918 research outputs found

    The new computer program for three dimensional relativistic hydrodynamical model

    Full text link
    An effective computer program for three dimensional relativistic hydrodynamical model has been developed. It implements a new approach to the early hot phase of relativistic heavy-ion collisions. The computer program simulates time-space evolution of nuclear matter in terms of ideal-fluid dynamics. Equations of motions of hydrodynamics are solved making use of finite difference methods. Commonly-used algorithms of numerical relativistic hydrodynamics RHLLE and MUSTA-FORCE have been applied in simulations. To speed-up calculations, parallel processing has been made available for solving hydrodynamical equations. The test results of simulations for 3D, 2D and Bjorken expansion are reported in this paper. As a next step we plan to implement the hadronization algorithm by implementing the continuous particle emission for freeze-out and comparing it with Cooper-Frye formula.Comment: Quark Matter 2005 Poster Session Proceedin

    A pilot, prospective evaluation of a novel alternative for maintenance therapy of breast cancer-associated lymphedema [ISRCTN76522412]

    Get PDF
    BACKGROUND: Prospective investigations of complete decongestive lymphatic physiotherapy (CDPT), including manual lymphatic drainage (MLD), have validated the efficacy of these interventions for the initial reduction of edema and long-term maintenance of limb volume in lymphedema. However, CDPT demands substantial time and effort from patients to maintain these benefits; the treatments are not always well-accepted, and patients may suffer from a deterioration in quality-of-life or a time-dependent loss of initial treatment benefits. A new device designed for home use by the patient, the Flexitouch™, has been developed to mechanically simulate MLD. We have undertaken a prospective, randomized, crossover study of the efficacy of the Flexitouch™, when compared to massage, in the self-administered maintenance therapy of lymphedema. METHODS: A prospective, randomized, crossover study of maintenance therapy was performed in 10 patients with unilateral breast cancer-associated lymphedema of the arm. Each observation phase included self-administered treatment with the Flexitouch™ or massage, 1 hour daily for 14 days, respectively, followed by crossover to the alternate treatment phase. Each treatment phase was preceded by a 1 week treatment washout, with use of garment only. The sequence of treatment was randomly assigned. The potential impact of treatment modality on quality of life was assessed with serial administration of the SF-36. RESULTS: Statistical analysis disclosed that the order of treatment had no outcome influence, permitting 10 comparisons within each treatment group. Post-treatment arm volume reduced significantly after the Flexitouch™, but not after self-administered massage. The patients' mean weight decreased significantly with Flexitouch™ use, but not with massage. The Flexitouch™ device was apparently well-tolerated and accepted by patients. Serial SF-36 administration showed no deterioration in physical or psychosocial scores compared to baseline measurements; there were no statistical differences in scores when the two treatment modalities were compared. CONCLUSION: This short-term prospective evaluation of the Flexitouch™ suggests that the device may provide better maintenance edema control than self-adiminstered massage in breast cancer-associated lymphedema. The apparent ease of use and reliability of response to the device suggest that further broad-scale testing is warranted

    Building health literacy in a Polish region: protocol for the POWER project in Lower Silesia

    Get PDF
    There is a high prevalence of premature mortality and unhealthy lifestyle behaviours in Lower Silesia in Poland (regional capital is the city of Wroclaw). One plausible reason is low health literacy among this population. Health literacy is one of the most important elements of public health and health promotion endeavours. It can be conceptualised as abroad range of cognitive and social skills as well as knowledge needed by an individual to maintain good health, prevent or manage diseases, and effectively engage with healthcare professionals and resources. The Health Promotion Foundation (HPF), in collaboration with regional institutions and organisations, initiated in 2017 a broad initiative to improve health in this region. The overarching aim of the wider programme is to improve the quality of care among primary care patients. The project stream led by HPF aims to improve knowledge and health-related competences in the population of primary care patients in Lower Silesia. It involves (1) needs assessment based on the analysis of data on health status and neds from 50 participating primary care clinics, followed by (2) development of tailored face-to-face workshops that will be delivered by trained public health students, (3) who will be mentored using train-the-trainer approach. It is anticipated that the project will impact on three main areas in the long term. First, it will lead to creation of a package of workshops that could be delivered to other primary care patients. Second, it will create opportunities for students majoring in public health in the region to become directly involved in activities focused on health education and promotion. Three, it is anticipated that the project will lead to improvements in health and wellbeing among the participating patient groups. The present report describes the scope and method of the project

    Multijet production in neutral current deep inelastic scattering at HERA and determination of α_{s}

    Get PDF
    Multijet production rates in neutral current deep inelastic scattering have been measured in the range of exchanged boson virtualities 10 5 GeV and –1 < η_{LAB}^{jet} < 2.5. Next-to-leading-order QCD calculations describe the data well. The value of the strong coupling constant α_{s} (M_{z}), determined from the ratio of the trijet to dijet cross sections, is α_{s} (M_{z}) = 0.1179 ± 0.0013 (stat.)_{-0.0046}^{+0.0028}(exp.)_{-0.0046}^{+0.0028}(th.)

