Digital Commons Network^™

Anthropogenic Litter In Freshwater Ecosystems: Effect On Ecosystem Processes And Spatial Distribution, Emily Johnson

Master's Theses

The rapid increase of plastic production and disposal into the environment has resulted in anthropogenic litter (i.e., trash; AL) becoming a global problem. In aquatic ecosystems, macro- and microplastics are long-lived, mobile, and interact with the physical and chemical components of aquatic ecosystems. Our objectives were to: (1) assess the impact of microplastic pollution on the ecosystem processes of ecosystem metabolism and N2 flux in an oligotrophic lake and (2) to assess the abundance and assemblage of anthropogenic litter in a large urban river. For objective (1), we added microplastics at a range of concentrations to littoral mesocosms. Ecosystem metabolism …

A Novel Approach To Treat Trastuzumab Resistant Her2+ Breast Cancer: Activation Pkcδ, Maria Grazia Mejia Monroy

Master's Theses

In the United States, approximately one in eight women will be diagnosed with invasive breast cancer in her lifetime and one in forty will die from breast cancer. From among all the different subtypes of breast cancer, HER2+ can be found in approximately 20% of breast cancer tumors. HER2 overexpression has been associated with an aggressive form of breast cancer, increasing the risk of metastasis or recurrent tumors in 50% of patients. The standard of care for HER2 positive breast cancer, trastuzumab, has been effective for some patients; however, others develop resistance over time, leading to disease progression and metastasis. …

Novel Electrospinning Techniques For Fabricating Scaffolds To Model Intracranial Atherosclerotic Disease In Tissue Engineered Blood Vessel Mimics, Isaac "Squeaky" Buentipo

Master's Theses

Novel Electrospinning Techniques for Fabricating Scaffolds to Model Intracranial

Atherosclerotic Disease in Tissue Engineered Blood Vessel Mimics

Isaac “Squeaky” Buentipo

Dr. Kristen Cardinal’s Tissue Engineering Lab at California Polytechnic State University specializes in fabricating customized vascular models, known as Blood Vessel Mimics (BVMs), for medical device testing. BVMs are simplified in vitro vascular models designed to bridge the gap between bench testing and in vivo evaluation of intravascular medical devices. BVMs are produced by combining a polymer scaffold with human vascular cells. Through novel scaffold fabrication techniques, such as silicone injection molding, silicone dip casting and electrospinning, the capabilities of …

Effects Of Spirulina And Nannochloropsis Supplementations On The Meat Quality And Sensory Properties Of Broiler Carcasses, Shreyash S. Patel

Master's Theses

Microalgae are a promising feed ingredient due to their high content of proteins, lipids, polysaccharides, vitamins, pigments, and enzymes. This study evaluated the effects of algae as a dietary supplementation on the appearance, quality, and sensory attributes of broiler carcasses. In each of experiment I and II, a total of 54 Ross-708 broilers were randomly obtained from the pool of 270 broilers in the 18 floor pens of soybean-mealbased diets at 0, 2.5%, and 5% Spirulina (Experiment I) and Nannochloropsis (Experiment II) supplements in the Poultry Unit at California Polytechnic State University (Cal Poly, San Luis Obispo, CA). Broiler carcasses …

A Manufacturing Process For Interdigitated Microelectrodes On Glass Wafers, Wyatt W. Warfield

Master's Theses

This study presents work done to optimize the process parameters to produce interdigitated electrodes on a borosilicate wafer. Using designed experiments and statistical analysis, the error in pattern transfer was minimized using for key process steps including exposure time, develop time and post exposure bake duration. Similarly, statistical analysis was used with profilometry data to fine tune the develop times. Qualitative analysis was used to assess thin film deposition. The resulting process produced wafers with improved pattern transfer and adequate film adhesion

Video Game Hacking, A General Problem With Generalized Solutions, Luke Rowe

Master's Theses

As video games continue to get more popular and lucrative, the number of malicious actors seeking to exploit them grows with it. As this industry expands, so does the importance of securing games against cheating and abuse. This thesis aims to educate developers to help mitigate the abuse of video games by these malicious actors. The goal of this thesis is to provide a foundational framework for thinking like a hacker and how to make games harder to abuse once a hacker bypasses conventional anti-cheat software.

