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Relevance of the P ＆ O MPPT Technique in an Original PV-Powered Water Pumping Application

Journal of Energy and Power Engineering 2015年第11期9卷 1008-1018页

作者： Said Aissou Sebastien Jacques Zahra Mokrani Djamila rekioua toufik rekioua Abdeldjalil Ouahabi Electrical Engineering Department University of Bejaia Bejaia 06000 Algeria Electronics and Energy Department Polytech Tours University ofT ours Tours 37200 France Research Group on Materials Microelectronics Acoustics & Nanotechnology University of Tours Tours 37200 France

Many papers exploiting the various MPPT （maximum power point tracking） techniques in PV （photovoltaic） applications, from the simple to the most complicated, can be found in literature. However, these techniques may not always be easy to implement in industrial applications. The main challenge of this paper is to model and implement the P ＆ O （perturb and observe） algorithm in a low-cost PV-powered pumping system. To that end, a comparative investigation of the performance characteristics of the most popular MPPT methods, such as FOCV （fractional open circuit voltage）, FSCC （fractional short circuit current）, FLC （fuzzy logic control）, ANN （artificial neural network） and INC （incremental conductance） is presented. This analysis is helpful to highlight the relevance of the P ＆ O technique taking better account of complexity, difficulty of implementation and cost considerations in water pumping applications. The targeted PV-powered pumping system is based on a single-phase induction motor supplied by a three-phase inverter controlled by the DTC （direct torque control） technique. This stand-alone PV system is dedicated to water pumping, especially in rural areas that have no access to national grids but have sufficient amount of solar radiation. Simulation modeling （Matlab/Simulink） and experimental results are presented to demonstrate the relevance of the system.

关键词： DC-DC power converter MPPT algorithms P & O stand-alone PV-powered water pumping system.

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Stagnation temperature effect on the conical shock with application for air

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Chinese Journal of Aeronautics 2018年第4期31卷 672-697页

作者： toufik ELAICHI toufik ZEBBICHE Aeronautical Sciences Laboratory Institute of Aeronautics and Space Studies University SAAD Dahlab of Blida 1B.P.270

The aim of this work is to realize a new numerical program based on the development of a mathematical model allowing determining the parameters of the supersonic flow through a conical shock under hypothesis at high temperature, in the context of correcting the perfect gas model. In this case, the specific heat at constant pressure does not remain constant and varies with the increase of temperature. The stagnation temperature becomes an important parameter in the *** mathematical model is presented by the numerical resolution of a system of first-order nonlinear differential equations with three coupled unknowns for initial conditions. The numerical resolution is made by adapting the higher order Runge Kutta method. The parameters through the conical shock can be determined by considering a new model of an oblique shock at high temperature. All isentropic parameters of after the shock flow depend on the deviation of the flow from the transverse direction. The comparison of the results is done with the perfect gas model for low stagnation temperatures, upstream Mach number and cone deviation angle. A calculation of the error is made between our high temperature model and the perfect gas model. The application is made for air.

关键词： Calorically imperfect gas Conical shock High temperature Numerical integration Oblique shock Perfect gas model Runge Kutta method Supersonic flow

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Effect of Stagnation Temperature on the Supersonic Two-Dimensional Plug Nozzle Conception. Application for Air

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Chinese Journal of Aeronautics 2007年第1期20卷 15-28页

作者： toufik Zebbiche ZineEddine Youbi Department of Aeronautics Faculty of Sciences of Engineer University SAAD Dahleb of Blida B.P. 270 Ouled Yaich 09470 Blida Algeria

When the stagnation temperature of a perfect gas increases, the specific heats and their ratio do not remain constant any more and start to vary with this temperature. The gas remains perfect, its state equation remains always valid, except it will name in more calorically imperfect gas or gas at High Temperature. The goal of this research is to trace the profiles of the supersonic plug nozzle when this stagnation temperature is taken into account, lower than the threshold of dissociation of the molecules, by using the new formula of the Prandtl Meyer function, and to have for each exit Mach number, several nozzles shapes by changing the value of this temperature. A study on the error given by the PG （perfect gas） model compared to our model at high temperature is presented. The comparison is made with the case of a calorically perfect gas aiming to give a limit of application of this model. The application is for the air.

