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Extracting Physically Realistic Pore Network Features From Xct Data And Investigating The Impact Of Pore Topology On Flow In Porous Media, Godfrey Mills
LSU Doctoral Dissertations
Synchrotron XCT imaging approaches applied in this study provides crucial information on the impact of image voxel resolution on image based simulation results and the characteristic length scales that can be extracted from XCT image data sets. The methods and results in this work provides a holistic approach in generating reliable and representative porous media flow and transport properties via image processing and pore scale simulations through XCT image data sets of porous media. This study also shows how XCT imaging, coupled with pore topological and morphological measures can be utilized in quantifying the differences, and/or similarities between a 2.5D …
Molecular Simulation Study Of Oil Hydrocarbons, Dispersants And Other Organics In Atmospheric Air/Water Interfaces, Zenghui Zhang
Molecular Simulation Study Of Oil Hydrocarbons, Dispersants And Other Organics In Atmospheric Air/Water Interfaces, Zenghui Zhang
LSU Doctoral Dissertations
The main objective of this dissertation is to study the interfacial properties of organic contaminants, in particular green leaf volatiles (GLVs), oil hydrocarbons [mainly intermediate-volatile organic compounds (IVOCs) and semi-volatile organic compounds (SVOCs)], as well as surfactant species (i.e. DOSS and Span 80) from Corexit dispersants at atmospheric air/water and air/seawater interfaces. All these compounds can significantly contribute to the formation of secondary organic aerosols (SOAs). Furthermore, our simulation work on IVOCs, SVOCs and Corexit surfactants, combining with experiments from the Valsaraj group, suggests that these compounds can be adsorbed on the surface of seawater droplets and aerosolized into the …
Application Of The Variational Fracture Model To Hydraulic Fracturing In Poroelastic Media, Chukwudi Chukwudozie
Application Of The Variational Fracture Model To Hydraulic Fracturing In Poroelastic Media, Chukwudi Chukwudozie
LSU Doctoral Dissertations
Hydraulic fracturing has persisted through the use of simple numerical models to describe fracture geometry and propagation. Field tests provide evidence of interaction and merging of multiple fractures, complex fracture geometry and propagation paths. These complicated behaviors suggest that the simple models are incapable of serving as predictive tools for treatment designs. In addition, other commonly used models are designed without considering poroelastic effects even though a propagating hydraulic fracture induces deformation of the surrounding porous media. A rigorous hydraulic fracturing model capable of reproducing realistic fracture behaviors should couple rock deformation, fracture propagation and fluid flow in the both …
Nano Cost Nano Patterned Template For Surface Enhanced Raman Scattering (Sers) For In-Vitro And In-Vivo Applications, Hsuan-Chao Hou
Nano Cost Nano Patterned Template For Surface Enhanced Raman Scattering (Sers) For In-Vitro And In-Vivo Applications, Hsuan-Chao Hou
LSU Doctoral Dissertations
Raman scattering is a well-known technique for detecting and identifying complex molecular level samples. The weak Raman signals are enormously enhanced in the presence of a nano-patterned metallic surface next to the specimens. This dissertation describes a technique to fabricate a novel, low cost, high sensitive, disposable, and reproducible metallic nanostructure on a transparent substrate for Surface Enhanced Raman Scattering (SERS). Raman signals can be obtained from the specimen surface of opaque specimens. Most importantly, the metallic nanostructure can be bonded on the end of a probe / a needle, and the other end is coupled to a distant spectrometer. …
A Framework To Incorporate A Structural Capacity Indicator Into The State Of Louisiana Pavement Management System, Omar Salaheldin Elbagalati
A Framework To Incorporate A Structural Capacity Indicator Into The State Of Louisiana Pavement Management System, Omar Salaheldin Elbagalati
LSU Doctoral Dissertations
Non-structural factors such as surface distresses and ride quality have been commonly used as the main indicators of in-service pavement conditions. In the last decade, the concept of implementing a structural condition index in Pavement Management System (PMS) to complement functional condition indices has become an important goal for many highway agencies. The Rolling Wheel Deflectometer (RWD) provides the ability to measure pavement deflection while operating at the posted speed limits causing no user delays. The objective of this study was two-fold. First, this study developed a model to predict pavement structural capacity at a length interval of 0.16 km …
