Digital Commons Network^™

Effect Of The Stacking Sequence And Number Of Ply Orientation In A Quasi-Isotropic Laminated Plate On In-Plane Shear Modulus And Failure Modes, Ann Larson

Master's Theses

Maximizing the shear modulus and strength, as well as predicting failure mode and location, when designing a stacking sequence of quasi-isotropic carbon fiber laminated plates is essential to predict stability, resistance to deformation, and overall stiffness of the structure. This research investigates the effect of the stacking sequence of quasi-isotropic laminated composite plate materials in accordance with ASTM D5379: Standard Test Method for Shear Properties of Composite Materials by the V-Notched Beam Method.

In this research, experimental testing and Finite Element Analysis (FEA) were first used on aluminum to validate the simulation process before applying it to composite materials. The …

Characteristic Stress And Strain Optimization Of Cardiovascular Catheters With Laser-Cut Hypotubes Using Finite Element Analysis, Kyle E. Hirth

Master's Theses

Cardiovascular catheter systems rely on laser-cut hypotubes to balance flexibility and structural integrity required for minimally invasive surgical procedures.  Optimizing these mechanical characteristics remains a significant challenge.  This study aims to investigate the influence of key laser-cut geometric parameters on the mechanical performance of hypotubes through finite element analysis.

Commercially representative laser-cut hypotubes were modeled and a finite element model was developed.   Geometric design parameters were varied across a design space consisting of pitch values ranging from 0.006 in. to 0.018 in. and cuts per revolution (CPR) ranging from 2.5 – 4.5.  For each pitch and CPR combination, loading stiffness …

Analysis And Design Of Auger Cast Piles With Isolation Casing, Zachary Lindsay

Master's Theses

This research addresses the analysis and design of double cased piles. Bay Area Rapid Transit (BART) runs a large rail system both above and below ground that connects the entire Bay Area. BART requires that all new constructions avoid transmitting axial load to their tunnels from adjacent piles. If piles fall within the zone of influence, builders must install double cased piles. Double casing is where there is an extra casing around the pile, with an air gap between them. The air gap prevents load from transferring to the outer casing. The length of this casing is called the isolation …

Aerodynamic Design And Structural Evaluation Of A Global Minimum Torque Inspired Multirotor Propeller, Zeke Bukovansky

Master's Theses

This thesis develops a repeatable design, CAD, aerodynamic postprocessing, structural screening, and manufacturing feasibility workflow for a 22-inch global minimum torque inspired multirotor propeller. Matched MIL and GMT geometries were compared at a 35 N, 4000 rpm static-hover operating condition using BEMT/XFOIL aerodynamic postprocessing, with diameter, blade count, chord distribution, airfoil schedule, and target thrust held constant. The final modeled comparison predicted a modest 1.5% reduction in torque and shaft power for the GMT case while maintaining the same thrust target. CAD construction, MATLAB reduced-order beam model, Abaqus screening, and manufacturing planning were used to identify geometry level structural and …

A2s Uplink Latency Minimization For Wildfire Monitoring Systems Using Mbse And Stochastic Modeling, Luis Giovanni Wang

Master's Theses

Wildfire response depends on how quickly a detection reaches the people who act on it, and the slowest remaining step is often the link that carries an alert from a remote sensing platform to a satellite. This thesis models the latency of that link, the Air-to-Space uplink, for a wildfire-monitoring UAV that carries a Starlink terminal and sends an ALERT packet to a serving Low Earth Orbit satellite. The uplink is difficult to predict because both the UAV and the satellite move, and because the wildfire environment degrades the channel at the moment the data matters most.

