Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 7021 - 7050 of 302419

Full-Text Articles in Physical Sciences and Mathematics

Multicolor Bipartite Ramsey Number Of Double Stars, Gregory M. Decamillis Jan 2024

Multicolor Bipartite Ramsey Number Of Double Stars, Gregory M. Decamillis

Honors Undergraduate Theses

The core idea of Ramsey theory is that complete disorder is impossible. Given a large structure, no matter how complex it is, we can always find a smaller substructure that has some sort of order. For positive integers $n, m$, the double star $S(n,m)$ is the graph consisting of the disjoint union of two stars $K_{1,n}$ and $K_{1,m}$ together with an edge joining their centers. The $k$-color bipartite Ramsey number of $ S(n,m)$, denoted by $r_{bip}(S(n,m);k)$, is the smallest integer $N$ such that, in any $k$-coloring of the edges of the complete bipartite graph $K_{N,N}$, there is a monochromatic copy …


Searching For Black Holes In The Galactic Center, Caden Zaccardi Jan 2024

Searching For Black Holes In The Galactic Center, Caden Zaccardi

Honors Undergraduate Theses

Due to the high extinction along the plane of the Milky Way towards the Galactic Center (GC), it is useful to look at objects that are bright in the near-infrared (near-IR) to obtain data with Earth-based instruments. To identify X-ray Binary (XRB) counterparts towards the GC, we used near-IR spectra from the Large Binocular Telescope (LBT). After reducing the LUCI/LBT spectra with the superFATBOY (sFB) pipeline, we compared our near-IR spectra to previously matched IR and X-ray sources in the GC (DeWitt, 2011). Particularly, we looked for H and He emission lines, which indicate signs of a hard radiation field …


Frieze And Tiling Groups In The Lorentz-Minkowski Plane, Michael O. Lynch Jan 2024

Frieze And Tiling Groups In The Lorentz-Minkowski Plane, Michael O. Lynch

Honors Undergraduate Theses

In this thesis, there is a presentation of the isometries from the Lorentz-Minkowski Plane and a solution to the Frieze Patterns. There is a suggestion for a solution for the Tiling Patterns. Since the construction of these mathematical structures is well understood in the Euclidean plane, one can follow a similar approach to the construction of such objects to find the unique number of groups that describe all possible frieze patterns while there is a suggestion of the number for the tiling case. There is a reflection of these results in a computational and cosmological context.


Counting Linearly Polarized Gluons With Lattice Qcd, Shuai Zhao Jan 2024

Counting Linearly Polarized Gluons With Lattice Qcd, Shuai Zhao

Physics Faculty Publications

We outline an approach to calculate the transverse-momentum-dependent distribution of linearly polarized gluons inside an unpolarized hadron on the lattice with the help of large momentum effective theory. To achieve this purpose, we propose calculating a Euclidean version of the degree of polarization for a fast-moving hadron on the lattice, which is ultraviolet finite, and no soft function subtraction is needed. It indicates a practical way to explore the distribution of the linearly polarized gluons in a proton and the linearly polarized gluon effects in hadron collisions on the lattice.


Accelerating Markov Chain Monte Carlo Sampling With Diffusion Models, N. T. Hunt-Smith, W. Melnitchouk, F. Ringer, N. Sato, A. W. Thomas, M. J. White Jan 2024

Accelerating Markov Chain Monte Carlo Sampling With Diffusion Models, N. T. Hunt-Smith, W. Melnitchouk, F. Ringer, N. Sato, A. W. Thomas, M. J. White

Physics Faculty Publications

Global fits of physics models require efficient methods for exploring high-dimensional and/or multimodal posterior functions. We introduce a novel method for accelerating Markov Chain Monte Carlo (MCMC) sampling by pairing a Metropolis-Hastings algorithm with a diffusion model that can draw global samples with the aim of approximating the posterior. We briefly review diffusion models in the context of image synthesis before providing a streamlined diffusion model tailored towards low-dimensional data arrays. We then present our adapted Metropolis-Hastings algorithm which combines local proposals with global proposals taken from a diffusion model that is regularly trained on the samples produced during the …


