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Ultrarich filtration combustion of ethane is studied in a porous medium composed of alumina spheres with the aim to achieve optimized conversion to hydrogen and syngas. Temperature, velocities, and...

Teniendo en cuenta el Proyecto Educativo de los Programas (PEP) de la Universidad Militar Nueva Granada (UMNG) en consideración al programa grupos y líneas de investigación existentes en el Departamento de Ciencias Básicas que soportan el programa de Ingeniería Ambiental, Ingeniería Mecatrónica y Medicina (UMNG, 2019), como para el (PEP) de postgrado Especialización en Planeación Ambiental y Manejo Integral de los Recursos Naturales (UMNG, 2019), se propone el estudio de la climatología espacial en el entorno experimental de la física de partículas con base en los proyectos existentes en el sector académico e institucional internacional, específicamente para la radiación cósmica de fondo primaria y secundaria, haciendo énfasis en la segunda debido a su importancia en la troposfera terrestre que hace parte del estudio de las Ciencias Ambientales, bajo las implicaciones que inciden en la salud pública, los ecosistemas, la biodiversidad, el cambio climático y la variabilidad climática, como también las potenciales aplicaciones en el campo del monitoreo y análisis del suelo, agua y aire. ; Resumen Introducción Materiales y Métodos Resultados y Discusiones Conclusiones Bibliografía Lista de Imagenes ; Taking into account the educational project of the programs (PEP) of the Universidad Militar Nueva Granada (UMNG) in consideration of the program existing groups and lines of research in the Department of Basic Sciences that support the program of Ingeniería Ambiental, Ingeniería Mecatrónica and Medicina (UMNG, 2019), as for the (PEP) specialization in Planeación Ambiental y Manejo Integral de los Recursos Naturales (UMNG, 2019), proposes the study of space climatology in the experimental of particle physics whit based on existing projects in the international academic and institutional sector, specifically for primary and secondary cosmic background radiation, emphasizing the second due to its importance in the terrestrial troposphere that is part of the study of the Environmental Sciences, under the implications that ...

Abstract A bilinear proportional-integral (PI) controller based on passivity-based formulations for integrating superconducting magnetic energy storage (SMES) devices to power ac microgrids is proposed in this paper. A cascade connection between a dc–dc chopper and a voltage source converter is made to integrate the SMES system. The proposed controller guarantees asymptotically stability in the Lyapunov's sense under closed-loop operation. This controller exploits the well-known advantages of the proportional-integral (PI) actions via passivation theory. Active and reactive power compensation in the ac system through the SMES integration is proposed as the control objective. To achieve this goal, a radial ac distribution feeder with high penetration of distributed energy resources and time-varying loads is employed. The effectiveness and the robustness of the proposed bilinear PI controller verified by comparing its dynamical performance to conventional approaches such as conventional PI and feedback controllers. All simulation results are conducted via MATLAB/SIMULINK software by using SimPowerSystem library.

(1)Background: Evidence on the association between air pollution and the risk of exacerbations of chronic obstructive pulmonary disease (COPD) is scarce and inconsistent. We aimed to analyze the association between long-term exposure to particulate matter with a diameter of less than 2.5 µm (PM2.5) and nitrogen dioxide (NO2) and exacerbation of COPD (COPD-E) in Bogotá, Colombia; (2) Methods: Retrospective cohort study of 722 COPD patients in the AIREPOC program of the Colombian Pneumological Foundation between 2018 and 2021. Exposure to PM2.5 and NO2 was estimated for residential locations using the inverse squared distance weighted regression (IDWR) method. Hazard Ratios (HR) were calculated for the first COPD-E during follow-up using Cox models, adjusted for meteorological, demographic, and clinical variables; (3) Results: COPD-E was associated with long-term exposure to PM2.5 (HR:1.03, 95%CI: 1.02-1.05) and NO2 (HR:1.05, 95%CI: 1.03-1.07) controlling for the effect of quality of life, history of COPD-E, Forced Expiratory Volume in One Second (FEV1) pre-bronchodilator and exposure to solar radiation. An association was found between COPD-E and concentrations ≥ 25µg/m3 of NO2 (HR:1.49, 95%CI: 1.12-1.98) but not with concentrations ≥15 µg/m3 of PM2.5; (4) Conclusions: This study suggests that people with COPD exposed to higher concentrations of PM2.5 and NO2 had an increased risk of COPD-E. Solar radiation was also associated with an increased risk of COPD-E. The results highlight the importance of continuing efforts to reduce air pollution.

Abstract Conventional spouted beds have been extensively used in many real-life applications but are not suited for all types of materials, especially fine particles, which require internal devices to improve their motion in the spouted bed. However, unlike conventional spouted beds, there are almost no mechanistic or empirical models available for the design of spouted beds with internals. Given the availability of an extensive but not experimentally designed database, the main purpose of this study is to present an analysis of neural networks and empirical models in terms of their suitability to fit and predict average cycle times in conical spouted beds with and without draft tubes. The parameters investigated are particle size, density, contactor angle, gas inlet diameter, static bed height, and draft tube features. Although the amount of information is always a key factor when fitting models, the size of the database used in this study strongly affects the fitting performance of empirical models, whereas artificial neural networks are more influenced by how the data are scaled. Results of model verification show that both techniques are suitable for predicting average cycle times for data outside the range covered by the database.

