Abstract: The synthesis of nanostructures has attracted much interest due to their advanced properties compared to their bulk material. Zinc Oxide (ZnO) has gained substantial interest in the research community due to its large exciton binding energy (60 meV). ZnO is a semiconductor with several favorable properties like a good transparency in the visible region, and a wide band gap of 3.37 eV. Those properties are already used in many emerging applications as chemical sensors, nano laser, and transistors. Due to its wurtzite crystal structure ZnO readily grows to elongated nanoparticles such as nanorods or nanowires. Elongated nanostructures are promising due to precise electron transport in one direction. Special attention has been devoted to the realization of transparent conductive oxides (TCOs) for optoelectronic devices such as solar cells and displays. The first part of this thesis is dedicated to the comparison of the synthesis of ZnO nanorods in a three-neck flask to solvothermal method. In order to investigate the effects of various reaction parameters on the structural and optical properties in the solvothermal method, different temperatures, volumes of solvent and reaction time were selected. The second part addresses the tailoring of the microstructure and electrical properties of ZnO nanorods modified with aluminum and indium, respectively. Finally, doped ZnO nanorods thin films prepared on glass substrate by drop casting method were investigated. This thesis provides first experimental work for transparent conductive zinc oxide prepared by solvothermal synthesis and highlights possibilities and boundaries for introduction of dopants in ZnO nanorods. Resumen: La síntesis de nanoestructuras ha atraído mucho interés debido a sus excelentes propiedades en comparación con su material a granel. El óxido de zinc (ZnO) ha ganado un interés sustancial en la comunidad de investigación debido a su gran energía de ligadura (60 meV). ZnO es un semiconductor con varias propiedades favorables, así como una buena transparencia en la región visible, y una amplia brecha de banda de 3,37 eV. Esas propiedades ya se utilizan en muchas aplicaciones emergentes como sensores químicos, nano láser y transistores. Debido a su estructura de cristal de wurtzita, ZnO se desarrolla fácilmente a nanopartículas alargadas como nanorods o nanocables. Las nanoestructuras alargadas son prometedoras debido al transporte preciso de electrones en una dirección. Se ha dedicado especial atención a la realización de óxidos conductores transparentes (TCO) para dispositivos optoelectrónicos como células solares y pantallas. La primera parte de esta tesis está dedicada a la comparación de la síntesis de nanorods de ZnO en un matraz de tres bocas versus un método solvotermal. Con el fin de investigar los efectos de diversos parámetros de reacción sobre las propiedades estructurales y ópticas en el método solvotermal, se seleccionaron diferentes temperaturas, volúmenes de disolvente y tiempo de reacción. La segunda parte aborda la adaptación de la microestructura y las propiedades eléctricas de los nanorods de ZnO modificadas con aluminio e indio, respectivamente. Finalmente, se investigaron las películas finas de nanorods modificadas y preparadas sobre sustrato de vidrio mediante el método de moldeo a gotas. Esta tesis proporciona el primer trabajo experimental para óxido de zinc como conductor transparente preparado por síntesis solvotérmica y resalta las posibilidades y los límites para la introducción de dopantes en nanorods de ZnO.

The need of understanding the relationship between the physical habitat and ecology in the fluvial systems has become a major issue due to an increasing environmental conciousness but also because of the normativity which demand the achievement of the good status of the water bodies and its ecosystems. Exactly this requirement is prescribed by the European Water Framework Directive (WFD) which have included the hydromorphology as an important aspect of evaluation due to the influence that it has on the ecology of a river system. The hydromorphology gets relevance because it study the system as a whole, involving the interactions between ecology, hydrology and fluvial geomorphology. As a response to the WFD each country of the European Union has developed a method for guaranteeing the compliance of the normativity. Elements of such methods and of international literature are collected for the development of a methodology that fulfill the gaps of the current Colombian water normativity and support the decision making in the environmental planning and impact assessment. This guide for the river morphological restoration in Colombia is a complete hydromorphological analysis of a selected river which main purpose is to make an approach to the general aspects of the river in the macro scale, followed by an assessment in the meso scale in which the river is segmented, classified and the hydromorphological conditions are scored; finally, a simulation is performed for a critical reach, called in this work the “bottle neck” reach. The simulation consists in a hydrodynamics model (or hydromorphodynamics model as optional), its results of depth, velocity and substrate in combination with the preferences of a fish indicator species, are computed in the software CASiMiR and give the habitat suitability in the study area for the simulated conditions. The application of such methodology is applied in a mountainous river reach downstream the Punt da Gall dam in Switzerland for which the hydromorphological aspects in the macro and meso scale are assessed and in the micro scale the habitat distribution of fish indicator species are calculated. The present work is an attempt to apply the habitat simulation as a tool for determining hydromorphological quality, for river restoration activities and for determining minimum habitat conditions when the discharge is regulated. Future investigations include the application in a Colombian river for which the collection of biological data still is a challenge.

