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Chemistry And Biochemistry News, Georgia Southern University

Department of Chemistry and Biochemistry News (2015-2023)

• Dr. Carpenter receives COSM Excellence in Teaching Award-2019

Us County-Level Agricultural Crop Production Typology, Courtney R. Hammond Wagner, Meredith T. Niles, Eric D. Roy

College of Agriculture and Life Sciences Faculty Publications

Objectives: Crop production is an important variable in social, economic and environmental analyses. There is an abundance of crop data available for the United States, but we lack a typology of county-level crop production that accounts for production similarities in counties across the country. We fill this gap with a county-level classification of crop production with ten mutually exclusive categories across the contiguous United States. Data description: To create the typology we ran a cluster analysis on acreage data for 21 key crops from the United States Department of Agriculture's 2012 Agricultural Census. Prior to clustering, we estimated undisclosed county …

(0,1)-Matrices, Discrepancy And Preservers, Leroy B. Beasley

Mathematics and Statistics Faculty Publications

Let m and n be positive integers, and let R = (r₁, . . . , r_m) and S = (s₁, . . . , s_n) be nonnegative integral vectors. Let A(R,S) be the set of all m × n (0, 1)-matrices with row sum vector R and column vector S. Let R and S be nonincreasing, and let F(R) be the m × n (0, 1)-matrix, where for each i, the ith row of F(R, …

Anisotropic Singlet Fission In Single Crystalline Hexacene, Dezheng Sun, Gang-Hua Deng, Bolei Xu, Enshi Xu, Xia Li, Yajing Wu, Yuqin Qian, Yu Zhong, Colin Nuckolls, Avetik R. Harutyunyan, Hai-Lung Dai, Gugang Chen, Hanning Chen, Yi Rao

Chemistry and Biochemistry Faculty Publications

Singlet fission is known to improve solar energy utilization by circumventing the Shockley-Queisser limit. The two essential steps of singlet fission are the formation of a correlated triplet pair and its subsequent quantum decoherence. However, the mechanisms of the triplet pair formation and decoherence still remain elusive. Here we examined both essential steps in single crystalline hexacene and discovered remarkable anisotropy of the overall singlet fission rate along different crystal axes. Since the triplet pair formation emerges on the same timescale along both crystal axes, the quantum decoherence is likely responsible for the directional anisotropy. The distinct quantum decoherence rates …

Targeted Germanium Ion Irradiation Of Aluminum Gallium Nitride/Gallium Nitride High Electron Mobility Transistors, Melanie E. Mace

Theses and Dissertations

Microscale beams of germanium ions were used to target different locations of aluminum galliumnitride/gallium nitride (AlGaN/GaN) high electron mobility transistors (HEMTs) to determine location dependent radiation effects. 1.7 MeV Ge ions were targeted at the gap between the gate and the drain to observe displacement damage effects while 47 MeV Ge ions were targeted at the gate to observe ionization damage effects. Electrical data was taken pre, during, and post irradiation. To separate transient from permanent degradation, the devices were characterized after a room temperature anneal for at least 30 days. Optical images were also analyzed pre and post irradiation. …

Convective Instabilities Derived From Dissipation Of Chemical Energy, Reuben H. Simoyi, Matthew W. Eskew

Chemistry Faculty Publications and Presentations

Oxidation reactions of a series of organosulfur compounds by chlorite are excitable, autocatalytic, and exothermic and generate a lateral instability upon being triggered by the autocatalyst. This article reports on the convective instabilities derived from the reaction of chlorite and thiourea in a Hele-Shaw cell. Reagent concentrations used for the development of convective instabilities delivered a temperature jump at the wave front of 2.1 K. The reaction zone was 2 mm and due to normal cooling after the wave front, this induced a spike rather than the standard well-studied front propagation. Localized spatiotemporal patterns develop around the wave front. This …

On The Pulsed Laser Ablation Of Metals And Semiconductors, Todd A. Van Woerkom

Theses and Dissertations

This dissertation covers pulsed laser ablation of Al, Si, Ti, Ge, and InSb, with pulse durations from tens of picosecond to hundreds of microseconds, fluences from ones of J/cm² to over 10,000 J/cm², and in ambient air and vacuum. A set of non-dimensional scaling factors was created to interpret the data relative to the laser and material parameters, and it was found that pulse durations shorter than a critical timescale formed craters much larger than the thermal diffusion length, and longer pulse durations created holes much shallower than the thermal diffusion length. Low transverse order Gaussian beams …

Large‐Amplitude Mountain Waves In The Mesosphere Observed On 21 June 2014 During Deepwave: 2. Nonlinear Dynamics, Wave Breaking, And Instabilities, David C. Fritts, Ling Wang, Michael J. Taylor, Pierre-Dominique Pautet, Neal R. Criddle, Bernd Kaifler, Stephen D. Eckermann, Ben Liley

