Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Engineering

Portland State University

Series

Keyword
Publication Year
Publication
File Type

Articles 1 - 30 of 1180

Full-Text Articles in Entire DC Network

Exploring Cybertechnology Standards Through Bibliometrics: Case Of National Institute Of Standards And Technology, Tugrul Daim, Haydar Yalcin, Alain Mermoud, Valentin Mulder Jun 2024

Exploring Cybertechnology Standards Through Bibliometrics: Case Of National Institute Of Standards And Technology, Tugrul Daim, Haydar Yalcin, Alain Mermoud, Valentin Mulder

Engineering and Technology Management Faculty Publications and Presentations

Cyber security is one of the topics that gain importance today. It is necessary to determine the basic components, basic dynamics, and main actors of the Cyber security issue, which is obvious that it will have an impact in many areas from social, social, economic, environmental, and political aspects, as a hot research topic. When the subject literature is examined, it has become a trend-forming research subject followed by institutions and organizations that produce R&D policy, starting from the level of governments. In this study, cybersecurity research is examined in the context of 5 basic cyber security functions specified in …


Supercomputers And Quantum Computing On The Axis Of Cyber Security, Haydar Yalcin, Tugrul Daim, Mahdieh Mokhtari Moughari, Alain Mermoud Jun 2024

Supercomputers And Quantum Computing On The Axis Of Cyber Security, Haydar Yalcin, Tugrul Daim, Mahdieh Mokhtari Moughari, Alain Mermoud

Engineering and Technology Management Faculty Publications and Presentations

Cybersecurity has become a very critical area to address for governments, industry and the academic community. Cyber attacks are on the rise so is research to address the challenges presented by these attacks. Research yields several technological advancements. This paper explores the development of quantum computing and supercomputers within the context of cybersecurity. As many governments and organizations are under the threat of cyber-attacks, it is critical and timely to explore the status of technological development. We use advanced scientometric techniques to disclose the development status and identify the centers of excellence. The research uses bibliometric data of published papers …


Processes For Depositing Functionalized Nanoparticles Upon A Substrate, Erik T. Thostenson, Thomas Schumacher Jun 2024

Processes For Depositing Functionalized Nanoparticles Upon A Substrate, Erik T. Thostenson, Thomas Schumacher

Civil and Environmental Engineering Faculty Publications and Presentations

Processes for depositing functionalized nanoparticles upon a non-conductive substrate are disclosed herein. The processes may include the step of aerosolizing one or more particles into suspension within a gas, each of the one or more particles comprising functionalized nanoparticles having an electric charge. The processes may include the step the step of attracting the one or more particles onto a non-conductive substrate by a static electric charge opposite of the electric charge, wherein at least portions of the non-conductive substrate are having the static electric charge. The processes may include the step of depositing the functionalized nanoparticles onto the non-conductive …


Advanced Acoustic Emission-Based Shm For Concrete Structures: Real-Time, High-Precision Imaging Of Crack Geometry And Damage Sourcetype Using Moment Tensor Inversion, Seyyedmaalek Momeni, Thomas Schumacher, Lindsay Linzer, Brice Lecampion Jun 2024

Advanced Acoustic Emission-Based Shm For Concrete Structures: Real-Time, High-Precision Imaging Of Crack Geometry And Damage Sourcetype Using Moment Tensor Inversion, Seyyedmaalek Momeni, Thomas Schumacher, Lindsay Linzer, Brice Lecampion

Civil and Environmental Engineering Faculty Publications and Presentations

In this paper, we introduce a novel automated and high-precision acoustic emission (AE) monitoring algorithm and the software SIMORGH, which is suitable for structural health monitoring (SHM) of civil structures. Initially developed for laboratory-scale hydraulic fracture monitoring, this core software has been effectively scaled up to meter-level applications and is compatible with heterogeneous media such as concrete. It is designed to work with various standard data formats and is handles both trigger-based and continuous data. We present initial results from implementing this software in the AE monitoring of two 4.88-meter-long concrete beams in a laboratory setting, comparing it with manually …


Investigation Of Piezocone Dissipation Test Interpretation In Clay Accounting For Vertical And Horizontal Porewater Pressure Dissipation With A Large Deformation Axisymmetric Penetration Model, Diane Moug, Andrew Huffman, Jason T. Dejong May 2024

