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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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At least 487 records · Page 27

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NASA NTRS1977

Remote sensing exploration for metallic mineral resources in central Baja California

Remote sensor data (primarily LANDSAT) was analyzed by photogeologic and computer-assisted enhancement techniques to evaluate the metallic mineral potential of Baja California. Overlays were prepared at 1:1,000,000 and 1:500,000 and included known geologic relationships and mineral occurrences, lineament, drainage and structural patterns, tonal anomalies, and enhancement results. Computer-assisted enhancement and classification of the test sites was performed using the IMAGE 100 system to identify subtle tonal anomalies thought related to mineralization using known sites as analysis guides. Mineral potential maps of Baja California were generated from these analyses and the ten highest priority targets visited. Preliminary assay results (atomic absorption analysis) for the samples recovered showed moderate to high geochemical anomalies for Copper (10 of 12 samples), Zinc (3 of 12 samples) and Lead (4 of 12 samples).

Baker, R. N.↗

NASA NTRS1978

High temperature surface protection

Alloys of the MCrAlX type are the basis for high temperature surface protection systems in gas turbines. M can be one or more of Ni, Co, or Fe and X denotes a reactive metal added to enhance oxide scale adherence. The selection and formation as well as the oxidation, hot corrosion and thermal fatigue performance of MCrAlX coatings are discussed. Coatings covered range from simple aluminides formed by pack cementation to the more advanced physical vapor deposition overlay coatings and developmental plasma spray deposited thermal barrier coatings.

Levine, S. R.↗

NASA NTRS1977

A database system to support image algorithm evaluation

The design is given of an interactive image database system IMDB, which allows the user to create, retrieve, store, display, and manipulate images through the facility of a high-level, interactive image query (IQ) language. The query language IQ permits the user to define false color functions, pixel value transformations, overlay functions, zoom functions, and windows. The user manipulates the images through generic functions. The user can direct images to display devices for visual and qualitative analysis. Image histograms and pixel value distributions can also be computed to obtain a quantitative analysis of images.

Lien, Y. E.↗

NASA NTRS1978

A three-dimensional potential-flow program with a geometry package for input data generation

Information needed to run a computer program for the calculation of the potential flow about arbitrary three dimensional lifting configurations is presented. The program contains a geometry package which greatly reduces the task of preparing the input data. Starting from a very sparse set of coordinate data, the program automatically augments and redistributes the coordinates, calculates curves of intersection between components, and redistributes coordinates in the regions adjacent to the intersection curves in a suitable manner for use in the potential flow calculations. A brief summary of the program capabilities and options is given, as well as detailed instructions for the data input, a suggested structure for the program overlay, and the output for two test cases.

Halsey, N. D.↗

NASA NTRS1978

Cyclic oxidation of coated Oxide Dispersion Strengthened (ODS) alloys in high velocity gas streams at 1100 deg C

Several overlay coatings on ODS NiCrAl's were tested in Mach 1 and Mach 0.3 burner rigs to examine oxidation and thermal fatigue performance. The coatings were applied by various methods. Based on weight change, macroscopic, and metallographic observations in Mach 1 tests Nascoat 70 on TD-NiCrAl exhibited the best oxidation resistance. In Mach 0.3 tests PWA 267 and ATD-1, about equally, were the best coatings on YD-NiCrAl (Nascoat 70 was not tested in Mach 0.3 rigs).

Gedwill, M. A.↗

NASA NTRS1978

User's manual: Subsonic/supersonic advanced panel pilot code

Sufficient instructions for running the subsonic/supersonic advanced panel pilot code were developed. This software was developed as a vehicle for numerical experimentation and it should not be construed to represent a finished production program. The pilot code is based on a higher order panel method using linearly varying source and quadratically varying doublet distributions for computing both linearized supersonic and subsonic flow over arbitrary wings and bodies. This user's manual contains complete input and output descriptions. A brief description of the method is given as well as practical instructions for proper configurations modeling. Computed results are also included to demonstrate some of the capabilities of the pilot code. The computer program is written in FORTRAN IV for the SCOPE 3.4.4 operations system of the Ames CDC 7600 computer. The program uses overlay structure and thirteen disk files, and it requires approximately 132000 (Octal) central memory words.

