This study focuses on the synthesis of carbon nanowalls (CNWs) and nitrogen-doped CNWs using the RI-PECVD method and their investigation through in situ Raman spectroscopy during voltammetric cycling and potentiostatic charging under both reduction and oxidation potentials. CNWs were synthesized on Ti/SiO₂/Si substrates. Electrochemical experiments were conducted in a three-electrode cell with CNWs as the working electrode, and analytes such as urea, citric acid, and hydrogen peroxide (H 2 O 2 ) were used to study their effects during in situ Raman measurements. The Raman spectra of CNWs and N-doped CNWs were recorded in a voltage range of -1 V to 1 V (vs. Ag/AgCl), revealing no significant shifts in peak positions but showing an increase in the G to 2D peak ratio at higher voltages, indicating strong electron doping. The cyclic voltammetry results demonstrated that nitrogen doping enhances the reductive current of CNWs, with a clear reduction peak observed at -0.7 V across all analytes. The ID/IG peak ratio of N-doped CNWs increased upon analyte addition, suggesting the introduction of defects and restoration of sp2 domains. Furthermore, the position of the G and 2D peaks shifted significantly in response to different analytes. Sharper fluctuations were observed in N-doped CNWs. These results not only provide valuable insights into the electrochemical properties of CNWs but also highlight their potential for electrochemical sensing applications, offering a promising avenue for future research and development in this field. Key words: carbon nanowalls, in situ raman, nitrogen doping, electrochemical reduction.

This study explores the elastic scattering of protons on the 7Li nucleus within the framework of the optical model using the Full-Wave Method (FWM). The approach is based on a high-precision numerical solution of the radial Schrödinger equation, incorporating a microscopic folding potential derived from the M3Y nucleon–nucleon interaction and the nuclear matter density distribution. An imaginary component of the optical potential, parameterized in Woods–Saxon form, is included to simulate absorption effects due to open inelfastic channels. Numerical simulations are implemented in Python using a 6 to 8 order Runge Kutta method to ensure computational accuracy and stability. The resulting phase shifts, scattering ampli tudes, and differential cross sections are calculated for proton energies in the range of 3.0 to 5.5 MeV and compared with experimental data measured at the Van de Graaff accelerator. The analysis reveals system atic overestimations of the differential cross section at both forward and backward angles and emphasizes the necessity of including the imaginary part of the potential and increasing the number of partial waves to improve agreement with observations. The results demonstrate that the Full-Wave Method provides a physically consistent description of the elastic scattering process and offers a solid foundation for further theoretical refinement and experimental validation in light nuclear systems. Key words: light nuclei, elastic scattering, microscopic potential, optical model, FWM, Runge-Kutta method.

Unmanned Aerial Vehicles (UAVs) are increasingly employed for real-time object detection in critical appli cations such as security surveillance, disaster response, and environmental monitoring. However, accurate detection in UAV imagery remains challenging due to small target sizes, cluttered backgrounds, and varying environmental conditions. This study evaluates the performance of YOLOv8n/v8s and YOLOv11n/11s models for human detection in UAV-captured imagery across diverse natural landscapes. To ensure practi cal deployment in resource-constrained environments, the models were implemented on a Raspberry Pi 5 using the OpenVINO framework. Experimental results show that both YOLO series achieve comparable detection accuracy in the range of 80–82%, with YOLOv8n and YOLOv11n demonstrating the highest processing speeds of 10.50 and 11.04 frames per second (FPS), respectively. These findings confirm the feasibility of using lightweight YOLO models for real-time human detection on embedded systems. The re sults highlight the potential of integrating edge AI and UAVs for autonomous, on-site monitoring in remote or complex terrains, offering scalable solutions for intelligent aerial surveillance. Key words: UAV, object detection, accuracy, YOLO models.

