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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

SEDIMENTOLOGY OF THE UPPER MCKENZIE HILL FORMATION (ORDOVICIAN), SLICK HILLS, SOUTHWESTERN OKLAHOMA

Heartsill, Rhett 22 July 2010 (has links)
The McKenzie Hill Formation (Ordovician), third from the base of the Arbuckle Group, was deposited during a Late Cambrian (Franconian) marine transgression across the Laurentian craton. The section examined represents part of a major shallowing upward trend associated with the infill of a linear "gulf" that formed as a phase in the tectonic evolution of the Southern Oklahoma aulacogen. Relatively rapid tectonic subsidence at this time created a depocenter in which over 600 m of carbonates were deposited. The beginning of this phase is marked by emergence and erosion that forms the Fort Sill - Signal Mountain Formation contact. The topmost Fort Sill Formation contains cyanobacterial (algal) boundstones of very shallow water origin; while, the Signal Mountain Formation consists of limestones that record deep water conditions. As the infill continued, limestones show increasingly shallow water facies as they pass upward into the McKenzie Hill Formation. The sections examined in this study show a lower unit that is dominated by thrombolites in complex beds up to two meters in thickness. They were deposited during a time when environmental conditions were conducive for bioherm production with thrombolitic morphologies. The topmost 23 m of the McKenzie Hill Formation, which do not contain thrombolites, are a series of bedded limestones that records a transition from deeper permanent water to more shallow settings characteristic of the Cool Creek Formation. The upper McKenzie Hill Formation contains a variety of chert most likely due to the remobilization of silica from either detrital quartz and/ or siliceous sponges. The entire Signal Mountain - McKenzie Hill - Cool Creek sequence records a shallowing upward trend representing a large-scale (2nd order) cycle, along with small-scale (5th order?) cycles that characterize the outcrops.
132

Boundary Extension in the Auditory Domain

Hutchison, Joanna Lynn 23 July 2007 (has links)
Memory for the boundaries of a scene is often extended outwardthat is, observers remember a scene as containing information that was not directly perceived but that would have logically been present just beyond the observed boundaries of the scene (e.g., Intraub & Richardson, 1989). This bias is referred to as boundary extension. One reason why boundary extension might occur is that it prepares an observer to more efficiently process what might be perceived with the next fixation or in the next moment of time. Studies of boundary extension have used visual and haptic stimuli (e.g., Intraub, 2004), but boundary extension in the auditory domain has not yet been investigated despite evidence that boundary extension is multisensory in nature (Intraub, 2004). Research with representational momentum, a tendency to remember an object as having traveled further than it actually traveled (e.g., Freyd & Finke, 1984), has found biases with auditory stimuli (e.g., Hubbard, 1993). Further, Munger, Owens, & Conway (2005) found boundary extension to occur prior to representational momentum in the visual domain, serving to establish the scene prior to the extrapolation of movement within the scene. It therefore stands to reason that auditory boundary extension exists and precedes any effects of auditory representational momentum. The goal of the present experiments was to determine whether auditory boundary extension exists. Experiments 1-3 used relatively long probes followed by targets of equal or lesser length using either simple or complex stimuli; data in these experiments pointed toward boundary restriction. After noting that boundary restriction occurred at a time delay with wide-angled stimuli in Intraub, Bender, & Mangels (1992) experiments, an examination of close-up, prototypic, and wide-angle auditory stimuli in Experiments 4 and 5 yielded very similar results to that of Intraub et al. (1992)that is, boundary extension occurred for relatively closer (i.e., shorter) targets, and boundary restriction occurred for relatively wider-angle (i.e., longer) targets. Boundary extension only occurred for more continuous (i.e., music) stimuli, but did not occur for more discrete (i.e., literature) stimuli, in line with Freyds (1987) assertion that dynamic mental representations require continuity in time.
133

Transformations of Isocarbostyrils for the Synthesis of Isoquinoline Alkaloids and the Related Analogues

Huang, Yijun 23 July 2008 (has links)
A practical method for the synthesis of an isoquinoline alkaloid 6,7-dimethoxy-2-methylisoquinoline-1,3,4(2H)-trione and its analogues has been demonstrated. Two new methods for synthesizing substituted phthalonimides from the corresponding isocarbostyrils have been developed. Phthalonimide derivatives were obtained by the oxidation of isocarbostyrils protected with methoxymethyl and â,â,â-trichloroethoxymethyl groups. The direct oxidation of isocarbostyrils under different conditions was also investigated. In addition, six dienes for potential use in the development of a [4+2] cycloaddition approach to galanthan tetracyclic ring system have been synthesized. These precursors and dienophiles are based on and drived from isoquinolines and isocarbostyrils.
134

Geomorphic Mapping and Ground-Penetrating Radar Survey of the Agua Blanca Fault in Valle de Santo Tomas, Baja California, Mexico

