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Full-Text Articles in Engineering
Modeling Flocculation And Deflocculation Processes Of Cohesive Sediments, Xiaoteng Shen
Modeling Flocculation And Deflocculation Processes Of Cohesive Sediments, Xiaoteng Shen
Dissertations, Theses, and Masters Projects
The transport and fate of cohesive sediments are responsible for many engineering, environmental, economic and policy issues that relate to, for example, siltation and dredging in navigation channels, water quality, water turbidity, pollutant transports, and biological ecosystem responses. Our current understanding, however, is insufficient to conduct accurate quantitative predictions of these processes. This is because the cohesive particles in natural waters will flocculate, which determines the settling, and thus the deposition behaviors. The simulation of flocculation processes is a primary challenge since the time variation of Floc Size Distribution (FSD) is controlled by a partial differential equation that also contains …
Ultrasonic Guided Wave Interpretation For Structural Health Inspections, Jill Paisley Bingham
Ultrasonic Guided Wave Interpretation For Structural Health Inspections, Jill Paisley Bingham
Dissertations, Theses, and Masters Projects
Structural Health Management (SHM) combines the use of onboard sensors with artificial intelligence algorithms to automatically identify and monitor structural health issues. A fully integrated approach to SHM systems demands an understanding of the sensor output relative to the structure, along with sophisticated prognostic systems that automatically draw conclusions about structural integrity issues. Ultrasonic guided wave methods allow us to examine the interaction of multimode signals within key structural components. Since they propagate relatively long distances within plate- and shell-like structures, guided waves allow inspection of greater areas with fewer sensors, making this technique attractive for a variety of applications.;This …
An Evaluation Of Norovirus Persistence In Estuarine Water And Of Methods For Its Detection In Treated Sewage Effluent, Margaret H. Fagan
An Evaluation Of Norovirus Persistence In Estuarine Water And Of Methods For Its Detection In Treated Sewage Effluent, Margaret H. Fagan
Dissertations, Theses, and Masters Projects
No abstract provided.
Laboratory Oxide Coatings: Physical Form And Surface Chemistry, Kea U. Duckenfield
Laboratory Oxide Coatings: Physical Form And Surface Chemistry, Kea U. Duckenfield
Dissertations, Theses, and Masters Projects
The impact of dissolved trace metals on aquatic ecosystems and human health is controlled by sorption, i.e., binding to the surfaces of environmental particles. Since many environmental particles are coated with highly reactive substances, and since discrepancies in trace metal sorption behavior persist between oxides developed in the laboratory and environmental oxide phases, it was hypothesized that the physical form of oxide coatings may influence the chemical properties of the coated particle. Therefore, relationships between the physical forms of several different Fe(III) oxide coatings and the Cu(II) sorption behavior of the coated solids were investigated in comparison with the component …
A Two-Component Aggregation Model, Thomas A. Chisholm Jr
A Two-Component Aggregation Model, Thomas A. Chisholm Jr
Dissertations, Theses, and Masters Projects
An aggregation model which allows specification of primary particle size, density, and fractal dimension for two different particle types was written. Three stickiness values are used, the stickiness of each particle type to itself and the stickiness between particle types. Aggregation mechanisms considered include differential settling and turbulent shear. The model is used in three forms. In its simplest form, it operates on a closed system with aggregates breaking up when their size approaches the Kolmogorov scale. If the system begins with two types of primary particles, larger aggregates have uniform composition. A second version of the model includes removal …
Laboratory And Field Investigations To Determine The Chemical Factors Affecting Zinc And Iron Transport At An Industrial Waste Facility, Michael Lawrence Chasey
Laboratory And Field Investigations To Determine The Chemical Factors Affecting Zinc And Iron Transport At An Industrial Waste Facility, Michael Lawrence Chasey
Dissertations, Theses, and Masters Projects
No abstract provided.
Resuspension Behavior Of Natural Estuarine Sediments, Chang-Hee Lee
Resuspension Behavior Of Natural Estuarine Sediments, Chang-Hee Lee
Dissertations, Theses, and Masters Projects
The resuspension behavior of natural estuarine sediments was studied using the VIMS Sea Carousel, a benthic annular flume. The bed shear stresses produced by the flume were measured by a hot-film sensor mounted flush on the bottom of a laboratory version of the Carousel under a clear-water and flat-bottom condition. Measurements showed a reasonably uniform bed shear stress across the channel and agreed with the relationship &\tau\sb{lcub}\rm b{rcub}=0.011\Omega\sp{lcub}1.69{rcub},& where &\Omega& = ring speed (rpm) and &\tau\sb{lcub}\rm b{rcub}& = spatially-averaged bed shear stress (N/m&\sp2&), predicted from a previous numerical study. Thus, the &\tau\sb{lcub}\rm b{rcub}& was used as a bed shear stress …
Interaction Of Long Waves And Nearshore Barred Topography--A Mechanism Of Bar Migration, Chang-Shik Kim
Interaction Of Long Waves And Nearshore Barred Topography--A Mechanism Of Bar Migration, Chang-Shik Kim
Dissertations, Theses, and Masters Projects
It has been widely observed in nature that longshore bar topography changes profile in the onshore-offshore direction. It is common for some bars to migrate onshore during post-storm phases and offshore during storms. Although the behavior of submarine bars has been widely reported, its mechanisms and forcings are far less clear. to determine the mechanism for bar migration or for the persistence of bar systems, a numerical model is developed, which accounts for the mass transport velocities in the bottom boundary layer induced by a family of combined long waves at surf-beat frequencies and wind waves. The present approach simulates …