Engineering Commons^™

Temperature Sensitivity Of Foamed Warm Mix Asphalt, Ryan Michael Hagedorn

Civil Engineering Undergraduate Honors Theses

Foamed warm mix asphalt (WMA) is a technology that is beginning to be utilized across the United States. Often, producers are placing foamed WMA at decreased temperatures without fully understanding the properties of this relatively new product. By studying the volumetric properties of laboratory produced foamed WMA, this study sought to better understand the temperature sensitivity of foamed WMA and the potential factors that contribute to this sensitivity. Two mix designs containing primarily limestone aggregate were tested using differing binder grades. It was determined that binder grade, binder source and potentially the inclusion of recycled asphalt pavement all influence how …

A Comparison And Evaluation Of Different Dynamic Characterization Approaches For Bridges, Juan Javier Torres Torres Goitia

Graduate Theses and Dissertations

The objective of this thesis was to compare different dynamic characterization approaches for full scale bridge structures to devise a rapid and reliable Structural Health Monitoring (SHM) program in the aftermath of a natural or manmade hazard. Present methods for structural condition evaluation of bridge structures rely heavily on on-site visual inspections of each structure by specially trained engineers and technicians. It has been proved in the literature that this current method is subjective, time consuming and manpower intensive, all of which are not suited for the critical conditions following a hazard event. This study focused on comparing three different …

Comparing Ferrous Chloride And Ferrous Sulfate As Secondary Coagulants At The Beaver Water District Drinking Water Treatment Plant, Jenny Doyle

Graduate Theses and Dissertations

In November 2012, the Beaver Water District (BWD) switched primary oxidants from free chlorine to chlorine dioxide (ClO2) to curb formation of trihalomethanes, a regulated group of organic disinfection byproducts (DBPs). Because ClO2 is reduced to chlorite (ClO2-), a regulated inorganic DBP, BWD incorporated ferrous salt into their coagulation regime to quench chlorite to chloride. In this study, two ferrous salts - ferrous chloride (FC) and ferrous sulfate (FS) - were compared as secondary coagulants in combination with alum, the primary coagulant. Ferrous salts were dosed stoichiometrically to reduce chlorite and alum was dosed at percentages (0-100%) relative to a …

Cost-Benefit Analyses For Load Resistance Factor Design (Lrfd) Of Drilled Shafts In Arkansas, Sarah Michelle Bey

Graduate Theses and Dissertations

To achieve more cost efficient transportation infrastructure within the state of Arkansas, a series of cost-benefit analyses were performed. The analyses, specifically developed for load resistance factor design (LRFD) designed drilled shaft foundations, were designed to compare the fiscal impacts of the drilling and sampling, in-field and laboratory testing, full-scale load testing, and concrete mixing techniques utilized by the University of Arkansas (UofA), the Arkansas Highway and Transportation Department (AHTD), and the Missouri Department of Transportation (MODOT). The methodologies were compared at three test site locations within the state of Arkansas: Siloam Springs, AR, Turrell, AR, and Monticello, AR. These …

Global Dynamic Characterization And Load Rating Of Bridge Structures Utilizing Economical Dynamic Excitation Devices, Eric Fernstrom

Graduate Theses and Dissertations

Experimental modal analysis (EMA) of bridges and other civil structures can be used to acquire quantitative data describing their condition, and enhance opportunities for structural health monitoring and related fields. The use of EMA on civil structures has been limited by the high cost of the excitation devices that are required for the best data quality. The objective of the research reported herein is to evaluate a low-cost excitation system for multiple-input, multiple-output (MIMO) EMA, enabling the production of accurate estimates of the global behavior of in-service bridges.

The prototype excitation system is composed of consumer entertainment devices, namely tactile …

Rapid Condition Assessment Of Bridges By Falling Weight Deflectometer, Jeremy David Rawn

Graduate Theses and Dissertations

The objective of this thesis is to investigate the feasibility of using a Falling Weight Deflectometer (FWD) as an impact source to rapidly assess the condition of an in service bridge through the evaluation of its modal properties. Tests were conducted on two bridges, a Parker Pony Truss and a modern concrete deck on rolled steel beam bridge. Two full tests were performed on these structures with a hand held impact hammer and a falling weight deflectometer as sources for excitation. The advantage of using a FWD is that many transportation agencies already use these machines for pavement testing and …

Phase Transformation In Monolayer Molybdenum Disulphide With And Without Defects Under Tension Predicted By Atomistic Simulations, Khanh Quoc Dang

