bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determining the effect of stator groove geometry in a traction synchronous reluctance motor with permanent magnets on the saw-shaped electromagnetic moment level
Authors: Liubarskyi Borys , Riabov Ievgen , Iakunin Dmytro , Dubinina Oksana , Nikonov Oleh , Domansky Vasily 
Published: July 2021

This paper reports the model of a magnetic field of the synchronous reluctance motor with permanent magnets that was developed on the basis of a finite-element method. The model was implemented in the FEMM finite-element analysis programming environment involving the application of the Lua-based script. The model makes it possible to determine the dependence of the engine's electromagnetic moment on the rotor rotation angle.
Determining the level of a saw-shaped moment is important for assessing its harmful effect on the structural elements of the traction motor and the drive in general.
The results of digital modeling have established the dependences of the electromagnetic moment on the rotor rotation angle. The moment has a variable component – the saw-shaped moment, whose amplitude for open grooves under a rated load mode is 182 Nm, and for semi-open grooves ‒ 90 Nm.
The use of semi-open grooves exerts a positive effect on eliminating the saw-shaped moment in a synchronous reluctance motor with permanent magnets and may be recommended for further application on engines of this type. Semi-open grooves reduce the opening of the stator groove by 2 times and lead to a smoother flux distribution under the gear division. That reduces the oscillations of the main magnetic flux. The proposed application of semi-open stator grooves makes it possible to reduce by more than 2 times the level of a saw-shaped moment of the synchronous reluctance motor with permanent magnets under a rated mode.
It has been determined that a rather positive factor is an increase of 4.8 % in the average motor moment value under a rated mode when using semi-open grooves. This is due to a decrease in the average value of magnetic resistance to the main magnetic flux. Therefore, with a simultaneous decrease in the moment's fluctuations, the transition to semi-open grooves makes it possible to improve the mass-dimensional indicators of the motor in general.
Development of the survivability indicators forecasting method of the special-purpose system executive element based on analytical and stochastic simulation of a conflict situation
Authors: Hohoniants Spartak , Chopa Dmytro , Kilmeninov Oleksii , Loishyn Anatolii , Нorbachov Kostyantin 
Published: July 2021

The developed method for forecasting the survivability indicators of the executive element of a special-purpose system based on analytical-stochastic simulation of a conflict situation is presented. The purpose of the method was to solve the problem of preserving and rational use of the resource of the executive elements to achieve the desired effect of the functioning of special-purpose systems.
The method is sensitive to the description of the patterns of changes in the survivability and efficiency indicators of the system. It is supposed to compare the predicted value of the survivability indicator with its criterion value and forecast the time when the system loses the ability to effectively perform tasks.
The survivability indicator is the mathematical expectation of the number of executive elements of a special-purpose system, which retained their ability to perform tasks as intended during a conflict situation.
Based on the results of the study, the values of the time characteristics of a conflict situation were obtained, in particular, the duration of the corresponding states of the executive element: preparation, waiting, implementation.
Graph-analytical simulation provides a solution to the problem of forecasting the time when the loss of executive elements leads to the system’s inability to effectively perform tasks.
Checking of the adequacy of the method showed that the confidence interval of the discrepancy between the calculation results of other methods with a confidence level of 0.9 does not exceed 0.095, and no contradictions between the methods were found. The proposed method provides an increase in the efficiency of determining the corresponding indicators within 8–11 % and reliability by 22 %. The possibility to determine the required reserve and the time for introducing executive elements into the system can provide a justification for how they are used to maintain the required level of efficiency of a special-purpose system.
Integrating linear ordinary fourth-order differential equations in the MAPLE programming environment
Authors: Belyaeva Irina , Kirichenko Igor , Ptashnyi Oleh , Chekanova Natalia , Yarkho Tetiana 
Published: July 2021

This paper reports a method to solve ordinary fourth-order differential equations in the form of ordinary power series and, for the case of regular special points, in the form of generalized power series. An algorithm has been constructed and a program has been developed in the MAPLE environment (Waterloo, Ontario, Canada) in order to solve the fourth-order differential equations. All types of solutions depending on the roots of the governing equation have been considered. The examples of solutions to the fourth-order differential equations are given; they have been compared with the results available in the literature that demonstrate excellent agreement with the calculations reported here, which confirms the effectiveness of the developed programs. A special feature of this work is that the accuracy of the results is controlled by the number of terms in the power series and the number of symbols (up to 20) in decimal mantissa in numerical calculations. Therefore, almost any accuracy allowed for a given electronic computing machine or computer is achievable. The proposed symbolic-numerical method and the work program could be successfully used for solving eigenvalue problems, in which controlled accuracy is very important as the eigenfunctions are extremely (exponentially) sensitive to the accuracy of eigenvalues found. The developed algorithm could be implemented in other known computer algebra packages such as REDUCE (Santa Monica, CA), MATHEMATICA (USA), MAXIMA (USA), and others. The program for solving ordinary fourth-order differential equations could be used to construct Green’s functions of boundary problems, to solve differential equations with private derivatives, a system of Hamilton’s differential equations, and other problems related to mathematical physics.
Comparative analysis of the exergy efficiency of methods for protecting gas exhaust ducts of boiler plants
Authors: Fialko Nataliia , Stepanova Alla , Navrodska Raisa , Shevchuk Svitlana 
Published: July 2021

