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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 NTRS1971

Empirical solar continuum models

Empirical solar photosphere continuum models, calculating temperature distribution for absolute intensities at center and limb darkening ratios

Remo, J. L.↗
NASA NTRS1972

Recurrent active regions related to metric radio continuum emissions and the interplanetary magnetic sector structure

Active heliographic longitudes at the sun are investigated by using the observational data for long-lived metric continuum noise sources. It is shown that, for the period from 1963 to 1969, the number of such longitudes was four in general and these longitudes were very stable for this radio activity since 1963. A discussion is given on the relationship between those longitudes and the sector structure of the interplanetary magnetic field.

Sakurai, K.↗
NASA NTRS1972

Turbulent properties of a continuum plasma in shear flow.

The detailed turbulence structure of a weakly ionized, continuum plasma is analyzed. This analysis, when extended to high Reynolds number turbulent boundary layers, shows that the ratio of the electron to ion saturation currents decreases by an order of magnitude as compared to the laminar case.

Marcisz, T. J.↗
NASA NTRS1972

Infrared studies of galactic nebulae. IV - Continuum and line radiation from planetary nebulae.

Observations are reported of the detection of IR radiation from several planetary nebulae not previously known to be radiating at these wavelengths. Broad spectral bandwidth observations indicate that ir radiation in excess of that expected from atomic processes is a common phenomenon among these objects. Investigations with narrow spectral bandwidth show that in a few cases the energy in the 10.52-micron line is a significant fraction of the total energy observed in the broad-band measurements and in other cases a relatively small fraction of the total radiation. Other observations on two sources with narrow spectral bandwidth adjacent to the 10.52-micron line indicate that at these wavelengths a true continuum of radiation exists as well as lines. The results are discussed in relation to visual and radio-wavelength data.

Gillett, F. C.↗
NASA NTRS1973

Spectral line and continuum studies using Haystack antenna

During the last half of 1972, the Haystack antenna was utilized 88% of the time. Of this useful time, 81% was devoted to radio astronomy investigations, 8% was spent on radar-related research and 11% was scheduled for maintenance and system improvements. Thirteen programs were completed of which 10 were spectral-line studies involving primarily recombination lines and H2O vapor investigations. The others involved 2 cm and 1.3 cm continuum observations. Fifteen new programs were accepted and the currently active radio observing programs totalled 24 as of 31 December 1973. The last radar measurements in the lunar topography program have now been completed. Radar activity, including measurements on Mercury, Venus and synchronous satellites has continued.

Source record↗
NASA NTRS1972

High angular resolution absolute intensity of the solar continuum from 1400 to 1790 A.

Absolute intensities of the solar UV continuum from 1400 to 1790 A have been measured from rocket spectra taken on August 13, 1970. The spectra had an angular resolution of 2 arc sec by 1 arc min, and the pointing accuracy of the instrument was plus or minus 2 arc sec. This permits us to study the center-to-limb variation of the intensity with a spatial resolution of 2 arc sec. Four positions on the solar disk have been studied corresponding to values of cos theta = 0.12, 0.22, 0.28 and 0.72, where theta is the heliocentric position angle. The measurements give higher values for the intensity than recent photoelectric measurement, but are in good agreement with the intensities of Widing et al.

Brueckner, G. E.↗
NASA NTRS1973

Turbulent shear flow of continuum plasma.

The turbulence structure of weakly ionized, continuum plasma is analyzed with emphasis on the turbulent fluctuation and the transport properties of the ionized species. The mean gradients of the velocity and ionized-species concentrations are considered to be uniform. It is assumed that the turbulence Reynolds number is small and that the turbulence field is homogeneous in order to close the dynamic equations of turbulence. It was found that the ratio of the Debye shielding length to the local integral scale of turbulence must be sufficiently small in order for the detailed quasi-neutrality to prevail. The condition of the detailed quasi-neutrality is necessary, in addition to the equal mean concentrations of electrons and ions, in order for the turbulence properties involving the electrons to be the same as those involving the ions.

Chung, P. M.↗