Digital Commons Network^™

Characterization Of Prokaryotic Diversity In A Chlorinated Solvent-Contaminated Bedrock Aquifer Using Denaturing Gradient Gel Electrophoresis, Ribosomal Dna Sequencing, And Real Time Pcr, Walid Naser

Doctoral Dissertations

A culture-independent molecular phylogenetic approach was implemented to investigate spatial and temporal variations in microbial diversity and abundance in a chlorinated solvent-contaminated bedrock aquifer. Core and groundwater samples were collected from several boreholes and included the following samples: (1) groundwater that was associated with the core, (2) open fractures and (3) partially mineralized sealed fractures (PMSF) exposed by striking the core with a surface-sterilized geology hammer. DNA representing the attached and unattached microbial communities was extracted from these samples, and the 16S rRNA gene was amplified with primers specific for Bacteria, Archaea, sulfate reducers, Geobacteraceae family, Dehalorespirers (Dehalococcoides sp. and …

A Wavelet-Based Cmac For Enhanced Multidimensional Learning, Brian P. Kirk

Doctoral Dissertations

The CMAC (Cerebellar Model Articulation Controller) neural network has been successfully used in control systems and other applications for many years. The network structure is modular and associative, allowing for rapid learning convergence with an ease of implementation in either hardware or software. The rate of convergence of the network is determined largely by the choice of the receptive field shape and the generalization parameter. This research contains a rigorous analysis of the rate of convergence with the standard CMAC, as well as the rate of convergence of networks using other receptive field shape. The effects of decimation from state-space …

Some Contributions To The Hydraulic Characterization Of Fractured Bedrock Formations, Gonzalo Pulido

Doctoral Dissertations

During 3 years of investigation at the BBC field site, research has led to developments in bedrock monitoring, groundwater sampling, formation hydraulic testing, and the conceptual model of formation hydraulics. This dissertation presents a field device, two hydraulic test methods, and one method of hydraulic test analysis developed to assist in the hydraulic characterization of fractured bedrock formations. It also presents the use of these tools in the development of the Conceptual Hydrogeologic Model for a fractured bedrock formation contaminated with chlorinated solvents. The field device was named the Multipurpose Packer System (MPS), a discrete-interval isolation system for the sampling …

Bedrock Geology Of The Seacoast Region Of New Hampshire, United States, Jose Cruz Escamilla-Casas

Doctoral Dissertations

The seacoast region of New Hampshire is underlain by two lithotectonic belts: the Rye Complex (RC), and the eastern portion of the Merrimack Group (MG). The Rye Formation and the Breakfast Hill member constitute the RC; the Kittery, Eliot, and Berwick Formations, the MG. The stratigraphic order interpreted in this study places the Kittery Formation transitionally above the Eliot, and identifies the contact between the Berwick and the Eliot Formations as a fault.

Study of folds using a variant of the Fourier series analysis indicates that the degree of asymmetry and shape of folds in the MG and the RC …

Factors Affecting Plant Community Composition And Dynamics In The Ossipee Pine Barrens, New Hampshire, Lauren Fredrick Howard

Doctoral Dissertations

Forty-one 0.25 ha sites were sampled in the Ossipee Pine Barrens to identify and describe tree community types and investigate factors controlling forest composition and dynamics. Every site had three site-time assemblages (STA's) representing past, present, and future trees. Past (1952) vegetation was calculated based on reverse growth estimates of current stems and stumps. Future (2052) vegetation was predicted by current sapling (<10 cm dbh and ≥1 m tall) relative densities.

Cluster analysis produced three community types from 121 STA's: pitch pine, mixed pine-hardwoods, and red maple. Pitch pine communities comprised 63% of sites in 1952, but declined since. Mixed pine-hardwoods peaked at 58% in 2002, but were …

Hydrodynamic Behavior And Thermal Stability Of A Pegylated Protein: Studies With Hen Egg Lysozyme, Yatin R. Gokarn

Doctoral Dissertations

We studied the effect of covalent attachment of polyethylene glycol (PEGylation) on the hydrodynamic behavior and thermal stability of a model protein---Hen Egg Lysozyme (HEL). HEL was modified with a linear, 20-kD, PEG to produce mono (PEG1-HEL), di (PEG2-HEL), and triPEGylated (PEG3-HEL) species.

