URCA shells in dense stellar interiors
Stellar thermal and vibrational energy losses due to URCA shells in interiors
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.
Stellar thermal and vibrational energy losses due to URCA shells in interiors
Laminar heating in hypersonic vehicles interior corners, analyzing helium tunnel heat transfer data for various intersecting wedge corners
Lunar sea, mascon and interior composition, discussing crystallization of Apollo 11 Tranquillity samples and synthetic analogs at high pressure
Eclipsing binary stars minima variations related to orbit perturbations and rotational angular momentum of component interiors
Specialized tool enables visual inspection of interior bore surfaces of pipe lines having sharp bends and blind runs. Adjustable, hinged optical head permits viewing of bore surfaces at angles from 0 deg to 115 deg to the principal axis of the sight tube.
Thermal models investigated for upper limits on lunar radioactivity consistent with temperature distribution based on electrical conductivity of lunar interior
Lunar interior electrical conductivity and temperature from various conductivity models, considering interplanetary magnetic source field
Lunar interior thermal history models for setting radioactive heat sources upper limits consistent with proposed temperature distribution
Lunar interior electrical conductivity and temperature three-layer model from magnetic transient response measurement in solar wind
Dielectric properties of Apollo 12 samples and lunar interior as function of frequency and temperature
Evidence is summarized to show that the configuration of e lines which governs the appearance of H-alpha fine structure in active regions is set mainly by motions in the subphotosphere where these lines are anchored. It is shown that H-alpha fine structure is directly coupled to a layer probably more than 5000 km below the photosphere, and little distortion of the strong fields is expected in the ines. The shorter rotation period of active regions observed by Howard and others (compared to the photospheric gas) reted as a result ofthis direct coupling of the strong field to a more rapidly rotating solar interior. The effects of dragging such a field through a photosphere of finite resistivity are briefly considered for features of various observed cross-sections.
The exact solutions are obtained for a one dimensional model of a scattering and absorbing medium. The results are given for both the reflected and transmitted radiance for any arbitrary surface albedo as well as for the interior radiance. These same quantities are calculated by the matrix operator method. The relative error of the solutions is obtained by comparison with the exact solutions as well as by an error analysis of the equations. The importance of an accurate starting value for the reflection and transmission operators is shown. A fourth order Runge-Kutta method can be used to solve the differential equations satisfied by these operators in order to obtain such accurate starting values.
The activities of the U.S. Department of Interior which have benefited from ERTS-1 data are described. It is stated that the primary interest is in the area of land use. Legislative actions regarding land use are reported. Programs involving renewable resources are stressed.
Phase equilibrium experiments at both high and low pressures on lunar samples and synthetic compositions are reported as well as related petrographic studies of lunar rock samples. The objectives were to trace the origins of rocks found on the lunar surface, to characterize the nature of the lunar interior and to locate and identify the sources of lunar magmas.
For materials thought to be important in the lunar interior, compressional velocities are estimated and compared with lunar seismic data. The results obtained support the conclusion that the moon is an extremely well differentiated body. This is consistent with thermal history calculations which suggest that the moon was close to or in excess of melting (solidus) temperatures throughout most of its volume early in its history.
Direct shear-wave arrivals from seismic events originating on the far side of the moon are not observed at some of the stations of the Apollo seismic network. These data suggest that the material in the lunar interior at a depth of 1000 to 1100 kilometers is more dissipative for seismic shear waves than the lithosphere above, and possibly exists in a partially molten state akin to the earth's asthenosphere.
The compressional velocities are estimated for materials thought to be important in the lunar interior and compared with lunar seismic results. The lower lunar crust has velocities appropriate for basalts or anorthosites. Anorthosite is preferred if lunar basalts result from a small degree of partial melting. The high velocities associated with the uppermost mantle imply high densities and a change to a lighter assemblage at depths of the order of 120 km. Ca- and Al-rich minerals are important components of both the lower crust and the upper mantle. Most of the moon may have accreted from refractory material rich in Ca, Al, U, and the rare-earth elements. The important mineral of the upper mantle is garnet; possible accessory minerals are kyanite, spinel and rutile. If the seismic results stand up, the high-velocity layer in the moon is more likely to be a high-pressure form of anorthosite than eclogite, pyroxenite, or dunite.
Important confirmations that the Earth's inner core is solid have recently come from analyses of records of free Earth oscillations and from the apparent detection of the seismic phase PKJKP. Corresponding support is given to the theory which supplied the primary evidence for rigidity in the inner core. This theory requires the incompressibility and its gradient with respect to the pressure p to vary fairly smoothly with p inside planets, and supplies a potent restriction on the allowable variations of particular physical properties inside parts of planetary interiors. The theory is at present principally applicable to the Earth and Venus. The paper reviews some of the principal implications.