Diseño de un Equipo de Recuperación de Líquidos de Gas Natural Empleando CFD

En el proceso convencional para el tratamiento de gas natural se emplean tres etapas: endulzamiento, deshidratación y control de punto de rocío (HDP: Hydrocarbon Dew Point). Este proceso permite llevar el gas natural a especificaciones según las entidades de regulación locales [11]. Desarrollos recientes muestran que es posible implementar un solo equipo capaz de realizar la deshidratación y el control de Dew Point en una misma unidad de proceso, disminuyendo así la cantidad de equipos requeridos y el consumo energético asociado a la operación. La compañía holandesa Twister Bv [20] ha desarrollado equipos supersónicos compactos de tratamiento de gas natural pero se desconoce toda la información relacionada con la geometría de sus internos. Con el fin de diseñar uno de estos equipos y mejorar su rendimiento, en este trabajo y en asocio con la compañía colombiana HNA ingeniería Ltda, se empleó la Dinámica Computacional de Fluidos (CFD) para diseñar un equipo de Recuperación de Líquidos de Gas Natural (LGN) y en especial determinar la geometría de los internos. Se empleó la información disponible para definir la geometría del equipo, a pesar de que esta es muy limitada. Se evaluaron varias geometrías posibles para este equipo considerando todos los detalles de sus internos, los resultados fueron comparados con la información experimental disponible correspondiente al perfil de presión del equipo [20]. La modelación CFD se desarrolló en estado transitorio, incluyó el comportamiento multifásico de los fluidos, la turbulencia, y la termodinámica. Para el desarrollo de estas simulaciones se utilizó un computador con 128 Gb de RAM y 2 procesadores Intel Xeon 16 core 2.0 GHz. Uno de los fenómenos más complejos de modelar en CFD es la turbulencia. La literatura recomienda emplear el modelo de turbulencia RSM para simular la turbulencia en este tipo de flujos. Pero este modelo demanda grandes recursos computacionales. Una alternativa es emplear el modelo k-ԑ RNG modificado, sin embargo este modelo no ha sido probado. Los resultados de este trabajo indican que el modelo k-ԑ RNG modificado produce prácticamente los mismos resultados que el modelo RSM pero con una reducción de hasta un 25% en el tiempo de computo. Adicionalmente, se determinó el valor adecuado del Factor de giro (Swirl Factor) con el cual se obtienen resultados más precisos con el modelo k-ԑ RNG modificado. Se plantearon geometrías adicionales con el fin de mejorar la eficiencia del equipo en términos de la separación de LGN. El diseño final es un equipo para la recuperación de LGN con una eficiencia de remoción de líquidos de gas natural de 75%, la cual es un 11% más alta que la reportada por Twister BV [17] Una de las mayores preocupaciones cuando se trabaja con este tipo de equipos en los cuales las velocidades de los fluidos son muy altas, es la pérdida de material debida a la erosión. Por tanto, en este trabajo también se evaluaron las regiones de mayor daño al equipo por erosión, se estimó la pérdida de material media debida a este fenómeno natural de la operación. Finalmente, se concluye que es posible diseñar y mejorar el desempeño de este tipo de equipos empleando la tecnología CFD. Esto abre las puertas a procesos más eficientes, y por lo tanto ambientalmente más amigables, a la vez que representa oportunidades de desarrollo como temas de investigaciones