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Item Open Access Enhanced investigations and modeling of surface roughness of epoxy/ Alfa fber biocomposites using optimized neural network architecture with genetic algorithms(2023) Madani Grine; Mohamed Slamani; Aissa Laouissi; Mustapha Arslane; Mansour RokbiCurrently, there is a notable attraction within the industry towards biocomposites, driven by the increasing fascination with natural fber-reinforced composites (NFRCs). These NFRCs ofer remarkable benefts, including cost-efectiveness, biodegradability, eco-friendliness, and favorable mechanical properties. As a result, the manufacturing processes of natural fber reinforced polymer (NFRP) composites have garnered attention from both industrial professionals and scientists. The emergence of these eco-friendly materials in the automotive and aerospace industries has sparked interest in understanding their production techniques. However, the machining processes of NFRP composites pose signifcant challenges due to the complex structure of natural fbers, necessitating thorough studies to address these issues efectively. This research paper presents a comprehensive investigation on surface roughness during the milling process of Alfa/epoxy biocomposites. A set of 100 experimental trials was conducted to test the surface roughness, and analysis of variance (ANOVA) was used to assess the impact of cutting parameters and chemical treatment on surface quality. To develop a predictive model for surface roughness, a hybrid approach called ANN-GA (artifcial neural networks-genetic algorithms) is proposed in this research. This approach combines ANN and GA to determine an optimal neural network archi tecture. The performance of the ANN-GA model is compared to the Levenberg–Marquardt backpropagation (LM) algorithm. ANOVA results show that the feed per revolution have a signifcant infuence on surface roughness, followed by the chemi cal treatment of fbers, while machining direction has a smaller efect. The ANN-GA model demonstrates good accuracy in surface roughness prediction compared to the LM algorithmItem Open Access Analytical assessment of Ain Skhouna PV plant performance connected to the grid under a semi-arid climate in Algeria(université de msila, 2021) Mohamed El hassen Jed; Razika Ihaddadene; Nabila Ihaddadene; Amaury De SouzaAlgeria currently has a number of 24 functional photovoltaic power plants on its national territory, which are poorly investigated. This study focuses on the performance analysis of one of these existing solar power plants. It is located in Ain Skhouna, situated in Saida province, and has a capacity of 30 MWp (polycrystalline solar cell technology). This study was carried out according to the standardized norms IEC 61,724 (IEC) using one year (2018) of data. A linear relationship between the monthly module and ambient temperatures was evaluated (R2 = 0.994). The monthly total loss increases linearly with the increase in monthly ambient temperature and solar irradiation (R2 = 0.98). The system efficiency, PV efficiency, and performance ratio are affected by ambient temperature. The average monthly PV, system, inverter efficiencies, and PR were 13.78%, 13.29%, 96.68%, and 85.52, respectively. These results indicate that this PV power plant remains in very good working condition after two years of service. The effect of climate on PV plant performance was investigated in Algeria by comparing two climates: a semi arid and a hyper-arid. The results indicate that the semi-arid climate is more favorable than the desert climate for PV power plants for producing electricity and that ambient temperature is a more essential parameter than solar irradiation.Item Open Access Nous présentons dans cette thèse une simulation numérique de la convection mixte d’un fluide électriquement conducteur en rotation dans un espace annulaire entre deux cylindres coaxiaux verticaux. La stabilité de l’écoulement est obtenue en appliquant un champ magnétique externe. Cette recherche vise à étudier la zone d’éclatement tourbillonnaire, la marge de stabilité et les couches fluides de l'écoulement en rotation entre deux cylindres coaxiaux verticaux sous l'effet d'un gradient thermique et d'un champ magnétique axial. Les équations gouvernantes de Navier Stokes, de température et de potentiel