Engineering Commons^™

Design And Verification Of A Planar, Programmable, Compliant Hand For Use In General Open-Loop Constrained Manipulation, Jacob Frye

Master's Theses (2009 -)

Conventional robots are adept at performing tasks where the desired absolute position of the robot's end effector is well defined. However, these robots will struggle with tasks in which the desired position is poorly defined, subject to variation, or determined by contact with a constraint with positional uncertainty. This problem can be solved by introducing compliance to the system, either active or passive. Active compliance uses force feedback to make corrective motions, but is limited in speed and experiences higher contact forces than passive systems. Passively compliant systems are capable of realizing the necessary compliance for a given task but …

The Effects Of Lead, Copper, And Iron Corrosion Products On Antibiotic Resistant Bacteria And Antibiotic Resistance Genes, Veronika Folvarska, San Marie Thomson, Zihao Lu, Maya Adelgren, Adam Schmidt, Ryan J. Newton, Yin Wang, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Antibiotic resistance is a public health crisis. Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are present in drinking water distribution systems. Metals are known selective pressures for antibiotic resistance, and metallic corrosion products are found within drinking water distribution systems due to the corrosion of metal pipes. While corrosion products are a source of metals, the impact of specific corrosion products on antibiotic resistance has not been investigated. The objective of this study was to determine the impact of six corrosion products—CuO, Cu₂O, Pb₅(PO₄)₃OH, β-PbO₂, Fe₃O …

Cervical Spinal Cord Angiography And Vessel-Selective Perfusion Imaging In The Rat, Seongtaek Lee, Brian Schmit, Shekar N. Kurpad, Matthew D. Budde

Biomedical Engineering Faculty Research and Publications

Arterial spin labeling (ASL) has been widely used to evaluate arterial blood and perfusion dynamics, particularly in the brain, but its application to the spinal cord has been limited. The purpose of this study was to optimize vessel-selective pseudocontinuous arterial spin labeling (pCASL) for angiographic and perfusion imaging of the rat cervical spinal cord. A pCASL preparation module was combined with a train of gradient echoes for dynamic angiography. The effects of the echo train flip angle, label duration, and a Cartesian or radial readout were compared to examine their effects on visualizing the segmental arteries and anterior spinal artery …

Environmental Drivers Impact The Accumulation And Diversity Of Antibiotic Resistance In Green Stormwater Infrastructure, Kassidy N. O'Malley, Patrick J. Mcnamara, Christopher Marshall, Emily Lou Lamartina, Thuy Duyen Lam, Numair Ali, Walter M. Mcdonald

Civil and Environmental Engineering Faculty Research and Publications

Antibiotic resistance poses an urgent public health concern, with the environment playing a crucial role in the development and dissemination of resistant bacteria. There is a growing body of research indicating that stormwater is a significant source and transport vector of resistance elements. This research sought to characterize the role of green stormwater infrastructure (GSI), designed for stormwater infiltration, in accumulating and propagating antibiotic resistance in the urban water cycle. Sampling included 24 full-scale GSI systems representing three distinct types of GSI - bioswales, bioretention cells, and constructed wetlands. The results indicated that GSI soils accumulate antibiotic resistance genes (ARGs) …

Quantifying Image Quality In Aoslo Images Of Photoreceptors, Brea D. Brennan, Heather Heitkotter, Joseph Carroll, Sergey Tarima, Robert F. Cooper

Biomedical Engineering Faculty Research and Publications

The use of “quality” to describe the usefulness of an image is ubiquitous but is often subject to domain specific constraints. Despite its continued use as an imaging modality, adaptive optics scanning light ophthalmoscopy (AOSLO) lacks a dedicated metric for quantifying the quality of an image of photoreceptors. Here, we present an approach to evaluating image quality that extracts an estimate of the signal to noise ratio. We evaluated its performance in 528 images of photoreceptors from two AOSLOs, two modalities, and healthy or diseased retinas. The algorithm was compared to expert graders’ ratings of the images and previously published …

