Digital Commons Network^™

Modeling And Numerical Analysis Of The Cholesteric Landau-De Gennes Model, Andrew L. Hicks

LSU Doctoral Dissertations

This thesis gives an analysis of modeling and numerical issues in the Landau-de Gennes (LdG) model of nematic liquid crystals (LCs) with cholesteric effects. We derive various time-step restrictions for a (weighted) $L^2$ gradient flow scheme to be energy decreasing. Furthermore, we prove a mesh size restriction, for finite element discretizations, that is critical to avoid spurious numerical artifacts in discrete minimizers that is not well-known in the LC literature, particularly when simulating cholesteric LCs that exhibit ``twist''. Furthermore, we perform a computational exploration of the model and present several numerical simulations in 3-D, on both slab geometries and spherical …

Analysis And Improvement Of Efficient Charge Recovery Logic Adiabatic Circuits, William Morell

LSU Doctoral Dissertations

Power consumption has been an ever-present concern since the dawn of electronic computing. Every operation that a device performs consumes some amount of energy and as the demand for computation increases, both in scale and ubiquity, reducing this energy loss becomes more important. While modern devices are orders of magnitude more efficient than their ancestors on a per-operation basis, they are increasingly used in more resource constrained applications. Tiny, Internet of Things (IoT) machines are prevalent these days and demanded to perform data collection and analysis at all hours of the day for days at a time on small battery. …

Interactive Effects Of Co2, Temperature, And Nitrate Limitation On The Growth And Physiology Of Marine Cyanobacterium Synechococcus Sp. Ccmp 1334, Alyssa K. Sharbaugh

LSU Master's Theses

The marine cyanobacterium Synechococcus sp. CCMP 1334 was grown in a continuous culture system on a 12:12 h light:dark cycle at all combinations of low and high pCO2 (400 and 1000 ppmv, respectively), nitrate availability (nitrate-limited and nutrient-replete conditions), and temperatures of 21°C, 24°C, 28°C, 32°C, and 35°C. The maximum median nutrient-replete growth rate was ~1.15 d−1 at 32 –35°C. Median growth rates at 1000 ppmv pCO2 were higher than those at 400 ppmv at all temperatures, but most of the differences were statistically insignificant. Carbon:nitrogen ratios were independent of pCO2 at a fixed relative growth rate but decreased with …

¡Mujeres Chéveres! – Cool Women!, Hernan A. Gonzales Mejia

LSU Master's Theses

¡MUJERES CHÉVERES! – Cool Women! is a body of work and writing that looks into the history of feminism and analyzes the activism of Colombian women, highlighting their resilience and spirit. Policarpa Salavarrieta, Maria Cano, Madre Laura Montoya, and Adriana Ocampo are a few examples of Colombian women’s contributions to social movements and gender equality. Movements like “Estamos Listas” in Medellín are discussed for their role in advocating for women’s rights and societal change.

As a self-identified feminist male, this body of work, draws from my upbringing among influential women to investigate the societal roles of Colombian women. This …

Supply And Distribution Of Flow And Sediment In River And Delta System, Kazi M. Sadid

LSU Doctoral Dissertations

River deltas are valuable ecosystems that have been essential in supporting human populations and the economy across the world for centuries. However, climate change and human activities have caused significant land loss in delta areas. A prime example of a region that has suffered severe land loss is Louisiana in the United States. Coastal restoration is therefore essential for the livelihoods of its residents. To address this issue, the Lower Mississippi River (LMR) channel bar has been regularly dredged to rebuild degraded marsh areas. Additionally, sediment diversions off LMR have been designed to build marsh areas sustainably. This dissertation investigates …

Gut Microbiota And Blood Metabolites Related To Fiber Intake And Type 2 Diabetes, Zheng Wang, Brandilyn A. Peters, Bing Yu, Megan L. Grove, Tao Wang, Xiaonan Xue, Bharat Thyagarajan, Martha L. Daviglus, Eric Boerwinkle, Gang Hu, Yasmin Mossavar-Rahmani, Carmen R. Isasi, Rob Knight, Robert D. Burk, Robert C. Kaplan, Qibin Qi

