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A Simulation And Experimental Validation Of Third-Order Coma In Nodal Aberrationtheory With A Cassegrain Telescope, Özgür Karci

Turkish Journal of Physics

This study presents a simulation and experimental validation of third-order coma in Nodal Aberration Theory (NAT) with a custom-designed Cassegrain system. The Cassegrain system uses a piezo-driven flexure tool to align the telescope's secondary mirror with respect to the primary mirror. This alignment mechanism is also used to misalign the telescope's secondary mirror to induce the intentional aberrations. The third-order Fringe Zernike coma (Z$_{7/8}$) was simulated utilizing the Cassegrain telescope's real ray-trace model (e.g., in Code V) and analyzed for both the telescope's nominal aligned and misaligned states. The simulated aberration of third-order coma was induced utilizing the secondary mirror …

Analysis And Design Of Infrared Fiber Bundles For Large Field-Of-View Thermal Imaging, Cesar A. Lopez-Zelaya

Honors Undergraduate Theses

During the DARPA SCENICC program, J. Ford, et al., demonstrated that CFBs provide a compelling route to compact, wide angle imagers. Monocentric lenses readily provide diffraction-limited images over wide field but onto a hemispherically curved image surface. They demonstrated visible CFBs can be tapered, cut and polished to relay curved images to flat sensors. We have shown that this provides a volumetric imaging efficiency a hundredfold larger than bulk optics can produce; a hundred times the resolution in the same volume or a hundred times less volume for the same resolution. Ford's work leveraged commercial fiber bundles available for the …

Observation Of New Particle Formation In The Northern Hemisphere At Altitude From 4 To 20 Km, Mohamed Saad

Electronic Theses and Dissertations

New particle formation (NPF) is investigated using measurements of aerosol size distributions and meteorological variables made in two continents, including USA and Europe. Despite the considerably different aerosol particle abundances among the sites, a common relationship was found between the characteristics of NPF events and the air mass convective and/or advective transport. CO and O3 act as tracers of tropospheric and stratospheric air, respectively, their statistical relationship can be used to quantify air mass characteristics and origins. The mixing ratio values of CO increased within the upper troposphere layer before/during NPF events, which may serve as an indicator of occurring …

Energy And Greenhouse Gas Savings For Leed-Certified U.S. Office Buildings Using Weighted Regression, Tian Liang

Honors Papers

In this study, we studied the energy consumption and greenhouse gas emission performance of LEED-certified office buildings. We obtained the 2016 energy consumption and greenhouse gas emission data for 4002 office buildings from nine major US cities, including 522 buildings that we identified as LEED-certified. We discovered that LEED buildings used significantly more electricity percentagewise as their energy source. We also discovered that the locations and ages of buildings have significant effect on their performance. We removed the effect of locations and building ages using weighted regression. Our result showed that LEED office buildings used 11% less site energy, 9% …

The Lady Be Good: A Case Study In Radio Frequency Direction Finders, With Supplemental Material For On-Line Appendix, Gregory A. Dilisi, Kenneth Kane, Robert A. Leskovec, Alison Chaney*

2021 Faculty Bibliography

No abstract provided.

Analyzing The Optical Properties Of Hemozoin To Expand The Disease Detection Applications Of A Magneto-Optical Device (Mod), Kyle Blasinsky

Senior Honors Projects

Hemozoin crystals are the basis of a new approach for efficient, cost-effective malaria detection. Clinical success of malaria detection with a magneto-optical device (MOD) motivates quantification of the optical interactions forming the basis of the detection mechanism. The MOD is used to measure the intensity of polarized light transmitted through a sample of hemozoin suspended in phosphate-buffered saline, subject to a magnetic field, 𝐵􁈬 ⃗, that can be turned on and off. According to Beer’s law, ratios of transmitted light with different polarization directions and with on and off as a function of hemozoin concentration were related to change in …

Compressible Hydrodynamics Of Few Body Optical Vortices, Jasmine M. Andersen

Electronic Theses and Dissertations

The ubiquity of vortices nearly rivals that of the innumerable fluids and spaces in which they live. Not only do they exist in systems such as superfluids, superconductors, optical fields, or cold atomic gases, for example, but they also exist in our atmospheres, oceans, and even in our veins. This makes understanding and accurately predicting the dynamics of vortices in various systems a relevant and meaningful endeavor.

