Engineering Physics Commons^™

Simulation Of Optical Properties Of Dielectric Layers From Visible To Near Infrared Spectral Range, Andrew Cochran, Cory Conkel

ONU Student Research Colloquium

Optical properties of dielectrics play a critical role in various applications including the design and manufacture of optical components & devices such as detectors, filters, imagers, lenses, optical coatings, photonic crystals, sensors and waveguides, and solar cells. Radiative properties of varying thicknesses of different dielectrics such as Aluminum Oxide (Al2O3), Silicon Dioxide (SiO2), Indium Tin Oxide (ITO), Magnesium Fluoride (MgF2) and Silicon Nitride (Si3N4) have been simulated and compared in the range of visible to near infrared by mathematical modelling using MATLAB simulations. The results of the evolution of the radiative properties, as a function of dielectric material thickness, on …

E. Coli And Total Coliform, Emilio Wilson

Undergraduate Research Competition

Water is important because we use it for our everyday use, whether it's for drinking, bathing, or for our enjoyment. Pollution causes the environment to have a harmful effect, which is usually caused by microorganisms (bacteria) Some of those Bacteria include E. coli and Total Coliform. They're mainly found in the intestines of humans, in animals, in water, and also found in the soil. Most of these bacteria are harmless but it can provide you with symptoms of diarrhea, vomiting, and stomach cramps. When water comes in contact with feces, humans, or any living organism, the water is contaminated. There …

Water Monitoring At Ccu (Conductivity, Ph, Do), Gage Campbell

Undergraduate Research Competition

Monitoring water quality is important for human health. This study focuses on the 544 West site and the parameters conductivity, pH, and dissolved oxygen (DO). Data used is from Oct. 2011 through Nov. 2020 on the Coastal Carolina University campus and used an Orion™ A329 multimeter. 741 samples were collected for Conductivity, with an average of 407.8 uS/cm (145.8 uS/cm - 690.7 uS/cm). 738 samples were collected for pH, with an average of 7.15 (6.09 - 8.11). All data fell within the SC DHEC water quality standard of pH which is no lower than 5.0 or above 8.5. 735 samples …

Detecting Radium-226 In Submarine Groundwater Discharge, Rashaun Davis

Undergraduate Research Competition

Studies have been done to see if abundance of neutrinos have an effect on the decay rate of radioactive nuclei. Questions regarding the proximity of the sun and the concentration of the flux of neutrinos as a result, have emerged due to there being more counts in the winter when the sun is closer versus there being less counts in the summer when the sun is farther away. Other studies say that the cause of the difference in counts are more local, as in the environmental conditions like temperature and various background radiation that interferes with the counts of the …

Design Of Smart Trashcan, Haoran Song

Senior Theses

A smart trashcan has been designed which can bring convenience to people for throwing their garbage away during the COVID-19 pandemic. A prototype is made from cardboard to demonstrate its function. This trashcan can sense people who are coming and leaving, and it can open and close automatically. The trashcan is powered by solar energy. A solar panel is mounted on top of the trashcan supporter. This design is specifically for use in China.

Deathtrap, Blake Traylor

Vázquez-Valarezo Poetry Award

I could have titled this one "Bad Trip in an Elevator," but that would twist the poem away from its authenticity. You'll have to trust me on this one: this happened. Not in the usual sense, but in that fiction-is-truth-in-a-funhouse-mirror, postmodern Tim O'Brien sense. And hallucinogens were not involved, nor are they encouraged or condoned. (Do with that Wretched Passive Voice what you will.)

If the word "Deathtrap" didn't amuse me so much, I really could have run with the title "Tired." Or maybe "Very Tired" would have been better. And then there are always the big-hitters: "Fatigue," "Exhaustion," "Are …

Investigation Of Trajectory And Control Designs For A Solar Sail To The Moon, Michelle Nadeau

Doctoral Dissertations and Master's Theses

NASA’s Artemis program and other government and commercial projects are working toward establishing a sustainable human presence on the moon. This thesis investigates the technical feasibility of a solar sail-based spacecraft (sailcraft) as a low-cost method of delivering cargo or science instruments to the moon and demonstrates how this sailcraft could be controlled to change its orbit. The concept is a low-cost, commercial launch vehicle-deployable, CubeSat-based sailcraft with a square sail, assumed attitude control, and a small payload traversing from low-Earth orbit toward the moon with zero propellant use. In this thesis, methods for sailcraft to increase altitude, the trajectory …

Zn Acceptors In Β-Ga2O3 Crystals, Timothy D. Gustafson, J. Jesenovec, Christopher A. Lenyk, Nancy C. Giles, J. S. Mccloy, M. Mccluskey, Larry E. Halliburton

