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Articles 871 - 900 of 1043
Full-Text Articles in Civil and Environmental Engineering
Characterization Of Hma Mixtures Containing High Recycled Asphalt Pavement Content With Crumb Rubber Additives, Samuel B. Cooper, Jr.
Characterization Of Hma Mixtures Containing High Recycled Asphalt Pavement Content With Crumb Rubber Additives, Samuel B. Cooper, Jr.
LSU Master's Theses
As the price of petroleum and material costs escalate and pressures of maintaining the sustainability of our environment, owners must continually find methods to decrease material costs and maximize their benefits. One such method is to increase and/or begin using readily available recycled materials like reclaimed asphalt pavements (RAP) and crumb rubber (CR). The objective of this study was to fundamentally characterize the laboratory performance of conventional HMA mixtures and mixtures containing high RAP content and waste tire crumb rubber/additives through their fundamental engineering properties. A Superpave l9-mm nominal maximum aggregate size (NMAS) Level 2 HMA mixture meeting LADOTD specification …
The Effectiveness Of The Introduction And Amendment Of Traffic Laws On Louisiana Road Crashes, Vamshi Krishna Mudumba
The Effectiveness Of The Introduction And Amendment Of Traffic Laws On Louisiana Road Crashes, Vamshi Krishna Mudumba
LSU Master's Theses
Evaluating the safety benefit of a treatment provides information to the future safety projects of our transportation system. Various transportation laws have been amended in the state of Louisiana, aiming to reduce the roadway crash rates. The major traffic laws introduced or amended in the state in the past decade were the Graduated Driver Licensing (GDL) Program in 1998, repealing the mandatory motorcycle helmet law in 1999 and reenacting it in 2004, introducing the open alcohol container laws in 2000, and lowering the per se Blood Alcohol Content (BAC) from 0.10 to 0.08 percent in 2003. A before-and-after analysis was …
Physical Modeling Of Flow And Sediment Transport Using Distorted Scale Modeling, Ryan L. Waldron
Physical Modeling Of Flow And Sediment Transport Using Distorted Scale Modeling, Ryan L. Waldron
LSU Master's Theses
As coastal Louisiana's land loss problem continues to grow unabated, many different solutions have been proposed. One such solution is the concept of diverting fresh water and sediment from the river into the coastal wetlands. Louisiana State University has a Small Scale Physical Model (SSPM) for the study of the potential of such diversions; it is deisgned to study the bulk movement of sediment in the river and diversions. The model is a distorted scale model with a horizontal scale of 1:12,000 and a vertical scale of 1:500; this extreme distortion has brought into question the applicability of the model. …
Airlift Assisted Wastewater Treatment, Brian Sidney Johnson
Airlift Assisted Wastewater Treatment, Brian Sidney Johnson
LSU Master's Theses
Static low density media (SLDM) filtration has been received with great admiration in the aquaculture industry and consequently spawned into the domestic wastewater setting on the pilot scale. This method of granular filtration uses plastic beads to facilitate the roles of both clarification and biofiltration into one compact unit. The fundamental operating principles utilized in this form of treatment can be greatly enhanced when they are coupled with self contained recirculation from airlift pumps. Recirculation of this type in a SLDM unit has the ability to provide multiple passes of the substrate in the wastewater through the bead bed to …
Pilot-Scale Study On Anaerobic Digestion Applied To A Saline Industrial Waste Activated Sludge, Changjiang Shen
Pilot-Scale Study On Anaerobic Digestion Applied To A Saline Industrial Waste Activated Sludge, Changjiang Shen
LSU Master's Theses
In the field of municipal wastewater treatment, anaerobic digestion is a well-established, effective process for stabilization of organic sludge with the attractive features of low operating costs and production of methane as a useful by-product. Application of anaerobic digestion for the treatment of saline industrial wastewater sludge, however, has not been well established. The studies described in this thesis were conducted with the overall goal of assessing the feasibility of mesophilic anaerobic digestion processes for treatment of waste activated sludge (WAS) containing moderate salinity (approximately 3% m/v). Experiments employed two 30-gallon conical-bottom HDPE reactors. In the first phase of testing, …
