Université de M'sila
  • M’Sila, MʼSila, Algeria
Recent publications
This investigation presented presents the drying characteristics, and aimed to predict the drying kinetics of tomato slices (Lycopersicon esculentum MILL.) using convection and microwave methods. Hot air drying was carried out in a ventilated oven at 50, 60, 80, and 100°C temperatures and microwave drying was performed in domestic microwave using 300, 500, 800, and 900 W powers. Twenty‐two mathematical models were undertaken to predict the drying kinetics and the best model was chosen based on the highest R2 values and the lowest root mean square error (RMSE) and χ2 values. Drying kinetics, drying rate variation, diffusivity and energy consumption of both methods were evaluated. Fernando and Amarasinghe model and Sledz model were the best models for convective and microwave drying processes, respectively. Effective moisture diffusivity varied from 0.28 × 10−9 to 2.81 × 10−9 and from 1.32 × 10−9 to 21.52 × 10−9, while the activation energy was 27.64 kJ/mol and 5.71 W/g for convective and microwave drying processes, respectively. The energy consumption increases with increasing temperature or power, the reverse was observed for energy efficiency. Microwave drying process has the advantage of drying time reduction, low‐energy consumption, and high‐drying efficiency at a moderate high‐power level (900 W). Hence, it is recommended to apply this innovative process for drying tomato slices. In this study by using more than 20 models, for the first time, we demonstrated that microwave‐assisted drying of tomato slices was more effective than forced convection drying. It revealed a shorter drying time, high‐drying rates, and high diffusivity with low‐energy consumption.
Nanoparticles (NPs) synthesized by the co-precipitation technique show many attractive properties such as small particle size, high crystallinity, high average pore diameter and high specific surface area. However, numerous reports show that some characteristics of the Ni-doped ZnO (NZO) NPs remain controversial such as optical bandgap (Eg), surface morphology and defect level. In this study, pure ZnO and NZO NPs at different Ni contents (x) were successfully prepared using the co-precipitation method. Phase analysis confirms the hexagonal wurtzite crystallinity of the samples. XRD peak shows that the Ni may substituted ZnO structure as the peaks shift toward higher angles with increasing x. Meanwhile, the formation of NiO secondary phases was significant at 12.50% Ni content. Densely packed spherical shaped structures with nanoparticle agglomeration are observed at low x, while some nanorod shaped structures appear at higher x. The stretching vibrations of the Zn–O bond are observed in the NZO NPs. The absorption edge shifts to higher wavelengths with the increase in x. This study provides consistent results in the phase analysis, morphology and structural parameters. The decrease in Eg agrees with the photoluminescence measurements. The emission spectra confirm the presence of interstitial zinc and singly ionized oxygen vacancies.
Two-dimentionnal Atlas SILVACO-TCAD® device simulator is used to simulate the performances of dual-junction (2J) GaInP/GaAs tandem solar cell under AM1.5G illumination spectrum. The structure of GaInP/GaAs tandem solar cell consists of the combination of two single-junctions based on GaInP top-cell and GaAs bottom-cell. The performance of GaInP/GaAs tandem solar cell is studied using ZnO intermediate layer as a transparent conducting oxide (TCO) between the bottom and top cells to connect them in serial structure. An undoped ZnO front layer is used as an anti-reflective (AR) layer in front side of GaInP top-cell to enhance the conversion efficiency. Without ZnO front layer, a conversion efficiency of 25.29% has been achieved with 0.95 μm base layer thickness of GaInP top-cell and a current-matching density for both cells was Jsc = 11.30 mA/cm2. Optimization resulted in record efficiency of 30.82% in GaInP/GaAs tandem solar cell by introducing ZnO front layer with 0.7 μm base layer thickness of GaInP top-cell with a current-matching density of 13.66 mA/cm² and an open circuit voltage of 2.51 V. The GaInP/GaAs tandem solar cell in current study exhibit an improvement in conversion efficiency using anti-reflective ZnO front layer. This results are a promising step to fabricate an efficient III‐V multi-junctions solar cells.
