Digital Commons Network^™

Modeling Crowd Feedback In The Mobile App Market, Grant S. Williams

LSU Doctoral Dissertations

Mobile application (app) stores, such as Google Play and the Apple App Store, have recently emerged as a new model of online distribution platform. These stores have expanded in size in the past five years to host millions of apps, offering end-users of mobile software virtually unlimited options to choose from. In such a competitive market, no app is too big to fail. In fact, recent evidence has shown that most apps lose their users within the first 90 days after initial release. Therefore, app developers have to remain up-to-date with their end-users’ needs in order to survive. Staying close …

Developing The 21st Century Musician: A Case Study Of Applied Tuba And Euphonium Studio Models At American Universities, Chasse Benjamin Duplantis

LSU Doctoral Dissertations

Musicians navigate an ever-changing career landscape that requires a strong set of ancillary skills in addition to their assumed musical mastery. A successful 21^stcentury career, musical or beyond, demands versatility and command of skills that may include communication, innovation, adaptability, and higher order thinking skills. This document explores the applied professor’s role in introducing the aforementioned elements as well as musical versatility, critical thinking, and skills in collaboration, pedagogy, research, entrepreneurship, and business. Finally, it will examine how or even if the combination of these skills affects student success. The reader will find interviews with successful tuba and …

Aerodynamic Flutter And Buffeting Of Long-Span Bridges Under Wind Load, Shuqian Liu

LSU Doctoral Dissertations

With the continuous increase of span lengths, the aerodynamic characteristics of long-span bridges under external wind excitation have become much more complex and wind-induced vibration has always been a problem of great concern. The present research targets on the aerodynamic performance of long-span bridges under wind load with an emphasis on bridge flutter and buffeting.

For the aerodynamic flutter analysis of long-span bridges, the present research investigated the effects of the wind turbulence on flutter stability. The characterizations of the self-excited forces are presented in both the frequency-domain and in the time-domain, and the flutter analysis is conducted under both …

Insights Into The Collaborative Process Between Electronic Music Composers And Commissioning Saxophonists, Taylor Barbay Assad

LSU Doctoral Dissertations

This monograph gives information about the collaborative process that takes place between commissioning saxophonists and composers of electronic music. It focuses specifically on music for solo performers and works for electronics, either with prerecorded tape or live electronics. The core of this paper centers on interviews conducted with composers of works for saxophone and electronics and professional saxophonists about the nature of their collaborations on new music for solo saxophone and electronics. The composers and performers selected had previously worked together on preparing and premiering a piece. Questions were developed for interviews of the composers and performers. The questions were …

Precision Of Parameter Estimation In Quantum Metrology, Chenglong You

LSU Doctoral Dissertations

The fundamental precision limit of an interferometer is crucial since it bounds the best possible sensitivity one could achieve using such a device. This thesis will focus on several different interferometers and try to give the ultimate precision bounds by carefully counting all the resources used in the interferometers.

The thesis begins with the basics of the quantum state of light. The fundamentals of quantum metrology are also reviewed and discussed. More specifically, the terminology of classical and quantum Cram\'er-Rao bound and classical and quantum Fisher information are introduced.

Chapter 3 discusses the conclusive precision bounds in two-mode interferometer such …

Fate Of Selected Pollutants Of Concern On Particulate Matter (Pm) Surface, Ajit Ghimire

LSU Doctoral Dissertations

This research focuses on the environmental fate of particle associated pollutants such as Polybrominated Diphenyl Ethers (PBDEs), Polyaromatic Hydrocarbons (PAHs), and Environmentally Persistent Free Radicals (EPFRs) with a special emphasis on their transformation due to interaction with a matrix or co-pollutants. It encompasses two approaches to the stated problems: analysis of samples collected in the environment and laboratory simulation of the molecular transformations.

The PBDE studies relied on the ambient air Particulate Matter (PM) samples collected from Bangkok, Thailand. Results showed the presence of various PBDE homologs from tri- to hepta-PBDEs on both PM_2.5and Total Suspended Particle (TSP) …

Foucauldian Dynamics In The Formation Of A Fifth Grade Writing Culture, Ashley Renee Watson

LSU Doctoral Dissertations

This study looks at a student writing culture in a fifth grade English language arts classroom through the lens of Foucauldian power dynamics to examine the power relationships in the classroom and curriculum. The research questions were: 1) What is the nature of a writing culture in a fifth-grade writing classroom? 2) What are students’ perceptions of writing in a fifth grade ELA classroom? The methodology for the study was case study research.

