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...
Preliminary nuclear design studies have been completed on ten
configurations of nuclear reactors for low power (1-30 kWe) space
applications utilizing thermionic energy conversion. Additional design
studies have been conducted on the TRICE multimegawatt in-core
thermionic reactor configuration. In each of the cases, a reactor
configuration has been determined which...
The accomplishments presented in this thesis are the development of three models
for simulation of space charge generation in the phosphor layer of alternating current
thin-film electroluminescent (ACTFEL) devices and the results from simulation
of these models. First, a single sheet charge model is developed and simulated.
The single sheet...
The United States Forest Service's Passport In Time program is designed to involve the public in archaeology on National Forest land. Three of the program's goals are: 1) allow archaeologists to conduct research they would not otherwise have the time or the budget to conduct; 2) teach the public about...
Studies addressed impacts of planting dates and variable N applications on numbers
and size of Russet Burbank stems and stolon nodal position in relation to tuber growth and levels of hollow heart (HH) and brown center (BC). Low preplant N regimes produced larger tubers and final yields, and less HH...
A rotating, flat plate condensation experiment has been developed to
investigate the heat of the Rotating Bubble Membrane Radiator (RBMR). The
RBMR is a proposed heat rejection system for space applications which uses
working fluid condensation on the inside surface of a rotating sphere to
reject heat to space. The...
Incore thermionic space reactor design concepts which operate at a
nominal power output range of 20 to 50 kWe are described. Details of the
neutronic, thermionic, thermal hydraulics and shielding performance are
presented. Due to the strong absorption of thermal neutrons by natural
tungsten, and the large amount of that...
An overall systems design code was developed to model
an advanced in-core thermionic energy conversion based
nuclear reactor system for space applications at power
levels of 10 to 50 kWe. The purpose of this work was to
provide the overall shell for the systems code and to also
provide the...
Delta-Sigma (ΔΣ) analog-to-digital converters (ADCs) are traditionally used in high quality audio systems, instrumentation and measurement (I&M) and biomedical devices. With the continued downscaling of CMOS technology, they are becoming popular in wideband applications such as wireless and wired communication systems,high-definition television and radar systems. There are two general realizations...
The Absaroka volcanic province is the largest of Eocene volcanic fields in the northern Cordillera of the western U.S., and consists of 25,000 km2 of lava flows, shallow intrusions, ash-flow tuffs and volcaniclastic deposits. It is aligned with northwest-trending Precambrian lineaments, and includes the remains of at least ten volcanic...