Pub Date : 2023-10-11DOI: 10.21122/2227-1031-2023-22-5-418-427
V. A. Sednin, R. S. Ignatovich, I. L. Iokova
As part of ensuring the country's energy security and pursuing a policy of decarbonization of the economy in the Republic of Belarus, the maximum use of its own fuel and energy resources (FER) is expected. However, the question of choosing the type of heat source in centralized heat supply systems when using local fuels (LF) remains open. The commissioning of the Belarusian Nuclear Power Plant and the relatively high specific cost of electricity generating capacities using local fuels tip the scales to the use of boiler houses as heat sources. However, world experience in the development and application of heating, as the most energy-efficient solution in the field of heat supply, requires a more thorough study of this problem. The paper presents an overview of the use of local fuels in Belarus and a number of European countries with developed centralized heat supply. Based on the analysis of open source data, the paper provides information on the state of use of local fuels in district heating systems of the Republic of Belarus and a number of European countries that have experience in the widespread use of solid biomass and where it constitutes a significant share in the structure of thermal and electrical energy production in relation to other fuel and energy resources. The main aspects of the energy programs of a number of European countries with the largest share of thermal and electrical energy generation using local fuels are presented. It has been revealed that the energy program of Finland is of the greatest interest for Belarus, where the share of nuclear energy in the structure of electrical energy production, just like in the Republic of Belarus, is approaching to 40 % and the energy strategy assumes an increase in the share of thermal power plants using local fuels in the structure of heat and electricity generation.
{"title":"On the Feasibility of Building Mini-Thermal Power Plant Using Local Fuels in the Conditions of the Republic of Belarus. Part 1. State of Use of Local Fuels in Heat Supply Systems","authors":"V. A. Sednin, R. S. Ignatovich, I. L. Iokova","doi":"10.21122/2227-1031-2023-22-5-418-427","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-5-418-427","url":null,"abstract":"As part of ensuring the country's energy security and pursuing a policy of decarbonization of the economy in the Republic of Belarus, the maximum use of its own fuel and energy resources (FER) is expected. However, the question of choosing the type of heat source in centralized heat supply systems when using local fuels (LF) remains open. The commissioning of the Belarusian Nuclear Power Plant and the relatively high specific cost of electricity generating capacities using local fuels tip the scales to the use of boiler houses as heat sources. However, world experience in the development and application of heating, as the most energy-efficient solution in the field of heat supply, requires a more thorough study of this problem. The paper presents an overview of the use of local fuels in Belarus and a number of European countries with developed centralized heat supply. Based on the analysis of open source data, the paper provides information on the state of use of local fuels in district heating systems of the Republic of Belarus and a number of European countries that have experience in the widespread use of solid biomass and where it constitutes a significant share in the structure of thermal and electrical energy production in relation to other fuel and energy resources. The main aspects of the energy programs of a number of European countries with the largest share of thermal and electrical energy generation using local fuels are presented. It has been revealed that the energy program of Finland is of the greatest interest for Belarus, where the share of nuclear energy in the structure of electrical energy production, just like in the Republic of Belarus, is approaching to 40 % and the energy strategy assumes an increase in the share of thermal power plants using local fuels in the structure of heat and electricity generation.","PeriodicalId":160642,"journal":{"name":"Nauka i Tehnika","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136063049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-11DOI: 10.21122/2227-1031-2023-22-5-428-432
N. O. Ataullaev, A. A. Dziaruhina, K. S. Murodov
The paper examines the most important requirements for current converters, the features of magnetic modulation converters, and identifies their fundamental and design features. The paper considers the principle of constructing converters for contactless DC measurement and their disadvantages of converters, methods of current measurement using magnetic modulation current converters, in which the magnetic permeability of a core made of ferromagnetic material is modulated. The influence of the parameters of the elements of a magnetic modulation current converter with an analog filter on their static characteristics and the influence of modulation on the static characteristics of the sensor have been determined. It has been revealed that the discrete operation of the magneto-modulation DC converter does not affect its static characteristics and the nonlinearity due to the type of modulation also does not affect the static characteristics of the sensor. The most important requirement for the operation of a magneto-modulation DC converter for autonomous power supplies with recharging buffer batteries is the formation of a static characteristic with the specified properties: linearity, sensitivity and the required range of operating currents. An analytical expression for the static characteristic is obtained in the form of the dependence of the output voltage on the values of T 1 and T 2 for the basic version of a magnetic modulation DC converter with an analog low-pass filter. Curves of the static characteristics of the magneto-modulation DC converter have been constructed for different values of the resistance of the ballast resistor R, as well as curves of the static characteristics of the magneto-modulation DC converter for different values of the supply voltage E. Analytical expressions for the static characteristics of a magneto-modulation DC converter based on magnetic transistor multivibrators with pulse-width modulation, curves of their characteristics and the output voltage of a magnetic modulation DC converter with a digital output and a discrete filter have been obtained.
