Engineering Commons^™

An Investigation Of The Use Of Cerium And Polyhedral Oligomeric Silsesquioxanes For The Protection Of Polymeric Epoxy Compounds In The Low Earth Orbit Environment, Jessica Miriam Piness

Dissertations

Low Earth orbit presents many hazards for composites including atomic oxygen, UV radiation, thermal cycling, micrometeoroids, and high energy protons. Atomic oxygen and vacuum ultraviolet radiation are of concern for space-bound polymeric materials as they degrade the polymers used as matrices for carbon fiber composites, which are used in satellites and space vehicles due to their high strength to weight ratios. Epoxy-amine thermosets comprise a common class of matrix due to processability and good thermal attributes. Polyhedral oligomeric silsesquioxanes (POSS) have shown the ability to reduce erosion in polyimides, polyurethanes, and other polymers when exposed to atomic oxygen. The POSS …

Polyisobutylene Telechelic Prepolymers By In Situ End-Quenching And Post-Polymerization Modifications, Bin Yang

Dissertations

This volume focuses on the development of telechelic polyisobutylene (PIB) prepolymers by combining end-capping of living carbocationic polymerization of isobutylene (IB) with suitable reactants and post-polymerization modifications. Alkylation kinetics of PIB tert-chloride with alkoxybenzenes using either TiCl₄ or AlCl₃ were investigated. Quantitative para-position end-capped products were only achieved if the alkoxybenzene/AlCl₃ molar ratio was greater than unity; while no such molar ratio is required for TiCl₄, but the alkylation rate was slower than AlCl₃ under the same conditions. Photopolymerization kinetics analysis of PIB triphenol tri(meth)acrylates with low and high M_ns, …

Effect Of Chain Rigidity On Network Architecture And Deformation Behavior Of Glassy Polymer Networks, Kyler Reser Knowles

Dissertations

Processing carbon fiber composite laminates creates molecular-level strains in the thermoset matrix upon curing and cooling which can lead to failures such as geometry deformations, micro-cracking, and other issues. It is known strain creation is attributed to the significant volume and physical state changes undergone by the polymer matrix throughout the curing process, though storage and relaxation of cure-induced strains remain poorly understood. This dissertation establishes two approaches to address the issue. The first establishes testing methods to simultaneously measure key volumetric properties of a carbon fiber composite laminate and its polymer matrix. The second approach considers the rigidity of …

Engaging Children In Engineering Design Through The World Of Quadcopters, Greg J. Strimel, Scott R. Bartholomew, Eunhye Kim

Faculty Publications

The interest in engineering education for K-12 students has been rising (Carr, Bennett IV, & Strobel, 2012; Strimel, Grubbs, & Wells, 2016), and the importance of engineering education is discussed as early as the elementary school level (Hegedus, 2014). Petroski (2003) claims that children are ready to learn engineering because their play activities are similar to engineering and design activities, such as making, moving, and rearranging things. Studies have examined how elementary school students perceive engineering or engineers (Cunningham, Lachapelle, & Lindgren-Streicher 2005) and found that elementary-aged students associated engineering with repairing, installing, driving, constructing, and improving machines and devices. …

Performance Testing And Analysis Of Synchronous Reluctance Motor Utilizing Dual-Phase Magnetic Material, Patel B. Reddy, Ayman M. El-Refaie, Min Zou, Di Pan, James P. Alexander, Nidhishri Tapadia, Kevin Grace, Kum-Kang Huh, Frank Johnson

Electrical and Computer Engineering Faculty Research and Publications

While interior permanent magnet (1PM) machines have been considered the state-of-the art for traction motors, synchronous reluctance (SynRel) motors with advanced materials can provide a competitive alternative. 1PM machines typically utilize Neodymium 1ron Boron (NdFeB) permanent magnets, which pose an issue in terms of price, sustainability, demagnetization at higher operating temperatures, and uncontrolled generation. On the other hand, SynRel machines do not contain any magnets and are free from these issues. However, the absence of magnets as well the presence of bridges and centerposts limit the flux-weakening capability of a SynRel machine and limit the achievable constant power speed ratio …

Designing The Technological World Through Biomimicry, Emily Yoshikawa, Greg J. Strimel, Scott R. Bartholomew

