7,288 research outputs found
Rf transparent, energy absorbing structural elements monthly progress report no. 9, feb. 1 - mar. 31, 1964
Radio frequency energy absorbing structural elements and material
RF transparent, energy absorbing, structural elements, phase II Final report, 5 Jun. 1963 - 16 Mar. 1964
Energy absorbing, structural elements having high specific energy absorption and low dielectric constant and loss tangent - space vehicle applicatio
Development of a low temperature battery for space probe applications Final report, 24 Jun. 1964 - 23 Jun. 1965
Low temperature ammonia batteries for space probe application
Feasibility model of a high reliability five-year tape transport, volume 2
Analysis of the design features of the modularized tape transport renders a life expectancy in excess of five years. Tests performed on the tape transport were directed toward determining its performance capability. These tests revealed that the tape jitter and skew are in the range achieved by high quality digital tape transports. Guidance of the tape in the lateral sense by the use of the two hybrid crowned rollers proved to be excellent. Tracking was maintained within less than one thousandth inch (approximately 2 micrometers). The guidance capability demonstrated makes possible the achievement of the performance objective of 7.2 x 10 to the 9th power storage capability employing 1500 ft. of one inch wide tape with a packing density of 5,000 bits per inch per track on 80 tracks. Also, the machine showed excellent characteristics operating over a wide range of tape speeds. The basic design concept lends itself to growth and adaptation to a wide range of recorder requirements
Feasibility model of a high reliability five-year tape transport, Volume 1
The development, performance, and test results for the spaceborne magnetic tape transport are discussed. An analytical model of the tape transport was used to optimize its conceptual design. Each of the subsystems was subjected to reliability analyses which included structural integrity, maintenance of system performance within acceptable bounds, and avoidance of fatigue failure. These subsystems were also compared with each other in order to evaluate reliability characteristics. The transport uses no mechanical couplings. Four drive motors, one for each reel and one for each of two capstans, are used in a differential mode. There are two hybrid, spherical, cone tapered-crown rollers for tape guidance. Storage of the magnetic tape is provided by a reel assembly which includes the reel, a reel support structure and bearings, dust seals, and a dc drive motor. A summary of transport test results on tape guidance, flutter, and skew is provided
Epitaxial strain modulated electronic properties of interface controlled nickelate superlattice
Perovskite nickelate heterostructure consisting of single unit cell of
EuNiO and LaNiO have been grown on a set of single crystalline
substrates by pulsed laser interval deposition to investigate the effect of
epitaxial strain on electronic and magnetic properties at the extreme interface
limit. Despite the variation of substrate in-plane lattice constants and
lattice symmetry, the structural response to heterostructuring is primarily
controlled by the presence of EuNiO layer. In sharp contrast to bulk
LaNiO or EuNiO, the superlattices grown under tensile strains exhibit
metal to insulator transition (MIT) below room temperature. The onset of
magnetic and electronic transitions associated with the MIT can be further
separated by application of large tensile strain. Furthermore, these
transitions can be entirely suppressed by very small compressive strain. X-ray
resonant absorption spectroscopy measurements reveal that such
strain-controlled MIT is directly linked to strain induced self-doping effect
without any chemical doping.Comment: Accepted in Phys. Rev.
Epitaxial growth of (111)-oriented LaAlO/LaNiO ultra-thin superlattices
The epitaxial stabilization of a single layer or superlattice structures
composed of complex oxide materials on polar (111) surfaces is severely
burdened by reconstructions at the interface, that commonly arise to neutralize
the polarity. We report on the synthesis of high quality LaNiO/mLaAlO
pseudo cubic (111) superlattices on polar (111)-oriented LaAlO, the
proposed complex oxide candidate for a topological insulating behavior.
Comprehensive X-Ray diffraction measurements, RHEED, and element specific
resonant X-ray absorption spectroscopy affirm their high structural and
chemical quality. The study offers an opportunity to fabricate interesting
interface and topology controlled (111) oriented superlattices based on
ortho-nickelates
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