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High concentrations of particulate matter (PM) could significantly reduce the quality of useful life and human life expectancy. The origin, control, and management of the problem has made great steps in recent decades. However, the problem is still prominent in developing countries. In fact, often the number and spatial distribution of the air quality monitoring stations does not have an appropriate design, misleading decision makers. In the present research, an innovative assessment is proposed of the environmental, health and economic benefits corresponding to a 20% reduction in the PM2.5 concentration in the urban area of Cartagena de Indias, Colombia. Cases of mortality and morbidity attributable to fine particles (PM2.5) were estimated, with particular emphasis on mortality, emergency room visits and hospitalizations from respiratory diseases, in addition to their economic assessment using BenMAP-CE®. The novelty of using BenMAP-CE® in studying respiratory diseases and PM2.5 exposure in developing countries lies in its ability to provide a comprehensive assessment of the health impacts of air pollution in these regions. This approach can aid in the development of evidence-based policy and intervention strategies to mitigate the impact of air pollution on respiratory health. Several concentration-response (C-R) functions were implemented to find PM2.5 attributable mortality cases of ischemic heart and cardiopulmonary disease, lung cancer, respiratory and cardiovascular disease, as well as cases of morbidity episodes related to asthma exacerbation and emergency room/hospitalization care for respiratory disease. A 20% reduction would have avoided 104 cases of premature death among the population older than 30 in Cartagena, and around 65 cases of premature mortality without external causes., Depto. de Geografía, Fac. de Geografía e Historia, TRUE, pub

Two-phase transient flows in emptying processes of hydraulic pipelines with entrapped air have been studied in detail in the literature through the development of different mathematical models based on rigid column models. During literature review, it was found that transient flows representing pipeline emptying processes have been rarely studied by two-dimensional and three-dimensional analysis. This research begins demonstrating the behavior of air and water in pipelines during emptying processes, and the formulation of existing mathematical models, where two scenarios are considered: i) Emptying process of a branched hydraulic conduction with air valves, and ii) Emptying process of a simple hydraulic conduction without air valves. In this master thesis, two computational fluid dynamics (CFD) models were developed to study the hydraulic-thermodynamic parameters that occur in pipe emptying processes. An introduction to CFD modeling is performed for its use in the two-dimensional and three-dimensional analysis of two-phase transient flows. Subsequently, a 2D CFD model is performed to simulate Scenario No. 1 (branched hydraulic conduction with air valves), and a 3D CFD model is performed to simulate Scenario No. 2 (simple hydraulic conduction without air valves), described above. The geometric domains, meshing, boundary conditions, numerical schemes and calculation tolerances for the numerical solution of the Navier-Stokes equations for two-phase and compressible flows are defined for numerical processing. The 2D and 3D CFD models are validated with results obtained from experimental measurements carried out by other authors, and by means of a meshing sensitivity analysis. The CFD models show good correlation with the experimental results associated with pressure patterns, velocity, water column length, and allow to visualize in greater detail transient phenomena that are not captured by the mathematical models. These CFD models are compared numerically with their re

The dispersion of air pollutants and the spatial representation of meteorological variables are subject to complex atmospheric local parameters. To reduce the impact of particulate matter (PM2.5) on human health, it is of great significance to know its concentration at high spatial resolution. In order to monitor its effects on an exposed population, geostatistical analysis offers great potential to obtain high-quality spatial representation mapping of PM2.5 and meteorological variables. The purpose of this study was to define the optimal spatial representation of PM2.5, relative humidity, temperature and wind speed in the urban district in Cartagena, Colombia. The lack of data due to the scarcity of stations called for an ad hoc methodology, which included the interpolation implementing an ordinary kriging (OK) model, which was fed by data obtained through the inverse distance weighting (IDW) model. To consider wind effects, empirical Bayesian kriging regression prediction (EBK) was implemented. The application of these interpolation methods clarified the areas across the city that exceed the recommended limits of PM2.5 concentrations (Zona Franca, Base Naval and Centro district), and described in a continuous way, on the surface, three main weather variables. Positive correlations were obtained for relative humidity (R2 of 0.47), wind speed (R2 of 0.59) and temperature (R2 of 0.64)., Comisión Europea. ELARCH scholarship, Depto. de Geografía, Fac. de Geografía e Historia, TRUE, pub

[EN] The draining operation involves the presence of entrapped air pockets, which are expanded during the phenomenon occurrence generating drops of sub-atmospheric pressure pulses. Vacuum air valves should inject enough air to prevent sub-atmospheric pressure conditions. Recently, this phenomenon has been studied by the authors with an inertial model, obtaining a complex formulation based on a system composed by algebraic-di erential equations. This research simplifies this complex formulation by neglecting the inertial term, thus the Bernoulli¿s equation can be used. Results show how the inertial model and the simplified mathematical model provide similar results of the evolution of main hydraulic and thermodynamic variables. The simplified mathematical model is also verified using experimental tests of air pocket pressure, water velocity, and position of the water column.

