The Relation between Galaxy Activity and the Dynamics of Compact Groups of Galaxies

Peer reviewe

Infrared Surface Brightness Analysis of Galaxies in Compact Groups

Images of 7 Compact groups of galaxies (CG) were obtained using the 2.1m telescope in San Pedro Martir (B.C. Mexico) equipped with the NIR camera CAMILA. The NIR images trace the mass of the galaxies, through the oldest and more evolved stellar populations. The goal of this project is to search for evidence of morphological perturbations correlated with the level of activity (AGN or star formation) of the galaxies. We find that the level of perturbation is well correlated with activity observed in optical spectrocopy (Coziol et al. 2004). Evidence for perturbations decreases from more active groups to less active groups, confirming the classification. Our analysis suggests that galaxies in more active groups are undergoing important transformations due to interaction and merging and that the whole groups is on a merger path. Galaxies in less active CG have gone through similar processes in the recent past and are either in a final merging phase or in equilibrium due to a more massive halo of dark matter.Comment: 2 pages, 1 figure, Proc. ESO Workshop "Groups of galaxies in the nearby Universe", Santiago, Chile, 5-9 Dec. 2005, ESO Astrophysics Symposia, eds. I. Saviane, V. Ivanov & J. Borissova, Springer-Verla

The program FANS-3D (finite analytic numerical simulation 3-dimensional) and its applications

In this study, the program named FANS-3D (Finite Analytic Numerical Simulation-3 Dimensional) is presented. FANS-3D was designed to solve problems of incompressible fluid flow and combined modes of heat transfer. It solves problems with conduction and convection modes of heat transfer in laminar flow, with provisions for radiation and turbulent flows. It can solve singular or conjugate modes of heat transfer. It also solves problems in natural convection, using the Boussinesq approximation. FANS-3D was designed to solve heat transfer problems inside one, two and three dimensional geometries that can be represented by orthogonal planes in a Cartesian coordinate system. It can solve internal and external flows using appropriate boundary conditions such as symmetric, periodic and user specified

Recent progress in the synthesis of nanostructured magnesium hydroxide

This review highlights synthetic routes for producing nanostructured magnesium hydroxide and focuses on how these various preparative approaches can produce Mg(OH)2 nanoparticles with controlled size and morphology. Mg(OH)2 nanocrystals with rod-, needle-, hollow tube- or platelet-like morphology can be synthesised by the modification of chemical and physical experimental parameters such as the selection of magnesium precursor, solvent and temperature or by employing surface modifiers and templates. Techniques based on hydrothermal/solvothermal treatments, microwave heating and (co-)precipitation are dominant in the production of Mg(OH)2 at the nanoscale, but other materials design approaches are now emerging. Bulk Mg(OH)2 has been extensively studied over decades and finds use in a wide range of applications. Moreover, the hydroxide can also serve as a precursor for other commercially important materials such as MgO. Nanostructuring the material has proven extremely useful in modifying some of its most important properties – not least enhancing the performance of Mg(OH)2 as a non-toxic flame retardant – but equally it is creating new avenues of applied research. We evaluate herein the latest efforts to design novel synthesis routes to nano-Mg(OH)2, to understand the mechanisms of crystallite growth and to tailor microstructure towards specific properties and applications

Multi-output Technical Efficiency for Argentinean Dairy Farms Using Stochastic Production and Stochastic Distance Frontiers with Unbalanced Panel Data

Published by Asociación de Economistas Agrarios de ChileArgentina, dairy farms, panel data, stochastic production and stochastic distance frontiers, technical efficiency, Production Economics, Productivity Analysis,

Generalised verification of the observer property in discrete event systems

The observer property is an important condition to be satisfied by abstractions of Discrete Event Systems (DES) models. This paper presents a generalised version of a previous algorithm which tests if an abstraction of a DES obtained through natural projection has the observer property. The procedure called OP-verifier II overcomes the limitations of the previously proposed verifier while keeping its computational complexity. Results are illustrated by a case study of a transfer line system

Generalised verification of the observer property in discrete event systems

The observer property is an important condition to be satisfied by abstractions of Discrete Event Systems (DES) models. This paper presents a generalised version of a previous algorithm which tests if an abstraction of a DES obtained through natural projection has the observer property. The procedure called OP-verifier II overcomes the limitations of the previously proposed verifier while keeping its computational complexity. Results are illustrated by a case study of a transfer line system