The hydrodynamic properties of HEL were altered upon PEGylation. A decrease in sedimentation (s) and diffusion (D) coefficients was observed for all three PEG-HEL molecules in comparison to HEL (1.81 s). Despite differences in molecular weights of the PEG-HEL molecules (∼34, 55 and 80 kD), their s values were very close (1.0--1.1 s). Significant hydrodynamic non-ideality was …

Vocational Science And The Politics Of Independence: The Boston Marine Society, 1754--1812, Matthew Gaston Mckenzie

Doctoral Dissertations

Between 1754 and 1812 the Boston Marine Society developed vocational scientific practices adapted from day-to-day work routines to expand the navigational knowledge of New England's coastlines. For this reason, the Marine Society's navigational work suggests important parallels with the history of colonial science in other areas during the late eighteenth century. Notwithstanding most other studies in the history of American science, the Boston Marine Society indicates that colonial Boston shipmasters were not dependent upon learned societies for their navigational research needs. Rather, they adapted their mutual aid society and developed methodologies to collect navigational observations, analyze them for reliability and …

Active Disturbance Cancellation In Nonlinear Dynamical Systems Using Neural Networks, John C. Canfield

Doctoral Dissertations

A proposal for the use of a time delay CMAC neural network for disturbance cancellation in nonlinear dynamical systems is presented. Appropriate modifications to the CMAC training algorithm are derived which allow convergent adaptation for a variety of secondary signal paths. Analytical bounds on the maximum learning gain are presented which guarantee convergence of the algorithm and provide insight into the necessary reduction in learning gain as a function of the system parameters. Effectiveness of the algorithm is evaluated through mathematical analysis, simulation studies, and experimental application of the technique on an acoustic duct laboratory model.

Pattern Recognition For Electric Power System Protection, Yong Sheng

Doctoral Dissertations

The objective of this research is to demonstrate pattern recognition tools such as decision trees (DTs) and neural networks that will improve and automate the design of relay protection functions in electric power systems. Protection functions that will benefit from the research include relay algorithms for high voltage transformer protection (TP) and for high impedance fault (HIF) detection. A methodology, which uses DTs and wavelet analysis to distinguish transformer internal faults from other conditions that are easily mistaken for internal faults, has been developed. Also, a DT based solution is proposed to discriminate HIFs from normal operations that may confuse …

Modular Machine Learning Methods For Computer-Aided Diagnosis Of Breast Cancer, Mia Kathleen Markey '94

Doctoral Dissertations

The purpose of this study was to improve breast cancer diagnosis by reducing the number of benign biopsies performed. To this end, we investigated modular and ensemble systems of machine learning methods for computer-aided diagnosis (CAD) of breast cancer. A modular system partitions the input space into smaller domains, each of which is handled by a local model. An ensemble system uses multiple models for the same cases and combines the models' predictions.

Five supervised machine learning techniques (LDA, SVM, BP-ANN, CBR, CART) were trained to predict the biopsy outcome from mammographic findings (BIRADS™) and patient age based on a …

Fuzzy Product -Limit Estimators: Soft Computing In The Presence Of Very Small And Highly Censored Data Sets, Kian Lawrence Pokorny

Doctoral Dissertations

When very few data are available and a high proportion of the data is censored, accurate estimates of reliability are problematic. Standard statistical methods require a more complete data set, and with any fewer data, expert knowledge or heuristic methods are required. In the current research a computational system is developed that obtains a survival curve, point estimate, and confidence interval about the point estimate.

The system uses numerical methods to define fuzzy membership functions about each data point that quantify uncertainty due to censoring. The “fuzzy” data are then used to estimate a survival curve, and the mean survival …

Comparative Performance Of Rubberized Hot Mix Asphalt Under Alf Loading, Hanlin Qin

Doctoral Dissertations

In response to the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991, Louisiana constructed five projects to evaluate several methods of using discarded tire rubber in highway pavements. The field performance was quite variable. To achieve the agreement among state agencies on the engineering benefits of using crumb rubber modifier (CRM) in HMA pavement and to define the circumstances where the LaDOTD can use asphalt rubber materials in the most cost effective way, a full-scale research program has been conducted at the Louisiana Transportation Research Center (LTRC) to evaluate the performance of CRM-HMA asphalt pavement under Accelerated Loading Facilities (ALF). …

Behavior Of Nano-Engineered Platelets In A Coronary Artery Stenosis Model, Hua Ai

Doctoral Dissertations

Cardiovascular disease is the leading cause of death in North America. Cardiac infarction caused by thrombus plaque rupture can often lead to sudden death. Arterial stenosis caused by atherosclerosis is an important precursor leading to thrombus formation. Shear stress, abnormal lipid metabolism, and subendothelial layer exposure are the major contributors to arterial thrombus formation. Platelet activation by the above factors, followed by adhesion is the basic sequence in thrombus formation.

