Digital Commons Network^™

Computational Nanoscale Investigations Of Structure, Dynamics, And Reactivity At Solid–Liquid Interfaces, Golam Azom

LSU Doctoral Dissertations

Interfaces where two or more condensed phases meet govern phenomena central to catalysis, electrochemical energy conversion, separations, and environmental remediation. Their structural heterogeneity and dynamic nature make them challenging to probe experimentally, but computer simulations provide molecular-level insights into processes that remain inaccessible to experiments. This dissertation employs ab initio molecular dynamics (AIMD), classical molecular dynamics, and machine-learned interatomic potentials to investigate the structure, dynamics, and proton transport at graphene oxide (GO)–liquid interfaces.

The first project explores aqueous GO interfaces across a spectrum of oxidation states that extends from highly oxidized sheets to fully reduced graphene. Deep neural network force …

Functional Cellulose Nanomaterials In Value-Added Applications, Mohammad Shayan

LSU Doctoral Dissertations

Cellulose nanomaterials (CNMs), including cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs), offer potential value-added applications. This dissertation explores their versatility through three applications. In the first application, CNCs and CNFs were combined to create a pH-sensitive film by immobilizing anthocyanins from red cabbage extract (RCE). The addition of RCE altered the suspension's rheological, optical, and mechanical properties, with films containing 30 wt.% RCE exhibiting optimal performance and rapid pH responsiveness for seafood packaging. The second application addressed zinc dendrite growth and short circuits in aqueous zinc-ion batteries (ZIBs) by fabricating a hybrid NFC/Al(OH)₃ /PTFE protective layer for zinc anodes. …

Modeling Nutrient Functions: Strengthening The Reliability And Applicability Of Ecosystem Service Models For Land Use Decision-Making, Mariam Gabriela Valladares Castellanos

LSU Doctoral Dissertations

Effective water quality management requires a clear understanding of both the magnitude and spatial distribution of nutrient retention and export across dynamic landscapes, given their direct implications for drinking water supply, ecosystem integrity, fisheries, and recreational uses. Equally important is anticipating trade-offs from management actions, which can alter ecosystem functioning and the flow of services. Modeling tools provide a means to predict nutrient outcomes, evaluate these trade-offs, and support decision-making; however, their utility is often constrained by persistent challenges, including model uncertainty, limited applicability in data-scarce regions, and insufficient empirical foundations to inform scenario-driven decision-making. This dissertation addresses these gaps …

User Privacy In The Digital Playground: An In-Depth Investigation Of Facebook Instant Games, Sideeq Bello

LSU Master's Theses

Amid growing concerns over data privacy in web and mobile applications, this study aims to assess the privacy mechanisms in instant games on Facebook, a platform with approximately 3.03 billion monthly active users and a substantial repository of personal data. Instant Games have become increasingly popular due to their ease of access and social integration features. Investigating these games can provide insights into privacy mechanisms and practices, thereby informing the development of more fair, compliant, and user privacy-centric gaming experiences. Thus, this study proposes an integrated analytical framework that leverages a combination of descriptive, memory, and network analysis techniques to …

Sustainable Robotic Construction: A Computational Particle Packing Approach For The Development Of Sustainable, Low-Cement 3d Printable Materials, Aranya Aumit Paul

LSU Master's Theses

Construction 3D Printing (C3DP) holds great potential for automated construction but faces key challenges, including the high Portland cement content of its printing materials. The high cement content raises material costs, causes shrinkage and thermal cracking, and increases its carbon footprint. This study introduces a novel hybrid computational pipeline that combines image based automated gradation analysis with 2D stochastic particle packing simulation, to design low-cement printable materials with minimal experimental testing. The image-based gradation system achieved a mean absolute error under 3.64% across six fine and coarse aggregate types. The particle packing simulation demonstrated an average error of less than …

Navigating New Technology: A Phenomenological Study Into Technology Coaches’ Experiences During Ai Expansion In Schools, Elizabeth K. Wrzesinski