Beam Spin Asymmetry Measurements Of Deeply Virtual Π⁰ Production With Clas12, The Clas Collaboration, A. Kim, S. Diehl, K. Joo, V. Kubarovsky, P. Achenbach, Z. Akbar, J. S. Alvarado, Whitney R. Armstrong, H. Atac, H. Avakian, C. Ayerbe Gayoso, L. Barion, M. Battaglieri, I. Bedlinskiy, B. Benkel, A. Bianconi, A. S. Biselli, M. Bondi, M. Zureck, Et Al. Jan 2024

Beam Spin Asymmetry Measurements Of Deeply Virtual Π⁰ Production With Clas12, The Clas Collaboration, A. Kim, S. Diehl, K. Joo, V. Kubarovsky, P. Achenbach, Z. Akbar, J. S. Alvarado, Whitney R. Armstrong, H. Atac, H. Avakian, C. Ayerbe Gayoso, L. Barion, M. Battaglieri, I. Bedlinskiy, B. Benkel, A. Bianconi, A. S. Biselli, M. Bondi, M. Zureck, Et Al.

Physics Faculty Publications

The new experimental measurements of beam spin asymmetry were performed for the deeply virtual exclusive π0 production in a wide kinematic region with the photon virtualities Q2 up to 6.6 GeV2and the Bjorken scaling variable 𝓍B in the valence regime. The data were collected by the CEBAF Large Acceptance Spectrometer (CLAS12) at Jefferson Lab with longitudinally polarized 10.6 GeV electrons scattered on an unpolarized liquid-hydrogen target. Sizable asymmetry values indicate a substantial contribution from transverse virtual photon amplitudes to the polarized structure functions. The interpretation of these measurements in terms of the Generalized Parton Distributions …


Definition Of Fragmentation Functions And The Violation Of Sum Rules, John Collins, Ted C. Rogers Jan 2024

Definition Of Fragmentation Functions And The Violation Of Sum Rules, John Collins, Ted C. Rogers

Physics Faculty Publications

We point out a problem with the formulation and derivations of sum rules for quark fragmentation functions that impacts their validity in QCD, but which potentially points toward an improved understanding of final states in inclusive hard processes. Fragmentation functions give the distribution of final-state hadrons arising from a parton exiting a hard scattering, and the sum rules for momentum, electric charge, etc. express conservation of these quantities. The problem arises from a mismatch between the quark quantum numbers of the initial quark and the fact that all observed final-state hadrons are confined bound states with color zero. We point …


Magneto-Thermal Limitations In Superconducting Cavities At High Radio-Frequency Fields, I. Parajuli, G. Ciovati, A. Gurevich Jan 2024

Magneto-Thermal Limitations In Superconducting Cavities At High Radio-Frequency Fields, I. Parajuli, G. Ciovati, A. Gurevich

Physics Faculty Publications

The performance of superconducting radio-frequency Nb cavities at high radio-frequency (rf) fields in the absence of field emission can be limited by either a sharp decrease of the quality factor Q0(Bp) above peak surface magnetic fields Bp ∼100 mT or by a quench. We have measured Q0(Bp) at 2 K of several 1.3 GHz single-cell Nb cavities with different grain sizes, and with different ambient magnetic fields and cooldown rates below the critical temperature. Temperature mapping and a novel magnetic field mapping systems were used to find the location of “hot-spots” …


Double Distributions And Pseudodistributions, A. V. Radyushkin Jan 2024

Double Distributions And Pseudodistributions, A. V. Radyushkin

Physics Faculty Publications

We describe the approach to lattice extraction of generalized parton distributions (GPDs) that is based on the use of the double distribution (DD) formalism within the pseudodistribution framework. The advantage of using DDs is that GPDs obtained in this way have the mandatory polynomiality property, a nontrivial correlation between 𝓍 and ξ dependences of GPDs. Another advantage of using DDs is that the D-term appears as an independent entity in the DD formalism rather than a part of GPDs H and E. We relate the ξ dependence of GPDs to the width of the α profiles of the corresponding DDs …