futuras en áreas como procesos, mecánica, materiales y recubrimientos y control y automatización de procesos. La implementación de este tipo de procesos permitirá obtener ventajas competitivas frente a otras tecnologías de tratamiento de gas natural.Abstract. The conventional natural gas treatment process has three stages: sweetening, dehydration and dew point control. This process allows the natural gas to meet specifications according with the local regulation entities [11]. Recent developments show that is possible to design an equipment able to dehydrate and adjust the natural gas dew point in one single process unit, reducing the equipment and energy consumption. The company Twister BV [20] has developed supersonic compact equipment designs but the geometrical details are unknown. Aiming to design one of these devices and improve their performance in this project and with the collaboration of the colombian company HNA Engineering, CFD was implemented for the NGL recovery process modeling and in special aiming to determine the internals geometry of the equipment. Available information was used to define the possible geometries. Possible equipment geometries were evaluated considering all the internal details, the results were compared with the experimental information available about the hydraulic profile in the equipment [20]. The CFD modeling was developed in transient state and the multiphase behavior of the fluids, the turbulence and thermodynamics were included. For the development of these simulations high computation capacity was used: 128 Gb RAM and 2 Intel Xeon 16 core 2.0 GHz processors. One of the most complex phenomena to model using CFD is the turbulence. The literature [17] recommends the use of RSM to simulate the turbulence in this kind of flows. But this model requires a big computational capacity. One alternative is to implement the turbulence model k-ԑ RNG modified for swirl Flow, however this model have not been probed. The results obtained in this work indicate that the model model k-ԑ RNG modified allows obtaining the almost the same results than RSM but with a computational time reduction of about 25%. Furthermore, the suitable value of swirl factor was determined to obtain more accurate results with the model k-ԑ RNG modified for swirl flow. Further geometries were developed aiming to improve the performance of the equipment relating the separation efficiency of NGL, an efficiency of 75% was obtained, 11% higher than the value reported by Twister Bv [17]. One of the main concerns about the operation of this kind of high velocity flow equipment is the surface damage due to the erosion. For that reason in this document is presented an evaluation of the regions with more possibilities to be damaged considering the erosion effect, and was also evaluated the mean losses of material due to this phenomena of the operation of the equipment simulation. Finally is concluded that is possible design and improve the performance of this kind of process equipment using CFD technology. This opens the doors to more efficient and environmentally friendly processes, at the same time it represents opportunities for future researches to be developed in fields as processes, mechanics, materials and coatings, automation and control of processes. The implementation of this kind of processes allows getting competitive advantages in comparison with other technologies for gas treatment.Maestrí

