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New Frontiers In The Measurement Of Energy Metabolism, Alexandra Niclou, Philippe St-Martin, Leanne M. Redman, Audrey Bergouignan Sep 2023

New Frontiers In The Measurement Of Energy Metabolism, Alexandra Niclou, Philippe St-Martin, Leanne M. Redman, Audrey Bergouignan

Clinical Research Faculty Publications

This perspective highlights three key areas of current and future energy metabolism research: intergenerational health, climate change, and interplanetary exploration. We describe the recent advances in determining estimated energy requirements for a large subset of the general population using the gold standard method for free-living total daily energy expenditure estimates, the doubly labeled water method. The global rise in overweight and obesity demands particular attention to energy requirements in pregnancy and early life, as accumulating evidence contributes to our understanding of intergenerational health transmission and the potential for epigenetic programming in utero. We also acknowledge some gaps in necessary guidelines …

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A Smartphone-Enabled Imaging Device For Chromotropic Acid-Based Measurement Of Nitrate In Soil Samples, Veerabhadrappa Lavanya, Anshuman Nayak, Partha Deb Roy, Shubhadip Dasgupta, Subhadip Dey, Bin Li, David C. Weindorf, Somsubhra Chakraborty Sep 2023

A Smartphone-Enabled Imaging Device For Chromotropic Acid-Based Measurement Of Nitrate In Soil Samples, Veerabhadrappa Lavanya, Anshuman Nayak, Partha Deb Roy, Shubhadip Dasgupta, Subhadip Dey, Bin Li, David C. Weindorf, Somsubhra Chakraborty

Faculty Publications

In this study, a novel chromotropic acid-based color development method was proposed for quick estimation of soil nitrate (NO3−). The method utilized a 3D printed device integrated with the rear-end camera of a smartphone and a stand-alone application called SMART NP. By analyzing the mean Value (V) component of the sample’s image, the SMART NP provides instant predictions of soil NO3− levels. The limit of detection was calculated as 0.1 mg L−1 with a sensitivity of 0.26 mg L−1. The device showed a % bias of 0.9% and a precision of 1.95%, indicating its reliability. Additionally, the device-predicted soil NO3− …

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The Problem With Repurposing Genetically Modified Organisms, Robert Kesterson, Elizabeth Floyd Sep 2023

The Problem With Repurposing Genetically Modified Organisms, Robert Kesterson, Elizabeth Floyd

Division of Basic Science Faculty Publications

No abstract provided.

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The Type 1 Diabetes And Exercise Initiative: Predicting Hypoglycemia Risk During Exercise For Participants With Type 1 Diabetes Using Repeated Measures Random Forest, Simon Bergford, Michael C. Riddell, Peter G. Jacobs, Zoey Li, Robin L. Gal, Mark A. Clements, Francis J. Doyle, Corby K. Martin, Susana R. Patton, Jessica R. Castle, Melanie B. Gillingham, Roy W. Beck, Michael R. Rickels, Peter Calhoun Sep 2023

The Type 1 Diabetes And Exercise Initiative: Predicting Hypoglycemia Risk During Exercise For Participants With Type 1 Diabetes Using Repeated Measures Random Forest, Simon Bergford, Michael C. Riddell, Peter G. Jacobs, Zoey Li, Robin L. Gal, Mark A. Clements, Francis J. Doyle, Corby K. Martin, Susana R. Patton, Jessica R. Castle, Melanie B. Gillingham, Roy W. Beck, Michael R. Rickels, Peter Calhoun

