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École Centrale Paris is a French university-level institution in the field of engineering. It is also known by its original name École Centrale des Arts et Manufactures, or ECP and its famous alumni are called Centraliens. Founded in 1829, it is one of the oldest and most prestigious engineering schools in France and has the special status of Grand établissement. École Centrale Paris offers graduate degree programs as well as PhD opportunities.École Centrale Paris is one of the Centrale Graduate Schools associated as the Groupe Centrale network with its sister institutions and Casablanca). It was the founding party in 1988 of the TIME network, that enables student exchanges among leading European engineering schools. It is also a member of the UniverSud Paris and the CESAER association of European engineering schools.The school, reputed for its international orientation, has partnerships with the best universities all over the world, such as Harvard University, Massachusetts Institute of Technology, Oxford University, Columbia University, RWTH Aachen University, ETH Zurich, Cornell University, Dartmouth College, Northwestern University, University of California, Berkeley, University of Chicago, National University of Singapore, KAIST, Tsinghua University and University of PekingIn 2013, the fusion with Supelec will start. Wikipedia.

Cottereau R.,Ecole Centrale Paris
International Journal for Numerical Methods in Engineering | Year: 2013

This paper presents a numerical strategy that allows to lower the costs associated to the prediction of the value of homogenized tensors in elliptic problems. This is performed by solving a coupled problem, in which the complex microstructure is confined to a small region and surrounded by a tentative homogenized medium. The characteristics of this homogenized medium are updated using a self-consistent approach and are shown to converge to the actual solution. The main feature of the coupling strategy is that it really couples the random microstructure with the deterministic homogenized model, and not one (deterministic) realization of the random medium with a homogenized model. The advantages of doing so are twofold: (a) the influence of the boundary conditions is significantly mitigated, and (b) the ergodicity of the random medium can be used in full through appropriate definition of the coupling operator. Both of these advantages imply that the resulting coupled problem is less expensive to solve, for a given bias, than the computation of homogenized tensor using classical approaches. Examples of 1-D and 2-D problems with continuous properties, as well as a 2-D matrix-inclusion problem, illustrate the effectiveness and potential of the method. © 2013 John Wiley & Sons, Ltd. Source

Shvartsman V.V.,University of Duisburg - Essen | Dkhil B.,Ecole Centrale Paris | Kholkin A.L.,University of Aveiro
Annual Review of Materials Research | Year: 2013

Ferroelectric relaxors continue to be one of the most mysterious solid-state materials. Since their discovery by Smolenskii and coworkers, there have been many attempts to understand the properties of these materials, which are exotic, yet useful for applications. On the basis of the numerous experimental data, several theories have been established, but none of them can explain all the properties of relaxors. The recent advent of piezoresponse force microscopy (PFM) has allowed for polarization mapping on the surface of relaxors with subnanometer resolution. This development thus leads to the question of whether the polar nanoregions that contribute to diffuse X-ray scattering and a range of macroscopic properties can be visualized. This review summarizes recent advancements in the application of PFM to a number of ferroelectric relaxors and provides a tentative explanation of the peculiar polarization distributions related to the intriguing physical phenomena in these materials. © Copyright © 2013 by Annual Reviews. All rights reserved. Source

Pai D.Z.,Ecole Centrale Paris
Journal of Physics D: Applied Physics | Year: 2011

The application of nanosecond discharges towards nanomaterials synthesis at atmospheric pressure is explored in this perspective article. First, various plasma sources are evaluated in terms of the energy used to include one atom into the nanomaterial, which is shown to depend strongly on the electron temperature. Because of their high average electron temperature, nanosecond discharges could be used to achieve nanofabrication at a lower energy cost, and therefore with better efficiency, than with other plasma sources at atmospheric pressure. Transient spark discharges and nanosecond repetitively pulsed (NRP) discharges are suggested as particularly useful examples of nanosecond discharges generated at high repetition frequency. Nanosecond discharges also generate fast heating and cooling rates that could be exploited to produce metastable nanomaterials. © 2011 IOP Publishing Ltd. Source

Guenneau S.,Fresnel Institute | Amra C.,Fresnel Institute | Veynante D.,Ecole Centrale Paris
Optics Express | Year: 2012

We adapt tools of transformation optics, governed by a (elliptic) wave equation, to thermodynamics, governed by the (parabolic) heat equation. We apply this new concept to an invibility cloak in order to thermally protect a region (a dead core) and to a concentrator to focus heat flux in a small region. We finally propose a multilayered cloak consisting of 20 homogeneous concentric layers with a piecewise constant isotropic diffusivity working over a finite time interval (homogenization approach). © 2012 Optical Society of America. Source

Durville D.,Ecole Centrale Paris
Computational Mechanics | Year: 2012

In this paper we propose a finite element approach which simulates the mechanical behaviour of beam assemblies that are subject to large deformations and that develop contact-friction interactions. We focus on detecting and modeling contact-friction interactions within the assembly of beams. Contact between beams-or between parts of the same beam in the case of self-contact, is detected from intermediate geometries defined within proximity zones associating close parts of beam axes. The discretization of contact-friction interactions is performed on these intermediate geometries by means of contact elements, constituted of pairs of material particles which are predicted to enter into contact. A 3D finite strain beam model is used to represent the behaviour of each beam. This model describes the kinematics of each beam cross-section using nine degrees of freedom, and is therefore able to represent plane deformations of these cross-sections. Algorithms are proposed to solve the global nonlinear problem using an implicit scheme, under quasi-static assumptions. Simulation results of the tightening and releasing of knots made on monofilament and multifilament yarns are shown as an application. Straight fibers are first twisted together to make a yarn, before suitable conditions are applied to their ends to form and tighten the knot. Tightening forces are finally released to obtain an equilibrium configuration of the knot without external forces. © 2012 Springer-Verlag. Source

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