Faculty Publications

Electron paramagnetic resonance (EPR) is used to identify and characterize neutral zinc acceptors in Zn-doped β-Ga₂O₃ crystals. Two EPR spectra are observed at low temperatures, one from Zn ions at tetrahedral Ga(1) sites (the Zn⁰_Ga1 acceptor) and one from Zn ions at octahedral Ga(2) sites (the Zn⁰_Ga2 acceptor). These Zn acceptors are small polarons, with the unpaired spin localized in each case on a threefold coordinated oxygen O(I) ion adjacent to the Zn ion. Resolved hyperfine interactions with neighboring ⁶⁹Ga and ⁷¹Ga nuclei allow the EPR spectra from the two acceptors …

Erratum: A Non-Linear Approximate Solution To The Damped Pendulum Derived Using The Method Of Successive Approximations [Georgia Journal Of Science, Vol. 76, No. 2, Article 9], Javier E. Hasbun

Georgia Journal of Science

In an earlier publication [Hill and Hasbun, 2018] considered an approximate solution to the damped pendulum, named the improved modified method of successive approximations (IMMSA), and compared it to an approximation from the work of [Johannessen, 2014]. Here, a correction is made to that comparison due to an error made in calculating Johannessen's approximation.

Correction To "Quantitative Study Of The Energy Changes In Voltage-Controlled Spin Crossover Molecular Thin Films" [The Journal Of Physical Chemistry Letters (2020) 11:19 (8231-8237) Doi: 10.1021/Acs.Jpclett.0c02209], Aaron Mosey, Ashley S. Dale, Guanhua Hao, Alpha N'Diaye, Peter Dowben, Ruihua Cheng

Peter Dowben Publications

In our recent publication, Figure 5 was published without adequate due diligence. The correct TOC Abstract graphic and Figure 5 are contained here in this correction. The correct on to off current ratios are in the range of 4 to 5, not 100 and the signal to noise ratios are far less than previously shown.

Nonvolatile Voltage Controlled Molecular Spin‐State Switching For Memory Applications, Thilini K. Ekanayaka, Guanhua Hao, Aaron Mosey, Ashley S. Dale, Xuanyuan Jiang, Andrew J. Yost, Keshab R. Sapkota, George T. Wang, Jian Zhang, Alpha T. N’Diaye, Andrew Marshall, Ruihua Cheng, Azad Naeemi, Xiaoshan Xu, Peter Dowben

Peter Dowben Publications

Nonvolatile, molecular multiferroic devices have now been demonstrated, but it is worth giving some consideration to the issue of whether such devices could be a competitive alternative for solid-state nonvolatile memory. For the Fe (II) spin crossover complex [Fe{H₂B(pz)₂}₂(bipy)], where pz = tris(pyrazol-1-yl)-borohydride and bipy = 2,20-bipyridine, voltage-controlled isothermal changes in the electronic structure and spin state have been demonstrated and are accompanied by changes in conductance. Higher conductance is seen with [Fe{H₂B(pz)₂}₂(bipy)] in the high spin state, while lower conductance occurs for the low spin state. Plausibly, …

Comparing Radiation Shielding Potential Of Liquid Propellants To Water For Application In Space, John Czaplewski

Master's Theses

The radiation environment in space is a threat that engineers and astronauts need to mitigate as exploration into the solar system expands. Passive shielding involves placing as much material between critical components and the radiation environment as possible. However, with mass and size budgets, it is important to select efficient materials to provide shielding. Currently, NASA and other space agencies plan on using water as a shield against radiation since it is already necessary for human missions. Water has been tested thoroughly and has been proven to be effective. Liquid propellants are needed for every mission and also share similar …

Nonlinear Solution Of The Time Eigenvalue Of A Fast Burst Reactor Using The Finite Volume Method, Stephen H. Baxter

Theses and Dissertations

This effort models fast burst reactors using the one dimensional, one group neutron diffusion equation to solve for the time eigenvalue, a method for which an analytical solution exists against which the numerical results can be verified. An existing solution method is enhanced by the addition of a second order accurate finite volume discretization, which is then used to model two separate fast burst reactors. The results of these models are then compared to the results of previous work, the analytical solution, and existing experimental burst width data for each of the two reactors.

Topological Realizations Of Entangling Quantum Gates, Adrian D. Scheppe

Theses and Dissertations

Topological systems are immune to decoherence and provide a hunting ground for qubits that are fault tolerant. The process of calculating linear operator representations of Majorana fermion exchanges or braids is well known and well documented; however, there is no documented intuition or algorithm which provides the opposite; braids from quantum gates. In this document, all possible linear representations of single, double, triple, and quadruple qubit gates are calculated to find several key patterns which provide crucial insight into the manifestation of qubit gates. A n x n gate will require n + 2 Majoranas with ½n + 1 trivial …

A Comparison Of Sporadic-E Occurrence Rates Using Ionosondes And Gps Radio Occultation Measurements, Rodney A. Carmona Jr.

