Physical Sciences and Mathematics Commons^™

Empirical Models Of The Hβ Broad Emission Line Gas Density Field, Lizvette Villafaña, Tommaso Treu, Lourenzo Colleyn, Brendon J. Brewer, Aaron J. Barth, Matthew A. Malkan, Vivian U, Vardha N. Bennert

Physics

We present the second iteration of the caramel-gas code, an empirical model of the broad-line region (BLR) gas density field. Building on the initial development and testing of caramel-gas, we expand the meaning of the model parameter α, which initially represented only the power-law index of the dependency of emissivity on radial distance. In this work, we test a more generalized radial power-law index, α, that also includes a description of the effective emitting size(s) of the BLR structure as a function of radial distance. We select a sample of 10 active galactic nuclei (AGN) from three different …

Exploration On Lysing Microalgae Using Pulsed Electric Fields, Fereshteh A. Bunk

Physics

With a dangerously and rapidly changing climate [1], people globally are desperate to reduce CO2 emissions and protect our environment as evidenced by global initiatives such as the United Nations’ Paris Agreement [2]. Traditional fossil fuel extraction and combustion was responsible for 74% of U.S. greenhouse gas emissions in 2019, which contributes to climate change, ocean acidification, extreme weather events, sea level rise, pollution, and health issues which contributed to 350,000 premature deaths in the U.S. in 2018 [3]. This motivates the search for alternative, more sustainable fuel production. There have been many new, more sustainable solutions to traditional fossil …

Characterizing The Ecological Impacts Of Utility-Scale Solar Energy (Usse) On Fallowed Farmland, Amanda Gersoff

Master's Theses

Large-scale carbon-free energy generation projects such as utility-scale solar energy (USSE) arrays help mitigate the energy sector’s contribution to climate change and are rapidly expanding throughout the U.S. However, the expansion of USSE sites is associated with immediate and longer-term ecological impacts, many of which have yet to be assessed. Quantifying the ecological impacts of USSE arrays will help to identify synergies and trade-offs between energy generation and terrestrial conservation goals. The overall goal of this research is to characterize the ecological impacts of USSE sites located on fallowed farmlands in San Luis Obispo County, California in a seasonally explicit …

Non-Relativistic Limit Of Selected Terms From The Sme Dirac Lagrangian, Quinn Reece

Physics

We examine a selection of individual CPT/Lorentz violating terms present in the relativistic lagrangian for a free spin- 1 2 Dirac fermion of mass m in the Standard Model Extension. Euler-Lagrange relations will be applied to give Dirac-like equations including these terms and a novel procedure will be used to generate non-relativistic limits of these equations which are Schr¨odinger-Pauli-like equations. These equations will be analyzed using classical quantum mechanics toy problems to gain physical intuition for the effects of the CPT violating terms, and the results will be discussed. We will conclude with discussion on future work will include the …

Automated Tree Mortality Detection Using Ubiquitously Available Public Data, Michael T. Huggins

Master's Theses

Understanding the dynamic interplay between fire severity, topography, and tree mortality, is crucial for predicting future forest dynamics and enhancing resilience against climate change-induced wildfire regimes. This thesis develops a multi-sensor approach for automated estimation of tree mortality, then applies it to examine trends in tree mortality over a six-year period across a fire affected study site in the Trinity River basin in Northern California. The Random Forest model uses publicly available USGS 3D Elevation Program Lidar (3DEP) and NAIP imagery as inputs and is likely to be easily adaptable to other landscapes. The model had a Receiver Operating Characteristic …

Water Quality Assessment For San Luis Obispo Creek And Stenner Creek, Brent Flemmer

Master of Science in Environmental Sciences and Management Projects

Water quality was assessed in five stream segments in San Luis Obispo and Stenner Creeks in Spring of 2023. Two of the five sites were located along San Luis Obispo Creek, and three located along Stenner Creek. Criteria to evaluate these aquatic systems was provided by the Standard Operating Procedures of the Surface Water Ambient Monitoring Program, formulated by the State Water Resources Control Board. These procedures describe the methodology surrounding the collection of chemical, physical, and biological parameters of stream systems; streamflow, substrate, flow habitat, chemical water quality, and benthic macroinvertebrates are some of the criteria collected that allows …

