Science & Technique最新文献

{"title":"Planning of Production Capacities of Precast Construction Plants under Conditions of Changes in Demand for Products","authors":"V. Gurinovich, D. Pozdnyakov, P. I. Yukhnevskiy","doi":"10.21122/2227-1031-2024-23-3-242-250","DOIUrl":"https://doi.org/10.21122/2227-1031-2024-23-3-242-250","url":null,"abstract":"The main criterion for a feasibility study of the production efficiency of precast construction plants, analysis of internal production reserves and optimal production volume is the production capacity indicator. Thus, the study of various Factors influencing the production capacity indicators is an important task. The results of research of the influence of the number of storeys and the set of block sections in the configuration of industrial residential buildings on changes in the ratio of product types in the range of the production programme of plants are presented in the paper. Fluctuations in the ratio of product types during the construction of different types of houses have been established.  Based on the obtained results, the dependence of the production capacity plants on fluctuations in the ratio of product types has been constructed. It has been determined that the main reason for the revealed facts of a decrease in production capacity is the uneven loading of production lines with fluctuations in the ratio of product types in the range of production programs of precast construction plants. Taking into account the known facts of  the dependence of production capacity on the concrete capacity of block sections of houses, the results of a comparison of the degree of influence of concrete capacity on the production capacity and the ratio of the main types of products in the range of production programs of plants are presented in the paper. It has been established that a key influence on the indicators of production capacity is exerted by  changes in the ratio of product types. On the basis of the conducted research, optimal reserves of production capacity have been determined with a high share of different types of houses in the production programs of the plants. Taking into account the established indicators of production capacity reduction, their optimal reservation is within 20–25 % of the design capacity of the plants, which should serve as a reference point when planning the functioning of the production management system under the conditions of changes in demand for products.","PeriodicalId":504191,"journal":{"name":"Science & Technique","volume":"63 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141388249","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}

{"title":"Local Heating System to Improve Comfort of Spectators in the Stands of Indoor Ice Skating Rink","authors":"D. G. Livanskiy","doi":"10.21122/2227-1031-2024-23-3-225-234","DOIUrl":"https://doi.org/10.21122/2227-1031-2024-23-3-225-234","url":null,"abstract":"This paper discusses examples of the use of local heating systems that improve the comfort conditions of spectators, necessary for a full-fledged perception of events at an indoor ice rink. Indoor ice rinks are popular venues for sporting events, concerts and other entertainment events. However, spectators in the stands of indoor ice rinks during a hockey match or a performance of figure skaters often face the problem of low temperature, which, on the one hand, is necessary to maintain high ice quality, but on the other hand,  can be uncomfortable with prolonged stay of the audience. The paper exa-mines the features of heat and mass transfer processes on indoor ice rinks, including convective and radiation heat exchange with the ice surface and the influence of the configuration of ventilation systems on the air environment inside the arena. The study on the need for mathematical modeling for a deeper understanding of the physical processes occurring inside indoor ice rinks. To study the operation of local heating systems, a numerical solution of a system of differential equations is used that describes the processes of heat and mass transfer in the air space of an indoor ice rink. The paper discusses several technical solutions for the organization of local heating systems. The advantages and disadvantages of the above technical solutions are highlighted. A comprehensive analysis of the operation of local heating systems at an indoor ice rink is an important contribution to the understanding the physical processes and parameters that affect the microclimate inside indoor ice rinks, and can also serve as the basis for optimizing such systems in order to ensure comfortable conditions for spectators. ","PeriodicalId":504191,"journal":{"name":"Science & Technique","volume":"31 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141388910","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}

{"title":"Optimization of Aggregate Composition of Asphalt Concrete Mixtures to Ensure Maximum Density","authors":"A. A. Afanasenka","doi":"10.21122/2227-1031-2024-23-3-235-241","DOIUrl":"https://doi.org/10.21122/2227-1031-2024-23-3-235-241","url":null,"abstract":"high strength and stability of asphalt concrete, but also at ensuring optimal characteristics of its structure.The main principles for the optimization of the grain composition are based on the parameters of the size and shape of thе stone aggregate particles included in the composition of asphalt concrete mixtures. An in-depth analysis of the grain composition helps to achieve an optimal balance between coarse and fine fractions, which in turn ensures the stability and durability of the asphalt concrete pavement. The maximum density of an asphalt concrete mixture  plays a key role, influen-cing its physical and mechanical properties and ability to withstand aggressive environmental influences and traffic loads. In addition, the density of the mixture significantly affects its resistance to static and dynamic loads  and deformations, which is important for ensuring road safety. The paper provides an analytical review of the basic principles and methodology for determining the grain composition of fine-grained asphaltic concrete mixtures with grain sizes up to 10 mm in order to achieve their maximum density. Both domestic and foreign methods for optimizing mixture design parameters are considered. Based on the consideration of ideal mathematical curves the grain composition, the main regularity for fine-grained asphalt concrete has been established, which has similar parameters to the mathematical Fourier curve. Understanding and practical application of the principles of constructing the grain composition of asphalt concrete mixtures of maximum density not only improves the quality of road construction, but also contributes to a more efficient use of resources, ensuring the stability and durability of the pavement. This leads to a reduction in road maintenance and repair costs, which is an important  aspect in the context of the economic efficiency of infrastructure projects. Thus, improving the methods for investigating and controlling the grain composition of asphalt concrete is important for the sustainable development of road construction.","PeriodicalId":504191,"journal":{"name":"Science & Technique","volume":"158 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141388742","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}

