Расчет гидродинамики потока в электроциклоне

To analyze the elektrocyclone flow hydrodynamic computer calculation using the finite element method (FEM) is applied. The geometry of the model corresponds to the laboratory  elektrocyclone. k-ε-turbulence model is used for the computation. The system of equations is solved by SIMPLE algorithm. The calculation results give a pattern of the flow velocity distribution and flow lines in different sections. There is conclusion based on the results about elektrocyclone flow hydrodynamic.Для анализа гидродинамики потока в электроциклоне применен компьютерный расчет с использованием метода конечных элементов (МКЭ). Геометрия модели соответствует лабораторному электроциклону. Для расчетов использована k-ε-модель турбулентности. Система уравнений решается с помощью алгоритма SIMPLE. Результаты расчета дают картину распределения скоростей потока и линий тока в различных сечениях. На основании результатов делается вывод о гидродинамике электроциклона. Выявлен факт, что в бункере электроциклона отсутствует вихревое движение, также нет развитого течения в области стенок, а ниже выхлопного отверстия скорость потока близка к 0. Это благоприятно сказывается на эффективности очистки, т. к. выходящий чистый газ не увлекает с собой осевшие частицы. Выводы: 1) гидродинамика электроциклона может быть описана с помощью математической модели и рассчитана с помощью МКЭ; 2) поток в электроциклоне, как и ожидалось, имеет закрученную структуру, угол закрутки зависит от длины активной зоны; 3) конструкция бункера обеспечивает выход очищенного газа без вовлечения в него уловленных частиц

Phonon Hall effect in ionic crystals in the presence of static magnetic field

We study phonon Hall effect (PHE) for ionic crystals in the presence of static magnetic field. Using Green-Kubo formula, we present an exact calculation of thermal conductivity tensor by considering both positive and negative frequency phonons. Numerical results are shown for some lattices such as hexagonal lattices, triangular lattices, and square lattices. We find that the PHE occurs on the nonmagnetic ionic crystal NaCl, although the magnitude is very small which is due to the tiny charge-to-mass ratio of the ions. The off-diagonal thermal conductivity is finite for nonzero magnetic field and changes sign for high value of magnetic field at high temperature. We also found that the off-diagonal thermal conductivity diverges as $\pm{1/T}$ at low temperature

Metal-insulator transition in manganites: mixture of oxygen isotopes versus magnetic field

We have investigated the effect of oxygen isotope substitution on the metal-insulator transition temperature and the resistivity of the narrow band manganite (La0.25Pr0.75)0.7Ca0.3MnO3 in a constant magnetic field. A set of 16 samples having different mixtures of 16O, 17O and 18O isotopes with average mass varying from 16.0 to 17.8 a.m.u. was studied. We have found that the magnetoresistance and the isotope effect can be linked together with a single parameter - effective magnetic field, which decreases linearly with an increase of average oxygen mass with a slope of -2 T/a.m.u. The applicability of the small polaron model is discussed.Comment: Submitted to Moscow International Symposium on Magnetism MISM'0

Thermal Properties of Graphene, Carbon Nanotubes and Nanostructured Carbon Materials

Recent years witnessed a rapid growth of interest of scientific and engineering communities to thermal properties of materials. Carbon allotropes and derivatives occupy a unique place in terms of their ability to conduct heat. The room-temperature thermal conductivity of carbon materials span an extraordinary large range - of over five orders of magnitude - from the lowest in amorphous carbons to the highest in graphene and carbon nanotubes. I review thermal and thermoelectric properties of carbon materials focusing on recent results for graphene, carbon nanotubes and nanostructured carbon materials with different degrees of disorder. A special attention is given to the unusual size dependence of heat conduction in two-dimensional crystals and, specifically, in graphene. I also describe prospects of applications of graphene and carbon materials for thermal management of electronics.Comment: Review Paper; 37 manuscript pages; 4 figures and 2 boxe

The role of leptin in the respiratory system: an overview

Since its cloning in 1994, leptin has emerged in the literature as a pleiotropic hormone whose actions extend from immune system homeostasis to reproduction and angiogenesis. Recent investigations have identified the lung as a leptin responsive and producing organ, while extensive research has been published concerning the role of leptin in the respiratory system. Animal studies have provided evidence indicating that leptin is a stimulant of ventilation, whereas researchers have proposed an important role for leptin in lung maturation and development. Studies further suggest a significant impact of leptin on specific respiratory diseases, including obstructive sleep apnoea-hypopnoea syndrome, asthma, COPD and lung cancer. However, as new investigations are under way, the picture is becoming more complex. The scope of this review is to decode the existing data concerning the actions of leptin in the lung and provide a detailed description of leptin's involvement in the most common disorders of the respiratory system

Intellectual Property Management. Master’s program. "High-Technology Business Management" : [study guide : метод. указания]. - Текст : электронный

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