Clinical Research Faculty Publications

Objective: Exercise is known to increase the risk for hypoglycemia in type 1 diabetes (T1D) but predicting when it may occur remains a major challenge. The objective of this study was to develop a hypoglycemia prediction model based on a large real-world study of exercise in T1D. Research Design and Methods: Structured study-specified exercise (aerobic, interval, and resistance training videos) and free-living exercise sessions from the T1D Exercise Initiative study were used to build a model for predicting hypoglycemia, a continuous glucose monitoring value < 70 mg/dL, during exercise. Repeated measures random forest (RMRF) and repeated measures logistic regression (RMLR) models were constructed to predict hypoglycemia using predictors at the start of exercise and baseline characteristics. Models were evaluated with area under the receiver operating characteristic curve (AUC) and balanced accuracy. Results: RMRF and RMLR had similar AUC (0.833 vs. 0.825, respectively) and both models had a balanced accuracy of 77%. The probability of hypoglycemia was higher for exercise sessions with lower pre-exercise glucose levels, negative pre-exercise glucose rates of change, greater percent time < 70 mg/dL in the 24 h before exercise, and greater pre-exercise bolus insulin-on-board (IOB). Free-living aerobic exercises, walking/hiking, and physical labor had the highest probability of hypoglycemia, while structured exercises had the lowest probability of hypoglycemia. Conclusions: RMRF and RMLR accurately predict hypoglycemia during exercise and identify factors that increase the risk of hypoglycemia. Lower glucose, decreasing levels of glucose before exercise, and greater pre-exercise IOB largely predict hypoglycemia risk in adults with T1D.

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Is Macroporosity Controlled By Complexed Clay And Soil Organic Carbon?, Aaron N. Koop, Daniel R. Hirmas, Sharon A. Billings, Li Li, Alejandro Cueva, Xi Zhang, Hang Wen, Attila Nemes, Lígia F.T. Souza, Hoori Ajami, Alejandro N. Flores, Aoesta K. Rudick, Annalise Guthrie, Lola M. Klamm, Micah Unruh, Pamela L. Sullivan Sep 2023

Is Macroporosity Controlled By Complexed Clay And Soil Organic Carbon?, Aaron N. Koop, Daniel R. Hirmas, Sharon A. Billings, Li Li, Alejandro Cueva, Xi Zhang, Hang Wen, Attila Nemes, Lígia F.T. Souza, Hoori Ajami, Alejandro N. Flores, Aoesta K. Rudick, Annalise Guthrie, Lola M. Klamm, Micah Unruh, Pamela L. Sullivan

Faculty Publications

Multi-scale evidence of rapid, climate-induced soil structural changes occurring at yearly to decadal timescales is mounting. As a result, it has become increasingly important to identify the properties and mechanisms controlling the development and maintenance of soil structure and associated macroporosity. This is especially relevant since macroporosity has disproportionate effects on saturated hydraulic conductivity (Ksat) which strongly influences water storage and flux, thus, affecting the water cycle. In this study, we use decision trees and piecewise linear regression to assess the influence of soil and climate properties on effective porosity (EP; a proxy of macroporosity) in both surface and subsurface …

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Upper Ocean Biogeochemistry Of The Oligotrophic North Pacific Subtropical Gyre: From Nutrient Sources To Carbon Export, Minhan Dai, Ya Wei Luo, Eric P. Achterberg, Thomas J. Browning, Yihua Cai, Zhimian Cao, Fei Chai, Bingzhang Chen, Matthew J. Church, Dongjian Ci, Chuanjun Du, Kunshan Gao, Xianghui Guo, Zhendong Hu, Shuh Ji Kao, Edward A. Laws, Zhongping Lee, Hongyang Lin, Qian Liu, Xin Liu, Weicheng Luo, Feifei Meng, Shaoling Shang, Dalin Shi, Hiroaki Saito, Luping Song, Xianhui Sean Wan, Yuntao Wang, Wei Lei Wang, Zuozhu Wen, Peng Xiu, Jing Zhang, Ruifeng Zhang Sep 2023

Upper Ocean Biogeochemistry Of The Oligotrophic North Pacific Subtropical Gyre: From Nutrient Sources To Carbon Export, Minhan Dai, Ya Wei Luo, Eric P. Achterberg, Thomas J. Browning, Yihua Cai, Zhimian Cao, Fei Chai, Bingzhang Chen, Matthew J. Church, Dongjian Ci, Chuanjun Du, Kunshan Gao, Xianghui Guo, Zhendong Hu, Shuh Ji Kao, Edward A. Laws, Zhongping Lee, Hongyang Lin, Qian Liu, Xin Liu, Weicheng Luo, Feifei Meng, Shaoling Shang, Dalin Shi, Hiroaki Saito, Luping Song, Xianhui Sean Wan, Yuntao Wang, Wei Lei Wang, Zuozhu Wen, Peng Xiu, Jing Zhang, Ruifeng Zhang

