69 research outputs found
Système de suivi des appels d'offres
Face au nombre croissant d'appels d'offres générés dans la division, tant pour le projet LHC que pour l'activité courante, il s'avère désormais nécessaire de mettre en place un système de suivi rigoureux. Il s'agit de fournir au chef de division une information précise en temps réel de la situation de chaque appel d'offres, permettant ainsi de garantir le respect des procédures CERN d'adjudication. Ceci passe par une centralisation sous format papier de tous les documents techniques et commerciaux dans leur dernière version. Toutes ces informations doivent également être intégrées au sein d'un outil informatique adapté. Ce programme devra ainsi dégager automatiquement le degré d'avancement des différents appels d'offres et mettre en évidence les éventuels écarts et dysfonctionnements par rapport à la procédure. Ce papier insistera enfin sur l'importance de la gestion des flux d'information et les moyens mis en oeuvre pour les canaliser
Logistique de transport pour le projet LHC: enseignements des premiers secteurs
Ce papier dresse un premier bilan de la logistique de transport mise en place pour l'installation du LHC. Les moyens de planification mis en oeuvre seront tout d'abord évoqués avec notamment les réunions avec les groupes utilisateurs, l'élaboration de procédures de transport, la génération de listings d'articles à transporter ou encore l'établissement d'un planning des ressources. Cependant, les premiers travaux d'installation du LHC ont fait apparaître des divergences importantes entre le planning logistique établi et la réalité du terrain. Ces écarts seront analysés, qu'il s'agisse de différences sur le volume de matériel à acheminer, d'opérations non planifiées, de changements de plannings entraînant de longues et délicates traversées de chantiers ou de manque de planification des besoins en personnel dans certaines zones. Tous ces enseignements acquis au cours des premiers travaux devraient permettre de dégager des voies d'amélioration à mettre en place pour les prochains secteurs
Handling and Transport of Oversized Accelerator Components and Physics Detectors
For cost, planning and organisational reasons, it is often decided to install large pre-built accelerators components and physics detectors. As a result surface exceptional transports are required from the construction to the installation sites. Such heavy transports have been numerous during the LHC installation phase. This paper will describe the different types of transport techniques used to fit the particularities of accelerators and detectors components (weight, height, acceleration, planarity) as well as the measurement techniques for monitoring and the logistical aspects (organisation with the police, obstacles on the roads, etc). As far as oversized equipment is concerned, the lowering into the pit is challenging, as well as the transport in tunnel galleries in a very scare space and without handling means attached to the structure like overhead travelling cranes. From the PS accelerator to the LHC, handling systems have been developed at CERN to fit with these particular working conditions. This paper will expose the operating conditions of the main transport equipments used at CERN in PS, SPS and LHC tunnels
Breeding ecology of the Iranian ground jay (Podoces pleskei)
Although Podoces pleskei is the only endemic bird of Iran, little information exists on its ecological features, population dynamics and threats that concern it. This species occurs in desert and semi desert areas, mostly on the Iranian plateau, though its range spreads southeast ward to the Iran- Pakistan border. In this research, a total of 52 nests were studied in three locations, the “Ghare Tappe”, “Marvast” and “Mehrano” region, from 2005 to 2008. Breeding habits, nest characteristics, hatching features, clutch size, length of incubation time, nesting period and features of the chicks were observed in the three locations and were analyzed using analysis of variance (ANOVA). To compare breeding success among the three study areas, Z test was applied. This bird builds its nest at the top of and within the denser parts of plants, particularly Atraphaxis spinosa, Ephedra intermedia and Zygophyllum eurypterum. At times of danger, they hide beneath shrubs. Z-tests showed that the breeding success of this bird varied between Marvast and Mehrano. The greatest cause of nest failure and chick mortality was the transcaspian desert monitor (Varanus griseus caspius), which feeds on the eggs and chicks.Key words: Breeding ecology, Pleske’s ground jay, nest characteristics, clutch size, nest success, threat
Overview of the Large Hadron Collider cryo-magnets logistics
More than 1700 superconducting cryo-magnets have to be installed in the Large Hadron Collider tunnel. The long, heavy and fragile LHC cryo-magnets are difficult to handle and transport in particular in the LEP tunnel environment originally designed for smaller, lighter LEP magnets. An installation rate of more than 20 cryo-magnets per week is needed to cope with the foreseen LHC installation end date. The paper gives an overview of the transport and installation sequence complexity, from the storage area at the surface to the cryo-magnet final position in the tunnel. The success of this task depends on a series of independent factors that have to be considered at the same time. The equipment needed for the transport and tunnel installation of the LHC cryo-magnets is briefly described. The manpower and equipment organisation as well as the challenges of logistics are then detailed. The paper includes conclusions and some of the lessons learned during the first phase of the LHC cryo-magnets installation
