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Lost City /Oklahoma/ meteorite mineralogical and chemical investigations, comparing with Pribram and Ucera meteorites
Time-temperature cycle provides sufficient lithium in the active regions of solar cells. Gradient of lithium is less subject to alteration by P-N junction field.
The effort reported here represents data of lithium properties in bulk-silicon samples before and after irradiation for analytical information required to characterize the interactions of lithium with radiation-induced defects in silicon. A model of the damage and recovery mechanisms in irradiated-lithium-containing solar cells is developed based on making measurements of the Hall coefficient and resistivity of samples irradiated by 1-MeV electrons. Experiments on bulk samples included Hall coefficient and resistivity measurements taken as a function of: (1) bombardment temperature, (2) resistivity, (3) fluence, (4) oxygen concentration, and (5) annealing time at temperatures from 300 to 373 K.
The correlation between the equatorial velocities of the components of double stars is studied from a statistical standpoint. A theory of rotational correlation is developed and discussed with regard to its applicability to existing observations. The theory is then applied to a sample of visual binaries which are the least studied for rotational coupling. Consideration of eclipsing systems and spectroscopic binaries is limited to show how the degrees of freedom in the spin parallelism problem can be reduced. The analysis lends support to the existence of synchronism in closely spaced binaries.
Coning motion can prevent photographic and TV cameras and other oriented spacecraft experiments from maintaining a steady scan, and it can introduce a ripple in the high-gain communication system. Nutation dampers are used to remove this type of spacecraft instability. The first nutation damper flown in a missile for the stabilization of the gyroscope consisted of a hollow ring that was partially filled with mercury, and the sloshing of the mercury dissipated the nutational energy. A similar mercury-ring damper was used in the Pioneer 1 lunar probe in 1958 and became the first nutation damper to be used in space. Since then many types of nutation dampers have been designed for spin-stabilized spacecraft ranging in size from small scientific satellites to large space stations.
Various processes for fireproofing materials are discussed. The conditions under which fireproofing measures may be adequate are compared with conditions under which the measures may be inadequate. The mechanisms for flame propagation and conditions required for ignition and burning are described.
An experimental investigation of the temperature and velocity fields generated by a two-dimensional transverse jet was conducted. An approximate analysis of a deflected radial plane jet was developed. An analytical model of aircraft ingestion was extended to include computation of the inlet flow field. An investigation of the use of flaps as thrust reversers was initiated. Analyses of the impingement of a round incompressible and a round compressible jet on a arbitrary axisymmetric surface were completed. A computer study of the effects on performance of thrust reverser geometry was completed and the results compared with existing data. An experimental investigation of three-dimensional jet impingement on nonplane surfaces was also initiated.
The rationale and objectives for landing an Apollo mission near a Surveyor spacecraft on the moon are discussed. Surveyor 3 and the planning of the Apollo 12 flight are considered. Mission operations and returned material, including material handling, are reviewed. The analysis of the returned parts, soil, and photographs is considered.
An analysis of the principles of strapdown inertial platforms is presented, and the advantages of the strapdown system as compared to other stabilized systems are discussed. The application of the rebalance loop to continuously restore the position of sensor output axes is described. The attitude logarithms and the rebalance electronics which are required for accurate navigation are examined.
The summary of the interfacing activity analyses for the orbital operations study is presented. The significant analyses are grouped into categories as follows: (1) structural and mechanical activity, (2) data management, and (3) support operations. Specific subjects concerning payload deployment, communications, rendezvous, and stationkeeping are discussed.
Consideration of the possibility of studying diffuse celestial sources of relatively low surface brightness such as the Milky Way, zodiacal light, and gegenschein from above the earth's atmosphere with equipment flown in artificial satellites. The techniques used for this purpose are reviewed, and some of the difficulties encountered in daytime observations from satellites by the use of a special photometer and polarimeter flown in the orbiting skylab observatory, OSO-6, are cited.
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This report surveys the field of diagnosis and introduces some of the key algorithms and heuristics currently in use. Fault diagnosis is an important and a rapidly growing discipline. This is important in the design of self-repairable computers because the present diagnosis resolution of its fault-tolerant computer is limited to a functional unit or processor. Better resolution is necessary before failed units can become partially reuseable. The approach that holds the greatest promise is that of resident microdiagnostics; however, that presupposes a microprogrammable architecture for the computer being self-diagnosed. The presentation is tutorial and contains examples. An extensive bibliography of some 220 entries is included.
The inverse scattering problem is introduced in the context of the Schroedinger equation. The emphasis is on the Gelfand Levitan approach to the nonrelativistic problem at fixed angular momentum.
The progressive realization of the consequences of nonuniqueness imply an evolution of both the methods and the centers of interest in inverse problems. This evolution is schematically described together with the various mathematical methods used. A comparative description is given of inverse methods in scientific research, with examples taken from mathematics, quantum and classical physics, seismology, transport theory, radiative transfer, electromagnetic scattering, electrocardiology, etc. It is hoped that this paper will pave the way for an interdisciplinary study of inverse problems.
NASA's current plans and priorities through the mid-1980s are briefly presented including the fly-thru mission to Comet d'Arrest in 1976, Grand-Tour missions to the outer planets, and the Venus Explorer program.
Progress reported on principle NASA programs for the reduction of aircraft engine noise emphasizes the Quiet Engine Program. Considered are fan noise and performance, fan noise suppression, and jet noise reduction for a broad spectrum of airplanes including new subsonic airplanes, the older subsonic airplanes in service today, STOL airplanes of the future, and future supersonic transports. Noise reductions achieved in the framework of the Quiet Engine Program are demonstrated and future possible applications of low noise technology to airplanes are discussed.