Qal‘at al Andalus, Tunisia
Qal‘at al Andalus, Tunisia

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Guediche M.,CNRS Tribology and Dynamic Systems Laboratory | Guediche M.,CNRS Contacts and Structural Mechanics Laboratory | Mabrouki T.,CNRS Contacts and Structural Mechanics Laboratory | Mabrouki T.,University of El Manar | And 3 more authors.
Procedia CIRP | Year: 2015

Surface integrity is extremely affected by manufacturing processes conditions especially the evolution of cutting tool performance. Many researchers, in steel machining field, focused their works on the elaboration of models predicting tool wear combining both numerical and experimental approaches. Most of published numerical cutting models simulate the chip formation for a few micro to millisecond time periods. For that, all corresponding experimental tests, needed for the model validation, are usually carried-out in special time conditions which is not reflecting industrial situations. Indeed, the latters are characterized by tool wear whose evolution can affect extremely cutting force levels and the final workpiece integrity. In this context, the main purpose of the proposed research work is to develop a FEM model, based on the commercial code ABAQUS©, to simulate wear phenomenon of tool insert in the case of orthogonal cutting operation. The present research exposes a lagrangian approach simulating the chip formation in the case of AISI 4140 machining. A strategy that aims to reach high machining time simulated with moderate computational time is presented. It is based on ensuring the thermal continuity of the tool from one calculation to another. A considerable gain of calculation time is achieved comparing to the most common models developed on ABAQUS©. © 2015 The Authors. Published by Elsevier B.V.


Ben Nasr I.,University of El Manar | Borgi A.,University of El Manar | Sellem F.,National Institute of Sea science and Technologies
2013 International Conference on Control, Decision and Information Technologies, CoDIT 2013 | Year: 2013

In this paper, we focus on expert knowledge incorporation in supervised learning tasks particularly decision rules. We aim to improve their quality, reduce their number and increase their prediction's rate. The proposed method consists of initially applying Knowledge Discovery in Databases process (KDD) on a database relating to Echinoderms. It aims to improve then classification rules' performance using background knowledge. This method is evaluated on a real domain area concerning Echinoderms. Experimental results are relevant; they generally improve performance and reduce prediction rules number. © 2013 IEEE.


Harouni Z.,University of El Manar | Harouni Z.,University Paris Est Creteil | Cirio L.,University Paris Est Creteil | Osman L.,University of El Manar | And 2 more authors.
IEEE Antennas and Wireless Propagation Letters | Year: 2011

A 2.45-GHz rectifying antenna (rectenna) using a compact dual circularly polarized (DCP) patch antenna with an RFdc power conversion part is presented. The DCP antenna is coupled to a microstrip line by an aperture in the ground plane and includes a bandpass filter for harmonic rejections. It exhibits a measured bandwidth of 2100 MHz (10 dB return loss) and a 705-MHz CP bandwidth (3 dB axial ratio). The maximum efficiency and dc voltage are respectively equal to 63% and 2.82 V over a resistive load of 1600 Ω for a power density of 0.525 mW/cm 2. © 2011 IEEE.


Gamoudi S.,National Center for Research in Materials Science | Frini-Srasra N.,University of El Manar | Srasra E.,National Center for Research in Materials Science
Clay Minerals | Year: 2013

Intercalation of cationic surfactants hexadecylpyridinium (HDPy +) and hexadecyltrimethylammonium (HDTMA+) into the interlayer space of homoionic (Na-, Ca- and Zn-) smectites by solid-solid reactions was investigated. These reactions were complete within 15 min. Changes in the surface and structure of the smectites modified with different surfactants were characterized using XRD, FTIR and DSC. The intercalation of surfactant is controlled by the exchangeable cation of smectite and monofunctional ammonium cation type. HDPy+ and HDTMA+ surfactants were retained by Zn-exchanged smectite, suggesting important surface properties (CEC = 80 meq/100 g clay, SBET = 116.5 m2/g) and acid-base properties (point of zero proton charge PZC, density charge s H). HDPy cation loading was effective, suggesting that the aromatic polar group is favoured for intercalation. Comparing with original clay, modification with surfactants increased the basal spacings d 001. Based on the d 001 spacing of modified smectites, different configurations of surfactants within smectite interlayer were proposed as a function of surfactant concentration, which were examined by FTIR and DSC. © 2013 Mineralogical Society.


