6 research outputs found
The effect of a stroboscopy visual training with senaptec glasses on reaction speed and ball control technique among goalkeepers for the U13 years old
No full textThe research aims to identify the impact of visual exercises on some basic skills of football players, to solve one of the problems facing the development of the game of football, which is the speed of reaction and the skill of holding the ball, where a group of goalkeepers were formed for the age group of 11-12 years to participate in this study. They were assigned vision-based Synaptic glasses to expose players to unique visual training. These glasses feature time control for the displayed images, causing disruptive clear vision for short periods during training the performance of the guards participating in different exercises before and after the training period was measured using stroboscope glasses. The data were also analyzed and performance results compared to determine the impact of stroboscopic visual training on goalkeeper performance. As the researchers used the experimental approach by designing experimental groups using the pre- and post-test, and the research sample was tested in a deliberate way from youth football players during the 2022/2023 sports season, where appropriate statistical means were used, which is the statistical fact, and the results resulted in significant differences between the pre- and post-tests in favor of the post-test,,, 
Temperature and Pressure-Induced Phase Transitions in Cu2ZnSnS4 and Cu2ZnGeS4: Thermodynamic Analysis and Structural Transformations
No full textThis study focuses on investigating the phase transitions in two materials, Cu2ZnSnS4 (CZTS) and Cu2ZnGeS4 (CZGS), which are important for understanding their structural and functional properties. The temperature and pressure-induced tetragonal-orthorhombic phase transitions in these materials are analyzed using density functional theory (DFT) and the quasi-harmonic Debye model. The research aims to examine the changes in the material’s structure and the associated thermodynamic properties during these phase transitions. The results reveal that both compounds exhibit a negative value of δHmix, indicating the release of energy during the mixing process, which suggests an exothermic nature. The DFT calculations at zero temperature and pressure demonstrate that the stannite structure represents the ground state configuration of the Cu2ZnSnS4 system (with xGe = 0%), compared to the wurtzite-stannite structure. The calculations also show that the difference in enthalpies of formation (δH) between the stannite and wurtzite-stannite phases for CZTS is estimated to be 8.884 meV per atom. Regarding Cu2ZnGeS4, the wurtzite-stannite structure is found to be the most stable, closely followed by the stannite structure, with enthalpies of formation of −4.833 eV·atom−1 and −4.804 eV·atom−1, respectively. Notably, there are no definitive reports on enthalpy studies for the Cu2ZnGeS4 system in the existing literature. Understanding the behavior of these materials under different conditions can contribute to the development of improved performance and stability of devices based on CZTS and CZGS
Unveiling the structural, electronic, optical, mechanical, and thermodynamic properties of Mg
No full textThis study investigates the physical properties of the novel mixed metal oxide Mg3ZnO4, emphasizing its potential in optoelectronic manufacturing. We provide a comprehensive analysis of its structural, optoelectronic, mechanical, and thermodynamic characteristics, focusing on the ternary compound, which crystallizes in a rocksalt phase similar to the mineral Caswellsilverite. Using advanced density functional theory (DFT) and the Full-Potential Linearized Augmented Plane Wave (FP-LAPW) method within the WIEN2k package, we predict the material’s properties in detail. Our structural analysis confirms the stability of Mg3ZnO4 in the cubic Pm3̅m space group, revealing key crystallographic parameters. The electronic structure calculations indicate a well-defined energy band gap, confirming its semiconducting nature and suitability for optoelectronic applications. Optical properties, including the dielectric function, absorption, and reflection spectra, demonstrate significant light interaction, highlighting the material’s potential for UV photodetectors and photovoltaic solar cells. The investigation of elastic properties provides critical insights into the mechanical strength and durability of Mg3ZnO4, further supporting its viability for demanding applications. Additionally, our thermodynamic analysis reveals the material’s behavior under varying environmental conditions, reinforcing its potential in high-performance optoelectronic devices. These findings establish Mg3ZnO4 as a promising candidate for advanced thin-film solar cells and pave the way for future experimental and theoretical studies to explore its unique properties for innovative technological applications
First principles investigation of optoelectronic properties of ZnXP2 (X = Si, Ge) lattice matched with silicon for tandem solar cells applications using the mBJ exchange potential
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