Digital Commons Network^™

Optimization Of Optical Computed Tomography Techniques For The Synthesis Of Particle Aggregate Models, Patrick Anthony Giordano Jr.

Theses and Dissertations

The characterization of 3-D shapes of particles in geomaterial aggregate mixtures is important for understanding the micro-mechanics of granular materials. Also, numerical synthesis of 3-D particle shapes from their corresponding shape descriptors is required for developing discrete element models (DEMs) that can be used to predict particle contact-forces, and ultimately the shear strength of the aggregate mixture.

Previous work has shown that Fourier-based 3-D shape descriptors can be constructed for aggregate mixtures, using a statistical combination of 2-D projections. Furthermore, optical tomography methods using the Algebraic Reconstruction Technique (ART) algorithm has proved capable of synthesizing 3-D shapes from 2-D projections, …

Interactive Visualization Of Information Hierarchies And Applications On The Web, Confesor Santiago Iii

Theses and Dissertations

The visualization of information hierarchies is concerned with the presentation of abstract hierarchical information about relationships between various entities. It has many applications in diverse domains such as software engineering, information systems, biology, and chemistry. Information hierarchies are typically modeled by an abstract tree, where vertices are entities and edges represent relationships between entities. The aim of visualizing tree drawings is to automatically produce drawings of trees which clearly reflect the relationships of the information hierarchy.

This thesis is primarily concerned with problems related to the automatic generation of area-efficient grid drawings of trees, interactively visualizing information hierarchies, and applying …

Extending The Information Partition Function: Modeling Interaction Effects In Highly Multivariate, Discrete Data, Paul C. Cannon

Theses and Dissertations

Because of the huge amounts of data made available by the technology boom in the late twentieth century, new methods are required to turn data into usable information. Much of this data is categorical in nature, which makes estimation difficult in highly multivariate settings. In this thesis we review various multivariate statistical methods, discuss various statistical methods of natural language processing (NLP), and discuss a general class of models described by Erosheva (2002) called generalized mixed membership models. We then propose extensions of the information partition function (IPF) derived by Engler (2002), Oliphant (2003), and Tolley (2006) that will allow …

Incorporating Grain Size Effects In Taylor Crystal Plasticity, Bradley S. Fromm

Theses and Dissertations

A method to incorporate grain size effects into crystal plasticity is presented. The classical Hall-Petch equation inaccurately predicts the macroscopic yield strength for materials with non-equiaxed grains or materials that contain unequal grain size distributions. These deficiencies can be overcome by incorporating both grain size and orientation characteristics into crystal plasticity theory. Homogenization relationships based on a viscoplastic Taylor-like approach are introduced along with a new function, the grain size and orientation distribution function (GSODF). Estimates of the GSODF for high purity α-titanium are recovered through orientation imaging microscopy coupled with the chord length distribution. A comparison between the new …

Preparation Of Divalent And Trivalent Antigens For Immunogical Studies On Degranulation Of Mast Cells And Preparation Of Ceragenins For Antiviral Studies Against Vaccinia Virus., Dianliang Geng

Theses and Dissertations

CHAPTER 1

Aggregation of receptors for IgE (Fc RI) causes mast cells and basophils to release preformed contents of granules, including histamine and a variety of enzymes. This process, called degranulation plays a central role in allergic reactions. Methods to study this process are to create multivalent ligands which can interact with the receptors and, in turn, lead to aggregation of the receptors. We prepared a series of fluorophore-labeled divalent and trivalent antigens to study the degranulation of mast cells. Trivalent antigens proved to be much better stimulators for degranulation of mast cells than divalent antigens. These results indicate that …

Forensics Image Background Matching Using Scale Invariant Feature (Sift)Transform And Speeded Up Robust Features (Surf), Paul N. Fogg Ii

Theses and Dissertations

In criminal investigations, it is not uncommon for investigators to obtain a photograph or image that shows a crime being committed. Additionally, thousands of pictures may exist of a location, taken from the same or varying viewpoints. Some of these images may even include a criminal suspect or witness. One mechanism to identify criminals and witnesses is to group the images found on computers, cell phones, cameras, and other electronic devices into sets representing the same location. One or more images in the group may then prove the suspect was at the crime scene before, during, and/or after a crime. …

