3,072 research outputs found
The ATLAS RPC ROD for Super LHC
The number of interactions per bunch crossing for the upgrade of the Large Hadron Collider is expected to be ten times greater than the actual one. As a consequence, the ATLAS detector for SLHC foresees the use of a larger number of readout channels and also a new trigger level is under development. In order to face with such issue, we developed a new architecture for the Read Out Driver (ROD) for the ATLAS RPC Muon Spectrometer in the barrel region. Presently, each ROD board receives ATLAS RPC Muon readout data and arranges all the data fragments of a sector of the spectrometer in a unique event, sending it to the next acquisition systems. Our new design is based on the new generation Xilinx Virtex5 FPGA and it works with a clock frequency six times greater than the actual bunch crossing rate of the LHC. We also implemented the output channel of the ROD, presently based on S-Link protocol, by using the GTP transceivers inside the FPGA. We present an overview of our design, focusing on the newly added hardware features
Experimental investigation of SO2 poisoning in a Molten Carbonate Fuel Cell operating in CCS configuration
[EN] One of the most interesting innovations in the CCS (Carbon Capture and Storage) field is the use of MCFCs as carbon dioxide concentrators, feeding their cathode side (or air side) with the exhaust gas of a traditional power plant. The feasibility of this kind of application depends on the resistance of the MCFC to air-side contaminants, with particular attention to SO2. The aim of this work is to investigate the effects of poisoning when sulphur dioxide is added to the cathodic stream in various concentrations and in different operating conditions. This study was carried out operating single cells (80 cm(2)) with a cathodic feeding composition simulating typical flue gas conditions, i.e. N-2, H2O, O-2 and CO2 in 73:9:12:6 mol ratio as reference mixture. On the anodic side a base composition was chosen with H-2, CO2 and H2O in 64:16:20 mol ratio. Starting from these reference mixtures, the effect of single species on cell poisoning was experimentally investigated considering, as main parameters chosen for the sensitivity analysis, SO2 (0-24 ppm) and CO2 (4-12%) content in the cathodic feeding mixture, H-2 (40-64%) content in the anodic stream as well as the operating temperature (620-680 degrees C). Results showed that degradation caused by SO2 poisoning is strongly affected by the operating conditions. Data gathered during this experimental campaign will be used in a future work to model the poisoning mechanisms through the definition of MCFC electrochemical kinetics which take into account the SO2 effects. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.The work was partly supported by H2FC European Infrastructure Project (Integrating European Infrastructure to support science and development of Hydrogen and Fuel Cell Technologies towards European Strategy for Sustain-able Competitive and Secure Energy) Theme [INFRA-2011-1.1.16.], Grant agreement 284522.Della Pietra, M.; Discepoli, G.; Bosio, B.; Mcphail, S.; Barelli, L.; Bidini, G.; Ribes-Greus, A. (2016). Experimental investigation of SO2 poisoning in a Molten Carbonate Fuel Cell operating in CCS configuration. International Journal of Hydrogen Energy. 41(41):18822-18836. https://doi.org/10.1016/j.ijhydene.2016.05.147S1882218836414
Designing potentials by sculpturing wires
Magnetic trapping potentials for atoms on atom chips are determined by the
current flow in the chip wires. By modifying the shape of the conductor we can
realize specialized current flow patterns and therefore micro-design the
trapping potentials. We have demonstrated this by nano-machining an atom chip
using the focused ion beam technique. We built a trap, a barrier and using a
BEC as a probe we showed that by polishing the conductor edge the potential
roughness on the selected wire can be reduced. Furthermore we give different
other designs and discuss the creation of a 1D magnetic lattice on an atom
chip.Comment: 6 pages, 8 figure
Study of Chinese Insurance Company’s Risk Estimation Index System
自从1990年以来,日本多家保险公司因资不抵债相继破产,不仅在国际社会造成了极大的震动,也给我国保险业敲响了警钟:保险公司在经营风险产品的同时,应加强对自身风险的评估。自从我国加入WTO后,保险业受到了巨大的冲击,加强对我国保险公司风险评估指标体系的研究便具有十分重要的意义。首先,对保险公司风险评估指标体系的研究,能为量化保险公司经营风险提供依据。其次,对保险公司风险评估指标体系的研究,有利于保险公司加强风险管理。 本文选择保险公司风险评估指标作为研究的重点,详细介绍了保险公司风险评估指标体系的内容、评价及在我国保险市场上的应用,并选取了四家保险公司近年来的数据,用IRIS指标体系做实证研究...Since 1990, some insurance companies of Japanese have been bankrupted. It made a big ring to the international financial market and Chinese insurance market: Insurance companies should pay more attention to its risk evaluation. After China’s entry into the WTO, some industries fell under big impact, especially the insurance industry. So the study of risk evaluation became more and more important t...学位:经济学硕士院系专业:经济学院财政金融系_金融学(含保险学)学号:20044202
Predictors of carotid occlusion intolerance?during proximal protected?carotid artery?stenting.
