Comparing galaxy populations in compact and loose groups of galaxies II: brightest group galaxies

The properties of the brightest galaxies (BCGs) are studied in both compact and loose groups of galaxies in order to better understand the physical mechanisms influencing galaxy evolution in different environments. Samples of BCGs are selected in the compact groups identified by McConnachie et al. (2009), and in loose groups taken from Zandivarez & Mart\'inez (2011). The following physical properties of the BCGs in compact groups and in subsamples of loose groups are compared, defined by their mass and total luminosity. The fraction of BCGs classified as red and/or early-type as a function of galaxy luminosity are studied. The fraction of the group's total luminosity contained in the BCG and the difference in luminosity between the BCG and the second-ranked galaxy, are also analysed. Some properties of BCGs in compact and loose groups are comparable. However, BCGs in compact groups are systematically more concentrated and have larger surface brightness than their counterparts in both, high- and low-mass loose groups. The fractions of red and early-type BCGs in compact groups are consistent with those of high-mass loose groups. Comparing BCGs in subsamples of compact and loose groups selected for their similar luminosities, BCGs in compact groups are found to be, on average, brighter, more massive, larger, redder and more frequently classified as elliptical. In compact groups, the BCG contains a larger fraction of the system's total luminosity and differs more in absolute magnitude from the second-ranked galaxy. BCGs in compact and loose groups are found to be different. Some mechanisms responsible for transforming late-type galaxies into early types, such as mergers, may be more effective within compact groups due to their high densities and small velocity dispersion, which would lead their BCGs along somewhat different evolutionary paths.Comment: Accepted for publication in Astronomy & Astrophysics (A&A

Bioinspired fluid-structure interaction problems: gusts, load mitigation and resonance

