Las salidas didácticas al entorno más próximo: visita al Ayuntamiento

En el presente trabajo fin de grado se argumenta la necesidad de realizar salidas didácticas al entorno próximo al centro educativo, como fuente de información, documentación y recurso pedagógico, así como experiencias directas que aportan prácticas, que nos ayudan a entender los marcos teóricos y conceptuales que se trabajan en el aula. A su vez, desarrollamos una visita al entorno del colegio, el ayuntamiento del municipio, como trabajo de campo para el desarrollo de la actividad sobre el municipalismo, el gobierno local y la participación ciudadana en el hecho democrático, tan necesario en nuestro organigrama estatal.Grado en Educación Primari

Universidad y feminización: la experiencia cubana

A lo largo de los últimos sesenta años la educación superior cubana ha mostrado variaciones importantes de su matrícula general dependiendo de las políticas de acceso puestas en vigor en diferentes momentos. Sin embargo, hasta el curso 2006-2007 se mantuvo un incremento sostenido de la proporción de mujeres en las aulas universitarias, lo que dio lugar a igual comportamiento del índice de paridad de género, aunque a partir del mencionado año académico se invirtió la tendencia del indicador hasta alcanzar un valor mínimo en el 2014-2015. El trabajo realiza una revisión analítica de datos de matrícula, tanto totales como desagregados por ramas del conocimiento, con el propósito de identificar las causas que determinaron la disminución de la feminización de la matrícula universitaria entre los cursos 2006-2007 y 2014-2015, así como su recuperación en los cursos posteriores. Se concluye que tales variaciones en el acceso de las mujeres se explican esencialmente a partir de cambios que tuvieron lugar en las políticas de ingreso desde finales de la primera década del 2000. El estudio también aborda la diferenciación por sexo de las carreras universitarias, donde se aprecia claramente una menor incorporación de las mujeres en los programas de estudio relacionados con las Ciencias, Tecnologías, Ingenierías y Matemática (CTIM), a pesar de su reconocida importancia en la necesaria diversificación de profesiones y empleos directamente relacionados con el desarrollo económico y social. Adicionalmente se proponen tareas de investigación para continuar profundizando en estas problemáticas.In the past sixty years, Cuban higher education has shown significant variations in its general enrollment rates depending on the application of different access policies. However, the proportion of women attending higher-education institutions kept a sustained increase until the academic year 2006-2007, with the same behavior of the gender parity index. Nevertheless, from the aforementioned academic year, this trend was reversed until reaching a minimum value in 2014-2015. The article analyzes enrollment data, both total and disaggregated by branches of knowledge, to evaluate the causes that led to the decrease of feminization in the enrollment rates between the academic years 2006- 2007 and 2014-2015 and to the recovery of women’s representation in the periods that followed. It concludes that such variations in women’s access are primarily explained by changes that started to take place in the admission policies by the end of the first decade of the twenty-first century. The study also discusses sex differentiation between majors, remarking the low incorporation of women to the Science, Technology, Engineering and Mathematics (STEM) fields despite the significance of these branches in the diversification of professions directly related to socio-economic development. Additionally, the article proposes research tasks to deepen the understanding of these problems

Phase stability and structural temperature dependence in sodium niobate: A high resolution powder neutron diffraction study

We report investigation of structural phase transitions in technologically important material sodium niobate as a function of temperature on heating over 300-1075 K. Our high resolution powder neutron diffraction data show variety of structural phase transitions ranging from non-polar antiferrodistortive to ferroelectric and antiferroelectric in nature. Discontinuous jump in lattice parameters is found only at 633 K that indicates that the transition of orthorhombic antiferroelectric P (space group Pbcm) to R (space group Pbnm) phase is first order in nature, while other successive phase transitions are of second order. New superlattice reflections appear at 680 K (R phase) and 770 K (S phase) that could be indexed using an intermediate long-period modulated orthorhombic structure whose lattice parameter along direction is 3 and 6 times that of the CaTiO3-like Pbnm structure respectively. The correlation of superlattice reflections with the phonon instability is discussed. The critical exponent ({\beta}) for the second order tetragonal to cubic phase transition at 950 K, corresponds to a value {\beta}$\approx 1/3$, as obtained from the temperature variation of order parameters (tilt angle and intensity of superlattice reflections). It is argued that this exponent is due to a second order phase transition close to a tricritical point. Based on our detailed temperature dependent neutron diffraction studies, the phase diagram of sodium niobate is presented that resolves existing ambiguities in the literature.Comment: 21 Pages, 8 Figure

A new method for preparing nanometer-size perovskitic catalysts for CH4 flameless combustion

A novel method based on flame hydrolysis of aqueous solutions of precursors has been set up for preparing perovskite-type mixed oxide catalysts in nanometer size particles of high surface area and high thermal stability. After optimising the shape and size of the various parts of the equipment and all the operational parameters, the method has been applied to the preparation of a series of samples of general formula La1-xMxCoO3+\u3b4, with x = 0, 0.1 and M = Ce, Eu. Perfectly crystalline powders, made of 200-600 \uc5 microspherical particles, generally clustered into 100-500 nm conglomerates, with SBET typically of 20-30 m2/g, were obtained. The catalysts proved highly thermally resistant and up to one order of magnitude more active than samples of identical composition, but prepared through traditional methods, allowing to attain 100% methane conversion at temperature as low as 560\ub0C

