Abstract: In the present work, theoretical and experimental analysis of the thermal performance of flat plate pulsating heat pipes, made of copper, are presented. The pulsating heat pipes were manufactured using an innovative fabrication process for this application, the diffusion bonding. For this purpose, a special oven was used, available in Labtucal, that provides high temperature, high pressure and high vacuum conditions, which allows the fabrication of monolithic pieces with high reliability. Plates of equal external size were used, in which the internal channels were modified. Different geometries were applied, including the variation of the number of channels for the same overall dimensions (density increase), modifications of the surface finishing (roughness) and addition of lateral grooves at evaporator section. Flat plate pulsating heat pipes were tested under different operating conditions, such as tilt angles, heat input levels, and filling ratios, concluding that higher roughness or grooves at evaporator zone enhance the thermal performance of the devices, as start-up time, thermal resistance and thermal stability. However, the most relevant parameters, to decrease the dependence of the gravity in the operation of the pulsating heat pipe, are the number of channels and the working fluid filling ratios. A mathematical model, based on electrical circuit analogy, is constructed, taking into consideration the activation energy. Model validation was made with the experimental date obtained from the devices developed in this thesis. The model presented a maximum error of 25-30%, at vertical bottom heat mode and vertical top heat mode. The main contributions of this Ph.D. thesis are: the development of modified pulsating heat pipes using effective thermal improvements; the production of a reliable fabrication process compatible with the proposed thermal enhancements and, finally, a model that can be used as a design tool for pulsating heat pipes fabricated from machined plates. Resumen: En el presente trabajo, se realiza un análisis teórico y experimental del desempeño térmico de tubos de calor pulsantes de placa plana, fabricados en cobre. Los tubos de calor pulsantes fueron fabricados utilizando un proceso de fabricación innovador para esta aplicación, la difusión vinculación. Para ello se utilizó un horno especial, disponible en Labtucal, que proporciona alta temperatura, alta presión y alto vacío, lo que permite la fabricación de piezas monolíticas de alta confiabilidad. Se utilizaron placas de igual tamaño externo, en las que el Se modificaron los canales internos. Se aplicaron diferentes geometrías, incluyendo la variación de el número de canales para las mismas dimensiones generales (aumento de densidad), modificaciones del acabado superficial (rugosidad) y adición de ranuras laterales en la sección del evaporador. placa plana Los tubos de calor pulsantes se probaron en diferentes condiciones de funcionamiento, como ángulos de inclinación, calor suministrado, relaciones de llenado, concluyendo que una mayor rugosidad o ranuras en la zona del evaporador mejora el rendimiento térmico de los dispositivos, como el tiempo de inicio de operación, la resistencia térmica y la estabilidad de la temperatura. Sin embargo, los parámetros más relevantes, para disminuir la dependencia de la gravedad en el funcionamiento del tubo de calor pulsante, fueron el número de canales y las proporciones del llenado de fluido de trabajo. Se construye un modelo matemático, basado en la analogía del circuito eléctrico, tomando en Consideración la energía de activación. La validación del modelo se realizó con los datos experimentales obtenidos a partir de los dispositivos desarrollados en esta tesis. Las principales contribuciones de este doctorado tesis son: el desarrollo de tubos de calor pulsantes modificados utilizando mejoras térmicasla producción de un proceso de fabricación confiable y un modelo que se puede utilizar como herramienta de diseño.

