Digital Commons Network^™

Using Stable Isotope Geochemistry To Determine Changing Paleohydrology And Diagenetic Alteration In The Late Cretaceous Kaiparowits Formation, Ut Usa, Daigo Yamamura

Graduate Theses and Dissertations

The Western Interior Basin of the North America preserves one of the best sedimentary and paleontological records of the Cretaceous in the world. The Upper Cretaceous Kaiparowits Formation is a rapidly deposited fluvial sequence and preserves one of the most complete terrestrial fossil record of the North America. Such a unique deposit provides an opportunity to investigate the interaction between the physical environment and ecology. In an effort to decipher such interaction, stable isotope composition of cements in sedimentary rocks, concretions and vertebrate fossils were analyzed.

Despite the difference in facies and sedimentary architecture, the isotope composition does not change …

Essays In Measuring, Controlling, And Coordinating Supply Chain Inventory And Transportation Operations, Payam Parsa

Graduate Theses and Dissertations

Supply chain collaboration programs, such as continuous replenishment program (CRP), is among the most popular supply chain management practices. CRP is an arrangement between two partners in a supply chain to share information on a regular basis for lowering logistics costs while maintaining or increasing service levels. CRP shifts the replenishment responsibility to the upstream partner to avoid the bullwhip effect across the supply chain. This dissertation aims to quantify, measure, and expand the benefits of CRP for the purpose of reducing logistics cost and improving customer service. The developed models in this dissertation are all applied in different case …

An Economic Analysis Of Residential Photovoltaic Systems With And Without Energy Storage, Rodney Moses Kizito

Graduate Theses and Dissertations

Residential photovoltaic (PV) systems serve as a source of electricity generation that is separate from the traditional utilities. Investor investment into residential PV systems provides several financial benefits such as federal tax credit incentives for installation, net metering credit from excess generated electricity added back to the grid, and savings in price per kilowatt-hour (kWh) from the PV system generation versus the increasing conventional utility price per kWh. As much benefit as stand-alone PV systems present, the incorporation of energy storage yields even greater benefits. Energy storage (ES) is capable of storing unused PV provided energy from daytime periods of …

Models And Methodologies To Address Emerging Needs In Network And Supply Chain Optimization, Forough Enayaty Ahangar

Graduate Theses and Dissertations

In this dissertation, we model three different security scenarios and propose solution methodologies to address each problem.

Chapter 2 presents a large-scale optimization approach for solving a dynamic bi-level network interdiction problem (NIP) in which interdiction activities must be scheduled in order to minimize the cumulative maximum flow over a finite time horizon. A logic-based decomposition (LBD) approach is proposed that utilizes constraint programming to exploit the scheduling nature of this dynamic NIP. Chapter 3 considers a set of centers to which content (e.g., data or smuggled items), are assigned to ensure availability. An interdictor (e.g., border security officials) attempts …

Characterization Of A Tuberous Sclerosis Complex 2 Variant And Its Interaction Involving The Ras-Related Protein Rheb, Nosaiba Shokr

Graduate Theses and Dissertations

Structure-function relationships of any complex underlie the molecular details of the biological interactions. Rheb, Ras Homology Enriched in Brain, is a Ras-related protein, and it is genetically identified as a molecular switch. Rheb is regulated by cycling between the biologically active GTP and inactive GDP-bound forms. This regulation is partially controlled by an interaction with Tuberous Sclerosis Complex2 (TSC2), a GTPase activating protein (GAP). Upon interaction, TSC2 stimulates Rheb GTP hydrolysis and diminishes the mammalian target of rapamycin (mTOR) pathway. The mTOR pathway is involved in proteins synthesis, cell cycle, and signaling. Mutation in TSC2 causes abnormal activation of Rheb …

A Linear-Linear Growth Model With Individual Change Point And Its Application To Ecls-K Data, Ping Zhang

Graduate Theses and Dissertations

The latent growth curve model with piecewise functions is a useful analytics tool to investigate the growth trajectory consisted of distinct phases of development in observed variables. An interesting feature of the growth trajectory is the time point that the trajectory changes from one phase to another one. In this thesis, we propose a simple computational pipeline to locate the change point under the linear-linear piecewise model and apply it to the longitudinal study of reading and math ability in early childhood (from kindergarten to eighth grade). In the first step, we conduct the hypothesis testing to filter out the …

