1,721,019 research outputs found
A sinc-based approach for the solution of differential transport problems with periodic boundary conditions
No full textFamilial acute dystonic-dyskinetic syndrome with dominant inheritance after use of antidopaminergic antiemetic drugs
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Note: Improvement of the 3w thermal conductivity measurement technique for its application at the nanoscale
No full textConventional techniques for thermal conductivity measurements can lead to unreliable results when applied to nanostructures because heaters and temperature sensors needed for the measurement cannot have a negligible size and therefore perturb the result. In this paper, we focus on the 3w technique, applied to the evaluation of the thermal conductivity of suspended silicon nanoribbons. We introduce a numerical approach based on the finite element solution of the electrical and thermal transport equations and compare its results with those of conventional methods. We show that with our approach we achieve an excellent fit of the experimental data, in particular, for nanostructured materials
Thermal Conductivity Reduction in Rough Silicon Nanomembranes
Full text linkNanostructured silicon is a promising material for thermoelectric conversion because the thermal conductivity in silicon nanostructures can be strongly reduced with respect to that of bulk materials. We present thermal conductivity measurements, performed with the 3ω technique, of suspended monocrystalline silicon thin films (nanomembranes or nanoribbons) with smooth and rough surfaces. We find evidence for a significant effect of surface roughness on phonon propagation: the measured thermal conductivity for the rough structures is well below that predicted by theoretical models which take into account diffusive scattering on the nanostructure walls. Conversely, the electrical conductivity appears to be substantially unaffected by surface roughness: the measured resistance of smooth and rough nanostructures is comparable, if we take into account the geometrical factors. Nanomembranes are more easily integrable in large area devices with respect to nanowires and are mechanically stronger and able to handle much larger electrical currents, thus enabling the fabrication of thermoelectric devices that can supply higher power levels with respect to existing solutions. © 2002-2012 IEEE
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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