APRÈN. Portal de la producció docent del professorat de la UPC

This thesis aims to develop a study with regards to the exploration of the lunar surface through the resources produced by space weathering. Space weathering events shall be discussed, in terms of how the physical and chemical characteristics of the lunar regolith is affected. Through hydrogen reduction, the products formed from space weathering interactions shall be produced within the lunar simulants JSC-1 and FJS-3. This is followed up with characterising the processed samples via a Scanned Electron Microscope (SEM) to confirm the formation of npFe0 and SMFe – a product of space weathering. Thereafter, a preliminary quantification of the presence of npFe0 and SMFe within one of the samples is obtained through a Mossbauer analysis, this is to provide the basis for ¨ future more accurate quantification of npFe0 and SMFe to be created. In addition to these experiments, an analysis on the samples reflectance within the ultraviolet (UV) region of the electromagnetic spectrum is conducted – finding a preliminary correlation between decreasing reddening gradient and increasing reduction temperatures (the temperature in which the sample was reduced at). Finally, an equation was fitted to this correlation in order to mathematically describe the relationship between the sample's reflectance spectra and reduction temperature (the duration of this reduction was first conducted for 2 hours and then 4 hours). This preliminary mathematical model allows for interpolation of the reddening gradient – a characteristic dependent on the products of space weathering, for both the lunar simulants JSC-1 and FJS-3, when a specific reduction temperature is provided. Ultimately providing the basis for a mathematical model to determine the quantities of npFe0 and SMFe within the lunar regolith by viewing its corresponding UV reflectance spectra.

The discovery of lunar ice in 1998 opened a whole variety of new perspectives for in-situ resource utilization of water on the Moon. However, more recent studies suggest that the amount of lunar ice is scarce. On the other hand, almost every single space agency and a substantial number of private initiatives advocate for a human return to our natural satellite and establishement of a permanent outpost. In this work, a feasibility study of using water from an asteroidal source in lunar orbit will be carried out, including the astrodynamics of asteroid capture and orbital insertion, exploitation approach and a techno-economic analysis of asteroidal water utilization for lunar development. First, selecting and analysing the best candidate asteroid for the mission (asteroid 2010DL). Subsequently, all the technical parameters of the mission will be analysed in order to conclude that due to the current propulsion systems, the impulse times required to accelerate or decelerate the mass of asteroid 2010DL are much longer than the natural flight time that the manoeuvres would have, so it is concluded that with the current propul-sion systems it is not possible to decelerate an asteroid of 19 metres in diameter of type C fast enough on its entry into the Earth's capture orbit, It then proposes a solution that satisfies both the technical and economic constraints, which is to extract the water directly in the asteroid's own orbit and send tanks of 9500 litres of water directly from the perigee and apogee of the asteroid's orbit to a moon distant retrograde orbit.

This book stems from the work carried out by students during a single semester of the course Space Resources and Planetary Settlements of the Master degree in Space and Aeronautical Engineering of the Universitat Politècnica de Catalunya. It aims to provide a scientific and engineering view on the Moon as a place where humans can live and work for the benefit of humanity, sustainably. After a review of the Moon's environmental conditions and natural resources, important issues such as energy, life support systems and the analysis of robotic vs. human activities are discussed in detail. Travel to and from the Moon is also considered, including the lessons learned about transportation strategies on continuous round trips to and from the International Space Station during the early 21st century. Finally, a set of different activities that can be carried out and, in the authors' opinion, fully justify the return to our natural satellite, are treated in some detail.tail. Travel to and from the Moon is also considered, including the lessons learned about transportation strategies on continuous round trips to and from the International Space Station during the early 21st century. Finally, a set of different activities that can be carried out and, in the authors' opinion, fully justify the return to our natural satellite, are treated in some detail.

This document contains a sustainability study of a permanent Martian outpost. It involves a preliminary introduction to the exploration of Mars and concepts related to sustainability such as sustainable development, carrying capacity or impact, as well as an overview of previous studies regarding human exploration of Mars. The methodology proposed to carry out the sustainability study is a brand-new approach to the analysis of space exploration missions that focus on the impact of the mission elements regarding the Earth, the Outer Space, and Mars itself. It also provides a framework that will allow to extend the study to location-related carrying capacity assessment, and In Situ Resource Utilization and Environmental Control and Life Support Systems' circularity. After a discussion of the results obtained from the quantitative analysis performed, an extensive proposal of future work is provided, as well as orientation on what to expect from future missions to the red planet.