Faculty Publications

Scientific discoveries are a driver for advancing our technological world (ITEA/ITEEA; 2000/2002/2007). As more knowledge is acquired through scientific inquiry, people can better design and develop technological inventions and innovations (Knowles, Kelley, & Hurd, 2016). In turn, these novel technologies can aid in making new scientific discoveries, thus driving an ongoing cycle of technological advancement. However, in the process of designing and advancing our technological world, people can turn to the study of life and its phenomena to inspire and inform their designs. Nature is functional as well as beautiful. As we study the phenomena or functions of living organisms …

Optimization Under Uncertainty For Wake Steering Strategies, Julian Quick, Jennifer Annoni, Ryan King, Katherine Dykes, Paul Fleming, Andrew Ning

Faculty Publications

Wind turbines in a wind power plant experience significant power losses because of aerodynamic interactions between turbines. One control strategy to reduce these losses is known as 'wake steering,' in which upstream turbines are yawed to direct wakes away from downstream turbines. Previous wake steering research has assumed perfect information, however, there can be significant uncertainty in many aspects of the problem, including wind inflow and various turbine measurements. Uncertainty has significant implications for performance of wake steering strategies. Consequently, the authors formulate and solve an optimization under uncertainty (OUU) problem for finding optimal wake steering strategies in the presence …

A Framework For Post-Stroke Quality Of Life Prediction Using Structured Prediction, Andrew Hines, John D. Kelleher

Conference papers

This paper presents a conceptual model that relates Quality of Life to the established Quality of Experience formation process. It uses concepts developed by the Quality of Experience community to propose an adapted framework for developing predictive models for Quality of Life. A mapping of common factors that can be applied to health related quality of life is proposed and practical challenges for modelling and applications are presented and discussed. The process of identifying and categorising factors and features is illustrated using stroke patient treatment as an example use case.

Objective Assessment Of Perceptual Audio Quality Using Visqolaudio, Colm Sloan, Damien Kelly, Naomi Harte, Anil C. Kokaram, Andrew Hines

Conference papers

Digital audio broadcasting services transmit substantial amounts of data that is encoded to minimize bandwidth whilst maximizing user quality of experience. Many large service providers continually alter codecs to improve the encoding process. Performing subjective tests to validate each codec alteration would be impractical, necessitating the use of objective perceptual audio quality models. This paper evaluates the quality scores from ViSQOLAudio, an objective perceptual audio quality model, against the quality scores of PEAQ, POLQA, and PEMO-Q on three datasets containing fullband audio encoded with a variety of codecs and bitrates. The results show that ViSQOLAudio was more accurate than all …

Novel Complementary Metasurfaces For The Orbital Angular Momentum Generation, Menglin L.N. Chen, Li Jun Jiang, Wei E.I. Sha

Electrical and Computer Engineering Faculty Research & Creative Works

Besides amplitude, phase and polarization, wavefront is an important property of electromagnetic (EM) waves. EM waves with twisted wavefronts are known to carry orbital angular momentum (OAM). In this paper, a complementary-type metasurface is proposed to generate an OAM beam at microwave regime. Two metasurfaces that can produce OAM of order 2 and 4 are designed. By using our novel design methods, which are based on circuit model and dyadic Green's function, a high conversion efficiency has been achieved with a very low profile.

Intensity Control Of Individual Dbd Plasma Filament. I. Experiment With A Needle Electrode, M. C. Paliwoda, J. L. Rovey

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Filamentary volume dielectric barrier discharge (DBD) produces patterned plasma structures that are currently being explored for reconfigurable metamaterial applications. In this work, the presence and intensity of a single filament (within an array of filaments) are controlled by biasing a low voltage needle electrode by less than 7% of the driving voltage. The current, voltage, and time-averaged normalized light intensity were measured while varying the needle voltage through self-biasing resistors. For a 7.5 kV, 3.2 kHz DBD in air, the needle-controlled filament intensity varies from 80% to 0% of the light intensity of surrounding filaments. When the biased voltage prevents …

Intensity Control Of Individual Dbd Plasma Filament. Ii. Fundamental Physical Mechanism, M. C. Paliwoda, J. L. Rovey

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Filamentary volume dielectric barrier discharge (DBD) produces patterned plasma structures that are currently being explored for reconfigurable metamaterial applications. Previous work has demonstrated control of the presence and intensity of a single DBD plasma filament (within an array of filaments) by biasing a low voltage needle electrode. The results were attributed to redistributed charge inside the DBD due to the modified electric field created by the needle electrode. In the present work, results from a 3D electrodynamic field simulation bolster this argument. Results show that increasing needle bias voltage causes changes in the transverse electric field structure, resulting in redistribution …