Publications

Weak cross‐mountain flow over the New Zealand South Island on 21 June 2014 during the Deep Propagating Gravity Wave Experiment (DEEPWAVE) led to large‐amplitude mountain waves in the mesosphere and lower thermosphere. The mesosphere and lower thermosphere responses were observed by ground‐based instruments in the lee of the Southern Alps supporting DEEPWAVE, including an Advanced Mesosphere Temperature Mapper, a Rayleigh lidar, an All‐Sky Imager, and a Fabry‐Perot Interferometer. The character of the mountain wave responses at horizontal scales of ~30–90 km reveals strong “sawtooth” variations in the temperature field suggesting large vertical and horizontal displacements leading to mountain wave overturning. …

Marine Invertebrates: Communities At Risk, Jennifer A. Mather

Jennifer Mather, PhD

Our definition of the word ‘animal’ centers on vertebrates, yet 99% of the animals on the planet are invertebrates, about which we know little. In addition, although the Census of Marine Life (COML.org) has recently conducted an extensive audit of marine ecosystems, we still do not understand much about the animals of the seas. Surveys of the best-known ecosystems, in which invertebrate populations often play a key role, show that the invertebrate populations are affected by human impact. Coral animals are the foundation of coral reef systems, which are estimated to contain 30% of the species in the ocean. Physical …

Degree And Neighborhood Conditions For Hamiltonicity Of Claw-Free Graphs, Zhi-Hong Chen

Zhi-Hong Chen

For a graph H , let σ t ( H ) = min { Σ i = 1 t d H ( v i ) | { v 1 , v 2 , … , v t } is an independent set in H } and let U t ( H ) = min { | ⋃ i = 1 t N H ( v i ) | | { v 1 , v 2 , ⋯ , v t } is an independent set in H } . We show that for a given number ϵ and given integers …

Circumferences Of 3-Connected Claw-Free Graphs, Ii, Zhi-Hong Chen

Zhi-Hong Chen

For a graph H , the circumference of H , denoted by c ( H ) , is the length of a longest cycle in H . It is proved in Chen (2016) that if H is a 3-connected claw-free graph of order n with δ ≥ 8 , then c ( H ) ≥ min { 9 δ − 3 , n } . In Li (2006), Li conjectured that every 3-connected k -regular claw-free graph H of order n has c ( H ) ≥ min { 10 k − 4 , n } . Later, Li posed …

New Algorithms For Computing Field Of Vision Over 2d Grids, Evan Debenham

Electronic Thesis and Dissertation Repository

In many computer games checking whether one object is visible from another is very important. Field of Vision (FOV) refers to the set of locations that are visible from a specific position in a scene of a computer game. Once computed, an FOV can be used to quickly determine the visibility of multiple objects from a given position.

This thesis summarizes existing algorithms for FOV computation, describes their limitations, and presents new algorithms which aim to address these limitations. We first present an algorithm which makes use of spatial data structures in a way which is new for FOV calculation. …

Synthesis And Characterization Of Peptide Nucleic Acids Incorporating Modified Nucleobases, Ali Heidari

Electronic Thesis and Dissertation Repository

Peptide Nucleic Acid (PNA), is a mimic of natural nucleic acids with exceptional binding properties. As such, numerous applications in biochemistry, medicine and biotechnology for PNA exist or have been proposed so far. Pseudo-complementary PNAs containing diaminopurine and thiouracil base pairs have been prepared and are shown to bind with high specificity and efficiency to complementary targets in double-stranded DNA by a mechanism termed ‘‘double duplex invasion’’ in which the duplex is unwound and both DNA strands are targeted simultaneously, each by one of the two pseudo-complementary PNAs. Chapter 2 describes a method for the preparation of modified nucleic acids …

Deep Machine Learning Techniques For The Detection And Classification Of Sperm Whale Bioacoustics, Peter C. Bermant, Michael M. Bronstein, Robert J. Wood, Shane Gero, David F. Gruber

Publications and Research

We implemented Machine Learning (ML) techniques to advance the study of sperm whale (Physeter macrocephalus) bioacoustics. This entailed employing Convolutional Neural Networks (CNNs) to construct an echolocation click detector designed to classify spectrograms generated from sperm whale acoustic data according to the presence or absence of a click. The click detector achieved 99.5% accuracy in classifying 650 spectrograms. The successful application of CNNs to clicks reveals the potential of future studies to train CNN-based architectures to extract finer-scale details from cetacean spectrograms. Long short-term memory and gated recurrent unit recurrent neural networks were trained to perform classification tasks, including (1) …