{"title":"Continuously Variable Two-Flow Hydrostatic-Mechanical Transmission of Crawler Tractor","authors":"Ch. I. Zhdanovich","doi":"10.21122/2227-1031-2024-23-3-251-260","DOIUrl":"https://doi.org/10.21122/2227-1031-2024-23-3-251-260","url":null,"abstract":"The paper proposes an original design of a continuously variable two-flow hydrostatic-mechanical transmission, which ensures division of the power flow along the sides of the crawler tractor. To ensure stability of rectilinear motion, their volumetric and mechanical efficiency, the maximum pressure of the working fluid in the hydraulic transmission, the maximum speed and torque on the shaft of the hydraulic motor. The parameters of an unregulated hydraulic motor, an adjust-table pump and mechanical transmission elements are selected. A mathematical model of the rectilinear motion of a caterpillar tractor with a continuously variable hydrostatic-mechanical transmission has been developed, taking into account the weight of the tractor, the parameters of the running system, the characteristics of the internal combustion engine, the parameters and efficiency of hydraulic machines, gearboxes, range and transfer boxes, planetary gear and allowing to determine the efficiency of individual branches and the entire transmission, carry out traction calculations of the tractor. A calculation program has been developed that implements the mathematical model. The parameters of the dual-flow transmission are selected so that most of the torque is transmitted through the mechanical branch and the transmission has a fairly high efficiency value. The maximum value of tractor traction efficiency is realized in the second and third ranges, which are designed to perform basic tillage operations.","PeriodicalId":504191,"journal":{"name":"Science & Technique","volume":"11 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141388212","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}

{"title":"Structural Transformations of Passenger Transportation Costs by Urban Electric Transport","authors":"V. A. Sinitskaya, T. A. Doilido, D. N. Mesnik","doi":"10.21122/2227-1031-2024-23-3-261-266","DOIUrl":"https://doi.org/10.21122/2227-1031-2024-23-3-261-266","url":null,"abstract":". Transport enterprises of the Republic of Belarus today are at the stage of overcoming the consequences of the COVID-19 pandemic and sanctions pressure related to the peculiarities of the development of its economy. Modern operating cоnditions for enterprises providing passenger transportation services dictate that service providers focus on structural and organizational development, and on increasing efficiency in meeting the changing demands of consumers. Achieving an economic result for this type of enterprise is equivalent to determining a rational ratio of costs for  production, material, financial and labor resources in the process of providing transport services. The processes of agglomeration of passenger transportation in suburban traffic, urbanization, as well as the emergence of technologically new means of personal mobility have intensified restructuring of passenger flows in public transport services. In suburban and urban passenger transportation, road and rail transport is most often involved, and  inland water transport is less common. Passenger transportation is carried out by various types of ground transport: buses and electric buses, trolleybuses and trams, taxi cars and also transport owned by citizens, the competition between which depends on the ratio of price parities of a carrier and the level of consumer income. In this regard, it is necessary to revise price and non-price measures of flexible response of transport carriers of passengers in the process of providing socially significant services. This paper examines the essence of services for the transportation of passengers in regular traffic within the boundaries of the territory of Minsk in relation to the current level of development of the transport and logistics system of the Republic of Belarus. The purpose of the study was to develop proposals for calculating the cost of transport work for passenger transportation using the example of the electric transport fleet in Minsk.","PeriodicalId":504191,"journal":{"name":"Science & Technique","volume":"32 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141388361","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}