A Study On Ethical Hacking In Cybersecurity Education Within The United States, Jordan Chew

Master's Theses

As the field of computer security continues to grow, it becomes increasingly important to educate the next generation of security professionals. However, much of the current education landscape primarily focuses on teaching defensive skills. Teaching offensive security, otherwise known as ethical hacking, is an important component in the education of all students who hope to contribute to the field of cybersecurity. Doing so requires a careful consideration of what ethical, legal, and practical issues arise from teaching students skills that can be used to cause harm. In this thesis, we first examine the current state of cybersecurity education in the …

Improving Automatic Transcription Using Natural Language Processing, Anna Kiefer

Master's Theses

Digital Democracy is a CalMatters and California Polytechnic State University initia-
tive to promote transparency in state government by increasing access to the Califor-
nia legislature. While Digital Democracy is made up of many resources, one founda-
tional step of the project is obtaining accurate, timely transcripts of California Senate
and Assembly hearings. The information extracted from these transcripts provides
crucial data for subsequent steps in the pipeline. In the context of Digital Democracy,
upleveling is when humans verify, correct, and annotate the transcript results after
the legislative hearings have been automatically transcribed. The upleveling process
is done with the …

Impacts Of Marine Heatwaves On Subsurface Temperatures And Dissolved Oxygen In The Chesapeake Bay, Nathan P. Shunk, Piero L. F. Mazzini, Ryan K. Walter

Physics

Subsurface impacts associated with Marine Heatwaves (MHWs) in estuaries are not well understood, largely due to data scarcity. Using over three decades (1986–2021) of observations from several monitoring programs, this study investigates subsurface temperature and dissolved oxygen (DO) anomalies associated with surface MHWs in the Chesapeake Bay (CB). Seasonal variability in temperature anomalies followed a simple 1-D response to surface heating with downward heat transport and diffusion controlled by seasonally variable stratification and mixing. Two distinct temperature regimes were found: a thermally stratified spring-summer regime, when positive temperature anomalies were confined to the surface mixed layer (SML); and a homogeneous …

Jwst Lensed Quasar Dark Matter Survey – I. Description And First Results, A. M. Nierenberg, R. E. Keeley, D. Sluse, D. Gilman, S. Birrer, T. Treu, K. N. Abazajian, T. Anguita, A. J. Benson, Vardha N. Bennert

Physics

The flux ratios of gravitationally lensed quasars provide a powerful probe of the nature of dark matter. Importantly, these ratios are sensitive to small-scale structure, irrespective of the presence of baryons. This sensitivity may allow us to study the halo mass function even below the scales where galaxies form observable stars. For accurate measurements, it is essential that the quasar’s light is emitted from a physical region of the quasar with an angular scale of milliarcseconds or larger; this minimizes microlensing effects by stars within the deflector. The warm dust region of quasars fits this criterion, as it has parsec-size …

The Seoul National University Agn Monitoring Project. Iii. Hβ Lag Measurements Of 32 Luminous Active Galactic Nuclei And The High-Luminosity End Of The Size–Luminosity Relation, Jong-Hak Woo, Shu Wang, Suvendu Rakshit, Hojin Cho, Donghoon Son, Vardha N. Bennert, Elena Gallo, Edmund Hodges-Kluck, Tommaso Treu, Aaron J. Barth

Physics

We present the main results from a long-term reverberation mapping campaign carried out for the Seoul National University AGN Monitoring Project (SAMP). High-quality data were obtained during 2015–2021 for 32 luminous active galactic nuclei (AGNs; i.e., continuum luminosity in the range of 1044–46 erg s−1) at a regular cadence, of 20–30 days for spectroscopy and 3–5 days for photometry. We obtain time lag measurements between the variability in the Hβ emission and the continuum for 32 AGNs; 25 of those have the best lag measurements based on our quality assessment, examining correlation strength and the posterior lag distribution. Our …

