The Ageing European Workforce

One may postulate that increased longevity has automatically translated into longer working lives, but that this is not necessarily the case in Europe. For example, the French have amongst the highest longevity in Europe, yet they retire much earlier than many of their fellow Europeans

Role of electrostatic forces in cluster formation in a dry ionomer

This simulation study investigates the dependence of the structure of dry Nafion$^{\tiny\textregistered}$-like ionomers on the electrostatic interactions between the components of the molecules. In order to speed equilibration, a procedure was adopted which involved detaching the side chains from the backbone and cutting the backbone into segments, and then reassembling the macromolecule by means of a strong imposed attractive force between the cut ends of the backbone, and between the non-ionic ends of the side chains and the midpoints of the backbone segments. Parameters varied in this study include the dielectric constant, the free volume, side-chain length, and strength of head-group interactions. A series of coarse-grained mesoscale simulations shows the morphlogy to depend sensitively on the ratio of the strength of the dipole-dipole interactions between the side-chain acidic end groups to the strength of the other electrostatic components of the Hamiltonian. Examples of the two differing morphologies proposed by Gierke and by Gebel emerge from our simulations.Comment: 39 pages, 18 figures, accepted for publicatio

The metallicity and elemental abundance maps of kinematically atypical galaxies for constraining minor merger and accretion histories

© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.Explaining the internal distribution and motions of stars and gas in galaxies is a key aspect in understanding their evolution. In previous work we identified five well-resolved galaxies with atypical kinematics from a cosmological simulation; two had kinematically distinct cores (KDCs), and three had counter-rotating gas and stars (CRGD). In this paper, we show that (i) the KDC galaxies have flattening of stellar [O/Fe] at large galactocentric radii due to the minor mergers that gave rise to the KDCs, and (ii) the CRGD galaxies have an abrupt transition in the gas metallicity maps, from high metallicity in the centre to very low metallicity further out. These galaxies are embedded in dark matter filaments where there is a ready supply of near-pristine gas to cause this effect. The non-linear increase in gas metallicity is also seen in the radial profiles, but when the metallicity gradients are measured, the difference is buried in the scatter of the relation. We also find that all five galaxies are fairly compact, with small effective radii given their stellar masses. This is because they have not experienced major mergers that kinematically heat the stars, and would have destroyed their unusual kinematics. In order to detect these signatures of minor mergers or accretion, the galaxy scaling relations or radial metallicity profiles are not enough, and it is necessary to obtain the two-dimensional maps with integral field spectroscopy observations.Peer reviewe

The nature of X-ray spectral variability in Seyfert Galaxies

We use a model-independent technique to investigate the nature of the 2-15 keV X-ray spectral variability in four Seyfert galaxies and distinguish between spectral pivoting and the two-component model for spectral variability. Our analysis reveals conclusively that the softening of the X-ray continuum with increasing flux in MCG -6-30-15 and NGC 3516 is a result of summing two spectral components: a soft varying component (SVC) with spectral shape independent of flux and a constant hard component (HCC). In contrast, the spectral variability in NGC 4051 can be well described by simple pivoting of one component, together with an additional hard constant component. The spectral variability model for NGC 5506 is ambiguous, due to the smaller range of fluxes sampled by the data. We investigate the shape of the hard spectral component in MCG -6-30-15 and find that it appears similar to a pure reflection spectrum, but requires a large reflected fraction (R>3). We briefly discuss physical interpretations of the different modes of spectral variability.Comment: Accepted for publication in MNRAS letter

Lightweight piston architecture

The invention is an improvement in a lightweight carbon-carbon composite piston, the improvement uses near-net shape knitted or warp-interlock preforms to improve the structural qualities of the piston. In its preferred embodiment, a one piece, tubular, closed-ended, knitted preform (a sock) of carbon fibers embedded within the matrix of the piston structure forms the crown, side wall, skirt and inner surface of the piston, and wrap-interlock preforms strengthen the piston crown and wrist pin bosses

NEWS: the near-infrared Echelle for wideband spectroscopy

We present an updated optical and mechanical design of NEWS: the Near-infrared Echelle for Wide-band Spectroscopy (formerly called HiJaK: the High-resolution J, H and K spectrometer), a compact, high-resolution, near-infrared spectrometer for 5-meter class telescopes. NEWS provides a spectral resolution of 60,000 and covers the full 0.8-2.5 micron range in 5 modes. We adopt a compact, lightweight, monolithic design and developed NEWS to be mounted to the instrument cube at the Cassegrain focus of the the new 4.3-meter Discovery Channel Telescope.Comment: Proc. SPIE 9908, Ground-based and Airborne Instrumentation for Astronomy VI, 99086M (August 9, 2016

Indigenizing Colonial Modernity in Nam Bo

The Vietnamese economic reforms of the 1980s and 1990s were accompanied by a number of significant reversals among state social scientists writing on the legacy of pre-socialist alternatives in southern Vietnam. After the failed attempt to carry the momentum of military victory into the project of post-war economic development, Vietnam's communist leaders identified "voluntarism" and lack of attention to "objective conditions" as the key weaknesses of their economic unification policies. To revitalize the project of constructing socialism, social science researchers were charged with reinventorying the distinctive attributes which the area of Vietnam below the 17th parallel, could contribute to the nation's reforms