Quantum Logic Control And Precision Measurements Of Molecular Ions In A Ring Trap: An Approach For Testing Fundamental Symmetries, Yan Zhou, Joshua O. Island, Matt Grau Jan 2024

Quantum Logic Control And Precision Measurements Of Molecular Ions In A Ring Trap: An Approach For Testing Fundamental Symmetries, Yan Zhou, Joshua O. Island, Matt Grau

Physics Faculty Publications

This paper presents an experimental platform designed to facilitate quantum logic control of polar molecular ions in a segmented ring ion trap, paving the way for precision measurements. This approach focuses on achieving near-unity state preparation and detection, as well as long spin-precession coherence. A distinctive aspect lies in separating state preparation and detection conducted in a static frame from parity-selective spin precession in a rotating frame. Moreover, the method is designed to support spatially and temporally coincident measurements on multiple ions prepared in states with different sensitivity to the new physics of interest. This provides powerful techniques to probe …


Evolution Of Efimov States, Sebastian M. Dawid, Md Habib E. Islam, Raúl A. Briceño, Andrew W. Jackura Jan 2024

Evolution Of Efimov States, Sebastian M. Dawid, Md Habib E. Islam, Raúl A. Briceño, Andrew W. Jackura

Physics Faculty Publications

The Efimov phenomenon manifests itself as an emergent discrete scaling symmetry in the quantum three-body problem. In the unitarity limit, it leads to an infinite tower of three-body bound states with energies forming a geometric sequence. In this work, we study the evolution of these so-called Efimov states using relativistic scattering theory. We identify them as poles of the three-particle 𝑆 matrix in the complex energy plane, and we study how they transform from virtual states through bound states to resonances when we change the interaction strength. We dial the scattering parameters toward the unitarity limit and observe the emergence …


Continuous-Variable Quantum Computation Of The O(3) Model In 1+1 Dimensions, Raghav G. Jha, Felix Ringer, George Siopsis, Shane Thompson Jan 2024

Continuous-Variable Quantum Computation Of The O(3) Model In 1+1 Dimensions, Raghav G. Jha, Felix Ringer, George Siopsis, Shane Thompson

Physics Faculty Publications

We formulate the O(3) nonlinear sigma model in 1+1 dimensions as a limit of a three-component scalar field theory restricted to the unit sphere in the large squeezing limit. This allows us to describe the model in terms of the continuous-variable (CV) approach to quantum computing. We construct the ground state and excited states using the coupled-cluster Ansatz and find excellent agreement with the exact diagonalization results for a small number of lattice sites. We then present the simulation protocol for the time evolution of the model using CV gates and obtain numerical results using a photonic quantum simulator. We …


The Present And Future Of Qcd, P. Achenbach, D. Adhikari, A. Afanasev, F. Afzal, C. A. Aidala, A. Al-Bataineh, D. K. Almaalol, M. Amaryan, D. Androić, W. R. Armstrong, M. Arratia, J. Arrington, A. Asaturyan, E. C. Aschenauer, H. Atac, H. Avakian, T. Averett, C. Ayerbe Gayoso, X. Bai, M. Zurek, Et. Al. Jan 2024

The Present And Future Of Qcd, P. Achenbach, D. Adhikari, A. Afanasev, F. Afzal, C. A. Aidala, A. Al-Bataineh, D. K. Almaalol, M. Amaryan, D. Androić, W. R. Armstrong, M. Arratia, J. Arrington, A. Asaturyan, E. C. Aschenauer, H. Atac, H. Avakian, T. Averett, C. Ayerbe Gayoso, X. Bai, M. Zurek, Et. Al.

