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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 847 records · Page 47
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Coal supply for California

The potential sources and qualities of coals available for major utility and industrial consumers in California are examined and analyzed with respect to those factors that would affect the reliability of supplies. Other considerations, such as the requirements and assurances needed by the coal producers to enter into long-term contracts and dedicate large reserves of coal to these contracts are also discussed. Present and potential future mining contraints on coal mine operators are identified and analyzed with respect to their effect on availability of supply.

Yancik, J. J.↗
NASA NTRS1978

Is photon angular momentum important in molecular collision processes occurring in a laser field

The importance of the rigorous treatment of photon angular momentum in molecular-collision processes occurring in the presence of intense radiation is investigated. An alternate approximate treatment, which essentially neglects the angular momentum coupling between the photon and the molecular degrees of freedom by averaging over the angular dependence of the interaction matrix elements, is presented and applied to a model calculation. The degeneracy-averaged results of this calculation compare remarkably well with the results of a rigorous calculation, from which we conclude (with reservation) that the explicit consideration of photoangular momentum coupling in molecular-collision problems is unnecessary.

Devries, P. L.↗
NASA NTRS1979

The Get Away Special Program

The paper deals with the Get Away Special (GAS) Program which was initiated on the realization that not every Space Shuttle mission would make full use of the volume and weight capability of the Shuttle system. Currently, the GAS Program incorporates 158 domestic and foreign users who have reserved 270 spaces. Not all users and not all experiments are expected to meet the objective of processing to prime experiments for Shuttle. Each experiment will be worthy in its own right and each user will benefit to the limit of his ability and involvement. The structure and the mounting system of the GAS container are described, along with its pressure, thermal, and electronic characteristics. Safety philosophy and requirements are noted, and possible options to the standard contained are discussed.

Ott, E. J.↗
NASA NTRS1979

The Einstein /HEAO 2/ X-ray Observatory

The Einstein (HEAO 2) X-ray Observatory, launched in 1978, includes a fully imaging focusing X-ray telescope with an angular resolution of a few arc sec, a field of view of up to one deg, and a sensitivity several hundred times greater than previously available in any X-ray astronomy experiment. A high-resolution imager, an imaging proportional counter, a focal plane crystal spectrometer, and a monitor proportional counter are among the principal instruments on board the Einstein X-ray Observatory. About 20% of the total effective observing time in the first year of the X-ray astronomy experiment has been reserved for guest observers.

Giacconi, R.↗
NASA NTRS1980

Energy-saving thermostat

Thermostat for two-stage heating system adjusts turn-on time and thermostat setpoint so that reserve resistance electrical heaters are not activated in morning warm up. Thermostat monitors outside temperature and turns on heat earlier in cold weather so that room will be at desired temperature by specified time. Mechanical, electrical, electronic, pneumatic, or microprocessor versions of device are possible. Correctional factors can be included where second-stage operation is more cost-effective than prolonged first-stage operation.

Jensen, R. N.↗
NASA NTRS1981

Common data buffer

Time-shared interface speeds data processing in distributed computer network. Two-level high-speed scanning approach routes information to buffer, portion of which is reserved for series of "first-in, first-out" memory stacks. Buffer address structure and memory are protected from noise or failed components by error correcting code. System is applicable to any computer or processing language.

Byrne, F.↗
NASA NTRS1980

Catecholamines and myocardial contractile function during hypodynamia and with an altered thyroid hormone balance

The dynamics of catecholamine content and myocardial contractile function during hypodynamia were studied in 109 white rats whose motor activity was severely restricted for up to 30 days. During the first five days myocardial catecholamine content, contractile function, and physical load tolerance decreased. Small doses of thyroidin counteracted this tendency. After 15 days, noradrenalin content and other indices approached normal levels and, after 30 days, were the same as control levels, although cardiac functional reserve was decreased. Thyroidin administration after 15 days had no noticeable effect. A detailed table shows changes in 17 indices of myocardial contractile function during hypodynamia.

Pruss, G. M.↗
NASA NTRS1980

Forecast of long term coal supply and mining conditions: Model documentation and results

A coal industry model was developed to support the Jet Propulsion Laboratory in its investigation of advanced underground coal extraction systems. The model documentation includes the programming for the coal mining cost models and an accompanying users' manual, and a guide to reading model output. The methodology used in assembling the transportation, demand, and coal reserve components of the model are also described. Results presented for 1986 and 2000, include projections of coal production patterns and marginal prices, differentiated by coal sulfur content.

