MODEL PŁASKIEJ WARSTWY DIELEKTRYCZNEJ ANTENY Z NAGRZEWANIEM AERODYNAMICZNYM

To protect the antenna systems of modern aircraft, radio-transparent dielectric fairings are widely used. At low flight speeds, when designing and evaluating the characteristics of the fairing-antenna, it is assumed that the dielectric constant is a constant value and does not depend on the aircraft's flight speed. As the flight speed increases, as a result of aerodynamic heating of the fairing, its dielectric permeability changes, which leads to errors in the processing of received signals. Currently, to take into account the effect of dielectric coatings heating when designing antenna systems, the temperature of the fairing wall is averaged over its thickness. This method during maneuvering and at high flight speeds leads to large errors in determining the characteristics of the fairing antenna since the nature of the temperature distribution along the thickness of the fairing wall is not taken into account. A new approach to the analysis of dielectric layers with their uneven heating along the thickness is proposed. The obtained results make it possible to adjust the signal processing algorithms with analog and digital matrices, as a result of taking into account the emerging heat flows affecting the fairing of the aviation antenna, which leads to the improvement of the characteristics of the antenna systems.Aby chronić systemy antenowe nowoczesnych samolotów, szeroko stosuje się radioprzepuszczalne owiewki dielektryczne. Przy małych prędkościach lotu przy projektowaniu i ocenie charakterystyk anteny owiewkowej przyjmuje się, że stała dielektryczna jest wartością stałą i nie zależy od prędkości lotu samolotu. Wraz ze wzrostem prędkości lotu, w wyniku nagrzewania się aerodynamicznego owiewki, zmienia się jej przepuszczalność dielektryczna, co prowadzi do błędów w przetwarzaniu odbieranych sygnałów. Obecnie, aby uwzględnić wpływ nagrzewania powłok dielektrycznych przy projektowaniu systemów antenowych, temperaturę ścianki owiewki uśrednia się w stosunku do jej grubości. Metoda ta podczas manewrowania i przy dużych prędkościach lotu prowadzi do dużych błędów w określaniu charakterystyk anteny owiewki, gdyż nie bierze się pod uwagę charakteru rozkładu temperatury wzdłuż grubości ścianki owiewki. Zaproponowano nowe podejście do analizy warstw dielektrycznych przy ich nierównomiernym nagrzewaniu na całej grubości. Uzyskane wyniki pozwalają na dostosowanie algorytmów przetwarzania sygnału z matrycami analogowymi i cyfrowymi, w wyniku uwzględnienia powstających strumieni ciepła wpływających na owiewkę anteny lotniczej, co prowadzi do poprawy charakterystyki systemów antenowych

Russian Society's Civilizational Transit

This paper deals with the issue of specific civilizational process formation in Russia as a new figuration and configuration of the forms of modernity. It is argued that explanations of the dynamics of Russian society are often based on the idea of predestination of the trajectory of its development (path dependency) that is caused either by the universal logic of modernization and globalization or by persistence of the basic cultural program or matrix which is reproduced in social practices. A civilizational transit of Russian society phenomena is discussed within multiple modernities theory as a new perspective that allows overcoming some of the problems with the predominant approaches to Russian modernization. Civilizational approaches to analyses of Russian culture, politics and society have been associated mostly with theories of ‘historical cycles’ worked out in late nineteenth century and the first half of the twentieth century. More recently a considerable attention has been devoted to different versions of ‘neoEurasianism’. In addition, the notion of ‘clash of civilizations’ proposed by Samuel Huntington became prominent in the political discourse in Russia at the end of 1990s. At the same time, the concept of civilization is discussed widely in today’s historical sociology. A specific school of ‘civilizational analysis’ that draws on the ideas of Shmuel Eisenstadt emerged at the end of the 1990s. This perspective has already influenced some new trends in sociology of religion, political sociology and international relations theory. The panel seeks to demonstrate the relevance of a new wave of civilizational analysis for understanding contemporary Russian culture, politics and society. Keywords: Russian society, civilizational transit, multiple modernitie

Prediction by three-dimensional mathematical modeling of the gas turbine low-emission combustion chambers thermo-acoustic characteristics

