28 research outputs found

    Performance of Glass Resistive Plate Chambers for a high granularity semi-digital calorimeter

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    A new design of highly granular hadronic calorimeter using Glass Resistive Plate Chambers (GRPCs) with embedded electronics has been proposed for the future International Linear Collider (ILC) experiments. It features a 2-bit threshold semi-digital read-out. Several GRPC prototypes with their electronics have been successfully built and tested in pion beams. The design of these detectors is presented along with the test results on efficiency, pad multiplicity, stability and reproducibility.Comment: 16 pages, 15 figure

    Construction and commissioning of a technological prototype of a high-granularity semi-digital hadronic calorimeter

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    A large prototype of 1.3m3 was designed and built as a demonstrator of the semi-digital hadronic calorimeter (SDHCAL) concept proposed for the future ILC experiments. The prototype is a sampling hadronic calorimeter of 48 units. Each unit is built of an active layer made of 1m2 Glass Resistive Plate Chamber(GRPC) detector placed inside a cassette whose walls are made of stainless steel. The cassette contains also the electronics used to read out the GRPC detector. The lateral granularity of the active layer is provided by the electronics pick-up pads of 1cm2 each. The cassettes are inserted into a self-supporting mechanical structure built also of stainless steel plates which, with the cassettes walls, play the role of the absorber. The prototype was designed to be very compact and important efforts were made to minimize the number of services cables to optimize the efficiency of the Particle Flow Algorithm techniques to be used in the future ILC experiments. The different components of the SDHCAL prototype were studied individually and strict criteria were applied for the final selection of these components. Basic calibration procedures were performed after the prototype assembling. The prototype is the first of a series of new-generation detectors equipped with a power-pulsing mode intended to reduce the power consumption of this highly granular detector. A dedicated acquisition system was developed to deal with the output of more than 440000 electronics channels in both trigger and triggerless modes. After its completion in 2011, the prototype was commissioned using cosmic rays and particles beams at CERN.Comment: 49 pages, 41 figure

    Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

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    无线传感器网络,作为全球未来十大技术之一,集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术,可实时感知、采集、处理、传输网络分布区域内的各种信息数据,在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议,并针对大规模的无线传感器网络设计了一种树状路由协议,它根据节点地址信息来形成路由,从而简化了复杂繁冗的路由表查找和维护,节省了不必要的开销,提高了路由效率,实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR(AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位:工学硕士院系专业:信息科学与技术学院通信工程系_通信与信息系统学号:2332007115216

    Biological activities of phenolics from leaves of Tunisian Cydonia oblonga miller

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    We examined the antioxidant and antimicrobial activities of quince (Cydonia oblonga Miller) leaf methanol extract of Tunisian variety Commune. Chromatographic characterization of the leaf extract using HPLC-MS/MS revealed the presence of 9-phenolic acids and flavonoids. Among these polyphenols, 6-were identified, one as caffeoylquinic acid (4-O-caffeoylquinic acid), two as quercetin heterosides (quercetin-3-O-rutinoside and quercetin-3-O-galactoside), and three as kaempferol heterosides (kaempferol-3-O-rutinoside, kaempferol-3-O-glycoside and kaempferol-3-O-glucoside). The leaf methanol extract had DPPH (2,2-diphenyl-1-picrylhydrazyl) friiee radical-scavenging activity, inhibited the pre-formed radical ABTS. + (2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid) and also inhibited the formation of hydroxyl radical. The antimicrobial potential of quince leaf extract was also tested against 8-pathogenic bacteria by disc diffusion method (namely, Salmonella typhimurium (ATCC 14028), Escherichia coli (ATCC 6538), Enterococcus faecalis (ATCC 29212), Enterococcus faecium (ATCC 19434), Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus agalactiae, Bacillus subtilis, and Saccharomyces cerevisiae).Scopu

    Intérêt du Télos dans l'évaluation de la laxité chronique antérieure du genou en pré- et en postopératoire

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    Le Télos est une technique de radiographie dynamique, mécanique, passive, comparative et reproductible, fixant sur un cliché le test de Lachman (cliché de Lachman passif). La laximétrie au Télos s'avère un complément objectif à l'examen clinique pour atteindre un triple but : diagnostique, pronostique et thérapeutiqu

    Positive effects of salicylic acid pretreatment on the composition of flax plastidial membrane lipids under cadmium stress

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    Interest in use of flax (Linum usitatissimum L.) as cadmium (Cd)-accumulating plant for phytoextraction of contaminated soils opened up a new and promising avenue toward improving tolerance of its varieties and cultivars to Cd stress. The aim of this study is to get insights into the mechanisms of Cd detoxification in cell membranes, by exploring the effects of salicylic acid (SA)-induced priming on fatty acids and lipid composition of flax plantlets, grown for 10 days with 50 and 100 μM Cd. At leaf level, levels of monogalactosyldiacylglycerol (MGDG), phosphatidylcholine (PC), phosphatidylglycerol (PG), and neutral lipids (NL) have shifted significantly in flax plantlets exposed to toxic CdCl2 concentrations, as compared to that of the control. At 100 μM Cd, the linoleic acid (C18:2) decreases mainly in digalactosyldiacylglycerol (DGDG) and all phospholipid species, while linolenic acid (C18:3) declines mostly in MGDG and NL. Conversely, at the highest concentration of the metal, SA significantly enhances the levels of MGDG, PG and phosphatidic acid (PA), and polyunsaturated fatty acids mainly C18:2 and C18:3. Furthermore, SA pretreatment seems to reduce the Cd-induced alterations in both plastidial and extraplastidial lipid classes, but preferentially preserves the plastidial lipids by acquiring higher levels of polyunsaturated fatty acids. These results suggest that flax plantlets pretreated with SA exhibits more stability of their membranes under Cd-stress conditions.This research was supported by the Ministry of Higher Education, Scientific Research and Technology in TunisiaPeer reviewe
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