Digital Commons Network^™

Study Of Control Schemes For Series Hybrid-Electric Powertrain For Unmanned Aerial Systems, Darren A. Dehesa Jr

LSU Master's Theses

Hybrid-Electric aircraft powertrain modeling for Unmanned Aerial Systems (UAS) is a useful tool for predicting powertrain performance of the UAS aircraft. However, for small UAS, potential gains in range and endurance can depend significantly on the aircraft flight profile and powertrain control logic in addition to the subsequent impact on the performance of powertrain components. Small UAS aircraft utilize small-displacement engines with poor thermal efficiency and, therefore, could benefit from a hybridized powertrain by reducing fuel consumption. This study uses a dynamic simulation of a UAS, representative flight profiles, and powertrain control logic approaches to evaluate the performance of a …

Correlation Analysis Of Precipitation And River Flow With The Injection And Discharge Of The Three Gorges Dam And Reservoir, Lirong Yin

LSU Master's Theses

The Yangtze River has been the primary support of the resources and transportation of China. Its basin covers an area of 1.8 million square kilometers. The Three Gorges Dam and Reservoir on the Yangtze River is one of the world's largest dams. After the dam construction in 1997, the reservoir started injecting the reservoir to a size of over 600 km². The influence caused by the dam and reservoir on the river system has been overwhelming and destructive. The possible influence of this vast water body and the operation to maintain this waterbody's size and water level on …

A Numerical Investigation Of Salinity Variations In The Barataria Estuary, Louisiana In Connection With The Mississippi River And Restoration Activities, Yanda Ou, Z. George Xue, Chunyan Li, Kehui Xu, John R. White, Samuel J. Bentley, Zhengchen Zang

Faculty Publications

© 2020 Elsevier Ltd A three-dimensional numerical model was applied to the Barataria Estuary in the Northern Gulf of Mexico to study its salinity variations as well as the impacts from the Mississippi River discharges and proposed river diversions. Model-observation comparison showed that the model was able to reproduce the hydrodynamic fields on subtidal to seasonal time scales. Salinity in the Barataria Estuary was high in fall and low in summer, with a greater variability in the lower estuary than the upper estuary. While salinity in the upper estuary was controlled by discharges from a local freshwater diversion, salinity in …

Simulating Hydrological Connectivity And Water Age Within A Coastal Deltaic Floodplain Of The Mississippi River Delta, Alexandra Christensen, Robert R. Twilley, Clinton S. Willson, Edward Castañeda-Moya

Faculty Publications

Located at the mouth of large rivers, coastal deltaic floodplains are important ecosystems for trapping sediment and removing excess nitrogen introduced to the river through agricultural and urban runoff. Hydrological connectivity (the percent of river channel water interacting with floodplain wetlands), water age (the time elapsed since water entered the system via the main river channel) and water temperature have strong impacts on the biogeochemical processes controlling the fate of sediment and nutrients at continental margins. A Delft3D hydrodynamic model was used to explore the role of river and tide forcings, hydrogeomorphology, and vegetation roughness on hydrological connectivity, water age, …

The Exemplary Spartacus: Reception, Adaptation, And Reconstruction, Benjamin Franklin Howland

LSU Doctoral Dissertations

My project, “The Exemplary Spartacus: Reception, Adaptation, and Reconstruction,” focusses on various representations of the gladiator Spartacus. I assert that Spartacus has almost exclusively been and continues to be an exemplary figure, with an extensive and connected literary tradition, working as an empty signifier in differing temporalities and localities. I draw specific attention to a core issue in the study of Spartacus, namely, the plethora of modern representations of Spartacus in various genres, and the continuing influence these representations exert through their blurring of the historical figure with local themes and ideologies. Each draw from the same ancient sources, infusing …

Characterizing The Biophysical Properties And Origin Of Extracellular Matrix In The Breast Tumor Microenvironment, Connor T. King

LSU Master's Theses

Tumors derived from breast tissue possess the ability to manipulate and permanently alter their surrounding tissue. Studies demonstrate that tissues surrounding breast tumors have differences in secreted factors as well as extracellular matrix (ECM) deposition and structure. However, some fundamental gaps exist within this paradigm: specifically, what exacerbates this transformation and are these changes maintained between the subtypes of breast tumors? Therefore, a targeted evaluation of the effects of the tumor on the stromal microenvironment in a subtype specific manner will be invaluable. To determine if tumor aggressiveness and subtype differentially regulate the tumor microenvironment, a model must be constructed …

