Abstract: The property of an organic molecule able to emit light efficiently from both their singlet and triplet excited states is called biluminescence. This dual state emission, particularly at room temperature, is difficult to achieve by purely organic molecules. It is possible only if the competitive thermal decay is suppressed effectively, enhancing the yield from the triplet state (i.e. phosphorescence) in addition to the conventional fluorescence. Biluminescence was identified in a simple host:guest system in which the biluminophore (i.e. an organic molecule showing biluminescence) NPB [N,N’-di(naphtha-1-yl)-N,N’- diphenyl-benzidine] is embedded in a rigid matrix, for example, the polymer PMMA [poly(methyl methacrylate)]. This system is unique not only due to the dual state emission, having fluorescence and phosphorescence emissions at 425nm and 530nm, respectively, but also because the large range of exciton lifetimes is extended up to nine orders of magnitude between nanosecond fluorescence and second phosphorescence. Up to date, efforts have been placed exclusively in the research of room temperature phosphorescence (RTP), although fluorescence can be observed from these systems as well. Therefore, the aim of this thesis was the investigation of the fundamental photophysical processes and characteristics of biluminescent organic molecules, in addition to their usage in promising applications as it will be described next. For instance, the most used approach for oxygen sensing is based on quenching of luminescent excited states, following a scheme of optical monitoring, i.e. correlating luminescence over-time data with oxygen concentrations. However, regardless whether one pursues fluorescence or phosphorescence quenching, they share a common drawback: They cannot monitor the effect of sample degradation due to extensive light exposure. In fact, one cannot distinguish between oxygen having penetrated the film and quenched the luminescence, or the sample being degraded over time due to e.g. photobleaching of the emitting molecules. The former represents an issue, especially for build-in applications. Now herein, it was proposed to use biluminescence to exclude degradation processes from oxygen sensing data evaluation, through a simple fluorescence-to-phosphorescence intensity ratio. This can be achieved, because it was proven here that the fluorescence is not directly quenched by oxygen, whereas the long-lived RTP is sensitive to it. Therefore, the fluorescence acts as self-referencing in a biluminescent sensor, which serves as an alternative solution to monitor oxygen concentrations. Additionally, the integration of the sensor into optoelectronic devices is considered as a potential future direction. Furthermore, it was revealed in this thesis that the difference in exciton lifetime yields to a significant limitation of luminescence efficiency, because of exciton accumulation under continuous illumination, causing bimolecular processes like singlet-triplet and triplet-triplet annihilation (STA and TTA, respectively), as well as optical saturation. All those processes occur already at moderate excitation intensities. It was demonstrated through sample engineering and oxygen quenching experiments, that the triplet exciton density can be controlled over several orders of magnitude, allowing to study exciton interactions between singlet and triplet manifolds. Consequently, the presented biluminescent system represents an illustrative role model to study excitonic effects in organic molecules. For example, in organic light-emitting diode materials, where the aforementioned effects i.e. STA, TTA and saturation, are application relevant but much more difficult to investigate. Mainly because light emission can be observed only from one state, instead of both states like in biluminescence.

Abstract: Biluminescent organic emitters show simultaneous fluorescence and phosphorescence at room temperature. So far, the optimization of the room-temperature phosphorescence in these materials has drawn the attention of research. However, the continuous-wave operation of these emitters will consequently turn them into systems with vastly imbalanced singlet and triplet populations, which is due to the respective excited-state lifetimes. This study reports on the exciton dynamics of the biluminophore NPB (N,N′-di(1-naphthyl)-N,N′-diphenyl-(1,1-biphenyl)-4,4-diamine). In the extreme case, the singlet and triplet exciton lifetimes stretch from 3 ns to 300 ms, respectively. Through sample engineering and oxygen quenching experiments, the triplet exciton density can be controlled over several orders of magnitude, allowing us to study exciton interactions between singlet and triplet manifolds. The results show that singlet−triplet annihilation reduces the overall biluminescence efficiency already at moderate excitation levels. Additionally, the presented system represents an illustrative role model to study excitonic effects in organic materials.

Diluting organic molecules in a polymer matrix material suppresses non-radiative behavior, leading to biluminescence, wherein light is emitted efficiently from both singlet and triplet states. In summary, biluminescence has developed into a thoroughly optimized and unique emissive system. Among the characteristics obtained through this system, the most significant is the ability of biluminophores to offer direct access to the radiative states of both spin manifolds (singlets and triplets) in organic molecules without the requirement for special or complex material combinations. As a result, an exciton is given the chance to re-emit its energy, regardless of its initial state. In future work, we intend to increase the toolset of organic biluminophores by screening materials to determine the structure-property relationships behind persistent phosphorescence, and to identify molecular building blocks that are suitable for the development of future materials. In addition, we will intensify our exploration of biluminescence for future applications (e.g., sensing).