Cage, William 23 July 2010 (has links)
The Agua Blanca fault is interpreted as an active, dextral strike-slip fault in northern Baja California about 100 km south from the U.S.-Mexico border. Tectonically, the Agua Blanca fault is associated with the San Andreas fault system, which comprises the main portion of the transform plate boundary between the Pacific and North American plates. Although there are estimated slip rates for the fault, there is no recorded seismicity. Geomorphic maps at a scale of ~ 1:5,000 were completed within the Valle Santo Tomas. Features characteristic of strike-slip faulting such as deflected streams and shutter ridges suggest the fault is still active and should not be considered abandoned. Ground-penetrating radar surveys were conducted in order to image the fault in the near surface. Based on the GPR data, it is apparent that a greater number of fault splays exist in the shallow subsurface than evidenced at the surface. This suggests that the detailed structure of the Agua Blanca fault consists of a complex system of fault splays and that a main fault strand and several subsidiary faults splays exist in Valle Santo Tomas.
135

Bismuth Aryloxide Reactivity: Kinetics of Thermal Decomposition and Resulting Organic Oxidation Products

Brien, Kimberly Anne 23 July 2010 (has links)
The Standard Oil of Ohio Company (SOHIO) process is an industrial method for the oxidation and ammoxidation of propene to produce acrolein and acrylonitrile. This process uses a bimetallic catalyst based on Bi2O3*MoO3. Bismuth has been shown to be necessary in the rate determining step as well as in later steps of the catalytic cycle. Our group was the first to describe a molecular bismuth model system with reactivity similar to the SOHIO catalysts using bismuth aryloxides as a model system. This represented the first experimental support that the fundamental step in SOHIO propene activation involves Bi(III)-O bond homolysis to form Bi(II). In an effort to obtain kinetic rates, we chose to study a phenoxy bismuth complex of intermediate steric bulk. We anticipated that 2-tert-butyl-6-isopropylphenol would give a corresponding bismuth aryloxide that would decompose at an intermediate rate. A new synthesis of this phenol was developed. In order to have authentic materials for comparative analysis in the decomposition of the Bi(III) aryloxide Bi(O-2-tBu-6-iPrC6H3)3, four potential decomposition products were synthesized; 2-tert-butyl-6-isopropylquinone, 2-tert-butyl-6-isopropylhydroquinone, 3,3'-di-tert-butyl-5,5'-diisopropyldiphenoquinone, and 3,3'-di-tert-butyl-4,4'-dihydroxy-5,5'-diisopropyldiphenyl. We observed during the isolation of 3,3'-di-tert-butyl-5,5'-diisopropyldiphenoquinone that only the E isomer crystallizes, and slowly equilibrates to a 51:49 E/Z mixture when in solution. We successfully obtained isomerization kinetics that favor a diradical isomerization mechanism. Computational studies in collaboration with the Borden research group at University of North Texas supported our experimental results but giving a smaller negative entropy value. In an effort to obtain the Bi(OAr)3 product by reacting bismuth tert-butoxide with 2-tert-butyl-6-isopropylphenol, we obtained instead tBuOBi(OAr)2. When this bismuth phenoxide was heated in C6D6, decomposition to the corresponding phenol and both E and Z isomers of 3,3'-di-tert-butyl-5,5'-diisopropyldiphenoquinone was observed by 1H NMR. Kinetic studies on this decomposition were initiated and will be discussed. The re-synthesis of a large number of bismuth aryloxides was also performed and their stabilities studied. Kinetic studies of the C-H activation of two bismuth complexes were also initiated. Both experimental and computational studies with the Janesko research group at TCU support a base catalyzed concerted pathway.
136

EXAMINING MEMORY FOR AREA AND DISTANCE: UNTANGLING THE RELATIONSHIP BETWEEN MEMORY PSYCHOPHYSICS AND BOUNDARY EXTENSION.

Courtney, Jon R. 26 July 2006 (has links)
When an observer views a picture of a scene, his or her memory for that scene often includes details that were not present in the scene, but that might have been present just outside the boundaries. This has been referred to as boundary extension (Gottesman & Intraub, 2003; Intraub, 2004; Intraub & Richardson, 1989), and has been proposed to reflect the anticipatory nature of representation (Intraub, 2002). One possible contributing factor to boundary extension is a change in remembered distance (Hubbard, 1996). However, memory psychophysics studies examining memory for distance have found that people most often remember being closer to an object than they were at first sight, which would seem to reflect boundary restriction rather than boundary extension (Algom, 1992). The purpose of the four experiments presented in this dissertation were to find (a) if results such as those found in boundary extension and elsewhere are due to changes in remembered distances of objects, (b) apply theories drawn from boundary extension to ecologically rich stimuli, and (c) resolve inconsistencies between research on boundary extension and memory psychophysics. Experiments 1 and 2 examined memory for distance of close-up 3-D views by asking participants to step forward or backward and adjust themselves to the position in which they first viewed a scene. Results were consistent with memory psychophysics and not boundary extension in that participants generally remembered being closer to the scenes (stepped forward). Experiment 3 used the same 3-D stimuli but used a different distance judgment (verbal rating) and found participants overall showed no change in distance memory. Experiment 4 examined area memory for boundaries of 2-D photographs while area of objects in the photographs were held constant, and found an effect consistent with boundary extension. The data from the four experiments revealed that boundary extension is likely not due to a displacement in depth, and theoretical claims made from studies examining 2-D views might not easily translate to the 3-D world. Implications for theoretical explanations of spatial memory, dissociations between memory for distance and area, and examinations of theories from a standpoint of ecological validity are discussed.
137