Comparison Of In-Office Psychiatric Encounters With Out-Of-Office Psychiatric Encounters Regarding Efficacy, Presenteeism, And Self-Perceived Stigma Among Adult Recipients Of Psychiatric Treatment For Depression In Louisiana, Lawrence Sullivan Salone

LSU Doctoral Dissertations

The primary purpose of this study was to conduct a clinical trial to compare the provision of psychiatric evaluation and medication interventions in a virtual out of office format (VOO) with the provision of psychiatric evaluation and medication interventions in a virtual in-office psychiatric encounter (VIO) among adults in Louisiana seeking psychiatric services for the treatment of depression. This study was classified as a pretest-posttest control group non-inferiority double-blind experimental design. Each patient took a self-rated instrument at baseline and at week 8. The study tested the two interventions (VOO and VIO) by way of changes in overall function, changes …

On The Stress Concentration At Sharp V-Notches Under Tension, Trent Mattieu Andrus

LSU Master's Theses

Accurately determining stresses at re-entrant corners using finite element analysis (FEA) is challenging due to the high stresses produced at the corner. Indeed, FEA is unable to obtain quantitatively accurate peak stresses at mathematically sharp re-entrant corners with traditional boundary conditions because these stresses are singular. Imposing a local corner radius by rounding the sharp corner to remove the singular result is an appropriate technique for large radii, but as the corner radius tends to zero and the notch is close to being sharp, we expect there are radii that yield quantitatively inaccurate results with traditional FEA. We seek to …

Modulating Mechanical Properties Of Polymer Composites Via Colloidal Particle Reinforcement, Yusheng Guo

LSU Master's Theses

Additive manufacturing allows the rapid process of complex objects with excellent design flexibility. However, the products often exhibit poor mechanical properties when pure polymer is applied as printable material. In this work, we demonstrate that printability of polymer can be dramatically improved when particle filler is added to form reinforced polymer composites. Furthermore, the interaction between filler and polymer matrix leads to the enhancement in mechanical properties of the printed product. The material reinforcement induced by addition of fillers enables the wide application of polymer composites to print structures with unique features. In the printing of silica-reinforced pNIPAM composite, we …

Characterization Of Multifunctional Mwcnt/Pp Nanocomposite Films For Use In Structural Health Monitoring And Disassembly Of Ultrasonically Welded Single Lap Joints, Harry Cj Frederick

LSU Master's Theses

In this study, multi-walled carbon nanotubes (MWCNT) nanocomposites were characterized and used as energy directors (EDs) in ultrasonic welding (USW) to test their viability as embedded sensors for structural health monitoring (SHM) and as heating elements for disassembly of thermoplastic composite joints. Three MWCNT loadings were used in this study to manufacture MWCNT/polypropylene (PP) nanocomposites, 15, 20, and 25 wt% while only one MWCNT loading was used to manufacture MWCNT/Nylon-6 (PA-6) nanocomposites, 15 wt%. The masterbatch pellets were compression molded into 0.06, 0.25, and 0.50 mm thick films for characterization and welding. For the purposes of using these MWCNT nanocomposites …

Indeterminate Sample Sequencing In Virtual Reality, Chase Mitchusson

LSU Doctoral Dissertations

The VR Sequencer is a tool for composing and performing music which takes advantage of spatial configuration of 3-D objects to generate looping sequences. This project combines dice-rolling with omnidirectional playheads and variable terrain to make a sequencer with indeterminate features in Virtual Reality (VR). A comparison of mapping systems for music games and digital instruments demonstrates a middle ground for interactive music making which the VR Sequencer applies. An inspection of current VR works exhibits a disconnect be- tween VR gamers and experimental musicians. In an attempt to give the gaming community access to experimental music making, the VR …

Free People Of Color In West Feliciana Parish, Louisiana, Evelyn Lenora Wilson

LSU Doctoral Dissertations

“Free People of Color in West Feliciana Parish, Louisiana” documents the presence, land ownership, business development, and personal relationships of free people of color in a rural Louisiana parish. Beginning with how free people of color came to be in the parish, it shows an absence of segregation by skin color in home ownership, business relationships, and friendships. Free people of color found themselves accepted in a community that valued their talents and skills and disregarded the color of their skin.