Abstract: The aim of this research was to investigate the combustion behaviour of coal and biomass blends using a pilot-scale bubbling fluidised bed reactor. The blends were prepared with a traditionally used biomass fuel (i.e. wood) and selected rich in alkali-metals biomass fuels (i.e. wheat straw and spent coffee grounds (SCG)) to investigate the potential of SCG as a fuel and the effect of ilmenite on agglomeration tendency when used as an additive and alternative bed material. To elucidate the interaction between the fuels in the blends and the effect of ash composition, thermogravimetric and ash fusibility studies were performed looking at both the parent fuels and blends. Initially, thermogravimetric studies focused on understanding the thermal decomposition of coal blended with by-products (spent coffee ground (SCG), and coffee husk (CH)) of coffee crop. Blends with wood were included for comparison purpose. The blends were prepared by blending coal with biomass at 10, 30 and 50 wt%. The experiments were performed under inert and oxidising conditions to elucidate the thermal behaviour and fuel interactions. The results showed that the inclusion of either spent coffee grounds or coffee husk in coal combustion can enhance the combustion performance. Indeed, the blends with spent coffee grounds were found to be more reactive than those with coffee husk and with similar characteristics to the blends with wood. It was attributed to the existence of synergistic effects. These results offer compelling evidence of the potential of by-products from the coffee crop, especially spent coffee grounds for energetic applications. The study of ash fusibility characteristics investigated the ash fusibility temperatures under oxidising conditions of coal ash blended with ash from spent coffee grounds. Blends with wheat straw ash were included for comparison purpose. Particular attention was paid to the blending ratio effect on ash fusibility temperatures. The results showed that SCG is an interesting fuel in co-processing due to the low ash content and high ash fusibility temperatures when blended with coal. The high ash fusibility temperatures of the blends were attributed to the high content of CaO, MgO, and P2O5 in SCG with negligible content of SiO2 and Cl, complementing the high content of Al2O3 and Fe2O3 in coal. Evidence from this study suggests that the high ash fusion temperatures in the blends of coal with spent coffee grounds can reduce the common operational issues related to biomass ash such as agglomeration. This can also provide confidence for large scale thermochemical conversion systems fuelled by such kind of coal and biomass blends to be able to maintain long-term stable operation. The final part of this research focused on co-combustion experiments in a pilot-scale BFB aiming to investigate the potential of SCG as a fuel, and ilmenite as an additive and alternative bed material. For comparison purpose blends of coal with wheat straw and wood pellets were also combusted in the same BFB reactor under similar combustion conditions. Similarly, kaolin and bauxite, and silica sand were compared to ilmenite when used as an additive and alternative bed material, respectively. The inclusion of biomass in coal combustion showed marked differences in the temperature profiles, gas emissions, and combustion performance. The results showed that coal and SCG blends can be combusted for energy applications with improved combustion efficiency compared to wheat straw and wood commercial pellets. Nevertheless, high N content in SCG represents a challenge in terms of NOx emissions that should be addressed.

Within the last decade circuit quantum electrodynamics (circuit QED) [1] has proven to be an excellent platform to study the coherent interaction between an artificial atom and a light field. Here an artificial atom, or more precisely an effective two level system, is realized using superconducting circuitry while the cavity is realized as a microwave resonator. Recently, an effective two level system realized using a semiconductor double quantum dot (DQD) has been coupled to a microwave resonator. In this hybrid system, interactions between the dipole moment of (single) electrons in a DQD and the electromagnetic field in a microwave resonator have been observed (2,3). Using the same architecture, we initially discuss experiments performed with a resonator sample in order to investigate design parameters influencing its quality factor. With the aim of enabling high bandwidth correlation measurements, we then present the design and implementation of parallel digital filters in a digital signal processing platform. We finally report on experiments to use the microwave resonator as a tool to explore fundamental processes occurring in a DQD driven out-of-equilibrium. In particular, we perform exploratory attempts to probe the microwave radiation emitted from a voltage-biased DQD by means of first and second order correlation function measurements. Resumen: En la última década, la electrodinámica cuántica de circuitos (circuit QED) [1] ha demostrado ser una excelente plataforma para estudiar la interacción coherente entre un átomo artificial y un campo de luz. El esquema consiste en un átomo artificial, o más precisamente un sistema efectivo de dos niveles, implementado usando circuitos superconductors, mientras que la cavidad se implementa como un resonador de microondas. Recientemente, se ha acoplado un sistema de dos niveles, implementado utilizando un punto cuántico doble de semiconductores (DQD), a un resonador de microondas. En este sistema híbrido, se han observado interacciones entre el momento dipolar de electrones (individuales) en un DQD y el campo electromagnético en un resonador de microondas [2,3]. Utilizando la misma arquitectura, inicialmente discutimos experimentos realizados con un resonador para investigar los parámetros de diseño que influyen en su factor de calidad. Con el objetivo de permitir mediciones de correlación de alto ancho de banda, presentamos el diseño e implementación de filtros digitales paralelos en una plataforma de procesamiento digital de señales. Finalmente, presentamos experimentos para utilizar el resonador de microondas como herramienta para explorar los procesos fundamentales que ocurren en un DQD operado fuera de equilibrio. En particular, realizamos intentos exploratorios para sondear la radiación de microondas emitida por un DQD (polarizado con una diferencia de voltage) por medio de mediciones de la función de correlación de primer y segundo orden.

