Physical Sciences and Mathematics Commons^™

Many-Particle Systems, 10, David Peak

Many Particles

Intrinsic semiconductors

Intrinsic semiconductors have negligible concentrations of impurity atoms. Their electrical conductivity arises primarily from electrons excited into the otherwise empty conduction band from the otherwise filled valence band—usually by absorbing sufficient energy from phonons at finite temperature. Exciting an electron into the conduction band leaves a vacant state in the valence band. An electron at lower energy in the valence band can fill this vacant state. That, in turn, makes available a possible state for yet another valence band electron to fill. In other words, the excitation of the electron provides a mobile charge in the conduction band …

Chemistry And Biochemistry News, Georgia Southern University

Department of Chemistry and Biochemistry News (2015-2023)

• Chemistry Faculty Win Excellence Awards

Secure Integer Comparisons Using The Homomorphic Properties Of Prime Power Subgroups, Rhys A. Carlton

Electronic Thesis and Dissertation Repository

Secure multi party computation allows two or more parties to jointly compute a function under encryption without leaking information about their private inputs. These secure computations are vital in many fields including law enforcement, secure voting and bioinformatics because the privacy of the information is of paramount importance.

One common reference problem for secure multi party computation is the Millionaires' problem which was first introduced by Turing Award winner Yao in his paper "Protocols for secure computation". The Millionaires' problem considers two millionaires who want to know who is richer without disclosing their actual worth.

There are public-key cryptosystems that …

Influences Of Hurricanes, Floods, And Organic Production On River-Delta Evolution Over Decadal To Centennial Time-Scales, Crawford M. White

LSU Doctoral Dissertations

Episodic overbank flooding and sediment resuspension events (such as cold front passages or tropical cyclones) are recognized as important natural components for wetlands maintaining vertical equilibrium with sea-level. However, the relative importance of these components to an anthropogenically unmodified delta complex remains unclear. This study uses sediment cores to describe the relative importance of these vertical accretion components the Lafourche and Balize Deltas of the Mississippi River. Existing wetlands of the abandoned lower Lafourche receive no direct fluvial sediment, but instead are supported by sediment resuspended by tropical cyclones and cold fronts that pass over them. Wetlands of the modern …

Optical Sensing And Separation Based On Ordered Three-Dimensional Nanostructured Surfaces, Mathias Schubert, Tino Hofmann, Daniel Schmidt, Patrick H. Dussault, Andrea Homes, Rebecca Lai

Patrick Dussault Publications

A sensor having a substrate is provided in which structures are disposed on a surface of the substrate . The structures can be , e . g . , nanostructures . Polarized light is directed toward the sensor , and birefringence of the structures with respect to the light is measured . Target particles that interact with the structures are detected based on changes in the measured birefringence .

Molecular Basis For The Substrate Specificity Of Quorum Signal Synthases, Shi-Hui Dong, Nicole D. Frane, Quin H. Christensen, E. Peter Greenberg, Rajesh Nagarajan, Satish K. Nair

Chemistry and Biochemistry Faculty Publications and Presentations

In several Proteobacteria, LuxI-type enzymes catalyze the biosynthesis of acyl–homoserine lactones (AHL) signals using S-adenosyl– L-methionine and either cellular acyl carrier protein (ACP)-coupled fatty acids or CoA–aryl/acyl moieties as progenitors. Little is known about the molecular mechanism of signal biosynthesis, the basis for substrate specificity, or the rationale for donor specificity for any LuxI member. Here, we present several cocrystal structures of BjaI, a CoAdependent LuxI homolog that represent views of enzyme complexes that exist along the reaction coordinate of signal synthesis. Complementary biophysical, structure–function, and kinetic analysis define the features that facilitate the unusual acyl conjugation with S-adenosylmethionine …

Uv Screening In Native And Non-Native Plant Species In The Tropical Alpine: Implications For Climate Change-Driven Migration Of Species To Higher Elevations, Paul W. Barnes, Ronald J. Ryel, Stephan D. Flint

