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2022

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Articles 31 - 60 of 1410

Full-Text Articles in Physics

Does Science Need Intersubjectivity? The Problem Of Confirmation In Orthodox Interpretations Of Quantum Mechanics, Emily Adlam Dec 2022

Does Science Need Intersubjectivity? The Problem Of Confirmation In Orthodox Interpretations Of Quantum Mechanics, Emily Adlam

Mathematics, Physics, and Computer Science Faculty Articles and Research

Any successful interpretation of quantum mechanics must explain how our empirical evidence allows us to come to know about quantum mechanics. In this article, we argue that this vital criterion is not met by the class of ‘orthodox interpretations,’ which includes QBism, neo-Copenhagen interpretations, and some versions of relational quantum mechanics. We demonstrate that intersubjectivity fails in radical ways in these approaches, and we explain why intersubjectivity matters for empirical confirmation. We take a detailed look at the way in which belief-updating might work in the kind of universe postulated by an orthodox interpretation, and argue that observers in such …


Powerful Yet Lonely: Is 3c 297 A High-Redshift Fossil Group?, Valentina Missaglia, Juan P. Madrid, Mischa Schirmer, Francesco Massaro, Alberto Rodríguez-Ardila, Carlos J. Donzelli, Martell Valencia, Alessandro Paggi, Ralph P. Kraft, Chiara Stuardi, Belinda J. Wilkes Dec 2022

Powerful Yet Lonely: Is 3c 297 A High-Redshift Fossil Group?, Valentina Missaglia, Juan P. Madrid, Mischa Schirmer, Francesco Massaro, Alberto Rodríguez-Ardila, Carlos J. Donzelli, Martell Valencia, Alessandro Paggi, Ralph P. Kraft, Chiara Stuardi, Belinda J. Wilkes

Physics & Astronomy Faculty Publications

The environment of the high-redshift (z = 1.408), powerful radio-loud galaxy 3C 297 has several distinctive features of a galaxy cluster. Among them, a characteristic halo of hot gas revealed by Chandra X-ray observations. In addition, a radio map obtained with the Very Large Array shows a bright hotspot in the northwestern direction, created by the interaction of the active galactic nucleus (AGN) jet arising from 3C 297 with its environment. In the X-ray images, emission cospatial with the northwestern radio lobe is detected, and peaks at the position of the radio hotspot. The extended, complex X-ray emission observed …


Proposal For A Definitive Search For Gut-Scale Qcd Axions, L. Brouwer, S. Chaudhuri, H. M. Cho, J. Corbin, C. S. Dawson, A. Droster, J. W. Foster, J. T. Fry, P. W. Graham, R. Henning, K. D. Irwin, F. Kadribasic, Y. Kahn, A. Keller, R. Kolevatov, S. Kuenstner, A. F. Leder, D. Li, J. L. Ouellet, K. M. W. Pappas, A. Phipps, N. M. Rapidis, B. R. Safdi, C. P. Salemi, M. Simanovskaia, J. Singh, E. C. Van Assendelft, K. Van Bibber, K. Wells, L. Winslow, W. J. Wisniewski, Betty A. Young Dec 2022

Proposal For A Definitive Search For Gut-Scale Qcd Axions, L. Brouwer, S. Chaudhuri, H. M. Cho, J. Corbin, C. S. Dawson, A. Droster, J. W. Foster, J. T. Fry, P. W. Graham, R. Henning, K. D. Irwin, F. Kadribasic, Y. Kahn, A. Keller, R. Kolevatov, S. Kuenstner, A. F. Leder, D. Li, J. L. Ouellet, K. M. W. Pappas, A. Phipps, N. M. Rapidis, B. R. Safdi, C. P. Salemi, M. Simanovskaia, J. Singh, E. C. Van Assendelft, K. Van Bibber, K. Wells, L. Winslow, W. J. Wisniewski, Betty A. Young

Physics

The QCD axion is a leading dark matter candidate that emerges as part of the solution to the strong 𝐶⁢𝑃 problem in the Standard Model. The coupling of the axion to photons is the most common experimental probe, but much parameter space remains unexplored. The coupling of the QCD axion to the Standard Model scales linearly with the axion mass; therefore, the highly motivated region 0.4–120 neV, corresponding to a GUT-scale axion, is particularly difficult to reach. This paper presents the design requirements for a definitive search for GUT-scale axions and reviews the technological advances needed to enable this program.


