Tropospheric Scintillation Signatures: Observations of the Possible Effect Thunderstorms have on GPS Signals

The Global Navigation Satellite System (GNSS) has wide applications from daily life to numerous industries. Understanding how space weather affects the radio signals is imperative to maintain its accuracy. Space weather events, such as geomagnetic storms, create a disturbance in the ionosphere by increasing the total electron content. However, these disturbances are found in high latitude regions where most studies are conducted; minimal research exists concerning the mid-latitude region. There is a gap in research focusing on how tropospheric sources such as thunderstorms might generate ionospheric structures that affect these signals as well. The purpose of this project is to fill that gap by analyzing the possible relationship between thunderstorms and scintillation. If a relationship is found, this could spark a whole new method of potentially predicting severe weather such as tornadoes and hurricanes. To study these relationships, 2 GPS receivers, both situated in Daytona Beach, Florida, were used to record GNSS data. A code was developed that graphed and analyzed the receiver data for scintillation signatures. Archived weather data was used to identify the exact date and time of thunderstorms. After favorable scintillation candidates were found, lightning location data was combed to compare it with the scintillation signatures. More accurate lightning data is required to determine a direct correlation to GPS scintillation, however, the current work lays a foundation to study relationship between tropospheric events and radio signal scintillation

Estado del sistema pensional Colombiano

ResumenEste artículo muestra el comportamiento que ha tenido el sistema pensional Colombiano.  A pesar de que la intención del sistema ha sido incrementar el número de cotizantes, lo cual se ha logrado. Esto no ha significado un aumento en el número de pensionados, ya que la flexibilización del mercado laboral ha tenido un impacto negativo en los mecanismos de protección del sistema pensional, generándose exclusión e inequidad en el sistema pensional colombiano para el periodo 2002 a 2014 que ha obligado al Gobierno Central a destinar para 2014 un 4.08% del PIB, para cubrir el déficit pensional, con la grave consecuencia que este porcentaje se utiliza para subsidiar las pensiones de cerca de un millón de personas, de altos ingresos, que solo equivalen aproximadamente al 2.5% de la población colombiana. AbstractThis article shows the behavior of the Colombian pension system. Although the intention of the system has been to increase the number of contributors, which has been achieved. This has not meant an increase in the number of  pensioners, since the flexibilization of the labor market has had a negative impact on the protection mechanisms of the pension system, generating exclusion and inequity in the Colombian pension system for the period 2002 to 2014 that has Forced the Central Government to allocate 4.08% of GDP in 2014 to cover the pension deficit, with the serious consequence that this percentageis used to subsidize the pensions of close to one million people, which are onlyabout 2.5% of the Colombian population

Análisis de la calidad del aire en diferentes ciudades de América Latina y el Caribe a partir de mediciones en superficie y datos del servicio de monitoreo atmosférico de Copernicus (CAMS)

