SEARCH · Search NASA
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.
The author has identified the following significant results. During the winter of 1974-75, the number of transmissions dropped with lower temperatures and ceased at -20 C. During the winter of 1975-76, the same pattern occurred except that the platform ceased at slightly lower temperatures, probably due to the addition of 3, 1.5 V primary cells to the power supply. The next winter (1976-77), the same pattern occurred.
Explore the source record for details and available documents.
The author has identified the following significant results. The feasibility of transmitting hydrometric data in the LANDSAT and GOES mode and using these data operationally was demonstrated. All elements except for the GOES downlink at PASS are functioning well.
The author has identified the following significant results. The project continues to demonstrate the feasibility of transmitting hydrometric data in the LANDSAT and GOES mode and using these data operationally. All elements except for the GOES downlink at PASS are functioning well.
The author has identified the following significant results. The project continued to demonstrate the feasibility of transmitting hydrometric data in the LANDSAT and GOES mode and using these data operationally. All elements except for the GOES downlink at PASS were functioning well.
Rb-Sr isotopic data for mineral separates from a rock of the Manicouagan impact melt sheet define an isochron of age T = 214 + or - 5 (2 sigma) m.y. which agrees with the K-Ar age of 210 + or - 8 (2 sigma) calculated by Wolfe (1971). The initial Sr-87/Sr-86 ratio I is found to be 0.70991 + or - 0.00007 (2 sigma); four whole rock samples yield age-corrected I values ranging from 0.70965 to 0.71006. These high I values support the hypothesis that the melt sheet was derived by total melting of Grenville basement rocks during the impact event 214 m.y. ago.
Composite materials are discussed with reference to their mechanical and physical properties, fatigue and fracture testing and analysis, nondestructive evaluation, fabrication, and commercial applications. Particular papers are presented on such topics as analysis of mechanical strength data from hybrid laminates of glass and graphite fibers, graphite-aluminum composites, the mechanical behavior of molybdenum-reinforced metal composites, and composite laminate application in magnetic fusion energy superconducting magnet systems.
The auroral-electrojet zone covers three quarters of Manitoba and consequently, solar storms strongly affect transmission lines. Harmonics are generated at transformers due to the saturation of their cores by induced currents, and the level of harmonics produced may cause malfunction of control relays, and yield unacceptable distortions in normal ac waveforms. The expected effects of long ac transmission systems were studied with emphasis on a 500 kv line to be built from Winnipeg to Minneapolis-St. Paul. Spectral analysis of induced current records from Manitoba Hydro's LaVerendrye station and magnetograms from IMS stations in Manitoba were used along with results of Campbell's work on the Alaskan pipeline induction problem (1978) in order to predict periodic and surge currents. It is concluded that the surge currents will produce significant levels of harmonics and corresponding operating problems during magnetic storms.
The objectives and results of several studies using the Canadian long baseline interferometry system (LBI) are presented. The precision of measurements from radio telescopes at the Algonquin Radio Observatory (ARO), Lake Traverse, Ontario; the Owens Valley Radio Observatory (OVRO), Big Pine, California; and the Chilbolton Observatory (CHIL), Chilbolton, England, is discussed. Also, since LBI is insensitive to the uncertainty in the geocentric gravitational constant, it is a very useful technique for determining the scales of the coordinate systems used by other precise techniques. Beginning in May 1977, a number of LBI observing sessions were accompanied by simultaneous satellite Doppler observations. The baseline components obtained from the satellite Doppler observations were compared to the LBI values. The weighted mean scale bias of the NSWC 9Z-2 satellite Doppler coordinate system relative to the LBI system was found to be 0.42 + or - 0.05 PPM. The weighted mean difference in the origin of longitude was found to be 0.87 sec + or - 0.01 while the difference in declination origin was found to be 0.06 sec + or - 0.01.
The NASA terminal configured vehicle B-737 was flown in support of the world wide FAA demonstration of the time reference scanning beam microwave landing system. A summary of the flight performance of the TCV airplane during demonstration automatic approaches and landings while utilizing TRSB/MLS guidance is presented. The TRSB/MLS provided the terminal area guidance necessary for automatically flying curved, noise abatement type approaches and landings with short finals.