électrique sont résolues à l'aide de la méthode des volumes finis. Cette étude est divisée en deux parties : la première partie présente un fluide visqueux conducteur (l'alliage plomb-lithium (PbLi)) caractérisé par un petit nombre de Prandtl (Pr=0.032) et placé dans l'espace entre deux cylindres coaxiaux. La combinaison du rapport d'aspect, γ=1.5 et du nombre de Reynolds, Re=1500 pour trois espaces annulaires (R=0.7,0.8 et 0.9) est comparée en termes de stabilité d'écoulement et de taux de transfert de chaleur. Sans champ magnétique, la décomposition du vortex se produit près du cylindre intérieur en raison de l'action croissante de pompage d'Ekman. Les structures en couches fluides sont développées par la compétition entre la flottabilité et les forces visqueuses. L'augmentation de l'amplitude du champ magnétique ralentit l'apparition de l'instabilité oscillatoire et provoque la disparition de l’éclatement tourbillonnaire (vortex breakdown) et réduit le nombre de couches fluides. Les limites dans lesquelles le vortex breakdown se manifeste et la limite de transition entre multiples couches de fluide et une seule couche de fluide sont établies. La deuxième partie de cette étude présente une comparaison de trois combinaisons de rapports d'aspect (γ) et de nombres de Reynolds (Re). L'action de pompage établit une circulation secondaire le long du plan méridien de l'espace annulaire. Pour certaines combinaisons, l’éclatement de vortex s'est produit près de la paroi interne. La bifurcation sous forme de plusieurs couches de fluide devient apparente lorsque la différence de température dépasse une valeur critique. Ces couches fluides jouent le rôle d'isolant thermique et limitent les échanges thermiques entre le haut chaud et le bas froid des cylindres coaxiaux. La décomposition du vortex et les couches de fluide pourraient être supprimées par le champ magnétique; l'augmentation du nombre de Hartmann (Ha) freine l'écoulement peut être. Des diagrammes représentant l'effet de l'augmentation du nombre de Richardson (Ri) sur les couches fluides sont établis. Ensuite, des diagrammes de stabilité correspondant à la transition de la zone à plusieurs couches de fluide vers la zone à une seule couche de fluide en fonction du nombre de Prandtl (Pr) sont obtenus(université msila, 2021) H. Benhacine; B. Mahfoud; M. SalmiThis research aims to investigate the vortex breakdown zone, the stability margin, and the fluid layers of the rotating flow between two vertical coaxial cylinders under the effect of thermal gradient and an axial magnetic field. The governing Navier-Stokes, temperature, and potential equations are solved using the finitevolume method. Three combinations of aspect ratios (γ) and Reynolds numbers (Re) are compared. The pumping action sets up a secondary circulation along the meridional plane of the annular gap. For certain combinations, the vortex breakdown bubble occurred near the inner wall. Bifurcation in form of multiple fluid layers becomes apparent when the temperature difference exceeds a critical value. These fluid layers play the role of thermal insulation and limit the heat transfer between the hot top and cold bottom of the coaxial cylinders. Both the vortex breakdown and fluid layers could be suppressed by the magnetic field; the increasing of Hartmann number (Ha) would reduce the number of fluid layers. Diagrams represent the effect of increasing Richardson number (Ri) on fluid layers are established. Then stability diagrams corresponding to the transition from the multiple fluid layers zone to the one fluid layer zone for increasing Prandtl number (Pr) are obtained.Item Open Access Correlation assessment and modeling of intra‑axis errors of prismatic axes for CNC machine tools(université M'sila, 2023) Ahlem Mechta; Mohamed Slamani; Moussa Zaoui; René Mayer; Jean‑François ChatelainThis paper presents an experimental study conducted to assess the correlation between the intra-axis errors of prismatic axes for CNC machine tools. The validity and reliability of parametric models for the modeling of intra-axis errors (IAEs) of CNC machine tools in the context of indirect calibration are also assessed in this work. Three CNC machine tools with various controllers and guidance technologies were tested using two different measuring instruments. Two predictive models, namely Bézier