Engineering Commons^™

Evaluation Of Metaverse Traffic Safety Implementations Using Fuzzy Einstein Based Logarithmic Methodology Of Additive Weights And Topsis Method, Muhammet Deveci, Dragan Pamucar, Ilgin Gokasar, Mario Köppen, Brij B. Gupta, Tugrul Daim

Engineering and Technology Management Faculty Publications and Presentations

As the Metaverse’s popularity grows, its effect on everyday problems is beginning to be discussed. The upcoming Metaverse world will influence the transportation system as cross-border lines blur due to rapid globalization. The purpose of this paper is to investigate the capabilities of the Metaverse and its alternatives to traffic safety, as well as to prioritize its advantages. The case study is based on a densely populated metropolis with an extensive education system. The city’s decision-makers will have to weigh the pros and cons of the Metaverse’s effect on traffic safety. To illustrate the complex forces that drive the decision-making …

An Examination Of The Stiffness Terms Needed To Model The Dynamics Of An Eddy Current Based Maglev Vehicle, Colton W. Bruce, Jonathan Bird

Electrical and Computer Engineering Faculty Publications and Presentations

This paper re-examines the basis for each eddy current stiffness term computed from prior published steady-state eddy current models. The paper corrects prior analysis work by confirming, through the use of 2-D and 3-D dynamic finite element analysis modelling, that when a magnetic source is moving over an infinite-wide and infinite-long conductive sheet guideway the steady-state lateral and translational stiffness terms will be zero and only the vertical coupled stiffness terms need to be modelled. Using these observations, a much simplified 6 degrees-of-freedom (DoF) linearized eddy current dynamic force model can be used to compute the steady-state force changes in …

Impacts Of A Cascadia Subduction Zone Earthquake On Water Levels And Wetlands Of The Lower Columbia River And Estuary, M. W. Brand, Heida Diefenderfer, J. E. O’Connor, Amy B. Borde, D. A. Jay, Aqeel Al-Bahadily, M. Mckeon, S. A. Talke

Civil and Environmental Engineering Faculty Publications and Presentations

Subsidence after a subduction zone earthquake can cause major changes in estuarine bathymetry. Here, we quantify the impacts of earthquake-induced subsidence on hydrodynamics and habitat distributions in a major system, the lower Columbia River Estuary, using a hydrodynamic and habitat model. Model results indicate that coseismic subsidence increases tidal range, with the smallest changes at the coast and a maximum increase of ∼10% in a region of topographic convergence. All modeled scenarios reduce intertidal habitat by 24%–25% and shifts ∼93% of estuarine wetlands to lower-elevation habitat bands. Incorporating dynamic effects of tidal change from subsidence yields higher estimates of remaining …

Measurement Of Polycyclic Aromatic Hydrocarbons (Pahs) On Indoor Materials: Method Development, Aurélie Laguerre, Elliott T. Gall

Mechanical and Materials Engineering Faculty Publications and Presentations

Wildfire smoke penetrates indoors, and polycyclic aromatic hydrocarbons (PAHs) in smoke may accumulate on indoor materials. We developed two approaches for measuring PAHs on common indoor materials: (1) solvent-soaked wiping of solid materials (glass and drywall) and (2) direct extraction of porous/fleecy materials (mechanical air filter media and cotton sheets). Samples are extracted by sonication in dichloromethane and analyzed with gas chromatography–mass spectrometry. Extraction recoveries range from 50–83% for surrogate standards and for PAHs recovered from direct application to isopropanol-soaked wipes, in line with prior studies. We evaluate our methods with a total recovery metric, defined as the sampling and …

Gas Metal Arc Welding With Undermatched Filler Wire For Hot-Press-Formed Steel Of 2.0 Gpa Strength: Influence Of Filler Wire Strength And Bead Geometry, Dong-Yoon Kim, Cheolhee Kim, Tae Hyen Lee, Minjung Kang, Junhong Park

