Vestnik SibADI最新文献

{"title":"Sound-absorbing aerated concrete based on China fly ash","authors":"Wenxu Xiao","doi":"10.26518/2071-7296-2023-20-4-500-513","DOIUrl":"https://doi.org/10.26518/2071-7296-2023-20-4-500-513","url":null,"abstract":"Introduction . The development of aerated concrete with a high content of open pores, using polymineral binders with reduced cement content and significant utilization of local technogenic resources (in particular, enriched waste from thermal power plants) is relevant for the modern construction industry. To systematize modern methods for studying the characteristics of sound insulation and sound protection of buildings, it is necessary to take into account the diversity of international building codes. The aim of the work is to develop a scientifically based technological solution that provides effective aerated concrete based on fly ash from China with improved sound-absorbing characteristics. Main part . In this paper, a methodological basis, which provides for the comprehensive use of fundamental approaches in building materials science, was used. Integrated design to develop composite materials of a given quality at the nano-, micro- and macrolevels was used. The physical and mechanical properties of raw materials and the required characteristics of the developed materials using physicochemical methods of analysis, including laser granulometry, X-ray phase analysis, scanning electron microscopy, thermal methods, etc were studied. The experimental studies in the laboratories of V.G. Shukhov BSTU, as well as Chinese universities were carried out. Conclusions . In this work, scientific approaches for the design and synthesis of aerated concrete with improved acoustic characteristics in various regions of the country, taking into account local raw materials were formulated. Further research can be aimed at expanding the range of lightweight materials for building envelopes in order to ensure a safe human environment. This can be achieved by synthesizing multicomponent composite binders that affect the formation of nano-, micro- and macrostructures of materials.","PeriodicalId":32892,"journal":{"name":"Vestnik SibADI","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135258915","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":"Vehicle power supply management strategies","authors":"A. V. Puzakov","doi":"10.26518/2071-7296-2023-20-4-474-486","DOIUrl":"https://doi.org/10.26518/2071-7296-2023-20-4-474-486","url":null,"abstract":"Introduction . To optimize the performance of the vehicle electrical system, it is necessary to improve the control principles and strategies. The control principles may be based on voltage constancy, ensuring battery charge, reducing fuel consumption, etc. Materials and methods . A distinctive feature of the first level control strategy is the absence of additional sensors in the power supply system. Their occurence led to the emergence of the second level control strategy aimed at ensuring the starter battery charge, which is achieved by organizing the interaction between the electronic engine control unit and the generator. In the control strategy of the third level the first place is given to the reduction of the vehicle fuel consumption. The target functions of the listed control strategies are considered. Results . The fourth level management strategy, the purpose of which is to reduce the costs of power supply system operation at all stages of the life cycle, is proposed. The structure of power supply system operation costs is considered, which includes the costs of fuel overconsumption caused by malfunctions in the operation of units, as well as the costs of maintenance, diagnostics, repair (replacement) and utilization. Discussion and conclusions . Practical application of the proposed strategy will make it possible to take into account all types of costs and minimize the cost of operating the power supply system for both vehicles with internal combustion engines and hybrid and electric vehicles, in which electricity is even more important.","PeriodicalId":32892,"journal":{"name":"Vestnik SibADI","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135258913","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":"Use of weight measurement algorithm on the basis of moving average filter in the recorder of overhead crane operation parameters","authors":"A. N. Nazarov, S. D. Ivanov","doi":"10.26518/2071-7296-2023-20-4-418-431","DOIUrl":"https://doi.org/10.26518/2071-7296-2023-20-4-418-431","url":null,"abstract":"Introduction . The problem of primary information low quality of crane operation parameters recorders is analyzed. The accepted direction to improve the quality of information about the mass of the cargo is to improve the algorithm of weight measurement. Shortcomings of algorithms of serially produced parameter recorders are described. The design of the algorithm based on the moving average filter is proposed. Materials and Methods . The principle of operation of the proposed weight measurement algorithm is described. The algorithm consists of preliminary (determination of the dynamic process section suitable for weight measurement, calculation of the smoothing window length) and main stages (application of filter, calculation of mass and measurement error). Two methods for determining the length of the smoothing window are given. The parameters of the overhead crane, load cell and motor speed sensor used in the experimental part are given. Results . Graphs of lifting mechanism force and motor rotation speed at the moment of weight measurement are given. The work of the steady-state motion control function is shown. The results of algorithm operation at fixed measurement accuracy of 3% with determination of algorithm operation time and fixed algorithm operation time of 10 seconds with determination of measurement accuracy are given. Discussion . The time of weight measurement with the accuracy required for parameter recorders was 2...5 seconds. Increase in speed of weight measurement is achieved due to adjustable parameters of the algorithm at each switching on of the lifting mechanism. For cranes with duration of lifting time continuously more than 10 seconds the algorithm allows to calculate the mass of