LSU Doctoral Dissertations

Artificial intelligence (AI) is rapidly influencing instructional practices in K–12 education, yet most states have not issued clear, binding policies to guide its integration. As a result, local school systems and support staff must interpret emerging guidance and determine how AI should be used in classrooms. This study examined how system-level technology coaches in the Deep South experience and support AI adoption in contexts where state guidance is advisory rather than mandatory. This qualitative phenomenological study used questionnaires and semi-structured interviews with technology coaches, and a content analysis of AI-related state and local policy guidance. Participants included technology coaches who …

Comparing The Consistency Between Age Estimations Across Various Three-Dimensional Model Creation Methods In An Attempt To Find A Practical Proxy For Physical Remains, Jeanne R. Wood

LSU Master's Theses

The purpose of this study is to determine whether digital three-dimensional models can serve as a viable alternative to physical human remains to allow continued research on fragile physical specimens. As digital three-dimensional models have become increasingly prevalent in anthropological and archaeological research, it is essential to assess their limitations and capabilities, particularly for subjective assessments that rely heavily on visual interpretation (Remondino & El-Hakim, 2006). While previous studies have focused on the use of digital three-dimensional models for quantitative measurements, their effectiveness for subjective analyses remains unclear (Cooper et al., 2003; Sholts et al., 2010; Stull et al., 2014; …

A Bdg Inequality For Stochastic Volterra Integrals, Alexandre Pannier

Journal of Stochastic Analysis

We establish Burkholder-Davis-Gundy-type inequalities for stochastic Volterra integrals with a completely monotone convolution kernel, which may exhibit singular behaviour at the origin. When the supremum is taken over a finite interval, the upper bound depends linearly on the Lγ-norm of the kernel, for any γ > 2. We demonstrate the utility of this inequality in quantifying the pathwise distance between two stochastic Volterra equations with distinct kernels, with a particular emphasis on the multifactor Markovian approximation. For kernels that decay sufficiently fast, we derive an alternative inequality valid over an infinite time interval, providing uniformin- time bounds for mean-reverting stochastic Volterra …

The Increase In Global Ocean Heat Content And Favorable Conditions For Tropical Cyclone And Cyclop Intensification: Accounting For El Niño, Robert Keenan Forney, Paul W. Miller, Travis A. Smith

Faculty Publications

The ocean heat content (“OHC”)—the heat energy within the ocean integrated to a reference depth—has physical drivers spanning spatial and temporal scales, including seasonality, the El Niño/Southern Oscillation (ENSO), and others. The present article investigates changes in the OHC100 during the period 1994–2020 using GLORYS12 monthly averaged ocean reanalysis. OHC100–ENSO correlation patterns are explored to glean insights about the oceanic mechanisms that facilitate the ENSO’s global teleconnections. After extracting known seasonality and ENSO signals using the Oceanic Niño Index (ONI), the OHC100 residual is analyzed to investigate multidecadal drivers of the OHC100. Lagged ENSO–OHC100 correlations (±12 months) reveal basin-scale oscillations …

Competition And Soil Microbe-Mediated Interactions Following Dieback Of A Dominant Wetland Plant, Joseph Johnston, Aaron E. Devries, Rodrigo Diaz, Vinson P. Doyle, Tracy Elsey-Quirk, James T. Cronin

Faculty Publications

Plant invasions can have important consequences for the soil ecosystem which, in turn, can affect interactions with other plant species and impose serious constraints on restoration efforts. In the Mississippi River Delta (MRD), USA, widespread dieback of the dominant wetland plant, Phragmites australis, was followed by the colonization of invasive Colocasia esculenta (taro) in many areas. We conducted a common-garden experiment to investigate the competitive interactions among taro and two P. australis lineages prevalent in the MRD, Delta and European invasive (EU), and the role of taro-soil microbes in mediating those interactions. Plant types were grown alone or together and …

