Preparación de una práctica de laboratorio de física: "Electroquímica: Galvani, Volta o el pez Torpedo"

El presente trabajo fin de master versa sobre el diseño y desarrollo de una práctica de laboratorio asociada a la asignatura de Física 2º Bachillerato. El objetivo final de este trabajo fin de master es enfatizar en la importancia de profundizar en los conocimientos científicos básicos a través de la experimentación, en el marco de un aprendizaje significativo que plantea que se aprende mejor aquello que se hace por uno mismo. La adquisición de un conocimiento científico básico es esencial para fomentar la creatividad del alumno frente a problemas futuros. Las experiencias aquí propuestas giran en torno a la construcción de la pila electroquímica de Volta. La elección de esta temática se justifica en su capacidad para ilustrar la importancia de la relación entre la curiosidad científica por resolver un problema (origen de la electricidad en el pez torpedo) y el desarrollo tecnológico (construcción de la pila electroquímica).Electricidad y ElectrónicaMáster en Profesor de Educación Secundaria Obligatoria y Bachillerato, Formación Profesional y Enseñanzas de Idioma

Impact of maternal dietary supplementation in the prevention of neuropediatric diseases

Motivation: A balanced maternal diet during pregnancy is crucial for the proper development of the embryo. In this project, we will study the impact of maternal dietary supplementation in the prevention of the development of neonatal strokes and neural tube defects (NTDs) using two mouse models.1. Neonatal stroke is a pathology with a heterogeneous etiology, leading to important sequelae. Currently, hypothermia is the only clinical intervention used in full-term newborns with perinatal asphyxia. However, the influence of diet has recently begun to be considered relevant in reducing brain damage in possible future injuries. Thus, maternal diet supplementation with omega-3 fatty acids as a tool for neuroprotection has been proposed. In order to test this, we will start with the development of a neonatal mouse model of hypoxia-ischemia (HI) and characterize the type and severity of brain injury.2. Neurulation refers to the neural tube formation process. When neural tube fails to close completely, NTDs are originated, including craniorachischisis or spina bifida. While 70% of NTDs can be prevented with folic acid supplementation during pregnancy, the rest remains resistant. Loop-tail mouse is a folic acid resistant model of NTDs who carries a mutation for the Vangl2 gene (which is involved in the Wnt-PCP pathway). Previous studies have shown that inositol prevents NTDs in folate-resistant models. Preliminary studies of our group have suggested that maternal supplementation with D-chiro-inositol during embryonic days (E)8.5-E10.5 has a positive effect on the dorsal fusion of the neural folds and on the distribution of actin present in these. Therefore, we propose to extend the period of supplementation (E1.5-E11.5) to determine whether such effect is more pronounced.Methods: We used the Rice-Vannucci model of HI modified to postnatal day (P)8 CD1 mice. Pups were subjected to unilateral left carotid artery ligation and subsequently exposed to 9% O2 for 45’. Infarct size measurement was done 24h post HI, evaluation of brain damage was done 3 days post-HI and behavioural outcomes were assessed at P8, P9 and P12. To assess the impact of maternal dietary supplementation in the prevention of NTD we provided water supplemeted with D-chiro-inositol to pregnant mice Vangl2+/Lp from E1.5 to E11.5. Embryos were obtained and genotyped at E12.5 for later phenotype analysis. In addition, in situ hybridization studies and fluorescent phalloidin stainings were performe

Preparación de una práctica de laboratorio de Física : Electroquímica : Galvani, Volta o el pez Torpedo

