Digital Commons Network^™

Natural Air Drying And Storage Of Soybean Seed And Implications On Germination Rates, Vigor, And Oil Quality, Zachary Young

Graduate Theses and Dissertations

Recently introduced technology-comprising cables used for monitoring grain moisture content (MC) and temperature throughout the entire grain mass during drying offers a means to utilize low-temperature natural air-drying for soybean seed. From an electronic monitor and fan control standpoint, the new technology appears to be very promising for managing drying and storage conditions for soybean seed. The objectives for this study were to simulate conditions typically encountered in on-farm, in-bin drying systems and investigate impact of seed cultivar, temperature, moisture content and duration of storage on seed germination rates and vigor (electrical conductivity). In addition this research addresses the problem …

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 …

A Low Temperature Co-Fired Ceramic (Ltcc) Interposer Based Three-Dimensional Stacked Wire Bondless Power Module, Atanu Dutta

Graduate Theses and Dissertations

The objective of this dissertation research is to develop a low temperature co-fired ceramic (LTCC) interposer-based module-level 3-D wire bondless stacked power module. As part of the dissertation work, the 3-D wire bondless stack is designed, simulated, fabricated and characterized. The 3-D wire bondless stack is realized with two stand-alone power modules in a half-bridge configuration. Each stand-alone power module consists of two 1200 V 25 A silicon insulated-gate bipolar transistor (IGBT) devices in parallel and two 1200 V 20 A Schottky barrier diodes (SBD) in an antiparallel configuration. A novel interconnection scheme with conductive clamps and a spring loaded …

Linear Dna-Linked Nanoparticle Building Blocks (Nblocks) For Modular Self-Assembly Of Nanostructures, Jakob Thomas Hockman

Graduate Theses and Dissertations

Controlling the shapes and sizes of nanomaterials often enables controlling their properties for certain applications. The most promising methods for controlling the shapes and sizes of nanostructures use base-pairing between complementary DNA strands to self-assemble nanostructures from DNA and nanoparticles. DNA Brick-based self-assembly is a particularly useful method for creating DNA nanostructures. It offers a large amount of control over the final shapes and sizes because it uses building blocks that are anisotropic and have predictable geometry. However, this control has not been extended to the self-assembly of nanostructures from nanoparticles. Applying DNA Brick based self-assembly to the self-assembly of …

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 …

The Influence Of Visual Storytelling On The Occupational Aspirations Of Non-Agricultural Undergraduate Students, Hanan Marie Southard

Graduate Theses and Dissertations

The agricultural industry has been experiencing a shortage in qualified college graduates to fill its numerous open positions in recent years. The purpose of this study was to investigate the influence of visual storytelling on the occupational aspirations of non-agricultural undergraduate students. Social media channels, virtual storytelling and the higher education classroom provide a unique opportunity to convey information about and recruit students into the agricultural career field. The diffusion of innovation model provides the framework for the introduction of agricultural jobs in a non-agricultural business classroom while the social cognitive theory provides the understanding of the importance of self-efficacy …

Personalized Decision Modeling For Intervention And Prevention Of Cancers, Fan Wang

Graduate Theses and Dissertations

Personalized medicine has been utilized in all stages of cancer care in recent years, including the prevention, diagnosis, treatment and follow-up. Since prevention and early intervention are particularly crucial in reducing cancer mortalities, personalizing the corresponding strategies and decisions so as to provide the most appropriate or optimal medical services for different patients can greatly improve the current cancer control practices. This dissertation research performs an in-depth exploration of personalized decision modeling of cancer intervention and prevention problems. We investigate the patient-specific screening and vaccination strategies for breast cancer and the cancers related to human papillomavirus (HPV), representatively. Three popular …

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 …

The Structural And Functional Properties Of A Double Mutant Of Human Acidic Fibroblast Growth Factor (Hfgf-1), Arwa Mohammed Alghanmi

