Dose Characterization Of Galactic Cosmic Rays In The Human Brain: A Phits-Based Study With A Segmented Anatomical Phantom, Shanice N. Manning

LSU Master's Theses

Astronauts aboard the International Space Station (ISS) are chronically exposed to a complex space radiation environment composed of galactic cosmic rays (GCR), solar particles, and Earth's trapped radiation. These high-energy particles interact with spacecraft shielding, producing secondary particles that can penetrate inside and deposit energy in sensitive tissues. Although animal studies have been useful in assessing space radiation risks, anatomical and physiological differences limit their applicability to human anatomy especially neuroanatomy. To address this gap, we developed a computational framework to model radiation dose distribution within the human brain using Monte Carlo simulations in Particle and Heavy Ion Transport code …

The Limits Of Knowing: Determinism, Uncertainty, And What’S Beyond The Human Gaze, Xilong T. Zhang

Masters Theses

This essay traces a personal philosophical and artistic journey from rigid belief in scientific determinism to an evolving embrace of uncertainty, subjectivity, and computational perception. Raised in an atheist, scientifically grounded household in China, the author initially adopted Newtonian determinism and Laplace’s thought experiment of a fully predictable universe as guiding principles. These beliefs informed early artistic practices rooted in Constructivism, geometry, and rule-based aesthetics. However, a failed attempt to fully optimize life through deterministic control led to physical and mental collapse, prompting deeper exploration into Cartesian dualism, quantum mechanics, and the limits of reason. Through Heisenberg’s Uncertainty Principle and …

Examining The Accuracy Of The Omni Data In Representing Geomagnetic Storm Observations Near Earth And The Effect On Global Modeling, James T. Davis

2025 Spring Honors Capstone Projects - Archive

The accuracy of OMNI dataset being propagated to bow shock nose and used to represent geomagnetic storms is a known issue. Inaccuracies of this data bring erroneous results in scientific endeavors therefore establishing the importance of accuracy and consistency. This case study examines the accuracy of the OMNI data and data near-Earth in representing geomagnetic storms with different drivers on global simulations. This research will include examples of global magnetosphere simulations, such as SWMF, driven with two storms driven by coronal mass ejections, and one driven by a high-speed stream using OMNI data and data near-Earth to illustrate potential variations …

The Mechanics Of Angular Momentum Generation In Discus Throwing, Andreas Maheras

Track and Field Faculty Publications

Angular momentum development in the back of the ring, during the first double and first single support, is of paramount importance in discus throwing because this is where almost all the angular momentum the thrower can generate will be generated. From a purely mechanical point of view, to achieve that, the thrower should keep her arms spread apart, and also actively throw both the right leg and the left arm and shoulders CCW. Those actions will collectively contribute in slowing down the lower body, as the thrower actively chooses to pass as much angular momentum to the upper body at …

The Search For Slow Particles And Magnetic Monopoles With Nova, John Clark

Poster Presentations

Singular magnetic poles, north or south, have been theorized to exist for hundreds of years. In the modern day, the elusive singular magnetic pole still remains undiscovered. The appearance of this particle would help confirm many Grand Unified Theories, GUTs, and revolutionize our understanding of some of the fundamental forces of the universe. Fermilab's NOvA collaboration is working on ways to screen and detect magnetic monopoles and other slow-moving particles coming from outer space alongside their main mission to study neutrinos. The aim of this work is to determine and improve the Far Detector’s efficiency at identifying slow moving particles. …

Geometric Algebra For Field Theory In Curved Spacetime, Kevin Rhine

All Graduate Reports and Creative Projects, Fall 2023 to Present

Physics seeks to understand the universe by uncovering the fundamental laws that govern matter, energy, space, and time. At its heart lies the challenge of unification: finding a mathematical framework that consistently describes these interactions across all scales, from the subatomic to the cosmological.

