4,870 research outputs found

    Lectura crítica, una herramienta para mejorar el aprendizaje de las Ciencias

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    El pensamiento crítico es un aspecto crucial que todo ciudadano necesita para poder participar en una sociedad democrática y plural. La lectura, a clase de ciencias de artículos y textos de diferentes fuentes, así como su comprensión crítica, puede ayudar a los estudiantes a desarrollar esta capacidad y potenciar la participación en el discurso social en relación a temáticas científicas que los afectan directamente. Nuestro estudio, que se enmarca dentro del grupo de investigación de la UAB LIEC, se centra en promover la lectura crítica de textos de contenido científico de diferentes fuentes, y analizar como esta lectura favorece un aprendizaje de las ciencias relevante socialmente. En esta comunicación se presenta los resultados de aplicar una de estas actividades realizada a partir de la lectura crítica de un artículo de prensa sobre grafitis

    ¿Con qué criterios valora el profesorado la aplicación de un proyecto de innovación de física en contexto?

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    En este trabajo presentamos algunos de los criterios con los que el profesorado valora la aplicación de un proyecto de física en contexto, analizando su contribución al desarrollo de las capacidades recogidas en las finalidades y los objetivos del bachillerato y buscando identificar los puntos fuertes y los aspectos que habría que revisar para orientar los posibles cambios a introducir para su mejora. Los resultados muestran, por una parte, que el proyecto interesa y se adapta al currículum y a las PAAU y es rico en actividades de enseñanza-aprendizaje, aunque no siempre se saben utilizar de manera eficiente y que, por otra, genera un proceso de formación en el profesorado que se valora como muy positivo y que comporta cambios profesionales más allá de la aplicación del proyecto

    A Methodology for the Design of Robotic Hands with Multiple Fingers

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    This paper presents a methodology that has been applied for a design process of anthropomorphic hands with multiple fingers. Biomechanical characteristics of human hand have been analysed so that ergonomic and anthropometric aspects have been used as fundamental references for obtaining grasping mechanisms. A kinematic analysis has been proposed to define the requirements for designing grasping functions. Selection of materials and actuators has been discussed too. This topic has been based on previous experiences with prototypes that have been developed at the Laboratory of Robotics and Mechatronics (LARM) of the University of Cassino. An example of the application of the proposed method has been presented for the design of a first prototype of LARM Hand

    PSS32 Predictors of Biologic Treatment in Psoriasis Population

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    Kadanoff-Baym approach to time-dependent quantum transport in AC and DC fields

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    We have developed a method based on the embedded Kadanoff-Baym equations to study the time evolution of open and inhomogeneous systems. The equation of motion for the Green's function on the Keldysh contour is solved using different conserving many-body approximations for the self-energy. Our formulation incorporates basic conservation laws, such as particle conservation, and includes both initial correlations and initial embedding effects, without restrictions on the time-dependence of the external driving field. We present results for the time-dependent density, current and dipole moment for a correlated tight binding chain connected to one-dimensional non-interacting leads exposed to DC and AC biases of various forms. We find that the self-consistent 2B and GW approximations are in extremely good agreement with each other at all times, for the long-range interactions that we consider. In the DC case we show that the oscillations in the transients can be understood from interchain and lead-chain transitions in the system and find that the dominant frequency corresponds to the HOMO-LUMO transition of the central wire. For AC biases with odd inversion symmetry odd harmonics to high harmonic order in the driving frequency are observed in the dipole moment, whereas for asymmetric applied bias also even harmonics have considerable intensity. In both cases we find that the HOMO-LUMO transition strongly mixes with the harmonics leading to harmonic peaks with enhanced intensity at the HOMO-LUMO transition energy.Comment: 16 pages, 9 figures. Submitted at "Progress in Nonequilibrium Green's Functions IV" conferenc

    Ceramica punica dal sito rurale di Truncu 'e Molas (Terralba, Sardegna)

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    A Nonperturbative Eliasson's Reducibility Theorem

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    This paper is concerned with discrete, one-dimensional Schr\"odinger operators with real analytic potentials and one Diophantine frequency. Using localization and duality we show that almost every point in the spectrum admits a quasi-periodic Bloch wave if the potential is smaller than a certain constant which does not depend on the precise Diophantine conditions. The associated first-order system, a quasi-periodic skew-product, is shown to be reducible for almost all values of the energy. This is a partial nonperturbative generalization of a reducibility theorem by Eliasson. We also extend nonperturbatively the genericity of Cantor spectrum for these Schr\"odinger operators. Finally we prove that in our setting, Cantor spectrum implies the existence of a GδG_\delta-set of energies whose Schr\"odinger cocycle is not reducible to constant coefficients

    Finite elements and the discrete variable representation in nonequilibrium Green's function calculations. Atomic and molecular models

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    In this contribution, we discuss the finite-element discrete variable representation (FE-DVR) of the nonequilibrium Green's function and its implications on the description of strongly inhomogeneous quantum systems. In detail, we show that the complementary features of FEs and the DVR allows for a notably more efficient solution of the two-time Schwinger/Keldysh/Kadanoff-Baym equations compared to a general basis approach. Particularly, the use of the FE-DVR leads to an essential speedup in computing the self-energies. As atomic and molecular examples we consider the He atom and the linear version of H3+_3^+ in one spatial dimension. For these closed-shell models we, in Hartree-Fock and second Born approximation, compute the ground-state properties and compare with the exact findings obtained from the solution of the few-particle time-dependent Schr\"odinger equation.Comment: 12 pages, 3 figures, submitted as proceedings of conference "PNGF IV
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