Engineering Commons^™

Microfluidic Pore Model Study On Physical And Geomechanical Factors Influencing Fluid Flow Behavior In Porous Media, Shuang Cao

LSU Doctoral Dissertations

Fluid flow in porous media is a subject of fundamental importance and relevant to numerous engineering applications. The comprehensive description of fluid interaction parameters containing wetting properties, fluid-fluid displacement ratio, and capillary pressure, are inevitably needed. Moreover, the fine-grained sediments’ response to various pore fluids and migration in porous media influences reservoir geomechanical properties and pore clogging is essential to a better understanding of fluids flow behavior.

This dissertation provides a detailed study of physical and geomechanical factors influencing fluids flow behavior in porous media. The two-dimensional micromodel tests have been conducted under a wide selection of fluids flow conditions. …

Development Of Artificial Intelligence Approach To Nowcasting And Forecasting Oyster Norovirus Outbreaks Along The U.S. Gulf Coast, Shima Shamkhali Chenar

LSU Doctoral Dissertations

Oyster norovirus outbreaks pose increasing risks to human health and seafood industry worldwide. This study presents an Artificial Intelligence (AI)-based approach to identifying the primary cause of oyster norovirus outbreaks, nowcasting and forecasting the growing risk of oyster norovirus outbreaks in coastal waters. AI models were developed using Artificial Neural Networks (ANNs) and Genetic Programming (GP) methods and time series of epidemiological and environmental data. Input variable selection techniques, including Random Forests (RF) and Forwards Binary Logistic Regression (FBLR), were used to identify the significant model input variables among six independent environmental predictors including water temperature, solar radiation, gage height, …

Sustained Flow Index: A Stochastic Measure Of Freeway Performance, Siavash Shojaat

LSU Doctoral Dissertations

The capacity of a road addresses its quantitative traffic carrying ability. The estimation of capacity as a parameter to assess traffic flow performance on freeway facilities has received considerable attention in the literature. Research into the traffic operation at high volumes reveals that the capacity of freeways is not a fixed number, but rather a random variable. Thus, in a stochastic approach to freeway capacity of estimation, the capacity is treated as a random variable generated from a population of flow observations, stemmed from a certain distribution function. Since the type of capacity distribution function is generally not known with …

An Enhanced Bridge Weigh-In-Motion Methodology And A Bayesian Framework For Predicting Extreme Traffic Load Effects Of Bridges, Yang Yu

LSU Doctoral Dissertations

In the past few decades, the rapid growth of traffic volume and weight, and the aging of transportation infrastructures have raised serious concerns over transportation safety. Under these circumstances, vehicle overweight enforcement and bridge condition assessment through structural health monitoring (SHM) have become critical to the protection of the safety of the public and transportation infrastructures. The main objectives of this dissertation are to: (1) develop an enhanced bridge weigh-in-motion (BWIM) methodology that can be integrated into the SHM system for overweight enforcement and monitoring traffic loading; (2) present a Bayesian framework to predict the extreme traffic load effects (LEs) …

Development Of A Mode And Destination Type Joint Choice Model For Hurricane Evacuation, Ruijie Bian

LSU Doctoral Dissertations

Since Hurricane Katrina, transit evacuation service has been seen to serve critical needs in affected cities and an increasing number of hurricanes have struck the east coast where more people rely on public transportation to evacuate. Thus, it is important to model mode choice in evacuation for a better estimation of evacuation transit demand. In this study, a joint mode and destination type choice model was estimated based on multiple post-storm behavioral surveys from the northeastern seaboard to the Gulf coast. A Nested Logit model specification was used to estimate this joint choice model. The estimated model showed significant linkage …

Numerical Evaluation Of The Lateral Behavior Of Vertical And Battered Pile Group Foundations Using 3-D Finite Element Modeling, Ahmad Souri

LSU Doctoral Dissertations

The design of pile foundations to resist lateral loads is essential in offshore structures and bridge foundations. The lateral behavior of piles has been studied in the past by experimental investigations coupled with analytical and numerical methods. The problem is complex due to the nonlinearities from soil behavior, gap formation, and pile-soil-pile interaction in pile groups (or the group effect). In this work, the finite element (FE) modeling was used to study the lateral behavior of pile groups. The FE method is robust and allows incorporating the necessary aspects for studying the behavior of pile groups. The nonlinear material behavior …

Optimizing Stabilized Fluorogypsum To Decrease Dissolution Potential In Aquatic Environments For Construction Of Artificial Reefs, Charles Davis Lofton

LSU Doctoral Dissertations

The use of limestone as coastal protection devices and as an oyster cultch material has placed a substantial economic burden on the State of Louisiana. Limestone is not locally available in the State of Louisiana and must be transported from out of state which significantly increases the cost of utilizing the material. Placement of limestone on the unconsolidated soils in coastal Louisiana result in significant losses to sinking of the material due to the density of limestone. Therefore, locally available materials with a lower density compared to limestone are needed to reduce the economic burden of protecting and enhancing coastlines. …

Enhancing The Performance Of Anaerobic Bioreactors For The Biological Degradation Of Volatiles Organic Compounds In Groundwater Using Alternate Electron Acceptors, Leslie Michele Pipkin

LSU Doctoral Dissertations

Engineered anaerobic bioreactors (ABR) constructed from mixed media and sand can biodegrade high concentrations of volatile organic compounds (VOCs). Sustainable treatment of benzene, toluene, ethylbenzene, and xylenes (BTEX), chlorinated ethenes and ethanes were used to investigate the use of engineered ABRs, while also analyzing the system performance of a full-scale ABR system. Experimentations conducted on environmental and biological factors that affect ABR system performance was conducted through serum bottles, columns, and reactor studies.