关键词： supersonic flow plug nozzle calorically imperfect gas interpolation Prandtl Meyer functiom stretching fimction Simpson quadrature, supersonic parameters conception.

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Supersonic Two-Dimensional Minimum Length Nozzle Design at High Temperature. Application for Air

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Chinese Journal of Aeronautics 2007年第1期20卷 29-39页

作者： toufik Zebbiche ZineEddine Youbi Department of Aeronautics Faculty of Sciences of Engineer University SAAD Dahleb of Blida B.P. 270 Ouled Yaich 09470 Blida Algeria.

When the stagnation temperature of a perfect gas increases, the specific heat ratio does not remain constant any more, and start to vary with this temperature. The gas remains perfect, its state equation remains always valid, except it will name in more calorically imperfect gas or gas at High Temperature. The goal of this work is to trace the profiles of the supersonic Minimum Length Nozzle with centered expansion when the stagnation temperature is taken into account, lower than the threshold of dissociation of the molecules and to have for each exit Mach number several nozzles shapes by changing the value of the temperature. The method of characteristics is used with a new form of the Prandtl Meyer function at high temperature. The resolution of the obtained equations is done by the second order of fmite differences method by using the predictor corrector algorithm. A study on the error given by the perfect gas model compared to our model is presented. The comparison is made with a calorically perfect gas for goal to give a limit of application of this model. The application is for the air.

关键词： supersonic flow minimum length nozzle calorically imperfect gas interpolation Prandtl Meyer function stretching function Simpson quadrature supersonic parameters conception method of characteristics

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Delivering audiovisual content with MPEG-21-enabled cross-layer QoS adaptation

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第5期7卷 784-793页

作者： AHMED toufik DJAMA Ismail CNRS-LaBRI Laboratory University of Bordeaux-1.351 Cours de la Libération Talence F-33405 France

Future multimedia communication systems have to support the user’s needs, the terminal capabilities, the content specification and the underlying networking technologies. The related protocols and applications must be designed from this integration perspective in a cross-layer centric manner. In this paper, we propose an implementation of a streaming service (e.g., Television over IP service) with a unified QoS management concept that enables an IP driven integration of different system components (terminal, user, content, and network). The MPEG-21 framework is used to provide a common support for imple- menting and managing the end-to-end QoS. The main focus of this paper is on the architecture design, protocols specification and implementation evaluation. Performance evaluations using PSNR and SSIM objective video quality metrics show the benefit of the proposed MPEG-21-enabled cross-layer adaptation.

关键词： Cross-layer adaptation, MPEG-21 multimedia framework, Real-time streaming, QoS

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Unsteady Heat Transfer in Bilayer,and Three-Layer Materials

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Fluid Dynamics & Materials Processing 2023年第4期19卷 977-990页

作者： toufik Sahabi Smain Balaska Physics Department Faculty of SciencesUniversity of Saida Dr.Moulay TaharSaida20000Algeria Theoretical Physics Laboratory University of Oran-1-Ahmed Ben BellaOran31000Algeria

The heat transfer equation is used to determine the heat flow by conduction through a composite material along the real *** analytical dimensionless analysis is implemented in the framework of a separation of variables method(SVM).This approach leads to an Eigenvalues problem that is solved by the Newton’s *** types of dynamics are found:An unsteady condition(in the form of jumps or drops in temperatures depending on the considered case),and a permanent equilibrium(tending to the ambient temperature).The validity and effectiveness of the proposed approach for any number of adjacent layers is also *** is shown that,as expected,the diffusion of the temperature is linked to the ratio of the thermo-physical properties of the considered layers and their number.

关键词： Heat transfer conduction eigen values composite materials thermo-physical properties

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New Online DV-Hop Algorithm via Mobile Anchor for Wireless Sensor Network Localization

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Tsinghua Science and Technology 2023年第5期28卷 940-951页

作者： Oumaima Liouane Smain Femmam toufik Bakir Abdessalem Ben Abdelali EμE Laboratory University of MonastirMonastir 5000Tunisia Department of Networks and Communications University of Haute-AlsaceMulhouse 68100France ImViA Laboratory University of Burgundy Franche-ComtéDijon 21078France

