16,851 research outputs found
The case for Mars concept
The Case for Mars workshops conducted in 1984 dealt with a program to establish a permanent scientific research base at Mars. The participants, viewed a Mars base as the much needed long-term focus for the space program. A permanent base was chosen rather than the more conventional concept of a series of individual missions to different sites became the permanent base offers much greater scientific return plus greater crew safety and the potential for growth into a true colony. The results of the workshops are summarized
The Mars airplane
The concept of the Mars airplane was developed as a potential vehicle for unmanned Mars exploration. It is suggested that its most appropriate use would be as an unmanned adjunct to a manned mission. Functions such as reconnaissance, exploration, remote delivery of instruments, etc., are possible. Several operational aspects of such a vehicle are unique compared to Earth operating aircraft
Jet pump-drive system for heat removal
A jet pump, in combination with a TEMP, is employed to assure safe cooling of a nuclear reactor after shutdown. A TEMP, responsive to the heat from the coolant in the secondary flow path, automatically pumps the withdrawn coolant to a higher pressure and thus higher velocity compared to the main flow. The high velocity coolant is applied as a driver flow for the jet pump which has a main flow chamber located in the main flow circulation pump. Upon nuclear shutdown and loss of power for the main reactor pumping system, the TEMP/jet pump combination continues to boost the coolant flow in the direction it is already circulating. During the decay time for the nuclear reactor, the jet pump keeps running until the coolant temperature drops to a lower and safe temperature. At this lower temperature, the TEMP/jet jump combination ceases its circulation boosting operation. The TEMP/jet pump combination is automatic, self-regulating and provides an emergency pumping system free of moving parts
The development of methods for the early identification of heart disease and related job stresses Progress report, 1 Mar. - 30 Jun. 1969
Methods for early identification of heart disease and related job stresse
Underlying symmetries of realistic interactions and the nuclear many-body problem
The present study brings forward important information, within the framework
of spectral distribution theory, about the types of forces that dominate three
realistic interactions, CD-Bonn, CDBonn+ 3terms and GXPF1, in nuclei and their
ability to account for many-particle effects such as the formation of
correlated nucleon pairs and enhanced quadrupole collective modes.
Like-particle and proton-neutron isovector pairing correlations are described
microscopically by a model interaction with Sp(4) dynamical symmetry, which is
extended to include an additional quadrupole-quadrupole interaction. The
analysis of the results for the 1f7/2 level shows that both CD-Bonn+3terms and
GXPF1 exhibit a well-developed pairing character compared to CD-Bonn, while the
latter appears to build up more (less) rotational isovector T = 1 (isoscalar T
= 0) collective features. Furthermore, the three realistic interactions are in
general found to correlate strongly with the pairing+quadrupole model
interaction, especially for the highest possible isospin group of states where
the model interaction can be used to provide a reasonable description of the
corresponding energy spectra.Comment: 12 pages, 4 figure
Neurophysiological and Behavioral Studies of Chimpanzees Semiannual Report, 1 Jul. - 31 Dec. 1966
Computer program for control of chimpanzee discrimination test analysis and electroencephalographic response dat
Monitoring brain function and performance in the primate under prolonged weightlessness Final report, 15 Aug. 1963 - 14 Aug. 1964
Summary of program for monitoring brain function and performance in primate under prolonged weightlessnes
Neurophysiological and behavioral studies of chimpanzees Semiannual report, Jan. 1 - Jun. 30, 1966
Techniques and bioinstrumentation for behavioral and neurophysiological studies of chimpanzees and Apollo application
Summer Institute in Space Biology Final report, Apr. 1 - Nov. 30, 1968
Space biology laboratory on effects of aerospace environments on physiological and psychological performance of astronaut
Relativistic U(3) Symmetry and Pseudo-U(3) Symmetry of the Dirac Hamiltonian
The Dirac Hamiltonian with relativistic scalar and vector harmonic oscillator
potentials has been solved analytically in two limits. One is the spin limit
for which spin is an invariant symmetry of the the Dirac Hamiltonian and the
other is the pseudo-spin limit for which pseudo-spin is an invariant symmetry
of the the Dirac Hamiltonian. The spin limit occurs when the scalar potential
is equal to the vector potential plus a constant, and the pseudospin limit
occurs when the scalar potential is equal in magnitude but opposite in sign to
the vector potential plus a constant. Like the non-relativistic harmonic
oscillator, each of these limits has a higher symmetry. For example, for the
spherically symmetric oscillator, these limits have a U(3) and pseudo-U(3)
symmetry respectively. We shall discuss the eigenfunctions and eigenvalues of
these two limits and derive the relativistic generators for the U(3) and
pseudo-U(3) symmetry. We also argue, that, if an anti-nucleon can be bound in a
nucleus, the spectrum will have approximate spin and U(3) symmetry.Comment: Submitted to the Proceedings of "Tenth International Spring
Seminar-New Quests in Nuclear Structure", 6 page
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