Digital Commons Network^™

Determining The Electric Field In A 10 Ns Pulsed Plasma In Fuel-Air Mixtures Using Efish, Md Ziaur Rahman, Christopher J. Kliewer, Brian D. Patterson, Chunqi Jiang

Bioelectrics Publications

Transient plasma ignition (TPI) utilizes non-equilibrium plasmas, produced by nanosecond high-voltage pulses, to improve lean-fuel combustion performance and reduce emission. It is known that the relatively high reduced electric field (E/N) in TPI plays an important role in generating energetic electrons and facilitating energy-efficient radical productions, resulting in reliable ignition for lean combustion. Determining the reduced electric field in the discharge is hence important for the understanding of the TPI process and ultimately allowing for the control of the plasma chemistry. This study reports spatiotemporally resolved measurements of the electric field (E) in a 10 ns pulsed plasma that is …

Ammonia Synthesis By Nanosecond Pulsed Atmospheric Pressure Plasma Jets Impinging On Water, Zach Caudell, Lynnet Rich, Olga Pakhomova, Chunqi Jiang

Bioelectrics Publications

Developing energy-efficient technologies for carbon-neutral ammonia (NH₃) synthesis is critical for decentralized fertilizer production and global decarbonization. This study investigates generating NH₃ from water using a nanosecond pulsed atmospheric pressure plasma jet (ns‑APPJ) operating in either N₂ or dry air. The plasma jet reactor employed approximately 250 ns, up-to-22 kV pulses at 500 Hz to sustain a nonequilibrium discharge impinging directly on static liquid water. The kinetics, energy efficiency, and product selectivity of NH3 formation were quantified as functions of the pulse voltage, repetition frequency (PRF), and gas flow rate. NH₃ production increased linearly with treatment time and scaled strongly …

Geographic Variation In Proteomic Responses To Ocean Acidification In A Cold-Water Coral (Balanophyllia Elegans), Keana A. Richmond

Cal Poly Humboldt theses and projects

In the face of a rapidly changing climate, assessing organismal responses to future stressors in the context of current, natural exposure to stress could provide key insights to understanding marine ecosystem resilience. I used Balanophyllia elegans, a cold-water, solitary, azooxanthellate coral as a model to better understand how varying oceanographic conditions across its geographic range have shaped its ability to tolerate and potentially adapt to current and future ocean acidification conditions. I collected B. elegans individuals from four sites across 2,500km of their range and subjected them to two pH treatments to investigate site-specific protein expression in response to …

"What Power Do We Have?" Community Capacity And Justice In Samoa, California’S Floating Offshore Wind Terminal Development, Lauren Mccall Hart

Cal Poly Humboldt theses and projects

Floating offshore wind (OSW) is a relatively novel technology in the United States, which is positioned to play an integral role in California’s decarbonization strategy. Two federal OSW lease areas have been established off the coast of Northern California, and plans are underway to develop supporting port infrastructure, including the Humboldt Bay Offshore Wind Heavy Lift Marine Terminal (HLMT). The proposed HLMT site is adjacent to communities on the Samoa Peninsula of Humboldt Bay, which currently face socio-environmental vulnerabilities and critical infrastructure gaps. The social implications of OSW port development remain poorly understood, particularly in rural and underserved communities. This …

Depth And Soil Physical Context Govern Soil Organic Carbon, While Woody Cover Moderates Native Vegetation Relationships In California Rangelands, Dabid Zuniga Garcia

Cal Poly Humboldt theses and projects

Soil organic carbon (SOC) is central to soil function and an important component of climate mitigation in rangeland ecosystems, but the controls on SOC across California’s working rangelands remain understudied. Using data from Point Blue Conservation Science’s Rangeland Monitoring Network, this study evaluated how soil properties, vegetation structure, and recent climate relate to SOC concentration at depths of 0–10 cm and 10–40 cm across 145 ranches spanning four California regions. Linear mixed-effects models showed that SOC was consistently higher in topsoil than subsoil and highest in coastal sites relative to interior valleys. Bulk density was the strongest negative predictor of …

