Izvestiâ Peterburgskogo universiteta putej soobŝeniâ最新文献

{"title":"Multivariate Modeling of Design Parameters of Elastic Clips of Modern Rail Fasteners, with Analysis of Their Stress-Strain State","authors":"Maksim Karyukin","doi":"10.20295/1815-588x-2023-3-507-518","DOIUrl":"https://doi.org/10.20295/1815-588x-2023-3-507-518","url":null,"abstract":"Purpose: To determine the influence of geometric parameters on the most common elastic rod clip used in modern intermediate rail fastenings — the B-shaped clip (such as reinforced concrete rail (RCR) clip and anchor rail fastening (ARF)) — on changes in its stress-strain state. To propose a further direction of improving the design of elastic rod clips of rail fasteners to increase the reliability of the structure. Methods: The article presents the results of multivariate modeling of the geometric parameters of the clips (RCR — 20 pcs., ARF — 13 pcs.) with the analysis of their stress-strain state, using the methods of software and computer systems SolidWorks and Ansys Workbench. Results: Analysis of the design of modern fasteners has shown that the intervals for varying the geometric parameters of the clips (rod diameter, vertical radius, horizontal radius) have small limits and significant limitations associated with the requirements for ensuring the strength, elasticity and operability of the entire fastening. The necessity of considering options with vertical radii less than 60 mm has been revealed, which entails the need for a radical change in the shape of the clips themselves. Practical significance: As a result of the analysis of the calculations of multivariant models, the degrees of influence of the intervals of variation of the geometric parameters of rod clips (rod diameter, vertical radius, horizontal radius) on the stress-strain state have been determined. It is established that in order to further increase the elasticity of the clips, it is necessary to develop a new type of rail fastening with a fundamentally different shape (different from the modern B-shaped) elastic clip that does not have modern design limitations in geometric parameters.","PeriodicalId":476051,"journal":{"name":"Izvestiâ Peterburgskogo universiteta putej soobŝeniâ","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136130688","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":"Accumulation of Heavy Metals in Soils and Phytomass in Urbanized Areas","authors":"Alina Gavrilova, Elena Makarova, Rasul Ahtyamov","doi":"10.20295/1815-588x-2023-3-706-714","DOIUrl":"https://doi.org/10.20295/1815-588x-2023-3-706-714","url":null,"abstract":"Purpose: To carry out a qualitative and quantitative assessment of the content of heavy metals (Fe, Zn, Pb, Cd) in soils and aboveground vegetation organs of plants of the Olive family, namely the common lilac (Syringa vulgaris) growing in urban areas, using the example of the central part of the city of St. Petersburg. To assess the accumulation of iron, zinc, cadmium and lead by soil cover and phytomass, depending on the remoteness of the street-traffic network adjacent to garden-park areas, and the traffic intensity along the studied highways. Methods: The experimental method, based on the “Methodology for determining vehicle emissions for conducting summary calculations of urban air pollution”, has been used to determine the composition and traffic intensity of the traffic flow passing along highways adjacent to the study areas. Subsequently, the obtained data have been statistically processed. A total of 20 sampling points have been identified at the study sites, at different distances from the pollution source. Based on the adopted “Methodological guidelines for determining heavy metals in soils of agricultural lands and crop products”, samples have been taken and further sample preparation has been carried out for research by flame atomic absorption spectrometry. In the laboratory of the testing center “Ecological and Occupational Safety” of the Federal State Budgetary Educational Institution of Higher Education PGUPS, using the method of flame atomic absorption spectrometry, a quantitative analysis of the content of heavy metals (Fe, Zn, Pb, Cd) in selected soil and phytomass samples has been carried out. Results: The quantitative and qualitative composition of the intensity of the traffic flow passing through the central part of the city of St. Petersburg has been determined. The concentrations of heavy metals (Fe, Zn, Cd, Pb) have been determined in all selected soil samples and phytomass at the beginning and at the end of the growing season, leaves of common lilac shrubs growing in the central regions of the city of St. Petersburg. In most samples, elevated concentrations of heavy metals have been found in the aboveground vegetation organs of shrubs taken at the end of the growing season, compared with those taken at the beginning of the growing season. Practical significance: It is shown that the accumulation of heavy metals in plants and soil largely depends on the location of the pollution source and its intensity. The data obtained can be recommended for practical use.","PeriodicalId":476051,"journal":{"name":"Izvestiâ Peterburgskogo universiteta putej soobŝeniâ","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136130267","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":"Methodology for Improving the Efficiency of Operation of Low-Intensity Railway