Faculty Publications

Subtropical gyres cover 26%–29% of the world's surface ocean and are conventionally regarded as ocean deserts due to their permanent stratification, depleted surface nutrients, and low biological productivity. Despite tremendous advances over the past three decades, particularly through the Hawaii Ocean Time-series and the Bermuda Atlantic Time-series Study, which have revolutionized our understanding of the biogeochemistry in oligotrophic marine ecosystems, the gyres remain understudied. We review current understanding of upper ocean biogeochemistry in the North Pacific Subtropical Gyre, considering other subtropical gyres for comparison. We focus our synthesis on spatial variability, which shows larger than expected dynamic ranges of properties …

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Leveraging Cultural Wealth, Identities And Motivation: How Diverse Intersectional Groups Of Low-Income Undergraduate Stem Students Persist In Collegiate Stem Environments, Raeshan D. Davis, Zakiya Wilson-Kennedy Sep 2023

Leveraging Cultural Wealth, Identities And Motivation: How Diverse Intersectional Groups Of Low-Income Undergraduate Stem Students Persist In Collegiate Stem Environments, Raeshan D. Davis, Zakiya Wilson-Kennedy

Faculty Publications

Grounded in a conceptual framework incorporating intersectionality, motivation, self-determination, and self-efficacy, this empirical study investigated how individuals’ identities, mindsets, and resources in educational environments intentionally cultivated to support their decision-making, development, and connections in the science community, can significantly increase the recruitment, persistence, and success of low-income, academically talented science students from diverse backgrounds. Several factors—academic performance in coursework, self-image, self-agency, financial support, and social integration in the science culture—continue to significantly impact student retention and persistence in STEM disciplines. Many of these factors are negatively affected based on a students’ intersecting identities, which can be detrimental to their academic …

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Extreme Variability In A Long-Duration Gamma-Ray Burst Associated With A Kilonova, P. Veres, P. N. Bhat, E. Burns, R. Hamburg, N. Fraija, D. Kocevski, R. Preece, S. Poolakkil, N. Christensen, M. A. Bizouard, T. Dal Canton, S. Bala, E. Bissaldi, M. S. Briggs, W. Cleveland, A. Goldstein, B. A. Hristov, C. M. Hui, S. Lesage, B. Mailyan, O. J. Roberts, C. A. Wilson-Hodge Sep 2023

Extreme Variability In A Long-Duration Gamma-Ray Burst Associated With A Kilonova, P. Veres, P. N. Bhat, E. Burns, R. Hamburg, N. Fraija, D. Kocevski, R. Preece, S. Poolakkil, N. Christensen, M. A. Bizouard, T. Dal Canton, S. Bala, E. Bissaldi, M. S. Briggs, W. Cleveland, A. Goldstein, B. A. Hristov, C. M. Hui, S. Lesage, B. Mailyan, O. J. Roberts, C. A. Wilson-Hodge

Faculty Publications

The recent discovery of a kilonova from the long-duration gamma-ray burst (GRB) GRB 211211A challenges classification schemes based on temporal information alone. Gamma-ray properties of GRB 211211A reveal an extreme event, which stands out among both short and long GRBs. We find very short variations (few milliseconds) in the lightcurve of GRB 211211A and estimate ∼1000 for the Lorentz factor of the outflow. We discuss the relevance of the short variations in identifying similar long GRBs resulting from compact mergers. Our findings indicate that in future gravitational-wave follow-up campaigns, some long-duration GRBs should be treated as possible strong gravitational-wave counterparts.

