Engineering Commons^™

Wind Tunnel Modeling Of Jack Rabbit Ii Mock Urban Environment Gas Concentration Measurements, Sami S. Fares

Graduate Theses and Dissertations

The 2015 Jack Rabbit (JR) II field trials were conducted to improve understanding of the denser-than-air dispersion of chlorine in an urban environment. The field study involved five large-scale, outdoor release trials of chlorine in a mock urban environment (MUE) at Dugway Proving Ground (DPG). Various instrumentation was deployed, including JazTM Ultraviolet-Visible (UV-Vis) point sensors capable of measuring gas-phase chlorine concentration throughout the mock urban array.

The Chemical Hazards Research Center (CHRC) was tasked by the Chemical Security Analysis Center (CSAC) with the Mock Urban Wind Tunnel (MUWT) program to study the 2015 JR II Trials at wind tunnel scale. …

Incorporating Immersive Learning Into Biomedical Engineering Laboratories Using Virtual Reality, Megan Wilkerson, Vitali V. Maldonado, Srikanth Sivaraman, Raj R. Rao, Mostafa Elsaadany

Biomedical Engineering Faculty Publications and Presentations

Background

The Covid-19 pandemic caused a sudden shift towards remote learning, moving classes to online formats. Not exempt from this switch, laboratory courses traditionally taught in-person were also moved to remote methods, costing students the opportunity to learn these skills hands-on. In order for instructors to provide course materials effectively and engagingly, non-traditional methods should be explored.

Virtual reality (VR) has become more accessible in recent years. VR simulations have been used for many years as educational tools in high-risk settings such as flight or medical simulations. Immersive VR videos implemented in a remote laboratory course could provide the students …

In Vitro Blood Clot Formation And Dissolution For Testing New Stroke-Treatment Devices, Kayla Wood, Sam E. Stephens, Feng Xu, Alshaimaa Hazaa, James C. Meek, Hanna K. Jensen, Morten O. Jensen, S. Ranil Wickramasinghe

Biomedical Engineering Faculty Publications and Presentations

Strokes are among the leading causes of death worldwide. Ischemic stroke, due to plaque or other buildup blocking blood flow to the brain, is the most common type. Although ischemic stroke is treatable, current methods have severe shortcomings with high mortality rates. Clot retrieval devices, for example, can result in physically damaged vessels and death. This study aims to create blood clots that are representative of those found in vivo and demonstrate a new method of removing them. Static blood clots were formed using a 9:1 ratio of whole sheep blood and 2.45% calcium chloride solution. This mixture was heated …

Study Of Single-Photon Wave-Packets With Atomically Thin Nonlinear Mirrors, Christopher Klenke

Graduate Theses and Dissertations

A novel controlled phase gate for photonic quantum computing is proposed by exploiting the powerful nonlinear optical responses of atomically thin transition metal dichalcogenides (TMDs) and it is shown that such a gate could elicit a π-rad phase shift in the outgoing electric field only in the case of two incident photons and no other cases. Firstly, the motivation for such a gate is developed and then the implementation of monolayer TMDs is presented as a solution to previous realization challenges. The single-mode case of incident photons upon a TMD is derived and is then used to constrain the more …

A Snapshot Of Sars-Cov-2 In Wastewater Treatment Plants In Northwest Arkansas, Katie Loethen

Biological and Agricultural Engineering Undergraduate Honors Theses

Because SARS-CoV-2, a coronavirus, is released in the fecal shedding of covid-positive patients, the virus enters the municipal waste stream and flows to wastewater treatment plants (WWTPs). The goal of this research is to quantify the effectiveness of wastewater treatment processes at removing SARS-CoV-2 from wastewater and preventing its release into the environment. Sampling at Paul R. Noland and West Side WWTPs in Fayetteville, Arkansas, took place from August 2020 to May 2021, and samples were tested for the presence of SARS-CoV-2 using N1 and N2 primers via RT-qPCR. Sampling days which returned positive detection of one or both of …

Spiking Neural Networks And Their Applications: A Review, Kashu Yamazaki, Viet-Khao Vo-Ho, Darshan Bulsara, Ngan Le

