Pub Date : 2023-08-04DOI: 10.21122/2227-1031-2023-22-4-269-277
A. A. Karatseyeu, M. M. Shukan, K. A. Fiatsisava, A. A. Karatseyeva
Gas-shielded arc welding today occupies a leading position among the methods for producing permanent joints in industrial conditions. The emergence of new materials with complex alloying and hardening systems makes carbon dioxide, traditionally used as a protective medium, inefficient for use. One of the effective ways to solve these problems is to change the composition of the protective gas atmosphere, which allows you to significantly change the physical and metallurgical processes of melting the electrode wire and the forming the weld. At the same time, the transition to the use of protective gas mixtures based on argon is usually carried out without understanding the essence of the technology and possible problems associated with the specifics of penetration of the base metal, which can cause a number of serious problems. The present paper describes important regularities between technological characteristics of arc welding in a shielding gas mixture Ar + CO2 and welding mode parameters under conditions of deviation of their values from the most effective ones in order to ensure the stability of the processes of electrode metal transfer and the formation of the deposited weld metal bead. On the basis of experimental data, the most probable causes of the appearance of a dangerous and difficult-to-detect defect in the formation of a welded seam in the form of non-fusion between individual beads of the deposited metal and along the fusion line with the base metal of the welded parts have been established. The defect is common and can cause unpredictable failure of the welded joint without visible plastic deformation. Empirical dependences for determining values of the main parameters of the welding mode are proposed as well. Important regularities have been established that make it possible to increase the efficiency of arc welding technology in the environment of protective gas mixtures in the conditions of domestic production.
{"title":"Technological Features of Selection of Parameter Values of Arc Welding Mode in Shielding Gas Mixture Ar + CO2","authors":"A. A. Karatseyeu, M. M. Shukan, K. A. Fiatsisava, A. A. Karatseyeva","doi":"10.21122/2227-1031-2023-22-4-269-277","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-4-269-277","url":null,"abstract":" Gas-shielded arc welding today occupies a leading position among the methods for producing permanent joints in industrial conditions. The emergence of new materials with complex alloying and hardening systems makes carbon dioxide, traditionally used as a protective medium, inefficient for use. One of the effective ways to solve these problems is to change the composition of the protective gas atmosphere, which allows you to significantly change the physical and metallurgical processes of melting the electrode wire and the forming the weld. At the same time, the transition to the use of protective gas mixtures based on argon is usually carried out without understanding the essence of the technology and possible problems associated with the specifics of penetration of the base metal, which can cause a number of serious problems. The present paper describes important regularities between technological characteristics of arc welding in a shielding gas mixture Ar + CO2 and welding mode parameters under conditions of deviation of their values from the most effective ones in order to ensure the stability of the processes of electrode metal transfer and the formation of the deposited weld metal bead. On the basis of experimental data, the most probable causes of the appearance of a dangerous and difficult-to-detect defect in the formation of a welded seam in the form of non-fusion between individual beads of the deposited metal and along the fusion line with the base metal of the welded parts have been established. The defect is common and can cause unpredictable failure of the welded joint without visible plastic deformation. Empirical dependences for determining values of the main parameters of the welding mode are proposed as well. Important regularities have been established that make it possible to increase the efficiency of arc welding technology in the environment of protective gas mixtures in the conditions of domestic production.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128307125","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 : 2023-08-04DOI: 10.21122/2227-1031-2023-22-4-308-316
V. Romaniuk, N. Strutsky
Gas distribution system is a production complex, which is part of the gas supply system and consists of organizational and economically interconnected facilities designed to organize the supply of gas directly to consumers. On the national basis of the gas distribution system is formed by about 67.0 thousand km of external distribution gas pipelines, 28.0 thousand km of which are underground steel pipelines. As potentially hazardous objects, steel underground distribution pipelines are subject to higher requirements for corrosion protection. As a rule, they are provided with complex anticorrosion protection, an obligatory component of which is insulation coatings. Taking into account the above mentioned, the definition of general indicators characterizing condition of insulation, the degree of its wear is an actual task. To solve it, for the first time, we have analyzed an array of long-term statistical data on defects of protective coatings of distribution gas pipelines, detected by instrumental method. The values of specific defect density Dd and damageability Ad have been determined for all types of applied protective coatings. The best values have been found for insulation on the basis of heat-shrinkable tapes. The characteristic damage of the protective coating on the basis of bituminous mastics (microcracks), which can be used as an indicator of aging of this type of insulation, has been determined. It has been shown that defect formation in the insulation coatings of gas pipelines up to the present time is, as a rule, a low-intensive process, which has been confirmed, among other things, for gas pipelines operated for a long time. The obtained results were included into the justification of abolition of the previously used 40-year normative service life of steel gas pipelines in the new edition of the Rules of Technical Safety in the Field of Gas Supply of the Republic of Belarus.