Platelets were encapsulated with nanofilm in order to reduce platelet activation and adhesion under high shear stress. Polyions, nanoparticles and immunoglobulins were assembled in nano-organized shells on fixed bovine platelets …

Modeling And Experimental Verification Of Growth Of An Axisymmetric Cylindrical Rod By Three-Dimensional Laser-Induced Chemical Vapor Deposition, Qing Chen

Doctoral Dissertations

Three-dimensional laser-induced chemical vapor deposition (3D-LCVD) is a recently developed micro-manufacturing process that holds great potential for the production of complex microstructures with high aspect ratio. A laser beam is focused through a vacuum chamber window onto a movable substrate. The heat from the laser at or near the focal spot on the substrate induces the decomposition reaction of precursor gas in the chamber. As a result, solid-phase reaction products are deposited on the substrate to form the microstructure. In this dissertation, a numerical model is developed for simulating kinetically-limited growth of an axisymmetric cylindrical rod by pre-specifying the surface …

Air Quality Impact Evaluation Of A Hypothetical Fire-Fighter Training Facility, William Glenn Fuller

Doctoral Dissertations

Human Health Risk Assessments (HHRAs) have become a required component in the permitting process for hazardous waste incinerators and boilers and for closure or evaluation of chemical and petroleum facilities. However, although not currently required, these evaluations are also essential for additional daily processes having the potential to adversely impact the environment. One such process includes emissions produced from a firefighter training facility. Firefighter training facilities perform scenarios to enhance the firefighting ability of the trainees. Three typical scenarios conducted at such a facility include air rescue and firefighting, building fire simulation, and propane system fires. During the course of …

A New Long -Term Design Model For Rehabilitation Pipe Liners, Shanyun Wang

Doctoral Dissertations

Thin-walled plastic pipe liners are routinely used to rehabilitate structurally sound host pipes that have lost their hydraulic integrity. Such liners are often installed below the water table and are consequently subjected to external hydrostatic pressure which may lead to creep-induced radial deflections and eventual collapse of the liner within the host pipe. Most of the current liner design model is based on the extension of short-term model to a long-term buckling liner design method. The objective of this thesis is to examine and provide a correction factor C* to allow short-term liner buckling models to be more accurately used …

Testing For The Significance Of Induced Highway Travel Demand In Metropolitan Areas, Lawrence Craig Barr

Doctoral Dissertations

The theory of induced growth in vehicle travel hypothesizes that highway improvements which add capacity to a specific corridor or regional transportation network will attract increased levels of vehicle traffic. This relationship of highway capacity to travel demand is an important consideration when evaluating how effective highway expansion alternatives will be in solving transportation problems. Two different but complementary empirical studies were conducted to quantify the effect of highway system improvements on travel behavior. In the first study, I apply ordinary least squares regression models to estimate travel demand elasticities with respect to travel time using travel survey data from …

Seafloor Geology, Deglacial History, And Early Post-Glacial Evolution Of Eastern Juan De Fuca Strait, Antony Trevor Hewitt

Doctoral Dissertations

Seismic-reflection data, bathymetric data, and sediment cores were used to map the seafloor geology of eastern Juan de Fuca Strait, and interpret the stratigraphy in terms of the latest deglacial episode and associated sealevel change. The surficial geologic units comprise bedrock (unit 1), ice-contact diamicton (unit 2), glacial-marine sediments (unit 3), and post-glacial sediments (unit 4). Bedrock crops out near Vancouver Island, and diamicton crops out in the numerous morainal banks. A series of banks running roughly north-south in the middle of the strait divides it into two areas based on the main surficial units; post-glacial sediments dominate to the …

Human -Machine System Design Optimization For Nondeterministic Spacecraft Anomaly Determination/Resolution, Kriss Quinn Hunold

