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description Publicationkeyboard_double_arrow_right Article 2021Publisher:Taiwan Association for Aerosol Research Authors: Heli A. Arregocés; Roberto Rojano; Gloria Restrepo;Heli A. Arregocés; Roberto Rojano; Gloria Restrepo;doi: 10.4209/aaqr.200664
ABSTRACT Particulate matter (PM) is the main pollutant produced by open-pit mining operations, and its emission into the atmosphere is strongly associated with adverse health effects in the surrounding communities. The objective of this study was to evaluate the effects of the COVID-19-related lockdown on the PM concentrations in the North, Central, and South Zones of Cerrejon, Colombia, the largest open-pit coal mine in Latin America. To compare the levels before and during the emergency shutdown, we analyzed both the ground-based daily PM10 and PM2.5 data and the satellite (Terra/Aqua MODIS)-based daily aerosol optical depth (AOD) values from March 6 through April 13, 2020. The average PM10 concentrations in the North and South Zones, in contrast to those observed at other global monitoring sites, increased by 13–38% and 4–7%, respectively, although they decreased by 26–31% in the Central Zone, between the pre-lockdown and lockdown periods. Furthermore, during the latter, the daily PM2.5 levels in the South Zone rose by up to 43%, and we found higher AOD values (≥ 0.4) over the Central and South Zones as well as significant AOD-contributing loads upwind and downwind of the coal production pits. Finally, the increases in humidity and temperature (≥ 3.5% and ≥ 0.3 K, respectively), decrease in planetary boundary layer height (≥ 0.11 km), wind field variability, and rural biomass burning events shaped the spatial-temporal behavior of the PM in this region, and changes in meteorology and external sources nearly offset the reduction in emissions from mining activities. These results establish a baseline for developing future regulations and mitigation plans.
add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.4209/aaqr.200664&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesgold 6 citations 6 popularity Top 10% influence Average impulse Top 10% Powered by BIP!more_vert add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.4209/aaqr.200664&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2014 ColombiaPublisher:Universidad Nacional de Colombia Authors: Enrique Muñoz; Pedro Tume; Gabriel Ortíz;Enrique Muñoz; Pedro Tume; Gabriel Ortíz;<p>As hydrological models become more prevalent in water resources planning and management, increasing levels of detail and precision are needed. Currently, reliable models that simulate the hydrological behavior of a basin are indispensable; however, it is also necessary to know the limits of the predictability and reliability of the model outputs. The present study evaluates the influence of uncertainty in the main input variable of the model, rainfall, on the output uncertainty of a hydrological model. Using concepts of identifiability and sensitivity, the uncertainty in the model structure and parameters was estimated. Then, the output uncertainty caused by uncertainties in i) the rainfall amounts and ii) the periods of the rainfall was determined. The main conclusion is that uncertainty in rainfall estimation during rainy periods produces greater output uncertainty. However, in non-rainy periods, the output uncertainty is not very sensitive to the uncertainty in rainfall. Finally, uncertainties in rainfall during the basin filling and emptying periods (Apr. – Jun. and Sep. – Nov., respectively) alter the uncertainty in subsequent periods. Therefore, uncertainties in these periods could result in limited ranges of model predictability.</p><p> </p><p><strong>Resumen</strong></p><p>Los modelos hidrológicos se han vuelto cada vez más necesarios en la planificación y gestión de recursos hídricos, donde un aumento en los niveles de detalle y precisión es necesario. Actualmente disponer de modelos para simular el comportamiento hidrológico de una cuenca resulta indispensable, sin embargo, también es necesario conocer los límites de predictibilidad y de confiabilidad de las salidas de un modelo. En este estudio se evalúan la influencia de la incertidumbre en la principal entrada de un modelo, la precipitación, sobre la incertidumbre de las salidas de un modelo hidrológico. Utilizando conceptos de identificabilidad y sensibilidad se estima la incertidumbre de los parámetros y estructura de un modelo. Luego, la incertidumbre en las salidas causadas por incertidumbre en i) los montos de precipitación, ii) los períodos de precipitación fue calculada. Como conclusiones se obtuvo que la incertidumbre en la estimación de la precipitación en períodos de lluvia produce mayor incertidumbre sobre las salidas. En períodos no lluviosos, la incertidumbre de las salidas es poco sensible a incertidumbre sobre las precipitaciones. Finalmente, incertidumbres en periodos de llenado y vaciado (Abril-Junio y Septiembre-Noviembre respectivamente) afectan la incertidumbre en las salidas en los períodos subsecuentes. Por lo tanto incertidumbres en aquellos períodos pueden resultar en rangos limitados de predictibilidad de un modelo.</p>
LAReferencia - Red F... arrow_drop_down Scientific Electronic Library Online - ColombiaArticle . 2014License: CC BYData sources: Scientific Electronic Library Online - Colombiaadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.15446/esrj.v18n1.38760&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesgold 8 citations 8 popularity Average influence Average impulse Average Powered by BIP!more_vert LAReferencia - Red F... arrow_drop_down Scientific Electronic Library Online - ColombiaArticle . 2014License: CC BYData sources: Scientific Electronic Library Online - Colombiaadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.15446/esrj.v18n1.38760&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2014 ColombiaPublisher:Universidad Nacional de Colombia Authors: Álvarez-Álvarez, Carlos Mauricio; Arias-Quintero, Carlos Andrés; Builes-Carvajal, Juan Sebastián; Ordoñez-Carmona, Oswaldo; +1 AuthorsÁlvarez-Álvarez, Carlos Mauricio; Arias-Quintero, Carlos Andrés; Builes-Carvajal, Juan Sebastián; Ordoñez-Carmona, Oswaldo; Zapata-Madrigal, Germán Darío;La investigación pretende identificar las variables que influyen en el aumento de riesgos por explosiones en minas de carbón subterráneas, especialmente en la acumulación del polvo de carbón en la parte superior de los sostenimientos, además de analizar cómo influyen estos en las pérdidas de carga del circuito de ventilación y la correcta evacuación del polvo de carbón. Dicho análisis se realizó mediante visitas guiadas de campo a la Mina Nechí (Municipio de Amagá, Antioquia) donde se observó que el polvo de carbón se acumula más significativamente en las puertas de madera que en los arcos de acero, se procedió