201 research outputs found

    Changing Priorities. 3rd VIBRArch

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    In order to warrant a good present and future for people around the planet and to safe the care of the planet itself, research in architecture has to release all its potential. Therefore, the aims of the 3rd Valencia International Biennial of Research in Architecture are: - To focus on the most relevant needs of humanity and the planet and what architectural research can do for solving them. - To assess the evolution of architectural research in traditionally matters of interest and the current state of these popular and widespread topics. - To deepen in the current state and findings of architectural research on subjects akin to post-capitalism and frequently related to equal opportunities and the universal right to personal development and happiness. - To showcase all kinds of research related to the new and holistic concept of sustainability and to climate emergency. - To place in the spotlight those ongoing works or available proposals developed by architectural researchers in order to combat the effects of the COVID-19 pandemic. - To underline the capacity of architectural research to develop resiliency and abilities to adapt itself to changing priorities. - To highlight architecture's multidisciplinarity as a melting pot of multiple approaches, points of view and expertise. - To open new perspectives for architectural research by promoting the development of multidisciplinary and inter-university networks and research groups. For all that, the 3rd Valencia International Biennial of Research in Architecture is open not only to architects, but also for any academic, practitioner, professional or student with a determination to develop research in architecture or neighboring fields.Cabrera Fausto, I. (2023). Changing Priorities. 3rd VIBRArch. Editorial Universitat Politècnica de València. https://doi.org/10.4995/VIBRArch2022.2022.1686