Solar activity manifests itself in the form of sunspots on the solar surface and solar flares, which can influence Earth's climatic conditions, including drought in mid-latitude regions. This study examines the impact of solar flares on drought conditions in Northern Kazakhstan and analyzes the relationship between solar activity parameters and drought indices. Twelve solar flares of classes X and M recorded in 2014 were analyzed using multi-wavelength data from SDO/AIA, GOES, and HMI/SOLIS magnetograms. Key physical parameters of the flares were determined, including duration, spatial scale, and magnetic reconnection rate. The reconnection rates ranged from 10⁻⁴ to 10⁻³ and showed an inverse dependence on the GOES classification, consistent with the Petschek reconnection theory. Additionally, correlation links were investigated between solar activity indices (WSN, SSN), atmospheric oscillations (NAO, AO), and drought indices (SPI3, HTC). Significant strong correlations were established: between WSN and NAO (r = 0.63), NAO and SPI3 (r = 0.70), as well as a strong negative correlation between SSN and HTC (r = –0.66), indicating a potential connection between solar activity and drought formation in temperate regions. Key words: solar flares, magnetic reconnection, sunspot activity, drought indices, atmospheric oscillations.

This article presents both theoretical and experimental approaches to the development of biocompatible coatings based on hydroxyapatite modified with titanium dioxide for orthopedic implants made from Ti 13Nb-13Zr titanium alloy. The primary objective was to enhance the adhesion, mechanical strength and antibacterial properties of the coatings by employing a combined technique: micro-arc oxidation followed by gas-thermal spraying. The influence of electrolyte composition and micro-arc oxidation parameters on the coating’s morphology, surface roughness and adhesion strength were systematically investigated. The highest values of hardness and adhesion were achieved using electrolyte containing Na₂SiO₃, NaOH and Na₂S₂O₃ in conjunction with detonation sputtering method. Morphological and elemental analyses confirmed the density, uniform elemental distribution and minimal porosity of these coatings. Mechanical stability was verified through Rockwell B scale and Martens tests. The proposed dual-step surface treat ment strategy offers a promising route for tailoring implant surfaces with multifunctional properties. The obtained results demonstrate that the proposed method can significantly improve the durability and perfor mance of orthopedic implants by producing biocompatible, corrosion-resistant, and mechanically robust coatings. Key words: Biocompatible coatings, micro-arc oxidation, surface modification, mechanical properties, surface roughness, coating adhesion.

This study focuses on the analysis of underground waters from Khaudak and Uchkizil, located in the south ern region of Uzbekistan. These waters are characterized by the presence of various mineral salts, including iodine-containing compounds. The research examines the similarities between these waters, as well as their compositional changes over time under the influence of external environmental factors. Water samples col lected at different intervals were analyzed to monitor variations in composition. The elemental content of the samples was determined using X-ray fluorescence (XRF) analysis, which revealed that iron compounds present in the water tend to precipitate over time. The initial iron content of the water was approximately 0.130%, with subsequent sedimentation resulting in iron-rich deposits containing up to 65% iron. In addi tion, a freshly collected water sample was treated with specific oxidizing agents for iodine and stored for one month. This process led to the formation of a reddish-brown precipitate primarily composed of iron and chlorine, with minor components including iodine and similar elements. The precipitate was found to contain 1.317% iodine, corresponding to 7.66% (21.32 mg/L) of the total iodine content in the Haudak water. Furthermore, exposure of the water to ultraviolet light under open-air conditions resulted in the oxidation and volatilization of iodine, indicating its sensitivity to photochemical degradation. Key words: Khaudak, Uchkizil, iron (III)-chloride, X-ray fluorescence.

This study investigates the corrosion behavior of NZ30K + 0.1 wt.% Ag alloy coated with a silver layer containing copper impurities introduced unintentionally during plasma spraying. X-ray spectral analysis revealed the coating composition as 60.1 wt.% Ag and 39.9 wt.% Cu, which significantly influenced the corrosion performance in Ringer–Locke solution. Intense contact corrosion occurred at coating defects, initiating crevice corrosion and delamination at the transition between cylindrical and flat surfaces. A rapid negative shift in corrosion potential (E<sub>cor</sub>) at 29.9 mV/s was observed—1.67 times faster than in samples with a 1200 nm thick pure silver coating. Subsequently, the shift rate decreased to 0.008 mV/s and stabilized at –1.356 V. Localized corrosion developed into pitting and deep ulcers due to selective anodic dissolution, resembling damage typical of stainless steels in chloride environments. The results indicate that copper contamination in silver coatings on NZ30K-based biodegradable implants is detrimental, as it accelerates local corrosion and hydrogen evolution, potentially contributing to muscle necrosis during bone healing. Keywords: Biodegradable magnesium alloy, NZ30K-Ag composite, corrosion in Ringer-Locke solution, copper-contaminated silver coatings, localized and crevice corrosion.

