Digital Commons Network^™

Measurement Of Pollution Emissions From Natural Gas Stoves: Preparation For An Induction Cooktop Intervention Study, Jessica Zanella Lorensi

Dissertations and Theses

Humans spend ∼90% of their time enclosed in buildings. Indoors environments can be a source of pollutant which can affect health and productivity. Appliances that combust fossil fuels indoors, like stoves, are a critical source of a range of pollutants, like carbon monoxide (CO) and nitrogen dioxide (NO₂). In the US, the usual cooking fuel is natural gas (NG), presented in more than 30% of households in the country. Some studies in the literature linked cooking pollutants, including those specific to gas combustion, to various health conditions, including heart and respiratory diseases. Nitrogen dioxide, for example, can be …

Storm Surge And Tides In Convergent Estuaries: The Case Of Extratropical Storm Merbok In Alaska, Steven Dykstra, Stefan Talke, David A. Jay, Matthew Lobo, Silvia Innocenti, Pascal Matte

Civil and Environmental Engineering Faculty Publications and Presentations

Coastal floods are composed of multiple drivers that interact with coastline geometries and are difficult to differentiate. To investigate the effects of basin shapes on storm surge and tides, we study the landfall of ex-Typhoon Merbok in the east Bering Sea, Alaska. Water levels at 34 stations are detided with a new tide wavelet tool, CWT_Multi (Lobo et al., 2024), and the spatial and temporal shifts in tides and surge are interpreted via long-wave theory. Results show nonstationary semiannual trends in tidal constituents due to ice effects and large interannual variability in mean-sea level (20-40 cm). After removing non-stationary tidal …

What Drives Blockchain Technology Adoption? A Meta-Analysis Across Tam, Tpb, And Utaut Frameworks, Amir Rahmani, Roohollah Ahmadi, Tugrul Unsal Daim, Mehdi Zamani, Dilek Ozdemir

Engineering and Technology Management Faculty Publications and Presentations

Research on blockchain adoption has expanded rapidly, with most studies conceptualizing adoption as behavioural intention. Technology adoption models, such as the Technology Acceptance Model (TAM), the Theory of Planned Behavior (TPB), and the Unified Theory of Acceptance and Use of Technology (UTAUT), are commonly applied to explore blockchain technology adoption (BTA). However, empirical results from the 12 hypotheses associated with these models remain fragmented and, at times, inconsistent, with limited comprehensive quantitative integration. To address this gap, the present study performs a meta-analysis to evaluate the degree and direction of these hypotheses systematically. In accordance with PRISMA guidelines, 149 quantitative …

Lessons From The Club Homeschool Capstone: Testing, Data Discipline, And The Computer Science Curriculum, Shane Brown

University Honors Theses

This thesis looks at the CLUB Homeschool Capstone project to argue that Portland State University's Computer Science curriculum should introduce testing and data quality discipline earlier and more intentionally than it does now. As team lead of a seven-person team, I coordinated sprint planning, communicated with the sponsor, and developed custom Discourse plugins that enhanced an existing forum platform instead of creating a separate application database, as requested by the sponsor. The project's requirements document called for a formal testing plan, but our team lacked the practical experience to implement one. This gap became evident through my internships as a …

Oak Savanna Expansion: Indigenizing Psu's Urban Landscape, Ash Herb

University Honors Theses

Since time immemorial Indigenous Peoples have resided in what is now named Portland of the Pacific Northwest in the Willamette Valley. For hundreds of years, this forested Land has been colonized, razed to stumps and covered in cement in order to build the urban landscape. Due to such destruction on a broad scale, we are experiencing the results of climate catastrophe. By finding ways to reclaim our relationship with Land and returning to Indigenous epistemologies, our urban landscape has the opportunity to shift towards restoration and prosperity. Indigenous plants have existed here, supporting humans in a reciprocal relationship, for thousands …

