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Full-Text Articles in Engineering

Numerical Modeling For Long Term Performance Of Soil-Bentonite Cut-Off Walls In Unsaturated Soil Zone, Sukanta Chakraborty Jan 2009

Numerical Modeling For Long Term Performance Of Soil-Bentonite Cut-Off Walls In Unsaturated Soil Zone, Sukanta Chakraborty

LSU Master's Theses

ABSTRACT The construction practices of containment walls are extremely important in this competitive economic market, but development is limited. Unsaturated zone is an integral part of the geotechnical problems, as it affects on any kind of soils structures. The unsaturated zone plays significant role in many aspects of water flow and contaminant transport, including containment system such as: cut-off walls, infiltration, soil moisture storage, evaporation, plant water uptake, ground water recharge, erosion, and runoff. This research focuses on the hydraulic sustainability and performance of soil-bentonite cutoff walls (Britton et al, 2004) models showing hydraulic behavior of barrier walls. The cutoff …


Dynamic Behavior Of Unsaturated Soils, Prathima Alla Jan 2009

Dynamic Behavior Of Unsaturated Soils, Prathima Alla

LSU Master's Theses

The behavior of unsaturated soils is different from the behavior of saturated soil deposits. Unsaturated soils have more than two phases; the pore water pressure in unsaturated soils is negative. The behavior of unsaturated soil when a dynamic loading such as an earthquake loading is imposed on them, the susceptibility of lab tested soils to liquefaction is investigated in this study. As the phenomenon of liquefaction occurs only in the case of saturated soil deposits, the behavior of unsaturated soil under these conditions is investigated. Sand and silty sand are used in this study, wetting and drying soil water characteristic …


Mechanistic Foam Modeling And Simulations: Gas Injection During Surfactant-Alternating-Gas Processes Using Foam-Catastrophe Theory, Ali Afsharpoor Jan 2009

Mechanistic Foam Modeling And Simulations: Gas Injection During Surfactant-Alternating-Gas Processes Using Foam-Catastrophe Theory, Ali Afsharpoor

LSU Master's Theses

The use of foam for mobility control is a promising means to improve sweep efficiency in subsurface applications such as improved/enhanced oil recovery and aquifer remediation. Foam can be introduced into geological formations by injecting gas and surfactant solutions simultaneously or alternatively. Alternating gas and surfactant solutions, which is often referred to as surfactant-alternating-gas (SAG) process, is known to effectively create fine-textured strong foams due to fluctuation in capillary pressure. Recent studies show that foam rheology in porous media can be characterized by foam-catastrophe theory which exhibits three foam states (weak-foam, strong-foam, and intermediate states) and two strong-foam regimes (high-quality …


Atomistic Simulations Of Lipid Bilayers In The Presence Of Dimethylsulfoxide, Raghava Alapati Jan 2009

Atomistic Simulations Of Lipid Bilayers In The Presence Of Dimethylsulfoxide, Raghava Alapati

LSU Master's Theses

In a typical cryopreservation protocol, the system to be preserved is first equilibrated with chemicals known as cryoprotective agents (CPAs). CPAs have been shown to alleviate cell damage from either the solute effects or the formation of intracellular ice during the subsequent freezing process. Thus, an extensive body of literature reporting the effects of CPAs on cellular systems has been accumulated over the last 50 years; detailing largely experimental interactions between cell systems and chemicals. Recent advances in computational methodology now offer an additional dimension in our ability to understand the molecular interactions between cell membranes, idealized as lipid bilayers …


Fundamental Characterization Of Unbound Base Course Materials Under Cyclic Loading, Aaron Matthew Austin Jan 2009

Fundamental Characterization Of Unbound Base Course Materials Under Cyclic Loading, Aaron Matthew Austin

LSU Master's Theses

ABSTRACT Pavements are a layered system each layer distinguished by different materials as required by traffic and subgrade conditions. A base course is an intermediate layer constructed of high quality stone aggregates: quality based on physical properties such as gradation, hardness, and texture. Although indicative of performance, physical properties do not directly measure performance. This thesis presents the results of a comprehensive experimental testing program that was conducted to examine the behavior of unbound granular base materials under cyclic loading and to evaluate the effect of the stress level and moisture content on strain behavior. Three base materials, namely granite, …


