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Wind-diesel hybrid power system integration in the south Algeria

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Frontiers in Energy 2015年第3期9卷 259-271页

作者： Khaireddine ALLALI El Bahi AZZAG Nabil KAHOUL department of Electrical Engineering Badji Mokhtar University- Annaba Annaba 23000 Algeria laboratoire d'electrotechnique d'Annaba Badji Mokhtar University-Annaba Annaba 23000 Algeria

In most isolated sites situated in south Algeria, the diesel generators are the major source of electrical energy. Indeed, the power supply of these remote regions still poses order problems （technical, economical and ecological）. The electricity produced with the help of diesel generators is very expensive and responsible for CO2 emission. These isolated sites have significant wind energy potential. Hence, the use of twinning wind-diesel is widely recommended, especially to reduce operating deficits. The objective of this paper is to study the global modeling of a hybrid system which compounds wind turbine generator, diesel generator and storage system. This model is based on the control strategy to optimize the functioning of the hybrid system and to consolidate the gains to provide proper management of energy sources （wind, diesel, battery） depending on the load curve of the proposed site. The management is controlled by a controller which ensures the opening/closing of different power switches according to meteorological conditions （wind speed, air mass, temperature, etc）.

关键词： wind-diesel storage system isolated site,management simulation

Orbits of Jacobi forms and theta relations

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Science China Mathematics 2025年

作者： Valery Gritsenko Haowu Wang laboratoire Paul Painlevé Université de Lille International Laboratory for Mirror Symmetry and Automorphic Forms National Research University Higher School of Economics School of Mathematics and Statistics Wuhan University

Jacobi theta functions with rational characteristics can be viewed as vector-valued Jacobi *** relations usually correspond to different constructions of certain Jacobi forms. From this observation, we extract a new approach, which is called orbits of Jacobi forms, to produce identities on Jacobi theta *** approach not only provides simple proofs of many known theta relations but also produces a large number of new identities, which can be considered as generalizations of Riemann’s theta relations.

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doppler Global Velocimeter-development and Validation with Measurements in a Round Free Jet

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Journal of Thermal Science 2009年第1期18卷 74-84页

作者： X.Ottavy S.Goguey J.Berthiau I.Trébinjac laboratoire de Mécanique des Fluides et d’Acoustique(LMFA)

doppler global velocimetry （dGV） has already been shown to be an interesting technique capable of measuring the three components of velocity in a plane. A 1-component dGV system is currently under development at the LMFA, using a stabilized continuous wave （CW） argon ion laser for ermssion, lne receiver Ieatures only one camera for both signal and reference images and incorporates a dEF1 system to adjust the incident laser light frequency and its transmission coefficient on the iodine cell absorption line. A description of the whole system is presented and a validation with measurements of axial velocities at several positions in a round free jet is proposed.

关键词： laser anemometry doppler shift iodine vapor absorption line filter dEFI system image processing.

Electrical Energy Quality Analysis in Hospital Centres

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Smart Grid and Renewable Energy 2021年第4期12卷 53-63页

作者： Abdourahimoun daouda Sani Idi Boubabacar Moctar Mossi Idrissa Saidou Madougou laboratoire d’Energétique d’Electronique d’Electrotechnique d’Automatique et d’Informatique Industrielle Université Abdou Moumouni Niamey Niger

Today, energy is a vital component in the functioning of a hospital. Hospital technical facilities have several types of technologies, these include appliances for use;examination apparatus. So, for Quality Health Care in a hospital, there is a need to ensure the proper functioning of hospital equipment. In addition to the required maintenance as specified by the device manufacturer, the quality of the electrical energy across the device must be ensured. This article is an analysis of the quality of electric energy at the substation of National Hospital of Niamey. Thereby, the data collection, followed by the data processing and analysis revealed the parameters characterizing the quality of electrical energy across the substation. Our studies have shown that the substation is underutilized as the maximum inrush current is less than half the available current. The current was consumed by the three phases has resulted in a strong current unbalance (230 A). However, the current unbalance and the voltage amplitude, are admissible accordingly base on EN50160 standard. Furthermore, the harmonics voltages present in this medium are

