Digital Commons Network^™

Damage Monitoring Methods For Fiber-Reinforced Polymer Joints: A Review, Wencai Li, Genevieve Palardy

Faculty Publications

As the application of composite materials in structural parts continues to increase, so does the importance to monitor the structure's health condition during their entire service life. This paper presents a comprehensive review on damage monitoring methods focusing on fiber-reinforced polymer joints: adhesively bonded, mechanically fastened, and welded. In this review, structural health monitoring (SHM) methods are classified into two major groups: intrinsic sensing (embedded at the bond line) and extrinsic sensing (placed outside the interface). Main intrinsic techniques include fiber optic sensors, piezoelectric sensors (e.g., electromechanical impedance), and nanocomposite-based monitoring. The latter has attracted significant interest in the past …

Design And Economic Analysis Of A Hydrokinetic Turbine For Household Applications, Carmen M. Puertas-Frías, Clinton S. Willson, Pablo A. García-Salaberri

Faculty Publications

Social and political concerns on climate change have made renewable energy an essential component of government's work plans. Grid-connected horizontal-axis hydrokinetic turbines are promising eco-friendly power sources for electrical energy supply to households near middle-to-high discharge rivers, while providing an opportunity to sell the energy surplus. In this work, a rotor design analysis of a hydrokinetic turbine with a 1 m nominal radius is performed based on blade element momentum theory. Then, an economic analysis is presented in terms of the discounted payback period and the internal rate of return. The numerical results show that three-bladed hydrokinetic turbines with a …

Subpredictor Approach For Event-Triggered Control Of Discrete-Time Systems With Input Delays, Frédéric Mazenc, Michael Malisoff, Corina Barbalata, Zhong Ping Jiang

Faculty Publications

We propose a new output event-triggered control design for linear discrete-time systems with constant arbitrarily long input delays, using delay compensating subpredictors. We prove input-to-state stability of the closed loop system, using framers and the theory of positive systems. A novel feature of our approach is our use of matrices of absolute values, instead of Euclidean norms, in our discrete-time event triggers for our delay compensating control design. We illustrate our approach using a model of the BlueROV2 marine vehicle, where our new event triggers lead to a smaller number of control recomputation times as compared with standard event triggers …

A Machine Learning Approach For Detecting Rescue Requests From Social Media, Zheye Wang, Nina S.N. Lam, Mingxuan Sun, Xiao Huang, Jin Shang, Lei Zou, Yue Wu, Volodymyr V. Mihunov

Faculty Publications

Hurricane Harvey in 2017 marked an important transition where many disaster victims used social media rather than the overloaded 911 system to seek rescue. This article presents a machine-learning-based detector of rescue requests from Harvey-related Twitter messages, which differentiates itself from existing ones by accounting for the potential impacts of ZIP codes on both the preparation of training samples and the performance of different machine learning models. We investigate how the outcomes of our ZIP code filtering differ from those of a recent, comparable study in terms of generating training data for machine learning models. Following this, experiments are conducted …

Time-Varying Rates Of Organic And Inorganic Mass Accumulation In Louisiana Marshes And Relation To Sea-Level Change, Sophie Vincent

LSU Master's Theses

Louisiana wetlands are complex systems that require a continuous input of organic and inorganic material to keep pace with relative sea-level rise (RSLR). Marshes, specifically, rely on organic material to build soil volume and maintain surface elevation. Interannual-to-decadal sea-level anomalies induced by Earth's internal climate variability and atmospheric disturbances such as hurricanes can affect marsh accretion, mineral deposition, and plant productivity. Coastal restoration projects such as sediment diversions are in progress to mitigate land loss and increase availability of inorganic sediment to coastal wetlands. The goal of this project is to determine if organic mass accumulation rates in Louisiana marshes …

Improvements To The Automatic Calibration Of Digital Focusing Color Schlieren Systems, Robert C. Frazee

LSU Master's Theses

As a diagnostic method, Schlieren imaging offers the unique ability to visualize flows with a completely non-intrusive method. By visualizing small changes in the refractive index of a fluid, Schlieren imaging is able to visualize changes in temperature, pressure, and composition. While historic Schlieren methods have been limited to providing largely qualitative information, modern Schlieren methods are able to extract quantitative information from flow phenomena. This is possible through either Background Oriented Schlieren (BOS) or Digital Focusing Color Schlieren (DFCS) methods. While BOS is relatively flexible, it requires a large amount of computational effort to process each frame of captured …

A Performance Guide To Michael Patterson's "People Of The Land" For Baritone And Piano, Thaddeus Harm Ennen

LSU Doctoral Dissertations

The purpose of this document is to supply a comprehensive performer’s guide to Iowa composer, Dr. Michael Patterson’s, People of the Land, an eight song, song cycle for baritone and piano, set to poetry by Iowa poet James Hearst. This song cycle was personally commissioned to fulfill a need in the American song cycle literature on the topic of farming and more specifically Iowa farmers. The poetry of James Hearst, farmer and poet, has never been previously set in a song cycle.

