Digital Commons Network^™

Collapse Of The Bindschadler Ice Stream At 11.5 Cal Kyr Bp Via Marine Ice Cliff Instability, Anna Sivils

LSU Master's Theses

Previous studies of the Whales Deep Basin (WDB) outer continental shelf showed that the paleo-ice shelf fronting the Bindschadler Ice Stream broke up at 12.3 cal kyr BP. A calving cliff was subsequently maintained until at least 11.5 cal kyr BP. Slightly after that time, the grounding line rapidly retreated creating a 200 km embayment of grounded ice over the foredeepened middle continental shelf. The rapid opening of the embayment is recorded by a backstepping succession of small-scale morainal ridges on the middle continental shelf. The overlapping and end-to-end spacing of morainal ridges requires that the retreating grounding line experienced …

First-Principles Simulations Of Attosecond Transient X-Ray Absorption, Min Chen

LSU Doctoral Dissertations

The first part of this dissertation presents calculations of the extinction spec- tra of gold-silver/silver-gold core-shell nanospheres. The goal of this projectsis to get a deeper understanding of surface plasmonic resonance in metal nanospheres with core-shell geometry. Here, we used the finite-difference time-domain (FDTD) method and total-field/scattered-field (TFSF) framework to compute the extinction spectra of nanoparticles to determine the geometry of gold-silver/silver-gold core-shell nanoparticles. This supported experimental work on monitoring the growth dynamics of colloidal gold- silver/silver-gold core-shell nanoparticles using in situ second harmonic generation (SHG) and extinction spectroscopy.

The second and main project involved simulating attosecond transient spectra for …

The Case For Succession Planning In Higher Education: A Study Of Knowledge Transfer Within Louisiana State University, Leila Shaik Villien

LSU Doctoral Dissertations

The primary purpose of this study was to explore the challenges, benefits, and perceptions of succession planning among currently employed administrators at research universities in the southern portion of the United States at the level of assistant department head or higher and the accessible population was defined as currently employed administrators at Louisiana State University at the level of assistant department head or higher. Deans, Associate Deans, Department Heads, Assistant Department Heads, and Department Chairs were invited to participate in an online survey designed by the researcher to assess the attitude toward succession planning and training, along with a variety …

Integrating Behavioral Research Findings With A Liberal Arts Paradigm, Jonathan Peterson

LSU Master's Theses

This paper explores the role of behavioral research in understanding the complexity and relevance of creativity. A brief history of the liberal arts and its current application is followed by a discussion of the importance of variability in generating novel and diverse responses, challenging the notion that creativity is solely a product of innate talent. The effects of reinforcement on variability, and how it relates to a complex relationship between reinforcement and the probability of variable responding leads to a discussion of how the combination of previously trained behaviors can lead to creative problem-solving, emphasizing the role of combinatory behavior …

Advancements In Middle School Agricultural Education: An Examination Of Emerging Trends And Exemplary Programs, Jacob P. Englin

LSU Master's Theses

Recent trends in agricultural education have demonstrated that the number of middle school programs and students has been increasing. Despite this, middle school agricultural education students, teachers, and programs often have been considered to be underserved. For example, teachers at this level have expressed that they often lacked the training and resources to meet the needs of this diverse learning population. Even so, middle school agricultural education teachers have continued to provide quality learning experiences for their students. In response, this investigation’s purpose was to examine current trends of middle school agricultural education and the quality of learning conducted by …

Susceptibility Of Spodoptera Frugiperda Populations In The Southern Region Of The U.S. To Common Bt Proteins And Performance Of A Dual-Gene Resistant Helicoverpa Zea Strain On Common Pyramided Bt Corn Traits, Tiago H. Da Silva

LSU Master's Theses

The fall armyworm (Spodoptera frugiperda) and corn earworm (Helicoverpa zea) are two polyphagous pests that, in the Americas, are targeted by transgenic corn and cotton expressing Bacillus thuringiensis (Bt) proteins. A previous study during 2011-2013 demonstrated practical resistance to Cry1F corn in S. frugiperda in the southeastern seaboard of the U.S., while resistance of H. zea to Bt corn and cotton containing cry1A and cry2A genes has widely occurred in the U.S. The first objective of this study was to investigate the current susceptibility status to four Bt proteins commonly expressed in Bt corn plants, including …

