Resumen: El tema de la seguridad energética, se define como la capacidad de un país para satisfacer la demanda nacional de energía con suficiencia, oportunidad, sustentabilidad y precios adecuados, en el presente y hacia un futuro. La problemática de la seguridad energética constituye en la actualidad uno de los temas centrales mundiales que afectan de forma esencial a las economías y la política de seguridad de los Estados. Precisamente el interés estratégico asociado a la seguridad energética de las naciones, constituye la motivación para abordar un trabajo de investigación que permita identificar y evaluar las amenazas a la seguridad energética, las cuales necesiten ser analizadas por cualquier nación. En este trabajo se realiza la identificación, análisis y evaluación los riesgos del suministro energético en un país. Se destaca el enfoque de algunas herramientas para la toma de decisiones y más concretamente su aplicación en el ámbito de la identificación y evaluación de amenazas al suministro energético. Adicionalmente se revisa y se actualiza el estado del arte del tema de aseguramiento del suministro energético, desde el punto de conceptual en países de la OCDE, y específicamente, de acuerdo con la directiva 2008/114/CE de la U.E. (sobre la identificación y designación de infraestructuras críticas europeas) y la NIPP de EE.UU (National Infrastructure Protection Plan) al tiempo que se revisa la situación de los países europeos, se identifican sus vulnerabilidades y las acciones propuestas para el aseguramiento del suministro energético. La revisión y actualización del estado del arte en el aseguramiento energético, se acompaña de una revisión en el panorama de los países europeos, con mayor énfasis en el caso español. De esta manera, se realiza una identificación de las vulnerabilidades, así como las acciones propuestas, las cuales se evalúan a través de una metodología de Administración del Riesgo, ajustándose a la normativa actualmente implementada por empresas del sector energético. Los capítulos que conforman este trabajo, así como los respectivos anexos, se complementan con información referida a las metodologías de apoyo a la toma de decisiones y simulación de sistemas, que pueden ser empleadas en futuras investigaciones relacionadas con aplicaciones en distintos ámbitos para la priorización de decisiones. De esta manera se puede realizar la comparación de algunas técnicas de apoyo a la toma de decisiones para su aplicación en un caso de estudio de identificación y evaluación de amenazas a los sistemas de suministro energético de un país. Igualmente, se presenta información relevante con la situación geopolítica, la economía de la energía, la escasez de recursos y la vulnerabilidad de las infraestructuras energéticas y los recursos claves, que hacen parte del concepto de “seguridad energética”. De esta manera, se efectúa un aporte desde el punto de vista metodológico, dada la recopilación y análisis estructurado de la información, que puede tomarse como un documento técnico y científico en el área del “aseguramiento energético”. Abstract: The issue of energy security is defined as the ability of a country to meet domestic demand for energy sufficiency, opportunity, sustainability and appropriate pricing, both in the present and in the future. This issue of energy security is now one of the key topics that affect the world's essential to the economies and security policy of states.Precisely the strategic interest associated with the energy security of any nation is the motivation to tackle a research project to identify and assess threats to energy security, which need to be analyzed by any nation. In this work we make the identification, risk analysis and assessment of energy supply in a country. It highlights the approach of some tools for making decisions and more specifically its application in the field of identification and evaluation of energy supply threats.Furthermore, we make a review and update of the state of art in the subject of supply security, from the conceptual point of OECD countries, and specifically, in accordance with EU directive 2008/114/CE (On the identification and designation of European critical infrastructures) and the U.S. NIPP (National Infrastructure Protection Plan) at the same time as reviewing the situation of European countries, identifying their vulnerabilities and the proposing some actions in the concept of energy supply. This review and update of the state of the art in energy supply security, is associated with an outlook description for European countries, emphasizing on the Spanish case. This way, we make an identification of vulnerabilities and we propose actions, which are assessed through a Risk Management methodology, which is also aligned to the regulations currently being implemented by companies in the energy sector.Both chapters and amendments of this work are supplemented with information concerning the methodologies to support decision making and system simulation, which can be used in future researches related to applications in variousfields for prioritizing decisions. In this way it is possible to make the comparison among some techniques in order to support decision making for application in a case study of identification and assessment of threats to energy supply systems of a country. We also provide information relevant to geopolitics, energy economics, scarcity of resources and the vulnerability of energy infrastructure and key resources, which are part of the concept of energy security. Thus, a contribution is made from a methodological point of view, given the structured collection and analysis of information that can be taken as a technical and scientific document in the area of “energy security”.

