Engineering Commons^™

Using Computational Fluid Dynamics To Predict Flow Through The West Crack Breach Of The Great Salt Lake Railroad Causeway, Michael Rasmussen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Great Salt Lake in Utah, USA, is a terminal, saline lake and is divided into two primary sections (northern and southern) by an east-to-west railroad causeway. Shortly after completion of the earth-fill causeway in the late 1950s, the two sections became dramatically different with differences in water surface elevation and water density. These differences cause the formation of a unique flow behavior commonly referred to as a density-driven exchange flow or bi-directional flow; a behavior observed in other lake and ocean settings where two fluids of differing densities interact. Measuring these exchange flows is a priority for lake managers …

Bugs Buy Steady Releases From Hydropower Producers To Encourage More Synergistic Reservoir Management, Moazzam Ali Rind

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hydropower generated from dams has significant economic value, however, that value is achieved at the cost of native ecosystem devastation. Here, we have estimated loss in hydropower revenue due to inclusion of the steady low flow days –Bug Flow Experiments. We developed a linear optimization model and constraint method that restrict the number of steady low flow days while maximizes the hydropower revenue generation. The results suggested that increase in release volume will benefit both the objectives (win-win scenario), energy price differential between on-and off-peak periods controls the position and shape of tradeoff curves, and offset release does not have …

Highly Variable Rainfall-Runoff Patterns Across Burned Mountainous Watersheds In The Colorado River Headwaters, Haley Anne Canham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wildfires can contribute to enhanced flooding, erosion, debris flows, sediment transport, and water quality changes that impact downstream infrastructure, water users, and aquatic habitat. With increasing wildfire risk in the western U.S. due to a changing climate, understanding post-wildfire rainfall-runoff patterns and controls is critical for continued water resources security. To improve understanding of post-wildfire rainfall-runoff patterns and controls, we developed a transparent, repeatable analysis framework to collect precipitation and streamflow data, identify paired rainfall-runoff events, and analyze these events to evaluate post-wildfire rainfall-runoff patterns and controls. To automate the rainfall-runoff event identification, the Rainfall-Runoff Event Detection and Identification (RREDI) …

Fabrication And Testing Of Catalyst-Infused Filament For 3d Printing Of Ignition-Augmented Hybrid Rocket Fuels, Kurt C. Olsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis describes and addresses the need for reliable ignition in small satellite hybrid propulsion systems using higher density oxidizers. It describes methods of creating custom 3D printing ABS plastic based filaments that contain small amounts of catalysts. These catalysts lead to a more reliable and energy-efficient ignition of a hybrid rocked propulsion system using catalyst-infused ABS and nitrous oxide and oxygen blend called Nytrox, commonly known as ”laughing gas.” The ”laughing gas” has a higher density and can therefore provide more ”miles per gallon” in a hybrid propulsion system on a small satellite when compared to gaseous oxygen (GOX). …

Passage Probability Of Woody Debris Elements And Accumulations At I- And V-Shaped Rock Weirs, Kathryn Margetts

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The transport and accumulation of driftwood or large woody debris (LWD) in mountain streams is a natural part of catchment health and river connectivity. At hydraulic structures, the presence of LWD may impact flow efficiency and influence upstream water depth. LWD has been studied at a variety of spillways and weir types, however, little is known about its interaction at rock weirs. This study investigated factors affecting the passage of individual LWD elements and any LWD accumulations at rock weirs, as well as potential impacts upstream of LWD accumulations through field-informed scaled model testing. Observations of LWD at rock weirs …

Upstream Methods For Enhancing Engineered Curcumin Biosynthesis, Caleb D. Barton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Curcumin is a bright orange compound with myriad applications for human health and wellness. Curcumin occurs naturally in the plant Curcuma longa (commonly known as turmeric) but must be extracted from the roots in an environmentally unfriendly fashion to obtain commercially relevant amounts of the compound. In addition, extraction of curcumin from turmeric spice yields a mixture of various curcuminoids, presenting an issue for isolating it in its pure form and complicating its use in clinical settings.