Black Holes, Disk Structures, And Cosmological Implications In E-Dimensional Space, Subhash Kak, Menas C. Kafatos Dec 2022

Black Holes, Disk Structures, And Cosmological Implications In E-Dimensional Space, Subhash Kak, Menas C. Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

We examine a modern view of the universe that builds on achieved successes of quantum mechanics, general relativity, and information theory, bringing them together in integrated approach that is founded on the realization that space itself is e-dimensional. The global and local implications of noninteger dimensionality are examined, and how it may have increased from the value of zero to its current value is investigated. We find surprising aspects that tie to structures in the universe, black holes, and the role of observations.


Extracellular Vimentin Is Sufficient To Promote Cell Attachment, Spreading, And Motility By A Mechanism Involving N-Acetyl Glucosamine-Containing Structures, Robert Bucki, Daniel V. Iwamoto, Xuechen Shi, Katherine E. Kerr, Fitzroy J. Byfield, Lukasz Suprewicz, Karol Sklodowski, Julian Sutaria, Pawel Misiak, Agnieszka Z. Wilczewska, Sekar Ramachandran, Aaron Wolfe, Minh H. Thanh, Eli Whalen, Alison E. Patteson, Paul A. Janmey Dec 2022

Extracellular Vimentin Is Sufficient To Promote Cell Attachment, Spreading, And Motility By A Mechanism Involving N-Acetyl Glucosamine-Containing Structures, Robert Bucki, Daniel V. Iwamoto, Xuechen Shi, Katherine E. Kerr, Fitzroy J. Byfield, Lukasz Suprewicz, Karol Sklodowski, Julian Sutaria, Pawel Misiak, Agnieszka Z. Wilczewska, Sekar Ramachandran, Aaron Wolfe, Minh H. Thanh, Eli Whalen, Alison E. Patteson, Paul A. Janmey

Physics - All Scholarship

Vimentin intermediate !laments form part of the cytoskeleton

of mesenchymal cells, but under pathological conditions often

associatedwith in"ammation, vimentin !laments depolymerize as

the result of phosphorylation or citrullination, and vimentin

oligomers are secreted or released into the extracellular environment.

In the extracellular space, vimentin can bind surfaces of cells

and the extracellular matrix, and the interaction between extracellular

vimentin and cells can trigger changes in cellular functions,

such as activation of !broblasts to a !brotic phenotype. The

mechanism by which extracellular vimentin binds external cell

membranes and whether vimentin alone can act as an adhesive

anchor for cells is largely …


What Is Nonclassical About Uncertainty Relations?, Lorenzo Catani, Matthew S. Leifer, Giovanni Scala, David Schmid, Robert W. Spekkens Dec 2022

What Is Nonclassical About Uncertainty Relations?, Lorenzo Catani, Matthew S. Leifer, Giovanni Scala, David Schmid, Robert W. Spekkens

Mathematics, Physics, and Computer Science Faculty Articles and Research

Uncertainty relations express limits on the extent to which the outcomes of distinct measurements on a single state can be made jointly predictable. The existence of nontrivial uncertainty relations in quantum theory is generally considered to be a way in which it entails a departure from the classical worldview. However, this perspective is undermined by the fact that there exist operational theories which exhibit nontrivial uncertainty relations but which are consistent with the classical worldview insofar as they admit of a generalized-noncontextual ontological model. This prompts the question of what aspects of uncertainty relations, if any, cannot be realized in …


Precise Measurement Of The Nuclear Dependence Of The Emc Effect In Light Nuclei, Abishek Karki, Abishek Karki Dec 2022

Precise Measurement Of The Nuclear Dependence Of The Emc Effect In Light Nuclei, Abishek Karki, Abishek Karki