and B-spline curves, are described and compared for the first time in this work. Both models are experimentally evaluated for accuracy and predictive efficiency using four evaluation criteria and new data sets from the three tested CNC machine tools. Results show a strong correlation between the positioning errors and the pitch and yaw errors for all the tested machines. The results also show that both proposed models are appropriate for the modeling of intra-axis errors, with the B-spline curves coming slightly on top in terms of performance. Moreover, with the same number of control points (n = 5), the two models provide residuals that are lower than the repeatability of the machine for most intra-axis errors tested. This experimental study thus confirms that a Bézier model of degree four and a B-spline model of degree two, both with five control points, are sufficient to represent the intra-axis errors for the tested CNC machine toolsItem Open Access Solar Energy in M’Sila (Algerian Province)(Université de M'sila, 2022) Younes Kherbiche; Nabila Ihaddadene; Feres Hadji; Razika Ihaddadene; Merouan MostefaouiAn accurate knowledge of solar radiation data for a given location is required for any project aimed at exploiting solar energy. The present paper evaluates the solar energy potential of M'Sila, (internal region of Algeria). This assessment is made based on data collected at the M'Sila weather station for 365 days by 5-minute intervals. The study site is located at a latitude of 35° 42`07``, longitude of 4° 32`43`` and an altitude of 441 m above the sea level. The maximum radiation received in M'Sila during the day does not occur at a fixed time during the year. It fluctuates around an average value of 11:40. This maximum radiation was recorded between 9:14 and 13:59. The representative days of the radiation reaching the ground of M'Sila are different from those relating to extra-terrestrial radiation. They vary from year to year. The month of July is the sunniest month in M’Sila with a total insolation of 790.14 MJ/m2. The month of December is the least sunny month with a total insolation of 242.52 MJ/m2. M'Sila receives a total solar energy of 6316.42 MJ/m2 per year. That means an average insolation of 526.37MJ/m2 per month and 17.31 MJ/m2 per day. M'Sila has an important solar energy potential that deserves to be exploited.Item Open Access Assessment of the Resources of Wind Energy in Various Regions of Algeria(Université de M'sila, 2022) Derradji MederregDetails on the wind potential during a period of about thirteen years in Algeria is given in the present work. The inspection is performed for sixteen regions covering almost all the territory of the country. The density of the mean wind power is determined for the different regions. The maps of annual and seasonal wind energy resources are also established. The characteristics of the wind velocity, as well as the potential of wind power, are determined by the Weibull distribution. From the given results, the highest values of annual mean wind speed and the annual mean wind power density are found in Adrar (P10 = 283.12 W/m2 and P50 = 646.91 W/m2), while the lowest values are observed in Skikda (P10 = 40.61 W/m2 and P50 = 115.51 W/m2, respectively).Item Open Access Assessment of the quality of continuous evaluation in the LMD system from the viewpoint of teachers - a field study at the University of Akli Mhaned Oulhadj Bouira -(Université de M'sila, 2022) قوادري سارةتناولت الدراسة الحالية موضوع جودة التقويم المستمر الممارس وفق نظام LMD، حيث هدفت إلى معرفة تقييمات الأساتذة لجودة التقويم المستمر وفق نظام LMD بعد مرور 16 سنة على بداية اعتماد هذا النّظام في الجامعات الجزائرية، ومعرفة ما إذا كانت هناك فروق في تقييماتهم تعزى لمتغيرات: الدرجة العلمية، التخصص وسنوات الخبرة. ولتحقيق أهداف الدّراسة تم استخدام المنهج الوصفي بالاعتماد على أداة الاستبيان المُصمم من طرف الباحثة والمكوّن من 28 عبارة موزعة على خمسة محاور، تم توزيعه بعد التأكد من خصائصه السيكومترية على عينة مكونة من 83 أستاذ وأستاذة تم اختيارهم بطريقة عشوائية منتظمة من مختلف كليات جامعة آكلي محند أولحاج بالبويرة، وقد توصّلت الدّراسة إلى عدة نتائج أهمها: مستوى جودة التقويم المستمر الممارس وفق نظام LMD متوسط بشكل عام بحيث كان: - مستوى جودة التقويم المستمر حسب معايير الشمولية والاستمرارية متوسّط. - مستوى جودة التقويم المستمر حسب معيار الموضوعية متوسّط. - مستوى جودة التقويم