9 research outputs found

    Assessment activities in Mechanics: How many of them are enough?

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    The following presents the results of a set of continuous assessment activities undertaken in the subjects of Theory of Mechanics and Mechanisms, in order to analyse if the amount of the assessment activities performed during the course, their level and the method to perform them have influence on the student’s subject failure. During five academic years, the evaluation system have changed the amount and form of assessment exercises done along the course, or in many cases just simplifying them. The results point out that as higher is the perception of amount of work that students notice, higher is the success of the students in the subject. Peculiarly, the decrease in the number of assessment activities increases the subject drop-off. Equally, the recurrence of the assessment model during two consecutive semesters may be the cause of lack of motivation that some students show, principally, those who repeated the subjects. To reduce the level of failure in Mechanics, we are performing a new way to do the assessment activities, during this academic year 2016-17, the so-called Agile project, instead to reduce or eliminate these exercises. Consequently, we will have the first results of applying this methodology at the end of January. The Agile is based on principles of collaboration between students, adaptability and non-stop improvement of the work done. Its objective is to deliver a product to a client at the end of the course. However, the product has to be performed in successive steps through both semesters. Each step is called Sprint. The Sprint duration is two weeks and it has a list of requests to do. At the end of each Sprint, each team shows its product increase achieved during this period. Additionally, the team has to facilitate the activities that they have done to perform the Sprint, specifying who has done each task. This methodology, thus, requires continuous work of the team. In spite of the work that this new methodology supposes, with this way to perform the assessment activities, we may avoid, firstly, last minute poor delivered exercises and secondly, to reduce the level of failure in Mechanics.Postprint (published version

    Anàlisi de les qualificacions obtingudes amb una estrategia docent ludificada. Cas pràctic en assignatures de l’àmbit de l’enginyeria mecànica

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    Es presenta l‚Äėan√†lisi de la correlaci√≥ entre les qualificacions de proves avaluadores tradicionals i les obtingudes amb q√ľestionaris ludificats. S‚Äôha desenvolupat un m√®tode per obtenir de forma automatitzada unes qualificacions amb diferents criteris de ponderaci√≥ (penalitzaci√≥ de les respostes incorrectes, segons el temps de resposta i la normalitzaci√≥ de les qualificacions). Els resultats mostren correlacions significatives que suggereixen l‚Äô√ļs de les activitats ludificades en l‚Äôavaluaci√≥ sumativa.Peer ReviewedObjectius de Desenvolupament Sostenible::4 - Educaci√≥ de QualitatPostprint (published version

    Improvement of the one-way and two-way shape memory effects in ti-ni shape memory alloys by thermomechanical treatments

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    Ti-Ni phase transformation behaviour is very sensitive to the thermal and mechanical history of the alloy. Thermomechanical cycling through the full transformation range may degrade the Ti-Ni functional properties (functional fatigue). These repeated transformation cycles cause changes in the SMA phase transformation behaviour due to the formation and accumulation of defects in the alloy microstructure. The main objective of this thesis is to establish the relationships between the changes in Ti-Ni phase transformation behaviour caused by thermomechanical processes, especially in the R-phase range, and the functional properties of the Ti-Ni shape memory alloys (SMAs). Establishing these relationships should allow us to find appropriate thermomechanical processes to substantially improve the Ti-Ni one-way and two-way shape memory effects. To achieve this objective, several experimental techniques are used including measuring variations of the electrical resistivity with temperature, X-ray diffraction, isothermal tension testing, thermal cycling under constant stress, and thermal cycling under zero stress. This study of the phase transformation changes caused by thermomechanical processes has led to a new way of interpreting resistivity curves for calculating the transformation temperatures. Moreover, we have determined how the R-phase influences the functional properties of SMA and, finally, we have substantially improved the properties of one-way and two-way shape memory effects by using thermal processes that avoid permanent deformation of the alloy.Las transformaciones de fase en aleaciones de NiTi son altamente dependientes de la composici√≥n de la aleaci√≥n, as√≠ como de la historia t√©rmica y mec√°nica previa al uso de la SMA. El objetivo principal de esta tesis es establecer los v√≠nculos existentes entre los cambios producidos en las transformaciones de fase por procesos termomec√°nicos y las propiedades funcionales en aleaciones con memoria de forma de Ti-Ni, tal que nos permita hallar los procesos termomec√°nicos m√°s adecuados que proporcionen una mejora substancial en las propiedades funcionales de estas aleaciones. La determinaci√≥n de estas relaciones, prestando especial atenci√≥n a la fase-R, nos debe proporcionar las claves para incrementar las propiedades de memoria de forma y doble memoria de forma. Para la consecuci√≥n de este objetivo se han usado diferentes t√©cnicas de caracterizaci√≥n experimental: variaci√≥n de la resistividad el√©ctrica con la temperatura (ER), difractometr√≠a de rayos X (DRX), ensayos de tracci√≥n isot√©rmicos, ciclados t√©rmicos a tensi√≥n constante y ciclados t√©rmicos a tensi√≥n nula. A trav√©s del estudio exhaustivo de las transformaciones de fase, se ha aportado una nueva interpretaci√≥n de las curvas de resistividad para el c√°lculo de las temperaturas de transformaci√≥n, se ha determinado la influencia de la fase-R en las propiedades funcionales de las SMA y se han mejorado substancialmente las propiedades de memoria simple y doble memoria de forma mediante procesos t√©rmicos que evitan deformaciones permanentes antes del uso de la aleaci√≥n.Les transformacions de fase en aliatges de NiTi s√≥n altament dependents de la composici√≥ de l'aliatge, aix√≠ com de la hist√≤ria t√®rmica i mec√†nica pr√®via a l'√ļs de la SMA. L'objectiu principal d'aquesta tesi √©s establir els vincles existents entre els canvis produ√Įts en les transformacions de fase per processos termomec√†nics i les propietats funcionals en aliatges amb mem√≤ria de forma de Ti-Ni, tal que ens permeti trobar els processos termomec√†nics m√©s adequats que proporcionin una millora substancial en les propietats funcionals d'aquests aliatges. La determinaci√≥ d'aquestes relacions, prestant especial atenci√≥ a la fase-R, ens ha de proporcionar les claus per incrementar les propietats de mem√≤ria de forma i doble mem√≤ria de forma. Per a la consecuci√≥ d'aquest objectiu s'han usat diferents t√®cniques de caracteritzaci√≥ experimental: variaci√≥ de la resistivitat el√®ctrica amb la temperatura (ER), difractometria de raigs X (DRX), assaigs de tracci√≥ isot√®rmics, ciclats t√®rmics a tensi√≥ constant i ciclats t√®rmics a tensi√≥ nula. A trav√©s de l'estudi exhaustiu de les transformacions de fase, s'ha aportat una nova interpretaci√≥ de les corbes de resistivitat per al c√†lcul de les temperatures de transformaci√≥, s'ha determinat la influ√®ncia de la fase-R en les propietats funcionals de les SMA i s'han millorat substancialment les propietats de mem√≤ria simple i doble mem√≤ria de forma mitjan√ßant processos t√®rmics que eviten deformacions permanents abans de l'√ļs de l'aliatge

