Digital Commons Network^™

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 …

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 …

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 …

Experiments On Transient Natural Convection In Inclined Enclosures Using Calibrated Multichannel Electronic Interferometry And Digital Particle Image Velocimetry, Timothy David Upton

Doctoral Dissertations

Simultaneous quantitative measurements are made of both the temperature and velocity fields for two-dimensional transient natural convection in an inclined rectangular enclosure. The fluid in the enclosure is initially stationary and isothermal. The transient boundary conditions are initiated by instantaneously heating and cooling two opposing walls. All other walls are insulated and nonconducting. The evolution of the flow to steady state is determined for a Prandtl number of 6.38, a Rayleigh number of 1.5 $\times$ 10$\sp5$, and an aspect ratio of 1.0, at angles of inclination of $\pi$/4, $\pi$/2, and 3$\pi$/4. The temperature is measured using calibrated multichannel electronic interferometry, …

I Synthesis And Dynamic Studies Of Bifunctional Compounds Having Potential Intramolecular Interactions Ii Controlled Release Antifouling Coatings: Approaches To Controlled Release Of Gamma-Decanolactone And 2-Hexanoylfuran Into Seawater, Craig Anthony West

Doctoral Dissertations

I. Potentially reactive, bifunctional compounds 1 and 127 have been studied, and both compounds have been found to undergo rapid base-catalyzed degenerate topomerization. The topomerization processes, which in the case of 1 represents a degenerate transamidation and in the case of 127 a degenerate transesterification, have been studied in acetonitrile-d$\sb3$ and D$\sb2$O under a variety of conditions by the DNMR method. In both cases, the presence of a stable tetrahedral anion intermediate can be inferred from analysis of NMR and IR spectra. In the case of 1, the unusually high rate of topomerization can be attributed to the presence of …

A System Model For Multipath Interference On Terrestrial Line-Of-Sight Qam Digital Radio, Charles Henry Bianchi

Doctoral Dissertations

A comprehensive system model for characterizing the effects of multipath propagation on digital radio systems in the 4 to 6 GHz band is shown in this thesis. The effects of terrain-induced multipath propagation in the presence of atmospheric anomalies are studied using data from experimental microwave links in the field and in the laboratory. This technique, which treats multipath propagation as digital signal distortions caused by interference from ground reflections, has not been shown previously. A forward multipath propagation model is used to identify the critical propagation parameters for a QAM signal. A normalized two ray channel model is developed …

Characterization Of Supported Molybdenum Sulfide Catalyst Ex Ammonium Tetrathiomolybdate, Fan Zhang

Doctoral Dissertations

Active sulfide catalysts are conventionally prepared by converting the respective oxides to sulfides. Reductive sulfiding of the oxides is usually difficult and does not proceed in a regular manner. In this dissertation, a supported molybdenum sulfide catalyst prepared by the decomposition of ammonium tetrathiomolybdate (ATTM) in hydrogen and helium was studied. The catalyst is unique in two respects, namely, the lower valence state of the supported molybdenum sulfide catalyst, and the presence of few oxygen atoms in the catalyst. The thiophene hydrodesulfurization (HDS) and propylene hydrogenation (HYD) activities of a catalyst prepared by this technique (and subjected to different pretreatments) …

An Investigation Into Students' Conceptual Understandings Of The Graphical Representation Of Polynomial Functions, Judith Ellen Curran

Doctoral Dissertations

Mathematics educators are realizing the impact that technology is having on the way mathematical functions can be represented and manipulated. The increased use of graphing technology in the classroom is paralleled by an increased emphasis on the role of the graphical representation of a function to solve problems. These changes together with a recognition of the significance and complexity of developing a rich understanding of the graphical representations of polynomial functions are the motivation behind this research.