Wildland Resources Faculty Publications

Ongoing changes in Earth’s climate are shifting the elevation ranges of many plant species with non-native species often experiencing greater expansion into higher elevations than native species. These climate change-induced shifts in distributions inevitably expose plants to novel biotic and abiotic environments, including altered solar ultraviolet (UV)-B (280–315 nm) radiation regimes. Do the greater migration potentials of non-native species into higher elevations imply that they have more effective UV-protective mechanisms than native species? In this study, we surveyed leaf epidermal UV-A transmittance (TUVA) in a diversity of plant species representing different growth forms to test whether native and non-native species …

On Lower Bounds For S-Multiplicities, Lance Edward Miller, William D. Taylor

Mathematical Sciences Faculty Research

A recent continuous family of multiplicity functions on local rings was introduced by Taylor interpolating between Hilbert-Samuel and Hilbert-Kunz multiplicities. The obvious goal is to use this as a tool for deforming results from one to the other. The values in this family which do not match these classic variants however are not known yet to be well-behaved. This article explores lower bounds for these intermediate multiplicities as well as gives evidence for analogies of the Watanabe-Yoshida minimality conjectures for unmixed singular rings.

Effect Of Bottom Friction, Wind Drag Coefficient, And Meteorological Forcing In Hindcast Of Hurricane Rita Storm Surge Using Swan + Adcirc Model, Muhammad K. Akbar, Simbarashe Kanjanda, Abram Musinguzi

Mechanical and Manufacturing Engineering Faculty Research

An evaluation of the effect of bottom friction, wind drag coefficient, and meteorological forcing is conducted using a tightly coupled wave and circulation model, SWAN + ADCIRC (i.e., Simulating WAves Nearshore + ADvanced CIRCulation), to hindcast the storm surge of Hurricane Rita (2005). Wind drag coefficient formulations of Powell, Zijlema, and Peng & Li are used to calculate wind stresses. Bottom friction and wind drag coefficients are systematically increased and decreased to quantify their impacts on the hindcast. Different meteorological forcing options are applied to study the effect of wind fields on storm surge development and propagation. Simulated water levels …

Systematic Adaptation Of Dynamically Generated Source Code Via Domain-Specific Examples, Myoungkyu Song, Eli Tilevich

Computer Science Faculty Publications

In modern web-based applications, an increasing amount of source code is generated dynamically at runtime. Web applications commonly execute dynamically generated code (DGC) emitted by third-party, black-box generators, run at remote sites. Web developers often need to adapt DGC before it can be executed: embedded HTML can be vulnerable to cross-site scripting attacks; an API may be incompatible with some browsers; and the program's state created by DGC may not be persisting. Lacking any systematic approaches for adapting DGC, web developers resort to ad-hoc techniques that are unsafe and error-prone. This study presents an approach for adapting DGC systematically that …

Cytidine Deaminase As A Molecular Target In Cancer: An Insight, Claudia A. Almaraz, Debasish Bandyopadhyay

Chemistry Faculty Publications and Presentations

Cancer is one of the leading causes of death globally. Although more than 400 varieties of cancer have been reported, based on cell lines, still the actual reason of all types of cancer is not very clear. Several internal and external factors have been identified and the study is ongoing. Up to now about 73 proteins have been identified that are capable to influence directly various phases of cancer including mutation, cell proliferation, invasion, angiogenesis, and metastasis. Cytidine deaminase is one of the important proteins that is responsible for various types of cancer that includes gastric, liver, biliary tract, bladder, …

Nonlinear Oscillatory Dynamics Of The Hardening Of Calcium Phosphate Bone Cements, Vuk Uskoković, Julietta V. Rau

Pharmacy Faculty Articles and Research

Here we report on the nonlinear, oscillatory dynamics detected in the evolution of phase composition during the setting of different calcium phosphate cements, two of which evolved toward brushite and one toward hydroxyapatite as the final product. Whereas both brushite-forming cements contained iondoped b-tricalcium phosphate as the initial phase, the zinc-containing one yielded scholzite as an additional phase during setting and the oscillations between these two products were pronounced throughout the entire 80 h setting period, long after the hardening processes was over from the mechanical standpoint. Oscillations in the copper-containing system involved the amount of brushite as the main …

Automated Breast Cancer Diagnosis Using Deep Learning And Region Of Interest Detection (Bc-Droid), Richard Platania, Jian Zhang, Shayan Shams, Kisung Lee, Seungwon Yang, Seung Jong Park