This research is focused on obtaining an important reduction in greenhouse gas (GHG) emissions resulting from the use of fossil fuels by increasing the efficiency of pre-combustion carbon capture. It examines a new, low-risk, approach that uses conventional water gas shift reactors and acid gas removal technology in a unusual arrangement, within an Integrated Gasification Combined Cycle power plant (IGCC). Timmins (2010) proposed a flowsheet of this nature and it is this flowsheet that is used as the starting point for this research project. Process simulation in UniSim Design R390 is conducted  to validate the viability of such  a flowsheet and to investigate optimal plant configuration. The modelling output is compared to US DOE baseline studies for competing technologies (2010).The physical solvent, Selexol, is used for cardon dioxide (CO2) absorption as recommended by researchers as the most energy efficient amongst the range of physical and chemical solvents investigated. There are mainly two thermodynamic models required to meet all of the needs of this complex process. Most of the process is modelled with the Peng-Robinson equation of state but the Selexol absorber and desorber is modelled using the non-random-two-liquid model  (NRTL) for the liquid phase and the ideal gas law for the vapour phase. A beseline flowsheet model is successfully modelled that could be attached to an IGCC plant to enable it to continue producing electric power whilst capturing 90% of the carbon derived from the fuel. The model is used for process development, and for energy efficiency evaluation. Every major item of capital equipment has been included, modelled and sized to produce a cost analysis and additionallly, the model output was used for a preliminary life cycle analysis (LCA). From the results produced in this study, the proposed process appears to be a feasible, energy-efficient, alternative technology for incorporating carbon capture within an IGCC flowsheet.

Ship-source oil spills are amongst the major sources of oil affecting coastal areas. An end-to-end marine oil spill analysis may provide a model to better allocate response resources or prepare contingency plans for highly vulnerable zones. A consequence assessment, a key aspect of this type of analysis which considers economic, social and environmental aspects of a geographic area, is presented in this study as a GIS index tool, which can be applied in the context of Atlantic Canada. A theoretical framework and conceptual model is developed based on a literature review of oil spill state-of-the-art analysis using Exploratory Network Analysis; and tested on a realistic case study (Halifax Harbour, NS). The novel approach for reviewing the literature provided sound criteria for the conceptual model, which fits the end-to-end marine oil spill analysis, segregating elements regarding exposure and oil behaviour. Furthermore, oil spill management indicators were tailored using expertise from Atlantic Canada’s oil spill responders, and many gaps were identified to potentially refine the model later. Finally, this model considers the range of aspects that influence the consequences of a ship-based oil spill, using readily available information and considering relevant stakeholder’s interests.

Insects are essential for the functioning of ecosystems, delivering important ecological functions as nutrient recycling, pest control, pollination, and seed dispersal. Biodiversity increases the multi-functionality and resilience of ecosystems around the world, a valuable effect considering that global change is likely to have an impact on ecosystems globally. In the process of urbanisation, ecosystems are modified and plant and animal communities segregated, affecting biodiversity and thus jeopardising ecosystems in a global scale. Different insect taxa play distinct ecological roles, so assessing how environmental factors associated with urbanisation affect them is relevant for the conservation of biological diversity of cities. The main objective of this research project was to investigate how insect communities are affected by urbanisation, using an integrated multi-taxa and multiscale approach. The research project is divided in two fundamental questions: 1) Are insect communities affected by coarse or fine scale environmental filters? and 2) Are insect´s foraging abilities affected by environmental modification? To address the first question, I sampled four insect taxa (Coleoptera, Diptera, Hemiptera and Hymenoptera) in 19 sites with three levels of environmental modification, and multiple environmental variables associated with urbanisation. For the second question, I used focal plants to sample floral visitors in 19 sites with varying levels of environmental modification, recording the time taken for the focal plant to be discovered by an insect, and the number of insects after 48 hours. My results show that coarse environmental filters affect Hemiptera communities but do not seem to affect Coleoptera, Diptera, or Hymenoptera communities. Fine environmental filters such as proportion of native plants with flowers, site area, and proportion of green space are associated with species richness of coleopteran, dipteran and hymenopteran communities. Floral discoverability was not associated with environmental modification but the number of insects was higher in sites with higher environmental modification. Native floral resources are important for the maintenance of urban biodiversity, thus native plants should be used in urban green. Low species richness of hymenopterans and coleopterans in more urbanised sites indicates the susceptibility of these groups to urbanisation, reflecting what others studies have found in urban contexts worldwide. Environmental modification affects insects’ ability to discover and use floral resources. Where conservation initiatives use floral resource plantings to support biodiversity, environmental modification must be considered, to ensure that target taxa are able to reach the novel resources.

