Digital Commons Network^™

Extended Search For Supernovalike Neutrinos In Nova Coincident With Ligo/Virgo Detections, M. A. Acero, P. Adamson, L. Aliaga, N. Anfimov, A. Antoshkin, E. Arrieta-Diaz, L. Asquith, A. Aurisano, A. Back, C. Backhouse, M. Baird, N. Balashov, P. Baldi, B. A. Bambah, S. Bashar, K. Bays, R. Bernstein, V. Bhatnagar, B. Bhuyan, J. Bian, Roberto Petti, Et. Al.

Faculty Publications

A search is performed for supernovalike neutrino interactions coincident with 76 gravitational wave events detected by the LIGO/Virgo Collaboration. For 40 of these events, full readout of the time around the gravitational wave is available from the NOvA Far Detector. For these events, we set limits on the fluence of the sum of all neutrino flavors of F < 7(4) × 10¹⁰ cm⁻² at 90% C.L. assuming energy and time distributions corresponding to the Garching supernova models with masses 9.6ð27Þ M_^⊙. Under the hypothesis that any given gravitational wave event was caused by a supernova, this corresponds to a distance …

Community Detection In Complex Networks, Zhenqi Lu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Network science plays a central role in understanding and modeling complex systems in many disciplines, including physics, sociology, biology, computer science, economics, politics, and neuroscience. By studying networks, we can gain a deep understanding of the behavior of the systems they represent. Many networks exhibit community structure, i.e., they have clusters of nodes that are locally densely interconnected. These communities manifest the hierarchical organization of the objects in systems, and detecting communities greatly facilitates the study of the organization and structure of complex systems.

Most existing community-detection methods consider low-order connection patterns, at the level of individual links. But high-order …

Electronic, Optical, And Magnetic Properties Of Novel Two-Dimensional Materials, Xiaobo Lu

Arts & Sciences Graduate Student Theses and Dissertations

The field of two-dimensional(2D) materials is experiencing rapid growth and attracting tremendous research interests within the condensed matter community due to its ultimate thickness dimension and unique physical properties. The consistently emerging novel 2D materials not only provide extraordinary intrinsic properties of their single layer and multi- layer structures but also exhibit fascinating responses to the tunable external conditions. The fertile contents and boundless possibilities of novel 2D materials make it one of the pivots of modern nanotechnology towards deepening the physics understanding and promising practical applications.In the first part of the thesis, we reveal the distinct Stark effects of …

Thermal Properties Of 18f-Fdg Uptake And Imaging In Positron Emission Tomography Scans Of Cancerous Cells, Carleigh R. Eagle

PANDION: The Osprey Journal of Research and Ideas

Positron Emission Tomography (PET) scans can utilize a radioactive tracer, in this case 2-deoxy2-[fluorine-18] fluoro-D-glucose (¹⁸F-FDG), to visualize malignant tumors in cancer patients. The uptake was compared to glucose to understand the difference in thermal properties, which contribute to the ability to image the cancerous cells. The uptake of ¹⁸F-FDG by cancer cells and the imaging process of positron emission tomography were reviewed from a thermodynamic perspective. Gastrointestinal and neurological imaging techniques were reviewed to understand the role of PET imaging in different areas of the human body.

Wallaby Pre-Pilot Survey: H I Content Of The Eridanus Supergroup, B. Q. For, J. Wang, Tobias Westmeier, O. I. Wong, C. Murugeshan, L. Staveley-Smith, H. M. Courtois, D. Pomarede, Juan P. Madrid

Physics & Astronomy Faculty Publications

We present observations of the Eridanus supergroup obtained with the Australian Square Kilometre Array Pathfinder (ASKAP) as part of the pre-pilot survey for the Widefield ASKAP L-band Legacy All-sky Blind Survey (WALLABY). The total number of detected H I sources is 55, of which 12 are background galaxies not associated with the Eridanus supergroup. Two massive H I clouds are identified and large H I debris fields are seen in the NGC 1359 interacting galaxy pair, and the face-on spiral galaxy NGC 1385. We describe the data products from the source finding algorithm and present the basic parameters. The …

