The results of studying the structure and properties of two compositions of porous composite materials of the CaO–MgO–FeO(Fe2O3)–Al2O3–SiO2 system based on basalt fiber formed during thermal cycling are presented. The samples made from the mixture of composition I had the following structure: basalt fiber (37 wt.%) + mullite-silica fiber (19 wt.%) + modifier Al 2(SO4)3 as a binder (11 wt.%) + blowing agent (19 wt.%) + porcelain as a hardener (4 wt.%) + plasticizer (11 wt.%); II composition: basalt fiber (52 wt.%) + SiO2 (15 wt.%) + blowing agent (1 wt.%) + porcelain (aluminosilicate) as hardener (6.5 wt.%) + plasticizer (CMC, 6.5 wt.%) + limestone flour (calcium carbonate, CaCO3, 19 wt.%). Thermal cycling was carried out in three temperature ranges of 750–770 °C, 1025–1075 °C, 1070–1090 °C in order to obtain certain structure and properties of composites pressed under pressure of 20, 40 and 60 MPa. To control surface morphology, changes in phase composition, amorphousness and fine structure parameters, porosity, permeability and strength properties, samples were evaluated at each process cycle. On the basis of established patterns of structure formation, modes of formation of pore space are proposed with preservation of porosity not lower than 45 %, strength 5–25 MPa, shrinkage in the process of sintering – not more than 20 %. The studied composite materials can be used to create filter elements of systems for separating, cleaning, converting liquid and gaseous media.

The technological characteristics of BYTC carbide inserts produced by the Institute of Metal Technology of the National Academy of Sciences of Belarus with TiN, TiAlSiCr, TiAlN, and TiAlCrN plasma coatings have been studied. It has been shown that the main phase of the coatings has a cubic structure, which provides them with high hardness (TiN – HV 2414; TiAlSiCr – HV 3570; TiAlN – HV 2692; TiAlCrN – HV 2647) and a low coefficient of friction (0.25–0.40). A 2.0–4.0 μm thick solid film with a microhardness of 2414–3570 HV was applied to a carbide plate using vacuum deposition (PVD) technology. It has been established that the most promising coatings for industrial use are TiN coatings due to their relative simplicity of technology and lower cost of application, as well as their relatively long service life, which ensures an increase in the durability of BYTC PNUA 110408 carbide inserts produced by Institute of Metal Technology of the National Academy of Sciences of Belarus with a TiN coating by a factor of 4.1 when processing 08ХГСДП corrosion-resistant steel. The developed coating can be used in the manufacture of metal-cutting carbide tools (milling cutters, drills, plates, etc.).

This study addresses the problem of contact interaction between the rollers of a mine hoist cage (elevator) and the guide conductors during the operation of a hoist system in a ventilation shaft, taking into account the dynamics of airflow. The influence of various operating modes of the ventilation system, as well as the movement of the cage and counterweight, on the parameters of the contact interaction arising between the cage rollers and guide conductors has been investigated. A numerical model of the contact interaction between the cage rollers and mine guide conductors has been developed based on the finite element method. The constructed finite element model allows for the assessment of the stress-strain state of the structural elements of the guiding devices under various configurations of force exerted by the cage, as well as for determining the magnitudes of critical loads that can cause residual deformations in the guide conductors. Analysis of the research results has shown that aerodynamic forces arising during the operation of mine hoist complexes significantly influence the stress-strain state of this geotechnical system, highlighting the necessity of accounting for them in the design of mine hoist components. The obtained results can be used to ensure the safe and failure-free operation of mine hoist complexes by optimizing their designs during the planning stage to minimize stresses in the contact node between the cage rollers and mine guide conductors, as well as to develop recommendations for replacing guide devices under conditions of multi-cycle loading from the cage rollers.

Taking into account the practical experience gained at the Starobinski Deposit, the four variants of technological schemes for layered extraction of the Third Potash Seam at a depth of over 900 m were developed. The comparison of the presented variants of technological schemes was carried out according to the following indicators: the specific volume of the mining and preparation work; the average content of potassium chloride and insoluble residue in the ore; the volume of ore extraction in the standard; the coefficient of the useful component extraction from the subsoil. It was noted that technological schemes with a sequential order of extraction pillars mining, where extraction (panel) workings are carried out separately for the upper and lower longwalls are more effective, and the presence of an inclined section in the upper longwall is a significant disadvantage that complicates the operation of the face conveyor and leads to a deterioration in ore quality. It is proposed to select a specific variant of layered extraction of the Third Seam with the involvement of the 4th sylvinite layer in the development at depths of more than 900 m taking into account the mining-geological and mining-technical conditions of a specific section of the mine field, since the data presented in the work indicate an insignificant difference in the variants of technological schemes for all accepted indicators for comparison. The process flow charts will be used in the development of projects for the development of mining pillars using layered longwalls and will be included in the relevant regulatory documents of JSC “Belaruskali”.

A brief analysis of current developments, research, and applications of two-phase thermosyphons in engineering is provided. The most relevant application of thermosyphons today is electronic cooling. (power and microelectronics). Other possibilities for using this heat exchange element were also considered: soil temperature stabilization, permafrost preservation, cooling of heat-loaded equipment, heat exchanger for air conditioning systems, nuclear industry. Working fluid selection, optimal filling factor of the device, heat transfer intensifying methods, and the thermosyphon design influence on its performance were examined in detail.

This article provides a brief overview of new technologies developed for use in construction in cold regions of China. These technologies aim to significantly reduce environmental impacts, lower winter heating costs, and create comfortable living spaces during high summer temperatures. Chinese scientists have created ultra-low-energy buildings that are not connected to the central heating system. The following technical solutions are proposed for highly efficient heat conservation in residential spaces during the winter: a prefabricated building structure integrated with a solar heating system; the use of heat accumulators; and the development of a geothermal tunnel ventilation and heating system. To reduce indoor temperatures in the summer, the installation of sun protection systems, as well as thermally insulated roller blinds on doors, windows, and external walls, is proposed. These technological advances have been shown to significantly reduce building operating costs and carbon emissions. The implementation of this integrated technology in the construction of residential buildings in cold climates will enable the commissioning of heating systems without the need for public heating and will reduce carbon emissions over the entire life cycle.

The term “source” is defined in the article on the basis of international terminology as a value representing the physical and chemical form, as well as taking into account the time of release of fission products and other aerosols from core materials and concrete into the atmosphere of the primary containment or into the suppression pool. Chemical forms of fission products and radionuclides that can be released from the cores of modern light water reactors are considered. Modeling of the dynamics of the spread of the source of radioactive substances was simulated using the COMSOL Multiphysics software package using the LES method with the Smagorinsky subgrid model. Physically consistent results were obtained, indicating that the model functions correctly. A mechanism was developed to analyze the propagation of multicomponent flows under the containment of NPP-2006. The work will help to clarify the data needed to improve the model created using the COMSOL Multiphysics software package for simulating the spatial distribution of multicomponent gas flows and radioactive aerosols under the сontainment of NPP-2006 during accidents involving the release of radioactive substances and fission products.