Pyridinium Bisretinoids: Synthesis And Photoactivated Cytotoxicity, Junping Gao

Theses and Dissertations

This thesis discusses pyridinium bisretinoid compounds (PBRs), which were prepared for two purposes: 1) to use them as standards for detection of novel fluorophores in human RPE cells, which may be involved in age-related macular degeneration (AMD), and 2) to use them in the development of a targeted and triggered drug delivery system for cancer therapy. We prepared a selection of PBRs using a one-pot biomimetic method; synthesis, mechanisms for formation, and characterization of these compounds is described. We also explored the photoreactivity of three novel PBR compounds and found that these PBRs form oxidation products under blue-light irradiation. The …

Adolescent Girls' Perception Of Residential Treatment Centers: A Qualitative Study Of How Treatment Works, Tyler Adam Money

Theses and Dissertations

RTCs play an increasingly significant role in the continuum of treatment of emotionally disturbed adolescents. However, outcome research in this area has lagged behind the growth of treatment centers. More specifically, there has been very little investigation of the relative efficacy of the many different aspects of residential treatment, which are referred to as mechanisms of change in other research. The present study attempts to develop a phenomenological understanding of RTC patients' experience of all of the interventions that make up residential treatment. Results suggest that patients view social support, non-therapist staff members, family involvement and family therapy, as most …

A Biomechanical Analysis Of Male And Female Intermediate Hurdlers And Steeplechasers, Laurence R. Bollschweiler

Theses and Dissertations

In the sport of track and field, proper hurdling technique is a complicated combination of various running and jumping kinematics. With most research having been done on sprint hurdling, there is a growing need for research on hurdling events of different lengths. The intermediate hurdles (IH) and the steeplechase (SC) are two events where there are a number of differences in hurdling technique. This study compared the differences in hurdling technique between events (IH and SC) as well as the differences in technique between genders. Subjects for this study consisted of 20 elite intermediate hurdlers (10 male, 10 female) and …

A Unified Framework For Solving Multiagent Task Assignment Problems, Kevin Cousin

Theses and Dissertations

Multiagent task assignment problem descriptors do not fully represent the complex interactions in a multiagent domain, and algorithmic solutions vary widely depending on how the domain is represented. This issue is compounded as related research fields contain descriptors that similarly describe multiagent task assignment problems, including complex domain interactions, but generally do not provide the mechanisms needed to solve the multiagent aspect of task assignment. This research presents a unified approach to representing and solving the multiagent task assignment problem for complex problem domains. Ideas central to multiagent task allocation, project scheduling, constraint satisfaction, and coalition formation are combined to …

Electrical Activation Studies Of Silicon Implanted Aluminum Gallium Nitride With High Aluminum Mole Fraction, Elizabeth A. Moore

Theses and Dissertations

This research demonstrates a method for producing highly conductive Si-implanted n-type aluminum gallium nitride (Al_xGa_1-xN) alloys, and represents a comprehensive analysis of the resulting material's electrical and optical properties as a function of Al mole fraction, anneal temperature, anneal time, and implantation dose. Highly conductive alloys are critical to the fabrication of devices operating in deep UV, high-temperature, high-power, and high-frequency environments, and thus this research is significant in regard to the application of such devices. The Al_xGa_1-xN wafers of this study, with Al concentrations of 10 to 50%, were implanted at …

Phenolic Resin/Polyhedral Oligomeric Silsesquioxane (Poss) Hybrid Nanocomposites And Advanced Composites For Use As Anode Materials In Lithium Ion Batteries, Sang Ho Lee

Theses and Dissertations

The work presented in this thesis can be divided into two research areas. First, two sets of organic-inorganic hybrid nanocomposites containing phenolic resin/trisilanolphenyl-POSS and phenolic resin/octa(aminophenyl)-T8-POSS nanocomposites were synthesized and the morphology and properties were investigated. Octa(aminophenyl)-T8-polyhedral silsesquioxane is an octafunctional-T8-POSS containing eight aniline-like amino groups, one on each corner silicon atom. It was synthesized in our laboratory by an improved two-step reaction sequence; nitration (HNO3) and reduction (HCOOH/Et3N). Varying amounts of POSS were codissolved with a resole phenolic resin in organic solvent. This was followed by solvent removal and thermal curing. Intermolecular interactions in these nanocomposites were probed by …

Dielectrophoretic Characterization Of Abo Blood Type, Frequency And Ac Field Strength Of Erythrocytes, Prashant Reuben Daggolu

