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DEVELOPMENT OF A SYSTEM FOR CONTINUOUS AUTOMATIC MONITORING OF THE CABLE ROPE CONDITION

STRENGTH OF MATERIALS 2022年第5期54卷 825-840页

作者： Belmas, I., V Bilous, O., I Tantsura, G., I Shvachka, A., V Dniprovsky State Tech Univ Kamyanske Ukraine

The safety of bridge structures in operation should be ensured by periodic inspections and control checks. During the inspection of structures, the operational reliability of transport structures is assessed, and recommendations are made to eliminate the detected defects. In the case of imperfect methods for monitoring the stress state of load-bearing elements, unnecessary repairs can be assigned and performed, which can lead to an increase in the risk of accidents and inefficient use of budget funds. To date, the determination of the stress state is not included in the list of works performed during a detailed inspection of cables. This is caused by the low degree of study of existing nondestructive testing methods, the lack of developed and normatively fixed methods for their application, and a number of other reasons, including high labor intensity, low accuracy, narrow range of application and others. The main method used at the time of writing, a nondestructive method for monitoring the stress state of steel wires of cable ropes, is considered. At present, one of the most reliable and technologically simple methods for obtaining transmission and processing is an electrical signal. Its advantages make it possible to easily and efficiently inspect the ropes from different sides, which is very important when designing the device. The method of nondestructive testing of stress in steel cables is investigated. The dependence between the electrical resistance of steel measured on alternating current in the surface layer is determined. The results show that the violation of the integrity of the cables provides an electrical signal, the value of which depends on the state of each cable of the rope, the design of the rope, and the level of signal change that occurs in the event of damage to one of the cables. The factors influencing the dependence of electrical resistance on the mechanical parameters of the cable rope are revealed. Practical recommendations for the use

关键词： rubber cable rope electrical resistance control cable rope cable mathematical model signal

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Using Diamond Grinding Powders with Combined Coatings on Diamond Grain Surfaces in Abrasive Tools

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JOURNAL OF SUPERHARD MATERIALS 2024年第3期46卷 238-243页

作者： Lavrinenko, V. I. Poltoratskyi, V. G. Pasichnyi, O. O. Solod, V. Yu. Natl Acad Sci Ukraine Bakul Inst Superhard Mat UA-04074 Kiev Ukraine Dniprovsky State Tech Univ UA-51918 Dnipro Ukraine

A technological process has been developed for forming coatings on the surface of diamond grains using two and three components: soluble boron oxide (B2O3) and insoluble aluminum oxide (Al2O3) or insoluble carbide (B4C, SiC, TiC). To achieve guaranteed increases in the wear resistance of diamond wheels when grinding hard alloys, it is necessary to apply a coating of boron oxide and boron carbide (B2O3 + B4C) to the surface of the diamond grains. The positive effect of such a coating on the surface of the diamond grains is more pronounced under increased force and heat loads in the grinding zone. The holding capacity of the processed rough surface in terms of the t50 support surface curve parameter is preferable when the surface of diamond grains in diamond powder wheels AS6 125/100 is coated with a mixture of B2O3 + B4C. Thus, for diamond grains, considering both the wear resistance of diamond wheels and surface roughness parameters, it is recommended to use diamond grains with a surface coating of B2O3 + B4C in wheels for grinding hard alloys.

关键词： combined protective coatings diamond grinding powders the surface of diamond grains wear resistance of diamond wheels roughness of the treated surface

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Investigating the Presence of Surface Adsorbed Water in Modern Low-Strength Diamond Grains as a Factor Influencing the Contact Zone during Grinding

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JOURNAL OF SUPERHARD MATERIALS 2025年第1期47卷 46-53页

作者： Lavrinenko, V. I. Smokvyna, V. V. Ilnytska, H. D. Starik, S. P. Tyshchenko, V. A. Natl Acad Sci Ukraine Bakul Inst Superhard Mat UA-04074 Kyiv Ukraine Dniprovsky State Tech Univ Minist Educ & Sci Ukraine UA-51900 Kamianske Dnipropetrovsk Ukraine

The presence of adsorbed water and hydroxyl groups on the actual surface of modern diamond grinding powders with low strength (grades AC6-AC32) was investigated. By preliminarily separating diamond grinding powders into magnetic, nonmagnetic, and initial fractions, a fraction with the highest amount of water on the surface of the diamond grains can be identified-the magnetic fraction. The Ni-Al composite coating on the diamond surface, as well as the coating with carbon nanotube additives, contribute to the formation of a more developed surface compared to the initial uncoated samples, as evidenced by the greater presence of water.

