The pandemic against the poor: Mexico City and COVID-19

In Mexico City, COVID-19 has spread in line with existing patterns of spatial segregation and inequalities. While the poorest neighbourhoods have been the hardest hit, many of the wealthiest have seen very few cases, writes Máximo Ernesto Jaramillo Molina (INDESIG and Atlantic Fellows for Social and Economic Equity)

Restauración de un banco didáctico para la enseñanza de los motores de combustión interna a gasolina

En el Laboratorio De Motores de la Universidad Tecnológica de Pereira, se encuentra un motor de Simca 1000 centímetros cúbicos seccionado por la Escuela de Tecnología Mecánica como parte de un trabajo de curso. La calidad de dicho trabajo lo posiciona como una herramienta muy importante para la difusión del conocimiento y entendimiento del funcionamiento del motor de combustión interna a gasolina. Sin embargo, ese material didáctico que facilita el estudio del motor se encontró deteriorado, sus mecanismos atascados, y con una funcionalidad limitada por el uso en el transcurso de los años. En ese estado se dificulta la explicación del funcionamiento de los mecanismos y sistemas por parte de los profesores y se dificulta su entendimiento. Además, el motor posee una tecnología que para el día de hoy es obsoleta; debido a esto se busca devolver el funcionamiento e implementar, en lo posible, un sistema de inyección didáctico básico con el fin de facilitar un tipo de tecnología que se usa en motores modernos y que ofrece ventajas en consumo de combustibles, en potencia entregada, y reducen la contaminación ambiental y la polución

Evaluation of a mass media health education campaign for tuberculosis control in Cali, Colombia

Tuberculosis is a world-wide problem in less developed countries. In this thesis I report\ud the evaluation of impact, process and objectives of a mass media health education\ud campaign for tuberculosis control developed in Cali, Colombia. The campaign aimed at\ud reducing levels of prejudice against people with this disease and at increasing demand\ud for diagnostic tests.\ud I assessed impact on levels of prejudice using two cross sectional surveys as sources of\ud data. I assessed impact on demand for diagnostic tests with a quasi-experimental\ud evaluation design relying on epidemiological data. I used qualitative and quantitative\ud techniques for assessing the process of the campaign. I used text analysis for assessing\ud the objectives of the campaign, and for identifying the values underpinning these\ud objectives.\ud The results show that the campaign significantly reduced the prejudice, and increased\ud the demand for tests. Process evaluation shows that the campaign managers applied\ud satisfactorily the programme theory of the intervention, that around half of the\ud population was exposed to the campaign, and that it aimed exclusively at reinforcing a\ud medical approach to tuberculosis control, which promoted compliance with medical\ud surveillance, instead of contributing to the creation of an educated public regarding this\ud disease. Assessment of objectives showed that the values underpinning the campaign\ud are Utilitarian which define the worth of human life in terms of its economic\ud productivity.\ud This thesis demonstrates that current evaluation models of health education, which draw\ud only on impact and process, are inappropriate for all those who have an interest at stake\ud in the programme in order to judge its worth and to take policy decisions. Health\ud education programmes are responses to social problems based on a specific idea of what\ud is worthwhile to be pursued by individuals and society. Thus, evaluation research in\ud health education should include not only assessment of impact and process but also\ud assessment of their objectives in order to unveil the values underpinning such responses

Analysis of the value chain: problems of the exploitation of tilapia and trade with Spain and Colombia

RESUMEN: El presente trabajo fin de máster pretende analizar y realiza el mapa de cadena de valor de la tilapia entre Colombia y España, determinando sus etapas (producción, distribución y comercialización), y calculando el margen de ganancia para cada una ellas. Para esto, se han analizado todos los costes de cada etapa y los precios de venta del producto, determinando que el margen de ganancia de cada etapa varía, por lo que las ganancias de los productores, en porcentaje, no es igual a la de los comercializadores, ya que su precio sube en más del 100%, pasando de un precio de venta de 2.40€ en Colombia, a uno de 10.91€ en España. De los resultados surge es un sector que en Colombia esta en crecimiento, pero que, para ser más competitivos, darle valor agregado al producto de la tilapia fresca o al filete de tilapia, controlar las enfermedades y también tener una buena estructura de costes eficienteABSTRACT: This project aims to analyze the map of the tilapia value chain between Colombia and Spain, determining its stages (production, distribution and marketing) and calculating the profit margin for each of them. For this, all the costs of each stage and the sale prices of the product have been analyzed, determining that the profit margin of each stage varies, so that the profits of the producers, in percentage, is not equal to that of the producers. retailers, since its price rises by more than 100%, going from a sale price of €2.40 in Colombia, to €10.91 in Spain. From the results emerges is a sector that in Colombia is growing, but to be more competitive, give added value to the product of fresh tilapia or tilapia fillet, control diseases and also have a good efficient cost structure.Máster en Dirección de Empresas (MBA

Diseño de un sistema de control difuso de seguimiento solar de dos ejes.