Computer Science and Computer Engineering Faculty Publications and Presentations

The past decade has witnessed the great success of deep neural networks in various domains. However, deep neural networks are very resource-intensive in terms of energy consumption, data requirements, and high computational costs. With the recent increasing need for the autonomy of machines in the real world, e.g., self-driving vehicles, drones, and collaborative robots, exploitation of deep neural networks in those applications has been actively investigated. In those applications, energy and computational efficiencies are especially important because of the need for real-time responses and the limited energy supply. A promising solution to these previously infeasible applications has recently been given …

Electrospun Hydrophobic Interaction Chromatography (Hic) Membranes For Protein Purification, Shu-Ting Chen, Sumith Ranil Wickramasinghe, Xianghong Qian

Chemical Engineering Faculty Publications and Presentations

Responsive membranes for hydrophobic interaction chromatography have been fabricated by functionalizing poly(N-vinylcaprolactam) (PVCL) ligands on the substrate of electrospun regenerated cellulose nanofibers. Both static and dynamic binding capacities and product recovery were investigated using bovine serum albumin (BSA) and Immunoglobulin G (IgG) as model proteins. The effects of ligand chain length and chain density on static binding capacity were also studied. A static binding capacity of ~25 mg/mL of membrane volume (MV) can be achieved in optimal ligand grafting conditions. For dynamic binding studies, protein binding capacity increased with protein concentration from 0.1 to 1.0 g/L. Dynamic binding capacity increased …

Development Of Ltcc-Packaged Optocouplers As Optical Galvanic Isolation For High-Temperature Applications, Pengyu Lai, David Gonzalez, Syam Madhusoodhanan, Abbas Sabbar, Salahaldein Ali Aboajila Ahmed, Binzhong Dong, Jiangbo Wang, H. Alan Mantooth, Shui-Qing Yu, Zhong Chen

Electrical Engineering Faculty Publications and Presentations

This paper reports high-temperature optocouplers for signal galvanic isolation. Low temperature co-fired ceramic (LTCC) technology was used in the design and fabrication of the high-temperature optocoupler package. The optimal coupling behaviors, driving capabilities and response speed of the optocouplers were concentrated and investigated in this paper. Emitters and detectors with different emission and spectral wavelengths were studied to achieve optimal coupling behaviors. Relatively high coupling efficiency is achieved with emitters and detectors of emission and spectral wavelength in the red spectrum (i.e., 620–750 nm), leading to higher current transfer ratios (CTR). To further enhance the electrical performance, optocouplers with multiple …

Transitioning To Sustainable Healthy Diets: A Model-Based And Conceptual System Thinking Approach To Optimized Sustainable Diet Concepts In The United States, Prince Agyemang, Ebenezer M. Kwofie, Jamie Baum

Biological and Agricultural Engineering Faculty Publications and Presentations

Food production and consumption are essential in human existence, yet they are implicated in the high occurrences of preventable chronic diseases and environmental degradation. Although healthy food may not necessarily be sustainable and vice versa, there is an opportunity to make our food both healthy and sustainable. Attempts have been made to conceptualize how sustainable healthy food may be produced and consumed; however, available data suggest a rise in the prevalence of health-related and negative environmental consequences of our food supply. Thus, the transition from conceptual frameworks to implementing these concepts has not always been effective. This paper explores the …

Cross-Issue Correlation Based Opinion Prediction In Cyber Argumentation, Md Mahfuzer Rahman, Xiaoqing "Frank" Liu, Joseph W. Sirrianni, Douglas J. Adams

Computer Science and Computer Engineering Faculty Publications and Presentations

One of the challenging problems in large scale cyber-argumentation platforms is that users often engage and focus only on a few issues and leave other issues under-discussed and under-acknowledged. This kind of non-uniform participation obstructs the argumentation analysis models to retrieve collective intelligence from the underlying discussion. To resolve this problem, we developed an innovative opinion prediction model for a multi-issue cyber-argumentation environment. Our model predicts users’ opinions on the non-participated issues from similar users’ opinions on related issues using intelligent argumentation techniques and a collaborative filtering method. Based on our detailed experimental results on an empirical dataset collected using …

Novel Neurostimulation-Based Haptic Feedback Platform For Grasp Interactions With Virtual Objects, Aliyah K. Shell, Andres E. Pena, James J. Abbas, Ranu Jung

Biomedical Engineering Faculty Publications and Presentations

Haptic perception is a vital part of the human experience that enriches our engagement with the world, but the ability to provide haptic information in virtual reality (VR) environments is limited. Neurostimulation-based sensory feedback has the potential to enhance the immersive experience within VR environments by supplying relevant and intuitive haptic feedback related to interactions with virtual objects. Such feedback may contribute to an increase in the sense of presence and realism in VR and may contribute to the improvement of virtual reality simulations for future VR applications. This work developed and evaluated xTouch, a neuro-haptic platform that extends the …