Graduate Theses and Dissertations

Human acidic Fibroblast Growth Factor 1 (FGF-1), a member of the FGF superfamily, is a potent mitogen and heparin-binding protein involved in a broad spectrum of biological processes, including angiogenesis, cell proliferation, and wound healing. Design of hFGF-1 with an increased thermal stability and an enhanced cell proliferation activity is highly desired for wound healing applications. Herein, we have designed the variant of FGF-1 by substituting two important amino residues in the heparin-binding pocket. The variant was overexpressed in Escherichia coli and was successfully purified to homogeneity using an affinity chromatographic procedure. Far-UV circular dichroism spectroscopic analysis showed that the …

Essays On Common-Pool Resources: Evaluation Of Water Management And Conservation Programs, Kuatbay K. Bektemirov

Graduate Theses and Dissertations

This dissertation is comprised of three essays that examine water management and conservation programs through the context of sustainable development. These essays are distinct case studies of national, state and local policies. Their common approach is that they all use common-pool resources theory to generate specific recommendations for policymaking and water management.

The first essay explores opportunities for developing policy measures to prevent the collapse of the vital irrigation infrastructure in the Aral Sea region. The paper looks at the economic efficiency of various policy options, impacts on the country’s agricultural sector, and the regulations needed to make the cost-sharing …

Evaluating The Impact Of An All-Vegetable Protein Supplement Containing Fat Emulsifiers And Probiotics On Broiler Performance, Jordan Weil

Graduate Theses and Dissertations

Currently, several niche markets, such as organic and “all natural”, are marketed within the poultry industry. However, little research has been undertaken to determine the cost-effectiveness of poultry diets used to produce chicken within these markets. Specifically, the economics and resulting profits associated with raising chicken with antibiotic-free, all-vegetable (AV) diets are not evaluated. As national chain restaurants such as Chick-fil-A and Panera Bread begin to mandate poultry suppliers raise chicken without antibiotics and use AV diets, it becomes increasingly important to evaluate the economics for integrators. Given the rapidly changing feeding strategies necessary to respond to consumers’ and wholesalers’ …

Evaluating Methods For Quantifying Evapotranspiration In Arkansas Rice, Colby Reavis

Graduate Theses and Dissertations

The goal of this study was to evaluate different methods for quantifying evapotranspiration (ET) in commercial rice fields using different irrigation regimes. The rice fields were located in south central Arkansas. The different irrigation regimes were alternate wetting and drying (AWD) and continuous flooding (CF). Alternate wetting and drying and conventional flooding estimates of ET were 602 mm and 570 mm, respectively, based on field observations using eddy covariance. Models used to estimate ET estimated values between 498 and 653 mm for the 2015 growing season. The Penman Monteith actual evapotranspiration model (PM AET) performed best when compared to the …

Membrane Surface Engineering For Biochemical Applications, Anh T. Vu

Graduate Theses and Dissertations

Synthetic membranes have been frequently used for many fields, such as, the food and beverage, biopharmaceutical, and biofuel industries. In the beer industry, microfiltration frequently suffers from fouling due to the interaction between different species. It is shown that polyphenols can form cross-links with protein molecules, forming insoluble aggregates. However, by adding an optimal amount of polysaccharides these aggregates can be disrupted thus reducing fouling by the aggregates. Confocal laser scanning microscopy (CLSM) is a powerful technique to locate the foulants inside the wet membrane in order to understand more about the behavior of fouling in microfiltration.

Membrane surface modification …

Si-Based Germanium Tin Semiconductor Lasers For Optoelectronic Applications, Sattar H. Sweilim Al-Kabi

Graduate Theses and Dissertations

Silicon-based materials and optoelectronic devices are of great interest as they could be monolithically integrated in the current Si complementary metal-oxide-semiconductor (CMOS) processes. The integration of optoelectronic components on the CMOS platform has long been limited due to the unavailability of Si-based laser sources. A Si-based monolithic laser is highly desirable for full integration of Si photonics chip. In this work, Si-based germanium-tin (GeSn) lasers have been demonstrated as direct bandgap group-IV laser sources. This opens a completely new avenue from the traditional III-V integration approach. In this work, the material and optical properties of GeSn alloys were comprehensively studied. …

Removal Of Endocrine Disrupting Compounds Using Membrane Bioreactor, Mohanad Ali Abdulsahib Kamaz