Theses and Dissertations

This research investigates the role of ABO blood type of erythrocytes in their dielectrophoretic response. The dielectrophoresis of erythrocytes of positive ABO blood types was studied at 5 V (peak to peak) and 1 MHz frequency AC field. The study revealed that the ABO blood type had an influence on the dielectrophoretic motion of the erythrocytes, particularly separating AB+ and O+ blood types. This is of particular significance since AB+ is a universal acceptor and O+ is a universal donor for blood transfusion purposes. The influence of field parameters, namely field strength and frequency of the AC field, was also …

Non-Equilibrium Surface Growth For Competitive Growth Models And Applications To Conservative Parallel Discrete Event Simulations, Poonam Santosh Verma

Theses and Dissertations

Non-equilibrium surface growth for competitive growth models in (1+1) dimensions, particularly mixing random deposition (RD) with correlated growth process which occur with probability $p$ are studied. The composite mixtures are found to be in the universality class of the correlated growth process, and a nonuniversal exponent $\delta$ is identified in the scaling in $p$. The only effects of the RD admixture are dilations of the time and height scales which result in a slowdown of the dynamics of building up the correlations. The bulk morphology is taken into account and is reflected in the surface roughening, as well as the …

Socioeconomic Development In The Southeast Region Of The United States From 1995 - 2000: A Structural Equation Modeling And A Gis Modeling Approach, Erdenechimeg Eldev-Ochir

Theses and Dissertations

This research presented in this study demonstrates that county level population growth, economic growth, and localized social structure are interrelated. An analysis of the spatial distribution of these factors in the Southeast Region of the United States during the period of 1995-2000 also indicates the importance of differences in rural versus urban and coastal versus non-coastal areas as well as the importance of such factors as highways, large cities, and universities in economic, population, and social structure interrelationships. An extensive dataset is used in the analysis as a number of analysis tools including statistical analysis, econometric models, spatial econometric models, …

Students' Perceptions Of College Technology Programs And Acquired Technology Skills, Ling Ling Yen

Theses and Dissertations

Students, the nation’s potential workforce, must acquire the needed entry-level technology skills demanded in the work environment. Business leaders question whether students are graduating from technology programs with appropriate and adequate technology skills. The purpose of this study was to determine how two-year and four-year college students assess their college technology programs and how they perceive the adequacy of the technology skills they had acquired in meeting workplace needs. A secondary purpose was to determine if differences existed based on demographic characteristics of participants. A survey research design was used in this study. The survey instrument consisted of three sections: …

Watermarking With Wavelet Transforms, Kristen Michelle Parker

Theses and Dissertations

Digital watermarking algorithms based on wavelet transforms provide increased performance and perceptual quality. This thesis proposes two wavelet-based schemes: one robust and one fragile. Robust watermarks should withstand attacks, such as compression, while maintaining the data integrity. The first approach presented is an algorithm which implements image watermarking in the domain of an overcomplete, or redundant, wavelet transform. Alternately, fragile watermarks are intended for use in applications wherein any loss of image quality is not acceptable. In the second approach presented, data embedding in the domain of an integer wavelet transform is considered. An algorithm is proposed that uses a …

Birds And Small Mammals, Intensively Established Pine Plantations, And Landscape Metrics Of The Coastal Plain, Brice Bond Hanberry

Theses and Dissertations

I evaluated effects of 5 treatments for pine plantation establishment on breeding and wintering birds and small mammals during years one through 5 post-treatment in the Lower Coastal Plain of Mississippi. I modeled relationships between 8 vegetation variables and avian abundance to identify influential habitat components in pine plantations. At the landscape scale, I compared avian abundance of regionally important species with land class variables in the Coastal Plain of Georgia. In pine plantations, species richness, total abundance, and 2 conservation bird metrics generally decreased with increasing intensity of stand establishment. Thus, this study suggests that increasing standmestablishment intensity can …

Effect Of Distance Learning Technology As A Training Delivery System For Rural And Small Law Enforcement Agencies, Thomas C. Johnson

Theses and Dissertations

This study examined the perceptions of law enforcements officers employed by rural and small law enforcement agencies on the effectiveness of the use of distance education technology as a delivery system for training programs. Four research questions were designed to assess officers’ perceptions. This study used both quantitative and qualitative analysis of data to assess these questions. Quantitative data were collected through the use of a pretest and post-test, and a survey. Qualitative data were collected through observations of subjects’ interaction with the treatment, interviews with participants, reviews of survey comments, and analyses of budget documents. The results of this …