    Assessment activities in Mechanics: How many of them are enough?

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    The following presents the results of a set of continuous assessment activities undertaken in the subjects of Theory of Mechanics and Mechanisms, in order to analyse if the amount of the assessment activities performed during the course, their level and the method to perform them have influence on the student’s subject failure. During five academic years, the evaluation system have changed the amount and form of assessment exercises done along the course, or in many cases just simplifying them. The results point out that as higher is the perception of amount of work that students notice, higher is the success of the students in the subject. Peculiarly, the decrease in the number of assessment activities increases the subject drop-off. Equally, the recurrence of the assessment model during two consecutive semesters may be the cause of lack of motivation that some students show, principally, those who repeated the subjects. To reduce the level of failure in Mechanics, we are performing a new way to do the assessment activities, during this academic year 2016-17, the so-called Agile project, instead to reduce or eliminate these exercises. Consequently, we will have the first results of applying this methodology at the end of January. The Agile is based on principles of collaboration between students, adaptability and non-stop improvement of the work done. Its objective is to deliver a product to a client at the end of the course. However, the product has to be performed in successive steps through both semesters. Each step is called Sprint. The Sprint duration is two weeks and it has a list of requests to do. At the end of each Sprint, each team shows its product increase achieved during this period. Additionally, the team has to facilitate the activities that they have done to perform the Sprint, specifying who has done each task. This methodology, thus, requires continuous work of the team. In spite of the work that this new methodology supposes, with this way to perform the assessment activities, we may avoid, firstly, last minute poor delivered exercises and secondly, to reduce the level of failure in Mechanics

    Assessment activities in Mechanics: How many of them are enough?

    No full text
    The following presents the results of a set of continuous assessment activities undertaken in the subjects of Theory of Mechanics and Mechanisms, in order to analyse if the amount of the assessment activities performed during the course, their level and the method to perform them have influence on the student’s subject failure. During five academic years, the evaluation system have changed the amount and form of assessment exercises done along the course, or in many cases just simplifying them. The results point out that as higher is the perception of amount of work that students notice, higher is the success of the students in the subject. Peculiarly, the decrease in the number of assessment activities increases the subject drop-off. Equally, the recurrence of the assessment model during two consecutive semesters may be the cause of lack of motivation that some students show, principally, those who repeated the subjects. To reduce the level of failure in Mechanics, we are performing a new way to do the assessment activities, during this academic year 2016-17, the so-called Agile project, instead to reduce or eliminate these exercises. Consequently, we will have the first results of applying this methodology at the end of January. The Agile is based on principles of collaboration between students, adaptability and non-stop improvement of the work done. Its objective is to deliver a product to a client at the end of the course. However, the product has to be performed in successive steps through both semesters. Each step is called Sprint. The Sprint duration is two weeks and it has a list of requests to do. At the end of each Sprint, each team shows its product increase achieved during this period. Additionally, the team has to facilitate the activities that they have done to perform the Sprint, specifying who has done each task. This methodology, thus, requires continuous work of the team. In spite of the work that this new methodology supposes, with this way to perform the assessment activities, we may avoid, firstly, last minute poor delivered exercises and secondly, to reduce the level of failure in Mechanics

