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2012

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Articles 871 - 900 of 1093

Full-Text Articles in Civil and Environmental Engineering

Synthesis And Characterization Of Geopolymers For Infrastructural Applications, Jian He Jan 2012

Synthesis And Characterization Of Geopolymers For Infrastructural Applications, Jian He

LSU Doctoral Dissertations

In this study, the synthesis process, composition, and microstructure as well as mechanical properties of geopolymers generated by 3 different kinds of raw materials (i.e., metakaolin, mixture of red mud and fly ash, mixture of red mud and rice husk ash) was explored. For geopolymers from identical raw materials, variable parameters involved in the synthesis were examined to investigate the extent and degree of geopolymerization. Uniaxial compression testing was used to examine the mechanical properties (i.e. compressive strength, stiffness, and failure strain). Then the composition and microstructure were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) as well …


Dynamic Route Choice In Hurricane Evacuation, Meisam Akbarzadeh Jan 2012

Dynamic Route Choice In Hurricane Evacuation, Meisam Akbarzadeh

LSU Doctoral Dissertations

In this research a framework is developed for modeling route choice in hurricane evacuation. Two behavioral hypotheses are evaluated which together with the route choice model, constitute the contributions of the research. The first hypothesis states that beside congestion, other variables such as familiarity with the route, availability of fuel and shelter, facility class, and length of route have an effect on an evacuees' route choice. The second hypothesis states that as time passes and storm conditions change, the impact each variable has on route choice changes. The logit structure was used for modeling the choice process and stated choice …


Blast And Impact Resistance Of "Long" Carbon Fiber Reinforced Concrete, Darwin Ishmael Keener Jan 2012

Blast And Impact Resistance Of "Long" Carbon Fiber Reinforced Concrete, Darwin Ishmael Keener

Masters Theses

"Traditional reinforced concrete is one of the most commonly used materials for protective structures. However, conventional reinforced concrete (RC) is susceptible to significant spalling (small to medium sized chunks of concrete detaching from the original member) during blast events. The force of the blast turns spalled concrete into projectiles, resulting in secondary fragmentation. Furthermore, the concrete debris makes for difficult and uncertain footing. Both phenomena endanger personnel and complicate post-blast recovery efforts. Changes need to be made to conventional reinforced concrete structures to improve their blast and impact survivability and fragmentation resistance in order to protect personnel and facilitate post-blast …


Development Of Hydrograph-Based Approach To Modeling Fate And Transport Of Sediment-Borne Bacteria In Lowland Rivers, Bhuban Ghimire Jan 2012

Development Of Hydrograph-Based Approach To Modeling Fate And Transport Of Sediment-Borne Bacteria In Lowland Rivers, Bhuban Ghimire

LSU Doctoral Dissertations

Fecal pollution is one of the major factors responsible for water quality impairments of rivers and streams, particularly organic-rich fine-grained lowland streams. While predicting fecal pollution is generally required in the development of water quality restoration plans like Total Maximum Daily Loads, no single model has been widely recognized as an efficient and effective tool for estimating fecal pollution. This dissertation develops a simple yet effective modeling approach, called Hydrograph-based Approach, to bacterial fate and transport modeling in lowland rivers. The new hydrograph-based approach is simple and efficient in terms of its less data requirements as compared with other models. …


Thermal Stress Analysis Of Jointed Plain Concrete Pavements Containing Fly Ash And Slag, Yoonseok Chung Jan 2012

Thermal Stress Analysis Of Jointed Plain Concrete Pavements Containing Fly Ash And Slag, Yoonseok Chung

LSU Doctoral Dissertations

With the current demand for Portland cement concrete (PCC) sustainability, supplementary cementitious materials (SCMs) are used in concrete mixtures. The SCMs positively impact the environmental and economic aspects of concrete mixtures and improve the mixture properties in both fresh and hardened concrete. In this research, one control and twenty-four ternary mixtures, with various combinations of fly ashes (Class C and F), slags (Grade 100 and 120), and Portland cement were fabricated. The thermal properties (coefficient of thermal expansion (CTE), thermal conductivity, and heat capacity) and mechanical properties of the selected ternary mixtures were measured at various ages. Temperature gradients were …


