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LSU Master's Theses

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Articles 1291 - 1312 of 1312

Full-Text Articles in Engineering

Tapered Liga Mold Insert, Ryan Anthony Turner Jan 2002

Tapered Liga Mold Insert, Ryan Anthony Turner

LSU Master's Theses

The applications of microstructures produced by the LIGA process are useful in a broad range of fields including: microfluidics, heat transfer, and mechanics. The Microsystems Engineering Team at Louisiana State University has used the LIGA process as a foundation for the team’s productivity in these areas. Many advances in the processes involved in producing these microstructures have been made in the past increasing the efficiency of the entire process. A modified exposure technique in the lithography stage of the LIGA process is being developed to produce microstructures with a draft angle as opposed to the standard straight walled structures. Electroformed …

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Bayesian Updating Of Simulated Household Travel Survey Data For Small/Medium Metropolitan Areas, Sirisha Murthy Kothuri Jan 2002

Bayesian Updating Of Simulated Household Travel Survey Data For Small/Medium Metropolitan Areas, Sirisha Murthy Kothuri

LSU Master's Theses

This thesis tests an approach for generating simulated travel survey data that has local characteristics incorporated in it. Travel survey data are generally required for estimating and calibrating travel demand models for a region. The high cost associated with travel surveys puts them beyond the budget of most small/medium MPOs. Therefore simulation of travel survey data provides a viable alternative for these data starved regions to generate data. The simulated data is produced by combining socio-demographic data along with a national survey data set. Updating the simulated data distributions with the distributions obtained by surveying a small sample of local …

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Evaluation Of The Hydrocarbon Potential In Low-Salinity Shaly Sand, Fnu Kurniawan Jan 2002

Evaluation Of The Hydrocarbon Potential In Low-Salinity Shaly Sand, Fnu Kurniawan

LSU Master's Theses

This research utilizes reservoir data from an oilfield in Indonesia, which is characterized by shaly sand and low salinity formation water. Both low salinity and shaliness reduce the resistivity contrast between oil and water. The aim of this research was to build a comprehensive interpretation algorithm to evaluate the shaly-sand reservoir in a low salinity formation water using limited well log data. Shaly-sand interpretation is still evolving with numerous researchers conducting investigations of the clay minerals effect on rock conductivity through theoretical and experimental approach. These investigations can be loosely divided into either Fractional Shale Volume models or the Cation …

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Intrinsic Biodegradation Potential Of Crude Oil In Salt Marshes, Julius Enock Jan 2002

Intrinsic Biodegradation Potential Of Crude Oil In Salt Marshes, Julius Enock

LSU Master's Theses

Understanding the influence of different perturbations on the fate of spilled oil in marine ecosystems is useful in assessing the environmental impact and remedial investigation. The effect of flooding and spill recurrence on the fate of an experimental crude oil spill (2 L/m2) was investigated using salt marsh intact cores, incubated for about 3 months, by monitoring residual petroleum hydrocarbons, heterotrophic microbial activity (fluorescein diacetate assay) and soluble organic carbon (SOC). For the flooding study, biodegradation rate of crude oil (with half-lives varying between 16.50 and 49.51 days and turnover times between 23.81 and 71.43 days) and microbial …

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Visco-Elastic Creep In The Lumbar Spine Associated With Static Flexion: A Feline Model, Guntulu Selen Hatipkarasulu Jan 2002

Visco-Elastic Creep In The Lumbar Spine Associated With Static Flexion: A Feline Model, Guntulu Selen Hatipkarasulu

LSU Master's Theses

Musculoskeletal disorders (MSDs) have become a major health concern with the industrial revolution and technological advances. The National Institute for Occupational Safety and Health (NIOSH) recently estimated the cost of MSDs at $13 to $20 billion annually. Back, spine, and spinal cord disorders add up to 60% of the total MSD injuries. Based on pervious studies, it is known that lumbar ligaments play a limited or little role in stabilizing the spine; where as the musculature around the spine is the major stabilizing structure. However, repetitive or prolonged static displacement or load induces creep in passive tissues of the spine …

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Liga Mold Insert Fabrication Using Su-8 Photoresist, Jian Zhang Jan 2002

Liga Mold Insert Fabrication Using Su-8 Photoresist, Jian Zhang

LSU Master's Theses

The LIGA process potentially enables economic mass-production of devices with high aspect ratio geometry. Central to the LIGA process is the fabrication of high quality LIGA molds. But in the traditional LIGA mold insert fabrication process, the x-ray photoresist poly-methyl-methacrylate (PMMA) is not highly sensitive to x-rays and a thick piece of PMMA sheet (>1mm) needs too much time to get exposed (bottom dose: 3500J/cm3), which results in excessive cost/ fabrication difficulty of the mold insert. Thus, in this thesis a negative photoresist SU-8 was tested as an x-ray photoresist in the LIGA fabrication process. SU-8 is much more …

