University Mustapha Stambouli of Mascara
Recent publications
One of the most recent challenges that manufacturers confront is to respond on time to the variety of customers’ demands for different products. The Assembly line is the main element responsible for assembling products in manufacturing systems, and it requires good management to avoid several problems that could lead to production failures. The mixed-model assembly line balancing problem type-I (MiMALBP-I) occurs in the step of designing a new assembly line in which different models of one product are assembled in an intermixed sequence; it aims to optimize the number of workstations for a fixed known cycle time. In this paper, the authors propose a Hybrid Reactive Greedy Randomized Adaptive Search Procedure (HRGRASP) to solve this problem. The performance of the proposed algorithm is compared with those of the basic GRASP, heuristics based approach, and the Lingo solver using seven problems of different sizes.
In a world where communication requires ever faster data transmission capable of transmitting high speeds. In order to reach and transmit this high speed, it is necessary to increase the frequency that carries the information. For this, scientists are interested in the terahertz (THz) range which, thanks to its high frequencies between 0.1 THz and 30 THz, offers the possibility of increasing the data rate. This letter presents the inclusion of Dodecagon Split Ring Resonator (D-SRR) in rectangular microstrip patch antenna and its effect in the performance of the proposed antenna. The metamaterial design employs two types of SRRs resonators shapes such as the Dodecagon Broadside Coupled Split Ring Resonator (DBC-SRR) and Dodecagon Split Ring Resonator (D-SRR). The model applied uses a local field approach and allowed to obtain the dispersion characteristics of discrete negative magnetic permeability. The proposed antenna substrate uses Arlon AD1000 material, which helps to attain high gain and good directivity at THz frequency. The antenna performance is investigated with and without superstrate. The operating frequencies of the proposed antenna vary in the range of 0.66 - 0.69 THz and shows maximum gain of 10.4 dB and maximum directivity of 9.84 dB. HFSS software tool helps to simulate the parametric analysis of the proposed antenna design. This novel structure may find applications in terahertz imaging, remote systems and may find manifold possibilities in the medical field.
Latent heat thermal energy storage (LHTES) units can store important amounts of energy by employing phase change materials (PCMs). PCMs have a relatively inadequate thermal conductivity which hinders the thermal performance of LHTES. Thus, it is imperative to take measures to improve thermal conductivity or heat transfer within LHTES units. This article examines the heat diffusion improvement within wavy snowflake-shaped containers filled with nano-enhanced PCM (NEPCM). N-Octadecane enhanced with Al2O3 nanoparticles, respectively, are used as nanoparticles and PCM. A numerical model was developed using the standard Galerkin Finite Element Method to analyze the phase change phenomenon. The thermal performance of the LHTES is determined using thermodynamics' first and second laws. The effects of nanoparticle volume fractions (φ) and geometry parameters on the melting rate are investigated. The major findings revealed that the melting process could be well controlled using a lattice of heated fins. Also, the growth in waviness parameter and φ enhances the rates of the heat transfer and average liquid fraction.
This manuscript investigates the thermal energy storage of nano-improved phase change material (NIPCM) used in a corrugated or undulated channel in heat exchangers. The problem is solved in two dimensions. The solution of the equations system is obtained by the Galerkin finite element method, and the enthalpy analysis is also performed. Flat, sinusoidal waves, square waves, triangular waves, and sawtooth wave profiles are considered different geometries of the plates. The impacts of Reynolds number (Re = 500–2000), inlet temperature (T = 65–80 °C), and nanoparticle volume fraction (φ = 0–8 %) on the thermal performance of heat exchangers are also investigated. The heat transfer fluid (HTF) between the plates is water, while the shell is filled with NIPCM (Cu-Paraffin). As the main outcome, the sinusoidal wave profile had the maximum average temperature and entropy, among other cases. Out of all the cases that were examined, the sawtooth plate had the best performance. At the highest values of Re, tin, and ϕ, the sawtooth plate reduced the melting time by 12 %, 11 % and 12 % compared to the flat plate, respectively.
