Political boundaries frequently define local floras. This floristic project takes a geological approach inspired by Dalea reverchonii (Comanche Peak Prairie Clover), which is endemic to glades of the Walnut Formation. The Cretaceous Walnut Formation (Comanchean) lies on the drier western edge of the Fort Worth Prairie in North Central Texas. Its shallow limestone soils, formed from alternating layers of hard limestone and clayey marl, support a wide variety of habitats. Glades of barren limestone typically appear on ridgetops, grassland savannas form on eroding hillslopes, and seeps support a variety of hyperseasonal vegetation. Vouchers were collected from January 2010 to December 2011 resulting in 79 families 268 genera 423 species and 437 taxa. The largest families being the Poaceae, Asteraceae, and Fabaceae. Results indicate floristic affinities to Limestone Cedar Glades of the Southeastern United States and to calcareous Apacherian Savannas of Southwestern North America.

Diffusion of macromolecules in aqueous solutions is important for many laboratory, biological, and manufacturing applications. However, aqueous solutions containing macromolecules often contain other additives. An important feature of these multicomponent mixtures is the macromolecule-additive interaction. Due to this interaction, the additive concentration gradient can induce macromolecule diffusion and vice versa. This phenomenon is known as coupled diffusion and is described by multicomponent diffusion coefficients. This thesis reports the experimental investigation of multicomponent diffusion coefficients for the Poly(ethylene glycol)-KCl-water ternary system at 25 ºC using Rayleigh interferometry. These coefficients were used to determine PEG-salt interaction. Furthermore, isopiestic experiments were performed to demonstrate that multicomponent diffusion yields accurate thermodynamic parameters. Fundamentally, this work has provided a significant contribution to the connection between diffusion and thermodynamics. Moreover, significant coupled diffusion between PEG and KCl was observed due to a large PEG hydration. Thus, PEG concentration gradients can be used to induce diffusion of other molecules in water for potential applications in controlled-release and micro-fluidic technologies.

Sediment comprising the gross reservoir (Barnett base-Morrowan top) was first deposited over Paleozoic strata during marine transgression, followed by highstand aggradation and progradation. Chronostratigraphic cross sections illustrate relationships between flooding events and facies belts in the gross reservoir. The reservoir model supports mineralogic trends identified in the gross reservoir that grade from carbonate to silica to clay-rich in a northwest/southeast orientation across the Fort Worth basin. Facies analyses identify organic richness associated with the gross reservoir increases south/southeast away from the Newark East field. Gamma ray response in the Barnett Shale > 100 API units indicates > ~4% vol. TOC, the basal limit accepted for commercial production in unconventional shale reservoirs. High TOC indicates greater porosity and hydrocarbons present in the Barnett Shale. Based on organic richness, mineralogic composition, and geochemical considerations, southeastern Tarrant, northern Johnson, and northwestern Ellis counties contain the best reservoir qualities for gas generation and accumulation.

A scaffolded view of the human mind proposes that we use our pre-verbal, physically based notions of the world to organize complex ideas and concepts that we acquire later on in life (Williams, Huang, & Bargh, 2009). We used this perspective to test the hypothesis that hunger is used to aid in the conceptualization of the later developing visceral state of sexual desire. We predicted that hungry people would rate the opposite-sex models as more attractive than satiated people (Study 1) and that pairing the models with appetitive and contaminative adjectives would respectively increase and decrease the attractiveness ratings made by hungry people but not sated people (Study 2). Consistent with our hypothesis, Study 1 found that hungry people perceived opposite-sex targets to be more attractive than those who had just eaten. The results from Study 2 did not support our hypothesis.

Wind energy represents a potential threat to grassland birds. We used an area search methodology to survey winter grassland birds Wolf Ridge Wind, LLC. To investigate the displacement of birds by wind turbines, I used logistic regression to test for patterns in plot occupancy. Plot occupancy for Savannah Sparrows, meadowlarks, Sprague's Pipits, and `flyers' (longspurs, Horned Larks, and American Pipits) did not change with distance to turbine. As distance to turbine increased, plot occupancy for the Le Conte's Sparrow increased. To ensure that variation in suitable habitat across distance to turbine did not bias logistic regression results, I used an ecological niche modeling method that determined which plots were suitable Le Conte's Sparrow habitat. Logistic regression using only suitable plots for Le Conte's Sparrows confirmed that plot occupancy increased with distance to turbine. Predator evasion strategy and tolerance for disturbance may be two indicators for susceptibility to displacement by turbines.

