Engineering Commons^™

Redesign And Quantitative Assessment Of An Accelerated Venous Valve Fatigue Apparatus, Megan Kueh

Biomedical Engineering Undergraduate Honors Theses

Chronic venous insufficiency (CVI) is a form of cardiovascular disease that is caused when valves in the leg become incompetent. Current treatment methods serve to manage symptoms, but there are currently no ways to treat the underlying cause of CVI. A venous valve prosthetic made from a xenograft of a bovine jugular vein is one possible treatment method currently in the research phase. Prosthetic valves must be tested with an accelerated wear tester prior to approval for clinical testing. Although such testers exist for heart valves, physiological differences between heart and venous valves restrict the use those testers on venous …

The Utilization Of Autofluorescence To Study The Effects Of L-Buthionine-Sulfoximine On Cellular Metabolism In Vitro, Madison Belew

Biomedical Engineering Undergraduate Honors Theses

Oxidative damage and stress impacts metabolic activity and has been implicated in a number of diseases . These medical conditions have been found to be associated with a lack of glutathione (GSH). There is a need to study the effects that the absence of glutathione has in order to expand knowledge of indicators that cause conditions like cataracts, cancer, or impaired wound healing. L-buthionine-sulfoximine (BSO) has been used in past studies to hinder GSH production and induce oxidative stress within a cell. This study explores the effects of BSO and induced oxidative stress on the metabolic activity and processes within …

Cascaded Linear Regulator With Positive Voltage Tracking Switching Regulator, Brandon K. Nghe

Master's Theses

This thesis presents the design, simulation, and hardware implementation of a proposed method for improving efficiency of voltage regulator. Typically, voltage regulator used for noise-sensitive and low-power applications involves the use of a linear regulator due to its high power-supply rejection ratio properties. However, the efficiency of a linear regulator depends heavily on the difference between its input voltage and output voltage. A larger voltage difference across the linear regulator results in higher losses. Therefore, reducing the voltage difference is the key in increasing regulator’s efficiency. In this thesis, a pre switching regulator stage with positive voltage tracking cascaded to …

The Design And Analysis Of Large Solar Pv Farm Configurations With Dc Connected Battery Systems, Oluwaseun M. Akeyo, Vandana Rallabandi, Nicholas Jewell, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Typically, solar inverters curtail or “clip” the available power from the PV system when it exceeds the maximum ac capacity. This paper discusses a battery system connected to the dc-link of an inverter to recuperate this PV energy. Contrary to conventional approaches, which employ two dc-dc converters, one each for the battery and solar PV system, the proposed configuration utilizes a single dc-dc converter capable of simultaneously operating as a charge controller and a maximum power point tracking (MPPT) tracking device. In addition to improving the overall system capacity factor, increasing the conversion efficiencies and ensuring MPPT stability, the proposed …

Monolithic Chalcogenide Optical Nanocomposites Enable Infrared System Innovation: Gradient Refractive Index Optics, Myungkoo Kang, Laura Sisken, Charmayne Lonergan, Andrew Buff, Anupama Yadav, Claudia Goncalves, Cesar Blanco, Peter Wachtel, J. David Musgraves, Alexej V. Pogrebnyakov, Erwan Baleine, Clara Rivero-Baleine, Theresa S. Mayer, Carlo G. Pantano, Kathleen A. Richardson

Materials Science and Engineering Faculty Research & Creative Works

The size and weight of conventional imaging systems is defined by costly non-planar lenses and the complex lens assemblies required to minimize optical aberrations. The ability to engineer gradient refractive index (GRIN) optics has the potential to overcome constraints of traditional homogeneous lenses by reducing the number of components in optical systems. Here, an innovative strategy to realize this goal based on monolithic GRIN media created in Ge-As-Se-Pb chalcogenide infrared nanocomposites is presented. A gradient heat treatment to spatially modulate the volume fraction of high refractive index Pb-rich nanocrystals within a glass matrix is utilized, providing a GRIN profile while …

Advancing Space Flight Medical Care Through On-Demand Protein Therapeutic Production Capabilities, Emily Long Zhao

