Search NASA⌕ Search

SEARCH · Search NASA

Results for “interior”

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.

At least 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Magnetism and the interior of the moon

The application of lunar magnetic field measurements to the study of properties of the lunar crust and deep interior is reviewed. Following a brief description of lunar magnetometers and the lunar magnetic environment, measurements of lunar remanent fields and their interaction with the solar plasma are discussed. The magnetization induction mode is considered with reference to lunar magnetic permeability and iron abundance calculations. Finally, electrical conductivity and temperature calculations from analyses of poloidal induction, for data taken in both the solar wind and in the geomagnetic tail, are reviewed.

Dyal, P.↗
NASA NTRS1973

Moonquakes, meteoroids, and the state of the lunar interior

Analysis of data returned from the four stations of the Apollo Seismic Network has revealed that the lunar interior can be divided into two major zones: a rigid, dynamically inactive outer shell, about 1000 km thick (the lunar lithosphere); and a relatively weak central zone (the lunar asthenosphere) in which partial melting is probable. The transition between these two zones is gradual. Seismic activity within the moon is far below that of the earth. The small moonquakes that do occur originate near the base of the lithosphere, and appear to fall within two major belts. Tidal energy appears to be an important, if not the dominant, source of energy released as moonquakes. A secular component of moonquake energy release may result from slight thermal expansion or contraction of the moon, weak convection in the asthenosphere, or secular recession of the moon from the earth. Lack of shallow moonquake activity implies that the moon is neither expanding nor contracting at an appreciable rate at present.

Latham, G.↗
NASA NTRS1974

Deep lunar interior inferred from recent seismic data

Analysis of recent data from lunar seismic events shows significant deviations of P- and S-wave travel times from those expected if the lunar interior were homogeneous below the crust. The interpretation of these data results in a lunar model consisting of at least four and possibly five distinguishable zones whose probable characteristics are discussed.

Nakamura, Y.↗
NASA NTRS1974

Lunar igneous rocks and the nature of the lunar interior

Lunar igneous rocks are interpreted, which can give useful information about mineral assemblages and mineral chemistry as a function of depth in the lunar interior. Terra rocks, though intensely brecciated, reveal, in their chemistry, evidence for a magmatic history. Partial melting of feldspathic lunar crustal material occurred in the interval 4.6 to 3.9 gy. Melting of ilmenite-bearing cumulates at depths near 100 km produced parent magmas for Apollo 11 and 17 titaniferous mare basalts in the interval 3.8 to 3.6 gy. Melting of ilmenite-free olivine pyroxenites at depths greater than 200 km produced low-titanium mare basalts in the interval 3.4 to 3.1 gy. No younger igneous rocks have yet been recognized among the lunar samples and present-day melting seems to be limited to depths greater than 1000 km.

Hays, J. F.↗
NASA NTRS1974

The interior structure of Jupiter (consequences of Pioneer 10 data)

Models of the Jovian interiors are based on theoretical equations of state of hydrogen and helium supported by a few experimental points and an observed parameter such as oblateness, gravitational coefficients, heat emission, and magnetic fields. The models fall into three categories: (1) those which assume a uniform and rather low H2/He ratio throughout the planet, (2) those in which this ratio is solar and thus higher and (3) those which take into account the lack of complete miscibility of the two elements in the condensed state. Recent values of the observed parameters obtained by Pioneer 10 permit improvements of the first two models but also pose new questions. In the first category of models the new data indicate that the amount of hydrogen has to be increased, while in the solar models which have a heavy core (made of SiO2, MgO, Fe and Ni), the abundance of hydrogen has to be decreased, both changes pointing in the direction of incomplete miscibility present in the third category of models.

