Інститут Шосткинський (ШІ)
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Item Production of plasma-activated water for agricultural purposes(Сумський державний університет, 2025) Petrov, S.V.; Bondarenko, S.G.; Shakhnovsky, A.M.; Sanginova, O.V.; Roshanpour, Sh.In recent decades, the world has undergone revolutionary changes due to the rapid growth of the global population. As a consequence of this population increase, there is a high demand for food, water, and energy resources. Therefore, sustainable crop production and food security are critical issues for modern society. The use of nitrogen fertilizers is one of the solutions to the problem of food security.Item Fundamental and applied aspects of pesticide destruction technologies in water(Сумський державний університет, 2025) Krymets, G.V.; Kostenko, A.V.; Nikitina, O.A.Pollution of water resources by toxic chemicals, especially pesticides, has reached a global scale, posing a significant threat to the environment and human health. The problem is exacerbated by the fact that most modern pesticides are resistant to natural degradation, highly toxic, and capable of bioaccumulation. According to the Stockholm Convention, the group of particularly hazardous substances includes aldrin, chlordane, dieldrin, endrin, heptachlor, hexachlorobenzene, mirex, toxaphene, and DDT. All of them are characterized by environmental persistence and are listed as persistent organic pollutants (POPs) [1, 2].Item Mathematical Model of a Square Waveguide Polarizer with Diaphragms(Journal of Microwaves, Optoelectronics and Electromagnetic Applications, 2021) Булашенко, Андрій Васильович; Bulashenko, Andrii Vasylovych; Piltyay, S.; Bulashenko, O.The development of new mathematical model for guide polarization converter with diaphragms was carried out in the research by the method of wave matrices. In addition, numerical modeling of the performance of a polarizer with diaphragms is made by simulating the propagation of the fundamental modes with perpendicular linear polarizations. The wave matrix model was obtained by splitting the polarizer into separate structural elements. Each element was described by its own wave transmission matrices. As a result, a general wave scattering matrix was formed. Based on the elements this matrix the electromagnetic characteristics of the considered polarizer were obtained theoretically. In particular, complex reflection and transmission coefficients were calculated. Their modules and phases were analyzed in the frequency interval 10.7–12.8 GHz. To check the correctness of the obtained results an independent numerical simulation was carried out applying the finite element methodology in the frequency interval. The results of both approaches are in good agreement. The engineered converter of polarization with four diaphragms provides a reflection coefficient modulus of less than 0.14 and a transfer coefficient modulus of more than 0.99 for two orthogonal types of polarizations. As a result, a rigorous mathematical method was developed to analyze the elements of the scattering matrix of a waveguide polarizer with diaphragms. It can be used for the development of new broadband waveguide polarizers and waveguide filters based on diaphragm elements.Item Kinds of sorbents based on carbon and their properties(Сумський державний університет, 2021) Svirska, S.E.; Ivanenko, I.M.; Fedenko, Yu.M.Most of industrial adsorption processes are based on selective absorption of specific components of the gas-vapor mixture flow. During the absorption of gas or vapor, adsorption capacity depends on the type of sorbent, its porous structure, the nature of the substance absorbed is its partial pressure and temperature [1]. In real process of the purification and separation of gases, influence of adsorption of bulk gas and other impurities, and kinetic factors may cause the need to make adjustments in calculation of the adsorption capacity, which was initially determined by isotherms of pure components. However, in all real adsorption process, curve of thermodynamic equilibrium is the main comparative characteristics of different types of adsorbents and it determines the choice of optimal operating conditions of the process. Simultaneously, the adsorption isotherm is a source of information about the structure of the adsorbent, adsorption heat and several other physic-chemical and technological characteristics. C. Brunauer [1] highlighted five main types of adsorption isotherms, which are presented in Pic. 1. In the case of technical adsorbents, type I can be characterized as microporous adsorbents that contain virtually no transient pores. Initial bulging area of type II and IV isotherms indicate presence of macro pores with more or less substantial amount of micro pores in conjunction. Less steep initial ascent isotherm curves can be explained by mono- and multimolecular adsorption only for adsorbents with transitional porous type. Initial curved section isotherms types III and V, which are rarely found, are common for adsorbent-adsorbate systems, when interaction of molecules of adsorbate with an adsorbent much less than intermolecular interaction between adsorbate molecules, for example, caused by a presence of hydrogen bonds. The first fundamental equation of adsorption isotherm was Langmuir’s equation. It is based on the assumption that the adsorption localized and occurs at active centers with the equal energy. They situated relatively rarely on the surface of the adsorbent. Consequently, the interaction between adsorbed molecules is absent. Each active center can adsorb only one molecule. According to this theory, with increasing of pressure, the part of solid surface, which is covered with molecules of adsorbate, increase. After reaching saturation pressure throughout the surface a monolayer of adsorbate is formed [2,3]. The equation of Langmuir, and hence the method for determining the surface area can be applied to systems in which the process is not complicated by multimolecular adsorption, adsorption in micro pores and capillary condensation. To such systems can be attributed the case of adsorption of gases at temperatures above the critical on nonporous or adsorbents with large pores. Despite this limitation, the equation of Langmuir commonly used in technical adsorption. Brunauer, Emett and Teller [4,5] in justifying theory multimolecular adsorption accepted that, despite the change in the total process model, the behavior of each adsorbed