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Probiotic Characteristics Of Streptococcus Thermophilus And Lactobacillus Bulgaricus As Influenced By New Food Sources, Ashly Castro, Ricardo S. Aleman, Miguel Tabora, Shirin Kazemzadeh, Leyla K. Pournaki, Roberto Cedillos, Jhunior Marcia, Kayanush Aryana Sep 2023

Probiotic Characteristics Of Streptococcus Thermophilus And Lactobacillus Bulgaricus As Influenced By New Food Sources, Ashly Castro, Ricardo S. Aleman, Miguel Tabora, Shirin Kazemzadeh, Leyla K. Pournaki, Roberto Cedillos, Jhunior Marcia, Kayanush Aryana

Faculty Publications

The current research aimed to evaluate the potential effects of Solanum mammosum, Dioon mejiae, and Amanita caesarea on Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus survival and performance after exposure to different harsh conditions such as bile, acid, gastric juice, and lysozyme to mimic the digestive system from mouth to the intestine. Probiotic protease activity was observed to evaluate the proteolytic system. Probiotics were cultured in a broth mixed with plant material, and after incubation, the results were compared to the control sample. Therefore, plant material’s total phenolic compound, total carotenoid compound, antioxidant activity, sugar profile, and acid profile were …

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Yolov4_Cspbi: Enhanced Land Target Detection Model, Lirong Yin, Lei Wang, Jianqiang Li, Siyu Lu, Jiawei Tian, Zhengtong Yin, Shan Liu, Wenfeng Zheng Sep 2023

Yolov4_Cspbi: Enhanced Land Target Detection Model, Lirong Yin, Lei Wang, Jianqiang Li, Siyu Lu, Jiawei Tian, Zhengtong Yin, Shan Liu, Wenfeng Zheng

Faculty Publications

The identification of small land targets in remote sensing imagery has emerged as a significant research objective. Despite significant advancements in object detection strategies based on deep learning for visible remote sensing images, the performance of detecting a small and densely distributed number of small targets remains suboptimal. To address this issue, this study introduces an improved model named YOLOV4_CPSBi, based on the YOLOV4 architecture, specifically designed to enhance the detection capability of small land targets in remote sensing imagery. The proposed model enhances the traditional CSPNet by redefining its channel partitioning and integrating this enhanced structure into the neck …

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Acceleration Of Turbulent Combustion Dns Via Principal Component Transport, Anuj Kumar, Martin Rieth, Opeoluwa Owoyele, Jacqueline H. Chen, Tarek Echekki Sep 2023

Acceleration Of Turbulent Combustion Dns Via Principal Component Transport, Anuj Kumar, Martin Rieth, Opeoluwa Owoyele, Jacqueline H. Chen, Tarek Echekki

Faculty Publications

We investigate the implementation of principal component (PC) transport to accelerate the direct numerical simulation (DNS) of turbulent combustion flows. The acceleration is achieved using the transport of PCs and the tabulation of the closure terms in the PC-transport equations using machine learning. Further acceleration is achieved by a treatment for bottlenecks associated with the acoustic time steps for low Mach number flows. The approach is implemented in 2D and 3D on a laboratory scale lean premixed methane-air flame stabilized on a slot burner. DNS based on the transport of thermochemical scalars (species and energy) is also carried out, first …

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Investigation Of Welding Repair Methods For Thermoplastic Composite Joints, Wencai Li, Genevieve Palardy Sep 2023

Investigation Of Welding Repair Methods For Thermoplastic Composite Joints, Wencai Li, Genevieve Palardy

Faculty Publications

Repair is a common process to extend the service life of composite structures, and there is a need for techniques compatible with thermoplastic composites (TPCs). As the assembly of TPC joints through welding is gaining importance, evaluating their potential for repairability is essential. This work aims to develop novel techniques to repair welded TPC joints: 1) Successive repair (three cycles) of broken joints by ultrasonic-assisted method with neat and nanocomposite films, and 2) one-step repair using ultrasonic welding (USW) and resistance heating. It was found from tensile testing that multi-walled carbon nanotube/polypropylene (MWCNT/PP) films partially restored the lap shear strength …

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A Sensitive Strain Sensor Based On Multi-Walled Carbon Nanotubes/Polyaniline/Silicone Rubber Nanocomposite For Human Motion Detection, Seyedmajid Hosseini, Mohsen Norouzi, Jian Xu Sep 2023

