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Full-Text Articles in Engineering

Modeling Of River Hydrodynamics And Active Cap Effectiveness In The Anacostia River, Keegan L. Roberts Jan 2004

Modeling Of River Hydrodynamics And Active Cap Effectiveness In The Anacostia River, Keegan L. Roberts

LSU Master's Theses

The Anacostia Active Capping Project (AACP) is a United States Environmental Protection Agency (EPA) funded initiative to develop and implement, on a field scale, active capping barrier technologies. Overseen by the Hazardous Substance Research Center, South and Southwest (HSRC), the AACP plans to demonstrate the ability of active capping barrier technologies to prevent the migration of contaminants from the sediment bed to the overlying water column of the Anacostia River. The demonstration project will involve the placement and monitoring of four individual types of capping materials (apatite, Aquablok, coke breeze, and sand) and the monitoring of one control (i.e. uncapped) …


First Order Sigma-Delta Modulator Of An Oversampling Adc Design In Cmos Using Floating Gate Mosfets, Syam Prasad Sbs Kommana Jan 2004

First Order Sigma-Delta Modulator Of An Oversampling Adc Design In Cmos Using Floating Gate Mosfets, Syam Prasad Sbs Kommana

LSU Master's Theses

We report a new architecture for a sigma-delta oversampling analog-to-digital converter (ADC) in which the first order modulator is realized using the floating gate MOSFETs at the input stage of an integrator and the comparator. The first order modulator is designed using an 8 MHz sampling clock frequency and implemented in a standard 1.5µm n-well CMOS process. The decimator is an off-chip sinc-filter and is programmed using the VERILOG and tested with Altera Flex EPF10K70RC240 FPGA board. The ADC gives an 8-bit resolution with a 65 kHz bandwidth.


Watermarking Using Decimal Sequences, Navneet Kumar Mandhani Jan 2004

Watermarking Using Decimal Sequences, Navneet Kumar Mandhani

LSU Master's Theses

This thesis introduces the use of decimal sequences in watermarking to hide information for authentication. The underlying system is based on code division multiple access (CDMA), which is a form of spread spectrum communication. Different algorithms for the use of decimal sequences have been formulated for use in black and white images. The watermark is spread across the carrier image by using the d- sequences of optimal period and retrieval is made by the use of correlation. Matlab version 6.5 was used to implement the algorithms discussed in this thesis. The advantage of using d-sequences over PN sequences is that …


Development Of Resilient Modulus Prediction Models For Base And Subgrade Pavement Layers From In Situ Devices Test Results, Ravindra Gudishala Jan 2004

Development Of Resilient Modulus Prediction Models For Base And Subgrade Pavement Layers From In Situ Devices Test Results, Ravindra Gudishala

LSU Master's Theses

Currently, the design of flexible pavements is generally conducted based on static properties such as California Bearing Ratio and soil support value. These properties do not represent the actual response of the pavement layers under traffic loadings. Recognizing this deficiency, the current and the 2002 mechanistic –empirical guide for design of pavement structures recommended the use of resilient modulus for characterizing the base and subgrade soil and for the design of flexible pavements. The objective of this study was to develop models to estimate the resilient modulus of base and subgrade soils from in situ test devices. Two types of …


Impact Of Static Flexion Duration On The Development Of A Neuromuscular Disorder Of The Lumbar Spine, Rebecca Victoria Labry Jan 2004

Impact Of Static Flexion Duration On The Development Of A Neuromuscular Disorder Of The Lumbar Spine, Rebecca Victoria Labry

LSU Master's Theses

Many occupational groups work under adverse conditions in which their spinal columns are fully flexed under load for substantial periods of time. This study was designed to determine the response of the lumbar spine to a static load of a substantial duration under a range of load magnitudes. The impact of static loads of 20, 40 and 60N were applied over 30 min flexion, 10 min rest, and 30 min flexion (for a total of one hour exposure) followed by a 7 h rest. Lumbar viscoelastic creep (laxity) and reflex electromyographic (EMG) activity were monitored over both flexion periods and …


Towards Automated Capture Of 3d Foot Geometry For Custom Orthoses, Rajeev Madazhy Jan 2004