Introducing A Markov Chain-Based Time Calibration Procedure For Multi-Channel Particle Detectors: Application To The Superfgd And Tof Detectors Of The T2k Experiment, S. Abe, H. Alarakia-Charles, I. Alekseev, C. Alt, T. Arai, T. Arihara, S. Arimoto, A. M. Artikov, Y. Awataguchi, N. Babu, V. Baranov, G. Barr, D. Barrow, L. Bartoszek, L. Bernardi, L. Berns, S. Bhattacharjee, A. V. Boikov, A. Blanchet, A. Blondel, A. Bonnemaison, S. Bordoni, M. H. Bui, T. H. Bui, F. Cadoux, S. Cap, A. Cauchois, J. Chakrani, P. S. Chong, A. Chvirova, P. Collard, M. Danilov, C. Davis

Faculty Publications

Inter-channel mis-synchronisation can be a limiting factor to the time resolution of high performance timing detectors with multiple readout channels and independent electronics units. In these systems, time calibration methods employed must be able to efficiently correct for minimal mis-synchronisation between channels and achieve the best detector performance. We present an iterative time calibration method based on Markov Chains, suitable for detector systems with multiple readout channels. Starting from correlated hit pairs alone, and without requiring an external reference time measurement, the method solves for fixed per-channel offsets, with precision limited only by the intrinsic single-channel resolution. A mathematical proof …

Real-Time Electron Spectrometer Utilizing A Permanent Magnet And Diode Detector Array, Mason W. Heath, Kenneth L. Matthews, Garrett M. Pitcher, Kenneth R. Hogstrom

Faculty Publications

Background: Magnetic spectrometers have been previously described for measuring energy spectra of therapeutic electron beams. However, challenges for clinical utilization have been their size, weight, and limited real-time capabilities. Development of a compact, lightweight, and inexpensive device with real-time readout will make an electron spectrometer a practical clinical tool. Purpose: This work integrates a commercial diode detector array with a permanent dipole magnet to create a practical real-time energy spectrometer for therapeutic electron beams. Methods: A 4 kg, 0.55 T permanent dipole magnet was coupled to two PC boards of a Sun Nuclear SRS MapCHECK device, which provided two interlaced …

The Sensitivity Of Future Hydroclimate Projections To Topography And Large-Scale Dust Forcing In The Luquillo Mountains Of Eastern Puerto Rico, J. Preece, C. Johnson, T. Mote, P. Miller, M. Williams

Faculty Publications

Precipitation over Puerto Rico is expected to decline in coming decades, threatening an important source of surface water supply. However, earth system models neither resolve fine-scale orographic impacts nor the radiative effects of Saharan dust aerosols on precipitation over the island's mountains. Here, we use the Weather Research and Forecasting model coupled with chemistry (WRF-Chem) to downscale global climate model projections to a convection-resolving 4-km resolution for both dust and no-dust scenarios. We compare the regional hydroclimate during three periods: historical (2014–2018), mid- (2045–2049) and end-21st century (2085–2089), using output from an RCP8.5 simulation of the Community Earth System Model, …

The Expanded Regulatory Significance Of Saharan Dust Plumes In The United States, Paul Miller, Kimberly Hamilton-Wims, Ken Holmes, Doug Melancon, Jason Meyers, Tegan Treadaway

Faculty Publications

Given the recent reduction in the U.S. National Ambient Air Quality Standard (NAAQS) for annual PM2.5from 12 to 9 μg m^–3, the contribution of exceptional, though natural, particulate transport events has assumed greater regulatory relevance. This study examines the evolution of a June 2022 trans-Atlantic Saharan dust outbreak and contextualizes its impact on the 2023 PM2.5design values (DVs) for continental U.S. air quality monitors. The results demonstrate that the intrusion of Saharan dust yielded mean 24 h PM2.5values > 35 μg m^–3for multiple days across the Central U.S. and single-handedly elevated the 2022 mean annual PM2.5by > 0.5 …

Time Series Changes Of Surficial Sediments On Eastern Ship Shoal, Louisiana Shelf, Adam Gartelman, Kehui Xu, Brian J. Roberts, David Samuel Johnson, Madison Liotta