This thesis outlines some of the most common cheating methods and provides general context …

Optimizing Microfluidic Murine Fibroblast And Human Epidermal Keratinocyte Cell Culture In 70Μm Microwells, Christian Navarro

Master's Theses

Cell culture is an essential technique utilized in biotechnology and medicine to remove systemic influences to study cellular behavior and morphological development of individual cell lines. However, conventional cell culture is two-dimensional and static meaning it can’t easily mimic in vivo conditions such as multicellular cell to cell interactions, fluid perfusion, or 3D structures which might alter cellular behavior and morphology. Microfluidic cell culture allows for the incorporation of in vivo conditions such as perfusion and chemical gradients allowing for more physiologically accurate models. The goal of this study is to develop a protocol for testing a microfluidic chip designed …

Studies On The Effects Of Cap Management On The Oxidation–Reduction Potential, Phenolic Composition, And Sensory Properties Of Red Wines, Dallas J. Parnigoni

Master's Theses

Cap management during alcoholic fermentation of red wines plays a critical role in modulating the phenolic and volatile extraction from grape solids, influencing the homogenization of chemical and temperature gradients, while imparting oxygen to the must. Different cap management alternatives are also thought to influence the evolution of the oxidation-reduction potential (ORP). It is critical to understand how different cap management protocols affect these variables to design a cap management protocol tailored to wine style and varietal. This thesis investigated the effects common commercially applied cap management protocols, as well as the efficacy of novel, automated gas mixing protocols as …

Effectiveness Of Nutrition Education On Male Student Veterans From Cal Poly, San Luis Obispo University, Keith S. Kim

Master's Theses

This pilot study evaluated the effectiveness of a 13-week nutrition education intervention designed to improve dietary patterns, physical health, and mental health outcomes among 10 student male military veterans at California Polytechnic State University, San Luis Obispo. The intervention, grounded in the Dietary Guidelines for Americans, 2020–2025, included a one-time educational presentation and periodic recap videos to reinforce key messages. Outcome measures included dietary intake, body mass index (BMI), handgrip strength, depressive symptoms (via the Beck Depression Inventory), and post-traumatic stress disorder (PTSD) symptoms (via the PCL-5). Results revealed no statistically significant changes in dietary patterns, BMI, handgrip strength, …

"Great Big Beautiful Tomorrow": Disneyland, Science, And The Cultural Cold War, Emily Searson

Master's Theses

Disneyland, the popular Anaheim-based theme park in California, opened its doors during heightened Cold War tensions in 1955. In this thesis, I trace the origins of Tomorrowland, one of the five original themed lands in Disneyland that included futuristic rides and attractions to depict Walt Disney’s imagining of the year 1986. I examine Tomorrowland in particular to argue that WED Enterprises (Disneyland, Inc.’s research and development arm) and Disney’s vision of scientific progress aligned with U.S. Cold War policy goals, especially containment. Disney and WED Enterprises meticulously planned Tomorrowland with the help of notable American defense contractors, including the Monsanto …

Tuned Liquid Damper Design Using Liquid Sloshing In A Horizontal Cylindrical Tank, Vedant M. Patel

Master's Theses

Vibration isolation is an essential design requirement for several real word applications including industrial machinery, automobiles and building structures. Different techniques of vibration isolation are employed in each of these applications. One such vibration isolator used in tall buildings is known as the Tuned Mass Damper , where a mechanical mass (pendulum, bogey, cylinder) is located at the top portion of the building and is connected to the building through a suspension. This mechanical mass – suspension system is designed to oscillate out of phase with the building in order to dissipate the vibration. Several buildings such as, Taipei 101, …

Comparing The Effectiveness Of Low Impact Image Analysis To Traditional Vegetation Sampling In A Branford Marsh, Peter T. Porrello

Master's Theses

The growing need for non-intrusive research methods has led to a surge in passive data collection, such as audio recorders, data loggers, and camera traps, in the ecological field. This improves the capacity to observe fragile habitats without causing any harm and gives researchers new perspectives on the natural world. A non-invasive cable camera system is suggested as a means of gathering data to lessen these ecological disruptions. By taking images of the salt marsh's surface, this technique will minimize plant destruction and lower CO2 emissions brought on by foot traffic through the marsh, whilst producing data that is on …

