Optimization of composite tubes for a thermal optical lens housing design

This thesis describes the manufacturing, structural analysis and testing of a composite cylinder for space application. This work includes the design and fabrication of a reusable multicomponent mandrel made of aluminum and steel and the manufacturing of a carbon fiber reinforced tube in an epoxy resin matrix. This structure intends to serve as the optical lens housing onboard a spacecraft. In addition, some future work needs to be done before this component is certified. The objective is to determine if the composite meets the stiffness and strength requirements for lens housing. The structural analysis is made by means of a finite element model simulating the true boundary conditions. The testing includes the design of a fixture to allow the composite cylinder to be mounted in one the testing machines at the Department of Aerospace Engineering at Texas A&M University and the preparation for the actual test. The response to the experimental analysis will be compared to the numerical simulation to verify the results

Health and Safety in 3D Printing

Nowadays, it is possible to find 3D printers everywhere, at homes, schools, work offices, etcetera. 3D printing is an additive manufacturing process that is increasingly gaining popularity, and it can create functional parts with a wide variety of shapes and sizes. But on the other hand, there are health risks associated with 3D printers, like nanoparticles and volatile organic compounds (VOCs), which are important to know to improve health and safety and avoid diseases such as asthma, allergic rhinitis and chronic obstructive pulmonary disease, among others. This chapter analyses techniques for sampling the nanoparticles and VOCs exposure during 3D printing and a health effects review, giving tools to evaluate the risks and recommendations to avoid or minimise these risks using engineering controls like extraction systems or good ventilation

Determinantes del desplazamiento forzado en el departamento del Meta

Maestría en Economía, Facultad de Ciencias Contables, Económicas y Administrativas.El presente documento estudia los determinantes del desplazamiento forzado y su relación con la tasa de informalidad de la tierra, los ataques terroristas, el número de homicidios y los cultivos de coca en el departamento del Meta durante la primera década del siglo XXI. El estudio presenta los resultados obtenidos a partir de las estadísticas descriptivas, donde se utilizaron las cifras del panel municipal del CEDE de la Universidad de los Andes para determinar la estructura de la propiedad rural. Se realizó una aproximación a partir de la estimación de un modelo de datos panel, para analizar los determinantes del desplazamiento forzado durante el periodo 2003 – 2011 como consecuencia de la intensificación del conflicto armado a nivel departamental

Effect of microencapsulated phenolic compound extracts of Maclura tinctoria (L.) Steud on growth performance and humoral immunity markers of white leg shrimp (Litopenaeus vannamei, Boone, 1931) juveniles

Aim of study: The effect of microencapsulated phenolic compound extracts of Maclura tinctoria (MTBE) on growth performance and humoral immunity markers of the white leg shrimp Litopenaeus vannamei juveniles (0.5 ± 0.2 g initial weight) was studied.Area of study: M. tinctoria was collected from Hampolol, Campeche, and Arroyo del Agua, Culiacan, Sinaloa, Mexico.Material and methods: Three MTBE inclusions (0.5, 1, and 2.5 g MTBE/kg, Purina®) were compared with a control commercial feed (Purina®) during 30 days. Nine phenolic acids, nine flavonols, four dihydro-flavonoids, four flavones, and seven unidentified phenolic compounds were determined fin the MTBE using a Perkin Elmer® HPLC chromatograph and diode array-detection.Main results: The mean concentrations of total phenolic compounds, total flavonoid compounds, and condensed tannins were 198.05 ± 5.59 mg gallic acid equivalent (GAE) g-1 dw, 78.57 ± 1.80 quercetin equivalent g-1, and 28.32 ± 0.33 mg epicatechin equivalent g-1, respectively. The ferric reducing antioxidant power and the total antioxidant capacity, respectively, averaged 28.32 mg GAE mL-1 and 10.9 mg ascorbic acid equivalent mL-1. Survival, weight gain, and specific growth rate of L. vannamei were similar among the experimental diets. The dietary inclusion of MTBE at 0.5 g/kg of food showed significant higher (p < 0.05) plasma hemocyte lysate protein (1.35 ± 0.055 µg mL-1), prophenoloxidase (0.47 ± 0.15, Abs. 492 nm), and superoxide anion (O2.-) activity (0.21 ± 0.07, Abs. 630 nm).Research highlights: The supplementation of MTBE at 0.5 g/kg of food could be considered as a potential alternative additive for L. vannamei diet in the juvenile production, since it improved the response of the humoral immunity markers at post larval life stages, when cultivated shrimp are more susceptible to be infected by pathogens