{"title":"Using Risk Points in Risk Management System of Thermal Power Plants","authors":"Ya. I. Tymul","doi":"10.21122/2227-1031-2024-23-2-172-180","DOIUrl":"https://doi.org/10.21122/2227-1031-2024-23-2-172-180","url":null,"abstract":"In modern conditions, regardless of what type of economic activity an organization faces various risks. For manufacturing enterprises, the area of risks is one of the most extensive, since it is necessary to take into account uncertainties in both financial and production activities. Creation of  an effective risk management system determines ways and opportunities to ensure sustainability of organizations and their ability to withstand adverse situations. Risk reduction is possible through risk management, which involves their identification and assessment, as well as the use of procedures and management me-thods that would  reduce possible risks. For the most effective implementation of risk management, a systematic approach to organizing this process is required. Risk management will be of particular importance for energy companies due to the changes that have been observed in this area over the past few years. The paper proposes a risk management model for energy enterprises, which includes the goal, object, subject, functions, principles and processes of risk management, taking into account the characteristics of energy enterprises. An algorithm for implementing this model is presented, consisting of five main stages. The use of this algorithm will allow us to obtain intermediate results from the implementation of the risk management system and, if necessary, adjust this process. The paper presents an analysis of existing concepts on the use of risk points. Attention is also paid to the issue of using this method at energy enterprises in other countries. The methodology for determining critical control points, which lies in at the heart of HACCP (Hazard Analysis Critical Control Point) system used in the food industry, is discussed in detail. The possibility of using risk points to determine those responsible for risks at energy enterprises is substantiated. An analysis of the operating thermal power plant was carried out in order to identify points of production and technical risk. The result of the analysis was the identification of those responsible for this type of risk.","PeriodicalId":504191,"journal":{"name":"Science & Technique","volume":"19 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140739690","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}

{"title":"Comparative Analysis of Property Changes in Modified Asphalt Concretes Depending on the Modification Method and Polymer Concentration in the Binder","authors":"P. P. Yatsevich","doi":"10.21122/2227-1031-2024-23-2-140-150","DOIUrl":"https://doi.org/10.21122/2227-1031-2024-23-2-140-150","url":null,"abstract":"The widespread use of polymers of various types for modifying asphalt concrete mixtures poses the task of determining the most optimal method for their introduction into the composition of asphalt concrete mixtures. The study considers options for dry introduction and pre-modification of bitumen. In this context, changes in the properties of asphalt concrete that reflect the material performance in a wide range of temperature are assessed. Technological aspects during construction of the pavement are also taken into account, depending on the quantitative concentration of the polymer modifier in the binder. The research has clearly demonstrated that the optimal way to achieve  high-temperature properties of asphalt in terms of polymer consumption, is pre-modification of bitumen, which allows optimizing the distribution of the modifier throughout the volume of the asphalt concrete mixture. Additionally, the research has shown that asphalt concretes with a high binder content are preferable for modification because bitumen is the primary component in interaction with polymers, and the thicker the bitumen film, the more optimally this process occurs. In addition, the studies have  revealed the negative influence of relatively high thermoplastic content on the low-temperature and technological properties of asphalt concrete mixtures, which can lead to a decrease in the resistance of asphalt concrete to corrosion damage.","PeriodicalId":504191,"journal":{"name":"Science & Technique","volume":"42 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140737591","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}

{"title":"The Influence of Road Adhesion Coefficient on Energy Consumption and Dynamics of Battery Electric Vehicles","authors":"Nhan Thanh Le, Phuc Hoang Dam, Tai Minh Hue Le, S. V. Kharytonchyk, V. Kusyak, Cong Thanh Nguyen","doi":"10.21122/2227-1031-2024-23-2-151-162","DOIUrl":"https://doi.org/10.21122/2227-1031-2024-23-2-151-162","url":null,"abstract":"Currently, in economically developed countries, electric vehicles are considered as a solution to the problematic issue of reducing greenhouse gas emissions from road vehicles. The level of energy consumption is a critical factor in determining the overall performance of an electric vehicle. The article analyzes the influence of tire adhesion coefficient on the energy consumption of a battery electric vehicle when operating in typical standard driving cycles. In order to estimate the energy consumption during driving with different tire adhesion coefficients an electric vehicle longitudinal dynamic model is used, which allows taking into account various driving modes (Eco, Comfort, Sport) and sliding of the drive wheels in contact with the road surface. The proposed model, based on submodels of such main components of an electric vehicle as an electric motor and a traction battery, includes tire and vehicle body dynamics submodels, as well as a human-driver submodel with PID controller in the control circuit to track given trajectories. A series of experiments with the VinFast Vf e34 passenger electric vehicle on a dynamometer test bench were carried out to determine the electric motor’s performance characteristics at various operating modes and identify many other input parameters for simulation and verifying the mathematical model accuracy. The simulation results of the distance traveled by an electric vehicle on a single charge are compared withthe manufacturer's experimental data during operating the test vehicle in the standard European driving cycle. Simulation scenarios with different accelerating modes are proposed to analyze the influence of the adhesion coefficient on the EV’s dynamic characteristics and the level of energy consumption. The simulation results on the determination of the energy consumed by an electric vehicle when moving in various driving cycles with road adhesion coefficients are presented in the activity. The given results show the significant impact of the adhesion coefficient on electric vehicle energy consumption in various standard driving cycles, especially on low-grip roads. ","PeriodicalId":504191,"journal":{"name":"Science & Technique","volume":"33 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140737646","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}