Doctoral Dissertations

This research examines the dependence of knowledge on decision making with varying levels of uncertainty or non-deterministic situations. The work presented outlines a global approach that is not limited to a specific case study example, but can also be translated to other systems requiring operators, a degree of automation, time constraints, remote control, and high levels of personnel expertise. The specific objective of this study was to address the uncertainty inherent in satellite command and control and to assess and understand the role of human knowledge in the combined human-machine system unit. This research focused solely on the user component …

Physical And Chemical Characterization Of Single Atmospheric Aerosols: Laboratory Studies Of Interactions Of Acidic Trace Gases With Sea -Salt Aerosols, And, Development Efforts For An Aerosol Charging System Using A Corona Discharge, Matthew Brigham Loomis

Doctoral Dissertations

There has long been an interest for in situ analysis of single atmospheric aerosols. To this end, the Flytrap instrument was developed under a NASA Phase I and Phase II Small Business Innovative Research Grant. The centerpiece of the instrument was a spherical void electrodynamic levitator that was used to suspend and optically characterize the physical and chemical properties of individual aerosols. Physical measurements of the aerosols were conducted with the aid of a Mie scattering system while chemical characterization was conducted with a Raman spectroscopy microprobe. A large effort focused on development of a system for charging and trapping …

Quantifying Groundwater Discharge Using Thermal Imagery And Conventional Groundwater Exploration Techniques For Estimating The Nitrogen Loading To A Meso-Scale Inland Estuary, Robert M. Roseen

Doctoral Dissertations

This dissertation presents the results of a study to evaluate groundwater inflow and nutrient loadings to the Great Bay Estuary, New Hampshire. The evaluation of inflow was accomplished independently by two methods: one, used thermal imagery, and the other, piezometric mapping. The thermal imagery method assessed groundwater that was observed to discharge within the intertidal zone of an inland estuary. The groundwater piezometric mapping method used the monitoring wells around the bay to create an overall piezometric map of the near-bay area. Groundwater discharge was evaluated with respect to flow, concentration, and ultimately nitrogen loading to coastal waters. The results …

Diels -Alder Reactions Of [60]Fullerene With 1,2,4,5-Tetrazines And Additions To [60]Fullerene-Tetrazine Monoadducts, Mark Christopher Tetreau

Doctoral Dissertations

The Diels-Alder reaction between [60]fullerene and 1,2,4,5-tetrazines was studied. Under conditions of total darkness, [60]fullerene reacts with tetrazines to form bicyclic intermediates which immediately extrudes nitrogen to yield C2nu symmetric monoadducts. Thus, 3,6-diphenyl and 3,6-di-(2 '-pyridyl)-1,2,4,5-tetrazines react with [60]fullerene to form the corresponding C2nu symmetric monoadduct. To successfully synthesize these [60]fullerene-tetrazine monoadducts, the Diels-Alder reactions must be run in total darkness. In the presence of light and acid catalyst, the monoadducts are susceptible to nucleophilic attack by water leading to novel hydration/rearrangement products that contain 4,5-dihydropyrazole groups nested atop the [60]fullerene skeleton.

The [60]-fullerene-tetrazine monoadducts also react with primary amines …

Application Of Characteristic Mode Analysis To Variable Antenna Placement On Devices Operating In The Near -Resonant Range, David Anthony Strohschein

Doctoral Dissertations

As antenna sizes on portable wireless devices decrease to the dimensions of the device itself and to that of the operating wavelength, the system begins to operate in the near-resonant frequency range. Currently, a straightforward synthesis approach for determining optimal antenna placement within such near-resonant range systems does not exist. Previously, characteristic mode analysis had only been applied to systems with constant geometry that operated in the near-resonant range and the system had constant characteristic modes independent of the probe location. Successful application of characteristic mode analysis to radiating systems with a constant characteristic mode response suggest that a similar …

Diagnosing Interoperability Problems And Debugging Models By Enhancing Constraint Satisfaction With Case -Based Reasoning, Mohammed Houssaini Sqalli

Doctoral Dissertations

Modeling, Diagnosis, and Model Debugging are the three main areas presented in this dissertation to automate the process of Interoperability Testing of networking protocols. The dissertation proposes a framework that uses the Constraint Satisfaction Problem (CSP) paradigm to define a modeling language and problem solving mechanism for interoperability testing, and uses Case-Based Reasoning (CBR) for debugging interoperability test cases.

