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To reduce greenhouse gas emissions and the environmental impact of fossil fuels, Morocco has decided to increase the use of renewable energy resources. The intermittent nature of renewable energy resources causes instability in the power grid. Energy storage is the appropriate solution to this problem. Compressed air energy storage is a technology that stores energy in the form of high-pressure compressed air in above ground tanks or underground caverns. Large-scale storage of compressed air energy requires the storage of large volumes in salt caverns or aquifers. The aim of this paper is to find out the benefits of integrating underground compressed air energy storage technology. A case study in Morocco is used to estimate the levelized cost of energy plus storage (LCOES). The annual capacity factor for solar and wind power plants and the potential of underground caverns in Morocco were analyzed. The results illustrate that for a system with 100 MW capacity installed in the Casablanca region, the combination of an adiabatic compressed air energy storage system (ACAES) with a wind turbine installation offers the lowest electricity price per kWh, with average LCOES of 0.04 $/kWh. [ABSTRACT FROM AUTHOR]

This study presents a pioneering methodology for implementing the maximum power point tracking (MPPT) controller, based on fuzzy logic. Through a comprehensive performance analysis, we evaluate its effectiveness compared to the widely used perturb and observe (P&O) algorithm, which is a common MPPT technique. The main objective of our proposed MPPT approach is to improve the performance of a photovoltaic (PV) system. To evaluate the performance of the proposed MPPT controller and compare it with the P&O algorithm, we designed and simulated both controllers using MATLAB/Simulink. We also implemented a prototype of the controllers using an Arduino Mega board, and evaluated their performance under real operating conditions. The experimental results unequivocally confirm that the fuzzy logic-based MPPT controller outperforms the P&O algorithm in terms of performance, speed and accuracy. The fuzzy logic controller offers greater accuracy in tracking the maximum power point under various environmental circumstances, including variations in solar irradiation and connected load. Overall, this work contributes to the development of efficient and reliable MPPT controllers for PV systems, and provides a comparison of the performances of two popular MPPT techniques. Future research could explore other MPPT techniques and evaluate their performance using similar experimental setups. [ABSTRACT FROM AUTHOR]

By using the DFT approach within the generalized gradient approximation (GGA) adopted in the Wien2k code, the effects of pressure on the structural, electrical and optical characteristics of XZnF3 (X= Na, K and Rb) halide perovskites have been investigated. In the present paper, the unit cell structures of XZnF3 (X= Na, K and Rb) have been optimized. Within the present approximation, the analysis showed indirect bandgaps of those compounds. At 0GPa, the density of states (DOS) besides band structures predicted the bandgaps of (2.80, 3.84 and 4.22eV) connected to (NaZnF3, KZnF3 and RbZnF3), respectively. These indirect bandgaps increase from (0 to 20GPa) with hydrostatic pressure. Regarding the optical properties, the imaginary part ε2(ω) of the dielectric function, the absorption α(ω), the reflectivity R(ω) and the refractive index n(ω) are determined. The light absorption at the surface begins at critical points corresponding to the threshold energy, their values of (5.00, 5.20 and 5.30eV at 0GPa) and (5.90, 6.30 and 6.50eV at 20GPa) related to NaZnF3, KZnF3 and RbZnF3, respectively. The pressure induced in XZnF3 (X= Na, K and Rb) reduces absorption intensity to a remarkable extent, both in the visible and ultraviolet range and the intensity of the reflectivity spectra decreases with increasing pressure. When there is no induced pressure, optical conductivity starts out with lower photon energies and increases as pressure builds up, reaching greater photon energies at pressures of up to 20GPa. The mechanical stability of the material studied is verified using the Born stability criteria, the values obtained for the elastic constants verify the stability conditions of XZnF3(X= Na, K and Rb), improving with applied pressure 0 up to 20GPa. NaZnF3 and KZnF3 have slightly higher ductility than RbZnF3 at 0GPa, and KZnF3 has a slightly higher ductility than NaZnF3 at 0GPa, and higher than RbZnF3 at 20GPa. Also, the mechanical stability is verified using the Born stability criteria, where the elastic constants verify the stability conditions. The Cauchy pressure value of XZnF3 (X= Na, K and Rb) perovskite under all the pressures studied is positive, indicating that the ductile nature of perovskite improves and increases with increasing pressure. [ABSTRACT FROM AUTHOR]

Introduction: Fish quality is traditionally controlled by chemical and microbiological analysis. The non-destructive control presents an enormous professional interest thanks to the technical contribution and precision of the analysis to which it leads. This paper presents the results obtained from a characterisation of fish thaw-ing process by the ultrasonic technique, with monitoring thermal processing from frozen to defrosted states., Material and Methods: The study was carried out on fish type red drum and salmon cut into fillets of 15 mm thickness. After being frozen at -20°C, the sample is enclosed in a plexiglas vessel with parallel walls at the ambient temperature 30°C and excited in perpendicular incidence at 0.5 MHz by an ultrasonic pulser-receiver Sofranel 5052PR. the technique of measurement consists to study the signals reflected by fish during its thawing, the specific techniques of signal processing are implemented to deduce informations characterizing the state of fish and its thawing process by examining the evolution of the position echoes reflected by the sample and the viscoelastic parameters of fish during its thawing., Results: The obtained results show a relationship between the thermal state of fish and its acoustic properties, which allowed to deduce the optimal time of the first thawing in order to restrict the growth of microbial flora. For salmon, the results show a decrease of 36% of the time of the second thawing and an increase of 10.88% of the phase velocity, with a decrease of 65.5% of the peak-to-peak voltage of the signal reflected, thus a decrease of the acoustic impedance., Conclusions: This study shows an optimal time and an evolution rate of thawing specific to each type offish and a correlation between the acoustic behavior of fish and its thermal state which approves that this technique of ultrasonic monitoring can substitute the control using the destructive chemical analysis in order to monitor the thawing process and to know whether a fish has suffered an accidental thawing.