Faculty Publications

Ship Shoal, a large transgressive sand body on the Louisiana continental shelf, is a critical sediment source for coastal restoration. This study evaluates spatial and temporal variability in sediment grain size, percents organic matter (%OM), and carbonate (%CO3) across the shoal crest (REF), Caminada Dredge Pit (CAM), and Terrebonne Dredge Pit (TER). Sediment samples were collected between 2020 and 2022 using box cores and analyzed for grain size, %OM, and %CO3, with temporal and spatial patterns assessed through statistical comparisons, correlation analyses, and random forest regression models. Results show that dredged areas act as sinks for fine-grained, organic-rich sediments, with …

A Comparison Of Characteristics Of Infilling Sediments In Three Mud-Capped Dredge Pits On The Louisiana Continental Shelf, Wenqiang Zhang, Kehui Xu, Chaochen Jia, Adam Gartelman, Omar Alawneh, Navid Jafari, Colin Herke, Madison Liotta, Samuel J. Bentley

Faculty Publications

Due to high sedimentation rate up to ~1 m/year, mud-capped dredge pits (MCDP) are often considered natural laboratories for studying sedimentary processes, slope stability and the impacts of dredging activities on marine environments. Although many studies have been performed on the Louisiana shelf, there is a lack of high spatial resolution research covering the eastern, central and western Louisiana shelf to comprehensively investigate sediment infilling. Eighteen vibracores were collected from the Peveto Channel dredge pit (PC), Raccoon Island dredge pit (RI) and Sandy Point dredge pit (SP), and more than 1300 samples were analyzed to study the spatial variation in …

A Test Of The Abundant-Center Hypothesis For Stream Fishes, Matthew L.W. Zink, Brandon K. Peoples, Julian D. Olden, Lily M. Thompson, William K. Annis, Stephen R. Midway

Faculty Publications

The abundant-center hypothesis (ACH) provides a conceptual model for predicting range-wide distributions of species abundance, suggesting that abundance peaks in the center of the geographic range and declines towards range edges. Empirical studies testing the ACH and its subsequent derivations predominantly occurred in terrestrial systems and reported mixed support. Moreover, none of these models consider the possibility of multiple geographic areas of elevated abundance (which we refer to as ‘abundant cores'). Naturally dispersal limited species may exhibit multiple abundant cores, requiring refinement of the ACH. We used fish species abundances from 29 206 community monitoring surveys and weighted geospatial kernel …

Recovery Of The X-Ray Polarisation Of Swift J1727.8-1613 After The Soft-To-Hard Spectral Transition (Corrigendum) (Astronomy And Astrophysics (2024) 686 (L12) Doi: 10.1051/0004-6361/202450566), J. Podgorný, J. Svoboda, M. Dovčiak, A. Veledina, J. Poutanen, P. Kaaret, S. Bianchi, A. Ingram, F. Capitanio, S. R. Datta, E. Egron, H. Krawczynski, G. Matt, F. Muleri, P. O. Petrucci, T. D. Russell, J. F. Steiner, N. Bollemeijer, M. Brigitte, N. Castro Segura, R. Emami, J. A. García, K. Hu, M. N. Iacolina, V. Kravtsov, L. Marra, G. Mastroserio, T. Muñoz-Darias, E. Nathan, M. Negro, A. Ratheesh, N. Rodriguez Cavero, R. Taverna

Faculty Publications

(Figure presented) In Fig. 4, the X-ray hardness value for observation 8 was plotted using a count-based ratio instead of the energy-flux-based ratio used for other points in the figure. The correction of the position of this point in Fig. 4 does not affect any other figures, results, or conclusions in the paper.

Sub-Gev Dark Matter And Mev Gamma-Ray Detection With Cosi, Yu Watanabe, Shigeki Matsumoto, Christopher M. Karwin, Tom Melia, Michela Negro, Thomas Siegert, Yuki Watanabe, Hiroki Yoneda, Tadayuki Takahashi

Faculty Publications

Sub-GeV dark matter (DM) has been attracting more attention due to the negative results searching for traditional weakly interacting massive particles (WIMPs). Such particles are expected to produce gamma rays from annihilation in the MeV energy region. Advancements in technology have opened up possibilities to precisely detect MeV gamma rays, leading to the upcoming space-based mission of the Compton Spectrometer and Imager (COSI). We comprehensively and quantitatively study the phenomenology of sub-GeV DM to determine if the COSI observations will probe their viable model parameter regions. We first construct models to describe sub-GeV DM based on the minimality and renormalizability …

