Estudio comparativo de barras corrugadas de diferentes materiales para armar hormigón

[ES] Con el fin de reducir el actual impacto generado de la actividad de la construcción, la arquitectura progresa hacia una práctica más comprometida con el medioambiente, trae consigo el desarrollo de nuevas técnicas, soluciones y materiales alternativos a los tradicionales. Estas variantes deben presentar no únicamente una visión más sostenible, sino que deben asegurar las mismas condiciones de seguridad, servicio y función. Este estudio se centra en los elementos de refuerzo del hormigón, conocidas las barras corrugadas de acero como producto más utilizado en esta práctica, aparecen diferentes alternativas a ellas, como barras corrugadas de acero inoxidable o barras corrugadas de polímeros reforzados con fibras, como las de vidrio o de basalto. Presentado cada una de ellas diferentes propiedades, el objeto de este estudio recae en su comparación. La comparación de estos cuatro tipos de barras corrugadas para armar hormigón se ha realizado atendiendo a sus comportamientos mecánicos, mediante la ejecución propia de ensayos geométricos, ponderales y a tracción. En estos ensayos se analizan las propiedades mecánicas de cuatro muestras de cada uno de los tipos de barras. Por otro lado, con el fin de comparar su aspecto sostenible, debido a las limitaciones que imposibilitan el análisis del ciclo de vida, se lleva a cabo un análisis de la capacidad de los diferentes materiales para adaptarse a las características propias de los materiales sostenibles. Los resultados obtenidos de ambos análisis muestran que las soluciones de barras de polímeros reforzados presentan ciertas propiedades diferentes frente a las de acero y acero inoxidable. Las barras de polímeros reforzados caracterizadas por su comportamiento elástico-lineal con ausencia de límite elástico presentan unas relaciones de peso/resistencias más pequeñas que el resto, lo que se traduce en mayor capacidad de absorber esfuerzos con pesos menores. Así mismo, desde el punto de vista sostenible, estas presentan una buena durabilidad, pero la falta de desarrollo de técnicas que permitan su reciclaje frena su progreso como alternativa real a los materiales tradicionales.[EN] With the aim of reducing the current impact caused by the construction activity, the architecture is moving towards to a better practice more committed to the environment. This results in new techniques, solutions and alternative materials that replace the traditional ones. All of these variant must present not only a sustainable vision, but a same result in terms of security, service and usage. This study is mainly based on the strengthening elements of the concrete dam, known as steel rebars. Although these rebars are the most widely used material on these practices, these are not the only ones, stainless steel, fiber reinforced polymers, basalt or the glass ones are different alternatives of rebars usage. When all of these properties are investigated, the reason for the study is to compare them. All of the comparison, among the four types of rebars has been developed attending to the mechanical behavious through the geometric, asjusted and tensile strenght tests. Furthermore, for the purpose of comparing the environmental aspecto due to the limitations that make the analysis of the life cycle a more complex one, an adaption test in order to know the capacity of the eco-friendly materials is practised. The obtained results in both análisis show that the fiber reinforced polymers rebars present different properties in comparison with the steel or the stainless steel ones. Due to the elastic and lineal behaviour of the FRP rebars with their respective absence of yield point present more reduced weigth and resistance than the other alternatives. In the other words, a greater ability to absorb efforts with lower weight. Similarly, within a sustainable perpective, the FRP rebars display good durability, but the lack of developing techniques that allow its reuse slow down its progress as a real solution to the traditional materials.[CA] Amb la finalitat de reduir l'actual impacte generat de l'activitat de la construcció, l'arquitectura progressa cap a una pràctica més compromesa amb el medi ambient, porta amb si el desenvolupament de noves tècniques, solucions i materials alternatius als tradicionals. Aquestes variants han de presentar no únicament una visió més sostenible, sinó que han d'assegurar les mateixes condicions de seguretat, servei i funció. Aquest estudi se centra en els elements de reforç del formigó, conegudes les barres corrugades d'acer com a producte més utilitzat en aquesta pràctica, apareixen diferents alternatives a elles, com a barres coorugades d'acer inoxidable o barres corrugades de polímers reforçats amb fibres, com les de vidre o de basalt. Presentat cadascuna d'elles diferents propietats, l'objecte d'aquest estudi recau en la seua comparació. La comparació d'aquests quatre tipus de barres corrugades per a armar formigó s'ha realitzat atenent els seus comportaments mecànics, mitjançant l'execució pròpia d'assajos geomètrics, ponderals i a tracció. En aquests assajos s'analitzen les propietats mecàniques de quatre mostres de cadascun dels tipus de barres. D'altra banda, amb la finalitat de comparar el seu aspecte sostenible, a causa de les limitacions que impossibiliten l'anàlisi del cicle de vida, es realitza una anàlisi de la capacitat dels diferents materials per a adaptar-se a les característiques pròpies dels materials sostenibles. Els resultats obtinguts dels anàlisis mostren que les solucions de barres de polímers reforçats presenten unes propietats diferents enfront de les d'acer i acer inoxidable. Les barres de polímers reforçats caracteritzades pel seu comportament elàstic-lineal amb absència de límit elàstic presenten unes relacions de pes/resistència més baixes que la resta, la qual cosa es tradueix en major capacitat d'absorbir esforços amb pesos menors. Així mateix, des del punt de vista sostenible, aquestes presenten una bona durabilitat, però la falta de desenvolupament de tècniques que permeten el seu reciclatge frena el seu progrés com a alternativa real als materials tradicionals.Torres Vegara, FJ. (2018). Estudio comparativo de barras corrugadas de diferentes materiales para armar hormigón. http://hdl.handle.net/10251/115193TFG