This thesis explores geometric algebra, a mathematical language that unifies algebra and geometry, as a tool for advancing this understanding. By extending this framework to curved spacetimes, where gravity influences the structure of space and time, we investigate its ability to describe physical phenomena such as electromagnetism and general relativity. A notable contribution includes the geometric …

Signal Modeling Of High Purity Germanium Detectors, Brooke Parker Thibodeau

Honors Scholar Theses

Pulse shape analysis can be used to analyze radiation incident on a semiconductor diode detector. Finite element analysis (FEA) can be used to simulate high purity germanium detectors with user-specified geometry, impurity concentration, and bias voltage. Subsequent streamline calculation can be used to conduct pulse shape analysis for single and multiple site gamma-ray interactions within the detector volume. Cross sections of the detector can be visualized by contour plots of the electric field, drift velocity magnitude, and collection time, as well as t30 and t90 rise-time values.

Revealing Hidden Histories: A Multi-Sensor Aerial Survey For Detecting Unmarked Burials At Sinking Spring Cemetery, Abingdon, Va, Noah Hall

Electronic Theses and Dissertations

The Sinking Spring Cemetery, established in 1773 in Abingdon, Virginia, spans 11 acres and is divided by a road. The 9-acre southern section was reserved for white church members. Enslaved individuals and free people of color were buried in the smaller northern section, where few headstones remain today. This study aimed to map the unmarked graves using thermal, multispectral, and Light Detection and Ranging (LiDAR) sensors deployed on unmanned aerial systems. Graves were characterized by subtle topographic depressions mapped by LiDAR and cooler radiant temperature anomalies in thermal imagery. Thermal data collected at different times of the day and year …

Automated Radiotherapy Treatment Planning For Breast Cancer: A Robust To Ol For Global Deployment, Hana Baroudi

Dissertations and Theses (Open Access)

Breast cancer incidence continues to rise worldwide, particularly in low- and middle-income countries, where limitations in resources already constrain access to timely care. Radiotherapy is a cornerstone of breast cancer management, proven to significantly lower both recurrence and mortality. However, a growing shortage of radiation staff worldwide threatens the prompt delivery of these treatments.This thesis proposes an automated solution to address the limited accessibility of radiotherapy planning in breast cancer management by developing an end-to-end automated treatment planning model and evaluating its performance and limitations across diverse patient populations.

An automated contouring model was trained using data from 104 whole-breast …

Development Of Lineal Energy Spectrum-Based Biological Effects Models For Protons, Joseph M. Decunha, Fada Guan, David Grosshans, Zhongxing Liao, Dragan Mirkovic, Oleg Vassiliev, Radhe Mohan

Dissertations and Theses (Open Access)

In this dissertation, methods are developed and described to allow for the rapid calculation of microdosimetric spectra (specifically, lineal energy) for protons. SuperTrack, a GPU-accelerated tool for calculation of microdosimetric spectra was developed and is capable of computing lineal energy spectra up to 5000x faster than using Geant4 directly. Proton lineal energy spectra generated by SuperTrack are indistinguishable from those generated by Geant4. With SuperTrack, large libraries of lineal energy spectra for monoenergetic protons spanning 0-300 MeV have been developed. The proton lineal energy spectra calculated by SuperTrack have been compared to experimental measurements made by a tissue equivalent proportional …

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 …

An Analysis On The Time Effectiveness Of Speeding While Driving A Vehicle, Joy Skaggs

ATU Scholars Symposium

Speeding is responsible for roughly a third of all crashes, often coming at a deadly cost. The National Highway Traffic Safety Administration reports many negative consequences, such as a greater likelihood of loss of vehicle control, reduced protection equipment effectiveness, increased stopping distance, crash severity, and fuel consumption (National Highway Traffic Safety Administration, n.d.). Yet despite these costs, drivers continue to speed. In fact, in our fast paced world, speeding is so normalized that it’s uncommon to encounter a driver following the speed limit. Hawaiian psychology professor Leon James explains it best: people have twisted their definitions of speeding to …

Charging And Discharging Capacitors: Brightspace Package Of An Arithmetic Quiz, Vasiliy Znamenskiy

Open Educational Resources

Description:

This material is a quiz in the Brightspace Learning Management System (LMS). The quiz includes 10 physics problems on the topic of charging and discharging capacitors through a resistor.

