Eurasian Physical Technical Journal

DEVELOPMENT OF LOW-TEMPERATURE CELL FOR IR FOURIER-SPECTROSCOPY OF HYDROCARBON MATERIALS

2025-07-03T11:50:45+05:00

This work introduces a technology for Fourier-Transform InfraRed spectroscopy of hydrocarbon materials at low temperatures and atmospheric pressure. This device allows to study optical properties of various substances at temperature range of 77 – 300 K without need of a vacuum and to obtain new fundamental data since there is insufficient research in this area. Described new techniques and methods are working with Fourier-Transform InfraRed spectrometer, diffuse reflection attachment and two Dewar vessels using for cooling with liquid nitrogen inside cryogenic capillary system and blowing with gaseous nitrogen to create InfraRed inactive environment. It makes this new technique a valuable method for obtaining fundamentally new data useful for various energy and infrastructure spheres along with education field as a theoretical information.

PREDICTION OF CORROSION RESISTANCE OF MAGNALIAS

2025-07-01T11:52:00+05:00

In the presented work the factors influencing the strength and corrosion rate in seawater of magnalium aluminum-magnesium alloy were considered. It was shown that in unsaturated solid alpha solutions the main form of magnesium in the aluminium structure was the electronic compound Mg₂Al₄ entering the rhombic subsystem of aluminium cells. The calculation showed that the more aluminium cells contain Mg₂Al₄ group as a rhombic subsystem, the higher the strength of these alloys. The mechanism of destruction by halogen ions of pure aluminium cells and aluminium cells containing the Mg₂Al₄ group was determined by the PM3 method. Destruction of both types of cells occurred by the same scenario, through the detachment by halogen ions of the central atom in the upper edge of cells bordering. It was shown that in seawater the corrosion rate of aluminium cells containing Mg₂Al₄ group was higher than the corrosion rate of pure aluminium cells. A mathematical model has been developed that allows calculating the change in the corrosion rate of magnesium alloys with low magnesium mass fraction (up to 3.5 % magnesium inclusive) in seawater. The model allowed to take into account the change of influence of the mass fraction of the main alloying elements (Mg, Cr, Mn, Zn, Ti, Cu) on the corrosion rate. Change of corrosion rate in seawater of three aluminium-magnesium alloys variants was calculated using this model. These aluminium alloy variants include a magnesium content of 2.6 mass % with higher levels of the alloying elements Cr and Mn.

INVESTIGATION OF THE STRESS-STRAIN STATE DURING NEW COMBINED DEFORMATION TECHNOLOGY

2025-07-01T11:51:43+05:00

This paper presents the results of finite element modeling of a novel technology of combined deformation by radial-shear broaching and traditional drawing. Using DEFORM program, the parameters of stress-strain state and deformation forces were studied. A range of models with varying initial diameters of the workpiece, single and total compressions, and different temperatures of heating the workpiece were considered. It was revealed that the optimal conditions occurred at 30-25-20 scheme at a temperature of 900°C. However, this scheme can be recommended when the strength of the deforming equipment is sufficient. In other cases, it is necessary to select a scheme that allows for deformation without exceeding the limiting loads.

THERMAL INFRARED OBJECT DETECTION WITH YOLO MODELS

2025-07-01T11:51:26+05:00

Object detection is a fundamental task in computer vision and remote sensing, aimed at recognizing and categorizing different types of objects within images. Unmanned aerial vehicle - based thermal infrared remote sensing provides crucial multi-scenario images and videos, serving as key data sources in public applications. However, object detection in these images remains challenging due to complex scene information, lower resolution compared to visible-spectrum videos, and a shortage of publicly available labeled datasets and trained models. This article introduces a Unmanned aerial vehicle - based thermal infrared object detection framework for analyzing images and videos in public applications and evaluates the performance of YOLOv8n/v8s, YOLOv11n/v11s, and YOLOv12n/v12s models in extracting features from ground-based thermal infrared images and videos captured by Forward-Looking Infrared cameras, as well as from unmanned aerial vehicle - recorded thermal infrared videos taken from various angles. The YOLOv8n/v8s, YOLOv11n/v11s, and the latest YOLOv12n/v12s models were deployed on a Raspberry Pi 5 using the OpenVINO framework. The successful deployment of these models, including the most recent version, demonstrates their feasibility for unmanned aerial vehicle-based thermal infrared object detection. The results show that YOLOv8 and YOLOv11 achieved high accuracy and recall rates of 93% and 92%, respectively, while the YOLOv12 model demonstrated good precision but comparatively lower performance in accuracy and recall, suggesting the possibility for further improvement.

