4,184 research outputs found
Barriers & facilitators to extended working life : a focus on a predominately female ageing workforce
Many countries are reforming their pension systems so people stay in work for longer
to improve the long-term sustainability of public finances to support an increasing older
population. This research aimed to explore the factors that enable or inhibit people to extend
working life (EWL) in a large UK based retail organisation. Semi-structured interviews were
carried out with a purposive sample (n=30): 15 employees aged ≥ 60 and 15 supervisors
supporting these employees. Older workers were predominately female, reflecting the gender
profile of the older workers in the organisation. Older workers and supervisors reported that
key facilitators to EWL were: good health, the perception that older workers are of value;
flexibility and choice; the need for an ongoing conversation across the life-course; the social
and community aspect of work as a facilitator to EWL; and, the financial necessity to EWL.
Perceived barriers to EWL included poor health, negative impacts of work on health, and a
lack of respect and support
Discovery of a Large-scale Wall in the Direction of Abell 22
We report on the discovery of a large-scale wall in the direction of Abell
22. Using photometric and spectroscopic data from the Las Campanas Observatory
and Anglo-Australian Telescope Rich Cluster Survey, Abell 22 is found to
exhibit a highly unusual and striking redshift distribution. We show that Abell
22 exhibits a foreground wall-like structure by examining the galaxy
distributions in both redshift space and on the colour-magnitude plane. A
search for other galaxies and clusters in the nearby region using the 2dF
Galaxy Redshift Survey database suggests that the wall-like structure is a
significant large-scale, non-virialized filament which runs between two other
Abell clusters either side of Abell 22. The filament stretches over at least
>40 Mpc in length and 10 Mpc in width at the redshift of Abell 22.Comment: 6 pages, 4 figures, accepted for publication in MNRAS letter
Lower Manhattan and the East River: an investigation into the renewal of the Lower East Side waterfront
With the mid-20th Century construction of an elevated highway along Manhattan’s East River, the declining neighborhood of the Lower East Side was removed from its waterfront. As cities begin to re-examine their edges, I feel it is appropriate to address the issues of the Lower East Side community and its former riverfront. Utilizing the recent developments in Manhattan, London, and Chicago as a basis for determining how metropolitan areas are attempting to reconnect with their shores, a set of questions were developed, analyzed, and then applied to the Lower East Side. With the analysis of these questions providing the groundwork for the project, the main concern turns to the elevated highway that has cut through the community along the water’s edge. There are three possible solutions for the future of this ‘wall’ in order to reconnect the Lower East Side with the East River. The first two solutions examine the idea of demolishing the elevated FDR Drive in favor of subterranean or surface streets. The other solution examines the possibility of redesigning the existing elevated highway. In the end, the project focuses on an urban design and planning program that re-establishes the connections between the community and the waterfront
Non-hydrostatic gas in the core of the relaxed galaxy cluster A1795
Chandra data on A1795 reveal a mild edge-shaped discontinuity in the gas
density and temperature in the southern sector of the cluster at r=60/h kpc.
The gas inside the edge is 1.3-1.5 times denser and cooler than outside, while
the pressure is continuous, indicating that this is a "cold front", the surface
of contact between two moving gases. The continuity of the pressure indicates
that the current relative velocity of the gases is near zero, making the edge
appear to be in hydrostatic equilibrium. However, a total mass profile derived
from the data in this sector under the equilibrium assumption, exhibits an
unphysical jump by a factor of 2, with the mass inside the edge being lower. We
propose that the cooler gas is "sloshing" in the cluster gravitational
potential well and is now near the point of maximum displacement, where it has
zero velocity but nonzero centripetal acceleration. The distribution of this
non-hydrostatic gas should reflect the reduced gravity force in the
accelerating reference frame, resulting in the apparent mass discontinuity.
