Digital Commons Network^™

Engineering The Lanthanide And Actinide Dopants Effects On The Local Environment Of Luminescent Complex Metal Oxide, Yuming Wang

LSU Doctoral Dissertations

Rare earth (RE) based phosphor materials are widely used as luminescent probes in high-temperature optical thermometry where standard methods are unsuitable. The current generation of luminescent thermometers lacks stability and energy transport within the operating temperature ranges. The challenge is developing an oxide-based material with high luminescence intensity and thermal sensitivity/stability, suitable for an optical temperature sensor/thermal barrier coating. This work aims to develop a fundamental understanding of the local environment surrounding RE or actinide dopants in metal oxide hosts to engineer their luminescence property. To maximize the luminescence, the local symmetry, doping concentration, and radiative/non-radiative relaxation pathways must be …

Optimizing The Performance Of Parallel And Concurrent Applications Based On Asynchronous Many-Task Runtimes, Weile Wei

LSU Doctoral Dissertations

Nowadays, High-performance Computing (HPC) scientific applications often face per- formance challenges when running on heterogeneous supercomputers, so do scalability, portability, and efficiency issues. For years, supercomputer architectures have been rapidly changing and becoming more complex, and this challenge will become even more com- plicated as we enter the exascale era, where computers will exceed one quintillion cal- culations per second. Software adaption and optimization are needed to address these challenges. Asynchronous many-task (AMT) systems show promise against the exascale challenge as they combine advantages of multi-core architectures with light-weight threads, asynchronous executions, smart scheduling, and portability across diverse architectures.

In …

Readymades & Repertoires: Artifact-Mediated Improvisation In Tabletop Role-Playing Games, Philip Tchernavskij, Andrew M. Webb, Hayden Gemeinhardt, Wendy E. Mackay

Faculty Publications

Game masters (GMs) are creative practitioners who plan and orchestrate tabletop role-playing games. Through an interview study, we investigate how eight expert game masters adapt everyday technologies and materials as creativity support tools (CSTs) for improvisational and collaborative play. We integrate theories of improvisational and distributed creativity with the human-artifact model, which provides an activity-theoretical vocabulary for analyzing the mediating relationships between specialist practitioners and their tools. We show how GMs prepare and deploy readymade artifacts: analog and digital CSTs that flexibly mediate recurring creative tasks in their practice, such as improvising narrative elements, facilitating smooth play, and creating aesthetic …

Integration Of Solar + Storage Installation Upstream In Modular Construction, Ondrej Labik

LSU Master's Theses

High initial costs, mainly due to inefficient construction processes, remains the greatest barrier for residential adoption of solar+storage (SPS) system. Modular construction, having a factory-controlled environment and control over the home design, is well suited to address these issues (e.g., efficiencies, waste, inventory control, quality). Furthermore, these areas have great potential in modular construction to address the high initial cost issue. This study focuses on the integration of SPS installation upstream in modular housing. Although moving the SPS installation process into the factory has many barriers (e.g., including change of scope of work at some workstations without affecting the whole …

Zein And Lignin-Graft-Plga Nanoparticles As Agrochemical Delivery Systems To Soybean Plants, Eban A. Hanna

LSU Master's Theses

The majority of applied agrochemicals are lost to the environment due to their poor adhesion to plant tissues, resulting in multiple applications and subsequent environmental toxicity. This thesis focuses on reducing these consequences by entrapping agrochemicals in polymeric nanoparticles (PNPs). In the first section, zein nanoparticles (ZNPs) with entrapped methoxyfenozide (MFZ) (209.0 ± 5.6 nm, -42.1 ± 2.1 mV) were synthesized and used to facilitate the translocation of MFZ to the leaves and stems of soybean plants, as measured by LC-MS, under hydroponic conditions. The agrochemical concentration increased within the leaves over time from 0.04 to 2.35 μg/g at 0.2 …

Self-Healing Composite Of Thermoset Polymer And Programmed Super Contraction Fibers, Guoqiang Li, Harper Meng

College of Engineering Patents

A composition comprising thermoset polymer, shape memory polymer to facilitate macro scale damage closure, and methods for molecular scale healing are provided. The composition can resolve structural defects by a bio-mimetic close-then heal process. In use, the shape memory polymer can provide molecular scale healing in a structural defect. The methods for molecular scale healing can include heating a composition including a thermoplastic such as fibers, particles or spheres to a level at or above the thermoplastic's melting point, then cooling of the composition below the melting temperature of the thermoplastic. The compositions have the ability to close macroscopic defects …

