7,057 research outputs found
Manteniendo viva la memoria ancestral. María Inés Huenuñir Antihuala. Más allá de ser mapuche. Autoedición en HS Imprenta, Santiago, 2008
La 2ª edición de Más allá de ser mapuche es un hecho que hay que celebrar. Este poemario, cuyo primer tiraje fue en 2004, nos invita a pensar sobre las cosas simples, tal como reza su tapa. Contactarnos con la tierra para sentir su clamor y conocer el sentimiento de una madre mapuche criada en el campo y extranjera en la urbe, parecieran ser los dos objetivos principales que se esconden tras el texto
Transformational Learning Experiences Among Latinas Who Have Attained A Tenure Status in Academia
This qualitative research investigation was designed to understand the transformational learning experiences among Latinas in academia and how these experiences affect their academic experience and teaching styles. Specifically, the following research questions were addressed: (1) How do Latinas that reach a tenure status interpret their journey and experiences within academia? (2) How do they describe organizational culture in which they work and teach? (3) What types of leadership skills do they possess? (4) How do they describe their experiences in relation to their larger community? Latina women that have reached a tenure status are extremely committed to improving the plight of the marginalized, are dedicated to changing the organization, encourage diversity, and promote social change. Despite the challenging journey through academia, the Latina women displayed a resilient attitude, and described the process as truly transformative. Their experiences provided them with skills to subvert sub-oppressive tactics and to challenge the system to instill fair and equitable educational practices. Negative perceptions of women of color in academia continue to prevail and universities continue to reify socially constructed race and gender theories. Diversity programs have a large impact on student outcomes and success but are subject to budget cuts. A review of the admissions criteria and the long-term impact and benefit of diversity programs are recommended, as well as an analysis of the relationships among academic leaders and the impact on educational policy
Sinterabilidad de aceros de baja aleación modificados con adiciones de aleación maestra de Mn-Si
Sintered steels allow obtaining large batches of high precision parts at a low cost. In order to obtain the required mechanical properties, alloying elements are added. In traditional powder metallurgy, nickel, molybdenum, copper and phosphorous were used. However, because of fluctuations and increase of their price in the last decade, they must be substituted by others, and the current tendency is the study of incorporation of alloying elements, such as manganese and silicon, that maintain, or even improve, mechanical properties and reduce the price of the final component.
In this project, the possibility of adding manganese and silicon to low alloy sintered steels is analyzed and they are introduced in the form of a master alloy. It consists on a powder with high concentration of alloying elements that is mixed with the base powder. This alloying technique can be used to promote the formation of a liquid phase during sintering, which activates the diffusion mechanisms, and allows adjusting the composition in order to obtain the desired microstructure and the required mechanical properties. Moreover, master alloy additions make easier the introduction of alloying elements with high affinity for oxygen (such as Mn and Si) because their chemical activity is reduced when they are alloyed with other elements with low affinity for oxygen.
Along this project, sinterability studies are developed in order to obtain optimum conditions of sintering, as well as the analysis of the alloying effects in order to obtain steels with required microstructure so they can meet a certain requirement. For this purpose, it is very important to analyze the interaction with the sintering atmosphere, due to presence of elements with high affinity for oxygen. Therefore, three different steels are sintered in two different atmospheres: argon and hydrogen. The alloying effect and the interaction with the atmosphere are evaluated through several tests, such as degasification studies, chemical analysis, density and dimensional variation, metallography and fractography. _______________________Los aceros sinterizados permiten la obtención de grandes lotes de piezas con gran precisión geométrica, con un coste bajo. Para obtener las propiedades mecánicas requeridas, es preciso añadir elementos de aleación. En pulvimetalurgia convencional, se usaban como aleantes níquel, molibdeno, cobre y fósforo. Sin embargo, debido a la fluctuación y el alza de precios en la última década, es necesario sustituir estos elementos de aleación por otros. La tendencia actual consiste en estudiar la incorporación de aleantes, como manganeso y silicio, que mantengan las propiedades mecánicas, o incluso las mejoren, y reduzcan el precio del componente final.
En este proyecto, se analiza la posibilidad de añadir manganeso y silicio en aceros sinterizados de baja aleación, mediante la adición en forma de aleación maestra. Ésta consiste en un polvo con alta concentración de elementos de aleación, que es mezclada con el polvo base. Esta técnica se puede emplear para promover la formación de una fase líquida, la cual activa la sinterización, y también permite la posibilidad de ajustar la composición para obtener una determinada microestructura y las propiedades requeridas. Además, la adición de una aleación maestra facilita la introducción de aleantes con elevada afinidad por el oxígeno (como Mn y Si), porque su actividad química se ve reducida al ser añadidos con elementos de baja afinidad.
