International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

In the present study, a combined approach for the synthesis of multicomponent coatings in the SiO₂–CaO–P₂O₅ system was developed using a sol-gel process combined with electrochemically assisted deposition. Tetraethylorthosilicate (TEOS), calcium nitrate (Ca(NO₃)₂) and citric acid (C₆H₈O₇·H₂O) were used as precursors. The obtained materials were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The formation of amorphous-crystalline structures characteristic of bioactive silicate-calciumphosphate systems was established. The combined approach demonstrates effective control over the structure formation processes and allows the preparation of multicomponent oxide coatings with potential for application in bioactive and functional surface systems

Obtained experimental self-cleaning coatings (based on compositions with the participation of Sm2O3), applied by the sol-gel method on glass slides. This study attempts to improve the overall efficiency of a photovoltaic solar panel by using a Sm2O3 doped ZrO2 (SDZ)-based coating. The optical characterization and phase composition of the obtained experimental samples were investigated using UVVIS- NIR, XRD and XRF methods. The coatings are nanocrystalline according to XRD and XRF analyzes and show transmittance close to that of pure glass when tested with a UV–VIS–NIR spectrophotometer The experimental results represent a prerequisite for the development of a series of additional compositions and a detailed technological regime for obtaining various modifications of resistant, long-lasting selfcleaning coatings, potentially applicable to photovoltaic panels.

The efficiency of photovoltaic (PV) systems is significantly influenced by surface contamination, which can reduce light transmission and energy conversion performance. In this study, self-cleaning nanostructured coatings based on titanium dioxide (TiO₂ ), zirconium dioxide (ZrO₂ ), and their doped and composite variants (with Y₂ O₃ and Eu₂ O₃ ) were synthesized using the sol-gel method and applied to photovoltaic glass substrates. The coatings were characterized in terms of their optical transmittance, surface morphology (AFM), wettability (contact angle), and crystallographic properties (XRD). Results indicate that TiO₂ coatings offer superior superhydrophilic behavior, while stabilized ZrO₂ -based composites show excellent transparency, surface homogeneity, and long-term durability. Eu₂ O₃ -doped coatings exhibit additional luminescent functionalities, potentially useful for photonic enhancement. These findings highlight the potential of sol-gel coatings in improving PV panel performance via integrated passive cleaning mechanisms and multifunctional surface engineering.

A solution was synthesized in a system ZrO2-CeO2 by sol-gel synthesis and deposited by the immersion method. The pretreated Nb substrate was treated with sulfuric acid and absolute alcohol solutions. Layering was in three stages. The sample was heat treated at 500°C. The obtained results are characterized by XRD, XPS, CEM analyzes.

XRD, SEM-EDS and FTIR were used for studying stable products of nuclear reactions of “branching decay” in LiF exposed to  intensive 1.17 and 1.33 MeV 60Co y-radiation to dose 109 R and mixed neutron+y-fluxes of WWR to fluencies 1017-1018cm-2: 19F9 + y -> 11B5 + 7Li3 + 1H1 or -> 16О8 + 3Т1 and 19F9 + 1n0 -> 20Ne10 or ->210B5 in addition to the known 6Li(n,a)3T. The main part of impact radiation is absorbed in micron subsurface layer, so the following radiation induced structure-phase transformations are highly inhomogeneous: hillocks of LiF-B2O3 and LiBH, LiO2 nanofilm and LiH nanocones are detected on LiF surface. It explains impossibility of annealing LiF-detectors

The changes in the structure of the crystalline graphite are studied during high-energy ball milling (BM) treatment. It was found by XRD analysis the milling time increasing up to 3.5 h leads to the formation of an amorphous phase in the milling process. After 10 h of ball milling treatment, complete amorphization of graphite takes place. It has been shown by high-resolution electron microscopy the individual particles have complex morphology which depends on the BM time. After 1 h of BM carbon materials characterized by an onion-like structure: the individual particles have a spheroidal shape with a size of ~ 10 nm. However, unlike the previous ones after 10 h of ball milling carbon nanomaterials are characterized by a disordered structure, which is typical for amorphous carbon.