Free people of color bought and sold homes in whatever part of the parish suited them. Most lived surrounded …

Molecular Motions Of Acetonitrile Molecules In The Solvation Shell Of Lithium Ions, Xiaobing Chen, Daniel G. Kuroda

Faculty Publications

© 2020 Author(s). Lithium ion solutions in organic solvents have become ubiquitous because of their use in energy storage technologies. The widespread use of lithium salts has prompted a large scientific interest in elucidating the molecular mechanisms, giving rise to their macroscopic properties. Due to the complexity of these molecular systems, only few studies have been able to unravel the molecular motions and underlying mechanisms of the lithium ion (Li+) solvation shell. Lately, the atomistic motions of these systems have become somewhat available via experiments using ultrafast laser spectroscopies, such as two-dimensional infrared spectroscopy. However, the molecular mechanism behind the …

Experiential Statistics - A Case Study In Favor Of Using Project-Based Learning To Advance Preliminary Statistics Content Knowledge In The Algebra I And Geometry Classroom, Trey Earle

Faculty Publications

Preparing secondary students for college entrance requirements and the expectations of the job market, a market which is actively seeking the employees who are most qualified to take on jobs that require data analysis skills, is becoming increasingly important. Federal, state, and local education administrators and personnel must rewrite many of the general education curricula to incorporate data organization, collection, manipulation, application, and analysis in order to better prepare students for the expectations of college entrance and an ever-changing employment market. From a purely pedagogical standpoint, while traditional educational structure has been commonplace for decades in the United States, projects …

A Phase-Field Approach To Diffusion-Driven Fracture, Friedrich Wilhelm Alexander Dunkel

LSU Doctoral Dissertations

In recent years applied mathematicians have used modern analysis to develop variational phase-field models of fracture based on Griffith's theory. These variational phase-field models of fracture have gained popularity due to their ability to predict the crack path and handle crack nucleation and branching.

In this work, we are interested in coupled problems where a diffusion process drives the crack propagation. We extend the variational phase-field model of fracture to account for diffusion-driving fracture and study the convergence of minimizers using gamma-convergence. We will introduce Newton's method for the constrained optimization problem and present an algorithm to solve the diffusion-driven …

Verbal Response Inhibition And Stuttering In Adults, Shanley Belle Treleaven

LSU Doctoral Dissertations

Many adults who stutter (AWS) attempt to modify or suppress their stuttered speech daily. The ability to effectively suppress motoric behavior after initiation relies on executive functions such as inhibition – specifically verbal inhibition – a challenging task regardless of clinical status. Minimal published data are available about verbal inhibition in non-stuttering adults, and no data are available for AWS. Researchers have reported slower inhibition for AWS during manual tasks, but inconsistent relationships have been found between manual and verbal inhibition. It is often presumed that inhibition differences in AWS, if detected, would be associated with greater difficulties suppressing the …

Developing A Competency Model For Highway Safety Engineers: A Delphi Method, Garrett K. Wheat

LSU Doctoral Dissertations

The primary purpose of this study was to determine the core competencies needed by State DOT Highway Safety Engineers as perceived by Highway Safety experts in the United States. First, a list of competencies was identified. Next, a panel of Highway Safety experts determined the importance of each identified competency for the current year (2020) and for the future (year 2030). Finally, ratings provided by the panel were tested for the presence of consensus.

For this study, the researcher used a Delphi Method as classified by Delbecq, Van de Ven, and Gaustafson (1975). Through this method, a panel of forward-thinking …

From Regulation Of Secondary Metabolites To Increased Virulence Under Sublethal Dosage Of Antibiotics: An Unprecedented Role Of Global Regulator, Mftr, In Burkholderia Thailandensis, Sudarshan Singh Thapa

LSU Doctoral Dissertations

The rise of multi-drug resistant bacteria combined with a decreasing pool of effective antibiotics has placed an increasing need for the development of novel antibiotics. Bacterial natural products or secondary metabolites have been the greatest source for development of novel antibiotics. The genus Burkholderia has recently emerged as a source of promising compounds with antibacterial, antifungal, and anti-cancer activities. Bacterial secondary metabolites provide added advantage to bacteria under stressful environments such as during host infection, evading predators or nutrient deficient conditions. However, genes involved in synthesis of these novel compounds remain silent under normal laboratory growth, creating a hurdle in …

A Single Case Study On The Impact Of Louisiana's Induction Program On High School Beginning Teachers, Lorita Ann Eichelberger

LSU Doctoral Dissertations

Despite the growing body of literature that suggest that beginning teachers need additional support throughout the first couple of years in the profession, there is little research on the impact of induction programs for high school beginning teachers. The purpose of this single case study was to analyze the encounters of three beginning teachers, three mentors, one teacher induction coordinator, and one administrator participating in a teacher induction program in Louisiana and examine the impact of the induction program on teacher development. This qualitative study addressed three research questions: What are the perceptions of beginning teachers about the teacher induction …

