A web-based application for the management and evaluation of tutoring requests in PBL-based massive laboratories

One important steps in a successful project-based-learning methodology (PBL) is the process of providing the students with a convenient feedback that allows them to keep on developing their projects or to improve them. However, this task is more difficult in massive courses, especially when the project deadline is close. Besides, the continuous evaluation methodology makes necessary to find ways to objectively and continuously measure students' performance without increasing excessively instructors' work load. In order to alleviate these problems, we have developed a web service that allows students to request personal tutoring assistance during the laboratory sessions by specifying the kind of problem they have and the person who could help them to solve it. This service provides tools for the staff to manage the laboratory, for performing continuous evaluation for all students and for the student collaborators, and to prioritize tutoring according to the progress of the student's project. Additionally, the application provides objective metrics which can be used at the end of the subject during the evaluation process in order to support some students' final scores. Different usability statistics and the results of a subjective evaluation with more than 330 students confirm the success of the proposed application

Linear optical conductivity of chiral multifold fermions

Chiral multifold fermions are quasiparticles described by higher spin generalizations of the Weyl equation, and are realized as low energy excitations near symmetry protected band crossings in certain chiral crystals. In this work we calculate the linear optical conductivity of all chiral multifold fermions. We show that it is enhanced with respect to that of Weyl fermions with the same Fermi velocity, and features characteristic activation frequencies for each multifold fermion class, providing an experimental fingerprint to detect them. We calculate the conductivity for realistic chiral multifold semimetals by using lattice tight-binding Hamiltonians that match the effective models of multifold fermions at low energies, for space groups 199 and 198. The latter includes RhSi, for which we give quantitative predictions, and also CoSi and AlPt. Our predictions can be tested in absorption or penetration depth measurements, and are necessary to extract the recently proposed quantized photocurrents from experiments.Comment: 15 pages, 10 figures. Accepted versio

New teaching methodology for electronics and its adaptation to the European space for higher education

There is a widespread consensus that aims to the flexibility of the subjects, both in terms of times and places when and where they are taught as one of the main factors that increase or enhance their appeal for students. The deployment of a new remote access platform tailored to the specific needs of students in a course on digital electronic systems based on microprocessors has enabled them to enjoy greater flexibility by offering them the ability to complete remotely, in a different time and place to the university, the proposed practices (PBL) simultaneously with the lectures. This remarkable improvement, endorsed by the results of a survey among the students, has had a particularly positive impact on the impression students have of the subject, and has contributed significantly to improve its assessment and the participation in it

Estimation of Key Dates and Stages in Rice Crops Using Dual-Polarization SAR Time Series and a Particle Filtering Approach

Information of crop phenology is essential for evaluating crop productivity. In a previous work, we determined phenological stages with remote sensing data using a dynamic system framework and an extended Kalman filter (EKF) approach. In this paper, we demonstrate that the particle filter is a more reliable method to infer any phenological stage compared to the EKF. The improvements achieved with this approach are discussed. In addition, this methodology enables the estimation of key cultivation dates, thus providing a practical product for many applications. The dates of some important stages, as the sowing date and the day when the crop reaches the panicle initiation stage, have been chosen to show the potential of this technique.This work was supported in part by the Spanish Ministry of Economy and Competitiveness (MINECO) and EU FEDER under Project TEC2011-28201-C02-02, and in part by the Generalitat Valenciana under Project ACOMP/2014/136. All SAR images have been provided by DLR in the framework of projects LAN0021 and LAN0234 of the prelaunch AO of TerraSAR-X

Particle Filter Approach for Real-Time Estimation of Crop Phenological States Using Time Series of NDVI Images

Knowing the current phenological state of an agricultural crop is a powerful tool for precision farming applications. In the past, it has been estimated with remote sensing data by exploiting time series of Normalised Difference Vegetation Index (NDVI), but always at the end of the campaign and only providing results for some key states. In this work, a new dynamical framework is proposed to provide real-time estimates in a continuous range of states, for which NDVI images are combined with a prediction model in an optimal way using a particle filter. The methodology is tested over a set of 8 to 13 rice parcels during 2008–2013, achieving a high determination factor R2=0.93 ( n=379 ) for the complete phenological range. This method is also used to predict the end of season date, obtaining a high accuracy with an anticipation of around 40–60 days. Among the key advantages of this approach, phenology is estimated each time a new observation is available, hence enabling the potential detection of anomalies in real-time during the cultivation. In addition, the estimation procedure is robust in the case of noisy observations, and it is not limited to a few phenological stages.This work is supported by the Spanish Ministry of Economy and Competitiveness (MINECO) and EU FEDER under Projects TEC2011-28201-C02-02 and TIN2014-55413-C2-2-P