This professional dissertation aims at understanding and questioning the present supremacy of the densification paradigm in urban planning. After presenting the theoretical bases of urban spatial structures, the paper studies the urban growth dynamics in Colombian cities. It focuses on a special category of cities where the densification paradigm proves to be especially inefficient: intermediary rapidly growing cities in developing countries. On the light of these findings, the paper analyses an alternative experience of urban development in Colombia by presenting the Urban Expansion Initiative conducted in Valledupar. Finally, the paper discusses the relationship between densification, urban poverty and urban sustainability. 

Biological parameters and spatial variation of H. arguinensis were estimated inside the Ria Formosa, Portugal. Data collected during visual census (November 2012 to March 2014) and random samplings (February to March 2014) were analyzed. The average sizes were estimated in six localities with a total range between 4 and 48 cm. Three sites showed significant diferences in the average size: Armona, showing the highest mean and Barinha and PFE with the smallest mean (27.4, 17.5 and 21.7 cm respectively, p < 2.2e-16)  Asymptotic population length L?=70 cm and growth coeficient k=0.87 were estimated. The growth pattern showed seasonality using Hoenig’s function. The coverage of mud and sea grass (Z. Noltii, and C. nodosa) were the variables explaining better the diferences in abundance of H. arguinensis among sampled sites, demonstrating the importance of these sea grass species in the persistence of the species in the Ria Formosa.

In this paper, I examine the case of Angosturas, a large-scale gold mining project by the Canadian-based company GreyStar in the sensitive high wetland páramo of Santurbán in the northeast of the Colombian Andes. Angosturas is the closest large-scale gold mining project to the phase of extraction in the country, and constitutes a referent for other ongoing cases. In 2011, the Ministry of the Environment, Housing, and Territorial Development (hereafter: Ministry of the Environment) denied the environmental license to the company to start extraction operations. Despite this government’s recent ruling, GreyStar (which renamed itself ‘Eco Oro’ after the 2011 decision) and other mining companies have continued their quest to gain permission to begin extraction in the area. I explore why these continued attempts to change government policy regarding extraction licensing is possible within the existing juridical framework. In particular, I ask how Sustainable Development allows for the classification of large-scale mining as a public utility activity. This paper is a criticism of Sustainable Development and the limitations it places on hearing certain kinds of languages and discourses that resist the commodification of nature. The case study allows me to address a gap in the existing literature, and outline the distinctive situation of non-legally recognized ethnic minorities (e.g. peasant farmers, small-scale miners, and the urban population).

Quantum simulation describes a great variety of process observed in laboratories and daily life, however, as soon as the computer programs involve more particles, time and storage turn out to be critical issues that constraint the execution of larger simulations. Tensor Contraction Schemes for 2D Problems in Quantum Simulation is based on the ideas of Huckle and Waldherr and is a courageous attempt to describe many-body systems accurately without the intrinsic dimensional problems. To achieve this goal, two well-established techniques are applied to represent large vectors implicitly and, through a variational-based numerical method, minimise the related optimisation problem. Remarkably, the contraction schemes demand linear storage and time resources only. As result, the proposed scheme was able to produce solutions up to the first significant digit for 12-particle system, taking no more than few iteration.Finally, there are still open issues regarding the accuracy in the vector representation and the local optimality of the iterative method that must to be addressed in future investigations.

Sierra Leone’s war is known for the high prevalence of child soldiers actively engaged during its lengthy civil war. 70% of the combatants were underage when recruited, with most of them joining the irregular armies voluntarily. In spite of the superficial causes that may differ from case to case, economic, educational and socio-political factors have been the most recognized driving forces that influence the decision of children and youngsters to join the armed forces, and were definitely the driving forces for young combatants in Sierra Leone. The crisis of youth originated by the socioeconomic conditions in Sierra Leone and made worse by the Structural Adjustment Program in the 80s, was a key factor for children and youngsters to join the irregular forces. Even though choosing to become soldiers may appear as a conscious decision that involves agency, the structure of the individuals cannot be detached and judged independently. Whether these children volunteered or were coerced, most of them were uneducated and hungry; therefore it is misleading to consider this type of recruitment as voluntary.

