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All Dissertations

2015

Articles 1 - 19 of 19

Full-Text Articles in Physical Sciences and Mathematics

High Temperature Synthesis And Characterization Of Reduced Polyoxometalate Salt-Inclusion Solids, Dino Sulejmanovic Dec 2015

High Temperature Synthesis And Characterization Of Reduced Polyoxometalate Salt-Inclusion Solids, Dino Sulejmanovic

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Herein, several new salt-inclusion solids (SISs) featuring electronically reduced Keggin polyoxometalate (POM) clusters were isolated for the first time using molten-salt high temperature (> 500 oC) synthetic method. These POM-based SISs are novel all-inorganic materials featuring an integrated lattice of ionic halide salt and covalent metal oxide clusters. Due to the weak interactions at the interface between these two chemically dissimilar lattices, these POM SISs are soluble in aqueous and polar solvents. While POM compounds are well-studied and are routinely synthesized in solution, the synthetic method presented in this dissertation yielded several POM solids with interesting structures and infrequently observed, …

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Towards A Greater Understanding Of Hydrothermally Grown Garnets And Sesquioxide Crystals For Laser Applications, Cheryl Moore Dec 2015

Towards A Greater Understanding Of Hydrothermally Grown Garnets And Sesquioxide Crystals For Laser Applications, Cheryl Moore

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ABSTRACT The hydrothermal method of crystal growth offers many benefits over traditional melt-based techniques such as lower temperature requirements relieving detrimental high temperature effects such as stress fracturing and a closed-environment, which limits impurities. The continued study of this type of growth including hydrothermal epitaxy is crucial in our world of constant miniaturization. Presented in this thesis is the hydrothermal growth of crystals of LuAG and Lu2O3 doped with a variety of dopants. Their room-temperature and cryogenic absorption spectra are also presented. Much like Nature uses heat, pressure, water and a nutrient-rich feedstock we have used this hydrothermal technique to …

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Objective Bayesian Analysis On The Quantile Regression, Shiyi Tu Dec 2015

Objective Bayesian Analysis On The Quantile Regression, Shiyi Tu

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The dissertation consists of two distinct but related research projects. First of all, we study the Bayesian analysis on the two-piece location-scale models, which contain several well-known sub-distributions, such as the asymmetric Laplace distribution, the skewed normal distribution, and the skewed Student-t distribution. The use of two-piece location-scale models is an attractive method to model non-symmetric data. From a practical point of view, a prior with some objective information may be more reasonable due to the lack of prior information in many applied situations. It has been shown that several common used objective priors, such as the Jeffreys prior, result …

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Tracking Anisotropic Optical Tracers To Study Biophysical Processes And Cytotoxicity, Khanh Van Nguyen Dec 2015

Tracking Anisotropic Optical Tracers To Study Biophysical Processes And Cytotoxicity, Khanh Van Nguyen

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We use anisotropic optical tracers (also called magnetically modulated optical nanoprobes – MagMOONs or MOONs for non-magnetic nanoprobes in this dissertation) to study biophysical processes such as enzyme-catalyzed cleavage through tissue, intracellular transport of these tracers and cytotoxicity based on this transport. The anisotropic optical properties cause these tracers to blink when rotating. This blinking is distinguishable from the background and can be tracked on a single-particle level in the absence of tissue, or for an ensemble average of tracers blinking through tissue. An alginate gel containing these tracers in the form of a thin film can be used as …

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Bombardment Simulations And Intercalation Studies Of Carbon Materials, Charles Lowe Dec 2015

Bombardment Simulations And Intercalation Studies Of Carbon Materials, Charles Lowe

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Molecular bombardment experiments have led to the possibility of altering materials with properties not normally associated with those materials. Molecular bombardment leads to defect formation in the material, potentially creating a pore, depending on the material and bombarding molecule. Carbon allotropes, specifically graphite and graphene, make excellent candidates for molecular bombardment experimentation. Depending on the bombarding molecule and the kinetic energy associated with that molecule, the defects induced will be sufficient to create a pore in the graphene. The AIREBO potential is used to simulate a graphene bilayer being bombarded with a single Ar atom, or a fullerene molecule, to …

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Iterative Design And Testing Of A Mobile Application To Support Food Consumption Monitoring And Decision Making, Melva James Dec 2015

Iterative Design And Testing Of A Mobile Application To Support Food Consumption Monitoring And Decision Making, Melva James

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Food overconsumption is a major contributor to weight gain leading to obesity. Constant exposure to larger amounts of food and beverage has caused many individuals to experience “portion distortion,” the perception that bigger portion sizes are appropriate for consumption at a single sitting. Independently and accurately changing this perception can be very difficult even if one has a desire to do so. In response to these observations, we developed and tested Picture-Perfect Portions, a mobile application designed to combat overconsumption, at the individual level, by leveraging the power of simple visualizations to help adults understand and adjust their food consumption …

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Development Of A Miniaturized Ambient Glow Discharge Ionization Source And Its Application In Elemental And Molecular Analysis, Xinyan Zhang Dec 2015