Ai Deployment Authorisation: A Global Standard For Machine-Readable Governance Of High-Risk Artificial Intelligence, Daniel Djan Saparning

Student Publications

Modern artificial intelligence (AI) governance lacks a formal, enforceable mechanism for determining whether a given AI system is legally permitted to operate in a specific domain and jurisdiction. Existing approaches-such as model cards, audits, and benchmark evaluations provide descriptive information about model behaviour and training data but do not produce binding deployment decisions with legal or financial force. This paper introduces the AI Deployment Authorisation Score (ADAS). This machine-readable, regulator-grade framework evaluates AI systems across five legally and economically grounded dimensions: Risk, Alignment, Externality, Control, and Auditability, derived from safety engineering, alignment theory, algorithmic accountability, and liability economics. ADAS produces …

Reversible Fluorescence Quenching And Recovery In Pvp-Supported Copper Nanoparticles, Sara Rayan

Senior Honors Theses and Projects

Copper nanoclusters stabilized by polyvinylpyrrolidone (PVP) exhibit unique fluorescence properties that are highly sensitive to changes in their chemical environment, making them promising candidates for sensing applications. This study investigates the reversible fluorescence quenching and recovery behavior of PVP-supported copper nanoparticles in response to iron(III) ions and evaluates the selectivity of this response across different chemical conditions. Fluorescence quenching was examined using Fe³⁺ introduced as FeCl₃, followed by recovery experiments using ascorbic acid to assess reversibility through redox-driven interactions. To determine whether the observed response is specific to iron, potassium ferricyanide was used as an alternative Fe³⁺ source. Additional comparisons …

Investigating The Effects Of Atg3 On Autophagosome Size And Number, Keeran R. Senthil Kumar

Senior Honors Theses and Projects

Macroautophagy, or autophagy, is a highly conserved catabolic process in all eukaryotes which allows for the degradation of large cytosolic contents. It occurs in two forms: bulk autophagy, which is induced by nutrient deprivation and targets nonspecific cargo, and selective autophagy, which is induced by cellular stress and sequesters specific substrates. The process of autophagosome formation is carried out by a group of Atg (autophagy-related) proteins, one of which is Atg3. Atg3 functions as an E2-like enzyme by conjugating Atg8 — a ubiquitin-like protein — to phosphatidylethanolamine (PE), a step required for autophagosome membrane formation. This lipidation process is catalyzed …

Efficient Organic Molecular Crystal Structure Prediction Using The Density Functional Tight-Binding Method, Maureen M. Kitheka, Yan Jing, Yan Yao, Puja Goyal

Faculty Publications – Chemistry

Over the years, computational crystal structure prediction (CSP) for organic molecules has thrived as an area of research, spanning various scientific disciplines and having significant applications in industries such as pharmaceuticals and agrochemicals. Within the field of batteries, redox-active organic materials (ROMs) such as quinones have received increased attention as promising electrode materials for rechargeable batteries. However, experimental determination of the crystal structure of intermediate species formed during the discharge/charge cycle can often be challenging. Incomplete X-ray diffraction patterns can also lead to difficulties in crystal structure determination for ROMs used in batteries. Use of a semiempirical electronic structure method …

Detecting And Repairing Conflicting Constraints In Co-Trained Physics-Informed Neural Networks For Composite Curing Processes, Cooper J. Evans

Dissertations, Master's Theses and Master's Reports

Composite materials have become a critical component of modern manufacturing, especially in the automotive and aerospace industries. The curing process for these composites has been modeled using a variety of partial differential equations representing the heat transfer and composite curing kinetics. Optimizing the applied temperature profile is critical for maximizing the efficiency and capacity of composite part manufacturers. Constraints must be placed on the inputs and outputs of the model, including but not limited to, the applied temperature profile, part temperature, and final degree of cure. Conflicting sets of constraints are easy to unknowingly impose due to the highly coupled …