Animal Research, Accountability, Openness And Public Engagement: Report From An International Expert Forum, Elisabeth H. Ormandy, Daniel M. Weary, Katarina Cvek, Mark Fisher, Kathrin Herrmann, Pru Hobson-West, Michael Mcdonald, William Milsom, Margaret Rose, Andrew Rowan, Joanne Zurlo, Marina A.G. Von Keyserlingk

Oversight of Animal Experimentation Collection

In November 2013, a group of international experts in animal research policy (n = 11) gathered in Vancouver, Canada, to discuss openness and accountability in animal research. The primary objective was to bring together participants from various jurisdictions (United States, Sweden, Australia, New Zealand, Germany, Canada and the United Kingdom) to share practices regarding the governance of animals used in research, testing and education, with emphasis on the governance process followed, the methods of community engagement, and the balance of openness versus confidentiality. During the forum, participants came to a broad consensus on the need for: (a) evidence-based metrics to …

An Analysis Of The Potential Toxicological Effects Of Marine Plastics And Associated Organic And Inorganic Toxic Compounds On Six Commercially Significant Fishery Species, Nicole Marie Jackson

HCNSO Student Capstones

Marine plastics are a global issue which has garnered significant support for mitigation efforts in recent history. Research on the prevalence of plastic polymers in the marine environment has also come to the forefront of the scientific community, however studies on the toxicological impacts of their presence remains to be a little studied matter to date. In this study an intensive critical review of existing data was conducted to compile profiles (including: stability ranks, sorption capacities, organic and inorganic toxic constituent concentrations, bioaccumulations scores per constituent, biomagnification scores per constituent, and totaled threat scores out of five) for the three …

Correlations Between Short- And Long-Time Relaxation In Colloidal Supercooled Liquids And Glasses, Chandan K. Mishra, Xiaoguang Ma, Piotr Habdas, Kevin B. Aptowicz, A. G. Yodh

Physics & Engineering Faculty Publications

Spatiotemporal dynamics of short- and long-time structural relaxation are measured experimentally as a function of packing fraction, φ, in quasi-two-dimensional colloidal supercooled liquids and glasses. The relaxation times associated with long-time dynamic heterogeneity and short-time intracage motion are found to be strongly correlated and to grow by orders of magnitude with increasing φ toward dynamic arrest. We find that clusters of fast particles on the two timescales often overlap, and, interestingly, the distribution of minimum-spatial-separation between closest nonoverlapping clusters across the two timescales is revealed to be exponential with a decay length that increases with φ. In total, the experimental …

Collaborative Research: Development And Application Of A Framework For Integrated Geodynamic Earth Models, Anthony Lowry

Funded Research Records

No abstract provided.

Why Weightlifters Grunt: A Classroom Exercise That Introduces Students To Evolution, H. Charles Romesburg

Environment and Society Faculty Publications

A classroom exercise is described in which college students take part in creating and supporting an evolutionary hypothesis that explains effort grunting. The exercise holds their interest throughout and readies them to understand hypotheses of animal and plant evolution. It informs them about the dependence of cultural evolution upon biological evolution, and it connects widely to curricula.

Life's Passion For Odu Alum Is To Be "Water's Voice", Joe Garvey

News Items

No abstract provided.

A Mathematical Model For The Effect Of Domestic Animals On Human African Trypanosomiasis (Sleeping Sickness), Sagi Shaier, Meghan Burke

The Kennesaw Journal of Undergraduate Research

Human African Trypanosomiasis (HAT) is a parasite infection that is spread by the bites of tsetse flies and it is almost 100% fatal if left untreated (World Health Organization, “Neglected”). Our hypothesis is that by adding domestic animals to areas where humans are found (villages and plantations), we can reduce the amount of biting on humans, and therefore reduce the rate at which humans become infected. Numerical simulations supported our hypothesis, showing that increasing the number of domestic animals (pigs in our model) slows down the spread of the disease in both humans and domestic animals.

Editorial: Machine Learning In Biomolecular Simulations, Gennady M. Verkhivker, Vojtech Spiwok, Francesco Luigi Gervasio

Mathematics, Physics, and Computer Science Faculty Articles and Research

"Interest in machine learning is growing in all fields of science, industry, and business. This interest was not primarily initiated by new theoretical findings. Interestingly, the theoretical basis of the majority of machine learning techniques, such as artificial neural networks, decision trees, or kernel methods, have been known for a relatively long time. Instead, there are other effects that triggered the recent boom of machine learning."