From a typical hydrodynamic perspective, vortices move within a given fluid because of the background fluid density and phase gradients at the vortex location. However, we find that these gradients alone are insufficient …

Magnetism In Curved Geometries, R. Streubel, Evgeny Y. Tsymbal, P. Fischer

Evgeny Tsymbal Publications

No abstract provided.

An Investigation Of Uncertainties In Intensity Modulated Radiation Therapy, Cory Knill

Wayne State University Dissertations

Introduction: The treatment of cancer using intensity modulated radiation therapy (IMRT) is complex, involving many sub-processes to commission a treatment platform and treat patients. Uncertainties within the individual sub-process can lead to inaccurate treatments and sub-optimal patient outcomes. This research focused on minimizing uncertainties throughout IMRT commissioning and treatments. Methods: Five sub-processes were selected for uncertainty reduction: 1) optimizing radiation-imaging coincidence of the treatment machine, 2) improving the statistical model used to analyze IMRT commissioning data, 3) reducing the effect of ion recombination in IMRT quality assurance measurements, 4) improving the correlation between IMRT quality assurance results and patient-specific delivery …

Interaction Of Alpha-Crystallin With Four Major Phospholipids Of Eye Lens Membranes, Raju Timsina, Nawal K. Khadka, David Maldonado, Laxman Mainali

Physics Faculty Publications and Presentations

It is well-studied that the significant factor in cataract formation is the association of α-crystallin, a major eye lens protein, with the fiber cell plasma membrane of the eye lens. The fiber cell plasma membrane of the eye lens consists of four major phospholipids (PLs), i.e., phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), and sphingomyelin (SM). Despite several attempts to study the interaction of α-crystallin with PLs of the eye lens membrane, the role of individual PL for the binding with α-crystallin is still unclear. We recently developed the electron paramagnetic resonance (EPR) spin-labeling method to study the binding of α-crystallin …

Liquid Crystal Flat Optics For Near-Eye Displays, Tao Zhan

Electronic Theses and Dissertations, 2020-2023

Augmented reality (AR) and virtual reality (VR) displays, considered as the next-generation information platform, have shown great potential to revolutionize the way how we interact with each other and the digital world. Both AR and VR are disruptive technologies that can enable numerous applications in education, healthcare, design, training, entertainment, and engineering. Among all the building blocks of these emerging devices, near-eye displays (NEDs) play a critical role in the entire system, through which we can perceive the virtual world as the real one. However, the visual experience offered by existing NED technologies is still far from satisfying the human …

The Continuum And Leading Twist Limits Of Parton Distribution Functions In Lattice Qcd, Joseph Karpie, Kostas Orginos, Anatoly Radyushkin, Savvas Zafeiropoulos, For The Hadstruc Collaboration

Physics Faculty Publications

In this study, we present continuum limit results for the unpolarized parton distribution function of the nucleon computed in lattice QCD. This study is the first continuum limit using the pseudo-PDF approach with Short Distance Factorization for factorizing lattice QCD calculable matrix elements. Our findings are also compared with the pertinent phenomenological determinations. Inter alia, we are employing the summation Generalized Eigenvalue Problem (sGEVP) technique in order to optimize our control over the excited state contamination which can be one of the most serious systematic errors in this type of calculations. A crucial novel ingredient of our analysis is the …

Accumulation-Type Ohmic Van Der Waals Contacts To Nearly Intrinsic Wse2, Upendra Rijal

Wayne State University Dissertations

We report the fabrication of ohmic van der Waals (vdW) contacts to WSe2 using degenerately p-doped MoS2 (p+-MoS2) as a contact-metal. We demonstrate in WSe2 field-effect transistors (FETs) that accumulation-type ohmic contacts and high device performance are achieved without electrostatically gating the drain/source contact regions despite the nearly intrinsic nature of WSe2. Back-gated WSe2 FETs with p+-MoS2 bottom-contacts (which screen the back-gate electric field in the drain/source regions) exhibit linear output characteristics, a high on/off ratio of 108, and a high two-terminal field-effect mobility up to ~200 cm2V-1s-1 at room temperature. Our theoretical modeling reveals that the p+-MoS2/WSe2 vdW contact …

