Determination of Inactive Powers in a Single-Phase AC Network

Based on the development of the theory of reactive power and distortion power, starting with the works of Fryze and Budeanu, it has been found that the contradictions in the definition of the components of inactive powers are caused by errors in the introduced intermediate concepts and corresponding calculations when switching to nonlinear and non-sinusoidal AC circuits. The materials of the works of modern researchers and the numerical calculations carried out made it possible to trace the differences between reactive power and distortion power, to confirm the orthogonality properties of the active, reactive power, and distortion power components. The paper defines the conditions for achieving a power balance in an AC network with nonlinear loads, compiled and tested criteria leading to the absence of distortion power in a single-phase AC network. Using the time base of the projection of the generalized vectors in vector diagrams, it is shown that compliance with the criteria for the absence of distortion power does not determine the mutual similarity of the voltage curve with the current curve for a nonlinear load. It has been found that the well-known term “distortion power” has an unfortunate wording, since this power, although it characterizes the interaction of harmonics of currents and voltages with different ordinal numbers, is not determined by the visual similarity or the degree of distortion of the load current waveforms relative to the supply voltage curve

Degradation of Lithium-Ion Batteries in an Electric Transport Complex

The article provides an overview and comparative analysis of various types of batteries, including the most modern type-lithium-ion batteries. Currently, lithium-ion batteries (LIB) are widely used in electrical complexes and systems, including as a traction battery for electric vehicles. Increasing the service life of the storage devices used today is an important scientific and technical problem due to their rapid wear and tear and high cost. This article discusses the main approaches and methods for researching the LIB resource. First of all, a detailed analysis of the causes of degradation was carried out and the processes occurring in lithium-ion batteries during charging, discharging, resting and difficult operating conditions were established. Then, the main factors influencing the service life are determined: charging and discharging currents, self-discharge current, temperature, number of cycles, discharge depth, operating range of charge level, etc. when simulating a real motion process. The work considers the battery management systems (BMS) that take into account and compensate for the influence of the factors considered. In the conclusion, the positive and negative characteristics of the presented methods of scientific research of the residual life of LIB are given and recommendations are given for the choice of practical solutions to engineers and designers of batteries. The work also analyzed various operating cycles of electric transport, including heavy forced modes, extreme operating modes (when the amount of discharge and discharge of batteries is greater than the nominal value) and their effect on the degradation of lithium-ion batteries

Mental hygiene of interpersonal relations of student-managers in a megapolis

The article presents a psychological analysis of the behavior features and interpersonal relations of students-managers in a metropolis. The relevance of the present work is determined by the fact that for young people, higher education is associated with a change in their social status when they move from direct dependence on their parents to independent actions and active life in a big city. The specifics of the urban space of a metropolis have a strong influence on their mental state and understanding of the world around them. The popularity of the manager’s profession among young people entering universities has also contributed to the relevance of the study. Young people set themselves the goal of “learning to manage and lead.” The conditions of the big city impose special requirements on future managers, focusing them on the implementation of adaptive psychological functions. The manager’s ability to conform to social attitudes, to create a pleasant impression for others becomes for him a professionally important quality. As a result, students face a paradoxical situation involving a system of “double standards”. In this regard, they encounter difficulties in social adaptation and the formation of stable interpersonal relationships. To solve this problem, an empirical study was conducted, which allowed determining the values of the main strategies of interpersonal relations based on a comparative analysis of the basic ideas of first-year students. Empirical data were obtained based on the psychological method by L.N. Sobchik “Diagnostics of interpersonal relations” (DIR). The results obtained make it possible to carry out preventive psychohygienic activities with students to form their social adaptability and maintain mental health

