The Use of an Array Processor for the Simulation of X-ray Topographs

International audienceThe use of a varying-step algorithm now allows the simulation of traverse topographs and of sectiontopographs taking into account the real width of the incident beam. However, computation time remainsa critical factor in practical use. With an array processor it is possible to decrease the computation timesignificantly. It is shown that pictures of good quality may be obtained in a reasonable time using local facilities.The influence of various parameters on the accuracy of the simulations is discussed. It is demonstrated thatlocal machines can be more useful, in crystallography, than giant computers often difficult to reach throughthe network of communications

Validation Test Cases for Multi-Physic Problems: Application to Magneto-Hydrodynamic Numerical Simulations

In the present paper, some elementary test cases in laminar flow with magnetic forcing terms are analyzed (Hartmann flow, Couette flow, Rayleigh flow); equations of the coupled problem are exposed and analytical solutions are derived in each case, highlighting the relevant non-dimensional number which drives the physics of the problem. Several analytical calculations are then proposed and discussed, in particular in the context of MHD propulsion by a nozzle.Comment: 10

Animated simulation of the paths of the wave fields in a crystal containing a dislocation

International audienceWe have simulated the path of X-ray wave fields in a crystal containing a dislocation , using the integration of Takagi-Taupin equations for dynamical theory of diffraction. Computed images for different positions of the core of the dislocation are drawn on a colour picture system in a sequence which give the impression of movement

Visualisation de la répartition d'intensité des rayons X dans un cristal déformé

National audienceNous nous proposons de présenter le résultat d'études théoriques sur la propagation des rayons X dans un cristal contenant une dislocation

Exemples d'utilisations et d'évolutions du graphique et de l'imagerie dans un laboratoire de recherche

National audiencePour les deux aspects graphique et imagerie on présente des exemples d'utilisation typiques dans un laboratoire scientifique; les caractéristiques des matériels et logiciels employés sont citées

Utilisation du plein écran dans un environnement de centre de calcul scientifique

National audienceConvivialité médiocre, ergonomie restreinte sont des reproches souvent justifiés entendus par les responsables de centre informatique, particulièrement en milieu scientifique. Le plein écran offre peut être des solutions permettant de s'affranchir de ces problèmes

Wafer-scale integration of piezoelectric actuation capabilities in nanoelectromechanical systems resonators

In this work, we demonstrate the integration of piezoelectric actuation means on arrays of nanocantilevers at the wafer scale. We use lead titanate zirconate (PZT) as piezoelectric material mainly because of its excellent actuation properties even when geometrically constrained at extreme scal

Wafer-scale integration of piezoelectric actuation capabilities in nanoelectromechanical systems resonators

In this work, we demonstrate the integration of piezoelectric actuation means on arrays of nanocantilevers at the wafer scale. We use lead titanate zirconate (PZT) as piezoelectric material mainly because of its excellent actuation properties even when geometrically constrained at extreme scal

Images Of Serial Sectioning In Electron Microscopy : 3D Visualisation Of Objects Of Biological Interest

International audienceIn the case of serial sections observed by the means of an electron microscope, it is possible to rebuild an image of an object, using the local intelligence of an image workstation without the need of a powerful computer. We will explain the basic principles of a program that we have written and explain its further developments