Digital Commons Network^™

Stability Of Two-Dimensional Magnetic Skyrmions, Amel Derras-Chouk

Dissertations, Theses, and Capstone Projects

Magnetic skyrmions are whirls formed by magnetic moments in a crystal. They have attracted attention largely due to their topological protection, which provides an avenue for technology like next-generation memory storage. The idea of topologically protected solutions of a quantum field theory was originally proposed by Tony Skyrme when he developed a model to explain the stability of hadrons in particle physics. His work has extended far beyond his original intent to several areas of condensed matter physics. Here we focus on skyrmions in magnetic materials.

Skyrme's original theory modeled excitations which exist in three spatial dimensions, a requirement for …

Removal Of Anisotropic Background From Neutral Pion And Tagged Direct Photon–Hadron Correlations Of Au+Au 200 Gev Collisions, Zachary Rowan

Dissertations, Theses, and Capstone Projects

A reaction plane dependent event mixing technique is developed to remove the collective background from two particle correlation measurements in heavy ion collisions. The method eliminates the need for any external flow measurements and is well suited for studying the path length dependence of particle production in quark-gluon plasma. Central to mid-central, as well as in vs out-of-plane, per neutral pion trigger integrated away-side hadron yield comparisons are made. Results suggest a significant path length dependent partonic energy loss in the medium. A tagging method is also introduced to measure the direct photon yield for various collision criteria. Direct photon …

Astrophysics, Cosmology And Particle Phenomenology At The Energy Frontier, Jorge Fernandez Soriano

Dissertations, Theses, and Capstone Projects

This dissertation consists of two parts, treating significantly separated fields. Each part consists on several chapters, each treating a somewhat isolated topic from the rest. In each chapter, I present some of the work developed during my passage through the graduate program, which has mostly been published elsewhere.

Part I – Cosmic Rays and Particle Physics

• Chapter 1: In this chapter we present an introduction to the topic of cosmic ray physics, with an special focus on the so-called ultra high energy cosmic rays: their potential origins, effects during their propagation between their sources and Earth, the different techniques used …

Electron Transport In Quantum Systems With Interaction, Sara Abedi

Dissertations, Theses, and Capstone Projects

No abstract provided.

Magnetic Field Effects On The Physics Of Neutron Stars, Aric A. Hackebill

Dissertations, Theses, and Capstone Projects

In the context of neutron stars (NS), dense-magnetized quark and hadron models have been well studied under the assumption that the system's pressures are isotropic. However, the pressures determined from semi-classical statistical averaging of the energy momentum tensor in the presence of a uniform background magnetic field are anisotropic with different pressures arising along and perpendicular to the magnetic field direction. Since large magnetic fields are expected to be present in the interior of NS, it is important to understand the roll the pressure anisotropy plays. While considering the pressure anisotropy, we revisit some important calculations in NS physics.

We …

Stochastic Modeling Of Flows In Membrane Pore Networks, Binan Gu

Dissertations

Membrane filters provide immediate solutions to many urgent problems such as water purification, and effective remedies to pressing environmental concerns such as waste and air treatment. The ubiquity of applications gives rise to a significant amount of research in membrane material selection and structural design to optimize filter efficiency. As physical experiments tend to be costly, numerical simulation and analysis of fluid flow, foulant transport and geometric evolution due to foulant deposition in complex geometries become particularly relevant. In this dissertation, several mathematical modeling and analytical aspects of the industrial membrane filtration process are investigated. A first-principles mathematical model for …

Performance Analysis Of The Dominant Mode Rejection Beamformer, Enlong Hu

Dissertations

In array signal processing over challenging environments, due to the non-stationarity nature of data, it is difficult to obtain enough number of data snapshots to construct an adaptive beamformer (ABF) for detecting weak signal embedded in strong interferences. One type of adaptive method targeting for such applications is the dominant mode rejection (DMR) method, which uses a reshaped eigen-decomposition of sample covariance matrix (SCM) to define a subspace containing the dominant interferers to be rejected, thereby allowing it to detect weak signal in the presence of strong interferences. The DMR weight vector takes a form similar to the adaptive minimum …

Diagnostics Of Energy Release In Solar Flares With Radio Dynamic Imaging Spectroscopy, Yingjie Luo

Dissertations

Studies of the magnetic energy release and conversion process lie at the core of solar flare physics. Radio observations serve as a unique diagnostic method. In this dissertation, taking advantage of broadband radio dynamic imaging spectroscopy observations made by the Karl G. Jansky Very Large Array (VLA), studies are carried out on the flare energy release processes using different types of radio emissions.