THE EFFECT OF THE INTERNAL HEAVY ATOM ON SINGLET OXYGEN GENERATION IN THE PRESENCE OF PLASMONIC NANOPARTICLES

2025-07-04T11:51:46+05:00

The heavy atom effect on singlet oxygen generation in the plasmon field of silver nanoparticles was investigated. The dyes rhodamine 123 and dibromrhodamine 123 in polyvinyl butyral films were used as sensibilisers. The dye films were deposited by spin-coating onto silver island films synthesised on the quartz surface. The results showed that the presence of bromine atom in the dye molecules increased the singlet oxygen generation efficiency. The calculated Stern-Follmer constants demonstrate the enhancement of molecular oxygen quenching of triplet states of dibromorhodamine 123 dye molecules in the presence of Ag nanoparticles.

MULTIPULSE LUMINESCENCE DETECTION OF THE SPATIAL DISTRIBUTION OF REAGENTS AND THE DIFFUSION FLOW OF O2 MOLECULES INTO POLYMER LAYER

2025-07-04T11:51:30+05:00

The problem of monitoring processes involving molecular oxygen in porous media still remains relevant due to the development of technologies based on the use of nanostructured systems. It is becoming important to study the characteristics of the reactions in nano cells with different morphologies and connectivity. The specifics of the localization and transport of reagents, which determine the yield of the product during transformations, provide valuable information for analyzing the process and optimizing its flow conditions. In this regard, it is necessary to improve the methodology for measuring photoinduced signals of oxygen-containing systems in non-stationary modes with time resolution to determine the current concentrations of reactant molecules. The kinetics of oxidative photoreactions in a colored polymer film was studied with multiple pulse activation of the system taking into account the layer-by-layer diffusion replenishment of the concentration of oxygen consumed in the reaction from the atmosphere. The process of chemical binding of oxygen molecules with immobilized anthracene molecules in an oxygen-permeable polymer film of polyvinyl butyral containing molecules of an organic dye (erythrosine) as a photosensitizer was recorded. A mathematical model is proposed that describes the kinetics of oxygen-dependent photoreactions in the film and the formation of luminescent response signals during its multi-pulse laser activation taking into account the diffusion replenishment of oxygen molecules in the intervals between the activating pulses. Based on a comparative analysis of the experimental and calculated luminescence signals, the nature of the non-uniform spatial distribution of the photosensitizer and the oxidized reagent in the polymer film is assessed.

PROPERTIES OF Ag/TiO2 AND Ag/SiO2 NANOPARTICLES AND THEIR EFFECT ON THE PHOTOCATALYTIC PROPERTIES OF A SEMICONDUCTOR NANOCOMPOSITE

2025-07-04T11:51:13+05:00

The optical properties and the electric field distribution around silver nanoparticles coated with TiO₂ or SiO₂ shell have been studied. It is demonstrated that the presence of a shell around a plasmonic nanoparticle leads to a bathochromic shift in the maximum of its absorption band. The maximum electric field intensity around metal nanoparticles is radially concentrated, predominantly near the surface of the nanoparticles. The quantum efficiency, representing the ratio of emitted photons to absorbed photons, is nearly 50% higher for Ag/TiO₂ nanoparticles compared to Ag/SiO₂. In the presence of Ag/TiO₂ and Ag/SiO₂ core/shell nanoparticles the photocatalytic activity of the TiO₂/rGO nanocomposite increases by 2.7 and 1.7 times, respectively. These changes are associated with improved charge transport properties of TiO₂/rGO and possible hot electron injection from the nanoparticles into the semiconductor.

A COMPREHENSIVE PHENOMENOLOGICAL, SEMI-MICROSCOPIC, AND CRC ANALYSIS OF 15N ELASTIC SCATTERING FROM 13C AND 19F NUCLEI

2025-07-04T11:50:56+05:00

In the present study, the angular distributions obtained at beam energies E_lab = 30.0, 32.0 and 45.0 MeV for the ¹⁵N+¹³С reaction and E_lab= 23.0, 26.0 and 29.0 MeV for the ¹⁵N+¹⁹F system were subjected to a comprehensive reanalysis using the optical model, the double folding model, and the coupled reaction channel (CRC) method. The main objective of the study was to establish the optimal optical potential through phenomenological and semi-microscopic analysis. Through careful calculations, the acceptable parameters of the potentials and their energy dependencies were derived for both nuclear systems. Notably, the angular distributions were well reproduced, indicating the effectiveness of the theoretical models used. In back angle scattering analysis, the CRC has very good agreement with the experimental values. As a result of the analysis, spectroscopic amplitudes were extracted for the ¹⁵N → ¹³C + d and ¹⁹F → ¹⁵N + α configurations at different energies of the incident ¹⁵N ions. The obtained results of spectroscopic amplitudes were subsequently compared with previously reported values, facilitating an assessment of the consistency and accuracy of the present work.