Pediatric endocrine surgery development

Department of pediatric surgery at the Endocrinology Research Centre has been around for nearly two years. During operation, surgical treatment has received more than 500 patients with various endocrine disorders. The article discusses modern diagnostic approaches and surgical options for diseases included in the new direction of pediatric surgery endocrine surgery in children. There are discussions about options for radical treatment of Graves disease in children, positive and negative aspects of surgical and radioactive iodine treatment. Is own stats of postoperative hyperparathyroidism. Is proposed to optimize the algorithm of actions in identifying thyroid nodules in children. In primary hyperparathyroidism, the emphasis is on the complexity of the postoperative management of patients related to the feature of childrens age in determining the severity of the reactions on the water-electrolyte disorders. Separately reviewed the literature of the adrenal glands diseases in children, demonstrating their own clinical cases which required surgical intervention. The authors describe the possibilities of modern neurosurgical equipment in the Endocrinology Research Centre in operations on the pituitary gland in children. Patients of different age groups performed transnasal transsphenoidal removal of tumors of the chiasm-sellar region using endoscopic assistance. The article also cited research data of pancreas diseases and their surgical treatment. Much attention is paid to the gender section of endocrine surgery in children. Discusses the tactics in disorders of sex development, gonadal tumors in children, diseases of the breast. In conclusion outlines the prospects for the development of endocrine surgery in children

Analysis of Electric Vehicles Motion Modes Influence on Traction Batteries Aging Based on WLTC

В работе рассмотрены темпы роста электротранспортных средств с учетом развития электрохимических накопителей энергии. Определены основные механизмы старения литиевых аккумуляторов в условиях неравномерной нагрузки и с учетом реверсивного характера процессов энергообмена с короткими режимами подзаряда аккумуляторов при рекуперативном торможении. Для оценки старения литиевого аккумулятора за основу принят ездовой цикл WLTC, в соответствии с которым формировалась нагрузка на блок накопителей электромобиля. В качестве исследуемого образца принят Nissan Leaf, оснащенный различными по энергоемкости блоками накопителей (БН). Получены для одной аккумуляторной ячейки токовые диаграммы, приведены минимальные, средние и максимальные токи, а также длительности режимов тяги, торможения и остановки в различных режимах управления электроподвижного состава. Сделано предположение о росте энергоемкости БН в будущем периоде и определено ее влияние на нагрузку аккумуляторной батареи (АБ). На основе проведенной обработки данных выявлены основные изменения в протекающих в энергоустановке процессах, связанные с увеличением энергоемкости БНThe paper considers the growth rates of electric vehicles, taking into account the development of electrochemical energy storage. The main lithium batteries aging mechanisms under conditions of uneven load and reversible nature of energy exchange processes with short modes of recharging batteries during regenerative braking are determined. To assess the aging of the lithium battery, the WLTC driving cycle was taken as a basis, in accordance with which the load on the electric vehicle energy storage unit the was formed. A Nissan Leaf equipped with energy storage units (ESU) of different energy intensity was adopted as a test sample. Current diagrams were obtained for one battery cell, minimum, average and maximum currents, as well as durations of traction, braking and stopping modes in various control modes of electric rolling stock are given. An assumption is made about the growth of the energy intensity of the ESU in the future period and its influence on the load of the storage battery is determined. On the basis of the data processing carried out, the main changes in the processes occurring in the power source, associated with an increase in the energy intensity of the ESU, have been reveale

Dinamika klyuchevykh mediatorov insulinorezistentnosti u bol'nykh sakharnym diabetom 2 tipa pri primenenii metformina (Formin Pliva?)

