Search results for "classical"
showing 10 items of 2294 documents
Spreading dynamics of three-dimensional droplets by the lattice-Boltzmann method
2000
Abstract We have simulated spreading of small droplets on smooth and rough solid surfaces using the three-dimensional lattice-Boltzmann method. We present results for the influence of the initial distance and shape of the drop from the surface on scaling of droplet radius R as a function of time. For relatively flat initial drop shapes our observations are consistent with Tanner's law R ∼ t q , where q =1/10. For increasingly spherical initial shapes, the exponent q increases rapidly being above one half for spherical droplets initially just above the surface. As expected, surface roughness slows down spreading, decreases the final drop radius, and results in irregular droplet shape due to …
The Peregrine soliton in nonlinear fibre optics
2010
International audience; The Peregrine soliton is a localized nonlinear structure predicted to exist over 25 years ago, but not so far experimentally observed in any physical system. It is of fundamental significance because it is localized in both time and space, and because it defines the limit of a wide class of solutions to the nonlinear Schrödinger equation (NLSE). Here, we use an analytic description of NLSE breather propagation to implement experiments in optical fibre generating femtosecond pulses with strong temporal and spatial localization, and near-ideal temporal Peregrine soliton characteristics. In showing that Peregrine soliton characteristics appear with initial conditions th…
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…
Towards a Thermodynamic Description of Supercontinuum Generation
2009
Based on the kinetic wave theory, we describe continuous-wave supercontinuum generation as a thermalization process, i.e., an irreversible evolution of the optical field towards a state of maximum nonequilibrium entropy.
Spectral properties of random non-self-adjoint operators
2015
In this thesis we are interested in the spectral properties of random non-self-adjoint operators. Weare going to consider primarily the case of small random perturbations of the following two types of operators: 1. a class of non-self-adjoint h-differential operators Ph, introduced by M. Hager [32], in the semiclassical limit (h→0); 2. large Jordan block matrices as the dimension of the matrix gets large (N→∞). In case 1 we are going to consider the operator Ph subject to small Gaussian random perturbations. We let the perturbation coupling constant δ be e (-1/Ch) ≤ δ ⩽ h(k), for constants C, k > 0 suitably large. Let ∑ be the closure of the range of the principal symbol. Previous results o…
Heródoto I 53 y su transmisión en la literatura griega cristiana
2013
El oráculo de Delfos ofrece una respuesta al rey lidio Creso que provocará su ataque contra los persas y su propia derrota. Este oráculo que aparece como un hexámetro dactílico por vez primera en la Retórica de Aristóteles llamará la atención de los apologistas cristianos. Pero la transmisión del mismo, a partir de Eusebio de Cesarea, se verá alterada por la interpolación del término ποταμὸν que romperá el esquema métrico del hexámetro. Después podremos distinguir las fuentes de los autores bizantinos que utilizan este oráculo dependiendo de si respetan la forma que nos ofrece Aristóteles o la que aparece en el texto de Eusebio. Así pues, nuestro estudio consistirá en un análisis de la tran…
Celebrating 100 Years of Musical Outreach in Scandinavia
2016
This article outlines the significant, but less investigated historical development of musical outreach; the professional symphony orchestras effort to introduce classical music to new audiences, especially children and adolescents. Many Norwegian symphony orchestras have held public concerts for 100 years and throughout this period they have set up strategic objectives regarding outreach. Through a series of musical examples from various concerts targeting new audiences, the article draws a historical overview of the different concepts of concerts that have developed from the early 1900s till today. In order to better understand the uniqueness of these concerts, and enable us to appreciate…
Boccaccio, «Ninfale fiesolano» 309, 5-8: per la storia di un tópos fra tradizione classica e suggestioni medievali
2022
Questa nota, alla luce della lettura e dell’interpretazione di un passo del «Ninfale fiesolano» del Boccaccio (309, 5-8), ripercorre la fortuna del motivo della “reciprocità” amorosa e, in particolare, dell’intimo rapporto che fa sì che “due” giovani innamorati, legati da affinità di costumi, età, bellezza, siano come “una” sola persona. Un motivo molto antico, questo, che affonda le sue radici nella tradizione biblica e nella letteratura classica, e che conoscerà ampia fortuna nel Medioevo latino e volgare. Fra i testi che vengono proposti e analizzati si segnalano, soprattutto, le «Metamorfosi» di Ovidio, l’«Ero e Leandro» di Museo, il «Narcissus», il «Pamphilus», l’«Alda» di Guglielmo di…
Stability and nature of the volume collapse of ε-Fe2O3 under extreme conditions
2018
Iron oxides are among the major constituents of the deep Earth’s interior. Among them, the epsilon phase of Fe2O3 is one of the less studied polymorphs and there is a lack of information about its structural, electronic and magnetic transformations at extreme conditions. Here we report the precise determination of its equation of state and a deep analysis of the evolution of the polyhedral units under compression, thanks to the agreement between our experiments and ab-initio simulations. Our results indicate that this material, with remarkable magnetic properties, is stable at pressures up to 27 GPa. Above 27 GPa, a volume collapse has been observed and ascribed to a change of the local env…
Condensation of classical optical waves beyond the cubic nonlinear Schrodinger equation
2012
International audience; A completely classical nonlinear wave is known to exhibit a process of condensation whose thermodynamic properties are analogous to those of the genuine Bose-Einstein condensation. So far this phenomenon of wave condensation has been studied essentially in the framework of the nonlinear Schrodinger (NLS) equation with a pure cubic Kerr nonlinearity. We study wave condensation by considering two representative generalizations of the NLS equation that are relevant to the context of nonlinear optics, the nonlocal nonlinearity and the saturable nonlinearity. For both cases we derive analytical expressions of the condensate fraction in the weakly and the strongly nonlinea…