High Sensitivity Multi-Axes Rotation Sensing Using Large Momentum Transfer Point Source Atom Interferometry, Jinyang Li, Gregório R. M. Da Silva, Wayne Cheng-Wei Huang, Mohamed Fouda, Jason Bonacum, Timothy L. Kovachy, Selim M. Shahriar

Department of Physics and Astronomy: Faculty Publications

A point source interferometer (PSI) is a device where atoms are split and recombined by applying a temporal sequence of Raman pulses during the expansion of a cloud of cold atoms behaving approximately as a point source. The PSI can work as a sensitive multi-axes gyroscope that can automatically filter out the signal from accelerations. The phase shift arising from the rotations is proportional to the momentum transferred to each atom from the Raman pulses. Therefore, by increasing the momentum transfer, it should be possible to enhance the sensitivity of the PSI. Here, we investigate the degree of enhancement in …

12 C(E,E'Pn) Measurements Of Short Range Correlations In The Tensor-To-Scalar Interaction Transition Region, I. Korover, J. R. Pybus, A. Schmidt, F. Hauenstein, M. Duer, O. Hen, E. Piasetzky, L. B. Weinstein, D. W. Higinbotham, S. Adhikari, K. Adhikari, M. J. Amaryan, Giovanni Angelini, H. Atac, L. Barion, M. Battaglieri, A. Beck, I. Bedlinkskiy, Fatiha Benmokhtar, Steffen Strauch, Ralf W. Gothe, Krishna Chandra Neupane, Et. Al.

Faculty Publications

High-momentum configurations of nucleon pairs at short-distance are probed using measurements of the C-12(e, e' p) and C-12(e, e' pN) reactions (where N is either n or p), at high-Q(2) and x(B) > 1.1. The data span a missing-momentum range of 300-1000 MeV/c and are predominantly sensitive to the transition region of the strong nuclear interaction from a Tensor to Scalar interaction. The data are well reproduced by theoretical calculations using the Generalized Contact Formalism with both chiral and phenomenological nucleon-nucleon (NN) interaction models. This agreement suggests that the measured high missing-momentum protons up to 1000 MeV/c predominantly belong to short-ranged …

Identifying Geomorphological Changes Of Coastal Cliffs Through Point Cloud Registration From Uav Images, Xiangxiong Kong

Physics and Engineering Science

Cliff monitoring is essential to stakeholders for their decision-making in maintaining a healthy coastal environment. Recently, photogrammetry-based technology has shown great successes in cliff monitoring. However, many methods to date require georeferencing efforts by either measuring geographic coordinates of the ground control points (GCPs) or using global navigation satellite system (GNSS)-enabled unmanned aerial vehicles (UAVs), significantly increasing the implementation costs. In this study, we proposed an alternative cliff monitoring methodology that does not rely on any georeferencing efforts but can still yield reliable monitoring results. To this end, we treated 3D point clouds of the cliff from different periods as …

Wavelength And Power Dependence On Multilevel Behavior Of Phase Change Materials, Gary A. Sevison, Joshua A. Burrow, Haiyun Guo, Andrew M. Sarangan, Joshua R. Hendrickson, Imad Agha

Electro-Optics and Photonics Faculty Publications

We experimentally probe the multilevel response of GeTe, Ge2Sb2Te5 (GST), and 4% tungsten-doped GST (W-GST) phase change materials (PCMs) using two wavelengths of light: 1550 nm, which is useful for telecom-applications, and near-infrared 780 nm, which is a standard wavelength for many experiments in atomic and molecular physics. We find that the materials behave differently with the excitation at the different wavelengths and identify useful applications for each material and wavelength. We discuss thickness variation in the thin films used as well and comment on the interaction of the interface between the material and the substrate with regard to the …