Source record↗
NASA NTRS1980

Electrochemical Orbital Energy Storage (ECOES) technology program

The versatility and flexibility of a regenerative fuel cell power and energy storage system is considered. The principal elements of a Regenerative Fuel Cell System combine the fuel cell and electrolysis cell with a photovoltaic solar cell array, along with fluid storage and transfer equipment. The power output of the array (for LEO) must be roughly triple the load requirements of the vehicle since the electrolyzers must receive about double the fuel cell output power in order to regenerate the reactants (2/3 of the array power) while 1/3 of the array power supplies the vehicle base load. The working fluids are essentially recycled indefinitely. Any resupply requirements necessitated by leakage or inefficient reclamation is water - an ideal material to handle and transport. Any variation in energy storage capacity impacts only the fluid storage portion, and the system is insensitive to use of reserve reactant capacity.

Mcbryar, H.↗
NASA NTRS1980

Next generation communications satellites: Multiple access and network studies

Following an overview of issues involved in the choice of promising system architectures for efficient communication with multiple small inexpensive Earth stations serving hetergeneous user populations, performance evaluation via analysis and simulation for six SS/TDMA (satellite-switched/time-division multiple access) system architectures is discussed. These configurations are chosen to exemplify the essential alternatives available in system design. Although the performance evaluation analyses are of fairly general applicability, whenever possible they are considered in the context of NASA's 30/20 GHz studies. Packet switched systems are considered, with the assumption that only a part of transponder capacit is devoted to packets, the integration of circuit and packet switched traffic being reserved for further study. Three types of station access are distinguished: fixed (FA), demand (DA), and random access (RA). Similarly, switching in the satellite can be assigned on a fixed (FS) or demand (DS) basis, or replaced by a buffered store-and-forward system (SF) onboard the satellite. Since not all access/switching combinations are practical, six systems are analyzed in detail: three FS SYSTEMS, FA/FS, DA/ES, RA/FS; one DS system, DA/DS; and two SF systems, FA/SF, DA/SF. Results are presented primarily in terms of delay-throughput characteristics.

Stern, T. E.↗
NASA NTRS1979

Systems level feasibility study for the detection of extra-solar planets. Volume 1: Infrared interferometer (IRIS) known as the Stanford Concept

A sensor system for the direct detection of extrasolar planets from an Earth orbit is evaluated: a spinning, infrared interferometer (IRIS). It is shuttle deployed, free flying, requires no on-orbit assembly and no reservicing over a design life of five years. The sensor concept and the mission objectives are reviewed, and the performance characteristics of a baseline sensor for standard observation conditions are derived. A baseline sensor design is given and the enabling technology discussed. Cost and weight estimates are performed; and a schedule for an IRIS program including technology development and assessment of risk are given. Finally, the sensor is compared with the apodized visual telescope sensor (APOTS) proposed for the same mission. The major conclusions are: that with moderate to strong technology advances, particularly in the fields of long life cryogenics, dynamical control, mirror manufacturing, and optical alignment, the detection of a Jupiter like planet around a Sunlike star at a distance of 30 light years is feasible, with a 3 meter aperture and an observation time of 1 hour. By contrast, major and possibly unlikely breakthroughs in mirror technology are required for APOTS to match this performance.

Source record↗
NASA NTRS1980

SARSAT: A rescue system for ships and airplanes

The SARSAT rescue system is described and alternative systems discussed, with SARSAT functioning as either independent satellite within an emergency call system or as an additional search and rescue payload of another satellite system. Geostationary and polar orbits are compared. A low cost SARSAT rescue system utilizing four satellites in a quasi solar, sun synchronized orbit at 1000 kilometers is proposed. Three multiple start satellites in a 57 degree orbit, with a fourth satellite in reserve at a lower orbit are described. Alternative transport systems are discussed and a recommended time table from project approval to launch is given.

Source record↗
NASA NTRS1981

ATC simulation of helicopter IFR approaches into major terminal areas using RNAV, MLS, and CDTI

The introduction of independent helicopter IFR routes at hub airports was investigated in a real time air traffic control system simulation involving a piloted helicopter simulator, computer generated air traffic, and air traffic controllers. The helicopter simulator was equipped to fly area navigation (RNAV) routes and microwave landing system approaches. Problems studied included: (1) pilot acceptance of the approach procedure and tracking accuracy; (2) ATC procedures for handling a mix of helicopter and fixed wing traffic; and (3) utility of the cockpit display of traffic information (CDTI) for the helicopter in the hub airport environment. Results indicate that the helicopter routes were acceptable to the subject pilots and were noninterfering with fixed wing traffic. Merging and spacing maneuvers using CDTI were successfully carried out by the pilots, but controllers had some reservations concerning the acceptability of the CDTI procedures.

