Effect of Vinyl Flooring on the Modal Properties of a Steel Footbridge

Damping ratios associated with non structural elements play an important role in mitigating the pedestrian-induced vibrations of slender footbridges. In particular, this paper analyses the effect of vinyl flooring on the modal parameters of steel footbridges. Motivated by the unexpected high experimental damping ratios of the first vibration modes of a real footbridge, whose deck was covered by a vinyl flooring, this paper aims at assessing more accurately the experimental damping ratios generated by this non-structural element on steel footbridges. For this purpose, a laboratory footbridge was built and vinyl flooring was installed on it. Its numerical and experimental modal parameters without and with the vinyl flooring were determined. The operational modal analysis method was used to estimate experimentally the modal parameters of the structure. The damping ratios associated with the vinyl flooring were obtained via the substraction between the experimental damping ratios of the laboratory footbridge with and without the vinyl flooring. An average increase of the damping ratios of 2.069% was observed due to the vinyl flooring installed. According to this result, this type of pavement may be a useful tool to significantly increase the damping ratios of steel footbridges in order to reduce pedestrian-induced vibrationsMinisterio de Economía y Competitividad DPI2014-53947-RFondo Europeo de Desarrollo Regional DPI2014-53947-

Critical analysis of the European Union directive which regulates the use of biofuels: An approach to the Spanish case

In recent times, the global debate on the environment has been centered on CO2 emissions. This gas is the major cause of the “greenhouse effect” and people are more concerned with the idea that the emissions of this gas should be minimized. As a result of this concern, the Kyoto Protocol was enacted and subscribed to by many countries, setting the maximum gas emissions for them. Fossil fuels are a major source of CO2 emissions. For some years now The European Union has been seeking to promote some years now the use of biofuels as substitutes for diesel or petrol for transport purposes. As a result of this policy, in 2003 the European Union (EU) Directive 2003/30/EC [1] was developed with the aim of promoting the use of biofuels as a substitute for diesel or gasoline among European Union countries as well as to contribute to fulfilling the commitments acquired on climate change, security of supply in environmentally friendly conditions and the promotion of renewable energy sources. In order to achieve these goals, the directive forces all EU members to ensure that before December 31 of 2010 at least 5.75% of all gasoline and diesel fuels sold for transport purposes are biofuels. European Union countries have social and economic characteristics unique to themselves. The energy dependence on foreign sources, the features of the agricultural sector or the degree of industrialization varies greatly from one country to another. In this context, it is questionable whether the obligation imposed by this directive is actually achieving in its application uniform and/or identical goals in each of the countries involved and whether the actions of the various governments are also aligned with these goals. All these ideas were developed in a previous report (Sobrino and Monroy (2009) [2]). This report examines the possibility of using hydrogen as an alternative to fossil fuels and biofuels from a technical, economic and environmental point of view in the specific case of a European Union country: Spain

Biofuels in Spain: Market penetration analysis and competitiveness in the automotive fuel market

For several years the European Union (E.U.) has been promoting the use of biofuels due to their potential benefits such as the reduction of dependence on foreign energy imports (the raw materials can be produced within the E.U.), the more stable fossil fuel prices (they can replace fossil fuels on the market), the greenhouse gas (GHG) reduction (biofuels’ raw materials fix CO2 from the atmosphere) and the fact that they can represent an additional source of income for the primary sector (biofuels’ raw materials are vegetables that can be grown and harvested). Despite the public aids (direct and indirect), biofuels are not competitive with fossil fuels at present, but it is possible that in the future the environment conditions change and biofuels might become competitive. It is difficult to assess whether this will happen or not, but it is possible to make an assessment of a future situation. This article presents two analyses with one objective: to determine if biofuels might become competitive in the future. The first analysis examines the dependencies of two quotations which have a strong relationship with fuels: the crude oil quotation and the CO2 bond quotation. The analysis of these relationships may help to forecast the future competitiveness of biofuels. For instance, biofuels’ future competitiveness will be higher if their raw material costs are not related to crude oil quotations or if they are related in a negative way (the higher the crude oil quotations the lower the raw material biofuels’ cost). The second analysis focuses on the market penetration of biofuels in the Spanish market. There are data related to biofuels monthly consumption in Spain since 2007 and it is possible to know if biofuels are gaining market quota since the

