Optical orientation of the super 3 P sub 0 ground state of Pb super 207.
Orientation of diamagnetic ground state Pb 207 atoms with nonzero orbital angular momentum by means of optical pumping and determination of nuclear moment
Chang, B.↗
SEARCH · Engineering Papers
Results for “Gibbs”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Experimental study of pop-in behavior of surface flaw-type cracks Final report
Growth behavior of surface-flaw type cracks in titanium alloys
Beck, E. J.↗
Flat conductor cable termination development program Final report
Development program for methods of terminating flat conductor cable to small electrical components used on electrical displays and control panels
Gibb, R. W.↗
Propagation of strong field modulated electromagnetic waves in plasmas
Propagation of amplitude modulated, high RF plane electromagnetic wave through anisotropic plasma
Bachnyski, M. P.↗
X-15 propulsion subsystem component development
The X-15 rocket-powered research aircraft was developed by the integrated effort of various areas such as aerodynamics, thermodynamics, and structures. The propulsion subsystem development at the onset of the program was handicapped for varied causes. As a result, early in the flight testing phase, many time-consuming and costly delays were encountered as a result of individual component failures. A review of the X-15 propulsion subsystem components is presented, with a discussion of some of the development problems, how they were alleviated, and how they may be reduced or avoided in future programs. In order to avoid these problems in the future, a program is recommended in the hope that it will increase component reliability commensurate with vehicle objectives.
Robert L. Wiswell↗
Some textures in Apollo 12 lunar igneous rocks and in terrestrial analogs.
The interpretation of immature crystallization and some lunar textures characterized by it are the principal objectives of this investigation. A comparative and selective approach is adopted, and particular reference is made to the form and textural relations of olivine in 12009 and of pyroxenes and plagioclase in 12021, and to terrestrial analogs. The optic orientation of the olivines in 12009 is determined, and their skeletal crystallization is illustrated and evaluated. Microprobe and optical data are associated in a textural analysis of an analog from the upper contact of a minor intrusion in Skye. The optic orientation of pyroxene enclosed in plagioclase cores is determined, and the results are plotted stereographically. The need for greater precision in the use of textural terms is stressed, and a new term - intrafasciculate - is introduced for textures in which pyroxene has crystallized within hollow, skeletal plagioclase. Apollo 12 pyroxene-phyric basalts are texturally reviewed, and the crystallization of the phenocrysts is discussed, emphasis being placed on size-independence of skeletal growth.
Drever, H. I.↗
Space Shuttle Orbiter ECLSS.
The Orbiter Environmental Control and Life Support System (ECLSS) provides the functions of atmosphere revitalization, crew life support, active thermal conditioning, and airlock support for EVA and docking activities. The ECLSS must satisfy the requirements of orbital missions with four to ten crewmembers and mission duration of a few hours to 30 days and the requirements associated with an atmospheric horizontal flight test program and ferry flight missions. The ECLSS development plan utilizes an ECLSS ground test article and thermal/vacuum testing to support the first horizontal flight test at the end of 1976. The ground testing and horizontal flight test program certify the Orbiter ECLSS for the first orbital flight in early 1978.
Stoll, O. T.↗
Solid state power controllers
The rationale, analysis, design, breadboarding and testing of the incremental functional requirements are reported that led to the development of prototype 1 and 5 Amp dc and 1 Amp ac solid state power controllers (SSPC's). The SSPC's are to be considered for use as a replacement of electro-mechanical relays and circuit breakers in future spacecraft and aircraft. They satisfy the combined function of both the relay and circuit breaker and can be remotely controlled by small signals, typically 10 mA, 5 to 28 Vdc. They have the advantage over conventional relay/circuit breaker systems in that they can be located near utilization equipment and the primary ac or dc bus. The low level control, trip indication and status signals can be circuited by small guage wire for control, computer interface, logic, electrical multiplexing, unboard testing, and power management and distribution purposes. This results in increased system versatility at appreciable weight saving and increased reliability.
Gibbs, R. S.↗
Solid state power controllers
Solid state power controllers (SSPC's) are to be considered for use as replacements of electromechanical relays and circuit breakers in future spacecraft and aircraft. They satisfy the combined function of both the relay and circuit breaker and can be remotely controlled by small signals, typically 10 mA, 5 to 28 v(dc). They have the advantage over conventional relay/circuit breaker systems in that they can be located near the utilization equipment and the primary ac or dc bus. The low level control, trip indication and status signals can be circuited by small gauge wire for control, computer interface, logic, electrical multiplexing, onboard testing, power management, and distribution purposes. This results in increased system versatility at appreciable weight saving and increased reliability. Conventional systems require the heavy gage load wiring and the control wiring to be routed from the bus to the load to other remote relay contacts, switches, sensors, etc. and to the circuit breaker located in the flight engineer's compartment for purposes of manual reset.
