1,337 research outputs found
Recommended from our members
Higher education academic salaries in the UK
It is widely believed that higher education academic salaries are too low, and that this may lead to a ‘brain drain’ and also lower quality in higher education, as universities fail to attract the ‘brightest and the best’. We compare the salaries of Higher Education teaching professionals in the UK with those of other comparable professionals. We compare academic salaries to a range of occupational groupings that one might view as similar, in terms of unobserved characteristics, to academics. We conclude that HE teaching professionals earn lower earnings than most public sector graduates and do particularly poorly compared to most other comparable professionals. In particular, academic earnings compare poorly to those in the legal professions, consultant physicians and dental practitioners (across both the public and private sectors). On the other hand, some public sector workers do worse than HE academics, e.g. FE teachers
Investigation of Atmospheric Reentry for the Space Maneuver Vehicle
This study investigated the atmospheric reentry of the Space Maneuver Vehicle from low-earth orbit using an entry guidance concept similar to the Space Shuttle. The Space Maneuver Vehicle was modeled as a point mass with aerodynamic properties as determined using Newtonian impact theory. For the rarefied-flow transition regime bridging formulae are used to capture the effects of both hypersonic continuum flow and free molecular flow. Constraints to the reentry are developed and a reentry corridor is defined in the drag-velocity plane. Bank angle modulation is established as the primary means for controlling drag and range. The guidance concept is applied to both a high inclination orbit and a low inclination orbit with cross-range requirement. Monte Carlo error analysis validates the ability of the control algorithm to guide reentry in the presence of initial state errors, as well as atmospheric variations
Spitzer observations of extragalactic H II regions - III. NGC 6822 and the hot star, H II region connection
Using the short-high module of the Infrared Spectrograph on the Spitzer Space
Telescope, we have measured the [S IV] 10.51, [Ne II] 12.81, [Ne III] 15.56,
and [S III] 18.71-micron emission lines in nine H II regions in the dwarf
irregular galaxy NGC 6822. These lines arise from the dominant ionization
states of the elements neon (Ne, Ne) and sulphur (S,
S), thereby allowing an analysis of the neon to sulphur abundance ratio
as well as the ionic abundance ratios Ne/Ne and S/S.
By extending our studies of H II regions in M83 and M33 to the lower
metallicity NGC 6822, we increase the reliability of the estimated Ne/S ratio.
We find that the Ne/S ratio appears to be fairly universal, with not much
variation about the ratio found for NGC 6822: the median (average) Ne/S ratio
equals 11.6 (12.20.8). This value is in contrast to Asplund et al.'s
currently best estimated value for the Sun: Ne/S = 6.5. In addition, we
continue to test the predicted ionizing spectral energy distributions (SEDs)
from various stellar atmosphere models by comparing model nebulae computed with
these SEDs as inputs to our observational data, changing just the stellar
atmosphere model abundances. Here we employ a new grid of SEDs computed with
different metallicities: Solar, 0.4 Solar, and 0.1 Solar. As expected, these
changes to the SED show similar trends to those seen upon changing just the
nebular gas metallicities in our plasma simulations: lower metallicity results
in higher ionization. This trend agrees with the observations.Comment: 22 pages, 13 figures. To be published in MNRAS. reference added and
typos fixed. arXiv admin note: text overlap with arXiv:0804.0828, which is
paper II by Rubin et al. (2008
A First Comparison of SLOPE and Other LIGO Burst Event Trigger Generators
A number of different methods have been proposed to identify unanticipated
burst sources of gravitational waves in data arising from LIGO and other
gravitational wave detectors. When confronted with such a wide variety of
methods one is moved to ask if they are all necessary, i.e. given detector data
that is assumed to have no gravitational wave signals present, do they
generally identify the same events with the same efficiency, or do they each
'see' different things in the detector? Here we consider three different
methods, which have been used within the LIGO Scientific Collaboration as part
of its search for unanticipated gravitational wave bursts. We find that each of
these three different methods developed for identifying candidate gravitational
wave burst sources are, in fact, attuned to significantly different features in
detector data, suggesting that they may provide largely independent lists of
candidate gravitational wave burst events.Comment: 10 Pages, 5 Figures, Presented at the 10th Gravitational Wave Data
Analysis Workshop (GWDAW-10), 14-17 December 2005 at the University of Texas,
Brownsvill
DNA Fingerprinting of Mycobacterium tuberculosis: Lessons Learned and Implications for the Future
DNA fingerprinting of Mycobacterium tuberculosis—a relatively new laboratory technique—offers promise as a powerful aid in the prevention and control of tuberculosis (TB). Established in 1996 by the Centers for Disease Control and Prevention (CDC), the National Tuberculosis Genotyping Surveillance Network was a 5-year prospective, population-based study of DNA fingerprinting conducted from 1996 to 2000. The data from this study suggest multiple molecular epidemiologic and program management uses for DNA fingerprinting in TB public health practice. From these data, we also gain a clearer understanding of the overall diversity of M. tuberculosis strains as well as the presence of endemic strains in the United States. We summarize the key findings and the impact that DNA fingerprinting may have on future approaches to TB control. Although challenges and limitations to the use of DNA fingerprinting exist, the widespread implementation of the technique into routine TB prevention and control practices appears scientifically justified
- …