A Selective Change Driven System for High-Speed Motion Analysis

Vision-based sensing algorithms are computationally-demanding tasks due to the large amount of data acquired and processed. Visual sensors deliver much information, even if data are redundant, and do not give any additional information. A Selective Change Driven (SCD) sensing system is based on a sensor that delivers, ordered by the magnitude of its change, only those pixels that have changed most since the last read-out. This allows the information stream to be adjusted to the computation capabilities. Following this strategy, a new SCD processing architecture for high-speed motion analysis, based on processing pixels instead of full frames, has been developed and implemented into a Field Programmable Gate-Array (FPGA). The programmable device controls the data stream, delivering a new object distance calculation for every new pixel. The acquisition, processing and delivery of a new object distance takes just 1.7 μ s. Obtaining a similar result using a conventional frame-based camera would require a device working at roughly 500 Kfps, which is far from being practical or even feasible. This system, built with the recently-developed 64 × 64 CMOS SCD sensor, shows the potential of the SCD approach when combined with a hardware processing system

Taking Advantage of Selective Change Driven Processing for 3D Scanning

This article deals with the application of the principles of SCD (Selective Change Driven) vision to 3D laser scanning. Two experimental sets have been implemented: one with a classical CMOS (Complementary Metal-Oxide Semiconductor) sensor, and the other one with a recently developed CMOS SCD sensor for comparative purposes, both using the technique known as Active Triangulation. An SCD sensor only delivers the pixels that have changed most, ordered by the magnitude of their change since their last readout. The 3D scanning method is based on the systematic search through the entire image to detect pixels that exceed a certain threshold, showing the SCD approach to be ideal for this application. Several experiments for both capturing strategies have been performed to try to find the limitations in high speed acquisition/processing. The classical approach is limited by the sequential array acquisition, as predicted by the Nyquist - Shannon sampling theorem, and this has been experimentally demonstrated in the case of a rotating helix. These limitations are overcome by the SCD 3D scanning prototype achieving a significantly higher performance. The aim of this article is to compare both capturing strategies in terms of performance in the time and frequency domains, so they share all the static characteristics including resolution, 3D scanning method, etc., thus yielding the same 3D reconstruction in static scenes