Heterologous biosynthetic production of curcumin in Escherichia coli has been used extensively as a viable alternative to plant extraction but suffers from poor …

Multidisciplinary Reference Solutions For Performance-Optimized Aircraft Wings With Tailored Aerodynamic Load Distributions, Jeffrey D. Taylor

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Morphing wings, or wings that can change shape during flight, have the potential to substantially reduce the amount of fuel consumed by an aircraft over the course of its flight. However, the extent to which these wings can reduce fuel consumption depends on the design of the wing, including its aerodynamic efficiency and its structural layout, and how the aircraft flies, including its flight altitude and speed. Correctly predicting how these design and operational characteristics interact is critical to predicting how wing morphing may affect aircraft fuel consumption. Many computer prediction tools exist that include the effects of these interactions, …

Lentiviral Vector Production At High Cell Density By Transient Transfection Of Suspended Culture Hek Cells, Jacob G. Accordino

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Viral vectors are gene carriers that efficiently deliver therapeutic gene constructs to target cells. Viral vectors are frequently produced in suspension-growing cells of mammalian origin, referred to as packaging cells. Lentiviral vectors have become widely used as gene vectors since they were initially developed two and a half decades ago, particularly in research settings. The advantages of lentiviral vectors for treating diseases of genetic origin have driven research into their large-scale manufacture for clinical settings. Currently, three main challenges exist that limit mass production of lentiviral vectors. First, plasmid DNA used in the production process is very expensive. Second, high …

Control Mapping Methodology For Tailless Morphing-Wing Aircraft, Zachary S. Montgomery

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Advanced aircraft designs tend to have several control surfaces or devices that affect the flight of the aircraft. It is difficult or even impossible for a pilot to directly control each of these devices and fly the aircraft well. Therefore, a control mapping logic is needed to take typical pilot commands and map them to what the control devices should do to achieve the pilot’s commands. This work presents a methodology for determining this control mapping logic using two different approaches. The first uses a theoretical approach based on lifting-line theory, while the second leverages computational methods. The methodology consists …

Study Of Thermoelectric And Lattice Dynamics Properties Of 2d Layered Mx (M = Sn, Pb; X = S, Se, Te) And Zrs2 Compounds Using First-Principles Approach, Abhiyan Pandit

Graduate Theses and Dissertations

The aim of this dissertation is the investigation of thermoelectric and lattice dynamics properties of two-dimensional (2D) MX (M = Sn, Pb; X = S, Se, Te) and ZrS2 compounds based on the first-principles density functional theory. The dimensionality reduction (e.g., using 2D structure) of bulk materials is found to have enhanced thermoelectric efficiency. This enhancement is attributed to the increase of the Seebeck coefficient as a result of higher electronic density of states near the Fermi level in low-dimensional materials. In addition, lowering the dimensionality increases phonon scattering near interfaces and surfaces in 2D materials, which leads to a …

Constraint-Aware, Scalable, And Efficient Algorithms For Multi-Chip Power Module Layout Optimization, Imam Al Razi

Graduate Theses and Dissertations

Moving towards an electrified world requires ultra high-density power converters. Electric vehicles, electrified aerospace, data centers, etc. are just a few fields among wide application areas of power electronic systems, where high-density power converters are essential. As a critical part of these power converters, power semiconductor modules and their layout optimization has been identified as a crucial step in achieving the maximum performance and density for wide bandgap technologies (i.e., GaN and SiC). New packaging technologies are also introduced to produce reliable and efficient multichip power module (MCPM) designs to push the current limits. The complexity of the emerging MCPM …

A Memory-Centric Customizable Domain-Specific Fpga Overlay For Accelerating Machine Learning Applications, Atiyehsadat Panahi

Graduate Theses and Dissertations

Low latency inferencing is of paramount importance to a wide range of real time and userfacing Machine Learning (ML) applications. Field Programmable Gate Arrays (FPGAs) offer unique advantages in delivering low latency as well as energy efficient accelertors for low latency inferencing. Unfortunately, creating machine learning accelerators in FPGAs is not easy, requiring the use of vendor specific CAD tools and low level digital and hardware microarchitecture design knowledge that the majority of ML researchers do not possess. The continued refinement of High Level Synthesis (HLS) tools can reduce but not eliminate the need for hardware-specific design knowledge. The designs …

