Digital Commons Network^™

Effective Magnetic And Electric Response Of Composite Materials, Mona Hassan Alsaleh

Doctoral Dissertations

Metamaterials (MMs) are nanocomposite materials consisting of metal-dielectric resonators much smaller in size than the wavelength of the incident light. Common examples of metamaterials are based on split ring resonators (SRRs), parallel wires or strips and fishnet structures. These types of materials are designed and fabricated in order to provide unique optical responses to the incident electromagnetic radiation that are not available in naturally existing materials. The MMs can exhibit unusual properties such as strong magnetism at terahertz (THz) and optical frequencies. Additionally, negative index materials (NIMs) can provide negative index of refraction which can be used in many applications …

Electrical Characterization Of Graphene And Nanodiamond Nanostructures, A Z M Nowzesh Hasan

Doctoral Dissertations

The electrical characterization on two-dimensional carbon-based graphene and nanodiamond materials was performed to improve charge transport properties for the label-free electrical biosensors. The charge transport in solution-gated graphene devices is affected by the impurities and disorders of the underlying dielectric interface and its interaction with the electrolytes. Advancement in field-effect ion sensing by introducing a dielectric isomorph, hexagonal boron nitride between graphene and silicon dioxide of a solution-gated graphene field-effect transistor was investigated. Increased transconductance due to increased charge carrier mobility is accompanied with larger ionic sensitivity. These findings define a standard to construct future graphene devices for biosensing and …

Nanoparticle Catalytic Enhancement Of Carbon Dioxide Reforming Of Methane For Hydrogen Production, Nicholas Groden

Doctoral Dissertations

The U.S. produces 5559.6 million metric tons of carbon dioxide annually, of which 21% is produced by industrial processes. Steam reforming, an industrial process that accounts for 95% of all hydrogen production in industry, produces 134.5 million metric tons of carbon dioxide or around 11% of the total carbon dioxide produced by industry. This carbon dioxide is then either emitted or goes through a sequestration process that accounts for 75% of the plant's operational costs. An alternative reaction to steam reforming is dry reforming, which utilizes carbon dioxide rather than emitting it and can be used in conjunction with current …

Understanding Why Students Take Industry-Based Credentialing Examinations: Instrument Development And Pilot Study, Jennifer H. Lawrence

Doctoral Dissertations

Educational credentialing is complicated for students with the addition of industry-based credentialing (IBC) in traditional academic and career and technical fields (Bahr, 2015; Lumina Foundation, 2015; Xu & Ran, 2015). Human Capital Theory and Cognitive Engagement Theory framed this study which looked at IBC training from the student point of view (Grisham, 2013; Saldana, 2016; Walters, 2004). The body of literature on credential training is sparse and largely focused on institutional policy rather than student perception and participation (Bahr, 2015; Xu & Ran, 2015). There is evidence that salaries are positively correlated with IBCs and studies show that employers pay …

Multidimensional Feature Engineering For Post-Translational Modification Prediction Problems, Norman Mapes Jr.

Doctoral Dissertations

Protein sequence data has been produced at an astounding speed. This creates an opportunity to characterize these proteins for the treatment of illness. A crucial characterization of proteins is their post translational modifications (PTM). There are 20 amino acids coded by DNA after coding (translation) nearly every protein is modified at an amino acid level. We focus on three specific PTMs. First is the bonding formed between two cysteine amino acids, thus introducing a loop to the straight chain of a protein. Second, we predict which cysteines can generally be modified (oxidized). Finally, we predict which lysine amino acids are …

The Effects Of Pair Budget Goal Difficulty And Pair Identity On Decision-Making And Performance, Chaoping Li

Doctoral Dissertations

Mixed incentive compensation structures have been widely studied in the accounting literature (e.g., Tian et al. 2017; Dekker et al. 2012, Rothenberg 2011; Hwang et al. 2009). However, the findings in the literature as to the effectiveness of mixed incentives are not consistent. The inconsistency in the mixed incentives literature may be due to the various levels of social dilemma embedded in the research setting of the studies. Therefore, I experimentally investigated two factors that may reduce the embedded social dilemma issue and improve the effectiveness of mixed incentive compensation. In this study, student participants were assigned to pairs to …

