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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 595 records · Page 33
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Solar power satellite offshore rectenna study

Offshore rectennas are feasible and cost competitive with land rectennas but the type of rectenna suitable for offshore use is quite different from that specified in the present reference system. A nonground plane design minimizes the weight and greatly reduces the number of costly support towers. This perferred design is an antenna array consisting of individually encapsulated dipoles with reflectors or tagis supported on feed wires. Such a 5 GW rectenna could be built at a 50 m water depth site to withstand hurricane, winter storm, and icing conditions for a one time cost of $5.7 billion. Subsequent units would be about 1.3 less expensive. More benign and more shallow water sites would result in substantially lower costs. The major advantage of an offshore rectenna is the removal of microwave radiation from populated areas.

Source record↗
NASA NTRS1980

Nasa Program Plan

Major facts are given for NASA'S planned FY-1981 through FY-1985 programs in aeronautics, space science, space and terrestrial applications, energy technology, space technology, space transportation systems, space tracking and data systems, and construction of facilities. Competition and cooperation, reimbursable launchings, schedules and milestones, supporting research and technology, mission coverage, and required funding are considered. Tables and graphs summarize new initiatives, significant events, estimates of space shuttle flights, and major missions in astrophysics, planetary exploration, life sciences, environmental and resources observation, and solar terrestrial investigations. The growth in tracking and data systems capabilities is also depicted.

Source record↗
NASA NTRS1979

A study of industrial hydrogen and syngas supply systems

The potential and incentives required for supplying hydrogen and syngas feedstocks to the U.S. chemical industry from coal gasification systems were evaluated. Future hydrogen and syngas demand for chemical manufacture was estimated by geographic area and projected economics for hydrogen and syngas manufacture was estimated with geographic area of manufacture and plant size as parameters. Natural gas, oil and coal feedstocks were considered. Problem areas presently affecting the commercial feasibility of coal gasification discussed include the impact of potential process improvements, factors involved in financing coal gasification plants, regulatory barriers affecting coal gasification, coal mining/transportation, air quality regulations, and competitive feedstock pricing barriers. The potential for making coal gasification the least costly H2 and syngas supply option. Options to stimulate coal gasification system development are discussed.

Amos, W. J.↗
NASA NTRS1979

The MPD thruster development program

Recent research results have inferred that the self-field magnetoplasmadynamic (MPD) thruster can attain efficiency and specific impulse levels which are competitive with ion thrusters. Based on these results, a program was initiated at JPL to develop this thruster for application on future spacecraft. Preliminary mission analyses have shown that the high thrust density MPD arcjet is advantageous for high power missions, such as a short trip time earth orbit transfer vehicle or a nuclear powered outer planet explorer. Direct thrust stand verification of the inferred performance levels used in these analyses is planned for a facility being assembled at Princeton University. A parallel effort at JPL is considering various thruster system configurations, energy storage concepts and propellant control techniques. In addition, a one pulse per second thruster test facility is planned at JPL to be used for thruster optimization studies including erosion and lifetime measurements.

Rudolph, L. K.↗
NASA NTRS1979

A solar thermal electric power plant for small communities

A solar power plant has been designed with a rating of 1000-kW electric and a 0.4 annual capacity factor. It was configured as a prototype for plants in the 1000 to 10,000-kWe size range for application to small communities or industrial users either grid-connected or isolated from a utility grid. A small central receiver was selected for solar energy collection after being compared with alternative distributed collectors. Further trade studies resulted in the selection of Hitec (heat transfer salt composed of 53 percent KNO3, 40 percent NaNO2, 7 percent NaNO3) as both the receiver coolant and the sensible heat thermal stroage medium and the steam Rankine cycle for power conversion. The plant is configured with road-transportable units to accommodate remote sites and minimize site assembly requirements. Results of the analyses indicate that busbar energy costs are competitive with diesel-electric plants in certain situations, e.g., off-grid, remote regions with high insolation. Sensitivity of energy costs to plant power rating and system capacity factor are given.

Holl, R. J.↗
NASA NTRS1980

A laser flash photolysis-resonance fluorescence kinetics study of the reaction Cl/2P/ + CH4 yields CH3 + HCl

The technique of laser flash photolysis-resonance fluorescence is employed to study the kinetics of the reaction Cl(2P) + CH4 yields CH3 + HCl over the temperature range 221-375 K. At temperatures less than or equal to 241 K the apparent bimolecular rate constant is found to be dependent upon the identity of the chemically inert gases in the reaction mixture. For Cl2/CH4/He reaction mixtures (total pressure = 50 torr) different bimolecular rate constants are measured at low and high methane concentrations. For Cl2/CH4/CCl/He and Cl2/CH4/Ar reaction mixtures, the bimolecular rate constant is independent of methane concentration, being approximately equal to the rate constant measured at low methane concentrations for Cl2/CH4/He mixtures. These rate constants are in good agreement with previous results obtained using the discharge flow-resonance fluorescence and competitive chlorination techniques. At 298 K the measured bimolecular rate constant is independent of the identity of the chemically inert gases in the reaction mixture and in good agreement with all previous investigations. The low-temperature results obtained in this investigation and all previous investigations can be rationalized in terms of a model which assumes that the Cl(2P 1/2) state reacts with CH4 much faster than the Cl(2P 3/2) state. Extrapolation of this model to higher temperatures, however, is not straightforward.