In Planta Solid Phase Sampling Devices Used In Delineating Groundwater Contaminant Plumes, Mikhil Kishore Shetty Jan 2012

In Planta Solid Phase Sampling Devices Used In Delineating Groundwater Contaminant Plumes, Mikhil Kishore Shetty

Masters Theses

"The widespread and indiscriminate use of chlorinated volatile organic compounds as cleaning agents at dry - cleaning facilities, as metal degreasers and solvents in extraction and removal operations has been well documented in the past resulting in releases, while contaminating soil and groundwater. Current techniques to assess chlorinated solvents such as tetrachloroethylene (PCE) and trichloroethylene (TCE) in the subsurface have been time and cost intensive and more importantly invasive to the surrounding environment. New methods use trees as sources of information to access contaminant plume size and plume delineation. The major goal of these research studies has been to save …


Field Investigation Of Wave And Surge Attenuation In Salt Marsh Vegetation And Wave Climate In A Shallow Estuary, Ranjit S. Jadhav Jan 2012

Field Investigation Of Wave And Surge Attenuation In Salt Marsh Vegetation And Wave Climate In A Shallow Estuary, Ranjit S. Jadhav

LSU Doctoral Dissertations

This research investigates and quantifies the effectiveness of salt marsh vegetation in reducing storm-induced waves and surge, and the potential for wetland erosion due to wave action, using field measurements on the Louisiana coast. To quantify wave attenuation and wave energy dissipation by vegetation (Spartina alterniflora), wave data were measured along a transect using pressure transducers during two tropical storms. Measurements showed that incident waves attenuated exponentially over the vegetation. The linear spatial wave height reduction rate increased from 1.5% to 4% /m as incident wave height decreased. The bulk drag coefficient estimated from the field measurements decreased with increasing …


Prediction And Performance Of Single Piles In Clay Soils Under Vibratory Loadings, Domenica Cambio Jan 2012

Prediction And Performance Of Single Piles In Clay Soils Under Vibratory Loadings, Domenica Cambio

Doctoral Dissertations

"This study developed a model for predicting the response, in terms of amplitude versus frequency of single piles under lateral vibratory loadings embedded in clay or fine silty soils. The model incorporates frequency dependent parameters and the effects of soil non-linearity through the relationship between soil shear modulus and damping with strain. A computer program, Dyna5, was used to generate the computed response of single piles using the Novak and El-Shamouby (1983) approach. Soil non-linearity was accounted for by incorporating spline interpolation routine into Dyna5. Sliding and coupled rocking vibrations were addressed. The computed responses were predicted and compared with …


Behavior Of Staged Externally Bonded Carbon Fiber Reinforced Polymer Sheets For Improved Ductility, Laura Marie Rathe Jan 2012

Behavior Of Staged Externally Bonded Carbon Fiber Reinforced Polymer Sheets For Improved Ductility, Laura Marie Rathe

Masters Theses

"Fiber reinforced polymers (FRP) has become increasingly used for the retrofit of aging structures for increased lifespans and for the rapid repair of damaged structures. It has many advantageous such as ease in rapid installation, high strength-to-weight ratio, and corrosion resistance. The main disadvantage of the material is brittle behavior with little warning of impending failures. The main objective of this study is to develop a new system of FRP that exhibits a more ductile behavior. To achieve this objective, separate sheets of FRP were applied at various staged levels and thus engaged at different loads. Ductile behavior was evaluated …


Analysis Of Passive Louver Shading Systems And Impact On Interior Environment, Cory Joseph Brennan Jan 2012

Analysis Of Passive Louver Shading Systems And Impact On Interior Environment, Cory Joseph Brennan

Masters Theses

An installed passive louver shading systems can affect the heating, cooling, and lighting loads of any building, by altering the amount of solar energy, in the form of light and heat, from entering. The benefits of a louver system are derived from the application of solar geometry incident on the site and the climate within the area. By optimizing a passive louver system's design parameters, a building can reduce the total annual energy consumption due to artificial heating, cooling loads and artificial lighting. This research has implemented simulation modeling software, Energy Plus, to predict the effect of passive louver shades …


Effects Of High Volumes Of Fly Ash On Cement Paste, Karl Wehking Beckemeier Jan 2012

Effects Of High Volumes Of Fly Ash On Cement Paste, Karl Wehking Beckemeier

Masters Theses

"The study of high-volume fly ash (HVFA) concrete mixtures has become popular due to the significant environmental and economic benefits which the material may provide. By including fly ash at 50 percent or greater replacement levels, substantial benefits could be obtained. However, the inclusion of fly ash can have negative effects, including incompatibilities between constituents of a mixture. As the fly ash replacement level increases, the degree and likelihood of these problems increases.

