DSpace Зібрання:https://dspace.mnau.edu.ua/jspui/handle/123456789/249862026-10-27T22:25:28Z2026-10-27T22:25:28ZRestoration of degraded soils in a military-affected region in the South of Ukraine based on biologisationШебанін, В’ячеслав СергійовичShebanin, VyacheslavРешетілов, Георгій ОлександровичReshetilov, GeorgiyДробітько, Антоніна ВікторівнаDrobitko, Antoninahttps://dspace.mnau.edu.ua/jspui/handle/123456789/268742026-09-29T05:43:18Z2026-01-01T00:00:00ZНазва: Restoration of degraded soils in a military-affected region in the South of Ukraine based on biologisation
Автори: Шебанін, В’ячеслав Сергійович; Shebanin, Vyacheslav; Решетілов, Георгій Олександрович; Reshetilov, Georgiy; Дробітько, Антоніна Вікторівна; Drobitko, Antonina
Короткий огляд (реферат): Background: This study was motivated by the need to restore soils degraded by military operations, accompanied by compaction,destruction of structure and contamination with heavy metals, which reduce the productivity and ecological functioning ofagroecosystems. The aim of the work was to evaluate the effectiveness of using microbial preparations and green manure cropsseparately and in combination to improve the condition of ordinary chernozem. Methods: The study involved a field experimentwith four treatment options: control; application of the “Azogran” biological preparation; green manure with a mixture of vetch andmustard; and a combination of these, and determination of the content of heavy metals in the soil and their biological activity.Results: The study found that the combined option provided the most positive changes: density decreased from 1.52 ± 0.03 to1.28 ± 0.02 g/cm3; the measured humus-related organic matter indicator increased from 2.1 ± 0.2 to 2.8 ± 0.1%; acidity changedfrom 5.8 ± 0.2 to neutral 6.7 ± 0.1; and the content of available, Chirikov-extractable phosphorus and potassium, reported asP2O5 and K2O, increased by 30.0 and 22.0%, respectively. Biological activity increased significantly: dehydrogenase activitydoubled, and basal respiration exceeded the control by 62.3%. It was also found that the concentrations of mobile forms of lead,cadmium, zinc and nickel decreased by 25.0–32.0%, which was accompanied by a 2.5-fold decrease in the phytotoxicity ofaqueous extracts. Conclusions: The data obtained demonstrate that the combination of the biological product with green manureresulted in synergistic improvements, simultaneously improving the physicochemical and biological properties of the soil andreducing the accumulation of metals. The practical significance of the study lies in confirming the possibility of using this approachas an affordable, environmentally safe and effective way to restore land damaged by military equipment.2026-01-01T00:00:00ZAnalysis of methods for diagnosing asynchronous electric motors used in agricultureСуковіцина, Ірина МиколаївнаSukovitsyna, IrynaВахоніна, Лариса ВолодимирівнаVakhonina, Larisahttps://dspace.mnau.edu.ua/jspui/handle/123456789/267972026-09-14T06:52:49Z2026-01-01T00:00:00ZНазва: Analysis of methods for diagnosing asynchronous electric motors used in agriculture
Автори: Суковіцина, Ірина Миколаївна; Sukovitsyna, Iryna; Вахоніна, Лариса Володимирівна; Vakhonina, Larisa
Короткий огляд (реферат): This study aimed to examine methods for diagnosing asynchronous electric motors in order to determine their effectiveness in detecting various types of faults. The research methodology involved an analysis of the effectiveness of diagnostic methods for electric motors, including vibration diagnostics, infrared thermography, noise diagnostics, and electrical diagnostics. This analysis was conducted based on a comparative assessment of their informativeness in detecting faults. The fundamental principles of the diagnostic methods and their physical bases, as well as their advantages and limitations in the context of detecting defects such as rotor imbalance, bearing damage, winding short circuits, component overheating, and other typical faults, were identified. In the analysis of electrical diagnostic methods, their versatility was noted, enabling the detection of a wide range of defects through the analysis of changes in electrical signals. It was observed that the Fast Fourier Transform method is optimal for static conditions, whereas the Short-Time Fourier Transform provides the capability to analyze dynamic changes, and the Gabor Transform allows for the detection of subtle signal changes. The results obtained provide a scientific foundation for optimizing the process of diagnosing asynchronous electric motors and ensuring their more effective use in industrial and agricultural settings.
