215 research outputs found

    Sistemas ópticos avanzados para iluminación natural en entornos arquitectónicos

    Get PDF
    La iluminación natural debe ser considerada como la forma más ecológica para iluminar cualquier espacio y una de las oportunidades y desafíos de diseño más importantes de la arquitectura. La vida humana está fuertemente influida por la luz natural y hoy en día tenemos que añadir a este factor la importancia de la conservación de la energía y la reducción de la contaminación. Por lo tanto, el guiado de la luz es un reto importante para la industria. Las guías de luz prismáticas huecas (HPLGs) ofrecen alternativas técnicas óptimas como herramienta de transporte de la luz, ya que pueden llevar la luz natural y artificial a través del interior de los edificios de manera eficiente. En esta tesis, se proponen varios desarrollos relacionados con la iluminación mediante guías de luz huecas que incluyen estudios teóricos y experimentales, el desarrollo de modelos matemáticos que predicen el comportamiento de la luz en guías prismáticas y un método analítico para cuantificar la influencia de la deformación del principal elemento óptico que las compone y es la lámina prismática. Esta investigación facilita la predicción del flujo transportado, permitiendo optimizar su funcionamiento mejorando la eficiencia en sus aplicaciones. Entre los diseños propuestos se presenta un sistema óptico de guiado de luz de grandes dimensiones aplicado a la edificiación que permite una extracción de luz de manera controlada permitiendo equilibrar el flujo en los distintos espacios de manera eficiente en un edificio de oficinas para un amplio rango de posiciones solares. También se presenta un sistema óptico basado en óptica anidólica para trasnferir el flujo luminoso en los giros delas guías huecas incrementando la eficiencia respecto del diseño estándar. La reproducción del color y las características colorimétricas en el guiado de la luz, son parámetros importantes a tener en cuenta dada la necesidad de obtener una elevada calidad de iluminación en construcciones como edificios de oficinas, centros de producción o museos y también con el objeto de conseguir las aprobaciones pertinentes en relación a la normativa vigente. Con objeto de evaluar la diferencia de calidad cromática que proporcionan las guías de luz huecas se realizan comparativas entre guías huecas prismáticas y de aluminio de diversas geometrías, obteniéndose mejoras en la capacidad de reproducción cromática de la luz a través de la guía prismática. El incremento de las guías de luz huecas instaladas en las últimas décadas, y las recientes innovaciones de los materiales que las componen, hacen necesario el desarrollo de métodos predictivos para cuantificar su eficiencia. A pesar de que los procesos de fabricación actuales hacen posible el desarrollo de unas láminas prismáticas de excelente calidad óptica, es importante analizar los fallos que limitan su comportamiento como sistema de guiado óptico. El desarrollo de un modelo matemático multiparamétricos permite determinar la eficiencia de unas guías de luz prismáticas cuantificando el impacto que tienen las imperfecciones d ela lámina prismática en la eficiencia del guiado de luz. El ajuste del modelo se realiza mediante procedimientos de optimización basado en los datos de flujo objetivods en simulaciones con software de trazado de rayos y comprobaciones de la eficiencia en la transmitancia mediante un modelo experimental. Este modelo muestra cómo los defectos en los vértices de la lámina prismática debidos a limitaciones en la fabricación son considerados como la principal fuente de pérdidas. Por último se proporciona un método de caracterización de la deformación que es producida en una lámina prismática por cambios en la curvatura a través de algoritmos de procesamiento de imagen. Este método muestra la relación entre la curvatura de la lámina, la deformación y el flujo luminoso transmitido en diversos ángulos de incidencia de la luz. En estos estudios, se ha evaluado la eficiencia y la calidad de luz en el guiado a través de guías huecas y se han propuesto modelso experimentales y teóricos para objeter mejoras en los desarrollos

