Analyses of shells of revolution by finite elements
Stress analysis methods for rotational thin walled shells and domes by means of finite element procedure
Popov, E. P.↗
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Hydraulic expansion process shapes large metal sheets
Process imparts dome shape to titanium sheets and is applicable to shaping other metals. Method is of interest to automobile and aircraft body manufacturers.
Anderson, E.↗
Advanced structural geometry studies. Part 1: Polyhedral subdivision concepts for structural applications
Development of polyhedral subdivision concepts and application to structural analysis of spheres, hemispheres, and domes - Part 1
Clinton, J. D.↗
Plastic buckling of point-loaded spherical shells
Thin spherical roller supported domes stability and axisymmetric deformation under apex point loads, investigating plastic buckling and inelastic strain effects
Roberts, S. B.↗
Effects of inhalation of Freon 113 on laboratory animals
Four monkeys, 8 dogs, 40 mice, and 50 rats were exposed continuously to 2000 ppm Freon 113 in a Thomas Dome for 14 days. This exposure produced no mortalities nor adverse symptomology. There were no significant alterations in hematological values, clinical chemistries, electroencephalographic findings, body weights, or organ to body weight ratios. The effect of 2% Freon 113 on nicotinic transmission through the stellate ganglion of the spinal dog was also evaluated. The exposure induced a reduction in nicotinic transmission comparable to 2% halothane.
Carter, V. L.↗
Evidence for vulcanism on the moon.
Discussion of various kinds of lunar features generally agreed to be of entirely volcanic origin. Possible mechanisms of formation of lunar domes, crater chains (especially those that lie along a rill), craters surrounded by dark halos, sinuous rills, mare ?wrinkle' ridges, dark smooth level material, and ring dike-like structures through volcanic activity are suggested. The examples considered are believed to provide strong evidence and implications that considerable volcanism has occurred on the moon, has played a large part in modifying and shaping the visible surface features, and may still be mildly active at present.
Cameron, W. S.↗
Lava tubes and channels in the Lunar Marius Hills.
The Marius Hills region, a volcanic plateau in Oceanus Procellarum, contains numerous rilles, rille-like structures, and chains of elongate craters. Most of these structures characteristically: (1) originate on or near irregular shaped craters associated with features previously interpreted as volcanic domes, (2) trend downslope onto Plateau Plains, (3) generally taper in width and become shallower, (4) are often discontinuous, (5) occupy the center, or apparent crest of a broad ridge, (6) may contain cut-off branches and distributary structures, and (7) may have local reversals in longitudinal slope. Structures having these characteristics are interpreted to be lava channels or partly collapsed lava tubes. Terrestrial lava tubes form exclusively, and commonly, in fluid basalt flows. Recent evidence indicates that viscosities of lunar mare 'basalt' lava flows were conducive for lava tube formation. Terrestrial analogs are offered for structures described in the Marius Hills.
Greeley, R.↗
Development of boron epoxy rocket motor chambers.
A 71 cm diameter 74 cm length boron/epoxy composite rocket motor chamber was designed based on the geometric configuration of the JPL Applications Technology Satellite titanium alloy apogee motor chamber. Because analyses showed large stress concentrations in the domes, the configuration was modified using the same basic constraints for openings and attachments. The rocket motor chamber was then fabricated by filament winding with boron/epoxy tape and hydrostatically tested to failure at 264 N/sq cm, 57.2 N/sq cm above the design value. Two more rocket motor chambers were fabricated with the same basic constraints, but shortened to 57.6 cm for a smaller propellant load. The first of these short chambers failed in proof because of filament winding fabrication difficulties. The second chamber was successfully fabricated and passed the hydrostatic proof test.
Jensen, W. M.↗
Observations of fast auroral waves.