{"title":"Static Characteristics of Magnetic Modulation DC Converters with Analog Filter","authors":"N. O. Ataullaev, A. A. Dziaruhina, K. S. Murodov","doi":"10.21122/2227-1031-2023-22-5-428-432","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-5-428-432","url":null,"abstract":"The paper examines the most important requirements for current converters, the features of magnetic modulation converters, and identifies their fundamental and design features. The paper considers the principle of constructing converters for contactless DC measurement and their disadvantages of converters, methods of current measurement using magnetic modulation current converters, in which the magnetic permeability of a core made of ferromagnetic material is modulated. The influence of the parameters of the elements of a magnetic modulation current converter with an analog filter on their static characteristics and the influence of modulation on the static characteristics of the sensor have been determined. It has been revealed that the discrete operation of the magneto-modulation DC converter does not affect its static characteristics and the nonlinearity due to the type of modulation also does not affect the static characteristics of the sensor. The most important requirement for the operation of a magneto-modulation DC converter for autonomous power supplies with recharging buffer batteries is the formation of a static characteristic with the specified properties: linearity, sensitivity and the required range of operating currents. An analytical expression for the static characteristic is obtained in the form of the dependence of the output voltage on the values of T 1 and T 2 for the basic version of a magnetic modulation DC converter with an analog low-pass filter. Curves of the static characteristics of the magneto-modulation DC converter have been constructed for different values of the resistance of the ballast resistor R, as well as curves of the static characteristics of the magneto-modulation DC converter for different values of the supply voltage E. Analytical expressions for the static characteristics of a magneto-modulation DC converter based on magnetic transistor multivibrators with pulse-width modulation, curves of their characteristics and the output voltage of a magnetic modulation DC converter with a digital output and a discrete filter have been obtained.","PeriodicalId":160642,"journal":{"name":"Nauka i Tehnika","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136210644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-11DOI: 10.21122/2227-1031-2023-22-5-433-440
D. N. Mesnik, D. F. Vecherko
In the Republic of Belarus in 2021, the volume of electricity consumption at car charging stations increased by about 38 % compared to 2020 and amounted to about 10 million kW∙h. Belarusian experts noted that the operation of an electric car is about 2 times more profitable for its owner than a car with an internal combustion engine. In general, for the economy, under the condition of equality of environmental pollution at the stages of extraction of natural resources and the disposal of electronic waste, the electric car retains a win. Renewal of the fossil fuel vehicle fleet with vehicles powered by renewable energy sources is a task that requires the implementation of a mechanism for adapting the transport and logistics system to modern challenges of the global economy. To date, the number of electric vehicles and rechargeable hybrids in Belarus is slightly more than 10 thousand units. An increase in the public electric transport fleet was noted – over 100 elect-ric buses. In turn, the development of the IT sector and the need to switch to the production of vehicles for environmentally friendly types of the Euro-7 standard, the introduction of which is expected from 2025, prompted global car manufacturers to produce electric vehicles and rechargeable hybrids, which are superior in environmental parameters to fossil-based counterparts fuel and correspond to the time of growth of the disposable income of the mass consumer. In order to avoid the loss of economic benefits with the renewal of the car fleet with electric vehicles, the paper examines the mechanism for adapting the infrastructure of the motor transport service to the modern challenges of the global economy.