Creating Sustainable Supply Chains: Influencing Sustainable Practices In The Supply Chain, Saif Mir

Graduate Theses and Dissertations

Organizations worldwide are reporting their commitment to create sustainable supply chains. Ultimately, supply chain professionals are the drivers of change within their respective organizations, so this dissertation examines the role of communication as a tool to persuade supply chain professionals to create sustainable supply chains. The three studies within this dissertation employ different methodologies to examine the role of communication in the development and implementation of sustainability initiatives. The first study, a grounded theory investigation, highlights the network, communication, and structural factors that provide a strong business case for the development of sustainability initiatives. A strong business case influences the …

Simulation Modeling Approach For Evaluating A Solution Designed To Alleviate The Congestion Of Passenger Flow At The Composure Area Of Security Checkpoints, Maria Luisa Janer Rubio

Graduate Theses and Dissertations

In a previous study, we found that replacing the exit roller of a security checkpoint lane for a continuously circulating conveyor could potentially increase the throughput of passengers by over 28% while maintaining the TSA security-waiting time limit (Janer and Rossetti 2016). This study intends to expand this previous effort by investigating the impact of this circulating conveyor on the secondary screening related processes. Leone and Liu (2011) found that imposing a limit on the x-ray screening time, and diverting any item exceeding this limit to secondary screening, could decrease the waiting time by 43%. Our objective is to verify …

A Laboratory-Scale Study On The Production Of High-Value Products From Broiler Litter Involving Solid-State Anaerobic Digestion And Mushroom Cultivation, Joe Barrett Carter Iii

Graduate Theses and Dissertations

There is a need to investigate alternate uses and treatments of broiler litter that lessen environmental impacts and decrease costs associated with its disposal. Anaerobic digestion is a biological process in which organic material is converted to a renewable fuel source. However, the substrate for anaerobic digestion often requires some form or pretreatment. Certain types of fungus have been investigated as a pretreatment for anaerobic digestion, one of which is Pleurotis ostreatus or the oyster mushroom, which also produces an edible fruiting body. Thus, this study was performed to investigate the use of broiler litter for oyster mushroom cultivation and …

Π-Operators In Clifford Analysis And Its Applications, Wanqing Cheng

Graduate Theses and Dissertations

In this dissertation, we studies Π-operators in different spaces using Clifford algebras. This approach generalizes the Π-operator theory on the complex plane to higher dimensional spaces. It also allows us to investigate the existence of the solutions to Beltrami equations in different spaces.

Motivated by the form of the Π-operator on the complex plane, we first construct a Π-operator on a general Clifford-Hilbert module. It is shown that this operator is an L^2 isometry. Further, this can also be used for solving certain Beltrami equations when the Hilbert space is the L^2 space of a measure space. This idea is …

Decision Support System For Container Port Selection Using Multiple-Objective Decision Analysis, Rivelino De Icaza

Graduate Theses and Dissertations

Ports are essential for maritime transportation and global supply chains since they are nodes that connect the sea- and land-based modes of transportation. With containerization and supply chains stimulating global trade, ports are challenged to adjust to changes in the market to create value to their customers. Therefore, this dissertation research focuses on the container port selection decision analysis to provide information to help shipping lines select the best port for their shipping networks. Since the problem is complex, dynamic, and involves multiple and conflicting criteria, the research proposes to use the multi-objective decision analysis with Value-Focused Thinking approach. The …

Does Industry-Level Information Affect Auditors’ Assessment Of Client-Level Risk?, David Rosser

Graduate Theses and Dissertations

This study investigates auditors’ consideration of industry-level information in their assessment of client-level risk. Auditing standards suggest that industry-level information is likely to be important in the assessment of client-level risk, but the standards provide few specifics about how auditors should use industry-level information in the risk assessment process. I argue that industry norms serve as a benchmark for evaluating the risk of the client and that deviations from industry norms could indicate increased audit risk. I create measures that capture the extent to which clients deviate from industry norms using proxies for client-level risk factors. In my primary tests, …