{"title":"Applied Insulating Coatings for Gas Distribution Pipelines in the Republic of Belarus and Their Characteristics","authors":"V. Romaniuk, N. Strutsky","doi":"10.21122/2227-1031-2023-22-4-308-316","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-4-308-316","url":null,"abstract":"Gas distribution system is a production complex, which is part of the gas supply system and consists of organizational and economically interconnected facilities designed to organize the supply of gas directly to consumers. On the national basis of the gas distribution system is formed by about 67.0 thousand km of external distribution gas pipelines, 28.0 thousand km of which are underground steel pipelines. As potentially hazardous objects, steel underground distribution pipelines are subject to higher requirements for corrosion protection. As a rule, they are provided with complex anticorrosion protection, an obligatory component of which is insulation coatings. Taking into account the above mentioned, the definition of general indicators characterizing condition of insulation, the degree of its wear is an actual task. To solve it, for the first time, we have analyzed an array of long-term statistical data on defects of protective coatings of distribution gas pipelines, detected by instrumental method. The values of specific defect density Dd and damageability Ad have been determined for all types of applied protective coatings. The best values have been found for insulation on the basis of heat-shrinkable tapes. The characteristic damage of the protective coating on the basis of bituminous mastics (microcracks), which can be used as an indicator of aging of this type of insulation, has been determined. It has been shown that defect formation in the insulation coatings of gas pipelines up to the present time is, as a rule, a low-intensive process, which has been confirmed, among other things, for gas pipelines operated for a long time. The obtained results were included into the justification of abolition of the previously used 40-year normative service life of steel gas pipelines in the new edition of the Rules of Technical Safety in the Field of Gas Supply of the Republic of Belarus.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124347659","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 : 2023-08-04DOI: 10.21122/2227-1031-2023-22-4-301-307
P. Pegin, D. Kapski, A. Ilyin, E. Runev
An assessment of the state of the region’s core road network is necessary to determine the level of transport accessibility and mobility of the population in a particular area. The core road network is the roads along which goods and passengers are transported by personal, public and commercial vehicles. Currently, the assessment of the road network is carried out using geographical, economic, mathematical and general technical parameters. The disadvantage of these assessment methods is the lack of a comprehensive analysis of both the level of development of the core road network and the transport accessibility of the region. The authors propose a method of additive multicriteria modeling using weight coefficients. The parameters have been considered and weight coefficients have been selected, which significantly affect the reliability of determining the sufficiency of the road network. The analysis of individual criteria for the quality of the transport network has been carried out. Based on the use of statistical parameters, the values of the weight coefficients of the additive model have been determined. The proposed method using an additive multi-criteria model is reliable and universal, which makes it possible to comprehensively evaluate the core network of roads in conjunction with other means of communication (railway, air and water transport). In addition, the method can become part of the methodology for substantiating the inclusion of the designed roads in core network of the region.