A global observational analysis to understand changes in air quality during exceptionally low anthropogenic emission conditions

This global study, which has been coordinated by the World Meteorological Organization Global Atmospheric Watch (WMO/GAW) programme, aims to understand the behaviour of key air pollutant species during the COVID-19 pandemic period of exceptionally low emissions across the globe. We investigated the effects of the differences in both emissions and regional and local meteorology in 2020 compared with the period 2015-2019. By adopting a globally consistent approach, this comprehensive observational analysis focuses on changes in air quality in and around cities across the globe for the following air pollutants PM2.5, PM10, PMC (coarse fraction of PM), NO2, SO2, NOx, CO, O-3 and the total gaseous oxidant (O-X = NO2 + O-3) during the pre-lockdown, partial lockdown, full lockdown and two relaxation periods spanning from January to September 2020. The analysis is based on in situ ground-based air quality observations at over 540 traffic, background and rural stations, from 63 cities and covering 25 countries over seven geographical regions of the world. Anomalies in the air pollutant concentrations (increases or decreases during 2020 periods compared to equivalent 2015-2019 periods) were calculated and the possible effects of meteorological conditions were analysed by computing anomalies from ERA5 reanalyses and local observations for these periods. We observed a positive correlation between the reductions in NO2 and NOx concentrations and peoples' mobility for most cities. A correlation between PMC and mobility changes was also seen for some Asian and South American cities. A clear signal was not observed for other pollutants, suggesting that sources besides vehicular emissions also substantially contributed to the change in air quality. As a global and regional overview of the changes in ambient concentrations of key air quality species, we observed decreases of up to about 70% in mean NO2 and between 30% and 40% in mean PM2.5 concentrations over 2020 full lockdown compared to the same period in 2015-2019. However, PM2.5 exhibited complex signals, even within the same region, with increases in some Spanish cities, attributed mainly to the long-range transport of African dust and/or biomass burning (corroborated with the analysis of NO2/CO ratio). Some Chinese cities showed similar increases in PM2.5 during the lockdown periods, but in this case, it was likely due to secondary PM formation. Changes in O-3 concentrations were highly heterogeneous, with no overall change or small increases (as in the case of Europe), and positive anomalies of 25% and 30% in East Asia and South America, respectively, with Colombia showing the largest positive anomaly of similar to 70%. The SO2 anomalies were negative for 2020 compared to 2015-2019 (between similar to 25 to 60%) for all regions. For CO, negative anomalies were observed for all regions with the largest decrease for South America of up to similar to 40%. The NO2/CO ratio indicated that specific sites (such as those in Spanish cities) were affected by biomass burning plumes, which outweighed the NO2 decrease due to the general reduction in mobility (ratio of similar to 60%). Analysis of the total oxidant (OX = NO2 + O-3) showed that primary NO2 emissions at urban locations were greater than the O-3 production, whereas at background sites, O-X was mostly driven by the regional contributions rather than local NO2 and O-3 concentrations. The present study clearly highlights the importance of meteorology and episodic contributions (e.g., from dust, domestic, agricultural biomass burning and crop fertilizing) when analysing air quality in and around cities even during large emissions reductions. There is still the need to better understand how the chemical responses of secondary pollutants to emission change under complex meteorological conditions, along with climate change and socio-economic drivers may affect future air quality. The implications for regional and global policies are also significant, as our study clearly indicates that PM2.5 concentrations would not likely meet the World Health Organization guidelines in many parts of the world, despite the drastic reductions in mobility. Consequently, revisions of air quality regulation (e.g., the Gothenburg Protocol) with more ambitious targets that are specific to the different regions of the world may well be required.Peer reviewe

