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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 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS1995

Positions and Intensities in the 3v2/v2+v4 Vibrational System of 14NH3 Near 4 micron meters

Ammonia is the fourth most abundant constituent in the atmospheres of Jupiter and Saturn, after hydrogen, helium and methane. This relative abundance is attested by the presence in the infrared planetary spectra of many absorption features observed in the range of fundamental bands and also in the higher bands. Reported are experimental line positions and intensities of selected ammonia bands.

ammonia Jupiter Saturn spectroscopy planetary gass↗
NASA NTRS1981

Atlas of absorption lines from 0 to 17 900 cm(-1)

Plots of absorption line strength versus line position for wavenumbers from 0 to 17,900 cm(-1) are shown for 20 atmospheric gases (H2O, CO2, O3, N2O, CO, CH4, O2, NO, SO2, NO2, NH3, HNO3, OH, HF, HCl, HBr, HI, ClO, OCS, H2CO). Also shown are similar plots of lower-state energy values for adsorption lines for the strongly adsorbing atmospheric gases (H2O, CO2, O3, and CH4) for wavenumbers from 0 to 5000 cm(-1).

Park, J. H.↗
NASA NTRS1990

Line parameters for ozone hot bands in the 4.8-micron spectral region

Line positions, intensities, and lower-state energies have been calculated for nine hot bands of (O-16)3 in the 4.8-micron spectral region using improved spectroscopic parameters deduced in recent high-resolution laboratory studies. The good quality of the hot-band parameters has been verified through comparisons of line-by-line simulations with 0.005/cm-resolution laboratory spectra of ozone. The present work and the line parameters calculated for the main bands by Pickett et al. (1988) provide a complete update of ozone spectroscopic parameters in the 4.8 micron region.

Camy-Peyret, Claude↗
NASA NTRS1988

Advanced infrared astronomy

This task supports the application of infrared heterodyne and Fourier transform spectroscopy to ultra-high resolution studies of molecular constituents of planetary astomspheres and cometary comae. High spectral and spatial resolutions are especially useful for detection and study of localized, non-thermal phenomena in low temperature and low density regions, for detection of trace constituents and for measurement of winds and dynamical phenomena such as thermal tides. Measurement and analysis of individual spectial lines permits retrieval of atmospheric molecular abundances and temperatures and thus, information on local photochemical processes. Determination of absolute line positions to better than 10 to the minus eighth power permits direct measurements of gas velocity to a few meters/sec. Observations are made from ground based heterodyne spectrometers at the Kitt Peak McMath solar telescope and from the NASA infrared Telescope Facility on Mauna Kea, Hawaii. Wind velocities at 110km altitude on Venus were extracted approximately 1 m/sec from measurements of non-thermal emission cores of 10.3 micron CO2 lines. Results indicate a subsolar to antisolar circulationwith a small zonal retrograde component.

Kostiuk, T.↗
NASA NTRS1994

Extreme ultraviolet spectrum of a solar active region from SERTS

We present wavelengths and absolute intensities for 243 emission lines from a single active region observed by the Solar Extreme Ultraviolet (EUV) Rocket Telescope and Spectrograph (SERTS) on 1989 May 5. For this catalog, the imaged spectra have been spatially averaged over a field of view 7 sec x 276 sec cutting through the center of AR5464 at S18 W45. Wavelength coverage is 170-450 A with a spectral resolution approaching 10,000. Most of the line positions are determined to 5 mA or better, representing the highest accuracy yet obtained for solar wavelengths throughout this spectral interval. The relative photometric calibration of the instrument is good to +/- 20% over its first-order range, and has been placed onto an absolute scale that should be correct to within a factor less than 2. Where known, identifications, atomic transitions and formation temperatures are also given. The identified lines arise from temperatures that cover the range log T greater than or equal to 4.7 and less than or equal to 6.8, providing information about the Sun's corona and upper transition region. Upper limits to the intensity of any emission line not included here can be estimated from the measured instrumental sensitivity. This averaged EUV spectrum should prove useful as a source of accurate wavelengths and intensities for emission characteristic of the high-temperature plasma associated with a solar active region and small subflare.

Thomas, Roger J.↗
NASA NTRS1975

Positive isolation disconnect

A positive isolation disconnect was developed for component replacement in serviced liquid and gaseous spacecraft systems. Initially a survey of feasible concepts was made to determine the optimum method for fluid isolation, sealing techniques, coupling concepts, and foolproofing techniques. The top concepts were then further evaluated, including the fabrication of a semifunctional model. After all tradeoff analyses were made, a final configuration was designed and fabricated for development testing. This resulted in a 6.35 mm (1/4 inch) line and 12.7 mm (1/2 inch) line positive isolation disconnect, each unit consisting of two coupled disconnect halves, each capable of fluid isolation with essentially zero clearance between them for zero leakage upon disconnect half disengagement. An interlocking foolproofing technique was incorporated that prevents uncoupling of disconnect halves prior to fluid isolation.

Rosener, A. A.↗
NASA NTRS1972

Infrared spectra of CO2 in the atmospheres of Earth and Venus

A theoretical calculation was made of the CO2 infrared spectra of Earth and Venus atmospheres. The calculations cover line intensity, line shape, and line position. Theoretical results were compared with those observed by Nimbus 3 satellite and were found to be in reasonable agreement.