In this study, the essential oil of leaves Eucalyptus globulus (Myrtales: Myrtaceae) was analyzed by gas chromatography/mass spectrometry (GC/MS) and their potential insecticidal against the olive fruit fly Bactrocera oleae (Diptera: Thephritidae) was investigated. The essential oil yield was 0.36 ± 0.03% (w/w). A total of 41 compounds (99.99%) were identified. (-)-spathulenol (32.66%), o-cymene (28.30%) and (+-)-cryptone (12.13%) were major constituents. The toxic impact of essential oil of E. globulus was assessed against B. oleae adults through two toxicity tests (contact and fumigation). B. oleae was more susceptible to E. globulus and adult mortality increased according to concentration and exposure time. In the contact toxicity, the lethal concentration LC50 values were 0.24 µL/cm² and 0.15 µL/cm² in 24 h and 48 h, respectively and LC90 values of 0.64 µl/cm² and 0.33 µL/cm² were obtained in 24 h and 48 h, respectively. In fumigation assay on olive fruit fly adults, LC50 values were 14.05 μL/L air and 5.71 μL/L air at 24 h and 48 h, respectively and LC90 values of 51.53 μL/L air and 21.64 μL/L air at 24 h and 48 h, respectively. The findings of current study show that use of essential oil of leaves of E. globulus against B. oleae is considered as an eco-friendly alternative natural insecticide.
In this work, the numerical investigation was conducted for the MHD natural convec-tion and entropy generation characteristics of water-based hybrid nanofluid (Fe 3 O 4-MWCNT) in a porous annulus between a cooled circular cylinder and a heated Koch snowflake subjected to a uniform magnetic force. The novelty of this work is presented by the special shape and different studied positions of the hot barrier. The governing equations are explained by employing the Finite Element Method. The impacts of nanoparticle volume fraction (u = 2 %, 3%,4%, and 5 %), Ray-leigh number (Ra = 10 3 to 10 6), Hartman number (Ha = 0,25,50,100), Darcy number (Da = 10-2 , 10-3 , 10-4 , and 10-5), and the position of the Koch snowflake (four cases) on the distributions of iso-therms, streamlines, average Nusselt number (Nu avg) as well as on total entropy generation and Bejan number are thoroughly examined. The computational outcomes indicate that increasing the Ra number is possible by changing the temperature between the hot and cold sources. By increasing this parameter, the buoyancy force of the fluid is strengthened. As the Da number increases, the penetration of the flow cross-section in the cavity increases, and the flow circulates in the cavity with less depreciation due to the buoyancy force. Applying Lorentz force, if not in the direction of natural flow, causes the flow velocity to be depleted and fluid flow in the cavity THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Alexandria University. This is an open access article under the CC BY-NC-ND license ( Please cite this article in press as: A. Mourad et al., MHD natural convection of Fe 3 O 4-MWCNT/Water hybrid nanofluid filled in a porous annulus between a circular cylinder and Koch snowflake3O 4-MWCNT/Water hybrid nanofluid filled->, Alexandria Eng. J. (2022), to be facilitated. With increasing Ra number, the application of Lorentz force with different intensities becomes important due to the importance of fluid circulation in the cavity. Applying a Lorentz force with a higher Ha number at high Ra numbers reduces heat transfer due to junction balance and flow separation on hot and cold surfaces. In the lower Ra numbers, the Bejan number tends to 1, indicating a significant increase in the temperature gradient in the cavity and the expansion of the thermal boundary layer at low fluid velocities. At the highest Ra, increasing Ha from 0 to 100 decreases Nu avg by 50 %, while decreasing Da from 10 À2 to 10 À5 reduces Nu avg by 70 %. Ó 2022 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Alexandria University. This is an open access article under the CC BY-NC-ND license ( licenses/by-nc-nd/4.0/).
Nowadays, the vehicle routing problem is one of the most important combinational optimization problems and it has received much attention because of its real application in industrial and service-related contexts. It is considered an important topic in the logistics industry and in the field of operations research. This paper focuses on the comparison between two metaheuristics namely the Genetic Algorithm (GA) and the Discrete Artificial Bee Colony (DABC) algorithm in order to solve the vehicle routing problem with a capacity constraint. In the first step, an initial population with good solutions is created, and in the second step, the routing problem is solved by employing the genetic algorithm which incorporates genetic operators and the discrete artificial bee colony algorithm which incorporates neighbourhood operators which are used for improving the obtained solutions. Experimental tests were performed on a set of 14 instances from the literature in the case of which the related number of customers ranges typically from 50 to 200, in order to assess the effectiveness of the two employed approaches. The computational results showed that the DABC algorithm obtained good solutions and a lower computational time in comparison with the GA algorithm. They also indicated that the DABC outperformed the state-of-the-art algorithms in the context of vehicle routing for certain instances.
