La argumentación de profesores de Química en formación inicial (“Práctica Profesional Docente II”): un estudio de caso en Colombia

Des de perspectives habituals de l'educació, s'evidencia que l'argumentació ha estat reduïda a una tècnica de la didàctica de les Ciències quan, en realitat, es tracta d'una mica més complex. Per aquesta raó, es fa necessari estudiar i comprendre les formes d'argumentació dels professors de Química en formació inicial, ja que són ells els que juguen un paper determinant en el foment de l'argumentació en els estudiants. La premissa que es defensa en aquesta tesi és que un professor de Química que aprèn a argumentar ensenya perquè s'aprengui argumentant, la qual cosa pot afavorir canvis rellevants en les pràctiques escolars.From common perspectives of education, it is evident that the argument has been reduced a technique of teaching Science when, in fact, it is more complex. About this reason, it is necessary to study and understand the forms of argument Teachers Chemistry in initial training, because they will play a key role in promoting of argument on students. The premise is defended in this thesis is that a teacher Chemistry teaches learning to argue for arguing is learned, which may favor significant changes in school practices.Desde perspectivas habituales de la educación, se evidencia que la argumentación ha sido reducida a una técnica de la didáctica de las Ciencias cuando, en realidad, se trata de algo más complejo. Por tal razón, se hace necesario estudiar y comprender las formas de argumentación de los profesores de Química en formación inicial, pues son ellos quienes juegan un papel determinante en el fomento de la argumentación en los estudiantes. La premisa que se defiende en esta tesis es que un profesor de Química que aprende a argumentar enseña para que se aprenda argumentando, lo cual puede favorecer cambios relevantes en las prácticas escolares

The spontaneous use of connectors and vocabulary in written argumentation: contributions to science literacy

En este estudio se asume la argumentación escrita como una habilidad cognitivo-lingüística que favorece la alfabetización científica. Bajo esta premisa, el uso variado de conectores y el empleo de términos y datos científicos como parte del vocabulario resultan sustanciales en la comunicación escrita dentro del ámbito de la ciencia escolar. En esta investigación se analiza el empleo de conectores y vocabulario realizado por cuatro estudiantes (entre 9 y 16 años de edad) a quienes se les propuso escribir espontáneamente (sin intervención del profesor) un cuento que incluyera las ciencias de la naturaleza. Los resultados indican que en los cuatro casos, los estudiantes carecen de un uso variado de conectores en el enlace de sus ideas, lo cual afecta la articulación y orientación del escrito. Frente al vocabulario científico empleado, en esta investigación se identificó que de manera espontánea los cuatro casos utilizan términos científicos en sus escritos. Sin embargo, se determinó un uso limitado de datos de tipo científico. Finalmente, se enfatiza en la necesidad de realizar investigaciones acerca de cómo emplear en la práctica escolar los conectores y el vocabulario espontáneo de los estudiantes para enriquecer su alfabetización científica a través de la argumentación escrita.This research assumes written argumentation as a cognitive-linguistic ability that promotes scientific literacy. The proper use of connectors and scientific data is essential for written communication in science education. This exploration concerns about the spontaneous use (without instructional intervention) of connectors and vocabulary of four students (9 to 16 years old) when they write a short story including science. The results indicate that in all four cases, students lack a varied use of words to connect ideas, which affects the writing comprehension. In addition, all four cases spontaneously use scientific terms to make a writing task. Nonetheless, a limited use of scientific data was identified. Finally, results confirm the necessity of more research in order to determine how to use spontaneous connectors and vocabulary to enrich students’ scientific literacy through written argumentation

Mechanical and physical characterization of composite bamboo-guadua products: Plastiguadua