Lines Based on a Logistic Approach","authors":"Konstantin Kovalev, Igor' Sakovich, Alexey Novichihin","doi":"10.20295/1815-588x-2023-3-554-567","DOIUrl":"https://doi.org/10.20295/1815-588x-2023-3-554-567","url":null,"abstract":"Purpose: It consists in developing a methodology for improving the efficiency of operation of low-intensity railway lines based on the use of a set of planning and optimization tools for the functioning of low-intensity railway lines. Methods: Methods of analysis and synthesis, linear and dynamic programming have been applied. Results: A methodology has been developed to improve the efficiency of operation of low-intensity railway lines based on a logistic approach with an assessment of the transport potential of the line and modeling a set of measures to improve the efficiency of their work. Practical significance: The developed methodology is recommended for use in the preparation of work plans to improve the efficiency of operation of low-intensity lines. The methodology makes it possible to determine the potential of low-intensity railway lines for freight and passenger traffic, to select optimal operating scenarios to improve the efficiency of the lines while limiting the budget for their implementation.","PeriodicalId":476051,"journal":{"name":"Izvestiâ Peterburgskogo universiteta putej soobŝeniâ","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136131098","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":"Evaluation of Diesel Locomotive Performance Using Controlled Valves","authors":"Otabek Hamidov, Bahodir Kulmanov","doi":"10.20295/1815-588x-2023-3-577-585","DOIUrl":"https://doi.org/10.20295/1815-588x-2023-3-577-585","url":null,"abstract":"Purpose: Evaluation of the quality of diesel locomotive operation using controlled valves. Methods: Software and data analysis methods are used to evaluate the performance of a diesel locomotive by adjusting and controlling the valve timing. In the process of optimizing drive control, the efficiency values have been considered as a criterion for the optimality of control. Results: The operating modes of the diesel engine of a real diesel locomotive have been investigated and the distribution of its working time by the positions of the driver’s controller has been analyzed. Using a mathematical model of a diesel engine, the main technical and economic parameters of the object under study have been calculated with a change in the valve timing and air flow. Graphs have been analyzed and compiled that characterize the efficiency of changing the valve timing in the form of a dependence of the relative efficiency from cyclic supply for two intermediate modes of diesel operation with varying air consumption. Practical significance: The results of the conducted research can be used in engineering and design work to replace serial gas distribution drives with automatic controlled drives.","PeriodicalId":476051,"journal":{"name":"Izvestiâ Peterburgskogo universiteta putej soobŝeniâ","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136130120","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":"Features of Soil Contamination on the Airport Territory Revealed Through Engineering and Environmental Survey","authors":"Ol'ga Suvorova, Valentina Solov'eva, Mahmud Abu-Hasan, Alina Harlamova","doi":"10.20295/1815-588x-2023-3-715-720","DOIUrl":"https://doi.org/10.20295/1815-588x-2023-3-715-720","url":null,"abstract":"Purpose: To study soil contamination specifics based on the results of engineering and environmental surveys conducted during the airport reconstruction. Detection of toxicants in soil samples during field research on the airport grounds based on the analysis of chemical, bacteriological, parasitological, and toxicological parameters of the samples. The assessment of soil quality compliance with the requirements of sanitary rules and norms ‘Hygienic Standards and Requirements for Ensuring the Safety and (or) Harmlessness of Environmental Factors for Human Habitation’ (SanPiN 1.2.3685—21). Methods: Determination of concentrations of pollutants has been carried out in layers at depths of 0.0–0.2 m; 0.2–1.0 m; 1,0–2,0; 2,0–3,0; 3,0–4,0; 4,0–5,0; 5,0–6,0; 6,0– 7.0; 7.0–8.0 m. The soil samples have been analyzed for the following parameters: heavy metal content (lead, cadmium, zinc, copper, nickel, mercury, arsenic); pH value; content of organic toxicants (polycyclic aromatic hydrocarbons (benzo[a]pyrene); petroleum products); toxicological indicators of the soil throughout the depth (composite sample) (0.0–2.0 meters) (2 test objects: Escherichia coli and Paramecium caudatum). Results: Discrepancies with hygiene requirements for the content of the following chemical substances in soil have been identified: zinc, copper, cadmium, lead, nickel, and petroleum products. The dangerous category of soil has been mostly observed in the surface layer of soil (0.0–0.2 m) and at a depth of 0.2–1.0 m, however, excess soil contamination has also been detected at depths of 2.0–3.0 m and 4.0–5.0 m, and excess soil contamination with nickel has been observed at all horizons up to a depth of 8.0 m. Based on microbiological and parasitological indicators, all samples are classified as “clean”. Practical significance: An analysis of soil contamination levels has been conducted on the territory of the airport in the Tyumen region. Concentrations of ecotoxicants in the soil have been