Physics Faculty Publications

This White Paper presents an overview of the current status and future perspective of QCD research, based on the community inputs and scientific conclusions from the 2022 Hot and Cold QCD Town Meeting. We present the progress made in the last decade toward a deep understanding of both the fundamental structure of the sub-atomic matter of nucleon and nucleus in cold QCD, and the hot QCD matter in heavy ion collisions. We identify key questions of QCD research and plausible paths to obtaining answers to those questions in the near future, hence defining priorities of our research over the coming …


Field, Frequency, And Temperature Dependencies Of The Surface Resistance Of Nitrogen Diffused Niobium Superconducting Radio Frequency Cavities, P. Dhakal, B. D. Khanal, A. Gurevich, G. Ciovati Jan 2024

Field, Frequency, And Temperature Dependencies Of The Surface Resistance Of Nitrogen Diffused Niobium Superconducting Radio Frequency Cavities, P. Dhakal, B. D. Khanal, A. Gurevich, G. Ciovati

Physics Faculty Publications

We investigate the rf performance of several single-cell superconducting radio-frequency cavities subjected to low temperature heat treatment in nitrogen environment. The cavities were treated at temperature 120–165 °C for an extended period of time (24–48 h) either in high vacuum or in a low partial pressure of ultrapure nitrogen. The improvement in 𝑄0 with a 𝑄 rise was observed when nitrogen gas was injected at ∼300 °C during the cavity cooldown from 800 °C and held at 165 °C, without any degradation in accelerating gradient over the baseline performance. The treatment was applied to several elliptical cavities with frequency ranging …


Hubble Tension And Gravitational Self-Interaction, Corey Sargent, William Clark, Alexander Deur, Balša Terzić Jan 2024

Hubble Tension And Gravitational Self-Interaction, Corey Sargent, William Clark, Alexander Deur, Balša Terzić

Physics Faculty Publications

One of the most important problems vexing the ΛCDM cosmological model is the Hubble tension. It arises from the fact that measurements of the present value of the Hubble parameter performed with low-redshift quantities, e.g. the Type IA supernova, tend to yield larger values than measurements from quantities originating at high-redshift, e.g. fits of cosmic microwave background radiation. It is becoming likely that the discrepancy, currently standing at 5σ, is not due to systematic errors in the measurements. Here we explore whether the self-interaction of gravitational fields in General Relativity, which are traditionally neglected when studying the evolution …


Beam Correction For Multi-Pass Arcs In Ffa@ Cebaf: Status Update, A. Coxe, J. F. Benesch, R.M. Bodenstein, K. E. Deitrick, K. Price, T. Satogata Jan 2024

Beam Correction For Multi-Pass Arcs In Ffa@ Cebaf: Status Update, A. Coxe, J. F. Benesch, R.M. Bodenstein, K. E. Deitrick, K. Price, T. Satogata

Physics Faculty Publications

As design and simulation studies for the energy upgrade at the Continuous Electron Beam Accelerator Facility progress, both static and dynamic errors must be addressed. The current upgrade design introduces a pair of Fixed-Field Alternating-Gradient (FFA) recirculating arcs: one in the East recirculating arc, and one in the West. In the present design, each FFA arc supports six concurrent beam energies in the same beam pipe; these must be concurrently corrected for both static and dynamic errors. This document discusses the present beam correction strategies applied in simulation.