People of the Land tells the story of an Iowa farmer from the beginning to end of …

Polymer Mimetics For Soil Modeling And Detection Of Biomarkers, Md Ragib Hasan

LSU Doctoral Dissertations

The population of the world is increasing day by day and is expected to reach 9.8 billion by the year 2050. The ever-increasing demand for agricultural products is putting an unprecedented strain on the world's soils as the human population continues to expand. Soil degradation caused by over-farming and the agrochemicals (fertilizers, pesticides, etc.) used in agriculture is a growing problem, although its causes remain murky. In addition, little is understood about the molecular-level interactions of substances that are subsequently introduced to soils, such as agricultural chemicals (ACs). Therefore, it is expected that these constraints may be circumvented by the …

Shaky Ground: Educators At The Intersection Of Gender Diversity And Early Childhood Environments, Elizabeth Gragg Elizardi

LSU Doctoral Dissertations

This dissertation examines the hidden curriculum of gender socialization in early childhood classrooms. Purposes of this study included exploring how teachers’ beliefs about gender are enacted in activities, roles, and relationships with children to inform and recommend future directions for gender conscious education and pedagogies. This dissertation includes an assessment of participants’ gender schema, an analysis of participant interviews and focus groups, field notes from classroom observations and artifact collection. This study draws on Brofenbrenner’s (2005) bioecological theory of human development, positioning teachers as a primary engine of development in a child’s life. Cognitive-developmental theories are forwarded to explain gender …

Religiosity And Misperceptions: The Effect Of Americans’ Religious Involvement On Their (Mis)Perceptions Of Political Parties, Rehm Nathanael Maham

Honors Capstones

No abstract provided.

Impact Of The Choice Of Acidic Buffers On The Electrochemical Reduction Of Hexavalent Chromium In Water, Devin D. Meche

Honors Capstones

No abstract provided.

In Defense Of The General: George Washington’S Aides-De-Camp And Their Campaign To Protect The Commander-In-Chief, Chloe Pellegrin

Honors Capstones

No abstract provided.

Comparison Of Two Capital Cost Assessment Methods For A Styrene Process Design, Marian K. Luzier

Honors Capstones

No abstract provided.

Challenging The Canon; Teaching The Literary Canon In The High School Classroom, Abigail Baumgartner

Honors Capstones

No abstract provided.

Title Ix: A Discovery Of Its Failure To Protect Students From Sexual Harassment And Assault, Delaney Ferrer

Honors Capstones

No abstract provided.

Low-Cost Sustainable Engineered Geopolymer Composites (Egcs) For Repair And New Construction Of Transportation Infrastructure, Hassan Noorvand, Marwa Hassan, Miladin Radovic, Svetlana Sukhishvili, Gabriel Arce, Ruwa Abufarsakh, Adriana A. Alvarado, Oscar Huang, Sang Zhen

Publications

This study evaluated the use of cost-effective alternative materials in the formulation of novel low-cost Engineered Geopolymer Composite (EGC) materials for repair and new construction of transportation infrastructure in Region 6. Previous studies and reports have shown that EGCs have excellent mechanical properties, which makes them an eco-friendly and more sustainable alternative to Engineered Cementitious Composites (ECCs). However, the mass adoption of these emerging composites is expected to be hindered by their cost, which is mainly driven by the use of PVA reinforcing fibers, silica fume (SF), and manufactured microsilica sand (MS). To address this key shortcoming, novel low-cost EGC …

Development Of Robotics & Automation Roadmap For Road Construction/Maintenance Projects, Ashrant Aryal, Chao Wang, Chintan Vijay Vora, Sueed A. Willoughby

Publications

Over the past few decades, there have been no significant improvements in the construction industry's productivity. Outside the construction industry, robots have proven to be beneficial in improving productivity, safety, and quality. There is a growing interest in adopting robots in the construction industry to address these issues. As robots get introduced to the project sites, human-robot interaction becomes an important consideration for wide-scale adoption. The success of deploying robots in the construction industry depends on how well humans collaborate with the robots. This project focused on investigating the perception of various construction industry stakeholders in adopting robots in their …

“You Can’T Wash Your Hands In A House Without Running Water”: Pandemic Precautionary Behaviors In The Wake Of Hurricane Laura, Cécile Girard

Honors Capstones

No abstract provided.