a simular diferentes geometrías del sostenimiento y la cantidad de estos con el fin de determinar cuál geometría contribuye a disminuir las pérdidas de carga. Una vez analizados los diferentes escenarios, la geometría que optimiza el circuito de ventilación es la que se ha denominado geometría Circular 2, la cual presenta reducciones en las pérdidas de carga de hasta un 14.67% respecto a las otras geometrías analizadas bajo las mismas condiciones. Con esto se proponen alternativas más eficientes para optimizar el circuito de ventilación y garantizar condiciones de higiene y seguridad para los trabajadores al interior de las minas. The research aims to identify the variables which influence on the increase of risk for explosions in underground coal mines, especially in the accumulation of coal dust on top of the fortification, as well as analyze how these affect the load losses in the ventilation circuit and the proper evacuation of coal dust. This analysis was carried out by a guide field visits to Nechí Mine (Municipality Amagá, Antioquia) where it was observed that the coal dust accumulated significantly in the wooden doors that in the steel arches, we proceeded to simulate different geometries of fortification and the amount of these for the purpose to determine which is the geometry that contributes to reducing the load losses. After analyzing the different scenarios, the geometry that optimizes the ventilation circuit has been called geometry Circular 2, which shows reduction in load losses of up to 14.67% compared to other geometries analyzed under the same conditions. Whit this, are proposed alternatives more efficient to optimize the ventilation circuit and ensure health and safety conditions for workers inside the mine.
Boletín de Ciencias ... arrow_drop_down Scientific Electronic Library Online - ColombiaArticle . 2014License: CC BY NC NDData sources: Scientific Electronic Library Online - ColombiaBoletín de Ciencias de la TierraArticle . 2014 . Peer-reviewedLicense: CC BY NC NDData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.15446/rbct.n36.45519&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesgold 1 citations 1 popularity Average influence Average impulse Average Powered by BIP!more_vert Boletín de Ciencias ... arrow_drop_down Scientific Electronic Library Online - ColombiaArticle . 2014License: CC BY NC NDData sources: Scientific Electronic Library Online - ColombiaBoletín de Ciencias de la TierraArticle . 2014 . Peer-reviewedLicense: CC BY NC NDData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.15446/rbct.n36.45519&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2013Publisher:Instituto Colombiano del Petroleo Authors: Juan Pablo Gómez Montoya; Karen Paola Cacua Madero; Layrisser Iral Galeano; Andrés Amell Arrieta;Juan Pablo Gómez Montoya; Karen Paola Cacua Madero; Layrisser Iral Galeano; Andrés Amell Arrieta;doi: 10.29047/01225383.57
The effect of hydrogen enrichment was tested for a diesel-biogas dual fuel engine. The operation and performance characteristics, such as thermal efficiency, pollutant emissions and combustion parameters were determined. Experiments have been carried with a stationary compression ignition (CI) engine coupled with a generator in dual mode using a typical biogas composition of 60% vol. CH4 and 40% vol. CO2. For every load engine evaluated, the hydrogen concentration was varied from 5 to 20% H2 v/v. The results showed increases in peak pressure chamber up to 10.7 bar, and diesel substitution levels up to 80% under conditions of steady combustion without knocking. Also, thermal efficiency increases up to 16% and carbon monoxide emissions decreases up to 13% at full load, and 20% of hydrogen in engines operating in diesel-biogas dual mode.
add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.29047/01225383.57&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesgold 11 citations 11 popularity Top 10% influence Average impulse Average Powered by BIP!more_vert add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.29047/01225383.57&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2011 SpanishPublisher:Instituto Nacional de Salud Authors: Herrera, Astrid B; Rodríguez, Laura A; Niederbacher, Jürg;Herrera, Astrid B; Rodríguez, Laura A; Niederbacher, Jürg;Introducción. La contaminación en el hogar puede desempeñar un papel importante en el desarrollo y exacerbación del asma infantil, sobre todo entre niños genéticamente predispuestos. Objetivos. Evaluar la asociación entre la presencia de contaminantes biológicos intradomiciliarios y síntomas indicativos de asma, en preescolares de Bucaramanga, Colombia Materiales y métodos. Se hizo un estudio de corte transversal analítico, en menores de 7 años, en dos zonas de la ciudad con niveles diferentes de contaminación atmosférica por material particulado. Se evaluaron los síntomas respiratorios indicativos de asma y los contaminantes intradomiciliarios mediante cuestionarios previamente validados, las mediciones biológicas de ácaros y hongos por métodos de laboratorio estandarizados, y se usó el modelo log binomial para el análisis multivariado, que permitió evaluar asociaciones mediante la estimación de las razones de prevalencia. Resultados. Participaron 678 niños, con edad media de 42 meses. La prevalencia de síntomas respiratorios indicativos de asma fue 8,0 % (IC95%: 5,6-9,6), sin diferencias significativas entre las dos zonas de contaminación extradomiciliaria. El modelo binomial mostró que los síntomas de asma se asociaron con la presencia de: ácaros razón de prevalencia (RP)=1,78; IC95%: 1,0-3,0 y Acremonium sp. (RP=6,2; IC95%: 3,8-10,0), y antecedentes de neumonía (RP=4,0; IC95%: 2,5-6,4), de rinitis alérgica (RP=1,9; IC95%: 1,25-3,1), de prematuridad (RP=3,4; IC95%: 1,7-6,5), de padres con asma (RP=2,6; IC95%: 1,4-5,0) y de tenencia de mascotas (RP=0,4; IC95%: 0,2-0,9). Conclusiones. La exposición a contaminantes biológicos intramurales (ácaros y hongos), los antecedentes personales de prematuridad, neumonía o rinitis y el antecedente familiar de asma, incrementan la probabilidad de presentación de síntomas indicativos de asma bronquial en la población estudiada. Introduction. Indoorair pollution may play an important role in development and exacerbation of asthma in children. Objective. The association between the presence of indoor biological contaminants and respiratory symptoms related to asthma was assessed in preschool children. Materials and methods. This cross-sectional study was undertaken in Bucaramanga, Colombia, and included children <7 years of age living in two urban areas of with different levels of outdoor air pollution. The 678 children were an average of 3.5 years of age. Respiratory symptoms indicative of asthma and indoor air pollutants were assessed by previously validated questionnaires.. Biological samples potentially containing mites and fungi were collected by standardized laboratory methods. The log binomial regression model was used for multivariate analysis, using adjusted prevalence ratios (PR). Results. The prevalence of asthmatic respiratory symptoms was 8.0%; (95% C.I: 5.6-9.6), without significant differences between the two areas. Binomial model analysis showed that asthma symptoms were associated with mites (PR 1.78; 95% C.I. 1.0-3.0), Acremonium sp (PR 6.24; 95 C.I.: 3.8-10.0) and a history of child pneumonia (PR 4.0; 95% C.I. 2.5-6.4), allergic rhinitis (PR 1.9; 95% C.I.: 1.2-3.1), prematurity (PR 3.4; 95% C.I. 1.8-6.5), parents with asthma (PR 2.6; 95% C.I. 1.4-5.0) and pet ownership (PR 0.4; 95% C.I. 0.2-0.9). Conclusions. The indoor exposure to biological contaminants (dust mites and fungi), history of prematurity, pneumonia, rhinitis and family history of asthma increased the occurence of symptoms suggestive of asthma in young children.
