The possibility of creating microwave absorbing materials for high-temperature applications by alloying a dielectric matrix based on alumina or Al₂O₃/TiO₂ composite with resistive materials based on titanium Ti–Si–C and Ti–Al–C, heat-resistant iron-based alloys in the FeCrNiAl and FeSiAlTi systems, and the intermetallic compound TiAl with a filler content of 10–60 wt.% is demonstrated. The resistive materials and the intermetallic compound were synthesized by Mechanically Activated Self-propagating High-temperature Synthesis. The heat-resistant alloys were obtained by gas atomization of the initial components mixture. Alloying was performed in a planetary ball mill. The main reflections of the Al₂O₃/Ti–Al–C and Al₂O₃/Ti–Si–C compositions were identified by the lines of α–Al₂O₃, MAX-phases Ti₃AlC₂, Ti₂AlC and Ti₃SiC₂, respectively. The Al₂O₃/TiO₂/TiAl composition contained α–Al₂O₃, TiO₂ and Ti₃Al. In the composites alloyed with heat-resistant alloys, in addition to the α–Al₂O₃ content, the lines of the iron-based solid solution Cr_0.03Fe_0.97 for Al₂O₃/FeCrNiAl, as well as the lines of α–Fe, α–Fe₂O₃, TiAl and slightly Fe₂SiO₄ for Al₂O₃/FeSiTiAl were found. The main parameter of the particle size distribution was d₅₀ = 0.14–36.5 μm. The obtained Al₂O₃-based MAMs with conductive and magnetic fillers in the 8–12 GHz range exhibit a concentration-driven increase of ε′ ≈ 5.6–25.0 and ε″ ≈ 0.5–7.9 as the filler content rises to 50–60 wt.%, reaching maximum losses of tgδ_ε = 0.38–0.55 and tgδ_μ = 0.69–0.80 for magnetic Al₂O₃/FeSiTiAl composites at 50 wt.% filler. At ~35–40 wt.% filler content a percolation-type loss enhancement is observed, accompanied by an increased contribution of ohmic losses. The developed composite materials are recommended for use as radar-absorbing coatings applied by plasma and gas flame spraying on equipment components operating at temperatures up to 1000 °C.

The potential of surface alloying of martensitic, austenitic, and ferritic stainless steels (95Cr18, 04Cr18N9, 03Cr17, respectively) using a ytterbium fiber laser with a maximum power of 2 kW was studied. Powders of a number of chemical compounds were used for alloying: carbides (WC, B₄C, TiC, Cr₃C₂), borides (W₂B₅, TiB₂). A layer of alloying material was preliminarily formed on the surface using the slip method. The thickness of the applied layer was ~ 150 μm. To prevent intense burnout, the treatment was carried out while supplying an inert gas (argon) to the irradiation zone. The effect of alloying modes on the microstructure, microhardness, chemical composition, quality of alloyed zones, and their geometric dimensions was studied. It was noted that the maximum alloyed layer depths were achieved at maximum radiation input of 2 kW and a minimum scanning speed of 1 m/min, ranging from 900 to 1800 µm. Moreover, at maximum energy input, the melt is fairly well mixed, and defects such as pores and cracks are virtually absent. A finely dispersed heterophase structure typically forms in the alloying zone, depending on the type of alloying material and laser processing modes, with precipitation of the original alloying phases or additionally formed ones. Overall, the pattern of microstructure and microhardness changes for the same alloying materials was similar for all the steels studied. The highest microhardness values, ranging from 8300 to 16500 MPa, 6000 to 10000 MPa, and 9500 to 13500 MPa, were achieved in the alloyed layers of 03Cr17, 04Cr19N9, and 95Cr18 steels, respectively, using boron carbide (B₄C). Laser alloying experiments demonstrated the fundamental possibility of surface hardening of ferritic and austenitic steels such as 03Cr17 and 04Cr18N9, and additional hardening of martensitic steels such as 95Cr18. The results obtained can be used to improve operational properties, such as wear and corrosion resistance, of specific products made from these steels.

The paper provides an analysis of the terminology and structural features of high-strength cast irons of the ADI and CADI classes. A rationale is provided for the term “ausferrite” to describe the metallic matrix formed during isothermal quenching. It is noted that the key distinction of the two-phase (ferrite + austenite) bainite-like structure from martensite is the diffusional mechanism of carbon redistribution, which completely suppresses carbide precipitation. Experimental data confirming the mechanism of deformation-induced martensitic transformation (TRIP effect) in CADI alloys, which provides increased strength and wear resistance, are presented. The main focus is on investigating the kinetics of supercooled austenite decomposition in CADI. The influence of the carbide phase on the heterogeneous nucleation of pearlite and ausferrite has been experimentally established and theoretically substantiated, which is reflected in the need to increase the critical quenching rate compared to ADI in order to suppress diffusional decomposition and form an ausferritic structure. The obtained data can find wide application in industry (mechanical engineering, foundry production) in the manufacture of castings for components operating under impact-abrasive wear conditions.