examined, and possible reasons for exceeding the permissible levels of pollutants have been analyzed. Based on the results of the analysis of possible reasons for exceeding the permissible content of pollutants in the soil, the need for measures to protect the soil from further pollutants has been established.","PeriodicalId":476051,"journal":{"name":"Izvestiâ Peterburgskogo universiteta putej soobŝeniâ","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136130383","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":"A Rational Relationship between the Water Quality of a Water Body and the Quality of Discharged Wastewater","authors":"Nikolay Chernikov, Andrey Kudryavcev","doi":"10.20295/1815-588x-2023-3-604-613","DOIUrl":"https://doi.org/10.20295/1815-588x-2023-3-604-613","url":null,"abstract":"Purpose: To develop a methodology for determining a rational relationship between the water quality of water bodies and the quality of wastewater discharged into them with existing investments in the reconstruction of industrial wastewater treatment systems of several water users within one water basin. Methods: Analytical solution of the problem of determining the optimal purity of water in the river in the conditions of implementation of water protection measures with limited financial resources and their rational distribution among water users. Results: Relative financial resources for water protection measures in the Russian Federation are insufficient and at the same time have been declining over the past 30 years. Despite this, the maximum permissible concentrations of pollutants in wastewater discharged into water bodies and wastewater disposal systems in the Russian Federation are often very strict, sometimes even tougher than for drinking water, which leads to unjustified investment costs. It is also noted that at present, market relations in the field of nature management, including in the field of water use, have not yet been fully formed in the Russian Federation. The main difficulties of implementing these relations in this country are outlined. With the help of the proposed methodology, a reasonable relationship between the water quality of a watercourse and the quality of wastewater discharged into them, as well as a rational distribution of financing between water users, is determined on a concrete example. It is shown that the economically justified requirements for effluents discharged into a water body are background concentrations of pollutants in the water of this water body. Practical significance: The practical feasibility of the proposed methodology, which can be recommended for practical application, is demonstrated using an example.","PeriodicalId":476051,"journal":{"name":"Izvestiâ Peterburgskogo universiteta putej soobŝeniâ","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136130517","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":"Budget Sequestration As a Way to Increase the Efficiency of Cost Management in Aviation Activities","authors":"Gennadiy Palamarchuk, Pavel Liberman, Veronika Kuz'menkova","doi":"10.20295/1815-588x-2023-3-586-594","DOIUrl":"https://doi.org/10.20295/1815-588x-2023-3-586-594","url":null,"abstract":"Purpose: To consider the issue of determining and evaluating the effectiveness of cost management in aviation activities. Methods: Methods of systematic analysis of risk management in aviation activities and evaluation of the effectiveness of cost management are used. Results: A study on the problems of cost management in the aviation activities of aviation enterprises has been conducted. A methodology for evaluating the effectiveness of sequestration in aviation activities is proposed. Practical significance: A methodology for assessing and determining the effectiveness of cost management in aviation activities is proposed. Understanding the biggest problems in the world and the aviation industry, as well as cost management in the organization in the future will allow companies to gain a competitive advantage and take a leading position in the aviation services market.","PeriodicalId":476051,"journal":{"name":"Izvestiâ Peterburgskogo universiteta putej soobŝeniâ","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136130128","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":"Research on Fatigue Durability of Side Bearing Springs for Model 18-9891 Bogie","authors":"Denis Danilenko, Viktor Efimov, Vladimir Chernov","doi":"10.20295/1815-588x-2023-3-519-530","DOIUrl":"https://doi.org/10.20295/1815-588x-2023-3-519-530","url":null,"abstract":"Purpose: To conduct comprehensive experimental studies on the fatigue strength of side bearing springs for freight bogies, evaluating the effectiveness of thermal and shot peening treatments during their manufacturing process. Methods: The method of stand endurance (fatigue) testing of constant contact side bearing springs has been applied, allowing for obtaining endurance characteristics of actual components. Metallographic studies of spring steel have been conducted to investigate the influence of strengthening operations during spring manufacturing on their fatigue strength, with the assessment of mechanical characteristics of surface layers in various zones of the helical spatial beam. Results: Experimental force characteristics of spring sets for side bearings of an innovative freight bogie with a load of 25 tons (245 kN) on the axle have been