Опис: Повний текст статті доступний з сайту видавця за посиланням: https://www.tandfonline.com/doi/full/10.1080/02533839.2026.27240762026-01-01T00:00:00ZNumerical and Experimental Analysis of Free Vibrations of Thick-Walled Cylindrical ShellGrigorenko, AlexanderMüller, WolfgangBorysenko, MaksymБойчук, Олена ВолодимирівнаBoychuk, Olenahttps://dspace.mnau.edu.ua/jspui/handle/123456789/266282026-07-13T06:06:00Z2026-01-01T00:00:00ZНазва: Numerical and Experimental Analysis of Free Vibrations of Thick-Walled Cylindrical Shell
Автори: Grigorenko, Alexander; Müller, Wolfgang; Borysenko, Maksym; Бойчук, Олена Володимирівна; Boychuk, Olena
Короткий огляд (реферат): Free vibrations of an isotropic thick-walled circular cylindrical shell with one end rigidly clamped, and the other free, are investigated numerically and experimentally. The natural frequencies and corresponding mode shapes are determined using the finite element method within a three-dimensional elasticity formulation, employing solid finite elements. The article focuses on constructing a reliable finite element model, including selecting element types and mesh density based on accuracy, convergence, and computational efficiency. In the article, solve a test problem to verify the numerical model and present a detailed convergence analysis. An experimental study of free vibrations based on stroboscopic interferometry, which allows full-field visualization of vibration mode shapes and determination of natural frequencies with sufficient accuracy. A comparison between numerical and experimental results demonstrates good agreement, confirming the reliability of the proposed modeling approach. The research study has been used in the design and analysis of thick-walled cylindrical shell structures in engineering applications, as well as for validating numerical and analytical methods for the vibration analysis of shell systems.2026-01-01T00:00:00ZStudy of Deep Subsurface Fatigue Degradation in Rolling and Sliding Tribocontacts under Variable LoadingМарченко, Дмитро ДмитровичMarchenko, Dmytrohttps://dspace.mnau.edu.ua/jspui/handle/123456789/263502026-06-29T06:35:37Z2026-01-01T00:00:00ZНазва: Study of Deep Subsurface Fatigue Degradation in Rolling and Sliding Tribocontacts under Variable Loading
Автори: Марченко, Дмитро Дмитрович; Marchenko, Dmytro
Короткий огляд (реферат): The paper evaluates the effectiveness of soft gas nitriding of alloyed structural steels 38KhMYuA, 38KhN3MA, and 38KhN3MFA, used in highly loaded gear transmissions, and establishes the limits of application of thin nitrided layers in terms of contact fatigue. The studies are conducted after nitriding at a temperature of 580°C and a duration of 7 hours using microhardness testing, layer-by-layer chemical analysis by high-temperature gas analysis, X-ray structural analysis, and contact fatigue testing of rollers simulating rolling and sliding conditions, typical for helical gearing. It is found that soft nitriding ensures the formation of a hardened layer 0.18–0.25 mm thick with a microhardness of 4.8–5.5 GPa while maintaining a ductile core with a hardness of 240–260 HB. It is shown that under elevated contact stresses, failure of nitrided samples initiates in the subsurface layers and develops via a deep contact fatigue mechanism, accompanied by the formation of deep spalling and a so-called white etching area. The results obtained demonstrate the limited effectiveness of thin nitrided layers under high contact loads and point to the feasibility of using materials with thicker hardened layers (0.8–1.2 mm) or design and technological solutions aimed at reducing contact stress and increasing the service life of gears.
Опис: Повний текст доступний з сайту видавця за посиланням: https://link.springer.com/article/10.3103/S10683666267001212026-01-01T00:00:00Z