Engineering Commons^™

Wake Bifurcations Behind Two Circular Disks In Tandem Arrangement, Jianzhi Yang, Xiaowei Wu, Minghou Liu, Changjian Wang, Yuxin Wu, Zhihe Shen

Mechanical and Materials Engineering Faculty Publications and Presentations

The wake bifurcations behind two circular disks in tandem arrangement are investigated through numerical simulations. The separation distance between the disks, S/d, is chosen at 1, 2, 4, and 6, and the Reynolds number, Re, lies in the range of 100 Re 500. The wake dynamics are examined in terms of the flow structures as well as drag and lift coefficient characteristics. Seven main wake regimes are observed in the considered (Re, S/d) space: steady state (SS), Zig-zig (Zz) mode, standing wave mode, periodic state with reflectional symmetry breaking (RSB), periodic state with double-helical (DH) structures shedding, periodic state with …

Augmentative And Alternative Communication Use, Service Delivery Experiences, And Communicative Participation For People With Amyotrophic Lateral Sclerosis, Betts Peters

Dissertations and Theses

People with amyotrophic lateral sclerosis (ALS) often experience changes to their speech, and may use augmentative and alternative communication (AAC) devices and techniques to maintain the ability to communicate. The use of AAC may facilitate the participation of people with ALS in various life situations involving communication. There is limited data in the literature about the AAC approaches currently used by people with ALS, the professional services they receive to support communication, or the effects of AAC on their communicative participation. This dissertation involved a nationwide online survey of people with ALS, and comprises three papers intended to add to …

Observation And Control Of Photoemission And Electric Field Enhancement Of Plasmonic Antennas Through Photoemission Electron Microscopy, Christopher M. Scheffler

Dissertations and Theses

Photoemission electron microscopy (PEEM) is an imaging method which uses electrons excited through the photoelectric effect to characterize a sample surface with nanometer-level resolution. In PEEM, a high intensity laser excites electrons from the surface of the material and electron optics are used to form an image from the intensity and spatial distribution of the photoemission from the sample. The goal of this research was to study and maximize light confinement, which was accomplished using plasmonic nanostructures. Surface plasmons represent oscillations in the electron density of a material and can occur along the transition interface between a metal and a …

How Advances In Low-G Plumbing Enable Space Exploration, Mark M. Weislogel, John Graft, Andrew P. Wollman, Karl Cardin, Logan Torres, J. E. Goodman, J. C. Buchli

Mechanical and Materials Engineering Faculty Publications and Presentations

In many ways, plumbing is essential to life support. In fact, the advance of humankind on Earth is directly linked to the advance of clean, healthy, reliable plumbing solutions. Shouldn’t this also be true for the advancement of humankind in space? Unfortunately, the reliability of even the simplest plumbing element aboard spacecraft is rarely that of its terrestrial counterpart. This state of affairs is due entirely to the near-weightless “low-g” state of orbiting and coast spacecraft. But the combined passive capillary effects of surface tension, wetting, and system geometry in space can be exploited to replace the passive role of …

Multicolor Fluorescence Guided Surgery For Head And Neck Cancer, Dani Szafran-Reeder

University Honors Theses

This project aims to take a novel, NIR nerve-specific fluorophore LGW05-75⁴ and test its compatibility with a tumor-targeting affibody molecule, ABY-029⁶ that has been labeled with IRDye800CW. The overall goal is to show that these two molecules can be co-administered to show the nerves and tumor cells in real-time to better assist surgeons in a full resection while avoiding iatrogenic nerve damage.

Understanding Ch4 Emissions From Compostables: An Exploration Of Local Ch4 Emissions From Landfilled Compostables And The Efficacy Of Emission Mitigation Via Anaerobic Biogas Digestion, Jordan-Yoosuf Aljbour

University Honors Theses

Methane (CH₄) is the second most abundant anthropogenic greenhouse gas within the atmosphere, comprising ~16% of the total anthropogenic greenhouse gas composition on Earth. It has an ~12-year lifetime relative to its eventual oxidation via reaction with tropospheric hydroxyl radicals (OH), and has a 100-year indirect global warming potential (GWP) approximately ranging between 28-36 [Environmental Protection Agency, 2021]. In recent years, the observed average global concentration of atmospheric CH₄ has increased by ~11.0% from 2020 (~15.3 ppb) to 2021 (~17.0 ppb) [Dlugokencky et al., 1994; National Oceanic and Atmospheric Administration, 2022]. With …