The stereometric and fractal concepts are crucial tools to analyze, to verify, to report 3-D microtexture of thin film surfaces on the nanometer scale, and thereby to generate useful topographic characteristics for better understanding and steering them toward further improvements and rational use in modern applications. At first, the present work aimed to prepare hematite α-Fe2 O3 thin films with (0, 2, 4, 6 and 8 wt%) of Cu doping by using the air pneumatic spray method. Subsequently, the obtained pure α-Fe2 O3 and Cu-doped α-Fe2 O3 thin films were characterized by XRD device, which determines their polycrystalline nature with the rhombohedral hematite structure. Analysis by UV-vis absorption showed that the transmittance of the thin films is extinct in the wavelength from approximately 500 nm to 800 nm, revealing that the films have good optical absorbance in the visible region. The obtained bandgap values varied between 2.23 and 2.21 eV. At second stage, the stereometric and fractal analysis are applied on 3-D image data of pure α- Fe2 O3 and Cu-doped α- Fe2 O3 thin films, which in prior generated using AFM device. Accordingly, the obtained statistical parameters such as surface roughness, density distribution of peaks, and depths, etc. were used to understand the influence of Cu doping on the 3D microtexture of pure α- Fe2 O3 and Cu-doped α- Fe2 O3 thin film surfaces. This article is protected by copyright. All rights reserved.
The electronic, magnetic, elastic, and thermoelectric properties of CoFeYGe (Y = Ti, Cr) quaternary Heusler compounds are studied using DFT simulations. Our calculations show that both CoFeYGe (Y = Ti, Cr) alloys have a Type‐I atomic configuration. CoFeCrGe and CoFeTiGe compounds with band gaps of 0.640 eV and 0.489 eV, respectively, were found to display half‐metallic behavior in the minority spin channels. The total magnetic moment of CoFeCrGe was 3.00 μB, while CoFeTiGe's was 1.00 μB. CoFeTiGe and CoFeCrGe are both mechanically stable in the Y‐Type‐I structure. The surface of E is entirely distorted, demonstrating substantial anisotropy for two compounds. They have a higher anisotropic Young's modulus in the (XY), (XZ), and (YZ) planes. At 900 K, ZT is 0.31706 (0.45308) for CoFeTiGe (CoFeCrGe), corresponding to a carrier concentration of n0 = 20.4581 × 1021 cm−3 (64.5856 × 1021) cm−3. Two ways exist to enhance ZT values of CoFeTiGe and CoFeCrGe to 0.4032 and 0.64149, respectively: A charge carrier concentration of 17.392 × 1021 cm−3 for CoFeTiGe and 59.503 × 1021 cm−3 for CoFeCrGe is obtained. The second similar result is obtained by raising the chemical potential of CoFeTiGe and CoFeCrGe by 0.068 and 0.980 Ryd, respectively. To our knowledge, CoFeCrGe and CoFeTiGe exhibit exceptional spintronic and thermoelectric properties. Two ways exist to enhance ZT values of CoFeTiGe and CoFeCrGe to 0.4032 and 0.64149, respectively: A charge carrier concentration of 17.392 × 1021 cm−3 for CoFeTiGe and 59.503 × 1021 cm−3 for CoFeCrGe is obtained. The second similar result is obtained by raising the chemical potential of CoFeTiGe and CoFeCrGe by 0.068 and 0.980 Ryd, respectively. To our knowledge, CoFeCrGe and CoFeTiGe exhibit exceptional spintronic and thermoelectric properties.
One of the essential phases in delivering a precise simulation of the fuel cell system behavior is estimating the model parameters of the fuel cell system. A novel identification approach based on the bald eagle search algorithm (BES) is suggested in this study to reliably extract the best PEM fuel cell characteristics (PEMFC). BES is a modern metaheuristic algorithm with outstanding performance in various applications. Furthermore, this method delivers an accurate result because of its unique convergence mechanism. The PEMFC identification is an optimization problem to minimize the sum square error (SSE) of the model and measurements. The unknown parameters are used as decision variables. The BES is a new powerful optimizer that offers outstanding accuracy and efficiency. To assess the effectiveness of the suggested method, two different types of PEMFCs were used: BCS 500 W and NedStack PS6. To approve the excellence of BES, a comparison was performed to those achieved using various optimizers, including gravitational search algorithm (GSA), grey wolf optimizer (GWO), differential evolution (DE), sine cosine algorithm (SCA), RSA encryption algorithm, and arithmetic optimization algorithm (AOA). The achieved results approve the advantage of BES in comparison with other algorithms. The SSE for NedStack PS6 employing the proposed method has been reduced to 2.07974 and 0.01136 for the BCS 500 W type. An accurate fitting for the measured datasets with the least deviation between the estimated and the experimental one.