Population and Public Health Science Faculty Publications

BACKGROUND: Consistent evidence suggests diabetes-protective effects of dietary fiber intake. However, the underlying mechanisms, particularly the role of gut microbiota and host circulating metabolites, are not fully understood. We aimed to investigate gut microbiota and circulating metabolites associated with dietary fiber intake and their relationships with type 2 diabetes (T2D). METHODS: This study included up to 11 394 participants from the HCHS/SOL (Hispanic Community Health Study/Study of Latinos). Diet was assessed with two 24-hour dietary recalls at baseline. We examined associations of dietary fiber intake with gut microbiome measured by shotgun metagenomics (350 species/85 genera and 1958 enzymes; n=2992 at …

After The Storm: Associations Of Hope And Post-Traumatic Growth In Hurricane Ida Recovery In Younger And Older Adults, Piper J. Bordes

LSU Master's Theses

In recent years, there has been an increase in interest among researchers to understand the impact of severe weather events on measures of health and well-being across the adult lifespan. Previous studies have shown that older age and state hope may act as protective factors that are associated with reduced mental health impacts of hurricanes and flooding. While most prior studies have examined the physical and mental health impacts of severe weather events, very few studies have examined post-traumatic growth in a disaster context, and virtually no prior studies have directly compared younger and older adult samples. Therefore, the present …

The Power Of Social Capital: A Case Study Of The Louisiana State University Agcenter’S Agricultural Leadership Development Program, Andrew Schade

LSU Master's Theses

The Louisiana State University Agricultural Center’s Agricultural Leadership Development Program (LSU AgCenter ALDP) is a two-year nonformal education program for participants connected to various aspects of the agricultural and natural resources sectors. The purpose of the study was to describe the perspectives of graduates of the LSU AgCenter ALDP since 2005 regarding their self-reported outcomes after completing the program. The study used a qualitative, instrumental case study design, based on 12 semi-structured interviews, observation, and document analysis. The study employed adult learning theory and social capital theory as the theoretical frameworks to understand the impact of the program on participants. …

Role Of Electronegativity In Environmentally Persistent Free Radicals (Epfrs) Formation On Zno, Syed Monjur Ahmed, Reuben A. Oumnov, Orhan Kizilkaya, Randall W. Hall, Phillip T. Sprunger, Robert L. Cook

Faculty Publications

Environmentally persistent free radicals (EPFRs), a group of emerging pollutants, have significantly longer lifetimes than typical free radicals. EPFRs form by the adsorption of organic precursors on a transition metal oxide (TMO) surface involving electron charge transfer between the organic and TMO. In this paper, dihalogenated benzenes were incorporated to study the role of electronegativity in the electron transfer process to obtain a fundamental knowledge of EPFR formation mechanism on ZnO. Upon chemisorption on ZnO nanoparticles at 250 °C, electron paramagnetic resonance (EPR) confirms the formation of oxygen adjacent carbon-centered organic free radicals with concentrations between 10¹⁶ and 10 …

17O-Excess In Tropical Cyclones Reflects Local Rain Re-Evaporation More Than Moisture Source Conditions, Chijun Sun, Timothy Shanahan, Shaoneng He, Adriana Bailey, Jesse Nusbaumer, Jun Hu, Aubrey Hillman, Erika Ornouski, Jacob Warner, Kristine Delong

Faculty Publications

17O-excess is a relatively new water isotope parameter that could potentially provide useful information about the hydrological cycle. Previous works focusing on 17O-excess in polar regions suggest that it primarily tracks moisture source relative humidity, but little is known about how to interpret 17O-excess data in lower latitudes. Here we present quasi-hourly triple oxygen isotope data of precipitation collected from two tropical cyclones in Texas and Louisiana in 2020 to understand the impacts of environmental and meteorological processes on the 17O-excess of low-to mid-latitude precipitation. We find that at both hourly timescales and the event scale, 17O-excess is strongly correlated …

Coming To America: Exploring The Cross-Cultural Adaptation Of African International Students At A Pwi And Hbcu In The U.S. South, Adwoa F. Baffour

