Digital Commons Network^™

Bioremediation Of Petroleum-Based Contaminants By Alkane-Degrading Bacterium Alcanivorax Borkumensis, Amber Julaine Pete

LSU Doctoral Dissertations

The world’s dependence on petroleum hydrocarbons has led to significant environmental implications. For example, oil spills cause lasting environmental damage, and the increase of plastics in the marine environment has been growing, specifically, microplastics that can be difficult to detect due to their small size. Petroleum hydrocarbons occur naturally in nearly all marine environments, which has allowed hundreds of microorganisms to evolve to utilize these hydrocarbons as their primary energy source. These microbes are classified as hydrocarbonoclastic and are utilized to remove spilled oil biodegradation. Over the last ten years, progress has been made in the biodegradation of oil spills …

Experimental Investigation Of The Physical Properties Of Irmsnn (M = 1, 3 And N = 2, 4, 7), Smita Speer

LSU Doctoral Dissertations

Exploration of transition metal stannides, formed from a combination of transition metals (T) and Sn, has resulted in the discovery a variety of materials with interesting physical properties, which is in part due to the complexity of interactions that can occur between the T-d orbitals and Sn-p orbitals. There have been observations of (extremely) large magnetoresistance [1-4], topological flat and nearly flat bands [5-7], superconducting behavior in 2D and 3D systems [5, 8-11], ultrahigh carrier mobility [12-13], and more attributed to d-p orbital mixing in such systems. This dissertation will address the effects of T-Sn interactions …

Control And Planning For Mobile Manipulators Used In Large Scale Manufacturing Processes, Joshua T. Nguyen

LSU Master's Theses

Sanding operations in industry is one of the few manufacturing tasks that has yet to achieve automation. Sanding tasks require skilled operators that have developed a sense of when a work piece is sufficiently sanded. In order to achieve automation in sanding with robotic systems, this developed sense, or intelligence, that human operators have needs to be understood and implemented in order to achieve, at the minimum, the same quality of work. The system will also need to have the equivalent reach of a human operator and not be constrained to a single, small workspace. This thesis developed solutions for …

Predictive Thermal Modeling And Characterization Of Ultrasonic Consolidation Process For Thermoplastic Composites, Madeline Kirby

LSU Master's Theses

Ultrasonic consolidation (USC) of thermoplastic composites (TPCs) is a highly attractive and promising method to manufacture high-performance composites. This work focuses on USC of dry carbon fiber (CF) fabrics with high-temperature polyphenylene sulfide (PPS) films. Experimental trials to assess feasibility of the process are time-consuming. Consequently, a predictive thermal model would facilitate process parameters selection to reduce expensive trial-and-error approaches. This paper presents a 2D finite element model of samples under consolidation, incorporating equations for viscoelastic heating, matrix phase change, and material properties. Theoretical temperature profiles for nodes of interest were compared to the corresponding experimental temperature curves for various …

Local And State Climate Initiatives In Louisiana Since 2005: Content And Thematic Analyses, Jessie F. Parrott

LSU Master's Theses

Louisiana is uniquely exposed to severe weather because of its geography and climate. Louisiana’s extreme weather is exacerbated by anthropogenic climate change, which will worsen in the future. The risks its population and environment are exposed to has generated several policies and planning documents, nine of which are analyzed in this thesis. Three plans are from the state level, three are from the parish level, and three are from the urban (New Orleans) level. These planning documents pose various adaptation and mitigation actions to ameliorate and address multiple climate issues. These actions utilize specific mitigation strategies. The content and thematic …

Numerical Modeling Of Pile Responses Under Lateral Loading Considering The Scour Effects, Jungmin Lee

LSU Master's Theses

This thesis focuses on the 3D numerical analysis of the laterally loaded pile. For numerical modeling/analysis, ABAQUS, a widely used commercial software, is used. Non-scour and scour conditions are considered for this thesis. Two elastoplastic constitutive models, Mohr-Coulomb model and Cam Clay model, are applied. Unknown material and interface properties are calibrated based on two references which explained the numerical analysis of the laterally loaded pile under the non-scour condition. Different cases of scour depth, S_d, scour width, S_w, and scour slope angle, a, are applied for the laterally loaded pile analysis under the scour …