Scientific Electroni... arrow_drop_down Scientific Electronic Library Online - ColombiaArticle . 2011License: CC BYData sources: Scientific Electronic Library Online - ColombiaAll Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=od_______618::c3266576565d72f76f93ede50db3d9e6&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eu0 citations 0 popularity Average influence Average impulse Average Powered by BIP!more_vert Scientific Electroni... arrow_drop_down Scientific Electronic Library Online - ColombiaArticle . 2011License: CC BYData sources: Scientific Electronic Library Online - ColombiaAll Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=od_______618::c3266576565d72f76f93ede50db3d9e6&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2020Publisher:Saint Petersburg State University S. V. Lebedev; Stanislav V. Dubrova; Petr V. Fedorov; Willington Siabato; Vitalij V. Kurilenko;This paper presents the results of simulating the conditions of absorption of natural radionuclides (uranium-238, thorium-232, potassium-40) in different environment media (water and quartz sand) to assess the effect of the shielding properties of environmental components on the intensity of external radiation exposure to the benthic biota. The source of radiation was the lower Tremadocian Dictyonema shale, which formed the bottom of the Baltic Paleobasin. Water and quartz sand, which was gradually deposited on the roof of the Dictyonema shale, were used in the simulation as media (materials) absorbing the primary radiation. The manuscript shows an experiment conducted in full-scale conditions considering a single exposure of a section of Ordovician rocks that includes highly radioactive Dictyonema shale. This is a small area, but the simulation results are also valid for larger areas as the Baltic Paleobasin. During the late Tremadocian — Floian, along with transgression, benthic biota began to emerge. The experiment shows quantitatively what dosage this biota could have experienced over tens and hundreds of thousands of years, until the Dictyonema shale was covered with a sufficiently thick layer of water-flooded sediments. Experimental data show that the presence of a 10 cm thick layer of water reaches absorption of 40 % of the integral flux of all gamma lines of natural radionuclides (NRN), and in a moist quartz sand layer of the same thickness the absorption value does not exceed 50 %. Thus, despite the screening effect of the environment, the benthic biota of Baltoscandia in the Early Ordovician could have been under significant radiation exposure for millennia. The main value of the experiment is that it was performed in situ, and exclusively natural media were used as modelling elements.
Vestnik of Saint Pet... arrow_drop_down Vestnik of Saint Petersburg University Earth SciencesArticle . 2020 . Peer-reviewedData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.21638/spbu07.2020.101&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesgold 0 citations 0 popularity Average influence Average impulse Average Powered by BIP!more_vert Vestnik of Saint Pet... arrow_drop_down Vestnik of Saint Petersburg University Earth SciencesArticle . 2020 . Peer-reviewedData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.21638/spbu07.2020.101&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2014Publisher:Springer Science and Business Media LLC Funded by:FCT | LA 1, EC | VOLDIESFCT| LA 1 ,EC| VOLDIESSarah K. Brown; Helen Sian Crosweller; R. S. J. Sparks; Elizabeth Cottrell; Natalia I. Deligne; Natalie Ortiz Guerrero; Laura Hobbs; Koji Kiyosugi; Susan C. Loughlin; Lee Siebert; Shinji Takarada;The Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database contains data on 1,883 Quaternary eruption records of magnitude (M) 4 and above and is publically accessible online via the British Geological Survey. Spatial and temporal analysis of the data indicates that the record is incomplete and is thus biased. The recorded distribution of volcanoes is variable on a global scale, with three-quarters of all volcanoes with M≥4 Quaternary activity located in the northern hemisphere and a quarter within Japan alone. The distribution of recorded eruptions does not strictly follow the spatial distribution of volcanoes and has distinct intra-regional variability, with about 40% of all recorded eruptions having occurred in Japan, reflecting in part the country’s efforts devoted to comprehensive volcanic studies. The number of eruptions in LaMEVE decreases with increasing age, exemplified by the recording of 50% of all known Quaternary eruptions during the last 20,000 years. Historical dating is prevalent from 1450 AD to the present day, substantially improving record completeness. The completeness of the record also improves as magnitude increases. This is demonstrated by the calculation of the median time, T50, for eruptions within given magnitude intervals, where 50% of eruptions are older than T50: T50 ranges from 5,070 years for M4-4.9 eruptions to 935,000 years for M≥8 eruptions. T50 follows a power law fit, suggesting a quantifiable relationship between eruption size and preservation potential of eruptive products. Several geographic regions have T50 ages of <250 years for the smallest (~M4) eruptions reflecting substantial levels of under-recording. There is evidence for latitudinal variation in eruptive activity, possibly due to the effects of glaciation. A peak in recorded activity is identified at 11 to 9 ka in high-latitude glaciated regions. This is absent in non-glaciated regions, supporting the hypothesis of increased volcanism due to ice unloading around this time. Record completeness and consequent interpretation of record limitations are important in understanding volcanism on global to local scales and must be considered during rigorous volcanic hazard and risk assessments. The study also indicates that there need to be improvements in the quality of data, including assessment of uncertainties in volume estimates.