Three-Echelon Supply Chain Delivery Policy With Trade Credit Consideration, Farhana Rahman
Three-Echelon Supply Chain Delivery Policy With Trade Credit Consideration, Farhana Rahman
LSU Master's Theses
In recent years, collaboration in supply chain approach widely discussed in the literature; but most have dealt with the two-echelon systems. This study focuses on the just-in-time delivery policy of three-echelon supply chain by collaborative approach, where any of the information from the supply chain is available to all the subsystems involved; manufacturer, distribution center and retailer. In the first part of the study a simple model has been developed for a three-echelon supply system that consists of a single manufacturer, a single distribution center and a single retailer. The other part of the study extends this model by considering …
In-Situ And Nondestructive Test Methods Applied To The Design And Construction Of Pile Foundation Projects In Coastal Louisiana, Jesse Gerard Rauser
In-Situ And Nondestructive Test Methods Applied To The Design And Construction Of Pile Foundation Projects In Coastal Louisiana, Jesse Gerard Rauser
LSU Master's Theses
Construction projects in coastal Louisiana often require pile foundations as a result of the soft soils present, which complicate cast‐in‐place foundation construction and provide minimal support to shallow foundations. During a driven pile project, the engineering phase will require soil characterization and pile capacity determination, while construction will require quality assurance. These three elements, soil characterization, capacity determination, and quality assurance, are commonly accomplished using in‐situ and nondestructive testing. In this thesis, the application of some of these in‐situ and nondestructive methodologies to a project in Coastal Louisiana are examined. The Louisiana Transportation Research Center (LTRC) has released computer software …
Impact Damage Between The Collision Of A Vessel And Protective Fender Systems, Paul Joseph Kocke
Impact Damage Between The Collision Of A Vessel And Protective Fender Systems, Paul Joseph Kocke
LSU Master's Theses
Vessel collision with bridge pilings can cause a catastrophic event and are occurring at an alarming rate. Such events can lead to the collapse of a bridge, causing deaths, shutting down a primary route of transportation and costing millions of dollars in repairs. Today, the AASHTO Bridge Code gives designers a methodology toward designing bridge pilings to withstand the impact of an errant vessel. However, bridges designed before this code was written require a protective system that is capable of redirecting a colliding vessel without causing severe damage to the pilings or the vessel. This research will look into three …
Modeling The Relationship Among Occupational Stress, Psychological/Physical Symptoms And Injuries In The Construction Industry, Omosefe Osarieme Abbe
Modeling The Relationship Among Occupational Stress, Psychological/Physical Symptoms And Injuries In The Construction Industry, Omosefe Osarieme Abbe
LSU Master's Theses
The construction industry has one of the highest incidents of fatal and non-fatal accidents/injuries every year. As a high risk industry, there is a need to investigate factors that affect the occurrence of these accidents to be able to protect workers. Traditional approaches to workers’ safety in the construction industry have focused on the physical and biomechanical aspects of work by improving tools, equipment and task completion methods. However, the impact of psychosocial factors, specifically stress as experienced by construction workers is an area of growing research. Research in the area of occupational stress in the Construction Industry is yielding …
Characterization And Development Of Axle Load Spectra To Enhance Pavement Design And Performance On The Basis Of New Mechanistic-Empirical Design Guide In Louisiana, Bharath Kumar Sridhar
Characterization And Development Of Axle Load Spectra To Enhance Pavement Design And Performance On The Basis Of New Mechanistic-Empirical Design Guide In Louisiana, Bharath Kumar Sridhar
LSU Master's Theses
For pavement design practices, several factors must be considered to ensure good performance of the pavement over the anticipated life cycle. Such factors include, but are not limited to, the type of paving materials, traffic loading characteristics, prevailing environmental conditions, and others. Traditional pavement design practices have followed the standards set by the American Society of State Highway and Transportation Officials (AASHTO) which require the use of an equivalent single axle load (ESAL - 18 kip single axle load) for design traffic input. Recently, a new mechanistic-empirical pavement design guide (MEPDG) was developed to improve pavement design practices. The guide …
