Concentrations, Sources, And Health Risks Of Particulate Matter In Southeast Us.: Current Status And Future Changes, Fenglin Han

LSU Doctoral Dissertations

Evaluation of long-term air quality trends and prediction of future air quality may help to design and demonstrate effectiveness of control strategies and guide future air quality management. As one of the six criteria air pollutants (CAPs) regulated by the US Environmental Protection Agency (EPA), particulate matter with aerodynamic diameter of 2.5 µm or less (PM_2.5) is of great interests since it has adverse effects on human health, visibility and climate. This study aims to understand the current status and future changes in concentrations, sources, and health risks of PM_2.5 in Southeast US. Firstly, observations were analyzed …

Safety Assessment Of Road Vehicle In Crosswind Considering Driver Behavior, Jiexuan Hu

LSU Doctoral Dissertations

With expansion of the economy, more and more highway networks extend to coastal areas and mountain valley areas. Vehicles will be exposed to strong crosswinds when driven on these highway roads, especially in hurricane season and in winter in these two different topographic areas. Strong crosswinds threaten the safety of transportation infrastructure and passing vehicles in forms of vehicle accidents that usually result in traffic blockage and driver injury, posing negative effects on economic growth. This dissertation aimed to evaluate the vehicle safety when running through crosswinds in consideration of driver behaviors.

Firstly, the aerodynamic characteristics of road vehicles were …

Molecular Dynamics Simulations Of Interaction Of Dna Nucleotides And Lignin Oligomers With Small Molecules And Interfaces, Xinjie Tong

LSU Doctoral Dissertations

Molecular dynamics (MD) simulations of interaction of DNA nucleotides with self-assembled monolayers (SAMs) provide valuable information that is critical to the development of a new DNA sequencing technique. We investigated the interactions and transport characteristics of mononucleotides moving through nanoslits with SAMs-covered surfaces. Our simulations focused on nanoslits in which the walls were composed of three different types of SAMs: methylformyl terminated, methyl terminated, and phenoxy terminated. The results demonstrated that the phenoxy terminated surfaces have the shortest required nanoslits length for nucleotides separation.

Using MD simulations, we also investigated the interaction of mono-lignin and oligo-lignols with lipid bilayers and …

The Effects Of Temperature On The Yields Of Aliphatic And Aromatic Products From The Supercritical Pyrolysis Of 1-Octene, Elizabeth Anne Hurst

LSU Doctoral Dissertations

Prior to their combustion, fuels for future high-speed aircraft are expected to experience supercritical conditions, leading to the production of polycyclic aromatic hydrocarbons (PAH), precursors to solid carbonaceous deposits, via pyrolytic reactions. These solid deposits can clog fuel-transfer lines, causing unsafe aircraft operation. To prevent the formation of fuel-line deposits, it is critical to understand the reaction pathways that lead to PAH formation in the supercritical fuel pyrolysis environment.

To better understand the role of large 1-alkenes in PAH formation, supercritical pyrolysis experiments with model fuel 1-octene, a representative 1-alkene product from supercritical n-alkane pyrolysis, have been performed. The …

Bio-Mechanical Characterization Of Adherent Cell Layers With A Pdms Cantilever, Merrel Truly Holley

LSU Doctoral Dissertations

In the last few decades, the mechanical characteristics of human cells has been linked to many physiological processes and pathological conditions, illustrating the importance as effective biomarkers. Mounting research has shown the mechanical force between cells and the extracellular matrix (ECM) plays a vital role in cellular processes such as tissue homeostasis, wound healing, cancer metastasis, and the progression of various diseases. This mechanical force, or the force that a cell produces on its surroundings, is termed as the cellular traction force (CTF). Precise characterization of the CTF can expand our knowledge of these important cellular processes as well as …

Shortest Path Calculation Using Contraction Hierarchy Graph Algorithms On Nvidia Gpus, Roozbeh Karimi

LSU Doctoral Dissertations

PHAST is to date one of the fastest algorithms for performing single source shortest path (SSSP) queries on road-network graphs. PHAST operates on graphs produced in part using Geisberger's contraction hierarchy (CH) algorithm. Producing these graphs is time consuming, limiting PHAST's usefulness when graphs are not available in advance. CH iteratively assigns scores to nodes, contracts (removes) the highest-scoring node, and adds shortcut edges to preserve distances. Iteration stops when only one node remains. Scoring and contraction rely on a witness path search (WPS) of nearby nodes. Little work has been reported on parallel and especially GPU CH algorithms. This …

