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D-Orbital Occupancy Of Transition Metal Oxides By X-Ray Absorption Near Edge Structure (Xanes), Eric Kurywczak

Seton Hall University Dissertations and Theses (ETDs)

XANES L₂ and L₃-edge X-Ray Absorption Near Edge Spectra (XANES) for 4d and 5d row transition metals (TM) oxides are assumed to be directly reflecting unoccupied d orbitals influenced by the local symmetry of the metal ion. XANES L₂- and L₃-edge data analysis through non-linear curve fitting allows for a unique, efficient look at the structural eccentricities of transition metal oxides. In this way it is possible to determine the oxidation state of a material as well as its site symmetry. We have used non-linear least-squares fitting across the near-edge region …

Additive Modulation Of Dna-Dna Interactions By Interstitial Ions, Wei Meng, Raju Timsina, Abby Bull, Kurt Andresen, Xiangyun Qiu

Physics and Astronomy Faculty Publications

Quantitative understanding of biomolecular electrostatics, particularly involving multivalent ions and highly charged surfaces, remains lacking. Ion-modulated interactions between nucleic acids provide a model system in which electrostatics plays a dominant role. Using ordered DNA arrays neutralized by spherical cobalt3+ hexammine and Mg2+ ions, we investigate how the interstitial ions modulate DNA-DNA interactions. Using methods of ion counting, osmotic stress, and x-ray diffraction, we systematically determine thermodynamic quantities, including ion chemical potentials, ion partition, DNA osmotic pressure and force, and DNA-DNA spacing. Analyses of the multidimensional data provide quantitative insights into their interdependencies. The key finding of this study is that …

Density Functional Theory Calculations Of Al Doped Hafnia For Different Crystal Symmetry Configurations, Joshua Steier

Seton Hall University Dissertations and Theses (ETDs)

Dogan et al.[1], investigated the causes of ferroelectricity in doped hafnia using ab initio methods. Similarly, we investigated the stability of Al doped hafnia using quantum mechanical methods.

There are many different phases of Hafnia: monoclinic, tetragonal, cubic and orthorhombic. Starting with the monoclinic phase of Hafnia, Hafnia undergoes phase transitions which result in different space groups. The temperature at which the tetragonal phase is induced is 2000 K and cubic phase is induced at 2900 K[1]. Different dielectric constants vary from phase to phase. The average dielectric constants are highest for the cubic and tetragonal phases. In order to …

Quantitative Fluorescence Imaging For Investigation And Treatment Of Disease, Lemoyne Michael Habimana-Griffin

McKelvey School of Engineering Graduate Student Theses & Dissertations

Molecular imaging is a powerful tool that enables interrogation of basic molecular mechanisms, diagnosis of disease, guidance of therapeutic modalities and monitoring of treatment response. Among the various imaging modalities, optical imaging is particularly suited for preclinical molecular imaging owing to its high sensitivity, lack of exposure to ionizing radiation, low cost, portability and scalability of imaging from the microscopic to macroscopic scale. In particular, fluorescence molecular tomography (FMT) provides quantitative 3D reconstructions of fluorescence distributions down to picomole quantities allowing for whole animal molecular imaging. In this work, FMT is applied to detect disease-specific molecular probes, to monitor and …

First-Principles Studies Of Anion Engineering In Functional Ceramics, Steven Timothy Hartman

McKelvey School of Engineering Graduate Student Theses & Dissertations

Ceramic materials display a wide variety of valuable properties, such as ferroelectricity, superconductivity, and magnetic ordering, due to the partially covalent bonds which connect the cations and anions. While many breakthroughs have been made by mixing multiple cations on a sublattice, the equivalent mixed-anion ceramics have not received nearly as much attention, despite the key role the anion plays in the materials’ properties. There is great potential for functional ceramics design using anion engineering, which aims to tune the materials properties by adding and removing different types of anions in existing classes of ceramic materials. In this dissertation, I present …

Studies Of Maximum Supercooling And Stirring In Levitated Liquid Metallic Alloys, Mark Edward Sellers

Arts & Sciences Graduate Student Theses and Dissertations

Nucleation—or the formation of some cluster in a medium undergoing a phase transition—is usually the initial step in a phase transition. However, this process is still not fully understood, as outstanding questions related to the role of structure, local order, and diffusion remain unanswered. Systematic supercooling studies on metallic liquids performed using electrostatic and electromagnetic (ESL and EML, respectively) will be presented and discussed within the context of several nucleation theories, such as the Classical Nucleation Theory, Diffuse Interface Theory, and Coupled-Flux theory. To study the role of diffusion on nucleation, studies on the International Space Station using the on-board …

Supertiger Elemental Abundances For The Charge Range $41 \Leq Z \Leq 56$, Nathan Elliot Walsh

Arts & Sciences Graduate Student Theses and Dissertations

No abstract provided.