In this study, the effect of employing ZnO/Acalypha Indica leaf extract (ZAE) on the energy absorption of a coated portable solar cooker has been examined using an experimental setup. A prototypical model has been developed to corroborate in associating an investigative outcome per constituents of the experiments. The studied heat transfer process in ZAE is stable for harsh conditions. The design analysis and an estimation of the system performance were done given various parameters including the pressure of the vacuum envelope, bar plate coating digestion, emissivity, and solar rays. The fabricated solar was tested with and without ZAE to investigate the impact of this coating material on the solar cooker’s thermal performance. To observe the performance of the new design, two figures of merit (F1 and F2) have been introduced. The factual food cooking assessments were for a family of four people, which operated in ZAE coating (0.8, 1.0, 1.2 μm) of the solar cooker. The values of F1 and F2 for the proposed cooker were obtained as 0.1520 and 0.4235, respectively, which is intact with the BIS values. The results revealed that employing ZAE instead of a thermal NHC-PV solar cooker reduced the time required to boil 2 L of water for about 47 min. The overall thermal energy productivity of the solar cooker with electrical backup was obtained as 42.65%, indicating that the ZAE coating can improve the thermal efficiency by 10.35%.
Nanofluids contains tiny particles in the working liquid due to which heat conduction is raised appreciably. Further, existence of the motile microorganisms boosts the thermal and mass transport in the system and so the improvement is developed in the stability of nanofluid. In this perspective, the emphasis of the existing analysis is to explore the effect of magnetism on the stream bioconvection nanoliquid via porous media under the influence of heat radiation driven by stretching surface. The present flow situation of PDEs is remodeled invariantly to nonlinear ODEs using similarity variables. Further, classical Keller-box technique is implemented to deal with the transformed model. The physical characteristics of flow restrictions over velocity, energy, concentration and density profile are plotted and discussed. With elevation in porosity, thermal buoyancy and slip boosted the microorganism nanofluid flow velocity. Due to induced electromagnetic force velocity is reduced with rise of magnetic term. Except Prandtl number all the considered thermofluidic terms encourages heat propagation and diffusion. A strong boost in species mass distribution is observed with an increase in ther-mophoretic term due to high propelled of the chemical reaction. Overall magnitude of the microorganism motile density is damped for various examined thermophysical parameters. ARTICLE HISTORY
Figurative language is part of our everyday life where meaning is communicated indirectly. Metaphor is among the major figurative devices that are commonly encountered in interactions. This study investigates the use of metaphors employed to conceptualize abstract concepts, namely that of anger in both English and Arabic. For this purpose, a corpus of metaphorical expressions denoting anger in both languages was utilized. These expressions were classified based on their metaphorical mappings and later analyzed using Kövecses’ (2002) framework. The results indicate that although the two languages share several anger conceptualizations, they have specific differences. These differences were attributed to language differences, in that language genius and vocabulary repertoire often influence the conceptualization process. Culture also proved to be another source of elements like climate and lifestyle that manipulate the conceptualization process. The study of metaphorical conceptualization of emotions in general and anger in particular in the Arabic language is a prospective topic that requires further research.
In this paper, we propose three kinds of substrate-integrated waveguide (SIWs) based chamfered bend power divider junctions provide equal power distribution to all output ports while maintaining high isolation and operating in the 54 GHz to 60 GHz frequency band. The advantages of the SIW technology are ease of design, fabrication and low form and full integration with planar printed circuits. In this case, the concept of the SIW H-plane power divider is implemented using a rigorous two-dimensional quick finite element method (2D-QFEM) programmed by MATLAB software. The numerical performance of this method is the Quick simulation time for using the mesh with Delaunay regularization in two dimensions, if we increase the mesh the FEM gives better results. This paper presents the transmission coefficient, return loss and the electric field distribution. The results obtained from QFEM were compared with those provided by HFSS for validation. When using the discretization with the Delaunay procedure only in two dimensions, we notice that the calculated simulation time decreases with good precision.