An Elastic Recommender Process For Cloud Service Recommendation Scalability, Rui-Dong Qi, Jian-Tao Zhou, Zhuowei Wang, Xiaoyu Song

Electrical and Computer Engineering Faculty Publications and Presentations

Cloud computing services are ubiquitous in society and cloud recommender systems play a crucial role in intelligently selecting services for cloud users. Currently, recommendations are static with low scalability. Only one recommendation list is generated at a time and the recommender strategy in the recommendation cycle is not adjustable. This paper presents a new elastic recommender process (ERP) for cloud users. A Markov model is used to characterize the dynamic relationship between different user states. The ERP generates an elastic recommendation that can be used to dynamically adjust the recommender strategy to meet the user's needs based on their browsing …

Designing A Halbach Rotor Magnetic Gear For A Marine Hydrokinetic Generator, Hossein Baninajar, Sina Modaresahmadi, H. Y. Wong, Jonathan Bird, W. Williams, B. Dechant

Electrical and Computer Engineering Faculty Publications and Presentations

This paper presents the electromagnetic and mechanical design as well as experimental testing results for a 9.5:1 gear ratio, series connected, coaxial magnetic gear (MG) for use in a marine hydrokinetic generator. A 2-D and 3-D magnetostatic finite element analysis (FEA) sizing analysis was also conducted and a torque density comparison between using a nested or series MG typology is presented. To achieve a high torque density a four-segment per pole-pair Halbach rotor assembly with a unique slotted Halbach magnet arrangement was used that enables the Halbach rotor magnets to be more easily assembled, even with dimensional tolerance inaccuracies. A …

Developing An Energy Service Interface Specification, Jaime T. Kolln

Dissertations and Theses

Developing an Energy Service Interface (ESI) specification requires engaging a community of stakeholders including grid operators, Information and Communication Technology implementors, integrators, and finally standards bodies who will define an interface that respects and boundaries of ownership and roles of responsibility in order to activate millions of Distributed Energy Resources for the provision of grid services. By applying Interoperability Maturity Model Criteria and ESI principles to common grid-DER service use cases, the Grid Modernization Lab Consortium team will engage subject matter experts to develop a specification, with an eventual goal of informing development of ESI compliant profiles or standards. The …

Systemic Opportunities To Improve Older Pedestrian Safety: Merging Crash Data Analysis And A Stakeholder Workshop, Jason C. Anderson, Sirisha Kothuri, Christopher M. Monsere, David S. Hurwitz

Civil and Environmental Engineering Faculty Publications and Presentations

This paper presents a framework for improving older pedestrian safety in regard to serious (fatal and incapacitating) crashes, using Oregon as a case study. On review of state and federal practices pertaining to older pedestrian safety, 4 years of crash data identified 112 older (≥ 65 years) pedestrian serious injury crashes. These data were explored for factors that might be addressed systemically using two methods. First, raw frequencies in the crash data were assessed to determine trends and crash-related factors that are overrepresented. Second, a random forest analysis was conducted to determine important variables for predicting older pedestrian serious injury …

Characteristics Of The Wake Of An Inclined Prolate Spheroid In Uniform Shear Flow, Zhe Wang, Jianzhi Yang, Helge I. Andersson, Xiaowei Wu, Yuxin Wu, Liping Wang, Minghou Liu

Mechanical and Materials Engineering Faculty Publications and Presentations

Flow around an inclined 5:2 prolate spheroid with the incidence angle α = 45° is numerically investigated in a uniform shear flow. The Reynolds number based on the inflow center velocity Uc and the volume-equivalent sphere diameter De of the spheroid are considered at Re = 480, 600, 700, and 750. The non-dimensional shear rate K is ranged from 0 to 0.1. Five qualitatively different wake modes are observed, including a new mode characterized by multi-periodic shedding of hairpin vortices with regular rotation of the separation region. In general, the wake transition is suppressed with increasing shear rate. …

Memristors, Memcapacitors And Their Application In Neuromorphic Computing, Nithyakalyani Sampath

Student Research Symposium

Data-intensive computing operations, such as training neural networks, are essential but energy-intensive. Memcapacitance and memristance,which can be described as capacitance and resistance, with “memory”, are properties of semiconductor devices that are observed on the nano-scale. These properties allow for data storage without a constant source of power, leading to hardware which is more energy efficient.

