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

Engineering Commons

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

Articles 1 - 7 of 7

Full-Text Articles in Engineering

Transit-Based Emergency Evacuation Modeling With Microscopic Simulation, Hana H. Naghawi Jan 2010

Transit-Based Emergency Evacuation Modeling With Microscopic Simulation, Hana H. Naghawi

LSU Doctoral Dissertations

Several recent mass evacuations, including those in advance of Hurricane Katrina in New Orleans and Hurricane Rita in Houston, have demonstrated the effects of limited planning for carless populations. The lack of planning left a significant portion of the mobility-limited population of both these cities unable to flee in advance of the storms. Since 2005 however, both of these cities (as well as others across the United States) have developed transit assisted mass evacuation plans at various levels of detail. Since these plans are relatively recent and do not have a history of experience on which to base their performance, …


Studies Of Hydrophobic Organic Pollutant Interactions With Cyclodextrin: Implication For Groundwater Remediation, Heng Gao Jan 2010

Studies Of Hydrophobic Organic Pollutant Interactions With Cyclodextrin: Implication For Groundwater Remediation, Heng Gao

LSU Doctoral Dissertations

Henry’s Law constants of several common, subsurface hydrophobic organic pollutants (HOPs) including trichloroethylene (TCE), perchloroethylene (PCE) and benzene, toluene, ethylbenzene and o-xylene (BTEX), were measured over a range of temperatures (35, 45, 55 and 65°C) and cyclodextrin (CD) concentrations (0, 10, 20, 50 and 100 g L-1). In aqueous CD solutions, Henry’s constant values decrease by a power law relationship with increasing CD concentration due to an apparent solubility enhancement caused by HOP partitioning to the hydrophobic cavity of CD molecules. The temperature dependence of air-water partitioning under the influence of CD was well described by the van’t Hoff equation …


Dynamic Trip Distribution Models For Hurricane Evacuation, Guangxiang Cheng Jan 2010

Dynamic Trip Distribution Models For Hurricane Evacuation, Guangxiang Cheng

LSU Doctoral Dissertations

The dissertation presents several methods to estimate time-dependent origin-destination (O-D) trip tables for hurricane evacuation using survey data from hurricane Floyd in South Carolina in 1999. A static disaggregate destination choice model in multinomial logit form was developed considering household characteristics, hurricane threats, and destination socioeconomic and demographic characteristics. Models were developed for persons evacuating to friends or relatives, and hotels or motels separately. None of the household characteristics of evacuees were found to be significant in distinguishing destination choice but destination characteristics were. The model was tested by comparing the observed destination choices with predicted values via trip length …


Influence Of Unstable Soil Movement On Pile-Founded Concrete Floodwalls And A Resulting Design Methodology, Richard James Varuso Jan 2010

Influence Of Unstable Soil Movement On Pile-Founded Concrete Floodwalls And A Resulting Design Methodology, Richard James Varuso

LSU Doctoral Dissertations

Efforts are underway in the New Orleans area to raise the elevations of its levee system to combat the effects of hurricane storm surge. When complete, the majority of the system will be comprised of a combination of levees, sheet pile I-Walls, floodgates, and pile-supported concrete floodwalls, commonly referred to as T-Walls. Given the magnitude of the hydrostatic forces associated with storm surge, global instability is failure mechanism that must be considered in the design of T-Walls. In the past, it was assumed that these forces would be resisted by the T-Wall’s sheet pile cut-off wall. Recent literature review and …


Identifying And Quantifying Factors Affecting Traffic Crash Severity In Louisiana, Hong Zhang Jan 2010

Identifying And Quantifying Factors Affecting Traffic Crash Severity In Louisiana, Hong Zhang

LSU Doctoral Dissertations

This study was conducted to identify and quantify the factors affecting highway crash severity in Louisiana. Three candidate models were fit to the crash data to compare their performance and the Ordered Mixed Logit (OML) model was selected as the crash severity prediction model of choice. The factors contributing to crash severity identified by the OML model are: age and gender of the driver, vehicle speed, whether alcohol played a role in the crash, whether seatbelts were used, whether the driver was ejected from the vehicle, whether the crash was a head-on collision, whether an airbag was deployed, and whether …


Friction And Wear At Elevated Velocities, Adam Lodygowski Jan 2010

Friction And Wear At Elevated Velocities, Adam Lodygowski

LSU Doctoral Dissertations

Severe contact stress problems generate high temperature and create thermomechanical gouging and wear due to high velocity sliding between contacting materials. The major consideration is to develop an experimental and theoretical model for the material constitutive behavior in order to better characterize and predict the internal failure surroundings the gouging and wear events and understand the physical behavior of high speed contact environment. An enhancement of an existing tribometer device developed by Philippon et al. [2004] is made up of a dynamometer ring and a load sensor that allows to apply an apparent normal force on specimens and measure frictional …


Probabilistic Models For Short Term Traffic Conditions Prediction, Yan Qi Jan 2010

Probabilistic Models For Short Term Traffic Conditions Prediction, Yan Qi

LSU Doctoral Dissertations

Accurate short-term prediction of traffic condition on freeways and major arterials has become increasingly important because of its vital role in traffic management functions and various trip decisions. Given the dynamic nature of freeway traffic, this study proposed two stochastic model approaches, Hidden Markov Model (HMM) and One-Step Stochastic Model, for short-term traffic prediction during peak periods. The data used in the study are real-time traffic monitoring data gathered over 6 years on a 40-mile segment of Interstate-4 in Orlando, Florida. Both approaches are based on the traffic state transition probabilities. The HMM approach defines traffic states in a two …