Preface "Nonlinear processes in oceanic and atmospheric flows"

Nonlinear phenomena are essential ingredients in many oceanic and atmospheric processes, and successful understanding of them benefits from multidisciplinary collaboration between oceanographers, meteorologists, physicists and mathematicians. The present Special Issue on ``Nonlinear Processes in Oceanic and Atmospheric Flows'' contains selected contributions from attendants to the workshop which, in the above spirit, was held in Castro Urdiales, Spain, in July 2008. Here we summarize the Special Issue contributions, which include papers on the characterization of ocean transport in the Lagrangian and in the Eulerian frameworks, generation and variability of jets and waves, interactions of fluid flow with plankton dynamics or heavy drops, scaling in meteorological fields, and statistical properties of El Ni\~no Southern Oscillation.Comment: This is the introductory article to a Special Issue on "Nonlinear Processes in Oceanic and Atmospheric Flows'', published in the journal Nonlinear Processes in Geophysics, where the different contributions are summarized. The Special Issue itself is freely available from http://www.nonlin-processes-geophys.net/special_issue103.htm

First ozone reanalysis on Mars using SPICAM data

To further our understanding of important photochemical processes in the Martian atmosphere, a synthesis can be used to investigate the temporal and spatial agreement between model and observations and determine any possible causes of identified differences. In this study [1], we have assimilated, for the first time, total ozone into a Mars Global Circulation model (GCM) to study the ozone cycle

TeV cosmic-ray proton and helium spectra in the myriad model

Recent measurements of cosmic ray proton and helium spectra show a hardening above a few hundreds of GeV. This excess is hard to understand in the framework of the conventional models of Galactic cosmic ray production and propagation. We propose here to explain this anomaly by the presence of local sources (myriad model). Cosmic ray propagation is described as a diffusion process taking place inside a two-zone magnetic halo. We calculate the proton and helium fluxes at the Earth between 50 GeV and 100 TeV. Improving over a similar analysis, we consistently derive these fluxes by taking into account both local and remote sources for which a unique injection rate is assumed. We find cosmic ray propagation parameters compatible with B/C measurements and for which the proton and helium spectra remarkably agree with the PAMELA and CREAM measurements over four decades in energy.Comment: 5 pages, 3 figure

Experimental verification of reciprocity relations in quantum thermoelectric transport

Symmetry relations are manifestations of fundamental principles and constitute cornerstones of modern physics. An example are the Onsager relations between coefficients connecting thermodynamic fluxes and forces, central to transport theory and experiments. Initially formulated for classical systems, these reciprocity relations are also fulfilled in quantum conductors. Surprisingly, novel relations have been predicted specifically for thermoelectric transport. However, whereas these thermoelectric reciprocity relations have to date not been verified, they have been predicted to be sensitive to inelastic scattering, always present at finite temperature. The question whether the relations exist in practice is important for thermoelectricity: whereas their existence may simplify the theory of complex thermoelectric materials, their absence has been shown to enable, in principle, higher thermoelectric energy conversion efficiency for a given material quality. Here we experimentally verify the thermoelectric reciprocity relations in a four-terminal mesoscopic device where each terminal can be electrically and thermally biased, individually. The linear response thermoelectric coefficients are found to be symmetric under simultaneous reversal of magnetic field and exchange of injection and emission contacts. Intriguingly, we also observe the breakdown of the reciprocity relations as a function of increasing thermal bias. Our measurements thus clearly establish the existence of the thermoelectric reciprocity relations, as well as the possibility to control their breakdown with the potential to enhance thermoelectric performanceComment: 7 pages, 5 figure

