3,021 research outputs found

    Status of the ALICE detector and first results

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    The status of the ALICE detector at the CERN LHC is reviewed. First physics results from proton-proton collisions recorded during the 2009 data-taking period are presented

    Saturated phase densities of (CO2 + H2O) at temperatures from (293 to 450) K and pressures up to 64 MPa

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    An apparatus consisting of an equilibrium cell connected to two vibrating tube densimeters and two syringe pumps was used to measure the saturated phase densities of (CO2 + H2O) at temperatures from (293 to 450) K and pressures up to 64 MPa, with estimated average standard uncertainties of 1.5 kg · m−3 for the CO2-rich phase and 1.0 kg · m−3 for the aqueous phase. The densimeters were housed in the same thermostat as the equilibrium cell and were calibrated in situ using pure water, CO2 and helium. Following mixing, samples of each saturated phase were displaced sequentially at constant pressure from the equilibrium cell into the vibrating tube densimeters connected to the top (CO2-rich phase) and bottom (aqueous phase) of the cell. The aqueous phase densities are predicted to within 3 kg · m−3 using empirical models for the phase compositions and partial molar volumes of each component. However, a recently developed multi-parameter equation of state (EOS) for this binary mixture, Gernert and Span [32], was found to under predict the measured aqueous phase density by up to 13 kg · m−3. The density of the CO2-rich phase was always within about 8 kg · m−3 of the density for pure CO2 at the same pressure and temperature; the differences were most positive near the critical density, and became negative at temperatures above about 373 K and pressures below about 10 MPa. For this phase, the multi-parameter EOS of Gernert and Span describes the measured densities to within 5 kg · m−3, whereas the computationally-efficient cubic EOS model of Spycher and Pruess (2010), commonly used in simulations of subsurface CO2 sequestration, deviates from the experimental data by a maximum of about 8 kg · m−3

    CPO and quantitative textural analyses within sheath folds

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    Acknowledgments This has been a multi-national collaboration from authors based in Europe, North America, Australia and India. Erasmus funding to GIA in 2018 enabled a visit to Catania leading to discussion and initiation of this project. The authors are grateful to Amarnath Dandapat for preparation of superpolished rock thin sections at the Department of Geology and Geophysics (IIT Kharagpur, India). Niloy Bhowmik is thanked for assistance with SEM-EBSD data generation in the Central Research Facility (IIT Kharagpur, India). E.F. thanks Sibio Carmelo for thin sections preparation at the University of Turin (Italy). Authors are grateful to ANSTO laboratory personnel for the preparation of specimens (funded proposals: P9835 with the title “Sheath fold texture characterisation”, principal scientist: E.F.; co-proposers: G.I.A. and V.L.; DB6749 with the title “Texture analysis of rocks”, principal scientist: V.L.; co-proposer: E.F.; DB9606 with the title “A pilot experiment for texture characterisation in a sheath fold”, principal scientist: E.F..; co-proposers: G.I.A. and V.L.). L.N. and R.G. report that this publication has been assigned the NRCan contribution number 20230109. Many thanks to Richard D. Law and an anonymous reviewer for their careful revision that substantially improved the original version of the manuscript. We also thanks Dr. T.K. Cawood from the Geological Survey of Canada for her useful comments on the drafted manuscript. The editorial handling by Fabrizio Agosta is greatly appreciated.Peer reviewedPublisher PD

    Structural setting of a transpressive shear zone: Insights from geological mapping, quartz petrofabric and kinematic vorticity analysis in NE Sardinia (Italy)

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    The Posada-Asinara Line is a crustal-scale transpressive shear zone affecting the Variscan basement in northern Sardinia during Late Carboniferous time. We investigated a structural transect of the Posada-Asinara Line (Baronie) with the aid of geological mapping and structural analysis. N-verging F2 isoclinal folds with associated mylonitic foliation (S2) are the main deformation features developed during the Posada-Asinara Line activity (D2). The mineral assemblages and microstructures suggest that the Posada-Asinara Line was affected by a retrograde metamorphic path. This is also confirmed by quartz microstructures, where subgrain rotation recrystallization superimposes on grain boundary migration recrystallization. Crystallographic preferred orientation data, obtained using electron backscatter diffraction, allowed analysis of quartz slip systems and estimation of the deformation temperature, vorticity of flow and rheological parameters (flow stress and strain rate) during the Posada-Asinara Line activity. Quartz deformation temperatures of 400 ± 50 °C have been estimated along a transect perpendicular to the Posada-Asinara Line, in agreement with the syn-kinematic post-metamorphic peak mineral assemblages and the late microstructures of quartz. The D2 phase can be subdivided in two events: an early D2early phase, related to the metamorphic peak and low kinematic vorticity (pure shear dominated), and a late D2late phase characterized by a lower metamorphic grade and an increased kinematic vorticity (simple shear dominated). Palaeopiezometry and strain rate estimates associated with the D2late deformation event showed an intensity gradient increasing towards the core of the shear zone. The D2early deformation developed under peak temperature conditions, while the D2late event was active at shallower structural levels