Graduate Theses and Dissertations

In addition to its use as a solid lubricant, molybdenum disulphide (MoS2) has gained recent attention as a possible substitute for silicon as it is increasingly difficult to keep shrinking down electronic devices made of silicon, the conventional electronic material. When thinned down to atomic thickness, monolayer MoS2 possesses very unique and promising electronic and electrical properties. Unlike electronic and electrical properties, knowledge of the mechanical properties and role of structural defects on these properties of monolayer MoS2 is unexplored. For this thesis, the two main objectives are (1) to gain insight about the failure mechanism of monolayer MoS2 by …

The Investigation Of Cold-Mix Asphalt Creep Stiffness Testing Using Multiple Test Apparatuses And Gradations, Alexander Jackson

Graduate Theses and Dissertations

Many current methods of designing and testing Cold In-Place Recycled (CIR) asphalt are undesirable because they require large amounts of material and significant preparation. In an effort to lessen the cost and time of materials testing, this research utilizes several different methods of small scale testing of creep stiffness. These methods include using a Discovery Hybrid Rheometer (DHR) and a three point bending test to find the creep stiffness of emulsion based CIR. The new testing methods utilized samples on the scale of up to a hundredth the size of what the traditional methods of testing require. The two smaller …

The Characterization Of Foamed Asphalt Binders Using A Rotational Viscometer, John William Ryan

Graduate Theses and Dissertations

Foamed asphalt is a popular technic of vaporizing water into asphalt binder that falls under the umbrella term of warm-mix asphalt. In order to understand how to adjust mix designs for the use foamed asphalt, methods must be developed for characterizing different foamed asphalt binders. One way to characterize the asphalt binder is through viscosity testing using a rotational viscometer. The standard method of using a viscometer to measure the viscosity of asphalt binder is insufficient when dealing with foamed asphalts, so a new method has been created along with 4 metrics to analyze the data to characterize foamed asphalt …

Validation Of A Diffuse Reflectance Microendoscope With Polydimethylsiloxane Optical Phantoms And Monte Carlo Modeling, Gage Joseph Greening

Biomedical Engineering Undergraduate Honors Theses

We have introduced a method for creating thin-film PDMS optical phantoms that can be used to validate a bench-top optical device called a Diffuse Reflectance Microendoscope (DRME). The DRME is acquires data on cell surface morphology and sub-surface diffuse reflectance, which may provide clinicians with the tools to diagnose oral cancer at earlier stages. Phantoms were created with PDMS. Optical properties of the phantoms were controlled with the addition of nigrosin and titanium dioxide. Depth of phantoms was controlled by a spin coater. The DRME was built with a combination of filters and dichroic mirrors to separate electromagnetic radiation in …

Poly (Glycerol Sebacate) Nanofibers And Nanofilms For Tissue Engineering Application, Stephanie Grace Cone

Biomedical Engineering Undergraduate Honors Theses

In the field of tissue engineering, the development of biodegradable scaffolds that provide both structure and functionality is a major challenge. The use of biological implants, such as decellularized tissues, provides a complete matrix with full tissue functionality, however, problems with immunogenicity often arise when implants from other organisms are used in treatments. As such, there are many benefits to the use of polymeric constructs in tissue engineering. The ability to customize the material, design, and size of an implant provides opportunities for increased structural support and controlled rates of biodegradation. The selection of polymers for tissue engineering applications requires …

A Peptoid-Based Targeted Drug Delivery System For The Treatment Of Metastatic Cancer, Hugh M. Purdy

Chemical Engineering Undergraduate Honors Theses

Development of a targeted drug delivery system is a critical step in the effort to improve cancer treatments. Such a system would greatly reduce the harmful side effects of chemotherapy by delivering toxic drugs directly to cancerous cells. Peptoids—synthetic compounds that can be easily produced from readily available amine monomers—have great potential for use in targeted drug delivery. This project aimed to develop peptoids that would bind to specific proteins expressed on the surface of cancer cells. These peptoids could be combined into a complex that would bind to the proteins with an even greater affinity than the individual compounds. …

Classification And Quantification Of Phenotypic Characteristics Of Normal And Dysplastic Oral Cells, Jackson W. Boice

Biomedical Engineering Undergraduate Honors Theses

Introduction Oral cancer accounts for 2.5% of all cancer cases in the United States. The 5 year survival rate or stage 1 or localized oral cancer is 82%, and the survival rate of unstaged oral cancer is only 50%; therefore, early diagnosis is key. Current clinical practices for determining malignancy of tissue include physical examination and surgical biopsy, which can be plagued by high variability between observers and are invasive for the patient. Proflavine intercalates between base pairs of nucleic acids and has excitation and emission peaks at 455 (+/- 20) nm and 515 nm respectively; therefore, it can be …

Optimizing In Vitro Extracellular Matrix Production Using Polymer Scaffolds With Targeted Pore Size, Addison M. Walker