Consenso mexicano para el diagnóstico y tratamiento de la dermatitis atópica en adolescentes y adultos

Abstract Background: The diagnostic approaches and therapeutic strategies of atopic dermatitis (AD) are generally inconsistent among physicians and health institutions. Objective: To develop a consensus statement among experts to reduce the variations in practice regarding the diagnosis and treatment of patients ≥ 12 years with AD to improve their care. Methods: Systematic literature search in PubMed and GREAT. With methodological support and using the Delphi method, a formal consensus was developed among 16 experts in Dermatology and Allergology, based on the current evidence and its applicability in the Mexican context. Apart from intense electronic communication, several issues of disagreement were discussed in two face-to-face meetings. Results: The clinical experts reached consensus on 46 statements related to the definition, classification, diagnostic strategies and treatment of AD. For the diagnosis we suggest the Williams criteria and for severity scoring the SCORAD (by the doctor) and POEM (by the patient). In addition to general care and treatment education (workshops), we suggest four steps for treatment, depending on severity: 1. Topical treatment with anti-inflammatory agents (and systemic: antihistamines/antileukotrienes —low level evidence—) 2. Phototherapy, 3. Cyclosporin A and 4. Dupilumab, with the possibility of managing this biological earlier on if a fast effect is needed. In extrinsic AD we suggest evaluating the addition of allergen immunotherapy or an elimination diet, if there is an IgE-mediated respiratory or food allergy, respectively. Conclusion: The panel of experts reached consensus on relevant aspects of AD with a focus on the transcultural adaptation of recent evidence. Keywords: Atopic dermatitis; Atopic dermatitis treatment; Consensus; Cyclosporin A; Biological treatment; Dupilumab; Omalizumab. Resumen Antecedentes: Los abordajes diagnósticos y las estrategias terapéuticas de la dermatitis atópica generalmente son inconsistentes entre los médicos y entre las instituciones de salud. Objetivo: Consensar las opiniones de expertos para reducir las variaciones en la práctica respecto al diagnóstico y tratamiento de pacientes ≥ 12 años con dermatitis atópica para mejorar su cuidado. Métodos: Búsqueda sistemática de la literatura en PubMed y GREAT. Con apoyo metodológico y utilizando el método Delphi se desarrolló un consenso formal entre 16 expertos en dermatología y alergología, basándose en la evidencia actual y su aplicabilidad en el contexto mexicano. A parte de una comunicación electrónica intensa, se discutieron los puntos en desacuerdo en dos reuniones presenciales. Resultados: Los expertos clínicos alcanzaron consenso en 46 declaraciones relacionadas con la definición, clasificación, estrategias de diagnóstico y tratamiento de la dermatitis atópica. Para el diagnóstico sugerimos se usan los criterios de Williams y el SCORAD (por parte del médico) y POEM (por parte del paciente) para definir la gravedad. Aunado a cuidados generales y educación terapéutica, sugerimos cuatro pasos para tratamiento, según gravedad: 1. Manejo tópico con antiinflamatorio (y sistémico: antihistamínico/ antileucotrieno —evidencia reducida—) 2. Fototerapia, 3. Ciclosporina A y 4. Dupilumab, con la posibilidad de manejarlo antes si se necesita efecto rápido. En la dermatitis atópica extrínseca sugerimos agregar inmunoterapia con alérgenos o una dieta de eliminación si existe una alergia IgE-mediada, inhalatoria o alimentaria, respectivamente. Conclusión: El panel de expertos realizó consenso en aspectos relevantes de la dermatitis atópica con enfoque en la adaptación transcultural de evidencia reciente. Palabras clave: Dermatitis atópica; Ciclosporina A; Tratamiento biológico; Dupilumab; Omalizumab; Posición de consenso

