33 research outputs found
Nonstandard analysis in electrical engineering. The analysis of the direct current circles with ideal reactive elements
The article proposes the use of ideas and methods of non-standard analysis in the field of theoretical electronics. The article shows that the analysis of DC circuits, including ideal inductances and capacitances, by standard methods of theoretical electrical engineering is too complicated or almost impossible. To solve this problem, it is proposed to extend the methods of non-standard analysis by the tasks of analyzing electrical circuits with ideal reactive elements. The authors have defined a class of non-standard electrotechnical problems aimed at the analysis of DC electrical circuits, including ideal reactive elements — ideal inductances and capacitances. It is shown that the solution of the selected class of problems by standard methods of theoretical electrical engineering is too difficult or almost impossible. It is proposed to extend the methods of non-standard analysis by the tasks of analyzing electrical circuits with ideal reactive elements. The obtained advantages of this approach are confirmed by examples of calculations of electrical circuits with inductances and capacitances, as well as magnetic circuits
Non-standard analysis in electrical engineering. Transient analysis in second-order electrical circuits with violation of switching laws
For the first time, the authors proposed the use of the mathematical apparatus of non-standard analysis to solve certain non-trivial problems of theoretical electrical engineering. It was established that the axiomatics of non-standard analysis allows to simplify the analysis of transient processes in high-order electric circuits when the switching laws are violated. It is shown that the application of non-standard analysis methods in theoretical electrical engineering provides an opportunity to use the traditional classical method of transient processes analysis of circuits with violation of switching laws. Only by using methods of non-standard analysis, it is possible to strictly prove the fulfillment of the law of energy conservation in such schemes. Also, examples of solving such tasks are given. It is recommended to expand the scope of application of non-standard methods of analysis in problems of various branches of science and technology, which use differential calculus and boundary transitions, and the solution of which is limited or impossible by standard approaches
Development of the fuzzy sets theory: weak operations and extension principles
The paper considers the problems that arise when using the theory of fuzzy sets to solve applied problems. Unlike stochastic methods, which are based on statistical data, fuzzy set theory methods make sense to apply when statistical data are not available. In these cases, algorithms should be based on membership functions formed by experts who are specialists in this field of knowledge. Ideally, complete information about membership functions is required, but this is an impractical procedure. More often than not, even the most experienced expert can determine only their carriers or separate sets of the α -cuts for unknown fuzzy parameters of the system. Building complete membership functions of unknown fuzzy parameters on this basis is risky and unreliable. Therefore, the paper proposes an extension of the fuzzy sets theory axiomatics in order to introduce non-traditional (less demanding on the completeness of data on membership functions) extension principles and operations on fuzzy sets. The so-called α -weak operations on fuzzy sets are proposed, which are based on the use of separate sets of the α -cuts. It is also shown that all classical theorems of Cantor sets theory apply in the extended axiomatic theory. New extension principles of generalization have been introduced, which allow solving problems in conditions of significant uncertainty of information
Development of the fuzzy sets theory: weak operations and extension principles
The paper considers the problems that arise when using the theory of fuzzy sets to solve applied problems. Unlike stochastic methods, which are based on statistical data, fuzzy set theory methods make sense to apply when statistical data are not available. In these cases, algorithms should be based on membership functions formed by experts who are specialists in this field of knowledge. Ideally, complete information about membership functions is required, but this is an impractical procedure. More often than not, even the most experienced expert can determine only their carriers or separate sets of the α-cuts for unknown fuzzy parameters of the system. Building complete membership functions of unknown fuzzy parameters on this basis is risky and unreliable. Therefore, the paper proposes an extension of the fuzzy sets theory axiomatics in order to introduce non-traditional (less demanding on the completeness of data on membership functions) extension principles and operations on fuzzy sets. The so-called α-weak operations on fuzzy sets are proposed, which are based on the use of separate sets of the α-cuts. It is also shown that all classical theorems of Cantor sets theory apply in the extended axiomatic theory. New extension principles of generalization have been introduced, which allow solving problems in conditions of significant uncertainty of information
The Role of Red Yeast Rice Based Preparations for Non-Pharmacological Correction of Dyslipidemia in Patients with Low and Moderate Cardiovascular Risk (Expert Opinion)