A lo largo de este proyecto, se realiza un estudio de sinterabilidad para obtener las condiciones óptimas de sinterización, así como el análisis del efecto de los elementos de aleación para obtener aceros sinterizados con una cierta microestructura, que satisfaga los requisitos. Para poder alcanzar el objetivo, es importante analizar la interacción de la atmósfera de sinterización, debido a la presencia de elementos con elevada afinidad por el oxígeno. Por lo tanto, tres aceros distintos son sinterizados en dos atmósferas diferentes: argón e hidrógeno. El efecto de los aleantes y la interacción con la atmósfera se evalúa realizando una seria de pruebas, como son estudios de degasificación, análisis químico, densidad y variación dimensional, metalografía y fractografía.Ingeniería Industria
Estado de las políticas públicas frente al desempleo en jóvenes entre los 18 y los 26 años de edad, con un nivel de estudios superior que habitan en la comuna 16 de Medellín en condiciones de vida favorables
Si bien en la actualidad existen programas del SENA, de la Alcaldía Municipal y de la empresa privada, es evidente la falta de articulación de éstos para estructurar una política pública frente al desempleo. Hay programas e iniciativas dirigidas en esa línea, pero se hace necesaria una política sostenible, que en buena medida logre dar solución a este problema social.
Es además preocupante que gran parte de los jóvenes con acceso a la educación superior desde técnicos hasta profesionales, tienen gran dificultad para vincularse laboralmente y en muchos casos están engrosando las filas del subempleo, situación que no es ajena a los jóvenes de la comuna 16 de Medellín, donde se encuentra concentrada la mayor parte de la población ciudadana y en territorio constituye una porción proporcional a esta condición
Structure-dissolution relationships of phosphate and bioactive glasses by liquid, solid-state and paramagnetic NMR: structural role and coordination environment of cobalt in phosphate glasses & the role of cations on the mechanism of hydrolysis
The doctoral thesis comprises a study of the relationships between structure and dissolution behaviour of phosphate and bioactive glasses by employing analytical techniques such as electron paramagnetic resonance (EPR), liquid NMR, solid-state MAS NMR and paramagnetic NMR spectroscopy, among others. The understanding of the corrosion processes of phosphate glasses is important for their technological applications, e.g. drug delivery, antibacterials and tissue engineering. In the present work, the NMR findings provided insights about the role of cations on the mechanism of hydrolysis of phosphate glasses. The incorporation of cobalt into glasses is a new approach to overcome the vascularization limitation in tissue engineering by stimulating the production of blood vessels. These glasses are also interesting as semiconductors, optical devices and solid-state lasers, among others. This work shows that structural (i.e. thermal) properties of cobalt phosphate glasses with constant basicity are dictated by the coordination number of Co2+ sites. The second part of the study on cobalt phosphate glasses is in publication process under the title: "Co2+ as an internal paramagnetic 31P NMR probe for structural analysis of cobalt-phosphate glasses in the solid-state and leachate solutions". This work presents a new approach to investigate the mechanism of dissolution of phosphate glasses based on the paramagnetic effects. Accordingly, features such as the spin-orbit (SO) coupling, zero-field splitting (ZFS) and symmetry of Co2+ sites are correlated to the paramagnetic shift, paramagnetic relaxation enhancement (PRE) and broadening effects on the spectra. That allows the assessment of the distribution of Co2+ ions in the glass network. Additionally, it enables monitoring structural dynamics of phosphate complexes in solution, including conformational changes, upon ligand binding recognition under different conditions, i.e. buffer aqueous solutions (Tris, EDTA)
Exploring subtropical stratocumulus multiple equilibria using a mixed-layer model
Stratocumulus clouds cover about a fifth of Earths surface, and due to their
albedo and low-latitude location, they have a strong effect on Earths radiation
budget. Previous studies using Large Eddy Simulations have shown that multiple
equilibria (both cloud-covered and cloud-free states) exist as a function of
fixed-SST, with relevance to equatorward advected air masses. Multiple
equilibria have also been found as a function of atmospheric CO2, with a
subtropical SST nearly 10 K higher in the cloud-free state, and with suggested
relevance to warm-climate dynamics. In this study, we use a mixed-layer model
with an added surface energy balance and the ability to simulate both the
cloud-covered and cloud-free states to study both types of multiple equilibria
and the corresponding hysteresis. The model's simplicity and computational
efficiency allow us to explore the mechanisms critical to the stratocumulus
cloud instability and hysteresis as well as isolate key processes that allow
for multiple equilibria via mechanism denial experiments not possible with a