A Sensitive Strain Sensor Based On Multi-Walled Carbon Nanotubes/Polyaniline/Silicone Rubber Nanocomposite For Human Motion Detection, Seyedmajid Hosseini, Mohsen Norouzi, Jian Xu

Faculty Publications

Strain sensors play a pivotal role in quantifying stress and strain across diverse domains, encompassing engineering, industry, and medicine. Their applicability has recently extended into the realm of wearable electronics, enabling real-time monitoring of body movements. However, conventional strain sensors, while extensively employed, grapple with limitations such as diminished sensitivity, suboptimal tensile strength, and susceptibility to environmental factors. In contrast, polymer-based composite strain sensors have gained prominence for their capability to surmount these challenges. The integration of carbon nanotubes (CNTs) as reinforcing agents within the polymer matrix ushers in a transformative era, bolstering mechanical strength, electrical conductivity, and thermal stability. …

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Cybercompetitions: A Survey Of Competitions, Tools, And Systems To Support Cybersecurity Education, Tyler Balon, Ibrahim (Abe) Baggili Sep 2023

Cybercompetitions: A Survey Of Competitions, Tools, And Systems To Support Cybersecurity Education, Tyler Balon, Ibrahim (Abe) Baggili

Faculty Publications

Over the last decade, industry and academia have worked towards raising students’ interests in cybersecurity through game-like competitions to fill a shortfall of cybersecurity professionals. Rising interest in video games in combination with gamification techniques make learning fun, easy, and addictive. It is crucial that cybersecurity curricula enhance and expose cybersecurity education to a diversified student body to meet workforce demands. Gamification through cybercompetitions is one method to achieve that. With a vast list of options for competition type, focus areas, learning outcomes, and participant experience levels we need to systematize knowledge of attributes that ameliorate cybercompetitions. In the wake …

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Assessing The Threat Of Rosetta 2 On Apple Silicon Devices, Raphaela Mettig, Charles Glass, Andrew Case, Golden G. Richard Sep 2023

Assessing The Threat Of Rosetta 2 On Apple Silicon Devices, Raphaela Mettig, Charles Glass, Andrew Case, Golden G. Richard

Faculty Publications

In November 2020, Apple introduced a new architecture, Apple Silicon, that would power all new laptops and desktops. Based on ARM64 and with many custom features added by Apple, this marked a complete switch from the Intel-based systems that have powered Apple laptops and desktops for many years. With such a radical change, it was obvious that many existing digital forensics and incident response techniques would need to be re-evaluated on the platform. Similarly, several new additions to the operating system are interesting as potential abuse vectors for malware and malicious actors. In this paper, we document our effort to …

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Bim And Digital Twins In Infrastructure Projects: An Overview From The Transportation Professional's Perspective, Natállia Mendes Aug 2023

Bim And Digital Twins In Infrastructure Projects: An Overview From The Transportation Professional's Perspective, Natállia Mendes

LSU Master's Theses

Transport infrastructure has undergone significant changes in recent years due to the digitalization of construction methods. Consequently, there is an increasing demand for more productive and cost-effective technologies to optimize various aspects such as time, cost, changes, waste, and errors in projects. Notably, technologies such as Building Information Modeling (BIM) and Digital Twin (DT) hold the potential to enhance the performance of infrastructure projects. While BIM has received substantial attention in recent years, Digital Twin is relatively new to the construction industry. This leads to a scarcity of studies on DT and its integration with other emerging technologies like BIM. …

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Design And Implementation Of An Instrument Package For Measuring Process Conditions In An Expeller, Md Masud Rana Aug 2023

Design And Implementation Of An Instrument Package For Measuring Process Conditions In An Expeller, Md Masud Rana

LSU Master's Theses

The expeller process variable has gained increasing attention in research to validate process flow models. The expeller process is a mechanical method used to extract oil and water from seeds, nuts and polymers. Various factors, such as the speed of the press, size, and shape of the expeller, temperature, pressure, and moisture content, impact the efficiency and quality of the oil and water extraction process. By understanding these variables, researchers can develop accurate process flow models to predict the efficiency and quality of the oil and water extraction process. In this research, A custom instrumentation package have designed and implemented …