Gibbs, R. S.↗
Matrix bandwidth and profile reduction
This program, REDUCE, reduces the bandwidth and profile of sparse symmetric matrices, using row and corresponding column permutations. It is a realization of the algorithm described by the authors elsewhere. It was extensively tested and compared with several other programs and was found to be considerably faster than the others, superior for bandwidth reduction and as satisfactory as any other for profile reduction.
Crane, H. L., Jr.↗
MANSEE data analysis results
Results of the data reduction and analysis for the Marine Navigation Systems Evaluation Experiment (MANSEE) are presented. Topics discussed include: the MANSEE test; the navigation sensors which were exercised; the ground truth instrumentation and the processing of ground truth data; and the residual statistics for individual navigation sensors. Residuals were calculated by differencing the actual measurements with anticipated measurements computed from the ground truth trajectory. The results obtained by using the SEAMAP program to filter data from the navigation sensors are also presented. The resultant filtered trajectories were differenced with the corresponding ground truth trajectories to obtain navigation position and velocity errors.
Hatch, W.↗
A study of liquid propellant autoignition
Data and theory pertinent to the autoignition of liquid oxygen/liquid hydrogen and liquid oxygen propellants were reviewed. Physical models of the processes supporting or contributing to autoignition were developed. Emphasis was placed on the description of the physical environment and its relationship to the autoignition phenomenon.
Lester, D. H.↗
An algorithm for reducing the bandwidth and profile of a sparse matrix
A new algorithm for reducing the bandwidth and profile of a sparse matrix is described. Extensive testing on finite element matrices indicates that the algorithm typically produces bandwidth and profile which are comparable to those of the commonly-used reverse Cuthill-McKee algorithm, yet requires significantly less computation time.
Gibbs, N. E.↗
Distributed management of scientific projects - An analysis of two computer-conferencing experiments at NASA
Between August 1975 and March 1976, two NASA projects with geographically separated participants used a computer-conferencing system developed by the Institute for the Future for portions of their work. Monthly usage statistics for the system were collected in order to examine the group and individual participation figures for all conferences. The conference transcripts were analysed to derive observations about the use of the medium. In addition to the results of these analyses, the attitudes of users and the major components of the costs of computer conferencing are discussed.
Vallee, J.↗
Generalization of analytical tools for helicopter-rotor airfoils
A state-of-the-art finite difference boundary-layer program incorporated into the NYU Transonic Analysis Program is described. Some possible treatments for the trailing edge region were investigated. Findings indicate the trailing edge region, still within the scope of an iterative potential flow, boundary layer program, appears feasible.
Gibbs, E. H.↗
NR-150 adhesive development
A polyimide precursor adhesive solution, code-named NR-056X, was developed. It reproducibly gives low void, high strength bond lines at both room temperature and 589K (600 F) using either titanium or graphite/polyimide composite adherends having 12.7 mm (1/2 in.) overlaps. Lap shear samples prepared using this adhesive and composite adherends based on graphite/NR-150B2 were shown to have a high degree of resistance to such adverse environments as air at 589K (600 F), high humidity, methyl ethyl ketone and jet fuel. Bond line toughness was illustrated by the complete resistance to cracking in the wedge-crack propagation test. The available evidence indicates that wide area composite to composite or composite to metal bonding should be feasible.
Blatz, P. S.↗
First measurements of mesospheric vertical velocities by VHF radar at temperate latitudes
A program of ground-based VHF measurements of turbulence and of wave and tidal motions in the mesosphere has been initiated by the University of Illinois using a high-power radar facility located at Urbana, Illinois. Observations show scattering occurring intermittently during the daytime throughout the mesosphere. Vertical velocities exhibit the presence of gravity waves with dominant periods near 10 min and amplitudes ranging from less than 1 m/s to approximately 5 m/s.
Miller, K. L.↗
Performance Analysis of the Spaceborne Laser Ranging System
The 'spaceborne laser ranging system' is a proposed short pulse laser on board an orbiting spacecraft. It measures the distances between the spacecraft and many laser retroreflectors (targets) deployed on the earth's surface. The precision of these range measurements was assumed to be about plus or minus 2 cm. These measurements were then used together with the orbital dynamics of the spacecraft to derive the intersite vector between the laser ground targets. The errors associated with this vector were on the order of 1 to 2 cm. The baseline distances determined range from 25 km to 1200 km. By repeating the measurements of the intersite vector, strain and strain rate errors were estimated. The realizable precision for intersite distance determination was estimated to be on the order of 0.5 cm at 300 km and about 1.5 cm at 1200 km. The corresponding inaccuracies for the intersite distances were larger, than is 1 cm and 3.5 cm respectively. The corresponding precision in the vertical direction was 1 cm and 3 cm.
Kahn, W. D.↗