Uvite, Camg 3 (Al5mg)(Si6o18)(Bo3)3(Oh)3(Oh), A New, But Long-Anticipated Mineral Species Of The Tourmaline Supergroup From San Piero In Campo, Elba Island, Italy, Ferdinando Bosi, Cristian Biagioni, Federico Pezzotta, Henrik Skogby, Ulf Hålenius, Jan Cempírek, Frank C. Hawthorne, Aaron J. Lussier, Yassir A. Abdu, Maxwell C. Day, Mostafa Fayek, Christine M. Clark, Joel D. Grice, Darrell J. Henry

Faculty Publications

Uvite, CaMg3(Al5Mg)(Si6O18)(BO3)3(OH)3(OH), is a new mineral of the tourmaline supergroup. It occurs in the Facciatoia quarry, San Piero in Campo, Elba Island, Italy (42°45′04.55″N, 10°12′50.89″E) at the centre of a narrow (2-3 cm wide) vein composed of aggregates of dark brown to black tourmaline, penetrating (magnesite + dolomite)-rich hydrothermally altered metaserpentinite. Crystals are euhedral and up to 1 cm in size, brown with a vitreous lustre, conchoidal fracture and grey streak. Uvite has a Mohs hardness of 7½, a calculated density of 3.115 g/cm3 and is uniaxial (-). Uvite has trigonal symmetry, space group R3m, a = 15.9519(10) Å, c …

Immunohistochemical Localization Of Kisspeptin And Its Receptor In The Equine Ovary, Bryce M. Gilbert

LSU Master's Theses

Kisspeptin is recognized for its role as the gatekeeper of reproduction in most mammalian species. However, its role in regulation of reproduction at the ovarian level is poorly understood in the horse. In this study, ovaries from follicular phase, luteal phase, anestrous period, and mares treated with ECP-sulpiride were subjected to immunohistochemistry to characterize kisspeptin-10 (Kp10) and its receptor (Kiss1r) protein expression throughout each reproductive stage and follicle type. Kisspeptin and receptor staining was detected in all follicle types (primordial, preantral, and antral) throughout all reproductive stages, as well as oocytes, corpora lutea, and ovulation fossa. The pattern of Kp10 …

Application Of Direct Feedback Tunable Diode Laser Absorption Spectroscopy Within A Hybrid Rocket Combustor, Connor Becnel

LSU Master's Theses

With interest in space travel and space-related science increasing in recent years, significant efforts to reduce the cost and increase the safety of rocket motors have become commonplace. Liquid rockets are currently the most commonly used system, but there is interest in the reduced complexity of hybrid rockets. For these hybrid rocket motors to become the norm, extensive research on their complex boundary layer combustion needs to be performed. Modeling these hybrid systems is of much interest to companies developing rocket motors; ultimately, small-scale experiments will help validate their behavior. This paper covers the application of a near-infrared tunable diode …

Narcissism And Risk-Taking For Others, Tyler B. Cowley

LSU Master's Theses

While prior findings demonstrate that narcissists are excessively risk-seeking for themselves, research does not yet understand if their risk-seeking behaviors extend to others as well. This paper examines the role of narcissism in risk-taking on behalf of others. I hypothesize that narcissists will take more risks when deciding for others because they lack empathy and perspective taking. Therefore, narcissists are more likely to take risks based on their personal preferences, rather than the recipient’s desires. To test my hypotheses, participants completed the Balloon Analogue Risk Task (BART) for themselves, another individual, and an anonymous individual, followed by completing the Narcissistic …

Defining Change Beyond A Binary System: Measurement And Interpretation Of Degrees Of Dysphonia Severity In The Individual And Across Voice Disorders, Lindsey Ann Parker

LSU Doctoral Dissertations

Objective: The current study examined the sensitivity of voice outcome measures in discriminating cut-off thresholds between degrees of dysphonia severity, correlations to perceived dysphonia, and the impact of vocal task. Differences between cases of adductor spasmodic dysphonia, benign vocal fold polyps, and unilateral vocal fold paralysis were also explored.

Method: Auditory-perceptual judgments were performed by three raters for four diagnostic groups: Normal (n=14), AdSD (n=15), Polyp (n=15) and UVFP (n=15). Receiver operator characteristic area under the curve (AUC) analyses established screening and dysphonia severity (mild, moderate, severe) cut-off thresholds for auditory-perceptual visual analog scale (VAS) ratings and acoustic measures (f0_SD, …

Investigating The Relational Element Of Trust In Teacher-Principal Relationships: An Autoethnographic Case Study, Angela Bradley

LSU Doctoral Dissertations

This autoethnographic case study was designed to investigate the relational aspect of trust, a characteristic of servant leadership, in the teacher-principal relationship. This trusting bond is an often overlooked, foundational element of a school’s success. I examined the role that trust plays in enhancing a school’s culture and how trust is established and maintained among one principal and teachers under my supervision. In addition, as researcher, I sought to uncover specific indicators that trust was present on a school campus. Finally, I sought to examine trust’s effects on collaboration and organizational commitment.

