5,636 research outputs found
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Report of Investigations No. 131 Origin and Diagenesis of Cap Rock, Gyp Hill and Oakwood Salt Domes, Texas
UT Librarie
Radiation induced zero-resistance states: a dressed electronic structure effect
Recent results on magnetoresistance in a two dimensional electron gas under
crossed magnetic and microwave fields show a new class of oscillations,
suggesting a new kind of zero-resistance states. A complete understanding of
the effect is still lacking. We consider the problem from the point of view of
the electronic structure dressed by photons due to a in plane linearly
polarized ac field. The dramatic changes in the dressed electronic structure
lead to a interpretation of the new magnetoresistance oscillations as a
persistent-current like effect, induced by the radiation field.Comment: 5 pages, 5 figures, revtex4, changes in introduction and added
reference
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Report of Investigations No. 123 Petroleum Potential of the Palo Duro Basin, Texas Panhandle
UT Librarie
The Evolution of Post-Starburst Galaxies from to the Present
Post-starburst galaxies are in the transitional stage between blue,
star-forming galaxies and red, quiescent galaxies, and therefore hold important
clues for our understanding of galaxy evolution. In this paper, we
systematically searched for and identified a large sample of post-starburst
galaxies from the spectroscopic dataset of the Sloan Digital Sky Survey (SDSS)
Data Release 9. In total, we found more than 6000 objects with redshifts
between and , making this the largest sample of
post-starburst galaxies in the literature. We calculated the luminosity
function of the post-starburst galaxies using two uniformly selected
subsamples: the SDSS Main Galaxy Sample and the Baryon Oscillation
Spectroscopic Survey CMASS Sample. The luminosity functions are reasonably fit
by half-Gaussian functions. The peak magnitudes shift as a function of redshift
from at to at . This is
consistent with the downsizing trend, whereby more massive galaxies form
earlier than low-mass galaxies. We compared the mass of the post-starburst
stellar population found in our sample to the decline of the global
star-formation rate and found that only a small amount () of all
star-formation quenching in the redshift range results in
post-starburst galaxies in the luminosity range our sample is sensitive to.
Therefore, luminous post-starburst galaxies are not the place where most of the
decline in star-formation rate of the universe is happening.Comment: 26 pages, 24 figures, 8 tables. Accepted for publication in The
Astrophysical Journa
Social Work Practice with West Indian Immigrant Families
The University Archives has determined that this item is of continuing value to OSU's history.Presenter: Shirley P. Thrasher, D.S.W., A.C.S.W., Assistant Professor, Wayne State University, School of Social Work, Detroit, Michigan - "Social Work Practice with West Indian Immigrant Families".The Ohio State University College of Social Wor
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State Lands Energy Resource Optimization Project
Project SLERO, for which The University of Texas at Austin Bureau of Economic Geology was the lead contractor and coordinating institution, was a five-university consortium study of hydrocarbon resources on Texas State Lands. The five universities are The University of Texas at Austin, Texas A&M University, the University of Houston, Texas Tech University, and Lamar University, and the entire program was aided by the cooperation of the Texas General Land Office. This 4-year project was funded through the Office of the Governor of Texas. Project personnel included geologists, petroleum engineers, geophysicists, and chemists. The interdisciplinary nature of this project was directed toward a more thorough understanding of the geologic controls on production and the development of appropriate recovery technologies to address the specific needs of State Lands reservoirs. Transfer of these technologies to industry, in particular to independent operators, is expected to result in increased efficiency of hydrocarbon recovery from State Lands and increased revenue to the Texas Public School Fund. The project was divided into three parts: (1) play analysis and resource assessment, (2) reservoir characterization, and (3) development of advanced extraction technology.Bureau of Economic Geolog
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Petrography and Diagenesis of the Travis Peak (Hosston) Formation, East Texas
Petrographic studies of the Travis Peak Formation in East Texas were used to interpret the diagenetic history of Travis Peak sandstones and to relate the diagenetic history to permeability variations within the formation.
Travis Peak sandstones are fine to very fine-grained quartzarenites and subarkoses that were derived from sedimentary, metamorphic, and igneous rocks exposed in a large area of the southwestern United States. The originally high depositional porosity in matrix-free sandstones was reduced by compaction and precipitation of authigenic cements, particularly quartz, ankerite, illite, and chlorite. In addition, reservoir bitumen, a high molecular weight hydrocarbon residue, occludes porosity in some zones near the top of the Travis Peak. Porosity and permeability have a wide range of values at the top of the formation, but both the range of values and the maximum values decrease with depth below the top of the Travis Peak. Dissolution of orthoclase and plagioclase has formed most of the secondary porosity. Porosimeter-measured porosity is the best predictor of permeability, and there is a significant inverse correlation between the total volume of cement and permeability.Bureau of Economic Geolog
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Play Analysis and Digital Portfoilio of Major Oil Reservoirs in the Permian Basin
This 2-year PUMP project, now well underway, has made significant progress toward all goals and objectives. This report describes the work accomplished on the project during the first year.
The target of the project is the Permian Basin of West Texas and southeast New Mexico (fig. 1), the largest petroleum-producing basin in the United States. The Permian Basin produced 18 percent of the total U.S. oil production in 1999, and it contains an estimated 23 percent of the proved oil reserves in the United States (EIA, 2000). Moreover, this region has the biggest potential for additional oil production in the country, containing 29 percent of estimated future oil reserve growth (Root and others, 1995). More than in any other region, increased use of preferred management practices in Permian Basin oil fields will have a substantial impact on domestic production.
Production in the Permian Basin occurs from Paleozoic reservoirs, from Ordovician through Permian (fig. 2). Original oil in place (OOIP) in the Texas part of the basin alone was about 106 billion barrels (Bbbl) of oil (EIA, 2000). After reaching a peak production of more than 665 million barrels (MMbbl) per year in the early 1970s, Permian Basin oil production has continuously fallen. By 1999, production had fallen to less than 300 MMbbl, or half its peak production. Despite the continuing fall in production, the Permian Basin still holds a significant volume of oil. Although about 30 Bbbl of oil has been produced to date, this production represents only about 28 percent of the OOIP. Of the huge remaining resource in the basin, as much as 30 Bbbl of mobile oil remains as a target for improved technology and recovery strategies (Tyler and Banta, 1989).Bureau of Economic Geolog
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