207 research outputs found

    Sensitivity on Earth Core and Mantle densities using Atmospheric Neutrinos

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    Neutrino radiography may provide an alternative tool to study the very deep structures of the Earth. Though these measurements are unable to resolve the fine density layer features, nevertheless the information which can be obtained are independent and complementary to the more conventional seismic studies. The aim of this paper is to assess how well the core and mantle averaged densities can be reconstructed through atmospheric neutrino radiography. We find that about a 2% sensitivity for the mantle and 5% for the core could be achieved for a ten year data taking at an underwater km^3 Neutrino Telescope. This result does not take into account systematics related to the details of the experimental apparatus.Comment: 11 pages, 11 figures, accepted for publication in JCA

    Performance And Economic Analysis Of Finished Lambs In Feedlot

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    This study aimed to evaluate animal performance and economic performance of feedlot crossbred lambs (Santa Inês+ - Suffolk) fed different diets based on hay from Cynodon dactylon genotypes, through the use of financial measures considering only the period of feedlot, without relating it to the complete management cycle. A total of 30 intact crossbred Suffolk lambs, identified with earrings, with an average age of 90 days and an average body weight of 21.5 kg were used in this study. Diets were formulated using as treatments a standard concentrate and hay of the Cynodon dactylon genotypes Jiggs, Vaquero, Tifton 68, Coast-Cross, Tifton 85 and Russell in a 60:40 forage-to-concentrate ratio. The treatments were distributed in a randomized complete block design with five replicates. There were significant differences between diets in terms of total expenditure on food, and the highest values were obtained for the Jiggs genotype (BRL 48.96/animal). The animals fed diets based on Tifton 68 hay had a higher rate of return (2.16%) and profitability (34.63%) compared to the other diets. The use of diets based on Tifton 68 hay for feedlot lambs in the finishing phase brings higher economic returns compared to the remaining diets.37129330

    Growth inhibitory effects of 3′-nitro-3-phenylamino nor-beta-lapachone against HL-60: A redox-dependent mechanism

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    AbstractIn this study, the cytotoxicity, genotoxicity and early ROS generation of 2,2-dimethyl-(3H)-3-(N-3′-nitrophenylamino)naphtho[1,2-b]furan-4,5-dione (QPhNO2) were investigated and compared with those of its precursor, nor-beta-lapachone (nor-beta), with the main goal of proposing a mechanism of antitumor action. The results were correlated with those obtained from electrochemical experiments held in protic (acetate buffer pH 4.5) and aprotic (DMF/TBABF4) media in the presence and absence of oxygen and with those from dsDNA biosensors and ssDNA in solution, which provided evidence of a positive interaction with DNA in the case of QPhNO2. QPhNO2 caused DNA fragmentation and mitochondrial depolarization and induced apoptosis/necrosis in HL-60 cells. Pre-treatment with N-acetyl-l-cysteine partially abolished the observed effects related to the QPhNO2 treatment, including those involving apoptosis induction, indicating a partially redox-dependent mechanism. These findings point to the potential use of the combination of pharmacology and electrochemistry in medicinal chemistry

    Demonstration of the temporal matter-wave Talbot effect for trapped matter waves

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    We demonstrate the temporal Talbot effect for trapped matter waves using ultracold atoms in an optical lattice. We investigate the phase evolution of an array of essentially non-interacting matter waves and observe matter-wave collapse and revival in the form of a Talbot interference pattern. By using long expansion times, we image momentum space with sub-recoil resolution, allowing us to observe fractional Talbot fringes up to 10th order.Comment: 17 pages, 7 figure

    Kaon Production and Kaon to Pion Ratio in Au+Au Collisions at \snn=130 GeV

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    Mid-rapidity transverse mass spectra and multiplicity densities of charged and neutral kaons are reported for Au+Au collisions at \snn=130 GeV at RHIC. The spectra are exponential in transverse mass, with an inverse slope of about 280 MeV in central collisions. The multiplicity densities for these particles scale with the negative hadron pseudo-rapidity density. The charged kaon to pion ratios are K+/π=0.161±0.002(stat)±0.024(syst)K^+/\pi^- = 0.161 \pm 0.002 {\rm (stat)} \pm 0.024 {\rm (syst)} and K/π=0.146±0.002(stat)±0.022(syst)K^-/\pi^- = 0.146 \pm 0.002 {\rm (stat)} \pm 0.022 {\rm (syst)} for the most central collisions. The K+/πK^+/\pi^- ratio is lower than the same ratio observed at the SPS while the K/πK^-/\pi^- is higher than the SPS result. Both ratios are enhanced by about 50% relative to p+p and pˉ\bar{\rm p}+p collision data at similar energies.Comment: 6 pages, 3 figures, 1 tabl

