Digital Commons Network^™

Lifecycle Reactive Transport Modeling For Assessing Integrity In Offshore Energy Systems, Temitope Ayokunle Ajayi

LSU Doctoral Dissertations

Subsurface leaks and spills are a matter of significant concern to the oil and gas industry because of their impact on health, safety and environment. It is thus important to study and assess the integrity of our energy systems and the physico-chemical processes that affect them.

To avoid leakage of fluids from wellbores, barrier materials are used for sealing formation fluids and creating a single flow path through the well. These barrier materials are constantly subjected to subsurface fluid fluxes and temperature, pressure and chemical conditions over the extended periods the wells remain underground. This makes it imperative to assess …

A New Insight Into Fungal Cell Wall Architecture By Functional Genomics And Solid-State Nmr Along With Recent Advancements In Dynamic Nuclear Polarization For Analyzing Biomolecules, Arnab Chakraborty

LSU Master's Theses

This dissertation summarizes the findings related to the way by which supramolecular architecture of fungal cell wall changes with genetic mutation, dispensing genes responsible for biosynthesis of cell wall polysaccharides. This is necessary because without perfect picture of how supramolecular assembly changes with genetic mutation it is hard to assess new anti-fungal targets. Alongside this we have highlighted how recent advancement into Dynamic Nuclear Polarization (DNP) methods improved characterization of biomolecules both in case of labeled and unlabeled samples.

First study utilized Solid-state NMR (SSNMR) which is a non-destructive technique hence enabled us for the first time to deduce how …

Evaluating And Incorporating Site Variability In Different Geotechnical Engineering Applications, Md Habibur Rahman

LSU Doctoral Dissertations

Site investigation and characterization of subsurface soil conditions are crucial for geotechnical engineering design and analysis. Geotechnical properties vary inherently from one point to another within the same site. This study focused on evaluating the site variability from cone penetration tests (CPT) and soil boring data, and its implementation into the Load and Resistance Factor Design (LRFD) formulation. The total Coefficient of Variation (COV_R,total) for each site was estimated from COV_R,spatial (Spatial Coefficient of Variation) and COV_R,method (Method Coefficient of Variation) which were then used to calibrate the resistance factors (ϕ_spatial, ϕ_total) …

The Impact Of Second-Year Membership Experiences On Retention Among Panhellenic Sororities, Elizabeth Richardson Newell

LSU Doctoral Dissertations

ABSTRACT

Sorority membership retention is a newly emerging research topic with little to no existing information on what motivates members to remain. There are countless studies concerning college student retention in general, but there have yet to be studies that focus specifically on sorority women and their membership experiences. One major research question drove this study: What factors and/or experiences influence a second year National Panhellenic Conference (NPC) sorority member’s decision to actively participate in their sorority?

Using a theoretical framework developed from the social integration retention model proposed by Braxton, Hirschy, and McClendon in 2011, this study explored what …

In-Phantom Film Measurements Of Two Treatment Planning Systems For Single-Fraction Spine Sbrt, Michael J. Taylor

LSU Master's Theses

Purpose: Treatment planning accuracy for spine stereotactic body radiation therapy (SBRT) varies depending on the dose calculation algorithm utilized in the treatment planning system (TPS). This project compared the end-to-end accuracy between spine SBRT plans calculated in a convolution-superposition based TPS (TPS_CS) and Monte Carlo based TPS (TPS_MC) with radiochromic film measurements. The hypothesis was that TPS_MC would calculate the dose gradient in the critical region between the vertebral body and the spinal cord more accurately than TPS_CS.

Methods: Single-fraction spine SBRT treatments following RTOG 0631 and local institutional guidelines were planned in …

A Relational Study Of Self-Taught And Formally Trained Musicians: Trends Within Memory And Socioeconomic Factors, Matthew N. Jimenez, Emily M. Elliott

LSU Master's Theses

It has been well documented that musicians perform better in memory tasks than non-musicians. The current study utilized self-taught musicians, formally trained musicians, and non-musicians, and focused on short-term memory (STM), musicianship, and SES factors to explore this finding. Do the memory benefits of musical training extend to self-taught musicians? First, we addressed musicianship amongst all groups using the Goldsmith’s Musical Sophistication Index (GMSI), which contained subjective and objective measures. The subjective measure was a survey regarding the role of music in daily life. In the objective measures, participants completed tests of beat and melody perception. To measure STM, participants …

