The Physics and Mass Assembly of distant galaxies with the E-ELT

One of the main science goal of the future European Extremely Large Telescope will be to understand the mass assembly process in galaxies as a function of cosmic time. To this aim, a multi-object, AO-assisted integral field spectrograph will be required to map the physical and chemical properties of very distant galaxies. In this paper, we examine the ability of such an instrument to obtain spatially resolved spectroscopy of a large sample of massive (0.1<Mstellar<5e11Mo) galaxies at 2<z<6, selected from future large area optical-near IR surveys. We produced a set of about one thousand numerical simulations of 3D observations using reasonable assumptions about the site, telescope, and instrument, and about the physics of distant galaxies. These data-cubes were analysed as real data to produce realistic kinematic measurements of very distant galaxies. We then studied how sensible the scientific goals are to the observational (i.e., site-, telescope-, and instrument-related) and physical (i.e., galaxy-related) parameters. We specifically investigated the impact of AO performance on the science goal. We did not identify any breaking points with respect to the parameters (e.g., the telescope diameter), with the exception of the telescope thermal background, which strongly limits the performance in the highest (z>5) redshift bin. We find that a survey of Ngal galaxies that fulfil the range of science goals can be achieved with a ~90 nights program on the E-ELT, provided a multiplex capability M Ngal/8.Comment: 21 pages, 13 figures, 7 tables. Accepted for publication in MNRA

Projection distortion analysis for flattened image mosaicing from straight uniform generalized cylinders

This paper presents a new approach for reconstructing images mapped or painted on straight uniform generalized cylinders (SUGC). A set of monocular images is taken from different viewpoints in order to be mosaiced and to represent the entire scene in detail. The expressions of the SUGC's projection axis are derived from two cross-sections projected onto the image plane. Based on these axes we derive the SUGC localization in the camera coordinate system. We explain how we can find a virtual image representation when the intersection of the two axes is matched to the image center. We analyze the perspective distortions when flattening a scene which is mapped on a SUGC. We evaluate the lower and the upper bounds of the necessary number of views in order to represent the entire scene from a SUGC, by considering the distortions produced by perspective projection. A region matching based mosaicing method is proposed to be applied on the flattened images in order to obtain the complete scene. The mosaiced scene is visualized on a new synthetic surface by a mapping procedure. The proposed algorithm is used for the representation of mural paintings located on SUGCs with closed cross-sections (circles for columns), or opened cross-sections (ellipses or parabolas for vaults). (C) 2001 Pattern Recognition Society. Published by Elsevier Science Ltd. All rights reserved

Quality Assessment of Oenological Tannins Utilising Global Selectivity Chemical Sensors Array (“Electronic Tongue”)

Oenological tannin is a common name for food additives containing tannins utilised in winemaking practices. The maintaste feature of oenological tannin is the taste sensation of astringency and bitterness. In the present paper, samples ofvarious oenological tannins (oak, chestnut, gall, tara, querbacho, grape seed and grape skin tannins) were analysed bymeans of a tasting panel, measuring the flavour attributes bitterness, astringency, body, duration of flavour and similaritywith wine tannins, and using the array of global selectivity chemical sensors (electronic tongue) “α-ASTREE” Liquid andTaste Analyzer (Alpha M.O.S., Toulouse, France). Principal component analysis of the electronic tongue outputs appliedfor different tannin solutions provides good discrimination according to their chemical nature. Consequently, three mainclasses of oenological tannins, namely gallotannins, ellagitannins and condensed tannins, could be identified and separated.The global output of the electronic tongue is quite responsive to changes in the bitterness and astringency of model quinineand alum solutions and, once calibrated (correlation coefficients of 0.976 (p&lt;0.001) and 0.996 (p&lt;0.001) respectively) couldquantify their concentrations with good precision. The electronic tongue output was found to be correlated with the flavourattributes of oenological tannins. The best correlation was observed for bitterness. This fact could be explained by moreconstant calibration and lesser influence of any interfering factors on this attribute

L’art public altruiste dans l’Espagne contemporaine: Similitudes avec la fonction de l’art selon les théories anarchistes

Nous tâcherons dans cet article de faire un lien entre la conception sociale que se faisaient les anarchistes de l’art et celle des artistes de street art contemporain en Espagne, appelé aussi art public indépendant par le chercheur Javier Abarca . Pour bien comprendre sa portée altruiste, nous proposons d’abord d’explorer différents champs taxinomiques. Nous nous intéresserons ensuite au parcours et aux œuvres de certains artistes engagés. Enfin, nous verrons quelles sont les similitudes entre la démarche de ces artistes contemporains et l’aspiration à un changement social voulu par le « modèle éducationiste-réalisateur » libertaire

Preparation and characterization of electrolytic alumina deposit on austenitic stainless steel

Conversion coating modified by alumina has been studied as a way for improving the resistance to thermal oxidation of an austenitic stainless steel. Conversion coating, characterized by a particular morphology and strong interfacial adhesion with the substrate, facilitate the electrochemical deposition of ceramic layers and enhance their adhesion to the substrate. The influence of the current density and treatment time on alumina deposit was studied using statistical experimental designs like Doehlert uniform shell design. After heating, coatings present a continuous composition gradient with refractory compounds at the surface. The behavior at high temperature (1000 8C) of the alumina coating was investigated. The presence of alumina increases the oxidation resistance of an austenitic stainless steel at 1000 8C. The morphology and the chemical composition of the deposit are analyzed. Results on the thermal stability of coating on austenitic stainless steel are presented