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Analyses on an electronic voltage transformer's failure by its resonance with very fast transient overvoltage and suppression

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High Voltage 2024年第1期9卷 150-162页

作者： Ruoyu Han houda Zhu Qing Chen Hongbin Li Yue Tong Linshan Han Yang Jiao School of Electrical and Electronic Engineering Huazhong University of Science and TechnologyWuhanChina China Electric Power Research Institute WuhanChina School of Artificial Intelligence and Automation Huazhong University of Science and TechnologyWuhanChina

As voltage measuring devices are widely used in the high voltage power system with a primary-secondary-fusion structure,electronic voltage transformers are directly connected to the primary conductor and would face much more serious electromagnetic environments than general secondary *** a result,they would still experience failures even when general protection measures are adopted to suppress overvoltages'*** address this issue,an innovative method is proposed after analyses are conducted on the resonance between a transformer and an *** this method,an air-cored coil is installed in a transformer to artificially shift its natural frequency and to dodge the high-frequency dominant component of a transient overvoltage,avoiding the aforementioned resonance and suppressing the secondary *** addition,simulations and laboratory tests are conducted to prove this method's validity.

关键词： transient resonance mentioned

Chemically Mediated Interactions between Grapevine, Aphid, Ladybird, and Ant in the Context of Insect Chemical Ecology

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Phyton-International Journal of Experimental Botany 2024年第7期93卷 1523-1542页

作者： Taghreed Alsufyani Noura J.Alotaibi Nour houda M’sakni Mona A.Almalki Eman M.Alghamdi Department of Chemistry College of ScienceTaif UniversityP.O.Box 11099Taif21944Saudi Arabia Department of Biology College of ScienceTaif UniversityP.O.Box 11099Taif21944Saudi Arabia Chemistry Department Faculty of ScienceKing AbdulAziz UniversityP.O.Box 80200Jeddah21589Saudi Arabia

This study simpliﬁes the complex relationship among grapevine plants,aphids,ladybirds,and ants,which is essential for effective pest management and ecological *** study investigated the impact of aphid attacks and the presence of ants and ladybirds on the volatile compounds proﬁle released into the chemosphere of the community consisting of the common vine Vitis vinifera,the aphid Aphis illinoisensis,the ladybird Cocci-nella undecimpunctata-and the ant Tapinoma *** study aims to analyze the volatile compounds emitted by the grapevine and surrounding insects in response to these intricate *** extraction of volatile organic compounds(VOCs)was carried out using closed-loop stripping(CLS)and then analyzed via gas chromatography-mass spectrometry(GC-MS)and principles coordinated analysis(PCA)was *** grapevine was exposed to different types and order of treatments,including non-infested,aphid-infested,aphid-infested with ant,aphid-infested with ladybird,and various combinations of ant and *** the aphid attack,the outcomes uncovered massive alterations in the volatile compound proﬁ*** grapevine displayed distinct emissions of germacrene D,an alcohol,and an alkene compared to non-infested *** characteristic VOC proﬁle was the share of infested grapes in the presence of ants,with benzene derivatives and sesquiterpenes dominating the *** coexistence of ladybirds with ants and aphids resulted in a dif-ferent volatile proﬁle characterized by elevated levels of aldehydes,ketones,α-farnesene,and its hydroxy *** was concluded that the emission of VOCs into the chemosphere of the grapevine communities varied qualitatively and quantitatively depending on the level of the relationship complexity within each community in response to the infestation of grapevines by aphids,the presence of ladybirds as natural predators,and the presence of ant as *** grapevine’s status-dependent compounds

关键词： Aphids Aphis illinoisensis volatile organic compounds chemosphere pest management gas chromatography-mass spectrometry closed-loop stripping

Juvenile Systemic Sclerosis: About 9 Cases

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Open Journal of Pediatrics 2024年第2期14卷 320-326页

作者： Kaoutar Danaoui houda Nassih Khadija Oujennane Rabiy El Qadiry Aicha Bourrahouat Said Amal Imane Ait Sab B Pediatric Ward Mohammed VI University Hospital Center Marrakesh Morocco Dermatology Ward Mohammed VI University Hospital Center Marrakesh Morocco

Scleroderma is a rare disease with two primary forms: localized scleroderma (LS) and systemic sclerosis (SSc). Both are chronic conditions that can manifest in various patterns (subtypes) and are linked to extracutaneous involvement in pediatric patients. Juvenile SSc poses a higher risk of morbidity and mortality, with patients facing life-threatening complications such as lung, heart, and visceral organ fibrosis, and vasculopathy. In contrast, mortality is extremely rare in juvenile LS, but patients are susceptible to significant morbidity, leading to severe disfigurement and functional impairment. Treatment for scleroderma aims to control inflammation and address specific issues. An early diagnosis significantly enhances the overall outcome. This study conducts a retrospective descriptive analysis aiming to document the clinical manifestations, management approaches, and outcomes of systemic sclerosis in a cohort of nine children receiving treatment for juvenile systemic sclerosis at Pediatric B department of Mohammed VI University, Hospital Center in Marrakech, Morocco.

