Типологизация и анализ значимости рисков и угроз энергетической безопасности Республики Беларусь с учетом интеграции Белорусской АЭС в энергосистем

The article examines the most significant risks and threats to energy security in the conditions of integration of the Belarusian NPP into the energy system of the Republic of Belarus. The article also presents an analysis of existing methodological approaches to the assessment of energy security. The risk typology was carried out according to two criteria: the stages of the technological process and the sources of risks. As a result, production, financial and information risks (caused by information technologies) are highlighted. On the basis of an expert survey of specialists of republican unitary energy enterprises and of “Belenergo” State Production Association, a ranking of risks was carried out and the most significant of them were identified. It was determined that the most significant production risks are: depreciation of fixed assets; reduction in the utilization of own generating capacities and reliability of the generating equipment and network; outages that lead to disruption of the functioning of facilities for ensuring the vital activity of the population. The most important financial risks include: the increase in the cost of basic fuel and energy resources; shortage of working capital and investments; lack of sources of financing for the reconstruction of heating networks; reduction of consumer solvency; provision of discounts from tariffs to a significant number of business entities. According to respondents, among information risks the most important ones are the following: failures in the operation of informatization facilities that directly control the generating equipment of power plants, equipment of switchgears of power plants, equipment of substations; hacker cyberattacks; insufficient level of qualification of personnel, lack of interest of employees in the introduction of information technologies. The proposed threat identification and risk ranking at all stages of energy production can be used to develop measures to strengthen the country's energy security and assess their impact on socio-economic development of the Republic of Belarus. В статье исследованы наиболее значимые риски и угрозы энергетической безопасности в условиях интеграции Белорусской АЭС в энергосистему республики. Представлен анализ существующих методических подходов к оценке энергетической безопасности. Проведена типологизация рисков по двум критериям: стадиям технологического процесса и источникам рисков. В результате выделены риски производственные, финансовые и информационные (вызываемые информационными технологиями). На основе экспертного опроса специалистов РУП-облэнерго и ГПО «Белэнерго» осуществлено ранжирование рисков и выявлены наиболее значимые из них. При этом установлено, что самыми серьезными производственными рисками являются: износ основных средств; снижение загрузки собственных генерирующих мощностей и надежности работы генерирующего оборудования и сети; отключения, приводящие к нарушению функционирования объектов обеспечения жизнедеятельности населения. К наиболее важным финансовым рискам относятся: рост стоимости основных топливно-энергетических ресурсов; дефицит оборотных средств и инвестиций; отсутствие источников финансирования на реконструкцию тепловых сетей; снижение платежеспособности потребителей; предоставление значительному количеству субъектов хозяйствования скидок с тарифов. По мнению респондентов, существенное значение среди информационных рисков имеют: отказы или сбои в работе объектов информатизации, непосредственно управляющих генерирующим оборудованием электростанций, оборудованием распределительных устройств электростанций, оборудованием подстанций; хакерские кибератаки; недостаточный уровень квалификации персонала, отсутствие заинтересованности сотрудников во внедрении информационных технологий. Предлагаемые идентификация угроз и ранжирование рисков на всех этапах энергетического производства могут использоваться для разработки мероприятий по укреплению энергобезопасности страны и оценки их влияния на социально-экономическое развитие

Модифицирование литейных алюминиевых сплавов системы Al–Mg–Si обработкой жидкой фазы наносекундными электромагнитными импульсами