Theses and Dissertations

Measurements of inclusive electron scattering cross-section ratios from light nuclei over a wide range of the Björken �� (0.3 < �� < 1) up to �� 2 = 8.3 GeV2 were made as part of experiment E10-10-008, which was conducted in Hall C at the Thomas Jefferson National Accelerator Facility. The measurements were performed using a beam energy of 10.602 GeV and an average beam current of 45 ��A. This dissertation provides a thorough description of the experiment as well as the extracted ratios of inclusive nuclear cross-sections with respect to the deuterium cross-sections (the EMC effect) for the targets 9 Be, 12 C, 10 B, and 11 B. The …


Molecular Insights Into The Redox Of Atmospheric Mercury Through Laser Spectroscopy, Rongrong Wu Cohen Dec 2022

Molecular Insights Into The Redox Of Atmospheric Mercury Through Laser Spectroscopy, Rongrong Wu Cohen

Theses and Dissertations

The widespread pollution of mercury motivates research into its atmospheric chemistry and transport. Gaseous elemental mercury (Hg(0)) dominates mercury emission to the atmosphere, but the rate of its oxidation to mercury compound (Hg(II)) plays a significant role in controlling where and when mercury deposits to ecosystems. Atomic bromine is regarded as the main oxidant for Hg(0) oxidation, known to initiate the oxidation via a two-step process in the atmosphere – formation of BrHg (R1) and subsequent reactions of BrHg with abundant free radicals Y, i.e., NO2, HOO, etc. (R2), where the reaction of BrHg +Y could also lead to the …


Nuclear Power Plant In Las Vegas, Ryan W. Murray Dec 2022

Nuclear Power Plant In Las Vegas, Ryan W. Murray

Undergraduate Research Symposium Posters

This research focuses on the impact of a “Nuclear Power Plant in Las Vegas” or ‘NPP in LV’ for short. Nuclear power is clean, has no greenhouse gas emissions, and has a moderate cost of kilowatt hours. Las Vegas, or more specifically Clark County uses Gas power plants to produce a majority of their electricity. My project will show what a nuclear plant could do if built in the city of Las Vegas. What is a Nuclear power plant? The EIA’s definition is “A nuclear power plant uses the heat that a nuclear reactor produces to turn water into steam, …


Trapping And Cooling Of Ca+ For Cold Ion-Radical Collisions, Bernardo Gutierrez Dec 2022

Trapping And Cooling Of Ca+ For Cold Ion-Radical Collisions, Bernardo Gutierrez

Undergraduate Research Symposium Posters

Free radicals are molecules that contain an unpaired valence electron which induces high reactivity. Ion radical reactions are typically exothermic and have low (or zero) activation energy. It is for these reasons that ion-radical reactions are believed to dominate in interstellar clouds where temperatures hover around 3-10K. State-to-state measurements require precision control of both reactants.


Evaluation Of Yttrium Stabilized Zirconium Thin Films With Secondary Ion Mass Spectrometry, Jeff Serfass Dec 2022

Evaluation Of Yttrium Stabilized Zirconium Thin Films With Secondary Ion Mass Spectrometry, Jeff Serfass

Seton Hall University Dissertations and Theses (ETDs)

Fuel Cells using solid oxides for the electrolyte material, or Solid Oxide Fuel Cells (SOFCs), can operate at high temperatures and have many benefits when compared to other electrolyte material-based fuel cells. SOFCs can, however still have problems when operating at these high temperatures. (~1,000 degrees Celsius) At high temperatures, the SOFC electrolyte resistivity goes up making the ionic conductivity decrease and therefore a loss of performance. The inclusion of low level Yttria to Zirconium Oxide (the electrolyte material) has been known to help reduce the resistivity at high operating temperatures. In this study, a series of Yttria stabilized Zirconium …


Ultrafast Electron Diffraction: Visualizing Dynamic States Of Matter, D. Filippetto, P. Musumeci, R. K. Li, B. J. Siwick, M. R. Otto, Martin Centurion, J. P. F. Nunes Dec 2022

Ultrafast Electron Diffraction: Visualizing Dynamic States Of Matter, D. Filippetto, P. Musumeci, R. K. Li, B. J. Siwick, M. R. Otto, Martin Centurion, J. P. F. Nunes

