18 research outputs found

    Optimal Microgrid Topology Design and Siting of Distributed Generation Sources Using a Multi-Objective Substrate Layer Coral Reefs Optimization Algorithm

    Get PDF
    n this work, a problem of optimal placement of renewable generation and topology design for a Microgrid (MG) is tackled. The problem consists of determining the MG nodes where renewable energy generators must be optimally located and also the optimization of the MG topology design, i.e., deciding which nodes should be connected and deciding the lines’ optimal cross-sectional areas (CSA). For this purpose, a multi-objective optimization with two conflicting objectives has been used, utilizing the cost of the lines, C, higher as the lines’ CSA increases, and the MG energy losses, E, lower as the lines’ CSA increases. To characterize generators and loads connected to the nodes, on-site monitored annual energy generation and consumption profiles have been considered. Optimization has been carried out by using a novel multi-objective algorithm, the Multi-objective Substrate Layers Coral Reefs Optimization algorithm (Mo-SL-CRO). The performance of the proposed approach has been tested in a realistic simulation of a MG with 12 nodes, considering photovoltaic generators and micro-wind turbines as renewable energy generators, as well as the consumption loads from different commercial and industrial sites. We show that the proposed Mo-SL-CRO is able to solve the problem providing good solutions, better than other well-known multi-objective optimization techniques, such as NSGA-II or multi-objective Harmony Search algorithm.This research was partially funded by Ministerio de Economía, Industria y Competitividad, project number TIN2017-85887-C2-1-P and TIN2017-85887-C2-2-P, and by the Comunidad Autónoma de Madrid, project number S2013ICE-2933_02

    Herramientas Software para Enseñanzas Relacionadas con la Energía Solar Fotovoltaica

    Full text link
    [EN] This paper describes different simulation tools developed in the Universidad de Alcalá in order to teach photovoltaic energy engineering. A web application is compared to other tools, such as spreadsheets and applications in Matlab environment, developed by the authors. In all the cases, the tools are focused on learning project engineering.[ES] En este trabajo, se describen diferentes herramientas de simulación empleadas en asignaturas de la Universidad de Alcalá para la enseñanza de la energía solar fotovoltaica. Se compara el uso de una aplicación web con otras herramientas como hojas de cálculo y aplicaciones en entorno Matlab. Todas las herramientas descritas han sido desarrolladas por los autores, haciendo especial énfasis en su enfoque didáctico, sin por ello perder todo el rigor y la funcionalidad necesarios en este tipo de simuladores.Peña Capilla, R.; García Díaz, M.; Alén Cordero, C.; Díaz Villar, P.; Mallol Poyato, R.; Díez-Pascual, A. (2017). Herramientas Software para Enseñanzas Relacionadas con la Energía Solar Fotovoltaica. En In-Red 2017. III Congreso Nacional de innovación educativa y de docencia en red. Editorial Universitat Politècnica de València. 1311-1321. https://doi.org/10.4995/INRED2017.2017.6862OCS1311132

    Relative telomere length impact on mortality of COVID-19: Sex differences

    Get PDF
    Increasing age is associated with severity and higher mortality of COVID-19. Telomere shortening is associated with higher risk of infections and may be used to identify those patients who are more likely to die. We evaluated the association between relative telomere length (RTL) and COVID-19 mortality. RTL was measured in patients hospitalized because of COVID-19. We used Kaplan-Meier method to analyze survival probabilities, and Cox regression to investigate the association between RTL and mortality (30 and 90 days). Six hundred and eight patients were included in the analysis (mean age =72.5 years, 41.1% women, and 53.8% Caucasic). During the study period, 75 people died from COVID-19 and 533 survived. Lower RTL was associated with a higher risk of death in women either at 30 (adjusted hazard ratio [HR] (aHR) = 3.33; 95% confidence interval [CI] = 1.05-10.00; p = 0.040) and at 90 days (aHR = 3.57; 95%CI = 1.23-11.11; p = 0.019). Lower RTL was associated with a higher risk of dying of COVID-19 in women. This finding suggests that RTL has an essential role in the prognosis of this subset of the population.This study was supported by grants from Instituto de Salud Carlos III (ISCIII; grant number COV20/1144 [MPY224/20] to AFR/MAJS) and Fundación Universidad Alfonso X el Sabio (FUAX) – Santander (1.013.005). MAJS is Miguel Servet researcher supported and funded by ISCIII (grant number: CP17CIII/00007). The study was also supported by the Centro de Investigación Biomédica en Red (CIBER) en Enfermedades Infecciosas (CB21/13/00044). We also acknowledge the Spanish Coalition to Unlock Research on Host Genetics on COVID‐19 (SCOURGE).S
    corecore