882 research outputs found
Fiber Bragg Grating sensors for deformation monitoring of GEM foils in HEP detectors
Fiber Bragg Grating (FBG) sensors have been so far mainly used in high energy
physics (HEP) as high precision positioning and re-positioning sensors and as
low cost, easy to mount, radiation hard and low space- consuming temperature
and humidity devices. FBGs are also commonly used for very precise strain
measurements. In this work we present a novel use of FBGs as flatness and
mechanical tensioning sensors applied to the wide Gas Electron Multiplier (GEM)
foils of the GE1/1 chambers of the Compact Muon Solenoid (CMS) experiment at
Large Hadron Collider (LHC) of CERN. A network of FBG sensors has been used to
determine the optimal mechanical tension applied and to characterize the
mechanical stress applied to the foils. The preliminary results of the test
performed on a full size GE1/1 final prototype and possible future developments
will be discussed.Comment: Four pages, seven figures. Presented by Michele Caponero at IWASI
2015, Gallipoli (Italy
Light sterile neutrino production in the early universe with dynamical neutrino asymmetries
Light sterile neutrinos mixing with the active ones have been recently
proposed to solve different anomalies observed in short-baseline oscillation
experiments. These neutrinos can also be produced by oscillations of the active
neutrinos in the early universe, leaving possible traces on different
cosmological observables. Here we perform an updated study of the neutrino
kinetic equations in (3+1) and (2+1) oscillation schemes, dynamically evolving
primordial asymmetries of active neutrinos and taking into account for the
first time CP-violation effects. In the absence of neutrino asymmetries,
eV-mass scale sterile neutrinos would be completely thermalized creating a
tension with respect to the CMB, LSS and BBN data. In the past literature,
active neutrino asymmetries have been invoked as a way to inhibit the sterile
neutrino production via the in-medium suppression of the sterile-active mixing
angle. However, neutrino asymmetries also permit a resonant sterile neutrino
production. We find that if the active species have equal asymmetries L, a
value |L|=10^{-3} is required to start suppressing the resonant sterile
production, roughly an order of magnitude larger than what previously expected.
When active species have opposite asymmetries the sterile abundance is further
enhanced, requiring an even larger |L|\simeq 10^{-2} to start suppressing their
production. In the latter case, CP-violation (naturally expected) further
exacerbates the phenomenon. Some consequences for cosmological observables are
briefly discussed: for example, it is likely that moderate suppressions of the
sterile species production are associated with significant spectral distortions
of the active neutrino species, with potentially interesting phenomenological
consequences especially for BBN.Comment: (v2: 22 pages, 10 eps figures. Revised version. Typos removed,
reference updated. Matches the version published on PRD.
Eco-friendly gas mixtures for Resistive Plate Chambers based on Tetrafluoropropene and Helium
Due to the recent restrictions deriving from the application of the Kyoto
protocol, the main components of the gas mixtures presently used in the
Resistive Plate Chambers systems of the LHC experiments will be most probably
phased out of production in the coming years. Identifying possible replacements
with the adequate characteristics requires an intense R&D, which was recently
started, also in collaborations across the various experiments. Possible
candidates have been proposed and are thoroughly investigated. Some tests on
one of the most promising candidate - HFO-1234ze, an allotropic form of
tetrafluoropropane- have already been reported. Here an innovative approach,
based on the use of Helium, to solve the problems related to the too elevate
operating voltage of HFO-1234ze based gas mixtures, is discussed and the
relative first results are shown.Comment: 9 pages, 6 figures, 1 tabl
Galectin-9 Regulates Monosodium Urate Crystal-Induced Gouty Inflammation Through the Modulation of Treg/Th17 Ratio
Gout is caused by depositing monosodium urate (MSU) crystals within the articular area. The infiltration of neutrophils and monocytes drives the initial inflammatory response followed by lymphocytes. Interestingly, emerging evidence supports the view that in situ imbalance of T helper 17 cells (Th17)/regulatory T cells (Treg) impacts the subsequent damage to target tissues. Galectin-9 (Gal-9) is a modulator of innate and adaptive immunity with both pro- and anti-inflammatory functions, dependent upon its expression and cellular location. However, the specific cellular and molecular mechanisms by which Gal-9 modulates the inflammatory response in the onset and progression of gouty arthritis has yet to be elucidated. In this study, we sought to comprehensively characterise the functional role of exogenous Gal-9 in an in vivo model of MSU crystal-induced gouty inflammation by monitoring in situ neutrophils, monocytes and Th17/Treg recruited phenotypes and related cyto-chemokines profile. Treatment with Gal-9 revealed a dose-dependent reduction in joint inflammation scores, knee joint oedema and expression of different pro-inflammatory cyto-chemokines. Furthermore, flow cytometry analysis highlighted a significant modulation of infiltrating inflammatory monocytes (CD11b+/CD115+/LY6-Chi) and Th17 (CD4+/IL-17+)/Treg (CD4+/CD25+/FOXP-3+) cells following Gal-9 treatment. Collectively the results presented in this study indicate that the administration of Gal-9 could provide a new therapeutic strategy for preventing tissue damage in gouty arthritic inflammation and, possibly, in other inflammatory-based diseases
Cms gem detector material study for the hl-lhc