Understanding Children's Museums' Approaches To Diversity: A Critical And Socio-Cultural Investigation, Amber Nicole Smith

LSU Doctoral Dissertations

Children begin to develop self-awareness and awareness of others at an early age (Marion, 2011). Before they reach kindergarten, children begin to make distinctions about race by noticing similarities and differences between themselves and others (Winkler, 2009). Exposing young children to diversity can help each child embrace their identity, accept and celebrate differences, and be accepting of themselves and others (Cole & Verwayne, 2018).

The purpose of this study is to explore how children’s museums support diversity through their programs and planning. The research of this study focuses on four children’s museums located in the United States. There are many …

Electro-Mechanical Response Of Ultrasonically Welded Thermoplastic Composite Interfaces Under Static And Cyclic Flexural Loads Using Nanocomposites, Wencai Li, Genevieve Palardy

Faculty Publications

In this work, glass fiber/polypropylene adherends were ultrasonically welded with multifunctional nanocomposite polymer films containing multi-walled carbon nanotubes (MWCNTs), embedded at the interface. Their potential for strain and damage monitoring under flexural loading for two different joint configurations was assessed via electrical resistance changes. Cyclic bending tests at various interval durations were first performed on welded single-lap joints to analyze the stability of different MWCNT weight contents (5 wt % to 20 wt %). Subsequently, 3-point bending joints (3PBJs) were welded with single- and double-film configurations and then subjected to static and cyclic loading to assess the monitoring capability through …

Neural Networks For Interference Mitigation In Satellite Communication Systems, Martha E. Cash

LSU Master's Theses

The objective of this thesis is to utilize the power of machine learning to develop a neural network-aided receiver in a DVBS-2X satellite communication system to improve the downlink transmission quality in the presence of interference. An emphasis is placed on mitigating the effects caused by non-linear distortions, carrier frequency offset, and additive white Gaussian noise. This thesis proposes a feed-forward neural network with two hidden layers to compensate for the distortions in the received signal. The proposed system model uses 16-APSK modulation scheme. The neural network is tested under varying degrees of non-linear distortion, frequency offsets, and varying levels …

Navier-Stokes Equations In One And Two Dimensions, Jon Nerdal

LSU Master's Theses

The Navier-Stokes equations are an important tool in understanding and describing fluid flow. We investigate different formulations of the incompressible Navier-Stokes equations in the one-dimensional case along an axis and in the two-dimensional case in a circular pipe without swirl. For the one-dimensional case we show that the velocity approximations are remarkably accurate and we suggest that understanding this simple axial behaviour is an important starting point for further exploration in higher dimensions. The complexity of the boundary is then increased with the two-dimensional case of fluid flow through the cross section of a circular pipe, where we investigate two …

Characterization Of Electrophoretic Deposited Zinc Oxide Nanopartices For The Fabrication Of Next-Generation Nanoscale Electronic Applications, Fawwaz Abduh A. Hazzazi

LSU Doctoral Dissertations

Several reports state that it is crucial to analyze nanoscale semiconductor materials and devices with potential benefits to meet the need for next-generation nanoelectronics, bio, and nanosensors. The progress in the electronics field is as significant now, with modern technology constantly evolving and a greater focus on more efficient robust optoelectronic applications. This dissertation focuses on the study and examination of the practicality of Electrophoretic Deposition (EPD) of zinc oxide (ZnO) nanoparticles (NPs) for use in semiconductor applications.

