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Full-Text Articles in Engineering

Hard Surface Coating Experimental Evaluation And Thermomechanical Analysis Of A Seal With Micro Heat Exchanger, Yifan Qiu Jan 2002

Hard Surface Coating Experimental Evaluation And Thermomechanical Analysis Of A Seal With Micro Heat Exchanger, Yifan Qiu

LSU Master's Theses

Mechanical face seals are important components of many rotating machinery. Minimizing the friction between seal faces and efficiently removing the heat generated between seal surfaces are two crucial considerations in the design of mechanical seal. Thin film coating and MEMS technology hold great promise for improving the performance of mechanical seals from the viewpoint of reducing friction and heat at the interface in these two aspects. To reveal what effect the coating and MEMS technology can have on tribological properties of seals, friction and wear characteristics of Ti-C:H coatings on seal-like rings and heat transfer performances of a seal prototype …


Development Of A Phosphorus Management Model To Address Filamentous Algae In A Shallow, Subtropical, Urban Hypereutrophic Lake, Jennifer Eileen Ruley Jan 2002

Development Of A Phosphorus Management Model To Address Filamentous Algae In A Shallow, Subtropical, Urban Hypereutrophic Lake, Jennifer Eileen Ruley

LSU Master's Theses

City Park Lake is a shallow, subtropical, urban hypereutrophic lake located in Baton Rouge, Louisiana. By the late 1970’s, this artificial lake had experienced extreme eutrophication and suffered from frequent algal blooms and fish kills. Restoration of City Park Lake occurred in 1983 and consisted of dredging nutrient-laden sediments and the rehabilitation of sewage pipelines. Pre- and post-restoration water quality monitoring programs have provided valuable information by which to gage the long-term success of the restoration work. Following the restoration effort, dramatic improvements were observed in the lake including lower nitrogen, phosphorus and chlorophyll-a concentrations, reduced frequencies in algal blooms …


Quantification Of The Spatial Gradient Of Local Volume Fraction From Tomography Images, Yongping Wang Jan 2002

Quantification Of The Spatial Gradient Of Local Volume Fraction From Tomography Images, Yongping Wang

LSU Master's Theses

Asphalt concrete has three constituents: aggregate, asphalt binder and air voids. In the mixture, aggregates serve as a skeleton of the mixture; asphalt serves as a binder to hold the aggregates together; and air voids prevent asphalt concrete from bleeding to avoid plastic mixes. The properties of asphalt concrete are controlled by the interaction of these three components. In asphalt concrete, asphalt binder, voids and aggregates are not uniformly distributed. The local volume fractions of these constituents vary with spatial locations. As a result, there exist a spatial gradient of the local volume fractions between two locations. Due to the …


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 …


The Interaction Between Hydrology And Water Quality For Urban Rainfall-Runoff: Implications For Management Strategies, Christopher Michael Dean Jan 2002

The Interaction Between Hydrology And Water Quality For Urban Rainfall-Runoff: Implications For Management Strategies, Christopher Michael Dean

LSU Master's Theses

In urban environments, anthropogenic activity deposits potentially hazardous residuals onto impervious surfaces. To investigate the process of wet-weather constituent transport, twelve rainfall/runoff events collected at an experimental catchment site in Baton Rouge, Louisiana were analyzed for temporal delivery of aggregate constituents (SSC, COD, TDS) as well as dissolved and particulate-bound metal concentrations (Cd, Cu, Pb and Zn). Event mean concentrations for the parameters analyzed often exceeded USEPA discharge limits. Rainfall-runoff events were characterized as either mass-limited or flow-limited. Events designated as mass-limited exhibited a high runoff volume, low vehicle to volume ratio (VPV), high stream power and a low correlation …


A Correlation Between The Optical And Mechanical Properties Of Novel Polysilane/Polysiloxane Nanocomposites, Sungho Lee Jan 2002

A Correlation Between The Optical And Mechanical Properties Of Novel Polysilane/Polysiloxane Nanocomposites, Sungho Lee

LSU Master's Theses

Polysilanes are ¥ò-conjugated conductive polymers with a one-dimensional Si backbone and organic substituted side chains. The conventional Wurtz-type coupling reaction has been used for preparing various alkyl substituted polysilanes, i.e. poly(di-n-hexyl)silane and poly(hexylmethyl)silane. For each polysilane examples with methoxy (-OCH3) and allyl (-CH2CH=CH2) end caps have been prepared. The solution UV absorption characteristics of the polysilanes at room temperature have been measured, from which the wavelength maximum of the UV-VIS absorption and the absorptivity have been obtained. Allyl end capped polysilanes have the same wavelength maximum as methoxy end capped polysilanes. However, the absorptivities of allyl end capped polysilanes are …