Evaluating Corporate Marine Plastic Pollution Reduction Pledges: Achieving Plastic Reductions Or Contributing To Greenwashing, Ansar Z. Mohammed

Master of Science in Environmental Sciences and Management Projects

This paper examines major corporations' commitments and performance in reducing virgin plastic production, aligning corporate initiatives with tangible outcomes. It draws on sustainability governance literature and analyzes plastic reduction strategies by industry leaders such as SC Johnson, PepsiCo, Coca-Cola, Borealis, Nestlé, and Unilever. By synthesizing corporate reports and scholarly literature, the research provides an understanding of corporate plastic reduction within the framework of Sustainable Development Goal 14 (SDG 14), which focuses on marine conservation. The study evaluates the alignment of corporate commitments with SDG 14, identifying genuine environmental stewardship and potential greenwashing. It employs three methodologies: transparency, accountability, and science-based …

Improving Document Classification By Integrating Human-Crafted Semantic Knowledge, Lubomir Stanchev, Zachary Weinfeld

Computer Science and Software Engineering

Document classification is a pivotal task in various domains, warranting the development of robust algorithms. Among these, the Bidirectional Encoder Representations from Transformers (BERT) algorithm, introduced by Google, has proven to perform well when fine-tuned for the task at hand. Leveraging transformer architecture, BERT demonstrates stellar language understanding capabilities. However, the integration of BERT with a range of approaches has shown potential for further enhancing classification accuracy. This paper investigates three techniques that leverage semantic understanding to improve the performance of document classification models trained with BERT. First, we balance corpora afflicted by imbalanced training data distributions. Next, we substitute …

Ungrading: Reflections Through A Feminist Pedagogical Lens, Erin M. Eggleston, Shelby Kimmel

Feminist Pedagogy

Ungrading is a pedagogical approach in which no grades are given on any assignments. Instead, students are provided with many opportunities to submit work and gain feedback. The goal is to shift student focus from achieving a grade to growth as a learner and a person. As instructors, our ungrading approach utilized personalized learning plans, checkpoint reflections, and student-professor learning conferences to put agency in the hands of our students. We employed this method in upper-level biology and computer science courses and provide critical reflections here regarding our experiences and the connections between this approach and feminist STEM pedagogy tenets. …

Centering Equity In Stem Teaching: Stem Ideas That Change The World, Ileana Vasu

Feminist Pedagogy

No discussion on equity/inequity makes sense without bringing power into that discussion. As instructors we need to ask questions such as “who decides and controls what knowledge is”, “whose identities are empowered and whose are erased”, “who has access and opportunity and who doesn’t”. Traditional teaching in STEM, including mathematics, assumes knowledge is objective, transmittable, repeatable to everyone. When educators follow a traditional curriculum, just like their teachers before them, they do so thinking their methods ensure equality and objectivity. These practices not only deny the role that Western patriarchal cultures have played in creating these so-called equitable practices, but …

Building Community, Competency, And Creativity In Calculus 2: Summary Of A Pilot Year Of Project Implementation, Jennifer Beichman, Candice R. Price

Feminist Pedagogy

In light of the COVID-19 pandemic, instructional modes at our institution moved to fully online and remote, then fully online but on campus, and back to in-person learning in fall 2021. To combat perceived issues in student engagement, we piloted using group projects in place of exams at the natural content break points in Calculus 2.

Feminist Pedagogy In Stem: The Intersection Of Stem Pedagogy And Feminist Theory, Lesley-Ann Giddings, Candice R. Price

Feminist Pedagogy

No abstract provided.