the load with an accuracy of 1%. This ensures the accuracy of the crane intensity indicators with an accuracy of 3%. Conclusion . Evaluation of accuracy and time parameters showed the applicability of the developed algorithm of weight measurement in the task of determining the mass of the load to recorders of crane operation parameters. The advantage of the developed algorithm is the guaranteed accuracy of weight measurement. The algorithm of weight measurement allows to adapt the parameter recorder to the technological process of crane operation and effectively use the areas of the dynamic process suitable for measurement.","PeriodicalId":32892,"journal":{"name":"Vestnik SibADI","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135258805","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":"Perspective contact imprint parameters of road roller working body with bearing surface when compacting road materials","authors":"S. V. Saveliev, R. E. Litovchenko, A. A. Yurchenko","doi":"10.26518/2071-7296-2023-20-4-432-442","DOIUrl":"https://doi.org/10.26518/2071-7296-2023-20-4-432-442","url":null,"abstract":"Introduction . The most efficient machine for compacting road building materials in the construction of transport facilities, a road roller with a promising pneumatic tire roller that can effectively use vibration, is considered. Materials and methods . The results of the studies characterizing the parameters of the imprint of the contact of the working body of the roller with the supporting surface, which significantly affect the efficiency of the technological operation of compacting road materials, are presented. During the experiment, the values of the minor and major axes of the contact imprint ellipse, its area, the value of contact pressures depending on the load on the roller and the number of metal bands installed on the roller were revealed. Result . The article provides illustrations of the experiments carried out, the data obtained in the form of analytical and graphical dependencies are presented. Discussion and conclusion . The bandages on standard tires that are mass-produced are installed. The presented promising road roller, which combines the capabilities of different sizes (by weight) of rollers, which can speed up the process of compacting materials, reduce energy, metal and labour intensity and increase the efficiency of road construction.","PeriodicalId":32892,"journal":{"name":"Vestnik SibADI","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135258914","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":"Diagnostics of factors affecting the stability of a construction organization work","authors":"O. A. Pobegaylov, N. O. Sizen, V. M. Dedlovskii","doi":"10.26518/2071-7296-2023-20-4-514-526","DOIUrl":"https://doi.org/10.26518/2071-7296-2023-20-4-514-526","url":null,"abstract":"Introduction . For any construction organization (both for the contractor and the developer), it is important to have an idea of a degree of stability of their work. But for today there is no universal method for identifying such factors and determining the degree of their significance. The purpose of the study was to develop a method for diagnosing factors affecting the stability of the work of construction organizations. Materials and methods . The methodological basis of the work was the general scientific principles and methods of research both empirical methods (experiment and expert evaluation) and theoretical (analysis and synthesis, ascent from the abstract to the concrete, systematization). Risk factors and uncertainties are separated from each other by the criterion of the presence or absence of probability of the occurrence of an event. It follows that risks can be minimized, but uncertainty can only be removed, since it is impossible to minimize something whose magnitude is unknown. The groups of risks affecting the stability of the construction organization, as well as some groups of uncertainties that may affect the construction are identified. An expert assessment of risk factors and uncertainty affecting the stability of the construction organization was carried out, as a result of which diagnostics and analysis of internal and external threat factors affecting the progress of construction were carried out. Results . A model for diagnosing risk factors and uncertainty in modern construction is proposed. Risks and uncertainties are ranked according to the level of their danger for the activities of a construction organization and, in general, for the implementation of an investment construction project. The obtained results of risk ranking help to make management decisions aimed at minimizing the most dangerous risks. For example, to plan the acquisition (leasing) of new equipment, to develop additional measures of social incentives for employees, to check the existing logistics chains, to strengthen financial management, etc. Recommendations are also given for removing uncertainties in the course of the work of a construction organization. Discussion and conclusions . The developed method of diagnosing uncertainty and risk factors can be used by both construction contractors and developers. Moreover, large developers and investors can use it not only in the work of their organization, but also to assess uncertainty and risk in general investment and construction activities. In the future, it is possible to study risk-forming factors, to take into account their mutual influence and the degree of controllability (manageability), to identify those factors that require special attention, as well as to develop a general program for managing risks and uncertainty of an investment project.","PeriodicalId":32892,"journal":{"name":"Vestnik SibADI","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135258911","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":"Studies of adhesive and wear-resistant properties of chrome coatings for car parts and road construction equipment restoration","authors":"A. N. Kotomchin, V. A. Zorin","doi":"10.26518/2071-7296-2023-20-4-458-473","DOIUrl":"https://doi.org/10.26518/2071-7296-2023-20-4-458-473","url":null,"abstract":"Introduction . The use of chrome plating as a method of restoring parts that work with waterjet wear is important for