Digital Commons Network^™

Low Temperature Methane Coupling With Co And Co2, A K M Kazi F.M. Aurnob

LSU Doctoral Dissertations

Methane is the smallest hydrocarbon and the most abundant component in natural gas. Despite its availability, its chemical utilization has remained limited due to the challenges associated with direct methane activation and conversion. Most of the methane oxidation and oxidative carbonylation reactions in literature have been carried out at high-pressure using batch reactors or at ambient pressure using flow reactors. While batch reactors have been shown to have higher product yields, they are limited in their capability to provide real-time kinetic insights and comprehensive mechanistic understanding of the reactions involved due to the long residence time. This limits rationalization of …

Precision Spectral Measurements Of Chromium And Titanium From 10 To 250  Gev/N And Sub-Iron To Iron Ratio With The Calorimetric Electron Telescope On The International Space Station, O. Adriani, Y. Akaike, K. Asano, Y. Asaoka, E. Berti, P. Betti, G. Bigongiari, W. R. Binns, M. Bongi, P. Brogi, A. Bruno, N. Cannady, G. Castellini, C. Checchia, M. L. Cherry, G. Collazuol, G. A. De Nolfo, K. Ebisawa, A. W. Ficklin, H. Fuke, S. Gonzi, T. G. Guzik, T. Hams, K. Hibino, M. Ichimura, M. H. Israel, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, C. Kato, N. Kawanaka, Y. Kawakubo

Faculty Publications

The Calorimetric Electron Telescope (CALET), in operation on the International Space Station since 2015, collected a large sample of cosmic-ray (CR) iron and sub-iron events over a wide energy interval. In this Letter, we report an update of our previous measurement of the iron flux and we present-for the first time-a high statistics measurement of the spectra of two sub-iron elements Cr and Ti in the energy interval from 10 to 250  GeV/n. The analyses are based on 8 years of data. Differently from older generations of cosmic-ray instruments which, in most cases, could not resolve individual sub-iron elements, CALET …

Ergonomic And Biomechanical Assessment Of Vertical Ladder Climbing For Exoskeleton Integration In Construction Tasks, Ehsan Shourangiz

LSU Master's Theses

Active exoskeletons are increasingly utilized in physically demanding industries such as construction and manufacturing to reduce strain and lower the risk of work-related musculoskeletal disorders, supporting worker safety and long-term health. However, most existing systems are designed for repetitive tasks like lifting or prolonged standing, with limited consideration for dynamic activities such as vertical ladder climbing. Ladder climbing is common and physically demanding in industrial environments, often required to access elevated areas like scaffolding, tanks, or rooftops. Since exoskeletons are intended to remain worn throughout multiple tasks, requiring workers to remove and re-don the device during ladder climbing would reduce …

Participation Of Battery Energy Storage Systems In Load Frequency Control Of Power Systems, Zakaria Afsharbakeshloo

LSU Doctoral Dissertations

In this research, functionalities and roles of Battery Energy Storage Systems (BESSs) in power systems are extended beyond primary frequency control (PFC). The BESSs, while participating in PFC, are controlled through charge controllers to first maintain their state-of-charge (SOC) within an acceptable range through a primary charge controller, and to recharge the BESS to its maximum SOC through a secondary charge controller. This forms a hierarchical frequency and SOC control of power grids with BESSs. In this regard, multiple BESS case is considered as well, and by employing the SOC balancing principle, it is shown that desired power sharing among …

Hemp Cultivation Under Off-Season High Tunnel Growth Chamber Environments In South Louisiana, Gabriel Lococo

LSU Master's Theses

Industrial hemp (Cannabis sativa) production in Louisiana began in 2020 with 932 acres cultivated for fiber and cannabidiol (CBD) extraction. By 2024, production had declined to just 58.4 acres (Louisiana Department of Agriculture and Forestry, personal communication). During the 2020–2021 season, over 40% of field-grown hemp was lost due to tropical storms, insect pressure, and diseases associated with warm, wet conditions. To mitigate these challenges, hemp was planted and harvested between November and January, a cooler period with reduced environmental stress.

