Digital Commons Network^™

Costs And Benefits Of Flood Mitigation In Louisiana, Arash Taghi Nezhad Bilandi

LSU Doctoral Dissertations

Assessing the costs and benefits of hazard mitigation efforts is an essential component of disaster management, planning, and resilience assessment. These calculations are particularly important in locations vulnerable to multiple hazards with high frequencies, such as coastal Louisiana. This study aims to provide an improved understanding of the costs and benefits of flood mitigation efforts in Louisiana funded by federal government grants between 2005 and 2015. Project data provided by the Governor’s Office of Homeland Security and Emergency Preparedness (GOHSEP) were summarized and missing values were imputed using robust statistical approaches. Elevation project cost was investigated for prediction by statistical …

Temperature Transient Analysis For Reservoir Characterization, Yilin Mao

LSU Doctoral Dissertations

Recent developments in downhole temperature measurements open new alternatives contributing to reservoir characterization. In this dissertation, novel forward and inverse models to analyze production- and injection-induced temperature signals are developed for conventional and unconventional reservoir applications. Important limitations of the proposed models are addressed by accounting for fluid property variations and complex production strategies.

Forward modeling approaches involve making relevant assumptions that allow rigorous analytical solutions to be constructed using Laplace transform, Method of Characteristics, and control volume analysis. Our results of the analytical models are benchmarked with those from commercial numerical simulation software. Multiple possible scenarios of conventional reservoirs …

Preparation Of Cellulose Nanofibers From Bamboo Using Microwave Liquefaction, Jiulong Xie

LSU Doctoral Dissertations

Cellulose nanofibers isolated from renewable lignocellulosic biomass are considered highly promising fillers in preparing sustainable composite materials. Although previous technologies on the production of cellulose nanofibers were encouraging, drawbacks such as chemical reagent, high energy consumption, time-consumption, and equipment degradation have limited these techniques for practical applications. In this work, bamboo particles were subjected to microwave liquefaction process and the liquefied bamboo residues were characterized to have a better understanding of the liquefaction behaviors of bamboo. Then, the microwave liquefaction process was optimized for the production of cellulose raw materials and the isolation of cellulose nanofibers. The lignin fraction fractionated …

An Improved Method To Calculate Gas-Lift Valve Set Pressure And Valve Performance Curves, Khadhr A Kh Altarabulsi

LSU Doctoral Dissertations

The main objective of this work is toimprove the accuracy on calculations of design set pressure and performance curves (sizing equations) for Gas-Lift Valves (GLVs) at high pressure (real conditions). This improved calculation method is demonstrated to have an important effect on well unloading and production operations.

The analysis of the valve design set pressure includes an experimental evaluation of the effect of internal dome volume changes on the design set pressure due to the presence of silicone and thermal effects. The evaluationis carried out for different levels of GLV silicone fill, pressures and temperatures. Silicone fills covered 7.5, 10, …

Novel Design And Synthesis Of Composite Nanomaterials For Lithium And Multivalent Ion Batteries, Wangwang Xu

LSU Doctoral Dissertations

Nowadays, the fast-increasing energy demand for efficient, sustainable and environmentally-friendly energy storage devices remains a significant and challenging issue. Lithium ion batteries (LIBs) have been widely used as commercial energy devices in portable electronics and also shown great promise in upcoming large-scale applications due to their advantages of environmental safety, efficiency in energy delivering and light weight. However, due to their limited capacity, energy densities and cycle ability, LIBs still need further improvement to expand their applications to a larger field, especially electric vehicle (EVs) and hybrid electric vehicles (HEVs), in which energy storage devices with large capacity and high …

Unpacking The Double Bind: Exploring How The Intersection Of Race And Gender Shape The Undergraduate Experiences Of African American Women In Engineering, Anissa Guerin

LSU Doctoral Dissertations

This three-part qualitative study explored the factors that contribute to the success of African American female students’ persistence in engineering majors. This study also addressed obstacles African American female students face and overcome to persist in engineering majors. Examining African American women in engineering who persist would be an effective method to provide academic support and increase participation amongst this underrepresented group. In addition to exploring the challenges and barriers faced by African American women, this study also acknowledged the skills, perspectives and resources African American women bring to engineering and engineering education. Highlighting their distinctive contributions and attributes would …

Development Of Polymer-Based In-Plane Nanopore For Dna Sequencing, Zheng Jia

LSU Doctoral Dissertations

Mechanically robust solid-state nanopores have the potential to be the next generation DNA sensing platforms. However, mass production and limited base-calling accuracy are the hurdles for solid-state nanopore based DNA sensing. In order to solve these problems, a polymer dual-nanopore device fabricated via high throughput nanoimprint lithography (NIL) was proposed to sequence DNA by time-of-flight (ToF) measurement. As a proof of concept, this study presents mononucleotides discrimination via ToF measurement using polymer in-plane dual-nanopore device.

