Digital Commons Network^™

Analysis And Mitigation Of Common-Mode Behavior In Hybrid Vehicle Applications, Michael R. Hayashi

Open Access Theses

Modeling techniques to predict common-mode (CM) current in an electric drive intended for a hybrid vehicle are examined. A particular focus is on the derivation of a common-mode equivalent circuit (CMEC) in which machines, cables, and passives are represented by their passive coupling paths to ground and power electronic devices are replaced by equivalent voltage sources. The interconnection of components is accomplished using a judicious selection of a reference point used to define CM voltage. Circuit-based simulation results are presented for a system consisting of a permanent magnet generator coupled to an active rectifier that is providing power to an …

Performance Augmentation Of Compliance Based Morphing Wings Through Optimization And Non-Linearity, Ashwin Clement Henry

Open Access Theses

Conformal shape adaptation presents significant benefits in terms of increased aerodynamic efficiency for a wide range of flight conditions in addition to minimizing drag penalties via gap-less smooth shape profile change. Conformal shape adaptation in morphing wings can be achieved by distributed compliance and stiffness selectivity techniques. These morphing strategies yield light-weight monolithic structures by utilizing the multifunctionality offered by smart materials. The present thesis, therefore, attempts to enhance the performance of compliance based morphing wings by augmenting the stiffness characteristics through optimization of associated smart actuators and implementation of stiffness selectivity. These performance augmentation methods essentially attempt to improve …

Integrated Reservoir Characterization Of Potential Enhanced Oil Recovery Targets In Mature Basins: An Example From The Tar Springs Formation, Rock Hill Field, Illinois Basin, U.S.A., Timothy C. Henderson

Open Access Theses

Hydrocarbon reservoirs within the Illinois basin that have been extensively developed will soon reach the end of their production history without technological intervention. Although many of these mature fields have been waterflooded for decades and show a significant production decline, substantial amounts of residual oil remain in place making them ideal candidates for enhanced oil recovery (EOR) techniques. This research focuses on a producing field in southern Indiana that is being considered as a pilot study for surfactant-polymer chemical EOR. Using an integrated methodology that includes field geology, sedimentology/petrology, X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermal analysis (TGA), and scanning …

A Case Study On Monetary Fraud In A Cashless Economy, Swarnalakshmi M. Iyer

Open Access Theses

The payment market has many electronic instruments like cards and mobile phones competing with cash for market share. This thesis compares costs, involving two components: (i) the cost of implementing and maintaining an economy where the instrument can be used and, (ii) the losses suffered due to abuse of the payment instrument, for cash and card instruments. A case study on three countries Sweden, United States and India is conducted to survey variations in costs for cash and card instruments in economies that have varying extents of cash in circulation. Findings show that losses suffered due to abuse of cash …

Investigating The Degradation Of Amorphous Vitamin C In Polymeric Model Systems, Yahya Ismail

Open Access Theses

Vitamin C is an essential nutrient and a chemically labile compound found in natural foods and added as an ingredient to food products. A challenge for delivering vitamin C in foods is the tendency for the vitamin to degrade, which leads not only to a loss of nutritional quality but also to browning. Recent work has shown that vitamin C is likely in the amorphous solid state in many dry and intermediate moisture foods. Amorphous forms of an ingredient are inherently unstable and tend to crystallize over time. The study of vitamin C degradation in model amorphous polymeric matrices is …

Robust Flow Structures Of Turbulent Premixed Swirl Flames Experiencing Self-Excited Thermoacoustic Instabilities At Elevated Power Densities, Ryan B. Griffin

Open Access Theses

Historically one of the most expensive aspects of a gas turbine engine development enterprise has been large-scale experimental testing to quantify operating limits, and performance. To defray these costs, computational fluid mechanics and additional model-based design tools have been incorporated into the engine design process to better predict these characteristics of interest. However, even the most powerful supercomputers cannot resolve the interacting physics across the broad range of length-and temporal-scales present in actual engines. Therefore the computational cost must be reduced with modeling techniques that require a series of assumptions that rely on prior studies and similar empirical data sets. …

