961 research outputs found

    Interação Entre Xilanase, Glicose Oxidase E ácido Ascórbico Na Qualidade Tecnológica De Pão Elaborado Com Farinha Do Trigo Integral

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    This study aimed to verify the performance of xylanase and its interaction with oxidants agents (glucose oxidase and ascorbic acid) on the quality of whole wheat bread. The experiment was based on a central composite rotational design and the Response Surface Methodology was used to analyze the results. None of the xylanase, glucose oxidase or ascorbic acid concentrations within the studied range led to a significant difference in the specific volume. The highest moisture content and the lowest firmness values were reported in the bread with lower and intermediate levels of xylanase and larger amounts of glucose oxidase and ascorbic acid. This effect was observed mainly at the end of the storage period. A minimum amount of xylanase (from 33 to 63 EDX kg-1 flour) showed to be essential for obtaining best results. Levels of ascorbic acid above 63mg kg-1 and glucose oxidase above 91 SRU kg-1 proved to be necessary to offer the beneficial effect of xylanase. © 2016, Universidade Federal de Santa Maria. All rights reserved.46122249225

    Order parameter model for unstable multilane traffic flow

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    We discuss a phenomenological approach to the description of unstable vehicle motion on multilane highways that explains in a simple way the observed sequence of the phase transitions "free flow -> synchronized motion -> jam" as well as the hysteresis in the transition "free flow synchronized motion". We introduce a new variable called order parameter that accounts for possible correlations in the vehicle motion at different lanes. So, it is principally due to the "many-body" effects in the car interaction, which enables us to regard it as an additional independent state variable of traffic flow. Basing on the latest experimental data (cond-mat/9905216) we assume that these correlations are due to a small group of "fast" drivers. Taking into account the general properties of the driver behavior we write the governing equation for the order parameter. In this context we analyze the instability of homogeneous traffic flow manifesting itself in both of the mentioned above phase transitions where, in addition, the transition "synchronized motion -> jam" also exhibits a similar hysteresis. Besides, the jam is characterized by the vehicle flows at different lanes being independent of one another. We specify a certain simplified model in order to study the general features of the car cluster self-formation under the phase transition "free flow synchronized motion". In particular, we show that the main local parameters of the developed cluster are determined by the state characteristics of vehicle motion only.Comment: REVTeX 3.1, 10 pages with 10 PostScript figure

    CFD simulations of the spent fuel pool in the loss of coolant accident

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    Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.The study utilized the computational fluid dynamics (CFD) methodology to investigate the thermal hydraulic behavior during the hypothetical event of normal operation and loss of cooling accident occurring at spent fuel pool. The boiling time, water level decreasing rate, fuel exposure time and temperature response after fuel exposure for the nuclear power plants under the accident were predicted in this study. We also analyze the flow and heat transfer for the single Atrium-10 fuel bundle. The details of the physics will be shown in this study. The results indicate that the fuel temperature in the pool will not exceed 1200°C to avoid the water-metal reaction after failure of RHR system for 4.578 days. We find that the velocity in the bundle are much faster than outside of the bundle under the LOCA accident.dc201

    Spectral Correlation in Incommensurate Multi-Walled Carbon Nanotubes

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    We investigate the energy spectra of clean incommensurate double-walled carbon nanotubes, and find that the overall spectral properties are described by the so-called critical statistics of Anderson metal-insulator transition. In the energy spectra, there exist three different regimes characterized by Wigner-Dyson, Poisson, and semi-Poisson distributions. This feature implies that the electron transport in incommensurate multi-walled nanotubes can be either diffusive, ballistic, or intermediate between them, depending on the position of the Fermi energy.Comment: final version to appear in Phys. Rev. Let

    Observation of Two New N* Peaks in J/psi -> ppinˉp pi^- \bar n and pˉπ+n\bar p\pi^+n Decays