First, fabrication of polymer in-plane nanopore with controllable dimensions was studied in consideration of experimental conditions and materials selection. Then, surface charge density effect on …

First-Principles Study On The Catalytic Role Of Cerium Dioxide In The Conversion Of Organic Compounds, Chuanlin Zhao

LSU Doctoral Dissertations

Ceria is an earth-abundant material that has been widely used in heterogeneous catalysis, environmental catalysis, and energy applications thanks for its ability to readily convert between different oxidation states. The objective of this study is to theoretically elucidate the reaction mechanisms for the conversion of model organic compounds on ceria, in order to gain insights for the design of cost-effective and selective ceria-based catalysts. Acetaldehyde, acetic acid, and para-nitrophenyl phosphate monoester were selected as the model compounds to probe ceria surfaces. Density functional theory calculations can provide accurate predictions of adsorption and reaction energetics, which can be used to …

Large Eddy Simulations Of Vertical Jets In Crossflow, Pranaya Pokharel

LSU Doctoral Dissertations

Jets in crossflow (JICF) have applications ranging from oil spill to film cooling of turbine blades. Hence, an understanding of the flow physics is important. The majority of the research has been conducted for low velocity ratios between jet and crossflow with round jets. JICF is demonstrated to behave differently for high velocity ratios and different jet shapes. Circular and rectangular jets are commonly used in aircraft applications. Current study focuses on high velocity ratio JICF issuing from both circular and rectangular exit.

For simulating JICF, an in house code “Chem3D” is used with Large Eddy Simulation (LES) to model …

Reinforcement Learning In Robotic Task Domains With Deictic Descriptor Representation, Harry Paul Moore

LSU Doctoral Dissertations

In the field of reinforcement learning, robot task learning in a specific environment with a Markov decision process backdrop has seen much success. But, extending these results to learning a task for an environment domain has not been as fruitful, even for advanced methodologies such as relational reinforcement learning. In our research into robot learning in environment domains, we utilize a form of deictic representation for the robot’s description of the task environment. However, the non-Markovian nature of the deictic representation leads to perceptual aliasing and conflicting actions, invalidating standard reinforcement learning algorithms. To circumvent this difficulty, several past research …

Thermal And Mechanical Energy Harvesting Using Lead Sulfide Colloidal Quantum Dots, Taher Ghomian

LSU Doctoral Dissertations

The human body is an abundant source of energy in the form of heat and mechanical movement. The ability to harvest this energy can be useful for supplying low-consumption wearable and implantable devices. Thermoelectric materials are usually used to harvest human body heat for wearable devices; however, thermoelectric generators require temperature gradient across the device to perform appropriately. Since they need to attach to the heat source to absorb the heat, temperature equalization decreases their efficiencies. Moreover, the electrostatic energy harvester, working based on the variable capacitor structure, is the most compatible candidate for harvesting low-frequency-movement of the human body. …

Effective Methods And Tools For Mining App Store Reviews, Nishant Jha

LSU Doctoral Dissertations

Research on mining user reviews in mobile application (app) stores has noticeably advanced in the past few years. The main objective is to extract useful information that app developers can use to build more sustainable apps. In general, existing research on app store mining can be classified into three genres: classification of user feedback into different types of software maintenance requests (e.g., bug reports and feature requests), building practical tools that are readily available for developers to use, and proposing visions for enhanced mobile app stores that integrate multiple sources of user feedback to ensure app survivability. Despite these major …

Crash/Near-Crash: Impact Of Secondary Tasks And Real-Time Detection Of Distracted Driving, Peter Ramzy Zaki Bakhit

LSU Doctoral Dissertations

The main goal of this dissertation is to investigate the problem of distracted driving from two different perspectives. First, the identification of possible sources of distraction and their associated crash/near-crash risk. That can assist government officials toward more informed decision-making process, allowing for optimized allocation of available resources to reduce roadway crashes and improve traffic safety. Second, actively counteracting the distracted driving phenomenon by quantitative evaluation of eye glance patterns.

