Physics Commons^™

Differential Elliptic Flow Analysis Of Hadrons With Different Wuark Content In Simulated Pp Collisions, Elhussein Osama

Theses and Dissertations

According to current physics theories, it is assumed that in the first microsecond after the big bang, the universe was in a state of matter called Quark-Gluon Plasma (QGP), where the fundamental consistent of matters (quarks and leptons), were highly energetic, and floating around freely. Searching for such phase of matter; as the possible earliest signatures after the big bang, and among many other interesting experimental measurements, the jet quenching and elliptic flow are the most important ones, in the heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) experiments.

The azimuthal anisotropy …

Quantics Tensor Trains: The Study Of A Continuous Lattice Model And Beyond, Aleix Bou Comas

Dissertations, Theses, and Capstone Projects

This four-chapter dissertation studies the efficient discretization of continuous variable functions with tensor train representation. The first chapter describes all the methodology used to discretize functions and store them efficiently. In this section, the algorithm tensor renormalization group is explained for self-containment purposes. The second chapter centers around the XY model. Quantics tensor trains are used to describe the transfer matrix of the model and compute one and two-dimensional quantities. The one dimensional magnitudes are compared to analytical results with an agreement close to machine precision. As for two dimensions, the analytical results cannot be computed. However, the critical temperature …

Toward The Development Of An Ultra-Fast, Bright Photoelectron Emission Source Using Tip Enhancement, Pei-Hsiang Yen, Erik J. Sanchez

Student Research Symposium

With the advancement of technology, people are pursuing even higher-resolution analysis results from metrology tools. When results are provided with temporal information, one can add a new dimension to the results. This research involves the development of a new temporal electron source by utilizing tip enhancement, which necessitates the creation of a novel type of emitter that emits electrons on a femtosecond (fs) time scale. Due to the nature of the electron’s mass, under the influence of an electric field they move quickly. To achieve our goal is the design of a resonant nano antenna (or known as a nantenna) …

The Analysis Of Mechanical Exfoliation Of Graphene For Various Fabrication And Automation Techniques, Lance Yarbrough

Mechanical Engineering Undergraduate Honors Theses

Mechanical Exfoliation of Graphene is an often-overlooked portion of the fabrication of quantum devices, and to create more devices quickly, optimizing this process to generate better flakes is critical. In addition, it would be valuable to simulate test pulls quickly, to gain insight on flake quality of various materials and exfoliation conditions. Physical pulls of graphene at various temperatures, pull forces, and pull repetitions were analyzed and compared to the results of ANSYS simulations, solved for similar results. Using ANSYS’ ability to predict trends in exfoliations, flake thickness and coverage using stress and deflection analyses were investigated. Generally, both strongly …

Proof-Of-Concept For Converging Beam Small Animal Irradiator, Benjamin Insley

Dissertations & Theses (Open Access)

The Monte Carlo particle simulator TOPAS, the multiphysics solver COMSOL., and

several analytical radiation transport methods were employed to perform an in-depth proof-ofconcept

for a high dose rate, high precision converging beam small animal irradiation platform.

In the first aim of this work, a novel carbon nanotube-based compact X-ray tube optimized for

high output and high directionality was designed and characterized. In the second aim, an

optimization algorithm was developed to customize a collimator geometry for this unique Xray

source to simultaneously maximize the irradiator’s intensity and precision. Then, a full

converging beam irradiator apparatus was fit with a multitude …

Quantum Computing Based Image Segmentation For Treatment Planning Applications, Rachel Glenn

Dissertations & Theses (Open Access)

The exponential advancement of quantum computing has led to its increasing integration into medical radiology. Quantum-inspired algorithms have helped accelerate magnetic resonance fingerprinting for possible applications in clinic settings. Numerous global initiatives are currently integrating quantum computing into medical radiology and health care applications. Given the potential of quantum computing to enhance clinical care and medical research, we have developed this primer to introduce medical physicists to the realm of quantum computing. In this primer, we explore the application of currently available quantum computing-based auto-contouring methods to image segmentation. These implementations serve as prototypes of existing quantum algorithms tailored for …

Evaluation Of An End-To-End Radiotherapy Treatment Planning Pipeline For Prostate Cancer, Mohammad Daniel El Basha, Court Laurence, Carlos Eduardo Cardenas, Julianne Pollard-Larkin, Steven Frank, David T. Fuentes, Falk Poenisch, Zhiqian H. Yu

Dissertations & Theses (Open Access)

Radiation treatment planning is a crucial and time-intensive process in radiation therapy. This planning involves carefully designing a treatment regimen tailored to a patient’s specific condition, including the type, location, and size of the tumor with reference to surrounding healthy tissues. For prostate cancer, this tumor may be either local, locally advanced with extracapsular involvement, or extend into the pelvic lymph node chain. Automating essential parts of this process would allow for the rapid development of effective treatment plans and better plan optimization to enhance tumor control for better outcomes.