Performance Evaluation Of Instrumented Geosynthetics Reinforced Paved Test Sections Built Over Weak Subgrade Using Accelerated Load Testing, Shadi Hanandeh
Performance Evaluation Of Instrumented Geosynthetics Reinforced Paved Test Sections Built Over Weak Subgrade Using Accelerated Load Testing, Shadi Hanandeh
LSU Doctoral Dissertations
Weak soil is a common problem in road construction. Whether it is a temporary access road or a permanent road built over a weak subgrade, a large deformation of the subgrade can lead to deterioration of the paved or unpaved surface. Geosynthetics offer a potentially economical solution for stabilizing roads built over weak soil. Three sets of testing programs were be conducted in this study.The first testing program includes conducting accelerated load testing of full-scale geosynthetic reinforced test lanes using rolling wheel load facility; the second program included conducting laboratory cyclic plate loading test on geosynthetic reinforced test sections constructed …
Development Of A Biosensor System To Detect Bacteria In Food Systems, Luis Alonso Alfaro Sanabria
Development Of A Biosensor System To Detect Bacteria In Food Systems, Luis Alonso Alfaro Sanabria
LSU Doctoral Dissertations
The development of biosensors may assist for the on-site detection of foodborne pathogens. The overall goal of this study was to develop a biosensor system for detecting Listeria innocua (non-pathogenic surrogate bacteria used as a model for pathogenic Listeria monocytogenes) in food systems. The study was divided into three main parts: (1) development of a sample collection and interface system for Listeria innocua from food samples, (2) development of a sample concentration system for the collected bacteria prior detection, and (3) development of a detection system based on a carbon nanotube potentiometric biosensor for a quantitative detection of Listeria innocua. …
Process Monitoring And Data Mining With Chemical Process Historical Databases, Michael Carl Thomas
Process Monitoring And Data Mining With Chemical Process Historical Databases, Michael Carl Thomas
LSU Doctoral Dissertations
Modern chemical plants have distributed control systems (DCS) that handle normal operations and quality control. However, the DCS cannot compensate for fault events such as fouling or equipment failures. When faults occur, human operators must rapidly assess the situation, determine causes, and take corrective action, a challenging task further complicated by the sheer number of sensors. This information overload as well as measurement noise can hide information critical to diagnosing and fixing faults. Process monitoring algorithms can highlight key trends in data and detect faults faster, reducing or even preventing the damage that faults can cause. This research improves tools …
Development Of Single-Well Gas Assisted Gravity Drainage Process For Enhanced Oil Recovery, Bikash Deep Saikia
Development Of Single-Well Gas Assisted Gravity Drainage Process For Enhanced Oil Recovery, Bikash Deep Saikia
LSU Doctoral Dissertations
EOR application in prolific deepwater Gulf of Mexico (DGOM) reservoirs has remained a challenge. Exorbitant well cost (>200M$) precludes having extensive injection patterns and very characteristics of the reservoirs themselves are partly to blame for negligible EOR activity in DGOM. We have been able to develop and demonstrate a novel design in the form of Single Well – Gas Assisted Gravity Drainage (SW-GAGD) process, which is potentially cost effective, at the same time ensuring very high oil recoveries. In this design, a single well acts as an injector as well as a producer, thereby minimizing well cost. The efficacy …
Bridge Rating Based On In-Situ Weigh-In-Motion And Health Monitoring Data, Dana Feng
Bridge Rating Based On In-Situ Weigh-In-Motion And Health Monitoring Data, Dana Feng
LSU Doctoral Dissertations
Parallel to the bridge design methodology changes from the Allowable Stress Design to the Load Factor Design, and then to the reliability based Load and Resistance Factor Design (LRFD), bridge load rating method has also been evolving. Applying the reliability theory to the bridge load rating is more complex than applying to the LRFD since any conservatism can have a significant effect on the assessment of bridge capacity, particularly in load posting and bridge replacement. Although the current Load and Resistant Factor Rating (LRFR) method applying the concept of reliability analyses, it uses very limited site-specific data due to practical …