Functional Analysis Of The Cortical Transcriptome And Proteome Reveal Neurogenesis, Inflammation, And Cell Death After Repeated Traumatic Brain Injury In Vivo, Celeste Dunn, Lais A. Ferreira, Sara M. Venier, Syed F. Ali, Jeffery Wolchok, Kartik Balachandran

Biomedical Engineering Faculty Publications and Presentations

The pathological effects of repeated traumatic brain injuries (TBIs) are largely unknown. To gain a detailed understanding of the cortical tissue acute biological response after one or two TBIs, we utilized RNA-sequencing and protein mass spectrometry techniques. Using our previously validated C57Bl/6 weight-drop model, we administered one or two TBIs of a mild or moderate severity. Double injury conditions were spaced 7 days apart, and cortical tissue was isolated 24 h after final injury. Analysis was carried out through functional gene annotation, utilizing Gene Ontology, for both the proteome and transcriptome. Major themes across the four different conditions include: neurogenesis; …

Dietary Practices During Pregnancy In A Marshallese Community: A Mixed Methods Analysis, Britni Ayers, Cari A. Bogulski, Ashlea Bennett-Milburn, Anna Fisher, Morda Newton, Pearl A. Mcelfish

Industrial Engineering Faculty Publications and Presentations

Dietary practices during pregnancy play a pivotal role in the health of women and their children and set the foundation for long-term health. Marshallese women have disproportionally higher rates of maternal and infant health disparities, yet little is known about the dietary practices during their pregnancy. The purpose of this study was to identify dietary practices during pregnancy among Marshallese women. From March 2019 to March 2020, a purposive sample of 33 pregnant Marshallese participants participated in a mixed methods study. Two primary themes emerged: (1) traditional beliefs about a healthy diet during pregnancy; and (2) dietary change during pregnancy. …

Monitoring The M-Dwarf Host Stars Of Tess Exoplanet Candidates: Stellar Flares And Habitability, Ashley Lieber

Physics Undergraduate Honors Theses

In the search for life beyond our solar system, the study of M-dwarfs has become increasingly important due to their unique characteristics including their small size, flaring capabilities, and long lifespans. Their small size allows for exoplanet detection due to observable gravitational interactions, and the stellar flares could potentially trigger prebiotic life on exoplanets in the system. Lastly, their long lifespans may provide the conditions necessary to foster prebiotic life and the development of more complex organisms over time. Flare rate is a critical factor in determining the habitability of the exoplanet due to its potential to damage or incubate …

Design Of A Freight Transportation Outreach Curriculum, Breanna Stoesz

Civil Engineering Undergraduate Honors Theses

This project is centered around finding a solution to the shortage of truck drivers within the freight industry. Specifically, this project aims to lessen this shortage by ensuring potential future drivers are aware of the benefits of the industry and are encouraged to consider this career path for themselves. By producing an engaging and educational freight transportation curriculum for middle and high school students to go through in outreach programs, these students would have an increased likelihood of joining the trucking profession and encourage others to become informed about the profession as well. In addition to the direct driving role, …

Gender Perceptions And Female Students' Academic Engagement And Success In Stem Fields, Rheanna Morgan

School of Social Work Undergraduate Honors Theses

Despite an increase of females in higher education and the workforce, fields such as science, technology, engineering, and mathematics (STEM) continue to be male-dominated. One explanation for this trend is the lack of gender representation and counterstereotypical role models to encourage female engagement in these fields at the university level. Previous research has looked at instructor gender, classroom gender composition, and involvement in extracurricular activities as possible factors influencing students' engagement and success in the classroom. However, few studies have investigated how gender perceptions influence female students in STEM fields. This study uses self-report data from a voluntary survey to …

Measuring The Electrical Properties Of 3d Printed Plastics In The W-Band, Noah Gregory

Electrical Engineering Undergraduate Honors Theses

3D printers are a method of additive manufacturing that consists of layering material to produce a 3D structure. There are many types of 3D printers as well as many types of materials that are capable of being printed with. The most cost-effective and well documented method of 3D printing is called Fused Deposition Modeling (FDM). FDM printers work by feeding a thin strand of plastic filament through a heated extruder nozzle. This plastic is then deposited on a flat, typically heated, surface called a print bed. The part is then built by depositing thin layers of plastic in the shape …