This study evaluate the effects of different types of agricultural systems and their managements on energy balance over 45-year period (1970–2015). Agricultural systems were (i) spring barley and (ii) winter wheat monocultures with different types of organic supply (straw incorporation, straw incorporation + green manuring, green manuring and control without organic supply) and (iii) Norfolk four-course system. Averaged across each half of study period, total energy inputs ranged between 10.2 GJ ha-1 year-1 for barley in Norfolk to 22.9 GJ ha-1 year-1 for wheat in monoculture with green manuring. The results indicate increase of indirect inputs in case of wheat and barley in Norfolk. The only system where the indirect input energy became lower was barley monoculture. Total energy outputs ranged between 198 GJ ha-1 year-1 for wheat in Norfolk to 88 GJ ha-1 year-1 for barley in monoculture. Norfolk system had higher output/input ratio than monocultures during whole study period. In almost all systems the effectiveness of energy use decreased during study period when comparing two halves. Yields of cereals throughout all systems were negatively dependent on energy input.

El propósito de esta investigación se fundamentó en realizar el análisis del comportamiento de los datos de velocidad y dirección del viento del caso en estudio propuesto. Se desarrolló el análisis mediante la función de distribución de Rayleigh y su comparativo con la metodología Weilbull para los cálculos, estimación de la densidad de potencia y el poder de generación potencial del viento a través de un autogenerador determinado. Adicionalmente, se graficó mediante el Diagrama de Rosa de Viento la dirección recomendada tendiente a proponer la mejor ubicación en la instalación del sistema de generación. ; The purpose of this research was based on the analysis of the behavior of the wind speed and direction data of the proposed case study. The analysis was developed using the Rayleigh distribution function and its comparison with the Weilbull methodology for the calculations, estimation of the power density and the potential generation power of the wind through a given autogenerator. Additionally, the recommended direction was plotted by means of the Wind Rose Diagram to propose the best location for the installation of the generation system.

La llegada de las nuevas tecnologías y su aplicación en la ingeniería civil, ha permitido una mirada más transversal de sus aplicaciones; es por ello que, en el siguiente ensayo se propone un novedoso sistema flotante fotovoltaico con el fin de suministrar energía eléctrica en el alto Baudó, el cual permite aprovechar la energía solar y así poder llevar el servicio de energía a la población, esta tecnología en el poco tiempo que lleva de aplicación ha demostrado ser una de las soluciones más amigables y efectivas, al mismo tiempo suministrar los servicios básicos a la comunidad. ; The arrival of new technologies and their application in civil engineering has allowed a more transversal view of their applications; That is why, in the following essay, a novel photovoltaic floating system is proposed in order to supply electrical energy in the upper Baudó, which allows taking advantage of solar energy and thus being able to bring the energy service to the population, this technology in the short time it has been in place has proven to be one of the friendliest and most effective solutions, at the same time providing basic services to the community ; Pregrado

In the Czech Republic, as a follow-up, a consortium of research organizations and universities has decided to simulate selected stress tests’ scenarios, in station blackout (SBO) and the loss of ultimate heat sink (LoUHS), with the aim to verify the national stress report and to analyze time response of respective source term releases. These activities are carried out in the frame of the project prevention, preparedness, and mitigation of consequences of severe accident (SA) at Czech NPPs in relation to lessons learned from stress tests after Fukushima, financed by the Ministry of Interior. The Research Centre Rez has been working on a methods for estimation of leakages and consequences of releases (MELCOR) model for VVER1000 nuclear power plant (NPP) starting with a plant systems nodalization. The aim was to benchmark the MELCOR model with the validated TRAC/RELAP advanced computational engine (TRACE) model, first comparing the steady state and continuing in a long-term SBO plus another event until the beginning of the SA. The presented work is based on the previous paper from the ICONE 23rd Conference hosted in Japan. It focuses mainly on the comparison of the thermohydraulics of the two models created in MELCOR and TRACE codes as outcome of the “Fukushima project.” After that, preliminary general results of the SA progression showing the hydrogen production and the relocation phenomena will be shortly discussed. This scenario is considered closed after some seconds to the break of the lower head. It is important to note that this paper is a substantial update of a previous one (Mazzini et al., 2015, “Analyses of SBO Sequence of VVER1000 Reactor Using TRACE and MELCOR Codes,” 23rd International Conference on Nuclear Engineering (ICONE23)) and although it contains the same descriptive sections, all the results are new.

Spinel LiNi0.5Mn1.5O4 as one of the high-energy positive electrode materials for next generation Li-ion batteries has attracted significant interest due to its economic and environmental advantages. However, the sensitivity of this type of material upon short to long term ambient storage conditions and the impact on the electrochemical performances remains poorly explored. Nevertheless, this remains an important aspect for practical large-scale synthesis, storage and utilization. Herein, we study and compare the evolution of surface chemistry, bulk crystal structure and elemental content evolution and distribution of LiNi0.5Mn1.5O4 using a variety of characterization techniques including XPS and STEM-EDS-EELS, as well as electrochemical analysis. We show that Mn species dominate the outer surface (0–5 nm), while Ni and Li are preferentially located further away and in the bulk. The studied LiNi0.5Mn1.5O4 material is found to be stable, with minor changes in surface or bulk characteristics detected, even after 12 months of storage under ambient air conditions. The low surface reactivity to air also accounts for the minor changes to the electrochemical performance of the air-exposed LiNi0.5Mn1.5O4, compared to the pristine material. This study provides guidance for the appropriate storage, handling and processing of this high-performance cathode material.