Spatial Correspondence Of Cortical Activity Measured With Whole Head Fnirs And Fmri Toward Clinical Use Within Subject, Anthony Zinos, Julie C. Wagner, Scott A. Beardsley, Wei-Liang Chen, Lisa Conant, Marsha Malloy, Joseph Heffernan, Brendan Quirk, Robert W. Prost, Mohit Maheshwari, Jeffrey Sugar, Harry T. Whelan

Biomedical Engineering Faculty Research and Publications

Functional near infrared spectroscopy (fNIRS) and functional magnetic resonance imaging (fMRI) both measure the hemodynamic response, and so both imaging modalities are expected to have a strong correspondence in regions of cortex adjacent to the scalp. To assess whether fNIRS can be used clinically in a manner similar to fMRI, 22 healthy adult participants underwent same-day fMRI and whole-head fNIRS testing while they performed separate motor (finger tapping) and visual (flashing checkerboard) tasks. Analyses were conducted within and across subjects for each imaging approach, and regions of significant task-related activity were compared on the cortical surface. The spatial correspondence between …

Material Modeling Of An Ultraviolet Sensitive Resin At High Pressures And Rates, Truman Miller Russell

Master's Theses (2009 -)

A full understanding of the behavior of binder materials under shock loading is required for effective simulation of heterogeneous polymer-binder-explosives (PBX) and polymer-binder-surrogate (PBS) systems. An accurate simulation is critical for the ultimate goal of designing meso-scale heterogeneous PBS systems. The binder materials studied here is an ultraviolet sensitive resin (UV resin). The UV resin is manufactured by AnyCubic. It is a glassy thermoset polymer and is known to be similar to polymethyl methacrylate (PMMA) both in mechanical properties and in chemical makeup. This material was chosen as it can be additively manufactured, and it will present a lower impedance …

A Study Of The Effect Of Preparation Parameters On The Mechanical Properties Of Freeze-Dried Gelatin-Elastin-Hyaluronate Scaffolds, Mansour Qamash

Master's Theses (2009 -)

This thesis is dedicated to a detailed study of changes in the properties of Gelatin-Elastin-Hyaluronate (GEH) tissue engineering scaffold resulting from changes in preparation parameters. More specifically, utilizing a combination of foaming and freeze-drying techniques, this research investigates the effects of different parameters, including agitation speed, duration time, and chilling temperature on the scaffold’s structural integrity, porosity, and mechanical properties. The methodology involves a carefully calibrated process in which the scaffold matrix is initially prepared by incorporating 8% gelatin, 2% elastin, and 0.5% hyaluronate (w/v) into a homogenous aqueous solution, followed by controlled agitation and subsequent freezing at designated temperatures. …

Investigating The Impacts Of Bin Variability On Particle Size Distributions In Multiphase Eulerian-Eulerian Simulations, Wilbert Alexander Cruz

Master's Theses (2009 -)

In this study, a 3D steady-state Eulerian-Eulerian simulation was developed to investigate flow performance in a dilute pneumatic conveying system. The investigation focused on two main objectives: (1) assessing the influence of bin selection on solution accuracy for representing the polydisperse mixture, and (2) exploring methods to simplify the modeling of polydisperse particles in the simulation by utilizing a mean diameter derived from the mixture’s particle size distribution. The system's geometry and initial boundary conditions featured a 10.6 m long, 150 mm diameter horizontal pipe with both gaseous and solid phases initially moving at 27 m/s . The steady-state simulation …

Antibiotic Resistance In Urban Stormwater Runoff And Green Stormwater Infrastructure, Kassidy N. O'Malley

Dissertations (1934 -)

Antibiotic resistance in the environment poses significant risks to human health, especially through the transmission of antibiotic resistance genes (ARGs) and antibiotic-resistant bacteria (ARB) via pathways like food and water. Urban stormwater runoff has been identified as a significant contributor to the release and transport of ARGs in the environment but has remained under-researched. This dissertation aimed to address this gap by investigating the fate of ARGs in urban stormwater runoff to guide future stormwater management decisions. Two phases were completed; the first sought to investigate extracellular antibiotic resistance genes (eARGs) in stormwater runoff, and the second focused on quantifying …

Longitudinal Changes In Diffusion Tensor Imaging In Hemodialysis Patients, Wesley T. Richerson, Brian D. Schmit, Dawn F. Wolfgram

Biomedical Engineering Faculty Research and Publications

Introduction

Hemodialysis patients have increased white matter and gray matter pathology in the brain relative to controls based on MRI. Diffusion tensor imaging is useful in detecting differences between hemodialysis and controls but has not identified the expected longitudinal decline in hemodialysis patients. In this study we implemented specialized post-processing techniques to reduce noise to detect longitudinal changes in diffusion tensor imaging parameters and evaluated for any association with changes in cognition.