关键词： diamond grains adsorbed water hydroxyl groups diamond grain surface magnetic fraction composite coating

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Molecular dynamic simulation of multicomponent CoCrFeNiMn high-entropy alloy thin film deposition

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MOLECULAR CRYSTALS AND LIQUID CRYSTALS 2025年

作者： Kushnerov, Oleksandr I. Ryabtsev, Sergey I. Bashev, Valerij F. Oles Honchar Dnipro Natl Univ Dept Expt Phys 72 Nauky Ave UA-49010 Dnipro Ukraine Dniprovsky State Tech Univ Dept Condensed Matter Phys Kamianske Ukraine

Molecular dynamics simulations were used to study the deposition and growth of a thin film of high-entropy CoCrFeMnNi alloy on an Al(100) substrate. Interatomic interactions were modeled using Morse potentials, which were developed with mixing rules adopted for regular solutions. A total of 50000 atoms with an incident energy of 10 eV were deposited for 100 ns, forming a film with a thickness of 6.1 nm. The resulting film exhibited face-centered cubic, body-centered cubic, hexagonal close-packed, and amorphous phases. Radial distribution function analysis determined the nearest neighbor distances and lattice parameters, which showed good agreement with experimental data.

关键词： CoCrFeMnNi high-entropy alloy molecular dynamics Morse potential thin film

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An efficient parallelization technique for the coupled problems of fluid, gas and plasma mechanics in the grid environment

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SCIENTIFIC REPORTS 2025年第1期15卷 1-15页

作者： Zinchenko, Andrii Fernandez-Gamiz, Unai Redchyts, Dmytro Gorna, Olga Bilousova, Tetiana Natl Acad Sci Ukraine Inst Transport Syst & Technol Dnipro Ukraine Univ Basque Country Vitoria Spain Kherson State Agrarian & Econ Univ Kherson Ukraine Dniprovsky State Tech Univ Kamianske Dnipropetrovsk Ukraine

The development of efficient parallelization strategies for numerical simulation methods of fluid, gas and plasma mechanics remains one of the key technology challenges in modern scientific computing. The numerical models of gas and plasma dynamics based on the Navier-Stokes and electrodynamics equations require enormous computational efforts. For such cases, the use of parallel and distributed computing proved to be effective. The Grid computing environment could provide virtually unlimited computational resources and data storage, convenient task launch and monitoring tools, graphical user interfaces such as web portals and visualization systems. However, the deployment of traditional CFD solvers in the Grid environment remains very limited because basically it requires the cluster computing architecture. This study explores the applicability of distributed computing and Grid technologies for solving the weak-coupled problems of fluid, gas and plasma mechanics, including techniques of flow separation control like using plasma actuators to influence boundary layer structure. The adaptation techniques for the algorithms of coupled computational fluid dynamics and electrodynamics problems for distributed computations on grid and cloud infrastructure are presented. A parallel solver suitable for the Grid infrastructure has been developed and the test calculations in the distributed computing environment are performed. The simulation results for partially ionized separated flow behind the circular cylinder are analysed. Discussion includes some performance metrics and parallelization effectiveness estimation. The potential of the Grid infrastructure to provide a powerful and flexible computing environment for fast and efficient solution of weak-coupled problems of fluid, gas and plasma mechanics has been shown.

关键词： Parallelization Computational fluid dynamics Coupled problems Fluid mechanics

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Performance Indicators of Grinding Tools with Cubic Boron Nitride Grains with Combined Wear-Resistant Coatings

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JOURNAL OF SUPERHARD MATERIALS 2024年第4期46卷 322-326页

作者： Lavrinenko, V. I. Poltoratskyi, V. G. Pasichnyi, O. O. Solod, V. Yu. Natl Acad Sci Ukraine Bakul Inst Superhard Mat UA-04074 Kiev Ukraine Dniprovsky State Tech Univ Minist Educ & Sci Ukraine UA-03057 Kamianske Ukraine

We investigated the effect of surface coatings on cubic boron nitride (cBN) grains regarding tool wear resistance and processing efficiency. At a low processing rate (50 mm(3)/min), the wear resistance enhancement factor was 1.66 for the B2O3 + CeO2 coating. Conversely, at a higher processing rate (200 mm(3)/min), the wear resistance enhancement factor decreased to 1.13 for the B2O3 + B4C coating. The study demonstrated that under these processing conditions, surface coating of cBN grains with a combination of oxide and carbide (B2O3 + SiC) is preferable. This preference is based on improved grinding wheel wear resistance and reduced surface roughness (R-a) of the machined surface. Furthermore, at increased grinding efficiency, any coating on cBN grain surfaces decreases the t50 parameter, thereby decreasing the holding capacity of the rough surface generated during grinding with such wheels.

关键词： combined wear-resistant coatings grinding tools cubic boron nitride grains performance indicators

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Heavy metal ions removal from an aqueous solution using an adsorbent derived from walnut shell: Equilibrium, kinetic and thermodynamic studies

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DESALINATION AND WATER TREATMENT 2025年 321卷

作者： Ivanchenko, Anna Soroka, Olga Yelatontsev, Dmytro Panasenko, Vladimir Dniprovsky State Tech Univ 2 Dniprobudivska St UA-51918 Kamianske Ukraine Natl Acad Sci Ukraine MS Poliakov Inst Geotech Mech 2 Simferopolska St UA-49005 Dnipro Ukraine State Inst State Sci Res & Design Inst Basic Chem Myronosytska st 25 UA-61002 Kharkiv Ukraine

