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Analysis And Design Considerations Of A High-Power Density, Dual Air Gap, Axial-Field, Brushless, Permanent Magnet Motor, Chahee Peter Cho

Doctoral Dissertations

Until recently, brush dc motors have been the dominant drive system because they provide easily controlled motor speed over a wide range, rapid acceleration and deceleration, convenient control of position, and lower product cost. Despite these capabilities, the brush dc motor configuration does not satisfy the design requirements for the U.S. Navy's underwater propulsion applications.

Technical advances in rare-earth permanent magnet materials, in high-power semiconductor transistor technology, and in various rotor position-sensing devices have made using brushless permanent magnet motors a viable alternative. This research investigates brushless permanent magnet motor technology, studying the merits of dual-air gap, axial-field, brushless, permanent …

Literacy Portfolios: Considering Issues Of Purpose, Power, And Potential, Carol A. Wilcox

Doctoral Dissertations

In this study, I examine the complexities of incorporating literacy portfolios into an elementary school classroom: the purposes for using portfolios, issues of ownership and audience, the nature of children's evaluative decisions, adults' responsibilities in children's development as evaluators, and the institutional pressures impacting adults' abilities to incorporate children's voices into existing evaluative practices.

The study was conducted in a third grade classroom where children read and wrote in a variety of genres for authentic purposes and audiences every day. Although the study cannot be described as an ethnography in the strictest sense, research methodology is drawn from that discipline. …

Comparison Of Chlorine And Chlorine Dioxide As Disinfectants For Surface Waters, Kristen S. Tilton

Doctoral Dissertations

Safe supplies of drinking water free of pathogenic agents such as viruses and protozoa are essential for humankind. The evaluation of current treatment practices for the removal of pathogens has become increasingly important with the occurrence of waterborne disease outbreaks. Shortcomings associated with chlorine have prompted the need to assess alternative disinfectants.

The overall objective of this research is to compare chlorine and chlorine dioxide as disinfectants for surface waters using Giardia muris cysts, bacteriophage MS2, total and fecal coliforms, and heterotrophic bacteria. Concentration x time (CT) values for the inactivation of Giardia muris cysts and MS2 bacteriophage as a …

Extensions Of Bialgebras And Their Cohomological Description, Mark Lloyd Bochert

Doctoral Dissertations

This paper develops the theory of crossed product Hopf algebras of pairs of arbitrary Hopf algebras. The theory generalizes the crossed products of (Maj90), the Abelian crossed products of (Hof94) and the crossed product algebras of (BCM86). First, conditions are given on the structures involved that are shown to be equivalent to the existence of the crossed product. Next, a bisimplicial object is found that gives a cohomological description of the conditions. Cleft extensions of pairs of arbitrary Hopf algebras are then defined. These generalize the cleft extension algebras of (Swe68) and the Abelian cleft extensions of (By93); they are …

A Comparative Study Of The Ecology Of Smooth Flounder, Pleuronectes Putnami, And Winter Flounder, Pleuronectes Americanus, From Great Bay Estuary, New Hampshire, Michael Patrick Armstrong

Doctoral Dissertations

Smooth flounder, Pleuronectes putnami, and winter flounder, Pleuronectes americanus, co-occur in estuaries along the east coast of North America from Labrador to Massachusetts. Results of a three year sampling program indicated that the two species were partially segregated along salinity and depth gradients in upper Great Bay Estuary, New Hampshire. Along the salinity gradient, smooth flounder were most abundant at the oligo-mesohaline riverine habitat while winter flounder were most abundant at the meso-polyhaline open bay habitat. Both species exhibited a generalized up-river movement with seasonally increasing salinity. Smooth flounder showed ontogenetic changes in distribution along the depth gradient, with the …

Nucleotide And Energy Metabolism During Visual Transduction In Electropermeabilized Rod Outer Segments, Vincent J. Coccia

Doctoral Dissertations

Cyclic GMP and calcium are known to be messengers involved with visual transduction in vertebrate rod photoreceptor outer segments (ROS). However, it has been difficult to study the interrelationship of the calcium and cGMP signaling pathways using biochemical methods. An electropermeabilized rod outer segment (EP-ROS) preparation has been developed to examine these problems.