Spatial Structure And Energy Content Of Wakes Behind Single And Arrayed Undulated Cylinders, Taiga Naomi Drucker-Boisvert, OndˇRej FerˇCák, Jérémie Auzoux, Sarah E. Smith, Zein Sadek, Rowan Moore, Christain T. Murphy, Trevor Dunt, Jennifer A. Franck, Raul Bayoan Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Biologically inspired undulated cylinder geometries significantly influence wake structure and vortex-induced vibrations in turbulent flows, yet the underlying mechanisms are not fully understood. It is further unknown how these influences extend to multi-cylinder arrays, where interacting wakes accumulate and mix. This study examines the wake characteristics of an undulated cylinder and a smooth elliptic cylinder in single- and multi-cylinder array configurations, using particle image velocimetry and proper orthogonal decomposition (POD). Relative to the smooth elliptic cylinder, the undulated geometry induces pronounced spanwise-axial variability, characterized by enhanced near-wake mean momentum and weak far-wake signatures, consistent with reduced turbulent kinetic energy. While …

Of Cables And Threads: Reweaving The Urban Fabric At The Edge Of Bogotá, Federico Pérez Fernández

University Honors College Faculty Publication and Presentations

Over the past two decades, gondola lifts have become central to interventions in urbanLatin America’s auto-constructed peripheries. As cable car urbanism reshapes the city’sedge, it raises fundamental questions about the notion of the “urban fabric” as a socio-material practice, an epistemology, and a site of politics. In Bogotá, the city’s first aerialcable car line has been integrated into the sprawling district of Ciudad Bolívar, revealinga dialectical process of urban fabrication—a form of urban weaving, in the language ofboth experts and residents, that bridges technical retrofits and popular logistics. Thesestate-community interfaces operate beyond the binaries of compromise and dissent, co-optation and …

Improving The Fpga Radio Design Cycle: Implementing Dvb-S2 Modulation Using Verilator And Gnu Radio, Seth Pellegrino

Dissertations and Theses

In embedded digital radio systems, a central challenge is meeting the real-time throughput required to process the samples--especially for space-bound ultra-wideband SDRs which must handle more than 100 Gbps entirely onboard. An FPGA's programmable logic offers sufficient potential, but realizing a particular radio flow is a project usually fraught with defects and long turnaround times. We simulated Verilog modules in a custom harness that adapted a Verilated model to GNU Radio, which allowed for breaking down a complicated radio flow (here, DVB-S2 modulation) into a series of well-bounded problems each with clear criteria for success. The framework, built on open …

Toxic Relationships: Characterization Of A Putative Virally Encoded Toxin In The Thermophilic Archaeal Fusellovirus Ssv1, Jonathan C. Abshier, Patrizia L. Alpapara, Guasåli Tomokane, Kenneth M. Stedman

Center for Life in Extreme Environments Publications

Mechanisms for the maintenance of chronic viruses are poorly understood, particularly for archaeal viruses. Here, we identify the product of Sulfolobus spindle-shaped virus 1 (SSV1) ORF a291 as a putative virally encoded toxin required for growth inhibition but dispensable for viral replication and virion production. Viruses lacking ORF a291 replicated their genomes and formed morphologically normal spindle-shaped particles, yet failed to inhibit the growth of uninfected Saccharolobus solfataricus. Substitution of residues at a predicted N-terminal signal peptide cleavage site abolished growth suppression without affecting replication, suggesting that secretion is essential for toxin function. Despite primary sequence divergence among fusellovirus …

Theoretical Model To Predict The Flexural Response Of Concrete Beams Pre-Tensioned With Cfrp Rods Considering Cfrp Slippage Effects, Yasir Saeed, Karrar Al-Lami, Franz Rad

Civil and Environmental Engineering Faculty Publications and Presentations

The overwhelming costs of maintenance for reinforced concrete structures due to steel corrosion have motivated researchers to look for alternatives. One of the promising alternatives is Fiber Reinforced Polymer (FRP). Among FRP materials, Carbon FRP (CFRP) is the most attractive material for prestressed concrete members due to its high tensile strength and modulus of elasticity. Previous studies investigated the use of CFRP in prestressed concrete through experimental tests and theoretical analysis. However, there is a significant need for more experimental data to develop an accurate model that can accurately predict the behavior of CFRP prestressed concrete beams. In the current …

Understanding Structural Risk: Seismic Demand For Low-Fill Slender Fuel Tanks, David Yang, Sam Anderson