Biomedical Engineering Undergraduate Honors Theses

Extracellular matrix (ECM) has been shown to provide the framework needed for healthy tissue to grow after experiencing an injury. The optimization of growing ECM is a pressing concern in the tissue regeneration field. From prior research, an in vitro approach for harvesting ECM has been created using polyurethane (PU) foams seeded with cells. Our approach aimed at discovering if the pore size of the foams increased the amount of recovered ECM. Scaffolds of targeted pore size were created by separating sugar granules using a sieve, packing the sugar into a cylindrical mold, then pouring PU over the sugar. Three …

Models For Incorporating Block Scheduling In Blood Drive Staffing Problems, Yulong Su

Industrial Engineering Undergraduate Honors Theses

The purpose of this research is to develop decision support models that can be used by the American Red Cross (ARC) to schedule blood drives with improved shifts for the phlebotomists that staff them. Currently, phlebotomists work inconsistent hours and the ARC believes this is a leading cause of high turnover rates they are experiencing. For example, phlebotomists sometimes staff a blood drive until 11 PM one night and will have to work another at 8 AM the next morning. Assigning phlebotomists more consistent shifts in blocks of time will definitely improve their work schedule. Before switching to block scheduling, …

Uncertainty In Relief Supply Distribution, Christopher A. Bayles

Industrial Engineering Undergraduate Honors Theses

In the aftermath of a natural disaster the efficient planning of humanitarian relief efforts, e.g., delivering supplies to locations in need, can often mean the difference between lives being saved and lives being lost. In this paper we focus on two things: (1) appropriate objectives for routing problems in the context of delivery of relief supplies, and (2) how to handle the uncertainty associated with delivery of relief supplies after a disaster. Through applying uncertainty to parameters such as travel time between locations, we seek to examine if/how optimal routes change as a result of different objectives and the presence …

How Imbalanced Excitation And Inhibition May Cause Low Entropy Brain Dynamics, Qusay Redwan Alfaori

Biomedical Engineering Undergraduate Honors Theses

To study the effect of the imbalance of excitation and inhibition neurons on brain entropy using a computer model of a brain. The brain model will be composed of a neural network and entropy of the neural network will be measured quantitatively. Entropy in this context quantifies how many different patterns of activated neurons the brain can create. Imbalance between excitation and inhibition neurons causes the brain to malfunction, which can be an underlying cause of autism.

5ht And The 5ht Receptors- Relevance To Cardiac Valve Disease, Christopher Ryan Martindale

Biomedical Engineering Undergraduate Honors Theses

Recent studies have revealed that elevated levels of serotonin or 5HT lead to valve dysfunction. A mouse model was successfully established to investigate the effects on the aortic valve in subjects with elevated 5HT levels along with cardiovascular hypertension. For each two-week trial, eight C57BL/6J mice were divided into the following expermental groups: control, 5HT, angiotensin II, and 5HT+angiotensin II. The drug was delivered to the mice via osmotic pumps (Ang II: 0.4ng/g/min, 5HT:0.0025ng/g/min) or direct injections(Ang II: 0.1 mg, 5HT: 2.12 mg, every other day) and the blood pressure of the mice was continually monitored via the CODA tail …

Fluorescence Imaging Of Microdialysis Sampling, Jordan Leigh Haynie

Chemical Engineering Undergraduate Honors Theses

Many biomolecules including proteolytic enzymes known as matrix metalloproteinases (MMPs) are released when a material, such as a microdialysis probe, is implanted in a living organism. The MMPs cleave structural protein components of the extracellular matrix and play an important role in biological functions such as wound healing.1-3 Many enzymatic substrates for MMPs have fluorescent product mimics, and the mimics can be used as agents to monitor biochemical processes.1 In this study, microdialysis, a minimally invasive sampling technique, was combined with fluorescence imaging to determine the possibility of monitoring microdialysis in real-time, and thus provide a method that could ultimately …

Water System For Developing Countries / Disaster Relief Made With Local Materials, Keiron Anton Hamilton Durant

Chemical Engineering Undergraduate Honors Theses

My main duty for the project was to design various tests to assess the quality of the water and to assure that the water we were producing complies with the World Health Organization’s standards. I was responsible for researching these requirements and communicating with experts in the field so that our team could make logical decisions as to how the design should be altered. The first professor I had interactions with was Dr. Julian Fairy who is a civil engineering expert in waste water treatment. He advised us on our entire system design and effective ways for testing the chlorine …

Biobotic Solutions, Michael Joseph Iseman

Finance Undergraduate Honors Theses

BioBotic Solutions is a business plan that was created and used to compete in national business competitions. The business takes an in-depth look into the pathology industry, which has an impact on nearly 75% of all patient diagnosis, and proposes a change- to automate a process currently done manually, and introduce to proprietary products, a robotic arm and a new container. The solution addresses a $500M annual opportunity, and will reduce both errors and costs for mid/large size laboratories.

