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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 613 records · Page 34
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Interaction between radiation effects, gravity and other environmental factors in Tribolium confusum.

The development of the flour beetle, Tribolium confusum, was studied through all stages of its life cycle. The results show that for each environmental factor there is a limited range of values within which the organisms are able best to survive and that this optimum range of survival becomes smaller when additional stresses are imposed upon the organism. This has been shown for external temperature, oxygen content of the atmosphere, gravity compensation, and radiation. On Biosatellite II it was shown that Tribolium pupae irradiated in spaceflight exhibited more wing abnormalities than ground controls. Later it was shown that gravity compensation, when combined with irradiation, can induce a similar effect at ground level.

Yang, C. H.↗
NASA NTRS1974

Apollo Saturn 511 effluent measurements from the Apollo 16 launch operations: An experiment

An experiment was performed in conjunction with the Apollo 16 launch to define operational and instrumentational problems associated with launch-vehicle exhaust effluent monitoring. Ground and airborne sampling were performed for CO, CO2, hydrocarbons, and particulates. Sampling systems included filter pads and photometers for particulates and whole-air grab samples for gases. Launch debris was identified in the particulate samples at ground level(taken immediately after launch) and in the airborne measurements (taken 40 to 50 minutes after launch approximately 40 km downwind of the pad). Operational problems were identified and included the need for higher instrumentation mobility and the need for real-time sampling instrumentation as opposed to collection-type samples such as the whole-air grab sample.

Gregory, G. L.↗
NASA NTRS1974

Explorer 45 (S 3-A) observations of the magnetosphere and magnetopause during the 4-5 August 1972, magnetic storm period

The Explorer 45 satellite performed extensive field and particle measurements in the heart of the magnetosphere during the double magnetic storm period of August 4-5, 1972. Both ground level magnetic records and the magnetic field deformations measured along the orbit by the satellite indicated the existence of only a moderate ring current. This was confirmed by the measurements of the total proton energy density less than those observed during the December 1971 and June 1972 magnetic storms. The plasmapause in the noon quadrant was eroded continuously from the onset of the first storm at the beginning of August 4 to an altitude below L = 2.07 at about 18 hours on August 5. During the orbit containing the second sudden commencement a large amount of low frequency electric and magnetic field noise was encountered throughout the entire orbit. A noteworthy observation during this orbit was the contraction of the magnetopause to distances inside the satellite at L = 5.2.

Hoffman, R. A.↗
NASA NTRS1974

Atmospheric effects on remote sensing of non-uniform temperature sources

The effects are considered of an absorbing, emitting, and scattering atmosphere upon the remote sensing of surface areas having non-uniform intensity. These atmospheric effects may be significant in determination, by remote sensing, of non-uniform surface temperature distributions, and the results of the investigation are applicable in such cases. Analytical methods and a digital computational program are presented, expressing the results in terms of contrast and contrast transmittance between two adjacent emitting areas having unequal intensities, in the presence of a additional disturbing emitters. In the computational procedure, emitting areas are replaced by point-source emitters, each assigned and effective intensity based upon the intensity of the area it replaces. Absorbing, emitting, and scattering behavior of the atmosphere may be specified in the computational procedure either by means of analytical atmospheric models or by means of calibrating ground level emitters.

Mcneill, W. A.↗
NASA NTRS1974

Preliminary design of a 100 kW turbine generator

The National Science Foundation and the Lewis Research Center have engaged jointly in a Wind Energy Program which includes the design and erection of a 100 kW wind turbine generator. The machine consists primarily of a rotor turbine, transmission, shaft, alternator, and tower. The rotor, measuring 125 feet in diameter and consisting of two variable pitch blades operates at 40 rpm and generates 100 kW of electrical power at 18 mph wind velocity. The entire assembly is placed on top of a tower 100 feet above ground level.

Puthoff, R. L.↗
NASA NTRS1974

Apollo experience report: Spacecraft structure subsystem

The flightworthiness of the Apollo spacecraft structure was verified primarily through a rigorous, vehicle level, ground test program and flight tests. The failures and anomalies encountered during this testing were the major factors considered in determining necessary modifications to the basic design of the spacecraft structure. In this report, these failures, their causes, and their resolutions are discussed. A description of the spacecraft structure and discussions of the ground and flight test programs are presented.