In this study, paste mixtures were made, as part of a larger HVFA concrete study, in order to determine the degree to which varying levels of fly …


Depth Profiling Of Pahs Treated With Activated Carbon Using In-Situ Spme, Ryan D. Stringer Jan 2012

Depth Profiling Of Pahs Treated With Activated Carbon Using In-Situ Spme, Ryan D. Stringer

Masters Theses

"Novel and efficient methods to measure the bioavailability of hydrophobic organic contaminants (HOCs) in contaminated sediments will play an important role in the acceptance of alternative sediment remediation strategies. In this project, solid phase microextraction (SPME) fibers, protected in perforated steel tubes, were used as in situ passive samplers to measure the treatment of activated carbon (AC) in polycyclic aromatic hydrocarbon (PAH) contaminated sediment. Contaminated sediment was treated with two modes of AC waterjet amendment. In the first treatment, a single 2-min injection was shot into the center of a test vessel and in the second treatment, multiple 7-sec injections …


Transport Of A Methamphetamine Surrogate Through Painted Drywall And Accumulation In Insulation, Nishanthini Vijayakumar Shakila Jan 2012

Transport Of A Methamphetamine Surrogate Through Painted Drywall And Accumulation In Insulation, Nishanthini Vijayakumar Shakila

Masters Theses

"Methamphetamine is a drug of abuse in the United States and it is frequently produced in residential "meth labs." During a specific cooking stage called "salting out", a high concentration of methamphetamine is released into the air and can accumulate on and within indoor surfaces. Even after remediation, methamphetamine and other chemicals can be released into the occupied space by diffusion and desorption from insulation and painted drywall. To better understand the emission characteristics of methamphetamine, the diffusion coefficient of n- isopropylbenzylamine (NIBA; an isomer and surrogate for methamphetamine) was measured in latex painted drywall. To quantify the diffusion coefficient, …


Characterization Of Soil Variability For Reliability-Based Design, Sitenikechukwu Onyejekwe Jan 2012

Characterization Of Soil Variability For Reliability-Based Design, Sitenikechukwu Onyejekwe

Doctoral Dissertations

"A very carefully planned Missouri-wide field exploration and laboratory investigation program, with a focus on fine-grained soils, was executed with the aim of characterizing the variability of geotechnical parameters statistically with a view to increasing the use of reliability-based design (RBD) among geotechnical engineers. Geotechnical parameters were characterized in terms of both their first and second statistical moments and their coefficient of variation (COV). Their probability distributions and their scale of fluctuation, θ, were also determined. Correlations between difficult-to-obtain parameters and more easily-obtained parameters were developed and the degree of fit of study data to published empirical correlations was investigated. …


Bond, Transfer Length, And Development Length Of Prestressing Strand In Self-Consolidating Concrete, Krista Beth Porterfield Jan 2012

Bond, Transfer Length, And Development Length Of Prestressing Strand In Self-Consolidating Concrete, Krista Beth Porterfield

Masters Theses

"Due to its economic advantages, the use of self-consolidating concrete (SCC) has increased rapidly in recent years. However, because SCC mixes typically have decreased amounts of coarse aggregate and high amounts of admixtures, industry members have expressed concerns that the bond of prestressing strand in SCC may be compromised. While the bond performance of prestressing strand in a new material such as SCC is an important topic requiring investigation, the results are only applicable if the research is completed on strands with similar bond quality as the strands used in the field. Therefore, the objectives of this research program were …


Effects Of High Volume Fly Ash And Powder Activators On Plastic And Hardened Concrete Properties, Drew Alexander Davis Jan 2012

Effects Of High Volume Fly Ash And Powder Activators On Plastic And Hardened Concrete Properties, Drew Alexander Davis