المستمر حسب معيار الفاعلية متوسّط. - مستوى جودة التقويم المستمر حسب معيار السّهولة والاقتصادية منخفض. - مستوى جودة التقويم المستمر حسب معيار مراعاة الفروق الفردية منخفض. كما أظهرت النتائج أيضا أنه لا تُوجد فروق ذات دلالة إحصائية في تقييمات الأساتذة لجودة التقويم المستمر تُعزى لمتغيرَيْ الدّرجة العلمية وسنوات الخبرة، فيما كانت هناك فروق ذات دلالة إحصائية فيItem Open Access و اقع التقويم التربوي في الجامعة الجزائرية و اقتراح تصور لتطويره في ضوء معايير جودة التعليم -دراسة ميدانية بجامعة المسيلة(Université de M'sila, 2022) قوادري سارةتناولت الد ا رستة واقتق التقتويم الترجتوي االجامعتة الج ا زئريتةو واقتت ا رح تصتور لتطتويرد فتي ضتو، معتا ير جتودة التعلتيمو وهدف إلى التعرف على مستوى ممارسة أساتذة الجامعتة للتقتويم الترجتويو وتحد تد الصتعوجاي التتي تتواجاام أ نتا، ذلكو والاستفادة من نتائج الد ا رستة الميدانيتة ومعتا ير جتودة التعلتيم فتي تطتوير التقتويم الترجتوي االجامعتة الج ا زئريتة. استتمدم الباة تة فتي ذلتك المتناج الولتفي التحليلتيو كمتا تتم الاعتمتاد علتى أداة الاستتبيا المصتمم متن طترف الباة ةو وتم ل عينة الد ا رسة في 963 أستتاذ متن ممتلتل كليتاي جامعتة المستيلة. وتولتل الد ا رستة إلتى النتتائج التالية: -1 يمارس أساتذة الجامعة التقويم الترجوي امستوى متوسط احيث: - يمارس أساتذة الجامعة الم ا رقبة المستمرة امستوى متوسط - يمارس أساتذة الجامعة التقويم الناائي امستوى متوسط - يمارس أساتذة الجامعة التقويم عن اعد امستوى منمفض -2 توجد فروق ذاي دلالة إةصائية في مستوى ممارسة أساتذة الجامعة للتقويم الترجوي تعزى لمتغير ميدا التمصص الماني وهاته الفروق كان لصالح ذوو التمصصاي )التكنولوجيا والعلوم والرياضياي والإعلام الآلي( -9 توجد فروق ذاي دلالة إةصائية في مستوى ممارسة أساتذة الجامعة للتقويم الترجوي تعزى لمتغير الأقدمية وهاته الفروق كان لصالح فئة الأقدمية من 11 سنواي وأك ر -4 لا توجد فروق ذاي دلالة إةصائية في مستوى ممارسة أساتذة الجامعة للتقويم الترجوي تعزى لمتغير تكوين الأساتذة الجدد -5 واجه الأساتذة أ نا، ممارستام للتقويم الترجوي لعوجاي متعلقة االجانب البيداغوجي النتظيميو لعوجاي متعلقة االطالبو ولعوجاي متعلقة االأستاذ نفسه. -6 تم اقت ا رح تصور لتطوير التقويم الترجوي االجامعة الج ا زئرية في ضو، معا ير جودة التعليم.Item Open Access Characterization of physical and mechanical properties of recycled jute fabric reinforced polypropylene composites(Université de M'sila, 2022) Lamia BenhamadoucheThis research designed to contribute to reduce the environmental impacts through the preparation of composites with recyclable materials to be used in different applications. To this end, composites have been developed based on jute recovered from packaging bags and polypropylene (PP) reclaimed from scraps obtained from the manufacture of PP yarns. The developed composites were then characterized. First of all, the optimum mass fraction was determined in order to achieve good mechanical performance. Several mass fractions (30%, 40%, 45%, 50%, 60%, and 70%) were experimented to find that the best characteristics were those of the biocomposite with 40% reinforcement (σ = 39.07 MPa, E = 4.60 GPa). With this ratio, jute–PP biocomposites were further developed with different jute architectures (Satin, Serge 2 2, Taffeta). A structural study of the different jute fabric wastes was carried out to confirm whether they are suitable for use with a thermoplastic matrix (i.e., at a processing temperature of ≥200 C). Tensile and bending tests were carried out on these composites to find out the effect of the weave structure of the reinforcement.Item Open Access Development and validation of a machining fixture for complex-shaped components based on Plückerian matrix approach and SDT concept(Université de M'sila, 2020-09) Mustapha, ArslaneIn the manufacturing industry, there are several types of parts of complex shapes owning various functions. The turbine blades (buckets and vanes) are one of the most important components in gas turbines. However, these blades have complex shapes and irregular surface curvature which make them difficult to machine. Production of such kind of parts is so complicated and requires a high control of machining process, advanced CNC programming, innovative tools, and special fixtures allowing to maintain exactly and rigidly in a unique position of the part during machining. In order to enhance productivity and reduce operation time, thereby increasing parts quality, the machining fixture has to fulfill several requirements such as allowing a correct location with security and repeatability of the