Adicción a cannabis: bases neurobiológicas y consecuencias médicas

La adicción a los preparados de cannabis sativa es un problema relevante en nuestra sociedad, con especial importancia durante la adolescencia. Su fácil disponibilidad y los episodios adversos asociados a su abuso y/o dependencia han incrementado la demanda de tratamiento derivada por su consumo. En los últimos 20 años se ha podido avanzar mucho sobre la farmacología del cannabis y de sus principios activos, moléculas grasas que actúan a través de un sistema de señalización endógeno denominado sistema endocannabinoide implicado en el desarrollo y la plasticidad cerebrales. Su estimulación crónica puede inducir no sólo dependencia y adicción, sino también derivar en consecuencias neurobiológicas que tienen repercusión clínica. Así, por un lado se puede encontrar el incremento de trastornos mentales tanto primarios como inducidos (trastornos del estado de ánimo, trastornos de ansiedad y trastornos psicóticos) y por el otro, alteraciones en los procesos cognitivos (memoria, atención, toma de decisiones, asunción de riesgos, control de impulsos). Estas consecuencias son más graves si el consumo se realiza en la adolescencia. Algunos de estos efectos son permanentes y el conocimiento de los mismos necesario para una correcta atención sanitaria.Addiction to products derived from the plant cannabis sativa has become a relevant problem in western societies. Its prevalence in both teenagers and young adults has grown in the last decade. The problem is aggravated by the availability of plant derivatives with a high THC content. Today, the number of cannabis users requesting medical treatment is growing, as well as the incidence and variety of the adverse effects associated with its chronic consumption. On the other hand, the last 20 years' research have revealed the hidden pharmacology of the active principles of cannabis. Cannabinoids, the psychoactive chemicals of the plant, exert their pharmacological actions through their interaction with an endogenous signaling system, the endocannabinoid system. This system is involved in brain development, plasticity and repair, and its chronic stimulation can induce not only dependence/addiction, but also result in adverse clinical effects. The negative side of cannabis use has greatest impact in the adolescent period. The main adverse effects of chronic cannabis use include the increase in the incidence of mental disorders (mainly psychosis), as well as alterations in cognitive processes including memory, attention, decision-making, risk behaviors as well as impulsivity. Some of these effects are permanent and information and research on their nature is greatly needed in order to achieve a correct public health approach to cannabis use

Mathematical Morphology for Color Images: An Image-Dependent Approach

This paper proposes one possibility to generalize the morphological operations (particularly, dilation, erosion, opening, and closing) to color images. First, properties of a desirable generalization are stated and a brief review is done on former approaches. Then, the method is explained, which is based on a total ordering of the colors in an image induced by its color histogram; this is valid for just one image and may present problems in smoothly coloured images. To solve these drawbacks a refinement consisting of smoothing the histogram and using a joint histogram of several images is presented. Results of applying the so-defined morphological operations on several sets of images are shown and discussed

Amylolytic Activities Excreted by the Halophilic Archaeon Haloferax mediterranei to Assimilate Available Starch Depend on the Nitrogen Source

Several amylolytic activities have been isolated from a controlled growing media containing starch and nitrate or ammonium acetate as a carbon and energy source, excreted by the halophilic archaeon Haloferax mediterranei. These enzymes produced in nitrate-containing medium were different from those produced by the organism when cultured in ammonium acetate-containing medium. Haloferax mediterranei was able to grow optimally in both the media but not in a medium with ammonium chloride and starch as exclusive source of nitrogen and carbon, respectively. Growth was significantly lower when nitrate was replaced by ammonium, although there was significant amylolytic activity in the medium. At least six different activities were obtained in the nitrate-containing medium, but only five for the ammonium containing one. These enzymes displayed a different affinity for starch as a chromatographic matrix, when eluted with maltose in a range from 0.02 M to 0.2 M, and differed in their kinetic parameters for starch as a substrate. The average medium length of the products obtained from cracking starch was different for each amylolytic activity, ranging from glucose to larger polysaccharides. Moreover, they exhibited different molecular masses, from 15 to 80 kDa. On the other hand, all of them behaved as typical halophilic enzymes, requiring high salt concentrations from 2M to 4M NaCl for stability and activity. Also, it exhibited an optimal pH ranged from 7 to 8 and showed certain thermophilic behaviour, with maximal activity within 50°C to 60°C. The study of the presence and behaviour of this set of starch degrading enzymes will allow for a better understanding of how halophilic organism obtain the adequate carbohydrates to be incorporated and optimally used.This work was supported by project BIO2013-42921-P from the Spanish Ministry of Economy and Competitiveness

Sustainable Environmental Strategies for Shrinking Cities Based on Processing Successful Case Studies Facing Decline Using a Decision-Support System

Since the middle of the last century post-industrial cities around the world have been losing population and shrinking due to the decline of their structural growth models, showing important socioeconomic transformations. This is a negative phenomenon but one that cities can benefit from. The aim of this work is to verify what type of measures against urban decline would be most suitable if applied to a specific case study. To do this, international cases of shrinking cities where successful measures were already carried out facing decline: (i) are collected, (ii) are classified based on several influencing criteria, and (iii) are grouped under similar alternatives against the decline. Measures and criteria focused on achieving sustainability are emphasized. Alternatives are then prioritised using an Analytic Hierarchy Process designed at several hierarchical levels. The results are discussed based on the construction of sustainable future scenarios according to the optimal alternatives regarding the case study, improving the model validity. The work evidences that environmental and low-cost measures encouraging the economy and increasing the quality of life, regardless of the city size-population range where they were performed, may be the most replicable. Future research lines on the integration of the method together with other decision-support systems and techniques are provided

Selective Change Driven Imaging: A Biomimetic Visual Sensing Strategy

Selective Change Driven (SCD) Vision is a biologically inspired strategy for acquiring, transmitting and processing images that significantly speeds up image sensing. SCD vision is based on a new CMOS image sensor which delivers, ordered by the absolute magnitude of its change, the pixels that have changed after the last time they were read out. Moreover, the traditional full frame processing hardware and programming methodology has to be changed, as a part of this biomimetic approach, to a new processing paradigm based on pixel processing in a data flow manner, instead of full frame image processing

CETA. Entre el pueblo y la ciudad.