A global observational analysis to understand changes in air quality during exceptionally low anthropogenic emission

This global study, which has been coordinated by the World Meteorological Organization Global Atmospheric Watch (WMO/GAW) programme, aims to understand the behaviour of key air pollutant species during the COVID-19 pandemic period of exceptionally low emissions across the globe. We investigated the effects of the differences in both emissions and regional and local meteorology in 2020 compared with the period 2015–2019. By adopting a globally consistent approach, this comprehensive observational analysis focuses on changes in air quality in and around cities across the globe for the following air pollutants PM2.5, PM10, PMC (coarse fraction of PM), NO2, SO2, NOx, CO, O3 and the total gaseous oxidant (OX = NO2 + O3) during the pre-lockdown, partial lockdown, full lockdown and two relaxation periods spanning from January to September 2020. The analysis is based on in situ ground-based air quality observations at over 540 traffic, background and rural stations, from 63 cities and covering 25 countries over seven geographical regions of the world. Anomalies in the air pollutant concentrations (increases or decreases during 2020 periods compared to equivalent 2015–2019 periods) were calculated and the possible effects of meteorological conditions were analysed by computing anomalies from ERA5 reanalyses and local observations for these periods. We observed a positive correlation between the reductions in NO2 and NOx concentrations and peoples’ mobility for most cities. A correlation between PMC and mobility changes was also seen for some Asian and South American cities. A clear signal was not observed for other pollutants, suggesting that sources besides vehicular emissions also substantially contributed to the change in air quality. As a global and regional overview of the changes in ambient concentrations of key air quality species, we observed decreases of up to about 70% in mean NO2 and between 30% and 40% in mean PM2.5 concentrations over 2020 full lockdown compared to the same period in 2015–2019. However, PM2.5 exhibited complex signals, even within the same region, with increases in some Spanish cities, attributed mainly to the long-range transport of African dust and/or biomass burning (corroborated with the analysis of NO2/CO ratio). Some Chinese cities showed similar increases in PM2.5 during the lockdown periods, but in this case, it was likely due to secondary PM formation. Changes in O3 concentrations were highly heterogeneous, with no overall change or small increases (as in the case of Europe), and positive anomalies of 25% and 30% in East Asia and South America, respectively, with Colombia showing the largest positive anomaly of ~70%. The SO2 anomalies were negative for 2020 compared to 2015–2019 (between ~25 to 60%) for all regions. For CO, negative anomalies were observed for all regions with the largest decrease for South America of up to ~40%. The NO2/CO ratio indicated that specific sites (such as those in Spanish cities) were affected by biomass burning plumes, which outweighed the NO2 decrease due to the general reduction in mobility (ratio of ~60%). Analysis of the total oxidant (OX = NO2 + O3) showed that primary NO2 emissions at urban locations were greater than the O3 production, whereas at background sites, OX was mostly driven by the regional contributions rather than local NO2 and O3 concentrations. The present study clearly highlights the importance of meteorology and episodic contributions (e.g., from dust, domestic, agricultural biomass burning and crop fertilizing) when analysing air quality in and around cities even during large emissions reductions. There is still the need to better understand how the chemical responses of secondary pollutants to emission change under complex meteorological conditions, along with climate change and socio-economic drivers may affect future air quality. The implications for regional and global policies are also significant, as our study clearly indicates that PM2.5 concentrations would not likely meet the World Health Organization guidelines in many parts of the world, despite the drastic reductions in mobility. Consequently, revisions of air quality regulation (e.g., the Gothenburg Protocol) with more ambitious targets that are specific to the different regions of the world may well be required.Peer reviewedFinal Published versio