Theses and Dissertations

Sporadic-E (Es) occurrence rates from Global Position Satellite radio occultation (GPS-RO) measurements have shown to vary by nearly an order of magnitude between studies, motivating a comparison with ground-based measurements. In an attempt to find an accurate GPS-RO technique for detecting Es formation, occurrence rates derived using five previously developed GPS-RO techniques are compared to ionosonde measurements over an eight-year period from 2010-2017. GPS-RO measurements within 170 km of a ionosonde site are used to calculate Es occurrence rates and compared to the ground-truth ionosonde measurements. Each technique is compared individually for each ionosonde site and then combined to determine …

Remote Mesoscopic Signatures Of Induced Magnetic Texture In Graphene, N. Arabchigavkani, R. Somphonsane, H. Ramamoorthy, G. He, J. Nathawat, S. Yin, B. Barut, K. He, M. D. Randle, R. Dixit, K. Sakanashi, N. Aoki, K. Zhang, L. Wang, W. N. Mei, Peter Dowben, J. Fransson, J. P. Bird

Peter Dowben Publications

Mesoscopic conductance fluctuations are a ubiquitous signature of phase-coherent transport in small conductors, exhibiting universal character independent of system details. In this Letter, however, we demonstrate a pronounced breakdown of this universality, due to the interplay of local and remote phenomena in transport. Our experiments are performed in a graphene-based interaction-detection geometry, in which an artificial magnetic texture is induced in the graphene layer by covering a portion of it with a micromagnet. When probing conduction at some distance from this region, the strong influence of remote factors is manifested through the appearance of giant conductance fluctuations, with amplitude much …

Investigation Of The Interfacial Energy Level Within Organic Semiconducting Devices, Wong Wah Seng

Student Works (2020-2029)

This main goal of this research is investigating the interfacial energy level of organic semiconducting devices by correlated to the devices performance as well as physical/chemical change in the blended/mixed organic semiconductor system. The first project reported the high efficiency extra warm white organic light emitting diodes (WOLEDs) by blending tris(4-carbazoyl-9-ylphenyl)amine (TcTa) to poly(vinylcarbazole) (PVK). The hole current for PVK:TcTa (60:40) increased by one order of magnitude in hole only device, but the current efficiency of WOLEDs improved only by 7% compared to pristine PVK. Using Ultraviolet photoelectron spectroscopy (UPS), it was discovered the hole injection barrier between poly(3,4-ethylenedioxythiophene) polystyrene …

Study Of Schottky And Poole-Frenkel Conduction Mechanism In Fe304-Gamma-Fe2o3/Sio2/N-Type Si System, Adrian Chung Ning Hann

Student Works (2020-2029)

The advances of metal oxide semiconductor technology (MOS) have led to smaller devices being made where sizes of the devices keep getting smaller and compact. Hence, all the components of metal oxide semiconductor sizes are to be reduced without affecting the overall efficiency of the metal oxide semiconductor. However, there is a problem in the silicon dioxide component of MOS as the sizes of the silicon oxide (SiO2) reduces, there is a possibility a current leakage to occur due to carrier direct tunneling effect passing through SiO2 which reduce the efficiency of the MOS. Therefore, a higher dielectric constant material …

Electronic Properties Of Dna From Selected Pleurotus Species Using Dna Specific Schottky Diodes, Nastaran Rizan

Student Works (2020-2029)

The exciting discovery of the semiconducting-like properties of deoxyribonucleic acid (DNA) and its potential applications in molecular genetics and diagnostics in recent times has resulted in a paradigm shift in biophysics research. In this aspect, recent studies are being conducted towards detecting charge transfer mechanism to understand the electronic properties of DNA based on its sequence-specific electronic response. This current research aims to contribute towards this effort by fabricating and developing DNA-specific Schottky barrier diodes for characterizing and identifying mushrooms using current-voltage (I-V) profiles. Selected electronic properties such as ideality factor, barrier height, shunt resistance, series resistance, turn-on voltage, knee-voltage, …

Synthesis And Characterization Of Perovskite-Based Materials For Memory Device Application, Gregory Thien Soon How

Student Works (2020-2029)

This project aims to study the resistive switching behaviour in memory devices using perovskites-based structures. A hybrid organic-inorganic lead halide perovskite was studied in this project, specifically methylammonium lead triiodide, CH3NH3PbI3 or MAPbI3 perovskite. The effect of the various counter electrodes in MAPbI3 perovskite was investigated by fabricating MAPbI3 perovskite on Indium Tin Oxide (ITO). Three commonly used electrodes which are Aluminium (Al), Silver (Ag), and Gold (Au) were thermally evaporated on top of the MAPbI3 perovskite layer. It was found that the ITO/MAPbI3/Al exhibits Resistive Random Access Memory (ReRAM) behaviour with SET voltage (VSET) of 4.5 V and RESET …