The capture of CO2 from a flue gas stream using chemical absorption was studied using two different aqueous amine solvents: the conventional 30% wt. monoethanolamine (MEA) and the novel 40% wt. piperazine (PZ), using a conventional absorption/stripping flowsheet and different combinations of advanced flowsheet variations including absorber intercooling (AIC), stripper interheating (SIH) and adiabatic lean flashing (ALF), amounting for a total of twelve flowsheet alternatives. Additionally, the conventional flowsheet was also studied using 30% wt. 2-amino 2-methyl 1-propanol (AMP). The simulations were performed in Aspen Plus® v.2006.5 using the latest thermodynamic frameworks published by AspenTech [2010] for each solvent, which include regressed interaction parameters for the ENRTL activity coefficient model, adjusted physical properties and kinetic parameters. The absorption and stripping operations were simulated using the rate-based model built in Aspen Plus®. The conventional MEA flowsheet was found to have a minimum specific reboiler duty around 3.854 GJ/ton CO2 and a minimum total equivalent work around 308 kWh/ton CO2, correspondent to a lean solvent load of 0.24 mol CO2/mol MEA. The limited PZ solubility restricts the correspondent to 0.25 mol CO2/mol PZ, giving a of 3.232 GJ/ton CO2 and a of 286.8 kWh/ton CO2 for the conventional PZ flowsheet. The best technical performance was predicted for the AIC + SIH flowsheet using PZ, obtaining a of 2.463 GJ/ton CO2 and a of 239.5 kWh/ton CO2, representing reductions of 36.1% and 22.4% respectively, when compared to the baseline conventional MEA flowsheet. A simplified economic assessment was performed to account for the different solvents, equipment types and steam quality requirements of the evaluated flowsheets, using the annualised cost of purchased equipment and the utilities cost, obtaining the same preference for the PZ based AIC + SIH flowsheet with 17.7% less cost than the conventional MEA flowsheet.

El tema de aseguramiento del suministro energético, especialmente en lo concerniente a la protección de las infraestructuras energéticas, ha suscitado especial interés en los países de la OCDE en los últimos años. Al respecto, el Consejo de la Unión Europea ha aprobado la Directiva 2008/114/CE (sobre la identificación y designación de infraestructuras críticas europeas) y el Departamento de Seguridad Nacional de EE.UU ha publicado el NIPP en 2009 (National Infrastructure Protection Plan). Dichos planes contemplan el establecimiento de procedimientos para la protección y seguridad de las infraestructuras críticas, en el marco de estrategias de gestión de riesgos. A partir de los conceptos establecidos en ambos programas, en esta tesis se presentan propuestas metodológicas aplicables a la identificación de riesgos y a la evaluación de amenazas en la red de infraestructura eléctrica. Se propone el uso de mapas interconectados de riesgos, complementados con la determinación de componentes de riesgo en el sistema de infraestructura. Así mismo, se propone el uso de las cartas de riesgos, mediante las cuales se obtiene una representación gráfica e intuitiva de la evaluación semicuantitativa de los riesgos más relevantes. Por otro lado, se formulan y validan estrategias metodológicas para la evaluación de la vulnerabilidad estructural en redes de transporte de alta tensión, a partir de la combinación de modelos de flujos de carga y medidas de grafos de libre-escala. De esta manera, es posible estudiar los escenarios de riesgos en función de los eventos que pueden desencadenar fallos en cascada dentro de un sistema eléctrico de potencia. Se demuestra la utilidad de las técnicas de teoría de grafos para analizar las respuestas de los sistemas eléctricos de potencia y evaluar la vulnerabilidad de las redes de transporte. Un ejemplo de dicha evaluación se desarrolla mediante valoración de la tolerancia de redes de prueba IEEE contra fallos aleatorios y contra ataques deliberados. Adicionalmente, se ha realizado una aplicación de la propuesta metodológica para evaluación de vulnerabilidad en los sistemas eléctricos de alta tensión en Colombia y España. Como resultado, los trabajos desarrollados en la tesis aportan nuevos instrumentos para la gestión de riesgos en infraestructuras eléctricas, en particular en redes de transporte en alta tensión.

