Randall-Sundrum brane cosmology: modification of late-time cosmic dynamics by exotic matter

In this paper we show, through the study of concrete examples, that, depending on the cosmic dynamics of the energy density of matter degrees of freedom living in the brane, Randall-Sundrum (RS) brane effects can be important not only at short distances (UV regime), but also at large cosmological scales (IR regime). Our first example relies on the study, by means of the dynamical systems tools, of a toy model based in a non-linear electrodynamics (NLED) Lagrangian. Then we show that other, less elaborated models, such as the inclusion of a scalar phantom field, and of a tachyon phantom field -- trapped in the brane -- produce similar results. The form of the RS correction seems to convert what would have been future attractors in general relativity into saddle points. The above "mixing of scales" effect is distinctive only of theories that modify the right-hand-side (matter part) of the Friedmann equation, so that, for instance, DGP-brane models do not show this feature.Comment: Latex, 12 pages, 9 eps figures. Title changed, discussion improved. Version that matches the one published in CQ

Teleological structure of scientific and mathematical education

One of the main educational objectives in the current Spanish curricula is to develop mathematical and scientific competences, understood as the set of skills and abilities needed to apply Mathematics and Science in situations where are required. This is therefore closely related, on one hand, to the functionality of the knowledge, in the sense of its usefulness in problem solving and in mathematical and science modeling problems. And, on the other hand, is related to the understanding of disciplinary knowledge, a cognitive phenomenon that enables and gives competence to the individual to elaborate contextualized and accurate answers. These answers involve the use of mathematical and scientific knowledge in some of the categories of their phenomenological and epistemological dimensions. For this reason, in this work we carry out a theoretical and reflexive analysis that tries to determine which aspects of the Mathematics and Science Education should be promoted in order to optimize the formative dimension of an individual in these disciplines. This dimension, frequently forgotten in learning and teaching processes, turns out to be, in conjunction with the functional and instrumental dimensions, necessary to acquire the appropriate knowledge in Mathematics and Science that will enable future citizens to permanently adapt to the environment and eventually transform it positively. The results of the analysis show the components of this dimension that should be prioritized in the Science and Mathematics Education: the intellectual autonomy, understood as the ability to think for ourselves and to put in use our abilities and skills to generate information to solve real life problems and to make the right decisions; the moral autonomy, defined as the capacity to face with real life problems with ethical implications; and the social autonomy, understood as the aptitude to make decisions using social abilities and skills.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.“Criterios e instrumentos de evaluación de unidades de enseñanza y aprendizaje” (PPIT.UMA.B1.2017/16) financiado por la Universidad de Málaga en la convocatoria de 2017-2018

Key aspects in 3D fatigue crack closure numerical modelling

Since long time, fatigue crack closure has been studied by means of finite element models. Initially by bi-dimensional models and recently, due to the higher computational capabilities, the use of three-dimensional models has been extended, providing a wider comprehension of the problem. Starting with the methodology used for 2D cases, a specific methodology for 3D models has been developed. Key parameters affecting the model have been analyzed and recommendations have been established. The numerical accuracy is evaluated in terms of crack closure and opening values. They main issues studied are the material behaviour, the loading cycles and crack growth scheme, the contact simulation, the meshing and the element size at the crack tip and along the thickness, the plastic wake computed and the opening and closure definition considered. This paper summarises the main learning and recommendations from the latest numerical modelling experience of the authors.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Study of the Mercury M6e RFID reader for Ultra High Frequency band and testing operations

Pg. 6 Report 1 Introduction 1.1 Abstract In order to sum up the whole work done here, we must begin explaining with a fast overview of the contents that are going to appear below. At the beginning of the semester, the UPC bought the M6e RFID for UHF reader from mercury in the interest of make some research at experimental level and stating constancy of the knowhow of the equipment operation. This project defines not only the operation but also the scope and design of that knew tool, very useful in a few years but not commonly implemented nowadays. Another target of this research is to know how far can we arrive modifying some parameters from the equipment or try to implement new ones in order to optimize their functions to the maximum. Aside from those intentions, the idea of creating some kind of Python language wrappers (bindings) in order to call functions from the library written in C of the mercury API has been raised. The final purpose is to take control of the RFID system through a Python program by calling C functions in the vendor provided library. The reason why this study is being carried out is with the aspirations of implementing this system in a range of different possible applications. A personal aspiration is to take it to robotics applications such as mapping localization of the land and also finder stuff radar, as an example. It can be taken too for the supermarket cashier, thing that would make the job in a faster and easier way than current existing barcodes. The methods used here are basically two: in one hand, we must name the experimental work at the IOC’s Laboratory with the physical equipment which gets along with a software (Universal Reader Assistant) and in the other hand, with the help of two programming languages such as Python and C for the achievement of creating the bindings

Feasibility analysis and simulation of a renewable energy system in Barcelona

In order to sum up the whole work done here, it should be explained with a fast overview, the contents that are going to appear below. The main purpose of this project is to reduce Barcelona’s dependency of fossil fuels trough the installation and analysis of a renewable energy model developed at the Incheon National University Campus (EPSE Lab) that would fit the city according with its resources. The Renewable Energy Sources are going to be mainly solar and wind energy, quantifying the energy productions with a simulation software named SAM Energy which will show the performance depending on several key energy parameters. With its results, is calculated the energy production capabilities as well as the economical savingsOutgoin

Función docente y gestión educativa del 8vo grado “a” del Instituto Nacional las Mercedes, comunidad las mangas, Municipio san Isidro, Departamento Matagalpa, en el II semestre 2015.

