Engineering Commons^™

Design And Verification Of Search Coil Inductance For Pulse Induction Metal Detection, David Desrochers

Electrical Engineering Undergraduate Honors Theses

As violent attacks have increased at different venues such as schools, the need for affordable and effective metallic weapon detection has increased. Probing and scanning detection wands are the most common seen in use by guards. This project seeks to combine both probing and scanning coils into one pulse induction metal detector. The use of one drive circuit for both LC coil tank circuits further economizes the system. ANSYS Maxwell electromagnetic simulations are used to develop the geometries needed for sensitive metal detection. Analytical, simulation, and experimental methods are used to first verify the design flow for solenoid inductors. These …

A Capacitive Sensing Gym Mat For Exercise Classification & Tracking, Adam Goertz

Computer Science and Computer Engineering Undergraduate Honors Theses

Effective monitoring of adherence to at-home exercise programs as prescribed by physiotherapy protocols is essential to promoting effective rehabilitation and therapeutic interventions. Currently physical therapists and other health professionals have no reliable means of tracking patients' progress in or adherence to a prescribed regimen. This project aims to develop a low-cost, privacy-conserving means of monitoring at-home exercise activity using a gym mat equipped with an array of capacitive sensors. The ability of the mat to classify different types of exercises was evaluated using several machine learning models trained on an existing dataset of physiotherapy exercises.

Image Enhancement And Restoration For Colonoscopy Images, Sarah Paracha

Computer Science and Computer Engineering Undergraduate Honors Theses

Colonoscopy images contain specular highlights that occur as a result of the tiny camera on the colonoscope being perpendicular to the image location. These specular highlights may prevent the Gastroenterologist from having a full picture of the patient’s condition and potentially giving an early diagnosis. The purpose of my honors research is to remove the specular highlights from these colonoscopy images.

The process to achieve the above objective involves two steps. The first step would require locating the specular highlights in the image through image segmentation. For this purpose, information from nearby x and y pixels may be utilized. The …

Methods Of High-Fidelity, High-Efficiency Class-D Audio Amplification, Kaleb Kassaw

Electrical Engineering Undergraduate Honors Theses

Gallium nitride-based field effect transistors (FETs) have opened a path for full-frequency-range class-D audio amplifiers with low distortion and noise, thanks to their ability to switch at much higher frequencies than that of the upper range of human hearing. Compared to traditional silicon-based transistors, GaN-based transistors offer superior efficiencies, particularly at power levels below their maxima. Paired with an analog-to-digital converter, digital signal processor, and pulse-code modulation to pulse-width modulation converter, these transistors are used to design and implement a solid-state amplifier capable of generating 100 watts of output through speakers with an impedance of 8 ohms using a 1-volt …

Smart Textiles As The Digital Interface Of The Future, Audra Beneux

Electrical Engineering Undergraduate Honors Theses

The growing field of smart textiles could change everyday life, adding an element of interactivity to commonly used items such as clothing and furniture. Smart textiles measure then respond to external stimuli. For scalability in the future, smart textiles must be produced using conventional textile manufacturing craftsmanship. The resulting textile must be durable and comfortable while retaining electrical capabilities. Smart textiles can be fabricating through embroidery, weaving, and knitting using conductive threads. Electronics can also be printed onto textiles. Researchers are also creating higher-order electronics, such as the transistor, on the fiber-level to make the technology in smart textiles as …

Ohmic Contact Metallization For Silicon Carbide In Future Transportation And Aviation Systems, Tanner W. Rice

Electrical Engineering Undergraduate Honors Theses

This paper analyzes metallization stacks in both n-type and p-type used in Silicon Carbide to create Ohmic Contacts. Silicon Carbide has shown its significance in usage as a semiconductor in high temperatures, and other extreme environments compared to its silicon counterpart. Additionally, silicon carbide exhibits many other favorable attributes such as strong radiation hardness, high power capability, and high-temperature tolerance. These attributes translate into great components for use in aviation and other future transportations by increasing reliability in a sector that already requires high reliability. Applications of this material could prove useful in fields such as aviation, among others. This …

