45 research outputs found
NEW DATA ON THE GEOLOGICAL STRUCTURE OF THE SYNNYR ULTRA-K INTRUSIVE FORMATION
The Synnyrsky massif is the largest intrusive containing ultra-potassium syenites, synnyrites, which are raw materials for the production of potash fertilizers and aluminum. An extensive complex of geological and geochemical studies has been carried out, including exploratory drilling, which was carried out on the massif for the first time. The data obtained made it possible to significantly change the idea of the structure of the massif, including a different look at the regularities of the placement of potash-alumina ores, significantly increasing the ore potential and the reliability of its assessment. The present study discusses the existence within the Synnyrsky complex of the third, previously undetected, large intrusive phase, which has its own geological and geochemical features
ОСОБЕННОСТИ ИССЛЕДОВАНИЙ АЭРОУПРУГИХ КОЛЕБАНИЙ БЕСПИЛОТНЫХ ЛЕТАТЕЛЬНЫХ АППАРАТОВ С ЭЛЕКТРОПРИВОДОМ РУЛЕЙ
Designing a modern flight vehicle is associated with the need to solve many scientific and technical problems. These tasks include the prevention of insecure self-oscillations in flight, taking into account the elasticity of the structure. These problems relate to dynamic aeroelasticity, a science that examines the interaction of an elastic structure (at its oscillation) with an air flow. Maneuverable unmanned aerial vehicles (UAVs) are considered. Since UAVs are essentially not used without an automatic control system (ACS), its presence must be taken into account when considering the vibrations of an elastic structure in flight. The influence of the elasticity of UAV design on the operation of ACS in flight is manifested in the possibility of self-oscillations in the loop "elastic UAV – ACS". Self-oscillations lead to disruption of normal operation of the onboard equipment or its failure. The complexity of the problem requires its consideration at almost all stages of UAV’s development, including the creation of a prototype and testing. The computational and experimental studies of the characteristics of elastic oscillations in the UAV flight of the cross-shaped scheme are considered. The features of these UAVs (options with a modular design, the nonlinearity of the airframe, rudders, ACS, and others) due to a significant amount of testing that is the basis for the calculations. Electric actuators have a small continuous operation time, and resource use, there are gearboxes with a large gear ratio and backlashes. This determines the dependence of the rotation rigidity of the rudders on the amplitude and frequency, as well as a significant increase in the total moments of inertia. The technique of bench experiment with obtaining data to assess the boundaries of the flutter and the boundaries of the stability of the loop "elastic UAV – ACS" is given. The questions of improvement of the stabilization system of UAV required for the study of its stability at frequencies of elastic oscillations are considered, as well as the evaluation of the limiting cycles of self-oscillations is given.Проектирование современного летательного аппарата (ЛА) связано с необходимостью решения многих научнотехнических задач. В их число входит предотвращение опасных автоколебаний в полете с учетом упругости конструкции. Эти задачи относятся к динамической аэроупругости, науке, в которой исследуется взаимодействие упругой конструкции (при ее колебаниях) с потоком воздуха. Рассматриваются маневренные беспилотные летательные аппараты (БЛА), которые принципиально не допускают применения без системы автоматического управления (САУ), поэтому ее наличие необходимо учитывать при исследовании колебаний упругой конструкции в полете. Влияние упругости конструкции БЛА на работу САУ в полете проявляется в возможности возникновения автоколебаний в контуре «упругий ЛА – САУ». Автоколебания приводят к нарушению нормальной работы бортовой аппаратуры или выходу ее из строя. Сложность данной задачи требует ее рассмотрения практически на всех этапах разработки БЛА, включая создание опытного образца и начало летных испытаний. Представлены расчетно-экспериментальные исследования характеристик упругих колебаний в полете БЛА крестообразной схемы. Особенностями исследуемых БЛА (варианты модульной конструкции, нелинейности корпуса, рулей, САУ и другие) обусловлен значительный объем испытаний, являющихся основанием для расчетов. Электроприводы рулей имеют малое время непрерывной работы и низкий ресурс, в них входят редукторы с большим передаточным отношением и люфтами. С этим связана зависимость жесткости рулей на вращение от амплитуды и частоты, а также существенное увеличение суммарных моментов инерции. Приведена методика стендового эксперимента с получением данных для оценки границ флаттера и границ устойчивости контура «упругий ЛА – САУ». Рассмотрены вопросы доработки контура стабилизации БЛА, необходимой для его устойчивости на частотах упругих колебаний, а также дана оценка предельных циклов автоколебаний
НОВЫЕ ДАННЫЕ О ГЕОЛОГИЧЕСКОМ СТРОЕНИИ СЫННЫРСКОГО УЛЬТРАКАЛИЕВОГО ИНТРУЗИВНОГО МАССИВА