Annual And Seasonal Variation In Hydrologic Performance Of Ecoroofs Of Multiple Depths, Portland, Or, Ashley Michelle Baker

Dissertations and Theses

It is essential that cities adopt new approaches to stormwater management in the face of changing precipitation regime. In some locations, ecoroofs have been incorporated into city plans as a stormwater control measure, and thus their real-world performance under current conditions can assist with adequate planning. In this study rainfall retention data collected during a three year period, between 2014-2017, is analyzed for 75mm and 125mm ecoroof plots in Portland, Oregon, USA. There is no difference in annual rainfall retention performance between the shallower and deeper plots. However, the 36% mean annual retention of the ecoroof plots is a significant …

Extraction Of Form Factors From A Four-Dimensional Angular Analysis B̅ →D∗ℓ−V̅ ℓ, J. P. Lees, V. Poireau, V. Tisserand, E. Grauges, A. Palano, G. Eigen, D. N. Brown, Yu G. Kolomensky, M. Fritsch, H. Koch, T. Schroeder, C. Hearty, T. S. Mattison, J. A. Mckenna, R. Y. So, V. E. Blinov, A. R. Buzykaev, V. P. Druzhinin, Milind Purohit, Et. Al.

Faculty Publications

An angular analysis of the decay B̅ → D ∗ ℓ − v̅ ℓ , ℓ ∈ { e , μ } , is reported using the full e ⁺e⁻ collision data set collected by the BABAR experiment at the Υ (4S) resonance. One B meson from the Υ (4S) → B B̅ decay is fully reconstructed in a hadronic decay mode, which constrains the kinematics and provides a determination of the neutrino momentum vector. The kinematics of the semileptonic decay is described by the dilepton mass squared, q² , and three …

Acute Toxicity Testing Without Animals: More Scientific And Less Of A Gamble, Gillian R. Langley

Gill Langley, PhD

In this report, we argue specifically that acute toxicity data should not be sought from animal tests. The underlying principle of such tests on rats and mice is that the results can be effectively extrapolated to humans. In fact, after nearly 80 years of use of these tests, the predictivity of rodent data for human acute toxic effects has been disputed but never proven.

The Effect Of Spatial Averaging On Db/Dt Exposure Values For Implanted Medical Devices, Christopher Ap Brown

Electronic Thesis and Dissertation Repository

Magnetic resonance imaging (MRI) is a medical imaging modality that has seen continuous growth in the decades since its introduction. In conjunction with this increase in the use of MRI, there has also been a growth in the number of patients having implanted medical devices, such as pacemakers. These devices can have undesirable interactions with the MR system. The safety of these interactions must be guaranteed while ensuring that safety limits are not so conservative that they would preclude too many patients from benefiting from MRI. One factor that could make limits less restrictive is spatial averaging of the fields …

Emergence Of Tissue-Like Mechanics From Fibrous Networks Confined By Close-Packed Cells, Anne Van Oosten, Xingyu Chen, Likang Chin, Katrina Cruz, Alison E. Patteson, Katarzyna Pogoda, Vivek B. Shenoy, Paul A. Janmey

Physics - All Scholarship

The viscoelasticity of the crosslinked semiflexible polymer networks—such as the internal cytoskeleton and the extracellular matrix—that provide shape and mechanical resistance against deformation is assumed to dominate tissue mechanics. However, the mechanical responses of soft tissues and semiflexible polymer gels differ in many respects. Tissues stiffen in compression but not in extension1,2,3,4,5, whereas semiflexible polymer networks soften in compression and stiffen in extension6,7. In shear deformation, semiflexible polymer gels stiffen with increasing strain, but tissues do not1,2,3,4,5 …

Solving Differential Matrix Equations For Surface With Respect To Action Of Group Of Lorence, U. Bekbayeva, K. Muminov

Scientific journal of the Fergana State University

In The artlcle a description is given for the system of differential matrix equations, the solutions of which regenerate the class of surfaces in 4 – dimensional space, which are equivalent with respect to the action of group - O(3,1).

Sorption Of Copper (Ii), Nickel (Ii) And Cobalt (Ii) Ions Into The Ionite Modified By Polyphinylchloride And Polyethylene Polyamine, Kh Ismoilova, D Bekchanov, Sh Khasanov, M Baltaeva

Scientific journal of the Fergana State University

IPolyphinylchloride was modified by polyethylene polyamine, and the ionites were studied in static conditions by the artificial solution of copper (II), nickel (II) and cobalt (II) ions. In static conditions, factors affecting the sorption process, such as time, temperature and concentration dependence were investigated. The results of the inquiry process were studied by IR analysis

Tricomi Type Problem For Mixed Type Equation With Sub-Diffusion And Wave Equation, E. Karimov, S. Kerbal

Scientific journal of the Fergana State University

In this paper, we have considered a Tricomi type problem for mixed type equation with Hilfer’s double order derivative sub-diffusion equation and classical wave equation in a composite domain. Main methods of the investigation are a method of integral equations and energy integrals’ method.