First-principles study of the new potential photovoltaic absorber:Cu_2MgSnS_4 compound

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Chinese Physics B 2017年第7期26卷 294-304页

作者： Belmorsli Bekki Kadda Amara Mohammed El Keurti laboratoire d'étude physico-chimique Université Dr.Moulay Tahar de Saida

The structural, electronic, optical, and elastic properties of Cu_2MgSnS_4 in four crystalline phases（wurtzite-stannite（WS）, stannite（ST）, kesterite（KS）, and primitive-mixed Cu Au（PMCA）） are investigated using density functional theory（dFT） in the framework of the full potential linearized augmented plane wave plus local-orbitals（FP-LAPW＋lo） method within the generalized gradient approximation based on the Perdew 2008 functional（GGA-PBEsol）. For each phase, the structural parameters, bulk modulus, and its pressure derivative are calculated. The relative stability of these phases is also discussed. In addition, the elastic constants have been calculated in order to investigate the mechanical stability of all phases. Moreover, the anisotropy factor, shear modulus, Young＇s modulus, Lame＇s coefficient, and Poisson＇s ratio have been estimated from the calculated single crystalline elastic constants. For the band structure, the density of states and optical properties of the exchange and correlation effects are treated by the Tran-Blaha modified Becke-Johnson potential to give a better description of the band-gap energies and optical spectra. The obtained results are compared with available experimental data and to other theoretical calculations.

关键词： quaternary chalcogenide semiconductor elastic constants electronic properties optical properties

Expression of matrix metalloproteinases and tissue inhibitor metalloproteinases increases in X-irradiated rat ileum despite the disappearance of Cd8a T cells

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World Journal of Gastroenterology 2005年第40期11卷 6312-6321页

作者： Carine Strup-Perrot Marie-Catherine Vozenin-Brotons Marie Vandamme Christine Linard denis Mathé laboratoire d'étude des pathologies Radio-induites laboratoire UPRES EA 27-10 'Radiosensibilité des tumeurs et tissus sains'

AIM： To investigate their expression and activity in the rat ileum after exposure to ionizing radiation along with that of the cellular effectors and molecular mediators involved in the regulation of MMPs. METHOdS： Rats were exposed to a single 10-Gy dose of X-rays delivered to the abdomen. A combination of methods, such as zymography, immunohistochemistry and real time reverse transcriptase-polymerase chain reaction, were used to localize and quantify MMPs and the molecules involved in MMP activating and inhibitory pathways （plasmin/ plasminogen, TIMPs）, Cd^8＋, as well as inflammatory （interleukin （IL）-1β, IL-8, tumor necrosis factor-s, TNF-α） and fibrogenic mediators （transforming growth factor- β1-3） within ileal tissue at 1, 3, and 7 d after irradiation. RESULTS： A marked increase in MMP-2 and -14 mRNA and protein levels associated with an increased activity of MMP-2 was observed in irradiated ileal tissue. MMP-2 and -14 expression was mainly observed in inflammatory, epithelial, and mesenchymal cells, whereas a slight increase in MMP-3 expression was detected in the few infiltrating macrophages at d i after irradiation. Conversely, MMP-1, -7, and -9 mRNA levels were not found to be affected by abdominal irradiation. Irradiation was found to induce disappearance of Cd^8＋ cells. Furthermore, we have observed that TNF-α and IL-1β protein levels increased 6 h after irradiation, whereas those of IL-8 only increased after 3 d and was concomitant with neutrophil infiltration. In addition, the expressions of molecules involved in MMP activating and inhibitory pathways （urokinase-type plasminogen activator andtissue-type plasminogen activator; TIMP-1, TIMP-2, and plasminogen activator-inhibitor-i） were found to be increased after abdominal irradiation. CONCLUSION： This study showed that abdominal irradiation induces an acute remodeling of the ileum associated with an increased expression of MMPs and TIMPs that do not involve Cd^8＋ T cells but involve mesenchymal and epi

关键词： Matrix metalloproteinases Irradiation Ileum T cells Cytokines

Multi-Objective Optimization of the Safe Operation of the Electrical distribution System by Placing d-FACTS and Network Reconfiguration

