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2019

Theses/Dissertations

University of Arkansas, Fayetteville

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Articles 1 - 30 of 82

Full-Text Articles in Engineering

Load Flow Analysis Of 138/69kv Substation Using Electrical Transient & Analysis Program (Etap), Vanessa Abadia Gomez Dec 2019

Load Flow Analysis Of 138/69kv Substation Using Electrical Transient & Analysis Program (Etap), Vanessa Abadia Gomez

Electrical Engineering Undergraduate Honors Theses

This paper examines the load flow analysis of a high-voltage substation using ETAP, and explores options for improving the voltage profile of the system. This study yields critical information about the system, such as the voltage drop at each feeder, the voltage at each bus, as well as real and reactive power losses at the different branches and feeders. In this power flow examination, the system’s performance is evaluated for different operating conditions, so that control measurements can be applied if necessary. The experimental results are used for proposing a plan of using fixed and switched shunt capacitor banks ...


Investigation Of The Effect Of Age On Regenerative Outcomes Following Treatment Of Volumetric Muscle Loss Injuries, John Taehwan Kim Aug 2019

Investigation Of The Effect Of Age On Regenerative Outcomes Following Treatment Of Volumetric Muscle Loss Injuries, John Taehwan Kim

Theses and Dissertations

Volumetric muscle loss (VML) is a traumatic injury in skeletal muscle resulting in the bulk loss of more than 20% of the muscle’s volume. Included in the bulk loss of muscle is the skeletal muscle niche comprised of nerve bundles, vasculature, local progenitor cells, basal lamina, and muscle fibers, overwhelming innate repair mechanisms. The hallmark of VML injury is the excessive accumulation of non-contractile, fibrotic tissue and permanent functional deficits. Though predominant in the younger demographic, the elderly population is also captured within VML injuries. There are many factors that change with aging in skeletal muscle that may further ...


Generation Of A Ccl2 Knockout Using Crispr/Cas9 And Lipid Mediated Transfection In Ct-26 Murine Colon Carcinoma Cells, Emma Sullivan Aug 2019

Generation Of A Ccl2 Knockout Using Crispr/Cas9 And Lipid Mediated Transfection In Ct-26 Murine Colon Carcinoma Cells, Emma Sullivan

Biomedical Engineering Undergraduate Honors Theses

CCL2 is an inflammatory mediator that is released by tumor cells to activate and direct immune cell species, especially macrophages, to inflammatory sites within the body. The goal of this project was to successfully generate knockout the CCL2 ligand gene using a CRISPR/Cas9 complex delivered via lipid mediated transfection. The sgRNA and Cas9 mRNA were introduced into the cells via lipid-mediated transfection. The cells were incubated for 4 days, before being analyzed using PCR and gel electrophoresis. We expected to see one band on the first gel and two bands on the second gel. Two bands appeared on the ...


Displacement Derived Energy Levels For Harvard Miniature Compaction, Ana Laura Errigo, Julia Loshelder Aug 2019

Displacement Derived Energy Levels For Harvard Miniature Compaction, Ana Laura Errigo, Julia Loshelder

Civil Engineering Undergraduate Honors Theses

Previously, the amount of energy provided by the Harvard Miniature tamper was adjusted by changing the number of blows per lift or the number of lifts or was not adjusted at all. However, this research was conducted to investigate the effect of adjusting the displacement of the spring (increased or decreased) to change the potential energy of the spring and therefore change the compacive effort with a specific type of soil. Thus, the objective was to match the compaction energies using the Harvard miniature method with the compaction energies obtained using the Proctor method. Specifically, the goal was to show ...


Development Of A Ground-Based Aerial-Tracking Instrument For Open-Path Spectroscopy To Monitor Atmospheric Constituents, Haden Hodges Aug 2019

Development Of A Ground-Based Aerial-Tracking Instrument For Open-Path Spectroscopy To Monitor Atmospheric Constituents, Haden Hodges

Civil Engineering Undergraduate Honors Theses

A ground-based aerial-tracking instrument, known as the Ground Tracker, designed to provide spectral data to quantify greenhouse gases is under development. The Ground Tracker includes an Optical System including a high power rifle scope, video camera, and spectrometer used to locate an active light source from the Emitter, and collect spectral data by utilizing an actuating mirror. The implementation of this instrument could be made low cost by utilizing existing weather balloon infrastructure to allow the Emitter to be placed into the lower stratosphere. The recovery of the emitter will be possible by tracking the GPS coordinates. Weather balloon instrument ...