Strengthening Shear Deficient Thin-Walled Steel Beams By Bonding Pultruded Gfrp Sections, Tuna Ulger
Strengthening Shear Deficient Thin-Walled Steel Beams By Bonding Pultruded Gfrp Sections, Tuna Ulger
LSU Doctoral Dissertations
Rehabilitation and retrofitting methods offer economical and feasible alternatives for upgrading aged and deficient structures. Structural strengthening using Fiber Reinforced Polymer (FRP) composites have been widely investigated by researchers and used in field applications. The main advantage of FRP composites is the superior mechanical properties they offer over traditional structural materials. One novel alternative of these retrofitting methods was developed at Louisiana State University and called “Strengthening-by-Stiffening” (SBS). In SBS, the external strengthening of shear deficient thin-walled steel structures is achieved by bonding pultruded FRP sections to buckling prone web panels. Contrary to the commonly used uniaxial tension resistance of …
Production Of Fermentable Sugars From Energy Cane Bagasse, Saeed Oladi
Production Of Fermentable Sugars From Energy Cane Bagasse, Saeed Oladi
LSU Doctoral Dissertations
Lignocellulosic biomass contains cellulose and hemicellulose which are composed of hexose and pentose sugars. These sugars can be used in the sustainable production of fuels and chemicals. However, the recalcitrant nature of lignocellulosic biomass makes this conversion a challenging process. An effective pretreatment can remove lignin, solubilize the hemicellulose, decrease cellulose crystallinity, and prepare the biomass for enzymatic hydrolysis and conversion into green renewable chemicals. The research study presented in this dissertation addressed some of the challenges associated with the conversion of lignocellulosic biomass into green fuels and chemicals. This study was divided into three main goals. The first goal …
Coastal Flood Risk In A Changing Climate Along The Northern Gulf Of Mexico, Matthew Vernon Bilskie
Coastal Flood Risk In A Changing Climate Along The Northern Gulf Of Mexico, Matthew Vernon Bilskie
LSU Doctoral Dissertations
Coastal regions around the world are experiencing increased vulnerability from natural and manmade disasters. It is anticipated that coastal flood risk will increase due to the effects of climate change, and sea level rise (SLR) in particular. A dynamic, physics-based, framework to compute coastal flood inundation maps under various climate change scenarios was developed. The novel modeling system includes not only SLR, but considers future projections of shoreline evolution and primary dune morphology, upland migration of intertidal marsh, and land use land cover change. A present day hurricane storm surge model was generated for the Mississippi, Alabama, and Florida panhandle …
Analysis Of Disruptions In The Gulf Of Mexico Oil And Gas Industry Supply Chain And Related Economic Impacts, Negar Dahitaleghani
Analysis Of Disruptions In The Gulf Of Mexico Oil And Gas Industry Supply Chain And Related Economic Impacts, Negar Dahitaleghani
LSU Doctoral Dissertations
Catastrophic events are human and economic tragedies in collaboration. Oil spills have enormous impacts on the local economy of the area and for the local labor markets. The Deepwater Horizon oil spill was caused by an explosion on semisubmersible drilling rig (Macondo) on April 20, 2010. Another regional disaster, Hurricane Katrina as it ripped over the core of the Gulf of Mexico producing zone, one of the most important oil and gas production region. With Geological complexities, continued of drilling and production in GoM increases the risk of having leak/spill. Therefore, the Econometrics methods, and Modeling to forecast impacts of …
Internal Cooling Using Novel Swirl Enhancement Strategies In A Slot Shaped Single Pass Channel, Del Alan Segura
Internal Cooling Using Novel Swirl Enhancement Strategies In A Slot Shaped Single Pass Channel, Del Alan Segura
LSU Doctoral Dissertations
A series of heat transfer tests using a single pass slot shaped channel utilizing varying configurations of trapezoid shaped turbulence enhancement strip or varying configurations of high velocity jets issuing from side channels are studied. Thermochromatic Liquid Crystal techniques are used to determine local heat transfer coefficients, which are converted to normalized Nusselt values. The results show a marked improvement over traditional heat transfer enhancements used in the mid-span region of first stage turbine blades.
