6,469 research outputs found
Liquid crystal light valve structures
An improved photosensor film and liquid crystal light valves embodying said film is provided. The photosensor film and liquid crystal light valve is characterized by a significant lower image retention time while maintaining acceptable photosensitivity. The photosensor film is produced by sputter depositing CdS onto an ITO substrate in an atmosphere of argon/H2S gas while maintaining the substrate at a temperature in the range of about 130 C to about 200 C and while introducing nitrogen gas into the system to the extent of not more than about 1% of plasma mixture. Following sputter deposition of the CdS, the film is annealed in an inert gas at temperatures ranging from about 300 C to about 425 C
Multi-Phase Gas Dynamics in a Weak Barred Potential
The structure of the interstellar medium in the central kpc region of a
galaxy with a weak bar-like potential is investigated taking into account
realistic cooling and heating processes and the self-gravity of the gas. Using
high resolution hydrodynamical simulations, it is revealed that the resonant
structures (e.g. smooth spiral shocks and a nuclear ring) are very different
from those seen in past numerical models where simple models of the ISM, i.e.
non-self-gravitating, isothermal gas were assumed. We find that the pc-scale
filaments and clumps form large scale spirals, which resemble those seen in
real galaxies. The fine structures are different between the arms and in the
nuclear region. The next generation millimeter interferometer (ALMA) may reveal
the fine structures of the cold gas in nearby galaxies. We also find a large
scale anisotropy in the gas temperature, which is caused due to non-circular
velocity field of the gas.The damped orbit model based on the epicyclic
approximation explains the distribution of the hot (> 10^4 K) and cold (< 100
K) gases appearing alternately around the galactic center. Because of the
temperature anisotropy, cold gases observed by molecular lines do not
necessarily represent the real gas distribution in galaxies. Position-Velocity
diagrams depend strongly on the viewing angles. As a result, the rotational
velocity inferred from the PV maps could be two times larger or smaller than
the true circular velocity.Comment: 7 pages, 8 figures, to appear in PASJ, vol. 56, no.6 (2001
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