    Antideuteron and deuteron production in mid-central Pb+Pb collisions at 158AA GeV

    Get PDF
    Production of deuterons and antideuterons was studied by the NA49 experiment in the 23.5% most central Pb+Pb collisions at the top SPS energy of sNN\sqrt{s_{NN}}=17.3 GeV. Invariant yields for dˉ\bar{d} and dd were measured as a function of centrality in the center-of-mass rapidity range 1.2<y<0.6-1.2<y<-0.6. Results for dˉ(d)\bar{d}(d) together with previously published pˉ(p)\bar{p}(p) measurements are discussed in the context of the coalescence model. The coalescence parameters B2B_2 were deduced as a function of transverse momentum ptp_t and collision centrality.Comment: 9 figure

    Phase-space dependence of particle-ratio fluctuations in Pb+Pb collisions from 20A to 158A GeV beam energy

    Full text link
    A novel approach, the identity method, was used for particle identification and the study of fluctuations of particle yield ratios in Pb+Pb collisions at the CERN Super Proton Synchrotron (SPS). This procedure allows to unfold the moments of the unknown multiplicity distributions of protons (p), kaons (K), pions (π\pi) and electrons (e). Using these moments the excitation function of the fluctuation measure νdyn\nu_{\text{\text{dyn}}}[A,B] was measured, with A and B denoting different particle types. The obtained energy dependence of νdyn\nu_{\text{dyn}} agrees with previously published NA49 results on the related measure σdyn\sigma_{\text{dyn}}. Moreover, νdyn\nu_{\text{dyn}} was found to depend on the phase space coverage for [K,p] and [K,π\pi] pairs. This feature most likely explains the reported differences between measurements of NA49 and those of STAR in central Au+Au collisions

    Energy dependence of kaon-to-proton ratio fluctuations in central Pb+Pb collisions from sNN\sqrt{s_{NN}} = 6.3 to 17.3 GeV

    Get PDF
    Kaons and protons carry large parts of two conserved quantities, strangeness and baryon number. It is argued that their correlation and thus also fluctuations are sensitive to conditions prevailing at the anticipated parton-hadron phase boundary. Fluctuations of the (K++K)/(p+pˉ)(\mathrm{K}^+ + \mathrm{K}^-)/(\mathrm{p}+\bar{\mathrm{p}}) and K+/p\mathrm{K}^+/\mathrm{p} ratios have been measured for the first time by NA49 in central Pb+Pb collisions at 5 SPS energies between sNN\sqrt{s_{NN}}= 6.3 GeV and 17.3 GeV. Both ratios exhibit a change of sign in σdyn\sigma_{\mathrm{dyn}}, a measure of non-statistical fluctuations, around sNN\sqrt{s_{NN}} = 8 GeV. Below this energy, σdyn\sigma_{\mathrm{dyn}} is positive, indicating higher fluctuation compared to a mixed event background sample, while for higher energies, σdyn\sigma_{\mathrm{dyn}} is negative, indicating correlated emission of kaons and protons. The results are compared to UrQMD calculations which which give a good description at the higher SPS energies, but fail to reproduce the transition to positive values.Comment: 5 pages, 4 figure

    Production of deuterium, tritium, and 3^3He in central Pb+Pb collisions at 20A, 30A, 40A, 80A, and 158A GeV at the CERN SPS

    Full text link
    Production of dd, tt, and 3^3He nuclei in central Pb+Pb interactions was studied at five collision energies (sNN=\sqrt{s_{NN}}= 6.3, 7.6, 8.8, 12.3, and 17.3 GeV) with the NA49 detector at the CERN SPS. Transverse momentum spectra, rapidity distributions, and particle ratios were measured. Yields are compared to predictions of statistical models. Phase-space distributions of light nuclei are discussed and compared to those of protons in the context of a coalescence approach. The coalescence parameters B2B_2 and B3B_3, as well as coalescence radii for dd and 3^3He were determined as a function of transverse mass at all energies.Comment: 22 pages, 29 figures, 8 tables, for submission to Phys. Rev.

    System-size and centrality dependence of charged kaon and pion production in nucleus-nucleus collisions at 40A GeV and158A GeV beam energy

    Get PDF
    Measurements of charged pion and kaon production are presented in centrality selected Pb+Pb collisions at 40A GeV and 158A GeV beam energy as well as in semi-central C+C and Si+Si interactions at 40A GeV. Transverse mass spectra, rapidity spectra and total yields are determined as a function of centrality. The system-size and centrality dependence of relative strangeness production in nucleus-nucleus collisions at 40A GeV and 158A GeV beam energy are derived from the data presented here and published data for C+C and Si+Si collisions at 158A GeV beam energy. At both energies a steep increase with centrality is observed for small systems followed by a weak rise or even saturation for higher centralities. This behavior is compared to calculations using transport models (UrQMD and HSD), a percolation model and the core-corona approach.Comment: 32 pages, 14 figures, 4 tables, typo table II correcte

    Measurement of event-by-event transverse momentum and multiplicity fluctuations using strongly intensive measures Δ[PT,N]\Delta[P_T, N] and Σ[PT,N]\Sigma[P_T, N] in nucleus-nucleus collisions at the CERN Super Proton Synchrotron

    Full text link
    Results from the NA49 experiment at the CERN SPS are presented on event-by-event transverse momentum and multiplicity fluctuations of charged particles, produced at forward rapidities in central Pb+Pb interactions at beam momenta 20AA, 30AA, 40AA, 80AA, and 158AA GeV/c, as well as in systems of different size (p+pp+p, C+C, Si+Si, and Pb+Pb) at 158AA GeV/c. This publication extends the previous NA49 measurements of the strongly intensive measure ΦpT\Phi_{p_T} by a study of the recently proposed strongly intensive measures of fluctuations Δ[PT,N]\Delta[P_T, N] and Σ[PT,N]\Sigma[P_T, N]. In the explored kinematic region transverse momentum and multiplicity fluctuations show no significant energy dependence in the SPS energy range. However, a remarkable system size dependence is observed for both Δ[PT,N]\Delta[P_T, N] and Σ[PT,N]\Sigma[P_T, N], with the largest values measured in peripheral Pb+Pb interactions. The results are compared with NA61/SHINE measurements in p+pp+p collisions, as well as with predictions of the UrQMD and EPOS models.Comment: 12 pages, 14 figures, to be submitted to PR
    corecore