Methods

We collected anatomical and diffusion MRIs as well as cognitive testing from in-center hemodialysis patients at baseline and 1 year later. Gray matter thickness, white matter volume, …

People With Degenerative Cervical Myelopathy Have Impaired Reactive Balance During Walking, Timothy F. Boerger, Learon Mcginn, Megan Bellman, Marjorie C. Wang, Brian D. Schmit, Allison S. Hyngstrom

Physical Therapy Faculty Research and Publications

Background

People with degenerative cervical myelopathy are known to have impaired standing balance and walking abilities, but less is known about balance responses during walking.

Research question

The aim of this project was to assess reactive balance impairments during walking in people with degenerative cervical myelopothy (PwDCM). We hypothesized that center of mass motion following perturbations would be larger in PwDCM and gluteus medius electromyographic amplitude responses would be decreased in PwDCM.

Methods

Reactive balance responses were quantified during unanticipated lateral pulls to the waist while treadmill walking. Walking biomechanics data were collected from 10 PwDCM (F=6) and 10 non-myelopathic …

Effect Of Heavy-Duty Electric Vehicles On Tire–Pavement Contact Forces, Jaime Hernandez, Angeli Jayme, Johann J. Cardenas Huaman, Imad L. Al-Qadi

Civil and Environmental Engineering Faculty Research and Publications

Electric vehicles offer higher acceleration than conventional internal combustion engines due to larger engine torque. The design and placement of battery packs in heavy-duty electric vehicles are still being optimized, as they can affect axle load distributions and consequently impact pavement analysis and design. This study presents a finite element model of a dual tire assembly considering varying load and acceleration conditions to investigate the effect of conventional and electric heavy-duty vehicles on tire–pavement contact forces. Three scenarios for battery pack locations were examined, leading to six loading conditions for both internal combustion engines and electric trucks. The resulting 3D …

Quaternary Ammonia Compounds In Disinfectant Products: Evaluating The Potential For Promoting Antibiotic Resistance And Disrupting Wastewater Treatment Plant Performance, Zihao Lu, Anna K. Mahony, William A. Arnold, Christopher Marshall, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Quaternary ammonium compounds (QACs) are a class of compounds that were widely used as disinfectants during the COVID-19 pandemic and continue to be used as disinfecting agents. After consumer usage, QAC concentrations are diluted in wastewater as they enter wastewater treatment plants. At sub-inhibitory concentrations, QACs may have unintended repercussions, including increased antibiotic resistance and inhibition of process performance in wastewater treatment plants. This review first summarizes how QACs inhibit bacteria and then highlights the mechanisms by which QACs can promote antibiotic resistance in general. Reported environmental concentrations of QACs are compared to concentrations that are suspected to impact antibiotic …

Verification And Validation Of Pavement Models, Jaime Hernandez, Angeli Jayme, Hasan Ozer, Eyal Levenberg, Lev Khazanovich, Emin M. Kutay

Civil and Environmental Engineering Faculty Research and Publications

Model development activities are increasing in pavement research and engineering applications. At the same time, there is ambiguity and a lack of consistency with regard to checking and quantifying credibility and suitability for the intended application. Specifically, usage of the terms Verification and Validation (V&V) is seen to vary across contributions. In this context, this paper was motivated by the desire to provide a best-practice reference that underlines the significance of the V&V terms, clarifies their definition, and promotes a more unified usage. Accordingly, the objective was to offer examples that introduce the V&V jargon, demonstrate basic V&V concepts and …