Simultaneous Ohmic Contacts To N And P-Type Silicon Carbide For Future Electric Vehicles, Hayden Hunter

Electrical Engineering Undergraduate Honors Theses

The paper explores possible metallization schemes to form simultaneous ohmic contacts to n-type and p-type silicon carbide contacts. Silicon carbide has shown promise in revolutionizing the power electronics market due to its increased switching speed, compact design, and higher temperature tolerance when compared to Silicon, the market standard. With the continuing development of silicon carbide technology, higher efficiency in future electric vehicles can be achieved by employing this new technology. This paper discusses theoretical contact formation between metals and semiconductors along with a proposed experiment to create a Ni/Al metallization scheme on both n and p-type contacts simultaneously on a …

Lexicon Based Approaches To Sentiment Analysis Of Spanish Tweets: A Comparative Study, Jean Roca

Computer Science and Computer Engineering Undergraduate Honors Theses

Sentiment analysis is a natural language processing technique that aims to classify text based on the emotions expressed in them. It is a research area that has been around for almost 20 years and has seen a lot of development. The works presented in this paper attempts to target a less-developed area in sentiment analysis known as multilingual sentiment analysis. More specifically, multilingual sentiment analysis of micro-texts. Using the existing WordNet lexicon and a domain-specific lexicon for a corpus of Spanish tweets, we analyze the effectiveness of these techniques.

Extremely Low Cycle Fatigue Behavior Of Additively Manufactured 17-4ph Stainless Steel, Kaley Collins

Civil Engineering Undergraduate Honors Theses

Steel structures survive seismic loading thanks to components capable of dissipating large amounts of energy through large deformations. Future optimizations of these components include complex free-form geometries that are difficult to fabricate with traditional casting processes. Additive manufacturing (AM) is an alternative for producing optimized free-form geometries. AM material contains significant differences in microstructural characteristics and mechanical behavior compared to its wrought counterparts. Research has been conducted to understand the effect of microscopic features in the high cycle fatigue (HCF) and low cycle fatigue (LCF) regimes. This study focuses on the behavior of 17-4 Precipitation Hardening (PH) stainless steel in …

Analysis Of Blood Purification Studies On Oxone Mediated Tempo-Oxidized Nano Cellulose Mixed-Matrix Membranes, Tony Roller

Biomedical Engineering Undergraduate Honors Theses

End-stage renal disease (ESRD) is currently the ninth leading cause of death in the United States, and of the 661,00 Americans diagnosed with ESRD, approximately 468,800 were on hemodialysis in 2016. Hemodialysis refers to a technique where a machine combined with a membrane, often referred to as an artificial kidney, is used to clean blood by removing any waste such as urea, potassium, and other smaller waste products while preserving the concentrations and integrity of cells and proteins in the blood. It has been shown in artificial blood studies that cellulose nanomaterials, like TEMPO/Oxidized cellulose nanoparticles (TOCNs), can be integrated …

Reducing Emi In Sic Direct Torque Controlled Motor Drive, Michael Sykes

Electrical Engineering Undergraduate Honors Theses

This paper covers the comparison between Silicon (Si) vs Silicon Carbide (SiC) for Motor Drive systems and a possible control algorithm to limit the increased Electromagnetic Interference (EMI) caused by using SiC transistors for the inverter. Motor Drive systems need constant improvements if the world is going to move on from machines that emit CO₂ and other harmful gases into the Earth’s atmosphere. One reason these electric machines are not commonplace today is because of their efficiency and other problems they may cause. Silicon transistors are the most commonplace transistor around the world today, but advances over the past …

Autofluorescence Spectral Unmixing For Quantitative Metabolic Imaging Within Tissues, Lucy Woodbury

Biomedical Engineering Undergraduate Honors Theses

Label-free metabolic imaging through quantification of NADH and FAD autofluorescence has become a powerful and efficient tool for non-invasive measurements of cell metabolism. It has applications in a variety of fields including diagnostic and therapeutic monitoring. However, NADH and FAD imaging typically selects specific single excitation and emission bands where it is assumed that these fluorophores are individually isolated. In some cases of isolated cell imaging, this assumption holds true, but for samples with other intrinsic fluorophores present (i.e. collagen and elastin), it can interfere with quantitative results. Elastin and collagen autofluorescence prevent the broader application of these optical metabolic …