This paper reports the results of studying the exergy effectiveness of thermal methods for anti-corrosion protection of the gas-draining tracts of boiler plants. These include the method of mixing heated air into flue gases, the method of passing part of the hot gases of the boiler through the bypass chimney, and a flue gas drying method. The research involved the devised comprehensive procedure based on an exergy approach. The dependences of exergy loss Elos and the heat- exergy criterion ε on the following parameters of thermal methods have been established: the amount of heated air N mixed into flue gases, the proportion of bypassed flue gases K, and the amount of dried flue gases R. A comparative analysis of the effectiveness of heat recovery systems when applying the methods considered has been performed. It has been established that for the method of mixing, Elos and ε at ambient temperature ten=10 °C demonstrate the lowest values, that is, the efficiency of the system, in this case, is the highest. The most effective, when implementing the bypass method, is the heat recovery system at ten=10 °C. Under the method of drying, at all values of the amount of dried flue gases, the loss of exergy is the lowest at ten=0 °C. As regards the heat- exergy criterion, at values R≤20 %, the lowest values of ε are observed at ten=10 °C. At R>20 %, the lowest values of ε are at ten=0 °C. Thus, the efficiency of the system when implementing the method of drying is the highest at ten=0 °C and at the amount of dried air of R>20 %. The study reported here would provide the necessary information for designing optimal heat recovery schemes. The development of this study is to establish the relationship between the exergy and environmental efficiency of thermal protection methods in order to further reduce toxic emissions.
Development of an algorithm for selecting the required frequency of injected current for multi-frequency electrical impedance tomography for tasksrelated to preoperative monitoring of human lung function
Authors: Grayr Aleksanyan 
Published: July 2021

This paper proposes an algorithm for selecting the required frequency of injected current for problems of personalized multi-frequency electricalimpedance tomography. The essence of the algorithm is to calculate the rate of change in the recorded difference of potentials for the assigned range of frequencies of injected current, followed by determining the frequency after which the rate of a change in potentials is minimal. Subsequently, the injection parameters are readjusted to the chosen frequency and the complete process of electricalimpedance tomography is started. The proposed solutions were studied on four subjects with different fat mass, defined by bioimpedance analysis. Thus, it seems possible to track the dynamics of a change in the lungs of a certain patient by visualizing the reconstructed conductivity field, taking into consideration its internal features. It was established that in the course of studying lungsby using the method of electricalimpedance tomography, it is necessary to take into account the frequency of injected current at an increase in percentage of fat mass. The results of the studies showing a change in the quality of imaging the breathing process at different frequencies of injected current (from 50 kHz to 400 kHz, with a pitch of 50 kHz) are presented. For the test participants with a fat weight of 7.6 kg, 23.3 kg, 15.2 kg and 37.3 kg, the injection frequency was determined as 150 kHz, 200 kHz, 200 kHz, and 350 kHz, respectively.
The proposed algorithm enables visual monitoring of lung function and can be used in the problems of pre- and postoperative monitoring of respiratory function of patients. Its use is particularly relevant for patients connected to an apparatus of artificial lung ventilation.
Development of a technology of gas-flame application of powders to increase wear resistance and adhesion strength
Authors: Yermekov Daulet , Povetkin Vitaly , Rutkuniene Zivile , Nurmukhanova Alfiya , Bukayeva Amina 
Published: July 2021