‘Sour Citron’, a day-neutral cultivar, was selected for its insensitivity to photoperiod, enabling flowering during shorter days. …

A Transcendental Phenomenology: Exploring The College Choice Process Of Black Undergraduate Students Who Transfer From Predominantly White Institutions To Historically Black Colleges And Universities, Heather Oliver Freeman

LSU Doctoral Dissertations

Researchers have studied college students and the college choice process extensively in the higher education realm of academia. Often, college choice is explored from a lens of the traditional high school student approaching the initial college choice decision. Furthermore, higher education is an expansive topic that not only includes public and private institutions, two- and four-year institutions, but also predominantly White institutions (PWIs) and historically Black colleges and universities (HBCUs). The purpose of this transcendental phenomenological study was to explore the college choice process and transfer experiences of undergraduate Black students who transfer from a PWI to an HBCU. This …

Magnetic Field Enabled Assembly And Propulsion Of Colloidal Particles In A Magnetic Medium, Hashir M. Gauri

LSU Doctoral Dissertations

Colloidal particles are nano/micro meter-sized particles dispersed in a fluid medium and serve as diverse building blocks for assembling complex structures. The ease of tunability of the shape, size, and interparticle interactions of colloidal particles facilitates their assembly into rich structures and phases that mirror the assembly process of atomic systems. Often regarded as "big atoms" colloidal particles provide an ideal model system for investigating complex phenomena in condensed matter, such as crystallization and nucleation. While the assembly of colloids under thermodynamic equilibrium has been extensively studied, recent interest has shifted toward exploring colloids in non-equilibrium conditions to create dynamic …

Anion Exchange Membrane Durability For Electrochemical Co2 Reduction In Membrane Electrode Assembly Cells, Soundarzo Tasnim

LSU Master's Theses

The electrochemical reduction of CO₂ using membrane electrode assembly (MEA) cells has emerged as a promising approach for carbon capture and conversion into valuable products. This study investigates the degradation mechanisms of anion exchange membranes (AEMs) in CO₂ reduction applications, focusing on Sustainion X37-50, PiperION, and FAA-3-50. The research analyzes the impact of chemical and mechanical degradation on membrane performance, highlighting key stability challenges in long-term operation. Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS) were employed to monitor functional group stability and ionic conductivity loss over extended operation. The results indicate that hydroxide-induced degradation leads to nucleophilic …

Energy Equity In The Built Environment: Analyzing Building Energy Consumption For American Low-Income Households, Sorena Vosoughkhosravi

LSU Doctoral Dissertations

The built environment consumes a significant amount of energy in the United States, with outdated and inefficient affordable housing increasing financial pressure on low-income households (LIHs) who face high energy burdens. This research aims to assess the energy performance of American households, focusing on LIHs, to promote energy justice by providing data-driven insights and models for energy efficiency improvements. More specifically, this research aims to (1) create a large-scale national residential building energy dataset by integrating the American Housing Survey and the Residential Energy Consumption Survey using machine learning techniques; (2) analyze and model American household occupancy profiles by leveraging …

Investigating Hurricane-Induced Salt Variation Across The Land-Estuary-Ocean Continuum Using A Dynamically Coupled Hydrological-Ocean Model, Xiaochen Zhao, Z. George Xue, Daoyang Bao, John Warner, Yanda Ou

Faculty Publications

Salinity variations across the Land-Estuary-Ocean (LEO) continuum are critical for coastal ecosystems and impact the socioeconomic benefits to local communities. However, evaluating these variations is challenging due to the complex interactions of terrestrial and oceanic processes, including river discharge, winds, tides, sea level rise, and storms. This study incorporates a salinity module into a newly developed dynamically coupled hydrological-ocean model on the COAWST platform, which is, to the best of our knowledge, the first process-based modeling that achieves seamless two-way land-ocean water and salt exchanges across the LEO continuum, facilitating simulations of landward salt input and transport. Using Hurricane Florence …

Water Exposure Time Distributions Controlled By Freshwater Releases In A Semi-Enclosed Estuary, Caitlin R.R. Turner, Matthew Hiatt