The dissertation makes three primary contributions: (1) Definition of a new modeling language using CSP and Object-Oriented Programming. This language is simple, declarative, and transparent. It provides a tool for testers to implement models of interoperability test cases. The dissertation introduces …

Birth, Death And Taxis: North Atlantic Right Whales In The Twenty-First Century, Scott Douglas Kraus

Doctoral Dissertations

Twenty two years of North Atlantic right whale data were analyzed. Several measures indicate reproduction in North Atlantic right whales is in a decline. Calving intervals have increased from about 3.3 years in the 1980's to over 5 years, and the age of first parturition is estimated to be 11 years. Females may lose calves before they are detected, artificially increasing the apparent age of first parturition and possibly affecting estimates of calving interval. Northern feeding habitat use patterns do not appear to affect reproduction.

Right whale mortality data was analyzed by age, sex, and habitat use patterns. A total …

Gendered Work: Women's Paid Labor In Barre, Vermont And Trinidad, Colorado, 1880--1918, Susan L. Richards

Doctoral Dissertations

Between 1880 and 1918, thousands of women in Barre, Vermont and Trinidad, Colorado entered the paid labor force. They worked as boardinghouse keepers, domestic servants, waitresses, laundresses, prostitutes, office workers, saleswomen, telephone operators, business owners, teachers, nurses, doctors, lawyers, artists, musicians, and midwives. By compiling and manuscript census records for 1880, 1900, and 1910, and city directories for the period 1880 to 1918, this study identified 3,634 working women in Barre and 3,886 working women in Trinidad. Cross-checking these names against probate, city, and county court records, marriage and death records, newspapers, local manuscript collections, and oral histories, stories of …

Efforts To Equalize Funding Between Wealthy And Poor School Districts In Maine, New Hampshire, And Vermont, Michael Robert Harris

Doctoral Dissertations

Funding inequities between rich and poor school districts have been the subject of analysis, litigation, and policy decisions across the United States for almost four decades. Pressures for the reform of state educational funding systems have been driven by the national political trend toward equal educational opportunity and by litigation in state courts. The policy responses by states have varied significantly, however, and that variation has characterized the responses in the three New England states of Maine, New Hampshire, and Vermont. Much research nationally has focused on the litigation about school funding, but little study has been given to the …

Carving Out A Sense Of Place: The Making Of The Marble Valley And The Marble City Of Vermont, Michael Louis Austin

Doctoral Dissertations

The making of the Central Valley of Vermont created a sense of identity for the region. Strategically between two Native American confederations, the area was also enmeshed in European settlement to the north, south, east and west. At first conventional farming was the engine of growth in the Central Valley, but the Erie Canal and the rich soil from the Midwest undercut Rutlands agriculture. Rutland switched its economy to sheep. By the 1850s, that too had failed. With the infrastructure of railroads and technology, the rich mineral resources of the region could be exploited and organized on a national scale. …

Improved Swellable Polymer Microspheres For Chemical Sensing, Necati Kaval

Doctoral Dissertations

Derivatized lightly crosslinked polymer microspheres that swell and shrink as a function of pH have been investigated to develop polymeric transduction elements for fiber optic sensors and other sensors. The microspheres were immobilized in hydrogels forming a membrane. The membranes look turbid because of the difference between the refractive index of hydrogel and the refractive index of microspheres. As the microspheres swell as a function of pH, their refractive index decreases approaching the refractive index of the hydrogel. As a result, the turbidity of the membrane decreases. The change in the turbidity of the membrane was monitored by a UV-Vis-NIR …

Nitric Oxide Reduction By Non-Thermal Plasma And Catalysis, Zhongyuan Chen

Doctoral Dissertations

Combustion of fossil fuels produces millions of tons of air pollutants such as NOx and SO2. The high cost and operating difficulties of prevailing selective catalytic reduction (SCR) process are driving R&D efforts towards alternative technologies and modifications to the SCR technology. Non-thermal plasma technique has been found to be one of the most promising technologies for NOx removal.

In the present study, a non-thermal plasma technique in the form of dielectric barrier discharge (DBD) has been extensively investigated for the removal of NOx. The main variables including electrical parameters, chemical compounds and flow conditions are identified and studied in …