Mi historia obstinada. My obstinate history; an intercultural testimony of my own diaspora

In this thesis, I explore the journey between my worlds, the North and the South, examining the politics and poetics of diaspora. In this process I’ve assembled an archive of memory that has been complied over many years. This archive is a collection of memories and artefacts, of items that I still keep as well as items that were left behind a long time ago, and whose imprints are still very much alive in me. Furthermore, this thesis deals with art in Chile that arose out of the tumultuous period of unrest and unbalance following the rise of the dictatorship in 1973. In this thesis, I deal with artists such as Alfredo Jaar, Lotty Rosenfeld, and Eugenio Dittborn, among others. The work of these artists during this artistic period of resistance is constantly imprinted with signs and codes, as well as staunchness and obliqueness, marking a pivotal role in the continued resistance to the oppressors. Likewise, throughout this thesis I examine the ideas and the prevalently latent shift or “in-betweeness” that exists in the narrative of diaspora and in my own narrative as well. Here, I examine the works of artists, cultural theorists and writers including Stuart Hall, Edward Said, Nelly Richard, James Luna, and Salman Rushdie (among others) to reflect on how their work has influenced, shaped and directed my study of Diaspora, and to a greater extent, my understanding of the politics of it. Likewise, throughout his thesis I work to understand of the heterogeneous yet situated bodies of knowledge and experience that make up the contemporary cultural archive of diaspora. This includes various definitions of diaspora that both interrupt the text as well as enrich it

Exergy analysis of a flat plate solar collector with latent heat storage by phase change material for water heating applications at low temperature

An exergy analysis has been performed to determine the potential for useful work in a latent heat storage system with phase change material (PCM) for a flat-plate solar collector. Commercial paraffin wax is used as PCM to store and release energy in the solid-liquid transformation; this material is located in metal containers under the absorber plate on the bottom insulation of the collector. The exergy analysis is performed in outdoor conditions for days of the low, medium and high radiation taken from October 2016 to March 2017 at Barranquilla city (latitude: 10º 59' 16" N, longitude: 74º 47' 20" O, Colombia). The system is evaluated throughout charge and discharge periods. The energy and exergy balance equations based on the first and second law of thermodynamics is formulated and solved for each element of the collector system as well as for the PCM. Results obtained show the energy distribution and energetic destruction for each system component and its variation as a time function. It was observed that the average energy and energetic efficiency are 28.7 %, 13.2 % for of low radiation days. 26.9%, 20.56% for of medium radiation days, and 23.2%, 18.6% for of high radiation days, respectively. Results of the analysis are shown in detail in the present paper

Hacia una inclusión educativa en la enseñanza de las matemáticas

La enseñanza de las matemáticas en un contexto de inclusión escolar supone un reto para el sistema educativo en la actualidad. El iniciar a inducir contenidos formales y de un nivel de abstracción elevado en un contexto de estudiantes con necesidades educativas especiales supone un cambio en la forma que se presentas estos contenidos. El presente trabajo describe el diseño, puesta en práctica y análisis de una propuesta de enseñanza de la geometría analítica con estudiantes del grado decimo del colegio Euskadi (Colombia). Logrando analizar las implicaciones de la metodología aula taller y el papel fundamental de la geometría como mediación entre el mundo real y las matemáticas

Experimental analysis of a flat plate solar collector with integrated latent heat thermal storage

In the present paper, an experimental analysis of a solar water heating collector with an integrated latent heat storage unit is presented. With the purpose to determine the performance of a device on a lab scale, but with commercial features, a flat plate solar collector with phase change material (PCM) containers under the absorber plate was constructed and tested. PCM used was a commercial semi-refined light paraffin with a melting point of 60°C. Tests were carried out in outdoor conditions from October 2016 to March 2017 starting at 7:00 AM until the collector does not transfer heat to the water after sunset. Performance variables as water inlet temperature, outlet temperature, mass flow and solar radiation were measured in order to determine a useful heat and collector efficiency. Furthermore, the operating temperatures of the glass cover, air gap, absorber plate, and PCM containers are presented. Other external variables as ambient temperature, humidity and wind speed were measured with a weather station located next to the collector. The developed prototype reached an average thermal efficiency of 24.11% and a maximum outlet temperature of 50°C. Results indicate that the absorber plate reached the PCM melting point in a few cases, this suggests that the use of a PCM with a lower melting point could be a potential strategy to increase thermal storage. Thermal analysis and conclusions of the device performance are discussed