A Wearable Paper-Based Dermal Platform For Monitoring Perspiration, Vaibhav Jain

Open Access Theses

Consumer scale wearable devices have the potential to shift the healthcare paradigm from curative to preventive by allowing unobtrusive monitoring of important physiological parameters. Towards such a goal, this work presents a flexible and conformal, paper-based dermal platform (patch), for real time in-situ perspiration monitoring and quantification to aid in maintenance of hydration balance. Depending on the bio-metrics of the user and desired application, the wicking based platform having a spiral design with spokes/fingers of increasing length emanating from a central sweat collection region, can be customized in size and shape to sequentially trigger feedback (passive chemical color change on …

Analytics Protocol For Data-Driven Decision-Making In The Construction Industry, Ashwini Jain

Open Access Theses

Due to the unique nature of construction projects and the need for leaders in the business to have knowledge from multiple fields, it has become difficult for decision makers to confidently make choices in their complex working environment. Over time, data availability and computational power have both improved. Moreover, technological advancements from the past few years have overwhelmed the industry by generating a diverse amount data from various sources. This large amount of data makes it possible to find nuggets of information. However, in this digital era, collecting data is not the problem, but how to extract useful information is …

Facilitating Willingness To Communicate (Wtc): Communication For Academic And Social Life (Casl), Sarah Elizabeth Fehrman

Open Access Theses

Much has been written about learner Willingness to Communicate (WTC) in a second language. Multiple factors, including anxiety, motivation, personality, and context, have been identified as contributing to language learners’ willingness (or lack thereof) to attempt to communicate in a second language. Current research has identified these factors, yet there has been very little work done on how to facilitate WTC in learners or provide instructors with specific strategies and tools to utilize in the classroom. This thesis will undertake a historical overview of the development of WTC theory, examine the main antecedents to WTC, and finally examine current research …

Investigating The Effect Of Controlled Relative Humidity Storage On Amylopectin Retrogradation In Amorphous Starch, Starch:Gluten, And Wheat Flour Models, Kathryn Johnson

Open Access Theses

The development of crystallinity caused by amylopectin retrogradation has been correlated to staling in baked goods. Different amylopectin crystal polymorphs have been found in starches from different botanical sources and in amylopectin crystallized in different conditions. The amount of water in each polymorph has been documented. However, the molecular mechanism involved in bread staling and the role and distribution of water during starch retrogradation are still debated. The objective of this study was to determine whether water is incorporated into or expelled from amylopectin as crystal structures form during retrogradation using moisture sorption techniques and model starch, starch:gluten, and wheat …

An Assessment Of Reef Restoration Potential In Saginaw Bay, Lake Huron, Nicholas Ivars Kalejs

Open Access Theses

Historically, Saginaw Bay, Lake Huron had a complex of rocky reefs that functioned as preferred spawning habitat for various fish species, including Walleye (Sander vitreus) and Lake Whitefish (Coregonus clupeaformis). This reef system likely acted as a source of protection from egg predation, as well as of increased spawning diversity. Shifts in land use from forest to primarily agriculture and industry resulted in elevated runoff and sedimentation, leading to the loss of nearly all reef structure in Saginaw Bay. Coupled with overfishing and additional habitat degradation, these shifts precipitated dramatic declines of many fish species in the bay, including Walleye. …

"An Rbf Neural Network Approach In Radionuclide Identification Of Unknown Sources Utilizing Gamma-Ray Spectra", Pola-Lydia Lagari

Open Access Theses

At first, simulated γ-ray spectra for a set of 25 radionuclides, have been produced using the “Gamma Detector Response and Analysis Software (GADRAS)”. For each of these profiles (counts/kev vs energy), a Gaussian “Radial Basis Function” (RBF) network has been trained to represent it by an analytic closed form expression. Hence a library consisting of 25 RBF-networks, for the corresponding radionuclides, has been built. Secondly, a method for identifying the presence of radionuclides in the spectrum of an unknown source has been developed, assuming that the source contains a mixture of the considered radionuclides only. A linear combination of the …