Contextualizing Kindergarten Readiness Data: A Qualitative Research Study of the Highland Neighborhood in Spartanburg, South Carolina

This project was undertaken as a result of conversations initiated by members of the Spartanburg Academic Movement (SAM) about the desirability of qualitative data to contextualize quantitative data generated by the use of a validated national instrument in Spartanburg County Schools. SAM is a nonprofit and community movement that facilitates the discussion of shared information and intentional, collaborative, and strategic work by cross-sector partnerships in order to foster high levels of academic attainment for all children in Spartanburg County. As part of data-gathering efforts by SAM, the Early Development Instrument (EDI) was implemented to gather data about kindergarten readiness first in Spartanburg School District 7, then in 2017, across all seven Spartanburg County school districts. The Highland census tract (census tract 208) in Spartanburg, South Carolina, encompasses a neighborhood landscape with distinct residential zones, identities, and dynamics. The Highland landscape at the time of our data collection includes spaces of positivity and neighborhood engagement: public spaces for recreation, like Stewart Park, and community resources like the Bethlehem Center and Thornton Center. It also is comprised of places, like Norris Ridge, Prince Hall, and certain streets, that residents associated with challenges. In some residential zones,such as Norris Ridge, residents enter and leave the neighborhood with frequency. there is a strong element of impermanence and transience, as ne

Contextualizing Kindergarten Readiness Data: A Qualitative Research Study of Forest Park Neighborhood in Spartanburg, South Carolina

This project was undertaken as a result of conversations initiated by members of the Spartanburg Academic Movement (SAM) about the desirability of qualitative data to contextualize quantitative data generated by the use of a validated national instrument in Spartanburg County Schools. SAM is a nonprofit and community movement that facilitates the discussion of shared information and intentional, collaborative, and strategic work by cross-sector partnerships in order to foster high levels of academic attainment for all children in Spartanburg County. As part of data-gathering efforts by SAM, the Early Development Instrument (EDI) was implemented to gather data about kindergarten readiness first in Spartanburg School District 7, then in 2017, across all seven Spartanburg County school districts. The EDI is a validated, population-based measure of early child development in five key domains (physical health, emotional maturity, social competence, language and cognitive skills, and communications skills and general knowledge).1 Kindergarten teachers respond to the questions on the EDI for each child in a kindergarten clas

Crustal and Mantle Structure Beneath the Southern Payenia Volcanic Province Using Gravity and Magnetic Data

The Auca Mahuida volcanic field lies on the southernmost Payenia Volcanic Province, one of the broadest retroarc volcanic plateaux in the southern Central Andes (~38°S). This voluminous basaltic flooding of Quaternary age was originated from a deep asthenospheric source, interpreted as a mantle plume product of changing slab dynamics. The geometry of this source is deduced from magnetotelluric data, but the limited spatial coverage of this array does not allow a detailed resolution of this anomaly. In order to present a detailed geometry of the conductive anomaly and related crustal magmatic bodies, we used multiple data sources. We combined Magnetic and Bouguer anomalies, Curie isotherm depth (T c ), Elastic Thickness (T e ) and Moho depth derived from the Global Earth Magnetic Anomaly Grid (EMAG2) and terrestrial gravity measurements, all together in a holistic geophysical analysis. The magnetic data depict a nearly 200-km-in-diameter circular anomaly that would correspond to a dense body according to the Bouguer anomaly. Geoid data from the Gravity Field Model (EIGEN-6c4) have been filtered in order to isolate deeper mass influences and visualize the asthenospheric upwelling previously described from magnetotelluric data. Moho inversion yields a crustal attenuation at 36- to 32-km depth coinciding with T e below 20-km depth and a shallow T c (≤15-km depth) at the site where Geoid positive undulation was calculated. Finally, surface analysis allowed defining a topographic swell, compatible with the dimensions of the identified magnetic anomaly, where the main rivers deviated, potentially due to a recent base level change.Fil: Astort, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Colavitto, Bruno. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Sagripanti, Lucía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Garcia, Hector Pedro Antonio. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Geofísico Sismológico Volponi; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Echaurren Gonzalez, Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Soler, Santiago Rubén. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Geofísico Sismológico Volponi; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Ruíz, F.. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Geofísico Sismológico Volponi; ArgentinaFil: Folguera Telichevsky, Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentin

GPS Tracking of Free-Ranging Pigs to Evaluate Ring Strategies for the Control of Cysticercosis/Taeniasis in Peru

Background Taenia solium, a parasitic cestode that affects humans and pigs, is the leading cause of preventable epilepsy in the developing world. T. solium eggs are released into the environment through the stool of humans infected with an adult intestinal tapeworm (a condition called taeniasis), and cause cysticercosis when ingested by pigs or other humans. A control strategy to intervene within high-risk foci in endemic communities has been proposed as an alternative to mass antihelminthic treatment. In this ring strategy, antihelminthic treatment is targeted to humans and pigs residing within a 100 meter radius of a pig heavily-infected with cysticercosis. Our aim was to describe the roaming ranges of pigs in this region, and to evaluate whether the 100 meter radius rings encompass areas where risk factors for T. solium transmission, such as open human defecation and dense pig activity, are concentrated. Methodology/Principal Findings In this study, we used Global Positioning System (GPS) devices to track pig roaming ranges in two rural villages of northern Peru. We selected 41 pigs from two villages to participate in a 48-hour tracking period. Additionally, we surveyed all households to record the locations of open human defecation areas. We found that pigs spent a median of 82.8% (IQR: 73.5, 94.4) of their time roaming within 100 meters of their homes. The size of home ranges varied significantly by pig age, and 93% of the total time spent interacting with open human defecation areas occurred within 100 meters of pig residences. Conclusions/Significance These results indicate that 100 meter radius rings around heavily-infected pigs adequately capture the average pig’s roaming area (i.e., home range) and represent an area where the great majority of exposure to human feces occurs

Factores domiciliarios asociados con la presencia de hidatidosis humana en tres comunidades rurales de Junín, Perú

Introduction. Hydatid disease, a zoonosis caused by the larval stage of the parasite Echinococcus granulosus, is a public health problem at national level, especially in those regions dedicated to raising livestock. By now, there are many factors, at individual level, that have been associated to the infection by E. granulosus; nevertheless there is not any previous report that explore the association between household characteristics and the presence of the disease among household members. Objective. To explore the association between household characteristics and the presence of hydatid disease among household members. Material and methods. We performed a cross-sectional study in the households of 3 rural communities located in Junín, we evaluated the association between household characteristics and the presence of hydatid disease by multiple logistic regression (MLR). Results. from 417 evaluated households, 56 (13%) of them had at least one positive case among its members. Multivariate analysis showed that households with three or more members, located in the community with the lowest quintile of poverty, that reported raising livestock, and with evaluation coverage greater than 25% were more likely to have at least one positive case among its members. Conclusion. The observed characteristics be taken into account in the preliminary definition of high-risk subgroups, optimizing the use of resources and improving the effectiveness of screening programs. Introducción. La hidatidosis, zoonosis producida por el estadio larvario de la taenia Echinococcus granulosus, es un problema de salud pública a nivel nacional, en especial en aquellas regiones dedicadas a la crianza de ganado. A la fecha, se han descrito factores, a nivel individual, asociados con la infección por E. granulosus; sin embargo, no se encontró reporte previo que explore la asociación entre características de la vivienda y la presencia de esta enfermedad en alguno de sus miembros. Objetivos. Explorar la asociación entre las características de la vivienda y la presencia de hidatidosis entre las personas que la habitan. Materiales y métodos. Se realizó un estudio transversal en viviendas de tres comunidades rurales de Junín. Se evaluó el grado de asociación entre las características de la vivienda y la presencia de hidatidosis en el hogar mediante un análisis de regresión logística múltiple (RLM). Resultados. De un total de 417 viviendas evaluadas, 56 (13%) de ellas tenían al menos un caso positivo entre sus miembros; luego del análisis de RLM se observó que aquellas viviendas con más de tres miembros, localizadas en la comunidad con quintil de pobreza más bajo, que refirieron crianza de animales, y con una cobertura de evaluación mayor al 25% presentaron una mayor probabilidad de tener al menos un caso de positivo entre sus miembros. Conclusión. Las características observadas deben ser tomadas en cuenta para la determinación preliminar de subgrupos de alto riesgo, optimizando así el uso de los recursos y mejorando la eficacia de los programas de despistaje