{"title":"Mechanism for Development of Transport and Logistics System: Electric Transport Infrastructure","authors":"D. N. Mesnik, D. F. Vecherko","doi":"10.21122/2227-1031-2023-22-5-433-440","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-5-433-440","url":null,"abstract":"In the Republic of Belarus in 2021, the volume of electricity consumption at car charging stations increased by about 38 % compared to 2020 and amounted to about 10 million kW∙h. Belarusian experts noted that the operation of an electric car is about 2 times more profitable for its owner than a car with an internal combustion engine. In general, for the economy, under the condition of equality of environmental pollution at the stages of extraction of natural resources and the disposal of electronic waste, the electric car retains a win. Renewal of the fossil fuel vehicle fleet with vehicles powered by renewable energy sources is a task that requires the implementation of a mechanism for adapting the transport and logistics system to modern challenges of the global economy. To date, the number of electric vehicles and rechargeable hybrids in Belarus is slightly more than 10 thousand units. An increase in the public electric transport fleet was noted – over 100 elect-ric buses. In turn, the development of the IT sector and the need to switch to the production of vehicles for environmentally friendly types of the Euro-7 standard, the introduction of which is expected from 2025, prompted global car manufacturers to produce electric vehicles and rechargeable hybrids, which are superior in environmental parameters to fossil-based counterparts fuel and correspond to the time of growth of the disposable income of the mass consumer. In order to avoid the loss of economic benefits with the renewal of the car fleet with electric vehicles, the paper examines the mechanism for adapting the infrastructure of the motor transport service to the modern challenges of the global economy.","PeriodicalId":160642,"journal":{"name":"Nauka i Tehnika","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136209476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-10DOI: 10.21122/2227-1031-2023-22-5-359-366
D. V. Sapsaliou, A. S. Petrovskaya, D. L. Radyukevich, T. N. Tolstaya, G. B. Melnikova, S. A. Chizhik
The nanocomposite polymer – inorganic materials formation, the study of their morphology and mechanical properties at the nanolevel is acute in the development of new materials for various functional purposes, including medical ones. As a result of the research the technique for producing singleand multilayer films of polyvinyl alcohol and composite polymer coatings with aluminum oxide nanoparticles by the spin coating method has been developed. It is shown that the optimal mass content of aluminum oxide nanoparticles in suspension for the formation of uniform composite coatings is 0.625 %. Based on experimental data on the structuralmorphological and mechanical properties of the formed coatings obtained by atomic force microscopy, it has been found that an increase in the number of layers of composite coatings leads to an increase in the number of conglomerates which, in turn, increases the surface roughness of the films. The modulus of elasticity of single-layer films of polyvinyl alcohol is (509.5 ± 10 %) MPa. In the case of composite coatings with aluminum oxide nanoparticles, changes in the elastic modulus have been established for multilayer coatings: an increase to 559.0 MPa (5 layers) and a decrease to 415.2 MPa (10 layers). The modulus of elasticity of the investigated single-layer coatings is significantly reduced in the range of 20−40 ºС. The smallest values after exposure to temperatures have been determined for films with nanoparticles (236.2 ± 10 %) MPa. Nanocomposites demonstrate an increase in the contact angle with an increase in the number of layers of composite coatings up to 20. A subsequent increase in the thickness of the coatings (the number of layers) leads to an increase in the hydrophilicity of the nanocomposites. The developed compositions of nanocomposite films are promising as sorption coatings.