A study on the Gaseous Electron Multiplier (GEM) foil material is performed to determine the moisture diffusion rate, moisture saturation level and the effects on its mechanical properties. The study is focused on the foil contact with ambient air and moisture to determine the value of the diffusion coefficient of water in the foil material. The presence of water inside the detector foil can determine the changes in its mechanical and electrical properties. A simulated model is developed with COMSOL Multiphysics v. 4.3 [1] by taking into account the real GEM foil (hole dimensions, shapes and material), which describes the adsorption of water. This work describes the model, its experimental verification, the water diffusion within the entire sheet geometry of the GEM foil, thus gaining concentration profiles and the time required to saturate the system and the effects on the mechanical properties
Emotional rational education training associated with mindfulness for managing anxiety within adolescents affected by high-functioning autism: A descriptive study
Background: Autism spectrum disorder (ASD) is a chronic and persistent pervasive developmental disorder (PDD) whose characteristic deficit is represented by social difficulties, semantic–pragmatic alterations and a limited, unusual and repetitive pattern of interests and be-haviors. Specifically, individuals with high-functioning autism (HFA) frequently exhibit associated internalizing symptoms that are not part of the diagnostic criteria but which, nonetheless, tend to impair daily functioning. In this study, we investigated how some forms of treatment could be useful in subjects with HFA who display internalizing symptoms. Theoretical background relates to standard cognitive therapy (SCT) and rational education training with mindfulness (M-ERE). Methods: In this study, we investigated how some forms of treatment could be useful in subjects with HFA and internalizing symptoms, focusing on standard cognitive therapy (SCT) and mindfulness associated with emotional rational education training (M-ERE). We selected two groups of HFA patients with significant internalizing symptoms and performed two different forms of treatment for six months: SCT and M-ERE. The aim of the study was to verify the effectiveness of an M-ERE protocol with respect to anxious and depressive symptoms in subjects with HFA. Furthermore, we wanted to compare the results obtained with this combined treatment with those obtained in HFA subjects treated with SCT. Results: Our analyses showed an improvement in the internalizing symptoms (especially those related to the anxiety dimension) of the group that followed a treatment based on mindfulness and rational emotional education for 6 months compared to the group that had instead performed a 6-month treatment based on the SCT. Conclusions: Our hypotheses were supported by the results, which highlighted the efficacy of mindfulness-based interventions in the treatment of internalizing symptoms in adolescents with HFA, and specifically showed that an M-ERE intervention appears more effective in managing anxiety compared to treatment with SCT and appears to be equally effective in the management of depressive symptoms. Not only was the M-ERE treatment effective for the management of anxious and depressive symptoms in subjects with HFA, but the efficacy for the management of anxious symptoms was greater than the SCT treatment
Properties of potential eco-friendly gas replacements for particle detectors in high-energy physics
Gas detectors for elementary particles require F-based gases for optimal performance.
Recent regulations demand the use of environmentally unfriendly F-based gases to be limited or
banned. This work studies properties of potential eco-friendly gas replacements by computing the
physical and chemical parameters relevant for use as detector media, and suggests candidates to be
considered for experimental investigation
Properties of potential eco-friendly gas replacements for particle detectors in high-energy physics
Modern gas detectors for detection of particles require F-based gases for
optimal performance. Recent regulations demand the use of environmentally
unfriendly F-based gases to be limited or banned. This review studies
properties of potential eco-friendly gas candidate replacements.Comment: 38 pages, 9 figures, 8 tables. To be submitted to Journal of
Instrumentatio
Octocrylene: From Sunscreens to the Degradation Pathway during Chlorination Processes: Formation of Byproducts and Their Ecotoxicity Assessment
Octocrylene is an organic sunscreen whose main action is to absorb UVB radiation and short UVA wavelengths; it is used in various cosmetic products in order to provide an adequate sun-protection factor or to protect the cosmetic formulations themselves from UV radiation. This filter is believed to be a possible endocrine disruptor and is also questioned due to its allergic and/or photoallergic potential. However, it continues to be widely used, and it has been found in various environments, not least those of swimming pools, where it is evidently released by consumers, to the point that it is now considered an emerging micropollutant. The present investigation presents the possible chemical fate of octocrylene in the typical chlorination conditions of wastewater or swimming pools. A total of 11 disinfection byproducts were identified, and 6 were identified for the first time, and separated by HPLC. These products were identified through careful mass spectrometry studies and 1D and 2D NMR experiments. A formation mechanism has been proposed that justifies the chemical structures of all of the compounds identified. The ecotoxicological assessment of octocrylene and their products was carried out by employing Phaeodactylum tricornutum, Brachionus plicatilis and Aliivibrio fischeri as bioindicators. The ecotoxicity results reveal that toxic byproducts might be generated during the oxidation process, increasing the potential risk to the marine environment
Candidate eco-friendly gas mixtures for MPGDs
Modern gas detectors for detection of particles require F-based gases for optimal performance.Recent regulations demand the use of environmentally unfriendly F-based gases t o be limited or banned. This review studies properties of potential eco-friendly gas candidate replacements
- …