{"title":"Method to Define Whether the Road Network is Sufficient for the Region","authors":"P. Pegin, D. Kapski, A. Ilyin, E. Runev","doi":"10.21122/2227-1031-2023-22-4-301-307","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-4-301-307","url":null,"abstract":"An assessment of the state of the region’s core road network is necessary to determine the level of transport accessibility and mobility of the population in a particular area. The core road network is the roads along which goods and passengers are transported by personal, public and commercial vehicles. Currently, the assessment of the road network is carried out using geographical, economic, mathematical and general technical parameters. The disadvantage of these assessment methods is the lack of a comprehensive analysis of both the level of development of the core road network and the transport accessibility of the region. The authors propose a method of additive multicriteria modeling using weight coefficients. The parameters have been considered and weight coefficients have been selected, which significantly affect the reliability of determining the sufficiency of the road network. The analysis of individual criteria for the quality of the transport network has been carried out. Based on the use of statistical parameters, the values of the weight coefficients of the additive model have been determined. The proposed method using an additive multi-criteria model is reliable and universal, which makes it possible to comprehensively evaluate the core network of roads in conjunction with other means of communication (railway, air and water transport). In addition, the method can become part of the methodology for substantiating the inclusion of the designed roads in core network of the region.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"32 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120887170","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 : 2023-08-04DOI: 10.21122/2227-1031-2023-22-4-317-325
F. Romaniuk, V. Rumiantsev, Y. Rumiantsev, A. Dziaruhina, P. Klimkovich
In the existing microprocessor-based directional current protection lines from phase-to-phase short circuits, digital power direction elements are used, which, as a rule, are switched on at full currents and voltage according to the so-called 90-degree pattern. With this switching scheme, a “dead” zone appears only in case of three-phase short circuits close to the protection installation site, which make up a small fraction of all possible types of such damage. Nevertheless, its presence is a significant drawback of the power direction organs. The principles of organ execution based on digital operations with orthogonal components of input voltages and currents have been considered. The result of the functioning of the power direction body is reduced to the development of an information sign equal to: one – with the direct direction of power; minus one – when it is in the opposite direction. To eliminate the “dead” zone, the work of the organ is organized using the voltage “memory”. In order to obtain the required duration of the “memory”, frequency compensation is implemented. The study of the effectiveness of the decisions made, as well as the behavior of the power direction control in normal and emergency modes, has been carried out by the method of a computational experiment. In the MATLAB-Simulink-SimPowerSystems dynamic simulation system, models of the electrical system and a digital power direction control have been developed. The results of the research have shown that the joint use of the existing and proposed principles for the implementation of a digital power direction control ensures an increase in its technical perfection and eliminates the “dead” zone while maintaining its stable operation for an arbitrarily long period of time.
{"title":"Principles for Implementation of Digital Power Direction Control in Microprocessor Current Protections","authors":"F. Romaniuk, V. Rumiantsev, Y. Rumiantsev, A. Dziaruhina, P. Klimkovich","doi":"10.21122/2227-1031-2023-22-4-317-325","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-4-317-325","url":null,"abstract":"In the existing microprocessor-based directional current protection lines from phase-to-phase short circuits, digital power direction elements are used, which, as a rule, are switched on at full currents and voltage according to the so-called 90-degree pattern. With this switching scheme, a “dead” zone appears only in case of three-phase short circuits close to the protection installation site, which make up a small fraction of all possible types of such damage. Nevertheless, its presence is a significant drawback of the power direction organs. The principles of organ execution based on digital operations with orthogonal components of input voltages and currents have been considered. The result of the functioning of the power direction body is reduced to the development of an information sign equal to: one – with the direct direction of power; minus one – when it is in the opposite direction. To eliminate the “dead” zone, the work of the organ is organized using the voltage “memory”. In order to obtain the required duration of the “memory”, frequency compensation is implemented. The study of the effectiveness of the decisions made, as well as the behavior of the power direction control in normal and emergency modes, has been carried out by the method of a computational experiment. In the MATLAB-Simulink-SimPowerSystems dynamic simulation system, models of the electrical system and a digital power direction control have been developed. The results of the research have shown that the joint use of the existing and proposed principles for the implementation of a digital power direction control ensures an increase in its technical perfection and eliminates the “dead” zone while maintaining its stable operation for an arbitrarily long period of time.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114965037","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 : 2023-08-04DOI: 10.21122/2227-1031-2023-22-4-286-293
K. E. Povkolas
The paper presents calculations of vibrations of the soil mass when a horizontal inertial barrier in the form of a rectangular concrete slab buried in the ground is placed on the propagation path of vibrations. The damping effect of a surface wave upon its contact with an inertial plate is associated with its reflection, refraction and partial absorption. Theoretical studies have been carried out using the finite element method. The ground medium has been considered as an elastic inertial array bounded by non-reflecting boundaries. Various variants of the geometry of the inertial plate and its spatial arrangement on the surface of the soil medium between the vibration source and the considered point behind the barrier are modeled. The effectiveness of each variant of vibration isolation has been quantified by the value showing how many times the speed of vertical oscillations of the ground behind the barrier decreases compared to the free propagation of surface waves. It is shown that an intensive decrease in vertical displacements occurs starting from the side face of the inertial plate. Here, the amplitude of vertical oscillations decreases by 9,8 times for a concrete slab 15 m long, and by 4,2 times for a 3-meter slab. At a distance of 22 m from the point of application of the dynamic load, the amplitudes decrease by factors of 5.48 and 2.95, respectively, for slabs of 15 and 3 m width. This method of reducing vibro-dynamic effects has a simple design and can be used in cramped conditions of urban development to protect existing and planned buildings and structures.