Investigating Process-Structure Relations Of Zno Nanofiber Via Electrospinning Method, Ehsan Ghafari, Yining Feng, Yao Liu, Ian T. Ferguson, Na Lu

Electrical and Computer Engineering Faculty Research & Creative Works

1D ZnO nanofibers were fabricated in this study using the electrospinning method through sol-gel approach. The effects of fabrication processing parameters on the nanofibers size have been systematically investigated. The higher concentration of the polymer resulted in a broader distribution of the nanofibers diameter due to non-uniform ejection of the fluid jet. The results indicated that an increase in annealing temperature resulted in a lower diameter size and more uniformity of the nanofiber due to decomposition of PVA. The DSC result confirms that an annealing temperature higher than 480 °C is required to remove the PVA and fully decompose the …

Multi-Objective Dynamic Economic Dispatch With Demand Side Management Of Residential Loads And Electric Vehicles, Mohammad Rasoul Narimani, Fnu Maigha, Jhi-Young Joo, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a multi-objective optimization method based on the normal boundary intersection is proposed to solve the dynamic economic dispatch with demand side management of individual residential loads and electric vehicles. The proposed approach specifically addresses consumer comfort through acceptable appliance deferral times and electric vehicle charging requirements. The multi-objectives of minimizing generation costs, emissions, and energy loss in the system are balanced in a Pareto front approach in which a fuzzy decision making method has been implemented to find the best compromise solution based on desired system operating conditions. The normal boundary intersection method is described and validated.

Infrared Metasurfaces Created With Off-Normal Incidence Microsphere Photolithography, Chuang Qu, Edward C. Kinzel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Fabricating metasurfaces over large areas at low costs remains a critical challenge to their practical implementation. This paper reports on the use of microsphere photolithography (MPL) to create infrared metasurfaces by changing the angle-of-incidence of the illumination to steer the photonic jet. The displacement of the photonic jet is shown to scale with the diameter of the microsphere while the exposure dose scales with the square of the microsphere diameter. This process is robust in the presence of local defects in the microsphere lattice. The paper demonstrates patterning split ring resonators and tripole based metasurfaces using MPL, which are fabricated …

Durability Of Glass Fiber-Reinforced Polymer Bars In Seawater-Contaminated Concrete, Abdelrahman A. E. Alsallamin

Theses

This research aims to investigate the durability performance and microstructure characteristics of two different types of glass fiber-reinforced polymer (GFRP) bars in severe environment. GFRP bars encased in seawater-contaminated concrete were immersed in tap water for 5, 10, and 15 months at temperatures of 20, 40, and 60°C. Half of the specimens were conditioned under a sustained load of 25% of their ultimate strength whereas the other half was conditioned without load. Following conditioning, the GFRP bars were retrieved then tested to failure under uniaxial tension. Microstructure analysis was performed by employing differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) …

Evaluation Of Electrocoagulation For Chloride And Ammonium Removal From The Reject Brine Effluent Pretreated By Solvay Process, Miada Abubaker Ali

Theses

Excessive use of desalination, due to the increase in freshwater demand, results in large productions of reject brine. Therefore, the development of an efficient treatment process of the reject brine becomes vital. The Solvay process is one of the main treatment technologies, wherein NH₃ is introduced to convert soluble Na⁺ into insoluble NaHCO₃. However, in this process, Cl^- is not removed and NH₄⁺ is introduced, and therefore electrocoagulation has been proposed for their removal. The experiment was designed using Minitab with different initial concentrations of chloride (7400 – 32600 mg/l), current densities (0.033 …

Cost-Effective Monitoring Of Railroad Bridge Performance, Jose Alberto Gomez Romero Salazar

Civil Engineering ETDs

The railroad network carries 40 % of the freight in the US. Railroad bridges are the most critical part of the network and they need to be properly maintained for safety of operations. Railroad managers need to inspect the bridges in order to assess their structural condition. Railroad managers are interested in measuring displacements under train crossing events to prioritize their bridge management and safety decisions. However, bridge displacements are difficult to collect in the field, because they require a fixed reference from where to measure. Accelerations can be used to estimate dynamic displacements but to this date, the pseudo-static …

Common Treatments And Procedures Used For Fractures Of The Distal Radius And Scaphoid: A Review, Basel A. Khader, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The distal radius and the scaphoid are the most commonly injured carpal bones among both active adults and the osteoporotic elderly. The purpose of surgical treatment is to restore form and function to the wrist. Depending on the nature of the fracture, either topical procedures or invasive surgery can be applied. This article critiques the treatments currently used for fixation of wrist fractures in order to drive the development of new materials to improve patient outcomes.