Smith, P. D.↗
NASA NTRS1974

Jet engine soot emission measured at altitude

The state of knowledge concerning engine design to minimize air pollution is believed to be such that emission products can be reliably predicted while the engine is still on the drawing board. More effort is now being made to measure emission products from engines operating under cruise conditions. The use of an instrumented aircraft to obtain the appropriate data is perhaps a more realistic and less expensive approach. The results of this study taken at face value indicate that the emission index of typical jet engines calculated from the ground level measurements is comparable to the actual in-flight emission index for altitudes up to 30,000 ft.

Rosen, J. M.↗
NASA NTRS1974

The phase lag effect in the cosmic ray modulation during solar cycle twenty

In this analysis of the phase-lag effect we utilize more extensive primary proton and helium spectral data from balloon studies of the University of New Hampshire group, from the Pioneer 8 and 9 spacecraft, and from ground-level monitors during 1965-72. If the rigidity dependence of the diffusion coefficient at earth did not change from 1968-72, then the data imply the nonseparability of the radial and rigidity parts of the diffusion coefficient.

Lockwood, J. A.↗
NASA NTRS1974

Data on incident solar energy

Instrumentation for solar irradiance monitoring, and radiation scales are discussed in a survey of incident solar energy data. The absolute accuracy and intrinsic reliability of the values of the solar constant and zero air mass solar spectrum proposed by the Institute of Environmental Sciences as an ASTM standard are evaluated. Extraterrestrial observations are used for deriving solar irradiance data at ground level for widely varying atmospheric parameters, with special reference to air pollution. The effects of diffuse sky radiance and those of varying slopes of the solar energy collecting surface are examined. Average values of solar energy available at different locations in the United States are included.

Thekaekara, M. P.↗
NASA NTRS1974

Incoherent scatter measurements of E region conductivities and currents in the auroral zone

Data taken by incoherent scatter radar have been used to investigate ionospheric conductivities and electrical currents. During quiet days, the conductivities appear to vary in a way consistent with ionization arising from solar EUV radiation. In the evening hours, enhancements in the northward electric field are found to precede small increases in the conductivities. Strong enhancements of the Hall conductivity relative to the Pedersen conductivity occur during negative bays when the electric field is in a southwestward direction. The ionospheric currents calculated in the geomagnetic east-west direction are in good agreement with the H component measured by a nearby magnetometer; this result indicates that the current causing the ground level magnetic fluctuations is a broad horizontal sheet current. The north-south ionospheric current, however, consistently disagrees with the observed D component in a manner that cannot easily be explained unless currents parallel to the earth's magnetic field are present.

Brekke, A.↗
NASA NTRS1975

Handbook for estimating toxic fuel hazards

Computer program predicts, from readily available meteorological data, concentration and dosage fields downwind from ground-level and elevated sources of toxic fuel emissions. Mathematical model is applicable to hot plume rise from industrial stacks and should also be of interest to air pollution meteorologists.

Dumbauld, R. K.↗
NASA NTRS1974

Engineering simulation development and evaluation of the two-segment noise abatement approach conducted in the B-727-222 flight simulator

Profile modification as a means of reducing ground level noise from jet aircraft in the landing approach is evaluated. A flight simulator was modified to incorporate the cockpit hardware which would be in the prototype airplane installation. The two-segment system operational and aircraft interface logic was accurately emulated in software. Programs were developed to permit data to be recorded in real time on the line printer, a 14-channel oscillograph, and an x-y plotter. The two-segment profile and procedures which were developed are described with emphasis on operational concepts and constraints. The two-segment system operational logic and the flight simulator capabilities are described. The findings influenced the ultimate system design and aircraft interface.