Etching Process Development For Sic Cmos, Weston Reed Renfrow

Graduate Theses and Dissertations

Silicon Carbide (SiC) is an exciting material that is growing in popularity for having qualities that make it a helpful semiconductor in extreme environments where silicon devices fail. The development of a SiC CMOS is in its infancy. There are many improvements that need to be made to develop this technology further. Photolithography is the most significant bottleneck in the etching process; it was studied and improved upon. Etching SiC can be a challenge with its reinforced crystal structure. Chlorine-based inductively coupled plasma (ICP) etching of intrinsic SiC and doped SiC, SiO2, and Silicon has been studied. A baseline chlorine …

Modeling And Performance Analysis Of Deb Based Hydrogen Getters, John A. Matteson

Chemical and Biological Engineering ETDs

Hydrogen getter materials are used to irreversibly absorb hydrogen gas in sealed environments. The DEB based getter system, despite finding widespread use in this application, still posses challenges with respect to experimental performance analysis and fundamental understanding of reaction mechanism. The second chapter of this report addresses the experimental challenges of this getter system by demonstrating the utility and experimental strengths of a custom magnetic suspension balance (MSB) based gravimetric sorption system. This apparatus enables performance evaluation in process relevant conditions including dilute mixed gas environments which our results indicate is necessary for accurate performance evaluation of getter systems. Chapter …

Combinatorial Cnn Meta-Structures In Deep Learning Applications, Aswathy Rajendra Kurup

Electrical and Computer Engineering ETDs

The study aims in applying combinatorial structures motivated from the basic CNN in various applications. Convolutional neural networks (CNNs) have grown to be very popular in the field of deep learning. The ability of such networks to learn both Spatial and temporal characteristics in the data have helped in deploying them in various fields. Through this research we explore different kinds of CNN-derived architectures and how these structures can be trained and setup in combinatorial environment to solve problems in deep learning applications. First, we introduce the basic idea of a deep learning meta-structures which is used in the application …

Biodegradable Microneedle Patch For Delivery Of Meloxicam For Managing Pain In Cattle, David A. Castilla-Casadiego, Katherine A. Miranda-Munoz, Jesse L. Roberts, Anne D. Crowell, David Gonzalez-Nino, Dipankar Choudhury, Frank O. Aparicio-Solis, Shannon L. Servoss, Adrianne M. Rosales, Gary Prinz, Min Zou, Yuntao Zhang, Johann F. Coetzee, Lauren F. Greenlee, Jeremy Powell, Jorge Almodovar

Chemical Engineering Faculty Publications and Presentations

Microneedle patches are a promising source for transdermal diffusion of macromolecules and are designed to painlessly penetrate the skin. In this study, a biodegradable chitosan microneedle patch to deliver meloxicam for managing pain in cattle was tested. The potential of reuse of the polymeric solution to fabricate the patches, optimization of fabrication, morphological analysis of the microneedle patch and analysis of preservation of the chemical composition after sterilization were evaluated. In-vitro analysis consisted of studying in-vitro penetration mechanical properties, compression testing analysis of microneedle patch, and in-vitro drug release analysis. In-vivo studies were performed to analyze the dissolution capability of …

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 …

Joint Chance-Constrained Staffing Optimization In Multi-Skill Call Centers, Tien Thanh Dam, Thuy Anh Ta, Tien Mai

Research Collection School Of Computing and Information Systems

This paper concerns the staffing optimization problem in multi-skill call centers. The objective is to find a minimal cost staffing solution while meeting a target level for the quality of service (QoS) to customers. We consider a staffing problem in which joint chance constraints are imposed on the QoS of the day. Our joint chance-constrained formulation is more rational capturing the correlation between different call types, as compared to separate chance-constrained versions considered in previous studies. We show that, in general, the probability functions in the joint-chance constraints display S-shaped curves, and the optimal solutions should belong to the concave …

Integrating Forward And Reverse Logistics In Vehicle Routing Problem With Cross-Docking, Vincent F. Yu, Pham T. Anh, Aldy Gunawan