Цель. Изучение влияния формина (метформина) не только на состояние углеводного, но и липидного обмена, динамику содержания лептина, его растворимого рецептора и альфа-фактора некроза опухолей (альфа-ФНО) в сыворотке крови у больных СД 2. Материалы и методы. Обследовано 262 больных. Общий анализ крови и мочи проводили через каждый месяц наблюдения, а биохимический анализ крови, включая содержание общего ХС, ТГ, ХС ЛПНП и ЛПОНП и ХС ЛПВП, мочевины, креатинина, печеночных ферментов, проводили на 1-м и 4-м визитах. Лечение формином проводилось в течение не менее 12 нед. и изучалось при этом его влияние на состояние углеводного и липидного обмена у больных СД 2. Из общего числа обследованных у 26 больных на фоне терапии формином изучалось содержание лептина, растворимого рецептора к лептину и альфа-ФНО. Результаты. На фоне лечения формином у больных отмечалось улучшение углеводного обмена, которое сопровождалось статистически достоверным снижением гликемии натощак. Компенсация углеводного обмена у больных также сопровождалась статистически достоверным уменьшением индекса мас? сы тела с 34,02+0,33 кг/м2 до 32,73+0,33 кг/м2. У больных на фоне лечения формином наблюдается недостоверное снижение содержания лептина, растворимого рецептора к лептину и статистически достоверное снижение альфа-ФНО в сыворотке крови. Выводы. проведенные исследования показывают, что формин обладает выраженным антигипергликемическим эффектом, способствует улучшению компенсации углеводного обмена, что сопровождается статистически достоверным снижением гликемии и уровня гликозилированного гемоглобина в сыворотке крови. Наряду с этим на фоне терапии формином отмечается снижение уровня холестерина ЛПНП и повышение содержания холестерина ЛПВП, при практически неизмененных показателях содержания общего холестерина в сыворотке крови. Кроме того, лечение формином способствует статистически достоверному снижению содержания альфа-ФНО и умеренному понижению уровня лептина и его растворимого рецептора в сыворотке крови

Primary hyperparathyroidism in young patients in Russia: high frequency of hyperparathyroidism-jaw tumor syndrome

Background: Primary hyperparathyroidism (PHPT) is a relatively rare disorder among children, adolescents and young adults. Its development at an early age is suspicious for hereditary causes, though the need for routine genetic testing remains controversial. Objective: To identify and describe hereditary forms of PHPT in patients with manifestation of the disease under 40 years of age. Design: We enrolled 65 patients with PHPT diagnosed before 40 years of age. Ten of them had MEN1 mutation, and PHPT in them was the first manifestation of multiple endocrine neoplasia type 1 syndrome. Methods: The other fifty-five patients underwent next-generation sequencing (NGS) of a custom-designed panel of genes, associated with PHPT (MEN1, CASR, CDC73, CDKN1A, CDKN1B, CDKN1C, CDKN2A, CDKN2C, CDKN2D). In cases suspicious for gross CDC73 deletions multiplex ligation-dependent probe amplification was performed. Results: NGS revealed six pathogenic or likely pathogenic germline sequence variants: four in CDC73 c.271C>T (p.Arg91*), c.496C>T (p.Gln166*), c.685A>T (p.Arg229*) and c.787C>T (p.Arg263Cys); one in CASR c.3145G>T (p.Glu1049*) and one in MEN1 c.784-9G>A. In two patients, MLPA confirmed gross CDC73 deletions. In total, 44 sporadic and 21 hereditary PHPT cases were identified. Parathyroid carcinomas and atypical parathyroid adenomas were present in 8/65 of young patients, in whom CDC73 mutations were found in 5/8. Conclusions: Hereditary forms of PHPT can be identified in up to 1/3 of young patients with manifestation of the disease at <40 years of age. Parathyroid carcinomas or atypical parathyroid adenomas in young patients are frequently associated with CDC73 mutations

State-of-Charge Estimation of Lithium-Ion Battery Based on Extended Kalman Filter Algorithm