Using Remote Sensing To Determine Riparian Resilience In Beaver Dammed Versus Un-Dammed Corridors Following Whiplash Weather, Sophie Charlotte Valérie Aubry

Master of Science in Environmental Sciences and Management Projects

Beaver complexes slow and store water allowing for riparian growth which in turn fosters biodiversity, retains carbon, and enhances resistance to fires and drought. Given the benefits associated with beaver complexes and the potential they have for climate mitigation, California hopes to reintroduce beavers and restore their habitat throughout the state. However, the impact of high peak flow events on beaver complexes and their adjacent riparian corridors is less understood and requires more documentation at various spatial scales. To better understand the potential beavers may have as climate change mitigators it is important to understand beaver complex resiliency following a …

Effects Of Arbuscular Mycorrhizal Fungi Inoculation And Cover Crop On Soil Carbon Dynamics And Microbial Communities In A Mediterranean Lemon Orchard., Anna Rodriguez-Paiatsyka

Master of Science in Environmental Sciences and Management Projects

Plant-associated fungi such as arbuscular mycorrhizal fungi (AMF) have the potential to sequester carbon (C), improve soil aggregation, and promote plant health. Due to multiple benefits of AMF to plant and soil health, AMF has gained much attention leading to a rapidly expanding market in mycorrhizal bio-stimulants intended to improve crop yield, root development, and soil health in horticultural crops, including citrus. However, there is limited information on how to inoculate a mature citrus orchard, and how inoculation of a mature orchard with AMF affects C sequestration. In this study, we planted a cover crop inoculated with AMF in a …

Soil Burn Severity And Environmental Covariate Effects On Soil Health Two Years Postfire In The Sierra Nevada, Julie A. Lewis

Master of Science in Environmental Sciences and Management Projects

Wildfires have been steadily increasing in both size and severity in recent decades. This global trend is most evident in California, especially the North Coast and Sierra Nevada. Although these trends are rising, there is little known about the effects of these wildfires on forest soils. Soil is the 2nd largest C sink on the planet, and the largest terrestrial bank. Without understanding the implication of rising wildfire severities on these soils, we cannot understand how to help protect this resource in the future. Due to the rapid increase in wildfire size and intensity, there is little known about the …

Foundations Of Memory Capacity In Models Of Neural Cognition, Chandradeep Chowdhury

Master's Theses

A central problem in neuroscience is to understand how memories are formed as a result of the activities of neurons. Valiant’s neuroidal model attempted to address this question by modeling the brain as a random graph and memories as subgraphs within that graph. However the question of memory capacity within that model has not been explored: how many memories can the brain hold? Valiant introduced the concept of interference between memories as the defining factor for capacity; excessive interference signals the model has reached capacity. Since then, exploration of capacity has been limited, but recent investigations have delved into the …

The Biological, Physical And Chemical Response Of The Little Creek Watershed To The 2020 Czu Lighting Complex Fire, Natalie Fontana

Master's Theses

This post-fire study was conducted to characterize and observe fire induced changes in physical habitat parameters, water-quality conditions and macroinvertebrate assemblages in the Little Creek watershed, a tributary to Scotts Creek located in Cal Poly’s Swanton Pacific Ranch in Davenport, California. Pre-fire data was collected by a Cal Poly student, John Hardy, for his 2017 thesis. Post-burn bioassessment surveys for this study were repeated at four of the same study sites used by Hardy to provide comparisons to the California Stream Condition Index via a modified version of the State of California’s Surface Water Ambient Monitoring Program protocol. Macroinvertebrates were …

Nanoparticles And The Environment: Biopolymer Grafted Cellulose And Screen-Printed Carbon Nanotube Composites, Dominique Henry Porcincula

Master's Theses

A host of environmental issues will define the state of the environment in the 21^st century, with plastic pollution and water shortages among them. While solutions to these problems require large-scale, multipronged solutions, one way we can address them is through material innovation and the use of nanoparticles.

