Study of LANDSAT-D thematic mapper performance as applied to hydrocarbon exploration

Improved delineation of known oil and gas fields in southern Ontario and a spectacularly high amount of structural information on the Owl Creek, Wyoming scene were obtained from analysis of TM data. The use of hue, saturation, and value image processing techniques on a Death Valley, California scene permitted direct comparison of TM processed imagery with existing 1:250,000 scale geological maps of the area and revealed small outcrops of Tertiary volcanic material overlying Paleozoic sections. Analysis of TM data over Lawton, Oklahoma suggests that the reducing chemical environment associated with hydrocarbon seepage change ferric iron to soluble ferrous iron, allowing it to be leached. Results of the band selection algorithm show a suprising consistency, with the 1,4,5 combination selected as optimal in most cases

A comparison of fatigue life prediction methodologies for rotorcraft

Because of the current U.S. Army requirement that all new rotorcraft be designed to a 'six nines' reliability on fatigue life, this study was undertaken to assess the accuracy of the current safe life philosophy using the nominal stress Palmgrem-Miner linear cumulative damage rule to predict the fatigue life of rotorcraft dynamic components. It has been shown that this methodology can predict fatigue lives that differ from test lives by more than two orders of magnitude. A further objective of this work was to compare the accuracy of this methodology to another safe life method called the local strain approach as well as to a method which predicts fatigue life based solely on crack growth data. Spectrum fatigue tests were run on notched (k(sub t) = 3.2) specimens made of 4340 steel using the Felix/28 tests fairly well, being slightly on the unconservative side of the test data. The crack growth method, which is based on 'small crack' crack growth data and a crack-closure model, also predicted the fatigue lives very well with the predicted lives being slightly longer that the mean test lives but within the experimental scatter band. The crack growth model was also able to predict the change in test lives produced by the rainflow reconstructed spectra

Development of a prototype plastic space erectable satellite Quarterly report, Sep. - Nov. 1965

Test program for cap section mesh fabrication in prototype space erectable satellite developmen

Satellite lifetime routine user's manual

A FORTRAN coded computer program which determines secular variations in mean orbital elements of earth satellites and the lifetime of the orbit is described. The dynamical model treats a point mass satellite subject to solar and lunar disturbing gravitational fields, second, third and fourth harmonics of the earth's oblate potential, earth's atmospheric drag, and solar radiation pressure. Each of these disturbing functions may be selectively simulated. Data preparation instructions, a sample problem, and definitions of output quantities are included

The Pennyland Project

This is the final report on the performance of 177 low-energy houses at Pennyland, Milton Keynes, monitored by the Open University Energy Research Group (ERG), for the Milton Keynes Development Corporation (MKDC), under contract to the Energy Technology Support Unit (ETSU) at Harwell.[The smaller file contains the Executive Summary; the larger file contains the main report, excluding the Executive Summary]

Constraints on Kaluza-Klein gravity from Gravity Probe B

Using measurements of geodetic precession from Gravity Probe B, we constrain possible departures from Einstein's General Relativity for a spinning test body in Kaluza-Klein gravity with one additional space dimension. We consider the two known static and spherically symmetric solutions of the 5D field equations (the soliton and canonical metrics) and obtain new limits on the free parameters associated with each. The theory is consistent with observation but must be "close to 4D" in both cases.Comment: 9 pages, 1 figure; General Relativity and Gravitation, in pres

Observational Evidence for a Multiphase Outflow in QSO FIRST J1044+3656

Spectral absorption features in active galactic nuclei (AGNs) have traditionally been attributed to outflowing photoionized gas located at a distance of order a parsec from the central continuum source. However, recent observations of QSO FIRST J104459.6+365605 by de Kool and coworkers, when intepreted in the context of a single-phase gas model, imply that the absorption occurs much farther (approx 700 pc) from the center. We reinterpret these observations in terms of a shielded, multiphase gas, which we represent as a continuous low-density wind with embedded high-density clouds. Our model satisfies all the observational constraints with an absorbing gas that extends only out to about 4 pc from the central source. The different density components in this model coexist in the same region of space and have similar velocities, which makes it possible to account for the detection in this source of absorption features that correspond to different ionization parameters but have a similar velocity structure. This model also implies that only a small fraction of the gas along the line of sight to the center is outflowing at the observed speeds and that the clouds are dusty whereas the uniform gas component is dust free. We suggest that a similar picture may apply to other sources and discuss additional possible clues to the existence of multiphase outflows in AGNs.Comment: 6 pages, 2 figures, Accepted for publication in ApJ v569 n2, April 20, 200

Evaluation of the suitability of Skylab data for the purpose of petroleum exploration

There are no author-identified significant results in this report

The Hazy Future: Are State Attempts to Reduce Visibility Impairment in Class I Areas Caught between Scylla and Charybdis? The Effects of the Clean Air Act Amendments of 1990 on Visibility Protection

In recent decades, the visibility in America\u27s national parks and other class I areas has declined significantly as a result of manmade air pollution. This Comment provides a comprehensive history of visibility regulations in the United States. It also briefly describes the sources and types of visibility impairment in class I areas and the regulatory and statutory framework enacted to address them. The author examines the various lawsuits brought by northeastern states to force the EPA to promulgate stricter visibility regulations for class I areas. Unfortunately, these suits failed to remedy visibility impairment. The author also describes the different arguments and provisions of the Clean Air Act used in these lawsuits and the reasons for their failures. The author opines that the failure of these suits has placed northeastern states between Scylla and Charybdis (the continued impairment of visibility in class I areas and no legal remedy for the problem). To help northeastern states escape this predicament, this Comment suggests possible arguments and legal solutions which can be used in the future to resolve the states\u27 visibility problems. Finally, this Comment describes and analyzes the 1990 Amendments to the Clean Air Act and their effects on the future protection of visibility in class I areas