Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 477

Full-Text Articles in Entire DC Network

Droplet-Based Fuel Property Measurements, Wanjun Dang Dec 2021

Droplet-Based Fuel Property Measurements, Wanjun Dang

LSU Doctoral Dissertations

Ongoing work to find renewable biofuels to function as drop-in replacements or blending components with gasoline has identified a large number of fuel candidates. Given the vast number of potential biomass-derived fuel molecules and limited sample sizes, screening tools are required to down-select candidate fuels having desired physical properties to ensure good engine performance. This work investigates approaches for rapid screening of candidate fuels using micro-liter sample sizes targeting four properties -- surface tension, viscosity, heat of vaporization (HOV), and vapor pressure. Measurement techniques for fuel properties are developed based on unit phenomena for liquid fuel droplets including droplet oscillation …


Functional Structure Of Biomacromolecules In Plant Biomass Using Solid-State Nmr And Dynamic Nuclear Polarization, Alex Kipchirchir Kirui Dec 2021

Functional Structure Of Biomacromolecules In Plant Biomass Using Solid-State Nmr And Dynamic Nuclear Polarization, Alex Kipchirchir Kirui

LSU Doctoral Dissertations

This dissertation summarizes the recent findings on complex biomacromolecules in cell wall of plants and fungi which perform important roles in cell recognition, structural build up, and energy storage. Because of the technical difficulty in characterizing these biomacromolecules, which are often polymorphic and disordered in structure, the functional structure of these biomacromolecules remains elusive. In this dissertation, I present two solid-state nuclear magnetic resonance (ssNMR) and dynamic nuclear polarization (DNP) studies of carbohydrate-rich biosystems: the energy-rich plant biomass and disease-relevant, pathogenic fungi.

First, we have investigated the secondary cell wall of plant biomass which is a carbohydrate-rich biosystem using solid …


Limits On Parameter Estimation Of Quantum Channels, Vishal Katariya Dec 2021

Limits On Parameter Estimation Of Quantum Channels, Vishal Katariya

LSU Doctoral Dissertations

The aim of this thesis is to develop a theoretical framework to study parameter estimation of quantum channels. We begin by describing the classical task of parameter estimation that we build upon. In its most basic form, parameter estimation is the task of obtaining an estimate of an unknown parameter from some experimental data. This experimental data can be seen as a number of samples of a parameterized probability distribution. In general, the goal of such a task is to obtain an estimate of the unknown parameter while minimizing its error.

We study the task of estimating unknown parameters which …


Culture And Economics: A Literature Review, Faith Howard Dec 2021

Culture And Economics: A Literature Review, Faith Howard

Honors Theses

No abstract provided.


The Application Of Deep Learning Algorithms To Pediatric Vascular Anomalies Using A Limited Dataset, Briana I. Robertson Dec 2021

The Application Of Deep Learning Algorithms To Pediatric Vascular Anomalies Using A Limited Dataset, Briana I. Robertson

Honors Theses

No abstract provided.


An Argument For The Second Nuclear Era: Salvaging The Atomic Age In Response To Climate Change, Ian Sager Dec 2021

An Argument For The Second Nuclear Era: Salvaging The Atomic Age In Response To Climate Change, Ian Sager

Honors Theses

No abstract provided.


Ferris Bakes, Ferris Dehart Dec 2021

Ferris Bakes, Ferris Dehart

Honors Theses

No abstract provided.