Square-wave electric field pulses were used to generate permanent disruptions in the plasma membrane of ROS. This treatment also permeabilized the disk membranes within the organelle. EP-ROS retain the characteristic morphology of osmotically intact ROS at the light microscopic level, but are permeable to low molecular weight …

"Wherein Lies Personal Identity": The Reception Of Locke And Richardson And The Language Of Self In The Letters And Journals Of Exceptional Eighteenth Century American Women, Carolann O'Malley Davis

Doctoral Dissertations

This dissertation adds a new chapter to the history of the social revolution that accompanied the American Revolution, specifically the revolt against patriarchalism. It is my contention that exceptional women initiated a private revolution to gain recognition of a new personal identity. This private revolution led to the rejection of the system of private government of man over woman, patriarchalism.

I identified seven women, Eliza Lucas Pinckney, Abigail Adams, Esther Edwards Burr, Mercy Otis Warren, Eliza Southgate Bowne, Anne Willing Bingham and Anne Home Shippen, who were especially representative of a network of women who developed a self-consciousness. For these …

Parametric Instabilities Of Alfven Waves In The Solar Wind, Venku Babu Jayanti

Doctoral Dissertations

We consider the stability of a circularly-polarized Alfven wave (the pump wave) propagating along a uniform ambient magnetic field B$\sb{\rm O}$. The system is linearly perturbed to study the stability of the Alfven wave. The perturbations are also assumed to propagate along the ambient field. Four different problems are addressed relating to the stability of the Alfven wave. The first involves using Floquet's theorem to obtain a dispersion relation for studying the stability. The result is a hierarchy of dispersion relations. However, all the dispersion relations are found to be equivalent. This technique showed that some results of other workers …

The Art Of Living': The Aesthetics Of Everyday Life In Dorothy Canfield Fisher's Novels, Anne Marie Downey

Doctoral Dissertations

In 1924, Dorothy Canfield Fisher (1879-1958) wrote, "I have always conceived of everyday life as needing very much the sort of constant effort at composition--that is shapeliness, elimination of unnecessary details, choice of details--as any other work of art." This quotation is the epigraph to my study of five of Fisher's early novels because it reveals a central theme of her fiction: that art is the creation of a daily life that successfully negotiates the "problems of living" (Fisher's phrase) that plague modern America. The five novels that I analyze--The Squirrel-Cage (1912), The Bent Twig (1915), The Brimming Cup (1921), …

Orbit-Reflexivity, Michael James Mchugh

Doctoral Dissertations

Suppose $H$ is a separable, infinite dimensional Hilbert space and $T$ and $S$ are bounded linear transformations on $H$. Suppose that if $Sx\in\{x, ,Tx ,T\sp2x,...\}\sp{-}$ for every $x$ implies that $S\in\{1, T, T\sp2,...\}\sp{-SOT}$ then $T$ is orbit-reflexive. Many operators are proven to be orbit-reflexive, including analytic Toeplitz operators and subnormal operators with cyclic vectors.

Suppose that if $Sx\in\{\gamma x : x\in H, \gamma\in\doubc\}\sp{-}$ for every $x$, implies that $S\in\{\gamma T\sp{n} : n\ge0, \lambda\in\doubc\}\sp{-SOT}$ then $T$ is $\doubc$-orbit-reflexive. Many operators are shown to be $\doubc$-orbit-reflexive. $\doubc$-orbit-reflexivity is shown to be the same as reflexivity for algebraic operators.

The Stability Of Flow Over An Elastic Boundary, Paul Joseph Schall

Doctoral Dissertations

Experiments with printing presses show unusual behavior when a fluid flows between rubber and rigid roller. For better understanding of this behavior, three problems which address the stability near fluid interfaces are considered. First, the stability of a viscous flow between a rigid boundary and an elastic layer is studied. Of particular interest are cases with large Froude number modeling rotational effect, and cases with an elastic layer thin as compared to the depth of the fluid. Linear stability is considered using a spectral method. Second, the inviscid flow between a rigid boundary and an elastic layer is studied. Two …

Forest Floor Leachate Biogeochemistry And Decomposition Dynamics, William S. Currie

Doctoral Dissertations

Forest floor biogeochemistry was studied in combined field and modeling research in ecosystems representative of forests of the Northeastern U.S. The field study, conducted at the Harvard Forest, MA, focused on changes to organic and inorganic chemistry of forest-floor leachate under experimentally elevated N inputs meant to simulate effects of acid deposition in the region.

