31,069 research outputs found
Note On Endomorphism Algebras Of Separable Monoidal Functors
We recall the Tannaka construction for certain types of split monoidal
functor into Vect_{k}, and remove the compactness restriction on the domain
Shape of Cosmic String Loops
Complicated cosmic string loops will fragment until they reach simple,
non-intersecting ("stable") configurations. Through extensive numerical study
we characterize these attractor loop shapes including their length, velocity,
kink, and cusp distributions. We find that an initial loop containing M
harmonic modes will, on average, split into 3M stable loops. These stable loops
are approximately described by the degenerate kinky loop, which is planar and
rectangular, independently of the number of modes on the initial loop. This is
confirmed by an analytic construction of a stable family of perturbed
degenerate kinky loops. The average stable loop is also found to have a 40%
chance of containing a cusp. We examine the properties of stable loops of
different lengths and find only slight variation. Finally we develop a new
analytic scheme to explicitly solve the string constraint equations.Comment: 11 pages, 19 figures. See http://www.phys.cwru.edu/projects/strings/
for more information, movies, code, etc. Minor clarification suggested by
referee. Accepted for publication in Phys. Rev.
Predicted thermal response of a cryogenic fuel tank exposed to simulated aerodynamic heating profiles with different cryogens and fill levels
A two dimensional finite difference thermal model was developed to predict the effects of heating profile, fill level, and cryogen type prior to experimental testing the Generic Research Cryogenic Tank (GRCT). These numerical predictions will assist in defining test scenarios, sensor locations, and venting requirements for the GRCT experimental tests. Boiloff rates, tank-wall and fluid temperatures, and wall heat fluxes were determined for 20 computational test cases. The test cases spanned three discrete fill levels and three heating profiles for hydrogen and nitrogen
PUBLIC ACQUISITION OF RIGHTS TO USE FARM CHEMICALS: POSSIBLE COSTS AND IMPACTS
Crop Production/Industries,
MHD Wave Propagation in the Neighbourhood of Two Null Points
The nature of fast magnetoacoustic and Alfv\'en waves is investigated in a
zero plasma in the neighbourhood of a pair of two-dimensional null
points. This gives an indication of wave propagation in the low solar
corona, for a more complicated magnetic configuration than that looked at by
McLaughlin & Hood (2004). It is found that the fast wave is attracted to the
null points and that the front of the wave slows down as it approaches the null
point pair, with the wave splitting and part of the wave accumulating at one
null and the rest at the other. Current density will then accumulate at these
points and ohmic dissipation will then extract the energy in the wave at these
points. This suggests locations where wave heating will occur in the corona.
The Alfv\'en wave behaves in a different manner in that the wave accumulates
along the separatrices. Hence, the current density will accumulate at this part
of the topology and this is where wave heating will occur. However, the
phenomenon of wave accumulation at a specific place is a feature of both wave
types, and illustrates the importance of studying the topology of the corona
when considering MHD wave propagation.Comment: 11 pages, 14 figure
Measurement of pilot describing functions in single-controller multiloop tasks
Measurement of pilot describing functions in single controller multiloop task
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