Proyectos

Desarrollo de habilidades de lenguaje y matemáticas en niños con diagnóstico de TEL de estudiantes de primer año básico en la región de O'Higgins

Dislocations are at the source of plastic behavior of metals and alloys, yet it is very difficult to quantitatively study their behavior. In order to improve this situation, it is proposed to use their interaction with elastic waves as a nonintrusive probe. The long-term aim of the research presented in this proposal is to enable the development of ultrasound technology as a practical non-intrusive tool for the characterization of plastic behavior of materials. In recent years, proposers have shown, using Resonant Ultrasound Spectroscopy (RUS), that an increase of dislocation density in aluminum by a factor of 6 leads to a change for the speed of shear waves on the order of 1%, a quantity that can be measured with an accuracy on the order of 0.1%. They have also shown that local measurements of the speed of shear waves in aluminum under standard testing conditions in tension provide a quantitative, accurate, nonintrusive and continuous relation between dislocation density and externally applied stress, and that an increase in dislocation density by a factor of ten in copper and aluminum leads to an increase in the value of the (nonlinear) parameter that characterizes second harmonic generation by 20 to 60%. This proposal seeks to go one more step towards a practical implementation of the proposed ultrasonic testing tool for pieces in service. Materials of wide use in industry, 304L steel and TWIP steel, will be used. And in addition to bulk ultrasonic and shear waves, surface Rayleigh waves will be tested, in order to develop techniques that are useful when pieces in service have a geometry that does not lend itself to bulk wave measurement. Both linear (wave propagation velocity and attenuation) and nonlinear (second harmonic generation) acoustics measurements will be performed, using bulk and surface waves, ex situ after mechanical treatment, and in situ under standard testing conditions. In addition, dislocation density will be measured using X-ray diffraction (XRD) , using both the modified Warren-Averbach and Rietveld methods. Additional characterization will be performed using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The expected result of the proposed research is a set of measurements that relate acoustics parameters to dislocation density in 304L and TWIP steels. The specific goal is that these measurements will provide a framework for the development of devices to nondestructively measure the dislocation density of pieces in service.

This research project has as its overarching question, the following: To what extent have political contexts shaped the evolution of sustainable development praxis? Rather than sustainable development being a single, universal paradigm that has been uniform in its conceptual progression, its integration into public policy, and in public and private practice, the argument that will be explored in this project is that sustainable development is a hybrid conceptual form that has been adapted by different institutions and organizations to fit within specific dominant political frameworks. The hypothesis that guides the research is as follows: Sustainable development, from its emergence at the Stockholm Conference in 1972, has been coopted and adapted by different institutions and organizations to specific, dominant political frameworks, and is therefore a hybrid socio-ecological paradigm that exhibits considerable contextual diversity rather than as a singular global narrative. Since the Stockholm Declaration of 1972 which set in motion the agendas around sustainable development and subsequent Summits, leading to the current Agenda 2030, there has been a political struggle to define its conceptual underpinnings and the nature of this evolving socio-ecological paradigm. Considerable research has been undertaken on sustainability issues, and the concept has been brought firmly into public policy considerations. However, most of this work is apolitical, in that – as a normative concept – it promotes desirable processes and outcomes, but fails to consider the political frameworks in which sustainable development is situated. The proposed research project seeks to repoliticize the debate around the sustainable development paradigm and understand the different geographies of promotion and diffusion that have taken place since 1972, focusing on the political frameworks that have shaped its incorporation. During the period 1972-2022 (to the next Sustainable Development Summit, Rio+30), the international development context has been defined by ideological positions of capitalism, communism, socialism, neoliberalism, neostructuralism, social democracy and populism, which are themselves often hybridized and heterodox. These ideologies are rarely discussed with reference to sustainable development. The proposed research will analyze the evolution of the paradigm as a political construct at three scales: global, regional (Latin America) and Chile. The three principal objectives are to: 1. Analyze the relationship between political theory and frameworks and the evolution of the sustainable development paradigms at different scales; 2. Examine the factors that shape homogeneity and heterogeneity in the integration of the paradigm in different contexts; 3. Explain the ways in which sustainable development has been coopted and adapted by different political positions, and the relevance of this for understanding sustainable development praxis within the context of Agenda 2030. The methodology is mixed, interpretivist and post-structural. It involves three methods: the analysis of sustainable development theory and political theory in order to develop a conceptual framework for examining the nexus of politics and sustainable development; the analysis of the translation of this nexus into public and practice through the revision of secondary materials and ‘grey’ sources (e.g. policy agendas and related documents, declarations), involving content analysis and discourse analysis; interviews with key informants to understand perceptions of the paradigm and its politicization in Chile. The expected results will contribute to the critical analysis of the paradigm of sustainable development, its strengths and weaknesses in specific contexts, and a more nuanced appreciation of how Agenda 2030 and the Sustainable Development Goals will be pursued over the coming decade, in Chile and Latin America more widely. In terms of its contribution to knowledge, it will complement work in the fields of political geography, political ecology and historical geography.

El Objetivo del proyecto es mitigar impacto económico mediante difusión y capacitaciones taxonómicas y visuales enfocadas a pequeños productores, logrando un plan de manejo integrado de la plaga.