Electromagnetic Wave-Matter Interactions In Complex Opto-Electronic Materials And Devices, Raj Kumar Vinnakota

Doctoral Dissertations

This dissertation explores the fundamentals of light-matter interaction towards applications in the field of Opto-electronic and plasmonic devices. In its core, this dissertation attempts and succeeds in the the modeling of light-matter interactions, which is of high importance for better understanding the rich physics underlying the dynamics of electromagnetic field interactions with charged particles. Here, we have developed a self-consistent multi-physics model of electromagnetism, semiconductor physics and thermal effects which can be readily applied to the field of plasmotronics and Selective Laser Melting (SLM). Plasmotronics; a sub-field of photonics has experienced a renaissance in recent years by providing a large …

Engineered Coating Of Natural Fibers And Oil-Water Interfaces With Self-Assembly Of Clay Nanotubes, Abhishek Panchal

Doctoral Dissertations

Taking into consideration two different types of surfaces, this dissertation proposes techniques to coat the surface of natural fibers and oil-water interfaces by spontaneous self-assembly of halloysite clay nanotubes. The material of choice, halloysite clay, is a widely available natural resource and can be used after minimal processing. In regards to chemical composition, halloysite clay resembles aluminosilicate mineral kaolin; physically, a defect in the crystal structure ordering causes the sheets of kaolinite to roll into halloysite nanotubes. The dimensions of halloysite nanotubes are dependent on the source, but generally vary from 200 nm to 3 µm in length, 100-150 nm …

Characterization Of Nanomaterials For Thermal Management Of Electronics, Amit Rai

Doctoral Dissertations

Recently, there has been a growing interest in flexible electronic devices as they are light, highly flexible, robust, and use less expensive substrate materials. Such devices are affected by thermal management issues that can reduce the device’s performance and reliability. Therefore, this work is focused on the study of the thermal properties of nanomaterials and the methods to address such issues. The goal is to enhance the effective thermal conductivity by adding nanomaterials to the polymer matrix or by structural modification of nanomaterials. The thermal conductivity of copper nanowire/polydimethylsiloxane and copper nanowire/polyurethane composites were measured and showed more than threefold …

Development And Cost-Effectiveness Of A Malnutrition Screening Program In A Skilled Nursing Setting, Emily Salas-Groves

Master's Theses

Malnutrition increases the cost of healthcare and is commonly unrecognized and untreated. These facts are especially true for healthcare settings that provide care to the elderly. Research emphasizes the need for malnutrition prevention in extended care facilities such as skilled nursing facilities (SNFs) so that patients receive timely and appropriate intervention(s).

The purpose of this study was to retroactively screen SNF patients using four alternative malnutrition screening tools and to compare results to those from the facility screening tool. A second purpose was to estimate differences in potential Medicare reimbursement based on the number of patients identified at risk for …

Metal Segregation During The Solidification Of Titanium-Aluminum Alloys For 3d Printing Applications, Jwala Parajuli

Master's Theses

Titanium-Aluminum alloys are one of the widely used alloys in multiple engineering applications. They are highly preferred in Selective Laser Melting (SLM) processes due to their low density, high melting temperature, and good strength. Segregation occurs during the solidification of most alloys and produces a non-uniform distribution of atoms. In SLM, segregation may depict the type of adhesion between the two deposited interfacial layers and the strength between the interphase between an already solidified layer and a new one, and overall, the quality of the printed part. In order to avoid segregation, the understanding of the segregation behavior at atomistic …

Phytonutrient Intake And Body Composition Color Correlations, Ryan Orgeron

Master's Theses

This study evaluated the role of phytonutrient intake on body composition. Both the quantity and types of phytonutrients in diets were analyzed. Fifty (50) subjects (15 males; 35 females) from Thibodaux, Louisiana, were randomly selected to participate. All participants completed three 24-hour food recalls to gather intake data (food and calorie intake). The phytonutrient index (PI) was an established formula used to calculate the percentage (%) of the diet comprised of phytonutrient rich foods. Three different body assessment tools were used to determine body adiposity (body mass index [BMI], waist circumference, and fat percentage).