LSU Master's Theses

African international students undergo significant challenges in their cross-cultural adaption in the United States. The cross-cultural adaptation of international students, particularly those from African countries, in a new environment assumes paramount importance due to its direct correlation with their mental and social well-being (Shafaei and Razak, 2016). Furthermore, the mental and social well-being of African international students attending universities in the southern United States has a profound impact on their overall success and overall college experience. This underscores the urgent need for future research to delve deeper into the cross-cultural adaptation experiences of African international students at United States universities, …

Her Seat At The Table: A Phenomenological Study Exploring The Lived Experiences Of Black Women Education Policymakers, Vickey R. Silas

LSU Doctoral Dissertations

ABSTRACT

This transcendental phenomenological study explored the lived experiences of Black women leaders as education policymakers to understand the essence of their journey to leadership positions and the impetus behind their decision-making. Despite progress, Black women remain marginalized and underrepresented in policymaking leadership roles and decision-making spaces (Griffin et. al, 2013). They face challenges that are intersectional like gender and race. My research question was what are the lived experiences of Black women education policymakers and how do these experiences impact their decision-making? While employing a transcendental phenomenological approach, I acknowledged my biases through reflexivity and bracketed them while also …

Sensor Analytics For Subsea Pipeline And Cable Inspection: A Review, Connor R. Vincent

LSU Master's Theses

Submarine pipelines and cables are vital for transmitting physical and digital resources across bodies of water, necessitating regular inspection to assess maintenance needs. The safety of subsea pipelines and cables is paramount for sustaining industries such as telecommunications, power transmission, water supply, waste management, and oil and gas. Incidents like those involving the Nord Stream subsea pipeline and the SEA-ME-WE 4 subsea communications cable exemplify the severe economic and environmental consequences of damage to these critical infrastructures. Existing inspection methods often fail to meet accuracy requirements, emphasizing the need for advancements in inspection technologies. This comprehensive survey covers the sensors …

An Analysis And Ontology Of Teaching Methods In Cybersecurity Education, Sarah Buckley

LSU Master's Theses

The growing cybersecurity workforce gap underscores the urgent need to address deficiencies in cybersecurity education: the current education system is not producing competent cybersecurity professionals, and current efforts are not informing the non-technical general public of basic cybersecurity practices. We argue that this gap is compounded by a fundamental disconnect between cybersecurity education literature and established education theory. Our research addresses this issue by examining the alignment of cybersecurity education literature concerning educational methods and tools with education literature.

In our research, we endeavor to bridge this gap by critically analyzing the alignment of cybersecurity education literature with education theory. …

59th Student Senate Week 8 Meeting Minutes, Zoe Joubert

Student Senate Meeting Minutes

No abstract provided.

Reassignment Of A Junior Synonym Of Lepisosteus Oculatus Winchell 1864 To L. Platostomus Rafinesque 1820, Daniel Sinopoli, Thomas J. Near, Solomon R. David, Prosanta Chakrabarty

Faculty Publications

The foundation for the current taxonomy of Lepisosteidae (gars) was laid by Suttkus (1963) and Wiley (1976); these authors recognized only two extant genera as valid, Lepisosteus and Atractosteus. These authors also only recognized seven living species of gars and assigned several previously recognized species as junior synonyms. One of these, Lepisosteus oculatus Winchell 1864 possesses five junior synonyms: Cylindrosteus latirostris Girard 1858, Cylindrosteus productus Cope 1865, Cylindrosteus agassizii Duméril 1870, Cylindrosteus zadockii Duméril 1870 and Cylindrosteus bartonii Duméril 1870. Cylindrosteus zadockii was described from two syntypes collected from the “Upper Mississippi River” (MHNH 5799, 5800; Figure 1), and was …

Investigation Of Gas Dynamics In Water And Oil-Based Muds Using Das, Dts, And Dss Measurements, Temitayo S. Adeyemi

LSU Master's Theses

Reliable prediction of gas migration velocity, void fraction, and length of gas-affected region in water and oil-based muds is essential for effective planning, control, and optimization of drilling operations. However, there is a gap in our understanding of gas behavior and dynamics in water and oil-based muds. This is a consequence of the use of experimental systems that are not representative of field-scale conditions. This study seeks to bridge the gap via the well-scale deployment of distributed fiber-optic sensors for real-time monitoring of gas behavior and dynamics in water and oil-based mud. The aforementioned parameters were estimated in real-time using …