Concentrations of dissolved organic carbon and nitrogen (DOC and DON) increased substantially in N treatments in the first year of the study. I attributed this to an increase in production of soluble organics in the forest floor due to an interaction between increased N availability …

Locations And Spectra Of Cosmic Gamma-Ray Bursts, Richard Marc Kippen

Doctoral Dissertations

The COMPTEL instrument aboard the Compton Gamma Ray Observatory is used to study the phenomena of cosmic gamma-ray bursts. Three years of observations from April 1991 through April 1994 reveal 18 significant gamma-ray burst detections. The locations (mean accuracy $\sim$1$\sp\circ$) and spectra (0.75-30 MeV) of these bursts are measured and are used to investigate the spatial distribution of burst sources and the characteristics of their emission at MeV energies. Rapidly determined COMPTEL burst localizations obtained through direct imaging are used to search for fading burst counterpart emission in a coordinated effort with ground-based optical and radio telescopes.

The COMPTEL burst …

Autobiographical Understandings: The Evolution Of A Teaching Self, Joann Portalupi

Doctoral Dissertations

In this study the author uses autobiographical method to explore specific questions about teacher development: How is a teacher identity constructed; What constitutes the teaching self? In addition this study seeks to consider the potential uses of autobiography as a tool in teacher education.

Part One, "A Quiver of Truths," is an autobiographical text in which the author explores issues of her own development as a teacher to reveal its broad roots in a wide expanse of life experiences, specifically the familial, cultural, and historical influences as well as broader issues of human development. Any attempt to make meaning out …

Extending The National Council Of Teachers Of Mathematics' "Recognizing And Recording Reform In Mathematics Education" Documentation Project Through Cross-Case Analyses, Loren Phaffle Johnson

Doctoral Dissertations

The primary emphasis of this study was to broaden the understanding of data collected in the National Council of Teachers of Mathematics' (NCTM) Recognizing and Recording Reform in Mathematics Education (R$\sp3$M) project in order to more fully clarify the processes by which reform in mathematics education was occurring across five high school sites. A secondary emphasis was to develop a model of doing cross-case analyses and identifying those methodological elements and linkages that could be applied generally in large-scale studies of this sort.

R$\sp3$M documenters obtained data that resulted from interviews of mathematics teachers, administrators, and students; classroom observations; and …

The Nation-State And Its Ideology: A Study Of School Children's Views Of Nationalism, Politics, And Enmity, Linda June Olson

Doctoral Dissertations

This dissertation explores the reproduction and ideological legitimization of the nation-state in the eyes of successive generations. There are two components to this study. The first is a socio-historical analysis of the formation of nation-state ideology, a formation which seems to necessitate creation of "in-groups" and "out-groups." It is a socio-historical analysis of victimization, of the tendency to justify colonialism, expansionism, imperialism, and brutality to outsiders.

The second component of this study is concerned with how the ideology of the nation-state regarding nationalism, patriotism, and especially classification of enemy groups, is reproduced and legitimized for future generations. For this purpose, …

The Impact On The Family Of Long-Term Caregiving In The Home, Holley Spangler Gimpel

Doctoral Dissertations

Families provide care in ever-increasing numbers for chronically and terminally ill family members. Previous empirical measurement of caregiver strain was generally limited to one type of care recipient population (e.g., elderly), with samples drawn primarily from metropolitan centers (and often support groups), and confined to individual assessment (i.e., primary caregiver), with outcomes of depression and anxiety. This study sought to address some of the research gaps in previous research.

In-depth caregiver and family-member interviews using both quantitative and qualitative research methods were conducted during a 10-month period throughout an entire state, composed mostly of rural and small-town populations. Examination was …

Differentiating Between Delay Dependent And Delay Independent Deficits Following Medial Thalamic Lesions And Prefrontal Cortical Lesions In The Rat, Alexander Alden Stevens

Doctoral Dissertations

Twenty-four male rats were pretrained on a two-choice, auditory match to position (AMTP) task and randomly assigned to one of three treatment groups: radio-frequency lesions of either the medial wall (MW) of prefrontal cortex; lesions of the lateral internal medullary lamina site (LIML) of thalamus; or sham surgical control (CON).