Entanglement In The Hawking Effect: From Astrophysical To Optical Black Holes, Dimitrios Kranas

LSU Doctoral Dissertations

The Hawking effect is an exciting physical prediction lying at the intersection of the two most successful theories of the past century, namely, Einstein’s theory of relativity and quantum mechanics. In this dissertation, we put special emphasis on the quantum aspects of the Hawking process encoded in the entanglement shared by the emitted fluxes of created quanta. In particular, we employ sharp tools from quantum information theory to quantify the entanglement produced by the Hawking effect throughout the black hole evaporation process. Our framework allows us to extend previous calculations of entanglement to a larger set of cases, for instance, …

Characterizing Wind-Wave Flow Physics And Loading Effects On Power Transmission Systems And Offshore Wind Turbines, Tianqi Ma

LSU Doctoral Dissertations

Recent extreme hurricanes caused extensive damage to critical civil infrastructure. Accurate modeling of the extreme complex wind fields and coupled wind-wave fields is essential to quantify the single wind or combined wind-wave loading effects on the structures. This research aims to characterize wind and wind-wave flow physics to quantify the loading effect on power transmission systems and offshore wind turbines.

First, a microscale (∼km) high-fidelity high-resolution computational model is developed to simulate hurricane wind fields with detailed physics. The generated wind field is applied to analyze the structural response of a power transmission system. The proposed hurricane boundary layer (HBL) …

Interactive Effects Of The Partial Pressure Of Co2, Temperature, And Nutrient-Limitation On The Physiology And Growth Of The Coccolithophore E. Huxleyi Grown On A 12:12 L:D Cycle Of Illumination, James Bradley

LSU Master's Theses

I studied the interactive effects of pCO2, temperature, and nutrient limitation on the growth and physiology of the marine coccolithophore, Emiliania huxleyi. This was done to look at the effect of climate change factors on the widespread and abundant calcifying marine organism as a predictor of what the future has to hold. The strain of E. huxleyi (PnB 272 B10) was grown on a 12:12 L:D cycle of illumination and exposed to either high or low pCO2 under nutrient-replete or nitrate-limited conditions across a temperature range of 10–28C. I examined the direct and interactive effects of temperature, pCO2, and nutrient …

Some New Techniques And Their Applications In The Theory Of Distributions, Kevin Kellinsky-Gonzalez

LSU Doctoral Dissertations

This dissertation is a compilation of three articles in the theory of distributions. Each essay focuses on a different technique or concept related to distributions.

The focus of the first essay is the concept of distributional point values. Distribu- tions are sometimes called generalized functions, as they share many similarities with ordi- nary functions, with some key differences. Distributional point values, among other things, demonstrate that distributions are even more akin to ordinary functions than one might think.

The second essay concentrates on two major topics in analysis, namely asymptotic expansions and the concept of moments. There are many variations …

Effects Of Coastal Freshening On Porewater Salinity And Nitrogen Cycling In Brackish Marsh Soils: Implications For Biogeochemical Resilience In Barataria Basin, La, Robert C. Feder

LSU Master's Theses

The Mid-Barataria Sediment Diversion will divert sediments and fresh water from the Mississippi River into mid-Barataria Basin, LA for the purposes of building and sustaining coastal marshes, potentially reducing the estuarine salinity to 0 during operation. Increased freshwater inputs to the area of project influence may reduce porewater salinity and induce ammonium adsorption in brackish marsh soils of the region, potentially impacting the activity of ammonium-producing and denitrifying bacteria. However, brackish soils occur in zones of intermediate salinity and may, therefore, exhibit biogeochemical resilience to episodic changes in surface water salinity. I hypothesized that inundating brackish marsh soils with fresh …

A Systematic Literature Review Of Cleanroom Ventilation And Air Distribution Systems, Arup Bhattacharya, Mohammad Saleh Nikoopayan Tak, Shervin Shoai-Naini, Fred Betz, Ehsan Mousavi

Faculty Publications

Cleanroom ventilation systems are well-established; however, the advantages and limitations of current practices need to be examined and explained further. This study begins by looking over the history of cleanroom ventilation systems that creates the basis for understanding ventilation rate specifications, terminologies employed in ventilation effectiveness, and recognizing scientific studies that correlate ventilation effectiveness with air change rates. This systematic review includes a comprehensive summary that contains a set of historical data and evidence that may be used to specify ventilation requirements in cleanrooms. Scientific articles are classified in terms of laboratory experiments, simulations/numerical analysis, or hybrid. HVAC designers and …

Review Of Heaven & Earth Grocery, Michael F. Russo

Faculty Publications

No abstract provided.

