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Theses/Dissertations

2005

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Full-Text Articles in Engineering

Geostatistical Integration Of Geophysical, Well Bore And Outcrop Data For Flow Modeling Of A Deltaic Reservoir Analogue, Hong Tang Jan 2005

Geostatistical Integration Of Geophysical, Well Bore And Outcrop Data For Flow Modeling Of A Deltaic Reservoir Analogue, Hong Tang

LSU Doctoral Dissertations

Significant world oil and gas reserves occur in deltaic reservoirs. Characterization of deltaic reservoirs requires understanding sedimentary and diagenetic heterogeneity at the submeter scale in three dimensions. However, deltaic facies architecture is complex and poorly understood. Moreover, precipitation of extensive calcite cement during diagenesis can modify the depositional permeability of sandstone reservoir and affect fluid flow. Heterogeneity contributes to trapping a significant portion of mobile oil in deltaic reservoirs analogous of Cretaceous Frontier Formation, Powder River Basin, Wyoming. This dissertation focuses on 3D characterization of an ancient deltaic lobe. The Turonian Wall Creek Member in central Wyoming has been selected …

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Modeling The Fate And Transport Of Chlorinated Benzenes In Baton Rouge Bayou, Sudheer Nimmagadda Jan 2005

Modeling The Fate And Transport Of Chlorinated Benzenes In Baton Rouge Bayou, Sudheer Nimmagadda

LSU Master's Theses

Knowledge of the fate and transport of chlorinated benzenes is necessary at certain sites for effective remediation of contaminated soils using plants. Current research is examining the capability of wetland plants to catalyze degradation or attenuate migration, but again requires knowledge of the uptake of contaminants from an aqueous environment. A two stage model was used to estimate the rate of uptake of contaminants from sediments. The first stage of the model predicts pollutant leaching rates from sediments to the overlying water, which would then be fed into the plant or bioreactor model systems. In this study the flux from …

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Distributed Airlift Systems Design With Application To Recirculating Soft Shell Crawfish Shedding Systems, Sripavani Gudipati Jan 2005

Distributed Airlift Systems Design With Application To Recirculating Soft Shell Crawfish Shedding Systems, Sripavani Gudipati

LSU Master's Theses

Soft shell crawfish, a seafood delicacy, has a potential market for growth in the aquaculture industry. Since the industry's collapse in the 1990's, the advent of new technologies like eyestalk ablation, automated hydraulic separation and distributed airlift systems has elevated the hope for restoration. In a distributed airlift system, airlifts and distribution pipes supply water to holding trays. Airlifts are simple devices used to pump water by injecting air at the bottom of an open pipe. The combination of airlifts and distribution pipes has potential economic benefits for low head applications in recirculating aquaculture systems. This thesis focuses on guidelines …

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Computational Model For Elasto-Plastic And Damage Analysis Of Plates And Shells, Pawel Benedykt Woelke Jan 2005

Computational Model For Elasto-Plastic And Damage Analysis Of Plates And Shells, Pawel Benedykt Woelke

LSU Doctoral Dissertations

Shells and plates are very important for various engineering applications. Analysis and design of these structures is therefore continuously of interest to the scientific and engineering community. Accurate and conservative assessments of the maximum load carried by the structure, as well as the equilibrium path in both elastic and inelastic range are of paramount importance. Elastic behaviour of shells has been very closely investigated, mostly by means of the finite element method. Inelastic analysis on the other hand, especially accounting for damage effects, has received much less attention from the researchers. A computational model for finite element, elasto-plastic and damage …

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Effects Of Strong Surface Energy Anisotropy On Stationary And Migrating Grain-Boundary Grooves, Donghong Min Jan 2005

Effects Of Strong Surface Energy Anisotropy On Stationary And Migrating Grain-Boundary Grooves, Donghong Min

LSU Doctoral Dissertations

Grain-boundary migration controls grain growth and is important in materials processing and synthesis. When a grain boundary ends at a free surface, a groove will develop at the tip to reduce the combined surface and grain-boundary energies. This groove may hinder the grain boundary movement and its effect needs to be understood. Previous studies have solved the groove profile for stationary or migrating grain boundaries by assuming small groove slopes with isotropic surface free energy. This work extends the analysis to finite slopes with isotropic or anisotropic surface free energy.
We first study migrating grain-boundary grooves with isotropic surface energy …

