Other Physical Sciences and Mathematics Commons^™

(R2150) Impact Of Specialist Predator Harvesting On The Stability Of A Three-Species Food Chain Model With A Generalist Predator, S. Ganga, S. Vijaya

Applications and Applied Mathematics: An International Journal (AAM)

In this study, the stability of a three-species food chain model comprising a prey, an intermediate specialist predator, and a top predator exhibiting generalist behavior is examined, with harvesting applied to the intermediate predator. The main objective is to investigate how variations in the harvesting rate influence system stability and the coexistence of all three species. The positivity, boundedness, and equilibrium points of the model are analyzed to ensure biological feasibility. The equilibrium point involving the prey and the top predator satisfies the criteria for both local and global asymptotic stability. The coexistence equilibrium point attains local asymptotic stability based …

Improving The Electrochemical Properties Of Mno2 By Doping With Fe For Water Splitting And Supercapacitor Application, Joseph Okwe

Electronic Theses & Dissertations

An Abstract of the Thesis by

Joseph Okwe

These days when the issue of energy is talked about, it is usually more than just the usefulness of different types of energy. This topic now encompasses ways of generating and storing energy in the most efficient and sustainable way. For this reason, various research has shown that materials that are fabricated for the purpose of energy storage and conversion also find applications in other areas such as water splitting and supercapacitors. And so certain materials, when synthesized, can serve more than one purpose in either generating or storing energy. This project …

Modeling Flood Risks For Small-Scale Coastal Watershed Across Shared Socioeconomic Pathway Scenarios, Sebastian Loschner

Graduate Theses and Dissertations (2019 - present)

Coastal flooding, driven by the mixture of natural processes and human activities such as precipitation, waves, sea level rise, and urbanization, remains a growing concern. While recent flood-risk studies use IPCC's Shared Socioeconomic Pathways with climate projections to assess future flood exposure, smaller coastal watersheds, < 120,000 acres, remain insufficiently studied. Projected sea level rise is expected to intensify these impacts in smaller systems, potentially causing more severe flooding than reported for larger watersheds. To address this gap, this study used the SRH-2D model integrated with Aquaveo's Surface-water Modeling System to simulate flooding in the lower Fish River basin, Alabama. A coastal watershed sensitive to both riverine and tidal influences. Simulations tested different sea levels based on SSP scenarios corresponding to low, moderate, and high emissions for the years 2050 and 2100. Results indicate that the midcentury scenarios remained even in inundation extent and volume, between 9.9-10.4% compared to the 2020 baseline, the latter scenarios had a wider range in results of between 25.9-50.3% compared to the same baseline. Across scenarios, the most vulnerable and inundated areas of the smaller coastal watershed were the narrow points where upstream flow convene with downstream backwater. These findings highlight the need for futuristic location-specific flood mitigation strategies.

Solution Of Fractional Order Diffusion Equations With Clique Neural Network, Merve Zeynep Kaya, Mesut Karabacak, Ercan Çelik

Mathematical Modelling and Numerical Simulation with Applications

In this paper, the clique artificial neural network method is used to solve the fractional diffusion equation, which is a subclass of partial differential equations. The clique neural network architecture is constructed using input, hidden, and output layers. Several degrees of clique polynomials were used as activation functions, and the output layer was obtained by multiplying them with weight coefficients. Subsequently, the optimization equation was derived, and the exact solution, numerical solution, and error function graphs were obtained using a specialized algorithm. Analysis of the results demonstrates that the clique artificial neural network method provides quicker and more accurate results …

Hindcasting The Occurrence Time Of Major Earthquakes Using Machine Learning And Time Series Analysis, Rubidha Devi D

Theses and Dissertations

An earthquake is an intense shaking of the ground that typically occurs when tectonic plates move beneath the surface of the Earth. Scientists analyze historical seismic records and geophysical and atmospheric signs to build models estimating the probability of major earthquakes by detecting patterns and anomalies in data such as ground deformation and seismic waves. This study would help in predicting earthquakes to minimize risks of people and buildings.