A modified adsorbent for the removal of heavy metal ions (HMI) Pb-2(+), Cd2+, Cu2+, Ni2+, and Co2+ was synthesized from carbonized walnut shells (Juglans regia L.) pretreated with sodium carbonate (Na2CO3). By selecting the optimal parameters for the chemical activation of the raw materials (temperature, time, and concentration of Na2CO3), a 19-fold increase in the specific surface area and a 14-fold increase in iodine number were achieved. The obtained adsorbent was characterized by an enhanced porous structure and doubled acidic surface functional group content, which provided high-efficiency HMI removal (>85 %). The maximum adsorption capacity of 95-98 mg g(-1) was observed at pH 6.5, with a 60-minute contact time and an adsorbent dosage of 5 g dm(-3). The adsorption process follows the Langmuir isotherm, is governed by pseudo-second-order kinetics, and is spontaneous, endothermic, and physical in nature. HMI removal comprised physical interactions between the acidic functional groups of the adsorbent and the adsorbate via the formation of hydrogen bonds, which was facilitated by the formation of hydroxides at the corresponding pH. When HNO3 is used for regeneration, the proposed adsorbent can be reused for up to five sorption/desorption cycles, maintaining a satisfactory removal efficiency more than (>80 %). The present findings highlight the prospects of the developed method of processing walnut shells into an effective HMI adsorbent and indicate directions for further research on eco-friendly processing of plant biomass into cost-effective materials for large-scale wastewater treatment.

关键词： Walnut shell Sodium carbonate Chemical activation Heavy metal ion Adsorption

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Criterion for Choosing the Integration Step Size for Simulation of Sliding Modes in Electric Drives 15

Criterion for Choosing the Integration Step Size for Simulat...

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15th International Conference on Advanced Trends in Radioelectronics, Telecommunications and Computer Engineering (TCSET)

作者： Derets, Oleksandr Sadovoi, Oleksandr Derets, Yevgeniya Derets, Hanna Dniprovsky State Tech Univ Elect Engn & Electromech Dept Kamyanske Ukraine Dniprovsky State Tech Univ Higher & Appl Math Dept Kamyanske Ukraine

ISBN: (纸本)9781728155661

Application of numerical integration methods with automatic step determination in modeling relay control systems poses a number of difficulties, which makes it reasonable to ground a choice of a fixed step size. Traditional criteria are based on the correlation of the step with the minimum time constant of the control object. They do not provide an unambiguous choice of the step necessary for reliable modeling of sliding modes. The solution to this problem was obtained by redefining the minimum time constant of the control system, taking into account the features of the functioning of electric drives.

关键词： sliding mode electric drive step size time constant

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Assessment of the Interaction between Crankcase Gases and Engine Oil

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JOURNAL OF MACHINERY MANUFACTURE AND RELIABILITY 2021年第4期50卷 364-369页

作者： Kubich, V., I Cherneta, O. G. Bokarov, V., I Leshchenko, E. P. Yurov, V. M. Oleshko, V. S. Zaporizhzhia Polytech Natl Univ UA-69063 Zaporizhzhia Ukraine Dniprovsky State Tech Univ UA-51900 Kamianske Dnipropetrovsk Ukraine Buketov Karaganda Univ Karaganda 100012 Kazakhstan Moscow Inst Aviat Technol Moscow 125993 Russia

Topical aspects of assessing the effect of crankcase gases of an internal combustion engine on the operational properties of engine oil taking into account its service life are considered. For a mathematical description of the change in the condition of engine oil, a complex criterion for assessing oil operational properties and a criterion for assessing the saturation with crankcase gases are proposed. At the same time, it has been found that the change in each of the criteria depending on the service life and engine rotational speed can be approximated by an exponent at a confidence level amounting to 0.95. The parameters of the proposed criteria have been assessed. It is shown that these criteria can be used jointly for diagnosing the condition of engine oil. It has been established preliminarily that the detailed service life of the engine affected by the properties of engine oil can be determined by the simulated time of interaction between the oil and the crankcase gases.

关键词： engine oil crankcase gases pressure viscosity criterion service life

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Development of a Sorption technology for Separating Uranium and Rare-Earth Elements

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ATOMIC ENERGY 2020年第6期128卷 356-361页

作者： Elatontsev, D. A. Korovin, Yu F. Mukhachev, A. P. Dniprovsky State Tech Univ DSTU Kamianske Ukraine Ukrainian Natl Acad Sci Polyakov Inst Geotech Mech Dnipro Ukraine

The results of laboratory experiments on the sorption separation of uranium and rare-earth elements from nitrate-phosphate solutions on a solid extractant with an active phase in the composition of the heter-oradical phosphine oxide and di-(2-ethylhexyl)phosphoric acid are reported. This extractant was used to attain high capacity and degree of extraction of uranium from solutions with initial uranium concentration <0.5 g/dm(3). The following metrics were studied in the process of sorption concentration of uranium: sorption capacity, kinetics of the sorption process, number of sorption stages, and desorption conditions. The optimal sorption conditions giving high selectivity in terms of uranium and the degree of separation of uranium and rare-earth elements were determined.

关键词： Sorption

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