A standard tool in general relativity is the 3+1 or ADM point of view, namely
slicing spacetime into spacelike hypersurfaces of constant time and then describing
physics in terms of time-dependent quantities on a typical such hypersurface. Much
less well-known is the 1+3 point of view, in which one foliates...
Quantum field theory has enjoyed much success, indeed for ordinary flat spacetime applications it has been experimentally verified to a great deal of accuracy. However on general cursed spacetime backgrounds there is no canonical method for constructing a quantum field theory. In 1975, Abhay Ashtekar and Anne Magnon made progress...
Multiple-input multiple-output (MIMO) antenna technology is promising
for high-speed wireless communications without increasing the transmission band-
width. Space time coding (STC) is a scheme that employs multiple antennas to
increase transmission rate or to improve transmission quality. STC is used widely
in mobile cellular networks, wireless local area networks (WLAN)...
The North American interconnected power systems continuously
attempt to hold power system time as close to standard time as possible.
All inherent problems associated with normal power system
operation make this a difficult task. System time is presently allowed
to deviate from standard time by up to two seconds before...
The purpose of this study was to investigate: (1) whether the use of the Motions computer program will be more effective in the acquisition of transformation geometry concepts in eighth-grade students than the use of the Mira hands-on manipulative, (2) whether the use of the Motions computer program will be...
The development of a novel high temperature space radiator is
described. A Rotating Bubble Membrane Radiator (RBMR) combines the
best features of heat pipes and droplet radiators while avoiding
their negative attributes. The RBMR offers light weight, self
deployment, ease of startup and its performance is less affected by
acceleration....
This investigation was designed to determine the extent to which
students who are completing planned curricula in mathematics education
are proficient in spatial visualization abilities and possess mathematical
understandings. The effects of mathematics curricula upon
the development of these abilities and understandings and the relationships
between these abilities and understandings...
Five Ultra light Fabric Reflux Tubes (UFRTs) were tested in a thermal vacuum chamber at the National Aeronautics and Space Administration's Johnson Space Center in September 1994. These test articles were design and fabricated by staff at the Pacific Northwest Laboratory, operated by Battelle Memorial Institute for the United States...
An enabling technology for long duration, deep space missions is the availability of a high power, long-lived power supply. The goal of this work is the design of a self-regulating deep space nuclear reactor. The design objectives are to produce 250 kWth for a 25-year period using the presence of...