This dissertation research consists of two different parts. The first part provides an in-depth analysis for the increased crash/near-crash risk associated with different secondary task activities using the largest real-world …

Machine Learning Tools For Optimization Of Fuel Consumption At Signalized Intersections In Connected/Automated Vehicles Environment, Saleh Ragab Mousa

LSU Doctoral Dissertations

Researchers continue to seek numerous techniques for making the transportation sector more sustainable in terms of fuel consumption and greenhouse gas emissions. Among the most effective techniques is Eco-driving at signalized intersections. Eco-driving is a complex control problem where drivers approaching the intersections are guided, over a period of time, to optimize fuel consumption. Eco-driving control systems reduce fuel consumption by optimizing vehicle trajectories near signalized intersections based on information of the SpaT (Signal Phase and Timing). Developing Eco-driving applications for semi-actuated signals, unlike pre-timed, is more challenging due to variations in cycle length resulting from fluctuations in traffic demand. …

Bipartite Quantum Interactions: Entangling And Information Processing Abilities, Siddhartha Das

LSU Doctoral Dissertations

The aim of this thesis is to advance the theory behind quantum information processing tasks, by deriving fundamental limits on bipartite quantum interactions and dynamics. A bipartite quantum interaction corresponds to an underlying Hamiltonian that governs the physical transformation of a two-body open quantum system. Under such an interaction, the physical transformation of a bipartite quantum system is considered in the presence of a bath, which may be inaccessible to an observer. The goal is to determine entangling abilities of such arbitrary bipartite quantum interactions. Doing so provides fundamental limitations on information processing tasks, including entanglement distillation and secret key …

Economic Approaches And Market Structures For Temporal-Spatial Spectrum Sharing, Feixiang Zhang

LSU Doctoral Dissertations

In wireless communication systems, economic approaches can be applied to spectrum sharing and enhance spectrum utilization.

In this research, we develop a model where geographic information, including licensed areas of primary users (PUs) and locations of secondary users (SUs), plays an important role in the spectrum sharing system. We consider a multi-price policy and the pricing power of noncooperative PUs in multiple geographic areas. Meanwhile, the value assessment of a channel is price-related and the demand from the SUs is price-elastic. By applying an evolutionary procedure, we prove the existence and uniqueness of the optimal payoff for each PU selling …

Chemically Modified Cellulosic Materials As Multi-Functional Agents In Polymer Composites, Jinlong Zhang

LSU Doctoral Dissertations

Comparative flame retardancy of micro wood fiber plastic composites (WPCs) with fire retardants (1,2-bis(pentabromophenyl) ethane, metal hydroxides and nanoclay) was studied. The fire additives (1,2-bis(pentabromophenyl) ethane as well as magnesium hydroxide) obviously enhanced the fire retarding properties of WPCs. Especially, 1,2-bis(pentabromophenyl) ethane significantly reduced the total heat release as well as heat release rate. In addition, a synergistic effect of 1,2-bis(pentabromophenyl) and nanoclay was achieved for the enhanced fire retarding performance of WPCs.

A copolymer of cellulose nanocrystals (CNCs) and poly(N-vinylcaprolactam) (PVCL) (PVCL-g-CNCs) for use as thermally-responsive polymers with low critical solution temperatures (LCSTs) was synthesized via atom transfer radical …

Field Instrumentations And Numerical Analysis Of Geosynthetic Reinforced Soil – Integrated Bridge System (Grs-Ibs), Allam Ardah

LSU Doctoral Dissertations

Geosynthetic reinforced soil (GRS) is a special soil with geosynthetic fabric closely stacked in layers as soil stabilization and considered an alternative design method to the conventional bridge support technology. In this research study, a field case study of Maree Michel bridge, which is located in Route LA 91 Vermilion Parish in Louisiana, was instrumented with six different types of instrumentations to monitor the performance of GRS-IBS bridge abutment and to develop 2D and 3D finite element models. The instrumentations include Shape Acceleration Array (SAA), earth pressure cells, strain gauges, piezometers, and thermocouples. Additionally, surveying was conducted at the bridge …