Smoluchowski, R.↗
NASA NTRS1975

Interior radiances in optically deep absorbing media. III Scattering from Haze L

The interior radiances are calculated within an optically deep absorbing medium scattering according to the Haze L phase function. The dependence on the solar zenith angle, the single scattering albedo, and the optical depth within the medium is calculated by the matrix operator method. The development of the asymptotic angular distribution of the radiance in the diffusion region is illustrated through a number of examples; it depends only on the single scattering albedo and on the phase function for single scattering. The exact values of the radiance in the diffusion region are compared with values calculated from the approximate equations proposed by Van de Hulst. The variation of the radiance near the lower boundary of an optically thick medium is illustrated with examples. The attenuation length is calculated for various single scattering albedos and compared with the corresponding values for Rayleigh scattering. The ratio of the upward to the downward flux is found to be remarkably constant within the medium.

Kattawar, G. W.↗
NASA NTRS1974

Magnetism and the interior of the moon

During the time period 1961-1972, 11 magnetometers were sent to the moon. The primary purpose of this paper is to review the results of lunar magnetometer data analysis, with emphasis on the lunar interior. Magnetic fields have been measured on the lunar surface at the Apollo 12, 14, 15, and 16 landing sites. The remanent field values at these sites are 38, 103 (maximum), 3, and 327 gammas (maximum), respectively. Simultaneous magnetic field and solar plasma pressure measurements show that the Apollo 12 and 16 remanent fields are compressed during times of high plasma dynamic pressure. Apollo 15 and 16 subsatellite magnetometers have mapped in detail the field above portions of the lunar surface and have placed an upper limit on the global permanent dipole moment. Satellite and surface measurements show strong evidence that the lunar crust is magnetized over much of the lunar globe. Magnetic fields are stronger in highland regions than in mare regions and stronger on the lunar far side than on the near side. The largest magnetic anomaly measured to date is between the craters Van de Graaff and Aitken on the lunar far side.

Dyal, P.↗
NASA NTRS1975

On the composition of the lunar interior

There is now abundant geophysical and geochemical evidence suggesting that the moon has a thick plagioclase rich outer shell. This is most easily explained by early and extensive melting of a CaO and Al2O3 rich moon followed by fractional crystallization involving plagioclase flotation. Melilite is probably an important constituent of the interior. This model explains the seismic velocities, the mean density, and the moment of inertia of the moon. The moon is 73-88% high-temperature condensate.

Anderson, D. L.↗
NASA NTRS1975

Applications of a quadratic extended interior penalty function for structural optimization

A quadratic extended interior penalty function formulation especially well suited for second-order unconstrained optimization procedures is presented. Analytical derivatives of constraints and an approximate analysis technique are used. Minimum-mass design results are presented which indicate that the combination of these procedures can help make mathematical programming a useful optimization tool for large-order structural design problems with a large number of design variables and multiple constraints. Examples include statically loaded high- and low-aspect-ratio wings simultaneously subjected to stress, displacement, minimum gage and, in some cases, maximum strain constraints.

Haftka, R. T.↗
NASA NTRS1974

Electrical conductivity of lunar surface rocks - Laboratory measurements and implications for lunar interior temperatures

Results are reported for laboratory measurements of the dc and low-frequency ac electrical conductivity of three lunar rocks with ferrous iron contents of 5 to 26 wt %. The measurements were made at temperatures ranging from 20 to 1000 C, and Mossbauer spectroscopy was used to determine the dependence of electrical conductivity on furnace atmosphere. It is found that the magnitude of electrical conductivity generally increases with increasing iron content. A comparison of the data on these samples with data on terrestrial olivines and pyroxenes shows that the electrical conductivity of anhydrous silicate minerals is influenced primarily by the concentration, oxidation state, and distribution of iron, while the silicate crystal structure is only of secondary importance. Lunar interior temperatures are deduced from experimental lunar conductivity profiles, and the resulting temperature-depth profiles are found to be consistent with those calculated for two different lunar evolutionary models as well as with various experimental constraints.

Schwerer, F. C.↗
NASA NTRS1975

The application of radar imagery to specific problems of interior Alaska

The possible applications are discussed of side-looking airborne radar imagery to specific geomorphic and environmental geologic problems in interior Alaska. The radar imagery described was acquired in July, 1972, by the NASA NP3A aircraft, as part of Mission 209 of the Earth Resources Aircraft Project. The frequency of the radar energy that was transmitted and recorded by the radar system was 16.5 Gigahertz; the wavelength of the radiant energy was about 1.8 centimeters. The radar system operated in both the real aperture and synthetic aperture modes simultaneously.