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Evaluation Of Organic And Synthetic Herbicides Applications On Indicators Of Soil Health And Weed Suppression In A Conventional Cropping System In Louisiana, Caitlin Denux Aug 2023

Evaluation Of Organic And Synthetic Herbicides Applications On Indicators Of Soil Health And Weed Suppression In A Conventional Cropping System In Louisiana, Caitlin Denux

LSU Doctoral Dissertations

Synthetic herbicides, with their varying modes of action, are well known for their efficiency in the suppression and control of weed species in U.S. agriculture. However, the consequences of using synthetic herbicides without attention to the surrounding environment can produce chemical run-off, changes in soil health and soil health conditions, and create herbicide-resistant weeds. These consequences have encouraged growers to find alternatives in their weed management programs. In this study, organic and synthetic herbicides were assessed on how well they performed in weed suppression surveys, and their potential effects on soil health indicators. Commonly used indicators include soil pH, β-glucosidase …

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The Fabrication Of Nearly Monodisperse Chiral And Achiral Plasmonic Nanostructures And Their Applications, Macayla J. Caso Aug 2023

The Fabrication Of Nearly Monodisperse Chiral And Achiral Plasmonic Nanostructures And Their Applications, Macayla J. Caso

LSU Doctoral Dissertations

An object is chiral when it holds no lines of symmetry. This quality naturally occurs in chemistry and biology. When an object is chiral it has a unique handedness and objects of opposite chirality are called enantiomers. The importance of handedness was brought to light in the 1960’s when a racemic mixture of thalidomide enantiomers was given to pregnant women. One enantiomer was able to treat morning sickness while the other caused severe birth defects. This case brought to light how enantiomers have unique properties from each other even though they are similar materials. With this knowledge chiral nanomaterials must …

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Monodisperse Sub-100 Nm Au Nanoshells For Low-Fluence Deep-Tissue Photoacoustic Imaging, Luis D.B. Manuel, Vinoin Devpaul Vincely, Carolyn L. Bayer, Kevin M. Mcpeak Aug 2023

Monodisperse Sub-100 Nm Au Nanoshells For Low-Fluence Deep-Tissue Photoacoustic Imaging, Luis D.B. Manuel, Vinoin Devpaul Vincely, Carolyn L. Bayer, Kevin M. Mcpeak

Faculty Publications

Nanoparticles with high absorption cross sections will advance therapeutic and bioimaging nanomedicine technologies. While Au nanoshells have shown great promise in nanomedicine, state-of-the-art synthesis methods result in scattering-dominant particles, mitigating their efficacy in absorption-based techniques that leverage the photothermal effect, such as photoacoustic (PA) imaging. We introduce a highly reproducible synthesis route to monodisperse sub-100 nm Au nanoshells with an absorption-dominant optical response. Au nanoshells with 48 nm SiO2 cores and 7 nm Au shells show a 14-fold increase in their volumetric absorption coefficient compared to commercial Au nanoshells with dimensions commonly used in nanomedicine. PA imaging with Au nanoshell …

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A Multi-Aerial Vehicle Platform For Testing Collaborative Mobility Formation Controllers, Matthew Snellgrove Aug 2023

A Multi-Aerial Vehicle Platform For Testing Collaborative Mobility Formation Controllers, Matthew Snellgrove

LSU Master's Theses

Multi-agent systems have potential applications in a multitude of fields due to their ability to perform complex tasks with a high degree of robustness. Decentralized systems are multi-agent systems where sensing, control, and communication responsibilities are distributed amongst the agents giving this scheme a particularly high potential for robustness, adaptability, and complexity; however, this comes with its own list of challenges. Formation control is a topic in multi-agent systems that aims to have the agents moving as a virtual rigid body through space. In the literature, there have been successful implementation of formation control algorithms on robot agents in both …

