Digital Commons Network^™

A Dynamic Magnetic Equivalent Circuit Model For Design And Control Of Wound Rotor Synchronous Machines, Xiaoqi Wang

Open Access Dissertations

Recently, a new magnetic equivalent circuit (MEC) model was developed to support automated multi-objective design of wound-rotor synchronous machines (WRSMs). In this research, the MEC model and its application have been enhanced. Initial enhancement has focused on using the MEC model to explore machine design and control as a unified problem. Excitation strategies for optimal steady-state performance have been developed. The optimization is implemented in two phases. First, stator and field excitation at rated power is obtained as part of a WRSM design in which the objectives are to minimize machine mass and loss. Second, a map between current and …

Biophysical Studies Of Cholesterol In Unsaturated Phospholipid Model Membranes, Justin Adam Williams

Open Access Dissertations

Cellular membranes contain a staggering diversity of lipids. The lipids are heterogeneously distributed to create regions, or domains, whose physical properties differ from the bulk membrane and play an essential role in modulating the function of resident proteins. Many basic questions pertaining to the formation of these lateral assemblies remain. This research employs model membranes of well-defined composition to focus on the potential role of polyunsaturated fatty acids (PUFAs) and their interaction with cholesterol (chol) in restructuring the membrane environment. Omega-3 (n-3) PUFAs are the main bioactive components of fish oil, whose consumption alleviates a variety of health problems by …

Synthesis Of Graphene Nanomaterials And Their Application In Electrochemical Energy Storage, Guoping Xiong

Open Access Dissertations

The need to store and use energy on diverse scales in a modern technological society necessitates the design of large and small energy systems, among which electrical energy storage systems such as batteries and capacitors have attracted much interest in the past several decades. Supercapacitors, also known as ultracapacitors, or electrochemical capacitors, with fast power delivery and long cycle life are complementing or even replacing batteries in many applications. The rapid development of miniaturized electronic devices has led to a growing need for rechargeable micro-power sources with high performance. Among different sources, electrochemical micro-capacitors or micro-supercapacitors provide higher power density …

Effects Of Dip-Coated Films On The Properties Of Implantable Intracortical Microelectrodes, Salah Sommakia

Open Access Dissertations

The successful clinical use of implantable intracortical microelectrodes (ICMs) to treat certain types of deafness, blindness, and paralysis is limited by a reactive tissue response (RTR) of the brain. This RTR culminates in the formation of a tight glial scar and a loss of neuronal density around implanted ICMs, and is accompanied by a decrease in signal to noise ratio and an increase in impedance. While no comprehensive mechanistic understanding of the underlying biology is currently agreed upon in the field, a general consensus exists around a highly volatile acute RTR phase. During this acute phase, the electrical properties of …

The Mechanism And Timescales Of Soil Formation In The Hyper-Arid Atacama Desert, Chile, Fan Wang

Open Access Dissertations

The planetary surfaces that evolve in the near absence of water are strikingly different from surfaces where water is abundant, but their formation is poorly documented. This research is an in-depth exemplary work in the Atacama Desert in northern Chile to understand the soil formation in hyper-arid environments, as an analog for planetary surfaces such as the Mars. In detail, the basic mechanism regarding the source material, timescale, paleo-climatic settings and the role of crypto-biotic crusts have been investigated to constrain the Atacama soil development.

The geochemical, isotopic and mineralogical composition of atmospheric dust deposited along a West-East transect in …

"I Have Thought Proper To Inform The World": Reading Unconventional Testaments Of 18th-Century New England Women, Elyssa Tardif

Open Access Dissertations

Early New England women chose to pass down what they owned and valued: clothing, cupboards, pewter dishes, commonplace books, etc. But some women passed down something more: a written testament, which sought to shape public opinion in colonial New England. A "testament" usefully suggests a text that both serves as a witness to lived experience as well as the means by which the individual herself can frame the narrative for those who come after. This project aims to examine not only written records but also their audience: who were the heirs to these testaments and how were the records preserved …

Utilization Of Biomass Derived Furans In Value-Added Organics And Heterogeneous Oxorhenium Catalysts For Deoxydehydration Of Diols, Benjamin L. Wegenhart