Modeling Of Solute Transport And Retention In Upper Amite River, Hoonshin Jung
Modeling Of Solute Transport And Retention In Upper Amite River, Hoonshin Jung
LSU Master's Theses
Streams play an important role in a solute transport through a stream network. Transient storage is one of the important processes that control mass exchange between a main stream and transient storage zones because of increase in the residence time of solute. In order to take account of the effect of transient storage on solute transport in streams, a variable residence time (VART) model was developed. The model is characterized by several features: (1) actual varying residence time was used, (2) no-user specified residence time distributions (RTD) were required, (3) less calibration parameters were involved as compared to existing models, …
Exploring Stochastic Characteristics Of Freeway Traffic Breakdown And Recovery Conditions, Chaitanya Mamidala
Exploring Stochastic Characteristics Of Freeway Traffic Breakdown And Recovery Conditions, Chaitanya Mamidala
LSU Master's Theses
In recent times, the term ‘congestion’ has gained a lot of attention due to its negative impact on the mobility and efficiency of transportation network. Congestion control and mitigation of its effects has become a prime concern to many transportation agencies. With breakthroughs in transportation technologies, effective management and utilization of existing infrastructure capacities has been possible. One of the key functions of technological advancements is the ability to understand the different characteristics of traffic that prevail on major freeways and arterials, and to model short-term predictions of traffic conditions with reasonable accuracy. Providing accurate, real-time information makes travelers aware …
Fate And Transport Of Microorganisms In Coastal Subsurface-Experiment And Modeling, Haibo Cao
Fate And Transport Of Microorganisms In Coastal Subsurface-Experiment And Modeling, Haibo Cao
LSU Doctoral Dissertations
The objective of this dissertation was to investigate the fate and transport of microorganisms in coastal subsurface. Two topics were studied: (1) evaluation of the performance of the Marshland Upwelling System (MUS) in removing fecal bacteria and the background recovery after it is shut down; (2) Investigation of the effects of salinity and soluble organic matter (SOM) on sorption of MS-2 and development of a model to describe the sorption and transport process. The MUS showed effective performance in removing fecal bacteria during its 32 month operation period at Bayou Segnette Site. The removal efficiency was increased with its operation …
Dynamic Shear Bands In Metals Under High Strain Rates, Amin Hisham Almasri
Dynamic Shear Bands In Metals Under High Strain Rates, Amin Hisham Almasri
LSU Doctoral Dissertations
Adiabatic shear bands have been observed for a long time to occur under different conditions in many applications. Analysis of these localizations highly depends on the selection of the constitutive model. Hence, two constitutive models that take temperature and strain rate effect into account are proposed. The first model is a physically based model that depends on basic physical quantities, such as dislocation densities, Burgers vector, and activation energy. The second model is a simple empirical power model with a softening term. The empirical constitutive law is seen to be more successful in capturing the mechanical behavior of steel alloy …
Nonlocal Gradient-Dependent Modeling Of Plasticity With Anisotropic Hardening, Gerald Pekmezi
Nonlocal Gradient-Dependent Modeling Of Plasticity With Anisotropic Hardening, Gerald Pekmezi
LSU Master's Theses
This work is concerned with the formulation of the thermodynamics of nonlocal plasticity using the gradient theory. The formulation is based on the nonlocality energy residual introduced by Eringen and Edelen (1972). Gradients are introduced for those variables associated with isotropic and kinematic hardening. The formulation applies to small strain gradient plasticity and makes use of the evanescent memory model for kinematic hardening. This is accomplished using the kinematic flux evolution as developed by Zbib and Aifantis (1987). Therefore, the present theory is a four nonlocal parameter-based theory that accounts for the influence of large variations in the plastic strain, …