Investigation Of Piezocone Dissipation Test Interpretation In Clay Accounting For Vertical And Horizontal Porewater Pressure Dissipation With A Large Deformation Axisymmetric Penetration Model, Diane Moug, Andrew Huffman, Jason T. Dejong

Civil and Environmental Engineering Faculty Publications and Presentations

The piezocone (CPTu) dissipation test is used to characterize how the applied load from the penetrating cone is distributed between the soil and pore fluid during both penetrometer advancement and when penetration is paused. The coefficient of consolidation is often estimated from CPTu dissipation tests by interpreting the rate of excess porewater pressure (∆u) decay to static conditions during a pause in cone penetration. Most CPTu dissipation test interpretation methods are based on Terzaghi consolidation theory for ∆u dissipation at the cone shoulder (u2 position) or cone face (u1 position) and assume that radial ∆u dissipation dominates the …


Rheological Properties And 3d Printing Behavior Of Pcl And Dmso2 Composites For Bio-Scaffold, Jae-Won Jang, Kyung-Eun Min, Cheolhee Kim, Chien Wern, Sung Yi May 2024

Rheological Properties And 3d Printing Behavior Of Pcl And Dmso2 Composites For Bio-Scaffold, Jae-Won Jang, Kyung-Eun Min, Cheolhee Kim, Chien Wern, Sung Yi

Mechanical and Materials Engineering Faculty Publications and Presentations

The significance of rheology in the context of bio three-dimensional (3D) printing lies in its impact on the printing behavior, which shapes material flow and the layer-by-layer stacking process. The objective of this study is to evaluate the rheological and printing behaviors of polycaprolactone (PCL) and dimethyl sulfone (DMSO2) composites. The rheological properties were examined using a rotational rheometer, employing a frequency sweep test. Simultaneously, the printing behavior was investigated using a material extrusion 3D printer, encompassing varying printing temperatures and pressures. Across the temperature range of 120–140 °C, both PCL and PCL/DMSO2 composites demonstrated liquid-like behavior, …


Artificial Neural Network-Based Modelling For Yield Strength Prediction Of Austenitic Stainless-Steel Welds, Sukil Park, Cheolhee Kim, Namhyun Kang May 2024

Artificial Neural Network-Based Modelling For Yield Strength Prediction Of Austenitic Stainless-Steel Welds, Sukil Park, Cheolhee Kim, Namhyun Kang

Mechanical and Materials Engineering Faculty Publications and Presentations

This study aimed to develop an artificial neural network (ANN) model for predicting the yield strength of a weld metal composed of austenitic stainless steel and compare its performance with that of conventional multiple regression and machine learning models. The input parameters included the chemical composition of the nine effective elements (C, Si, Mn, P, S, Ni, Cr, Mo, and Cu) and the heat input per unit length. The ANN model (comprising five nodes in one hidden layer), which was constructed and trained using 60 data points, yielded an R2 value of 0.94 and a mean average percent error …


Can Smart Supply Chain Bring Agility And Resilience For Enhanced Sustainable Business Performance?, Mahak Sharma, Rose Antony, Ashu Sharma, Tugrul Daim May 2024

Can Smart Supply Chain Bring Agility And Resilience For Enhanced Sustainable Business Performance?, Mahak Sharma, Rose Antony, Ashu Sharma, Tugrul Daim

Engineering and Technology Management Faculty Publications and Presentations

Purpose

Supply chains need to be made viable in this volatile and competitive market, which could be possible through digitalization. This study is an attempt to explore the role of Industry 4.0, smart supply chain, supply chain agility and supply chain resilience on sustainable business performance from the lens of natural resource-based view.