Cannon, P. J.↗
NASA NTRS1975

Department of the Interior program

The remote sensing activities of the Department of Interior are summarized. The use of satellite imagery in land and water management is described. Specific topics discussed include: land use mapping, exploration and discovery of metal, oil, and gas deposits, location of geological faults, and repetitive monitoring of dynamic environmental phenomena related to water resources.

Balsley, J. R.↗
NASA NTRS1976

Fire containment tests of aircraft interior panels

The paper describes an experimental program carried out to evaluate a possible method for testing the fire-containment qualities of aircraft interior panels. The experimental apparatus consisted of a burner that simulates various fire loads under different ventilation conditions in an enclosure of approximately the same size as an aircraft lavatory module. Two fire-containment tests are discussed in which two adjoining walls of the enclosure were made from state-of-the-art composite panels; rats were exposed to the combustion products in order to evaluate the toxic threat posed by those products. The results show that the burner can be employed to represent various fire-load conditions and that the methodology developed for fire containment can be useful in evaluating the fire resistance of composite panels before conducting large-scale tests. It is concluded that elements of the fire-containment criteria include the temperature rise on the backface of the panels as a function of time, the flame burn-through by either decomposition or severe distortion of the material, and the toxicity of the combustion gases evolved.

Kourtides, D. A.↗
NASA NTRS1976

The impact of interior cabin noise on passenger acceptance

Based on flight test data gathered in general aviation aircraft, a composite motion-noise passenger comfort model has been developed which enables the assessment of cabin interior noise impact on passenger acceptance. Relationships between special subject responses and passenger responses are given, as well as the effect of comfort on passenger acceptance. The importance of comfort and noise on the overall passenger reaction is discussed.

Rudrapatna, A. N.↗
NASA NTRS1976

Flammability characteristics of aircraft interior composites

The thermochemical and flammability characteristics of two polymeric composites currently in use and seven others being considered for use as aircraft interior panels are described. The properties studied included: (1) oxygen index of the composite constituents; (2) fire containment capability of the composite; (3) smoke evolution from the composite; (4) thermogravimetric analysis; (5) composition of the volatile products of pyrolysis. The performance of foam filled honeycomb laminated panels consisting of high-temperature laminating bismaleimide resins is compared with the performance of empty honeycomb laminated panels consisting of laminating epoxy or phenolic resins at similar densities. Processing parameters of one of the bismaleimide composites is detailed.

Kourtides, D. A.↗
NASA NTRS1976

Development of fire resistant, nontoxic aircraft interior materials

All available newly developed nonmetallic polymers were examined for possible usage in developing fire resistant, nontoxic nonmetallic parts or assemblies for aircraft interiors. Specifically, feasibility for the development of clear films for new decorative laminates, compression moldings, injection molded parts, thermoformed plastic parts, and flexible foams were given primary considerations. Preliminary data on the flame resistant characteristics of the materials were obtained. Preliminary toxicity data were generated from samples of materials submitted from the contractor. Preliminary data on the physical characteristics of various thermoplastic materials to be considered for either compression molded, injection molded, or thermoformed parts were obtained.

Haley, G.↗
NASA NTRS1977

Interior and exterior fuselage noise measured on NASA's C-8a augmentor wing jet-STOL research aircraft

Interior and exterior fuselage noise levels were measured on NASA's C-8A Augmentor Wing Jet-STOL Research Aircraft in order to provide design information for the Quiet Short-Haul Research Aircraft (QSRA), which will use a modified C-8A fuselage. The noise field was mapped by 11 microphones located internally and externally in three areas: mid-fuselage, aft fuselage, and on the flight deck. Noise levels were recorded at four power settings varying from takeoff to flight idle and were plotted in one-third octave band spectra. The overall sound pressure levels of the external noise field were compared to previous tests and found to correlate well with engine primary thrust levels. Fuselage values were 145 + or - 3 dB over the aircraft's normal STOL operating range.

Shovlin, M. D.↗