Abstract: For the first time a comprehensive life cycle assessment (LCA) is reported of a large-area perovskite/Si tandem photovoltaic (PV) module of about 2 m², with an assumed power conversion efficiency of 30%, 30 years lifetime and an annual degradation of 0.5%, manufactured in a 1 GW production plant. By means of the LCA method, we calculate the contribution to the International Reference Life Cycle Data System (ILCD) impact categories associated with a perovskite/Si tandem PV system compared with a passivated emitter and rear cell (PERC) used as reference. We consider a functional unit of 1 kWh of generated direct current electrical energy from the tandem module over its lifetime. It was found that the most significant environmental hotspots are the silicon wafer production and the balance of system (BOS), especially the mounting system, inverter and electric installation. Overall, the impact contributions to the environment caused by the perovskite sub-module are below 1% throughout all the ILCD categories in focus: climate change, freshwater ecotoxicity, water resource depletion and human toxicity. Even the contribution of lead to human toxicity is just about 0.01%. For all the impacts assessed, the perovskite/Si tandem shows a decrease of between 17-20% of the contributions to each impact category compared to the PERC-module based reference PV system, if the Si bottom sub-module has an initial cell efficiency of at least 22% with 1% cell-to-module (CTM) loss, and the perovskite top sub-module has a minimum initial cell efficiency of 18% with at most 5% CTM loss and a transmittance near IR region larger than 80%. The key result found in this work is the relevance of the performance and reliability of the PV system to achieve lower environmental impacts. A comparison between optimistic, realistic, and pessimistic scenarios was performed to investigate this matter: in the worst-case scenario, the environmental impact of the PV tandem system would have a general 50% increase throughout all ILCD impact categories against the realistic case, whereas in the optimistic one, the results suggest a reduction of 46% to the global impact contributions, compared to the realistic scenario.

Abstract: The history of Colombia has been defined by the paradox of the coexistence of violence and economic growth. While the economy of the country has grown almost uninterruptedly since the middle of the 20th century, in 2019 the state was still not fully capable of reasserting its presence nor of providing justice or security for all of its citizens across its territory. This chapter analyses the paradox of the coexistence of armed violence and economic growth in Colombia, in which parts of the elite sections of the country benefit by the lack of security and justice. Violence is good for business, although not good for statehood.

Resumo: Após décadas das primeiras publicações sobre a plasticidade transcricional do sistema digestivo dos insetos polífagos, ainda não se conhece em profundidade como os genes são regulados e as vias de sinalização envolvidas neste mecanismo adaptativo. Inicialmente, foi mostrado que a adaptação de lagartas de H. armigera à alimentação com inibidores de peptidase de soja (IPs) se deve à alteração do perfil transcricional de genes codificadores de serino peptidases do sistema digestivo. A presença dos IPs na dieta causou mudanças na regulação de genes de um amplo repertório de enzimas proteolíticas, principalmente com o aumento de genes de tripsinas. A regulação diferencial de enzimas digestivas foi associada à adaptação da H. armigera ao efeito anti-nutricional dos IPs. Além disso, a análise de dados de expressão gênica em larga escala (RNA-seq) mostrou que aproximadamente 40% dos transcritos (cerca de 500 epialelos potenciais) induzidos pelos IPs foram transmitidos à geração seguinte, apesar das lagartas desenvolverem-se em dietas desprovidas de IPs. A fim de caracterizar um possível mecanismo epigenético responsável por este mecanismo adaptativo, foi realizado o metiloma do sistema digestivo das lagartas da primeira geração (alimentadas com e sem IPs) e das progênies de lagartas expostas aos IPs. Epialelos de metilação do DNA foram associados aos controles transcricional e traducional, sugerindo um possível envolvimento da alteração do padrão de metilação na adaptação de H. armigera aos IPs. Este trabalho abre novas perspectivas no entendimento do polifagismo e a plasticidade dos insetos na alimentação de um amplo número de plantas hospedeiras, influenciando o seu curso evolutivo.