Both lesion groups exhibited significant impairment on initial post-surgical testing of discrimination trials in the AMTP task. However, the MW group showed partial recovery with extensive retraining. In contrast, the LIML lesion group remained impaired throughout post-surgical discrimination testing. Neither the MW or the LIML group showed signs of more …

A Study Of The Synthesis Of 2,2',4,4'-(4,4'-Bioxazoles)-5,5'(4h,4'H)-Diones, Their Isomers, And The Products Of Nucleophilic Ring Openings, Daniel Francis Gloster

Doctoral Dissertations

The purpose of this research was to investigate routes towards the synthesis of $\alpha,\alpha\sp\prime$-dehydrodimeric amino acids. This dissertation describes various methods of effecting dehydrodimerization of bioxazoles. Bioxazoles are good candidates to serve as precursors to $\alpha\,\alpha\sp\prime$-dehydrodimeric amino acids, because they are $\alpha,\alpha\sp\prime$-dehydrodimeric amino acid derivatives. This dissertation describes the synthesis and characterization of d,l and meso 4,4$\sp\prime$-bioxazoles as well as, 2,4$\sp\prime$-bioxazoles.

A variety of bioxazoles were synthesized and some were subjected to nucleophilic ring opening. It had been reported that nucleophilic attack at the bioxazole ring caused the dehydrodimeric carbon-carbon bond to be cleaved. Results of this work indicate that …

Experimental And Numerical Studies On Pattern Formation In Electrochemical Deposition, Zhenqiu Liu

Doctoral Dissertations

An experimental and theoretical investigation on pattern formation in electrochemical deposition from copper and zinc binary sulfate electrolyte in two dimensional cells was carried out in this study. Aggregates were produced by electrochemical deposition. An interferometric setup was developed to measure the concentration boundary layer around the aggregates produced during growth.

Convection is observed during electrodeposition from binary sulfate solution of zinc and copper with the concentration of 0.04M and higher in horizontal cells. The theoretical and experimental investigation indicates that natural convection is much stronger in a horizontal cell than that in a vertical cell. Channel growth is observed …

Reactions Of A Dimolybdenum Cage Complex With Phosphorus And Nitrogen Nucleophiles And The Synthesis And Reactions Of Heterobimetallic Cages, Haiying Yang

Doctoral Dissertations

The reactions of the dimolybdenum cage complex Mo(CO)$\sb4$-$\rm \lbrack\sp{i}Pr\sb2NPO\rbrack\sb4Mo(CO)\sb4\sp{*}$ with phosphorus and nitrogen nucleophiles were studied. This dimolybdenum cage complex reacted with tertiary phosphines of the type PPh$\sb2$R (R = Ph, Me, H) in refluxing toluene. In each case, incorporation of a single phosphine led to the loss of three carbonyls to form orange complexes of the type $\rm Mo(CO)\sb3\lbrack \sp{i}Pr\sb2NPO\rbrack \sb4Mo(CO)\sb2PPh\sb2R$(2, 3, 4). The X-ray molecular structure of 2 has been determined. This revealed that a cage P-O-P bond has been cleaved near the substitution site with the resulting phosphinito oxygen replacing a second CO. Additionally, the phosphido group …

Professionalization Of Occupational Therapists: A Study Of Emergent Identities, Lou Ann Sooy Griswold

Doctoral Dissertations

The unprecedented demand for occupational therapists and resulting growth in student numbers necessitates the need to understand how students acquire professional ideology, learn expected role behavior, and identify themselves as occupational therapists. This ethnographic study includes interview data from a series of three interviews with 37 trainees, from freshmen to the first year of employment, who had been or were in the occupational therapy program at Worcester State College, in central Massachusetts. Students included women and men who were preparing for either a first or second career. Interviews with six academic faculty and seven fieldwork supervisors in three areas of …

Evaluation Of Polymer Coated Attenuated Total Reflection (Atr) Elements For The Analysis Of Organic Compounds In Aqueous Solution, Marc C. Ertan-Lamontagne

Doctoral Dissertations

A significant limitation of ATR/FTIR for the analysis of aqueous solutions is the relatively high bulk concentration of analyte required. One approach to improving the detection of an analyte is to incorporate a thin polymeric phase at the surface of the ATR element. The purpose of the polymeric phase is to extract the analyte of interest and concentrate it within the depth of penetration of the evanescent wave. Utilizing a very high molecular weight poly(vinyl chloride) phase the time necessary to reach equilibrium for a 0.05% (v/v) nitrobenzene in a 1.5% (w/v) methanol/water solution was over 60 minutes. A study …

Beyond Note Cards: Rethinking The Freshman Research Paper, Bruce Ballenger

Doctoral Dissertations

Ever since its introduction as an assignment in composition textbooks in the 1920s, the freshman research paper has confounded students and discouraged their instructors. Yet the research paper remains a largely static fixture in most first-year writing courses. What accounts for assignment's persistence, despite the long history of complaint? What are the aims of the freshman research paper, and how well do students understand its purpose? Why do they struggle with the genre? How might it be reconceived?

