Digital Commons Network^™

Molecular Dynamics Study Of Diffusion Of O2 Penetrates In Uncrosslinked Polydimethysiloxane (Pdms), Crosslinked Pdms, And Pdms-Based Nanocomposites, Varun Ullal

Graduate Theses and Dissertations

Molecular dynamics simulations are used to study diffusion of O₂ molecules in pure polydimethysiloxane (PDMS), crosslinked PDMS, and PDMS-based nanocomposites. The PDMS chains and penetrates are modeled using a hybrid interatomic potential which treats the Si-O atoms along the chain backbone explicitly while coarse-graining the methyl side groups and penetrates. By tracking the diffusion of penetrates in the system and subsequently computing their mean-squared displacement, diffusion coefficients are obtained. In pure PDMS models of varying molecular weight, diffusivity of the O₂2 penetrates is found to have an inverse relationship with chain length. Simulation models with longer chains …

Impacts Of Hard Stabilization On The Shore Of Yellowstone Lake, Yellowstone National Park, Wyoming, Usa, John Chandler Dennis

Graduate Theses and Dissertations

Discussions related to the adverse impacts associated with shore armor (i.e. seawalls and riprap) are a common topic within the coastal community. While many agree that the installation of these structures alters the shores geomorphic response, there is disagreement in the type and degree of response. Furthermore, studies that have delved into this topic have been conducted in numerous settings but have been confounded by a lack of data regarding shore morphologies prior to installation of these structures. At Yellowstone National Park, there is an opportunity to assess the impacts of shore armor quantitatively because the National Park Service requires …

Integrating Human Variables In Cross-Boundary Monitoring Of Aberdare Preserves In Kenya, Peter K. Njuguna

Graduate Theses and Dissertations

This research critically examines extant data systems and their linkage of scientific research to policy and public education in east African highland forest conservation preserves. The research indicates that the current state of data and monitoring systems in the region imposes substantial limitations on the ability to manage these preserves. Major outcomes of those constraints manifest in unprecedented cross-boundary pressure such as encroachment and conversion of forest to agriculture, increased human-wildlife conflicts, and constrained relations among primary stakeholders. Current monitoring is biodiversity focused within preserves and fails to capture human dimensions in adjoining areas across preserve boundaries. This study proposes …

Design And Implementation Of A Small Electric Motor Dynamometer For Mechanical Engineering Undergraduate Laboratory, Aaron Farley

Graduate Theses and Dissertations

This thesis set out to design and implement a new experiment for use in the second lab of the laboratory curriculum in the Mechanical Engineering Department at the University of Arkansas in Fayetteville, AR. The second of three labs typically consists of data acquisition and the real world measurements of concepts learned in the classes at the freshman and sophomore level. This small electric motor dynamometer was designed to be a table top lab setup allowing students to familiarize themselves with forces, torques, angular velocity and the sensors used to measure those quantities, i.e. load cells and optical encoders. The …

Design Of Orbital Maneuvers With Aeroassisted Cubesatellites, Stephanie Clark

Graduate Theses and Dissertations

Recent advances within the field of cube satellite technology has allowed for the possible development of a maneuver that utilizes a satellite's Low Earth Orbit (LEO) and increased atmospheric density to effectively use lift and drag to implement a noncoplanar orbital maneuver. Noncoplanar maneuvers typically require large quantities of propellant due to the large delta-v that is required. However, similar maneuvers using perturbing forces require little or no propellant to create the delta-v required. This research reported here studied on the effects of lift on orbital changes, those of noncoplanar types in particular, for small satellites without orbital maneuvering thrusters. …

Characterization Of Novel Histone H2b Mutants Associated With Chromosome Segregation Defects In Saccharomyces Cerevisiae, Thiruchelvam Rajagopal

Graduate Theses and Dissertations

Histones are small basic proteins that associate with DNA to form the basic unit of chromatin, the nucleosome. Histones H3 and H4 form a tetramer that is bound by two H2A-H2B dimers to form the histone octamer, to which approximately 146 bp of DNA wrap around to form the nucleosome. High resolution structural information and recent advances in the understanding of histone post-translational modifications have illuminated the many regulatory functions chromatin exerts in the cell, from the transcriptional control of gene expression to chromosome segregation. However, the specific role that histones play in these processes is not well understood. Previous …