full-complexity model. For the hysteresis in fixed-SST, we find that decoupling
can occur due to either enhanced entrainment warming or a reduction in
cloud-top longwave cooling. The critical SST at which decoupling occurs is
highly sensitive to precipitation and entrainment parameterizations. In the CO2
hysteresis, decoupling occurs in the simple model used even without the
inclusion of an active SST and SST-cloud cover feedbacks, and the width of the
hysteresis displays the same sensitivities as the fixed-SST case. Overall, the
simple model analysis and results motivate further studies using higher
complexity models.Comment: Submitted to Journal of Climate 06-12-202
Caracterización del perfil profesional y la situación ocupacional, laboral y económica del egresado de Licenciatura en Pedagogía Infantil de La Universidad Tecnológica de Pereira
El observatorio de seguimiento y vinculación del egresado de la Universidad Tecnológica de Pereira es un mecanismo de gestión que busca fortalecer las relaciones de la Universidad con los egresados con el fin de evaluar el impacto sobre el medio que tiene cada uno de ellos, es por este motivo que surge la necesidad de realizar un análisis exhaustivo de los egresados de cada uno de los programas de las facultades de la Universidad, por tal motivo fueron seleccionados tres programas de alta, mediana y baja demanda que corresponden a los programas de Ingeniería Industrial, Licenciatura en Pedagogía Infantil y Licenciatura en Música. Para la realización del estudio se tomó un muestra de 122 egresados de una población de 200 personas graduadas desde los años 2000-2008 del programa Licenciatura en Pedagogía Infantil. Para la recolección de la información se aplicó una encuesta diseñada por el Observatorio de Seguimiento y Vinculación del Egresado y avalada por el Ministerio de Educación Nacional, posteriormente se realizó el análisis estadístico a profundidad que está compuesto por un análisis descriptivo de las variables principales, análisis de contingencia que muestra la relación entre las variables, un análisis de correspondencia que determina el tipo de relación que hay entre las categorías de cada variable seguido por un análisis comparativo y por ultimo un ranqueo para competencias y recursos donde los egresados de pedagogía infantil determinan cuales son sus competencias mas fuertes y débiles; también con estos resultados obtenidos en el análisis estadístico se procede a concluir acerca de la caracterización de los egresados de Licenciatura en Pedagogía Infantil.The observatory for the monitoring and entailment of graduates from the college called Universidad Tecnológica de Pereira is management program whose purpose is to seek the strengthening of the relations between the University and graduates with the aim to evaluate the impact over the environment that every one
of them has, it is for that reason that arises the need to perform a comprehensive
analysis of graduates from the careers and faculties of the University, therefore three programs from high, medium and low demand were selected, corresponding to Industrial Engineering, Degree in Pedagogy and Degree in Music. For the realization of the study, it was taken a sample of 122 graduates among a
population of 200 people selected between the years 2000 to 2008 in the program Degree in Pedagogy. It was applied a survey for the collection of the information, such survey was designed by the observatory for the monitoring and entailment of graduates and endorsed by the Ministry of National Education. It was later conducted a comprehensive statiscal analysis that consists of a descriptive
analysis of the main variables, contingency analysis of relation among variables, a
reciprocation analysis of the relation among the categories of each variable
including a comparative analysis and a ranking for competence and resources wherein the graduates in Degree in Pedagogy may determine the strongest and weakest competence. Also with the results in the statistical analysis, it may be concluded the characterization of graduates in the program termed Degree in Pedagogy
Cerinthe gymnandra Gasparr. (Doraginaceae) on Ihe Iberian Peninsula
CARRAscO, Nl. A. >994. Cecínthe gy¡nttand'-a Gasparr. on the Ibetian Península. Bot. Co,nplutensis, ls.- 75-82. Estudiamos Cerinthe gynmandra Gasparr. en la Península Ibérica, presentando en una tabla comparativa las características de las cuatro variedades de la especie. Comentamos además dos táxones descritos sobre materiales españoles: C. gymnandra Gasparr. var. ibetica Caballero y C. major L. var. valentina Pau, incluidos actualmente en C. gvrnnandra Gasparr. var. gymnandra.CARRAscO, Nl. A. >994. Cecínthe gy¡nttand'-a Gasparr. on the Ibetian Península. Bot. Co,nplutensis, ls.- 75-82. Estudiamos Cerinthe gynmandra Gasparr. en la Península Ibérica, presentando en una tabla comparativa las características de las cuatro variedades de la especie. Comentamos además dos táxones descritos sobre materiales españoles: C. gymnandra Gasparr. var. ibetica Caballero y C. major L. var. valentina Pau, incluidos actualmente en C. gvrnnandra Gasparr. var. gymnandra
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