Open Access Dissertations

As fossil fuels are depleted, there is a growing focus on renewable chemicals based on biomass materials, including both fuels and chemical feedstocks. Current methods for biomass utilization include biological conversion to produce ethanol and various thermochemical routes (gasification, pyrolysis, liquefaction, hydrothermal treatment, etc.). Furfural is one particular chemical that can be obtained from lignocellulosic biomass in good yields through the dehydration of sugar residues. It can be used as a feedstock for chemicals such as furan and THF, or as a platform molecule for making liquid fuels. The objective of this research is to investigate new pathways for the …

Gas-Phase Covalent And Non-Covalent Ion/Ion Chemistry Of Biological Macromolecules, John Robert Stutzman

Open Access Dissertations

Gas-phase ion/ion chemistry involves the interaction of oppositely charged ions inside of the mass spectrometer. During this gas-phase chemistry, particle transfer (i.e., proton and electron) or synthesis can occur at rapid reaction rates. Particle transfer represents a mature area of ion/ion chemistry, while selective covalent modification represents a fairly new area of gas-phase chemistry. Gas-phase covalent chemistry is based on traditional solution phase organic chemistry.

The work demonstrated in this dissertation greatly involves gas-phase covalent and non-covalent Schiff base chemistry on peptide and protein ions. The reagent dianion, 4-formyl 1,3-benzene disulfonic acid, has been used to covalently modify unprotonated primary …

Effects Of Amur Honeysuckle (Lonicera Maackii [Rupr.] Herder) Invasion And Removal On Native Vegetation And White-Footed Mice (Peromyscus Leucopus) In Mixed-Hardwood Forests Of Indiana, Joshua Michael Shields

Open Access Dissertations

The threat of non-native invasive species continues to compromise the ecological and economic integrity of our natural resources. Numerous investigators have documented the negative effects of invasive species on native biota. However, much work is still needed with regard to how invasive species spread in space and time, factors contributing to impacts on native biota within invaded ecosystems, and resultant effects of removing invasive species. In terms of invasion patterns, few studies have documented local patterns and rates of woody plant invasions, and even less is known about changes in spatial patterning and factors influencing structural characteristics (diameter and height) …

Design, Synthesis, And Evaluation Of Molecular Inhibitors For Biologically Relevant Enzymes, Sarah Emma St. John

Open Access Dissertations

The work in this thesis details the design, synthesis, and biological evaluation of molecular inhibitors for the inhibition of biologically relevant enzymes. The first three chapters of this thesis concern the polyphenol resveratrol and its inhibition of the quinone reductase 2 (QR2) enzyme. The work on this subject resulted in the complete design, synthesis, biological and structural evaluation of a second generation library of resveratrol analogues. From this work we identified a novel resveratrol analogue that inhibits QR2 in a previously unknown binding orientation. The fourth chapter of this thesis details the de novo design of molecules for the inhibition …

The Chemistry Of Flavonoids In Model Beverages And Human Milk, Brian Jay Song

Open Access Dissertations

Interest in the chemistry and stability of flavonoids in foods has been generated by countless epidemiological, in vitro, and in vivo studies that suggest a variety of potential health promoting effects of diets rich in flavonoids. Flavonoids have been shown to interact with multiple components in beverages including macromolecules, minerals, certain vitamins, and other flavonoids. Furthermore, environmental conditions including light exposure, elevated temperatures, and relative humidity have been shown to modify flavonoid stability. However, specific mechanisms, relative kinetics of degradation reactions and the impact of macromolecules in model beverages and biological fluids on flavonoid stability remain largely unknown.

Recently, interest …

Natural Genetic Variation Affecting Calcium Homeostasis, Rebecca Anna Replogle

Open Access Dissertations

Calcium (Ca) is essential for multiple functions within the body including skeletal health. The level of Ca in the serum is tightly regulated. During periods of habitual low Ca intake, the body senses a decrease in serum Ca and increases renal conversion of 25 hydroxyvitamin D (25(OH)D) to 1,25 dihydroxyvitamin D (1,25(OH)2D). 1,25(OH)2D acts through the vitamin D receptor (VDR) to increase intestinal Ca absorption, renal Ca reabsorption and skeletal Ca resorption. Efficient intestinal Ca absorption, especially during periods of low Ca intake, is critical for protecting bone mass. Ca absorption and its primary regulator, 1,25(OH)2D, are affected by both …