The Nexus Of The Indoor Co2 Concentration And Ventilation Demands Underlying Co2-Based Demand-Controlled Ventilation In Commercial Buildings: A Critical Review, Xing Lu, Zhihong Pang, Yangyang Fu, Zheng O'Neill

Faculty Publications

The carbon dioxide (CO2)-based demand-controlled ventilation (DCV) has attracted prompt attention from the Heating, Ventilation, and Air-Conditioning (HVAC) industry since its very first invention. Since then, it has been penetrating from simple single-zone systems to complex system configurations in commercial buildings. While there has accumulated a large number of research on DCV applications, the most recent review paper on this topic was dated back to 2001 and inevitably missed a lot of recent revolutionary technologies. Therefore, to understand the opportunities and challenges associated with the CO2-based DCV, this study presents a timely review on the revolutions of the CO2-based DCV …

Functional Coupling Of Trpm2 And Extrasynaptic Nmdars Exacerbates Excitotoxicity In Ischemic Brain Injury, Pengyu Zong, Jianlin Feng, Zhichao Yue, Yunfeng Li, Gongxiong Wu, Baonan Sun, Yanlin He, Barbara Miller, Albert S. Yu, Zhongping Su, Jia Xie, Yasuo Mori, Bing Hao, Lixia Yue

Division of Basic Science Faculty Publications

Excitotoxicity induced by NMDA receptor (NMDAR) activation is a major cause of neuronal death in ischemic stroke. However, past efforts of directly targeting NMDARs have unfortunately failed in clinical trials. Here, we reveal an unexpected mechanism underlying NMDAR-mediated neurotoxicity, which leads to the identification of a novel target and development of an effective therapeutic peptide for ischemic stroke. We show that NMDAR-induced excitotoxicity is enhanced by physical and functional coupling of NMDAR to an ion channel TRPM2 upon ischemic insults. TRPM2-NMDAR association promotes the surface expression of extrasynaptic NMDARs, leading to enhanced NMDAR activity and increased neuronal death. We identified …

From Equal-Mass To Extreme-Mass-Ratio Binary Inspirals: Simulation Tools For Next Generation Gravitational Wave Detectors, Samuel Douglas Cupp

LSU Doctoral Dissertations

Current numerical codes can successfully evolve similar-mass binary black holes systems, and these numerical waveforms contributed to the success of the LIGO Collaboration's detection of gravitational waves. LIGO requires high resolution numerical waveforms for detection and parameter estimation of the source. Great effort was expended over several decades to produce the numerical methods used today. However, future detectors will require further improvements to numerical techniques to take full advantage of their detection capabilities. For example, the Laser Interferometer Space Antenna (LISA) will require higher resolution simulations of similar-mass-ratio systems than LIGO. LISA will also be able to detect extreme-mass-ratio inspiral …

On-Line Phased Array Ultrasonic Testing System For Friction Stir Welding Applications, Daniel J. Huggett, Mohammad W. Dewan, Muhammad A. Wahab, Thunshun W. Liao, Ayman Okeil

College of Engineering Patents

A wedge for on-line inspection of a weld includes a wedge body defining a coolant channel and at least one couplant channel, and a coolant input port in fluid connection with a first end of the coolant channel. The wedge body has a surface for disposing a phased array ultrasonic transducer comprising an array of ultrasonic elements. The coolant channel is formed in proximity to the surface for disposing the phased array ultrasonic transducer such that coolant flowing through the coolant channel maintains the phased array ultrasonic transducer below a predetermined temperature without obstructing the array of ultrasonic elements.

Adaptive Solid-State Luminescent Phosphors, James A. Dorman

College of Engineering Patents

The absorbance or emission wavelength of composite materials comprising a transition metal doped shell disposed over a rare earth doped core and a functionalizable group on the surface of the transition metal doped shell can change upon subjection to a carboxylic acid. This method of changing the absorbance or emission wavelength of a composite material can be used to identify counterfeit currency using an ink comprising a composite material.

Governance Of Social Responsibility In International Infrastructure Megaprojects, Saixing Zeng, Hongquan Chen, Hanyang Ma, Jonathan Jingsheng Shi

Faculty Publications

No abstract provided.

Sweat (Summer, 2022), Lsu Swine Palace

Playbills

Filled with warm humor and tremendous heart, SWEAT tells the story of a group of friends who have spent their lives sharing drinks, secrets, and laughs while working together on the factory floor. But when layoffs and picket lines begin to chip away at their trust, the friends find themselves pitted against each other in a heart-wrenching fight to stay afloat.