Extended Sentinel Monitoring Of Helicoverpa Zea Resistance To Cry And Vip3aa Toxins In Bt Sweet Corn: Assessing Changes In Phenotypic And Allele Frequencies Of Resistance, Galen P. Dively, Tom P. Kuhar, Sally V. Taylor, Helene Doughty, Kristian Holmstrom, Daniel O. Gilrein, Brian A. Nault, Joseph Ingerson-Mahar, Anders Huseth, Dominic Reisig, Shelby Fleischer, David Owens, Kelley Tilmon, Francis Reay-Jones, Pat Porter, Jocelyn Smith, Julien Saguez, Jason Wells, Caitlin Congdon, Holly Byker, Bryan Jensen, Chris Difonzo, William D. Hutchison, Eric Burkness, Robert Wright, Michael Crossley, Heather Darby, Tom Bilbo, Nicholas Seiter, Christian Krupke, Craig Abel, Brad S. Coates, Bradley Mcmanus

Faculty Publications

Transgenic corn and cotton that produce Cry and Vip3Aa toxins derived from Bacillus thuringiensis (Bt) are widely planted in the United States to control lepidopteran pests. The sustainability of these Bt crops is threatened because the corn earworm/bollworm, Helicoverpa zea (Boddie), is evolving a resistance to these toxins. Using Bt sweet corn as a sentinel plant to monitor the evolution of resistance, collaborators established 146 trials in twenty-five states and five Canadian provinces during 2020–2022. The study evaluated overall changes in the phenotypic frequency of resistance (the ratio of larval densities in Bt ears relative to densities in non-Bt ears) …

Exploring Barriers To Sars-Cov-2 Testing Uptake In Underserved Black Communities In Louisiana, Peter T. Katzmarzyk, Candice A. Myers, Michelle R. Nelson, Kara D. Denstel, Emily F. Mire, Robert L. Newton, Stephanie T. Broyles, John P. Kirwan

Division of Basic Science Faculty Publications

Objective: To collect qualitative data on approaches that can potentially reduce barriers to, and create strategies for, increasing SARS-CoV-2 testing uptake in underserved Black communities in Louisiana. Methods: A series of eight focus groups, including 41 participants, were conducted in primarily Black communities. The Nominal Group Technique (NGT) was used to determine perceptions of COVID-19 as a disease, access to testing, and barriers limiting testing uptake. Results: Common barriers to SARS-CoV-2 testing were identified as lack of transportation, misinformation/lack of information, lack of time/long wait times, fear of the test being uncomfortable and/or testing positive, the cost of testing, and …

Simulation Of Radioactive Plume Transport In The Atmosphere Including Dynamics Of Particle Aggregation And Breakup, Alexander I. Wiechert, Austin P. Ladshaw, Yong Ha Kim, Costas Tsouris, Sotira Yiacoumi

Faculty Publications

Accurate prediction of the atmospheric transport of debris particles relies heavily on our knowledge of the size distribution of the particles within a debris cloud. Assuming a fixed particle size during simulations is not always viable since the size distribution of the debris can change during transport. Various microphysical processes, such as aggregation and breakup, influence debris particles and dictate any changes to the size distribution. To track those changes that can occur, a population balance model can be adopted and instituted within a model framework. Nonetheless, many of the models that simulate the transport of radioactive debris following a …

Measuring Resilience To Sea-Level Rise For Critical Infrastructure Systems: Leveraging Leading Indicators, Lamis Amer, Murat Erkoc, Rusty A. Feagin, Sabarethinam Kameshwar, Katharine J. Mach, Diana Mitsova

Faculty Publications

There has been a growing interest in research on how to define and build indicators of resilience to address challenges associated with sea-level rise. Most of the proposed methods rely on lagging indicators constructed based on the historical performance of an infrastructure sub-system. These indicators are traditionally utilized to build curves that describe the past response of the sub-system to stressors; these curves are then used to predict the future resilience of the sub-system to hypothesized events. However, there is now a growing concern that this approach cannot provide the best insights for adaptive decision-making across the broader context of …

