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Full-Text Articles in Physical Sciences and Mathematics

Differential Elliptic Flow Analysis Of Hadrons With Different Wuark Content In Simulated Pp Collisions, Elhussein Osama Jun 2024

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 Jun 2024

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 May 2024

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 May 2024

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 May 2024

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 …


Divergence-Free Tensor Densities In Two Dimensions, Tyler Hansen May 2024

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 Apr 2024

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 Apr 2024

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 Apr 2024

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 Apr 2024

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 (θD). The results showed the surface θD 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 Apr 2024

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 Apr 2024

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 Apr 2024

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 Apr 2024

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 Apr 2024

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 Apr 2024

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 Apr 2024

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. Mar 2024

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 …


Advancements In Characterization Of Ancient Potteries From Southeast Asia: A Review Of Analytical Techniques, Chitnarong Sirisathitkul Mar 2024

Advancements In Characterization Of Ancient Potteries From Southeast Asia: A Review Of Analytical Techniques, Chitnarong Sirisathitkul

Makara Journal of Science

Ancient potteries offer valuable information regarding technological advancements, life dynamics, cultural diversity, and trade routes in the past. Earthenware, stoneware, and porcelain from Southeast Asia have been characterized using several analytical techniques, as reviewed in this article. Fluorescent and diffracted X-rays give rise to elemental and phase compositions, respectively. Examination of molecular bonds requires vibrational spectroscopy, which is useful for the identification of organic materials in ancient potteries. With the advent of portable X-ray fluorescence and Raman spectrometry, on-site analysis of archeological ceramics is now possible. For in-depth analysis, synchrotron light sources can provide new insights into artifacts through X-ray …


Synthesis, Structural And Thermal Studies Of Dl-Alanine Potassium Di- Chromate Single Crystals, Sundararaj Lincy Mary Ponmani, Soundararajan Gnanakkan Pushpalatha Gracelin, Somasundaram Selvakumar, Subbaiah Chelladurai Vella Durai Mar 2024

Synthesis, Structural And Thermal Studies Of Dl-Alanine Potassium Di- Chromate Single Crystals, Sundararaj Lincy Mary Ponmani, Soundararajan Gnanakkan Pushpalatha Gracelin, Somasundaram Selvakumar, Subbaiah Chelladurai Vella Durai

Makara Journal of Science

Amino acids and their complexes are organic or semiorganic materials that have attracted considerable attention because they can be easily used in optical storage devices. DL-alanine is one of the rare amino acids that crystallizes in anoncentrosymmetric group. This article demonstrates how DL-alanine potassium dichromate (DAPC) single crystals have shown sufficient growth. DAPC crystals were analyzed by single crystal X-ray diffraction and powder X-ray diffraction. Using thermogravimetric analysis/differential thermal analysis (TGA/DTA) and differential scanning calorimetry, this work also examined the melting point, thermal stability, decomposition point, and other thermal parameters of the DAPC crystals. Results show that the decomposition point …


Effect Of Fabrication Parameters On The Ferroelectricity Of Hafnium Zirconium Oxide Films: A Statistical Study, Guillermo A. Salcedo, Ahmad E. Islam, Elizabeth Reichley, Michael Dietz, Christine M. Schubert Kabban, Kevin D. Leedy, Tyson C. Back, Weison Wang, Andrew Green, Timothy S. Wolfe, James M. Sattler Mar 2024

Effect Of Fabrication Parameters On The Ferroelectricity Of Hafnium Zirconium Oxide Films: A Statistical Study, Guillermo A. Salcedo, Ahmad E. Islam, Elizabeth Reichley, Michael Dietz, Christine M. Schubert Kabban, Kevin D. Leedy, Tyson C. Back, Weison Wang, Andrew Green, Timothy S. Wolfe, James M. Sattler

Faculty Publications

Ferroelectricity in hafnium zirconium oxide (Hf1−xZrxO2) and the factors that impact it have been a popular research topic since its discovery in 2011. Although the general trends are known, the interactions between fabrication parameters and their effect on the ferroelectricity of Hf1−xZrxO2 require further investigation. In this paper, we present a statistical study and a model that relates Zr concentration (x), film thickness (tf), and annealing temperature (Ta) with the remanent polarization (Pr) in tungsten (W)-capped Hf1−xZrxO2. …