High Calcium Fly Ashes are reactive materials that often do not meet the limits of the standards. Therefore, most of the quantity produced annually in the world, due to lignite burning, remains unexploited and charges the environment. Actually, a low percentage of the materials is absorbed at a permanent basis from the cement industry and huge amounts are rejected or used for reclamation of mining areas. However, investigation on these materials has shown which are the weak points and how they could be overcome by using advances in materials technology.

El incremento de la concentración de CO2 en la atmósfera es atribuido al elevado consumo de combustibles fósiles para la generación de energía. Las tecnologías de carbonatación mineral son necesarias para prevenir que el calentamiento global supere los 2ºC para el final de este siglo, propuesto en el Paris Summit 2015. La carbonatación de peridotitas y serpentinas puede ser acelerada a tal punto de ser considerado como un significante método para capturar CO2. Se ha probado que estas rocas tienen una alta afinación en almacenar seguramente el CO2. El objetivo de esta tesina es el estudio de viabilidad de la reacción de carbonatación en peridotitas y serpentinas. Las condiciones de este estudio fueron definidas según los resultados que dieron la mayor captura de CO2 con el menor coste energético según el estudio de Kelemen and Matter, 2008. Las muestras fueron molidas y expuestas a una interacción de gas y sólido a 185ºC y una presión de 1 bar de CO2 más la presión atmosférica por dos horas. Bajo estas condiciones, todas las muestras presentaron un aumento en la proporción de carbonatos y fue claramente determinado utilizando los siguientes métodos: Difracción de polvo cristalino XRD, FTIR de transmisión y de-carbonatación por ácido. Los resultados de FTIR revelaron claramente los cambios causados por la reacción de carbonatación, dando la respuesta más precisa en cuanto a formación de carbonatos. Estos resultados también revelaron de forma cualitativa el incremento de proporción de magnesita en todas las muestras. Los resultados de de-carbonatación por ácido revelaron que el máximo de captura de CO2 obtenido en todas las muestras es del 4%. Sin embargo, ninguno de los métodos pudo dar una cuantitativa tasa de carbonatación. Las muestras de peridotitas en todos los métodos mostraron una clara tendencia de carbonatación. La comparación entre la composición y la tasa de carbonatación para las muestras de peridotitas revela la inversa relación del Mg# y Ca# en la captura de CO2. A grandes valores de Mg# mejor su tasa de carbonatación. La muestra de Dunita (LT-1) presenta la mayor tasa de carbonatación entre las muestras de peridotitas, la cual es la muestra que tiene el mayor Mg# y el menor Ca#. Los resultados de XRD revelaron que todas las muestras de peridotitas han formado carbonato de calcio. Las serpentinas mostraron resultados complejos los cuales pueden ser atribuidos a su complejidad mineral y composicional.

L'ús de materials fotocatalítics en superfícies construïdes resulta atractiu pot ajudar molt significativament a la millora de la qualitat de l'aire en les ciutats. Amb la finalitat d'avançar en la consecució d'una aplicació fotocatalítica eficient i duradora, es proposa la investigació al voltant de la impressió 3D de pastes de nanomaterials de TiO2 per tal de proposar posprocesos adreçats a la millora de les seves propietats mecàniques i funcionals.

The Moon is an excellent place to make astronomical observations and, furthermore, a great platform to study and gain a better understanding of our own planet and the Universe. However a thin layer of dust covers the lunar surface. It consists of electrostatically charged grains of less than 20 m in diameter. Due to their tiny size, charge and low gravity, they remain suspended from 10 cm to high altitudes (100 km), and would eventually deposit onto solar panels and optical elements causing the degradation of their performance. To overcome this problematics, some studies have proposed the use of a quasi- transparent electromagnetic shield to facilitate the cleaning of the electrostatically charged dust from surfaces, therefore preventing its accumulation, optimizing their efficiency and extending the lifetime of the instruments. These are the so- called Electrodynamic Screens (EDS) and consist of a series of parallel electrodes equally spaced and connected to an alternating current source that generates an electromagnetic wave, in movement, thus repelling the particles. The aim of this project is to find the best configuration of the EDS (width of the electrodes, distance between them and so on) particles in order to achieve the maximum efficiency in removing dust. For this, the results of experiments conducted to date on the Cleaning Factor (CF) or Dust Removal Efficiency (DRE) will be analyzed to determine which parameters and to what extent they affect the efficiency of dust removal in a EDS. In addition to this, the best location on the lunar surface for solar panels and telescopes according to illumination conditions and minimization of dust effects will be evaluated.

