15,273 research outputs found

    Cavitation Inception - A Selective Review

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    This paper reviews recent developments in selected cavitation research areas which have been active mainly within the past two years. The new understanding resulting from this work is summarized. Research topics discussed are cavitation inception on smooth surfaces, on vortex cavitation and scaling, on the measurement of cavitation nuclei, and on the effects of polymer additives. Because of the selective nature of the review, a fairly comprehensive listing of recent contributions to the literature on these and related aspects of cavitation research is an essential part of the exposition

    Simple permutations with order 4n+24n + 2. Part I

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    The problem of genealogy of permutations has been solved partially by Stefan (odd order) and Acosta-Hum\'anez & Bernhardt (power of two). It is well known that Sharkovskii's theorem shows the relationship between the cardinal of the set of periodic points of a continuous map, but simple permutations will show the behavior of those periodic points. This paper studies the structure of permutations of mixed order 4n+24n+2, its properties and a way to describe its genealogy by using Pasting and Reversing.Comment: 17 page

    Pasting and Reversing Approach to Matrix Theory

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    The aim of this paper is to study some aspects of matrix theory through Pasting and Reversing. We start giving a summary of previous results concerning to Pasting and Reversing over vectors and matrices, after we rewrite such properties of Pasting and Reversing in matrix theory using linear mappings to finish with new properties and new sets in matrix theory involving Pasting and Reversing. In particular we introduce new linear mappings: Palindromicing and Antipalindromicing mappings, which allow us to obtain palindromic and antipalindromic vectors and matrices.Comment: 19 page

    Some Remarks on a Generalized Vector Product

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    In this paper we use a generalized vector product to construct an exterior form ∧:(Rn)k→R(nk)\wedge :(\mathbb{R}^{n}) ^{k}\to \mathbb{R}^{\binom{n}{k}}, where (nk)=n!(n−k)!k!\binom{n}{k}=\frac{n!}{(n-k)!k!}, k≤nk\leq n. Finally, for n=k−1n=k-1 we introduce the reversing operation to study this generalized vector product over palindromic and antipalindromic vectors.Comment: 10 pages, 14 pages in the published version: Revista Integraci\'o

    Variations for Some Painlev\'e Equations

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    This paper first discusses irreducibility of a Painlev\'e equation PP. We explain how the Painlev\'e property is helpful for the computation of special classical and algebraic solutions. As in a paper of Morales-Ruiz we associate an autonomous Hamiltonian H\mathbb{H} to a Painlev\'e equation PP. Complete integrability of H\mathbb{H} is shown to imply that all solutions to PP are classical (which includes algebraic), so in particular PP is solvable by ''quadratures''. Next, we show that the variational equation of PP at a given algebraic solution coincides with the normal variational equation of H\mathbb{H} at the corresponding solution. Finally, we test the Morales-Ramis theorem in all cases P2P_{2} to P5P_{5} where algebraic solutions are present, by showing how our results lead to a quick computation of the component of the identity of the differential Galois group for the first two variational equations. As expected there are no cases where this group is commutative
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