Multigap Resistive Plate Chambers (MRPCs) are often used as time-of-flight (TOF) detectors for high-energy physics and nuclear experiments thanks to their excellent time accuracy. For the Compressed ...Baryonic Matter (CBM) TOF system, MRPCs are required to work at particle fluxes on the order of 1–10kHz/cm2 for the outer region and 10–25kHz/cm2 for the central region. Better time resolution will allow particle identification with TOF techniques to be performed at higher momenta. From our previous studies, a time resolution of 25ps has been obtained with a 20-gap MRPC of 140μm gap size with enhanced rate capability. By using a new type of commercially available thin low-resistivity glass, further improvement MRPC rate capability is possible. In order to study the rate capability of the 10-gap MRPC built with this new low-resistivity glass, we have performed tests using the continuous electron beam at ELBE. This 10-gap MRPC, with 160μm gaps, reaches 97% efficiency at 19.2kV and a time resolution of 36ps at particle fluxes near 2kHz/cm2. At a flux of 100kHz/cm2, the efficiency is still above 95% and a time resolution of 50ps is obtained, which would fulfil the requirement of CBM TOF system.
Background: Hepatitis C Virus (HCV) infection is a public health problem worldwide, with particular relevance in multi-transfusedpatients given that HCV is principally transmitted by exposure to ...infected blood.
Study design: Between February and September 2003 a cross-sectional study was carried out in four hospital centres in Bogotá and Medellin, Colombia, to determine the risk factors for HCV infection in 500 multi-transfused patients.
Results: The study population was distributed in five groups: haemophilia, haemodyalsis, acute bleeding, ontological illnesses and sickle cell disease or thalassemia. Serum samples from patients were tested for HCV antibodies (Asxym™, Abbott). An overall prevalence (9.0%; 95% confidence interval (CI): 6.4–11.6) (45/500) of HCV infection was found. Anti-HCV antibodies were detected in 32.2% of patients with haemophilia, 6.1% of patients undergoing haemodialysis, 7.1% of patients with sickle cell disease or thalassemia, 2.6% of patients with acute bleeding and 3.4% of patients with ontological or hematological diseases.
The main risk factors associated with infection by HCV were: to be hemophilic (odds ratio, OR = 18.03; 95% Cl: 3.96–114.17), havingreceived transfusions before 1995 (OR = 12.27; 95% Cl: 5.57–27.69), and having received more than 48 units of blood components (OR = 6.08; 95% CI: 3.06–12.1). In the multivariate analysis, only the year of transfusions (before 1995) remained significantly associated with risk of infection by HCV.
Conclusions: The data show a 3-fold reduction in the infection risk between 1993 and 1995, when the serological screening for HCVin blood donors was being introduced. A reduction greater than 90% was achieved by 1995 when the screening coverage reached 99%.
In this article, two image reconstruction techniques for radiography and tomography using cosmic ray muons are presented. The simulation is carried out using the Geant4 package, simulating a multiple ...coincidence system of four RPCs (Resistive Plate Chambers). The reconstruction techniques presented are based on particle trajectory reconstruction and localization of a single center of dispersion. Two functional cases are displayed for each technique.
The production of D super(c)- and D super(0)-mesons has been measured with the ZEUS detector at HERA using an integrated luminosity of 133.6 pb super(-1). The measurements cover the kinematic range ...5<Q super(2)<1000 GeV super(2), 0.02<y<0.7, 1.5<p sub(T) super(D )<15 GeV and
Inclusive K_{S};{0}K_{S};{0} production in ep collisions at the DESY ep collider HERA was studied with the ZEUS detector using an integrated luminosity of 0.5 fb;{-1}. Enhancements in the mass ...spectrum were observed and are attributed to the production of f_{2}(1270)/a_{2};{0}(1320), f_{2};{'}(1525) and f_{0}(1710). Masses and widths were obtained using a fit which takes into account theoretical predictions based on SU(3) symmetry arguments, and are consistent with the Particle Data Group values. The f_{0}(1710) state, which has a mass consistent with a glueball candidate, was observed with a statistical significance of 5 standard deviations. However, if this state is the same as that seen in gammagamma-->K_{S};{0}K_{S};{0}, it is unlikely to be a pure glueball state.
The muon system of the CERN Compact Muon Solenoid (CMS) experiment includes more than a thousand Resistive Plate Chambers (RPC). They are gaseous detectors operated in the hostile environment of the ...CMS underground cavern on the Large Hadron Collider where pp luminosities of up to \(2\times 10^{34}\) \(\text{cm}^{-2}\text{s}^{-1}\) are routinely achieved. The CMS RPC system performance is constantly monitored and the detector is regularly maintained to ensure stable operation. The main monitorable characteristics are dark current, efficiency for muon detection, noise rate etc. Herein we describe an automated tool for CMS RPC current monitoring which uses Machine Learning techniques. We further elaborate on the dedicated generalized linear model proposed already and add autoencoder models for self-consistent predictions as well as hybrid models to allow for RPC current predictions in a distant future.
PDF