Recursive Movements Of Eastern Wild Turkey Broods In The Southeastern United States, Nicholas W. Bakner, Bradley S. Cohen, Bret A. Collier, Michael J. Chamberlain

Faculty Publications

Productivity of wild turkey (Meleagris gallopavo) populations throughout the southeastern United States has declined over the past several decades. Although population trajectory is driven primarily by annual reproduction, wild turkey managers have little information regarding the behavioral ecology of broods immediately post-hatch. Broods are known to revisit areas within their ranges, but revisitation behavior is poorly understood spatially and temporally. Thus, identifying patterns of visitation and revisitation can increase understanding of brood behavior. We monitored 94 brooding females until brood failure or 28 days after hatch to evaluate movements and to quantify landcover and vegetation density at revisited locations which …

The North American Freshwater Migratory Fish Database (Nafmfd): Characterizing The Migratory Life Histories Of Freshwater Fishes Of Canada, The United States And Mexico, Emily M. Dean, Arthur R. Cooper, Lizhu Wang, Wesley Daniel, Solomon David, Clayton Ernzen, Keith B. Gido, Edward Hale, Tim J. Haxton, William Kelso, Nancy Leonard, Chris Lido, Joseph Margraf, Michael Porter, Casey Pennock, David Propst, Jared Ross, Michelle D. Staudinger, Gary Whelan, Dana M. Infante

Faculty Publications

Aim: Migratory freshwater fishes are those that must access discrete habitats to complete their life cycles. Freshwater fish migrations occur around the world and provide numerous ecosystem services for humans and natural systems; however, many migratory species are in decline globally. A limiting factor to successfully conserve freshwater migratory fishes is that the migratory life histories of many species are unknown or only partially described. To provide researchers with critical and comprehensive information to conserve migratory fishes, we developed the North American Freshwater Migratory Fish Database (NAFMFD). Location: Canada, Mexico and the United States. Taxon: Freshwater fish. Methods: To develop …

Loss Of Function Of Renal Glut2 Reverses Hyperglycaemia And Normalises Body Weight In Mouse Models Of Diabetes And Obesity, Leticia Maria De Souza Cordeiro, Lauren Bainbridge, Nagavardhini Devisetty, David H. Mcdougal, Dorien J.M. Peters, Kavaljit H. Chhabra

Division of Basic Science Faculty Publications

Aims/hypothesis: Renal GLUT2 is increased in diabetes, thereby enhancing glucose reabsorption and worsening hyperglycaemia. Here, we determined whether loss of Glut2 (also known as Slc2a2) specifically in the kidneys would reverse hyperglycaemia and normalise body weight in mouse models of diabetes and obesity. Methods: We used the tamoxifen-inducible CreERT2-Lox system in mice to knockout Glut2 specifically in the kidneys (Ks-Glut2 KO) to establish the contribution of renal GLUT2 to systemic glucose homeostasis in health and in insulin-dependent as well as non-insulin-dependent diabetes. We measured circulating glucose and insulin levels in response to OGTT or IVGTT under different experimental conditions in …

Regional Human Resource Development In Asean: An Institutional Theory Perspective, Oleksandr Tkachenko, Oliver S. Crocco, Loi A. Nguyen, Victoria Jonathan

Faculty Publications

With the growing influence of intergovernmental organizations such as the European Union and the Association of Southeast Asian Nations (ASEAN), the scope and complexity of human resource development (HRD) activities have expanded. Informed by an institutional theory perspective, we examined the evolution of HRD as well as HRD-related programs in ASEAN to illuminate the mechanisms and conditions shaping HRD in ASEAN. Our primary sources were archival data from ASEAN from 1967–2021 and relevant publications of international development agencies that feature HRD-related activities in the region. Our analysis suggests that the establishment of an intergovernmental organization (i.e., ASEAN), with its continuing …

Feedback Stabilization And Robustness Analysis Using Bounds On Fundamental Matrices, Frederic Mazenc, Michael Malisoff

Faculty Publications

We prove a new robust stabilization theorem for time-varying systems that have sampled measurements and time-varying disturbances, and we provide new observer designs, using novel bounds for fundamental matrices for systems with disturbances. Our main tools use properties of Metzler matrices and positive systems.