Bioengineering Extracellular Matrix Scaffolds For Volumetric Muscle Loss, Kevin Roberts Aug 2019

Bioengineering Extracellular Matrix Scaffolds For Volumetric Muscle Loss, Kevin Roberts

Theses and Dissertations

Volumetric muscle loss overwhelms skeletal muscle’s ordinarily capable regenerative machinery, resulting in fibrosis and severe functional deficits which have defied clinical repair strategies. My work spans the design and preclinical evaluation of implants intended to drive the cell community of injured muscle toward a regenerative state, as well as the development of an understanding of the molecular responses of this cell community to biomaterial interventions. I demonstrate a new class of biomaterial by leveraging the productive capacity of sacrificial hollow fiber membrane cell culture; I show specifically that unique threads of whole extracellular matrix can be isolated by solvent ...


Five-Level Flying Capacitor Converter Used As A Static Compensator For Current Unbalances In Three-Phase Distribution Systems, Rafael Franceschi Aug 2019

Five-Level Flying Capacitor Converter Used As A Static Compensator For Current Unbalances In Three-Phase Distribution Systems, Rafael Franceschi

Theses and Dissertations

This thesis presents and evaluates a solution for unbalanced current loading in three-phase distribution systems. The proposed solution uses the flying capacitor multilevel converter as its main topology for an application known as Unbalanced Current Static Compensator. The fundamental theory, controller design and prototype construction will be presented along with the experimental results. The Unbalanced Current Static Compensator main objective is the balancing of the up-stream currents from the installation point to eliminate the negative- and zero-sequence currents originated by unbalanced single-phase loads.

Three separate single-phase flying capacitor converters are controlled independently using a d-q rotating reference frame algorithm to ...


Plasmonic Properties Of Nanoparticle And Two Dimensional Material Integrated Structure, Desalegn Tadesse Debu May 2019

Plasmonic Properties Of Nanoparticle And Two Dimensional Material Integrated Structure, Desalegn Tadesse Debu

Theses and Dissertations

Recently, various groups have demonstrated nano-scale engineering of nanostructures for optical to infrared wavelength plasmonic applications. Most fabrication technique processes, especially those using noble metals, requires an adhesion layer. Previously proposed theoretical work to support experimental measurement often neglect the effect of the adhesion layers. The first finding of this work focuses on the impact of the adhesion layer on nanoparticle plasmonic properties. Gold nanodisks with a titanium adhesion layer are investigated by calculating the scattering, absorption, and extinction cross-section with numerical simulations using a finite difference time domain (FDTD) method. I demonstrate that a gold nanodisk with an adhesive ...


Using Peripheral Venous Pressure Waveforms To Predict Key Hemodynamic Parameters, Ali Zohair A Alalawi May 2019

Using Peripheral Venous Pressure Waveforms To Predict Key Hemodynamic Parameters, Ali Zohair A Alalawi

Theses and Dissertations

Analysis of peripheral venous pressure (PVP) waveforms is a novel method of monitoring intravascular volume. Two cohorts were used to study the hemodynamics change of the body state and its influence on the PVP using (1) dehydration setting with infants suffering from pyloric stenosis and (2) hemorrhage setting during a craniosynostosis elective surgery. The goal of this research is to develop a minimally invasive method of analyzing the PVP waveforms and find correlations with volume loss.

Twenty-three pyloric stenosis patients PVP were acquired at five stages and were divided into euvolemic, normal fluid volume, and hypovolemic, significant fluid loss. Seven ...