    Development of resonant cavity-based microwave filters for axion detection

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    [SPA] Esta tesis doctoral aborda varias investigaciones para la detección de axiones y para la mejora de comunicaciones satelitales mediante el uso de cavidades resonantes en tecnología guía de onda. El axión es una partícula hipotética teorizada para resolver el problema CP fuerte (Charge conjugation Parity symmetry) en la cromodinámica cuántica (QCD) y que, de existir, podría ser componente de la materia oscura. En esta línea, el desarrollo de detectores axiónicos de materia oscura, comúnmente denominados haloscopios, se ha encontrado en auge en los últimos 20 años. En este trabajo se han desarrollado diversos métodos para la mejora de estos haloscopios empleando estructuras basadas en subcavidades conectadas por irises. Por otro lado, es bien sabido que el espectro electromagnético en las comunicaciones por satélite se encuentra saturado debido a la alta demanda de radiocomunicaciones hoy en día. Además, el coste de puesta en órbita de un satélite crece exponencialmente con el peso abordo de éste, cuya reducción será clave en cualquier programa espacial. Así, en esta tesis se abordan diversos diseños de filtros paso banda en guía de onda para la optimización del peso, volumen y huella abordo de los futuros satélites de comunicaciones. El espectro frecuencial barrido por la comunidad axiónica en busca de la ansiada partícula (el axión) es cada día mayor y hace que exista una alta competencia para participar en esta búsqueda con detectores de altas prestaciones. Además, las condiciones extremas a las que debe ser sometido un detector de axiones de materia oscura para que se cumplan las condiciones de detección (temperaturas criogénicas, campo magnetoestático alto, etc.) complican aún más esta tarea. Algunos de los parámetros que rigen el rendimiento de un haloscopio basado en cavidades resonantes son su volumen, factor de calidad y factor de forma. Durante la elaboración de este trabajo se han diseñado, fabricado y caracterizado diversas topologías novedosas para la creación de estos detectores, optimizando los tres parámetros mencionados, consiguiendo resultados satisfactorios. Esta tesis doctoral ha sido realizada en el marco de trabajo del grupo axiónico RADES (Relic Axion Detector Exploratory System). Se han llevado a cabo tareas de investigación para la mejora del factor de calidad en estructuras fabricadas en las primeras etapas por este grupo experimental mediante la aplicación de diversos tratamientos, como la aplicación de soldaduras. Además de la optimización de los parámetros en haloscopios, estos necesitarán escanear un espectro de frecuencias, como se ha mencionado anteriormente, para lo cual se deberá implementar sistemas de sintonía que permita el cambio de frecuencia de resonancia y otros sistemas para el ajuste del acoplamiento de entrada / salida del sistema (otro de los parámetros críticos del detector). Existen dos tipos de sintonía frecuencial, mecánica y electrónica. Para los sistemas de sintonía mecánicos, se han realizado estudios del comportamiento de los prototipos fabricados cuando estos se abren mediante un corte vertical, lo cual cambiará su frecuencia de búsqueda del axión. Por otro lado, para los sistemas de sintonía electrónicos se han desarrollado diversos diseños para la introducción de materiales ferromagnéticos y ferroeléctricos, que cambiarán la frecuencia de operación mediante el cambio de permeabilidad y permitividad del medio, respectivamente, aplicando un cambio de voltaje o temperatura. Se ha hecho un estudio mucho más extenso para estos últimos. Los sistemas electrónicos permiten evitar ciertos problemas que ocurren en los de tipo mecánico, como pueden ser fallos de movimiento a temperaturas criogénicas o la falta de escalabilidad. Para los elementos ferroeléctricos, se ha llegado a un diseño novedoso que ha aportado gran valor a la comunidad científica para la aplicación de este tipo de materiales en cualquier haloscopio. Además, se han desarrollado sistemas de acoplamiento entre subcavidades con láminas ferroeléctricas, evitando la fabricación de irises, los cuales pueden dar problemas en ciertos sistemas. Para los sistemas de ajuste de acoplamiento de entrada / salida, se ha desarrollado un prototipo preliminar que ha aportado buenos resultados experimentales. Asimismo, se han llevado a cabo otras tareas de investigación para el desarrollo de otras técnicas de mejora de haloscopios. Una de ellas es la del rechazo de resonancias no deseados cerca del modo axiónico por medio de la combinación de varios puertos coaxiales con el método phase-matching, para el cual se han realizado diversas simulaciones y fabricaciones, extrayendo resultados positivos que hacen viable dicho método. Otros estudios secundarios han sido los de la implementación de QuBits para reducir la temperatura del sistema (parámetro clave para el rendimiento), el uso de elementos HTS (High Temperature Superconductor) para aumentar el factor de calidad, el diseño de haloscopios a frecuencias en las bandas UHF y W, y el análisis electromagnético del acoplamiento axion-photon en haloscopios mediante el método BI-RME (Boundary Integral-Resonant Mode Expasion) 3D. Finalmente, como spin-off del desarrollo de haloscopios, se han realizado diversos estudios para el diseño, fabricación, caracterización y mejora de filtros paso banda para comunicaciones satelitales empleando la misma tecnología (cavidades resonantes acopladas por irises en guía de onda). Se ha han desarrollado varios filtros evanescentes basados en impresión 3D o fabricación aditiva de bajo coste, y mecanizado CNC (Computer Numerical Control). A estos filtros se les ha aplicado un sistema de sintonía de tornillos que ha permitido la mejora de la respuesta eléctrica de filtrado. Por otro lado, se ha llevado a cabo el diseño de un filtro asimétrico doblado horizontalmente para la implementación de ceros de transmisión, consiguiente un alto rechazo fuera de la banda de paso. Estos filtros son gran valor para la comunidad científica ya que permiten avanzar en el estado del arte de filtros con altas prestaciones (bajo peso, volumen y huella) para comunicaciones satelitales. [ENG] This PhD thesis addresses several investigations for the detection of axions and for the improvement of satellite communications using resonant cavities in waveguide technology. The axion is a hypothetical particle theorized that could explain the strong CP problem (Charge conjugation Parity symmetry) in quantum chromodynamics (QCD) and which, if it exists, could