Digital Commons Network^™

Beyond Beliefs: Factors That Shape Agricultural Plastic End-Of-Life Management Among California Strawberry Growers, Kyle Y. Cahitas

Master's Theses

The practice of using plastics in agriculture is so prevalent it has earned its own name: plasticulture. One key plasticulture tool is polyethylene (PE) mulch film, a thin plastic sheet laid over the field for a single growing season and pulled out before the next. Because PE film is hard to recycle, most of it ends up in a landfill, yet how growers decide what happens to used plastic mulch has rarely been studied. To identify what shapes that decision, this study draws on a survey of California strawberry growers (n = 126). Twenty variables, spanning grower attitudes, farm characteristics, …

Expected Structural Damage, Residual Capacity, And Repairability Of Light-Frame Timber Houses, Mikayla Caruthers

Master's Theses

Earthquake damage in light-frame timber structures is commonly evaluated using peak inter-story drift. However, drift alone does not fully represent the remaining structural capacity of a building or its ability to be repaired following a seismic event. Although expected structural damage, residual capacity, and repairability have each been studied extensively, these concepts are often considered independently, leaving limited guidance that links them within a unified post-earthquake assessment methodology.

This thesis establishes an integrated framework that relates expected structural damage, residual capacity, and repairability for light-frame timber residential structures. Existing literature was synthesized to develop drift-based damage-state classifications, identify methods for …

Synthesis And Characterization Of Carbon Quantum Dots And Gold Nanoparticles For Norovirus Biosensing Applications In Water Systems, Breanne Evans

Master's Theses

Rapid, reliable detection of viral pathogens remains a significant challenge across water-treatment and environmental monitoring systems, including drinking-water, wastewater, water reuse, and environmental surveillance applications. Waterborne viral contamination can pose substantial public-health risks, making early detection essential for protecting water quality and responding quickly to treatment failures or contamination events. Direct potable reuse (DPR) is one particularly demanding example because it requires continuous verification of treatment performance and the broader need for rapid virus monitoring extends across many water-treatment and environmental surveillance applications. Norovirus is a priority target because of its widespread occurrence in wastewater, environmental persistence, and exceptionally low …

A Technoeconomic And Lifecycle Analysis Of Catalytic Non-Thermal Plasma Steam Methane Reforming For Renewable Hydrogen Production, Gustav M. King

Master's Theses

When produced with sufficiently low life-cycle emissions, hydrogen may support low-carbon, dispatchable electricity generation to realize statewide renewable energy regulatory objectives. This thesis develops a screening-level electrothermochemical process model of catalytic non-thermal plasma steam methane reforming (CNTP-SMR) and integrates it with techno-economic and life-cycle assessments. Biogas and natural gas fed CNTP-SMR scenarios are compared with conventional steam methane reforming to evaluate hydrogen production cost, global warming potential, and the effects of key operating parameters. Under the baseline assumptions, CNTP-SMR generated hydrogen at a higher levelized cost (baseline of $3.86/kg H₂ and a range of $3.68 to $4.11) when compared …

Developing A Rapid Urban Forest Assessment System For Sustainable City Greenification, Daniel Gonzalez

Master's Theses

This thesis presents the Rapid Urban Forest Assessment (RUFA) system, a web-based platform that integrates urban tree inventories and aerial tree detection to assess forest health across California’s census-designated places. RUFA combines inventoried tree records with coordinates detected from high-resolution multispectral imagery using convolutional neural networks, then computes a composite RUFA Score from four metrics: canopy cover percentage, trees per capita, tree diversity (TD-50), and tree evenness. The thesis addresses two engineering challenges in building the dashboard: querying and aggregating over seven million tree records in real time, and rendering spatial summaries at multiple zoom levels without recomputing cluster assignments …

Low-Cost Modular Transradial Prosthetic System, Caleb E. Barajas

Master's Theses

Upper-limb loss can significantly impact overall quality of life by limiting  a person's ability to perform activities of daily living (ADLs). Although prosthetic devices can help bridge the gap, many upper-limb prostheses are limited by high costs, discomfort, limited repairability, and accessibility barriers. Current commercial myoelectric prosthetic hands can provide high levels of functionality, but are often expensive and require specialized clinical access. In contrast, many current low-cost and open source prosthetic devices improve affordability but are limited in function or designed for partial hand applications rather than full transradial limb loss.

