676 research outputs found
Characterization of the flow-field in circular subsonic impinging jets: Investigation of surface pressure fluctuations and far-field noise emissions through pressure sensor measurements
No full textImpinging jets are relevant ow configurations in many technological developments. For example, on some short take-off and landing aircraft the high speed exhaust from the jet engine is deflected by direct impingement on the aps to create extra lift during take-off. Fatigue due to excessive dynamic loading on the aps and high levels of noise radiation are among the problems encountered in such designs. Additionally, such flow-structure interaction is a good model for cooling of turbine blades, annealing of plastic and metal sheets, deicing of aircraft systems etc.. Jets are easy to simulate and contain all the constituents necessary for the study of shear flows. The shear-layer instability at the nozzle edge develops into axisymmetric toroidal vortices which magnifies in size and strength downstream of the nozzle. The interaction of these vortices with the solid structures induces pressure fluctuations that manifests in the form of noise in the far-field region. Hence, it is also a benchmark case for studying vortex-structure interaction noise.Aerospace Engineering | Aerodynamics and Wind Energ
The dichotomy of love and death in the fictional work of Teolinda Gersão
No full textIn this present analysis into the work of the contemporary Portuguese author Teolinda Gersão the metaphorical use of Death in her novels emerges as fulfilling a dual function; firstly as political, societal and linguistic non-representation, on the one hand, and, secondly, as a means of transgressing conventions of time, space and linguistic signification on the other. Death in her novels O Silêncio, Paisagem com Mulher e Mar ao Fundo, O Cavalo de Sol, and A Árvore das Palavras is constituted by a patriarchal and bourgeois hegemony, that allows only spaces of political, societal and linguistic non-existence for the women protagonists. Whereas in A Casa da Cabeça de Cavalo the very foundations of rationality grounded in the values of bourgeois society are transgressed, as parameters of space and time become fluid. In the transitional spaces of love, which are concrete geographical locations, but also modes of resistance within the female psyche, her female protagonists Lídia, Hortense, Vitória, Maria Badala, and Gita find a way of subverting existing cultural and societal norms in order to establish a female self that would not submit to the objectifying mimicry inherent in the patriarchal bourgeois conception of femininity
Resonance Workshop at UT Austin: Hadronic resonance production in heavy ion and elementary collisions
No full textPublisher Correction: Direct observation of the dead-cone effect in quantum chromodynamics (Nature, (2022), 605, 7910, (440-446), 10.1038/s41586-022-04572-w)
No full textIn the version of this article initially published, there was a typographical error in the first sentence following the “Exposing the dead cone” heading, now reading, “The measurements of R(θ), in the three radiator (charmquark) energy intervals 5 < ERadiator < 10 GeV, 10 < ERadiator < 20 GeV and 20 < ERadiator < 35 GeV…,” where “35 GeV” initially appeared as “3 GeV.” The error has been corrected in the HTML and PDF versions of the article. *A list of authors and their affiliations appears online. © The Author(s) 2022
H-3(Lambda) and (3)((Lambda)over-bar)(H)over-bar lifetime measurement in Pb-Pb collisions at root s(NN)=5.02 TeV via two-body decay
No full textAn improved value for the lifetime of the (anti-)hypertriton has been obtained using the data sample of Pb-Pb collisions at root s(NN) = 5.02 TeV collected by the ALICE experiment at the LHC. The (anti-)hypertriton has been reconstructed via its charged two-body mesonic decay channel and the lifetime has been determined from an exponential fit to the dN/d(ct) spectrum. The measured value, tau = 242(-38)(+34) (stat.) +/- 17 (syst.) ps, is compatible with representative theoretical predictions, thus contributing to the solution of the longstanding hypertriton lifetime puzzle. (C) 2019 The Author. Published by Elsevier B.V
Measurement of the production of high-p(T) electrons from heavy-flavour hadron decays in Pb-Pb collisions at root s(NN)=2.76 TeV
