Physics and Educational Technology

MILITARY-THEMED PROBLEMS REVEALING THE PHYSICAL FOUNDATIONS OF ELECTRONIC WARFARE OPERATIONS

2025-01-21T16:39:54+02:00

The decade-long Russian aggression against Ukraine is the driver of changes in the life of Ukrainian society in general, and education in particular. Understanding the physical principles of modern weapons not only serves as a means of initial military training for young people but also contributes to the formation of health-preserving competence. Therefore, it is relevant to consider the integration of military topics into the school physics course. Modern warfare is called drone warfare, so learning the physical basics of countering unmanned aerial vehicles, namely electronic warfare (EW) is the key to victory. This paper analyzes the current state of research on the use of military themes in physics lessons and proposes methodological recommendations for introducing EW elements into the educational process. The need for such integration is justified by the relevance of the topic in the context of modern military conflicts and Ukraine's state policy on military-patriotic education of youth. The state standard of basic secondary education and current curricula in physics have been analyzed, and the relevant sections where it is appropriate to consider the issue of EW were determined. An overview of the physical principles underlying the operation of EW means such as radar, radio communication, and electromagnetic interference is presented. A number of problems of practical content on military topics for grades 9-11 are proposed, which can be used in physics lessons to illustrate theoretical material. The problem conditions are compiled using the tactical and technical characteristics of the enemy's EW means, which are systematized by the authors in a corresponding table. Each problem contains a detailed analysis of the physical situation and solution. The authors emphasize that studying the physical foundations of EW not only contributes to deepening students' knowledge of physics but also forms their systematic thinking, develops their ability to analyze real physical processes, and apply the acquired knowledge to solve practical problems.

ON ONE PECULIARITY OF THE PRINCIPLE OF THERMODYNAMIC DUALITY AS A CAUSE OF INDUSTRIAL WASTE

2025-01-21T16:48:41+02:00

The principle of thermodynamic duality in the applied sense allows finding specific mechanisms for minimizing waste at the source of their origin, in the technological process, the proof of which is the purpose of the article. The paper considers the conditions of redistribution of energy and entropy in systems with different levels of non-equilibrium in such a way that allows to increase this non-equilibrium relative to the maximum possible part of raw materials. There is a methodological argument set forth by I. Prigozhin, inherent in this work, that in open thermodynamic systems, entropy may not be able to increase as a result of energy changes in this system, by emission to the supersystem, and thus freeing up the field for that part of the energy that goes to carry out useful work in this system. The second law objectively embraces not only dissipative, but also inverse reparative processes of concentration of energy and matter, for the emergence and development of complex open systems in animate and inanimate nature by borrowing energy from supersystems. Referring to this, an attempt is made to transfer such regularities to the processes of waste generation in production systems. The gradual mutual dependence between thermodynamic processes associated with technologies for the production of finished products and their waste, on the one hand, and dissipative-reparative interactions both inside and outside the system, on the other, is shown. It is shown that in order to create conditions for minimizing waste in the source of their origin – the technological process, it is necessary to ensure the redistribution of entropy between the components of the raw material base in such a way that the negentropy embedded in the finished product increases due to the increase in the entropy of the other material part of the system, and spreads, first of all, to that part of the raw material to which the properties of waste are attributed. This is one of the main elements of scientific novelty in the applied sense of the work. Using examples, a description of the processes characterized by redistributions of entropy and the opposite processes of borrowing energy from the supersystem to the system is provided, which allows to ensure its synergy with respect to waste.