The present study investigates the devastating earthquakes along the Chilean subduction zone in South America, linking non-seismic data to machine learning predictions of Outgoing Longwave Radiation (OLR) and Relative Humidity (RH) …

Bridging Scales In Epidemic Modeling From Individuals To Networks And Ecosystems, Saiprasasd Vr

Theses and Dissertations

Epidemics have shaped the trajectory of human history, repeatedly exposing vulnerabilities in healthcare systems and influencing socio-economic dynamics on a global scale. The COVID-19 pandemic, in particular, underscored the pressing need for flexible and responsive modeling framework capable of adapting to dynamic and evolving epidemic scenarios. Motivated by these challenges, this thesis explores the development of innovative epidemic models that integrate classical mathematical modeling techniques, network-based frameworks, and modern data-driven approaches. Each chapter addresses a distinct dimension of epidemic spread, from vaccination dynamics and community coupling to ecological complexity and adaptive human behavior, culminating in a model-free paradigm suitable for …

An Exploration Of The Structure Of The Linear Algebraic Model Of Color, Isaac Martin

University Honors Theses

This thesis surveys the mathematical grounding of linear algebraic models of color. It aims to build from the ground up the framework by which additive color is broadly understood in the digital age. Primarily building on the work of Jozef Cohen, Eric Dubois, David H. Krantz, and Günter Wyszecki, it aims to chart the construction of a model of color that underpins most modern understandings of color. While the construction is certainly established in colorimetric circles, the construction is, in the thesis author's opinion, either obtuse or non-rigorous. Ideally, this thesis serves to make the construction accessible to an audience …

Writing Climate Change: Science Knowledge In Creative Forms; Part Two: From Reading To Writing, Lytton Smith

Climate Change and the Individual, 2025-26

This lesson explores how a short creative piece by Ada Limón, U.S. Poet Laureate, draws on climate science knowledge to engage readers informationally, imaginatively, and emotionally. Students will reflect through discussion and/or writing on both the scientific methodology and the questions of equity and justice her poem raises. Finally, students will engage in a guided writing prompt where they research science knowledge around climate change and use what they find to shape their own short creative pieces (100-300 words), based in that science.

Writing Climate Change: Science Knowledge In Creative Forms; Part One: Understanding Science Stories, Lytton Smith

Climate Change and the Individual, 2025-26

This lesson explores how a short creative piece by Ada Limón, U.S. Poet Laureate, draws on climate science knowledge to engage readers informationally, imaginatively, and emotionally. Students will reflect through discussion and/or writing on both the scientific methodology and the questions of equity and justice her poem raises. Finally, students will engage in a guided writing prompt where they research science knowledge around climate change and use what they find to shape their own short creative pieces (100-300 words), based in that science.

Benchtop-Scale High Temperature Molten Salt Electrochemical Reactors: Experimental Setup And Considerations, Haley Hoover, Ivy Wu, Oluwatamilore Olushina, Robert Bell, Kerry Rippy

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

Molten salt electrochemical reduction (MSER) is the dominant production method for aluminum and titanium, and emerging technologies for producing other commodity metals with these highly electrified techniques have demonstrated promising results. However, the scale up of MSER of materials such as iron and silicon are limited by the challenging issues of materials compatibility and impurity control. This work describes an experimental MSER setup using both chloride and carbonate salts. This setup is designed for operations outside of a glovebox, which is practical from an industrial perspective, but creates unique challenges. This work serves as a practical guide to discuss some …

Factors Influencing Student Motivations And Experiences In Stem Course Office Hours, Gabriella R. Dauber, Jeremy L. Hsu

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Office hours are a part of nearly all science, technology, engineering, and mathematics (STEM) courses, with many academic and affective benefits for students who attend. However, despite their ubiquity, there has only been limited past work examining the sources of knowledge students draw from to shape their perceptions of office hours, as well as the factors that influence students' experiences in STEM course office hours. Here, we conducted semistructured interviews with 20 students enrolled in an introductory STEM course to investigate what motivates students to attend STEM course office hours, the factors that shape their experiences in office hours, and …

Towards The Signed Decomposition Of Young Quasisymmetric Schur Functions Into Dual Immaculate Quasisymmetric Functions, Gavin Butts, Joshua Hallam