Computer Science Faculty Research & Creative Works

Detection of suspicious regions in mammogram images and the subsequent diagnosis of these regions remains a challenging problem in the medical world. There still exists an alarming rate of misdiagnosis of breast cancer. This results in both over treatment through incorrect positive diagnosis of cancer and under treatment through overlooked cancerous masses. Convolutional neural networks have shown strong applicability to various image datasets, enabling detailed features to be learned from the data and, as a result, the ability to classify these images at extremely low error rates. In order to overcome the difficulty in diagnosing breast cancer from mammogram images, …

Secondary Gravity Wave Generation Over New Zealand During The Deepwave Campaign, Katrina Bossert, Christopher G. Kruse, Christopher J. Heale, David C. Fritts, Bifford P. Williams, Jonathan B. Snively, Pierre-Dominique Pautet, Michael J. Taylor

Publications

Multiple events during the Deep Propagating Gravity Wave Experiment measurement program revealed mountain wave (MW) breaking at multiple altitudes over the Southern Island of New Zealand. These events were measured during several research flights from the National Science Foundation/National Center for Atmospheric Research Gulfstream V aircraft, utilizing a Rayleigh lidar, an Na lidar, and an Advanced Mesospheric Temperature Mapper simultaneously. A flight on 29 June 2014 observed MWs with horizontal wavelengths of ~80–120 km breaking in the stratosphere from ~10 to 50 km altitude. A flight on 13 July 2014 observed a horizontal wavelength of ~200–240 km MW extending from …

Oxidization Of Al And A-Si As A Protective Layer, Yhoshua Wug

Student Works

Arguably, the best chance to produce a IR-optical-UV-EUV mirror for a future space observatory is a multilayer mirror coated by a thin bare aluminum layer. Using an Al layer presents challenges that have to be overcome first. Al oxidizes rapidly as soon as it comes in contact with the atmosphere. One solution is to block the oxidation of Al by covering the mirror with a protective layer and remove it once the mirror is in space. freshly, deposited a-Si would be a good candidate for protecting the mirror. Removing it in space also presents some challenges. The best way to …

Measurements Of E+E− Pairs From Open Heavy Flavor In P + P And D + A Collisions At √ Snn = 200 Gev, Gyöngyi Baksay, László A. Baksay, C. Baumann, Klaus Dehmelt, Marcus Hohlmann, Jun Kikuchi, Christian Klein-Boesing, S. Rembeczki, Klaus Johannes Reygers, Baldo Sahlmueller, Johannes P. Wessels, Yoshio Yamaguchi, A. Adare

Aerospace, Physics, and Space Science Faculty Publications

We report a measurement of e+e- pairs from semileptonic heavy-flavor decays in p+p collisions at sNN=200 GeV. The e+e- pair yield from bb and cc is separated by exploiting a double differential fit done simultaneously in dielectron invariant mass and pT. We used three different event generators, pythia, mc@nlo, and powheg, to simulate the e+e- spectra from cc and bb production. The data can be well described by all three generators within the detector acceptance. However, when using the generators to extrapolate to 4π, significant differences are observed for the total cross section. These difference are less pronounced for bb …

Developing Instrumentation For Fabricating And Characterizing Thin Film Aluminum Mirrors, P. Claire Segura

Student Works

The best material for constructing a mirror for a broad-bandwidth telescope that is also capable of reflecting EUV light is pure aluminum. In order to test how the reflectance of aluminum in the EUV range changes as it oxidizes, a system has been constructed that allows a thin aluminum mirror to be constructed inside of a vacuum, where its reflectance can then be tested immediately. Because the experiment must take place in a vacuum, it must also be controlled remotely through a computer program, which manages the mirror fabrication process as well as the collection and analysis of reflectance data. …

Exploring The Solvability Of The Jaynes-Cummings And Jaynes-Cummings-Like Models: Implementing Quantum Control, Austen Couvertier

Student Works

In this paper we aim to explore the dynamics and overall solvability of the Jaynes-Cummings \& Jaynes-Cummings-Like models. As a lens to understand these dynamics, we focused on cases where the parameters of the system were made time-dependent. All previous work on solving the dynamics of the Jaynes-Cummings models has relied heavily on the use of differential methods and setting the parameters as time-independent constants which were zero or one. To account for this, we utilized the Wei-Norman method which allowed us to analytical solve the time-dependent Hamiltonian. Through the use of this method, we can understand the more general …