Stormwater Alters The Resistome Of Urban Surface Water, An Impact That Can Be Mitigated By Green Stormwater Infrastructure, Kassidy N. O'Malley, Walter M. Mcdonald, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Antibiotic resistance poses an escalating threat to global health, with environmental reservoirs being pivotal areas of concern, as well as opportunities for potential mitigation. Stormwater systems are an important type of environmental reservoir in the urban water cycle with a dearth of research related to impacts on antibiotic resistance. In particular, there has been limited research exploring the impact of diverse antibiotic resistance genes (ARGs) carried by stormwater from various land uses on surface water, nor has there been an examination of the role played by green stormwater infrastructure (GSI) in mitigating this impact. Therefore, this study sought to elucidate …

Gamma Amplitude-Envelope Correlations Are Strongly Elevated Within Hyperexcitable Networks In Focal Epilepsy, Manoj Raghavan, Jared Pilet, Chad Carlson, Christopher T. Anderson, Wade Mueller, Sean Lew, Candida Ustine, Priyanka Shah-Basak, Vahab Youssofzadeh, Scott A. Beardsley

Biomedical Engineering Faculty Research and Publications

Methods to quantify cortical hyperexcitability are of enormous interest for mapping epileptic networks in patients with focal epilepsy. We hypothesize that, in the resting state, cortical hyperexcitability increases firing-rate correlations between neuronal populations within seizure onset zones (SOZs). This hypothesis predicts that in the gamma frequency band (40–200 Hz), amplitude envelope correlations (AECs), a relatively straightforward measure of functional connectivity, should be elevated within SOZs compared to other areas. To test this prediction, we analyzed archived samples of interictal electrocorticographic (ECoG) signals recorded from patients who became seizure-free after surgery targeting SOZs identified by multiday intracranial recordings. We show that …

Designing A Use-Error Robust Machine Learning Model For Quantitative Analysis Of Diffuse Reflectance Spectra, Allison Scarbrough, Keke Chen, Bing Yu

Biomedical Engineering Faculty Research and Publications

Significance

Machine learning (ML)-enabled diffuse reflectance spectroscopy (DRS) is increasingly used as an alternative to the computation-intensive inverse Monte Carlo (MCI) simulation to predict tissue’s optical properties, including the absorption coefficient,μaand reduced scattering coefficient, μs′.

Aim

We aim to develop a use-error-robust ML algorithm for optical property prediction from DRS spectra.

Approach

We developed a wavelength-independent regressor (WIR) to predict optical properties from DRS data. For validation, we generated 1520 simulated DRS spectra with the forward Monte Carlo model, where μa=0.44 to 2.45cm−1, and μs′=6.53 to 9.58cm−1. We introduced common use-errors, such as wavelength miscalibrations and intensity fluctuations. Finally, we …

Cross-Temporal Hierarchical Forecast Reconciliation Of Natural Gas Demand, Colin O. Quinn, George F. Corliss, Richard J. Povinelli

Electrical and Computer Engineering Faculty Research and Publications

Local natural gas distribution companies (LDCs) require accurate demand forecasts across various time periods, geographic regions, and customer class hierarchies. Achieving coherent forecasts across these hierarchies is challenging but crucial for optimal decision making, resource allocation, and operational efficiency. This work introduces a method that structures the gas distribution system into cross-temporal hierarchies to produce accurate and coherent forecasts. We apply our method to a case study involving three operational regions, forecasting at different geographical levels and analyzing both hourly and daily frequencies. Trained on five years of data and tested on one year, our model achieves a 10% reduction …

Quaternary Ammonium Compounds (Qacs) In Wastewater Influent And Effluent Throughout The Covid-19 Pandemic, Anna K. Mahony, Patrick J. Mcnamara, William A. Arnold