Evaluation Of Alkalis, Buffers, And Complementary Fiber Feeds To Increase Digestibility And Performance In Feedlot Steers Fed Corn Stover, Nicholas Allan Lancaster

Open Access Theses

The use of dried distillers grains with solubles (DDGS) has been shown to limit fiber digestibility due to the inherent acidity of the feedstuff. Three studies were conducted to evaluate the effect of alkalis, buffers and complimentary fiber feeds on ruminal pH, fiber digestibility, and animal performance. The first study was conducted to determine the effectiveness of calcium hydroxide (StoverCal; Ca(OH)2) and/or roughage on diet digestibility, performance and carcass characteristics of steers fed 60% DDGS. The addition of StoverCal to low corn silage diets, or the addition of corn silage or corn stover to a 60% DDGS ration did not …

Design And Implementation Of A Content Searchable File System, Peng Li

Open Access Theses

Plenty of data is produced every second in the world. Having a huge amount of data, finding valuable data in a collection is much more difficult than before. There are many methods for data storage and retrieval. The file system is one of them and it is used by users on a computer. The current file system is based on the information storage concepts which is proposed in 1965. It manages the file metadata and provides the functionality that maps the file path to the data stored on the disk. However, it manages limited file metadata which is not able …

Restoration Of Hardwoods Through Conversion Of Non-Native Conifer Plantations, Jenny Lesko

Open Access Theses

Forest tree species such as American chestnut (Castanea dentata (Marsh.) Borkh) and oaks (Quercus spp.) have been heavily impacted by forest changes in the eastern US during the past century. American chestnut, a once-important eastern US forest tree, was decimated by chestnut blight fungus. Blight-resistant chestnut hybrids have been developed, however, and so restoration is now conceivable. Regeneration of oak is poor in eastern forests due to disturbance regime changes including lack of fire, deer overabundance, and competition with faster-growing species. Concurrently, large areas of mature introduced pine (Pinus spp.) plantations exist in the Midwest Central Hardwood Forest following their …

A Systematic Literature Review To Identify Best Practices For Communication In Virtual Teams, Arielle Mabon

Open Access Theses

Virtual teams are necessary for organizations to remain competitive in today’s global society, but the complexities of virtual team environments impart strain on virtual teams to perform key team activities. Although virtual teams are expected to deliver complex projects, training for communicating in virtual teams is often overlooked. This thesis was conducted using a systematic literature review of peer-reviewed articles from 2012-2017 to identify elements of communication that contributed to virtual team effectiveness and communication best practices that may be perceived as prescriptive content for virtual team communication training. The results of this study suggest that virtual team communication training …

Assessing The First And Last Mile Problem In Intercity Passenger Rail: Effects On Mode Choice And Trip Frequency, Lisa Lorena Losada Rojas

Open Access Theses

Passenger rail service is an integral part of intercity transportation networks, especially in areas where residents do not have access to cars or other intercity travel options. Some municipalities in the U.S. have experienced a decline in passenger rail service in recent years, which has prompted schedule reductions and entire abandonment of service in some cases. To improve the current intercity passenger rail service predicament, two alternatives can be considered: (1) improve the rail service itself (frequency, infrastructure, etc.) and (2) improve accessibility to the rail stations, which might be cheaper and more cost-effective overall. Improvements in accessibility can impact …

Mechanical Testing Of Semi-Solid Al-Mg Binary And 7050 Aluminum Alloys Using The Reheating-Cooling Method, Christopher James Mccleary

Open Access Theses

Elevated temperature tensile testing beyond the non-equilibrium solidus demonstrates the advantage of a new method called the Reheating-Cooling Method (RCM) for determining mechanical properties of Al-Mg binary alloys and cast alloy 7050 aluminum in the solid-liquid two phase mushy zone. Using the RCM, it is possible to achieve semi-solid tensile behavior with standard testing equipment and to retain a nonequilibrium casting microstructure, which is necessary to gain insight into hot tearing. Hot tearing, a virtually impossible to repair defect, is known to worsen with increasing Direct Chill (DC) cast ingot size. Further data gathered from mechanical testing of alloys within …