Utah Space Grant Consortium

Cell-free protein synthesis (CFPS) is an in vitro protein synthesis system that provides a uniquely adaptable platform for protein production. In recent years, lyophilization of CFPS have expanded the capabilities of this system by improving reagent stability outside of cold-chain storage. This project sought to utilize lyophilized CFPS reagents to develop a convenient, shelf-stable, on-demand therapeutic protein production platform. The therapeutic protein production potential of this novel platform was demonstrated by the successful expression of an FDA approved therapeutic protein. With the advancement of shelf-stable, on-demand protein therapeutic production platforms comes the potential to provide point-of-care medical treatment for space-flight …

Aerodynamic Interactions Of Synchronized Propellers, Nathan Welker, Samuel Johnson

Utah Space Grant Consortium

Emerging advances in electric-propulsion technology are enabling aircraft to use distributed electric propulsion (DEP) to increase efficiency and maneuverability. Distributed electric propulsion can also provide unique take-off and landing abilities which are not commonly found on traditional aircraft. The implementation of DEP effectively decreases the spacing between propellers, introducing complex aerodynamic interactions that are not well understood. This study aims to obtain experimental measurements of the flow fields of synchronized propellers at close-proximity in a side-by-side configuration using particle image velocimetry (PIV) in a wind tunnel. The results of this work will be focused on identifying the impact closely-spaced propellers …

Comparison Of Wake Expansion Methods For Use In Wake Expansion Continuation Optimization, Jared J. Thomas

Utah Space Grant Consortium

This paper presents a comparison of three methods for expanding the wake for use with wake expansion continuation (WEC) optimization. A process related to continuation optimization methods for reducing multi-modality in the wind farm layout optimization problem. A reduction in multi-modality is achieved by starting with an increased wake spread, while maintaining normal velocity deficits at the center of the wakes, and then reducing the wake spread for each of a series of optimization runs until the standard wake spread is used. Three wake expansion methods were tested: (1) increasing the wake expansion angle, (2) multiplying the wake diameter, and …

Monte-Carlo Methods And The Step-Back Kalman Filter For Orbital State Estimation, Louis Tonc

Utah Space Grant Consortium

This research assesses the performance of filtering schemes for tracking uncooperative satellites through space-based optical measurements, and identifies a simple and numerically stable methodology that ameliorates the poor performance of standard filtering schemes at a substantially reduced cost in comparison to nonlinear particle filter-based remedies. Traditional filtering schemes, such as the extended Kalman filter (EKF) and unscented Kalman filter (UKF), both diverge when tracking a resident space object (RSO) in geosynchronous orbit (GEO) when there is a long time duration between measurements. This divergence is identified as a consequence of nonlinearity in the dynamics and nonlinearity in the optical measurements, …

One-Dimensional Turbulence Modeling Of Soot Formation And Transport In Non-Premixed Turbulent Flames, Victoria B. Stephens

Utah Space Grant Consortium

Soot modeling in turbulent flames involves tightly coupled problems of combustion chemistry, particle transport, compressible fluid dynamics, and turbulence behavior in addition to soot chemistry and transport. Significant uncertainties accompany soot modeling and transport in such systems, hindering progress toward accurate combustion models and predictive simulation tools. The one-dimensional turbulence (ODT) model, using a stochastic approach to turbulence modeling, captures the full range of length and time scales in a simulation and provides detailed statistical data of the flow con-figuration, chemistry, and particle transport. Previously, ODT has demonstrated accuracy and computational efficiency compared to direct numerical simulation (DNS) of turbulent, …

Ultra-Low Power Adcs For Space Sensors And Instruments, Shea Smith, Wood Chiang

Utah Space Grant Consortium

A 28nm 0.1V 10-bit 2kS/s Successive Approximation Register ADC design is proposed. This design opens the doors to both low supply and low power space sensors and instruments. Due to the stringent voltage supply unique challenges arise that are met with innovation in the sample switch and comparator design. These components of the ADC architecture are optimized to perform successfully at a 0.1V supply with a sample rate suitable for most sensor applications.

Development Of An Inertial Measurement-Based Assessment Of Disease Severity In Chronic Fatigue Syndrome, Turner Palombo, Suzanne Vernon, Shad Roundy

Utah Space Grant Consortium

While myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is relatively new and poorly understood, a recent upsurge in research has identified the disease’s core symptoms, including post-exertional malaise and orthostatic intolerance. The FDA has yet to approve any treatments for ME/CFS, partially due to a lack of validated efficacy endpoints.

