Anàlisis de l'ús d'il·lustracions del material didàctic STEM al segon cicle de l'ESO

L'aprenentatge que es du a terme a l'etapa educativa es dona de manera conscient però també de manera inconscient. Les il·lustracions dels llibres de text, tot i ser elements beneficiosos que faciliten la comprensió del material didàctic, també constitueixen una font de transmissió d'aquest coneixement subliminar, per la qual cosa és decisiu saber com s'utilitzen. Aquest estudi analitza dos aspectes referents a l'ús de les il·lustracions dels llibres de text del segon cicle de l'ESO dins del context STEM. Per una banda, l'objectiu primer d'aquesta investigació és conèixer com es fa servir el codi icònic. Mitjançant un sistema d'indicadors elaborat ad hoc, es desenvolupa una anàlisi de les il·lustracions dels llibres de text de tres assignatures diferents: Tecnologia, Matemàtiques, i Física i Química. Els resultats mostren una varietat en l'ús de les il·lustracions per part de les editorials, però amb un cert patró d'ús segons les assignatures. Per l'altra, a l'escola, encara que no sigui d'una manera explícita, es fomenten i es legitimen estereotips de gènere, que suposen limitacions a les persones en funció del seu sexe. El segon objectiu d'aquest estudi és analitzar si la cultura codificada als llibres de text transmet coneixements sexistes. Els resultats d'aquest estudi, mostren un sexisme subtil a través de l'absència o infrarepresentació del sexe femení a les imatges dels llibres de text, respecte al sexe masculí

Even-dimensional topological gravity from Chern-Simons gravity

It is shown that the topological action for gravity in 2n-dimensions can be obtained from the 2n+1-dimensional Chern-Simons gravity genuinely invariant under the Poincare group. The 2n-dimensional topological gravity is described by the dynamics of the boundary of a 2n+1-dimensional Chern-Simons gravity theory with suitable boundary conditions. The field $\phi^{a}$, which is necessary to construct this type of topological gravity in even dimensions, is identified with the coset field associated with the non-linear realizations of the Poincare group ISO(d-1,1)

Generating Higher-Order Lie Algebras by Expanding Maurer Cartan Forms

By means of a generalization of the Maurer-Cartan expansion method we construct a procedure to obtain expanded higher-order Lie algebras. The expanded higher order Maurer-Cartan equations for the case $\mathcal{G}=V_{0}\oplus V_{1}$ are found. A dual formulation for the S-expansion multialgebra procedure is also considered. The expanded higher order Maurer Cartan equations are recovered from S-expansion formalism by choosing a special semigroup. This dual method could be useful in finding a generalization to the case of a generalized free differential algebra, which may be relevant for physical applications in, e.g., higher-spin gauge theories

The Applicability of Taylor’s Model to the Drilling of CFRP Using Uncoated WC-Co Tools: The Influence of Cutting Speed on Tool Wear

This work investigates the applicability of Taylor’s model on the drilling of CFRP using uncoated WC-Co tools, by assessing the influence of cutting speed (Vc) on tool wear. Two different resins, possessing low and high glass transition temperatures (Tg), and two different reinforcements, high strength and high modulus woven fabrics, were combined into three different systems. Flank wear rate gradient exhibited to be more reinforcement dependent, while the actual flank wear rate showed to be sensible also to the type of resin. In terms of tool life, all CFRP systems adjusted into a power-type tool life vs. cutting speed curve through the full range of cutting speeds (1,000 RPM to 18,000 RPM). Therefore, Taylor’s model can be applied to estimate the tool life in the drilling of CFRP using uncoated WC-Co tools with good accuracy

Detecting Successful Student Profiles At An Open University: The Case Of The UNED (Spain)

At present, one of the major issues and most interesting discussions within the European Higher Education Area is the rate of success in university-level study, and therefore the adaptation of todays university education system to societys requirements. Moreover, we have seen significant growth in distance education throughout recent decades, as this type of education takes on a stronger leadership role in countries that are experiencing severe economic crises. Because the National Distance Education University (UNED) is the most important distance university in Spain, and the Economics Degree program has been offered by the School of Economics and Business for the first time, we have attempted to find a correlation between variables which describe student characteristics (age, gender, employment status, manner of admission, and nationality) and success rates in order to determine the influence that these variables have and achieve a better understanding of student success rates