Application Of The Finite Element Method To Solve Coupled Multiphysics Problems For Subsurface Energy Extraction, Milad Ahmadi
Application Of The Finite Element Method To Solve Coupled Multiphysics Problems For Subsurface Energy Extraction, Milad Ahmadi
LSU Doctoral Dissertations
Fractures are a source of extra compliance in the rock mass. Fracture compliance can estimate the fracture roughness and the type of fluid filling the fracture. The focus of this research study in chapter 2 is to illustrate how the compliance ratio of rough fractures can diverge from the compliance ratio of smooth fractures. The imperfect interface of the fracture is modeled with saw-tooth-like structures. The defined saw-tooth-like structures of contact asperities impose an in-plane asymmetry in the shear direction. The compliance ratio of the rough fracture is larger than the compliance ratio of the smooth fracture. Interlocking and riding …
Automated Generation And Visualization Of Initial Construction Schedules From Building Information Models, Yibrah Weldemihret Weldu
Automated Generation And Visualization Of Initial Construction Schedules From Building Information Models, Yibrah Weldemihret Weldu
LSU Doctoral Dissertations
Recent advances in digital technology have had a significant influence on the quality and speed of sharing and communicating project information in the architecture, engineering, and construction (AEC) industry. The process of acquiring the design intent in order to develop and communicate project schedules, as critical components of project delivery, have similarly been benefitting from such progress. With the relatively recent techniques of Building Information Modeling (BIM) and its capability to integrate the facility design with its construction schedule, meaningul strides have been made in improving the information flow and eventually visualizing the final schedule in 4D. However, the need …
Molecular Simulation Studies Of Hydrophobins Near Gas, Oil And Water Interfaces, Yuwu Chen
Molecular Simulation Studies Of Hydrophobins Near Gas, Oil And Water Interfaces, Yuwu Chen
LSU Doctoral Dissertations
This dissertation contains fundamental, classical molecular simulation studies of the properties of hydrophobins (a unique family of surface-active proteins produced by filamentous fungi in soil) near interfaces involving gas, oil, water, organic solvents and polymers. These studies are relevant to possibly using hydrophobins as natural oil dispersants and in processing of polymers. Preliminary studies by the Russo group suggest that these small surface-active proteins can encapsulate oil, gases and polymers in cylindrical structures. We have performed classic molecular dynamics (MD) simulation and potential of mean force (PMF) calculations of a class I hydrophobin EAS using both all-atom and coarse-grained representations. …
Cobalt-Based Catalysts For The Conversion Of Biomass-Derived Syngas To Ethanol And Higher Oxygenates, Zi Wang
Cobalt-Based Catalysts For The Conversion Of Biomass-Derived Syngas To Ethanol And Higher Oxygenates, Zi Wang
LSU Doctoral Dissertations
Higher oxygenates synthesis by catalytic conversion of synthesis gas are the potential approaches to replace fossil fuels and produce chemicals for pharmaceutical manufacture, detergents and polymer industry. Cobalt-based catalysts are the most promising catalysts to replace noble metal catalysts for producing ethanol, acetaldehyde and higher oxygenates via CO hydrogenation. The formation of higher oxygenates requires active sites that can adsorb CO non-dissociatively and insert to the alkyl intermediate. The hydrogenation of the CO-inserted intermediates yields C2 and C2+ oxygenates. The main focus of this study is to investigate the active site for non-dissociative CO adsorption, and the modification of the …
Growth Of Polycyclic Aromatic Hydrocarbons During The Supercritical Pyrolysis Of N-Decane, Subramanian Venkateswaran Kalpathy
Growth Of Polycyclic Aromatic Hydrocarbons During The Supercritical Pyrolysis Of N-Decane, Subramanian Venkateswaran Kalpathy
LSU Doctoral Dissertations
In order to serve a dual role as a propellant and as a coolant, fuels in the pre-combustion environment of future high-speed aircraft will be exposed to temperatures and pressures of up to 700 °C and 130 atm—conditions that are supercritical for jet fuels. Under such conditions, fuel can undergo pyrolytic reactions leading to the formation of polycyclic aromatic hydrocarbons (PAH), which are precursors to fuel-line solid deposits that can hinder safe operation of the aircraft. Therefore, to prevent solid deposit formation, it is extremely important to understand the PAH formation pathways in the supercritical fuel pyrolysis environment. To better …