Resumen: Las aplicaciones de la electrónica exigen mayor eficiencia de los dispositivos electrónicos que se utilizan hoy en día. Entre los aspectos mas importantes esta el área ocupada por un circuito: Se busca que los dispositivos electrónicos ocupen el menor espacio posible. La tecnología que se utiliza hoy en día para fabricar dispositivos semiconductores está llegando a un punto limite, donde cada vez es mas difícil obtener reducción en el tamaño sin afectar otras características del dispositivo. La nanoelectrónica está evolucionando a un punto donde se hace posible la construcción de dispositivos semiconductores que presenten mejores características que los fabricados en la actualidad. Este documento muestra una revisión bibliográfica sobre nanotecnología, con el fin de presentar una propuesta de investigación para implementar transistores basados en nanotubos de carbono. Este trabajo está en su fase inicial, se espera que a finales del 2009 se tenga una metodología de implementación de transistores utilizando nanotecnología.

Abstract: La fabricación de las celdas fotovoltaicas inorgánicas son aquellas cuyo semiconductor es a base de material inorgánico (Si, AsGa, CuInS2, CIS, CdTe), son poco económicas, por ende, es necesario hallar una manera de producir celdas solares sin que la inversión económica sea costosa. Debido a esta dificultad tecnológica, se ha optado por usar semiconductores orgánicos en la fabricación de las celdas. Los paneles solares orgánicos no se contemplan como un sustituto a los de silicio como material semiconductor, sino un complemento para crear mejores fuentes de energía. En este caso, se plantea el uso de los nanotubos de carbono (CNT) como material semiconductor en la fabricación de celdas fotovoltaicas orgánicas.

Abstract: Terzo Valico dei Giovi is a huge railway project covered by more than 90 km of tunnels between Milano and Genova, to join the net of high speed and high capacity trains, part of the Rhine Alpine corridor of the Trans European Transport Network (TEN-T) to connect the main economical capitals of Europe improving the performance of transport and merchandise trade. The present study is according to the methodology used for ADECO-RS applied in the tunnels from Terzo Valico dei Giovi, referred about the support and the tunneling conventional method foreseen in DT2 (Direzione Tronco Piemonte) with the jobsites studied cases about DCP2 (Direzione Cantiere Piemonte 2). The thesis proposes to describe the Terzo Valico dei Giovi project with the technical and organizational aspects of conventional tunneling related to Vallemme and Moriassi jobsites. In addition, a description of the case studied about excavation in the presence of gas methane flow (Grisou) and the problem/solving encountered during the cycle excavation, the production activities and the management of Quality, Safety and Environment.

Abstract: One of the strategies to improve governments’ allocation of resources, particularly when these are insufficient to meet all the public needs, is the use of targeting indices. Generally, a targeting index is a linear combination of wellbeing indicators (for example years of education, dwelling conditions, and so forth) that orders the members of the population according to their living conditions to classify and identify the beneficiaries of social programmes. The weighting method that we propose maximises a function that depends on the number of poor beneficiaries, by income and/or expenditure, given some normative restrictions. Therefore, the indices designed with this method target poor people taking into consideration not only the income dimension, but also other dimensions, such as health, nutrition, and dwelling, although they are not correlated with income and/or correlated with one another. The method for taking these dimensions into account is to specify weighting restrictions by an indicator of wellbeing. In other words, we establish maximum and minimum values for the weights according to the number of indicators and the needs of social programmes. These values maintain the balance between income-based weights and normative weights. Because of these characteristics, we call our method Maximising Poor Beneficiaries with Normative Restrictions (MPBR). The algorithm behind MPBR can maximises or minimises any function. For instance, in the first exercise of this study, it exclusively counts the number of expenditure -poor beneficiaries, and in the second it contemplates both income-poor and expenditure-poor beneficiaries, given double weight to those that meet both conditions - thus the poorest of the poor households become the first beneficiaries of social programmes-. We find that when the function to maximise counts exclusively the number of income-poor (or expenditure-poor) households before a cutoff, it is equivalent to minimising the IE (Inclusion error) and EE (Exclusion error). In fact, we theoretically and empirically demonstrate that the models that minimise the IE and EE (considering income-poor or expenditure-poor households) are probabilistic models. Therefore, we conclude that probabilistic models are a useful tool to determine approximately the minimum IE and EE that can be obtained with a set of indicators. Applying MPBR, we find that when the increase in an indicator of wellbeing statistically increases the probability of not being expenditure-poor, the weight of the indicator converges to a specific positive value to maximise the number of expenditure-poor beneficiaries; in contrast, if the increase in an indicator statistically decreases this probability, the weight of the indicator converges to the minimum allowed weight. In the case in which the indicator is not statistically significant in the probabilistic model, its weight does not converge to a specific value. However, when the weighting restrictions become stronger (for example a greater minimum weight), most of the weights converge to a value. In a comparison of MPBR with other weighting methods (for example PCA and normative method), we conclude that the index estimated with MPBR has a smaller IE and EE and distributes the weights between indicators more equitably than the indices calculated with other methods.