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Results for “palm”

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 199 records · Page 11
All sourcesNASA NTRSDOE OSTI
NASA NTRS1965

The blue haze of mars.

Martian blue haze properties correlated with interplanetary dust, meteor showers and solar flares

METEOR SHOWER↗
NASA NTRS1964

The Blue Haze of Mars

Blue clearings of Mars atmosphere as function of number of meteor showers intersecting Mars orbit at intervals of heliocentric longitude

MARS ATMOSPHERE↗
NASA NTRS1967

Enhanced luminance of the moon.

Lunar surface luminance transient enhancement noting photoabsorbing color center formation, increased reflectivity and photoluminescence, photoionization and photoemission

LUNAR LUMINESCENCE↗
NASA NTRS1968

Planetary atmospheres

Planetary atmospheres data in 1967 for Venus, Mercury, Mars, Jupiter, Earth, and Moon

Colegrove, F. D.↗
NASA NTRS1975

Improved toughness of silicon carbide

Several techniques were employed to apply or otherwise form porous layers of various materials on the surface of hot-pressed silicon carbide ceramic. From mechanical properties measurements and studies, it was concluded that although porous layers could be applied to the silicon carbide ceramic, sufficient damage was done to the silicon carbide surface by the processing required so as to drastically reduce its mechanical strength. It was further concluded that there was little promise of success in forming an effective energy absorbing layer on the surface of already densified silicon carbide ceramic that would have the mechanical strength of the untreated or unsurfaced material. Using a process for the pressureless sintering of silicon carbide powders it was discovered that porous layers of silicon carbide could be formed on a dense, strong silicon carbide substrate in a single consolidation process.

Palm, J. A.↗
NASA NTRS1976

Improved toughness of silicon carbide

Impact energy absorbing layers (EALs) comprised of partially densified silicon carbide were formed in situ on fully sinterable silicon carbide substrates. After final sintering, duplex silicon carbide structures resulted which were comprised of a fully sintered, high density silicon carbide substrate or core, overlayed with an EAL of partially sintered silicon carbide integrally bonded to its core member. Thermal cycling tests proved such structures to be moderately resistant to oxidation and highly resistant to thermal shock stresses. The strength of the developed structures in some cases exceeded but essentially it remained the same as the fully sintered silicon carbide without the EAL. Ballistic impact tests indicated that substantial improvements in the toughness of sintered silicon carbide were achieved by the use of the partially densified silicon carbide EALs.

Palm, J. A.↗