{"title":"Evaluation of Effectiveness of Application of Horizontal Inertial Barriers to Reduce Vibrations Propagating in Ground Environment","authors":"K. E. Povkolas","doi":"10.21122/2227-1031-2023-22-4-286-293","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-4-286-293","url":null,"abstract":"The paper presents calculations of vibrations of the soil mass when a horizontal inertial barrier in the form of a rectangular concrete slab buried in the ground is placed on the propagation path of vibrations. The damping effect of a surface wave upon its contact with an inertial plate is associated with its reflection, refraction and partial absorption. Theoretical studies have been carried out using the finite element method. The ground medium has been considered as an elastic inertial array bounded by non-reflecting boundaries. Various variants of the geometry of the inertial plate and its spatial arrangement on the surface of the soil medium between the vibration source and the considered point behind the barrier are modeled. The effectiveness of each variant of vibration isolation has been quantified by the value showing how many times the speed of vertical oscillations of the ground behind the barrier decreases compared to the free propagation of surface waves. It is shown that an intensive decrease in vertical displacements occurs starting from the side face of the inertial plate. Here, the amplitude of vertical oscillations decreases by 9,8 times for a concrete slab 15 m long, and by 4,2 times for a 3-meter slab. At a distance of 22 m from the point of application of the dynamic load, the amplitudes decrease by factors of 5.48 and 2.95, respectively, for slabs of 15 and 3 m width. This method of reducing vibro-dynamic effects has a simple design and can be used in cramped conditions of urban development to protect existing and planned buildings and structures.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130465000","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 : 2023-08-04DOI: 10.21122/2227-1031-2023-22-4-278-285
N. S. Gurinenko, E. I. Batyanovskiy
The paper presents the results of studies of the influence of the components of a complex polyfunctional additive on the protective ability of concrete in relation to steel reinforcement of reinforced concrete building structures. In accordance with modern trends in the use of chemical additives in concrete with the aim of a complex effect both on the processes of hardening and the formation of its structure, and on the final physical, mechanical and operational properties of concrete, the additive in question consists of a number of components. It consists of a plasticizing component, accelerating hardening and compacting the structure of hardening concrete, as well as amorphous ultrafine microsilica. The presence of the latter is accompanied by a reaction with calcium hydroxide and its transfer to a bound state in hardening concrete, which creates prerequisites for a decrease in alkalinity (pH factor) in its volume and, accordingly, can create a risk of corrosion of steel reinforcement of reinforced concrete structures. Taking into account this circumstance, studies have been carried out in order to establish the degree of influence of the amorphous ultrafine microsilica present in the composition of the additive on the properties of concrete, including an assessment of its protective properties in relation to steel reinforcement, as well as a change in strength over time (in this paper up to the "age" of concrete in three years from the moment of manufacture of samples of compositions without chemical additives and with the introduction of a complex polyfunctional additive). As a result, an increase in the density, strength of concrete and its operational properties, including the protective ability in relation to steel reinforcement, due to the complex effect of the additive components, has been revealed, including a decrease in the initial water content and an increase in the density of the cement stone and transition zones of its contact with the surface of the aggregate grains in concrete.