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Failure Analysis Of Light Poles On Highway Bridges Exposed To Extreme Winds, Yanlin Chen Aug 2023

Failure Analysis Of Light Poles On Highway Bridges Exposed To Extreme Winds, Yanlin Chen

LSU Master's Theses

Light poles are critical secondary structural components that support the functionality and safety of transportation systems. However, they are tall slender structures vulnerable to wind load. This research attempts to analyze the mechanism of the widespread failure (69 poles failed) of light poles on an elevated highway bridge exposed to Category 4 Hurricane Laura (2020). To understand the mechanism of the failure, a comprehensive analysis is conducted. A nonlinear finite element model is created to simulate the structural responses. Wind pressures are obtained and applied to the FEM to perform nonlinear static and transient analysis. Research results indicate that, when …

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Modeling Of Heat And Mass Transfer In Flat Heat Pipes, Salar Saadatian Aug 2023

Modeling Of Heat And Mass Transfer In Flat Heat Pipes, Salar Saadatian

LSU Doctoral Dissertations

Phase-change phenomenon is ubiquitous in nature and widely utilized in thermal management of computer chips. Flat heat pipes have been extensively used in thermal management of microelectronic devices. However, existing research mainly concentrates on developing numerical models and lacks a systematic analytical approach to elucidate the working mechanism of flat heat pipes. We consider a horizontal flat heat pipe with an idealized porous wick. The pores in the wick are straight circular capillaries running along and across the wick and are filled with a liquid. The rest of the pipe is filled with its vapor. The mass evaporative rate at …

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Investigating The Influence Of Portland Limestone Cement Combined With Sugarcane Bagasse Ash And Different Types Of Fly Ash On The Mechanical Properties Of Engineered Cementitious Composites, Samuel Guidroz Aug 2023

Investigating The Influence Of Portland Limestone Cement Combined With Sugarcane Bagasse Ash And Different Types Of Fly Ash On The Mechanical Properties Of Engineered Cementitious Composites, Samuel Guidroz

LSU Master's Theses

The ability to implement Engineered Cementitious Composites (ECC) within our transportation infrastructure systems has been limited because of increased costs associated with the material’s high cement quantity. To improve cost- effectiveness and to create a more sustainable footprint, the use of supplementary cementitious materials (SCMs) has been explored. This study evaluated the effects of utilizing cement interground with limestone, Portland limestone cement (PLC), as a replacement for ordinary Portland cement (OPC). Additionally, the performance of the composites was analyzed when mixed with sugarcane bagasse ash (SCBA) as well as different classes of fly ash (FA). In doing so, the experimental …

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Ph-Dependent Solution Micellar Structure Of Amphoteric Polypeptoid Block Copolymers With Positionally Controlled Ionizable Sites, Meng Zhang, Yun Liu, Xiaobing Zuo, Shuo Qian, Sai Venkatesh Pingali, Richard E. Gillilan, Qingqiu Huang, Donghui Zhang Aug 2023

Ph-Dependent Solution Micellar Structure Of Amphoteric Polypeptoid Block Copolymers With Positionally Controlled Ionizable Sites, Meng Zhang, Yun Liu, Xiaobing Zuo, Shuo Qian, Sai Venkatesh Pingali, Richard E. Gillilan, Qingqiu Huang, Donghui Zhang

Faculty Publications

While solution micellization of ionic block copolymers (BCP) with randomly distributed ionization sites along the hydrophilic segments has been extensively studied, the roles of positionally controlled ionization sites along the BCP chains in their micellization and resulting micellar structure remain comparatively less understood. Herein, three amphoteric polypeptoid block copolymers carrying two oppositely charged ionizable sites, with one fixed at the hydrophobic terminus and the other varyingly positioned along the hydrophilic segment, have been synthesized by sequential ring-opening polymerization method. The presence of the ionizable site at the hydrophobic segment terminus is expected to promote polymer association toward equilibrium micellar structures …

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Black Experiences With Community Gardening In Southeast Louisiana, Kiarah Craft Aug 2023

