Physical Sciences and Mathematics Commons^™

Understanding The Spin-Glass State Through The Magnetic & Electronic Properties Of Mn-Doped Znte, A. Alcantara, S. Barrett, D. Matev, I. Miotkowski, A. K. Ramdas, T. Pekarak, J. T. Haraldsen

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Project of Merit Winner

International Research Symposium Exhibitor and Honorable Mention

To gain insight into the spin-glass state of diluted magnetic semiconductors, we have examined the magnetic and electronic properties of Mn-doped ZnTe using density functional theory. Using a generalized gradient approximation, we investigate the electronic and magnetic properties for x=0, 0.25, and 0.50 doping levels using the magnetic moment of Mn2+ as guide for the dependence of the Hubbard onsite potential on the electronic structure as well as a geometry optimization to assure an anti-ferromagnetic (AFM) ground state which is consistent with a zero magnetic moment spin glass state. …

Opioid Epidemic On The First Coast​, Jeremiah Baclig, Noah Dedeo, Rukhaiya Husain, Iliya Kulbaka, Michelle Dedeo

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Project of Merit Winner

The nation has been focusing on the opioid epidemic for many years. Aggregate quarterly data on opioid distribution at a general level has been available through the Drug Enforcement Administration (DEA) but cannot be used to do analyses on the effects of opioids in local areas. Quantifying impacts of the opioid epidemic at the local level has never been easy: what little data was provided by the DEA was not user-friendly, overly broad and did not follow the desired timeline of data collection. This project focuses on database exploration and uses statistical methods and Decision Tree …

Gamma Rays From Massive Star Clusters G25 & G27, Abagael Barba, John W. Hewitt

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Project of Merit Winner

Cosmic rays have baffled astronomers for over a century, as all potential origins have yet to be determined. Most of these galactic accelerated atomic nuclei are thought to be created in two possible fashions: from a supernova, or within a massive star cluster (MSC). In this study, we analyzed gamma-ray emission coincident with two MSCs named G25 and G27. Using NASA’s Fermi Large Area Telescope (LAT), we confirmed that the sources of gamma rays are spatially extended and emit up to the maximum energies observed by the LAT. So far, only the closest MSC to Earth …

Monitoring The Night Sky For Iceact, Andre Sierra Alderete, John W. Hewitt, Warren Huelsnitz

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

The neutral subatomic neutrinos are astronomical messengers that can provide us information to investigate the most violent astrophysical sources: supernovas, gamma-ray bursts, and cataclysmic phenomena involving black holes and neutron stars. As these astrophysical neutrinos freely travel from their point of origin without being scattered by interstellar magnetic fields, we can analyze these particles by observing cosmic-ray air showers on the Earth’s atmosphere. These are produced by the energetic neutrinos by interacting with the air particles that produce a wavefront of Cherenkov radiation. To better identify these background neutrinos, IceCube, the South Pole Neutrino Observatory, constructed an imaging air Cherenkov …

Propagation, Upkeep, And Impact On Mental Health And Classroom/Workplace Success Of Dracaena Trifasciata, Chlorophytum Comosum, And Philodendron Hederaceum, Ivan Korostenskij

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Honorable Mention Winner

Environmental Center Leadership Program Project

Greenery and plant life has been shown to increase quality of life and overall wellness in classroom and work environments (Erzsebet et al. 7; Pitts 2). Specifically, many ornamental plants have unique roles in filtering toxic chemicals from ambient air (Erzsebet et al. 3). With a recent push to increase student involvement in a greener environment, in conjunction with the University of North Florida’s Ogier Gardens, we focus here to determine and describe the most optimal plants to propagate and increase student engagement with. We chose Dracaena trifasciata, Chlorophytum comosum, and Philodendron …

Magnetic Properties Of Mbe Grown La0.6sr0.4mno3 Thin Films, R. Marquez Tavera, C. Brannan, W. A. Ruiz, C. Kemgle, J. Payne, D. Brown, M. P. Warusawithana, T. M. Pekarek

