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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 685 records · Page 38
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Primary and secondary nuclei in high-energy cosmic rays

Charge and particle trajectory measurements during a balloon-borne experiment observing the composition of cosmic rays, are interpreted by plotting differential intensities of various nuclei of both primary and secondary origin above 3 GeV/nucleon. The large spectral difference between carbon plus oxygen and iron is confirmed in the difference between their secondary products. This large difference cannot be explained as being solely due to propagation effects and it is concluded that preferential acceleration of heavy nuclei due to a source effect is present.

Ormes, J. F.↗
NASA NTRS1972

Semicircular canals as a primary etiological factor in motion sickness.

Data are presented which support the view that the semicircular canals of humans can act as the essential factor for the production of motion sickness and the evocation of symptoms characteristic of this malady in the absence of 'motion.' Quantitative grading of acute symptoms demonstrated that motion sickness can be evoked by stimuli which are adequately provocative and unique for the canals. These results are compared with those of two provocative rotational tests that introduce Coriolis (cross-coupled angular acceleration) forces or generate a rotating linear acceleration vector. Wide interindividual differences but only slight intraindividual differences among the six provocative test conditions are revealed, indicating that individuals usually possess an overall susceptibility to motion which is relatively independent of its type. The fact that typical symptoms of motion sickness were also produced by bithermal irrigation of several subjects who represented a wide range of susceptibility adds to the evidence that semicircular canals can act as the primary etiological factor in this malady.

Miller, E. F., II↗
NASA NTRS1973

Ablation debris and primary micrometeoroids in the stratosphere.

Analysis of micrometer-sized stratospheric particulates suggests that the majority of extraterrestrial material in the atmosphere is the product of ablation of larger bodies. Ablation debris is of considerable interest because of the possibility that much of it may have originated from classes of easily fragmented meteoroids that are incapable of surviving atmospheric entry to become meteorites. Comparison is made between the elemental abundance patterns found in stratospheric particulates and that found in fusion crusts of primitive meteorite types. Also discussed are criteria for distinguishing ablation products from primary unablated micrometeoroids.

Brownlee, D. E.↗
NASA NTRS1974

Charge composition of high energy heavy primary cosmic ray nuclei

A detailed study of the charge composition of primary cosmic radiation for about 5000 charged nuclei from neon to iron with energies greater than 1.16 GeV/nucleon is presented. Values are obtained after corrections were made for detector dependences, atmospheric attenuation, and solar modulation. New values of 38.5, 32.4, 23.7, and 16.8 g/sq cm for the attenuation mean free paths in air for the same charge groups are presented.

Price, R. D.↗
NASA NTRS1972

Primary cosmic ray particles with z 35 (VVH particles)

Large areas of nuclear emulsions and plastic detectors were exposed to the primary cosmic radiation during high altitude balloon flights. From the analysis of 141 particle tracks recorded during a total exposure of 1.3 x 10 to the 7th power sq m ster.sec., a charge spectrum of the VVH particles has been derived.

Blanford, G. E., Jr.↗
NASA NTRS1974

Space shuttle/food system study. Volume 2, Appendix F: Flight food and primary packaging

The analysis and selection of food items and primary packaging, the development of menus, the nutritional analysis of diet, and the analyses of alternate food mixes and contingency foods is reported in terms of the overall food system design for space shuttle flight. Stowage weights and cubic volumes associated with each alternate mix were also evaluated.

Source record↗
NASA NTRS1974

Effect of primary-zone equivalence ratio and hydrogen addition on exhaust emission in a hydrocarbon-fueled combustor

The effects of reducing the primary-zone equivalence ratio on the exhaust emission levels of oxides of nitrogen, carbon monoxide, and unburned hydrocarbons in experimental hydrocarbon-fueled combustor segments at simulated supersonic cruise and idle conditions were investigated. In addition, the effects of the injection of hydrogen fuel (up to 4 percent of the total weight of fuel) on the stability of the hydrocarbon flame and exhaust emissions were studied and compared with results obtained without hydrogen addition.

Norgren, C. T.↗
NASA NTRS1974

Search for antinuclei in the primary cosmic rays

Results of a search for primary cosmic-ray antinuclei with charges 2 less than or equal to Z less than or equal to 26 with rigidities above 5 GV/c using a second-generation superconducting magnetic spectrometer with an average bending power of 5.1 kG-m. The addition of new data doubles the sample of cosmic-ray nuclei previously reported and greatly increases the percentage of the more highly charged nuclei.

Smoot, G. F.↗
NASA NTRS1974

Primary cosmic ray particles with Z greater than 35 /VVH particles/

Large areas of nuclear emulsions and plastic detectors were exposed to the primary cosmic radiation during high-altitude balloon flights. From an analysis of 141 particle tracks recorded during a total exposure of 13,000,000 sq m-ster-sec, a charge spectrum of the VVH particles has been derived.