Mechanical and Materials Engineering Faculty Publications and Presentations

Commercial welding filler wires have less strength than hot-press-forming (HPF) steels. As the 2.0 GPa-HPF steel sheets have been released, their lap welding characteristics were investigated using gas metal arc welding in this study. The base metal was 1.1 mm-thick 2.0 GPa-HPF steel sheets, and three filler metal wires considered in this study (W540, W920, and W980) had tensile strengths of 540, 920, and 980 MPa, respectively. Gas metal arc welding was performed under a controlled short-circuit mode, and the wire feed speed (WFS) was selected as a process parameter. Tensile-shear test and microscopy were performed to evaluate the joint …

Spheroidization Heat Treatment Conditions With Data Analysis In Medium Carbon Cr-Mo Steel For Ultra High Strength Cold Heading, Yong Deok Jo, Sung Yi, Byoung Lok Jang

Mechanical and Materials Engineering Faculty Publications and Presentations

The degree to which parameters affect the spheroidization heat treatment of steel was calculated by setting the spheroidization heat treatment conditions of Cr-Mo steel and using data analysis such as S/N ratio and ANOVA. After analyzing the transformation temperatures of the steel, A_c1 and A_c3, using a DSC, the conditions were set accordingly. The surface hardness was measured for the conditions and used as an evaluation index. The correlation was analyzed by comparing the spheroidized volume fraction and the surface hardness, and the Pearson correlation coefficient was -0.88, proving that a correlation existed between the two values. …

The Role Of High-Order Anharmonicity And Off-Diagonal Terms In Thermal Conductivity: A Case Study Of Multi-Phase Cspbbr3, Xiangdong Ding, Guimei Zhu, Yi Xia, Jie Ren, Jun Sun, Multiple Additional Authors

Mechanical and Materials Engineering Faculty Publications and Presentations

We investigate the influence of three- and four-phonon scattering, perturbative anharmonic phonon renormalization, and off-diagonal terms of coherent phonons on the thermal conductivity of CsPbBr3 phase change perovskite, by using advanced implementations and first-principles simulations. Our study spans a wide temperature range covering the entire structural spectrum. Notably, we demonstrate that the interactions between acoustic and optical phonons result in contrasting trends of phonon frequency shifts for the high-lying optical phonons in orthorhombic and cubic CsPbBr3 as temperature varies. Our findings highlight the significance of wavelike tunneling of coherent phonons in ultralow and glasslike thermal conductivity in halide perovskites.

Anomalous Lattice Thermal Conductivity Driven By All-Scale Electron-Phonon Scattering In Bulk Semiconductors, Z. Z. Zhou, Y. C. Yan, X. L. Yang, Yi Xia, G. Y. Wang, X. Lu, X. Y. Zhou

Mechanical and Materials Engineering Faculty Publications and Presentations

Electron-phonon coupling (EPC) has been broadly considered to govern the charge transport in solids, whereas its effect on thermal conductivity, especially for semiconductors at ambient temperatures, is a widely debated issue in condensed-matter physics. Employing state-of-the-art first-principles calculations to quantify all the possible scattering factors, we show the dominant role of EPC in phonon transport of n-doped GaSb, which yields an unprecedented reduction of lattice thermal conductivity and triggers anomalous temperature-independent behavior. The significant EPC impact hinges on the joint effect of multiple conduction pockets, large EPC strength, and bunched heat-carrying acoustic branches, provoking strong electron-phonon scattering to surpass the …

A Novel Deep Learning, Camera, And Sensorbased System For Enforcing Hand Hygiene Compliance In Healthcare Facilities, Samyak Shrimali, Christof Teuscher

Electrical and Computer Engineering Faculty Publications and Presentations

Hospital-acquired infections are a major cause of death worldwide, and poor hand hygiene compliance is a primary reason for their spread. This paper proposes an artificial intelligence, microcontroller, and sensor-based system that monitors and improves staff hand hygiene compliance at various critical points in a hospital. The system uses a Convolutional Neural Network (CNN) to detect and track if staff have followed the WHO hand rub/hand wash guidelines at alcohol dispensers, hospital sinks, and patient beds. The system also uses RFID tags, vibration motors, LEDs, and a central server to identify staff, alert them of their cleaning requirements, monitor their …

Damage Tracking In Laboratory Reinforced Concrete Bridge Columns Under Reverse-Cyclic Loading Using Fusion-Based Imaging, Sina Mehdinia, A K M Golam Murtuz, Thomas Schumacher, Peter Dusicka