Civil and Environmental Engineering Faculty Research and Publications

Quaternary ammonium compounds (QACs) are used in consumer and industrial products, including disinfectants. Due to the COVID-19 pandemic, disinfectant use has increased, purportedly increasing loads to wastewater treatment plants and the environment. To understand how the increased usage has affected QAC loadings to treatment plants and to determine how effectively plants remove QACs from liquid effluent that is discharged to surface and groundwaters, influent and effluent wastewater samples were collected from four treatment plants (treatment capacities < 5 MGD to > 100 MGD) for 21 months beginning in May 2020. Influent QAC concentrations were hundreds of μg/L and effluent QAC concentrations were < 1 μg/L, corresponding to an average removal of 98% from all four plants. The most prevalent QACs in influent were those used most commonly in disinfectants, specifically benzylalkyldimethylammonium compounds (BACs) and short-chain dialkyldimethylammonium compounds (DADMACs), and influent levels of these compounds were correlated with QAC sales. Prior to this study, ethylbenzylalkyldimethylammonium compounds (EtBACs) had not been studied, and they comprised 13 ± 6% of QACs in influent. While removal was high at all plants, low μg/L concentrations were still continuously discharged into the environment. For QACs with equivalent alkyl chain lengths, those with aromatic substituents (BACs and EtBACs) appear to be removed more effectively than those with only alkyl chains (DADMACs).

Integrated Tire Wear Buildup And Rainfall-Runoff Model To Simulate Tire Wear Particles In Stormwater, Matthew Dupasquier, Jaime Hernandez, Alondra Gonzalez, Cesar Aguirre, Walter M. Mcdonald

Civil and Environmental Engineering Faculty Research and Publications

This paper presents an approach to integrate tire wear buildup and rainfall-runoff models to simulate tire wear buildup on road surfaces and its subsequent transport in stormwater runoff events. To do so, a buildup model is presented based on vehicle kilometers traveled, vehicle type, vehicle speed, and road roughness within a watershed. This buildup model was integrated into an EPA SWMM model that simulated the runoff of tire wear particles in twelve watersheds in the San Francisco, CA bay area. Results demonstrate that tire wear particle buildup within the watersheds ranged between 0.4 and 0.51 (kg/km2) per hour. Applied to …

Peroxi-Electrocoagulation For Treatment Of Trace Organic Compounds And Natural Organic Matter At Neutral Ph, Donald R. Ryan, Patrick J. Mcnamara, Claire K. Baldus, Yin Wang, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

Iron-based oxidation technologies can be advantageous for mitigating trace organic compounds (TOrCs) during water and wastewater treatment due to their production of hydroxyl radicals. However, iron-based oxidation often occurs at acidic pH to promote Fenton's reaction, which limits the processes' feasibility for treatment applications. This study focused on utilizing iron-electrocoagulation (EC) paired with ex situ H₂O₂ addition (peroxi-electrocoagulation [EC:H₂O₂]) to promote oxidative reactions at neutral pH conditions. The hydroxyl radical probe para-chlorobenzoic acid (pCBA) was used to gauge oxidant activity and serve as a representative TOrC. The impact of water …

Improving Benign Paroxysmal Positional Vertigo Diagnosis, Sida Zhang

Master's Theses (2009 -)

Benign Paroxysmal Positional Vertigo (BPPV) is one of the most common causes of dizziness. Especially for people over 45, the risk of BPPV is substantial. On the other hand, BPPV is often misdiagnosed and may require expensive examinations. This thesis introduces a prediction model based on machine learning to quickly, inexpensively, and accurately diagnose BPPV. The thesis starts by introducing BPPV and the statistics of BPPV misdiagnosis. Then, a patient survey is introduced. The patient survey includes 50 BPPV-related questions, which are used as training data for the machine learning model. Logistic Regression, Decision Tree, and Naïve Bayes were compared …

Reduced Bias User Preference Methods For Determining The Pareto-Optimal Solution Point, Dylan Thomas Johnson

Master's Theses (2009 -)

Engineering design is filled with tradeoffs between competing objectives such as performance, mass, cost, and schedule. A designer must navigate these complex multi-objective problems and deliver the right solution for their application. Multi-objective optimization techniques are powerful and widely used; however, a key drawback to these techniques is that they often output a set of equivalent solutions called the Pareto Front. The designer must perform an additional multi-objective down selection on the Pareto Front to determine a single Pareto-optimal solution point for their design. Existing Pareto Front processing techniques either use traditional infinitely adjustable weights, which can yield results that …

Design And Validation Of A Variable Stiffness Three Degree Of Freedom Planar Robot Arm, Andrew L. Bernhard

Master's Theses (2009 -)