Civil and Environmental Engineering Faculty Publications and Presentations

Older fuel storage tanks, such as those in Oregon's CEI Hub, present significant seismic vulnerabilities, prompting proposals to limit storage capacity as a transitional risk mitigation measure before more permanent retrofitting actions. However, a critical knowledge gap exists regarding the applicability of standard analysis methods, like API 650, to low-fill conditions. This study utilizes the Veletsos-Yang iterative fluid-tank interaction procedure to evaluate the seismic demand of low-fill slender tanks. The analysis reveals that low-fill slender tanks exhibit slightly longer impulsive periods compared to fully-filled tanks with identical fill-height to radius ratios. Furthermore, the fixed roof mass of a low-fill tank …

Seasonal Changes In Sediment Sound Speed Profiles, Charles W. Holland, Chad Smith, Tim Sonnemann

Electrical and Computer Engineering Faculty Publications and Presentations

Marine sediment sound speed profiles in the upper ten meters are generally assumed to be constant with time. Models predict that substantive changes occur because of thermal conduction from seasonally varying bottom water temperature. However, definitive measurements have been lacking. In this work, sediment sound speed profiles obtained during different seasons show significant differences in the upper 9 m of mud at the New England Patch. Gradients in late March 2017 are 6.0 s−1 and in early October 2025, 2.6 s−1. This change is shown to have a significant impact on acoustic propagation.

Fuel Tank Seismic Stability Program-Informed Displacement Maps Of Portland's Critical Energy Infrastructure Hub, Ana Tijerina Esquino

Dissertations and Theses

Oregon's Critical Energy Infrastructure (CEI) Hub in northwest Portland contains a large portion of the state's liquid fuel storage and distribution capacity and is located in an area susceptible to liquefaction and earthquake-induced permanent ground deformation during a Cascadia Subduction Zone earthquake. Initial Seismic Vulnerability Assessments submitted under Oregon's Fuel Tank Seismic Stability program provide valuable facility-specific information, but the assessments vary in subsurface characterization, treatment of fine-grained soils, ground motion selection, and deformation estimation methods. This variability complicates interpretation of regional seismic risk and motivates a consistent corridor-scale analysis.

This thesis develops CPT-informed displacement estimates for representative cross sections …

Slovenian-Assisted Slate Integrated Infrastructure Development Project (Siidp) And Solid-Waste-Management System, Musa Zakari

Hatfield Graduate Journal of Public Affairs

The study was assessed the Slovenian Assisted Slate Integrated Infrastructure Development Project (SIIDP) on its ability to transform the solid-waste-management system. Yet, in a bid to tackle the intractable waste problem in Nigeria, It emphasized the need to have sustainable policy structures, creative infrastructural and technical cross-border cooperation. The research employed a mixed-method design, which included documentary analysis and a survey. Quantitative data were analyzed using multiple linear regression analysis (SPSS version 27), while qualitative insights were analyzed thematically. Their regression analysis found that technology transfer (B = 0.284, p = 0.000), capacity building (B = 0.256, p = 0.001), …

From Policy To Practice: Analyzing Inclusive Education Strategies In Nigerian Internally Displaced Persons (Idps) Camps, Chukwuyem Joel Arimie, Williams Okotie Dr

Hatfield Graduate Journal of Public Affairs

Through high-quality education delivery, inclusive education indicates the pursuit of social justice for all marginalized societies. The study examines how the Edo camp's internally displaced people are impacted by inclusive education policies. Relevant policy and regulatory frameworks pertaining to inclusive education in Nigeria were examined in the research. Because the Hope for the Needy Foundation provides for the educational needs of the children in the camp, interview responses suggest that despite the policy frameworks, strategies for the effective execution of the policy in the IDP camp have not yet been put in place. The article makes the case that the …

Understanding The Role Of Entropy In Designing High-Performance Thermoelectrics, Subrata Ghosh, Soongyu Kwon, Wenjie Li, Dipika Mandal, Amin Nozariasbmarz, Marcia Ahn, Sumanta K. Karan, Allison M. Beese, Yi Xia, Shashank Priya, Bed Poudel