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Journal of Power and Energy Engineering 2019年第9期7卷 94-113页

作者： Arouna Oloulade Adolphe Moukengue Imano Xavier Fifatin Antoine Vianou Herman Tamadaho Ramanou Badarou laboratoire d’electrotechnique de Télécommunications et d’Informatique Appliquée (LETIA) University of Abomey-Calavi Abomey-Calavi Benin

The distribution networks of agglomerated areas of the developing countries are generally the seat of overloads, voltage drops, and untimely interruptions of the power supply. This paper consisted of optimizing the grid topology and placement of a dSTATCOM in a SBEE real distribution network in order to improve its technical performance. The modified ant colony algorithms solved this difficult combinatorial problem, which integrated among the criteria, the minimization of the losses and the deviation of the node voltages under operational constraints about distribution networks operation. According to the results obtained, the optimization of the topology of a distribution network and the placement of dSTATCOM contributed qualitatively to improve the losses, voltage and stability plans of the Togba distribution network. Actually, the hybridization of optimization means such as the placement of dSTATCOM and the reconfiguration of the networks applied to the Togba HVA network made the power of dSTATCOM optimization possible by almost 50.71% and reduce losses to 83.57%. The implementations of those algorithms are very efficient and effective, and can be implemented to help distribution system operators, developing countries and in particular, the operators of the Beninese Electric Power Company to perform their electrical network.

关键词： Reconfiguration Ant Colony Electrical Stability Radial distribution Network

Topological Studies of Three-dimensional Flows in a High Pressure Compressor Stator Blade Row without and with Boundary Layer Aspiration

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Chinese Journal of Aeronautics 2011年第5期24卷 541-549页

作者： Ankit SACHdEVA Francis LEBOEUF laboratoire de Mécanique des Fluides et d'Acoustique Ecole Centrale de Lyon

This paper presents a numerical study of the flow topologies of three-dimensional （3d） flows in a high pressure compressor stator blade row without and with boundary layer aspiration on the hub wall. The stator blade is representative of the first stage operating under transonic inlet conditions and the blade design encourages development of highly complex 3d flows. The blade has a small tip clearance. The computational fluid dynamics （CFd） studies show progressive increase of hub corner stall with the increase in incidence. Aspiration is implemented on the hub wall via a slot in the comer between the hub wall and the suction surface. The CFd studies show aspiration to be sensitive to the suction flow rate; lower rate leads to very complex flow struc- tures and increased level of losses whereas higher rate renders aspiration effective for control of hub comer separation. The flow topologies are studied by trace of skin friction lines on the walls. The nature of flow can be explained by the topological rules of closed separation. Furthermore, a deeper analysis is done for a particular case with advanced criterion to test the non-degeneracy of critical points in the flow field.

关键词： high pressure compressor flow topologies three-dimensional flows boundary layer aspiration tip clearance

Physico-chemical and mechanical properties of Ti_3SiC_2-based materials elaborated from SiC/Ti by reactive spark plasma sintering

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Journal of Advanced Ceramics 2019年第1期8卷 47-61页

作者： Faten TURKI Houyem ABdERRAZAK Frédéric SCHOENSTEIN Florent TêTARd Mohieddine ABdELLAOUI Noureddine JOUINI laboratoire des Matériaux Utiles Institut National de Recherche et d’Analyse Physico-chimique laboratoire de Sciences des Procédés et Matériaux Université Paris 13 Sorbonne Paris Cité CNRS

In this paper, the synthesis of Ti_3 SiC_2 from SiC/Ti powder using reactive spark plasma sintering(R-SPS) in the temperature range of 1300-1400 ℃ is reported. The results show that the purity of Ti_3 SiC_2 is improved up to 75 wt% when the holding time is increased from 10 to 20 min at1400 ℃. The thermodynamic and experimental results indicate that Ti_3 SiC_2 formation takes place via the reaction of a pre-formed TiC phase with the silicides, formed from the eutectic *** analysis of mechanical behaviour indicates that samples with higher percentage of secondary phases exhibit higher microhardness and better resistance compared to the near single phase Ti_3 SiC_2.

关键词： Ti3SiC2 reactive spark plasma sintering(R-SPS) density mechanical properties