Dermal Uptake Of Phthalates From Clothing: Comparison Of Model To Human Participant Results, Glenn Morrison, C. J. Weschler, G. Bekö

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this research, we extend a model of transdermal uptake of phthalates to include a layer of clothing. When compared with experimental results, this model better estimates dermal uptake of diethyl phthalate and di-n-butyl phthalate (DnBP) than a previous model. The model predictions are consistent with the observation that previously exposed clothing can increase dermal uptake over that observed in bare-skin participants for the same exposure air concentrations. The model predicts that dermal uptake from clothing of DnBP is a substantial fraction of total uptake from all sources of exposure. For compounds that have high dermal permeability coefficients, dermal uptake …

The Role Of Ceramic And Glass Science Research In Meeting Societal Challenges: Report From An Nsf-Sponsored Workshop, Katherine T. Faber, Tewodros Asefa, Monika Backhaus-Ricoult, Richard K. Brow, Julie Y. Chan, Shen Dillon, William Fahrenholtz, For Full List Of Authors, See Publisher's Website.

Materials Science and Engineering Faculty Research & Creative Works

Under the sponsorship of the U.S. National Science Foundation, a workshop on emerging research opportunities in ceramic and glass science was held in September 2016. Reported here are proceedings of the workshop. The report details eight challenges identified through workshop discussions: Ceramic processing: Programmable design and assembly; The defect genome: Understanding, characterizing, and predicting defects across time and length scales; Functionalizing defects for unprecedented properties; Ceramic flatlands: Defining structure-property relations in free-standing, supported, and confined two-dimensional ceramics; Ceramics in the extreme: Discovery and design strategies; Ceramics in the extreme: Behavior of multimaterial systems; Understanding and exploiting glasses and melts under …

Sparse Coding On Stereo Video For Object Detection, Sheng Y. Lundquist, Melanie Mitchell, Garrett T. Kenyon

Computer Science Faculty Publications and Presentations

Deep Convolutional Neural Networks (DCNN) require millions of labeled training examples for image classification and object detection tasks, which restrict these models to domains where such a dataset is available. We explore the use of unsupervised sparse coding applied to stereo-video data to help alleviate the need for large amounts of labeled data. In this paper, we show that unsupervised sparse coding is able to learn disparity and motion sensitive basis functions when exposed to unlabeled stereo-video data. Additionally, we show that a DCNN that incorporates unsupervised learning exhibits better performance than fully supervised networks. Furthermore, finding a sparse representation …

The Aerodynamic Effects On Flight Patterns And The Evolutionary Changes In Pterosaurs, Johnathan D. Talik

Maseeh Summer Undergraduate Research Experience

Early pterosaurs were the first vertebrates to achieve powered flight, and remained small-to-medium sized from the Triassic Period to the end of the Jurassic Period. During that interval, lasting from 210 million years ago to 66 million years ago, pterosaurs underwent a notable changes at the end of the Jurassic Period and through the Cretaceous Period. They were abruptly replaced by much larger forms, characterized by great size and peculiar head ornamentation, among other unique and notable morphological features. While many different explanations theorize why and how the features of the pterosaurs changed over the Cretaceous Period, the aerodynamic influences …

Deposition Velocity Dependence On Urban Morphology, Rawand Muzafar Rasheed

Maseeh Summer Undergraduate Research Experience

Understanding the interactions between the atmospheric boundary layer and urban structures provides insights into emerging problems such as green building design as well as dispersion and deposition of pollutants on urban structures. Characterization of deposition velocity dependence through the naphthalene sublimation method on model urban structures is conducted herein where the analogous fundamental transport mechanisms of momentum and mass transport is obtained via mass of naphthalene transferred. Via wind tunnel experiments, results show that deposition velocity of naphthalene from urban structures increases with increased number of urban structures ahead of the point of investigation. This is attributed to the wakes …

Narratives Of Marginalized Cyclists: Understanding Obstacles To Utilitarian Cycling Among Women And Minorities In Portland, Or, Amy Lubitow