In the first project, we address the issue of plastic pollution by creating nanocomposites of biodegradable polymers (PLA and PCL) with cellulose nanofibrils. Here, PLA and PCL are grafted from the surface of cellulose nanofibrils via ring-opening polymerization of cyclic ester monomers. Polymer-grafted cellulose (PGC) is characterized with structural analysis, solubility …

Temporal And Spectral Analysis Of 1es 2344+514 In Two Flaring States Observed By Veritas, Connor Poggemann

Physics

VERITAS observed the bright blazar 1ES 2344+514 during two flaring periods, one from Dec. 17 to Dec. 18, 2015 (MJD 57373-57374) with a peak flux of ~60% of the Crab and another from Nov. 28 to Dec. 3, 2021 (MJD 59546-59551) with a peak flux of ~20% of the Crab. This blazar, located at a redshift of z = 0.044, is classified as an extreme high-frequency-peaked BL Lacertae object (HBL). It is known to be variable, including several previous day-scale flares: Whipple on Dec. 20, 1995, VERITAS on Dec. 7, 2007, and MAGIC on Aug. 11, 2016. The VERITAS near-nightly …

Interactive Water Vortex Exhibit, Simon Way, Emily Laing, Roqaya Naseri, Makenzie Kan

Mechanical Engineering

The San Luis Obispo Children’s Museum requested an interactive water vortex exhibit to both engage and entertain inquisitive guests, ages two to eight. The goal was to design and manufacture an exhibit that would educate its users on the fluid mechanics behind water vortices. They activate the mechanics by spinning a wheel, which is perceived as the catalyst to manipulate the flow of water to successfully create a whirlpool. Our team has created an interactive display that will enlighten young minds, providing the museum with an educational exhibit which shares a concept not currently taught by any other. Our project …

Clueless: Revolutionizing Sustainable Fashion And Combating Overconsumption, Tanya Ravichandran

Graphic Communication

“Clueless” revolutionizes sustainable fashion by combating wardrobe overconsumption and the industry’s carbon footprint, using AI to suggest personalized outfits from existing wardrobes tailored to weather and wear history. It enhances user engagement through features like outfit ‘shuffle’ and provides insights into wardrobe utilization and carbon impact.

It’s more than an app; it’s a step towards a greener wardrobe and a healthier planet.

Electronic Note-String Detector, Gavin Garcia-Rossi, Tommy Smail

Electrical Engineering

As the virtual space has become a dominant part of everyone’s day-to-day lives, many normal face-to-face interactions and services have not yet been facilitated by adapting technology. One of these prevailing areas is music lessons. Over Zoom meetings, or other virtual platforms, it is tremendously challenging to teach students. These challenges include recognizing student mistakes audibly and visually, and being able to give confident feedback on the incorrect notes played by learning musicians. Without having to delve into improving the complex systems that would be required to improve audio, video, and connection quality of these connections, we have another solution …

Complex Dimensions Of 100 Different Sierpinski Carpet Modifications, Gregory Parker Leathrum

Master's Theses

We used Dr. M. L. Lapidus's Fractal Zeta Functions to analyze the complex fractal dimensions of 100 different modifications of the Sierpinski Carpet fractal construction. We will showcase the theorems that made calculations easier, as well as Desmos tools that helped in classifying the different fractals and computing their complex dimensions. We will also showcase all 100 of the Sierpinski Carpet modifications and their complex dimensions.

The Tidal Prism, Viable Eelgrass Habitat, And The Effects Of Sea Level Rise In Morro Bay, Kaden A. Caliendo

Master's Theses

The tidal prism, or the volume of water exchanged from the sea to an estuary from mean low to mean high tide, influences system hydrodynamics and ecological functioning. Since 1884, the tidal prism in Morro Bay, California has been estimated to be decreasing over time due to sedimentation from upstream practices. What is the current tidal prism in Morro Bay and how will that change with sea level rise? How will eelgrass respond to rising sea levels?

For this study, inexpensive tidal gauges were deployed at four locations in Morro Bay from March to August 2023 to measure spatially varying …

The Construction Of Khovanov Homology, Shiaohan Liu

Master's Theses

Knot theory is a rich topic in topology that studies the how circles can be embedded in Euclidean 3-space. One of the main questions in knot theory is how to distinguish between different types of knots efficiently. One way to approach this problem is to study knot invariants, which are properties of knots that do not change under a standard set of deformations. We give a brief overview of basic knot theory, and examine a specific knot invariant known as Khovanov homology. Khovanov homology is a homological invariant that refines the Jones polynomial, another knot invariant that assigns a Laurent …