Revealing The Native Status Of Conyza Bonariensis: Specialization Of Insect Herbivores Associated With Conyza And Erigeron Spp. (Asteraceae) In Louisiana, Texas, And Mississippi, Carlos Wiggins Nov 2021

Revealing The Native Status Of Conyza Bonariensis: Specialization Of Insect Herbivores Associated With Conyza And Erigeron Spp. (Asteraceae) In Louisiana, Texas, And Mississippi, Carlos Wiggins

LSU Master's Theses

Flaxleaf fleabane [Conyza bonariensis (L.) Cronquist] (Asterales: Asteraceae) is an annual herb which grows up to 1.0 m in height and is native to South America. Due to introduction and subsequent development of herbicide resistance, C. bonariensis has become a major agricultural weed in Australia. The purpose of this study was to catalog herbivorous insects associated with local populations of C. bonariensis in Louisiana, Texas and Mississippi in order to establish comparisons with the Australian fauna and identify potential biological control agents. Leaves, roots, stems, and flowers of C. bonariensis were inspected for signs of insects and pathogens. Results …


Memory Forensics Comparison Of Apple M1 And Intel Architecture Using Volatility Framework, Joshua Duke Nov 2021

Memory Forensics Comparison Of Apple M1 And Intel Architecture Using Volatility Framework, Joshua Duke

LSU Master's Theses

Memory forensics allows an investigator to get a full picture of what is occurring on-device at the time that a memory sample is captured and is frequently used to detect and analyze malware. Malicious attacks have evolved from living on disk to having persistence mechanisms in the volatile memory (RAM) of a device and the information that is captured in memory samples contains crucial information for full forensic analysis by cybersecurity professionals. Recently, Apple unveiled computers containing a custom designed system on a chip (SoC) called the M1 that is based on ARM architecture. Our research focused on the differences …


Deep Learning Based Super Resolution Of Gravity Data For Geophysical Exploration, Yi Zhang Nov 2021

Deep Learning Based Super Resolution Of Gravity Data For Geophysical Exploration, Yi Zhang

LSU Master's Theses

Gravity measurement from ground can be obtained by precision gyrostabilized gravimeters. However, land-based gravity measurements can be challenging in many hard-to-reach regions. By contrast, satellite-based gravity measurement is considered to be a very promising for large-scale exploration since it opens up the possibilities for geophysical study of remote regions. However, comparing with the gravity from ground, the resolution and precision of satellite-based gravity measurements is lower, which limits its application for geological explorations. The novel and effective methods in improving the low spatial resolution and precision of satellite-based gravity data are active quest.

Super resolution is used for naming any …


Parallel Coordinates-Based Visualization Of Covid-19 Data, Puja Bhandari Nov 2021

Parallel Coordinates-Based Visualization Of Covid-19 Data, Puja Bhandari

LSU Master's Theses

The number of COVID-19 cases has been continuously increasing worldwide since the beginning of 2020. A lot of efforts have been made in identifying, predicting, and mitigating this deadly virus infection. This requires gaining insight into large collections of the related data, which are multivariate in nature involving many variables/attributes. Here we develop a parallel coordinates system to visualize the COVID-19 data in an interactive manner considering all variables, including location and time. The challenges with this approach include mapping many variables of different types (parallel axes) and occlusion associated with highly cluttered data lines. We adopt several functionalities to …


Growth, Characterization, And Mechanical Testing Of Diamond-Like Carbon Films, Tailei Qi Nov 2021

Growth, Characterization, And Mechanical Testing Of Diamond-Like Carbon Films, Tailei Qi

LSU Master's Theses

The high residual stresses within diamond-like carbon (DLC) films limit its thickness and make the film tend to delaminate from the substrate and be defective on the surface. To address this problem, a new plasma enhanced chemical vapor deposition system (PECVD) was set up to investigate the effects of different film growth parameters on the DLC films, such as chromium doping, gas fluxes, depositing pressures, bias voltages, and depositing times. After the film growth parameters were optimized, this condition was transferred from silicon wafer to SS316 steel plate to deposition of DLC films with some adjustments. Scanning electron microscopy (SEM) …


Characteristics And Causal Factors For The Receptive-Expressive Gap In Typically Developed Spanish-English Adult Bilinguals, Rachael Janelle Javaherian Nov 2021

Characteristics And Causal Factors For The Receptive-Expressive Gap In Typically Developed Spanish-English Adult Bilinguals, Rachael Janelle Javaherian