The first objective of this work, to automate the treatment …

Divergence-Free Tensor Densities In Two Dimensions, Tyler Hansen

All Graduate Theses and Dissertations, Fall 2023 to Present

In physics, a common method for exploring the way a physical system changes over time is to look at the system’s energy. Roughly speaking, the energy in these systems are either motion-based (kinetic energy, a bullet in flight) or position-based (potential energy, a rock sitting at the top of a hill). The difference between the system’s total kinetic and potential energies is quantified by an expression called the Lagrangian. Using a special procedure, this Lagrangian is massaged to produce a group of equations called the Euler-Lagrange equations; if the initial configuration of the system is provided, the solution to these …

Adapt Laser Shaping, Quinlin Reynolds

ATU Research Symposium

Investigation into producing a machine learning algorithm that allows a He-Ne laser to classify whether a produced beam shape is uniformly gaussian or not, in order to adaptively move the laser to consistently target the encoded interference pattern area. This will then result in continuous uniform beam shapes of the desired output.

Uncharted: Measuring Beyond The Inner Galaxy, Carly J. Fitzgerald, Sammy Schneider, Landyn Schroeder

Research & Creative Achievement Day

My goal in conducting my research was to measure the speed of matter in the Milky Way galaxy using CHART -- the Completely Hackable Amateur Radio Telescope is an inexpensive, constructable telescope used to detect radio frequency waves in the galaxy. Using these waves and the doppler shift equation, I was able to measure the velocity of hydrogen gas in the inner galaxy. In doing this successfully, I was able to graph the relationship between the velocity and radius which is the rotational curve of the inner galaxy. I then collected and used additional data to calculate the rotational curve …

Anomalies Within Winona Campus On Protected Wavelengths, Landyn L. Schroeder, Carly Fitzgerald, Sammy Schneider

Research & Creative Achievement Day

The present study is being conducted with the intention of identifying where, why, and what is transmitting a radio signal of 1419 mmHg. This anomaly is intriguing because 1400-1427 mmHg waves are protected. Because this is a protected wave, it was interesting that it was being transmitted on Winona State Campus which is where the team began research. To gain information, the research team cast the horn to the sky at an elevation of 37 degrees and in the directions of 344 , 213, 143, and 60 degrees bearing, respectively. Now that this baseline information has been collected, the team …

Luminescence And Structural Properties Of Silicon-Germanium Quantum Structures Fabricated By Ion Implantation, Matheus Coelho Adam

Electronic Thesis and Dissertation Repository

The advancement of semiconductor materials has played a crucial role in driving positive technological breakthroughs that impact humanity in numerous ways. The presence of defects significantly alters the physical properties of semiconductors, making their analysis essential in the fabrication of semiconductor devices. I presented a new method to quantify surface and near-surface defects in single crystal semiconductors. Epitaxially-grown silicon was measured by low energy electron diffraction (LEED) to obtain the surface Debye temperature (θ_D). The results showed the surface θ_D of bulk Si (001), 1.0 μm, and 0.6 μm Si on sapphire of 333 K, 299 K, …

All-Optical Probes Of Particle-Like Charge Migration Dynamics, Kyle A. Hamer

LSU Doctoral Dissertations

Particle-like charge migration (CM) is the coherent, back-and-forth motion of a positively-charged electron hole along the backbone of a molecule following a sudden ionization. CM in small molecules generally occurs on an Angstrom (10^-10 m) spatial scale and an attosecond (10^-18 s) timescale. I use time-dependent density-functional theory (TDDFT) to simulate CM modes in organic molecules, and to explore all-optical probes of this attosecond electron dynamics using high-harmonic spectroscopy (HHS). By leveraging my results from previous studies of two-center interferences in carbon dichalcogens, in which I separated the harmonic signal into contributions from individual Kohn-Sham orbitals, I first …

Post-Modeling Adjustments And Delivered Dose Verification Of The 6fff Beam Model Commissioned For The Monaco Treatment Planning System, Grant C. Debevec

LSU Master's Theses

External beam radiation therapy has been shown to be an effective treatment method for tumors and abnormalities of the spine and vertebral region. Treating the spine using a stereotactic body radiation therapy (SBRT) technique can reduce toxicity to the spinal cord. The 6 MV flattening filter free (6FFF) beam model is currently used to plan and calculate dose for SBRT treatment plans, and the treatment plans are delivered using a linear accelerator (LINAC).