The study was designed to explore students' conceptual understandings of the graphs of polynomial functions. Guided by a constructivist approach to conceptual change, …

Reflected Light Microscopy, Electron Microscopy, Electron Spectroscopy, And X-Ray Diffraction Mineralogical Characterization Of Electric Arc Furnace (Eaf) Dusts, Ann M. Hagni

Doctoral Dissertations

"The secondary steel industry in the United States generates 600,000 tons of electric arc furnace (EAF) dust each year. Over 5,000,000 tons of EAF dust are generated annually world wide. The dust, which is removed from off-gasses from the high temperature furnaces, is considered by the Environmental Protection Agency to be hazardous waste due to its leachable lead, cadmium, and chromium. In addition to hazardous components, EAF dust contains valuable zinc, averaging 19%. This study was initiated to determine the mineralogy and characterization of the dust to aid in the processing of the dust for metals recovery and rendering the …

Fundamental Studies Of Grafting Reactions In Free Radical Copolymerization, Nai-Jen Huang

Doctoral Dissertations

A new method of measuring the efficiencies of free radical grafting reactions is presented. This technique utilized the compositional analysis capability of dual detector (UV and RI) gel permeation chromatography in which the mixture of polymer resulting from the graft copolymerization reaction is also subjected to separation by molecular size. Samples of the reaction mass drawn from a reactor are diluted with GPC carrier solvent and injected directly into the chromatograph without any other preparative step. Grafting efficiency, graft ratio, molecular weight distributions, and the frequency of graft chains along the backbone polymer are simultaneously determined. This simple technique overcomes …

Work And Power In Post-Fordist Production: A Case Study Of Four Machine Shops, Stephen A. Sweet

Doctoral Dissertations

American industry is shifting to a "post-Fordist" approach to production. The post-Fordist approach includes expanding use of advanced manufacturing technologies, decreasing organizational sizes, decreasing bureaucratization of the work place, and the abandonment of Tayloristic managerial practices in favor of increasing worker participation in decision making processes. This study examines the effects of the post-Fordist approach upon power relations in four work places in the machining industry.

Interviews with 44 machinists, employers and community leaders in the case study site "Machinist Valley" show that the shift to post-Fordism is accompanied by declining incomes, fewer employment opportunities, lower benefits, and less job …

Biomass Fuel Supply And Utilization In The Cities Of The Developing World: A Case Study Of Cebu City, Philippines, Terrence Gerard Bensel

Doctoral Dissertations

The island Province of Cebu is generally considered to represent one of the worst cases of extreme environmental degradation in the Southeast Asian region. Widespread dependence on woodfuels (biomass) by the island's 2.7 million inhabitants is often pointed to as a major cause of Cebu's environmental problems, prompting government and NGO officials in the region to call for tighter restrictions and regulation of the commercial woodfuel trade.

This dissertation was designed to assess the economic and environmental impact of woodfuel production and use in Cebu by focusing on three aspects of the local woodfuel system. First, a household energy survey …

Energy Conservation Potential Uncertainty Analysis, Gregory Allen Norris

Doctoral Dissertations

Previous studies which have generated estimates of the potential for cost-effective gains in energy efficiency have generally acknowledged the uncertainty in their inputs and conclusions, but none have gone beyond simple scenario analysis to quantify the uncertainties in their inputs or conclusions. This research develops and demonstrates methods for the explicit treatment of uncertainty in energy conservation potential analysis. New methods and critical data requirements are highlighted through application to the study of current weatherization potential.

Sensitivity analysis finds that, contrary to claims appearing in the literature, estimates of cost-effective conservation potential are more sensitive to uncertainties in empirical inputs …

Development Of Instrumentation To Study The Effects Of Aging On The Small Strain Behavior Of Sands, Heather Jane Miller

Doctoral Dissertations

The shear modulus is a direct indicator of sand fabric stiffness. It is a primary soil parameter affecting the response of sand deposits to cyclic shearing stresses and strains. Among the various factors which influence the shear modulus, the age at testing has been least studied. Typically, age effects have been thought of only in terms of geologic time. Recently, however, observations indicate that age effects operate over much shorter time spans (weeks to months), and that these age effects may be reversible; i.e. the sand fabric becomes stiffer as it evolves with time, but then the acquired stiffness may …