Journal of Applied V... arrow_drop_down add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1186/2191-5040-3-5&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesgold 91 citations 91 popularity Top 1% influence Top 10% impulse Top 10% Powered by BIP!visibility 3visibility views 3 download downloads 159 Powered bymore_vert Journal of Applied V... arrow_drop_down add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1186/2191-5040-3-5&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2019Publisher:Universidad EAFIT Authors: Ludger O. Suarez-Burgoa; Alvaro J. Castro-Caicedo;Ludger O. Suarez-Burgoa; Alvaro J. Castro-Caicedo;El presente artículo expone el procedimiento para lograr el modelo geométrico tridimensional de un macizo rocoso a partir de un par de tomas fotográficas hechas con una cámara corriente, uso de software libre/abierto como Octave y otras librerías libres, construcción de equipos y herramientas sencillos y la apropiación de conocimientos importantes en visión artificial. Se describe tomando como ejemplo el modelo tridimensional de un corte de voladura del macizo rocoso de la Cantera Santa Rita, localizada al sudoeste de la ciudad de Medellín (Colombia). Finalmente, se muestra mediante una validación, a partir de medidas de campo in situ, que el procedimiento descrito aquí es promisorio para que pueda instaurarse como una herramienta para la caracterización geométrica de discontinuidades de los macizos rocosos.
add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.17230/ingciencia.15.30.2&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess RoutesGreen gold 0 citations 0 popularity Average influence Average impulse Average Powered by BIP!more_vert add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
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For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Preprint , Article 2023Publisher:IOP Publishing Authors: Gabriel Narvaez; Michael Bressan; Andres Pantoja; Luis Felipe Giraldo;Gabriel Narvaez; Michael Bressan; Andres Pantoja; Luis Felipe Giraldo;Abstract This paper presents the first study of the long-term impact of climate change on photovoltaic potential in South America. This region has great potential for implementing renewable energy, mainly solar energy solutions, due to its high solar irradiance levels. Based on the Coordinated Regional Downscaling Experiment (CORDEX) for the South American region, we estimate how climate change could affect photovoltaic power potential by the end of the century. The evidence suggests that photovoltaic potential could have a maximum decrease of around 15%, and a maximum increase of approximately 7%, primarily due to changes in solar irradiance of different zones. Furthermore, it is observed that regions with increased temperature also show increased solar irradiance levels, which could, to some extent, compensate for the losses caused by the rise in temperature. Therefore, photovoltaic production in most of the territory will not be negatively affected.
arXiv.org e-Print Ar... arrow_drop_down Environmental Research CommunicationsArticle . 2023 . Peer-reviewedLicense: CC BYData sources: Crossrefhttps://doi.org/10.48550/arxiv...Article . 2023License: arXiv Non-Exclusive DistributionData sources: Dataciteadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1088/2515-7620/acf02e&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess RoutesGreen gold 0 citations 0 popularity Average influence Average impulse Average Powered by BIP!more_vert arXiv.org e-Print Ar... arrow_drop_down Environmental Research CommunicationsArticle . 2023 . Peer-reviewedLicense: CC BYData sources: Crossrefhttps://doi.org/10.48550/arxiv...Article . 2023License: arXiv Non-Exclusive DistributionData sources: Dataciteadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1088/2515-7620/acf02e&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2017Publisher:IOP Publishing Authors: J. A. García Zúñiga; A. Sarmiento Santos; E Y Soto Gómez;J. A. García Zúñiga; A. Sarmiento Santos; E Y Soto Gómez;1020 steel is a material very used for surface treatment in the abnormal glow discharge. Because the composition of the gaseous atmosphere has an important influence on the results of plasma treatment, in this work the oxidation process of 1020 steel is verified on the abnormal glow discharge under different concentrations of air (20% to 100%) at temperatures of 600°C and 900°C. For each atmosphere used mass variation is measured during the process of surface oxidation, the structure and microstructure of the oxide film formed is observed and also its mechanical properties through its microhardness.
