Physical Sciences and Mathematics Commons^™

Delay Dynamic Equations On Isolated Time Scales And The Relevance Of One-Periodic Coefficients, Martin Bohner, Tom Cuchta, Sabrina Streipert

Mathematics and Statistics Faculty Research & Creative Works

We are motivated by the idea that certain properties of delay differential and difference equations with constant coefficients arise as a consequence of their one-periodic nature. We apply the recently introduced definition of periodicity for arbitrary isolated time scales to linear delay dynamic equations and a class of nonlinear delay dynamic equations. Utilizing a derived identity of higher order delta derivatives and delay terms, we rewrite the considered linear and nonlinear delayed dynamic equations with one-periodic coefficients as a linear autonomous dynamic system with constant matrix. As the simplification of a constant matrix is only obtained for one-periodic coefficients, dynamic …

Streamlined Subglacial Bedform Sensitivity To Bed Characteristics Across The Deglaciated Northern Hemisphere, Marion A. Mckenzie, Lauren M. Simkins, Sarah M. Principato, Santiago Munevar Garcia

Environmental Studies Faculty Publications

Streamlined subglacial bedforms observed in deglaciated landscapes provide the opportunity to assess the sensitivity of glacier dynamics to bed characteristics across broader spatiotemporal scales than is possible for contemporary glacial systems. While many studies of streamlined subglacial bedforms rely on manual mapping and qualitative (i.e., visual) assessment, we semi-automatically identify 11,628 sedimentary and bedrock bedforms, created during and following the Last Glacial Maximum across nine geologically and topographically diverse deglaciated sites in the Northern Hemisphere. Using this large dataset of landforms and associated morphometrics, we empirically test the importance of subglacial terrain on bedform morphology and ice-flow behavior. A minimum …

Reducing Leakage Current And Enhancing Polarization In Multiferroic 3d Supernanocomposites By Microstructure Engineering, Erik Enriquez, Ping Lu, Leigang Li, Bruce Zhang, Haiyan Wang, Quanxi Jia, Aiping Chen

Computer Science Faculty Publications and Presentations

Multiferroic materials have generated great interest due to their potential as functional device materials. Nanocomposites have been increasingly used to design and generate new functionalities by pairing dissimilar ferroic materials, though the combination often introduces new complexity and challenges unforeseeable in single-phase counterparts. The recently developed approaches to fabricate 3D super-nanocomposites (3D‐sNC) open new avenues to control and enhance functional properties. In this work, we develop a new 3D‐sNC with CoFe2O4 (CFO) short nanopillar arrays embedded in BaTiO3 (BTO) film matrix via microstructure engineering by alternatively depositing BTO:CFO vertically-aligned nanocomposite layers and single-phase BTO layers. This microstructure engineering method allows …

Fiesta And Shock-Driven Flows, Brian E. Romero

Mechanical Engineering ETDs

In this study, the interaction of a shock with various gas and particle interfaces is analyzed through simulations using a new, GPU capable, multi-species flow solver, FIESTA (Fast, Interface Evolution, Shocks, and Transport in the Atmosphere), de- veloped for this research. The cases studied include the interaction between a shock and i) a two-dimensional (2D), circular cloud of a dense gas; ii) a 2D curtain of a dense gas; iii) a three-dimensional (3D) cylinder of a dense gas, and iv) a 3D curtain of solid particles.

In simulations of a 2D gas curtain and a 3D gas column, the curtain …

Data Supporting: Scaling Of Turbulence And Microphysics In A Convection-Cloud Chamber Of Varying Height, Subin Thomas, Fan Yang, Mikhail Ovchinnikov, Will Cantrell, Raymond Shaw

Michigan Tech Research Data

The file contains the data corresponding to the figures in the paper. Abstract for the paper: The convection-cloud chamber enables measurement of aerosol and cloud microphysics, as well as their interactions, within a turbulent environment under steady-state conditions. Increasing the size of a convection-cloud chamber, while holding the imposed temperature difference constant, leads to increased Rayleigh, Reynolds and Nusselt numbers. Large-eddy simulation coupled with a bin microphysics model allows the influence of increased velocity, time, and spatial scales on cloud microphysical properties to be explored. Simulations of a convection--cloud chamber, with fixed aspect ratio and increasing heights of H=1, 2, …

Covertness And Timeliness Of Data Collection In Uav-Aided Wireless-Powered Iot, Xingbo Lu, Weiwei Yang, Shihao Yan, Zan Li, Derrick Wing Kwan Ng