Every year, the world economy suffers enormous losses due to wear and corrosion of machine parts and equipment. With targeted preventive protection against wear and tear, these losses can be avoided. Along with the coating of new parts, this includes the restoration of worn parts. An effective method is the surfacing of materials with high performance properties. The quality of hardened parts depends on the properties of deposited material, so hardening material or alloy is selected taking into account the working environment of the part and the coating method.
Today there are many self-fluxing surfacing powder alloys based on nickel, copper and others, obtained by different methods.
The paper discusses the process of studying the gas-flame application of powders to increase wear resistance and adhesion strength. Experimental studies have been carried out to determine the optimal composition of the CrB2 master alloy introduced into the composition of the GP-Ir40 surfacing alloy. It has been found that to obtain the hardness of the deposited metal in the range of 450–600 HV, it is necessary to introduce CrB2 into the coating composition, within 10 % of the total mass. Thus, the strength of the alloy is increased by more than 54.41 HV. Tests for corrosion resistance in aggressive environments of hydrogen sulfide H2S, sulfuric acid H2SO4 were carried out. The wear resistance of ground pumps was evaluated, and the service life of wear-resistant ground pump parts made of the IChH28N2 alloy was determined.
The new developed self-fluxing surfacing powder material based on iron with a hardening additive will be used to restore machine and equipment parts operating under conditions of abrasive wear, corrosion and elevated temperatures or corrosive environments
Overview of concepts of the sphingolipid metabolism
Authors: Storozhenko Galyna , Kharchenko Vitalina , Krasilnikova Oksana , Tkachenko Oksana 
Published: July 2021

Sphingolipids are important components of the cell involved in the processes of apoptosis, inflammation, oncogenesis, aging, proliferation, differentiation and growth of cells, as well as in the stress-induced response of cells.
The aim. To study research literature for summarizing the new concepts of sphingolipids biochemical role in the development of various pathological conditions.
Materials and methods. The open sources of scientific literature were analyzed.
Results and discussion. According to the analyzed data, the occurrence of pathologies is associated with the sphingolipid imbalance in cells, and excessive accumulation of ceramides, while by preventing the accumulation of ceramides in cells, it is possible to prevent the appearance of cardiac, neurological and metabolic pathologies, including insulin resistance, heart disease (atherosclerosis, heart failure), as well as hepatic steatosis. Therefore, it is promising to search for drugs that can inhibit individual components of the metabolism of sphingolipids and prevent the development of pathology.
Conclusions. Sphingolipids are involved in numerous processes in cells, and changes in the balance of individual members of this class of lipids can play a crucial role in the development of pathological conditions. At the same time, the accumulated data on disorders of the sphingolipid metabolism in various diseases contribute to the development of drugs based on inhibition of the corresponding components of the metabolism of these lipids.
The study of the anti-inflammatory properties of carotenoid liquid extracts on the model of adjuvant-induced inflammation
Authors: Boiko Yurii , Ayat Mohammed , Boiko Irina , Shandra Alexey 
Published: July 2021

The search for new anti-inflammatory substances is an important area of pharmacology. Plant carotenoids have many positive biological effects and are of interest as potential anti-inflammatory agents.
The aim. To study the anti-inflammatory properties of extractive carotenoids from fruits of Capsicum annuum L. on the model of adjuvant-induced inflammation.
Materials and methods. The fruits of Capsicum annuum L. were used as the plant raw material. Carotenoids were obtained by the extractive method. The model of adjuvant-induced inflammation was reproduced in young female rats. The dynamics of changes in the volume of the inflammatory edema and the total number of blood leukocytes were studied.
Results and discussion. A decrease in edema in nonspecific inflammation was observed on day 15 during the therapy with carotenoid extracts (Δ1.01±0.08 in treatment group; Δ1.28±0.08 in control group). For specific inflammation, edema reduction when using carotenoids occurred on day 30 (Δ0.047±0.015 in treatment group; Δ0.073±0.012 in control group). A decrease in leukocytosis occurred on days 20 and 30 of the treatment for non-specific and specific inflammation, respectively. The mechanisms of the anti-inflammatory action of carotenoids are presumably associated with the antioxidant effect and the ability to affect the production of pro-inflammatory cytokines.
Conclusions. Extractive carotenoids from the fruits of Capsicum annuum L. have the anti-inflammatory activity in the case of adjuvant-induced inflammation. Treatment with Capsicum annuum L. extract reduced inflammatory edema and total leukocyte count
Prevention of subinvolution of the uterus of cows using acidum succinicum
Authors: Fedonyuk Larysa , Stravskyy Yaroslav , Khavtur Vira , Sachuk Roman 
Published: July 2021