MAIN TRENDS IN THE IMPLEMENTATION OF THE STEM CONCEPT IN THE EDUCATIONAL PROCESS IN PHYSICS

2025-01-21T16:51:22+02:00

The concept that unites science, technology, engineering and mathematics is gaining more and more importance in the context of preparing pupils and students to work in modern high-tech sectors of the economy. The article examines the main trends in the implementation of the STEM (science, technology, engineering, mathematics) concept in the educational process in 2024, in particular in the context of current challenges and opportunities. The article describes the use of artificial intelligence to individualise learning, the introduction of immersive technologies, such as virtual and augmented reality, for a deeper understanding of the material. The article analyses ways to bridge the digital divide and integrate sustainability principles into educational programmes. The advantages of blended learning and a multimodal approach to teaching are discussed. The authors also highlight the main challenges faced by educators in implementing these innovations and offer recommendations for the further development of STEM education. The results of the study emphasize the importance of integrating modern technologies into STEM education. The use of artificial intelligence and virtual reality has shown significant advantages in the educational process, in particular, the possibility of personalizing learning and improving the understanding of complex topics. AI has proven to be useful in adapting learning materials to the individual needs of students, which is especially important in classes with different levels of groups. VR and AR have made learning more immersive by helping students absorb information better through interactive and visual methods. However, the study also revealed existing challenges that stand in the way of the full integration of these technologies. Among them are the high cost of equipment, insufficient technical training of teachers, and a significant digital divide, which makes it difficult for students in small towns and rural areas to access technology. These factors create unequal conditions for students and limit the potential of using the latest technologies.

ELECTRONIC AND OPTICAL PROPERTIES OF QUATERNARY SULFIDE Tl2HgSnS4

2025-01-21T16:54:21+02:00

Among the sequaternary chalcogenides, thallium, mercury, tinsulfide Tl2HgSnS4 is of particular interest. This sulfide is a unique quaternary compound that exists in the quasi-ternary system Tl2S-HgS-SnS2. Its non-centrosymmetric tetragonal structure (I4-2m) suggests some promising use of Tl2HgSnS4 in nonlinear optics. Mercury and tin atoms have four sulfur atoms in their immediate surroundings. In the Tl2HgSnS4 structure, thallium atoms occupy 4c Wyckoff positions, mercury atoms occupy 2b, tin atoms fill 2a, and sulfur atoms occupy 8i positions. In the Tl2HgSnS4 structure, Tl atoms are characterized by a tetragonal-antiprismatic surrounding by S atoms. In addition, thallium, mercury, and tin atoms form trigonal prisms in the immediate surroundings of sulfur atoms in the Tl2HgSnS4structure. It is known that knowledge of electronic and optical properties, as well as the features of the nature of chemical bonding in solids are of great importance, since it allows to understand and predict the physicochemical properties of the compounds. In this work, we have conducted a combined theoretical and experimental study of the electronic structure and optical properties of the Tl2HgSnS4 crystal. In particular, we have investigated the X-ray photoelectron (XP) spectra of core level and valence electrons (VB), as well as the X-ray emission (XE) S Kβ1,3 band (valence S p states) for the Tl2HgSnS4 crystal grown by the Bridgman-Stockbarger method. Particularly, in this study, we have developed an effective method for experimental studying the electronic structure of crystals by X-ray photoelectron spectroscopy (XPS), which allows eliminating the presence of hydrocarbon impurities adsorbed on the crystal surface. To estimate the band gap energy of the Tl2HgSnS4 crystal, the optical absorption edge at room temperature was investigated. To verify the experimental results, ab initio calculations of the optical absorption edge of the Tl2HgSnS4 compound were performed.

OPTICAL AND NONLINEAR OPTICAL PROPERTIES GLASSES OF THE GeS2-As2S3-Er2S3 SYSTEM

2025-01-22T07:59:26+02:00

Chalcogenide glasses doped with rare earth ions have attracted considerable attention of researchers due to their widespread use in optoelectronics, in particular in lasers operating in the mid-infrared range. At the same time, it is possible to change the parameters of such lasers by changing the chemical composition of the source material. One of the most promising impurities in chalcogenide glasses is Erbium, which is due to its ability to efficiently emit quanta of electromagnetic waves at the standard telecommunication wavelength of 1540 nm. It is practically impossible to predict the properties of glasses using only the theory of the processes of absorption and emission of light, so the study of the effect of Er3+ impurities on the optical properties of chalcogenide glasses lies in the experimental plane. The scope of applications of the studied materials in optoelectronics is related to the width of the band gap. To estimate the optical band gap, a study of the spectral distribution of the absorption coefficient in the region of the edge of the intrinsic absorption band was conducted. The width of the forbidden optical band gap is estimated. It was established that as the molar fraction of As2S3 in the studied glasses of the GeS2 – As2S3 – Er2S3 system increases, the absorption edge shifts to the longwavelength region, which reflects the reduction of the optical band gap. The decrease in the band gap with an increase in the molar fraction of As2S3 is due to the fact that As2S3 has a smaller band gap than glassy germanium disulfide. The study of the generation of the second and third harmonics was conducted. The achieved parameters of nonlinear optical effects of the third order make it possible to predict the wide application of the studied glasses as materials for nonlinear optical conversion of IR laser beams, which is of crucial importance for IR lidar systems (light rangefinders). The coexistence of the photoinduced generation of the second harmonic and the generation of the third harmonic (obtained without laser stimulation) opens up the possibility of using the studied glasses in optoelectronic devices that operate simultaneously on doubled and tripled frequency signals.