The feasibility of several synthesized electrolytes, with and without surfactants and APTES surface functionalization, is discussed. The primary objective of this study …

Scale Up Of A Novel Method To Maximize Malonyl-Coa In Escherichia Coli, Clifford Harris Leblanc Iv

LSU Master's Theses

The instability of oil’s price along with its limited availability and impact on the environment motivate the search for an alternative feedstock that can sustain the profitability of chemical companies. Industrial biotechnology can promote renewable sources of energy and products by using microorganisms to produce a wide range of chemical compounds. The three-carbon metabolite, malonyl-CoA, can serve as a precursor to a variety of industrial chemicals. The major hurdle with using malonyl-CoA in industry is that its intracellular concentration in Escherichia Coli is very low. Previous attempts to increase the intracellular level of malonyl-CoA have ranged from genetic engineering of …

Tunable Passive Shock And Vibration Isolators For Rotational Isolation, Chase B. Lemaire

LSU Master's Theses

Shock and vibration isolation are a critical need in helmets, which are widely used to protect athletes, workers, soldiers, and astronauts. Passive vibration isolation systems are a good option when mass and volume should be minimized and when the experienced loadings can be predicted. However, it is frequently challenging to find materials and structures which exhibit the optimal vibration and impact isolation properties for an application. As a case study illustrating a novel design paradigm for rotational shock absorption, a family of optimal solutions for the physical properties of American football helmets is presented. Lumped parameter Simulink models simulate a …

Micro Heat Exchanger To Cool Cerebrospinal Fluid For Brain Injury Treatment, Sachin Dahiya

LSU Master's Theses

Hypothermia is accepted as a method to preserve cells and tissue. Clinical evidence shows that administration of hypothermia could lead to neuroprotection after cardiac arrest. Non-invasive methods such as surface cooling devices, drugs and cold liquid ventilation are available to induce hypothermia. These approaches for achieving hypothermia have not been optimized yet. The surface cooling methods are generally slow and may lead to additional thermal shock to the body. Here, we propose a rapid, selective cooling method for the brain using a micro heat exchanger to cool the cerebrospinal fluids (CSF). We designed and 3D printed a U-type heat exchanger …

Acidic Catalyst, James J. Spivey, Kunlun Ding, Swarom Kanitkar

College of Engineering Patents

Methods of preparing an acidic catalyst are disclosed that include heating a metal halide to produce a vapor phase metal halide, contacting an initial support material with the vapor phase metal halide in a reaction vessel causing a first chemical reaction and producing an intermediate acidic catalyst, contacting the intermediate acidic catalyst with HBr causing a second chemical reaction and producing an acidic catalyst product which is both more acidic than the intermediate acidic catalyst and more acidic than the initial support material.

Capturing Wheat Phenotypes At The Genome Level, Babar Hussain, Bala A. Akpınar, Michael Alaux, Ahmed M. Algharib, Deepmala Sehgal, Zulfiqar Ali, Gudbjorg I. Aradottir, Jacqueline Batley, Arnaud Bellec, Alison R. Bentley, Halise B. Cagirici, Luigi Cattivelli, Fred Choulet, James Cockram, Francesca Desiderio, Pierre Devaux, Munevver Dogramaci, Gabriel Dorado, Susanne Dreisigacker, David Edwards, Khaoula El-Hassouni, Kellye Eversole, Tzion Fahima, Melania Figueroa, Sergio Gálvez, Kulvinder S. Gill, Liubov Govta, Alvina Gul, Goetz Hensel, Pilar Hernandez, Leonardo Abdiel Crespo-Herrera, Amir Ibrahim, Benjamin Kilian

Faculty Publications

Recent technological advances in next-generation sequencing (NGS) technologies have dramatically reduced the cost of DNA sequencing, allowing species with large and complex genomes to be sequenced. Although bread wheat (Triticum aestivum L.) is one of the world’s most important food crops, efficient exploitation of molecular marker-assisted breeding approaches has lagged behind that achieved in other crop species, due to its large polyploid genome. However, an international public–private effort spanning 9 years reported over 65% draft genome of bread wheat in 2014, and finally, after more than a decade culminated in the release of a gold-standard, fully annotated reference wheat-genome assembly …