Assuming that the gas outside the edge is hydrostatic, the acceleration of the
moving gas can be estimated from the mass jump, a ~ 800 h km/s/(10^8 yr). The
gravitational potential energy of this gas that is available for dissipation is
about half of its current thermal energy. The length of the cool filament
extending from the cD galaxy (Fabian et al.) may give the amplitude of the gas
sloshing, 30-40/h kpc. Such gas bulk motion might be caused by a disturbance of
the central gravitational potential by past subcluster infall.Comment: Minor text clarifications to correspond to published version. 5
pages, 1 figure in color, uses emulateapj.sty. ApJ Letters in pres
The ROSAT Deep Cluster Survey: the X-ray Luminosity Function out to z=0.8
We present the X-ray Luminosity Function (XLF) of the ROSAT Deep Cluster
Survey (RDCS) sample over the redshift range 0.05-0.8. Our results are derived
from a complete flux-limited subsample of 70 galaxy clusters, representing the
brightest half of the total sample, which have been spectroscopically
identified down to the flux limit of 4*10^{-14} erg/cm^2/s (0.5-2.0 keV) and
have been selected via a serendipitous search in ROSAT-PSPC pointed
observations. The redshift baseline is large enough that evolutionary effects
can be studied within the sample. The local XLF (z < 0.25) is found to be in
excellent agreement with previous determinations using the ROSAT All-Sky Survey
data. The XLF at higher redshifts, when combined with the deepest number counts
constructed to date (f>2*10^{-14} arg/cm^2/s), reveal no significant evolution
at least out to z=0.8, over a luminosity range 2*10^{42}-3*10^{44} erg/s in the
[0.5-2 keV] band. These findings extend the study of cluster evolution to the
highest redshifts and the faintest fluxes probed so far in X-ray surveys. They
complement and do not necessarily conflict with those of the Einstein Extended
Medium Sensitivity Survey, leaving the possibility of negative evolution of the
brightest end of the XLF at high redshifts.Comment: 12 pages, 4 figures, LaTeX (aasms4.sty). To appear in ApJ Letter
Statistical Topological Insulators
We define a class of insulators with gapless surface states protected from
localization due to the statistical properties of a disordered ensemble, namely
due to the ensemble's invariance under a certain symmetry. We show that these
insulators are topological, and are protected by a invariant.
Finally, we prove that every topological insulator gives rise to an infinite
number of classes of statistical topological insulators in higher dimensions.
Our conclusions are confirmed by numerical simulations.Comment: 6 pages, 1 table, 5 figures, this is the final, published versio
The X-ray Fundamental Plane and Relation of Clusters of Galaxies
We analyze the relations among central gas density, core radius, and
temperature of X-ray clusters by plotting the observational data in the
three-dimensional (, , and ) space and find that
the data lie on a 'fundamental plane'. Its existence implies that the clusters
form a two-parameter family. The data on the plane still has a correlation and
form a band on the plane. The observed relation turns
out to be the cross section of the band perpendicular to the major axis, while
the major axis is found to describe the virial density. We discuss implications
of this two-parameter family nature of X-ray clusters.Comment: 7 pages, 2 figures. To be published in ApJ Letter
Flight elements: Fault detection and fault management
Fault management for an intelligent computational system must be developed using a top down integrated engineering approach. An approach proposed includes integrating the overall environment involving sensors and their associated data; design knowledge capture; operations; fault detection, identification, and reconfiguration; testability; causal models including digraph matrix analysis; and overall performance impacts on the hardware and software architecture. Implementation of the concept to achieve a real time intelligent fault detection and management system will be accomplished via the implementation of several objectives, which are: Development of fault tolerant/FDIR requirement and specification from a systems level which will carry through from conceptual design through implementation and mission operations; Implementation of monitoring, diagnosis, and reconfiguration at all system levels providing fault isolation and system integration; Optimize system operations to manage degraded system performance through system integration; and Lower development and operations costs through the implementation of an intelligent real time fault detection and fault management system and an information management system
Discovery of the Central Excess Brightness in Hard X-rays in the Cluster of Galaxies Abell 1795
Using the X-ray data from \ASCA, spectral and spatial properties of the
intra-cluster medium (ICM) of the cD cluster Abell 1795 are studied, up to a
radial distance of ( kpc). The ICM
temperature and abundance are spatially rather constant, although the cool
emission component is reconfirmed in the central region. The azimuthally-
averaged radial X-ray surface brightness profiles are very similar between soft
(0.7--3 keV) and hard (3--10 keV) energy bands, and neither can be fitted with
a single- model due to a strong data excess within of the
cluster center. In contrast, double- models can successfully reproduce
the overall brightness profiles both in the soft and hard energy bands, as well
as that derived with the \ROSAT PSPC. Properties of the central excess
brightness are very similar over the 0.2--10 keV energy range spanned by \ROSAT
and \ASCA. Thus, the excess X-ray emission from the core region of this cluster
is confirmed for the first time in hard X-rays above 3 keV. This indicates that
the shape of the gravitational potential becomes deeper than the King-type one
towards the cluster center. Radial profiles of the total gravitating matter,
calculated using the double- model, reveal an excess mass of within kpc of the cluster
center. This suggests a hierarchy in the gravitational potential corresponding
to the cD galaxy and the entire cluster.Comment: 27 pages, 8 figures; to appear ApJ 500 (June 20, 1998
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