Masters Theses

This study was performed to examine the effects of high volumes of Class C fly ash modified by powder activators upon the plastic and hardened properties of concrete. In a companion study, five Missouri area cements and five Class C fly ashes were examined for incompatibilities, with the most and least reactive combinations being scaled up to full scale concrete testing. Two baseline concrete mixtures were examined, the only difference in mixtures being the sources of portland cement and fly ash. Fly ash replacement was examined at 50% and 70% replacement (by total cementitious mass). Three powder activators were used …


Shear And Fracture Behavior Of High-Volume Fly Ash Reinforced Concrete For Sustainable Construction, Carlos Andres Ortega Ordonez Jan 2012

Shear And Fracture Behavior Of High-Volume Fly Ash Reinforced Concrete For Sustainable Construction, Carlos Andres Ortega Ordonez

Doctoral Dissertations

"Concrete is the most widely used man-made material on the planet. Unfortunately, producing Portland cement generates carbon dioxide (a greenhouse gas) at roughly a pound for pound ratio. High-volume fly ash (HVFA) concrete- concrete with at least 50% of the cement replaced with fly ash - offers a potential "green" solution. However, because it is still relatively new and has some disadvantages, there are still many questions that need to be answered. Most research to date has consisted only of the evaluation of the strength and durability of HVFA concrete mixtures, while only a limited number of studies have implemented …


Implementation And Assessment Of A Virtual Reality Experiment In The Undergraduate Themo-Fluids Laboratory, Sushil Chaturvedi, Jaewan Yoon, Rick Mckenzie, Petros J. Katsioloudis, Hector M. Garcia, Shuo Ren Jan 2012

Implementation And Assessment Of A Virtual Reality Experiment In The Undergraduate Themo-Fluids Laboratory, Sushil Chaturvedi, Jaewan Yoon, Rick Mckenzie, Petros J. Katsioloudis, Hector M. Garcia, Shuo Ren

Mechanical & Aerospace Engineering Faculty Publications

Results are presented from an NSF supported project that is geared towards advancing the development and use of virtual reality (VR) laboratories, designed to emulate the learning environment of physical laboratories. As part of this project, an experiment in the undergraduate thermo-fluids laboratory course titled "Jet Impact Force" was transformed into a 3-D virtual reality experiment using the widely used MAYA R and VIRTOOLS R software. In order to facilitate students' interactions with the newly created 3-D interactive, immersive and stereoscopic virtual laboratory environment, the human computer interfaces (HCI) were programmed and incorporated in the simulation software. Two immersion levels …


Sustainable Riparian Restoration - The Utilization Of Sewage Effluent To Construct Wetlands Along The Rio Grande: A String Of Pearls Approach To Replenishment, Michael Earl Landis Jan 2012

Sustainable Riparian Restoration - The Utilization Of Sewage Effluent To Construct Wetlands Along The Rio Grande: A String Of Pearls Approach To Replenishment, Michael Earl Landis

Open Access Theses & Dissertations

The Rio Grande, from Elephant Butte Dam to El Paso, has been transformed from a free-flowing wild river into a highly engineered irrigation system. The Rio Grande Project, authorized by Congress in 1905, mandated the Bureau of Reclamation to store and deliver water exclusively to farmers. The river, maintained by the International Boundary and Water Commission, has been straightened and channelized between levees. The laws and policies governing the use of the waters of the Rio Grande are prohibitive to ecological restoration. Prior Appropriation doctrine allows for the exclusive use of these waters.

One sustainable tactic for replenishing the denuded …


Alternatives To Piloting In Bracksih Waters: Accuracy And Precision Of Commerical Reverse Osmosis Membrane Design Model Projections, Erika Mancha Jan 2012

Alternatives To Piloting In Bracksih Waters: Accuracy And Precision Of Commerical Reverse Osmosis Membrane Design Model Projections, Erika Mancha

Open Access Theses & Dissertations

In a time of economic recession and drought, the Texas Water Development Board is reviewing alternatives to the current Texas Commission on Environmental Quality requirement of demonstration-scale pilot testing membrane desalination to decrease permitting costs and project construction delays. One alternative is to use engineering judgment with membrane manufacturer's software models to predict membrane performance and ensure that product water quality requirements will be met. To comply with state permitting requirements, the first few months of successful full-scale operation can be submitted in lieu of pilot demonstration.

