Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Tabulation”

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 487 records · Page 27
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Data for NASA's AVE 2 pilot experiment. Part 1: 25-mb sounding data and synoptic charts

Tabulated rawinsonde data at 25-mb intervals from surface to 25 mb is presented for the 54 stations participating in the Atmospheric Variability Experiment 11 pilot experiment which began at 12 GMT on May 11, 1974, and ended at 12 GMT on May 12, 1974. Soundings were made at 3 hour intervals. A brief discussion is included on methods of processing and data accuracy, and synoptic charts prepared from the the data are presented. The area covered by the sounding stations is the eastern United States, east of approximately 105 deg west longitude.

Scoggins, J. R.↗
NASA NTRS1974

Tables and charts of equilibrium normal shock and shock-tube solutions for helium-hydrogen mixtures with velocities to 70 km/sec

Equilibrium thermodynamic and flow properties are presented in tabulated and graphical form for moving, standing, and reflected normal shock waves into helium-hydrogen mixtures representative of proposed outer planet atmospheres. The volumetric compositions of these mixtures are 0.35He-0.65H2, 0.20He-0.80H2, and 0.05He-0.95H2. Properties include pressure, temperature, density, enthalpy, speed of sound, entropy, molecular-weight ratio, isentropic exponent, velocity, and species mole fractions. Incident (moving) shock velocities are varied from 4 to 70 km/sec for a range of initial pressure of 5 N/sq m to 100 kN/sq m. The present results are applicable to shock-tube flows and to free-flight conditions for a blunt body at high velocities. A working chart illustrating idealized shock-tube performance with a 0.20He-0.80H2 test gas and heated helium driver gas is also presented.

Miller, C. G., III↗
NASA NTRS1973

Water-vapor measures - Mt. Lemmon area

Daytime atmospheric water-vapor measures were continued for Mt. Lemmon, the Catalina Observatory, and Tucson. As before (Lunar and Planetary Laboratory Communications, No. 158), the three sets are closely related in terms of their altitude differences, with the average empirically-determined scale-height value, 2.3 km. During the winter and spring of 1971 observations were made for more than 90% of the days. The measures are tabulated and reduced to Mt. Lemmon. The calibration was continued to higher values by means of atmospheric radiosonde data.

Kuiper, G. P.↗
NASA NTRS1973

Possibility of Saturnian synchrotron radiation

Several synchrotron spectra are computed for a hypothetical Saturnian radiation belt. A monoenergetic distribution of relativistic electrons is assumed to exist in a toroidal volume in a dipole magnetic field aligned with the rotation axis. When synchrotron emission is added to the thermal component implied by observations at wavelengths shorter than 50 cm, the upturn in the total emission spectrum can become gradual to quite sharp depending on the critical wavelength and the number density of radiating electrons. As an example, the ranges of magnetic field intensity, and electron energy and density are tabulated for an estimate of the nonthermal component at the longest decimetric wavelength observation. The present observations are insufficient to determine the critical wavelength; but, for several estimates of the magnetic field loading factor, the minimum surface magnetic field intensity and minimum electron number density are computed.

Luthey, J. L.↗
NASA NTRS1974

Free-free absorption of infrared radiation in collisions of electrons with neutral rare-gas atoms

A relationship between the inverse bremsstrahlung absorption cross section and the electron neutral momentum transfer cross section has been utilized to determine the infrared free-free continuum absorption coefficient for the negative ions of helium, neon, argon, krypton, and xenon. The values of the momentum transfer cross section for this calculation have been obtained from experimental measurements. Analytical expressions for the absorption coefficient have also been developed. From the results of this calculation, it is possible to determine the absorption coefficient per unit electron density per neutral atom for temperatures in the range from 2500 to 25,000 K. The results are compared with those from tabulations of previous calculations and those computed from theoretical values of the phase shifts for the elastic scattering of electrons by neutral atoms.

Stallcop, J. R.↗
NASA NTRS1973

Antiphase domains in lunar plagioclase

The paper is a compilation of data on antiphase domains in lunar plagioclase. New observations and reports in the literature are tabulated and discussed. In the pattern which emerges (but is still very incomplete), it appears that b-domains, which except for the An 82 bytownite from the Stillwater complex have only been observed in lunar feldspars, occur in the anorthite range An 80 to 95. Especially in the sodium rich part there seems to be a close relation between an exsolution structure and b-APB's. The c-APB's are found in anorthites An 95 to 100 and for a given An-content they are larger for metamorphic than for volcanic anorthites. Near An 95, c- and b-domains can be observed in the same crystal. The c-domains disappear when heated above 1200 C; they are not affected by heating below 600 C. This implies that calcic anorthite without c-domains must have been rapidly quenched from high temperatures.

Wenk, H.-R.↗
NASA NTRS1974

Operation and performance of a lunar laser ranging station

The Lunar Laser Ranging Experiment has been in continuous operation for about 4 years using the McDonald Observatory 2.7-m telescope. Occupying only a small percentage of the available telescope time, the system is now measuring 350 lunar ranges per year, each with an accuracy of from 10 to 15 cm. This article tabulates the observed signal strengths, the success ratios, and the major operating restrictions that have characterized the daily performance of the experiment. These empirical data can be used to optimize the design of such installations in the future.

Silverberg, E. C.↗
NASA NTRS1973

Nonequilibrium distributions of molecular states in interstellar space

Current knowledge on the components of interstellar space and on interstellar dust clouds (which contain most of the molecules existing in interstellar space) is reviewed. The discovery of molecules by absorption of a microwave continuum or by emission from their own excited state is discussed in historical order, and the interpretation of their spectra is examined. The observed microwave resonances of interstellar molecules are tabulated. Another table shows the approximate column densities of molecules found in the directions of the Orion nebula and of Sagittarius. The various types of nonequilibrium encountered are demonstrated by examples.

