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2009

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Articles 541 - 570 of 655

Full-Text Articles in Civil and Environmental Engineering

Long Term Durability Studies On Chemically Treated Reclaimed Asphalt Pavement (Rap) Materials, Vijay Krishna Ganne Jan 2009

Long Term Durability Studies On Chemically Treated Reclaimed Asphalt Pavement (Rap) Materials, Vijay Krishna Ganne

Civil Engineering Theses - Archive

Reclaimed Asphalt Pavement (RAP) is a well known construction material which has been used in Hot Mix Asphalt (HMA) to reduce material costs and stabilizing the pavements for several years. It has been reported that out of 45 million tons of RAP produced every year in US, only 33% is being used in HMA. It is clear that a large amount of RAP produced is disposed off as a waste material in landfills. Hence, in order to utilize the maximum percentage of RAP and reduce the disposal rate, stabilized RAP can be effectively used as a base layer instead of …


Urban Transportation Planning Decision Making: A Robustness Analysis Approach, Deogratias Eustace Jan 2009

Urban Transportation Planning Decision Making: A Robustness Analysis Approach, Deogratias Eustace

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

Travel demand modeling remains a cornerstone of the transportation planning process. Although current transportation planning procedures are mostly performed by an interdisciplinary team approach, there are still a number of institutional issues which may hinder the process from providing the best results. According to Marshment (2001), the most notable setback is a lack of coordination between land use and transportation planning. Most of the time, land use plans do not reflect the influence of the accessibility to the alternative transportation facilities.

The lack of interaction between land use and transportation planning may play a major role in using unrealistic and …


Determining Emissions From Landfills And Creating Odor Buffer Distances, Nicholas Guarrieloo Jan 2009

Determining Emissions From Landfills And Creating Odor Buffer Distances, Nicholas Guarrieloo

Electronic Theses and Dissertations

With population growing every year, more and more people are looking for places to live. This can lead to construction of houses near and around landfills. As homes get closer to landfills, the odors these landfills produce become more of a problem, and lead to an increase in odor complaints. Modeling these odors and recommending odor buffer distances will help determine limits on how close to landfills new homes should be allowed. This should help reduce future odor complaints. To solve this problem one must accurately estimate odorous gas emissions from the landfill. Often odors can be indicated by methane …


Analyses Of Crash Occurence And Injury Severities On Multi Lane Highways Using Machine Learning Algorithms, Abhishek Das Jan 2009

Analyses Of Crash Occurence And Injury Severities On Multi Lane Highways Using Machine Learning Algorithms, Abhishek Das

Electronic Theses and Dissertations

Reduction of crash occurrence on the various roadway locations (mid-block segments; signalized intersections; un-signalized intersections) and the mitigation of injury severity in the event of a crash are the major concerns of transportation safety engineers. Multi lane arterial roadways (excluding freeways and expressways) account for forty-three percent of fatal crashes in the state of Florida. Significant contributing causes fall under the broad categories of aggressive driver behavior; adverse weather and environmental conditions; and roadway geometric and traffic factors. The objective of this research was the implementation of innovative, state-of-the-art analytical methods to identify the contributing factors for crashes and injury …


Evaluating The Impact Of Oocea's Dynamic Message Signs (Dms) On Travelers' Experience Using Multinomial And Ordered Logit For The Post-Deployment Survey, Taylor Lochrane Jan 2009

Evaluating The Impact Of Oocea's Dynamic Message Signs (Dms) On Travelers' Experience Using Multinomial And Ordered Logit For The Post-Deployment Survey, Taylor Lochrane

Electronic Theses and Dissertations

The purpose of this thesis was to evaluate the impact of dynamic message signs (DMS) on the Orlando-Orange County Expressway Authority (OOCEA) toll road network using the Post-Deployment DMS Survey analysis. DMS are electronic traffic signs used on roadways to give travelers information about travel times, traffic congestion, accidents, disabled vehicles, AMBER alerts, and special events. The particular DMS referred to in this study are large rectangular signs installed over the travel lanes and these are not the portable trailer mount signs. The OOCEA has added twenty-nine fixed DMS to their toll road network from 2006-2008. At the time of …


