Весці Нацыянальнай акадэміі навук Беларусі最新文献_第2页

Taking into account a priori information in the iterative reconstruction of images of foundry products 基于先验信息的铸造产品图像迭代重建方法

Весці Нацыянальнай акадэміі навук Беларусі Pub Date : 2023-10-03 DOI: 10.29235/1561-8358-2023-68-3-242-251

S. A. Zolotarev, A. T. T. Taruat, E. G. Bilenko

{"title":"Taking into account a priori information in the iterative reconstruction of images of foundry products","authors":"S. A. Zolotarev, A. T. T. Taruat, E. G. Bilenko","doi":"10.29235/1561-8358-2023-68-3-242-251","DOIUrl":"https://doi.org/10.29235/1561-8358-2023-68-3-242-251","url":null,"abstract":"Methods of restoring images and properties of non-destructive testing objects based on solving inverse problems (problems of restoring distribution functions of unknown characteristics of an object based on the results of indirect measurements) are considered. Management methods are based on solving inverse problems and allow you to get the most complete information about the distributed properties of an object. The need to attract additional information imposes serious restrictions on the development of universal applied algorithms for solving incorrectly set tasks. As a rule, individual additional information is available for each specific non-destructive testing task. An effective numerical algorithm for solving an incorrectly posed problem should be focused on taking this information into account at each stage of the solution search. When solving an applied problem, it is also necessary that the algorithm corresponds to both the measuring capabilities and the capabilities of available computing tools. The problem of low-projection X-ray tomography is always associated with a lack of initial data and can only be solved using a priori information. To introduce the necessary additional information into the numerical algorithm, the methods of iterative reconstruction of tomographic images are identified as the most suitable. One of the approaches to the presentation of this kind of information is described. A practical solution to this problem will expand the scope of the X-ray tomography method.","PeriodicalId":486343,"journal":{"name":"Весці Нацыянальнай акадэміі навук Беларусі","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135743933","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}

引用次数: 0

Clays of the Republic of Belarus as engineering barriers for disposal of radioactive waste 白俄罗斯共和国粘土作为处置放射性废物的工程屏障

Весці Нацыянальнай акадэміі навук Беларусі Pub Date : 2023-10-03 DOI: 10.29235/1561-8358-2023-68-3-252-264

N. A. Makovskaya, T. G. Leontieva, A. A. Baklay

{"title":"Clays of the Republic of Belarus as engineering barriers for disposal of radioactive waste","authors":"N. A. Makovskaya, T. G. Leontieva, A. A. Baklay","doi":"10.29235/1561-8358-2023-68-3-252-264","DOIUrl":"https://doi.org/10.29235/1561-8358-2023-68-3-252-264","url":null,"abstract":"Тhe criteria for compliance with which the properties and characteristics of clays from industrially exploited deposits of the Republic of Belarus were assessed in order to determine the possibility of their further use as part of the underlying screen of the radioactive waste disposal facility (RWDF) of the Belarusian NPP are defined. The performed experimental analysis of clay samples from 12 deposits of the Republic of Belarus showed that clays from the “Gorodnoye” deposits of the Brest region and the “Markovskoye” deposits of the Gomel region have optimal quality indicators for use as part of the RWDF engineering barrier (underlying screen). It has been established that these clay samples have high sorption properties for 137Cs and 85Sr radionuclides. The values of the degree of sorption of 137Cs and 85Sr radionuclides from an aqueous solution for the above clay samples are about 99 %, and the values of the quantitative indicator of sorption the coefficient of distribution of radionuclides – are about 104 l/kg. Over time, the fixation of 137Cs on the studied clay samples increases; as part of the underlying RWDF screen, these clays will be an effective anti-migration barrier to prevent the migration of radionuclides into the environment in the event of depressurization of radioactive waste packages.","PeriodicalId":486343,"journal":{"name":"Весці Нацыянальнай акадэміі навук Беларусі","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135743938","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}

引用次数: 0

Features of structure formation in antifriction composite powder infiltered with copper alloy material based on iron (pseudo-alloy) under high-temperature thermomechanical treatment 高温热处理下铁基铜合金材料(伪合金)渗滤抗磨复合粉末的组织形成特征

Весці Нацыянальнай акадэміі навук Беларусі Pub Date : 2023-10-02 DOI: 10.29235/1561-8358-2023-68-3-196-207