The quiz assesses student understanding of key concepts, including voltage and charge of a capacitor, exponential functions, time constants, and dynamic changes in voltage and current.

Quiz problems are called in Brightspace LMS as arithmetic questions. The Problems give students random initial values to provide many quiz variants.

The quiz is appropriate for high school AP Physics or introductory college-level physics courses.

Key Features:

10-question quiz in Brightspace importable format …

Understanding Flow: An Experimental Analysis Of A Magnetohydrodynamic Fluid Pump, Quintin Yates, Emily Hawkins

Honors Thesis

When a magnetic field and electrical current are perpendicular to each other, an ionized fluid will experience a force called the Lorentz force. This force can be applied to create a pump. These pumps have potential applications in desalination and fluid systems in space. The technology is new, and still not well understood but are a potential alternative to typical mechanical pumps. This thesis develops a comprehensive experimental understanding of the fluid flow through a 3D-printed magnetohydrodynamic (MHD) pump. Lagrangian particle tracking (LPT) uses neutrally buoyant particles and a camera system to collect quantitative velocity information of a system. Particle …

Heavy Metals In Healthy Water Samples Used By Newborn In Al-Najaf Governorate, Iraq, Ban Hussein Ali, Ali Abid Abojassim

Al-Bahir

Water is essential for life, so monitoring water quality is important. This research focuses on measuring heavy metals (Lead, Pb; Cadmium, Cd; Chromium, Cr (in 14 healthy water samples of two types; bottled water and filtered water used by newborn children in Al-Najaf governorate, Iraq. Atomic absorption spectroscopy (AA-7000, Japan) was used to conduct the experimental analysis. Also, health risks parameters (non-carcinogenic and carcinogenic) due to Pd, Cd, and Cr concentrations were calculated. The results of Pb, Cd, and Cr concentrations in mg/L for bottled water samples were ranged 0.03-0.83, 0.01-0.69, and 0.01-0.76, respectively, while the range values for filter …

Preparation Of Nanoparticles And Study Of The Effect Of Some Of Their Physical Properties On Epoxy Polymer, Aya N. Abdullah, Niran F. Abeduljabbar

Al-Bahir

Nanoparticles were prepared by the laboratory thermal method from copper, magnesium, and zinc oxides. Different nanoparticles were added to epoxy at weight fractions of (0, 2, 4, 6, 8, 10) wt. %. The structural results from X-ray diffraction showed the appearance of epoxy in a random system, and when reinforced with nanopowders at higher addition ratios, we find the appearance of nanoparticles in a clear crystalline form, while the SEM results showed an increase in consistency and homogeneity with each increase in the proportions of nanoparticles, which appeared clearly during the EDX examination. The hardness of Shore type D was …

Microcanonical Analysis Of Semiflexible Homopolymers With Variable Bending Potential Width, Michael Gray

Scholars Week

I have developed an algorithm for finding phase transition in microcanonical data of simulations of homopolymers. These simulations model the behavior of homopolymers in an array of different conditions. This algorithm is generalized and can be applied to a variety of different systems. It works by taking repeated derivatives of the microcanonical entropy of the system and applying several filters, whose parameters are tuned algorithmically as well. Identification of phase transitions allows for the construction of a phase diagram.

Computational Modeling Of Astrophysical Systems, Leleya Iris Stallard

Spring Showcase for Research and Creative Inquiry

This research project focuses on the computational modeling of astrophysical systems using Femap with NX Nastran. The goal was to simulate and analyze the vibrational behavior and structural deformation of celestial bodies under different material compositions and collision conditions. Materials such as iron, granite, titanium, and models for white dwarf stars were used to investigate how varying physical properties affect the systems' dynamic responses. Both isotropic and anisotropic models were created to represent realistic astrophysical materials. Through static and modal analyses, the study explored how internal structure and material stiffness influence the reaction of celestial objects to applied forces and …

High-Latitude Ionospheric Irregularities Characterized Through Machine Learning Methods, Anna-Marie Bals