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A Screening Assessment Of Dissolved Air Flotation For Control Of Nonindigenous Invasive Species Transported In Shipping Ballast Water, Eng Chong Voon Jan 2002

A Screening Assessment Of Dissolved Air Flotation For Control Of Nonindigenous Invasive Species Transported In Shipping Ballast Water, Eng Chong Voon

LSU Master's Theses

Uncontrolled discharge of ballast water by vessels has been considered one of the main mechanisms for the introduction of aquatic nuisance species (ANS). The typical size of species found ranges from 0.02 to 10,000 micrometer. This wide range of sizes consists of microorganism (protozoa, dinoflagellates, and cholera), planktonic species, plants, insects, other arthropods, worms, mollusks, and vertebrates. These species either remain suspended in ballast water or settle in ballast tank sediments. Providing treatment for ballast water is a challenging task due to space availability of ships and significant magnitude of flow rates and volumes of ballast water. Currently, open ocean …

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Fecal Coliform Decay And Regrowth Kinetics In An Anaerobic Dairy Wastewater Environment, Shufang Liu Jan 2002

Fecal Coliform Decay And Regrowth Kinetics In An Anaerobic Dairy Wastewater Environment, Shufang Liu

LSU Master's Theses

The kinetics of fecal coliforms (FC) decay and regrowth were analyzed under laboratory conditions using filtered dairy wastewater under anaerobic conditions. The mean specific growth rates during the regrowth phase, µr , in the batch study were 1.79, 1.46, and 1.27d-1 for initial organic carbon concentrations of 478, 235 and 127 mg/L COD, respectively. The substrate concentrations had a significant impact on the FC regrowth. A maximum specific growth rate (mmax) of 1.92 d-1, and half-saturated coefficient (ks) of 60.92mg/L were determined from these data. The mean dark FC decay rate coefficients, kd , at 35oC in the batch study …

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Development Of Catalytic Processes For Aromatic Amides And Carboxylic Acids, Yujun Song Jan 2002

Development Of Catalytic Processes For Aromatic Amides And Carboxylic Acids, Yujun Song

LSU Master's Theses

New catalysts were prepared and studied for: (1) a model amidation with a hindered amine, diethylamine (DEA), to N,N¡¯-diethyltoluamide (DEET); (2) the oxidation of m-xylene (MX) to DEET¡¯s alkylaromatic precursor, m-toluic acid (MTA). In both cases the goal was to reduce waste associated with current processes. Thermodynamic analyses showed that the amidation to produce DEET from MTA and DEA was an equilibrium limited reaction with equilibrium constants (Ke) less than 41 at temperatures below 320¡ÆC. The kinetics on silica-supported titanium (¥³) (triethanolaminato)-isopropoxide (Tyzor TE), calcium hydroxyapatites and silica supported tungsten heteropolyacids were studied using a continuous reactor. Both porous hydroxyapatites …

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Geostatistical Shale Models For A Deltaic Reservoir Analog: From 3d Gpr Data To 3d Flow Modeling, Hongmei Li Jan 2002

Geostatistical Shale Models For A Deltaic Reservoir Analog: From 3d Gpr Data To 3d Flow Modeling, Hongmei Li

LSU Master's Theses

The effects of shales on fluid flow in marine-influenced lower delta-plain distributary channel deposits are investigated using a three-dimensional ground-penetrating radar (GPR) data volume from the Cretaceous-age Ferron sandstone at Corbula Gulch in central Utah, USA. Using interpreted GPR data, we formulate a geostatistical model of the dimensions, orientations, and geometries of the internal structure from the subaerial exposure surface down to about 12 m depth. The correlation function between GPR instantaneous amplitude and shale index is built after statistical calibration of the GPR attributes (amplitude) with well data (gamma ray logs). Shale statistics are computed from this correlation function. …

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Movement Along The Baton Rouge Fault, Araya Eshetu Kebede Jan 2002

Movement Along The Baton Rouge Fault, Araya Eshetu Kebede

LSU Master's Theses

The Baton Rouge fault is one of two faults (the other being Denham Spring-Scotlandville fault) that traverse the city of Baton Rouge and has long been thought to be active. Structural damages to buildings, streets and sidewalks near the fault have previously been attributed to movement of the fault. Although the presence of the fault has been known for nearly 60 years, previous investigations have failed to determine its rate of movement. This study was aimed at determining the rate of modern movement along the Baton Rouge fault. Using a precise geodetic leveling technique, the current elevations of NGS (National …