obtained. Fatigue curves of the springs have been presented in a probabilistic aspect, enabling the determination of load factor for fatigue strength of the springs considering operational loading, as well as justifying the compliance of the spring sets with the regulatory requirements. Practical significance: Based on the research results, the considered constructive-technological variant of the constant contact side bearing spring for the freight bogie has been put into serial production. The test results allow us to reasonably determine the warranty mileage of the responsible assembly of the bogie and to conduct further work on the design modernization with the aim of increasing operational life.","PeriodicalId":476051,"journal":{"name":"Izvestiâ Peterburgskogo universiteta putej soobŝeniâ","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136130287","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":"Application of the Internet of Things Technology for Data Transmission from an Automatic Grounding Resistance Meter","authors":"Ol'ga Evdokimova, Sergey Kucenko, Bair Meshkov","doi":"10.20295/1815-588x-2023-3-758-767","DOIUrl":"https://doi.org/10.20295/1815-588x-2023-3-758-767","url":null,"abstract":"Purpose: To organize operational automatic monitoring of the real state of one of the important technical elements of the Directorate of Communications and the Directorate of Infrastructure of JSC “Russian Railways” — of the grounding systems for communication, signaling, centralization and blockage (SCB). Methods: Comparative analysis of the technical characteristics of devices existing in the relevant telecommunications equipment market that implement the Internet of things technology and standard switching solutions for various devices with a unified monitoring and administration system (UMAS). Results: An optimal solution has been obtained for collecting and automatically transmitting information of such a parameter as the electrical resistance of the grounding device. A technical solution is proposed that allows to coordinate the collection of information by means of necessary sensors used in the implementation of the Internet of Things technology, network equipment and the transmission of information to the UMAS by means of a modular diagnostic complex and transmitting devices (switching equipment and multiplexers) provided by LLC “Pulsar-Telecom Design Bureau”. Practical significance: A comprehensive solution for collecting, transmitting and monitoring the condition of the object is proposed, which allows to respond promptly to changes in such an important parameter as the resistance of the grounding device in order to plan the activities of repair, operational and restoration teams and other services of enterprises of the directorates of communications and infrastructure. A comparative analysis of three technologies of the Internet of Things — LoRaWAN, NB-IoT, STRIZH, allowing to assess the advantages and disadvantages of each in achieving the goal.","PeriodicalId":476051,"journal":{"name":"Izvestiâ Peterburgskogo universiteta putej soobŝeniâ","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136130260","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":"Environmental Aspects in the Disposal of Used Coolants","authors":"Aleksandr Haritonenko, Valentina Solov'eva","doi":"10.20295/1815-588x-2023-3-721-730","DOIUrl":"https://doi.org/10.20295/1815-588x-2023-3-721-730","url":null,"abstract":"Purpose: To consider the issue of the state of the problem of collection, disposal and impact of used coolants on the environment, primarily from road transport. To show the need for recycling of spent cooling liquids, the search for new compositions of cooling liquids and the intensification of the collection of spent antifreeze from the population. Methods: Comparing the characteristics of main coolants, highlighting their advantages and drawbacks on the stage of efficiency reduction. Analysis of the types of contaminants accumulating in spent antifreeze. Comparison of advantages and disadvantages of typical methods for purifying spent coolants. Analysis of the growth of sources of anthropogenic impact in the considered area. Results: The most important characteristics of coolants have been established. The most characteristic types of contaminants contained in antifreeze are identified and the most suitable methods of their regeneration are given. The high relevance of the considered problem of the circulation of spent antifreeze as a result of the rapid growth of motorization of the population in the absence of proper control by the state is noted. The necessity of searching for new safe antifreezes while maintaining the target qualities of coolants is revealed. Practical significance: The necessity of revising the attitude to antifreeze in terms of assessing their danger to the environment is shown. The ways of improving the handling of waste coolant solutions in terms of intensifying their collection from enterprises and the public are outlined. It has also been noted that it is necessary to search for new solutions of cooling liquids with a lower content of harmful substances in them to protect humans and the environment.","PeriodicalId":476051,"journal":{"name":"Izvestiâ Peterburgskogo universiteta putej soobŝeniâ","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136130518","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}