Journal of Physics :... arrow_drop_down Journal of Physics : Conference SeriesArticle . 2017 . Peer-reviewedLicense: CC BYData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1088/1742-6596/786/1/012036&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesgold 0 citations 0 popularity Average influence Average impulse Average Powered by BIP!more_vert Journal of Physics :... arrow_drop_down Journal of Physics : Conference SeriesArticle . 2017 . Peer-reviewedLicense: CC BYData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
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description Publicationkeyboard_double_arrow_right Article 2021Publisher:Taiwan Association for Aerosol Research Authors: Heli A. Arregocés; Roberto Rojano; Gloria Restrepo;Heli A. Arregocés; Roberto Rojano; Gloria Restrepo;doi: 10.4209/aaqr.200664
ABSTRACT Particulate matter (PM) is the main pollutant produced by open-pit mining operations, and its emission into the atmosphere is strongly associated with adverse health effects in the surrounding communities. The objective of this study was to evaluate the effects of the COVID-19-related lockdown on the PM concentrations in the North, Central, and South Zones of Cerrejon, Colombia, the largest open-pit coal mine in Latin America. To compare the levels before and during the emergency shutdown, we analyzed both the ground-based daily PM10 and PM2.5 data and the satellite (Terra/Aqua MODIS)-based daily aerosol optical depth (AOD) values from March 6 through April 13, 2020. The average PM10 concentrations in the North and South Zones, in contrast to those observed at other global monitoring sites, increased by 13–38% and 4–7%, respectively, although they decreased by 26–31% in the Central Zone, between the pre-lockdown and lockdown periods. Furthermore, during the latter, the daily PM2.5 levels in the South Zone rose by up to 43%, and we found higher AOD values (≥ 0.4) over the Central and South Zones as well as significant AOD-contributing loads upwind and downwind of the coal production pits. Finally, the increases in humidity and temperature (≥ 3.5% and ≥ 0.3 K, respectively), decrease in planetary boundary layer height (≥ 0.11 km), wind field variability, and rural biomass burning events shaped the spatial-temporal behavior of the PM in this region, and changes in meteorology and external sources nearly offset the reduction in emissions from mining activities. These results establish a baseline for developing future regulations and mitigation plans.
add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
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For further information contact us at helpdesk@openaire.euAccess Routesgold 6 citations 6 popularity Top 10% influence Average impulse Top 10% Powered by BIP!more_vert add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.4209/aaqr.200664&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2014 ColombiaPublisher:Universidad Nacional de Colombia Authors: Enrique Muñoz; Pedro Tume; Gabriel Ortíz;Enrique Muñoz; Pedro Tume; Gabriel Ortíz;<p>As hydrological models become more prevalent in water resources planning and management, increasing levels of detail and precision are needed. Currently, reliable models that simulate the hydrological behavior of a basin are indispensable; however, it is also necessary to know the limits of the predictability and reliability of the model outputs. The present study evaluates the influence of uncertainty in the main input variable of the model, rainfall, on the output uncertainty of a hydrological model. Using concepts of identifiability and sensitivity, the uncertainty in the model structure and parameters was estimated. Then, the output uncertainty caused by uncertainties in i) the rainfall amounts and ii) the periods of the rainfall was determined. The main conclusion is that uncertainty in rainfall estimation during rainy periods produces greater output uncertainty. However, in non-rainy periods, the output uncertainty is not very sensitive to the uncertainty in rainfall. Finally, uncertainties in rainfall during the basin filling and emptying periods (Apr. – Jun. and Sep. – Nov., respectively) alter the uncertainty in subsequent periods. Therefore, uncertainties in these periods could result in limited ranges of model predictability.</p><p> </p><p><strong>Resumen</strong></p><p>Los modelos hidrológicos se han vuelto cada vez más necesarios en la planificación y gestión de recursos hídricos, donde un aumento en los niveles de detalle y precisión es necesario. Actualmente disponer de modelos para simular el comportamiento hidrológico de una cuenca resulta indispensable, sin embargo, también es necesario conocer los límites de predictibilidad y de confiabilidad de las salidas de un modelo. En este estudio se evalúan la influencia de la incertidumbre en la principal entrada de un modelo, la precipitación, sobre la incertidumbre de las salidas de un modelo hidrológico. Utilizando conceptos de identificabilidad y sensibilidad se estima la incertidumbre de los parámetros y estructura de un modelo. Luego, la incertidumbre en las salidas causadas por incertidumbre en i) los montos de precipitación, ii) los períodos de precipitación fue calculada. Como conclusiones se obtuvo que la incertidumbre en la estimación de la precipitación en períodos de lluvia produce mayor incertidumbre sobre las salidas. En períodos no lluviosos, la incertidumbre de las salidas es poco sensible a incertidumbre sobre las precipitaciones. Finalmente, incertidumbres en periodos de llenado y vaciado (Abril-Junio y Septiembre-Noviembre respectivamente) afectan la incertidumbre en las salidas en los períodos subsecuentes. Por lo tanto incertidumbres en aquellos períodos pueden resultar en rangos limitados de predictibilidad de un modelo.</p>
LAReferencia - Red F... arrow_drop_down Scientific Electronic Library Online - ColombiaArticle . 2014License: CC BYData sources: Scientific Electronic Library Online - Colombiaadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.15446/esrj.v18n1.38760&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesgold 8 citations 8 popularity Average influence Average impulse Average Powered by BIP!more_vert LAReferencia - Red F... arrow_drop_down Scientific Electronic Library Online - ColombiaArticle . 