Honors Thesis

We introduce a family of descent-preserving, sign-reversing involutions on encodings of standard immaculate tableaux which, in the two-row case, identifies pairs standard immaculate tableaux, leaving exactly those satisfying the conditions of standard Young composition tableaux fixed. Using this result, we derive the first explicit signed decomposition of the Young quasisymmetric Schur functions into dual immaculate quasisymmetric functions, confirming the conjectured decomposition, by Allen-Hallam-Mason, in the two-row setting. Along the way, considering the number of descent elements, we obtain counted refinements of standard immaculate tableaux and standard Young composition tableaux with shapes (n,n+1) and (n+1, …

The Impacts Of The Transfer Process Through The Eyes Of Stem Majors, Astrid Y. Lopez Matias

Honors Theses

This study explores the experiences of science, technology, engineering, and math (STEM) transfer students through the lens of Lily, a biology major who transferred from a large Midwestern university to a large Southeastern university. Employing a qualitative case study approach, data were collected via a semi-structured interview to delve into the complexities of her transfer journey. The analysis was guided by the Edalgo and High (2022) framework, which examines the interplay of personal, institutional, and social factors in shaping student experiences.

Lily's narrative highlights several challenges common among STEM transfer students, including unexpected personal and financial pressures, difficulties in navigating …

Representation And Formalization Of Relation Algebras, Pace S. Nelson, Peter Jipsen

Student Scholar Symposium Abstracts and Posters

Abstract relation algebras were defined by Alfred Tarski in 1941 to capture the algebraic properties of binary relations. An interesting question is whether a given relation algebra is representable as an algebra of binary relations. Donald Monk proved in 1964 that the theory of representable relation algebras is not finitely based, and Robin Hirsch and Ian Hodkinson in 2001 showed that it is an undecidable problem whether a finite relation algebra is representable. However, Roger Maddux’s concept of n-dimensional bases and Steve Comer’s one-point extension method can prove (non)representability for various small algebras. Both methods are based on a two-player …

The Human Legacy: Agriculture, Civilizations, Strife, And Pandemics Changing Our Climate, Jacalyn M. Wittmer Malinowski

Climate Change and the Individual, 2025-26

For most of human history, climate has shaped our lives, while our influence on it remained minimal. However, the notion that early humans had no measurable impact on the climate before industrialization is inaccurate. Early in human history, activities – such as the rise of agriculture, the growth of civilizations, periods of conflict, and pandemics – altered greenhouse gas levels in the atmosphere. These changes contributed to significant periods of climate change long before the burning of fossil fuels set us on the path to today’s global climate crisis.

The Role Of The Neutral Wind In Observations Of High-Latitude Ionospheric Energy Transfer, Andrew M. Pepper

All Dissertations

Joule heating results from the collisional interaction between ions and neutrals and serves as a crucial mechanism for energy transfer between Earth's magnetosphere and ionosphere-thermosphere system, particularly at high latitudes. This dissertation investigates the modulation of Joule heating by altitude-resolved neutral winds, electric fields, and conductivity variations through multi-instrument observational analysis and modeling that incorporates both in-situ and ground-based sources to measure the main drivers of ion-neutral coupling. The observations presented consistently demonstrate a dual regulatory effect of the neutral wind on energy deposition that varies systematically with both geomagnetic activity level and proximity to auroral boundaries. In regions characterized …

The Petm: A Window Into Earth's Future Climate, Jacalyn M. Wittmer Malinowski

Climate Change and the Individual, 2025-26

The Paleocene-Eocene Thermal Maximum (PETM) is not just an event that occurred in Earth’s distant past (~55 million years ago) but is a crucial lesson for today’s meteoric climate change. The PETM offers a historical parallel of rapid flux of greenhouse gases into the atmosphere that caused global warming, ocean acidification, dramatic changes in weather, and extinctions. This global warming event was the result of 20,000 years of “rapid” warming (in geological terms) however, we are experiencing rates of warming that are 5-10x higher than PETM levels. We are not experiencing rapid warming today, in comparison to the past, we …

Kelp Guardians Can Save The World: A Food Sovereignty Lab Report Of The Ghvtlh-K’Vsh Shu'-Srnelh-'I~ (Kelp Guardians) California Sea Grant, Delaney A. Schroeder-Echavarria

