Digital Commons Network^™

Coupled Pore-To-Continuum Multiscale Modeling Of Dynamic Particle Filtration Processes In Porous Media, John Rayner Blears

LSU Doctoral Dissertations

Modeling particle transport and retention in porous media is important in fields such as hydrocarbon extraction, groundwater filtration, and membrane separation. While the continuum-scale (>1 m) is usually of practical interest, pore-scale (1-100 μm) dynamics govern the transport and retention of particles. Therefore, accurate modeling of continuum-scale behavior requires an effective incorporation of pore-scale dynamics. Due to current computational limits however, the large spatial and temporal discrepancies of these scales prohibit modeling an entire continuum-scale system as a single pore-scale model. Even if a pore-scale model could incorporate every pore contained in a continuum-scale system, an upscaling scheme that …

Characterizing The Roles Of Nuclear Proteins Dbc1, G9a, And Glp In Adipocyte Function And Metabolic Health, Ashley Ann Able

LSU Doctoral Dissertations

Obesity is a metabolic disorder characterized by excess energy storage in adipose tissue and it increases the risk for Type 2 diabetes. Impaired or altered adipocyte function during obesity can contribute to metabolic dysfunction. DBC1 (deleted in breast cancer 1) and EHMTs 1 and 2 (euchromatic histone lysine methyltransferases 1 and 2) have been shown to have a role in fat cell development and function. DBC1 is typically localized in the nucleus and can regulate a variety of epigenetic modifiers, transcription factors, and nuclear receptors. EHMTs 1 and 2, also known respectively as GLP and G9a, were initially classified as …

Unidirectional And Nonreciprocal Nanophotonic Devices Based On Graphene And Magneto-Optical Materials, Vahid Foroughi Nezhad

LSU Doctoral Dissertations

In this dissertation, we first introduce compact tunable spatial mode converters for graphene parallel plate (GPP) waveguides. The converters are reciprocal and based on spatial modulation of graphene’s conductivity. The wavelength of operation of the mode converters is tunable in the mid-infrared wavelength range by adjusting the chemical potential of a strip on one of the graphene layers of the GPP waveguides. We also introduce optical diodes for GPP waveguides based on a spatial mode converter and a coupler, which consists of a single layer of graphene placed in the middle between the two plates of two GPP waveguides. \par …

Intrusive Advising And Retention Practices In A College Of Agriculture: A Case Study Of First-Year Student Experiences, Amanda Martin

LSU Doctoral Dissertations

The purpose of this qualitative case study was to explore the perceptions of first-year students who experienced intrusive advising and retention initiatives in the College of Agriculture at Louisiana State University (LSU). Research participants consisted of 20 first-year students enrolled in the college in the fall of 2018. One-on-one, face-to-face interviews with first-year students were conducted to gain insight and understand student experiences with intrusive advising and retention initiatives within the College of Agriculture. College student retention and factors that contribute to understanding retention have been extensively studied (Astin, 1993; Braxton, Hirschy, & McClendon, 2004; Habley, Bloom, & Robbins, 2012; …

Exploring Occupant Behavioral Intentions In Immersive Virtual Environment To Enhance The Design And Engineering Of Sustainable Buildings, Sanaz Saeidi

LSU Doctoral Dissertations

Accurately simulating occupant behavior is essential to improve our understanding about the future energy performance of the buildings. To date, most of the information related to the occupancy behaviors has been gathered through field observations and/or performing experiments within the lab environments. Even though these common data collection methods are effective and reliable for the existing buildings, using such data to project occupant behaviors in other contexts is likely to lead to uncertainties. The most significant theoretical achievement of this dissertation was to provide the future building occupants with thermal experience of non-physically existent environments. In this dissertation occupant behavior …

Development Of A Tunable Platform For The Study Of Geomacromolecular Matrices Using Controlled Radical Polymerization, Arjun Pandey

