Methodological possibilities of positron annihilation lifetime (PAL) spectroscopy applied to characterize different types of nanomaterials treated within three-term fitting procedure are critically reconsidered. In contrast to conventional three-term analysis based on admixed positron- and positronium-trapping modes, the process of nanostructurization is considered as substitutional positron-positronium trapping within the same host matrix. Developed formalism allows estimate interfacial void volumes responsible for positron trapping and characteristic bulk positron lifetimes in nanoparticle-affected inhomogeneous media. This algorithm was well justified at the example of thermally induced nanostructurization occurring in 80GeSe2-20Ga2Se3 glass.

The impact of high-energy milling on glassy arsenic monoselenide g-AsSe is studied with X-ray diffraction applied to diffuse peak-halos proper to intermediate- and extended-range ordering revealed in first and second sharp diffraction peaks (FSDP and SSDP). A straightforward interpretation of this effect is developed within the modified microcrystalline approach, treating “amorphous” halos as a superposition of the broadened Bragg diffraction reflexes from remnants of some inter-planar correlations, supplemented by the Ehrenfest diffraction reflexes from most prominent inter-molecular and inter-atomic correlations belonging to these quasi-crystalline remnants. Under nanomilling, the cage-like As₄Se₄ molecules are merely destroyed in g-AsSe, facilitating a more polymerized chain-like network. The effect of nanomilling-driven molecular-to-network reamorphization results in a fragmentation impact on the correlation length of FSDP-responsible entities (due to an increase in the FSDP width and position). A breakdown in intermediate-range ordering is accompanied by changes in extended-range ordering due to the high-angular shift and broadening of the SSDP. A breakdown in the intermediate-range order is revealed in the destruction of most distant inter-atomic correlations, which belong to remnants of some quasi-crystalline planes, whereas the longer correlations dominate in the extended-range order. The microstructure scenarios of milling-driven reamorphization originated from the As₄Se₄ molecule, and its network derivatives are identified with an ab initio quantum-chemical cluster modeling code (CINCA).

This paper is devoted to the development of hydrogen-containing, environmentally safe, fire-resistant, and corrosion-protected lubricant cooling liquids (LCLs) from vegetable oils with improved sanitary and hygienic parameters for the machining of parts and equipment made from high-strength steels for application during the interoperation period in turbine halls. The use of plant raw materials as ecologically and fire-safe LCLs increased the efficiency of LCLs when evaluating drilling steel in terms of the dependence of the stability of the cutting tool on the drilling speed. Chips formed from LCLs during turning had a compact, cylindrical appearance, and the addition of both water and coolant during turning significantly changed the morphology of the cutting particles. Using water and LCL intensified the physical and chemical destruction processes. After the use of water and LCL, the concentration of hydrogen in the cutting products of 38KHN3MFA steel increased, which indicated its participation in facilitating the destruction during machining. In the chips formed when using LCL, the amount of hydrogen increased by 2.25 times compared to the chips obtained with the dry treatment, while with coolants, it increased by 2.6 times, indicating the intense flow of decomposition products of LCL through diffusion processes in the cutting zone. Hydrogen reduces the energy costs for the destruction of structural and phase components and promotes their dispersion. The creation of 2D and 3D images allowed for a more detailed approach to the study of the influence of LCL on surface treatments.

This paper briefly describes the conceptual direction of the application of computer vision (CV) methods that involve controlling the morphology of hydrogenated wear particles (WPs). During long-term operation, in the surface and subsurface layers of the materials of parts in the tribo-joint, changes in the micromechanisms of fracture occur, which change the morphology of WPs. It has been shown that the developed computer program (CP) can be used to monitor the fractography of the surface of wear particles, and, accordingly, it is possible to control changes in the surface morphology. Therefore, it is possible to predict the operational stability and durability of the tribo-joint. A conceptual scheme for determining the performance of a tribotechnical assembly depending on the determined parameters of WPs is presented. The modes marked on it, including normal operation, transient, run-in, and catastrophic failure, can be evaluated by robotics approaches.

The article describes the impact of hydrogen-containing vegetable fuels consumption with modern injection apparatus. The fuel in question is B100 rapeseed oil ethyl ester. The process of atomizing fuel in the engine at high temperature and in a high pressure chamber plays an important role in the combustion processes in the CI engine. The elements responsible for supplying fuel to the engine’s combustion chamber are the injectors and the injection pump. The paper presents the construction and operation of modern injection pumps and fuel injectors, the methods of their diagnosis are discussed, the important role of precision, and the course of their wear phenomenon are indicated. The paper discusses the impact of hydrogen-containing “green” vegetable fuels on the durability and reliability of injection pumps and fuel injectors used in Common Rail systems. In addition, the tests on the operating parameters of the fuel injector and pump operating on conventional fuel and hydrogen-containing “green” biofuel were carried out.

Rotor shafts are the most heavily loaded and accident-prone parts of powerful turbine generators, which are cooled using hydrogen. To eliminate damage sustained during operations, repair work was carried out, including the removal of defective parts, surfacing, and turning. This study tested the machinability of the rotor shaft using prototypes made from 38KhN3MFA steel. A section of the shaft was degraded due to prolonged operation (250 thousand hours), and compared to the central part, a decrease in the average grain size from 21.57 μm to 12.72 μm and an increase in the amount of hydrogen absorbed during operation from 2.27 to 7.54 ppm were observed. With the frequency of dry turning increasing from 200 to 315 RPM, the chips changed their form from mostly rectangular with linear dimensions of 10 to 20 mm to large spiral rings with a diameter of 15 to 20 mm and a length of more than 50 mm. Cracks of 1 to 4 mm in length were found in most chip particles at both rotational speeds. Increasing the rotational speed from 200 to 315 and up to 500 RPM led to the formation of an oxide film on the surface of the specimens, as evidenced by the appearance of oxygen during local analyses of the elemental content on the chip surface. The saturation of specimens by hydrogen gas led to the formation of finer chips compared to the non-hydrated material, and the roughness of the machined surface increased at hydrogen contents of 6 and 8 ppm. In both dry and coolant cutting operations, surface roughness reflects the degradation of the rotor shaft or experimental prototypes due to hydrogenation, which can be used to diagnose the condition of the rotor after long-term operation.