Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Step”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 667 records · Page 37
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Generating social impact scenarios, a key step in making technology assessment studies

The social impact scenario, a method used to trace the effects of new technological applications, is discussed. The research seeks to anticipate the secondary social impacts that arise from: (1) government or private programs that cope with major social problems like poverty, environmental pollution, or public safety; and (2) a concerted national effort to achieve a widely supported specific goal like landing a man on the moon or finding a cure for cancer.

Jones, M. V.↗
NASA NTRS1972

Possible steps in the evolutionary development of bird navigation

Hypotheses are presented to explain the evolutionary development of navigational ability in migratory birds. Areas of discussion to describe the possible techniques are: (1) sun compass, (2) bicoordinate navigation, (3) star compass, (4) wind cues, (5) earth magnetic field, and (6) landscape features. It is concluded that landscape is the single most important cue for orientation of nonmigratory birds. The long range migratory birds appear to use a combination of cues with the relative importance of the cue dependent upon the species of the bird involved.

Bellrose, F. C.↗
NASA NTRS1972

A possible step in the origin of the genetic code.

It is suggested that the earliest coding polynucleotides contained a high proportion of alternating sequences of purines and pyrimidines, and that these sequences coded for polypeptides in which hydrophobic and hydrophylic amino acids alternated. Structural properties of such alternating polypeptides are discussed.

Orgel, L. E.↗
NASA NTRS1973

An initial step: A demonstration project

To initiate the transition into a clean and diverse energy environment independent of fossil-based fuels, the rapid development of a subsonic, hydrogen-fueled aircraft is recommended. Tables are presented on characteristics of synthetic fuels, comparisions with JP-4 and gasoline, comparison of nitric oxide emissions from hydrocarbon and hydrogen fuels vs. final flame temperature, and sensitivity limits of LH2 detectors.

Source record↗
NASA NTRS1975

High-voltage stepping supply with fast settling time

Waveform generator is used to derive low-voltage staircase waveform that feeds relatively long response time power supply. Power supply has high output voltage that is predetermined multiple of the input voltage.

Doong, H.↗
NASA NTRS1974

Feasibility study of a step scanned omnidirectional communications antenna for an international magnetospheric explorer spacecraft

The results of this study has indicated that omnidirectional antennas requiring directive gains steered off broadside are limited by the feed system efficiencies. The directive gain can be increased to offset the feed losses, but this approach leads quickly to diminishing returns. While gains of 4.8 db appear feasible, a system gain of 3.0 db is considered practical. These results apply to antenna configurations limited in packaging volume to 10 cm diameter by 61 cm length.

Herskind, R. E.↗
NASA NTRS1975

Generating social impact scenarios: A key step in making technology assessment studies

The MITRE methodological studies were conducted to define relevant questions in relation to the concept of total impact analysis and to provide a procedure for integrating diverse checklists of questions which trace the initial and secondary impacts of any major technological application or of society's attempts to respond to or redirect that application. Some of the results of that study are presented in tabular form.

Jones, M. V.↗
NASA NTRS1978

Step motor damping for high-inertia loads

Brushless tachometer generates signals for moving large and varying loads precisely. Stepper waveform generator sends short sequence of pulses to instruct control logic circuit to perform its function-that is, to select proper windings and directions of excitation to drive and damp motor. Control logic circuit bases decisions on following logic signals, derived from tachometer: rate direction, rate threshold, and position.

Veillette, L. J.↗