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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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NASA NTRS1983

Lamb pulse observed in nature

It is shown that seismograms observed at Longmire, Washington, for four eruptions of Mt. St. Helens, those on May 18, June 13, August 7, and August 8, 1980, can be interpreted as Lamb pulses excited by a nearly vertical single force representing the counter force of the eruption. These data furnish reliable estimates of the impulse of the force K (time integral of the force), from which the total momentum and the kinetic energy, E, of the ejecta associated with the eruption can be estimated. The estimates made of K are 1.4 x 10 to the 19th, 1.4 x 10 to the 16th, 3.7 x 10 to the 15th, and 2.8 x 10 to the 15th dynes-sec for the four eruptions (given chronologically). The corresponding estimates for E range from 0.70 to 2.6 x 10 to the 23rd, 0.70 to 2.6 x 10 to the 20th, 1.9 x 10 to the 19th, and 1.4 to 5.3 x 10 to the 19th erg using values of ejecta velocity ranging from 100 to 375 m/sec. The ratio of K to the amplitude of the air wave excited by the eruption is found to be 20 to 40 times larger for the main event on May 18 than for the other events, indicating a significant difference in the eruptive mechanism. A digital seismograph in the vicinity of a volcano is shown to provide a simple means for quantifying the explosive power of a volcanic eruption.

Kanamori, H.↗
NASA NTRS1983

Hf chronometer for the early solar system

It is now widely believed that Al-26 (half-life, 7.2 x 10 to the 5th yr) and Pd-107 (half-life, 6.5 x 10 to the 6th yr) were present in the early solar system. The nucleosynthetic event responsible for the production of these nuclei must therefore have occurred no more than a few million years before the formation of solid bodies. It is possible that this event also gave a rise to the I-129 believed to be present in the early solar system. The last event to contribute Pu-244 to the solar system, however, occurred approximately 10 to the 8th yr before the time of solidification. It is noted that this latter time scale is also consistent with the lack of evidence for a Cm-247 chronometer. It is proposed that Hf-182 (half-life, 9 x 10 to the 6th yr) can resolve the question whether heavy-element nonactinide nucleosynthesis occurred during the (Al-26)-producing event. It is believed that an answer to this question will help to clarify the chronology of the formation of the solar system and will help to determine the astrophysical sites of heavy-element nucleosynthesis.

Norman, E. B.↗
NASA NTRS1983

Space shuttle launch vehicle aerodynamic uncertainties: Lessons learned

The chronological development and evolution of an uncertainties model which defines the complex interdependency and interaction of the individual Space Shuttle element and component uncertainties for the launch vehicle are presented. Emphasis is placed on user requirements which dictated certain concessions, simplifications, and assumptions in the analytical model. The use of the uncertainty model in the vehicle design process and flight planning support is discussed. The terminology and justification associated with tolerances as opposed to variations are also presented. Comparisons of and conclusions drawn from flight minus predicted data and uncertainties are given. Lessons learned from the Space Shuttle program concerning aerodynamic uncertainties are examined.

Hamilton, J. T.↗
NASA NTRS1983

MOD-2 wind turbine development

The development of the Mod-2 turbine, designed to achieve a cost of electricity for the 100th production unit that will be competitive with conventional electric power generation is discussed. The Mod-2 wind turbine system (WTS) background, project flow, and a chronology of events and problem areas leading to Mod-2 acceptance are addressed. The role of the participating utility during site preparation, turbine erection and testing, remote operation, and routine operation and maintenance activity is reviewed. The technical areas discussed pertain to system performance, loads, and controls. Research and technical development of multimegawatt turbines is summarized.

Gordon, L. H.↗
NASA NTRS1983

Sm-Nd isotopic systematics of the ancient Gneiss complex, southern Africa

In order to shed some new light on the question of the absolute and relative ages of the Ancient Gneiss Complex and Onverwacht Group, a Sm-Nd whole-rock and mineral isochron study of the AGC was begun. At this point, the whole-rock study of samples from the Bimodal Suite selected from those studied for their geochemical characteristics by Hunter et al., is completed. These results and their implications for the chronologic evolution of the Kaapvaal craton and the sources of these ancient rocks are discussed.