The research took place during the 2017-2018 school year at Southeast Elementary School in Lancaster County in the southeastern part of the United States. Data was collected …

Quantitative Evaluation Of A Lightweight Sediment For A Physical Model Of The Lower Mississippi River, Mauricio Hooper

LSU Doctoral Dissertations

The Lower Mississippi River Physical Model (LMRPM), housed at the LSU Center for River Studies on the Baton Rouge, LA Water Campus, is a distorted, movable bed model comprising the lower 195 miles of the Mississippi River from Donaldsonville through the Head of Passes into the Gulf of Mexico. Since the LMRPM was designed to replicate the hydraulics (i.e., flow and river stages) and bulk non-cohesive sediment transport, the model lightweight sediment must replicate both the incipient motion and two-dimensional dune characteristics (height and length). In addition, the model scale and distortion require that the sediment time scale be determined …

Infrared Laser Ablation For Biomolecule Sampling, Kelin Wang

LSU Doctoral Dissertations

In this research, an infrared laser at a wavelength of 3 µm was used to ablate material from tissue sections for biomolecule analysis. Pulsed infrared (IR) irradiation of tissue with a focused laser beam efficiently removed biomolecules, such as proteins, enzymes, DNA, and RNA from tissue sections for further analysis. In a proteomics project, matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) was used to determine regions of interest (ROI) for laser ablation. The matrix was then washed off. By overlaying the MSI generated heat-map, the section was sampled using IR laser ablation and custom stage-control software. Two ROI were selected …

The Modern Mississippi: Provenance Indicators And Human Impact, Brittney Anne Gregory

LSU Doctoral Dissertations

Given the significant degree to which the modern Mississippi River and its tributaries have been altered through dams, levees, and diversions, it is important to understand how sediment is transported from source to sink. The objective of this dissertation is to explore how the modern Mississippi River transports sediment from its tributaries to its delta using three independent proxies. Provenance indicators have traditionally been an effective way with which to characterize sediment transport in large river systems. First, detrital U-Pb zircon dating is used to investigate modern flux and possible anthropogenic influences on coarse-grained sediment within the modern Mississippi River. …

Cationic Cobalt (Ii) Hydroformylation, Drew Michael Hood

LSU Doctoral Dissertations

While investigating a bimetallic cobalt hydroformylation catalyst a new class of monometallic cationic cobalt (II) hydroformylation catalyst were discovered. These newly discovered catalyst proved to be very unique with high hydroformylation activity under mild conditions. The pre-catalyst were characterized using various methods including NMR, EPR, MS, and X-ray crystallography. Similarly the active catalyst was also investigated using NMR, EPR, FTIR, and X-ray crystallography. Various catalyst modifications were investigated for their effects on hydroformylation activity. Likewise various reaction parameters were probed to determine their effect on hydroformylation activity. Finally the best cationic cobalt (II) catalyst were directly compared to industry standards …

Improving Coupled Enzyme Assays With Capillary Electrophoresis, Thu Hoai Nguyen

LSU Doctoral Dissertations

The goal of this project is to address limitations of coupled enzyme assays using capillary electrophoresis (CE). In some enzyme assays, it is ineffective to directly detect products and substrates spectroscopically (absorption or fluorescence). Coupling the enzyme-catalyzed reaction of interest with another enzyme-catalyzed reaction allows for indirect detection of product formation or substrate depletion for the target enzyme. While conventional coupled enzyme assays are facile for kinetic measurements, they can be problematic for inhibition screening due to spectral and inhibitor interferences. To address these limitations of coupled assays, CE has been used to develop enzyme assays for acetyl-coenzyme A carboxylase …

Effective Geometric Modeling For Scientific Computing And Forensic Reconstruction, Celong Liu