Mechanical and Materials Engineering Faculty Publications and Presentations

The design of high-entropy alloys is effective in lowering thermal conductivity but often reduces carrier mobility, thereby limiting electrical transport properties. Understanding the relationship among configurational entropy, thermal conductivity, and carrier mobility in high-entropy alloys is critical for enhancing thermoelectric performance. We demonstrate that a systematic and substantial increase in configurational entropy in half-Heusler alloys leads to an asymptotic reduction of lattice thermal conductivity. The reduced phonon group velocity and enhanced phonon scattering induced by atomic-scale chemical disorder result in a low lattice thermal conductivity of 2 watts per meter per kelvin at room temperature, with an achievable minimum of …

Summer Proceedings 2026, Computational Modeling Serving Portland, The Altreu Program, Portland State University, Teuscher Lab, Portland State University

altREU Projects

The 2026 Summer Proceedings bring together research conducted by undergraduate students participating in three complementary programs at Portland State University: the National Science Foundation Research Experiences for Undergraduates (NSF REU) site, Computational Modeling Serving Portland; the alternative Research Experiences for Undergraduates (altREU) program, Designing, Programming, and Using Computers to Benefit Society; and the Teuscher Lab internship program.

The NSF REU is a fully virtual, 10-week program centered on computational modeling that serves Portland and the greater region. Students begin with two weeks of intensive training in computational modeling, followed by eightweeks of mentored research with faculty, research collaborators, and community …

Project Prioritization For Near-Optimal Functionality Risk Reduction In Bridge Networks, David Y. Yang, Anteneh Deriba

Civil and Environmental Engineering Faculty Publications and Presentations

Bridge retrofit prioritization is commonly guided by structural vulnerability, traffic conditions, or indirect consequences following a single bridge failure. However, these metrics often fail to identify retrofit projects that maximally reduce system-level functionality risk, because they do not account for the consequences of joint failures among multiple bridges. This presentation develops a mathematically rigorous, gradient-based approach to bridge retrofit prioritization for achieving a near-optimal reduction in functionality risk. This risk is formulated as the expected increase in total travel time given probabilistic bridge survival or failure under external stressors such as earthquakes. By reinterpreting risk as the evidence term in …

Interpretable Deep Reinforcement Learning For Element-Level Bridge Life-Cycle Optimization, David Y. Yang, Seyyed Amirhossein Moayyedi

Civil and Environmental Engineering Faculty Publications and Presentations

The new Specifications for the National Bridge Inventory (SNBI), in effect from 2022, emphasize the use of element-level condition states (CS) for risk-based bridge management. Instead of a general component rating, element-level condition data use an array of relative CS quantities (i.e., CS proportions) to represent the condition of a bridge. Although this greatly increases the granularity of bridge condition data, it introduces challenges to set up optimal life-cycle policies due to the expanded state space from one single categorical integer to four-dimensional probability arrays. This study proposes a new interpretable reinforcement learning (RL) approach to seek optimal life-cycle policies …

Seabed Wide-Angle Reflection Coefficient And Source Radiation Pattern Measurements From A Low-Frequency Multibeam Sonar, Charles W. Holland, Cody R. Henderson, Tim Sonnemann, Bjørnar Langli, Daniel L. Orange

Electrical and Computer Engineering Faculty Publications and Presentations

In acoustic remote sensing, the seabed frequency-domain reflection coefficient contains significant geoacoustic information, namely the depth and frequency dependence of sediment sound speed, density, and attenuation. Typical reflection measurements are performed with a towed source and/or receivers to obtain a range of seabed reflected angles. It is shown here that the measurements can be performed using a hull-mounted low-frequency multibeam sonar with an offboard fixed or drifting hydrophone. To obtain the reflection coefficient (as well as scattering strength and other quantities of potential interest), the multibeam sonar radiation pattern must be known. Radiation patterns and absolute levels of the Kongsberg …

Block Kinematics, Interseismic Coupling And Fault Slip Rates In The Aegean Region From Gps And Earthquake Slip Vector Data: 1. Upper Plate Structures, Konstantinos Chousianitis, Sotiris Sboras, Volkan Özbey, Robert Mccaffrey, Semih Ergintav