We intend to demonstrate that we can build specialized hardware onto which a neural network can be directly mapped using memristors and memcapacitors, improving the energy efficiency of the network. We will use Simulation Program with Integrated Circuit Emphasis (SPICE) to model our memcapacitor and …

Growing Reservoir Networks Using The Genetic Algorithm Deep Hyperneat, Nancy L. Mackenzie

Student Research Symposium

Typical Artificial Neural Networks (ANNs) have static architectures. The number of nodes and their organization must be chosen and tuned for each task. Choosing these values, or hyperparameters, is a bit of a guessing game, and optimizing must be repeated for each task. If the model is larger than necessary, this leads to more training time and computational cost. The goal of this project is to evolve networks that grow according to the task at hand. By gradually increasing the size and complexity of the network to the extent that the task requires, we will build networks that are more …

Proposed Application For An Entity Component System In An Energy Services Interface, Tylor Slay, Grace B. Spitzer, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

An Entity Component System is a data-oriented architecture originally developed to streamline video game performance. Despite being quite new, Entity Component Systems are relatively well established within the video game industry due to the cutting edge nature of research into performance, especially around graphics. However, Entity Component Systems have not been widely examined or adopted outside of that industry. We propose adopting an Entity Component Systems framework to serve the needs of an Energy Service Interfaces. We examine the needs of an Energy Service Interface, give an overview of open-source Entity Component Systems (ECSs) libraries, examine some preliminary performance results …

Poster: K-Anonymity Applied To The Energy Grid Of Things Distributed Energy Resource Management System, Mohammed Alsaid, Tylor Slay, Nirupama Bulusu, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

The violation of information privacy in Smart Grids can be a significant barrier to customers’ participation. Employing privacy protection models such as K-anonymity in a Smart Grid implementation adds desirable privacy guarantees. This work provides an approach to applying the Mondrian algorithm to ensure data within the system excludes Personally Identifiable Information. Results suggest that a dynamically generated generalization hierarchy minimizes information loss incurred by the anonymization process.

A Hybrid Approach To Improve Flood Forecasting By Combining A Hydrodynamic Flow Model And Artificial Neural Networks, Li Li, Kyong Soo Jun

Civil and Environmental Engineering Faculty Publications and Presentations

Climate change is driving worsening flood events worldwide. In this study, a hybrid approach based on a combination of the optimization of a hydrodynamic model and an error correction modeling that exploit different aspects of the physical system is proposed to improve the forecasting accuracy of flood water levels. In the parameter optimization procedure for the hydrodynamic model, Manning’s roughness coefficients were estimated by considering their spatial distribution and temporal variation in unsteady flow conditions. In the following error correction procedure, the systematic errors of the optimized hydrodynamic model were captured by combining the input variable selection method using partial …

Building A Turbulent Jet: Measuring/Modeling Lagrangian Dispersion, Particle Trajectory Dynamics And Intermittency, Bianca Fontanin Viggiano

Dissertations and Theses

The mechanics of how particles diffuse, interact, eject, etc. within a fluid is applicable to numerous industrial and environmental applications. Unwanted products of combustion, dust contamination of solar panels, pathogen transport during a cough and ejections of particles during volcanic eruptions, are a few examples of flows in which increased knowledge of particle dynamics could result in substantial reduction of negative environmental and economic impacts. To better understand the tendencies of particles within shearing flows (such as jets), an extensive experimental campaign was conducted. Measurements of a turbulent round water jet were performed within an icosahedral tank. Particle tracking velocimetry …

Robust Multi-Period Maximum Coverage Drone Facility Location Problem Considering Coverage Reliability, Darshan Rajesh Chauhan, Avinash Unnikrishnan, Miguel A. Figliozzi, Stephen D. Boyles

Civil and Environmental Engineering Faculty Publications and Presentations

This study proposes a multi-period facility location formulation to maximize coverage while meeting a coverage reliability constraint. The coverage reliability constraint is a chance constraint limiting the probability of failure to maintain the desired service standard, commonly followed by emergency medical services and fire departments. Further, uncertainties in the failure probabilities are incorporated by utilizing robust optimization using polyhedral uncertainty sets, which results in a compact mixed-integer linear program. A case study in the Portland, OR metropolitan area is analyzed for employing unmanned aerial vehicles (UAVs) or drones to deliver defibrillators in the region to combat out-of-hospital cardiac arrests. In …

An Investigation Into Magnetic Gears And Magnetic Springs For Marine Hydrokinetic Power Generators, Hossein Baninajar