Near Surface Geophysics For Lithostratigraphic Interpretation At Pedro, Benton County, Arkansas, Matthew David Ruggeri

Graduate Theses and Dissertations

The roadcut on highway 412 near Pedro, Benton County, Arkansas (MArkUP site L15), has been of geological interest since its excavation in the 1980s. The roadcut is located within the Springfield Plateau and displays formations of Lower Mississippian age. The roadcut contains three mound-like features believed to be olistoliths. This thesis research work adds geophysical evidence to the geological exposure at the site. The purpose of this research is to answer the question of whether near surface seismic methods can be used to extend information at the Pedro outcrop below the ground surface. Specifically, can the top of the Middle …

The Functionalization Of N-Cyclobutylanilines Under Photoredox Catalysis, Jiang Wang

Graduate Theses and Dissertations

While transition metal catalyzed cross coupling reactions have become one of the most useful strategies in constructing carbon-carbon and carbon-heteroatom bond formations, major disadvantages such as high reaction temperature, expansive metal catalysts input and limited reaction substrates scope have significantly downshifted the applications of those two electron involved transformations. Comparably, the studies on the redox coupling reactions are less investigated. Derived from single electron transfer process, the redox coupling reactions can be used to construct otherwise challenging chemical bonds efficiently, such as Csp3-Csp3 bond. Recently, visible light mediated photoredox catalysis has merged as a highly prominent tool in the development …

The Bicycle, The Unsuitable Substitute:A Feasibility Study Based In Fayetteville, Ar Using A Bicycle As A Year-Round Replacement For An Automobile, Jamey Voorhees

Graduate Theses and Dissertations

Can a bicycle can be used in place of an automobile for everyday transportation and commuting needs? Fayetteville, Arkansas is a bicycle friendly and they plan continue to expand the current trail system improve other components in the future. Alternative transportation forms like the bicycle are important but only if bikes are integrated into traffic which needs to be done in some way that all involved understand their place in the system. By actively participating in this system I have attempted to show that a bicycle is just not feasible as a form of daily transportation in a city like …

Characterization Of Nanoparticles Using Solid State Nanopores, Santoshi Nandivada

Graduate Theses and Dissertations

Solid state nanopores are widely used in detection of highly charged biomolecules like DNA and proteins. In this study, we use a solid state nanopore based device to characterize spherical nanoparticles to estimate their size and electrical charge using the principle of resistive pulse technique. The principle of resistive pulse technique is the method of counting and sizing particles suspended in a fluid medium, which are electrophoretically driven through a channel and produce current blockage signals due to giving rise to a change in its initial current. This change in current is denoted as a current blockage or as a …

Understanding Discourse Transition, Taylor Weeks

Graduate Theses and Dissertations

This work is intended to explore and analyze the process of transition from one discourse to another different discourse.

Statistical Movement Classification Based On Hilbert-Huang Transform, Shanqi Sun

Graduate Theses and Dissertations

The goal of this project is to introduce an automatic movement classification technique of

finger movement signals using Hilbert-Huang Transform (HHT). Due to the nonlinear and

nonstationary processing behavior, movement signals are analyzed with the Hilbert-Huang

Transform (HHT). The slope of auto-correlation function and mean of frequency from first

three Intrinsic Mode Functions (IMFs) was used as feature parameters for each category.

Finally, performing support vector machine (SVM) for pattern classification completes clas-

sifying types of finger movement. According to the records of 669 trial samples of two types

of finger movement signals (thumb and pinky), average accuracy is 93.28%. …

An Upper Limit On The Tightening Of Galactic Spiral Arm Pitch Angle In Cosmic Time, Douglas William Shields

Graduate Theses and Dissertations

We present Spirality, a novel method of measuring pitch angle by fitting galaxy images to spiral templates of known pitch. Using this algorithm in concert with 2-dimensional Fast Fourier Transform (2DFFT), we determined that the pitch angle of the redshift 2.011 galaxy GZ5001 (J2000 RA 189.14811 degrees, Dec 62.24002 degrees) is approximately (16.2 +/- 2.6) degrees. The redshift 2.3219 galaxy GS21 (J2000 RA 53.14863 degrees, Dec -27.95469 degrees), which is believed to be the most distant galaxy with visible spiral structure yet measured, has a pitch of approximately (-10.6 +/- 1.6) degrees. Using a large sample of galaxies from the …

