РАСЧЕТ ПОТЕРЬ ЭНЕРГИИ ПРИ ОГРАНИЧЕНИИ СКОРОСТИ

The system of rate setting and accounting of electric power consumption is of greatimportance for power saving in electric train traction. But the author argues that this system should be supplemented with method of calculation and statistic estimation of power losses caused by fixed speed limits.Система нормирования и учета энергозатрат оказывает существенное влияние на энергосбережение в тяге поездов, но эту систему необходимо дополнить методикой расчета и статистической оценки потерь энергии и времени из-за ограничений скорости

РЕЗЕРВЫ ТЕХНИЧЕСКОЙ СКОРОСТИ ПРИ НАЛИЧИИ ЕЕ ОГРАНИЧЕНИЙ

Power consumption rate setting influences energy saving in the process of train traction. Possible growth of cruise, line and route speed is limited by track infrastructure, safety requirements and by additional power consumption.Therefore there is a problem of assessment of possible cruise speed growth under the conditions when there are speed restrictions due to the infrastructural issues (there are 4900 speed limits imposed a long of about 6000 km within the rail network of JSC Russian Railways), as well as of estimation of supplementary power inputs.Such a system should be completed by the methods of statistical assessment of power and time losses caused by imposed speed restrictions. The dependencies between specific power consumption rates for the traction are found, given the example of cruise speed at Moscow-Vyazma track section. The number of coaches in a passenger train is also considered as specific indicator.The analysis of received data permitted to decompose singular restrictions into point and prolonged limits. The survey of railway staff opinions helped to determine certain dependencies between speed, train length, and some safety precautionvalues to be further used to compute time and electric power losses.Нормирование энергозатрат оказывает существенное влияние на энергосбережение в тяге поездов и соответственно, на функционирование железнодорожного транспорта в целом. Но эту систему необходимо дополнить методикой расчета и статистической оценки потерь энергии и времени из-за ограничений скорости. На основе полученных данных введено разделение одиночных ограничений на точечные и протяженные. С помощью экспертного опроса установлены определенные зависимости скорости, длины поезда, запаса страховочных величин, которые предполагается принимать во внимание при расчете потерь времени и расходов электроэнергии.

РЕЗЕРВЫ РЕКУПЕРАТИВНОГО ТОРМОЖЕНИЯ ЛОКОМОТИВОВ ПОСТОЯННОГО ТОКА

Regeneration system is mounted on all electric locomotives designed for driving freight trains. There has been a tendency of its use in combination with dynamic brake on passenger locomotives and electric trains.The objective of the authors is to analyze regulatory and protection functions of electrical equipment and its operation in regenerative mode, using analytical method, mathematical calculations, simulation and comparative method.Regenerative braking should be considered as the most effective means of reducing energy consumption in electric traction. Therefore, its scope should be expanded, including its use for returning of kinetic energy of the train to electric traction network. The authors present a methodology for calculating the energy when an electric locomotive moves downhill, analyze individual components of the energy balance, indicate possibility of increasing the efficiency of the locomotive in regenerative behavior. An analytical review of regulatory and protection functions of electrical equipment was carried out and has shown that in regenerative behavior a set of these functions is much broader than in traction. Electric equipment, implementing regeneration, should be improved using new technologies (static converters, onboard microprocessors, high-speed protection). It is necessary to keep the achieved level of functional reliability and maintain proven schematics, including crosscyclic excitation of traction electric motors.Системой рекуперации оборудованы все электровозы, предназначенные для вождения грузовых поездов. Наметилась также тенденция ее применения в сочетании с реостатным тормозом на пассажирских электровозах и электропоездах. Приведена методика энергетического расчета при движении электровоза под уклон, проанализированы отдельные составляющие энергобаланса, указаны возможности повышения коэффициента полезного действия локомотива в режиме рекуперации. Выполнен аналитический обзор функций регулирования и защиты электрооборудования, который показывает, что в режиме рекуперации набор этих функций значительно шире, чем в тяге