Faculty Publications

Freshwater diversions manage water shortages, salinity, and control floodwater by redirecting river flows; however, their full ecological and hydrological impact remains unknown. This study examines the Lake Pontchartrain Estuary in Louisiana using a hydrodynamic model and Lagrangian particle tracking to assess how diversion operations (open, closed) and tributary discharge levels (low, median, high) influence water exposure time—the cumulative duration water remains in a domain, including re-entry. Exposure time was analyzed based on the time required for 50%, 75%, and 90% of released particles ((Formula presented.), (Formula presented.), and (Formula presented.)) to leave a defined region of interest (ROI). Results show …

Prompt Periodicity In The Grb 211211a Precursor: Black-Hole Or Magnetar Engine?, Gavin P. Lamb, Thomas Baxter, Conor M.B. Omand, Dimple, Zoë Mcgrath, Cairns Turnbull, Eric Burns, Hamid Hamidani, Ilya Mandel, Kim L. Page, Stephan Rosswog, Nikhil Sarin, Andrew Blain, Laurence Datrier, Shiho Kobayashi, Andrew Levan, Rhaana Starling, Benjamin Gompertz, Nusrin Habeeb, Khang Nguyen, Nial Tanvir

Faculty Publications

The merger origin long GRB 211211A was a class (re-)defining event. A precursor was identified with a s separation from the main burst, as well as a claimed candidate quasi-periodic oscillation (QPO) with a frequency Hz. Here, we explore the implications of the precursor, assuming the quasi-periodicity is real. The precursor variability time-scale requires relativistic motion with a Lorentz factor, and implies an engine-driven jetted outflow. The declining amplitude of the consecutive pulses requires an episodic engine with an 'on/off' cycle consistent with the QPO. For a black-hole central engine, the QPO can have its origin in Lense-Thirring precession of …

Explaining Nonmerger Gamma-Ray Bursts And Broad-Lined Supernovae With Close Binary Progenitors With Black Hole Central Engines, Christopher L. Fryer, Eric Burns, Anna Y.Q. Ho, Alessandra Corsi, Amy Y. Lien, Daniel A. Perley, Jada L. Vail, V. Ashley Villar

Faculty Publications

For over 25 yr, the origin of long-duration gamma-ray bursts (lGRBs) has been linked to the collapse of rotating massive stars. However, we have yet to pinpoint the stellar progenitor powering these transients. Moreover, the dominant engine powering the explosions remains open to debate. Observations of both lGRBs, supernovae associated with these GRBs, such as broad-line (BL) stripped-envelope (type Ic) supernovae (hereafter, Ic-BL), supernovae (SNe), and perhaps superluminous SNe, fast blue optical transients, and fast x-ray transients, may provide clues to both engines and progenitors. In this paper, we conduct a detailed study of the tight-binary formation scenario for lGRBs, …

On Excursions Associated With A Certain Local Time Of Simple Symmetric Random Walks, With Applications, Takahiko Fujita, Naohiro Yoshida

Journal of Stochastic Analysis

In this note, some applications of excursions associated with a certain local time of simple symmetric random walks are presented. Specifically, the excursions are applied to calculate some probability distributions of interest regarding the random walks. Furthermore, a solution of the Skorokhod embedding problem for random walks is obtained through the excursions.

Intersectionality And Experiences With Mental Health Care: Transgender And Gender Diverse Autistic Adults, Megan Callahan

LSU Doctoral Dissertations

Current prevalence rates of autism spectrum disorder (ASD) in transgender and gender diverse (TGD) populations range between 4 and 13% (Thrower et al., 2020). Studies into autistic TGD individuals’ experiences with healthcare have primarily collected qualitative data, identifying themes including barriers to healthcare, invalidation of both autistic and TGD identities, difficulty finding competent providers, limited support and resources, and refusal of care (Cooper et al., 2022; Maroney & Horne, 2022; Hall et al., 2020). N = 3094 self-identified TGD adults completed the 2017 TransLifeline Mental Health Survey, a collaborative effort between the National LGBTQ Task Force and the TransLifeline, which …

Gamma Irradiation Effects On Physical And Electronic Properties Of Monolayer Cvd Grown Graphene, Chintan P. Chavda, Ashok Srivastava, Erin Vaughan, Jianwei Wang, Manas Ranjan Gartia, Georgios Veronis