L. N. Dyachkova, P. A. Vytiaz, A. A. Zverko

{"title":"Features of structure formation in antifriction composite powder infiltered with copper alloy material based on iron (pseudo-alloy) under high-temperature thermomechanical treatment","authors":"L. N. Dyachkova, P. A. Vytiaz, A. A. Zverko","doi":"10.29235/1561-8358-2023-68-3-196-207","DOIUrl":"https://doi.org/10.29235/1561-8358-2023-68-3-196-207","url":null,"abstract":"The results of studies of the structure formation process in an iron-based antifriction composite powder material infiltrated with a copper alloy (pseudo-alloy) during thermal and high-temperature thermomechanical treatment (HTMT) are presented. It is shown that after infiltration the structure of the pseudo-alloy consists of sections of the steel skeleton with a perlite structure almost homogeneous in carbon and a small amount of cementite, sections of the copper phase located along the boundaries and at the joints of the particles of the steel skeleton, sulfide inclusions mainly in the copper phase. In the process of hardening, carbon is redistributed in the particles of the steel skeleton; a layer 2–5 µm thick with an increased carbon content is formed at the boundary with the copper phase. During HTMT, the structure is refined, a macrotexture is formed, and the thickness of the copper phase interlayers decreases, depending on the degree of deformation. The degree of deformation also affects the structure of the steel skeleton. After HTMT with a degree of deformation of 30 %, the structure consists of structureless martensite, troosto-martensite and residual austenite, and in the areas adjacent to the copper phase the carbon content is slightly lower, with a degree of deformation of 50 % – structureless martensite, 25 % more austenite content, more uniform distribution of carbon. It has been established that, due to the activation of diffusion processes during deformation during HTMT, molybdenum sulfides decompose and form iron and copper sulfides of various compositions; molybdenum alloys the iron base or forms carbide. The investigation results can be used in the development of high-strength antifriction materials for heavily loaded friction units.","PeriodicalId":486343,"journal":{"name":"Весці Нацыянальнай акадэміі навук Беларусі","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135901417","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}

引用次数: 0

New composite materials for protection against gamma radiation 抗伽马辐射的新型复合材料

Весці Нацыянальнай акадэміі навук Беларусі Pub Date : 2023-10-02 DOI: 10.29235/1561-8358-2023-68-3-183-195

D. I. Tishkevich, S. A. German, А. L. Zhaludkevich, T. N. Vershinina, A. A. Rotkovich, A. A. Bondaruk, S. V. Leonchik, V. S. Urbanovich, E. S. Dashkevich, A. V. Trukhanov

{"title":"New composite materials for protection against gamma radiation","authors":"D. I. Tishkevich, S. A. German, А. L. Zhaludkevich, T. N. Vershinina, A. A. Rotkovich, A. A. Bondaruk, S. V. Leonchik, V. S. Urbanovich, E. S. Dashkevich, A. V. Trukhanov","doi":"10.29235/1561-8358-2023-68-3-183-195","DOIUrl":"https://doi.org/10.29235/1561-8358-2023-68-3-183-195","url":null,"abstract":"A new composite material of W–Bi2O3 system is proposed as a protection against ionizing radiation. An improved method of hot isostatic pressing for the preparation of composite materials is proposed. The duration of sintering under conditions of high pressure and temperature was 3 minutes. The study of the morphology and chemical composition of W–Bi2O3 composites was carried out using scanning electron microscopy and X-ray energy-dispersive spectroscopy respectively. The density evaluation of the obtained materials was carried out using the Archimedes’ method. The densest samples were obtained at a pressure of 5 GPa and temperatures of 25 and 500 °C, the density of which was 18.10 and 17.85 g/cm3, respectively. It is shown that exposure to high temperatures during sintering adversely affects both the microstructure and density of the samples due to the redox reaction accompanied by the reduction of Bi and the oxidation of W. The results of studying the W–Bi2O3 structure by X-ray diffraction analysis showed that all samples include the main body-centered phase W, and the presence of the WO2 phase is noted only when the sintering temperature is increased to 850 °C, which is confirmed by the appearance of reflections 111 and 22-2. Shielding effectiveness of the W–Bi2O3 composite materials from gamma radiation using the Phy-X/PSD software was evaluated. Co60 with an energy of 0.826–2.506 MeV was used as a source of gamma quanta. The simulation results were compared with the calculations for Pb and Bi. Key parameters such as linear attenuation coefficient, mean free path and half value layer are determined. The calculation results showed that the W–Bi2O3 composite surpasses Pb and Bi in its shielding properties, which makes it promising for use as a radiation shielding material.","PeriodicalId":486343,"journal":{"name":"Весці Нацыянальнай акадэміі навук Беларусі","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135901419","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}

引用次数: 0

Expression and purification of recombinant thermostable DNA-binding protein <i>Sso7d</i> 重组热稳定dna结合蛋白<i>Sso7d</i&gt的表达与纯化

Весці Нацыянальнай акадэміі навук Беларусі Pub Date : 2023-09-04 DOI: 10.29235/1561-8331-2023-59-3-225-233

A. B. Sachanka, M. Trawkina, V. V. Shchur, S. A. Usanov, A. V. Yantsevich

引用次数: 0