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Thermal analysis of aging of a matrix polymer material reinforced with a glass fiber.

Nacira SASSANE, Latifa ALIMI, Tahar GUETTAFTEMAM, Mohamed Hassani, Skander Boukhezar, Nour Eddine BOUGHDIR, Nihel HAMZAOUI  (2019)
Article de conférence

The objective of this work is to evaluate the influence of temperature variation on the oxidation induction time of a fiberglass-reinforced polymeric matrix material for prosthesis of a tibia.To do this, we used the differential scanning calorimetry (DSC) technique to calculate the oxidation induction time this last one is the time needed to start the oxidation of the material in an oxygenated environment with an isotherm. And thanks to which we could determine the variation of an isotherm for different temperatures as a function of time.The experimental results obtained show that the time required to start the oxidation of the material in an oxygenated environment with an isotherm (OIT) decreases with the increase of the temperature of the sample this is confirmed by a hardness test. Voir les détails

Mots clés : thermal analysis, Polymer material, Oxidation induction time (OIT), hardness test

A Study of the Behavior of Water Droplets Under The Influence of Non-Uniform Electric Field in Silicon Rubber

S.Benharat, S.Bouazabia, A. Haddad  (2017)
Article de conférence

Water droplets on the surface of silicon rubberwere investigated under the influence of non-uniform electricfields. Several parameters of water droplets were investigated,such as the positioning of the droplets regarding the electrodes.The most striking conclusion is that the flashover voltage andelectric field distribution depends on the positioning of thedroplets from the electrodes. Voir les détails

Mots clés : water droplets, non uniform Electric field, COMSOL, finite element, insulating barrier, silicon rubber

Behaviour of the electric arc for different times and for different values of welding currents

S.Benharat, A.Boutaghane  (2016)
Article de conférence

Welding is a permanent joiningprocess used to join different materials like metals, alloysor plastics, togetherat their contacting surfacesby application of heat and or pressure. The study of welding processes currently appears as an area of research both open and complex because it requires to share of knowledge in different fields of physics and mechanics.Thus, the description of one of the most commonly used processes,the arc welding, involves physical phenomena as varied as the study of plasmas, magnetic and hydrodynamic interactions, the description and quantification of heat transfer, etc. The aim of our work is the treatment of the influence of welding time and welding current on the form of the arc, voltage and current density in the GTWA process. For this, we realize a numerical study to determine the arc forms, the voltage and the current density, in which we use the finite element method for the calculation, using Comsol software. The Main results obtained are: 1-The arc shape and evolution of isothermal change with increasing weld time.2-The distribution of the voltage and the current density between the torch and the plate weld obtained by simulation are the same with the results presented in the literature. Voir les détails

Mots clés : arc welding, GTAW process, welding current, modeling, Finite elements method, COMSOL Multiphysics

Répartition de champ électrique dans un système pointe-plan avec barrière isolante

BENHARAT Samira, Slimane Bouazabia  (2015)
Article de conférence

The objective of our work is the study by numerical simulation of the distribution of the electric field according to geometric measurements of the insulating barrier and its position in the inter-electrodes gap Voir les détails

Mots clés : Electrical discharge, insulating barrier, finite element, electrical field

Structural and tribological behavior of AISI L6 tool stee

Oualid GHELLOUDJ, Amel GHARBI, Djamel Zelmati, Sihem ACHOURI, Mounira Bourebia, Chems Eddine RAMOUL  (2018)
Article de conférence

Tool steels constitute a family of carbon steels and alloy steels that are characterized by good wear resistance. These steels are destined for manufacture of tools used for forming, cutting and machining operations of metals and alloys. Among these steels, AISI L6 Tool steel alloy with nickel, chromium, molybdenum and vanadium for hot work, it is used in applications of punches, trim dies, blanking dies, embossing dies, forming dies, and shear blades. The aim of this work is to study the tribological behavior of AISI L6 steel before and after a hardening treatment at 780 °C. Structural characterization and tribological behavior of steel were investigated using Optical Microscopy (OM) and wear testing by friction on a Ball/Pin-on-disc Tribometer. The results obtained show a decrease in coefficient of friction due to improvement of wear resistance of AISI L6 steel by hardening treatment. This improvement is favored by precipitation of very hard particles offering a better resistance to displacement of dislocations. Voir les détails

Mots clés : tribology, wear, heat treatment, hardening, structure, AISI L6

Caractérisation des couches mincespar les techniques optiques.

