150 research outputs found

    Transport properties of dense fluid argon

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    We calculate using molecular dynamics simulations the transport properties of realistically modeled fluid argon at pressures up to 50GPa\simeq 50GPa and temperatures up to 3000K3000K. In this context we provide a critique of some newer theoretical predictions for the diffusion coefficients of liquids and a discussion of the Enskog theory relevance under two different adaptations: modified Enskog theory (MET) and effective diameter Enskog theory. We also analyze a number of experimental data for the thermal conductivity of monoatomic and small diatomic dense fluids.Comment: 8 pages, 6 figure

    Returning to Text: Affect, meaning making and literacies

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    Existing work on literacy and affect has posed important questions for how we think about meanings and how and where they get made. The authors contribute to such work by focusing on the relation between text and affect. This is a topic that has received insufficient attention in recent work but is of pressing concern for education as text interweaves in new ways with human activity, through social media, surveillance capitalism, and artificial intelligence—ways that can be unpredictable and poorly understood. Adopting a sociomaterial sensibility that foregrounds the relations between bodies (people and things), the authors provide conceptual tools for considering how texts affect and are affected by the heterogeneous entanglements from which they emerge. In situating their argument, the authors outline influential readings of Spinoza’s theories of affect, explore how these have been mobilized in literacy research, and identify how text has been accommodated within such research. Using texts from a political episode in the United Kingdom, the authors explore the idea of social-material-textual affects to articulate relationships among humans, nonhumans, meaning making, and literacies. The authors conclude by identifying four ways in which text participates in what happens, raising questions about how different materializations of text (or indeed “not text”) are significant to the diversifying communicative practices that inflect social, cultural, economic, and political life

    Early extracorporeal CPR for refractory out-of-hospital cardiac arrest

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    BACKGROUNDExtracorporeal cardiopulmonary resuscitation (CPR) restores perfusion and oxy-genation in a patient who does not have spontaneous circulation. The evidencewith regard to the effect of extracorporeal CPR on survival with a favorable neu-rologic outcome in refractory out-of-hospital cardiac arrest is inconclusive.METHODSIn this multicenter, randomized, controlled trial conducted in the Netherlands, weassigned patients with an out-of-hospital cardiac arrest to receive extracorporealCPR or conventional CPR (standard advanced cardiac life support). Eligible patientswere between 18 and 70 years of age, had received bystander CPR, had an initialventricular arrhythmia, and did not have a return of spontaneous circulationwithin 15 minutes after CPR had been initiated. The primary outcome was sur-vival with a favorable neurologic outcome, defined as a Cerebral PerformanceCategory score of 1 or 2 (range, 1 to 5, with higher scores indicating more severedisability) at 30 days. Analyses were performed on an intention-to-treat basis.RESULTSOf the 160 patients who underwent randomization, 70 were assigned to receiveextracorporeal CPR and 64 to receive conventional CPR; 26 patients who did notmeet the inclusion criteria at hospital admission were excluded. At 30 days, 14 pa-tients (20%) in the extracorporeal-CPR group were alive with a favorable neuro-logic outcome, as compared with 10 patients (16%) in the conventional-CPR group(odds ratio, 1.4; 95% confidence interval, 0.5 to 3.5; P = 0.52). The number of seri-ous adverse events per patient was similar in the two groups.CONCLUSIONSIn patients with refractory out-of-hospital cardiac arrest, extracorporeal CPR andconventional CPR had similar effects on survival with a favorable neurologic out-come. (Funded by the Netherlands Organization for Health Research and Develop-ment and Maquet Cardiopulmonary [Getinge]; INCEPTION ClinicalTrials.govnumber, NCT03101787.)Cardiolog

    Measurement of the azimuthal anisotropy of Y(1S) and Y(2S) mesons in PbPb collisions at √S^{S}NN = 5.02 TeV