Analysis of Investigator B tapes was extended to use a statistical screening of individual data points in each grid cell over the map area. The mean value of data from each cell was computed and all data values more than 4nT from the mean were rejected. The revised mean and standard deviation was computed. The average standard deviation for all map grid cells was 1.4nT for the scalar anomaly map and about 2nT for the vector component anomaly maps. At this stage, the grid cell is larger and spatial resolution lower for the vector maps than for the scalar maps, because the vector components are considerably more disturbed and more data points were rejected. An approach for altitude adjustment is in progress so that corrections can be made and data reduction procede. To evaluate the use of scalar and vector MAGSAT data for the production of regional magnetic charts, charts of the north, east, vertical, and scalar field derived from MAGSAT and from Canadian aeromagnetic data were compared. It appears possible to retrieve crustal signals from the horizontal vector components despite external disturbance fields at high latitude.
Correlations between the MAGSAT scalar anomaly map produced at the Earth Physics ranch and other geophysical and geological data reveal relationships between high magnetic field and some metamorphic grade shields, as well as between low magnetic field and shield regions of lower metamorphic grade. An intriguing contrast exists between the broad low anomaly field over the Nasen-Gakkel Ridge (a spreading plate margin) and the high anomaly field over Iceland (part of a spreading margin). Both regions have high heat flow, and presumably thin magnetic crust. This indicates that Iceland is quite anomalous in its magnetic character, and possible similarities with the Alpha Ridge are suggested. Interesting correlations exist between MAGSAT anomalies around the North Atlantic, after reconstructing the fit of continents into a prerifting configuration. These correlations suggest that several orogenies in that region have not completely destroyed an ancient magnetization formed in high grade Precambrian rocks.
A bilateral synthetic aperture radar (SAR) satellite program is defined. The studies include addressing the requirements supporting a SAR mission posed by a number of disciplines including science and operations in sea ice covered waters. Sea ice research problems such as ice information and total mission requirements, the mission components, the radar engineering parameters, and an approach to the transition of spacecraft SAR from a research to an operational tool were investigated.
Problems related to combustion generated pollution are explored, taking into account the mechanism of NO formation from nitrogen compounds in hydrogen flames studied by laser fluorescence, the structure and similarity of nitric oxide production in turbulent diffusion flames, the effect of steam addition on NO formation, and the formation of NO2 by laminar flames. Other topics considered are concerned with propellant combustion, fluidized bed combustion, the combustion of droplets and sprays, premixed flame studies, fire studies, and flame stabilization. Attention is also given to coal flammability, chemical kinetics, turbulent combustion, soot, coal combustion, the modeling of combustion processes, combustion diagnostics, detonations and explosions, ignition, internal combustion engines, combustion studies, and furnaces.
Research into an approach for altitude adjustments for MAGSAT or similar data acquired over a range of altitudes is progressing. The technique shows promise not only in the production of refined anomaly maps but also in the derivation of regional charts of the magnetic elements from satellite and ground data. Correlations between MAGSAT anomalies and other geophysical and geological data are being explored further and quantitative modelling of some features has begun. The form of some anomalies may change as the maps are refined by the technique being developed. Emphasis is being given to the Canadian regions, although analogous features elsewhere are being considered.
Consideration is being given to representing the magnetic field in the area 40 deg N to 83 deg N by means of functions in spherical coordinates. A solution to Laplace's equation for the magnetic potential over a restricted area was found, and programming and testing are currently being carried out. Magnetic anomaly modelling is proceeding. The program SPHERE, which was adapted to function correctly on the Cyber computer, is now operational, for deriving gravity and magnetic models in a spherical coordinate system.
Explore the source record for details and available documents.
The measurement of aerosols from space is discussed, taking into account the role of aerosols in climate, instrumentation and further measurement systems, retrieval procedures, measurements and observations, ground truth measurements, and effects on remote sensing and on climate. Aspects of ozone variability in the middle atmosphere are explored, giving attention to the quasi-biennial oscillation in equatorial stratospheric temperatures and total ozone, global pictures on the ozone field from high altitudes from DE-1, measurements of atmospheric ozone from aircraft and from balloons, a mesospheric ozone profile at sunset, periodic and aperiodic ozone variations in the middle and upper stratosphere, solar eclipse induced variations in mesospheric ozone concentrations, and solar UV and ozone balloon measurements. The determination of aerosol optical depth is considered along with a method for estimating cross radiance.