Resumen basado en el de la publicaciónResumen también en inglésMáster en profesor de Educación Secundaria Obligatoria y Bachillerato, Formación Profesional y Enseñanzas de IdiomasSe presenta el diseño y desarrollo de una práctica de laboratorio asociada a la asignatura de Física de 2º Bachillerato. Se persigue enfatizar en la importancia de profundizar en los conocimientos científicos básicos a través de la experimentación, en el marco de un aprendizaje significativo que plantea que se aprende mejor aquello que se hace por uno mismo. La adquisición de un conocimiento científico básico es esencial para fomentar la creatividad del alumno frente a problemas futuros. Las experiencias aquí propuestas giran en torno a la construcción de la pila electroquímica de Volta. La elección de esta temática se justifica en su capacidad para ilustrar la importancia de la relación entre la curiosidad científica por resolver un problema (origen de la electricidad en el pez torpedo) y el desarrollo tecnológico (construcción de la pila electroquímica).Castilla y LeónES

Structural dependence of grain boundary energy in Fe-based polycrystals identified by OIM measurements

The (relative) grain boundary energy of random high angle boundaries has been measured in several Fe-based polycrystals. Crystallographic data obtained by orientation contrast microscopy (OIM) are combined with the geometrical configuration of grain boundaries at triple junctions. A two-parameter representation of the relative grain boundary energy in terms of misorientation angle and misorientation axis is presented. In the applied procedure a variation of the energy values assigned to one boundary was observed depending on the triangulation path chosen by the operator to connect the arbitrary initial boundary with the boundary under consideration. Results show no evidence of correspondence between the observed energy cusps and the presence of CSL boundaries

Correlation between boundary energy and grain boundary character distribution in Fe-based polycrystals

The grain boundary energy anisotropy in BCC Fe-based polycrystals is considered. The correlation between the energy in BCC random grain boundaries and the distribution of grain boundary planes in the bulk was examined with a special attention on the presence of low index (low surface energy) planes in the internal surfaces. For a BCC structure, {100} and {110} planes are known to be the lowest energy planes dominating the equilibrium crystal shapes. Experimental evidences demonstrated that these planes were predominant in the texture of surfaces controlled by surface energy [2]. Moreover, the relation between the grain boundary character distribution and the crystal lographic dependence on the grain boundary energy in the bulk after annealing treatment was studied. The grain character boundary distribution (GCBD) was calculated using the crystallographic information obtained from OIM-EBSD maps from samples showing columnar grains. Preliminary results showed no particular distribution trend within the standard stereographic triangle (001-101-111)

Texture control in non-oriented electrical steels by severe plastic deformation

Although plenty of research has already been carried out on the issue of texture control in non-oriented electrical steels, there is not yet a universally applied industrial process to obtain an optimized {001} fibre texture. Among the various laboratory processes that have been studied so far, cross rolling seems to be one of the most promising approaches. For evident reasons cross-rolling cannot be implemented on a conventional continuous rolling line of an industrial plant. In the present study a potential interesting alternative is presented which may deliver a similar texture evolution as the cross rolling process, but can be applied in a continuous line of hot and cold rolling operations followed by recrystallization annealing. By applying severe rolling reductions a very strong rotated cube texture is obtained very much similar to the one that is observed after cross rolling. After annealing, the rotated cube texture changes to a {h11} fibre texture with a maximum on the {311} component which implies the potential to develop a {001} fibre texture after further processing. It is argued that the appearance of the {311} recrystallization texture component can be attributed to oriented nucleation in the vicinity of grain boundaries between slightly misoriented rotated cube grains

Origin of the {h 1 1}<1/h,1,2> fiber in single phase ferrite steels

In the present work, the oriented nucleation origin of the recrystallized {h11} fibre is characterized. Aiming to investigate the substructural evolution of 1/RD fibre grains and {001} grains in particular, a detailed microstructure and texture analysis is performed by high resolution orientation scanning microscopy on a cross-rolled sample. The reason to work with cross-rolled material is the increased incidence of rotated cube orientations after cross rolling. The present data have revealed the presence in the deformed substructure of a crystallite volume that has rotated towards the {311} component in the interior of //RD fibre grains as a result of a grain fragmentation process. Preliminary simulations of the deformation texture suggested that the observed orientation fragmentation might be produced by strain localizations of a shear band nature