In arid regions, the behavior of solar panels changes significantly compared to the datasheets provided by the manufacturer. Therefore, the objective of this study is to determine the performance of both polycrystalline and monocrystalline solar modules in an arid region characterized by a large potential for solar irradiation and high temperatures. The influence of environmental parameters, such as temperature and dust, on the output power of solar modules with different technologies (monocrystalline and polycrystalline) has been investigated. The Artificial Hummingbirds Algorithm (AHA) has been used to extract parameters for PV modules. As a result, it has been demonstrated that for high solar irradiation, the polycrystalline PV module experiences a smaller decrease in output power than the monocrystalline PV module as the module temperature increases. The percentage drop in output power is approximately 14% for the polycrystalline PV module and nearly 16% for the monocrystalline PV module. However, for low solar irradiation, it is advisable to use monocrystalline modules, as a 21% decrease in power was observed for polycrystalline modules compared to a 9% decrease for monocrystalline modules. Additionally, the monocrystalline PV module was more affected by dust than the polycrystalline PV module under high solar irradiation conditions, while under low incident solar radiation, the polycrystalline PV module was more affected by dust than the monocrystalline PV module. The power drop of the monocrystalline PV module was greater than that of the polycrystalline PV module for high solar radiation (>500 W/m²). Therefore, the advantage of this proposed work is to recommend the use of polycrystalline solar panels in regions characterized by high solar irradiation and high temperatures instead of monocrystalline solar panels, which are more efficient in regions worldwide characterized by low solar irradiation and low temperatures.

A new set of laterally OCH₃-substituted photoactive liquid crystalline analogues, 4-hexyloxy phenyl- imino-4ʹ-(3-methoxyphenyl)-4ʹ’-alkoxybenzoates, were synthesized and investigated for their mesomorphic behavior. The prepared set constitutes five analogues that differ from each other by the terminally attached compact polar group. Characterization of the synthesized derivatives is conducted using differential scanning calorimetry (DSC), polarized optical microscopy (POM), and UV-spectroscopy. Molecular structures were elucidated by elemental analyses, FT-IR and NMR spectroscopy. DSC and POM investigations indicated that all the prepared derivatives are monomorphic possessing the nematic (N) phase, except for the unsubstituted derivative that is nonmesomorphic. On the other side, the photophysical study and the optical spectra measurements confirm the photoactivity of the present compounds under UV/visible irradiation. The measured optical spectra showed impressive enhancement in the optical absorption and reduction in the optical bandgap from 3.63 to 3.0 eV depending on the terminal group. From the study of the DC electric properties, the lowest resistance, 106.5 GΩ at scan rate 0.1 V/s, was observed for the I6_d film with Cl terminal, which decreased to 49.5 GΩ by increasing the scan rate to 0.5 V/s. Moreover, the electrical conductance is decreased from 9.39 pS to 1.35 pS at scan rate 0.1 V/s by changing the terminal group from Cl to F. The enhanced optical absorption and the reduced energy gap make the optimized samples suitable material for solar energy applications.

For the synthesis of an absorber crystalline layer of the solar cell device, the Cu₂ZnSnS₄ (CZTS) absorber is fabricated by using the sol–gel method and the spray deposition technique. The proposed method in this study aims to synthesize stoichiometric CZTS thin films without the sulfurization process and use of a toxic atmosphere. Thin films CZTS were sprayed on the substrates annealed at different temperatures, that are 250, 300 and 350 °C, for solar cell applications. This study highlights the effect of the substrate temperature on the structural, morphological and optical properties of the CZTS deposited films. Therefore, in this study, at the higher substrate temperature, which is 350°C, a semi-optimal band-gap value of E_g = 1.3 eV was obtained. For the all prepared CZTS thin films, the structural and optical properties were discussed in the light of the variations in the observed microstructure at different substrate temperatures. GRAPHICAL ABSTRACT

The microstructure of the commercial alloy AA2195 was investigated on the nanoscale after conducting T8 tempering. This particular thermomechanical treatment of the specimen resulted in the formation of platelet-shapedT1Al2CuLi/θ′Al2Cuprecipitates within the Al matrix. The electrochemically prepared samples were analyzed by scanning transmission electron microscopy and atom probe tomography for chemical mapping. Theθ′platelets, which are less than 2 nm thick, have the stoichiometric composition consistent with the expected Al₂Cu equilibrium composition. Additionally, the Li distribution inside theθ′platelets was found to equal the same value as in the matrix. The equally thinT1platelet deviates from the formula (Al₂CuLi) in its stoichiometry and shows Mg enrichment inside the platelet without any indication of a higher segregation level at the precipitate/matrix interface. The deviation from the (Al₂CuLi) stoichiometry cannot be simply interpreted as a consequence of artifacts when measuring the Cu and Li concentrations inside theT1platelet. The results show rather a strong hint for a true lower Li and Cu contents, hence supporting reasonably the hypothesis that the real chemical composition for the thinT1platelet in the T8 tempering condition differs from the equilibrium composition of the thermodynamic stable bulk phase.

In this study, a homologous series of novel liquid crystalline compounds bearing the bis-azomethine central linkage (–CH=N-N=CH–), namely ((1E,1′E)-hydrazine-1,2-diylidenebis(methanylylidene))bis(4,1-phenylene) dialkanoate (In), was synthesized, and the mesophase and thermal properties were investigated theoretically and experimentally. The molecular structures of the prepared compounds were determined using elemental analysis, NMR, and FT-IR spectroscopy. The mesophase transitions were detected by differential scanning calorimetry (DSC), and the mesophases were identified using polarized optical microscopy (POM). The results indicated that the derivative with the shortest length (I5) was purely nematogenic, while the other homologues (I9 and I15) possessed SmC mesophases. The optimal geometrical structures of the investigated group were derived theoretically. The estimated results demonstrated that all homologues were mesomorphic, and their type depended on the length of the terminal chains. Computations based on density functional theory (DFT) were used to explain the experimental data. The calculated dipole moment, polarizability, thermal energy, and molecular electrostatic potential all showed that it was possible to predict the mesophase type and stability, which varied according to the size of the molecule.