Carlson, R. W.↗
NASA NTRS1984

Mineralogic and petrologic studies of meteorites and lunar samples

During a 13 year period beginning in 1971, the Extraterrestrial Petrology Group examined lunar soils from all 6 Apollo missions and those returned by the Soviet Luna 16, Luna 20, and Luna 24 missions. In addition, the properties and apparent origin of the carbonaceous chondrites were examined. Chondrules, calcium-aluminum-rich inclusions (CAI) and the fine grained matrix materials that accompany chondrules and CAI's in primitive meteorites were investigated. The effects of planetary hydrothermal alteration of matrix materials in the C1 chondrite was also investigated. Full length papers and extended abstracts published during the grant are listed chronologically.

Wood, J. A.↗
NASA NTRS1981

Pacific Basin Communication Study, volume 2

Users' meeting summary report, chronology of visits, economic data for forum countries, techniques used in the study, communication choices, existing resources in the Pacific Basin, and warc 79 region 3 rules and regulations were presented in volume 2.

Young, E. L.↗
NASA NTRS1984

Turbulence modeling

A survey designed to provide an introduction to the subject of turbulence modeling, and to explain the need for such models is given. The subject is developed along chronological lines since this provides a logical development plan and also because it then moves from relatively simple phenomenological models through more complicated procedures and ultimately to the subject of large-eddy simulation.

Murphy, J. D.↗
NASA NTRS1983

NASA, the first 25 years: 1958 - 1983

Because it is impossible to describe the 25 years of NASA's research and missions in detail, this book is designed to provide a reference base from which teachers can develop classroom concepts and activities. It begins with a prologue, a brief history of the National Advisory Committee for Aeronautics, NASA's predecessor. Succeeding chapters are devoted to major NASA programs, in alphabetical order; within the chapters projects are listed chronologically. Each chapter concludes with ideas for the classroom and space for notes and new information the user may wish to add.

Dalelio, J.↗
NASA NTRS1984

Support interference of wind tunnel models: A selective annotated bibliography

This bibliography, with abstracts, consists of 143 citations arranged in chronological order by dates of publication. Selection of the citations was made for their relevance to the problems involved in understanding or avoiding support interference in wind tunnel testing throughout the Mach number range. An author index is included.

Tuttle, M. H.↗
NASA NTRS1984

Large, horizontal-axis wind turbines

Development of the technology for safe, reliable, environmentally acceptable large wind turbines that have the potential to generate a significant amount of electricity at costs competitive with conventional electric generating systems are presented. In addition, these large wind turbines must be fully compatible with electric utility operations and interface requirements. There are several ongoing large wind system development projects and applied research efforts directed toward meeting the technology requirements for utility applications. Detailed information on these projects is provided. The Mod-O research facility and current applied research effort in aerodynamics, structural dynamics and aeroelasticity, composite and hybrid composite materials, and multiple system interaction are described. A chronology of component research and technology development for large, horizontal axis wind turbines is presented. Wind characteristics, wind turbine economics, and the impact of wind turbines on the environment are reported. The need for continued wind turbine research and technology development is explored. Over 40 references are sited and a bibliography is included.

Linscott, B. S.↗
NASA NTRS1984

Meteorite bombardment and dating of planetary surfaces

Dating by measurement of impact crater frequencies developed in the past years primarily on the basis of the data from the missions to the Moon and Mars. The method allows a good relative dating to be obtained and the moons of Jupiter and Saturn through photographic analyses. A cratering chronology was obtained for the period between the oldest Moon crust (4.3 to 4.4 billion years) to the present time which gives a good absolute dating of any areas of the Moon's surface.