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Honorable Mention Winner

This project investigates the magnetic properties of a La1-xSrxMnO3 (x = 0.40) sample of high quality. This sample was grown one atomic layer at a time by Prof. Warusawithana using UNF’s Molecular Beam Epitaxy (MBE) machine. These magnetic properties are investigated over a range of temperatures from 5 to 400 K in fields up to 7 T. We make use of the techniques to analyze the sample to determine to a high degree of precision the critical temperature of the sample, we determined it to be 252 K. We further identified the saturated magnetization, remnant magnetization, and …

Curve Reconstruction From The Apparent Contour Graph, Nkosi Alexander-Williams

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Project of Merit Winner

This project concerns the two-dimensional Scenery Reconstruction Problem (2D-AC), a simplified version of the Scenery Reconstruction Problem (3D-AC) studied by Bellettini, Beorchia, Paolini, and Pasquarelli. In our research, we take a picture of a 2D object, take information from the picture, specifically the edges of the object as seen in the picture, and from this information, we determine if we can reconstruct the original 2D object. Utilizing knowledge of the concepts regarding contour generators and apparent contours, we determine the labelings for these points and call the labelings the Apparent Contour Graph. This project answers the …

Solving Classical Computing Problems Via Quantum Computing, David Wisnosky

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Honorable Mention Winner

The field of computing has in recent years begun to hit a wall in what is computationally feasible. In the past problems that were complex from a time standpoint waited for hardware to advance. Currently, Moore’s Law, the observation that the number of transistors on a chip doubles about every two years, has come to an end. This is due to the size of a transistor becoming so small that it begins to experience quantum effects and the laws of physics upon which a computer is built break down. A new paradigm of computing has emerged to …

Magnetic Properties Of Mbe Grown La1-Xsrxmno3 Thin Films Versus Bulk Crystal Data, Charles Bryant, James Payne, Calleigh Brannan, Rodolfo Marquez Tavera, Maitri P. Warusawithana

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

We have studied how the ferromagnetic transition and other magnetic properties vary with concentration. Data collected has been analyzed, using SigmaPlot software, to better evaluate reduced dimensionality effects on the magnetic behavior of lanthanum strontium manganite (La1-xSrxMnO3 or LSMO). Measurements using reflection high-energy electron diffraction (RHEED) were incorporated to verify that the crystals are high quality. We then measured the magnetic properties using our Superconducting Quantum Interference Device (SQUID) magnetometer. These magnetic properties have been analyzed to determine the characteristics of the superlattice. The primary goal has involved the magnetic data collection and analysis. Our analysis has investigated the major …

Oer Immersive Mulitmedia Materials Project: Vr As An Agent Of Change, Alexander Isin, Jade Basilius, Johana Barrero, Angeles Fernandez-Cifuentes

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

OER-Immersive Multimedia Materials Project: VR as an Agent of Change Alexander Isin, Computer Science/ Spanish Major (Main researcher) Jade Basilius, Communication/ Spanish Major (Main researcher) Mentors: Johana Barrero, Ph. D., Ångeles Fernández Cifuentes, Ph. D. This project aims at the design and development of immersive instructional materials (with a focus on virtual reality) for the Spanish language, literature, and culture classroom. It specifically involves the design of an interactive 360-degree experience in Spanish about the Florida Keys Coral Reefs and their environmental, socioeconomic, and cultural impact on the community. My involvement in the project focused on the research of different …

Garduino: Using Image Processing To Measure Health In Plants, Maria Pugliese, Matthew Tapia, Adam Flowers, Patrick Kreidl

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Honorable Mention Winner

As the world population increases, so do the demands for more efficient (less energy-consuming) methods of food cultivation. The vision of “precision agriculture” strives for greater farmland efficiency through advances in technology (sensors, robots), promising capabilities beyond what is possible from only manual labor. The University of North Florida’s “Garduino” project, providing a “hands-on” garden bed within which customized automated solutions can be piloted, aims to prepare engineering and computing undergraduates for this precision agriculture vision. A particularly valuable data source in this vision is near-field crop imagery, as may be acquired via self-navigating ground robots with …

Shor’S Algorithm: How Quantum Computing Affects Cybersecurity, Caroline Fedele, Asai Asaithambi

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Honorable Mention Winner

Almost all of today’s computer security relies on something known as the RSA cryptosystem. This system relies on a mathematical, specifically number theory, problem known as prime factorization, where a composite number is broken down into its two prime number factors. This in an ideal method for encryption because it is easy to multiply two numbers, encoding the data, but it much harder to determine which numbers were originally multiplied together, thus hard to decode the data. If this composite number is sufficiently large, there is no known algorithm for efficiently breaking it down – at least …

