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Full-Text Articles in Engineering
Mechanically Spliced Precast Bridge Columns, Ted Sjurseth
Mechanically Spliced Precast Bridge Columns, Ted Sjurseth
Electronic Theses and Dissertations
Mechanical bar splices provide an alternative to the traditional method of lap splicing to achieve reinforcement bar continuity in reinforced concrete. Even though mechanical bar splices can be used as new precast column connections to accelerate the bridge construction (ABC), The use of bar couplers in the plastic hinge region of bridge columns is prohibited by the current US codes since the effects of bar couplers on the seismic behavior of columns is not fully investigated. A bridge column including precast columns with couplers located in a high seismic region must be designed to handle large inelastic lateral deformations. The …
Nitrate And Phosphate Removal From Denitrification Bioreactors Using Woodchips, Steel Chips And Agricultural Residue Media, Abdoul Aziz Kouanda
Nitrate And Phosphate Removal From Denitrification Bioreactors Using Woodchips, Steel Chips And Agricultural Residue Media, Abdoul Aziz Kouanda
Electronic Theses and Dissertations
Nitrate and phosphate present in agricultural subsurface drainage water can impact surface water quality thus impacting the environment and human health by causing eutrophication and Methemoglobinemia in young infant. Biological denitrification and phosphate adsorption filters are treatments options that can help reduce nitrate and phosphate concentration from agricultural subsurface drainage before it can be discharged in surface water. The first objective of this dissertation was to determine the Michaelis-Menten kinetics model parameters for nitrate removal in bioreactors using the fresh, aged, and composted woodchips. The composted woodchips achieved a denitrification rate 2.4 times higher than the fresh woodchips which was …
A Speciation Modeling Study Of Heavy Metal Adsorption To Plastic In Municipal Wastewater Treatment Plant Units, Kaitlyn Hague
A Speciation Modeling Study Of Heavy Metal Adsorption To Plastic In Municipal Wastewater Treatment Plant Units, Kaitlyn Hague
Electronic Theses and Dissertations
Microplastics are an emerging concern due to their harmful effect to organisms and their ability to facilitate transport of contaminants including heavy metals. Microplastics can enter the environment through wastewater treatment plants, landfill leachate, and littering. Once in the environment microplastics can be distributed throughout rivers, the ocean, and lakes. In order to understand the adsorption of heavy metals to microplastics a geochemical modeling study was completed using Visual Minteq. Lab tests were completed to better understand what constituents are available in wastewater at four different locations: influent, clarifiers, digesters, and effluent. These constituents were then used to observe how …
Seismic Performance Of Mechanically Spliced Precast Bridge Columns With New Couplers, Evan Greeneway
Seismic Performance Of Mechanically Spliced Precast Bridge Columns With New Couplers, Evan Greeneway
Electronic Theses and Dissertations
Lap splicing is not always the most economical or practical approach to achieve reinforcement bar continuity. Mechanical bar splices, or bar couplers, are one alternative that may be far more practical. Currently, the US codes do not allow for the use of bar couplers in the plastic hinge region for RC members in areas of high seismic activity. There has not been enough research into the couplers behavior when subjected to significant inelastic lateral deformations. The Lohr Structures Laboratory was used to conduct an experimental study on campus of South Dakota State University to evaluate the seismic performance of mechanically …