Trauma At Akhetaten (Tell El-Amarna): Interpersonal Violence Or Occupational Hazard, Rebecca Marie Hodgin

Graduate Theses and Dissertations

The New Kingdom individuals excavated from the site of Akhetaten, modern day Tell el-Amarna in Middle Egypt, exhibit traumatic injuries relating to construction of the new city. This site is important for Egyptological and bioarchaeological interpretations because the city was only occupied for approximately 15 years. The cemetery provides an archaeological instant in history providing information on the individuals who lived, worked, and died at Akhetaten. A total of 233 individuals have been excavated and analyzed to date. The incidence of forearm fractures as chronic ulnae stress fractures instead of parry fractures are indicated by the presence of Schmorl's nodes, …

Disgust Sensitivity, Sexual Trauma History, And Female Sexual Functioning, Tara Mcgahan

Graduate Theses and Dissertations

Sexual dysfunctions are a common problem for women that negatively impact quality of life (Laumann, Paik, & Rosen 1999). A history of sexual trauma is associated with an increase in sexual difficulties (Neumann et al., 1996). One common reaction to unwanted sexual contact is disgust (Whealin & Barnett, 2010). However, the role of disgust in the relationship between sexual trauma and female sexual dysfunction has not been examined. This study explored how disgust and a history of sexual trauma related to different domains of sexual functioning (desire, arousal, lubrication, orgasm, satisfaction, and pain). Furthermore, this study assessed whether disgust mediated …

Comparison Of Sport Competitive Anxiety Levels Of Saudi Arabian National Team Athletes With And Without Disabilities In Competitions, Hassan Ahmad Halawani

Graduate Theses and Dissertations

Anxiety in sport is complex and can lead to a number of undesirable consequences such as burnout, performance difficulties, interpersonal problems, and injury. The purpose of this study was to compare whether significant differences existed in the levels of somatic anxiety, worry, and concentration disruption between individuals of the Saudi Arabian national team with and without disabilities in competitions. In addition, differences in somatic anxiety, worry, and concentration disruption were examined between athletes in an individual or team sport. The Sport Anxiety Sale (SAS-2, Smith et. al, 2006) was employed to measure the subscales of somatic anxiety, worry, and consternation …

Knowledge And Perceptions Of A Visual Communications Curriculum Unit In Arkansas Secondary Agricultural Classrooms: An Impact Of Experiential Learning, Kristin Mackenzie Pennington

Graduate Theses and Dissertations

Currently, a need exists for agricultural education programs to begin introducing new curriculum which will help meet the current and future needs of the agricultural industry. In 2010, the University of Arkansas Agricultural and Extension Education Department received grant funding for the development of curriculum relating directly to visual communications technology and its role in agricultural communications. Curriculum was developed and teachers across the state were asked to participate in implementing the program. The primary purpose of this study was to evaluate the knowledge levels of students prior to being taught agricultural communications curriculum, after the curriculum was taught, and …

Determining Multidimensional Gender: Development And Psychometrics Of A Measurement Instrument, Karyl Lounsbery

Graduate Theses and Dissertations

Gender identity is often thought of only as a binary construct, masculine and feminine, despite the fact that there are many people who do not see themselves as fitting this dichotomy (Rochman, 2006). Within the counseling field, it is likely that every counselor will eventually see someone who will be struggling with issues of gender identity (Ehrensaft, 2011). The introduction of the Arkansas Multidimensional Gender Scale (AMGS) will show there is a much broader scope of gender identity, more in line with the idea that all gender identities are normal and that there are as many gender identities as there …

The Relationship Between Chronic Ankle Instability And Functional Movement Impairment In Division I Female Athletes, Akihito Tajima

Graduate Theses and Dissertations

Lateral ankle sprains are the most common injury in athletics (Denegar & Miller, 2002; Ekstrand & Tropp, 1990). In addition, the recurrent rate of ankle sprains is as high as 80% (Smith & Reischl, 1986). Repetitive ankle sprains may lead to a phenomenon known as chronic ankle instability (Hertel, 2002). It has been theorized that there are two main attributions to chronic ankle instability: mechanical and functional instability (Monaghan, Delahunt, & Caulfield, 2006). The exact mechanism of chronic ankle instability is still unclear; however, recent studies focus on multiple factors rather than single measurements, in addition to functional testing. A …