LSU Master's Theses

A receptive-expressive language gap occurs when a standardized receptive score is statistically greater than an expressive score in either a primary or a second language. In bilingual children, gap studies already exist for determining language impairment. In adults, there are few studies; nevertheless, one needs to distinguish between typical language patterns of bilingualism due to non-pathological loss of L1 skills versus problems resulting from accidents, disease, or age. To this end, the present study attempted to expand findings of studies by Gibson et al. (2012 and 2014) that focused on analysis of the gap and possible factors influencing its existence …


Cfd Simulations Of Macroscopic And Microscopic Multiphase Fluid Flow And Droplet Interaction, Aaron Harrington Nov 2021

Cfd Simulations Of Macroscopic And Microscopic Multiphase Fluid Flow And Droplet Interaction, Aaron Harrington

LSU Master's Theses

Multiphase flow is a complex phenomenon which can be modeled on numerous different length scales, both macroscopically and microscopically. The use of a Euler-Euler model for Computation Fluid Dynamics (CFD) simulations of subcooled boiling phenomena is discussed in detail. The CFD conditions have been set up to mimic previous experimental conditions. A cylindrical vessel with subcooled liquid flow is heated along part of the axial wall of the vessel. A constant heat flux is applied to produce subcooled boiling. We discuss the development of the phase change within the vessel as well as the temperature profile, and validate the results …


Reaction Pathways Of Molecular Growth For Bay-Region Methyl-Substituted Polycyclic Aromatic Hydrocarbons During Supercritical Pyrolysis Of N-Decane, Venkata Sai Krishna Karthik Vutukuru Nov 2021

Reaction Pathways Of Molecular Growth For Bay-Region Methyl-Substituted Polycyclic Aromatic Hydrocarbons During Supercritical Pyrolysis Of N-Decane, Venkata Sai Krishna Karthik Vutukuru

LSU Doctoral Dissertations

Prior to its combustion, fuel for future-highspeed aircraft will experience supercritical conditions, causing the fuel to undergo pyrolytic reactions that lead to the formation of polycyclic aromatic hydrocarbons (PAH), precursors to fuel-line solids that hinder aircraft’s safe operation. Therefore, understanding the formation pathways of PAH under supercritical conditions is important to preventing formation of these solids.

Previous work from our group has shown that n-alkanes are particularly problematic regarding solids formation and that the model fuel n-decane produces an abundance of aliphatics and one- to nine-ring aromatics—many of which are methyl-substituted. Some of these methyl-substituted PAH have their …


Evaluating Consumers’ Perception Of Gluten-Free/Clean-Label Muffins, Vanesa Chicaiza Nov 2021

Evaluating Consumers’ Perception Of Gluten-Free/Clean-Label Muffins, Vanesa Chicaiza

LSU Master's Theses

The gluten-free-natural-ingredient (GF/NCL) product demand is globally increasing and driven by the growing prevalence of celiac-diseases. Nevertheless, the quality of GF product is often inferior compared to wheat-flour counterparts due to the removing of gluten, which, compromises the appearance, structure, and nutritional value. The addition of fiber into GF/NCL products has been considered to improve nutritional values while maintaining quality attributes. According to the US-FDA, a product containing ≥2.5 grams of fiber/serving can be claimed as a “good-source-of-fiber.” However, adding dietary fiber to baked products affects their qualities, and hence possibly lowering product acceptability.