Biocompatible/ Bioresorbable Polymer Based Silver Nanaomaterial Coatng For Chronic Indwelling Medical Devices And Bioscaffolds For Tissue Regrowth, Ammar T. Qureshi Jan 2009

Biocompatible/ Bioresorbable Polymer Based Silver Nanaomaterial Coatng For Chronic Indwelling Medical Devices And Bioscaffolds For Tissue Regrowth, Ammar T. Qureshi

LSU Master's Theses

The objective of this study is to synthesize and characterize antimicrobial, bio-polymer based silver nanomaterials composite coatings, for use in chronic indwelling medical devices, and bioscaffolds. The coatings and bioscaffolds are comprised of novel biomass mediated silver nano particles (SNP) that are biocompatible, highly concentrated, highly pure, cost-effective, polydispersed and compatible with a range of polymer systems applicable for use with existing chronic indwelling medical devices. This thesis is divided into three main chapters. In Chapter 1, detailed review on the need for antimicrobial nanocomposite coatings for chronic indwelling medical devices along with different SNP synthesis and characterization methods is …


Efficiency Of Cellulase Enzyme Immobilized On Magnetic Nanoparticles, Jason Jordan Jan 2009

Efficiency Of Cellulase Enzyme Immobilized On Magnetic Nanoparticles, Jason Jordan

LSU Master's Theses

Advances in enzymatic hydrolysis have developed new methods for conversion of lignocellulosic biomass into fermentable sugars for various applications, mainly ethanol production. The present study involves immobilization of a cellulase enzyme complex on a solid support which can be recovered for subsequent use in multiple reactions. The supports of interest include Fe3O4 nanoparticles (~13 nm) and polystyrene-coated particles containing a Fe3O4 core (1-2 µm). Each support contains amine functional groups based on the surface that allow covalent attachment of enzymes via carbodiimide activation. The nanoparticles were characterized using transmission electron microscopy (TEM) and immobilization was confirmed using Fourier transform infrared …


The Development Of A Pore Pressure And Fracture Gradient Prediction Model For The Ewing Banks 910 Area In The Gulf Of Mexico, Jeffrey Steven Fooshee Jan 2009

The Development Of A Pore Pressure And Fracture Gradient Prediction Model For The Ewing Banks 910 Area In The Gulf Of Mexico, Jeffrey Steven Fooshee

LSU Master's Theses

The purpose of this project is to develop a pore pressure and fracture gradient prediction strategy for the Ewing Banks 910 (EW 910) area. Petrophysical and measured pressure data for eight wells previously drilled in the EW 910 area will be examined and reviewed. This strategy will help design future drilling and completion operations in the aforementioned area. Two pore pressure prediction strategies and one fracture gradient prediction strategy will be reviewed and applied to the available data. The first pore pressure prediction strategy reviewed was developed by W. R. Matthews. This strategy utilizes a geologic age specific overlay which …


Thermal Characterization Of Plain And Carbon Nanotube Reinforced Syntactic Foams, Pratap Chandrashekhara Bhat Jan 2009

Thermal Characterization Of Plain And Carbon Nanotube Reinforced Syntactic Foams, Pratap Chandrashekhara Bhat

LSU Master's Theses

Syntactic foams are composite materials in which the matrix phase is reinforced with hollow particles called microballoons. They possess properties such as low moisture absorption, low thermal conductivity and high damage tolerance because of their compositions. Traditionally, syntactic foams are used for many high strength applications and as insulating materials. But for applications demanding better heat dissipation from syntactic foam, conductive filler materials need to be added while maintaining its property of low density. Carbon nanotubes although extremely conductive, have issues of agglomeration in the matrix. In this research, a new approach to the problem of dispersion of nanotubes was …


Self-Healing Of Fiber Reinforced Polymer Compoistes [Sic], Nebiyu Fikru Jan 2009

Self-Healing Of Fiber Reinforced Polymer Compoistes [Sic], Nebiyu Fikru

LSU Master's Theses

The study of self-healing materials is inspired by biological systems in which damage triggers an autonomous healing response. In recent years, this concept of autonomic healing material, where initiation of repair is integral to the material, is being considered for engineering applications. The concept offers the designer an ability to incorporate secondary functional ability of counteracting service degradation in addition to achieving the primary, usually structural integrity, requirement. Self-healing materials also have the benefit of offering lighter and optimized structures as well as reduced maintenance cost. Previous works on polymer matrix composites have shown that significant fractions of mechanical properties …