TEMPERATURE DEPENDENCES OF THE AVERAGED GROUP VELOCITIES OF ACOUSTIC PHONONS IN FLAT NANOFILMS OF LEAD DIIODIDE

2025-01-22T08:08:23+02:00

Unique properties of quasi-two-dimensional structures based on the layered semiconductor lead diiodide make them attractive for the creation of advanced nanoelectronic devices. Currently, a number of technologies have been developed for obtaining quasi-two-dimensional structures based on lead diiodide, and a large body of experimental research results on their properties has been accumulated. However, there are relatively few studies dedicated to the theoretical description of the phenomena and processes occurring in such structures. In particular, the role of acoustic phonons in shaping the characteristic properties of these structures remains largely unexplored. The purpose of this work was to investigate theoretically the temperature dependencies of the average group velocities of acoustic phonons in lead diiodide nanofilms of varying thickness. Using the methods of classical dynamics of atoms in a crystalline lattice within the approximation of an elastic continuum, the frequencies and group velocities of acoustic phonons in a hexagonal quasi-two-dimensional crystalline structure – lead diiodide nanofilm (polytype 2H-PbI2) – were calculated. The calculations were carried out using previously established analytical dependencies of the dispersion laws for these quantities for each mode of acoustic phonons with all possible polarizations: shear, flexural, and dilatational. Further averaging of the group velocities was performed using methods of statistical physics with the distribution function of phonon states by frequencies in the 2D-structure and the Bose-Einstein distribution. Thus, for the first time, a study was conducted on the temperature dependencies of the average phonon velocities for each of the mentioned polarizations for different sets of values of the parameter N – the number of layered 2H-PbI2 packets in the nanofilm, which determines its thickness. It has been shown that by changing the temperature and thickness of the nanofilm, the propagation speed of phonons for each polarization can be significantly altered. Particularly, by reducing the thickness of the lead diiodide nanofilm, the group velocity of shear-polarized phonons can be reduced by several times, and the velocities of SA- and AS-polarized phonons can be reduced by tens of times. The temperature changes in phonon propagation speeds are nonlinear: in the low-temperature range (below 150, 90, and 50 K for SA-, AS-, and shear-polarized phonons, respectively), their values increase rapidly with rising temperature, whereas at higher temperatures, they are almost independent of it. Results of this study can be used to create thermoelectric devices based on 2H-PbI2 nanofilms with the desired properties, since the speed of heat flows, determined by the speed of propagation of acoustic phonons, is regulated by the appropriate thickness selection.

