5,075 research outputs found

    Coriolis effects on nonlinear oscillations of rotating cylinders and rings

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    The effects which moderately large deflections have on the frequency spectrum of rotating rings and cylinders are considered. To develop the requisite solution, a variationally constrained version of the Lindstedt-Poincare procedure is employed. Based on the solution developed, in addition to considering the effects of displacement induced nonlinearity, the role of Coriolis forces is also given special consideration

    A binary system of complementizers in Cimbrian relative clauses

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    The system of Cimbrian relative clauses manifests itself in a complex scenario: two different complementizers occur in this context: i) the ‘autochthonous’ (Germanic) bo, cognate of Southern German wo, and ii) the ‘allochthonous’ ke, borrowed from Italian (che), which is gradually spreading. In our paper we provide empirical evidence for a crucial specialization of both complementizers: the former shows up only in restrictive relative clauses, the latter in both restrictive and non-restrictive relatives, giving rise to a binary system. In our analysis we aim to explain the binary system of Cimbrian relative complementizers directly addressing the general discussion about relative clauses, showing once more the relevance of both linguistic contact and microvariation for the theory of grammar

    Hierarchical Poly Tree Configurations for the Solution of Dynamically Refined Finte Element Models

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    This paper demonstrates how a multilevel substructuring technique, called the Hierarchical Poly Tree (HPT), can be used to integrate a localized mesh refinement into the original finite element model more efficiently. The optimal HPT configurations for solving isoparametrically square h-, p-, and hp-extensions on single and multiprocessor computers is derived. In addition, the reduced number of stiffness matrix elements that must be stored when employing this type of solution strategy is quantified. Moreover, the HPT inherently provides localize 'error-trapping' and a logical, efficient means with which to isolate physically anomalous and analytically singular behavior

    Nonlinear hierarchical substructural parallelism and computer architecture

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    Computer architecture is investigated in conjunction with the algorithmic structures of nonlinear finite-element analysis. To help set the stage for this goal, the development is undertaken by considering the wide-ranging needs associated with the analysis of rolling tires which possess the full range of kinematic, material and boundary condition induced nonlinearity in addition to gross and local cord-matrix material properties

    Thermomechanically induced pre- and postbuckling of general structure

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    An algorithmic solution strategy which enables handling the positive/indefinite stiffness characteristics associated with the pre and postbuckling of structures subject to complex thermomechanical loading fields was developed. The flexibility of the procedure is such that it can be applied to both finite difference and element type simulations. Due to the generality of the algorithmic approach developed, both kinematic and thermal/mechanical type material nonlinearity including inelastic effects can be treated. This includes the possibility of handling completely general thermomechanical boundary conditions. To demonstrate the scheme, the results of several benchmark problems are presented

    Finite element for rotor/stator interactive forces in general engine dynamic simulation. Part 1: Development of bearing damper element

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    A general purpose squeeze-film damper interactive force element was developed, coded into a software package (module) and debugged. This software package was applied to nonliner dynamic analyses of some simple rotor systems. Results for pressure distributions show that the long bearing (end sealed) is a stronger bearing as compared to the short bearing as expected. Results of the nonlinear dynamic analysis, using a four degree of freedom simulation model, showed that the orbit of the rotating shaft increases nonlinearity to fill the bearing clearance as the unbalanced weight increases

    Soluble CD40 ligand can replace the normal T cell-derived CD40 ligand signal to B cells in T cell-dependent activation

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    We have constructed a soluble chimeric fusion protein between the mouse CD8 alpha chain and the mouse CD40 T cell ligand. This protein binds to both human and mouse B cells. By itself it induced a modest degree of B cell proliferation, but together with anti-immunoglobulin (anti-Ig) antibody it greatly stimulated B cell proliferation, as determined by both [3H]thymidine uptake and increase in cell numbers. These data are evidence that the CD40 ligand on T cells provides a signal that drives B cell proliferation. This signal is synergistic with that delivered by anti-Ig antibody

    Engine dynamic analysis with general nonlinear finite element codes. Part 2: Bearing element implementation overall numerical characteristics and benchmaking

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    Finite element codes are used in modelling rotor-bearing-stator structure common to the turbine industry. Engine dynamic simulation is used by developing strategies which enable the use of available finite element codes. benchmarking the elements developed are benchmarked by incorporation into a general purpose code (ADINA); the numerical characteristics of finite element type rotor-bearing-stator simulations are evaluated through the use of various types of explicit/implicit numerical integration operators. Improving the overall numerical efficiency of the procedure is improved

    Porous metallosilicates for heterogeneous, liquid-phase catalysis: perspectives and pertaining challenges

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    Porous silicates containing dilute amounts of tri-, tetraand penta-valent metal sites, such as TS-1, Sn-β and Fe- ZSM-5, have recently emerged as state of the art catalysts for a variety of sustainable chemical transformations. In contrast with their aluminosilicate cousins, which are widely employed throughout the refinery industry for gas-phase catalytic transformations, such metallosilicates have exhibited unprecedented levels of performance for a variety of liquidphase catalytic processes, including the conversion of biomass to chemicals, and sustainable oxidation technologies with H2O2. However, despite their unique levels of performance for these new types of chemical transformations, increased utilization of these promising materials is complicated by several factors. For example, their utilization in a liquid, and often polar, medium hinders process intensification (scaleup,catalyst deactivation). Moreover, such materials do not generally exhibit the active-site homogeneity of conventional aluminosilicates, and they typically possess a wide variety of active-site ensembles, only some of which may be directly involved in the catalytic chemistry of interest. Consequently,mechanistic understanding of these catalysts remains relatively low, and competitive reactions are commonly observed. Accordingly, unified approaches towards developing more active, selective and stable porous metallosilicates have not yet been achieved. Drawing on some of the most recent literature in the field, the purpose of this mini review is both to highlight the breakthroughs made with regard to the use of porous metallosilicates as heterogeneous catalysts for liquidphase processing, and to highlight the pertaining challenges that we, and others, aim to overcome during the forthcoming years

    Macro e microporosidade do solo cultivado com adubos verdes perenes consorciados com a bananeira em um sistema sob transição agroecológica em Mato Grosso do Sul.

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    bitstream/item/69053/1/066-carneiro-macro.pdfPublicado também no Cadernos de Agroecologia, v. 7, n.2, 2012
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