The main objective of this research …


Effects Of Freshwater Input On Nutrient Loading, Toxic Cyanobacteria Bloom Development And Cyanotoxin Production In Lake Pontchartrain Estuary, Louisiana, Callie L. Snow Nov 2021

Effects Of Freshwater Input On Nutrient Loading, Toxic Cyanobacteria Bloom Development And Cyanotoxin Production In Lake Pontchartrain Estuary, Louisiana, Callie L. Snow

LSU Master's Theses

Estuaries in the northern Gulf of Mexico (GoM) are undergoing profound alterations due to changes in climate and implementation of coastal restoration activities and these may lead to the increasing frequency of harmful algal blooms (HABs). The introduction of large volumes of nutrient-rich, fresh Mississippi River water into nutrient-poor Lake Pontchartrain Estuary is known to substantially change the chemistry and ecology of the estuary, and warm temperatures paired with the persistent nutrient loading into the estuary supports the proliferation of potentially toxic cyanobacteria blooms (CyanoHABs). Throughout 2019, a long-term opening of the Bonnet Carré Spillway (BCS), initially from February to …


Examining The Effectiveness Of “Turn Around Don’T Drown”, Chance D. Bryant Nov 2021

Examining The Effectiveness Of “Turn Around Don’T Drown”, Chance D. Bryant

LSU Master's Theses

Extreme heat is the deadliest weather hazard in the U.S. Flooding is the second worst, and flash flooding is the deadliest form of flooding. The nature of these flood deaths contains a human element that deserves greater study. Since 2004, the National Weather Service has attempted to educate the public with its slogan, ``Turn Around Don’t Drown". Vehicle related mortality rates in Texas since 1996 were examined to answer the question of whether ``Turn Around Don’t Drown" has been effective. The slogan has a large footprint on the social media platform Twitter, with most of the Tweets coming from private …


Hemp Microgreen Mineral Content, Cannabinoids, Total Phenolics, And Antioxidants, Cheston T. Schayot Nov 2021

Hemp Microgreen Mineral Content, Cannabinoids, Total Phenolics, And Antioxidants, Cheston T. Schayot

LSU Master's Theses

Hemp (Cannabis sativa) L. microgreens were grown to 7 and 12 days with and without supplemental lighting and/or fertilizer. The principal macronutrient found in hemp microgreens was nitrogen (N), followed by potassium (K), phosphorus (P), magnesium (Mg), calcium (Ca), and sulfur (S). The principal micronutrient found in hemp microgreens was iron (Fe), followed by manganese (Mn), zinc (Zn), boron (B), and copper (Cu). Hemp microgreens were similar to other commonly grown microgreen species in minerals except for P and Mg, where they could potentially be an excellent source, and Zn, where they fell below previously reported amounts. The …


An Evaluation Of The Break Up With Salt Community-Based Hypertension Education Program, Helena L. Salgado Nov 2021

An Evaluation Of The Break Up With Salt Community-Based Hypertension Education Program, Helena L. Salgado

LSU Master's Theses

Introduction: Hypertension is a primary risk factor for heart disease and stroke, and contributes to renal disease, premature death, and disability. More recently, hypertension has also been identified as a risk factor for serious symptoms or as an underlying cause of death from Covid-19. Break up with salt (BUWS) is a 4-session, community-based nutrition education program of the LSU AgCenter, developed in response to the Covid-19 pandemic, to help Louisiana’s adults prevent or mange hypertension. The BUWS curriculum focuses on the DASH diet, healthy food selection and preparation skills, and physical activity and stress management. BUWS was piloted in a …


Response Of Roseau Cane (Phragmites Australis) To Two Biotic Stresses: Hyalopterus Pruni And Bipolaris Yamadae, Heather E. Cizek Nov 2021

Response Of Roseau Cane (Phragmites Australis) To Two Biotic Stresses: Hyalopterus Pruni And Bipolaris Yamadae, Heather E. Cizek

LSU Master's Theses

Roseau cane (Phragmites australis) is considered an invasive plant because of its ability to replace native plant species. However, in Louisiana it plays an important role protecting coastal infrastructure and being part of the marsh ecosystem in the lower Mississippi River Delta. In recent years, Roseau cane has been affected by a die-off, a problem that has also been reported in some European countries. Possible biotic and abiotic factors that have been associated with the die-off include scale insects, climate change, pollution, salinity levels, and pathogens.