The flood event is a problem that may affect drastically any settlement and can bring dramatic consequences, especially when it is not considered as one of the urbanization dynamics. It is important to reduce floods with measures that can be as simple as self‐preparedness, as well as an integrated long‐term plan. Hence, it is essential to avoid loss of lives taking preventive measures and building a resilience perspective into the population. The present document describes the main concepts that should be taken into consideration to understand the flood risk. Consequently, analyses the current flood risk in Bogota, Colombia and seeks to determine the zones where vulnerable settlements overlay flood hazard areas. Finally, it is examined how flood risk management can be targeted to reduce the risk level and how can the design solutions help to prevent and manage the flood problem within the city. Resumen La inundación es un problema que puede afectar drásticamente cualquier asentamiento y puede traer severas consecuencias, especialmente cuando no se considera como una de las dinámicas de la urbanización. Es importante reducir las inundaciones con medidas que pueden ser tan simples como el autoaprendizaje, así como un plan integrado a largo plazo. Por lo tanto, es esencial evitar la pérdida de vidas tomando medidas preventivas y construyendo una perspectiva de resiliencia en la población. El presente documento describe los conceptos principales que deben tomarse en consideración para comprender el riesgo de inundación. En consecuencia, analiza el riesgo de inundación actual en Bogotá, Colombia y busca determinar las zonas donde los asentamientos vulnerables se sobreponen a las áreas en peligro de inundación. Finalmente, se examina cómo la gestión del riesgo de inundación puede orientarse para reducir sus niveles y cómo las soluciones de diseño pueden ayudar a prevenir y gestionar el problema de inundación dentro de la ciudad.

"Study on the kinetic isotope effect (KIE) in alcohol dehydrogenase from thermophilic Bacillus stearothermophilus. The enzyme was expressed and purified in order to measure steady state rate constants (𝑘𝑐𝑎𝑡) for the catalysed reaction of wild type and isotopically labelled enzyme. Five different substrates were employed: 2-Butanol, ethanol, cyclopentanol, acetone and acetaldehyde. KIE was determined using non-competitive method. Rate constants (𝑘𝑐𝑎𝑡) were measured via UV spectroscopy by monitoring the linear increase or decrease of the absorbance of the cofactor NADH as a function of time. Estudio del efecto isotópico cinético (EIC) en alcohol deshidrogenasa termofílica de Bacillus stearothermophilus. La enzima se expresó y purificó para luego medir la constante de velocidad de reacción (𝑘𝑐𝑎𝑡) para la reacción catalizada de la enzima con y sin marcación isotópica. Cinco diferentes substratos se emplearon:2-Butanol, etanol, ciclopentanol, acetona y acetaldehído. EIC se determinó usando el método no competitivo. Las constantes de velocidad de reacción (𝑘𝑐𝑎𝑡) fueron determinadas por medio de espectroscopia-UV monitoreando el incremento o disminución lineal de la absorbancia del cofactor NADH en función del tiempo."