Numerical Analysis of Melting and Holding Furnaces in Secondary Aluminum Production

En esta tesis, dos hornos de aluminio diferentes se analizan numéricamente: 1) un nuevo prototipo de horno de fundición; 2) un nuevo prototipo de horno de mantenimiento. Estos dispositivos son claves en la producción de aluminio secundario. Los modelos utilizados tienen en cuenta la conducción de calor en las partes sólidas, la convección en el aire y de aluminio fundido, las interacciones entre las zonas de gas-líquido-sólido, cambio de fase de la carga y la transferencia de calor por radiación. Con el objetivo de desarrollar una herramienta de cálculo para asistir en el diseño y escalado de hornos industriales, se evalúan diferentes estrategias de cálculo concernientes a la economía computacional y su precisión de cálculo de diferentes parámetros importantes. Las estimaciones de las temperaturas en los hornos se comparan con las mediciones experimentales realizadas en prototipos reales en ciclos de operación típicos

Experimentally based testing of the enthalpy-porosity method for the numerical simulation of phase change of paraffin-type PCMs

The enthalpy-porosity method is generally applied as an economical resort for the numerical simulation of phase change materials (PCMs). However, having been developed strictly for metals, its suitability for the task is unclear, nor is the rationale for assigning its internal parameters, e.g., latent enthalpy and the constant of the momentum source term representing the “mushy” region. We first experimentally and exhaustively characterize a paraffin-type PCM, including differential scanning calorimetry (DSC) at several heating rates, T-history, and fusion visualization. Then, we develop a numerical model and systematically run simulations under different internal parameters and thermophysical properties of the PCM. Simulation results exhibit significant disagreement with experiments that cannot be reduced by any strategy for combining different material properties and model parameters. Among other effects, the constant of the momentum source term, which has to be assigned somewhat arbitrarily, has more relevance in the accuracy than any set of properties obtained by DSC and other experimental techniques. Thus, a rather negative, although interesting, conclusion is suggested: the enthalpy-porosity method may fail to model the phase change of paraffin-type PCMs. This is, of course, of paramount importance for the studies of their utilization in practical systems since it puts a fundamental point of uncertainty in any numerical study or lumped-type model derived thereof. The paper concludes with a tentative discussion of the possible causes of this failure and perspectives for developing more proper models

Determinantes sociales de la salud: un análisis desde el contexto colombiano

 Un amplio e interesante desarrollo acade?mico, junto a una creciente preocupacio?n y con- ciencia, se ha evidenciado durante las u?ltimas de?cadas respecto a la influencia de los factores sociales, econo?micos y culturales sobre la salud. El enfoque de los determinantes sociales de la salud (DSS) surgio? como un nuevo paradigma en el abordaje de las inequidades en salud (es decir, las diferencias de salud por grupo racial o e?tnico o por factores socioecono?micos como ingresos y educacio?n) para los hacedores de poli?ticas pu?blicas y la sociedad en general a causa de cierto grado de escepticismo acerca de la idoneidad de los criterios tradicionales de abordaje del proceso salud-enfermedad. Sin embargo, la relacio?n entre los factores sociales y de salud no son sencillos, pues existen mu?ltiples variables que se deben tener en cuenta para establecer posibles relaciones causales entre estos; por lo que hay controversias sobre la fuerza de la evidencia que apoya un papel causal de algunos factores sociales y econo?micos en el estado de salud. A pesar de la creciente importancia concedida en la actualidad al enfoque de los DSS, para muchos es todavi?a una perspectiva poco conocida y profundizada. Este arti?culo revisa la literatura existente hasta el momento y hace un ana?lisis de la imple- mentacio?n de este paradigma en el contexto colombiano

Experimental Analysis of a Flat Plate Solar Collector with Integrated Latent Heat Thermal Storage

In the present paper, an experimental analysis of a solar water heating collector with an integrated latent heat storage unit is presented. With the purpose to determine the performance of a device on a lab scale, but with commercial features, a flat plate solar collector with phase change material (PCM) containers under the absorber plate was constructed and tested. PCM used was a commercial semi-refined light paraffin with a melting point of 60°C. Tests were carried out in outdoor conditions from October 2016 to March 2017 starting at 7:00 AM until the collector does not transfer heat to the water after sunset. Performance variables as water inlet temperature, outlet temperature, mass flow and solar radiation were measured in order to determine a useful heat and the collector efficiency. Furthermore, operating temperatures of the glass cover, air gap, absorber plate, and PCM containers are presented. Other external variables as ambient temperature, humidity and wind speed were measured with a weather station located next to the collector. The developed prototype reached an average thermal efficiency of 24.11% and a maximum outlet temperature of 50°C. Results indicate that the absorber plate reached the PCM melting point in few cases, this suggests that the use of a PCM with a lower melting point could be a potential strategy to increase thermal storage. A thermal analysis and conclusions of the device performance are discussed