OPTICAL PROPERTIES OF Dy-DOPED AgGaGe3Se8 CRYSTALLITES

2025-01-22T08:11:39+02:00

This study analyzes the impact of doping AgGaGe3Se8 crystals with Dy atoms on their optical properties. Phase control and chemical composition determination were conducted on the studied crystals. It was established that the crystal exhibits a single-phase morphology, although all samples show visible dark spots, lighter, and darker areas caused by the nonuniform surface roughness resulting from cutting and grinding. The content of the components is in good agreement with the initial composition of the synthesized sample, confirming the qualitative assessment of the elemental composition and homogeneity of the samples within the selected scanning area. To estimate the bandgap width, the spectral distribution of the absorption coefficient in the fundamental absorption edge region was investigated. It was found that the studied crystal is an indirect-gap semiconductor. The estimated bandgap width in the temperature range of 100-300 K is 2.23 eV at T=300 K and 2.41 eV at T=100 K. It was determined that the introduction of the rare-earth element (Dy) into AgGaGe3Se8 contributes to the increase in the bandgap width. It was established that the operating range of the studied crystal can be considered as the range from 0.6 μm to 15-16 μm. The temperature coefficient of the bandgap width change was determined to be -9*10-4 eV/K, which correlates with the value for AgGaGe3Se8 (-8.5*10-4 eV/K). The obtained results allow us to conclude about a single mechanism of thermal change in the bandgap width for all studied samples, since the coefficients describing this change have the same order. The Urbach parameters and the electron-phonon interaction constant were calculated. An analysis of the obtained data indicates an increase in the Urbach energy with increasing temperature of the samples in the range from 100 to 300 K, which can be explained by an increase in the concentration of charged defects, which at low temperatures were neutral but undergo thermal ionization when heated. It was established that doping leads to an increase in the electronphonon interaction constant. Such an increase is probably due to the presence of dysprosium (Dy) ions at the silver (Ag) sites and an increase in the concentration of vacancies in the silver sublattice. Both of these factors, as charged impurities, affect the electron-phonon interaction, enhancing it.

INFLUENCE OF HYDROSTATIC PRESSURE ON THE ELECTRONIC STRUCTURE OF THE CuAlTe2 CRYSTAL

2025-01-22T08:15:09+02:00

In this paper, for the first time, a theoretical study of the structural and physical properties of the CuAlTe2 crystal under the influence of external hydrostatic pressures was carried out. For this, a complex of computer calculations was carried out, which included the calculation of the crystal structure and properties of the material under study. The crystal structure was determined using the Broyden-Fletcher-Goldfarb-Schenno method, which was used to obtain optimized lattice parameters and atomic coordinates. The study of the electronic properties of the crystal and their transformation under the action of hydrostatic pressure was carried out by modeling from the first principles. For this purpose, calculations of the band-energy structure of the crystal E(k) were carried out within the framework of the density functional theory (DFT). The exchange-correlation interaction was described using the generalized gradient approximation. The main attention is paid to the study of changes in crystallographic parameters under pressure, which allows us to understand the peculiarities of the behavior of this material under the influence of high pressure. Hydrostatic pressures in the range of 0–5 GPa were used in the work. The results show that under the influence of hydrostatic pressure there is a gradual decrease in the volume of the unit cell, which is in good agreement with theoretical predictions and is described by the Murnaghan equation of state. On the basis of this equation, the bulk modulus of elasticity B and its first pressure derivative B', which characterize the crystal's resistance to deformations, are determined. It was investigated that the application of pressure causes a significant tetrahedral deformation of the CuAlTe2 crystal lattice, which can affect its physical properties, in particular, the electronic structure. Importantly, an increase in pressure leads to an increase in the band gap Eg, which can be useful for potential applications of the material in semiconductor technology. Calculations showed that the change in the value of Eg with increasing pressure corresponds to a quadratic dependence, which allows us to accurately describe the behavior of the gap width in the range of applied pressures. The obtained results may be useful for the further application of CuAlTe2 in high-tech devices, where materials with the ability to adjust the band gap under the influence of external conditions are needed.