Oriente Antioqueño is an important region within Antioquia. There, the production of vegetables represents an important element of the economy, with approximately 12,000 farmers cultivating vegetables in four municipalities. There, farmers have inadequate training in agricultural practices, they lack adequate instruction on how to use fertilizers and pesticides, and also they do not have the appropriate instruments, among many other technological pitfalls. This situation leads to high levels of crops losses, higher costs of production, and sometimes, noncompliance with phytosanitary standards and environmental damage. In order to solve the problem this thesis analysis the outcome from central policies and covers the analysis of two international cases (in Brazil and Nicaragua) looking for new strategies to foster competitiveness in the production of vegetables.I identified four policy options: (1) maintaining the status quo, (2) increasing municipal revenues and restructuring UMATAs, (3) upgrading Law 811, and (4) implementing a cluster development program. The first alternative assesses the implications of letting the market operate under current conditions. Policy alternatives 2 and 3 evaluate the benefits from restructuring agricultural extension offices and the agreements of competitiveness. Finally, implementing a cluster development program explores the gains from creating a local strategy to generate an enabling environment in the production of vegetables. After evaluating the policy options using the criteria of political feasibility, administrative feasibility, effectiveness, efficiency, and equity, I recommend implementing a cluster development program. This option is likely to generate higher benefits as it counteracts problems in the supply and the demand side of the vegetables supply chain. Moreover, as a program implemented at the local level by local institutions, it promises better results.

This paper presents the first ecological economic model of tropical dry forest on Bonaire Island. The model projects the economic benefits of the ecosystem services provided by the forest under two management alternatives: The baseline scenario assumes that the current short-term extractive practices continue for the following thirty years while the alternative scenarios includes the implementation of a birdwatching program, enhancement of agriculture, goat eradication and husbandry and reforestation program. The study reveals that the alternative scenario brings about $8.5 million more than the baseline scenario. Higher benefits could be obtained depending on the combination of the implemented programs though the implementation of the goat eradication and husbandry program together with the reforestation program is the most cost-efficient combination. The sensitivity analysis showed that doubling tourism doubles the economic benefits while reducing it in a half increases four times the economic benefits. In the other hand, the analysis showed that grazing by goats and other roamers costs about $4 million to the island; it is necessary to reduce the grazing to 70% of the current state in order to have benefits and goats at the same time. The research also estimates the value of seed dispersal and pollination on the Bonairean forest in $ 17 million.

The aim of this paper was to measure the effect of different credit-related events on the option implied volatility of several companies that belong to the Dow Jones Euro Stoxx 50 index list. Measuring the effect of credit events on volatility will augment on the already important body of literature that investigates the volatility-related phenomena; in particular those who research the effect of news on volatility. I find that, over the entire window around the credit events, there was a decrease in the implied volatility but that only the negative events have a statistically significant effect, which reflects the stronger information content of negative credit events researched by previous papers. I also found that this negative effect is mainly due to a strong “reversal” effect in the post-event 10-day period, where the negative effect is stronger and more statistically significant (particularly for the negative events). Furthermore, during the pre-event period there is not much evidence that supports any type of foresight of the market. My results also suggest that there is a difference between the behavior of the implied volatility when the events are outlook changes and credit reviews, and when the event is a rating change (downgrade/upgrade).

This dissertation explains in detail how Albrecher et al. (2008) developed three different model independent lower bounds and one upper comonotonic bound for European Asian call option prices. The main characteristic of these bounds is that Albrecher et al. (2008) only use the observable plain vanilla option prices in the market to calculate them whichallows for the _nding of static hedging portfolios. The concepts behind the bounds are basically Jensen's inequality and some properties of comonotonicity of random vectors. This document will also explain how to implement these bounds when the market has a finite number of options available, moreover, how to do it when these bounds do not involve strikes found in the market. Two facts will be used: the call option price function is convex with respect to strike, and the lower and upper bounds for a call option suggested by Bertsimas and Popescu (2002). Finally, as an example, one application of these bounds in the Colombian FX option market will be presented.

El objetivo principal de la presente tesis doctoral es la determinación de los HCG e HAP asociados a las partículas, emitidos por un motor diésel utilizando diversos combustibles de origen renovable. A partir de este objetivo general se definen varios objetivos específicos: La puesta a punto de un método efectivo para la identificación y cuantificación de los HCG individuales en los gases de escape del motor diésel. Este procedimiento debe incluir la metodología de muestreo, extracción, concentración y análisis, garantizando la conservación de los analitos objetivo. El desarrollo y validación de una metodología novedosa de especiación de los HAP asociados a las partículas. Esta técnica debe utilizar una combinación de extracción térmica y microextracción en fase sólida, de modo que se eliminen los inconvenientes de la extracción con disolventes tradicional y se incremente la selectividad y repetitividad del método.