Towards Automated Capture Of 3d Foot Geometry For Custom Orthoses, Rajeev Madazhy

LSU Master's Theses

This thesis presents a novel method of capturing 3D foot geometry from images for custom shoe insole manufacture. Orthopedic footwear plays an important role as a treatment and prevention of foot conditions associated with diabetes. Through the use of customized shoe insoles, a podiatrist can provide a means to better distribute the pressure around the foot, and can also correct the biomechanics of the foot. Different foot scanners are used to obtain the geometric plantar surface of foot, but are expensive and more generic in nature. The focus of this thesis is to build 3D foot structure from a pair …


Bacterial Plume Dynamics In The Marshland Upwelling System Employed In The Near Freshwater Conditions, Benjamin Kojo Addo Jan 2004

Bacterial Plume Dynamics In The Marshland Upwelling System Employed In The Near Freshwater Conditions, Benjamin Kojo Addo

LSU Master's Theses

The marshland upwelling system (MUS) was installed in a floatation marsh along the banks of the Bayou Segnette Waterway, Louisiana. This site was characterized by native groundwater of low salinity regime. Previous studies focused on the removal of fecal pathogens from settled/raw and secondarily treated wastewater under high saline groundwater conditions. The objectives of this research were to: 1) quantify the impact of natural die-off on bacterial removal within the MUS, 2) determine bacterial retardation rates in laboratory-repacked sandy loam soil columns, and 3) evaluate the effectiveness of the MUS in removing fecal pathogens from settled, raw wastewater. Varying salinities …


Probabilistic Risk Assessment Method For Prioritization Of Risk Factors, Jay Tarakkumar Shah Jan 2004

Probabilistic Risk Assessment Method For Prioritization Of Risk Factors, Jay Tarakkumar Shah

LSU Master's Theses

Risk management involves assessing the risk sources and designing strategies and procedures to mitigate those risks to an acceptable level. Measurement of risk factors plays an important role in the assessment of risk. This research proposes to develop risk assessment frameworks and mathematical model (Probabilistic Risk Assessment model) identify the risk factors. Quantification and prioritization of risk factors will help to design controls, resource allocation policies and minimize the total cost using the Cost Minimization model. The proposed models are applied to a complex system that is representative of actual business situations.


Metal-Doped Rare Earth Oxide Catalysts For Condensations To Ketones, Arvind Karkal Bhat Jan 2004

Metal-Doped Rare Earth Oxide Catalysts For Condensations To Ketones, Arvind Karkal Bhat

LSU Master's Theses

Metal-doped supported rare earth oxide catalysts were examined to determine their suitability for the decarboxylative condensation of two carboxylic acids to produce ketones. The catalysts were characterized based on chemisorption tests, coke analysis using thermo-gravimetric analysis and X-ray absorption spectroscopy. Effect of catalyst particle size on rate of reaction was studied for various supported cerium oxide catalysts. Catalysts were tested for activity, selectivity, and stability using isothermal fixed bed reactors. Optimal operating conditions for the production of diisopropyl ketone and methyl nonyl ketone were determined. It was found that supported cerium oxide catalysts effectively catalyzed the condensation of isobutyric acid …


Heat/Mass Transfer In Smooth And Ribbed Rectangular Serpentine Passages Of Different Aspect Ratio's And Orientation, Peeyush Agarwal Jan 2004

Heat/Mass Transfer In Smooth And Ribbed Rectangular Serpentine Passages Of Different Aspect Ratio's And Orientation, Peeyush Agarwal

LSU Master's Theses

An experimental study of heat/mass transfer in rectangular smooth and ribbed serpentine passages with and without rotation in two different aspect ratios (1:4 and 4:1) channel is performed for two different orientations of the test section (90-degree and 45-degree). The Reynolds number is varied in the range of 5,000 to 40,000 and rotation numbers in the range of 0-0.12. Such passages are encountered close to the mid-chord sections or towards the trailing edge of the turbine blade. Two different configurations of the Normal ribs (e/Dh=0.3125, P/e=8 and e/Dh=0.156, P/e=11.2) are placed on the leading and the …