An Exploration Of Crum’S And Algebraic Crum Detection, Shae Machlus, Branton Campbell

Student Works

1. The cooperative rigid unit modes (CRUM's) of cubic perovskite were investigated at non-special k-points using ISODISTORT and Shared Shifts Mathematica code. CRUM's were generated by the T₄ irrep on the T line which confirms previously published results.
2. The solution space of the MtM CRUM detection method was determined and compared to that of the M method. Analysis by example and by theory showed the solution spaces of both methods are identical. MtM was realized to be effectively M with a lower tolerance. An improved row reduction routine is being developed that uses an adaptable ratio-driven tolerance instead of …

Reflectance Of Xuv Light On A Two Dimensional Conducting Rough Surface, Chelsea Thangavelu

Student Works

A Fortran program is set up to solve for the reflectance of XUV light from a rough two dimensional surface, resembling experimental mirrors used to reflect XUV light. Because the roughness of the surface is on the order of magnitude of the wavelength of XUV light, our approach requires a Greene's Function instead of using traditional geometrical optics or physical optics. Our Fortran program calculates the impedance (Z) matrix which requires integration over Greene's Function at non-singular points. The Z matrix helps solve for the induced surface current J(x') at non-singular points. At singular points, the program implements a series …

Observing Kelt Candidate Objects In The Search For Transiting Exoplanets, Maria Martinez

Student Works

The main goal of this project was to learn how to participate and be a part of a real observational team. We worked with the KELT exoplanet search project. While working with the KELT project we hoped to be able to confirm a candidate object as a planet. However, trying to discover a transiting planet was not our main goal for the summer. In addition, we also set out to learn how to work in an observatory, operate telescopes, and process data. The different objects we observed throughout the summer were not all determined to be transiting exoplanets, but we …

Search For Top Quark Partners With Charge 5/3 In Proton-Proton Collisions At √S=13 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A search for the production of heavy partners of the top quark with charge 5/3 (X5/3) decaying into a top quark and a W boson is performed with a data sample corresponding to an integrated luminosity of 2.3 fb−1, collected in proton-proton collisions at a center-of-mass energy of 13 TeV with the CMS detector at the CERN LHC. Final states with either a pair of same-sign leptons or a single lepton, along with jets, are considered. No significant excess is observed in the data above the expected standard model background contribution and an X5/3 quark with right-handed (left-handed) couplings is …

The Effect Of Hydrogen Bonding In Enhancing The Ionic Affinities Of Immobilized Monoprotic Phosphate Ligands, Spiro D. Alexandratos, Xiaoping Liu

Publications and Research

Environmental remediation requires ion-selective polymers that operate under a wide range of solution conditions. In one example, removal of trivalent and divalent metal ions from waste streams resulting from mining operations before they enter the environment requires treatment at acidic pH. The monoethyl ester phosphate ligands developed in this report operate from acidic solutions. They have been prepared on polystyrene-bound ethylene glycol, glycerol, and pentaerythritol, and it is found that intra-ligand hydrogen bonding affects their metal ion affinities. The affinity for a set of trivalent (Fe(III), Al(III), La(III), and Lu(III)) and divalent (Pb(II), Cd(II), Cu(II), and Zn(II)) ions is greater …

Renewable Hydrogels From Norbornene-Functionalized Carboxymethyl Cellulose And A Short Dithiol Crosslinked Via A Thiol-Ene Reaction, Thomas Mcoscar

Electronic Theses and Dissertations

Cellulose-based hydrogels - three dimensional "solid" structures composed primarily of liquid water and held together by an interconnected polymer network - were created by first functionalizing carboxymethyl cellulose (CMC), a cellulose derivative, with carbic anhydride in a basic aqueous reaction with the intent of developing novel hydrogels from renewable materials. The product of this reaction, carbic CMC (cCMC), had a new norbornene group as a subsection of the carbic group. Norbornene is a reactive alkene structure that allows for further chemistry with cCMC, such as crosslinking. cCMC was crosslinked with 2,2'-(ethylenedioxy)diethathiol to create hydrogels using a water-soluble, UV-sensitive radical initiator …

