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.
IR spectroscopy, determining relative populations of carbon dioxide vibrational energy levels by comparing emission intensities
Apollo 11 lunar rock mineralogy, examining petrographic and chemical features by light microscopy, electron microprobe microanalysis and detector system
Photoelectric photometer measurements of stellar interferometer fringes strength by light modulation
Multistage two player zero-sum games with state determined by difference equations, deriving optimal strategy pair satisfying saddle point condition
Human perceptual motor skill development in tracking performance, using feedback control system gain and effective time delay as measures
Remote sensing as a tool in a waste management program is discussed. By monitoring both the pollution sources and the environmental quality, the interaction between the components of the exturaine system was observed. The need for in situ sampling is reduced with the development of improved calibrated, multichannel sensors. Remote sensing is used for: (1) pollution source determination, (2) mapping the influence zone of the waste source on water quality parameters, and (3) estimating the magnitude of the water quality parameters. Diffusion coefficients and circulation patterns can also be determined by remote sensing, along with subtle changes in vegetative patterns and density.
The solubility and/or swelling of cured epoxy resins was studied using the solubility parameter method. Determination of solubility parameters were found in order to select solvents for solvent-assisted degradation of cured epoxy polymers used in spacecraft. A method for improving recovery of seeded spores is suggested for assay of buried contaminants. Three commercial epoxy resins were cured using four different alkyl amines. For each resin-amine combination, three levels of amine were used, corresponding to 1/3, 2/3, and all of the amine required to react with the oxirane groups of the resin. The solubility parameters of the 36 resulting model compounds were determined in poorly and moderately hydrogen-bonded solvents. No strongly hydrogen-bonded solvents caused dissolution or swelling. The tolerance of cured resins is discussed in terms of polymer structure.
Methods of analyzing bird migration by using tracking radar are discussed. The procedure for assessing the rate of bird passage is described. Three topics are presented concerning the grouping of nocturnal migrants, the velocity of migratory flight, and identification of species by radar echoes. The height and volume of migration under different weather conditions are examined. The methods for studying the directions of migration and the correlation between winds and the height and direction of migrating birds are presented.
The use of IR aerial photographs for determining the dynamic characteristics of evapotranspiration at the Gila River Test Site is discussed. Evapotranspiration was measured as a function of plant volume, surface conditions, soil moisture storage, and ground water levels.
Solubilization studies were carried out on various cured silicone resins. A solvent spectrum was prepared. It was found that complete dissolution of cured silicone resins could be achieved without extensive physical degradation of samples. Based on the solubilization results, amine solvents were selected for spore viability studies.
The discrepancy between the masses of Cepheid variables deduced from evolution theory and pulsation theory is examined. The effect of input physics on evolutionary tracks is first discussed; in particular, changes in the opacity are considered. The sensitivity of pulsation masses to opacity changes and to the ascribed values of luminosity and effective temperature are then analyzed. The Cepheid mass discrepancy is discussed in the light of the results already obtained. Other astronomical evidence, including the mass-luminosity relation for main sequence stars, the solar neutrino flux, and cluster ages are also considered in an attempt to determine the most likely source of error in the event that substantial mass loss has not occurred.
Description of methods developed for the preparation of N-TFA-S(-)prolyl chloride and for synthesizing from it N-TFA-S-prolyl(and S)-leucine methyl ester diastereomers without detectible racemization. These diastereomers prepared by these methods were subjected to GC analyses under conditions permitting baseline separation of two diastereomeric peaks, while peak areas were measured with an electronic digital integrator. Under these conditions, it was found that the known enantiomeric compositions could be duplicated experimentally to an absolute error of only 0.0 to 0.6% over the entire composition range.
Explore the source record for details and available documents.
A tracking test battery has been applied in a drug trail designed to compare the efficacy of L-DOPA and amantadine to that of L-DOPA and placebo in the treatment of 28 patients with Parkinson's disease. The drug trial provided an ideal opportunity for objectively evaluating the usefulness of tracking tests in assessing changes in neurologic function. Evaluating changes in patient performance resulting from disease progression and controlled clinical trials is of great importance in establishing effective treatment programs.
A combined WDS-EDS system obviates the severe X-ray peak overlap problems encountered with Na, Mg, Al and Si common to pure EDS systems. By application of easily measured empirical correction factors for pulse pile-up and peak overlaps which are normally observed in the analysis of silicate minerals, the accuracy of analysis is comparable with that expected for WDS electron microprobe analyses. The continuum backgrounds are subtracted for the spectra by a spline fitting technique based on integrated intensities between the peaks. The preprocessed data are then reduced to chemical analyses by existing data reduction programs.
The differential energy spectra of cosmic ray protons and He nuclei were measured at energies up to 315 MeV/nucleon using balloon-borne and satellite-borne instruments. These spectra are presented for solar quiet times for the years 1966 through 1970. The data analysis is verified by extensive accelerator calibrations of the detector systems and by calculations and measurements of the production of secondary protons in the atmosphere. The spectra of protons and He nuclei in this energy range are dominated by the solar modulation of the local interstellar spectra. Numerical solutions to the transport equation are presented for a wide range of parameters.
An investigation was made to determine (1) sporicidal properties of amine solvents that solubilize silicon resins, (2) recovery properties of a silicon potting compound (RTV 41) used in spacecraft, and (3) viability of spores during chemical curing of the potting compound. Results show that: (1) spores do remain viable during RTV 41 silicon potting chemical curing, and (2) spore recovery from cured silicon potting compound RTV 41 is very high when silicon rubber is dissolved in butylamine and series dilution with benzene prior to plate curing.
A recommended imaging system is outlined for use aboard the Outer Planet Grand Tour Explorer. The system features the high angular resolution capacity necessary to accommodate large encounter distances, and to satisfy the demand for a reasonable amount of time coverage. Specifications for all components within the system are provided in detail.