Liste des communications
Effect of Zinc/Cadmium Proportion in the Properties of CdS LayersDeposited by Chemical Bath Depostion Method
Cadmium poisoning and the cost of panel recovery which is very expensive and difficult in the buffer layersof CdS in solar cell, for these two drawbacks, we do a search on the effect of proportion of zinc/cadmium inthe properties layers of CdS. For this, our studies study the properties of CdxZn1-xS layers deposited bychemical bath (CBD). CdZnS thin films were synthesized by chemical bath deposition (CBD) with differentdeposition protocols to optimize deposition parameters such as temperature, deposition time, ionconcentrations and pH. The surface morphology, structural, optical and chemical properties of the CdZnS thinfilms were studied by SEM, XRD, Raman and UV-visible spectrophotometer. The transmittance is 80% inthe visible region 300 nm - 800 nm; the crystalline structure is hexagonal for x ≥ 0.5 and cubic for x≤0.5, thegrain size is between 85.7 and 100 nm. It is observe that the transmittance and the shape change with theconcentration of zinc in the solution; this result favours the application of these films in solar cells application. Voir les détails
Mots clés : CdZnS, chemical bath, SEM, Raman, solar cells, thin films.
Melt Surface Temperature Monitoring In Tiltable Induction Furnace
The supervision of the induction furnace is the subject of increasing development because of the rising demand on reliability and safety. An essential aspect of the pyrometers of induction furnace is the determination of the exact temperature on the melt surface related to the current and frequency flow resulting from optimum coil position depending on the applied actual power. With the aid of the mathematical model that describes the appearance and development of the temperature change in the area of inductive cold wall crucible melting, with the use of the automatic control methods it is possible to determine the change of temperature variation corresponding to direct visualization of a meniscus forms on the melt surface under the energy created by the induction coil, the latter can fully or partly influence the meniscus. To solve the problem of pyrometer temperature variation we propose the determination and the study of the total interaction force related to the operating current of the induction generator. This contribution presents an application for melt temperature change detection through a case study of the tiltable induction furnace with induction generator MFG-20. The study indicates that the pyrometer of the measurement temperature is powerful device related to the development of a new control method. Voir les détails
Mots clés : Tiltable induction Furnace, cold wall crucible melting, pyrometer measurements, Infrared thermography measurement.
A Simple Isoparametric Finite Element Based on the Reddy’s Theory for the Laminated Plates Bending Analysis
The aim of this work is to develop a quadrilateral finite element based on Reddy’s third order shear deformation theory for the bending behavior analysis of composite laminated plates. The element is a C0 four-nodded isoparametric with seven degrees of freedom at each node, three translation components, two rotations and two higher order rotational degrees. In particular, selective numerical integration is introduced in order to improve the results and to alleviate the locking phenomenon. The performance and reliability of the proposed formulation are demonstrated by comparing the author’s results with those obtained using the three-dimensional elasticity theory, analytical solutions and other advanced finite element models. Voir les détails
Mots clés : Ajout mot cléThird Order Shear Deformation Theory, Ajout mot cléLaminated Composite Plates, Ajout mot cléFinite Element, Bending Behavior
DEVELOPMENT AND CHARACTERIZATION OF HYDROXYAPATITE FOR BONE USE
The objective of this work is the elaboration of a biomaterial Hydroxyapatite (Ca10 (PO4)6 (OH)2), by a synthetic method of precipitation, (CaCl2, 2H2O) as source of calcium and (Na2HPO4, 12 H2O) as a source of phosphate. After preparation, the powder was calcined at 900 °C for 90 minutes at a speed of 10 °C / min and compacted into pellets 12 mm in diameter and 2 mm thick. Sintered powder at different temperatures (1000 °C, 1100 °C, 1200 °C, and 1300 °C). In order to study the effect of sintering temperature on the microstructure, the physical and morphological properties of the elaborated hydroxyapatite, the density, the porosity, X-ray diffraction (DRX) and the scanning electron microscopy (SEM) were used for the characterization of the powder. The density decreases with the increase of the porosity, in fact the sample densifies easily when the porosity is lower Voir les détails
Mots clés : hydroxyapatite, SEM, DRX, Porosity, Density
AN EXPERIMENTAL STUDY ON MECHANICAL OF A COMPOSITE MATERIAL FOR ORTHOPEDIC USE
This study consists in the mechanical characterization of a composite material used in the fabrication of orthopedic prostheses by ONAAPH (Annaba- Algeria). The studied composite is the result of a combination of a polymethyl methacrylate (PMMA) resin, fiberglass reinforcements and an absorbent of the resin, namely Perlon. The method adopted for obtaining specimens is the same as that used in the manufacture of prostheses. except that the shape of the mold used in our study is rectangular, allowing to obtain composite plates. The three-point bending tests were carried out on a MTS43 universal machine in the Advanced Materials Research Unit (URMA / CRTI, Annaba/Algeria). The identification of the damage mechanisms according to the mechanical loading conditions as well as the degradation of the constitutive elements, will be discussed. Voir les détails