Positive Study on the Tactics How to Tackle Section 337 Investigation in USA —— From the Answer Examples of Chinese Export Enterprises
当前美国337条款调查已经成为中国出口产品进入美国市场的重要障碍。本文以中国出口企业历年来的应诉实例为切入点,探讨这些案例所反映的调查特征,发现存在的主要问题,结合法律规定和具体案例研究“337调查”程序与实体方面的应对策略,从具体案例中吸取教训,总结经验。取材主要是涉中案例,更具说服力,特别是成功案例,希望借此增强国内企业应诉的信心。 除前言和结论外,本文共分四章,主要内容如下: 第一章介绍了中国出口企业应诉美国“337调查”的现状和存在的问题。详细统计了历年来中国企业的出庭情况,案件的审理结果以及产生这些结果的主要原因。虽然整体来看,中国企业的应对情况并不理想,但出庭案件绝大部分都没有...Currently Section 337 investigation of USA has already become an obstacle to Chinese products to enter into American market. The text takes the answer examples of Chinese enterprises as cut-in point, discusses the character and problems reflecting from these cases, combines rules of law and case study to research the countermeasures about procedure and entity aspects of Section 337 Investigation, ...学位:法学硕士院系专业:法学院法律系_民商法学(含劳动法学、社会保障法学)学号:20040804
Modification of Salmonella Typhimurium Motility by the Probiotic Yeast Strain Saccharomyces boulardii
BACKGROUND: Motility is an important component of Salmonella enterica serovar Typhimurium (ST) pathogenesis allowing the bacteria to move into appropriate niches, across the mucus layer and invade the intestinal epithelium. In vitro, flagellum-associated motility is closely related to the invasive properties of ST. The probiotic yeast Saccharomyces boulardii BIOCODEX (S.b-B) is widely prescribed for the prophylaxis and treatment of diarrheal diseases caused by bacteria or antibiotics. In case of Salmonella infection, S.b-B has been shown to decrease ST invasion of T84 colon cell line. The present study was designed to investigate the impact of S.b-B on ST motility. METHODOLOGY/PRINCIPAL FINDINGS: Experiments were performed on human colonic T84 cells infected by the Salmonella strain 1344 alone or in the presence of S.b-B. The motility of Salmonella was recorded by time-lapse video microscopy. Next, a manual tracking was performed to analyze bacteria dynamics (MTrackJ plugin, NIH image J software). This revealed that the speed of bacterial movement was modified in the presence of S.b-B. The median curvilinear velocity (CLV) of Salmonella incubated alone with T84 decreased from 43.3 µm/sec to 31.2 µm/sec in the presence of S.b-B. Measurement of track linearity (TL) showed similar trends: S.b-B decreased by 15% the number of bacteria with linear tract (LT) and increased by 22% the number of bacteria with rotator tract (RT). Correlation between ST motility and invasion was further established by studying a non-motile flagella-deficient ST strain. Indeed this strain that moved with a CLV of 0.5 µm/sec, presented a majority of RT and a significant decrease in invasion properties. Importantly, we show that S.b-B modified the motility of the pathogenic strain SL1344 and significantly decreased invasion of T84 cells by this strain. CONCLUSIONS: This study reveals that S.b-B modifies Salmonella's motility and trajectory which may account for the modification of Salmonella's invasion
Patterns of ash (Fraxinus excelsior L.) colonization in mountain grasslands: the importance of management practices
International audienceWoody colonization of grasslands is often associated with changes in abiotic or biotic conditions or a combination of both. Widely used as fodder and litter in the past traditional agro-pastoral system, ash (Fraxinus excelsior L.) has now become a colonizing species of mountain grasslands in the French Pyrenees. Its present distribution is dependent on past human activities and it is locally controlled by propagule pressure and abiotic conditions. However, even when all favourable conditions are met, all the potentially colonizable grasslands are not invaded. We hypothesize that management practices should play a crucial role in the control of ash colonization. From empirical field surveys we have compared the botanical composition of a set of grasslands (present and former) differing in management practices and level of ash colonization. We have displayed a kind of successional gradient positively linked to both ash cover and height but not to the age of trees. We have tested the relationships between ash presence in grassland and management types i.e. cutting and/or grazing, management intensity and some grassland communities' features i.e. total and local specific richness and species heterogeneity. Mixed use (cutting and grazing) is negatively linked to ash presence in grassland whereas grazing alone positively. Mixed use and high grazing intensity are directly preventing ash seedlings establishment, when low grazing intensity is allowing ash seedlings establishment indirectly through herbaceous vegetation neglected by livestock. Our results show the existence of a limit between grasslands with and without established ashes corresponding to a threshold in the intensity of use. Under this threshold, when ash is established, the colonization process seems to become irreversible. Ash possesses the ability of compensatory growth and therefore under a high grazing intensity develops a subterranean vegetative reproduction. However the question remains at which stage of seedling development and grazing intensity these strategies could occur
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