Department of Physics and Astronomy: Faculty Publications

Since the discovery of electron-wave duality, electron scattering instrumentation has developed into a powerful array of techniques for revealing the atomic structure of matter. Beyond detecting local lattice variations in equilibrium structures with the highest possible spatial resolution, recent research efforts have been directed toward the long-sought-after dream of visualizing the dynamic evolution of matter in real time. The atomic behavior at ultrafast timescales carries critical information on phase transition and chemical reaction dynamics, the coupling of electronic and nuclear degrees of freedom in materials and molecules, and the correlation among structure, function, and previously hidden metastable or nonequilibrium states …


Possibilities For Inertial Electrostatic Confinement Fusion, Jeffrey Edward Black Dec 2022

Possibilities For Inertial Electrostatic Confinement Fusion, Jeffrey Edward Black

Dissertations and Theses

While most of the fusion energy research is focused on magnetic confinement, there have been several alternative confinement methods aimed at the development of smaller and less expensive reactors. A number of these devices utilize a spherically convergent beam of recirculating ions, a technique known as inertial electrostatic confinement (IEC). This study looks at several aspects of IEC devices, including measurements of the fusion rate of an IEC device with a wire mesh electrode cathode, and a solid titanium cathode. In addition, several computational studies were performed to explore the possibilities for IEC fusion. These include development of a 1D-1P …


Behaviors For Which Deinonychosaurs Used Their Feet, Alexander King Dec 2022

Behaviors For Which Deinonychosaurs Used Their Feet, Alexander King

Honors Projects

This paper seeks to show for what purpose deinonychosaurs used their feet. Fowler et al., (2011) showed that D. antirrhopus’s feet were closest in function to accipitrids, as they found it was more built for grasping prey than running.

I answered this question by using 2D images of the feet of three modern birds (Buteo jamaicensis, Phasianus colchicus, and Gallus gallus domesticus), one eudromaeosaur (Deinonychus antirrhopus), and one troodontid (Borogovia gracilicrus). I used ImageJ to apply 73 landmarks to each foot, capturing the variation between species in the metatarsals and pedal phalanges. These data were then uploaded to the software …


Six-Dimensional Single-Molecule Imaging With Isotropic Resolution Using A Multi-View Reflector Microscope, Oumeng Zhang, Zijian Guo, Yuanyuan He, Tingting Wu, Michael D. Vahey, Matthew D. Lew Dec 2022

Six-Dimensional Single-Molecule Imaging With Isotropic Resolution Using A Multi-View Reflector Microscope, Oumeng Zhang, Zijian Guo, Yuanyuan He, Tingting Wu, Michael D. Vahey, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

Imaging of both the positions and orientations of single fluorophores, termed single-molecule orientation-localization microscopy, is a powerful tool for the study of biochemical processes. However, the limited photon budget associated with single-molecule fluorescence makes high-dimensional imaging with isotropic, nanoscale spatial resolution a formidable challenge. Here we realize a radially and azimuthally polarized multi-view reflector (raMVR) microscope for the imaging of the three-dimensional (3D) positions and 3D orientations of single molecules, with precisions of 10.9 nm and 2.0° over a 1.5-μm depth range. The raMVR microscope achieves 6D super-resolution imaging of Nile red molecules transiently bound to lipid-coated spheres, accurately resolving …


Ds2 As Excitation Of Ads2, Florian Ecker, Daniel Grumiller, Robert Mcnees Dec 2022

Ds2 As Excitation Of Ads2, Florian Ecker, Daniel Grumiller, Robert Mcnees

Physics: Faculty Publications and Other Works

Title- dS2 as excitation of AdS2

We introduce a family of 2D dilaton gravity models with state-dependent constant curvature so that dS2 emerges as an excitation of AdS2. Curiously, the strong coupling region corresponds to the asymptotic region geometrically. Apart from these key differences, many features resemble the Almheiri–Polchinski model. We discuss perturbative and non-perturbative thermodynamical stability, bubble nucleation through matter shockwaves, and semiclassical backreaction effects. In some of these models, we find that low temperatures are dominated by AdS2 but high temperatures are dominated by dS2, concurrent with a recent proposal …