Design/methodology/approach

The study tests the proposed model using a covariance-based structural equation modelling and further investigates the ranking of each construct using the artificial neural networks approach in AMOS and SPSS respectively. A total of 234 respondents selected using purposive sampling aided in capturing the industry practices …


Imaging Of Structural Timber Based On In Situ Radar And Ultrasonic Wave Measurements: A Review Of The State-Of-The-Art, Narges Pahnabi, Thomas Schumacher, Arijit Sinha May 2024

Imaging Of Structural Timber Based On In Situ Radar And Ultrasonic Wave Measurements: A Review Of The State-Of-The-Art, Narges Pahnabi, Thomas Schumacher, Arijit Sinha

Civil and Environmental Engineering Faculty Publications and Presentations

With the rapidly growing interest in using structural timber, a need exists to inspect and assess these structures using non-destructive testing (NDT). This review article summarizes NDT methods for wood inspection. After an overview of the most important NDT methods currently used, a detailed review of Ground Penetrating Radar (GPR) and Ultrasonic Testing (UST) is presented. These two techniques can be applied in situ and produce useful visual representations for quantitative assessments and damage detection. With its commercial availability and portability, GPR can help rapidly identify critical features such as moisture, voids, and metal connectors in wood structures. UST, which …


Trust Model Measurements For The Energy Grid Of Things, N. Sonali Fernando, John M. Acken, Robert Bass May 2024

Trust Model Measurements For The Energy Grid Of Things, N. Sonali Fernando, John M. Acken, Robert Bass

Electrical and Computer Engineering Faculty Publications and Presentations

Information security is essential for the reliable operation of an Energy Grid of Things (EGoT). In addition to basic information security protocols as defined by published standards, there is a need for a monitoring function that measures the trustworthiness of the various actors participating in an EGoT. We describe in this paper the implementation and evaluation of a Distributed Trust Model that was developed specifically for monitoring communication within an EGoT. We then show how the model parameters are set using statistical measures for hypothesis testing.


An Adaptive Large Neighborhood Search For The Multi-Vehicle Profitable Tour Problem With Flexible Compartments And Mandatory Customers, Vincent F. Yu, Nabila Yuraisyah Salsabila, Aldy Gunawan, Anggun Nurfitriani Handoko May 2024

An Adaptive Large Neighborhood Search For The Multi-Vehicle Profitable Tour Problem With Flexible Compartments And Mandatory Customers, Vincent F. Yu, Nabila Yuraisyah Salsabila, Aldy Gunawan, Anggun Nurfitriani Handoko

Civil and Environmental Engineering Faculty Publications and Presentations

The home-refill delivery system is a business model that addresses the concerns of plastic waste and its impact on the environment. It allows customers to pick up their household goods at their doorsteps and refill them into their own containers. However, the difficulty in accessing customers’ locations and product consolidations are undeniable challenges. To overcome these issues, we introduce a new variant of the Profitable Tour Problem, named the multi-vehicle profitable tour problem with flexible compartments and mandatory customers (MVPTPFC-MC). The objective is to maximize the difference between the total collected profit and the traveling cost. We model the proposed …


Electron-Phonon Interaction Mediated Gigantic Enhancement Of Thermoelectric Power Factor Induced By Topological Phase Transition., Zhi Li, Koushik Pal, Huiju Lee, Chris Wolverton, Yi Xia Apr 2024

Electron-Phonon Interaction Mediated Gigantic Enhancement Of Thermoelectric Power Factor Induced By Topological Phase Transition., Zhi Li, Koushik Pal, Huiju Lee, Chris Wolverton, Yi Xia

Mechanical and Materials Engineering Faculty Publications and Presentations

We propose an effective strategy to significantly enhance the thermoelectric power factor (PF) of a series of 2D semimetals and semiconductors by driving them toward a topological phase transition (TPT). Employing first-principles calculations with an explicit consideration of electron-phonon interactions, we analyze the electronic transport properties of germanene across the TPT by applying hydrogenation and biaxial strain. We reveal that the nontrivial semimetal phase, hydrogenated germanene with 8% biaxial strain, achieves a considerable 4-fold PF enhancement, attributed to the highly asymmetric electronic structure and semimetallic nature of the nontrivial phase. We extend the strategy to another two representative 2D materials …


Meso-Scale Seabed Quantification With Geoacoustic Inversion, Tim Sonnemann, Jan Dettmer, Charles W. Holland, Stan E. Dosso Apr 2024

Meso-Scale Seabed Quantification With Geoacoustic Inversion, Tim Sonnemann, Jan Dettmer, Charles W. Holland, Stan E. Dosso

