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Chian A.C.-L.,National Institute for Space Research | Chian A.C.-L.,French National Center for Scientific Research | Chian A.C.-L.,University of Adelaide | Rempel E.L.,National Institute for Space Research | And 6 more authors.
Astrophysical Journal | Year: 2014

We study coherent structures in solar photospheric flows in a plage in the vicinity of the active region AR 10930 using the horizontal velocity data derived from Hinode/Solar Optical Telescope magnetograms. Eulerian and Lagrangian coherent structures (LCSs) are detected by computing the Q-criterion and the finite-time Lyapunov exponents of the velocity field, respectively. Our analysis indicates that, on average, the deformation Eulerian coherent structures dominate over the vortical Eulerian coherent structures in the plage region. We demonstrate the correspondence of the network of high magnetic flux concentration to the attracting Lagrangian coherent structures (aLCSs) in the photospheric velocity based on both observations and numerical simulations. In addition, the computation of aLCS provides a measure of the local rate of contraction/expansion of the flow. © 2014. The American Astronomical Society. All rights reserved.


Gomes V.E.D.O.,Institute of Aeronautical Technology ITA | Gomes V.E.D.O.,iversity Magdeburg | Gomes J.D.O.,Institute of Aeronautical Technology ITA | Grote K.-H.,iversity Magdeburg
Re-Engineering Manufacturing for Sustainability - Proceedings of the 20th CIRP International Conference on Life Cycle Engineering | Year: 2013

A sustainable layout planning should provide a resource-efficient state. Companies face the facility layout problem not only when they create a new manufacturing system but also when they expand or modify existing systems. In these cases, a proper evaluation of manufacturing is a fundamental step to identify opportunities for improvement and to increase energy efficiency in production. This paper discusses a systematic approach for layout modification, which includes an assessment of energy efficiency, inserted into kaizen event. A case study was conducted, as a contribution towards this discussion.


Chian A.C.-L.,National Institute for Space Research | Chian A.C.-L.,French National Center for Scientific Research | Chian A.C.-L.,Institute of Aeronautical Technology ITA | Munoz P.R.,National Institute for Space Research | And 3 more authors.
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2013

The edge of chaos is analyzed in a spatially extended system, modeled by the regularized long-wave equation, prior to the transition to permanent spatiotemporal chaos. In the presence of coexisting attractors, a chaotic saddle is born at the basin boundary due to a smooth-fractal metamorphosis. As a control parameter is varied, the chaotic transient evolves to well-developed transient turbulence via a cascade of fractal-fractal metamorphoses. The edge state responsible for the edge of chaos and the genesis of turbulence is an unstable traveling wave in the laboratory frame, corresponding to a saddle point lying at the basin boundary in the Fourier space. © 2013 American Physical Society.


Asenjo F.A.,University of Texas at Austin | Borotto F.A.,University of Concepción | Chian A.C.-L.,French National Center for Scientific Research | Chian A.C.-L.,Chilean Center of Nanosciences and Nanotechnology | And 5 more authors.
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2012

We develop a nonlinear theory for self-modulation of a circularly polarized electromagnetic wave in a relativistic hot weakly magnetized electron-positron plasma. The case of parallel propagation along an ambient magnetic field is considered. A nonlinear Schrödinger equation is derived for the complex wave amplitude of a self-modulated wave packet. We show that the maximum growth rate of the modulational instability decreases as the temperature of the pair plasma increases. Depending on the initial conditions, the unstable wave envelope can evolve nonlinearly to either periodic wave trains or solitary waves. This theory has application to high-energy astrophysics and high-power laser physics. © 2012 American Physical Society.

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