Research outputs 2014 to 2021

In this work, we aim to maximize the timeliness of data collection subject to a covertness constraint in unmanned aerial vehicle (UAV)-aided Internet-of-Things (IoT) networks, where a UAV periodically conducts wireless power transfer (WPT) to charge an energy-constrained IoT device and then the IoT device opportunistically sends its collected data to the UAV. To this end, we first derive a lower bound on the covertness constraint and an analytical expression for age of information (AoI) to characterize timeliness. Then, we jointly optimize the UAV’s transmit power for WPT, the WPT duration, and the data transmission duration by considering two practical …

Reducing Leakage Current And Enhancing Polarization In Multiferroic 3d Super-Nanocomposites By Microstructure Engineering, Erik Enriquez, Ping Lu, Leigang Li, Bruce Zhang, Haiyan Wang, Quanxi Jia, Aiping Chen

Physics and Astronomy Faculty Publications and Presentations

Multiferroic materials have generated great interest due to their potential as functional device materials. Nanocomposites have been increasingly used to design and generate new functionalities by pairing dissimilar ferroic materials, though the combination often introduces new complexity and challenges unforeseeable in single-phase counterparts. The recently developed approaches to fabricate 3D super-nanocomposites (3D‐sNC) open new avenues to control and enhance functional properties. In this work, we develop a new 3D‐sNC with CoFe2O4 (CFO) short nanopillar arrays embedded in BaTiO3 (BTO) film matrix via microstructure engineering by alternatively depositing BTO:CFO vertically-aligned nanocomposite layers and single-phase BTO layers. This microstructure engineering method allows …

Functional Morphology And Taphonomy Of Ordovician–Silurian Diploporan Echinoderms, Stephen Ashley Hill

USF Tampa Graduate Theses and Dissertations

Diploporan echinoderms were one of the most speciose groups of stemmed echinoderms during the Ordovician. Despite this widespread abundance, the fossil record of diploporan fauna consists primarily of incomplete specimens, with complete specimens being rare. While the theca, or body, is more commonly preserved, the feeding appendages and the attachment structures (i.e. stems or holdfasts) are seldomly preserved. Insight into these features is highly valuable to the understanding the paleoecology, like the feeding and respiratory strategies, of these enigmatic creatures.

One group of diploporan echinoderms which does have an extensive fossil record, is the Holocystites Fauna, primarily known from the …

Disaster Resilience Versus Ecological Resilience And The Proposed Second Causeway To South Padre Island, Juliet Vallejo, Katia Sanchez, Evelyn Roozee, Owen Temby

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

The barrier island of South Padre is located off the coast of Texas’s southern tip in Cameron County and is a popular tourist destination with over 4 million annual visits. The only road access to and from the island is a four-lane causeway, 2.3 miles in length, that routinely experiences heavy traffic. Twenty years ago, a barge crashed into the Queen Isabella Causeway, destroying a portion of the bridge. It quickly became apparent how reliant South Padre Island (SPI) is on the causeway and raised questions regarding its lack of disaster resilience. Local boosters and government responded by proposing and …

A Method For Estimating Songbird Abundance With Drones, Andrew M. Wilson, Darren Glass, Marisa A. Immordino, Precious S. Ozoh, Lauren Sherman, Mckenzie D. Somers

Environmental Studies Faculty Publications

Using drones to conduct airborne bioacoustics surveys is a potentially useful new way to estimate the abundance of vocal bird species. Here we show that by using two audio recorders suspended from a quadcopter drone it is possible to estimate distances to birds with precision. In an experimental test, the mean error of our estimated distances to a broadcast song across 11 points between 0 and 100 m away was just 3.47 m. In field tests, we compared 1 min airborne counts with 5 min terrestrial counts at 34 count locations. We found that the airborne counts yielded similar data …

Drivers Of Spatiotemporal Eukaryote Plankton Distribution In A Trans-Basin Water Transfer Canal In China, Yuying Li, Faisal Hayat Khan, Jiamin Wu, Yun Zhang, Yeqing Jiang, Xiaonuo Chen, Yinlei Yao, Yangdong Pan, Xuemei Han