Civil and Environmental Engineering Faculty Publications and Presentations

Fusion-based imaging using ground-penetrating radar (GPR) and ultrasonic echo array (UEA) was employed to track damage progression in the columns of two full-scale reinforced concrete (RC) bridge column-footing subassembly laboratory specimens. The specimens had different lap-splice detailing and were subjected to reverse-cyclic lateral loading simulating a subduction zone earthquake. GPR and UEA scans were performed on the east and west faces of the columns at select ductility levels. Reconstructed images were obtained using the extended total focusing method (XTFM) and fused using a wavelet-based technique. Composite images of each column's interior were created by merging the images from both sides. …

The Networked Nitrous Node: A Low-Power Field-Deployable Cots-Based N2o Gas Sensor Platform, Ronaldo Leon, Wenyu Bi, Eyal Eynis, Travis Johnson, Wei Yan, David C. Burnett, John M. Acken

Electrical and Computer Engineering Faculty Publications and Presentations

We present a wireless nitrous oxide (N 2 O) gas sensor system consisting of a commercial high-current infrared N 2 O sensor wrapped in a “smart” sensor framework to make it suitable for battery-powered deployment. This framework consists of wireless mesh networking, data storage, additional environmental sensors, and a gas sensor power control circuit managed by a central microcontroller. The N 2 O sensor is the first order consumer of power and sampling N 2 O at approximately ten minute intervals yields an estimated system lifetime of 63 days when using four 18650 Li-ion batteries. The node stores data locally …

When Less Is More: How Increasing The Complexity Of Machine Learning Strategies For Geothermal Energy Assessments May Not Lead Toward Better Estimates, Stanley P. Mordensky, John Lipor, Jacob Deangelo, Erick R. Burns, Cary R. Lindsey

Electrical and Computer Engineering Faculty Publications and Presentations

Previous moderate- and high-temperature geothermal resource assessments of the western United States utilized data-driven methods and expert decisions to estimate resource favorability. Although expert decisions can add confidence to the modeling process by ensuring reasonable models are employed, expert decisions also introduce human and, thereby, model bias. This bias can present a source of error that reduces the predictive performance of the models and confidence in the resulting resource estimates.

Our study aims to develop robust data-driven methods with the goals of reducing bias and improving predictive ability. We present and compare nine favorability maps for geothermal resources in the …

Self-Assembly Of Exfoliated Graphene Flakes As Anticorrosive Coatings For Additive Manufactured Steels, Kaleb Hood, Wen Qian, Savannah Krupa, Annie Dao, Sarah Ahmed, Samuel Olson, Jun Jiao, Multiple Additional Authors

Mechanical and Materials Engineering Faculty Publications and Presentations

This study demonstrates the feasibility of using liquid exfoliation of expandable graphite into multilayer exfoliated graphene flakes (EGFs) to form a self-assembled thin film on an air–water interface. The film can coat the surface of additive manufactured (AM) steel substrates to enhance surface properties, specifically AM 316 stainless-steel (AM316), AM 8620 steel (AM8620), and samples of the same alloys made by conventional manufacturing (CM) processes. Liquid exfoliation offers a high yield route for an EGF coating that can cover up to 95% of the sample surface with a single application. The thin, flexible EGFs can coat a rough AM metal …

Flow Development And Entrainment In Turbulent Particle-Laden Jets, Laura K. Shannon, Bianca Viggiano, Raúl Bayoán Cal, L. G. Mastin, Alexa R. Van Eaton, Stephen Solovitz

Mechanical and Materials Engineering Faculty Publications and Presentations

Explosive eruptions expel volcanic gases and particles at high pressures and velocities. Within this multiphase fluid, small ash particles affect the flow dynamics, impacting mixing, entrainment, turbulence, and aggregation. To examine the role of turbulent particle behavior, we conducted an analogue experiment using a particle-laden jet. We used compressed air as the carrier fluid, considering turbulent conditions at Reynolds numbers from approximately 5,000 to 20,000. Two different particles were examined: 14-μm diameter solid nickel spheres and 13-μm diameter hollow glass spheres. These resulted in Stokes numbers between 1 and 35 based on the convective scale. The particle mass percentage in …