The AA 511 alloy of the Al–Mg–Si system was used as an example to demonstrate that aluminum melt irradiation with nanosecond electromagnetic pulses (NEPs) leads to a significant change in the nature of structure formation during crystallization. It was found that an increase in the frequency of melt irradiation with NEPs is accompanied by the refinement of the alloy structural components, while the greatest grain size reduction of the α-solid solution and intergranular inclusions of the eutectic Mg2Si phase is observed at a NEPs frequency f = 1000 Hz. An increase in the NEPs frequency leads to a significant increase in the concentration of magnesium in the α-solid solution and the fragmentation of Mg2Si phase intergranular inclusions, which is released in the form of compact isolated inclusions when the melt is irradiated at a frequency of 1000 Hz. It was shown that melt processing with NEPs leads to an increase in the Brinell hardness of as-cast specimens, as well as to a significant increase in the microhardness of α-solid solution grains (from 38.21 HV in the initial state to 61.85 HV after irradiation with a frequency of 1000 Hz). It was assumed that the effect of a pulsed electromagnetic field leads to a decrease in the critical values of the Gibbs free energy required to initiate nucleation processes, and to a decrease in the surface tension at the «growing crystal – molten metal» interface, which causes a modifying effect on the alloy structure due to a decrease in the critical size of crystal nuclei.На примере сплава АА 511 системы Al–Mg–Si показано, что облучение алюминиевых расплавов наносекундными электромагнитными импульсами (НЭМИ) приводит к существенному изменению характера структурообразования при кристаллизации. Установлено, что повышение частоты облучения расплавов НЭМИ сопровождается измельчением структурных составляющих сплава и перераспределением в них легирующих элементов. При этом наибольшая степень уменьшения размеров зерен α-твердого раствора и межзеренных включений эвтектической фазы Mg2Si наблюдается при частоте НЭМИ f = 1000 Гц. Повышение частоты НЭМИ приводит к значительному увеличению концентрации магния в α-твердом растворе и фрагментации межзеренных включений фазы Mg2Si, которая при облучении расплава с f = 1000 Гц выделяется в форме компактных изолированных включений. Показано, что обработка расплавов НЭМИ приводит к повышению твердости (по Бринеллю) образцов в литом состоянии, а также к увеличению микротвердости зерен α-твердого раствора (с 38,21 HV в исходном состоянии до 61,85 HV после облучения с частотой 1000 Гц). Было сделано предположение, что воздействие импульсного электромагнитного поля приводит к понижению критических значений свободной энергии Гиббса, необходимых для инициации процессов зародышеобразования, и снижению поверхностного натяжения на границах раздела «растущий кристалл – металлический расплав», что обусловливает модифицирующее воздействие на структуру сплава за счет уменьшения критического размера зародышей кристаллизации

A programmed cell death pathway in the malaria parasite Plasmodium falciparum has general features of mammalian apoptosis but is mediated by clan CA cysteine proteases

Several recent discoveries of the hallmark features of programmed cell death (PCD) in Plasmodium falciparum have presented the possibility of revealing novel targets for antimalarial therapy. Using a combination of cell-based assays, flow cytometry and fluorescence microscopy, we detected features including mitochondrial dysregulation, activation of cysteine proteases and in situ DNA fragmentation in parasites induced with chloroquine (CQ) and staurosporine (ST). The use of the pan-caspase inhibitor, z-Val-Ala-Asp-fmk (zVAD), and the mitochondria outer membrane permeabilization (MOMP) inhibitor, 4-hydroxy-tamoxifen, enabled the characterization of a novel CQ-induced pathway linking cysteine protease activation to downstream mitochondrial dysregulation, amplified protease activity and DNA fragmentation. The PCD features were observed only at high (μM) concentrations of CQ. The use of a new synthetic coumarin-labeled chloroquine (CM-CQ) showed that these features may be associated with concentration-dependent differences in drug localization. By further using cysteine protease inhibitors z-Asp-Glu-Val-Asp-fmk (zDEVD), z-Phe-Ala-fmk (zFA), z-Phe-Phe-fmk (zFF), z-Leu-Leu-Leu-fmk (zLLL), E64d and CA-074, we were able to implicate clan CA cysteine proteases in CQ-mediated PCD. Finally, CQ induction of two CQ-resistant parasite strains, 7G8 and K1, reveals the existence of PCD features in these parasites, the extent of which was less than 3D7. The use of the chemoreversal agent verapamil implicates the parasite digestive vacuole in mediating CQ-induced PCD

Current infestation status of Atlantic salmon with Anisakis simplex larvae in the River Ponoi (the Murmansk region)