The VLA is a general-purpose radio observatory located in New Mexico, which provides high-quality radio dynamic imaging spectroscopic observations with an ultra-fast time cadence. In the first study, stochastic decimetric radio spike bursts are observed by the …

Falcon Neuro: An Event-Based Sensor On The International Space Station, Matthew G. Mcharg, Richard L. Balthazor, Matthew P. Borg, Brian J. Mcreynolds, David H. Howe, Colin J. Maloney, Daniel O'Keefe, Rayomand Bam, Gabriel Wilson, Paras Karki, Alexandre Marcireau, Gregory Cohen

Student Publications

We report on the Falcon neuro event-based sensor (EBS) instrument that is designed to acquire data from lightning and sprite phenomena and is currently operating on the International Space Station. The instrument consists of two independent, identical EBS cameras pointing in two fixed directions, toward the nominal forward direction of flight and toward the nominal Nadir direction. The payload employs stock DAVIS 240C focal plane arrays along with custom-built control and readout electronics to remotely interface with the cameras. To predict the sensor’s ability to effectively record sprites and lightning, we explore temporal response characteristics of the DAVIS 240C and …

Hydrogen Behavior At Crystalline/Amorphous Interface Of Transparent Oxide Semiconductor And Its Effects On Carrier Transport And Crystallization, Julia E. Medvedeva, Kapil Sharma, Bishal Bhattarai, Mariana I. Bertoni

Physics Faculty Research & Creative Works

The role of disorder and particularly of the interfacial region between crystalline and amorphous phases of indium oxide in the formation of hydrogen defects with covalent (In-OH) or ionic (In-H-In) bonding are investigated using ab initio molecular dynamics and hybrid density-functional approaches. The results reveal that disorder stabilizes In-H-In defects even in the stoichiometric amorphous oxide and also promotes the formation of deep electron traps adjacent to In-OH defects. Furthermore, below-room-temperature fluctuations help switch interfacial In-H-In into In-OH, creating a new deep state in the process. This H-defect transformation limits not only the number of free carriers but also the …

System Design For The Quantification Of Microbial Motility In Extreme Environments, Megan Marie Dubay

Dissertations and Theses

Motility of microorganisms is understudied but provides useful insights into their behavior. Organisms' ability to move autonomously changes how they interact with their environment--finding nutrients, interacting with other organisms, and avoiding unfavorable conditions. Understanding motility features can also be used to identify specific species, such as the identification of Vibrio cholerae in human samples. Motility might also be used as evidence of life existing in even the most extreme environments on Earth, and possibly beyond. Specialized microscopy systems can be required to examine the motility of microorganisms due to the nature of the environments to which the instruments are exposed. …

Coupled Oscillators: Protein And Acoustics, Angelique N. Mcfarlane

Theses

This work encompassed three different vibrational energy transfer studies of coupled resonators (metal, topological, and microtubule comparison) inspired by the lattices of microtubules from regular and cancerous cells. COMSOL Multiphysics 5.4 was utilized to design the experiment. The simulation starts with an acoustic pressure study to examine the vibrational modes present in coupled cylinders, representing α-, β-tubulin heterodimers. The Metal Study consisted of 3 models (monomer, dimer, and trimer) to choose the correct height (40 mm) and mode (Mode 1) for study. The Topological Study was run to predict and understand how the lattice structure changes over a parametric sweep …

Mechanologic: Designing Mechanical Devices That Compute, Michelle Berry

Dissertations - ALL

Despite their initial success and impact on the development of the modern computer, mechanical computers were quickly replaced once electronic computers became viable. Recently, there has been increased interest in designing devices that compute using modern and unconventional materials. In this dissertation, we investigate multiple ways to realize a mechanical device that can compute, with a main focus on designing mechanical equivalents for wires and transistors. For our first approach at designing mechanical wires, we present results on the propagation of signals in a soft mechanical wire composed of bistable elements. When we send a signal along bistable wires that …