Evaluation Of Interwell Connectivity Of Little Creek Field, Mississipii [Sic] From Production Data, Gbemisola Yewande Ogunyomi Jan 2009

Evaluation Of Interwell Connectivity Of Little Creek Field, Mississipii [Sic] From Production Data, Gbemisola Yewande Ogunyomi

LSU Master's Theses

The understanding of geological characteristics and heterogeneity of a reservoir enables better decisions for reservoir development. Statistical methods use universally available injection and production rate data to help evaluate reservoir characteristics and behavior.In this research project, statistical methods typically used to infer communication between injector-producer well pairs in a waterflood reservoir using only production and injection rate data are applied to a CO2 flood. The multivariate linear regression (MLR) technique computes weighting coefficients possibly related to the fraction of the flow in a producer that comes from each of the injectors (Albertoni and Lake, 2002). MLR was applied to the …


On The Effects Of Peripheral Sliding Velocity And Operating Differential Pressure In Rotary O-Ring Seals, Karan Lingerkar Jan 2009

On The Effects Of Peripheral Sliding Velocity And Operating Differential Pressure In Rotary O-Ring Seals, Karan Lingerkar

LSU Master's Theses

An O-ring seal is of paramount importance in hydraulic and pneumatic machinery used in oil and gas drilling processes. O-ring seals are generally employed to contain the environments of working fluids existing on either side of the seal from interacting with each other, to maintain a uniform pressure chamber and to eliminate the environmental contaminants that interact at the rubbing interface. Failure of dynamic O-rings in hydraulic and pneumatic machinery often results in considerable productivity loss to the chemical and petrochemical industries. Therefore, it is highly important to determine the life of an O-ring for these applications under various operating …


A Decision Making Framework For Hurricane Evacuation And Sheltering, Jason Fennell Jan 2009

A Decision Making Framework For Hurricane Evacuation And Sheltering, Jason Fennell

LSU Master's Theses

There are few tools currently available to emergency managers to assist in making decisions about whether to evacuate, shelter locally, or shelter-in-place, and none of these tools explicitly consider risk to life safety. A methodology was developed to provide risk-based guidance for evacuation versus sheltering decision making. The hurricane hazards considered in the developed methodology are high winds, storm surge flooding and waves, and rainfall flooding. Vulnerability of buildings to these hazards and the associated risks to life safety are then determined. These results are compared to the hazards and risks associated with evacuation, particularly for medical special needs populations …


Experimental And Numerical Modeling Of Stresses In Non-Conventional Cross-Sectioned Composite Pipes, Prashanth Ramachandran Jan 2009

Experimental And Numerical Modeling Of Stresses In Non-Conventional Cross-Sectioned Composite Pipes, Prashanth Ramachandran

LSU Master's Theses

Composite materials have been widely used in the ship-building, aerospace and construction industries because of their distinct advantages of low weight, high stiffness, and high strength to weight ratios. These properties are due to the low weight of the epoxy core matrix and high strengths of the glass/carbon fibers. Composite pipes used in various applications are traditionally spherical in cross-section. In this study, non-conventional cross-sectioned composite pipes [i.e. rectangular and triangular cross-sections] have been proposed, fabricated, tested and analyzed because of their ability to be bundled without loss of space. The behaviors of these pipes under an internal pressure test …


Framework For Operability Assessment Of Production Facilities: An Application To A Primary Unit Of A Crude Oil Refinery, Sampath Yela Jan 2009

Framework For Operability Assessment Of Production Facilities: An Application To A Primary Unit Of A Crude Oil Refinery, Sampath Yela

LSU Master's Theses

This work focuses on the development of a methodology for the optimization, control and operability of both existing and new production facilities through an integrated environment of different technologies like process simulation, optimization and control systems. Such an integrated environment not only creates opportunities for op¬erational decision making but also serves as training tool for the novice engineers. It enables them to apply engineering expertise to solve challenges unique to the process industries in a safe and virtual environment and also assist them to get familiarize with the existing control systems and to understand the fundamentals of the plant operation. …


