Stability of Big Surface Bubbles: Impact of Evaporation and Bubbles Size

Surface bubbles have attracted much interest in the past decades. In this article, we propose to explore the lifetime and thinning dynamics of centimetric surface bubbles. We study the impact of the bubbles size as well as that of the atmospheric humidity through a careful control and systematic variation of the relative humidity in the measuring chamber. We first adress the question of the drainage under saturated water vapor conditions and show that a model including both capillary and gravity driven drainage provides the best prediction for this process. Additionally, unprecedented statistics on the bubbles lifetimes confirm experimentally that this parameter is set by evaporation to leading order. We make use of a model based on the overall thinning dynamics of the thin film and assume a rupture thickness of the order 10-100 nm to obtain a good representation of these data. For experiments conducted far from saturation, the convective evaporation of the bath is shown to dominate the overall mass loss in the cap film due to evaporation

Face Class Modeling based on Local Appearance for Recognition

International audienceThis work proposes a new formulation of the objects modeling combining geometry and appearance. The object local appearance location is referenced with respect to an invariant which is a geometric landmark. The appearance (shape and texture) is a combination of Harris-Laplace descriptor and local binary pattern (LBP), all is described by the invariant local appearance model (ILAM). We applied the model to describe and learn facial appearances and to recognize them. Given the extracted visual traits from a test image, ILAM model is performed to predict the most similar features to the facial appearance, first, by estimating the highest facial probability, then in terms of LBP Histogram-based measure. Finally, by a geometric computing the invariant allows to locate appearance in the image. We evaluate the model by testing it on different images databases. The experiments show that the model results in high accuracy of detection and provides an acceptable tolerance to the appearance variability

A fast voxelization algorithm for trilinearly interpolated isosurfaces

International audienceIn this work we propose a new method for a fast incremental voxelization of isosurfaces obtained by the trilinear interpolation of 3D data. Our objective consists in the fast generation of subvoxelized iso-surfaces extracted by a point-based technique similar to the Dividing Cubes algorithm. Our technique involves neither an exhaustive scan search process nor a graph-based search approach when generating iso-surface points. Instead an optimized incremental approach is adopted here for a rapid isosurface extraction. With a sufficient sampling subdivision criteria around critical points, the extracted isosurface is both correct and topologically consistent with respect to the piece-wise trilinear interpolant. Furthermore, the discretiza-tion scheme used in our method ensures obtaining thin-one voxel width-isosurfaces as compared to the given by the Dividing Cubes algorithm. The resultant sub-voxelized isosurfaces are efficiently tested against all possible configurations of the trilinear interpolant and real-world datasets

EYE AND GAZE TRACKING ALGORITHM FOR COLLABORATIVE LEARNING SYSTEM

International audienceOur work focuses on the interdisciplinary field of detailed analysis of behaviors exhibited by individuals during sessions of distributed collaboration. With a particular focus on ergonomics, we propose new mechanisms to be integrated into existing tools to enable increased productivity in distributed learning and working. Our technique is to record ocular movements (eye tracking) to analyze various scenarios of distributed collaboration in the context of computer-based training. In this article, we present a low-cost oculometric device that is capable of making ocular measurements without interfering with the natural behavior of the subject. We expect that this device could be employed anywhere that a natural, non-intrusive method of observation is required, and its low-cost permits it to be readily integrated into existing popular tools, particularly E-learning campus

The Life of a Surface Bubble

Surface bubbles are present in many industrial processes and in nature, as well as in CO$_2$ beverage. They have motivated many theoretical, numerical and experimental works. This paper presents the current knowledge on the physics of surface bubbles lifetime and shows the diversity of mechanisms at play that depend on the properties of the bath, the interfaces and the ambient air. In particular, we explore the role of drainage and evaporation on film thinning. We highlight the existence of two different scenarios depending on whether the film cap ruptures at large or small thickness compared to the thickness at which van der Waals interaction come in to play

Pulsation du faisceau - Accelerateur 2,5 MV - VdG

CA

Die XX julii in festo sancti Hieronymi Aemiliani confessoris : Duplex

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Compte-rendu de la table ronde sur la mise en scène de la pièce

Séance présidée par Marie Miguet-Ollagnier, le Vendredi 24 Novembre 1995, de 17h45 à 18h15, dans la salle Georges Fourrier (Faculté des Lettres) à l'occasion du colloque Mythologie de la rébellion dans le théâtre 1890-1910. Avec également Lucile Garbagnati, responsable de la dramaturgie de cette pièce, et Joseph Melcore, auteur de sa mise en scène, et les acteurs. Ouverture de séance Marie Miguet-Ollagnier ouvre la séance en félicitant vivement les organisateurs et les acteurs de ce spectacle..

Elle est là de Nathalie Sarraute

« J'ai d'abord cru que c'était une histoire de 1920 et puis j'ai compris que c'était l'actualité et les camps de concentration », disait un lycéen de première ou de terminale en sortant le 2 avril d'une représentation de Elle est là donnée par le C.D.N. Personne en tout cas ne dira plus, après avoir vu cette pièce de Nathalie Sarraute, que l'auteur de Tropismes porte au théâtre des conversations d'intellectuels ou que règne sur la scène le monde des salons et des cénacles parisiens. Dans l'œu..