2014License: CC BYData sources: Scientific Electronic Library Online - Colombiaadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.15446/esrj.v18n1.38760&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2014 ColombiaPublisher:Universidad Nacional de Colombia Authors: Álvarez-Álvarez, Carlos Mauricio; Arias-Quintero, Carlos Andrés; Builes-Carvajal, Juan Sebastián; Ordoñez-Carmona, Oswaldo; +1 AuthorsÁlvarez-Álvarez, Carlos Mauricio; Arias-Quintero, Carlos Andrés; Builes-Carvajal, Juan Sebastián; Ordoñez-Carmona, Oswaldo; Zapata-Madrigal, Germán Darío;La investigación pretende identificar las variables que influyen en el aumento de riesgos por explosiones en minas de carbón subterráneas, especialmente en la acumulación del polvo de carbón en la parte superior de los sostenimientos, además de analizar cómo influyen estos en las pérdidas de carga del circuito de ventilación y la correcta evacuación del polvo de carbón. Dicho análisis se realizó mediante visitas guiadas de campo a la Mina Nechí (Municipio de Amagá, Antioquia) donde se observó que el polvo de carbón se acumula más significativamente en las puertas de madera que en los arcos de acero, se procedió a simular diferentes geometrías del sostenimiento y la cantidad de estos con el fin de determinar cuál geometría contribuye a disminuir las pérdidas de carga. Una vez analizados los diferentes escenarios, la geometría que optimiza el circuito de ventilación es la que se ha denominado geometría Circular 2, la cual presenta reducciones en las pérdidas de carga de hasta un 14.67% respecto a las otras geometrías analizadas bajo las mismas condiciones. Con esto se proponen alternativas más eficientes para optimizar el circuito de ventilación y garantizar condiciones de higiene y seguridad para los trabajadores al interior de las minas. The research aims to identify the variables which influence on the increase of risk for explosions in underground coal mines, especially in the accumulation of coal dust on top of the fortification, as well as analyze how these affect the load losses in the ventilation circuit and the proper evacuation of coal dust. This analysis was carried out by a guide field visits to Nechí Mine (Municipality Amagá, Antioquia) where it was observed that the coal dust accumulated significantly in the wooden doors that in the steel arches, we proceeded to simulate different geometries of fortification and the amount of these for the purpose to determine which is the geometry that contributes to reducing the load losses. After analyzing the different scenarios, the geometry that optimizes the ventilation circuit has been called geometry Circular 2, which shows reduction in load losses of up to 14.67% compared to other geometries analyzed under the same conditions. Whit this, are proposed alternatives more efficient to optimize the ventilation circuit and ensure health and safety conditions for workers inside the mine.
Boletín de Ciencias ... arrow_drop_down Scientific Electronic Library Online - ColombiaArticle . 2014License: CC BY NC NDData sources: Scientific Electronic Library Online - ColombiaBoletín de Ciencias de la TierraArticle . 2014 . Peer-reviewedLicense: CC BY NC NDData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.15446/rbct.n36.45519&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesgold 1 citations 1 popularity Average influence Average impulse Average Powered by BIP!more_vert Boletín de Ciencias ... arrow_drop_down Scientific Electronic Library Online - ColombiaArticle . 2014License: CC BY NC NDData sources: Scientific Electronic Library Online - ColombiaBoletín de Ciencias de la TierraArticle . 2014 . Peer-reviewedLicense: CC BY NC NDData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.15446/rbct.n36.45519&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2013Publisher:Instituto Colombiano del Petroleo Authors: Juan Pablo Gómez Montoya; Karen Paola Cacua Madero; Layrisser Iral Galeano; Andrés Amell Arrieta;Juan Pablo Gómez Montoya; Karen Paola Cacua Madero; Layrisser Iral Galeano; Andrés Amell Arrieta;doi: 10.29047/01225383.57
The effect of hydrogen enrichment was tested for a diesel-biogas dual fuel engine. The operation and performance characteristics, such as thermal efficiency, pollutant emissions and combustion parameters were determined. Experiments have been carried with a stationary compression ignition (CI) engine coupled with a generator in dual mode using a typical biogas composition of 60% vol. CH4 and 40% vol. CO2. For every load engine evaluated, the hydrogen concentration was varied from 5 to 20% H2 v/v. The results showed increases in peak pressure chamber up to 10.7 bar, and diesel substitution levels up to 80% under conditions of steady combustion without knocking. Also, thermal efficiency increases up to 16% and carbon monoxide emissions decreases up to 13% at full load, and 20% of hydrogen in engines operating in diesel-biogas dual mode.
add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.29047/01225383.57&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesgold 11 citations 11 popularity Top 10% influence Average impulse Average Powered by BIP!more_vert add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.29047/01225383.57&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2011 SpanishPublisher:Instituto Nacional de Salud Authors: Herrera, Astrid B; Rodríguez, Laura A; Niederbacher, Jürg;Herrera, Astrid B; Rodríguez, Laura A; Niederbacher, Jürg;Introducción. La contaminación en el hogar puede desempeñar un papel importante en el desarrollo y exacerbación del asma infantil, sobre todo entre niños genéticamente predispuestos. Objetivos. Evaluar la asociación entre la presencia de contaminantes biológicos intradomiciliarios y síntomas indicativos de asma, en preescolares de Bucaramanga, Colombia Materiales y métodos. Se hizo un estudio de corte transversal analítico, en menores de 7 años, en dos zonas de la ciudad con niveles diferentes de contaminación atmosférica por material particulado. Se evaluaron los síntomas respiratorios indicativos de asma y los contaminantes intradomiciliarios mediante cuestionarios previamente validados, las mediciones biológicas de ácaros y hongos por métodos de laboratorio estandarizados, y se usó el modelo log binomial para el análisis multivariado, que permitió evaluar asociaciones mediante la estimación de las razones de prevalencia. Resultados. Participaron 678 niños, con edad media de 42 meses. La prevalencia de síntomas respiratorios indicativos de asma fue 8,0 % (IC95%: 5,6-9,6), sin diferencias significativas entre las dos zonas de contaminación extradomiciliaria. El modelo binomial mostró que los síntomas de asma se asociaron con la presencia de: ácaros razón de prevalencia (RP)=1,78; IC95%: 1,0-3,0 y Acremonium sp. (RP=6,2; IC95%: 3,8-10,0), y antecedentes de neumonía (RP=4,0; IC95%: 2,5-6,4), de rinitis alérgica (RP=1,9; IC95%: 1,25-3,1), de prematuridad (RP=3,4; IC95%: 1,7-6,5), de padres con asma (RP=2,6; IC95%: 1,4-5,0) y de tenencia de mascotas (RP=0,4; IC95%: 0,2-0,9). Conclusiones. La exposición a contaminantes biológicos intramurales (ácaros y hongos), los antecedentes personales de prematuridad, neumonía o rinitis y el antecedente familiar de asma, incrementan la probabilidad de presentación de síntomas indicativos de asma bronquial en la población estudiada. Introduction. Indoorair pollution may play an important role in development and exacerbation of asthma in children. Objective. The association between the presence of indoor biological contaminants and respiratory symptoms related to asthma was assessed in preschool children. Materials and methods. This cross-sectional study was undertaken in Bucaramanga, Colombia, and included children <7 years of age living in two urban areas of with different levels of outdoor air pollution. The 678 children were an average of 3.5 years of age. Respiratory symptoms indicative of asthma and indoor air pollutants were assessed by previously validated questionnaires.. Biological samples potentially containing mites and fungi were collected by standardized laboratory methods. The log binomial regression model was used for multivariate analysis, using adjusted prevalence ratios (PR). Results. The prevalence of asthmatic respiratory symptoms was 8.0%; (95% C.I: 5.6-9.6), without significant differences between the two areas. Binomial model analysis showed that asthma symptoms were associated with mites (PR 1.78; 95% C.I. 1.0-3.0), Acremonium sp (PR 6.24; 95 C.I.: 3.8-10.0) and a history of child pneumonia (PR 4.0; 95% C.I. 2.5-6.4), allergic rhinitis (PR 1.9; 95% C.I.: 1.2-3.1), prematurity (PR 3.4; 95% C.I. 1.8-6.5), parents with asthma (PR 2.6; 95% C.I. 1.4-5.0) and pet ownership (PR 0.4; 95% C.I. 0.2-0.9). Conclusions. The indoor exposure to biological contaminants (dust mites and fungi), history of prematurity, pneumonia, rhinitis and family history of asthma increased the occurence of symptoms suggestive of asthma in young children.