The central focus of this research is to develop ME/CFS efficacy endpoints using a non-invasive, inertial measurement-based approach. Accessible endpoints will provide a way to properly evaluate potential treatments for ME/CFS. Using a Kalman filter, inertial measurement unit (IMU) data can be converted to optimized leg angle estimates. These angle estimates can …

Validating A Finite Element Model With Ansys Workbench For Isotruss® Structures Subject To Uniaxial Compression, Hanna B. Opdahl

Utah Space Grant Consortium

The purpose of this study is to develop, verify, and validate a finite element (FE) model of IsoTruss® structures subject to uniaxial compression. The FE model is implemented in ANSYS WorkBench and verified using axial stiffness and critical buckling loads that are derived from traditional mechanics. The buckling failure modes include global buckling and local bay buckling. The predictions from the FE model and mechanics calculations are validated by experimental data generated in preceding studies. Results indicate that the effective material modulus is highly affected by variations in manufacturing. Adjustment factors are applied to the nominal material properties to accurately …

An Examination Into The Defining Characteristics Of Flexible Solar Aircraft Configurations Through Optimization, Taylor Mcdonnell

Utah Space Grant Consortium

This paper examines the defining characteristics of various solar aircraft configurations through gradient-based multidisciplinary design optimization. We first present a general gradient-based solar aircraft optimization framework which accounts for nonlinear aeroelastic effects resulting from structural flexibility. We then apply this framework to several discrete SR-HALE aircraft geometric, structural, and propulsion system configuration choices to determine the defining characteristics of each configuration choice.

Improving Technologies In Anesthesia, Patrick Kolbay, Joseph Orr

Utah Space Grant Consortium

General anesthesia is well known to offer physicians access to a broad variety of invasive procedures otherwise deemed too risky. Anesthesia machines provides the means for anesthetizing patients safely in the hospital operating room. However, these devices are increasingly unable to meet the demands and needs outside of the hospital. Developing countries struggle to purchase and maintain these costly devices, leading to a 40-fold increase in anesthesia-related deaths compared to developed countries. Small-office practices in the United States experience significantly poorer anesthesia outcomes and increased legal claims versus their larger hospital counterparts, resulting in 60% more anesthesia-related deaths. Environmental impacts …

Masking And Detecting Radiation-Induced Errors In Sram-Based Fpgas Through Partial Circuit Replication, Andrew M. Keller

Utah Space Grant Consortium

Radiation found in terrestrial and space environments can induce errors into SRAM-based FPGAs. Replication of circuitry can be used mask and detect these errors to improve reliability or availability. This work advances the understanding and implementation of partial circuit replication in SRAM-based FPGAs. Partial circuit replication is the replication of a subset of the components in a circuit. A reliability model is presented that evaluates the reliability benefit of partial circuit replication. The model suggests that the reliability benefit is inversely related to the portion of the circuit replicated. A partial triple module redundancy case study is also presented that …

Leveraging Commercial Nuclear Reactors To Power Space Exploration, Ben Johnson

Utah Space Grant Consortium

This study is aimed at exploring the adaptation of commercial nuclear reactors as an alternative to NASA’s current high-power fission reactor systems, particularly with respect to applications on the surface of Mars. The study concludes that while the Kilopower architecture is brilliantly poised to provide affordable, near-term power in the 1-10 kilowatts electric (kWe) range, the financial barrier to higher power scaling of such systems is significant. This financial barrier adds risk to the development of greater than 10kWe systems and is likely to result in the failure to successfully scale the technology to higher powers for space exploration applications. …

Model Reference Predictive Adaptive Control For Large Scale Soft Robots, Phillip Hyatt, Curtis Johnson

Utah Space Grant Consortium

Past work has shown Model Predictive Control (MPC) to be an effective strategy for controlling continuum joint soft robots using rudimentary models, however the in-accuracies of these models often mean that an integration scheme must be combined with MPC. Presented in this work is a novel dynamic model formulation for continuum joint soft robots which is more accurate than the authors’ previous models yet remains fast enough for MPC. This model is based on the Piecewise Constant Curvature (PCC) assumption and a relatively new configuration representation and allows for computationally efficient simulation. Due to the difficulty in determining model parameters …

Three-Dimensional Hydrodynamic Focusing For Integrated Optofluidic Detection Enhancement, Eric Scott Hamilton

Utah Space Grant Consortium

Integrated optofluidics are ideal for high sensitivity detection due to the size of device features being near the small scale of sample particles (10 microns). Novel integrated optofluidic designs enable single molecule detection through hydrodynamic focusing, making the approach ideal for low concentration biosensing. Detection was enhanced and device operation characterized. Further enhancement is promised with optimization of existing designs.