The Foundations Of Inference And Its Application To Fundamental Physics, Nicholas Matthew Carrara

Legacy Theses & Dissertations (2009 - 2024)

This thesis concerns the foundations of inference – probability theory,entropic inference, information geometry, etc. – and its application to the Entropic Dynamics (ED) approach to Quantum Mechanics (QM) [21, 22, 41, 53, 56–61, 150–153, 165, 195, 196, 268]. The first half of this thesis, chapters 2-6, concern the development of the inference framework. We begin in chapter 2 by discussing de- ductive inference, which involves formal logic and it’s role in access- ing the truth of propositions. We eventually discover that deductive inference is incomplete, in that it can’t address situations in which we have incomplete information. This necessitates a …

A Combined Theoretical And Photoelectron Spectroscopy Study Of Al3hn- (N=1-9) Clusters, Jing Xu, Xinxing Zhang, Haopeng Wang, Lijuan Fu, Xiang Li, Andrej Grubisic, Rachel M. Harris, Bryan Eichhorn, Gerd Gantefoer, Yihong Ding, Boggavarapu Kiran, Anil K. Kandalam, Kit H. Bowen

Physics & Engineering Faculty Publications

Combined photoelectron spectroscopic experiments and computational studies have been performed on Al3Hn- (n=1-9) clusters. Three modes of hydrogen bonding to the Al-3 moiety have been observed: terminal, bridging, and capping. Among various hydrides, Al3H5- and Al3H8- clusters have highest HOMO-LUMO gap and largest electron affinity, respectively. Our studies indicate that as the number of hydrogen atoms increase the presence of AlH2 groups, representing the tetrahedral coordination of the Al atom, which in turn led to the stoichiometric ring structure.

Acoustic Parameters As Discriminators Of Wall Events In Pico Dark Matter Search Data, Lucia Volkova

University Honors Program Senior Projects

Bubble chambers are one of several detector types that particle physicists use to search for the as-yet-undetected dark matter. The PICO collaboration – formed from the merger of the similar PICASSO and COUPP experiments – runs such a bubble detector using superheated fluorocarbons (with and without iodine). Bubbles that form along chamber walls exhibit different behavior than those which nucleate in the bulk of the target liquid due to shape distortions from the wall boundary; in previous analyses when searching for dark matter, these wall events have been cut from the data to control for the differing behavior using information …

Hyperpolarizability Dispersion Measured For Carbon Disulfide Vapor, Rodrigo N. Fernandez

UNLV Theses, Dissertations, Professional Papers, and Capstones

The second hyperpolarizability (γ) of carbon disulfide (CS2) was measured by gas phase electric-field-induced second harmonic generation (ESHG), for laser wavelengths in the range of 765-1064 nm. The observed hyperpolarizability is decomposed into electronic (γ^e) and vibrational (γ^v) contributions, and the dispersion curve for γ^eis extrapolated to the static limit, with the result γ^e_0 = 12558 ± 93 atomic units. The results of this experiment agree with other recent nonlinear optical measurements and theoretical calculations.

Calculation And Optimization Of Correlation Function In Distillation Method Of Lattice Quantum Chromodynamcis, Ren-Qiang Zhang, Xiang-Yu Jiang, Jiongchi Yu, Chong Zeng, Ming Gong, Shun Xu

Research Collection School Of Computing and Information Systems

Lattice quantum chromodynamics (lattice QCD) is a theory based on quantum chromodynamics, which is widely used in strong interaction related calculations. As a research method that can give accurate and reliable theoretical results, with the improvement of computer ability, Lattice QCD is playing an increasingly important role in recent years. Distillation method is an important numerical method to calculate hadron correlation function in lattice QCD, and can improve the signal-to-noise ratio of calculated physical quantities. Distillation is a method to approximately compute full propagator via replace the laplacian operator with it's outerproduct of laplace eigenvectors. In this way, the construction …