Fabrication And Assembly Of An Array Of Micro Fuel Injector Nozzles For A Trapped-Vortex Combustor, Tracy Ettel Morris Jan 2004

Fabrication And Assembly Of An Array Of Micro Fuel Injector Nozzles For A Trapped-Vortex Combustor, Tracy Ettel Morris

LSU Master's Theses

An array of four fuel injector nozzles, each with micrometer-scale swirlers and a microhole, is created on a single coupon. The nozzles are intended to atomize fuel to blend with swirling air before ejecting into a trapped-vortex combustion chamber. A first-generation metal prototype is fabricated in order to form the micro features, supply the fuel and gas to the nozzles, and guide the mixture to the combustion chamber. Microfabrication methods and precision machining are used to create a multiple plate laminate assembly. The central plate contains the four microholes, which atomize the fuel, and facilitate the swirler structures needed to …


Effects Of Pressure Suit And Race On Functional Reach, Static And Dynamic Strength, Nageswara Rao Uppu Jan 2004

Effects Of Pressure Suit And Race On Functional Reach, Static And Dynamic Strength, Nageswara Rao Uppu

LSU Master's Theses

In the design of any manual workspace, it is important for the designers to have access to data that can illustrate reach capabilities under real-time work situation. Wearing bulky clothing (pressure suit) and protective restraints (seat or shoulder harness belts) is often mandatory in high acceleration work environments. Clothing and personal equipment worn can influence the functional reach and strength values since they add to the body size. The present study was conducted to investigate the effect of wearing a VKK-6M pressure suit on functional reach limitations and strength values. The technology of incorporating body dimensions into cockpit design primarily …


Assessment Of Shearing Phenomenon And Porosity Of Porous Media Using Microfocus Computed Tomography, Bashar Adeeb Alramahi Jan 2004

Assessment Of Shearing Phenomenon And Porosity Of Porous Media Using Microfocus Computed Tomography, Bashar Adeeb Alramahi

LSU Master's Theses

Microfocus x-ray computed tomography (μCT) is a powerful non-destructive scanning technique to study the internal fabric of granular materials. In this thesis, μCT was applied to two cases. The first case involves studying the behavior of particles in a triaxial specimen during shearing. Three-dimensional translation and rotation of the particles were tracked throughout the shearing process, and they were used to calculate the local strain distributions. Moreover, the local dilatancy angle distribution was calculated throughout experiment. These distributions were compared to study the changes in the behavior of the particles at different stages of the test. It was noticed that …


Application Of Stochastic Downscaling Techniques To Global Climate Model Data For Regional Climate Prediction, Suchita Potta Jan 2004

Application Of Stochastic Downscaling Techniques To Global Climate Model Data For Regional Climate Prediction, Suchita Potta

LSU Master's Theses

Global warming is the most important issue of the present day that affects the climate drastically. This research was carried out to find out the effects of Global warming on Louisiana in future on a very finer spatial and temporal scale. For this purpose spatial downscaling technique is used, where finer resolution climate information is derived from a coarser resolution Global Climate Model (GCM) output. Empirical/statistical downscaling method is used in which sub grid scale changes are calculated as a function of large scale climate. For this purpose a stochastic weather generator and two Global models are considered. The two …


Kinetic Analysis Of Kluyveromyces Marxianus Yeast Strain, Erika Guimaraes Madeira Reeves Jan 2004

Kinetic Analysis Of Kluyveromyces Marxianus Yeast Strain, Erika Guimaraes Madeira Reeves

LSU Master's Theses

This research investigated the growth kinetic parameters (Ks and µmax) of the Kluyveromyces marxianus yeast strain for a batch process under aerobic and anaerobic conditions at 45oC using the Two-Liter Bioflo® 2000 Fermentors and the Orbital Shaker Bed with 250mL flasks (New Brunswick Scientific). This yeast strain was grown in twelve different glucose media concentrations (Anderson et al. 1986), ranging from 200 mg/L to 80,000 mg/L. Several analytical techniques were used, such as COD measurement to determine soluble and total substrate concentrations, TSS and OD measurements to determine biomass formation, HPLC measurements to determine carbohydrate concentrations, and GC measurements to …