The thesis uses …

Synthesis And Characterization Of A Graphene Oxide-Zif-8 Composite For Enhanced Post-Combustion Carbon Capture, Sydney Cooper

Master's Theses

Carbon dioxide (CO₂) emissions from fossil fuel combustion are a major contributor to climate change and its associated environmental impacts. The current standard technology for post-combustion carbon capture, aqueous amine scrubbing, is effective but requires significant regeneration energy and has high operational costs. As a result, solid sorbents have been investigated as lower-energy alternatives. Metal-organic frameworks (MOFs) are a promising class of porous nanomaterials due to their high surface area, tunable pore structures, and adjustable surface chemistry. Among them, zeolitic imidazolate framework-8 (ZIF-8) has high thermal and chemical stability, hydrophobicity, and favorable adsorption properties. However, conventional synthesis methods often rely …

Evaluating The Cost-Benefit Tradeoffs Of Simt Control Mechanisms In Resource-Constrained Gpus, Nikolas Tambornini

Master's Theses

This thesis conducts a hardware-level analysis of the cost–benefit tradeoffs associated with increasingly complex SIMT control mechanisms in a resource-constrained GPU core. Four design implementations are evaluated: a Base Tiny GPU without warp scheduling capability; a Warp Scheduler using round-robin warp selection; a Branch Divergence implementation incorporating a dedicated divergence stack and post-dominator reconvergence mechanism; and a Dynamic Warp Allocation implementation that replaces the static warp structure with a runtime warp manager, regrouping threads by current program counter to recover SIMD lane utilization during active divergence. Each design is evaluated using two complementary measurements: functional simulation implemented using the CocoTB …

Neuron Notes, Araceli Franco, Ethan Diec, Max Blennemann, Shibo Cong

Computer Science and Engineering Senior Theses

Mainstream digital note-taking tools such as Notion, Microsoft OneNote, and Evernote organize knowledge around linear documents and rigid folder hierarchies, a structure that strays from the associative, graph-like nature of human semantic memory. Mind-mapping and linked-note systems such as XMind, Obsidian, Roam Research, and Logseq move closer to that associative model but still constrain users to short labels, automatic layouts, or page-centric workflows that underutilize spatial and visual recall. This thesis presents Neuron Notes, a spatial, graph-based note-taking system designed to align digital organization with how people actually form and retrieve ideas. The system is implemented as a three-tier web …

Table Tennis Training Instrument (Ping Pongers), Derick Alvarado, Peter Sandberg, Andrew Wong

Mechanical Engineering Senior Theses

Table Tennis is an extremely popular sport worldwide, boasting an extensive market. However, it is a sport that generally requires other people to both play and practice with. The goal of this project was to create a machine that would serve table tennis balls for the purpose of individual practice. The machine was meant to fill the niche that other machines of the same type filled by allowing individuals to practice on their own without the assistance of another player or a coach. The main goal of the project was to offer a market competitive device, sharing the same basic …

Inductive Train Transport System, Nicholas Root, Devon Gibb, Ryan Cinarkaya, Davis Letsinger

Mechanical Engineering Senior Theses

Light rail systems can move large numbers of people at relatively high speeds as part of the transit networks critical to dense urban centers, lowering greenhouse gas emissions. However, costs associated with traditional light rail systems are incredibly high and hinder the implementation and expansion of such systems. In this paper, we detail the potential implementation of an inductively-charged, battery-powered light rail system with the potential to lower implementation and expansion costs. This system is compared to existing public transit networks and details of the subsystems required for the successful operation of the planned light rail system are established. As …

Camless Valve Engine, Berkeley Burbank, James Thomas Daniel, Haydn Fischer, Nicos Katigbak, John Holden Kleiner, Martin Raabe

Mechanical Engineering Senior Theses

This project focuses on the design and validation of a camless engine valve system as an  alternative to traditional camshaft-based valvetrain architectures. Conventional engines rely on  fixed camshaft profiles that limit performance and efficiency across varying operating  conditions. The goal of this work is to replace both the camshaft and throttle body with a  pneumatically actuated system capable of independently controlling valve timing, lift, and  duration in real time. By removing the mechanical constraints of a camshaft, the system has the  potential to optimize engine operation across all RPM ranges, improving efficiency and overall  performance without requiring major changes to …

