Thesis (M.S.)--Mississippi State University. Department of Civil and Environmental Engineering. / Title from title screen. Includes bibliographical references.

Thesis (M.Sc. Earth and Ocean Sciences)--University of Waikato, 2008. / Title from PDF cover (viewed September 17, 2008) Includes bibliographical references (p. 225-232)

Thesis (M.A.)--State University of New York at Binghamton, Department of Geological Sciences and Environmental Studies, 2005. / Includes bibliographical references.

Lake Eola is an eutrophic, land-locked lake located in downtown Orlando, Florida. It has a surface area of approximately 27 acres (11 .0 Ha) and a maximum water depth of 22 feet (6.7 meters) near the center. Sediment samples were collected from the lake bottom at various water depths and analyzed for physical characteristics and phosphorus content. Lake water samples were collected and analyzed for selected parameters as related to sediment phosphorus dynamics. Phosphorus release from agitated, aerobic sediment samples was measured in laboratory batch experiments. Phosphorus release from anaerobic hypolimnetic sediments was measured by utilizing~ situ isolation chambers. Results indicate that phosphorus release from anaerobic Lake Eola sediments can be described by the Freundlich isotherm, indicating that release may be a desorption process. Phosphorus budget calculations indicate that the phosphorus that accumulates in the hypolimnion of Lake Eola has the potential for increasing productivity when overturn occurs.

The karst Biscayne aquifer is characterized by a heterogeneous spatial arrangement of porosity, making hydrogeological characterization difficult. In this dissertation, I investigate the use of ground penetrating radar (GPR), for understanding the spatial distribution of porosity variability in the Miami Limestone presented as a compilation of studies where scale of measurement is progressively increased to account for varying dimensions of dissolution features. In Chapter 2, GPR in zero offset acquisition mode is used to investigate the 2-D distribution of porosity and dielectric permittivity in a block of Miami Limestone at the laboratory scale (< 1.0 m). Petrophysical models based on fully saturated and unsaturated. water conditions are used to estimate porosity and solid dielectric permittivity of the limestone. Results show a good correspondence between analytical and GPR-based porosity estimates and show variability between 22.0-66.0 %. In Chapter 3, GPR in common offset and common midpoint acquisition mode are used to estimate bulk porosity of the unsaturated Miami Limestone at the field scale (10.0-100.0 m). Estimates of porosity are based on the assumption that the directly measured water table reflector is flat and that any deviation is attributed to changes in velocity due to porosity variability. Results show sharp changes in porosity ranging between 33.2-60.9 % attributed to dissolution areas. In Chapter 4, GPR in common offset mode is used to characterize porosity variability in the saturated Biscayne aquifer at 100-1000 m field scales. The presence of numerous diffraction hyperbolae are used to estimate electromagnetic wave velocity and asses both horizontal and vertical changes in porosity after application of a petrophysical model. Results show porosity variability between 23.0-41.0 % and confirm the presence of isolated areas that could serve as enhanced infiltration or recharge. This research allows for the identification and delineation areas of macroporosity areas at 0.01 m lateral resolution and shows variability of porosity at different scales, reaching 37.0 % within 1.3 m, associated with areas of enhanced dissolution. Such improved resolution of porosity estimates can benefit water management efforts and transport modelling and help to better understand small scale relationships between ground water and surface water interactions. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

Methods are presented to acquire data from analytical ultracentrifugation experiments by computer using the absorption optical scanning system of the Beckman Model-E ultracentrifuge. A computer program was written which analyzes sedimentation velocity experiments by the van Holde - Weischet method and by the second moment method. The van Holde - Weischet method allows a high resolution analysis of sedimentation velocity data by eliminating the effects of diffusion on the shape of the moving boundary to provide sedimentation coefficients for a heterogeneous composition of a sample. The second moment method obtains the sedimentation coefficient by calculating the second moment point, by which the sedimentation coefficient is defined. Since it is impractical to manually analyze sedimentation velocity data by this method, these computer programs make an important analysis method available to the researcher. Using this computer program, it is now possible to analyze data to a higher resolution and accuracy than manual analysis of stripchart recordings would permit. Moreover, the time required for the analysis is greatly reduced. Data from sedimentation equilibrium experiments are analyzed by x² minimization. Further, a program was written for the acquisition of data to measure diffusion coefficients from quasi elastic light scattering experiments with a Langley Ford correlator. The analysis of autocorrelation spectra from light scattering experiments is performed by the Levenberg - Marquardt method, which allows fitting of data to nonlinear models. The model used allows the analysis of multicomponent systems by fitting to a sum of exponentials and a baseline. Traditional analysis of autocorrelation data by hand was limited to least squares fitting of the data to a linear model of one component without an optimized baseline, often an unrealistic approximation of the system. Analysis of autocorrelation data by nonlinear curve fitting increases both the accuracy and amount of data that can be analyzed. The development of the PPOL-1 208-n series of plasmids and of the miniplasmid pMX is described. These plasmids were designed to allow studies of in vitro transcription and chromatin structure after reconstitution with histones. The plasmids themselves were analyzed by sedimentation and diffusion studies using the computer programs. Sedimentation data is presented which suggests a new method for rapid estimation of S₀ (the sedimentation coefficient at zero concentration) for molecules which show a concentration dependency of the sedimentation coefficient. This is accomplished by linearly extrapolating van Holde Weischet distributions to zero concentration. Manual analysis of sedimentation velocity experiments to determine nonideality contributions required several experiments, computer analysis can provide this information in a single experiment due to the increased resolution of the method. Diffusion data for this plasmid DNA is used to demonstrate the feasibility of the multicomponent analysis presented here. Also, sedimentation measurements were carried out on reconstituted chromatin and on the effects of ethidium bromide on reconstituted chromatin. The programs were used to demonstrate significant changes in chromatin structure upon ethidium bromide binding. These changes involved the reduction of S of reconstituted plasmids upon addition of ethidium bromide as well as a reduction of heterogeneity of the sample. The data indicates the possibility of a forced exchange of nucleosomes between plasmids, as well as conformational changes in the chromatin structure. / Graduation date: 1993