    Mathematical Model Applied To Improve The Natural Lighting Design

    Get PDF
    Daylighting must be considered as the greenest way to illuminate any space and one of the most important architectural design challenges and opportunities. Human life is strongly influenced by natural lighting, and nowadays we have to add to this factor the importance of energy conservation and pollution reduction objectives. The development of hollow light guides offers people the advantages of natural lighting and the benefits of reduced energy consumption systems, providing changes in architectural form of spaces where sunlight does not have direct access. Hollow Cylindrical Prismatic Light Guides (CPLGs) are transparent optical components able to transmit high diameter light beams in daylight buildings applications without relevant losses. The goal of this paper is to show a novel lighting design based on hollow prismatic light pipes, which let daylight to be introduced inside of buildings. An improved mathematical modelling to predict light transmission efficiency based on realistic software simulations and experimental models is presented

    The Engagement of the Social Networks in the ACB Basketball League

    Get PDF
    We currently live in a technological age, and in continuous growth. Within this age, social networks have emerged as a way of communicating and creating value in branding. Sports clubs have adapted their way of communicating with their fans and have made social networks an indispensable tool for their daily communication. The aim of the present study is to analyze how the position in the ranking affects the engagement of the social networks of 18 basketball clubs that make up the Endesa ACB League during match days 16 to 34. Specific formulas were used in study to analyze social networks of Facebook, Twitter, Instagram, and YouTube. The results show great variability of engagement results as well as a positive correlation between the ranking in the table and engagement on the different social networks, with Instagram having the highest correlation of all the social networks.Iundenia, Centro de Formacion de Tecnicos Deportivos CIF B-18905760 18013708startup Football Connection (FOOC) 4.073.37

    Ejercicio físico basado en descansos activos sobre la función cognitiva y la competencia matemática en estudiantes universitarios de grado

    Get PDF
    A review of the literature has demonstrated the impact of active breaks (AB) on students’ cognition and academic performance. Despite the evidence, undergraduate students seem to remain passive during the lessons as the teaching is mostly traditional and revolves around the teacher. To break with this tendency in the university context, we included physical activity (PA) breaks during lessons. This study aimed to observe the acute effect of AB on the students’ attention and mathematical competence. A total of 25 undergraduate students (Mage = 23.36, SD = 1.98) participated in this study and performed an intervention under two conditions: i) control condition and ii) active-break condition. Results revealed that after receiving an AB (15 minutes) of moderate intensity students’ attention was improved. More specifically, participants were faster at D2 and their math tasks results improved.La literatura ha demostrado el impacto de los descansos activos (AB; active breaks en inglés) en la cognición y el rendimiento académico de los estudiantes. A pesar de la evidencia, los estudiantes universitarios parecen permanecer pasivos durante las lecciones, ya que la enseñanza es mayoritariamente tradicional y gira en torno al profesor. Para romper con esta tendencia en el contexto universitario, incluimos pausas de actividad física (AF) durante las clases. Este estudio de casos cruzados tiene como objetivo observar el efecto agudo de los descansos activos en la atención y la competencia matemática de los estudiantes. Un total de 25 estudiantes de grado (Medad = 23,36, DE = 1,98) participaron en este estudio y realizaron una intervención bajo dos condiciones: i) condición de control y ii) condición de descansos activos. Los resultados muestran que los estudiantes mejoraron su atención después de recibir una sesión de descanso activo (15 minutos) de intensidad moderada. En este sentido, los participantes fueron más rápidos en D2 y mejoraron sus resultados en la tarea de matemáticas

    Evolutionary optimization algorithms for nonimaging optical design

    Get PDF
    Evolutionary optimization algorithms have been recently introduced as nonimaging optics design techniques. Unlike optimization of imaging systems, non sequential ray tracing simulations and complex non centred systems design must be considered, adding complexity to the problem. The Merit Function (MF) is a key element in the automatic optimization algorithm, nevertheless the selection of each objective's weight, {wi}, inside merit function needs a previous trial and error process for each optimization. The problem then is to determine appropriate weights value for each objective. In this paper we propose a new Dynamic Merit Function, DMF, with variable weight factors {wi(n)}. The proposed algorithm, automatically adapts weight factors, during the evolution of the optimization process. This dynamic merit function avoids the previous trial and error procedure selecting the right merit function and provides better results than conventional merit functions (CMF). Also we analyse the Multistart optimization algorithm applied in the flowline nonimaging design technique

