The purpose of the current study was to test an intervention aimed at increasing nurturing touch in families with young children. The effectiveness of the intervention was also be tested by examining family functioning and child behavior problems. The intervention was comprised of a manual on the topic of touch along with specific exercises involving touch for the family to do in the home. The primary research objective was to evaluate the effects of the touch intervention on touch in the home, family functioning, and child behavior. Based on this primary research objective, it was expected that: 1) The families who use the touch manual will demonstrate better touch, family functioning, and child behavior outcomes than the families who do not use the touch manual; 2) Families who use the touch manual for a longer period of time will demonstrate better touch, family functioning, and child behavior outcomes than families who use the manual for a shorter period of time. The secondary research objective was to investigate the psychometric properties of the Touch Survey. The participants in this study were families who had at least one adopted child between the six and twelve years of age. Participants completed demographic information and the Touch Survey, FAD, and CBCL at two-months and four-months. The results indicate that the psychometric properties of the Touch Survey are promising, although should be revised based prior to future use. The results also indicate that the family and child demographics have a larger effect on data between intervention and no intervention outcomes. However, it was found that touch and family functioning improve for participants who have been in the intervention for a longer time period. Implications, limitations, and ideas for future research are discussed.

The Barnett Shale was deposited in a deep, anoxic, basin during the Mississippian. High amounts of organic matter were preserved under the prevailing anoxic conditions along with fine-grained pelagic and hemipelagic sediment. The sediment was deposited in a foreland basin on the southern edge of the North American craton during a prolonged second-order highstand of sea level. Sediment was also introduced into the basin by turbidity currents and debris flows from surrounding shelfal environments. During the deposition of the Barnett Shale, sea level fluctuated many times, and during highstands of sea level, condensed sections formed in basinal settings. Condensed representing maximum flooding surfaces can be correlated across the Fort Worth basin using gamma ray logs.

Nanomaterials have attracted great attention in the past two decades due to their superior mechanical, thermal, chemical, electrical and optical properties entirely different from bulk materials, which lead to numerous potential applications in nanodevices and nanoelectronics, such as FETs, LEDs, single electron memory devices, spin polarized electronics, quantum computing, sensors, photonic crystals/devices, solar cells etc. Based on the previous work on Er-doped GeNWs, a core-shell nanostructure was built by introducing Zn/ZnO shell onto Er-doped GeNWs. It was found that Zn sources and corresponding surface modification processes (CVD and PVD) have important impact on Er<super>3+</super> PL and ZnO UV/visible PL due to Zn₂GeO₄ formation, which were confirmed by HRTEM and XRD measurements. In another work, Ge and Er were used to modify the surface of ZnO tetrapods. Both strong ZnO visible PL and Er<super>3+</super> PL were observed; considerable enhancement of Er<super>3+</super> PL was made possible by Ge deposition as a sensitizer layer. The Zn₂GeO₄ phase observed could either separate from the ZnO phase or mix uniformly with the ZnO phase. As a control system, Er/GeO_x/ZnO nanofibers were fabricated by electrospinning of selected sol-gel precursor solutions. These types of nanofibers exhibited strong Er<super>3+</super> near IR PL at 1.54 &mum after annealing to remove the polymer template. XRD spectra indicate that the Er/Ge/Zn mixture likely forms a disordered phase, especially with high Er<super>3+</super> concentrations, which contributes to the strong Er<super>3+</super> PL with the reduction of Er-Er interactions. In another work, the fabrication of F-doped ZnO nanowires was investigated on different substrates with or without carrier gas (Ar). ZnO UV/visible PL spectra indicate that F-doping diminished the intensity of defect light emission at ~2.4 eV. Furthermore, ZnO/F-doped ZnO coreshell NWs were fabricated either by PVD or CVD processes; the PVD method provides better crystalline shell structures after annealing. The last work describes the fabrication of porous Ge nanowires by the anodization of Ge nanowires (grown on Si substrates) using ethanolic HCl as an electrolyte. An initial cathodic Cu electrodeposition step is found to provide useful kinetic control of the pore morphology and to stabilize the nanowires attached to the Si surface. A systematic evaluation of the role of electrolyte composition, current/voltage density, and its duration on the resultant Ge NW morphology and structure have been carried out. Preliminary photoluminescence (PL) measurements suggest strong emission in the visible region. The electrochemical anodization mechanism is discussed involving the periodic localization of pores and a varying potential distribution of free electrons along 1D GeNWs.

