22,748 research outputs found

    First study of the gluon-quark-antiquark static potential in SU(3) Lattice QCD

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    We study the long distance interaction for hybrid hadrons, with a static gluon, a quark and an antiquark with lattice QCD techniques. A Wilson loop adequate to the static hybrid three-body system is developed and, using a 24^3 x 48 periodic lattice with beta=6.2 and a ~ 0.075 fm, two different geometries for the gluon-quark segment and the gluon-antiquark segment are investigated. When these segments are perpendicular, the static potential is compatible with confinement realized with a pair of fundamental strings, one linking the gluon to the quark and another linking the same gluon to the antiquark. When the segments are parallel and superposed, the total string tension is larger and agrees with the Casimir Scaling measured by Bali. This can be interpreted with a type-II superconductor analogy for the confinement in QCD, with repulsion of the fundamental strings and with the string tension of the first topological excitation of the string (the adjoint string) larger than the double of the fundamental string tension.Comment: 4 pages RevTeX, 4 figure

    Towards a knowledge-based system to assist the Brazilian data-collecting system operation

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    A study is reported which was carried out to show how a knowledge-based approach would lead to a flexible tool to assist the operation task in a satellite-based environmental data collection system. Some characteristics of a hypothesized system comprised of a satellite and a network of Interrogable Data Collecting Platforms (IDCPs) are pointed out. The Knowledge-Based Planning Assistant System (KBPAS) and some aspects about how knowledge is organized in the IDCP's domain are briefly described

    Temperature effect on (2+1) experimental Kardar-Parisi-Zhang growth

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    We report on the effect of substrate temperature (T) on both local structure and long-wavelength fluctuations of polycrystalline CdTe thin films deposited on Si(001). A strong T-dependent mound evolution is observed and explained in terms of the energy barrier to inter-grain diffusion at grain boundaries, as corroborated by Monte Carlo simulations. This leads to transitions from uncorrelated growth to a crossover from random-to-correlated growth and transient anomalous scaling as T increases. Due to these finite-time effects, we were not able to determine the universality class of the system through the critical exponents. Nevertheless, we demonstrate that this can be circumvented by analyzing height, roughness and maximal height distributions, which allow us to prove that CdTe grows asymptotically according to the Kardar-Parisi-Zhang (KPZ) equation in a broad range of T. More important, one finds positive (negative) velocity excess in the growth at low (high) T, indicating that it is possible to control the KPZ non-linearity by adjusting the temperature.Comment: 6 pages, 5 figure

    The mechanism for the electrooxidation of procarbazine pharmaceutical preparation in alkaline media and its mathematical description

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    The mechanism for the electrooxidation of procarbazine in alkaline media has been proposed. The process is realized completely on the electrode surface and is adsorption-controlled. The oscillatory behavior in this case is more probable, than for neutral media and may be caused by influences of electrochemical oxidation and salt dissolution from the electrode surface

    Entanglement of random vectors

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    We analytically calculate the average value of i-th largest Schmidt coefficient for random pure quantum states. Schmidt coefficients, i.e., eigenvalues of the reduced density matrix, are expressed in the limit of large Hilbert space size and for arbitrary bipartite splitting as an implicit function of index i.Comment: 8 page

    From an individual approach to a Cluster strategy

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    Portuguese agri-food sector, as well as in Europe, is characterized by being dispersed and pulverized. Nevertheless, in Portugal, the Food and Beverage Industry (F&BI) has the highest rates in terms of turnover of the manufacturing industry - corresponding to 20% (INE - 2009). This sector is a key vector of the economy, contributing the most to the Gross Domestic Product (GDP). Due to the relative small dimension of the domestic market, and its subsequent small scale, companies are obliged to turn to international markets in order to be more competitive

    Pomelos: informações básicas sobre o cultivo e cultivares apirênicas recomendadas para o Rio Grande do Sul.

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    bitstream/CTAA-2009-09/9514/1/documento_198.pd

    Pomelos: informações básicas sobre o cultivo e cultivares apirênicas recomendadas para o Rio Grande do Sul.

    Get PDF
    bitstream/item/33842/1/documento-198.pd
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