Combined Molecular Dynamics And Phase Field Simulation Of Crystal Melt Interfacial Properties And Microstructure Evolution During Rapid Solidification Of Ti-Ni Alloys, Sepideh Kavousi

LSU Doctoral Dissertations

Phase field method has become a popular tool to investigate the microstructure evolution during the solidification. Quantitative predictions using this method is still limited, and in this dissertation, we try to study this problem from different perspectives.

Most of the phase field models consider the solid-liquid interface to be in local equilibrium. Solidification during some manufacturing processes like selective laser melting, and electron beam additive manufacturing is rapid and far from equilibrium which can result in supersaturated solid solutions, segregation-free crystals, or metastable phases. Before obtaining any conclusions from the phase field simulations, we must know the answer for “which …

On I/O Performance And Cost Efficiency Of Cloud Storage: A Client's Perspective, Binbing Hou

LSU Doctoral Dissertations

Cloud storage has gained increasing popularity in the past few years. In cloud storage, data are stored in the service provider’s data centers; users access data via the network and pay the fees based on the service usage. For such a new storage model, our prior wisdom and optimization schemes on conventional storage may not remain valid nor applicable to the emerging cloud storage.

In this dissertation, we focus on understanding and optimizing the I/O performance and cost efficiency of cloud storage from a client’s perspective. We first conduct a comprehensive study to gain insight into the I/O performance behaviors …

Factors Influencing Retirement Decision Making For Louisiana State Government Employees, Osama A. Amous

LSU Doctoral Dissertations

ABSTRACT

Public pension members continually face factors affecting their decision to retire in the changing American society. Workers are living longer and need more medical care with better retirement benefits. For Louisiana public employees specifically, no prior studies have examined the factors affecting workers’ decision to retire nor evaluated the factors impacting workers’ decision.

This multiphase study aimed to identify factors and evaluate the decision-making process that enables Louisianans to retire happily and satisfied with a guaranteed income, and to examine millennials’ decision-making process. In the initial phase, ten active and retired male and female participants answered questions in-person, leading …

Unidirectional And Nonreciprocal Nanophotonic Devices Based On Graphene And Magneto-Optical Materials, Vahid Foroughi Nezhad

LSU Doctoral Dissertations

In this dissertation, we first introduce compact tunable spatial mode converters for graphene parallel plate (GPP) waveguides. The converters are reciprocal and based on spatial modulation of graphene’s conductivity. The wavelength of operation of the mode converters is tunable in the mid-infrared wavelength range by adjusting the chemical potential of a strip on one of the graphene layers of the GPP waveguides. We also introduce optical diodes for GPP waveguides based on a spatial mode converter and a coupler, which consists of a single layer of graphene placed in the middle between the two plates of two GPP waveguides. \par …

Relating Individual Characteristics And Task Complexity To Performance Effectiveness In Individual And Collaborative Problem Solving, Kaveh Sheikhrezaei

LSU Doctoral Dissertations

The objective of this research is to examine the variables that influence performance effectiveness on individual and collaborative problem solving. The last few years have seen renewed interest in how team member personal characteristics and team composition characteristics impact team effectiveness.

Even with a growing quantity of organizations performing jobs by using groups, little is understood how people included in a team impact intragroup interaction and results. Most research investigates group’s performance based on a single characteristic which causes much confusion and contradictory results of the variables that impact overall group performance. Most research typically does not analyze the composition …

Exploring Occupant Behavioral Intentions In Immersive Virtual Environment To Enhance The Design And Engineering Of Sustainable Buildings, Sanaz Saeidi

LSU Doctoral Dissertations

Accurately simulating occupant behavior is essential to improve our understanding about the future energy performance of the buildings. To date, most of the information related to the occupancy behaviors has been gathered through field observations and/or performing experiments within the lab environments. Even though these common data collection methods are effective and reliable for the existing buildings, using such data to project occupant behaviors in other contexts is likely to lead to uncertainties. The most significant theoretical achievement of this dissertation was to provide the future building occupants with thermal experience of non-physically existent environments. In this dissertation occupant behavior …

