196,339 research outputs found
Are the mantle lithosphere and lower crust preferentially thinned during continental rifting?
No full textElectronic Thesis or DissertationWorldwide, estimates of extension in rift zones vary greatly depending on the method used to calculate the extension. This variability is the result of the discrepancy between different methodologies and may be the result of polyphase faulting, subresolution faulting, and/or depth-dependent extension. Such inconsistency between estimates has been noted in the Woodlark Basin, an active transition zone between continental rifting and seafloor spreading. Previous work in the basin, where seafloor spreading has not initiated, calculated extension by summing fault heaves, calculating subsidence, and determining plate motion from Euler pole kinematics, yielding estimates of 111 km (23) from brittle extension, 115 km (47) from subsidence, and 200 km (40) from Euler pole kinematics (Kington and Goodliffe, 2008). By incorporating polyphase and subresolution faulting into the brittle extension estimate, Kington and Goodliffe (2008) resolved the discrepancy between estimates of extension derived from brittle faulting and subsidence. The third method used to estimate extension, Euler pole kinematics, produced a large discrepancy. Kington and Goodliffe (2008) interpreted this to be the result of preferential extension of the lower crust and mantle lithosphere during the rifting phase and proposed that uniform extension would occur throughout the lithosphere after seafloor spreading initiation. The current study explores potential errors in previous work in the basin and determines if the results are applicable to other portions of the basin. In contrast to Kington and Goodliffe (2008), the current study determines extension where seafloor spreading initiated at ~0.8 Ma. Using the methods and associated errors from Kington and Goodliffe (2008), Euler pole extension estimates (~202 to 238 km) are ~2 times higher than brittle (~69 to 90 km) and subsidence (~60 to 79 km) extension estimates, consistent with the previously seen discrepancy. When taking into account other sources of error not considered by Kington and Goodliffe (2008), the current study shows the previous methods lack the constraints necessary to produce conclusive results. This would also render the results of the previous study by Kington and Goodliffe (2008) inconclusive. Therefore, it is not necessary to invoke the Kington and Goodliffe (2008) model to explain rifting in the western Woodlark Basin
A comparison of continental extension estimates across the margins of the Woodlark Basin, Papua New Guinea
No full textElectronic Thesis or DissertationPrevious studies have shown that depth dependent extension is common across rifted margins. A discrepancy exists between the estimates of extension made through whole lithosphere/crust vs fault heave calculations (for example, northwest Australia, South China Sea, Galicia). Although this discrepancy is also observed in the Woodlark Basin (~111 (23) from brittle extension and ~115 (47) from subsidence [Kington and Goodliffe, 2008]), the location of this study, including sub-seismic resolution and poly-phase faulting reduces this mismatch. What makes the Woodlark Basin unique is that a third measure of continental extension is available, Euler pole kinematics. Previous studies show that this predicts almost double (~220 km) the extension calculated from subsidence and brittle extension [Kington and Goodliffe, 2008]. Extension in the Woodlark Basin began at ~8.4 Ma and transitioned to sea-floor spreading in the east at ~6 Ma [Kington and Goodliffe, 2008]. The basin is an ideal place to study the extension discrepancy because of its young age and thin sediments. Seismic reflection data provide good images of basement and fault structures. High-resolution bathymetry permits tracing of major faults on the seafloor. A previous study focused on the extension discrepancy at the rifting to spreading transition. This study will focus on the discrepancy further east where seafloor spreading began at ~1.8 Ma and opening rates are faster. Using high resolution bathymetry, magnetics, gravity, and low-fold 2-D seismic reflection data allowed me to estimate the amount of extension through brittle extension and subsidence. Euler pole derived extension rates from previous studies were used for comparison. The results of this study show that the amount of extension increases towards the east as is expected from having a Euler pole to the west. Subsidence derived extension estimates yielded 95.6 (38) km at 153.0E with a maximum stretching factor of 1.8. This increased to 145.3 (52) km with a maximum stretching factor of 1.89 to the east. Brittle extension estimates yielded between 107.1 (26.8) and 143.1 (35.8) km of extension between 153.0E and 154.0E. Both estimates of extension are far lower than the ~235 km of extension predicted by Euler Pole kinematics for the same area. As in the Kington and Goodliffe [2008] study, brittle faulting and subsidence derived extension estimates match (within the error limits)
Pc RNAi results in an increase in Su(z)2 levels.
No full text<p>A) We suggest two possible scenarios for the role of Pc in Myc auto-repression: Pc is either directly involved with Myc protein in repression (left), or required to repress a third player, gene Y (right), whose protein product interferes with Myc repression (right). B) A candidate for gene Y. See Goodliffe et al., 2007, for microarray data generation. Log<sub>2</sub> ratios of changes in levels of 19 PcG and TrxG transcripts are shown, compared to wild type levels (Gal4), in embryos with ectopic Myc (blue), ectopic Myc plus Pc RNAi (red) and ectopic Myc plus pho RNAi (green).</p
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
Simulation of thermal plant optimization and hydraulic aspects of thermal distribution loops for large campuses
No full textFollowing an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied
Intern experience at CH���M Hill, Inc.: an internship report
No full textIncludes author's vita"Submitted to the College of Engineering of Texas A&M University in partial
fulfillment of the requirement for the degree of Doctor of Engineering."Includes bibliographical referencesA review of the author's internship experience with CH���M HILL, Inc.
during the period September 1975 through May 1976 is presented. During this nine month
internship the author worked as an Engineer II in the Industrial Processes discipline of this
large consulting engineering firm... The author's prime responsibility was as one of three
lead design engineers on the design of a large wastewater treatment facility for a pulp mill
in Hoquiam, Washington owned by ITT Rayonier Inc. The work generally consisted of the design
of individual treatment units and associated piping and pumping. The purpose of the project
was to provide wastewater treatment capabilities that would satisfy the effluent limitations
(standards) imposed upon the mill by the State of Washington Department of Ecology and the
U.S. Environmental Protection Agency. The author's assignment also entailed necessary
interaction with the project manager and other CH���M HILL design engineers and support staff
members, the client's representatives, and representatives of two other consulting engineering
firms working on the project. Thus, the internship position at CH���M HILL provided considerable
experience coordinating the author's work with the work of other engineers, guiding the design
and administrative efforts of a support staff, and interacting regularly with the client and
other consulting firms. This broad exposure to a variety of engineering and organizational
problems provided a valuable educational experience
Transition to turbulence in a qblique shock-wave/boundary-layer interaction at M=15
No full textDirect numerical simulations are carried out for different forcing techniques to trigger transition during the interaction between an oblique shock-wave and a laminar boundary-layer at M = 1.5. Three forcing methods are used: a) forcing of oblique unstable modes, whose shape and behaviour are determined by the local linear stability theory, b) broadband free-stream acoustic disturbances, and c) a cold plasma flow control device. While the oblique-mode breakdown is dominant for low-amplitude forcing, long streaky structures drive the transition process in a high-amplitude disturbance environment. LES are also performed on the experimental setup by the Institute of Theoretical and Applied Mechanics (ITAM) from Novosibirsk State University with cold plasma actuation. As well as the disturbance type, the effect of Reynolds number and forcing amplitude will be investigated
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