The goal of this research is to characterize the accuracy and precision of …


Investigation Of Gas-Solid Fluidized Bed With Non-Spherical Particles, Mario Alberto Ruvalcaba Jan 2012

Investigation Of Gas-Solid Fluidized Bed With Non-Spherical Particles, Mario Alberto Ruvalcaba

Open Access Theses & Dissertations

The number of experimental and numerical studies of multiphase flows has remarkably increased over the last several years. This research has abundant applications in energy, chemical, and conversion processes. Common use of these technologies includes catalytic cracking for petroleum refineries, fluidized bed reactors (type of chemical reactor), interface modification, and has been an important technology breakthrough in coal gasification. The present work will concentrate on the investigation and validation of gas-solid flows utilizing numerical methods. The gas-solid flows study on this research assumes the solid and gas phases as continua with averaged properties.

The fluid flow computation was achieved using …


Project-Risk Management And Decision Analysis In Maritime Maintenance And Repair, Michael C. Plumb, C. Ariel Pinto, Rafael Landaeta, Resit Unal, Thomas Murphy Jan 2012

Project-Risk Management And Decision Analysis In Maritime Maintenance And Repair, Michael C. Plumb, C. Ariel Pinto, Rafael Landaeta, Resit Unal, Thomas Murphy

Engineering Management & Systems Engineering Faculty Publications

The purpose of this paper is to provide insights regarding the implementation of using Project Risk Management (PRM) and Decision Analysis (DA) in managing projects for complex systems such as maritime vessels. The PRM approach apprehends many forms of risk both internal and external within a given project and assists the manager in determining the level of importance of each individual project phase and component to optimize project success. Ship Maintenance and Repair project decision-making requires that risk management and risk analysis techniques be applied in order to guide management in making better decisions to meet ship service life perspective. …


A Comparison Of Aluminum And Iron-Based Coagulants For Treatment Of Surface Water In Sarasota County, Florida, David Yonge Jan 2012

A Comparison Of Aluminum And Iron-Based Coagulants For Treatment Of Surface Water In Sarasota County, Florida, David Yonge

Electronic Theses and Dissertations

In this research, five different coagulants were evaluated to determine their effectiveness at removing turbidity, color and dissolved organic carbon (DOC) from a surface water in Sarasota County, Florida. Bench-scale jar tests that simulated conventional coagulation, flocculation, and sedimentation processes were used. Iron-based coagulants (ferric chloride and ferric sulfate) and aluminum-based coagulants (aluminum sulfate, polyaluminum chloride (PACl) and aluminum chlorohydrate (ACH)) were used to treat a highly organic surface water supply (DOC ranging between 10 and 30 mg/L), known as the Cow Pen Slough, located within central Sarasota County, Florida. Isopleths depicting DOC and color removal efficiencies as a function …


Engineering Characteristics Of Recyled Plastic Pin, Lumber And Bamboo For Soil Slope Stabilization, Faisal Shakib Ahmed Jan 2012

Engineering Characteristics Of Recyled Plastic Pin, Lumber And Bamboo For Soil Slope Stabilization, Faisal Shakib Ahmed

Civil Engineering Theses - Archive

Shallow slope failures are predominant in North Texas and pose a significant maintenance problem. The traditional slope repair and stabilization techniques become expensive in some instances with direct costs associated in maintenance and repair of landslides. A new approach for slope stabilization has been developed using Recycled Plastic Pins ( RPP) to reinforce slope movements. The engineering properties of RPP in compression and bending strength along with environmental considerations dictate the design and repair of slopes using RPP. Two other materials have also been considered as an alternative: (1) Wood lumber and (2) Bamboo. Wood has many advantages as an …


Development Of A Flexible Pavement Design Procedure Based On The Mechanistic - Empirical Pavement Design Guide: A Case Study, Ali Qays Abdullah Jan 2012

Development Of A Flexible Pavement Design Procedure Based On The Mechanistic - Empirical Pavement Design Guide: A Case Study, Ali Qays Abdullah