In Search Of Short Gamma-Ray Burst Optical Counterparts With The Zwicky Transient Facility, Tomás Ahumada, Shreya Anand, Michael W. Coughlin, Igor Andreoni, Erik C. Kool, Harsh Kumar, Simeon Reusch, Ana Sagués-Carracedo, Robert Stein, S. Bradley Cenko, Mansi M. Kasliwal, Leo P. Singer, Rachel Dunwoody, Joseph Mangan, Varun Bhalerao, Mattia Bulla, Eric Burns, Matthew J. Graham, David L. Kaplan, Daniel Perley, Mouza Almualla, Joshua S. Bloom, Virginia Cunningham, Kishalay De, Pradip Gatkine, Anna Y.Q. Ho, Viraj Karambelkar, Albert K.H. Kong, Yuhan Yao, G. C. Anupama, Sudhanshu Barway, Shaon Ghosh, Ryosuke Itoh

Faculty Publications

The Fermi Gamma-ray Burst Monitor (GBM) triggers on-board in response to ∼40 short gamma-ray bursts (SGRBs) per year; however, their large localization regions have made the search for optical counterparts a challenging endeavour. We have developed and executed an extensive program with the wide field of view of the Zwicky Transient Facility (ZTF) camera, mounted on the Palomar 48 inch Oschin telescope (P48), to perform target-of-opportunity (ToO) observations on 10 Fermi-GBM SGRBs during 2018 and 2020-2021. Bridging the large sky areas with small field-of-view optical telescopes in order to track the evolution of potential candidates, we look for the elusive …

Passive Laser Power Stabilization Via An Optical Spring, Torrey Cullen, Scott Aronson, Ron Pagano, Marina Trad Nery, Henry Cain, Jonathon Cripe, Garrett D. Cole, Safura Sharifi, Nancy Aggarwal, Benno Willke, Thomas Corbitt

Faculty Publications

Metrology experiments can be limited by the noise produced by the laser involved via small fluctuations in the laser’s power or frequency. Typically, active power stabilization schemes consisting of an in-loop sensor and a feedback control loop are employed. Those schemes are fundamentally limited by shot noise coupling at the in-loop sensor. In this Letter, we propose to use the optical spring effect to passively stabilize the classical power fluctuations of a laser beam. In a proof of principle experiment, we show that the relative power noise of the laser is stabilized from approximately 2 × 10⁻⁵ Hz^{−1 …}

An Assessment Of The Extremes And Impacts Of The February 2021 South-Central U.S. Arctic Outbreak, And How Climate Services Can Help, Rebecca A. Bolinger, Vincent M. Brown, Christopher M. Fuhrmann, Karin L. Gleason, T. Andrew Joyner, Barry D. Keim, Amanda Lewis, John W. Nielsen-Gammon, Crystal J. Stiles, William Tollefson, Hannah E. Attard, Alicia M. Bentley

Faculty Publications

In February 2021, a widespread cold-air outbreak, with two associated winter storm systems, impacted the South-Central United States. After a comprehensive summary of the synoptic setup and a day-by-day analysis of the event, we assess the significance of the storm from a climatological perspective. Concerning winter precipitation, there were isolated instances of record snowfall accumulations. While freezing rain and freezing drizzle both occurred, total freezing precipitation accumulations did not exceed a one-in-50 year event. The duration of the cold was notable — many stations across the region broke records for the highest number of consecutive days below freezing. When analyzing …

The Price Of Decentralization In Cooperative Coverage Problems With Energy-Constrained Agents, Xiangyu Meng, Christos G. Cassandras, Xinmiao Sun, Kaiyuan Xu

Faculty Publications

A multiagent coverage problem is considered with energy-constrained agents, where a charging station is used to replenish an agent's energy as it becomes depleted while performing the coverage task. The objective of this article is to compare the coverage performance between centralized and decentralized approaches. To this end, a centralized coverage control method is developed to switch agents between an optimal coverage formation and an optimal charging formation. We design a controller for agent trajectories that include dwell times at the optimal coverage locations, and charging times at the charging station to maximize a coverage metric over a finite time …

New Efficient Approach To Solve Big Data Systems Using Parallel Gauss–Seidel Algorithms, Shih Yu Chang, Hsiao Chun Wu, Yifan Wang

Faculty Publications

In order to perform big-data analytics, regression involving large matrices is often necessary. In particular, large scale regression problems are encountered when one wishes to extract semantic patterns for knowledge discovery and data mining. When a large matrix can be processed in its factorized form, advantages arise in terms of computation, implementation, and data-compression. In this work, we propose two new parallel iterative algorithms as extensions of the Gauss–Seidel algorithm (GSA) to solve regression problems involving many variables. The convergence study in terms of error-bounds of the proposed iterative algorithms is also performed, and the required computation resources, namely time-and …