The Effects Of Inorganic Solids And Certain Gases On The Thermal Decomposition Of Catechol, Jerome Apilan Robles Jan 2009

The Effects Of Inorganic Solids And Certain Gases On The Thermal Decomposition Of Catechol, Jerome Apilan Robles

LSU Doctoral Dissertations

In order to investigate the effects of calcium carbonate and iron oxide on the thermal decomposition of solid fuels, we have constructed an isothermal flow reactor to perform experiments on the model compound catechol (ortho-dihydroxybenzene), a phenol-type compound representative of coal, wood and biomass. Calcium carbonate and iron oxide are inorganic components of coal and wood, which have demonstrated catalytic properties in thermal reactions and are commercially used to enhance the conversion of solid fuels. In this study, the effects of the inorganic solids on pyrolysis and combustion are conducted through identification and quantification of the products formed after subjecting …


Integrated Data-Driven Techniques For Environmental Pollution Monitoring, Swathi Pakalapati Jan 2009

Integrated Data-Driven Techniques For Environmental Pollution Monitoring, Swathi Pakalapati

LSU Doctoral Dissertations

The adverse health e_x000B_ffects of tropospheric ozone around urban zones indicate a substantial risk for many segments of the population. This necessitates the short term forecast in order to take evasive action on days conducive to ozone formation. Therefore it is important to study the ozone formation mechanisms and predict the ozone levels in a geographic region. Multivariate statistical techniques provide a very e_x000B_ffective framework for the classifi_x000C_cation and monitoring of systems with multiple variables. Cluster analysis, sequence analysis and hidden Markov models (HMMs) are statistical methods which have been used in a wide range of studies to model the …


Task Scheduling And Placement For Reconfigurable Devices, Mostafa Elbidweihy Jan 2009

Task Scheduling And Placement For Reconfigurable Devices, Mostafa Elbidweihy

LSU Doctoral Dissertations

Partially reconfigurable devices allow the execution of different tasks at the same time, removing tasks when they finish and inserting new tasks when they arrive. This dissertation investigates scheduling and placing real-time tasks (tasks with deadline) on reconfigurable devices. One basic scheduler is the First-Fit scheduler. By allowing the First-Fit scheduler to retry tasks while they can satisfy their deadlines, we found that its performance can be enhanced to be better than other schedulers. We also proposed a placement idea based on partitioning the reconfigurable area into regions of various widths, assigning a task to a region based on its …


Bacterial Characterization Of Louisiana Groundwater Contaminated By Dnapl-Containing Chloroethanes And Other Solvents, Kimberly Bowman Jan 2009

Bacterial Characterization Of Louisiana Groundwater Contaminated By Dnapl-Containing Chloroethanes And Other Solvents, Kimberly Bowman

LSU Doctoral Dissertations

In support of an effort to determine the feasibility of using an in-situ bioremediation strategy for cleanup of groundwater in an area containing chlorinated solvents present as a dense non-aqueous phase liquid (DNAPL), the bacterial population in the groundwater at a Superfund site located near Baton Rouge, Louisiana was characterized. More than 3¡Á107 cells/mL in the groundwater were observed via microscopy. Universal bacterial and ¡°Dehalococcoides¡±-specific 16S rRNA gene libraries were constructed and analyzed. Universal clones grouped into 18 operational taxonomic units (OTUs), as defined by sequence similarity ¡Ý97.0%, which included several as yet undescribed organisms. Multiple unique sequences closely related …


Super Resolution And Dynamic Range Enhancement Of Image Sequences, Lutfi Murat Gevrekci Jan 2009

Super Resolution And Dynamic Range Enhancement Of Image Sequences, Lutfi Murat Gevrekci

LSU Doctoral Dissertations

Camera producers try to increase the spatial resolution of a camera by reducing size of sites on sensor array. However, shot noise causes the signal to noise ratio drop as sensor sites get smaller. This fact motivates resolution enhancement to be performed through software. Super resolution (SR) image reconstruction aims to combine degraded images of a scene in order to form an image which has higher resolution than all observations. There is a demand for high resolution images in biomedical imaging, surveillance, aerial/satellite imaging and high-definition TV (HDTV) technology. Although extensive research has been conducted in SR, attention has not …