In this research, we are interested to study the physical properties of the double perovskite oxide Ba2GdNbO6 under the effect of octahedral tilting, where this material crystallises in the tetragonal structure (I4/m (no. 87), Z = 2). The structural, electronic and magnetic properties are investigated using the spin-polarised density functional theory within the framework of the GGA + U approximation. The structural stability for Ba2GdNbO6 compound has been verified; this shows that I4/m structure is reported as stable ground state of Ba2GdNbO6 compound. The phenomenon of octahedral tilting contributes to the stability of this material and to the apparition of the quantum aspect. The X-spectra study show that the structural transition can occur between the I4/m symmetry system (the stable ground state) and the Fm3¯m symmetry system (the excited state), the absorbed radiation of this structural transition corresponds to the Middle-Wave-Infrared (MWIR). The electronic structure of Ba2GdNbO6 compound has been investigated in the stable ground state; the results show that the octahedral Ba2GdNbO6 compound has semiconductor behaviour with an indirect band gap. The results of total and partial spin-magnetic moments of Ba2GdNbO6 compound show that the main contribution to the total magnetic moment comes from the Gd ion, it is obvious to note that the half-filled in Gd (4f⁷) orbital is responsible for the semiconductor behaviour. Moreover, the GGA + U approximation supported by QTL programme shows that the multiplicity in the occupied 4f-Gd states is corresponding to the lower energy level of (⁸S(72)↑).
An ultrasound-assisted method was used for the extraction of phenolics from defatted black cumin seeds (Nigella sativa L.), and the effects of several extraction factors on the total phenolic content and DPPH radical scavenging activity were investigated. To improve the extraction efficiency of phenolics from black cumin seed by ultrasonic-assisted extraction, the optimal extraction conditions were determined as follows: ethanol concentration of 59.1%, extraction temperature of 44.6 °C and extraction time of 32.5 min. Under these conditions, the total phenolic content and DPPH radical scavenging activity increased by about 70% and 38%, respectively, compared with conventional extraction. Furthermore, a complementary quantitative analysis of individual phenolic compounds was carried out using the HPLC-UV technique. The phenolic composition revealed high amounts of epicatechin (1.88–2.37 mg/g) and rutin (0.96–1.21 mg/g) in the black cumin seed extracts. Ultrasonic-assisted extraction can be a useful extraction method for the recovery of polyphenols from defatted black cumin seeds.
The widespread ‘griotte’ facies of the Late Devonian (Frasnian to Famennian) in the Ben-Zireg area of the Bechar basin (Southwestern Algeria) is described here from three sections (BZI, BZII and BZIII) which have been sampled bed-by-bed from the ‘Griotte’ limestone of the Ben-Zireg Formation. Based on macro- and microfacies analysis, this formation has been divided into three members: the Lower Member consists of ‘griotte’ limestone, the Median Member consists of clayey-limestone ‘griotte’, and the Upper Member consists of shales with intercalations of ‘griotte’ limestone. The ammonoid specimens recolted in this formation allow to characterize three Late Devonian biozones: the Cheiloceras Zone (UD II) of Early Famennian, the Gonioclymenia (UD V) and the Kalloclymenia (UD VI) zones of Late Famennian. Based on the field observations and the analysis of 270 thin sections, six microfacies types (MFT-1 to MFT-6) have been identified. They are dominated by biomicritic wackestones and mudstones characterizing a quiet marine environment corresponding to a distal ramp with deposits containing tempestites echoes and internalites fine grained supplies.
The Ouarsenis Massif belongs to the Algerian Tell domain, which is considered as the eastern part of the Maghrebian Tethys former margin. The Berriasian-Valanginian Oued Fodda Formation outcropping in the Kef Aïn El Hadjela section, at the foot of the great peak of the Ouarsenis Massif, is composed of marls and laminated and bioturbated limestone alternations. The marl facies reveals diverse microfauna, including crinoids. These latter are represented by: Isocrinida [isocrinids Balanocrinus cf. gillieroni (de Loriol), Perce-valicrinus aldingeri Klikushin, Isocrinus? lissajouxi (de Loriol)], Cyrtocrinida [cyrtocrinids (Phyllocrinus sp., Hemibrachiocrinus sp.)], and Roveacrinida gen. indet. sp. indet. [roveacrinids]. All these, with exception of roveacrinids and phyllocrinids, are noted for the first time from Algeria and African continent (southern margin of Tethys in the Maghreb). Knowledge on Cretaceous crinoids formerly described from Algeria is presented. It is also shown that crinoid assemblage and associated invertebrates are typical for relatively shallow, distal depositional setting situated below storm wave base.