Participants who met healthy standards for …

Design And Fabrication Of Fdm 3d Printed Strain Sensors, Austin Smith

Master's Theses

As technology related to virtual reality, prosthetics, and robotics advances there appears a need for better sensor technology to augment these systems. In particular, many of the systems must interphase with the human body or the environment while maintaining large amounts of mobility and flexibility. This creates the demand for flexible electronics in particular flexible strain sensors to monitor movement. The work presented here explores the feasibility of commercially available elastic filament and desktop Fused Deposition Modeling (FDM) 3D printing as a simple and cost-effective route to develop flexible single-axis strain sensors. 3D printing allows for the rapid production and …

Assessing The Adequacy Of The Rate Based System Of Enteral Nutrition Infusion In The Icu Of A Community Hospital, Callie Betman

Master's Theses

The rate based system for delivering enteral nutrition has been found to result in an average delivery of 60-65% of estimated energy and protein needs in ICU patients. Interruptions in tube feedings for surgery, intolerances, and turning/bathing cause underfeeding as the rate based system does not allow the rate to be adjusted for any lost volume. At Northwest Hospital, protocol is to calculate the hourly tube feeding rate over 20 hours, and run over 24 hours, in order to adjust for an expected 4 hours of interruptions per day; however, the effectiveness of this protocol has not been studied. The …

Finding Our "Happily Ever After": How Poor Fairy-Tale Parenting Breeds A Better Child, Brandie Crain

Master's Theses

This thesis shows how problematic parenting in fairy tales can have a positive influence on children by building their independence and giving them a more realistic and less naïve outlook on life. Fairy tales should not only be present in the childhood of our lives, but throughout every season. Problematic parents are prevalent throughout fairy tales, catalysts for the harm which inevitably comes to their children. However, this harm is usually not their end, as they are forced to self-parent. “All Fur,” “Cinderella,” “Snow White,” “The Juniper Tree,” and “Hansel and Gretel” create the idea that parents are sometimes a …

A Complete Characterization Of Near Outer-Planar Graphs, Tanya Allen Lueder Genannt Luehr

Doctoral Dissertations

A graph is outer-planar (OP) if it has a plane embedding in which all of the vertices lie on the boundary of the outer face. A graph is near outer-planar (NOP) if it is edgeless or has an edge whose deletion results in an outer-planar graph. An edge of a non outer-planar graph whose removal results in an outer-planar graph is a vulnerable edge. This dissertation focuses on near outer-planar (NOP) graphs. We describe the class of all such graphs in terms of a finite list of excluded graphs, in a manner similar to the well-known Kuratowski Theorem for planar …

Differences In Leadership Behaviors Of Principals And Success In The School Turnaround Processes, Annette Lee

Doctoral Dissertations

The purpose of this study was to examine leadership behaviors of principals associated with public elementary schools that were either in the school turnaround process or had already transitioned out of school academic turnaround from 2011 through 2016. Transformational leadership guided the study to determine whether leadership behaviors differed among leaders of schools associated with academic failure. School accountability data were initially gathered through the Louisiana Department of Education website. Academically unsuccessful schools (AUS) were identified. Schools that were deemed failing at least one time during the 2012-2016 timeframe were grouped as follows: (a) Group A consisted of two schools …

Developing An Assay To Quantify Antigen-Specific Igy In A Long-Lived Seabird, Anna Louise Mccarter

Master's Theses

To maximize parental fitness, life history theory predicts that short-lived species will prioritize reproductive efforts over self-maintenance functions. The opposite is predicted for long-lived species, which ought to invest heavily in immune defenses, particularly those of the acquired immune system. Yet, most of our current understanding of immune system function has been from investigations of short-lived model species. Little is known about the induction and maintenance of immunological memory in wild species, and in particular, long-lived, wild species. This is due in part to limited availability of species-specific secondary antibodies for use in serological studies of non-model species. Moreover, commercially …

The Influence Of Regional Stereotypes In Employee Selection, Brittani E. Plaisance