Ground Water Flow Model For Fractured Media, Ernesto Da Silva Pitombeira

Doctoral Dissertations

In fractured rock systems, ground water flow is not as simple and as methodical as in a porous medium. To create a numerical model of such a flow system, a four-part algorithm was written, which included MATLAB$\sp\circler$ as a fundamental component. It was intended that the model output define the zone of influence of pumping stresses. The four model parts are, sequentially: generation of the interconnected fracture geometry; generation of the linear finite element grid; the hydraulic calculations and the influence zone delineation. MATLAB$\sp\circler$ is used to stochastically generate the fracture geometry from empirical estimates of the probability distributions of: …

Nitrous Oxide Emissions From Tropical Soils, Antonio Donato Nobre

Doctoral Dissertations

Nitrous oxide ($\rm N\sb2O$), the third most important greenhouse trace gas in the troposphere and one contributor to ozone destruction in the stratosphere, has its concentration in the atmosphere increasing steadily over the last few decades. This study measured sources from tropical soils, potentially the highest and least studied $\rm N\sb2O$ production areas in the world.

For two tropical volcanic soils in Costa Rica the effect of water, nitrate and glucose additions on episodic emissions of nitrous oxide were studied. Magnitudes of episodic $\rm N\sb2O$ pulses, as well as overall $\rm N\sb2O$ emissions, varied considerably and consistently, depending on soil …

The Utilization Of Municipal Solid Waste Combustion Bottom Ash As A Paving Material, Xishun Zhang

Doctoral Dissertations

A research project was conducted to investigate the potentials of using municipal solid waste combustion bottom ash as a paving material. The effort focused on (i) characterization of the time-dependent properties of the bottom ash, (ii) bottom ash utilization as an unbound material in road subbase and base application, and (iii) bottom ash utilization as an aggregate substitution in hot mixture asphalt. A series of standard or non-standard procedures were employed to evaluate bottom ash behavior.

Results indicate that variability of the physical properties of the bottom ash produced during the two years study period is relatively small in view …

Genetic Engineering Of The Polyamine Biosynthetic Pathway And Somatic Embryogenesis In Carrot (Daucus Carota L), Dhundy Raj Bastola

Doctoral Dissertations

Ornithine decarboxylase (ODC), arginine decarboxylase (ADC), and S-adenosylmethionine decarboxylase (SAMDC) are three of the key regulatory enzymes involved in the biosynthesis of polyamines (putrescine, spermidine and spermine). To modulate the biosynthesis of putrescine, carrot (Daucus carota L.) cells were transformed with Agrobacterium tumefaciens strains containing 3$\sp\prime$-truncated mouse ornithine decarboxylase (ODC) cDNA under the control of a CaMV 35S promoter. Neomycin phosphotransferase gene linked with nopaline synthase promoter was used to select transformed cell lines on kanamycin. While the non-transformed cells contained no ODC, high levels of ODC activity were observed in the transformed cells. A significant increase in the cellular …

The Application Of Markov State Probabilities In Developing Artificially Intelligent Managerial Strategies: A Case Study Based On Major League Baseball, Arnold Vincent Arconati

Doctoral Dissertations

"Baseball is a very large industry that influences the lives and financial assets of millions of people.

Many baseball analysts estimate that even the best Major League player can increase his team's expected number of yearly wins by only 3 or 4 games. In 1993 Bobby Bonilla, a New York Mets National League outfielder, earned $5,200,000 more than the average Major League player earned. The Mets apparently believed that expenditure of this money was worth his expected additional victories. If the strategy of an Artificially Intelligent baseball manager could produce 4 more team victories than the corresponding human baseball manager, …

Hydrodynamic Studies Of The Flow Of Fine Particles Through A Fluidized Dense Bed Of Coarse Solids, Jaideep Talukdar

Doctoral Dissertations

This study explains the hydrodynamics of a circulating fluidized bed (CFB) system, the Battelle Multi-Solids Fluidized Bed System (MSFB). It consists of a circulating fluidized bed of fine particles superimposed on a bubbling bed of coarse solids.