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    The second-order Fourier coefficients (υ2_{2}) characterizing the azimuthal distributions of Υ(1S) and Υ(2S) mesons produced in PbPb collisions at sNN\sqrt{s_{NN}} = 5.02 TeV are studied. The Υmesons are reconstructed in their dimuon decay channel, as measured by the CMS detector. The collected data set corresponds to an integrated luminosity of 1.7 nb1^{-1}. The scalar product method is used to extract the υ2_{2} coefficients of the azimuthal distributions. Results are reported for the rapidity range |y| < 2.4, in the transverse momentum interval 0 < pT_{T} < 50 GeV/c, and in three centrality ranges of 10–30%, 30–50% and 50–90%. In contrast to the J/ψ mesons, the measured υ2_{2} values for the Υ mesons are found to be consistent with zero

    Measurement of prompt D0^{0} and D\overline{D}0^{0} meson azimuthal anisotropy and search for strong electric fields in PbPb collisions at root SNN\sqrt{S_{NN}} = 5.02 TeV

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    The strong Coulomb field created in ultrarelativistic heavy ion collisions is expected to produce a rapiditydependent difference (Av2) in the second Fourier coefficient of the azimuthal distribution (elliptic flow, v2) between D0 (uc) and D0 (uc) mesons. Motivated by the search for evidence of this field, the CMS detector at the LHC is used to perform the first measurement of Av2. The rapidity-averaged value is found to be (Av2) = 0.001 ? 0.001 (stat)? 0.003 (syst) in PbPb collisions at ?sNN = 5.02 TeV. In addition, the influence of the collision geometry is explored by measuring the D0 and D0mesons v2 and triangular flow coefficient (v3) as functions of rapidity, transverse momentum (pT), and event centrality (a measure of the overlap of the two Pb nuclei). A clear centrality dependence of prompt D0 meson v2 values is observed, while the v3 is largely independent of centrality. These trends are consistent with expectations of flow driven by the initial-state geometry. ? 2021 The Author. Published by Elsevier B.V. This is an open access article under the CC BY licens

    Performance of reconstruction and identification of τ leptons decaying to hadrons and vτ in pp collisions at √s=13 TeV

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    The algorithm developed by the CMS Collaboration to reconstruct and identify τ leptons produced in proton-proton collisions at √s=7 and 8 TeV, via their decays to hadrons and a neutrino, has been significantly improved. The changes include a revised reconstruction of π⁰ candidates, and improvements in multivariate discriminants to separate τ leptons from jets and electrons. The algorithm is extended to reconstruct τ leptons in highly Lorentz-boosted pair production, and in the high-level trigger. The performance of the algorithm is studied using proton-proton collisions recorded during 2016 at √s=13 TeV, corresponding to an integrated luminosity of 35.9 fb¯¹. The performance is evaluated in terms of the efficiency for a genuine τ lepton to pass the identification criteria and of the probabilities for jets, electrons, and muons to be misidentified as τ leptons. The results are found to be very close to those expected from Monte Carlo simulation

    Performance of the CMS Level-1 trigger in proton-proton collisions at √s = 13 TeV

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    At the start of Run 2 in 2015, the LHC delivered proton-proton collisions at a center-of-mass energy of 13\TeV. During Run 2 (years 2015–2018) the LHC eventually reached a luminosity of 2.1× 1034^{34} cm2^{-2}s1^{-1}, almost three times that reached during Run 1 (2009–2013) and a factor of two larger than the LHC design value, leading to events with up to a mean of about 50 simultaneous inelastic proton-proton collisions per bunch crossing (pileup). The CMS Level-1 trigger was upgraded prior to 2016 to improve the selection of physics events in the challenging conditions posed by the second run of the LHC. This paper describes the performance of the CMS Level-1 trigger upgrade during the data taking period of 2016–2018. The upgraded trigger implements pattern recognition and boosted decision tree regression techniques for muon reconstruction, includes pileup subtraction for jets and energy sums, and incorporates pileup-dependent isolation requirements for electrons and tau leptons. In addition, the new trigger calculates high-level quantities such as the invariant mass of pairs of reconstructed particles. The upgrade reduces the trigger rate from background processes and improves the trigger efficiency for a wide variety of physics signals

    Studies of charm and beauty hadron long-range correlations in pp and pPb collisions at LHC energies

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    An embedding technique to determine ττ backgrounds in proton-proton collision data

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