Localized Bands And Their Effects In The Strongly Correlated D And F Electron Systems: A First Principles Study, Hori Pada Sarker

Physics Dissertations - Archive

Strongly correlated materials such as d and f-electron systems manifest a broad range of interesting phenomena such as metal-insulator transition, high temperature superconductivity, topologically insulating behavior etc. Due to the highly localized nature of d and f-electrons, they are tightly bound about the associated atoms within the crystal lattice and hence strongly interact with intra-site electrons and the corresponding ionic cores. Such a strong localization of electrons results in the creation of polaron quasi-particles in strongly correlated system like BiVO4, a promising photoanode material for photoelectrochemical (PEC) water splitting for H2 fuel generation using solar irradiation. Using first principles density …

Quantitative Magnetic Resonance Imaging For The Early Prediction Of Treatment Response In Triple Negative Breast Cancer, Benjamin C. Musall

Dissertations and Theses (Open Access)

Triple Negative Breast Cancer (TNBC) is an aggressive subtype of breast cancer which lacks upregulated hormone receptors. Because of this, it is not vulnerable to clinically available targeted therapies. When treated with standard of care neoadjuvant systemic therapy (NAST), TNBC only shows approximately a 40% rate of pathologic complete response (pCR). A biomarker which could predict TNBC response to NAST early during treatment would be useful, as it would allow for non-responders to be triaged to alternative therapies and potentially allow for the treatment of responders to be de-escalated.

Quantitative Magnetic Resonance Imaging (MRI) may be used to probe and …

Advancement Of A 3d Computational Phantom And Its Age Scaling Methodologies For Retrospective Dose Reconstruction Studies, Aashish Gupta

Dissertations and Theses (Open Access)

We have used a 3D age-scalable computational phantom for over two decades for retrospective dose reconstruction studies of childhood cancer survivors (CCS) treated with 2D historic radiotherapy (RT). However, our phantom and its age scaling functions (ASF) must be updated so that it can be used in studies that include survivors treated with contemporary RT. We aimed to implement our phantom and its age scaling functions in DICOM format and determine the feasibility of applying our ASFs to accurately scale the whole-body CT-based anatomies.

In the implementation study, we developed Python scripts that model the phantom and ASFs in a …

Beam Formation And Vernier Steering Off Of A Rough Surface, Eric K. Nagamine, Kenneth W. Burgi, Samuel D. Butler

Faculty Publications

Wavefront shaping can refocus light after it reflects from an optically rough surface. One proposed use case of this effect is in indirect imaging; if any rough surface could be turned into an illumination source, objects out of the direct line of sight could be illuminated. In this paper, we demonstrate the superior performance of a genetic algorithm compared to other iterative feedback-based wavefront shaping algorithms in achieving reflective inverse diffusion for a focal plane system. Next, the ability to control the pointing direction of the refocused beam with high precision over a narrow angular range is demonstrated, though the …

Study Of Weakly Bound Cluster Anions Using Self Interaction Corrected Density Functional Scheme, Peter Obinna Ufondu

Open Access Theses & Dissertations

The Kohn–Sham formulation of density functional theory (DFT) is a widely used quantum mechanical theory to study chemical and materials properties. The practical application of DFT requires an approximation to the exchange–correlation (XC) functional. These approximations suffer from self-interaction errors due to the incomplete cancellation of the self-Coulomb energy with the approximate self-exchange and correlation energy for one-electron densities. Systems with weakly-bound electrons impose great challenges to semi-local density functional approximations. We use recently developed local scaled self-interaction correction (LSIC) by Zope et al and the Perdew-Zunger SIC method using the Fermi-Löwdin orbitals to calculate the vertical detachment energies (VDEs) …

Voltage-Controlled Magnetization In Chromia-Based Magnetic Heterostructures, William Echtenkamp

