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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 145 records · Page 8

The linear polarization of lunar thermal emission at 3.1 mm wavelength

Several observations of the distribution of linearly polarized lunar thermal emission were made at a wavelength of 3.1 mm with 4.88 m parabolic reflector from February to March 1971. A shadow corrected rough surface thermal emission model was least squares fitted to the data. Results indicate an effective lunar dielectric constant of 1.34 + or -.08 with surface roughness characterized by a standard deviation of surface slopes of 18 deg + or - 2 deg. A comparison of these results with previously published values at other wavelengths suggests that the effective lunar dielectric constant decreases with decreasing wavelength.

White, T. L.↗

Atmospheric absorption measurements in the region of 1 mm wavelength.

A Froome-type plasma-metal-junction device (1962) was used in high-resolution radiation transmission measurements in the atmosphere at wavelengths from 0.5 to 3.0 mm. The experimental and theoretical results for water vapor absorption lines in two submillimeter wavelength windows were compared, showing that this technique provided a much higher wavelength accuracy than more conventional optical-type spectroscopy.

Emery, R.↗

Observations of the total lunar eclipse on February 10, 1971 at 3.1 mm wavelength.

Observations were made of the total lunar eclipse on February 10, 1971 at a wavelength of 3.1 mm at the Millimeter Wave Observatory of the University of Texas at Austin. Eclipse cooling curves obtained for Copernicus, Mare Serenitatis, and a mountainous region indicate maximum temperature decreases of 6.77%, 6.37%, and 7.51%, respectively. Cooling rates of about 6 K/hour were measured. The normalized solar insolation has also been calculated for each region.

Ulich, B. L.↗

Parametric study of the lubrication of thrust loaded 120-mm bore ball bearings to 3 million DN

A parametric study was performed with 120-mm bore angular-contact ball bearings under varying thrust loads, bearing and lubricant temperatures, and cooling and lubricant flow rates. Contact angles were nominally 20 and 24 deg with bearing speeds to 3 million DN. Endurance tests were run at 3 million DN and a temperature of 492 K (425 F) with 10 bearings having a nominal 24 deg contact angle at a thrust load of 22241 N (5000 lb). Bearing operating temperature, differences in temperatures between the inner and outer races, and bearing power consumption can be tuned to any desirable operating requirement by varying 4 parameters. These parameters are outer-race cooling, inner-race cooling, lubricant flow to the inner race, and oil inlet temperature. Preliminary endurance tests at 3 million DN and 492 K (425 F) indicate that long term bearing operation can be achieved with a high degree of reliability.

Signer, H.↗

Wind tunnel investigation of aerodynamic characteristics of a scale model of a D5 bulldozer and an M109 self-propelled 155 mm Howitzer

Wind tunnel tests were conducted on a scale model of a D5 bulldozer and an M109 self-propelled 155 MM howitzer to determine the aerodynamic characteristics of these typical externally-suspended heavy lift helicopter cargo configurations. Tests were made over a large range of pitch and yaw attitudes at a nominal Reynolds number per unit length of 1.5 x 10 to the 6th power.

Laub, G. H.↗

Lunar polarization studies at 3.1 mm wavelength

Observations of the distribution of linearly polarized lunar thermal emission were made at a wavelength of 3.1 mm with The University of Texas 4.88 m parabolic reflector (0.042 deg HPBW). A shadow corrected, rough surface, thermal emission model for a homogeneous moon was least-squares-fitted to the polarization data. Results indicate an effective lunar dielectric constant of 1.34 plus or minus 0.04 with surface roughness characterized by a standard deviation of 17 (plus or minus 5) deg for surface slopes with a normal probability density, independent of lunar phase. A comparison of these results with published values at other wavelengths suggests that the effective lunar dielectric constant, as obtained by lunar emission measurements, decreases with decreasing wavelength of observation. This wavelength dependence may be interpreted in terms of an inhomogeneous surface and/or a surface that possesses intermediate scale surface roughness.

White, T. L.↗

Early lunar history - Ages of 2 to 4 mm soil fragments from the lunar highlands

The ages of twenty-one 2 to 4 mm soil fragments from Apollo 16 stations 6, 8, 11, and 13, including all six major petrographic rock types found among Apollo 16 samples, were determined using the Ar-40/Ar-39 stepwise-heating technique. Twelve of the twenty-one samples have ages within 3.95 to 4.06 billion years, and it is believed that they represent the age of at least one stage of the Cayley Formation. Four samples have ages distinctly older than 4.00 billion years, making them the oldest lunar material found to date.

Schaeffer, O. A.↗

Observations and analysis of lunar radio emission at 3.09 mm wavelength

An analysis of data on lunar radio emission at 3.09 mm wavelength is presented. The data were obtained during a single lunation in a manner that facilitates their comparison with a calculated model. Specific regions of the moon (Copernicus, Sea of Serenity, Sea of Tranquillity, Ocean of Storms, and an highland region near the mean center) were studied with enough angular resolution to distinguish between different types of terrain. The data were absolutely calibrated and yield a new measurement of the lunation average brightness temperature of the center of the moon.