Maguire, W. C.↗
NASA NTRS1973

Continuous liquid level measurements with time-domain reflectometry

Description of the basic principles of radar measurements of cryogenic liquid levels in storage vessels by time-domain reflectometry. The probe consists of a right circular coaxial transmission line positioned vertically in the storage vessel and having holes drilled in the outer conductor to permit penetration of the liquid into the annular gap. RF pulses transmitted through the probe are reflected at liquid/gas interface and returned for sampling at the input. The measured delay of the return pulse is displayed as the level of liquid in the vessel.

Cruz, J. E.↗
NASA NTRS1974

X-ray electron study of lunar regolith from the Sea of Fertility and the Sea of Tranquillity

X-ray electron spectra were obtained of the 2p-levels of Fe, Ti, Si, Al, and Mg, and of the 1s-level in lunar regolith from the Sea of Fertility and the Sea of Tranquillity. The spectra of the same elements were recorded for approximately 30 rock forming minerals, oceanic gabbro, meteoritic eucrite, and several iron meteorites. Analysis of the results based on line positions showed that all the elements studied have the usual degrees of oxidation, and that oxygen atoms are their nearest neighbors. The predominant coordination number of Al is 4. Analysis and comparison of the Fe2p spectra in regolith, various iron meteorites, and stainless steel leads to these conclusions: Metallic iron in lunar regolith is in a highly dispersed state and is unusually stable with respect to oxidation by the oxygen of the earth's atmosphere.

Vinogradov, A. P.↗
NASA NTRS1974

The silicon monoxide radical and the atmosphere of alpha Orionis

We present new molecular constants, line positions, and transition probabilities for the first-overtone vibration-rotation bands in the X 1 Sigma+ electronic ground state of SiO, together with an estimate of the SiO abundance and silicon isotope ratios in the atmosphere of alpha Ori.

Beer, R.↗
NASA NTRS1977

Comparison of H alpha synoptic charts with the large-scale solar magnetic field as observed at Stanford

Two methods of observing the neutral line of the large-scale photospheric magnetic field are compared: (1) neutral line positions inferred from H alpha photographs and (2) observations of the photospheric magnetic field made with low spatial resolution (3 arc min.) and high sensitivity using the Stanford magnetograph. The comparison is found to be very favorable.

Duvall, T. L., Jr.↗
NASA NTRS1977

On the 6825 A band of methane as observed in Uranus and Neptune

A high-resolution spectrum of the series of lines near 6825 A presumably due to CH4 has been obtained for Uranus. The line spacings are in agreement with the previous observations of Owen (1966), Bergstralh (1975), and Belton and Hayes (1975) but not with the laboratory observations reported by Lutz and Owen (1976). It is proposed that the transitions identified by Lutz and Owen are not correlated one-to-one with those features observed in the planets. Wavelength differences of up to 0.8 A are found between the laboratory and planetary features, where the resolving power allows one to specify the line positions to better than + or - 0.07 A. The spectrum obtained for Neptune is in essential agreement with that for Uranus.

Gelfand, J.↗
NASA NTRS1978

High resolution spectral measurement of the HNO3 11.3-micron band using tunable diode lasers

High resolution spectra in the region of the 2-nu9 band of nitric acid have been obtained for selected portions of the HNO3 spectrum using tunable diode laser techniques. Continuous spectra are presented from 891.25/cm to 898.77/cm, with a spectral resolution less than or equal to 0.001/cm (30 MHz). Absolute line intensities and line positions are presented. Absolute wavelength calibration was obtained by frequency mixing the diode laser with a C(13)O2(16) isotope laser. Self and foreign gas (N2) broadening coefficients were iteratively calculated from the experimental data and were determined.

Brockman, P.↗
NASA NTRS1977

Comparison of H-alpha synoptic charts with the large-scale solar magnetic field as observed at Stanford

Two methods of observing the neutral line of the large-scale photospheric magnetic field are compared: neutral line positions inferred from H-alpha photographs (McIntosh and Nolte, 1975) and observations of the photospheric magnetic field made with low spatial resolution (three minutes) and high sensitivity using the Stanford magnetograph. The comparison is found to be very favorable.

Duvall, T. L., Jr.↗
NASA NTRS1978

Observation of the 63 micron (0 1) emission line in the Orion and Omega Nebulae

The 63 micron fine structure transition P4 : 3Pl yields 3P2 for neutral atomic oxygen was obtained during a series of flights at an altitude of approximately 13.7 km. In the Orion Nebula (M42), the observed line strength was 8 x 10 to the minus 15 power watt cm/2 which is estimated to be approximately 0.3 o/o of the energy radiated at all wavelengths. For the Omega Nebulae (M17), the line strength was 2.4 x 10 to the minus 15 power watt cm/2, and the fraction of the total radiated power was slightly higher. These figures refer to a 4' x 6' field of view centered on the peak for infrared emission from each source. The uncertainty in the line strength is approximately 50% and is caused by variable water vapor absorption along the flight path of the airplane. The line position estimate is 63.2 micron (+0.1, -0.2) micron. The prime uncertainty is due to the uncertain position of the (0 I) emitting regions in the field of view.

Melnick, G.↗