A. Boughelout, A. Hammouda, L. CHABANE, N. ZEBBAR et M. KECHOUANE.  (2014)
Article de conférence

Dans ce travail nous avons utilisé des techniquesoptiques et structurales pour caractériser des couches minces deZnO déposées par pulvérisation cathodique sur des substrats deverre corning et silicium monocristallin. Nous avons utilisé laspectroscopie Raman pour analyser le type de la structure descouches mince (ZnO) élaborées ainsi que la diffraction des rayonsX.Les caractérisations optiques comportent le relevé destransmittances dans l’UV-Visible et les paramètres optiques telque les indices de réfraction des couches et leurs épaisseurs, lesmesures de la photoluminescence pour déduire le gap des coucheset les niveaux des défauts dans le matériau.Les caractérisations structurales (diffraction des rayons X etRaman) mettent en évidence une structure hexagonale würtzitede ZnO, Les mesures de transmission optique des couchesmontrent que la transmission optique est très élevée (facteur detransmission) dans la gamme de longueurs d’ondes situées entre 400nm et 2500 nm. Voir les détails

Mots clés : pulvérisation réactive, oxyde de zinc, propriétés optiques, caractérisation structurale, conductivité électrique.

LES PROPRIETES OPTIQUES ET ELECTRIQUES DES COUCHES MINCES DE ZnO DEPOSEES PAR PULVERISATION CATHODIQUE A BASSE PRESSION.

A. Boughelout, A. Bensouilah, L. CHABANE, N. ZEBBAR, A. HAMMOUDA et M. KECHOUANE.  (2014)
Article de conférence

Les propriétés des couches minces de l’oxyde de zinc (ZnO) (optiques, électriques) déposées par pulvérisation (DC) dépendent fortement des conditions de dépôt comme la composition de phase du gaz, les conditions de plasma et la température de dépôt. Des couches minces de ZnO ont été déposées par pulvérisation (DC) d'une cible métallique de Zinc en utilisant un plasma d’un mélange de gaz (argon, oxygène) avec une pressions totale ne dépasse pas 1 mbar et à une température de 100 ° C. Ces couches sont caractérisées par la transmission optique UV visible, mesures de conductivité électrique, mesures Raman. Les mesures de transmission optique des couches montrent que la transmission optique est très élevée (facteur de transmission) dans la gamme de longueurs d’ondes située entre 400nm et 2500 nm et elle variée en fonction des conditions d’élaboration comme est présenté sur la figure 2a. Les mesures électriques I-V et I-T mettent en évidence l’effet de la pression dans la chambre de dépôt sur la conductivité et l’énergie d’activation des couches élaborées. Voir les détails

Mots clés : pulvérisation réactive, oxyde de zinc, propriétés optiques, caractérisation structurale, conductivité électrique.