Nylen, W. E.↗
NASA NTRS1975

Interplanetary magnetic field data book

An interplanetary magnetic field (IMF) data set is presented that is uniform with respect to inclusion of cislunar IMF data only, and which has as complete time coverage as presently possible over a full solar cycle. Macroscale phenomena in the interplanetary medium (sector structure, heliolatitude variations, solar cycle variations, etc.) and other phenomena (e.g., ground level cosmic-ray events) for which knowledge of the IMF with hourly resolution is necessary, are discussed. Listings and plots of cislunar hourly averaged IMP parameters over the period November 27, 1963, to May 17, 1974, are presented along with discussion of the mutual consistency of the IMF data used herein. The magnetic tape from which the plots and listings were generated, which is available from the National Space Science Data Center (NSSDC), is also discussed.

King, J. H.↗
NASA NTRS1975

Digital transmitter for data bus communications system

An improved digital transmitter for transmitting serial pulse code modulation (pcm) data at high bit rates over a transmission line is disclosed. When not transmitting, the transmitter features a high output impedance which prevents the transmitter from loading the transmission line. The pcm input is supplied to a logic control circuit which produces two discrete logic level signals which are supplied to an amplifier. The amplifier, which is transformer coupled to the output isolation circuitry, converts the discrete logic level signals to two high current level, ground isolated signals in the secondary windings of the coupling transformer. The latter signals are employed as inputs to the isolation circuitry which includes two series transistor pairs operating into a hybrid transformer functioning to isolate the transmitter circuitry from the transmission line.

Proch, G. E.↗
NASA NTRS1974

The Out of Service Guest Pilot Evaluation of the Two-segment Noise Abatement Approach in the Boeing B727-200

Guest pilot evaluation results of an approach profile modification for reducing ground level noise under the approach of jet aircraft runways are reported. Evaluation results were used to develop a two segmented landing approach procedure and equipment necessary to obtain pilot, airline, and FAA acceptance of the two segmented flight as a routine way of operating aircraft on approach and landing. Data are given on pilot workload and acceptance of the procedure.

Nylen, W. E.↗
NASA NTRS1975

The 100 kW experimental wind turbine generator project

The Energy Research and Development Administration and the NASA Lewis Research Center engaged jointly in a Wind Energy Program which included the design and erection of a 100 kW wind turbine generator. This test machine consists of a rotor turbine, transmission, shaft, alternator, and tower. The rotor, measuring 125 feet in diameter and consisting of two variable pitch blades, operates at 40 rpm and generates 100 kW of electrical power at a wind velocity of 18 mph. The entire assembly is placed on top of a tower 100 feet above ground level. The machine was scheduled to be ready for operation in August, 1975.

Puthoff, R. L.↗
NASA NTRS1975

The spectrum of cosmic electrons with energies between 6 and 100 GeV

Results are presented for an experimental determination of the spectrum of cosmic electrons with energies between 6 and 100 GeV. The balloon-borne hodoscope and detector are described, and separation of cosmic electrons from the nuclear background is outlined. The spectra of cosmic primary and ground-level secondary electrons are discussed, and the spectral intensities of both types of particles are found to have separate power-law dependences on the electron energy. On the basis of the steepness of the spectrum of cosmic electrons relative to that of nuclei, it is concluded that either the injection spectrum of electrons is steeper than that of nuclei, or the electron spectrum is steepened by Compton/synchotron losses in the examined energy range.

Meegan, C. A.↗
NASA NTRS1976

Differential absorption and scattering sensitivity predictions

A set of general equations for evaluating the sensitivity of the Differential Absorption and Scattering (DAS) technique based upon a conventional analysis of statistical errors is derived. The equations are put in a proper form for evaluating total column density and range resolved concentration measurements of a variety of atmospheric species. The derived equation are subsequently used to analyze the sensitivity of DAS in three specific applications assuming realistic parameters for the optical and electronic components of proposed DAS systems. The three DAS applications evaluated are: (1) measurement of nitrogen at ground levels over a horizontal path; (2) measurement of atmospheric ozone depletion in the wake of a jet engine at 20 km altitude; and (3) measurements of the ozone distribution in the atmosphere from an orbiting space platform, in a downward viewing mode. The results of this study have shown that with reasonable laser energy and telescope receiver dimensions, DAS is capable of meeting requirements for performing these measurements.

Thompson, R. T., Jr.↗