107 research outputs found

    System size dependence of strange particle yields and spectra at sqrt(s)=17.3 GeV

    Get PDF
    Yields and spectra of strange hadrons (K+, K-, phi, Lambda and Antilambda) as well as of charged pions were measured in near central C+C and Si+Si collisions at 158 AGeV beam energy with the NA49 detector. Together with earlier data for p+p, S+S and Pb+Pb reactions the system size dependence can be studied. Relative strangeness production rises fast and saturates at about 60 participating nucleons; the net hyperon spectra show an increasing shift towards midrapidity for larger colliding nuclei. An interpretation based on the formation of coherent systems of increasing volume is proposed. The transverse mass spectra can be described by a blast wave ansatz. Increasing flow velocity is accompanied by decreasing temperatures for both kinetic and chemical freeze out. The increasing gap between inelastic and elastic decoupling leaves space for rescattering.Comment: 8 pages, 6 figures, Proceedings of the Hot Quarks 2004 worksho

    Effective Rheology of Bubbles Moving in a Capillary Tube

    Full text link
    We calculate the average volumetric flux versus pressure drop of bubbles moving in a single capillary tube with varying diameter, finding a square-root relation from mapping the flow equations onto that of a driven overdamped pendulum. The calculation is based on a derivation of the equation of motion of a bubble train from considering the capillary forces and the entropy production associated with the viscous flow. We also calculate the configurational probability of the positions of the bubbles.Comment: 4 pages, 1 figur

    Eucapnic voluntary hyperpnea challenge can support management of exercise-induced bronchoconstriction in elite swimmers

    Get PDF
    Introduction: This study investigated the use of eucapnic voluntary hyperpnea (EVH) to monitor efficacy of pharmacological therapy in elite swimmers with exercise-induced bronchoconstriction (EIB). Secondly, it evaluated the long-term test-retest repeatability of EVH in this population. Methods: Twenty-seven elite international swimmers were included in this retrospective analysis of comprehensive respiratory assessments. Following an initial “withheld-therapy” assessment, athletes with EIB had been prescribed appropriate pharmacological therapy and returned twelve months later for a follow-up assessment to monitor EIB protection afforded by treatment. EIB-negative athletes had returned to confirm initial diagnosis, as were still reporting persistent respiratory symptoms. Athletes were retrospectively grouped into either “Therapy Adherent Group” (n = 12) or “Repeatability Group” (discontinued therapy at follow-up or EIB-negative, n = 15). Results: Greatest fall in forced expiratory volume in 1 second (ΔFEV1max) was significantly lower following therapy adherence (−11.8 ± 3.8%) compared to initial assessment (−24.0 ± 11.3%; P < .01). “Repeatability Group” ΔFEV1max did not differ significantly between initial assessment (−13.1 ± 4.5%) and follow-up (−12.3 ± 5.6%; P = .32), and showed good agreement (0.6%; −5.9%, 7.1%). Conclusion: A follow-up assessment utilizing EVH is useful in the management of EIB and shows good test-retest repeatability over twelve months in elite swimmers who discontinue treatment or are EIB-negative

    Alignment of the ALICE Inner Tracking System with cosmic-ray tracks

    Get PDF
    37 pages, 15 figures, revised version, accepted by JINSTALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner Tracking System, consists of six cylindrical layers of silicon detectors with three different technologies; in the outward direction: two layers of pixel detectors, two layers each of drift, and strip detectors. The number of parameters to be determined in the spatial alignment of the 2198 sensor modules of the ITS is about 13,000. The target alignment precision is well below 10 micron in some cases (pixels). The sources of alignment information include survey measurements, and the reconstructed tracks from cosmic rays and from proton-proton collisions. The main track-based alignment method uses the Millepede global approach. An iterative local method was developed and used as well. We present the results obtained for the ITS alignment using about 10^5 charged tracks from cosmic rays that have been collected during summer 2008, with the ALICE solenoidal magnet switched off.Peer reviewe

    pengaruh model pembelajaran inductive thinking - deductive thinking terhadap hasil belajar IPS ditinjau dari jenis kelamin siswa kelas VII SMP N 2 KARTASURA