Exploring The Effects Of Various Growth Conditions On Gene Expression Of Mechanosensitive Ion Channels In Escherichia Coli, Sarah C. Johnson, Hannah R. Malcolm

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

In rapidly changing environmental conditions, bacterial mechanosensitive ion channels are responsible for ensuring cell survival. Bacterial mechanosensitive channels gate in response to membrane tension in order to relieve intracellular pressure, prior to cell lysis. The most well-studied bacterial mechanosensitive channels include the mechanosensitive channel of large (MscL) and small (MscS) conductance from Escherichia coli (E. coli), both of which gate in response to tension. In E. coli, there are seven mechanosensitive ion channel genes: MscL, MscS, and five additional genes that are members of the MscS superfamily. Of these seven genes, six have been shown to gate directly in response …

Synthesis And Validation Of Substrates For Prmt1 Using Plate-Based Screening Assay, Tina Sawatzky, Sarah Mann, Bryan Knuckley

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

PRMT (Protein Arginine Methyltransferase) is a mammalian enzyme that catalyzes methylation of arginine residues in a polypeptide chain. PRMT is categorized as 3 different types. The methylation can occur as asymmetric dimethylation (ADMA, PRMT 1, 2, 3, 4, 6, and 8), symmetric dimethylation (SDMA, PRMT 7, 5 and 9) or monomethylation (MMA, PRMT 7), Type I, II and III respectively. PRMT1 generates ADMA on arginine residues of the Histone H4 N-terminal tail, which can lead to transcription of cancer-related genes. Alternatively, PRMT5 can modify the same arginine residue to produce SDMA, which represses the development of those same cancer-related genes. …

Mapping Out The Electronic And Magnetic Transitions In Mixed-Valent La1-Xsrxmno3 Thin Films, James Payne, Dakota Brown, Calleigh Brannan, Tom Pekarek, Maitri Warusawithana

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

The rich phase diagram in mixed-valent manganites has been intensely studied in bulk crystals as a function of chemical doping. Here we study the effect of doping in La1-xSrxMnO3 thin films by varying the Sr/La ratio between samples. These thin films are grown using ozone assisted molecular beam epitaxy with carefully controlled stoichiometry for a range of doping from x = 0.0 to x = 0.5. Our electronic measurements reveal a crossover from a Mott insulator to a metallic ground state as x is increased. In the metallic ground state we observe a metal-to-insulator transition coincident with a ferromagnetic-to-paramagnetic ordering …

Iceact Monitoring And Data Analysis, Andre Sierra Alderete, John W. Hewitt, Warren Huelsnitz

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

The goal of the IceACT project is to establish an array of small ACTs deployed at the South Pole for neutrino detection, CR composition studies and high energy gamma ray detection. The IceCube Neutrino Observatory at the South Pole has detected these massless subatomic particles called neutrinos. These high-energy astronomical messengers provide us information to investigate the most violent astrophysical sources: events like exploding stars, gamma-ray bursts, and cataclysmic phenomena involving black holes and neutron stars. In particular, these neutrinos have no charge, and can travel across the universe without being scattered by interstellar magnetic fields. The main background for …

Investigation Of The Obscure Spin State Of Ti-Doped Cdse, J. Dimuna, T. Boyett, I. Miotkowski, A. K. Ramdas, T. Pekarek, J. T. Haraldsen

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Using computational and experimental techniques, we examine the nature of the 2+ oxidation of Ti-doped CdSe. Through stoichiometry and confirmed through magnetization measurements, the weakly-doped material of Cd1-xTixSe (x = 0.0043) shows the presence of a robust spin-1 magnetic state of Ti, which is indicative of a 2+ oxidation state. Given the obscure nature of the Ti2+ state, we investigate the electronic and magnetic states using density functional theory. Using a generalized gradient approximation with an onsite potential, we determine the electronic structure, magnetic moment density, and optical properties for a supercell of CdSe with an ultra-low concentration of Ti. …

Investigating The Substrate Specificity Of Prmt1 Using A Plate Based Screening Method, Tina Sawatzky, Sarah Mann, Bryan Knuckley