Synthesis, Characterization And Tribological Behavior Of Nitrogen-Doped Chromium-Diamond-Like Carbon Nanocomposite Thin Films, Sunil Kumar Pal Jan 2004

Synthesis, Characterization And Tribological Behavior Of Nitrogen-Doped Chromium-Diamond-Like Carbon Nanocomposite Thin Films, Sunil Kumar Pal

LSU Master's Theses

Diamond-like carbon (DLC) films have been extensively studied for more than two decades due to their highly attractive properties. These films exhibit unique mechanical, chemical and electronic properties and thus, possess great potential for applications in tribology. However, two drawbacks in the DLC films are high level of internal stress developed during growth preventing deposition of thick films and low thermal stability. Synthesis of Me-DLC (Cr-DLC and N-doped Cr-DLC) presents a way to overcome these drawbacks. In the present study, DLC, Cr-DLC and N-doped Cr-DLC films were deposited on Si substrate using a hybrid Plasma assisted CVD/PVD process. Film characterization …


An Evaluation Of Methods Used To Obtain The Railroad Preemption Queue Clearance Time, Deeangela Renee Kenon Jan 2004

An Evaluation Of Methods Used To Obtain The Railroad Preemption Queue Clearance Time, Deeangela Renee Kenon

LSU Master's Theses

Because of the potential for serious train-vehicle accidents at or near railroad-highway grade crossings, preemption of traffic signals is a very important supplement to an active warning system. Preemption is the transfer of normal signal phasing to a special control mode with the purpose of clearing any vehicles that are queued within the dynamic envelope as the train approaches, and prohibiting signal phases that would allow additional vehicles in the track area while the train is present. The focus of this research was the determination of the Clear Track Green Interval (or the Queue Clearance Time). The clear track green …


Removal Of Toxic Organics In Wetlands: A Mechanistic Model, Luz Edith Florez Jan 2004

Removal Of Toxic Organics In Wetlands: A Mechanistic Model, Luz Edith Florez

LSU Master's Theses

The ability of removing toxic organic compounds in natural systems is important due to the capacity of these toxicants to increase risk of diseases when they are ingested by humans. This study developed a mechanistic model to estimate the removal efficiency of toxic organics in wetlands using the tanks-in-series model. Sensitivity analyses were performed for different values of the hydraulic loading rate and two kinds of wetlands: bottomland hardwood forest and freshwater marsh. It was observed the effect in the removal efficiency by the number of cell in series was principally perceived for values of N between 1 and 4; …


Improved Opportunity Cost Algorithm For Carrier Selection In Combinatorial Auctions, Viswanath Uma Gnanasekaran Jan 2004

Improved Opportunity Cost Algorithm For Carrier Selection In Combinatorial Auctions, Viswanath Uma Gnanasekaran

LSU Master's Theses

Transportation costs constitute up to thirty percent of the total costs involved in a supply chain. Outsourcing the transportation service requirements to third party logistics providers have been widely adopted, as they are economically more rational than owning and operating a service. Transportation service procurement has been traditionally done through an auctioning process where the auctioneer (shipper) auctions lanes (distinct delivery routes) to bidders (carriers). Individual lanes were being auctioned separately disallowing the carriers to express complements and substitutes. Using combinatorial auctions mechanism to auction all available lanes together would allow the carriers to take advantage of the lane bundles, …


Mems Accelerometer: Proof Of Concept For Geotechnical Engineering Testing, Keith Nicholas Hoffman Jan 2004

Mems Accelerometer: Proof Of Concept For Geotechnical Engineering Testing, Keith Nicholas Hoffman

LSU Master's Theses

Geotechnical engineering materials are inherently variable, which leads to many simplifications when trying to model their behavior. The materials must always be characterized prior to any design work so that the engineer knows which direction he must progress to have a reliable design. Although subsurface characterization techniques and geotechnical design steadily improve, they are by no means infallible. The combination of geotechnical subsurface characterization along with geophysical techniques for improved design and construction monitoring has begun to surface as a viable alternative to the standard techniques in geotechnical engineering. This is important because there is a lack of Quality Control/Quality …


Design Of A Microfabricated Device For Ligase Detection Reaction (Ldr), Dwhyte Omar Barrett Jan 2004

