Experiencias de cátedra en las clases de física de primer curso de Escuelas Técnicas

We have performed a set of lecture room experiences in a Physics course at the Escuela Universitaria de Informática, of the Universidad Politécnica de Valencia; we have studied the effects produced on the students. This paper shows that we can prepare and perform this method easily, and also its low cost. On the other hand, the general assessment of the students is positive, and it is particularly helpful to improve the motivation and the understanding of the concepts

Estudio sobre la heterogeneidad de conocimientos básicos en alumnos de primer curso de universidades politécnicas

El trabajo analiza los resultados de un test relativo a conocimientos básicos de Matemáticas y Física realizado con alumnos de primer curso de la Escuela Universitaria de Informática (EUD y de la Escuela Técnica Superior de Ingenieros de Telecomunicaciones (ETSIT) de la Universidad Politécnica de Valencia, durante los cursos 1996-97 y 1997-98. Los resultados se analizan estableciendo comparaciones según el Centro (EUI y ETSIT) y según procedencia (COU y FP)

Conformational mobility in a polymer with mesogenic side groups- dielectric and DSC studies

The relaxation times of the conformational rearrangements of the main-chain segments of a liquid crystalline side-chain polymer was determined from differential scanning calorimetry experiments in the temperature interval around and below its glass transition. Phenomenological models with fitting parameters were used to evaluate the temperature dependence of the relaxation times and the form parameter of the relaxation times distribution. These parameters were compared with its counterparts in the dielectric a relaxation process which appear in the temperature interval immediately above the calorimetric glass transition. For the temperature interval below the calorimetric glass transition the differential scanning calorimetry (DSC) results were compared with the dielectric results obtained by the thermally stimulated depolarisation technique

Validation of Student Peer Assessment of Effective Oral Communication in Engineering Degrees

© 2018 IEEE. Personal use of this material is permitted. Permissíon from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertisíng or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.[EN] Peer assessment is a form of collaborative learning in which students evaluate learning products prepared by other students. We present the results of an analysis of the assessment of oral presentations by students. A group of students solves a problem, writes a document with the solution, and makes an oral presentation in class to other students. Another group assesses the written document and oral presentation. To help students perform the assessments, two rubrics are provided along with other guidance documents that help in writing scientific documents and performing oral presentations. The rubric evaluates five factors of oral communication. The results of the student evaluations are compared with the simultaneous evaluations produced by two lecturers. When making a comparison of the global assessment between lecturers and students, we find significant differences. However, when the factor "use of auxiliary resources" is removed, these differences disappear as the factor introduces a difficult to justify dispersion. In addition, the assessment performed by students with and without the help of a rubric is compared and no significant differences are found.Meseguer Dueñas, JM.; Vidaurre, A.; Molina Mateo, J.; Riera Guasp, J.; Martínez Sala, RM. (2018). Validation of Student Peer Assessment of Effective Oral Communication in Engineering Degrees. IEEE-RITA: Latin-American Learning Technologies Journal. 13(1):11-16. https://doi.org/10.1109/RITA.2018.2801897S111613

Students perception of auto-scored online exams in blended assessment: feedback for improvement