Mención Internacional en el título de doctorNature often serves as a reference for the design and development of sustainable solutions in numerous different fields. The recent development of small-scale robotic vehicles, asMicro-Air Vehicles (MAVs), is not an exception, and has had an increasingly important impact on society, proposing new alternatives in areas as surveillance or planetary exploration. Trying to mimic the flight of insects and small birds, these devices try to offer more efficient designs and with higher manoeuvrability abilities than the already existing designs. It happens similar with robotic swimmers, with many different existing prototypes. Indeed, it is even possible to find designs of bioinspired small-scale wind turbines based on auto-rotating seeds looking for a more efficient energy harvesting. Besides, in order to develop sustainable designs, increasing their lifetime and reducing the maintenance costs are crucial factors. Depending on the device to design, different methodologies may be followed in order to achieve these two goals while meeting the design requirements. One clear example can be found in the development of wind turbines. Their blades must be designed to withstand not only maximum loads and stresses but also the fatigue caused by the fluctuations around the load required to operate correctly. Reducing fatigue issues by limiting the amplitude of those fluctuations using passive or active control is a viable option to improve their lifetime. The aimof this dissertation is to contribute to the understanding of the underlying physics in biolocomotion. To this end, direct numerical simulations of different examples and problems at low Reynolds number, Re, have been performed using an existing fluid-structure interaction (FSI) solver. This FSI solver relies on the coupling of an incompressible-flow solver with robotic algorithms for the computation of the dynamics of a system of connected rigid bodies. The particularities of this solver are detailed in the thesis. The second part of the thesis includes the analysis of these examples and problems mentioned above.More in detail, the aerodynamic and aeroelastic behaviour of airfoils and wings at Re Æ 1000 in various conditions and environments has been analysed. Natural flyers and swimmers are immersed in turbulent and gusty environments which affect their aerodynamic behaviour. The first problem that has been studied is that of the unsteady response of airfoils impacted by vortical gusts. This first example focuses on how the impact of viscous vortices of different size and intensity on two-dimensional airfoils modify their response. Although in a simplified framework, this analysis allows to gather relevant information about the aerodynamic performance of the airfoils. This aerodynamic response is seen to be self-similar, and the work proposes a semi-empirical model to determine the temporal evolution of the lifting forces based on an integral definition of the vertical velocity induced by the gust, which can be known a priori. The target of the second problem is to analyse the load that can be mitigated in airfoils undergoing oscillations in the angle of attack using passive-pitching trailing edge flaps. This corresponds, for example, to a simplification of the problem of load mitigation in small-scale wind turbines. The use of passive-pitching trailing edge flaps is a strategy that has recently been recently proposed for large-scale wind turbines. Here, we investigate the validity of this strategy on a completely different scenario. Contrary to what happens in experiments at higher Reynolds numbers, whose results match the predictions of a quasi-steady linear model when the kinematics are within the range of applicability of this model, the load mitigation obtained in this work differs from the values of this theory. The load mitigated is larger or smaller than the predicted values depending on the amplitude of the oscillations in the angle of attack. However, the results of this work show that an increase in the length of the flap while the chord of the airfoil is kept constant leads to an equal change in the reduction of load, in line with the predictions of the quasi-steady model. The development of vortical structures is clearly affected by the flap when it is sufficiently large, which also involves changes in the dynamics of the flap and the forces seen by the airfoil. The repercussion that several of the variables defining the parametric space have on the aerodynamic behaviour of the foil and the dynamics of the flap are analysed. This allows to gather more information for an appropriate selection of those variables. Finally, the third and fourth problems involve the study of the effects of spanwise flexibility on both isolated wings and pairs of wings arranged in horizontal tandem undergoing flapping motions. The wings are considered to be rectangular flat plates, and the spanwise flexibility is modelled discretizing these flat plates in a finite number of rigid sub-bodies that are connected using torsional springs. The wings are considered to be rigid in the chordwise direction. Isolated spanwise-flexible wings find an optimal propulsive performance when a fluid-structural resonance occurs. At this flexibility, the time-averaged thrust is maximum and twice the value yielded by the rigid case, and the increment in efficiency is around a 15%. Flexibility and the generation of forces are coupled, such that the structural response modifies the development of the vortical structures generated by the motion of the wing, and vice versa. The optimal performance comes from a combination of larger effective angles of attack, properly timed with the pitching motion such that the projection of the forces is maximum, with a delayed development of the vortical structures. Besides, while aspect ratio effects are important for rigid wings, this effect becomes small when compared to flexibility effects when the wings become flexible enough. In fact, while the increase in thrust coefficient for rigid wings with aspect ratio 4 is 1.2 times larger than that provided by rigid wings with aspect ratio equal to 2, the value of this coefficient for resonant wings is twice the value yielded by rigid wings of aspect ratio 4. While forewings of the tandem systems are found to behave similarly to isolated wings, the aeroelastic response of the hindwings is substantially affected by the interaction with the vortices developed and shed by the forewings. This wake capture effect modifies the flexibility at which an optimal propulsive behaviour is obtained. This wake capture effect is analysed through an estimation of the effective angle of attack seen by both forewings and hindwings, linking the optimal behaviour with the maximisation of the effective angle of attack at the right instants. Based on the obtained results, a proof-of-concept study has been carried out analysing the aerodynamic performance of tandem systems made of wings with different flexibility, which suggests that the latter could outperformsystems of equally flexible wings.This thesis has been carried out in the Aerospace Engineering Department at Universidad Carlos III de Madrid. The financial support has been provided by the Universidad Carlos III de Madrid through a PIPF scholarship awarded on a competitive basis, and by the Spanish Ministry of Economy and Competitiveness through grant DPI2016-76151-C2-2-R (AEI/FEDER, UE).Programa de Doctorado en Mecánica de Fluidos por la Universidad Carlos III de Madrid; la Universidad de Jaén; la Universidad de Zaragoza; la Universidad Nacional de Educación a Distancia; la Universidad Politécnica de Madrid y la Universidad Rovira i VirgiliPresidente: José Ignacio Jiménez González.- Secretaria: Andrea Ianiro.- Vocal: Manuel Moriche Guerrer

Comparing galaxy populations in compact and loose groups of galaxies

Abstract.We compare the properties of galaxies in compact groups, loose groups, and the eld to deepen our understanding of the physical mechanisms acting upon galaxy evolution in dierent environments. This contribution is detailed in Coenda et al. (2012) and Martínez et al. (2013).Fil: Martínez, Héctor Julián Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Martínez, Héctor Julián Conicet. Instituto de Astronomía Teórica y Experimental; Argentina.Fil: Coenda, Valeria Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina.Fil:Coenda, Valeria Conicet. Instituto de Astronomía Teórica y Experimental; Argentina.Fil: Muriel, Hernán Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina.Fil: Muriel, Hernán Conicet. Instituto de Astronomía Teórica y Experimental; Argentina.http://adsabs.harvard.edu/abs/2014RMxAC..44...81MpublishedVersionAstronomía (incluye Astrofísica y Ciencias del Espacio