Siendo la belita β-Ca2SiO4 uno de los principales componentes del clinker para la fabricación del cemento portland ordinario, en el presente trabajo, se analiza los primeros estadios de la hidratación del silicato dicálcico C2S y la formación del C-S-H mediante el uso de Fourier Transform Infrared Attenuated Total Reflectance (FTIR/ATR) que es una potente técnica para estudiar las etapas iniciales de la hidratación del cemento, con el fin de entender los cambios que ocurren desde el momento de iniciar la mezcla hasta alrededor del minuto 90, llevando el control aproximadamente cada 2 minutos con relaciones diferentes de agua-cemento w/c (0.30, 0.50 y 0.70). Se encontró que, en general, los procesos ocurren de manera similar en las 3 muestras llegando a alcanzar la formación del C-S-H en un tiempo que rodea los 20 min, lo cual significa que posee una velocidad de hidratación rápida, bastante superior a la que se ve en presencia de la alita Ca3SiO5 y los otros componentes mayoritarios del clinker, como cuando se examina en el caso del cemento. Se observó, además que, a través de futuros trabajos, podría existir la posibilidad de tener un control de la cinética de hidratación del C2S en función del C3S cuando ambos compuestos reaccionan a la vez, logrando así mejorar la formación de clinker y por ende la fabricación del cemento.

La grave problemática de contaminación atmosférica que presentan las grandes urbes acarrea la aparición de dolencias respiratorias y alergias. La aplicación de materiales fotocatalíticos, los cuales tienen la capacidad de descomponerlos u transformarlos en compuestos no agresivos, podría resolver la problemática de la calidad del aire. Su uso en materiales de base cementícia resulta sumamente atractiva, tanto por el elevado uso de estos materiales en las ciudades como por resultar inerte al dióxido de titanio, el fotocatalizador de uso más extendido. Actualmente estas aplicaciones presentan varios problemas aun sin solucionar; se desconoce su distribución en aplicaciones en masa, presentan descensos en la eficiencia por acumulación de contaminantes en superficie, no se consigue eliminar los compuestos en superficie con tratamientos no agresivos y las aplicaciones superficiales tienen una durabilidad reducida. Con la finalidad de comprender el comportamiento del conjunto principalmente en el problema de distribución en las aplicaciones en masa, se realiza un estudio de análisis superficial. Para ello, se fabrican dos muestras, una de mortero sin fotocatalizador y otro con 5% del peso de cemento de dióxido de titanio. Las muestras se someten a un análisis de compuestos en superficie mediante espectrometría de fotoelectrones de rayos X. tras analizar la muestra con TiO2, esta se somete a pulido por ataque iónico con argón y se vuelve a analizar. El estudio arroja comportamientos desconocidos hasta ahora que pueden favorecer mejoras en la fabricación y mantenimiento de los pavimentos fotocatalíticos con TiO2 en materiales de base cementícia.

[ANGLÈS] With the increasing carbon dioxide emission in the atmosphere, there has been an interesting interest in CCS (Carbon Capture and Storage). Mineral carbonation was considered as a better option for storage atmospheric CO2 to slow climate change down. It's a better method for storing CO2 without re-releasing CO2 in the atmosphere. The reaction rate of carbonation is too slow to be used at industrial scale under natural conditions containing ambient temperature and pressure. Several pilots were done to study and observer the reaction rate of carbonation with various conditions. In this study, we used the ultramafic igneous rock (such as pyroxene and dunite) containing amounts of magnesium and calcium which could react with atmospheric CO2 to form stable carbonates into geological formations. We did the gas-solid carbonation experiment without water-dissolution that was used by amounts of researches in the worldwide to observer change rate of carbonate produced under various CO2 pressures. By understanding of the previous researches and papers, we knew mineral carbonation in situ has higher carbonation rate relative to rate at 25OC in atoms CO2 saturated water at 1 bar. We used X-ray Diffraction to understand compounds of the sample in the depth and X-ray Photoelectron Spectroscopy to investigate carbonates produced change in the surface of the samples during the mineral carbonation process. The main aim of this thesis is to evaluate characterization of the sample (including Pyroxene and Dunite) and mineral carbonation procedure in various pressures at 185 OC. The quantitative ratio [CO3 2-]/C for each sample in different reaction conditions has been determined from an analysis of the C 1s spectra of XPS. The XPS observations showed the same behaviors for the two types of ultramafic igneous rock: the ratio of carbonate to carbon in the surface of the samples at 5 bars is higher than at 1 bar. In addition the ratio of carbonates to carbon after the heating treatment decreases a little, and then the value would increase after the carbonation procedure. That means the carbonates were removed by the heating treatment.

