Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

Social Media and Depressive Symptoms in Childhood and Adolescence: A Systematic Review

Concerns are increasingly raised in academic and lay literature about the impact of the internet on young people’s well-being. This systematic review examined empirical research on the relationship between social media use and depressive symptoms in the child and adolescent population. A systematic search of Medline, PsycInfo and Embase databases yielded eleven eligible studies. Relevant results were extracted from each study, with a total sample of 12,646. Analysis revealed a small but statistically significant correlation between social media use and depressive symptoms in young people. However, studies varied widely in methods, sample size and results, making the clinical significance of these findings nuanced. Over half of the studies were cross-sectional, while those of longitudinal design were of limited duration. This review justifies further investigation of this phenomenon, with a need for consensus on variables and measurement

Performance and Operation of the CMS Electromagnetic Calorimeter

The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented

A critical analysis of the stall onset in vertical axis wind turbines

The dynamic stall phenomenon in Vertical Axis Wind Turbines (VAWTs) appears under some operating conditions that have not been very well established. Some studies have focused on describing the topology of the dynamic stall but little attention has been paid to understand how all the operating VAWT parameters influence the moment of stall inception. This paper focuses on analysing the influence of the tip speed ratio, pitch angle, reduced frequency, relative velocity and Reynolds number on the stall-onset angle of VAWTs. CFD simulations with an oscillating NACA0015 describing the angle of attack and relative velocity in VAWTs were employed. The results have revealed that an increase in the stall-onset occurs anytime the operating parameters increase the value of the non-dimensional pitch rate and the Reynolds number at the moment the angle of attack approaches to the static stall angle. The stall-onset angle showed a linear increase with the non-dimensional pitch rate in the range of Reynolds number tested, namely 0.8–3.3 x 10^5. This paper has elucidated how the several parameters governing VAWTs operation affect the stall-onset angle and therefore has contributed to a much better understanding of the causes that induce the stall in these devices

Performance studies of the CMS strip tracker before installation

Peer reviewe

CMS Data Processing Workflows during an Extended Cosmic Ray Run

Peer reviewe

Aligning the CMS Muon Chambers with the Muon Alignment System during an Extended Cosmic Ray Run

Peer reviewe

Calibration of the CMS Drift Tube Chambers and Measurement of the Drift Velocity with Cosmic Rays

Peer reviewe

CMS physics technical design report : Addendum on high density QCD with heavy ions

Peer reviewe

Commissioning of the CMS high-level trigger with cosmic rays

This is the Pre-print version of the Article. The official published version of the paper can be accessed from the link below - Copyright @ 2010 IOPThe CMS High-Level Trigger (HLT) is responsible for ensuring that data samples with potentially interesting events are recorded with high efficiency and good quality. This paper gives an overview of the HLT and focuses on its commissioning using cosmic rays. The selection of triggers that were deployed is presented and the online grouping of triggered events into streams and primary datasets is discussed. Tools for online and offline data quality monitoring for the HLT are described, and the operational performance of the muon HLT algorithms is reviewed. The average time taken for the HLT selection and its dependence on detector and operating conditions are presented. The HLT performed reliably and helped provide a large dataset. This dataset has proven to be invaluable for understanding the performance of the trigger and the CMS experiment as a whole.This work is supported by FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia); Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTDS (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA)