Digital Commons Network^™

Computational Investigation Of Stress, Contact Conditions, And Buckling Of Thin-Walled Pipe Liners, Meihuan Zhu

Doctoral Dissertations

Thin walled polymeric liners are often used to rehabilitate deteriorated pipe lines. The host pipes into which these liners are installed are typically assumed to be structurally sound, and the liner is only expected to carry the external pressure exerted by the groundwater. This external pressure will induce creep deformation and radial deflections that may eventually result in collapse of the liner within the host pipe. The aim of this work is use computational modeling to better understand the evolution of conditions leading up to collapse so that improved liner design models can be developed. Emphasis is placed on a …

Perceptions Of Administrators, Counselors, Teachers, And Students Concerning School Safety And Violence In Selected Secondary Schools In North Louisiana, Sharilynn Duckworth-Loche

Doctoral Dissertations

The primary purposes of this study were to determine the perceptions of administrators, counselors, teachers, and students, regarding levels of school safety and violence in selected secondary schools in north Louisiana; the types of violence that had the greatest impact on safety; and strategies that were currently being used to address violence in the schools. The secondary purpose was to determine the differences in perceptions of school safety and violence of administrators, counselors, and teachers by ethnic background, gender and years of experience. A tertiary purpose was to determine the perceptions of students by ethnic background, gender, age, and grade …

Cramer-Rao Bound And Optimal Amplitude Estimator Of Superimposed Sinusoidal Signals With Unknown Frequencies, Shaohui Jia

Doctoral Dissertations

This dissertation addresses optimally estimating the amplitudes of superimposed sinusoidal signals with unknown frequencies. The Cramer-Rao Bound of estimating the amplitudes in white Gaussian noise is given, and the maximum likelihood estimator of the amplitudes in this case is shown to be asymptotically efficient at high signal to noise ratio but finite sample size. Applying the theoretical results to signal resolutions, it is shown that the optimal resolution of multiple signals using a finite sample is given by the maximum likelihood estimator of the amplitudes of signals.

Conscientiousness And The Prediction Of Task Duration: Evidence Of The Role Of Personality In Time Prediction, William Ernest Kelly

Doctoral Dissertations

Accuracy in predicting the duration necessary to complete a task is an important dimension of daily fife. There exists a large degree of variation in an individual's accuracy in predicting task duration. One domain suggested to influence accuracy of predicting duration is that of personality factors and individual differences. Empirical and theoretical links were found in the literature between the personality factor conscientiousness, of the Five Factor Model of Personality, anxiety, and predicting task duration. The purpose of this dissertation was to empirically examine the role of conscientiousness and anxiety in the accurate prediction of task duration. Ninety-five undergraduate students …

Bottom-Up Design Of Artificial Neural Network For Single-Lead Electrocardiogram Beat And Rhythm Classification, Srikanth Thiagarajan

Doctoral Dissertations

Performance improvement in computerized Electrocardiogram (ECG) classification is vital to improve reliability in this life-saving technology. The non-linearly overlapping nature of the ECG classification task prevents the statistical and the syntactic procedures from reaching the maximum performance. A new approach, a neural network-based classification scheme, has been implemented in clinical ECG problems with much success. The focus, however, has been on narrow clinical problem domains and the implementations lacked engineering precision. An optimal utilization of frequency information was missing. This dissertation attempts to improve the accuracy of neural network-based single-lead (lead-II) ECG beat and rhythm classification. A bottom-up approach defined …

Analysis Of The Relationship Between Student Satisfaction And Student Perception Of Interaction In A Compressed Video Setting, Monty E. Sullivan

Doctoral Dissertations

This study used subjects participating in courses offered via the statewide Louisiana Compressed Video Network for the purpose of analyzing the relationship between student perception of interaction and student satisfaction. A correlation analysis was used to determine the relationship between student perception of interaction (sixteen interaction directionalities) and student course satisfaction (including instructional, technical, and overall satisfaction). Data were collected using the Compressed Video Student Perception of Interaction Scale and the Compressed Video Course Student Satisfaction Scale. The nine correlations used to answer the nine research questions resulted in a considerable number of significant correlations. The data generally indicated that …

Characterization Of The Interactions Within The Ccr4 -Not Complex And The Interactions Between Adr1 And Tfiid Components, Yongli Bai

Doctoral Dissertations

The mechanisms of transcriptional regulation are well conserved from yeast to human cells. Most genes are regulated at the transcriptional level, particularly, at the transcription initiation step. In Saccharomyces cerevisiae at least one transcriptional activator, ADR1, and one transcription complex, CCR4-NOT, participate in the activation of the ADH2 gene. The core 1 x 106 dalton CCR4-NOT complex consists of CCR4, CAF1, the five NOT proteins (NOT1-NOT5), and three other uncharacterized proteins. Deletion of NOT3, NOT4, or NOT5 did not affect the association of CCR4 with CAF1 in the gel filtration analysis. In contrast, NOT2 inactivation caused partial destabilization of the …

Modeling The Friction Effects Of Eelgrass On The Tidal Flow In Great Bay, New Hampshire, Safak Nur Erturk

Doctoral Dissertations

In this study the frictional effects of eelgrass (Zostera marina L.) on the tidal flow in Great Bay, NH is modeled using a bottom friction coefficient adjustment approach. A two-dimensional, non-linear, time stepping, finite element model, ADAM is used. ADAM model incorporates two-dimensional wave physics, with a porous medium beneath the sediment surface to simulate wetting and drying process on the tidal flats. The effectiveness of ADAM model in simulating the tidal flow in Great Bay with wetting and drying on the tidal flats is verified. The model is calibrated by adjusting the bottom friction coefficient for the M2, M2S2 …

Internet Use And Its Relation To Mental And Physical Health Among Older Adults, Michael Anthony Mangan

Doctoral Dissertations

This exploratory study examined relations between frequency of Internet use among adults 65 and older and perceptions of social support and personal control. Additionally, standard multiple regression procedures were employed to assess the usefulness of frequency of Internet use, perceived social support, and perceived control as predictors of mental and physical health. Results were that frequency of Internet use was uncorrelated with perceptions of social support and personal control and was not predictive of mental or physical health. Perceived social support and perceived control emerged as predictors of mental and physical health. Recommendations for future research that refines measurement of …

The Effects Of Ultraviolet Radiation, Highway Contamination, And Synergism Of The Two On Spotted Salamander Embryos, Sarah Letitia Turtle

Doctoral Dissertations

In this study, I examined the effects of ultraviolet radiation, highway contamination and a synergism of both factors on the spotted salamander, Ambystoma maculatum embryos in field and laboratory experiments. There are numerous reports of amphibian population declines from around the world. There are several possible factors causing the decline, including, habitat loss, environmental pollution, disease, and ultraviolet B radiation (UVB, 290--320 nm). Results of studies conducted to date seem to indicate that the impacts of these factors vary greatly among species and across geography. Amphibians have unique characteristics and life histories that make them more vulnerable to changes in …

Modeling Plant-Soil-Atmosphere Carbon Dioxide Exchange Using Optimality Principles, Kevin Patrick Tu

Doctoral Dissertations

The exchange of carbon dioxide (CO2) between terrestrial ecosystems and the atmosphere plays a central role in the ecology of the biosphere and the climate system. Towards quantification of ecosystem-atmosphere CO 2 exchange, a generalized model of plant-soil-atmosphere CO2 exchange (OPTICAL) was described and evaluated using eddy covariance measurements of net ecosystem exchange of CO2 (NEE) in arctic, boreal, temperate, and tropical landscapes. The model requires no calibration and is based on theories of plant resource optimization and plant-soil nutrient feedbacks. The model predicts canopy photosynthetic capacity (Pcmax), canopy photosynthesis (P c), plant respiration (Rp), and soil heterotrophic respiration (RH). …

Lifers: A Study Of At -Risk Adolescent Readers, Pamela Nottage Mueller

Doctoral Dissertations

In this study I put a face and voice to the at-risk adolescent reader. No strangers to failure, these are students who by and large have struggled with reading their entire educational lives but who for whatever reason have been unable to escape the cycle of frustration in which they find themselves caught. These are students who have a great deal to say but who until now have had no forum in which to say it. These are students who deserve to be heard.

For my primary source of data, I utilized Seidman's phenomenological approach to interviewing, conducting a series …

A Statistical Study Of The Dependence Of The Integrated Wave Power Of Geomagnetic Pulsations Between 01 Hz And 10 Hz Upon The Solar Wind Dynamic Pressure, Cristian C. Cocheci

Doctoral Dissertations

We present a statistical study of the influence of the solar wind dynamic pressure on the power of geomagnetic pulsations in the frequency range of 0.1 to 1.0 Hz (around the superposition of the Pc1 and Pc1--2 frequency ranges). The solar wind parameters are calculated using data from the Solar Wind Experiment and from the Magnetic Field Instrument on board the WIND spacecraft. Using ground data from the Antarctic AGO arrays and northern hemisphere stations we have compared the integrated power of pulsations between 0.1 and 1.0 Hz with the variations of the solar wind dynamic pressure, on scales of …

X- And Gamma -Ray Observations Of The 15 November 1991 Solar Flare, Martina Belz Arndt

Doctoral Dissertations

This dissertation expands the current understanding of the 15 November 1991 X1.5 solar flare. This flare was a well observed event in radio to gamma-ray energies and is the first gamma-ray flare to be extensively studied with the benefit of detailed soft and hard X-ray images. In this work, we add data from all four instruments on the Compton Gamma Ray Observatory (CGRO), spanning 20 keV--300 MeV. From these data we determined that the accelerated electron spectrum above 170 keV is best fit with a power law with a spectral index gamma ≈ -4.6. We determined that the accelerated proton …

Finite Element Modeling Of Tidal Flow And Bed -Load Transport In The Great Bay Estuarine System, New Hampshire, Ata Bilgili

Doctoral Dissertations

Current, sea level and bed-load transport are investigated in the Great Bay Estuary, New Hampshire---a shallow, well-mixed system with low freshwater input. Main channel tidal currents are over 2 m/sec, and its dynamic balance is dominated by the pressure gradient and bottom friction. Current and sea level forced by the M2, M4, M6 tides at the estuary mouth are simulated by two numerical models---a three-dimensional, harmonic model that solves the linearized shallow water equations (FUNDY5); and a vertically averaged, time stepping, non-linear model (ADAM). ADAM makes use of a kinematic assumption (that is, the local and advective accelerations are neglected) …

Carbon And Nitrogen Dynamics Of Northeastern United States Forests In Response To Environmental Stress: Measurements And Models At Local To Regional Scales, Scott V. Ollinger

Doctoral Dissertations

This thesis stems from several ongoing efforts to characterize patterns of productivity and nitrogen cycling in northeastern US forests and to address the effects of nitrogen deposition, tropospheric ozone and rising atmospheric CO2. The work reported on involves two related projects; (1) an ecosystem model analysis that integrates physiological and biogeochemical processes with important environmental variables across the northeast region and (2) a field and remote sensing analysis that examines landscape-level patterns of forest biogeochemistry in the White Mountains of New Hampshire.

Chapter 1 presents a regional analysis of forest productivity using the PnET forest ecosystem model and discusses the …

Exploring Other Worlds: Margaret Fox, Elisha Kane, And The Antebellum Culture Of Curiosity, David Alexander Chapin

Doctoral Dissertations

Antebellum Americans had a strong interest in the unknown, which manifested itself simultaneously in highbrow, middlebrow, and lowbrow culture. Venues such as scientific institutions, lyceums, lecture halls, the "penny-press," and the dime-museum all catered to American curiosity. Exploring Other Worlds examines this "culture of curiosity," arguing that curiosity was a defining trait of antebellum America, transcending many of the boundaries we often associate with the era. Curiosity promoted intellectual interest in science, but it also led to the sensationalism of modern commercial popular culture.

The inter-related lives of Elisha Kane and Margaret Fox demonstrate this thesis. Kane was America's first …

Improvements Of X-Band And Q-Band Epr /Endor Spectrometers Studies Of Ferritin Iron Nitrosyl And Copper Cis, Cis-1,3,5-Triaminocyclohexane Chloride Complexes, And The Application Of Q -Band Epr To The Dating Of Fossil Teeth, Junlong Shao

Doctoral Dissertations

Several modifications were made on a Varian Q-band EPR/ENDOR spectrometer, including the installation of a microwave amplifier in the E110 bridge, design and assembly of a new cavity coupler, addition of frequency counting capability, as well as other useful minor changes. The performance of the spectrometer was improved in signal-to-noise ratio, convenience of tuning and operation and accuracy of g-value and hyperfine coupling measurements. The signal-to-noise ratio was increased by a factor of six.

Improvements were also achieved with our X-band EPR/ENDOR spectrometer by design and assembly of a new printed ENDOR coil for use in a TE104 rectangular cavity. …

The Perceived Effects Of State -Mandated Testing In New Hampshire, Stephen A. Kossakoski

Doctoral Dissertations

The purposes of this study were: (1) to examine the perceptions of third grade teachers in the state of New Hampshire concerning the state's mandated testing program, and (2) to determine if there was a relationship between teachers' perceptions and their schools' socioeconomic status. The survey instrument designed for this study contained 61 closed response Likert scale items that measured teachers' perceptions regarding changes in curriculum and instruction, sources of pressure to improve test scores, and attitude toward the third grade test. A stratified random sample of 310 third grade teachers was selected to participate in this study. The percentage …

Source, Production And Export Of Dissolved Organic Carbon And Nitrogen, Jacqueline A. Aitkenhead-Peterson

Doctoral Dissertations

The purpose of this research was to quantify the major sources of dissolved organic carbon (DOC) and nitrogen (DON) in forest soils and ascertain mechanisms for their production and export to surface waters. To quantify the source of DOC we made use of the on-going litter manipulation study (DIRT) at Harvard Forest, Massachusetts. The organic horizon supplies 74% of DOC to bulk soil solution, 12% is supplied by leaf litter, and 13% from root exudate and decay. In plots with no inputs, DON concentrations were 9% higher than the control plots. When either roots or litter were excluded, DON concentrations …

Diels -Alder Reactions Between Fullerene[60] And Various Pentacenes, James Mack Ii.

Doctoral Dissertations

The reaction of fullerene[60] with pentacene and various 6,13-disubstituted pentacenes has been studied and the formation of cis-bisfullerene[60] adducts has been achieved. The reaction of fullerene[60] with pentacene was studied with the goal of preparing cis-1 and trans-2 bisfullerene[60] adducts. Instead, the solution phase Diels-Alder reaction between fullerene[60] and pentacene yields a C 2v symmetric monoadduct, 3, in 59% yield.*.

Semi-empirical PM3 calculations suggest that fullerene[60] should react favorably with 6,13-disubstituted pentacenes such that molecules similar to 1 and 2 would form. Several 6,13-disubstituted pentacenes were synthesized and subsequently reacted with fullerene[60] resulting in the formation of various cis-bisfullerene[60] adducts …

On The Quest For Economic *Growth And Development: The Developing World, The Failures Based On Physical Capital Accumulation And International Rescuers, And The Emergence Of A New Perspective, Augusto Marcos Carvalho De. Sena

Doctoral Dissertations

This thesis critically reviews the literature on economic growth and development focusing on the interconnections, strengthens and weaknesses of both branches. Questions arise if growth and development models have been of any relevance to developing countries. The experience with International Financial Institutions (IFIs), such as the World Bank and the IMF, is also focused on to corroborate the assertion that the alternative answer based on stabilization-structural adjustments, sponsored by these agencies, has not been useful as a reasonable way to solve the most prominent problems of developing countries. It is concluded that both the World Bank and the IMF recipes …

Piety, Politeness, And Power: Formation Of A Newtonian Culture In New England, 1727--1779, Frances Herman Lord

Doctoral Dissertations

This dissertation explores how men and women deployed the mathematical and experimental science of Isaac Newton and the new science based upon his work as the framework for a "Newtonian culture" in New England between 1727 and 1779, which established our modern view of the natural world and the authority of science. Their endeavors often involved co-opting the authority, and the cachet, of Newton's name and redirecting it toward new ends that involved both the affirmation and challenge of prevalent cultural, religious, and social values. This study examines the uses of Newtonian natural philosophy within the context of the cultural …

Rational Design And Syntheses Of 4-Phosphino-Catechol Hybrid Ligands For Mixed -Metal Clusters, Xiankai Sun

Doctoral Dissertations

Based on the concepts of Incommensurate Symmetry-Driven Cluster Formation, an approach to mixed-metal cluster formation has been proposed and realized by using the incommensurate symmetry requirements at two different metal centers bridged by a hybrid ligand. Critical to this strategy is the proper design and synthesis of hybrid ligands with coordination sites selective towards each metal. 4-Phosphino-Catechol hybrid ligands with both hard catecholate and soft phosphine donor sites have been shown to serve such a role. Three new ligands; 4-PPh2-Catechol (H2L), 4-PH2-Catechol (H2 2) and 4-P(CH2OH)2-Catechol (H23) as well as their precursors 4-PPh2-Veratrole and 4-PH2-Veratrole have been synthesized and characterized. …

Multipoint Measurements Of Large Electric Fields And Shears In The Auroral Zone, David Pietrowski