La migración de los padres: Un desafío en el sector educativo de Santa Rosa de Cabal

El objetivo del trabajo de investigación es analizar la incidencia que genera la migración a nivel interna y/o internacional de los padres en el rendimiento académico y desempeño disciplinario de sus hijos en tres Instituciones Educativas de Santa Rosa de Cabal. Inicialmente se hace un diagnóstico para conocer la movilidad de los padres, posteriormente se recogen los datos a través de una encuesta aplicada a los educandos de los grados séptimo, octavo y noveno. A partir de la información obtenida se construye la base de datos para el análisis estadístico mediante el programa SPSS estableciendo cruces con otras categorías relacionadas con el tema migratorio (remesas, comunicación, con quién viven los estudiantes). A nivel académico se encontró que la población que obtuvo el menor número de materias perdidas es la que cuenta con padres migrantes internacionales y en el año 2013 presentaron los mejores promedios, pero en el año 2014 bajaron los promedios y es el grupo que registró menos acompañamiento en la elaboración de las tareas. Con referencia al desempeño disciplinario se comprobó que el hecho migratorio de los padres es un factor que influye en los estudiantes. Con estos resultados se ve la necesidad que las Instituciones Educativas conozcan, apoyen e implementen acciones que beneficien a los estudiantes hijos de migrantes

Public libraries engaging communities through technology and innovation : Insights from the Library Living Lab

Public libraries have proven for centuries to be infrastructures both stable enough as reference centers for access to knowledge yet plastic enough to respond to the social changes of the communities they serve. In these present times of transformation, during which digitalization and the intensive use of technologies are modifying the way in which knowledge is produced, public libraries are facing new and disruptive challenges. The emergence of certain innovation ecosystems within libraries, which place the community at the center of cocreation and codesign processes between different agents, has transformed some public libraries into encountering spaces. The Library Living Lab, in the Miquel Batllori Public Library of Sant Cugat del Vallès (Barcelona, Spain), is an expression of this systemic change. The following paper is a case study based on that sociotechnical infrastructure and analyzes, through two singular examples, how digital technologies can be drivers of social transformation when citizen engagement is placed at the center of innovation processes. The case study also provides insights into how public libraries may become key agents in fostering and strengthening social cohesion through situated, collective, and technology-based innovation practice

Análisis de los contenidos de historia en el ámbito educativo

En nuestro trabajo "Análisis de los contenidos de Historia en el ámbito educativo´´ hemos querido investigar la importancia de la asignatura dentro de la Educación Primaria y analizar los contenidos que la conforman. Dentro de la investigación hemos entrevistado a alumnos, docentes y futuros docentes para conocer su opinión sobre la misma, qué esperan de la asignatura y cuál creen que es la metodología correcta para impartirla y que sea motivante para ambos agentes educativos, también hemos analizado el papel que ha jugado la asignatura a lo largo de la historia de la educación en España y el papel que juega actualmente según los documentos oficiales, se podrá encontrar también análisis del material usado actualmente para impartir las clases, siendo estos libros de texto ya que es el material que usan los docentes que han sido entrevistados como base para sus sesiones, por ultimo podrán encontrar una propuesta didáctica que creemos motivante para los alumnos y con la que pueden aprender los contenidos que se exigen de una manera más interactiva y jugando ellos y ellas el papel protagonista en las clases.In our work "Analysis of the contents of History in the educational field '' we wanted to investigate the importance of the subject in Primary Education and analyze the contents that comprise it. Within the research we interviewed students, teachers and future teachers to know their opinion about it, what they expect from the subject and what they believe is the correct methodology to teach and that is motivating for both educational agents, we have also analyzed the role who has played the subject throughout the history of education in Spain and the role that currently plays according to official documents, you can also find analysis of the material currently used to teach the classes, these textbooks being that it is the material used by the teachers who have been interviewed as a basis for their sessions, finally they can find a didactic proposal that we believe motivating for the students and with which they can learn the contents that are required in a more interactive way and playing them and they protagonist role in the classes and playing, they will be the real protagonist in their classes.Universidad de Sevilla. Grado en Educación Primari

