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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.
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The main objectives are formulated around a four pronged work approach, consisting of tasks related to: image processing and analysis of LANDSAT thematic mapping; numerical modeling of circulation and dispersion; hydrographic and spectral radiation field sampling/ground truth data collection; and special efforts to focus the investigation on turbid coastal/estuarine fronts.
Operationally acquired Thematic Mapper and experimental MOMS-01 data are evaluated quantitatively concerning the systems spectral response and performance for geoscientific applications. Results show the two instruments to be similar in the spectral bands compared. Although the MOMS scanner has a smaller IFOV, it has a lower modulation transfer function performance for small, low contrast features as compared to Thematic Mapper. This deficiency does not only occur when MOMS was switched to the low gain mode. It is due to the CD arrays used (ITEK CCPD 1728).
The Garlock and Death Valley fault zones in SE California are two active strike-slip faults coming together on the east side of the Avawatz Mtns. The kinematics of this intersection, and the possible continuation of either fault zone, are being investigated using a combination of field mapping, and processing and interpretation of remotely sensed image data. Regional and local relationships are derivable from Thematic Mapper data (30 m resolution), including discrimination and relative age dating of alluvial fans, bedrock mapping, and fault mapping. Aircraft data provide higher spatial resolution over more limited areas. Hypotheses being considered are: (1) the Garlock fault extends east of the intersection; (2) the Garlock fault terminates at the intersection and the Death Valley fault continues southeastward; and (3) the Garlock fault has been offset right laterally by the Death Valley fault which continues to the southeast. Preliminary work indicates that the first hypothesis is invalid. From kinematic considerations, image analysis, and field work the third hypothesis is favored. The projected continuation of the Death Valley zone defines the boundary between the Mojave crustal block and the Basin and Range block.
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He II vapor-liquid phase separation (VLPS) is discussed, with emphasis on fluid-related transport phenomena. The VLPS system has been studied for both linear and nonlinear regimes, demonstrating that well-defined convection patterns exist in porous plug phase separators. In the second part, other components based on the thermomechanical effect are discussed in the limit of ideal conditions. Examples considered include the heat pipe transfer of zero net mass flow, liquid transfer pumps based on the fountain effect, mechanocaloric devices for cooling purposes, and He II vortex refrigerators.
Ophiolite terrains, considered to be the onland occurrences of oceanic crust, host a number of types of mineral deposits: volcanogenic massive sulfides, podiform chromite, and asbestos. Thematic Mapper data for the Semail Ophiolite in Oman were used to separate and map ultramafic lithologies hosting these deposits, including identification of the components of the extrusive volcanic sequence, mapping of serpentinization due to various tectonic processes, and direct identification of gossans. Thematic Mapper data were found to be extremely effective for mapping in this terrain due to the excellent spatial resolution and the presence of spectral bands which allow separation of the pertinent mineralogically caused spectral features associated with the rock types of interest.
Energy transfer processes occurring between atomic, ionic, or molecular systems are very widespread in nature. The applications of such processes range form radiation physics and chemistry to biology. In the field of laser physics, energy transfer processes have been used to extend the lasing range, increase the output efficiency, and influence the spectral and temporal characteristics of the output pulses of energy transfer dye lasers or solid-state laser materials. Thus in the development of solid state lasers, it is important to investigate the basic energy transfer (ET) mechanisms and processes in order to gain detailed knowledge so that successful technical utilization can be achieved. The aim of the present research is to measure the ET rate from a given manifold associated with the chromium sensitizer atom to a given manifold in the holmium activator atom via the thulium transfer atom, in the Ho:Cr:YAG laser material.
Kinematic relationships at the intersection of the southern Death Valley and Garlock fault zones were examined to identify and delineate the eastern structural boundary between the Mojave and the Basin and Range geologic terrains, and to construct a model for the evolution of this boundary through time. In order to accomplish this, satellite imagery was combined with field investigations to study six areas in the vicinity of the intersection, or possible extensions, of the fault zones. The information gathered from these areas allows the test of various hypotheses that were proposed to explain the interaction between the Death Valley and Garlock fault zones.