ELABORATION AND CHARACTERIZATION OF ZnO THIN FILMS DEPOSITED BY DC SPUTTERING AT LOW PRESSURE AND LOW TEMPERATURE:APPLICATION TO PHOTOVOLTAIC AND GAS SENSOR

A. Boughelout, A. Bensouilah, L. CHABANE, N. ZEBBAR, A. HAMMOUDA et M. KECHOUANE.  (2014)
Article de conférence

DC reactive sputtering was used to deposit Zinc oxide (ZnO) films onto corning glass and crystalline silicon substrates at both room temperature and 100°C with an argon/oxygen mixture at sputtering pressure varying from 10 to 70 Pa. The dependence of films properties including structure, microstructure as well as optical on deposition parameters (deposition temperature and sputtering pressure) are investigated. The ZnO thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), optical transmission, electrical conductivity measurements. All ZnO films exhibit an intensive (002) XRD peak, indicating that the films are highly texturized along the c-axis perpendicular to the substrate surface. It is found that the nature of the annealing atmosphere has a great influence on the ZnO film composition. Furthermore, thermal annealing at 300°C have the effects of narrowing the diffraction peak and shifting the (002) peaks to higher 2θ angles, which indicates that grain growth has occurred. The transmission measurements have shown that all films exhibit high transmittance in the 400–2500 nm range. Post-deposition annealing influences the morphological, optical and electrical properties of ZnO films. A very large increase in electrical conductivity, up to nine orders of magnitude, was observed in as-grown ZnO films upon vacuum-annealing at 300°C for one hour, reaching as high as 10 ?-1.cm-1. Voir les détails

Mots clés : reactive sputtering, transparent conducting zinc oxide, optical properties, structural characterization, electrical conductivity.

L’influence de la pression des gazes dans un plasma de la pulvérisant cathodique DC sur les propriétés des couches minces de ZnO.

A. Boughelout, A. Bensouilah, L. CHABANE, N. ZEBBAR, A. HAMMOUDA et M. KECHOUANE.  (2013)
Article de conférence

Des couches minces de ZnO ont été déposées par pulvérisation (DC) d'une cible métallique de Zinc, en utilisant un plasma d’un mélange de gaz (argon, oxygène) avec des pressions variantes de l’Oxygène et à une température de 100 °C. Ces couches sont caractérisées par la transmission optique UV visible et les mesures de conductivité électrique. Les mesures de transmission optique des couches montrent que la transmission optique est très élevée (facteur de transmission) dans la gamme de longueurs d’ondes située entre 400 nm et 2500 nm et elle variée en fonction de la pression d’oxygène. Les mesures électriques I-V et I-T mettent en évidence l’effet de la pression d’oxygène dans le plasma sur la conductivité et l’énergie d’activation des couches élaborées. Voir les détails

Mots clés : pulvérisation réactive, oxyde de zinc, propriétés optiques, caractérisation structurale, conductivité électrique.

Synthesis and characterization of nickel nanoparticles supported on aluminum oxide

D.BELFENNACHE, A.Boulegane, D.Lakhdari, N.KAGHOUCHE  (2019)
Article de conférence

Due to their peculiar qualities, metal-based nanostructures have been extensively used in applications such as catalysis, electronics, photography, and information storage, among others. New applications for metals in areas such as photonics, sensing, imaging, and medicine are also being developed. Significantly, most of these applications require the use of metals in the form of nanostructures with specific controlled properties. The properties of nanoscale metals are determined by a set of physical parameters that include size, shape, composition, and structure. In recent years, many research fields have focused on the synthesis of nanoscale-sized metallic materials with complex shape and composition in order to optimize the optical and electrical response of devices containing metallic nanostructures. In This work, we study nickel nanoparticles supported on aluminum oxide, prepared by impregnation with ionic exchange. In a first stage, the fixing conditions of the nickel precursor on aluminum oxide are optimized. In the second stage, the samples are calcined at temperature (T= 750 °C). Several experimental techniques are used for the characterization of the samples at the various stages of their elaboration (SEM, DRX, and VSM). A change of morphology of the aluminum oxide grains was observed by Scanning Electron Microscope. The X-rays diffraction shows the formations of nanoparticles Al3Ni2 of near size 16.7 nm. The extracted magnetic measurements show the good and the easy magnetization Voir les détails

Mots clés : nanostructures, Ionic exchange, Nickel nanoparticles, calcination