Architecting the cyberinfrastructure for National Science Foundation Ocean Observatories Initiative (OOI)

The NSF Ocean Observatories Initiative (OOI) is a networked ocean research observatory with arrays of instrumented water column moorings and buoys, profilers, gliders and autonomous underwater vehicles (AUV) within different open ocean and coastal regions. OOI infrastructure also includes a cabled array of instrumented seafloor platforms and water column moorings on the Juan de Fuca tectonic plate. This networked system of instruments, moored and mobile platforms, and arrays will provide ocean scientists, educators and the public the means to collect sustained, time-series data sets that will enable examination of complex, interlinked physical, chemical, biological, and geological processes operating throughout the coastal regions and open ocean. The seven arrays built and deployed during construction support the core set of OOI multidisciplinary scientific instruments that are integrated into a networked software system that will process, distribute, and store all acquired data. The OOI has been built with an expectation of operation for 25 years.Peer Reviewe

La venta y el consumo de carne, según las ordenanzas locales de Andalucía

Se realiza un estudio de un conjunto de Ordenanzas de distintas localidades de Andalucía, redactadas a finales del siglo XV y siglo XVI, con objeto de analizar los contenidos referentes a la comercialización y venta de la carne. Se apreciaba, en la mayor parte de esas ordenanzas, una preocupación clara por el abastecimiento del producto cárnico a toda la población, por lo que se dictaron normas que regulaban la entrada y salida de ganado de las distintas dehesas. Igualmente se tenía un interés especial para que las medidas higiénicas en los mataderos y carnicerías fueran las adecuadas y que en la venta de la carne y sus productos no se produjesen fraudes, que eran rígidamente perseguidos

The Andreev states of a superconducting quantum dot: mean field vs exact numerical results

We analyze the spectral density of a single level quantum dot coupled to superconducting leads focusing on the Andreev states appearing within the superconducting gap. We use two complementary approaches: the numerical renormalization group and the Hartree-Fock approximation. Our results show the existence of up to four bound states within the gap when the ground state is a spin doublet (\pi\ phase). Furthermore the results demonstrate the reliability of the mean field description within this phase. This is understood from a complete correspondence that can be established between the exact and the mean field quasiparticle excitation spectrumComment: 6 pages, 5 figure

Non-equilibrium dynamics of Andreev states in the Kondo regime

The transport properties of a quantum dot coupled to superconducting leads are analyzed. It is shown that the quasiparticle current in the Kondo regime is determined by the non-equilibrium dynamics of subgap states (Andreev states) under an applied voltage. The current at low bias is suppressed exponentially for decreasing Kondo temperature in agreement with recent experiments. We also predict novel interference effects due to multiple Landau-Zener transitions between Andreev states.Comment: Revtex4, 4 pages, 4 figure

Non adiabatic features of electron pumping through a quantum dot in the Kondo regime

We investigate the behavior of the dc electronic current, Jdc, in an interacting quantum dot driven by two ac local potentials oscillating with a frequency, Omega0, and a phase-lag, phi. We provide analytical functions to describe the fingerprints of the Coulomb interaction in an experimental Jdc vs phi characteristic curve. We show that the Kondo resonance reduces at low temperatures the frequency range for the linear behavior of Jdc in Omega0 to take place and determines the evolution of the dc-current as the temperature increases.Comment: 8 pages, 7 figure

Microscopic theory of the proximity effect in superconductor-graphene nanostructures

We present a theoretical analysis of the proximity effect at a graphene-superconductor interface. We use a tight-binding model for the electronic states in this system which allows to describe the interface at the microscopic level. Two different interface models are proposed: one in which the superconductor induces a finite pairing in the graphene regions underneath, thus maintaining the honeycomb structure at the interface and one that assumes that the graphene layer is directly coupled to a bulk superconducting electrode. We show that properties like the Andreev reflection probability and its channel decomposition depend critically on the model used to describe the interface. We also study the proximity effect on the local density of states on the graphene. For finite layers we analyze the induced minigap and how it is reduced when the length of the layer increases. Results for the local density of states profiles for finite and semi-infinite layers are presented.Comment: 9 pages, 7 figures, submitted to Phys. Rev.

Interpolative method for transport properties of quantum dots in the Kondo regime

We present an interpolative method for describing coherent transport through an interacting quantum dot. The idea of the method is to construct an approximate electron self-energy which becomes exact both in the limits of weak and strong coupling to the leads. The validity of the approximation is first checked for the case of a single (spin-degenerate) dot level. A generalization to the multilevel case is then discussed. We present results both for the density of states and the temperature dependent linear conductance showing the transition from the Kondo to the Coulomb blockade regime.Comment: 8 pages, 3 figures, includes lamuphys.sty, submitted to the Proceedings of the XVI Sitges Conference on Statistical Mechanic

Los espectros de los desaparecidos : pasajes entre compromiso político y visión literaria en los últimos cuentos de Cortázar

The uneasy relationship between literary conception and political commitment is a recurrent subject of meditation in Julio Cortázar’s writings and amongst his critics. The debate revolves around two main considerations: firstly, to what extent and how (if so) Cortázar managed to reconcile his aesthetic ideas with his ethical views; secondly, whether this reconciliation attempt meant a paradigm change in his poetics or not. These deliberations reached a culmination point and appeared in its most illuminating form in Cortázar’s last three short story compilations; particularly in those stories where the need for political and ethical engagement articulates with the fantastic, one of the predominant narrative modes in his poetics. This article examines four of these short stories as prime examples of Cortázar’s attempt to reconcile the individual metaphysical search typical of his early writings with his later political pledges. The hypothesis is that these stories actually represent an excellent instance of how he was able to achieve a harmonic symbiosis between his poetics and his politics in the last years of his life