Metal-organic frameworks (MOFs) are dynamic three-dimensional networks that reveal unprecedented gas adsorption and storage capabilities, catalytic function, and other useful properties such as luminescence and magnetism. While we begin to see many possibilities for applications of these polymers, the goal of true rational design will only be achieved on the basis of intensive systematic investigations. The following five chapters will detail our efforts to advance the research goal of utilizing mild synthetic methods to investigate factors controlling the structure of crystalline, thermally stable coordination polymers utilizing N-functionalized phosphonic acids. Studies into preferred metal geometry and coordination modes, ligand flexibility, counterion, solvent, and pH will be addressed to discern useful patterns for future synthetic endeavors. Chapter 1 presents an introduction to the terminology, structural diversity, and chemical applications of this emerging field. Chapter 2 describes the synthesis and crystallographic analysis of five polymers employing a bifunctional, zwitterionic 2-(pyridyl)phosphonic acid ligand, 2PyHPO₃H, and salts of Zn(II), Cd(II), Hg(II), and Ag(I). Chapter 3 reports the influence that cation choice and ligand flexibility have on the dimensionality and structure of eight products containing Mn(II), Co(II), Fe(II), Fe(III), Ag(I), and Pb(II) cations and 2-(pyridylmethyl)phosphonic acid, 2PyCH₂PO₃H₂. Chapter 4 explores the use of (aminomethyl)phosphonic acid (NH₃CH₂PO₃H) as a bifunctional organic linker for the production of coordination polymers. The substitution of the amino group for the rigid heterocyclic ring of 2-(pyridylmethyl)phosphonic acid results in two-dimensional organophosphonate frameworks with Zn(II), Mn(II), Co(II), Cu(II), Gd(III), Sm(III), and Yb(III) cations. Chapter 5 relates our efforts to evaluate the relationships between metal choice, counterion, and ligand geometric constraints on polymer architectures. Ca(II), Co(II) and Zn(II) salts produce both dimers and polymers with 2-(pyridylmethyl)phosphonic acid, and Ag(I) and Zn(II) salts form unique polymers with 3- and 4-(pyridylmethyl)phosphonic acid. Crystal structures of the compounds allow us to compare and contrast the final products of the self-assembly process. Other analytical techniques, such as IR, NMR, TGA, and mass spectroscopy, are used to support and interpret the crystallographic results.

Tremendous growth in wind energy development in the Great Plains has the potential to negatively impact the nesting ecology of many grassland birds. In 2010-2011, I monitored density of the Dickcissel, Grasshopper Sparrow, and Eastern Meadowlark at Wolf Ridge Wind Farm in north-central Texas. Eastern Meadowlark and Grasshopper Sparrow density did not vary with distance to turbine. However, Dickcissel density was greatest 301-400 m from turbines in 2010, but Dickcissel density did not vary with distance in 2011. I located 81 Dickcissel nests and 18 Grasshopper Sparrow nests in 2010 and 112 Dickcissel nests and 8 Grasshopper Sparrow nests in 2011. Nest success of Dickcissels and Grasshopper Sparrows did not vary with distance to turbine. In 2010 and 2011, vegetation height and density was significantly greater at nests than at non-nest locations. My data indicate that Dickcissel nesting ecology is not negatively impacted by the presence of wind turbines.

This paper presents hydrologic data collected over a six month period from four different green(living) roof test module treatments. These data are part of a larger study on applying biomimicry design principles to advance the implementation of successful living roofs in North Central Texas. The native soil of the Walnut and Goodland geologic formations, specifically the soil of these formations barrens communities is analyzed as part of the biomimicry design process. Basic soil characteristics are described along with a simple analysis of saturated weights for native soil and a commercial green roof medium. The percent rainfall retention capacity of native soil systems are compared to a commercial soil benchmark. This dataset is put into the context of historical rainfall exceedence frequencies. Native barrens communities are viable models for green roofs in North Texas; they outperformed the commercial medium tested in rainwater retention at the cost of slightly greater weight.

Currently no reliable paleomagnetic pole for the Kalahari craton exists for the time period ~900-750 Ma, and it is the purpose of this thesis to acquire the first such pole. Here I report the results of paleomagnetic analyses from 47 sites from Neoproterozoic rocks within the Richtersveld Igneous Complex (~890 Ma), the older Bremen Complex (~890 Ma), and the Gannakouriep dike swarm (~795-790 Ma) within southern Namibia and adjacent parts of South Africa. The resulting grand mean pole obtained for the Kalahari craton lies at 73.9°N, 233.9°E (A95 = 4.5°). Comparison with published paleomagnetic poles from rock units of similar age from the Congo craton to the north supports a model in which the two cratons were originally separated by a wide ocean basin prior to the formation of the Gondwana supercontinent. However, additional work from the Congo craton is needed to test this hypothesis.

There are a number of useful properties that make mesoporous silicon (PSi) an interesting candidate as an active biomaterial: resorption in vitro/in vivo with a negligible inflammatory response; a porous morphology, thereby permitting drug release; and an ability to stimulate calcification. Recent work from our lab has focused on nanostructured composite materials composed of PSi and common biopolymers such as poly (ε-caprolactone) (PCL). When fabricated in microfibrous form, such composites can stimulate the deposition of calcium phosphate (the inorganic component of bone) not only in simulated body fluid (SBF), but also on the surface of cell layers adhering to the scaffolds during proliferation. Human mesenchymal stem cells and mouse stromal cells were used for cell proliferation and differentiation assays, along with scaffold attachment experiments. The results of alkaline phosphatase expression as a specific biomarker for mensenchymal to bone cell differentiation show that the scaffolds have the ability to mediate such processes. Cell ultra-structural studies using transmission electron microscopy (TEM) also reveal that PSi plays a role in accelerating the calcification process. Drug loaded PSi/PCL composites also have the potential to be used as target drug delivery vehicles. In one study, PSi was loaded with Cis (2, 2´- bipyridine) dichloro ruthenium (II) (CBDR) and Tris (2, 2´- bipyridine) ruthenium chloride (TBRC) as model hydrophobic and hydrophilic drugs, respectively. In order to study how the spatial location of the loaded PSi affects the drug release behaviors, two types of composites were prepared: one is where drug loaded PSi was fully encapsulated into PCL fibers; the other involved drug loaded PSi surface embedded onto PCL fibers. Both of the release profiles show the same trend in that the initial release of CBDR or TBRC from fully encapsulated PSi in PCL is much slower than that released from surface embedded PSi. The controlled-release of CBDR and TBRC both depend on both the amount of drug loading and their spatial distribution in the PCL fibrous scaffolds. Overall, the results show that electrospun PSi composites can be considered as biocompatible scaffolds with the potential as drug delivery materials for orthopedic tissue engineering applications.