Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Civil and Environmental Engineering

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 7981 - 8010 of 10558

Full-Text Articles in Entire DC Network

Biological Reduction Of Perchlorate In Ion Exchange Regenerant Solutions Containing High Salinity And Ammonium Levels, Tina M. Gingras, Jacimaria R. Batista Jan 2002

Biological Reduction Of Perchlorate In Ion Exchange Regenerant Solutions Containing High Salinity And Ammonium Levels, Tina M. Gingras, Jacimaria R. Batista

Civil and Environmental Engineering and Construction Faculty Research

The most promising technologies to remove perchlorate from water are ion exchange and biological reduction. Although successful, ion exchange only separates perchlorate from water; it does not eliminate it from the environment. The waste streams from these systems contain the caustic or saline regenerant solutions used in the process as well as high levels of perchlorate. Biological reduction could be used to treat the regenerant waste solutions from the ion exchange process. A treatment scheme, combining ion exchange and biodegradation, is proposed to completely remove perchlorate from the environment. Perchlorate-laden resins generate brines containing salt concentrations up to 6% or …


Evolutionary Algorithms For Multiobjective Evaluation Of Watershed Management Decisions, Misgana K. Muleta, John W. Nicklow Jan 2002

Evolutionary Algorithms For Multiobjective Evaluation Of Watershed Management Decisions, Misgana K. Muleta, John W. Nicklow

Civil and Environmental Engineering

The comprehensive and systematic management of watersheds is essential for reducing the adverse environmental impacts arising from anthropogenically caused erosion and subsequent sedimentation. This paper describes a computational methodology that is designed to serve as a watershed decision support system and is capable of controlling environmental impacts of non-point source pollution resulting from erosion. In the decision process, the methodology also accounts for other inseparable objectives such as economics and social dynamics of the watershed. This decision support tool was developed by integrating a comprehensive hydrologic model known as SWAT and state-of-the-art multiobjective optimization technique within the framework of a …


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 …


Performance-Related Specifications For Concrete Bridge Superstructures, Volume 2: High-Performance Concrete, J. Olek, Aijsing Lu, Xiuping Feng, Bryan Magee Jan 2002

Performance-Related Specifications For Concrete Bridge Superstructures, Volume 2: High-Performance Concrete, J. Olek, Aijsing Lu, Xiuping Feng, Bryan Magee

JTRP Technical Reports

This is Volume 2 of the Final Report for the project titled “Performance-Related Specifications for Concrete-Bridge Superstructures” dealing with the topic of High-Performance Concrete (HPC). The investigation of high-performance concrete included the development of optimized concrete mixtures and identifying their performance characteristics related to durability for the purpose of using these characteristics in performance–related specifications in the state of Indiana. The research effort described in this report was divided in two phases. Phase I was focused on development of concrete mixtures optimized with respect to selected performance-related parameters. During this phase, ten optimum concrete mixes have been identified from 45 …


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 …


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), …


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 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 …


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 …


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, …


Optimal Placement Of Dampers And Actuators Based On Stochastic Approach, Franklin Y. Cheng, Hongping Jiang, Xiaozhe Zhang Jan 2002

Optimal Placement Of Dampers And Actuators Based On Stochastic Approach, Franklin Y. Cheng, Hongping Jiang, Xiaozhe Zhang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A general method is developed for optimal application of dampers and actuators by installing them at optimal location on seismic-resistant structures. The study includes development of a statistical criterion, formulation of a general optimization problem and establishment of a solution procedure. Numerical analysis of the seismic response in time-history of controlled structures is used to verify the proposed method for optimal device application and to demonstrate the effectiveness of seismic response control with optimal device location. This study shows that the proposed method for the optimal device application is simple and general, and that the optimally applied dampers and actuators …


Impact Of Land Use Change On Hydroelectric Power Generation In Cameron Highlands, Fook Kun Choy Jan 2002

Impact Of Land Use Change On Hydroelectric Power Generation In Cameron Highlands, Fook Kun Choy

Student Works (2000-2009)

This study assesses the impact of land use changes on annual energy production of the hydro stations of Cameron Highlands Hydroelectric Scheme. Land use affects sediment load and streamflow of Sungai Telom and Sungai Bertam, which influences power generation and energy production of the several hydro stations in Cameron Highlands. Data of rainfall, streamflow, suspended sediment load, land use and energy output for the period 1964 to 1998 were collected, processed and analysed. Regression analysis, double mass curve method and double ratio technique were used in the assessment. The suspended sediment load and annual runoff of Sungai Telom and Sungai …