Self-control of a lively footbridge under pedestrian flow

Congreso celebrado en la Escuela de Arquitectura de la Universidad de Sevilla desde el 24 hasta el 26 de junio de 2015.In this paper, a case study about a lively footbridge is developed; the vibration levels caused by the pedestrian action are controlled by the change of the modal parameters of the structure due to the pedestrian-structure interaction. A detailed finite element model of the structure has been updated from an operational modal analysis. The updated model has been used to obtain the numerical acceleration at the mid-span of the footbridge under different pedestrian flows. A relation between the maximum acceleration and the pedestrian density on the deck has been obtained numerically, pointing out an improvement in the comfort level of the structure when the number of pedestrians increases. This result validates a design rule for cable-stayed footbridges in order to avoid vibratory problems, since the first vertical natural frequency of the structure remains below the range that characterizes the pedestrian walking action

Tipología de incendios en función de su respuesta vegetal: análisis mediante índices espectrales y datos de campo.

El incremento del número de los incendios en el ámbito mediterráneo ha hecho que este tema se postule como uno de los principales problemas medioambientales. Para su estudio, es imprescindible conocer el comportamiento de la vegetación en su proceso de regeneración vegetal. En el siguiente trabajo se analizan de forma uni-temporal 15 incendios de la comunidad de Aragón, en las provincias de Zaragoza y Huesca. Esta selección consta de incendios de diferentes tamaños, tipo de vegetación, época, año de origen, así como de diferente sustrato. Para realizar el análisis de la regeneración vegetal se han utilizado imágenes satélites a dos resoluciones espaciales 10m (R10) y 20m (R20) capturadas por Sentinel-2, de tal forma que permite averiguar el potencial del sensor MSI con un nivel de procesamiento Level2-A. Es decir, incluye la corrección atmosférica mediante el algoritmo SEN2COR. Una vez descargadas las imágenes se ha realizado un análisis estadístico mediante NDVI (Normalized Difference Vegetation Index) y ANOVA (ANalysis Of VAriance). Por otra parte, se han establecido agrupaciones entre los incendios atendiendo a sus diferencias y similitudes con el método de Bonferroni. Los resultados se han comparado con datos de campo para esclarecer qué tipo de vegetación regenta actualmente en las áreas quemadas. Finalmente, se ha efectuado un análisis de las agrupaciones en función de las características de los pixeles de cada uno de los incendios. A continuación, se han establecido dos tipos de agrupaciones, no jerárquicas (K-means) y jerárquicas (Clasificación Tree), permitiendo analizar los resultados obtenidos de los indicies de vegetación NDVI y NBR, así como su correcto empleo. Con lo citado anteriormente, se han conseguido asociar los patrones de regeneración específicos en función de las características del fuego<br /

Desarrollo de una forma de onda GFDM con radio definida por software

In this paper the performance of a Generalized Frequency Division Multiplexing waveform is evaluated when compared to an Orthogonal Frequency Division Multiplexing signal. For the development of the previous waveforms, the GNU radio software and the Software Defined Radio (SDR) equipment USRP N210 are used. Through a spectrum analyzer the power of both waveforms are measured and the Out-of-Band Radiation is analyzed. Then, the results obtained are compared and the advantages and disadvantages of the implementation of GFDM as a waveform within the fifth generation systems are exposed.En este documento se evalúa el desempeño de una forma de onda GFDM (Generalized Frequency Division Multiplexing) que es comparada con una señal OFDM (Orthogonal Frequency Division Multiplexing). Para el desarrollo de las anteriores formas de onda se utilizan el software GNU radio y los equipos de Radio Definida por Software (SDR) USRP N210. Mediante un analizador de espectros se mide la potencia de ambas formas de onda y se analiza la Radiación Fuera de Banda (OOB). Luego, se comparan los resultados obtenidos y se exponen las ventajas e inconvenientes de la implementación de GFDM como forma de onda dentro de los sistemas de quinta generación