Investigation Of Holographic Lattice Theories, Muhammad Asaduzzaman

Dissertations - ALL

The Anti-de Sitter/Conformal Field theory (AdS/CFT) correspondence, also known as holography, has been the focus of a great deal of interest and research for the last two decades. It has improved our understanding of general relativity and quantum field theories simultaneously through the interplay between these two different kinds of theories. However, there are still many aspects of holography that we do not understand or demand further analysis. Perturbative quantum field theory and perturbative metric expansion techniques are not equipped to investigate holography in some of the most interesting regimes such as the strongly interacting gravitational theory in anti-de Sitter …

Geometry Of Discrete And Continuous Bounded Surfaces, Kyung Eun Kim

Dissertations - ALL

We work on reconstructing discrete and continuous surfaces with boundaries using length constraints. First, for a bounded discrete surface, we discuss the rigidity and number of embeddings in three-dimensional space, modulo rigid transformations, for given real edge lengths. Our work mainly considers the maximal number of embeddings of rigid graphs in three-dimensional space for specific geometries (annulus, strip). We modify a commonly used semi-algebraic, geometrical formulation using Bézout's theorem, from Euclidean distances corresponding to edge lengths. We suggest a simple way to construct a rigid graph having a finite upper bound. We also implement a generalization of counting embeddings for …

Rocket Measurements Of Electron Energy Spectra From Earth’S Photoelectron Production Layer, Glyn A. Collinson, Alex Glocer, Dennis Chornay, Robert Mitchell, Rob Pfaff, Tim Cameron, Et. Al.

Publications

Photoelectrons are crucial to atmospheric physics. They heat the atmosphere, strengthen 28 planetary ambipolar electric fields, and enhance the outflow of ions to space. However, 29 there exist only a handful of measurements of their energy spectrum near the peak of 30 photoproduction. We present calibrated energy spectra of pristine photoelectrons at their 31 source by a prototype Dual Electrostatic Analyzer (DESA) instrument flown on July 11 32 2021 aboard the Dynamo-2 sounding rocket (NASA № 36.357). Photopeaks arising from 33 30.4nm He-II spectral line were observed throughout the flight above 120km. DESA also 34 successfully resolved the rarely observed …

Arrival Directions Of Cosmic Rays Above 32 Eev From Phase One Of The Pierre Auger Observatory, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, I. Norwood, A. Puyleart, Et. Al.

Michigan Tech Publications, Part 1

A promising energy range to look for angular correlations between cosmic rays of extragalactic origin and their sources is at the highest energies, above a few tens of EeV (1 EeV 1018 eV). Despite the flux of these particles being extremely low, the area of ∼3000 km2 covered at the Pierre Auger Observatory, and the 17 yr data-taking period of the Phase 1 of its operations, have enabled us to measure the arrival directions of more than 2600 ultra-high-energy cosmic rays above 32 EeV. We publish this data set, the largest available at such energies from an integrated exposure of …

Developing Optical Devices And Projects For Teaching Engineering, Nathan D. Lemke, John Mccauley, Tristan E. Noble, Grace Riermann, Ellesa St. George, Nathan C. Lindquist, Keith R. Stein, Karen Irene Rogers

Physics and Engineering Faculty Publications

We are creating a suite of tools and techniques based on optics to be used for teaching a variety of engineering topics. Each tool is intended for non-expert use and without the need for high-end equipment such as vibration-free optical tables. Here we report progress on three such tools: image-plane digital holography for measuring mechanical deformation; schlieren imaging of convective flows using a smart phone; and a simple optical communication protocol using LabVIEW. We will present the designs of the tools and preliminary results from teaching engineering labs and projects with these tools. Specific courses impacted to date include Fluid …

Distance Estimates To Evolved Stars Using Infrared Emission And Verification And Validation Of The Plasma Code Empire, Brandon M. Medina

Physics & Astronomy ETDs

Gaining insight into the structure and dynamics of the Milky Way is important for understanding the universe on a large scale. Evolved stars on the Asymptotic Giant Branch are useful for studying the Milky Way because their emission is peaked in the infrared, where interstellar extinction effects are not as dominant. To further understand the physical properties of these objects like luminosity and investigate the Galaxy's structure, we need distance estimates. Obtaining distance estimates for these evolved stars via trigonometric parallax measurements is time-consuming, so infrared surveys studying Asymptotic Giant Branch stars can benefit from other distance estimate methods. In …