Development Of A Miniaturized Ambient Glow Discharge Ionization Source And Its Application In Elemental And Molecular Analysis, Xinyan Zhang

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Since the liquid sampling-atmospheric pressure glow discharge (LS-APGD) was first developed as an excitation source for atomic emission spectroscopy, it has been improved upon and demonstrated as an ionization source for elemental mass spectrometry, molecular mass spectrometry, and ambient desorption mass spectrometry. Multiple functions coming from one package allowed the LS-APGD to hold a unique position among all atmospheric pressure glow discharges. It also has the capabilities to work with different sample forms including liquids, bulk solids, and solution residues. The high salt/matrix tolerance reduces sample prep work and thus provides convenience for its potential use as a field-Based ionization …

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Production And Characterization Of Cut Resistant Acrylic/Copolyaramid Fibers Via Bicomponent Wet Spinning, Stephen Hipp Dec 2015

Production And Characterization Of Cut Resistant Acrylic/Copolyaramid Fibers Via Bicomponent Wet Spinning, Stephen Hipp

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A composite fiber system consisting of a sheath core bicomponent polymer fiber loaded with hard ceramic particles was developed and characterized for use in cut protective clothing. The core component was comprised of a copolyaramid in order to provide high base cut resistance. An acrylic-copolyaramid polymer blend was used for the sheath component to improve processability and provide potential benefits such as dyeability. Lastly, aluminum oxide particles were incorporated into the fiber core to deflect and deform the cutting edge, further improving cut resistance. A series of designed experiments was used to explore the effects of the wet spinning and …

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Multi-Factor Models To Resolve Growth Responses In Vitro And During Subsequent Greenhouse Growth For Turmeric (Curcuma Longa L.), Rabia El-Hawaz Dec 2015

Multi-Factor Models To Resolve Growth Responses In Vitro And During Subsequent Greenhouse Growth For Turmeric (Curcuma Longa L.), Rabia El-Hawaz

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Plant media has been developed over the last six decades, yet, there has not been medium optimized for microplant greenhouse growth, which may be important for producing chemical compounds and preparing transplants for success in the field. A series of multi-factor optimization experiments were conducted on turmeric (Curcuma longa L., genotype L 35-1) to identify the effects of mineral nutrition and plant density in vitro on laboratory and greenhouse production. The first experiment optimized PO43-, Ca2+, Mg2+, and KNO3 for five-months growth in bioreactors with periodic supplementation of sucrose solution +/- nutrients. Phosphorus (6.25 mM) increased sucrose supplement and rhizome …

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Bayesian Minimum Description Length Techniques For Multiple Changepoint Detection, Hewa Anuradha Priyadarshani Dec 2015

Bayesian Minimum Description Length Techniques For Multiple Changepoint Detection, Hewa Anuradha Priyadarshani

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This dissertation develops a minimum description length (MDL) multiple changepoint detection procedure that allows for prior distributions. MDL methods, which are penalized likelihood techniques with penalties based on data description-length information principles, have been successfully applied to many recent multiple changepoint problems. This work shows ow to modify the MDL penalty to account for various prior knowledge. Our motivation lies in climatology. Here, a metadata record, which is a file listing times when a recording station physically moved, instrumentation was changed, etc., sometimes exists. While metadata records are notoriously incomplete, they permit the construct a prior distribution that helps detect …

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Downstream Bandwidth Management For Emerging Docsis-Based Networks, Gongbing Hong Dec 2015

Downstream Bandwidth Management For Emerging Docsis-Based Networks, Gongbing Hong

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In this dissertation, we consider the downstream bandwidth management in the context of emerging DOCSIS-based cable networks. The latest DOCSIS 3.1 standard for cable access networks represents a significant change to cable networks. For downstream, the current 6 MHz channel size is replaced by a much larger 192 MHz channel which potentially can provide data rates up to 10 Gbps. Further, the current standard requires equipment to support a relatively new form of active queue management (AQM) referred to as delay-based AQM. Given that more than 50 million households (and climbing) use cable for Internet access, a clear understanding of …

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Scalable Synthesis And Energy Applications Of Defect Engineered Nano Materials, Mehmet Karakaya Dec 2015

Scalable Synthesis And Energy Applications Of Defect Engineered Nano Materials, Mehmet Karakaya

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Nanomaterials and nanotechnologies have attracted a great deal of attention in a few decades due to their novel physical properties such as, high aspect ratio, surface morphology, impurities, etc. which lead to unique chemical, optical and electronic properties. The awareness of importance of nanomaterials has motivated researchers to develop nanomaterial growth techniques to further control nanostructures properties such as, size, surface morphology, etc. that may alter their fundamental behavior. Carbon nanotubes (CNTs) are one of the most promising materials with their rigidity, strength, elasticity and electric conductivity for future applications. Despite their excellent properties explored by the abundant research works, …

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Understanding How Synthetic Organic Chemistry Graduate Students Navigate Scifinder, Lindsey Whitfield Cain Dec 2015

Understanding How Synthetic Organic Chemistry Graduate Students Navigate Scifinder, Lindsey Whitfield Cain