Graduate Theses and Dissertations

The presence of endocrine disrupting compounds (EDCs) and pharmaceutically active compounds (PhAC) such as pesticides, personal care products, antibiotics and pharmaceutical compounds, in sewage, industrial, and domestic waters has extensively become the major concern for health and environmental organizations. These compounds have the ability to interact with mammalian endocrine system and disrupting their functions. The traditional activated sludge processes are designed to degrade solids, organic carbon and nitrogen loading. Although several treatment steps in a wastewater treatment plant can contribute to partial removal of EDCs, effective removal has been a challenge due to their resistant chemical and biological degradation and …

Modeling Ozark Caves With Structure-From-Motion Photogrammetry: An Assessment Of Stand-Alone Photogrammetry For 3-Dimensional Cave Survey, Joseph H. Jordan

Graduate Theses and Dissertations

Nearly all aspects of karst science and management begin with a map. Yet despite this fact, cave survey is largely conducted in the same archaic way that is has been for years - with a compass, tape measure, and a sketchpad. Traditional cave survey can establish accurate survey lines quickly. However, passage walls, ledges, profiles, and cross-sections are time intensive and ultimately rely on the sketcher’s experience at interpretively hand drawing these features between survey stations.

This project endeavors to experiment with photogrammetry as a method of improving on traditional cave survey, while also avoiding some of the major pitfalls …

Evaluating Thermal Comfort Of Broiler Chickens During Transportation Using Heat Index And Simulated Electronic Chickens, Kaushik Luthra

Graduate Theses and Dissertations

Broilers experience high physiological stress during pre-slaughter transport, especially under extremes of thermal environment. Characterization of thermal environment on the trailer is crucial to identify stress-prone regions during transportation. At the same time, Broilers experience high physiological stress during pre-slaughter transport, especially under extremes of thermal environment. Characterization of thermal environment on the trailer is crucial to identify stress-prone regions during transportation. At the same time, quantification of heat loss of the broilers loaded on trailers is important in understanding the well-being of the broilers. We have developed four electronic chickens (E-chickens) to simulate the sensible heat loss of live …

Factors Contributing To The Success Of First-Generation College Students At A Research University, Mary Margaret Hui

Graduate Theses and Dissertations

First-generation college students are students whose parents do not have a college degree, and they face numerous barriers in college. Yet, several first-generation college students (FGCS) are successful and are on-track to graduate with a bachelor’s degree in four years. Their success is important because education is associated with increased income, quality of life, and social mobility, making educational attainment even more significant in Arkansas, which has both low educational attainment and high poverty. Little is known about what can be done to close the achievement gap. It is important to analyze what helped FGCS succeed so that higher education …

Application Of X-Ray Imaging As A Technique For Fissure Detection In Rough Rice Kernels, Zephania R. Odek

Graduate Theses and Dissertations

Fissured rice kernels break during milling, leading to head rice yield (HRY) reductions. Conventional fissure detection instruments cannot be used to observe fissures in rough rice kernels, the form in which rice in normally dried and stored. X-rays can penetrate hulls allowing visualization of the internal structure of a rough rice kernel. This study evaluated the capability of X-ray imaging to adequately detect fissures in rough rice and established a correlation between HRY and the fissured kernel percentage (FKP) in a rough rice sample. Fifteen long-grain rice cultivars, harvested in Arkansas in 2015 and 2016 were dried using heated air …

Uas As An Inventory Tool: A Photogrammetric Approach To Volume Estimation, Richard Kramer Rhodes

Graduate Theses and Dissertations

Unmanned aircraft systems (UAS), also referred to as unmanned aerial vehicles (UAV) or remotely piloted vehicles (RPV), are associated with unmanned aircraft either controlled by a pilot on the ground or pre-programmed with specific flight paths. Small UASs have seen a massive increase in public interest in recent years as hobbyist platforms; they are, however, a potentially powerful tool in remote sensing and geospatial applications. Due to the increased availability of low-cost UAS, this technology could soon revolutionize many industries, including those that require volumetric estimation. Traditionally volumetric inventories have been performed with tape measurements, and in some instances where …