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Evidence Of Neotectonic Activity In Southwest Louisiana, Jordan Oliver Heltz Jan 2005

Evidence Of Neotectonic Activity In Southwest Louisiana, Jordan Oliver Heltz

LSU Master's Theses

A methodology that combines high-resolution topographic mapping, field observations, subsurface evaluation, and geodetic data analysis has successfully located several fault-related geomorphic steps in an area of southwestern Louisiana once thought to be relatively devoid of such features. Comparison of height differences of benchmarks straddling these suspected fault-related steps shows that vertical displacement rates on faults in the study area ranged from about 2 mm/yr to as much as 6 mm/yr during the 1960’s and 1970’s. However, leveling data obtained as recently as January 2005 reveals that the majority of these faults are currently moving at rates of less than 1 …

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A Project Improvement System For Effective Management Of Construction Projects, Shahriyar Mojahed Jan 2005

A Project Improvement System For Effective Management Of Construction Projects, Shahriyar Mojahed

LSU Doctoral Dissertations

The concept of construction productivity began in the early 20th century with a series of time and motion studies to improve bricklaying operations. A substantial number of subsequent studies focused on repetitive tasks and automation of the manufacturing operations and subsequently benefited manufacturing more than the construction industry. There has been a lack of studies for productivity improvement in the construction industry. Building upon the available body of knowledge as it related to productivity of manufacturing and construction industries, this study focused on developing a project improvement system for effective management of construction projects. Development of the system included a …

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Performance Of Disc Brushless Dc Motor Applied As Gearless Drive For Wheelchair, Deepti Rao Chikkam Jan 2005

Performance Of Disc Brushless Dc Motor Applied As Gearless Drive For Wheelchair, Deepti Rao Chikkam

LSU Master's Theses

The currently used electric drive for a wheelchair consists of brush permanent magnet DC motor and mechanical transmission that drives the wheels. The overall efficiency of this kind of drive usually does not exceed 60%. At present there is under study much more effective drive that consists of brushless DC motor which embedded into the wheel rim directly drives the wheelchair. This type of high efficiency gearless drive is the object of this thesis project. The particular brushless DC motor is a torus - type motor with a high energy rare - earth magnets and ferromagnetic teeth that fill in …

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Power Supply Current [Ips] Based Testing Of Cmos Amplifier Circuit With And Without Floating Gate Input Transistors, Vanikumari Pulendra Jan 2005

Power Supply Current [Ips] Based Testing Of Cmos Amplifier Circuit With And Without Floating Gate Input Transistors, Vanikumari Pulendra

LSU Master's Theses

This work presents a case study, which attempts to improve the fault diagnosis and testability of the power supply current based testing methodology applied to a typical two-stage CMOS operational amplifier and is extended to operational amplifier with floating gate input transistors*. The proposed test method takes the advantage of good fault coverage through the use of a simple power supply current measurement based test technique, which only needs an ac input stimulus at the input and no additional circuitry. The faults simulating possible manufacturing defects have been introduced using the fault injection transistors. In the present work, variations of …

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Intrinsic Stress And High Temperature Properties Of Metal-Contanining Hydrogenated Amorphous Carbon Coatings, Bo Shi Jan 2005

Intrinsic Stress And High Temperature Properties Of Metal-Contanining Hydrogenated Amorphous Carbon Coatings, Bo Shi

LSU Doctoral Dissertations

A detailed examination of the intrinsic stress development and mechanical properties of titanium-containing hydrogenated amorphous carbon (Ti-C:H) and W-C:H coatings, deposited in an inductively coupled plasma (ICP) assisted hybrid chemical/physical vapor deposition (CVD/PVD) environment was carried out. Intrinsic stresses within those coatings were found to be compressive and dependent on compositions. The intrinsic compression within Ti-C:H was further shown to be significantly influenced by the energy of ionic species bombarding the substrate during growth. The results suggested that ion bombardment played a significant role in intrinsic stress generation within Ti-C:H, and was likely to influence stress development in other low …

