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Super twisting sliding mode approach applied to voltage orientated control of a stand-alone induction generator

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Protection and Control of Modern Power Systems 2021年第1期6卷 233-241页

作者： Yacine Bendjeddou Abdelhakim Deboucha Larafi Bentouhami elkheir Merabet rachid Abdessemed Laboratory of electrical and materials engineering(LGEM) Higher School of Electrical and Energetic Engineering of Oran31000Bir El DjirAlgeria Ecole Supérieure des Sciences Appliquées d’Alger Electrical Engineering Department16000AlgiersAlgeria Department of electromechanical University of Bordj Bou Arréridj34000El AnceurAlgeria Laboratory LEB Department of Electrical EngineeringUniversity of Batna-205000FesdisAlgeria

To enhance the robustness and dynamic performance of a self-excited induction generator (SEIG) used in a stand-alone wind energy system (WES), a virtual flux oriented control (VFOC) based on nonlinear super-twisting sliding mode control (STSMC) is adopted. STSMC is used to replace the conventional proportional-integral-Fuzzy Logic Controller (PI-FLC) of the inner current control loops. The combination of the proposed control strategy with space vector modulation (SVM) applied to a PWM rectifier brings many advantages such as reduction in harmonics, and precise and rapid tracking of the references. The performance of the proposed control technique (STSMC-VFOC-SVM) is verified through simulations and compared with the traditional technique (PI-FLC-VFOC-SVM). It shows that the proposed method improves the dynamics of the system with reduced current harmonics. In addition, the use of a virtual flux estimator instead of a phase-locked loop (PLL) eliminates the line voltage sensors and thus increases the reliability of the system.

关键词： Self-excited induction generator Virtual flux oriented control Back-to-back converter Super twisting sliding mode control PI-fuzzy controller wind energy

electrocardiogram Signal Denoising Using Discrete Wavelet Transform

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Computer Technology and Application 2014年第2期5卷 98-104页

作者： Mustapha el HANINE elhassane ABDelMOUNIM rachid HADDADI Abdelaziz BelAGUID Faculty of Science and Technology University of Hassan I Settat 26000 Morocco Faculty of Medicine andPharmacy University of Mohamed V Rabat 10000 Morocco

The most common noises in ECG （electrocardiogram） signal processing are BW （baseline wandering） and the 50 or 60 Hz PLI （power line interferences）. In order to remove these two major source of noises, we have used the recent powerful DWT （discrete wavelet transform） signal processing in ECG signals which are obtained from MIT-BIH Arrhythmia Database. The results indicate that DWT is a good method for filtering noises without changing the morphology of ECG, and can be applied to all types of ECG signals, whether normal or presenting arrhythmias.

关键词： ECG Signal processing 60 Hz PLI baseline wander DWT.

Contribution to Development of Reliability and Optimization Methods Applied to Mechanical Structures

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Applied Mathematics 2013年第1期4卷 19-24页

作者： Siham Ouhimmou Abdelkhalak el Hami rachid ellaia Mohamed Tkiouat Laboratory of Mechanics of Rouen National Institute of Applied Sciences Rouen France Laboratory of Mechanics University Hassan II Casablanca Morocco Laboratory of Study and Research in Mathematics Applied Mohammedia School of Laboratory of Study and Research in Mathematics Applied Mohammedia School of Engineers Agdal-Rabat Morocco

In order to take into account the uncertainties linked to the variables in the evaluation of the statistical properties of structural response, a reliability approach with probabilistic aspect was considered. This is called the Probabilistic Transformation Method (PTM). This method is readily applicable when the function between the input and the output of the system is explicit. However, the situation is much more involved when it is necessary to perform the evaluation of implicit function between the input and the output of the system through numerical models. In this work, we propose a technique that combines Finite element Analysis (FEA) and Probabilistic Transformation Method (PTM) to evaluate the Probability Density Function (PDF) of response where the function between the input and the output of the system is implicit. This technique is based on the numerical simulations of the Finite element Analysis (FEA) and the Probabilistic Transformation Method (PTM) using an interface between Finite element software and Matlab. Some problems of structures are treated in order to prove the applicability of the proposed technique. Moreover, the obtained results are compared to those obtained by the reference method of Monte Carlo. A second aim of this work is to develop an algorithm of global optimization using the local method SQP, because of its effectiveness and its rapidity of convergence. For this reason, we have combined the method SQP with the Multi start method. This developed algorithm is tested on test functions comparing with other methods such as the method of Particle Swarm Optimization (PSO). In order to test the applicability of the proposed approach, a structure is optimized under reliability constraints.