THEORETICAL AND METHODOLOGICAL FOUNDATIONS OF RADIATION EDUCATION IN HIGHER EDUCATION INSTITUTIONS

2025-01-22T09:02:21+02:00

The article examines the relevance of radiation education in the context of the growing nuclear threat due to military aggression and the growing use of nuclear energy for peaceful purposes. The author emphasises the need to increase the level of radiation literacy of the population, especially in higher education institutions, in order to prepare specialists for possible radiation threats. The analysis of international studies confirms the importance of developing radiation education, which includes scientific understanding of the nature of radiation, risk assessment and practical skills in prevention and control. Most current research focuses on the development of teaching methods and curricula. It was found that there is a lack of research on the development of integrated approaches to radiation education, especially in the context of post-accident situations. The present study analyses the existing research and emphasises the need to develop integrated programmes that include both formal and non-formal teaching methods using modern digital technologies. The purpose of the article is to substantiate the theoretical and methodological foundations of radiation education in higher education institutions. It has been substantiated and proved that the main didactic principles of this education are scientific, accessible, systematic, continuity, problematic, consciousness and activity. The potential of interdisciplinary and transdisciplinary approaches to radiation education is revealed as optimisation approaches to radiation education, which contribute to the qualitative substantiation of the content of training, selection of effective forms, methods and means. Methodological approaches that can be adapted to specific learning objectives and audience are proposed. The choice of the optimal method requires taking into account such factors as the level of students' training, the availability of material and technical resources, and the specifics of the curriculum. Further research in radiation education is seen in the systematic substantiation of the content of academic disciplines.

PROBLEMS OF MODELING A CRITICAL THERMONUCLEAR PROCESSES

2025-01-22T09:05:18+02:00

A brief analysis of the problem of modeling critical thermonuclear processes is presented. Attention was focused on two types of processes. First is determined by the generation of thermonuclear reactions in stationary regime. This problem is main for the creation thermonuclear reaction and has Earth value. Second is lifetime of stationary phase. This problem is main for lifetime of stars and have Universe value. The first refers to the problem of the threshold for the occurrence of thermonuclear reactions. Here, Lawson's criterion is analyzed and its significance in the problem of thermonuclear reactor construction is shown. Deuterium-deuteriun and deuterium-tritium reactions are analysed. Various mechanisms of modeling the generation and realization of these reactions, including magnetic fields, are discussed. The well-founded concepts of muon catalysis and its role in the generation of thermonuclear reactions are also given. The issue of the influence of the shape and symmetry of deuterium and tritium nuclei on the threshold for the generation of thermonuclear reactions and its contribution to the Lawson criterion is analyzed. The second part refers to astrophysics. The Schönberg- Chandrasekhar criterion is formulated. The Schönberg -Chandrasekhar theory of the residence time on the main sequence of the Hertzsprung-Ressel diagram, which is general for all stars of the main sequence of the diagram, is analyzed. The Schönberg-Chandrasekhar limit and its dependence on the nature of stars are analyzed: isothermal, polytropic, etc. The problems of homogeneity and heterogeneity of stars and its influence on the Schönberg-Chandrasekhar limit are observed too. Its role in the development of modern astrophysics is shown. Prospects for the use of the Schoenberg-Chandrasekhar limit for nuclei other than hydrogen and helium are also discussed.

MODELING THE INFLUENCE OF CdS NANOWIRES ON THE PROPERTIES OF A SECOND-GENERATION PHOTOVOLTAIC CONVERTER

2025-01-22T09:08:10+02:00

The article investigates the influence of CdS nanowires on the characteristics of second-generation thin-film photovoltaic converters based on the ITO/SnO₂/nw-CdS/CdTe heterostructure. Modeling was performed using the SCAPS software, enabling the identification of optimal structural parameters to achieve maximum efficiency. The study highlights the use of a CdS nanowire layer as a buffer (window) layer, which provides enhanced optical properties and improves the fill factor and energy conversion efficiency. The modeling revealed that the optimal thickness of the CdTe absorber layer is 3 μm, the CdS buffer layer is 120 nm, and the SnO₂ conductive layer is 40 nm. For these parameters, the photovoltaic converter efficiency reaches 13.33%, with a fill factor of 77.39%. The application of CdS nanowires reduces carrier recombination at the layer interface, decreases light losses due to reflection, and enhances charge carrier transport. As a result, the spectral response of quantum efficiency improves, and the impact of defects on device performance diminishes. The effect of interface defect density at the nw-CdS/CdTe boundary was also studied. Results show that increasing the defect density beyond 1012 cm-2 significantly reduces the open-circuit voltage, short-circuit current, and thus the overall efficiency. It was established that interface defect states critically affect device parameters, emphasizing the importance of their control to enhance performance. The findings demonstrate the advantages of integrating CdS nanowires into thin-film solar cells based on the CdS/ CdTe heterojunction. This approach allows for achieving high efficiency and operational stability of solar cells, making them promising for large-scale production.