Atmospheric pollution is one of the biggest environmental problems in the world. To evaluate and create action plans that improve air quality, measurements are needed that indicate the state of air quality, its trends, the pollutants of greatest concern and the regions most affected. However, to have air quality measurements it is necessary for governments to have policies and resources focused on this issue. For many years, developed countries have had data and programs to measure and improve air quality, but in regions such as Latin America and the Caribbean, many countries have so far started their measurement programs and in some cases they do not. According to the World Bank, global monitoring and modeling systems are a free source of information and can help to know the air quality in a specific region. CAMS is the atmospheric monitoring service of the Copernicus program and has models to know the atmospheric composition such as CAMS Reanalysis, CASMRA generates air quality and meteorological data with hourly and spatial temporal resolutions below 1° arc. Currently there are no works evaluating the CAMS data for Latin America and the Caribbean For these reasons, the main objective of this work was to analyze the air quality in different cities of Latin America and the Caribbean from surface monitoring, CAMSRA data and Tropomi satellite monitoring. Initially, data was sought in cities with more than one million inhabitants and later these data were spatially and temporally analyzed. The surface mediations were then evaluated and compared with the data from CAMSRA and Tropomi. Finally, satellite images identified areas with the highest level of pollutants in the region or places where more in-depth studies are needed. This work allowed the creation of a public database of 15 cities in the region with hourly periodicity for all pollutants by station. Also, it allowed to analyze for the first time multiple trends from 2000 to 2018 together thanks to the new Prophet tool. On the other hand, the performance of CAMS and Tropomi in Latin America and the Caribbean was evaluated for the first time and compared with surface data. Furthermore, it was possible to identify areas with high levels of contamination by means of satellite images of Tropomi. It was found that only 18% of cities with more than 1 million inhabitants measure air quality with good spatial and temporal resolution. From the analysis of the available surface measurements, it was found that, in general, in the cities analyzed, air pollution has decreased in the last two decades. However, all cities still exceed the recommendations by the World Health Organization for particulate matter. The results also indicate that the CAMSRA data only reproduce the trends and levels of particulate matter in some cities in Latin America and the Caribbean. It was also found that Tropomi in general reproduces well the trends of surface NO2 measurements, however, it does not adequately reproduce the behavior of particulate matter. Finally, it is concluded that global monitoring and modeling information is very valuable and very useful to analyze air quality problems in this region of the world or where there are still no air quality monitoring networks.La contaminación atmosférica es una de las mayores problemáticas medio ambientales en el mundo. Para evaluar y crear planes de acción que mejoren la calidad del aire se necesitan mediciones que indiquen cual es el estado de la calidad del aire, sus tendencias, los contaminantes de mayor preocupación y las regiones más afectadas. Sin embargo, para tener mediciones de calidad del aire es necesario que los gobiernos tengan políticas y recursos enfocados en este tema. Desde hace muchos años países desarrollados cuentan con datos y programas para medir y mejorar la calidad del aire, pero en regiones como América Latina y el Caribe muchos países hasta ahora inician sus programas de medición y en algunos casos no tienen. De acuerdo con el Banco Mundial los sistemas de monitoreo y modelación global son una fuente de información gratuita y pueden ayudar a conocer la calidad del aire en una región especifica. CAMS es el servicio de monitoreo atmosférico del programa Copernicus y cuenta con modelos para conocer la composición atmosférica como CAMS Reanálisis. CASMRA genera datos de calidad del aire y meteorológicos con resoluciones temporales horarias y espaciales inferiores a 1° de arco. Actualmente no existen trabajos que validen los datos de CAMS para América Latina y el Caribe. Por estos motivos, este trabajo tuvo como objetivo principal analizar la calidad del aire en diferentes ciudades de América Latina y el Caribe a partir de monitoreos en superficie, datos de CAMSRA y monitoreos de satelitales de Tropomi. Inicialmente se buscaron datos en las ciudades con más de un millón de habitantes y posteriormente se analizaron espacial y temporalmente dichos datos. Luego se evaluaron y compararon las mediciones en superficie con los datos de CAMSRA y Tropomi. Finalmente, por medio de imágenes satelitales se identificaron zonas con mayor nivel de contaminantes en la región o lugares donde se necesiten hacer estudios con mayor profundidad. Este trabajo permitió crear una base de datos publica de 15 ciudades de la región con periodicidad horaria para todos los contaminantes por estación. También, permitió analizar por primera vez múltiples tendencias desde el año 2000 hasta el año 2018 en conjunto gracias a la nueva herramienta Prophet. Por otra parte, se evaluó por primera vez el desempeño de CAMS y de Tropomi en América Latina y el Caribe y se compararon con datos en superficie. Además, se pudo identificar zonas con altos niveles de contaminación por medio de imágenes satelitales de Tropomi. Se encontró que solo el 18% de las ciudades con más de 1 millón de habitantes miden la calidad del aire con una buena resolución espacial y temporal. A partir del análisis de las mediciones de superficie disponibles se encontró que en general en las ciudades analizadas la contaminación del aire ha disminuido las últimas dos décadas. No obstante, todas las ciudades aun exceden las recomendaciones por la Organización Mundial de la Salud para material particulado. Los resultados también indican que los datos de CAMSRA solo reproducen las tendencias y los niveles del material particulado en algunas ciudades de América Latina y el Caribe. También se encontró que Tropomi en general reproduce bien las tendencias de las mediciones de NO2 en superficie, sin embargo, no reproduce adecuadamente el comportamiento del material particulado. Finalmente, se concluye que la información de monitoreo y modelación globales es muy valiosa y de gran utilidad para analizar los problemas de calidad del aire en esta región del mundo o donde aún no existen redes de monitoreo de calidad del aire.Línea de Investigación: Calidad del aireMaestrí