On The Seismic Performance Of Skewed Special Moment Frame Reduced Beam Section Connections, Damaso Daniel Dominguez

Graduate Theses and Dissertations

Special Moment Frames (SMFs) are frequently used in high seismic areas for architecturally constrained designs, as they provide lateral system stiffness without the use of braces which often obstruct views and architectural features. Reduced beam section (RBS) connections are popular SMF connection details developed following the Northridge earthquake to limit brittle fractures within connection welds. Current American Institute of Steel Construction (ASIC) provisions (i.e. AISC 341-16) provide prequalified SMF RBS connection details (including welding requirements); however, all prequalified details only consider orthogonal connections between the beam and column. This dissertation investigates the effect of adding skew within SMF RBS connections …

Development Of Vs Profiles And Site Periods In The Mexico City Basin, Landon Joel Woodfield

Graduate Theses and Dissertations

This study presents dynamic site characterization measurements at 25 sites within the Mexico City Basin. The primary focus of the testing was along the western edge of the Mexico City Basin. At each site, active source Multi-channel Analysis of Surface Waves (MASW) arrays and passive source Microtremor Array Measurements (MAM) L-arrays and circular arrays were used to acquire dispersion data. Horizontal to Vertical Spectral Ratio (HVSR) data was collected to determine site periods at each location. These experimental dispersion data and site periods were fit using a joint inversion of Rayleigh and Love wave dispersion data and HVSR site period …

Numerically Modeling Steel Continuous Bridges For Early Age Concrete Deck Cracking, Abdul Aziz Nabil Salah

Graduate Theses and Dissertations

Early age bridge deck cracking is a common problem throughout the United States. Early age cracking develops shortly after the deck is poured. It reduces the serviceability and lifespan of bridges. Early age cracking can be typically attributed to either of two factors, 1) construction practices, and 2) shrinkage. The Arkansas Department of Transportation (ARDOT) has experienced early age bridge deck cracking. ARDOT currently specifies a sequence deck pour on most of their bridges; however, contractors prefer continuous deck pours because of ease and construction time. During the period of this TRC1903 research project, ARDOT has only approved a few …

Numerical Simulations Of Spread Foundations Supported On Stone Columns Using The Discrete Element Method, Anibal Enrique Santos Marin

Graduate Theses and Dissertations

The implementation of stone columns as a ground improvement technique has become more popular in geotechnical construction practice as a result of their ability to improve strength, stiffness and permeability characteristics of weak clayey soil deposits. There are several analytical and empirical approaches to estimate the bearing capacity of stone column foundation systems; however, there is notable variation in the performance of these existing methods when compared with full-scale experimental results. For very weak cohesive soils (i.e., undrained shear strength less than 15 kPa), the use of conventional stone columns becomes restricted because of the insufficient confinement that these types …

Best Practices For Asphalt Emulsion Particle Size Analyses Using A Coulter Counter, Logan P. Kiihnl

Graduate Theses and Dissertations

As asphalt pavements develop distresses, pavement preservation, maintenance, and rehabilitation treatments are used to mitigate distresses and extend the life of the pavement. Many of these treatments utilize asphalt emulsion. Previous research has linked particle size to material properties including viscosity and storage stability. General statements have also been made about particle size influencing emulsion performance while other researchers have identified a trend between particle size and prime coat penetration. Even though literature discusses the importance of particle size, there is little guidance on the best practices of asphalt emulsion particle size analyses, specifically with a Coulter counter.