Mots clés : composite, mechanical tests, mechanical behavior, Finite Elements
Modeling and simulation of In0.15 Ga0.85 N/GaN strainquantum well structure for solar cells application
Quantum well solar cells based on III-V nitride semiconductor materials are a great technological interest by means to their physical and optical properties. In this study the effect of quantum well number on the characteristics (J-V), (P-V) and efficiency for the structure GaN/In 0.15 Ga0.85 N/ GaN was studied. our result showed that, the increase in the number of wells is accompanied by the increase of the light current density and the efficiency, for example with 50 wells we found Jight = 14(mA /cm2) and a efficiency 28%. Voir les détails
Mots clés : Quantum well, solar cell, GaN, InGaN
Analysis and Simulation in Electrical Networks Using SSSC Device for Damping Power Oscillations
A large power system has many interconnections and bulk power transmissions over long distance. As a result, there low frequency inter-zone oscillations which make the system vulnerable to cascade failures. Many different methods have been proposed to alleviate the oscillations in the power system. For many years, Power System Stabilizer (PSS) has been one of the devices traditionally used to dampen oscillations. It is reported that during some operating conditions, PSS may not effectively attenuate oscillations; for this reason, other effective alternatives are required in addition to PSSs. On the other hand, the advent of FACTS has led to a new and more versatile approach to controlling the power system in a desired way. These devices based on very advanced power electronics components (GTO, IGBT,…). FACTS devices according to their network connection are distinguished countervailing series, shunt and hybrid such as: SSSC, ASVC and IPFC, respectively. One of the best-innovated Flexible AC Transmission System devices is the Static Synchronous Series Compensator. The purpose of this paper is to study the control functions provided by the SSSC in controlling the power flow of the load capacity of power lines. Voir les détails
Mots clés : PSS, FACTS, GTO, IGBT, SSSC, ASVC, IPFC
Design of Sobel Filter in VHDL
In order to automate the quality control process of pipe’s welding joint, we present in this paper a new design of an embedded computer vision system, which is based on a camera, controlled by an FPGA platform (Zynq-7000) for acquisition and image processing on the same FPGA circuit. A VHDL implementation of Sobel Edge Detection Algorithm is proposed. The obtained results were validated with those obtained by MATLAB.This will allow us to develop other tools more powerful and more robust. Voir les détails
Mots clés : Quality control, pipe welds, FPGA, Sobel, VHDL
Improving the Power Quality of the Arc WeldingSupply using an Active Power Filter
This paper presents a new circuit topology suitablefor arc welding inverter applications, this topology is based onshunt active power filter (APF), in order to improve the powerquality and reduced the total harmonic distortion (THD) byconsequently improve the power factor (PF), a modified activeand reactive power method (p-q),which is combined with aself-tuning filter, is used to identify the harmonics currentsreferences of the load current, Also a PI controller has beenused to maintain the level of DC-link voltage at a constantvalue and improves its dynamic response; the voltage sourceinverter of APF is controlled by hysteresis current controller.The Major favorable features of this topology like fastresponse to load and source voltage conditions will result inbetter welding performance. The performance of the entiresystem is evaluated on the basis of THD of the source current,input power factor, dynamic response, voltage regulation androbustness to prove its effectiveness in terms of excellent powerquality. Voir les détails
Mots clés : arc welding, Active power filter (APF), power factor (PF), total harmonic distortion (THD), modified active and reactive method (p-q)
Video Processing Software-based Pipeline Endoscopic Inspection
Currently, all the codes and the standards of the fluids transport industries require rigorous pipeline inspection, in order to detect all defects and anomalies and avoid leaks and failures. For this reason, a team within the division of Signal Processing and Imagery had as mission to develop an endoscope which can replace the operator inspection inside the pipeline and improve its quality and diagnostic. This endoscope named 'Pipe Explorer' is controlled by FPGA microcontrollers, and is equipped with a camera. While moving inside the pipe, the camera records a video on the memory card. In this way and in order to offer a practical tool to the operator, we have developed graphical software based on processing techniques of the stored video consisting in video preprocessing and segmentation. At the end of this processing, we obtain a video result on which appears the analysis and the interpretation of the original video to give an internal pipe quality diagnosis. The results shows all the defective areas such as corrosion which are stained with {green, blue, red} color according to its degree of severity and the risk of harmfulness on the inspected pipeline. Voir les détails
Mots clés : Pipeline inspection, endoscopy, video processing, video segmentation, corrosion.