A global observational analysis to understand changes in air quality during exceptionally low anthropogenic emission conditions

This global study, which has been coordinated by the World Meteorological Organization Global Atmospheric Watch (WMO/GAW) programme, aims to understand the behaviour of key air pollutant species during the COVID-19 pandemic period of exceptionally low emissions across the globe. We investigated the effects of the differences in both emissions and regional and local meteorology in 2020 compared with the period 2015–2019. By adopting a globally consistent approach, this comprehensive observational analysis focuses on changes in air quality in and around cities across the globe for the following air pollutants PM2.5, PM10, PMC (coarse fraction of PM), NO2, SO2, NOx, CO, O3 and the total gaseous oxidant (OX = NO2 + O3) during the pre-lockdown, partial lockdown, full lockdown and two relaxation periods spanning from January to September 2020. The analysis is based on in situ ground-based air quality observations at over 540 traffic, background and rural stations, from 63 cities and covering 25 countries over seven geographical regions of the world. Anomalies in the air pollutant concentrations (increases or decreases during 2020 periods compared to equivalent 2015–2019 periods) were calculated and the possible effects of meteorological conditions were analysed by computing anomalies from ERA5 reanalyses and local observations for these periods. We observed a positive correlation between the reductions in NO2 and NOx concentrations and peoples’ mobility for most cities. A correlation between PMC and mobility changes was also seen for some Asian and South American cities. A clear signal was not observed for other pollutants, suggesting that sources besides vehicular emissions also substantially contributed to the change in air quality. As a global and regional overview of the changes in ambient concentrations of key air quality species, we observed decreases of up to about 70% in mean NO2 and between 30% and 40% in mean PM2.5 concentrations over 2020 full lockdown compared to the same period in 2015–2019. However, PM2.5 exhibited complex signals, even within the same region, with increases in some Spanish cities, attributed mainly to the long-range transport of African dust and/or biomass burning (corroborated with the analysis of NO2/CO ratio). Some Chinese cities showed similar increases in PM2.5 during the lockdown periods, but in this case, it was likely due to secondary PM formation. Changes in O3 concentrations were highly heterogeneous, with no overall change or small increases (as in the case of Europe), and positive anomalies of 25% and 30% in East Asia and South America, respectively, with Colombia showing the largest positive anomaly of ~70%. The SO2 anomalies were negative for 2020 compared to 2015–2019 (between ~25 to 60%) for all regions. For CO, negative anomalies were observed for all regions with the largest decrease for South America of up to ~40%. The NO2/CO ratio indicated that specific sites (such as those in Spanish cities) were affected by biomass burning plumes, which outweighed the NO2 decrease due to the general reduction in mobility (ratio of ~60%). Analysis of the total oxidant (OX = NO2 + O3) showed that primary NO2 emissions at urban locations were greater than the O3 production, whereas at background sites, OX was mostly driven by the regional contributions rather than local NO2 and O3 concentrations. The present study clearly highlights the importance of meteorology and episodic contributions (e.g., from dust, domestic, agricultural biomass burning and crop fertilizing) when analysing air quality in and around cities even during large emissions reductions. There is still the need to better understand how the chemical responses of secondary pollutants to emission change under complex meteorological conditions, along with climate change and socio-economic drivers may affect future air quality. The implications for regional and global policies are also significant, as our study clearly indicates that PM2.5 concentrations would not likely meet the World Health Organization guidelines in many parts of the world, despite the drastic reductions in mobility. Consequently, revisions of air quality regulation (e.g., the Gothenburg Protocol) with more ambitious targets that are specific to the different regions of the world may well be required.World Meteorological Organization Global Atmospheric Watch programme is gratefully acknowledged for initiating and coordinating this study and for supporting this publication. We acknowledge the following projects for supporting the analysis contained in this article: Air Pollution and Human Health for an Indian Megacity project PROMOTE funded by UK NERC and the Indian MOES, Grant reference number NE/P016391/1; Regarding project funding from the European Commission, the sole responsibility of this publication lies with the authors. The European Commission is not responsible for any use that may be made of the information contained therein. This project has received funding from the European Commission’s Horizon 2020 research and innovation program under grant agreement