Communications Internationales

Permanent URI for this collectionhttps://dspace.univ-boumerdes.dz/handle/123456789/11

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Start date: 2000End date: 2009

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    Students misconceptions about light in Algeria
    (2009) Blizak, Meriem Djanette; Chafiqi, Fouad; Kendil, Djamel
    Physics education research has shown that students have difficulties in learning essential optics concepts. Therefore, in this present work we deal with student’s conceptions in geometrical optics field. Our objective is to show the Algerian students misconceptions. We proposed to 246 students in first year university (aged 18–21) a closed questionnaire where most of its questions were already used by other researchers. The misunderstandings identified were compared with those in literature. The results show that our students have the same misconceptions, related to the propagation of the light, the vision, the refraction and the reflexion, as the students in other countries (Andersson, Çiğdem ŞAHİN, Galili, Goldberg, Viennot,…). We investigate new students “misconception” concerning the propagation of the light in the vacuum
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    Formalisation de la logique de description ALC dans l'assistant de preuve Coq
    (2009) Chaabani, Mohamed; Mezghiche, Mohamed; Strecker, Martin
    Le langage d’ontologie Web (Web Ontology Language OWL) est un langage utilis ́e pour le web s ́emantique. OWL est bas ́e sur les logiques de description (LD), une famille de lan- gages adapt ́es pour la repr ́esentation et le raisonnement sur des connaissances d’un domaine d’application d’une fa ̧con structur ́ee et formelle. Le web s ́emantique est actuellement l’un des champs d’application des m ́ethodes formelles, dont l’objectif est d’assurer leur fiabilit ́e. Un point essentiel de l’application de ces m ́ethodes formelles est la preuve de va- lidit ́e des raisonnements dans des LDs, comme celle de la terminaison, l’ad ́equation (soundness) et la compl ́etude d’un raisonneur. Dans ce papier, on pr ́esente une sp ́ecification formelle de la syntaxe et de la s ́emantique de ALC, qui est consid ́er ́ee comme un repr ́esentant typique d’une large gamme de LDs. On prouve pour cette logique les pro- pri ́et ́es d’ad ́equation, de compl ́etude et de terminaison dans l’assistant de preuve Coq.
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    Contact Resistance Determination For Multi-crystalline Silicon Solar Cells By Using Transmission Line Method (TLM)
    (2008) Tala-Ighil, Razika; Sali, S.; Oussalah, Slimane; Boumaour, Messaoud
    he main objective in solar cells realization consists in increasing their performances. The mechanisms of this increase obey specific phenomena of physics. There is necessarily a contact resistance value behind each value of conversion efficiency. The question is how to quantify the contact resistance and what is its behaviour with different temperature profiles and consequently with the conversion efficiency. This work responds to all of these questions. We have taken square multicrystalline silicon wafers of 10 cm sides. These wafers have followed the traditional process steps i.e.: chemistry, diffusion, silicon nitride PECVD deposition and metallization of the front grid with TLM (Transmission Line Method) mask. The TLM measures are obtained using a test bench which includes a four-point prober and an analyzer. The contact resistance is deduced by the plot of the resistance versus the TLM line distance. It represents the R(D2), R(D3), R(D23), R(D4) and R(D34) where D2, D3, D23, D4 and D34 are the TLM distances. The TLM resistance is the half of the intersection of the slope R(D) with the y-axis. A profile of the evolution of the contact resistance versus the screen printing temperature annealing from 650°C to 800°C for the multi-crystalline silicon solar cells has been obtained.
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    Optical properties of fluorine doped tin oxide annealed under air
    (2006) Tala-Ighil, Razika; Boumaour, Messaoud; Maallemi, A.; Melhani, K.
    Fluorine doped tin oxide thin film was deposited as window layer on diffused mono- crystalline silicon wafers (100) for photovoltaic purposes. At the time of screen printing metallization (1), thin films SnO2: F is confronted to an annealing under air for temperatures beyond 800°C. In order to study the optical properties of this transparent and conductive oxide TCO, thin film SnO2: F is deposited with spray pyrolysis technique on quartz blades to support the annealing of the screen printing metallization at high temperatures. Measured spectra of transmittance and reflectance are obtained by using the characterization by spectrophotometry from the Ultra-Violet to the Near-Infrared range wavelength. One can proceed to the optical parameters calculation by using the numerical and iterative Mueller method (2) to solve the non-linear equations
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    Séparation Des Phases Dans Le Système sio2- B2O3- Na2O (ISBN)
    (2009) Aboutaleb, Djamila; Iratni, A.; Safi, Brahim; Douglad, J.
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    Ferroresonance Avoidance by Distributed Resources Reconfigurationin Islanded Power Grid
    (2009) Boutora, Saliha; Bentarzi, Hamid; OUADI, Abderrahmane
    In a distributed resources power grid,a capacitor bank is used for compensation purposewhen this grid isconnected to the utility. However, when this grid is islanded, thecapacitor bankwill be needed for induction generatoroperation. Ifa great capacitanceis permanently connected, it may causea severe over-voltage due toferroresonance.Inthiswork,a simulationapproachis madeforre selecting an adequate sizeofthiscapacitor thatwill not causethisabnormal phenomenonintheislandedpowergrid. Theobtainedsimulationresultsusing Simulink/MATLABmay beuseful.
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    A New Approach Applied to Adaptive Centralized Load Shedding Scheme
    (2009) Bentarzi, Hamid; OUADI, ABDERRAHMANE; GHOUT, NADIR; Maamri, Farid; MASTORAKIS, NIKOS E.
    One of major contingencies of an electric power system is due to imbalance between loads and generated power. This leads to instability in the power system and hence to a blackout. A load shedding scheme may be used to avoid such problem by reducing the total load. The aim of this work is to develop a new approach applied to an adaptive load shedding scheme using recent development technology such as wide area synchro-phasor measurement. All generator frequencies that may be measured by phasor measurement units are sent to center where a magnitude of disturbance will be calculated. These measured frequencies also will be used to determine the amount of load to be shed as well as the number of shedding steps
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    A new method of oxide charges densities determination using Charge-Pumping technique in MOS structures
    (World Scientific and Engineering Academy and Society, 2008) Bentarzi, Hamid; Zitouni, Abdelkader; Kribes, Youcef
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    Traveling wave antennas optimization using genetic algorithms
    (IEEE, 2008) Recioui, Abdelmadjid; Azrar, Arab; Dehmas, Mokrane; Challal, Mouloud; Bentarzi, Hamid