La membresía en asociaciones y el sentimiento de solidaridad como factores que inciden en la participación política de los jóvenes en el Área Metropolitana de Monterrey

La participación política de los jóvenes en edades entre 18 y 29 años es imprescindible para el desarrollo de la democracia en el Estado de Nuevo León. Por lo que, el presente trabajo tiene como objetivo identificar el nivel explicativo de la membresía en asociaciones, así como el sentimiento de solidaridad como elementos del capital social, los cuales revelan la participación política (electoral, convencional y no convencional) de los jóvenes. La metodología utilizada para el presente estudio es de corte cuantitativo, el trabajo de campo se realizó con financiamiento del Programa para el Desarrollo Profesional Docente (PRODEP). En lo que respecta a los resultados más relevantes se encontró que la variable membresía en asociaciones no se relaciona con la participación electoral, sin embargo, si se relaciona con la participación política convencional y no convencional; de igual manera, los resultados revelaron que en la variable sentimiento de solidaridad no existe relación con la participación electoral, y si se encuentra una relación con la participación política convencional y no convencional. ABSTRACT The political participation of young people between the ages of 18 and 29 is essential for the development of democracy in the State of Nuevo León. Therefore, the objective of this study is to identify the explanatory level of membership in associations, as well as the feeling of solidarity as elements of social capital, which reveal the political participation (electoral, conventional and unconventional) of young people. The methodology used for the present study is quantitative. With regard to the most relevant results, it was found that the variable membership in associations is not related to electoral participation, however, if it is related to conventional and non-conventional political participation; In the same way, the results revealed that in the variable sense of solidarity there is no relation with electoral participation, and if there is a relation with conventional and nonconventional political participation

Yield models for predicting aboveground ectomycorrhizal fungal productivity in Pinus sylvestris and Pinus pinaster stands of northern Spain

Background Predictive models shed light on aboveground fungal yield dynamics and can assist decision-making in forestry by integrating this valuable non-wood forest product into forest management planning. However, the currently existing models are based on rather local data and, thus, there is a lack of predictive tools to monitor mushroom yields on larger scales. Results This work presents the first empirical models for predicting the annual yields of ectomycorrhizal mushrooms and related ecosystem services in Pinus sylvestris and Pinus pinaster stands in northern Spain, using a long-term dataset suitable to account for the combined effect of meteorological conditions and stand structure. Models were fitted for the following groups of fungi separately: all ectomycorrhizal mushrooms, edible mushrooms and marketed mushrooms. Our results show the influence of the weather variables (mainly precipitation) on mushroom yields as well as the relevance of the basal area of the forest stand that follows a right-skewed unimodal curve with maximum predicted yields at stand basal areas of 30–40?m2·ha-?1. Conclusion These models are the first empirical models for predicting the annual yields of ectomycorrhizal mushrooms in Pinus sylvestris and Pinus pinaster stands in northern Spain, being of the highest resolution developed to date and enable predictions of mushrooms productivity by taking into account weather conditions and forests’ location, composition and structure

Comparison between the reactivity of coal and synthetic coal models

A mixture of carbon compounds was pyrolysed under an inert atmosphere at different temperatures in a fixed bed reactor. The resultant chars were characterised in terms of texture and thermal behaviour. Textural characterisation of the chars was carried out by N2 and CO2 adsorption isotherms at −196 and 0 °C, respectively. Char isothermal reactivity in air at 500 °C, and in CO2 at 1000 °C, was performed in a thermogravimetric analyser (TGA). Temperature-programmed combustion tests under 20% oxygen in argon were also performed in the TGA linked to a mass spectrometer (TGA/MS). The results showed that char textural properties do not always relate well to their reactivity. Not only do physical properties (e.g. surface area, porosity) but also chemical properties (e.g. active sites concentration and distribution) play an important role in the reaction of carbonaceous material and oxidant. On the other hand, in terms of chemical composition the chars obtained from the mixture of carbon compounds were very similar to the chars produced under the same experimental conditions by a high volatile bituminous coal. The fact that carbon compounds are well known makes it easier to obtain knowledge about the functional groups present in synthetic char, and to study the mechanisms of heterogeneous reactions such as the reduction of NO with carbon.Peer reviewe