Coastal areas are among the most productive ecosystems, and are also heavily populated. They offer different benefits to society, known as Ecosystem Services (ESS). However, an unsustainable ecosystem management reduces their capacity to provide such benefits. The ESS flow decrease has repercussions in human well being and, in order to prevent it, is necessary to identify key areas generating key benefits. This ESS evaluation can be done using monetary and non-monetary methodologies. This evaluation was done with a non- monetary evaluation, considering that intangible benefits like cultural ESS are difficult to quantify only in terms of money. While non-monetary evaluations demonstrate the multi- dimensional nature of human well-being, being monetary value just one important aspect amongst others, e.g. symbolic, cultural, ecological and spiritual (Kelemen et al. 2014). In this thesis, coastal ecosystem types were identified to evaluate their capacity to generate a variety of ESS in the Buenos Aires province, Argentina. To make the ESS assessment, a group of experts was selected and interviewed, using an ESS matrix including different coastal types and ESS of interest, in order to estimate ESS flow. They valuated the ESS in each coastal type using a scale form 0 to 5, additionally, they were asked which ESS they believe are of priority for coastal communities and their conservation. In order to protect other important ESS supply and enhance the human well-being, sustainable tourism and recreation practices, as well as integrated management plans should be implemented in the region.

Resumen: The following project intends to give a short duration album showing how to take South American Andean music into a different level, this task is approached in different ways. By the use of elements from rock and electronic music used to enrich the traditional Andean tunes, in addition to that, some exploration and experimentation with the instruments of the region is being held in order to get new sounds out of them, as well as new ways of mixing and panning them. También pueden ser consultados los mp3 que acompañaron la realización de esta tesis: Arriba quemando el sol -- Senderos Fiesta de San Benito -- Senderos La Partida -- Senderos Ocaso -- Senderos La Palomita -- Senderos

The present work aims to describe and analyse the influence of the reliability and maintainability of the pump systems on the overall plant availability. The study was developed into an aliphatic solvent plant situated in Colombia and owned by the state company Ecopetrol S.A. This plant is composed of six pump systems, each one of them with parallel redundancy, working in series. The first step during the process was the identification of the dominant failure modes for these pump systems according to historical maintenance information collected during the last nine years and recorded in the CMMS of the company. For these dominant failure modes a Weibull analysis was carried out in order to determine the main parameters of the failure probability distribution function and, in this way, to build a mathematical model useful for predictions of future failures. Additionally, a maintainability model was developed based on the current repair process capability of the work shop employed by the company. By employing reliability block diagrams the reliability dependencies between components, items, units, and systems were taking into account. A general model for the whole plant unit was built and several simulations were performed using Monte Carlo techniques. The simulation results were helpful to identify the more sensitive elements for the overall plant availability and suggest some maintenance and operational actions in order to reduce plant downtime and maintenance costs.

Colombia is a privileged country with the amount of water it has, but due to the inadequate conjunction between hydric wealth and land use, we have lived in continuous tragedy, spending huge resources on ongoing reconstructions and helping the floods and landslides victims. However, floods are natural events, in many cases exacerbated by men’s actions over the territory; events to which no country is exempted, but with consequences that vary according to the characteristics of the duo people-territory and its relationships with the water bodies. This document, offers a review of the characteristics and criteria that define a river in good ecological status, and the anthropic pressures, with its impacts and effects over the water courses, deepening into the hydraulic risk, water quality and the disturbance of the natural environments. Continue presenting the “River Restoration” as a new form of river management, reasoning about the Colombian hydric problems, making emphasis on the pollution problems and disasters related to water; and suggesting solutions from the River Restoration perspective for some specific urban cases and linking this new fluvial hydraulic with the “National Police for Integral Management of the Hydric Resource”.