Direct Spectroscopic Observation Of Cross-Plane Heat Transfer In A Two-Dimensional Van Der Waals Heterostructure, Du Chen, Matthieu Fortin-Deschênes, Yuchen Lou, Huiju Lee, Kenji Watanabe, Takaaki Taniguchi, Fengnian Xia, Peijun Guo, Multiple Additional Authors

Mechanical and Materials Engineering Faculty Publications and Presentations

Two-dimensional (2D) transition metal chalcogenides (TMDs) have drawn significant attention in recent years due to their extraordinary optical and electronic properties. As heat transfer plays an important role in device performance, various methods such as optothermal Raman spectroscopy and time-domain thermoreflectance have been developed to measure the thermal conductivity and interfacial thermal conductance in 2D van der Waals (vdW) heterostructures. Here, we employ the vibrational-pump-visible-probe (VPVP) spectroscopy to directly visualize the heat transfer process in a heterostructure of multilayer h-BN and monolayer WS2. Following an impulsive vibrational excitation of h-BN in the mid-infrared, we probe the heat transfer …

A Unified Understanding Of Minimum Lattice Thermal Conductivity, Yi Xia, Dale Gaines, Jiangang He, Koushik Pal, Zhi Li, Mercouri G. Kanatzidis, Vidvuds Ozolinš, Chris Wolverton

Mechanical and Materials Engineering Faculty Publications and Presentations

We propose a first-principles model of minimum lattice thermal conductivity based on a unified theoretical treatment of thermal transport in crystals and glasses.

A Pwm Method For Reducing Dv/Dt And Switching Losses In Two-Stage Power Converters, Mahima Gupta, Abhijeet Prem

Electrical and Computer Engineering Faculty Publications and Presentations

Today's semiconductor devices are accompanied by high switching frequencies (> kilo-hertz) and small transition times (< micro-seconds). Such fast transition times are accompanied by undesirable effects such as voltage overshoots at the load terminals, ground leakage currents, wide-band electromagnetic noise, etc. With the advent of wide band-gap devices, several applications are moving towards higher switching frequency operation with at-least an order of magnitude reduction in transition times. While these characteristics are considered necessary to break the next-generation barriers in power density, efficiency and applicability, the undesirable effects due to faster transitions are expected to present obstacles. This work proposes a PWM approach to modify the shape of the switching voltages to overcome the disadvantages of the fast transition times without any increase in switching losses. In fact, several of the switching transitions feature ZVS operation, resulting in reduced switching losses. The paper discusses the analytical details of the approach using a simple DC-DC boost-buck converter and extends it to a DC to three-phase AC converter using the principles of space vector modulation. The paper presents detailed simulation and comparative results in terms of voltage over-shoots over long cables, loss calculations and electromagnetic noise. Results from a laboratory-scale working prototype confirm the benefits of the proposed approach in terms of EMI and loss reduction.

Global Water Level Variability Observed After The Hunga Tonga-Hunga Ha’Apai Volcanic Tsunami Of 2022, Adam Thomas Devlin, David A. Jay, Stefan Talke, Jiayi Pan

Civil and Environmental Engineering Faculty Publications and Presentations

The eruption of the Hunga Tonga-Hunga Ha'apai volcano on 15 January 2022 provided a rare opportunity to understand global tsunami impacts of explosive volcanism and to evaluate future hazards, including dangers from “volcanic meteotsunamis” (VMTs) induced by the atmospheric shock waves that followed the eruption. The propagation of the volcanic and marine tsunamis was analyzed using globally distributed 1 min measurements of air pressure and water level (WL) (from both tide gauges and deep-water buoys). The marine tsunami propagated primarily throughout the Pacific, reaching nearly 2 m at some locations, though most Pacific locations recorded maximums lower than 1 m. …

Experimental Evaluations Of The Impact Of An Additive Oxidizing Electronic Air Cleaner On Particles And Gases, Yicheng Zeng, Aurélie Laguerre, Elliott T. Gall, Mohammad Heidarinejad, Brent Stephens