Stabilization Of Zero-Energy Skin Modes In Finite Non-Hermitian Lattices, Cem Yuce, Hamidreza Ramezani Dec 2022

Stabilization Of Zero-Energy Skin Modes In Finite Non-Hermitian Lattices, Cem Yuce, Hamidreza Ramezani

Physics & Astronomy Faculty Publications

The zero energy of a one-dimensional semi-infinite non-Hermitian lattice with nontrivial spectral topology may disappear when we introduce boundaries to the system. While the corresponding zero-energy state can be considered as a quasi-edge state for the finite lattice with a long survival time, any small disruption (noise) in the initial form of the quasi-edge state can significantly shorten the survival time. Here, by tailoring the couplings at one edge we form an exceptional point allowing for a topological phase transition and the stabilization of the quasi-edge state in a finite-size lattice with open edges. Such a small modification in the …


(R1978) Heated Laminar Vertical Jet Of Psudoplastic Fluids-Against Gravity, Manisha Patel, M. G. Timol Dec 2022

(R1978) Heated Laminar Vertical Jet Of Psudoplastic Fluids-Against Gravity, Manisha Patel, M. G. Timol

Applications and Applied Mathematics: An International Journal (AAM)

A heated laminar jet of Pseudo-plastic fluid flowing vertically upwards from a long narrow slit into a region of the same fluid which is at a rest and at a uniform temperature is considered. The governing non-linear Partial differential equations (PDEs) for the defined flow problem are transformed into non-linear ordinary differential equations using the effective similarity technique-one parameter deductive group theory method. The obtained non-linear coupled Ordinary differential equations are solved and the results are presented by graphs. The effect of the Prandtl number and Grashof number on the velocity and temperature of the jet flow is discussed. Also, …


Supercontinuum Light Generation Via Non-Linear Effects In Hollow-Core Fiber, Skyler Gulati Dec 2022

Supercontinuum Light Generation Via Non-Linear Effects In Hollow-Core Fiber, Skyler Gulati

Physics Student Works

The field of non-linear optics has gained traction in the last couple decades due to the variable generation of wavelengths which are less deterministic than within traditional optics. Using non-linear mediums, including hollow-core fibers (HCF), generation of wavelengths spanning into the vacuum ultraviolet (VUV) wavelength range is possible. These short wavelengths can be utilized within electron spectroscopy-based methods of material science like angle-resolved photoemission spectroscopy (ARPES). This technique most often uses specific photoemission lines of atoms in discharge lamps, however, with the frequency dispersion capabilities of HCF, broad band creation can allow for variable wavelength selection through filtering specific wavelengths …


Phase Transitions In Evolutionary Dynamics, Adam D. Scott, Dawn M. King, Stephen W. Ordway, Sonya Bahar Dec 2022

Phase Transitions In Evolutionary Dynamics, Adam D. Scott, Dawn M. King, Stephen W. Ordway, Sonya Bahar

Physics Faculty Works

Sharp changes in state, such as transitions from survival to extinction, are hallmarks of evolutionary dynamics in biological systems. These transitions can be explored using the techniques of statistical physics and the physics of nonlinear and complex systems. For example, a survival-to-extinction transition can be characterized as a non-equilibrium phase transition to an absorbing state. Here, we review the literature on phase transitions in evolutionary dynamics. We discuss directed percolation transitions in cellular automata and evolutionary models, and models that diverge from the directed percolation universality class. We explore in detail an example of an absorbing phase transition in an …


A Study Of The Structural, Optical, And Ferroelectric Characteristics Of Pb-Ge-Te Nanocrystalline Alloys As Potential Candidates For Memory Devices And Near-Infrared (Nir) Applications, Asmaa Elkhodary, Salah M. Elsheikh, Hosny A. Omar, Manal A. Mahdy, Iman A. Mahdy Dec 2022

A Study Of The Structural, Optical, And Ferroelectric Characteristics Of Pb-Ge-Te Nanocrystalline Alloys As Potential Candidates For Memory Devices And Near-Infrared (Nir) Applications, Asmaa Elkhodary, Salah M. Elsheikh, Hosny A. Omar, Manal A. Mahdy, Iman A. Mahdy