Synthesis Of Novel Isoprenoid Diphosphate Analogs As Chemical Tools To Investigate Protein Geranylgeranylation, Kayla Jo Temple

Open Access Dissertations

Many proteins require prenylation in order to be biologically functional. Some such proteins include the small Ras and Rho GTPase superfamilies, nuclear lamins A and B, and the kinesin motor proteins CENP-E and F. Prenyltransferase (PTase) inhibition is currently being explored as a possible treatment not only for cancer but for a wide variety of other diseases.

Clinical studies revealed that the effectiveness of farnesyltransferase inhibitors (FTIs) to treat Ras-dependent tumors is determined by which isoform of Ras is overactive. Unfortunately the majority of Ras-dependent tumors have a mutation in either the N- or K-Ras isoforms; both of these isoforms …

Management Of Potato Leafhopper And Maple Spider Mite On Nursery Grown Maples, Julia Prado Beltran

Open Access Dissertations

Potato leafhopper Empoasca fabae (Harris) (Homoptera: Cicadellidae) and maple spider mite Oligonychus aceris (Shimer) (Acarina: Tetranychidae) are important pests of maple trees. Investigations determined how insecticide use and fertilization impacted the abundance of E. fabae and O. aceris on `Red Sunset' red maple and `Autumn Blaze' Freeman maples. Bifenthrin applications directed against leafhoppers reduced damage to both cultivars, but increased O. aceris on Autumn Blaze. Using a threshold of one leafhopper per branch to trigger pesticide applications protected Red Sunset maples from leafhopper injury. It also prevented outbreaks of O. aceris on Autumn Blaze because few trees reached this density. …

Characterization Of Caxck31, A Bacterial Calcium/Proton Antiporter, Marc Robert Ridilla

Open Access Dissertations

To better understand a class of transporters known as Calcium/Cation Antiporters (CaCAs), the bacterial calcium/proton antiporter CAXCK31 was purified and characterized. New methods were developed for its heterologous overexpression and purification. These methods help to define stress responses to toxic membrane overproduction in E. coli and may be broadly applicable to studies of membrane proteins. The results from a variety of biochemical and biophysical experiments demonstrated that CAXCK31 exists as a dimer in the membrane and can be purified in the dimeric state. The methods used include chemical cross-linking, FRET, and SEC-MALS. In addition, various transport properties of CAXCK31, including …

Degree Program Changes And Curricular Flexibility: Addressing Long Held Beliefs About Student Progression, George Dante Ricco

Open Access Dissertations

In higher education and in engineering education in particular, changing majors is generally considered a negative event - or at least an event with negative consequences. An emergent field of study within engineering education revolves around understanding the factors and processes driving student changes of major. Of key importance to further the field of change of major research is a grasp of large scale phenomena occurring throughout multiple systems, knowledge of previous attempts at describing such issues, and the adoption of metrics to probe them effectively. The problem posed is exacerbated by the drive in higher education institutions and among …

Quantifying Crop Yield, Bioenergy Production And Greenhouse Gas Emissions From Cropland And Marginal Land Using A Model-Data Fusion Approach, Zhangcai Qin

Open Access Dissertations

Bioenergy is becoming increasingly attractive to many countries, but has sparked an intensive debate regarding energy, economy, society and environment. Biofuels provide alternative energy to conventional fossil fuels. However, the environmental impact of producing and using biofuel is a major concern to our society. This study is dedicated to quantifying and evaluating biofuel production and potential climate change mitigation due to potential large-scale bioenergy expansion in the conterminous United States, using model-data fusion approaches.

Biofuel made from conventional (e.g., maize (Zea mays L.)) and cellulosic crops (e.g., switchgrass (Panicum virgatum L.) and Miscanthus (Miscanthus × giganteus)) …

Welfare Impacts Of False Codling Moth Threatening California Oranges, Azza Mohamed Kamal Ahmed Mohamed

Open Access Dissertations

Welfare impacts of alternative pest management strategies of False Codling Moth (FCM) threatening California's oranges are examined. Different economic agents along the supply chain of fresh oranges and orange products in the United States are considered, including consumers, retailers, wholesalers, and growers. A partial equilibrium dynamic framework that accounts for supply response from the other US orange producing states is developed. Data for supply shocks (orange yield losses and control costs) are obtained from the Animal and Plant Health Inspection Service of the United States Department of Agriculture (APHIS).