Computing Moments Of A Binary Horizontally/Vertically Convex Image Using Run-Time Reconfiguration, Cheowway Neoh Jan 2002

Computing Moments Of A Binary Horizontally/Vertically Convex Image Using Run-Time Reconfiguration, Cheowway Neoh

LSU Master's Theses

In this thesis, we present a design for computing moments of a binary horizontally/vertically convex image on an FPGA chip, using run-time reconfiguration. We compute the moments of up to third order for a total of 16 moments. We address how run-time reconfiguration speeds up moment computations without taking up huge hardware resources. Since we are considering a binary horizontally/vertically convex image, we look at an alternative method in moment computations that utilizes constant coefficient multipliers. We divide the image into segments and process one segment at a time. We reconfigure the constant coefficient multipliers before processing the next segment. …


Buckling Analysis Of Grid Stiffened Composite Structures, Samuel Kidane Jan 2002

Buckling Analysis Of Grid Stiffened Composite Structures, Samuel Kidane

LSU Master's Theses

Buckling of a stiffened composite cylinder is a very complex phenomenon that involves complex interactions between the skin and the stiffeners. Depending on different configurations of the skin and stiffener, different buckling failure modes and failure loads are observed in stiffened cylinders. In this work failure modes and buckling loads of stiffened composite cylinders under uniaxial loading condition is investigated by using analytical and experimental approaches. In the first Chapter an improved smeared method is developed to model the buckling problem of an isogird stiffened composite cylinder. In this model the stiffness contributions of the stiffeners is computed by analyzing …


Enhanced Bioremediation Of 1,1,2,2-Tetrachloroethane In Wetland Soils, Jason S. House Jan 2002

Enhanced Bioremediation Of 1,1,2,2-Tetrachloroethane In Wetland Soils, Jason S. House

LSU Master's Theses

This research investigated the capability of wetland soils to function as a medium for the degradation of 1,1,2,2-TeCA and its daughter products, and the influence of different hydrogen donors and nutrients on this process. The rate constants calculated for this study, show that removal of 1,1,2,2-TeCA is occurring in the microcosms receiving hydrogen donors as well as the biotic controls. The parent compound was undergoing complete degradation to ethene, which was confirmed by ethene analysis, as well as monitoring the intermediate compounds. The analysis for the degradation products of 1,1,2,2-tetrachloroethene is important in determining the overall potential for successful degradation …


Fine Aggregate Characterization Using Digital Image Analysis, Tongyan Pan Jan 2002

Fine Aggregate Characterization Using Digital Image Analysis, Tongyan Pan

LSU Master's Theses

A comprehensive literature review shows that performance of hot mix asphalt (HMA) is influenced by properties of aggregate. Current situation is that only limited efforts were dedicated to aggregate tests and criteria on aggregate, compared to researches on new binder tests, especially to that of fine aggregate. Superpave (Superior Performing Asphalt Pavement) tests/criteria on aggregate need to reflect those properties that influence performance. Representatives of the aggregate industry and the Superpave Mixture/Aggregate ETG (Expert Task Group) have reached the consensus for the need to improve aggregate tests and criteria as one of the most needed aspects left to complete in …


Parametric And Sensitivity Analysis Of A Vibratory Automobile Model, Kanika Nicole Vessel Jan 2002

Parametric And Sensitivity Analysis Of A Vibratory Automobile Model, Kanika Nicole Vessel

LSU Master's Theses

Vibration response is an important aspect of any engineering problem. This thesis deals with developing a method to obtain the vibration, parametric and sensitivity of an automobile analyzed as a 2-DOF rigid body system with damping. The focus of the vibration analysis is to obtain the poles, eigenvectors, and natural frequencies of the system. The parametric analysis gave information on how the natural frequency is affected when one of the parameters is perturbed. Information about how much the system is affected by the change in one parameter is what is obtained from the sensitivity analysis. The theoretical solution contained in …


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 …


Analysis Of Methods For Assigning Capacity In A Transportation Planning Network, Yogesh Kandaswamy Dheenadayalu Jan 2002

Analysis Of Methods For Assigning Capacity In A Transportation Planning Network, Yogesh Kandaswamy Dheenadayalu

LSU Master's Theses

The objective of the research was to analyze the current practice of assigning capacity values to links of a network and to determine how capacity can be assigned more accurately without greatly increasing time, effort and costs. Currently in most planning networks, the link capacities are assigned based on the number of lanes and a gross facility and area type considerations (LSU, 1997). This practice might have affected the results of travel demand modeling performed using the network. To test this hypothesis, the current practice was compared to the practice of assigning capacities link-by-link using the Highway Capacity Manual (HCM) …