Investigation Of Subsurface Stratigraphy And Groundwater Dynamics In The Mississippi River Delta, An Li

LSU Doctoral Dissertations

The Mississippi River Delta (MRD) is socioeconomically important to the state of Louisiana and the United States. Various types of land-water system data have been collected in the MRD. However, very few efforts have been made to utilize these datasets in modeling regional stratigraphy and groundwater dynamics in the MRD, especially for the upper 50 m of the depth. In this interval of depth, the Mississippi River and surrounding interdistributary bays intensively interact with the groundwater system. The lack of knowledge in regional stratigraphy and groundwater dynamics hinder an understanding of how hydrogeological setting affects processes such as surface-groundwater interaction, …

Effect Of Light Activated Self-Healing Polymers On The Performance Of Asphalt Pavement Containing Recycled Asphalt Materials (Rap/Ras), Sharareh Shirzad

LSU Doctoral Dissertations

A new generation of Ultraviolet (UV) light-induced self-healing polymers was introduced for the asphalt pavement application with the aim to enhance pavements durability while increasing its service life. The developed self-healing polymer was mixed with asphalt binder using two different methods, passive and reactive. For the passive method, the cured self-healing polymer was ground to smaller particle size and then it was mixed with asphalt binder using a high shear stirrer and at a high temperature. For the reactive method, self-healing polyurethane pre-polymer was added to the asphalt binder at a lower temperature and lower shear rate compare to the …

Groundwater Management Optimization And Saltwater Intrusion Mitigation Under Uncertainty, Jina Yin

LSU Doctoral Dissertations

Groundwater is valuable to supply fresh water to the public, industries, agriculture, etc. However, excessive pumping has caused groundwater storage degradation, water quality deterioration and saltwater intrusion problems. Reliable groundwater flow and solute transport modeling is needed for sustainable groundwater management and aquifer remediation design. However, challenges exist because of highly complex subsurface environments, computationally intensive groundwater models as well as inevitable uncertainties. The first research goal is to explore conjunctive use of feasible hydraulic control approaches for groundwater management and aquifer remediation. Water budget analysis is conducted to understand how groundwater withdrawals affect water levels. A mixed integer multi-objective …

Systems Approach To Evaluating Mih-Cp (Mobile Integrated Healthcare – Community Paramedicine): A Case Study Of East Baton Rouge Parish (Ebrp) Emergency Medical Services (Ems) Community Paramedicine Program Initiative, Oluwakemi Aiyedun

LSU Doctoral Dissertations

This study applied a holistic method of healthcare program assessment, known as systems approach, to evaluate the efficacy of the East Baton Rouge Parish (EBRP) EMS Community-integrated Health Program (CIHP). The author developed assessment metrics following the Quadruple Aim Framework: IHI (Institute for Healthcare Improvement) Triple Aim + Provider Experience.

Results showed that the CP program in this study delivers high ratings on patient experience and provided a 51% return on investment (ROI) through reduced emergency service utilization, ED visits and inpatient hospital admissions. However, findings did not demonstrate meaningful improvement in patients’ health-related quality of life (HRQoL) and self-efficacy …

Supercritical Co2 Foam Enhanced Oil Recovery: From Mechanistic Model Fit To Lab Experiments To Field-Scale Evaluation, Mohammad Izadi

LSU Doctoral Dissertations

This study investigates how a mechanistic foam modeling approach based on bubble population balance is applied to a series of laboratory experimental data of a supercritical CO₂ foam in reservoir conditions to extract model parameters (topic 1). The model with model parameters determined from the fit is then used to estimate how far fine-textured strong foam can propagate into the reservoir, before turning into coarse-textured weak foam and before being segregated by gravity (topic 2). With the help of mechanistic model, a possible range of gas mobility for supercritical CO₂ foam is calculated and the resulting gas-phase mobility …

Effect Of Surfactant, Oil:Water Ratio And Temperature On The Rheology Of Emulsion-Suspension Complex Fluids: Implications For Oil-Based Drilling Fluids, Gilles Landry Numkam

LSU Doctoral Dissertations

Drilling fluids are non-Newtonian mixtures that play a critical role in the timely and successful completion of oil and gas wells. In the particular case of offshore operations, proper design of drilling fluids is of paramount importance in the constant quest to lower break-even prices. Most downhole problems are directly or in-directly related to the rheological and physical properties of drilling fluids, thereby calling for a better understanding of the underlying changes of these properties with respect to drilling fluid composition and external conditions.