Ravishankara, A. R.↗
NASA NTRS1979

On the significance of the apparent absence of extraterrestrials on earth

The paper considers arguments on the existence or absence of extraterrestrial civilizations. It is suggested that arguments that even a single extraterrestrial civilization would have long ago colonized the Galaxy are not compelling. Attention is given to factors such as intraspecific competition, which could have prevented complete colonization, noting that an exception perhaps would be on time scales much greater than 10 to the 10 years. It is concluded that the fact that extraterrestrial civilizations do not appear to be represented on earth is irrelevant to the formulation of plans to search for them.

Stull, M. A.↗
NASA NTRS1979

Oxygen-enriched air for MHD power plants

Cryogenic air-separation process cycle variations and compression schemes are examined. They are designed to minimize net system power required to supply pressurized, oxygen-enriched air to the combustor of an MHD power plant with a coal input of 2000 MWt. Power requirements and capital costs for oxygen production and enriched air compression for enrichment levels from 13 to 50% are determined. The results are presented as curves from which total compression power requirements can be estimated for any desired enrichment level at any delivery pressure. It is found that oxygen enrichment and recuperative heating of MHD combustor air to 1400 F yields near-term power plant efficiencies in excess of 45%. A minimum power compression system requires 167 MW to supply 330 lb of oxygen per second and costs roughly 100 million dollars. Preliminary studies show MHD/steam power plants to be competitive with plants using high-temperature air preheaters burning gas.

Ebeling, R. W., Jr.↗
NASA NTRS1980

Echocardiographic left ventricular masses in distance runners and weight lifters

The relationships of different forms of exercise training to left ventricular mass and body mass are investigated by echocardiographic studies of weight lifters, long-distance runners, and comparatively sized untrained control subjects. Left ventricular mass determinations by the Penn convention reveal increased absolute left ventricular masses in long-distance runners and competitive weight lifters with respect to controls matched for age, body weight, and body surface area, and a significant correlation between ventricular mass and lean body mass. When normalized to lean body mass, the ventricular masses of distance runners are found to be significantly higher than those of the other groups, suggesting that dynamic training elevates left ventricular mass compared to static training and no training, while static training increases ventricular mass only to the extent that lean body mass is increased.

Longhurst, J. C.↗
NASA NTRS1979

Evaluation of finite element formulations for transient conduction forced-convection analysis

Conventional versus upwind convective finite elements, and lumped versus consistent formulations for practical conduction/forced convection analysis are evaluated on the basis of numerical studies, with finite element and finite difference lumped-parameter temperatures compared to closed-form analytical solutions for convection problems. Attention is given to two practical combined conduction and forced convection applications, stressing that the finite element method, showing superior accuracy, is competitive with the finite difference lumped-parameter method. Also considered are the computational time savings offered by the zero capacitance nodes procedure and comparative finite element and finite difference lumped-parameter computer times. The present study has reference to the design of actively cooled engine and airframe structures for hypersonic flight.

Thornton, E. A.↗
NASA NTRS1979

A summary of lighter-than-air technology development and applications in the United States

Recent studies indicate the promise of advanced LTA vehicles that can carry heavy loads and be capable of vertical takeoff and landing. Such airships may be combinations of aerostats and helicopters or modern versions of more conventional aircraft. These latter types would not be competitive with high speed modern jet air transports on established routes, but they would have a role in special situations and as long-endurance Naval and coastal surveillance aircraft. The most attractive and immediate market for modern airships in the field of short-range and heavy lift.

Mayer, N. J.↗
NASA NTRS1980

Aerodynamic design optimization of a fuel efficient high-performance, single-engine, business airplane

A design study has been conducted to optimize a single-engine airplane for a high-performance cruise mission. The mission analyzed included a cruise speed of about 300 knots, a cruise range of about 1300 nautical miles, and a six-passenger payload (5340 N (1200 lb)). The purpose of the study is to investigate the combinations of wing design, engine, and operating altitude required for the mission. The results show that these mission performance characteristics can be achieved with fuel efficiencies competitive with present-day high-performance, single- and twin-engine, business airplanes. It is noted that relaxation of the present Federal Aviation Regulation, Part 23, stall-speed requirement for single-engine airplanes facilitates the optimization of the airplane for fuel efficiency.

