17,252 research outputs found

    Secondary compression of clays as a local dehydration process

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    The model equation of soliton theory

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    We consider an hierarchy of integrable 1+2-dimensional equations related to Lie algebra of the vector fields on the line. The solutions in quadratures are constructed depending on nn arbitrary functions of one argument. The most interesting result is the simple equation for the generating function of the hierarchy which defines the dynamics for the negative times and also has applications to the second order spectral problems. A rather general theory of integrable 1+1-dimensional equations can be developed by study of polynomial solutions of this equation under condition of regularity of the corresponding potentials.Comment: 17

    Towards a theory of differential constraints of a hydrodynamic hierarchy

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    We present a theory of compatible differential constraints of a hydrodynamic hierarchy of infinite-dimensional systems. It provides a convenient point of view for studying and formulating integrability properties and it reveals some hidden structures of the theory of integrable systems. Illustrative examples and new integrable models are exhibited.Comment: Published by JNMP at http://www.sm.luth.se/math/JNMP

    FeNi-based magnetoimpedance multilayers: Tailoring of the softness by magnetic spacers

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    The microstructure and magnetic properties of sputtered permalloy films and FeNi(170 nm)/X/FeNi(170 nm) (X=Co, Fe, Gd, Gd-Co) sandwiches were studied. Laminating of the thick FeNi film with various spacers was done in order to control the magnetic softness of FeNi-based multilayers. In contrast to the Co and Fe spacers, Gd and Gd-Co magnetic spacers improved the softness of the FeNi/X/FeNi sandwiches. The magnetoimpedance responses were measured for [FeNi/Ti(6 nm)] 2/FeNi and [FeNi/Gd(2 nm)] 2/FeNi multilayers in a frequency range of 1-500 MHz: for all frequencies under consideration the highest magnetoimpedance variation was observed for [FeNi/Gd(2 nm)] 2/FeNi multilayers. © 2012 American Institute of Physics

    `Interpolating' differential reductions of multidimensional integrable hierarchies

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    We transfer the scheme of constructing differential reductions, developed recently for the case of the Manakov-Santini hierarchy, to the general multidimensional case. We consider in more detail the four-dimensional case, connected with the second heavenly equation and its generalization proposed by Dunajski. We give a characterization of differential reductions in terms of the Lax-Sato equations as well as in the framework of the dressing method based on nonlinear Riemann-Hilbert problem.Comment: Based on the talk at NLPVI, Gallipoli, 15 page

    Manage entropy in Architectural Projects: assuming commitments and ordering diversity

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    It was primary to transfer to the student the importance of his own responsibility on the project, transcending the usual condition of mere academic practice in the school. Their projects are already real actions to transform the reality from the moment in which are the product of a responsible and critical thinking. To the regular development of the Subject of Architectural Projects with theoretical classes and collective corrections in Workshop of Projects, it was incorporated a series of methodologies to activate the individual and collective learning. The project critically acts on city model, proposes an architectural intervention with transformative will and the classroom becomes a social space where individual engagements and collective engagements are added. This dialectic with reality was concluded with the exhibition of projects, which the students explained to the neighbours as the end of the course, first in school and finally in their civic center.Fue primordial transferir al estudiante la importancia de su propia responsabilidad sobre el proyecto, trascendiendo la habitual condición de mera práctica escolar en la Escuela. Sus proyectos son ya verdaderas acciones para transformar la realidad desde el momento mismo en que son el producto de un pensamiento crítico y responsable. Al desarrollo habitual de la Asignatura de Proyectos Arquitectónicos con clases teóricas y correcciones colectivas en Taller de Proyectos se incorporan una serie de metodologías para activar individual y colectivamente el aprendizaje. El proyecto actúa críticamente sobre el modelo de ciudad, propone una intervención arquitectónica con voluntad transformadora y el aula se convierte en un espacio social donde se suman compromisos individuales y compromisos colectivos. Esta dialéctica con la realidad se concluyó con la exposición de los proyectos realizados, que los estudiantes explicaron ante los vecinos del barrio como final de curso, en la Escuela y en su Centro Cívico

    On the Whitham hierarchy: dressing scheme, string equations and additional symmetrie

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    A new description of the universal Whitham hierarchy in terms of a factorization problem in the Lie group of canonical transformations is provided. This scheme allows us to give a natural description of dressing transformations, string equations and additional symmetries for the Whitham hierarchy. We show how to dress any given solution and prove that any solution of the hierarchy may be undressed, and therefore comes from a factorization of a canonical transformation. A particulary important function, related to the τ\tau-function, appears as a potential of the hierarchy. We introduce a class of string equations which extends and contains previous classes of string equations considered by Krichever and by Takasaki and Takebe. The scheme is also applied for an convenient derivation of additional symmetries. Moreover, new functional symmetries of the Zakharov extension of the Benney gas equations are given and the action of additional symmetries over the potential in terms of linear PDEs is characterized

    Hodograph solutions of the dispersionless coupled KdV hierarchies, critical points and the Euler-Poisson-Darboux equation

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    It is shown that the hodograph solutions of the dispersionless coupled KdV (dcKdV) hierarchies describe critical and degenerate critical points of a scalar function which obeys the Euler-Poisson-Darboux equation. Singular sectors of each dcKdV hierarchy are found to be described by solutions of higher genus dcKdV hierarchies. Concrete solutions exhibiting shock type singularities are presented.Comment: 19 page

    Magic Numbers for the Photoelectron Anisotropy in Li-Doped Dimethyl Ether Clusters

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    Photoelectron velocity map imaging of Li(CH3_3OCH3_3)n_n clusters (1 \leq n \leq 175) is used to search for magic numbers related to the photoelectron anisotropy. Comparison with density functional calculations reveals magic numbers at n=4, 5, and 6, resulting from the symmetric charge distribution with high s-character of the highest occupied molecular orbital. Since each of these three cluster sizes correspond to the completion of a first coordination shell, they can be considered as 'isomeric motifs of the first coordination shell'. Differences in the photoelectron anisotropy, the vertical ionization energies and the enthalpies of vaporization between Li(CH3_3OCH3_3)n_n and Na(CH3_3OCH3_3)n_n can be rationalized in terms of differences in their solvation shells, atomic ionization energies, polarizabilities, metal-oxygen bonds, ligand-ligand interactions, and by cooperative effects
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