Design Of A Bandgap Voltage Reference, Nicolaus Vail

Electrical Engineering Undergraduate Honors Theses

This thesis details the design process of a bandgap voltage reference (BGR) integrated circuit in a 180 nm CMOS process. A BGR provides a constant DC voltage across a range of operating temperatures and supply voltages. By its nature, the circuit is intended as a reference, not to provide current, so the output would be connected to a very high impedance, such as the gate of a transistor. At 27°C, this design provides a 955 mV reference voltage given a nominal VDD of 3 V. From 20°C to 175°C, the output voltage has a variance of 7.2 mV (approximately 0.8%) …

Signal Analysis Of Photovoltaic Systems For Multilevel Cybersecurity, Wesley G. Schwartz

Electrical Engineering Undergraduate Honors Theses

The cybersecurity of grid-connected power electronics is a rapidly developing field as more and more of these devices become a part of the Internet of Things. The objective of this thesis to analyze the current control signals of a photovoltaic (PV) inverter and develop an interface board for the implementation of a new cyber-secure controller.

In this thesis, the testing and in-depth analysis of the current PV inverter control system will be conducted. Using the data collected, an interface board will be developed to allow the use of the Unified Control Board (UCB), developed by Chris Farnell, in the PV …

The Effect Of Changing Land Use On Streamflow Statistics And Flood Flows Across Select Gages In Northwest Arkansas, Timothy Mcmullen

Civil Engineering Undergraduate Honors Theses

Since 1901, heavy rainfall events have increased in the United States in both intensity and frequency, and population in the United States has increased, resulting in significant land use changes. Both of these trends could explain an increase in observed flood magnitude and frequency. In order to determine if a relationship exists between land use/land cover and changing stream flows in northwest Arkansas, this study analyzed temporal changes in various flow statistics for fourteen stream gages and compared the rates of change in flow statistics from gages on streams with watersheds that have varying land uses, i.e. urban, agricultural, and …

How Blockchain Solutions Enable Better Decision Making Through Blockchain Analytics, Sammy Ter Haar

Information Systems Undergraduate Honors Theses

Since the founding of computers, data scientists have been able to engineer devices that increase individuals’ opportunities to communicate with each other. In the 1990s, the internet took over with many people not understanding its utility. Flash forward 30 years, and we cannot live without our connection to the internet. The internet of information is what we called early adopters with individuals posting blogs for others to read, this was known as Web 1.0. As we progress, platforms became social allowing individuals in different areas to communicate and engage with each other, this was known as Web 2.0. As Dr. …

Sustainability In Construction Practices As Emphasis On Environmental Investing In Esg Model Grows, Maddie Heal

Management Undergraduate Honors Theses

The purpose of this research is to emphasize the importance of growing investment on environmental initiatives in business ESG models in regard to sustainable practices in construction. The ESG acronym is known as the environmental, social, and governance efforts that businesses strive to incorporate in their models to increase the responsibility of operations.

Investors continue to seek out responsible businesses when choosing which ventures to pursue. The analysis of the current construction crisis, current investments in the right direction of Eco-friendly design regarding construction, and the threats and benefits incentivizing those investments elucidates the need to emphasize socially responsible investment …

A Versatile Python Package For Simulating Dna Nanostructures With Oxdna, Kira Threlfall

Computer Science and Computer Engineering Undergraduate Honors Theses

The ability to synthesize custom DNA molecules has led to the feasibility of DNA nanotechnology. Synthesis is time-consuming and expensive, so simulations of proposed DNA designs are necessary. Open-source simulators, such as oxDNA, are available but often difficult to configure and interface with. Packages such as oxdna-tile-binding pro- vide an interface for oxDNA which allows for the ability to create scripts that automate the configuration process. This project works to improve the scripts in oxdna-tile-binding to improve integration with job scheduling systems commonly used in high-performance computing environments, improve ease-of-use and consistency within the scripts compos- ing oxdna-tile-binding, and move …