Results of simultaneous observation of a fast wave event from the Ester Dome Observatory (EDO) near College, Alaska, the Poker Flat Rocket Launching Facility (PKR), and Fort Yukon, Alaska (FYU). The display occurred on Mar. 27, 1971, and the general morphology is described and discussed. It is suggested that fast auroral waves occur when a preceding substorm has enhanced the particle population in the region of the magnetosphere near L = 6 in the midnight sector; then transverse hydromagnetic waves, associated with the onset of further local substorm activity, become visible through their action on this enhanced particle population as they propagate inwards in the equatorial region.
Boyd, J. S.↗
High resolution spectroscopy of the disk chromosphere. II - Time sequence observations of Ca II H and K emissions.
Two independent sets of high resolution time series spectra of the Ca II H and K emission obtained at the Solar Tower and at the Big Dome of the Sacramento Peak Observatory on September 11th, 1971 are reported. The evolutionary behavior of the emission first reported by Wilson and Evans is confirmed, but the detail of the evolution is found to be more complex. In one case, a doubly peaked feature showing some K3 emission evolves into a single K2 (red) peak with no K3 emission. Coincidentally, a neighboring doubly peaked feature evolves to a very strong blue peak. In an entirely independent sequence a doubly peaked feature evolves into a single red peak. The K2 emission then fades completely although the continuum threads are still strong. Finally a strong K2 blue peak appears. It is concluded that the observed evolution of the K2 emission is due to temporal variations in the physical conditions which give rise to them.
Wilson, P. R.↗
To evaluate ERTS-1 data for usefulness as a geological sensor in the diverse geological terranes of New York State
The author has identified the following significant results. In the present imagery, obtained during the full foliage of summer and fall, the greatest amount of spectral geology is displayed in the Adirondack region where bedrock geology is strongly linked to topography. Of the four spectral bands imaged, band 5 and 7 provide the most geological information. The boundary between the basement rocks of the Adirondack Dome and the surrounding Lower Paleozoic rocks is well delineated except in the Northwest Lowlands and along parts of the eastern Adirondacks. Within the basement complex, the most prominently displayed features are numerous north-northeast trending faults and topographic lineaments, and arcuate east-west valleys developed in some of the weaker metasedimentary rocks. The majority of the faults and lineaments shown on the geologic map of New York appear in the ERTS-1 imagery. In addition, many new linears were detected, as well as a number of anomalous curvilinear elements, some circular in plan and measuring up to 25 km in diameter, which do not bear any clear relationship to mapped geological contacts. The possibility that it is an astrobleme will be investigated after snow melts in the spring.
Isachsen, Y. W.↗
Investigation of the detection and monitoring of forest insect infestations in the Sierra Nevada Mountains of California
The author has identified the following significant results. The detection of insect infestations through the use of ERTS-1 imagery alone is very promising. In the field of features other than insect infestation, it is possible to detect: timber vs. non-timber; timber density in broad categories; lakes, major stream courses, rock outcrops and domes; riparian vegetation, cultivated fields, pasture land, and glaciers.
Hall, R. C.↗
Investigation of the detection and monitoring of forest insect infestation in the Sierra Nevada Mountains of California
The author has identified the following significant results. Significant progress has been made in detecting insect outbreaks from ERTS-1 data during this period. It is possible to differentiate forested areas with heavy damage from those with little or no damage. The analysis is made with color infrared positive transparencies and prints. Enlargement of the transparencies makes it possible to detect and map areas of three degrees of tree mortality into heavy, medium, and light. It was also noted that shadows cast by massive rock domes closely resemble natural lakes.
Hall, R. C.↗
Identification, definition and mapping of terrestrial ecosystems in interior Alaska
The author has identified the following significant results. A transect of the Tanana River Flats to Murphy Dome, Alaska was accomplished. The transect includes an experimental forest and information on the range of vegetation-land form types. Multispectral black and white prints of the Eagle Summit Research Area, Alaska, were studied in conjunction with aerial photography and field notes to determine the characteristics of the vegetation. Black and white MSS prints were compared with aerial photographs of the village of Wiseman, Alaska. No positive identifications could be made without reference to aerial photographs or ground truth data. Color coded density slice scenes of the Eagle Summit Research Area were produced from black and white NASA aerial photographs. Infestations of the spruce beetle in the Cook Inlet, Alaska, were studied using aerial photographs.