restoring the operability of hydraulic drive units and parts used in specialized vehicles and road construction equipment. The proposed method of chrome recovery has the necessary advantages, it is a sufficiently high performance and microhardness of the resulting chrome coatings. However, for implementation in production, additional studies of the reliability of the chrome coatings obtained, namely, adhesion strength and wear resistance, were required. This will make possible to draw conclusions about the prospects for further implementation and use for the restoration of hydraulic drive parts and other parts that work with waterjet wear. Materials and methods . To conduct the research, equipment meeting the requirements of technical conditions, using existing and developed devices and devices for obtaining chrome precipitation was used. For this purpose, the necessary devices and samples from the appropriate material to approximate the reliability of the obtained research results were made. Also the necessary improvements to digitize the data obtained on the friction machine were made. Results . The performed studies of adhesion strength have shown that the chrome coatings obtained from the new electrolyte composition will make possible to obtain adhesion strength reaching 270 MPa, which is sufficient for parts operating at high pressures (20 MPa) with the necessary margin of safety. Also the studies conducted on the wear resistance of chrome coatings let to conclude that the wear resistance of the chrome coatings obtained is 20-30% higher compared to the reference surface (the material of the spool manufacture). Discussion and conclusion . The studies of the obtained chrome coatings from the new electrolyte composition made possible to establish, which let to establish the regularities of the influence of the electrolyte composition and the modes of testing the wear resistance of the precipitation obtained compared with the existing universal chromium plating electrolyte. The results obtained confirmed the possibility of using a chrome coating from a new chromium plating electrolyte for the restoration of car parts and road construction machines operating under waterjet wear.","PeriodicalId":32892,"journal":{"name":"Vestnik SibADI","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135258912","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":"Reparability and labour intensity comparison for trolleybuses and buses maintenance and repair operations","authors":"A. V. Kolin, P. V. Rybakov","doi":"10.26518/2071-7296-2023-20-4-444-457","DOIUrl":"https://doi.org/10.26518/2071-7296-2023-20-4-444-457","url":null,"abstract":"Introduction . Trolleybuses and buses are the main type of railless public transport. This article examines the factors affecting the cost of transportation, in terms of maintenance and repair of rolling stock in detail. The main purpose of this study is to compare the values of labour intensity for maintenance and repair of trolleybuses and buses and to identify the reasons that affect the difference in the values of labour intensity for maintenance and repair of trolleybuses and buses. Materials and methods . To achieve this goal, the following tasks were solved: 1. The analysis of operating manuals, maintenance and repair instructions, valid during the corresponding periods of operation, for trolleybuses (ZIU-9, BKM-321, PKTS 6281) and buses (LiAZ-677, MAZ-103, MAZ-203) was carried out. The analysis and comparison were made for vehicles of three conditional generations: the 1970s - 1990s, 2000s and 2010s. 2. The reasons influencing the difference in the values of labour intensity of maintenance and repair of buses and trolleybuses are determined. 3. Proposals to amend Order No. 351 of the Ministry of Transport of the Russian Federation have been formulated. Discussion and conclusion . The comparison of the values of the labour intensity of the selected vehicles was made. The recommendations on changing the labor intensity values for maintenance and repair of trolleybuses in comparison with buses, established by Order of the Ministry of Transport of the Russian Federation No. 351, when calculating the initial minimum price of the contract for passenger service by trolleybuses and buses are given. Originality . The comparison of the complexity of performing maintenance and repair operations of trolleybuses and buses in the context of types of equipment and for vehicles of different technical generations is made.","PeriodicalId":32892,"journal":{"name":"Vestnik SibADI","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135258803","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":"Cold resistance of steel beam prestressed by wall drawing","authors":"E. V. Kravchuk, I. Yu. Belutskii, V. A. Kravchuk","doi":"10.26518/2071-7296-2023-20-4-488-499","DOIUrl":"https://doi.org/10.26518/2071-7296-2023-20-4-488-499","url":null,"abstract":"Introduction . The purpose of the article is a generalized analysis of existing methods for determining of structural steel elements behaviour in extreme conditions of subzero temperatures and their use to assess the cold resistance of steel beams prestressed by drawing of a thin wall. Subject of study is structural steel. Object of study is bimetallic steel beam prestressed without rods. Materials and methods . The study is based on the mechanics of deformable solid bodies, studies of the mechanical characteristics of steel and its behaviour at considerable subzero temperatures, taking into account stress concentrators and the probability of brittle cracks in the beam elements. Results . The impact strength analysis of steels C440 and C245 used in the flange plates and wall of prestressed beam was carried out. It is found that during the structure operation in the temperature range from minus 45°C to minus 55°C, cold resistance of the beam elements is ensured. It is proved that actual normal stresses in the extreme fibers of the prestressed beam web section are lower than the allowable stresses during plastic deformation of the wall material and, according to the theory of M. Huber, R. Mises and H. Hencky, the probability of brittle cracks in stress concentrators zone is low. It is found that the absence of stiffeners along the beam