LSU Doctoral Dissertations

Soil is an important environmental component, and the study of soil processes have many practical implications such as improvement in agriculture, mitigation of climate change etc. The widespread use of Agricultural Chemicals (ACs) in modern agriculture has resulted in adverse effects in environment and human health mostly through contamination into food and water sources. Study of fate, bioavailability, and transport of ACs involves molecular level understanding of their interactions with soil. This can be challenging due to complex and heterogeneous nature of soil. One common approach used is the correlation of macroscopic properties of soil, (e.g. sorption) with empirical parameters …

Visualization And Quantitation Of Radioiodine Distribution In Silver Zeolite Cartridges, Daniel Dimarco

LSU Master's Theses

Iodine 131 is a major fission product released during a nuclear incident. This isotope provides a serious health hazard for humans and the environment, therefore nuclear power plants must monitor releases using air sampling. The air sampling is accomplished using air filter cartridges using silver zeolite as a filter media. During an emergency situation, silver zeolite is useful for its affinity to I-131 without adsorbing other radioactive gases. After leaving the plume, these cartridges are counted in a low background area. This measurement does not take into account the distribution of radioiodine in the cartridge. This study explores two methods …

Purification Of Tag-Free Chlamydia Trachomatis Scc4 For Structural Studies Using Sarkosyl-Assisted On-Column Complex Dissociation, Thilini O. Ukwaththage, Octavia Y. Goodwin, Abigael C. Songok, Alexa M. Tafaro, Li Shen, Megan A. Macnaughtan

Faculty Publications

Copyright © 2019 American Chemical Society. Chlamydia trachomatis is an obligate intracellular bacterial pathogen that causes the most common sexually transmitted bacterial disease in the world. The bacterium has a unique biphasic developmental cycle with a type III secretion system (T3SS) to invade host cells. Scc4 is a class I T3SS chaperone forming a heterodimer complex with Scc1 to chaperone the essential virulence effector, CopN. Scc4 also functions as an RNA polymerase binding protein to regulate σ66-dependent transcription. Aggregation and low solubility of 6X-histidine-tagged Scc4 and the insolubility of 6X-histidine and FLAG-tagged Scc1 expressed in Escherichia coli have hindered the …

Reproductive Parameters And Female Breeding Season Survival Of Rio Grande Wild Turkeys In South Central Texas, Jacob White

LSU Master's Theses

Historically, Rio Grande wild turkeys in south central Texas have been at lower densities than other portions of the state. Within the Oak-Prairie Wildlife District of Texas, Rio Grande wild turkey regulatory restrictions are different for counties in the eastern and western portions of the ecoregion. Due to perceived increases in turkey density in the eastern portion of the ecoregion (hereafter 1-bird zone), Texas Parks and Wildlife Department (TPWD) considered increasing the bag limit to match counties in the western portion of the district (hereafter 4-bird zone) in order to increase hunting opportunities. However, if regulatory changes are to be …

Ultrafast And Real-Time Dynamics Of Nanomaterials Studied By Advanced Spectroscopic Techniques, Jeewan Chaminda Ranasinghe

LSU Doctoral Dissertations

Ultrafast and nonlinear spectroscopies are used to study excited-state dynamics and monitor real-time growth dynamics of different types of nanomaterials. In the first study, the growth dynamics of colloidal gold-silver core-shell nanoparticles are studied using in situ second harmonic generation and extinction spectroscopy. The growth lifetimes are studied under different reaction conditions, resulting in different silver shell thicknesses, with spectral comparisons to finite-difference time-domain calculations. The results are consistent with a three-step growth process. During the first step of the nanoparticle growth reaction, rough and uneven surfaces are formed rapidly giving rise to plasmonic hot spots with corresponding broad, red-shifted …

Turn-On Near-Infrared Fluorescent Sensors For Selective Monitoring Of Kinase Activity, Gerard Thomas Ducharme

