921 research outputs found

    Electron-polaron--electron-polaron bound states in mass-gap graphene-like planar quantum electrodynamics: ss-wave bipolarons

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    A Lorentz invariant version of a mass-gap graphene-like planar quantum electrodynamics, the parity-preserving U(1)Ă—U(1)U(1)\times U(1) massive QED3_3, exhibits attractive interaction in low-energy electron-polaron--electron-polaron ss-wave scattering, favoring quasiparticles bound states, the ss-wave bipolarons.Comment: 6 pages, two figures, references adde

    Energy rating of a water pumping station using multivariate analysis

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    Among water management policies, the preservation and the saving of energy demand in water supply and treatment systems play key roles. When focusing on energy, the customary metric to determine the performance of water supply systems is linked to the definition of component-based energy indicators. This approach is unfit to account for interactions occurring among system elements or between the system and its environment. On the other hand, the development of information technology has led to the availability of increasing large amount of data, typically gathered from distributed sensor networks in so-called smart grids. In this context, data intensive methodologies address the possibility of using complex network modeling approaches, and advocate the issues related to the interpretation and analysis of large amount of data produced by smart sensor networks. In this perspective, the present work aims to use data intensive techniques in the energy analysis of a water management network. The purpose is to provide new metrics for the energy rating of the system and to be able to provide insights into the dynamics of its operations. The study applies neural network as a tool to predict energy demand, when using flowrate and vibration data as predictor variables

    Enseñanza de ELE a través de un sistema informático de análisis textual disponible en Internet

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    La creciente importancia de los corpus de textos digitalizados para la enseñanza de lenguas ha sido puesta de manifiesto por distintos autores a lo largo de los últimos años. Tribble y Jones (1990), Flowerdew (1993), Botley et al. (1996) y Sánchez (2000), entre otros, han subrayado la utilidad didáctica de los corpus textuales y de los sistemas informáticos que permiten consultarlos

    Let’s tweet again? Social networks and literature achievement in high school students

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    The availability of cheap Wi-Fi internet connections has encouraged schools to adopt Web 2.0 platforms for teaching, with the intention of stimulating students’ academic achievement and participation in school. Moreover, during the recent explosion of the SARS-CoV-2 crisis that forced many countries to close schools (as well as offices and factories), the widespread diffusion of these applications kept school systems going. Despite their widespread use as teaching tools, the effect of adopting Web 2.0 platforms on students’ performance has never been rigorously tested. We fill this gap in the literature by analyzing the impact of using Twitter as a teaching tool on high school students’ literature skills. Based on a large-scale, randomized controlled trial that involved 70 schools and about 1,500 students, we find that using Twitter to teach literature has an overall negative effect on students’ average achievement, reducing standardized test scores by about 25 percent of a standard deviation. The negative effect is stronger on students who usually perform better
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