Experimental Investigation Of Unsaturated Soil Stiffness, Ananth Bukkapatnam Tirumala
Experimental Investigation Of Unsaturated Soil Stiffness, Ananth Bukkapatnam Tirumala
LSU Master's Theses
Soil stiffness is a strain dependent non-linear parameter. Stiffness is the measure of soil deformation under a particular working load. It can used for predicting ground deformation in engineering earthworks such as highway embankments and foundations. Non-linear analyses for ground behavior have been widely used for developing models to predict the small –strain characteristics of the soil (Atkinson, 2000). This thesis provides a new insight into the behavior of soil stiffness. We used the wave propagation technique to determine the stiffness and term it as the small strain shear modulus (Gmax) of the soil. The objective of the thesis was …
Effect Of Hydrated Lime On The Laboratory Performance Of Superpave Mixtures, Md Sharear Kabir
Effect Of Hydrated Lime On The Laboratory Performance Of Superpave Mixtures, Md Sharear Kabir
LSU Master's Theses
Permanent deformation and moisture damage are the most common distresses found in asphalt pavements today. Extensive experimental studies have revealed that the use of hydrated lime in Hot-Mix Asphalt (HMA) mixtures can reduce permanent deformation, long-term aging, and moisture susceptibility of mixtures. In addition, it increases the stiffness and fatigue resistance of mixtures. The objectives of this study were to evaluate (1) the fundamental engineering properties of HMA mixtures containing hydrated lime compared to conventional mixtures designed to meet the current Louisiana Superpave specifications and (2) the influence of the method of addition of hydrated lime on the mechanical properties …
Application Of The Hyman Model To Evaluate The Water And Salt Budgets In Three Mangrove Sites Along Shark River, Everglades, Cheng-Feng Tsai
Application Of The Hyman Model To Evaluate The Water And Salt Budgets In Three Mangrove Sites Along Shark River, Everglades, Cheng-Feng Tsai
LSU Master's Theses
Mangrove trees play an important role in the maintenance and sustainability of coastal wetlands due to their ability to adapt and survive in a wide range of saline and tidal conditions. Hydrologic processes (e.g., inundation frequency) and salinity are important regulators controlling the growth and productivity of mangrove forests. To quantify how changes in landscape-level hydrology will influence these regulators in mangrove forests, the hydrology model (HYMAN) was applied to three sites with distinct tidal forcings along the Shark River estuary in the Everglades National Park. HYMAN model uses mass balance equation to determine daily water and salt budgets as …
Elasto-Plastic And Damage Modeling Of Reinforced Concrete, Ziad N. Taqieddin
Elasto-Plastic And Damage Modeling Of Reinforced Concrete, Ziad N. Taqieddin
LSU Doctoral Dissertations
Modeling the mechanical behavior of Reinforced Concrete (RC) is still one of the most difficult challenges in the field of structural engineering. The Nonlinear Finite Element Analysis (NFEA) and modeling of the behavior of RC members are the primary goals of this study. The macroscopic components of RC, Concrete material and reinforcing steel, are represented herein by separate material models. These material models are combined together using a model that describes the global effect of interaction between reinforcing steel and concrete in order to simulate the behavior of the composite RC material. A thermodynamically consistent constitutive model for concrete that …
Effects Of Capping On Biodegradation Of Organic Contaminants In Sediments, Eun Ju Lee
Effects Of Capping On Biodegradation Of Organic Contaminants In Sediments, Eun Ju Lee
LSU Doctoral Dissertations
Sediment capping remains an effective remediation technique for contaminated sediments due to its capability to contain contaminants and provide a sound habitat for indigenous biota. This research investigated the effect of capping on biodegradation of organic contaminants in Anacostia River sediments using both experimental and modeling techniques. 14C–Phenanthrene mineralization was monitored under various redox conditions in Anacostia River sediments. Mineralization of 14C–phenanthrene was strongly linked to sulfate reduction, which was the more energetic process than any other anaerobic condition in Anacostia sediments. Sulfate is a more promising terminal electron acceptor for intrinsic degradation in Anacostia River and other PAH contaminated …