be a component of dark matter. In this line, the development of axion dark matter detectors, commonly called haloscopes, has been booming in the last 20 years. In this work, several methods have been developed for the improvement of these haloscopes using structures based on subcavities coupled by irises. On the other hand, it is well known that the electromagnetic spectrum in satellite communications is saturated due to the high demand for radio communication systems. In addition, the cost of putting a satellite into orbit grows exponentially with the weight on board, the reduction of which will be key in any space program. Thus, this PhD thesis deals with different waveguide bandpass filter designs for optimizing the weight, volume, and on-board footprint of future communication satellites. The frequency spectrum swept by the axion community in search of the coveted particle is increasing day by day, which means that there is a high level of competition to develop high-performance detectors. In addition, the extreme conditions to which a dark matter axion detector must be subjected in order to meet the detection conditions (cryogenic temperatures, high magnetostatic field, etc.) further complicate this task. Some of the parameters that govern the performance of a haloscope based on resonant cavities are its volume, quality factor and form factor. During the development of this work, several novel topologies have been designed, manufactured, and characterized for the creation of these detectors, optimizing the three above-mentioned parameters, achieving satisfactory results. This PhD thesis has been carried out within the framework of the RADES (Relic Axion Detector Exploratory System) axion group. Research work has been carried out to improve the quality factor in structures manufactured in the first stages of this experimental group through the application of various treatments, such as soldering. In addition, as the axion mass is unknown, it is important to scan in frequency to search for the axion over a range as large as possible, as mentioned above, for which tuning systems must be implemented to allow resonant frequency shift and other arrangements for adjusting the input / output coupling of the system (another key haloscope parameter). There are two types of frequency tuning, mechanical and electronic. For mechanical tuning systems, studies have been carried out on the behaviour of the fabricated prototypes when they are opened by a vertical cut, which will change their axion search frequency. On the other hand, for electronic tuning systems, various designs have been developed for the introduction of ferromagnetic and ferroelectric materials, which will change the operating frequency by changing the permeability and permittivity of the medium, respectively, by applying a change of voltage or temperature. A much more extensive study has been made for the use of ferroelectric tuning systems. Electronic systems avoid certain problems that occur in mechanical systems, such as motion failure at cryogenic temperatures or lack of scalability. For ferroelectric elements, a novel design as been achieved which has brought great value to the scientific community for the application of this type of material in any haloscope. Also, coupling systems have been developed between subcavities with ferroelectric films, avoiding the need to manufacture irises, which can cause problems in certain systems. For the input / output coupling adjustment systems, a preliminary prototype has been developed which has provided good experimental results. Other research works have also been carried out on the development of other haloscope enhancement techniques. One of them is the rejection of unwanted resonances near the axion mode by means of the combination of several coaxial ports with the phase-matching method, for which several simulations and fabrications have been carried out, obtaining positive results that make this method feasible. Other secondary studies have been the implementation of QuBit devices to reduce the system temperature (another key parameter for haloscope performance), the use of HTS (High Temperature Superconductor) elements to increase the quality factor, the haloscope design at frequencies in the UHF and W bands, and the electromagnetic analysis of axion-photon coupling in haloscopes using the BI-RME (Boundary Integral-Resonant Mode Expansion) 3D method. Finally, as a spin-off from the development of haloscopes, several studies have been carried out for the design, manufacture, characterization, and improvement of bandpass filters for satellite communications using the same technology (resonant cavities coupled by irises in waveguide). Several evanescent filters based on 3D printing or low-cost additive manufacturing and CNC (Computer Numerical Control) machining have been developed. A screw tuning system has been applied to these filters to improve the electrical filtering response. On the other hand, the design of a horizontally folded asymmetric filter for the implementation of transmission zeros, to increase the rejection capabilities of the filter, has been carried out. These filters could be of great value to the scientific community as they allow to advance in the state of the art of high-performance filters (low weight, volume, and footprint) for satellite communications.Escuela Internacional de Doctorado de la Universidad Politécnica de CartagenaUniversidad Politécnica de CartagenaPrograma Doctorado en Tecnologías de la Información y las Comunicacione

    PROCEEDINGS 5th PLATE Conference

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    The 5th international PLATE conference (Product Lifetimes and the Environment) addressed product lifetimes in the context of sustainability. The PLATE conference, which has been running since 2015, has successfully been able to establish a solid network of researchers around its core theme. The topic has come to the forefront of current (political, scientific & societal) debates due to its interconnectedness with a number of recent prominent movements, such as the circular economy, eco-design and collaborative consumption. For the 2023 edition of the conference, we encouraged researchers to propose how to extend, widen or critically re-construct thematic sessions for the PLATE conference, and the paper call was constructed based on these proposals. In this 5th PLATE conference, we had 171 paper presentations and 238 participants from 14 different countries. Beside of paper sessions we organized workshops and REPAIR exhibitions
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