Radar-absorbent properties of a foam glass with gallium arsenide addition

The principal possibility of using wastes of semiconductor devices production containing gallium arsenide as a component of radio-absorbing material was established. The composition formulation including perlite, liquid glass, complex blowing agent and waste is developed. It is shown that with increase the waste amount in the composition from 10 to 30 wt. % the absorption coefficient increases from 80 to 98%, the transmission coefficient decreases to zero. The obtained results indicate a high absorbing capacity of composite in the frequency range of 120 - 260 GHz that refers to ultrasonic waves

Усовершенствование механизмов обеспечения производственной безопасности при бурении скважин

Объектом исследования является производственная безопасность при бурении скважин. Цель работы – усовершенствование механизмов обеспечения производственной безопасности при бурении скважин. Предмет исследования – механизмы обеспечения производственной безопасности при бурении скважин. В процессе исследования были изучены общие требования безопасности на объектах бурения, рассматривалась система производственной безопасности в ООО "СГК-Бурение", был проведен анализ состояния несчастных случаев при бурении скважин (по состоянию с 2014 по 2018 гг.) и выявлены основные их причины. Были раскрыты механизмы обеспечения производственной безопасности на объектах бурения.The object of the study is production safety when drilling wells. The purpose of the work is to improve the mechanisms of ensuring production safety while drilling wells. The subject of the study is the mechanisms for ensuring production safety while drilling wells. In the course of the study, general safety requirements for drilling sites were studied, the production safety system at LLC "SGC-Burenie" was considered, an analysis of the state of accidents during drilling of wells (as from 2014 to 2018) was carried out and their main causes were identified. The mechanisms for ensuring production safety at drilling facilities were disclosed

The analysis and mathematical modelling of continuous permanent magnets magnetic fields of magnetostrictive converters of movement

В работе подробно рассмотрен анализ основных факторов, влияющих на формирование магнитных полей магнитострикционных преобразователей перемещения при использовании в них сплошного постоянного магнита. Выполнен анализ влияния каждого фактора. Исследованы расчетные формулы напряженности магнитных полей, созданных сплошным постоянным магнитом

Diabetes mellitus and the metabolic syndrome do not abolish, but might reduce, the cardioprotective effect of ischemic postconditioning

ObjectiveIschemic preconditioning fails to protect the diabetic heart against lethal reperfusion injury. Because the pathways of ischemic pre- and postconditioning partially overlap, we evaluated the cardioprotective effect of ischemic postconditioning in mouse models of type 2 diabetes (ObOb) and the metabolic syndrome (DKO).MethodsMice (C57BL/6J, ObOb, and DKO; aged 24 weeks; n = 24, n = 28, and n = 18, respectively) underwent reperfusion after 30 minutes of coronary occlusion with or without ischemic postconditioning (3 cycles of 10 seconds reperfusion–reocclusion). Left ventricular contractility and infarct size were assessed 60 minutes later with pressure conductance analysis and 2,3,5-triphenyl-tetrazolium chloride staining, respectively. In a second cohort (C57BL/6J and DKO; aged 12 weeks; n = 31 and n = 24, respectively) cardiac cine magnetic resonance imaging was performed after 1 and 10 weeks, followed by pressure conductance analysis and Sirius red staining.ResultsIn the C57BL6/J mice, the infarct size was lower (40%, P < 10−5) and the load independent preload recruitable stroke work was greater after ischemic postconditioning (P < .05). In the ObOb and DKO mice, ischemic postconditioning reduced the infarct size by 24% (P < 10−5). In the C57BL/6J mice, the ejection fraction was greater and the myocardial mass was lower 10 weeks after ischemic postconditioning (P < .05). Tagging grid deformation was increased after ischemic postconditioning in both infarcted and remote areas. After ischemic postconditioning, the survival and ejection fraction were greater in the DKO mice (67% vs 17% and 44% ± 11% vs 59% ± 2%, P < .05 for both), and the collagen content was lower for both C57BL/6J and DKO mice (P < .05 for both).ConclusionsThe cardioprotective effect of ischemic postconditioning was sustained in C57BL/6J mice after 10 weeks and protected against adverse left ventricular remodeling. In mouse models of type 2 diabetes, protection against lethal reperfusion injury is present, leading to increased survival after ischemia and reperfusion

Проектирование релейной защиты линии электропередачи 220 кВ ПС «Крохалевская» – ПС «Ново-Анжерская» Кузбасской ЭЭС

Выпускная квалификационная работа содержит 93 страницы, 12 рисунков, 15 таблиц, 30 источников, 3 приложения. Ключевые слова: Дистанционная защита, токовая защита нулевой последовательности, максимальная токовая защита, релейная защита, линия электропередач. Объектом разработки является релейная защита линии электропередач. Цель работы – выбор и расчет уставок срабатывания релейной защиты линии электропередач. В процессе работы проводились замеры электрических величин с помощью программно-вычислительного комплекса и расчеты необходимых параметров по соответствующим выражениям. Полученными результатами являются значения уставок срабатывания и коэффициентов чувствительности. Область применения: непосредственная установка защит и задание ее параметров.Final qualifying work consists of 93 pages, 12 figures, 15 tables, 30 sources, 3 application. Keywords: distance protection, current protection of zero sequence, overcurrent protection, relay protection, power line. The object is the development of relay protection of power lines. Purpose – the choice and calculation of settings of actuation of relay protection of power lines. In the process the work was carried out measurements of electrical quantities using the software-computing complex calculations and the necessary parameters on the relevant terms. The results obtained are set values of the response and sensitivity coefficients. Application scope: direct installation of protections and setting its parameters

Synthesis and characterization of Al-Mg powder materials

In this paper presents the results of studies of Al-Mg alloy depending on the time of mechanical activation in a planetary mill. It is shown that the increase in mechanical activation time more than 7 hours leads to the appearance of agglomerates of powder particles