Holmes, B. J.↗
NASA NTRS1980

Reactor/Brayton power systems for nuclear electric spacecraft

Studies are currently underway to assess the technological feasibility of a nuclear-reactor-powered spacecraft propelled by electric thrusters. This vehicle would be capable of performing detailed exploration of the outer planets of the solar system during the remainder of this century. The purpose of this study was to provide comparative information on a closed cycle gas turbine power conversion system. The results have shown that the performance is very competitive and that a 400 kWe space power system is dimensionally compatible with a single Space Shuttle launch. Performance parameters of system mass and radiator area were determined for systems from 100 to 1000 kWe. A 400 kWe reference system received primary attention. The components of this system were defined and a conceptual layout was developed with encouraging results. The preliminary mass determination for the complete power system was very close to the desired goal of 20 kg/kWe. Use of more advanced technology (higher turbine inlet temperature) will substantially improve system performance characteristics.

Layton, J. P.↗
NASA NTRS1980

Solar power satellite offshore rectenna study

It was found that an offshore rectenna is feasible and cost competitive with land rectennas but that the type of rectenna which is suitable for offshore use is quite different from that specified in the present reference system. The result is a nonground plane design which minimizes the weight and greatly reduces the number of costly support towers. This preferred design is an antenna array consisting of individually encapsulated dipoles with reflectors supported on feed wires. Such a 5 GW rectenna could be built at a 50 m water depth site to withstand hurricane and icing conditions for a one time cost of 5.7 billion dollars. Subsequent units would be about 1/3 less expensive. The east coast site chosen for this study represents an extreme case of severe environmental conditions. More benign and more shallow water sites would result in lower costs. Secondary uses such as mariculture appear practical with only minor impact on the rectenna design. The potential advantages of an offshore rectenna, such as no land requirements, removal of microwave radiation from populated areas and minimal impact on the local geopolitics argue strongly that further investigation of the offshore rectenna should be vigorously pursued.

Source record↗
NASA NTRS1980

Market definition study of photovoltaic power for remote villages in developing countries

The potential market of photovoltaic systems in remote village applications in developing countries is assessed. It is indicated that photovoltaic technology is cost-competitive with diesel generators in many remote village applications. The major barriers to development of this market are the limited financial resources on the part of developing countries, and lack of awareness of photovoltaics as a viable option in rural electrification. A comprehensive information, education and demonstration program should be established as soon as possible to convince the potential customer countries and the various financial institutions of the viability of photovoltaics as an electricity option for developing countries.

Ragsdale, C.↗
NASA NTRS1980

Ceiling and visibility instrumentation within government agencies

The key systems requirements for ceilometer systems are described. The following items are included: range must be 10,000 ft.; laser emission must conform to the bureau of radiological health class I performance; system must detect two lowest cloud layers; display must be in either English or metric units; and system must be capable of self monitoring and testing performance. Based upon the requirements competitive prototype cloud height indicator systems are to be built.

Bonner, R. S.↗
NASA NTRS1980

Naloxone inhibits and morphine potentiates. The adrenal steroidogenic response to ACTH

The adrenal actions were stereospecific since neither the positve stereoisomer of morphine, nor that of naloxone, had any effect on the adrenal response to exogenous adrenocorticotrophic hormone (ACTH). The administration of human beta endorphin to phyophysectomized rats had no effect on the adrenal corticosterone concentration nor did it alter the response of the adrenal gland to ACTH. These results indicate that morphine can potentiate the action of ACTH on the adrenal by a direct, stereospecific, dose dependent mechanism that is prevented by naloxone pretreatment and which may involve competition for ACTH receptors on the corticosterone secreting cells of the adrenal cortex.

Heybach, J. P.↗
NASA NTRS1980

Study of component technologies for fuel cell on-site integrated energy systems

Heating, ventilation and air conditioning equipment are integrated with three types of fuel cells. System design and computer simulations are developed to utilize the thermal energy discharge of the fuel in the most cost effective manner. The fuel provides all of the electric needs and a loss of load probability analysis is used to ensure adequate power plant reliability. Equipment cost is estimated for each of the systems analyzed. A levelized annual cost reflecting owning and operating costs including the cost of money was used to select the most promising integrated system configurations. Cash flows are presented for the most promising 16 systems. Several systems for the 96 unit apartment complex (a retail store was also studied) were cost competitive with both gas and electric based conventional systems. Thermal storage is shown to be beneficial and the optimum absorption chiller sizing (waste heat recovery) in connection with electric chillers are developed. Battery storage was analyzed since the system is not electric grid connected. Advanced absorption chillers were analyzed as well. Recommendations covering financing, technical development, and policy issues are given to accelerate the commercialization of the fuel cell for on-site power generation in buildings.

Lee, W. D.↗