{"title":"Protective Аbility of Cement Concrete with Polyfunctional Additive in Relation to Steel Reinforcement","authors":"N. S. Gurinenko, E. I. Batyanovskiy","doi":"10.21122/2227-1031-2023-22-4-278-285","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-4-278-285","url":null,"abstract":"The paper presents the results of studies of the influence of the components of a complex polyfunctional additive on the protective ability of concrete in relation to steel reinforcement of reinforced concrete building structures. In accordance with modern trends in the use of chemical additives in concrete with the aim of a complex effect both on the processes of hardening and the formation of its structure, and on the final physical, mechanical and operational properties of concrete, the additive in question consists of a number of components. It consists of a plasticizing component, accelerating hardening and compacting the structure of hardening concrete, as well as amorphous ultrafine microsilica. The presence of the latter is accompanied by a reaction with calcium hydroxide and its transfer to a bound state in hardening concrete, which creates prerequisites for a decrease in alkalinity (pH factor) in its volume and, accordingly, can create a risk of corrosion of steel reinforcement of reinforced concrete structures. Taking into account this circumstance, studies have been carried out in order to establish the degree of influence of the amorphous ultrafine microsilica present in the composition of the additive on the properties of concrete, including an assessment of its protective properties in relation to steel reinforcement, as well as a change in strength over time (in this paper up to the \"age\" of concrete in three years from the moment of manufacture of samples of compositions without chemical additives and with the introduction of a complex polyfunctional additive). As a result, an increase in the density, strength of concrete and its operational properties, including the protective ability in relation to steel reinforcement, due to the complex effect of the additive components, has been revealed, including a decrease in the initial water content and an increase in the density of the cement stone and transition zones of its contact with the surface of the aggregate grains in concrete.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121550905","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 : 2023-06-08DOI: 10.21122/2227-1031-2023-22-3-256-264
Ya. M. Zhukouski, S. Kravchenko, N. V. Shehova
The paper deals with the actual problem of achieving sustainable development, through ensuring the sustainability of certain sectors of the national economy, in particular the road sector. The concept of “sustainable development” has been revealed and the steps to achieve it in the Republic of Belarus today have been assessed. In addition, an attempt has been made to substantiate the impact of the sustainability of the road sector, as an integral and connecting part of economic entities on the sustainable development of countries and regions. The influence of the road sector on the elements of sustainable development is considered and its further prospects are assessed. For this, it is proposed to consider the impact of road construction at various structural levels: mega-, meso-, macro- and micro-level, which affect all aspects of the road economy, such as design, construction, maintenance and repair, production of building materials and products. The possibility of implementing the concept of nega-resources in the road sector is considered. Nega-resources are understood as such potential resources that are formed as a result of improving the processes of handling the final product by rationalizing its consumption, as well as with initial resources by optimizing individual stages of the production and logistics cycles. A market for nega-resources could be created following the example of the existing market for emissions allowances under the Kyoto Protocol and the Paris Climate Agreement. The road sector today has many promising technologies, the use of which generates a larger amount of nega-resources. So taking into account nega-resources in the life cycle of transport facilities, as well as creating a system of material incentives based on nega-resources, will ensure the sustainability of road construction, and at the same time the sustainable development of the country and the region as a whole.
{"title":"Toward Sustainable Road Infrastructure Through Production of Nega-Resources","authors":"Ya. M. Zhukouski, S. Kravchenko, N. V. Shehova","doi":"10.21122/2227-1031-2023-22-3-256-264","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-3-256-264","url":null,"abstract":"The paper deals with the actual problem of achieving sustainable development, through ensuring the sustainability of certain sectors of the national economy, in particular the road sector. The concept of “sustainable development” has been revealed and the steps to achieve it in the Republic of Belarus today have been assessed. In addition, an attempt has been made to substantiate the impact of the sustainability of the road sector, as an integral and connecting part of economic entities on the sustainable development of countries and regions. The influence of the road sector on the elements of sustainable development is considered and its further prospects are assessed. For this, it is proposed to consider the impact of road construction at various structural levels: mega-, meso-, macro- and micro-level, which affect all aspects of the road economy, such as design, construction, maintenance and repair, production of building materials and products. The possibility of implementing the concept of nega-resources in the road sector is considered. Nega-resources are understood as such potential resources that are formed as a result of improving the processes of handling the final product by rationalizing its consumption, as well as with initial resources by optimizing individual stages of the production and logistics cycles. A market for nega-resources could be created following the example of the existing market for emissions allowances under the Kyoto Protocol and the Paris Climate Agreement. The road sector today has many promising technologies, the use of which generates a larger amount of nega-resources. So taking into account nega-resources in the life cycle of transport facilities, as well as creating a system of material incentives based on nega-resources, will ensure the sustainability of road construction, and at the same time the sustainable development of the country and the region as a whole.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131230718","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 : 2023-06-07DOI: 10.21122/2227-1031-2023-22-3-224-230
P. G. Lasy
The paper considers a mixed problem with boundary conditions of the second kind for a one-dimensional wave equation. The solution to this problem is written in integral form using the Green’s function. For practical use, this solution is of little use, since, firstly, the Green’s function is a trigonometric series and, therefore, its calculation presents certain difficulties, secondly, it is necessary to calculate approximately the five integrals with the Green’s function included in the solution of the problem, and, thirdly, it is extremely difficult to estimate the error of the approximate calculation of the solution. In this work, these difficulties are overcome, namely, simple expression for the Green’s function is found in terms of a periodic piecewise linear function, the integrals included in the approximate solution are calculated using periodic piecewise linear, piecewise quadratic and piecewise cubic functions, and, finally, a simple and efficient estimate of the approximation error is obtained. The error estimate is linear in the grid steps of the problem and uniform in the spatial variable at any fixed point in time. Thus, an approximate solution of the problem with an arbitrarily small error is effectively expressed in terms of elementary functions. An example of solving the problem by the proposed method is given, and graphs of the exact and approximate solutions are plotted.