The purpose of this thesis was to design, …

Development And Initial Testing Of Novel Microfabricated Soap Film Frames For Use In Studying Instability Mechanisms In Liquid Sheet Edges, Sam Hastings, Sam Hastings

Master's Theses

The breakup of retracting liquid sheet edges into droplets is governed by instability mechanisms that, in some ways, are not yet fully understood. Previous and limited experimental soap film retraction experiments using straight edges have produced results that differ from the behavior predicted by Rayleigh-Plateau and Rayleigh-Taylor instability models, suggesting that uncontrolled imperfections in traditional wire frames (used to form and detach the soap films) may influence film detachment and the subsequent edge instability observed. This thesis presents the development of a new experimental approach using microfabricated silicon wafer-based soap film frames to provide improved control over the initial conditions …

Development And Evaluation Of Alternative Mandrel Materials For The Fabrication Of In-House Silicone Vascular Models, Cole Capitani

Master's Theses

Dr. Kristen Cardinal’s Tissue Engineering Laboratory at California Polytechnic State University, San Luis Obispo develops tissue-engineered blood vessel mimics (BVMs) for preclinical testing of neurovascular devices. These BVMs are reliant on silicone vascular models that define the vessel geometry, support endothelial cell attachment, and allow devices to be evaluated in a controlled in vitro environment. Previous work in the lab established injection molding as a viable method for fabricating silicone vascular models and utilized acrylonitrile butadiene styrene (ABS) for sacrificial mandrels. However, this workflow relied on the use of acetone for mandrel dissolution, required single-use mandrels, had extended post-processing times, …

Presence Without Exposure: Feminist Pedagogy In The Home-As-Classroom, Kristy Kelly

Feminist Pedagogy

This commentary reflects on teaching during and after COVID-era remote instruction, when the classroom moved into students’ homes and “presence” became equated with visibility. Drawing from a course-based study conducted with students, I describe how patterned differences in men’s and women’s experiences of online participation illuminated the unequal costs of being seen—costs shaped by privacy, domestic constraints, and the risks of interpretation. I argue that feminist pedagogy requires decoupling engagement from visual exposure and designing participation around those most vulnerable to surveillance and stigma in online spaces. The essay outlines practical shifts—camera-optional norms, modality-equivalent participation, structured breaks, and low-stakes entry …

Sitting Together: How Proximity Impacts The Classroom Success Of Undergraduate Women In Engineering, Cassandra M. Savukinas, Kayla D. Taylor, Ashley Lear

Feminist Pedagogy

Despite increased efforts, the engineering field remains predominantly male, particularly within higher education environments. Seating arrangements in the classroom for female undergraduate engineering students can greatly impact their comfort, participation, and academic performance in the classroom. In a 2025 study, it was found that male and female students have differing experiences related to comfort, participation, and academic performance when seated near other students of the same gender (Savukinas et al., 2025). Faculty can help students succeed by understanding how seating dynamics impact students’ experiences in the classroom. By allowing students to choose their own seating arrangements and creating interactions in …

Access Intimacy In The Feminist Classroom: Co-Creating Course Policies, Expectations, And Access Measures As Feminist Disability Praxis, Krystal Cleary

Feminist Pedagogy

In this essay, I outline an activity to foster access intimacy (Mingus, 2011) in the feminist classroom through students’ co-creation of course policies, expectations, and additional access measures. This activity transforms the classroom into a praxis laboratory wherein students analyze the normative structures that shape their hyperlocal classroom context and practice building environments characterized by interdependent solidarity rather than atomized competition. As feminist disability praxis, this activity centers the knowledge of disabled, chronically ill, and neurodivergent scholars and students; in doing so, it customizes the classroom to a diversity of learners and builds adaptability for responding to unforeseen challenges into …

Leader Election System For An Unmanned Ground Vehicle Swarm, Milan Chhetri, Brendan Beas, Paul Levin

Electrical Engineering

This senior project presents the design and implementation of a leader-election system for a leader-follower unmanned ground vehicle (UGV) swarm using embedded control and wireless communication. The objective of the project is to improve the robustness and mission longevity of a multi-agent robotic system by allowing the swarm to dynamically select the most suitable leader during operation. Each UGV is equipped with an ESP32 microcontroller, DWM1000 Ultra-Wideband (UWB) ranging modules, an MPU-6050 inertial measurement unit (IMU), motor drivers, and supporting power electronics to enable communication, sensing, and autonomous control. A battery monitoring subsystem was developed using the ESP32's built-in Analog-to-Digital …