Flammability Properties Of The Pyrolysis Gas Generated From Willow Wood, Maria Mitu, Domnina Razus, Dorin Boldor, Cosmin Marculescu

Faculty Publications

Willow wood presents a real interest for biomass pyrolysis due to its fast growth, renewability, and high energy density. Following the pyrolysis of willow wood in an inert atmosphere, a multi-fuel gaseous mixture was obtained, with the following composition (by volume): 38.20% CO/21.87% H2/17.44% CH4/1.15% O2/17.15% CO2/4.19% N2. The propagation of laminar premixed flames in these multifuel mixtures with air was investigated numerically for initial temperatures from 298 to 500 K, initial pressures from 1 to 20 bar, and fuel equivalence ratios between 0.60 and 2.00. The combustion of these gaseous mixtures as free laminar premixed flames was simulated by …

Toward One Health: A Spatial Indicator System To Model The Facilitation Of The Spread Of Zoonotic Diseases, Daniel Jato-Espino, Fernando Mayor-Vitoria, Vanessa Moscardó, Fabio Capra-Ribeiro, Leticia Bartolome Del Pino

Faculty Publications

Recurrent outbreaks of zoonotic infectious diseases highlight the importance of considering the interconnections between human, animal, and environmental health in disease prevention and control. This has given rise to the concept of One Health, which recognizes the interconnectedness of between human and animal health within their ecosystems. As a contribution to the One Health approach, this study aims to develop an indicator system to model the facilitation of the spread of zoonotic diseases. Initially, a literature review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement to identify relevant indicators related to One Health. The …

Rethinking Attention Control: An Individual Differences Approach, Vincent A. Medina

LSU Doctoral Dissertations

While there is extensive literature on visual spatial attention, less is known about auditory spatial attention, especially in terms of attention control. There is also a growing literature highlighting the importance of considering individual differences in attention control ability. Given these points, the purpose of this study was twofold. The first was to understand how auditory attention control is influenced by spatial location as well as vision. The second was to examine whether individual differences in attention control ability can predict task performance in that context. We utilized two tasks for these purposes. Experiment 1a consisted of a cross-modal Stroop …

A Performer's Guide To Two Song Collections: “Mementos Of Innocence” And “Three Yeats Songs” By Malaysian Composer Chee Yean Wong, Wu Ji Khoo

LSU Doctoral Dissertations

Despite the flourishing existence of Asian Art Music for over half a century, relatively little has been done to advance its recognition and prominence. Through this project, the author hopes to shed light on the beauty and richness of Asian Art Music and encourage its inclusion in the repertoire of American classical music. The purpose of this document is to supply a comprehensive performer’s guide to Malaysian composer, Chee Yean Wong’s song collections: “Mementos of Innocence” and “Three Yeats Songs.” The collections feature settings of English poems by Jean Blewett, Christina Rossetti, Edwin C. Ranck, Rabindranath Tagore, and William Butler …

Adaptive Quantum Information Processing In Non-Equilibrium Environments, Arshag Danageozian

LSU Doctoral Dissertations

Solid state and condensed matter systems, such as diamond impurities, superconductors, quantum dots, and ion traps, constitute important physical platforms for various applications in quantum information processing (QIP). However, it has consistently been shown that all such modern platforms suffer from non-equilibrium behavior on timescales that are relevant for many important QIP tasks. The causes range from intrinsic non-equilibrium dynamics (e.g. in diamond) to the presence of various impurities with their own internal dynamics (e.g. in superconductors and quantum dots) or variations in the control fields used to stabilize the quantum matter (e.g. in ion traps). When reserving degrees of …

Phase Transitions And Magnetocaloric Effects In Metastable Phases Of Intermetallic Compounds, Tej Bahadur Poudel Chhetri

LSU Doctoral Dissertations

The interplay between spin and lattice degrees of freedom in magnetic materials often results in interesting magnetoresponsive effects. The magnetocaloric effect is one such magnetothermal phenomenon that may be utilized in energy-efficient magnetic cooling systems. This effect becomes more prominent near a coupling of magnetic and structural transitions, i.e., magnetostructural transitions (MSTs). This dissertation investigates phase transitions (magnetic and structural) in metastable phases of MnNiGe- and MnCoGe-based compounds generated through high-pressure synthesis/annealing and thermal quenching techniques and assesses their magnetocaloric effects.