In recent years, carbon nanomaterials have been studied for their applications in important areas of engi neering and technology due to their unique physical, chemical, and biological properties. The high demand for developing carbon nanomaterials through environmentally friendly and low-cost synthesis strategies has resulted in significant efforts being undertaken worldwide. This study presents the synthesis and char acterization of carbon nanomaterials (CNMs) using the electric arc discharge method under conditions of 75 V and 100 A. A copper substrate was employed to promote material deposition. Structural and morpho logical properties were examined using SEM and Raman spectroscopy. The results revealed the formation of multilayer carbon nanostructures with a high degree of graphitization (up to 88.98%) and particle sizes ranging from 38 to 53.5 nm. Electrophysical measurements demonstrated high dielectric constants and semiconducting behavior over the temperature range of 293–483 K, indicating the material’s potential for electronic applications. The synthesis method offers a scalable, cost-effective, and environmentally friendly approach to producing high-quality carbon nanomaterials. Key words: сarbon nanotubes (CNTs), graphitization, temperature dependence, nanostructured materials, graphitic structures.

In this work, the temperature distribution on a cryosurface operating at low temperatures (in the range from 300 K to 80 K) was thoroughly studied. This type of cryogenic cooling surface is specifically designed for experimental processes that involve the controlled deposition and subsequent cooling of various inorganic compounds. Such processes are essential for conducting detailed investigations into the physicochemical properties, morphology, and structure of these materials under cryogenic conditions. The temperature distribution was analyzed through numerical simulation, which included modeling the cooling process of the cryopanel surface down to cryogenic temperatures using the finite element method. Liquid nitrogen was selected as the working coolant due to its availability, low boiling point, and high efficiency in achieving the required cooling rate. The simulation results revealed the temperature gradient both within the volume and on the surface of the cryopanel. Additionally, the influence of the thermal conductivity of different structural materials–aluminum and stainless steel–on the cooling efficiency was examined. The desired cryosurface temperature range (80–90 K) was successfully reached within 1800 seconds, using a nitrogen flow through a coiled pipe of 6 mm in diameter. Key words: cryosurface, computer modelling, thermal distribution, low temperatures, thermal conductiv ity.

This study investigates the technological parameters of electric arc metallization applied to 30KHGSA steel, focusing on the effects of varying the spraying distance (100–250 mm) and gas pressure (6–9 Pa) on the resulting coating structure and properties. The spraying was performed using an SX-600 electric arc metallizer. Electron microscopy and metallographic analysis revealed that the coatings possess a layered structure consisting of solidified convective metal flows, micro-welded particles, and oxide inclusions. The optimal spraying parameters–150 mm distance and 7 Pa pressure–yielded the maximum coating thickness (729.58–733.62 μm) and the lowest porosity (4.02–4.33%). It was observed that increasing the spraying distance beyond 150 mm leads to reduced coating thickness, while deviations from the optimal gas pres sure result in decreased structural density and homogeneity. Electric arc metallization of 30KHGSA steel under optimal conditions enables the formation of coatings with enhanced wear resistance and mechani cal strength. Specifically, spraying distances over 150 mm and pressures outside the 7–8 Pa range nega tively affect the coating’s density, uniformity, and tribological performance. The identified optimal range (150–200 mm, 7–8 Pa) promotes the development of coatings with low surface roughness, reduced friction coefficient, and improved wear resistance. Key words: arc spraying, steel coatings, microstructure, Vickers hardness, porosity, thickness