Dissertations and Theses

Marine hydrokinetic generators often use mechanical gears to convert the low-speed motion into the high-speed rotary motion that is required for conventional electrical generators. While mechanical gearboxes have a high torque density and can reach high efficiencies, they suffer from serious reliability issues. Recently, magnetic gearing technology has been proposed as a means of making hydrokinetic generators more reliable. As magnetic gears use magnetic field modulation to create speed change, they offer a high reliability, nonfriction, power transmission mechanism that limits the wear to only the bearings and makes the magnetic gears almost maintenance-free. During an over-torque condition, a magnetic …

Financial Analysis Of Meta Platforms Inc, Anurag Yaddanapudi, Kaushik Chaudhary, Saumya Saxena

Engineering and Technology Management Student Projects

Web3.0 is the latest generation of internet, which is about decentralization and democratization, built on blockchain technology, high computer power and high-speed network. Metaverse overlaps with Web3.0 in terms of decentralization and is built on the same base technologies but talks about virtual realities and brings immersive experiences.

This study explores how the web has evolved over the years and analyzes the current market trends of Web3.0. The purpose of the study is to examine the investments made by Meta Platforms Inc. which is one of the market leaders of the Internet industry and provide an in-depth financial analysis by …

Site-Specific Site Response Analysis And Cascadia Subduction Zone Ground Motions Evaluation For A Site Near Portland, Brian Ackerman

Civil and Environmental Engineering Master's Project Reports

Site-specific ground motions, site-specific site response analysis, and development of site-specific acceleration ground spectra at the ground surface was developed per ASCE 7-10 for the Kirkland Renaissance Boardwalk, a site in Vancouver, Washington.

Synthetic broadband ground motions developed specifically for Cascadia Subduction Zone (CSZ) megathrust earthquake were used for site-response analysis. The results of site-specific site response analyses using the strong motions were compared with the results from the 5 motions considered for the ASCE 7-10 procedure. The effect of motion duration and other ground motion intensity measures on the results of the site-specific site response analysis was investigated.

Similar …

Measuring Volatile Emissions From Moss Gametophytes: A Review Of Methodologies And New Applications, Danlyn L. Brennan, Leslie M. Kollar, Scott Kiel, Timea Deakova, Aurélie Laguerre, Stuart F. Mcdaniel, Sarah Eppley, Elliott T. Gall, Todd Rosenstiel

Center for Life in Extreme Environments Publications

Mosses inhabit nearly all terrestrial ecosystems and engage in important interactions with nitrogen-fixing microbes, sperm-dispersing arthropods, and other plants. It is hypothesized that these interactions could be mediated by biogenic volatile organic compounds (BVOCs). Moss BVOCs may play fundamental roles in influencing local ecologies, such as biosphere–atmosphere–hydrosphere communications, physiological and evolutionary dynamics, plant–microbe interactions, and gametophyte stress physiology. Further progress in quantifying the composition, magnitude, and variability of moss BVOC emissions, and their response to environmental drivers and metabolic requirements, is limited by methodological and analytical challenges. We review several sampling techniques with various analytical approaches and describe best practices …

Temporary Housing Alternatives: Economic Analysis, Matt Gillispie, Swapna Kandula, Girija Patil, Juan Vasconez, Jennifer Lynn Zeitouni

Engineering and Technology Management Student Projects

In this report, we are aiming to find the best construction alternative to provide housing to the homeless community of Multnomah County in Oregon. The goal is to identify the most beneficial construction process through an economic analysis. In conjunction with existing projects such as “Safe Rest Villages” that are working on offering services and solutions, the plan is to reduce the county’s houseless population by 50% over a time period of 10 years. The analysis includes gathering data about the community, but also calculating the costs and benefits of three alternatives - 3D Printed houses, tiny homes, and prefabricated …

Cost Analysis For Renewable Energy At Residential Houses In Ca, Karthik Manjunath, Sara Ferdousi, Ahmed Mahdi, Navdeep Singh, Yousra Abusharekh

Engineering and Technology Management Student Projects

Solar energy has been demonstrated to be the most productive and compelling among sustainable power hotspots for home and business use. California has made a concerted effort to boost the integration of renewables into the grid. In 2020, a "solar mandate" went into effect, and in 2022, the California Energy Commission released the draft language for the 2022 building standards. The use of photovoltaic (PV) systems supports the achievement of Sustainable Development Goals (SDGs) – particularly SDG 13 in direct impact – through preserving the environment, reducing the levels of greenhouse gasses (GHGs), and accordingly reducing global warming. Therefore, the …