Techniques Of Energy-Efficient Vlsi Chip Design For High-Performance Computing, Zhou Zhao

LSU Doctoral Dissertations

How to implement quality computing with the limited power budget is the key factor to move very large scale integration (VLSI) chip design forward. This work introduces various techniques of low power VLSI design used for state of art computing. From the viewpoint of power supply, conventional in-chip voltage regulators based on analog blocks bring the large overhead of both power and area to computational chips. Motivated by this, a digital based switchable pin method to dynamically regulate power at low circuit cost has been proposed to make computing to be executed with a stable voltage supply. For one of …

Engineering Metal-Ligand Interface For Selective Electrochemical Carbon Dioxide Reduction, Yuxin Fang

LSU Doctoral Dissertations

Unsustainable exploitation of fossil fuel and its massive greenhouse gas emission necessitates the development in alternative energy sources. Chemical fuels (CH₃OH or C₂H₅OH) outperform other choices, such as batteries for their high energy densities, which is key to portability. Electrochemical reduction of CO₂is capable of producing a wide range of valuable fuels (Syngas, formic acid, methane and methanol, etc.). Converting CO₂into carbon-based fuels further closes the carbon neutral cycle, which contributes to the effort in reducing global CO₂emission. Integration of organic ligands with transition metals shows great potential …

Spectrum- And Energy-Efficient Radio Resource Allocation For Wireless Communications, Shengjie Guo

LSU Doctoral Dissertations

Wireless communications has been evolved significantly over the last decade. During this period, higher quality of service (QoS) requirements have been proposed to support various services. In addition, due to the increasing number of wireless devices and transmission, the energy consumption of the wireless networks becomes a burden. Therefore, the energy efficiency is considered as important as spectrum efficiency for future wireless communications networks, and spectrum and energy efficiency have become essential research topics in wireless communications. Moreover, due to the exploding of number mobile devices, the limited radio resources have become more and more scarce. With large numbers of …

Investigation Of Flow Mechanisms In Gas-Assisted Gravity Drainage Process, Iskandar Dzulkarnain

LSU Doctoral Dissertations

In this study we investigate displacement mechanism for oil recovered using Gas- Assisted Gravity Drainage (GAGD) method. For a typical oil recovery under gravity drainage, the recovery profile can be characterized by an initial bulk flow which occurs rapidly and a later film flow that extends for a longer duration. It is the latter period where film spreading, the ability of oil to spread above water in the presence of gas, is identified as the displacement mechanism responsible for recovering the remaining oil in gravity drainage process. Literature survey indicates that mathematical models for gravity drainage do not account for …

Coupled Thermo Mechanical Modeling Of Friction Stir Welding And Fatigue Life Improvement Of Friction Stir Welding Structures, Saad Bin Aziz

LSU Doctoral Dissertations

Friction- stir- welding (FSW) is comparatively a new welding process invented by The Welding Institute in 1991. Since no melting or fusion occurs during the welding process, FSW is free of high heat input and solidification defects. Two main objectives have been set forth in this work. The first object of this thesis is to develop thermomechanical models based on experimental knowledge and understanding the FSW process at a fundamental level. The quality of friction-stir-welding (FSW) joints depends on many critical weld process parameters. The main challenge for the FSW is in the selection of these critical process parameters that …

Investigation Of Flow Mechanisms In Gas-Assisted Gravity Drainage Process, Iskandar Dzulkarnain

LSU Doctoral Dissertations

In this study we investigate displacement mechanism for oil recovered using Gas- Assisted Gravity Drainage (GAGD) method. For a typical oil recovery under gravity drainage, the recovery profile can be characterized by an initial bulk flow which occurs rapidly and a later film flow that extends for a longer duration. It is the latter period where film spreading, the ability of oil to spread above water in the presence of gas, is identified as the displacement mechanism responsible for recovering the remaining oil in gravity drainage process. Literature survey indicates that mathematical models for gravity drainage do not account for …

Development Of Self-Healing Mechanisms For Asphalt Pavements, Max Abelardo Aguirre Deras