Spherically Symmetric Loop Quantum Gravity: Analysis Of Improved Dynamics, Rodolfo Gambini, Javier Olmedo, Jorge Pullin

Faculty Publications

We study the 'improved dynamics' for the treatment of spherically symmetric space-times in loop quantum gravity introduced by Chiou et al in analogy with the one that has been constructed by Ashtekar, Pawlowski and Singh for the homogeneous space-times. In this dynamics the polymerization parameter is a well motivated function of the dynamical variables, reflecting the fact that the quantum of area depends on them. Contrary to the homogeneous case, its implementation does not trigger undesirable physical properties. We identify semiclassical physical states in the quantum theory and derive the corresponding effective semiclassical metrics. We then discuss some of their …

Demonstration Of Dynamic Thermal Compensation For Parametric Instability Suppression In Advanced Ligo, T. Hardwick, V. J. Hamedan, C. Blair, A. C. Green, D. Vander-Hyde

Faculty Publications

Advanced LIGO and other ground-based interferometric gravitational-wave detectors use high laser power to minimize shot noise and suspended optics to reduce seismic noise coupling. This can result in an opto-mechanical coupling which can become unstable and saturate the interferometer control systems. The severity of these parametric instabilities scales with circulating laser power and first hindered LIGO operations in 2014. Static thermal tuning and active electrostatic damping have previously been used to control parametric instabilities at lower powers but are insufficient as power is increased. Here we report the first demonstration of dynamic thermal compensation to avoid parametric instability in an …

A Vaccine Targeting The Rbd Of The S Protein Of Sars-Cov-2 Induces Protective Immunity, Jingyun Yang, Wei Wang, Zimin Chen, Shuaiyao Lu, Fanli Yang, Zhenfei Bi, Linlin Bao, Fei Mo, Xue Li, Yong Huang, Weiqi Hong, Yun Yang, Yuan Zhao, Fei Ye, Sheng Lin, Wei Deng, Hua Chen, Hong Lei, Ziqi Zhang, Min Luo, Hong Gao, Yue Zheng, Yanqiu Gong, Xiaohua Jiang, Yanfeng Xu, Qi Lv, Dan Li, Manni Wang, Fengdi Li, Shunyi Wang, Guanpeng Wang, Pin Yu, Yajin Qu, Li Yang

Division of Basic Science Faculty Publications

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes a respiratory disease called coronavirus disease 2019 (COVID-19), the spread of which has led to a pandemic. An effective preventive vaccine against this virus is urgently needed. As an essential step during infection, SARS-CoV-2 uses the receptor-binding domain (RBD) of the spike protein to engage with the receptor angiotensin-converting enzyme 2 (ACE2) on host cells1,2. Here we show that a recombinant vaccine that comprises residues 319–545 of the RBD of the spike protein induces a potent functional antibody response in immunized mice, rabbits and non-human primates (Macaca mulatta) as early as 7 …

Optimizing The Performance Of Multi-Threaded Linear Algebra Libraries Based On Task Granularity, Shahrzad Shirzad

LSU Doctoral Dissertations

Linear algebra libraries play a very important role in many HPC applications. As larger datasets are created everyday, it also becomes crucial for the multi-threaded linear algebra libraries to utilize the compute resources properly. Moving toward exascale computing, the current programming models would not be able to fully take advantage of the advances in memory hierarchies, computer architectures, and networks. Asynchronous Many-Task(AMT) Runtime systems would be the solution to help the developers to manage the available parallelism. In this Dissertation we propose an adaptive solution to improve the performance of a linear algebra library based on a set of compile-time …

Village Folk: Exploring The Female Black School Counselor's Perception Of Role Confusion And Burnout In Urban Schools In South Louisiana, Christianne Leah Ricard

LSU Doctoral Dissertations

This qualitative study examined female Black school counselor’s perceptions regarding their role when working with students – specifically Black students. More so, this study looked at cultural influence on female Black school counselors’ thoughts and feelings relative to role confusion and burnout. Black Feminist Thought and Maslow’s Hierarchy of Needs served as the theoretical framework that guided this study. In consideration for cultural differences, female Black school counselor’s perceptions can be used to further explain the phenomenon of role confusion and burnout.

More than 10 invitations to participate, interviews were conducted with five female Black school counselors. The research questions …

Multiple Calorific Value Mnnisi Alloy, Shane Stadler, Naushad Ali, Tapas Samanta

College of Science Patents

No abstract provided.