Doctoral Dissertations

An individual’s social world is understood through categorizing other people as those within an individual’s own in-group and those without, or the out-group. Social cognitive theory suggests that individuals make decisions in social settings based on implicit social comparisons between these groups. Stereotypes are oversimplified beliefs about the members of a specific group and discrimination is the behavioral outcome based on held stereotypes. Discrimination based on race, ethnicity, age, and gender has dominated research in the realm of employee selection for the last twenty years. Researchers have demonstrated perceived and actual differences in various attributes by region of the United …

Development Of A Longitudinal Imaging System For Murine Brain Injury Models, Chelsea D. Pernici

Doctoral Dissertations

Following traumatic brain injury (TBI) and stroke, secondary injury cascades can lead to axonal damage and persistent microglia activation, respectively, in subcortical regions of mice. Current techniques, such as diffusion tensor imaging (DTI) and histology are used to observe features related to damage, but DTI lacks cellular resolution and histology is conducted on fixed tissue, preventing longitudinal studies in the same mouse. The combination of cranial windows and multiphoton microscopy (MPM) is used to image cells in the upper layers of the mouse cortex, but resolution rapidly degrades with imaging depth, making it difficult to observe white matter and subcortical …

Higher-Order Accurate Finite Difference Method For Thermal Analysis In Double-Layered Solid Structures -- Gradient Preserved Method, Yun Yan

Doctoral Dissertations

Layered structures have appeared in many systems such as biological tissues, micro-electronic devices, thin films, fins, reactor walls, thermoelectric power conversion, thermal coating, metal oxide semiconductors, and thermal processing of DNA origami nanostructures. Analyzing heat transfer in layered structures is of crucial importance for the design and operation of devices and the optimization of thermal processing of materials. There are many numerical methods dealing with the layered structures or interface problems. The existing numerical methods such as the immersed interface method and the matched interface boundary method, if using threegrid points across the interface, usually provide only a second-order truncation …

Smoothed Particle Hydrodynamics For Computational Fluid Dynamics, Wennan Ma

Doctoral Dissertations

Smoothed particle hydrodynamics (SPH) is a simple and effective numerical method that can be used to solve a variety of challenging problems in computational mechanics. It is a Lagrangian mesh-free method ideal for solving deformation problems. In the SPH method, the state of a system is represented by a set of particles, which possesses individual material properties and interact with each other within a specific range defined as a support domain by a weight function or smoothing function. SPH features flexibility in handling complex flow fields and in including physical effects.

In theory, the basic concept of the SPH method …

Validation Of Spatial Hysteresis As The Internal Damping Mechanism In An Unmanned Micro Aerial Vehicle Model, Ashleigh Chambers

Doctoral Dissertations

Unmanned aerial vehicles have been an area of interest in both research and industry for the past several decades. Advancements in technology have allowed such aircraft to decrease in size. UAVs are less expensive than traditional aircraft and are less restricted in where they can fly due to their compact size, leading to shifts in the way infrastructure, agriculture, and transportation surveillance and operations are handled.

However, small aerial vehicles and flexible, composite ones are more susceptible to crashes. This has led to an increased interest in methods to control such aircraft. In order to accurately model for a composite, …

Development And Analysis Of Engineered Brain Cell Microenvironments Mimicking Healthy And Diseased Neuronal Circuits, Kahla St. Marthe

Doctoral Dissertations

Astrocytes and microglia (glial cells) are active elements of the brain maintaining numerous homeostatic functions. Disturbances result in worsening of neuro-inflammation, traumatic brain injury, and various stages of brain tumors. Glial cells contribute to homeostasis for dynamic second messengers in the CNS, including intracellular calcium concentration ([Ca2+] i). Calcium is a central secondary messenger which signals for example, through the N-methyl-D-aspartate (NMDA) glutamate receptor on the neuronal membrane. A large, dynamic Ca2+ influx ensues after glutamate binds to the NMDA receptor. This influx initiates several molecular mechanisms within the cell. Disturbances in calcium homeostasis can lead to neurological diseases such …

Wastewater Pipe Condition And Deterioration Modeling For Risk-Based Decision-Making, Greta J. Vladeanu