La evaluación de la actividad científica en Ciencias Sociales y Humanidades

110 p.La Cátedra Miguel Sánchez-Mazas (CSM) fue creada en 1999 por la Junta de Gobierno de la Universidad del País Vasco / Euskal Herriko Unibertsitatea (UPV/EHU), con el objetivo de promover y fortalecer los vínculos entre la Universidad y la Sociedad. La CSM tiene por finalidad desarrollar actividades de extensión universitaria y de investigación asociadas a los temas de Ciencia, Tecnología, Innovación y Sociedad. Sus ámbitos de actuación se estructuran en tres campos: (i) organización de seminarios, encuentros y otras actividades en las que se promueve la difusión de una perspectiva social de la Ciencia y la Tecnología entre diversos actores sociales; (ii) actividades de publicación sobre estos mismos temas; y (iii) actividades de investigación concernientes al vector ciencia-tecnología-innovación. Con la Serie: “Estudios en Ciencia, Tecnología e Innovación”, la CSM tiene el propósito de difundir los resultados de diversas investigaciones que problematizan temas vinculados a la ciencia, la tecnología y la innovación en la emergencia de la sociedad del conocimiento. Se trata de un esfuerzo editorial por difundir una perspectiva social del conocimiento desde distintos enfoques de investigación y diversas perspectivas disciplinarias. I Índice: - Presentación. El desafío de evaluar la investigación en las Ciencias Sociales y las Humanidades (Andoni Ibarra, Javier Castro, Julieta Barrenechea). - Luces y sombras en la evaluacio ón de la investigación en Ciencias Sociales y Humanidades(Elías Sanz-Casado, María Luisa Lascurain, Isabel Iribarren). - ¿Hacia una evaluación métrica de la investigación en las Humanidades y en las Ciencias Sociales? (Llui ís Rovira). - Evaluación de la investigación en Ciencias Sociales y Humanas: algunas consideraciones desde la experiencia del Grupo de Estudios de la Actividad Científica (Jesús Rey Rocha, M. José Martín Sempere). - Indicadores de actividad científica en Ciencias Sociales y Humanidades: Hacia un modelo de evaluación integral basado en patrones disciplinarios de investigación (Javier Castro, Julieta Barrenechea, Andoni Ibarra). - Acta del Taller Indicadores para la evaluación de la actividad de investigación en Ciencias Sociales y Humanidades

Evolución histórica de la investigación agraria en España

La evolución del sistema de investigación agraria en España, tras distintas acciones gubernamentales, ha generado una situación caracterizada por un mayor tamaño, con un papel más relevante para el sector privado y la Universidad. Así, el sector privado reaccionó positivamenfe ante el impulso gubernamental aumentando su esfuerzo innovador a través de una mayor inversión en I+D. Se concluye indicando que el proceso de globalización de la investigación puede traer consigo importantes ventajas siempre y cuando se instauren los mecanismos reguladores y se estimulen los flujos de I+D.The evolution of the Agricultural Research System in Spain, after different government actions had led to a situation noted for an increase in size with the private and higher education subsector playing a highly relevant role. Thus, the private sector reacted positively to the government push, increasing its agricultural R&D expenditure and expanding innovative efforts. We conclude that globalization offers significant opportunities for technological gain whenever regulatory mechanisms and stimulating environment that enables cross-border R&D flows are to be established

Entanglement of Dirac fields in an expanding spacetime

We study the entanglement generated between Dirac modes in a 2-dimensional conformally flat Robertson-Walker universe. We find radical qualitative differences between the bosonic and fermionic entanglement generated by the expansion. The particular way in which fermionic fields get entangled encodes more information about the underlying space-time than the bosonic case, thereby allowing us to reconstruct the parameters of the history of the expansion. This highlights the importance of bosonic/fermionic statistics to account for relativistic effects on the entanglement of quantum fields.Comment: revtex4, 7 figures, I.F. previously published as Fuentes-Guridi and Fuentes-Schuller. Journal reference update

La política tecnológica, una via de ajuste positivo a la crisis

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Robust plasmon waveguides in strongly-interacting nanowire arrays

Arrays of parallel metallic nanowires are shown to provide a tunable, robust, and versatile platform for plasmon interconnects, including high-curvature turns with minimum signal loss. The proposed guiding mechanism relies on gap plasmons existing in the region between adjacent nanowires of dimers and multi-wire arrays. We focus on square and circular silver nanowires in silica, for which excellent agreement between both boundary element method and multiple multipolar expansion calculations is obtained. Our work provides the tools for designing plasmon-based interconnects and achieving high degree of integration with minimum cross talk between adjacent plasmon guides.Comment: 4 pages, 5 figure