Learning Without Training, Ryan O'Dowd

CGU Theses & Dissertations

We live in an era of big data. Whether it be algorithms designed to help corporations efficiently allocate the use of their resources, systems to block or intercept transmissions in times of war, or the helpful pocket companion known as ChatGPT, machine learning is at the heart of managing the real-world problems associated with massive data. With the success of neural networks on such large-scale problems, more research in machine learning is being conducted now than ever before. This dissertation focuses on three different projects rooted in mathematical theory for machine learning applications. Common themes throughout involve the synthesis of …

On The Influence Of Faraday Waves On Transport In Resonant Acoustic Mixing, Preston David Silverstein

CGU Theses & Dissertations

Resonant acoustic mixing (RAM) uses low frequency high acceleration oscillatory forcing to combine fluids, particles, and powders. Although progress has been in adjacent RAM fields, there are still gaps in understanding how Faraday surface instabilities affect momentum transport to the bulk fluid and particles therein. This work investigates the energy pathways that an oscillatory mixer has and connects surface deformation to bulk rotational flow and particle forcing. This study is conducted in three phases. In phase 1, a thermodynamic first- and second-law analysis couples the surface features with the scale of subsurface rotational features. Experimental surface measurements showed that for …

Asymptotics Of Discrete Convolution Powers And Applications To Difference Schemes, Pedro Henrique Alves Silva Dos Santos

Honors Theses

In this thesis we provide Gaussian Estimates and Local Limit Theorems describing the asymptotic behavior of convolution powers of a class of complex-valued functions on $\mathbb{Z}^d$. Convolution powers arise naturally in the study of partial differential equations, as well as in random walks in probability theory. In particular, they are connected to the stability theory of difference schemes used to approximate solutions to partial differential equations. We take inspiration from the work of Vidar Thomée on stability theory to restrict our attention to convolution powers of functions whose Fourier Transforms satisfy certain local expansions. We then combine the Cauchy Integral …

Metamorphosed Components In Cv Chondrites Camel Donga 003 And Camel Donga 040 As Evidence For Varying Degrees Of Metamorphism Within The Parent Body, Kathryn E. Stone

Honors Theses

The CV carbonaceous chondrites are a group of primitive stony meteorites that record early solar-system evolution processes. They are typically of low metamorphic grade, though some metamorphosed CVs have recently been found. Two CV chondrite breccias, Camel Donga 003 (CD 003) and Camel Donga 040 (CD 040) consist of multiple lithologies. CD 003 consists of three lithologies, one of which – Lithology C – has been metamorphosed to petrologic type ~3.7 (Alevy et al. 2025). CD 040 consists of two lithologies, one of which is metamorphosed to petrologic type 3.7 (Dunn and Alevy, 2024; Dunn et al. unpublished). Both samples …

Three-Photon Rydberg Eit Lineshape Analysis In Rubidium, Jackson Lake

Honors Theses

Electromagnetically Induced Transparency detection of high-lying Rydberg states in room-temperature rubidium vapor was investigated using a four state ladder-type excitation scheme with light provided by three External Cavity Diode Lasers (ECDLs) at 780 nm, 776 nm, and 1266 nm. This detection technique was studied by characterizing the lineshape parameters of the EIT transmission peak, specifically the height, width and area of the transparency window as functions of the dressing and coupling laser powers. With the goal of characterizing the linewidth of the transmission signal, a confocal etalon was built and implemented in the optical setup to perform frequency calibration of …

Enumerating Matrices Of A Given Order Over Finite Fields, Thor Richard Gabrielsen

Honors Theses

This thesis derives a generating function that describes the matrices of a given multiplicative order over finite fields of a given order assuming that the order of a field is not a divisor of the desired order of the matrix. This is done by using the power series known as the cycle index derived from the rational canonical form. This index can be factored, and using the fact that the minimal polynomial divides some polynomial of the form x^k − 1 we can show that the minimal polynomial is squarefree. This sufficiently restricts the form of the rational canonical form …

