Currently, there is a need for dynamic space missions based on small satellites. These missions can be supported by propulsion systems with thrust-vectoring capabilities. This capability can be realized based on electrodeless plasma thrusters (EPTs). EPTs stand out for their versatility, offering adjustable thrust characteristics and fewer components, making them ideal for small satellites. However, their efficiency remains below optimal levels, largely due to complexities in plasma acceleration. This research aims to better understand dominant acceleration mechanisms in EPTs by studying ion energy distribution function changes based on exhaust orifice diameter and power variations. The total power supplied to the thruster varies in the range of 24 to 40 W, and the exhaust diameter varies in the range from 6.5 to 10.5 mm. It was found that the ion velocity does not change as a function of the diameter of the exit aperture. This indicates the insignificance of the mechanism of the gas-dynamic acceleration of plasma in EPTs with a small form factor and supports recent views that the main contribution to the acceleration of particles in EPT is made by electromagnetic effects. The findings could help refine EPT designs, enhancing their overall effectiveness and reliability for future space missions.

This study discusses the main features of the irradiation of prospective multilayer coatings by VUV/UV radiation from compressed plasma flows. Such radiation is characterized by a broadband spectrum and high brightness fluxes. Oxide and Mo/Si bilayers were used as the basis of the reflective multilayers for the visible and UV ranges. A gas-dynamic response from the irradiated surfaces was studied with schlieren photography. The properties of original and irradiated multilayers were described with ultra violet visible infrared spectroscopy (UV-Vis-IR), X-ray diffraction (XRD), X-ray reflectometry, scanning electron microscopy (SEM) and other techniques. Data on the degradation of optical properties and surface morphology were obtained.

Despite a long period of application of metal implants, carbon–carbon medical composites are also widely used for bone defect prosthesis in surgery, dentistry, and oncology. Such implants might demonstrate excellent mechanical properties, but their biocompatibility and integration efficiency into the host should be improved. As a method of enhancing, the electrophoretic deposition of fine-dispersed hydroxyapatite (HAp) on porous carbon substrates might be recommended. With electron microscopy, energy dispersion X-ray and Raman spectroscopy, and X-ray diffraction, we found that the deposition and subsequent heat post-treatment (up to the temperature of 400 °C for 1 h) did not lead to any significant phase and chemical transformations of raw non-stoichometric HAp. The Ca/P ratio was ≈1.51 in the coatings. Their non-toxicity, cyto- and biocompatibility were confirmed by in vitro and in vivo studies and no adverse reactions and side effects had been detected in the test. The proposed coating and subsequent heat treatment procedures provided improved biological responses in terms of resorption and biocompatibility had been confirmed by histological, magnetic resonance and X-ray tomographic ex vivo studies on the resected implant-containing biopsy samples from the BDF1 mouse model. The obtained results are expected to be useful for modern medical material science and clinical applications.

BACKGROUND: Titanium alloys are widely used in medicine due to their high biocompatibility, corrosion resistance and mechanical strength. However, standard titanium implants have a limited ability to integrate with bone tissue, which can lead to various complications and the need for revision operations. Modification of the implant surface with various biologically active compounds is a promising direction for solving this problem. Among the possible approaches, special attention should be paid to the use of inorganic coatings such as calcium oxides and phosphates, which combine high resistance, corrosion resistance and good mechanical properties. AIM: Determining the modification effect of the titanium (Grade 2) mesh surface on the biocompatibility and osseogenic properties of materials with in vivo experiments using the small laboratory animals. MATERIALS AND METHODS: The titanium mesh surface was modified by microarc oxidation in electrolyte with dispersed hydroxyapatite (HAp). The effectiveness of the surface modification was in vivo tested with a trepanation model in the skull of Wistar rats. RESULTS: The formation of a structured regenerate at the bone surface without a significant defect reduction was revealed. The tissue reaction to the implantation of metal meshes in the defect of the parietal bones of the skull was weak, relatively mature dense connective tissue capsules were formed around the meshes, in which vascularization and inflammatory infiltration were minimal, bone regeneration was observed along the defect edges. Surface modification with microarc oxidation led to more pronounced bone regeneration compared to a surface-unmodified mesh. CONCLUSION: Modification of the surface of the titanium-based mesh by micro-arc oxidation in the electrolyte with dispersed HAp has a positive effect on bone regeneration when closing defects of flat bones.

Objective: In this present research work the behaviour of temperature of the substrate manufactured in AISI H13 steel, in the range of and , during of surface deposition of titanium nitride (TiN) thin films by the technique of cathodic arc in vacuum. Results: The physical properties of the TiN films were obtained and analysed by the techniques of micro-indentation, Atomic Force Microscopy (AFM) and X-Ray Diffraction (XRD). Conclusion: It was determined that the increase in the temperature of the substrate during the deposition of TiN films improves the mechanical properties of the surface of the steel of type AISI H13, where the highest hardness was present in the coating deposited at a temperature of , which has a preferential orientation in the plane determined by the XRD patterns.Keyword: Coatings, Metal substrates, Substrate temperatureResumenObjetivo: En el presente trabajo de investigación se estudia el comportamiento de la temperatura del sustrato, fabricado en acero de tipo AISI H13, en el rango de y , durante la deposición superficial de películas delgadas de nitruro de titanio (TiN) por la técnica de arco catódico en vacío. Resultados: Las propiedades físicas de las películas de TiN fueron obtenidas y analizadas mediante las técnicas la micro-indentación, microscopía de fuerza atómica (AFM) y la difracción de rayos x (DRX). Conclusión: Se determinó que el incremento en la temperatura del sustrato durante la deposición de las películas de TiN, mejora las propiedades mecánicas de la superficie del acero de tipo AISI H13, donde la mayor dureza se presentó en el recubrimiento depositado a una temperatura de , el cual tiene una orientación preferencial en el plano determinada por los patrones de DRX.Palabra Clave: Revestimientos, Sustratos metálicos, Temperatura del sustrato Resumo Objetivo: No presente pesquisa é estudado o comportamento da temperatura do substrato, feito de aço de tipo AISI H13, no intervalo de e , durante a deposição superfície das películas finas de nitreto de titânio (TiN) por meio da técnica de arco catico em vácuo. Resultados: As propriedades físicas dos filmes de TiN foram obtidos e analisados pelas técnicas de micro-indentação, microscopia de força atómica (AFM) e difracção de raios-X (DRX). Conclusão: determinou-se que o aumento de temperatura do substrato durante a deposição do filme de TiN, melhora as propriedades mecânicas da superfície do aço de tipo AISI H13, onde a maior dureza foi apresentada no revestimento depositado a uma temperatura de , que tem uma orientação preferida no plano determinados pelos padrões de DRX.Palavras-chave: Revestimentos, Substratos metálicos, Temperatura do sustrato