{"title":"Road Safety Concept in the Republic of Belarus","authors":"D. V. Kapski, S. V. Bogdanovich, E. N. Kot, L. V. Khmelnitskaya","doi":"10.21122/2227-1031-2024-23-2-163-171","DOIUrl":"https://doi.org/10.21122/2227-1031-2024-23-2-163-171","url":null,"abstract":"The general trend of accident rate reduction, which has been observed in the Republic of Belarus since 2010, reversed in 2017–2018. Remaining within the framework of the country’s traditional engineering activities related to road maintenance is unlikely to  significantly improve road safety. A transition to qualitatively new practices and mechanisms for ensuring road safety is required. In order to implement this transition, a second Road Safety Concept has been developed. The Concept is based on the Safe System approach, which offers the implementation of measures in four areas: improving road infrastructure safety, increasing vehicle safety, ensuring safe speeds, and training safe road users. The main threat to the implementation of the Safe System approach in the Republic of Belarus is the fixation of stakeholders on their narrow corporate interests and the unwillingness to take into account  nation-wide road safety. The Concept mainly focuses on the “Safe Road Infrastructure” component. A transition to sustainable road safety and the introduction of a Forgiving Road approach are included in the Concept. The introduction of assessment of infrastructure projects impact on traffic safety, traffic safety audit and inspections, road traffic risk assessment, and elimination of accident hotspots are also specified. The introduction of road safety audit is considered an important milestone in the transition to the Forgiving Road approach. The development of Intelligent Transportation Systems is included for the same purpose. Despite the fact that the Concept sets reasonably realistic goals, there are certain concerns about the feasibility of their achievement. This is due to significant institutional problems, such as the lack of a single coordinating body and the complexity of interdepartmental interaction.","PeriodicalId":504191,"journal":{"name":"Science & Technique","volume":"4 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140735757","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}

{"title":"Сonstruction of Facades of Brick Buildings from Prefabricated Insulated Brick Panels (Piers) of Factory Manufacture","authors":"N. Chernoivan","doi":"10.21122/2227-1031-2024-23-2-121-127","DOIUrl":"https://doi.org/10.21122/2227-1031-2024-23-2-121-127","url":null,"abstract":"The high labor intensity of constructing  insulated brick walls has led to a significant reduction in brick consumption in the Republic of Belarus. Considering that in each region there is at least one brick factory equipped with modern technological equipment, and the reserves of mineral raw materials (sand, clay) for making bricks are practically inexhaustible, the development of an effective structural and technological solution for insulated brickwork is an urgent task. As practice shows, today the majority of brick buildings being erected are low–rise (3-5 floors) – these are secondary schools, kindergartens, clinics, buildings for household purposes (laundries, dry cleaners, etc.), as well as administrative buildings. The floor layout of the premises of these buildings is, as a rule, cabinet (the number of window openings is significant). In this regard, it is proposed to use factory-made insulated brick panels (piers) to reduce the labor intensity of constructing the facades of such buildings. A distinctive feature of the proposed solution for insulated brickwork from those commonly used is that, to increase operational efficiency, it is made of two separate structural elements: load-bearing and heat-insulating and decorative. The paper describes in detail the organization and technology of work on the production of the main structural elements of brick insulated facade panels (piers) in factory conditions. The proposed design solution for the facade of brick buildings with a cabinet layout allows the manual technological process of constructing such buildings to be converted into a mechanized one – installation of factory-made insulated brick panels (piers), which will significantly reduce the labor intensity of constructing insulated brick walls. The division of buildings under construction into tiers, the height of which is linked to the range of technological operations and the building materials used, makes it possible to exclude from the work the use of lifting equipment (scaffolding), as well as the delivery of pallets with bricks and mortar boxes to the bricklayer's workplace.","PeriodicalId":504191,"journal":{"name":"Science & Technique","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140741486","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}