{"title":"Approximate Solution Using Elementary Functions of Mixed Problem with Boundary Conditions of the Second Kind for One-Dimensional Wave Equation","authors":"P. G. Lasy","doi":"10.21122/2227-1031-2023-22-3-224-230","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-3-224-230","url":null,"abstract":"The paper considers a mixed problem with boundary conditions of the second kind for a one-dimensional wave equation. The solution to this problem is written in integral form using the Green’s function. For practical use, this solution is of little use, since, firstly, the Green’s function is a trigonometric series and, therefore, its calculation presents certain difficulties, secondly, it is necessary to calculate approximately the five integrals with the Green’s function included in the solution of the problem, and, thirdly, it is extremely difficult to estimate the error of the approximate calculation of the solution. In this work, these difficulties are overcome, namely, simple expression for the Green’s function is found in terms of a periodic piecewise linear function, the integrals included in the approximate solution are calculated using periodic piecewise linear, piecewise quadratic and piecewise cubic functions, and, finally, a simple and efficient estimate of the approximation error is obtained. The error estimate is linear in the grid steps of the problem and uniform in the spatial variable at any fixed point in time. Thus, an approximate solution of the problem with an arbitrarily small error is effectively expressed in terms of elementary functions. An example of solving the problem by the proposed method is given, and graphs of the exact and approximate solutions are plotted.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"139 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133461820","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 : 2023-06-07DOI: 10.21122/2227-1031-2023-22-3-248-255
D. N. Mesnik, D. F. Vecherko
he demand for electric vehicles and plug-in hybrids, supported by green technologies and the IT-sector, is making significant changes in the structural transformation of the economy. The coverage of energy and raw materials markets bythe reduction in the consumption of petroleum products does not allow us to assert confidently that tax losses will be compensated by revenues from the increase in electricity consumption, including from the transport infrastructure. This is partly due to different levels of taxation of electricity and oil products. Removing obstacles hindering the development of electric vehicles through fiscal policy is an important prerogative of the state. On the part of the state, timely measures are needed regarding the revision of taxes and tax rates in support of the development of mechanisms for the introduction of environmentally friendly electric transport, plug-in hybrids, adaptive expansion of infrastructure for vehicle categories M, MG, N, NG, as well as minimizing losses from tax maneuvers of foreign trade relations. Investors are more likely to respond to positive market signals, where in many cases government regulation has a significant impact on the sustainable and economically safe formation of the investment climate. The development of electric transport narrows the fleet of cars on internal combustion engines, or on a fossil energy source. The fall in demand for oil products will hold back the replenishment of the budget revenue savings by reducing tax revenues on fuel. In order to avoid loss of economic benefits with the renewal of the car fleet with electric vehicles, the paper examines the mechanism for adapting the motor vehicle service to modern challenges of the global economy.