The current stance in the design of drilling fluids involves the selection of components and their …

Multiphase Cfd Modeling In Particle-Laden Flows, Zhizhong Ding

LSU Doctoral Dissertations

Multiphase modeling is prevalent and useful in solving problems involving multiphase interactions such as fluid and solid. Applications conclude but not limited to fluidized bed, hydraulic conveying, and many others. Modeling techniques with multiple scales can provide various states of details with diverse computational resources used. In this dissertation, two CFD multiphase models are used to disclose interaction details in the particulate system. Two-Fluid Model is used to solve pulsed fluidized bed problem and immersed boundary method based direct numerical method is used to solve particle’s behavior in shear flow. Getting a better understanding of these problems to help to …

Performance Study Of Link Slab Continuity In Prestressed Concrete Bridges, Marco Tulio Canales Jr

LSU Doctoral Dissertations

Link slabs in bridges can be a cost-effective solution to increase the service life of bridge structures. The partial continuity condition in link slab bridges, however can be challenging to quantify. In this work link slab performance is studied by means of a parametric study, a long-term Structural Health Monitoring (SHM) System, and a detailed finite-element model.

The parametric study was conducted using mathematical and a two-dimensional (2D) finite element model. The study considers bridge design factors such as number of spans, span length, span length ratio, girder separation, and temperature settings, in conjunction with the corresponding girder and support …

A Novel Privacy Disclosure Risk Measure And Optimizing Privacy Preserving Data Publishing Techniques, Marmar Orooji

LSU Doctoral Dissertations

A tremendous amount of individual-level data is generated each day, with a wide variety of uses. This data often contains sensitive information about individuals, which can be disclosed by “adversaries”. Even when direct identifiers such as social security numbers are masked, an adversary may be able to recognize an individual's identity for a data record by looking at the values of quasi-identifiers (QID), known as identity disclosure, or can uncover sensitive attributes (SA) about an individual through attribute disclosure. In data privacy field, multiple disclosure risk measures have been proposed. These share two drawbacks: they do not consider identity and …

High Enthalpy Storage Thermoset Network With Giant Stress And Energy Output In Rubbery State And Associated Applications, Jizhou Fan

LSU Doctoral Dissertations

In this study, a new shape memory thermoset network with giant stress and energy output in rubbery state is synthesized and studied firstly since the low output in stress and energy in rubbery state has been a bottleneck for wide-spread applications of thermoset shape memory polymers (SMPs). Traditionally, stress or energy storage in thermoset network is through entropy reduction by mechanical deformation or programming. We here report another mechanism for energy storage, which stores energy primarily through enthalpy increase by stretched bonds during programming. As compared to entropy-driven counterparts, which usually have a stable recovery stress from tenths to several …

Large-Scale Data Analysis And Deep Learning Using Distributed Cyberinfrastructures And High Performance Computing, Richard Dodge Platania

LSU Doctoral Dissertations

Data in many research fields continues to grow in both size and complexity. For instance, recent technological advances have caused an increased throughput in data in various biological-related endeavors, such as DNA sequencing, molecular simulations, and medical imaging. In addition, the variance in the types of data (textual, signal, image, etc.) adds an additional complexity in analyzing the data. As such, there is a need for uniquely developed applications that cater towards the type of data. Several considerations must be made when attempting to create a tool for a particular dataset. First, we must consider the type of algorithm required …

Field Performance And Cost Effectiveness Of Crack Sealing In Flexible And Composite Pavements, Momen Ragab Mousa

LSU Doctoral Dissertations

Surface cracking is one of the major surface distresses in asphalt concrete (AC) pavement, allowing water infiltration through the cracks, causing stripping in asphalt pavement layers, and weakening and deteriorating the base and/or subgrade. Its treatment, therefore, is one of the major activities in pavement preservation for many state DOTs. Among the various treatment methods currently available to preserve AC pavement with existing surface cracking are various forms of crack sealing. Crack sealing is not a common practice to Louisiana highways since the benefit of such treatment appears to be affected by the elevation of the ground water table. Studies …

Neurostimulator With Waveforms Inspired By Nature For Wearable Electro-Acupuncture, Jose Aquiles Parodi Amaya

LSU Doctoral Dissertations

The work presented here has 3 goals: establish the need for novel neurostimulation waveform solutions through a literature review, develop a neurostimulation pulse generator, and verify the operation of the device for neurostimulation applications.