In the casting industries, sand is typically reused through the production cycles. Since sand for itself do not have the necessary properties to this process, it's necessary to introduce binders to force the sand grains to hold their shape during the casting process. When the casting sand cannot be reused it considered a residue, and it is formally called waste foundry sand. Worldwide, China is the larger producer with 35.3 million tonnes (in 2009), followed by North America with 9.6 million tonnes per year and finally Europe with 12 million tonnes. In Europe, this value is 75% of sand waste. Europe as a producer, has Germany as the largest producer of foundry casting. In 2006 total casting production was 5.5 million tonnes divided between ferrous (82.3%) and non-ferrous foundries (17.7%). At present Germany is the 6th largest producer of cast components. Available in large quantities, and considered an inert residue, waste foundry sand presents good characteristics to adsorption processes. The adsorption of metals by waste foundry sand is a key parameter to be considered in the application of passive barriers. Special attention was given to Antimony and Germanium. Antimony, is commonly used in alloys, batteries, cable sheathing, flame-proofing compounds, paints, and glass, among others. Germanium is a very important semiconductor material, doped with arsenic, or gallium, it is used as a transistor element in electronic applications, as PET catalysts in the plastic bottling industry, in infrared spectroscopes, glass and in fiber optics. In this work, sophisticated nanoscale techniques were used to identify and characterise this material. Adsorption studies were carried out with positive results and the time evolution was analysed. In this dissertation its proved that sand grains were covered partially by a clay layer, and that germanium is well adsorbed by waste foundry sand. In the first 5 minutes of reaction an adsorption of Ge of 10% is observed, followed by an increase up to 22% at 90 minutes of reaction. It is also shown that equilibrium is reached after 30 minutes of reaction. It is possible to conclude that there is an increase in the efficiency of adsorption with time, and it stabilizes at a level of 22%.

La investigación de la adición de nanopartículas a materiales cementosos es un área en creciente desarrollo dentro del campo de la industria de la construcción en los últimos años, pues su uso mejora importantes propiedades del hormigón, como resistencia y durabilidad. Las primeras aplicaciones comerciales están comenzando a lanzarse al mercado. El tipo de adición objeto de este estudio es la nanosílice. La adición de nanosílice al hormigón mejora sus propiedades tanto a nivel de resistencia mecánica como a nivel de resistencia a degradación, mejorando la durabilidad de las estructuras de hormigón. La nanosílice, dado su tamaño, actúa como filler de gran efectividad, reduciendo el tamaño de poros y mejorando de esta manera las propiedades mecánicas. También actúa como adición activa, ya que reacciona para formar gel C-SH y activa el proceso de hidratación del cemento. También fomenta el proceso de hidratación participando en las reacciones de hidratación de los materiales con propiedades puzolánicas. Además, la adición de nanosílice fomenta la precipitación de gel C-S-H con ratio Ca/Si menor. Esta propiedad mejora la permeabilidad y el comportamiento de estos materiales ante la descalcificación y disolución de la matriz ante niveles de pH bajos. El establecimiento de la relación entre el desarrollo de la microestructura y las propiedades que esta supone, así como la monitorización y modelación de los procesos implicados, son asuntos de gran importancia en términos de investigación de materiales de construcción. A parte de caracterizar la microestructura y las propiedades en materiales cementosos desde un punto de vista micro y/o macroscópico, es esencial ampliar y combinar esta información con la caracterización facilitada a nanoescala, lo que se buscó en el desenvolvimiento de este trabajo por diferentes etapas buscando encontrar soluciones para el problema propuesto, utilizando comparativamente micro y nanosilice. Inicialmente se hizo una caracterización de los materiales usados en esta investigación utilizando diferentes técnicas como la difracción de rayos X (XRD), la Espectroscopia Infrarroja modificada de Fourier (FTIR) y la Microscopia electrónica de barrido (SEM). En continuación se fabricaron capas finas de nanosilice utilizando una evaporadora de haz de electrones (e-beam) con el objetivo de analizar la hidratación del compuesto en contacto con hidróxido de calcio en solución en nanoescala utilizando el Microscopio de fuerza atómica (AFM). Buscando la confirmación del espesor de la capa de nanosilice el Interferómetro óptico (OI) fue utilizado. Al final, probetas de mortero fueran producidas con el objetivo de comparar las propiedades mecánicas con el uso o no de micro y nanosilice. Los resultados muestran que hay diferencias físicas entre la micro y la nanosílice principalmente en relación a los tamaños de las partículas, aunque químicamente las dos son muy similares. Los ensayos de resistencia a flexión y compresión a 3 días no presentan diferencias importantes entre probetas con y sin las adiciones, pero se espera que el comportamiento cambie con el tiempo.