[ES] El Trabajo Final de Máster se basa en el diseño de un Centro de Estudios Tecnológicos Avanzados, donde la localización escogida es Benimamet, una pedanía de Valencia situada al noroeste de la ciudad. Benimamet recientemente ha sufrido algunas transformaciones urbanísticas para acomodar y dotar al pueblo de nuevos espacios públicos. La ejecución del soterramiento de las vías de tren, y su uso como recorrido de metro, ha provisto al pueblo de un parque lineal que lo cruza de este a oeste. Este nuevo elemento verde trae consigo una nueva forma de entender los espacios que lo rodean, ya que parece necesario un diseño en conjunto para potenciar aún más la presencia de este elemento que aporta al pueblo un espacio público tanto de conexión como de ocio. Debido a ello es que la parcela en la que se sitúa el proyecto se encuentra vinculada a este nuevo elemento verde, y contiguo al futuro parque Carolinas. La parcela cuenta con 25.000 m2, donde se resuelve tanto la ordenación urbanística como la ejecución del proyecto que alberga el programa exigido, ateniendo a las diferentes tensiones que aparecen en ella. Entre otras se puede destacar algunas como las pre-existencias en su interior, la parada de metro que conecta con la ciudad o el gran desnivel que existe entre el parque lineal y la parcela. El programa genera que el proyecto se entienda en gran parte como un equipamiento educativo, pero al mismo tiempo cuenta con diferentes servicios que permite que su uso no sea exclusivamente docente. Este hecho se ve reforzado por su ubicación, que hace pensar que no será un equipamiento únicamente de pueblo, si no que será ocupado tanto por personas de Benimament como de la propia ciudad de Valencia, por lo que es preciso dotarlo de espacios con funciones alternativas pero compatibles con la docencia. El Centro de Estudios Tecnológicos Avanzados, se basará en la docencia de ciclos formativos de tres ramas profesionales como son: Electricidad y Electrónica, Informática y Comunicaciones y por último, Imagen y Sonido. Serán cincos las áreas que compongan el programa: Administración y gestión del centro; servicios generales; espacios complementarios tales como cafetería, auditorio o gimnasio entre otros; espacios exteriores y una última área que comprende todos aquellos espacios necesarios para la docencia de cada una de las familias profesionales que alberga el centro.[EN] This Final Master Project is based on the design of a Centre for Advanced Technological Studies, for which chosen location is Benimamet, a Valencian village located in the city s north-west. Benimamet has recently experienced some urbanistic transformations accommodate and provide its people new public spaces. The execution of the train track burial, and its use as subway, has equipped the village with a linear park from east to west. This new green element brings with it a new way of understanding the public spaces around it, as a joint design seems to be needed in order to boost even more the presence of this element which contributes with both connection and leisure. As a consequence, the project plot is linked with this new green element and adjacent to the upcoming Parque Carolinas. The plot is 25.000 m2 long, which suits both the town planning and the project execution included in the plan required, meeting the different stresses on it. Amongst others, we may remark a few of them such as the pre- existences in its interior, the metro station or the huge unevenness between the linear park and the plot. The plan makes the project to be mostly understood as educational equipment, but at the same time, it has different services that enables it not to be solely used for educational purposes. This fact is enhanced by its location, leading to believe that it will not be just village equipment, but it will be occupied by people from Benimamet and Valencia itself, so it has to be provided with alternative functions different from education. The Centre for Advanced Technological Studies will be based on the teaching off formative cycles from three different professional branches: Electricity and Electronics, Computing and Communications and, by last, Image and Sound. It will be five the areas to shape the project: Centre Administration and Management, General Services, Complementary Spaces (such as cafeteria, auditorium and gym), Outdoor Areas and a last area that includes those necessary spaces for the teaching of each of the different professional branches existing in the Centre.Torres Vegara, FJ. (2020). CETA. Entre el pueblo y la ciudad. Universitat Politècnica de València. http://hdl.handle.net/10251/176651TFG