关键词： Scleroderma Systemic Sclerosis Children Pediatric

Positron Affinity, Deformation Potential and Diffusion Constant in AlxIn1-xSb Ternary Semiconductor Alloys

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Acta Metallurgica Sinica(English Letters) 2016年第7期29卷 661-667页

作者： Nour EI-houda Fares Nadir Bouarissa Materials and Electronic Systems Laboratory University of Bordj-Bou-Arr6ridj 34000 Bordj-Bou-Arr6ridj Algeria Laboratory of Materials Physics and Its Applications University of M'sila 28000 M'sila Algeria 9 Rue K Fg des martyrs 34000 Bordj-Bou-Arreridj Algeria

The present investigation deals with the positron behaviour in Alxlnl_xSb ternary semiconductor alloys in the zinc-blende phase. The calculations are mainly based on a pseudopotential approach coupled with the independent particle model. Features such as elastic constants, electron and positron chemical potentials, positron deformation potential and positron diffusion constant are determined. Moreover, the positron affinity to InSb, A1Sb and their related ternary alloys and heterostructures is calculated. The present results are compared to experiment and found to be in reasonably good agreement. The information gathered from the present study can help in understanding the positron trapping at interfaces and precipitates and might be useful in slow-positron-beam experiments.

关键词： Semiconductor alloys Positrons Diffusion Surface and interface states Heterostructures

Analysis of the Influence of Viscosity and Thermal Conductivity on Heat Transfer by Al2O3-Water Nanofluid

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Fluid Dynamics & Materials Processing 2020年第2期16卷 181-198页

作者： houda Jalali Hassan Abbassi Unit of Computational Fluid Dynamics and Transfer Phenomena National Engineering School of Sfax(ENIS)University of SfaxSfaxTunisia

The addition of nanoparticles into liquid,even at low concentrations,leads to an increase in both,dynamic viscosity and thermal ***,the increase in temperature causes an increase in thermal conductivity and a decrease in the nanofluid *** this context,a numerical investigation of the competition between viscosity and thermal conductivity about their effects on heat transfer by Al_(2)O_(3)-water nanofluid was conducted.A numerical study of heat transfer in a square cavity,filled with Al_(2)O_(3)-water nanofluid and heated from the left side,was presented in this ***,momentum,and thermal energy equations are solved by the finite volume *** the pressure-velocity coupling,the SIMPLER algorithm was *** working conditions,allowing the increase of heat transfer,are *** addition,two correlations for viscosity and thermal conductivity of Al_(2)O_(3)-water nanofluid as functions of the concentration and diameter size based on experimental measurement are *** correlations were more precisely compared to those given by the theoretical ***,other models for viscosity and conductivity depending on temperature are used and *** results reveal that heat transfer by Al_(2)O_(3)-water nanofluid is enhanced only when the temperature exceeds 40℃ and the diameter size does not exceed a certain limit of the order of 45-50 nm depending on temperature.

关键词： Heat transfer nanofluid viscosity thermal conductivity

Analysis of the Influence of Viscosity and Thermal Conductivity on Heat Transfer By Al_(2)O_(3)-Water Nanofluid

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Fluid Dynamics & Materials Processing 2019年第3期15卷 253-270页

作者： houda Jalali Hassan Abbassi Unit of Computational Fluid Dynamics and Transfer Phenomena National Engineering School of Sfax(ENIS)University of SfaxSfaxTunisia

关键词： Heat transfer nanofluid viscosity thermal conductivity

Second Order Sliding Mode Control for Discrete Decouplable Multivariable Systems via Input-output Models

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International Journal of Automation and computing 2015年第6期12卷 630-638页

作者： houda Romdhane Khadija Dehri Ahmed Said Nouri Numerical Control of Industrial Processes National Engineering School of Gabes University of Gabes

The problem of the chattering phenomenon is still the main drawback of the classical sliding mode control. To resolve this problem, a discrete second order sliding mode control via input-output model is proposed in this paper. The proposed control law is synthesized for decouplable multivariable systems. A robustness analysis of the proposed discrete second order sliding mode control is carried out. Simulation results are presented to illustrate the effectiveness of the proposed strategy.

关键词： Discrete second order sliding mode control decoupl

Dynamic characteristics and improved MPPT control of PV generator

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Frontiers in Energy 2013年第3期7卷 342-350页

作者： houda BRAHMI Rachid DHIFAOUI Higher Institute of Medicals Technologies (ISTMT) 9 Rue ZouhairEssafi 1006 Tunis Tunisia National Institute of Applied Sciences and Technology (INSAT) Centre Urbain Nord BP 6761080 Tunis Cedex Tunisia

This paper presents a mathematical model of photovoltaic （PV） module and gives a strategy to calculate online the maximum power point （MPP）. The variation of series and shunt resistor are taken into account in the model and are dynamically identified using the Newton-Raphson algorithm. The effectiveness of the proposed model is verified by laboratory experiments obtained by implementing the model on the dSPACE DS1104 board.

关键词： modeling of photovoltaic (PV) generator maximum power point tracking (MPPT) estimation para meters real time controller

A New Sliding Function for Discrete Predictive Sliding Mode Control of Time Delay Systems

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International Journal of Automation and computing 2013年第4期10卷 288-295页

作者： Abdennebi Nizar Ben Mansour houda Nouri Ahmed Said Numerical Control of Industrial Processes National Engineering School of Gabes University of Gabes

The control of time delay systems is still an open area for research. This paper proposes an enhanced model predictive discrete-time sliding mode control with a new sliding function for a linear system with state delay. Firstly, a new sliding function including a present value and a past value of the state, called dynamic surface, is designed by means of linear matrix inequalities （LMIs）. Then, using this dynamic function and the rolling optimization method in the predictive control strategy, a discrete predictive sliding mode controller is synthesized. This new strategy is proposed to eliminate the undesirable effect of the delay term in the closed loop system. Also, the designed control strategy is more robust, and has a chattering reduction property and a faster convergence of the system s state. Finally, a numerical example is given to illustrate the effectiveness of the proposed control.

关键词： State time delay systems discrete sliding mode control model predictive control dynamic sliding function linear matrix inequalities (LMIs) chattering.