Investigating Virus Clearance Via Ph Inactivation During Biomanufacturing, Wenbo Xu May 2019

Investigating Virus Clearance Via Ph Inactivation During Biomanufacturing, Wenbo Xu

Biomedical Engineering Undergraduate Honors Theses

In the processing of biopharmaceuticals, viral clearance and viral safety are important for the development of monoclonal antibodies. Murine xenotropic leukemia virus (XMuLV) is one of the retroviruses, recommended by Food and Drug Administration (FDA) as a model virus for viral clearance via inactivation from therapeutics derived from Chinese hamster ovary cells (CHO). A robust and effective method was investigated to clear or inactivate endogenous viruses by low pH inactivation. The effects of different conductivity and inactivated time on XMuLV clearance was determined. Acetate buffer was prepared with different conductivity, and 2% XMuLV was spiked into acetate buffer. XMuLV virus ...


Autonomous Boat Control Software Design Using Model-Based Systems Engineering, Noah Nelson May 2019

Autonomous Boat Control Software Design Using Model-Based Systems Engineering, Noah Nelson

Electrical Engineering Undergraduate Honors Theses

While there is considerable buzz about self-driving cars, self-driving boats are actually more fully developed. The Boat Hardware Control Platform Team was tasked with developing a fleet of small autonomous boats that travel to a destination while avoiding obstacles and staying in formation. The author’s specific task was to develop software used by the boats to detect obstacles and plan a route to a destination. This was done using a method inspired by self-driving cars, which shows promise, but is still being tested at the time of writing. The entire project incorporated model-based systems engineering, which proved to be ...


Design Of Two-Stage Operational Amplifier Using Indirect Feedback Frequency Compensation, Roderick Gomez May 2019

Design Of Two-Stage Operational Amplifier Using Indirect Feedback Frequency Compensation, Roderick Gomez

Electrical Engineering Undergraduate Honors Theses

This thesis work details the designing process of two silicon two-stage operational amplifiers with indirect feedback compensation and with Miller compensation technique. The main objective of this thesis is to study the advantages of indirect feedback compensation in comparison with Miller compensation and how this technique can be applied to meet certain design specifications. The operational amplifiers are designed with 130 nm Silicon Germanium CMOS process ideally for temperature range of 25°C to 300°C. The two op-amps are designed to have a DC gain of about 70 dB and 60 degrees of phase margin. The indirect feedback compensation ...


Recovery Of Water And Salt From Hyper-Saline Mine Water Using Freeze Crystallization, Clara Somerville May 2019

Recovery Of Water And Salt From Hyper-Saline Mine Water Using Freeze Crystallization, Clara Somerville

Chemical Engineering Undergraduate Honors Theses

The Freezerbacks researched, designed, and economically evaluated a full-scale freeze crystallization process as well as two alternative full-scale processes: 5 stage multiple effect evaporation and reverse osmosis. All three processes were designed to treat hyper-saline mine water that was sent into evaporation pond systems. These systems were designed for Freeport-McMoRan’s mines that need to treat impacted water.

The Freeport-McMoRan copper mine in Miami, Arizona was visited in order to gain insight about the problem. The mine is no longer actively mining copper and is in the process of reclaiming land used. An essential part of restoring the land is ...


Desalination: Freeze Crystallization, Ibrahim Guiga May 2019

Desalination: Freeze Crystallization, Ibrahim Guiga

Chemical Engineering Undergraduate Honors Theses

The Freezerbacks researched, designed, and economically evaluated a full-scale freeze crystallization process as well as two alternative full-scale processes: 5 stage multiple effect evaporation and reverse osmosis. All three processes were designed to treat hyper-saline mine water that was sent into evaporation pond systems. These systems were designed for Freeport-McMoRan’s mines that need to treat impacted water.

The Freeport-McMoRan copper mine in Miami, Arizona was visited in order to gain insight about the problem. The mine is no longer actively mining copper and is in the process of reclaiming land used. An essential part of restoring the land is ...


Removal And Reuse Of Phosphorus As A Fertilizer From Cafo Runoff, Kristin Moore May 2019

Removal And Reuse Of Phosphorus As A Fertilizer From Cafo Runoff, Kristin Moore

Chemical Engineering Undergraduate Honors Theses

Eutrophication is the process in which nutrient saturated waters promote algal blooms on the surface of the water. This limits the amount of dissolved oxygen content in the water, effectively limiting the range of species that can survive in a body of water. Concentrated animal feeding operations (CAFO) can contribute to this issue. The animals in a CAFO produce large amounts of nutrient-rich waste streams that can enter natural waterways if not properly managed and increase the problem of eutrophication. The ability to treat these waste streams and recover the excess nutrients would allow for not only the reduction of ...


