65 research outputs found

    Observation of Electroweak Production of a Same-Sign W Boson Pair in Association with Two Jets in pp Collisions root s=13 TeV with the ATLAS Detector

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    This Letter presents the observation and measurement of electroweak production of a same-sign W boson pair in association with two jets using 36.1     fb − 1 of proton-proton collision data recorded at a center-of-mass energy of √ s = 13     TeV by the ATLAS detector at the Large Hadron Collider. The analysis is performed in the detector fiducial phase-space region, defined by the presence of two same-sign leptons, electron or muon, and at least two jets with a large invariant mass and rapidity difference. A total of 122 candidate events are observed for a background expectation of 69 ± 7 events, corresponding to an observed signal significance of 6.5 standard deviations. The measured fiducial signal cross section is σ fid = 2.89 + 0.51 − 0.48 ( stat ) + 0.29 − 0.28 ( syst )     fb

    Ultrahigh energy neutrinos at the pierre auger observatory

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    The observation of ultrahigh energy neutrinos (UHEs) has become a priority in experimental astroparticle physics. UHEs can be detected with a variety of techniques. In particular, neutrinos can interact in the atmosphere (downward-going ) or in the Earth crust (Earth-skimming ), producing air showers that can be observed with arrays of detectors at the ground. With the surface detector array of the Pierre Auger Observatory we can detect these types of cascades. The distinguishing signature for neutrino events is the presence of very inclined showers produced close to the ground (i.e., after having traversed a large amount of atmosphere). In this work we review the procedure and criteria established to search for UHEs in the data collected with the ground array of the Pierre Auger Observatory.This includes Earth-skimming as well as downward-going neutrinos. No neutrino candidates have been found, which allows us to place competitive limits to the diffuse flux of UHEs in the EeV range and above

    Electron reconstruction and identification efficiency measurements with the ATLAS detector using the 2011 LHC proton–proton collision data

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    Many of the interesting physics processes to be measured at the LHC have a signature involving one or more isolated electrons. The electron reconstruction and identification efficiencies of the ATLAS detector at the LHC have been evaluated using proton–proton collision data collected in 2011 at s√=7 TeV and corresponding to an integrated luminosity of 4.7 fb −1. Tag-and-probe methods using events with leptonic decays of W and Z bosons and J/ψ mesons are employed to benchmark these performance parameters. The combination of all measurements results in identification efficiencies determined with an accuracy at the few per mil level for electron transverse energy greater than 30 GeV

    Azimuthal anisotropy in Cu plus Au collisions at root s(NN)=200 GeV

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    Microbiological Examination and Determination of the Risk of Caries Development in a Patient with Esophageal Reflux Disease

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    The main oral manifestation of gastroesophageal reflux disease is dental erosion. The very few studies have evaluated the damage and changes of soft, periodontal tissues and microbial flora. The aim of this study was to measure mutant streptococci and lactobacilli counts as predisposing factors to dental caries using Dentocult SMÂź and Dentocult LBÂź tests.The results showed lower counts of Streptocococcus mutans and lactobacilli, that means lower predisposing factor to dental caries. These results suggest that demineralization of hard dental tissues is without cariogenic plaque

    Hydraulic Hybrid Propulsion for Heavy Vehicles: Combining the Simulation and Engine-In-the-Loop Techniques to Maximize the Fuel Economy and Emission Benefits

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    The global energy situation, the dependence of the transportation sector on fossil fuels, and a need for a rapid response to the global warming challenge, provide a strong impetus for development of fuel efficient vehicle propulsion. The task is particularly challenging in the case of trucks due to severe weight/size constraints. Hybridization is the only approach offering significant breakthroughs in near and mid-term. In particular, the series configuration decouples the engine from the wheels and allows full flexibility in controlling the engine operation, while the hydraulic energy conversion and storage provides exceptional power density and efficiency. The challenge stems from a relatively low energy density of the hydraulic accumulator. This places particular emphasis on development of the supervisory controller. The conventional wisdom is to operate the engine at the “sweet spot”, but the aggressive pursuit of engine efficiency as the sole objective can lead to frequent and rapid diesel engine transients, thus causing an adverse affect on the soot emissions and driver feel. Therefore, we propose a comprehensive methodology for considering a combined hybrid system fuel-economy and emissions objective. The fuel economy is addressed with the simulation-based approach, while investigating the impact of engine transients on particulate emission relies on the Engine-In-the-loop (EIL) capability. The EIL study confirms advantages of a modulated state-of-charge control over the thermostatic approach, and demonstrates the ability of the Series Hydraulic Hybrid to improve the fuel economy of the medium truck by 72%, while reducing the particulate emission by 74% compared to the conventional baseline over the city driving schedule