An estimate was made toward a continent wide population of penguins. The results indicate that Thematic Mapper data can be used to identify penguin rookeries due to the unique reflectance properties of guano. Strong correlations exist between nesting populations and rookery area occupied by the birds. These correlations allow estimation of the number of nesting pairs in colonies. The success of remote sensing and biometric analyses leads one to believe that a continent wide estimate of penguin populations is possible based on a timely sample employing ground based and remote sensing techniques. Satellite remote sensing along the coastline may well locate previously undiscovered penguin nesting sites, or locate rookeries which have been assumed to exist for over a half century, but never located. Observations which found that penguins are one of the most sensitive elements in the complex of Southern Ocean ecosystems motivated this study.
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The SPS product, Classic-Ada, is a software tool that supports object-oriented Ada programming with powerful inheritance and dynamic binding. Object Oriented Design (OOD) is an easy, natural development paradigm, but it is not supported by Ada. Following the DOD Ada mandate, SPS developed Classic-Ada to provide a tool which supports OOD and implements code in Ada. It consists of a design language, a code generator and a toolset. As a design language, Classic-Ada supports the object-oriented principles of information hiding, data abstraction, dynamic binding, and inheritance. It also supports natural reuse and incremental development through inheritance, code factoring, and Ada, Classic-Ada, dynamic binding and static binding in the same program. Only nine new constructs were added to Ada to provide object-oriented design capabilities. The Classic-Ada code generator translates user application code into fully compliant, ready-to-run, standard Ada. The Classic-Ada toolset is fully supported by SPS and consists of an object generator, a builder, a dictionary manager, and a reporter. Demonstrations of Classic-Ada and the Classic-Ada Browser were given at the workshop.
The influence of reinforcement size, volume fraction, and matrix deformation behavior on room and elevated temperature strength, and the fracture toughness of metal matrix composites of both pure aluminum and Al(4 percent)Cu(1.5 percent)Mg with 0 to 15 vol percent TiB2 were examined. Higher TiB2 volume fractions increased the tensile yield strength both at room and elevated temperatures, and reduced the elongation to fracture. Tensile tests also indicate that small particles provided a greater increase in strength for a given volume fraction than larger particles, whereas elongation to fracture appeared to be insensitive to reinforcement size. The fracture toughness of the Al(4 percent)Cu(1.5 percent)Mg alloys decreased rapidly with TiB2 additions of 0 to 5 vol percent and more slowly with TiB2 additions of 5 to 15 vol percent. Fracture toughness appears to be independent of TiB2 particle size. The isothermal-aging response of the precipitation strengthened Al(4 percent)Cu(1.5 percent)Mg alloys was not altered by the presence of TiB2.
Rare earth lasers were in existance since the first laser was developed. The primary lasing elements for the class of lasers in the infrared was neodymium and chromium. However, the need for eye safe lasers in the mid-infrared range has prompted an enormous amount of research to the use of other elements. Holmium was investigated extensively as the source of infrared radiation for atmospheric research as well as medical research. The results and procedure are briefly discussed.
Infrared radiance measurements were acquired from a radiometer on the NASA ER-2 during a coincident LANDSAT 5 overpass on 28 Oct. 1986 as part of the FIRE Cirrus IFO in the vicinity of Lake Michigan. A comparative study is made to infer microphysical properties of the cirrus cloud field. Radiances are derived from the image by convolving the ER-2 radiometer's effective field of view along the flight path. A multistream radiative transfer model is used to account for the differences in spectral bandwidths, 10.40 to 12.50 microns for the LANDSAT band and 9.90 to 10.87 microns for the radiometer.
The influence of reinforcement size, volume fraction, and matrix deformation behavior on room and elevated temperature strength; the fracture toughness; and the fatigue crack growth rate of metal matrix composites of Al-4(pct)Cu-1.5(pct)Mg with TiB2 were examined. The influence of reinforcement volume fraction was also examined for pure aluminum with TiB2. Higher TiB2 volume fractions increased the tensile yield strength at both room and elevated temperatures, and reduced the elongation to fracture. Tensile tests also indicate that small particles provided a greater increase in strength for a given volume fraction than larger particles, whereas elongation to fracture appeared to be insensitive to reinforcement size. Interparticle spacing appears to be the factor that controls the strength of these alloys, with the exact nature of the dependence relying on the nature of dislocation slip in the matrix (planar vs. diffuse). The isothermal aging response of the precipitation strengthened Al-4(pct)Cu-1.5(pct)Mg alloys was not accelerated by the presence of TiB2. Cold work prior to artificial aging created additional geometrically necessary dislocations which serve as heterogeneous nucleation sites leading to accelerated aging, a finer precipitate size, and an increase in the strength of the alloy.