The bamboo species Guadua angustifolia Kunth (Guadua) was subjected to different fibre extraction processes, chemically treated and used in combination with a set range of polymers to form various composite materials. Novel technologies and artisan methods for veneer production and fibre extraction were explored. Extensive experimental work was undertaken on the composites manufacture, mixes and arrangements to form flat sheets. Physical and mechanical properties of these sheets were assessed on two material configurations: Plastiguadua-L and Plastiguadua-P. The former was a laminated material with 70% by weight of thin veneers of Guadua and 30% thermoset polyester resin. The latter had a 1:1 ratio by weight of short fibre bundles and resin content respectively. For the mechanical characterization, bending, tensile and impact-Izod tests were undertaken. Rockwell hardness, UV, condensation and water absorption were carried out to assess their physical properties. Values obtained for the elastic properties of Plastiguadua-L were lower than those of Plastiguadua-P, whilst strength values showed the opposite response for both bending, tension and impact. Bending and tensile modulus of elasticity for the former were 3.96 GPa and 2.21 GPa respectively, and 4.61 GPa and 2.38 GPa respectively for the latter. Tensile and impact strength values obtained were 38.3 MPa and 20.73 MPa respectively for Plastiguadua-L and 157 J/m and 55 J/m respectively for Plastiguadua-P. Improved resistance to degradation was observed through the UV/condensation test on samples embedded on resin when compared to those with none or slight preservation treatments. Overall, the research project showcased a range of products manufactured by mixing different forms of Guadua fibres and mats with polymers and assessed the mechanical and physical features of two of them. The project focused on a holistic approach to the use and manufacture of bamboo products for engineering applications and as potential substitutes for wood applications

Annotated Bibliography of Papers Relevant to High-speed Rail, Regional Economic Development and Related Areas

With HSR continuing to be the target of investments around the world, and with even the United States elevating the place of HSR on its public agenda, we have developed this annotated bibliography of references on HSR, regional economic development and related areas. We hope it will be of value to researchers, teachers, students and practitioners. We make no claim of completeness but we can attest that all the references contained herein have been useful to the Regional Transportation Planning and High-speed Rail Research Group. In Section A, we include references on transportation investment and economic development in general. Section B considers the case of HSR and economic development on the local and urban scale while Section C deals with the national, regional and international levels. Section D includes references on economic geography and disparities among regions. In Section E, we include references on HSR and aviation. Section F presents references on transportation project (including HSR projects) financing and value capture mechanisms. Section G deals with HSR organization and reform and Section H discusses HSR integration policy. Finally, Section I discusses international HSR experiences and Section J concludes with references on the Northeast Corridor of the U.S. Each section is subdivided in two categories: 1) papers and 2) books, reports, and theses

Lean services aplicado en los procesos administrativos de la coordinación de proyecto social universitario y práctica profesional de la carrera de Ingeniería Industrial de la Pontificia Universidad Javeriana

Ingeniero (a) IndustrialPregrad

Análisis del esfuerzo residual en concreto para pavimento rígido reforzado con fibras metálicas y sintéticas

A través del presente trabajo, luego de efectuar una exploración general respecto a los conceptos asociados con los diferentes tipos de fibras empleadas y su aplicación en diversas clases de concreto, se efectúa la explicación detallada acerca de los ensayos realizados, a fin de generar un análisis y valoración del esfuerzo residual en concreto para pavimento rígido reforzado con fibras metálicas y sintéticas. Como resultado de los ensayos realizados, se podrá obtener un punto de vista objetivo, que comparado bajo términos de funcionalidad, eficiencia y rentabilidad, permitirá el desarrollo y generación de una nueva forma de mezcla que facilite el desarrollo de estructuras en pavimentos

Productivity of Passenger Rail Transportation Services in the Northeast Corridor

Technological changes, capital investment, organizational reforms, and external factors can impact railway productivity. Using non-parametric single-factor and multifactor productivity (SFP and MFP) Törnqvist trans-log index approaches, we evaluated the performance of high-speed rail (HSR) lines in the U.S. during FY 2002-2012. Intercity rail transportation in the NEC experienced considerable yet highly volatile productivity growth during FY 2002-2012, in the range of ~1-3% per year. Amtrak increased its ability to economically exploit the available capacity, but did not perform equally well on the supply side. The NEC became cumulatively 20% more productive on the demand side but only 3% on the supply side of productivity with respect to 2005 levels. Service changes, technical problems with trains, targeted capital investments, and economic recession and recovery were the main drivers of productivity change. The main train services, the Acela Express and Northeast Regional, were very sensitive to external events, had large economies of scale, and implemented slow adjustment of capacity via rolling stock and infrastructure improvements, which varied depending on the service. In the face of ongoing planning efforts, the NEC could consider the resurgence of demand and recent substantial productivity improvements to launch ambitious plans for HSR. Additional ideas of organization and coordination of rail could reveal hidden opportunities for future HSR development