Thermophysical Properties And Phase Transformations In Metallic Liquids And Silicate Glasses, Daniel Christian Van Hoesen

Arts & Sciences Graduate Student Theses and Dissertations

The first quantitative measurements of the electrical resistivity in binary metallic liquids, used to probe local order in the liquid, are reported in this dissertation. The electrical resistivity is very sensitive to short and medium range ordering because the electron mean free path is approximately the same length scale as the atomic spacing. Particular attention is given to the resistivity value at a crossover temperature that, based on molecular dynamics (MD) simulations, is the onset of cooperative motion in liquid alloys. Experimental evidence for the crossover is found in measurements of the shear viscosity, a dynamical property. An indication of …

Measurement, Dissipation, And Quantum Control With Superconducting Circuits, Patrick Harrington

Arts & Sciences Graduate Student Theses and Dissertations

The interaction between a superconducting circuit and its environment can cause decoherence. However, interactions with an environment are necessary for quantum state preparation and measurement. Through the dynamics of open quantum systems, the environment is a resource to control and readout superconducting circuit states. I present an experimental result demonstrating qubit state stabilization from engineered dissipation with a microwave photonic crystal. In addition, I discuss the statistical arrow of time in the dynamics of continuous quantum measurement. These results demonstrate an interplay between open quantum system dynamics and statistics, which highlights the role of both dissipation and measurement for quantum …

Applications Of Nonlinear Dynamics, And Critical Phenomena To Measure Neural Populations Using Inputs To Single Neurons, James Kenneth Johnson

Arts & Sciences Graduate Student Theses and Dissertations

A compelling vision for the future of neuroscience is the ability to sense neural activity throughout the bulk of the brain with exquisite resolution. Popular visions usually include intricate electrode technology intruding into the neuropil, meandering along nerve tracts, and sensing the whole brain. These popular visions stem from the belief that we must always have an outsider’s perspective of neural activity. According to this belief the closest thing neuroscientists can achieve to an insider’s perspective is to shadow every neuron (or almost every neuron) with an electrical or optical recording device. Yet, the brain naturally has an expansive sensor …

Cherenkov Gamma Ray Detectors On High-Energy-Density Systems, Kevin Daniel Meaney

Physics & Astronomy ETDs

High energy density (HED) systems are some of the most extreme environments ever created by mankind. Systems with pressures greater than 1 MBar can only be created by a handful of devices on earth, often utilizing high intensity lasers or pulsed power machines. HED systems offer a view into an extreme form of matter only seen in stellar cores, supernovas and other powerful astrophysical systems. Creating HED systems on Earth offer the possibility, if the physics and technology can be matured, to one day create a fusion power plant. If a system is hot and dense enough, the fusion reaction …

The Primary Volatile Composition Of Comet C/2015 Er61 (Panstarrs), Aaron Butler

Theses

In the outer edges of the solar system exist two regions: the Kuiper belt and Oort cloud. These two regions have a high amount of icy bodies (comets) orbiting the Sun. Comets located within the Oort cloud and Kuiper belt contain an ancient codex to the solar systems contents, before the formation of our solar system. Presented are near-infrared, high-resolution (λ/Δλ ~40000) data obtained from the immersion-grating echelle spectrograph iSHELL at the 3m NASA Infrared Telescope Facility (IRTF) in Maunakea, Hawaii of the Oort cloud comet C/2015 ER61 (PANSTARRS). Observations took place on April 15 and 17 in 2017 while …

Supercdms: Energy Calibration Of A Ge Hv Particle Detector, Salamong Xiong, Vuk Mandic, Matthew Fritts, Nicholas Mast, Jacob Nelson