LSU Doctoral Dissertations

Self-healing mechanisms, such as microcapsules or hollow-fibers, filled with an asphalt rejuvenator present an emerging technology that would enhance an asphalt mixture’s resistance to cracking damage caused by vehicular and environmental loading. The objectives of this study were to: (a) Evaluate the effects of asphalt rejuvenators on hot-mix asphalt mixtures in order to test its effects on the fundamental engineering properties of the mixtures at high and intermediate temperatures; (b) Develop a synthesis procedure for production of microcapsules and hollow-fibers containing an asphalt rejuvenator; (c) Evaluate the self-healing efficiency of double-walled microcapsules and hollow-fibers filled with an asphalt rejuvenator, through …

Direct Quantification Of Deubiquitinating Enzyme Activity In Single Intact Cells, Nora Safabakhsh

LSU Doctoral Dissertations

Challenges in drug efficacy occur during the treatment of most types of cancer due to the heterogeneity of the tumor microenvironment. This has led to the development of personalized medicine. Due to the clinical success of the proteasome inhibitors Bortezomib and Carfilzomib in treatment of multiple myeloma, interest has shifted towards molecularly-targeted chemotherapeutics for ubiquitin-proteasome system (UPS). Deubiquitinating enzymes (DUBs) are an essential part of this pathway which have been found to promote Bortezomib resistance in multiple myeloma patients. Unfortunately, there is a lack of specific, high throughput biochemical assays to characterize DUB activity in patient samples before and after …

Applications Of Computational Models On Studying Particulate Systems, Jielin Yu

LSU Doctoral Dissertations

Particulate systems have been widely studied because of its various phenomena and tight relationship with industry applications. In this dissertation, two types of computational models have been adopted to study two problems with different particulate systems: granular self-organization inside a cylinder driven by an orbital-shaker and the optimal design of bypass line for an industrial-scale 8‑leg polyolefin loop reactor.

In the first study, behavior of both single particle and multiple particles in a rotating cylinder has been modeled by discrete element method (DEM) to understand the mechanism of granular self-organization. Sets of studies have then been performed to study the …

Electrocatalytic Properties Of Ni-Fe Basedalloys Toward Oxygen Evolution Reaction, Xiaodan Cui

LSU Doctoral Dissertations

In this dissertation, laser-based manufacturing was applied to develop NiFe-based alloys, with focus on their electrochemical characteristics toward oxygen evolution reaction during water electrocatalysis. The targeted electrocatalysts were designed by combining catalysis principles of absorption energy, electronic effect and geometry effect. Firstly, a one-step laser-based manufacturing method was applied to prepare a thin layer of NiFe-based electrodes with varied Ni to Fe ratios to replace high-cost noble metals as the electrocatalyst for oxygen evolution reaction (OER). Since each Ni has 0.6 d-vacancy and each Fe atom has 2.2 d-vacancies. The alloying of Ni-Fe allows electrons flowing from Ni to Fe, …

Automated Merging Control Algorithm: A Cooperative Approach For Connected Automated Vehicles In Platoons, Sogand Karbalaieali

LSU Doctoral Dissertations

Transportation systems are being transformed by advanced vehicular connectivity and automation. Human-driven vehicles are being replaced by Connected Automated Vehicles (CAV). The US Department of Transportation’s (DOT) Intelligent Transportation System Joint Program Office (ITS JPO) promotes automated vehicle research which encourages the development and deployment of automated vehicles by infrastructure-based solutions. Advancements in traffic design and operation can offer solutions to the challenges that CAVs face. An example of these challenges is merging on highways where traffic operation could be enhanced by the use of Vehicle to Infrastructure (V2I) communication between the onramp and the mainline vehicles and roadside units …

Decentralized Optimal Control With Application In Power System, Boyu Wang

LSU Doctoral Dissertations

An output-feedback decentralized optimal controller is proposed for power systems with renewable energy penetration. Renewable energy source is modeled similar to the classical generator model and is equipped with the unified power flow controller (UPFC). The transient performance of power system is considered and stability of the dynamical states are investigated. An offline decentralized optimal controller is designed that utilizes only the local states. The network comprises conventional synchronous generators as well as renewable sources with inverter equipped with UPFC. Subsequently, the optimal decentralized controller is compared to the initial stabilizing controller used to obtain the optimal controller. An online …