4 results on '"A. I. Boiko"'
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2. Features of distribution of electric field strength and current density in the reactor during treatment of liquid media with high-voltage pulse discharges
- Author
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M. I. Boiko and A. V. Makogon
- Subjects
reactor ,electric field strength ,conductivity current density ,displacement current density ,discharge in a gas bubble in water ,inclusion in water ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
Purpose. Development and use of a mathematical model of the stages of formation of high-voltage pulse discharges in gas bubbles in the discharge gap «rod-plane» to identify the features of the electric field intensity distribution in the reactor and determine the current density in the load during disinfection and purification of liquid media by high-voltage pulse discharges and find the most rational treatment. Methodology. To achieve this goal, we used computer modeling using the finite element method as a method of numerical analysis. An experimental reactor model was created that takes into account the dynamics of discharges in gas bubbles in water. The equations describing the system include the generalized Ampere equation, the Poisson equation and the electric displacement equation, taking into account the corresponding initial and boundary conditions, as well as the properties of materials. The dependence of the potential of a high-voltage electrode on time has the form of a damped sinusoid, and the specific electrical conductivity in a gas bubble is a function of time. Processes occurring at the front of the voltage pulse from 0 to 20 ns are considered. Results. It is shown that with an increase in conductivity and high-voltage potential to amplitude values in a gas bubble, the electric field strength in the water layer in the reactor reaches 70 kV/cm, and it is in the water layer that there is a strong electric field. The calculations show that already by 19th ns the density of conduction currents in water prevails over that of displacement currents. At the same time, additional inclusions in the water significantly affect the distribution of electric field strength and current density, creating a significant difference in their values at the boundaries of the interface between the bubble, conductive element and water. Originality. A simulation of the dynamics of transient discharge processes in a gas bubble and a layer of water with impurities was carried out, including an analysis of the distribution of the electric field strength and current density in a system with rod-plane electrodes in the phase transition section of a gas bubble-water. This approach allows us to reveal the features of processes in reactors and to investigate the influence of phase transitions on the distribution of electrophysical quantities. Practical value. Computer simulations confirm the prospect of using nanosecond discharges generated in gas bubbles within a volume of water for widespread industrial use and are of great interest for further experimental and theoretical research. References 25, figures 9.
- Published
- 2024
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3. PATIENTS' CHRONOTYPE INFLUENCE IN TREATMENT EFFICIENCY OF PLACENTA CRYERXTRACT CHANGES IN MAXILLOFACIAL PHLEGMONS
- Author
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K. Lokes, M. Pérez Sayáns, V. Lychman, D. Steblovskyi, I. Boiko, and D. Avetikov
- Subjects
catalase ,chronotype ,inflammatory disease ,maxillofacial phlegmon ,superoxide dismutase ,Medicine ,Ecology ,QH540-549.5 - Abstract
Among acute odontogenic inflammatory diseases, a significant subset comprises purulent processes in soft tissues, including abscesses and phlegmons. Methods. The study encompassed 90 patients (both male and female) diagnosed with maxillofacial phlegmons, aged between 35 and 60 years. These patients were divided into three clinical groups, each comprising 30 individuals, further categorized into two subgroups based on circadian rhythms. Analyzing the obtained data, it can be asserted that the most significant changes in markers of lipid peroxidation in patients with superficial phlegmons of maxillofacial localization were experienced in both experimental groups when used against the background of treatment according to standard protocols of intravenous injections of the cryopreserved placenta without and in combination with local injection of the cryopreserved placenta as part of "Levomekol" ointment, in contrast to the control group. It was proved that the markers of lipid peroxidation underwent the most significant changes in both clinical groups compared to the control group, but the largest changes were visualized in the second clinical group. On the 5th day of treatment, SOD activity reliably increases by 15.7% in patients with the morning chronotype and 14.9% - with the evening chronotype. A significant decrease in erythrocyte catalase activity by 51.5% was noted in patients with the evening chronotype and 56.1% - with the morning chronotype. In the control group, significant changes were noted only in the late stages of treatment. The dependence of lipid peroxidation markers on the timing of surgical intervention on the patient's circadian rhythm was established, which is most clearly observed in the 2nd clinical group. Optimal healing of a purulent wound helps to reduce the duration of treatment, accelerate the rehabilitation of patients, and improve the formation of a postoperative scar. Conclusion. Thus, aligning the timing of surgical intervention for maxillofacial phlegmons with the patient's circadian rhythm, particularly when combined with intravenous injections and local application of placenta cryoextract alongside standard treatment, contributes to an optimal modulation of lipid peroxidation markers.
- Published
- 2024
- Full Text
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4. Computer simulation of operation plant effective modes for water disinfection by electrical discharges in gas bubbles
- Author
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M. I. Boiko and K. S. Tatkova
- Subjects
high-voltage water disinfection unit ,discharge unit ,sharpening spark gap ,discharge in gas bubbles in water ,discharge delay time ,long electric line ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
Purpose. Determination by means of computer simulation of the most efficient modes of operation of the installation for water disinfection using discharges in gas bubbles, in which (modes) the amplitude of voltage pulses at the processing unit and on the layer of treated water is not less than the voltage amplitude immediately after the switching discharger. Methodology. To achieve this goal, we used computer simulation using Micro-Cap 10. We used two different electrical circuits that simulate the operation of the experimental setup in two different modes: in a mode with a restoring electrical strength of the discharge gap in the gas bubble between two adjacent voltage pulses on the discharge node and in the mode without restoring this dielectric strength. In computer simulation, we varied the following factors: the maximum simulation step, inductances, capacitances, active resistances, wave resistance of a long line, and the delay time for the operation of a spark gap simulating a discharge gap in a gas bubble. Results. Computer modeling has shown that in order to increase the voltage amplitude at the treatment unit and on the layer of treated water, it is necessary to reduce the load capacitance – the capacitance of the water layer in the treatment unit to 10 pF or less, to increase the active resistance of the water layer to 500 W or more. An important factor for increasing the voltage and electric field strength in the discharge unit and, consequently, for increasing the efficiency of treated water disinfection is the discharge delay time in gas bubbles. The most rational delay time for the operation of the arrester, which is the gap in the gas bubble inside the water, under the conditions considered by us is 4–5 ns. It is with this delay time that the amplitude of voltage pulses at the node of disinfecting water treatment and on the layer of treated water is maximum, all other things being equal. Furthermore, with such a delay time this amplitude of voltage pulses significantly exceeds the voltage amplitude directly after the main high-voltage discharger, switching energy from the high-voltage capacitive storage to the processing unit through a long line filled with water. Originality. Using computer simulation, we have shown the possibility of increasing the voltage at the discharge unit of the experimental setup by 35 % without increasing the voltage of the power source. This provides a higher efficiency of microbiological disinfection of water by nanosecond discharges in gas bubbles and lower specific energy consumption. Practical value. The obtained results of computer simulation confirm the prospect of industrial application of installations using nanosecond discharges for disinfection and purification of wastewater, swimming pools and post-treatment of tap water.
- Published
- 2024
- Full Text
- View/download PDF
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