Safety Improvements On Multilane Arterials A Before And After Evaluation Using The Empirical Bayes Method, Prem Chand Devarasetty Jan 2009

Safety Improvements On Multilane Arterials A Before And After Evaluation Using The Empirical Bayes Method, Prem Chand Devarasetty

Electronic Theses and Dissertations

This study examines the safety effects of the improvements made on multi-lane arterials. The improvements were divided into two categories 1) corridor level improvements, and 2) intersection improvements. Empirical Bayes method, which is one of the most accepted approaches for conducting before-after evaluations, has been used to assess the safety effects of the improvement projects. Safety effects are estimated not only in terms of all crashes but also rear-end (most common type) as well as severe crashes (crashes involving incapacitating and/or fatal injuries) and also angle crashes for intersection improvements. The Safety Performance Functions (SPFs) used in this study are …


Characterizing Spontaneous Fires In Landfills, Shadi Moqbel Jan 2009

Characterizing Spontaneous Fires In Landfills, Shadi Moqbel

Electronic Theses and Dissertations

Landfill fires are relatively common incidents that landfill operators encounter which have great impact on landfill structure and the environment. According to a U.S. Fire Administration report in 2001, an average of 8,300 landfill fires occurs each year in the United States, most of them in the spring and summer months. Subsurface spontaneous fires are considered the most dangerous and difficult to detect and extinguish among landfill fires. Few studies have been conducted on spontaneous fires in landfills. Information regarding the thermal behavior of solid waste is not available nor have measurements been made to evaluate spontaneous ignition of solid …


Safety And Operational Evaluation Of Dynamic Lane Merging In Work Zones, Rami Harb Jan 2009

Safety And Operational Evaluation Of Dynamic Lane Merging In Work Zones, Rami Harb

Electronic Theses and Dissertations

Traffic safety and mobility of roadway work zones have been considered to be one of the major concerns in highway traffic safety and operations in Florida. In intent to expose Florida's work zones crash characteristics, the Florida Traffic Crash Records Database for years 2002, 2003 and 2004 were explored. Statistical models were estimated and Florida's work zone crash traits for single vehicle crashes and two-vehicle crashes were drawn. For the single-vehicle crashes, trucks were found more likely to be involved in single vehicle crashes in freeway work zones compared to freeways without work zones. Straight level roadways are significantly affected …


Spatio-Temporal Analyses For Prediction Of Traffic Flow, Speed And Occupancy On I-4, Srinivasa Ravi Chandra Chilakamarri Venkata Jan 2009

Spatio-Temporal Analyses For Prediction Of Traffic Flow, Speed And Occupancy On I-4, Srinivasa Ravi Chandra Chilakamarri Venkata

Electronic Theses and Dissertations

Traffic data prediction is a critical aspect of Advanced Traffic Management System (ATMS). The utility of the traffic data is in providing information on the evolution of traffic process that can be passed on to the various users (commuters, Regional Traffic Management Centers (RTMCs), Department of Transportation (DoT), ... etc) for user-specific objectives. This information can be extracted from the data collected by various traffic sensors. Loop detectors collect traffic data in the form of flow, occupancy, and speed throughout the nation. Freeway traffic data from I-4 loop detectors has been collected and stored in a data warehouse called the …


Providing A Better Understanding For The Motorist Behavior Towards Signal Change, Noor Elmitiny Jan 2009

Providing A Better Understanding For The Motorist Behavior Towards Signal Change, Noor Elmitiny

Electronic Theses and Dissertations

This research explores the red light running phenomena and offer a better understanding of the factors associated with it. The red light running is a type of traffic violation that can lead to angle crash and the most common counter measure is installing a red light running cameras. Red light running cameras some time can reduce the rates of red light running but because of the increased worry of the public towards crossing the intersection it can cause an increase in rear end crashes. Also the public opinion of the red light running cameras is that they are a revenue …