Conjunctive Management Of Water Resources Under Climate Change Projection Uncertainty, Amir Mani
Conjunctive Management Of Water Resources Under Climate Change Projection Uncertainty, Amir Mani
LSU Doctoral Dissertations
Goal of this study is to investigate the impacts of climate change projection uncertainty on conjunctive use of water resources. To pursue this goal first, a conjunctive-use model is developed for management of groundwater and surface water resources via mixed integer linear fractional programming (MILFP). The conjunctive management model maximizes the ratio of groundwater usage to reservoir water usage. A conditional head constraint is imposed to maintain groundwater sustainability. A transformation approach is introduced to transform the conditional head constraint into a set of mixed integer linear constraints in terms of groundwater head. A supply network is proposed to apply …
Numerical Simulations Of Wind Effects On Wave Nonlinearity And Hurricane-Induced Sediment Transport On Louisiana Coast, Ke Liu
LSU Doctoral Dissertations
The objective of this study is to model wind effects on wave nonlinearity and the sediment suspension, transport and redistribution caused by hurricanes. The following questions are addressed through numerical simulations: (1) How do winds affect wave triad interactions and wave shape in the shallow water? (2) What is the role of hurricanes in coastal landscape evolution? Do they create more erosion or deposition? (3) Where does the observed post-hurricane deposition on coastal wetlands come from? First, wind effects were incorporated into a Boussinesq-type wave model, and evolution equations were derived for triad interactions with winds. Second, a coupled modeling …
Powers And Compensation In Three-Phase Systems With Nonsinusoidal And Asymmetrical Voltages And Currents, Prashanna Dev Bhattarai
Powers And Compensation In Three-Phase Systems With Nonsinusoidal And Asymmetrical Voltages And Currents, Prashanna Dev Bhattarai
LSU Doctoral Dissertations
A contribution to power theory development of three-phase three-wire systems with asymmetrical and nonsinusoidal supply voltages is presented in this dissertation. It includes: • contribution to explanation of power related phenomena • contribution to methods of compensation The power equation of unbalanced Linear Time Invariant (LTI) loads at sinusoidal but asymmetrical voltage is first presented. The different current components of such a load and the phenomenon associated with these current components are described. The load current decomposition is used for the design of reactive balancing compensators for power factor improvement. Next, the current of LTI loads operating at nonsinusoidal asymmetrical …
Numerical Simulation Of Pile Installation And Following Setup Considering Soil Consolidation And Thixotropy, Firouz Rosti
Numerical Simulation Of Pile Installation And Following Setup Considering Soil Consolidation And Thixotropy, Firouz Rosti
LSU Doctoral Dissertations
During pile installation, the stresses and void ratios in the surrounding soils change significantly, creating large displacements, soil disturbance and the development of excess porewater pressures. The disturbed soils, especially fine grain soils, tend to regain their strength over time due to both the consolidation of the excess porewater pressure and thixotropic behavior of soil particles. In this research, the pile installation process and the subsequent consolidation, the thixotropy and load tests for several test piles were modeled using finite element (FE) model. A new elastoplastic constitutive model, which was developed based on the disturbed state concept (DSC) and critical …
Effective 3d Geometric Matching For Data Restoration And Its Forensic Application, Kang Zhang
Effective 3d Geometric Matching For Data Restoration And Its Forensic Application, Kang Zhang
LSU Doctoral Dissertations
3D geometric matching is the technique to detect the similar patterns among multiple objects. It is an important and fundamental problem and can facilitate many tasks in computer graphics and vision, including shape comparison and retrieval, data fusion, scene understanding and object recognition, and data restoration. For example, 3D scans of an object from different angles are matched and stitched together to form the complete geometry. In medical image analysis, the motion of deforming organs is modeled and predicted by matching a series of CT images. This problem is challenging and remains unsolved, especially when the similar patterns are 1) …
