8,858 research outputs found
LANDSAT survey of near-shore ice conditions along the Arctic coast of Alaska
The author has identified the following significant results. Winter and spring near-shore ice conditions were analyzed for the Beaufort Sea 1973-77, and the Chukchi Sea 1973-76. LANDSAT imagery was utilized to map major ice features related to regional ice morphology. Significant features from individual LANDSAT image maps were combined to yield regional maps of major ice ridge systems for each year of study and maps of flaw lead systems for representative seasons during each year. These regional maps were, in turn, used to prepare seasonal ice morphology maps. These maps showed, in terms of a zonal analysis, regions of statistically uniform ice behavior. The behavioral characteristics of each zone were described in terms of coastal processes and bathymetric configuration
The formation of galaxy disks in a hierarchical universe
The formation of galactic discs and the efficiency of star formation within
them are issues central to our understanding of galaxy formation. We have
developed a detailed and versatile model of disc formation which combines the
strengths of previous studies of isolated discs with those of hierarchical
galaxy formation models. Disc structure is inferred from the distribution of
angular momentum in hot halo gas and the hierarchical build-up of dark matter,
leading to theoretically generated systems where the evolution of surface
density, rotation, velocity dispersion, stability and metallicity is predicted
for annular regions of width 20-100 pc. The model will be used to establish
whether the accepted theory of large-scale structure formation in the universe
is consistent with observed trends in the properties of disc galaxies.
This first paper explicitly examines the importance of embedding such
calculations within a merging hierarchy of dark matter haloes, finding that
this leads to dramatically different formation histories compared to models in
which discs grow in isolation. Different models of star formation are explored,
and are found to have only a secondary influence on the properties of the
resulting galaxy discs, the main governing factor being the infalling gas
supply from the hot halo.Comment: 13 pages, 9 figures, accepted by MNRA
Home curing bacon for a mild flavor (2006)
Most people eat bacon because they like it, not for its nutritional value. Country-cured bacon is usually more salty and less desirable than commercially prepared bacon. This guide will outline procedures for curing bacon to get a mild flavor
A numerical study of interactions and stellar bars
For several decades it has been known that stellar bars in disc galaxies can
be triggered by interactions, or by internal processes such as dynamical
instabilities. In this work, we explore the differences between these two
mechanisms using numerical simulations. We perform two groups of simulations
based on isolated galaxies, one group in which a bar develops naturally, and
another group in which the bar could not develop in isolation. The rest of the
simulations recreate 1:1 coplanar fly-by interactions computed with the impulse
approximation. The orbits we use for the interactions represent the fly-bys in
groups or clusters of different masses accordingly to the velocity of the
encounter. In the analysis we focus on bars' amplitude, size, pattern speed and
their rotation parameter, . The latter is used to
define fast (). Compared with
equivalent isolated galaxies we find that bars affected or triggered by
interactions: (i) remain in the slow regime for longer; (ii) are more boxy in
face-on views; (iii) they host kinematically hotter discs. Within this set of
simulations we do not see strong differences between retrograde or prograde
fly-bys. We also show that slow interactions can trigger bar formation.Comment: 12 pages, 7 figures. Accepted for publication in MNRA
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The dependence of minimum-time routes over the North Atlantic on cruise altitude
North Atlantic air traffic is broadly organised into a track system; daily sets of tracks are defined by air traffic control which are vertically stacked, such that the same set of tracks is used for all flight levels, regardless of any vertical variations in wind. This work uses minimum-time routes, previously shown to be a good proxy for the location of the North Atlantic track system, to understand whether vertical variations in wind speed and direction significantly affect minimum-time routes optimised at different altitudes; this is to examine whether (all other factors assumed equal) there is potential for improvements in fuel efficiency. The optimum cruise altitude over the North Atlantic is determined, focusing on the New York – London route. It is found that eastbound routes, which take advantage of the jet stream, are on average faster at 250 hPa (flight level (FL) 340) than at 300 hPa (FL300) or 200 hPa (FL390) by approximately 2 minutes (compared to the annual-mean route time of about 330 minutes, assuming a true air speed of 250 m s-1). For westbound routes, the route time increases with height: aircraft flying at 300 hPa are on average 3 minutes faster than at higher levels (the annual-mean optimum time being about 400 minutes). These estimates are compared with the time penalty which arises from flying a route optimized at 250 hPa at the other two altitudes. The time penalty is generally less than a minute, compared to the minimum-time routes calculated at those altitudes
Home slaughtering and processing of beef (1993)
This article cites the proper method and precautions for slaughtering beef cattle at home
Effect of increasing live weight from 220 to 300 pounds on pork carcass characteristics
Digitized 2007 AES MoU.Includes bibliographical references (pages 18-19)
Pharmacotherapy Challenges of Fontan‐Associated Plastic Bronchitis: A Rare Pediatric Disease
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99662/1/phar1290.pd
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