Faculty Publications

Two-dimensional material graphene has proven to have remarkable electrical and photonic properties, opening the door to a wide range of uses, including employment under the harsh conditions of space. The creation of graphene on various substrate types is known to be possible via a number of approaches, including direct deposition and the substrate transfer process. In this work, we used an argon plasma, methane as a carbon source, and a nanoCVD-8G graphene reactor to deposit monolayer graphene (MLG) on transition metal substrates for studying the effects of gamma irradiation on the physical and electronic properties. Graphene's crystalline structure is investigated …

Development And Demonstration Of The Operational Sustainability Index (Opsi): A Multidimensional Metric For Building Performance Evaluation, Oluwafemi Awolesi, Margaret Reams

Faculty Publications

In promoting sustainable cities and societies, accelerating the shift from sustainable building design to sustainable building operations is essential. A persistent challenge lies in the absence of a unified, multidimensional metric that enables meaningful performance comparisons across buildings of similar types and functions, both regionally and globally. This study develops and demonstrates the operational sustainability index (OPSi)—a novel metric grounded in case study research that integrates indoor environmental quality (IEQ) and energy utility quality (EUQ). OPSi is applied to six buildings in three comparative cases: (1) LEED-certified and non-certified dormitories, (2) LEED-certified and non-certified event buildings, and (3) male- and …

Maximum-Likelihood Estimation Of Glandular Fraction For Mammography And Its Effect On Microcalcification Detection, Bryce J. Smith, Joyoni Dey, Lacey Medlock, David Solis, Krystal Kirby

Faculty Publications

Breast tissue is mainly a mixture of adipose and fibro-glandular tissue. Cancer risk and risk of undetected breast cancer increases with the amount of glandular tissue in the breast. Therefore, radiologists must report the total volume glandular fraction or a BI-RADS classification in screening and diagnostic mammography. In this work, a Maximum Likelihood algorithm accounting for count statistics and scatter is shown to estimate the pixel-wise glandular fraction from mammographic images. The pixel-wise glandular fraction provides information that helps localize dense tissue. The total volume glandular fraction can be calculated from pixel-wise glandular fraction. The algorithm was implemented for images …

High-Significance Detection Of Correlation Between The Unresolved Gamma-Ray Background And The Large-Scale Cosmic Structure, B. Thakore, M. Negro, M. Regis, S. Camera, D. Gruen, N. Fornengo, A. Roodman, A. Porredon, T. Schutt, A. Cuoco, A. Alarcon, A. Amon, K. Bechtol, M. Becker, G. Bernstein, A. Campos, A. Carnero Rosell, M. Carrasco Kind, R. Cawthon, C. Chang, R. Chen, A. Choi, J. Cordero, C. Davis, J. Derose, H. Diehl, S. Dodelson, C. Doux, A. Drlica-Wagner, K. Eckert, J. Elvin-Poole, S. Everett, A. Ferté

Faculty Publications

Our understanding of the γ-ray sky has improved dramatically in the past decade, however, the unresolved γ-ray background (UGRB) still has a potential wealth of information about the faintest γ-ray sources pervading the Universe. Statistical cross-correlations with tracers of cosmic structure can indirectly identify the populations that most characterize the γ-ray background. In this study, we analyze the angular correlation between the γ-ray background and the matter distribution in the Universe as traced by gravitational lensing, leveraging more than a decade of observations from the Fermi-Large Area Telescope (LAT) and 3 years of data from the Dark Energy Survey (DES). …

X-Ray Polarization Of The Magnetar 1e 1841−045, Rachael Stewart, George A. Younes, Alice K. Harding, Zorawar Wadiasingh, Matthew G. Baring, Michela Negro, Tod E. Strohmayer, Wynn C.G. Ho, Mason Ng, Zaven Arzoumanian, Hoa Dinh Thi, Niccolò Di Lalla, Teruaki Enoto, Keith Gendreau, Chin Ping Hu, Alex Van Kooten, Chryssa Kouveliotou, Alexander Mcewen

Faculty Publications

We report on IXPE and NuSTAR observations beginning 40 days after the 2024 outburst onset of magnetar 1E 1841−045, marking the first IXPE observation of a magnetar in an enhanced state. Our spectropolarimetric analysis indicates that both a blackbody (BB) plus double power-law (PL) and a double blackbody plus power-law spectral model fit the phase-averaged intensity data well, with a hard PL tail (Γ = 1.19 and 1.35, respectively) dominating above ≈5 keV. For the former model, we find the soft PL (the dominant component at soft energies) exhibits a polarization degree (PD) of ≈30% while the hard PL displays …