Strategies For Extending The Service Life Of Prestressed Concrete I-Shaped Beams, Sanjoy Kumar Bhowmik

Dissertations

Prestressed concrete (PSC) I-shaped beams are widely used in bridge construction because of their structural efficiency and durability. The service life of these beams is reduced and the maintenance frequency is increased due to the distress during fabrication and subsequent deterioration. Although several mitigation strategies have been proposed and implemented, beam end cracking during fabrication remains a major concern. The causes and mitigation strategies for beam end cracking have been studied for decades, but there have been no comprehensive studies utilizing beam end strains during fabrication and lifting at prefabrication plants under normal operational conditions. Moreover, existing maintenance and repair …

Gas Adsorption Behavior In Organic-Rich Carbonate Source Rocks: Insights Into Hydrogen Storage, Methane Recovery, And Co2 Sequestration In Oil Shales, Muhammad Usman, Muhammad Ali, Tawanda Matamba, Alireza Keshavarz, Stefan Iglauer, Hussein Hoteit, Volker Vahrenkamp

Research outputs 2022 to 2026

Gas adsorption in unconventional petroleum source rocks, e.g. organic-rich mudrocks and shales, is influenced by significant heterogeneities in organic and inorganic composition, structure, and pore networks. An understanding of the interplay between these properties is essential for optimizing hydrocarbon extraction, CO2 sequestration, and hydrogen storage in such reservoirs. Herein, the factors controlling hydrogen, methane, and CO2 adsorption in unconventional organic-rich Jordan source rock samples are investigated, focusing on the roles of organic matter, mineral composition, and textural properties. The samples are characterized via multiple techniques, followed by adsorption experiments. The results reveal that H2 has the lowest adsorption capacity, being …

Multiple-Nozzle Sprays: Comparison To Single-Nozzle Sprays And Role Of Directional Conditional Filtering, Farzad Hossain, Matthew J. Cleary, Yasir M. Al-Abdeli, Mehdi Khiadani

Research outputs 2022 to 2026

Spray-based droplet evaporation systems used in desalination and cooling applications depend on both nozzle arrangement and the interpretation of measured droplet behaviour. This study examines (i) how multi-nozzle configurations differ from single-nozzle characteristics and (ii) how ensemble-averaged measurements change when droplets are separated according to their motion direction (upward or downward). Atmospheric water sprays generated by full-cone spray nozzles were investigated using Particle Image Velocimetry (PIV) for droplet axial velocity measurements and Shadowgraph imaging to determine droplet size and count. Directional filtering was performed using Large Eddy Simulation (LES), validated against experiments. Single- and dual-nozzle configurations were tested with horizontal …

A Novel Multi−Agent Deep Reinforcement Learning Framework For Fast Frequency Response In Inverter−Based Hybrid Power Plants, Muhammad Ikram, Asma Aziz, Daryoush Habibi

Research outputs 2022 to 2026

The increasing penetration of inverter−based resources (IBR) in power grids necessitates novel control techniques to deliver advanced ancillary services such as fast frequency response (FFR), crucial for ensuring power system stability. Existing schemes−droop control, virtual synchronous generator (VSG), and hybrid approaches−require full observability, and centralized control, which are unsuitable for utility−scale hybrid power plant (HPP) with a distributed grid−forming inverter (GFMI). In addition, it lacks adaptive control capabilities in response to real−time disturbances according to the IEEE 2800−2022 standard. To address these challenges, this paper proposes a design of a novel multi−agent deep reinforcement learning (MADRL) framework for utility−scale IBR−dominated …

From Thin Films To Energy Systems: A Perspective-Oriented Translational Framework For Deployable Functional Materials, Mohammad Nur-E-Alam