LSU Doctoral Dissertations

Reliable and selective detection of specific biopolymers is critical in a broad range of biomedical and technological areas, including availability of simple and efficient point-of-care-compatible systems for the detection of prognostic, pharmacodynamic and predictive biomarkers. Monitoring epidermal growth factor receptor (EGFR) tyrosine kinase is of major significance due to its link to many epithelial cancers. This task is complicated by the high rate of mutation occurring in patients treated with kinase inhibitors. This dissertation describes a conceptually novel design and synthesis of turn-on near-infrared fluorescent sensors for selective and sensitive detection of EGFR. The fluorescent signal generation mechanism is based …

The Importance Of Self-Monitoring For Behavior Change In Youth: Findings From The Switch® School Wellness Feasibility Study, Gabriella M. Mcloughlin, Richard R. Rosenkranz, Joey A. Lee, Maren M. Wolff, Senlin Chen, David A. Dzewaltowski, Spyridoula Vazou, Lorraine Lanningham-Foster, Douglas A. Gentile, Marisa S. Rosen, Gregory J. Welk

Faculty Publications

School Wellness Integration Targeting Child Health (SWITCH®) is a school wellness implementation initiative focused on building capacity for schools to plan and coordinate wellness programming. Grounded in Social Cognitive Theory (SCT), the purpose of this study was to evaluate the utility of the web-based, self-regulation system on physical activity (PA) behavior outcomes. At pre-test and post-test, students in SWITCH® schools (n = 8) completed the online Youth Activity Profile (YAP) to assess PA and sedentary behavior (SB). Students (n = 513) were categorized into high or low self-monitoring groups (using a median split) based on their use of the web-based …

Pacts 1.0: A Crowdsourced Reporting Standard For Paleoclimate Data, Kristine Delong

Faculty Publications

The progress of science is tied to the standardization of measurements, instruments, and data. This is especially true in the Big Data age, where analyzing large data volumes critically hinges on the data being standardized. Accordingly, the lack of community-sanctioned data standards in paleoclimatology has largely precluded the benefits of Big Data advances in the field. Building upon recent efforts to standardize the format and terminology of paleoclimate data, this article describes the Paleoclimate Community reporTing Standard (PaCTS), a crowdsourced reporting standard for such data. PaCTS captures which information should be included when reporting paleoclimate data, with the goal of …

Louisiana Agriculture Fall, 2019, Lsu Agcenter

Louisiana Agriculture

No abstract provided.

Lsu Research Fall 2019, Louisiana State University And Agricultural And Mechanical College

Research Magazine

LSU Research is published annually by the Office of Research & Economic Development, Louisiana State University.

Fall 2019 Catalog, Lsu Press

LSU Press Seasonal Catalogs

No abstract provided.

Anisotropy Of The Effective Toughness Of Layered Media, S. Brach, M. Z. Hossain, B. Bourdin, K. Bhattacharya

Faculty Publications

This continues the study of the effective toughness of layered materials started in Hossain et al. (2014) and Hsueh et al. (2018), with a focus on anisotropy. We use the phase-field model and the surfing boundary condition to propagate a crack macroscopically at various angles to the layers. We study two idealized situations, the first where the elastic modulus is uniform while the toughness alternates and a second where the toughness is uniform and the elastic modulus alternates. We find that in the first case of toughness heterogeneity the effective toughness displays ‘anomalous isotropy’ in that it is independent of …

Intensive Livestock Production Causing Antibiotic Pollution In The Yinma River Of Northeast China, Hanyu Ju, Sijia Li, Y. Jun Xu, Guangxin Zhang, Jiquan Zhang

Faculty Publications

Antibiotics are increasingly used in livestock production in rural China, raising concerns over pollution and health risk in countryside waterways. The Yinma River Basin in China's far northeast is an agriculture-dominated area mixed with a densely populated province capitol city, providing a suitable area for investigating the influence of a typical land use mix in Northeast China on riverine antibiotic levels and transport. In this study, we sampled water along the Yinma River from upstream to downstream in a wet and a dry season and analyzed the samples for two popularly used antibiotics, ciprofloxacin (CIP) and norfloxacin (NOR). The goal …