Three Dimensional Behavior Of Retaining Wall Systems, Kevin Abraham
Three Dimensional Behavior Of Retaining Wall Systems, Kevin Abraham
LSU Doctoral Dissertations
The objective of this study was to perform an engineering assessment of key three-dimensional (3-D) soil-structure interaction (SSI) features of selected earth retaining walls utilizing the nonlinear finite element method (FEM). These 3-D features are not explicitly incorporated in conventional two-dimensional (2-D) procedures that are commonly used to design these retaining walls. The research objective was accomplished utilizing the nonlinear FEM. The retaining walls selected for this research were described in detail. Design methodologies and computed responses for the walls based on conventional 2-D design procedures were summarized. Key engineering features of these structures such as construction sequence and system …
Characterization Of Unsaturated Soils Using Elastic And Electromagnetic Waves, Bashar Alramahi
Characterization Of Unsaturated Soils Using Elastic And Electromagnetic Waves, Bashar Alramahi
LSU Doctoral Dissertations
Recent advances in laboratory instruments and techniques enabled researchers to explore new aspects of the behavior of geomaterials and perform measurements that would be otherwise impossible to acquire using traditional geotechnical laboratory techniques. This dissertation is focused on utilizing elastic and electromagnetic wave measurements and SMCT imaging to non-destructively characterize different aspects of the behavior of unsaturated soils. A model that relates P-wave velocity in soils to the volumetric water content was used to develop a new methodology to determine the in situ density and moisture content of soils. It was numerically and experimentally verified to assess it validity and …
Influence Of Temperature On The Performance Of Wetlands Treating Chlorinated Volatile Organic Compounds, Maria G. Murillo
Influence Of Temperature On The Performance Of Wetlands Treating Chlorinated Volatile Organic Compounds, Maria G. Murillo
LSU Master's Theses
Various studies have presented models to predict the performance of constructed wetlands at different temperatures focused on the removal of conventional pollutants, and common configuration of constructed wetlands. Investigations on the effect of temperature on the performance of constructed wetlands treating chlorinated volatile organic compounds are limited to microcosm studies. This study is meant to come up with kinetic and energy balance input data for mathematical models that can be used to predict the performance of upflow constructed treatment wetlands treating chlorinated ethenes and ethanes at different ambient temperatures. Bench scale continuous upflow columns will be conducted to investigate the …
Hydrodynamic Modeling Of A Hypothetical River Diversion Near Empire, Louisiana, Nathan Lamont Dill
Hydrodynamic Modeling Of A Hypothetical River Diversion Near Empire, Louisiana, Nathan Lamont Dill
LSU Master's Theses
Hydrodynamic models of a hypothetical Mississippi river diversion near Empire, LA are constructed using two popular finite element codes RMA2 and ADCIRC. In a series of simulations eddy viscosity parameters and bottom friction parameters are varied. Constant boundary conditions, discharge inflow and elevation outflow, are applied and water surface elevation and velocity solutions at fully developed flow are taken as steady-state results. A particle tracking code is developed and applied to the velocity solutions to aid in flow field comparisons. The results elucidate the model sensitivities to the varied parameters, and also provide for a comparison of the two different …
Evaluation Of Shear Strength Parameters Of Shale And Siltstone Using Single Point Cutter Tests, Mahendra Shewalla
Evaluation Of Shear Strength Parameters Of Shale And Siltstone Using Single Point Cutter Tests, Mahendra Shewalla
LSU Master's Theses
Detournay and Tan (2002) performed experiments with a rock cutting device to measure the load required to fail the rock under confining stress. They proposed models describing the correlation between the specific energy and confining stress for shear dilatant rocks as a function of unconfined specific energy at failure, cutter rake angle (θ), internal friction angle (φ) of the rock and an assumed interface friction angle (ψ) between the rock and the cutter. The aim of this research is to evaluate the model proposed by Detournay and Tan (2002), which states that specific energy varies linearly with bore hole pressure …