关键词： Reliability Methods Probabilistic Transformation Method Finite element Analysis FEACPTM The Method SQP The Multi Start Method Algorithm MSQP Structural Optimization

Micropulse diode laser therapy in refractory glaucoma

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Advances in Ophthalmology Practice and Research 2023年第1期3卷 23-28页

作者： Moctar Issiaka Khalil Zrikem Adil Mchachi Leila Benhmidoune Rayad rachid Mohamed el.Belhadji Abdoul Salam Youssoufou Souley Abdou Amza Faculty of Medicine and Pharmacy Hassan II University of CasablancaCasablancaMorocco Adult Ophthalmology Department 20 August 1953 HospitalIbn Rochd University Hospital of CasablancaCasablancaMorocco Ophthalmology Department of the Amirou Boubacar Diallo National Hospital NiameyNiger

Purpose:Description of safety and efficacy of micropulse lYanssderal cydophotocoagulation as a treatment option for refractory ***:This is a prospective study including 39 eyes of 31 patients foil owed for refractory glaucoma,who benefited from transsderal cyclophotocoagulation using a mic topi used *** main indication for tire procedure was increased ocular pressure refractory to quadri therapy in various types of *** patients were tieated using iridex Cyclo G6 laser with a Micropulse P3 infrared probe with a wavelength of 810 *** parameter for tire procedure were a duration of 90 s per hemisphere with a power of 2000 mW and an eneigy of 180 *** tire upper and lower hemispheres were treated in tire same procedure,sparing tire 3 o'clock and 9 o'clock meridians,and aD tire patients benefited from a single treatment *** following parameters were evaluated;ocular pain and overall tolerance;visual acuity;and tire evolution of IOP postoperatively up to 9 ***:The glaucoma subtypes treated are as follows:primaty open-angle glaucoma(n=05),chronic angle-closure glaucoma(n=13),neovascular glaucoma(n=07),aphakic glaucoma(n=06),malignant glaucoma(n=04),post-traumatic angle recession(n=02),and inflammatoiy glaucoma(n=02).The mean pre-operative intraocular pressure was 42.3±5.2 mmHg and tire mean post operative intraocular pressure at 9 months was 16.9±1.9 mmHg The reduction in IOP was 49.9%.The average number of intraocular pressure-lowering medications used prior to surgery was four,and tire average number of medications used at tire 9-month postoperative visit was 2.0±1.2(703%of patients were on dual therapy).The overall success rate was 60.9%.Conclusions:Micropulse transsderal cydophotocoagulation appears to be a safe and effident treatment for refractory *** indications should therefore be broadened and proposed early in various situations.

关键词： Micropulse laser Transscleral cyclophotocoagulation Refractory glaucoma Intraocular pressure

Wideband Reconfigurable Millimeter-Wave Linear Array Antenna Using Liquid Crystal for 5G Networks

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Wireless Engineering and Technology 2021年第1期12卷 1-14页

作者： Ali el Hajj Hassan Najib Fadlallah Mohammad Rammal Georges Zakka el Nashef elias rachid Ecole Doctorale des Sciences et de la Technologie (EDST) Lebanese University (LU) Beirut Lebanon Ecole Supérieure d’Ingénieurs de Beyrouth (ESIB) Université Saint-Joseph (USJ) Beirut Lebanon

