2,279 research outputs found
Study of the stability of the S-IC open-loop propellant-hydraulic system Final report, Jul. 26, 1964 - Jul. 26, 1966
Saturn S-IC open-loop propellant-hydraulic system stud
Results from the EPL monkey-pod experiment conducted as part of the 1974 NASA/Ames shuttle CVT-2
The participation of the Environmental Physiology Laboratory (EPL) in the general purpose laboratory concept verification test 3 is documented. The EPL Monkey-Pod Experiment was designed to incorporate a 10-12 kg, pig tailed monkey, Macaca nemestrina, into the pod and measure the physiological responses of the animal continuously. Four major elements comprise the EPL Monkey-Pod Experiment System: (1) a fiberglass pod containing the instrumented monkey plus feeder and watering devices, (2) an inner console containing the SKYLAB mass spectrometer with its associated valving and electronic controls, sensing, control and monitoring units for lower body negative pressure, feeder activity, waterer activity, temperatures, and gas metabolism calibration, (3) an umbilical complex comprising gas flow lines and electrical cabling between the inner and outer console and (4) an outer console in principle representing the experiment support to be provided from general spacecraft sources
Charged-Particle Motion in Electromagnetic Fields Having at Least One Ignorable Spatial Coordinate
We give a rigorous derivation of a theorem showing that charged particles in
an arbitrary electromagnetic field with at least one ignorable spatial
coordinate remain forever tied to a given magnetic-field line. Such a situation
contrasts the significant motions normal to the magnetic field that are
expected in most real three-dimensional systems. It is pointed out that, while
the significance of the theorem has not been widely appreciated, it has
important consequences for a number of problems and is of particular relevance
for the acceleration of cosmic rays by shocks.Comment: 7 pages, emulateapj format, including 1 eps figure, to appear in The
Astrophysical Journal, Dec. 10 1998 issu
Regularity of solutions to higher-order integrals of the calculus of variations
We obtain new regularity conditions for problems of calculus of variations
with higher-order derivatives. As a corollary, we get non-occurrence of the
Lavrentiev phenomenon. Our main regularity result asserts that autonomous
integral functionals with a Lagrangian having coercive partial derivatives with
respect to the higher-order derivatives admit only minimizers with essentially
bounded derivatives
Cosmic Evolution of Black Holes and Spheroids. IV. The BH Mass - Spheroid Luminosity Relation
From high-resolution images of 23 Seyfert-1 galaxies at z=0.36 and z=0.57
obtained with the Near Infrared Camera and Multi-Object Spectrometer on board
the Hubble Space Telescope (HST), we determine host-galaxy morphology, nuclear
luminosity, total host-galaxy luminosity and spheroid luminosity. Keck
spectroscopy is used to estimate black hole mass (M_BH). We study the cosmic
evolution of the M_BH-spheroid luminosity (L_sph) relation. In combination with
our previous work, totaling 40 Seyfert-1 galaxies, the covered range in BH mass
is substantially increased, allowing us to determine for the first time
intrinsic scatter and correct evolutionary trends for selection effects. We
re-analyze archival HST images of 19 local reverberation-mapped active galaxies
to match the procedure adopted at intermediate redshift. Correcting spheroid
luminosity for passive luminosity evolution and taking into account selection
effects, we determine that at fixed present-day V-band spheroid luminosity,
M_BH/L_sph \propto (1+z)^(2.8+/-1.2). When including a sample of 44 quasars out
to z=4.5 taken from the literature, with luminosity and BH mass corrected to a
self-consistent calibration, we extend the BH mass range to over two orders of
magnitude, resulting in M_BH/L_sph \propto (1+z)^(1.4+/-0.2). The intrinsic
scatter of the relation, assumed constant with redshift, is 0.3+/-0.1 dex (<0.6
dex at 95% CL). The evolutionary trend suggests that BH growth precedes
spheroid assembly. Interestingly, the M_BH-total host-galaxy luminosity
relation is apparently non-evolving. It hints at either a more fundamental
relation or that the spheroid grows by a redistribution of stars. However, the
high-z sample does not follow this relation, indicating that major mergers may
play the dominant role in growing spheroids above z~1.Comment: 39 pages, 11 figures. Accepted for publication in the Astrophysical
Journa
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