A Soft Syntactic Foam Actuator With High Recovery Stress, Actuation Strain, And Energy Output, Siavash Sarrafan, Xiaming Feng, Guoqiang Li

Faculty Publications

Novel syntactic foams were prepared by incorporating three types of glass microbubbles in a crosslinked cis poly(1,4-butadiene) (cPBD) matrix. The as-prepared semi-crystalline polymer-based syntactic foams displayed a clear two-way shape memory effect (2W-SME) with remarkable strain actuation of about 56% expansion when the temperature drops from 60 °C to − 40 °C, and about 40% contraction when the temperature rises from − 40 °C to 60 °C, comparable to most pure two-way shape memory polymers. Compared to the pure cPBD, which was actuated under 0.32 MPa tensile stress, the foams were actuated under a much larger external tensile stress of …

Comparison Of Microstructure And Tensile Behavior Of Hydroxyapatite-Coated Peek Meshes And Cellulose-Based Fabrics And Mats, Armaghan Naderi, Genevieve Palardy

Faculty Publications

Polymeric biomaterials, such as polyether ether ketone (PEEK) and cellulose, have been explored as scaffolds for bone tissue engineering in the past decade. In this study, microstructure and mechanical behavior of uncoated and hydroxyapatite (HA)-coated polymeric meshes, fabrics, and mats were investigated. Commercially available monofilament PEEK meshes, and cellulose fabrics and mats were selected, then coated with a customized low temperature sol–gel method (≤ 150°C). Adhesive HA coating consisting of HA, β-TCP, and CaO with nanorod structure was derived. After HA coating, porosity of substrates (except filter-paper cellulose mats) decreased by up to 43%, indicating effective coating. Both uncoated and …

Tracer And Observationally Derived Constraints On Diapycnal Diffusivities In An Ocean State Estimate, David S. Trossman, Caitlin B. Whalen, Thomas W. N. Haine, Amy F. Waterhouse, An T. Nguyen, Arash Bigdeli, Matthew Mazloff, Patrick Heimbach

Faculty Publications

No abstract provided.

Nature Versus Humans In Coastal Environmental Change: Assessing The Impacts Of Hurricanes Zeta And Ida In The Context Of Beach Nourishment Projects In The Mississippi River Delta, Qiang Yao, Marcelo Cancela Lisboa Cohen, Kam-Biu Liu, Adriana Vivan De Souza, Erika Rodrigues

Faculty Publications

No abstract provided.

Dynamics Of Polymer Melts And Polymer Nanocomposites Studied By Broadband Dielectric Spectroscopy, Mengchun Wu

LSU Doctoral Dissertations

Materials based on polymers and polymeric nanocomposites have properties advantageous for many applications. In many cases, the physical behavior is connected to molecular motion. Polymers are macromolecules in which both fast local motions and slower chain relaxations may contribute to the material properties. Answering fundamental questions on the molecular dynamics is challenging, because of the existence of many different processes and the strong temperature dependence of the processes. An investigation covering a broad window over many orders of magnitude in the time scale is needed. Hence, dielectric spectroscopy is an appropriate tool to enhance fundamental understanding. This dissertation pays special …

Entities: A Field Of Imaginary Games, Thrasyvoulos Ioannis Kalaitzidis

LSU Master's Theses

With this body of work, I am looking for visual symbols that help communicate unuttered meanings through storytelling and stimulate an affectual response to the viewer. This exploration is presented in two different forms: a surreal sculptural installation and a board game. The installation consists of large-scale sculptures made from light and soft materials (polyurethane foam, plastic waste, paper) that are available to move inside the gallery, while the board game is presented as a set of 3D prints with instructions on how the participants can play it. The materials used in the installation suggest a way to transform waste …

Mrs. Florence Mante's Amazing Grace School, Daniel Keith Davis

LSU Master's Theses

Mrs. Florence Mante’s Amazing Grace School is the story of both Mama Florence and the children that she has dedicated her life to. Mrs. Florence Mante is the Ghanaian cofounder of the Amazing Grace Preparatory School. The West African school is committed to developing African leaders and ending the cycles of poverty in the village of Kodiekrom. My thesis focuses on using interview-driven artwork and collaborative storytelling to depict the unique challenges and triumphs of Mama Florence’s life in Ghana. Digital illustrations, a narration from Mama Florence, and music take the viewer on her deeply compelling journey, raising awareness for …