Adsorption Of Helium And Hydrogen On Triphenylene And 1,3,5-Triphenylbenzene, Bergmeister Bergmeister, Kollotzek Kollotzek, Florent Calvo, Elisabeth Gruber, Fabio Zappa, Paul Scheier, Olof E. Echt

Faculty Publications

The adsorption of helium or hydrogen on cationic triphenylene (TPL, C₁₈H₁₂), a planar polycyclic aromatic hydrocarbon (PAH) molecule, and of helium on cationic 1,3,5-triphenylbenzene (TPB, C₂₄H₁₈), a propeller-shaped PAH, is studied by a combination of high-resolution mass spectrometry and classical and quantum computational methods. Mass spectra indicate that He_nTPL⁺ complexes are particularly stable if n = 2 or 6, in good agreement with the quantum calculations which show that for these sizes the helium atoms are strongly localized on either side of the central carbon ring for n = …

Investigating D-Dimensional Behavior Of Higher-Order Qcd Vacuum Condensates, Tong Mu

Student Work

In the context of QCD sum-rules, hadronic properties are related to QCD correlation functions of composite operators. These QCD correlation functions are evaluated using an operator product expansion, where the non-perturbative values multiplied by perturbatively-calculated Wilson coefficients. We present here an updated calculation of the Wilson coefficient of the mixed QCD condensate calculated in d-dimensions, up to $O(m^3)$ in quark mass.

High Mass Star Formation And Methanol Masers, Nathanael Wilson

College of Science and Health Theses and Dissertations

Class I and Class II methanol (CH3OH) masers are believed to be good indicators for regions where high mass stars are being formed. High mass stars are important because they inuence the evolution of the Galaxy, but many details of their formation remain unknown. I present an investigation into the association of Class I and Class II CH3OH masers with high mass star formation in our Galaxy, in particular the evolutionary stages at which they occur. To do so, I have compared data on high mass star forming regions from the ATLASGAL survey with catalogs of Class I and Class …

Promoting The Humidity Sensing Capabilities Of Titania Nanorods/Rgo Nanocomposite Via De-Bundling And Maximizing Porosity And Surface Area Through Lyophilization, Mohamed Morsy

Nanotechnology Research Centre

No abstract provided.

The Missing Link Between Standing-And Traveling-Wave Resonators, Qi Zhong, Haoqi Zhao, Liang Feng, Kurt Busch, Sahin K. Özdemir, Ramy El-Ganainy

Michigan Tech Publications, Part 1

Optical resonators are structures that utilize wave interference and feedback to confine light in all three dimensions. Depending on the feedback mechanism, resonators can support either standing-or traveling-wave modes. Over the years, the distinction between these two different types of modes has become so prevalent that nowadays it is one of the main characteristics for classifying optical resonators. Here, we show that an intermediate link between these two rather different groups exists. In particular, we introduce a new class of photonic resonators that supports a hybrid optical mode, i.e. at one location along the resonator the electromagnetic fields associated with …

Molecular Characterization Of Esbls And Ampc Β-Lactamases In Bacteria Isolated From Currency Notes Circulating In Mosul City, Iraq, Mahmood Zeki Al-Hasso, Shakir Ghazi Gergees, Zahraa Khairialdeen Mohialdeen

Karbala International Journal of Modern Science

The Iraqi currency notes circulating in Mosul city were evaluated for the occurrence of ESBLs and AmpC b-lactamaseproducing bacteria. Four hundred and twenty-two Gram-positive and negative bacterial isolates with different antimicrobial resistance profiles were recovered from 250 samples collected during the period from April to July 2021, among which 150 isolates (35.5%) were multi-drug resistant (MDR). The study found that 16.4% and 14.8% of Gram negative isolates were positive for ESBLs and AmpC phenotypic detection tests, respectively. Interestingly, 6.6% of the isolates were simultaneously positive for both tests. Molecular characterization was carried out using PCR technique to determine the prevalent …

Molecular Docking And Dynamics Simulation Studies To Predict Multiple Medicinal Plants’ Bioactive Compounds Interaction And Its Behavior On The Surface Of Denv-2 E Protein, Arief Hidayatullah, Wira Eka Putra, Muhaimin Rifa’I, Sustiprijatno Sustiprijatno, Diana Widiastuti, Muhammad Fikri Heikal, Hendra Susanto, Wa Ode Salma, Hilal Mulyadi