Electrical and Computer Engineering Faculty Publications and Presentations

Abstract Knowledge of sub-seabed geoacoustic properties, for example depth dependent sound speed and porosity, is of importance for a variety of applications. Here, we present a semi-automated geoacoustic inversion method for autonomous underwater vehicle data that objectively adapts model inference to seabed structure. Through parallelized trans-dimensional Bayesian inference, we infer seabed properties along a 12 km survey track on the scale of about 10 cm and 50 m in the vertical and horizontal, respectively. The inferred seabed properties include sound speed, attenuation, density, and porosity as a function of depth from acoustic reflection coefficient data. Parameter uncertainties are quantified, and …


An Introduction To Nanomaterials For Nanopackaging, James E. Morris Apr 2024

An Introduction To Nanomaterials For Nanopackaging, James E. Morris

Electrical and Computer Engineering Faculty Publications and Presentations

The multiple purposes of an electronics “package” include the provision of mechanical support to the silicon chip, for example, and protection from the environment, the delivery of power in and the facilitation of heat out, and the reliable input and output of information signals, whether electrical or optical. In the age of heterogeneous integration, this includes the internal conversion of signal modes between multiple technologies within the package, while maintaining the traditional requirement of reliable information transmission between packages, e.g., on a traditional circuit board. This article presents some selected examples of nanopackaging, i.e., the application of nanotechnologies, (nanoparticles, carbon …


Machine Learning A Universal Harmonic Interatomic Potential For Predicting Phonons In Crystalline Solids, Huiju Lee, Yi Xia Mar 2024

Machine Learning A Universal Harmonic Interatomic Potential For Predicting Phonons In Crystalline Solids, Huiju Lee, Yi Xia

Mechanical and Materials Engineering Faculty Publications and Presentations

Phonons, as quantized vibrational modes in crystalline materials, play a crucial role in determining a wide range of physical properties, such as thermal and electrical conductivity, making their study a cornerstone in materials science. In this study, we present a simple yet effective strategy for deep learning harmonic phonons in crystalline solids by leveraging existing phonon databases and state-of-the-art machine learning techniques. The key of our method lies in transforming existing phonon datasets, primarily represented in interatomic force constants, into a force-displacement representation suitable for training machine learning universal interatomic potentials. By applying our approach to one of the largest …


Technology Assessment For Cybersecurity Organizational Readiness: Case Of Airlines Sector And Electronic Payment, Sultan Ayed Alghamdi, Tugrul Daim, Saeed Mohammed Alzahrani Mar 2024

Technology Assessment For Cybersecurity Organizational Readiness: Case Of Airlines Sector And Electronic Payment, Sultan Ayed Alghamdi, Tugrul Daim, Saeed Mohammed Alzahrani

Engineering and Technology Management Faculty Publications and Presentations

Payment processing systems have advanced significantly in the airline business. Because e-payments are easy, they have captured the attention of many companies in the aviation industry and are quickly becoming the dominant means of payment. However, as technology advances, fraud grows at a comparable rate. Over the years, there has been a surge in payment fraud incidents in the airline sector, reducing the platform's trustworthiness. Despite attempts to eliminate epayment fraud, decision-makers lack the technical expertise required to use the finest fraud detection and prevention assessments. This research recognizes the lack of an established decision model as a hurdle and …


Energy-Efficient Neuromorphic Architectures For Nuclear Radiation Detection Applications, Jorge I. Canales-Verdial, Jamison R. Wagner, Landon A. Schmucker, Mark Wetzel, Nathan J. Withers, Philippe Erol Proctor, Christof Teuscher, Multiple Additional Authors Mar 2024

Energy-Efficient Neuromorphic Architectures For Nuclear Radiation Detection Applications, Jorge I. Canales-Verdial, Jamison R. Wagner, Landon A. Schmucker, Mark Wetzel, Nathan J. Withers, Philippe Erol Proctor, Christof Teuscher, Multiple Additional Authors

Electrical and Computer Engineering Faculty Publications and Presentations

A comprehensive analysis and simulation of two memristor-based neuromorphic architectures for nuclear radiation detection is presented. Both scalable architectures retrofit a locally competitive algorithm to solve overcomplete sparse approximation problems by harnessing memristor crossbar execution of vector–matrix multiplications. The proposed systems demonstrate excellent accuracy and throughput while consuming minimal energy for radionuclide detection. To ensure that the simulation results of our proposed hardware are realistic, the memristor parameters are chosen from our own fabricated memristor devices. Based on these results, we conclude that memristor-based computing is the preeminent technology for a radiation detection platform.