Ensuring Extramobile And Intramobile Motion On Cylindrical Developable Mechanisms, Jared Butler

Utah Space Grant Consortium

Developable mechanisms offer the ability to deploy to perform tasks then return to a hidden position along or interior to a predetermined developable surface. It is often advantageous for these mechanisms to not penetrate the surface along which they conform. This paper presents the limits of extramobile and intramobile motion (motion exterior to and interior to a developable surface). Three conditions are identified that determine a limit of extramobile and intramobile behavior. It is shown that the more difficult of these conditions to predict is never reached prior to the more simple cases. This is demonstrated for all possible Grashof …

Influence Of Electrode Height On Carbon Nanotube Electrochemical Biosensors, Benjamin J. Brownlee

Utah Space Grant Consortium

High sensitivity of electrochemical sensors enables the detection of low concentrations of target analyte. Being able to quickly and accurately detect low concentrations of proteins at point-of-care allows for results to be analyzed more easily and effectively. Having high surface area allows for more analyte to be detected, possibly leading to increased sensitivity. Vertically-aligned carbon nanotubes (VACNTs) were patterned into interdigitated electrodes (IDEs) and then functionalized with the representative protein streptavidin to demonstrate sensing of biotin. Three electrode heights were investigated to determine the influence of electrode height on sensor sensitivity. Cyclic voltammetry and electrochemical impedance spectroscopy were used to …

Evolutionary Nonlinear Model Predictive Control On A Fixed-Wing And Multirotor, Jaron Ellingson, Matthew Haskell

Utah Space Grant Consortium

Real-time model predictive control (MPC) is limited to short time horizons and linear systems because the optimization complexity is too large with long time horizons and nonlinear systems. For this reason, MPC is typically accomplished using linearized models and convex optimization solvers. We seek to explore evolutionary algorithms allowing for nonlinear models and constraints, non-convex costs, and extended time horizons.

Our contributions include extending nonlinear evolutionary MPC to flight vehicles, fixed-wing and multirotor UAVs, as well as enhancing the evolutionary algorithm. We also intend to parameterize the design space of the optimization to reduce solve times. These contributions validate the …

Mechanical Analysis Of Double Network Hydrogels To Determine Suitability As An Articular Cartilage Substitute, Casey Virginia Young

All Theses

The Center for Disease Control has found that between 2013-2015, 26% of women and 19% of men reported doctor-diagnosed cartilage disease or damage. Currently, there exists a substantial population with cartilage damage or disease needing a solution to increasing pain and decreasing function and mobility. Many of these individuals are young and thus looking for a treatment to delay a total knee replacement. Many others are elderly and thus looking to avoid major surgeries, as the riskiness of these procedures increases with age. As researchers look towards a method of cartilage replacement, hydrogels show measurable potential as a synthetic substitute …

Economic Analysis Of Productivity In The Irish Construction Sector, Kpmg, Fac, Róisín Murphy Dr, Avril Behan

Reports

Important strides to enhance productivity in the construction sector have been taken by both industry and Government in recent years. However, a collaborative, sectoral wide strategy to drive further increases in productivity is required, with the coordinated participation of all stakeholders across the full life cycle of a project. This report, commissioned by the Department of Public Expenditure and Reform (DPER), produced by KPMG and Future Analytics Consulting Ltd. (FAC) and peer reviewed by TU Dublin, aims to understand and address the reasons for low levels of productivity in the Irish construction sector and identify specific recommendations and actions that …

Effect Of Socioeconomic Factors On Crash Occurrence, Nikiforos Stamatiadis, Shraddha Sagar, Samantha Wright, Aaron Berry Cambron