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Modeling Of Chemical Fate And Transport In The Environment, Andre Marquette Jan 2005

Modeling Of Chemical Fate And Transport In The Environment, Andre Marquette

LSU Master's Theses

The Environmental Engineering discipline remains on the forefront of discovery due to advancements in computer technology, advancements in experimental methods and an ever increasing public interest in mitigating the harmful effects of the chemical process industry. Experimental methods have a critical role in defining environmental processes and effects but are limited in their ability to predict future environmental conditions. Conceptual and mathematical models are needed in order to evaluate the effect of environmental conditions far into the future as well as to extend and apply the knowledge gained from experimentation. Models can be used to predict chemical exposure levels, design …

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Physical Model Experiments Of The Gas-Assisted Gravity Drainage Process, Amit P. Sharma Jan 2005

Physical Model Experiments Of The Gas-Assisted Gravity Drainage Process, Amit P. Sharma

LSU Master's Theses

The displacement of oil by gas injection in oil reservoirs is an attractive method of improved oil recovery. Commercial gravity-stable gas injection projects have demonstrated excellent recoveries; however, their application has been limited to dipping reservoirs and pinnacle reefs. Horizontal gas floods and the water alternating gas (WAG) processes, practiced in horizontal type reservoirs, have yielded less than satisfactory recoveries of 5-10%. The Gas Assisted Gravity Drainage (GAGD) Process being developed at LSU extends the concept of gravity-stable gas floods to horizontal type reservoirs to improve volumetric sweep and oil recovery. This experimental study consists of a series of visual …

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Computer-Aided Diagnosis Tool For The Detection Of Cancerous Nodules In X-Ray Images, Pallavi Bomma Jan 2005

Computer-Aided Diagnosis Tool For The Detection Of Cancerous Nodules In X-Ray Images, Pallavi Bomma

LSU Master's Theses

This thesis involves development of a computer-aided diagnosis (CAD) tool for the detection of cancerous nodules in X-ray images. Both cancerous and non-cancerous regions appear with little distinction on an X-ray image. For accurate detection of cancerous nodules, we need to differentiate the cancerous nodules from the non-cancerous. We developed an artificial neural network to differentiate them. Artificial neural networks (ANN) find a large application in the area of medical imaging. They work in a manner rather similar to the brain and have good decision making criteria when trained appropriately. We trained the neural network by the backpropagation algorithm and …

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Thermal Management Of The Lsu Micro Gas Chromatograph, Praveen K. Pasupuleti Jan 2005

Thermal Management Of The Lsu Micro Gas Chromatograph, Praveen K. Pasupuleti

LSU Master's Theses

Gas chromatography is a technique widely used for the separation and analysis of gas samples. Gas chromatographs are used for environmental maintenance, monitoring sophisticated biological analyses, and to separate components from a mixture of gases for mass spectrometer analysis. There has been a tremendous interest in miniaturization of gas chromatograph systems because of the potential for portability, faster response time, lower dead volume, lower power consumption, and lower cost of operation. Conventional gas chromatography keeps the column at a constant temperature during separation, which is called isothermal analysis. Temperature programming is a mode of gas chromatography in which the column …

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Synthesis Of Poly(Dl-Lactide-Co-Glycolide) Nanoparticles With Entrapped Magnetite, Carlos Ernesto Astete R. Jan 2005

Synthesis Of Poly(Dl-Lactide-Co-Glycolide) Nanoparticles With Entrapped Magnetite, Carlos Ernesto Astete R.

LSU Master's Theses

The goal of the research was to synthesize magnetic polymeric nanoparticles (MPNPs) under 100 nm in diameter, for future drug delivery applications. The thesis is divided into two main sections. In the first section, a quantitative, and comprehensive description of the top-down synthesis techniques available for poly(lactide-co-glycolide) (PLGA) and magnetic polymeric nanoparticles (MPNPs) formation is provided, as well as the techniques commonly used for nanoparticle characterization. In the second part, a novel way to form MPNPs is presented. The emulsion evaporation method was selected as the method of choice to form poly(lactide-co-glycolide) (PLGA) nanoparticles with entrapped magnetite (Fe3O …