Cal Poly Humboldt theses and projects

As partners of the Ghvtlh-k’vsh Shu'-srnelh-'i~ (Kelp Guardians) California Sea Grant project, the Rou Dalagurr Food Sovereignty Lab and Traditional Ecological Knowledges Institute has actively engaged with local educators, Tribal organizations, and Tribal Nations to create youth-centered curricula, researched through a community-based participatory research lens. This is demonstrated through an innovative approach to recruiting and retaining Indigenous youth and community interest in coastal and marine ecosystems and resources by connecting with Indigenous cultural practices, Indigenous sciences, and community-based programs to encourage future careers. The Kelp Guardians project is led by the Tolowa Dee-ni’ Nation (TDN or Nation) and includes various …

Forensic Characterization And Comparison Of Modern Nail Polish Products By Their Physical Features And Chemical Composition, Madison Meredith Lindung

Graduate Theses, Dissertations, and Problem Reports (ETD)

Nail polish can serve as valuable evidence in forensic investigations as it is often found on the hands and feet of individuals. Nail polish can break off and transfer easily during self-defense actions or forceful contact, such as in cases of kidnapping, sexual assault, or homicide. These residues can provide clues about who was at the scene, as well as where, when, and how the event evolved. However, compared to other types of paints commonly analyzed in forensic laboratories, limited forensic research has been conducted on the chemical composition and discrimination capabilities of popular nail products. The lack of information …

Characterizing The Earth's Magnetosheath With In Situ Measurements, Hector A. Salinas

Physics Dissertations - Archive

Earth’s magnetosheath is a region of shocked plasma that mediates energy and momentum transfer from the solar wind to the magnetosphere. The dynamics and thus the plasma structures of this region are highly dependent on upstream solar wind conditions. As such, the region is often characterized as a turbulent environment, with the most intense periods of turbulence occurring often under quasi-parallel bow shock conditions. This magnetosheath turbulence displays as variable and large-scale fluctuations with in-situ measurements. Given that turbulence is a characteristic feature of the magnetosheath, this dissertation asks two questions: (1) How are plasma structures inside the sheath affected …

“Regression To The Mean”: The Confluence Of Eugenics And Statistics In The 19th And 20th Centuries, Emrys G. King

Pomona Senior Theses

The work of this thesis is twofold — first, qualitatively characterizing the confluence between the British eugenics and statistics movements in the late 19th and early 20th centuries, and second, quantitatively analyzing the effect of this foundation on pedagogical materials in the growing field of statistics between 1880 and 1970. Towards the first goal, the history of the method of least squares, state statistics, and positive and negative eugenics are outlined, followed by a close reading of the foundational texts authored by Francis Galton and Karl Pearson that introduced linear regression. Towards the latter goal, English-language statistics textbooks published between …

Determination Of Spatial Origin Of Striations On Fired Projectiles, Kaitlin A. Dolan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Firearms examination has been a mainstay of Forensic Science for over a century. One of the principal assessments performed by firearm examiners is the comparison of fired projectiles to a suspect firearm. The AFTE theory of identification, as it pertains to firearms and toolmarks, supports the basis that the barrel of a firearm will impart class and individualizing characteristics onto the fired projectile. The characteristics are developed by the interaction of the projectile surface with the lands of the barrel. Features on the lands, which are incidental to the process of manufacturing, dictate the characteristics observed on the fired projectile. …

Modeling Neighborhoods As Fuel For Wildfire, Bryce Alan Young

Graduate Student Theses, Dissertations, & Professional Papers

Wildfire models drive billions of dollars in risk mitigation efforts. However, the modeling community currently lacks a representative fuelscape on which to base simulations of fire spread in the built environment and the wildland-urban interface (WUI) where vegetation and structures act together as fuel for wildfire. This thesis advances wildfire risk modeling by addressing the underdeveloped representation of the built environment in existing frameworks. By identifying inconsistencies in how structure and defensible space features are defined and used across empirical studies, predictive indices, and fire spread models, this research lays the groundwork for standardized modeling approaches and feature selection (Chapter …

Unh/Noaa Joint Hydrographic Center 2025 Performance And Progress Report Executive Summary, Larry A. Mayer

Center for Coastal and Ocean Mapping

No abstract provided.