The Role of Kappa Opioid Agonist U50,488H in Consummatory Successive Negative Contrast

Wood, Michael David 26 July 2006 (has links)
The role of κ agonist U-50,488H in cSNC was explored in four experiments. Experiment one revealed that U-50 failed to influence cSNC on trial 11 but showed both an attenuation with low dose of U-50 and exaggeration of cSNC in medium and high dose of U-50 by impairing recovery. Experiment two confirmed a selective attenuation for trial 12 of cSNC in groups given low dose, while the medium dose impaired recovery. Experiment three explored the possibility that the effects of U-50 on cSNC may be the result of an influence on alternative mechanisms such as locomotor activity. Results revealed that U-50 showed no influence from saline control. Experiment four explored the effects of U-50 on posttrial 11 and revealed that U-50 signficantly enhanced contrast, on trial 12, indicating an effect on associative mechanisms involved in the memory of the downshift experience.
138

Studies of thermoregulation in small iguanine lizards: feasibility of the use of remote laser sensing equipment to determine deep body temperatures of small lizards and thermoregulatory precision in the field

Bucklin, Stacey Ellen 28 July 2006 (has links)
Many lizards maintain their body temperature within a fairly narrow range, despite spatial and temporal variation in microclimates. The ability to measure these temperatures is central to studying lizard physiology. Non-intrusive methods are preferred because they cause the least disruption to the animals natural behavioral patterns. I modified the Alberts and Grant (1997) model of non-contact temperature prediction of Cuban rock iguanas (mass range 120-850 g) for use on four species of smaller lizards (mass range 2-7 g). I also developed an empirical model expressing the relationship between skin surface temperature (Ts) and internal body temperature (Tb) as a regression. Using this model, and given an ambient temperature (Ta), a lizards internal body temperature can be estimated within 0.2 plus or minus 1.43 SD degrees Celsius from its remotely determined dorsal skin surface temperature. The modified Alberts and Grant model and my model had similar predictive results. Additional potential heating and cooling rates were determined in the lab with various heat sources and sinks to assess the ability of lizard body temperatures to vary in the short term and to confirm the accuracy of our field readings. Chase studies in the lab showed that there was no significant change in the internal body temperatures of the lizards if they were chased to and from heat sources and sinks over a ten-minute period. The lizards appeared to be unable to maintain preferred laboratory temperatures precisely in the field.
139

LATE CRETACEOUS AND EOCENE PHREATOMAGMATIC VOLCANISM AND MAGMA-SEDIMENT INTERACTION IN THE BIG BEND AREA OF WEST TEXAS

Befus, Kenneth 28 July 2006 (has links)
This project examines two separate aspects of the volcanic evolution of the Big Bend area. Detailed mapping of phreatomagmatic, basaltic air-fall and base-surge deposits at Peña Mountain shows that they represent the erosional remnants of at least two maars. The deposits intertongue with the Campanian upper shale member of the Aguja Formation, increasing the known extent of Cretaceous volcanism in the Big Bend region. Zircon grains extracted from basalt bombs in the pyroclastic deposits yield a UPb SHRIMP-RG age of 76.6 ± 1.3 Ma. On the Pitcock Ranch and adjacent parts of the park, Eocene basaltic dikes and phreatomagmatic diatreme root zones show various styles of magma-sediment interaction with the Javelina, Black Peaks, and Hannold Hill Formations. Billowed dike margins, intrusive pillows, and different types of peperite developed in strata as old as the Late Cretaceous, which must have remained unconsolidated and rich in pore water into the Eocene.
140

Shallow-layer Soil Water Moisture Changes in Response to Rainfall on Green Roof Media

Zhang, Xiaoyu 28 July 2010 (has links)
This paper presents hydrologic data collected over an eight-month period from four different green roof test treatments. These data are to quantify changes in soil water moisture content in response to rainfall on a commercially-available medium and soil mixtures designed by researchers at TCU to assess the most effective medium in terms of water retention and recharge, and improve irrigation management by accurately determining when the green roof media should be watered to maintain optimum plant growth without using excessive water. Results showed that soils treated with a surface tile and gravel mulch perform best hydrologically, with highest storm water retention and moisture contents than a native soil with no surface cover or a commercially-available soil medium.

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