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Tension Lap Splice Lengths Of Carbon Fiber Reinforced Polymer Bars, Gregory Patrick Sepeda Jan 2002

Tension Lap Splice Lengths Of Carbon Fiber Reinforced Polymer Bars, Gregory Patrick Sepeda

LSU Master's Theses

With recent advances in the area of fiber reinforced polymers (FRP), more effort has been spent trying to incorporate the use of FRP in design applications. FRP bars offer both an ultimate strength and a corrosion resistance greater than traditional steel reinforcing. Fiber reinforced polymer bars can either consist of continuous glass (GFRP), aramid (AFRP) or carbon fibers (CFRP). CFRP bars, while lighter than GFRP typically offer a much greater tensile strength. With the recent release of the American Concrete Institute’s first edition manual ACI-440.1R “Guide for the Design and Construction of Concrete Reinforced with FRP Bars” (2001), unified design …

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A Model Of Heat And Mass Transfer In An Idealized Micro Heat Pipe, Jin Zhang Jan 2002

A Model Of Heat And Mass Transfer In An Idealized Micro Heat Pipe, Jin Zhang

LSU Master's Theses

Micro heat pipes have been used to cool computer chips, but their heat transfer coefficients are low compared with that of conventional heat pipes. To understand this deficiency, an idealized micro heat pipe is proposed that has simplified interfacial geometry but retains the essential physics. It is a long and narrow cavity of rectangular cross section with the bottom made of a wetting material and the top a non-wetting material. A wetting liquid fills the bottom half of the cavity, and its vapor fills the rest. This configuration ensures that the liquid-vapor interface is pinned at the contact line. Since …

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The Effect Of Initial Selections In Estimating The Missing Comparisons In An Incomplete Ahp Matrix, Sugeng Setiawan Jan 2002

The Effect Of Initial Selections In Estimating The Missing Comparisons In An Incomplete Ahp Matrix, Sugeng Setiawan

LSU Master's Theses

One of the most widely used methods in decision-making is the Analytic Hierarchy Process (AHP). With its technique of comparing the alternatives by means of a sequence of pairwise comparison matrices, the AHP is both easy to understand and very versatile. This research aims at contributing some insights on this method, in particular, regarding to what is known as the incomplete AHP. The core of this research is to investigate whether the initial comparisons used to extract the data for a multi-criteria decision making problem, will play a role in producing a relatively accurate estimation of the ranking of the …

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Sugar Cane Yield Monitoring System, Caryn Elizabeth Benjamin Jan 2002

Sugar Cane Yield Monitoring System, Caryn Elizabeth Benjamin

LSU Master's Theses

This project involved the design and testing of a sugar cane yield monitoring system during the 1999 and 2000-harvest seasons. The system was mounted on a CAMECO CH 2500 1997 sugar cane combine. The sugar cane yield monitoring system consisted of a scale, a data acquisition system, and a differential global positioning system (DGPS). The scale consisted of a weigh plate supported by load cell(s). The load cell(s) were supported by a protective box, which mounted to the frame of the harvester. The scale, which was mounted in the floor of the elevator, directly recorded instantaneous measurements of the sugar …

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Nonlinear State And Parameter Estimation And Model Predictive Control Of Nitrogen Purification Columns, Shoujun Bian Jan 2002

Nonlinear State And Parameter Estimation And Model Predictive Control Of Nitrogen Purification Columns, Shoujun Bian

LSU Master's Theses

High-purity distillation columns are highly nonlinear systems. Nonlinear Model Predictive Control of these columns is challenging. The complexity of a first-principles model of a multi-stage distillation column, which involves a large number of differential and algebraic equations, makes Model Predictive Control computationally expensive. This thesis has focused on Nonlinear Model Predictive Control based on a simplified wave model of a distillation column; the simplified wave model consists of only one ordinary differential equation along with several algebraic equations. The predictive capability of the nonlinear wave model can be improved significantly through the application of nonlinear state estimation. Off-line estimation by …

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Nitrification Rates In A Reversed-Flow, Spouted-Bed, Bioreactor Applied To Recirculating Aquaculture Systems, Jonathan Thomas Scott Jan 2002

Nitrification Rates In A Reversed-Flow, Spouted-Bed, Bioreactor Applied To Recirculating Aquaculture Systems, Jonathan Thomas Scott