Розглянуто питання числового моделювання термо-акустичних процесів в камерах згоряння газотурбінних двигунів. Проведено аналіз пульсаційних процесів в низькоемісійній камері згоряння газотурбінного двигуна за допомогою сучасних інструментів обчислювальної гідродинаміки. Представлені результати моделювання процесів нестаціонарного горіння в низькоемісійній камері згоряння газотурбінного двигуна. За результатами тривимірних розрахунків визначено максимальні по амплітуді пульсації, що виникають у жаровій трубі і міжтрубному просторі камери згоряння газотурбінного двигуна.The use of modern tools of computational fluid dynamics for investigation the pulsation processes in the combustion chamber caused by the design features of flame tubes and aerodynamic interaction compressor, combustor and turbine is discussed. Purpose. Investigation and forecasting of non-stationary processes in gas turbine low-emission combustion chambers using mathematical modeling. Design/methodology/approach. The numerical experiment by definition of pressure pulsations level in the gas turbine combustion chamber is performed. The results of the numerical experiments using a three-dimensional mathematical models in gaseous fuels combustion chambers are adequately reflect the physical and chemical processes of unsteady combustion and can be recommended for optimizing the geometrical and operational parameters of low-emission combustion chambers. Findings. According to the results of three-dimensional calculations, the maximum amplitude fluctuation arising in the flame tube and the annulus gas turbine combustion chambers are defined. Originality/value. The application of such mathematical models for the creation new samples combustors operating at a lean air-fuel mixture as well as the modernization of the existing cameras to develop constructive measures aimed at reducing the likelihood of pulsation combustion modes, is advisable.Рассмотрены вопросы численного моделирования термо-акустических процессов в камерах сгорания газотурбинных двигателей. Проведен анализ пульсационных процессов в низкоэмиссионной камере сгорания газотурбинного двигателя с помощью современных инструментов вычислительной гидродинамики. Представлены результаты моделирования процессов нестационарного горения в низкоэмиссионной камере сгорания газотурбинного двигателя. По результатам трехмерных расчетов определены максимальные по амплитуде пульсации, возникающие в жаровой трубе и межтрубном пространстве камеры сгорания газотурбинного двигателя

ENERGY DATA ANALYTICS FOR IMPROVED RESIDENTIAL SERVICE QUALITY AND ENERGY EFFICIENCY

Utility companies generally have an extensive customer base, yet their knowledge about individual households is small. This adversely affects both the development of innovative, household specific services and the utilities’ key performance indicators such as customer loyalty and profitability. With the goal to overcome this knowledge deficit, persuasive systems in the form of customer self-service applications and efficiency coaching portals are becoming the getaway of data exchange between utility and user. While improved customer interaction and the collection of customer data within respective information systems is an important step towards a service-oriented company, the immediate value generated from the collected data is still limited, mostly due to the small fraction of customers actually using such systems. We show how to utilize the knowledge gained from the sparse number of active web users in order to provide low-cost and large-scale insights to potentially all residential utility customers. We do so using machine-learning-based Green IT artifacts that allow for improving decision-making, effectiveness of energy audits, and conservation campaigns, thus ultimately increasing the customer value and adoption of related services. Moreover, we show that data from the publically available geographic information systems can considerably improve the decision quality

INCENTIVES TO GO GREEN: AN EMPIRICAL INVESTIGATION OF MONETARY AND SYMBOLIC REWARDS TO MO-TIVATE ENERGY SAVINGS

Green information systems have been shown to contribute to environmental sustainability and help to prevent associated problems. Private households account for 25% of primary energy consumption in western countries, and therefore hold a great potential to curb the use of fossil fuels and prevent cli-mate change. As such, green information systems should not focus solely on the organizational con-text, but also target a single individual’s behaviour in their home. Personal information systems (e.g., web portals) can achieve this focus, however, need to be actively used to produce effects. System us-age can be effectively motivated through incentives, and therewith contribute to positive outcomes. Incentives are either monetary or non-monetary and can be implemented in different scales. In a large field experiment (n= 2,355), with real energy customers of a utility company, we tested the effective-ness of different types and sizes of incentive in motivating active system usage. We show that incen-tives significantly increased system usage of participants, and additionally increased energy savings. However, monetary incentives were not necessarily superior to non-monetary incentives

Study of helium swelling in nitride ceramics at different irradiation temperatures

This paper presents the results of a systematic study of helium swelling and the subsequent process of degradation of the near-surface layer of aluminum-based nitride ceramics. The samples were irradiated with 40 keV He2+ ions at temperatures of 300 and 1000 K with a fluence of 1 × 1017-5 × 1017 ions/cm2. The choice of radiation doses and temperature conditions was due to the possibility of simulating reactor tests of structural materials. It has been established that an increase in the irradiation fluence leads to the formation of large agglomerates of clusters of helium bubbles, as well as an increase in the degree of roughness and waviness of the surface with the formation of crater-like inclusions. In the case of irradiation at high temperatures, there was a slight decrease in the average size of helium inclusions compared with irradiation at room temperature. However, the density of inclusions and surface roughness were much higher. It is established that irradiation at room temperatures leads to a sharp decrease in ceramics density, as well as deformation of the crystal structure due to an increase in the density of dislocations and macrostresses in the structure. The decrease in ceramics density due to the formation of helium inclusions led to an increase in porosity and a defective fraction in the structure of the surface layer of ceramics. © 2019 by the authors