Research outputs 2022 to 2026

The translation of high-performance thin-film materials from lab-scale development to field-deployable energy systems remains a significant holdup in sustainable technology development. The real-world impact of functional thin films, nanocomposites, and emerging photovoltaic architectures is often limited by issues with scalability, interfacial reliability, environmental stability, and system-level integration, despite their excellent optical and electronic performance at the device level. A translational framework that is deployment-oriented and systematically connects interface-centric device integration, application-context validation, system-level performance feedback, and process-aware thin-film engineering has been presented in this article. Common structure-property-deployment trade-offs are identified through a comparative analysis of representative case domains, such as …

Nanofluid Flooding As A Sufficient Alternative To Waterflooding For Incremental Oil Recovery From Carbonate Reservoirs, Sarmad Al-Anssari, Dhifaf Sadeq, Hassanain A. Hassan, Ahmed Hamid Al-Taie, Hasan Ali Abood, Mohammed Mahdi, Zain Ul Abedin Arain

Research outputs 2022 to 2026

Oil recovery from carbonate reservoirs is one of the critical challenges in the oil industry due to the strongly oil-wet nature, natural fractures, and the heterogeneity of carbonate rocks. Subsequently, waterflooding can only displace oil from large fractures, leaving the majority of oil trapped in the rock matrix. This work suggests that nanofluid flooding, as a predesigned flooding method, is an alternative to conventional waterflooding. Various concentrations of silica nanofluid at different nanoparticle concentrations were formulated and systematically investigated for their characteristics, stability at reservoir conditions, and their influence on wettability and oil recovery. Silica nanoparticles were sustainably synthesized from …

Numerical Evaluation Of A Zero Poisson’S Ratio Structure In Μ-3d-Printed Self-Expanding Nitinol Stents, Farhana Yasmin, Ana Vafadar, Majid Tolouei-Rad

Research outputs 2022 to 2026

Stenting is a minimally invasive treatment used in managing peripheral artery disease (PAD). However, clinical challenges persist, including in-stent thrombosis and restenosis, primarily driven by axial foreshortening or elongation and suboptimal balance between radial stiffness and flexibility inherent to conventional stent designs. This study proposes an innovative arrow-shaped geometry exhibiting zero Poisson’s ratio (ZPR) behaviour for 3D-printed self-expanding Nitinol stents. The complete stent deployment process was modelled using finite element analysis (FEA), including radial crimping and subsequent expansion to enable systematic parametric investigation while accounting for µ-3D printing constraints. Response surface methodology (RSM) rigorously evaluated mechanical performance, defining peak stress, …

Enhancing Urban Refueling Efficiency: Strategies For Sustainable Mobility And Economic Impact, Navid Hashemi Taba, Iftekhar Ahmad, Ahdieh Sadat Khatavakhotan

Research outputs 2022 to 2026

In response to increasing concerns about operational inefficiencies and environmental impacts at petrol stations, this operational research investigates strategies to enhance refueling efficiency across 103 stations in Perth. A pilot study employing observational methods and time-motion analysis established ideal benchmarks for core refueling activities. Empirical analysis of driver behavior during high-demand periods—often driven by fuel price discounts—and regular off-peak hours revealed significant performance gaps, highlighting substantial opportunities for efficiency improvements. Eliminating non-essential tasks could yield time savings of up to 67% during peak periods and 45% during off-peak periods. Economic analysis demonstrated mutual benefits when refueling processes align with these …

Green-Synthesised Nh₂-Mil-101(Cr) Mof–Reinforced Starch Bioplastic Films For Sustainable Food Packaging, Shima Jafarzadeh, Yasaman Esmaeili, Moon Paul, Seyedeh Zahra Haeri, Colin J. Barrow, Mina Dokouhaki, Masoumeh Zargar, Minoo Naebe

Research outputs 2022 to 2026

This study introduces a green, aqueous synthesis approach for NH₂-MIL-101(Cr), avoiding toxic organic solvents while preserving its high crystallinity, porosity (>1000 m2/g), and amino functionality. To develop sustainable packaging materials the synthesized MOF was incorporated into sago starch-based bioplastic films across control 0%, 1%, 3%, and 5% treatments. Nanoparticle characterizations via SEM, TEM, FTIR, XRD, and nitrogen adsorption-desorption isotherms confirmed a porous, crystalline structure (100–300 nm) with a surface area exceeding 1000 m2/g. Film characterizations using SEM, FTIR, color analysis, tensile testing, TGA, and UV-Vis spectroscopy revealed that the 3% treatment offered the best balance, with tensile strength increasing …

