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Публікація Reducing the level of interference considering the morphological characteristics of object in thermal nondestructive testing(2023) Miahkyi, O.; Storozhenko, V.; Orel, R.; Meshkov, S.The interferences characteristic of thermal non-destructive testing that reduces the reliability of the obtained results are described. A methodology for their reduction is proposed, consisting of two interdependent stages. The first stage consists in calculating and analysing the nature and level of the expected signal according to the developed thermophysical model against the background of the experimentally obtained level of interference. According to the results of the analysis of the calculations based on the thermophysical model for the selected samples, the most influential interference was the heterogeneity of the emissivity of the sample surface. The second stage of data processing is devoted to reducing this interference. The second stage consists of processing the thermograms of temperature fields and includes morphological analysis of the surface condition, filtering, and reduction of characteristic interference. It is divided into four practical procedures. Analysis of the visual image and obtaining a map of zones with the different emissivity of the sample surface, analysis of the thermogram with an assessment of the level of discreteness of the thermogram and the position of the reference points on the image, smoothing of the thermographic image and selection of zones with the different emissivity of the surface of the object under control on the thermogram, followed by noise filtering. Since the results of thermal control are strongly influenced by the shape of the object, the capabilities and effectiveness of the proposed methodology are illustrated on a cylindrical object. The experiment confirmed the validity and correctness of the theoretical statements and allowed us to determine the internal structure of the object under study (different wall thicknesses) and reduce the level of structural interference by 3.6 ˚C. The research shows that the processing of experimental data, which was carried out taking into account the specifics of the thermal and structural characteristics of the objects under control, gives a significant positive result and is an important step towards automating thermal non-destructive testing procedures on the way to implementation in current productionПублікація Зниження рівня завад при тепловому неруйнівному контролі з урахуванням особливостей теплофізичних та морфологічних характеристик об’єктів(Видавничий дім "Патон", 2022) Стороженко, В. О.; Мягкий, О. В.; Орел, Р. П.; Мешков, С. М.Описано характерні для теплового неруйнівного контролю завади та перешкоди, що знижують достовірність отриманих результатів. Запропоновано методику їх зменшення, що складається з двох взаємозалежних етапів. Перший етап полягає у розрахунку і аналізу характеру та рівня очікуваного сигналу за розробленою теплофізичною моделлю на тлі експериментально отриманого рівня завад. За результатами аналізу розрахунків по теплофізичній моделі для обраних зразків найвпливовішою завадою виявилася неоднорідність випромінювальної здатності поверхні зразка. Зменшенню цієї завади присвячений другий етап обробки отриманих даних. Другий етап полягає в обробці термограм температурних полів і включає морфологічний аналіз стану поверхні, фільтрації та зменшення характерних завад та перешкод. Він розділений на чотири практичні процедури. Аналіз візуального зображення та отримання карти зон з різною випромінювальною здатністю поверхні зразка, аналіз термограми з оцінкою рівня дискретності термограми та положенням реперних точок на зображенні, згладжування термографічного зображення та виділення на термограмі зон з різною випромінювальною здатністю поверхні об’єкту контролю, після чого проходить фільтрація завади. Тому що на результати теплового контролю сильно впливає форма об'єкта, можливості та ефективність запропонованої методики проілюстрована на об'єкті циліндричної форми. Експериментально підтверджено, що для вибраного зразка рівень перешкод вдалося знизити до рівня впевненого виділення корисного сигналу на фоні завади.Публікація Reducing the level of interference at thermal non-destructive testing considering the specific thermal physical and morphological characteristics of the object(2022) Storozhenko, V. O.; Meshkov, S. M.; Orel, R. P.; Miahkyi, O. V.Interferences, characteristic for non-destructive thermal testing which reduce the reliability of the results obtained are described. A technique for their reduction is suggested which consists of two interrelated stages. The fi rst stage consists in calculating and analyzing the nature and level of the expected signal according to the developed thermophysical model against the background of the experimentally obtained noise level. According to the results of analysis of calculations using the thermophysical model for the selected samples, the most infl uential interference was the inhomogeneity of the emissivity of the sample surface. The second stage of processing the received data is devoted to reducing this noise. This stage consists in processing of thermograms of temperature fi elds and includes morphological analysis of the surface condition, fi ltering and reducing characteristic noise