The article presents experimental data processing methods based on generalized stable variables of the drying kinetics of thin, flat, wet materials. The following complex variables were adopted for processing experimental data during convective drying of ceramics, sheet asbestos, felt, and cardboard: generalized drying time, ratio of drying time by periods, ratio of current moisture content to critical moisture content, and relative drying rate. Generalized variables in the drying process, regardless of the drying mode, characterize the most general patterns of drying kinetics. The processing results are presented as a dependence of the relative drying rate on the adopted variables. Equations for drying duration with a minimum number of constants determined empirically are obtained. Based on the heat balance equation for the period of decreasing drying rate, equations for calculating the temperature in the second drying period are given. As a result of processing the drying rate curves for ceramics, asbestos, and felt, the dependence of the relative drying rate on the relative moisture content is obtained. An equation is presented for determining the heat flux density in the second period of drying rate and relative moisture content. A validation of the resulting equations is presented. The error between the calculated and experimental values  is within the accuracy of the experimental data processing, up to 10 %. The presented approxi- mate methods for calculating drying kinetics, obtained by processing experimental data with generalized complex variables, are of interest for the practical drying of capillary-porous wet materials.

A portable optical fluorescence microscope has been developed for evaluating blood samples to perform rapid diagnostics and staging of various diseases by analyzing fluorescent markers and optical cell images. Distinctive features of the microscope include the ability to tilt both the optical axis and the stage equipped with a flow chamber. Tilting the optical axis enables cell movement within the chamber driven by gravity, mimicking the natural flow of cells in the body. This experimental setup allows investigations to be conducted without syringe or peristaltic pumps, which can affect the studied cells, damage them, and complicate the interpretation of analysis results. A series of blood sample studies in flow chambers demonstrated that the developed portable system reproduces results on par with a full-scale stationary fluorescence microscope for platelet thrombus growth on a fibrillar collagen substrate. The compact and portable design of the device ensures easy transportation, enabling research in field laboratories and medical institutions that lack specialized equipment for diagnosing uncommon and rare diseases.

In this paper we report on the synthesis of polycrystalline Cu₂CoGeS₄, Cu₂CoGeSe₄, Cu₂CoSnS₄, and Cu₂CoSnSe₄ compounds and the investigation of their structural and thermoelectric properties. For each sample, the unit cell parameters and melting temperature were determined, and the sound velocity, X-ray density, and Debye temperature were calculated. Cu₂CoGeS₄, Cu₂CoSnS₄, Cu₂CoSnSe₄ crystallize in a tetragonal stannite structure (a/c ≈ 2), Cu₂CoGeSe₄ exhibits an orthorhombic structure. The thermoelectric properties of the compounds researched change in a predictable manner over the range 298–523 K. The Seebeck coefficient increases with temperature for all compounds; Cu₂CoSnSe₄ exhibits the lowest values in the series (135→195 µV/K), whilst Cu₂CoGeS₄ and Cu₂CoSnS₄ exhibit the highest (307→384 µV/K, respectively). The specific electrical resistivity decreases monotonically: from 0.92 (Cu₂CoSnSe₄) to 3.41 (Cu₂CoSnS₄) Ω · cm at 298 K to 0.13 (Cu₂CoSnSe₄) − 0.35 (Cu₂CoSnS₄) Ω · cm at 523 K. Thermal conductivity varies from 2.12 (Cu₂CoGeSe₄) to 3.50 (Cu₂CoSnS₄) W/(m · K) at 298 K and 1.80 (Cu₂CoGeSe₄) − 3.70 (Cu₂CoGeS₄) W/(m · K) at 523 K. The high Seebeck coefficient values combined with low electrical resistivity at elevated temperatures indicate the potential of these compounds for thermoelectric converter applications. The compounds Cu₂CoGeS₄, Cu₂CoGeSe₄, Cu₂CoSnS₄, and Cu₂CoSnSe₄ consist of non-toxic and earth-abundant elements, which meets modern eco-friendliness requirements for thermoelectric materials and opens up possibilities for their practical use in thermoelectric devices.

A new superficial brachytherapy applicator has been developed for the treatment of non-melanoma skin cancer. The proposed applicator demonstrates improved performance characteristics compared to existing counterparts, such as the Leipzig applicator. Key advantages include a reduced wall thickness at the base (1 mm versus 10 mm for the Leipzig applicator), enabling irradiation of tumors located near irregular skin surfaces, as well as a reduction in treatment time by a factor of 2.38–3.45. Dosimetric studies revealed a low dose gradient (up to 20%) within a distance of up to 3 mm from the applicator surface, ensuring more uniform dose distribution. Furthermore, the proposed applicator requires a smaller safety margin (2 mm versus 4 mm for the Leipzig applicator), which enhances positioning accuracy and patient comfort. Experiments were conducted using radiographic film and the Oncentra Brachy treatment planning system, confirming the efficacy and reliability of the development. The results demonstrate that the new applicator has the potential to increase throughput in radiotherapy departments and improve treatment quality for patients with superficial neoplasms .