Analyzing Rydberg Atoms Of Rubidium At Room Temperature: Applying Electromagnetically Induced Transparency, Bridger Stiles

Honors Theses

This thesis describes an experimental exploration of electromagnetically induced transparency (EIT) in atoms of 85Rb using a new MOGLabs external cavity diode laser. A two-step ladder technique of EIT was applied using a 5S_1/2→5P_3/2 probe transition and 5P_3/2→nD_5/2 coupling transitions. Significant apparatus tuning was done, including developing a reliable procedure of regulating frequency and scanning the coupling laser over a sufficient mode-hop free range. A Doppler-reduced technique was applied by counter-propagating the probe and coupling beams through the Rb vapor cell. EIT signals were collected at various probe and coupling laser powers to analyze changes in signal size and linewidth. …

Gradient-Based, Post-Optimality Sensitivity Analysis With Respect To Parameters Of State Equations, Gene Hou, Jonathan Degroff

Mechanical & Aerospace Engineering Faculty Publications

Design optimization is a computational tool that can enable a designer to investigate the effectiveness of a design concept in an organized format. However, this design process requires the design variables, constraints, and objective function to be properly defined and expressed in mathematical forms. Post-optimality analysis thus becomes a necessary step to investigate different variations in the problem formulation and parameters to ensure that optimization produces a stable and trustworthy outcome. One efficient way to achieve this aim is to compute the local derivative of the optimized objective function with respect to the optimization problem parameters, such as bounds on …

Uncertainty-Aware Estimation, Planning, And Control For Tracking Multiple Drifting Patches In Flow Fields, Daniel O. Akanji, Krishnanand N. Kaipa, Cong Wei

Mechanical & Aerospace Engineering Faculty Publications

In this study, we present a replay-based framework for uncertainty-aware persistent tracking of multiple advected surface patches using an autonomous marine vehicle operating in spatiotemporal-varying currents. The method combines three components: local flow estimation, covariance-aware patch-boundary propagation with intermittent boundary fusion, and mission-level scheduling over multiple patches. Each patch is represented by a polygonal boundary, whose vertices are propagated through the estimated flow field while carrying per-vertex covariance, thereby quantifying uncertainty growth during advection. A flow-aware gain-scheduled linear quadratic regulator (LQR) was designed to shape the desired surge speed to take advantage of favorable currents. When the vehicle services a …

Mechanical-Medical Convergence In Heart Failure: Artificial Intelligence, Finite-Element Modeling, And 3d Printing For Diagnosis And Prognosis, Quazi Noor E. Sabrina, Quazi Md Zobaer Shah, Quazi Noor E. Sohela, Md Mahabub Hasan Mousum, Md. Moyeen Uddin Chisty, Quazi Md. Akbar Shah

Mechanical & Aerospace Engineering Faculty Publications

Heart failure remains a leading cause of global morbidity and mortality, yet routine clinical indices often miss the regional biomechanical disturbances that drive progression and shape treatment response. This State-of-the-Art review examines how finite-element (FE) modeling, additive manufacturing, and artificial intelligence (AI) are converging to improve the diagnosis, phenotyping, procedural planning, and prognostic assessment of heart failure (HF). Although these technologies have matured in structural heart disease and transcatheter intervention research, their greatest translational potential may lie in HF, where patient-specific ventricular remodeling, myocardial stress–strain heterogeneity, valve-ventricular coupling, and device-tissue interaction are incompletely captured by conventional clinical indices. We synthesize …

Radical-Based Oxidative Pretreatment Enhances Biofuel Production From Lignocellulosic Biomass Via Hydrothermal Liquefaction, João Vitor Dos Santos, Louis C. Bondurant, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