An Integrated Hydrology/Hydraulic And Water Quality Model For Watershed-Scale Simulations, Cheng Wang Jan 2009

An Integrated Hydrology/Hydraulic And Water Quality Model For Watershed-Scale Simulations, Cheng Wang

Electronic Theses and Dissertations

This dissertation presents the design of an integrated watershed model, WASH123D version 3.0, a first principle, physics-based watershed-scale model of integrated hydrology/hydraulics and water quality transport. This numerical model is comprised of three modules: (1) a one-dimensional (1-D) simulation module that is capable of simulating separated and coupled fluid flow, sediment transport and reaction-based water quality transport in river/stream/canal networks and through control structures; (2) a two-dimensional (2-D) simulation module, capable of simulating separated and coupled fluid flow, sediment transport, and reactive biogeochemical transport and transformation in two-dimensional overland flow systems; and (3) a three-dimensional (3-D) simulation module, capable of …


Structural Health Monitoring With Emphasis On Computer Vision, Damage Indices, And Statistical Analysis, Ricardo Zaurin Jan 2009

Structural Health Monitoring With Emphasis On Computer Vision, Damage Indices, And Statistical Analysis, Ricardo Zaurin

Electronic Theses and Dissertations

Structural Health Monitoring (SHM) is the sensing and analysis of a structure to detect abnormal behavior, damage and deterioration during regular operations as well as under extreme loadings. SHM is designed to provide objective information for decision-making on safety and serviceability. This research focuses on the SHM of bridges by developing and integrating novel methods and techniques using sensor networks, computer vision, modeling for damage indices and statistical approaches. Effective use of traffic video synchronized with sensor measurements for decision-making is demonstrated. First, some of the computer vision methods and how they can be used for bridge monitoring are presented …


Comprehensive Analytical Investigation Of The Safety Of Unsignalized Intersections, Kirolos Haleem Jan 2009

Comprehensive Analytical Investigation Of The Safety Of Unsignalized Intersections, Kirolos Haleem

Electronic Theses and Dissertations

According to documented statistics, intersections are among the most hazardous locations on roadway systems. Many studies have extensively analyzed safety of signalized intersections, but did not put their major focus on the most frequent type of intersections, unsignalized intersections. Unsignalized intersections are those intersections with stop control, yield control and no traffic control. Unsignalized intersections can be differentiated from their signalized counterparts in that their operational functions take place without the presence of a traffic signal. In this dissertation, multiple approaches of analyzing safety at unsignalized intersections were conducted. This was investigated in this study by analyzing total crashes, the …


A Study Of Central Florida Nonroad Voc And Nos Emissions And Potential Actions To Reduce Emissions, Michael Radford Jan 2009

A Study Of Central Florida Nonroad Voc And Nos Emissions And Potential Actions To Reduce Emissions, Michael Radford

Electronic Theses and Dissertations

Ground-level ozone is harmful to the human respiratory system, as well as the environment. The national EPA 8-hour ozone standard for ground-level ozone was reduced from 85 parts per billion (ppb) to 75 ppb in 2008, and trends from previous years show that some of the counties in Central Florida could be in danger of violation. Violation means "non attainment" status; in which the county is ordered by EPA to develop specific implementation plans to reduce its emissions. The objective of this study was to compile an emissions inventory of volatile organic compounds (VOCs) and nitrogen oxides (NOx) from nonroad …


Predicting The Perforation Response Of Honeycomb Sandwich Panels Using Ballistic Limit Equations, William P. Schonberg, Frank Schäfer, Robin Putzar Jan 2009

Predicting The Perforation Response Of Honeycomb Sandwich Panels Using Ballistic Limit Equations, William P. Schonberg, Frank Schäfer, Robin Putzar

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Man-made debris from previous spacecraft missions poses a serious threat to spacecraft that are launched to operate in Earth orbit because it can strike such spacecraft at extremely high velocities and consequently damage mission-critical systems. Most satellites are constructed with honeycomb sandwich panels as their primary structural elements. to be able to perform a risk analysis, it is important to know, in the event of such a meteoroid or orbital debris particle impact, whether or not the impacting particle or parts thereof will exit the rear of the sandwich panel. a recently developed set of ballistic limit equations for two …