Scientific Electroni... arrow_drop_down Scientific Electronic Library Online - ColombiaArticle . 2011License: CC BYData sources: Scientific Electronic Library Online - ColombiaAll Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=od_______618::c3266576565d72f76f93ede50db3d9e6&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eu0 citations 0 popularity Average influence Average impulse Average Powered by BIP!more_vert Scientific Electroni... arrow_drop_down Scientific Electronic Library Online - ColombiaArticle . 2011License: CC BYData sources: Scientific Electronic Library Online - ColombiaAll Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=od_______618::c3266576565d72f76f93ede50db3d9e6&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2020Publisher:Saint Petersburg State University S. V. Lebedev; Stanislav V. Dubrova; Petr V. Fedorov; Willington Siabato; Vitalij V. Kurilenko;This paper presents the results of simulating the conditions of absorption of natural radionuclides (uranium-238, thorium-232, potassium-40) in different environment media (water and quartz sand) to assess the effect of the shielding properties of environmental components on the intensity of external radiation exposure to the benthic biota. The source of radiation was the lower Tremadocian Dictyonema shale, which formed the bottom of the Baltic Paleobasin. Water and quartz sand, which was gradually deposited on the roof of the Dictyonema shale, were used in the simulation as media (materials) absorbing the primary radiation. The manuscript shows an experiment conducted in full-scale conditions considering a single exposure of a section of Ordovician rocks that includes highly radioactive Dictyonema shale. This is a small area, but the simulation results are also valid for larger areas as the Baltic Paleobasin. During the late Tremadocian — Floian, along with transgression, benthic biota began to emerge. The experiment shows quantitatively what dosage this biota could have experienced over tens and hundreds of thousands of years, until the Dictyonema shale was covered with a sufficiently thick layer of water-flooded sediments. Experimental data show that the presence of a 10 cm thick layer of water reaches absorption of 40 % of the integral flux of all gamma lines of natural radionuclides (NRN), and in a moist quartz sand layer of the same thickness the absorption value does not exceed 50 %. Thus, despite the screening effect of the environment, the benthic biota of Baltoscandia in the Early Ordovician could have been under significant radiation exposure for millennia. The main value of the experiment is that it was performed in situ, and exclusively natural media were used as modelling elements.
Vestnik of Saint Pet... arrow_drop_down Vestnik of Saint Petersburg University Earth SciencesArticle . 2020 . Peer-reviewedData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
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For further information contact us at helpdesk@openaire.euAccess Routesgold 0 citations 0 popularity Average influence Average impulse Average Powered by BIP!more_vert Vestnik of Saint Pet... arrow_drop_down Vestnik of Saint Petersburg University Earth SciencesArticle . 2020 . Peer-reviewedData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
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For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2014Publisher:Springer Science and Business Media LLC Funded by:FCT | LA 1, EC | VOLDIESFCT| LA 1 ,EC| VOLDIESSarah K. Brown; Helen Sian Crosweller; R. S. J. Sparks; Elizabeth Cottrell; Natalia I. Deligne; Natalie Ortiz Guerrero; Laura Hobbs; Koji Kiyosugi; Susan C. Loughlin; Lee Siebert; Shinji Takarada;The Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database contains data on 1,883 Quaternary eruption records of magnitude (M) 4 and above and is publically accessible online via the British Geological Survey. Spatial and temporal analysis of the data indicates that the record is incomplete and is thus biased. The recorded distribution of volcanoes is variable on a global scale, with three-quarters of all volcanoes with M≥4 Quaternary activity located in the northern hemisphere and a quarter within Japan alone. The distribution of recorded eruptions does not strictly follow the spatial distribution of volcanoes and has distinct intra-regional variability, with about 40% of all recorded eruptions having occurred in Japan, reflecting in part the country’s efforts devoted to comprehensive volcanic studies. The number of eruptions in LaMEVE decreases with increasing age, exemplified by the recording of 50% of all known Quaternary eruptions during the last 20,000 years. Historical dating is prevalent from 1450 AD to the present day, substantially improving record completeness. The completeness of the record also improves as magnitude increases. This is demonstrated by the calculation of the median time, T50, for eruptions within given magnitude intervals, where 50% of eruptions are older than T50: T50 ranges from 5,070 years for M4-4.9 eruptions to 935,000 years for M≥8 eruptions. T50 follows a power law fit, suggesting a quantifiable relationship between eruption size and preservation potential of eruptive products. Several geographic regions have T50 ages of <250 years for the smallest (~M4) eruptions reflecting substantial levels of under-recording. There is evidence for latitudinal variation in eruptive activity, possibly due to the effects of glaciation. A peak in recorded activity is identified at 11 to 9 ka in high-latitude glaciated regions. This is absent in non-glaciated regions, supporting the hypothesis of increased volcanism due to ice unloading around this time. Record completeness and consequent interpretation of record limitations are important in understanding volcanism on global to local scales and must be considered during rigorous volcanic hazard and risk assessments. The study also indicates that there need to be improvements in the quality of data, including assessment of uncertainties in volume estimates.