Macalester Journal of Physics and Astronomy

The goal of the SuperCDMS collaboration is to directly detect dark matter. Weakly Interacting Massive Particles (WIMPs) are potential candidates. To detect WIMPs, it is important to be able to predict how a Ge/Si particle detector will respond to a dark matter signal. In particular, it is necessary to calibrate the recoil energy measured by these detectors. This paper presents evidence for dark matter, a description of the detector operation, and procedures used to analyze measured data from a SuperCDMS-HV Ge particle detector using Am-241 and a PuBe neutron source. Due to high event rate, criteria were developed to remove …

Nitrogen Vacancy Center Optical Magnetometry Of A Barium-Iron-Cobalt Superconductor, William Setterberg

Macalester Journal of Physics and Astronomy

Experimentally probing the intrinsic properties of superconductors—such as the London penetration depth λ and the critical fields H_c1 and H_c2—poses a difficult task. Various sample- and measurement-related factors can impact the efficacy of results obtained for λ or H_c1, such as perturbations to the magnetic properties of a superconducting sample or crystalline defects. One measurement technique that can minimize the impact of both of these issues is known as Nitrogen Vacancy (NV) center magnetometry. In this work, we use NV center magnetometry to perform minimally-invasive measurements of the lower critical field H_c1 and the …

Probing The Magnetic Fields In Cosmic Web Filaments, Andrew L. Mizener

Macalester Journal of Physics and Astronomy

We present a project to constrain the properties of magnetic fields in Cosmic Web filaments. We first perform rotation measure (RM) synthesis on 24 S-band Karl G Jansky Very Large Array (VLA) observations of moderate-redshift active galactic nuclei (AGN). These observations are combined with an existing catalog of Cosmic Web filaments in order to determine the number of filaments a given sight-line passes near or through. By tracking how observables such as rotation measure and polarization fraction change as a function of the number of intervening cosmic web filaments, we take the first steps towards providing observational constraints on the …

Shape Model Of Potentially Hazardous Asteroid 1981 Midas From Radar And Lightcurve Observations, Riley Mcglasson

Macalester Journal of Physics and Astronomy

We report observations of potentially hazardous, Apollo-class asteroid 1981 Midas, which passed 0.090 au from Earth (35 lunar distances) on March 21, 2018. During this close approach, Midas was observed by radar both from the Arecibo Observatory on March 21 through 25 (five nights), and from NASA's Goldstone Deep Space Communications Complex on March 19 and 21. These radar observations yielded one-dimensional continuous-wave spectra and two-dimensional delay-Doppler images. In addition, there have been optical lightcurve observations of Midas during four apparitions (1987, 1992, 2004, and 2018), which showed a rotation period of 5.22 hours. Midas has an absolute magnitude of …

A Search For Pulsars Towards The Galactic Center, Jacob W. Hetrick, Kunal Mooley, Preshanth Jagannathan

Macalester Journal of Physics and Astronomy

We present observations from two separate methods for observing the Galactic Center in an attempt to characterize its pulsar and neutron star populations. A persistent puzzle of the past 20 years has been the lack of pulsar detections towards the Galactic Center, specifically within a few parsecs of the central supermassive black hole Sgr A*. This object is bright in the total intensity of its polarized emission, but is very weakly linearly polarized. We take advantage of these circumstances in an experimental search technique where we utilize the Faraday effect in an attempt to detect high rotation measure (RM) point …

Design And Modal Analysis Of An Ultra-Wideband Receiver For Green Bank Observatory, Alyssa Bulatek

Macalester Journal of Physics and Astronomy

The next generation of radio receivers for astronomy will be marked by tenfold improvements in sensitivity. These sensitive receivers will be useful for the detection of broadband fast radio bursts and other transients as well as the efficient discovery of radio recombination lines among many other scientific pursuits. One contribution to these improvements is an increase to decade receiver bandwidths. The Green Bank Observatory (GBO) is currently in the process of fabricating a new ultra-wideband (UWB; 0.7 to 4.2 GHz) receiver for the Green Bank Telescope (GBT). The UWB receiver will be used by the North American Nanohertz Observatory for …

Alfalfa Harvest: Hi Imaging And 3d Modeling Of Candidate Local Group Dwarf Galaxies, Lilly Bralts-Kelly, Susie Paine, Elizabeth A. K. Adams, John M. Cannon