Changes In Heat Metrics Following A Major Hurricane And Implications On Heat Stress, Cade Reesman

LSU Master's Theses

Tropical cyclones modify surface-atmosphere interactions in several ways, including the destruction of patches of tree canopy, increasing the direct and diffuse (shortwave) radiation reaching the surface. This addition of radiation at the surface impacts the sensible, latent, and substrate heat (energy) fluxes, generating heat anomalies along the hurricane’s track, which, among other effects, contributes to the higher post-hurricane surface air temperatures. This study consists of a case study on Hurricane Laura (2020) to examine hurricane defoliation impacts on heat stress metrics. Normalized difference vegetation index (NDVI) data from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) identified the spatial extent of defoliation …

Neural Stimulator, Jose A. Parodi Amaya, Edward F. Austin, Jin-Woo Choi

Pennington Biomedical Research Center Patents

Methods and apparatus are disclosed relating to the stimulating of tissue including nerve tissue based on combinations of capacitors and resistors. Application and removal of voltage to an electrical circuit is taught as part of a method of creating voltage waveforms for nerve and other tissue with such waveforms creating neural signals. The electrical apparatus taught may, include a first electrical node grounded through a first resistor; a second electrical node grounded through a second resistor; a first capacitor connected to both the first electrical node and the second electrical node; a second capacitor separating the second electrical node from …

Sodium Mediates Developmentally Plastic Responses In Plants And Herbivores, Luis Santiago-Rosario

LSU Doctoral Dissertations

Sodium plays a crucial role in organismal performance, trophic-level interactions, and eco-evolutionary dynamics. For plants, sodium impacts osmoregulation, growth, and water uptake. For animals, sodium is essential influencing osmoregulatory processes, muscle and neural development, and blood regulation. My dissertation aims to disentangle why sodium mismatch affects resource-consumer interactions and its influence on morphological and behavioral plasticity. First, I identified how sodium impacts plant performance and sodium accumulation strategies. I initially focused my research on understanding how increasing substrate sodium affects plant growth and tissue sodium accumulation strategies in controlled settings using a systematic review approach. I found that saltier plants …

Temperature Across Vegetation Canopy-Water-Soil Interfaces Is Modulated By Hydroperiod And Extreme Weather In Coastal Wetlands, Xiaochen Zhao, Victor H. Rivera-Monroy, Chunyan Li, Ivan A. Vargas-Lopez, Robert V. Rohli, Z. George Xue, Edward Castañeda-Moya, Carlos Coronado-Molina

Faculty Publications

Environmental temperature is a widely used variable to describe weather and climate conditions. The use of temperature anomalies to identify variations in climate and weather systems makes temperature a key variable to evaluate not only climate variability but also shifts in ecosystem structural and functional properties. In contrast to terrestrial ecosystems, the assessment of regional temperature anomalies in coastal wetlands is more complex since the local temperature is modulated by hydrology and weather. Thus, it is unknown how the regional free-air temperature (TFree) is coupled to local temperature anomalies, which can vary across interfaces among vegetation canopy, water, and soil …

Ligers Interferometric Survey Of M Dwarf Diameters, Tyler Gregory Ellis

LSU Doctoral Dissertations

In this dissertation, I present the largest single collection of M dwarf stellar radii in over a decade and contextualize these measurements with the systematic model discrepancies. The measurements of stellar angular diameters are also important in the quantification of the properties of exoplanets. In order to estimate the property of the exoplanet, it is first necessary to quantify the properties of the planet's host star. Using the survey results complemented with previous direct observations of the angular diameters of low mass stars, I develop updated updated surface brightness relationships. These relationships allow predictions of angular diameters using easy to …

Improved Method For Testing Integrity Loss Of Wells With Sustained Casing Pressure, Mohammad Kazemi, Andrew K. Wojtanowicz

Faculty Publications

The pressure bleed-down/build-up (B/B) testing is enforced by the Bureau of Safty and Environmental Enforcement (BSEE) regulations in the US for gas-leaking wells with recurrent casing head annular pressure dubbed “Sustained Casing Pressure” (SCP). The bleed down test involves bleeding the pressure with a needle valve. Once the pressure reached to zero or stabilized, the valve is closedand a 24-h pressure monitoring starts. Analysis of the tests mandated by regulations involves merely a qualitative assessment of the low or high level of environmental risk measured by leak size. A quantitative analysis—based on mathematical models—has been already proposed and used for …

