1,964 research outputs found

    A Variational Method in Out of Equilibrium Physical Systems

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    A variational principle is further developed for out of equilibrium dynamical systems by using the concept of maximum entropy. With this new formulation it is obtained a set of two first-order differential equations, revealing the same formal symplectic structure shared by classical mechanics, fluid mechanics and thermodynamics. In particular, it is obtained an extended equation of motion for a rotating dynamical system, from where it emerges a kind of topological torsion current of the form Ï”ijkAjωk\epsilon_{ijk} A_j \omega_k, with AjA_j and ωk\omega_k denoting components of the vector potential (gravitational or/and electromagnetic) and ω\omega is the angular velocity of the accelerated frame. In addition, it is derived a special form of Umov-Poynting's theorem for rotating gravito-electromagnetic systems, and obtained a general condition of equilibrium for a rotating plasma. The variational method is then applied to clarify the working mechanism of some particular devices, such as the Bennett pinch and vacuum arcs, to calculate the power extraction from an hurricane, and to discuss the effect of transport angular momentum on the radiactive heating of planetary atmospheres. This development is seen to be advantageous and opens options for systematic improvements.Comment: 22 pages, 1 figure, submitted to review, added one referenc

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+→Ό+ÎœW^+ \rightarrow \mu^+\nu and W−→Ό−ΜW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Search for direct stau production in events with two hadronic tau-leptons in root s=13 TeV pp collisions with the ATLAS detector

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    A search for the direct production of the supersymmetric partners ofτ-leptons (staus) in final stateswith two hadronically decayingτ-leptons is presented. The analysis uses a dataset of pp collisions corresponding to an integrated luminosity of139fb−1, recorded with the ATLAS detector at the LargeHadron Collider at a center-of-mass energy of 13 TeV. No significant deviation from the expected StandardModel background is observed. Limits are derived in scenarios of direct production of stau pairs with eachstau decaying into the stable lightest neutralino and oneτ-lepton in simplified models where the two staumass eigenstates are degenerate. Stau masses from 120 GeV to 390 GeV are excluded at 95% confidencelevel for a massless lightest neutralino

    POREZ NA DOHODAK U REPUBLICI HRVATSKOJ

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    Ovaj članak obrađuje porez na dohodak kao neposredni (izravni) porez u poreznom sustavu Republike Hrvatske kojim su obuhvaćeni fizičke osobe, obveznici poreza na dohodak. Definiranje i pojaơnjenje vrste dohodaka s obzirom na izvor dohotka i to: dohodak od nesamostalnog rada, dohodak od samostalne djelatnosti, dohodak od imovine i imovinskih prava, dohodak od kapitala, dohodak od osiguranja, drugi dohodak, te metodologija utvrđivanja porezne obveze i poreznih stopa i utvrđivanje poreznog razdoblja. Navedeni su primici koji se ne smatraju dohotkom, ơto je to porezni gubitak te osobni odbitak kao neoporezivi dio dohotka

    Gene Expression Profiling of Two Distinct Neuronal Populations in the Rodent Spinal Cord

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    BACKGROUND: In the field of neuroscience microarray gene expression profiles on anatomically defined brain structures are being used increasingly to study both normal brain functions as well as pathological states. Fluorescent tracing techniques in brain tissue that identifies distinct neuronal populations can in combination with global gene expression profiling potentially increase the resolution and specificity of such studies to shed new light on neuronal functions at the cellular level. METHODOLOGY/PRINCIPAL FINDINGS: We examine the microarray gene expression profiles of two distinct neuronal populations in the spinal cord of the neonatal rat, the principal motor neurons and specific interneurons involved in motor control. The gene expression profiles of the respective cell populations were obtained from amplified mRNA originating from 50-250 fluorescently identified and laser microdissected cells. In the data analysis we combine a new microarray normalization procedure with a conglomerate measure of significant differential gene expression. Using our methodology we find 32 genes to be more expressed in the interneurons compared to the motor neurons that all except one have not previously been associated with this neuronal population. As a validation of our method we find 17 genes to be more expressed in the motor neurons than in the interneurons and of these only one had not previously been described in this population. CONCLUSIONS/SIGNIFICANCE: We provide an optimized experimental protocol that allows isolation of gene transcripts from fluorescent retrogradely labeled cell populations in fresh tissue, which can be used to generate amplified aRNA for microarray hybridization from as few as 50 laser microdissected cells. Using this optimized experimental protocol in combination with our microarray analysis methodology we find 49 differentially expressed genes between the motor neurons and the interneurons that reflect the functional differences between these two cell populations in generating and transmitting the motor output in the rodent spinal cord

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Testbeam results of irradiated ams H18 HV-CMOS pixel sensor prototypes

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    HV-CMOS pixel sensors are a promising option for the tracker upgrade of the ATLAS experiment at the LHC, as well as for other future tracking applications in which large areas are to be instrumented with radiation-tolerant silicon pixel sensors. We present results of testbeam characterisations of the 4th generation of Capacitively Coupled Pixel Detectors (CCPDv4) produced with the ams H18 HV-CMOS process that have been irradiated with different particles (reactor neutrons and 18 MeV protons) to fluences between 1× 1014 and 5× 1015 1−MeV− neq. The sensors were glued to ATLAS FE-I4 pixel readout chips and measured at the CERN SPS H8 beamline using the FE-I4 beam telescope. Results for all fluences are very encouraging with all hit efficiencies being better than 97% for bias voltages of 85 V. The sample irradiated to a fluence of 1× 1015 neq—a relevant value for a large volume of the upgraded tracker—exhibited 99.7% average hit efficiency. The results give strong evidence for the radiation tolerance of HV-CMOS sensors and their suitability as sensors for the experimental HL-LHC upgrades and future large-area silicon-based tracking detectors in high-radiation environments

    MuPix and ATLASPix -- Architectures and Results

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    High Voltage Monolithic Active Pixel Sensors (HV-MAPS) are based on a commercial High Voltage CMOS process and collect charge by drift inside a reversely biased diode. HV-MAPS represent a promising technology for future pixel tracking detectors. Two recent developments are presented. The MuPix has a continuous readout and is being developed for the Mu3e experiment whereas the ATLASPix is being developed for LHC applications with a triggered readout. Both variants have a fully monolithic design including state machines, clock circuitries and serial drivers. Several prototypes and design variants were characterised in the lab and in testbeam campaigns to measure efficiencies, noise, time resolution and radiation tolerance. Results from recent MuPix and ATLASPix prototypes are presented and prospects for future improvements are discussed.Comment: 10 pages, proceedings, The 28th International Workshop on Vertex Detectors (VERTEX 2019), 13 - 18 Oct 2019, Lopud Island, Croati
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