Discrete Strain Engineering In Graphene, Cedric Marcus Horvath

Graduate Theses and Dissertations

Graphene has a number of fascinating mechanical and electrical properties. Strain engineering in graphene is the attempt to control its properties with mechanical strain. Previous research in this area has come up with an approach using a continuum theory to describe the strain induced gauge fields in graphene; however, this approach is only valid for small strains (5% at most). A discrete framework is being developed in Arkansas that can more accurately calculate the deformation (electrical) and (pseudo-)magnetic gauge fields created by large strains. Computational simulations were carried out and used to get discrete atomic positions for strained, suspended graphene …

Detailed Inventory Record Inaccuracy Analysis, Hayrettin Kaan Okyay

Graduate Theses and Dissertations

This dissertation performs a methodical analysis to understand the behavior of inventory record inaccuracy (IRI) when it is influenced by demand, supply and lead time uncertainty in both online and offline retail environment separately. Additionally, this study identifies the susceptibility of the inventory systems towards IRI due to conventional perfect data visibility assumptions. Two different alternatives for such methods are presented and analyzed; the IRI resistance and the error control methods. The discussed methods effectively countered various aspects of IRI; the IRI resistance method performs better on stock-out and lost sales, whereas error control method keeps lower inventory. Furthermore, this …

Designing Customizable Network-On-Chip With Support For Embedded Private Memory For Multi-Processor System-On-Chips, Azad Fakhari

Graduate Theses and Dissertations

The computer industry's transition to multiprocessor systems on chip (MPSoC) architectures is increasing the need for new scalable high-bandwidth on-chip communication

backbones. Network-on-Chip (NoC) interconnects are gaining interest for serving as the on-chip communication infrastructure. The most important issues to be considered in designing a NoC are topology, routing algorithm, flow control, and buffering and also the trade-offs between performance, power, and area.

This research proposes a custom-designed NoC specifically for MPSoCs on FPGAs. The proposed design allows the communication infrastructure to seamlessly scale as the numbers of processors within the chip increases. The design adds a new level of …

Modeling Of An Oxygenation-Aided 3d Culture For Functional Beta-Cell Expansion, John Lance Mcreynolds

Biomedical Engineering Undergraduate Honors Theses

Introduction: Diabetes affects millions of people and its prevalence is increasing by 2-5% per year. A promising method for the control of diabetes is the transplant of pancreatic β-cell mass. Unfortunately, there is a shortage of the donor tissue that is needed to replace β-cell mass. A potential source of β-cells is the production of β-cells in vitro, but the proliferation rate of β-cells is very slow and elevating the proliferation rate can result in loss of cell function. We observed that β-cells benefit from being cultured in a 3D environment, but in the 3D culture the β-cells often die …

A Swat Model For A Cocoa Growing Region In Ghana, Russell Thomas Bair

Biological and Agricultural Engineering Undergraduate Honors Theses

For agricultural outputs to rise with population, more sustainable and productive methods must be identified. Watershed modeling is a way to relatively quickly compare possible impacts of large scale agricultural practice changes. The goal of this project was to develop a watershed model for the Pra River basin in southern Ghana, a cocoa growing region, that could be used for future impact studies of land management practice options. The model was developed using the Soil Water Assessment Tool (SWAT) and calibrated using the best daily stream flow data that could be readily located. With an R2 value of 0.57 and …

Beginning Of Malignant Tumor Cells, Emily K. Shields

Biomedical Engineering Undergraduate Honors Theses

Despite advances in cancer treatments, cancer is still ranked the second leading cause of death. Cancers are started by cancer stem cells (CSCs). CSCs, also called tumor-initiating cells, are found in tumors and are responsible for the growth of tumors and the spread of cancer to other parts of the body. CSCs are very resistant, and cannot be killed by chemotherapy or radiation treatments. These cells can come from healthy stem cells. The environment surrounding the healthy stem cells and mature cells can cause mutations in the cell’s genetics, resulting in development of CSCs. The environment can also increase tumor …

Fabrication Of Nanoscale Features On Surfaces, James C. Proctor

Chemical Engineering Undergraduate Honors Theses

A method to form nanofeatures on the surface of a material by utilizing a prefabricated polymer nanostructures is proposed. A means by which the polymer structures can be produced is discussed. The advantages and disadvantages of this process and other nanolithography processes are evaluated.

Coal Fires: An Environmental Disaster, Edward K. Jenner

Chemical Engineering Undergraduate Honors Theses

Coal Fires are an environmental disaster.

Coal Fires: An Environmental Disaster, Carolyn Schardt

Chemical Engineering Undergraduate Honors Theses

Coal Fires are part of an environmental disaster.