Investigation Of Gas Dynamics In Water And Oil-Based Muds Using Das, Dts, And Dss Measurements, Temitayo S. Adeyemi Mar 2024

Investigation Of Gas Dynamics In Water And Oil-Based Muds Using Das, Dts, And Dss Measurements, Temitayo S. Adeyemi

LSU Master's Theses

Reliable prediction of gas migration velocity, void fraction, and length of gas-affected region in water and oil-based muds is essential for effective planning, control, and optimization of drilling operations. However, there is a gap in our understanding of gas behavior and dynamics in water and oil-based muds. This is a consequence of the use of experimental systems that are not representative of field-scale conditions. This study seeks to bridge the gap via the well-scale deployment of distributed fiber-optic sensors for real-time monitoring of gas behavior and dynamics in water and oil-based mud. The aforementioned parameters were estimated in real-time using …


Quantum Chaos, Integrability, And Hydrodynamics In Nonequilibrium Quantum Matter, Javier Lopez Piqueres Mar 2024

Quantum Chaos, Integrability, And Hydrodynamics In Nonequilibrium Quantum Matter, Javier Lopez Piqueres

Doctoral Dissertations

It is well-known that the Hilbert space of a quantum many-body system grows exponentially with the number of particles in the system. Drive the system out of equilibrium so that the degrees of freedom are now dynamic and the result is an extremely complicated problem. With that comes a vast landscape of new physics, which we are just recently starting to explore. In this proposal, we study the dynam- ics of two paradigmatic classes of quantum many-body systems: quantum chaotic and integrable systems. We leverage certain tools commonly employed in equilibrium many-body physics, as well as others tailored to the …


Toward Local Madelung Mechanics In Spacetime, Mordecai Waegell Mar 2024

Toward Local Madelung Mechanics In Spacetime, Mordecai Waegell

Mathematics, Physics, and Computer Science Faculty Articles and Research

It has recently been shown that relativistic quantum theory leads to a local interpretation of quantum mechanics wherein the universal wavefunction in configuration space is entirely replaced with an ensemble of local fluid equations in spacetime. For want of a fully relativistic quantum fluid treatment, we develop a model using the nonrelativistic Madelung equations, and obtain conditions for them to be local in spacetime. Every particle in the Madelung fluid is equally real, and has a definite position, momentum, kinetic energy, and potential energy. These are obtained by defining quantum momentum and kinetic energy densities for the fluid and separating …


X-Currents And Extreme Brightening Events, Abrielle Tio An Mei Wang, Gerard J. Fasel, Audrey Daucher, Makena Swenski, Andrea Black, John Mann, Maame Osei-Tutu Mar 2024

X-Currents And Extreme Brightening Events, Abrielle Tio An Mei Wang, Gerard J. Fasel, Audrey Daucher, Makena Swenski, Andrea Black, John Mann, Maame Osei-Tutu

Seaver College Research And Scholarly Achievement Symposium

The solar-terrestrial interaction is a dynamic process which manifests itself in the ionosphere. Interplanetary (IP) shocks or solar wind dynamic pressure pulses can generate enhanced brightening in dayside aurora. Foreshock transients are capable of inducing pressure changes, larger in magnitude than solar wind pressure pulses, which also contribute to intensifying dayside aurora. These pressure variations can accelerate particles into the ionosphere, generating field- aligned currents that produce magnetic impulse events and enhanced dayside auroral activity with periods of increased brightening. This study presents several dayside auroral brightening events which are not associated with IP shocks or solar wind dynamic pressure …


Coomassie Brilliant Blue Dye As A Method For Analyzing Fracture Markings In Bone, Abigail Hoffmeister, David Harutunyan, Matthew Aizawa, Everett Baker, Brandon Mendoza, Chase Freeman, Siran Iskanian Mar 2024

Coomassie Brilliant Blue Dye As A Method For Analyzing Fracture Markings In Bone, Abigail Hoffmeister, David Harutunyan, Matthew Aizawa, Everett Baker, Brandon Mendoza, Chase Freeman, Siran Iskanian

Seaver College Research And Scholarly Achievement Symposium

Coomassie Brilliant Blue Dye is a dye commonly used to stain proteins. Because of its ability to adhere to proteins, this research has focused on perfecting a method of dyeing a fractured flat bone in order to most accurately observe and analyze fracture markings within the trabecular layer. Stereoscopic microscopy was the chosen technique of analysis for this research because of its proven effectiveness in glass and ceramic fractography to observe varying depths. In order to most effectively apply stereoscopic microscopy to this research, the following variables were manipulated to maximize color contrast in the trabecular layer in order to …