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Students pursuing a Ph.D. degree are expected to contribute research to their field, for which the success depends, in part, on their ability to find, interpret, and use scholarly information from the primary literature. However, studies from the information sciences show that graduate students from a variety of fields, including the sciences, frequently struggle to comprehensively search their respective dissertation topics because of insufficient prior content knowledge and lack of guidance from their disciplinary community. This body of literature is consistent with the results of my previous research of chemistry graduate students’ laboratory decision-making processes. Specifically, that study showed their …

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Development, Validation, And Application Of Analytical Methods For Characterizing Adsorbed Protein Orientation, Conformation, And Bioactivity, Aby Thyparambil May 2015

Development, Validation, And Application Of Analytical Methods For Characterizing Adsorbed Protein Orientation, Conformation, And Bioactivity, Aby Thyparambil

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The structure and bioactivity of adsorbed proteins are tightly interrelated and play a key role in their interaction with the surrounding environment. These factors are of critical importance in many biotechnological applications. However, because the bioactive state of an adsorbed protein is a function of the orientation, conformation, and accessibility of its bioactive site(s), the isolated determination of just one or two of these factors will typically not be sufficient to understand the structure-function relationships of the adsorbed layer. Rather a combination of methods is needed to address each of these factors in a synergistic manner to provide a complementary …

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Decision Environments To Encourage More Sustainable Infrastructure Outcomes, Earl Shealy May 2015

Decision Environments To Encourage More Sustainable Infrastructure Outcomes, Earl Shealy

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Physical infrastructure (i.e. roads, pipelines, airports, dams, landfills, and water treatment systems) contributes directly to sustainability outcomes such as energy and water use and climate changing emissions. The infrastructure built today will likely impact future generations for many years. Planning, design and development decisions about infrastructure are critical to the future performance of these systems. Such decisions about infrastructure are complex with multiple variables, alternative options, and design stages. To manage decisions that exceed cognitive capacity to consider all options, decision makers often create mental shortcuts (heuristics), and accompanied errors (biases). The potential cognitive biases when dealing with complex decisions …

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The Contribution Of Indigenous Ecological Knowledge In Conservation Of Enguserosambu Community Forest, Tanzania, Agnes Sirima May 2015

The Contribution Of Indigenous Ecological Knowledge In Conservation Of Enguserosambu Community Forest, Tanzania, Agnes Sirima

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Community managed forests constitute a significant proportion of the world's forests, however, little is known regarding their condition or the details of how they are managed. Documented benefits of community managed forest include poverty alleviation and in some places a decrease in the rate of deforestation. Although some community based forests do not satisfy the IUCN definition of a protected areas, they provide valuable long term sustainability of forest products and many are also rich in biodiversity and support landscape conservation strategies. Forests are also home to many cultures including the indigenous people. Indigenous communities surrounding forest areas and other …

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Values Assigned To National Parks By Hispanics In The United States: Castillo De San Marcos And Fort Matanzas Nm And Great Smoky Mountains Np, Carla Mora-Trejos May 2015

Values Assigned To National Parks By Hispanics In The United States: Castillo De San Marcos And Fort Matanzas Nm And Great Smoky Mountains Np, Carla Mora-Trejos

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The integrity of Parks and Protected Areas (PPA) depends on management that acknowledges their position as part of the socio-cultural context and demonstrates awareness and attention to ethnic and racial dimensions of the communities adjacent to these areas. The Unites States National Park Service has dedicated resources and effort to determine ways to keep units in the national park service relevant in a changing world. The fastest growing and second largest demographic in the Unites States is the Latino or Hispanic population. Very little has been published about this rapidly growing population of Latin Americans residing in the United States …

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Ph Sensing And Imaging With Nanoparticles And Implantable Films, Fenglin Wang May 2015

Ph Sensing And Imaging With Nanoparticles And Implantable Films, Fenglin Wang

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pH is a very important parameter in biological systems. Monitoring pH in situ may provide useful information for studying pH regulated cellular events, diagnosing diseases and assessing treatment efficacy. Various strategies have been introduced for developing pH sensors. However, it is still challenging to monitor pH in biological systems with high specificity, especially through thick tissue. In this dissertation, we describe three types of pH sensors which are used to noninvasively monitor pH in living cells, monitor and map bacterial growth caused pH variation through thick tissue with minimal autofluorescence background. In Chapter 2, a pH nanosensor with high specificity …

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Biophysical Interaction Between Nanoparticles And Biomolecules, Slaven Radic Apr 2015

Biophysical Interaction Between Nanoparticles And Biomolecules, Slaven Radic

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In the last two decades nanotechnology market has undergone remarkable growth. Breakthroughs in nanomaterial synthesis increased diverse nanomaterials production and subsequently their application. Owing to its large surface to volume ratio and remarkable physical properties not seen in the bulk materials, nanoparticles are finding emerging use in industry and medicine. Hence, it is expectable that at some point these nanomaterials will end up released into the environment and interact with bio systems. The purpose of this dissertation is to elicit implications of nanomaterial transformation once it gets inside biological milieu.

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