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Enzymes are biological catalysts that speed up the rate of a reaction by lowering the activation energy and converting substrate (reactant) to product more expeditiously. Enzymes have a high degree of specificity and will only catalyze selective reactions by targeting particular substrates. In mammals, there exists a family of 11 enzymes, PRMT’s (Protein Arginine Methyl transferase), that target protein arginine for post translational methylation on the guanidino nitrogen of the residue. They occur naturally as Type I, II and III and can administer asymmetric di-methylation (ADMA), symmetric dimethylation (SDMA) and monomethylation, respectively. The focal point of this project is to …

Identification Of Histone H4-Based Peptoids As Inhibitors Of Prmt1, Megan Demart, Molly Dubose, Sarah Mann, Corey Causey Phd, Bryan Knuckley Phd

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Protein Arginine Methyltransferases (PRMTs) are a family of 11 mammalian enzymes characterized by the post-translational methylation of arginine residues in the histone tail. The majority of the 11 members of the PRMT family are divided into two main types, Type I and Type II. PRMT1, the major Type I isozyme, catalyzes the formation of asymmetrically dimethylated arginine (ADMA). PRMT1 activates transcription of cancer genes. Peptoids, or poly-N-substituted glycine’s are a class of oligomers whose side chains are appended to the nitrogen atom of the peptide backbone rather than the alpha carbon. Kinetic parameters were conducted for both peptide and peptoid …

Tournaments And A Fibonacci Link, Michael Long, Daniela Genova

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Round robin tournaments are a type of directed graphs with applications to athletic competitions and transportation logistics. The presentation begins with a brief series of informative theorems and properties of directed graphs, which are imperative to our understanding of the properties that make directed graphs (and, subsequently, round robin tournaments) uniquely interesting. We then present a number of results about the properties of tournaments (defined as a complete directed graph), including transitivity–a relatively uncommon property used to determine domination in a round robin tournament–and connectivity, which can most often be seen in determining means of transportation between any two locations. …

Predator-Prey Model With Herding Behavior And Hunting Quota, Randy Lee, Mahbubar Rahman Phd

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

The Lotka-Volterra predator-prey model is widely studied and used in many disciplines such as biology, ecology and economics. It is used to describe the growth and coexistence of two interacting populations. The model consists of a pair of first-order nonlinear differential equations. In this paper, we studied steady states, stability of steady states, existence of limit cycles, and bifurcation behavior of the predator-prey model by modifying the existing model with hunting quota. We also illustrated our results with numerical simulations.

Electronic And Magnetic Order As A Function Of Doping In Mixed-Valent La1-Xsrxmn03 Thin Films, James Payne, Dakota Brown, Calleigh Brannan, Tom Pekarek, Maitri Warusawithana

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

The rich phase diagram in mixed-valent manganites has been intensely studied in bulk crystals as a function of chemical doping. Here we study the effect of doping in La1-xSrxMnO3 thin films by varying the Sr/La ratio between samples. These thin films are grown using ozone assisted molecular beam epitaxy with carefully controlled stoichiometry for a range of doping from x = 0.0 to x = 0.5. Our electronic measurements reveal a crossover from a Mott insulator to a metallic ground state as x is increased. In the metallic ground state we observe a metal-to-insulator transition coincident with a ferromagnetic-to-paramagnetic ordering …

Block Designs, Lucien Poulin, Daniela Genova

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Block designs are a type of combinatorial structures that can be used to model many different types of problems ranging from experimental design to computer software testing. They can be used to construct schemes that ensure complete optimization and efficiency of the given experiment. We focus mainly on Steiner and Kirkman triple systems, as well as, on different ways for constructing block designs. Well known results in combinatorics such as Fisher’s inequality and Kirkman’s schoolgirl problem are also discussed.