Managed Lanes Weaving And Access Guideliness, Chulsu Yang Jan 2009

Managed Lanes Weaving And Access Guideliness, Chulsu Yang

Civil Engineering Dissertations - Archive

To maximize the potential for successful managed lanes (MLs) operations, there are critical design issues that require special attention. Adequate ML access spacing and length of the ML access opening are required for the preservation of freeway capacity, level of service, and safety. The traffic weaving from an entrance ramp to the general purpose lanes across to a ML access point and vice versa are effectively modeled as a two-sided Type C weave. The 2000 Highway Capacity Manual (HCM) methodology was calibrated for the major weave without lane balance or merging (standard Type C weave) but not for the two-sided …


Comparative Damage Of Different Truck Configurations On Jointed Plain Concrete Pavement, Tito P. Nyamuhokya Jan 2009

Comparative Damage Of Different Truck Configurations On Jointed Plain Concrete Pavement, Tito P. Nyamuhokya

Civil Engineering Theses - Archive

This study estimated the damage done by trucks with 35 different configurations on a typical structure of a Jointed Plain Concrete Pavement. The configurations were proposed by New York Department of Transportation, the sponsor of this study. The generalized three dimensional finite element program Abaqus was used to calculate the response of linear elastic rigid pavement structure under truck loading. The loads for each truck case were placed at critical locations on the surface of the pavement to obtain the maximum tensile stresses at the bottom of concrete slab. The computed tensile stresses were used in Darter fatigue model (1977) …


Laboratory Characterization Of Geogrid-Reinforced Unbound Granular Material For Use In Flexible Pavement Structures, Gael Souci Jan 2009

Laboratory Characterization Of Geogrid-Reinforced Unbound Granular Material For Use In Flexible Pavement Structures, Gael Souci

LSU Master's Theses

This thesis documents and summarizes research and background information carried on geogrid reinforced base course in pavement design. Research was experimental carried through Repeated Load Triaxial (RLT) tests at the Louisiana Transportation Research Center. The experimental tests were performed to observe the benefit of the geogrid as well as to differentiate between geogrid location, geometry and tensile modulus of the various geogrid. Experiments were also carried to further describe the Shakedown Theory and its use for characterization of base course materials. The experimental results showed that there was a benefit in placing the geogrid within the aggregate specimen. There were …


Thermomechanical Modeling And Optimization Of Friction Stir Welding, Manthan Malde Jan 2009

Thermomechanical Modeling And Optimization Of Friction Stir Welding, Manthan Malde

LSU Master's Theses

This thesis research implemented an existing thermomechanical model of friction stir welding process, and studied the surrogate model-based optimization approach to obtain optimal process parameters for the modeled friction stir welding process. As an initial step, the thermomechanical model developed by Zhu and Chao for friction stir welding of 304L stainless steel was replicated using ANSYS. The developed model was then used to conduct parametric studies to understand the effect of various input parameters like total rate of heat input, welding speed and clamping location on temperature distribution and residual stress in the workpiece. With the data from the simulated …


Gas Transfer In Air-Lifts Used To Recirculate Aquaculture Systems, Ryan Anthony Hearn Jan 2009

Gas Transfer In Air-Lifts Used To Recirculate Aquaculture Systems, Ryan Anthony Hearn

LSU Master's Theses

The following studies were conducted to determine hydraulic, aeration, and degasification characteristics associated with various air-lift pumps. The first study presented data on a 20.3 cm air-lift used to support adult Yellowtail broodstock (Seriola lalandi) in an oligotrophic warmwater marine RAS (recirculating aquaculture system). Empirical relationships were used to estimate actual oxygen and carbon dioxide mass transfer rates (AOTR & ACTR) as the inlet oxygen or carbon dioxide concentrations were perturbed under lift heights of 30.5, 38.1, and 45.7 cm. Transfer rates, kg of constituent per day, were found to be dependent on air injection depth and volume, aqueous gas …