No 874990 (EMERGE project). European Regional Development Fund (project MOBTT42) under the Mobilitas Pluss programme; Estonian Research Council (project PRG714); Estonian Research Infrastructures Roadmap project Estonian Environmental Observatory (KKOBS, project 2014-2020.4.01.20-0281). European network for observing our changing planet project (ERAPLANET, grant agreement no. 689443) under the European Union’s Horizon 2020 research and innovation program, Estonian Ministry of Sciences projects (grant nos. P180021, P180274), and the Estonian Research Infrastructures Roadmap project Estonian Environmental Observatory (3.2.0304.11-0395). Eastern Mediterranean and Middle East—Climate and Atmosphere Research (EMME-CARE) project, which has received funding from the European Union’s Horizon 2020 Research and Innovation Programme (grant agreement no. 856612) and the Government of Cyprus. INAR acknowledges support by the Russian government (grant number 14.W03.31.0002), the Ministry of Science and Higher Education of the Russian Federation (agreement 14.W0331.0006), and the Russian Ministry of Education and Science (14.W03.31.0008). We are grateful to to the following agencies for providing access to data used in our analysis: A.M. Obukhov Institute of Atmospheric Physics Russian Academy of Sciences; Agenzia Regionale per la Protezione dell’Ambiente della Campania (ARPAC); Air Quality and Climate Change, Parks and Environment (MetroVancouver, Government of British Columbia); Air Quality Monitoring & Reporting, Nova Scotia Environment (Government of Nova Scotia); Air Quality Monitoring Network (SIMAT) and Emission Inventory, Mexico City Environment Secretariat (SEDEMA); Airparif (owner & provider of the Paris air pollution data); ARPA Lazio, Italy; ARPA Lombardia, Italy; Association Agr´e´ee de Surveillance de la Qualit´e de l’Air en ˆIle-de- France AIRPARIF / Atmo-France; Bavarian Environment Agency, Germany; Berlin Senatsverwaltung für Umwelt, Verkehr und Klimaschutz, Germany; California Air Resources Board; Central Pollution Control Board (CPCB), India; CETESB: Companhia Ambiental do Estado de S˜ao Paulo, Brazil. China National Environmental Monitoring Centre; Chandigarh Pollution Control Committee (CPCC), India. DCMR Rijnmond Environmental Service, the Netherlands. Department of Labour Inspection, Cyprus; Department of Natural Resources Management and Environmental Protection of Moscow. Environment and Climate Change Canada; Environmental Monitoring and Science Division Alberta Environment and Parks (Government of Alberta); Environmental Protection Authority Victoria (Melbourne, Victoria, Australia); Estonian Environmental Research Centre (EERC); Estonian University of Life Sciences, SMEAR Estonia; European Regional Development Fund (project MOBTT42) under the Mobilitas Pluss programme; Finnish Meteorological Institute; Helsinki Region Environmental Services Authority; Haryana Pollution Control Board (HSPCB), IndiaLondon Air Quality Network (LAQN) and the Automatic Urban and Rural Network (AURN) supported by the Department of Environment, Food and Rural Affairs, UK Government; Madrid Municipality; Met Office Integrated Data Archive System (MIDAS); Meteorological Service of Canada; Minist`ere de l’Environnement et de la Lutte contre les changements climatiques (Gouvernement du Qu´ebec); Ministry of Environment and Energy, Greece; Ministry of the Environment (Chile) and National Weather Service (DMC); Moscow State Budgetary Environmental Institution MOSECOMONITORING. Municipal Department of the Environment SMAC, Brazil; Municipality of Madrid public open data service; National institute of environmental research, Korea; National Meteorology and Hydrology Service (SENAMHI), Peru; New York State Department of Environmental Conservation; NSW Department of Planning, Industry and Environment; Ontario Ministry of the Environment, Conservation and Parks, Canada; Public Health Service of Amsterdam (GGD), the Netherlands. Punjab Pollution Control Board (PPCB), India. R´eseau de surveillance de la qualit´e de l’air (RSQA) (Montr´eal); Rosgydromet. Mosecomonitoring, Institute of Atmospheric Physics, Russia; Russian Foundation for Basic Research (project 20–05–00254) SAFAR-IITM-MoES, India; S˜ao Paulo State Environmental Protection Agency, CETESB; Secretaria de Ambiente, DMQ, Ecuador; Secretaría Distrital de Ambiente, Bogot´a, Colombia. Secretaria Municipal de Meio Ambiente Rio de Janeiro; Mexico City Atmospheric Monitoring System (SIMAT); Mexico City Secretariat of Environment, Secretaría del Medio Ambiente (SEDEMA); SLB-analys, Sweden; SMEAR Estonia station and Estonian University of Life Sciences (EULS); SMEAR stations data and Finnish Center of Excellence; South African Weather Service and Department of Environment, Forestry and Fisheries through SAAQIS; Spanish Ministry for the Ecological Transition and the Demographic Challenge (MITECO); University of Helsinki, Finland; University of Tartu, Tahkuse air monitoring station; Weather Station of the Institute of Astronomy, Geophysics and Atmospheric Science of the University of S˜ao Paulo; West Bengal Pollution Control Board (WBPCB).http://www.elsevier.com/locate/envintam2023Geography, Geoinformatics and Meteorolog