Through weekly reflections, I sought to examine my …

Hydrogeologic Investigation Of A Covered Karst Terrain, Joseph Peter Honings

LSU Doctoral Dissertations

Increasing demand for water for agricultural use within the Dougherty Plain of the Southeastern United States has depleted surface water bodies. In karstic landscapes, such as the Dougherty Plain in southwest Georgia where the linkages between surface and ground waters are close, there is a need to understand the physical characteristics of the subsurface that allow these close linkages. Having a better understanding of the subsurface characteristics will aid numerical modeling efforts that underpin policy decisions and economic analyses. Two common features on this karstic landscape are draws and geographically isolated wetlands. Using LiDAR, aerial imagery, and ground-penetrating radar, this …

Phase Transitions And Photoluminescent Properties Of Anion-Engineered Y2o3, Maharram Jabrayilov

LSU Master's Theses

Rare earth doped metal oxides are widely employed as phosphor materials for white light LEDs (w-LEDs). The aim of this work is to engineer anionic sites of metal oxides, specifically, Y₂O₃, to investigate structural and luminescent properties relationships and energy transfer mechanisms between rare earth sensitizer and activator ions in different hosts.

A low temperature two-step hydrothermal/combustion method was employed to incorporate sulfate ions into Y₂O₃. Furthermore, annealing at 600 °C under H₂/N₂ was employed to convert Y₂O₂SO₄ to Y₂O₂S. …

Thermal Stability And Protective Properties Of Phenylphosphonic Acid On Cu(111), Viacheslav Kalinovych, Md Saeedur Rahman, Lesia Piliai, Yuliia Kosto, Sascha L. Mehl, Tomáš Skála, Iva Matolínová, Vladimír Matolín, Kevin C. Prince, Ye Xu, Nataliya Tsud

Faculty Publications

Phenylphosphonic acid (PPA) adsorbed on Cu(111) has been studied by synchrotron radiation-based techniques in combination with density functional theory calculations. The dehydrogenated phenylphosphonic acid molecule (PP) strongly bound in a tridentate geometry through oxygen atoms to Cu(111) is shown to be the dominant surface species in the temperature range 150–300 °C. The stable PP adlayer substantially protects the Cu(111) surface from oxidation during exposure to ambient conditions. Thermal treatment of the PPA adlayer at 375 °C initiates molecular decomposition through several channels: P–O bond scission forming C6H5PO2; C–P bond scission forming phenyl and PO3; and C–H bond scission forming C6H4PO3. …

Ribbon Homology Cobordisms, Aliakbar Daemi, Tye Lidman, David Shea Vela-Vick, C. M.Michael Wong

Faculty Publications

We study 4-dimensional homology cobordisms without 3-handles, showing that they interact nicely with Thurston geometries, character varieties, and instanton and Heegaard Floer homologies. Using these, we derive obstructions to such cobordisms. As one example of these obstructions, we generalize other recent results on the behavior of knot Floer homology under ribbon concordances. Finally, we provide topological applications, including to Dehn surgery problems.

A Membrane Transporter Required For Quorum Sensing And Virulence Of The Rice Pathogen Burkholderia Glumae, Asif Iqbal

LSU Doctoral Dissertations

Burkholderia glumae is a Gram-negative bacterium causing bacterial panicle blight (BPB) in rice. BPB can cause severe damage to rice and reduce rice yield up to 75%, while no effective treatment has been developed to control the disease. B. glumae produces and secretes an essential virulence factor, toxoflavin, which is mainly responsible for the symptoms of BPB. Synthesis and transport of toxoflavin are regulated in a quorum-sensing dependent manner. Members of the DedA superfamily are putative membrane transporters and found in nearly all species. Mutation of dedA in Burkholderia species results in sensitivity to colistin, an antibiotic belonging to the …

Device Free Indoor Localization Of Human Target Using Wifi Fingerprinting, Prasanga Neupane

LSU Master's Theses

Indoor localization of human objects has many important applications nowadays. Proposed here is a new device free approach where all the transceiver devices are fixed in an indoor environment so that the human target doesn't need to carry any transceiver device with them. This work proposes radio-frequency fingerprinting for the localization of human targets which makes this even more convenient as radio-frequency wireless signals can be easily acquired using an existing wireless network in an indoor environment. This work explores different avenues for optimal and effective placement of transmitter devices for better localization. In this work, an experimental environment is …