The Russian Federation is among countries with high cardiovascular risk. Hypercholesterolemia is a leading risk factor for the development of atherosclerotic cardiovascular diseases. To achieve low-density lipoprotein cholesterol (LDL-C) targets, such approaches as lifestyle changes and pharmacological correction, based on the use of statins, are applied. At the same time, a significant proportion of the population has moderate hypercholesterolemia and is characterized by low or moderate cardiovascular risk. Although first-line recommendations should be followed, a healthy lifestyle alone is not enough to achieve target levels of LDL-C, which means that even people with low to moderate risk may end up with the prospect of lifelong therapy with lipid-lowering drugs. These individuals do not have an indication for lipid-lowering therapy, and they are usually recommended a change in diet and supplementation. Innovative nutritional strategies have been developed to manage dyslipidemia. They were based either on changing some "risky" food components or on encouraging the consumption of "healthy" functional foods and/or nutraceuticals. Nutraceuticals (registered as food supplements in Russia) is an innovative way to help control LDL-C at low and moderate risk individuals without lipid-lowering drugs and as nutritive support for the cholesterol-lowering diet. Red yeast rice (RYR) based preparations have been already developed and available at the moment. RYR based preparations can be considered in patients with low and moderate cardiovascular risk, who have not reached the target level of LDL-C and have no indications for statin therapy or have statin intolerance. RYR based preparations contains a statin-like substance monacolin K in a dose of 3 mg. In randomized clinical trials, it was proved that the use of high-quality RYR nutraceutical leads to a decrease in LDL-C by an average of 20% without increasing the risk of side effects like for statins. Evaluation of dietary supplements and functional foods should necessarily include not only evidence of beneficial effects with respect to effects on the lipid profile and atherosclerosis, but also proven good tolerability. The manufacturing standard for these products is also important, guaranteeing component standardization and quality. RYR analogues should guarantee the absence of mycotoxin in their composition. In Russia, programs are needed for the primary prevention of atherosclerotic cardiovascular diseases with effects on hypercholesterolemia at the population level
CLINICAL GUIDELINES FOR FAMILIAL HYPERCHOLESTEROLEMIA
These guidelines represent all current aspects of etiology, diagnosis, and treatment of the clinical and statistical group of familial hypercholesterolemia in both adults and children in accordance with the requirements of the Ministry of Health of Russia
Моделирование процесса смешения теплоносителя в опускном участке и напорной камере смешения ВВЭР-1200 (В-491)
The most representative accident scenario is determined and a physical and mathematical model is developed for studying the mixing of non-isothermal coolant flows in the structural elements of the V-491 reactor facility (VVER-1200), in which the motion of the medium is described in a three-dimensional non-stationary formulation. Based on the analytical estimates of the list of initiating events, a scenario was chosen with the connection of an idle loop of the main circulation pipeline to three operating ones without a preliminary power reduction. A computational algorithm and a numerical method have been developed for the computational analysis of the selected accident scenario and the justification of the safety of operation of the V-491 reactor facility (VVER-1200). During the numerical simulation, the RANS method was used, which consists in solving the Reynolds-averaged Navier–Stokes equations, the continuity equation and the energy equation. The SST k–ω model of turbulence by Florian Menter is used to close the equations. The verification of the developed physical and mathematical model and calculation procedure was carried out by modeling thermohydraulic processes in models with both a relatively simple geometric design (tee connection) and in a scale model of the reactor vessel (ROCOM experiment), including a lowering section and a pressure mixing chamber. The qualitative agreement of the numerical simulation results with the available data of physical experiments is shown. The results of numerical simulation of the mixing process of non-isothermal coolant flows in the section from the branch pipe of the “cold” thread of the main circulation pipeline to the lower boundary of the fuel of the VVER-1200 core (V-491) are presented. It is shown that the heterogeneity in the temperature distribution at the entrance to the core manifests itself up to 15.5 s of the calculated accident scenario. For calculations the following code coupling were used: Ansys Fluent/Rainbow-TPP.Определен наиболее представительный аварийный сценарий и разработана физико-математическая модель для исследования смешения неизотермических потоков теплоносителя в конструктивных элементах реакторной установки В-491 (ВВЭР-1200), в которой движение среды описывается в трехмерной нестационарной постановке. Исходя из аналитических оценок перечня исходных событий, выбран сценарий с подключением неработающей петли главного циркуляционного трубопровода к трем работающим без предварительного снижения мощности. Разработаны расчетная методика и численный метод для анализа выбранного аварийного сценария и обоснования безопасности эксплуатации реакторной установки В-491 (ВВЭР-1200). При проведении численного моделирования использован метод RANS, заключающийся в решении осредненных по Рейнольдсу уравнений Навье–Стокса, уравнения неразрывности и уравнения энергии. Для замыкания уравнений использована SST k–ω модель турбулентности Флориана Ментера. Проведена верификация разработанной физико-математической модели и процедуры расчета посредством моделирования теплогидравлических процессов в моделях как с относительно простой геометрической конструкцией (тройниковое соединение), так и в масштабной модели корпуса реактора (эксперимент ROCOM), включающего опускной участок и напорную камеру смешения. Показано качественное согласование численных результатов моделирования с доступными данными физических экспериментов. Представлены результаты численного моделирования процесса смешения неизотермических потоков теплоносителя на участке от патрубка «холодной» нитки главного циркуляционного трубопровода до нижней границы топлива активной зоны ВВЭР-1200 (В-491). Показано, что неоднородность в распределении температуры на входе в активную зону проявляется до 15,5 с расчетного аварийного сценария. При выполнении вычислений использовалась связка специализированных расчетных средств Ansys Fluent/Rainbow-TPP
