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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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Tensile specimens can be tested in liquid nitrogen without subjecting the cryostat to tilting during assembly of the specimen in the liquid nitrogen-filled cryostat. A universal joint with a semielliptical head and socket reduces misalignment and permits only limited side travel.
Lunar dust degradation effects and dust removal/prevention concept
Inflatable tourniquet effects on cardiovascular deconditioning during bed rest and water immersion studies on humans
Polyurethane foam encapsulation techniques for maintaining constant atmosphere and providing mechanical protection against high voltage breakdown in spacecraft ion propulsion systems
Physiological alterations in blood pressure, heart functioning, and metabolism following bed rest and tilt tolerance tests
Tables summarizing blood chemistries, hemodynamic responses, fluid and mineral balances, urine components, and other data obtained on males subjected to bed rest and tilt tolerance tests
Performance and reliability testing of 10 n-p-n silicon transistors from critical spacecraft locations
Halon 1301 /bromotrifluoromethane/ concentration for inerting Aerozine-50 spills or extinguishing fires, noting joint use of carbon dioxide and water
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Iron cyanide additive for surface stabilization of ZnO irradiated with UV in vacuum
Proposed concept, based on law of mass action uses addition of salt to increase chlorine ions produced in sodium hydrochlorite solutions, thereby increasing solution shelf-life. This technique is not costly. Usefulness will be determined by acceptability of salt in product undergoing long shelf-life.
Maintenance program which is concise and inexpensive to operate adapts to almost any system that has a FORTRAN compiler. Program operates on a stored data base with an output consisting of scheduling information and various management reports.
One shot multivibrator circuit for producing long duration output pulses
Method which uses a disposable metal gasket that is removed when system is deactivated eliminates oil migration from mechanical pump to other areas of the system.
Procedures for installing fire protection systems in large buildings are discussed. Factors considered in the safety management are: (1) distribution of water supply, (2) design and location of exits, (3) emergency power system, and (4) maintenance procedures.
Recommendations for improving the methodology of pogo suppression for the space shuttle include: Consideration of inter-pump location for accumulator or active device, inclusion of tank outflow effects in dynamic structural analysis, the use of simplified transfer functions in systems studies, three phase dynamic testing program for turbopump with development of dynamic flowmeters, and the use of a linearized mathematical model for engine physics studies.
A method is proposed for dealing with the divergence phenomenon problem encountered in applications of minimum-variance recursive estimators when the error covariance calculated by the estimator becomes inconsistent with the actual error covariance. The proposed method differs from previous ones in that the state model and statistics are accepted as given. The form of the optimal estimator is used, but a constant check is made on the consistency of the calculated and actual error covariances. The method is independent of the source of error, whether it be inaccuracies in the system model, incorrect values of the a priori and random process statistics, approximations required in the case of nonlinear systems, or computational roundoff. Several simulated examples, in which inconsistencies in the calculated and actual error covariances exist, show a significant improvement in the performance of the estimator when the given procedure is applied.
The current reliability problems related to electronic components and microcircuits are presented in this paper. Specific process controls, design, materials, application constraints, destructive testing, electrical tests, and procedures for implementation are recommended to improve the reliability of selected electronic components.