Nayli A.,University of Tunis | Guizani S.,University of El Manar | Ammar F.B.,University of Carthage
2015 4th International Conference on Systems and Control, ICSC 2015 | Year: 2015

This study proposes a comparative analysis between the performances of the star windings and open-end stator windings of the synchronous machines with wound rotor without damper windings. The advantages of the openend stator windings at the level of the THD voltage and the torque undulation are presented. It is shown that the novel dual open-end stator windings synchronous machine has significant benefit at the level of the power segmentation is shown. © 2015 IEEE.


Guizani S.,University of El Manar | Nayli A.,University of Tunis | Ben Ammar F.,University of Carthage
Journal of Electrical Engineering | Year: 2014

In this paper the authors propose the degraded mode operation of the open-end stator winding induction machine supplied by two converters on three levels. Each converter is constituted by two three-phase inverters in cascaded. The different conditions that must be respected for the operation mode will be presented.


Gara F.,University of El Manar | Ben Saad L.,University of El Manar | Ben Ayed R.,University of El Manar | Tourancheau B.,Grenoble University
IWCMC 2015 - 11th International Wireless Communications and Mobile Computing Conference | Year: 2015

This paper focuses on wireless sensor networks (WSNs) for healthcare and medical applications which aim to look after patients by monitoring vital signs, diagnostics and drug administrations. WSNs in such applications are usually composed of different types of small-size battery powered sensors. In fact, wearable sensors are used to collect information about the signs of a person that needs a medical care. Static sensors, deployed inside the hospital or the home building, are used to collect information about indoor environment. The collected data is then transmitted towards the sink. Since some patients can move, WSN topology is hybrid and composed of mobile and static nodes. Routing Protocol for Low Power and Lossy Networks (RPL), an IPv6 distance vector routing protocol designed for static wireless sensor network, can be adapted to our need. So in this paper, we propose to modify RPL in order to fit with an hybrid topology. The performance of the modified protocol is evaluated and compared with the existing RPL protocol. The results show that our protocol optimization for healthcare application offers better performance. © 2015 IEEE.


Ben Saad L.,University of El Manar | Tourancheau B.,Joseph Fourier University
2015 7th International Conference on New Technologies, Mobility and Security - Proceedings of NTMS 2015 Conference and Workshops | Year: 2015

Sensor-Cloud is an emerging technology and popular paradigm of choice in systems development for various real-life applications. It consists in integrating wireless sensor networks with cloud computing environment. In fact, the cloud provides new opportunities of massive data storage, processing and analysing that wireless sensor networks can not offer. Despite the fact that the cloud have helped to overcome many wireless sensor networks limitations, there are other challenging issues that need to be addressed. The major problem that can significantly affect Sensor-Cloud performance is the short lifetime due to limited energy supply of sensors and sometimes some sinks. In this work, we propose a Sensor-Cloud Optimization problem (SCL-OPT) that maximizes lifetime as well as increases energy efficiency of sensors and sinks layers. © 2015 IEEE.


Barg S.,University of El Manar | Bennani A.B.A.,University of Carthage
International Multi-Conference on Systems, Signals and Devices, SSD'11 - Summary Proceedings | Year: 2011

This paper deals with the use of coupled inductors for the DC|DC converters. A complete analysis of this topology is carried out and its advantages are demonstrated by comparing it to the DC/DC converter with uncoupled inductor. In this paper, we show how the coupled inductors allow the I 2R losses reduction and the minimization of the phase and the output current ripples. Different architectures and designs of coupled inductors are given. The benefits and the drawbacks of each one are analyzed basing on three criteria: minimization of the harmonic currents, ability to filter the differential currents and the converter volume-weight. Then, simulation results of a medium power DC drive using a coupled inductor converter are given and discussed emphasizing the theoretical results and showing the advantages of the studied topology for this power range. © 2011 IEEE.


Barhoumi Z.,University of El Manar | Saini M.,Kurukshetra University | Amdouni N.,University of El Manar | Pal A.,Kurukshetra University
Chemical Physics Letters | Year: 2016

The micellization of an aqueous solution of the surface active ionic liquid (SAIL), 1-butyl-3-methylimidazolium octylsufate (C4mim)(C8OSO3) and its interaction with an anionic polymer sodium polystyrene sulfonate, (NaPSS) were studied using conductimetry, tensiometry and fluorimetry. Surface tension profile shows a more dramatic increase in the value of surface tension of aqueous (C4mim)(C8OSO3) before the critical micelle concentration (cmc) of IL. The critical micelle concentration (cmc) value of this surfactant was found out from conductance measurements. The thermodynamic parameters, i.e., Gibb's free energy, enthalpy, and entropy of micellization of the IL in aqueous solution have been calculated. Behavior of fluorescence probe confirms the binding interactions between SAIL and the polyelectrolyte. © 2016 Elsevier B.V.

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