In this research, the individual and combined effect of a foliar disease …


The Rural Road: A Phenomenological Study Exploring Advanced Placement Coursework And College Readiness In Louisiana, Willie Adelaide Louviere Nov 2021

The Rural Road: A Phenomenological Study Exploring Advanced Placement Coursework And College Readiness In Louisiana, Willie Adelaide Louviere

LSU Doctoral Dissertations

Rigorous coursework is one of the necessary staples in establishing college readiness. Rural districts are much less likely to offer advanced coursework opportunities to students. The purpose of this qualitative study is to examine the equitable access to advanced coursework opportunities (Advanced Placement) provided to rural students (in-person and distance learning) in public rural high schools in Louisiana. Access to advanced coursework (Advanced Placement, Dual Enrollment, etc.) serves as an indicator of college readiness; however, a substantial gap exists in providing the programs to underserved student populations. Rural students face significant barriers that can hinder their ability to thrive on …


The Origin And The Evolution Of The Double Bass, Patrick James Lavergne Nov 2021

The Origin And The Evolution Of The Double Bass, Patrick James Lavergne

LSU Doctoral Dissertations

This dissertation will trace the double bass from the 16th century to the 21st century. The double bass is the largest and lowest pitched member of the string family. The members of the string family are the violin, viola, cello, and the double bass. The pitch of the double bass sounds one octave lower than the written pitch. The double bass is sometimes called the contrabass, string bass, upright bass, or bass fiddle. It is used in different genres of music such as classical, jazz, blues, bluegrass, country & western, and even rock.


Improving The Deployment Of Insecticidal Seed Treatments In Louisiana Rice In Accordance With Integrated Pest Management, Megan Marie Mulcahy Nov 2021

Improving The Deployment Of Insecticidal Seed Treatments In Louisiana Rice In Accordance With Integrated Pest Management, Megan Marie Mulcahy

LSU Doctoral Dissertations

Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae), is the most destructive insect pest of rice in the United States. Lissorhoptrus oryzophilus larvae feed on rice roots, reducing yields by up to 25 %. Lepidopteran stem borers, in the family Crambidae, are also economically important pests of rice in Louisiana.

Currently, insecticidal seed treatments are used throughout the U.S. Mid-south rice industry to prophylactically control L. oryzophilus. Chlorantraniliprole seed treatments are also effective against stem borers. Thus, insecticidal seed treatments are used on >80 % of Louisiana rice acreage. Although seed treatments reduce damage inflicted by these pests, they are applied preventatively …


Asynchronous, Distributed Optical Mutual Exclusion And Applications, Ahmed Bahaael Mansour Nov 2021

Asynchronous, Distributed Optical Mutual Exclusion And Applications, Ahmed Bahaael Mansour

LSU Doctoral Dissertations

Silicon photonics have drawn much recent interest in the setting of intra-chip andmodule communication. In this dissertation, we address a fundamental computationalproblem, mutual exclusion, in the setting of optical interconnects. As a main result, wepropose an optical network and an algorithm for it to distribute a token (shared resource)mutually exclusively among a set ofnprocessing elements. Following a request, the tokenis granted in constant amortized time andO(n) worst case time; this assumes constantpropagation time for light within the chip. Additionally, the distribution of tokens is fair,ensuring that no token request is denied more thann−1 times in succession; this is thebest possible. …


An Investigation Examining The Closing Of The Achievement Gap In Louisiana With The Ngss, George Cage Nov 2021

An Investigation Examining The Closing Of The Achievement Gap In Louisiana With The Ngss, George Cage

LSU Doctoral Dissertations

The purpose of this study was to investigate the Next Generation Science Standards (NGSS) and its implications of being a curricular and pedagogical intervention in terms of narrowing the achievement gap in science education for Children of Color. In using the explanatory mixed methods design, standardized test data and one-on-one interviews were examined to assess the effectiveness and impact of the NGSS’ implementation in the state of Louisiana. This study utilized student performance results from the LEAP 2025 to conduct a statistical analysis that measured trends in performance by Children of Color, specifically Black students, before and after the implementation …