Parallel And Asynchronous Distributed Optimization For Power Systems Operation, Ali Mohammadi

LSU Doctoral Dissertations

Distributed optimization approaches are gaining more attention for solving power systems energy management functions, such as optimal power flow (OPF). Preserving information privacy of autonomous control entities and being more scalable than centralized approaches are two primary reasons for developing distributed algorithms. Moreover, distributed/ decentralized algorithms potentially increase power systems reliability against failures of components or communication links.

In this dissertation, we propose multiple distributed optimization algorithms and convergence performance enhancement techniques to solve the OPF problem. We present a multi-level optimization algorithm, based on analytical target cascading, to formulate and solve a collaborative transmission and distribution OPF problem. This …

The Role Of Sediment-Induced Light Attenuation On Primary Production During Hurricane Gustav (2008), Zhengchen Zang, Z. George Xue, Kehui Xu, Samuel J. Bentley, Qin Chen, Eurico J. D'Sa, Le Zhang, Yanda Ou

Faculty Publications

We introduced a sediment-induced light attenuation algorithm into a biogeochemical model of the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) modeling system. A fully coupled ocean-atmospheric-sediment-biogeochemical simulation was carried out to assess the impact of sediment-induced light attenuation on primary production in the northern Gulf of Mexico during the passage of Hurricane Gustav in 2008. When compared with model results without sediment-induced light attenuation, our new model showed a better agreement with satellite data on both the magnitude of nearshore chlorophyll concentration and the spatial distribution of offshore bloom. When Hurricane Gustav approached, resuspended sediment shifted the inner shelf ecosystem from a nutrient-limited …

The Role Of Sediment-Induced Light Attenuation On Primary Production During Hurricane Gustav (2008), Zhengchen Zang, Z. George Xue, Kehui Xu, Samuel J. Bentley, Qin Chen, Eurico J. D'Sa, Le Zhang, Yanda Ou

Faculty Publications

© Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License. We introduced a sediment-induced light attenuation algorithm into a biogeochemical model of the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) modeling system. A fully coupled ocean-atmospheric- sediment-biogeochemical simulation was carried out to assess the impact of sediment-induced light attenuation on primary production in the northern Gulf of Mexico during the passage of Hurricane Gustav in 2008. When compared with model results without sediment-induced light attenuation, our new model showed a better agreement with satellite data on both the magnitude of nearshore chlorophyll concentration and the spatial distribution of offshore …

Prdm16 Deficiency Leads To Age-Dependent Cardiac Hypertrophy, Adverse Remodeling, Mitochondrial Dysfunction, And Heart Failure, Dasan Mary Cibi, Kathleen Wung Bi-Lin, Shamini Guna Shekeran, Reddemma Sandireddy, Nicole Tee, Anamika Singh, Yajun Wu, Dinesh Kumar Srinivasan, Jean Paul Kovalik, Sujoy Ghosh, Patrick Seale, Manvendra K. Singh

Division of Basic Science Faculty Publications

Hypertrophic cardiomyopathy (HCM) is a well-established risk factor for cardiovascular mortality worldwide. Although hypertrophy is traditionally regarded as an adaptive response to physiological or pathological stress, prolonged hypertrophy can lead to heart failure. Here we demonstrate that Prdm16 is dispensable for cardiac development. However, it is required in the adult heart to preserve mitochondrial function and inhibit hypertrophy with advanced age. Cardiac-specific deletion of Prdm16 results in cardiac hypertrophy, excessive ventricular fibrosis, mitochondrial dysfunction, and impaired metabolic flexibility, leading to heart failure. We demonstrate that Prdm16 and euchromatic histone-lysine N-methyltransferase factors (Ehmts) act together to reduce expression of fetal genes …

Novel Information About The Kinetic Effects Of Equine Shoe Modifications And Kinematic Effects Of Human Digital Devices For Improved Performance In Both Species, Pengju Wang

LSU Master's Theses

Equine shoes are frequently modified to enhance traction for horses that travel on paved surfaces for work, pleasure, or entertainment. Little is known about other common shoe modifications used to enhance traction like calks, tungsten carbide granules, or plastic composition. This information is vital to shoe design to protect the safety and welfare of all service, working, and leisure horses. The objective of the first part of this thesis was to quantify the effect of shoes with and without traction adaptions on kinetic measures in non-lame, light breed horses at a trot. Kinetic data was collected with a force platform …