Tobias, L.↗
NASA NTRS1981

Electrical load management at the Goldstone DSN Complex

A Power Load Management Plan was deveoped which utilizes the unique power generating capabilities of the stations to reduce the stress on the local utility's reserve capacity and reduce the cost of electrical power at the stations. The plan has greatly reduced the cost of Goldstone electrical power by completely eliminating the use of commercial power during the local utility's high usage periods each day.

Rayburn, J. C.↗
NASA NTRS1981

Design description of the Schuchuli Village photovoltaic power system

A stand alone photovoltaic (PV) power system for the village of Schuchuli (Gunsight), Arizona, on the Papago Indian Reservation is a limited energy, all 120 V (d.c.) system to which loads cannot be arbitrarily added and consists of a 3.5 kW (peak) PV array, 2380 ampere-hours of battery storage, an electrical equipment building, a 120 V (d.c.) electrical distribution network, and equipment and automatic controls to provide control power for pumping water into an existing water system; operating 15 refrigerators, a clothes washing machine, a sewing machine, and lights for each of the homes and communal buildings. A solar hot water heater supplies hot water for the washing machine and communal laundry. Automatic control systems provide voltage control by limiting the number of PV strings supplying power during system operation and battery charging, and load management for operating high priority at the expense of low priority loads as the main battery becomes depleted.

Ratajczak, A. F.↗
NASA NTRS1981

A computer-aided design system geared toward conceptual design in a research environment

A computer-aided design system has recently been developed specifically for the small research group environment. The system is implemented on a Prime 400 minicomputer linked with a CDC 6600 computer. The goal was to assign the minicomputer specific tasks, such as data input and graphics, thereby reserving the large mainframe computer for time-consuming analysis codes. The basic structure of the design system consists of GEMPAK, a computer code that generates detailed configuration geometry from a minimum of input; interface programs that reformat GEMPAK geometry for input to the analysis codes; and utility programs that simplify computer access and data interpretation. The working system has had a large positive impact on the quantity and quality of research performed by the originating group. This paper describes the system, the major factors that contributed to its particular form, and presents examples of its application.

STACK S. H.↗
NASA NTRS1981

Simulated aircraft takeoff performance with frosted wings

The absolute and relative safety of certain nocturnal frost formations on general aviation and transport type airfoils is evaluated by a computer simulation program. The frost layer aerodynamic penalty and takeoff program was used to calculate the frost thickness distribution on an airfoil with time, as well as the aerodynamic penalties associated with the frost layer during takeoff. The program was validated by nocturnal frost formation experiments on an inclined flat plate and by comparisons with documented aerodynamic penalties of an arbitrarily roughened airfoil. For various meteorological conditions and runway take-off velocities, a frost layer can be determined that produces no aerodynamic penalty, thus inferring the absolute safety of the airfoil with respect to frost. The relative safety of a frosted airfoil depends on the ability of the engine power reserve to overcome both as much as doubling of airfoil drag and an increased stall speed due to lift penalties.

Dietenberger, M. A.↗
NASA NTRS1981

Aerodynamic design data for a cruise-matched high performance single-engine airplane

Design data are presented for a class of high-performance single-engine business airplanes. The design objectives include a cruise speed of 300 knots, a cruise altitude of 10,700 m (35,000 ft), a cruise payload of six passengers (including crew and baggage), and a no-reserves cruise range of 1300 n.mi. Two unconventional aerodynamic technologies were evaluated: the individual and combined effects of cruise-matched wing loading and of a natural laminar flow airfoil were analyzed. The trade-off data presented illustrate the ranges of wing geometries, propulsion requirements, airplane weights, and aerodynamic characteristics which are necessary to meet the design objectives. Very large design and performance improvements resulted from use of the aerodynamic technologies evaluated. It is shown that the potential exists for achieving more than 200-percent greater fuel efficiency than is achieved by current airplanes capable of similar cruise speeds, payloads, and ranges.

Holmes, B. J.↗