The need exists for robotic manipulators that can interact with an environment having uncertain kinematic constraints. A robot has been designed and built for proof of concept of a passive variable compliance control strategy that can vary joint stiffness to achieve higher performance dexterous manipulation. This novel planar robot incorporating variable stiffness actuators and common industrial controls allows the robot to comply with its environment when needed but also have high stiffness for precise motion control in free space. To perform both functions well, a high stiffness ratio (max/min stiffness) is required. A stiffness ratio up to 492 was achieved. …

Multi-Port Power Converters For Hybrid Energy System Applications, Sina Vahid

Dissertations (1934 -)

The increasing integration of renewable energy sources and energy storage systems in various electrical systems introduces the topic of hybrid energy systems. Power electronics converters play a pivotal role in transforming and transferring the power between energy sources, energy storage systems, and the loads. The traditional approach of using multiple power converters for each of the mentioned components poses challenges including high cost, decrease in the system power density, and communication between the power converters. Multi-port power converters have been proposed as an alternative to employing multiple power converters. Even though several multi-port converters have been proposed in literature, the …

The Role Of Membrane Porosity In Ion Removal By Ro/Nf Membranes And Development Of A Regenerable Pac-Loaded Membrane, Yizhi Hou

Dissertations (1934 -)

Reverse osmosis (RO) and nanofiltration (NF) membranes are widely used for water treatment applications. They are charged porous materials, in which size exclusion and charge exclusion work together to dictate solute transport. In this study, membrane porosity was primarily determined by pore size. Thicker, more porous membranes with smaller pores had higher NaCl removal and less permeate water flux. Higher porosity membranes have greater inner pore surface area available to support a greater number of functional groups, thereby rejecting ion flux and increasing ion removal. The Donnan steric pore model (DSPM) was used to determine that the contribution of diffusion …

Antibiotic Resistance In Urban Stormwater: A Review Of The Dissemination Of Resistance Elements, Their Impact, And Management Opportunities, Kassidy N. O'Malley, Walter M. Mcdonald, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

The public health crisis of antibiotic resistance is a growing threat across the world that is only expected to intensify in the coming years. The cycling of antibiotic resistance genes (ARGs) in the environment via urban stormwater runoff is one means by which humans are exposed to resistant bacteria as traditional gray stormwater infrastructure facilitates the transport of resistance elements into water bodies utilized by the public. In this review, existing research on the occurrence of ARGs in urban stormwater runoff is critically reviewed with the goal of determining the role of stormwater in the dissemination and development of antibiotic …

Impact Of Corrosion Inhibitors On Antibiotic Resistance, Metal Resistance, And Microbial Communities In Drinking Water, Lee K. Kimbell, Emily Lou Lamartina, Stan Kohls, Yin Wang, Ryan J. Newton, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Corrosion inhibitors, including zinc orthophosphate, sodium orthophosphate, and sodium silicate, are commonly used to prevent the corrosion of drinking water infrastructure. Metals such as zinc are known stressors for antibiotic resistance selection, and phosphates can increase microbial growth in drinking water distribution systems (DWDS). Yet, the influence of corrosion inhibitor type on antimicrobial resistance in DWDS is unknown. Here, we show that sodium silicates can decrease antibiotic resistant bacteria (ARB) and antibiotic-resistance genes (ARGs), while zinc orthophosphate increases ARB and ARGs in source water microbial communities. Based on controlled bench-scale studies, zinc orthophosphate addition significantly increased the abundance of ARB …

Bilateral Arm Movements Are Coordinated Via Task-Dependent Negotiations Between Independent And Codependent Control, But Not By A “Coupling” Control Policy, Nick M. Kitchen, Jisung Yuk, Andrzej Przybyla, Robert A. Scheidt, Robert L. Sainburg

Biomedical Engineering Faculty Research and Publications

Prior research has shown that coordination of bilateral arm movements might be attributed to either control policies that minimize performance and control costs regardless of bilateral symmetry or by control coupling, which activates bilaterally homologous muscles as a single unit to achieve symmetric performance. We hypothesize that independent bimanual control (movements of one arm are performed without influence on the other) and codependent bimanual control (two arms are constrained to move together with high spatiotemporal symmetry) are two extremes on a coordination spectrum that can be negotiated to meet infinite variations in task demands. To better understand and distinguish between …