Gestión del conocimiento. Perspectiva multidisciplinaria. Volumen 9

El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, volumen 9, de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro es una publicación internacional, seriada, continua, arbitrada de acceso abierto a todas las áreas del conocimiento, que cuenta con el esfuerzo de investigadores de varios países del mundo, orientada a contribuir con procesos de gestión del conocimiento científico, tecnológico y humanístico que consoliden la transformación del conocimiento en diferentes escenarios, tanto organizacionales como universitarios, para el desarrollo de habilidades cognitivas del quehacer diario. La gestión del conocimiento es un camino para consolidar una plataforma en las empresas públicas o privadas, entidades educativas, organizaciones no gubernamentales, ya sea generando políticas para todas las jerarquías o un modelo de gestión para la administración, donde es fundamental articular el conocimiento, los trabajadores, directivos, el espacio de trabajo, hacia la creación de ambientes propicios para el desarrollo integral de las instituciones

CFD Modeling of Particulate Matter PM2.5 inside BRT public transport buses

High pollution levels have been detected by local air quality monitoring network in Bogotá. Vehicle emissions are an important and direct source of pollution, heavy traffic roads are places where particulate matter pollution presents high concentrations and population exposure. Assessment of the exposure levels of passengers inside the massive transport system is an important case of study in megacities such as Bogotá due to the long residence time of the passengers. Bus Rapid Transit BRT has been implemented at the beginnings of the years 2000’s in the city of Bogotá. This is one of the most representative cases worldwide and it has spread the model around cities like Cali, Bucaramanga and Cartagena. The aim of this study is to perform a CFD modeling evaluation to provide detailed information regarding the passenger exposure in massive public transport system. CFD modeling of particulate matter dispersion inside bus can help identifying “hot-spots” of pollution. The developed modeling considers the conditions of the bus when there is low passenger traffic, windows open and cruise speed of 60 km/h. Data-set obtained for particulate matter was measured in real time and used for model validation, pre-processing and post-processing stages. A BRT transport system is characterized by the existence of an exclusive lane for the articulated buses, which operate normally using diesel fuel. This public transport model results attractive for third world countries thanks to its low costs in respect of subway systems. Pollution levels in the cities where it is implemented the BRT model usually present unfavorable Air Quality Indexes, which implies that the users of the system are exposed to contaminants presents in the air, like particulate matter PM2.5, associated directly with diesel burn and with cardiovascular illnesses and lung cancer. With the aim of knowing the PM2.5 levels inside of public transport buses, in a spatially and temporally detailed form, a CFD model was implemented and validated with data obtained from a measuring campaign. This allows analyzing the pollution levels at which are exposed every day the passengers of the public transport system BRT in the city of Bogotá

Evaluación espacial y temporal de PM10 y PM2.5 con datos de CAMS, MODIS-AOD y mediciones de superficie en de calidad del aire de Colombia

La estimación de los niveles de material particulado PM10 y PM2.5 es parte importante de la evaluación de la calidad del aire.  En zonas en las que no se tiene monitoreo de calidad del aire en superficie, el uso de datos satelitales y reanálisis es una alternativa viable y de bajo costo aplicable en cualquier lugar del mundo. El paquete de datos “Copernicus Atmosphere Monitoring Service” (CAMS) cubre todo el globo con una resolución espacial de 0.1° (11 km), una resolución temporal de 1 hora y reporta información de la composición atmosférica y los procesos que tienen lugar en la misma, en tiempo real y predicciones de 4 días en el futuro para muchos contaminantes. Estas características hacen de CAMS un paquete de datos con posibilidad de ser aplicado para analizar la calidad del aire en países en vía de desarrollo. Por otra parte, la profundidad óptica de aerosol (AOD) de 550 nm tomada de los satélites “Moderate Resolution Imaging Spectroraiometer” (MODIS) de la NASA, tiene una resolución espacial de 1° (111 km), resolución temporal de 1 hora, sujeta a disponibilidad de datos por trayectorias polares de los satélites Terra-Aqua, y nubosidad. AOD de MODIS es una variable que ha sido utilizada en estudios previos para predecir niveles de PM10 en Colombia. El objetivo de este estudio es evaluar la calidad del aire en Colombia para PM2.5 y PM10 utilizando los datos de CAMS y MODIS durante el periodo de tiempo de 2003 a 2015.  En este estudio se comparan los datos de MODIS y CAMS con datos obtenidos de las redes de monitoreo de calidad del aire de 3 ciudades de Colombia: Bogotá, Bucaramanga y Medellín. Se evaluaron los coeficientes de correlación (R) y el índice de correspondencia (IA) con el fin de evaluar el desempeño de los dos paquetes de datos (MODIS y CAMS). El análisis indica que hay una correlación estadisticamente significativa entre MODIS, CAMS y mediciones en superficie. Estos paquetes de datos pueden ser usados para analizar la calidad del aire en Colombia y en otros paises en via de desarrollo