The Application Of Lidar For Classifying Wildland Fuels, Madison Muschetto

Master's Theses

Accurate vegetation classification is critical for modeling wildfire behavior, particularly in fire-prone ecosystems where fuel type influences fire spread and intensity. This study evaluates the effectiveness of UAV-based aerial LiDAR, supplemented by multispectral imagery, for classifying grass, shrub, and tree vegetation types across a grass-dominated landscape. Using canopy height thresholds, vertical profile analysis, LiDAR predictions were compared against field-verified vegetation observations at 80 survey points. Results showed that LiDAR classified grass with high accuracy but was less reliable for detecting shrubs and trees, especially under canopy cover. Misclassifications were most common beneath tree canopies and in areas where low-stature shrubs …

Structural Color Pigments For Waterborne Coatings, Kyle William Liston

Master's Theses

Structural colors offer unique alternatives to conventional pigments, utilizing their microstructures to produce vibrant colors. These pigments offer an alternative source for colorants without the need for less environmentally friendly conventional pigments. In keeping with the sustainability approach, the use of waterborne coatings was chosen over solvent-based coatings. Here we report the synthesis of brushite platelet, silica supraball, and inverse opal pigments. Brushite platelets were produced through a condensation reaction, while silica supraballs were synthesized via the Stöber process and assembly was attempted using an oil-in-water emulsion. Inverse opal was produced through the templating of silica on poly(methyl methacrylate) (PMMA) …

Functionalization Of A Calcium-Based Squaric Acid Metal Organic Frameworks With Amine-Based Polymers For Enhancing Post Combustion Carbon Capture, Corinne D. Watson

Master's Theses

The primary driver of climate change is the release of carbon dioxide (CO₂) from fossil fuel combustion. Global climate change has resulted in sea level rise, adverse weather patterns, and countless other negative global effects. Several carbon-reduction frameworks emphasize the transition to clean energy sources; however, other strategies must be concurrently pursued to immediately and effectively reduce atmospheric carbon dioxide point source emissions. Metal organic frameworks (MOFs) are a promising new technology for post-combustion carbon dioxide capture. The materials are synthesized using organic linker molecules and metal ion joints. Notably, there are several challenges with various types of …

Catalyzed Chemical Recycling Of Poly(Ethylene Terephthalate) For Enhanced Sustainability, Gilberto J. Hernandez-Leypon Jr.

Master's Theses

Plastics are ubiquitous in the production of consumer and industrial products; their chemical stability, low cost of production, and performance versatility make them the best option for many industries. Their inherent benefits, specifically durability, is the basis for the negative environmental impact of polymers. Improper containment of endof-life polymer products causes unintentional migration into the environment. The monomers for many common polymer types are also fossil fuel based further increasing the environmental impact of the plastic lifecycle. Recycling is a possible method of closing the loop of the plastic lifecycle. Currently most recycling is physical, thermally reprocessing used plastics into …

The Effects Of Sirulina And Nannochloropsis Supplementation On Broiler Performance, Intestinal Morphology, And Gut Microbiology, Emily Beckerman

Master's Theses

The poultry industry is constantly searching for new nutritional strategies and better feed conversion ratio to enhance broiler growth and productivity. Microalgae have been shown to improve broiler performance and health depending on species and supplementation levels. The objective of this study was to determine the effects of Spirulina supplementation (Experiment I) and Nannochloropsis supplementation (Experiment II) on broiler production performance, intestinal morphology, and gut microbiology. In Experiment I, a total of 270 broiler chicks (one-day-old Ross 708) were obtained from a local hatchery after vaccinating against Newcastle, Marek’s disease, and Infectious Bronchitis. They were weighed and sorted into 18 …

Compact, Low-Power Underwater Acoustic Modem Characterization And Sensing Network Node Implementation, Lucas W. Lucia

Master's Theses

There is a growing market for compact, power-efficient underwater communication technology. Due to the limited propagation of electromagnetic waves through water, modulated acoustic waves have emerged as an effective means of wireless communication underwater. In decades past, many acoustic modems had been developed primarily for defense customers in larger systems functioning at high power. In recent years, smaller, relatively inexpensive acoustic modems have become available on the market—but data on their performance in a real-world environment is scarce. Companies such as OWL Integrations are interested in employing such acoustic modems as part of sensing networks across multiple mediums. For such …