[ES] El desarrollo de las tecnologías de la información y la comunicación ha producido un incremento del uso de la Computer Based Assessment (CBA, evaluación basada en ordenadores). en la educación superior. En la última década, ha habido un debate sobre los exámenes online vs los escritos tradicionales. El objetivo del presente estudio ha sido verificar si los estudiantes tienen prejuicios sobre los exámenes online con corrección automática, y si ese es el caso, determinar los motivos. El estudio se realizó en el contexto de una evaluación mixta que implicó a 1200 estudiantes matriculados en una asignatura de física de primer curso universitario. De entre ellos, 463 respondieron a una encuesta anónima. Del análisis cuantitativo de la encuesta surgieron tres factores (etiquetados «F1-Learning», «F2-Use of Tool» y «F3-Assessment»), y se estableció una escala aditiva. Hemos encontrado diferencias significativas en el factor «F3-Assessment» en comparación con los otros dos factores, lo que indica una menor aceptación de la herramienta para la evaluación del estudiante. Parece ser que, a pesar de que los estudiantes están acostumbrados a los ordenadores, tienen una falta de confianza en los exámenes online. Para reforzar y matizar los resultados cuantitativos de la encuesta, incluimos una pregunta abierta y realizamos una entrevista a un pequeño grupo de 11 estudiantes. Aunque sus comentarios fueron en general positivos, especialmente sobre la facilidad de uso y sobre su utilidad para conocer el nivel alcanzado durante el proceso de aprendizaje, hubo algunas críticas sobre la claridad de las preguntas y el rigor del sistema de puntuación. Estos dos factores, entre otros, podrían ser la causa de la peor percepción del factor «F3-Assessment» y el origen de las reticencias de los estudiantes a los exámenes online y a la corrección automática.[EN] Development of the information and communication technologies has led to an increase in the use of Computer Based Assessment (CBA) in higher education. In the last decade, there has been a discussion on online versus the traditional pen-and-paper exams. The aim of this study was to verify whether students have reserves about auto-scored online exams, and if that is the case, to determine the reasons. The study was performed in the context of a blended assessment in which 1200 students were enrolled on a first-year physics university course. Among them, 463 answered an anonymous survey, supplemented by information obtained from an open-ended question and from interviews with students. Three factors (labelled `F1-Learning,¿ `F2-Use of Tool,¿ and `F3-Assessment¿) emerged from the quantitative analysis of the survey, and an additive scale was established. We found significant differences in the `F3-Assessment¿ factor compared to the other two factors, indicating a lower acceptance of the tool for student assessment. It seems that even though students are used to computers, they have a lack of confidence in online exams. We carried out an in-depth survey on this topic in the form of an open-ended question and by interviewing a small group of 11 students to confer strength and nuance to the quantitative results of the survey. Although their comments were in general positive, especially on ease-of-use and on its usefulness in indicating the level achieved during the learning process, there was also some criticism of the clarity of questions and the strictness system of marking. These two factors, among others, could have been the cause of the worse perception of F3-Assessment and the origin of the students¿ reluctances of online exams and automatic scoring.This work was supported by the Universitat Politècnica de València through the A15/16 Project (Convocatoria de Proyectos de Innovación y Convergencia de la UPV). We would like to thank the ICE in the Universitat Politècnica de València for their help, through the Innovation and Educational Quality Program and for supporting the team Innovación en Metodologías Activas para el Aprendizaje de la Física (e-MACAFI).Riera Guasp, J.; Ardid Ramírez, M.; Gómez-Tejedor, J.; Vidaurre, A.; Meseguer Dueñas, JM. (2018). Students perception of auto-scored online exams in blended assessment: feedback for improvement. Educacion XX1. 21(2):79-103. https://doi.org/10.5944/ educXX1.19559S7910321

PERCEPCIÓN DE LOS ESTUDIANTES ACERCA DE LOS EXÁMENES ONLINE CON CORRECCIÓN AUTOMÁTICA EN UNA EVALUACIÓN MIXTA: RETROALIMENTACIÓN PARA LA MEJORA