The Energy Balance Model Of Obesity: Beyond Calories In, Calories Out, Kevin D. Hall, I. Sadaf Farooqi, Jeffery M. Friedman, Samuel Klein, Ruth J.F. Loos, David J. Mangelsdorf, Stephen O'Rahilly, Eric Ravussin, Leanne M. Redman, Donna H. Ryan, John R. Speakman, Deirdre K. Tobias

Clinical Research Faculty Publications

A recent Perspective article described the "carbohydrate-insulin model (CIM)"of obesity, asserting that it "better reflects knowledge on the biology of weight control"as compared with what was described as the "dominant energy balance model (EBM),"which fails to consider "biological mechanisms that promote weight gain."Unfortunately, the Perspective conflated and confused the principle of energy balance, a law of physics that is agnostic as to obesity mechanisms, with the EBM as a theoretical model of obesity that is firmly based on biology. In doing so, the authors presented a false choice between the CIM and a caricature of the EBM that does not …

On Uniqueness And Stability For The Boltzmann-Enskog Equation, Martin Friesen, Barbara Ruediger, Padmanabhan Subdar

Faculty Publications

The time-evolution of a moderately dense gas in a vacuum is described in classical mechanics by a particle density function obtained from the Boltzmann-Enskog equation. Based on a McKean-Vlasov equation with jumps, the associated stochastic process was recently constructed by modified Picard iterations with the mean-field interactions, and more generally, by a system of interacting particles. By the introduction of a shifted distance that exactly compensates for the free transport term that accrues in the spatially inhomogeneous setting, we prove in this work an inequality on the Wasserstein distance for any two measure-valued solutions to the Boltzmann-Enskog equation. As a …

Reinforcement Learning In A Quantum Network, Roy Pace

Honors Capstones

No abstract provided.

Regional Variation In Growth Status. The Peruvian Health And Optimist Growth Study, Alcibíades Bustamante, Carla Santos, Sara Pereira, Duarte Freitas, Peter T. Katzmarzyk, José Maia

Population and Public Health Science Faculty Publications

Objective: This study aims to (1) investigate differences in weight, body mass index (BMI), and waist circumference (WC) among Peruvian children and adolescents living in three areas located at different altitudes; (2) compare age- and sex-specific height, weight, and BMI within each site with US reference data. Methods: We sampled 8753 subjects (4130 boys), aged 4 to 17 years from sea level, rainforest, and high-altitude. Height, weight, and WC were measured and BMI was calculated. Analysis of variance was used to compare variables across geographic regions, and the Hoff and Blackburn procedure was used to compare the Peruvian results with …

On The Spherical Slice Transform, Boris Rubin

Faculty Publications

We study the spherical slice transform which assigns to a function f on the unit sphere Sn in n+1 the integrals of f over cross-sections of Sn by k-dimensional affine planes passing through the north pole (0,..., 0, 1). These transforms are known when k = n. We consider all 2 ≤ k ≤ n and obtain an explicit formula connecting with the classical (k - 1)-plane Radon-John transform Rk-1 on n. Using this connection, known facts for Rk-1, like inversion formulas, support theorems, representation on zonal functions, and some others, are reformulated for .

Value-Added Utilization Of Wheat Straw: From Cellulose And Cellulose Nanofiber To All-Cellulose Nanocomposite Film, Hongxia Bian, Yanyan Yang, Peng Tu, Jonathan Y. Chen

Faculty Publications

To accelerate the high value-added usage of agricultural residue, cellulose and cellulose nanofibers (CNFs) were extracted from wheat straw and then formed into all-cellulose nanocomposite films. The acid–alkali method (AM) and the extraction method (EM) were respectively adopted to prepare wheat straw cellulose (WSC), and the TEMPO oxidation method was used to extract CNFs. The nanocomposite films were fabricated by dissolving WSC and adding different CNF contents of 0.0, 0.5, 1.5, and 3.0%. There was a better miscibility for the all-cellulose nanocomposite film prepared by EM (Composite-E) compared to that for the all-cellulose nanocomposite film prepared by AM (Composite-A). Composite-E …