One way to characterize such a system is to describe the mechanism of gas-solid flow through the bed. The gas flow in systems like these is through bubbles or slugs (regions of voids containing little or no solids). Bubbles are typically characterized by their size (length or diameter), their rise velocity, and their frequency.

Another task of the initial phase of this study …

The Spatial Distribution Of Snow And Aerosol Chemistry In The Mountains Of Central Asia, Cameron Parker Wake

Doctoral Dissertations

Central Asia represents one of the largest voids with respect to our understanding of geochemical cycles in the continental troposphere and hydrosphere. Fortunately, the vast extent of glaciers in central Asia provide several high elevation ($>$5000 m) locations from which to recover glaciochemical records, and thereby furnish a unique window through which to study biogeochemical cycles in the mid- to upper-troposphere.

Snow and ice samples collected from nine glacier basins spread throughout the mountains of central Asia were analyzed for their major ion and particle content. Aerosol samples collected from four sites in central Asia were analyzed for their …

Automatic Tool Path Generation For Numerically Controlled Machining Of Sculptured Surfaces, Xiaoxia Li

Doctoral Dissertations

This dissertation presents four new tool path generation approaches for numerically controlled machining of sculptured surfaces: TRI$\sb-$XYINDEX, FINISH, FIVEX$\sb-$INDEX, FIX$\sb-$AXIS$\sb-$INDEX. All of the above systems index the tool across the object surface in the Cartesian space so that evenly distributed tool paths are accomplished.

TRI$\sb-$XYINDEX is a three-axis tool path generation system which uses a surface triangle set (STS) representation of the surface for tool position calculations. Surface edges are detected with local searching algorithms. Quick tool positioning is achieved by selecting candidate elements of polygons. Test results show that TRI$\sb-$XYINDEX is more efficient when machining surfaces which are relatively …

An Analysis Of North Sea Oil Development And Scottish Island Youth: Postmaterialism As An Identifiable And Measurable Dimension, John Alan Anderson

Doctoral Dissertations

This study examines opinions and attitudes of high school age youth living in the Shetland and Orkney islands and explores aspects of rapid growth associated with North Sea oil development. Only a minimal amount of research regarding post-impacts and rapid growth appears in the literature. Studies that do exist lack in theory and methodological consistency. This study draws ideas from mainstream sociology, Social Impact Assessment (SIA), Quality of Life (QoL) and Inglehart's materialism/postmaterialism to develop a working theory of social values and rapid growth. This study further reviews and applies six methodological considerations useable in future SIA, QoL, or boomtown …

Physical Behavior Of Computing Networks With An Emphasis On Routing, Peter George Drexel

Doctoral Dissertations

Combining powerful, local computing capability with inexpensive packet switched communication invites the creation of a new entity--the computing network. A computing network is a group of computer systems, interconnected by a packet switched network, which cooperate to accomplish a specific task.

Efficient communication between computer systems is critical. The accepted method of dealing with packet congestion is to limit network operation to linear regions ($\le$80 percent of total capacity).