The sustainable production of biofuels from lignocellulosic biomass is a central goal in the transition to low-carbon energy systems. However, hydrothermal liquefaction (HTL), a promising thermochemical conversion pathway, is constrained by the high oxygen content and complex aromatic structure of lignin, which lowers bio-oil quality. Here, we used a model system of brown-rot-degraded white oak (Quercus alba) to test whether radical-based oxidative pretreatment could enhance HTL performance by converting lignin into more aliphatic intermediates. Oxidation was performed under simulated Fenton conditions using fixed Fe(II) (60 ppm) and two hydrogen peroxide concentrations (3 and 8 M), resulting in extensive lignin depolymerization …

Twenty-One Years Of Global Atmospheric Chlorine Inventories From Atmospheric Chemistry Experiment Fourier Transform Spectrometer (Ace-Fts) Measurements, N. Raymond, P. Bernath, C. Boone, M. P. Chipperfield

Chemistry & Biochemistry Faculty Publications

We present atmospheric chlorine inventories over 21 years (2004-2024) and five latitude bands (82-60°N, 60-30°N, 30°N-30°S, 30-60°S, 60-82°S) across altitudes from the surface up to 61 km. These inventories were calculated using the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS) version 5.3 retrievals of the volume mixing ratios (VMRs) of 13 chlorine-containing species. Of these, five are product gases: HCl, HOCl, ClONO₂, COClF, COCl₂, and eight are source gases: CCl₄, CH₃Cl, CFC-11 (CCl₃F), CFC-12 ( CCl₂F₂), CFC-113 (CClF₂CCl₂F}), HCFC-22 (CHF₂Cl), HCFC-141b ( C₂H₃Cl₂F), and HCFC-142b (C₂H₃}Cl₂F). Where necessary, ACE-FTS data were supplemented with data from the TOMCAT 3-D chemical transport model, …

Scanning Electron Microscopy As A Potential Tool For Distinguishing Charcoal From Dark, Oxidized, Biomass, João Vitor Dos Santos, Aleksandar I. Goranov, Lais Gomes Fregolente, Joao Marcos De Lima-Faria, Diego Stefani Teodoro Martinez, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

Condensed aromatic carbon (ConAC) is widely used as a proxy for organic materials derived from biomass burning. However, recent evidence shows that ConAC can be also formed through nonpyrogenic oxidative processes. This study presents a proof-of-concept investigation using scanning electron microscopy (SEM) to distinguish charcoal from dark, ConAC-rich materials produced by ambient oxidation of biomass. Pine wood exposed to long-term iron-mediated oxidation was compared with unaltered wood and a controlled laboratory-generated charcoal reference. Conventional geochemical analytical methods, including benzenepoly(carboxylic acid) (BPCA) analysis, Fourier transform–ion cyclotron resonance–mass spectrometry (FT-ICR-MS), solid-state 13C nuclear magnetic resonance (NMR) spectroscopy, and elemental analysis, confirmed substantial …

Mechanical Property Evaluation Of Paper Die Materials In Explosive Forming, Higa Yoshikazu, Kadena Hisashi, Shimojima Ken, Iyama Hirofumi

ASEAN Journal on Science and Technology for Development

This study investigates the feasibility of using paper materials as substitutes for molds in explosive forming by systematically evaluating their mechanical properties. Tensile tests were conducted on three paper types differing in thickness and internal fiber structure, using a custom-designed gripping tool. Specimens were prepared in multiple orientations to account for anisotropic behavior. Results indicate that coated paper, exhibiting the highest specific tensile strength and energy absorption per unit basis weight, is the most suitable for formability. In contrast, thick paper, characterized by the lowest specific tensile energy absorption, offers the best dimensional accuracy. Anisotropy was observed in matte and …

Systematic Approaches To Characterizing Vulnerabilities And Enhancing Robustness Of Text And Vision-Language Models, Poojitha Thota

Computer Science and Engineering Dissertations

The proliferation of artificial intelligence (AI) across critical domains, including news summarization, privacy-policy analysis, and medical decision support, has raised growing concerns about the security and robustness of these systems against adversarial manipulation. This dissertation investigates adversarial robustness in generative AI by addressing three key research goals: (1) characterizing adversarial vulnerabilities across generative models, (2) developing systematic defenses to improve the robustness of generative models, and (3) designing deployment-time safeguards for securing LLM interactions.