Delineation Of Cancer Service Areas Anchored By Major Cancer Centers In The United States, Changzhen Wang, Fahui Wang, Tracy Onega

Faculty Publications

Defining a reliable geographic unit pertaining to cancer care is essential in its assessment, planning, and management. This study aims to delineate and characterize the cancer service areas (CSA) accounting for the presence of major cancer centers in the United States. We used the Medicare enrollment and claims from January 1, 2014 to September 30, 2015 to build a spatial network from patients with cancer to cancer care facilities that provided inpatient and outpatient care of cancer-directed surgery, chemotherapy, and radiation. After excluding those without clinical care or outside of the United States, we identified 94 NCI-designated and other academic …

An Optimal Ordering Policy For A Visitor-Based Purchasing System With Stochastic Delivery Time And Partial Prepayment For Profit Maximization, Ata Allah Taleizadeh, Hamidreza Zarei, Bhaba R. Sarker

Faculty Publications

The classical inventory control policies assume that orders are paid for at the time of their receipts, but in practice, suppliers may require retailers to pay a fraction of the purchasing cost in advance, and sometimes allow them to pay this cost in several prepayments during a predetermined period. Planning inventory replenishments and prepayments become challenging when decisions must be made under uncertainty, especially when delivery time is stochastic, and shortages may occur. This paper develops an inventory control model in a purchasing system in which a visitor sells the product of a manufacturer, and a buyer receives call from …

The Effect Of Pesticides And Ultraviolet Radiation On Coastal Invertebrates And The Need For More Research On Multiple Stressors And Predator-Prey Interactions, Chase Robinson

Honors Capstones

No abstract provided.

An Integrated Network Representation Of Multiple Cancer-Specific Data For Graph-Based Machine Learning, L M. Pu, M Singha, H C. Wu, C Busch, L M. Pu, M Brylinski

Faculty Publications

Genomic profiles of cancer cells provide valuable information on genetic alterations in cancer. Several recent studies employed these data to predict the response of cancer cell lines to drug treatment. Nonetheless, due to the multifactorial phenotypes and intricate mechanisms of cancer, the accurate prediction of the effect of pharmacotherapy on a specific cell line based on the genetic information alone is problematic. Emphasizing on the system-level complexity of cancer, we devised a procedure to integrate multiple heterogeneous data, including biological networks, genomics, inhibitor profiling, and gene-disease associations, into a unified graph structure. In order to construct compact, yet information-rich cancer-specific …

Improving Kernel Artifact Extraction In Linux Memory Samples Using The Slub Allocator, Daniel A. Donze

LSU Master's Theses

Memory forensics allows an investigator to analyze the volatile memory (RAM) of a computer, providing a view into the system state of the machine as it was running. Examples of items found in memory samples that are of interest to investigators are kernel data structures which can represent processes, files, and sockets. The SLUB allocator is the default small-request memory allocator for modern Linux systems. SLUB allocates “slabs”, which are contiguous sections of pre-allocated memory that are used to efficiently service allocation requests. The predecessor to SLUB, the SLAB allocator, tracked every slab it allocated, allowing extraction of allocated slabs …

Quantitative Analysis Of The Maximum Rate And Minimum Duration For A 200 Km Stepwise Retreat Of The Bindschadler Ice Stream At ~11.5 Cal Kyr Bp, Matthew E Kratochvil

LSU Master's Theses

Small-scale morainal ridges on the middle continental shelf of the Whales Deep Basin partly record the rapid opening of a 200-km grounding line embayment slightly after ~11.5 cal kyr BP. The overlapping pattern of backstepped moraines indicates that the grounding line oscillated back and forth during the retreat. Published sediment fluxes were combined with new sediment volume mapping of the moraines to infer the rates at which the grounding line retreated. The analyses indicate that the rates of grounding line retreat on the eastern flank of the embayment ranged from ~490 m a^-1 to 1,300 m a^-1. …

Sedimentation Processes In A Dredge Pit And Surrounding Environment In Northern Gulf Of Mexico, Adam M. Gartelman

