288 research outputs found

    Diagnóstico de verminose em ruminantes.

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    Diagnostico laboratorial; Contagem de ovos por grama de fezes (OPG) - tecnica de Gordon & Whitlock; Coprocultura; Sedimentação; Coleta de helmintos através de necropsias.bitstream/item/35891/1/Doc42.pd

    Partitioning a graph into monochromatic connected subgraphs

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    We show that every 2-edge‐colored graph on vertices with minimum degree at least\frac{2n - 5}{3} can be partitioned into two monochromatic connected subgraphs, provided

    Numerical evaluation of pin-bearing strength for the design of bolted connections of pultruded FRP material

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    This paper presents finite-element predictions for the strength of a pultruded fiber-reinforced polymer (FRP) material subjected to pin-bearing loading with hole clearance. One of the distinct modes of failure in steel bolted connections is bearing. It is caused by the compression action from the shaft pressing into the laminate, and when there is no lateral restraint the mechanism observed at maximum load shows brooming for delamination failure. Each lamina in the glass fiber polyester matrix material is modeled as a homogeneous, anisotropic continuum and a relatively very thin resin layer is assumed to contain any delamination cracking between stacked layers. A cohesive zone model is implemented to predict the size and location of the initial delamination, as well as the load-carrying capacity in a pin-bearing specimen. Finite-element simulations (as virtual tests) are performed at the mesoscale level to validate the modeling methodology against experimental strength test results with delamination failure, and to show how pin-bearing strength varies with parameter changes. For an example of the knowledge to be gained for the design of bolted connections, the parameteric study in which the mat reinforcement is either continuous strand or triaxial (+45°/90°/−45°/chopped+45°/90°/−45°/chopped strand) shows the latter does not provide an increase in pin-bearing strength

    On the global uniqueness for the Einstein–Maxwell-scalar field system with a cosmological constant: I. Well posedness and breakdown criterion

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    This paper is the first part of a trilogy dedicated to the following problem: given spherically symmetric characteristic initial data for the Einstein–Maxwell-scalar field system with a cosmological constant ?, with the data on the outgoing initial null hypersurface given by a subextremal Reissner–Nordström black hole event horizon, study the future extendibility of the corresponding maximal globally hyperbolic development (MGHD) as a 'suitably regular' Lorentzian manifold. In this first part we establish well posedness of the Einstein equations for characteristic data satisfying the minimal regularity conditions leading to classical solutions. We also identify the appropriate notion of a maximal solution, from which the construction of the corresponding MGHD follows, and determine breakdown criteria. This is the unavoidable starting point of the analysis; our main results will depend on the detailed understanding of these fundamentals. In the second part of this series (Costa et al 2014, arXiv:1406.7253) we study the stability of the radius function at the Cauchy horizon. In the third and final paper (Costa et al 2014,arXiv:1406.7261) we show that, depending on the decay rate of the initial data, mass inflation may or may not occur; in fact, it is even possible to have (non-isometric) extensions of the spacetime across the Cauchy horizon as classical solutions of the Einstein equations.info:eu-repo/semantics/submittedVersio

    Finite element guidelines for simulation of fibre-tension dominated failures in composite materials validated by case studies

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    This paper presents a finite element modelling methodology to predict the initiation and damage progression in notched composite laminated plates subjected to increasing in-plane tension load. An important feature of the methodology is it does not rely on customized user-subroutines but solely on the analysis capabilities of the general purpose software Abaqus; thus ensuring that the numerical results can be universally reproduced. The methodology presented copes with intralaminar failure modes and uses the Hashin failure criterion to predict the onset of failure (cracking). To account for damage progression after crack initiation there is a fracture energy calculated for each of four failure modes. Four open-hole laminated plates taken from the literature are used for benchmark examples. The predicted ultimate strength based on the analytically-obtained stress-displacement curve was found to be within 10% of the experimental observations. To study the influence of the interaction of having two or three holes across the mid-plane of a pultruded open-hole tension specimen, a parametric study was carried out. The paper ends giving guidelines for the generalized modelling methodology using Abaqus without user-subroutines

    Bolted connections of pultruded GFRP : implications of geometric characteristics on net section failure

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    The results of a three-dimensional finite element study of the net section dominated failure behaviour of pultruded open-hole specimens are presented. Computer models are developed using the general-purpose software Abaqus. Several issues are addressed in the study with respect to the notched plate geometry: (i) thickness of plate, (ii) transverse centre-to-centre spacing of holes (gauge), and (iii) distance from the centre of the hole to the nearest edge. The analytical results provide information on basic performance and the effects of these parameters on strength and damage tolerance performance, thereby furthering the current understanding of pultruded plate-to-plate connection behaviour under static loading. Based on the results, design recommendations for minimum edge distance and gauge spacing for bolts are given

    Privacy and Identity Management in a Layered Pervasive Service Platform

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    Making pervasive computing reality is a challenging task mainly due to the multitude of functional requirements and technological constraints. In parallel to the honourable research progress in specific technologies, the Daidalos project assessed that in future there will be the need for a pervasive service platform with open interfaces in order to simplify service development and provisioning. The success of such a platform depends on the balance of different aspects, e.g. operational costs with revenue potentials, collection of personal data for context-awareness with privacy protection, manual control and transparency with enhanced user experience and simplicity. In this paper we show the Daidalos approach to privacy protection and identity management for a future pervasive service platform and its architecture. We show how user identities are structured to support dynamic context information while following regulations for privacy protection in Europe. Special focus is put on the trade-off between access control for privacy protection and user experience. This is achieved by automated identity selection, automatic derivation of fine-grained access control policies and their deployment. We also present gathered performance data and implementation details of our ID Broker concept

    Virtual characterization of delamination failures in pultruded GFRP angles

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    This paper deals with the application of cohesive zone models to study delamination failures in leg-angles of pultruded glass fibre reinforced polymer material using the general-purpose finite element software Abaqus. The objective of the study is present a finite element modelling methodology that can, for example, help to fill-in knowledge gaps in the available experimental data pertaining to the tying force resistance of angle-cleated jointing in frame construction. It may be used to optimize cleat shape and laminate lay-up (dependent on composite processing method) for the strongest cleat against a minimum cost requirement. A benchmark example taken from literature is used to show that the numerical predictions from the authors’ simulations are reliable. The approach is next used to analyse an equal leg-angle component where one leg is fixed and the other orthogonal leg is being deformed by a tensile force applied over the free end surface. Numerical results from Abaqus are used to show that a lamination produced by the pultrusion processing method fails unstably by delamination cracks radiating around the curved region and extending into the leg panels. As a preliminary study to show the potential of the new modelling methodology it is used to show the influence of the radius of curvature at the junction between the legs on the tying force resistance; based on the load at delamination onset a smaller radius reduces the cleat’s strength

    Incidência do mofo-cinzento da mamoneira em Canto do Buriti, Estado do Piauí.

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