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Simulation And Economic Evaluation Of Coal Gasification With Sets Reforming Process For Power Production, Zachary Hoffman Jan 2005

Simulation And Economic Evaluation Of Coal Gasification With Sets Reforming Process For Power Production, Zachary Hoffman

LSU Master's Theses

Increasing natural gas prices have raised interest in alternate energy resources. Popular belief in the connection between carbon dioxide emissions and global warming has motivated the search for a technique to isolate carbon dioxide from combustion stack gases. Coal gasification with SETS reforming has been proposed as a solution to both of these issues in that it provides an alternate energy source and 100% carbon dioxide sequestration. The purpose of this research is to simulate this process using AspenPlus to perform the rigorous material and energy balances. The results of this simulation are used to carry out a complete economic …

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Heuristics For Memory Access Optimization In Embedded Processors, Saravanan Subramanian Jan 2005

Heuristics For Memory Access Optimization In Embedded Processors, Saravanan Subramanian

LSU Master's Theses

Digital signal processors (DSPs) such as the Motorola 56k are equipped with two memory banks that are accessible in parallel in order to offer high memory bandwidth, which is required for high-performance applications. In order to make efficient use of the memory bandwidth offered by two or more memory banks, compilers for such DSPs should be capable of appropriately partitioning the program variables between the two memory banks and scheduling accesses. If two variables can be accessed simultaneously, then it is essential to have these two variables assigned to two different memory banks. Also if these two variables are in …

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Flow And Temperature Measurements In A Linear Turbine Blade Passage With Leading Edge And Endwall Contouring And With And Without Film Cooling, Ross James Gustafson Jan 2005

Flow And Temperature Measurements In A Linear Turbine Blade Passage With Leading Edge And Endwall Contouring And With And Without Film Cooling, Ross James Gustafson

LSU Master's Theses

Gas turbine efficiency can be improved by increasing the turbine inlet temperature. Secondary flows created in the turbine blade passage cause pressure losses and increase the thermal blade loading on the endwall, thus limiting the combustion temperature. Pressure losses, or aerodynamic losses, extract energy from the fluid, leaving less for torque or thrust production. Secondary flows also cause greater non-uniformity in the exit flow from each blade stage, which decreases the stage efficiency. Weakening secondary flows will lower pressure losses and endwall heat transfer. The following research will explore concepts for weakening the secondary flows through the use of (a) …

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Molecular Dynamics Simulations Of Biological Membranes In The Presence Of Cryoprotectants, Dinesh Pinisetty Jan 2005

Molecular Dynamics Simulations Of Biological Membranes In The Presence Of Cryoprotectants, Dinesh Pinisetty

LSU Master's Theses

Cryopreservation is a process that is characterized by the transport of water and cryoprotectants through the cell membrane. This phenomenon has been studied in extensive detail at the macroscopic (µm) scale but in a somewhat more limited fashion at the microscopic (nm) scale. In this study we develop several lipid bilayer models to approximate a cell membrane (nm) and present the effect of several different cryoprotectants on the structural characteristics of these lipid bilayers using molecular dynamic simulations. The lipid bilayer models included dipalmitoylphosphatidylcholine (DPPC), dimyristoylphosphatidylcholine (DMPC) and palmitoyleylphosphatidylcholine (POPC) while the cryoprotectants included methanol and dimethylsulfoxide (DMSO). The molecular …

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Zeolite And Metal Oxide Catalysts For The Production Of Dimethyl Sulfide And Methanethiol, Craig Plaisance Jan 2005

Zeolite And Metal Oxide Catalysts For The Production Of Dimethyl Sulfide And Methanethiol, Craig Plaisance

LSU Master's Theses

Metal oxide and zeolite catalysts were examined to determine their suitability for the production of methanethiol and dimethyl sulfide from the condensation of methanol and hydrogen sulfide. Fixed bed reactor experiments were used to test the catalysts in these processes. The acid sites of these catalysts were characterized by investigating the thermal desorption of 1-propanamine from these sites. It was found that WO3/ZrO2, La2O3/Al2O3, g-Al2O3, and HZSM-5 catalysts were active and selective in the production of dimethyl sulfide. On these four catalysts, the reaction converting methanol to dimethyl ether and the methanethiol disproportionation reaction were fast and close to equilibrium. …