The successful evolution of a power system is achieved when its future growth path is visualized. Visualizing and interpreting the future are crucial to understand the risks to which the power system is exposed. These are mostly caused by the interdependencies between the power system and other systems (e.g., transportation sector, fuels sector, industry, etc.); and the resulting uncertain environment where these systems perform. Then, the objectives of planning are to reduce the risks of uncertainties and to gain some control over the future by linking it with the past; otherwise risks might materialize in catastrophic consequences. In particular, motivated by the need of mitigating future risks in power systems, this work focuses on finding robust and flexible investment strategies in the generation capacity expansion planning problem under exposure to multiple uncertainties. They are present in different sources and types such as fuel costs, investment and operational costs, demand growth, renewables variability, transmission capacity, environmental policies, and regulation. The problem when considering multiple uncertainties is much harder, not only because the increased computational effort, but also because it is hard to model the combination of their occurrences in a single optimization problem. Since each uncertainty deserves special treatment, they are grouped into two categories. Those (categorical) uncertainties that really impact the portfolio investment decisions are classified as global; whereas those that quantitatively describe the intrinsic imperfect knowledge of the categorical are considered local uncertainties. So, to effectively account for robustness, defined as the ability to perform well under unforeseen situations, and flexibility, defined as the ability to adapt cost-efficiently to different situations, modern tools are illustrated and implemented in a computationally tractable manner, resulting in promising planning tools under uncertainty.

In earlier decades, a number of authors have been looking at how commuters value the usefulness of travel time and at which point it is still considered to be a disutility to minimize. This document presents the results of a survey which was carried out on different transportation modes in Northern California. The results of this study show how the utility of travel time may change from one person to another, unveiling the latent relationship between several factors (i.e. Attitudinal factors, primary mode of transportation, age, gender, etc.) and what we consider the usefulness of travel time. This study included several considerations made from different approaches, including linear regression analysis and ordered probit models. The dependent variable was always considered to be the usefulness of travel time represented in the final survey by an ordinal variable. Moreover, the study comprised data segmentation (i.e. primary mode of transportation) which explained some conceptual differences between a pooled model and “active-passive” models. Finally, the outcome of this study shows how active travel modes (i.e. Car driving) are usually the most unattractive, for the reason that the possibility of engaging in different activities while traveling is very limited. Similarly, how the activity itself may change the perception of travel from a disutility to minimize to a transition or mostly useful time.

In many cultures palms offer a vast number of products, especially Non-Timber-Forest Products (NTFPs), which have been traditionally used by indigenous and mestizo groups in Latin America. Some species have gone beyond the domestic use and their commercialization has reached local, national and international markets. Among the palm products that are widely commercialized in South America are palm heart (Euterpe oleracea), extracted from the young unfolded spear leaves of the palms, and the handicraft woven from fibers (Astrocaryum chambira, A. malybo and A. standleyanum), all extracted from the leaflets. In Colombia, these four palm species are economically important for the harvesting communities as well as for wholesalers and retailers. However, commercialization has been based on the extraction of raw material from wild palm stands up to the point that several palm species are threatened by developing markets for their products, and the need of income for the harvest communities and industry. The general objective of this thesis is to describe the value chains of palm products from E. oleracea, A. chambira, A. malybo and A. standleyanum in different Colombian regional markets, as well as national and international markets, and to analyze the economic importance, potentials and implications of this trade. Data on the four value chains was gathered through interviewing all actors of the value chain and revising the literature about the commercialization of these palm products. This study assesses the main actors or organizations in the commercialization chains, their specific activities, different routes to trade products, and how well the chains currently work by conducting a qualitative and quantitative value chain analysis.Major results involve particular dynamics and distributions of the profits along each value chain, as well as common aspects: the value chains are short, simple, the commercialization channels need to be strengthened, the scarcity of the raw material is a crucial constraint for the commercialization of the products. Unsustainable harvest practices are common. Moreover, the marketing potential of each group of palm products as well as promised target markets are characterized. The principal contribution of this thesis consists in shedding light on the current status of the value chains of these four palm species in Colombia, and proposing possible routes of development to strive for sustainability in each of the value chains analysed. Moreover, this study provides information about the economic importance of the palm products to the local communities and the need to upgrade the commercialization channels, products and communal incentives to assign equitable incomes along the chain.