possible interactions between the clarithromycin and pharmaceutical excipients. Methods and Results: The crystal transition of active pharmaceuticals ingredients from form II to form I in portion in clarithromycin sustained release tablets were confirmed by x-ray powder diffraction. The techniques including differential scanning calorimetry and infrared spectroscopy, x-ray powder diffraction were used for assessing the compatibility between clarithromycin and several excipients as magnesium stearate, lactose, sodium carboxymethyl cellulose, polyvinyl-pyrrolidone K-30 and microcrystalline cellulose. All of these methods showed compatibilities between clarithromycin and the selected excipients. Alcohol prescription simulation was also done, which showed incompatibility between clarithromycin and concentration alcohol. Conclusion: It was confirmed that the reason for the incompatibility of clarithromycin with high concentration of alcohol was crystal transition.

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