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A Robust Noise Spectral Estimation Algorithm For Speech Enhancement In Voice Devices, Brett Joseph Chessher Jan 2005

A Robust Noise Spectral Estimation Algorithm For Speech Enhancement In Voice Devices, Brett Joseph Chessher

LSU Master's Theses

In this thesis, a new robust noise spectral estimation algorithm is proposed for the purpose of single-microphone speech enhancement. This algorithm can generate the optimal noise spectral estimates in the Minimum Mean Square Error (MMSE) sense based on the speech statistics in the noisy environments. Compared to the well-adopted conventional noise spectral estimation method using the single-pole recursion, our proposed scheme is more reliable since the recursion coefficients are adaptable and optimal in the MMSE therein. We also propose a new accurate Resulting Signal-to-Noise Ratio (R-SNR) estimator as a quality measure to benchmark the existing noise spectral estimation techniques. This …

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Development Of An Alternative Approach To Estimate Vehicle Miles Traveled Using A Classification Procedure, Srividya Vadlamani Jan 2005

Development Of An Alternative Approach To Estimate Vehicle Miles Traveled Using A Classification Procedure, Srividya Vadlamani

LSU Master's Theses

In this study a Classification and Regression Tree (CART) classification system method was developed as an alternative to the HPMS conventional method of VMT estimation. Louisiana Highway Performance Monitoring System (HPMS) data from Federal Highway Administration (FHWA) and Louisiana highway network data from Louisiana Department of Transportation (LADOTD) were used to carry out the analysis. The CART classification was derived based on link attributes that effectively distinguished the homogeneous traffic volume sections. VMT estimation on individual links as well for the different systems was calculated using the CART classification system and the values were assigned on each link. The default …

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Modeling Destination Choice In Hurricane Evacuation With An Intervening Opportunity Model, Bin Chen Jan 2005

Modeling Destination Choice In Hurricane Evacuation With An Intervening Opportunity Model, Bin Chen

LSU Master's Theses

In this study, a trip distribution model for hurricane evacuation using the intervening opportunity method was developed. Post Hurricane Floyd survey data was used for model calibration and comparison. To model the behavior that people tend to evacuate away from the path of the hurricane, a new concept of equal destination attractiveness was introduced and an extended intervening opportunity model was built on this basis and implemented in TransCAD. The gravity model, intervening opportunity model and its extended version were compared using several statistical measures. This study demonstrates that it is possible to use the intervening opportunity theory to model …

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Mesoscopic Simulation Of Grain Boundary Diffusion Creep In Inhomogeneous Microstructures, Kanishk Rastogi Jan 2005

Mesoscopic Simulation Of Grain Boundary Diffusion Creep In Inhomogeneous Microstructures, Kanishk Rastogi

LSU Master's Theses

At high temperatures, stresses well below the material’s tensile yield strength can induce permanent deformation over a period of time. This time-dependent progressive deformation of a material at constant stress is called Creep and is observed in both crystalline and non-crystalline solids. The principal deformation processes contributing to creep deformation are slip, sub-grain formation and grain-boundary sliding. Mechanisms involving creep of crystalline materials involve either dislocation motion or diffusional flow of atoms or both. Extensive studies have been done to ascertain the creep mechanism in various regimes of temperature and applied stresses. At low stresses and high temperatures, grain boundary …

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Deposition Of Carbon Layers From Cyclohexane By Thermal Chemical Vapor Deposition, Bharath Thiruvengadachari Jan 2005

Deposition Of Carbon Layers From Cyclohexane By Thermal Chemical Vapor Deposition, Bharath Thiruvengadachari

LSU Master's Theses

The overall aim of this thesis is to deposit carbon layers by thermal Chemical Vapor Deposition (CVD) and investigate the effects of process parameters on the morphology and structure of the deposited carbon layers. Cyclohexane (C6H12) hydrocarbon is the precursor material used as the source of carbon. A 20% Cu- 80% Ni alloy, deposited by RF magnetron sputtering and annealed at the growth temperature either in an argon flow or in 10% hydrogen-90% argon flow, is used as a catalyst prior to carbon film deposition by CVD. The CVD temperature is varied between 550 0C and 800 0C. The Cu-Ni …