wall reduces plastic deformations caused by welding, reduces the number of extra elements in the structure and increases the material’s cold resistance. Conclusions . The high stability of prestressed beam wall enables designing it quite thin and increasing its cold resistance. The stressed state of the structure, reduction of its weight, thinning of wall, absence of welding stress concentrators, and reduction of the number of extra elements in the beam testify to the cold resistance of the material of the beam pre-stressed by wall drawing.","PeriodicalId":32892,"journal":{"name":"Vestnik SibADI","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135258916","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":"Influence of anthropogenic waste of different genesis on properties of fine-grained concrete","authors":"A. V. Iavinskii","doi":"10.26518/2071-7296-2023-20-3-396-404","DOIUrl":"https://doi.org/10.26518/2071-7296-2023-20-3-396-404","url":null,"abstract":"Introduction. The growing amount of stored waste from TPPs has a negative impact on the environmental and economic situation in Russia. The content of ash dumps leads to pollution of nearby areas and increase in energy prices. To solve this problem, it is proposed to use TPP waste as a component of solutions. Materials and methods. The equipment on which the experiment was performed is listed. For the test of compressive strength, the press TP-1-350 Universal was used. For the test of flexural strength, MII-100 machine was used. Specific surface area of TPP waste was determined on PSKh-12 device. The samples gained the strength in the chamber of normal hardening. The chemical composition of TPP waste was determined by the X-ray fluorescent method. Results. The experimental data on the strength of specimens with the replacement of part of the cement by waste thermal power plants of different genesis are presented. The part of the samples were cured under normal conditions, and part was subjected to heat and humidity treatment. Specific cement consumption per unit of compressive and flexural strength was calculated. Compressive strength of mortars with replacement of 20% of cement by Kuznetsky TPP ash makes it possible to obtain samples with strength by 8% less than the control sample under normal curing conditions. The use of acid ash from Omsk TPP and Kuznetsky TPP under heat and moisture treatment makes it possible to obtain the samples with compressive strength higher than the control sample up to 13%. The introduction of 30 % of the basic ash from Novosibirsk TPP instead of cement allows to obtain samples with compressive strength up to 46,55 MPa. The calculation of specific consumption of cement per unit strength showed that the use of the proposed compositions is more cost-effective than the control ashless sample up to 30%. Discussion and conclusions. It has been proved that replacement of up to 30% of cement by TPP wastes makes it possible to obtain mortars with strength not lower than that of the control cement sample. Depending on curing conditions and the type of used TPP waste it is possible to receive samples with compressive strength up to 46,55 MPa and bending strength up to 9,31 MPa. It was found that the use of heat and moisture treatment for the samples using basic ash does not give an increase in strength, compared to acidic ash.","PeriodicalId":32892,"journal":{"name":"Vestnik SibADI","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47282142","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":"Organizational and technological reliability of construction in Iraq","authors":"O. Pobegaylov, Al-Masri Ahmad Abdul Ruda Auda","doi":"10.26518/2071-7296-2023-20-3-388-395","DOIUrl":"https://doi.org/10.26518/2071-7296-2023-20-3-388-395","url":null,"abstract":"Introduction. Capital construction of buildings and structures in the Republic of Iraq is one of the most important areas of production activity, it is the basis for the development of all sectors in the country’s economy. The modern construction complex of Iraq is constantly developing and improving, modern construction materials, technologies, methods of organization and management of construction are being introduced, which makes it possible to implement construction projects of almost unlimited complexity. However, in modern conditions that have been formed in the Republic of Iraq from the end of the 20th century to the present, a special problem has become the need for full and timely provision of construction with all types of resources, which, in the conditions of the Iraqi construction market, is an unsolved scientific and practical task, due to the high influence of negative factors different nature, thereby reducing the organizational and technological reliability of the construction of buildings. Materials and methods. To solve this problem, 7 stages of developing a system of indicators for the sustainable development of resource infrastructure, which will improve the organizational and technological reliability of construction in Iraq are proposed. In addition, a model for calculating generalized criteria for the organizational and technological reliability of construction was developed. To determine the significance of indicators of organizational and technological reliability, it is proposed to use the method of expert evaluation. Results. A system of indicators for the sustainable development of resource infrastructure has been developed, consisting of seven stages. The indicators of organizational and technological reliability of construction are singled out and their significance is determined. Discussion and conclusions. Taking into account the influence of the factors studied by us predetermines the use of the concept of risk as a quantitative measure of the implementation of a negative scenario of the construction progress under the influence of various factors, which allows further research using the apparatus of risk theory. On the basis of the proposed research method, we can calculate the effectiveness of indicators of resource provision for construction in Iraq.","PeriodicalId":32892,"journal":{"name":"Vestnik SibADI","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43315184","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}