Civil Engineering Theses - Archive

This research developed design tables of new flexible pavement structures for New York State Department of Transportation based on the Mechanistic Empirical Design Guide (MEPDG). The design tables were developed using the MEPDG software for Regions 1, 3, and 7 for Upstate part of New York State and for Regions 8, 10, and 11 for the Downstate part of New York State. The MEPDG software was used to run design cases for combinations of: climate conditions, traffic volume, subgrade soil stiffness (Mr) and pavement structures. The conditions that the MEPDG was used to run were: the road structures classified as …


Shear Strength Of Web-Tapered I-Shaped Members, Ryan Paul Studer Jan 2012

Shear Strength Of Web-Tapered I-Shaped Members, Ryan Paul Studer

Theses and Dissertations--Civil Engineering

Plate girders are fabricated in situations where standard structural shapes do not possess the required strength necessary to carry applied loads. In many instances, plate girders are tapered so that the resistance to bending is proportional to the bending moment, creating cost effective, aesthetically pleasing structures. The AISC 2010 Specifications accurately predict the flexural capacity of tapered plate girders but recent research has suggested that the required shear strength is overly conservative. The researchers postulate that the required shear strength is overly conservative due to an effect known as modified shear that has been neglected from the AISC 2010 Specifications …


Identifying Hot-Spots Of Fecal Contamination In The Royal Spring Karstshed, Samuel C. Lee Jan 2012

Identifying Hot-Spots Of Fecal Contamination In The Royal Spring Karstshed, Samuel C. Lee

Theses and Dissertations--Civil Engineering

The City of Georgetown, Kentucky relies on a vast karst spring network as a drinking water source. This karst feature has several inputs from sinkholes and streams in the Cane Run Watershed: a watershed associated with a variety of land uses in the recharge area. The recharge area encompasses the area from North Lexington to Georgetown and is composed of urban, suburban, agricultural and industrial usage. A serious water quality issue exists with respect to the impact of fecal contamination within the spring recharge area. Identification of fecal contamination is quantified by microbial indicators adapted from surface water applications: fecal …


A New Simulation-Based Conflict Indicator As A Surrogate Measure Of Safety, Chen Wang Jan 2012

A New Simulation-Based Conflict Indicator As A Surrogate Measure Of Safety, Chen Wang

Theses and Dissertations--Civil Engineering

Traffic safety is one of the most essential aspects of transportation engineering. However, most crash prediction models are statistically-based prediction methods, which require significant efforts in crash data collection and may not be applied in particular traffic environments due to the limitation of data sources. Traditional traffic conflict studies are mostly field-based studies depending on manual counting, which is also labor-intensive and oftentimes inaccurate. Nowadays, simulation tools are widely utilized in traffic conflict studies. However, there is not a surrogate indicator that is widely accepted in conflict studies.

The primary objective of this research is to develop such a reliable …


An Innovative Approach To Mechanistic Empirical Pavement Design, Ronnie Clark Graves Ii Jan 2012

An Innovative Approach To Mechanistic Empirical Pavement Design, Ronnie Clark Graves Ii

Theses and Dissertations--Civil Engineering

The Mechanistic Empirical Pavement Design Guide (MEPDG) developed by the National Cooperative Highway Research Program (NCHRP) project 1-37A, is a very powerful tool for the design and analysis of pavements. The designer utilizes an iterative process to select design parameters and predict performance, if the performance is not acceptable they must change design parameters until an acceptable design is achieved.

The design process has more than 100 input parameters across many areas, including, climatic conditions, material properties for each layer of the pavement, and information about the truck traffic anticipated. Many of these parameters are known to have insignificant influence …


Development Of Strategies To Minimize The Release Of Trace Elements From Coal Waste Sources, Mohammad Rezaee Jan 2012

Development Of Strategies To Minimize The Release Of Trace Elements From Coal Waste Sources, Mohammad Rezaee

Theses and Dissertations--Mining Engineering

To assess strategies aimed at minimizing the release of trace elements and the impact of disposal of coal waste materials on the environment, two long-term leaching experiments of up to five months duration were performed using waste materials from two plants cleaning high and low sulfur bituminous coal. The tests evaluated the mobility of major trace elements under different disposal scenarios: (i) a static leaching test designed to simulate the quiescent conditions encountered by coal waste material stored under water in a stable impoundment, and (ii) a dynamic test to simulate waste materials exposed to the atmosphere, either in variable …