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    The πN\pi N system in decays of J/ψNˉNπJ/\psi\to\bar NN\pi is limited to be isospin 1/2 by isospin conservation. This provides a big advantage in studying NπNN^*\to \pi N compared with πN\pi N and γN\gamma N experiments which mix isospin 1/2 and 3/2 for the πN\pi N system. Using 58 million J/ψJ/\psi decays collected with the Beijing Electron Positron Collider, more than 100 thousand J/ψpπnˉ+c.c.J/\psi \to p \pi^- \bar n + c.c. events are obtained. Besides two well known NN^* peaks at 1500 MeV and 1670 MeV, there are two new, clear NN^* peaks in the pπp\pi invariant mass spectrum around 1360 MeV and 2030 MeV. They are the first direct observation of the N(1440)N^*(1440) peak and a long-sought "missing" NN^* peak above 2 GeV in the πN\pi N invariant mass spectrum. A simple Breit-Wigner fit gives the mass and width for the N(1440)N^*(1440) peak as 1358±6±161358\pm 6 \pm 16 MeV and 179±26±50179\pm 26\pm 50 MeV, and for the new NN^* peak above 2 GeV as 2068±340+152068\pm 3^{+15}_{-40} MeV and 165±14±40165\pm 14\pm 40 MeV, respectively

    Slepton Flavor Nonuniversality, the Muon EDM and its Proposed sensitive Search at Brookhaven

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    We analyze the electric dipole moment of the electron (ded_e), of the neutron (dnd_n) and of the muon (dμd_{\mu}) using the cancellation mechanism in the presence of nonuniversalities of the soft breaking parameters. It is shown that the nonuniversalities in the slepton sector produce a strong violation of the scaling relation dμ/demμ/med_{\mu}/d_e\simeq m_{\mu}/m_e in the cancellation region. An analysis of de,dnd_e, d_n and dμd_{\mu} under the constraints of the current experimental limits on ded_e and dnd_n and under the constraints of the recent Brookhaven result on gμ2g_{\mu}-2 shows that in the non-scaling region dμd_{\mu} can be as large as (1024102310^{-24}-10^{-23})ecm and thus within reach of the recently proposed Brookhaven experiment for a sensitive search for dμd_{\mu} at the level of 102410^{-24} ecm.Comment: 24 pages, Latex, including 5 figures with additional reference

    Semileptonic BppˉνˉB-\to p\bar{p} \ell-\bar{\nu}_\ell decays

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    We study the four-body exclusive semileptonic baryonic Bˉ\bar B decays of BppˉνˉB^-\to p\bar p \ell^- \bar\nu_{\ell} (=e,μ,τ\ell=e,\mu,\tau) in the standard model. We find that their decay branching ratios are about (1.0,1.0,0.5)×104(1.0, 1.0,0.5)\times 10^{-4}, respectively. In particular, the electron mode is close to the corresponding CLEO's upper limit of 5.2×1035.2\times 10^{-3}, while all results are about one or two orders of magnitude larger than the previous estimated values for the inclusive modes of BˉBBˉνˉ\bar B\to {\bf B\bar B'}\ell \bar \nu. Clearly, both B-factories of Belle and BaBar should be able to observe these exclusive four-body modes.Comment: 10 pages, 3 figures, published versio

    Search for B -> h(*) nu nubar Decays at Belle

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    We present a search for the rare decays B -> h(*) nu nubar, where h(*) stands for a light meson. A data sample of 535 million BBbar pairs collected with the Belle detector at the KEKB e+e- collider is used. Signal candidates are required to have an accompanying B meson fully reconstructed in a hadronic mode and signal-side particles consistent with a single h(*) meson. No significant signal is observed and we set upper limits on the branching fractions at 90% confidence level. The limits on B0 -> K*0 nu nubar and B+ -> K+ nu nubar decays are more stringent than the previous constraints, while the first searches for B0 -> K0 nu nubar, pi0 nu nubar, rho0 nu nubar, phi nu nubar and B+ -> K*+ nu nubar, rho+ nu nubar are reported.Comment: 6 pages, 2 figures, submit to PR

    Search for tau -> e gamma decay at Belle

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    We have searched for the lepton-flavor-violating decay tau -> e gamma using a data sample of 86.7/fb collected with the Belle detector at the KEKB asymmetric e^+ e^- collider. No evidence for a signal is obtained, and we set an upper limit for the branching fraction Br(tau -> e gamma) < 3.9 x 10^-7 at the 90% C.L.Comment: 11 pages, 10 figures, ReVTeX4, eps
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