Популяционный иммунитет к SARS-COV-2 населения Калиниградской области в эпидемический сезон COVID-19
Introduction. The COVID-19 pandemic was announced by WHO in February 2020. In the Kaliningrad region, the first case (imported) was registered in early March 2020, the beginning of the epidemic increase fell on the 14th week. 2020, and the peak incidence was reached in the 22nd week of the year, after which there was a steady decrease in the number of cases. The study of population immunity was carried out at the 32nd week during the period of the lowest level of intensity of the epidemic process.Purpose of the study. Assessment of the assessment of the level of population immunity to the SARS-CoV-2 virus among the population of the Kaliningrad region during the period of the epidemic incidence of the population of COVID-19.Materials and methods. The study was carried out as part of the first stage of the Rospotrebnadzor program to assess population immunity to SARS-CoV-2 among the population of the Russian Federation. The selection of volunteers for the study was carried out by a questionnaire survey and subsequent randomization. The analysis includes the results of a survey of 2675 people. The number of volunteers in age groups ranged from 314 to 493 people. The results obtained were processed by the methods of variation statistics.Results. The results obtained showed that the average seroprevalence in the population was 50.2%, while the highest seroprevalence was found in the child age group 1-17 years (66.9%) and among persons aged 18-29 (57.0). No significant gender differences were found (men – 48,3 ± 1,6%, women – 51,1 ± 1,1%). The distribution of the proportion of seropositive people in the settlements of the region varied from 33,9% to 59.6%. The largest share of seroprevalence in the representative samples was found among people engaged in art / creativity (55,3%), the smallest – among educational workers (42,0%). Among COVID-19 convalescents, the level of humoral immunity reached 94,6%. Most of the seropositive volunteers (95,2%) did not have any symptoms of COVID-19, that is, they belonged to the category of asymptomatic carriers.Output. The results of a survey of a representative cohort of volunteers in the Kaliningrad region showed that they are characterized by a high level of population immunity, which makes it possible to expect a decrease in.Введение. Пандемия COVID-19 была объявлена Всемирная организация здравоохранения в феврале 2020 г. В Калининградской области первый случай (завозной) зарегистрировали в начале марта 2020 г., начало эпидемического нарастания пришлось на 14-ю неделю 2020 г., а пик заболеваемости был достигнут на 22-й неделе года, после чего отмечалось устойчивое снижение количества заболевший. Исследование популяционного иммунитета было проведено на 32-й неделе в период самого низкого уровня напряженности эпидемического процесса.Цель. Оценка уровня популяционного иммунитета к вирусу SARS-CoV-2 среди населения Калининградской области в период эпидемической заболеваемости населения COVID-19.Материалы и методы. Исследование проведено в рамках первого этапа программы Роспотребнадзора по оценке популяционного иммунитета к SARS-CoV-2 среди населения Российской Федерации. Отбор волонтеров для исследования проводили методом анкетирования и последующей рандомизации. В анализ включены результаты обследования 2675 человек. Количество волонтеров в возрастных группах варьировало от 314 до 493 человек. Полученные результаты обрабатывали методами вариационной статистики.Результаты. Полученные результаты показали, что средняя серопревалентность по популяции составила 50,2%, при этом набольшая серопревалентность была выявлена в детской возрастной группе 1–17 лет (66,9%) и среди лиц в возрасте 18–29 лет (57,0). Достоверных половых различий не установлено (мужчины – 48,3±1,6%, женщины – 51,1±1,1%). Распределение доли серопозитивных по населенным пунктам области варьировало от 33,9% до 59,6%. Наибольшая доля серопревалентных в репрезентативных выборках выявлена среди лиц, занятых искусством/творчеством (55,3%), наименьшая – среди работников образования (42,0%). Среди реконвалесцентов COVID-19 уровень гуморального иммунитета достиг 94,6%. Большая часть серопозитивных волонтеров (95,2%) не имела каких-либо симптомов COVID-19, то есть относилась к категории бессимптомных носителей.Выводы. Результаты обследования репрезентативной когорты волонтеров Калининградской области показали, что для них характерен высокий уровень популяционного иммунитета, позволяющий ожидать снижения напряженности эпидемического процесса.
Ezetimibe potential in cardiology practice
Vascular wall infiltration with lipoproteins, in particular with low-density lipoprotein (LDL) cholesterol (LDLCH), plays an important role in atherosclerosis pathogenesis. Elevated LDL-CH levels are associated with increased risk of coronary heart disease (CHD). Based on the evidence from experimental and clinical studies, there is a direct link between LDL-CH reduction and decreased incidence of cardiovascular events. Statins are medications of choice for LDL-CH reduction; however, statin monotherapy does not always result in target LDLCH level achievement, due to pharmaco-genetic factors and adverse effects of the therapeutically effective statin doses. In these clinical situations, a combination of low-dose statins with other lipid-lowering agents is effective. Recently, high effectiveness of statin combination with ezetimibe (inhibitor of intestine CH absorption) has been demonstrated. It is explained by targeting both mechanisms which determine blood CH levels (intestine absorption and hepatic synthesis), with a substantial reduction in LDL-CH levels as a result