A Proposal For A Writing Center And A Peer Tutor Training Course At Fayetteville High School, Katie Colleen Stueart

Graduate Theses and Dissertations

The following thesis is a proposal to begin a writing center at Fayetteville High School. The first part of the thesis document describes the research supporting the implementation of a writing center. The rest of the thesis provides the syllabus for the peer tutor-training course.

The Correlation Between Hip Abductor Strength And Functional Performance In Division I Female Collegiate Soccer Athletes, Caitlin Elizabeth Whale

Graduate Theses and Dissertations

Division I female soccer athletes have been documented to succumb to the greatest amount of lower extremity injuries, predominately ACL injuries. The risk for a lower extremity injury becomes greater when alterations to functional biomechanics are present. Specifically, the hip abductor strength has a crucial role in maintaining pelvic alignment. The purpose of this study was to determine if the hip abductor strength of a female athlete alters' biomechanics during functional performance. Thirty-two Division I female soccer athletes participated in this study (20+2yrs, 64.5+16.5kg, 166+14cm). Descriptive and anthropological statistics were recorded prior to participation. The athletes' isometric hip abductor strength …

Interpreting Judicial Behavior: How Content Analysis Of Language Reveals The Values, Philosophy, And Judicial Decision Making Style Of William H. Rehnquist, Megan Ryan

Graduate Theses and Dissertations

The intention of this analysis was to comment on the democratic nature of the United States Supreme Court by analyzing the decision making style of Supreme Court justice, William H. Rehnquist. There were two main research questions that drove this inquiry. First, was Rehnquist a consistent jurist? And second, which decision making model best exemplified his decision making style? In order to answer these questions, a computer assisted content analysis was conducted on the language Rehnquist used to describe his judicial philosophy and the justifications he made in opinions he wrote pertaining to personal privacy issues that came before the …

The Children Of Cain: Melville's Use Of The Abject Lineage From The Bible, Joseph Matthew Meyer

Graduate Theses and Dissertations

This study looks at how the abject lineage--consisting of Cain, Ishmael and Esau--has played an influential role in the works of Herman Melville. While many critics have exploredthe relationship between Melville and these characters in the past, my study proposes that the author was intimately aware of the differences between these characters and their relationship to God and used these differences to compose his works. Ultimately, Melville struggled with the need for an abject lineage, and this struggle manifests itself most prominently in the evolving silence of Christ from Mardi to "Bartleby."

Recombinant Protein Production In Bacillus Species, Isolation And Methionine Production In Methionine-Producing Microorganisms, Suwat Saengkerdsub

Graduate Theses and Dissertations

Linoleic acid isomerase (LAI) is the enzyme that converts linoleic acid to conjugated linoleic acids (CLAs) which appear to be capable of lowering cancer risk and enhancing immunity. There is an interest in developing commercial processes for the production of single isomers of CLA by biotransformation of LA using microbial cells and enzymes. However, the evaluation of these strains suggest that growth and LA isomerase production levels by these anaerobes are insufficient to support economic commercial production of single CLA isomers. A better alternative is to clone the isomerase gene and to generate new production strains using recombinant technology. Bifidobacterium …

Distribution And Control Of Herbicide-Resistant Italian Ryegrass (Lolium Perenne L. Ssp. Multiflorum Lam. Husnot) In Arkansas, James Walker Dickson

Graduate Theses and Dissertations

Italian ryegrass populations have evolved resistance to herbicides that producers rely on for weed control both in wheat and burn-down. The objectives of this research were to: test populations of Italian ryegrass from across Arkansas for resistance to glyphosate, diclofop, pinoxaden, and pyroxsulam; determine if there were any differences in control of 12 glyphosate-resistant populations in relation to glyphosate rate or application timing; determine the level of glyphosate resistance in one selected population versus a susceptible standard and a previously discovered glyphosate-resistant population; and determine the best options for controlling Italian ryegrass prior to planting crops. A total of 215 …

