Search results for "Rodin"
showing 10 items of 101 documents
Polarization modulation instability in a Manakov fiber system
2015
International audience; The Manakov model is the simplest multicomponent model of nonlinear wave theory: It describes elementary stable soliton propagation and multisoliton solutions, and it applies to nonlinear optics, hydrodynamics, and Bose-Einstein condensates. It is also of fundamental interest as an asymptotic model in the context of the widely used wavelength-division-multiplexed optical fiber transmission systems. However, although its physical relevance was confirmed by the experimental observation of Manakov (vector) solitons in a planar waveguide in 1996, there have in fact been no quantitative experiments confirming its validity for nonlinear dynamics other than soliton formatio…
On universality of critical behavior in the focusing nonlinear Schrödinger equation, elliptic umbilic catastrophe and the Tritronquée solution to the…
2008
We argue that the critical behavior near the point of “gradient catastrophe” of the solution to the Cauchy problem for the focusing nonlinear Schrodinger equation \(i\epsilon \varPsi _{t}+\frac{\epsilon^{2}}{2}\varPsi _{xx}+|\varPsi |^{2}\varPsi =0\) , e ≪1, with analytic initial data of the form \(\varPsi (x,0;\epsilon)=A(x)e^{\frac{i}{\epsilon}S(x)}\) is approximately described by a particular solution to the Painleve-I equation.
The Fate of Rodinia in the Light of the Discovery of ca. 1000 Ma Old Ophiolites in the Central Asian Orogenic Belt of Siberia
2001
Has the East African Orogen Played Any Role in the Formation and Breakup of the Supercontinent Rodinia and the Amalgamation of Gondwana? New Evidence…
2001
African, southern Indian and South American cratons were not part of the Rodinia supercontinent: evidence from field relationships and geochronology
2003
We discuss the question whether the late Mesoproterozoic and early Neoproterozoic rocks of eastern, central and southern Africa, Madagascar, southern India, Sri Lanka and South America have played any role in the formation and dispersal of the supercontinent Rodinia, believed to have existed between about 1000 and 750 Ma ago. First, there is little evidence for the production of significant volumes of ~1.4–1.0 Ga (Kibaran or Grenvillian age) continental crust in the Mozambique belt (MB) of East Africa, except, perhaps, in parts of northern Mozambique. This is also valid for most terranes related to West Gondwana, which are made up of basement rocks older than Mesoproterozoic, reworked in th…
Synergistic effect between hydrodynamic conditions during Ti anodization and acidic treatment on the photoelectric properties of TiO2 nanotubes
2015
In the present work, the combined influence of controlled hydrodynamic conditions during Ti anodization and the acidic treatment with HClO4 on the photoelectric properties of mixed anatase/rutile TiO2 nanotubes has been studied. Anodized samples were analyzed by means of Field Emission Scanning Electronic Microscopy (FE-SEM), Confocal Raman Microscopy, electrochemical measurements (electrochemical impedance spectroscopy and Mott-Schottky analysis) and photoelectrochemical measurements. It has been observed that the use of hydrodynamic conditions increases the surface area of nanotubes, while acidic treatment enhances their conductivity. Besides, there is a clear synergistic effect between t…
Effects of nonlinearity and substrate’s deformability on modulation instability in NKG equation
2017
International audience; This article investigates combined effects of nonlinearities and substrate's deformability on modulational instability. For that, we consider a lattice model based on the nonlinear Klein-Gordon equation with an on-site potential of deformable shape. Such a consideration enables to broaden the description of energy-localization mechanisms in various physical systems. We consider the strong-coupling limit and employ semi-discrete approximation to show that nonlinear wave modulations can be described by an extended nonlinear Schrodinger equation containing a fourth-order dispersion component. The stability of modulation of carrier waves is scrutinized and the following …
Multicomponent density-functional theory for time-dependent systems
2007
We derive the basic formalism of density functional theory for time-dependent electron-nuclear systems. The basic variables of this theory are the electron density in body-fixed frame coordinates and the diagonal of the nuclear N-body density matrix. The body-fixed frame transformation is carried out in order to achieve an electron density that reflects the internal symmetry of the system. We discuss the implications of this body-fixed frame transformation and establish a Runge-Gross-type theorem and derive Kohn-Sham equations for the electrons and nuclei. We illustrate the formalism by performing calculations on a one-dimensional diatomic molecule for which the many-body Schrodinger equati…
Analysis of the finite difference time domain technique to solve the Schrödinger equation for quantum devices
2004
An extension of the finite difference time domain is applied to solve the Schrödinger equation. A systematic analysis of stability and convergence of this technique is carried out in this article. The numerical scheme used to solve the Schrödinger equation differs from the scheme found in electromagnetics. Also, the unit cell employed to model quantum devices is different from the Yee cell used by the electrical engineering community. A bound for the time step is derived to ensure stability. Several numerical experiments in quantum structures demonstrate the accuracy of a second order, comparable to the analysis of electromagnetic devices with the Yee cell. a!Electronic mail: Antonio.Sorian…
A computational magnetohydrodynamic model of a marine propulsion system
2016
In this article we present an approach to the description of Magnetohydrodynamic Propulsion. Preliminarly, an analytical model which includes an electromagnetic model and a thermal model is presented. Successively, in order to move beyond the analytical model, a 3-D MHD modeling tool and a Runge Kutta method based solver are presented and they are used to investigate an alternative MHD solutions. Some numerical analysis are given.