Doctoral Dissertations

This work presents results from the Auroral Turbulence II (AT II) sounding rocket launched from the Poker Flat Research Range, near Fairbanks, Alaska, on February 11, 1997. The rocket consisted of three identically instrumented payloads that reached an apogee of 550 km and flew through several arc structures in a pre-midnight auroral breakup. Three payload measurements were desired to separate the temporal from spatial aspects of auroral forms, and to investigate three dimensional flows and fields that cannot be resolved using traditional single point measurements. The focus of this study has been in the structure and changes in the dc …

Nitrated Poly(4 -Hydroxystyrene) Microspheres For Optical Ph And Potassium Ion Sensing Based On Turbidity Changes Accompanying Polymer Sweller, Hongming Wang

Doctoral Dissertations

Porous poly(4-acetoxystyrene) swellable microspheres with diameters approximately 1∼2 mum were prepared by seeded emulsion polymerization. Toluene was used as the porogenic solvent and divinylbenzene was used as the crosslinker. The seed particles with diameters approximately 0.5∼1 mum were prepared by dispersion polymerization without adding porogenic solvent and crosslinker. Functionality was introduced by two derivatization reactions, hydrolysis and nitration, to form nitrated poly(4-hydroxystyrene). These polymer microspheres swell at high pH due to the deprotonation of the hydroxyl group on the polymer backbone. Swelling is accompanied by an increase in water content which causes the polymer refractive index to decrease. These microspheres, …

Transition Metal Complexes Of Novel Ligands Derived From The Cis,Cis-1,3,5-Triaminocyclohexane (Tach) Framework: Structural And Biological Studies, Gyungse Park

Doctoral Dissertations

Transition and Group IIB metal complexes of novel ligands derived from cis,cis-1,3,5-triaminocyclohexane (tach) were prepared for structural and biological activity study. Copper(II) complexes of N,N ',N″-trialkylated derivatives of tach [Cu(tach-R3)Cl2] (R = Me, Et, Pr, furanyl, and thiophenyl) were prepared from CuCl2 in MeOH or MeOH/Et2O solvent. The structures of [Cu(tach-R3)Cl2] in the solid and solution (aqueous and methanolic) states were extensively studied by UV-vis and EPR spectroscopies and were consistent to X-ray structure of [Cu(tach-Et 3)Br0.8Cl1.2] which reveals a slightly distorted square-based pyramidal geometry. Displacement of halide ions with water molecules in aqueous media was observed by the band …

Biodiversity And Phytogeography Of Bolivia's Wetland Flora, Nur Paul Ritter

Doctoral Dissertations

The composition, diversity, and phytogeographic affinities of the vascular flora of Bolivia's wetlands were examined and compared with wetland floras from the other Neotropical countries and the New World Temperate region. Forty-six wetlands distributed throughout Bolivia and ranging in elevation from 90 in to >4400 m were established as study sites. Regional and national wetland floras were compiled from field research, the literature, herbarium specimens, and available databases.

Two thousand and sixty species in 149 families and 666 genera were identified as associated with wetlands in Mesoamerica and tropical and subtropical South America. Of these, 1026 species in 126 families …

Sustainable Living: A Case Study Of Nuns And Their Beliefs, Attitudes And Practices, Mary Catherine Clipson

Doctoral Dissertations

This dissertation is a case study of monastic nuns in the context of sustainable living. The essential core question is: How has the way of life of nuns in a monastic community been a sustaining one. There are six chapters: Introduction, Historical Context and Overview, Methodology, The Context and People of The Priory of Our Lady of Peace, Analysis of Data, and Synthesis and Interpretation.

The methodology used to get at the case study is, primarily, participant observation and individual interviews with twelve (of the eighteen) nuns; and secondarily, an ecological assessment of the community and buildings, and a questionnaire …

Remote Sensing Of Forest Damage In The Czech Republic Using Hyperspectral Methods, Petya K. Entcheva

Doctoral Dissertations

The current study assesses the potential of hyperspectral data for monitoring the initial stages of damage in Norway spruce forests characterized by subtle changes in foliar chlorophyll and chemistry. Both field and airborne high spectral resolution reflectance measurements were obtained for selected study sites in the Krusne hory, Czech Republic.

High spectral resolution airborne canopy data and field foliar samples were acquired simultaneously in August 1998 for a total of 51 study sites within the Krusne hory. The sites were selected to represent a full range of damage conditions in even-aged Norway spruce (Picea abies (L.) Karst) stands located between …