Neck Muscles Activity And Upper Body Extremity Angles In Dynamic Overhead Lifting, Mohamed Wassim Mokrani Jan 2009

Neck Muscles Activity And Upper Body Extremity Angles In Dynamic Overhead Lifting, Mohamed Wassim Mokrani

LSU Master's Theses

Injuries of the neck and shoulders are common among workers who perform overhead tasks. In order to develop an injury-free working environment with regards to occupational musculoskeletal stress, it is pivotal to understand the pathophysiology of mechanical stress on the musculoskeletal system. The objective of this research was to study the effect of overhead lifting on the sternocleidomastoid and upper Trapezius muscles. Upper body joint angles were also analyzed using APAS during the overhead lifting. This study was conducted using two devices. The set of equipment incorporates an electromyography device, and the APAS. Two electrodes were placed at the muscle …


Prioritization Of Safety Countermeasures For The State Of Louisiana Using Fuzzy Inference Systems, Meisam Akbarzadeh Jan 2009

Prioritization Of Safety Countermeasures For The State Of Louisiana Using Fuzzy Inference Systems, Meisam Akbarzadeh

LSU Master's Theses

In this study a fuzzy inference system is proposed for prioritization of countermeasures aimed at improving safety in the state of Louisiana. Countermeasures are prioritized based on their collective performance on cost, expected crash reduction and the severity of the problem they address. These three decision parameters can have six permutations in terms of their relative importance in decision making. In order to make the prioritization procedure handier for decision makers, the inference system is capable of being run under all six possible cases. Current safety standards influence the importance attached to crash reduction performance and severity of the problem …


Laser Assisted Friction Stir Welding: Finite Volume Method And Metaheuristic Optimization, Shivani Daftardar Jan 2009

Laser Assisted Friction Stir Welding: Finite Volume Method And Metaheuristic Optimization, Shivani Daftardar

LSU Master's Theses

Friction Stir Welding (FSW) is a solid state joining process that uses a non-consumable rotating welding tool to generate frictional heat at the welding location. Large forces are required to produce friction between the welding tool and the work piece which increases the wear rate of the welding tool in welding materials with high melting temperature. Several different approaches have been developed to address this problem. This thesis focuses on a new modification of friction stir welding, called Laser Assisted Friction Stir Welding, a process developed in the last decade. This process uses laser energy to preheat the work piece …


Hearing Assessment Of Forest Loggers, Antonio A. Fonseca Jan 2009

Hearing Assessment Of Forest Loggers, Antonio A. Fonseca

LSU Master's Theses

Forest logging is the process in which trees are cut down for forest management and/or timber harvest. According to OSHA, logging is the most dangerous occupation in the United States. It consistently represents one of the most hazardous industries, with a fatality rate more than 21 times higher than the rate for all workers in the United States. Yet, little research has been performed to determine the long term effect of noise on forest loggers. OSHA regulations state that the maximum permissible hearing in an 8 hour shift should not exceed 90 dB. Occupational noise exposure is recognized as a …


Assessing The Accuracy Of Task Time Prediction Of An Emerging Human Performance Modeling Software - Cogtool, Oluwakemi Damilola Adio Jan 2009

Assessing The Accuracy Of Task Time Prediction Of An Emerging Human Performance Modeling Software - Cogtool, Oluwakemi Damilola Adio

LSU Master's Theses

There is a need for a human performance modeling tool which not only has the ability to accurately estimate skilled user task time for any interface design, but can be used by modelers with little or no programming knowledge and at a minimal cost. To fulfill this need, this research investigated the accuracy of task time prediction of a modeling tool – CogTool - on two versions of an interface design used extensively in the petrochemical industry – DeltaV. CogTool uses the KeyStroke Level Model (KLM) to calculate and generate time predictions based on specified operators. The data collected from …


Phosphorus Dynamics In The Marshland Upwelling System, Dhaval Shirish Shah Jan 2009