Neukum, G.↗
NASA NTRS1984

Partition coefficients of Hf, Zr, and REE between phenocrysts and groundmasses

Partition coefficients of Hf, Zr, and REE between olivine, orthopyroxene, clinopyroxene, plagioclase, garnet, amphibole, ilmenite, phlogopite, and liquid are presented. Samples consist of megacrysts in kimberlite, phenocrysts in alkaline basalts, tholeiitic basalts and andesitic to dacitic rocks, and synthetic garnet and clinopyroxene in Hawaiian tholeiites. The Hf-Lu and Zr-Lu elemental fractionations are as large as the Lu-Sm or Lu-Nd fractionation. The Hf and Zr partition coefficients between mafic phenocrysts and liquids are smaller than the Lu partition coefficients, but are similar to the Nd or Sm partition coefficients. The Hf and Zr partition coefficients between ilmenite, phlogopite, and liquid are larger than the Lu partition coefficients for these minerals and their corresponding liquids. The Hf-Zr elemental fractionation does not occur except for extreme fractionation involving Zr-minerals and extremely low fO2. These data have an important bearing on chronological and petrogenetic tracer studies involving the Lu-Hf isotopic system.

Fujimaki, H.↗
NASA NTRS1984

An overview of some monoplanar missile programs

A historical review is presented of some monoplanar missile systems in which the vehicle flight control was similar to that for a conventional aircraft. The review is essentially chronological, beginning prior to World War I, and includes worldwide programs. Illustrative examples of aerodynamic research with monoplanar missiles are presented including some comparisons with cruciform missiles. Some examples of current programs are presented and some particular mission applications for monoplanar systems are discussed.

Spearman, M. L.↗
NASA NTRS1984

An overview of some monoplanar missile programs

A historical review is presented of some monoplanar missile systems in which the vehicle flight control was similar to that for a conventional aircraft. The review is essentially chronological, beginning prior to World War I, and includes worldwise programs. Illustrative examples of aerodynamic research with monoplanar missiles are presented including some comparisons with cruciform missiles. Some examples of current programs are presented and some particular mission applications for monoplanar systems are discussed.

Spearman, M. L.↗
NASA NTRS1984

On the frontier: Flight research at Dryden 1946-1981

The history of flight research at the NASA Hugh L. Dryden Flight Research Center is recounted. The period of emerging supersonic flight technology (1944 to 1959) is reviewed along with the era of flight outside the Earth's atmosphere (1959 to 1981). Specific projects such as the X-15, Gemini, Apollo, and the space shuttle are addressed. The flight chronologies of various aircraft and spacecraft are given.

Hallion, R. P.↗
NASA NTRS1985

Simultaneous cabin and ambient ozone measurements on two Boeing 747 airplanes. Volume 3: October 1978 - July 1979

Measurements of ozone concentrations at cruise altitudes both outside and in the cabin of a Boeing 747SP and Boeing 747-100 airliners in routine commercial service are presented. Plotted and tabulated data are identified by route and are arranged chronologically for each airplane. These data were taken at 5- or 10-min intervals by automated instruments used in the NASA Global Atmospheric Sampling Program (GASP). All GASP cabin ozone data obtained from October 1978 to early July 1979 are presented.

Holdeman, J. D.↗
NASA NTRS1985

Study and Estimation of Planet-crossing Asteroid Populations: Discoveries and Analysis

The populations of the various classes of planet-crossing asteroids, based on the results of the systematic Planet-Crossing Asteroid Survey (PCAS) search program are evaluated. Knowledge of the populations is crucial to the stimation of lunar and terrestrial planet cratering rates from asteroidal and cometary sources needed to establish the chronology of other surface features on those bodies. A secondary objective is to identify the sources of these crater-forming objects and their relative importance in producing the observed planet-crossing asteroid population. Some key PCAS asteroid discoveries relevant to the population problem and the progress in using the available search data to update and refine earlier estimates of the planet-crossing asteroid population are described.

Helin, E. F.↗