"W"- Men: Male Nurses' Negotiation Of Masculinity In A Predominantly Female Profession, Deborah Yoder (Deborah Jane Yoder) Miranda

Theses and Dissertations

This qualitative study explores male nurses’ negotiation of masculine gender identities in the nontraditional work of registered nursing. Few registered nurses in the United States are men, and men leave the profession within the first four years after graduation at twice the rate of women. This study builds on previous work by seeking to understand why male nursing graduates of an institution formerly for women only, made the decision to become nurses, how they decided to attend a women’s college over a more gender balanced campus experience, and in what ways they negotiate gender identities in the configuration of nursing …

Physiologically-Based Toxicokinetic And Toxicodynamic (Pbtk/Td) Modeling Of A Ternary Organophosphorus Insecticide Mixture In Rats: Model Development And Validation, Julian Thomas Pittman

Theses and Dissertations

A physiologically-based toxicokinetic and toxicodynamic (PBTK/TD) model was developed, from the open literature, to predict the toxicokinetic disposition and toxicodynamic response (acetylcholinesterase inhibition) of a ternary organophosphorus (OP) insecticide mixture: chlorpyrifos (CP), methyl parathion (MP) and parathion (P). In vivo studies were conducted in adult male Sprague-Dawley rats, orally administered one of two CP/MP/P mixtures (2.5, 0.5, 0.5 mg/kg or 5, 1, 1 mg/kg) with selected tissues (blood, brain, diaphragm, liver, lung and skeletal muscle) collected at 30min, 4, 12 and 24hr postdosing. Low dosages were studied so the mixture did not result in significant disruption of cardiovascular function nor …

Selection For Reduced Seed Dormancy In Seven Native Grass Species, Kyle Bradley Holmberg

Theses and Dissertations

Lowland switchgrass (Panicum virgatum), big bluestem (Andropogon gerardii), indiangrass (Sorghastrum nutans), upland switchgrass (Panicum virgatum), little bluestem (Schizachyrium scoparium), beaked panicum (Panicum capillare), and purpletop (Tridens flavus) all show strong signs of seed dormancy which contributes to extremely poor field establishment. The objective of this work was to reduce seed dormancy by selecting individuals that exhibited reduced pre-stratification dormancy in laboratory tests. The classical breeding method of phenotypic recurrent selection was used to enhance germination. Of the three tall-stature species, lowland switchgrass made the greatest improvement in pre-stratification germination, followed by indiangrass and big bluestem. The four short stature species …

Quantitative Genetic Analysis For Flowering Time In Primitive Upland Cotton, Gossypium Hirsutum L., And Chromosome Assignment Of Bac-Derived Ssr Markers, Yufang Guo

Theses and Dissertations

Cotton is a very important economical crop in the U.S. and throughout the world. The developments in molecular biology offer new and innovative approaches toward evaluating and understanding genetic mechanisms of important agronomical traits. Bacterial artificial chromosome (BAC) libraries have rapidly become the preferred choice for physical mapping. BAC-derived microsatellite or simple sequence repeats (SSRs) markers facilitate the integration of physical and genetic recombination maps. The first objective in this research was to identify chromosome locations of a set of BAC-derived SSR markers in tetraploid cotton. A total of 192 SSR primer pairs were derived from BAC clones of an …

Microstructure-Property Relations Throughout The Powder Metallurgy Process, Laura Arias Tucker

Theses and Dissertations

To produce crack free powder compacts with desirable mechanical properties and uniform densities, a predictive finite element simulation of the powder metallurgy process is necessary (compaction and sintering). The finite element method, through the use of appropriate constitutive material models captures the microstructure-property history after compaction and sintering. A FC-0205 cylinder and FC-0208 automotive main bearing cap were compacted to investigate the microstructure changes at different locations within the parts. Measurements of the pore volume fraction, pore size, pore nearest neighbor, pore aspect ratio, and grain size were performed after compaction for the cylinder after compaction and after compaction and …

Micro-Structural Response Of Dp 600 To High Strain Rate Deformation, Brian Fredrick Hamburg