Manejo y aprovechamiento de los residuos sólidos orgánicos durante el periodo 2013-2016, en la Universidad Nacional

The objective of this study was to analyze the management and use of organic solid waste through generation rates by type of waste in the sodas of the Campus Omar Dengo of the National University of Costa Rica. The raw and cooked residues were collected in five sodas, weighed and based on this data, daily waste generation rates were calculated. In addition, a survey was conducted in order to determine the perception of users about this problem. It was evidenced that the amount of waste varied significantly during the sampling period and it varies in each soda. Social aspects, as well as quality and proximity, induce greater user assistance; therefore, the generation of waste is increased. It is concluded that it is necessary deeper studies that allow the reduction of waste, as well as the awareness of the users of the sodas.El objetivo de este estudio fue analizar la gestión y el aprovechamiento de los residuos sólidos orgánicos mediante tasas de generación, por tipo de residuos, en las sodas del Campus Omar Dengo. Se realizó la recolección de los residuos crudos y cocinados en cinco sodas, se pesaron y con base en estos datos se calculó la tasa de generación diaria de estos. Además, se realizó una encuesta con el fin de determinar la percepción de los usuarios sobre esta problemática. Se evidenció que la cantidad de residuos fluctuó significativamente durante el periodo de muestreo y en cada uno de los establecimientos. Los aspectos sociales, así como la calidad y cercanía inducen a mayor asistencia de los consumidores; por lo tanto, se incrementa la generación de residuos. Se concluye la necesidad de estudios más profundos que permitan la reducción de desperdicios, así como la concientización de los usuarios

Investigating the Correlation between GNSS Signal Scintillation and Thunderstorms

Global Navigation Satellite Systems (GNSS) have wide application in multiple sectors from daily life to industrial use. These sectors include navigation, timing, and positioning which all require a constant stream of accurate data. One aspect of maintaining the accuracy involves a deep understanding of the ionosphere and how it affects radio signals. This project takes into account an element that might impact the ionosphere: thunderstorms and their high-altitude lightning. Structures created in the ionosphere can cause scintillations, but finding if thunderstorms could initiate these structures is the main goal. Scintillation refers to fluctuations in the phase and amplitude of GNSS signals. There are some forms of lightning, such as blue jets and sprites, that have the ability to reach the ionosphere. This high-altitude lighting is thought to mostly occur in the tropics because of favorable conditions, but it has been observed in other latitudes. Lightning is shown to reach and affect the upper atmosphere, but the effect this could have on satellite signals is still under review. To record relevant scintillations, GNSS receivers have been situated in Daytona Beach, FL and the weather has been monitored for thunderstorms around the area. Receiver data is then graphed and analyzed for significant scintillations during the times of thunderstorms. Lightning location and time is also overlaid on a map with the satellite location plotted to further prove possible correlation between GNSS scintillations and lighting strikes. An evident correlation between scintillation signals and lightning strikes has been observed, but more evidence is needed to confirm this lightning could be the cause of the scintillation

From Big data to Smart Data with the K-Nearest Neighbours algorithm

The k-nearest neighbours algorithm is one of the most widely used data mining models because of its simplicity and accurate results. However, when it comes to deal with big datasets, with potentially noisy and missing information, this technique becomes ineffective and inefficient. Due to its drawbacks to tackle large amounts of imperfect data, plenty of research has aimed at improving this algorithm by means of data preprocessing techniques. These weaknesses have turned out as strengths and the k-nearest neighbours rule has become a core model to actually detect and correct imperfect data, eliminating noisy and redundant data, as well as correcting missing values. In this work, we delve into the role of the k nearest neighbour algorithm to come up with smart data from big datasets. We analyse how this model is affected by the big data problem, but at the same time, how it can be used to transform raw data into useful data. Concretely, we discuss the benefits of recent big data technologies (Hadoop and Spark) to enable this model to address large amounts of data, as well as the usefulness of prototype reduction and missing values imputation techniques based on it. As a result, guidelines on the use of the k-nearest neighbour to obtain Smart data are provided and new potential research trends are drawn