Se diseñó un sistema de seguimiento solar de dos ejes con control difuso que aproveche de mejor manera la radiación solar, la propuesta tecnológica y de innovación implementa un sistema de seguimiento solar de dos ejes controlado por un algoritmo difuso, el mismo permite seguir al sol en toda su trayectoria durante el día, dando una mayor optimización de la captación de la energía solar con respecto a los paneles solares de orientación fija que son los más comúnmente utilizados en nuestro país. El control difuso se lo realiza desde una plataforma desarrollada en LabVIEW, en este se ha implementado el ingreso de dos señales correspondientes al error de posición tanto en latitud como en azimut y dos señales de salida generadas en el control difuso para controlar a dos motores de pasos que permiten corregir estos errores, dando como consecuencia, un seguimiento continuo de la trayectoria solar, el sistema difuso corresponde a un sistema MIMO (múltiple entrada, múltiple salida). Para verificar la hipótesis de que un panel solar ubicado en un seguidor solar de dos ejes aprovecha de mejor manera la energía solar con respecto a un panel ubicado con una orientación fija se construyó un prototipo, en él se montó un panel solar y se tomó las lecturas de la incidencia solar durante tres días a intervalos fijos se comparó las medidas captadas por el panel ubicado en el seguidor y en el panel fijo luego, luego se realizó la prueba no paramétrica de U de Mann-Whitney que compara medianas y no medias ya que la distribución luminosa dada por el sol no tiene una distribución normal El sistema propuesto permitió obtener un rendimiento mayor en un 10.66 % de captación de energía solar con respecto a de un panel fijo. En siguientes trabajos se podrá tomar como referencia la presente investigación para investigar sobre la aplicación de otros posibles algoritmos de control como por ejemplo un control PID continuo, PID digital o sobre un control discreto, etc.In this study, a two-axis solar tracking system with diffuse controller was designed to make the best use of solar radiation, the proposed technology and innovation implemented a solar tracking system of axes controlled by diffuse algorithm. This system allows the sun´s trajectory to be followed throughout the entire day, to optimize capturing solar energy in comparison to fixedorientation solar panels, which are the most commonly used in or country. The diffuse control is implemented via a platform developed in LabVIEW. This control involves the entry of two signals corresponding to the position error with both latitude an azimuth and two output signals generated in the diffuse control to control two stepper motors that allow for these errors to be corrected, resulting in continuous monitoring of the solar path. The diffuse system corresponds to the MIMO system (multiple input, multiple output). In order to verify the hypothesis that a solar panel located on a two-axis solar tracker makes better used of solar energy as compared to a fixed-orientation panel, a prototype was constructed. A solar panel was mounted and solar readings were taken for three days at fixed intervals. The measurements taken from the panel located on the tracking system and the fixed panel were compared, then the nonparametric Mann-Whitney U test was used, which compares medians and not means, as the distribution given by the sun does not have a normal distribution. The proposed system had a higher yield with 10.66% solar energy uptake obtained as compared to a fixed panel. In future research this present study can be taken as a reference to investigate the application of other possible control algorithms, for example a continuous PID controller, digital PID controller or a discrete controller

Propuesta de un modelo espacial con valores económicos para la recuperación de cuencas urbanas en el Municipio de Medellín