Asynchronous Replication Of Metadata Across Multi-Master Servers In Distributed Data Storage Systems, Ismail Akturk Jan 2009

Asynchronous Replication Of Metadata Across Multi-Master Servers In Distributed Data Storage Systems, Ismail Akturk

LSU Master's Theses

In recent years, scientific applications have become increasingly data intensive. The increase in the size of data generated by scientific applications necessitates collaboration and sharing data among the nation's education and research institutions. To address this, distributed storage systems spanning multiple institutions over wide area networks have been developed. One of the important features of distributed storage systems is providing global unified name space across all participating institutions, which enables easy data sharing without the knowledge of actual physical location of data. This feature depends on the ``location metadata'' of all data sets in the system being available to all …


Investigation Into The Hydrothermal Treatment Of Sugarcane Bagasse Under Near- And Supercritical Conditions, John E. White Jan 2009

Investigation Into The Hydrothermal Treatment Of Sugarcane Bagasse Under Near- And Supercritical Conditions, John E. White

LSU Doctoral Dissertations

Processing biomass in near- and supercritical water has garnered increasing attention because of its ability to accept a variety of wet feedstocks, energy efficiency, and ability to regulate the solubility and separation of components. Very few studies of biomass hydrothermal conversion provide a comprehensive evaluation of multiple process parameters and various additives and their effects on a single product phase. This research examined the influence of temperature, residence time, biomass concentration, and particle size on volatiles production from the hydrothermal conversion of sugarcane bagasse. Temperature had the greatest impact on volatile yields with the largest increase (23 wt %) occurring …


Meso-Scale Heating Predictions For Weak Impact Of Granular Energetic Solids, Rohan Panchadhara Jan 2009

Meso-Scale Heating Predictions For Weak Impact Of Granular Energetic Solids, Rohan Panchadhara

LSU Doctoral Dissertations

An explicit, two-dimensional, Lagrangian finite and discrete element technique is formulated and used to computationally characterize meso-scale fluctuations in thermomechanical fields induced by low pressure deformation waves propagating through particulate energetic solids. Emphasis is placed on characterizing the relative importance of plastic and friction work as meso-scale heating mechanisms which may cause bulk ignition of these materials and their dependence on piston speed (vp ~ 50-500 m/s). The numerical technique combines conservation principles with a plane strain, thermoelastic-viscoplastic constitutive theory to describe deformation within the material meso-structure. An energy consistent, penalty based, distributed potential force method, coupled to a penalty …


Development And Operational Analysis Of Highway Alternating Merge Transition Zones, Wakeel Ishola, Anthony Idewu Jan 2009

Development And Operational Analysis Of Highway Alternating Merge Transition Zones, Wakeel Ishola, Anthony Idewu

LSU Doctoral Dissertations

The design and control of work zone traffic control areas is governed by standards published by the United States Department of Transportation (US-DOT) and documented in the Manual for Uniform Control Devices (MUTCD). While these configurations have evolved over time to reflect safer and more efficient management practices and have become familiar to drivers, they are also recognized as areas of vehicle conflict that can cause congestion and safety problems. As part of this research, a new design has been developed that has the potential to lessen the detrimental effects of lane closures in work zones. This new concept, known …


Large Eddy Simulation Of Turbulent Premixed Combustion In Gas Turbines, Ashoke De Jan 2009

Large Eddy Simulation Of Turbulent Premixed Combustion In Gas Turbines, Ashoke De

LSU Doctoral Dissertations

An artificially Thickened Flame (TF) approach based on LES framework is used to model the turbulent premixed combustion in gas turbine combustors. A number of variants of the Thickened Flame approach including a modified version of TF model have been studied in details. In the TF model, the flame front is artificially thickened to resolve on LES computational grid. With this approach, reaction rate modeling does not require any ad-hoc closure assumptions. However, suitable modifications have to be made to compensate for flame thickening. To verify the predictive capability of the models, a stoichiometric methane-air flame on Bunsen burner type …