Recently, phase change materials (PCMs) have gained great attention from engineers and researchers due to their exceptional properties for thermal energy storing, which would effectively aid in reducing carbon footprint and support the global transition of using renewable energy. The current research attempts to enhance the thermal performance of a shell-and-tube heat exchanger by means of using PCM and a modified tube design. The enthalpy–porosity method is employed for modelling the phase change. Paraffin wax is treated as PCM and poured within the annulus; the annulus comprises a circular shell and a fined wavy (trefoil-shaped) tube. In addition, copper nanoparticles are incorporated with the base PCM to enhance the thermal conductivity and melting rate. Effects of many factors, including nanoparticle concentration, the orientation of the interior wavy tube, and the fin length, were examined. Results obtained from the current model imply that Cu nanoparticles added to PCM materials improve thermal and melting properties while reducing entropy formation. The highest results (27% decrease in melting time) are obtained when a concentration of nanoparticles of 8% is used. Additionally, the fins’ location is critical because fins with 45° inclination could achieve a 50% expedition in the melting process.
With the need of sustainable agroecosystem, pest management is becoming imperative. Nowadays, it is known that essential oils are potent molecules with high potential for plant protection. These advantages have encouraged scientists to intensively screen for the plants biomolecules as promising candidates for pest management to replace currently used chemical pesticides. The application of such as technology for the removal of these insects has received much attention and led to the development of effective, economic and environmentally friendly technologies. In this study, a metabolomic approach was used to investigate the characterization of three pheromones, identified by gas chromatography-mass spectrometry (GC-MS) as α-Bergamotol , β-farnesene, Isobombykol.
In this manuscript, phase change material (PCM), as a thermal energy storage medium, is considered within a 3D wavy cubic enclosure to investigate the effect of free and mixed convection heat transfer on the PCM melting process. Rotating cylinders also are located in the middle of the enclosure to study the effect of their angular velocity in different conditions. Governing equations are solved by Galerkin Finite Element Method (GFEM) and were confirmed by previous studies. As main outcomes, results with enhanced angular velocity, the average temperature, and entropy generation were significantly decreased. Results showed that as the melting process is helpful for thermal energy storage systems, it is recommended by this study to have a rotating cylinder inside the PCM domain and the undulation number of the hot surfaces not to exceed one. It was shown that the cylinder rotation of -5 rad/s enhances the melting process speed by about 88% compared to the stationary cylinder, and about 186% of melting enhancement can be obtained for the undulation number of 1 instead of 4.
Advanced studies on modern electronic devices using the filter function show the impact of multi-band filters on the electrical qualities of these devices. Due to the importance of its electromagnetic characteristics, the dual-band bandpass microwave filters can be used in several high-quality electronic devices. In this paper, a dual-band bandpass filter (DBBPF) is provided. The proposed filter is inspired by a pair of tapered split-ring metamaterial resonators of the same asymmetric square coupled interlinked shape (SCI-SRR) and of different sizes. The choice of the two resonators, which have a negative permeability (μ< 0), is made such that the magnetic resonance of each resonator appears in X-band. The designed filter consisting of these SCI-SRRs is fed in parallel mode by two microstrip lines and etched on the upper face of the used substrate. Both SCI-SRRs which are coupled to the feed lines are interconnected by a folded microstrip line to have the necessary miniaturization of the filter. The electrical dimensions of our DBBPF are (1.305 λ0× 0.913 λ0) mm2, for which λ0 is the wavelength of the lowest frequency calculated at 9.89 GHz. Numerical calculations using the finite element method (FEM) based on high-frequency structure simulator software are performed to design this filter. The two filter bandwidths, which are obtained as a function of the rings widths of the tapered metamaterial resonators (α,β), are considered in the X-band, they are of the order of 186.2 and 89.7 MHz, respectively. To validate our work, we compared our obtained results with the other recent work results for the same field of research.
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.
1,001 members
Mohammed Sahnoun
  • Physics Department
Rabah Khenata
  • Depatment of sciences & Technology- University of Mascara-Algeria
H. Baltach
  • Department of physics
Bp 305 Route d'Oran, 29000 Mascara, 29000, Mascara, Mascara, Algeria
Head of institution
Prof BENTATA Samir
+213 45 70 70 04
+213 45 70 70 03