The results of the specialists’ and scientists’ researches. Рубрика в журнале - Nanotechnologies in Construction: A Scientific Internet-Journal
Статья научная
Introduction. In the context of the global fight against climate change, the reduction of CO2 emissions and its utilization is a topical theme. One of the promising directions is the utilization of CO2 in construction, in particular, in concrete production. The present research investigates the effect of carbon dioxide on the formation of nanoscale structure and physical and mechanical properties of concrete mixtures. Methods and Materials. A special unit for mixing cement, sand, water and CO2 under pressure was developed for the research. The obtained concrete specimen were subjected to compressive and flexural strength tests using MATEST E161-03N automatic dual range testing press. The microstructure of the specimen was also analyzed using scanning electron microscope (SEM). Discussion. The experimental results showed that the introduction of CO2 into the concrete mixture promotes the formation of nanoscale structure, which improves its strength properties up to a certain pressure. With further increase in pressure, deterioration of these characteristics is being observed. Additional mixing time and increase in water volume also affect the strength of concrete and its microstructure. Conclusion. The use of CO2 in concrete production can significantly reduce the carbon footprint of construction materials and improve their physical and mechanical properties due to the formation of nanoscale structure. Further research and optimization of mixing parameters are necessary to create stronger and more stable concrete mixtures.
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The study of the formation of a hollow cellular structure with a given geometry
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Introduction. The use of superplastic forming technology presents a number of challenges, including the lack of experimental and analytical data and the absence of specialized processing facilities. Another crucial factor limiting the widespread use of this methodology is the uniqueness and complexity of the equipment for performing the superplastic forming operation. The study is aimed at determining the optimal shape of the primary blank for the superplastic forming (SPF) process in order to obtain acceptable elongation of the bridges and minimal shrinkage. Methods and materials. Titanium alloy grade VT-6 was used as the material for obtaining the samples. The shape of the initial workpiece was optimized using a model sample, in which the ratio of the height and width of the fillets varied from 3:2 to 3:6 mm. The sample was obtained from a sheet 5 mm thick, by mechanical processing. The two halves of the sample were pre-welded together along the contour using argon-arc welding and sealed after pumping out the air from the cavity between them. Diffusion welding of the sample took place in an autoclave. The SPF was carried out in a limiting container at a temperature of 900±10 °C, argon was supplied according to the law ensuring optimal metal drawing in superplasticity modes. The width of the welded surfaces was from 2 to 4 mm. Modeling and finite element analysis of the SPF process were performed in the MSC Marc software package. The microstructure of the samples was studied using an Altami MET 1C microscope (with a USB 3.0 5 MPix camera). Results and discussion. The results of finite element analysis and a full-scale experiment of SPF are presented to verify the modeling results. During the research it was found that in order to minimize the depth of the resulting sink marks it is necessary to ensure an optimal ratio of the fillet radii equal to 3:5 and 3:6. The difference in the width of the platforms before SPF and the lintels formed after SPF was determined. The smallest narrowing of the lintels is characteristic of the widest platforms. Conclusion. The combined use of finite element modeling and a full-scale experiment made it possible to preliminarily identify the optimal ratio of the height and width of the outer fillet, which allows for acceptable elongation of the bridges and minimal shrinkage.
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Trends in the development of industrial robotic manipulators
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Introduction. Industrial robotic manipulators are becoming an integral part of modern enterprises due to their versatility and ability to perform complex operations with high precision and speed, including in extreme conditions. Effective implementation and operation of robotic manipulators requires an understanding of their design features, control methods, and manufacturing technologies. Main part. This review presents a classification of robotic manipulators based on their design features, number of degrees of freedom, and drive types. Their application areas and market trends are analyzed. This review points to the steady growth of the industrial robotic manipulator market, driven by the transformation of production processes in line with the concept of Industry 4.0. This article examines the structural components of robotic manipulators: the mechanical part, the drive, and the control system. It also presents an overview of modern materials used in the production of manipulators. A method for enhancing the performance properties of structural components through the use of materials with a nanocrystalline structure is proposed. Current development trends in industrial robotics are identified. It is noted that the integration of machine vision and artificial intelligence into manipulator control systems is becoming a key trend in robotics. Such solutions enable rapid response to changing operating conditions and the prevention of potential accidents. Conclusion. Industrial robotic manipulators continue to evolve, opening up new opportunities for automation and increased efficiency in production processes. Their further improvement requires an interdisciplinary approach combining engineering, software, and technological solutions. The results of this review can be used for selecting, designing, and implementing industrial robotic manipulators in enterprises, as well as for further scientific research in the field of robotics.
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