Geology Faculty Publications and Presentations

We represent the active deformation of the Aegean region with an elastic‐kinematic block model composed of a finite number of rotating crustal blocks whose boundaries coincide with major active structures. A total of 832 GPS velocities and 146 earthquake slip vectors were inverted to provide estimates of block rotations and interseismic locking on block‐bounding faults so as to best reproduce the observed deformation field. Our regional model allowed us to derive a self‐consistent set of geodetic slip rates for upper plate faults and the Hellenic subduction system, the results of which are presented in a companion paper, and to determine …

Towards Fast Detection Of Suspicious Bluetooth Trackers Using Anomaly Detection, Orobosa Ekhator, Dylan Conklin, Primal Pappachan, Roberto Yus

Computer Science Faculty Publications and Presentations

Detecting malicious Bluetooth Low Energy (BLE) trackers remains challenging because existing approaches rely on fixed time and distance thresholds that are brittle across environments. These heuristics produce false positives in dense environments and require long observation windows before flagging a device. To address these limitations, we present BL(u)E CRAB, a cross-platform (iOS/Android) mobile system that represents nearby devices using three risk factors derived from BLE scan data. Our detection model adapts Clustering-Based Local Outlier Factor (CBLOF) to BLE tracker detection and adds a gap-thresholding mechanism to separate high-scoring outliers from the benign majority. Across micro-benchmarks and end-to-end case studies, CBLOF …

Tidal River Flood Risk Highest During Intermediate Rather Than Peak River Discharge, Leicheng Guo, Adam T. Devlin, Ton Hoitink, Ian Townend, David A. Jay, Zheng Bing Wang, Chunyan Zhu, Hamed R. Moftakhari, Qing He, Fan Xu, Multiple Additional Authors

Civil and Environmental Engineering Faculty Publications and Presentations

Tidal rivers are defined as the tide‐influenced, salinity‐free inland reaches of estuaries. Understanding the occurrence of peak water levels (PWLs) is critical for flood risk management, yet the timing and magnitude of PWLs in tidal rivers have been little studied. We address this gap by investigating PWLs during two catastrophic floods (1954 and 2020) in the tidal Yangtze River, which reveals that PWLs are higher during perigean spring tides under intermediate discharges following peak flow. Three factors modulate the PWLs in tidal rivers: river‐enhanced tidal damping, flow‐elevation hysteresis that raises the falling flow limb of the hydrograph, and low‐frequency subharmonics. …

Predicting Urban Heat‐Related Illness Across U.S. Climate Regions And Demographics, S. E. Brown, Vivek Shandas

Geography Faculty Publications and Presentations

We still know relatively little about how climate, demographics, built environment, and behaviors interact to drive hospitalizations during extreme heat events (EHEs). To address this paucity in understanding, we draw on extant literature to develop a transdisciplinary discrete event system dynamics (SD) modeling approach to address two research questions about the relationship between EHEs and heat‐related illnesses (HRIs): (a) How will changes in EHE frequencies, intensities, and durations in major Metropolitan Statistical Areas (MSAs) across the contiguous United States (CONUS) Climate Regions drive HRI morbidity across demographic, health‐status, and household groups over the coming decades? and (b) What are the …

Improved Method Of Evaluating Gas-Phase Air Cleaners Considering Adsorption And Desorption Mechanisms To And From Internal Test Chamber Surfaces, Casey Douglas Coffland

Dissertations and Theses

Portable air cleaners are playing an increasingly important role in managing indoor air quality in response to pressing issues like wildfire smoke events. Smoke is a complex mixture of gases and particulate matter; while established test methods exist for particulate matter, the dynamic behavior of gaseous pollutants is not well accounted for in current test methods. This is because prevailing air cleaner testing methods typically treat background losses as irreversible, whereas gases can engage in partitioning to and from test chamber surfaces. Ignoring these sorption interactions causes inaccurate estimation of an air cleaner's impact.

