• Energy Research
• 2021-2025close
• CO close
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(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.

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

Frozen food is exposed to inevitable temperature changes during its storage, transport, and at the point of sale, which implies a significant impact on its properties and quality. Thus, the study of the effect of the formation of crystals on both the surface of the meat and the container when it is kept frozen, involving the thermodynamic analysis and changes that occurred at the structural level, is necessary. In this research, pork meat from Longissimus thoracis muscle was used, which was cut into plates and packed with two types of food-grade films: (1) Polyvinyl Chloride (PVC) and (2) low-density polyethylene (LDPE). Samples were frozen by indirect contact with nitrogen up to −40 ± 0.5 °C and subsequently stored at −20 ± 1 °C in a chamber from 0 to 15 days. The frost thickness was evaluated by the image superposition method. FTIR spectra were obtained by means of an Attenuated Total Reflectance (ATR) accessory, and thermal changes were determined by Modulated Differential Scanning Calorimetry (MDSC). It was found that the thickness of the frost on the surface of the meat is less when it is packaged with PVC due to the characteristics of the polymer matrix of the package. Furthermore, there were important changes at the molecular level identified by FTIR and MDSC, indicating significant differences (p < 0.05) between the samples. In general, PVC films were more stable at lower temperatures, allowing a small number of changes in the meat surface due to temperature fluctuations.

Most of the world’s mountain glaciers have been retreating for more than a century in response to climate change. Glacier retreat is evident on all continents, and the rate of retreat has accelerated during recent decades. Accurate, spatially explicit information on the position of glacier margins over time is useful for analyzing patterns of glacier retreat and measuring reductions in glacier surface area. This information is also essential for evaluating how mountain ecosystems are evolving due to climate warming and the attendant glacier retreat. Here, we present a non-comprehensive spatially explicit dataset showing multiple positions of glacier fronts since the Little Ice Age (LIA) maxima, including many data from the pre-satellite era. The dataset is based on multiple historical archival records including topographical maps; repeated photographs, paintings, and aerial or satellite images with a supplement of geochronology; and own field data. We provide ESRI shapefiles showing 728 past positions of 94 glacier fronts from all continents, except Antarctica, covering the period between the Little Ice Age maxima and the present. On average, the time series span the past 190 years. From 2 to 46 past positions per glacier are depicted (on average: 7.8).

RESUMEN : La Unidad Gestión Ambiental y Social T&D Energía como parte de Empresas Públicas de Medellín busca trasmitir y distribuir energía en diferentes sectores de Colombia por medio de proyectos autorizados por autoridades ambientales; la Línea de Transmisión de energía a 230kV BELLO – GUAYABAL – ANCÓN también conocido como BGA cumple dicho objetivo en el tramo N-S del Valle de Aburrá, costado oriental. En el año 2021, fue presentado un requerimiento como resultado de una auditoría interna debido a un atraso significativo en la actualización de los datos en la plataforma M-Risk adquirida por parte de EPM para seguimiento y control de obligaciones ambientales, lo que inició un plan de acción por parte de la unidad con la finalidad de realizar las respectivas actualizaciones en la información documentada a diciembre 2021. Por medio de este proyecto se buscaba revisar y actualizar la plataforma M-Risk para la Línea de Transmisión de energía a 230kV BELLO – GUAYABAL – ANCÓN, para su desarrollo se realizó una previa revisión del estado del proyecto en la plataforma con lo que se logró diseñar una línea base de la información faltante e incompleta, consecuente a la identificación del estado de los compromisos para así darles el correcto cierre; teniendo una actualización a la fecha de la plataforma que permitió dar cumplimiento al requerimiento ya mencionado. La actualización permitió obtener así para el proyecto Línea de Transmisión de energía a 230kV BELLO – GUAYABAL – ANCÓN un total de 196 compromisos actualizados en plataforma de 90 que se encontraban en plataforma en un comienzo, lo cual representó un aumento del 117.78 %. Adicionalmente, se identificó un aumento del 123.08 % asociado a un cambio de 13 permisos hallados en el mes de octubre a 29 el mes de diciembre.

The production of lettuce has increased significantly due to the use of hydroponic systems that rely on substrates. Disposal and acquisition costs present problems, necessitating the identification of sustainable alternatives. The present study aimed to evaluate the use of Eichhornia crassipes (water hyacinth) dry matter in a substrate for the formation of lettuce seedlings. Water plants were collected to obtain their dry matter, and twelve mixtures were formed with Sphagnum and perlite. Mixtures with more water hyacinth dry matter exhibited greater water retention. However, these mixtures also lost water at a faster rate than those containing primarily Sphagnum dry matter did. Higher percentages of germination were detected in the mixtures with water hyacinth dry matter, but these seedlings also presented higher concentrations of proline, such as 16.0 µg mL−1. The mixtures with water hyacinth dry matter presented the highest ion concentrations, mainly at high levels of humidity. Mixtures with a high proportion of water hyacinth dry matter had a greater water retention capacity and a high percentage of lettuce seed that germinated. The mixtures with a higher proportion of Sphagnum led to greater root length, greater concentrations of chlorophyll in cotyledonary leaves, and better morphological development of the seedlings.

High nutrient discharge from groundwater (GW) into surface water (SW) have multiple undesirable effects on river water quality. With the aim to estimate the impact of anthropic pressures and river–aquifer interactions on nitrate status in SW, this study integrates two hydrological simulation and water quality models. PATRICAL models SW–GW interactions and RREA models streamflow changes due to human activity. The models were applied to the Júcar River Basin District (RBD), where 33% of the aquifers have a concentration above 50 mg NO3−/L. As a result, there is a direct linear correlation between the nitrate concentration in rivers and aquifers (Júcar r2 = 0.9, and Turia r2 = 0.8), since in these Mediterranean basins, the main amount of river flows comes from groundwater discharge. The concentration of nitrates in rivers and GW tends to increase downstream of the district, where artificial surfaces and agriculture are concentrated. The total NO3− load to Júcar RBD rivers was estimated at 10,202 tN/year (239 kg/km2/year), from which 99% is generated by diffuse pollution, and 3378 tN/year (79 kg/km2/year) is discharged into the Mediterranean Sea. Changes in nitrate concentration in the RBD rivers are strongly related to the source of irrigation water, river–aquifer interactions, and flow regulation. The models used in this paper allow the identification of pollution sources, the forecasting of nitrate concentration in surface and groundwater, and the evaluation of the efficiency of measures to prevent water degradation, among other applications.