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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 775 records · Page 43
All sourcesNASA NTRSDOE OSTI
NASA NTRS1965

Injector-valve device Patent

Apparatus for cooling and injecting hypergolic propellants into combustion chamber of small rocket engine

Stein, S.↗
NASA NTRS1972

Hermetic isolation valves

Mechanism consists of thermal actuator, which expands when flow is desired, forcing cutter poppet through a diaphragm seal. Design concept is useful in systems that are stored for long periods of time before operation.

Makowski, M. J.↗
NASA NTRS1971

Effect of varying ventricular function by extrasystolic potentiation on closure of the mitral valve.

Mitral regurgitant indexes were measured by roentgen videodensitometry in anesthetized dogs without thoracotomy before, during and after extrasystolic potentiation of ventricular contraction while the atria and ventricles were driven in normal temporal sequence simultaneously or in such a way as to induce atrial fibrillation. Small amounts of mitral reflux were observed with simultaneous atrial and ventricular driving and with atrial fibrillation in the control measurements before initiation of extrasystolic potentiation. Reflux became negligible during extrasystolic potentiation and increased beyond control levels after termination of extrasystolic potentiation.

Vandenberg, R. A.↗
NASA NTRS1975

A new real-time non-coherent to coherent light image converter - The hybrid field effect liquid crystal light valve

A new, high-performance device has been developed for application to real-time coherent optical data processing. The new device embodies a CdS photoconductor, a CdTe light-absorbing layer, a dielectric mirror, and a liquid crystal layer sandwiched between indium-tin-oxide transparent electrodes deposited on optical quality glass flats. The noncoherent image is directed onto the photoconductor; this reduces the impedance of the photoconductor, thereby switching the ac voltage that is impressed across the electrodes onto the liquid crystal to activate the device. The liquid crystal is operated in a hybrid field effect mode. It utilizes the twisted nematic effect to create a dark off-state and the optical birefringence effect to create the bright on-state. The liquid crystal modulates the polarization of the coherent read-out light so an analyzer must be used to create an intensity modulated output beam.

Grinberg, J.↗
NASA NTRS1978

Self-alining valve poppet and seat

Poppet-and-seat combination is useful in fluid-control system that has to operate at high temperatures with low leak rates. Contaminants in flow stream are removed before they reach sealing surfaces by altering direction of flow several times before it enters poppet-and-seat flow passage. Particles are separated and deposited on surfaces not affecting sealing performance.

Olivas, U. P.↗
NASA NTRS1979

Latching solenoid for cryogenic valves

Pull-in and Delatching Coils of cryogenic solenoid contain copper and low-resistance, low-temperature-coefficient alloy to limit current at low temperatures.

Wang, W. S.↗
NASA NTRS1979

Bond graph for modeling valves and switches

Digital graph element represents two-state devices. It can be used in modeling mechanical stops, backlash, and other discontinuities that occur whenever subsystems are connected or disconnected.

Gebben, V. D.↗