Tribological Behavior Of Nanostructured Nickel, Dean Joseph Guidry Jan 2002

Tribological Behavior Of Nanostructured Nickel, Dean Joseph Guidry

LSU Master's Theses

The present study reports the effects of electroplating parameters on the microstructure, and thus the mechanical and tribological properties, of nanostructured nickel. Electroplating was conducted in a Watt's type bath with a pH of 3.0 carried out using direct current in galvanostatic mode at current densities of 30 mA/cm2 and 15 mA/cm2 in electroplating bath temperatures of 30°C and 50°C. Grain size and distributions were determined from TEM (Transmission Electron Microscope) and SEM (Scanning Electron Microscope) micrographs. Tribological tests were carried out on a pin-on-disc type tribometer. The same tests were conducted on Ni-200 for the purpose of …


Transient Thermomechanical Interactions Of Shaft-Bushing Pair In Bearings - A Finite Element Study, Rajesh Krithivasan Jan 2002

Transient Thermomechanical Interactions Of Shaft-Bushing Pair In Bearings - A Finite Element Study, Rajesh Krithivasan

LSU Master's Theses

This thesis presents a finite element parametric study of the transient thermomechanical interactions of shaft-bushing pairs in bearings to gain insight into the nature of two categories of failures encountered in practice. The first type of failure deals with occurrence of the so-called thermally induced seizure (TIS) during the start-up period followed by an investigation of TIS due to a transient flow-disturbance. The second part deals with the thermomechanical interactions of pin-bushing assembly under heavy oscillating loads where the failure is by TIS and/or thermal galling. An extensive set of parametric simulations covering a wide range of loads, speeds, operating …


Bench-Scale Compost Reactors System And The Self-Heating Capabilities, Michael Alden Vining Jan 2002

Bench-Scale Compost Reactors System And The Self-Heating Capabilities, Michael Alden Vining

LSU Master's Theses

Less expensive bench-scale composting reactor systems which can mimic actual composting process via self-heating are needed. One can achieve such systems without using the expensive temperature feed-back control by properly insulating the bench composting reactors. However, the knowledge of heat generation and transfer in bench composting reactors is essential in properly designing such inexpensive insulation systems. All compost trial temperature profiles illustrated initial elevated temperature levels followed by a slow gradual temperature decreasing phase. Of all of the variables, the airflow rate, the volume and the overall heat transfer coefficient, seem to have the greatest impact on producing thermophilic temperatures. …


Wastewater Plume Dynamics And Bacteria Transport Within The Marshland Upwelling System, Stephen David Richardson Jan 2002

Wastewater Plume Dynamics And Bacteria Transport Within The Marshland Upwelling System, Stephen David Richardson

LSU Master's Theses

The marshland upwelling system (MUS) serves as an alternative onsite method for the treatment of domestic wastewater derived from coastal communities. Previous studies on the MUS have focused on the efficacy of the system for the removal of fecal pathogens from settled and secondarily-treated wastewater sources. The objectives of this research were to: 1) characterize the extent of wastewater migration within the MUS, 2) evaluate the effectiveness of the MUS in removing fecal bacteria, 3) identify the mechanisms responsible for fecal coliform retention within the subsurface, and 4) describe the transport of fecal coliforms in a sand media based on …


Non-Linear Kinematic Hardening Model For Multiaxial Cyclic Plasticity, Marcio Costa Araujo Jan 2002

Non-Linear Kinematic Hardening Model For Multiaxial Cyclic Plasticity, Marcio Costa Araujo

LSU Master's Theses

A model of kinematic work hardening based on Frederick and Armstrong (1966), Phillips and Weng (1975), Chaboche (1979), and Voyiadjis and Basuroychowdhury (1998) is proposed for metal like behavior materials. In this proposed model, ratcheting is taken into account through the observation of the backstress evolution equation, modified by the addition of a new term, . Experimental observations made by Phillips and Lee (1979) showed that the direction of the movement of the center of the yield surface occurs in between the stress rate tensor and the plastic strain rate tensor directions. The new term, added to Chaboche model (1979), …


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 …


Surfactant-Induced Relative Permeability Modifications For Oil Recovery Enhancement, Subhash C. Ayirala Jan 2002

Surfactant-Induced Relative Permeability Modifications For Oil Recovery Enhancement, Subhash C. Ayirala