Minifying Deep Denoising Networks With Knowledge Distillation, Antonio L. Rozzi

Master's Theses

Hearing loss is a prevalent condition, affecting hundreds of millions globally, with a higher incidence among older adults. While hearing aids are the standard treatment, the majority of those who could benefit from hearing aids choose not to wear them, attributing this decision in large part to their inability to perform well in conversations in large groups and in noisy situations. To date, no denoising systems on commercial hearing aids are able to improve speech intelligibility. Recent advances in artificial intelligence research have shown that large deep-learning models can in fact improve speech intelligibility by removing background noise from audio. …

Using Hydrologic And Hydraulic Simulations To Predict Near-Term Effects Of Beaver Habitat Restoration On Flood Flows, Luke S. Stewart

Master's Theses

There is a growing need to predict the complex hydrologic and hydraulic effects of beaver-maintained wetlands. This study uses relatively simple inputs and a replicable methodology to predict flood flow impacts of beaver habitat restoration at the site design scale using the engineering industry’s customary hydrology and hydraulic modeling approach. This study focuses on Toro Creek, the primary drainage for a 15.2 square mile watershed on the California Central Coast.

A hydrologic model of Toro Creek watershed was developed in HEC-HMS to approximate saturated soil conditions typical of late-spring flooding events observed in the region. The hydrologic model was calibrated …

The Northern Elephant Seals (Mirounga Angustirostris) Of The Piedras Blancas Colony: A Story Of Recolonization, Monitoring And Movement, Mackenzie Davidson

Master's Theses

Northern elephant seals (Mirounga angustirostris) are large, ocean migrating carnivores that have a wide distribution along the west coast of North America. Like other pinniped species, northern elephant seals spend considerable time out at sea foraging and return to land to molt and breed. Northern elephant seals were hunted to near extinction in the late 1800s. Due to conservation efforts they have since rebounded, and they currently occupy 27 known terrestrial breeding colonies. Much literature has documented the recolonization, population dynamics, and dispersion of this species. Currently, Piedras Blancas (San Simeon, California) is the largest mainland breeding colony of northern …

Myceli-Yum: Elucidating Structure-Property Relationships For Polymer Degradation By Mycelial Digestion, Jordan Scott Ford

Master's Theses

Since the industrial entrance of polymer plastic materials, plastic has become ubiquitous in both everyday use and waste. Due to inefficiencies and knowledge gaps, current recycling methods are not able to account for the high scale of plastic waste, resulting in the bulk of this waste being landfilled, mishandled, and deposited in the environment. Mycelium, the microorganism responsible for fruiting mushroom bodies and mold growth, holds potential to reduce plastic waste and can potentially be utilized as a method of industrial recycling. Following a drug-design approach, the active site of mycelial enzymes responsible for natural biopolymer degradation have been assessed …

The Effect Of Whole Fruits High In Anthocyanins On Markers Of Glycemic Control In Women, Sophia C. Johnson

Master's Theses

Cardiometabolic diseases are a significant health burden worldwide and remain the leading cause of death among adults in the United States. Type 2 diabetes mellitus (T2DM) is a central component of cardiometabolic dysfunction and substantially increases the risk for cardiovascular disease. As women enter the post-menopausal period, significant declines in estrogen levels lead to a heightened risk of T2DM in this population. Observational and experimental evidence has shown potential for fruits high in anthocyanins (ACs) to reduce the risk of T2DM and improve glycemic control. This systematic review and meta-analysis examined the current research on whole fruits high in ACs …

The Chumash War Of 1824: Revolution And Counterrevolution In The California Missions Santa Inés, Santa Barbara, And La Purísima, Joseph V. Payne

Master's Theses

In 1824, the Indigenous Chumash of Missions Santa Inés, Santa Barbara, and La Purísima de Concepción went to war against the settler-colonial system that bonded them to the mission lands and forced labor regime demanded by the Spanish Franciscan missionaries and compelled by Mexican military force in Alta California. The conflict lasted months and included violent battles and skirmishes at all three missions, the militant occupation and reclamation of La Purísima, a mass exodus to the interior of the territory, and the subsequent counterrevolutionary collaboration of the Spanish missionaries and Mexican military to return many (but not all) of the …

Development Of A Novel Bio-Mimetic Ornithopter With Variable Flapping Angle, Geourg Kivijian

