Liste des communications
TWO-STEP ELECTROLESS SYNTHESIS OF A COPPER/SILVERCOMPOSITE FILM FOR ELECTROCATALYTIC OXIDATION OF FORMALDEHYDE
In this work, we report a two-step electroless plating process for preparing a copper/silver composite film on a Resin Epoxy (RE) substrate. First, silver film was deposited on RE substrate from a silvering bath. Then, copper was deposited on silver film at 95 °C from a separate solution containing copper ions and formaldehyde as reducing agent. The electrochemical reactivity of the prepared copper/silver composites was investigated towards the electrochemical oxidation of formaldehyde. Scanning electron microscopy of the composites showed a porous microstructure with uniform surface morphology. The presence of silver and copper onto the RE surface was confirmed by energy dispersive X-ray analysis. The formaldehyde oxidation peak on the copper/silver electrode is obtained at -0.3 V/SCE. The electrode showed a significant electrocatalytic activity with good repeatability and stable electrochemical response. Voir les détails
Mots clés : copper, Electroless deposition, Formaldehyde, Silver, thin film
Edge detection in an infrared image in steeland metallurgical domain
The iron and steel domain has a very important role in the industry. Indeed, much research has been fixed to the product quality, which is an essential factor in the production cycle. Among the most used techniques to today, to inspect the finished product, there is the infrared thermography. This latter allows for detecting defects in materials. Treatments of captured image using an infrared camera can detect the edge of these defects and hence locate them. In this work we try to apply mathematical methods to detect these edges. Voir les détails
Mots clés : Infrared thermography, materials, Defects, edges
Calculation of IGBT power losses and junction temperature in inverter drive
Several techniques for estimating power losses in insulated-gate bipolar transistors (IGBTs), diodes and MOSFETs are known. Most of the approaches in the literature deal with PWM switching technique. In this paper presents a feasible loss model to estimate IGBT losses in a switching operation. The loss model is coupled to RC (Foster) Network using the Thermal Impedance. This paper investigates the power losses in IGBT's and associated Diodes as a function of the circuit and the temperature variation during operation. A full presentation of the electro-thermal model has been developed and simulated. Voir les détails
Mots clés : IGBT, Losses, thermal analysis
Fractional PID controller of MIMO Gas Metal Arc Welding process.
Gas metal arc welding (GMAW) plays the great importance in the welding industry on account of high flexibility in the welding of different metals, high welding productivity, and automatic run capabilities. This paper focuses on the development of a fractional PID control of gas metal arc welding system, wherein the current and voltage of welding process are controlled using a fractional PID controller, then the system analyzed and the results compared with conventional PID controller show adequate improvement in the efficiency and performance of the proposed controller. Voir les détails
Mots clés : GMAW, MIMO system, P ID controller, Fractional PID controller
Etude de soudage TIG d’un alliage d’aluminium 2219 appliqué dans l’aérospatial
Ce travail, présente le soudage TIG de l’alliage d’aluminium A2219 très utilisé dans le domaine aérospatial comme les bacs de stockage du carburant de fusée. Il comprendra une soudure réalisée selon des paramètres de soudage optimisés suivie d’une étude macroscopique, microscopique par microscopie optique(MO) et microscopie électronique à balayage (MEB) ; ce qui nous permet d’identifier les différentes zones et d’évaluer l’évolution microstructurale de l’effet thermique dû à l’apport calorifique du soudage TIG. Des profils de micro dureté sont tracés et déterminent l’état mécanique des différentes zones. Nous constatons une baisse de dureté sur la zone fondue(ZF). Ce résultat est confirmé par une chute brutale de la résistance à la rupture et une diminution de l’allongement de la soudure. Voir les détails
Mots clés : soudage TIG; alliage d’aluminium; A 2219; soudage d’aluminium
Static eccentricity fault modeling in permanent-magnet synchronous motors
In this paper, a model based on the finite element analysis has been developed for healthy and eccentric PMSM. The proposed model is analyzed by time stepping Finite element method. The electromagnetic field distribution, air-gap magnetic flux density and the leakage inductances under healthy and eccentric rotor have been calculated. Meanwhile, the MCSA of the healthy and faulty PMSM is inspected under various static eccentricity levels. Voir les détails
Mots clés : PMSM, Finite Element Method, diagnosis, Static Eccentricity, Spectral analysis
Pipelines Corrosion Due to the Electromagnetic Pollution caused by the High Voltage Power
This paper studies the effect of the electromagnetic pollution caused by the high voltage power lines on the corrosion of the buried pipeline. In this objective, the finite element method (FEM) was used to calculate the magnetic field distribution and the induced current densities in the buried pipeline caused by both horizontal and vertical configuration of the HVPL during steady state conditions. In order to diagnose the effect of the electromagnetic pollution on the corrosion of the pipeline, the electrochemical impedance spectroscopy (EIS) measurements were used to characterize the corrosion polarization properties of X70 steel in simulated soil at various AC current densities. The results show that, the electromagnetic pollution caused by the high voltage power lines affect the electrochemical characteristics of the X70 steel pipeline and accelerate the corrosion of the pipeline. Voir les détails
Mots clés : Electromagnetic pollution, high voltage power line, induced current density, X70 steel pipeline, corrosion, Finite Element Method, electrochemical impedance spectroscopy.
Application of Diagonally Relaxed Orthogonal Projections (DROP)- conjugate gradient and Kaczmarz method for X Rays reconstruction image
In this work, we present the application of algorithms based on algebraic methods, ray tomography image reconstruction X. So DROP algorithms with quadratic regularization (orthogonal projections Relaxes diagonal), conjugate gradient and Kaczmarz will be implemented and applied to real images obtained by an X-ray tomography, a comparative study was made in order to examine the reconstruction algorithms results Voir les détails
Mots clés : DROP method, regularization, Tomography, Kaczmarz method
Numerical Simulation of CdTe thin films solar cells using AMPS
The numerical modeling and simulation is much needed for the realization of thin films solar cells before that device is in fact produced. In this study we have simulated a theoretical configuration based on SnO2/CdS/CdTe/MoTe heterojunction solar cell under AM 1.5 illumination using the Analysis of Microelectronic and Photonic Structures (AMPS-1D) software tool in one dimension. The effect of physical properties variations is well thought-out on the evaluation of performance (VOC, JSC, FF and Efficiency) in CdTe thin films solar cells Voir les détails
Mots clés : AMPS, Numerical simulation, CdTe, Thin-films solar cells
ETUDE ET DÉVELOPPEMENT D’UNE TECHNIQUE DEFILTRAGE BASÉE SUR L’ACPAPPLICATION SUR LES INTERFÉROGRAMMES INSAR
Les interférogrammes dans un processus interférométrique sont souvent bruités, ils présentent desdiscontinuités au niveau des franges ; qui sont due principalement à la décorelation spatiale,temporelle, et thermique, en plus des erreurs de recalage des couples interférométriques. Plusieursméthodes de filtrage ont été développées. Dans ce travail nous sommes particulièrement intéressé auxtechniques de filtrage interférométrique basées sur la décomposition en sous espaces dont nous avonsproposé une méthode de sélection de sous espace optimal afin de conserver l’information physiqueparticulièrement au niveau des zones de transitions des franges. La méthode a été testée sur desinterférogrammes de zones accidentées. Les résultats obtenus sont comparés aux résultats de filtragepar les algorithmes de Goldstein et vecteur Voir les détails
Mots clés : processus interférométrique, interférogrammes, décorrélation spatiale, sous espace optimal, transitions des franges