workpiece as well as maintaining conformity and interchangeability of the machined parts. This paper addresses the challenge of machining complex geometry parts by development and realization of a dedicated machining fixture (MF) for holding a mobile blade of a gas turbine. The first novelty of this work is in the application of the Plückerian coordinates method for choosing the locator’s placement of complex-shaped parts. The choice of the locator’s placement during the design process of the fixture is performed based on the maximization of the determinant and minimization of the condition number of the locator matrix (information matrix). The second novelty is in the optimization approach used. The last novelty is in the developed and fabricated machining fixture. The performance of the developed fixture in terms of localization repeatability is evaluated based on the small displacement torsor (SDT) concept. Results show the validity of the developed fixture.Item Open Access NUMERICAL INVESTIGATION OF 3D UNSTEADY FLOW AROUND A ROTOR OF VERTICAL AXIS WIND TURBINE DARRIEUS TYPE H(Université de M'sila, 2021) Amar BerkacheThis article presents an analysis of the complex and unsteady flow associated with the functioning of the rotor of a vertical axis wind turbine Darrieus - H. In this study, the influence of different numerical aspects on the accuracy of the simulation of the flow around a rotor of three straight blades in rotation is performed, which are the effect of the turbulence modeling, and the effects of the mesh and the time step. The Delayed Detached Eddy Simulation (DDES) approach is used. The aim of this article is to describe and analyze the unsteady flow in 3D predicted numerically taking into account the effects of arms like blade-arms interference, blade-wake interactions around the Darrieus rotor and the effect of tip vortices. Two-dimensional simulations are used in a preliminary numerical configuration. Then, three-dimensional simulations are performed in order to precisely determine the characteristics of the complex aerodynamic flow associated with the operation of the wind turbine rotor. The flow field around the rotor is studied forseveral values of the tip speed ratio, dynamic quantities, such as the torque and the power of the rotor, that are presented and analyzed. From the results obtained, it is clear that the approach of the Detached Detached Eddy Simulation with the SST K-ω model can be considered as a reliable prediction. A comparison of the performance of the results showed that the predicted coefficients of performance are very close to the experimental data from the bibliography.Item Open Access EFFECT OF PRE-POST TIG WELDING HEAT TREATMENT ON CAST NI SUPERALLOY(Université de M'sila, 2020) C. SAIB; M. ZAOUI; S. Amroune; H. GhoussThe effect of a preheating (before) and post (after) welding heat treatment on the microstructure and mechanical properties of the scrap blades made of cast INC738LC superalloy is the main goal of the present investigation. The filler used in TIG welding was INC 625 solution hardened superalloyas proposed solution for hot cracking of the cast INC738LC superalloyin literature. The TIG welding was processed with respect to the constant optimized parameters (current, voltage, speed, gas flux rate and number of passes) to make a mechanical properties comparison between as received and the welded superalloy with heat treatedspecimens. The characterization techniques employed in this study are hardness measurements, tensile tests, optical microscopy and scanning electron microscopy. We found that the proposed preheating improves the TIG welding of the INC 738 LC superalloy specimens and the post welding heat treatment as expected enhances its mechanical properties.Item Open Access Characterization and mechanical behaviour of similar and dissimilar parts joined by rotary friction welding(Université de M'sila, 2020-01) Houria, BenkherbacheThis work is a contribution to the study of the rigidity of rotational friction welding of cylindrical specimens made on a parallel lathe. We performed welding of three combinations of parts: steel / steel, aluminium / aluminium and steel / aluminium according to three numbers of rotations of the spindle (900, 1250 and 1800 rpm). To control the rigidity and quality of these assemblies, tensile tests are