On The Information Content In Unresolved Imaging, Zhean Shen

Electronic Theses and Dissertations, 2020-2023

Imaging is almost synonymous with optics. Imaging is the process of using light to form a tangible or visible representation, an imitation (imitari) of a material property. There are many situations, however, where one can only aspire to 'sense making' rather than forming an image per se. In other words, objects cannot be directly resolved by conventional intensity-based imaging, a situation commonly referred to as 'unresolved imaging'. However, there is still information retained in other properties of light, which can be exposed by other means. In this thesis I will discuss two typical situations: subwavelength and multiple scattering, which are …

Understanding The Mechanisms Of Surface Chemical Reactions By Tracking Unstable Intermediate Species, Md Afjal Khan Pathan

Electronic Theses and Dissertations, 2020-2023

The detection of intermediate species formed during surface chemical reactions is essential because it can provide critical information about the reaction mechanisms at surfaces and interfaces. Therefore, the overarching goal of this research was to understand the mechanisms of surface catalytic, photocatalytic, and photoinduced reactions by monitoring the intermediate species formed during these reactions. To understand the initial steps of the carbon monoxide hydrogenation reaction on two-dimensional (2D) MoS2 and TaS2 materials, temperature programmed desorption and reaction are employed. Large-area 2D-MoS2 and 2D-TaS2 were prepared on a Cu(111) substrate under ultra-high vacuum conditions via physical vapor deposition. The highly crystalline …

Janus Solutions From Four-Dimensional N=4 Gauged Supergravity, Tissana Assawasowan

Chulalongkorn University Theses and Dissertations (Chula ETD)

No abstract provided.

Dales Objects: A Large Scale Benchmark Dataset For Instance Segmentation In Aerial Lidar, Nina M. Singer, Vijayan K. Asari

Electrical and Computer Engineering Faculty Publications

We present DALES Objects, a large-scale instance segmentation benchmark dataset for aerial lidar. DALES Objects contains close to half a billion hand-labeled points, including semantic and instance segmentation labels. DALES Objects is an extension of the DALES (Varney et al., 2020) dataset, adding additional intensity and instance segmentation annotation. This paper provides an overview of the data collection, preprocessing, hand-labeling strategy, and final data format. We propose relevant evaluation metrics and provide insights into potential challenges when evaluating this benchmark dataset. Finally, we provide information about how researchers can access the dataset for their use at go.udayton.edu/dales3d.

Tunable Optical Filter Using Phase Change Materials For Smart Ir Night Vision Applications, Remona Heenkenda, Keigo Hirakawa, Andrew Sarangan

Electro-Optics and Photonics Faculty Publications

In this paper we present a tunable filter using Ge2Sb2Se4Te1 (GSST) phase change material. The design principle of the filter is based on a metal-insulator-metal (MIM) cavity operating in the reflection mode. This is intended for night vision applications that utilize 850nm as the illumination source. The filter allows us to selectively reject the 850nm band in one state. This is illustrated through several daytime and nighttime imaging applications.

Multi-Functional Fluorescence Microscopy Via Psf Engineering For High-Throughput Super-Resolution Imaging, Jinhan Ren

Electronic Theses and Dissertations, 2020-2023

Image-based single cell analysis is essential to study gene expression levels and subcellular functions with preserving the native spatial locations of biomolecules. However, its low throughput has prevented its wide use to fundamental biology and biomedical applications which require large cellular populations in a rapid and efficient fashion. Here, we report a 2.5D microcopy (2.5DM) that significantly improves the image acquisition rate while maintaining high-resolution and single molecule sensitivity. Unlike serial z-scanning in conventional approaches, volumetric information is simultaneously projected onto a 2D image plane in a single shot by engineering the fluorescence light using a novel phase pattern. The …