Using Hydroacoustics To Investigate Biological Responses In Fish Abundance To Restoration Efforts In The Penobscot River, Maine, Constantin C. Scherelis

Electronic Theses and Dissertations

Spatiotemporal advantages linked to hydroacoustic sampling techniques have caused a surge in the use of these techniques for fisheries monitoring studies applied over long periods of time in marine systems. Dynamic physical conditions such as tidal height, boat traffic, floating debris, and suspended particle concentrations result in unwanted noise signatures that vary in intensity and location within a hydroacoustic beam over time and can be mixed with the acoustic returns from intended targets (e.g., fish). Typical processing filters applied over long term datasets to minimize noise and maximize signals do not address spatiotemporal fluctuations of noise in dynamic systems. We …

Oyster Aquaculture Site Selection Using Landsat 8-Derived Sea Surface Temperature, Turbidity, And Chlorophyll A., Jordan Snyder

Electronic Theses and Dissertations

Remote sensing data is useful for selection of aquaculture sites because it can provide water-quality products mapped with no cost to users. However, the spatial resolution of most ocean color satellites is too coarse to provide usable data within many estuaries. The more recently launched Landsat 8 satellite has both the spatial resolution and the necessary signal to noise ratio to provide temperature, as well as ocean color derived products along complex coastlines. The state of Maine (USA) has an abundance of estuarine indentations (~3,500 miles of tidal shoreline within 220 miles of coast), and an expanding aquaculture industry, which …

Rethinking Urban Green Infrastructure As A Means To Promote Avian Conservation, Allen Lau

Master's Projects and Capstones

There is an under-recognized potential for cities to use urban green infrastructure to contribute to avian biodiversity conservation. At the global scale, climate change and growing urbanization are primary global drivers leading to decline and homogenization in world bird populations. Birds are fundamental and intricate species in ecosystems, and even in urban areas, act as indicator and regulator species contributing to healthy ecosystem function. While many cities have recognized the economic and social benefits associated with green spaces, such as the vast benefits ecosystem services provide to the urban dweller, the use of green spaces to concurrently contribute to avian …

Neurological Impact Of Zinc Excess And Deficiency In Vivo, Ronald Bartzatt

Chemistry Faculty Publications

Zinc is an essential mineral that can cause pathological effects whether in excess or deficiency. Zinc is a component for over 250 enzymes and is required for cell growth, cell division, and cell function. Zinc is found in muscle and bones, with the prostrate, liver, skin, and kidney having detectable levels of zinc. However, zinc present in excess or deficiency can cause significant pathology in patients that include deleterious effects neurologically. Zinc in excess in vivo can cause focal neuronal pathology, while zinc deficiency can bring about mental lethargy, neuropsychiatric disorders, and reduced nerve conduction. Zinc is assimilated within the …

Creating Renewable Tunable Polymers From Hydroxymethylfurfural, Meredith C. Allen

Electronic Theses and Dissertations

The research here deals with the conversion of 5-hydroxymethylfurfural (HMF) into a tunable polymer. HMF is a known derivative that can be acquired from biomass via hydrolysis of cellulose followed by isomerization and finally selective dehydration. The process considered here is being developed to create tunable polymers from HMF and involves several different steps, three of which are covered here. The first step, an etherification, is the reaction of HMF with an alcohol. This step is significant because in this step the R-group from the alcohol is added to HMF and the branching portion formed is carried over to the …

Annuity Product Valuation And Risk Measurement Under Correlated Financial And Longevity Risks, Soohong Park

Electronic Thesis and Dissertation Repository

Longevity risk is a non-diversifiable risk and regarded as a pressing socio-economic challenge of the century. Its accurate assessment and quantification is therefore critical to enable pension-fund companies provide sustainable old-age security and maintain a resilient global insurance market. Fluctuations and a decreasing trend in mortality rates, which give rise to longevity risk, as well as the uncertainty in interest-rate dynamics constitute the two fundamental determinants in pricing and risk management of longevity-dependent products. We also note that historical data reveal some evidence of strong correlation between mortality and interest rates and must be taken into account when modelling their …