Roots and rhizomes of Asparagus stipularis Forssk were separately extracted using supercritical CO2 extraction (SCCO2) and pressurized liquid extraction (PLE) and their Total Phenols Content and antioxidant potential was investigated. The results indicated that the roots and rhizomes are a potential source of natural antioxidants. The PLE method gave better extraction yields than SFE and its fractions present the highest antioxidant activity. Direct evaluation of antioxidant capacity using the QUENCHER procedure showed that also the solid residue of the plant material remaining after the SCCO2 and PLE may be of interest as a source of valuable phytochemicals.
In this article, an ultra‐wideband (UWB) topology optimized frequency selective surface (FSS) is introduced as a reflecting layer, to maximize the gain and overall performances of an UWB monopole antenna. The single Rogers RO4350B‐based FSS layer is synthesized using an automated system, based on an interface bridged between CST Microwave studio and Matlab, and optimized using a binary genetic algorithm. First, the FSS unit cell foot print needs to be as small as possible, while covering a wider frequency range, and to achieve these performances, the proposed genetic algorithm synthesizing system achieved an FSS unit cell with only 0.1 λ × 0.1 λ at the lower‐end frequency, covering a bandwidth of 2.9–14.5 GHz. Polarization independence is achieved also, due to the four‐folded symmetry imposed on the FSS unit cell. The proposed antenna is designed on a Rogers RO4350B substrate, and backed at a distance of 18.74 mm by an FSS structure. The fabricated prototype shows a bandwidth of 3.1–13.9 GHz, and an excellent maximum peak gain of 9.7 dBi, with an improvement of 3.41 dBi cross the UWB spectrum (from 3.7 to 7.11 dBi), and in good agreement with the simulation results, which made the proposed design a promising candidate for UWB applications requiring high gain, such as ground‐penetrating radar, and microwave radiology imaging (MRI) systems.
This work reports, for the first time, the kinetics of α-cordierite (Mg2Al4Si5O18) formation from Al2O3, SiO2, and MgO nano-oxide powders. Isothermal and non-isothermal kinetic analysis was performed by Differential Thermal Analysis (DTA) and thermodilatometric analysis (TDA). The thermal measurements were performed at high heating rates (20–70 °C/min) for DTA and low rates (3–9 °C/min) for TDA. Phase transformations leading to the formation of α-cordierite were characterized by x-ray diffraction (XRD). The Kissinger, Boswell, and Ozawa methods were used to calculate the activation energy. The Avrami parameter (n) and dimensionality of crystal growth (m) were calculated using the Augis–Bennett and Matusita equations, respectively. Analysis of samples heated in the DTA equipment or the dilatometer confirmed that the reaction of MgO, Al2O3, and SiO2 led to the formation of enstatite, cristobalite, and metastable μ-cordierite. The later transformed to stable α-cordierite. The activation energy calculated by both isothermal and non-isothermal treatments is 633 and 667 kJ/mol, respectively, for DTA; and is 646 and 544 kJ/mol, respectively, for DTA. The growth morphology parameters n and m, obtained from isothermal and non-isothermal DTA treatments, are both close to 2 indicating that bulk nucleation with constant number of nuclei is dominant in α-cordierite crystallization followed by two-dimensional growth of α-cordierite crystals with plate-like morphology controlled by interface reaction. While those obtained from isothermal and non-isothermal TDA treatments, are both about 1.5 indicating that bulk nucleation is dominant in α-cordierite crystallization followed by three-dimensional growth of α-cordierite crystals with polyhedron-like morphology controlled by diffusion from a constant number of nuclei. A low coefficient of thermal expansion (CTE) of 0.9 × 10⁻⁶/°C was measured, in the range 200–1350 °C, for a sample sintered at 1400 °C‏ for 2 h.