No full textElectrons from heavy-flavour hadron decays (charm and beauty) were measured with the ALICE detector in Pb-Pb collisions at a centre-of-mass of energy root s(NN) = 2.76 TeV. The transverse momentum (pT) differential production yields at mid-rapidity were used to calculate the nuclear modification factor R-AA in the interval 3 < p(T) < 18 GeV/c. The R-AA shows a strong suppression compared to binary scaling of pp collisions at the same energy (up to a factor of 4) in the 10% most central Pb-Pb collisions. There is a centrality trend of suppression, and a weaker suppression (down to a factor of 2) in semi-peripheral (50-80%) collisions is observed. The suppression of electrons in this broad p(T) interval indicates that both charm and beauty quarks lose energy when they traverse the hot medium formed in Pb-Pb collisions at LHC. (C) 2017 The Author. Published by Elsevier B.V
Coherent J/ψ photoproduction at forward rapidity in ultra-peripheral Pb–Pb collisions at s NN = 5.02 TeV
No full textThe ALICE collaboration performed the first rapidity-differential measurement of coherent J/psi photoproduction in ultra-peripheral Pb-Pbcollisions at a center-of-mass energy root s(NN) = 5.02TeV. The J/psi is detected via its dimuon decay in the forward rapidity region (-4.0 < y < -2.5) for events where the hadronic activity is required to be minimal. The analysis is based on an event sample corresponding to an integrated luminosity of about 750 mu b(-1). The cross section for coherent J/psi production is presented in six rapidity bins. The results are compared with theoretical models for coherent J/psi photoproduction. These comparisons indicate that gluon shadowing effects play a role in the photoproduction process. The ratio of psi' to J/psi coherent photoproduction cross sections was measured and found to be consistent with that measured for photoproduction off protons. (C) 2019 The Author. Published by Elsevier B.V
Jet-associated deuteron production in pp collisions at root s=13 TeV
No full textDeuteron production in high-energy collisions is sensitive to the space-time evolution of the collision system, and is typically described by a coalescence mechanism. For the first time, we present results on jet-associated deuteron production in pp collisions at root s = 13 TeV, providing an opportunity to test the established picture for deuteron production in events with a hard scattering. Using a trigger particle with high transverse-momentum (p(T) > 5 GeV/c) as a proxy for the presence of a jet at midrapidity, we observe a measurable population of deuterons being produced around the jet proxy. The associated deuteron yield measured in a narrow angular range around the trigger particle differs by 2.4-4.8 standard deviations from the uncorrelated background. The data are described by PYTHIA model calculations featuring baryon coalescence. (C) 2021 The Author. Published by Elsevier B.V
Measuring (KSK +/-)-K-0 interactions using Pb-Pb collisions at root S-NN=2.76 TeV
No full textWe present the first ever measurements of femtoscopic correlations between the K-S(0) and K-+/- particles. The analysis was performed on the data from Pb-Pb collisions at root S-NN = 2.76 TeV measured by the ALICE experiment. The observed femtoscopic correlations are consistent with final-state interactions proceeding via the a(0)(980) resonance. The extracted kaon source radius and correlation strength parameters for (KSK-)-K-0 are found to be equal within the experimental uncertainties to those for (KSK+)-K-0. Comparing the results of the present study with those from published identical-kaon femtoscopic studies by ALICE, mass and coupling parameters for the a(0) resonance are tested. Our results are also compatible with the interpretation of the a(0) having a tetraquark structure instead of that of a diquark. (c) 2017 The Author. Published by Elsevier B.V
First measurement of Xi(0)(c) production in pp collisions at root s=7 TeV
No full textThe production of the charm-strange baryon Xi(0)(c) is measured for the first time at the LHC via its semileptonic decay into e(+) Xi(-) nu(e) in ppcollisions at root s = 7 TeV with the ALICE detector. The transverse momentum ( p(T)) differential cross section multiplied by the branching ratio is presented in the interval 1 < p(T)< 8 GeV/c at mid-rapidity, vertical bar y vertical bar < 0.5. The transverse momentum dependence of the Xi(0)(c) baryon production relative to the D-0 meson production is compared to predictions of event generators with various tunes of the hadronisation mechanism, which are found to underestimate the measured cross-section ratio. (C) 2018 The Author(s). Published by Elsevier B.V
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