Este estudio se trata sobre la Función Docente y Gestión Educativa del 8vo grado “A” del Instituto Nacional Las Mercedes, comunidad Las Mangas, municipio San Isidro, departamento Matagalpa, en el II semestre 2015. El propósito de este trabajo investigativo fue, Valorar la función docente y gestión educativa en el 8vo grado Instituto Nacional las Mercedes, comunidad las Mangas, Municipio San Isidro, departamento Matagalpa en el segundo semestre 2015. Este trabajo aborda la importancia que tiene la función docente y la gestión educativa para el buen desempeño en el ámbito educativo. Se exponen las razones por las que un profesor no debe de limitarse a cumplir con ciertos requisitos que le impone el sistema educativo, ya que su desempeño implica formar al ser humano que requiere de una atención especial. Este trabajo beneficia tanto a docente en sus capacidades como a los estudiantes en su nivel de aprendizaje. Ante todo lo expuesto anteriormente se llegó a las siguientes conclusiones. Se logró identificar que la función docente en el 8vo grado en Instituto Nacional Las Mercedes, no todo los docentes cumplen a cabalidad la función que les corresponde. En cuanto a la ética, lo social a lo creativo y a la comunicación. La gestión educativa no ha sido tan eficiente en cuanto a aplicación de proyectos sociales (educativo), porque no ha habido apoyo por parte de las demás instituciones, ya que el instituto no cuenta con buen fondo monetario, además la directora tiene poca interacción con los docentes. Palabras claves: Función docente, Gestión educativ

De los technopaegnia carolingios a la clerecía rabínica medieval. Nuevos horizontes en la literatura medieval a la luz de la poesía comparada

The concept of «mester de clerecía» is exposed here as a broad phenomenon whose origins are in Medieval non-quantitative latin poetry, in which, after the lost of the vowels quantity, the number of syllables is determining. This work will analyze two texts from a comparative point of view: a latin poem composed in tetrastichs of pentadecasyllables during the carolingian period, attributed to Paulin of aquilea, which reflects the initial status of medieval narrative poetry «a sílabas contadas»; and a castilian poem composed in the 13th century in «cuaderna vía» written by a Jewish author: the Coplas de Yosef. Both have a common source: the story of Joseph narrated in the book of Genesis. However, the literary procedures used by both authors, as well as the final results are very different. The contrastive analysis of the two texts make us determine the ideology present in each of them and also make us pose key questions related to the concept of «mester de clerecía», its definition, limits and evolution.El concepto de «mester de clerecía» se plantea aquí como un fenómeno amplio que se inicia en la poesía mediolatina no cuantitativa, en la que el cómputo silábico se convierte en un factor determinante tras la pérdida de la cantidad de las sílabas. En este trabajo analizaremos dos textos de forma comparativa: un poema latino compuesto en el período carolingio en cuartetas pentadecasilábicas y atribuido a Paulino de aquilea, que refleja ese estadio inicial de la poesía narrativa medieval «a sílabas contadas», y un poema castellano del siglo XIII en cuaderna vía escrito por un autor judío: las Coplas de Yosef. ambos textos tienen como base el mismo tema: el relato de José narrado en el Génesis, sin embargo, la formulación del mismo, así como el resultado final son muy diferentes. El análisis contrastivo de estos poemas nos lleva a determinar la ideología que subyace a cada uno de ellos, así como a plantear cuestiones claves en relación al concepto de mester de clerecía, su definición, límites y evolución

Asymptotic Properties of a Supposedly Regular (Dirac-Born-Infeld) Modification of General Relativity

We apply the dynamical systems tools to study the asymptotic properties of a cosmological model based on a non-linear modification of General Relativity in which the standard Einstein-Hilbert action is replaced by one of Dirac-Born-Infeld type. It is shown that the dynamics of this model is extremely rich: there are found equilibrium points in the phase space that can be associated with matter-dominated, matter-curvature scaling, de Sitter, and even phantom-like solutions. Depending on the value of the overall parameters the dynamics in phase space can show multi-attractor structure into the future (multiple future attractors may co-exist). This is a consequence of bifurcations in control parameter space, showing strong dependence of the model's dynamical properties on the free parameters. Contrary to what is expected from non-linear modifications of general relativity of this kind, removal of the initial spacetime singularity is not a generic feature of the corresponding cosmological model. Instead, the starting point of the cosmic dynamics -- the past attractor in the phase space -- is a state of infinitely large value of the Hubble rate squared, usually associated with the big bang singularity.Comment: 12 pages, Revtex, 12 eps figures. Several new references added. Minor changes in the main text. Discussion improve