Insider Threat Mitigation Models Based On Thresholds And Dependencies, Harini Ragavan

Graduate Theses and Dissertations

Insider threat causes great damage to data in any organization and is considered a serious issue. In spite of the presence of threat prevention mechanisms, sophisticated insiders still continue to attack a database with new techniques. One such technique which remains an advantage for insiders to attack databases is the dependency relationship among data items. This thesis investigates the ways by which an authorized insider detects dependencies in order to perform malicious write operations. The goal is to monitor malicious write operations performed by an insider by taking advantage of dependencies. A term called `threshold' is associated with every data …

Pitch Perception In Changing Harmony, Cecilia Taher

Graduate Theses and Dissertations

The role of harmony in the definition of tonality provides theoretical framework for the hypothesis that harmonic context affects pitch perception. In tonal music, the stability of individual notes depends on the harmonic setting. It seems then reasonable to expect harmonically guided variations in the cognitive representation of tones. With the purpose of enhancing current models of pitch perception, this thesis proposes an empirical investigation of the effects of harmony on pitch sensitivity. In two experiments, nonmusicians performed a same/different discrimination task on two pitches (a reference tone RT and a comparison tone CT) that were embedded in a melody …

Playing Devil's Advocate: The Attractive Shakespearean Villain, Jonathan Montgomery Green

Graduate Theses and Dissertations

The characters of William Shakespeare have spawned countless words of critical interpretation inspired by the playwright's aptitude for fashioning intricate and conflicted figures. As a master character craftsman, Shakespeare is consistent in creating fascinatingly deep characters, and many of them have even gone so far as to generate entire literary archetypes. From the contemplative Prince Hamlet to the despicable yet charming John Falstaff, Shakespeare's characters remain eternal representatives of what any good character should be: interesting, provocative, and complicated.

However, among the playwright's most hypnotic figures are his villains, those characters whom audiences should by all counts detest but cannot …

Anxiety And Sleep Disorder Comorbidity: Affecting The College Students' Performances, Amanda Rhenee Grimes

Graduate Theses and Dissertations

The purpose of this study is to determine the effects that anxiety disorders and sleep disorders have on students' academic performance. The prevalence of both disorders is rising in the college student population. This study examines those who have been physician diagnosed with the one or both of the disorders and how the students' grade point average (GPA) is affected.

The National College Health Assessment was used for data collection; this survey assesses college students' health habits, behaviors, and perceptions. The sample was comprised of 57 institutions representing every region in the U.S. totaling 34,208 participants. Data was acquired through …

Development Of A Microfluidic Device Coupled To Microdialysis Sampling For The Pre-Concentration Of Cytokines, Randy Francisco Espinal Cabrera

Graduate Theses and Dissertations

A proof-of-concept microfluidic device combined with heparin-immobilized magnetic beads was created to concentrate cytokine proteins collected from microdialysis samples. Cytokines are known to be related to several diseases such as cancer, and Parkinson's diseases, so to be able to develop more effective diseases treatments their interactions have to be well understood. Amine-functionalized polystyrene and carboxyl-functionalized magnetic microspheres of ~6.0 ìm in diameter were used to immobilize heparin. The amount of heparin immobilized on polystyrene beads was 5.82 x 10-8 ± 0.36 x 10-8 M per 1.0 x 106 beads and for magnetic beads was 0.64 x 10-8 ± 0.01 x …

Intake, Digestibility, Insitu Disappearance And Ruminal Fermentation Of Bermuda Grass Hay By Lactating Beef Cows Offered Corn Or Hominy Feed As Supplements, Zibani Madzonga

Graduate Theses and Dissertations

Hominy feed, a co-product of dry corn milling, has been evaluated to a limited extent in feedlot and dairy rations, but has not been evaluated as a supplemental energy source for lactating beef cows. The objective of this study was to determine the effect of level of hominy feed supplementation on intake, digestibility, in situ DM disappearance, and ruminal fermentation characteristics of medium quality bermudagrass hay. Five ruminally cannulated lactating beef cows (BW = 596 kg, SE = 13.9) were used in an experiment with a 5 × 5 Latin square design. Treatments were low hominy (LH; 0.25% …

