On the evolution of flow topology in turbulent Rayleigh-Bénard convection

Copyright 2016 AIP Publishing. This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing.Small-scale dynamics is the spirit of turbulence physics. It implicates many attributes of flow topology evolution, coherent structures, hairpin vorticity dynamics, and mechanism of the kinetic energy cascade. In this work, several dynamical aspects of the small-scale motions have been numerically studied in a framework of Rayleigh-Benard convection (RBC). To do so, direct numerical simulations have been carried out at two Rayleigh numbers Ra = 10(8) and 10(10), inside an air-filled rectangular cell of aspect ratio unity and pi span-wise open-ended distance. As a main feature, the average rate of the invariants of the velocity gradient tensor (Q(G), R-G) has displayed the so-calledPeer ReviewedPostprint (author's final draft

Infrared Spectroscopy of Molecular Supernova Remnants

We present Infrared Space Observatory spectroscopy of sites in the supernova remnants W28, W44, and 3C391, where blast waves are impacting molecular clouds. Atomic fine-structure lines were detected from C, N, O, Si, P, and Fe. The S(3) and S(9) lines of H2 were detected for all three remnants. The observations require both shocks into gas with moderate (~ 100 /cm3) and high (~10,000 /cm3) pre-shock densities, with the moderate density shocks producing the ionic lines and the high density shock producing the molecular lines. No single shock model can account for all of the observed lines, even at the order of magnitude level. We find that the principal coolants of radiative supernova shocks in moderate-density gas are the far-infrared continuum from dust grains surviving the shock, followed by collisionally-excited [O I] 63.2 and [Si II] 34.8 micron lines. The principal coolant of the high-density shocks is collisionally-excited H2 rotational and ro-vibrational line emission. We systematically examine the ground-state fine structure of all cosmically abundant elements, to explain the presence or lack of all atomic fine lines in our spectra in terms of the atomic structure, interstellar abundances, and a moderate-density, partially-ionized plasma. The [P II] line at 60.6 microns is the first known astronomical detection. There is one bright unidentified line in our spectra, at 74.26 microns. The presence of bright [Si II] and [Fe II] lines requires partial destruction of the dust. The required gas-phase abundance of Fe suggests 15-30% of the Fe-bearing grains were destroyed. The infrared continuum brightness requires ~1 Msun of dust survives the shock, suggesting about 1/3 of the dust mass was destroyed, in agreement with the depletion estimate and with theoretical models for dust destruction.Comment: 40 pages; 10 figures; accepted by ApJ July 11, 200

New subgrid-scale models for large-eddy simulation of Rayleigh-Bénard convection

Published under licence in Journal of Physics: Conference Series by IOP Publishing Ltd. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.At the crossroad between flow topology analysis and the theory of turbulence, a new eddy-viscosity model for Large-eddy simulation has been recently proposed by Trias et al.[PoF, 27, 065103 (2015)]. The S3PQR-model has the proper cubic near-wall behaviour and no intrinsic limitations for statistically inhomogeneous flows. In this work, the new model has been tested for an air turbulent Rayleigh-Benard convection in a rectangular cell of aspect ratio unity and n span-wise open-ended distance. To do so, direct numerical simulation has been carried out at two Rayleigh numbers Ra = 108 and 1010, to assess the model performance and investigate a priori the effect of the turbulent Prandtl number. Using an approximate formula based on the Taylor series expansion, the turbulent Prandtl number has been calculated and revealed a constant and Ra-independent value across the bulk region equals to 0.55. It is found that the turbulent components of eddy-viscosity and eddy-diffusivity are positively prevalent to maintain a turbulent wind essentially driven by the mean buoyant force at the sidewalls. On the other hand, the new eddy-viscosity model is preliminary tested for the case of Ra = 108 and showed overestimation of heat flux within the boundary layer but fairly good prediction of turbulent kinetics at this moderate turbulent flow.Peer ReviewedPostprint (published version

Quinoidization of regioregular oligo(THIENO[3,4-b]THIOPHENE)s

Caracterización de oligotiofenosUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Posterior Arthroscopic Subtalar Arthrodesis: Clinical and Radiologic Review of 19 Cases