Mass And Isospin Breaking Effects In The Skyrme Model And In Holographic Qcd, Lorenzo Bartolini, Stefano Bolognesi, Sven Bjarke Gudnason, Tommaso Rainaldi Jan 2024

Mass And Isospin Breaking Effects In The Skyrme Model And In Holographic Qcd, Lorenzo Bartolini, Stefano Bolognesi, Sven Bjarke Gudnason, Tommaso Rainaldi

Physics Faculty Publications

We discuss how the quark masses and their mass splitting affect the baryons in the Skyrme model as well as the Witten-Sakai-Sugimoto (WSS) model. In both cases, baryons are described by solitonic objects, i.e., Skyrmions and instantons, respectively. After the quantization of their zero modes, the nucleons become quantum states of a rotor. We show how the quark mass affects the moment of inertia and we provide a semianalytic approach valid in the small-mass limit. Additionally, we show how the two lightest quarks’ mass splitting affects the moments of inertia of the Skyrmion and induces an isospin breaking effect. This …


Diffusion Model Approach To Simulating Electron-Proton Scattering Events, Peter Devlin, Jian-Wei Qiu, Felix Ringer, Nobuo Sato Jan 2024

Diffusion Model Approach To Simulating Electron-Proton Scattering Events, Peter Devlin, Jian-Wei Qiu, Felix Ringer, Nobuo Sato

Physics Faculty Publications

Generative artificial intelligence is a fast-growing area of research offering various avenues for exploration in high-energy nuclear physics. In this work, we explore the use of generative models for simulating electron-proton collisions relevant to experiments like the Continuous Electron Beam Accelerator Facility and the future Electron-Ion Collider (EIC). These experiments play a critical role in advancing our understanding of nucleons and nuclei in terms of quark and gluon degrees of freedom. The use of generative models for simulating collider events faces several challenges such as the sparsity of the data, the presence of global or eventwide constraints, and steeply falling …


Tmd Phenomenology With The Hso Approach, Tommaso Rainaldi, M. Boglione, J. O. Gonzalez-Hernandez, Ted C. Rogers Jan 2024

Tmd Phenomenology With The Hso Approach, Tommaso Rainaldi, M. Boglione, J. O. Gonzalez-Hernandez, Ted C. Rogers

Physics Faculty Publications

Transverse momentum dependent (TMD) observables are typically classified in terms of their contributions coming from different regions in transverse momentum. The low transverse momentum behavior is often ascribed to intrinsic nonperturbative properties of the hadron described by TMD factorization, while the large transverse momentum region can be computed using fixed order collinear perturbation theory. Combining both pictures in a consistent way presents challenges, for practical calculations as well as the interpretation of results. We discuss a recent approach that is designed to retain a physical interpretation in terms of hadron structure while alleviating tension with techniques used at much higher …


1/Q² Power Corrections To Tmd Factorization For Drell-Yan Hadronic Tensor, I. Balitsky Jan 2024

1/Q² Power Corrections To Tmd Factorization For Drell-Yan Hadronic Tensor, I. Balitsky

Physics Faculty Publications

I calculate 1/Q2 power corrections to unpolarized Drell-Yan hadronic tensor for electromagnetic (EM) current at large N-c and demonstrate the EM gauge invariance at this level.


Analytic Solutions Of The Dglap Evolution And Theoretical Uncertainties, A. Simonelli Jan 2024

Analytic Solutions Of The Dglap Evolution And Theoretical Uncertainties, A. Simonelli

Physics Faculty Publications

The energy dependence for the singlet sector of Parton Distributions Functions (PDFs) is described by an entangled pair of ordinary linear differential equations. Although there are no exact analytic solutions, it is possible to provide approximated results depending on the assumptions and the methodology adopted. These results differ in their sub-leading, neglected terms and ultimately they are associated with different treatments of the theoretical uncertainties. In this work, a novel analytic approach in Mellin space is presented and a new methodology for obtaining closed and exponentiated analytic solutions is devised. Different results for the DGLAP evolution at Next-Leading-Order are compared, …


Inclusive Reactions From Finite Minkowski Spacetime Correlation Functions, Marco A. Carrillo, Raúl A. Briceño, Alexandru M. Sturzu Jan 2024

Inclusive Reactions From Finite Minkowski Spacetime Correlation Functions, Marco A. Carrillo, Raúl A. Briceño, Alexandru M. Sturzu