    Azimuthal anisotropy and correlations in p+p, d+Au and Au+Au collisions at 200 GeV

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    We present the first measurement of directed flow (v1v_1) at RHIC. v1v_1 is found to be consistent with zero at pseudorapidities η\eta from -1.2 to 1.2, then rises to the level of a couple of percent over the range 2.4<η<42.4 < |\eta| < 4. The latter observation is similar to data from NA49 if the SPS rapidities are shifted by the difference in beam rapidity between RHIC and SPS. Back-to-back jets emitted out-of-plane are found to be suppressed more if compared to those emitted in-plane, which is consistent with {\it jet quenching}. Using the scalar product method, we systematically compared azimuthal correlations from p+p, d+Au and Au+Au collisions. Flow and non-flow from these three different collision systems are discussed.Comment: Quark Matter 2004 proceeding, 4 pages, 3 figure

    Azimuthal anisotropy: the higher harmonics

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    We report the first observations of the fourth harmonic (v_4) in the azimuthal distribution of particles at RHIC. The measurement was done taking advantage of the large elliptic flow generated at RHIC. The integrated v_4 is about a factor of 10 smaller than v_2. For the sixth (v_6) and eighth (v_8) harmonics upper limits on the magnitudes are reported.Comment: 4 pages, 6 figures, contribution to the Quark Matter 2004 proceeding

    Partonic flow and ϕ\phi-meson production in Au+Au collisions at sNN\sqrt{s_{NN}} = 200 GeV

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    We present first measurements of the ϕ\phi-meson elliptic flow (v2(pT)v_{2}(p_{T})) and high statistics pTp_{T} distributions for different centralities from sNN\sqrt{s_{NN}} = 200 GeV Au+Au collisions at RHIC. In minimum bias collisions the v2v_{2} of the ϕ\phi meson is consistent with the trend observed for mesons. The ratio of the yields of the Ω\Omega to those of the ϕ\phi as a function of transverse momentum is consistent with a model based on the recombination of thermal ss quarks up to pT4p_{T}\sim 4 GeV/cc, but disagrees at higher momenta. The nuclear modification factor (RCPR_{CP}) of ϕ\phi follows the trend observed in the KS0K^{0}_{S} mesons rather than in Λ\Lambda baryons, supporting baryon-meson scaling. Since ϕ\phi-mesons are made via coalescence of seemingly thermalized ss quarks in central Au+Au collisions, the observations imply hot and dense matter with partonic collectivity has been formed at RHIC.Comment: 6 pages, 4 figures, submit to PR

    Plasma Wakefield Acceleration with a Modulated Proton Bunch

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    The plasma wakefield amplitudes which could be achieved via the modulation of a long proton bunch are investigated. We find that in the limit of long bunches compared to the plasma wavelength, the strength of the accelerating fields is directly proportional to the number of particles in the drive bunch and inversely proportional to the square of the transverse bunch size. The scaling laws were tested and verified in detailed simulations using parameters of existing proton accelerators, and large electric fields were achieved, reaching 1 GV/m for LHC bunches. Energy gains for test electrons beyond 6 TeV were found in this case.Comment: 9 pages, 7 figure

    The energy dependence of ptp_t angular correlations inferred from mean-ptp_{t} fluctuation scale dependence in heavy ion collisions at the SPS and RHIC

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    We present the first study of the energy dependence of ptp_t angular correlations inferred from event-wise mean transverse momentum fluctuations in heavy ion collisions. We compare our large-acceptance measurements at CM energies $\sqrt{s_{NN}} =$ 19.6, 62.4, 130 and 200 GeV to SPS measurements at 12.3 and 17.3 GeV. $p_t$ angular correlation structure suggests that the principal source of $p_t$ correlations and fluctuations is minijets (minimum-bias parton fragments). We observe a dramatic increase in correlations and fluctuations from SPS to RHIC energies, increasing linearly with $\ln \sqrt{s_{NN}}$ from the onset of observable jet-related fluctuations near 10 GeV.Comment: 10 pages, 4 figure
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