Noise Control And Speech Intelligibility Improvement Of A Toll Plaza, Luc Mongeau, Robert J. Bernhard, Jeffery P. Feist Jan 2002

Noise Control And Speech Intelligibility Improvement Of A Toll Plaza, Luc Mongeau, Robert J. Bernhard, Jeffery P. Feist

JTRP Technical Reports

Vehicular toll roads are one component of many municipal transportation systems. Open communication windows, often used in tollbooths, facilitate essential communication and monetary transactions. However, the vehicle noise generated outside the booth is easily transmitted into the booth via the open window. Personnel working at toll collection plazas are exposed to extended, continuous traffic noise. Sustained noise levels of this nature may cause hearing loss, induce fatigue or stress, and reduce worker productivity. The annoyance and discomfort related to continuous noise exposure may create an unpleasant working condition and may affect the hospitality of the tollbooth operators and their attitude …


Performance-Related Specifications For Concrete Bridge Superstructures, Volume 1: Performance Parameters And Related Procedure For Concrete Bridge Superstructures, J. A. Ramirez, Jhon Paul Smith Jan 2002

Performance-Related Specifications For Concrete Bridge Superstructures, Volume 1: Performance Parameters And Related Procedure For Concrete Bridge Superstructures, J. A. Ramirez, Jhon Paul Smith

JTRP Technical Reports

In Volume 1 of the final report, the identification of performance levels and parameters, and the development of acceptance criteria, have been addressed. Emphasis has been placed on the development of a methodology for a Performance Related Specification, PRS, for concrete bridge superstructures. The implementation of the methodology, presented in the form of a user-friendly computer program, is project specific. It requires the mean and standard deviation (or definition of a probability distribution) of the input parameters for the performance predictive models. This is done for both the as-designed condition and the as-built condition of the structure. The contractor is …


Performance-Related Specifications For Concrete Bridge Superstructures, Volume 4: Bond Of Epoxy-Coated Bars With Thicker Coatings, J. A. Ramirez, Michael K. Appelhans Jan 2002

Performance-Related Specifications For Concrete Bridge Superstructures, Volume 4: Bond Of Epoxy-Coated Bars With Thicker Coatings, J. A. Ramirez, Michael K. Appelhans

JTRP Technical Reports

In Volume 4 of the final report, the results of an evaluation of the bond performance of epoxy-coated bars with a coating thickness up to 18 mils are presented. The experimental work on the bond performance of epoxy-coated bars with thickness up to 18 mils indicates that the current AASHTO requirements for development length of epoxy-coated bars up to #8 could be safely extended to coating thickness of up to 18 mils. Thus, no change to the bond specifications is recommended in order to implement the use of bars with diameters up to a #8 with epoxy-coating thickness up to …


Performance-Related Specifications For Concrete Bridge Superstructures, Volume 3: Nonmetallic Reinforcement, Robert J. Frosch, Christopher P. Mosley, Ahmet Koray Tureyen Jan 2002

Performance-Related Specifications For Concrete Bridge Superstructures, Volume 3: Nonmetallic Reinforcement, Robert J. Frosch, Christopher P. Mosley, Ahmet Koray Tureyen

JTRP Technical Reports

In Volume 3 of the final report, research work conducted to investigate the behavior of fiber reinforced polymer (FRP) reinforcement is summarized. This study focused on the behavior of FRP reinforced concrete structures with an emphasis on bond and shear. For the bond investigation, three series of beam splice tests were performed on specimens reinforced with steel, glass FRP, and aramid FRP to determine the effect of the different types of reinforcement on bond, cracking, and deflections. The test results indicate that the use of FRP reinforcement leads to lower bond strengths and, therefore, require longer development lengths. The specimen …


Diet Of Shovelnose Sturgeon Downstream From Gavins Point Dam: Final Report, Charles R. Berry Jr. Jan 2002

Diet Of Shovelnose Sturgeon Downstream From Gavins Point Dam: Final Report, Charles R. Berry Jr.

United States Army Corps of Engineers, Omaha District

The diet of shovelnose sturgeon (Scaphirhynchus platorhynchus) in the Missouri River downstream from Gavins Point Dam was characterized in 1993 (N=100 fish) and 1994 (N=103 fish) for comparison with similar data collected in 1971-72 (N=130 fish) by Modde and Schmulbach (1977, hereafter Modde). The primary difference among years in the South Dakota studies was river discharge, which was low in 1993 (9-22 kcfs; kcfs=thousand cubic feet per second), moderate in 1994 (18-31 kcfs), and high in 1971-72 (26-49 kcfs). We compared sturgeon diet weight and the weight of benthic and drifting invertebrates among years, among monthly discharges in …


Biological Fixed Film Systems, Mark W. Fitch, Ellen England Jan 2002

Biological Fixed Film Systems, Mark W. Fitch, Ellen England

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.