Design Of A Microfabricated Device For Ligase Detection Reaction (Ldr), Dwhyte Omar Barrett

LSU Master's Theses

The Ligase Detection Reaction (LDR) is a mutation detection technique used to identify point mutations in deoxyribonucleic acid (DNA). Developed by Francis Barany and associates at Cornell University it is used to find specific low abundant point mutations that may lead to colorectal cancer in the early stages of disease development. The research objective was to design and manufacture a microscale Ligase Detection Reaction (LDR) device in polycarbonate. The LDR module will be incorporated with other microdevices such as: Continuous Flow Polymerase Chain Reaction (CFRCR) and Capillary Electrophoresis (CE) in modular lab-on-a-chip technology. In making the microdevice, the duration of …


Experimental Validation Of A Smart-Bias Active Magnetic Bearing Controller, Shailesh Pradhananga Jan 2004

Experimental Validation Of A Smart-Bias Active Magnetic Bearing Controller, Shailesh Pradhananga

LSU Master's Theses

Active magnetic bearings (AMBs) are being increasingly employed in the aerospace industry in a variety of devices including compressors, turbines, pumps, and flywheels. One application of great interest to future space missions is the Integrated Power and Attitude Control System (IPACS). The IPACS consists of an arrangement of flywheels that integrates the energy storage and attitude control functions into a single system; thereby, reducing the spacecraft mass, volume, launching cost, and maintenance. Like any energy storage system, flywheels need to be operated with low power losses. AMBs are ideally suited for flywheels because they eliminate mechanical losses (friction). Nevertheless, AMBs …


Analysis And Evaluation Of A Bioengineered Submerged Breakwater, Matthew Dwain Campbell Jan 2004

Analysis And Evaluation Of A Bioengineered Submerged Breakwater, Matthew Dwain Campbell

LSU Master's Theses

Louisiana's coastline has received national attention due to rapid erosion rates estimated from approximately 60 to 100 square kilometers per year. The disappearance of coastal areas jeopardizes public and private infrastructure, property values, aquatic ecosystems, and standards of living. In order to resolve the erosion problem, innovative solutions have been explored that may improve effectiveness and cost efficiency. This research involves a technology, termed an "oysterbreak," which is a bioengineered submerged breakwater. This structure promotes oysters to form a dense structure that dissipates wave energy. Since the structure is biologically dominated, initial material use is modest. The oysterbreak was evaluated …


Mesoscopic Simulation Of Abnormal Grain Growth, Rakesh Kumar Behera Jan 2004

Mesoscopic Simulation Of Abnormal Grain Growth, Rakesh Kumar Behera

LSU Master's Theses

Grain growth is the process that takes place during annealing of polycrystalline materials; its major feature is a systematic increase in grain size. Two different types of grain growth can be distinguished: the normal and abnormal grain growth. During normal grain growth, the microstructure exhibits a uniform increase in grain size with time and the grain size distribution follows the log-normal distribution with the grain sizes ranging from 0 - 2.2 times the average grain size (R). On the contrary, when the abnormal grain growth is the dominant mechanism, there are certain grains (abnormal grains) in the microstructure that grow …


Study Of Characteristics Of Plasma Nitriding And Oxidation Of Superalloy In738lc, Mary Shanti Pampana Jan 2004

Study Of Characteristics Of Plasma Nitriding And Oxidation Of Superalloy In738lc, Mary Shanti Pampana

LSU Master's Theses

IN738LC is a nickel base superalloy, widely used in various applications in turbine engines at high temperatures. Its oxidation and nitriding characteristics were focused in this study. Oxidation kinetics of IN738LC in dry air was studied at selected temperatures, specially chosen depending on the chemical dynamics of the alloy at such high temperatures during annealing. Isothermal oxidation in dry air was carried out at 1000°C, 1090°C, 1140°C and 1190°C. XRD results indicated an interesting onset of preferred orientation in the ã’ depleted layer in all the samples. The XPS and XRD analyses revealed the main oxide phases present in the …


Ultra Deep Su-8 Manufacturing And Characterization For Mems Applications, Charles Joseph Becnel Jan 2004

