Structures in granitic bathyliths and associated foldbelts in relation to mineral resources

There are no author-identified significant results in this report

An experimental investigation of the effect of boundary layer refraction on the noise from a high-speed propeller

Models of supersonic propellers were previously tested for acoustics in the Lewis 8- by 6-Foot Wind Tunnel using pressure transducers mounted in the tunnel ceiling. The boundary layer on the tunnel ceiling is believed to refract some of the propeller noise away from the measurement transducers. Measurements were made on a plate installed in the wind tunnel which had a thinner boundary layer than the ceiling boundary layer. The plate was installed in two locations for comparison with tunnel ceiling noise data and with fuselage data taken on the NASA Dryden Jetstar airplane. Analysis of the data indicates that the refraction increases with: increasing boundary layer thickness; increasing free stream Mach number; increasing frequency; and decreasing sound radiation angle (toward the inlet axis). At aft radiation angles greater than about 100 deg there was little or no refraction. Comparisons with the airplane data indicated that not only is the boundary layer thickness important but also the shape of the velocity profile. Comparisons with an existing two-dimensional theory, using an idealized shear layer to approximate the boundary layer, showed that the theory and data had the same trends. Analysis of the data taken in the tunnel at two different distances from the propeller indicates a decay with distance in the wind tunnel at high Mach numbers but the decay at low Mach numbers is not as clear

Polyimide polymers provide improved ablative materials

Principle heat absorption of silica-reinforced plastic ablative materials occurs from the in-depth reaction of silica with carbon to form silicon monoxide and carbon monoxide. The higher the degree of completion of this reaction, the higher the capacity of the ablative material to absorb heat

Polyimide polymers provide higher char yield for graphitic structures

Technique for manufacture of graphite composites uses high-char-forming processable polyimide resin systems to produce the graphitic matrix. Only three cyclic steps are required to yield a 99.7 percent graphite product

Investigation of resin systems for improved ablative materials

Resin systems for matrix material in ablative composite for liquid rocket combustion chambers using fluorine-containing propellant

Public attitudes toward people with intellectual disabilities after viewing Olympic or Paralympic performance

Despite some changes to the way that people with intellectual disabilities (ID) are viewed in society, negative attitudes prevail. One of the aspirations of the 2012 Paralympic games was to influence the public’s attitudes toward people with disabilities. The aim of this study was to investigate whether stimuli depicting people with ID performing at Paralympic level of competition change attitudes toward ID. A mixed randomized comparison design was employed comparing 2 groups: those who viewed Paralympic-level ID sport footage and information and those who viewed Olympic footage and information. One hundred fourteen students, mean age 25 yr, were administered measures of implicit (subconscious) attitudes toward disability and explicit (belief-based) attitudes toward ID. Implicit attitudes significantly changed in a positive direction for both groups. The findings provide evidence that both Paralympic (ID) and Olympic media coverage may have at least a short-term effect on attitudes toward people with disabilities

Investigation of resin systems for improved ablative materials Interim report, 10 Jan. - 1 Jul. 1966

Preparation, and evaluation of polyimide sulfone resins, graphite-silica reinforced polyamide resins, and resin resistance to FLOX- methane, and fluorine-hydrogen fuel

An experimental feasibility study for the preparation of thermo-oxidatively stable Pyrrone laminates

Synthesis of Pyrrone laminates from sulfone dianhydrid

Reinforced structural plastics

Reinforced polyimide structures are described. Reinforcing materials are impregnated with a suspension of polyimide prepolymer and bonded together by heat and pressure to form a cured, hard-reinforced, polyimide structure