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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 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Fire-resistant aircraft materials development and evaluation program

The overall objectives of this program are to provide a more fire-resistant commercial aircraft interior and to improve the fuselage insulation barrier between the cabin interior and an exterior fuel fire. Significant secondary objectives are to reduce the smoke and toxic gas production of the materials and to meet the end item use requirements pertaining to wearability, color fastness, and aesthetic appeal. It is shown that the fuselage insulation materials must meet stringent requirements pertaining to acoustic attenuation, low density, and water repellency.

Bricker, R. W.↗
NASA NTRS1975

Evaluation program for secondary spacecraft cells

The cycle life tests to determine the performance capabilities of packs of cells under different loads and temperature conditions are reported. Results are summarized, and the failure of 14 failed cells is analyzed. It was found that the main cause of failure was separator deterioration and migration of the negative plate material.

Harkness, J. D.↗
NASA NTRS1975

Earth orbital teleoperator manipulator system evaluation program

The performance of an orbital teleoperator system which includes small dextrous servicing manipulators to be used in satellite servicing was examined. System/operator performance testing was implemented and the results of a fine positioning control test using two different manipulator systems varying widely in manipulator configuration and control systems are presented. Fine position control is viewed as representing a fundamental requirement placed on manipulator control. The relationship of position control to more complex tasks which directly represent on-orbit servicing operations are also presented.

Kirkpatrick, M., III↗
NASA NTRS1975

Lean mixture engine testing and evaluation program

Experimental results for fuel consumption and emissions are presented for a 350 CID (5.7 liter) Chevrolet V-8 engine modified for lean operation with gasoline. The lean burn engine achieved peak thermal efficiency at an equivalence ratio of 0.75 and a spark advance of 60 deg BTDC. At this condition the lean burn engine demonstrated a 10% reduction in brake specific fuel consumption compared with the stock engine; however, NOx and hydrocarbon emissions were higher. With the use of spark retard and/or slightly lower equivalence ratios, the NOx emissions performance of the stock engine was matched while showing a 6% reduction in brake specific fuel consumption. Hydrocarbon emissions exceeded the stock values in all cases. Diagnostic data indicate that lean performance in the engine configuration tested is limited by ignition delay, cycle-to-cycle pressure variations, and cylinder-to-cylinder distribution.

Dowdy, M. W.↗
NASA NTRS1974

Early detection of disease program: Evaluation of the cellular immune response

The early cellular responses of specific components of the leukocyte and epithelial cell populations to foreign challenges of both an infectious and noninfectious character were evaluated. Procedures for screening potential flight crews were developed, documented, and tested on a control population. Methods for preparing suitable populations of lymphocytes, polymorphonuclear leukocytes, macrophages, and epithelial cells were first established and evaluated. Epithelial cells from viral infected individuals were screened with a number of anti-viral antisera. This procedure showed the earliest indication of disease as well as providing a specific diagnosis to the physicians. Both macrophages and polymorphonuclear leukocytes were studied from normal individuals, smokers, and patients with viral infections. Newer techniques enabling better definition of lymphocyte subpopulations were then developed, namely the E and EAC rosette procedures for recognition of T (thymus-derived) and B (bone-marrow-derived) lymphocyte subpopulations. Lymphocyte and lymphocyte subpopulation response to multiple mitogens have been evaluated.

Criswell, B. S.↗
NASA NTRS1975

Early detection of disease program: Evaluation of the cellular immune response

Surfaces of normal, cultured, and mitogen-stimulated mouse lymphoid cells were examined by scanning electron microscopy (SEM). Lymphocytes with smooth, highly villous and intermediate surfaces were observed in cell suspensions from both spleens and thymuses of normal mice and from spleens of congenitally athymic (nude) mice. Several strain-specific surface features were noted, including the spine-like appearance of microvilli on C57B1/6 lymphocytes. Although thymus cell suspensions contained somewhat more smooth cells than did spleen cell preparations, lymphocyte derivation could not be inferred from SEM examination. Studies of cells stimulated with mitogenic agents for thymus-derived lymphocytes (concanavalin A) or for bone marrow-derived lymphocytes (lipopolysaccharide) suggested that, in the mouse, development of a complex villous surface is a general concomitant of lymphocyte activation and transformation.

Criswell, B. S.↗
NASA NTRS1977

Earth orbital teleoperator manipulator system evaluation program

The operator's ability to perform five manipulator tip movements while using monoptic and stereoptic video systems was assessed. Test data obtained were compared with previous results to determine the impact of camera placement and stereoptic viewing on manipulator system performance. The tests were performed using the NASA MSFC extendible stiff arm Manipulator and an analog joystick controller. Two basic manipulator tasks were utilized. The minimum position change test required the operator to move the manipulator arm to touch a target contract. The dexterity test required removal and replacement of pegs.

Brye, R. G.↗
NASA NTRS1977

F100 multivariable control synthesis program: Evaluation of a multivariable control using a real-time engine simulation

The design, evaluation, and testing of a practical, multivariable, linear quadratic regulator control for the F100 turbofan engine were accomplished. NASA evaluation of the multivariable control logic and implementation are covered. The evaluation utilized a real time, hybrid computer simulation of the engine. Results of the evaluation are presented, and recommendations concerning future engine testing of the control are made. Results indicated that the engine testing of the control should be conducted as planned.

Szuch, J. R.↗
NASA NTRS1977

Tetroon evaluation program

The actual volume of a constant volume superpressured tetrahedron shaped balloon changes as the amount of superpressure is changed. The experimental methods used to measure these changes in volume are described and results are presented. The basic equations used to determine the amount of inflation gas required for a tetroon to float at a predetermined flight level are presented and inflation techniques discussed.

Beemer, J. D.↗
NASA NTRS1977

The Goddard Space Flight Center high efficiency cell development and evaluation program

Laboratory tests and flight experiments showed that solar cells can be produced in quantity, that they are suitable for space flight applications, and that the power produced ranged from 20 to 35% more than that of conventional cells. In a benign flight environment, the cells degraded at approximately the same rate as conventional cells. In synchronous orbit, the rate exceeded that of conventional cells, but high efficiency cells still showed significant power advantage after two years. Irradiation test results showed the voltage-temperature coefficients to be comparable to conventional cells. However, current-temperature coefficients were not only higher initially, but also increased significantly with irradiation. Although thin cells with good performance characteristics were made, significant problem areas pertinent to production were disclosed, particularly for cells with thickness of 0.100 mm or less. The overall program led to the use of advanced high efficiency cells on the International Sun-Earth Explorer solar panels.

Slifer, L. W.↗
NASA NTRS1978

Evaluation program for secondary spacecraft cells

The results of life cycle tests of secondary spacecraft cells are summarized. Cells consisted of seven sample classifications ranging from 3.0 to 20 ampere-hours, 1326 nlc nickel cadmium, 183 silver cadmium, and 125 silver zinc sealed cells. Variables examined include load, charge control, and temperature conditions.

Harkness, J. D.↗