Moran, J.↗

NASA NTRS1977

Viking 1975 Mars lander interactive computerized video stereophotogrammetry

A novel computerized interactive video stereophotogrammetry system has been developed for analysis of Viking 1975 lander imaging data. Prompt, accurate, and versatile performance is achieved. Earth-returned digital imagery data are driven from a computer to a pair of video monitors. Powerful computer support enables a photogrammetrist, stereoscopically viewing the video displays, to create diverse topographic products. Profiles, representing the intersection of any definable surface with the Martian relief, are readily generated. Vertical profiles and elevation contour maps, including stereo versions, are produced. Computer overlays of map products on stereo images aid map interpretation and permit independent quality evaluation. Slaved monitors enable parallel viewing. Maps span from the immediate foreground to the remote limits of ranging capability. Surface sampler arm specific vertical profiles enable direct reading of arm commands required for sample acquisition, rock rolling, and trenching. The ranging accuracy of plus or minus 2 cm throughout the sample area degrades to plus or minus 20 m at 100-m range.

Liebes, S., Jr.↗

NASA NTRS1978

The rain parameter diagram - Methods and applications

A rain parameter diagram is presented which displays the relationships between all rainfall parameters defined in terms of an exponential drop size distribution. Special emphasis is given to remotely measurable quantities such as radar reflectivity, microwave attenuation, and optical extinction. Although an exponential distribution is used to construct the diagram, it is shown to have general application for arbitrary size distributions and for a wide variety of rainfall-related problems. Some of the problems are: analysis of the sources of error which result from the use of empirical rainfall relations; depiction of the physical differences between different types of rainfall and of the similarity between all empirical relations which apply to the same type of rainfall; and determination of the accuracy with which remote measurements must be made to obtain accurate rain parameters. A set of overlays is shown for four common radar wavelengths and four temperatures which display the relationships between microwave attenuation and the other rainfall parameters. These diagrams can be used to determine rainfall parameters remotely in dual-measurement techniques.

Ulbrich, C. W.↗

NASA NTRS1978

Reaction diffusion in the NiCrAl and CoCrAl systems

The paper assesses the effect of overlay coating and substrate composition on the kinetics of coating depletion by interdiffusion. This is accomplished by examining the constitution, kinetics and activation energies for a series of diffusion couples primarily of the NiCrAl/Ni-10Cr or CoCrAl/Ni-10Cr type annealed at temperatures in the range 1000-1205 C for times up to 500 hr. A general procedure is developed for analyzing diffusion in multicomponent multiphase systems. It is shown that by introducing the concept of beta-source strength, which can be determined from appropriate phase diagrams, the Wagner solution for consumption of a second phase in a semiinfinite couple is successfully applied to the analysis of MCrAl couples. Thus, correlation of beta-recession rate constants with couple composition, total and diffusional activation energies, and interdiffusion coefficients are determined.

Levine, S. R.↗

NASA NTRS1979

Biocontamination and particulate detection system

A method for determining the characteristics and amount of microscopic contaminants lodged on a photographed surface is disclosed. An image enhanced full color photographic negative and print are taken of the contaminated surface. Three black and white prints are developed subsequently from red, green and blue separation filter overlays of the color negative. Both the color and three monochromatic prints are then scanned to extract in digital form a profile of any contaminant possibly existing on the surface. The resulting profiles are electronically analyzed and compared with data already stored relating to known contaminants.

Jacobs, J. M.↗

NASA NTRS1977

Current developments in SAW oscillator stability

The results reported were obtained with two port delay lines and resonators used in a simple feedback oscillator. The feedback oscillator employed inherently operates with the amplifier in a saturated condition and, therefore, the AM noise is suppressed. Consequently the dominant noise is FM. Generally, it can be concluded that for very narrow-band, or fixed-frequency applications, the resonator-type oscillator will give the best noise performance. For applications where tunability and linearity are important, the delay-line-type oscillator may give the best performance. There have been no significant improvements in oscillator temperature stability. The only two demonstrated materials for temperature stable SAW oscillators are ST-cut quartz and the SiO2/LiTaO3 overlay structure. Aging tests have been going on for the past two-and-a-half years and it has become obvious that the observed aging rates are largely related to cleaning and packaging.