The advanced design of a 10 × 1 linear antenna array system with the capa-bility of frequency tunability using GT3-23001 liquid crystal (LC) is pro-posed. The design for this reconfigurable wideband antenna array for 5G ap-plications at Ka-band millimeter-wave (mmw) consists of a double layer of stacked patch antenna with aperture coupled feeding. The bias voltage over LC varies from 0 V to 10.6 V to achieve a frequency tunability of 1.18 GHz. The array operates from 25.3 GHz to 33.8 GHz with a peak gain of 19.2 dB and a beamwidth of 5.2° at 30 GHz. The proposed reconfigurable antenna ar-ray represents a real and efficient solution for the recent and future mmw 5G networks. The proposed antenna is suitable for 5G base stations in stadiums, malls and convention centers. It is proper for satellite communications and radars at mmw.

关键词： 5G Networks Liquid Antenna Liquid Crystal Frequency Reconfigurability Antenna Array Millimeter-Wave

Accumulation of Copper, Lead, Chrome, Cadmium in Some Tissues of <i>Procambarus clarkii</i>in Rharb Region in Morocco

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Journal of Geoscience and Environment Protection 2015年第8期3卷 74-81页

作者： Ikram el Qoraychy Mohamed Fekhaoui Abdellah el Abidi rachid Benakame Abdelkbir Bellaouchou Ahmed Yahyaoui Laboratory of Zoology and General Biology Faculty of Science Mohammed V University Rabat Morocco Scientific Institute Mohammed V University Rabat Morocco National Institute of Hygiene Rabat Morocco

Different concentrations of four metals namely copper, lead, chrome and cadmium were evaluated in crayfish Procambarus clarkii tissues (carapace, flesh) for a six-month period, from March to August 2013 in the Rharb of Morocco (Lagoon Merja Zerga and Nador canal). The determination of heavy metals was carried using atomic absorption spectroscopy Varian VV20. The results obtained revealed a metal’s contamination of Procambarus clarkii in both sites. Concentrations of heavy metals examined Procambarus clarkii carapace ranged as follows: Merja Zerga (Pb 2.07 - 6.7 μg/g;Cu 2.9 - 9.97 μg/g;Cr 0.89 - 14.22 μg/g dry weight) and Nador canal: (Pb 0.08 - 7.8 μg/g;Cu 3.40 - 9.3 μg/g;Cr 0.87 - 3.5 μg/g dry weight). Concentrations of heavy metals found in flesh were as follows: Merja Zerga (Pb 0.02 - 5.25 μg/g;Cu 9.58 - 23.59 μg/g;Cr 0 - 2.71 μg/g dry weight) and Nador canal (Pb 0.06 - 6.81 μg/g;Cu 9.5 - 37.20 μg/g;Cr 0 - 3.23 μg/g dry weight). The distribution of those metals in Procambarus clarkii shows high levels of contamination for lead, copper and chrome with an absence of cadmium in both sites (Merja Zerga and Nador canal). The concentrations differed in carapace and flesh.

关键词： Procambarus clarkii Heavy Metals Merja Zerga Nador Canal Morocco

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弱交流磁场下裸铜表面结晶特性研究

制冷学报 2020年第3期41卷 153-159页

作者：孟俣刘斌单亮亮张蕊陈爱强 Georges el Achkar Bennacer rachid 天津商业大学天津市制冷技术重点实验室天津300134

本文研究了环境温度恒定为25℃、相对湿度为49%、体积为0.01 mL的液滴在-20℃裸铜底板的冻结实验,发现在附加交流磁场强度分别为2.0×10^-3、2.5×10^-3、3.0×10^-3、3.5×10^-3、4.0×10^-3、4.5×10^-3、5.0×10^-3、5.5×10^-3、6.0... 详细信息