Reforma de vehicle de caire industrial en habitatge

L'objectiu del treball és la transformació d'una furgoneta de caire industrial per fer d'ella un habitatge funcional. Es pretén obtenir un espai còmode per permet realitzar viatges de més de tres dies fora de l'àmbit urbà i que sigui econòmicament viable. Durant el treball s'estudien tots els passos per realitzar la reforma del vehicle: Estudi aïllament; disseny de l'interior, prioritzant l'espai i el confort (realitzat amb SolidWorks); instal·lació d'estances; estudi d'instal·lació de gas, d'aigua i elèctrica; i tenir el coneixement de quines modificacions s'han de homologar perquè siguin legals.El objetivo del trabajo es la transformación de una furgoneta industrial para hacer de ella un vivienda funcional. Se pretende obtener un espacio cómodo para realizar viajes de más de tres días fuera de l'ámbito urbano i que sea económicamente viable. Durante el trabajo se estudian todos los pasos para realizar la reforma del vehículo: Estudio del aislamiento; diseño del interior, priorizando en el espacio i el confort (realizado con SolidWorks); instalación de estancias; estudio de la instalación de gas, de agua i electrica; y tener el conocimiento de que modificaciones se han de homologar para que sean legales.The purpose of this research paper is the study of the transformation of an industrial van to make out of it a functional home. The intention is to obtain a space comfortable to be able to go on long road trips of more than three days off grid, and to do it as cheap as possible. During the process, we will study all the steps necessary to transform the vehicle; study of the thermal insulation, interior design, space management and comfort (with SolidWorks); gas system management, water and electric systems; and the legal actions required to do the van build legal

Effects of environment on stellar metallicity profiles of late-type galaxies in the CALIFA survey

Aims. We explore the effects of environment in the evolution of late-type galaxies by studying the radial profiles of light- and massweighted metallicities of galaxies in two discrete environments: field and groups. Methods. We used a sample of 167 late-type galaxies with stellar masses of 9 ≤ log(M∗M·) ≤ 12 drawn from the Calar Alto Legacy Integral Field Area (CALIFA) survey. Firstly, we obtained light- and mass-weighted stellar metallicity profiles and stellar mass density profiles of these galaxies using publicly available data. We then classified them according to their environment into field and group galaxies. Finally, we studied the metallicity of galaxies in these two environments, including a comparison of the metallicity as a function of radius, at a characteristic scale, and as a function of stellar mass surface density. As metallicity depends on galaxy mass, we took special care throughout the study to compare, in all cases, subsamples of galaxies in groups and in the field that have similar masses. Results. We find significant differences between group and field late-type galaxies in terms of their metallicity: group galaxies are systematically higher in metallicity than their field counterparts. We find that field galaxies, in general, have metallicity profiles that show a negative gradient in their inner regions and a shallower profile at larger radii. This is in contrast to the metallicity profiles of galaxies in groups, which tend to be flat in the inner regions and to have a negative gradient in the outer parts. Regarding the metallicity at the characteristic radius of the luminosity profiles, we consistently find that it is higher for group galaxies irrespective of galaxy mass. At fixed local stellar surface mass density, group galaxies are again higher in metallicity, also the dependence of metallicity on surface density is less important for group galaxies. Conclusions. The evidence of a clear difference in metallicity between group and field galaxies as a function of mass, spatial scale, and local stellar mass density is indicative of the different evolutionary paths followed by galaxies in groups and in the field. We discuss some possible implications of the observed differences.Fil: Coenda, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Mast, Damian. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Muriel, Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Martínez, Héctor J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentin

Asistencia alimentaria y capacitación a población vulnerable, proyecto de inversión para el fortalecimiento y rediseño de un comedor comunitario en el sector Yomasa, localidad de Usme, Bogotá, Distrito Capital

MatrizEste proyecto se plantea como una alianza público – privada entre la Alcaldía Mayor de Bogotá, a través de la Secretaría Distrital de Integración Social (SDIS por sus siglas en español), y la Junta de Acción Comunal del Sector Yomasa, de la localidad de Usme, Distrito Capital, para fortalecer y rediseñar un comedor comunitario en dicho sector geográfico. Como es de conocimiento público en el Distrito Capital, los comedores comunitarios son espacios físicos y sociales en los que se propicia la inclusión social de personas, familias y poblaciones en condiciones de pobreza y vulnerabilidad social, se suministra alimentación servida y se realizan otras actividades de participación social y comunitaria. En consecuencia, el proyecto está articulado con las políticas públicas contempladas en el Plan de Desarrollo Económico y Social “Bogotá Humana”, vigencia 2012 – 2016. El fortalecimiento y rediseño del comedor, consiste en ofrecer a la población vulnerable del sector Yomasa, además de asistencia alimentaria, capacitación en varios aspectos: hábitos alimenticios, valores humanos, formación musical, formación vocacional y alfabetización en TICS (Tecnologías de la Información y la Comunicación), todo con el propósito de elevar su nivel nutricional y al mismo tiempo propiciar alternativas que generen mayores ingresos en las familias para mejorar su nivel económico y social y con ello elevar la calidad de vida de los beneficiarios. Bajo esta perspectiva, el proyecto se perfila como un aporte innovador en la gestión y funcionamiento de los comedores comunitarios promovidos y establecidos por el gobierno en Bogotá, Distrito Capital de Colombia. El diseño del proyecto utiliza la Metodología General Ajustada (MGA por sus siglas en español), en la medida en que su financiación pretende efectuar con recursos del sector público, para hacerlo operativo a través del Sistema General de Regalías. El costo total del proyecto es de $251’400.000 y su duración es de 5 meses, con posibilidades de ser replicado en las 19 restantes localidades del Distrito Capital.This project arises as a partnership public – private between Bogota’ Municipality and the Board of Community action in the sector of Yomasa, Bogotá, DC, Through, The District Secretary of Social Integration. The purpose of this project is to strengthen and to redesign a soup kitchen for the people in this place. As a public knowledge in Bogota, the soup kitchens are social places where the inclusion of individuals, families and populations in conditions of poverty and social vulnerability, is promoted. Moreover, in those soup kitchens are supplied food and activities of social and community participation. Thus, this project is articulated with the public policies of economic and social development by “Human Bogota”, 2012-2016 plans. The strengthen and redesign of the soup kitchen, is to provide to the vulnerable population in Yomasa, in addition to food assistance, education in various aspects: eating habits, human values, musical education, vocational education and knowledge in ICT (Information and Communications Technology), in order to evaluate their nutritional status and, at the same time, to promote alternatives to generate higher incomes and improve their economic and social status; and with this, improve the quality of life of the beneficiaries. In this perspective, this project rises as an innovative contribution in the management and operation of the soup kitchens established by the Bogota’ Municipality. The project design uses the Methodology General Adjusted (MGA in Spanish), for this reason, the funding is intended with public resources, to make it operational through the General system of royalties. The total cost of this project is 251400000 COP and its duration is five months, with possibility of be replicated in nineteen towns of Bogota