Task 1: Silver-Based Microbial Check Valve For Spacecraft Potable Water Systems, Eric Beitle May 2019

Task 1: Silver-Based Microbial Check Valve For Spacecraft Potable Water Systems, Eric Beitle

Chemical Engineering Undergraduate Honors Theses

As human space exploration increases, the development of a more efficient potable water treatment system suited for spacecraft becomes crucial. This Waste-management Education Research Consortium (WERC) challenge was designed to explore the viability of microbial control through the utilization of silver ions as a biocide for possible integration into the Tranquility Node 3 water purification system aboard the International Space Station (ISS). Current systems using iodine risk causing hyperthyroidism from overexposure; however, silver can be safely ingested without this side effect. After researching silver delivery methods including electrochemical ion production, controlled release, or a combination of the two, our team ...


Effect Of Thiols For Nitrogen Reduction To Ammonia, Zakary R. Ford May 2019

Effect Of Thiols For Nitrogen Reduction To Ammonia, Zakary R. Ford

Chemical Engineering Undergraduate Honors Theses

Ammonia is an important chemical used for fertilizers and also a potential carbon-free hydrogen storage medium. The Haber-Bosch process is the main production process, which requires large energy- and capital-input. Therefore, it is crucial to develop an alternate scalable synthesis that provides a less energy intensive and more economical route for synthetic ammonia production. In this paper, a 1Fe1Ni film was functionalized with C3OH and C6OH for the electrochemical synthesis of ammonia. This work will provide some insight into how thiol ligands can increase the selectivity of the catalyst for nitrogen reduction reaction and can be ...


Recovery Of Water And Salt From Hyper-Saline Mine Water Using Freeze Crystallization, Patsy Ann Dawson May 2019

Recovery Of Water And Salt From Hyper-Saline Mine Water Using Freeze Crystallization, Patsy Ann Dawson

Chemical Engineering Undergraduate Honors Theses

The Freezerbacks researched, designed, and economically evaluated a full-scale freeze crystallization process as well as two alternative full-scale processes: 5 stage multiple effect evaporation and reverse osmosis. All three processes were designed to treat hyper-saline mine water that was sent into evaporation pond systems. These systems were designed for Freeport- McMoRan’s mines that need to treat impacted water.

The Freeport-McMoRan copper mine in Miami, Arizona was visited in order to gain insight about the problem. The mine is no longer actively mining copper and is in the process of reclaiming land used. An essential part of restoring the land ...


Scale Model And Flow Visualization Of Jack Rabbit Ii Chlorine Field Test, Charlotte Williams May 2019

Scale Model And Flow Visualization Of Jack Rabbit Ii Chlorine Field Test, Charlotte Williams

Chemical Engineering Undergraduate Honors Theses

The release of hazardous gases, especially accidental releases, can have a major impact on the surrounding environment and population. The history of accidental hazardous gas releases is filled with plant destruction, civilian injury, and even death. Knowledge of how these gases travel and disperse once released can significantly lessen physical harm and improve emergency procedures. The Jack Rabbit II field test was conducted in pursuit of this knowledge for a chlorine release. In this field test, a purpose-built chlorine tank was surrounded by CONEX trailers assembled in the desert in Utah to model an urban setting. Multiple releases of chlorine ...


Investigation Of Acute Radiation-Induced Changes In Oxygenation In A Murine Breast Tumor Model, Alaa Abdelgawad May 2019

Investigation Of Acute Radiation-Induced Changes In Oxygenation In A Murine Breast Tumor Model, Alaa Abdelgawad

Biomedical Engineering Undergraduate Honors Theses

Around 50-60% of all cancer patients undergo radiation therapy. Although some patients show complete response with no recurrence, a significant proportion of the population still develop radiation resistance. It is important to identify tumor resistance at early stages of therapy in order to adjust treatment protocol and avoid extra exposure to radiation. Current methods to assess treatment response are only limited to anatomical measurements of tumor volume after therapy. Novel approaches that shed the light on any functional information during the course of radiotherapy could significantly improve our ability to identify patients who do not respond to radiation therapy. Diffuse ...