Solar energy is an infinite, unpredictable and enduring energy source among all other incompatible energy options. This work simulates the feasibility of installing a photovoltaic (PV) system isolated with batteries in a typical residential center in M'sila, Algeria, where the study is carried out to assess solar radiation and evaluate the technical and economic aspects of the PV system to supply domestic electrical energy needs. The program has been implemented by PVsyst6. The daily electricity consumption is about 12.6 kWh/day. On an annual basis, the energy that is injected into the grid is 4615 kWh. The average performance ratio (PR) of the Si-poly PV system is operated at 62.9% in the simulated study for the planned location. The maximum electrical energy produced was from June to August, when it reached 354.4 kWh of July. The losses recorded in the study were principally due to temperature of photovoltaic field, which was 12.14%.
Lithium-ion batteries play an essential role in sustainable power systems as energy storage systems. They are employed for electrical power storage and balancing power in multisources power systems. However, due to the degradation phenomena, these systems are more exposed to parametric variation. For this reason, the identification of the battery parameters remains crucial to enhance the power system performance and extend the battery lifespan. A robust parameter identification strategy based on the bald eagle search algorithm (BES) is proposed in this research work. This article proposed a robust estimation approach that accurately estimates the battery parameters based on the BES optimizer. The proposed approach has been evaluated for two distinct batteries to confirm its superiority. A comparison with recent optimization methods has been performed to validate the performance of the proposed strategy. These algorithms include marine predator algorithm, COOT algorithm, artificial eco-system optimizer, and other previous algorithms. The obtained results affirmed the reliability of the proposed BES-based strategy to estimate the battery equivalent circuit variables with superior accuracy compared with other methods. It provided the smallest fitness function value for the first battery with 7.06 × 10−4 and an excellent SD value of 1.877 × 10−8. The proposed strategy achieved 100% efficiency in terms of optimization efficiency. The second battery has been tested with ArtUban and New European Driving Cycle (NEDC) profiles to confirm the performance of BES. The results confirm the superior performance for the two cases. The BES provides the smallest fitness values (0.0860 for ArtUrban and 0.1222 for NEDC) and lower identification total error (2.294 for ArtUrban and 2.6737 for NEDC).
In this manuscript, we present a generalized formulation of the deformed Dirac equation, by considering the effect of a noncommutative space-time on the improved quadratic exponential-type potential plus Eckart potential and Yukawa-like tensor interaction (IQEPEP-YTi, in short). Using the Bopp’s shift method arising from the Weyl-Moyal star product, we obtain modified DDE equations for spin and p-spin symmetries. The new values of energy that we got appeared sensitive to the quantum numbers (j,k,s,l,m,…), the mixed potential depths (a,b,c,A,B), the range of the potential , and noncommutativity parameters . The three physical phenomena that are automatically generated as a result of the topological properties of noncommutativity are the perturbative spin-orbit coupling, the magnetic induction, and the third corresponds to the rotational proper phenomena. We show that the corrections to the spectrum energy are smaller than the main energy in the usual cases of the Dirac equation. The three physical phenomena that are automatically generated as a result of the topological properties of noncommutativity are the perturbative spin-orbit coupling, the magnetic induction, and the third corresponds to the rotational proper phenomena. We show that the corrections to the spectrum energy are smaller than the main energy in the usual cases of quantum field theory. In the new symmetries of extended relativistic quantum mechanics ERQM, it is not possible to get the exact analytical solutions for k=0 and, only the approximate solutions are available. Some special cases of our solution are investigated by choosing appropriate parameters in the IQEPEP-YTi model.
Urban vulnerabilities must be studied and assessed to make cities more resilient to floods. This study aimed to assess the urban vulnerability of El Bayadh city, located in the west of Algeria, to floods and to identify flood-prone areas. Using the Hierarchical Multi-criteria Analysis (HMA) method, a set of criteria was proposed such as population density, housing typology, type of equipment, and road network to measure the overall fragility of the study area. The Geographic Information System (GIS) was used to translate the obtained results and develop the global vulnerability map. The most important results were: 5.6% of the study area had an extreme vulnerability, 7.97% high vulnerability, 8.5% medium vulnerability, and 77.87% low vulnerability. The results of this study can be used as a tool to assist local authorities during decision-making regarding flood danger assessment.