The literature review discusses the importance of stimulation waveforms on the outcomes of neurostimulation, and proposes new directions for neurostimulation research that would help in improving the reproducibility and comparability between studies.

The pulse generator circuit is then described that generates signals inspired by the shape of excitatory or inhibitory post-synaptic potentials (EPSP, IPSP). The circuit analytical equations are presented, and the effects of the circuit …

Graph Information Processing For Artificial Intelligence, Limeng Pu

LSU Doctoral Dissertations

In the last decade, techniques for artificial intelligence (AI) has advanced tremendously, which lead to solutions to many problems that have long-troubled us. Such examples include image/video recognition, speech recognition, and 3D scenario recognition. As the tool become more and more powerful, we started to explore data types that have never been handled in an AI fashion. Graph is undoubtedly the first one that comes to mind. Many important real-life data is or can be represented as graphs or networks: social networks, communication networks, protein-protein interaction networks, molecular structures, etc. Yet very little attention has been devoted to the study …

System Identification Based On Errors-In-Variables System Models, Hyundeok Kang

LSU Doctoral Dissertations

We study the identification problem for errors-in-variables (EIV) systems. Such an EIV model assumes that the measurement data at both input and output of the system involve corrupting noises. The least square (LS) algorithm has been widely used in this area. However, it results in biased estimates for the EIV-based system identification. In contrast, the total least squares (TLS) algorithm is unbiased, which is now well-known, and has been effective for estimating the system parameters in the EIV system identification.

In this dissertation, we first show that the TLS algorithm computes the approximate maximum likelihood estimate (MLE) of the system …

Application Of Pressure And Rate Transient Analyses To Stress-Sensitive Multi-Fractured Composite Systems And Compartmentalized Reservoirs, Oscar Mauricio Molina

LSU Doctoral Dissertations

Pressure transient analysis (PTA) is one of the most robust and commonly interpretation tools available for reservoir characterization. Common applications of PTA include estimation of near-wellbore and reservoir properties, detection of reservoir limits and identification of depletion mechanisms. In addition, PTA allows the identification of sealing and leaky faults and the characterization of its properties, such as permeability and transmissibility hence direction of leakage within the fault.

The purpose of this dissertation is to introduce the analytical solution for pressure-transient behavior for three novel reservoir models. First, we develop the analytical model of a multi-fracture horizontal well (MFHW) with pressure-dependent …

Cost Effective, Highly Efficient Wireless Power Transfer Systems For Ev Battery Charging, Amir Masoud Bozorgi

LSU Doctoral Dissertations

The impact of changing inner diameter of wireless power transfer (WPT) coils on coupling coefficient is studied. It is demonstrated that at a certain outer and inner coil diameter, turn space variation has minor effect on the coupling coefficient. Next, two compensation networks, namely primary LCC and secondary LCC, which offer load-independent voltage transfer ratio and zero voltage switching for WPT, are presented. For both compensation networks, the condition for having zero voltage switching operation are derived. In addition, load-independent voltage transfer ratio (VTR) frequencies are obtained and VTR at each frequency is derived. Then, required equations for calculation of …

Developing An Optomechanical Approach For Characterizing Mechanical Properties Of Single Adherent Cells, Ali Mehrnezhad

LSU Doctoral Dissertations

Mechanical properties of a cell reflect its biological and pathological conditions including cellular disorders and fundamental cellular processes such as cell division and differentiation. There have been active research efforts to develop high-throughput platforms to mechanically characterize single cells. Yet, many of these research efforts are focused on suspended cells and use a flow-through configuration. Therefore, adherent cells are detached prior to the characterization, which seriously perturbs the cellular conditions. Also, methods for adherent cells are limited in their throughput.

My study is aimed to fill the technical gap in the field of single cell analysis, which is a high-throughput …