Mechanical and Materials Engineering Faculty Publications and Presentations

Electronic air cleaning (EAC) technologies have garnered significant attention for use in buildings. Many EAC technologies rely on the addition of reactive constituents to indoor air to react with gas-phase compounds, enhance particle deposition, and/or inactivate microorganisms. However, limited data are available on the efficacy of many EAC technologies and their potential to form chemical byproducts during operation. Here we experimentally evaluate the indoor air quality impacts, specifically targeting particles and gases but not microbial constituents, of a commercially available additive oxidizing EAC that generates positive and negative ions and hydrogen peroxide (H2O2). Tests were conducted in a large unoccupied …

Advanced Industrial Lubricants And Future Development Trends Of Tribo-Systems For Tribological Performance Evaluation, George Totten, Simon C. Tung, Undrakh Mishigdorzhiyn

Mechanical and Materials Engineering Faculty Publications and Presentations

It is possible to solve challenges in the global automotive and manufacturing industries by using a multidisciplinary approach to advanced industrial lubricants, their tribological performance evaluation, and new surface engineering techniques for prospective tribosystems. Three types of approaches are reported in this Special Issue (SI): (1) Advance surface engineering technologies and protective coatings [1–4]; (2) Multipurpose lubricants with nano-additives for better performance [5–8]; (3) Oil degradation simulation thermo-oxidative ageing and dynamic degradation processes [9–12].

Detecting Fast Frequency Events In Power System: Development And Comparison Of Two Methods, Hussain A. Alghamdi, Midrar Adham, Umar Farooq, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

In power systems, frequency deviation from nominal value can occur due to reasons such as loss of generation, loss of load, or major faults in the grid. Such frequency fluctuations can lead to serious subsequent outages and damages to both end-user and utility equipment. Therefore, a proper frequency deviation detection methodology must be in place to effectively identify frequency events in a timely manner. This manuscript provides a comparative analysis between two frequency deviation detection algorithms. One is based on signal processing and statistical analysis. The other is a regression-based algorithm. Both of these algorithms have multiple adjustable parameters, making …

Warming Of The Columbia River, 1853 To 2018, Malia Hanae Scott, Stefan Talke, David Jay, Heida Diefenderfer

Civil and Environmental Engineering Faculty Publications and Presentations

Water temperature is a critical ecological indicator; however, few studies have statistically modeled century-scale trends in riverine or estuarine water temperature, or their cause. Here, we recover, digitize, and analyze archival temperature measurements from the 1850s onward to investigate how and why water temperatures in the lower Columbia River are changing. To infill data gaps and explore changes, we develop regression models of daily historical Columbia River water temperature using time-lagged river flow and air temperature as the independent variables. Models were developed for 3 time periods (mid-19 th , mid-20 th , and early 21 st century), using archival …

Droplet Capture In A Fiber Array, Karl Cardin, Christophe Josserand, Raúl Bayoán Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Droplets interacting with fiber arrays is ubiquitous in nature, textiles, microelectromechanical devices, and fog harvesting. The phenomena of droplet impact on an equidistant array of fibers is experimentally investigated. Drop tower tests are performed to characterize the droplet dynamics in the absence of the effects of gravity which could deform fibers and bias equilibrium configurations. Results show that contact line dissipation is largely responsible for arresting the droplet. Additionally, the penetration length is affected by fiber flexibility. A model is developed predicting the droplet penetration dynamics which shows good agreement with experiments.

Trust Model System For The Energy Grid Of Things Network Communications, Narmada Sonali Fernando, Zhongkai Zheng, John M. Acken, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

Network communication is crucial in the Energy Grid of Things (EGoT). Without a network connection, the energy grid becomes just a power grid where the energy resources are available to the customer uni-directionally. A mechanism to analyze and optimize the energy usage of the grid can only happen through a medium, a communications network, that enables information exchange between the grid participants and the service provider. Security implementers of EGoT network communication take extraordinary measures to ensure the safety of the energy grid, a critical infrastructure, as well as the safety and privacy of the grid participants. With the dynamic …

Evolution Of Eddy Viscosity In The Wake Of A Wind Turbine, Luis Martínez-Tossas, Juliaan Bossuyt, Nicholas Hamilton, Raul Bayoan Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

