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Full-Text Articles in Engineering
Heavy Metal Adsorption On Iron Oxide And Iron Oxide-Coated Silica : Macroscopic, Spectroscopic, And Modeling Studies, Ying Xu
Dissertations
To accurately model metal mobility and bioavailability in soils and sediments, systematic sorption studies are needed using representative and well-characterized minerals. Two important surfaces are iron oxide and silica, which are ubiquitous and associated with one another in the environment playing important roles in metal distribution. The objectives of this research are to develop models for predicting speciation and mobility of toxic trace metal ions in groundwater, soils, and sediments when competing ions are present. A model system for soils and sediments, iron oxide-coated silica, was synthesized; the degree of coatings was highly sensitive to the particle size of silica …
A Dynamic Model Of The Human/Cooling System/Clothing/Environment System, Zhengxiang Pu
A Dynamic Model Of The Human/Cooling System/Clothing/Environment System, Zhengxiang Pu
Electronic Theses and Dissertations
The human body compensates well for moderate climatic heat stress, but artificial environments often block or overwhelm physiological defense mechanism. Personal protective equipment (PPE) is one of sources of heat stress. It protects individual from chemical, physical, or biological hazards, but the high thermal insulation and low vapor permeability of PPE may also lead to substantial heat stress. Personal cooling is widely used to alleviate heat stress, especially for those situations where ambient environmental cooling is not economically viable or feasible. It is important to predict the physiological responses of a person wearing PPE with personal cooling to make sure …
Benchmark Studies For Structural Health Monitoring Using Analytical And Experimental Models, Jason Lee Burkett
Benchmark Studies For Structural Health Monitoring Using Analytical And Experimental Models, Jason Lee Burkett
Electronic Theses and Dissertations
The latest bridge inventory report for the United States indicates that 25% of the highway bridges are structurally deficient or functionally obsolete. With such a large number of bridges in this condition, safety and serviceability concerns become increasingly relevant along with the associated increase in user costs and delays. Biennial inspections have proven subjective and need to be coupled with standardized non-destructive testing methods to accurately assess a bridge's condition for decision making purposes. Structural health monitoring is typically used to track and evaluate performance, symptoms of operational incidents, anomalies due to deterioration and damage during regular operation as well …
Navigation Aids In Route Training: Increase Navigation Speed, Decrease Route Retention?, John Holmquist
Navigation Aids In Route Training: Increase Navigation Speed, Decrease Route Retention?, John Holmquist
Electronic Theses and Dissertations
In the case of one car following another to a destination, it is very effective at getting the second vehicle to the destination quickly; however, the driver of the second car may not learn the route. Yet, for individuals, such as firefighters, law enforcement, and military personnel, it is imperative that a route be learned quickly and accurately and that an awareness of the situation is maintained while they traverse the given route. This leads to three questions, (a) will navigation aids affect initial route navigation; (b) will navigation aids affect retention; and (c) will navigation aids affect situation awareness …
Adapting The Modified Cam Clay Constitutive Model To The Computational Analysis Of Dense Granular Soils, Jose Arvelo
Adapting The Modified Cam Clay Constitutive Model To The Computational Analysis Of Dense Granular Soils, Jose Arvelo
Electronic Theses and Dissertations
The computational constitutive Modified Cam Clay Model (MCCM) was developed at Cambridge to study the behavior of clays and has been proven to be effective. In this study, this model is extended to the case of dense sands to analyze the accuracy of the stress-strain behavior. This analysis is based on triaxial test data applied to remolded and compacted sand samples under drained conditions. The laboratory triaxial tests were performed by the Florida Department of Transportation to research the permeability effect in sandy soils compacted up to 95% of maximum unit weight at the optimum moisture content. Each soil sample …
Thermo And Kinetic Studies On The Sorption And Desorption Of Hydrophobic Organic Contaminants In Sediments, Yunzhou Chai
Thermo And Kinetic Studies On The Sorption And Desorption Of Hydrophobic Organic Contaminants In Sediments, Yunzhou Chai
LSU Doctoral Dissertations
This study investigated the correlation of desorption resistance of hydrophobic organic contaminants (HOCs) in sediment and the heterogeneity of sediment organic matter (SOM). The amorphous and condensed phase organic carbon contents were defined by the method of Gustafsson et al. (1997) using thermal oxidation of sediment under 375°C. The desorption-resistant fraction of contaminants in sediments was operationally defined as the fraction that could not be removed by the adsorbent XAD-2. The correlation of the desorption-resistant fraction with sediment organic carbon characteristics was evaluated for both laboratory-inoculated and field-contaminated sediments. No strong correlation between the desorption resistant fraction in laboratory-inoculated sediments …
Mathematical Models For Estimating Volatile Chemical Emissions From Dredging Operations, Kenneth Alexander Fountain
Mathematical Models For Estimating Volatile Chemical Emissions From Dredging Operations, Kenneth Alexander Fountain
LSU Master's Theses
Dredging operations have been a common remediation for contaminated sediment in an effort to reduce the harmful impact on the environment. The objective of this research was to create models used for estimating chemical release to air from remediating the Indiana Harbor and Canal (IHC) as three separate dredging operations; the Dredge Site, Exposed DM CDF, and Ponded CDF. The evaporative flux estimations are based on a two-resistance mass transport path inclusive of both the molecular diffusion in porous media and interfacial airside mass transport resistances. Several chemodynamic algorithms were used in calculating key transport parameters. Laboratory tests were performed …