{"title":"Structure and Properties of Multilayer Nanocomposite Coatings of Polyvinyl Alcohol with Aluminum Oxide Nanoparticles","authors":"D. V. Sapsaliou, A. S. Petrovskaya, D. L. Radyukevich, T. N. Tolstaya, G. B. Melnikova, S. A. Chizhik","doi":"10.21122/2227-1031-2023-22-5-359-366","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-5-359-366","url":null,"abstract":"The nanocomposite polymer – inorganic materials formation, the study of their morphology and mechanical properties at the nanolevel is acute in the development of new materials for various functional purposes, including medical ones. As a result of the research the technique for producing singleand multilayer films of polyvinyl alcohol and composite polymer coatings with aluminum oxide nanoparticles by the spin coating method has been developed. It is shown that the optimal mass content of aluminum oxide nanoparticles in suspension for the formation of uniform composite coatings is 0.625 %. Based on experimental data on the structuralmorphological and mechanical properties of the formed coatings obtained by atomic force microscopy, it has been found that an increase in the number of layers of composite coatings leads to an increase in the number of conglomerates which, in turn, increases the surface roughness of the films. The modulus of elasticity of single-layer films of polyvinyl alcohol is (509.5 ± 10 %) MPa. In the case of composite coatings with aluminum oxide nanoparticles, changes in the elastic modulus have been established for multilayer coatings: an increase to 559.0 MPa (5 layers) and a decrease to 415.2 MPa (10 layers). The modulus of elasticity of the investigated single-layer coatings is significantly reduced in the range of 20−40 ºС. The smallest values after exposure to temperatures have been determined for films with nanoparticles (236.2 ± 10 %) MPa. Nanocomposites demonstrate an increase in the contact angle with an increase in the number of layers of composite coatings up to 20. A subsequent increase in the thickness of the coatings (the number of layers) leads to an increase in the hydrophilicity of the nanocomposites. The developed compositions of nanocomposite films are promising as sorption coatings.","PeriodicalId":160642,"journal":{"name":"Nauka i Tehnika","volume":"256 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136357471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-10DOI: 10.21122/2227-1031-2023-22-5-397-404
S. N. Leonovich, E. A. Sadovskaya, A. A. Koleda
Nanomodified fiber-reinforced concrete is a building material for which the required characteristics of fracture toughness are a distinctive feature. Determination of the stress intensity factor of fiber-reinforced concrete makes it possible to correctly assess the resistance of the material during the formation and development of cracks. The proposed multi-parameter methodology for assessing the quality indicators of nanomodified fiber-reinforced concrete makes it possible to evaluate the quality of a fiber-reinforced concrete structure in construction and laboratory conditions. To carry out control at the construction site, modern and long-used methods of non-destructive testing are used: ultrasonic sounding, ultrasonic tomography, elastic rebound, separation with chipping. For laboratory studies, the technique provides for the manufacture of prism samples that can be molded or cut from the body of the structure. This methodology makes it possible to obtain in laboratory conditions such material parameters as tensile strength in bending, tensile strength in splitting, critical stress intensity factor for normal separation, critical stress intensity factor for transverse shear, energy consumption for individual stages of deformation and destruction of the sample, as well as to evaluate the uniformity of distribution fibers. Moreover, it is provided to obtain all the parameters on one sample from the series, which eliminates errors and inaccuracies in the quality indicators of the material associated with different conditions of hardening, molding, inaccuracies in duplicating the composition.