Machine Learning Prediction Of Photoluminescence In Mos2: Challenges In Data Acquisition And A Solution Via Improved Crystal Synthesis, Ethan Swonger, John Mann, Jared Horstmann, Daniel Yang Mar 2024

Machine Learning Prediction Of Photoluminescence In Mos2: Challenges In Data Acquisition And A Solution Via Improved Crystal Synthesis, Ethan Swonger, John Mann, Jared Horstmann, Daniel Yang

Seaver College Research And Scholarly Achievement Symposium

Transition metal dichalcogenides (TMDCs) like molybdenum disulfide (MoS2) possess unique electronic and optical properties, making them promising materials for nanotechnology. Photoluminescence (PL) is a key indicator of MoS2 crystal quality. This study aimed to develop a machine-learning model capable of predicting the peak PL wavelength of single MoS2 crystals based on micrograph analysis. Our limited ability to consistently synthesize high-quality MoS2 crystals hampered our ability to create a large set of training data. The project focus shifted towards improving MoS2 crystal synthesis to generate improved training data. We implemented a novel approach utilizing low-pressure chemical vapor deposition (LPCVD) combined with …


Mechanistic Investigation Of C—C Bond Activation Of Phosphaalkynes With Pt(0) Complexes, Roberto M. Escobar, Abdurrahman C. Ateşin, Christian Müller, William D. Jones, Tülay Ateşin Mar 2024

Mechanistic Investigation Of C—C Bond Activation Of Phosphaalkynes With Pt(0) Complexes, Roberto M. Escobar, Abdurrahman C. Ateşin, Christian Müller, William D. Jones, Tülay Ateşin

Research Symposium

Carbon–carbon (C–C) bond activation has gained increased attention as a direct method for the synthesis of pharmaceuticals. Due to the thermodynamic stability and kinetic inaccessibility of the C–C bonds, however, activation of C–C bonds by homogeneous transition-metal catalysts under mild homogeneous conditions is still a challenge. Most of the systems in which the activation occurs either have aromatization or relief of ring strain as the primary driving force. The activation of unstrained C–C bonds of phosphaalkynes does not have this advantage. This study employs Density Functional Theory (DFT) calculations to elucidate Pt(0)-mediated C–CP bond activation mechanisms in phosphaalkynes. Investigating the …


Spectroscopic End Point Detection With An Electron Beam Evaporator, Ryan Mcgraw Mar 2024

Spectroscopic End Point Detection With An Electron Beam Evaporator, Ryan Mcgraw

University Honors Theses

Spectroscopic end point detection is a common tool used for measuring slope changes in wavelength intensity. Using algorithms able to apply this concept, coatings will be able to be dynamically measured in real time and stopped at the appropriate level to ensure process uniformity. It is currently applied to reductive processes such as etching, where the surface will start to be eaten away, creating a plasma. When the entire amount of a material on a substrate has been eaten away, the plasma will change color as it is beginning to etch a different material. Using a spectrometer, this point where …


Second Inflection Point Of Supercooled Water Surface Tension Induced By Hydrogen Bonds: A Molecular-Dynamics Study, Fawaz Hrahsheh, Inshad Jum'h, Gerald Wilemski Mar 2024

Second Inflection Point Of Supercooled Water Surface Tension Induced By Hydrogen Bonds: A Molecular-Dynamics Study, Fawaz Hrahsheh, Inshad Jum'h, Gerald Wilemski

Physics Faculty Research & Creative Works

Surface Tension Of Supercooled Water Is A Fundamental Property In Various Scientific Processes. In This Study, We Perform Molecular Dynamics Simulations With The TIP4P-2005 Model To Investigate The Surface Tension Of Supercooled Water Down To 220 K. Our Results Show A Second Inflection Point (SIP) In The Surface Tension At Temperature TSIP ≈ 267.5 ± 2.3 K. Using An Extended IAPWS-E Functional Fit For The Water Surface Tension, We Calculate The Surface Excess Internal-Energy And Entropy Terms Of The Excess Helmholtz Free Energy. Similar To Prior Studies [Wang Et Al., Phys. Chem. Chem. Phys. 21, 3360 (2019); Gorfer Et Al., …