Phase-Amplitude Separation Of Wave Function As Local Gauge Transformation, A. R.P. Rau

Faculty Publications

A quantum-mechanical wave function is complex, but all observations are real, expressible through expectation values and transition matrix elements that involve the wave functions. It can be useful to separate at the outset the amplitude and phase as real quantities that together carry the same information that is contained in the complex wave function. Two main avenues for doing so go way back in the history of the subject and have been used both for scattering and bound states. A connection is made here to gauge transformations of electrodynamics where the advent of quantum mechanics and later quantum field theory …

How The Inter-Nucleon Force Shapes Emergent Collectivity And Imparts Uncertainties In Ab Initio Nuclear Observables, Kevin Becker

LSU Doctoral Dissertations

The importance of collective motion in atomic nuclei has been well-established for many decades. Even before the advent of the nuclear shell model and its much-needed answers to surprising empirical phenomena, collectivity and surface deformation have played a vital role in broadening our knowledge. Reconciling the collective and single-particle camps into a unified description required tremendous strides in the application of group theory and advances in high-performance supercomputing, and thanks to these efforts the symmetry-adapted no-core shell model, or SA-NCSM, has developed into a reliable model for the study of deformed light and medium-mass nuclei. State-of-the-art calculations reveal remarkably simple …

Compound-Specific Isotope Records Of Dust Provenance And Hydroclimate In The North Pacific And Marginal Seas Of East Asia: Integrating N-Alkane Δ13c And Δd With Standardized Analytical Frameworks, Julian W. Traphagan

LSU Doctoral Dissertations

This dissertation presents advancements in compound-specific isotope analysis (CSIA) through methodological innovation and paleoclimate reconstruction in Central and East Asia. Utilizing plant wax n-alkanes from International Ocean Discovery Program (IODP) and Ocean Drilling Program (ODP) sediment cores, this research reconstructs atmospheric circulation shifts responding to tectonic evolution and climate transitions since the Late Miocene.

Chapter 1 investigates hydrogen isotope compositions (δD_wax) from IODP U1430 (Sea of Japan), ODP 886, and ODP 1208 (North Pacific) to trace dust provenance and hydroclimate changes since ~13 Ma. Results reveal persistently segmented source-to-sink systems: the Sea of Japan dominated by westerly …

Effects Of Cryoprotective And Mitochondrial Stabilizing Agents On Vitrified Bovine Oocytes, Allison Hoang

LSU Master's Theses

Oocyte vitrification success is highly dependent on cryoprotectant agent (CPA) choice as well as possible additives that could help preserve mitochondrial membrane potential (mMP), reactive oxygen species (ROS) production, and calcium homeostasis within the cell. It is a delicate balance between levels needed for proper oocyte function and activation and levels needed to induce apoptotic pathways. The results of oocyte cryopreservation determine the eventual oocyte viability and subsequent fertilization and embryo development.

In this study potential permeating cryoprotectant combinations were explored such as ethylene glycol (EG) and propylene glycol (PG) or EG in combination with dimethyl sulfoxide (DMSO). Also, the …

Investigation Of Co-Current And Counter-Current Multiphase Flow In Upstream Drilling And Production Applications, Hazem Fleifel

LSU Doctoral Dissertations

In the domain of upstream Petroleum Engineering, the dynamics of co-current and counter-current multiphase flows present huge challenges, significantly impacting the efficiency of associated processes. This study investigates two specific applications concerning these flow behaviors, involving both laboratory experiments and transient computer simulations. This work investigates two distinct well control and production enhancement processes, involving multiphase flow dynamics: the bullheading kill procedure and liquid-assisted gas lift (LAGL).

The first topic (Topic 1) explores the bullheading process, a type of well control methods, by challenging the traditional understanding that gas removal efficiency increases monotonically with injection pump flow rate. Through 1D …

Designing A Data Collection And Visualization Toolkit For Scalable Tensor Algebra In Quantum Chemistry Applications, Epiya J. Ebiapia

LSU Master's Theses

Large-scale quantum chemistry computations, such as those executed with the Tensor Algebra for Many-body Methods (TAMM) framework, require careful configuration of runtime parameters to achieve high performance and cost efficiency in high-performance computing (HPC) and cloud environments. Without effective performance analysis tools, researchers risk inefficient use of computational resources, leading to longer runtimes and higher costs.

