Communications Nationales
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Item Effect of Different Anodizing Bath on Improving the Corrosion Resistance of a 2030 Aluminum Alloy(2019) Benmohamed, Manel; Ben Mounah, A.; Haddad, A.luminum alloys have a considerable appeal for mechanical and building designers. This characteristic lies in the mechanical and physicochemical properties of these alloys. Aluminum is often used in the anodized surface condition to impart pleasing aesthetics, higher corrosion resistance, better scratch and wear resistance, and thus an improved value of the product. Anodization is commonly produced by direct current (DC) that offers excellent protection against wear and corrosion. This work focuses on the surface condition of a treatment (chromic anodizing, sulfo-chromic anodizing) using a structural characterization (MEB) that will be followed by electrochemical characterization. The results obtained have shown the effectiveness of chromic anodizing, which gives rise to the formation of a thin layer and offers excellent protection against corrosion. Chromic anodic oxidation protects an aluminum part by creating a layer of alumina Al2O3, to give it anti-corrosion, decorative and heat resistance characteristics, as well as, any chromic acid residues do not attack the base material. This is the opposite of sulfuric acid, which makes it an excellent pretreatment for aerospace parts.Item Seismic response of concrete gravity dam with soil structure interaction using isogeometric approach.(2019) Lahdiri, Abdelhafid; Kadri, MohammedThe paper deals with the numerical analyses carried out on the Oued-Fodda concrete gravity dam under earthquake shaking with account of soil structure interaction. The seismic behavior of the dam-soil system is performed by the isogeometric approach based on the NURBS shape functions and the water mobilized by the dam is modeled with the Westergaard’s mass added approach usually applied in most of literature studies. The motion equations are solved by the direct integration method of Newmark. The results are compared with the results obtained by SAP code and other authors using the finite element method. The effect of soil structure interaction is evidenced by comparing displacements at the dam crestItem دور الذكاء الانفعالي للقائد في تحقيق تميز المؤسسة(Université M'hamed Bougara de Boumerdès, 2017) تــــــــــوال, آمــــــنةيشكل الذكاء الانفعالي بعدا ضروريا للقيادة، و هو ليس مناف للذكاء المعرفي بل يعتبر مكملا له، لأنه يمنح القائد اتزانا انفعاليا يسمح له باتخاذ قرارات سليمة، حيث إنه يمثل قدرة القائد على فهم و إدارة نفسه وعلاقاته بالآخرين بكفاءة وفعالية، و هذا ما يمنح القائد ميزة فريدة عن غيره ويساعده في تحقيق التميز للمؤسسة؛ ذلك أن التميز يحتاج إلى ابتكار متواصل لتجديده، و التزام بالعمل المستمر لتحقيق الأهداف، و هذا لا يمكن أن يتحقق إلا إذا كان القائد ينشر بيئة تشجع على التعاون البناء والسلوكيات الإيجابية، فعندما يفوق القائد توقعات المحيطين به في اهتمامه بهم، فسيفوقون توقعاته في أدائهم و نتائجهم، و يتجاوبون معه في تحقيق الأهداف المسطرة، و بذلك يصلون معا إلى القمةItem Modélisation du comportement dynamique et simulation de la réponse sismique non linéaire des silos à grains en béton armé.(2019) Benkhellat, Sonia; Seghir, Abdelghani; Kadri, MohammedLes silos à grains sont des ouvrages industriels particuliers utilisés pour le stockage des matières granulaires. Ces ouvrages sont calculés selon des normes sismiques spécifiques dû aux multiples cas de chargements auxquels ils sont soumis. Dans le présent travail, on s’intéresse à la modélisation du comportement dynamique et à la simulation numérique de la réponse sismique non linéaire de ces structures en effectuant des analyses dynamiques non linéaire par accélérogrammes (Time history analyses). Les parois des silos sont des voiles en béton armé dont le comportement non linéaire doit tenir compte des comportements des deux matériaux acier et béton composant leurs sections. Un modèle numérique basé sur les éléments de type coques multicouches (multilayer shell elements) est adopté pour prendre en compte ce comportement mixte. La matière granulaire stockée est modélisée par des éléments solides et par des masses équivalentes. Les résultats obtenus ont permis d’analyser la capacité du silo étudié sous un chargement sismique et d’obtenir l’évolution des contraintes et des déformations dans les aciers et dans le béton en fonction du temps.Item Energy recovery from the treatment water plant of Lakhdaria for electricity production(2019) Iguercha, Amina; Ferhat, B.; Mohammedi, K.; Bouaziz, M.he water that reaches our taps follows a path represented by the pipelines. It must be supplied with energy so that it can circulate along the pipeline, which therefore creates a link between energy and water. Water treatment plants in Algeria consume electrical energy for its pumping and lighting systems. The objective of this work is the study of feasibility of recovering energy at loads breezes which are generally installed on the field to break the water pressure to the reservoir. This gives an opportunity for innovation in the water sector, bringing water and energy without