Development of the information and communication technologies has led to an increase in the use of Computer Based Assessment (CBA) in higher education. In the last decade, there has been a discussion on online versus traditional pen-and-paper exams. The aim of this study was to verify whether students have reserves about auto-scored online exams, and if that is the case, to determine the reasons. The study was performed in the context of a blended assessment in which 1200 students were enrolled on a first-year physics university course. Among them, 463 answered an anonymous survey, supplemented by information obtained from an open-ended question and from interviews with students. Three factors (labelled ‘F1-Learning,’ ‘F2-Use of Tool,’ and ‘F3-Assessment’) emerged from the quantitative analysis of the survey, and an additive scale was established. We found significant differences in the ‘F3-Assessment’ factor compared to the other two factors, indicating a lower acceptance of the tool for student assessment. It seems that even though students are used to computers, they have a lack of confidence in online exams. We carried out an in-depth survey on this topic in the form of an open-ended question and by interviewing a small group of 11 students to confer strength and nuance to the quantitative results of the survey. Although their comments were positive in general, especially on ease-of-use and on its usefulness in indicating the level achieved during the learning process, there was also some criticism of the clarity of questions and the strictness of the marking system. These two factors, among others, could have been the cause of the worse perception of F3-Assessment and the origin of the students’ reluctance towards online exams and automatic scoring.El desarrollo de las tecnologías de la información y la comunicación haproducido un incremento del uso de la Computer Based Assessment (CBA,evaluación basada en ordenadores). en la educación superior. En la últimadécada, ha habido un debate sobre los exámenes online vs los escritostradicionales. El objetivo del presente estudio ha sido verificar si los estudiantes tienen prejuicios sobre los exámenes online con corrección automática, y si ese es el caso, determinar los motivos. El estudio se realizó en el contexto de una evaluación mixta que implicó a 1200 estudiantes matriculados en una asignatura de física de primer curso universitario. De entre ellos, 463 respondieron a una encuesta anónima. Del análisis cuantitativo de la encuesta surgieron tres factores (etiquetados «F1-Learning», «F2-Use of Tool» y «F3-Assessment»), y se estableció una escala aditiva. Hemos encontrado diferenciassignificativas en el factor «F3-Assessment» en comparación con los otrosdos factores, lo que indica una menor aceptación de la herramienta parala evaluación del estudiante. Parece ser que, a pesar de que los estudiantes están acostumbrados a los ordenadores, tienen una falta de confianza en los exámenes online. Para reforzar y matizar los resultados cuantitativos de la encuesta, incluimos una pregunta abierta y realizamos una entrevista a un pequeño grupo de 11 estudiantes. Aunque sus comentarios fueron en general positivos, especialmente sobre la facilidad de uso y sobre su utilidad para conocer el nivel alcanzado durante el proceso de aprendizaje, hubo algunas críticas sobre la claridad de las preguntas y el rigor del sistema de puntuación.Estos dos factores, entre otros, podrían ser la causa de la peor percepción del factor «F3-Assessment» y el origen de las reticencias de los estudiantes a los exámenes online y a la corrección automática

Fluctuations of conformational mobility of macromolecules around the glass transition

[EN] The heterogeneity of local dynamics in disordered systems is behind some key features of glass transition. In order to improve our understanding of the molecular dynamics in disordered systems in the vicinity of the glass transition, different parameters have been proposed to quantitatively describe dynamical heterogeneity. In the case of polymers, free volume models relate the macromolecular mobility to the free or accessible volume. The relationship between dynamic heterogeneity and fluctuations of accessible volume seems straightforward. In the present work, the heterogeneity of local dynamics in polymeric systems is analyzed by computer simulation with the bond fluctuation model. The value of the accessible volume around each polymer chain is evaluated from a snapshot or static structure at each system state, resulting in a distribution of accessible volume that reflects system heterogeneity. The relationship between the average value and the standard deviation of free volume distributions at different temperatures fits amaster curve for different systems, regardless of the specific inter- and intramolecular interaction potentials that define each material. The dynamic slowdown around the glass transition is accompanied by a clear evolution of the mean value and shape of the accessible free volume distribution. The relative fluctuation of the dynamically accessible volume has been used as a parameter to quantitatively describe heterogeneity. The fluctuation varies with temperature with remarkable differences between the liquid and glassy states of the systems studied, presenting a peak at the glass transition temperature, which can be interpreted as a reflection of the distribution of local glass transition temperatures.The support from the Ministry of Economy and Competitiveness (Spain) through Project No. MAT2016-76039-C4-1-R (including the FEDER financial support) is gratefully acknowledged. R.S.S. acknowledges the support of the Ministry of Education, Culture and Sports (Spain) through the program "Estancias de movilidad de profesores e investigadores seniores en centros extranjeros de ensenanza superior e investigacion 2016 under Grant No. PRX16/00208". CIBER-BBN is an initiative funded by the VI National R&D&I Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program. CIBER Actions are financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund.Torregrosa Cabanilles, C.; Molina Mateo, J.; Sabater I Serra, R.; Meseguer Dueñas, JM.; Gómez Ribelles, JL. (2018). Fluctuations of conformational mobility of macromolecules around the glass transition. Physical Review E. 97(6):062605-1-062605-7. https://doi.org/10.1103/PhysRevE.97.062605S062605-1062605-797

