4,138 research outputs found

    Rare top quark decays in extended models

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    Flavor changing neutral currents (FCNC) decays t to H + c, t to Z + c, and H to t + bar{c} are discussed in the context of Alternative Left-Right symmetric Models (ALRM) with extra isosinglet heavy fermions where FCNC decays may take place at tree-level and are only suppressed by the mixing between ordinary top and charm quarks, which is poorly constraint by current experimental values. The non-manifest case is also briefly discussed.Comment: Contributed talk given at the 10th Mexican Workhop on Particles and Fields, Morelia, Michoacan, Mexico, 7-12 Nov 200

    From vortex molecules to the Abrikosov lattice in thin mesoscopic superconducting disks

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    Stable vortex states are studied in large superconducting thin disks (for numerical purposes we considered with radius R = 50 \xi). Configurations containing more than 700 vortices were obtained using two different approaches: the nonlinear Ginzburg-Landau (GL) theory and the London approximation. To obtain better agreement with results from the GL theory we generalized the London theory by including the spatial variation of the order parameter following Clem's ansatz. We find that configurations calculated in the London limit are also stable within the Ginzburg-Landau theory for up to ~ 230 vortices. For large values of the vorticity (typically, L > 100), the vortices are arranged in an Abrikosov lattice in the center of the disk, which is surrounded by at least two circular shells of vortices. A Voronoi construction is used to identify the defects present in the ground state vortex configurations. Such defects cluster near the edge of the disk, but for large L also grain boundaries are found which extend up to the center of the disk.Comment: 15 pages, 10 figures, RevTex4, submitted to Phys. Rev.

    A semantic web service-based architecture for the interoperability of e-government services

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    We propose a semantically-enhanced architecture to address the issues of interoperability and service integration in e-government web information systems. An architecture for a life event portal based on Semantic Web Services (SWS) is described. The architecture includes loosely-coupled modules organized in three distinct layers: User Interaction, Middleware and Web Services. The Middleware provides the semantic infrastructure for ontologies and SWS. In particular a conceptual model for integrating domain knowledge (Life Event Ontology), application knowledge (E-government Ontology) and service description (Service Ontology) is defined. The model has been applied to a use case scenario in e-government and the results of a system prototype have been reported to demonstrate some relevant features of the proposed approach

    Rubiaceae family: Flora Argentina, history and evolution

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    The Rubiaceae family in Argentina is represented by 41 genera and 146 species, of which 9 spp., 2 subspp., and 1 variety are endemic. The highest concentration and endemism are found in the NE ofthe country, in savannas, rainforests, riverside forests, followed by the NW of Argentina, from sea level to 1000-4000 m in the Andes. They also inhabit the heterogeneous landscape of the Center Region of the country, and few species grow in the Patagonian zone. This work is the contribution to the integral study of the Flora of our country. The beginning of knowledge of Argentina’s vegetation dates back to the mid 19th century, with foreign naturalists attracted by the virgin vegetation of the country. The Academy of Science and the first Institute of Botany were founded in Córdoba, where the herbarium and methodical study of native plants began. The first floristic works were carried out, which were enriched in the 20th century, with the improvement of instruments, development of new methods, which changed the analysis and interpretation of data. Fast means of transportation and communication facilitated the exchange of ideas and the increase in botanical expeditions. Despite the advances in the local botany, a comprehensive work on the country’s flora was still missing. It began with species checklists, regional catalogues and flora from various provinces. At the Instituto Botánica Darwinion (IBODA), the project “Flora Argentina” began methodically with the hand-picking of species bibliography, collection and identification activities. Professor Nélida Bacigalupo began to work there in 1949. She worked for more than 60 years and her publications about Rubiaceae taxa were the first in the country. When we met her, we had the privilege of valuing her predisposition and her wisdom as “Teacher”, which led to the transfer of her knowledge to three generations, for which we express our appreciation and gratitude

    Características do grão de algumas linhagens de soja de tegumento colorido.

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    bitstream/item/65447/1/CTAA-DOCUMENTOS-17-CARACTERISTICAS-DO-GRAO-DE-ALGUMAS-LINHAGENS-DE-SOJA-DE-TEGUMENTO-COLORIDO-FL-.pd

    Soja na alimentação humana.

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    Características físicas, composição química e valor nutritivo. Obtenção e uso dos principais produtos de soja. Produtos não desengordurados. Produtos do óleo bruto. Produtos do farelo desengordurado cru. Produtos de tradição oriental.bitstream/item/65355/1/CTAA-DOCUMENTOS-01-SOJA-NA-ALIMENTACAO-HUMANA-LV-2005-00497.pd
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