The Synnyrsky massif is the largest intrusive containing ultra-potassium syenites, synnyrites, which are raw materials for the production of potash fertilizers and aluminum. An extensive complex of geological and geochemical studies has been carried out, including exploratory drilling, which was carried out on the massif for the first time. The data obtained made it possible to significantly change the idea of the structure of the massif, including a different look at the regularities of the placement of potash-alumina ores, significantly increasing the ore potential and the reliability of its assessment. The present study discusses the existence within the Synnyrsky complex of the third, previously undetected, large intrusive phase, which has its own geological and geochemical features.Сыннырский массив – крупнейший интрузив, содержащий в своем составе ультракалиевые сиениты, сынныриты, являющиеся сырьем для производства калийных удобрений и алюминия. Выполнен обширный комплекс геолого-геохимических исследований, в том числе поисково-разведочное бурение, которое было проведено на массиве впервые. Полученные данные позволили существенным образом изменить представление о строении массива, в том числе иначе взглянуть на закономерности размещения калийно-глиноземных руд, значительно увеличив рудный потенциал и достоверность его оценки. В настоящем исследовании обсуждается существование в пределах Сыннырского комплекса третьей, ранее не выделяемой, крупной интрузивной фазы, которая имеет свои геолого-геохимические особенности
RESEARCH FEATURES OF AEROELASTIC OSCILLATIONS OF UNMANNED AERIAL VEHICLES WITH ELECTRIC ACTUATOR OF RUDDERS
Designing a modern flight vehicle is associated with the need to solve many scientific and technical problems. These tasks include the prevention of insecure self-oscillations in flight, taking into account the elasticity of the structure. These problems relate to dynamic aeroelasticity, a science that examines the interaction of an elastic structure (at its oscillation) with an air flow. Maneuverable unmanned aerial vehicles (UAVs) are considered. Since UAVs are essentially not used without an automatic control system (ACS), its presence must be taken into account when considering the vibrations of an elastic structure in flight. The influence of the elasticity of UAV design on the operation of ACS in flight is manifested in the possibility of self-oscillations in the loop "elastic UAV – ACS". Self-oscillations lead to disruption of normal operation of the onboard equipment or its failure. The complexity of the problem requires its consideration at almost all stages of UAV’s development, including the creation of a prototype and testing. The computational and experimental studies of the characteristics of elastic oscillations in the UAV flight of the cross-shaped scheme are considered. The features of these UAVs (options with a modular design, the nonlinearity of the airframe, rudders, ACS, and others) due to a significant amount of testing that is the basis for the calculations. Electric actuators have a small continuous operation time, and resource use, there are gearboxes with a large gear ratio and backlashes. This determines the dependence of the rotation rigidity of the rudders on the amplitude and frequency, as well as a significant increase in the total moments of inertia. The technique of bench experiment with obtaining data to assess the boundaries of the flutter and the boundaries of the stability of the loop "elastic UAV – ACS" is given. The questions of improvement of the stabilization system of UAV required for the study of its stability at frequencies of elastic oscillations are considered, as well as the evaluation of the limiting cycles of self-oscillations is given
Dosiomics in the analysis of medical images and prospects for its use in clinical practice
BACKGROUND: In recent years, there has been a notable increase in the number of articles using the term “dosiomics”. However, there are no literature reviews on this topic in the Russian language.
AIM: This study aims to describe the basic principles of dosiomics as a derivative of radiomics and to analyze studies devoted to assessing the possibilities of its application in clinical practice.
MATERIALS AND METHODS: A systematic literature search was performed in the PubMed database using the search query “dosiomics OR dosiomic”, and in the eLibrary database using the search query “dosiomics”. By April 2023, 43 foreign articles and 1 Russian article had been published.
RESULTS: The analysis encompassed 43 foreign studies investigating the use of dosiomics in clinical practice, alongside one Russian article that provided a definition of the term “dosiomics”. The analyzed papers were divided into three groups according to their subject matter, and two tables describing the results of 27 studies on the prediction of clinical outcomes were created.
CONCLUSION: Currently, dosiomics is a new and promising derivative of radiomics used in the textural analysis of medical images associated with radiation treatment of cancer patients. Dosiomics can contribute to the development of a more personalized approach to the planning of radiotherapy, the prediction of radiation damage of normal tissues, and the diagnosis of recurrence
Flax Noils as a Source of Cellulose for the Production of Lyocell Fibers
The production of long flax fiber for the subsequent production of textile yarn is accompanied by the formation of a significant amount of waste—noils, which is a mechanical mixture of long and short flax fibers and shives. Comparative studies of the structure and chemical composition of the fibrous fraction of noils and shives were carried out using IR spectroscopy. The solubility of shives and flax noils in N-methylmorpholine-N-oxide (NMMO) was studied, a comparative analysis of the rheological behavior of solutions of flax and wood cellulose was carried out and the optimal temperature–concentration conditions for obtaining flax fibers from noils were determined. It was shown for the first time that using the method of solid-phase activation of the cellulose-solvent system makes it possible to obtain fibers in a short period of time (no more than 10 min). The structure of both the raw material and the resulting fibers was studied by X-ray diffraction analysis. The thermal properties of a new type of cellulose fibers was evaluated. The complex of the conducted studies allows us to consider flax fibers from noils along with flax fibers from long-staple flax, as a real alternative to fibers from wood pulp