Using extensive interviews with students and a close examination of student papers, I argue here that the conventional freshman research paper is …

The Availability Of Spatial Information In A Situation Model, Christopher Mark Hakala

Doctoral Dissertations

Four experiments were conducted to determine the availability of spatial information from a situation model. In Experiment 1, participants were told to either focus on spatial information while reading the texts or to read for comprehension. At the end of each text, participants were presented with a probe word to name. The probe word was either spatially associated or dissociated with the final spatial location of the main character. Participants named the spatial probe more quickly only when told to focus on spatial information. Experiment 2 used reading time as a dependent measure to determine ease of integration of spatially …

Making A Place For Poetry: Response In An Adult Writing Group, Andrea Luna

Doctoral Dissertations

This dissertation examines how writers respond to other writer's work in the context of a community poetry group. A qualitative study of the poetry group, including participant-observation and tape recording of group meetings, analysis of conversation during meetings, collection of documents, and open-ended interviewing of participants, was undertaken over a period of ten months. Through narrative analysis of the data, one of the primary units of which is the single poem plus the group's response to that poem, the author attempted to create a credible interpretation of the activities and conversations of the group which addresses the question of what …

Part I Synthesis And Study Of Cyclic Sulfamates Part Ii Investigation Of Endocyclic Nucleophilic Substitution At Tetracoordinate Sulfur(Vi), Martin George Kociolek

Doctoral Dissertations

Part I. 5-Nitro-N-(p-toluenesulfonyl)-1,2,3-benzoxathiazole-2,2-dioxide was synthesized and reacted with various nucleophiles. Nitrogen nucleophiles attacked the exocyclic sulfur atom resulting in cleavage of the tosyl group. This is due in part to the acidity of the parent benzoxathiazole ring. A series of substituted N-H-1,2,3-benzoxathiazole-2,2-dioxides were synthesized and their pK$\sb{\rm a}$ values were determined. An ab initio study was also undertaken on a simple sulfamate model in order to determine the origin of the increased acidity of the cyclic sulfamates, compared to their acyclic analogues. It was determined that the increased acidity was directly affected by the conformation of the neighboring heteroatoms. This …

Information Technology, Employee Participation And The De-Skilling Thesis, Jay Charles Lacke

Doctoral Dissertations

While the de-skilling of work may involve many facets, including task simplification and the degradation of manual skills, this dissertation focuses specifically on the loss of control by workers over the organization and direction ("conception") of their own work. This focus is consistent with Harry Braverman's (1974) seminal argument that the "pivot" of capitalist management, and the core of the de-skilling thesis, is the separation of the conception of work from its execution.

Employee participation strategies whereby workers exercise discretion over the organization and conduct of work are contrary to the de-skilling thesis. But their existence is compatible with post-Braverman …

Radiatively Active Trace Gas Emissions From Waste Management Systems, Peter Matthew Czepiel

Doctoral Dissertations

Current waste management practices present significant potential for emissions of radiatively active trace gases to the atmosphere. This dissertation describes the quantitative assessment of nitrous oxide (N$\sb2$O) emissions from liquid waste and residuals treatment, emissions of methane (CH$\sb4$) from landfills, and the effects of microbial oxidation on landfill CH$\sb4$ emissions.

N$\sb2$O emissions were measured from liquid treatment process at a wastewater treatment plant where the highest emissions occurred during secondary aeration. Emission factors derived from the measurements included 3.2 g N$\sb2$O person$\sp{-1}$ year$\sp{-1}$ and $1.6\times10\sp{-6}$ g N$\sb2$O (liter wastewater$\sp{-1}$). The potential for N$\sb2$O emissions from the composting of the residual …

Bodies Of Life: Shaker Literacies And Literature, Etta Maureen Madden

Doctoral Dissertations

I examine the roles of literacy and literature among the Shakers from the opening of "Mother" Ann Lee's testimony in 1780 through the early twentieth century to propose that the sect persistently resisted and revised "the world's" literacies. I assert that multiple kinds of reading and writing acts reinforce the beliefs of individuals and the church as a whole, and I argue that the increase in literary acts which appear to contribute to individualism and fragmentation of the institution actually allows Believers to revise their theology so that they see their sect as continuing to grow rather than declining.

In …