In 2019, the European Commission published the “2030 Clean Energy for All Europeans” package, as part of the 2050 Energy roadmap. To comply with the European directives, Italy published the National Energy and Climate Plan setting a target of 55% for RES share in electricity generation by 2030. This high RES generation target raises concerns about the operational flexibility of the Italian power system. The flexibility of the Italian power system was measured using currently available flexibility frameworks and indexes (e.g.: AFPER, FAST2). Hence, the 2030 Base Scenario and 15 alternative scenarios were simulated using Promed Grid, a market tool developed by CESI and able to perform a coordinated hydro- thermal dispatching over a one-year horizon, considering the adoption of some flexibility sources such as storage systems and demand response. The results were then compared to characterize the performance of each flexibility source and its influence on the power system. BESS, PHS, and DR showed a level of complementarity while covering flexibility needs and controlling price spikes. Daily needs are covered mainly by BESS and weekly needs by PHS, mainly during the summer since both technologies were more used due to high solar power generation. Conversely, peak shedding DR was primarily activated in winter since prices are higher and storage systems lees used. In the case of V2G and DR, the role of aggregators is vital to have a representative capacity to be offered in the power markets. Finally, from a holistic perspective, the benefits of implanting all flexibility source are higher than the costs. Nevertheless, such benefits should be redistributed to incentivize the deployment of certain sources with low benefit-cost ratios. The results of this thesis can serve as a starting point to delve into the technical performance and economic implications of each flexibility source. In addition, it highlighted the advantages for Italy of boosting and supporting some schemes such as DR and V2G, as well as incentivizing the installation of storage systems.

Después de muchos años de consultoría y asesoría empresarial en busca de una herramienta para el cambio de los programas de salud ocupacional hacia los sistemas de gestión en seguridad y salud en el trabajo desde el pensamiento lineal al sistémico; en esta búsqueda pude construir los 7 Pasos para formular el sistema de gestión sobre todo orientando a las pequeñas y medianas empresas que por su estructura y organización es muy difícil la planificación e implementación del sistema de seguridad y salud en el trabajo.

The excavation for the 53-story reinforced concrete One Museum Park West building (OMPW) in Chicago was constructed using combined support systems. The building was supported by caissons and a perimeter wall formed by secant piles which transitioned to tangent piles below the bottom of the cut. After installing the perimeter wall and deep foundations for the building, the excavation for the reinforced concrete central core was supported by a circular cofferdam made of sheet piles and steel ring beams. This excavation was made using conventional bottom-up excavation techniques. The excavation for the rest of the building was made using a top-down method and was laterally braced with reinforced concrete floor slabs structurally connected to the secant pile walls and the reinforced concrete core. Field performance data during construction of the OMPW basements were collected with settlement points, inclinometers and strain gages installed in the concrete basement slabs. Significant settlements were observed adjacent to the excavation during wall and deep foundation installation, central core construction and top-down excavation. The influence of concrete material time-dependence of the floor slabs on the performance during top-down excavation is evaluated and a method for the separation of temperature-related strains from the excavation-induced strains in the concrete is described. The construction of the basements is simulated with a 3D numerical structural model to study the influence of the concrete material time-dependence of the floor slabs in the excavation-induced movements resulting from top-down construction. Computed strains in the floor slabs are compared with the observed performance data collected from the strain gages. For use in numerical simulation of the entire excavation process, hypoplasticity constitutive parameters for clays (HC model) at the element test level were calibrated with tests conducted on high quality block samples obtained from the excavation of Block 37 project in Chicago. They included oedometer tests, bender element measurements, and triaxial tests following different stress probes, and were further refined with seismic cone penetration results.  The entire OMPW excavation is simulated with the calibrated parameters with a fully coupled-flow deformation, three-dimensional finite element model. Influence of the construction of secant pile walls, concrete material time-dependence, and nonlinear concrete behavior of the perimeter pile walls on the performance of the OMPW excavation is determined. Conclusions about top-down construction are drawn in light of the measured and simulated performance of the OMPW excavation.