Modelling Hydraulic Fracturing Propagation In Heterogeneous Reservoirs Using Cohesive Zone Methods, Miguel Alejandro Gonzalez-Chavez
Modelling Hydraulic Fracturing Propagation In Heterogeneous Reservoirs Using Cohesive Zone Methods, Miguel Alejandro Gonzalez-Chavez
LSU Doctoral Dissertations
The recent success in exploiting low permeability shale reservoirs has heavily relied on hydraulic fracturing to produce hydrocarbons economically in disadvantaged reservoir conditions. Although horizontal drilling significantly increases the contact area between the wellbore and the reservoir, the objective of hydraulic fracturing is set on creating further expanded conductive flow paths into the reservoir. This research uses cohesive zone method to numerically simulate hydraulic fracture propagation in the presence of natural fractures in two- and three-dimensional model. The Cohesive element approach limits fracture propagation to some predefined paths. However, in highly fractured formations since hydraulic fractures are growing through a …
Numerical Modeling Of Wetland Hydrodynamics, Agnimitro Chakrabarti
Numerical Modeling Of Wetland Hydrodynamics, Agnimitro Chakrabarti
LSU Doctoral Dissertations
Wave induced erosion accounts for as much as 26% of landloss in coastal Louisiana. This dissertation work, focuses on answering research questions relevant to the design of two shoreline protection methods (a) vegetated wetlands and (b) nearshore breakwaters. Two types of numerical models are used - the three-dimensional (3D) Navier Stokes Equation for small to medium scale experiments and a depth integrated, fully non-linear Boussinesq model for dispersive waves for larger, field scale studies. The former model provides insights into the 3D hydrodynamics of wave interaction with vegetation canopies and breakwaters, while the latter model focuses on the horizontal two …
On The Degradation Of Lubricating Grease, Asghar Rezasoltani
On The Degradation Of Lubricating Grease, Asghar Rezasoltani
LSU Doctoral Dissertations
A comprehensive literature review on physical and chemical degradation monitoring and life estimation models for lubricating greases is presented in chapter one. Degradation mechanisms for lubricating grease are categorized and described, and an extensive survey of the available empirical and analytical grease life estimation models including degradation monitoring standards and methods are presented. In chapter two, irreversible thermodynamic theory is employed to study the mechanical degradation of lubricating grease. A correlation between the mechanical degradation and entropy generation is established and the results are verified experimentally using a rheometer, a journal bearing test rig, and a modified grease worker machine. …
Design Of Surface Texture For The Enhancement Of Tribological Performance, Cong Shen
Design Of Surface Texture For The Enhancement Of Tribological Performance, Cong Shen
LSU Doctoral Dissertations
Surface texturing is a method of surface modification that fabricates micro patterns on the contacting surfaces to improve the tribological performance in sliding, lubricated system. It is found that the geometric design of textures has a significant influence on the performance of textured surfaces. Some important geometric parameters, such as the area ratio and the depth-over-diameter ratio, have been identified for textures in the form of circular dimples. The current study aims to improve the friction reduction effect of surface texturing by using textures with novel designs. Some new factors considered in the design of textures are: internal structure and …
Mathematical Scaling And Statistical Modeling Of Geopressured Geothermal Reservoirs, Esmail Ansari
Mathematical Scaling And Statistical Modeling Of Geopressured Geothermal Reservoirs, Esmail Ansari
LSU Doctoral Dissertations
The interest for developing geopressured-geothermal reservoirs along the US Gulf Coast is increasing for securing energy needs and reducing global warming. Identifying the most attractive candidate reservoirs for geothermal energy production requires quick and simple models. Analytical models are not always available and simulating each case individually is expensive. The use of scaling and statistical modeling is one approach to translate the output of a simulator into quick models with general applicability at all scales. The developed models can quickly estimate temperature and thermal energy recovery from the geopressured-geothermal reservoirs. These models can screen large databases of reservoirs to select …