Macalester Journal of Physics and Astronomy

Isolated neutral hydrogen (HI) clouds, or "ultra-compact high-velocity clouds" (UCHVCs), form a small subset of detections by the Arecibo Legacy Fast ALFA (ALFALFA) blind extragalactic survey. These systems, if located within ~1 Mpc, would populate the lowest-mass end of the HI mass function. Subsequent optical imaging has revealed that some of these UCHVCs harbor associated (thought sparse) stellar populations, suggesting that they may be some of the most extreme galaxies known in the Local Volume, with properties akin to ultra-faint dwarf galaxies but with significant neutral gas reservoirs. In this work, we investigate the neutral hydrogen properties of six UCHVC …

Leoncino And Ugc 5186, Josh Bartz

Macalester Journal of Physics and Astronomy

AGC 198691 is commonly known as the Leoncino Dwarf and is one of the most metal poor galax- ies known. An Arecibo observation in 2011 first suggested that Leoncino could be gravitationally interacting with its neighbor UGC 5186. In this paper new VLA data is used to examine the H I com- ponent of both galaxies to determine their gravitational relationship. Although the VLA could not confirm intragalactic gas seen by Aricebo, the H I density and velocity components are strong indirect evidence of gravitational interaction. UGC 5186 has a large gaseous arm reaching in the direction of Leoncino. Additionally …

A Novel Method For Computations Of Ratios Of Jet Cross Sections In Perturbative Quantum Chromodynamics, Connor Waits

Mathematics Senior Capstone Papers

The strong interaction is the force responsible for binding quarks to form hadrons, such as protons and neutrons, and also for binding protons and neutrons to form the nuclei of atoms. The properties of the strong interaction can be studied in particle collisions from measurements of the production rates of collimated sprays of particles, called jets. In particular, the ratio of the number of collisions that produce three jets over the number of collisions that produce two jets is a direct measure of the strength of the strong interaction. This strength is quantified by the strong coupling constant, αs. Determinations …

Spectral Observations Of The 2019 South American Total Solar Eclipse, Sarah Auriemma

Honors Program Theses and Projects

On July 2, 2019, a total solar eclipse was visible in parts of Chile and Ar-gentina. I joined the Solar Wind Sherpas, an international group of scientists,engineers, students, and eclipse enthusiasts, to South America to make obser-vations of the solar corona (the Sun’s upper atmosphere) during the eclipse.The Sherpas were split into three teams along the path of totality and my groupwas stationed at Mamalluca Observatory in Vicuna, Chile. One of the instru-ments we used at this side was a three-channel (red, green, and blue) spectrom-eter designed by A. Ding, of Hawai’i’s Institute for Astronomy. Spectra from thecorona can be …

Examining The Effect Of El Nino Phenomena And Pacific Sea Surface Temperature On The Climate Of The Glacierized White Mountains In Peru, Emily Reardon

Honors Program Theses and Projects

The purpose of this study is to determine if there is a correlation between the El Ni~no Southern Oscillation, sea surface temperatures (SST) and the climate of the Rio Santa Basin. This study is an important step in understanding the dynamics of the glaciers as a critical control on hydrological features in alpine Andes Valleys. Temperature and precipitation measurements pulled from ground based weather stations in the Rio Santa drainage basin were aggregated, synchronized, and correlated with the changes in the Pacific ocean SST o the coast of Peru and into the central Pacific. The expectation is that we will …

Image Processing Of Narrow Band Solar Eclipse Data Using Python And Maxim Dl, Rydia Hayes-Huer

Honors Program Theses and Projects

On July 2, 2019, a total solar eclipse (TSE) was observable from Chile and Argentina. In Chile, I worked alongside the Solar Wind Sherpas, an international group led by Dr. Shadia Habbal from the University of Hawai'i Institute for Astronomy, to make observations of the solar corona and gather information about its elemental composition. Narrow band data were collected for Fe XI, Fe XIV, and Ar X. Data collected during TSE observations can be used to help solve two puzzles in solar physics: the coronal heating problem and the mechanisms responsible for the fast and slow solar winds. Narrow band …

Investigatin Actin-Myosin Mechanics To Model Heart Disease Using Fluorescence Microscopy And Optical Trapping, Justin Edward Reynolds

Honors Theses

Hypertrophic cardiomyopathy (HCM) is a hereditary disease in which the myocardium becomes hypertrophied, making it more difficult for the heart to pump blood. HCM is commonly caused by a mutation in the β-cardiac myosin II heavy chain. Myosin is a motor protein that facilitates muscle contraction by converting chemical energy from ATP hydrolysis into mechanical work and concomitantly moving along actin filaments. Optical tweezers have been used previously to analyze single myosin biophysical properties; however, myosin does not work as a single unit within the heart. Multiple myosin interacts to displace actin filaments and do not have the same properties …

