1,022 research outputs found

    A study of materials used for muon chambers at the CMS Experiment at the LHC: interaction with gas, new materials and new technologies for detector upgrade

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    This thesis lays its foundation in both technological and theoretical stud- ies carried out between several aspects of applied engineering. There are several original contributions within the material science. The first is the detailed studies about the CMS RPC gas filters, which required an intense 3 years data-taking and ended up with a complete characterization of purifier materials. On top of this a stable ad − hoc setup (GGM) has been devel- oped for the CMS Experiment in order to monitor the RPC muon chamber working point. Finally a complete new detector has been designed, build and tested using new technology and new electronics establishing the word’s record in size for this kind of detector, which is taken under consideration for the upgrade of the high-η region of the CMS Experiment

    SYSTEM FOR ANALYZING FOOD CONSUMPTION AND WASTE

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    The present invention relates to monitoring, analyzing, and giving feed- back based on food consumption and waste, specifically (but not exclusively) that of consumers in a cafeteria/dining hall setting. It can be used to observe and address overall trends as well as individual behaviors

    Low-mass GEM detector with radial zigzag readout strips for forward tracking at the EIC

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    We present design and construction of a large low-mass Triple-GEM detector prototype for forward tracking at a future Electron-Ion Collider. In this environment, multiple scattering of forward and backward tracks must be minimized so that electron tracks can be cleanly matched to calorimeter clusters and so that hadron tracks can efficiently seed RICH ring reconstruction for particle identification. Consequently, the material budget for the forward tracking detectors is critical. The construction of the detector builds on the mechanical foil stretching and assembly technique pioneered by CMS for the muon endcap GEM upgrade. As an innovation, this detector implements drift and readout electrodes on thin large foils instead of on PCBs. These foils get stretched mechanically together with three GEM foils in a single stack. This reduces the radiation length of the total detector material in the active area by a factor seven from over 4% to below 0.6%. It also aims at improving the uniformity of drift and induction gap sizes across the detector and consequently signal response uniformity. Thin outer frames custom-made from carbon-fiber composite material take up the tension from the stretched foil stack and provide detector rigidity while keeping the detector mass low. The gas volume is closed with thin aluminized polyimide foils. The trapezoidal detector covers an azimuthal angle of 30.1 degrees and a radius from 8 cm to 90 cm. It is read out with radial zigzag strips with pitches of 1.37 mrad at the outer radius and 4.14 mrad at the inner radius that reduce the number of required electronics channels and associated cost while maintaining good spatial resolution. All front-end readout electronics is located away from the active area at the outer radius of the trapezoid.Comment: 4 pages, 7 figures, submitted to conference record of 2017 IEEE Nuclear Science Symposium, Atlanta, G

    SiOx coated plastic fiber optic sensor for gas monitoring in RPC

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    This paper describes the development of a sensor designed to monitor the closed loop recirculation gas system of the Resistive Plate Counter (RPC) muon detectors which are used for the Compact Muon Solenoid (CMS) experiment installed at the Large Hadron Collider (LHC) accelerator of the European Center for Nuclear Research (CERN). The sensor is designed to detect low concentrations of hydrogen fluoride (HF) in the gas mixtures and employs a plastic optic fiber (POF) which is covered with a thin layer of a glass-like material. The fluoride ions attacks the glass and alters the fiber transmission capability so that the detection simply requires a LED and a photodiode. The coating is obtained by means of a low pressure plasma enhanced chemical vapor deposition (PECVD) that allows the glass-like film to be deposited at low temperature without damaging the fiber core

    Construction and Performance of Large-Area Triple-GEM Prototypes for Future Upgrades of the CMS Forward Muon System

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    At present, part of the forward RPC muon system of the CMS detector at the CERN LHC remains uninstrumented in the high-\eta region. An international collaboration is investigating the possibility of covering the 1.6 < |\eta| < 2.4 region of the muon endcaps with large-area triple-GEM detectors. Given their good spatial resolution, high rate capability, and radiation hardness, these micro-pattern gas detectors are an appealing option for simultaneously enhancing muon tracking and triggering capabilities in a future upgrade of the CMS detector. A general overview of this feasibility study will be presented. The design and construction of small (10\times10 cm2) and full-size trapezoidal (1\times0.5 m2) triple-GEM prototypes will be described. During detector assembly, different techniques for stretching the GEM foils were tested. Results from measurements with x-rays and from test beam campaigns at the CERN SPS will be shown for the small and large prototypes. Preliminary simulation studies on the expected muon reconstruction and trigger performances of this proposed upgraded muon system will be reported.Comment: 7 pages, 25 figures, submitted for publication in conference record of the 2011 IEEE Nuclear Science Symposium, Valencia, Spai

    Test beam results of the GE1/1 prototype for a future upgrade of the CMS high-η\eta muon system

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    Gas Electron Multipliers (GEM) are an interesting technology under consideration for the future upgrade of the forward region of the CMS muon system, specifically in the 1.6<η<2.41.6<| \eta |<2.4 endcap region. With a sufficiently fine segmentation GEMs can provide precision tracking as well as fast trigger information. The main objective is to contribute to the improvement of the CMS muon trigger. The construction of large-area GEM detectors is challenging both from the technological and production aspects. In view of the CMS upgrade we have designed and built the largest full-size Triple-GEM muon detector, which is able to meet the stringent requirements given the hostile environment at the high-luminosity LHC. Measurements were performed during several test beam campaigns at the CERN SPS in 2010 and 2011. The main issues under study are efficiency, spatial resolution and timing performance with different inter-electrode gap configurations and gas mixtures. In this paper results of the performance of the prototypes at the beam tests will be discussed

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

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    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

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    One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI
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