and interference. It consists of four practical procedures: analysis of the visual image and obtaining a map of zones with diff erent emissivity of the sample surface, analysis of the thermogram with an assessment of the level of discreteness of the thermogram and the position of fi ducial points on the image, smoothing the thermographic image and highlighting zones on the thermogram with diff erent emissivity of the controlled object surface, after which the noise is fi ltered. Since the results of thermal control are strongly infl uenced by the shape of the object, the possibilities and eff ectiveness of the suggested technique are illustrated on a cylindrical object. It has been experimentally confi rmed that for the selected sample, it was possible to reduce the noise level to that of confi dent separation of useful signal against the noise background.Публікація Шляхи підвищення ЕРС напівпровідникових елементів на основі термоелектричних ефектів(ХНУРЕ, 2024) Мягкий, О. В.; Орел, Р. П.; Мешков, С. М.; Стороженко, В. О.У роботі розглянуто розвиток термовольтаичного ефекту у варізонних напівпровідникових багатошарових структурах. Досліджено ефект виникнення електрорушійної сили (ЕРС) у напівпровідникових зразках без ізотипних переходів та бар'єрів типу метал-напівпровідник при їх нагріванні вздовж зразка при термовольтаичному ефекті. Розглянуто можливості отримання стабільної термостимульованої ЕРС у напівпровідникових зразках з неоднорідним складом, зокрема у варізонних напівпровідниках при їх нагріванні. Змодельовано напівпровідник з неоднорідним складом, у якому концентрації носіїв заряду – як електронів, так і дірок, достатньо для виникнення відчутного електричного струму за його збудженні. Розглянуто випадки одиничного варізонного шару напівпровідника та комбінації декількох шарів за різних температурних умов. Проаналізовано виникнення ЕРС і кількісні характеристики цього процесу. Підтверджено, що поява термо ЕРС обумовлюється нерівноважністю стану та неоднорідністю середовища, а також його біполярністю. Показано, що у замкнутому контурі з неоднорідним легуванням та зі змінною шириною забороненої зони виникає ЕРС в умовах однорідного нагрівання всього контуру. Отримано рівняння, яке описує виникнення ЕРС у варізонних напівпровідниках. Для розрахунку теплового поля побудовано теплофізичну модель на основі нестаціонарного рівняння теплопровідності з граничними умовами 2-го та 3-го роду. Використовувана теплофізична модель характеризує двошарову структуру з параметрами, що плавно змінюються. Результати чисельного експерименту дозволили отримати рекомендовані межі температури до роботи розглянутих елементів з урахуванням твердого розчину SiGe і розрахувати величину додаткової ЕРС.Публікація Application of Thermography to Detect Areas of Water Infiltration in the Dam Concrete Foundation(2024) Miahkyi, O.; Meshkov, S.; Orel, R.; Storozhenko, V.This paper introduces a methodology devised for thermographic inspection of concrete technical condition inside concrete dams. Water infiltration into a dam accelerates the processes of concrete degradation, so temperature fields provide important information about the dynamics of these processes. As a result of the thermal imaging survey of the observation gallery at a historic hydraulic structure, a formalized pattern of the temperature field inside the dam was acquired and the locations of temperature anomalies associated with infiltration were identified. At the leakage points, the water temperature differed from the concrete temperature by 1.0–2.9 °C, indicating different rates of water flow through the water wall and the gallery ceiling. The temperature of the gallery areas with increased infiltration was 1–2 °C higher than the 12.7 °C selected as the reference temperature. When recording the temperature fields, the optical axis of the thermal imager was directed along the gallery, and not perpendicular to the surfaces under study, as in construction thermography. To this end, a methodological approach was devised to eliminate distortions of the resulting thermograms caused by the curvature of the gallery and other factors. To remove images of extraneous thermal radiation sources from the thermograms and accurately identify the area under study, a method of shielding a part of the image using special masks was used. The comparative thermography method made it possible to eliminate difficulties in determining the emissivity of the gallery concrete surface. The proposed method of comparative thermography made it possible to compare the intensity of filtration processes in the dam body and to link the current state of the hydraulic structure with the history of its restoration. In general, the thermographic method makes it possible to supplement existing primary natural control with a formalized pattern of temperature field inside the dam.Публікація Reversible luminescent hydrogen peroxide sensors based on CeO2-x and CeO2-x:Eu3+ nanocrystals(B. Verkin Institute for Low Temperature Physics and Engineering of NAS Ukraine, 2024) Maksimchuk, P.; Neuhodov, Y.; Hubenko, K.; Onishchenko, A.; Yefimova, S.; Seminko, V.Hydrogen peroxide (HP) is a widespread industrial chemical widely used for bleaching, cleaning, and disinfection. HP also plays an indispensable role in living organisms being a ubiquitous cell signaling molecule [1] and a substrate or byproduct of a number of enzymes (including catalase, superoxide dismutase, and a number of oxidases and peroxidases) [2]. So, HP sensing is required for reliable quantification of HP content in these systems.