    Efficient and sustainable energy lighting solutions

    Get PDF
    The electric lighting is responsible for 15% of the electricity consumption, the efficiency in this sector has a good progress in recent years, it can still improve more. Conventional energy sources are polluting and limited, so it is essential to use less aggressive energies with the environment. In lighting, this premise is being implemented in a cross-cutting manner, but in response to varied and sometimes contradictory interests. The development of lighting devices based on solar radiation is an inalienable objective, as is the use of artificial lighting sources that are clean with the environment. To achieve these two objectives, it is essential to know and study the design techniques of non-image optics. In the present work we present new systems design techniques and lighting elements: ray tracing optimization technique, light vector field technique. As well as its implementation and application in various areas of lighting: lighting in office buildings, libraries museums. We show that renewable energy strategy in the field of lighting not only produce energy save, also produce good effects in other aspects of human life like well-being, productivity and heritage conservation

    Epigenetic Mechanisms in Hirschsprung Disease

    Get PDF
    Hirschsprung disease (HSCR, OMIM 142623) is due to a failure of enteric precursor cells derived from neural crest (EPCs) to proliferate, migrate, survive or differentiate during Enteric Nervous System (ENS) formation. This is a complex process which requires a strict regulation that results in an ENS specific gene expression pattern. Alterations at this level lead to the onset of neurocristopathies such as HSCR. Gene expression is regulated by different mechanisms, such as DNA modifications (at the epigenetic level), transcriptional mechanisms (transcription factors, silencers, enhancers and repressors), postranscriptional mechanisms (30UTR and ncRNA) and regulation of translation. All these mechanisms are finally implicated in cell signaling to determine the migration, proliferation, differentiation and survival processes for correct ENS development. In this review, we have performed an overview on the role of epigenetic mechanisms at transcriptional and posttranscriptional levels on these cellular events in neural crest cells (NCCs), ENS development, as well as in HSCR.Instituto de Salud Carlos III (ISCIII) PI16/01422Spanish Ministry of Economy and competitiveness PI16/01422European Union PI16/0142

    Recovery of the physiological status in professional basketball players using NESA neuromodulation treatment during different types of microcycles in season: A preliminary randomized clinical trial.

    Get PDF
    The purpose of the study was to describe and compare recovery status after official basketball competition in players who underwent NESA neuromodulation treatment (NNT) in weeks with one or two matches. The recovery parameters of 12 professional male basketball players (mean ± SD, age: 20.6 ± 2.7 yr; height: 197.8 ± 11.7 cm; and body mass: 89.0 ± 21.2 kg) that competed in the LEB Plata (Spanish third division) were monitored 2 days after match-play over 6 weeks, and included: 1) the Hooper Test, which combines four subjective variables (sleep, stress, fatigue and soreness); 2) common biochemical markers (e.g., testosterone, cortisol and ratio T:C); and 3) lowest heart rate [HR], average HR, HR variability, sleep duration, awake time during night and onset latency before asleep). Players that completed NNT presented differences compared to the control group in sleep data. For instance, the lowest HR (p < 0.001), average HR (p < 0.001) and total awake time (p = 0.04) were significantly reduced in the NNT group. On the contrary, the control group presented greater values than the NNT group in the subjective Hooper Test, although only stress presented significant differences (Control 2.5 ± 1.2 vs. NNT cost or 3.2 ± 0.9; p = 0.01). Additionally, there were no significant differences in recovery parameters between weeks with one or two matches. In conclusion, the results suggest that players that underwent NNT tended to improve their sleep quality. Nevertheless, player’s values in the biochemical markers and wellness status remained similar in both groups. The fact that no significant differences were found between weeks with one or two matches could help basketball professionals to determine that a congested schedule does not seem to negatively alter recovery status.post-print1317 K
    corecore