Anderson, J. H.↗
To evaluate ERTS-1 data for the usefulness as a geological sensor in the diverse geological terranes of New York State
The author has identified the following significant results. The straight NNE-trending escarpment that marks the easternmost extent of the Catskill Mountains appears, from ERTS-1 imagery (1079-15124) to be related to a set of parallel topographic lineaments which occur over a distance of 40 km to the west. The October 11 imagery of the Adirondacks (1080-15174) displays the pre-Paleozoic erosion surface along the western and northern margin of the Adirondack Mountains dome. The northern portion of this paleoplain is terminated to the southeast by an escarpment following an ENE topographic linear to produce a pseudo-cuesta. The snow covered terrain in the Mohawk Valley between Albany and Rome (1170-15182 and 1169-15123) displays with sculptural clarity a drumlin field having a cloud-free area of about 2600 sq km; glacial flow directions can be plotted readily because the stoss and lee sides of the drumlins can be distinguished. In the imagery of summer and fall, agricultural patterns obscured the detail which is visible in the winter imagery.
Isachsen, Y. W.↗
The hydroxyl emissions in relation to the dynamical processes of the atmosphere
Ground and airborne hydroxyl emission observations were made in the northern polar regions. The ground observations were made at Ester Dome, Alaska, and the airborne observations were made during the 1969 NASA Airborne Expedition. The analysis of some of the data that were acquired has lead to the following conclusions: (1) Airglow OH measurements show no appreciable change with latitude or longitude. (2) Diurnal changes at northern latitudes are similar to those observed in midlatitude regions. (3) Two types of OH enhancements were observed photometrically in the 9370 A region - one associated with visible aurora, and the other uncorrelated with visible aurora. High resolution spectra under both inactive and active conditions indicate that the OH enhancements seen photometrically in active aurorae are probably due to contamination of the filter pass bands by the unexpected enhancement of the NI multiplet lines at 9387 A and 9393 A. All previously reported aurorally associated enhancements are consequently suspect.
Romick, G. J.↗
Investigation of the detection and monitoring of forest insect infestation in the Sierra Nevada Mountains of California
The author has identified the following significant results. Results of analysis of ERTS-1 color composites made by NASA from MSS bands 4, 5, and 7, frame #1055-18055 at a scale of 1:1,000,000 indicate that forests damaged by insects can be delineated and mapped from areas with no damage; and at this same scale other details detected include timbered and nontimbered areas, pasture and agricultural land, deserts, lakes, mountain meadows, riparian vegetation, rock domes, old burned areas, and major stream courses. Enlargements from the above to a scale of 1:80,000 have improved detectibility to the point that three degrees of timber mortality can be identified and mapped.
Hall, R. C.↗
Utilizing ERTS-A imagery for tectonic analysis through study of Big Horn Mountains region
The author has identified the following significant results. Winter imagery in December 6-10, 1972 and January 11-13, 1972, provides optimum snow cover and depth such that, along with low sun angle, topography and drainage are markedly enhanced. Several features are visible that are poorly, or even not distinguishable on clear scenes without snow. Examples are Bear Butte (igneous plug) and Elkhorn Peak (dome) on scene (1136-17130), northeastern Black Hills, (1172-17130) a linear linking the Cascade anticline and Cretaceous hogbacks near Hot Springs, S. D. south to the Niobrara River, and (1140-17373) the Lake Basin fault zone north of Billings, Montana. Extremely heavy snows in April completely blot out all vegetation and topography in the Bighorn, Wind River, and Beartooth ranges.
Hoppin, R. A.↗