The Freundlich model of adsorption for calculation of specific surface areaS

The specific surface area of solids and the surface area occupied by the active phase (metal or oxide) on a support are parameters of the utmost importance in adsorption and catalysis. For the determination of the former, the BET equation is universally established. For the evaluation of the latter the works of selective chemisorption, initiated by Emmett and Brunauer (I ), for metals and by Bridges et al. (2) and Weller et al. (3), for oxides have come to represent important contributions. Some of the classical models of adsorption have also been used for evaluation of specific surfaces (Langmuir equation) (4) and the dispersion of supported metals or oxides (Freundlich equation) (5). Both of them are applicable to physisorption as well as chemisorption processes

Structured Perovskite-Based Catalysts and Their Application as Three-Way Catalytic Converters—A Review

Automotive Three-Way Catalysts (TWC) were introduced more than 40 years ago. Despite that, the development of a sustainable TWC still remains a critical research topic owing to the increasingly stringent emission regulations together with the price and scarcity of precious metals. Among other material classes, perovskite-type oxides are known to be valuable alternatives to conventionally used TWC compositions and have demonstrated to be suitable for a wide range of automotive applications, ranging from TWC to Diesel Oxidation Catalysts (DOC), from NOx Storage Reduction catalysts (NSR) to soot combustion catalysts. The interest in these catalysts has been revitalized in the past ten years by the introduction of the concept of catalyst regenerability of perovskite-based TWC, which is in principle well applicable to other catalytic processes as well, and by the possibility to reduce the amounts of critical elements, such as precious metals without seriously lowering the catalytic performance. The aim of this review is to show that perovskite-type oxides have the potential to fulfil the requirements (high activity, stability, and possibility to be included into structured catalysts) for implementation in TWC

CO oxidation on perovskite-type LaCoO3 synthesized using ethylene glycol and citric acid

In order to synthesize perovskite-type LaCoO3 with good surface crystallinity, the gel prepared by adding both ethylene glycol (EG) and citric acid (CA) to the aqueous solution of La(NO3)3 center dot 6H(2)O and Co(NO3)(2) center dot 6H(2)O was fired at 600 degrees C in air for 3 h. The transmission electron microscopy (TEM) observation indicated that the particles of LaCoO3 tended to have a uniform shape at EG/CA = 4. Although, the specific surface area of LaCoO3 synthesized using both EG and CA was slightly smaller than that of LaCoO3 synthesized using only CA, the catalytic activity of CO oxidation became higher by adding EG

¿La cirugia bariatrica mejora sensiblemente la calidad de vida del paciente?

Objective: The aim of this investigation was to assess the effect of malabsorptive bariatric surgery (BS) on the quality of life (QoL), applying the Nottingham Health Profile (NHP) and the bariatric analysis and reporting outcome system (BAROS). Design: A prospective cohort study was performed in 100 adult patients (> 18 years) undergoing bariatric surgery by malabsorptive technique for one year. Research methods and procedures: Patients were monitored from the beginning of the BS program until a year after the intervention, applying the NHP and the BAROS test. At baseline, the mean weight of the women was 132 ± 22 kg and the Body Mass Index (BMI) was 50.7 kg/m2. Results: The values obtained from different areas applying the NHP questionnaire showed statistical significant differences (p < 0.001) with respect to baseline values. According to the BAROS test, 48% of patients lost 25-49% of weight excess and 80.8% had resolved major comorbidities at 1 yr. According to the Moorehead-Ardelt QoL score, there were major improvements in employment and self-esteem in 89% and 87% of patients, respectively, and improvements in physical activity, sexual and social relationships. According to the total mean BAROS score, the outcome was considered “very good”. Conclusion: NHP and BAROS questionnaires appear to be useful and easily applicable tools to assess the QoL of obese patients.Introducción: La obesidad mórbida suele acompañarse de enfermedades graves asociadas que provocan una menor expectativa y peor calidad de vida (CV). Objetivos: evaluar el efecto de la cirugía bariátrica (CB) por técnicas malabsortivas sobre la CV, utilizado (Perfil de Salud del Nottingham (PSN) y el Bariatric analysis and reporting outcome system (BAROS). Material y métodos: Estudio prospectivo, descriptivo, desde Octubre del 2002 hasta Mayo de 2006, seguimiento a los pacientes desde el inicio al protocolo de CB hasta el año post-intervención., donde se incluyeron 100 pacientes. El 86% mujeres, el peso inicial medio 132±22 kg y IMC de 50,7 kg/m2. Se aplicaron 2 cuestionarios: PSN y el BAROS. Resultado: Los valores obtenidos de las diferentes áreas aplicando el cuestionario PSN al año de la intervención muestran diferencias estadísticamente significativas (p < 0,001) con los valores iniciales. Según BAROS: Porcentaje de sobrepeso perdido (%SP). El 48% de los pacientes perdió entre el 25 y el 49% de su exceso de peso. Condiciones médicas. El 80,8% habían resuelto todas las comorbilidades mayores. CV de Moorehead Ardelt. El aspecto más mejorado fue el empleo el 89% , autoestima solo el 13% no presentó cambios, las áreas de la actividad física, relaciones sexuales y sociales fueron consideradas como mucho mejor. Basándonos en esta clasificación nuestros resultados se pueden calificar de “muy buenos”. Conclusión: Los cuestionarios PSN y BAROS parecen ser herramientas útiles y de fácil aplicación para evaluar la calidad de vida de los pacientes obesos

Aprender jugando: aplicación de juegos interactivos para el aprendizaje de la Química en Ciencias Farmacéuticas

Aplicación de la dinámica de los juegos interactivos en las prácticas de Química Orgánica del Grado en Farmacia mediante la utilización de nuevas tecnologías y herramientas on line