In many applications of Wireless Sensor Networks(WSNs),event detection is the main purpose of ***,determining where and when that event occurs is crucial;thus,the positions of nodes must be ***,in a range-free case,the Distance Vector-Hop(DV-Hop)heuristic is the commonly used localization algorithm because of its simplicity and low *** DV-Hop algorithm consists of a set of reference nodes,namely,anchors,to periodically broadcast their current positions and assist nearby unknown nodes during *** potential solution includes the use of only one mobile anchor instead of these sets of *** solution presents a new challenge in the localization of rang-free WSNs because of its favorable results and reduced *** this paper,we propose an analytical probabilistic model for multi-hop distance estimation between mobile anchor nodes and unknown *** derive a non-linear analytic function that provides the relation between the hop counts and distance ***,based on the recursive least square algorithm,we present a new formulation of the original DV-Hop localization algorithm,namely,online DV-Hop localization,in ***,different scenarios of path planning and simulation results are conducted.

关键词： Wireless Sensor Networks(WSNs) mobile anchor online localization path planning

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Continuous analyticⅠ-Ⅴmodel for GS DG MOSFETs including hot-carrier degradation effects

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Journal of Semiconductors 2012年第1期33卷 41-46页

作者： toufik Bentrcia Faycal Djeffal Abdel Hamid Benhaya Department of Physics University of Batna Batna 05000Algeria LEA Department of Electronics University of BatnaBatna 05000Algeria

We have studied the influence of hot-carrier degradation effects on the drain current of a gate-stack double-gate （GS DG） MOSFET device. Our analysis is carried out by using an accurate continuous current-voltage （I-V） model, derived based on both Poisson＇s and continuity equations without the need of charge-sheet approxi- mation. The developed model offers the possibility to describe the entire range of different regions （subthreshold, linear and saturation） through a unique continuous expression. Therefore, the proposed approach can bring consid- erable enhancement at the level of multi-gate compact modeling including hot-carrier degradation effects.

关键词： GS DG MOSFET hot-carriers degradation effects compact modeling piece-wise models

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Several variants of the Dumont differential system and permutation statistics

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Science China Mathematics 2019年第10期62卷 2033-2052页

作者： Shi-Mei Ma toufik Mansour David GLWang Yeong-Nan Yeh School of Mathematics and Statistics Northeastern University at QinhuangdaoQinhuangdao066000 Department of Mathematics University of HaifaHaifa3498838 School of Mathematics and Statistics Beijing Institute of TechnologyBeijing102488 Institute of Mathematics Academia SinicaTaipei10617

The Dumont differential system on the Jacobi elliptic functions was introduced by Dumont(1979)and was extensively studied by Dumont, Viennot, Flajolet and so on. In this paper, we first present a labeling scheme for the cycle structure of permutations. We then introduce two types of Jacobi pairs of differential equations. We present a general method to derive the solutions of these differential equations. As applications,we present some characterizations for several permutation statistics.

关键词： Jacobi elliptic functions Dumont differential system permutation statistics context-free grammars

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H2 sensing properties of modified silicon nanowires

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Progress in Natural Science:Materials International 2015年第2期25卷 101-110页

作者： Latefa Baba Ahmed Sabrina Naama Aissa Keffous Abdelkader Hassein-Bey toufik Hadjersi Département de physique Université Saad Dahlab de Blidaroute de Soumaa B.P. 270Blida 09000 Algeria Centre de Recherche en Technologie des Semi-conducteurs pour l’Energétique (CRTSE) 2Bd.Frantz FanonB.P. 140 Alger-7 MerveillesAlgerAlgeria

It has been found that the silicon nanowires modified with noble metals can be used to fabricate an effective H2 gas sensor in the present *** preparation and surface modification of silicon nanowires(Si NWs) were carried out by chemical methods. The morphology of the silicon nanowires unmodified and modified with nanoparticles of platinum, palladium, silver and gold was investigated using scanning electron microscopy(SEM). The chemical composition of the silicon nanowire layers was studied by secondary ion mass spectroscopy(SIMS) and energy dispersive X-ray analysis(EDX). The structures of type metal/Si NWs/p-Si/Al were fabricated. The electrical characterization(I–V) was performed in primary vacuum and H2 at different concentrations. It was found that the metal type used to modify the Si NWs strongly influenced the I–V characteristics. The response of these structures toward H2 gas was studied as a function of the metal type. Finally, the sensing characteristics and performance of the sensors were investigated.

关键词： Electroless chemical etching Noble metal H2sensor Silicon nanowires Morphology

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