{"title":"Multi-Parameter Methodology for Assessing Quality Indicators of Nanomodified Fiber-Reinforced Concrete for Construction Site","authors":"S. N. Leonovich, E. A. Sadovskaya, A. A. Koleda","doi":"10.21122/2227-1031-2023-22-5-397-404","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-5-397-404","url":null,"abstract":"Nanomodified fiber-reinforced concrete is a building material for which the required characteristics of fracture toughness are a distinctive feature. Determination of the stress intensity factor of fiber-reinforced concrete makes it possible to correctly assess the resistance of the material during the formation and development of cracks. The proposed multi-parameter methodology for assessing the quality indicators of nanomodified fiber-reinforced concrete makes it possible to evaluate the quality of a fiber-reinforced concrete structure in construction and laboratory conditions. To carry out control at the construction site, modern and long-used methods of non-destructive testing are used: ultrasonic sounding, ultrasonic tomography, elastic rebound, separation with chipping. For laboratory studies, the technique provides for the manufacture of prism samples that can be molded or cut from the body of the structure. This methodology makes it possible to obtain in laboratory conditions such material parameters as tensile strength in bending, tensile strength in splitting, critical stress intensity factor for normal separation, critical stress intensity factor for transverse shear, energy consumption for individual stages of deformation and destruction of the sample, as well as to evaluate the uniformity of distribution fibers. Moreover, it is provided to obtain all the parameters on one sample from the series, which eliminates errors and inaccuracies in the quality indicators of the material associated with different conditions of hardening, molding, inaccuracies in duplicating the composition.","PeriodicalId":160642,"journal":{"name":"Nauka i Tehnika","volume":"256 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136357863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-10DOI: 10.21122/2227-1031-2023-22-5-405-410
A. K. Esman, G. L. Zykov, V. A. Potachits, V. K. Kuleshov
Solar power is one of the largest sectors of the global electric and heat power industry. In search of new energy sources, scientists and engineers around the world are increasingly turning their attention to solar batteries, which can be a suitable replacement for non-renewable energy sources. Vertically oriented solar batteries will generate electricity throughout the daylight hours, which eliminates use of additional equipment. The paper proposes a 3D model of a solar battery with a vertical orientation of its modules, as well as the calculation and evaluation of temperature characteristics and the range of efficiency variations obtained under conditions of both the diurnal and seasonal changes in ambient temperature, and the power density changes of concentrated solar radiation, the maximum values of which were chosen equal to 1; 5 and 10 kW/m 2 . The dependences of the maximum values of the solar battery temperature and the temperature gradient inside it, as well as the dependences of the minimum, average and maximum values of the radiative heat flux to the solar battery surface in the presence and absence of temperature stabilization of the heat sink backside versus the time of day in the middle of January and July have been plotted. As calculations have shown, at the solar radiation concentration of 10 kW/m 2 , the efficiency in July is increased by more than 2 times due to the use of thermoelectric converters in the battery. Moreover, according to the obtained results, when the solar modules are oriented vertically, temperature gradients and, consequently, the total efficiency of the solar battery and power generation time will be greater compared to the horizontal position of the solar modules, which will reduce operational costs.
{"title":"Study of Vertically Oriented Solar Battery by Exposure of Concentrated Solar Radiation","authors":"A. K. Esman, G. L. Zykov, V. A. Potachits, V. K. Kuleshov","doi":"10.21122/2227-1031-2023-22-5-405-410","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-5-405-410","url":null,"abstract":"Solar power is one of the largest sectors of the global electric and heat power industry. In search of new energy sources, scientists and engineers around the world are increasingly turning their attention to solar batteries, which can be a suitable replacement for non-renewable energy sources. Vertically oriented solar batteries will generate electricity throughout the daylight hours, which eliminates use of additional equipment. The paper proposes a 3D model of a solar battery with a vertical orientation of its modules, as well as the calculation and evaluation of temperature characteristics and the range of efficiency variations obtained under conditions of both the diurnal and seasonal changes in ambient temperature, and the power density changes of concentrated solar radiation, the maximum values of which were chosen equal to 1; 5 and 10 kW/m 2 . The dependences of the maximum values of the solar battery temperature and the temperature gradient inside it, as well as the dependences of the minimum, average and maximum values of the radiative heat flux to the solar battery surface in the presence and absence of temperature stabilization of the heat sink backside versus the time of day in the middle of January and July have been plotted. As calculations have shown, at the solar radiation concentration of 10 kW/m 2 , the efficiency in July is increased by more than 2 times due to the use of thermoelectric converters in the battery. Moreover, according to the obtained results, when the solar modules are oriented vertically, temperature gradients and, consequently, the total efficiency of the solar battery and power generation time will be greater compared to the horizontal position of the solar modules, which will reduce operational costs.","PeriodicalId":160642,"journal":{"name":"Nauka i Tehnika","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136357071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-10DOI: 10.21122/2227-1031-2023-22-5-376-386
D. A. Stepanenko, I. Mudinov, V. A. Akhremchyk, V. A. Akhremchyk
Тhe paper describes a technique of topological optimization of osteosynthesis plates used for internal fixation of bone fractures. The proposed technique is based on the application of the density method and the commercially available COMSOL Multiphysics software intended for finite element modeling. A comparative analysis of the characteristics (axial stiffness, volume and maximum von Mises stress) is presented for initial design of the plate and two optimized variants of the design. It has been established that the optimized variants provide a reduction in the plate volume by 49–54 %. In this case, the axial stiffness decreases by 43–53 %, which is a positive effect in terms of minimizing the effect of stress shielding. The optimized variants of the design possess close values of axial stiffness and maximum von Mises stress, however, in one of them, deflection of the axial segments occurs, resulting in an increase in the total strain energy, which is used as an objective function during optimization. In the variant 2 of the design, the deflection of the longitudinal segments of the plate is eliminated due to the presence of a transverse bridge between them, and the total strain energy takes on a lower value. The variant of the design without a bridge should be additionally studied, since shear stresses resulting from the contact interaction of the longitudinal segments of the plate with the bone can have a positive effect on regeneration of the bone tissue.