Research Collection School Of Computing and Information Systems

A closed-loop supply chain is one of the vital parts for maintaining the success of enterprises, where forward and reverse logistics are integrated to eliminate wastes (e.g., transportation costs). However, previous studies related to the Vehicle Routing Problem have almost overlooked this integration. This research therefore introduces a variant of the Vehicle Routing Problem with cross-docking (VRPCD) by simultaneously considering three additional factors: (1) various types of vehicles in terms of their capacities and unit travel costs; (2) multiple cross-docks; and (3) the integration of forward and reverse logistics. In particular, the flows of the network consist of distributing goods …

Thermodynamic Modeling Of Hydrogen–Water Systems With Gas Impurity At Various Conditions Using Cubic And Pc-Saft Equations Of State, Amer Alanazi, Saleh Bawazeer, Muhammad Ali, Alireza Keshavarz, Hussein Hoteit

Research outputs 2022 to 2026

Hydrogen (H2) has emerged as a viable solution for energy storage of renewable sources, supplying off-seasonal demand. Hydrogen contamination due to undesired mixing with other fluids during operations is a significant problem. Water contamination is a regular occurrence; therefore, an accurate prediction of H2-water thermodynamics is crucial for the design of efficient storage and water removal processes. In thermodynamic modeling, the Peng–Robinson (PR) and Soave Redlich–Kwong (SRK) equations of state (EoSs) are widely applied. However, both EoSs fail to predict the vapor-liquid equilibrium (VLE) accurately for H2-blend mixtures with or without fine-tuning binary interaction parameters due to the polarity of …

Deep Learning For Robust Adaptive Inverse Control Of Nonlinear Dynamic Systems: Improved Settling Time With An Autoencoder, Nuha A. S. Alwan, Zahir M. Hussain

Research outputs 2022 to 2026

An adaptive deep neural network is used in an inverse system identification setting to approximate the inverse of a nonlinear plant with the aim of constituting the plant controller by copying to the latter the weights and architecture of the converging deep neural network. This deep learning (DL) approach to the adaptive inverse control (AIC) problem is shown to outperform the adaptive filtering techniques and algorithms normally used in adaptive control, especially when in nonlinear plants. The deeper the controller, the better the inverse function approximation, provided that the nonlinear plant has an inverse and that this inverse can be …

Investigating The Microstructural And Mechanical Properties Of Novel Ternary Reinforced Aa7075 Hybrid Metal Matrix Composite, Afnan Haider Khan, Syed Ahmad Ali Shah, Farheen Umar, Uneeb Noor, Rizwan Mahmood Gul, Khaled Giasin, Muhammad Aamir

Research outputs 2022 to 2026

This study investigates the comparison of the microstructural and mechanical properties of a novel ternary reinforced AA7075 hybrid metal matrix composite. Four samples, including AA7075 (base alloy), AA7075-5wt % SiC (MMC), AA7075-5wt %SiC-3wt % RHA (s-HMMC), and AA7075-5wt % SiC-3wt % RHA-1wt % CES (n-HMMC) were developed using the stir casting liquid metallurgy route, followed by the heat treatment. The experimental densities corresponded with the theoretical values, confirming the successful fabrication of the samples. A minimum density of 2714 kg/m3 was recorded for the n-HMMC. In addition, the highest porosity of 3.11 % was found for n-HMMC. Furthermore, an increase …

Lifetime Maximization In Underwater Wireless Communication Networks, Kazi Yasin Islam, Iftekhar Ahmad, Daryoush Habibi, Jiong Jin, Muhammad Waqas

Research outputs 2022 to 2026

The rise in demand for underwater wireless communication networks (UWCN) has been driven by the emergence of new applications including unmanned underwater vehicles, deep-sea exploration, maritime and underwater archaeology research, and diver communications. For various applications, underwater network lifetime must be long, since unlike terrestrial sensor networks, it is a major job to change/recharge node batteries in underwater environments. In this paper, we introduce a solution where critical nodes in a UWCN are periodically recharged by small renewable energy sources. Further, a caching mechanism is introduced to relieve critical nodes of heavy workload when their residual energies run low. By …

Controller Platform Design And Demonstration For An Electric Aircraft Propulsion Driv, Rosten Sweeting