Three-Dimensional Scene Reconstruction Using Multiple Microsoft Kinects, Matt Miller

Graduate Theses and Dissertations

The Microsoft Kinect represents a leap forward in the form of cheap, consumer friendly, depth sensing cameras. Through the use of the depth information as well as the accompanying RGB camera image, it becomes possible to represent the scene, what the camera sees, as a three-dimensional geometric model. In this thesis, we explore how to obtain useful data from the Kinect, and how to use it for the creation of a three-dimensional geometric model of the scene. We develop and test multiple ways of improving the depth information received from the Kinect, in order to create smoother three-dimensional models. We …

Mitigating Insider Threat In Relational Database Systems, Qussai Yaseen

Graduate Theses and Dissertations

The dissertation concentrates on addressing the factors and capabilities that enable insiders to violate systems security. It focuses on modeling the accumulative knowledge that insiders get throughout legal accesses, and it concentrates on analyzing the dependencies and constraints among data items and represents them using graph-based methods. The dissertation proposes new types of Knowledge Graphs (KGs) to represent insiders' knowledgebases. Furthermore, it introduces the Neural Dependency and Inference Graph (NDIG) and Constraints and Dependencies Graph (CDG) to demonstrate the dependencies and constraints among data items. The dissertation discusses in detail how insiders use knowledgebases and dependencies and constraints to get …

Implementation Of Orthogonal Frequency Division Multiplexing With Fpga, Qi Hao Yang

Graduate Theses and Dissertations

In recent years, there have been dramatic shifts in cellular and telecommunication industries. As smartphones are dominating on the cellphone market, more and more people use these mobile devices to access internet either through third generation network or IEEE802.11 wireless local area network. Orthogonal frequency division multiplexing (OFDM) has been widely used in IEEE802.11 wireless local area network and fourth generation network. This paper will focus on the design and implementation of an Orthogonal Frequency Division Multiplexing system on field-programmable gate array (FPGA). The major components of an OFDM system include a modulator, an N-input inverse Fast Fourier Transform (IFFT), …

A Description Of Nonprofit Executive Leaders' Perceptions Of Human Resource Capacity Building Within Their Organizations, Synetra Danielle Gilmer

Graduate Theses and Dissertations

Researchers have predicted that within the next 5 to 15 years the nonprofit sector will undergo a dramatic loss in leadership due to baby boomers entering retirement, job transitions, and underdeveloped talent within nonprofit organizations. Effective leaders are critical in keeping these organizations running so that they can serve and provide much needed services, thus investing in their organizations is the key to keeping NPOs relevant in the future. Investing in training and development, intellectual capital, and succession planning are just a few of the human resource capacity building efforts that have been credited for helping to alleviate some of …

Becoming Pearls: Patterns Of Social Reading In Arabian Nights' Entertainments, Rachel Elizabeth Gould

Graduate Theses and Dissertations

As soon as the first English texts began to appear, Arabian Nights' Entertainments, as translated by Antoine Galland, captivated the imaginations of most of eighteenth century England, bringing the work instantly into demand. Although the Arabian Nights' Entertainments is generally recognized among scholars for its influence on other fictional tales and travel narratives and its shaping of the West's perception of the East, further study is needed in ascertaining the effect of the rhetorical device of repetition, which is so prevalent within the tales and which gives the collection both its unique character and its ability to engage readers …

Ultra-Low Power And Radiation Hardened Asynchronous Circuit Design, Liang Zhou

Graduate Theses and Dissertations

This dissertation proposes an ultra-low power design methodology called bit-wise MTNCL for bit-wise pipelined asynchronous circuits, which combines multi-threshold CMOS (MTCMOS) with bit-wise pipelined NULL Convention Logic (NCL) systems. It provides the leakage power advantages of an all high-Vt implementation with a reasonable speed penalty compared to the all low-Vt implementation, and has negligible area overhead. It was enhanced to handle indeterminate standby states. The original MTNCL concept was enhanced significantly by sleeping Registers and Completion Logic as well as Combinational circuits to reduce area, leakage power, and energy per operation.

This dissertation also develops an architecture that allows NCL …