A Wet/Dry Point Treatment Method Of Fvcom, Part Ii: Application To The Okatee/Colleton River In South Carolina, Changsheng Chen, Haosheng Huang, Huichan Lin, Jack Blanton, Chunyan Li, Francisco Andrade

Faculty Publications

The wet/dry point treatment method of FVCOM was applied to simulate the tide-induced flooding/drying process in the estuarine–tidal-creek–saltmarsh complex of the Okatee/Colleton River Estuary, South Carolina. The simulation results were compared with observed currents at three mooring sites and flooded areas observed from remote-sensing hypsometric measurements, demonstrating that FVCOM can robustly reproduce tidal and residual currents in the river and the flooding process onto the intertidal saltmarsh. The simulated flow field reveals that the Okatee/Colleton River Estuary is characterized by multiple residual eddies. Driven by the periodic tidal forcing, this estuarine system features a chaotic water transport process. Numerous residual …

A Roadmap For Quality Control Of Hardening And Hardened Printed Concrete, Viktor Mechtcherine, Kim Van Tittelboom, Ali Kazemian, Eric Kreiger, Behzad Nematollahi, Venkatesh Naidu Nerella, Manu Santhanam, Geert De Schutter, Gideon Van Zijl, Dirk Lowke, Egor Ivaniuk, Markus Taubert, Freek Bos

Faculty Publications

This article focuses on the specifics in characterizing the properties of additively manufactured, cement-based materials in their hardening and hardened states. Such characterization is required for the material development, structural design, and quality control of both printable material and 3D-printed elements. The related challenges are associated with the printed material's layered structure, which results in higher degrees of anisotropy and inhomogeneity in comparison to conventionally cast concrete. Thus, in the production of test specimens, the particularities of the real-scale 3D-printing process must be considered. Here a distinction is made between the production of samples for material testing prior to or …

Louisiana Agriculture Summer, 2022

Louisiana Agriculture

LSU AgCenter researchers constantly search for ways to improve Louisiana agriculture by increasing yields and profitability. They also seek to understand new and less popular crops that could thrive in our region. Professor Yan Chen is helping develop the tea industry along the Gulf Coast, working closely with producers to understand how to grow tea (Camellia sinensis) in the region, and her work is featured in the latest issue of Louisiana Agriculture magazine. The magazine also includes a look into Grow Louisiana and Growing Farmers, two programs designed to help beginning farmers learn the business. Researchers from the …

Event Based Approach For Modeling Indoor Airflow Patterns, Ehsan Mousavi, Arup Bhattacharya

Faculty Publications

People spend a significant proportion of their time indoors, where the quality of indoor air affects the productivity, efficiency, and well-being of occupants. One of the oldest challenges in building construction is designing a ventilation system that ensures optimum indoor air quality. Acceptable indoor air should provide thermal comfort and minimize human exposure to contamination. Characterizing these two elements requires information on both heat/mass transfer in the microenvironment and the time-specific activity of individuals who move among these microenvironments. While researchers have utilized simulation tools to investigate this complex human-environment interaction, current numerical techniques severely limit the simulations to overly …

From Soils To Streams: Connecting Terrestrial Carbon Transformation, Chemical Weathering, And Solute Export Across Hydrological Regimes, Hang Wen, Pamela L. Sullivan, Sharon A. Billings, Hoori Ajami, Alejandro Cueva, Alejandro Flores, Daniel R. Hirmas, Aaron N. Koop, Katie Murenbeeld, Xi Zhang, Li Li

Faculty Publications

Soil biota generates carbon that exports vertically to the atmosphere (CO2) and transports laterally to streams and rivers (dissolved organic and inorganic carbon, DOC and DIC). These processes, together with chemical weathering, vary with flow paths across hydrological regimes; yet an integrated understanding of these interactive processes is still lacking. Here we ask: How and to what extent do subsurface carbon transformation, chemical weathering, and solute export differ across hydrological and subsurface structure regimes? We address this question using a hillslope reactive transport model calibrated using soil CO2 and water chemistry data from Fitch, a temperate forest at the ecotone …

