28,528 research outputs found
Investigation of system readiness when some defect types are unknown
Unbiased estimate and tests for readiness index for systems with unknown defects not causing system failur
Inflatable tether Patent
Space expandable tether device for use as passageway between two docked spacecraf
Stimulated emission and excited-state absorption at room temperature on the 550 nm-laser transition in Er3+ doped YAlO3
A pump- and probe-beam technique is used for measuring time-resolved and cw-pumped excited-state absorption (ESA) and stimulated-emission (SE) spectra of Er3+:YAlO3 with high resolution. In combination with absorption and fluorescence spectra, detailed information on the wavelengths and cross-sections of ESA and SE at the 550 nm laser transition is provided
Color and Variability Characteristics of Point Sources in the Faint Sky Variability Survey
We present an analysis of the color and variability characteristics for point
sources in the Faint Sky Variability Survey (FSVS). The FSVS cataloged ~23
square degrees in BVI filters from ~16--24 mag to investigate variability in
faint sources at moderate to high Galactic latitudes. Point source completeness
is found to be >83% for a selected representative sample (V=17.5--22.0 mag,
B-V=0.0--1.5) containing both photometric B, V detections and 80% of the
time-sampled V data available compared to a basic internal source completeness
of 99%. Multi-epoch (10--30) observations in V spanning minutes to years
modeled by light curve simulations reveal amplitude sensitivities to
0.015--0.075 mag over a representative V=18--22 mag range. Periodicity
determinations appear viable to time-scales of an order 1 day or less using the
most sampled fields (~30 epochs). The fraction of point sources is found to be
generally variable at 5--8% over V=17.5--22.0 mag. For V brighter than 19 mag,
the variable population is dominated by low amplitude (<0.05 mag) and blue
(B-V<0.35) sources, possibly representing a population of gamma Doradus stars.
Overall, the dominant population of variable sources are bluer than B-V=0.65
and have Main Sequence colors, likely reflecting larger populations of RR
Lyrae, SX Phe, gamma Doradus, and W UMa variables.Comment: 34 pages, 16 figures, accepted in A
Compensating linkage for main rotor control
A compensating linkage for the rotor control system on rotary wing aircraft is described. The main rotor and transmission are isolated from the airframe structure by clastic suspension. The compensating linkage prevents unwanted signal inputs to the rotor control system caused by relative motion of the airframe structure and the main rotor and transmission
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