Karbala International Journal of Modern Science

The envelope protein (E) is a fusion class II protein that is essential for DENV fusion. We use two active compounds derived from commonly used plants in Indonesia: galangin and kaempferide. We ran a docking and 1000 ps molecular dynamic analysis with normal physiological parameters. During the simulation, galangin and kaempferide binding sites fluctuated. But chloroquine has lesser ligand mobility, hence keeping contact with fusion loops, whereas both drugs lose contact with hydrophobic pockets. However, the two active compounds have a more stable ligand configuration. Less than 2 Å alterations were seen in the RMSF simulation of the protein E …

Deep Space And The Quantum Mechanical Case: A Study Of Stars To The First Bsu Direct Measurement Of A Singular Photon, Darius Desnoes

Honors Program Theses and Projects

While it is known that physics can be split into several different fields, it may be foreign to see how different fields of physics operate hand in hand with one another to solve complex problems. For instance, Maxwell’s equations involving E&M for the propagation of electro-magnetic waves can be used to understand light-based interferometry for astrophysics, which directly led to the creation of intensity-based interferometry. Eventually, the measurements and equations made by intensity-based interferometry would produce groundbreaking strides in quantum mechanics through the direct measurement of singular particles. An in-depth analysis of each of these connections and how they involved …

Using Optical Tweezersto Probe Dna Polymerase Kappa’S Binding Mechanism To Dna, Joshua Watts

Honors Program Theses and Projects

The integrity of our DNA is constantly under threat from many internal and external factors. If the cell cannot properly protect the integrity of DNA, errors (lesions) in DNA may form which can lead to cancer. Most of these lesions serve as a roadblock to the protein, DNA polymerase (Pol), that replicates the DNA during cell division. The mechanism that is employed to read through these errors is called translesion DNA synthesis (TLS). During this process, a special class of DNA polymerases known as TLS DNA Pols that can tolerate and bypass the lesions in DNA are employed by the …

Measurement Of The Branching Fractions Of The B+ → Η′ℓ+Νℓ And B+ → Η′ℓ+Νℓ Decays With Signal-Side Only Reconstruction In The Full Q2 Range, U. Gebauer, C. Beleño, A. Frey, I. Adachi, K. Adamczyk, H. Aihara, S. Al Said, D. M. Asner, H. Atmacan, T. Aushev, R. Ayad, V. Babu, S. Bahinipati, P. Behera, K. Belous, J. Bennett, M. Bessner, V. Bhardwaj, B. Bhuyan, Milind Purohit, Et. Al.

Faculty Publications

The branching fractions of the decays B⁺ → ηl⁺νl and B⁺ → ηl⁺νl are measured, where l is either an electron or a muon, using a data sample of 711 fb⁻¹ containing 772 × 10⁶ BB̅ pairs collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e⁺e⁻ collider. To reduce the dependence of the result on the form factor model, the measurement is performed over the entire q² range. The resulting branching fractions are B(B⁺ → η ℓ + ν ℓ)=(2.83 …

Measurement Of The Branching Fractions Of The B+ → Ηl+ Νl And B+ → Η0l+ Νl Decays With Signal-Side Only Reconstruction In The Full Q2 Range, U. Gebauer, C. Beleño, A. Frey, I. Adachi, K. Adamczyk, H. Aihara, S. Al Said, D. M. Asner, H. Atmacan, T. Aushev, R. Ayad, V. Babu, S. Bahinipati, P. Behera, K. Belous, J. Bennett, M. Bessner, V. Bhardwaj, B. Bhuyan, Milind Purohit, Et. Al.

Faculty Publications

The branching fractions of the decays B⁺ → ηl+νl and B+ → η0 lþνl are measured, where l is either an electron or a muon, using a data sample of 711 fb⁻¹ containing 772 × 10⁶ BB̅ pairs collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e⁺e⁻ collider. To reduce the dependence of the result on the form factor model, the measurement is performed over the entire q² range. The resulting branching fractions are B(B⁺ → ηlþνl)=(2.83 ± 0.55_(stat.) ± 0.34_(syst.) )× 10 …