Data collected …

Development Of Multi-Axial Fatigue Retrofits For Lock Gate Components, Logan Verkamp

Graduate Theses and Dissertations

Lock gates are essential infrastructure components to the United State (US) supply chain. They create large cost savings and environmental benefits when compared with traditional methods of transport (freight and rail). Because of the large quantity of goods and dependence on these shipping chains, the US economy can be drastically affected by an unexpected gate closure. Unfortunately, many lock gates within the US have reached or exceeded their designed life. Due to the intensity of cyclic loads and the environment, fatigue cracks have become a prominent issue. Developed cracks near the pintle region (a joint which the gate rotates and …

Electrodialysis Device For In Vivo Power Delivery, Jessica L. Orton

Biomedical Engineering Undergraduate Honors Theses

It is estimated that over 3 million cardiac pacemakers have been implanted in patients globally. Current lithium-iodine pacemaker batteries last an average of about 10 years before the entire pacemaker unit must surgically be replaced, increasing the patient’s risk of procedure-related complications. Therefore, it is necessary to investigate means by which to extend the pacemaker battery lifetime. The renal vein and renal artery in the body naturally produce a salinity gradient through the filtering work of the kidneys. This salinity gradient energy potential can be harnessed through reverse electrodialysis (RED). RED is an electrochemical process that harnesses the Gibbs Free …

Development Of A Matlab Gui To Assist The Active Comprehension Of Biomedical Transport Phenomena Using A Visual Aid, Pranav Suri

Biomedical Engineering Undergraduate Honors Theses

Studies show that inductive teaching methods for Biomedical Transport Phenomena greatly benefit from an accompanying visual aid. The following project aimed to develop a MATLAB GUI application that illustrates steady-state heat transfer with a graph and heat map using user-defined boundary conditions and numerical parameters. The application was evaluated using a survey that first familiarized the user with the GUI by running through heat transfer exercises, then allowed the user to experiment with the application, and finally asked users about their experiences using a questionnaire. The responses indicate that the GUI was received positively overall, and that a MATLAB component …

Stirred Suspension Bioreactor Differentiation Of Human Mesenchymal Stem Cells Into Smooth Muscle Cells, Chris Slavin

Biomedical Engineering Undergraduate Honors Theses

Human mesenchymal stem cells (hMSCs) are a promising candidate for cellular therapies due to their multipotency, self-renewal capacity, and immunomodulatory properties. However, their isolation is a difficult and potentially painful process with very low yield, and traditional static mammalian cell culture techniques are too slow and expensive for large scale growth and differentiation of stem cells to be practical. Current research is focused on improving methods for cultivating hMSCs in stirred suspension bioreactors (SSBs), but little work has been done with regard to their differentiation in dynamic conditions such as those in SSBs. Differentiation at a large scale would increase …

The Response Of Astrocytes To Mechanical Stimuli, Courtney Bahan

Biomedical Engineering Undergraduate Honors Theses

Traumatic brain injuries are a common cause of injury and result from a blow to the head whether it be blunt, penetrating, or inertial. TBIs are typically obtained in a fall, while playing a sport, or in a car crash. TBIs can be diagnosed as mild (commonly referred to as a concussion), moderate, or severe based upon their score from the Glasgow coma scale. TBIs can also lead to other risks such as epilepsy or Alzheimer’s Disease as well as increasing the risk of suffering another TBI. Astrocytes are heterogeneous glial cells in the brain that alter their response based …

Locating Relay Nodes To Maximize Wireless Sensor Network Lifetime: A Numerical Study, Maria Rene Arandia Jimenez

Industrial Engineering Undergraduate Honors Theses

A wireless sensor network (WSN) is a group of sensors deployed over an area, which monitor changes in the environment, collects them as data and forwards it between sensors through wireless links. Data is routed, either in a single-hop or multi-hop manner, with the goal of getting this collected data to the sink nodes, which have higher computational capabilities and connects the network with a user interface. Studies have determined that multi-hop WSNs that integrate relay nodes, which function is to only receive and forward data, can maximize lifetime network. A linear programming model, created by Chang and Tassiulas in …

Maximizing The Academic And Professional Success Of First-Generation College Students In Biomedical Engineering, Mona Ahmed

Biomedical Engineering Undergraduate Honors Theses

Although efforts to increase the inclusion, retention, and success of first-generation college students (FGCSs) in research universities have resulted in noticeable progress, FGCSs still feel academically challenged, isolated, and show more anxiety and depression compared to non-FGCSs. Moreover, FGCSs may possess additional underrepresented identities that exacerbates the problem. There is more risk of dropping out of academic programs for FGCSs enrolling in STEM degrees, especially those of more multidisciplinary nature such as Biomedical Engineering. From the overall population of the State of Arkansas, only 23.3% have a bachelor’s degree or higher which is the third least percentage in the United …