Basic Science Engineering

Pb50-xGexTe50 (x = 15, 20, 25, 30 at. %) nanocrystalline bulk alloys were prepared using solid-state direct reaction. X-ray diffraction and high-resolution transmission electron microscopy (HR-TEM) analysis of the reference structure (Ge = 15 at.%) revealed a slightly distorted cubic structure, with a lattice parameter of 6.43 Å and an inter-axis unit cell angle of 88.69◦. Atomic force images’ analysis and histograms displayed a homogenous particle size distribution in the nanoscale for all samples. Density measurements showed a gradual decrease from 7.89 to 6.98 g/cm3 with increasing Ge content in agreement with the calculated values. …


Spacecraft Charging Test Considerations For Composite Materials, Allen Andersen, Wousik Kim, J. R. Dennison, Brian Wood, Todd A. Schneider, Jason Vaughn, Kenneth H. Wright Jr., Nelson W. Green, Eric Suh, Joel Schwartz, Abdul-Majeed Azad Dec 2022

Spacecraft Charging Test Considerations For Composite Materials, Allen Andersen, Wousik Kim, J. R. Dennison, Brian Wood, Todd A. Schneider, Jason Vaughn, Kenneth H. Wright Jr., Nelson W. Green, Eric Suh, Joel Schwartz, Abdul-Majeed Azad

Journal Articles

Composite materials present a growing challenge for spacecraft charging assessments. We review some recent lessons learned for charging tests of composite materials using both parallel-plate and electron beam test geometries. We also discuss examples of materials that exhibit significant variations between samples, despite them all having the same trade name.


Braiding Properties Of Worldline Configurations In Hardcore Lattice Bosons, Fabio Lingua, Wei Wang, Liana Shpani, Barbara Capogrosso-Sansone Dec 2022

Braiding Properties Of Worldline Configurations In Hardcore Lattice Bosons, Fabio Lingua, Wei Wang, Liana Shpani, Barbara Capogrosso-Sansone

Physics

In this manuscript, we study braiding properties of worldline configurations for a variety of ground-states of hardcore Bose–Hubbard models in two dimensions. Configurations are collections of particle paths and result from the path-integral formulation of statistical mechanics. For hard-core bosons, configurations can be seen as geometric braids and therefore can be assigned a certain topological structure, i.e. a way to classify braiding events among worldlines. By means of Monte Carlo calculations, we study superfluid phase and a variety of insulating phases and observe that ground-states of different quantum phases correspond to different probability distributions of braiding properties.

An Author Correction …


Gate-Controlled Quantum Dots In Two-Dimensional Tungsten Diselenide And One-Dimensional Tellurium Nanowires, Shiva Davari Dolatabadi Dec 2022

Gate-Controlled Quantum Dots In Two-Dimensional Tungsten Diselenide And One-Dimensional Tellurium Nanowires, Shiva Davari Dolatabadi

Graduate Theses and Dissertations

This work focuses on the investigation of gate-defined quantum dots in two-dimensional transition metal dichalcogenide tungsten diselenide (WSe2) as a means to unravel mesoscopic physical phenomena such as valley-contrasting physics in WSe2 flakes and its potential application as qubit, as well as realizing gate-controlled quantum dots based on elementaltellurium nanostructures which may unlock the topological nature of the host material carriers such as Weyl states in tellurium nanowires.The fabrication and characterization of gate-defined hole quantum dots in monolayer and bilayer WSe2 are reported. The gate electrodes in the device design are located above and below the WSe2 nanoflakes to accumulate …


Cell Division Dynamics Of Escherichia Coli In Extreme Environments, Steven P. Murray Dec 2022

Cell Division Dynamics Of Escherichia Coli In Extreme Environments, Steven P. Murray

Graduate Theses and Dissertations

Life is remarkable in how resilient it can be. Many organism, classified as ex- tremophiles, can not only survive in extreme environments, but they can thrive in them. In the search for extraterrestrial life, the best candidates to harbor life exist with some kind of extreme condition. Europa, for example, is a favorite for the possibility of accommodating life as we know it within our solar system. Thought there is believed to be a liquid ocean under its icy surface, this habitat would be under immense pressures and high salinity. To best know where to look for extraterrestrial life, it …