TREC Final Reports

Research has demonstrated that everyday or utilitarian forms of cycling are most likely to generate positive population-level health impacts (Garrard et al., 2012), yet significant deterrents to routine cycling remain, particularly for women and minorities. The primary aim of this project was to conduct a qualitative interview study that generated rich, narrative data regarding obstacles to routine or utilitarian cycling for women and minorities who already see biking as a viable form of transit, but who make relatively few bike trips. A secondary aim of the project was to develop a set of specific interventions that have the potential to …

Peer-To-Peer Carsharing: Short-Term Effects On Travel Behavior In Portland, Or, Jennifer Dill, Nathan Mcneil, Steven Howland

TREC Final Reports

Peer-to-peer (P2P) carsharing is a relatively new concept in the U.S. Enabled by recent internet and mobile technology development, P2P carsharing generally involves a facilitating company connecting private vehicle owners to people who are interested in renting a vehicle. P2P carsharing has many things in common with business-to-consumer (B2C) carsharing services. Consumers join the service to rent vehicles on a short-term basis from locations dispersed throughout a certain area. Both services may allow households to reduce their private car ownership. However, P2P carsharing differs substantially from other models in that there are two distinct sets of consumers: those who rent …

Evaluating The Distributional Effects Of Regional Transportation Plans And Projects, Kristine Williams, Aaron Golub

TREC Final Reports

Metropolitan planning organizations (MPOs) have long been required to consider the equity implications of their regional transportation plans and processes. Funded by the National Institute for Transportation and Communities, this research aims to provide additional guidance to MPOs on how to evaluate distributional equity in regional plans and projects. The report begins with an overview of federal requirements related to equity in transportation planning. We then synthesize contemporary methods for measuring transportation equity and the distributional effects of plans and projects from a review of the literature and MPO plans and studies. The report concludes with exploratory case studies of …

Inertial And Time-Of-Arrival Ranging Sensor Fusion, Paul Vasilyeav, Sean Pearson, Mahmoud El-Gohary, Mateo Aboy, James Mcnames

Electrical and Computer Engineering Faculty Publications and Presentations

Wearable devices with embedded kinematic sensors including triaxial accelerometers, gyroscopes, and magnetometers are becoming widely used in applications for tracking human movement in domains that include sports, motion gaming, medicine, and wellness. The kinematic sensors can be used to estimate orientation, but can only estimate changes in position over short periods of time. We developed a prototype sensor that includes ultra wideband ranging sensors and kinematic sensors to determine the feasibility of fusing the two sensor technologies to estimate both orientation and position. We used a state space model and applied the unscented Kalman filter to fuse the sensor information. …

Flux Focusing Axial Magnetic Gear, Robert J. Rutherford

Maseeh Summer Undergraduate Research Experience

Power transmission is traditionally achieved with a mechanical gear. These gears require maintenance, cause vibration, and have no overload protection. Magnetic gears (MGs) offer an innovative solution to these drawbacks as they do not require regular maintenance, have no need for lubrication, create very little acoustic noise, have built in overload protection and as a result of these advantages, have a longer lifetime of operation. The flux focusing axial magnetic gear (FFAMG) was assembled for future testing of power transmission, conversion, and generation applications.

Gears are used to transmit power by converting low speed-high torque rotary motion into high speed-low …

Jet Bounce In Low Gravity, Caleb Turner

Maseeh Summer Undergraduate Research Experience

Liquid jets rebound (‘bounce’) from superhydrophobic surfaces when they impinge at oblique angles. We call this interesting phenomena ‘jet bounce’ and in this work we investigate the phenomena at large length scales in a reduced gravitational environment. For example, for water at Reynolds numbers 0 < Re < 3500 and surface normal Weber numbers 0 < We < 60 we characterize the response of the jets on the hydrophobic surface in the brief 2.1s micro-gravity environment achieved using a drop tower. It is observed that by varying jet velocity, flow rate, jet diameter, and incident angle we observe up to four distinct regimes of behavior. The various regimes may be targeted for specific applications and we demonstrate a variety of unique jet bounce behaviors for applications such as no-touch, no-contact fluid-thermal transport for spacecraft unit operations such as contaminated water processing, device cooling, and cryogenic fluids transport and management.

Stable jet bounce from small diameter jet ≈ 1 mm and low impact angle. Characterizing Reynolds number ≈ 900 and normal Weber number ≤ 10 allow jet bounce to rebound in non-destructive behavior.