30,295 research outputs found
Antenna Technology for QUASAT application
A hybrid growth version of the advanced Sunflower, or precision deployable, antenna was adopted as the configuration proposed for the QUASAT very long baseline interferometry mission. The antenna consists of rigid panels of graphite-epoxy facesheets covering aluminum honeycomb sandwich. The six main folding panels are hinged to a cantilevered support ring attached to the periphery of the center section. Six pairs of intermediate panels are located between these panels and are hinged to each other and to the main panels. The flight configuration, antenna weight, a mass properties, frequency, and contour tolerance are discussed. The advantages of the solid antenna surface cover an all-mesh contour are examined
Apparatus for testing a pressure responsive instrument Patent
Control system for pressure balance device used in calibrating pressure gage
High Energy Colliders
We consider the high energy advantages, disadvantages and luminosity
requirements of hadrons, leptons and photon-photon colliders. Technical
problems in obtaining increased energy in each type of machine are presented.
The machines relative size are also discussed.Comment: LaTeX, 27 pages, 8 figures (eps, ps). Submitted to the Proceedings of
the Princeton's 250th Anniversary Conference on Critical Problems in Physic
High Luminosity Muon Collider Design
Muon Colliders have unique technical and physics advantages and disadvantages
when compared with both hadrons and electron machines. They should be regarded
as complementary. Parameters are given of a 4 TeV high luminosity muon-muon
collider, and of a 0.5 TeV demonstration machine. We discuss the various
systems in such muon collider.Comment: LaTeX 5 pages 4 figure
Future Colliders
The high energy physics advantages, disadvantages and luminosity requirements
of hadrons, of leptons and photon-photon colliders are considered. Technical
arguments for increased energy in each type of machine are presented. Their
relative size, and the implications of size on cost are discussed.Comment: LaTeX, 10 pages, 10figure
On Painleve VI transcendents related to the Dirac operator on the hyperbolic disk
Dirac hamiltonian on the Poincare disk in the presence of an Aharonov-Bohm
flux and a uniform magnetic field admits a one-parameter family of self-adjoint
extensions. We determine the spectrum and calculate the resolvent for each
element of this family. Explicit expressions for Green functions are then used
to find Fredholm determinant representations for the tau function of the Dirac
operator with two branch points on the Poincare disk. Isomonodromic deformation
theory for the Dirac equation relates this tau function to a one-parameter
class of solutions of the Painleve VI equation with . We analyze long
distance behaviour of the tau function, as well as the asymptotics of the
corresponding Painleve VI transcendents as . Considering the limit of
flat space, we also obtain a class of solutions of the Painleve V equation with
.Comment: 38 pages, 5 figure
VLA observations of 6-cm excited OH
The VLA was used to determine precise positions for 4765-MHz OH maser
emission sources toward star-forming regions which had been observed about
seven months earlier with the Effelsberg 100-meter telescope. The observations
were successful for K3-50, DR21EX, W75N, and W49A. No line was detected toward
S255: this line had decreased to less than 5 per cent of the flux density
observed only seven months earlier. The time-variability of the observed
features during the past 30 years is summarised. In addition, to compare with
the Effelsberg observations, the 4750-MHz and 4660-MHz lines were observed in
W49A. These lines were found to originate primarily from an extended region
which is distinguished as an exceptional collection of compact continuum
components as well as by being the dynamical centre of the very powerful H_2 O
outflow.Comment: 11 pages, will require MN style file to process. MNRAS, accepted Oct
15, 200
Extreme distributions of ground winds /3 to 150 meters/ at Cape Kennedy, Florida
Statistical analysis of wind distribution probabilities at Cape Kenned
A Pulsed Synchrotron for Muon Acceleration at a Neutrino Factory
A 4600 Hz pulsed synchrotron is considered as a means of accelerating cool
muons with superconducting RF cavities from 4 to 20 GeV/c for a neutrino
factory. Eddy current losses are held to less than a megawatt by the low
machine duty cycle plus 100 micron thick grain oriented silicon steel
laminations and 250 micron diameter copper wires. Combined function magnets
with 20 T/m gradients alternating within single magnets form the lattice. Muon
survival is 83%.Comment: 4 pages, 1 figures, LaTeX, 5th International Workshop on Neutrino
Factories and Superbeams (NuFact 03), 5-11 Jun 2003, New Yor
Development of stitching reinforcement for transport wing panels
The NASA Advanced Composites Technology (ACT) program has the objective of providing the technology required to obtain the full benefit of weight savings and performance improvements offered by composite primary aircraft structures. Achieving the objective is dependent upon developing composite materials and structures which are damage tolerant and economical to manufacture. Researchers are investigating stitching reinforcement combined with resin transfer molding to produce materials meeting the ACT program objective. Research is aimed at materials, processes, and structural concepts for application in both transport wings and fuselages, but the emphasis to date has been on wing panels. Empirical guidelines are being established for stitching reinforcement in structures designed for heavy loads. Results are presented from evaluation tests investigating stitching types, threads, and density (penetrations per square inch). Tension strength, compression strength, and compression after impact data are reported
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