Culturability and viability of Salmonella typhimurium during photo-Fenton process at pH 5.5 under solar simulated irradiation

Culturability and viability techniques such as plate count on solid agar (PC), Most Probable Number (MPN) and Direct Viable Count-Fluorescence in Situ Hybridation (DVC FISH) were used to study the inactivation of Salmonella typhimurium by photo-Fenton process at pH 5.5. In the presence of only simulated solar irradiation (500 W·m−2), S. typhimurim showed that both culturability measured by MPN and viability (measured by DVC FISH) underwent just a slight decreasing of 2 and 1 log respectively after 240 min of light exposition while culturability measured by PC did not show any change. Results after 48 h of dark conditions did not reveal re-growth. However, when experiment was carried out in the presence of 2 mg L−1 of Fe3+ and 20 mg L−1 of H2O2 and pH 5.5, culturability was strongly affected after 240 min of simulated solar irradiation; nevertheless, viability was only slightly altered (~1 log). During dark period of 48 h changes on culturability and viability were not observed. On the other hand, it was also found that sugar metabolism was affected rather the amino-acids in S. typhimurium cells irradiated at different times upon photo-Fenton conditions. These findings might suggest for the first time that photo-Fenton process at pH 5.5 could induce viable but nonculturable state (VBNC) on waterborne S. typhimurium and that probably sugar metabolism damage could activate the VBNC state.Fil: Rengifo Herrera, Julian Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigación y Desarrollo En Ciencias Aplicadas; ArgentinaFil: Castaño, Olga L.. Universidad del Valle. Grupo de Investigación en Procesos de Oxidación Avanzada para Química y Tratamientos Biológicos; ColombiaFil: Sanabria, Irma Janeth. Universidad del Valle. Grupo de Investigación en Procesos de Oxidación Avanzada para Química y Tratamientos Biológicos; Colombi

Caracterización del servicio de consulta y préstamo documental del Archivo histórico de la UNAD, Sede Nacional José Celestino Mutis.

El presente trabajo de grado es la caracterización del servicio de consulta y préstamo documental, garantizando la definición de perfiles de usuario, herramientas de recuperación de búsqueda de información adecuadas para el correcto funcionamiento de este, adicionalmente se propone una estrategia para difundir la nueva estructura del servicio.The present work of degree is the characterization of the service of consultation and documentary loan, guaranteeing the definition of user profiles, tools of recovery of search of information adapted for the correct operation of this, additionally a strategy is proposed to spread the new structure of the service

Develando el vínculo entre la desigualdad y la pobreza

This paper attempts to reveal the relationship between inequality-poverty from the exposure of empirical and theoretical elements, which allows, on the one hand, to outline that the approach of both phenomena has generally been isolated; and on the other, to expose a proposal that shows the importance of recognizing the relationship between inequality-poverty to improve the society well-being. To validate the proposal, a simulation was carried out in which the instrumentalization of the Gini coefficient and the Poverty Lines was involved, showing as a result the existence of the relationship and that when applying redistribution mechanisms, such as limiting the tolerance threshold of inequality of income, poverty is reduced. Therefore, it is essential to defend the right to live in a more egalitarian society, since poverty persists, fundamentally, because of inequality.  Este artículo intenta develar la relación entre desigualdad-pobreza a partir de la exposición de elementos empíricos y teóricos, que permite, por un lado, plantear que la aproximación a ambos fenómenos ha sido generalmente aislada, y por otro, presentar una propuesta que muestra la importancia de reconocer la relación entre desigualdad-pobreza para mejorar el bienestar de la sociedad. Para validar la propuesta se hizo una simulación en la que se involucró la instrumentalización del coeficiente de Gini y las líneas de pobreza, y que mostró como resultado la existencia de la relación y que al aplicar mecanismos de redistribución, como limitar el umbral de tolerancia de la desigualdad de ingresos, se reduce la pobreza. Por ende, es imprescindible defender el derecho a vivir en una sociedad más igualitaria, puesto que la pobreza persiste, fundamentalmente, por la desigualdad