11,682 research outputs found

    Controllability of nonlinear systems

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    Hermann method for controllability determination of linear and nonlinear control system

    Effect of 1 MeV electrons on ceria-doped solar cell cover glass

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    The effect of 1 MeV electrons on the transmission properties of 1.5-percent ceria-doped solar cell cover glass was studied. Samples of doped and undoped cover glass and synthetic fused silica were irradiated with a total integrated flux of 10 to the 15th power e/sq cm. Wideband transmission and spectral transmission measurements were made before and after irradiation. The results indicate that 1.5-percent ceria-doped cover glass is much less sensitive to radiation induced discoloration than undoped cover glass. Consequently, the glass is comparable to synthetic fused silica when used as a radiation resistant solar cell cover for many space missions

    On the optimality of a totally singular vector control- an extension of the green's theorem approach to higher dimensions

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    Extension of Green theorem approach to higher dimensions for determination of optimality of totally singular vector contro

    Contact transformations and the theory of optimal control

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    Contact transformation of independent and dependent variables of Hamilton-Jacobi equatio

    Spin vector control for a spinning space station. Volume 2 - Analytic manual Final report

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    Computer manual for calculating dynamic vector control of dual spin space statio

    Ultrasonic scanning system for in-place inspection of brazed tube joints

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    A miniaturized ultrasonic scanning system for nondestructive in-place, non-immersion testing of brazed joints in stainless-steel tubing is described. The system is capable of scanning brazed tube joints, with limited clearance access, in 1/4 through 5/8 inch union, tee, elbow and cross configurations. The system has the capability to detect defective conditions now associated with material density changes in addition to those which are depended upon density variations. The system includes a miniaturized scanning head assembly that fits around a tube joint and rotates the transducer around and down the joint in a continuous spiral motion. The C-scan recorder is similar in principle to conventional models except that it was specially designed to track the continuous spiral scan of the tube joint. The scanner and recorder can be operated with most commercially available ultrasonic flaw detectors

    Ultrasonic scanning system for in-place inspection of brazed-tube joints

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    System detects defects of .051 cm in diameter and larger. System incorporates scanning head assembly including boot enclosed transducer, slip ring assembly, drive mechanism, and servotransmitter. Ultrasonic flaw detector, prototype recorder, and special recorder complete system
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