    Varicella zoster infection in renal transplant recipients: prevalence, complications and outcome

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    Varicella zoster virus (VZV) is an important pathogen after renal transplantation. In the present study, we examined the prevalence, clinical presentation and outcome of VZV infections in renal transplant recipients. Charts and medical records of adult renal allotransplant recipients were investigated to find patients with VZV infection. From December 1972 until July 2010, 1,139 patients received kidney allograft at our institution. VZV infection was diagnosed in 40 patients (3.51%). 28 patients (70%) had intensified immunosuppression prior to VZV infection occurrence. Median time of onset was 2.13 years after transplantation (range 9 days to 19.2 years). 35 patients developed VZV during the first post-transplant year (median 0.61 years). Four patients developed VZV infection more than 12 years after transplantation. 33 patients (82.5%) had dermatomal distribution, 5 (12.5%) disseminated herpes zoster (HZ), and 2 patients (5%) who were VZV IgG-negative before transplantation, developed chickenpox. Immunosuppression was reduced and patients received acyclovir. Cutaneous scarring was recorded in 7 cases (17.5%). Two patients developed post-herpetic neuralgia, which was accompanied by scarring and skin depigmentation in 1 of them. Five patients (12.5%) experienced relapse of HZ. Timely initiation of therapy may prevent development of complications and the visceral form of disease. Based on our experience with development of chickenpox, we suggest active immunization for all seronegative patients before organ transplantation

    Characterizing one-day missions of PHEVs based on representative synthetic driving cycles

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    This paper investigates series plug-in hybrid electric vehicle (PHEV) behavior during one-day with synthesized representative one-day missions. The amounts of electric energy and fuel consumption are predicted to assess the PHEV impact on the grid with respect to the driving distance and different charging scenarios: (1) charging overnight, (2) charging whenever possible. The representative cycles are synthesized using the extracted information from the real-world driving data in Southeast Michigan gathered through the Field Operational Tests (FOT) conducted by the University of Michigan Transportation Research Institute (UMTRI). The real-world driving data include 4,409 trips covering 830 independent days and temporal distributions of departure and arrival times. The sample size is large enough to represent real-world driving. The driving cycle synthesis approach proposed by Lee, and Filipi 2,3 based on a stochastic process and subsequent validation procedure is used to create real-world driving cycles. To cover the entire range of real-world driving distance, ten synthetic cycles are created ranging from 4.78 miles to 40.71 miles following the real-world driving distance distribution. The PHEV behavior over one-day is characterized through a simulation based approach. The PHEV simulation is executed using Matlab simulink based Powertrain System Analysis Toolkit (PSAT) developed by Argonne National Laboratory (ANL) and in-house Matlab codes. The amounts of the electricity and fuel consumptions over one-day are predicted under different driving distances and different charging scenarios. The prediction of the PHEV behavior can be directly linked to the loads on the local distribution network. © 2011 SAE International

    Stochastic modeling for studies of real-world PHEV usage: driving schedule and daily temporal distributions

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    Daily driving missions provide the fundamental information required to predict the impact of the plug-in hybrid electric vehicle (PHEV) on the grid. In this paper, we propose a statistical modeling approach of daily driving mission sets. The approach consists of temporal distribution modeling and the synthesis of individual representative cycles. The proposed temporal distribution model can capture departure and arrival time distributions with a small number of samples by statistically relating the distributions. Then, representative naturalistic cycles are constructed through a stochastic process and a subsequent statistical analysis with respect to driving distance. They are randomly assigned to the temporal distribution model to build up complete daily driving missions. The proposed approach enables the assessment of the impact on the grid of a large-scale deployment of PHEVs using a small number of simulations capturing real-world driving patterns and the temporal distributions of departure and arrival times. © 2012 IEEE
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