The Eastward Enlargement of the Eurozone: Trade and FDI

Trade and FDI, Economic Integration

Influence of SiC reinforcement particles on the tribocorrosion behaviour of Al–SiCp FGMs in 0.05M NaCl solution

The main aim of this work was to study and understand the influence of SiC particles on the corrosion and tribocorrosion of Al-matrix composite materials. For that, Al–SiCp functionally graded composites were produced by centrifugal casting and different SiCp contents were achieved. Their mechanical properties were improved by age-hardening heat treatments. The tribocorrosion behaviour was studied in 0.05M NaCl solutions using a reciprocating motion tribometer involving an alumina ball sliding against the Al-based samples. Above critical SiC particles' content the matrix alloy surface was found to be protected against wear by SiC particles protruding from the surface. Below this threshold content, the SiC reinforcement was inefficient and the wear rate of the composite was the same as the non-reinforced alloy.The research team was financially supported by the Portuguese Foundation for Science and Technology (FCT-Portugal) under a PhD scholarship (SFRH/BD/27911/2006). The authors also thank Dr Edith Ariza (University of Minho) and Pierre Mettraux (EPFL) for SEM analysis

One-loop conformal anomaly in an implicit momentum space regularization framework

In this paper we consider matter fields in a gravitational background in order to compute the breaking of the conformal current at one-loop order. Standard perturbative calculations of conformal symmetry breaking expressed by the non-zero trace of the energy-momentum tensor have shown that some violating terms are regularization dependent, which may suggest the existence of spurious breaking terms in the anomaly. Therefore, we perform the calculation in a momentum space regularization framework in which regularization dependent terms are judiciously parametrized. We compare our results with those obtained in the literature and conclude that there is an unavoidable arbitrariness in the anomalous term $\Box R$.Comment: in European Physical Journal C, 201

Dynamical Structure of the Molecular Interstellar Medium in an Extremely Bright, Multiply Lensed z ≃ 3 Submillimeter Galaxy Discovered with Herschel

We report the detection of CO(J = 5 → 4), CO(J = 3 → 2), and CO(J = 1 → 0) emission in the strongly lensed, Herschel/SPIRE-selected submillimeter galaxy (SMG) HERMES J105751.1+573027 at z = 2.9574 ± 0.0001, using the Plateau de Bure Interferometer, the Combined Array for Research in Millimeter-wave Astronomy, and the Green Bank Telescope. The observations spatially resolve the molecular gas into four lensed images with a maximum separation of ~9" and reveal the internal gas dynamics in this system. We derive lensing-corrected CO line luminosities of L'_(CO(1-0)) = (4.17 ± 0.41), L'_(CO(3-2)) = (3.96 ± 0.20), and L'_(CO(5-4)) = (3.45 ± 0.20) × 10^(10) (μL/10.9)^(–1) K km s^(–1) pc^2, corresponding to luminosity ratios of r_(31) = 0.95 ± 0.10, r_(53) = 0.87 ± 0.06, and r_(51) = 0.83 ± 0.09. This suggests a total molecular gas mass of M_(gas) = 3.3×10^(10) (α_(CO)/0.8) (μ_L/10.9)^(–1) M_☉. The gas mass, gas mass fraction, gas depletion timescale, star formation efficiency, and specific star formation rate are typical for an SMG. The velocity structure of the gas reservoir suggests that the brightest two lensed images are dynamically resolved projections of the same dust-obscured region in the galaxy that are kinematically offset from the unresolved fainter images. The resolved kinematics appear consistent with the complex velocity structure observed in major, "wet" (i.e., gas-rich) mergers. Major mergers are commonly observed in SMGs and are likely to be responsible for fueling their intense starbursts at high gas consumption rates. This study demonstrates the level of detail to which galaxies in the early universe can be studied by utilizing the increase in effective spatial resolution and sensitivity provided by gravitational lensing

Close encounters involving RAVE stars beyond the 47 Tucanae tidal radius

The most accurate 6D phase-space information from the Radial Velocity Experiment (RAVE) was used to integrate the orbits of 105 stars around the galactic globular cluster 47 Tucanae, to look for close encounters between them in the past, with a minimum distance approach less than the cluster tidal radius. The stars are currently over the distance range 3.0 kpc $<$ d $<$ 5.5 kpc. Using the uncertainties in the current position and velocity vector for both, star and cluster, 105 pairs of star-cluster orbits were generated in a Monte Carlo numerical scheme, integrated over 2 Gyr and considering an axisymmetric and non-axisymmetric Milky-Way-like Galactic potential, respectively. In this scheme, we identified 20 potential cluster members that had close encounters with the globular cluster 47 Tucanae, all of which have a relative velocity distribution (V$_{rel}$) less than 200 km s$^{-1}$ at the minimum distance approach. Among these potential members, 9 had close encounters with the cluster with velocities less than the escape velocity of 47 Tucanae, therefore a scenario of tidal stripping seems likely. These stars have been classified with a 93\% confidence level, leading to the identification of extratidal cluster stars. For the other 11 stars, V$_{rel}$ exceeds the escape velocity of the cluster, therefore they were likely ejected or are unassociated interlopers.Comment: 10 pages, 6 figures, 2 table, Accepted for publication in MNRA

SAMplus: adaptive optics at optical wavelengths for SOAR

Adaptive Optics (AO) is an innovative technique that substantially improves the optical performance of ground-based telescopes. The SOAR Adaptive Module (SAM) is a laser-assisted AO instrument, designed to compensate ground-layer atmospheric turbulence in near-IR and visible wavelengths over a large Field of View. Here we detail our proposal to upgrade SAM, dubbed SAMplus, that is focused on enhancing its performance in visible wavelengths and increasing the instrument reliability. As an illustration, for a seeing of 0.62 arcsec at 500 nm and a typical turbulence profile, current SAM improves the PSF FWHM to 0.40 arcsec, and with the upgrade we expect to deliver images with a FWHM of $\approx0.34$ arcsec -- up to 0.23 arcsec FWHM PSF under good seeing conditions. Such capabilities will be fully integrated with the latest SAM instruments, putting SOAR in an unique position as observatory facility.Comment: To appear in Proc. SPIE 10703 (Ground-based and Airborne Instrumentation for Astronomy VII; SPIEastro18