Because of large parameter spaces, the behavior of computing networks is complex and not easily predictable with current techniques except in the simplest, linear region of operation. Since traditional approaches are …

A Computer Model Of The Role Of Text Integration In The Solution Of Arithmetic Word Problems, Mark David Leblanc

Doctoral Dissertations

Understanding arithmetic word problems involves a complex interaction of text comprehension and mathematical processes. This work presents a computer model of the hypothesized processes that are required of a young student solving arithmetic word problems, including the processes of sentence-level leading and text integration. Unlike previous computer simulations of word problem solving, which neglect the early stages of text processing, this model forces a detailed consideration of the linguistic process, which is being increasingly recognized as a primary source of difficulty. Three experiments were conducted to isolate critical test comprehension processes. Children's probability of solution was analyzed in regression analyses …

Rapid Hydropyrolysis Of Coals For Production Of Liquid Hydrocarbons, Abdul Rahman Mohamed

Doctoral Dissertations

Production of fuels and chemicals from coal is becoming attractive due to potential high cost and uncertain supply of crude petroleum oil. Conventional techniques of coal liquefaction, though technically feasible, have been expensive due to hydrogen requirements, high pressure equipment, and high cost of commercial supported catalysts.

In this study, a novel technique for rapid hydropyrolysis of bituminous, subbituminous, and lignite coals has been investigated. Rapid hydropyrolysis is the process of heating at a fast rate to high temperature in a hydrogen environment. A coal sample in hydrogen atmosphere is targeted, in the absence of a catalyst, with a high …

Genetic And Molecular Analyses Of Host Symbiotic Genes And An In Vitro Regeneration System For Cicer Arietinum L, Vijayashri Ganapathy Paruvangada

Doctoral Dissertations

Ineffectively nodulating plant mutants PM405B, PM638A, and PM796B were used in molecular/genetic analyses of root nodule formation in chickpea. To establish the mode of inheritance of the mutant nodule phenotype in chickpea mutant PM638A, reciprocal crosses were made between PM638A and wild-type ICC640. The F$\sb2$ segregation data fit a 3 mutants: 1 wild-type monohybrid phenotypic ratio, indicating that ineffective nodulation is due to a monogenic dominant, nuclear mutation, tentatively designated as "Rn$\sb7$". Segregation analysis of F$\sb3$ progeny confirmed this model.

Early (ENod2) and late (Lb) nodulin cDNAs were used as heterologous probes to identify and study the expression of corresponding …

Hydrodynamics And Heat Transfer Of Circulating Fluidized Bed, Chunming Qi

Doctoral Dissertations

The investigation of the hydrodynamics of gas-particle suspension in a circulating fluidized bed (CFB) focused on the radial (lateral) particle flux measurement, the mechanism of the radial particle concentration distribution, the mechanism and the model of particle convection heat transfer, and the pressure balance in the CFB loop, all of which affect the hydrodynamics, thermal efficiency and stability of a CFB.

The radial particle fluxes in a cold-flow CFB riser (14.0 cm i.d., 6.4 m high) were directly measured by specially designed probes. Two types of particles were used; glass beads of 200 $\mu$m diameter, and FCC catalyst of 70 …

Fiber-Reinforced Plastic Grids For The Structural Reinforcement Of Concrete Beams, Joseph Robert Yost

Doctoral Dissertations

The research presented in this dissertation evaluates the performance of simply supported concrete beams reinforced with a 2 dimensional Fiber Reinforced Plastic (FRP) grid. The non-corrosive, high strength properties characteristic of FRP materials make them a desirable structural reinforcement for concrete in environments where high concentrations of chloride ions are present.

The FRP grid under investigation is called NEFMAC and it is manufactured by Turay Industries of Tokyo Japan. NEFMAC is dimensionally fabricated as orthogonally intersecting longitudinal and transverse bars. The bars are continuous at the intersection points and, as such, there exists no preferred or strong direction within the …

A Massively Parallel Simd Processor For Neural Network And Machine Vision Applications, Michael A. Glover

Doctoral Dissertations

This thesis describes the MM32k, a massively parallel SIMD computer which is easy to program, high in performance, low in cost and effective for implementing highly parallel neural network architectures. The MM32k has 32768 bit serial processing elements, each of which has 512 bits of memory, and all of which are interconnected by a switching network. The entire system resides on a single PC-AT compatible card. It is programmed from the host computer using a C++ language class library which supports variable precision vector arithmetic. The MM32k also supports direct video input and output for machine vision applications.