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Development Of Hydraulic Relationships For Estimating In-Bank River Discharge Using Remotely Sensed Data, David Michael Bjerklie

Doctoral Dissertations

An evaluation of river hydraulic data currently or potentially available from satellite and other remote platforms was completed, and a set of discharge estimation models proposed that can use the remotely sensed information to estimate discharge with reasonable accuracy. Reasonable accuracy is defined as within +/-20% of the observed on average for a large number of estimates. The proposed estimation models are based on the Manning and Chezy flow resistance equations, and utilize combinations of potentially observable variables including water-surface width, maximum-channel (or bankfull) width, mean water depth, mean maximum-channel depth, mean water velocity, and channel slope. Both statistically and …

Effective Elastic Properties Of Two -Dimensional Solids With Inhomogeneities Of Irregular Shapes, Jindrich Novak

Doctoral Dissertations

This work investigates the effective elastic properties of two-dimensional solids with inhomogeneities of various shapes. We develop a special procedure to evaluate the contribution of irregularly shaped inhomogeneities to these properties. The method can also be used to investigate the stress concentrations around the inhomogeneities. The procedure is based on the analysis of a representative volume element. We express the contribution of each inhomogeneity to the overall moduli of the composite in terms of the compliance contribution tensor. To calculate the components of this tensor, we devise a method that combines analytical and numerical approaches: Kolosov-Muskhelishvili complex variable technique and …

Multiple Steady Solutions And Bifurcations In The Symmetric Driven Cavity, Kahar Bin Osman

Doctoral Dissertations

The symmetric driven cavity with sinusoidal forcing for two- and three-dimensions is considered. Results are obtained via numerical computations of the Navier Stokes equations with constant density. The numerical integration is a splitting method, using the Crank-Nicholson method for linear terms and the second-order Adams-Bashforth method for the non-linear terms. Spatial derivatives are evaluated with finite differences, and matrix equations are treated with SOR by lines. The results show symmetric solutions for low Reynolds numbers and asymmetric solutions for higher Reynolds numbers. Subcritical bifurcations are observed for two-dimensional flow. Unsteady flow behavior occurs at higher Reynolds number. Three-dimensional simulations for …

Contributions To Predicting Contaminant Leaching From Secondary Materials Used In Roads, Defne S. Apul

Doctoral Dissertations

Slags, coal ashes, and other secondary materials can be used in road construction. Both traditional and secondary materials used in roads may contain contaminants that may leach and pollute the groundwater. The goal of this research was to further the understanding of leaching and transport of contaminants from pavement materials. Towards this goal, a new probabilistic framework was introduced which provided a structured guidance for selecting the appropriate model, incorporating uncertainty, variability, and expert opinion, and interpreting results for decision making. In addition to the framework, specific contributions were made in pavement and embankment hydrology and reactive transport, Bayesian statistics, …

The Influence Of Urbanization On Runoff Generation And Stream Chemistry In Massachusetts Watersheds, Brian A. Pellerin

Doctoral Dissertations

The conversion of forested and agricultural land to suburban and urban landscapes is a dominant land use change dynamic in the United States and has implications for watershed hydrology and water quality. Here I evaluate the effect of integrated landscape features (e.g., percent residential or developed) and watershed-scale attributes influenced by urbanization on stream nutrient concentrations in headwater catchments in Massachusetts. In addition, I evaluate the importance of surface versus subsurface flow paths during rainfall events in stormflow generation in a small urban catchment. The percentage of residential land explains 52% of the variability in mean annual nitrate (NO3) concentrations …

Study Of The Enhancement Effect Of Cyclopentadecanolide On Protein Permeation Through Lipid Membranes, Zhengmao Li

Doctoral Dissertations

Intranasal drug delivery has been a topic of increasing interest for a decade as a convenient and reliable method for the systemic administration of drugs. The low bioavailability of simple formulation of protein drugs, such as insulin, can be greatly improved by using permeation enhancers. We studied the effect of cyclopentadecanolide (CPE-215RTM) as a permeation enhancer in protein release through lipid bilayer membranes. We successfully designed a novel in-vitro membrane permeability model using liposomes and performed a series of transmembrane protein release experiments. These were carried out under a wide range of conditions in the presence of different permeation enhancer …

Nucleation And Growth Kinetics Of Tin And Tin -Silver Alloy During Initial Stages Of Electrodeposition, Zhongqin Zhang

Doctoral Dissertations

Electrodeposition has played an essential role in electronics packaging because it gives superior thickness control for chip interconnects. Pure tin, tin-silver and tin-silver-based solders have been identified as leading candidates for lead-free solders due to the desirable melting point, good creep resistance and thermo-mechanical behavior.

The initial stage of electrodeposition, or the formation of small clusters of atoms (nuclei), is significant in the overall electrodeposition kinetics, as well as the appearance, structure, and properties of the resulting coatings. In this work, nucleation and growth kinetics of tin and tin-silver electrodeposition on copper and nickel substrates were investigated by electrochemical methods …