You’Re Looking Very Shane Today: Rhetorical Field Methods & The Materiality Of Queer Mediated Representation For Sapphic Women, Ariel L. Kizer

LSU Doctoral Dissertations

When marginalized communities are left without real-life mentors, they often turn to media as a guide. In this project I assert that mediated sapphic woman characters impact the identity development and everyday experiences for sapphic women in material ways. I explore what mediated narratives sapphic women consume and analyze how these messages become symbolic rhetorical tools that queer women rhetorically mobilize to narrativize and negotiate their queer identities. To achieve this goal, I utilized rhetorical field methods by interviewing 20 queer women ranging from the ages of 25-40 in dyadic, semi structured interviews. These women use varying terms to label …

Prescribed Fire Effects On Microbial Communities And Functions In Managed Ecosystems, Viet Dao

LSU Doctoral Dissertations

Microbes (both fungi and bacteria) serve important ecosystem functional roles in nutrient cycling and decomposition, which affect ecosystem response following disturbances such as prescribed fire. A multitude of abiotic and biotic factors influence microbial community compositions, which then drive microbial ecosystem functions. The factors driving microbial communities further change due to fire disturbances and progression with time. Although prescribed fire is commonly used as a technique for ecosystem management, the effects of fire on microbial communities or their functions are simply understudied. Ecosystem management decisions tend to focus on plant and ecosystem post-fire responses. Thus, incorporation of fire effects on …

Characterizing And Mitigating Transient Noise In Ligo Observatories For Gravitational Wave Detection, Jane Glanzer

LSU Doctoral Dissertations

The existence of gravitational waves is predicted by Albert Einstein's Theory of General Relativity. Commonly referred to as "ripples in spacetime", these waves are generated by some of the most violent and energetic processes in the universe. Despite their theoretical prediction over a century ago, it wasn't until 2015 that the Advanced LIGO (aLIGO) interferometers in Hanford, WA and Livingston, LA directly detected gravitational waves for the first time, confirming Einstein's theory and ushering in a new era of astrophysics.

Detecting gravitational waves requires incredible precision. Because of the extreme sensitivity required, it is possible for the gravitational wave data …

Problem-Solving In The Preparation Of Teachers For Agricultural Education: A Mixed Methods Study Investigating The Effect Of Metacognitive Awareness And Cognitive Ability On Students Enrolled In An Introductory Agricultural Mechanics Course, Whitney Figland

LSU Doctoral Dissertations

Cognitive and metacognitive ability have been identified as a critical factor that influences individuals to successfully problem-solve. However, recent research has indicated that students do not have the necessary 21st-century skills to be successful in the workplace. This issue has been confounded by the lack of school-based agricultural education (SBAE) teachers’ limited knowledge regarding effectively teaching decision-making skills and the use of teaching methods that promote problem-solving. Therefore, this study sought to understand the effect that cognitive and metacognitive ability had on the problem-solving of students who are enrolled in an Introduction to Agricultural Mechanics course at Louisiana State University. …

Aggressive Behaviors Related To Delirium In Hospitalized Older Adults: A Systematic Review, Julia D. Trahan

LSU Master's Theses

This is a systematic review of the aggressive behaviors related to delirium in hospitalized older adults. The objective of this study was to review relevant literature regarding the moderation of delirious related aggressive behaviors within a hospital setting and examining the extent of interventions being conducted with aggression being a main factor. The eligibility factors for studies to be included were as follows: diagnosis of delirium, aggressive behaviors or agitation present, study occurring within a hospital setting, the goal of preventing aggressive behaviors, and participants must be over the age of 65. Academic Search Complete, PsychINFO, MEDLINE, SocINDEX, CINHAL Complete …

The Impacts Of Nature-Based Sediment Restoration Practices On Coastal Wetland Soil Biogeochemistry, Jacob Z. Cheng

LSU Master's Theses

Coastal marshes provide many valuable ecosystem services. However, these wetlands are threatened worldwide, being subject to sea level rise, sediment starvation, subsidence, coastal edge erosion, etc. Many efforts are being made to counteract this wetland loss and preserve the ecosystem services. Two such methods are sediment diversion and the thin layer placement (TLP) of dredged sediment.

