Advanced Synthesis and Characterization of CdO/CdS/ZnO Heterostructures for Solar Energy Applications

This study introduces an innovative method for synthesizing Cadmium Oxide /Cadmium Sulfide/Zinc Oxide heterostructures (CdO/CdS/ZnO), emphasizing their potential application in solar energy. Utilizing a combination of electrochemical deposition and oxygen annealing, the research provides a thorough analysis of the heterostructures through scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), Raman spectroscopy, and photoluminescence (PL) spectroscopy. The findings reveal a complex surface morphology and a composite structure with significant contributions from hexagonal CdS and cubic CdO phases. The study highlights the uniformity in the distribution of luminescent centers and the crystalline quality of the heterostructures, which is evident from the PL analysis. The redshift observed in the emission peak and the additional peaks in the excitation spectrum indicate intricate optical properties influenced by various factors, including quantum confinement and lattice strain. The research demonstrates these heterostructures' potential in enhancing solar cells' efficiency and applicability in optoelectronic devices. This comprehensive characterization and analysis pave the way for future optimization and application in efficient and sustainable solar energy solutions.

Study of β-Ga2O3 Ceramics Synthesized under Powerful Electron Beam

The synthesis of β-Ga2O3 ceramic was achieved using high-energy electron beams for the first time. The irradiation of gallium oxide powder in a copper crucible using a 1.4 MeV electron beam resulted in a monolithic ceramic structure, eliminating powder particles and imperfections. The synthesized β-Ga2O3 ceramic exhibited a close-to-ideal composition of O/Ga in a 3:2 ratio. X-ray diffraction analysis confirmed a monoclinic structure (space group C2/m) that matched the reference diagram before and after annealing. Photoluminescence spectra revealed multiple luminescence peaks at blue (~2.7 eV) and UV (3.3, 3.4, 3.8 eV) wavelengths for the synthesized ceramic and commercial crystals. Raman spectroscopy confirmed the bonding modes in the synthesized ceramic. The electron beam-assisted method offers a rapid and cost-effective approach for β-Ga2O3 ceramic production without requiring additional equipment or complex manipulations. This method holds promise for fabricating refractory ceramics with high melting points, both doped and undoped.

Burnout dynamic among Ukrainian academic staff during the war

This study examined burnout dynamics among Ukrainian academic staff during the full-scale war. A cross-sectional study was conducted twice: the first wave in July 2022 and the second in January 2023. To assess the burnout syndrome as the final outcome, the self-reported Maslach Burnout Inventory-Human Services adapted for socioeconomic professions by Vodopyanova was used and correlated with different characteristics. The results showed a significant positive trend in emotional exhaustion among Ukrainian academic staff, with females being more sensitive to war-related factors. The results demonstrate that prolonged stressful situations associated with the ongoing war and constant changes in professional conditions lead to significant depersonalization dynamics among academic staff of both sexes. For male academic staff, factors such as age and academic position become less significant for depersonalization. However, university relocation and migration processes were significant factors affecting female academic staff's' perception of effectiveness and accomplishment in their professional activities. The alarming dynamic of burnout levels detected among Ukrainian academic staff urges the national and institutional levels to take prompt actions to enhance the academic staff's mental health in the workplace for preserving not only the quality of higher education, but also human capital in war times for postwar recovery in Ukraine.

Ukrainian universities at the time of war: From occupation to temporary relocation

INTRODUCTION

This paper presents a deep analysis of the impact of the Russian occupation on the activities of Berdyansk State Pedagogical University in Ukraine. This reflection sheds light on numerous challenges faced by the university community under occupation due to the the Russia's full-scale war against Ukraine, particularly emphasizing human rights violations and academic freedom.

METHODS

Utilizing a mixed-method approach, this study employs document analysis, online surveys, and semi-structured interviews.

RESULTS

The findings reveal a profound impact of war and occupation on academic and physical freedom. We share the experiences of staff and students during life under occupation, which are filled with fear of violent actions by the occupiers. Berdyansk State Pedagogical University had to adapt to changing conditions, transitioning to a digital educational platform and decentralizing its structure while concurrently fulfilling its third mission: social service and support of the university community and Berdyansk local community.