LSU Master's Theses

Louisiana’s Coastal Protection and Restoration Authority has been using dredged sand from onshore and offshore sites for barrier island restoration and beach nourishment projects. Caminada dredge pit (CDP) located on eastern Ship Shoal in inner Louisiana shelf underwent two increments in 2014 and 2016, with material used to restore Caminada Headland and nearby areas. Multiple pits in East Terrebonne borrow areas (ET) right next to CDP were then used for East Timbalier Island and other barrier islands near Terrebonne Bay. ET1, north of CDP, was dredged in 2020, and ET2, west of CDP, was dredged in 2020 and 2021 used …

Malware And Memory Forensics On M1 Macs, Charles E. Glass

LSU Master's Theses

As malware continues to evolve, infection mechanisms that can only be seen in memory are increasingly commonplace. These techniques evade traditional forensic analysis, requiring the use of memory forensics. Memory forensics allows for the recovery of historical data created by running malware, including information that it tries to hide. Memory analysis capabilities have lagged behind on Apple's new M1 architecture while the number of malicious programs only grows. To make matters worse, Apple has developed Rosetta 2, the translation layer for running x86_64 binaries on an M1 Mac. As a result, all malware compiled for Intel Macs is theoretically functional …

New Chemoselective Dehydration And Cyclization Strategies Enabled By Triphosgene, Moshood Oreofeoluwa Ganiu

LSU Doctoral Dissertations

Since Friedrich Wöhler’s synthesis of urea in 1828, the techniques of organic synthesis have developed and advanced greatly. This advancement has facilitated the discovery of new organic synthetic methods, and enabled access to a more expansive chemical space. The purpose of this dissertation is to present the development of new organic synthetic reactions that were uncovered through previous discoveries. Additionally, the main theme of this work relies on exploiting the versatility of triphosgene in organic synthesis. To this end, the developed chemistries rely on the ability of triphosgene to serve as an activating agent, and a chloride source.

Chapter 1 …

Data Mining And Knowledge Discovery In Chemical Processes: Effect Of Alternative Processing Techniques, Luis A. Briceno-Mena, Miriam Nnadili, Michael G. Benton, Jose A. Romagnoli

Faculty Publications

Data mining and knowledge discovery (DMKD) focuses on extracting useful information from data. In the chemical process industry, tasks such as process monitoring, fault detection, process control, optimization, etc., can be achieved using DMKD. However, the selection of the appropriate method for each step in the DMKD process, namely data cleaning, sampling, scaling, dimensionality reduction (DR), clustering, clustering analysis and data visualization to obtain meaningful insights is far from trivial. In this contribution, a computational environment (FastMan) is introduced and used to illustrate how method selection affects DMKD in chemical process data. Two case studies, using data from a simulated …

Connections Between Interglacial Variation And Lithological Variability Within Midland Basin Permian Shale Rocks In Martin County, Texas, Helen Rice Hammon

LSU Master's Theses

The Upper Pennsylvanian (323.2–289.9 Ma) and Lower Permian (289.9-251 Ma), (Wolfcamp and Spraberry formations) interval of the Midland Basin, West Texas, contains a mixed succession of shale, carbonate, and siltstone/sandstone lithofacies that accumulated in a deep-water marine environment under variable hydrographic restrictions. The heterogenous stratigraphy found in the Wolfcamp and Spraberry formation was formed in response to variations in sea level and a transition from a glacial to an interglacial climate during the Early Permian. These fluctuations left behind alternating beds of mudstone and carbonate, interwoven with thin sandstone beds. Because the Wolfcamp and Spraberry formations are highly heterolithic, it …

Efficient Low Dimensional Representation Of Vector Gaussian Distributions, Md Mahmudul Hasan

LSU Doctoral Dissertations

This dissertation seeks to find optimal graphical tree model for low dimensional representation of vector Gaussian distributions. For a special case we assumed that the population co-variance matrix $\Sigma_x$ has an additional latent graphical constraint, namely, a latent star topology. We have found the Constrained Minimum Determinant Factor Analysis (CMDFA) and Constrained Minimum Trace Factor Analysis (CMTFA) decompositions of this special $\Sigma_x$ in connection with the operational meanings of the respective solutions. Characterizing the CMDFA solution of special $\Sigma_x$, according to the second interpretation of Wyner's common information, is equivalent to solving the source coding problem of finding the minimum …