Maximum Power Point Tracker And Dc/Dc Converter, Isabel Aguas, Madeline Steiner, Haley Blouin, Tristan Asquith, Ellijah Garcia

Electrical Engineering

The product is a solar Maximum Power Point Tracker (MPPT) with an integrated DC-DC converter for efficient power extraction from a solar module. The MPPT optimizes solar energy, sourcing power to a 12V battery which is the source of a DC-DC converter operating as a variable voltage output for various applications, capable of providing voltage greater or less than the voltage supplied by the solar module. The DC-DC converter outputs a manually adjustable DC voltage within the range of 5-50V. Both MPPT and the DC-DC converter are functional for standard solar modules with power ratings ranging from 50-400W, open circuit …

Archimedean Spiral Antenna Array With Klopfenstein And Exponential Tapered Balun Feeds, Leo Joseph Alvelais Iv, Paul Obrecht, Naguib Abdulla, Preston Mavady, Collin Fan

Electrical Engineering

This project presents the design, fabrication, and experimental evaluation of a broadband 3x3 Archimedean spiral antenna array tile for 2.8-3.8 GHz. Each element combines a two-arm spiral on Rogers RO4350B, a printed 50 to 150 Ω tapered balun, and a conductive backplane. Klopfenstein and Exponential feed implementations were modeled in Ansys HFSS, generated and tuned with automated scripting, fabricated, and evaluated with calibrated network and anechoic-chamber measurements. The Klopfenstein-fed hardware met the -10 dB input-reflection criterion across the project band. The exponential array provided a broad matched response but reached approximately -8 dB near 2.95 GHz. Measured center-element patterns retained …

Vision-Based Autonomous Tracking Rover, Alejandro Ahumada, Erick Ayala, Jonathan Chavez

Electrical Engineering

AAC Vision designed and constructed a vision-based autonomous tracking rover capable of exploring an indoor environment, avoiding obstacles, generating a two-dimensional LiDAR map, detecting a standard orange basketball, and approaching the target without manual steering. The rover uses a Raspberry Pi 4, an Intel RealSense D435 RGB-D camera, an RPLIDAR C1, four JGB37-520 Hall-encoder motors, dual H-bridge motor drivers, a 12 V battery, and a custom aluminum chassis measuring approximately 8 in by 12 in and weighing 6.7 lb. The final mission emphasized reliable target discovery rather than travel between predetermined points. The software integrates Python, OpenCV, Ultralytics YOLO, RealSense …

System Integration And Validation Of The Cal Poly Spacecraft Attitude Dynamics Simulator Mk. Iv, Bricen S. Rigby

Master's Theses

The Cal Poly Spacecraft Attitude Dynamics Simulator (SADS) is an ongoing project that seeks to enable the simulation and validation of sensors, actuators, and control logic related to spacecraft attitude control. The SADS platform rests atop a spher- ical air-bearing device which allows for nearly frictionless rotation in all three axes. The orientation of the platform is controlled by four reaction wheels arranged in a pyramidal configuration. Over the past few years, there have been significant updates to the reaction wheel subsystem, as well as requests for a more capable central com- puter. Therefore, a new system architecture for the …

Xenaform Algorithm, Alden Ulysses Quandt

Architectural Engineering

This project develops a computer-generated form-finding process for XenaForms, a discrete folded-plate shell system made from rigid triangular panels and hinge-like edge connections. Using Blender and Python, the workflow generates an initial top-down triangular strip, expands it into a fuller shell through stability-guided growth, checks the resulting geometry against a local stability rule, and culls unstable or erroneous elements. The algorithm translates XenaForm stability principles into a usable design tool while also accounting for constructability through sheet-size constraints and geometric collision checks. The result is a Blender-based workflow that can rapidly produce stable, varied XenaForm models for architectural, sculptural, and …

Dc/Dc Converter For A Solar Module, Francine Therese A. Canal, Jesus Cruz, Juan Jose Gonzalez