Environmental Science and Management Faculty Publications and Presentations

Planktonic eukaryotes are important components of aquatic ecosystems, and analyses of the whole eukaryotic planktonic community composition and function have far-reaching significance for water resource management. We aimed to understand the spatiotemporal variation and drivers of eukaryotic plankton distribution in the Middle Route Project of the South-to-North Water Diversion in Henan Province, China. Specifically, we examined planktonic assemblages and water quality at five stations along the canal and another one located before the dam in March, June, September, and December 2019. High-throughput sequencing revealed that the eukaryotic plankton community was primarily composed of 53 phyla, 200 genera, and 277 species, …

Coupling 210Pb And 14C To Constrain Carbon Burial Efficiency Of Blue Carbon Ecosystems, Tynisha R. Martin

USF Tampa Graduate Theses and Dissertations

Blue carbon ecosystems cover a small global area but have the potential to sequester large amounts of organic carbon (OC) from the coastal ocean in the sediment. Organic carbon is continually remineralized and exported in the dissolved form, which is currently only poorly accounted for in blue carbon budgets. Constraining carbon cycling in blue carbon systems is complicated by the range of carbon sources and sinks in the system and high export rates from the system. By coupling 14C and 210Pb chronometers to ascertain the amount of primary production stored within peat, it is possible to study carbon transport through …

Nmr Analyses Of Flavored E-Cigarette Liquids Before And After Aerosolization, Paul Joseph Kerber

Dissertations and Theses

Electronic cigarettes (e-cigarettes) are the most commonly used tobacco products among adolescents with ~11 and ~3% of high school and middle school students reporting past 30 day use in 2021 according to the Centers for Disease Control and Prevention (CDC), respectively. Furthermore, greater than ~80% of high school and middle school e-cigarette consumers use flavored e-liquids. Consumers can be exposed to variable toxicant levels upon e-liquid aerosolization, depending on the composition of the e-liquid, type of e-cigarette, e-cigarette settings, and other customizations.

E-liquids are typically composed of a carrier solvent (propylene glycol (PG) and glycerol (GL)), flavorants, and nicotine. PG …

Effect Of Phylogeny Misestimation On Estimating Trait Evolution Parameters, Tabytha Ariel Perez

Mathematics & Statistics ETDs

Biologists are interested in estimating trait evolution models from phylogenies. However, phylogenies are imperfectly estimated, generally from DNA sequence data. In this study, true phylogenies are simulated to understand whether errors in phylogeny estimation affect inference of the trait evolution model. Given the tree, DNA sequences as well as traits are then simulated from the true phylogeny; both are simulated independently from the other. After the simulation, the DNA sequences were used to estimate trees using the UPGMA method without utilizing the trait information. The estimated trees combined with the traits are used to infer the evolutionary trait models, specifically …

Wildfire Risk In Mountain West States, 2017-2021, Olivia K. Cheche, Corryn Richardson, Zachary Billot, Miguel Soriano Ralston, Vanessa Booth, Caitlin J. Saladino, William E. Brown Jr.

Environment

This fact sheet examines data on wildfire destruction in the Mountain West states of Arizona, Colorado, Nevada, New Mexico, and Utah. The original report from the Insurance Information Institute presents findings on percent of properties at risk of wildfire destruction, the number of wildfires by state, and numbers of acres burned per state.

Negative Photoresponse In Ti3C2TX Mxene Monolayers, Nataliia S. Vorobeva, Saman Bagheri, Angel Torres, Alexander Sinitskii

Chemistry Department: Faculty Publications

Two-dimensional transition metal carbides, nitrides, and carbonitrides, collectively known as MXenes, are finding numerous applications in many different areas, including optoelectronics and photonics, but there is limited information about their intrinsic photoresponse. In this study, we investigated the visible and near-infrared range photoresponse of Ti₃C₂T_x, the most popular MXene material to date. The electrical measurements were performed on devices based on individual monolayer Ti₃C₂T_x MXene flakes, which were characterized by a variety of microscopic and spectroscopic methods. For MXene devices with different electrode layouts, the current reproducibly decreased under …

Human-Centered Avalanche Susceptibility Mapping, Lindsey L. Rotche

Geography ETDs

With backcountry winter travel increasing in popularity, the importance of accessible avalanche safety information is crucial. Widely accessible avalanche backcountry maps use slope shading to show where avalanches are likely to start. Instead of focusing on the hazard of an avalanche starting in a specific location, this project shifted the cartographic emphasis of avalanche susceptibility maps to show risk to a human traveling in the terrain. I developed a methodology to incorporate possible avalanche runouts, terrain traps, and connected slopes while reducing false certainty of the visualization. To provide a more comprehensive representation of susceptible terrain, I integrated aspect, distance …

