2,924 research outputs found

    On rank 2 vector bundles on Fano manifolds

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    In this work we deal with vector bundles of rank two on a Fano manifold XX with b2=b4=1b_2=b_4=1. We study the nef and pseudoeffective cones of the corresponding projectivizations and how these cones are related to the decomposability of the vector bundle. As consequences, we obtain the complete list of P1\mathbb{P}^1-bundles over XX that have a second P1\mathbb{P}^1-bundle structure, classify all the uniform rank two vector bundles on this class of Fano manifolds and show the stability of indecomposable Fano bundles (with one exception on P2\mathbb{P}^2).Comment: Updated version with an issue correcte

    Nestings of rational homogeneous varieties

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    In this paper we study the existence of sections of universal bundles on rational homogeneous varieties -- called nestings -- classifying them completely in the case in which the Lie algebra of the automorphism group of the variety is simple of classical type. In particular we show that, under this hypothesis, nestings do not exist unless there exists a proper algebraic subgroup of the automorphism group acting transitively on the base variety.Comment: Major revision of the exposition. To appear in Tranformation Group

    Uniform families of minimal rational curves on Fano manifolds

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    It is a well-known fact that families of minimal rational curves on rational homogeneous manifolds of Picard number one are uniform, in the sense that the tangent bundle to the manifold has the same splitting type on each curve of the family. In this note we prove that certain --stronger-- uniformity conditions on a family of minimal rational curves on a Fano manifold of Picard number one allow to prove that the manifold is homogeneous

    Las ferias como escaparate de la comunicación empresarial

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    Novenes Jornades de Foment de la Investigació de la FCHS (Any 2003-2004)Análisis de la importancia de las ferias como escaparate de comunicación para las empresas, tomando como ejemplo el sector del azulejo en la provincia de Castellón. Descripción y análisis de por qué se acude a una feria y de los pasos a seguir desde la planificación de la asistencia hasta la finalización de la misma. Por otra parte, análisis de formatos de Relaciones Públicas a través de medios y soportes de comunicación que utilizan las empresas en su asistencia

    Advanced Electron Microscopy Techniques in Nanomaterials Characterization at NASA Glenn Research Center

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    In this chapter, the author will review several advanced microscopy techniques developed at the NASA Glenn Research Center in the last 5 years. Topical areas include: unconventional approach to investigate the fine nanoporous structure of aerogels by scanning electron microscopy, new limits for transmission electron microscopy investigation of dispersion and chirality of single-walled carbon nanotubes within a polymer matrix, the importance of microstructure of porous tin dioxide nanostructure that lead to first time detection of methane at room temperature without doping or catalyst, in situ SEM methods to study the thermal stability of nanoparticles on Graphene/Cu based materials, electron beam irradiation effects on carbon nanotube yarns electrical properties, and nanoindentation work of multiphase thermoelectric material

    Cuatro decenios al servicio de un hospital provincial comarcal

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