Plasmonic Properties Of Nanopatterned Graphene, Muhammad Waqas Shabbir

Electronic Theses and Dissertations, 2020-2023

Graphene is an atomically thin two-dimensional material with carbon atoms arranged in a honeycomb lattice. It has been successfully mechanically exfoliated from graphite and characterized in 2004 by Andre Geim and Konstantin Novoselov at the University of Manchester, UK. While suspended graphene holds the world record in mobility exceeding 100,000 cm2/Vs, which means that graphene could increase the operating frequency of electronic devices up to the THz regime. For example, imaging computer chips running at a few THz frequency, which would be about 1000 times faster than current chips. However, there are two main obstacles for using graphene in electronics …

High Speed Modulation Characteristics Of Semiconductor Nanolasers And Coupled Ring Laser Systems, Chi Xu

Electronic Theses and Dissertations, 2020-2023

Optical communication systems require light sources that can be modulated with high speeds. However, the modulation bandwidth of laser diodes is typically limited by an intrinsic value, its relaxation resonance frequency. In order to circumvent this limitation, a number of methods have been proposed to boost the modulation speed, including optical injection locking, quantum dots lasers with large differential gain, push-pull modulation in composite lasers. This dissertation explores two new approaches for enhancing the direct modulation bandwidth of semiconductor quantum well laser diodes. Lasers with strong spontaneous emission have been shown to exhibit a high-speed performance theoretically. It is expected …

Exploring New Materials As Promising Electrocatalysts For The Generation Of A Clean And Renewable Energy Source, Tyler Campbell

Electronic Theses and Dissertations, 2020-2023

This work presents the research of myself, my advising professor, and our collaborators in first-principles studies of several catalytic materials for improving the efficiency and economics of hydrogen fuel cells, focusing on the oxygen reduction reaction (ORR) at the cathode, CO removal and the hydrogen oxidation reaction (HOR) at the anode, and the redox reactions used for water splitting through photocatalysis. We use a computational design approach to analyze the reaction thermodynamics, applying density functional theory (DFT) for most calculations. We find that, through a subversion of the linear scaling approximation for surface reactivity, an Au monolayer deposited on the …

Mot-Based Lifetime Measurements Of Potassium-39 5p1/2 And 5p3/2 States, Huan Q. Bui

Honors Theses

This thesis presents measurements of the lifetimes of 5p1/2 and 5p3/2 of K39 via exciting a cloud of K39 atoms in a magneto-optical trap by a linearly-polarized pulse of 405 nm light followed polarization-specific, time-resolved fluorescence detection. We find that $\tau_{5p1/2} = $ 138.8 $\pm$ 1.6 ns, which is consistent with past measurements \cite{triumf}, \cite{berends} and calculations \cite{safranova}. The $\tau_{5p3/2}$ measurement is naturally more involved since quantum beats due to hyperfine and Zeeman effect are present. Our observation of $\tau_{5p3/2} =$ 137.6 $\pm$ 3.1 ns and $\tau_{5p3/2} =$ 136.0 $\pm$ 2.4 ns, obtained from two slightly different approaches, are compared …

Yyy Dynamic Tuning Of Viscoelastic Hydrogels With Carbonyl Iron Microparticles Reveals The Rapid Response Of Cells To Three-Dimensional Substrate Mechanics, Kiet A. Tran, Emile Kraus, Andy T. Clark, Alex Bennet, Katarzyna Pogoda, Xuemei Cheng, Andrejs Cēbers, Paul A. Janmey, Peter A. Galie

Physics Faculty Research and Scholarship

Current methods to dynamically tune three-dimensional hydrogel mechanics require specific chemistries and substrates that make modest, slow, and often irreversible changes in their mechanical properties, exclude the use of protein-based scaffolds, or alter the hydrogel microstructure and pore size. Here, we rapidly and reversibly alter the mechanical properties of hydrogels consisting of extracellular matrix proteins and proteoglycans by adding carbonyl iron microparticles (MPs) and applying external magnetic fields. This approach drastically alters hydrogel mechanics: rheology reveals that application of a 4000 Oe magnetic field to a 5 mg/mL collagen hydrogel containing 10 wt % MPs increases the storage modulus from …

The Entropic Dynamics Of Relativistic Quantum Fields In Curved Space-Time, Selman Ipek

Legacy Theses & Dissertations (2009 - 2024)