Blanford, G. E., Jr.↗
NASA NTRS1974

Measurement of separate electron and positron spectra in the primary cosmic rays from 5 to 50 GeV

A magnetic spectrometer and lead-plate spark chamber have been used to measure separate primary cosmic-ray electrons and positrons up to 50 GeV. Separation of these particles from the background was accomplished with a new technique combining both selective trigger and observation, in the lead-plate chamber, of bremsstrahlung photons that were created in a thin radiator placed above the spectrometer. The results of efficiency and rejection calibrations with accelerator tests and Monte Carlo calculations are presented, as well as preliminary data from a balloon-flight exposure of the apparatus.

Buffington, A.↗
NASA NTRS1974

Evidence for primary interstellar cosmic-ray electrons

We have performed a comparative study of the absolute solar modulation of cosmic-ray positrons and electrons. We find that the interstellar electron spectrum, which is described by a power-law slope at higher energies, must flatten below about 100 MeV, that a significant fraction of interstellar cosmic-ray electrons must originate in primary sources, and that the rigidity dependence of the interplanetary cosmic-ray diffusion coefficient, R raised to the power of alpha, changes from alpha greater than zero at higher rigidities to alpha -1 below about 60 MV.

Cummings, A. C.↗
NASA NTRS1974

Measurements of the primary cosmic ray electron spectrum from 1965 to 1972

Data on the primary electron spectrum from 5 MeV to 30 GeV are presented for a large number of balloon flights in the years 1965-1972. A new much larger area electron telescope was introduced to these studies in 1971 and the results from this new telescope are given and compared with earlier results. Detailed electron spectra are presented and the effects of solar modulation are examined over a wide energy range. The phase lag or hysteresis in the electron intensity observed after 1969 is also examined between 40 MeV and 1 GeV.

Webber, W. R.↗
NASA NTRS1974

Testing for hydrogen environment embrittlement - Primary and secondary influences

A somewhat phenomological overview of the hydrogen embrittlement process, both internal as well as external, is presented in a effort to make more clear the type of parameters which must be considered in the selection of a test method and test procedure so that the resulting data may be meaningfully applied to real engineering structures. What are believed to be the three primary influences on the embrittlement process are considered - the original location and form of the hydrogen, the transport reactions involved in the transport of hydrogen from its origin to some point it can interact with the metal to cause embrittlement, and the embrittlement interaction itself. Additionally, a few of the large number of secondary influences on the embrittlement process are discussed, for example, the influence of impurity species in the environment, surface hydride films, and surface oxide films.

Nelson, H. G.↗
NASA NTRS1974

Fabrication of experimental three-meter space telescope primary and secondary mirror support structure

The fabrication of prototype titanium alloy primary and secondary mirror support structures for a proposed experimental three-meter space telescope is discussed. The structure was fabricated entirely of Ti-6Al-4V tubing and plate. Fabrication included the development of procedures including welding, forming, and machining. Most of the structures was fabricated by gas-shielding tungsten-arc (GTA) welding with several major components fabricated by high frequency resistance (HFR) welding.

Mishler, H. W.↗
NASA NTRS1975

The extra-galactic contribution to the primary cosmic-ray flux

In previous studies it has been shown that a good case can be made for supposing that a large fraction of the primary cosmic rays is of extra-galactic origin. These ideas are reviewed here, and the most recent observations and theoretical suggestions bearing on the problem are described.

Burbidge, G. R.↗
NASA NTRS1975

Primary electric propulsion thrust subsystem definition

A review is presented of the current status of primary propulsion thrust subsystem (TSS) performance, packaging considerations, and certain operational characteristics. Thrust subsystem related work from recent studies by Jet Propulsion Laboratories (JPL), Rockwell and Boeing is discussed. Existing performance for 30-cm thrusters, power processors and TSS is present along with projections for future improvements. Results of analyses to determine (1) magnetic field distributions resulting from an array of thrusters, (2) thruster emitted particle flux distributions from an array of thrusters, and (3) TSS element failure rates are described to indicate the availability of analytical tools for evaluation of TSS designs.

Masek, T. D.↗
NASA NTRS1974

Electric propulsion system design and development for primary propulsion applications

An electric thrust subsystem technology development program to demonstrate the readiness of primary electric propulsion for flight applications is described. The development program is based on a subsystem design sufficiently flexible to be applicable to a broad range of mission requirements with minimum impact on the subsystem elements or interface designs. The effort includes development and qualification testing of new subsystem elements, the assembly and test of subsystem models to verify the physical and functional interfaces of the subsystem with other spacecraft subsystems, and the investigation of the effects of thrust subsystem operation on all aspects of spacecraft performance. The present status of this effort and some of the results so far obtained are presented.

Kerrisk, D. J.↗
NASA NTRS1975

Auger electron spectroscopy at high spatial resolution and nA primary beam currents

An experimental Auger microprobe system is described which incorporates a field-emission electron gun and total beam currents in the nanoampere range. The distinguishing characteristics of this system include a large multistation UHV specimen chamber, pulse counting and fully digital Auger signal-processing techniques, and digital referencing methods to eliminate the effects of beam instabilities. Some preliminary results obtained with this system are described, and it is concluded that field-emission electron sources can be used for high-resolution Auger electron spectroscopy with primary-beam spots of less than 100 nm and beam currents of the order of 1 nA.

Todd, G.↗