40,778 research outputs found
Types of rotor failure and characteristics of fragments
Noncontained rotor failures in U.K. engines resulting from low cycle fatigue, low cycle fatigue with superimposed high cycle fatigue, and overheating and-or overspeeding were analyzed. The size, shape, weight, velocity, energy, and direction of the fragments released from turbines and compressors were studied and are presented in graph
Quaternary and quinary modifications of eutectic superalloys strengthened by delta Ni3Cb lamellae and gamma prime Ni3Al precipitates
By means of a compositional and heat treatment optimization program based on the quaternary gamma/gamma prime-delta, a tantalum modified gamma/gamma prime-delta alloy with improved shear and creep strength combined with better cyclic oxidation resistance was identified. Quinary additions, quaternary adjustments, and heat treatment were investigated. The tantalum modified gamma/gamma prime-delta alloy possessed a slightly higher liquidus temperature and exhibited rupture strength exceeding NASA VIA by approximately three and one-half Larson-Miller parameters (C = 20) above 1000 C. Although improvements in longitudinal mechanical properties were achieved, the shear and transverse strength property goals of the program were not met and present a continuing challenge to the alloy metallurgist
Space telescope phase B definition study. Volume 2A: Science instruments, f24 field camera
The analysis and design of the F/24 field camera for the space telescope are discussed. The camera was designed for application to the radial bay of the optical telescope assembly and has an on axis field of view of 3 arc-minutes by 3 arc-minutes
Extending Gaussian hypergeometric series to the -adic setting
We define a function which extends Gaussian hypergeometric series to the
-adic setting. This new function allows results involving Gaussian
hypergeometric series to be extended to a wider class of primes. We demonstrate
this by providing various congruences between the function and truncated
classical hypergeometric series. These congruences provide a framework for
proving the supercongruence conjectures of Rodriguez-Villegas.Comment: Int. J. Number Theory, accepted for publicatio
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