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Spintronics promises a new generation of low-power, high-speed, non-volatile memory and logic devices. Heterostructures based on magnetoelectric chromia enable the direct manipulation of magnetization by applied electric fields and emerged as a promising building block for spintronic devices. In this dissertation, several interesting emergent magnetic properties arising in these device-enabling building blocks are examined. In some cases, exchange coupling at the interface between the magnetoelectric antiferromagnet and an adjacent ferromagnet stabilizes the interfacial antiferromagnetic domain state against the electrically induced rotation of the bulk spin structure. Upon magnetically cycling the ferromagnet, the magnetoelectric antiferromagnet relaxes towards a commensurate spin structure …

Modeling Of Argon Bombardment And Densification Of Low Temperature Organic Precursors Using Reactive Md Simulations And Machine Learning, Kwabena Asante-Boahen

Graduate Theses/Dissertations

In this study, an important aspect of the synthesis process for a-BxC:Hy was systematically modeled by utilizing the Reactive Molecular Dynamics (MD) in modeling the argon bombardment from the orthocarborane molecules as the precursor. The MD simulations are used to assess the dynamics associated with the free radicals that result from the ion bombardment. By applying the Data Mining/Machine Learning analysis into the datasets generated from the large reactive MD simulations, I was able to identify and quality the kinetics of these radicals. Overall, this approach allows for a better understanding of the overall mechanism at the atomistic level of …

Seasonal Variation Of Multiple-Muon Cosmic Ray Air Showers Observed In The Nova Detector Detector On The Surface, M. A. Acero, P. Adamson, L. Aliaga, N. Anfimov, A. Antoshkin, E. Arrieta-Diaz, L. Asquith, A. Aurisano, A. Back, C. Backhouse, M. Baird, N. Balashov, P. Baldi, B. A. Bambah, S. Bashar, K. Bays, R. Bernstein, V. Bhatnagar, B. Bhuyan, J. Bian, Roberto Petti, Et. Al.

Faculty Publications

We report the rate of cosmic ray air showers with multiplicities exceeding 15 muon tracks recorded in the NOvA Far Detector between May 2016 and May 2018. The detector is located on the surface under an overburden of 3.6 meters water equivalent. We observe a seasonal dependence in the rate of multiple-muon showers, which varies in magnitude with multiplicity and zenith angle. During this period, the effective atmospheric temperature and surface pressure ranged between 210 K and 230 K and 940 mbar and 990 mbar, respectively; the shower rates are anticorrelated with the variation in the effective temperature. The variations …

X Radiation Dose Monitoring For Adolescent And Adult Patients In Selected Health Care Environment Related Places, Kevin Riandi

Journal of Environmental Science and Sustainable Development

A study on patient absorption dose according to age group was carried out. The amount of absorbed A study on patient absorption dose according to age group was carried out. The amount of absorbed dose of X-ray radiation affect the body cells. Health care hospitals such as clinics, environments that use ionizing radiation. Based on the procedure for using ionizing radiation for medical purposes, the Indonesian Nuclear Energy Supervisory Agency recommends monitoring radiation doses for health workers on health service environment. Likewise with the patient, because the patient is directly exposed to the ionizing radiation. Some researh explained that the …

Detecting Optical Transients Using Artificial Neural Networks And Reference Images From Different Surveys, Katarzyna Wardęga, Adam Zadrozny, Martin Beroiz, Richard S. Camuccio, Mario C. Diaz

Physics & Astronomy Faculty Publications

We present a technique to detect optical transients based on an artificial neural networks method. We describe the architecture of two networks capable of comparing images of the same part of the sky taken by different telescopes. One image corresponds to the epoch in which a potential transient could exist; the other is a reference image of an earlier epoch. We use data obtained by the Dr. Cristina V. Torres Memorial Astronomical Observatory and archival reference images from the Sloan Digital Sky Survey. We trained a convolutional neural network and a dense layer network on simulated source samples and then …

Computational Studies Of Carbon Nanocluster Solidification, Chathuri C. Silva

Dissertations

A subset of micron-size meteoritic carbon particles formed in red giant atmospheres show a core-rim structure, likely condensed from a vapor phase into super-cooled carbon droplets that nucleated graphene sheets (~40Å) on randomly oriented 5-atom loops during solidification, followed by coating with a graphite rim. Similar particles form during slow cooling of carbon vapor in the lab.

