Engineering Commons^™

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 …

Visualizing The Fate And Distribution Of Pahs In Spartina And Avicennia Tissues From Barataria Basin, La, Kristina Jeannette Sebastian

LSU Master's Theses

During crude oil spill events, vegetation in marsh environments sequester polycyclic aromatic hydrocarbons (PAHs) from the crude oil by partitioning from the air phase through the waxy cuticle on the leaf surface. Recent studies from Macondo oil-impacted marshes have demonstrated that cycling of low molecular weight petrogenic PAHs occurs through the cuticle and other leaf tissue. At present, our understanding of how PAHs travel through the cuticle is coarse and limited by grab samples across the entire leaf, which preventing a full understanding the dynamics of PAH cycling in this environment. Multiphoton (MP) confocal microscopy visualizes the distribution of PAHs …

Sodium-Ion Concentration Flow Cell Stacks For Salinity Gradient Energy Recovery: Power Generation Of Series And Parallel Configurations, Elizabeth Whiddon

LSU Master's Theses

Salinity gradient (SG) energy is a renewable and clean energy resource that exists worldwide from the change in Gibbs free energy when two solutions with different salinities are mixed. More recently, concentration flow cells (CFCs) have been introduced as a new technology for SG energy recovery with the highest reported power density output to date, as a result of the utilization of both the electrode potential and Donnan potential. In this study, multiple CFCs were connected to form a consecutive number of stacks, and systematic analysis was conducted to investigate the influence of both parallel and series electrical wire connections …

Atmospheric Deposition Of Nitrogen And Sulfur In China: Current Status And Future Changes, Cheng Shi

LSU Master's Theses

Dry and wet deposition of nitrogen (N) and sulfur (S) has detrimental impacts on the health of both human and ecosystems. Intensive human activities are responsible for elevating emissions and deposition of N and S species. Large population and fast industrial development led China to one of the countries with highest acid deposition. The large fluxes of N and S deposition have caused acidification of surface water and soil, which damages plant growth and biodiversity in China. N and S deposition has been investigated using ground-based monitoring networks and satellite-based sensors. The limitation of location of monitoring sites and performance …

Living Shorelines As Alternative Methods Of Shoreline Protection, Hunter Shows

LSU Master's Theses

Louisiana’s marshes and coastal estuaries are losing habitat at an alarming rate. High rates of sea level rise coupled with coastal subsidence are turning once thriving marsh land into open water. The sediment starved Mississippi River Delta is drowning, making families homes, property, and livelihoods increasingly vulnerable every year. Significant funding is being allocated for projects to offset the increasing erosion including but not limited to diversions, marsh creation, ridge restoration, and shoreline protection projects.

Living shorelines, for the sake of this study, can be defined as a form of shoreline protection which helps shoreline stabilization and erosion reduction while …

Assessment And Correction Of Lidar-Derived Dems In The Coastal Marshes Of Louisiana, William M. Lauve

LSU Master's Theses

The onset of airborne light detection and ranging (lidar) has resulted in expansive, precise digital elevation models (DEMs). DEMs are essential for modeling complex systems, such as the coastal land margin of Louisiana. They are used for many applications (e.g. tide, storm surge, and ecological modeling) and by diverse groups (e.g. state and federal agencies, NGOs, and academia). However, in a marsh environment, it is difficult for airborne lidar to produce accurate bare-earth measurements and even accurate elevations are rarely verified by ground truth data. The accuracy of lidar in marshes is limited by the sensor’s resolution …

Concentration Flow Cells For Efficient Salinity Energy Recovery With Carbonized Peat Moss And Molybdenum Disulfide Electrodes, Haihui Zhu

LSU Master's Theses

The globally extractable salinity gradient (SG) energy from the mixing of seawater and river water is estimated to be 3% of worldwide electricity consumption. Here we applied carbonized peat moss (CPM) electrodes and molybdenum disulfide (MoS₂) electrodes to a concentration flow cell that is capable of harvesting SG energy based on the electrode (pseudo-)capacitance together with the Donnan potential. The CPM electrodes were made from the visually inexhaustible peat moss by a facile pyrolysis process. With two identical CPM electrodes and a cation-exchange membrane, the cell produced a peak power density of 5.33 W m^-2 and an …

Characterization, Source Apportionment And Health Analysis Of Air Pollutants In India, Hao Guo

LSU Doctoral Dissertations

In recent years, severe pollution events occurred frequently in India, which are of significant concern of the public. However, limited studies have been conducted to understand the formation, sources and health effects of high pollution levels and the information for design of effective control strategies is urgently needed. First, criteria air pollutants data at 10 sites for 2017 in Delhi were analyzed to understand the current pollution status. The results show that annual fine particulate matter (PM_2.5) concentrations exceeded the National Ambient Air Quality Standards (NAAQS), India of 60 µg/m³ at all sites. Source-oriented versions of the …

Low-Density Static Granular Media Filter Bed Turbidity Removal Model, Matthew Louque

LSU Master's Theses

The scattering of light within a fluid, referred to as its turbidity, was investigated against the presence of suspended solids. A linear regression analysis was conduced against turbidity and the total count, combined surface area, and combined volume of the suspended particles for various surface water sources (lakes, rivers, indoor aquaculture systems). It was found that the total combined surface area of suspended particles had the best linear correlation to turbidity, with an adjusted R² of 81.79%. This correlation was integrated with a current theoretical model for predicting solids removal across a granular bed to yield an Integrated Turbidity …

Modeling Of Leakage Through Fault-Zone Structures In Co2 Geological Storage, Dayna Rodriguez Zambrano

LSU Master's Theses

Faults intersecting target geological CO₂ storage zones have important implications for storage integrity. Potential leakage pathways due to fluid over-pressurization are investigated in this project to ensure long-term containment of injected CO₂. Numerical flow simulations coupled with a geomechanical module are presented in this work with the purpose of determining the extent of CO₂ up-fault migration, the driving mechanisms of leakage and the corresponding response of quantified pore pressure and stress variations.

This study uses dual-continuum models performed by using CMG (2017) to correctly account of flow through fractures in a fault damage zone. Numerical simulations …

An Airlifted Tidal Mesocosm For Oil Degradation Studies, Daniel Christopher Alt

LSU Doctoral Dissertations

Mesocosms were constructed to allow scientists to isolate variables in a microtidal marsh environment, mimicking the natural conditions found in Terrebonne Bay. The control offered by these mesocosms is given by a process control system that takes user inputs and automates water movement. Twelve mesocosms were constructed, each holding 4.02 m³ (142 ft³) of marsh soil and 3.88 m³ (137 ft³) of water to give 3 experimental levels and a control, all in triplicate.

Each mesocosms that was constructed contained marsh plants in soil plugs 9 feet in diameter and 3 feet deep. These …