SPECTROPHOTOMETRIC STUDIES OF ASTEROIDS I: REFLECTANCE SPECTRA

2025-07-01T11:51:07+05:00

The paper presents the results of the analysis of the reflectivity spectra of asteroids based on observations obtained on 2024-02-22, 2023-11-03, 2023-11-04 and 2023-11-21 at the Assy-Turgen Observatory (77°.87114 E, 43°.225527 N, 2658 meters above sea level, international observatory code 217) using a long-slit spectrograph based on volume-phase holographic gratings (VPHG) installed at the prime focus of the AZT-20 telescope with an aperture of 1.5 meters. The observations were carried out in the low-resolution mode (R=600) in the range of 3500-7500Å using a grating of 360 lines per mm, a dispersion of 4.25Å per pixel, in the first binning in the EMCCD mode with a gain of 5 and an exposure time of 10 seconds, the slit width of 9 arc seconds. The spectrum of asteroids was measured using the differential method: by comparing the fluxes from the object and a standard star. Solar analog stars (G-class stars) were used as standards. Processing and calculation of reflectance spectra, alongside the determination of taxonomic classification according to the Tholen and SMASSII systems, based on spectral morphology and selected spectral characteristics, were conducted for a sample of 19 asteroids, primarily consisting of Main Belt members (14). A comparison was made with the spectra of asteroids based on INASAN observations in 2013–2017 and the reflectivity spectra of asteroids obtained from Gaia (DR 3) observations, and their taxonomic types were determined without taking into account the albedo of the asteroids.

DEMONSTRATING NONLINEAR OSCILLATIONS OF CHARGED PARTICLE BY THE HOMOTOPY PERTURBATION METHOD

2025-07-01T11:50:50+05:00

This document describes explicitly the nonlinear equation handling the oscillation ‎of charged particles affected by electrical field using the Homotopy Perturbation ‎Method. This method success to construct a significant approximate solution. Our ‎analysis has resulted in the development of an initial set of four equations that ‎govern the oscillatory of charged particles. Following this, we have visually ‎depicted these equations and satisfied a deep clear interpretations vision of the ‎investigated outcomes‎. Our ‎analysis has resulted in the development of an initial set of four equations that ‎govern the oscillatory of charged particles. Following this, we have visually ‎depicted these equations and satisfied a deep clear interpretations vision of the ‎investigated outcomes‎.

STUDY OF BRIGHTNESS VARIATIONS OF IRAS 07080+0605 FROM THE ASAS SN DATA

2025-07-01T11:50:33+05:00

This paper presents the findings of an analysis of the light curve of the star IRAS07080+0605, a member of the FS CMa class. The analysis was conducted using data from the ASAS-SN survey, collected between 2014 and 2025. The year-by-year analysis of the ASAS-SN time series in the g filter reveals that the system's period changes over time, and the shape of the phase curve varies during individual intervals. The asymmetry observed in the phase curves suggests potential orbital changes, possibly related to the system's dynamics, including variations in the separation between the components. Additionally, we describe changes in the luminosity amplitude of IRAS07080+0605, which may reflect alterations in the star's physical state, such as pulsations in its outer layers or interactions with its environment.

ENHANCED EFFICIENCY OF DYE-SENSITIZED SOLAR CELLS USING ZNO NANOPARTICLE DOPING CU FROM PINEAPPLE PEEL EXTRACT WITH MODIFIED NATURAL DYE SOLUTION

2025-07-03T11:52:12+05:00

Photoanodes and dye solutions are indispensable in the stability and efficiency of Dye-Sensitized Solar Cells’ performance. In this study, the photoanode uses a ZnO sample doped with Cu, made using a green synthesis technique with bio-reduction from pineapple skin extract. Meanwhile, using the maceration method, the dye solution is made from mulberry fruit extract and moringa leaves. For Dye-Sensitized Solar Cells applications, ZnO photoanodes doped with 1%, 3%, 5%, and 10% Cu were each depleted on ITO glass and immersed in the dye solution for one day. The results were then tested for electrical conductivity and performance in Dye-Sensitized Solar Cells. Adding Cu doping concentration to the ZnO photoanode can affect the performance of the Dye-Sensitized Solar Cell. In this work, the ZnO sample doped with 5% Cu as a photoanode showed the highest efficiency at 1.67% with an electron lifetime of 12 ms, compared to the photoanode without Cu doping or with Cu doping at concentrations of 1%, 3%, and 10%. Thus, Cu-doped ZnO nanoparticles and dye solutions from natural materials can be further developed for Dye-Sensitized Solar Cells applications.