An Examination Of The Relationship Between Fitts' Law And Schmidt's Law, Jonathan Mckeeman

Open Access Theses

There are two prominent speed accuracy tradeoff relationships; Fitts’ Law and Schmidt’s Law. The Fitts tasks are considered to be spatially constrained, whereas the Schmidt tasks are temporally constrained. In this experiment the relationship between these two speed accuracy tradeoffs was examined. Previous studies have allowed for the hypothesis that these two laws may be related or share similar control processes. Through analysis of the previous literature on the subject I hypothesized that the two speed accuracy tradeoffs are unrelated and do not share a common control process. To test this hypothesis, participants performed both speed accuracy tradeoff tasks under …

A Method For Assessing And Predicting Water Quality Status For Improved Decision- Making And Management, Valeria Mijares

Open Access Theses

With the increasing population and demand for water, it is crucial to be able to assess its quality on a real-time basis and for predictive purposes. Water-quality Indices (WQIs) provide a means by which the water quality can be compared across space and time based on a composite indicator. Index and subindex values can be used to flag contaminants of concern, guide prioritization of management efforts, and for predictive purposes. In this study, subindex formulations for key water quality parameters were developed and enhanced to incorporate water quality targets and criteria. The enhanced subindex formulations were built into the Unweighted …

Cosmogenic Be-10 And Cl-36 In Magnetite, Angus Moore

Open Access Theses

Cosmogenic nuclides are widely used to assess catchment-averaged denudation rates, although the method has been largely limited to the nuclide 10Be in the target mineral quartz. This is because (a) quartz is resistant to weathering, (b) the production rate of 10Be in quartz has been extensively studied and is well-constrained, and (c) quartz may be reliably separated from other minerals and cleaned of meteoric 10Be. Denudation rates have remained difficult to measure in volcanic landscapes due to a lack of quartz and the rapid weathering of olivine and other alternative target minerals. This creates an interest in developing new target …

Influence Maximization Using Observational Data, Mohith Murlidhar

Open Access Theses

Influence maximization is the problem of finding a subset of nodes (seed nodes) in a network, such that by incentivizing these set of nodes, one maximizes the expected spread of influence in the network. This is an NP hard problem for which in the past, greedy algorithms and heuristics have been proposed for solving the problem. Most of these algorithms on this topic have focused on using information about the underlying graph and the edge probabilities, while running expensive controlled experiment simulations to find a solution to the influence maximization problem. These algorithms also accounted only for direct (or indirect) …

Simplified Model For Persistent Sliding Contact, Adarsh Patil

Open Access Theses

Numerous engineering applications involve one or more mechanical components that come into contact with each other during operation. Repetitive motions under contact can lead to fatigue and wear problems in the components. When designing such components, it is important to characterize and quantify the stresses and strains in the contacting elements. This can be achieved by numerical simulation of the process and by using one of the several contact formulations available in most finite element software programs. However, contact is an inherently non-linear problem which is rather challenging even for the best commercial software programs currently available. Often contact simulations …

Orbit Maintenance Strategies For Sun-Earth/Moon Libration Point Missions: Parameter Selection For Target Point And Cauchy-Green Tensor Approaches, Vivek Muralidharan

Open Access Theses

The libration point orbits in the Sun-Earth/Moon system are formed by concurrent gravitational influences by various celestial bodies, originating in a nonlinear dynamical regime. Coupled with the unstable nature of the orbit, the impact of any perturbations are expected to increase rapidly. The feasibility of a flow-based, Cauchy-Green tensor control strategy for station-keeping is examined. An orbit consistent with the mission objectives is selected for examination. The station-keeping process is stochastic, thus Gaussian random errors are introduced for simulation. The evolution of a velocity perturbation over time is monitored, beyond which the attainable state in the accessible region nearest to …

Effect Of A Brand Story Structure On Perceived Brand Image: The Mediating Role Of Immersion In A Brand Story Of A Luxury Hotel, Kyungin Ryu