Employing the FP-LAPW method, structural, electronic, optical, thermodynamical, and thermoelectric parameters of Bi2Al4Se8 compound are systematically investigated. The calculated structural parameters such as, in-plane lattice constant, out-of-plane lattice parameter, and axial ratio (a, c, c/a), as well as, atomic positions are found to be consistent with the experimental findings. Using the mBJ-LDA approximation, band structure results reveal that Bi2Al4Se8 is an indirect band gap semiconductor (Eg = 2.94 eV). The energy gap is mostly explained by the p-p interaction between bismuth and selenium atoms. Absorption peak of ε2xx(ω) and ε2zz(ω) at 3.66 eV and 3.77 eV respectively has been determined. The dispersive part ε1(ω) of the dielectric functions shows a significant anisotropy. In addition, the maximum values of the nxx(ω),nzz(ω) refractive indices are found to be 3.01, 2.42 at 3.11 eV, 3.04 eV, respectively. Consequently, Bi2Al4Se8 can be utilized as a key component for optoelectronic devices since it exhibits a high absorption intensity. At room temperature, Grüneisen parameter of Bi2Al4Se8 compound is found to be 1.045 corresponding to a calculated lattice thermal conductivity of 1.40 W/mK. The positive S value for the entire temperature range confirms that the compound is a p-type. As a consequence, the figure of merit ZT is found to increase as the temperature is increased for both types of carriers. It attain maximum values of around 0.76 and 0.73 for n and p-type doping at −6.448 × 10¹⁸ cm³ and 4.635 × 10¹⁸ cm³, respectively. The values of Sxx Seebeck coefficient are found to be greater than those found in the Szz. Interestingly, Sxx exceeds 300 μ V/K at T = 150 K. The high value of Sxx shows that transport along xx-axis is dominant. However, (σzz) is 79% of (σxx) at high temperatures. The electronic thermal conductivity at high temperatures (kexx) is larger. We found the value of (kezz) to be 65% of that of (kexx). At 900 K, ZT is 0.65, equivalent to a carrier concentration of n0 = 1.21891 × 10²¹ cm⁻³. The greater value of ZT is obviously 0.74 and this value is obtained by lowering the charge carrier concentration to n0 = 0.36582 × 10²¹ cm⁻³.
Analyses based on first-principles simulations have revealed new details about the mechanical and thermodynamic characteristics of NaBH4 and NaAlH4 complex hydrides in α, β and γ phases. Using the quasi-harmonic Debye model, thermal parameters like the Debye temperature, the heat capacity, and the thermal expansion coefficient of NaXH4 (X = B, Al) complex hydrides are calculated in α, β and γ phases at different pressures and temperatures for the first time. Single-crystal elastic constants may be derived from the stress-strain relationship calculations. Although NaBH4 has a stronger compressibility modulus than NaAlH4, the distance dB-H is shorter than dAl-H, which may be explained by the presence of the covalent bond in BH4 and AlH4 in NaXH4 (X = B, Al). The melting points of NaXH4 (X = B, Al) may be used to estimate the decomposition temperatures of hydrogen. β-NaBH4 has a higher melting point than α-NaAlH4. Thus, the decomposition temperature of NaAlH4 at which hydrogen is released from a fuel cell is expected to be lower than that of NaBH4. β-NaBH4 has a more directed bonding tendency than α-NaAlH4 does. Except for the phase γ-NaAlH4, the NaXH4 (X = B, Al) compounds are ductile. NaBH4 deforms more than NaAlH4 in uniaxial deformation, yet both are centrally strong solids. Our PBE calculations result in the linear compressibility and orientation-dependent Young's modulus. Tetragonal β-NaBH4 and α-NaAlH4 structures have an isotropic bulk modulus but an anisotropic Young's modulus.