Effects Of Electrode Negative Pulsing Ratio In Direct Energy Deposition Via Variable-Polarity Cold Metal Transfer Process On The Deposition Behavior And Microstructural Characteristics, Tae Hyun Lee, Cheolhee Kim, Minjung Kang

Mechanical and Materials Engineering Faculty Publications and Presentations

Interest in research on the application of variable-polarity cold metal transfer mode in wire-based direct energy deposition has been growing; particularly popular are investigations into the respective influences of polarity, amplitude of the arc current, and polarity variation sequence on the quality of the final product manufactured via additive manufacturing. The application of the electrode-negative phase is more capable of yielding relatively large droplets and increasing the weight of the deposited material. However, the proportions of the electrode positive phase are typically larger than those of the electrode-negative phase because it maintains arc stability and droplet transfer. This discrepancy has …

Secondary Motions Above A Staggered Multi-Scale Rough Wall, Bianca Viggiano, Juliaan Bossuyt, N. Ali, Johan Meyers, Raul Bayoan Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Wind tunnel experiments were performed to investigate turbulent flow over an array of heterogeneous roughness elements using stereoscopic particle image velocimetry. Nine streamwise planes, covering one periodic cell of a multi-scale roughness element that is arranged in a staggered pattern, are combined to quantify mean flow features and Reynolds stresses. Dispersive stresses, arising from spatial variations in the temporally averaged mean velocity, are also presented. The results highlight that the roughness elements create a large deficit pathway along the surfaces. Outer scaling of the time-averaged streamwise velocity presents features which are nearly independent of the roughness element type, with parameters …

Privacy-Preserving Information Security For The Energy Grid Of Things, Mohammed Alsaid, Nirupama Bulusu, Abdullah Barghouti, N. Sonali Fernando, John M. Acken, Tylor E. Slay, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

Smart grid infrastructure relies on information exchange between multiple actors in order to ensure system reliability. These actors include but are not limited to smart loads, grid control, and energy management technologies. As information exchange between these actors is susceptible to cyber-attacks, security and privacy issues are indispensable to ensure a reliable and stable grid. This position paper proposes a privacy-preserving, trust-augmented secure scheme for a smart grid implementation.

Mass Capacity Analysis Of Stormwater Control Measures Using Synthetic Stormwater With Silica, Organic And Hydrocarbon Constituents, Craig Michael Fairbaugh

Dissertations and Theses

Stormwater control measure (SCM) performance is well studied regarding solids removal; however, analysis of mass loading capacity, long-term performance, and maintenance demands are challenging due to the variability and multiple constituents inherent in urban stormwater. This research examines the long-term water quality performance and sediment mass capacity of two common SCMs: high rate biofiltration (HRBF) and conventional bioretention (BRT). Pollutant removal trials were conducted in a laboratory setting per the New Jersey Department of Environmental Protection (NJDEP) filtration protocol in two phases: the first using inorganic sediment per the NJDEP protocol, the second phase with the addition of organic sediment …

Design And Evaluation Of A Prototype Low-Damage Beam-Column Connection For Mass Timber Moment Frames, Samuel D. Richmann

Civil and Environmental Engineering Master's Project Reports

A moment-resisting, beam-column connection for mass timber moment frames was developed, designed and tested. The design was intended to limit damage to the timber members by creation of a ductile failure mechanism in steel U-shaped flexural plates (UFPs). Using design equations developed by previous research on UFPs by Baird, et al. (2014) as well as accepted design practices from the NDS and AISC, the components were sized to eliminate failure in the timber. The connection was tested using a quasi-static lateral displacement method following the procedure outlined in section K2.4b of AISC 341-16. A vertical load was placed on the …

Modeling Cyanobacteria Vertical Migration, Corina Christina Mae Overman, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

Cyanobacteria often cause harmful algal blooms and release toxic substances that can harm humans and animals. Accurately modeling these phytoplankton is a step towards predicting, preventing, and controlling such blooms. Certain cyanobacteria species are known to migrate vertically in the water column on a daily cycle. Capturing this behavior is one aspect of modeling their dynamics. Previous studies on modeling cyanobacterial vertical migration are reviewed and summarized. Several models of cyanobacteria vertical movement are tested using data from field studies. These models are applied using both continuum and particle-tracking frameworks. Models range in complexity from simple functions of time to …