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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), …


Prediction Of Transient Head On Seepage Path Using Boundary Fitted Coordinate (Bfc) System, Sherly Hartono Jan 2002

Prediction Of Transient Head On Seepage Path Using Boundary Fitted Coordinate (Bfc) System, Sherly Hartono

LSU Master's Theses

One of the main causes of levee failure is seepage through levee. This seepage can cause weakening in the levee structure, which in turn can cause sudden levee failure or overtopping of the levee due to levee depression. The purpose of this study is to determine the transient head on the seepage path due to changing water level during flood period. Transient seepage problems are very important as critical condition can occur during this time rather than during steady state condition. Seepage path through a levee can be predicted using the Boundary Fitted Coordinate (BFC) system method. The physical coordinate …


A State-Of-The-Practice Review Of Hurricane Evacuation Plans And Policies, Elba Alicia Urbina Jan 2002

A State-Of-The-Practice Review Of Hurricane Evacuation Plans And Policies, Elba Alicia Urbina

LSU Master's Theses

The events of recent hurricane seasons have made evacuation one of the leading emergency management issues. In 1998 and 1999, Hurricanes Georges and Floyd precipitated the two largest evacuations in U.S. history and perhaps, its two largest traffic jams. In response to the problems experienced during these events, many State Department’s of Transportation (DOT) have begun to take a more active role in the planning, management, and operation of hurricane evacuations. Since the involvement of transportation professionals in the evacuation field has been a fairly recent development; many of the newest practices and policies have only been used once, if …


Extraction Of Physically-Realistic Pore Network Properties From Three-Dimensional Synchrotron Microtomography Images Of Unconsolidated Porous Media, Riyadh Ibrahim Al-Raoush Jan 2002

Extraction Of Physically-Realistic Pore Network Properties From Three-Dimensional Synchrotron Microtomography Images Of Unconsolidated Porous Media, Riyadh Ibrahim Al-Raoush

LSU Doctoral Dissertations

Algorithms were implemented to obtain high resolution three-dimensional images using synchrotron microtomography. Morphological algorithms were developed to extract physically-realistic pore-network structure from unconsolidated porous media systems imaged using synchrotron microtomography. The structure can be used to correlate pore-scale phenomena with the pore structure and can also be incorporated into a pore-network model to verify existing models, understand, or predict transport and flow processes and phenomena in complex porous media systems. The algorithms are based on the three-dimensional skeletonization of the pore space in the form of nodes connected to paths. Dilation algorithms were developed to generate inscribed spheres on the …


Cementitious Stabilization Of Soils In The Presence Of Sulfate, Lan Wang Jan 2002

Cementitious Stabilization Of Soils In The Presence Of Sulfate, Lan Wang

LSU Doctoral Dissertations

Winn Rock (anhydrite, CaSO4) comes from a quarry in Winn Parish in north Louisiana. Gravel from the quarry has been used extensively as a surface course on local parish and logging roads. Stabilization of these roads with Type I Portland cement followed by an overlay by asphaltic concrete sometimes resulted in heaving. The causes for heaving and possible solutions were investigated. In the laboratory 2" x 4" molds of Winn Rock containing soil were prepared and cured in water bath at 40°C, sealed plastic bag at room temperature, and air. Molds were prepared with 5% to 20% cementitious material. The …


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 …


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. …


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 …


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 …


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 …


A Variable Response Time Lag Module For Car Following Models Using Fuzzy Set Theory, Yilmaz Hatipkarasulu Jan 2002

A Variable Response Time Lag Module For Car Following Models Using Fuzzy Set Theory, Yilmaz Hatipkarasulu

LSU Doctoral Dissertations

Since the 1950s, car following phenomena have been studied and analyzed, resulting in various models and algorithms. In general, the car following process has been defined as a stimulus-response relationship in which the driver of the following vehicle reacts to the actions of the lead vehicle after a time lag. One of the fundamental assumptions that underlie car following theory is that the driver response time lag is always a constant value for the driver at all times, regardless of level of detail of the model. Assumption of a constant time lag value introduces a number of broad assumptions however, …


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 …


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 …


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 …


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) …


Development Of Trip Generation Models Of Hurricane Evacuation, Bing Mei Jan 2002

Development Of Trip Generation Models Of Hurricane Evacuation, Bing Mei

LSU Master's Theses

In this study, alternative trip generation models for hurricane evacuation movement were developed using logistic regression and neural networks. The southwest Louisiana post-Andrew survey data were used for model estimation, validation, and comparison. The performance of the alternative models was compared with each other as well as against that of an existing evacuation model, the PBS&J model, developed for the same area. The results showed that the models developed in this study displayed similar performance. It was also found that the models developed in this study performed better than the existing PBS&J model in predicting household evacuation trip generation for …


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 …


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 …


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 …


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 …