Electrical Engineering

This project presents the design and implementation of a DC/DC power converter intended for photovoltaic (PV) modules with varying electrical output characteristics. Solar panels experience significant changes in output voltage and power due to variations in sunlight, temperature, and load conditions. To ensure reliable operation across a range of conditions, the proposed converter is capable of both step-up and step-down operation to accommodate solar modules with power ratings from 50 W to 450 W and open-circuit voltages between 10 V and 80 V. The system operates at load currents up to 10 A and provide a user-adjustable output voltage within …

The Regulatory Costs Of Wine Production In Napa County, Lynn Hamilton, Michael Mccullough

Agribusiness

Unlike other food products, commercial alcoholic beverage production has been subject to federal regulation and taxation since the founding of the United States, with specific wine taxes being levied during the wartime Emergency Revenue Act of 1914 (Cilluffo and Gravelle, 2024). Since then, taxation and regulations have expanded, with many new laws originating at the state level. Additional regulatory costs, combined with the current decline in consumer demand raise questions regarding the long-term viability of California wine production. Napa County Farm Bureau contacted Cal Poly to assess baseline conditions in the industry by conducting a case study of regulations accruing …

Dc/Dc Converter For A Solar Module, Stella Uribe, Richie Zaragoza, Olivia Grace Tran, Phillip Tyler Rich

Electrical Engineering

This project focuses on the design and validation of a general-purpose DC/DC power converter intended for use with photovoltaic (PV) solar modules operating under variable environmental and loading conditions. Solar panels exhibit significant variation in output voltage, current, and available power due to changes in irradiance, temperature, and operating point, making direct connection to downstream loads impractical. The proposed system addresses this challenge by providing a single, user-adjustable regulated DC output capable of both stepping up and stepping down the solar module voltage. The converter is designed to interface with solar modules rated between 50 W and 400 W, with …

Remote Controlled Pushcart, William B. Rakoz, Logan M. Beard, Jesus B. Galindo, Jacob Anderson

Electrical Engineering

This senior project developed a low-cost remote controlled golf push cart by retrofitting a conventional cart with independently driven hoverboard wheels, an ESP32 controller, BLE communication, a 36 V battery, an MPU-6050 IMU, an LD-19 LiDAR, and custom PETG components. The final scope emphasized reliable remote operation, differential steering, controlled acceleration, heading stabilization, emergency stopping, and obstacle-aware speed limiting. A separate neural-network controller was trained in simulation as a future autonomy pathway; autonomous target following was not integrated into the final cart. Verification recorded a maximum speed of 4.3 mph, operation on a 15-degree incline, a 0.75 s emergency-stop response, …

Stationary Bike Power/Efficiency Monitor, Paula J. Diaz, Pilar M. Cook, Danielle Rhind

Electrical Engineering

This project developed a real-time power and efficiency monitoring system for a SportsArt ECO-POWR stationary exercise bicycle. The goal was to measure rider mechanical power and electrical power delivered to the utility grid simultaneously, allowing the overall bike-to-grid efficiency to be calculated and displayed in real time. Rider power was measured using Garmin Rally ANT+ power pedals, while grid power was measured using a Yokogawa WT310E power analyzer. A Raspberry Pi 3 Model B+ synchronized both data sources, calculated efficiency, displayed live performance metrics through a graphical user interface, and logged measurement data to CSV files for later analysis. The …

Autonomous Terrain-Mapping Robot For Search And Rescue, Soumil Joshi, Seann Calub

Electrical Engineering

This report documents the design, modular testing, and challenges faced while developing an autonomous terrain-mapping robot intended to navigate to a destination waypoint and deliver a small payload for search-and-rescue applications. The system combines a LiDAR sensor, an IMU sensor, and a Raspberry Pi 3B as the onboard processor, and an ESP32 microcontroller interfacing with motor drivers over a four-wheel chassis. A companion mobile application was developed to enable remote control and monitoring of the robot over a WiFi hotspot connection. A lithium-ion battery pack supplies power to all onboard components, with power budgets verified against component datasheets. Testing progresses …

Evaluating Fungicide Programs For Grapevine Disease Management And Fungicide Sensitivity Monitoring, Abraham Ahumada

Master's Theses

Grapevine diseases, such as powdery mildew and Botrytis bunch rot, require repeated fungicide applications to maintain fruit quality and reduce yield losses. However, fungicide performance can vary among products, application programs, disease pressure, and pathogen sensitivity. This thesis evaluated fungicide programs for control of powdery mildew in ‘Chardonnay’ grapes and assessed fungicide sensitivity of Botrytis cinerea isolates collected from California vineyards.