Phosphorus Dynamics In The Marshland Upwelling System, Dhaval Shirish Shah

LSU Master's Theses

The Marshland Upwelling System (MUS) is an alternative onsite wastewater treatment technology designed to utilize the natural ecology of saltwater marshes to remove human-borne contaminants. Previous research has assessed the ability of MUS to remove both total and orthophosphate. Studies have also indicated a clear zone of phosphorus (P) saturation occurring in MUS soils. Laboratory column study was performed to accomplish the objectives of this study which were to: 1) determine the fate and fractionation of phosphorus in the soil matrix, 2) understand sorption kinetics and determine phosphorus sorption potential of wetland soils in retaining phosphorus in the MUS, 3) …


Hydro Mechanical Behavior Of Unsaturated Soil Subjected To Drying, Dev Raj Pokhrel Jan 2009

Hydro Mechanical Behavior Of Unsaturated Soil Subjected To Drying, Dev Raj Pokhrel

LSU Master's Theses

The literature of unsaturated soils in terms of hydraulic and mechanical behavior is reviewed. The hydro- mechanical behavior of unsaturated soil was studied using experimental investigation and numerical simulation of 1D and 2D modeling in HYDRUS software. Low plasticity silty clay (CL) and sand bentonite mixed soil SB (5% and 2% bentonite) specimens were investigated. Soil water characteristics curve (SWCC) tests were carried out in CL sample along with shear wave velocity measurement test using bender element (BE). The influence of moisture variation on specimens was investigated to see its impact on suction and on stiffness of soil. Similarly, the …


Effects Of Physical And Mental Tasks On Heart Rate Variability, Satya Anasuya Paritala Jan 2009

Effects Of Physical And Mental Tasks On Heart Rate Variability, Satya Anasuya Paritala

LSU Master's Theses

Demands at work are associated with an increased risk of cardio vascular diseases, but little is known about its underlying connection. The purpose of this study was to evaluate the effects of physical and mental tasks that induced stress, on Heart Rate Variability (HRV). Another aim was to observe the trends in subjective workload ratings in conjunction with the physiological response of the heart and also to assess the comfort level of the participants while wearing the heart rate monitor and performing tasks. Heart rate was recorded while at rest and while performing the tasks. Subjective workload ratings were obtained …


Passenger Car Equivalents Of Trucks Under Lane Restriction And Differential Speed Limit Policies On Four Lane Freeways, John Stanley Jan 2009

Passenger Car Equivalents Of Trucks Under Lane Restriction And Differential Speed Limit Policies On Four Lane Freeways, John Stanley

LSU Master's Theses

Lane restriction for trucks and differential speed limits for trucks and cars are becoming more common and feasible policies to improve the efficiency and safety of a freeway. It is believed that passenger car equivalents for trucks are impacted by these non typical freeway operating conditions, which are not explicitly addressed by the latest edition of the Highway Capacity Manual. Using simulated and real world data an elevated 18- mile four lane freeway was modeled under the restriction policies. The section which was used as a test bed was simulated under various control variables. Some of the control variables used …


Numerical Modeling For Long Term Performance Of Soil-Bentonite Cut-Off Walls In Unsaturated Soil Zone, Sukanta Chakraborty Jan 2009

Numerical Modeling For Long Term Performance Of Soil-Bentonite Cut-Off Walls In Unsaturated Soil Zone, Sukanta Chakraborty

LSU Master's Theses

ABSTRACT The construction practices of containment walls are extremely important in this competitive economic market, but development is limited. Unsaturated zone is an integral part of the geotechnical problems, as it affects on any kind of soils structures. The unsaturated zone plays significant role in many aspects of water flow and contaminant transport, including containment system such as: cut-off walls, infiltration, soil moisture storage, evaporation, plant water uptake, ground water recharge, erosion, and runoff. This research focuses on the hydraulic sustainability and performance of soil-bentonite cutoff walls (Britton et al, 2004) models showing hydraulic behavior of barrier walls. The cutoff …