Graduate Theses and Dissertations

With the growth in the aerospace industry there has been a trend to optimize the performance of an aircraft by reducing fuel consumption and operational cost. Recent advancements in the field of power electronics have pushed towards the concepts of hybrid electric aircraft also known as more electrical aircrafts. In this work, a custom controller board for an electric aircraft propulsion drive was designed to drive a permanent magnet synchronous motor. Design of the controller board required knowledge of the topology selection and power module selections. Simulations of the system were performed using MATLAB/Simulink to analyze the overall performance of …

Study Of Thin Gan/Ingan/Gan Double Graded Structures For Future Photovoltaic Application, Mirsaeid Sarollahi

Graduate Theses and Dissertations

Indium gallium nitride (In_x Ga_(1-x) N) materials have displayed great potential for photovoltaic and optoelectronic devices due to their optical and electrical properties. Properties such as direct bandgap, strong bandgap absorption, thermal stability and high radiation resistance qualify them as great materials for photovoltaic devices. The tunable bandgap which absorbs the whole solar spectrum is the most significant feature which became attractive for scientists. The bandgap for these materials varies from 0.7 eV for InN to 3.4 eV for GaN covering from infrared to ultraviolet. In_x Ga_(1-x) N wurtzite crystal is grown on GaN buffer layer by Molecular Beam Epitaxy …

Xps And Ipe Determination Of Band Offsets Of Germanium Based Materials, Justin Michael Rudie

Graduate Theses and Dissertations

Germanium tin and silicon germanium tin are group IV semiconductor alloys that have gained significant interest in recent years for their potential use in optoelectrical devices. While silicon and germanium are indirect bandgap materials on their own, alloying them with tin in sufficient quantities leads to a transition to direct bandgap alloys. Direct gap performance opens the door for efficient light emitting and detecting devices fabricated entirely on group IV materials that are compatible with the industry standard CMOS manufacturing techniques. Germanium tin and silicon germanium tin have bandgaps that respond to light in the mid to near infrared spectrum …

Materials Design For Energy Applications Using Ab- Initio Calculations, Hind Hemaidee Alqurashi

Graduate Theses and Dissertations

The structural, dynamical, electronic, and thermoelectric properties of rock-salt and wurtzite Cd1-xZnxO alloys, VTiRhZ (Al, Ga, In, Si, Ge, Sn) and ZrTiRhZ (Ge, Sn) quaternary Heusler alloys (QHAs) were investigated using density functional theory (DFT) and semi-classical Boltzmann transport theory. From these calculations, the alloys were identified as potential materials for future thermoelectric applications. Furthermore, the magnetic and spin-polarization properties of these QHAs were investigated. The total magnetic moments were found to be integer values for all QHAs. In addition, all studied QHAs except VTiRhAl possess a half-metallic behavior with a 100% spin-polarization. The half-metallic ferromagnetic behavior makes them promising …

Fabrication And Non-Covalent Functionalization And Characterization Of Graphene-Based Devices On Novel Substrate Cadmium Trithiophosphate (Iv) — Cdps, Abayomi Omotola Omolewu

Graduate Theses and Dissertations

With graphene at the center of several application areas such as sensing, circuits, high-frequency devices for communication systems, etc., it is crucial to understand how the intrinsic properties of devices made from graphene and other materials like platinum and palladium nanoparticles affect the performance of such devices for the specific application area. Many graphene-based devices for different application areas have focused mainly on the material composition of the graphene-based devices and how it affects performance parameters for the specific application. However, it would be insightful to understand how the intrinsic electrical properties of the graphene devices for different applications affect …

The Effect Of Water Management And Ratoon Rice Cropping On Methane Emissions And Harvest Yield In Arkansas, Marguerita Leavitt

Graduate Theses and Dissertations

Sustainable intensification of rice farming is crucial to meeting human food needs while reducing environmental impacts. Rice produces 8% of all anthropogenic CH4, which is a potent greenhouse gas. CH4 emissions can potentially be reduced by cultivation practices that minimize the number of days the fields are saturated, such as dry-seeding instead of water-seeding and irrigation using the alternate wetting and drying (AWD) technique instead of delayed, continuous flooding (DF). Ratoon cropping, wherein a second crop of rice is grown from the harvested stubble of the first crop, can be used to produce additional yield with minimal labor, but may …

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. …