First, the effects of doping, hydrostatic pressure, and thermal quenching on phase transitions and related magnetocaloric effects in Mn …

Multiplication Operators By White Noise Delta Functions And Associated Differential Equations, Luigi Accardi, Un Cig Ji, Kimiaki Saitô

Journal of Stochastic Analysis

No abstract provided.

Determining Ion Activity Coefficients In Ion-Exchange Membranes With Machine Learning And Molecular Dynamics Simulations, Hishara Keshani Gallage Dona, Teslim Olayiwola, Luis A. Briceno-Mena, Christopher G. Arges, Revati Kumar, Jose A. Romagnoli

Faculty Publications

The activity coefficients of ions in polymeric ion-exchange membranes (IEMs) dictate the equilibrium partitioning coefficient of the ions between the membrane and the liquid. It also affects ion transport processes, such as conductivity, in ion-exchange membranes. Accurately predicting the ion activity coefficient without experimental data has been elusive as most models are empirical or semi-empirical. This work employs an embedding process that maps microscopic and macroscopic properties for modeling of ion activity coefficients in IEMs with molecular dynamics (MD) and machine learning (ML). This strategy is effective for accurately predicting activity coefficients in various IEM materials, including random copolymer and …

Algorithm 1035: A Gradient-Based Implementation Of The Polyhedral Active Set Algorithm, William W. Hager, Hongchao Zhang

Faculty Publications

The Polyhedral Active Set Algorithm (PASA) is designed to optimize a general nonlinear function over a polyhedron. Phase one of the algorithm is a nonmonotone gradient projection algorithm, while phase two is an active set algorithm that explores faces of the constraint polyhedron. A gradient-based implementation is presented, where a projected version of the conjugate gradient algorithm is employed in phase two. Asymptotically, only phase two is performed. Comparisons are given with IPOPT using polyhedral-constrained problems from CUTEst and the Maros/Meszaros quadratic programming test set.

Random Variables With Overlapping Number And Weyl Algebras Ii, Ruma Dutta, Gabriela Popa, Aurel Stan

Journal of Stochastic Analysis

No abstract provided.

Simulations Of Intruder-Free X-Ray Transient Absorption And Time-Resolved X-Ray Scattering For Probing Attosecond Electron Dynamics, Mengqi Yang

LSU Doctoral Dissertations

The motion of electrons plays a fundamental role in both physics and chemistry, and capturing such dynamics requires the ability to resolve changes at the attosecond timescale, which is enabled by the advent of ultrashort laser pulses. This dissertation aims to facilitate the interpretation of ultrafast electron dynamics and attosecond spectroscopy by real-time time-dependent density functional theory (RT-TDDFT) simulations. The first part of this dissertation focuses on improving the simulation of X-ray transient absorption spectra (XTAS) with Gaussian basis sets in RT-TDDFT by applying a filter to the transition dipole matrix. Due to the spatial limitation of atom-centered Gaussian functions, …

Cycles And Dynamic Correlations Between Agricultural And Stock Markets, Junior E. Betanco Gunera

LSU Master's Theses

This study conducts two interrelated econometric analyses; it first analyzes the cyclical relationship between stock and commodity markets and second, it studies the dynamic conditional correlation between them. The cyclical analysis uses the bandpass filter proposed by Christiano-Fitzgerald (2003) to isolate the trend component in the long-run relationship of stocks relative to commodity markets. The results show that stock and commodities have alternated in return leadership nine times during the last 151 years, three full cycles (from peak to peak) can be clearly identified, each one with an average duration of 31 years. While the COVID-19 pandemic had little impact …

Sedimentary Processes And Instability On The Mississippi River Delta Front Near The Wreck Of The Ss Virginia, Nathan Figueredo

LSU Doctoral Dissertations

Multi-cores and piston cores were collected seaward of the Mississippi River Delta’s Southwest Pass at ~80 m water depth in 2017 to better understand sedimentary characteristics and processes on the Mississippi River Delta Front (MRDF) in the vicinity of the SS Virginia shipwreck, and to support marine archeological research. Core analyses were performed to inform our understanding of the dynamics of sediment motion in the study area through radionuclide activity (²¹⁰Pb and ¹³⁷Cs), volume frequency of grain size, bulk density, and fabric (X-Radiography). Sediment accumulation rates (SAR), calculated from multi-core ²¹⁰Pb activity are 0.22 - 0.29 …