Lighting And Economic Considerations For A Hydroponic S-Based Greenhouse At Tri Cycle Farms, Laura Gray May 2019

Lighting And Economic Considerations For A Hydroponic S-Based Greenhouse At Tri Cycle Farms, Laura Gray

Biological and Agricultural Engineering Undergraduate Honors Theses

Hydroponics is an agricultural technology that involves growing plants without soil, instead using other growth media with added nutrients, typically inside a controlled facility such as a greenhouse. Hydroponics-based agriculture has a number of benefits, namely that it is more water efficient, requires less intensive labor, yields higher quality crops consistently in shorter time, and is easier to control. It also has the potential to be economically advantageous, due to its ability to grow certain crops in the off-season. In Fayetteville, Arkansas, a non-profit urban farm known as Tri Cycle Farms has been seeking a way to design, build, and ...


Design Of An Embedded Iris Recognition System For Use With A Multi-Factor Authentication System., Christopher David Hess May 2019

Design Of An Embedded Iris Recognition System For Use With A Multi-Factor Authentication System., Christopher David Hess

Electrical Engineering Undergraduate Honors Theses

This paper describes in detail the design, manufacturing and testing of an embedded iris scanner for use with a multifactor authentication system. The design process for this project included hardware design from part selection to board design to populating. Additionally, this process included the entirety of the software development, though the iris recognition process was largely based on other works. The functional requirements for the overall multi-factor authentication system were to have three authentication methods with a thirty second window to complete all three. The system acceptance accuracy was required to be greater than 75%. Those requirements therefore dictate that ...


Modeling Solder Ball Array Interconnects For Power Module Optimization, Paul Swearingen May 2019

Modeling Solder Ball Array Interconnects For Power Module Optimization, Paul Swearingen

Electrical Engineering Undergraduate Honors Theses

PowerSynth is a software platform that can co-optimize power modules utilizing a 2D topology and wire bond interconnects. The novel 3D architectures being proposed at the University of Arkansas utilize solder ball interconnects instead of wire bonds. Therefore, they currently cannot be optimized using PowerSynth. This paper examines methods to accurately model the parasitic inductance of solder balls and ball grid arrays so they may be implemented into software for optimization. Proposed mathematical models are validated against ANSYS Electromagnetics Suite simulations. A comparison of the simulated data shows that mathematical models are well suited for implementation into optimization software platforms ...


Design Of Remote Datalogger Connection And Live Data Tweeting System, Zachary Wofford May 2019

Design Of Remote Datalogger Connection And Live Data Tweeting System, Zachary Wofford

Biological and Agricultural Engineering Undergraduate Honors Theses

Low-Impact Development (LID) is an attempt to sustainably respond to the potential hazards posed by urban expansion. Green roofs are an example of LID design meant to reduce the amount of runoff from storm events that are becoming more intense and less predictable while also providing insulation to buildings. LID has not yet been widely adopted as it is often a more expensive alternative to conventional infrastructure (Bowman et. al., 2009). However, its benefits are apparent. The University of Arkansas Honors College awarded a grant to research the large green roof atop Hillside Auditorium. One part of this grant is ...


Simulating Delayed Flood And Alternate Wetting And Drying Rice Production In Arkansas Using Apex, Jaden Tatum May 2019

Simulating Delayed Flood And Alternate Wetting And Drying Rice Production In Arkansas Using Apex, Jaden Tatum

Biological and Agricultural Engineering Undergraduate Honors Theses

Rice is a staple food for billions of people, and rice production will need to grow with global populations. One potential solution to decrease the environmental impacts associated with rice production is alternate wetting and drying (AWD) management which, as opposed to sustained flooding, allows a reduction of water use and methane emissions. Studies into AWD have shown that yield levels may be conserved when using this practice, which would be necessary for widespread implementation. Modeling AWD management changes successfully would help to determine where and to what extent this practice may be effective in the US. The management and ...


