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Broadband Quasi-Yagi Antenna for WiFi and WiMax Applications

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Wireless Engineering and Technology 2013年第2期4卷 87-91页

作者： jean-marie floc’h Ahmad El Sayed Ahmad Unité Mixte de Recherche 6164 (UMR) Institut d’Electronique et de Télécommunications de Rennes (IETR) Rennes France

In this paper, we present a broadband quasi-Yagi antenna. Good impedance matching is obtained by using parasitic elements. The antenna has been designed and successfully measured. Experimental results show that the 10 dB return loss bandwidth of this antenna is 50% operating from 2.3 Ghz to 3.8 Ghz. We obtain very flat gain (around 5 dB) over the entire bandwidth. For the design and optimization of antennas, we use hFSS CAD software from ANSOFT.

关键词： Printed Dipole Antenna Quasi-Yagi Dipole Antenna Broadband Director Reflector

Multi-Band Antenna with Three Folded Monopoles for Mobile Communication Systems

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Wireless Engineering and Technology 2020年第3期11卷 23-29页

作者： Ahmad El Sayed Ahmad Alaa Choumane jean-marie floc’h Philippe Morgand Faculty of Sciences Lebanese University Tripoli Lebanon Faculty of Public health Lebanese University Zahle Lebanon IETR INSA Rennes Rennes France Thales Communication Colombes France

This paper presents the design and the experimental characterization of a new multi-band antenna consisting of three folded monopoles dedicated to mobile communication systems. The originality of this paper is to get the PMR (Professional or Private Mobile Radio) band with the GSM (Global System for Mobile Communications), DCS (Digital Cellular System) and UMTS (Universal Mobile Telecommunications System) bands. The main lobe of the antenna radiates in the zenith direction with a linear polarization over all bands. It is interesting to design the proposed antenna in order to obtain better performances in terms of directive radiation pattern (especially in the PMR band) in comparison with the already existing antenna systems in the wireless market for similar purposes. The prototype was studied with the software CST-MWS (Micro wave studio 2012). The antenna has been designed and successfully measured.

关键词： Multi-Band Antenna Folded Monopole Directive Radiation Pattern

Design of Ellipse Antenna Array for Cellular Phone Localization Systems

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Wireless Engineering and Technology 2020年第2期11卷 13-22页

作者： Ahmad El Sayed Ahmad jean-marie floc’h Alaa Choumane Philippe Morgand Faculty of Sciences Lebanese University Tripoli Lebanon IETR INSA Rennes Rennes France Faculty of Public health Lebanese University Zahle Lebanon Thales Communication Colombes France

This paper describes our contribution in the ANR (Agence Nationale de la Recherche) project called GELOCOM (GEo-LOCalisation de telephOnes Mobiles) managed by the ThALES Communications company, dedicated to the emergency localization of cellular phones. This contribution takes place in the field of antennas, with the development of broad-band systems: a circular array of six elements with separated outputs for the receiving part. In this paper, we present the design and the characterization of broad-band double ellipse array antenna. This special structure is chosen in order to obtain a good omnidirectional radiation pattern, enhance the gain and maximize the V/h polarization ratio. In comparison with the already existing antenna systems in the wireless market for similar purposes, the proposed antenna has considerably shown better performance which makes it competitive among other antenna models. For the design and optimization of antennas, we use CST MWS software. The antennas have been designed and successfully measured.

关键词： Broad-band Antenna Double Ellipse Antenna Planar Monopole Antenna El-liptical Antenna Omnidirectional Radiation Pattern

On the Design of Planar Printed Dipole Array Antennas

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Wireless Engineering and Technology 2012年第4期3卷 203-209页

作者： jean-marie floc’h Ahmad El Sayed Ahmad Anne Claude Tarot Renaud Loison Sophia Thizon jeanYves Daden Institut d’Electronique et de Télécommunications de Rennes (IETR) Unité Mixte de Recherche 6164 (UMR) Rennes France Thales Communication Colombes France

In this paper, we propose a new design procedure for printed dipole array antennas. Applications of these arrays are devoted to wireless communication systems, mainly base stations and beam steerable antennas. All the designs have been developed at the frequency of 3 Ghz. This structure is chosen in order to enhance the gain and minimize the backside radiations of an antenna array with a very simple feeding.