El enfoque en la atención al cliente a partir del desarrollo de los factores motivacionales, en el clima organizacional de una empresa de servicios jurídicos

Tesis de maestría -- Universidad de Costa Rica. Posgrado en Administración y Dirección de Empresas. Maestría Profesional en Administración y Dirección de Empresas con énfasis en Gerencia, 2005El objetivo general del trabajo es analizar la importancia que ejercen los factores motivacionales en el mejoramiento del clima organizacional de la empresa estudiada y su enfoque en la relación con los clientes, de manera que se preste estos servicios jurídicos de la mejor forma, con un alto sentido humanitario y profesional, superando las expectativas de los usuarios y haciéndoles sentir el honor y agrado que se produce, al ofrecerles la labor profesional con gran esmero y dedicación. La organización investigada se dedica a la prestación de servicios jurídicos. Se especializa en la rama del Derecho Corporativo. Es una joven empresa, de tamaño pequeño, en la que actualmente con mucho entusiasmo se ofrece un servicio que la compañía considera es de alta calidad. Este es el enfoque actual de la empresa, el prestar un servicio de alta calidad en su forma. Para ello el proyecto desarrolla una investigación de tipo documental, exploratoria, de diagnóstico y sintética. Documental, pues se parte del desarrollo doctrinal de temas tales como los factores motivacionales, el clima organizacional y el servicio al cliente. Luego, se explora lo que sucede en el mercado costarricense y en la empresa objeto de esta investigación. Se diagnostica la empresa y sus políticas. Y finalmente, se sintetiza y recomienda el enfoque en el servicio al cliente, a partir de un clima organizacional motivado. Dentro de sus principales conclusiones se encuentra que la entidad debe enfocarse a la satisfacción de sus clientes. Un servicio que se considere de alta calidad formal y por esto sea por parte de la misma empresa, no tiene valor si los clientes, destinatarios finales de este servicio, no lo consideran así, por la falta de esmero por parte de la firma en satisfacer y superar sus expectativas. Con base en todo lo anterior, se recomienda que la firma enfoque su motivación interior a la satisfacción de sus clientes, más que a la calidad formal del servicio. Con el fin de que la empresa cumpla con este cometido, debe modificar su misión, visón y objetivos organizacionales, de tal forma que se enfoquen en el cliente. Asimismo, se recomienda que la compañía adopte un organigrama organizacional y políticas, orientadas hacia el cliente.Universidad de Costa Rica. Posgrado en Administración y Dirección de EmpresasUCR::Vicerrectoría de Investigación::Sistema de Estudios de Posgrado::Ciencias Sociales::Maestría Profesional en Administración y Dirección de Empresas con énfasis en Gerenci

The Role of <em>Pseudomonas aeruginosa</em> RNA Methyltransferases in Antibiotic Resistance

Methyltransferases play a fundamental role in aminoglycoside resistance of Gram-negative bacteria, and some of its mechanisms were described in the past years, especially in Escherichia coli; however, it remains unsolved for other resistant bacteria such as Pseudomonas aeruginosa. Despite hurdles to determine resistance acquisition, high-throughput approaches (genomics, transcriptomics, and proteomics) have allowed data mining and analysis in a systemic way. Likewise, bioinformatics modelling of homologous genes or proteins has permitted to elucidate the emerging resistance in this pathogen. P. aeruginosa is a bacterial resistance treat since practically all known resistance mechanisms can be described using this model, particularly RNA methyltransferases. The RNA methyltransferases perform methylation or demethylation of ribosomal RNA to allow or restrict the antibiotic resistance development. The Kgm and Kam methyltransferases families are found in P. aeruginosa and confer resistance to several aminoglycosides. Loss of native methylations may also confer a resistant phenotype. The P. aeruginosa RsmG has high structural homology with Thermus aquaticus protein. Today, molecular data will promote a new paradigm on antibiotic therapy for treatment against P. aeruginosa. This chapter provides an overview of what role P. aeruginosa’s methyltransferases play in antibiotic resistance, induced by methylation or demethylation in the ribosome