2,688 research outputs found
Clumpy Ultracompact HII Regions I: Fully Supersonic Wind-blown Models
We propose that a significant fraction of the ultracompact HII regions found
in massive star-forming clouds are the result of the interaction of the wind
and ionizing radiation from a young massive star with the clumpy molecular
cloud gas in its neighbourhood. Distributed mass loading in the flow allows the
compact nebulae to be long-lived. In this paper, we discuss a particularly
simple case, in which the flow in the HII region is everywhere supersonic. The
line profiles predicted for this model are highly characteristic, for the case
of uniform mass loading. We discuss briefly other observational diagnostics of
these models.Comment: To appear in Monthly Notices of the Royal Astronomical Society. 5
pages LaTeX (uses mn.sty and epsf.sty macros) + 4 PS figures. Also available
via http://axp2.ast.man.ac.uk:8000/Preprints.htm
Review of Speaking of Jack: A C. S. Lewis Discussion Guide
Review of: Will Vaus, Speaking of Jack: A C. S. Lewis Discussion Guide (Hamden, CT: 2011). 278 pages. $15.00. ISBN: 9781936294121
Prediction of unsteady aerodynamic loadings caused by leading edge and trailing edge control surface motions in subsonic compressible flow: Analysis and results
A theoretical analysis and computer program was developed for the prediction of unsteady lifting surface loadings caused by motions of leading edge and trailing edge control surfaces having sealed gaps. The final form of the downwash integral equation was formulated by isolating the singularities from the nonsingular terms and using a preferred solution process to remove and evaluate the downwash discontinuities in a systematic manner. Comparisons of theoretical and experimental pressure data are made for several control surface configurations. The comparisons indicate that reasonably accurate theoretical pressure distributions and generalized forces may be obtained for a wide variety of control surface configurations. Spanwise symmetry or antisymmetry of motion, and up to six control surfaces on each half span can be accommodated
Pregnancy Immunology
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98130/1/j.1600-0897.1983.tb00238.x.pd
Cervical cancer is not just a young woman's disease
Cervical screening programmes in many countries stop at around the age of 65 and much of the focus is often on younger women. For example, recent media campaigns in England and Wales have centred on lowering the age at first screening. Comparatively little attention has been given to older women despite the fact that they account for about a fifth of cases each year and half of deaths.1 2 Of the 3121 women diagnosed on average each year between 2009 and 2011 in the UK, only 64 were younger than 25 compared with 616 who were older than 65.1 As the population ages, this number of older women affected is set to increase. We argue that screening programmes should reflect this
Towards an explanation for the 30 Dor (LMC) Honeycomb nebula - the impact of recent observations and spectral analysis
The unique Honeycomb nebula, most likely a peculiar supernova remnant, lies
in 30 Doradus in the Large Magellanic Cloud. Due to its proximity to SN1987A,
it has been serendipitously and intentionally observed at many wavelengths.
Here, an optical spectral analysis of forbidden line ratios is performed in
order to compare the Honeycomb high-speed gas with supernova remnants in the
Galaxy and the LMC, with galactic Wolf-Rayet nebulae and with the optical line
emission from the interaction zone of the SS433 microquasar and W50 supernova
remnant system. An empirical spatiokinematic model of the images and spectra
for the Honeycomb reveals that its striking appearance is most likely due to a
fortuitous viewing angle. The Honeycomb nebula is more extended in soft X-ray
emission and could in fact be a small part of the edge of a giant LMC shell
revealed for the first time in this short wavelength domain. It is also
suggested that a previously unnoticed region of optical emission may in fact be
an extension of the Honeycomb around the edge of this giant shell. A secondary
supernova explosion in the edge of a giant shell is considered for the creation
of the Honeycomb nebula. A microquasar origin of the Honeycomb nebula as
opposed to a simple supernova origin is also evaluated.Comment: 12 pages, 9 figures, accepted for publication in MNRA
Variations in the Compositon of Steffens Waste II
Steffens waste is the filtrate from the precipitation of sugar from beet molasses by the addition of lime. The molasses, as it comes from the beet sugar extraction process, contains about 50 per cent sugar, so it is too valuable to be fermented to produce alcohol in this country, although in Europe, much of the beet molasses goes directly to production of alcohol by fermentation
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