Non-Markovian Methods in Glass Transition

[EN] A model for the heterogeneity of local dynamics in polymer and other glass-forming materials is provided here. The fundamental characteristics of the glass transition phenomenology emerge when simulating a condensed matter open cluster that has a strong interaction with its heterogeneous environment. General glass transition features, such as non-exponential structural relaxations, the slowing down of relaxation times with temperature and specific off-equilibrium glassy dynamics can be reproduced by non-Markovian dynamics simulations with the minimum computer resources. Non-Markovian models are shown to be useful tools for obtaining insights into the complex dynamics involved in the glass transition phenomenon, including whether or not there is a need for a growing correlation length or the relationship between the non-exponentiality of structural relaxations and dynamic heterogeneity.The APC was funded by the Spanish Ministry of Science, Innovations, and Universities through the RTI2018-097862-B-C21 Project (including the FEDER financial support). CIBER-BBN is an initiative funded by the VI National R&D&I Plan 2008¿2011, Iniciativa Ingenio 2010, Consolider Program. CIBER Actions are financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund.Torregrosa Cabanilles, C.; Molina Mateo, J.; Sabater I Serra, R.; Meseguer Dueñas, JM.; Gómez Ribelles, JL. (2020). Non-Markovian Methods in Glass Transition. Polymers. 12(9):1-14. https://doi.org/10.3390/polym12091997S11412

Computer simulation of the heterogeneity of segmental dynamics inamorphous polymers

The heterogeneity of local segmental dynamics in a polymer system is analyzed by computer simulation with the Bond Fluctuation Model. A different approach is proposed based on the concept of Dynamically Accessible Volume (DAV) due to the difficulties encountered in the characterization of this heterogeneity by means of the distribution of relaxation times. A DAV value is assigned to each polymer chain as the fraction of cells in its surroundings that could be occupied in one Monte Carlo Step. In this way it is possible to relate the mobility of a chain with the accessible volume around it, due to the relationship between DAV and diffusion coefficient. As temperature decreases in equilibrium the DAV distribution shifts towards lower values, its width decreases and the number of frozen molecules increases. The methodology proposed also provides a way of characterizing the evolution of segmental dynamics distribution in out of equilibrium states below glass transition temperatures.The authors would like to acknowledge the support provided by the Conselleria d'Educacio of the Generalitat Valenciana through the GV/2009/033 project. The translation of this paper was funded by the Universidad Politecnica de Valencia, Spain.Molina Mateo, J.; Torregrosa Cabanilles, C.; Sabater I Serra, R.; Meseguer Dueñas, JM.; Gómez Ribelles, JL. (2013). Computer simulation of the heterogeneity of segmental dynamics inamorphous polymers. Journal of Non-Crystalline Solids. 362:175-179. https://doi.org/10.1016/j.jnoncrysol.2012.11.034S17517936

Relaxation in non-Markovian models: From static to dynamic heterogeneity

[EN] Glass transition processes have often been explained in terms of wide distributions of relaxation times. By means of a simple stochastic model we here show how dynamic heterogeneity is the key to the emergence of the glass transition. A non-Markovian model representing a small open region of the amorphous material was previously shown to reproduce the time and thermal characteristic behavior of supercooled liquids and glasses. Due to the interaction of the open regions with their environment, the temperature dependence of the equilibrium relaxation times differs from the featureless behavior of the relaxation times of closed regions, whose static disorder does not lead to a glass transition, even with wider distributions of equilibrium relaxation times. The dynamic heterogeneity of the open region produces a glass transition between two different regimes: a faster-thanArrhenius and non-diverging growth of the supercooled liquid relaxation times and an average Arrhenius behavior of the ideal glass. The Kovacs' expansion gap was studied by evaluating the nonequilibrium distribution of relaxation times after the temperature quenches.Funding for open access charge: CRUE-Universitat Polit`ecnica de Val`encia. RSS and JMM acknowledge the Spanish Ministry of Science, Innovations and Universities through the RTI2018-097862-B-C21 Project (including the FEDER financial support). CIBER-BBN is an initiative funded by the VI National R&D&I Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program. CIBER Actions are financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund.Torregrosa Cabanilles, C.; Molina Mateo, J.; Sabater I Serra, R.; Meseguer Dueñas, JM.; Gómez Ribelles, JL. (2022). Relaxation in non-Markovian models: From static to dynamic heterogeneity. Journal of Non-Crystalline Solids. 576. https://doi.org/10.1016/j.jnoncrysol.2021.12124512124557