LSU Doctoral Dissertations

Geometric modeling is a fundamental and critical problem for many computer graphic and computer vision problems. We usually want to build a parameterization which establishes a low-distortion one-to-one map between geometric data and canonical parametric domain, and it is a fundamental tool to support many visual data processing tasks such as mesh generation, finite element simulations, visual analytics, geometric reconstruction, etc. In this dissertation, I studied two problems. The first is to construct low- distortion canonical (polycube) parameterization of large-scale geometric regions, with which high-quality semi-structured quad meshes can be generated and used to facilitate more efficient scientific computing. The …

Essays On The Role Of Systematic And Idiosyncratic Volatility In Pricing Individual Equity Options, Mobina Shafaati

LSU Doctoral Dissertations

It is widely accepted that the value of an option is an increasing function of the underlying volatility. The positive relation between volatility and option price is intuitive only if we keep all other determinants of the option value constant, including the stock price. The notion that an asset price is completely unaffected by the volatility of the asset is virtually unacceptable in asset pricing theory and holds only in a stylized one-factor world in which the volatility change is completely diversifiable. In Chapter 1, I examine the role of the non-zero correlation of the underlying asset return and its …

Optimization Of Quantum Optical Metrology Systems, Nicholas Michael Studer

LSU Doctoral Dissertations

It can be said that all of humanity's efforts can be understood as a problem of optimization. We each have a natural sense of what is ``good'' or ``bad'' and thus our actions tend towards maximizing -- or optimizing -- some notion of good and minimizing those things we perceive as bad or undesirable.

Within the sciences, the greatest form of good is knowledge. It is this pursuit of knowledge that leads to not only life-saving innovations and technology, but also to furthering our understanding of our natural world and driving our philosophical pursuits.

The principle method of obtaining knowledge …

Vulnerability Of Industrial Facilities In The Lower Mississippi River Industrial Corridor To Relative Sea Level Rise And Tropical Cyclone Storm Surge, Joseph Blake Harris

LSU Doctoral Dissertations

Relative sea level rise (RSLR) and tropical cyclone-induced storm surge are major threats to the Lower Mississippi River Industrial Corridor (LMRIC) which has approximately 120 industrial complexes located within the corridor. Spatial interpolation methods were applied to the 2004 National Oceanic and Atmospheric published Technical Report #50 subsidence dataset and cross-validation techniques were used to determine the accuracy of each method. Digital elevation models (DEMs) were created for the years 2025, 2050, and 2075, based on these predictive surface of subsidence rates. Future DEMs were utilized to model RSLR and determine the extent of storm surge on the LMRIC by …

A Comprehensive Techno-Economic Framework For Shale Gas Exploitation And Distribution In The United States, Jorge Asis Charbel Chebeir

LSU Doctoral Dissertations

Over the past years, shale gas has turned into one of the most significant sources of energy in the United States. Technological advancements have provided the energy industry with the necessary tools to allow the economic exploitation of an enormous volume of natural gas trapped in shale formations. This has boosted the domestic gas production and generated a boom in other sectors of the economy in the country. However, major challenges are involved in the development of shale gas resources. A drastic decline of wells’ productivity, the costs involved in the gas production and distribution facets, and the volatile behavior …

Deltaic Wetland Dynamics From Seasonal To Centennial Scales, Giancarlo A. Restreppo

LSU Doctoral Dissertations

The lower plain of the Mississippi River Delta contains approximately five coastal sedimentary basins that are topographically defined, and one shelf-crossing depocenter (the Birds Foot Delta). These depositional systems receive varying quantities of sediment from fluvial and marine sources and have rates of coastal land loss that are roughly inversely proportional to fluvial sediment supply. To combat land loss along these regions, Louisiana has launched a historic campaign to sustain and regrow coastal lands using, in part, river sediment diversions. Fine sediments constitute the majority of sediment load in the Mississippi River, but are under-studied with respect to dispersal processes, …

From Rationality To Relationality: Teacher-Student Relationship As Unknowing, Shaofei Han