Inland Tropical Cyclone Intensity Decay In The Continental United States, Yijie Zhu

USF Tampa Graduate Theses and Dissertations

Tropical cyclone (TC) hazard preparation is mostly focused on coastal cities with less attention typically paid to inland regions. The impact of TCs that propagate far inland is often underestimated and can cause unexpected loss of life and economic loss. This dissertation aims to understand the decay process of TCs during the post-landfall stage by answering three main research questions: (1) What are the general patterns of inland tropical cyclones, including spatial variations, decay rates, and translation speeds? (2) Are there temporal changes in the intensity decay from inland moving hurricanes? (3) How is the hurricane post-landfall dissipation related to …

Butte Priority Soils Operable Unit (Bpsou) Draft Final Insufficiently Reclaimed Sites - Field Sampling Plan (Fsp) Bres No. 133 – Dexter Mill, Mike Mcanulty

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

The Impact Of Extreme Weather On Student Online Learning Participation, Ezekiel Adriel D. Lagmay, Maria Mercedes T. Rodrigo

Department of Information Systems & Computer Science Faculty Publications

In March 2020, the COVID-19 pandemic forced over 1 billion learners to shift from face-to-face instruction to online learning. Seven months after it began, this transition became even more challenging for Filipino online learners. Eight typhoons struck the Philippines from October to November 2020. Two of these typhoons caused widespread flooding, utilities interruptions, property destruction, and loss of life. We examine how these severe weather conditions affected online learning participation of Filipino students pursuing their undergraduate and graduate studies. We used CausalImpact analysis to explore September 2020 to January 2021 data collected from the Moodle Learning Management System data of …

Quantifying Protein Quality To Understand Protein Homeostasis, Hsien-Jung Lavender Lin

Theses and Dissertations

Proteins are the center of all biochemical reactions in living organisms. Proteins need to be present at the right time, in the right place, with the correct concentration and have the right shape to carry their designated function. Protein homeostasis is when all proteins in the proteome are in functional balance, and such balance is maintained by synthesis, folding, and degradation machinery. When protein homeostasis is lost, organisms start to age and develop diseases. To truly unveil disease mechanisms and provide more efficient means for treatment and prevention, we need a holistic understanding of the mechanism of protein homeostasis. Currently, …

Cybersecurity Educational Resources For K-12, Debra Bowen, James Jaurez, Nancy Jones, William Reid, Christopher Simpson

Journal of Cybersecurity Education, Research and Practice

There are many resources to guide successful K-12 cybersecurity education. The objective of these resources is to prepare skilled and ethical cybersecurity students at the earliest level to meet the demands of higher-level programs. The goal of this article is to provide, as a starting point, a list of as many currently popular K-12 educational resources as possible. The resources provided are broken into five categories: 1) Career Information, 2) Curriculum, 3) Competitions, 4) CyberCamps, and 5) Labs and Gaming. Each resource listed has a link, the K-12 levels that are supported, whether the resource is free or has a …

Digital Contact Tracing And Privacy, Mahdi Nasereddin, Edward J. Glantz, Galen A. Grimes, Joanne Peca, Michelle Gordon, Mike Bartolacci

Journal of Cybersecurity Education, Research and Practice

Digital contact tracing tools were developed to decrease the spread of COVID-19 by supplementing traditional manual methods. Although these tools have great potential, they were developed rather quickly resulting in tools with varying levels of success. The main issues with these tools are over privacy and who might have access to the information gathered. In general, their effectiveness varied globally, where users expressed privacy concerns associated with sharing identity, illness, and location information. This paper reviews these issues in deployments across Asia, Europe, and the United States. The goal is to begin a discussion that improves the design and development …

Security Simulations In Undergraduate Education: A Review, Joseph Simpson, Aaron Brantly

Journal of Cybersecurity Education, Research and Practice

Several decades of research in simulation and gamification in higher education shows that simulations are highly effective in improving a range of outcomes for students including declarative knowledge and interest in the topic being taught. While there appears to be a broad array of options to provide education in an undergraduate setting related to security, no previous reviews have explored computer-based simulations covering all facets of security. Given the increasing importance and adoption of interdisciplinary educational programs, it is important to take stock of simulations as a tool to broaden the range of problems, perspectives, and solutions presented to students. …

Assessing The Practical Cybersecurity Skills Gained Through Criminal Justice Academic Programs To Benefit Security Operations Centers (Socs), Lucy Tsado, Jung Seob "Scott" Kim

Journal of Cybersecurity Education, Research and Practice

Private-sector and public-sector organizations have increasingly built specific business units for securing company assets, reputation, and lives, known as security operations centers (SOCs). Depending on the organization, these centers may also be referred to as global security operations centers, cybersecurity operations centers, fusion centers, and corporate command centers, among many other names. The concept of centralized function within an organization to improve an organization’s security posture has attracted both the government and the private sectors to either build their own SOCs or hire third-party SOC companies.