Townes, C. H.↗
NASA NTRS1974

Neutrino reactions in strong magnetic field

Presentation of the energy losses due to several neutrinos processes: (1) synchrotron neutrinos, (2) pair annihilation neutrinos, (3) plasmon neutrinos, and (4) photoneutrinos in the presence of a superstrong magnetic field. Numerical results are tabulated and illustrated for several values of densities and temperatures. In the low density regime, the presence of a magnetic field decreases the luminosity, whereas the opposite is true at higher densities. This last effect is, however, almost entirely due to the existence of a new process, the synchrotron neutrinos that disappear when H goes to zero. Even though the overall effect can only be quantitatively ascertained after a complete cooling computation is performed, one should however expect a much lower temperature for neutron star surface than the one computed in the case where H is zero.

Canuto, V.↗
NASA NTRS1974

The peculiar star He 2-177 - A slow nova and a possible X-ray source

The remarkable detail resemblence of the spectrum of the peculiar emission-line star He 2-177 to that of the slow nova RR Telescopii is illustrated by tabulated data and discussed. The evolution of the spectrum since 1965 closely resembles the evolution of RR Tel between 1951 and 1954. A newly determined position of X-ray source 2U 1639-62 makes its identification with He 2-177 less probable than before.

Carlson, E. D.↗
NASA NTRS1974

Effect of mean-velocity profile shapes on sound transmission through two-dimensional ducts

Acoustic propagation through a lined two-dimensional duct is examined in order to assess the influence of the shape of the mean-velocity profile on the attenuation rate. Five mean-velocity profiles are considered: linear, parabolic, Pohlhausen, 1/7th power law with a linear sub-layer, and linear with slip at the wall. It is shown that when the attenuation rate is tabulated as a function of the boundary-layer thickness, as is usually done, substantially different results are obtained from the several mean profiles. However, when the displacement thickness is used, a considerable collapse is achieved in the attenuation curves that are obtained from the various profiles. For downstream propagation, all profiles produce essentially the same results over a reasonable range of boundary-layer thickness. However, for many cases of upstream propagation, the results from the 'turbulent' boundary-layer profiles differ significantly from the results of the other profiles even when compared on the basis of displacement thickness.

Hayfeh, A. H.↗
NASA NTRS1974

The broadening of He I lines including ion dynamic corrections, with application to 4471 A

A theory of the broadening of He I lines with forbidden components is developed. The theory takes into account the effects of dynamic ion broadening and is valid at low densities where the forbidden line is reasonably well isolated. Good agreement with experiment and with calculations by Lee (1972) was obtained when the theory was applied at a wavelength of 4471 A. Tables of these data are given and are extended into the line wings beyond the extent of previous tabulations. Reasons for agreement with Lee data are discussed in detail. The density level above which the static ion theory is adequate is defined. A simple numerical profile of allowed lines is also obtained, taking into account dynamic ion effects.

Barnard, A. J.↗
NASA NTRS1972

Very Long Baseline Interferometry (VLBI) earth physics

The characteristics of the Michelson/Pease stellar interferometer are discussed. An analog of the interferometer using radio waves is described. The use of a conventional hard-wired interferometer with very long base line interferometry (VLBI) is analyzed. Mathematical models are developed to analyze the VLBI techniques. A summary of VLBI geodetic experiments is tabulated. The concept and application of the astronomical radio interferometric earth surveys (ARIES) are reported. A schematic diagram of ARIES implementation is provided.

Macdoran, P. F.↗
NASA NTRS1972

Timing requirements for the Sanguine ELF communications system

The development of an extremely low frequency (ELF) communications system for command and control of naval forces is discussed. The basic requirements for the system are defined. Emphasis is placed on the clock requirements based on phase or time rather than frequency. The time and frequency requirements at the transmitter stations are tabulated.

Kruger, B.↗
NASA NTRS1974

The Final Skylab Mission: Man at Home and at Work in Space

The accomplishments of the Skylab 4 mission are discussed. The medical experiments and dietary aspects of the mission are reported. The observation of the Comet Kohoutek is described. The remote sensing of earth resources is examined to show the areas of coverage. The repair of the space station and the accomplishment of unscheduled requirements are discussed. Statistical data of all the Skylab missions are tabulated.

Source record↗
NASA NTRS1974

Results of investigations on an 0.015-scale 140A/B configuration of the Rockwell International space shuttle orbiter (model 49-O) in the NASA/Ames Research Center 3.5-foot hypersonic wind tunnel (OA36)

The results of wind tunnel tests of the 140A/B configuration components are reported for the fuselage, canopy, elevons, bodyflaps, pods, engine nozzles, rudder, vertical tail, and wing. The test facility, and data reduction procedures are described. Test results for each component are graphed, and tabulated source data are included.

Milam, M. D.↗
NASA NTRS1973

Water penetration study

Nine film-filter combinations have been tested for effectiveness in recording water subsurface detail when exposed from an aerial platform over a typical water body. An experimental 2-layer positive color film, a 2-layer (minus blue layer) film, a normal 3-layer color film, a panchromatic black-and-white film, and an infrared film with selected filters were tested. Results have been tabulated to show the relative capability of each film-filter combination for: (1) image contrast in shallow water (0 to 5 feet); (2) image contrast at medium depth (5 to 10 feet); (3) image contrast in deep water (10 feet plus); (4) water penetration; maximum depth where detail was discriminated; (5) image color (the spectral range of the image); (6) vegetation visible above a water background; (7) specular reflections visible from the water surface; and (8) visual compatibility; ease of discriminating image detail. Recommendations for future recording over water bodies are included.

Lockwood, H. E.↗