3,763 research outputs found
Progress of Forestry Extension in Iowa
Interest and activity in forestry for Iowa is increasing definitely. A brief summary of last year\u27s forestry extension program appears something as follows
Planting Trees on Kansas Prairies
Kansas always has been and always will be essentially a prairie state. But every year brings more convincing proof that her plains need not always remain treeless. Each planting season sees new effort put forth to beautify the Western Kansas homes and divest fhe plains of their traditional bleakness
The Morphology of the Expanding Ejecta of V2491 Cygni (2008 N.2)
Determining the evolution of the ejecta morphology of novae provides valuable
information on the shaping mechanisms in operation at early stages of the nova
outburst. Understanding such mechanisms has implications for studies of shaping
for example in proto-Planetary Nebulae. Here we perform morpho-kinematical
studies of V2491 Cyg using spectral data to determine the likely structure of
the ejecta and its relationship to the central system and shaping mechanisms.
We use Shape to model different morphologies and retrieve their spectra. These
synthetic spectra are compared with observed spectra to determine the most
likely morphology giving rise to them, including system inclination and
expansion velocity of the nova ejecta. We find the best fit remnant morphology
to be that of polar blobs and an equatorial ring with an implied inclination of
80 degrees and an maximum expansion velocity of the polar blobs of
3100 km/s and for the equatorial ring 2700
km/s. This inclination would suggest that we should observe eclipses which will
enable us to determine more precisely important parameters of the central
binary. We also note that the amplitude of the outburst is more akin to the
found in recurrent nova systems.Comment: 9 pages, 7 figures, accepted for publication in MNRA
Topology with Dynamical Overlap Fermions
We perform dynamical QCD simulations with overlap fermions by hybrid
Monte-Carlo method on to lattices. We study the problem of
topological sector changing. A new method is proposed which works without
topological sector changes. We use this new method to determine the topological
susceptibility at various quark masses.Comment: 15 pages, 3 figure
Localized patterns in planar gas-discharge systems
A summary is given of parts of the work that has been done on pattern formation in planar ac- and dc- gas-discharge systems with high ohmic and dielectric barrier respectively, at the Institute of Applied Physics of the University of Muenster. In addition, a qualitative reactiondiffusion model is reviewed that takes account of many of the effects that have been observed experimentally
V723 Cas (Nova Cassiopeiae 1995): MERLIN observations from 1996 to 2001
MERLIN observations of the unusually slow nova V723 Cas are presented. Nine
epochs of 6-cm data between 1996 and 2001 are mapped, showing the initial
expansion and brightening of the radio remnant, the development of structure
and the final decline. A radio light curve is presented and fitted by the
standard Hubble flow model for radio emission from novae in order to determine
the values of various physical parameters for the shell. The model is
consistent with the overall development of the radio emission. Assuming a
distance of 2.39 (+/-0.38) kpc and a shell temperature of 17000 K, the model
yields values for expansion velocity of 414 +/- 0.1 km s^-1 and shell mass of
1.13 +/- 0.04 * 10^-4 Msolar. These values are consistent with those derived
from other observations although the ejected masses are rather higher than
theoretical predictions. The structure of the shell is resolved by MERLIN and
shows that the assumption of spherical symmetry in the standard model is
unlikely to be correct.Comment: 6 pages, 6 figure
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