Study of Compacting Methods for Nanostructured Thermoelectric Materials Based on Si-Ge and Half -Heusler Alloys

Recent methods of compacting nanopowders of thermoelectric materials of silicon germanium and Half-Heusler (HH) compounds based on Ni(Ti,Zr,Hf)Sn are presented. Half-Heusler alloys are known to be intermetallic compounds with quite large Seebeck coefficient and semiconducting transport properties. This makes them a potential candidate for thermoelectric applications. In this study we compare compacting methods applied to raw materials as a function of crystal structure. The results suggest that the thermal conductivity can be reduced by increasing the phonon scattering via nanostructuring. The effect of spark plasma sintering (SPS) and hot pressing on Gleeble system was analyzed by TEM and SEM methods. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3551

Thermoelectric Properties of Si-Ge Nanostructured Thermoelectric Materials Synthesized by Mechanical Alloying

Silicon-germanium alloys is one of the best thermoelectric materials in power generation devices operating in 600-1000 C range in heat conversion into electricity directly. The enhancement of efficiency comes mainly from a significant reduction in the thermal conductivity caused by the enhanced phonon scattering off the increased density of nanograin boundaries. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3551

Миграция знаний — основная тенденция в условиях экономической глобализации

In this article, the authors examine the concept of knowledge as part of the migration, changing social reality, which helps to distribute (transfer) knowledge all over the world in the shortest time. Social media and their credibility among users quickly turn into two powerful drivers of the knowledge economy, where the value is not material things (goods and products). The authors present their vision for the migration of knowledge in business and education, which could create additional value of such knowledge.Рассматривается понятие «миграция знаний» как составляющая часть экономики знания, в основе которой лежит тенденция к экономической, социальной, политической и культурной глобализацией современного мирового сообщества. Определены и описаны тенденции, которые происходят в экономике знаний в современных реалиях, показаны возможности использования новых каналов коммуникации, способных повлиять на эффективность образовательного учреждения и частного бизнеса. Авторы исследования делают вывод о том, что в условиях глобализации мирового сообщества важно не только находить новые подходы в работе со знанием, но и эффективно внедрять их в учебный процесс, а также в бизнес-процессы организации для того, чтобы повысить их экономическую конкурентоспособность

Dynamic behavior of HTSC opening switch models controlled by short over-critical current pulses

Dynamical properties of thin epitaxial film of YBa₂Cu₃O₇ HTSC-opening switch models under action of short overcritical current pulses were measured to test this method of control of fast (of nanosecond range) high-power opening switches for accelerator applications

The most recent (682-792 C.E.) volcanic eruption in the Jombolok lava field, East Sayan, Central Asia triggered exodus of Mongolian pre-Chinggis Khaan tribes (778-786 C.E.)

International audienceThis study presents new data on one of the most recent (historical) volcanic eruptions in Central Asia. The Jombolok lava field located in the East Sayan Mountains (Southern Siberia) was formed during Late Pleistocene and Holocene times. At least four phases of volcanic activity have been identified and evidences associated with the last phase have been found in the upper reaches of the Khi-Gol valley and in the Oka-Jombolok basin. The volcanic activity is represented by young basaltic lava located among older lavas. Live and dead trees have been sampled in the young lava field. Nine fragments of wood have been found embedded in lavas of the latest eruption. Dendrochronological analysis, radiocarbon dating and the analysis of historical chronicles have shown that the latest eruption occurred during the period 682-792 A.D. The volcanic activity possibly triggered the migration of Mongolian tribes out of the locality known in historical chronicles as Ergune-Kun towards the Onon River, which, 400 years later, became the place of birth and rise of Chinggis Khaan

Forming of precision thin-wall hollow electron beams for microwave generators

The electron gun producing the precision hollow relativistic electron beam for coherent microwave generator applications has been developed and tested. It is based on the large non-adiabatic compression of the beam emitted by ring-shaped cathode with an active surface big enough to produce a wanted current level. Further improvement of beam quality is possible by decreasing of the width of the annular emitter and increasing its emissive power

Ground-state level spin systems within Bernasconi model

The design problem for law autocorrelation binary sequences (LABS) is a notoriously difficult computational problem which is numbered as the problem number 005 in CSPLib. In statistical physics LABS problem can be interpreted as the energy of N interacting Ising spins. This is a Bernasconi model for a one N-dimensional chain of quantum particles. Ground-state level quantum system within the frame of Bernasconi model is binary sequence with lowest level of peak-sidelobes of aperiodic autocorrelation function. The new results of an exhaustive search for optimal binary sequences with minimum peak sidelobe up to length N=86 are demonstrated. The Bernasconi model exhibits features of a glass transition like a jump in the specific heat and slow dynamics and aging. The Bernasconi model the high temperature phase of Ising spin system reproduces exactly approximation

A method to measure the resonance transitions between the gravitationally bound quantum states of neutrons in the GRANIT spectrometer

We present a method to measure the resonance transitions between the gravitationally bound quantum states of neutrons in the GRANIT spectrometer. The purpose of GRANIT is to improve the accuracy of measurement of the quantum states parameters by several orders of magnitude, taking advantage of long storage of Ultracold neutrons at specula trajectories. The transitions could be excited using a periodic spatial variation of a magnetic field gradient. If the frequency of such a perturbation (in the frame of a moving neutron) coincides with a resonance frequency defined by the energy difference of two quantum states, the transition probability will sharply increase. The GRANIT experiment is motivated by searches for short-range interactions (in particular spin-dependent interactions), by studying the interaction of a quantum system with a gravitational field, by searches for extensions of the Standard model, by the unique possibility to check the equivalence principle for an object in a quantum state and by studying various quantum optics phenomena

Electron accelerator for energy up to 5.0 MeV and beam power up to 50 kW with Х-ray converter

The paper describes the industrial electron accelerator ILU-10 for electron energy up to 5 MeV and beam power up to 50 kW specially designed for use in industrial applications. The ILU-10 accelerator generates the vertical electron beam. The beam line turns the beam through an angle of 90° and transports the beam to the vertically posed Xray converter to generate the horizontal beam of X-rays.Приводиться опис прискорювача електронів ІЛУ-10 на енергію 5 МеВ потужністю 50 кВт, спеціально розробленого для таких комплексів. Для спрощення конструкції конвеєрної системи подачі оброблюваної продукції в зону опромінення використовується випускний пристрій з поворотом пучка на 90 градусів інаступною конвертацією електронного пучка в гамма-випромінювання на вертикально розташованій мішені.Приводится описание ускорителя электронов ИЛУ-10 на энергию 5 МэВ мощностью 50 кВт, специально разработанного для таких комплексов. Для упрощения конструкции конвейерной системы подачи обрабатываемой продукции в зону облучения используется выпускное устройство с поворотом пучка на 90 градусов и последующей конвертацией электронного пучка в гамма-излучение на вертикально расположенной мишени