Special features of high-speed interaction of supercavitating solids in water

Special features of material behavior of a supercavitating projectile are investigated at various initial velocities of entering water on the basis of the developed stress-strain state model with possibility of destruction of solids when moving in water and interacting with various underwater barriers with the use of consistent methodological approach of mechanics of continuous media. The calculation-experimental method was used to study the modes of motion of supercavitating projectiles at sub- and supersonic velocities in water medium after acceleration in the barrelled accelerator, as well as their interaction with barriers. Issues of stabilization of the supercavitating projectile on the initial flight path in water were studied. Microphotographs of state of solids made of various materials, before and after interaction with water, at subsonic and supersonic velocities were presented. Supersonic velocity of the supercavitating projectile motion in water of 1590 m/s was recorded

Association of Chrononutrition Indices with Anthropometric Parameters, Academic Performance, and Psychoemotional State of Adolescents: A Cross-Sectional Study

Adolescents are an at-risk group for circadian misalignment. The contribution of sleep–wake rhythm instability to the psychoemotional, cognitive, and weight disorders of adolescents has been studied in sufficient detail. At the same time, there is insufficient information about the association between chrononutrition indices and the well-being of adolescents. The aim of this study is to investigate the relationship between chrononutrition indices and academic achievement, psychoemotional state, and anthropometric indicators in adolescents. The study involved 12,759 students in grades 6–11 of secondary schools, aged 14.2 ± 1.7 years old; 57.2% of whom were girls. Participants provided personal data, frequency and time of meals during the day and at night, on weekdays and weekends, and completed the Zung Self-Rating Depression Scale and the Yale Food Addiction Scale. There is a U-shaped association between eating mid-phase (EPFc), eating jetlag (EJL), and eating window (EW) with GPA, ZSDSI, and FA. At the same time, the frequency of night eating (NE) is linearly associated with the studied parameters. NE is the strongest predictor of ZSDSI (β = 0.24), FA (β = 0.04), and GPA (β = −0.22). EPFc, EJL, and EW practically do not differ in the strength of their association with the studied indicators. ZSDSI is most closely associated with the chrononutrition indices. There is a weak negative association between BMI and EW (β = −0.03) and NE (β = −0.04). Thus, circadian eating disorders are more often observed in adolescents with poor academic performance, high levels of depression, and food addiction. © 2023 by the authors.1021051201895-9, FUUU-2022-0066; Ministry of Education and Science of the Russian Federation, MinobrnaukaThe research was carried out within the framework of the research project at the Institute of Physiology of the Federal Research Centre Komi Scientific Centre of the Ural Branch of the Russian Academy of Sciences FUUU-2022-0066 (No. 1021051201895-9). The research funding from the Ministry of Science and Higher Education of the Russian Federation (Ural Federal University Program of Development within the Priority-2030 Program) is gratefully acknowledged

Association between food addiction and time perspective during COVID-19 isolation

Purpose: The concept of time perspective (TP) implies that a mental focus on past, present, or future affect a person makes decisions and take action. Inability to plan their life for a sufficiently long time perspective due to the COVID-19 pandemic appeared to have a pronounced impact on a human’s lifestyle influencing their thoughts, feelings, and behaviors, including eating behavior. This study tested two hypotheses: (a) that during COVID-19 isolation, the incidence rate of food addiction is increased, and (b) people with present TP are more likely exhibited signs of food addiction (FA). Methods: The final study sample included 949 people, mean age 21.8 ± 7.8 years (range: 17–71 years, women: 78.3%). Each participant indicated their personal data and completed Yale Food Addiction Scale and the Zimbardo Time Perspective Inventory. Results: There was an increased incidence rate of FA (OR = 1.678, 95% CI = 1.324, 2.148, p = 0.000) during COVID-19 isolation. Individuals with balanced, future, and past positive TP were less likely to exhibit symptoms of FA. Persons with past negative, and present hedonistic TP were more likely to exhibit signs of FA. Conclusion: There was an increased incidence rate of FA during COVID-19 isolation. Persons with shortened time horizon are more likely to exhibit symptoms of FA. Level of evidence: Level V, cross-sectional descriptive study. © 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG

ФОРМИРОВАНИЕ ВЕЗИКОУРЕТРАЛЬНОГО АНАСТОМОЗА ПРИ ВЫПОЛНЕНИИ ЭНДОВИДЕОХИРУРГИЧЕСКОЙ ВНЕБРЮШИННОЙ РАДИКАЛЬНОЙ ПРОСТАТЭКТОМИИ: СРАВНИТЕЛЬНОЕ ИССЛЕДОВАНИЕ ТРЕХ РАЗЛИЧНЫХ МЕТОДИК

Extraperitoneoscopic (endovideosurgical extraperitoneal) radical prostatectomy (ERPE) is one of the current surgical treatment procedures in patients with localized prostate cancer. Failure of vesicourethral anastomosis (VUA) and the development of its stricture are common surgi-cal complications. This investigation compares the efficiency and safety of different procedures to form VUA during ERPE: an interrupted suture (n = 24), a MVAC suture (n = 23), and a MVAC suture using self-locking suture material (n = 24). The performed comparative analysis of different procedures for forming VUA during ERPE may conclude that there are a number of advantages of the MVAC suture ap-plying the self-locking suture material. These advantages include less time taken to form VUA with the low frequency of complications, such as leakages occurring during control cystography or the development of delayed VUA strictures. Экстраперитонеоскопическая (эндовидеохирургическая внебрюшинная) радикальная простатэктомия (ЭРПЭ) – один из современных способов оперативного лечения пациентов с локализованными формами рака предстательной железы. Несостоятельность везикоуретрального анастомоза (ВУА) и развитие стриктуры ВУА являются частыми осложнениями операции. В данном исследовании мы приводим сравнение показателей эффективности и безопасности различных способов формирования ВУА при выполнении ЭРПЭ: узловой шов (n = 24), MVAC-шов (n = 23) и MVAC-шов с использованием самофиксирующегося шовного материала (n = 24). Проведенный сравнительный анализ различных способов формирования ВУА при выполнении ЭРПЭ позволяет сделать вывод о наличии ряда преимуществ при использовании MVAC-шва в сочетании с применением самофиксирующегося шовного материала. Эти преимущества включают более короткое время, затраченное на создание ВУА, при низкой частоте развития таких осложнений, как формирование затеков при контрольной цистографии или развитие отсроченных стриктур ВУА.

Food addiction and weight in students with high academic performance

Objective: The purpose of this study was to analyse the relationships between food addiction (FA), anthropometric characteristics and academic performance. Design: The average age (sd) of the participants was 17·5 (sd 2·7) years (64·1 % female). Each study participant indicated their sex, height, weight and academic performance and completed the Yale Food Addiction Scale. Setting: Syktyvkar, Kirov, Tyumen, Yekaterinburg, Russia; Aizawl, India. Participants: The study involved 3426 people. Results: FA was found in 8·7 % of participants from Russia and 14·6 % from India. In schoolchildren but not in university students, high academic performance was associated with a higher incidence rate of FA detection (OR = 1·16, 95 % CI 1·07, 1·26) and a lower BMI (OR = 0·72, 95 % CI 0·56, 0·94). Conclusions: These data showed an increased incidence rate of FA detection in adolescents with high academic performance. © The Author(s) 2021

The Influence of School Start Time on Sleep Duration and Academic Performance of Secondary School Students in Yekaterinburg

Изучено влияние времени начала занятий на функцию сна, самочувствие и успеваемость учеников средних школ Екатеринбурга. Показано, что при начале занятий в первую смену в 9 часов продолжительность сна у подростков составляет на 14 минут больше, чем при начале занятий в 8 часов, и они имеют более высокую успеваемость. Результаты исследования согласуются с ранее полученными данными о благоприятном влиянии позднего времени начала занятий на сон и успеваемость учеников.The influence of the school start time on sleep function, well-being and academic performance of secondary school students in Yekaterinburg was studied. It was shown that at the beginning of classes in the first shift at 9 o’clock, the duration of sleep in adolescents is 14 minutes longer than at the beginning of classes at 8 o’clock, and they have higher academic performance. The results of the study are consistent with previously obtained data on the positive effect of late school start time on student’s sleep and performance