Публікація Second-Order Fractals in the Geospace Researches(Astronomy and Space Physics in the Kyiv University, 2023) Chernogor, L. F.; Lazorenko, O. V.; Onishchenko, A. A.According to the non-linear and the system paradigms, many processes generated in open, non-linear, dynamical systems under influence of a powerful source of energy release are appeared to be short-time, ultra-wideband, nonlinear and fractal. The geospace was shown to be a good example of such systems. Many processes caused in geospace by the non-stationary powerful sources of energy release have significant fractal properties. Therefore, the investigations of such properties seems to be actual and interestingПублікація GdVO4:Eu3+ Nanocrystals as catalase mimics for hydrogen peroxide decomposition(Ivan Franko National University of Lviv, 2024) Maksimchuk, P.; Hubenko, K.; Onishchenko, A.; Kavok, N.; Dudetskaya, G.; Seminko, V.; Yefimova, S.Hydrogen peroxide (H2O2) belongs to the family of reactive oxygen species and is vital for many redox metabolic reactions and cellular activities. It plays an important role in maintaining cellular homeostasis and influencing various physiological functions [1]. However, the reaction known as Fenton's reaction, which occurs between H2O2 and Fe2+ ions, is a significant contributor to the oxidation of biomolecules, resulting in the production of highly reactive hydroxyl radicals (•OH). This has led to increased interest in the development of preventive antioxidants that can interact with H2O2 without forming harmful radicals such as •OHПублікація Catalase-like hydrogen peroxide decomposition by GdVO4 :Eu3+ nanocrystals(2024) Maksimchuk, P.; Hubenko, K.; Onishchenko, A.; Seminko, V.; Yefimova, S.Hydrogen peroxide (H2O2) is a member of the reactive oxygen species family and plays a critical role in numerous redox metabolism reactions and cellular processes. It is considered a key component in the homeostatic metabolism of cells, mediating various physiological processes. However, the Fenton reaction between H2 O2 and Fe2+ ions is a major cause of biomolecule oxidation reactions, leading to the formation of highly reactive hydroxyl radicals (•OH). Therefore, there is significant interest in preventive antioxidants that can react with H2O2 without generating free radicals like •OHПублікація Multi-Fractal Analysis in Problems of the Applied Physics(Taras Shevchenko National University of Kyiv, 2023) Chernogor, L. F.; Lazorenko, O. V.; Onishchenko, A. A.According to the non-linear and the system paradigms, many processes generated in open, non-linear, dynamical systems under influence of a powerful source of energy release are appeared to be short-time, ultrawideband, non-linear and fractal. In the paper [1] published one year ago, we have introduced a short review of the existing mono-fractal analysis methods, which can be useful and quitly applicable for solving of the applied physics problems, where there are a lot of such processes and such systems. To investigate their fractal properties more extended, the multi-fractal analysis methods should be applied. Unfortunately, similar the monofractal analysis methods, these methods are often appeared to be quite unknown for the most part of researchers too.Публікація Effect of Hydrogen Peroxide Decomposition on Luminescence and Microstructure of GdVO4:Eu3+ Redox-Active Nanocrystals(Institute of Electronics and Computer Sciences, 2024) Hubenko, K.; Maksimchuk, P.; Klochkov, V.; Onishchenko, A.; Yefimova, S.Публікація Radioprotective Properties of Oxide Nanocrystals(University of Milano, 2024) Hubenko, K.; Maksimchuk, P.; Klochkov, V.; Bespalova, I.; Onishchenko, A.; Demchenko, L.; Yefimova, S.Публікація Fractal analysis in space physics(Taras Shevchenko National University of Kyiv, 2022) Chernogor, L. F.; Lazorenko, O. V.; Onishchenko, A. A.According to the non-linear and the system paradigms, many processes generated in open, non-linear, dynamical systems under influence of a powerful source of energy release are appeared to be short-time, ultrawideband, non-linear and fractal. In applied physics, there are a lot of such processes and such systems. Therefore, to investigate the fractal properties of the signals and processes generated in the open, non-linear, dynamical systems, the set of corresponding methods are needed. Namely such modern and effective methods had been united in fractal analysis. Suddenly, but these methods are often appeared to be quite unknown for the most part of researchers, which work in space physics. No doubt, this state should be changed.Публікація Fractal Analysis in Problems of the Applied Physics(Taras Shevchenko National University of Kyiv, 2022) Chernogor, L. F.; Lazorenko, O. V.; Onishchenko, A. A.For the researchers, a review of the existing mono-fractal analysis methods applied in different branches of modern applied physics is proposed. For each mono-fractal analysis method, some actual references allowing to study the method and to develope corresponding numerical realization are givenПублікація Резонансная кубическая решетка сферических воздушных пузырьков, находящаяся в магнито-диэлектрической среде(Вебер, 2010) Козарь, А. И.