Sediment diversion involves reconnecting the main channel of a river body to disconnected wetlands, supplying much needed soil-building materials. However, this method affects the salinity of the waters, introducing large amounts of freshwater into the system. Salinity changes can affect marsh biogeochemistry. Most ecological …

Selective Vapor Condensation For The Synthesis And Assembly Of Spherical Colloids With A Precise Rough Patch, Kennedy A. Guillot, Philip J. Brahana, Ahmed Al Harraq, Nduka D. Ogbonna, Nicholas S. Lombardo, Jimmy Lawrence, Yaxin An, Michael G. Benton, Bhuvnesh Bharti

Faculty Publications

Patchy particles occupy an increasingly important space in soft matter research due to their ability to assemble into intricate phases and states. Being able to fine-tune the interactions among these particles is essential to understanding the principles governing the self-assembly processes. However, current fabrication techniques often yield patches that deviate chemically and physically from the native particles, impeding the identification of the driving forces behind self-assembly. To overcome this challenge, we propose a new approach to synthesizing spherical colloids with a well-defined rough patch on their surface. By treating polystyrene microspheres with vapors of a good solvent, here an acetone-water …

Language Beliefs And Practices Of Caregivers In The Deep South, Maria Maldonado

LSU Master's Theses

The 30 million word gap refers to the disparity in early language exposure between low socioeconomic status (SES) children and their higher SES peers; a gap that is thought to negatively impact children’s language development and future academic success. Although many early intervention approaches have proven effective in promoting language development among low SES children, they often fall short in terms of cultural responsiveness, which in turn affects caregiver buy-in. Culturally and linguistically diverse children disproportionately live in poverty, as such there is a need for research to inform more responsive interventions that take a strengths- based approach and build …

Quasistationary Distribution For The Invasion Model On A Complete Bipartite Graph, Clayton Allard, Iddo Ben-Ari, Shrikant Chand, Van Hovenga, Edith Lee, Julia Shapiro

Journal of Stochastic Analysis

No abstract provided.

The Homotopy Cardinality Of The Representation Category, Justin Murray

LSU Doctoral Dissertations

Given a Legendrian knot in (R^3, ker(dz − ydx)) one can assign a combinatorial invariants called ruling polynomials. These invariants have been shown to recover not only a (normalized) count of augmentations but are also closely related to a categorical count of augmentations in the form of the homotopy cardinality of the augmentation category. In this article, we prove that that the homotopy cardinality of the n-dimensional represen- tation category is a multiple of the n-colored ruling polynomial. Along the way, we establish that two n-dimensional representations are equivalent in the representation category if they are “conjugate homotopic”. We also …

59th Student Senate Week 7 Meeting Minutes, Zoe Joubert

Student Senate Meeting Minutes

No abstract provided.

Physical Activity Barriers And Facilitators In African American Women: A Social Ecological Models Perspective, Leah Ann Carter

LSU Doctoral Dissertations

African American (AA) women experience poor health outcomes that can be addressed by increasing PA engagement. Understanding how PA barriers and facilitators occur at multiple levels of influence may help tailor PA interventions for AA women. Although prior work has established barriers to PA that are unique to African American women, few studies identify the sociocultural norms associated with these impediments. Little is known about the cultural implications of barriers such as haircare maintenance, and public policy.

The primary aim of this dissertation was to capture AA women’s voice about PA barriers and facilitators using the social ecological model framework. …

What Is Eai? A Short History Of The Style’S Evolution And Development Of Identifiable Characteristics, Dylan Burchett

LSU Doctoral Dissertations

EAI (Electro-Acoustic Improvisation) has long presented issues pertaining to its definition and practice. This is due to the wide range of acoustic and electronic sounds present in the style as well as the style’s stated adherence to improvisation. This stated adherence to improvisation and wide potential range of acoustic and electronic sounds seem to clash with EAI’s stylistic consistencies. Because the EAI style has been difficult to define, it has also been difficult to place historically within experimental music traditions. In order to clarify the definition, practice, and historical positioning of EAI and identify where the style’s boundary lines around …