Contributing Factors To Right-Turn Crash Severity At Signalized Intersections: An Application Of Econometric Modeling, Hisham Jashami, Jason C. Anderson, Hameed Mohammed, Douglas P. Cobb, David Hurwitz Mar 2024

Contributing Factors To Right-Turn Crash Severity At Signalized Intersections: An Application Of Econometric Modeling, Hisham Jashami, Jason C. Anderson, Hameed Mohammed, Douglas P. Cobb, David Hurwitz

Civil and Environmental Engineering Faculty Publications and Presentations

Motorists are required to interact with both roadway infrastructure and various users. The complexity of the driving task in certain scenarios can influence the frequency and severity of crashes. Turning vehicles at intersections, for example, pose a collision risk for both motorized and non-motorized road users. The primary goal of this paper is to investigate the underlying factors which contribute to right-turn crashes at signalized intersections. Five years of crash data across Oregon were collected. A random parameters binary logit model was developed to predict the likelihood of whether a crash resulted in an injury or fatality. It was found …


Wavelength-Induced Shedding Frequency Modulation Of Seal Whisker Inspired Cylinders, Trevor Dunt, Kirby S. Heck, Kathleen Lyons, Christin Murphy, Raul Bayoan Cal, Jennifer A. Franck Mar 2024

Wavelength-Induced Shedding Frequency Modulation Of Seal Whisker Inspired Cylinders, Trevor Dunt, Kirby S. Heck, Kathleen Lyons, Christin Murphy, Raul Bayoan Cal, Jennifer A. Franck

Mechanical and Materials Engineering Faculty Publications and Presentations

The spanwise undulated cylinder geometry inspired by seal whiskers has been shown to alter shedding frequency and reduce fluid forces significantly compared to smooth cylindrical geometry. Undulation wavelength is systematically investigated in order to explore its effect on unsteady lift force and shedding frequency. Prior research has parameterized the whisker-inspired geometry and demonstrated the relevance of geometric variations on force reduction properties. Among the geometric parameters, undulation wavelength was identified as a significant contributor to forcing changes. To analyze the effect of undulation wavelength, a thorough investigation isolating changes in wavelength is performed to expand upon previous research that parameterized …


Nonlinear Interactions Of Sea‐Level Rise And Storm Tide Alter Extreme Coastal Water Levels: How And Why?, H. Moftakhari, D. F. Muñoz, A. Akbari Asanjan, A. Aghakouchak, Hamid Moradkhani, David A. Jay Mar 2024

Nonlinear Interactions Of Sea‐Level Rise And Storm Tide Alter Extreme Coastal Water Levels: How And Why?, H. Moftakhari, D. F. Muñoz, A. Akbari Asanjan, A. Aghakouchak, Hamid Moradkhani, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

Sea-level rise (SLR) increasingly threatens coastal communities around the world. However, not all coastal communities are equally threatened, and realistic estimation of hazard is difficult. Understanding SLR impacts on extreme sea level is challenging due to interactions between multiple tidal and non-tidal flood drivers. We here use global hourly tidal data to show how and why tides and surges interact with mean sea level (MSL) fluctuations. At most locations around the world, the amplitude of at least one tidal constituent and/or amplitude of non-tidal residual have changed in response to MSL variation over the past few decades. In 37% of …


Source Level Of Wind-Generated Ambient Sound In The Oceana, N. Ross Chapman, Michael Ainslie, Martin Siderius Mar 2024

Source Level Of Wind-Generated Ambient Sound In The Oceana, N. Ross Chapman, Michael Ainslie, Martin Siderius

Electrical and Computer Engineering Faculty Publications and Presentations

Inference of source levels for ambient ocean sound from local wind at the sea surface requires an assumption about the nature of the sound source. Depending upon the assumptions made about the nature of the sound source, whether monopole or dipole distributions, the estimated source levels from different research groups are different by several decibels over the frequency band 10–350 Hz. This paper revisits the research issues of source level of local wind-generated sound and shows that the differences in estimated source levels can be understood through a simple analysis of the source assumptions.