Synthesis of Cu/CuO nanostructures obtained by electrochemical deposition

Unique physical-chemical properties of nanostructured materials are explained by the crystal structure, geometry and conductive properties that can be controlled by changing the synthesis conditions of nanostructures. In turn, the process of electrochemical deposition makes it possible to control the formation of nanostructures and their physical-chemical properties with high accuracy. Electrochemical synthesis in tracks of the template was carried out in potentiostatic mode at a voltage of 0.5 to 1.5 V. The electrolyte temperature was 25, 35, 50 °C. The composition of the electrolyte solution: CuSO4·5H2O (238g/l), H2SO4 (21g/l). The yield of copper by current from the sulfuric acid solutions of electrolytes is 100%. The growth of nanostructures was monitored by the chronoamperometry method with the "Agilent 34410A" multimeter. Since the template PET matrices are dielectric, a layer of gold with a thickness of no more than 10 nm, which is further a working electrode (cathode) during electrochemical deposition, was deposited to create a conductive layer by magnetron sputtering in a vacuum. By controlling the deposition time, the difference in the applied potentials, the electrolyte temperature, we can change the geometric parameters of synthesized nanostructures. All possible reactions associated with the synthesis process are listed below

Phase transformations and photocatalytic activity of nanostructured Y2O3/TiO2-Y2TiO5 ceramic such as doped with carbon nanotubes

This work is devoted to the study of phase transition processes in nanostructured ceramics of the Y2O3/TiO2-Y2TiO5 type doped with carbon nanotubes as a result of thermal annealing, as well as to the assessment of the prospects of the effect of phase composition on photocatalytic activity. By the method of X-ray phase analysis, it was found that an increase in the annealing temperature leads to the formation of the orthorhombic phase Y2TiO5, as well as structural ordering. Based on the obtained UV spectra, the band gap was calculated, which varies from 2.9 eV (initial sample) to 2.1 eV (annealed at a temperature of 1000 ◦C). During photocatalytic tests, it was established that the synthesized nanostructured ceramics Y2O3/TiO2-Y2TiO5 doped CNTs show a fairly good photocatalytic activity in the range of 60–90% decomposition of methyl orange. © 2020 by the authors.Ministry of Education and Science of the Republic of Kazakhstan: BR05235921This study was funded by the Ministry of Education and Science of the Republic of Kazakhstan (grant BR05235921)

Oxidation of copper nanotubes embedded in the PET template

Copper oxide based nanostructures possess excellent physical and chemical properties and has many practical applications such as an medicine, sensors, catalysis, solar cell technology and photovoltaic as well as nanoelectronic. Different approaches have been used to synthesize CuO nanostructures: thermal oxidation of copper, hydrothermal route, aqueous reaction, vapor-liquid-solid synthesis, solution-liquid-solid synthesis as well as physical methods such as laser ablation, arc discharge, precursor thermal decomposition, electron beam lithography, and template-assisted synthesis. However, all these methods require high temperatures, complicated equipment or long reaction time

ДАВНЬОРУСЬКІ МОГИЛЬНИКИ КОПИРЕВОГО КІНЦЯ

Статтю присвячено вивченню могильників давньоруського часу, виявлених під час розкопок на території стародавнього району Києва – Копиревого кінця. На сьогодні тут відкрито і частково досліджено чотири могильники, які датують Х – першою половиною ХІІІ ст. Перший могильник був між вул. Кудрявською (на півночі) і вул. Січових Стрільців (на півдні), між продовженням вул. Кудрявської (на заході) і Вознесенським узвозом (на сході). Під час розкопок цього могильника, від 1989 до 2018 рр. було досліджено 134 поховання ХІ–ХІІІ ст. Загальна площа могильника: ≈2,88 га. Другий (прихрамовий) могильник був на Вознесенському узвозі, 20. Його  знайшли у 1947 р. під час дослідження фундаментів давньоруського храму, де було відкрито 35 поховань другої половини ХІ–ХІІ ст. Загальна площа могильника: ≈2,50 га. Третій (прихрамовий) могильник був на північ від другого, розташований неподалік: по Вознесенському узвозу, 22. Низку поховань було виявлено під час дослідження фундаментів церкви кінця ХІІ ст. у 1989–1990 рр. Загальна площа могильника: ≈1,65 га. Четвертий (прихрамовий) могильник, поховання якого було досліджено у 1985, 1987 і 1990 рр., розміщувався на схилі пагорба, по провулку Киянівському, 4 та 10–10б. Тут було відкрито 15 поховань ХІІ – першої половини ХІІІ ст., що належали до церкви кінця ХІ ст., яка могла бути на розі Киянівського провулку та Воздвиженського узвозу. Загальна площа могильника: ≈2,29 га. Отже, на цей час на території Копиревого кінця загалом відкрито і досліджено 219 поховань давньоруського часу, а загальна площа усіх чотирьох могильників могла становити майже 10 га