The infestation of Atlantic salmon with larvae of nematode Anisakis simplex has been studied in recreational catches in the River Ponoi of the Murmansk Region by using data from field research. The level and dynamics of infestation of autumn Atlantic salmon in 2009–2016 have been determined in comparison with the historical data. The results of research have shown that the proportion of salmon infested with parasite (extensiveness of infestation) varied from 2,1 to 59,8 % and a number of parasites in a single fish (intensity of infestation) – from 0–1 to 0–28. Indexes of infestation have varied also among different groups of autumn salmon but related neither with a number of years salmon spent at sea nor with salmon run timing into the river. The Red Vent Syndrome (RVS) has never been confirmed for Ponoi Atlantic salmon. The larvae of nematode have been found only in the mesentery and on the internal organs of the abdominal cavity of salmon and never in the muscles. Observations of the behavior of parasite larvae found in the abdominal cavity of the salmon have shown that when storing unbetted fish during the day at different ambient temperatures, migration of larvae to muscle tissue has not been observed. These findings have an important practical application as larvae of nematode Anisakis simplex are infective to humans and cause Anisakidosis. After having analyzed the data on dynamics of salmon infestation the assumption has been made that the level of Atlantic salmon infestation with Anisakis simplex larvae depends mostly on the role of different salmon food species in the parasite life cycle and their availability in different years of salmon feeding migration in ocean

Influence of Flux Composition on Hy-drogen Content in Aluminum Melts

The paper is aimed at evaluating the quality and performance characteristics of industrial fluxes, which are intended for refining processing of aluminum melts and used in production conditions of RUSAL JSC (Russian Federation). The results of the work were obtained using X-ray diffraction and thermogravimetric analyzes, as well as standardized procedures for determining the hydrogen content in metallic melts. It is shown that fluxes containing crystalline hydrates and hygroscopic water can be a source of saturation of aluminum melt with dissolved hydrogen. The mechanism of dehydration of crystalline hydrates in the composition of fluxes is given. According to the results of the research, technical solutions aimed at reducing hydrogen saturation of aluminum melt during flux processing are proposed

Crystallization Behavior and Properties of Hypereutectic Al-Si Alloys with Different Iron Content

Understanding the influence of iron impurity on the formation of the structure and the properties of hypereutectic aluminum-silicon alloys are important for achieving the required quality of castings, especially those obtained from secondary materials. In the present work, the influence of different iron contents (0.3, 1.1, and 2.0 wt.%) on the crystallization process, microstructure and mechanical properties of the Al-15% Si alloy was studied. It is shown that the presence of iron impurity in the Al-15% Si alloy leads to increasing the eutectic crystallization time from 6.2 to 7.6 s at increasing the iron content from 0.3 wt.% to 1.1 wt.%, changing the structure of the alloy eutectic in the solid state. The primary silicon and β-Al5SiFe phase coexist in the structure of the Al-15% Si alloys at a temperature below 575°C in the range of iron concentrations from 0 to 2 wt.% in equilibrium conditions. In the experimental alloys structure, the primary crystals of the β-phase were metallographically detected only in the alloys containing 1.1 and 2 wt.% of iron impurity. Increase of the iron content up to 2 wt.% significantly reduces the mechanical properties of the Al-15% Si alloy due to the formation of large platelet-like inclusions of β-Al5SiFe phase

INFLUENCE OF ATOMIC AND MOLECULAR HYDROGEN IN SILUMINS MELTS ON THEIR MECHANICAL PROPERTIES

We study the influence of gas porosity caused by the presence of dissolved hydrogen on the mechanical properties of Al–Si alloys. The results are obtained by testing cast samples with identical contents of hydrogen and a given (atomic or molecular) form of hydrogen inclusions. The dependence of the me-chanical properties of alloys on the density index is statistically established. It is shown that if the densi-ty index increases and hydrogen is released in the atomic form, the mechanical properties remain practi-cally unchanged, whereas the presence of hydrogen in the molecular form in silumin deteriorates the mechanical properties of the meta