Analysis Of Gpu Memory Vulnerabilities, Jarrett Hoover

Computer Science and Computer Engineering Undergraduate Honors Theses

Graphics processing units (GPUs) have become a widely used technology for various purposes. While their intended use is accelerating graphics rendering, their parallel computing capabilities have expanded their use into other areas. They are used in computer gaming, deep learning for artificial intelligence and mining cryptocurrencies. Their rise in popularity led to research involving several security aspects, including this paper’s focus, memory vulnerabilities. Research documented many vulnerabilities, including GPUs not implementing address space layout randomization, not zeroing out memory after deallocation, and not initializing newly allocated memory. These vulnerabilities can lead to a victim’s sensitive data being leaked to an …

Side-Channel Analysis On Post-Quantum Cryptography Algorithms, Tristen Teague

Computer Science and Computer Engineering Undergraduate Honors Theses

The advancements of quantum computers brings us closer to the threat of our current asymmetric cryptography algorithms being broken by Shor's Algorithm. NIST proposed a standardization effort in creating a new class of asymmetric cryptography named Post-Quantum Cryptography (PQC). These new algorithms will be resistant against both classical computers and sufficiently powerful quantum computers. Although the new algorithms seem mathematically secure, they can possibly be broken by a class of attacks known as side-channels attacks (SCA). Side-channel attacks involve exploiting the hardware that the algorithm runs on to figure out secret values that could break the security of the system. …

A Study Of Software Development Methodologies, Kendra Risener

Computer Science and Computer Engineering Undergraduate Honors Theses

Software development methodologies are often overlooked by software engineers as aspects of development that are handled by project managers alone. However, if every member of the team better understood the development methodology being used, it increases the likelihood that the method is properly implemented and ultimately used to complete the project more efficiently. Thus, this paper seeks to explore six common methodologies: the Waterfall Model, the Spiral Model, Agile, Scrum, Kanban, and Extreme Programming. These are discussed in two main sections in the paper. In the first section, the frameworks are isolated and viewed by themselves. The histories, unique features, …

Comparative Study Of Snort 3 And Suricata Intrusion Detection Systems, Cole Hoover

Computer Science and Computer Engineering Undergraduate Honors Theses

Network Intrusion Detection Systems (NIDS) are one layer of defense that can be used to protect a network from cyber-attacks. They monitor a network for any malicious activity and send alerts if suspicious traffic is detected. Two of the most common open-source NIDS are Snort and Suricata. Snort was first released in 1999 and became the industry standard. The one major drawback of Snort has been its single-threaded architecture. Because of this, Suricata was released in 2009 and uses a multithreaded architecture. Snort released Snort 3 last year with major improvements from earlier versions, including implementing a new multithreaded architecture …

Using Bluetooth Low Energy And E-Ink Displays For Inventory Tracking, David Whelan

Computer Science and Computer Engineering Undergraduate Honors Theses

The combination of Bluetooth Low energy and E-Ink displays allow for a low energy wire-less display. The application of this technology is far reaching especially given how the Bluetooth Low Energy specification can be extended. This paper proposes an extension to this specification specifically for inventory tracking. This extension combined with the low energy E-Ink display results in a smart label that can keep track of additional meta data and inventory counts for physical inventory. This label helps track the physical inventory and can help mitigate any errors in the logical organization of inventory.

Determining Earthquake Impacts On Arkansas' Roadway Network: An Application Of Hazus., Simon Rothwell

Civil Engineering Undergraduate Honors Theses

Natural hazards are a dangerous and unpredictable aspect of life on earth. They can cause devastating damage to our surroundings that makes movement of people, goods, and emergency services difficult. There is a need to plan for these disasters to ensure that damages to our infrastructure and people are minimized. It can be difficult for planners to determine which parts of a roadway network are most vulnerable to a specific disaster and what their impact on the rest of the network may be. This thesis uses a nationally available natural disaster estimation tool developed by FEMA called “Hazus” (FEMA, 2020). …

Surface Laser Texturing Of Cocrmo Alloys, Gabriel Dharwadker

Biomedical Engineering Undergraduate Honors Theses

Artificial orthopedic implants such as hip joints suffer from excessive wear due to excess friction between the polyethylene and cobalt-chromium-molybdenum surfaces of the device. This increase in friction causes a fraction of them to give out within ten years. Therefore, to minimize the probability of this happening, recent research has been conducted regarding laser surface texturing of the cobalt-chromium-molybdenum alloy components of artificial joints. These surface textures serve to mimic the native lubrication mechanisms of cartilage in natural joints, which, in a natural joint, lowers the friction. However, the production of these laser surface textures is still a field of …