本文研究了环境温度恒定为25℃、相对湿度为49%、体积为0.01 mL的液滴在-20℃裸铜底板的冻结实验,发现在附加交流磁场强度分别为2.0×10^-3、2.5×10^-3、3.0×10^-3、3.5×10^-3、4.0×10^-3、4.5×10^-3、5.0×10^-3、5.5×10^-3、6.0×10^-3 T的作用下,液滴结晶过冷度增大,最大过冷度提高了2.08℃;但附加磁场会减小成核驱动力;相比无磁场情况下,液滴冷凝时间减少,凝结粒径相比无磁场下较小。通过对在相同温湿度下自然对流条件的冷铜底板结霜可视化研究发现,由于附加磁场使极性水分子有序的在底板排列,较无磁场下液滴结晶过程熵增更小,在宏观上呈现液滴有序排列。此外,实验发现在0~6×10^-3 T的磁场强度范围,随着磁场强度的增大,平板单位面积结霜量减小,单位面积结霜量与交流磁场强度有较高的相关性,得到了拟合关系式。

关键词：交流磁场液滴冻结过冷度单位面积结霜量

Effect of Sinusoidal Heating on Natural Convection Coupled to Thermal Radiation in a Square Cavity Subjected to Cross Temperature Gradients

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Journal of electronics Cooling and Thermal Control 2013年第1期3卷 7-21页

作者： rachid el Ayachi Abdelghani Raji Mohamed Naimi Hassan elharfi Mohammed Hasnaoui Laboratory of Flows and Transfers Modelling(LAMET) Physics DepartmentFaculty of Sciences and TechnicsSultan Moulay Slimane UniversityBeni-MellalMorocco Laboratory of Fluid Mechanics and Energetics(LMFE) Unit Affiliated to CNRST(URAC 27)Physics DepartmentFaculty of Sciences SemlaliaCadi Ayyad UniversityMarrakechMorocco

Coupled natural convection and surface radiation within a square cavity, filled with air and submitted to discrete heating and cooling from all its walls, is studied numerically. The thermally active elements are centrally located on the walls of the cavity. Two heating modes, called SB and SV, are considered. They correspond to bottom and vertical left elements sinusoidally heated in time, respectively, while the top and vertical right ones are constantly cooled. The remaining portions of all the walls are considered adiabatic. The parameters governing the problem are the amplitude and the period of the temporally sinusoidal temperature, the emissivity of the walls , the relative lengths of the active elements and the Rayleigh number . The effect of such parameters on flow and thermal fields and the resulting heat transfer is examined. It is shown that, during a flow cycle, the flow structure can present complex behavior, depending on the emissivity and the amplitude and period of the exciting temperature. The rate of heat transfer is generally enhanced in the case of sinusoidal heating. Also, the resonance phenomenon existence, characterized by maximum fluctuations in flow intensity and heat transfer, is proved in this study.

关键词： Natural Convection Thermal Radiation Heatlines Cross Gradients of Temperature Periodic Heating Resonant Heat Transfer Numerical Study

Wheat breeding for Hessian fly resistance at ICARDA

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The Crop Journal 2022年第6期10卷 1528-1535页

作者： Wuletaw Tadesse Samira el-Hanafi Karim el-Fakhouri Imane Imseg Fatima Ezzahra Rachdad Zakaria el-Gataa Mustapha el Bouhssini International Center for Agricultural Research in the Dry Areas(ICARDA) P.O.Box 6299RabatMorocco Biodiversity and Plant Sciences Program AbroBioSciencesMohammed VI Polytechnic UniversityLot 660-Hay Moulay Rachid43150 Ben GuerirMorocco

Hessian fly(HF),Mayetiola destructor(Say)is an important pest of wheat in North Africa,North America,Southern Europe,Northern Kazakhstan,Northwestern China,and New *** can cause up to 30%yield losses and sometimes can result in complete crop failure if infestation coincides with young stage of the wheat *** to-date have shown the availability of genetic diversity in the wheat genetic resources(landraces,wild relatives,cultivars,etc.)for resistance to Hessian *** 37 resistance genes have been reported from these wheat genetic resources for resistance to Hessian fly,of which,some have been deployed singly or in combination in the breeding programs to develop high yielding varieties with resistance to *** of resistant varieties in different agro-ecologies with other integrated management measures plays key role for the control of *** paper summarizes the importance,life cycle,mechanisms of resistance,gene mining,and wheat breeding efforts for HF resistance.

关键词： Breeding Gene introgression Hessian fly Resistance