El proyecto será ejecutado por un grupo de dos estudiantes que optan por el título de Especialista en Gerencia, otorgado por la Universidad Externado de Colombia, quienes como producto de su emprendimiento realizaron las correspondientes investigaciones y desarrollaron el proyecto, invirtiendo sus propios recursos, tanto intelectuales como económicos. El concepto del negocio es la creación de una empresa de Servicios de automatización inteligente de viviendas –domótica, en donde se ofrezcan los productos y Servicios necesarios para cubrir la demanda de seguridad, comodidad y tecnificación requerido para los estratos 4, 5 y 6 de la localidad de Suba de la ciudad de Bogotá. Dentro de la oferta comercial se cuenta con 5 líneas de producto que conforman el portafolio general. El servicio incluye la instalación de todos los productos, demostrando su funcionalidad y dando garantía de los mismos. La estrategia comercial está enfocada en la innovación con tecnología de punta, un servicio técnico de alta calidad y respaldo de garantía a un precio razonable que permita crear espacios con seguridad, confort y entretenimiento. Los análisis financieros mostraron que el proyecto es factible ya que después de realizar la operación de cada periodo la liquidez de la compañía es muy buena.

Abstract: The manufacturing brick generates a direct effect in the air quality affecting the health of the surrounding communities of this type of industry. In the Colombian municipality of Nemocón, in the Patio Bonito rural locality, the majority of small and micro-sized brick fields uses craft techniques for manufacturing different types of bricks. The manufacturing plant is basically represented by a kiln and a plot of land as a farmyard; the area where these elements are concentrated is commonly named “Chircal”. Craft brickers usually use kilns of direct fire and upward firing for cooking. The main fuel used in the manufacture of bricks is coal, followed by natural gas and diesel. The present work aims to characterize air quality, taking into account the massive growth of the brick manufacturing activity in the rural locality of Patio Bonito, Nemocón, Colombia, specifically assessing the particulate matter PM10, which is one of the most critical air pollutant due to its impact on health of its inhabitants and on the local environment. The year 2013 was selected for the analysis, because the highest PM10 concentrations of the last five years that happened in that year, according to historical data from the environmental authority of Cundinamarca region. For assessing the air quality in Patio Bonito, a Gaussian air quality model named URBAIR, developed by the University of Aveiro, was applied. For an adequate operation of this model, it was necessary to collect input data as emission sources and meteorological data. The modeling periods were August 8th, November 20th and 24th 2013, when daily averaged with concentrations above 100 µg/m3, limit regulated by Colombian legislation were registered. Moreover, two improvement scenarios were proposed. The first considered the operation of “Colmena” kilns with an emission control system. The second implied Hoffman and Tunnel kilns, because those showed the lowest PM10 emissions. Results allowed to conclude that those improvement measures can reduce the PM10 contribution to air pollution levels. Resumen: La fabricación del ladrillo genera un efecto directo en la calidad del aire afectando la salud de las comunidades circundantes de este tipo de industria. En el municipio colombiano de Nemocón, en la localidad rural de Patio Bonito, la mayoría de las pequeñas ladrilleras utilizan técnicas artesanales para la fabricación de diferentes tipos de ladrillos. La planta de fabricación está básicamente representada por un horno y una parcela de tierra como un patio; el área donde se concentran estos elementos se denomina comúnmente ""Chircal"". Los trabajadores artesanales generalmente usan hornos de fuego directo y fuego ascendente para cocinar. El principal combustible utilizado en la fabricación de ladrillos es el carbón, seguido del gas natural y el diesel. El presente trabajo tiene como objetivo caracterizar la calidad del aire, teniendo en cuenta el crecimiento masivo de la actividad de fabricación de ladrillos en la localidad rural de Patio Bonito, Nemocón, Colombia, evaluando específicamente el material particulado PM10, que es uno de los contaminantes atmosféricos más críticos debido a su impacto en la salud de sus habitantes y en el entorno local. El año 2013 fue seleccionado para el análisis, debido a las mayores concentraciones de PM10 de los últimos cinco años que ocurrieron en ese año, según datos históricos de la autoridad ambiental de la región de Cundinamarca. Para evaluar la calidad del aire en Patio Bonito, se aplicó un modelo Gaussiano de calidad del aire denominado URBAIR, desarrollado por la Universidad de Aveiro. Para un funcionamiento adecuado de este modelo, fue necesario recopilar datos de entrada como fuentes de emisión y datos meteorológicos. Los periodos de modelación fueron el 8 de agosto, el 20 y el 24 de noviembre de 2013, cuando se registró un promedio diario con concentraciones superiores a 100 ?g / m3, límite regulado por la legislación colombiana. Además, se propusieron dos escenarios de mejora. El primero consideró la operación de hornos ""Colmena"" con un sistema de control de emisiones. El segundo implicaba los hornos Hoffman y Tunnel, porque aquellos mostraban las emisiones más bajas de PM10. Los resultados permitieron concluir que estas medidas de mejora pueden reducir la contribución de PM10 a los niveles de contaminación del aire.