Thesis (Ph. D.)--University of Washington, 2002. / Includes bibliographical references (leaves 240-251).

The research examines the sedimentary environments and provenance of the Balfour Formation of the Beaufort Group (Karoo Supergroup) in the Eastern Cape Province, South Africa. This Formation occurs in the southeastern part of the Karoo Basin. It consists of sedimentary rocks, which are an alternating siltstone, shale and mudstone succession with subordinate interbedded sandstone and subsequently intruded by Karoo dolerite in the form of sills and dykes. ithostratigraphically, the Balfour Formation is subdivided into five units namely, from the base to the top, the Oudeberg, Daggaboersnek, Barberskrans, Elandsberg and Palingkloof Members. The Balfour Formation is overlain by the Katberg Formation. This study involved field investigations in the vicinity of the towns of Bedford and Adelaide with integrated stratigraphical, sedimentological and petrological studies. A geological map was constructed after field investigations. Lithofacies of the Balfour Formation that were studied are characterised by sandstone facies (Sh, Sm, St, Sr, Sp) and fine-grained sediments (Fl or Fsm) which reflect point-bar, cut-bank, channel and floodplain deposits. Lithologically, the Oudeberg Member consists of sandstone of which some units are internally massive alternating with thin laminated siltstone and mudstone. The Daggaboersnek Member is characterised by regular, generally non-lenticular, overall stratification, in the Barberkrans Member consists of sandstone lithosomes, while the Elandsberg Member is an argillaceous unit, similar to the Daggaboersnek Member. The Palingkloof Member is composed predominantly of red mudstone that can be used to distinguish the Balfour Formation from the overlying Katberg Formation, which consists predominantly of sandstone. The stratigraphic sequence displays two fining upward megacycles of sedimentary deposits with change in the sediment supply pattern from low-sinuosity to high-sinuosity river systems which reflect both braid and meandering deposits, respectively. Sedimentary structures in the sandstone units and the provenance of the Balfour Formation indicate that these deposits were produced by rivers flowing from the southeast with minor drift towards the northwest. According to the composition of the sediments and their sequence of deposition the Formation represents a fluvial environment. Mineralogical and grain size data from the sandstones of the various members of the Balfour Formation indicate the same source area of granitic, metamorphic and older sedimentary rocks and show no significant petrographic differences. The petrographic and geochemical investigations confirmed the sandstone to be feldspathic litharenite and ultralithofeldspathic sandstone. The palaeocurrent investigation indicates the main provenance to have been situated to the southeast of the Karoo basin. Heavy-mineral concentrations within the sandstones also give an indication that the source had a transitional arc plate tectonic setting.

Particles mobilized by stormwater negatively affect receiving surface waters. Stormwater best management practices (BMPs) can reduce solids along with associated pollutants in runoff but engineers and environmental managers have been long vexed by the problem of choosing the optimal BMP for a given situation. A common BMP process for solids removal is sedimentation. This thesis addresses the question of whether the effectiveness (and thus choice) of a sedimentation device can be estimated (and thus optimized) from the particle size properties of runoff, which, in turn, could be associated with specific runoff zones or land uses. Presented here is a series of experiments to determine the solids-removal capabilities of a manufactured oil-water separator that also removes solids via sedimentation. A statistical model developed from the experimental data shows that, under normal operating conditions, influent particle size can be used to accurately estimate effluent total suspended solids (TSS) for BMPs of this type. Relationships between particle size and particle-bound metal concentrations for Cu, Zn and Pb were then obtained from the literature and incorporated into the model to allow estimates of metal removal efficiencies based on TSS and PSD. The model can be used with an arbitrary particle size distribution (PSD); this allows effluent quality predictions to be made considering that particle sizes entering stormwater BMPs could vary due to anthropogenic, hydraulic or hydrologic factors. To place these experimental and modeling results in the context of an urban environment, samples of deposited stormwater solids were collected from residential areas, commercial areas and an industrial zone in Portland, Oregon, and the PSD of each sample was determined using light obstruction particle sizing. PSDs ranging over sizes from 3μm to 200μm vary among these locations. Areas with high anthropogenic impact were found to have PSDs skewed toward the smallest particle sizes. The statistical model developed here was then used to show that the effluent quality of the BMP tested would differ depending on the locations where solids were collected. The evidence presented in this thesis thus indicates that device performance will correlate with geographic locations or land use zone and validates further investigation into delineating the City of Portland's characteristic runoff zones and using the runoff characteristics of each zone to map it to the most desirable treatment practices.