Doctoral Dissertations and Master's Theses

This study uses Machine Learning and data-driven techniques to understand plasma irregularities in high-latitude regions better. By combining observations and recent findings from modeling, the goal is to identify and classify scintillation signatures caused by different types of irregularities in the ionosphere. The focus is on irregularities from electron precipitation in the auroral oval and ExB drifts in the polar cap. Using Machine Learning tools, the study aims to distinguish between different scintillation signatures and link them to their sources, improving our ability to detect and characterize these events. Using multiple instruments and advanced filtering, the aim is to enhance …

Effect Of Niobium Dopant On Zno Thin Films Prepared Via The Sol–Gel Spin Coating Method, Kevin Alvin Eswar, Nur Fairuz Rostan, Maryam Mohamad, Rabiatuladawiyah Md Akhir, Rosfayanti Rasmidi, Muliyadi Guliling, Najwa Ezira Azhar, Irmaizatussyehdany Buniyamin, Mohd Firdaus Malek, Mohamad Rusop Mahmood, Husairi Fadzilah Suhaimi, Saifollah Abdullah

Makara Journal of Science

Thin films of zinc oxide (ZnO) and niobium (Nb)-doped ZnO were deposited on a glass substrate using the sol–gel spin coating method. Diethanolamine, isopropyl alcohol, and zinc acetate served as the stabilizers, solvent, and starting ma-terial, respectively. Niobium pentachloride was employed as the dopant source. Energy-dispersive X-ray analysis con-firmed Nb incorporation. Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and ultravio-let–visible spectroscopy (UV–Vis) analyses characterized the morphology, structure, and optics of the films, respective-ly. Both films, comprising nanoparticles, were visible in FESEM. Nb doping reduced the particle size from 44.2 nm to 35.8 nm. The XRD peaks at 31.23°, …

Gravity Tunnel Dynamics At Non-Zero Tunnel Diameters, Shafat Mubin, Walker T. Hayes

Georgia Journal of Science

A standard exercise in undergraduate mechanics derives the trajectory of a particle that has been dropped through a gravity tunnel passing through the center of the Earth as simple harmonic oscillation, assuming uniform earth density and negligible tunnel radius. We show that when the more accurate Preliminary Reference Earth Model (PREM) density profile and non-negligible tunnel radii are taken into consideration, significant deviations from harmonic oscillation are observed along with increasing or decreasing average particle speeds. Furthermore, we report that a particle traveling along a diameter perpendicular to the axis of the gravity tunnel is unable to reach the center …

Developing Real-Time, Online Beam Control Of Uhdr Irradiators To Facilitate Flash Translational Investigations, Austin M. Sloop

Dartmouth College Ph.D Dissertations

The field of radiation oncology seeks novel techniques to increase the therapeutic ratio to treat malignancies while minimizing damage and toxicities in healthy tissues. While it was observed that delivering therapeutic doses at high dose rate could elicit lower biological effects over a half-century ago, the field of ultra-high dose rate (UHDR) radiation therapy (colloquially known as FLASH RT) has seen a resurgence in recent years due to an alignment of accelerator capability, dosimetric advances, and improved biotechnological techniques. This has opened the door to studying potential underlying mechanisms such that we may leverage the effects of FLASH tissue sparing …

Doping Hybrid Photopolymerisable Glass With Bodipy Photosensitiser: An Efficient Approach To Improve Uv-Resistance, Luca Sorridente, Tatsiana Mikulchyk, Metodej Dvoracek, Mikhail A. Filatov, Izabela Naydenova, Kevin P. Murphy

Conference Papers

The development of photosensitive materials with improved performance and extended functionality is crucial for advancing holographic technologies. This study presents the modification and characterization of a recently reported photopolymerisable glass composition, focusing on achieving an optimal balance between maximizing photosensitivity of the material during recording and minimizing the impact of UV light on the performance of the recorded holographic structure. Building on these findings, the ultimate goal is to develop UV-resistant holographic optical elements for wavefront sensing in space applications. The research approach is based on introducing a photosensitiser with weaker UV absorption than the typically used in this material …