Non-Adiabatic Excited State Molecular Dynamics Using Ehrenfest And Modulated X-Ray Absorption In Titania, Alexander Matthew Meyer Nov 2021

Non-Adiabatic Excited State Molecular Dynamics Using Ehrenfest And Modulated X-Ray Absorption In Titania, Alexander Matthew Meyer

LSU Doctoral Dissertations

This dissertation contains two separate sections aside from an introduction (Chapter 1): theory and methods (Chapter 2), time dependent density functional theory with Ehrenfest for excited state lifetimes in materials (Chapter 3), and simulated field modulated X-ray absorption in titania (Chapter 4).

Excited state lifetime in insulators and semiconductors can be difficult to compute using quantum chemistry due to their dense excited states. Non-radiative decay in these materials requires the use of non-adiabatic effects to dissipate energy through the means of electron-nuclear coupling such as coherent phonon generation. One method of approaching this challenge in these materials is using Ehrenfest …


Regional Expansion And Evaluation Of Potential Chemical Control For Invasive Apple Snails (Pomacea Maculata) In Southwest Louisiana, Julian M. Lucero Nov 2021

Regional Expansion And Evaluation Of Potential Chemical Control For Invasive Apple Snails (Pomacea Maculata) In Southwest Louisiana, Julian M. Lucero

LSU Master's Theses

The integration of monitoring and chemical control is an efficient strategy for managing invasive apple snails, Pomacea maculata, in the rice (Oryza sativa L.) and crawfish systems of southwest Louisiana. However, their current distribution, expansion rates, and susceptibility to chemical control methods in this area are not well known. This study evaluated the expansion of P. maculata in southwest Louisiana and assessed potential chemical control for P. maculata among toxicity assays using various application rates. The effects of potential chemical control were also assessed on a non-target species, the red swamp crawfish (Procambarus clarkii). P. maculata …


Numerical Investigation Of The Impact Of Distortion On The Hydrodynamics In The Lower Mississippi River Physical Model (Lmrpm), Ali Heidarizhaleh Nov 2021

Numerical Investigation Of The Impact Of Distortion On The Hydrodynamics In The Lower Mississippi River Physical Model (Lmrpm), Ali Heidarizhaleh

LSU Doctoral Dissertations

The Lower Mississippi River Physical Model (LMRPM) is a distorted-scale, 1:6000 horizontal and 1:400 vertical, movable-bed model that is being used to complement ongoing numerical and field studies directed at studying how non-cohesive sediment transport will be impacted by future changes in relative sea level rise and river discharges, as well various management strategies, such as river sediment diversions, in the lower ~190 miles of the Mississippi River The LMRPM was designed using Froude number (Fr) similarity between the prototype and the model, while the flow Reynolds number is relaxed, but determined to be high enough to ensure rough turbulent …


Application Of Gas-Assisted Gravity Drainage (Gagd) Process For Enhancing Recovery From Unconventional Resources, Muzher Al Musabeh Nov 2021

Application Of Gas-Assisted Gravity Drainage (Gagd) Process For Enhancing Recovery From Unconventional Resources, Muzher Al Musabeh

LSU Doctoral Dissertations

The oil recovery with hydraulic fracturing has played an important role in hydrocarbon production and energy support last decade from unconventional resources. Characteristically, the significant production decline and low recovery factors from these reservoirs triggered the need for new EOR techniques to compensate for the decline and help sustain the production. In this study, an experimental investigation of the Gas-Assisted Gravity Drainage (GAGD) process in the presence of fractures as EOR process was conducted using Nitrogen (N2) and Carbon Dioxide (CO2) in Berea Sandstone (BSS) and Tuscaloosa Marine Shale (TMS). Core flooding and EOR experiments were used to determine the …