Evaluation Of The Effects Of Various Types Of Inert And Active Fillers On Asphalt Mixture Performance, Mohammad Hadizadeh Pirbasti

LSU Master's Theses

Abstract:

The performance of asphalt mixtures is significantly influenced by the type and characteristics of fillers used as a replacement for filler part of the aggregates’ batching. According to this research investigation the performance along with durability characteristics of asphalt mixtures are evaluated through different inert and active fillers. The fillers used include Fly Ash, Cement, steel slag powder, and additional filler. These fillers incorporate into two types of asphalt mix design of Stone Matrix Asphalt (SMA) and a surface mix. Fillers are categorized according to their reactive properties alongside their physical attributes leading to active fillers strengthening bond formation …

Kevin Bobo's Boboland: A Performer's Guide, Tyler D. Whitehead

LSU Doctoral Dissertations

Kevin Bobo is an active American percussionist, educator, and performer that continues to leave a lasting influence in the percussion community. His works for chamber percussion ensemble and solo marimba continue to push the limitations for percussionists in terms of technical ability, new compositional methods and techniques for expanded timbral effects. Bobo’s compositions such as Boboland, a marimba solo with percussion quartet, present technical and musical challenges that are generally unaligned with traditional performance practices in percussion and especially the marimba. This document aims to provide detailed guidance and instruction for the performance of Boboland and will cover all aspects …

Enhancing Photosynthesis Under Salt Stress Via Directed Evolution In Cyanobacteria, Zhenxiong Jiang, Khondokar Nowshin Islam, Malory Wolfe, Michael O'Connell, Dykia Williams, Ashley Florance, David J. Vinyard, Xiaohui Zhang, Maxwell Brenner, Andor J. Kiss, Xianhua Liu, Xin Wang

Faculty Publications

A key aspect of enhancing photosynthesis is improving the kinetics of photochemical quenching recovery following environmental perturbation or stress. Salt stress exacerbates high light stress in cyanobacteria and leads to severe yield losses in crop plants. Genetic traits that confer salt tolerance without compromising photosynthetic performance are essential for improving photosynthesis under these conditions. Here, we applied accelerated evolution in Synechococcus elongatus PCC 7942 by conditionally suppressing its methyl-directed mismatch repair system to obtain beneficial genetic traits for enhanced photosynthesis under salt stress. We screened over 10,000 mutants and isolated 8 strains with increased biomass or sucrose productivity under salt …

Interfacial Phenomena Of Plastics: From Surface Modifications To Environmental Impacts, Kennedy Guillot

LSU Doctoral Dissertations

Plastic is a ubiquitous part of everyday life since its introduction in the previous century. Global production continues to exponentially increase, establishing plastics as one of the most dominant materials in modern manufacturing. Within the scope of academia, plastic is essential due to its low cost and sterility, particularly for minimizing contamination. Beyond the laboratory, plastic use spans numerous industries, and its use and disposal has since raised many environmental concerns. Once valued for its durability, plastics now pollute the environment in landfills and natural ecosystems. In recent decades, the consequences of this pollution have been investigated, yet the full …

Enduring Words: Resistance Through Sculptural Libraries, Alex C. Jacobs

LSU Master's Theses

Enduring Words: Resistance Through Sculptural Libraries is a thesis exhibition that challenges book censorship by transforming reading into a public and defiant act. Through direct sculptural interventions, the exhibition confronts cultural erasure, questions who controls the literature we consume, and highlights the role of art in safeguarding contested knowledge. This thesis focuses on a current body of exhibited sculptural works that embody the tension between access and erasure. These installations engage with the viewer by using a lighthouse built of books and a speech-bubble-shaped library embedded with censored texts. They do not quietly mourn the suppression of knowledge; they confront …

Passive Vibration Isolation Systems For Mitigating Rotational Forces In Football Helmet Impacts, Julian Lee