LSU Master's Theses

Surfactants have been considered for enhanced oil recovery by reduced oil-water interfacial tension. However, these surfactants may enhance oil recovery via wettability alteration as well. This study experimentally determines the influence of surfactant type and concentration on oil recovery, oil-water relative permeabilities and wettability in reservoir rocks. Several coreflood experiments were conducted using Yates reservoir fluids in Berea rocks and two types of surfactants (nonionic and anionic) in varying concentrations. A coreflood simulator was used to calculate oil-water relative permeabilities by history matching recovery and pressure drop measured during the corefloods. These relative permeability variations were interpreted using Craig's rules-of-thumb …


Offline And Online Variants Of The Traveling Salesman Problem, John Ebenezer Augustine Jan 2002

Offline And Online Variants Of The Traveling Salesman Problem, John Ebenezer Augustine

LSU Master's Theses

In this thesis, we study several well-motivated variants of the Traveling Salesman Problem (TSP). First, we consider makespan minimization for vehicle scheduling problems on trees with release and handling times. 2-approximation algorithms were known for several variants of the single vehicle problem on a path. A 3/2-approximation algorithm was known for the single vehicle problem on a path where there is a fixed starting point and the vehicle must return to the starting point upon completion. Karuno, Nagamochi and Ibaraki give a 2-approximation algorithm for the single vehicle problem on trees. We develop a Polynomial Time Approximation Scheme (PTAS) for …


Effect Of Tip Geometry On Blade Tip Flow And Heat Transfer, David Michael Kontrovitz Jan 2002

Effect Of Tip Geometry On Blade Tip Flow And Heat Transfer, David Michael Kontrovitz

LSU Master's Theses

In an attempt to increase thrust to weight ratio and efficiency of modern gas turbines, engine designers are always interested in increasing turbine operating temperatures. The benefits are attributed to the fact that higher temperature gases yield a higher energy potential. However, the detrimental effects on the components along the hot gas path can offset the benefits of increasing the operating temperature. The High Pressure Turbine (HPT) first stage blade is one component that is extremely vulnerable to the hot gas. The present study explores the effects of gap height and tip geometry on heat transfer distribution. This investigation differs …


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 …


Fecal Coliform Concentration In Surface Runoff From Pastures With Applied Dairy Manure, Alyson Kristine Bertges Hubbs Jan 2002

Fecal Coliform Concentration In Surface Runoff From Pastures With Applied Dairy Manure, Alyson Kristine Bertges Hubbs

LSU Master's Theses

This study examined the magnitude of release of fecal coliform indicator bacteria in surface runoff from pasture amended with dairy manure. The experiment was conducted at Southeast Research Station in Franklinton, Louisiana between March and June, 2001. The experiment was designed to compare the effects of two methods of manure application on fecal coliform release. Manure application simulating natural deposition by cattle (Treatment A) was compared to that of land application of manure as fertilizer (Treatment B). Application of inorganic fertilizer was used as the control. Each Treatment was applied to three field plots. Simulated rainfalls were conducted on plots …


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 …


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 …


Development Of A Magnetite Tracer Protocol For Seasonal Measurement Of Bed Sediment Biodiffusion Coefficients, Paul D. Libbers Jan 2002

Development Of A Magnetite Tracer Protocol For Seasonal Measurement Of Bed Sediment Biodiffusion Coefficients, Paul D. Libbers

LSU Master's Theses

This thesis describes the development of a particle tracer technique for making short-term, in situ measurements of aquatic bed sediment biodiffusion coefficients. The bioturbation process in the upper sediment layers of streams, lakes, estuaries, and the marine environment moves particles and porewater. When present, organic chemicals, metals, colloids, etc., are transported across these layers and exchanges may occur at the sediment-water interface. Fickian biodiffusion coefficients that characterize such particle movements, Db (cm2/yr), are used for assessing chemical diagenesis rates and contaminant fluxes and are specific to each site. Chemical Fate and Transport (CFaT) models, developed for tracking contaminants in aquatic …


Water-Drive Gas Reservoir: Sensitivity Analysis And Simplified Prediction, Junpeng Yue Jan 2002

Water-Drive Gas Reservoir: Sensitivity Analysis And Simplified Prediction, Junpeng Yue

LSU Master's Theses

Water influx and well completions affect recovery from water-drive gas reservoir. Material balance, aquifer models and well inflow equations are used to examine and predict the pressure depletion, water influx, and production rates of water-drive gas reservoirs. The parameters of these simple, lumped models are estimated from simulation results using response surfaces and experimental designs for eight varying geologic and engineering factors. Eleven simulated responses (including maximum gas rate, aquifer and well constants, and water breakthrough) are analyzed using ANOVA and response models. A sensitivity analysis of aquifer productivity index, gas production factor, and sweep efficiency reveals that permeability is …


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 …


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 …