Ulich, B. L.↗

Petrology of the highlands massifs at Taurus-Littrow - An analysis of the 2-4 mm soil fraction

The petrography, phase chemistry, and Ar-40/Ar-39 ages of 2-4 mm fragments from the soils of both mare and highlands stations sampled by Apollo 17 are studied. It is found that the massifs consist of a complex stratigraphy of interlayered noritic breccias of varying metamorphic grades, melt rocks, and anorthositic rocks. A stratigraphic correlation of the lithologies within the North Massif and the South Massif is carried out. The petrogenesis of rock types with respect to thermal and impact history is discussed. The observed spinel cataclasites may represent relatively deep material sampled by the Serenitatis event.

Bence, A. E.↗

Apollo 16: Core 60004 - Preliminary study of less than 1 mm fines

The article studies the possible variation of mineralogy as a function of both grain size and depth within the core of less than 1 mm fines, for the core section 60004 from Apollo 16. Twelve samples of the fines were dry sieved. The grain size analysis showed a bimodal distribution for all samples, indicating a competing process of grain size degeneration and agglutinate formation. Approximately 99% of the minerals in the samples examined consisted of plagioclase feldspar, pyroxene and olivine, with plagioclase the dominant phase. The various minerals were analyzed, using standard electron microprobe techniques, as a function of size range for each sample, and the representative analyses are presented. Several types of glass were also analyzed, ranging in color from orange through yellow and green to colorless. The investigation of the chemical variations of mineral and lithic clasts from the top and the bottom of the core suggests that although minor variations are present, the regolith was derived from fairly homogeneous sources.

Meyer, H. O. A.↗

Apollo 17 1-2 mm fines - Mineralogy and petrology

Nine 1-2 mm Apollo 17 soil samples from the South Massif and the Sculptured Hills are examined using petrographic and microprobe techniques. Each soil was separated into six groupings based on macroscopic features observed under a stereomicroscope. The groups and their characteristics are described. Minor differences observed include a higher content of fine-grained, dark, friable breccia and a higher content of high-Mg mafic-bearing fragments in the Sculptured Hills soils. The olivine and pyroxene compositions for light breccia from the soil samples are summarized. During the soil examination, several distinctive fragments seen include coarse orthopyroxene-plagioclase fragments with diopside-rich veins, a plagioclase-forsterite fragment with an igneous texture and a pyroxene-plagioclase fragment with isotropic, subhedral plagioclase grains.

Steele, I. M.↗

The use of hand-held 35 mm color infrared imagery for estimates of suspended solids - A progress report

A cost-effective aerial surveillance technique is proposed for detection and identification of suspended solids which would be operational for both governmental monitoring organizations and private individuals operating catfish farms. Sixteen catfish ponds were flown daily for seven days using two hand-held 35 mm cameras with both Kodachrome X and Ektachrome infrared film. Hue, value, and chroma designations were recorded for each pond on each date by three interpreters, and the accepted color was that recorded by at least two of the interpreters, or if there was a three hue range, the median was accepted. Relations between suspended solids and color designations were analyzed graphically, and chroma was discarded due to an apparent lack of correlation. The data obtained were then analyzed by multiple regression. Significant correlations were revealed between hue and value and total and inorganic suspended solids. If perfected, this technique could be developed to sufficent accuracy for large-scale reconnaissance surveys to monitor the quality of rivers and streams.

Miller, W. F.↗

Microwave line transitions in the 3-mm wavelength range in comet Kohoutek /1973f/

A search program for microwave line transitions in comet Kohoutek is reviewed. Observations in the 3-mm wavelength region were carried out before perihelion from December 15 to 20, 1973, and after perihelion from January 3 to 7, 1974. During these times, the comet was between 0.3 and 0.5 AU from the sun. Gas production rates of HCN are several times 10 to the 27th power to about 10 to the 28th power molecules/sec at approximately 0.4 AU. Upper limits for CH3CN and several other molecules are given.

Huebner, W. F.↗

Apollo 15 coarse fines (4-10 mm): Sample classification, description and inventory

A particle by particle binocular microscopic examination of all of the Apollo 15 4-10 mm fines samples is reported. These particles are classified according to their macroscopic lithologic features in order to provide a basis for sample allocations and future study. The relatively large size of these particles renders them too vaulable to permit treatment along with the other bulk fines, yet they are too small (and numerous) to practically receive full individual descriptive treatment as given the larger rock samples. This examination, classification and description of subgroups represents a compromise treatment. In most cases and for many types of investigation the individual particles should be large enough to permit the application of more than one type of analysis.

Powell, B. N.↗