Theses and Dissertations

The object of this study was to investigate the micro-structural response of DP 600 subjected to high strain rate, ballistic impact tests. The ballistic tests were conducted using normal impact of a hardened steel penetrator into a 2 mm thick sheet of DP 600. The average strain rates produced from this test method are on the order of 10^5 s-1. Multiple methods were used to investigate the micro-structure before and after high strain rate deformation including optical microscopy, electron microscopy, and X-ray diffraction. A large variation in material response was observed between tests conducted at 0.8 x 10^5 and 2.5 …

Treatment Acceptabilty Of Teachers Of Adolescents By Level Of Intervention Intrusiveness And Type Of Disorder, Sarah E. Graves

Theses and Dissertations

The purpose of the current study was to examine the treatment acceptability ratings of teachers of adolescents on three different types of commonly used interventions: (a) positive verbal praise, (b) token economy with response cost and extinction, and (c) psychotropic medication. Ratings of treatment acceptability were also assessed according to type of disorder (i.e., externalizing or internalizing). The participants were 101 teachers of adolescents recruited from a midwestern public school district. Participants were asked to read two case studies presented in a counterbalanced format. One case study focused on a youth who displayed symptoms related to an internalizing disorder (Major …

Anglican Church Policy, Eighteenth Century Conflict, And The American Episcopate, Kenneth Ray Elliott

Theses and Dissertations

This dissertation examines how leaders in the Church of England sought to reorganize the colonial church at critical moments, in the late 1740s, the early 1760s and the mid 1770s, by installing one or two resident bishops when the British government moved to bring the colonies into closer economic and political alignment with England. Examining Anglican attempts to bring bishops to the American colonies within the context of the Anglo-American world moves beyond the current literature and provides insight into the difficulties British political and ecclesiastical authorities had managing the colonies more efficiently. Even though the Church of England sustained …

A Multi-Scale Approach To Evaluate The Effect Of The Invasive Aquatic Plant Hydrilla (Hydrilla Verticillata) On Littoral Zone Habitat Of Juvenile Largemouth Bass (Micropterus Salmoides), Alexander James Perret

Theses and Dissertations

Two experiments were conducted to investigate the hypothesis that exotic macrophytes alter littoral zone habitat and impact fish that inhabit these areas. The pond experiment was conducted to explore impacts of exotic invasive plants on growth and condition of juvenile largemouth bass (Micropterus salmoides). The second experiment was conducted at a smaller scale in aquaria to simulate an invasion of hydrilla (Hydrilla verticillata) and its influence on juvenile bass foraging. Fish experienced slower growth in the hydrilla treatment than in the diverse, and the ability of bass to capture prey fish was impeded in hydrilla. Juvenile bass growth decreased in …

A Simple Two-Equation Turbulence Model For Transition-Sensitive Cfd Simulations Of Missile Nose-Cone Geometries, Joseph Matthew Jones

Theses and Dissertations

This study reports the development and validation of a modified two-equation eddy-viscosity turbulence model for computational fluid dynamics prediction of transitional and turbulent flows. The existing terms of the standard k-w model have been modified to include transitional flow effects, within the framework of Reynolds-averaged, eddy-viscosity turbulence modeling. The new model has been implemented into the commercially available flow solver FLUENT and the Mississippi State University SimCenter developed flow solver U2NCLE. Test cases included flow over a flat plate, a 2-D circular cylinder in a crossflow, a 3-D cylindrical body and three conical geometries, which represent the nose-cones of aerodynamic …

Occurrence Of Diseases And Insect Pests In Select Soybean (Glycine Max (L.) Merr.) And Sorghum (Sorghum Bicolor (L.) Moench) Rotations In Mississippi, Sergio Tomas Pichardo

Theses and Dissertations

Field and greenhouse studies were conducted during 2004 through 2006 at the Rodney R. Foil Plant Science Research Center, Starkville, MS. Six sorghum and soybean rotation treatments were tested to determine their effect on plant pathogen, insect, and nematode diversity and density levels. Treatments included 1) continuous sorghum, 2) continuous soybean, 3) sorghum-soybean-sorghum rotation, 4) soybean-sorghum-soybean rotation, 5) sorghum-soybean-soybean rotation, and 6) soybean-sorghum-sorghum rotation. Several nematode and insect species were identified during the study, but were always below economic thresholds. Six insect species were identified on soybean during each growing season and used as the indicator species for this study. …