{"title":"On Possibility of Application of COMSOL Multiphysics Software for Topological Optimization of Osteosynthesis Plates","authors":"D. A. Stepanenko, I. Mudinov, V. A. Akhremchyk, V. A. Akhremchyk","doi":"10.21122/2227-1031-2023-22-5-376-386","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-5-376-386","url":null,"abstract":"Тhe paper describes a technique of topological optimization of osteosynthesis plates used for internal fixation of bone fractures. The proposed technique is based on the application of the density method and the commercially available COMSOL Multiphysics software intended for finite element modeling. A comparative analysis of the characteristics (axial stiffness, volume and maximum von Mises stress) is presented for initial design of the plate and two optimized variants of the design. It has been established that the optimized variants provide a reduction in the plate volume by 49–54 %. In this case, the axial stiffness decreases by 43–53 %, which is a positive effect in terms of minimizing the effect of stress shielding. The optimized variants of the design possess close values of axial stiffness and maximum von Mises stress, however, in one of them, deflection of the axial segments occurs, resulting in an increase in the total strain energy, which is used as an objective function during optimization. In the variant 2 of the design, the deflection of the longitudinal segments of the plate is eliminated due to the presence of a transverse bridge between them, and the total strain energy takes on a lower value. The variant of the design without a bridge should be additionally studied, since shear stresses resulting from the contact interaction of the longitudinal segments of the plate with the bone can have a positive effect on regeneration of the bone tissue.","PeriodicalId":160642,"journal":{"name":"Nauka i Tehnika","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136357072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-10DOI: 10.21122/2227-1031-2023-22-5-387-396
I. I. Bruchkouski, H. S. Litvinovich
This work presents the development and implementation of an autonomous portable spectrometer DEVI (Doas Expedition Volcanic Instrument), designed to measure SO 2 slant columns in volcanic plumes by remote optical method DOAS (Differential Optical Absorption Spectroscopy) in the range of 290–365 nm with a resolution of at least 1 nm. To achieve this goal, the following tasks have been solved: practical implementation of the spectrometer, including design of optical scheme; design of a spectrometer housing for reducing scattered radiation and facilitate adjustments; applying of additional sensors to record measurement conditions; laboratory measurements to determine the spectrometer's characteristics; field measurements and preliminary data processing to retrieve SO 2 slant columns in volcanic plumes. During the spectrometer design phase, numerical simulation methods in the Zemax software have been used, while DOAS was applied for processing experimental data for retrieving SO 2 slant columns. Our laboratory measurements showed that the DEVI spectrometer has a spectral resolution of 0.58 ± 0.5 nm and an angular field of view of 1 × 0.25°. To improve the signal-to-noise ratio, mathematical filter based on the experimentally determined noise parameters of the DEVI detector has been introduced, which allowed us to estimate the SO 2 slant columns in volcanic plumes. DEVI was successfully tested during expeditions to the Kuril Islands in the periods of July – August, 2021 and 2022 (31.07–13.08.2021 and 27.07–29.08.2022). Our field measurements and data processing showed the SO 2 slant column value of (7.5 ± 1.2)·10 17 molecules/cm 2 for the volcano Chirinkotan. Obtained estimation is consistent with known results obtained for other volcanoes.