Aim. To establish the effect of acidum succinicum on the activity of enzymes in the blood of cows after calving and the course of uterine involution.
Materials and Methods. The study of enzyme activity was carried out in the Central Research Laboratory of I. Horbachevsky Ternopil National Medical University (Certificate of technical competence № 001/18, issued on September 26, 2018, valid until September 25, 2023).
Results of the research. After the use of acidum succinicum in the body of cows of the experimental group, the activity of alanine aminotransferase increased by 12,0 % (p≤0,05), and the activity of aspartate aminotransferase, on the contrary, decreased by 30,0 % (p≤0,001), which indicates a positive effect on hepatocytes. Confirmation of this is the Ritis factor, which increased 1,4 times (p≤0,05).
All animal experiments were conducted according to with the recommendations of ARRIVE and the British Animal Act 1986 and Directive 2010/63 / EU on the protection of animals for scientific investigation.
In the body of cows of the control group, the activity of alanine and aspartateaminotransferases increased, respectively, by 14,0 % (p≤0,05) and 47,0 % (p≤0,001) against a background of a 1,2-fold decrease (p≤0,05) Ritis factor.
A decrease in bilirubin content of 56,0 % (p≤0,001) in the body of cows after the use of acidum succinicum and an increase in its content by 2,2 times (p≤0,001) in the body of control cows indicates liver disease, which is accompanied by affection of its parenchyma, which may be a consequence of intoxication of their body in the last trimester of pregnancy.
Conclusion. Acidum succinicum, applied to cows after calving, prevents the development of inflammation of the reproductive system, helps to restore reproductive function, reduces the duration of the service period to 80,0±2,0 days, and the insemination index to 1,3
Research into the process of carbonate conversion of phosphogypsum in the water media
Authors: Yelatontsev Dmytro 
Published: July 2021

For a long time, the problem of phosphogypsum disposal was not given due attention, which led to the accumulation of huge reserves of this environmentally hazardous waste. Transportation of phosphogypsum in dumps and its storage requires significant capital investment and operating costs, as well as the allocation of large land areas. The storage of phosphogypsum harms the environment, as it leads to the entry of significant amounts of toxic substances into groundwater and the atmosphere. The object of the study was phosphogypsum, which is formed during the production of phosphoric acid from apatites and phosphorites. To date, numerous studies have focused on finding effective ways to use phosphogypsum, but its composition usually limits its reuse. The research aims to study the scientific prerequisites for creating an effective control scheme for phosphogypsum by converting it to calcium carbonate. For this purpose, the chemical composition and technological parameters of phosphogypsum conversion from the dumps of «Dnipro Mineral Fertilizer Plant» (Kamianske, Ukraine) were studied. The proposed conversion method involved a reaction between phosphogypsum and aqueous NaOH solution to form Ca(OH)2, which was converted to CaCO3 by carbonization in a CO2 stream. The influence of temperature on the conversion of phosphogypsum into Ca(OH)2 has been established. The conversion was investigated at 25 °C, 40 °C, and 70 °C for 3 hours. It was found that at the first stage of the process the impurities contained in phosphogypsum were transferred to the precipitate of Ca(OH)2. As a result of carbonization, low-quality CaCO3 was obtained, which contained more than 10% of impurities. Increasing the duration of carbonization to 1 hour allowed to obtain CaCO3 with content of Ca(OH)2<4 %. The results of the study show that the method of carbonate conversion of phosphogypsum requires further optimization of technological parameters to improve the purity of the finished product.
Optimization of parameters of the extraction process of biologically active substances of grass Adonis vernalis
Authors: Krvavych Anna , Konechna Roksolana 
Published: July 2021

The object of this research is the herb Adonis vernalis and hydroalcoholic extracts obtained on its basis. By the nature of the action, the drugs Adonis vernalis belong to the group of cardiac glycosides and occupy an intermediate place between strophanthin and digitalis. In official medicine, biologically active compounds of Adonis vernalis are included in drugs such as Cardiovalen, Adonis-bromine, Caridiolin and Cardiophyte. In the extemporal formulation, the extract is part of the Bechterew’s medicine. Until recently, scientists have made significant progress in studying the phytochemical and pharmacological action of the herb Adonis vernalis. However, one should not be limited to the use of Adonis vernalis only for stimulating cardiac activity, one should also consider the promising antioxidant effect of flavonoids and phenolic compounds that are contained in this medicinal plant. Also, studies of the extraction conditions of the herb Adonis vernalis are not described in the scientific literature.
The study carried out the extraction of the grass Adonis vernalis by various methods (static and dynamic). The type of extract was chosen as the most rational, which provides the maximum yield of extractives (phenolic compounds and cardiac glycosides). For this, the optimal extraction conditions were selected, namely, the particle size, the type of extractant, the value of the hydromodule and the extraction method. Accordingly, the optimal particle diameter for maximum extraction of biologically active substances of the herb Adonis vernalis is 2.5 mm, the optimal extractant is 70 % ethyl alcohol, the ratio of raw materials: extractant is 1:10, the optimal extraction method is maceration with constant stirring. Phytochemical studies of the quantitative composition of the main groups of biologically active substances were carried out using calorimetric and spectrophotometric methods of analysis.
As a result of the optimization of the process and its introduction into production on an industrial scale, the value added effect will be achieved. And also a high-quality product has been created that will compete with broad-spectrum drugs already existing on the market.