Powdery mildew, caused by the fungal pathogen Erysiphe necator, is a major threat to the production of Vitis vinifera grapes worldwide. Because powdery mildew management relies heavily on fungicide applications, field evaluations are needed to compare the efficacy …

Environmental Impact Of Preventative Fire-Retardant Products On Soil Chemistry, Elisabeth Kraycik

Master's Theses

Human-caused ignitions account for most wildfires in the United States, particularly along roadsides, utility corridors, and other high-risk infrastructure where fine fuels are abundant and ignition sources are concentrated. These settings are often embedded within grassland and shrubland ecosystems, where fires spread rapidly and can threaten nearby communities and assets. Preventative fire-retardant products (PFRPs) have emerged as a promising strategy for reducing ignition likelihood in these environments. Unlike traditional aerial retardants applied during active suppression, PFRPs are designed for annual, pre-season application to ignition-prone locations. Despite their growing use, the environmental consequences of repeated PFRP applications remain poorly understood, especially …

Flow Conditioning And Vortex Reduction For Vertical Pump Inlets, Charles M. Burt

BioResource and Agricultural Engineering

There are 3 general hydraulic problems for vertical pump inlets. All can cause problems with pump impeller cavitation, reduced flow rates, lower pump efficiencies, and vibrations.

Sunshine Pump: A Trailer-Mounted Solar Powered Water Pump System, Dylan Quan Dinh, Duncan Campbell

Electrical Engineering

The Sunshine Pump is a trailer-mounted, off-grid solar powered water pumping system that delivers approximately 1,000 gallons of water per day from a well of approximately 250 feet total dynamic head to an above-ground storage tank on a rural ranch in Los Osos, California. The system captures solar energy with a 1,500 watt photovoltaic array consisting of four 375 watt panels wired in series, regulates that energy through a maximum power point tracking stage integrated into an all-in-one inverter/charger, stores it in a 4,800 watt-hour LiFePO4 battery, and converts it to 230 volt AC power to drive a 0.75 horsepower …

Ecological Insights From Field And Laboratory Studies Of Akashiwo Sanguinea, Alexis L. Pasulka, Matthew J. Harke, Jaden Hansen, Ryan K. Walter, Eva Kokkino

Physics

Blooms of the dinoflagellate Akashiwo sanguinea occur in coastal ecosystems worldwide and can have significant ecological consequences. Along the central California coast, long-term oceanographic and harmful algal bloom observations indicate that A. sanguinea has exhibited seasonal blooms since approximately 2017, coinciding with negative upwelling anomalies and warm, stratified conditions characteristic of late summer and early fall. In laboratory experiments, three A. sanguinea strains isolated from different sites and/or environmental conditions along the central California coast exhibited variation in growth rates, temperature sensitivity, and transcriptional responses. Under the conditions tested in this study, one strain exhibiting higher maximum growth rates and …

A Guide To Change Management Using The Sarah Model, Sara Kern, Sarah Barbrow, Sarah Jane Dooley, Sarah E. Lester, Sarah Over

Library Scholarship

Academic libraries are the heart of colleges and universities and, as such, are often centrally involved in and impacted by changes in the greater higher education landscape. For those working in these spaces, familiarity with strategies for managing change is essential to support yourself and others during especially turbulent times. The SARAH model, described below in bullet points with our modifications in brackets, offers a memorable way to understand responses to change, be they our own or others.

S - Shock or Surprise
A – Anger [Anxiety, Alert, or Anticipation]
R – Resistance or Rejection [Re-engagement, or Rationalization]
A - …

Hand Mapping: Our Sexual Health Is (Not) In Our Hands, Laura L. Ellingson

Feminist Pedagogy

This Original Teaching Activity introduces hand mapping, an assignment based on the body mapping method, in the context of a communication and gender studies course. Hand mapping can be adapted to interpersonal, organizational, intercultural, and media courses that address identities, intersectionality, communication, culture, and power in different contexts and mediums. Students outline their hands on paper and artfully embellish them as a visual representation of important takeaways or lessons they learned in the course in response to the prompt, “Our sexual health is (not) in our hands.” Students write an “artist’s statement” explaining meanings of color, symbolism, and design.