Co2 emissions and with inexhaustible energy and economic able to provide hydroelectric power almost continuously.Item Étude de Danger de l’Entreprise CAMMO(Université M’Hamed Bougara Boumerdes, 2014) Chabane, Ali; Taibi, N.L'objectif de cet article est d’examiné les procédures d’étude de danger de l’entreprise CAMMO. Il s’agissait de se pencher plus particulièrement sur tout ce qui concerne l’évaluation et la gestion des risques technologiques majeurs. On examine en détail le déroulement de la procédure en vigueur et enfin illustré ce déroulement par une étude de cas. Nous avons alors pu faire le bilan de leurs avantages et de leurs inconvénients. En conclusion, nous avons donné les quelques orientations générales qu'il nous paraissait bon de suivre quelque soit la procédureItem Three computational intelligence methods for system reliability(2018) Chebouba, Billal Nazim; Mellal, Mohamed Arezki; Adjerid, SmailNowadays, the competitiveness in the industrial world became more and more harsh, which requires that the system must be as reliable as possible. In many optimization problems, hard fitness functions are considered. Those functions can- not be solved by the traditional mathematical programming methods. An alternative solution to the conventional approaches. The meta-heuristic optimization tech- niques are used, due to their ability to obtain global or near-global optimum solu- tions. In the present paper, we address the system reliability-redundancy allocation optimization problem, using three well known algorithms namely, the Cuckoo Search (CS), Particle Swarm Optimization (PSO), and the Fractal Search (SFS). The constraints defined here in the problem are handled with the help of the penalty function method. The results of the numerical case study are compared for high- lighting the superiority of an algorithm over another.Item Multi-objective Pipeline Network Reliability Optimization by Particle Swarm Optimization(2019) Chebouba, Billal Nazim; Mellal, Mohamed Arezki; Adjerid, SmailThis paper presents the use of a multi-objective optimization algorithm for solving the reliability allocation problem in case of reliability of pipeline installations in a network configuration. Usually, this kind of problem is considered as a single objective subject to one or several nonlinear constraints and solved by using either mathematical programming techniques or more recently by special metaheuristics. In the present work, the problem is considered as a multi-objective optimization problem. The MOPSO algorithm is used and demonstrates its ability to identify the set of optimal solutions (Pareto front) providing to the decision maker the optimal solution spaceItem Improved Pi-Sigma Neural Network for nonlinear system identification(2017) Ladjouzi, Samir; Grouni, Said; Kacimi, Nora; Soufi, YoucefIn this paper, we propose a modified architecture of a Pi-Sigma Neural Network (PSNN) based on two modifications: extension of the activation function and adding delays to neurons in the hidden layer. These new networks are called respectively Activation Function Extended Pi-Sigma (AFEPS) and Delayed Pi-Sigma (DPS) are obtained first by adding an activation function to all hidden neurons and secondly by modifying the PSNN so its hidden layer outputs are fed to temporal adjustable units that permit to this new network to be capable to identify nonlinear systems. Architecture and dynamic equations of these networks are given in details with their training algorithm. To ensure the effectiveness of our proposed networks, examples of nonlinear system identification are provided. The obtained results show the capacity of HONNs for the nonlinear systems identification. In particular, the proposed neural architectures (AFEPS and DPS) provide better results due to the modifications made on themItem A new training method for solving the XOR problem(2017) Ladjouzi, Samir; Grouni, Said; Kirat, Abderrahmen; Soufi, YoucefTraining of Artificial Neural Networks (ANN) is an important step to make the network able to accomplish the desired task. This capacity of learning in such networks makes them applied in many applications as modeling and control. However, many of training algorithms have some drawbacks like: too many parameters to be estimated, important calculus time. In this paper, we propose a very simple method to train a Single Hidden Layer Perceptron (SHLP) based on replacing the traditional ANN’s phase training by another approach called Neural Least Mean Square (NLMS) problem resolution. The key of this method is to compute some ANN’s weights by the Least Mean Square (LMS) formula, and to leave others weights to their initial values. This new training method is applied to the classical XOR problem and the results are compared with the conventional Backpropagation algorithm. The obtained results were satisfactory and the comparison made with the classical algorithm revealed that our method allowed to reduce several parameters in the learning, namely: the computation time, the overall value of the error squared, the number of iterations and the number of weights to be adjusted