{"title":"Spectrometer for Estimating SO2 Content in Volcanic Plumes","authors":"I. I. Bruchkouski, H. S. Litvinovich","doi":"10.21122/2227-1031-2023-22-5-387-396","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-5-387-396","url":null,"abstract":"This work presents the development and implementation of an autonomous portable spectrometer DEVI (Doas Expedition Volcanic Instrument), designed to measure SO 2 slant columns in volcanic plumes by remote optical method DOAS (Differential Optical Absorption Spectroscopy) in the range of 290–365 nm with a resolution of at least 1 nm. To achieve this goal, the following tasks have been solved: practical implementation of the spectrometer, including design of optical scheme; design of a spectrometer housing for reducing scattered radiation and facilitate adjustments; applying of additional sensors to record measurement conditions; laboratory measurements to determine the spectrometer's characteristics; field measurements and preliminary data processing to retrieve SO 2 slant columns in volcanic plumes. During the spectrometer design phase, numerical simulation methods in the Zemax software have been used, while DOAS was applied for processing experimental data for retrieving SO 2 slant columns. Our laboratory measurements showed that the DEVI spectrometer has a spectral resolution of 0.58 ± 0.5 nm and an angular field of view of 1 × 0.25°. To improve the signal-to-noise ratio, mathematical filter based on the experimentally determined noise parameters of the DEVI detector has been introduced, which allowed us to estimate the SO 2 slant columns in volcanic plumes. DEVI was successfully tested during expeditions to the Kuril Islands in the periods of July – August, 2021 and 2022 (31.07–13.08.2021 and 27.07–29.08.2022). Our field measurements and data processing showed the SO 2 slant column value of (7.5 ± 1.2)·10 17 molecules/cm 2 for the volcano Chirinkotan. Obtained estimation is consistent with known results obtained for other volcanoes.","PeriodicalId":160642,"journal":{"name":"Nauka i Tehnika","volume":"228 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136357069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-10DOI: 10.21122/2227-1031-2023-22-5-367-375
A. A. Litvinko
The paper describes the technology of hot briquetting of structurally heterogeneous metalworking waste in molds with a movable matrix, which differs from known analogues in the possibility of improving the quality of briquettes with a minimum number of preparatory operations. The aim of the work is to improve the process of hot briquetting. The tasks to be solved are to develop a technological scheme and a physical and mathematical model of the process, reduce the forces of contact friction and tool wear, and optimize the energy-power parameters according to the criteria for the density and strength of briquettes. The technological scheme of briquetting is represented by a mold with a movable matrix, in which compressed air is used as an elastic support. During the briquetting process, the matrix and the pressed metal move in the same direction. The lateral friction force is active, directed towards the briquetting force. As a result, the force and work of briquetting, mold wear are reduced, and the briquette itself is of high quality – uniform in density and without internal defects. As a result of the numerical calculation of the model, the dependences of the stress state of the pressing and pressing pressure on the coordinates and density on the contact surfaces and in the depth of the material were obtained, which makes it possible to calculate the strength of the mold parts and select equipment for the briquetting process. The regularities of formation of the briquette structure are studied, the advantages of using the proposed technological scheme in comparison with briquetting in a fixed matrix are shown. The proposed technology eliminates the implementation of the preliminary operation of coolant removal by centrifugation or other known methods. Coolant is removed by thermal sublimation, partially burned in the furnace firebox, partially condensed in the “wet” cleaning system.