Using Transition Probability Geostatistics With Modflow, Norman L. Jones, J. R. Walker, S. F. Carle Jan 2002

Using Transition Probability Geostatistics With Modflow, Norman L. Jones, J. R. Walker, S. F. Carle

Faculty Publications

This paper describes a technique for applying the transition probability geostatistics method for stochastic simulation to a MODFLOW model. Transition probability geostatistics has several advantages over traditional indicator kriging methods, including a simpler and more intuitive framework for interpreting geological relationships and the ability to simulate juxtapositional tendencies such s fining-upwards sequences. The indicator arrays generated by the transition probability simulation are converted to layer elevation and thickness arrays for use with the new Hydrogeologic Unit Flow (HUF) package in MODFLOW 2000. This makes it possible to preserve complex heterogeneity while using reasonably sized grids.


Mass Transfer Reactions And Decay Sinks For Disinfectants In Water Distribution Systems, Jeremy B. Jones Jan 2002

Mass Transfer Reactions And Decay Sinks For Disinfectants In Water Distribution Systems, Jeremy B. Jones

Civil & Environmental Engineering Theses & Dissertations

Treatment plants utilize chlorine and chloramine both as a primary disinfectant for water purification and a secondary disinfectant for distribution system protection. The treatment goal is that the disinfectant residual be present throughout the distribution system until it reaches the customer's tap. Maintaining a residual throughout the system is critical for providing pathogen-free water and protecting human health. Therefore, water utility authorities are very interested in how disinfectants such as chlorine and chloramine decay as they travel through a water distribution system.

Current mathematical models typically divide the decay into two distinct phases. There is (1) decay occurring in the …


Multiple Objective And Span Evaluation Method For Damage Grade Of Existing Reinforced Concrete Bridges, Ming-Te Liang, Heng-Dong Wang, Jai-He Wu Dec 2001

Multiple Objective And Span Evaluation Method For Damage Grade Of Existing Reinforced Concrete Bridges, Ming-Te Liang, Heng-Dong Wang, Jai-He Wu

Journal of Marine Science and Technology–Taiwan

The principal purpose of this paper was to investigate the evaluation method of performance for existing reinforced concrete bridges. The least squares technique in classical mathematics was adopted firmly to establish both the multiple objective weight distribution method and multiple span level weight method. Thus, the multiple objective and span evaluation method were built for estimating the performance of existing reinforced concrete bridges. The evaluation model may be divided into grades I, II, III and IV which are described as non-damage, light damage, severe damage and unfit for service, respectively. Using the proposed model, the Huey-tong bridge, Jzyhchyang bridge, Ay-gow …


Lower Willamette River Model: Model Calibration, Chris Berger, Robert Leslie Annear, Scott A. Wells Dec 2001

Lower Willamette River Model: Model Calibration, Chris Berger, Robert Leslie Annear, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

Water Environment Services of Clackamas County is in the process of planning upgrades on several of its wastewater treatment plants (WWTPs) which discharge into the Lower Willamette River. The goals of the modeling effort were to:

• Gather data to construct a computer simulation model of the Lower Willamette River system in order to evaluate the impact of the WWTP discharges on water quality

• Ensure that the model accurately represents the system physics and chemistry (flow, temperature, dissolved oxygen and nutrient dynamics) by model calibration

• Use the model to evaluate how to meet various future discharge scenarios for …


Lower Willamette River Model: Boundary Conditions And Model Setup, Herman G. Rodriguez, Robert Leslie Annear, Scott A. Wells, Chris Berger Nov 2001

Lower Willamette River Model: Boundary Conditions And Model Setup, Herman G. Rodriguez, Robert Leslie Annear, Scott A. Wells, Chris Berger

Civil and Environmental Engineering Faculty Publications and Presentations

Water Environment Services of Clackamas County is in the process of planning upgrades on several of its sewage treatment plants which discharge into the Lower Willamette River. The goals of the modeling effort are to:

• Gather data to construct a computer simulation model of the Lower Willamette River system including part of the Lower Columbia River and the Willamette River above the Oregon City Falls; Because of the tidal influence in the Lower Willamette River, portions of the Columbia River that might affect the Lower Willamette River water quality were also modeled. Also, a section of the Willamette River …