Kentucky Transportation Center Research Report

Road traffic crashes are a leading cause of death in the United States. In Kentucky, per capita crash rates and crash-related fatalities have outpaced the national average for over a decade. Wanting to explain why the U.S. Southeast sees higher crash rates than other regions, researchers have argued the region’s unique socioeconomic conditions provide a compelling explanation. Taking this observation as a starting point, this study examined the relationship between highway safety and socioeconomic characteristics using an extensive crash dataset from Kentucky. This research sought to identify at-risk drivers based on the socioeconomic and demographic attributes of the zip codes …

Deep Learning And Polar Transformation To Achieve A Novel Adaptive Automatic Modulation Classification Framework, Pejman Ghasemzadeh

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Automatic modulation classification (AMC) is an approach that can be leveraged to identify an observed signal's most likely employed modulation scheme without any a priori knowledge of the intercepted signal. Of the three primary approaches proposed in literature, which are likelihood-based, distribution test-based, and feature-based (FB), the latter is considered to be the most promising approach for real-world implementations due to its favorable computational complexity and classification accuracy. FB AMC is comprised of two stages: feature extraction and labeling. In this thesis, we enhance the FB approach in both stages. In the feature extraction stage, we propose a new architecture …

Riveted Steel Railway Bridge Health Monitoring And Damage Detection, Ahmed Rageh

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Visual inspection is often used to assess the condition of railway bridges at discrete points in time, an approach that can be subjective and possibly unsafe. Alternatively, certain bridges have their condition assessed via the installation of a large number of sensors. These sensors can be costly to place, power and maintain. Therefore, reducing their numbers and maximizing the extracted information is of utmost importance. In addition, evaluating bridge condition from measured response can be quite challenging due to loading and environmental variations, especially when a limited number of sensors are used.

The focus of this research is to develop …

Comprehensive Second-Order Adjoint Sensitivity Analysis Methodology (2nd-Asam) Applied To A Subcritical Experimental Reactor Physics Benchmark: V. Computation Of Mixed 2nd-Order Sensitivities Involving Isotopic Number Densities, Ruixian Fang, Dan Gabriel Cacuci

Faculty Publications

This work applies the Second-Order Adjoint Sensitivity Analysis Methodology (2nd-ASAM) to compute the mixed 2nd-order sensitivities of a polyethylene-reflected plutonium (PERP) benchmark's leakage response with respect to the benchmark's imprecisely known isotopic number densities and the other benchmark imprecisely known parameters, including: (i) the 6 × 180 mixed 2nd-order sensitivities involving the total microscopic cross sections; (ii) the 6 × 21,600 mixed 2nd-order sensitivities involving the scattering microscopic cross sections; (iii) the 6 × 60 mixed 2nd-order sensitivities involving the fission microscopic cross sections; and (iv) the 6 × 60 mixed 2nd-order sensitivities involving the average number of neutrons produced …

Portable Calorimeter For Fire Experiments, Kayla Collins, Kara Hewson, Christopher Chen, Joel Keddie

Mechanical Engineering

Executive Summary

An oxygen consumption calorimeter works by measuring the heat release rate of a burning substance. This value is calculated by measuring the oxygen and byproducts in smoke from afire.In order to get these values two types of sensors were used. A non-dispersive infrared sensor (NDIR) that measured CO and CO2 and a zirconium O2 sensor were used to find their respective gas concentrations.The design to calculate the heat release rate is focused on maximizing sensor accuracy and portability while simplifying the manufacturing by using off-the-shelf components. The goal included making the system simple to recreate and package in …

Improving Pv Module Efficiency Through Cooling, Blake Bradley

Chemical Engineering Undergraduate Honors Theses

The Solarbacks researched and designed a variety of cooling methods that could be used to improve the efficiency of photovoltaics. These cooling methods can be separated into two categories: active and passive methods. The active cooling method of hydraulic cooling and the passive cooling methods of heat sinks (fins), optical coatings, thermosyphons, phase change materials, and thermoelectric generators were all taken into consideration as potential cooling methods. Passive cooling methods were preferred because the use of electricity required for the cooling mechanism would reduce the net electricity and subsequent profit from the panels.

Two variations of hydraulic cooling were researched: …