{"title":"Hot Briquetting Technology for Ferrous Metal Waste in Molds with Movable Matrix","authors":"A. A. Litvinko","doi":"10.21122/2227-1031-2023-22-5-367-375","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-5-367-375","url":null,"abstract":"The paper describes the technology of hot briquetting of structurally heterogeneous metalworking waste in molds with a movable matrix, which differs from known analogues in the possibility of improving the quality of briquettes with a minimum number of preparatory operations. The aim of the work is to improve the process of hot briquetting. The tasks to be solved are to develop a technological scheme and a physical and mathematical model of the process, reduce the forces of contact friction and tool wear, and optimize the energy-power parameters according to the criteria for the density and strength of briquettes. The technological scheme of briquetting is represented by a mold with a movable matrix, in which compressed air is used as an elastic support. During the briquetting process, the matrix and the pressed metal move in the same direction. The lateral friction force is active, directed towards the briquetting force. As a result, the force and work of briquetting, mold wear are reduced, and the briquette itself is of high quality – uniform in density and without internal defects. As a result of the numerical calculation of the model, the dependences of the stress state of the pressing and pressing pressure on the coordinates and density on the contact surfaces and in the depth of the material were obtained, which makes it possible to calculate the strength of the mold parts and select equipment for the briquetting process. The regularities of formation of the briquette structure are studied, the advantages of using the proposed technological scheme in comparison with briquetting in a fixed matrix are shown. The proposed technology eliminates the implementation of the preliminary operation of coolant removal by centrifugation or other known methods. Coolant is removed by thermal sublimation, partially burned in the furnace firebox, partially condensed in the “wet” cleaning system.","PeriodicalId":160642,"journal":{"name":"Nauka i Tehnika","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136358864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-10DOI: 10.21122/2227-1031-2023-22-5-411-417
F. A. Romaniuk, V. Y. Rumiantsev, I. V. Novash, Y. V. Rumiantsev
In microprocessor-based distance protection of lines, digital resistance elements are used as measuring instruments for determining the components of the input resistance vector and their subsequent mathematical comparison with the boundaries of the selected response characteristics. The values of the resistance vector components are calculated from the voltages and currents measured at the installation site of the protection. The most common are algorithms for remote measurements of input resistance based on: two samples of instantaneous values of line voltage and current; line models; using orthogonal voltage components and current. In the resistance elements of modern microprocessor line protections for remote measurements, the last of the above algorithms is most widely used. Its dynamic properties are determined mainly by the implemented method of generating the orthogonal components of the input signals. In distance protection measuring device, non-recursive digital Fourier filters are predominantly used for this purpose. To improve the dynamic properties of the remote measurement algorithm based on them, it is proposed to correct additionally dynamic errors in transient modes. In the dynamic modeling environment MATLAB-Simulink-SimPowerSystems, digital model is implemented that allows for a comparative assessment of the dynamic properties of the proposed algorithm for remote measurements of input resistance based on the results of a computational experiment. The research results have shown that the proposed algorithm for remote measurements of input resistance has higher dynamic properties compared to the known ones.
{"title":"Dynamic Properties of Remote Sensing Algorithm in Digital Resistance Elements","authors":"F. A. Romaniuk, V. Y. Rumiantsev, I. V. Novash, Y. V. Rumiantsev","doi":"10.21122/2227-1031-2023-22-5-411-417","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-5-411-417","url":null,"abstract":"In microprocessor-based distance protection of lines, digital resistance elements are used as measuring instruments for determining the components of the input resistance vector and their subsequent mathematical comparison with the boundaries of the selected response characteristics. The values of the resistance vector components are calculated from the voltages and currents measured at the installation site of the protection. The most common are algorithms for remote measurements of input resistance based on: two samples of instantaneous values of line voltage and current; line models; using orthogonal voltage components and current. In the resistance elements of modern microprocessor line protections for remote measurements, the last of the above algorithms is most widely used. Its dynamic properties are determined mainly by the implemented method of generating the orthogonal components of the input signals. In distance protection measuring device, non-recursive digital Fourier filters are predominantly used for this purpose. To improve the dynamic properties of the remote measurement algorithm based on them, it is proposed to correct additionally dynamic errors in transient modes. In the dynamic modeling environment MATLAB-Simulink-SimPowerSystems, digital model is implemented that allows for a comparative assessment of the dynamic properties of the proposed algorithm for remote measurements of input resistance based on the results of a computational experiment. The research results have shown that the proposed algorithm for remote measurements of input resistance has higher dynamic properties compared to the known ones.","PeriodicalId":160642,"journal":{"name":"Nauka i Tehnika","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136357983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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