Determining The Kinetic Isotope Effect Of Ruthenium Compound Ru(Bpy)₂(Bpyno)(Pf₆)₂ Using Artificial Photosynthesis, Alexandra I. Kirkvold

Honors Thesis

The world’s demand for energy is ever-increasing, but its fuel resources are being depleted at an alarming rate. A potential solution for this crisis lies in using ruthenium-based compounds to produce hydrogen for use in fuel cells. This research uses the process of artificial photosynthesis to learn more about a promising ruthenium-based compound, Ru(bpy)₂(bpyNO)(PF₆)₂. The experiment tests the reaction for oxygen production in both H₂O and D₂O to determine the Kinetic Isotope Effect of the compound and, thus, aid future research working to understand the reaction mechanisms. The analysis shows that the reaction demonstrates an inverse …

The Mosdef Survey: Kinematic And Structural Evolution Of Star-Forming Galaxies At 1.4 ≤ Z ≤ 3.8, Sedona H. Price, Mariska Kriek, Guillermo Barro, Alice E. Shapley, Naveen A. Reddy, William R. Freeman, Alison L. Coil, Irene Shivaei, Mojegan Azadi, Laura De Groot, Brian Siana, Bahram Mobasher, Ryan L. Sanders, Gene C.K. Leung, Tara Fetherolf, Tom O. Zick, Hannah Übler, Natascha M. Förster Schreiber

Pacific Faculty Work

We present ionized gas kinematics for 681 galaxies at z &tild; 1.4-3.8 from the MOSFIRE Deep Evolution Field survey, measured using models that account for random galaxy-slit misalignments together with structural parameters derived from CANDELS Hubble Space Telescope (HST) imaging. Kinematics and sizes are used to derive dynamical masses. Baryonic masses are estimated from stellar masses and inferred gas masses from dust-corrected star formation rates (SFRs) and the Kennicutt-Schmidt relation. We measure resolved rotation for 105 galaxies. For the remaining 576 galaxies we use models based on HST imaging structural parameters together with integrated velocity dispersions and baryonic masses to …

Building A Light Current Voltage Characterization Setup For Pulsed Laser Diodes, Alec A. Milford

Honors Program Theses and Projects

III-V laser dies are the main integrated light sources used in photonic integrated chips (PIC). Before incorporating these lasers in PICs, it is important to measure their performance and efficiency. The efficiency of these devices can be calculated from their light-current-voltage (L-I-V) characteristics. In this thesis, I will assemble the components of the probe station for the pulsed LIV setup, which are the pulse generator to drive the laser with current, temperature controller device to vary the laser’s operating temperature, and optical spectrum analyzer in order to characterize the laser’s emission wavelength. Initially this thesis was meant to report how …

Tz' Production At Hadron Colliders, Marco Guzzi, Nikolaos Kidonakis

Faculty Articles

We study the production of a single top quark in association with a heavy extra Z' at hadron colliders in new physics models with and without flavor-changing neutral-current (FCNC) couplings. We use QCD soft-gluon resummation and threshold expansions to calculate higher-order corrections for the total cross section and transverse momentum distributions for t Z' production. The impact of the uncertainties due to the structure of the proton and scale dependence is also analyzed.

Disorder By Design: A Data-Driven Approach To Amorphous Semiconductors Without Total-Energy Functionals, Dil K. Limbu, Stephen R. Elliott, Raymond Atta-Fynn, Parthapratim Biswas

Faculty Publications

X-ray diffraction, Amorphous silicon, Multi-objective optimization, Monte Carlo methods. This paper addresses a difficult inverse problem that involves the reconstruction of a three-dimensional model of tetrahedral amorphous semiconductors via inversion of diffraction data. By posing the material-structure determination as a multiobjective optimization program, it has been shown that the problem can be solved accurately using a few structural constraints, but no total-energy functionals/forces, which describe the local chemistry of amorphous networks. The approach yields highly realistic models of amorphous silicon, with no or only a few coordination defects (≤1%), a narrow bond-angle distribution of width 9–11.5°, and an electronic gap …