Optical Metabolic Imaging As A Predictor Of Patient Tumor Response To Therapy And Apoptosis, Andrew Larey

Biomedical Engineering Undergraduate Honors Theses

Despite a plethora of medical advancements, malignant tumors remain difficult to treat due to complex cancer biology and interpatient heterogeneity. Phenotypically similar tumors may respond differently to a given treatment. In clinical oncology, it is paramount to quantify tumor response to therapy for predicting treatment outcome, monitoring tumor changes, identifying effective therapies, and avoiding unnecessary cost and toxicity to the patient. Current standards of monitoring tumor response to therapy include CT, MRI, PET, and histopathology; these methods either take a merely anatomical approach or are invasive and time consuming, necessitating a functional biomarker approach. MPM represents a metabolic-level method of …

Improving Offensive Player Performance Measures For Assessing Free Agent Major League Baseball Players, Henley Wells

Industrial Engineering Undergraduate Honors Theses

Professional sports teams are important to their local economies, so successful franchises are significant contributors to their prosperity. This need for successful teams drives the owners and general managers to perform in-depth analyses on potential players to gain insight, so the best players can be chosen. Major League Baseball is one of the largest sports leagues in the world, so their analysis of players must be excellent to ensure they sign the best players and can compete at a high level.

Baseball is a complex sport with many different statistics evaluating nearly every part of a player’s game. Because of …

Curriculum Optimization Via Activity-On-Node Network Modeling, Caroline Rhomberg

Industrial Engineering Undergraduate Honors Theses

University degree plans must be carefully planned so that they allow students the best chance of succeeding. Although for the better, with the advancement of technology and its incorporation into the classroom, it can be argued that the complexity and difficulty of some long-established engineering core classes has changed. With this trend certain combinations of engineering courses have become unfavorable in terms of course withdrawal and fail rates stemming from the interaction of course challenges. A wealth of data has been collected on this topic and will be utilized in this project. As one can imagine, the probability of success …

Characterizing Statin Use Among Prediabetic Patients With Predictive Analytics, Alexandra Gentile

Industrial Engineering Undergraduate Honors Theses

Diabetes is one of the leading causes of death in the United States and can cause severe impairments to those diagnosed. Prediabetes is a state when a patient has higher fasting plasma glucose levels than a non-diabetic person but is not quite high enough to be considered diabetes. Both diabetic and prediabetic patients are at higher risk for cardiovascular diseases (CVD), which is the leading cause of death in the United States. The primary form for prevention and treatment of CVD is through statin therapy. Statins are a class of medications used to treat and prevent CVD by limiting cholesterol …

Optimal Emergency Response Shelter Placement Based On Population Vulnerabilities, Alexander Johnson

Industrial Engineering Undergraduate Honors Theses

Hurricane Florence was a category 4 storm which caused an estimated $24 billion in damages and the loss of 53 lives. During and immediately following Florence, there were 235 shelters operating in and around the North Carolina (NC) area. These were used as temporary housing for storm victims and by emergency responders to distribute relief supplies and provide medical services. Emergency officials consider several factors when deciding where to open shelters, including, for example, proximity of victims and their levels of medical needs. Access disparities, or factors creating barriers that limit entry to shelters, put certain populations and regions at …

A Simulation Approach To Evaluate The Impact Of Breast Cancer Overdiagnosis On Patient Outcomes, Sierra Wagner

Industrial Engineering Undergraduate Honors Theses

Breast cancer overdiagnosis risk is difficult to estimate and varies significantly across current research. This research establishes a simulation approach to examine the relationship between breast cancer overdiagnosis and patient outcome and understand the impact that the range of breast cancer overdiagnosis rate estimates in the current literature has on patient outcomes. Overdiagnosis is represented in this study by a set of disease regression probabilities. Using microsimulation, we evaluate patient outcome, measured by number of mammograms and lifetime breast cancer mortality risk, as a function of treatment policy and regression probability. We use numerical experiments to evaluate treatment policies and …