OBJECTIVES:
The aim of this study was to identify predictors of occlusion intolerance (OI) developing during proximal protected carotid artery stenting (CAS).
BACKGROUND:
The use of proximal embolic protection devices, such as endovascular occlusion, during CAS has been demonstrated to be particularly safe and effective. However, endovascular occlusion can expose the ipsilateral hemisphere to hypoperfusion and produce transient neurological symptoms (OI).
METHODS:
From March 2010 to March 2012, 605 consecutive patients underwent proximal protected CAS at our institution. To identify independent predictors of OI, a multivariate logistic regression model was developed that included all patients' clinical/angiographic and procedural characteristics.
RESULTS:
OI developed in a total of 184 patients (30.4%). Compared with patients in whom OI did not develop, those who experienced OI had lower occlusion pressure (OP) (42.3 ± 12.7 mm Hg vs. 61.9 ± 15.4 mm Hg, p < 0.001). Receiver-operating characteristic curve analysis demonstrated that OP was the most consistent predictor of OI with a C-statistic of 0.85 (95% confidence interval [CI]: 0.82 to 0.88) with best cutoff being ≤40 mm Hg (sensitivity, 68.5%; specificity, 93.3%). By logistic regression analysis, the most powerful independent predictor of OI developing was an OP ≤40 mm Hg (odds ratio: 33.2, 95% CI: 19.1 to 57.7) and the most powerful clinical predictor of such OP was the presence of contralateral internal carotid artery occlusion (odds ratio: 3.1, 95% CI: 1.5 to 6.2).
CONCLUSIONS:
OI may occur in as many as one-third of the patients undergoing proximal protected CAS. This event is more common in those patients with an OP ≤40 mm Hg. Patients presenting with concomitant occlusion of the contralateral internal carotid artery more frequently have an OP ≤40 mm Hg
Upper bounds for the eigenvalues of Hessian equations
We prove some upper bounds for the Dirichlet eigenvalues of a class of fully
nonlinear elliptic equations, namely the Hessian equationsComment: 15 pages, 1 figur
Maximum Entropy Models with Inequality Constraints: A Case Study on Text Categorization
Ageing test of the ATLAS RPCs at X5-GIF
An ageing test of three ATLAS production RPC stations is in course at X5-GIF,
the CERN irradiation facility. The chamber efficiencies are monitored using
cosmic rays triggered by a scintillator hodoscope. Higher statistics
measurements are made when the X5 muon beam is available. We report here the
measurements of the efficiency versus operating voltage at different source
intensities, up to a maximum counting rate of about 700Hz/cm^2. We describe the
performance of the chambers during the test up to an overall ageing of 4 ATLAS
equivalent years corresponding to an integrated charge of 0.12C/cm^2, including
a safety factor of 5.Comment: 4 pages. Presented at the VII Workshop on Resistive Plate Chambers
and Related Detectors; Clermont-Ferrand October 20th-22nd, 200
Complex patterns of chromosome 11 aberrations in myeloid malignancies target CBL, MLL, DDB1 and LMO2.
Variability Measures of Positive Random Variables
During the stationary part of neuronal spiking response, the stimulus can be encoded in the firing rate, but also in the statistical structure of the interspike intervals. We propose and discuss two information-based measures of statistical dispersion of the interspike interval distribution, the entropy-based dispersion and Fisher information-based dispersion. The measures are compared with the frequently used concept of standard deviation. It is shown, that standard deviation is not well suited to quantify some aspects of dispersion that are often expected intuitively, such as the degree of randomness. The proposed dispersion measures are not entirely independent, although each describes the interspike intervals from a different point of view. The new methods are applied to common models of neuronal firing and to both simulated and experimental data
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