The commissioned beam model represents an invariant component of a LINAC. For volumetric modulated arc therapy (VMAT) treatment plans, the multileaf collimator (MLC) positions are changing throughout …

Dispersion Of Artificial Tracers In Ventilated Caves, Claudio Pastore, Eric Weber, Frédéric Doumenc, Pierre-Yves Jeannin, Marc Lütscher

International Journal of Speleology

Artificial CO₂ was used as a tracer along ventilated karst conduits to infer airflow and investigate tracer dispersion. In the karst vadose zone, cave ventilation is an efficient mode of transport for heat, gases and aerosols and thus drives the spatial distribution of airborne particles. Modelling this airborne transport requires geometrical and physical parameters of the conduit system, including the cross-sectional areas, the airflow and average air speed, as well as the longitudinal dispersion coefficient which describes the spreading of a solute. Four gauging tests were carried out in one mine (artificial conduit) and two ventilated caves (natural conduits). …

Non-Destructive Thickness Uniformity Measurement Of Photosensitive Gelatin Film, Clayton Halper

Physics Capstone Projects

Volume phase holographic gratings (VPHG’s) depend on dichromate gelatin of which uniform thickness is vital. The photosensitive nature of the film makes current thin film measurement devices not viable for production means. This project attempts to create a non-destructive measurement of photosensitive gelatin film used in VPHG production. Application of thin film interference at chosen wavelengths enable analysis of uniformity by comparison between the thin film inference patterns at different wavelengths. An initial proof of concept was established and a path towards a production ready device is outlined.

Effects Of Heterogeneous Data Sets And Time-Lag Measurement Techniques On Cosmological Parameter Constraints From Mg Ii And C Iv Reverberation-Mapped Quasar Data, Shulei Cao, Michal Zajaček, Bożena Czerny, Swayamtrupta Panda, Bharat Ratra

Physics Faculty Publications and Presentations

Previously, we demonstrated that Mg II and C IV reverberation-mapped quasars (RM QSOs) are standardizable and that the cosmological parameters inferred using the broad-line region radius–luminosity (R–L) relation are consistent with those determined from better-established cosmological probes. With more data expected from ongoing and future spectroscopic and photometric surveys, it is imperative to examine how new QSO data sets of varied quality, with their own specific luminosity and time-delay distributions, can be best used to determine more restrictive cosmological parameter constraints. In this study, we test the effect of adding 25 OzDES Mg II RM QSOs as well …

Fluorescence Microscopy With Deep Uv, Near Uv, And Visible Excitation For In Situ Detection Of Microorganisms, Noel Case, Nikki Johnston, Jay Nadeau

Physics Faculty Publications and Presentations

We report a simple, inexpensive design of a fluorescence microscope with light-emitting diode (LED) excitation for detection of labeled and unlabeled microorganisms in mineral substrates. The use of deep UV (DUV) excitation with visible emission requires no specialized optics or slides and can be implemented easily and inexpensively using an oblique illumination geometry. DUV excitation (<280 >nm) is preferable to near UV (365 nm) for avoidance of mineral autofluorescence. When excited with DUV, unpigmented bacteria show two emission peaks: one in the near UV ∼320 nm, corresponding to proteins, and another peak in the blue to green range, corresponding to …

Modeling And Numerical Analysis Of The Cholesteric Landau-De Gennes Model, Andrew L. Hicks

LSU Doctoral Dissertations

This thesis gives an analysis of modeling and numerical issues in the Landau-de Gennes (LdG) model of nematic liquid crystals (LCs) with cholesteric effects. We derive various time-step restrictions for a (weighted) $L^2$ gradient flow scheme to be energy decreasing. Furthermore, we prove a mesh size restriction, for finite element discretizations, that is critical to avoid spurious numerical artifacts in discrete minimizers that is not well-known in the LC literature, particularly when simulating cholesteric LCs that exhibit ``twist''. Furthermore, we perform a computational exploration of the model and present several numerical simulations in 3-D, on both slab geometries and spherical …

Analyzing The Influence Of Design And Operating Conditions On Combustion And Emissions In Premixed Turbulent Flames: A Comprehensive Review, Medhat Elkelawy Prof. Dr. Eng., E. A. El Shenawy Prof. Dr., Hagar Alm-Eldin Bastawissi, Ibrahim Ali Mousa Eng., Mohamed M. Abdel-Raouf Ibrahim Dr. Eng.

Journal of Engineering Research

Recently, premixed combustion has dominated the field of combustion research worldwide. The current work is a review that addresses the effects of design and operating regimes on the combustion and emission characteristics of premixed turbulent flames. The study accounts for recent developments aimed at overcoming combustor operability issues that influence emissions and flame stability. Various experimental setups have been utilized in investigations, with results pertaining to performance and emissions concerning premixed turbulent flames. Thus, the objective of this paper is to provide a comprehensive review of the effects of swirl vane angles and equivalence fuel-air ratios for tests conducted both …