Physics Faculty Publications

The need to determine scattering amplitudes of few-hadron systems for arbitrary kinematics expands a broad set of subfields of modern-day nuclear and hadronic physics. In this work, we expand upon previous explorations on the use of real-time methods, like quantum computing or tensor networks, to determine few-body scattering amplitudes. Such calculations must be performed in a finite Minkowski spacetime, where scattering amplitudes are not well defined. Our previous work presented a conjecture of a systematically improvable estimator for scattering amplitudes constructed from finite-volume correlation functions. Here we provide further evidence that the prescription works for larger kinematic regions than previously …


Solving The Homogeneous Bethe-Salpeter Equation With A Quantum Annealer, Filippo Fornetti, Alex Gnech, Tobias Frederico, Francesco Pederiva, Matteo Rinaldi, Alessandro Roggero, Giovanni Salmè, Sergio Scopetta, Michele Viviani Jan 2024

Solving The Homogeneous Bethe-Salpeter Equation With A Quantum Annealer, Filippo Fornetti, Alex Gnech, Tobias Frederico, Francesco Pederiva, Matteo Rinaldi, Alessandro Roggero, Giovanni Salmè, Sergio Scopetta, Michele Viviani

Physics Faculty Publications

The homogeneous Bethe-Salpeter equation (hBSE), describing a bound system in a genuinely relativistic quantum-field theory framework, was solved for the first time by using a D-Wave quantum annealer. After applying standard techniques of discretization, the hBSE, in ladder approximation, can be formally transformed in a generalized eigenvalue problem (GEVP), with two square matrices: one symmetric and the other nonsymmetric. The latter matrix poses the challenge of obtaining a suitable formal approach for investigating the nonsymmetric GEVP by means of a quantum annealer, i.e., to recast it as a quadratic unconstrained binary optimization problem. A broad numerical analysis of the proposed …


Towards Unpolarized Gpds From Pseudo-Distributions, Hervé Dutrieux, Robert G. Edwards, Colin Egerer, Joseph Karpie, Christopher Monahan, Kostas Orginos, Anatoly Radyushkin, David Richards, Eloy Romero, Savvas Zafeiropoulos Jan 2024

Towards Unpolarized Gpds From Pseudo-Distributions, Hervé Dutrieux, Robert G. Edwards, Colin Egerer, Joseph Karpie, Christopher Monahan, Kostas Orginos, Anatoly Radyushkin, David Richards, Eloy Romero, Savvas Zafeiropoulos

Physics Faculty Publications

We present an exploration of the unpolarized isovector proton generalized parton distributions (GPDs) Hud(x, ξ, t) and Eud(x, ξ, t) in the pseudo-distribution formalism using distillation. Taking advantage of the large kinematic coverage made possible by this approach, we present results on the moments of GPDs up to the order x3 — including their skewness dependence — at a pion mass mπ = 358 MeV and a lattice spacing a = 0.094 fm.


Id Numbers Of Lobster Graphs, Mark Anthony C. Tolentino, Luis Silvestre Jr, Richwell T. Chan Sim, Amir Jann Erikson Diga, Althea Julia R. Loyola Jan 2024

Id Numbers Of Lobster Graphs, Mark Anthony C. Tolentino, Luis Silvestre Jr, Richwell T. Chan Sim, Amir Jann Erikson Diga, Althea Julia R. Loyola

Mathematics Faculty Publications

No abstract provided.


