164 research outputs found

    Measurements of the LHC longitudinal resistive impedance with beam

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    The resistive part of the longitudinal impedance contributes to the heat deposition on different elements in the LHC ring including the beam screens, where it has to be absorbed by the cryogenic system and can be a practical limitation for the maximum beam intensity. In this paper, we present the first measurements of the LHC longitudinal resistive impedance with beam, done through synchronous phase shift measurements duringMachine Development sessions in 2012. Synchronous phase shift is measured for different bunch intensities and lengths using the high-precision LHC Beam Phase Module and then data are post-processed to further increase the accuracy. The dependence of the energy loss per particle on bunch length is then obtained and compared with the expected values found using the LHC impedance model

    Experimental Studies of Carbon Coatings as Possible Means of Suppressing Beam Induced Electron Multipacting in the CERN SPS

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    Electron cloud build-up is a major limitation for the operation of the SPS with LHC beam above nominal intensity. These beams are envisaged in the frame of the LHC luminosity upgrade and will be available from the new injectors LPSPL and PS2. A series of studies have been conducted in order to identify possible means to suppress electron multipacting by coating the existing SPS vacuum chambers with thin films of amorphous carbon. After a description of the experimental apparatus installed in the SPS, the results of the tests performed with beam in 2008 will be presented

    Epidemiological Situation on Crimean-Congo Hemorrhagic Fever in the Russian Federation in 2012 and Prognosis for 2013

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    Represented is epidemiological evaluation of the morbidity rate as regards Crimean-Congo hemorrhagic fever (CCHF) in Russia in 2012. Summarized are the results of epizootiological surveillance over the territory of CHF natural focus in the South of European part of Russia. Forecast of CCHF epidemiological situation development for 2013 is made based on the epizootiological monitoring data

    EPIDEMIOLOGICAL SITUATION ON CRIMEAN HEMORRHAGIC FEVER IN THE RUSSIAN FEDERATION IN 2016, AND PROGNOSIS FOR 2017

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    Abstract. This paper presents analysis of epidemiological situation on Crimean hemorrhagic fever (CHF) in Russia in 2016. Summarized are the results of epizootiological survey of the territory of the natural CHF focus in the south of the European part of Russia, discussed are the results of genetic typing of CCHFV RNA isolates. In 2016, the Russian Federation reported 162 cases of CHF. Increase in the incidence of CHF occurred in the Astrakhan, Volgograd Regions, Republic of Kalmykia, and Stavropol Territory. For the first time CHF case was identified in Kabardino-Balkar Republic. In 2016 in stationary points for the long-term observation of the natural CHF focus, high abundance rates of larvae and nymphs of H. marginatum remain. In case of successful Ixodidae ticks wintering and late onset of the hot and dry season in the summer, 2017, there is probability that high numbers of H. marginatum will be retained and the period of the imago activity is prolonged, which may in its turn  contribute to the increase in CHF morbidity rates

    Comparison of open femoral exposure and percutaneous access in endovascular reconstruction of the thoracic aorta: a two-center retrospective study

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    Aim. To analyze the efficacy and safety of the percutaneous transfemoral puncture technique for TEVAR (thoracis endovascular aortic repair).Material and methods. The retrospective study included 89 patients with aortic pathologies, for whom endovascular repair was performed: 51 patients (57%) with aortic dissection (type I DeBakey — 30 cases (58,8%) and type III — 21 (41,2%)), 38 (43%) patients with aortic aneurism. 82% of patients were male, the median age was 57 years (minimum age 17 years, maximum age 75 years). All patients were divided into two groups: in the first group (48 patients) endovascular aortic repair was performed under endotracheal anesthesia with open femoral exposure of the common femoral artery (CFA), in the second group (41 patients) — by percutaneous puncture method under local anesthesia. Technical and clinical aspects of procedures were analyzed.Results. Technical success of endovascular repair was achieved in 100% cases in both groups. The duration of the operation in the group with percutaneous access was statically significantly shorter (120 (94-150) minutes vs 87(60-120) minutes, p=0,001). Also, the time spent by patients in the intensive care unit and the period of hospitalization (18 (14-22) hours versus 1 (0-3) hours, p=0,001; 5 (4-6) days versus 4 (3-5) days, p=0,03) was shorter. In the open access group 2 (4,2%) patients developed access-related complications - acute thrombosis of the common femoral artery and hematoma of the postoperative wound, which required additional surgical aid - thrombectomy from the CFA, the second patient had evacuation of the hematoma of the postoperative wound. Cite-related complications in the second group were not observed. No major complications including neurological deficits and hospital mortality were observed in both groups.Conclusions. Thoracic endovascular aortic repair (TEVAR) using percutaneous access under local anesthesia in stable patients has proven to be safe and effective. The operation time is significantly reduced and this approach in most cases eliminates the need for the patient to stay in the intensive care unit in the early postoperative period. Possibility of early mobilization of the patient appears with reducing of the duration of hospitalization

    Analysis of Crimean Hemorrhagic Fever Morbidity Rates in the Russian Federation in 2017 and Prognosis for 2018

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    This paper presents the analysis of Crimean hemorrhagic fever (CHF) morbidity rates in Russia in 2017; summarized are the results of epidemiological survey of the territory of the natural CHF focus in the south of the European part of Russia, discussed are the results of genetic typing of CCHF virus isolates. In 2017, the Russian Federation reported 78 cases of CHF. Decrease in the incidence of CHF occurred in the Volgograd Region, Stavropol Territory, Astrakhan Region, Republic of Kalmykia, and Rostov Region. For the first time since 1967, CHF case has been identified in Crimea Republic. It is expected that the level of epizootic activity of CHF natural focus in Russia in 2018 will be at least equal to 2017. In case of favorable for Ixodidae ticks weather and climate conditions of the winter 2017–2018, as well as untimely acaricidal treatments, the number of Ixodidae ticks may increase, which along with the high scale of CCHF virus infection in ticks, will contribute to the increase in CHF incidence

    First Beam Commissioning of the 400 MHz LHC RF System

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    Hardware commissioning of the LHC RF system was successfully completed in time for first beams in LHC in September 2008. All cavities ware conditioned to nominal field, power systems tested and all Low level synchronization systems, cavity controllers and beam control electronics were tested and calibrated. Beam was successfully captured in ring 2, cavities phased, and a number of initial measurements made. These results are presented and tests and preparation for colliding beams in 2009 are outlined
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