Avances en la inclusión de intereses y necesidades de mujeres rurales en políticas públicas agropecuarias y de cambio climático: el caso de Colombia

La agricultura en Colombia es considerada una de las principales actividades económicas. De los 48 millones de habitantes que tiene el país, 24% vive en áreas rurales y 3,4 millones de ellos están activamente empleados en la producción agrícola primaria. De estos, 75% son hombres y 25% son mujeres4. Ahora bien, el 80% de las tierras en Colombia está en manos del 14% de los propietarios. Según cifras del Instituto Geográfico Agustín Codazzi, la concentración de la tierra en el país en términos del Gini de tierras es de 0,84 para el año 20096. A esta evidente desigualdad en la concentración de la propiedad de la tierra se le suma que dicha propiedad tiende a ser informal. Así mismo, con unas condiciones muy particulares de despojo y reconfiguración de tierras y territorios en el marco de un conflicto armado de más de sesenta años, de una constante lucha por la explotación legal e ilegal de los recursos naturales y de la falta de un sistema de información actualizado de catastro. El género se refiere a roles, responsabilidades, derechos, relaciones e identidades de hombres y mujeres que se definen o atribuyen dentro de una sociedad8. Para efectos de este documento, se hará referencia a las relaciones de género en contextos rurales productivos, es decir, cómo se relacionan mujeres y hombres en el hogar, en la producción agropecuaria, en el acceso y administración de los recursos y en los procesos de toma de decisión en un contexto dado, con el fin de comprender necesidades e intereses de mujeres y hombres y la importancia de que éstos se tomen en cuenta en políticas públicas agropecuarias y de cambio climático

Fluid-structure resonance in spanwise-flexible flapping wings

We report direct numerical simulations of the flow around a spanwise-flexible wing in forward flight. The simulations were performed at Re = 1000 for wings of aspect ratio 2 and 4 undergoing a heaving and pitching motion at Strouhal number Stc ≈ 0.5. We have varied the effective stiffness of the wing Π1 while keeping the effective inertia constant, Π0 = 0.1. It has been found that there is an optimal aerodynamic performance of the wing linked to a damped resonance phenomenon, that occurs when the imposed frequency of oscillation approaches the first natural frequency of the structure in the fluid, ωn,f /ω ≈ 1. In that situation, the time-averaged thrust is maximum, increasing by factor 2 with respect to the rigid case with an increase in propulsive efficiency of approximately 15 %. This enhanced aerodynamic performance results from the combination of larger effective angles of attack of the outboard wing sections and a delayed development of the leading-edge vortex. With increasing flexibility beyond the resonant frequency, the aerodynamic performance drops significantly, in terms of both thrust production and propulsive efficiency. The cause of this drop lies in the increasing phase lag between the deflection of the wing and the heaving/pitching motion, which results in weaker leading-edge vortices, negative effective angles of attack in the outboard sections of the wing, and drag generation in the first half of the stroke. Our results also show that flexible wings with the same ωn,f /ω but different aspect ratio have the same aerodynamic performance, emphasizing the importance of the structural properties of the wing for its aerodynamic performance.Funding. This work was partially supported by grant DPI2016-76151-C2-2-R (AEI/FEDER, UE).Publicad