Abstract: The success of machine learning algorithms depends on the representation of the data used. Specific domain knowledge can be used to design good representations. However, these representations are limited to a specific problem or task, and to the amount of available labeled data. Another approach is to automatically learn generic priors that can be used in different tasks and context. In the field of natural language processing, recent work has been done in obtaining such priors by learning useful vector representation of words from unlabeled data. The representations can then be used to improve existing natural language processing systems. These word vectors are obtained using special neural network architectures trained on billions of tokens. However, most of these models are learned and evaluated on English language corpora. In this work, Word2vec, a recent neural network based toolkit for learning word representations is used on German language data. The goal is to evaluate the learned representations of words in different language processing and information retrieval tasks. In particular, a semantic-syntactic evaluation set is constructed for the German language. In addition to that, the learned word vector representations are used as features for a classifier of German language business documents. The learned features outperformed existing handcrafted features and performed similar to other state-of-the-art approaches. Resumen: El éxito de los algoritmos de aprendizaje automático depende de la representación de los datos utilizados. conocimiento de dominio específico se puede utilizar para diseñar buenas representaciones. SIN EMBARGO, representaciones de síntesis se limitan a un problema o tarea específica, y que la cantidad de datos disponibles etiquetados. Otro enfoque es aprender automáticamente priores genéricos hizo kann utilizado en diferentes tareas y el contexto. En el campo del procesamiento del lenguaje natural, los trabajos recientes se ha hecho en la obtención de distribuciones previas examinados por el aprendizaje de la representación vector útil de las palabras de datos no etiquetados. Las representaciones a continuación, se pueden utilizar para mejorar el sistema de procesamiento de lenguaje natural existente. Estos vectores de palabras se obtienen utilizando arquitecturas de redes neuronales especiales entrenados en miles de millones de fichas. Sin embargo la mayoría de los modelos de síntesis se aprenden y se evalúa el corpus idioma Inglés. En este trabajo, Word2vec, un conjunto de herramientas basadas red neuronal reciente para el aprendizaje de representación de palabra se utiliza en los datos de idioma alemán. El objetivo es evaluar las representaciones aprendido de palabras en diferentes tareas de procesamiento del lenguaje y la recuperación de información. En particular, una evaluación semántico-sintáctica conjunto se construye para el idioma alemán. Además de eso, las representaciones vectoriales de palabras aprendidas se utilizan como características para un clasificador de documentos comerciales idioma alemán. Las características aprendidas superaron características artesanales existentes y funcionando de modo similar a otros enfoques del estado de la técnica.

Se presenta una metodología para aplicar calidad de servicio sobre redes ópticas de transporte (OTN), se realizara un análisis de conceptos básicos de las redes OTN y algunas de sus funcionalidades que permiten calidad de servicio en entorno de protección para redes IP. También se presentan simulaciones en la conmutación de paquetes fotónicos y la conmutación de longitud de onda para proporcionar calidad de servicio.