Postbreeding Habitat Use By Golden-Cheeked Warblers (Setophaga Chrysoparia), Melanie R. Colón, Mark R. Hutchinson, Ashley M. Long, Gary Voelker, Michael L. Morrison

Faculty Publications

The period following breeding but prior to migration is an important, though understudied, component of the avian annual life cycle. We quantified habitat use by endangered Golden-cheeked Warblers (Setophaga chrysoparia) during the postbreeding period in Golden-cheeked Warbler breeding habitat (i.e., oak-juniper [Quercus-Juniperus] woodlands) predominated by Texas oak (Quercus buckleyi) or post oak (Q. stellata), as well as in immediately adjacent oak woodland, oak savanna, and riparian vegetation not usually associated with breeding activity for this species. Most (87%) of the Golden-cheeked Warblers we detected were in oak-juniper woodlands, especially in Texas oak sites, but we also detected warblers in each …

Microfluidic Isolation Of Tumor Cells Or Other Rare Cells From Whole Blood Or Other Liquids, Steve A. Soper, Michael C. Murphy, June Feng, Robin L. Mccarley, Andre A. Adams

College of Science Patents

Microdevices are disclosed to efficiently, accurately, and rapidly isolate and enumerate rare cells, such as circulating tumor cells, from liquids such as whole blood. The system employs multiple parallel meandering channels having a width on the order of 1-2 cell diameters. The microdevices can be produced at low-cost, may readily be automated, and in many instances may be used without pre-processing of the sample. They may be used to isolate and enumerate rare cells, including for example the detection and diagnosis of cancers, cancer staging, or evaluating the effectiveness of a therapeutic intervention, or detecting pathogenic bacteria. The device may …

Taboo 18:1 - Full Issue, Taboo Journal

Taboo: The Journal of Culture and Education

No abstract provided.

A Seat At The Table: Womanist Narratives Of Black Mothers In Doctoral Programs, Juhanna Rogers, Alexis Mclean, Marcelle Mentor

Taboo: The Journal of Culture and Education

No abstract provided.

Overcoming Imposter Syndrome And Stereotype Threat: Reconceptualizing The Definition Of A Scholar, Callie Womble Edwards

Taboo: The Journal of Culture and Education

No abstract provided.

Microfluidic Isolation Of Tumor Cells Or Other Rare Cells From Whole Blood Or Other Liquids, Steve A. Soper, Michael C. Murphy, June Feng Schneider, Robin L. Mccarley, Andre A. Adams

College of Science Patents

Microdevices are disclosed to efficiently, accurately, and rapidly isolate and enumerate rare cells, such as circulating tumor cells, from liquids such as whole blood. The system employs multiple parallel meandering channels having a width on the order of 1-2 cell diameters. The microdevices can be produced at low-cost, may readily be automated, and in many instances may be used without pre-processing of the sample. They may be used to isolate and enumerate rare cells, including for example the detection and diagnosis of cancers, cancer staging, or evaluating the effectiveness of a therapeutic intervention, or detecting pathogenic bacteria. The device may …

Supercritical Co2 Foam Enhanced Oil Recovery: From Mechanistic Model Fit To Lab Experiments To Field-Scale Evaluation, Mohammad Izadi

LSU Doctoral Dissertations

This study investigates how a mechanistic foam modeling approach based on bubble population balance is applied to a series of laboratory experimental data of a supercritical CO₂ foam in reservoir conditions to extract model parameters (topic 1). The model with model parameters determined from the fit is then used to estimate how far fine-textured strong foam can propagate into the reservoir, before turning into coarse-textured weak foam and before being segregated by gravity (topic 2). With the help of mechanistic model, a possible range of gas mobility for supercritical CO₂ foam is calculated and the resulting gas-phase mobility …