LSU Doctoral Dissertations

This dissertation reimagines the teacher-student relationship through a philosophical approach that draws on Laozi, Karen Barad, Deleuze & Guattari, and Emmanuel Levinas. The teacher-student relationship is normally considered a relationship of the knower (teacher) and the unknower (student) based on the modern western tradition of episteme. This dissertation interrogates the modern binary of the teacher/student, subject/object relationship by bringing ontology and ethics into educational discourse. The problematic practices of modern schooling include the reduction of teaching to knowledge transmission, and the rigid dichotomy of a subject/object relation between teacher and student. Following a Taoist Way of philosophical thinking, this work …

Can Assisted Reproductive Technologies Help Conserve 300 Million Years Of Evolution? A First Attempt At Developing These Technologies For Male Reptiles, Sean M. Perry

LSU Doctoral Dissertations

Biodiversity loss is the most critical environmental problem threatening ecosystem, animal, and human health today. Increases in extinction rates have been observed over the past 50 years, with reptile losses occurring twelve times faster than traditional extinction rates. This demonstrated biodiversity loss is secondary to climate change, habitat destruction, infectious disease, invasive species, poaching, and unsustainable trade. Approximately 20% of all reptiles are threatened with extinction and population declines are approaching rates similar to the current amphibian extinction crisis. Preventing the extinction of reptiles will require humans to acknowledge these losses and develop plans to preserve these evolutionary sentinel species. …

Investigating Cationic Metal Centers For Hydroformylation, Ryan Alexander Johnson

LSU Doctoral Dissertations

Bimetallic cooperativity can potentially increase activity of reactions. This concept is another way to increase reactivity besides simply focusing on the steric and electronic effects of a ligand. A binucleating tetrasphosphine ligand has been developed to showcase bimetallic cooperativity between two rhodium metal centers. Hydroformylation is a widely used industrial process to produce aldehydes from alkenes, H₂, and CO. The dirhodium catalyst, [Rh₂(μ-CO)(CO)₃(rac-et,ph-P4-Ph)](BF₄)₂,is highly active leading to favorable results when using a DMF/water solvent system, 1-hexene, 90 psi 1:1 H₂/CO, and 90° C: initial turnover frequency …

Iron Mediated Organic Preservation In A River Influenced Continental Margin, Neha Ajit Ghaisas

LSU Doctoral Dissertations

Continental margins such as the Mississippi river influenced Louisiana shelf (MIS), are important land-ocean interfaces where excessive water column productivity and rapid burial results in large amounts of organic carbon (OC) being sequestered in the sediments. The preservation of OC in sediments is controlled by a number of processes among which mineral-OC interactions are considered to be more important. Specifically, the interactions between sediment iron (Fe) species and OC have been shown to promote carbon preservation. However, the exact nature of preservation mechanism is not well understood and is based on limited global data, which specifically lacks estimates from large …

Evaluating Seasonal Nutrient Fluxes In Emerging And Eroding Wetlands Of The Louisiana Delta Plain, Kiran Upreti

LSU Doctoral Dissertations

Deltaic wetlands can ameliorate high NO₃^- loads via denitrification, a dominant NO₃^- reduction pathway in inland and coastal habitats. Dissimilatory Nitrate Reduction to Ammonia (DNRA), in contrast to denitrification, conserves N within the system and has been found to be favored over denitrification with increase in salinity and temperature. There are no studies in the Louisiana Deltaic plain with simultaneous estimation of denitrification and DNRA. Increased P availability has been shown to increase denitrification so it is essential to understand P biogeochemistry when studying N cycle. Here, we evaluated net denitrification using N₂:Ar and …

Phase Estimation In Linear And Nonlinear Interferometers, Sushovit Adhikari

LSU Doctoral Dissertations

Phase estimation has a wide range of applications. Over the years, several strategies have been studied to improve precision in phase estimation. These strategies include using exotic quantum states to quantum detection schemes. This dissertation summarizes my effort in improving the precision of phase estimation with a linear and nonlinear interferometer.

Chapter 1 introduces quantum optics and quantum metrology. I introduce all relevant quantum states of light used. We also look into tools and terminologies of quantum metrology such as Fisher information, shot-noise limit, Heisenberg limit, etc., along with examples of phase estimation with a Mach-Zehnder interferometer.