{"title":"Economic and Organizational Mechanism for Stimulating Development of Environmentally Friendly Technologies in Transport","authors":"D. N. Mesnik, D. F. Vecherko","doi":"10.21122/2227-1031-2023-22-3-248-255","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-3-248-255","url":null,"abstract":"he demand for electric vehicles and plug-in hybrids, supported by green technologies and the IT-sector, is making significant changes in the structural transformation of the economy. The coverage of energy and raw materials markets bythe reduction in the consumption of petroleum products does not allow us to assert confidently that tax losses will be compensated by revenues from the increase in electricity consumption, including from the transport infrastructure. This is partly due to different levels of taxation of electricity and oil products. Removing obstacles hindering the development of electric vehicles through fiscal policy is an important prerogative of the state. On the part of the state, timely measures are needed regarding the revision of taxes and tax rates in support of the development of mechanisms for the introduction of environmentally friendly electric transport, plug-in hybrids, adaptive expansion of infrastructure for vehicle categories M, MG, N, NG, as well as minimizing losses from tax maneuvers of foreign trade relations. Investors are more likely to respond to positive market signals, where in many cases government regulation has a significant impact on the sustainable and economically safe formation of the investment climate. The development of electric transport narrows the fleet of cars on internal combustion engines, or on a fossil energy source. The fall in demand for oil products will hold back the replenishment of the budget revenue savings by reducing tax revenues on fuel. In order to avoid loss of economic benefits with the renewal of the car fleet with electric vehicles, the paper examines the mechanism for adapting the motor vehicle service to modern challenges of the global economy.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126359899","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 : 2023-06-07DOI: 10.21122/2227-1031-2023-22-3-243-247
M. M. Kozhevnikov, V. Nikulin, S. N. Adamov
The traditional pectin production technology is highly energy-intensive and environmentally unsafe. One of the possible ways to improve the technological process of pectin production is to dry directly the petine hydrolyzate before it is precipitated with ethyl alcohol. The most effective method of drying pectin hydrolyzate is drying in a vibrofluidized layer of an inert material, which provides high productivity in terms of evaporated moisture per unit volume of the chamber and the quality of the resulting dry product. This paper proposes a method for optimizing the drying process of pectin hydrolyzatein the apparatus of a vibrofluidized layer of an inert material, which makes it possible to determine the values of regime parame- ters at which the drying process proceeds with minimal costs for thermal and electrical energy. The technique is based on the experimentally obtained relationship between the specific productivity of the drying unit and the following operating parameters of the drying process: the air velocity in the drying chamber, the initial air temperature, the specific load related to the area of the gas distribution grid, the initial concentration for dry substances. On the basis of this experimental dependence, the criteria for assessing the reduced costs for heat and electric energy are formalized. A complex criterion for optimizing the drying process in a vibrofluidized bed is formulated, the minimization of which makes it possible to increase the efficiency of the drying process. Restrictions on the ranges of variation of the operating parameters of the drying process are formulated as well. The posed problem of optimization of the drying process in a vibrofluidized bed is solved numerically using the method of sequential quadratic programming and recommendations are formulated on the values of operating parameters for conducting the process in the optimal mode.
{"title":"Determination of Energy-Saving Drying Modes in Vibrofluidized Bed Apparatus","authors":"M. M. Kozhevnikov, V. Nikulin, S. N. Adamov","doi":"10.21122/2227-1031-2023-22-3-243-247","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-3-243-247","url":null,"abstract":"The traditional pectin production technology is highly energy-intensive and environmentally unsafe. One of the possible ways to improve the technological process of pectin production is to dry directly the petine hydrolyzate before it is precipitated with ethyl alcohol. The most effective method of drying pectin hydrolyzate is drying in a vibrofluidized layer of an inert material, which provides high productivity in terms of evaporated moisture per unit volume of the chamber and the quality of the resulting dry product. This paper proposes a method for optimizing the drying process of pectin hydrolyzatein the apparatus of a vibrofluidized layer of an inert material, which makes it possible to determine the values of regime parame- ters at which the drying process proceeds with minimal costs for thermal and electrical energy. The technique is based on the experimentally obtained relationship between the specific productivity of the drying unit and the following operating parameters of the drying process: the air velocity in the drying chamber, the initial air temperature, the specific load related to the area of the gas distribution grid, the initial concentration for dry substances. On the basis of this experimental dependence, the criteria for assessing the reduced costs for heat and electric energy are formalized. A complex criterion for optimizing the drying process in a vibrofluidized bed is formulated, the minimization of which makes it possible to increase the efficiency of the drying process. Restrictions on the ranges of variation of the operating parameters of the drying process are formulated as well. The posed problem of optimization of the drying process in a vibrofluidized bed is solved numerically using the method of sequential quadratic programming and recommendations are formulated on the values of operating parameters for conducting the process in the optimal mode.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132168043","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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