El Objetivo del proyecto es mitigar impacto económico mediante difusión y capacitaciones taxonómicas y visuales enfocadas a pequeños productores, logrando un plan de manejo integrado de la plaga.

El tetrahidrocannabinol (THC) es el principal compuesto activo de la Cannabis, siendo el causante de los efectos estupefacientes de la droga. Esta droga se considera una de las drogas de abuso más prevalentes en la población, se estima que casi un 5% de los adultos en el planeta consumen cannabis, con países como Estados Unidos con un consumo de más del 12% de los adultos. En la actualidad el uso recreacional y medicinal de la cannabis esta en alza y se espera su consumo continúe aumentando, sobretodo en jóvenes. La primera administración de THC causa múltiples efectos en el organismo. Por ejemplo, una dosis de THC puede causar analgesia, ataxia (descoordinación motora), inhibición motora, actividad anticonvulsionante, hipotermia, inmovilidad, incremento en el apetito, euforia seguida de sedación, dificultades en la memoria, entre otros efectos. Sin embargo, estos efectos disminuyen tras la administración crónica por semanas y meses de la droga, tanto en estudios con humanos como con animales de laboratorio, demostrando así el desarrollo de tolerancia a ciertos efectos del THC. Desde una análisis Pavloviano de la tolerancia a las drogas, los estímulos, contextos y situaciones presentes al momento de la administración de una droga funcionan como estímulos condicionados, y los efectos de la droga en el sistema nervioso como estímulos incondicionados. Así, cuando los efectos de la administración de una droga perturban la homeostasis del organismo, este responde con respuestas incondicionadas opuestas que compensan los efectos de la droga, ayudando así a restablecer la homeostasis. Dado que la evaluación de la tolerancia a los efectos del THC no ha sido explorada desde esta perspectiva asociativa, a pesar de ser un modelo que bien explica la tolerancia a otras drogas como la morfina y el etanol, en el presente proyecto proponemos evaluar los efectos agudos, la tolerancia, y la especificidad contextual de la tolerancia al THC. Además, considerando la importancia del desarrollo durante la gestación y la lactancia, evaluaremos los efecto de la administración de THC en estas etapas, tanto en el desarrollo de tolerancia como en posibles efectos detrimentales en la memoria y el aprendizaje. Considerando lo anterior, en el presente proyecto proponemos evaluar los efectos agudos, la tolerancia, y la especificidad contextual de la tolerancia al THC en ratas Sprague Dawley. Así, la Serie experimental 1 evaluará los efectos del THC en la coordinación motora (utilizando una Rueda caminadora), la 2 evaluará los efectos del THC en la locomoción (utilizando un Campo abierto), y la 3 evaluará los efectos del THC en la memoria (utilizando una Laberinto radial), todo esto en ratas a cuyas madres se les administró THC durante la gestación y la lactancia y a ratas cuyas madres no han recibido THC. La Serie experimental 4 evaluará el aprendizaje y la memoria en ratas a cuyas madres se les administró THC durante la gestación y la lactancia (utilizando un Laberinto radial y cajas de condicionamiento). En específico, los Experimento 1.1, 2.1, y 3.1 evalúan diariamente a los sujetos por 30 días en su coordinación motora, locomoción, y memoria, respectivamente, antes y después de una administración de THC. Adicionalmente los sujetos serán evaluados de igual forma en el contexto regular de administración y en un nuevo contexto, para determinar así la situacionalidad de la tolerancia. Los Experimentos 1.2, 2.2, y 3.2 siguen los mismos procedimientos, pero se realizarán en tres grupos de ratas, ratas a cuyas madres de les administró THC durante la gestación y la lactancia y ratas descendientes de madres sin experiencia con el THC. En los Experimento 4.1, 4.2, y 4.3 tres grupos de ratas serán evaluadas en su capacidad para adquirir una asociación Pavloviana, una operante, y en una tare de memoria, respectivamente. Se utilizarán ratas a cuyas madres de les administró THC durante la gestación y la lactancia y ratas descendientes de madres sin experiencia con el THC. Se espera que la administración aguda de THC tendrá un efecto detrimental en la coordinación motora, la locomoción, y la memoria, que los sujetos desarrollarán tolerancia a los efectos del THC luego de múltiples administraciones, y que esta tolerancia será especifica al contexto de administración. Además, se espera que la administración de THC durante la gestación y el embarazo tenga un efecto detrimental en la coordinación motora, la locomoción, y la memoria, que acelere el desarrollo de la tolerancia sin necesariamente afectar la situacionalidad de la tolerancia. Finalmente, se espera que la administración de THC durante la gestación y el embarazo tenga un efecto detrimental en el aprendizaje de tareas de condicionamiento Pavloviano apetitivo, de condicionamiento operante apetitivo, y de memoria.

Work on the open problem of proving existence of minimizers in nonlinear elasticity in the paradigmatic neoHookean model. Finite element simulations, modelling, and experiments for swelling of polymer gels bonded to rigid substrates. Finite element simulations, modelling, and asymptotic analysis for Schallamach waves in the detachment of thin hydrogels. Proof that the transition, in elastomers and ductile materials, from multiple independent spherical cavitation to the coalescence stage occurs when the size, in the deformed configuration, of the opened cavities is comparable to the distance, in the reference configuration, between the cavitation singularities.