Quantifying Litter Decomposition Rates On A Semi-Intensive Green Roof, Eli Lasalle May 2019

Quantifying Litter Decomposition Rates On A Semi-Intensive Green Roof, Eli Lasalle

Biological and Agricultural Engineering Undergraduate Honors Theses

The overall goal of this study was to provide a measure of the decomposition rate constant on a semi- intensive green roof located in Fayetteville, Arkansas. The specific approach chosen was the use of the Tea Bag Index (TBI), a standardized plant litter decomposition test. There was some heterogeneity observed on site and the locations of samples tested were chosen based on this. Additional laboratory tests were conducted in order to determine whether there would be a large impact of temperature on decomposition or if it would be outweighed by other factors. The temperatures compared were 5°C, 20°C ...


Challenges And Opportunities Of Layered Cathodes Of Linixmnyco(1-X-Y)O2 For High-Performance Lithium-Ion Batteries, Jason Frank May 2019

Challenges And Opportunities Of Layered Cathodes Of Linixmnyco(1-X-Y)O2 For High-Performance Lithium-Ion Batteries, Jason Frank

Mechanical Engineering Undergraduate Honors Theses

High energy density lithium-ion batteries (LIBs) are widely demanded for portable electronic devices and electrical vehicles. Layered-structure LiCoO2 oxide (LCO) has been the most commonly used cathode material in commercial LIBs. Compared to LCO, LiNi1-x-yMnxCoyO2 (NMC) cathodes are particularly attractive due to their reduced cost and higher capacity. Among the NMC cathodes, nickel-containing LiNi0.5Co0.3Mn0.2O2 (NMC532) is one of the most promising cathode materials undergoing intensive investigation, but suffers from a series of technical issues, such as structural instability, performance fading, and safety ...


Design And Cost Analysis Of Acrylic Acid Plant, Adam Ferrier May 2019

Design And Cost Analysis Of Acrylic Acid Plant, Adam Ferrier

Chemical Engineering Undergraduate Honors Theses

The purpose of this project was to model and design a plant to produce 75,000 tons per year of acrylic acid. Using the design in section B.9 of Richard Turton’s Analysis, Synthesis, and Design of Chemical Processes as a starting point, a plant was designed based around the partial oxidation of propylene to acrylic acid. The final plant design produces about 86,000 tons per year of acrylic acid. Using an interest rate of 10%, the plant has a discounted cash flow rate of return of 32% over 2 years of startup and 10 years of operation ...


Rating Curve Development For The Upper James Fork, Lower James Fork And Hinkle Jones Creek In The Upper Poteau River Watershed In Arkansas, Meagan O'Hare May 2019

Rating Curve Development For The Upper James Fork, Lower James Fork And Hinkle Jones Creek In The Upper Poteau River Watershed In Arkansas, Meagan O'Hare

Biological and Agricultural Engineering Undergraduate Honors Theses

Stream discharge is necessary to estimate loads and calibrate and validate watershed models. Access to long-term water quality data and discharge measurements allows for modeling of water quality changes across a watershed over time. However, discharge monitoring stations are often expensive to install and maintain, particularly in small rivers. A more cost-effective method for monitoring streamflow has been implemented in the Upper Poteau River Watershed (UPRW) in Arkansas. This method consists of an SonTek acoustic doppler instrument for measuring storm stream flow, with is combined with manual baseflow discharge measurements. The combined stormflow and baseflow measurements are combined with a ...


Ecological Co2 Flux Of A Green Roof Ecosystem And A Typical Grassland Ecosystem, Madeline Oxner May 2019

Ecological Co2 Flux Of A Green Roof Ecosystem And A Typical Grassland Ecosystem, Madeline Oxner

Biological and Agricultural Engineering Undergraduate Honors Theses

The Hillside Auditorium Green Roof is a low impact development feature on the University of Arkansas campus. It retains storm water and allows plants living on the roof to take up and transpire the water. Green roofs work to mimic natural ecosystems in urban environments. A key property is ecosystem respiration, which plays a large role in the global carbon cycle and is an important biologic activity indicator. The ecosystem respiration of Hillside Auditorium Green Roof was compared to a typical grassland ecosystem at the University of Arkansas farm to determine how closely the green roof is able to mimic ...