Diffusion occurs in many biological, medical, laboratory and manufacturing processes. In this dissertation, multicomponent diffusion has been investigated for solutions containing high molecular-weight solutes using Rayleigh interferometry and dynamic light scattering (DLS) at 25 ºC. The first objective of this dissertation is to experimentally and theoretically investigate the effect of macromolecule polydispersity on macromolecule diffusion in water. We show diffusion measurements performed by Rayleigh interferometry can be used to characterize macromolecular polydispersity, and diffusion measurements performed by DLS can significantly differ from those obtained by Rayleigh interferometry if macromolecules are highly polydisperse. For macromolecule-additive-solvent mixtures, a corrective procedure was successfully developed to remove polydispersity effects and treat these systems as ternary systems. The second objective of this dissertation is to investigate multicomponent diffusion of a model macromolecule-additive-solvent ternary system. We use Rayleigh interferometry to determine the four multicomponent diffusion coefficients for the poly(ethylene glycol)-di(ethylene glycol)-water ternary system. This investigation shows how multicomponent diffusion can be used to 1) characterize macromolecule-additive thermodynamic interactions; 2) examine the role of preferential interactions and macromolecule solvation on the phenomenon of coupled diffusion. These studies were extended to poly(ethylene glycol)-salt-water ternary systems to characterize macromolecule-salt thermodynamic interactions. The third goal of this dissertation is to investigate multicomponent diffusion of drug-carrier-water systems. In pharmaceutical industry, diffusion parameters are crucial for modeling and predicting drug controlled release. Carriers, such as micelles can be added to drug formulations to enhance drug bioavailability and prolong drug retention. We use Rayleigh interferometry to determine the four multicomponent diffusion coefficients for drug-micelle-water ternary systems. Hydrocortisone and potassium naproxenate were used as model nonionic and ionic drugs respectively. The micelle of the surfactant tyloxapol was chosen as a model carrier. Drug solubility was measured as a function of surfactant concentration to quantitatively characterize drug-micelle binding. A theoretical model, describing coupled diffusion in micelle solutions and taking into account drug-micelle binding, counter-ion effects and micelle salvation, was successfully developed for both nonionic and ionic drugs. This study contributes to the fundamental understanding of drug diffusion in the presence of nano-carriers and provides guidance for the development of accurate models of diffusion-based controlled release.

Stacking faults and twins were identifying in SiC nanowires produced according three different synthesis methods. By direct observation of high resolution TEM images, analysis of Raman spectra, and from X-ray diffraction results we concluded that planar defects were present in all specimens, regardless the synthesis method. The study of TEM images revealed that concentration of defects was not uniform. The amount of stacking faults and twins varied between the samples, and seems to be dependent on the size of nanowires. Concentration of twins appeared to be highest in nanowires obtained from raw carbon blacks of small diameters. The quantitative analysis of concentration of defects was not conducted because Raman and conventional X-ray cannot discern stacking faults and twins. Therefore, the estimation of concentration of planar defects was based on the examination of TEM images. The application of two TEM modes, bright field and dark field, let to deduce that twins played a dominant role in observed defects. A minimum surface energy and strain energy argument was proposed to explain the formation of twins in the SiC nanowires. The high pressure measurements in DAC were performed and the results validated the core-shell model. The application of new carbon precursor revealed with new, highly efficient method of synthesis of SiC nanowires. We proved that it is possible to produce low-cost, catalyst-free, and high-yield SiC nanowires of 10 nm diameter and narrow size distribution. Morphology of the nanowires depended on carbon precursor used. That technique was described in details in Chapter IV. The model of typical nanowire, composed of crystalline SiC core, coated by thin, 2 nm amorphous SiC layer, was presented. After analysis of produced SiC nanowires we were able to construct the possible model of growth mechanism, and explain the differences in dimensions and morphology for nanowires, obtained from graphitized and not graphitized carbon blacks precursors. We deduced that vapor-solid growth mechanism is more plausible in nanowires synthesis from carbon black, than the vapor-liquid-solid mechanism.