The aim of this study is to shed more light on the formation of mullite and the kinetics of mullitization from sol-gel synthesized precursors. Tetraethylorthosilicate (TEOS) and aluminum nitrate nonahydrate (ANN) were used, as a source of silica and alumina, respectively, for the synthesis of homogenous mullite precursor powder. The mullitization process was characterized by thermogravimetry (TG), differential thermal analysis (DTA), thermodilatometric analysis (TDA), and x-ray powder diffraction (XRD) techniques. It was found that mullite started to crystalize at temperatures of 1050, 1200, and 1241 °C as determined by XRD, DTA, and TDA, respectively‏. Mullite crystallization kinetics was thoroughly investigated under isothermal and non-isothermal conditions using DTA. The activation energy for mullite formation was calculated, for different crystallization fractions, following the Freidman, Kissinger, Boswell, and Ozawa methods. The average values were found to be 1282.92, 1324.30, 1336.93, and 1283.09 kJ/mol, respectively. The kinetic parameters and the crystallization mechanism were determined and the results were compared with those available in the literature. The Sestak Berggren SB(m,n) model was found to be the most suitable for the determination of mullite crystallization mechanism. The calculated average values of the Gibbs free energy (ΔG#), enthalpy (ΔH#), and entropy (ΔS#) for mullite formation, at different heating rates, were 433.98 kJ/mol, 1294.20 kJ/mol, and 566.23 J/mol.K, respectively.
h i g h l i g h t s A cost-effective energy management strategy for the microgrid based PEM fuel cells is proposed. Implementation of marine predator algorithm to minimize the operating costs. The performance has been investigated under various operating conditions. Available online xxx Keywords: DC microgrid Energy management strategy Operating cost Marine predator algorithm a b s t r a c t This paper provides a cost-effective energy management method for the microgrid's standalone and on-grid operational modes. The considered microgrid based on Green-to-Green systems such as a photovoltaic array (PV), wind turbine (WT) as renewable generators , hydrogen fuel cell (FC) system, microturbine (MT), and battery storage system. The suggested technique is based on the marine predator algorithm (MPA) that and created for a scheduling horizon of one day. The main objective of this paper is to reduce operating costs while satisfying the demand power. To approve the performance of the suggested management strategy, the simulation results are compared with other recent optimization algorithms. These algorithms include particle swarm optimization (PSO), salp swarm algorithm (SSA), and coot optimization algorithm (COOT). To approve the performance of the proposed EMS, the system will be evaluated for three cases: free renewable generation, restricted generation mode, and unlimited main grid power mode. For the first case, the proposed EMS reduces the operating costs by 0.8732%. For case 2, the economic benefits Please cite this article as: Ferahtia S et al., Optimal heuristic economic management strategy for microgrids based PEM fuel cells, International Journal of Hydrogen Energy, https://doi.org/10.1016/j.ijhydene.2022.02.231 have been raised by 1.0815% and by 0% for the last case because of the reduced problem complexity.
Activity against HM1: IMSS strain of E. histolytica has been carried out through the PHASE program (Schrodinger-USA). The best pharmacophore model generated consisted of five features DHHHR-4: three Hydrophobic (H), one aromatic ring (R), and one H-bond donor (D). Field-Based 3D-QSAR model studies were applied on a series (60 compounds) of pyrazoline derivatives. The best prediction was obtained with a gaussian field combined steric, electrostatic, hydrophobic, hydrogen bond donor, and acceptor fields (r ² =0.837, q ² = 0.766). The contour maps resulting from the best field-based QSAR model were exploited to discover the structural properties related to the biological activity of this series of analogous molecules. Structure-based docking studies were performed to elucidate the intermolecular interaction between pyrazoline derivatives and the 5ZFE receptor. Active ligands 35 and 36 have the highest activity and the best docking scores. The insilico ADMET screening of these active ligands was also performed and the values of all the properties are within the recommended values. The information obtained from pharmacophore, 3D QSAR model, molecular docking, and ADMET screening can be used to discover pyrazoline derivatives that increase antiamoebic activity.
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1,447 members
Rokbi Mansour
  • Department of Mechanical Engineering
Mimeche Fateh
  • Agricultural Sciences
Mohamed Slamani
  • Mechanical Engineering
H. Baaziz
  • Department of Physics
Chouder Aissa
  • Electrical Engineering
BP 166 , 28000, M’Sila, MʼSila, Algeria
Head of institution
Kamel Baddari
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