used followed by ultrasonic testing to ensure that the tips are welded and that there are no internal defects. Hardness profile of the welded zone according to the welding parameters was obtained. Metallographic observations have detected the profile of the various zones welded and affected thermally. The results of the mechanical tests showed that a rotation speed of 1250 rpm can produce a very good weld, with other parameters kept constant.Item Open Access Influence of the heated blocks on the natural convection in 3D cylindrical and divergent annular duct(Université de M'sila, 2019) BENKHERBACHE, SOUADIn this paper, a numerical investigation of natural convection in three-dimensional cylindrical and divergent annular duct is studied. In the inner cylinder of thin thickness, are mounted a cylindrical blocks which subjected to a volumetric heat generation. The governing equations of mass, momentum and energy equation for both the fluid and the solid are solved by the finite volume method using the commercially available CFD software fluent .The effect of the number of heated blocks (N = 1, 2, 3 and 5) and the inclination angle of the divergent (φ = 0°, 15°, 23° and 45°) have been studied . The temperature and velocity contours fields, stream lines also the local Nusselt number have been presented here for Ra = 2.105 and N = 3 while temperature and velocity profiles in the span-wise direction of the flow were plotted for Ra = 1.105 (φ = 0°, 15°, 23° and 45°) and (N = 1, 2, 3 and 5) also the local and average Nusselt number for those geometries.Item Open Access Configuration of wind farm in Kaberten region: wind potential and optimal capacity(Université de M'sila, 2019-10) ZERGANE, SaidThe configuration of a wind farm depends mainly on the wind potential and the disposition of the wind turbines in this park. The windiest site is the most favorable for a future installation of wind turbines for the production of electricity, also, in this same site, a too dense arrangement would lead to considerable of power losses under the effect of wake. In this context, it is presented a research work that consists of determining the installation conditions of a wind farm; evaluating the wind farm through measurements of wind speed and the location of wind turbines in the park to minimize the effect of wind turbine interference. In order to do this, an evaluation study of the wind potential for the implementation of a wind farm based on the quantification of the wind in speed and directions firstly proposed. Secondly, a method for optimizing the positioning of wind turbines in a wind power farm is used based on the introduction of the Jensen wake model and the application of the iterative pseudo-random distribution approach of the turbines in the site. Simulation results are presented and discussed using data from the Kaberten site in Algeria and the characteristics of the GAMESA G52 wind turbine.Item Open Access High-Gradient Magnetic Separation Method for Weakly Magnetic Particles: an Industrial Application(Université de M'sila, 2019) Chouki, FarsiThe high-gradient magnetic separation process is a technique used in heavy industries, particularly steel mills, to extract magnetic particles from mix-tures. The difficulty of separating the slightly magnetic particles from the nonmagnetic ones lies in the distribution of the magnetic field and the fine-ness of their class to be separated. A use of different separation matrix pro-file is implemented, making it possible to act on the value of the gradient of the inhomogeneous magnetic field. Different matrixes are tested and the re-sults obtained experimentally allows to choose the most efficient matrix form in the operation of extraction which increased by 11% in magnetic fraction yield, 15% iron content and 17% of extraction degree relative to the John’s matrix. This matrix used is consistent with that cited in literatures. The sep-aration technology used can extend its useful application to small particles from very weakly magnetic materials. Its exploitation will result in the method of reducing the degree of pollution and improvement the process of extraction of minerals that has an impact on the environment and on humanItem Open Access Study of The Influence of External Parameters on Thermal Performance of a Solar Water Collector(Université de