62 research outputs found

    Electromagnetic Assessment of Submarine Power Cable Degradation Using Finite Element Method and Sensitivity Analysis

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    Submarine power cables used for offshore wind farms electric energy distribution and transmission are subject to numerous threats. Some of the risks are associated with transport, installation and operating in harsh marine environment. This paper describes the feasibility of an electromagnetic low frequency sensing technique for submarine power cable failure prediction. The impact of a structural damage shape and material variability on the induced electric field is evaluated. The analysis is performed by modeling the cable using the finite element method, we use sensitivity analysis in order to identify the main damage characteristics affecting electric field variation. Lastly, we discuss the results obtained

    The reality of practicing academic advising in some Arab and international universities as a model

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    يمثل الارشاد الاكاديمي ركنا أساسيا ومحوريا في ضوء التربية الحديثة حيث يعتبر كأساس مهم في تطوير العملية التعليمية وتحسينها ووضع القرارات لبناء الشخصية المتكاملة القادرة علي مواجهة المستقبل وتحدي الصعاب بما تحمله من متغيرات ومن هذا المنطلق حظي هذا المفهوم باهتمام العديد من العلماء والباحثين ومدراء الجامعات و الأنظمة التعليمية ،والذي اتضح جليا في تجارب بعض الدول العربية والأجنبية وما نتج عنها من تطور وتقدم. ولذا سنركز في هذه المداخلة على العناصر الأساسية المتمثلة في الارشاد والارشاد الأكاديمي وفق العناصر التالية: تعريف الارشاد، تعريف الارشاد الاكاديمي أهداف الارشاد الأكاديمي، أنواع الارشاد الأكاديمي ،أسس الارشاد الأكاديمي، مجالات الارشاد الأكاديمي، مناهج الارشاد الاكاديمي، تجارب بعض الجامعات العربية والأجنبية في الارشاد الأكاديمي ومقترحات لتطوير الارشاد الأكاديمي بالجامعة الجزائرية.Academic counseling is an essential pillar in the light of modern education, where it is considered as an important basis in the development of the educational process and improvement and decision-making to build an integrated personality capable of facing the future and challenge the difficulties with its variables and accordingly this concept has received the attention of many scientists, researchers and university administrators And educational systems, which was evident in the experiences of some Arab and foreign countries and the resulting development and progress. Therefore, in this intervention we will focus on the basic elements of academic Counseling and counseling according to the following elements: Definition of Counseling, definition of academic Counseling Objectives of academic Counseling, types of academic Counseling, the foundations of academic Counseling, areas of academic guidance, academic Counseling curricula, the experiences of some Arab and foreign universities in counseling Academic and proposals for the development of academic Counseling at the Algerian University

    Etude numérique du transfert de chaleur pour un fluide de Bingham dans une cavité carrée en mode de convection naturelle instationnaire

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    Dans ce travail, nous étudions numériquement le transfert de chaleur en mode de convection naturelle instationnaire d'un fluide de Bingham placé dans une cavité carrée. L'influence de plusieurs paramètres sur le comportement thermique à été analysée dans cette étude. Il s'agit du nombre de Bingham, nombre de Rayleigh et nombre de Prandtl. Le présent code de calcul a été validé après confrontation de nos résultats à ceux de Osman Turan (2010) dans le cas de la convection naturelle d'un fluide de Bingham dans une cavité carrée

    Caractérisation de l'écoulement d'un fluide de Bingham dans une cavité à parois mobiles

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    La présente étude numérique traite du transfert thermique en mode de convection forcée, mixte et naturelle, au sein d'une cavité, à parois mobiles, contenant un fluide non newtonien obéissant au modèle rhéologique de Bingham. L'étude concerne l'influence du rapport de forme, du nombre de Bingham ainsi que celle du nombre de Richardson sur le comportement hydrodynamique et thermique de l'écoulement du fluide considéré dans cet espace confiné

    Convection naturelle au sein d'une cavité carrée munie d'une source chauffante placée sur sa paroi inférieure