Fisetin, A 3,7,3',4'-Tetrahydroxyflavone Inhibits The Pi3k/Akt/Mtor And Mapk Pathways And Ameliorates Psoriasis Pathology In 2d And 3d Organotypic Human Inflammatory Skin Models, Jean Christopher Chamcheu, Stephane Esnault, Vaqar M. Adhami, Andrea L. Noll, Sergette Banang-Mbeumi, Tithi Roy, Sitanshu S. Singh, Shile Huang, Konstantin G. Kousoulas, Hasan Mukhtar

Faculty Publications

Psoriasis is a chronic immune-mediated skin disease that involves the interaction of immune and skin cells, and is characterized by cytokine-driven epidermal hyperplasia, deviant differentiation, inflammation, and angiogenesis. Because the available treatments for psoriasis have significant limitations, dietary products are potential natural sources of therapeutic molecules, which can repair the molecular defects associated with psoriasis and could possibly be developed for its management. Fisetin (3,7,3',4'-tetrahydroxyflavone), a phytochemical naturally found in pigmented fruits and vegetables, has demonstrated proapoptotic and antioxidant effects in several malignancies. This study utilized biochemical, cellular, pharmacological, and tissue engineering tools to characterize the effects of fisetin on …

Silicon Fertilization In Rice And Wheat: Dynamics With Trace Elements And Effect Of Silicate Slag Granular Size On The Release Pattern Of Monosilicic Acid In Soil, Wooiklee S. Paye

LSU Doctoral Dissertations

Studies were conducted to evaluate the impact of silicon (Si) fertilization on the uptake of harmful trace elements in Louisiana rice production system, and document the effect of silicate slag granular size on its ability to supply Si in wheat. The influence of silicate slag and lime on the uptake and translocation of harmful trace elements in rice grain was determined. Results showed that both slag and lime had similar effects on pH at five of the nine sites investigated. Soil Si was significantly (P <0.001) increased with application of silicate slag at all sites. Lime and silicate slag had no effect on the concentration of trace elements in soil. However, increasing Si rates were negatively correlated with arsenic (As) and cadmium (Cd) concentration in rice grain. The release pattern of monosilicic acid (H₄SiO₄) from wollastonite and silicate slag was compared in a wheat greenhouse …

Sequence-Defined Ionic Peptoid Block Copolymers: Synthesis And Solution Self-Assembly, Garrett Leigh Sternhagen

LSU Doctoral Dissertations

This work covers efforts to develop a peptoid-based model system for systematically studying the role of ionic functional groups in determining the structure of ionic block copolymer (BCP) self-assemblies in water. A key challenge in the study of polyelectrolytes is the lack of synthetic control over the location of ionic monomers along a polymer chain. We developed a model system based on sequence-defined ionic peptoid BCPs having discrete chain length and precisely positioned ionic monomers along the chain to specifically address this issue. In Chapter 1, synthetic strategies to access well-defined polypeptoids and their application in BCP synthesis are reviewed. …

Effect Of Surfactant, Oil:Water Ratio And Temperature On The Rheology Of Emulsion-Suspension Complex Fluids: Implications For Oil-Based Drilling Fluids, Gilles Landry Numkam

LSU Doctoral Dissertations

Drilling fluids are non-Newtonian mixtures that play a critical role in the timely and successful completion of oil and gas wells. In the particular case of offshore operations, proper design of drilling fluids is of paramount importance in the constant quest to lower break-even prices. Most downhole problems are directly or in-directly related to the rheological and physical properties of drilling fluids, thereby calling for a better understanding of the underlying changes of these properties with respect to drilling fluid composition and external conditions.

The current stance in the design of drilling fluids involves the selection of components and their …

Preface, Hui-Hsiung Kuo, George Yin

Communications on Stochastic Analysis

No abstract provided.