Scheduling And Reconfiguration Of Interconnection Network Switches, Krishnendu Roy Jan 2009

Scheduling And Reconfiguration Of Interconnection Network Switches, Krishnendu Roy

LSU Doctoral Dissertations

Interconnection networks are important parts of modern computing systems, facilitating communication between a system's components. Switches connecting various nodes of an interconnection network serve to move data in the network. The switch's delay and throughput impact the overall performance of the network and thus the system. Scheduling efficient movement of data through a switch and configuring the switch to realize a schedule are the main themes of this research. We consider various interconnection network switches including (i) crossbar-based switches, (ii) circuit-switched tree switches, and (iii) fat-tree switches. For crossbar-based input-queued switches, a recent result established that logarithmic packet delay is …


An Uncertainty-Based Approach To The Total Maximum Daily Load Development, Abhijit Patil Jan 2009

An Uncertainty-Based Approach To The Total Maximum Daily Load Development, Abhijit Patil

LSU Doctoral Dissertations

A Bayesian-updating approach is developed to the estimation of the total uncertainty-based Margin of Safety (MOS) for Total Maximum Daily Load calculations using the watershed modeling tool HSPF. In order to determine the prior, likelihood, and posterior distributions of uncertainties involved in Bayesian approach, various probability density functions are derived. The temperature measurement induced uncertainty in dissolved oxygen simulation is found to be normally distributed. The temporal scale uncertainty in weather data decreases with decreasing temporal resolution. The temporal-scale uncertainties in the rainfall and temperature data follow a Weibull and general extreme value distributions, respectively. The spatial-resolution uncertainty in simulated …


Slab-On-Girder Prestressed Concrete Bridges: Linear And Nonlinear Finite Element Analysis And Experimental Load Tests, Marcio Costa Araujo Jan 2009

Slab-On-Girder Prestressed Concrete Bridges: Linear And Nonlinear Finite Element Analysis And Experimental Load Tests, Marcio Costa Araujo

LSU Doctoral Dissertations

“A diaphragm is a transverse stiffener, which is placed between girders in order to maintain section geometry”, (AASHTO, 2002). Intermediate diaphragms, usually placed at the midspan or third points of a bridge, are thought to contribute to the overall distribution of live loads in bridges. Cast-in-place concrete intermediate diaphragms were investigated in this study in order to assess their load distribution effectiveness in prestressed concrete I-girder bridges. Finite element packages (Ansys and GT STRUDL) were used to perform the analyses for multiple bridge configurations, including a parametric study of span length, girder spacing, and concrete strength. It was found that …


Multiphase Flows In Polymer Microfluidic Systems, Namwon Kim Jan 2009

Multiphase Flows In Polymer Microfluidic Systems, Namwon Kim

LSU Doctoral Dissertations

Continuous delivery of segmented reagents using pressure-driven multiphase flow in microchannels is a promising technology for high throughput microfluidic bioassays. Separation and encapsulation of the target reagents with another inert fluid provide many advantages over single phase flow in microfluidic applications of biotechnology. In order to achieve these advantages and control these multiphase flows, it is necessary to understand their generation and transport characteristics as influenced by geometrical miniaturization, channel wall properties, the effects of surfactants and operating conditions. For gas-liquid two-phase flow, dry air and deionized water were driven into hot embossed PMMA microchannels with 200 μm square test …


Sialic Acid Conjugated Chitosan For The Attenuation Of Amyloid-Beta Toxicity, Dhruva Dilip Dhavale Jan 2009

Sialic Acid Conjugated Chitosan For The Attenuation Of Amyloid-Beta Toxicity, Dhruva Dilip Dhavale

LSU Master's Theses

Amyloid-beta (Aβ), a 39 to 43 amino acid long peptide, is the primary species identified in senile plaques associated with Alzheimer’s disease (AD) and has been implicated in the neurotoxicity associated with AD. It is believed that Aβ toxicity is mediated through the interaction with neuronal membranes. A variety of evidence indicates that 1) Aβ may bind to the cell surface sialic acids, 2) the affinity of this interaction is higher if the gangliosides or sialic acids on the cell surface are clustered, 3) the removal of the surface sialic acids attenuate Aβ toxicity. Based on this data, we hypothesized …