To address this challenge, this thesis presents the design and implementation of a performance profiling and visualization toolkit for TAMM, developed as part of the DOE TEC4 project in collaboration with Pacific Northwest National Laboratory, Microsoft, and Louisiana State University. The toolkit collects detailed …

Examining Multi-Level Support-Related Factors Influencing School-Based Mental Health Services Across Various Types Of U.S. Public High Schools, Wendy L. Wilson

LSU Doctoral Dissertations

Youth mental health is a global and national public health issue, with notable disparities in access to school-based mental health services (SBMHS; Kieling et al., 2024). This highlights the urgent need to identify supportive factors that can enhance service availability within educational settings. This cross-sectional, exploratory-descriptive study aimed to identify multi-level support-related factors (SRFs) at the student, school, and community levels that best predict SBMHS availability across different types of U.S. public high schools. The researcher conducted a secondary data analysis of a sample of 855 respondents who completed the 2017-18 School Survey on Crime and Safety. Various univariate, bivariate, …

Exploring Longitudinal Stability Of Spatiotemporal Sequential Patterns By Means Of Autoencoder Schemes For Eeg Based Personal Identification, Muhammed E. Oztemel

LSU Doctoral Dissertations

Robust personal identification remains a critical and challenging task in the digital era. Electroencephalography (EEG) offers a unique biometric modality that captures individual brain dynamics through complex neural signals. This dissertation proposes autoencoder (AE) based feature extraction and subject identification through these features. EEG recordings are first transformed into topographic maps to represent spatial brain activity. Consecutive topomaps are then concatenated to capture temporal transitions across frames. Convolutional autoencoders (CAEs) are used to learn spatial and temporal patterns, while domain-adaptive AEs are designed to model evoked potential based responses. Additionally, self-attention mechanism is incorporated to enhance feature representation. To analyze …

Pinch: Pipeline-Informed Noise Characterization In Ligo’S Third Observing Run, Zach Yarbrough, Andre Guimaraes, Prathamesh Joshi, Gabriela González, Andrew Valentini

Faculty Publications

We present a method to identify and categorize gravitational wave candidate triggers identified by matched filtering gravitational wave searches (pipelines) caused by transient noise (glitches) in gravitational wave detectors using support vector machine (SVM) classifiers. Our approach involves training SVM models on pipeline triggers which occur outside periods of excess noise to distinguish between triggers caused by random noise and those induced by glitches. This method is applied independently to the triggers produced by the GstLAL search pipeline on data from the laser interferometer gravitational-wave observatory Hanford and Livingston observatories during the second half of the O3 observing run. The …

The Characteristic Function Of The Cube Of A Gaussian Random Variable, Andreas Boukas

Journal of Stochastic Analysis

Using the spectral resolution of the multiplication operator on the Schwartz class of L2(R,C), we compute the characteristic function of the cube of a Gaussian random variable.

Subtropical Marine Cloud Brightening Suppresses The El Niño–Southern Oscillation, C. Xing, S. Stevenson, J. Fasullo, C. Harrison, C. Chen, J. Wan, J. Coupe, C. Pfleger

Faculty Publications

Stratospheric aerosol injection (SAI) and marine cloud brightening (MCB) are two proposed methods of compensating for greenhouse gas-induced warming by reflecting incoming solar radiation. However, their effects on the El Niño–Southern Oscillation (ENSO), a critical mode of climate variability, are poorly understood. Here we use ensembles of climate model simulations to show that deploying MCB in the subtropical eastern Pacific dramatically reduces ENSO amplitude by approximately 61%, while SAI has a negligible impact. MCB increases cloud albedo, which cools the subtropical eastern Pacific and triggers a loss of moist static energy. This cooling promotes atmospheric subsidence, dries the tropical Pacific, …