M'sila, 2019) Djedid, TaloubThe purpose of this work is to show the effect of external parameters: albedo and wind speed) on a solar collector inclined plane. The method used consists in cutting the collector into fictitious slices (05 meshes) of length Δx in the direction of the flow of the heat transfer fluid and writing the balance sheets of the exchanges which intervene at the levels of the 06 nodes: from the outside of the glass, the inside of the glass, the absorber, in the peddler fluid as well as the inside and the outside of the insulation. It is convenient for this to use the analogies that exist between the transfer of heat and electricity, the results obtained are the temperatures at the nodes.Item Open Access Computational studies of mono-chalcogenides ZnS and ZnSe at highpressures(Université de M'sila, 2019) Ferahtia, SamiaA pseudopotential study of structural, electronic, elastic and thermodynamic properties of mono-chalcogenides ZnS and ZnSe has been reported. Two phases such as zinc-blende and rocksalt are considered here. The computations are essentially based on the density functional theory within the local density approximation. Physical quantities such as elastic constants and phonon dispersions have been presented. The lattice constants, bulk modulus, entropy and heat capacity and their temperature dependence are analyzed and discussed. Furthermore, the effect of high pressure on the features under investigation of the materials in question is examined.Item Open Access High-Gradient Magnetic Separation Method for Weakly Magnetic Particles: an Industrial Application(Université de M'sila, 2019) Chouki, FarsiThe high-gradient magnetic separation process is a technique used in heavy industries, particularly steel mills, to extract magnetic particles from mix-tures. The difficulty of separating the slightly magnetic particles from the nonmagnetic ones lies in the distribution of the magnetic field and the fine-ness of their class to be separated. A use of different separation matrix pro-file is implemented, making it possible to act on the value of the gradient of the inhomogeneous magnetic field. Different matrixes are tested and the re-sults obtained experimentally allows to choose the most efficient matrix form in the operation of extraction which increased by 11% in magnetic fraction yield, 15% iron content and 17% of extraction degree relative to the John’s matrix. This matrix used is consistent with that cited in literatures. The sep-aration technology used can extend its useful application to small particles from very weakly magnetic materials. Its exploitation will result in the method of reducing the degree of pollution and improvement the process of extraction of minerals that has an impact on the environment and on human health as a result a high level of extraction.Item Open Access A comparison of mixed convective heat transfer performance of nanofluids cooled heat sink with circular perforated pin fin(Université de M'sila, 2019-05) Bakhti, Fatima ZohraThis paper presents a numerical study on the mixed convection of nanofluids in heat sinks with perforated circular fins. Four different types of nanofluids are used as cooling fluids, which are TiO2, Al2O3 and Cu dispersed in pure water as the base fluid. The selected volumetric concentration of nanofluids was chosen in the range (2–10)%. The Reynolds number has changed in the range of 100–400 to ensure that flow remains in the laminar regime and to have the Richardson number 1≤Ri≤22. To study the cooling performance of the heat sink, three-dimensional steady Navier Stokes and energy equations were discretized by the finite volume method using the power-law scheme and have been solved iteratively, using the SIMPLE algorithm. The results show that a significant improvement in heat transfer in the heat sink due to the suspension of nanoparticles in the base fluid compared to pure water, the improvement in heat transfer is intensified with increased Reynolds number and decrease in the volume fraction of nanoparticles. We also found that the low values of the average Nusselt number are obtained for the nanofluid TiO2, the average values for Al2O3 and the highest values for Cu. It is important to note that a slight increase in friction factor and pumping power has been reported when nanofluid is used in the system.