An assessment of the rainfall station distribution in the mountainous area of the Regional Autonomous Corporation of Cundinamarca (CAR, for its acronym in Spanish), Colombia, was conducted by applying concepts from information entropy and artificial neural networks (ANNs). This study was divided into two phases: first, a classification of the meteorological stations using two-dimensional self-organizing maps; second, the evaluation of the performance of the ANN by applying concepts of information entropy. Three scenarios were raised for the classification of the meteorological stations by adjusting the number of neurons in the output layer. A high number of neurons in the output layer were obtained, causing the model to over-fit while emphasizing differences amid patterns. When comparing the results of the scenarios, the permanence of certain characteristics and features was found in the system, validating the model classification. Subsequently, the results of the first scenario were used to evaluate the entropy of the historical series. Finally, the results show that the area of study presents a lack of information due to the uncertainty associated with the probabilistic arrangement, which can be corrected with the developed model. Consequently, some recommendations for the redesign of the rainfall are provided

The draining operation involves the presence of entrapped air pockets, which are expanded during the phenomenon occurrence generating drops of sub-atmospheric pressure pulses. Vacuum air valves should inject enough air to prevent sub-atmospheric pressure conditions. Recently, this phenomenon has been studied by the authors with an inertial model, obtaining a complex formulation based on a system composed by algebraic-differential equations. This research simplifies this complex formulation by neglecting the inertial term, thus the Bernoulli’s equation can be used. Results show how the inertial model and the simplified mathematical model provide similar results of the evolution of main hydraulic and thermodynamic variables. The simplified mathematical model is also verified using experimental tests of air pocket pressure, water velocity, and position of the water column

This paper presents the physical-chemical evaluation of used engine oils from samples taken from industries that are located in Mamonal industrial sector in Cartagena de Indias. Among the characteristics taken into consideration it can be found: density, humidity percentage, viscosity, metals in suspension and high calorific value; some of the used methods were: densimetry, Karl fischer, viscosimetry, and atomic absorption. It can be highlighted that the analyzed samples didn’t report significant presence of tin, lead, chromium, silver and cadmium. The presence of calcium, magnesium, sodium, zinc and phosphorus can be due to additives added in order to improve their characteristics. The presence of chromium and iron in the samples is interpreted as a sign of wear in the parts. The presence of silicon can be provided by dust filtration. According to the above and proper treatment such oils are susceptible to recycle., En este trabajo se presenta la caracterización físico-química de aceites usados de motor de una muestra de empresas del sector industrial de Mamonal de la ciudad de Cartagena de Indias, entre las características tenidas en cuenta estuvieron: densidad, porcentaje de humedad, viscosidad, metales en suspensión y poder calorífico superior, algunos de los métodos utilizados fueron: densimetría, karlfischer, viscosimetría y absorción atómica. Se resalta que en las muestras analizadas no se reporta una presencia significativa de estaño, plomo, cromo, plata y cadmio. La presencia de calcio, magnesio, sodio, zinc, fósforo puede ser producto de los aditivos que se emplean para mejorar sus características. La presencia de Cromo y Hierro en las muestras se interpreta como indicio de desgaste de piezas. El silicio encontrado puede ser aportado por filtración de polvo. Acorde con lo anterior y un adecuado tratamiento estos aceites son susceptibles de reciclar

El monitoreo atmosférico es una de las etapas fundamentales en la identificación de estrategias para minimizar, prevenir y controlar los impactos de la dispersión de contaminantes en el aire, sobre la salud pública y el ambiente. Por tanto, el objetivo principal de este articulo consiste en proponer una metodología para la selección de sitios de monitoreo atmosférico en zonas urbanas afectadas por las emisiones de fuentes móviles. Primeramente se identificaron los sitios que presentaban mayor flujo vehicular y se priorizaron teniendo presente los siguientes criterios de selección: seguridad, influencia de otras fuentes, facilidad del montaje de los equipos, accesibilidad al sitio, identificación de barreras y obstáculos, registro histórico de datos y grado de concentración usando el software CALINE 3.La modelación agrupo datos característicos de las vías, meteorológicos y de flujo vehicular de un año típico de la zona en estudio. A cada uno de estos parámetros le es asignada una valoración cuantitativa, la cual define los sitios donde se realizará el monitoreo. Como resultados se desarrolló una guía para seleccionar los lugares en donde se puedan desarrollar campañas de monitoreo atmosférico asociadas a fuentes móviles. La metodología fue aplicada en la ciudad de Cartagena de Indias haciendo uso del modelo de calidad del aire CALINE3., Atmospheric monitoring is one of the fundamental steps in identifying strategies to minimize, prevent and control the impact of the dispersion of pollutants in the air, on public health and the environment. Therefore, the main objective of this article is to propose a methodology for selecting air monitoring sites in urban areas affected by emissions from mobile sources. First, the places with the highest vehicular flow were identified and prioritized according to the following selection criteria: safety, influence of other sources, ease of assembly of equipment, accessibility to the site, identification of barriers and obstacles, historical record of data and degree concentration of the pollutant: in this case carbon monoxide, using CALINE 3 software. The modeling grouped characteristic data related with roads, meteorology and vehicular flow of a typical year of the zone under study. A quantitative assessment is assigned to each of these parameters, which defines the sites where the monitoring will be performed. As a result, it was developed a guide to select those places where atmospheric monitoring campaigns related with mobile sources can be held. This methodology was applied in the city of Cartagena de Indias by using air quality model for assessment, CALINE 3