Capstone Review: Warn Winch Proximity Sensor, Leana Girton

University Honors Theses

This thesis reviews the mechanical engineering capstone project that designed a winch proximity sensor for WARN Industries. WARN is very interested in developing this product for market as a safety and ease-of-use accessory, and working with Portland State University was the first step in this process. A group of four mechanical engineering and four electrical engineering capstone students collaborated to research sensor types, test the selected methods, and design and build a prototype. The final design implements an inductive ring, a mechanical button, and bluetooth signaling. The project succeeded in prototyping a proximity sensor for WARN, who will have access …

Gps Tracking Smart Dash Cam Capstone Review, Simrah Saleem

University Honors Theses

This thesis details our design, implementation, and collaborative development of an intelligent vehicle logging system built on a Raspberry Pi 5. Unlike standard consumer dash cams that act as closed "black boxes," our system uses a dual-camera stereo vision setup integrated with centimeter-level accuracy. While we successfully built a functional Proof of Concept capable of event-triggered recording, dual-monitor visualization, and smart detection and recognition, this paper focuses on our engineering journey and the real-world challenges we faced. Using an Agile framework, we split into three specialized sub-teams to handle hardware, database, and interface design in parallel. This structure created unique …

Design And Optimization Of A Bluff Body For Energy Harvesting Of Transverse Galloping Induced By Low-Speed Wind Using Bernstein Polynomial Equations, Youssef Wael Abdelmoneim

Theses and Dissertations

In this thesis, a computational framework is proposed for optimizing the aerodynamic shape of bluff bodies used in galloping-based wind energy harvesters. The system targets low-wind speed environments, where normal wind turbines are not effective, offering a potential alternative to batteries used for powering small electronic devices such as wireless sensors. The design relies on the galloping effect, where airflow around a bluff body induces transverse oscillations that drive an energy conversion mechanism. To generate efficient bluff body geometry, the Class-Shape Transformation (CST) method is used to define a wide range of candidate shapes with minimal design parameters. These shapes …

A Review On Credit Card Electronic Fraud Detection Methodologies, Titilayo Mary Sayikanmi, Ibrahim Adepoju Adeyanju, Bolaji Abigail Omodunbi

Mansoura Engineering Journal

Credit card fraud remains a critical and escalating challenge within the global financial ecosystem, driving substantial annual losses and necessitating the continuous evolution of detection methodologies. This paper presents a systematic literature review, conducted via the Preferred Reporting Items for Systematic Reviews and Meta-Analyses framework, which comprehensively analyzes the state-of-the-art in electronic credit card fraud detection. Through a rigorous examination of 49 high-quality studies, this review maps the methodological evolution from traditional rulebased systems and statistical models to advanced artificial intelligence techniques, including machine learning, deep learning, and graph-based approaches. The analysis reveals that while individual methods possess distinct advantages …

Reliable Offline Evaluation Under Exposure Bias: A Cross-Scale Study Of Counterfactual Estimators In Recommender Systems, Lakshmi Pranathi Vutla

Graduate Masters Theses

Offline evaluation underpins model selection in recommender systems, yet historical interaction logs are shaped by prior recommendation policies. Because users only provide feedback on exposed items, logged data entangles user preferences with exposure mechanisms, leading to exposure bias and potentially misleading model comparisons. Counterfactual estimators such as IPS, SNIPS, CRM, and DR offer principled corrections, but their empirical reliability across datasets and exposure regimes remains insufficiently under- stood. We present a systematic, cross-scale study of counterfactual evaluation in recommender systems. Comparing IPS, SNIPS, CRM, and DR on datasets with randomized exposure (Yahoo! R3, Coat, and KuaiRec), we analyze estimator behavior …