In this article, the need for a multidisciplinary approach to cybersecurity education at colleges …

Characterization Of Three-Dimensional Fractional Viscoelastic Models Through Complex Modulus Analysis And Polar Decomposition, Avradip Ghosh, Avinash Kumar Both, Chin Li Cheung

Chemistry Department: Faculty Publications

Soft materials such as gels, elastomers, and biological tissues have diverse applications in nature and technology due to their viscoelastic nature. These soft materials often exhibit complex rheology and display elastic and viscous characteristics when undergoing deformation. In recent years, fractional calculus has emerged as a promising tool to explain the viscoelastic behavior of soft materials. Scalar constants are primarily used to quantify viscoelastic elements such as springs and dashpots. However, in three-dimensional (3D) space, not all materials show the same elastic or viscoelastic properties in all directions, especially under elastic/viscoelastic wave propagation (or anisotropy). Though previously reported studies on …

Summing Hecke Eigenvalues Over Polynomials, Liubomir Chiriac, Liyang Yang

Mathematics and Statistics Faculty Publications and Presentations

In this paper we estimate sums of the form ∑n≤X|aSymmπ(|f(n)|)|, for symmetric power lifts of automorphic representations π attached to holomorphic forms and polynomials f(x)∈Z[x] of arbitrary degree. We give new upper bounds for these sums under certain natural assumptions on f. Our results are unconditional when deg(f)≤4. Moreover, we study the analogous sum over polynomials in several variables. We obtain an estimate for all cubic polynomials in two variables that define elliptic curves.

Single-Crystal Elasticity Of Clinopyroxenes And The Viscosity Of Kimberlite Magma Under High Pressure-Temperature Conditions, Ming Hao

Earth and Planetary Sciences ETDs

Clinopyroxene is not only an important mineral phase in the pyrolitic upper mantle, but also one of the dominated mineral phases in the subducted or delaminated eclogitic materials in the deep Earth. Identifying and locating these eclogitic materials requires the knowledge of the thermoelastic properties of clinopyroxene under high pressure-temperature conditions. In this dissertation, we have measured the single-crystal elastic properties of jadeite and omphacite, which are major clinopyroxene phases in the eclogitic materials, up to 18 GPa 700 K by Brillouin spectroscopy and utilized these data to identify the eclogitic heterogeneities in the mantle.

We also measured the viscosity …

Halogen And Non-Traditional Isotope Geochemistry Of Planetary And Terrestrial Materials, Anthony Gargano, Zachary Sharp, Justin Simon, Charles Shearer, Adrian Brearley, James Day

Earth and Planetary Sciences ETDs

This dissertation presents the advances in non-traditional isotope geochemistry of planetary and terrestrial materials encompassing chlorine, sulfur, and zinc isotopes, as well as halogen geochemistry. A wide breadth of materials was studied throughout the completion of this work including iron meteorites, achondrites, chondrites, Apollo lunar samples, as well ancient marine chert, and carbonate sediments. Much of the focus involved the development of a method capable of simultaneously measuring the halogen contents and chlorine isotope compositions of geological materials. Here, I present these data sets to broadly characterize the process of devolatilization of planetary materials, and specifically the problem of ‘halogen-poisoning’ …

Search For Flavor-Changing Neutral Current Interactions Of The Top Quark And Higgs Boson In Final States With Two Photons In Proton-Proton Collisions At √S =13 Tev, A. Tumasyan

Department of Physics and Astronomy: Faculty Publications

Proton-proton interactions resulting in final states with two photons are studied in a search for the signature of flavor-changing neutral current interactions of top quarks (t) and Higgs bosons (H). The analysis is based on data collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, corresponding to an integrated luminosity of 137 fb⁻¹. No significant excess above the background prediction is observed. Upper limits on the branching fractions (Ɓ) of the top quark decaying to a Higgs boson and an up (u) or charm …