A Numerical Study Of The Interaction Between One Dimensional Carbyne Chain And Single Stranded Dna, Zeina Salman

Graduate Theses and Dissertations

resolution at the single nucleotide level when developing DNA sequencers. The purpose of this research was to numerically study the electrical properties associated with the interaction between 1D carbon chain, known as carbyne, and ssDNA. First, the electrical properties of the carbyne chain were calculated. Second, the electrical properties of the carbyne chain were calculated in the presence of different ssDNA bases. Analyzing the differences between the two cases led to determining the effects of these different bases on the electrical properties. The numerical simulation approach conducted in this research was based on the first-principle simulation. The first-principle simulation was …

Understanding N-Nitrosodimethylamine Formation In Water: Chloramine Chemistry, Kinetics, And A Proposed Reaction Pathway, Huong Thu Pham

Graduate Theses and Dissertations

The formation of N-nitrosodimethylamine (NDMA) in drinking water systems is a concern because of its potential carcinogenicity and occurrence at toxicologically relevant levels. The postulated mechanism for NDMA formation involves a substitution between dichloramine and amine-based precursors to form an unsymmetrical dimethylhydrazine (UDMH), which is then oxidized by ground-state molecular oxygen to form NDMA. However, this latter reaction is spin forbidden, thus likely occurs at a slow rate. It is hypothesized that the reaction between monochloramine and hydroxylamine (a nitrification product) may form an intermediate, which is involved in the NDMA formation pathway. This intermediate may also be generated from …

Development Of A Multiband Remote Sensing System For Determination Of Unsaturated Soil Properties, Cyrus D. Garner

Graduate Theses and Dissertations

A multiband system including active microwave sensing and visible-near infrared reflectance spectroscopy was developed to measure unsaturated soil properties in both field and laboratory environments. Remote measurements of soil volumetric water content (θv), soil water matric potential (ψ), and soil index properties (liquid limit [LL], plastic limit [PL], and clay fraction [CF]) were conducted. Field-based measurement of θv was conducted using a ground-based radar system and field measurements within 10 percentage points of measurements acquired with traditional sampling techniques were obtained. Laboratory-based, visible and near infrared spectroscopy was found to be capable of obtaining empirical, soil specific regression functions (partial …

Rock Art Management And Landscape Change: Mixed Field Assessment Techniques For Cultural Stone Decay, Kaelin M. Groom

Graduate Theses and Dissertations

As tourism continues to grow as one of the world’s most ubiquitous markets, the development and promotion of non-invasive techniques for cultural stone decay analysis and landscape change are vital to establishing conditional base-lines to best aid cultural heritage management (CRM) efficacy. Using rock art as a medium, this dissertation presents three independent case studies employing the Rock Art Stability Index (RASI) and repeat photography to explore the merits of mixed rapid field assessment techniques in relation to CRM and heritage tourism. While rock art is only one example of irreplaceable world heritage resources, examining how they decay and what …

Numerical Simulation Of Metallic Uranium Sintering, Bruce Berry

Graduate Theses and Dissertations

Conventional ceramic oxide nuclear fuels are limited in their thermal and life-cycle properties. The desire to operate at higher burnups as is required by current utility economics has proven a formidable challenge for oxide fuel designs. Metallic formulations have superior thermal performance but are plagued by volumetric swelling due to fission gas buildup. In this study, we consider a number of specific microstructure configurations that have been experimentally shown to exhibit considerable resistance to porosity loss. Specifically, a void sizing that is bimodally distributed was shown to resist early pore loss and could provide collection sites for fission gas buildup. …

A Comparison Of Force And Pressure Coefficients On Dome, Cube And Prism Shaped Buildings Due To Straight And Tornadic Wind Using Three Dimensional Computational Fluids Dynamics, Majdi A. A. Yousef