关键词： Printed Antenna Array Quasi Yagi Antennas Gain and Backside Radiation Enhancement Simple Microstripfeeding

Environmental photocatalysis:Perspectives for China

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Science China Chemistry 2010年第9期53卷 1831-1843页

作者： hERRMANN jean marie Institut de Recherches sur la Catalyse et l'Environnement de Lyon UMR 5256 CNRS/Université Lyon1 2 Av.Albert Einstein 69626 Villeurbanne Cedex

Photocatalysis is based on the double aptitude of the photocatalyst(essentially titania) to simultaneously adsorb reactants and absorb efficient *** photocatalysis is able to be efficient in Fine,"Green" and Environmental *** induces mild oxidations in the absence of water by generating active neutral atomic O* *** instance,the oxidation of 4-tert-butyl-toluene is 100% selective in *** water treatment,many toxic inorganic ions are oxidized in their harmless upper oxidized *** elimination of organic pollutants is the main field of water photocatalytic *** of aliphatic and aromatic pollutants are totally mineralized into CO2 and innocuous inorganic *** complex molecules,such as pesticides(herbicides,insecticides,fungicides,etc.) or dyes,are totally *** example of green chemistry is the total degradation of dyes in water,in particular for the azo-dyes,with 100% selective degradation of -N=N-azo-groups into *** is also active in the "bio-world" by killing bacteria(***,streptococcus,etc.) in water without *** pollutants can also be destroyed,especially all the VOC's(volatile organic compounds),providing certain air humidity enabling titania to produce cracking Oh* *** chemical engineering reasons,the photocatalyst has to be fixed on a photo-inert *** these conditions,UV-irradiated titania-based photocatalysis could be applied to the elimination of air pollutants,VOC's,solvents,odors,chemicals,*** treatment has to be associated with water and solid waste treatment because of *** is conducted by covering water treatment ponds or lagunas by rafts on which large sheets of Ahlstrom paper are deposited,supporting titania associated with activated ***,virus Ah5N2,a model virus close to h5N1,responsible for the avian flu could be totally *** is directly connected wi

关键词： photocatalysis green chemistry environmental chemistry air pollutants water pollutants solar energy China

Trifluoromethyl radical triggered radical cyclization of N-benzoyl ynamides leading to isoindolinones

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Science China Chemistry 2019年第11期62卷 1542-1546页

作者： Maud Cassé Christian Nisole héloise Dossmann Yves Gimbert jean-marie Fourquez Laure haberkorn Cyril Ollivier Louis Fensterbank Sorbonne Université CNRSInstitut Parisien de Chimie MoléculaireIPCM75005 ParisFrance Institut de Recherches Servier 78290 Croissy-sur-SeineFrance Département de Chimie Moléculaire CNRSUniversitéGrenoble Alpes38610 GièresFrance

Under photocatalytic reductive conditions,trifluoromethyl radical addition onto an ynamide followed by cyclization on a benzoyl moiety produces diverse isoindolinone platforms with good *** selectivity of the radical cyclization,N-benzoyl vs.N-benzyl as radical acceptor and the E/Z ratio of isomers have been rationalized by modeling.