Mechanics And Physical Attributes Of Nature-Based Alterations: Rock Reinforcement And Urban Heat Island Assessment, Mary Chikondi Ngoma

Dissertations

Ground improvement is critical to geotechnical and geo-engineering systems, where modification of the properties of geomaterials (rocks and soils) is required to maintain stability and prevent failure of infrastructure installed within and around them. This need has become increasingly important with rapid urbanization and population growth, which intensify demands on surface and subsurface systems and further challenge the performance of supporting geomaterials. As a result, there is growing interest in nature-based solutions, particularly biologically mediated processes such as biocementation, which can enhance the physical, hydraulic, and mechanical properties of geomaterials while offering environmentally sustainable alternatives to conventional ground improvement techniques. …

Enabling Ml/Ai In 6g And Future Wireless Communication With Privacy Preservation, Mec Offloading And Quantum Computing, Changshi Zhou

Dissertations

The forthcoming sixth-generation (6G) and future wireless networks are envisioned to support an unprecedented range of services, delivering ultra-low latency, massive connectivity, and intelligent real-time responsiveness. These capabilities will enable emerging applications such as extended reality (XR), autonomous vehicles (AVs), industrial robotics, and the Internet of Things (IoT) to reach their full potential. Achieving this vision requires the integration of enabling technologies such as artificial intelligence and machine learning (AI/ML) and quantum computing, which are poised to play central roles in shaping the landscape of wireless communication systems.

In AI-native, data-driven, and computing-centric 6G networks, ML models will be deeply …

Holistic Dram Enhancements: From Intrinsic In-Memory Operations To Robust Security Mechanisms, Ranyang Zhou

Dissertations

Dynamic Random-Access Memory (DRAM) is both the performance bottleneck and a critical security boundary of modern computing systems. Its physical properties make it an attractive substrate for near-data computation—yet those same properties expose it to disturbance-based hardware attacks. This dissertation argues that these two dimensions are not independent: the architectural choices that make DRAM efficient also reshape its threat landscape. Addressing both requires a unified approach to memory architecture and security co-design.

The first part of this dissertation attacks the memory wall through four processing-in-DRAM (PIM) frameworks. ReD-LUT and LT-PIM unify lookup-table arithmetic with charge-sharing logic, achieving up to 37.8x …

Vergence Task-Based Neural Pathways With Binocularly Normal Vision And Comorbid Persistent Post-Concussive Symptoms -Convergence Insufficiency, Ayushi Sangoi

Dissertations

Binocular dysfunctions are more prevalent in the persistent post-concussive symptoms (PPCS) population than in the general population. The most prevalent binocular disorder is convergence insufficiency (CI), affecting 3-17% of the general population and up to 10 times as many people with PPCS. CI makes it difficult to fuse or maintain fusion on targets at near, and its symptoms include double or blurry vision and headaches when performing close-range tasks such as reading, which can exacerbate PPCS symptoms. Given controversy over the subjectivity and effectiveness of diagnostic tools and symptom surveys for both PPCS and CI, understanding why CI has high …

A Generative Ai-Driven Computational Framework For Industry-Scale Discovery Of Novel Battery Materials, Joy Datta

Dissertations

The growing demand for sustainable, high-energy-density electrochemical storage has motivated the exploration of multivalent-ion batteries based on earth-abundant elements such as aluminum, calcium, magnesium, and zinc. While multivalent charge carriers offer higher theoretical energy density than lithium, their practical deployment is hindered by sluggish ion transport, strong ion-host interactions, and structural degradation of electrode materials. Identifying host materials that can reversibly accommodate multivalent ions while maintaining structural integrity remains a fundamental challenge. The dissertation develops a scalable, end-to-end computational framework that integrates density functional theory (DFT), machine learning (ML), and generative artificial intelligence (GenAI) to accelerate the discovery of next-generation …