Parker, T. E.↗

NASA NTRS1978

Monitoring gypsy moth defoliation by applying change detection techniques to Landsat imagery

The overall objective of a research effort at NASA's Goddard Space Flight Center is to develop and evaluate digital image processing techniques that will facilitate the assessment of the intensity and spatial distribution of forest insect damage in Northeastern U.S. forests using remotely sensed data from Landsats 1, 2 and C. Automated change detection techniques are presently being investigated as a method of isolating the areas of change in the forest canopy resulting from pest outbreaks. In order to follow the change detection approach, Landsat scene correction and overlay capabilities are utilized to provide multispectral/multitemporal image files of 'defoliation' and 'nondefoliation' forest stand conditions.

Williams, D. L.↗

NASA NTRS1979

Digital Image Display Control System, DIDCS

DIDCS is an interactive image display and manipulation system that is used for a variety of astronomical image reduction and analysis operations. The hardware system consists of a PDP 11/40 main frame with 32K of 16-bit core memory; 96K of 16-bit MOS memory; two 9 track 800 BPI tape drives; eight 2.5 million byte RKO5 type disk packs, three user terminals, and a COMTAL 8000-S display system which has sufficient memory to store and display three 512 x 512 x 8 bit images along with an overlay plane and function table for each image, a pseudo color table and the capability for displaying true color. The software system is based around the language FORTH, which will permit an open ended dictionary of user level words for image analyses and display. A description of the hardware and software systems will be presented along with examples of the types of astronomical research that are being performed. Also a short discussion of the commonality and exchange of this type of image analysis system will be given.

Fischel, D.↗

NASA NTRS1980

Eliminating underbead fissuring in superalloys

Parameters that produce high-integrity overlay welds in Incoloy-903, Incoloy-88, and Inconel-718 differ from those in conventional metal-in groove welds. Reduced weld velocity eliminates underbead crack-inducing level.

Betts, R. D.↗

NASA NTRS1979

Streakline flow visualization study of a horseshoe vortex in a large-scale, two-dimensional turbine stator cascade

Neutrally bouyant helium-filled bubbles were observed as they followed the streamlines in a horseshoe vortex system around the vane leading edge in a large scale, two dimensional, turbine stator cascade. Inlet Reynolds number, based on true chord, ranged between 100,000 to 300,000. Bubbles were introduced into the endwall boundary layer through a slot upstream of the vane leading edge. The paths of the bubbles were recorded photographically as streaklines on 16 mm movie film. Individual frames from the film were selected, and overlayed to show the details of the horseshoe vortex around the leading edge. The transport of the vortex across the passage near the leading edge is clearly seen when compared to the streaks formed by bubbles carried in the main stream. Limiting streamlines on the endwall surface were traced by the flow of oil drops.

Gaugler, R. E.↗

NASA NTRS1979

USDA analyst review of the LACIE IMAGE-100 hybrid system test

Fifty operational segments from the U.S.S.R., 40 test segments from Canada, and 24 test segments from the United States were used to provide a wide range of geographic conditions for USDA analysts during a test to determine the effectiveness of labeling single pixel training fields (dots) using Procedure 1 on the 1-100 hybrid system, and clustering and classifying on the Earth Resources Interactive Processing System. The analysts had additional on-line capabilities such as interactive dot labeling, class or cluster map overlay flickers, and flashing of all dots of equal spectral value. Results on the 1-100 hybrid system are described and analyst problems and recommendations are discussed.

Ashburn, P.↗

NASA NTRS1980

Application of snowcovered area to runoff forecasting in selected basins of the Sierra Nevada, California

The author has identified the following significant results. Direct overlay onto 1:1,000,000 prints takes about one third the time of 1:500,000 zone transfer scope analysis using transparencies, but the consistency of the transparencies reduce the time for data analysis. LANDSAT data received on transparencies is better and more easily interpreted than the near real-time data from Quick Look, or imagery from other sources such as NOAA. The greatest potential for water supply forecasting is probably in improving forecast accuracy and in expanding forecast services during the period of snowmelt. Problems of transient snow line and uncertainties in future weather are the main reasons that snow cover area appears to offer little in water supply forecast accuracy improvement during the peroid snowpack accumulation.

Brown, A. J.↗

NASA NTRS1980

An improved panel method for the solution of three-dimensional leading edge vortex flows Volume 2: User's guide and programmer's document

A computer program developed for solving the subsonic, three dimensional flow over wing-body configurations with leading edge vortex separation is presented. Instructions are given for the proper set up and input of a problem into the computer code. Program input formats and output are described, as well as the overlay structure of the program. The program is written in FORTRAN.

Tinoco, E. N.↗