It has often been the case in history that the laws of physics have been used as the framework for understanding and implementing information processing. The tacit assumption is that the laws of physics are fundamental and that the notion of information is derived from these laws. Here we take the opposite view: the laws of physics are an application of the rules for processing information. The inferential framework of entropic dynamics (ED) has previously been developed by A. Caticha for the purposes of understanding and deriving quantum theory, in much the same way that E.T. Jaynes used the MaxEnt …

Vacuum Polarization Energy Of The Kinks In The Sinh-Deformed Models, Ishmael Takyi, Benedict Barnes, Joseph Ackora-Prah

Turkish Journal of Physics

We compute the one-loop quantum corrections to the kink energies of the sinh-deformed $\phi^{4}$ and $\varphi^{6}$ models in one space and one time dimensions. These models are constructed from the well-known polynomial $\phi^{4}$ and $\varphi^{6}$ models by a deformation procedure. We also compute the vacuum polarization energy to the non-polynomial function $U(\phi)=\frac{1}{4}(1-\sinh^{2}\phi)^{2}$. This potential approaches the $\phi^{4}$ model in the limit of small values of the scalar function. These energies are extracted from scattering data for fluctuations about the kink solutions. We show that for certain topological sectors with nonequivalent vacua the kink solutions of the sinh-deformed models are destabilized.

Deriving Weak Deflection Angle By Black Holes Or Wormholes Usinggauss-Bonnet Theorem, Yashmitha Kumaran, Ali̇ Övgün

Turkish Journal of Physics

In this review, various researches on finding the bending angle of light deflected by a massive gravitating object which regard the Gauss-Bonnet theorem as the premise have been revised. Primarily, the Gibbons and Werner method is studied apropos of the gravitational lensing phenomenon in the weak field limits. Some exclusive instances are deliberated while calculating the deflection angle, beginning with the finite-distance corrections on nonasymptotically flat spacetimes. Effects of plasma medium is then inspected to observe its contribution to the deflection angle. Finally, the Jacobi metric is explored as an alternative method, only to arrive at similar results. All of …

A Valence-Bond Operator Algebra For Quantum Spin Models And Its Applications, Huu Tran Do

Electronic Theses and Dissertations

The Heisenberg Hamiltonian is the prototype model for quantum magnetism. The Hamilto- nian includes exchange couplings between vector spins, which are the intrinsic magnetic moments of localized electrons. The classical energy between any pair of interacting spins can be minimized by aligning them parallel (ferromagnetic case) or antiparallel (antiferromagnetic), depending on the sign of the coupling. But quantum fluctuations play a key role, and a full quantum mechanical treatment of the many-body system is generally required. Finding the exact ground-state energy and wave function of isotropic antiferromagnetic (AFM) systems for an arbitrary spin-S and lattice morphology is still a challenging …

Dynamics For Discretized Gravity In The Causal Set Approach, Benjamin Pilgrim

Electronic Theses and Dissertations

Causal set theory is an approach to quantum gravity which replaces the continuous spacetime manifold with a discrete set of points and a partial order. In this work, I will focus on causal sets embeddable in two-dimensional manifolds, and define an action based on chains which in the continuum limit replicates the Einstein-Hilbert action; furthermore, I will propose a variational principle based on this action and numerically show it can distinguish nonflat manifoldlike causal sets from the most common type of nonmanifoldlike causal sets. I will then supplement this action with a boundary term similar to the Gibbons-Hawking-York boundary term …

Measurement Of The Cross Section Of Top Quark Pairs Produced In Association With A Photon In Lepton + Jets Events At √S = 13 Tev With Full Runii Cms Data, Nabin Poudyal

Wayne State University Dissertations

The inclusive production cross section of top quark pairs in association with a photon is measured in proton-proton collisions at the LHC with 13 TeV energy using the full RunII data collected by CMS in 2016, 2017, and 2018 with a total corresponding integrated luminosity of 137 fb −1 . The relative fraction of ttγ events normalized to inclusive tt production is measured. The cross section measurement provides important information about the electromagnetic coupling of the standard model top quark and is sensitive to physics beyond the standard model. The analysis is carried out in the in semileptonic decay channel …