Enforcing Database Security On Cloud Using A Trusted Third Party Based Model, Victor Fuentes Tello

Graduate Theses and Dissertations

Cloud computing offers a considerable number of advantages to clients and organizations that use several capabilities to store sensitive data, interact with applications, or use technology infrastructure to perform daily activities. The development of new models in cloud computing brings with it a series of elements that must be considered by companies, particularly when the sensitive data needs to be protected. There are some concerns related to security that need to be taken into consideration when a service provider manage and store the data in a location outside the company. In this research, a model that uses a trusted third …

Effects Of Chemical And Enzymatic Modifications On Starch And Naringenin Complexation, Ana Isabel Gonzalez Conde

Graduate Theses and Dissertations

Naringenin is a flavanone naturally present in grapefruit and tomato skin, which has been demonstrated to have health benefits. However, because of the low water solubility and bioavailability, naringenin applications are limited. Starch inclusion complexes have been shown to improve the solubility and bioavailability of poorly water soluble bioactive compounds. The present study aimed to prepare and characterize complexes of naringenin with starches, including potato starch and high amylose corn starch (Hylon VII), which were chemically (acetylation or hydroxypropylation) and enzymatically modified (debranched or debrahced/β-amylase treated). Soluble and insoluble complexes were recovered, and their physicochemical properties were characterized. The treatments …

Experiment-Based Quantitative Modeling For The Antibacterial Activity Of Silver Nanoparticles, Mohammad Aminul Haque

Graduate Theses and Dissertations

Silver (Ag) has been well known for its antimicrobial activity for a long time. Recent research showed the potential of Ag nanoparticles as emerging antimicrobial agents. However, little quantitative analysis has been performed so far to decipher the mechanism of interaction between nanoparticles and bacteria. Here, a detailed analysis based on kinetic growth assay and colony forming unit assay has been carried out to study the antimicrobial effect of Ag nanoparticles against Escherichia coli (E. coli) bacteria. It was observed that the presence of Ag nanoparticles increased the lag time of bacterial growth while not affecting the maximum growth rate …

Interactive Effects Of Flow Regime, Climate Change, And Angler Harvest On Smallmouth Bass At The Southern Range Extent, Christopher Middaugh

Graduate Theses and Dissertations

The Ozark-Ouachita Interior Highlands of Arkansas, Oklahoma, and Missouri are the southern extent of native Smallmouth Bass Micropterus dolomieu range. Smallmouth Bass are an important species economically and ecologically, but it is unknown how climate change may affect them in this region and in particular how Smallmouth Bass may be affected differently across streams from various flow regimes. Here I present three projects investigating how climate change, flow regime, and angler harvest may interact to affect Smallmouth Bass over the coming century. I first modeled present and future water temperatures and calculated growth rate potential for Smallmouth Bass from streams …

Instrumental Aspects Of Oxygen Sensing: Quantitation And Recalibration Of A Biofouled Oxygen Sensor, Marlena Patrick

Graduate Theses and Dissertations

In vivo oxygen sensing is a critical area of research for medical applications, such as ischemic stroke, but this important topic is not fully understood or resolved. In addition, the best method for calibration of in vivo sensors is as yet undetermined. For all implantable devices, biofouling, the adsorption of biological material to the device surface, is another significant problem with no clear or well-defined solution. One method employed is to apply a protective polymer membrane to the sensor surface in order to minimize the adsorption of biological material. The work described here investigates two polymers applied to a gold …

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 …

Assessing Patient Perceptions Of Self-Care: Examining Chronic Disease In An Underserved Rural Area, Somer Leigh Overshon

Graduate Theses and Dissertations

The Affordable Care Act of 2010 mandated healthcare reform in the United States by requiring insurance coverage for more Americans. Further, the law deemed healthcare providers, communities and individuals throughout the nation were responsible for fighting chronic disease and escalating healthcare costs. Preventive care and self-care have been cited as low-cost options for initiating change in the American population by helping individuals have access, information and resources to make better healthcare choices and manage their chronic diseases. The purpose of this ethnographic study was to identify the perceptions of self-care from patients living with chronic disease in an underserved, rural …