Doctoral Dissertations

The dissertation research work described here has four primary objectives: (1) the development of a comprehensive wastewater pipe condition rating model that incorporates a large number of environmental, structural, and hydraulic parameters of the pipe; (2) the development of a wastewater pipe deterioration model used to predict future overall condition states of the pipe, as well as determining the probability of failure at any given age of the pipe; (3) the development of a comprehensive consequence of failure model that assesses the consequence of wastewater pipe failure using economic, social, and environmental cost factors; and (4) the development of a …

Investigating The Role Of Operating Parameters And Surface Treatments Of Carbon Based Electrodes In Capacitive Deionization, Md Ashique Ahmed

Doctoral Dissertations

This research focused on studying salt ion removal behavior and regeneration of electrodes used in capacitive deionization (CDI). CDI is a novel deionization technology that utilizes electrochemical processes to extract ions from water and either hold them electrostatically on the electrode surface or trap them in a double layer formed next to surface of electrodes. The use of porous carbon materials as electrodes in CDI enhances ion removal capacity because of availability of high surface area, conductivity, porosity, non-corrosive behavior, and other favorable properties. Experiments were conducted with a synthetic NaCl solution prepared in the laboratory. The first part of …

Experimental And Computational Studies On The Reinforcement Effect Of Smooth Cord Grass (Spartina Alterniflora) On Erosion In Louisiana Coastal Marsh Creation Project, Sujan Baral

Master's Theses

Louisiana coastal saltmarshes are disappearing at an exponential rate. Even though several researches indicate that vegetation on coastal marshes protect the coast from erosion by providing soil reinforcement, wave buffering, sediment trapping and overall hydrologic regime control, the complex nature of coastal erosion process makes it too difficult to quantify the erosion resistance provided by vegetation. This research is focused on the study of soil binding ability provided by smooth cord grass, Spartina alterniflora, flourishing in dredged soil of Sabine Refuge Marsh Creation Project (CS-28) in Louisiana.

Field vane shear test was conducted to obtain the in-situ un-drained shear strength …

A Semi-Supervised Feature Engineering Method For Effective Outlier Detection In Mixed Attribute Data Sets, Girish Srivatsa Rentala

Master's Theses

Outlier detection is one of the crucial tasks in data mining which can lead to the finding of valuable and meaningful information within the data. An outlier is a data point that is notably dissimilar from other data points in the data set. As such, the methods for outlier detection play an important role in identifying and removing the outliers, thereby increasing the performance and accuracy of the prediction systems. Outlier detection is used in many areas like financial fraud detection, disease prediction, and network intrusion detection.

Traditional outlier detection methods are founded on the use of different distance measures …

A Model Of The Relationship Between Performance Feedback And Goal Setting: A Consideration Of, Affective Cognitive, And Psychological State Effects, Ann-Marie R. Castille

Doctoral Dissertations

Performance feedback meetings are often dreaded, perceived to be worthless, and de-motivating for employees (Culbertson, Henning, & Payne, 2013; Rock, 2008). Although they are intended to enhance motivation and performance (Erez, 1977; Kim & Hamner, 1976), over a third of feedback interventions backfire, resulting in lower rather than higher performance (Kluger & DeNisi, 1996). Motivational theories (i.e., behavioral motivation theory, organizational justice theory, reversal theory, goal setting theory, and theory of planned behavior) provide complementary explanations for the impact of feedback on performance. However, these explanations have not been subjected to comprehensive empirical scrutiny. The purpose of this dissertation was …

The Effect Of Horizontal Inequity, Capacity For Budget Slack, And Severity Of Peer Overstatement On Managerial Reporting Behavior, Yiwen Li

Doctoral Dissertations

An ongoing stream of accounting research indicates that non-pecuniary factors significantly affect employees’ reporting behavior. This study investigates the behavioral effects of three non-pecuniary factors - horizontal pay inequity, capacity for budget slack, and severity of peer overstatement. The behaviors of interest are the employees’ level of honesty and whether or not they report a peer that is overstating.

In the experiment, participants acted as division managers who request funding from the owner of a fictitious company to produce certain parts. In each period, participants were paired with a different fictitious peer and were required to make two decisions under …