FCM is not presently in the United States. If introduced to …

Silica Colloidal Crystals As Emerging Materials For The High-Throughput Sizing Of Proteins By Packed Capillary Electrophoresis, Nadine K. Njoya

Open Access Dissertations

Protein heterogeneity is currently one of the leading problems in formulation of therapeutic proteins. The effectiveness of therapeutic proteins is diminished when they exhibit heterogeneity due to aggregates and degradation by-products. Furthermore, guidelines set forth by the FDA require therapeutic proteins to have high stability as well as high purity. With development time on the order of years and costs incurred in the millions, pharmaceutical companies are investing more time in finding fast and efficient ways to screen for protein heterogeneity. Current methods such as native polyacrylamide gel electrophoresis (PAGE), size-exclusion chromatography (SEC) and capillary electrophoresis (CE) are time consuming, …

Invasive Silver Carp (Hypophthalmichthys Molitrix) Protein Hydrolysates- A Potential Source Of Natural Antioxidant, Sravanthi Priya Malaypally

Open Access Dissertations

Invasive silver carp (Hypophthalmichthys molitrix), continue to spread over the Mississippi River causing a great concern for the river ecosystem due to their impact on native fish species. To minimize the negative effects of silver carp, many strategies were implemented including using it for animal feed, as fertilizers or simply discarding them into waste. However, these fish are high in protein content, making them excellent starting material for protein-derived by-products. One alternative is to recover and modify the protein in the fish into bioactive food ingredient. In the functional/ nutraceutical food industry, there is high demand for antioxidant agents. In …

Store-Operated Calcium Entry And Its Function During Fertilization In Porcine Eggs, Chunmin Wang

Open Access Dissertations

In a variety of mammalian cells, the depletion of intracellular Ca^{2+ stores leads to Ca2+ influx across the plasma membrane though a process known as store-operated Ca2+ entry. It not only plays a critical role in the replenishment of the Ca2+ stores but it is also responsible for the maintenance of long-lasting high intracellular Ca2+ levels and sustaining repetitive Ca2+ oscillations. During fertilization a Ca2+ signal, which can take the form of a single or multiple Ca2+ elevations (depending on the species) is the universal trigger for the egg-to-embryo transition. For sustaining …}

Long-Term Disturbance Histories Of Managed And Natural Mixed-Hardwood Forests Of Central Indiana, Robert Charles Morrissey

Open Access Dissertations

Over the course of the last century, we have observed changes in forest composition and structure related to changes in disturbance regimes. Reduced frequency and severity of disturbance events has allowed for the ingrowth of shade-tolerant, mesophytic species into forest understories; the result is shifting species compositions and changes in forest structure. In some cases, the loss of masting species, such as oak (Quercus spp.) and hickory (Carya spp.), may also accompany a shift in forest function and further accommodate other species shifts among mammal, insect, and bird populations. Management efforts have been suggested as a possible means …

Structural Studies On The Rubella Virus Capsid Protein And Its Organization In The Virion, Vidya Mangala Prasad

Open Access Dissertations

Rubella virus is a leading cause of birth defects due to infectious agents. When contracted during pregnancy, rubella infection leads to severe damage in fetuses. Despite its medical importance, very little is known about the structure of the pleomorphic rubella virus as compared to its alphavirus relatives. The rubella capsid protein is a critical structural component of virions as well as a key factor in virus-host interactions. Three crystal structures of the structural domain of the rubella capsid protein have been described here. The polypeptide fold of the capsid protomer has not been observed previously. The capsid protein structure, along …

Utilizing Electron Microscopy And Spectroscopy Methods To Understand Water Structure And Water Doping, Lior Miller

Open Access Dissertations

Water is the second most common element in the universe and the most studied material on earth. Most of the studies concerning water are from the fields of chemistry and biology. Hence, the structure of water molecules and short range order and interactions are well characterized and understood. However, the collective arrangement of water molecules and the long range order are still missing. Understanding of this long range order in water is needed, as it is the key to many water activities.