The research in this article focuses on the synthesis of Ce donated BaTiO3 needed to make a target for magnetron sputtering. Synthesis is BaTiO3 by sol-gel method with a certain concentration of a modifying additive of Ce. The process of the sol-gel method is considered and the obtained results are characterized. Additional termal treatment of the obtained samples was performed at TOC = 900OC in a muffle furnace in Ar / H2 medium and in a laboratory furnace in air. Physicochemical methods by XRD analysis and Raman spectroscopy were used to characterize the results obtained

The paper proposes a complex assessment of the post-fire state of steel reinforced concrete structures. It covers a combined usage of mechanical tests (core cutting and testing), non-destructive assessment of concrete strength, indirect physical (ultrasonic) methods and direct physical methods (X-ray structural and differential- thermal analyses). The complex analysis of the results enables one to assess the state of the structure and outline means of its strengthening, thus guaranteeing further flawless operation..

The paper presents the effects of the mechanochemical activation of ThO₂-UO₃ and ThO₂-CeO₂ mixtures in air and (for ThO₂-UO₃) in suspension in H₂O or CHCl₃. Planetary ball mill (Pulverisette 5, Fritch) with stainless steel triboreactors and milling balls from the same materials are used. Milling for 5 h of the ThO₂-UO₃ mixture does not affect significantly the crystal structure of the ThO₂ but leads to amorphization of UO₃, sharp decrease of its crystallites size and increase of the ionic character of the U-O bond. Storage of the activated product (2 months at room temperature) or heating (3 h, 165 ^oC) leads to partial relaxation of the UO₃ crystal structure. The X-ray diffraction data does not give proves for formation of ThO₂-UO₃ solid solution.

Formation of solid solution Ce_0.6Th_0.4O₂ accompanied with some amount of amorphisized ThO₂, is established as a result of co-milling at the same conditions of the mixture ThO₂ – CeO₂ with a mole ratio 1. XRD-determined lattice parameter (5.4804(9) Å) and crystallites size (14 nm) of the obtained solid solution are in satisfactory agreement with literature data for the same product obtained via wet chemistry route.

Depleted U₃O₈ was mechanically activated in suspension with tributyl phosphate (TBP), trioctylamine (TOA) and ethylenglycolmonomethylether (EGME) in planetary ball mill with stainless steel vessels and balls. X-ray diffractograms and IR spectra of the activated solid samples were taken. The radioactivities of ²³⁸U and ²³⁴Th in the leaching solutions were determined by α/β liquid scintillation spectrometry. The reduction degree of the oxide, the mean crystallite size of U₃O₈ and U₃O₇ and the leaching of ²³⁸U and ²³⁴Th as a result of the mechanoactivation were determined. Higher degree of ²³⁸U and ²³⁴Th leaching was achieved when mechanoactivation with TBP was performed. No leaching of ²³⁸U daughter product (²³⁴Th) proceeded at mechanoactivation with TOA and EGME. The role of the solvents complexation ability, milling induced increase of crystal defect concentration and UO₂ – ThO₂ solid solution formation is discussed. Further studies have to be made to elucidate the potential of the applied approach as a step in spent nuclear fuel processing.

The present study aims to determine the optimum temperature regime for oxy-nitrocarburizing of AISI D2 steel in order to ensure high mechanical properties of both diffusion and compound zones. The examined samples are quenched and high temperature tempered in advance, thus having a hardness equivalent up to HRc 54-55 before saturation. The vacuum oxy-nitrocarburizing is held at temperatures of 500 ºС, 550 ºС and 590 ºС for 4 hours in a cycling gas flow rate. The proportion of NH₃ and CO₂ gases used is 90:10 volume fractions. The results of the examination are based on the analysis of X-ray diffraction patterns, cross-section microstructures and measurements of micro-hardness values on the surface and in depth of the diffusion zone. The core hardness of the substrate is also measured after the vacuum process for the purpose of establishing a possible hardness decrease after the oxy-nitrocarburizing process. Conclusions have been drawn in relation to the practice.