In Chapter 2, …

Evaluation Of Naturally Occurring Radioactive Material In Seafood From The Gulf Of Mexico, Charles Algeo Wilson Iv

LSU Doctoral Dissertations

Radioactive disintegration of naturally occurring radioactive material was modeled with high precision and no assumptions to better understand serial decay in high order disequibrlia. This model helped develop a new method of quick analysis of NORM, where radioactivity can be measured with reasonable certainty before secular equilibrium is established. This approach was a significant improvement on previous similar approaches, halving time required for the same results and reduced wait time compared to classical approaches by 92%. Consequentially, NORM was measured in selected seafood samples from three areas in the Gulf of Mexico. Red Snapper, Red Drum, Northern Whiting, Spotted Trout …

Monitoring Sediment Dynamics And Vegetation Competition Based On Micro-Topography And Terrestrial Lidar For Wetland Restoration, Xukai Zhang

LSU Doctoral Dissertations

With the ability to attenuate wave and limit erosion, coastal wetlands are important to protect shoreline for coastal communities. Micro-topography in coastal wetlands has a significant influence on hydrology, habitat variability and ecosystem functions. However, when mapping micro-topography by terrestrial LiDAR in coastal environments, the coverage of dense vegetation leads to a relatively low chance of laser penetration through the canopy to the ground. This dissertation proposes a rapid and flexible terrain mapping solution for the densely vegetated coastal environment by integrating crown structure from terrestrial LiDAR with terrain samples from GPS. The validated results in the study site demonstrate …

An Airlifted Tidal Mesocosm For Oil Degradation Studies, Daniel Christopher Alt

LSU Doctoral Dissertations

Mesocosms were constructed to allow scientists to isolate variables in a microtidal marsh environment, mimicking the natural conditions found in Terrebonne Bay. The control offered by these mesocosms is given by a process control system that takes user inputs and automates water movement. Twelve mesocosms were constructed, each holding 4.02 m³ (142 ft³) of marsh soil and 3.88 m³ (137 ft³) of water to give 3 experimental levels and a control, all in triplicate.

Each mesocosms that was constructed contained marsh plants in soil plugs 9 feet in diameter and 3 feet deep. These …

Ignition And Extinction Behavior Of Fuels In A Microcombustor, Pawan Sharma

LSU Doctoral Dissertations

Conventional fuel testing device-CFR engine requires large quantities of fuels, which makes it unsuitable for research of small samples of fuels. This current study seeks to address this limitation by using an externally heated microcombustor as an alternative fuel testing device. Mainly three combustion behaviors have been observed inside a microcombustor: strong flames at higher flow rates, Flames with Repetitive Extinction and Ignition (FREI) at intermediate flow rates, and weak flames at marginal flow rates. In previous studies, weak combustion behavior has been proven suitable to study fuel properties from small samples of fuels. Microcombustor experiments typically rely on flame …

A Multi-Proxy Approach To Refining Paleotempestology Records On The Northern Gulf Of Mexico Coast, Marianne Elizabeth Dietz

LSU Doctoral Dissertations

Reconstructing pre-historic hurricane activity is typically accomplished through the analysis of sandy overwash deposits identified in coastal lake settings. This method has been used successfully in many parts of the world and can extend the hurricane record thousands of years into the past. However, this approach also has its limitations. This dissertation addresses some of the limitations associated with geologic proxies used to reconstruct hurricane landfalls in the absence of historic data and tests new proxies for the identification of hurricane-derived overwash deposits. Modern storm deposits from two sites on the northern Gulf of Mexico coast are analyzed in detail …

Atomic Force Microscopy Tip-Enhanced Laser Ablation, Fan Cao

LSU Doctoral Dissertations

In the present work, an apertureless atomic force microscope (AFM) tip-enhanced laser ablation (TELA) system was developed and investigated. An AFM was coupled to an optical parametric oscillator (OPO) wavelength tunable laser for sample ablation with a submicron sampling size. The AFM was used to image the surface and hold the AFM tip 10 nm above the sample surface. The AFM tip is coated with a layer of gold with a thickness of 35 nm. The incident laser wavelength was tuned in the visible and near-infrared (IR) region and focused on the AFM tip. With the tip-enhancement effect, ablation craters …