Black Experiences With Community Gardening In Southeast Louisiana, Kiarah Craft

LSU Master's Theses

Community gardens have been rising in popularity over the past few years (Mayers, 2023). In response to the COVID-19 pandemic, many people across the United States have decided that it is crucial to grow their own food and develop sustainability within their community. Historically, Black communities have been underserved and ignored, especially in relation to food security and community safety (White, 2019, Penniman, 2018). The purpose of this study was to collect information about the effects of community-based gardening programs on Black people in Southeast Louisiana. Additionally, the researcher would like to gain knowledge regarding the reasons that Black people …

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Autonomous Shipwreck Detection & Mapping, William Ard Aug 2023

Autonomous Shipwreck Detection & Mapping, William Ard

LSU Master's Theses

This thesis presents the development and testing of Bruce, a low-cost hybrid Remote Operated Vehicle (ROV) / Autonomous Underwater Vehicle (AUV) system for the optical survey of marine archaeological sites, as well as a novel sonar image augmentation strategy for semantic segmentation of shipwrecks. This approach takes side-scan sonar and bathymetry data collected using an EdgeTech 2205 AUV sensor integrated with an Harris Iver3, and generates augmented image data to be used for the semantic segmentation of shipwrecks. It is shown that, due to the feature enhancement capabilities of the proposed shipwreck detection strategy, correctly identified areas have a 15% …

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Computational Investigations Of The Water Structure At The Α-Al2o3(0001)-Water Interface, Xiaoliu Zhang, Christopher G. Arges, Revati Kumar Aug 2023

Computational Investigations Of The Water Structure At The Α-Al2o3(0001)-Water Interface, Xiaoliu Zhang, Christopher G. Arges, Revati Kumar

Faculty Publications

The α-Al2O3(0001)-water interface is investigated using ab initio molecular dynamics (AIMD) simulations. The spectral signatures of the vibrational sum frequency generation (vSFG) spectra of OH stretching mode for water molecules at the interface are related to the interfacial water orientation, hydrogen bond network, and water dissociation process at different water/alumina interfaces. Significant differences are found between alumina surfaces at different hydroxylation levels, namely, Al-terminated and O-terminated α-Al2O3(0001). By calculating the vibrational sum frequency generation spectrum and its imaginary component from AIMD results, the structure of interfacial waters as well as the termination of alumina slab are related to the spectral …

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An Occupant-Centric Energy Modeling And Simulation In Office Buildings, Seddigheh Norouziasl Aug 2023

An Occupant-Centric Energy Modeling And Simulation In Office Buildings, Seddigheh Norouziasl

LSU Doctoral Dissertations

Building energy use is highly sensitive to occupants’ energy-related behaviors, including their presence and interaction with different building systems. Modeling and simulation of occupants’ energy-related behavior play an essential role in accurately predicting building energy consumption. Simplifying occupancy parameters in building performance simulation tools can lead to discrepancies between the simulated and actual building energy performance. The main goal of this research is to simulate the occupants’ energy-related behavior in office buildings and utilize the occupancy data to accurately predict building energy performance. Our objective is to increase building energy efficiency and reduce energy consumption while ensuring occupants' comfort, especially …

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On The Evaluation Of Entropy Threshold For Debonding During Crack Prorogation Using Dic Technique, A. Mahmoudi, M. R. Khosravani, M. M. Khonsari, Tamara Reinicke Aug 2023

On The Evaluation Of Entropy Threshold For Debonding During Crack Prorogation Using Dic Technique, A. Mahmoudi, M. R. Khosravani, M. M. Khonsari, Tamara Reinicke

Faculty Publications

The accumulated entropy at the crack tip of a semi-circular bending (SCB) specimen is investigated to obtain a threshold for material fracture and interatomic debonding. The presented approach uses the experimental data obtained from the Digital Image Correlation (DIC) technique and strain maps superposed to SCB specimens to measure the plastic flow at the crack tip. The Swift strain hardening model is utilized to calculate the stress domain at the crack tip and, consequently, the plastic strain energy and entropy accumulation. Results show that the crack surface propagates when the generated entropy at the crack tip reaches a critical limit. …

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