Column and reactor ABR systems were designed to treat VOCs via biodegradation in groundwater with varying terminal electron acceptors (TEAs). Laboratory-scale column ABRs were constructed to treat …

Diagenesis And Formation Stress In Fracture Conductivity Of Shaly Rocks; Experimental-Modelling Approach In Co2-Rock Interactions, Abiola Olukola Olabode

LSU Doctoral Dissertations

In large scale subsurface injection of carbon dioxide (CO₂) as obtainable in carbon sequestration programs and in environmentally friendly hydraulic fracturing processes (using supercritical CO₂), long term rock-fluid interaction can affect reservoir and seal rocks properties which are essential in monitoring the progress of these operations. The mineralogical components of sedimentary rocks are geochemically active particularly under enormous earth stresses, which generate high pressure and temperature conditions in the subsurface. While geomechanical properties such as rock stiffness, Poisson’s ratio and fracture geometry largely govern fluid flow characteristics in deep fractured formations, the effect of mineralization can …

Rice Hull Bioreactor For Recirculating Aquaculture, Marlon A. Greensword

LSU Doctoral Dissertations

The engineering of floating media biofilters has been optimized over the years. The backwashing process has made them more energy and water efficient. Likewise, moving bed bioreactors (MBBR) are gaining interest and popularity because they are relatively affordable to build. Yet, developing countries’ aquaculture production remains largely excluded from the advances made in recirculating aquaculture systems (RAS). This discrepancy is partially driven by the high costs of media such plastic beads and Kaldnes (KMT) media, commonly used in MBBR.

This dissertation evaluates the usability and profitability of rice hulls (RH), an abundant by-product in many developing nations, as a sinking …

A Decision Making Tool For Incorporating Sustainability Measures In Rigid Pavement Design, Neveen Samy Talaat Soliman

LSU Doctoral Dissertations

One of the most important tools in assessing rigid pavement design sustainability (or environmental impact) is a lifecycle assessment (LCA), which may be applied in any stage of a product’s lifecycle from cradle to grave, such as pavements. Although LCA was the focus of much research and codification by organizations such as the International Organization for Standards and the Society of Environmental Toxicology and Chemistry, limitations exist, such as a) LCA is time consuming; and b) the used data may become outdated, inaccurate, biased, incomplete, and/or expensive to use. These limitations are not a deficiency in LCA as a tool, …

Atmospheric Boundary Layer Processes To Mimic Peak Pressures On Low-Rise Buildings: Cfd Versus Full-Scale And Wind Tunnel Measurements, Hamzeh Gol Zaroudi

LSU Doctoral Dissertations

Realistic prediction of peak wind pressures is indispensable in a safe design of low-rise buildings. For several decades wind tunnel testing was employed to obtain wind loads on buildings and other structures. However, there is still doubt in the wind engineering community regarding the adequacy of wind tunnels to predict accurately full-scale pressures on low-rise buildings and small-size structures. The recommendations of the American Society of Civil Engineers (ASCE) 7-10 standard for external pressure coefficients, for roof components and cladding (C&C) design are also based on published wind tunnel data. Recent field measurements show significant deviation of full-scale pressures from …

Modeling Of Size Effects In Metallic Samples Of Confined Volumes, Mohammadreza Yaghoobi

LSU Doctoral Dissertations

In material science, size effects is described as the variation of material properties as the sample size changes. In this dissertation, the size dependency of the material strength is addressed as size effects. The size effects underlying mechanisms depend on the nature of the considered material. In the case of crystalline metals, size effects in crystalline metals are governed by the dislocations, as the primary deformation mechanism, and their interactions with one another and other defects such as grain boundaries. In this dissertation, the size and strain rate effects of fcc metallic samples of confined volumes are investigated during the …

Vibration Control In Wind Turbines For Multi Hazards, Milad Rezaee

LSU Doctoral Dissertations

The increasing demand for reliable and clean energy with a low running cost, has developed wind energy harvesting industry in a fast rate during the past two decades, and has led to wind farms’ spreading in various regions with larger and taller wind turbines. Consequently, it is more likely that wind turbines are installed or planned to be installed in areas with higher possibility of natural multihazard. Therefore, flexible modern wind turbines are subjected to severe dynamic environmental loads. Generated excessive vibrations in the wind turbine’s structure due to these loads can have detrimental effects on energy production, structural lifecycle …