LSU Master's Theses

The effects of media selection and organic loading on nitrification rates in a reversed-flow, three-phase, spouted-bed, bioreactor with draft-tube (A-1 Aquaculture Continuous-Cleaning Multifunctional Biofilter or CCMB) were studied. Experiments were conducted on three identical recirculating aquaculture systems (RAS) each having a CCMB unit with a unique plastic pelletized media and operated over five successive trials with varying components and operating conditions. Based upon organic loading, three of the five trials were grouped into two organic loading regimes of approximately 91 mg/L COD and 149 mg/L COD. Comparing nitrification rates against the three media types by organic loading showed that media …

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Polyurethane Foam Based Packing Media For Biofilters Removing Volatile Organic Compounds From Contaminated Air, Felipe A. Martinez Jan 2001

Polyurethane Foam Based Packing Media For Biofilters Removing Volatile Organic Compounds From Contaminated Air, Felipe A. Martinez

LSU Master's Theses

In recent years, biofiltration technology has gained acceptance worldwide as an economical and reliable air pollution control technology for treating gases contaminated by low concentrations of biodegradable volatile organic compounds (VOCs). Important applications include control of odors generated by wastewater treatment plants and control of VOC emissions from industrial sources. Although there have been many successful applications, several operational problems have been reported in the literature. These include difficulty in control over bed moisture content, high head loss caused by excessive biomass production, and inability to maintain removal efficiency during transient periods of high concentration loading. Use of a superior …

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Simulation Study And Instability Of Adaptive Control, Zhongshan Wu Jan 2001

Simulation Study And Instability Of Adaptive Control, Zhongshan Wu

LSU Master's Theses

The Minimum-degree Pole Placement algorithm for Self-tuning Regulator design and the Recursive Least-square method and the projection algorithm for plant estimation are studied first in this thesis. Simulation studies for the estimator and controller algorithms are mainly undertaken after describing how to use MATLAB S-function in detail. Not only do Simulation experiments illustrates how and how well the MDPP and RLS algorithms work, but also show how to write and debug MATLAB codes for S-function programs. The robustness of the adaptive control system is intensively discussed subsequently. By using an estimator resistant to the noise contamination, the adaptive control system …

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Multiple-Access Interference Suppression In Cdma Wireless Systems, Jianqiang He Jan 2001

Multiple-Access Interference Suppression In Cdma Wireless Systems, Jianqiang He

LSU Master's Theses

This thesis presents techniques that suppress the multiple access interference (MAI) in CDMA wireless systems. MAI is the main factor that influences the communication quality and the capacity in CDMA wireless systems. Hence the suppression of MAI is essential to the performance of a CDMA wireless system. For conventional CDMA systems where matched filters are used as receivers, the only MAI suppression method available is the power control, which allocates each user in the system an appropriate transmitter power level such that the transmitter power is minimized to decrease the MAI, while at the same time each user maintains a …

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Dynamic Scheduling, Allocation, And Compaction Scheme For Real-Time Tasks On Fpgas, Shobharani Tatineni Jan 2001

Dynamic Scheduling, Allocation, And Compaction Scheme For Real-Time Tasks On Fpgas, Shobharani Tatineni

LSU Master's Theses

Run-time reconfiguration (RTR) is a method of computing on reconfigurable logic, typically FPGAs, changing hardware configurations from phase to phase of a computation at run-time. Recent research has expanded from a focus on a single application at a time to encompass a view of the reconfigurable logic as a resource shared among multiple applications or users. In real-time system design, task deadlines play an important role. Real-time multi-tasking systems not only need to support sharing of the resources in space, but also need to guarantee execution of the tasks. At the operating system level, sharing logic gates, wires, and I/O …

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Electrodeposition Of Niw Alloys Into Deep Recesses, Lakshmikanth Namburi Jan 2001

Electrodeposition Of Niw Alloys Into Deep Recesses, Lakshmikanth Namburi

LSU Master's Theses

Pulse electrodeposition has been investigated as a general technique for the electrodeposition of nickel-tungsten alloys in deep recesses for MEMS. Ni-W exhibits an induced codeposition mechanism, where the Ni reaction rate enhances the codeposition of W. Electrodeposition of this alloy has been achieved into recesses of 500 micron deep. The challenges that have been encountered are those related to gas evolving side reactions, local pH rises, diffusional limitations of the soluble species and long times required for filling the recesses. Electrodeposition on cylinder electrodes at different rotation rates was also carried out in order to obtain data on composition of …

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