Topics In Quantum Information, Complexity And Chaos, Debarghya Chakraborty Jan 2024

Topics In Quantum Information, Complexity And Chaos, Debarghya Chakraborty

Theses and Dissertations--Physics and Astronomy

This dissertation explores quantum information, the use of codes to describe quantum field theories, and introduces new concepts to characterize the dynamics of quantum many-body systems. The contributions of this dissertation are the following: 1) We constructed Narain Conformal Field Theories (CFTs) using additive codes, where the modular bootstrap constraints translate into algebraic conditions on the codes, extending previous approaches. This helps express key CFT data, including the torus partition function, in terms of codewords. We constructed optimal Narain CFTs for small central charges, and described CFT ensembles for asymptotically large central charge with large spectral gap. 2) We studied …


Implementation Of Prognosticator Algorithm For Initiation Of Serious Illness Discussions And Improving The Rate Of Palliative And Hospice Referrals, Joy Isebor Jan 2024

Implementation Of Prognosticator Algorithm For Initiation Of Serious Illness Discussions And Improving The Rate Of Palliative And Hospice Referrals, Joy Isebor

Doctor of Nursing Practice (DNP) Scholarly Projects

Context: Early serious illness conversations related to end-of-life and goals of care with seriously ill patients have been associated with improving patients' outcomes and quality of care (Bernacki et al., 2015). However, initiating these serious illness discussions has been challenging in the home-based primary care setting.

Objectives: To train and support home-based primary care clinicians in integrating best practices in serious illness discussions and decision-making engagement among patients sixty-five and older with serious illnesses, optimize the alignment between patient goals and the medical care they receive, improving their quality of life and the rate of palliative care and hospice referrals. …


Higher-Derivative Quantum Field Theory And Its Implications For Hawking Radiation And Nonlocality, Gordon Kanan Jan 2024

Higher-Derivative Quantum Field Theory And Its Implications For Hawking Radiation And Nonlocality, Gordon Kanan

Physics Dissertations

One of the fundamental equations of quantum field theory is the Klein-Gordon equation which can be constructed using irreducible representations of the Poincar ́e group and describes the dynamics of spin-0 matter. The higher derivative Klein- Gordon equations are also constructed using irreducible representations of the Poincar ́e group and are, thus, invariant under operations of this group. These higher derivative Klein-Gordon equations can be placed into two series depending on the power of the derivative, one for odd powers of the derivative and one for even powers, whose solu- tions yield timelike and spacelike fields. Applying these higher derivative …


Respiratory-Motion Matched Attenuation Correction For Dual-Gated Cardiac Single Photon Emission Computed Tomography (Spect), Christina Xing Jan 2024

Respiratory-Motion Matched Attenuation Correction For Dual-Gated Cardiac Single Photon Emission Computed Tomography (Spect), Christina Xing

Physics Theses

Cardiac and respiratory dual-gated single-photon emission computed tomography (SPECT) is a promising technique for minimizing the motion artifacts in myocardial perfusion imaging (MPI). However, attenuation correction (AC) for dual-gated SPECT using an attenuation map averaged over the respiratory cycle may lead to mismatched attenuation correction artifacts. In this study, we propose a respiratory motion-matched attenuation correction (RMM-AC) to further improve dual-gated SPECT. For each respiratory gate, RMM-AC uses an attenuation map that matches the SPECT image in a 4D reconstruction framework. Filtered backprojection reconstruction without AC (FBP-nAC) and 4D reconstruction with the attenuation map averaged over all respiratory gates (AVE-AC) …


Synthesis Of Cu-Cy Nanoparticles For Treating Pfas In Water, Ligang Wang Jan 2024

Synthesis Of Cu-Cy Nanoparticles For Treating Pfas In Water, Ligang Wang

Physics Theses

This work aims to address the cumulative harm caused by perfluoroalkyl and polyfluoroalkyl substances (PFAS) in water to human health and the ecological environment around the world. Reducing or removing PFAS pollution is an urgent need. Cu-Cy nanoparticles are photosensitizers, which were developed for photodynamic therapy of cancer in the first place. In this work, we use Cu-Cy for the catalytic degradation of PFAS. Synthesis of Cu-Cy nanoparticles in deionized water at 90 degrees Celsius is a low-cost and efficient method. We demonstrated the detailed process of synthesizing Cu-Cy nanoparticles. Under ultraviolet illumination, the synthesized Cu-Cy nanoparticles turned yellow as …