Master's Theses

From the beginnings of flight, flapping-winged flight has been a goal of many engineers to mimic and replicate. With gains in aerodynamic efficiency of flight and certain other favorable characteristics such as reduced noise, higher maneuverability, and surveillance opportunities in urban environments, flapping-wing aerial vehicle(FWAV) designs are consistently pursued in many corners of academia and industry. This thesis goes into the development of a flapping wing aerial vehicle with a Bio-mimetic novel drive mechanism that is cable-driven and can produce variable amplitude and frequency flapping stroke. Employing a Field-Oriented Control (FOC) Brushless Direct Current (BLDC) motor, paired with a bio-mimetic …

Density-Dependent Habitat Selection And Home Range Sizes In A Recovering Population Of Island Foxes (Urocyon Littoralis) On Santa Rosa Island, California, Kathleen B. Elder

Master's Theses

Understanding factors that affect how animals select their home ranges is critical for proper species management, especially for threatened and endemic species. Density-dependent factors can be particularly difficult to understand because studying them requires large fluctuations in population size. The island fox (Urocyon littoralis), endemic to the California Channel Islands, has experienced dramatic fluctuations in population size making it an excellent candidate for studying the effects of density on home range size and habitat selection. In 2009, researchers on Santa Rosa Island took advantage of this “natural experiment” to document fox home ranges and habitat selection at a …

From Conflict To Clarity: Resolving Differences In Habitat Assessments To Inform Conservation Priorities For The Giant Kangaroo Rat, Caroline Mackenzie

Master's Theses

From Conflict to Clarity: Resolving Data Differences in Habitat Assessments to Inform Conservation Priorities for the Giant Kangaroo Rat

Caroline MacKenzie

Conservation strategies frequently rely on habitat suitability models, habitat assessments and species occurrence data to identify areas for protection. However, these methods often produce conflicting inference on species presence and habitat quality, complicating management decisions. This study builds on prior work which used three distinct methods to guide conservation planning for the endangered Giant Kangaroo Rat (Dipodomys ingens): habitat suitability modeling based on abiotic predictors, aerial imagery to assess habitat quality through visible burrow mounds and live-trapping …

Effect Of Household Oil Contamination And Agricultural Soil Contamination On Phyllosilicate Nanocatalyst Performance During Pyrolysis Of Polyolefins, Joey Velasquez

Master's Theses

The effect of household oil and agricultural soil contamination on catalyst performance during polyolefin pyrolysis was simulated on mixed virgin plastic pellets by evaluating contamination influence on mixed plastic degradation temperatures. Three phyllosilicate nanocatalysts including Fulcat435, Fulcat22F and Y-Zeolite were evaluated in this work based on a literature review of catalyzed plastic pyrolysis and these catalysts’ ability to lower plastic decomposition temperature by 50 °C – 100 °C. These findings were confirmed in this research through thermogravimetric analysis of a polyolefin mixture and further developed in furnace experiments containing household oil and agricultural contamination. Household oil contamination deactivated each of …

Remote Monitoring And Control Of Protection Relays Via Programmable Logic Controller, Rio Mcgown-Kauffman

Master's Theses

The purpose of this study is to explore the ability of a programmable logic controller (PLC) to wirelessly monitor and control power protection relays. The technologies surrounding power protection and industrial automation are ever evolving and have developed significantly in recent history. Industrial power applications call for consistent condition monitoring and status updates for various high-importance components. The high-importance components have power protection schemes that are managed by digital relays to trip circuit breakers in fault or unsafe operating conditions. The smart relays have a wide range of capabilities, including communications. Cal Poly assembled a collection of relays from Schweitzer …

Analyzing Player Difficulty Perception In Platformers Through Procedural Level Generation, Sasank Madineni

Master's Theses

Games utilizing Procedural Level Generation (PLG), such as Roguelikes, are becoming increasingly popular in today's gaming sphere. In games employing PLG, levels are generated randomly or pseudo-randomly, and aim to retain player attention through variance in levels between playthroughs. However, when generating levels with variance in structure and design, player enjoyment is often a mixed bag. With low enjoyment, player retention for these games can dwindle. This study explores the efficacy of real-time difficulty adjustment in procedurally generated platformers, as a method for maintaining stable player enjoyment without causing frustration. This thesis focuses on creating a short user experience, MIMEVA, …