New Plaster Composite with Mineral Wool Fibres from CDW Recycling

Over the last decade the intense activity of the building sector has generated large quantities of construction and demolition waste (CDW). In particular, in Europe around 890 million tons of CDW is generated every year; however, only 50% of them are recycled. In Spain, over the last years 40 millions of tons of construction and demolition waste have been generated. On the other hand, since the implementation of the Technical Building Code regulation the use of mineral wools as building insulation materials has become a widespread solution in both rehabilitation and new construction works, and because of that, this kind of insulation waste is increasing. This research analyzes the potential of a new composite (gypsum and fiber waste) including several mineral wools waste into a plaster matrix. For this purpose, an experimental plan, characterizing the physical and mechanical behaviour as well as the Shore C hardness of the new composite, was elaborated fulfilling UNE Standards

Analysis of the applicability of the IEEE 2030.8 standard for testing a microgrid control system

To coordinate the operation of the different generating units, storage systems and loads belonging to a microgrid, typically a Microgrid Control System (MGCS) is needed. This MGCS defines the set points to be delivered to the controllable devices to guarantee the appropriate operation of the microgrid both from the technical and the economic perspectives. The MGCS must be able to operate the microgrid in islanded mode, grid-connected, and withstand the transitions between the two operatingmodes. Recently two international standards have been approved dealing with microgrid con-trollers, “IEEE 2030.7-2017 – IEEE Standard for the Specification of Microgrid Control-ler” and “IEEE 2030.8-2018 - IEEE Standard for the Testing of Microgrid Controllers”.The research leading to this publication has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 654113 via the Trans-national Access (TA) User Project 05.024-2018

Stabilizing carbon-lithium stars

We have explored in silico the potential energy surfaces of the C5Linn-6 (n = 5, 6, and 7) clusters using the Gradient Embedded Genetic Algorithm (GEGA) and other computational strategies. The most stable forms of C5Li5-- and C5Li6 are two carbon chains linked by two lithium atoms in a persistent seven membered ring capped by two Li atoms. The other Li atoms are arrayed on the edge of the seven membered ring. In contrast, the global minimum structure for C5Li7+ is a bicapped star of D5h symmetry. The molecular orbital analysis and computed magnetic field data suggest that electron delocalization, as well as the saturation of the apical positions of the five-membered carbon ring with lithium atoms in C5Li7+ plays a key role in the stabilization of the carbon-lithium star. In fact, the planar star sub-structure for the carbon ring are unstable without the apical caps. This is also what has been found for the Si analogues. The split of the Bindz in its σ- and π-contribution indicates that C5Li7+ is a p-aromatic and σ-nonaromatic system

Study of stress detection and proposal of stress-related features using commercial-off-the-shelf wrist wearables

This paper discusses the possibility of detecting personal stress making use of popular wearable devices available in the market. Different instruments found in the literature to measure stress-related features are reviewed, distinguishing between subjective tests and mechanisms supported by the analysis of physiological signals from clinical devices. Taking them as a reference, a solution to estimate stress based on the use of commercial-off-the-shelf wrist wearables and machine learning techniques is described. A mobile app was developed to induce stress in a uniform and systematic way. The app implements well-known stress inducers, such as the Paced Auditory Serial Addition Test, the Stroop Color-Word Interference Test, and a hyperventilation activity. Wearables are used to collect physiological data used to train classifiers that provide estimations on personal stress levels. The solution has been validated in an experiment involving 19 subjects, offering an average accuracy and F-measures close to 0.99 in an individual model and an accuracy and F-measure close to 0.85 in a global 2-level classifier model. Stress can be a worrying problem in different scenarios, such as in educational settings. Thus, the last part of the paper describes the proposal of a set of stress related indicators aimed to support the management of stress over time in such settings.Agencia Estatal de Investigación | Ref. TIN2016-80515-RUniversidade de Vig