Ultra Deep Su-8 Manufacturing And Characterization For Mems Applications, Charles Joseph Becnel

LSU Master's Theses

The Micro Systems Engineering Team (mSET) at Louisiana State University (LSU) utilizes microfabrication for a number of heat and mass transfer devices. These include cross flow heat exchangers, mechanical seals with integrated micro heat exchangers, catalytic converters, and micro reactors. In all of these applications, micro honeycomb arrays provide increased surface area per unit volume which significantly enhances heat and mass transfer. In the past, it was only possible to fabricate SU-8 structures approximately 1.5 mm tall. Furthermore, qualitatively, it is much more difficult to fabricate close packed feature arrays than sparse arrays. For many of the previously mentioned applications, …


Stabilization Of Flue Gas Desulfurization Sludge For Application In Marine Environments, Tej Kour Jan 2004

Stabilization Of Flue Gas Desulfurization Sludge For Application In Marine Environments, Tej Kour

LSU Master's Theses

Flue Gas Desulfurization sludge (FGD, CaSO4·2H2O, CaSO3·1/2H2O) is a waste by-product produced when sorbent slurry is passed through wet scrubbers. FGD contains higher concentrations of Ca, S, Si, Fe, Al and Br making it of great environmental concern. Presently only 16% of 24 million metric tons (MT) of FGD sludge produced is being recycled; the rest is disposed in landfills. This research was focused towards stabilizing FGD sludge with Portland Type II cement and Class C fly ash to produce lightweight fill material to be used in the construction of coastal devices. The specific objectives included the development of a …


Effects Of Corrosion Prevention Compounds And Overload Induced Residual Stress Field On Fatigue Life In Aluminum Alloy, Jin Hee Park Jan 2004

Effects Of Corrosion Prevention Compounds And Overload Induced Residual Stress Field On Fatigue Life In Aluminum Alloy, Jin Hee Park

LSU Master's Theses

Corrosion-Prevention Compounds (CPC) are commonly used to prevent corrosion in the aircraft industry. The presence of corrosive environment (salt-fog, water-fog, even dry air) on aircraft structures has detrimental effects on the integrity of aircraft components which reduces the fatigue life and may accelerate the crack growth rate in the structures. This thesis work is aimed at identifying the effect of CPC and corrosion fatigue on the fatigue life of test specimen. This study describes the results of an experimental study on aluminum alloy 2024-T3 with center-crack specimen to investigate the effect of CPC on fatigue life. Generally, these compounds contain …


Color, Texture And Rehydration Characteristics Of Ohmically Treated Sweet Potatoes, Sireesha Bhattiprolu Jan 2004

Color, Texture And Rehydration Characteristics Of Ohmically Treated Sweet Potatoes, Sireesha Bhattiprolu

LSU Master's Theses

Ohmic heating has been shown to affect the drying rate and texture of foods. This research was designed to determine the effect of ohmic heating on rehydration, color and texture properties of sweet potatoes. Three combinations: 60Hz, 40V, 60Hz, 60V and 1Hz, 40V were applied to ohmically heat sweet potato cubes. The ohmic treated cubes and untreated cubes or controls were stored for six days in four different %relative humidities of 11.15%, 32.73%, 57.70% and 75.32%. Results showed that there was no significant difference in the rehydration properties of ohmic treated samples and control samples. The % moisture gain varied …


Testing A Cmos Operational Amplifier Circuit Using A Combination Of Oscillation And Iddq Test Methods, Pavan K. Alli Jan 2004

Testing A Cmos Operational Amplifier Circuit Using A Combination Of Oscillation And Iddq Test Methods, Pavan K. Alli

LSU Master's Theses

This work presents a case study, which attempts to improve the fault diagnosis and testability of the oscillation testing methodology applied to a typical two-stage CMOS operational amplifier. The proposed test method takes the advantage of good fault coverage through the use of a simple oscillation based test technique, which needs no test signal generation and combines it with quiescent supply current (IDDQ) testing to provide a fault confirmation. A built in current sensor (BICS), which introduces insignificant performance degradation of the circuit-under-test (CUT), has been utilized to monitor the power supply quiescent current changes in the CUT. The testability …