Study Of Ranking Irregularities When Evaluating Alternatives By Using Some Electre Methods And A Proposed New Mcdm Method Based On Regret And Rejoicing, Xiaoting Wang
LSU Master's Theses
Multi-criteria decision-making (MCDM) is one of the most widely used decision methodologies in the sciences, business, and engineering worlds. MCDM methods aim at improving the quality of decisions by making the process more explicit, rational, and efficient. One intriguing problem is that oftentimes different methods may yield different answers to the same decision problem. Thus, the issue of evaluating the relative performance of different MCDM methods is raised. One evaluating procedure is to examine the stability of an MCDM method’s mathematical process by checking the validity of its proposed rankings. The ELECTRE II and III methods are two well-known MCDM …
Urban Stream Stabilization Using Regional Hydraulic Geometry Curves For Bankfull Floodplain Design, Jonathan Edward Fourrier
Urban Stream Stabilization Using Regional Hydraulic Geometry Curves For Bankfull Floodplain Design, Jonathan Edward Fourrier
LSU Master's Theses
The objective of this thesis was to determine the effectiveness of hydraulic geometry curves for designing bankfull floodplains to stabilize urban streams. In stable streams bankfull discharge is contained within the stream's banks. Higher flows spread out onto the floodplain where the water's velocity drops due to the increase in area and vegetation. This dissipation of energy promotes sediment deposition, decreases flow velocity, and reduces channel erosion. In cases like Galbraith Drain where historical gage data are not available and bankfull indicators are not present, a degraded stream's bankfull depth may be estimated with hydraulic geometry curves. Over forty cross …
Production Well Operations Optimization In Water Distribution System Using Genetic Algorithm, Vineet Katiyar
Production Well Operations Optimization In Water Distribution System Using Genetic Algorithm, Vineet Katiyar
LSU Master's Theses
The City of Chandler, Arizona lies in semi-arid area and the water resources management has been a major concern by the State citizen. There is always a need of optimizing the available water resources when the rate of demand constantly beats the rate of replenishment. In this study we have developed a management model to link the Chandler water distribution model (EPANET) with the Chandler groundwater flow model (MODFLOW) under an optimization framework (Genetic algorithm). The EPANET model supplied by the Chandler city municipal authority has several improper setting (pumping schedules, valves settings, pressure zones etc.). The original model has …
Pile Capacity Utilization For Bridge Bents Designed Using Simplified Procedures, Md Rubiat Ferdous
Pile Capacity Utilization For Bridge Bents Designed Using Simplified Procedures, Md Rubiat Ferdous
LSU Master's Theses
Bent substructure systems are being used increasingly in bridge construction. Among the various bent systems, pile bents are considered a popular choice due to their effectiveness in reducing time and cost. They are constructed by first driving piles to a specified elevation above the ground surface. Then, a cast-in-place reinforced concrete bent cap ties the piles together at their top end. The current Louisiana Department of Transportation and Development Bridge Design Manual provides guidelines for the structural analysis and construction details for general use in the preparation of plans for pile bents. The manual allows the use of a simplified …
Pre-Treatment Of Dynamically Varying Waste Gas Concentrations Using Activated Carbon Prior To Biofiltration: Effect Of Cycle Length On Degree Of Load Equalization, Kodi L. Collins
LSU Master's Theses
Dynamically varying waste gas concentrations pose challenges to the operation and design of air pollution control techniques such as biofilters. Although design approaches are becoming well established for biofilters treating gases containing VOC concentrations that are constant as a function of time, many industrial processes emit gas streams contaminated with volatile organic compounds at concentrations that fluctuate with time. Application of an effective load equalization technique could eliminate some challenges associated with fluctuating pollutant concentrations. Recent research has demonstrated that granular activated carbon (GAC) can serve as a passively controlled system to provide load-equalization as a pre-treatment prior to biofiltration. …