Comparación entre centrales fotovoltaicas y de concentración solar a través de la evaluación del ciclo de vida

At present, the reduction of greenhouse gases (GHGs) emission from electricity generation sector is a subject of great debate. In addition, climate change and water scarcity are important issues for today´s power sector. Therefore, there is a need to accelerate the development of advanced clean energy technologies in order to address the global challenges of energy safety, climate change and sustainable development. Solar energy is the most interesting alternative in this aspect. Each day the solar radiation that hits the earth´s surface is over 4.000 times the global consumption in the world. We only need to collect, to storage and to know how to use it. There are two mainly technologies to use solar radiation: Photovoltaic (PV) and Concentration Solar Power (CSP). PV, is one of the most active, commercially and reliable technology with a potential growth all over the world. It consists in direct conversion of sunlight into electricity in PV cells. Today, PV provides 0.1% of the total global electricity generation. However, PV is expanding very rapidly due to the dramatic cost reduction PV is projected to provide 5% of global electricity consumption in 2030, rising 11% in 2050. CSP is another possibility for using solar radiation. It is not direct conversion. CSP technology uses an intermediate heat transfer fluid (HTF) for transferring the energy contained in solar radiation to the power block in the steam turbine. There are two different options referring to CSP: Central Tower and Parabolic Trough. In this report, we focus in Central Tower. All this renewable energy plants have an environmental footprint that has to be evaluated to quantify the real impact of renewable technologies on the environment. Nowadays, the most important tool to evaluate this impact of a product is the Life Cycle Assessment (LCA).Ingeniería Industria

Multifunctional enzymatically generated hydrogels for chronic wound application

The healing of chronic wounds requires intensive medical intervention at huge healthcare costs. Dressing materials should consider the multifactorial nature of these wounds comprising deleterious proteolytic and oxidative enzymes and high bacterial load. In this work, multifunctional hydrogels for chronic wound application were produced by enzymatic cross- linking of thiolated chitosan and gallic acid. The hydrogels combine several beneficial to wound healing properties, controlling the matrix metalloproteinases (MMPs) and myeloperoxidase (MPO) activities, oxidative stress, and bacterial contamination. In vitro studies revealed above 90% antioxidant activity, and MPO and collagenase inhibition by up to 98 and 23%, respectively. Ex vivo studies with venous leg ulcer exudates confirmed the inhibitory capacity of the dressings against MPO and MMPs. Additionally, the hydrogels reduced the population of the most frequently encountered in nonhealing wounds bacterial strains. The stable at physiological conditions and resistant to lysozyme degradation hydrogels showed high biocompatibility with human skin fibroblastsPeer ReviewedPostprint (author's final draft

Decision-Theoretic Planning with Person Trajectory Prediction for Social Navigation

Robots navigating in a social way should reason about people intentions when acting. For instance, in applications like robot guidance or meeting with a person, the robot has to consider the goals of the people. Intentions are inherently nonobservable, and thus we propose Partially Observable Markov Decision Processes (POMDPs) as a decision-making tool for these applications. One of the issues with POMDPs is that the prediction models are usually handcrafted. In this paper, we use machine learning techniques to build prediction models from observations. A novel technique is employed to discover points of interest (goals) in the environment, and a variant of Growing Hidden Markov Models (GHMMs) is used to learn the transition probabilities of the POMDP. The approach is applied to an autonomous telepresence robot

La protección multinivel de los derechos económicos, sociales y culturales: una mirada al derecho a la salud en el Sistema Interamericano de protección de los derechos humanos

Artículo de reflexiónEste documento presenta algunos comentarios en torno a la teoría de la protección multinivel de los derechos humanos, aplicada a la exigibilidad del derecho a la salud ante el Sistema Interamericano de Protección de los Derechos Humanos. Luego de presentar conceptualmente la protección multinivel, el documento expone una clasificación de algunas posiciones teóricas con base en los Modelos Analíticos para la Protección Multinivel y defiende la idea de que la exigibilidad del derecho a la salud en América Latina, implica la articulación de normas, procedimientos y estructuras, a partir del reconocimiento de los principios y objetivos constitucionales comunes entre el derecho nacional y regional.PregradoAbogad

Las redes sociales, actor en la difusión de información política

En un mundo globalizado, la información es uno de los recursos más importantes con los que cuenta la sociedad para tomar decisiones. Los avances tecnológicos permiten a los ciudadanos acceder desde cualquier lugar y sin gran esfuerzo a grandes cantidades de información con la cual ellos toman decisiones importantes en materia de política y economía. Sin embargo, estas decisiones están amenazadas por la circulación de noticias falsas o fake news, las cuales se comparten con la gran velocidad de Internet, a través de las redes sociales, lo que puede permitir la manipulación de los ciudadanos y la pérdida de su autonomía. Por eso, este trabajo presenta un análisis relacionado al impacto de las redes sociales en la difusión de información. Asimismo, busca analizar la influencia de las también llamadas fake news con base en las principales noticias mundiales y algunas regulaciones establecidas con el fin de proponer recomendaciones para implementar en el ámbito político colombiano.In a globalized world, information is one of the most important resources that society has to make decisions. Technological advances allow citizens to access, from any place and without great effort, large amounts of information with which they make important decisions regarding politics and economy. However, the circulation of fake news or fake news threatens these decisions, which are shared with the high speed of the Internet, through social networks; this may allow the manipulation of citizens and the loss of their autonomy. Therefore, this document presents an analysis related to the impact of the social networks in the dissemination of information. As well, it aims to analyze the influence of the fake news based on the main political news worldwide, and the established regulations by proposing some recommendations to implement in the political Colombian context1. Redes sociales: Principal difusor de noticias falsas o fake news. –2 . Las noticias pueden constituir un riesgo para el acceso a la información. – 3. Las noticias falsas en el contexto político. –4. Conclusiones. – 5. Agradecimientos. – 6. Referencias. – 7. Anexos

Is the Godfather of Mexico's Drug Trade Back in Business?

The founder of Mexico's notorious and now defunct Guadalajara Cartel, Rafael Caro Quintero, has been linked to two recent events that have raised alarm among authorities three years after a controversial court ruling freed the veteran drug lord and current fugitive from prison. Sorting out fact from fiction is rarely easy when it comes to matters of organized crime. But if the central government's intelligence is true to its name, it does appear that Caro Quintero, despite 28 years behind bars, has maintained a variety of contacts and networks in the drug trafficking world. In a criminal landscape that is characterized by a multitude of actors and continuous shifting of alliances, the "narco of narcos" appears to be in an advantageous position

Mexico's Military Follow Their Own Rules in the "Drug War"

Several incidents in the last few weeks have raised additional doubts over how Mexico's soldiers are approaching the so-called "drug war." Not only are there questions over how appropriately the security forces react in confrontations with civilians, but the importance of the military itself in Mexico's democracy may yet come under scrutiny