Generation Of Phase Transitions Boundaries Via Convolutional Neural Networks, Christopher Alexis Ibarra Dec 2022

Generation Of Phase Transitions Boundaries Via Convolutional Neural Networks, Christopher Alexis Ibarra

Open Access Theses & Dissertations

Accurate mapping of phase transitions boundaries is crucial in accurately modeling the equation of state of materials. The phase transitions can be structural (solid-solid) driven by temperature or pressure or a phase change like melting which defines the solid-liquid melt line. There exist many computational methods for evaluating the phase diagram at a particular point in temperature (T) and pressure (P). Most of these methods involve evaluation of a single (P,T) point at a time. The present work partially automates the search for phase boundaries lines utilizing a machine learning method based on convolutional neural networks and an efficient search …


Application Of Flo-Sic To F-Electron Systems: Sixth Row Elements And Ligated Molecules, Alexander Irun Johnson Dec 2022

Application Of Flo-Sic To F-Electron Systems: Sixth Row Elements And Ligated Molecules, Alexander Irun Johnson

Open Access Theses & Dissertations

Density functional theory - the most widely used theoretical method to study atoms,molecules, and solids - suffers from the well-known self-interaction error. A solution to the problem was suggested by Perdew and Zunger [1], who showed the self-interaction error can be removed with self-interaction correction. In 2014, Pederson showed a unitary transformation can be performed on the Kohn-Sham orbitals to generate Fermi-Löwdin orbitals which improve atomization energies, and avoid the computational costs of solving the localization equations.[2] This method is known as the Fermi-Löwdin Orbital Self-Interaction Correction (FLO-SIC). Until now, the FLO-SIC methodology has been used for atoms not containing …


Probability Distributions Of The Scalar Potential, Candace Mathews Dec 2022

Probability Distributions Of The Scalar Potential, Candace Mathews

Legacy Theses & Dissertations (2009 - 2024)

In the study of cosmological inflation, string theory and supersymmetry have motivated a wide range of possible inflationary models. These models can be parameterized by a scalar potential V, which is a function of N scalar fields, and determines cosmological parameters such as the vacuum stability and energy density. In principle, we can determine V through high energy physics, such as string theory. In practice, though we may not know the details of V we might have clues about a distribution of plausible V’s, which we can build statistics on to further analyze. The purpose of this thesis defense is …


Turning Density Functional Theory Calculations Into Molecular Mechanics Simulations : Establishing The Fluctuating Density Model For Rna Nucleobases, Christopher A. Myers Dec 2022

Turning Density Functional Theory Calculations Into Molecular Mechanics Simulations : Establishing The Fluctuating Density Model For Rna Nucleobases, Christopher A. Myers

Legacy Theses & Dissertations (2009 - 2024)

Molecular mechanics (MD) simulations and density functional theory (DFT) have been the backbone of computational chemistry for decades. Due to its accuracy and computational feasibility, DFT has become the go-to method for theoretically predicting interaction energies, polarizability, and other electronic properties of small molecules at the quantum mechanical level. Although less fundamental than DFT, molecular mechanics (MM) algorithms have been just as influential in the fields of biology and chemistry, owing their success to the ability to compute measurable, macroscopic quantities for systems with tens of thousands to hundreds of thousands of atoms at a time. Nevertheless, MD simulations would …


A Study Of Electron Plasma Oscillations Using The Nimrod Code, Mckay Murphy Dec 2022

A Study Of Electron Plasma Oscillations Using The Nimrod Code, Mckay Murphy

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

A plasma, whether ”hot” or ”cold,” magnetized or unmagnetized, electrostatic or electromagnetic, exhibits normal modes of oscillation. Critical to understanding the stability of a plasma is the study of these normal modes. Waves originate from the long-range electric interactions between charged particles. This work will consider a class of waves known as Langmuir waves. These waves occur when a group of electrons are displaced with respect to the ions, with the electric Coulomb force playing the role of the restoring force of the oscillation [1]. Since the mass of ions is much greater than that of electrons, we can approximate …