    Get PDF
    ABSTRAK Ulfah Fajar Hayati (K5411064) PENGARUH MODEL PEMBELAJARAN DEDUCTIVE THINKING–INDUCTIVE THINKING DITINJAU DARI JENIS KELAMIN TERHADAP HASIL BELAJAR SISWA KELAS VII SMP NEGERI 2 KARTASURA TAHUN AJARAN 2014/2015 (Materi Pembelajaran Kondisi Geografis dan Penduduk). Proposal Skripsi, Surakarta: Fakultas Keguruan dan Ilmu Pendidikan. Universitas Sebelas Maret. Februari 2015. Tujuan penelitian ini adalah 1) Untuk mengetahui perbedaan hasil belajar IPS materi pembelajaran kondisi geografis dan penduduk antara model pembelajaran deductive thinking dan model pembelajaran induktive thinking pada siswa kelas VII SMP Negeri 2 Kartasura tahun ajaran 2014/2015. 2) Untuk mengetahui perbedaan hasil belajar IPS materi pembelajaran kondisi geografis dan penduduk pada siswa laki-laki yang disampaikan dengan model pembelajaran deductive thinking dan model pembelajaran inductive thinking pada siswa kelas VII SMP Negeri 2 Kartasura tahun ajaran 2014/2015. 3) Untuk mengetahui perbedaan hasil belajar IPS materi pembelajaran kondisi geografis dan penduduk pada siswa perempuan yang disampaikan dengan model pembelajaran deductive thinking dan model pembelajaran inductive thinking pada siswa kelas VII SMP Negeri 2 Kartasura tahun ajaran 2014/2015. 4) Untuk mengetahui pengaruh interaksi antara model pembelajaran dan jenis kelamin terhadap hasil belajar IPS materi pembelajaran kondisi geografis dan penduduk pada siswa kelas VII SMP Negeri 2 Kartasura tahun ajaran 2014/2015. Jenis penelitian ini merupakan penelitian Quasi Eksperimental dengan rencana design grup factorial 2x2. Populasi penelitian adalah kelas VII SMP Negeri 2 Kartasura, Sukoharjo dan sampel penelitian adalah siswa kelas VIID dan VIIA Sampel tersebut diambil dengan menggunakan teknik simple random sampling. Teknik pengumpulan data menggunakan tes dalam bentuk tes obyektif pilihan ganda. Teknik analisis data yang digunakan dengan pengujian hipotesis analisis Anova Dua Arah (Two Way Anova) pada taraf signifikasi 5%

    Resolving the strange behavior of extraterrestrial potassium in the upper atmosphere

    Get PDF
    It has been known since the 1960s that the layers of Na and K atoms, which occur between 80 and 105 km in the Earth's atmosphere as a result of meteoric ablation, exhibit completely different seasonal behavior. In the extratropics Na varies annually, with a pronounced wintertime maximum and summertime minimum. However, K varies semiannually with a small summertime maximum and minima at the equinoxes. This contrasting behavior has never been satisfactorily explained. Here we use a combination of electronic structure and chemical kinetic rate theory to determine two key differences in the chemistries of K and Na. First, the neutralization of K+ ions is only favored at low temperatures during summer. Second, cycling between K and its major neutral reservoir KHCO3 is essentially temperature independent. A whole atmosphere model incorporating this new chemistry, together with a meteor input function, now correctly predicts the seasonal behavior of the K layer

    VHMPID RICH prototype using pressurized C4F8O radiator gas and VUV photon detector

    Get PDF
    A small-size prototype of a new Ring Imaging Cherenkov (RICH) detector using for the first time pressurized C4F8O radiator gas and a photon detector consisting of MWPC equipped with a CsI photocathode has been built and tested at the PS accelerator at CERN. It contained all the functional elements of the detector proposed as Very High Momentum Particle Identification (VHMPID) upgrade for the ALICE experiment at LHC to provide charged hadron track-by-track identification in the momentum range starting from 5 potentially up to 25 GeV/c. In the paper the equipment and its elements are described and some characteristic test results are shown

    A very high momentum particle identification detector

    No full text
    A new detector concept has been investigated to extend the capabilities of heavy-ion collider experiments, represented here through the ALICE detector, in the high transverse momentum (p T region. The resulting Very High Momentum Particle Identification Detector (VHMPID) performs charged hadron identification on a track-by-track basis in the 5 GeV/c < p < 25 GeV/c momentum range and provides heavy-ion experiments with new opportunities to study parton-medium interactions at RHIC and LHC energies, where the creation of deconfined quark-gluon matter has been established. The detector is based on novel advances to the pressurized gaseous ring imaging Cherenkov (RICH) concept, which yield a very compact, high resolution addition to existing heavy-ion experiments. We conclude that in order for the device to yield statistically significant results not only for single particle measurements, but also for di-hadron and jet-tagged correlation studies, it has to cover contiguously up to 30% of a central barrel detector in radial direction. This will allow, for the first time, identified charged hadron measurements in jets. In this paper we summarize the physics motivations for such a device, as well as its conceptual design, layout, and integration into ALICE

    Energy and centrality dependence of (p)over-bar and p production and the (Lambda)over-bar/(p)over-bar ratio in Pb plus Pb collisions between 20A GeV and 158A GeV

    No full text
    The transverse mass m(t) distributions for antiprotons are measured at midrapidity for minimum bias Pb+Pb collisions at 158A GeV and for central Pb+Pb collisions at 20A, 30A, 40A, and 80A GeV beam energies in the fixed target experiment NA49 at the CERN SPS. The rapidity density dn/dy, inverse slope parameter T, and mean transverse mass &lt; m(t)&gt; derived from the m(t) distributions are studied as a function of the incident energy and the collision centrality and compared to the relevant data on proton production. The shapes of the m(t) distributions of (p) over bar and p are very similar. The ratios of the particle yields, (p) over bar /p and (p) over bar/(Lambda) over bar, are also analyzed. The (p) over bar /p ratio exhibits an increase with decreasing centrality and a steep rise with increasing beam energy. The (Lambda) over bar/(Lambda) over bar ratio increases beyond unity with decreasing beam energy
    corecore