Graduate Theses and Dissertations

Tornadoes induce very different wind forces than a straight-line (SL) wind. A suitably designed building for a SL wind may fail when exposed to a tornado-wind of the same wind speed. It is necessary to design buildings that are more resistant to tornadoes. Most studies have been conducted to investigate tornado forces on cubic, gable-roof and cylinder buildings. However, little attention has been paid to investigate tornado force on dome buildings; hence, further research is conducted in this study. The forces on a dome, cube and prisms were analyzed and compared using Computational Fluid Dynamics (CFD) for tornadic and SL …

Strategies Of Reading As A Second Language Instruction Across Curriculum In Secondary Grades, Anisa A. Ben Idris

Graduate Theses and Dissertations

This study explored what themes of best practices teachers report using in real classrooms to teach reading skills to ESL students across curricula. It examined teachers’ applications of the following five themes in their instruction as a regular routine described as best practices in the literature for teaching diverse students: (1) providing comprehensible input, (2) teaching learning strategies of metacognition to bridge the gap between school literacy practices and home literacy practices (3) lowering the affective filter, (4) implementing formative assessment, and (5) cooperating between teachers and ESL facilitators. The study involved teachers from two high schools in one school …

Influence Of Histidine Residues, Ph And Charge Interactions On Membrane-Spanning Peptides, Ashley N. Henderson

Graduate Theses and Dissertations

Designed transmembrane peptides were employed for investigations of histidine residues within the hydrophobic environment of the lipid bilayer by means of oriented solid-state deuterium NMR spectroscopy. Using the model peptide GWALP23 sequence (GGALW(LA)6LWLAGA) as a host framework, the effects of single and double histidine mutations were explored. Replacement of leucine residue 12 to polar neutral histidine had little influence on the peptide average orientation, however under strongly acidic pH conditions in DOPC bilayers, the histidine becomes positively charged (pKa 2.5) and the GWALP23-H12 peptide exits the membrane and adopts a surface-bound orientation. Conversely, mutation of leucine 14 to neutral histidine …

Temporal Evaluation Of Corn Respiration Rates Using Pressure Sensors, Gagandeep Singh Ubhi

Graduate Theses and Dissertations

High respiration rate of a grain indicates faster degradation of its dry matter. Proper grain management requires chronological and precise measurements of carbon dioxide evolved from grain respiration during the postharvest storage duration. Therefore the main goal of this research was to develop a new technique that evaluates temporal corn respiration rate using pressure sensors. It was based on measuring pressure drop associated with the grain respiration in a closed container and using it to calculate the grain respiration rates.

Dry corn (Zea Mays L.) was procured from a local farmer and stored at 4ºC. Corn rewetting technique was applied …

Influence Of Stream Permanence, Predation, And Invasive Species On Crayfish In The Ozark Highlands With An Emphasis On Species Of Greatest Conservation Need (Orconectes Marchandi, Orconectes Eupunctus And Cambarus Hubbsi), Allyson Noelle Yarra

Graduate Theses and Dissertations

Due to the ecological importance of crayfish and the increasing vulnerability of freshwater systems due to habitat loss, invasive species, and hydrologic alteration, understanding crayfish-environment relationships is crucial in the context of aquatic species conservation. I sought to examine the influence of hydrologic variation among intermittent and permanent streams on crayfish occupancy, abundance, predation risk, and potential vulnerability to invasive species effects. I conducted crayfish and environmental data sampling during two consecutive summers across 20 Ozark streams of differing permanence levels (10 intermittent, 10 permanent). In these same streams, I conducted fish and scat surveys over the course of four …

Exploiting Semantic Distance In Linked Open Data For Recommendation, Sultan Dawood Alfarhood

Graduate Theses and Dissertations

The use of Linked Open Data (LOD) has been explored in recommender systems in different ways, primarily through its graphical representation. The graph structure of LOD is utilized to measure inter-resource relatedness via their semantic distance in the graph. The intuition behind this approach is that the more connected resources are to each other, the more related they are. One drawback of this approach is that it treats all inter-resource connections identically rather than prioritizing links that may be more important in semantic relatedness calculations. Another drawback of current approaches is that they only consider resources that are connected directly …