Insights From The Influx Of Prescription Painkillers In Northeast Florida: A Retrospective Analysis, Joseph Free, Michelle Dedeo

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

The opioid epidemic has had, and will have, long-lasting ramifications in the United States. To better understand its impact in the Northeast Florida, this research seeks to identify relationships between hydro- and oxycodone pill concentration at the county and zip code levels and socio-economic factors such as average adjusted gross income and opioid related mortality. This project utilizes time series, regression, and GIS methods to examine local opioid saturation and has led to the development of an interactive Tableau dashboard which allows users to view opioid saturation at various levels of granularity. This analysis is made possible by longitudinal data …

Improving Photon Number Resolution In Superconducting Nanowire Single-Photon Detectors With Integrated Impedance Tapers, Bladimiro E. Valbuena, Daniel F. Santavicca

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Simulations are run to optimize the ability to resolve the number of photons detected from the pulse height by a Superconducting Nanowire Single-Photon Detector (SNSPD). This is set up in a manner that features an impedance-matching transmission line taper that provides a characteristic impedance which transitions from kΩ to 50 Ω, with the taper providing an effective load impedance that outputs pulses with not only larger amplitudes but also showed a distinct separation for multi-photon events. The first part of this project tries to computationally match the experimental results obtained by our collaborators at MIT. Once these results are achieved, …

Game Theory Based Distributed Coordination With Multi-Agent Reinforcement Learning, Charlotte M. Morrison

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

We study the problem of automated object manipulation using two arms of a Baxter robot. The robot uses a novel multi-agent reinforcement learning strategy to learn how to complete the task without any prior experience. It learns what actions to take by storing its interactions with the environment and uses these experiences to create a policy that guides future actions. Each of Baxter’s arms is modeled as an independent agent that can move and learn separately from the other. Each arm learns independent policies (i.e., environment state to robot action mapping) about how to best move in order to complete …

Understanding The Magnetic Interactions Of The Zig-Zag Honeycomb Lattice: Application To Rucl3, Evan Wilson, Jason T. Haraldsen

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

The new field of Dirac quantum matter has produced a lot of interesting theories and materials, especially in the dynamics of magnetic materials. One such material is RuCl3, which is a S = 1/2 zigzag honeycomb lattice. Through inelastic neutron scattering, this material has demonstrated spin waves with an energy scale of 1.5-8.0 meV. According to literature, RuCl3 may be the realization of a new theoretical phase of matter called a spin liquid. This materials seems to fit the profile and has been investigated using a Kitaev model. In this study, we re-examine the data for RuCl3 using a standard …

Magnetic Properties Of Mbe Grown La1/3y1/3sr1/3mno3 Thin Films And Superlattices, W. A. Ruiz, C. Kengle, J. Payne, D. Brown, W. P. Warusawithana, T. M. Pekarek

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

We have investigated the magnetic properties of thin films related to the standard CMR system La2/3Sr1/3MnO3 where Y substituted for 50% of the La atoms. These La1/3Y1/3Sr1/3MnO3 films were grown as a random alloy where La, Y, and Sr atoms randomly occupied the A-site or as a superlattice where each unit-cell-thick layer stacked along the crystallographic (001) direction contained only one of the atoms La, Y, and Sr occupying the A-site. One of the key magnetic features of La2/3Sr1/3MnO3 is a prominent ferromagnetic transition near 350 K. We find the substitution of La with Y suppresses this ferromagnetic transition in …

Spin-Glass Ordering In The Diluted Magnetic Semiconductor Zn1-Xmnxte, S. Barrett, T. M. Pekarek

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Magnetic measurements on the spin-glass behavior in the bulk II-VI diluted magnetic semiconductor (DMS) ZnMnTe were made on two crystals of concentrations x = 0.43 and 0.55 taken from the same boule. Magnetization and density functional theory studies have shown paramagnetic behavior in both samples between 30 and 400 K. Below 30 K, there is a prominent peak at Tc = 15 and 23.6 K for concentrations x = 0.43 and 0.55, respectively. The splitting of the field cooled (FC) and zero field cooled (ZFC) data below this peak is indicative of a transition to a spin-glass state at low …

Reduced Dimensionality Effects In Ferromagnetic Behavior In La1-Xsrxmno3, C. A. Brennan, M. P. Warusawithana, J. Payne, D. Brown, T. M. Pekarek

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

We study the magnetic properties of La1-xSrxMnO3 samples for concentrations x, 0 ≤ x ≤ 0.5. An analysis is done to accurately determine the transition temperature or critical temperature. Magnetic phase diagrams showing the various concentrations at different temperatures will be determined for our thin films. Using the phase diagrams for both bulk and thin film materials can show how reducing the dimensionality from the third dimension to approaching the second-dimension affects the phase diagram.