layer separately consistent with the concept Langmuir, adsorption localized and occur in the absence of interaction between the molecules of adsorbate. Each adsorbed layer generally obeys the Langmuir’s equation. To create the equation of multimolecular adsorption, the authors started from the point that the rate of condensation of molecules on a clean surface is equal to the evaporation rate on the first layer. Similar assumptions made when comparing the rate of condensation in each of the previous and the evaporation rate in each subsequent layer.Item Detection of picric acid in solutions(Sumy State University, 2021) Fabin, M.2,4,6-trinitrophenol, also known as picric acid (PA), was a widely used explosive, including during the Boer War [1] and World War I [2]. In the interwar period, the military use of PA began to be abandoned and began to replace it with 2,4,6- trinitrotoluene (TNT). Despite lower sensitivity and difficult access to its substrates in the interwar period, TNT provided much greater safety of use compared to the substrates used to produce PA [3]. In addition to the high sensitivity of PA, the danger of its use was its high toxicity compared to other commonly used explosives.Item Advances in the design of explosives detonators(Sumy State University, 2021) Wojewódka, A.T.; Gerlich, M.M.The common use of explosives to break rock for excavation leads to the constant detonators development, that over past two decades significantly increased their precision in order to improve effectiveness of the blasting works. The following article presents key achievements and milestones of detonators development as well as the directions of research aimed at improving their accuracy. The construction of detonators that are currently used for civilian purposes is shown. The requirement that should be followed during the development of time delay compositions are presented, as well as the current trends in the research of gasless compositions, the burn rate of which is independent of the pressure inside the detonator.Item 2,4,6-trinitrotoluene: review of production methods and applications(Sumy State University, 2021) Gawrysiak, E.; Jarosz, T.The article presents the current state and old aspects of TNT production, along with modifications that have appeared over the years in order to improve the detonation parameters and the physical properties of the material, as well as modern improvements in the production of TNT as a crushing explosive that can be cast. The aspects of applications in the context of historical outline and their changes over the years shall also be discussed in the following paper.Item Electromagnetic Simulation of New Tunable Guide Polarizers with Diaphragms and Pins(Advanced Electromagnetics, 2021) Piltyay, S.; Булашенко, Андрій Васильович; Bulashenko, Andrii Vasylovych; Shuliak, V.; Bulashenko, O.In this article we present the results of electromagnetic simulation, development and optimization of a guide polarizer with a diaphragm and pins. An original mathematical model was obtained using the wave matrix approach for a guide polarizer with one diaphragm and two pairs of pins. The discontinuity elements were modeled as inductive or capacitive conductivities for two kinds of linear perpendicular polarizations of the electromagnetic waves. The theoretical model is based on wave scattering and transfer matrices. The total matrix of a polarizer was developed using wave matrices of transmission of separate elements of a polarizer’s structure. Using elements of the general S-parameters the electromagnetic characteristics of a considered polarizer were obtained. In order to test the performance of a suggested mathematical model, it was simulated in a software based on the finite elements method in the frequency domain. The presented design of a polarizer is adjustable due to possibility of mechanical tuning of the heights of applied pins. Considered guide polarizer with one diaphragm and two pairs of pins provides a reflection coefficient of less than 0.36 and a transmission coefficient of more than 0.93 for both linear perpendicularly polarized modes. Therefore, a new theoretical technique was developed in the research for fast electromagnetic simulation of wave matrix elements of a guide polarizers with diaphragms and pins. Developed simulation approach can also be widely used for the development of new tunable guide filters, polarizers, rotators and other microwave components with diaphragms and pins.Item Polarization conversion device based on a waveguide with pins(Sumy State University, 2021) Dmytrenko, V.Y.; Булашенко, Андрій Васильович; Bulashenko, Andrii Vasylovych; Piltyay, S.І.; Bulashenko, O.V.Today, one of the key elements of antenna systems engaged in polarization signal processing are polarization devices. These devices are used to convert the types of polarization. The following designs of polarizers in the form of waveguide structures with posts [1], irises [2, 3], ridged structures [4], polarizers with thin metal septum [5] are known. The designs of polarizing devices in the form of slots [6] are complex in design. Phase shifters [7] and filters [8] also had such constructions. In addition, polarizers are built directly into antennas [9].Item 90 degre phase shifter based on a square waveguide with diaphragms(Sumy State University, 2021) Shtykо, T.V.; Piltyay, S.І.; Булашенко, Андрій Васильович; Bulashenko, Andrii Vasylovych; Zabegalov, I.V.Modern antenna systems with polarization signal processing are used to improve the information parameters of the signals processed in them [1, 2]. The basic elements of such systems are waveguide filters [3], phase shifters [4] and polarizers [5, 6]. Phase shifters provide the required phase values at the output. Polarizers provide a differential phase shift at the output of 90º [7]. The most common structures of waveguide polarizers are structures with diaphragms [8, 9], pins [10, 11], combined with pins and diaphragms [12, 13], and coaxial structures [14, 15] and ribbed structures [16, 17]. Differential phase shifter is used in the development of phased array antennas, in the formation of the beam in modern antenna systems and for power supply systems of modern antennas [18]. Modern 90º phase shifters [19, 20] have advanced functionality, simple compact geometric shape, resistant to amplitude imbalance, the ability to maintain a stable phase with multibeam propagation. In addition, such devices are sometimes used in 5G systems [21].