    A new Low Gain Avalanche Diode concept: the double-LGAD

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    This paper describes the new concept of the double-LGAD. The goal is to increase the charge at the input of the electronics, keeping a time resolution equal or better than a standard (single) LGAD; this has been realized by adding the charges of two coupled LGADs while still using a single front-end electronics. The study here reported has been done starting from single LGAD with a thickness of 25 \textmu{m}, 35 \textmu{m} and 50 \textmu{m}.Comment: arXiv admin note: text overlap with arXiv:2208.0571

    Multiple Sclerosis in the Mount Etna Region: Possible Role of Volcanogenic Trace Elements

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    Background: Trace elements have been hypothesised to be involved in the pathogenesis of Multiple Sclerosis and volcanic degassing is the major natural sources of trace elements. Both incidence of Multiple Sclerosis in Catania and volcanic activity of Mount Etna have been significantly increased during the last 30 years. Due to prevailing trade winds direction, volcanic gases from Etna summit craters are mostly blown towards the eastern and southern sectors of the volcano. Objective: To evaluate the possible association between Multiple Sclerosis and exposure to volcanogenic trace elements. Methods: We evaluated prevalence and incidence of Multiple Sclerosis in four communities (47,234 inhabitants) located in the eastern flank and in two communities (52,210 inhabitants) located in the western flank of Mount Etna, respectively the most and least exposed area to crater gas emissions. Results: A higher prevalence was found in the population of the eastern flank compared to the population of the western one (137.6/100,000 versus 94.3/100,000; p-value 0.04). We found a borderline significantly higher incidence risk during the incidence study period (1980–2009) in the population of the eastern flank 4.6/100,000 (95% CI 3.1–5.9), compared with the western population 3.2/100,000 (95% CI 2.4–4.2) with a RR of 1.41 (95% CI 0.97–2.05; p-value 0.06). Incidence risks have increased over the time in both populations reaching a peak of 6.4/100,000 in the eastern flank and of 4.4/100.000 in the western flank during 2000–2009. Conclusion: We found a higher prevalence and incidence of Multiple Sclerosis among populations living in the eastern flank of Mount Etna. According to our data a possible role of TE cannot be ruled out as possible co-factor in the MS pathogenesis. However larger epidemiological study are needed to confirm this hypothesis.Publishede742596A. Monitoraggio ambientale, sicurezza e territorioJCR Journalope

    A simulation tool for MRPC telescopes of the EEE project

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    The Extreme Energy Events (EEE) Project is mainly devoted to the study of the secondary cosmic ray radiation by using muon tracker telescopes made of three Multigap Resistive Plate Chambers (MRPC) each. The experiment consists of a telescope network mainly distributed across Italy, hosted in different building structures pertaining to high schools, universities and research centers. Therefore, the possibility to take into account the effects of these structures on collected data is important for the large physics programme of the project. A simulation tool, based on GEANT4 and using GEMC framework, has been implemented to take into account the muon interaction with EEE telescopes and to estimate the effects on data of the structures surrounding the experimental apparata.A dedicated event generator producing realistic muon distributions, detailed geometry and microscopic behavior of MRPCs have been included to produce experimental-like data. The comparison between simulated and experimental data, and the estimation of detector resolutions is here presented and discussed

    Study of single muons with the Large Volume Detector at Gran Sasso Laboratory

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    The present study is based on the sample of about 3 mln single muons observed by LVD at underground Gran Sasso Laboratory during 36500 live hours from June 1992 to February 1998. We have measured the muon intensity at slant depths from 3 km w.e. to 20 km w.e. Most events are high energy downward muons produced by meson decay in the atmosphere. The analysis of these muons has revealed the power index of pion and kaon spectrum: 2.76 \pm 0.05. The reminders are horizontal muons produced by the neutrino interactions in the rock surrounding LVD. The value of this flux is obtained. The results are compared with Monte Carlo simulations and the world data.Comment: 13 pages, 2 figures, accepted for publication in "Physics of Atomic Nuclei

    The Extreme Energy Events HECR array: status and perspectives

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    The Extreme Energy Events Project is a synchronous sparse array of 52 tracking detectors for studying High Energy Cosmic Rays (HECR) and Cosmic Rays-related phenomena. The observatory is also meant to address Long Distance Correlation (LDC) phenomena: the network is deployed over a broad area covering 10 degrees in latitude and 11 in longitude. An overview of a set of preliminary results is given, extending from the study of local muon flux dependance on solar activity to the investigation of the upward-going component of muon flux traversing the EEE stations; from the search for anisotropies at the sub-TeV scale to the hints for observations of km-scale Extensive Air Shower (EAS).Comment: XXV ECRS 2016 Proceedings - eConf C16-09-04.
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