A new approach has been developed …

Investigation Of The Lower Block Rows In The King’S Chamber Of The Great Pyramid Using Ultrasonic Testing With Shear Wave Arrays, Benedikt Maier, Amr G. Hamza, Alejandro Ramirez-Pinero, Khaled Taie, Thomas Schumacher, Olga Popovych, Mohamed Elkarmoty, Mehdi Tayoubi, Hany Helal, Christian U. Grosse

Civil and Environmental Engineering Faculty Publications and Presentations

This study investigates the internal geometry of the granite block rows in the King’s Chamber (KC) of the Great Pyramid of Giza using Non-destructive testing (NDT) with ultrasonic testing (UST) using shear wave echo arrays. As part of the ScanPyramids (SP) project measurement campaigns in 2022, the lower two block rows of all four walls were examined using ultrasonic shear-wave echo arrays (PD8000, Screening Eagle Technologies). The measurement strategy initially included rapid overview acquisitions using an 8-channel UST device to identify potential areas of interest. High-resolution, detailed measurements were then performed at these locations, particularly along the north wall (NW) …

Structure–Optical Property Relationships In Amm′Q3 Chalcogenides, Ayat Tassanov, Huiju Lee, Daniel W. Spainhour, Yi Xia, James M. Hodges

Mechanical and Materials Engineering Faculty Publications and Presentations

Ten ACuHfQ₃ (A = Na, K, Rb, Cs; Q = S, Se, Te) chalcogenides were prepared via high-temperature solid-state methods and structurally characterized using single-crystal X-ray diffraction. The type-I AMM′Q₃ structures are defined by the arrangement of HfQ₆ octahedra (O) and CuQ₄ tetrahedra (T) in their layers, which adopt either OTOT (Cmcm, Pnma) or OOTT (Pnma, P2₁/m) connectivity. UV–vis absorption and photoluminescence spectra indicate optical band gaps ranging from 1.2 to 1.7 eV and reveal that OTOT and OOTT variants have direct and indirect band gaps, …

Flexible Load Communication Protocol Mapping Guide: Ieee 2030.5 To Ansi/Cta-2045, Joseph D'Ambrosia

Dissertations and Theses

As more variable renewable energy resources are connected to the grid, new challenges emerge for grid operators. Demand response programs can provide an additional degree of freedom to grid operators, by modulating the patterns of electricity consumption of residential, customer-owned, flexible loads. The success of demand response programs requires robust and reliable systems of communication between grid operators and flexible loads.

The ANSI/CTA-2045 communication protocol enables customer-owned devices to act as flexible loads. The SEP 2.0/IEEE 2030.5 communication protocol is used to manage distributed energy resources, including flexible loads. Interoperability can be realized by mapping ANSI/CTA-2045 and SEP 2.0/IEEE 2030.5 …

Beyond Predation: Invasive Green Crab (Carcinus Maenas) Alters Juvenile Pacific Oyster (Magallana Gigas) Function And Survival Across Environmental Gradients, Isabel Helena Mize

Dissertations and Theses

The establishment of the invasive green crab, Carcinus maenas, creates ecological and economic impacts in estuaries, particularly through predation on bivalves and alteration of species interactions. This thesis evaluates the direct predation, non-consumptive predator presence, and spatial management implications of C. maenas impacts on filtration rate of juvenile Pacific oysters, Magallana gigas, across laboratory, field, and GIS-based vulnerability mapping approaches. In laboratory conditions, clearance rates of M. gigas were measured over 72 hours across two temperatures (14°C and 18°C) and predator treatments including C. maenas, Pacific rock crab (Romaleon antennarium), both predators together, and a …

Low Cost Lightning Localization At Microwave Frequencies, Bradley Glaubitz

Dissertations and Theses

High precision lightning localization is essential for atmospheric research and public safety, yet the high cost of traditional VLF/LF systems restricts high resolution detection primarily to well funded agencies. Furthermore, conventional low frequency receivers often overlook microwave frequency emissions associated with lightning leader development. This thesis proposes a compact, low cost microwave frequency localization system operating in the 1.42 GHz band to provide an accessible alternative for high resolution mapping. The methodology utilizes an ARM Cortex M0+ microcontroller and a triggered 64 MHz 32 bit counter synchronized to a GPS Pulse Per Second (PPS) signal, achieving a temporal resolution of …