Charging Of Radioactive And Environmental Airborne Particles, Gyoung G. Jang, Alexander I. Wiechert, Yong Ha Kim, Austin P. Ladshaw, Tyler Spano, Joanna Mcfarlane, Kristian Myhre, Joon Jin Song, Sotira Yiacoumi, Costas Tsouris

Faculty Publications

The charging of various airborne particles was investigated using single-particle levitation and charge-balance equations. Though radioactive decay and triboelectrification can induce charging, it is typically assumed that the aerosols in a radioactive plume will not carry significant charge at steady state since atmospheric particles can have their charge neutralized through the capture of adjacent counter-ions (i.e., diffusion charging). To assess this assumption, we directly measured the surface charge and charge density of various triboelectrically charged aerosols including radioactive uranium oxide (< 1 μm), urban dust, Arizona desert dust, hydrophilic and hydrophobic silica nanoparticles, and graphene oxide powders using an electric field-assisted particle levitator in air. Of these particles, uranium oxide aerosols exhibited the highest surface charge density. Charge balance equations were employed to predict the average charge gained from radioactive decay as a function of time and to evaluate the effects of diffusion charging on triboelectrically charged radioactive and non-radioactive particles in the atmosphere. Simulation results show that particles, initially charged through triboelectrification, can be quickly discharged by diffusion charging in the absence of radioactive decay. Nevertheless, simulation results also indicate that particles can be strongly charged when they carry radionuclides. These experimental and simulation results suggest that radioactive decay can induce strong particle charging that may potentially affect atmospheric transport of airborne radionuclides.

Conditional Quantum Plasmonic Sensing, Fatemeh Mostafavi, Zeinab Jafari, Michelle L.J. Lollie, Chenglong You, Israel De Leon, Omar S. Magaña-Loaiza

Faculty Publications

The possibility of using weak optical signals to perform sensing of delicate samples constitutes one of the main goals of quantum photonic sensing. Furthermore, the nanoscale confinement of electromagnetic near fields in photonic platforms through surface plasmon polaritons has motivated the development of highly sensitive quantum plasmonic sensors. Despite the enormous potential of plasmonic platforms for sensing, this class of sensors is ultimately limited by the quantum statistical fluctuations of surface plasmons. Indeed, the fluctuations of the electromagnetic field severely limit the performance of quantum plasmonic sensing platforms in which delicate samples are characterized using weak near-field signals. Furthermore, the …

Better Colloidal Lithography: Tilt-Rotate Evaporation Overcomes The Limits Of Plasma Etching, Macayla J. Caso, Michael G. Benton, Kevin M. Mcpeak

Faculty Publications

Colloidal lithography (CL) is a promising method for large-area fabrication of nanohole and nanodot arrays with applications in optical biosensing, separations, and magnetic data storage. However, reducing the diameter of the polystyrene sphere mask by plasma etching unavoidably increases their coefficient of variation (CV) and deforms their shape, thereby limiting the pitch-to-hole-diameter ratio of the resulting nanohole array to less than 3:1 and the minimum hole size to 200 nm with a 10% or better CV. We show that tilt-rotate evaporation colloidal lithography (TRE-CL) breaks the trade-off between hole diameter and polydispersity by leveraging glancing angle evaporation, not plasma etching, …

Droplet Behavior In Overexpanded Supersonic Two-Phase Jets, Shyam Menon, Mohana Gurunadhan

Faculty Publications

The interaction of liquid droplets generated by spray atomization with high-speed co-flowing gas is of interest in various applications including fuel injection, spray cooling, and surface coating. The underlying processes involve interactions between the droplets themselves, and with the carrier gas. Additionally, they are influenced by shock and expansion waves present in high-speed flows, accompanied by resulting velocity and pressure fluctuations. Non-intrusive diagnostics including Shadowgraphy and Phase Doppler Particle Anemometry, along with flow simulations, are used to study droplet behavior, characterized by size and velocity changes, as a finely atomized spray is propelled by a carrier gas through a supersonic, …