Journal of Applied V... arrow_drop_down add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
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For further information contact us at helpdesk@openaire.euAccess Routesgold 91 citations 91 popularity Top 1% influence Top 10% impulse Top 10% Powered by BIP!visibility 3visibility views 3 download downloads 159 Powered bymore_vert Journal of Applied V... arrow_drop_down add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
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For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2019Publisher:Universidad EAFIT Authors: Ludger O. Suarez-Burgoa; Alvaro J. Castro-Caicedo;Ludger O. Suarez-Burgoa; Alvaro J. Castro-Caicedo;El presente artículo expone el procedimiento para lograr el modelo geométrico tridimensional de un macizo rocoso a partir de un par de tomas fotográficas hechas con una cámara corriente, uso de software libre/abierto como Octave y otras librerías libres, construcción de equipos y herramientas sencillos y la apropiación de conocimientos importantes en visión artificial. Se describe tomando como ejemplo el modelo tridimensional de un corte de voladura del macizo rocoso de la Cantera Santa Rita, localizada al sudoeste de la ciudad de Medellín (Colombia). Finalmente, se muestra mediante una validación, a partir de medidas de campo in situ, que el procedimiento descrito aquí es promisorio para que pueda instaurarse como una herramienta para la caracterización geométrica de discontinuidades de los macizos rocosos.
add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
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For further information contact us at helpdesk@openaire.euAccess RoutesGreen gold 0 citations 0 popularity Average influence Average impulse Average Powered by BIP!more_vert add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.17230/ingciencia.15.30.2&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Preprint , Article 2023Publisher:IOP Publishing Authors: Gabriel Narvaez; Michael Bressan; Andres Pantoja; Luis Felipe Giraldo;Gabriel Narvaez; Michael Bressan; Andres Pantoja; Luis Felipe Giraldo;Abstract This paper presents the first study of the long-term impact of climate change on photovoltaic potential in South America. This region has great potential for implementing renewable energy, mainly solar energy solutions, due to its high solar irradiance levels. Based on the Coordinated Regional Downscaling Experiment (CORDEX) for the South American region, we estimate how climate change could affect photovoltaic power potential by the end of the century. The evidence suggests that photovoltaic potential could have a maximum decrease of around 15%, and a maximum increase of approximately 7%, primarily due to changes in solar irradiance of different zones. Furthermore, it is observed that regions with increased temperature also show increased solar irradiance levels, which could, to some extent, compensate for the losses caused by the rise in temperature. Therefore, photovoltaic production in most of the territory will not be negatively affected.
arXiv.org e-Print Ar... arrow_drop_down Environmental Research CommunicationsArticle . 2023 . Peer-reviewedLicense: CC BYData sources: Crossrefhttps://doi.org/10.48550/arxiv...Article . 2023License: arXiv Non-Exclusive DistributionData sources: Dataciteadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1088/2515-7620/acf02e&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess RoutesGreen gold 0 citations 0 popularity Average influence Average impulse Average Powered by BIP!more_vert arXiv.org e-Print Ar... arrow_drop_down Environmental Research CommunicationsArticle . 2023 . Peer-reviewedLicense: CC BYData sources: Crossrefhttps://doi.org/10.48550/arxiv...Article . 2023License: arXiv Non-Exclusive DistributionData sources: Dataciteadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1088/2515-7620/acf02e&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2017Publisher:IOP Publishing Authors: J. A. García Zúñiga; A. Sarmiento Santos; E Y Soto Gómez;J. A. García Zúñiga; A. Sarmiento Santos; E Y Soto Gómez;1020 steel is a material very used for surface treatment in the abnormal glow discharge. Because the composition of the gaseous atmosphere has an important influence on the results of plasma treatment, in this work the oxidation process of 1020 steel is verified on the abnormal glow discharge under different concentrations of air (20% to 100%) at temperatures of 600°C and 900°C. For each atmosphere used mass variation is measured during the process of surface oxidation, the structure and microstructure of the oxide film formed is observed and also its mechanical properties through its microhardness.
Journal of Physics :... arrow_drop_down Journal of Physics : Conference SeriesArticle . 2017 . Peer-reviewedLicense: CC BYData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1088/1742-6596/786/1/012036&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesgold 0 citations 0 popularity Average influence Average impulse Average Powered by BIP!more_vert Journal of Physics :... arrow_drop_down Journal of Physics : Conference SeriesArticle . 2017 . Peer-reviewedLicense: CC BYData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1088/1742-6596/786/1/012036&type=result"></script>'); --> </script>
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