Open Access Theses

Creating a more positive brand image in the competitive luxury hotel industry is an important goal for managers of such hotel brands. However, there are some skeptics as to the effectiveness of branding strategies of luxury hotels in developing a positive brand image for consumers. It has been suggested that consumers can be easily confused by the plethora of brand choices in the luxury hotel, making it difficult to remember a specific brand value differentiated from other choices. Based on psychographic research of luxury hotel consumers, these consumers have a tendency to prefer hedonic benefits stimulating emotional and symbolic benefits …

Experimental Investigation Of Inlet Distortion In A Multistage Axial Compressor, Razvan Rusu

Open Access Theses

The primary objective of this research is to present results and methodologies used to study total pressure inlet distortion in a multi-stage axial compressor environment. The study was performed at the Purdue 3-Stage Axial Compressor Facility (P3S) which models the final three stages of a production turbofan engine’s high-pressure compressor (HPC). The goal of this study was twofold; first, to design, implement, and validate a circumferentially traversable total pressure inlet distortion generation system, and second, to demonstrate data acquisition methods to characterize the inter-stage total pressure flow fields to study the propagation and attenuation of a one-per-rev total pressure distortion. …

Atmospheric Rural Community And Tourists' Experience -- China's Rural Tourism And Seniors' Quality Of Life, Jieyu Shi

Open Access Theses

The increasing percentage of aged populations in many parts of the world is an issue of global attention and significance. China is no exception and faced with a pressing challenge to find solutions for improving seniors’ quality of life. Extending the extant knowledge on the relationship between tourism and health, the current study posits that rural tourism, as a growing and popular form of leisure in China, can enhance the quality of life for both senior tourists and senior locals and proposes the concept of atmospheric community for rural tourism. This study develops the concept by investigating the elements of …

Responses Of Soil Greenhouse Gas Fluxes To Simulated Nitrogen Deposition And Rainfall Variability In A Tallgrass Prairie, Megan Scott

Open Access Theses

Climate change has altered precipitation regimes in many regions of the world. In the Midwestern United States, the intensity of precipitation events had increased, and the periods of drought between them have lengthened. Since the Industrial Revolution, nitrogen (N) deposition has increased and may further increase in response to growth in fossil fuel consumption and fertilizer use. Continuing changes in precipitation variability and N inputs will impact carbon (C) and N-cycling processes and atmospheric levels of greenhouse gases (GHG). Controlled by a variety of processes, soil GHG (CO2, N2O, and CH4) fluxes play a large role in determining atmospheric GHG …

Effects Of Dietary Pectin And Threonine Concentrations On The Growth Performance, Digestibility And Intestinal Morphology Of Broiler Chickens, Yu Shi

Open Access Theses

The experiment was conducted to determine the effect of dietary threonine (Thr) concentration and dietary pectin and the interaction effects of dietary pectin and dietary Thr concentrations on growth performance, nutrient digestibility and intestinal morphology of broiler chickens from d 7 to 21 posthatch. Ten diets with five levels of dietary Thr concentration of 5.7, 7.6, 9.4, 11.3, 13.2 g/kg, representing 60, 80, 100, 120, 140%, respectively, of the Thr requirement suggested by Ross Nutrition Supplement (2009), and two levels of dietary pectin (0 and 7%) were fed to broiler chickens from d 7 to d 21 posthatch in a …

Inclusion Of Antibiotic Alternatives In Feedlot Cattle Diets: Impact On Health Status, Cattle Performance And Meat Quality, Josey Pukrop

Open Access Theses

Although antibiotics are effective at diminishing the incidence of both bovine respiratory disease and digestive disorders and can promote growth in feedlot cattle, public scrutiny and concerns about antibiotic resistance are driving the cattle industry away from their use in production. Natural antibiotic alternatives derived from plants, bacteria and yeasts are increasing in popularity for use in cattle feeding operations.

In this thesis, the effect of a yeast cell wall product on performance and health status of receiving steers was examined and the effect of supplementing an essential oils blend on finishing cattle performance, liver abscess incidence, carcass characteristics and …