Droplet Jump From A Particle Bed, Karl Cardin, Facundo Cabrera-Booman, Raúl Bayoán Cal Feb 2024

Droplet Jump From A Particle Bed, Karl Cardin, Facundo Cabrera-Booman, Raúl Bayoán Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Drop tower experiments have been performed to study droplet jump from a particle bed across a wide range of fluid viscosities. Here the droplet jumps from the particle bed in response to the apparent step reduction from terrestrial gravity to microgravity when the experiment is dropped and enters free fall. The presence of a particle layer has been found to affect contact line dissipation and the overall jumping behavior of droplets. Additionally, the study has identified the impact of the Ohnesorge number (Oh) on droplet morphology. The investigation has yielded results that not only validate a modified version of the …


Implementation Profile: Modeling Environment (Doe-Psu-0000922-3), Sean Keene, Midrar Adham, Robert B. Bass Jan 2024

Implementation Profile: Modeling Environment (Doe-Psu-0000922-3), Sean Keene, Midrar Adham, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

This implementation profile provides the scope, background, and requirements necessary to implement a Modeling Environment (ME) to test a Distributed Energy Resource (DER) Management System (DERMS). A DERMS is used by an aggregator to dispatch large numbers of DERs in order to provide grid services to a Grid Operator. The ME addresses scalability issues inherent to Hardware-in-the-Loop DERMS simulation; a large number of assets are needed in order to observe effects on the grid from deployment and dispatch of DERs.


Data From: Active Transportation Counts From Existing On-Street Signal And Detection Infrastructure, Sirisha Kothuri, Patrick Allen Singleton, Mahyar Vahedi Saheli, Elizabeth Yates, Joseph P. Broach Jan 2024

Data From: Active Transportation Counts From Existing On-Street Signal And Detection Infrastructure, Sirisha Kothuri, Patrick Allen Singleton, Mahyar Vahedi Saheli, Elizabeth Yates, Joseph P. Broach

Civil and Environmental Engineering Faculty Datasets

This study’s objective was to use data from existing traffic signal infrastructure to estimate pedestrian volumes. Pedestrian push-button actuations were collected from signal controller logs at 49 intersections in western Oregon and an additional 16 intersections in eastern Oregon. These actuations were then compared to observed pedestrian counts, totaling over 34,000 people, obtained from video recordings. After exploring various options, a simple quadratic relationship was modeled using a single measure of pedestrian signal activity: the number of push-button presses (filtered to remove multiple presses within 15 seconds). The model’s predictions showed a correlation of 0.86 with observed pedestrian volumes and …


Analyzing Frequency Event Detection Algorithm Performance Using Different Denoising Methods, Hussain A. Alghamdi, Midrar Adham, Robert Bass Jan 2024

Analyzing Frequency Event Detection Algorithm Performance Using Different Denoising Methods, Hussain A. Alghamdi, Midrar Adham, Robert Bass

Electrical and Computer Engineering Faculty Publications and Presentations

Maintaining grid frequency at its nominal value is crucial for power system stability and supply-demand balance. Swift and accurate detection of frequency events is vital for providing primary frequency response support. Frequency event detection algorithms often rely on Phasor Measurement Unit data, which may contain noise. Implementing a denoising preprocessing step enhances detection precision and accuracy. In previous works, a frequency event detection algorithm based on wavelet transform was developed, which uses discrete wavelet transform (DWT) for denoising purposes. In this paper, several denoising techniques are considered as potential replacements for the current DWT method. This research investigates and compares …


Moisture-Controlled Triboelectrification During Coffee Grinding, Joshua Méndez Harper, Yong-Hyun Kim, Robin E. Bumbaugh, Connor S. Mcdonald, Christopher H. Hendon, Elana J. Cope, Leif E. Lindberg, Justin Pham, Multiple Additional Authors Jan 2024

Moisture-Controlled Triboelectrification During Coffee Grinding, Joshua Méndez Harper, Yong-Hyun Kim, Robin E. Bumbaugh, Connor S. Mcdonald, Christopher H. Hendon, Elana J. Cope, Leif E. Lindberg, Justin Pham, Multiple Additional Authors

Electrical and Computer Engineering Faculty Publications and Presentations

Triboelectrification is the physical process where materials acquire surface charge from frictional interactions at their interfaces.The magnitude of charge depends on the interfacial material composition and can be harnessed in emergent technologies for energy generation.

