1,999 research outputs found

    Role of the inter‐ply microstructure in the consolidation quality of high‐performance thermoplastic composites

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    Consolidation of Carbon Fiber (CF)/high-performance thermoplastic compos-ites is much less understood than the one of their thermoset counterparts. It isusually assumed that the consolidation quality is directly linked to the removalof voids within the sample during consolidation, leading to mechanical proper-ties suitable for aerospace applications. A systematic study of the temporalevolution of CF/polyetherketoneketone (PEKK) samples' microstructure con-solidated under low pressure in a rheometer is related to the increase in inter-laminar shear strength. The results show that despite similar void contentswell-below 1 vol%, samples can present significant differences in ILSS values,from 80 to 95 MPa for cross-ply samples, and from 98 to 112 MPa for unidirec-tional (UD) ones. A microstructural analysis shows that, for these materials,consolidation quality is rather related to a reorganization of the inter-ply, aresin-rich ( 70 vol%) region of typical thickness 10ÎŒm which is slowly repo-pulated in fibers during consolidation

    Constatations hĂ©matologiques au cours d’études sur les maladies respiratoires des volailles (Seconde communication)

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    Lissot Gabriel, Sabatier H. Constatations hĂ©matologiques au cours d’études sur les maladies respiratoires des volailles. (Seconde communication). In: Bulletin de l'AcadĂ©mie VĂ©tĂ©rinaire de France tome 114 n°4, 1961. pp. 153-158

    Advancing our understanding of the EU sports policy: the socio-cultural model of sports regulation and players’ agents

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    This paper explains the development of the socio-cultural dimension of the European Union (EU) sports policy over the course of the decade from 2005 to 2015. By adopting the theoretical lenses of the Advocacy Coalition Framework (ACF), the paper firstly offers a novel perspective on the belief systems of the members of the socio-cultural advocacy coalition that operates within the EU sports policy subsystem. A set of empirical policy core beliefs of the coalition actors reflecting their concerns regarding to sport’s integrity and economic welfare that affect its healthy development is presented and explained as the basic causes of the policy problem, i.e., threats that undermine sport’s specific characteristics. In this light, the paper then illustrates that the coalition members have perceived the issue of players’ agents, in particular problems in the activities of agents in European football, to be detrimental to the integrity of sport. As a result, the issue has been the subject of a considerable policy activity by the coalition actors with a view to establishing an alternative regulatory framework to effectively govern players’ agents. Consequently, the paper elucidates the evolving nature of the socio-cultural model of sports regulation that not only promotes the social role of sport in Europe but now also addresses the problems that affect its well-being and clear image. The paper’s principal method of investigation is based on the content analysis of official policy documents and statements of the coalition actors

    Local and non-local equivalent potentials for p-12C scattering

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    A Newton-Sabatier fixed energy inversion scheme has been used to equate inherently non-local p-12{}^{12}C potentials at a variety of energies to pion threshold, with exactly phase equivalent local ones. Those energy dependent local potentials then have been recast in the form of non-local Frahn-Lemmer interactions.Comment: 15 pages plus 9 figures submitted to Phys. Rev.

    Nonlinear Evolution Equations Invariant Under Schroedinger Group in three-dimensional Space-time

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    A classification of all possible realizations of the Galilei, Galilei-similitude and Schroedinger Lie algebras in three-dimensional space-time in terms of vector fields under the action of the group of local diffeomorphisms of the space \R^3\times\C is presented. Using this result a variety of general second order evolution equations invariant under the corresponding groups are constructed and their physical significance are discussed

    On Integrable Doebner-Goldin Equations

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    We suggest a method for integrating sub-families of a family of nonlinear {\sc Schr\"odinger} equations proposed by {\sc H.-D.~Doebner} and {\sc G.A.~Goldin} in the 1+1 dimensional case which have exceptional {\sc Lie} symmetries. Since the method of integration involves non-local transformations of dependent and independent variables, general solutions obtained include implicitly determined functions. By properly specifying one of the arbitrary functions contained in these solutions, we obtain broad classes of explicit square integrable solutions. The physical significance and some analytical properties of the solutions obtained are briefly discussed.Comment: 23 pages, revtex, 1 figure, uses epsfig.sty and amssymb.st

    Biological Effects of Stellar Collapse Neutrinos

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    Massive stars in their final stages of collapse radiate most of their binding energy in the form of MeV neutrinos. The recoil atoms that they produce in elastic scattering off nuclei in organic tissue create radiation damage which is highly effective in the production of irreparable DNA harm, leading to cellular mutation, neoplasia and oncogenesis. Using a conventional model of the galaxy and of the collapse mechanism, the periodicity of nearby stellar collapses and the radiation dose are calculated. The possible contribution of this process to the paleontological record of mass extinctions is examined.Comment: gzipped PostScript (filename.ps.Z), 12 pages. Final version, Phys. Rev. Lett., in pres
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