The eddy viscosity hypothesis is a popular method in wind turbine wake modeling for estimating turbulent Reynolds stresses. We document the downstream evolution of eddy viscosity in the wake of a wind turbine from experimental and large-eddy-simulation data.Wake eddy viscosity is isolated from its surroundings by subtracting the inflow profile, and the driving forces are identified in each wake region. Eddy viscosity varies in response to changes in turbine geometry and nacelle misalignment with larger turbines generating stronger velocity gradients and shear stresses. We propose a model for eddy viscosity based on a Rayleigh distribution. Model parameters are obtained from …

Pcl And Dmso2 Composites For Bio-Scaffold Materials, Jae-Won Jang, Kyung-Eun Min, Cheolhee Kim, Chien Wern, Sung Yi

Mechanical and Materials Engineering Faculty Publications and Presentations

Polycaprolactone (PCL) has been one of the most popular biomaterials in tissue engineering due to its relatively low melting temperature, excellent thermal stability, and cost-effectiveness. However, its low cell attraction, low elastic modulus, and long-term degradation time have limited its application in a wide range of scaffold studies. Dimethyl sulfone (DMSO2) is a stable and non-hazardous organosulfur compound with low viscosity and high surface tension. PCL and DMSO2 composites may overcome the limitations of PCL as a biomaterial and tailor the properties of biocomposites. In this study, PCL and DMSO2 composites were investigated as a new bio-scaffold material to increase …

Quantum Algorithm For Mining Frequent Patterns For Association Rule Mining, Abdirahman Alasow, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

Maximum frequent pattern generation from a large database of transactions and items for association rule mining is an important research topic in data mining. Association rule mining aims to discover interesting correlations, frequent patterns, associations, or causal structures between items hidden in a large database. By exploiting quantum computing, we propose an efficient quantum search algorithm design to discover the maximum frequent patterns. We modified Grover’s search algorithm so that a subspace of arbitrary symmetric states is used instead of the whole search space. We presented a novel quantum oracle design that employs a quantum counter to count the maximum …

Gait And Turning Characteristics From Daily Life Increase Ability To Predict Future Falls In People With Parkinson’S Disease, Vrutangkumar Shah, Adam Jagodinsky, James Mcnames, Multiple Additional Authors

Electrical and Computer Engineering Faculty Publications and Presentations

Objectives: To investigate if digital measures of gait (walking and turning) collected passively over a week of daily activities in people with Parkinson’s disease (PD) increases the discriminative ability to predict future falls compared to fall history alone. Methods: We recruited 34 individuals with PD (17 with history of falls and 17 non-fallers), age: 68 ± 6 years, MDS-UPDRS III ON: 31 ± 9. Participants were classified as fallers (at least one fall) or non-fallers based on self-reported falls in past 6 months. Eighty digital measures of gait were derived from 3 inertial sensors (Opal® V2 System) placed on the …

Crack Detection In An Aluminium Oxide Grinding Wheel By Impact Hammer Tests, Yubin Lee, David Turcic, Dan Danks, Chien Wern

Mechanical and Materials Engineering Faculty Publications and Presentations

Grinding is widely used as the last step of the manufacturing process when a good surface finish and precise dimensional tolerances are required. However, if the grinding wheels have cracks, they may lead to a hazardous working environment and produce poor tolerance in machined products. Therefore, grinding wheels should be inspected for cracks before being mounted onto the machine. In this study, a novel method of finding possible internal cracks in the aluminium oxide grinding wheel will be explored by examining the natural frequency and displacement of wheels using an impact hammer testing method. Grinding wheels were cracked into two …

A Representation For Many Player Generalized Divide The Dollar Games, Garrison Greenwood, Daniel Ashlock

Electrical and Computer Engineering Faculty Publications and Presentations

Divide the dollar is a simplified version of a two player bargaining problem game devised by John Nash. The generalized divide the dollar game has n > 2 players. Evolutionary algorithms can be used to evolve individual players for this generalized game but representation—i.e., a genome plus a move or search operator(s)—must be carefully chosen since it affects the search process. This paper proposes an entirely new representation called a demand matrix. Each individual in the evolving population now represents a collection of n players rather than just an individual player. Players use previous outcomes to decide their choices (bids) in …