    An√°lisis de las calificaciones en actividades ludificadas

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    Desde hace unos a√Īos se ha extendido el uso de estrategias docentes donde se utiliza la ludificaci√≥n mediante sistemas personales de respuesta en directo en el aula. Diferentes autores han contrastado las ventajas del uso de estas herramientas en el proceso de ense√Īanza aprendizaje, pero hay discrepancias en el uso de las calificaciones obtenidas en las actividades ludificadas. Algunos autores sostienen que las calificaciones obtenidas en estas actividades ludificadas s√≥lo deben formar parte de la evaluaci√≥n formativa y no formar parte de la evaluaci√≥n sumativa. No obstante, los autores de este trabajo, en las fases iniciales de su investigaci√≥n observaron una correlaci√≥n significativa entre las calificaciones obtenidas en los cuestionarios ludificados via Kahoot! y las calificaciones obtenidas en el resto de las pruebas realizadas como ex√°menes y las calificaciones obtenidas en la asignatura. Las calificaciones que se pueden obtener de Kahoot! no sirven para extraer directamente una calificaci√≥n num√©rica para cada usuario en una escala acotada (rango de 0 a 10 puntos). Para comparar los resultados de la ludificaci√≥n con el resto de elementos de evaluaci√≥n, se ha desarrollado un sistema automatizado de obtenci√≥n de las calificaciones en un rango de 0 a 10 puntos. Estas calificaciones difieren entre ellas dependiendo de los criterios de ponderaci√≥n: penalizaci√≥n de las respuestas incorrectas, tiempo de respuesta y normalizaci√≥n de las notas entre el grupo clase. Los resultados que se obtienen son los coeficientes de correlaci√≥n entre los cuestionarios Kahoot! y el resto de elementos evaluadores, los p-valores correspondientes y una representaci√≥n visual de estas correlaciones. El principal resultado del an√°lisis estad√≠stico es que en funci√≥n de la metodolog√≠a de la asignatura y el enfoque de los cuestionarios ludificados hay una correlaci√≥n significativa entre las calificaciones obtenidas en los cuestionarios ludificados y los sistemas de evaluaci√≥n tradicional. Adem√°s, se ha creado un sistema de puntuaci√≥n en funci√≥n del porcentaje de aciertos del grupo clase, que permite evaluar la calidad de las preguntas de los cuestionarios, clasificar la dificultad del cuestionario y as√≠ poder diferenciarlos seg√ļn este criterio para el an√°lisis con el resto de elementos evaluadores.Peer ReviewedPostprint (published version

    The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project

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    The PREDICTS project‚ÄĒProjecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)‚ÄĒhas collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity

    The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project

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    Rare predicted loss-of-function variants of type I IFN immunity genes are associated with life-threatening COVID-19

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    BackgroundWe previously reported that impaired type I IFN activity, due to inborn errors of TLR3- and TLR7-dependent type I interferon (IFN) immunity or to autoantibodies against type I IFN, account for 15-20% of cases of life-threatening COVID-19 in unvaccinated patients. Therefore, the determinants of life-threatening COVID-19 remain to be identified in similar to 80% of cases.MethodsWe report here a genome-wide rare variant burden association analysis in 3269 unvaccinated patients with life-threatening COVID-19, and 1373 unvaccinated SARS-CoV-2-infected individuals without pneumonia. Among the 928 patients tested for autoantibodies against type I IFN, a quarter (234) were positive and were excluded.ResultsNo gene reached genome-wide significance. Under a recessive model, the most significant gene with at-risk variants was TLR7, with an OR of 27.68 (95%CI 1.5-528.7, P=1.1x10(-4)) for biochemically loss-of-function (bLOF) variants. We replicated the enrichment in rare predicted LOF (pLOF) variants at 13 influenza susceptibility loci involved in TLR3-dependent type I IFN immunity (OR=3.70[95%CI 1.3-8.2], P=2.1x10(-4)). This enrichment was further strengthened by (1) adding the recently reported TYK2 and TLR7 COVID-19 loci, particularly under a recessive model (OR=19.65[95%CI 2.1-2635.4], P=3.4x10(-3)), and (2) considering as pLOF branchpoint variants with potentially strong impacts on splicing among the 15 loci (OR=4.40[9%CI 2.3-8.4], P=7.7x10(-8)). Finally, the patients with pLOF/bLOF variants at these 15 loci were significantly younger (mean age [SD]=43.3 [20.3] years) than the other patients (56.0 [17.3] years; P=1.68x10(-5)).ConclusionsRare variants of TLR3- and TLR7-dependent type I IFN immunity genes can underlie life-threatening COVID-19, particularly with recessive inheritance, in patients under 60 years old
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