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Enhanced Gas Recovery Using Pressure And Displacement Management, Thomas Walker Jan 2005

Enhanced Gas Recovery Using Pressure And Displacement Management, Thomas Walker

LSU Master's Theses

The work contained in this thesis combines two previous enhanced gas recovery techniques; coproduction of water and gas from water-drive reservoirs and waterflooding of low pressure gas reservoirs. These two techniques allow the control of reservoir pressure and sweep efficiency through planed production or injection of water. A recovery optimization method, which is applicable to any gas reservoir, was developed using the concept of pressure and displacement management (PDM). Two simulation studies were conducted, using Eclipse©, to investigate recovery optimization by coproduction and waterflooding. From the coproduction study it was determined that the water production rate needed to optimize recovery …

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3-Dimensional Flow Measurements In Square Coaxial Jets, Thomas Lagarde Jan 2005

3-Dimensional Flow Measurements In Square Coaxial Jets, Thomas Lagarde

LSU Master's Theses

Results from un-forced experiments conducted in the three-dimensional flow emanating from coaxial contoured nozzles with square cross section and parallel sides are presented and discussed. Two experiments were conducted with the inner to outer jet nominal velocity ratio equal to l=0.5 and l=1.5. The Reynolds number of the outer jet based on the hydraulic diameter of the outer nozzle exit was in both cases 16,000. A multi-position hot-wire anemometry method was used for measurements in the three-dimensional turbulent flow using a dual film sensor (X-probe). A methodology was developed and implemented to derive the mean-velocity components and Reynolds stresses corrected …

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The Electrodeposition And Property Study Of Nickel-Rhenium Alloy, Shirong Wen Jan 2005

The Electrodeposition And Property Study Of Nickel-Rhenium Alloy, Shirong Wen

LSU Master's Theses

The electrodeposition of nickel-rhenium alloys from Ni(II) and Re(VII) solution was studies in an aqueous acidic solution. Different plating current density and pH have been carried out, and the effect of them on the composition of the deposited Ni-Re alloy was studied. Wavelength-dispersive spectrometer (WDS) was used to measure the composition of Ni-Re alloy. The thermal stability of nickel-rhenium alloy system has been investigated. Differential scanning calorimetry (DSC) tests have been conducted for the electroplated Ni-Re samples in order to find the possible heating initiated interactions at elevated temperatures. To investigate the thermal stability of Ni-Re alloys, the samples were …

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Assimilation And Removal Of Phosphorus Within The Marshland Upwelling System, Derek A. Evans Jan 2005

Assimilation And Removal Of Phosphorus Within The Marshland Upwelling System, Derek A. Evans

LSU Master's Theses

The marshland upwelling system (MUS) is an alternative onsite wastewater system that was developed to treat domestic wastewater derived from coastal communities. Previous studies have researched the systems ability to treat fecal coliforms and nitrogen. The objectives of this research were to (1) assess the treatment efficiency of the MUS for removing both total phosphorus and orthophosphate, (2) provide preliminary design and operational guidelines for phosphorus removal, and (3) develop a parameter to project longevity of the MUS for treating phosphorus. Performance efficiency was compared for a system which operated for 23 months located in Bayou Segnette State Park and …

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An In-Situ Capping Design For The Remediation Of Petroleum Contaminated Sediments, Melanie Krystle Harris Jan 2005

An In-Situ Capping Design For The Remediation Of Petroleum Contaminated Sediments, Melanie Krystle Harris

LSU Master's Theses

Historical disposal practices used by oil companies have caused the accumulation of contaminated sediments in their nearby lakes and ponds. These companies are now faced with the challenge of remediating the bodies of water that contain these contaminated sediments. The contaminants that remain in the sediment continue to pose a threat to human health and the environment. For example, high concentrations of polycyclic aromatic hydrocarbons (PAHs), which are still present in the bottom sediments can have toxic effects on aquatic life. One form of remediation for this problem is In-Situ Capping (ISC), which is defined as a method whereby material …

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