Although the last decades have seen an advance in quality and empowerment for women, there are still numerous challenges to be addressed. Among them, and particularly pressing in cities, are issues of gender-based violence, including sexual harassment in public spaces. Despite the numerous effects street harassment has on women, and the high incidence of it in different countries, this issue has not been broadly studied, and even less so in Global South cities. In this scenario, this study aims to comprehend how women in Bogotá experience sexual harassment in public spaces, specifically focusing on public transport and including vehicles, stations, stops and walking routes to and from their origins or destinations. Focusing on this objective, this study made use of a mixed-method approach, including an online self-completing questionnaire, as well as in-depth semi-structured interviews. The data gathered showed that sexual harassment in public transport – and public space – is widespread in Bogotá, and intersections with age and class play a very important role. Additionally, episodes of sexual harassment are widely underreported, and there is a general perception that reporting is useless, which is supported by accounts of women who have tried to report an incident and have faced several difficulties. Finally, policies proposed so far in Bogotá have been unsuccessful in reducing sexual harassment in public transport and, in many cases, do not tackle the problem. Consequently, a comprehensive set of policies aimed at preventing and reducing sexual harassment in different spaces associated with public transport must be put in place. Aunque en las últimas décadas se ha visto un avance en cuanto a la igualdad y el empoderamiento de las mujeres, aún hay muchos retos por abordar en estos temas. Entre ellos, y especialmente relevantes en las ciudades, están los problemas de violencia de género, incluyendo el acoso sexual en espacios públicos. A pesar de los varios efectos que tiene el acoso callejero en las mujeres, y la alta incidencia de este en distintos países, el tema no se ha estudiado a profundidad, y aún menos en ciudades del mundo en desarrollo. En este escenario, este estudio busca comprender cómo las mujeres en Bogotá experimentan el acoso sexual en los espacios públicos, específicamente enfocándose en el transporte público e incluyendo vehículos, estaciones, paraderos y rutas a pie desde y hacia los orígenes y destinos. Siguiendo este objetivo, el estudio utiliza un enfoque de métodos mixtos, incluyendo una encuesta en línea, así como entrevistas semi-estructuradas en profundidad. La información compilada muestra que el acoso sexual en el transporte público – y el espacio público – es generalizado en Bogotá, y las intersecciones con la edad y clase tienen un rol muy importante. Adicionalmente, los episodios de acoso sexual están ampliamente subreportados, y hay una percepción general de que reportar es inútil, lo cual se refleja en las historias de mujeres que han intentado reportar un incidente y se han enfrentado a múltiples dificultades. Finalmente, las políticas propuestas hasta el momento en Bogotá no han tenido éxito en cuanto a reducir el acoso sexual en el transporte público y, en muchas ocasiones, no abordan el problema. Por lo tanto, es necesario implementar un conjunto completo de políticas que se enfoquen en prevenir y reducir el acoso sexual en los diferentes espacios asociados con el transporte público.

This research explores the new meanings of fatherhood in The Netherlands, how men address their role as active fathers and in the household, considering their responsibilities at work and the influence of traditional gender roles. This work investigates how men are dealing with fatherhood and balancing their work and family lives, the possible consequences in their careers when they are more involved with their children and the household, and how the main discourses about the traditional gender roles still affect the development of an open, public, active and proud fatherhood. This research focuses on fathers and their daily interactions and stories while attempting to balance work and family life, where this new active fatherhood is challenged. Fathering narratives and stories are explored and analyzed in contrast to the main discourse about fatherhood, the traditional gender roles that still affect these processes, and policies and norms in The Netherlands, regarding flexible work and family-work balance. Esta investigación explora los nuevos significados de la paternidad en los Países Bajos, cómo los padres manejan su rol como padres activos y en el hogar, considerando sus responsabilidades en el trabajo y la influencia de los roles de género tradicionales. Este trabajo investiga cómo los hombres están lidiando con su paternidad y al mismo tiempo balanceando el trabajo con la vida familiar, las consecuencias en su carrera profesional cuando están más involucrados en el hogar y con sus hijos, y cómo los discursos tradicionales aún afectan el desarrollo de una paternidad abierta, pública, activa y orgullosa. Asimismo, la presente investigación se enfoca en las interacciones diarias e historias de los padres holandeses, mientras intentan balancear la vida familiar con el trabajo, en donde esta nueva paternidad activa es retada. Las narrativas e historias sobre paternidad son exploradas y analizadas a la luz del discurso tradicional y general sobre paternidad, los roles de género tradicionales que aún afectan estos procesos, y las políticas y normas en los Países Bajos, en cuanto al trabajo flexible y el balance entre vida laboral y la vida personal.

En esta disertación examino las formas en que un grupo de profesionales usa, diseña y entiende mapas digitales usados en proyectos participativos en Madrid, España. Argumento que estos Profesionales de la Participación Pública (PPP) llevan a cabo su experticia al generar y organizar sus relaciones con otros actores y objetos de forma que están, simultáneamente, resaltando su autoridad para generar participación, y distribuyendo su autoridad en el proceso. Mi análisis se centra en sus relaciones con los proyectos comunitarios que están mapeando, con profesionales que trabajan similarmente en el diseño de mapas participativos, y con el mapa digital como tal. Concluyo sugiriendo que una aproximación a la experticia que sea etnográfica y centrada en el objeto nos permite desestabilizar nuestras nociones de participación, el rol de las tecnologías digitales, y nuestro entendimiento de lo que es una perspectiva crítica.