Here we investigate the nucleation and growth of carbon rings and graphene sheets using density functional theory (DFT). Our objectives: (1). explore different computational techniques in DFT-VASP for various carbon structures and compare the results with literature, (2). investigate the nucleation and growth …

54fe(D,P)55fe Single Neutron Transfer, Matthew Quirin, Raymond Saunders

Physics and Astronomy Summer Fellows

During our summer research at the John D Fox Laboratory, we used the 9 MV Tandem van de Graaff accelerator and the Super Enge Split-Pole Spectrograph to make measurements of the neutron transfer reaction 54Fe(d,p) 55Fe to observe and explore excited states of 55Fe and shell structure beyond the magic number N=28. We have created momentum spectra and angular distribution plots of the protons from the reaction which will be analyzed to determine the angular momentum values of states and single-neutron energies in 55Fe in an effort to better understand nuclear structure.

Bridging The 12-6-4 Model And The Fluctuating Charge Model, Pengfei Li

Chemistry: Faculty Publications and Other Works

Metal ions play important roles in various biological systems. Molecular dynamics (MD) using classical force field has become a popular research tool to study biological systems at the atomic level. However, meaningful MD simulations require reliable models and parameters. Previously we showed that the 12-6 Lennard-Jones nonbonded model for ions could not reproduce the experimental hydration free energy (HFE) and ion-oxygen distance (IOD) values simultaneously when ion has a charge of +2 or higher. We discussed that this deficiency arises from the overlook of the ion-induced dipole interaction in the 12-6 model, and this term is proportional to 1/r …

Eccentricity Of Merging Neutron Star Binaries: Searches, Parameter Estimation, And Future Prospects, Amber Kiana Lenon

Dissertations - ALL

Since the start of the first observing run the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Advanced Virgo observatory have detected 48 binary black hole mergers and two binary neutron star mergers. Knowledge about the properties of the binary can be gained from the gravitational-wave observations. Binary neutron star systems can form with significant orbital eccentricity. Gravitational radiation efficiently removes this eccentricity from the binary's orbit as the star's inspiral together. This thesis describes a search for neutron star binaries that have an eccentric orbits when their gravitational waves enter the sensitive band of Advanced LIGO and Virgo. For …

Python Routines For Low Temperature Resistive Thermometry In Magnetic Fields, Nathanael Fortune, Scott T. Hannahs, Julia Frothingham

Physics: Faculty Publications

No abstract provided.

Synoptic Conditions And Potential Causes Of The Extreme Heavy Rainfall Event Of January 2009 Over Mindanao Island, Philippines, Lyndon Mark P. Olaguera, Michelle Español Caballar, Joseph Cabacungan De Mata, Loida Ann Torres Dagami, Jun Matsumoto, Hisayuki Kubota

Physics Faculty Publications

This study investigates the synoptic conditions that led to the heavy rainfall/flood (HRF) event in Mindanao Island, Philippines (122 −127°E; 5 −10°N), on January 2009 (JAN2009 HRF) that are less emphasized in previous works. Extensive flooding was reported over Cagayan de Oro City in the northern part of Mindanao, where the rainfall on January 10, 11, and 13, 2009, exceeded the 99th percentile of daily rainfall records of all January of the city from 1979 to 2017 by almost two times. A similar exceedance was also felt in Hinatuan station over the eastern coast of Mindanao Island on January 15, …