4,342 research outputs found
Calculated and flight measured handling- qualities factors of three subsonic jet transports
Calculated and flight measured handling quality factors of three subsonic jet transport
The distance to NGC 6397 by M-subdwarf main-sequence fitting
Recent years have seen a substantial improvement both in photometry of low
luminosity stars in globular clusters and in modelling the stellar atmospheres
of late-type dwarfs. We build on these observational and theoretical advances
in undertaking the first determination of the distance to a globular cluster by
main-sequence fitting using stars on the lower main sequence. The calibrating
stars are extreme M subdwarfs, as classified by Gizis (1997), with parallaxes
measured to a precision of better than 10%. Matching against King et al's
(1998) deep (V, (V-I)) photometry of NGC 6397, and adopting E_{B-V}=0.18 mag,
we derive a true distance modulus of 12.13 +- 0.15 mag for the cluster. This
compares with (m-M)_0=12.24 +- 0.1 derived through conventional main-sequence
fitting in the (V, (B-V)) plane. Allowing for intrinsic differences due to
chemical composition, we derive a relative distance modulus of delta
(m-M)_0=2.58 mag between NGC 6397 and the fiducial metal-poor cluster M92. We
extend this calibration to other metal-poor clusters, and examine the resulting
RR Lyrae (M_V, [Fe/H]) relation.Comment: 19 pages, AASTeX, to appear in the December 1998 A
A vapor barrier for cold testing printed circuit cards
Cold testing method prevents formation of frost on printed circuit boards and part holders during testing at sub-zero temperatures. Freon permits rapid attainment of the required testing temperature
A simulator and flight study of yaw coupling in turning maneuvers of large transport aircraft
Piloted simulator study of yaw coupling in turning maneuvers of supersonic transport compared with flight test data on large variable stability jet transpor
Exotic coloured fermions and lepton number violation at the LHC
Majorana neutrino mass models with a scale of lepton number violation (LNV)
of order TeV potentially lead to signals at the LHC. Here, we consider an
extension of the standard model with a coloured octet fermion and a scalar
leptoquark. This model generates neutrino masses at 2-loop order. We make a
detailed MonteCarlo study of the LNV signal at the LHC in this model, including
a simulation of standard model backgrounds. Our forecast predicts that the LHC
with 300/fb should be able to probe this model up to colour octet fermion
masses in the range of (2.6-2.7) TeV, depending on the lepton flavour of the
final state.Comment: 14 pages, 2 figure
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