DISCUSSION

Our research-reflective piece calls for intervention and further research toward developing effective strategies to protect the rights of staff and students of higher educational institutions in conditions of war and occupation. Conclusions provide a critical view of the catastrophic consequences for academic communities and science if timely measures are not taken.

The Synthesis of porous indium phosphide with nickel oxide crystallites on the surface

In this paper, the technology of synthesis of crystallites and nanocrystallites of nickel oxide on the surface of indium phosphide is described. This technology consists of two stages. In the first stage, porous indium phosphide is formed on the surface of a single crystal of indium phosphide. The formation of such a porous layer provides better adhesion to the surface of the sample. The second stage involves the preparation of the solution that contains nickel ions, application of this solution to the surface of porous indium phosphide, followed by annealing. As a result, NiO/NiC2O4∙2H2O/por-InP/mono-InP structure was formed. Surface morphological parameters were obtained using scanning electron microscopy and EDX-analysis of chemical composition. Chemical analysis confirmed the partial formation of nickel oxide from nickel oxalate layer by thermal annealing. Using scanning electron microscopy, it has been established that the crystallites have a large scatter in diameter, but they may be divided into three characteristic groups: macro-; meso- and nano­crystallites. Such structures may find prospects for application in electrochemical capacitors and lithium-ion batteries. Further research is needed for methodology improvement to obtain structures with predetermined controlled properties.

Training Prospective Nanotechnologists to Select Optimum Solutions for the Nanostructures Synthesis Using the Analytic Hierarchy Process

Nanotechnologists are in great demand and this need is becoming more and more acute every year since nanomaterials have gained widespread acceptance in various industries. The specificity of nanotechnology is determined by a wide variety of existing nanomaterials and technologies for their synthesis. The study suggests an efficient technique for training prospective nanoengineers to make managerial decisions in the synthesis of nanostructures. Moreover, the article demonstrates that using T. Saati's hierarchy analysis method offers the optimum solution for obtaining nanostructures. The analysis is based on the most commonly used synthesis technologies such as chemical etching, photoelectrochemical etching and imprint lithography. The application of T. Saati's method allows prospective nanoengineers to optimize the synthesis of high-quality nanostructures as well as ensure an economic and competitive advantage and reduce the number of errors.

Substantiation of expedience of application of high-temperature utilization of used tires for liquefied methane production

Purpose: The purpose of this investigation is to substantiate by means of numerical simulation the expedience of high-temperature utilization of used tires with subsequent methanation of fuel gases and separation of multicomponent hydrocarbon mixtures to drain the liquefied methane. Design/methodology/approach: The investigation was carried out by means of numerical simulation. In mathematical description of gas processes relations of thermodynamics and heat and mass transfer were used. To determine the coefficients of thermal and physical parameters of working bodies the Peng-Robinson equation of state was used through the computer program REFPROP. The system of equations is represented as the interrelations between the functional elements according to the principle "output from the element A – input into the element B". Its solution was obtained by the method of successive approximations, namely by the Newton-Raphson iteration method. Using this method we have determined the values of temperature, pressure, mass flow rate and mass content of the hydrocarbon gas mixture components in each reference cross-section of the power facility. Findings: As a result of numerical simulation, it is determined that when the multicomponent hydrocarbon mixtures are separated, three flows of energy resources may be obtained: with a high mass content of methane of 91.5% and 83.4%, which may be used as motor fuel, and a gas flow suitable for maintaining the process of waste gasification. However, to remove heat in the condenser of the rectification column, it is necessary to use expensive liquid nitrogen. The cost of methane production may be reduced if the condenser is removed from the rectification column. However, such approach reduces the overall yield of commercial products almost in four times and significantly reduces the methane with the third product (molar percentage of 35%). Research limitations/implications: The investigation was carried out for the material of used tires without a metal frame. Practical implications: The implementation of the technology of high-temperature recycling of used tires gives the opportunity to use the generated synthetic gas to maintain the process of utilization, and gives the opportunity to produce liquefied methane, suitable for storage. Originality/value: The main problem of high-temperature recycling of tires is the emission of toxic gas to the atmosphere. It is proposed to allocate methane energy resource from this gas. For the first time an attempt was made to justify the expedience of the technology of high-temperature utilization of tires for liquefied methane production.