11 research outputs found
Fenton chemistry-based detemplation of an industrially relevant microcrystalline beta zeolite. Optimization and scaling-up studies
A mild template removal of microcrystalline beta zeolite, based on Fenton chemistry, was optimized. Fenton detemplation was studied in terms of applicability conditions window, reaction rate and scale up. TGA and CHN elemental analysis were used to evaluate the detemplation effectiveness, while ICP, XRD, LPHR-Ar physisorption, and 27Al MAS NMR were applied to characterize the structure and texture of the resulting materials. The material properties were compared to calcination. By understanding the interplay of relevant parameters of the Fenton chemistry, the process can be optimized in order to make it industrially attractive for scale-up. The H2O2 utilization can be minimized down to 15 mL H2O2/g (88 °C, 30 ppm Fe), implying a high solid concentration and low consumption of H2O2. When Fe concentration must be minimized, values as low as 5 ppm Fe can be applied (88 °C, 30 mL H2O2/g), to achieve full detemplation. The reaction time to completeness can be reduced to 5 h when combining a Fe-oxalate catalyst with UV radiation. The protocol was scaled up to 100 times larger its original recipe. In terms of the material's properties, the scaled material is structurally comparable to the calcined counterpart (comparable Si/Al and XRD patterns), while it displays benefits in terms of texture and Al-coordination, the latter with full preservation of the tetrahedral A
Evidencia de puntos calientes a nivel microscópico durante la calcinación de la meso fase Si-MCM-41 mediante SAXS
En este estudio se investigó el fenómeno de puntos-calientes a nivel microscópico durante la calcinación del MCM-41, cuantificando la magnitud de la temperatura alcanzada durante la calcinación de la meso fase del MCM- 41; por medio de un estudio comparativo de SAXS. Esto fue deducido por tratamiento térmico del material, al cual se le removió el surfactante por medio de Química Fenton seguido por el equilibrio y secado en presencia de un solvente de baja tensión superficial (N,N-Dimetilformamida y n-Butanol); estas muestras presentan baja contracción estructural. Las muestras obtenidas fueron tratadas térmicamente a varios incrementos de
temperatura con el propósito de simular la contracción que sufrirían las muestras por calcinación directa. Para comparar la contracción estructural, se encontró que la temperatura microscópica alcanzada está entre 190 y 250 C, deducida a partir de N,N-Dimetilformamida o n-Butanol. El orden de magnitud del incremento de temperatura alcanzada parece ser consistente con el bien conocido efecto de incandescencia, éste es sin embargo, relativamente alto comparado con el aumento de temperatura macroscópica experimentalmente determinada.In this study, we investigated the phenomenon of microscopic hot-spots during the calcination of MCM-41, by quantifying the magnitude of the temperature rise during the calcination of a soft MCM-41 mesophase using a SAXS comparative study. This was deduced by thermally treating a soft material that was detemplated by Fenton chemistry followed by equilibration and drying in a low surface tension solvent (N,N-Dimethylformamide and n-BuOH); these samples have limited structural shrinkage. The so-derived samples were thermally treated at increasing temperatures in order to mimic the shrinkage of the direct calcination. By comparing the structural shrinkage, it was found that the microscopic temperature rise would lies between 190 and 250 C, as deduced
from n-BuOH or N,N-Dimethylformamide. The order of magnitude of the temperature rise appears to be consistent with the well-known glow effect; it is however relatively higher to the macroscopic temperature rise determined experimentally
Abu Zenima synthetic zeolite for removing iron and manganese from Assiut governorate groundwater, Egypt
E-portfolio design for the acquisition of transversal competences in Education for the Sustainability
Diseño de un portafolio digital, incluido sistema de rúbrica, para integrar la Educación para la Sostenibilidad en la enseñanza-aprendizaje de las ciencias experimentales favoreciendo el empleo de las TIC y competencias como el razonamiento reflexivo.Design of a digital portfolio, including a rubric system, to integrate Education for the Sustainability in the teaching-learning of science. This promotes ICT use and critical thinking.Depto. de Didáctica de las Ciencias Experimentales , Sociales y MatemáticasFac. de EducaciónFALSEsubmitte
Reorientation of Chemistry education to enhace pre-service teacher training in the field of professional competences in Education for Sustainability