Arthroscopic subtalar arthrodesis has recently gained popularity in the treatment of primary subtalar or post-traumatic arthritis, coalition, or inflammatory diseases with subtalar arthritis. The present study reports the clinical and radiologic results of 19 patients (19 feet) who underwent posterior arthroscopic subtalar arthrodesis using 2 posterior portals. A total of 19 posterior arthroscopic subtalar arthrodeses (minimum follow-up of 24 months) performed without a bone graft and with 2 parallel screws were prospectively evaluated. The fusion rate was 94% (mean time to fusion 9.8 weeks). Modified American Orthopaedic Foot and Ankle Society ankle-hindfoot scale score (maximum 94 points) improved significantly from 43 to 80 points and the visual analog scale for pain score improved from 7.6 to 1.2. The 12-item short-form physical and mental scores at the last follow-up point were 52.5 and 56.4, respectively. One (5.3%) patient underwent open repeat fusion for nonunion, 2 (10.5%) patients required a second procedure for implant removal, and 1 (5.3%) experienced reversible neuropraxia. In conclusion, posterior arthroscopic subtalar arthrodesis is a safe technique with a good union rate and a small number of complications in patients with no or very little hindfoot deformity.info:eu-repo/semantics/publishedVersio

Leishmaniosis felina a propósito de un caso clínico : ¿Nos olvidamos de que existe?

En este trabajo se describe un caso de leishmaniosis felina con sintomatología cutánea y sistémica, así como el protocolo diagnóstico realizado. También se exponen las razones por las cuales se trata de una enfermedad que debemos tenerla en cuenta en nuestra práctica diaria y, por lo tanto, en nuestros diagnósticos diferenciales

Near-infrared spectroscopy of the Blue Compact Dwarf galaxy Markarian 59

We present near-infrared (NIR) spectroscopic observations of the blue compact dwarf (BCD) galaxy Mrk 59, obtained with the TripleSpec spectrograph mounted on the 3.5m APO telescope. The NIR spectrum of Mrk 59, which covers the 0.90 - 2.40 micron wavelength range, shows atomic hydrogen, molecular hydrogen, helium, sulfur and iron emission lines. The NIR data have been supplemented by a SDSS optical spectrum. We found extinction in the BCD to be low [A(V)=0.24 mag] and to be the same in both the optical and NIR ranges. The NIR light does not reveal hidden star formation. The H2 emission comes from dense clumps and the H2 vibrational emission line intensities can be accounted for by photon excitation. No shock excitation is needed. A CLOUDY photoinization model of Mrk 59 reproduces well the observed optical and NIR emission line fluxes. There is no need to invoke sources of ionization other than stellar radiation.The [FeII] 1.257 and 1.643 micron emission lines, often used as supernova shock indicators in low-excitation high-metallicity starburst galaxies, cannot play such a role in high-excitation low-metallicity HII regions such as Mrk 59.Comment: 23 pages, 3 figures, accepted for publication in the Astrophysical Journa

A Compendium of Far-Infrared Line and Continuum Emission for 227 Galaxies Observed by the Infrared Space Observatory

Far-infrared line and continuum fluxes are presented for a sample of 227 galaxies observed with the Long Wavelength Spectrometer on the Infrared Space Observatory. The galaxy sample includes normal star-forming systems, starbursts, and active galactic nuclei covering a wide range of colors and morphologies. The dataset spans some 1300 line fluxes, 600 line upper limits, and 800 continuum fluxes. Several fine structure emission lines are detected that arise in either photodissociation or HII regions: [OIII]52um, [NIII]57um, [OI]63um, [OIII]88um, [NII]122um, [OI]145um, and [CII]158um. Molecular lines such as OH at 53um, 79um, 84um, 119um, and 163um, and H2O at 58um, 66um, 75um, 101um, and 108um are also detected in some galaxies. In addition to those lines emitted by the target galaxies, serendipitous detections of Milky Way [CII]158um and an unidentified line near 74um in NGC1068 are also reported. Finally, continuum fluxes at 52um, 57um, 63um, 88um, 122um, 145um, 158um, and 170um are derived for a subset of galaxies in which the far-infrared emission is contained within the ~75" ISO LWS beam. The statistics of this large database of continuum and line fluxes, including trends in line ratios with the far-infrared color and infrared-to-optical ratio, are explored.Comment: Accepted for publication in the Astrophysical Journal Supplement Serie