This paper tests a model of adolescent treatment engagement within a residential drug treatment setting. Using a modified Theory of Planned Behavior (Ajzen, 1991), the model incorporates prior drug use, attitudes, subjective norms, and perceived social support as predictors of intentions to resist drug use and treatment engagement. The current study addresses a gap in the literature assessing the adolescent treatment process by drawing on the literature assessing adult populations and emphasizing the importance of social influences for adolescents. The sample included 407 adolescent clients from 7 residential drug treatment centers across the U.S. who completed surveys regarding an evaluation of themselves and treatment at intake and again 30-45 days later. Structural Equation Modeling was conducted to test the proposed model. Moderation analyses by gender revealed that social influences affect the treatment process differently for males and females. Implications for treatment interventions and directions for future research are discussed in terms of the final model and the role of social influences for gender.

Over the past century the Brazos River, the third largest river in Texas, has become a highly managed system due to the construction of dams and reservoirs. Currently the river provides seven billion gallons of water each year to surrounding cities, agriculture and industry. Impoundments along the river and increased water allocation have changed the magnitude and frequency of the flow, and thereby disrupted the natural hydrologic cycle. To date, numerous studies have reported on the fragmentation of major fluvial systems within the United States and the subsequent impact on sediment discharge. Similar studies along the Brazos River are scarce. This paper discusses the results of a one-year study examining sediment transport rates and channel bar morphology in the Brazos River near Glen Rose, Texas. All observations were made along a study site located below De Cordova Bend Dam at Lake Granbury. The project aimed at understanding the historic migration patterns of channel bars pre- and post-dam construction. This was achieved through the analysis of aerial photography and GIS. Additionally, the project monitored present sediment flux and channel bar response to understand short term changes within the system. Suspended load and bedload were measured over a range of flow conditions, and channel bars surveyed continuously to capture seasonal variability. Channel bar development is largely controlled by stream capacity and the availability of sediment, and therefore channel bars within our study area represent key observational features for understanding the current dynamics of the fluvial system. Results from this study indicate how this reach of the Brazos River has responded to the construction of a major impoundment, and how current conditions are shaping the channel morphology.

The Late Cretaceous Pen, Aguja and Javelina Formations and Tertiary Black Peaks, Hannold Hill and Canoe Formations are exposed on and around the Pitcock Rosillos Mountain Ranch, adjacent to Big Bend National Park, Texas. The objectives of my project were to produce a geologic map of these sedimentary strata on and around the Rosillos Mountains laccolith and to collect fossil vertebrates from the units of interest. I worked on unmapped areas of the Pitcock Ranch and tested the validity of the geologic map of the park produced by Maxwell et al. (1967) where it falls on the ranch. Numerous differences were found between the Maxwell et al. (1967) map and my observations, while many features coincide. The geologic map produced is important because it includes previously unmapped areas and revisions to a previously constructed map of the area.

Methyl mercury (MeHg) is an environmental contaminant affecting the health of wildlife. It was once thought that only aquatic consumers were at risk of MeHg contamination, but we now know emergent insects transport MeHg from aquatic systems to terrestrial food webs (MeHg flux). Factors regulating MeHg flux in emergent insects are currently unknown. This study tests the hypothesis that fish predation regulates insect emergence and flux of MeHg. The experiment utilized five ponds stocked with fish and five ponds without fish. Floating emergence traps were used to capture emergent insects. Fish significantly suppressed Hg flux in dragonflies and damselflies, significantly enhanced MeHg flux in caddisflies, and did not affect Hg flux in midges. Total MeHg flux was significantly greater in ponds without fish. This is the first study to show that fish have complex direct and indirect effects on insect emergence and the flux of MeHg out of ponds.

Woven into the thin, sandy soils, between the Fort Worth Prairie and the Broken Red Plains, lays a vanishing band of vegetation called the Western Cross Timbers. It is diverse woodland some trees and low shrubs, tangled vines, sandstone streams, and sprinkled with open glades. The place has an unkempt appearance, but it is a place where our history is rooted. The Western Cross Timbers is unknown to many people, some of who live under the trees canopies. My thesis begins as a framing narrative and hopefully culminates as a recovery narrative for the residents of 3 North Central counties, Jack, Wise, and Young. Through field study, vegetation sampling, literature reviews, and interviews, this thesis attempts to tell the story of the Western Cross Timbers. And through this story, the communities who call the Western Cross Timbers home, can see the potential they hold for future greatness.