Towards the first goal, we characterize adversarial vulnerabilities across text-based and multimodal systems. In abstractive text summarization, we show that inference-time perturbations can exploit lead bias …

Soil Respiration Drivers And Challenges In A Changing Environment, Olivia Rae Haas

Theses, Dissertations and Culminating Projects

This study aims to understand post agricultural forested soils (sandy loam, silt loam, and loam) and the influences that drive carbon sequestration and soil respiration flux. Duke Farms in Hillsborough NJ, has historically been utilized as an agricultural zone for farming a variety of crops. Currently the area is protected with a focus on environmental conservation and restoration of the land. This includes getting a better understanding of the forested portions of the property. Understanding the quality of forested areas is vital as they have the potential to act as a carbon sink which can mitigate the effects of climate …

Designing An Approach To Developing Students' Symbol Sense For The Derivative In Calculus, Laura E. Weinstein

Theses, Dissertations and Culminating Projects

Students often struggle to connect the conceptual meaning of the derivative with the symbolic structures of Leibniz (dy/dx) notation. Although symbol sense has been described as the coordination of mathematical concepts, signs, and objects, little is known about how instruction can purposefully support students in developing symbol sense for the derivative. This study addresses this gap by designing and examining a learning approach aimed at helping students construct the relational structures underlying derivative notation. Using design research methodology, the study engaged intact algebra, precalculus and calculus classes in a suburban New Jersey high school across iterative cycles of design, implementation, …

Experiments In Graph Structure And Knowledge Graph Embeddings, Antrea Christou, Cogan Shimizu

Computer Science and Engineering Faculty Publications

Knowledge graphs (KGs) are an established paradigm for integrating heterogeneous data and representing knowledge. As such, there are many different methodologies for producing KGs, which span notions of expressivity, and are tailored for different use-cases and domains. Now, as neurosymbolic methods rise in prominence, it is important to understand how the development of KGs according to these methodologies impact downstream tasks, such as link prediction using KG embeddings (KGEs). In this article, we examine how various perturbations of graph structures impact downstream tasks. These perturbations are sourced from how various methodologies (or design practices) would impact the model, starting with …

Classifying Surfaces With Handle Decomposition, Elizabeth Sipes

Murray State Theses and Dissertations

Among topological spaces, manifolds draw a lot of interest. An
n-manifold is a space that is locally like R^n. Manifolds of dimension 2
are called surfaces. Using handle decomposition, we decompose surfaces
into k-handles, where 0< =k< =2. Techniques such as handle sliding and
handle cancellation allow us to get a more favorable representation of
our surface. We use these tools and calculation of the fundamental group
to classify all compact surfaces.

Mapping Coastal Vegetation To Evaluate Salt Marsh Decline From 2016 To 2025 In South Carolina, Usa, Zak Henry Bartholomew

Theses, Dissertations and Capstones

Accelerating sea-level rise and storm surge events pose a substantial threat to salt marsh ecosystems, which provide critical ecosystem services. Classification and mapping of coastal vegetation through remote sensing can identify marsh dieback events and provide spatial context for patterns of marsh vulnerability. We used a multi-sensor approach that incorporated LiDAR data, multispectral imagery, and field-derived cover estimates to classify Spartina alterniflora (smooth cordgrass) dominated marsh types on Marine Corps Recruit Depot Parris Island (MCRDPI), a sea island in South Carolina, USA. In summer 2025, surveys were conducted within marsh classes to collect training and validation data. We used random …