To fill this gap, this study utilizes a new direct method for characterization of water in the vapor …

Control-Theoretic Decision Support For Mitigation Of Modeled Software Project Cost Overruns, Scott David Miller

Open Access Dissertations

Despite sixty years of practice, the production of software remains an endeavor that is difficult to manage according to a schedule. Control theory studies the ability to influence the dynamical behavior of systems to achieve desired behaviors or eliminate undesired behaviors. In this work, the management problem of software project schedule adherence is re-cast as a problem in control theory.

Below, a modeling framework is proposed for capturing the constraints and dependencies found in the arbitrary organization specific work-flows underlying software production. Combined with proposed models for productivity, defect introduction, and defect detection, the framework completes a method for producing …

Mispronunciation Detection For Language Learning And Speech Recognition Adaptation, Zhenhao Ge

Open Access Dissertations

The areas of "mispronunciation detection" (or "accent detection" more specifically) within the speech recognition community are receiving increased attention now. Two application areas, namely language learning and speech recognition adaptation, are largely driving this research interest and are the focal points of this work.

There are a number of Computer Aided Language Learning (CALL) systems with Computer Aided Pronunciation Training (CAPT) techniques that have been developed. In this thesis, a new HMM-based text-dependent mispronunciation system is introduced using text Adaptive Frequency Cepstral Coefficients (AFCCs). It is shown that this system outperforms the conventional HMM method based on Mel Frequency Cepstral …

Top-Down Interrogation And Characterization Of Biological Macromolecules, Yang Gao

Open Access Dissertations

Analytical mass spectrometry has been widely applied in the field of biomolecule identification and characterization. It provides fast, accurate and robust information relevant to the molecular mass, composition and structure of the target analytes.

This thesis is focused on the top-down analysis of various macrobiomolecules, nucleic acids and proteins, in the context of ion/ion reaction and gas-phase unimolecular dissociation. The first part of the thesis deals with gas phase fragmentation behavior of chemically modified oligonucleotides. Factors, such as the observation time-scale, the ion type and the energy deposition method, are explored using a quadrupole/time-of-flight mass spectrometer. Novel fragmentation pathway associated …

Wireless Sensors For Condition Monitoring Applications Operating In Complete Metallic Environment, Lokesh Anilkumar Gupta

Open Access Dissertations

Condition monitoring of machines is advantageous in predicting failure and estimating machine component lifetime. Continuous monitoring of parameters such as temperature, vibration, and strain using sensors and consequent data analysis can help in reducing machine downtime by taking corrective actions before failure. Various wireless and wired sensors may be attached to critical components such as bearings, gears, mechanical seals, shafts etc. for measurements. These sensors however are often inadequate solutions as wired sensors are dicult to mount on rotating components, especially in millimeter-size spaces that may exist in some of these components. Wireless sensors provide a viable solution for measurements …

The Genetic Architecture Of Juvenile Migration In Rainbow Trout (Oncorhynchus Mykiss), Benjamin Charles Hecht

Open Access Dissertations

Animal migrations play a critical role in the health and balance of ecological systems and in the evolution and diversification of species, and this is perhaps best displayed amongst salmonid fishes (salmon, trout, and char) who exhibit variation in the propensity to migrate both within and among species. Rainbow and steelhead trout (Oncorhynchus mykiss), members of the salmonid family of fishes, capture this variation throughout their native range. Some populations and ecotypes will remain resident in freshwater habitats throughout their life history; while others have the ability to embark on tremendous marine migrations. Those that migrate undergo a suite of …

Student Success: Approaches To Modeling Student Matriculation And Retention, Jien-Jou Lin

Open Access Dissertations

Every year a group of graduates from high schools enter the engineering programs across this country with remarkable academic record. However, as reported in numerous studies, the number of students switching out of engineering majors continues to be an important issue. Previous studies have suggested various factors as predictors for student retention in engineering. To assist the engineering students with timely advising early in their program, an effective prediction model of matriculation and retention in engineering that use available student data are highly desirable.

In the first part of this work, the author developed new prediction models of student retention …