Рассматривается решение и анализ задачи о рассеянии плоской электромагнитной волны резонансной кубической решеткой сферических воздушных пузырьков, находящихся в магнитодиэлектрической среде с большим значением диэлектрической и магнитной проницаемостями.Публікація Hydrogen Peroxide Detection Using Reversible Luminescent CeO2-x and CeO2-x:Eu3+ Nanocrystals(Institute of Physics of the National Academy of Sciences of Ukraine, Taras Shevchenko National University of Kyiv Ukrainian, Physical Society, 2024) Maksimchuk, P.; Neuhodov, Y.; Hubenko, K.; Onishchenko, A.; Kavok, N.; Dudetskaya, G.; Kot, Y.; Yefimova, S.; Seminko, V.Hydrogen peroxide (HP) is a prevalent industrial chemical used extensively for bleaching, cleaning, and disinfection. In biological systems, HP acts as a crucial signaling molecule and is involved in various enzymatic processes as a substrate or byproduct, such as those involving catalase, superoxide dismutase, and numerous oxidases and peroxidases [1, 2]. Thus, precise HP sensing is vital for monitoring its concentration in both industrial and biological contextsПублікація Time-Frequency and Fractal Analyses of the Earth's Magnetic Field Variations Appeared During Powerful Geospace Storms Took Place in September 2017(Taras Shevchenko National University of Kyiv Astronomical Observatory, 2021) Chernogor, L.; Lazorenko, O.; Onishchenko, A.According to the non-linear and the system paradigms, many processes generated in open, non-linear, dynamical systems under influence of a powerful source of energy release are appeared to be short-time, ultrawideband, non-linear and fractal.Публікація Comparative analysis of models for short-term forecasting of electricity consumption(2024) Korablyov, M.; Kobzev, I.; Chubukin, O.; Antonov, D.; Polous, V.; Tkachuk, O.Forecasting electricity consumption is an urgent task, and the solution significantly affects the efficiency of the use of energy resources. The paper considers short-term forecasting of electricity consumption, which predicts the amount of energy that will be used in a short period, from several hours to several days in advance. There are various short-term forecasting models, so it is important to reasonably choose a model that provides analysis and effective forecasting of electricity consumption to optimize the use of energy resources. The purpose of the work is to analyze the main forecasting models, such as statistical models (autoregressive model, moving average, exponential smoothing, moving average with autoregression and integration) and deep learning models (artificial neural network, recurrent neural network, long short-term memory, transformer), indicating their advantages and disadvantages, and choosing the best of them. The experimental results of a comparative analysis of power consumption forecasting models are presented, which showed that the transformer model was 1.5% - 2% more effective in power consumption forecasting according to various metrics. Its higher level of accuracy, reflected in low error values and high coefficient of determination, indicates its high adaptability to the dynamics of electricity consumption.Публікація Immune Model for Controlling Characters in Computer Games(CEUR Workshop Proceedings (CEUR-WS.org), 2023) Korablyov, M.; Fomichov, O.; Chubukin, O.; Antonov, D.; Dykyi, S.The rapid development of information technologies led to the emergence of new opportunities for game software developers. In the field of game application development, a large number of platforms and patterns of architecture development, as well as game environments, have appeared, which allow simplifying and automating the process of development and deployment of the game software. The game application used in the work simulates a futuristic space world where the player interacts with other characters in a free game space. An analysis of game resources, which can be controlled by the player and other game characters, has been carried out. The main features of the behavior of game characters controlling spaceships on the map of the game world are defined. The task of controlling the behavior of characters in game software can be considered as a classification problem, for which it is proposed to use artificial immune systems. Among the existing immune models, the most promising for practical application is the artificial immune network model, which was chosen as the basis for creating a model for controlling the behavior of characters in computer games. But it cannot be used to solve the problem of managing game characters without additional modifications. A modified model of the immune network – behavioral aiNET (baiNET) was proposed, which can be used to solve the problem under consideration. The software implementation of the game software tool, in which the control of the game characters is carried out using the baiNET model, has been completed. Experimental studies were carried out with different numbers of game characters on different-sized maps of the game world, which showed that the proposed baiNet immune model is effective and simple to implement and modify. This makes it possible to use it to control characters in games of other genres.Публікація Peculiarities of Cs1-xRbxCu2Cl3 Solid Solutions Absorption Spectra(Eskisehir Technical University, 2023) Kovalenko, O.; Yunakova, O.; Yunakov, N.