关键词： ynamides trifluoromethylation photocatalysis cascade reactions tandem processes isoindolinones modeling

Fluoride hydro-geochemistry Studies:A Case Study from Granitic Aquifer System of Maheshwaram,hyderabad,India

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地学前缘 2009年第S1期16卷 11-12页

作者： Surendra Atal hélène Pauwels jean-marie Gandolfi Shakeel Ahmed National Geophysical Research Institute(CSIR) BRGM 3 Avenue Claude Guillemin 45060 Orleans IFCGR National Geophysical Research Institute(CSIR)

The impact of population pressure has been observed on several systems,groundwater resource is one among *** and over-exploitation has not only caused the decline of groundwater levels but also causes deterioration in... 详细信息

关键词： fluorine hydro-geochemistry granites hard rock aquifer

Lessons from “real life experience” of rifaximin use in the management of recurrent hepatic encephalopathy

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World Journal of hepatology 2020年第1期12卷 10-20页

作者： Fiona Chautant Maeva Guillaume marie-Angèle Robic jean-François Cadranel jean-marie Peron hortensia Lison Charlène Cool Christophe Bureau Véronique Duhalde Service Pharmacie Centre Hospitalier Universitaire de ToulouseHôpital Paule de ViguierToulouse 31059France Department of hepato-Gastroenterology University HospitalToulouse 31059France Department of hepato-Gastroenterology Laennec HospitalCreil 60109France Department of Pharmacy and UMR INSERM 1027 University HospitalToulouse 31059France Department of Pharmacy University Hospital ToulouseToulouse 31059France

BACKGROUND hepatic encephalopathy(hE)is a major complication of cirrhosis with independent prognostic *** current management of hE is mainly based on *** has been shown to decrease the risk of hE recurrence in patients with episodic *** can also be ***,there is no drug support recommendation for rifaximin use in this *** To assess the effectiveness of rifaximin in the management of recurrent episodes of hE and recurrent acute exacerbations on persistent hE,in“real life conditions”.METhODS In this retrospective study,using a within-subjects design,we collected data of patients treated with rifaximin for hE in two liver diseases centers,during the six-month period before and during the six-month period after the initiation of *** primary effectiveness endpoint was the total number of hE events involving *** Rifaximin was introduced for prevention of recurrent hE episodes in 29 out of 62 patients with normal mental status between episodes and for prevention of recurrent acute exacerbations on persistent hE in 33 out of 62 *** the“prevention of recurrent hE episodes”group,fewer hE events(0.79 vs 1.78;P=0.013)were reported during the period of time when rifaximin was *** the“prevention of recurrent acute exacerbations on persistent hE”group,there was no significant difference in the number of hE-events(1.48 vs 1.77;P=0.582).CONCLUSION In this real-life experience,the effectiveness of rifaximin was confirmed in the prevention of hE episodes recurrence but was not proved in the prevention of acute exacerbations recurrence on persistent hE.

关键词： Rifaximin hepatic encephalopathy Cirrhosis Liver disease hospitalization

Internal carotid thrombus in patients with inflammatory bowel disease:Two cases

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World Journal of Gastroenterology 2013年第5期19卷 773-775页

作者： Sébastien Richard Gioia Mione Julien Perrin marie Toussaint-hacquard jean-Christophe Lacour Xavier Ducrocq Department of Neurology CHU NancyHospital Central54035 Nancy CedexFrance Department of Biological hematology CHU Nancyhpitaux de Braboisrue du Morvan54511 Vandoeuvre-les-Nancy CedexFrance

Increased ischemic stroke risk is observed in patients with inflammatory bowel disease(IBD).Causes and physiopathological aspects of cerebral infarct,in this specific population,are less often *** is little information to provide guidelines for the best curative and preventive *** report 2 cases of ischemic strokes due to internal carotid thrombus in patients during active phase of *** of early atherosclerotic plaques activated by a hypercoagulation state may cause a thrombus.A combined therapy with heparin and corticosteroids was used for both our *** of the thrombus was obtained after several days without surgical treatment and shown by *** cases highlight an aetiology of stroke in patients with IBD and use of a synergic treatment to respond to hypercoagulability in link with IBD. Benefits and safety of this therapy should be confirmed with clinical studies.

关键词： Inflammatory bowel disease Ischemic stroke Carotid thrombus hypercoagulable state Atherosclerosis