Establishing A Conventional Linac-Based Electron Flash Beam, Justin Defrancisco

Theses and Dissertations

Problems: A rediscovered radiotherapy technique, FLASH, involves increasing the dose rate to >40 Gy/s. For a given dose, FLASH is shown to decrease the normal tissue complication probability without affecting the tumor control probability. More preclinical studies are necessary to confirm and enable these desirable properties on humans. Current preclinical investigations have diverse constraints, requiring FLASH apparatuses with flexible parameters and accurate control. However, there are limited FLASH platforms available, the existing ones are costly. Our institution is not in possession of any such infrastructure. Even if available, dosimetry and beam control in FLASH are extremely lacking. There is …

Dosimetric Validation Of An Electron Monte Carlo (Emc) Algorithm For Small Cutouts And Extended Ssd’S: Assessing Emc In Small Field Dosimetry, Anil Basavaaraju

Theses and Dissertations

This thesis validates the accuracy and limitations of Electron Monte Carlo (eMC) simulations in Eclipse treatment planning systems for small-field electron dosimetry and extended source-to-surface distances (SSDs). Systematic measurements were performed using a microDiamond detector across various electron energies and field sizes. The study examines the discrepancies between measured and calculated (eMC) dose distributions, validating challenges due to lateral scatter disequilibrium and extended air gaps. Our findings provide systematic data for eMC dose calculations and demonstrate that eMC performs within clinical tolerances, with the ultimate goal of enhancing the precision and safety of radiation treatments.

Reasoning Through Change: Exploring Covariational Thinking In Student Exponential Graph Interpretation, Samantha Lynn Pearson

Honors Theses and Capstones

This study explores how life science students reason about exponential functions in the context of an introductory physics course. While exponential functions are essential in both physics and biology—appearing in scenarios like population growth and temperature cooling—students often encounter challenges in interpreting them. Using a resources framework, we examined the cognitive resources these students bring to exponential reasoning, focusing on what ideas and strategies they already possess. Our methodology involved conducting think-aloud interviews with nine students from PHYS 402. Interviews were coded using a framework informed by prior research on covariational reasoning and exponential understanding. Results show that students generally …

Scaling Laws For Diffusion In Crystallized Plasma From Molecular Dynamics, Dany Yaacoub

Theses and Dissertations

Diffusion coefficients for crystallized Coulomb plasmas are essential microphysics input for modeling white dwarf cores and neutron star crusts. Solving for diffusion coefficients require running large molecular dynamics simulations with thousands of particles over millions of timesteps. The diffusion in a crystallized plasma has been largely ignored and is often taken to be zero in stellar evolution codes. We find that not only is this incorrect, but we find that the diffusion in a crystallized plasma can be modeled completely using a universal scaling law independent of screening. Our simulations also show that the dominant mode of diffusion in a …

Quantifying The Performance Of The Sparta Toolkit For Use In Planetary Regolith Characterization Missions, Abigail S. Glover

Honors Undergraduate Theses

This research investigates the use of the Soil Properties Assessment, Resistance, and Thermal Analysis (SPARTA) Cone Penetration Tester (CPT) to quantify bulk density in lunar regolith simulant LHS-1E. Twenty-five penetration tests were conducted across five density profiles to derive slope parameters (G), which represent the rate of increase in resistance with depth. Results showed a consistent, nonlinear relationship between G and bulk density, validating the use of G slope as a diagnostic parameter and supporting the primary hypothesis that SPARTA CPT measurements vary meaningfully with density. Compared to prior work by Lucas et al. (2024), G values from SPARTA were …

Scp 231 Dictionary + Example Problems [General Physics 1], Daniel Capic

Open Educational Resources

Student-written definitions of key physics concepts that appear in SCP 231. There are also student-written word problems with links to instructor-created video solutions.

Scalable Parallel-In-Time Integration For Equations Of Motion, Nathan W. Chapman

All Master's Theses

Physical simulations always need to balance accuracy and run-time. This work implements the Parareal Algorithm using graphics processing units across a distributed system to accurately simulate time-dependent physics while attempting to minimize runtime. Data-transfer latency is identified as the primary bottleneck, for which mitigation methods are provided. Benchmarks comparing single-GPU and distributed implementations on a spectrum of coarse and fine discretizations are analyzed.