RESUMEN: La recuperación de cuencas urbanas, cada vez cobra más importancia a nivel mundial y por tal motivo en esta monografía se pretende elaborar un modelo espacial con la ayuda de herramientas Sistemas de Información Geográficos – SIG- que permita identificar las zonas que deben ser intervenidas en compra de predios, demolición de infraestructura, implementación de servicios públicos, paisajismo, entre otras, y determinar los costos que deben ser invertidos para lograr su mejoramiento.Conociendo las áreas a intervenir y las longitudes de redes de servicios públicos a implementar, se puede cuantificar su valor, al afectarlos por los costos unitarios de cada actividad y con esto, poder priorizar las acciones a realizar, facilitando a la vez la toma de decisiones por parte de los entes estatales.Submitted by Patrimonio CENDOI ([email protected]) on 2020-02-11T20:11:02ZNo. of bitstreams: 2license_rdf: 823 bytes, checksum: b88b088d9957e670ce3b3fbe2eedbc13 (MD5)LopezCamilo_2019_ModeloEspacialValores.pdf: 816180 bytes, checksum: abac9a1b9cb0221cb1cf17ac8a7e0426 (MD5

La pandemia contra los pobres: la Ciudad de México, y COVID-19

En la Ciudad de México, el contagio de casos por COVID-19 ha seguido un patrón de segregación geográfica, donde las colonias de estrato social más bajo han sido las más afectadas, mientras que la mayor parte de las colonias de estrato alto no han presentado muchos casos, escribe Máximo Ernesto Jaramillo Molina (INDESIG y Atlantic Fellows for Social and Economic Equity)

Suitability of different RANS models in the description of turbulent forced convection flows: application to air curtains

The main motivation of this thesis is the analysis of turbulent flows. Turbulence plays an important role in engineering applications due to the fact that most flows in industrial equipment and surroundings are in turbulent regime. The thesis has a double purpose and is divided in two main parts. The first one is focussed on the basic and fundamental analysis of turbulence models. In the second part the know-how acquired in the first part is applied to the study of air curtains.Regarding to the first part, the principal difficulty of computing and modelling turbulent flows resides in the dominance of non-linear effects and the continuous and wide spectrum of time and length scales. Therefore, the use of turbulence modelling employing statistical techniques for high Reynolds numbers or complex geometries is still necessary. In general, this modelization is based on time averaging of the Navier-Stokes equations (this approach is known as Reynolds-Averaged Navier-Stokes Simulations, RANS). As consequence of the average new unknowns, so-called Reynolds stresses, arise. Different approaches to evaluate them are: i) Differentially Reynolds Stress Models (DRSM), ii) Explicit Algebraic Reynolds Stress Models (EARSM), and iii) Eddy Viscosity Models (EVM).Although EVM models assuming a linear relation between the turbulent stresses and the mean rate of strain tensor are extensively used, they present various limitations. In the last few years, with the even-increasing computational capacity, new proposals to overcome many of these deficiencies have started to find their way. Thus, algebraic or non-linear relations are used to determinate the Reynolds stress tensor without introducing any additional differential equation.Therefore, the first part of this thesis is devoted to the study of several EARSM and EVM models involving linear and higher order terms in the constitutive relation to evaluate turbulent stresses. Accuracy and numerical performance of these models is tested in different flow configurations such as plane channel, backward facing step, and both plane and round impinging jets. Special attention is paid to the verification of the code and numerical solutions, and the validation of the mathematical models used. In the impinging plane configuration, improvements of models using higher order terms in the constitutive relation are limited. Whereas, in the rest of studied cases these non-linear models show a reasonably good behaviour.Moreover, taken into account models convergence, robustness and predictive realism observed in the analysis of these benchmark flows, some of them are selected for the study of air curtains and their interaction with the environment where they are placed. Air curtains are generally one or a set of vertical or horizontal plane jets used as ambient separator of adjacent areas presenting different conditions. The jet acts as a screen against energy losses/gains, moisture or mass exchanges between the areas.As was indicated before, the main purpose of the second part of this thesis is to characterize in detail actual air curtains using both experimental and different numerical approaches. Semi-empirical models to design air curtains are presented. Then, an experimental set-up used to study air curtain discharge and jet downstream is explained. Experimental measurements of velocity and temperature are shown. As a result of the experiments carried out, an improved air curtain with a new design of the discharge nozzle is obtained. Furthermore, air curtain experiments are numerically reproduced and predictions validated against the experimental data acquired. Good agreement between numerical and experimental results is observed.Finally, systematic parametric studies of air curtains in heating and refrigeration applications are done. Global energetic balances are specially considered together with global parameters selected in order to evaluate air curtain performance. It is found that discharge velocity, discharge angle and turbulence intensity of the jet are the most sensitive parameters. Inadequate values for these variables can produce undesirable effects and contribute to increase energy gains/losses