Engineering operations in space require the optimization of a wide variety of procedures and the design of new, lighter and more durable materials. One of the main concerns of human-operated space activities is exposure to radiation, attaining doses that may eventually exceed those considered within safety limits. Polymers are perhaps the most promising materials for radiation absorption (due to their relatively high hydrogen content), generally low specific weight and wide variety of mechanical properties. Their response to space environment is, however, greatly dependent on factors such as chemical composition, thermal treatment and stress state under service conditions. Their structural makeup can lead to a decrease in durability, especially under harsh radiation (e.g. ultraviolet) and/or chemical (e.g. ozone)attack. It is known that the response of different kinds of polymers can be very different, from generation of surface roughness (and subsequent increase in surface area) to breakup and disintegration. This work aims to study in a systemic way the effects of combined ultraviolet/ozone irradiation on the surface properties of a variety of polymers, in order to shed light on the nanoscale mechanisms of surtface modification. Treated and reference samples will be studied by means of Atomic Force Microscopy and both optical (interferometric) and mechanical profiling. Images obtained will be processed with professional software in order to obtain quantitative parameters to assess the level of (nano)modification in each case. This information will eventually be useful for the assessment of different applications of polymer materials in the space environment.

In the past 20 years, considerable attention been paid to returning to our natural satellite with robotic and, eventually, manned mission(s) not only to continue one the most scientifically fruitful exploration programs in history, but also to open new perspectives on engineering in planetary surfaces through lunar resource utilization. Among the so-called lunar resources, oxygen is probably one of the most needed and versatile. Applications of this gas range from fuel to life-support systems. However, oxygen in the Moon is present not as an atmospheric gas but combined with other elements forming minerals. Despite its very large abundance (almost 50% of the mineral material may be oxygen) its extraction and exploitation requires some technologies of not-so-straightforward application in a hostile environment such as the lunar surface. Among these technologies, hydrogen reduction of ilmenite (FeTiO3) has shown to be one of the most promising. This mineral is abundant in the high-Ti basalts, identified in the Apollo XI and XVII landing sites. Processing of ilmenite with molecular hydrogen at temperatures of about 800ºC yields to the formation of metallic iron, titania (TiO2) and water. This latter product, can be electrolyzed with relative ease to produce oxygen and hydrogen which, in turn, can be recycled back to the initial reduction process. Recent evidence of lunar water may add new hopes to considering the potential utilization of the ilmenite reduction process for oxygen extraction. Our work aims at providing additional information on the hydrogen and water estimations on the moon and on the mechanisms and kinetics of ilmenite reduction in order to optimize the operation of an eventual ilmenite processing unit (IPU) on the lunar surface. A variety of terrestrial ilmenites close in composition to the lunar samples have been characterized and treated with a Temperature-Programmed-Reduction (TPR) procedure. TPR allows a quantitative evaluation on the effect of temperature on the amount of hydrogen “absorbed” by a system, as well as the products and ultimately the efficiency of such reaction. In this paper, such parameters have been studied at temperatures between 100 and 900ºC, at different scan rates in order to assess the efficiency of the utilization of hydrogen on the lunar surface Scanning rates very high affects the equilibrium of the conversion, and very low ones change the expected behavior of the curve during the reduction and it can cause instabilities. A good value of scanning rate has been determined around 10C/min.