6,918 research outputs found
A topographic origin for double-ridge features in visible imagery of ice divides in Antarctica
Exploratory Meeting on Airborne Doppler Lidar Wind Velocity Measurements
The scientific interests and applications of the Airborne Doppler Lidar Wind Velocity Measurement System to severe storms and local weather are discussed. The main areas include convective phenomena, local circulation, atmospheric boundary layer, atmospheric dispersion, and industrial aerodynamics
Pm receiver rf test console, appendix f final rep
Technical description of phase-modulation receiver developed in radio-frequency console progra
Nonlinear soil-structure interaction calculations simulating the SIMQUAKE experiment using STEALTH 2D
Transient, nonlinear soil-structure interaction simulations of an Electric Power Research Institute, SIMQUAKE experiment were performed using the large strain, time domain STEALTH 2D code and a cyclic, kinematically hardening cap soil model. Results from the STEALTH simulations were compared to identical simulations performed with the TRANAL code and indicate relatively good agreement between all the STEALTH and TRANAL calculations. The differences that are seen can probably be attributed to: (1) large (STEALTH) vs. small (TRANAL) strain formulation and/or (2) grid discretization differences
Spacelab 3: Research in microgravity
The Spacelab 3 mission, which focused on research in microgravity, took place during the period April 29 through May 6, 1985. Spacelab 3 was the second flight of the National Aeronautics and Space Administration's modular Shuttle-borne research facility. An overview of the mission is presented. Preliminary scientific results from the mission were presented by investigators at a symposium held at Marshall Space Flight Center on December 4, 1985. This special issue is based on reports presented at that symposium
Computed Normal Range of Iowa Statewide July Precipitation
Iowa summer rainfall distributions are examined to identify small-scale anomalies. Examination of extremely wet and dry summer months shows that large rain amounts fall mainly in small, cellular areas for both extremely wet and dry months. These configurations result from individual rainfall events. Analysis of the distribution of mean July rainfall across the state reveals significant anomalous wet and dry regions that contrast with the background, east-west rainfall gradient. Because of the skewed nature of summer rainfall distributions, the median value is used to represent a more realistic expected rainfall amount for any given year. Some parts of the stare have a more variable distribution and are more sensitive to the expected annual swing of one standard deviation. On the basis of statistical probabilities, these areas can expect summers of more severe moisture deficiencies to occur more often than in the rest of the stare
Paramagnetic Resonance Absorption in Some Organic Biradicals
Four compounds of the form 4,4′‐polymethylenebistriphenylmethyl, one compound of the form (1,4‐phenylene)bisdiarylmethyl, three compounds of the form (4,4′‐biphenylene)bisdiarylmethyl, and one compound, 4,4′‐oxybistriphenylmethyl have been shown to possess unpaired electrons by paramagnetic resonance absorption. The resonance spectra of 0.01 M solutions of these compounds in benzene exhibit a hyperfine structure arising from a spherically symmetrical contribution of the magnetic dipole interaction between the unpaired electron and the nuclear magnetic moments of the hydrogen atoms. The g‐factors for the compounds investigated in the first three classes were found to be 2.0025±0.0004 and 2.0031±0.0004 for the last compound. Such a close approach of the g‐factor to the free electron value plus the sharpness of the hyperfine structure lines indicates that the anisotropic contributions of the spin‐orbit interaction, which would normally lift the degeneracy of the triplet state, are averaged out by the tumbling of the molecules.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70965/2/JCPSA6-25-4-697-1.pd
Discovery of KiloHertz Quasi-Periodic Oscillations in 4U 1735-44
We discovered a single kHz quasi-periodic oscillation (QPO) near 1150 Hz in
the Rossi X-ray Timing Explorer X-ray light curve of the low mass X-ray binary
and atoll source 4U 1735-44. The rms amplitude of this peak was 2-3%, and the
FWHM 6-40 Hz. There are indications that the kHz QPO frequency decreased from
1160 Hz to 1145 Hz when the count rate increased, which would be quite
different from what is observed in other atoll sources for which kHz QPOs have
been discovered. In the X-ray color-color diagram and hardness-intensity
diagram the source traced out the curved branch (the so-called banana branch)
which has been found by previous instruments. The kHz QPO was only detected
when the source was at the lowest count rates during our observations, i.e. on
the lower part of the banana branch. When 4U 1735-44 was at higher count rates,
i.e. on the upper part of the banana branch and at higher inferred mass
accretion rate with respect to that on the lower part of the banana branch, the
QPO was not detected.
Besides the kHz QPO we discovered a low frequency QPO with a frequency near
67 Hz, together with a complex broad peaked noise component below 30 Hz. This
67 Hz QPO may be related to the magnetospheric beat-frequency QPO, which is
observed on the horizontal branch of Z sources. This idea is supported by the
(peaked) noise found in both 4U 1735-44 and Z sources at frequencies just below
the QPO frequency.Comment: 9 pages, including 2 figures. Accepted for publication in ApJ Letter
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