STUDY OF OPTIMAL ENERGY PARAMETERS OF ELECTRO-HYDROPULSE TREATMENT FOR EFFICIENT EXTRACTION OF VALUABLE COMPONENTS FROM ORGANIC WASTE

2025-07-03T11:51:54+05:00

The article considers some aspects of solving the urgent problem related to waste processing, in particular, renewable biowaste from the food industry. Development and implementation of modern technologies for processing and recycling various organic waste will reduce dependence on fossil energy sources, achieve carbon neutrality and maintain environmental safety. The object of the study is organic waste of the agro-industrial complex in the form of bone mass. The possibilities of efficient extraction of the valuable component using electro-hydro-pulse processing were experimentally studied. A description of the basic diagram of the electro-hydro-pulse installation and testing methods for different processing modes are given. Optimum values of electrical parameters are determined, allowing to increase the degree of extraction of valuable components from organic raw materials while reducing the processing time.

STUDY OF THERMOPHYSICAL DYNAMICS IN BIOFUEL DROPLET ATOMIZATION AND COMBUSTION

2025-07-03T11:51:37+05:00

The article presents a study of computer modeling of thermophysical processes occurring during atomization and turbulent combustion of biofuel (biodiesel) droplets in the combustion chamber of a direct injection engine. For this purpose, a complex computer model was developed, including mathematical, spatial, and numerical submodels for calculating a complex turbulent reacting flow. Using the developed model, computational experiments were performed to investigate the thermal and aerodynamic properties of the reacting fuel-air mixture of biodiesel, focusing on the effects of temperature and pressure variations in the combustion chamber. The research results made it possible to obtain a visualization of the reacting flow with temperature and concentration characteristics of harmful emissions during biodiesel combustion. The numerical data obtained during the modeling were compared with the results for traditional diesel fuel.

GENERALIZATION OF THE LOCAL APPROACH APPLICATION TO THE ASSESSMENT OF TRANSFER PROCESSES IN HEAT POWER EQUIPMENT

2025-07-03T11:51:20+05:00

In order to develop measures to improve the thermal efficiency of working surfaces and the coolant supply system, it is necessary to examine and analyze the results of comprehensive studies of transfer processes under complex conditions of interaction of external (increased turbulence) and internal (separation) turbulent effects typical for heat power equipment. The aim of the work is to develop methods for assessing transfer processes in such equipment based on local control of thermophysical parameters in characteristic zones of the working environment. The object of the study is heat exchange surfaces of power, chemical and electronic equipment, as well as coolant supply systems. The research method is physical modeling of turbulent effects of various natures and processes of heat, momentum and mass transfer using hot-wire, electro-calorimetric methods, and heat and mass analogy methods. The article considers the generalization of the local approach application on examples of assessing the influence of increased turbulence, local closed separations and unsteady flows on transfer processes in the flow part of heat power equipment for various purposes. A local approach to the development of an effective coolant supply system for the technology of final drying of plant waste fragments is also considered. The use of a local approach, which allows recording thermophysical parameters in any characteristic zone of the working space, provides the ability to control the most thermally stressed areas. These results are the basis for developing measures to increase the thermal efficiency of working surfaces.

AERODYNAMIC IMPROVEMENT OF A TWO-BLADE MAGNUS WIND TURBINE: NUMERICAL AND EXPERIMENTAL ANALYSIS OF AERODYNAMICS AND PRESSURE DISTRIBUTION

2025-07-03T11:51:02+05:00

Improving wind power plant efficiency is crucial due to the increasing demand for renewable energy. This study analyzes the aerodynamic characteristics of a wind power plant equipped with two combined blades that integrate fixed blades and rotating cylinders. The object of the study is a wind power plant model designed to optimize airflow direction and enhance lift. The methodology involves numerical modeling using the Ansys Fluent software package, as well as experimental testing under laboratory conditions. The main results show that as when the air-flow velocity increases from 3 to 12 m/s, and thrust force rises from 0.5 N to 3.85 N. Comparative analysis of the minimum and maximum pressure on the blade surfaces demonstrates a strong correlation between increasing rotational speed and elevated pressure differentials: p_max rises from approximately 0.4 Pa to 0.7 Pa, while p_min increases from about 0.15 Pa to 0.4 Pa. The thrust coefficient decreases from 1.45 to 1.05 as the Reynolds number (Re) increases, indicating improved aerodynamic characteristics during the transition to turbulent flow. A comparative analysis of numerical and experimental data reveals a deviation of no more than 5%, confirming the model’s reliability and the soundness of the research methodology. The conclusions indicate that employing combined blades can enhance the aerodynamic efficiency of a wind power plant by 8–10% compared with traditional designs. This improvement may foster the development of more efficient and stable wind energy systems, particularly in regions with low to medium wind potential.