The mechanism of electrostatic accumulation is complex and is further obscured in granular materials where collisions are sufficiently energetic to cause fracturing. In this “fractoelectric” regime, crack initiation and propagation are thought to charge particles through transfer of electrons and/or ions at the hot crack interface.

Whether a material’s charging is dominated by tribo- or fractoelectrification, fracture-generated granular flows often comprise particles whose surface charge …


Experimental And Modeled Assessment Of Interventions To Reduce Pm2.5 In A Residence During Awildfire Event, Chrissi Argyro Antonopoulos, H. E. Dillon, Elliott T. Gall Jan 2024

Experimental And Modeled Assessment Of Interventions To Reduce Pm2.5 In A Residence During Awildfire Event, Chrissi Argyro Antonopoulos, H. E. Dillon, Elliott T. Gall

Mechanical and Materials Engineering Faculty Publications and Presentations

Increasingly large and frequent wildfires affect air quality even indoors by emitting and dispersing fine/ultrafine particulate matter known to pose health risks to residents. With this health threat, we are working to help the building science community develop simplified tools that may be used to estimate impacts to large numbers of homes based on high-level housing characteristics. In addition to reviewing literature sources, we performed an experiment to evaluate interventions to mitigate degraded indoor air quality. We instrumented one residence for one week during an extreme wildfire event in the Pacific Northwest. Outdoor ambient concentrations of PM2.5 reached historic …


Floating Wind Farm Experiments Through Scaling For Wake Characterization, Power Extraction, And Turbine Dynamics, Juliaan Bossuyt, OndˇRej FercˇÁk, Zein Sadek, Charles Meneveau, Dennice Gayme, Raúl Bayoán Cal Dec 2023

Floating Wind Farm Experiments Through Scaling For Wake Characterization, Power Extraction, And Turbine Dynamics, Juliaan Bossuyt, OndˇRej FercˇÁk, Zein Sadek, Charles Meneveau, Dennice Gayme, Raúl Bayoán Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

In this study, wind and water tunnel experiments of turbulent wakes in a scaled floating wind farm are performed. Scaling of a floating wind farm with a scaling ratio of 1:400 is made possible by relaxing geometric scaling of the turbine platform system, such that the dynamic response can be correctly matched, and to allow for relaxing Froude scaling such that the Reynolds number can be kept large enough. Four dimensionless parameters, describing the relative importance of wind and wave loads compared to turbine inertia, are used to guide the scaled floater design. Free decay tests of the pitch and …


Chemical Strategies To Mitigate Electrostatic Charging During Coffee Grinding, Joshua Méndez Harper, Christopher H. Hendon Dec 2023

Chemical Strategies To Mitigate Electrostatic Charging During Coffee Grinding, Joshua Méndez Harper, Christopher H. Hendon

Electrical and Computer Engineering Faculty Publications and Presentations

The process of grinding coffee generates particles with high levels of electrostatic charge, causing a number of detrimental effects including clumping, particle dispersal, and spark discharge. At the brewing level, electrostatic aggregation between particles affects liquid-solid accessibility, leading to variable extraction quality. In this study, we quantify the effectiveness of four charge mitigation strategies. Our data suggests that adding small amounts of water to whole beans pre-grinding, or bombarding the grounds with ions produced from a high-voltage ionizer, are capable of de-electrifying the granular flows. While these techniques helped reduce visible mess, only the static reduction through water inclusion was …


Quantum Algorithms For Unate And Binate Covering Problems With Application To Finite State Machine Minimization, Abdirahman Alasow, Marek Perkowski Dec 2023

Quantum Algorithms For Unate And Binate Covering Problems With Application To Finite State Machine Minimization, Abdirahman Alasow, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

Covering problems find applications in many areas of computer science and engineering, such that numerous combinatorial problems can be formulated as covering problems. Combinatorial optimization problems are generally NPhard problems that require an extensive search to find the optimal solution. Exploiting the benefits of quantum computing, we present a quantum oracle design for covering problems, taking advantage of Grover’s search algorithm to achieve quadratic speedup. This paper also discusses applications of the quantum counter in unate covering problems and binate covering problems with some important practical applications, such as finding prime implicants of a Boolean function, implication graphs, and minimization …