En el presente proyecto se ha elaborado una guía de orientación para la enseñanza-aprendizaje de la Química que incluye contenidos teóricos, cuestionarios y una propuesta de actividades dirigidas a promover la adquisición de competencias en Educación para la Sostenibilidad. Se emplearon diferentes metodologías en el desarrollo de las actividades: enseñanza basada en la indagación, Design For Change (design thinking), gamificación y aprendizaje basado en proyectos (diseño de un cultivo acuapónico). Los estudiantes crearon un portafolio digital para recopilar todos los resultados de las actividades y sus reflexiones personales.In the present project, an orientation guide for the teaching-learning of Chemistry was prepared, which includes theoretical content, questionnaires and a proposal of activities aimed at promoting the acquisition of competences in Education for Sustainability. Different methodologies were used in the development of the activities: inquiry-based teaching, Design For Change (design thinking), gamification and project-based learning (design of an aquaponic culture). Students create a digital portfolio to collect all the results of the activities and their personal reflections.Depto. de Didáctica de las Ciencias Experimentales , Sociales y MatemáticasFac. de EducaciónFALSEsubmitte
Oxygen tension during in vitro oocyte maturation and fertilization affects embryo quality in sheep and deer
Incubation gas atmosphere affects the development of in vitro produced embryos. In this study, there was examination of effects of two different oxygen (O2) tensions (5 % and 21 %) during in vitro maturation (M5 and M21) and/or fertilization (F5 and F21) on embryo production and quality in deer and sheep. There was assessment of the percentage of embryos with cell cleavage occurring, percentage that developed to the blastocyst stage, and analysis of the relative abundance of mRNA transcript for genes important for development to the blastocyst stage. The O2 tension treatment did not affect (P > 0.05) percentage cleavage or blastocyst development in either species. In sheep, there was a greater abundance of SHC1, GPX1, TP53, BAX and NRF1 mRNA transcript (P < 0.05) in M21 F5-derived embryos. In deer, there was a greater abundance of SOD2 mRNA transcript (P < 0.05) when oocytes had been matured under relatively lesser O2, regardless of the tension used during fertilization. There was a lesser abundance of SOX2 mRNA transcript (P < 0.05) in the M5F21 compared to the other three treatment groups. The AKR1B1 mRNA transcript was in greater abundance (P < 0.05) in M21 F21 as compared to M21 F5 and M5F21 group, and there was a greater abundance PLAC8 mRNA transcript (P < 0.05) in M21 F21, as compared to all other treatment groups. In conclusion, while O2 tension had no effect on developmental rates it did affect the relative abundance of mRNA transcript of multiple genes related to important cell functions during development.This research was supported by the Spanish Ministry of Economy and Competitiveness (AGL2013-48421-R and AGL2015-66145-R). MIC was supported by a Ministry of Economy and Competitiveness scholarship and PPF was supported by a University of Castilla-La Mancha scholarship.Peer reviewe
Science is in the news
Este proyecto describe una propuesta didáctica orientada a la enseñanza de la ciencia a través del uso de noticias de los medios de comunicación. El objetivo principal es mejorar la comprensión de los estudiantes sobre conceptos científicos al mismo tiempo que fomenta un enfoque crítico y responsable hacia los temas que se tratan en dichas noticias. Al incorporar ejemplos del mundo real y eventos actuales, el proyecto busca involucrar a los estudiantes y promover una comprensión más profunda de los temas científicos.This project describes a teaching proposal of science education through the utilization of news from the media. The primary goal is to enhance students' comprehension of scientific concepts while fostering a critical and responsible approach to the issues discussed in these news articles. By incorporating real-world examples and current events, the project seeks to engage students and promote a deeper understanding of scientific topics.Depto. de Didáctica de las Ciencias Experimentales , Sociales y MatemáticasFac. de EducaciónFALSEsubmitte
Fomentando la educación para la sostenibilidad en la formación de maestros a través de espacios verdes -Huerto Didáctico y Real Jardín Botánico- como recursos educativos
El presente documento es la memoria del proyecto de innovación docente "Fomentando la educación para la sostenibilidad en la formación de maestros a través de espacios verdes -Huerto Didáctico y Real Jardín Botánico- como recursos educativos". En dicha memoria se especifican los objetivos propuestos, esto es que los/as alumnos/as adquieran conocimientos vinculados con la biología y la ecología, así como competencias transversales como el pensamiento reflexivo y valores democráticos y de sostenibilidad trabajando en espacios verdes. Se reportan las actividades realizadas en el Huerto Didáctico de la Facultad de Educación-CFP de la UCM y en el Real Jardín Botánico Alfonso XIII para la consecución de esos objetivos, concluyendo que los alumnos son capaces de aprender sobre la materia y ejecutar tareas de cuidado hortícola, a la vez que conectar con el medio natural cuando llevan a cabo actividades en los espacios verdes de la UCM