https://repository.hneu.edu.ua/handle/123456789/10077 2026-06-14T14:26:21Z 2026-06-14T14:26:21Z Михайлова Є. О. Мороз М. О. https://repository.hneu.edu.ua/handle/123456789/40706 2026-06-14T09:45:05Z 2026-01-01T00:00:00Z

Назва: Вплив органічних розчинників на довкілля: екологічні ризики та шляхи мінімізації Автори: Михайлова Є. О.; Мороз М. О. Короткий огляд (реферат): Розглянуто основні екологічні аспекти використання органічних розчинників та їхній вплив на атмосферне повітря, водні ресурси й ґрунти. Проаналізовано джерела забруднення довкілля леткими органічними сполуками та наслідки їх поширення для екосистем і здоров’я людини. Висвітлено сучасні підходи до зменшення негативного впливу органічних розчинників, зокрема застосування екологічно безпечних технологій і «зелених» розчинників.

2026-01-01T00:00:00Z Dymertsov D. https://repository.hneu.edu.ua/handle/123456789/40644 2026-06-11T12:32:29Z 2026-01-01T00:00:00Z

Назва: Computer simulation of gas-dynamic processes: a one-dimensional approach Автори: Dymertsov D. Короткий огляд (реферат): The relevance of this work derives from the need for effective information technologies and software tools for modeling gas-dynamic processes in technical systems. Under modern conditions, the use of full-scale multidimensional models is associated with significant computational costs and complexity of software implementation, which limits their application in practical problems. In this context, one-dimensional models gain particular importance as a basis for developing optimized numerical solution algorithms that provide a reasonable balance between accuracy, computational efficiency, and implementation complexity. The objective of the study is to develop a one-dimensional mathematical model and a software package for numerical simulation of thermogasdynamic processes in flow elements of technical systems, as well as to verify and analyze the accuracy of the developed model. The aim of the study is to develop, implement, and verify a unified method for investigating gas-dynamic processes based on one-dimensional mathematical modeling using modern numerical analysis techniques. Special attention is paid to the development of efficient computational algorithms that take into account key physical processes (gas flow, heat and mass transfer, energy transformations, turbulence, and hydraulic losses), as well as ensure stability, convergence, and computational efficiency in software implementation. The object of the study is the processes of numerical modeling of gas-dynamic phenomena in flow elements of technical systems (pipelines, channels, heat exchangers, piston units), which are characterized by unsteady behavior, wave effects, and intensive heat and mass transfer processes. The subject of the study is methods based on a generalized one-dimensional mathematical model for calculating gas-dynamic processes in flow elements of technical systems. The results of the study showed that methods for improving numerical stability and reducing computational errors have been investigated and implemented, which ensured stable operation of algorithms in modeling unsteady gas-dynamic processes. The developed model is implemented as a software package designed for computational experiments and further analysis of simulation results. The performed verification, based on comparison with known analytical, numerical, and experimental data, confirmed the correctness, accuracy, and efficiency of the proposed algorithms. The conclusion confirms the feasibility of using one-dimensional computational models as an effective tool for computer modeling of complex physical processes. The proposed approach can be applied in the development of modern information technologies and in further scientific research in the field of gas dynamics and thermophysics, while the relative error does not exceed 5%.

2026-01-01T00:00:00Z Riadova L. O. https://repository.hneu.edu.ua/handle/123456789/40643 2026-06-11T12:27:28Z 2026-01-01T00:00:00Z

Назва: Choreographic training in artistic gymnastics Автори: Riadova L. O. Короткий огляд (реферат): The research is aimed at studying the features of choreographic training of gymnasts in artistic gymnastics at different the stages of long-term sports training. It has been established that choreographic training is mandatory and one of the most important components of the system of long-term sports training of gymnasts. It ensures not only technical perfection in the execution of the elements, but also aesthetic expressiveness, artistry and emotional richness of programs. It was found that the features of choreographic training differ significantly depending on the stage of long-term sports training: from a playful and improvisational nature at the stage of initial training to highly artistic, individually developed compositions at the stage of maximum realization of individual capabilities. At the stage of preservation higher sports skills, it is aimed at maintaining the expressiveness and stability of movements; at the stage of gradual decline in achievements, it is aimed at preserving grace and plasticity and at the stage of leaving the sport of higher achievements, it is transformed into recreational and health-improving activities. At each stage of long-term sports training, the tasks, means, volume and intensity of choreographic work change. It has been established that choreographic training in artistic gymnastics must be clearly differentiated, stage-oriented and integrated into the overall system of sports training. Its systematic and competent implementation is a necessary condition for gymnasts to achieve high sports results.

2026-01-01T00:00:00Z Novikov F. Novikov D. Zhovtobryukh V. Yermolenko O. Ivashura A. https://repository.hneu.edu.ua/handle/123456789/40640 2026-06-11T07:51:14Z 2026-01-01T00:00:00Z

Назва: Theoretical Substantiation of the Conditions for Reducing Cutting Force and Temperature During Blade and Abrasive Processing Автори: Novikov F.; Novikov D.; Zhovtobryukh V.; Yermolenko O.; Ivashura A. Короткий огляд (реферат): The aim of the work is to create a generalized mathematical model for determining cutting force, temperature, and energy intensity of processing, as well as to substantiate the conditions for their reduction during blade and abrasive processing. It is shown that the main condition for their reduction is to reduce to zero the angle of action, which is equal to the difference between the conditional angle of friction that occurs in the processing zone and the positive rake angle of the tool. In this case, the energy intensity of processing is equal to the compressive strength of the processed material, and the cutting force and temperature become the minimum possible, depending on the energy intensity of processing. This condition can be implemented during cutting with blade tools, since during grinding the conditional rake angle of the cutting grains is negative, and the angle of action exceeds the value of 45о. For this, the conditional angle of friction and the rake angle of the tool (due to its design) must be approximately equal. It has been experimentally established that this is achieved during high-speed cutting with prefabricated carbide blade tools with increased physical and mechanical properties, which significantly exceed traditional carbide cutting tools in terms of service life before blunting. As a result, it was possible to significantly increase productivity and ensure high quality of processing. On this basis, effective technological processes for processing parts of hydraulic systems have been developed.

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