При определении уровня заряда (УЗ) накопителя энергии электрического транспортного средства (ЭТС) на основе схемы замещения литий-ионного аккумулятора (ЛИА) возникают значительные трудности. Так, для оценки УЗ использован расширенный фильтр Калмана (EKF, Extended Kalman filter). Моделирование и экспериментальные результаты показывают, что оценка УЗ может быть выполнена с использованием алгоритма EKF для дорожных условий по циклу движения в Китае (Chinacar) и новому европейскому циклу (NEDC). По сравнению с кулонометрическим методом средняя ошибка оценки УЗ – 1,042 и 1,138 % для циклов соответственно, максимальная ошибка не превышает 4 %. Применение алгоритма для определения УЗ имеет достаточную устойчивость и сходимостьAs the core component of electric vehicle, lithium-ion battery needs to adopt effective battery management method to prolong battery life and improve the reliability and safety. The accurate estimation of the battery SOC can be used to prevent the battery over charge and over discharge, reduce damage to the battery and improve battery performance, which plays a vital role in the battery management system. The study of battery SOC estimation mainly focused on the battery model construction and SOC estimation algorithm. Aiming at the problem that the state of charge (SOC) of electric vehicle is difficult to be accurately estimated under complex operating conditions, based on the parameter identification of the equivalent circuit of a ternary polymer lithium-ion battery, an Extended Kalman Filter (EKF) algorithm was used to estimate the SOC of the ternary polymer lithium-ion battery. Simulation and experimental results show that the estimation of SOC can be carried out by using the EKF algorithm under the conditions of China Passenger Car Condition (Chinacar) and new European driving cycle (NEDC) Compared with the coulomb counting method, the average error of SOC estimation can be realized is 1.042% and 1.138% respectively, the maximum error within 4%. Application of this algorithm to achieve SOC estimation has good robustness and convergenc

Factors promoting development of renal tubulointerstitial lesions in patients with diabetes mellitus

Aim. To identify profibrogenic mediators, markers of endothelial dysfunction and hemostasis in patients with diabetes mellitus (DM) and chronickidney disease (CKD). Materials and methods. The study included 120 patients with DM and 20 age-matched normotensive subjects without DM showing the glomerularfiltration rate (GFR) > 60 ml/min/1.73 m3. Four groups of patients were distinguished: 1 - DM2 patients without renal pathology (n=33), 2 - DM2 patients with diabetic nephropathy (n=24), 3 - DM2 patients with ischemic nephropathy (IN) (n=33) verified by contrast visualization techniques(multispiral CM of abdominal aorta and renal arteries, abdominal angiography of renal arteries or MR angiography of renal arteries and abdominal aorta), 4 - DM1 patients with DN (n=30). Clinical examination included assessment of complaints, analysis of medical history of the main diseaseand concomitant disorders, determination of the main clinical and biochemical characteristics of blood and urine, measurement of НbА1с and 24-hralbuminuria (AU) by standard methods, estimation of GFR by the MDRD formula, ECG, echocardiography, 24-hr AP monitoring, counseling bycardiologist and ophthalmologist (fundal examination by ophthalmoscopy). Standard kits were used to detect profibrogenic mediators and markersof endothelial dysfunction including transforming growth factor-beta (TGF-b), angiotensin II (AT II), monocyte chemoattractant protein (MCP-1),regulated on activation normal T cell expressed and secreted (RANTES), adhesion factors (intracellular adhesion molecule (ICAM-1), vascular celladhesion molecule (VCAM-1) vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), asymmetric dimethylargnine (ADMA), homocysteine(HCYST), metalloproteinases (MMP), von Willebrand factor (vWF), plasminogen activator inhibitor (PAI-I). Results. DM patients with CKD had elevated blood profibrogenic cytokine (MCP-1, TGF-1b, IL-6) and extracellular matrix degradation factor(MMP-9) levels compared with patients without CKD and healthy subjects. These changes were unrelated to the type of diabetes or the cause ofnephropathy, which suggests their contribution to renal pathology through the universal mechanism of tubulointerstitial fibrosis. Activation of profibrogeniccytokines in DM patients with CKD was closely associated with endothelial dysfunction manifest as enhanced production of blood adhesive angiogenic, thrombogenic factors (FW, PAI, VICAM, sICAM, VEGF), and endothelium-affecting factors (ADMA, homocysteine). Mediators of inflammationand fibrogenesis in these patients negatively correlated with GFR and positively with AU, the main markers of renal dysfunction. Hyperuricemia,TGF-1b, ADMA, and MCP-1 are considered to be the risk factors of impaired renal filtration function. Conclusion. The level of profibrogenic cytokines and ndothelial dysfunction factors in DM patients with different renal lesions reflects severity of tubulointerstitialfibrosis. It may be used for the purpose of prognostication and substantiation of intensification of secondary prophylaxis of renal insufficiency