Predicting Elastic Constants Of Refractory Complex Concentrated Alloys Using Machine Learning Approach, Uttam Bhandari, Hamed Ghadimi, Congyan Zhang, Shizhong Yang, Shengmin Guo

Faculty Publications

Refractory complex concentrated alloys (RCCAs) have drawn increasing attention recently owing to their balanced mechanical properties, including excellent creep resistance, ductility, and oxidation resistance. The mechanical and thermal properties of RCCAs are directly linked with the elastic constants. However, it is time consuming and expensive to obtain the elastic constants of RCCAs with conventional trial-and-error experiments. The elastic constants of RCCAs are predicted using a combination of density functional theory simulation data and machine learning (ML) algorithms in this study. The elastic constants of several RCCAs are predicted using the random forest regressor, gradient boosting regressor (GBR), and XGBoost regression …

Towards A Fully Autonomous Robotic System For Detection And Removal Of Surface Defects In Fiber Glass Panels, James Oubre, William Ard, Joshua Nguyen, Corina Barbalata

Faculty Publications

Wind blades for turbines are commonly manufactured from fiber glass. A last step in the manufacturing process of such blades is sanding of the surface to remove defects that occur during the process. This paper presents an autonomous robotic system performing sanding operations for surface defect removal in fiber glass panels. The proposed approach uses a collaborative robotic system equipped with a vision system. Surface defects are detected using traditional computer vision algorithms and a path planning strategy is designed that solves multi-goal and coverage path planning problems. The robotic system equipped with a specialized end-effector will autonomously perform sanding …

Southwest Pacific Tropical Cyclone Development Classification Utilizing Machine Learning And Synoptic Composites, Rupsa Bhowmick, Jill C. Trepanier, Alex M. Haberlie

Faculty Publications

This study evaluates the ability of machine learning algorithms to classify tropical depressions (TDs) and tropical storms (TSs) in the western region of the southwest Pacific Ocean (SWPO). Decision rules are generated to predict the environment required for a depression to fully develop into a mature storm, and the most influential predictors in the classification decision are ranked. TD and TS are discriminated based on a maximum sustained wind speed threshold (≥17 ms−1). Various aerosol, thermodynamic, and dynamic parameters are extracted closest to the initiation point of each non-developing and developing sample. The covariates associated with each labelled sample are …

Validation Of The Guess-18 For The Usability Of A Virtual Reality Racing Game, William A. Carman

LSU Master's Theses

Virtual reality (VR) technology has been in development for many decades, with recent strides in the consumer market. Head-mounted displays (HMDs) provide an immersive VR experience by inserting users into an artificially constructed digital world. However, there is currently no standardized tool for measuring the usability of a VR system or environment. The GUESS-18 is a validated usability questionnaire designed for measuring the usability of video games with 9 factors present in video games. The objective of this study was to validate the GUESS-18 for measuring the usability of VR in a gaming environment.

Participants played Assetto Corsa, a racing …

Exploring Toluene Biosynthesis In Microbial Consortia Derived From Sediments And Superfund Site Groundwater, Raymond J. Poche

LSU Master's Theses

While the aromatic hydrocarbon toluene is widely regarded as a contaminant associated with discharges of crude oil and refined petroleum products (e.g., gasoline), the enzyme phenylacetate decarboxylase catalyzes the decarboxylation of phenylacetate to yield toluene. Research described in this thesis further investigated toluene biosynthesis by a microbial consortium originating from chlorinated solvent-contaminated groundwater near Baton Rouge, Louisiana. In anoxic growth media supplemented with phenylacetate as a precursor, toluene accumulation was found to be maximal at near-neutral to slightly acidic pHs (toluene accumulation greater than 1 mg/L at pH in the range of 5.6 to 7.6, but was not observed for …