Upper Spokane River Model: Boundary Conditions And Model Setup, 1991 And 2000, Robert Leslie Annear, Chris Berger, Scott A. Wells Nov 2001

Upper Spokane River Model: Boundary Conditions And Model Setup, 1991 And 2000, Robert Leslie Annear, Chris Berger, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

The Washington Department of Ecology is interested in a water quality model for the Upper Spokane River system for use in developing Total Maximum Daily Loads (TMDLs). The goals of this modeling effort are to:

• Gather data to construct a computer simulation model of the Spokane River system including Long Lake Reservoir and the pools behind Nine Mile dam, Upper Falls dam and Upriver dam

• Ensure that the model accurately represents the system hydrodynamics and water quality (flow, temperature, dissolved oxygen and nutrient dynamics)

A hydrodynamic and water quality model, CE-QUAL-W2 Version 3 (Wells, 1997), is being applied …


Experimental Investigation Of Moisture Migration In Concrete, R. P. West, Niall Holmes Sep 2001

Experimental Investigation Of Moisture Migration In Concrete, R. P. West, Niall Holmes

Conference papers

The ability to be able to predict the state of dryness of a concrete floor slab is a practical need in the construction industry. Current popular methods, including the surface hygrometer and vapour emission tests, only indicate surface dryness, with consequent uncertainties in the quantity of residual moisture deep within the slab. This paper describes the variation in moisture condition with depth for a number of slabs under different drying conditions, as established using a new probe which can reliably determine the relative humidity at any depth. From this it is concluded that results from the conventional tests need to …


Watershed Management Technique To Control Sediment Yield In Agriculturally Dominated Areas, John W. Nicklow, Misgana K. Muleta Sep 2001

Watershed Management Technique To Control Sediment Yield In Agriculturally Dominated Areas, John W. Nicklow, Misgana K. Muleta

Civil and Environmental Engineering

Non-point source pollution is recognized internationally as a critical environmental problem. In Illinois, soil erosion from agricultural lands is the major source of such pollution. The erosion process, which has been accelerated by human activity, tends to reduce crop productivity and leads to subsequent problems from deposition on farmlands and in water bodies. Comprehensive watershed management, however, can be used to protect these natural resources. In this study, a discrete time optimal control methodology and computational model are developed for determining land use and management alternatives that minimize sediment yield from agriculturally-dominated watersheds. The solution methodology is based on an …


Bs News Sep 2001

Bs News

Building Services Engineering

No abstract provided.


Ascent And Decompression Of Viscous Vesicular Magma In A Volcanic Conduit, Helene Massol, Claude Jaupart, Darrell Pepper Aug 2001

Ascent And Decompression Of Viscous Vesicular Magma In A Volcanic Conduit, Helene Massol, Claude Jaupart, Darrell Pepper

Mechanical Engineering Faculty Research

During eruption, lava domes and flows may become unstable and generate dangerous explosions. Fossil lava-filled eruption conduits and ancient lava flows are often characterized by complex internal variations of gas content. These observations indicate a need for accurate predictions of the distribution of gas content and bubble pressure in an eruption conduit. Bubbly magma behaves as a compressible viscous liquid involving three different pressures: those of the gas and magma phases, and that of the exterior. To solve for these three different pressures, one must account for expansion in all directions and hence for both horizontal and vertical velocity components. …


Analysis Of Traffic Growth Rates, Monica L. Barrett, R. Clark Graves, David L. Allen, Jerry G. Pigman, Ghassan Abu-Lebdeh, Lisa Aultman-Hall, Sarah T. Bowling Aug 2001

Analysis Of Traffic Growth Rates, Monica L. Barrett, R. Clark Graves, David L. Allen, Jerry G. Pigman, Ghassan Abu-Lebdeh, Lisa Aultman-Hall, Sarah T. Bowling

Kentucky Transportation Center Research Report

The primary objectives of this study were to determine patterns of traffic flow and develop traffic growth rates by traffic composition and highway type for Kentucky’s system of highways. Additional subtasks included the following: 1) a literature search to determine if there were new procedures being used to more accurately represent traffic growth rates, 2) development of a random sampling procedure for collecting traffic count data on local roads and streets, 3) prediction of vehicle miles traveled based on socioeconomic data, 4) development of a procedure for explaining the relationship and magnitude of traffic volumes on routes functionally classified as …