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    La convection thermique au sein des espaces confinés est devenue, ces dernière années, un sujet d'investigation d'une grande importance, vue sa présence dans différentes applications industrielles telles que le refroidissement des composantes électroniques, les réacteurs nucléaire ainsi les pertes thermiques dans les collecteurs solaires. La présente étude traite de l'analyse numérique de la convection naturelle laminaire au sein d'une cavité carrée dont les parois latérales (en d'autre terme, verticales) sont maintenues à une température constante (froide) alors que les parois horizontales sont isolées thermiquement, à l'exception d'une fraction occupant 20% à 80% de la surface inférieure de l'enceinte et centrée par rapport à celle-ci, qui est maintenue à une température constante et uniforme, supérieure à celle des parois latérales (chaude) et ce, grâce à une source de chaleur placée en contact de cette paroi. La résolution des équations régissant l'écoulement et le transfert thermique est approchée par la méthode des volumes finis, avec des volumes de contrôle quadrilatéraux et un mallaige uniforme. L'algorithme SIMPLER est adopté pour traiter le couplage vitesse-pression et par conséquent, les champs de vitesse et de température. L'étude se focalise sur l'influence occasionnée par les variations du nombre de Rayleigh et de la longueur de la fraction chauffée, sur la structure de l'écoulement et du transfert thermique au sein de la cavité remplie entièrement d'un fluide newtonien incompressible. Les résultats obtenus montrent, entre autres, que le transfert thermique s'intensifie suite à l'augmentation du nombre de Rayleigh et de la longueur de la fraction chauffée de la aproi inférieure et ce, suite à l'augmentation de la surface d'échange entre cette fraction chauffée et le fluide

    A review on MnZn ferrites: Synthesis, characterization and applications

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    About the Oscillatory Flow Phenomenon within 3D Cylindrical Annulus: Critical Buoyancy and Annulus’ Aspect Ratio for Oscillation Stability

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    The main purpose of our investigation is to providethe impact of some pertinent parameters,asthe thermal buoyancy and the geometryratio,on the oscillatory flow’stability of a Newtonian fluid which occurs within an annulus, found between a cold outer circular cylinder and a hot inner one, to come out at the end with critical conditions that couldpredict this phenomenon intosuch an industrial geometry. To do so, aphysical model is developed using the Lattice-Boltzmann approachside by side with the finite difference one. The validity of the latter is ascertained after comparison between our primary predictionsand various experimental & theoretical ones. By usinganunsteady-state regime, both Isotherms and velocity profiles of ourconvective fluidare widely inspected. Going far with its value, the use of a critical aspect ratio could die-out the impact of any investigated parameter on the oscillatoryflow. Then, only a conductive regime will take control intothe annulus. It is tonote that athree dimensions D3Q19model was adopted based on a cubical Lattice

    On the validity of a numerical model predicting heat and mass transfer in porous square cavities with a bottom thermal and solute source: case of pollutants spreading and fuel leaks

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    The present work refers to the study of natural convection into a confined porous medium, driven by cooperating thermal and solutal buoyancy forces. The side walls are maintained at a uniform temperature and concentration, lower than that of a heat and solute source, which located at the center of the bottom wall, the rest of the horizontal walls are kept insulated. The physical model for the momentum conservation equation makes use of the Brinkman extension of the classical Darcy equation, the set of coupled equations is solved using the finite volume method and the SIMPLER algorithm. To account for the effects of the main parameters such the buoyancy ratio, the Lewis and porous thermal Rayleigh numbers, as well as the source length, heat and mass transfer characteristics are widely inspected and then, new powerful correlations are proposed, which predict within ±1% the numerical results. Note that the validity of the used code was ascertained by comparing our results with experimental data and numerical ones already available in the literature

    About the Oscillatory Flow Phenomenon within 3D Cylindrical Annulus: Critical Buoyancy and Annulus’ Aspect Ratio for Oscillation Stability

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    The main purpose of our investigation is to providethe impact of some pertinent parameters,asthe thermal buoyancy and the geometryratio,on the oscillatory flow’stability of a Newtonian fluid which occurs within an annulus, found between a cold outer circular cylinder and a hot inner one, to come out at the end with critical conditions that couldpredict this phenomenon intosuch an industrial geometry. To do so, aphysical model is developed using the Lattice-Boltzmann approachside by side with the finite difference one. The validity of the latter is ascertained after comparison between our primary predictionsand various experimental & theoretical ones. By usinganunsteady-state regime, both Isotherms and velocity profiles of ourconvective fluidare widely inspected. Going far with its value, the use of a critical aspect ratio could die-out the impact of any investigated parameter on the oscillatoryflow. Then, only a conductive regime will take control intothe annulus. It is tonote that athree dimensions D3Q19model was adopted based on a cubical Lattice
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