LSU Master's Theses

Helmets have been used for centuries to mitigate head injuries, evolving with advancements in materials and design. They are critical in athletics, construction, and military applications, where shock and vibration isolation play a key role in head protection. Helmet performance is currently rated using the Head Injury Criterion (HIC) and Helmet Performance Score (HPS) metrics. HIC is a metric used in sports and automotive industries which focuses on the probability of injury occurring due to the magnitude and duration of linear acceleration of the head [1]. The HPS metric was created by using a linear combination of HIC and a …

All But Mud & Memories, Chase Lt Romero

LSU Master's Theses

All But Mud & Memories addresses the inevitability of erosion and land loss near my homeland of Algiers Point— locally known as The Point— through the perspective of locals and visitors, in addition to my own experience. Located near New Orleans across the Mississippi River, Algiers Point holds a community that shares a tender bond with the levee that protects their home and day-to-day interactions. Often in discussions of wetland events in Louisiana, the focus is on land and environmental losses rather than the surrounding culture. I provide a more community-centered narrative by expressing what’s to be lost if the …

The Nature Of Optical Afterglows Without Gamma-Ray Bursts: Identification Of At2023lcr And Multiwavelength Modeling, Maggie L. Li, Anna Y.Q. Ho, Geoffrey Ryan, Daniel A. Perley, Gavin P. Lamb, A. J. Nayana, Igor Andreoni, G. C. Anupama, Eric C. Bellm, Edo Berger, Joshua S. Bloom, Eric Burns, Ilaria Caiazzo, Poonam Chandra, Michael W. Coughlin, Kareem El-Badry, Matthew J. Graham, Mansi Kasliwal, Garrett K. Keating, S. R. Kulkarni, Harsh Kumar, Frank J. Masci, Richard A. Perley, Josiah Purdum, Ramprasad Rao, Antonio C. Rodriguez, Ben Rusholme, Nikhil Sarin, Jesper Sollerman, Gokul P. Srinivasaragavan, Vishwajeet Swain, Zachary Vanderbosch

Faculty Publications

In the past few years, the improved sensitivity and cadence of wide-field optical surveys have enabled the discovery of several afterglows without associated detected gamma-ray bursts (GRBs). We present the identification, observations, and multiwavelength modeling of a recent such afterglow (AT 2023lcr), and model three literature events (AT 2020blt, AT 2021any, and AT 2021lfa) in a consistent fashion. For each event, we consider the following possibilities as to why a GRB was not observed: (1) the jet was off-axis; (2) the jet had a low initial Lorentz factor; and (3) the afterglow was the result of an on-axis classical GRB …

Airfield Pavement Management Framework Using Advanced Modeling Techniques, Heena Dhasmana, Marwa Hassan, Elise Mansour

Publications

Airport authorities constantly collect pavement condition data and utilize life-cycle cost analysis to select construction and maintenance alternatives. The current Federal Aviation Administration (FAA) Advisory Circular 150/5380-7B recommends using Pavement Condition Index (PCI) to assess airfield pavement condition for planning of Maintenance and Rehabilitation (M&R) treatments. However, structural and functional performance might not be fairly represented by solely one indicator, the PCI. The latter might mask the root cause of the pavement deterioration and lead to inadequate M&R recommendations. Furthermore, the regression nature of the existing airfield pavement assessment models is not adequate for establishing pavement performance prediction as a …

Optimizing The Sustainability Of Asphalt Pavements Through Incorporating Crumb Rubber In High-Modulus Asphalt Concrete (Hmac) Mixtures In Louisiana, Heena Dhasmana, Marwa Hassan, Mohamed Abdelmageed

Publications

Asphalt mixtures are traditionally produced using the Superpave mix design method, which emphasizes volumetric properties; however, current research is shifting toward performance-based and sustainable approaches. Within this context, the French High Modulus Asphalt Concrete (HMAC) design focuses on achieving specific performance criteria for workability, stiffness, rutting resistance, and fatigue behavior, employing a hard binder with higher asphalt content and fewer air voids than Superpave mixes. In this study, HMAC mixtures were developed using crumb rubber and locally sourced Louisiana materials. Five HMAC mixes using PG 76-22 and PG 67-22 binders with 10% and 20% crumb rubber were prepared, along with …