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Biotreatment And Chemical Speciation Of Lead And Zinc Mine/Mill Wastewater Discharges In Missouri, U.S.A., Mujde Erten-Unal, Bobby G. Wixson
Biotreatment And Chemical Speciation Of Lead And Zinc Mine/Mill Wastewater Discharges In Missouri, U.S.A., Mujde Erten-Unal, Bobby G. Wixson
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Continued mining development in the world's largest lead producing area has generated and increased concern over effective mine water treatment in Missouri's New Lead Belt. A new type of mine/mill wastewater treatment system was constructed which consisted of a tailings pond followed by a series of artificially constructed meandering biotreatment channels and a polishing lagoon. This system provided additional retention time and distance for the removal of heavy metals by abundant aquatic plants and sedimentation. Seasonal field sampling and analytical testing that evaluated the present system confirmed that it provided good treatment for removal of heavy metals within the company …
Slip Modulus Of Frp Sheets Bonded To Concrete, Y. J. Lee, T. E. Boothby, C. E. Bakis, Antonio Nanni
Slip Modulus Of Frp Sheets Bonded To Concrete, Y. J. Lee, T. E. Boothby, C. E. Bakis, Antonio Nanni
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
An analytical tension-stiffening model was developed for fiber-reinforced polymer (FRP) sheets bonded to reinforced concrete based on equilibrium equations and the assumption of linear behavior between bond stress and slip. Experimental measurements were made on small- and large-scale specimens. For the small-scale specimens, the primer coat thickness (adhesive thickness between concrete and FRP sheet) was varied for each specimen. By comparisons of the experimental data to the analytical results, the slip modulus at the concrete/FRP sheet and concrete/steel interface was established at the service load level. From this study, it was found that primer coat thickness has a modest influence …
Evaluation Of Bond Using Frp Rods With Axisymmetric Deformations, Mesfer M. Al-Zahrani, Salah U. Al-Dulaijan, Antonio Nanni, Charles E. Bakis, Thomas E. Boothby
Evaluation Of Bond Using Frp Rods With Axisymmetric Deformations, Mesfer M. Al-Zahrani, Salah U. Al-Dulaijan, Antonio Nanni, Charles E. Bakis, Thomas E. Boothby
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This paper presents experimental results obtained with the direct pull-out test using machined and wrapped glass/vinyl ester, carbon/vinyl ester, and carbon/epoxy FRP rods with axisymmetric lugs. The typical results are given as nominal shear stress vs. free- and loaded-end slip. Experimental results obtained from strain probes used during the pull-out test are presented as shear stress vs. strain. Machined glass/vinyl ester FRP rods with embedded lengths including five and 10 lugs, and different lug widths and heights were studied. The failure mode consisted of the shearing off of the lugs without concrete damage. Four concrete mixtures with strengths ranging from …
Membrane Process For Biological Treatment Of Contaminated Gas Streams, Sarina J. Ergas, Leslee Shumway, Mark W. Fitch, Jeffrey J. Neemann
Membrane Process For Biological Treatment Of Contaminated Gas Streams, Sarina J. Ergas, Leslee Shumway, Mark W. Fitch, Jeffrey J. Neemann
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
A Hollow Fiber Membrane Bioreactor Was Investigated for Control of Air Emissions of Biodegradable Volatile Organic Compounds (VOCs). in the Membrane Bioreactor, Gases Containing VOCs Pass through the Lumen of Microporous Hydrophobic Hollow Fiber Membranes. Soluble Compounds Diffuse through the Membrane Pores and Partition into a VOC Degrading Biofilm. the Hollow Fiber Membranes Serve as a Support for the Microbial Population and Provide a Large Surface Area for VOC and Oxygen Mass Transfer. Experiments Were Performed to Investigate the Effects of Toluene Loading Rate, Gas Residence Time, and Liquid Phase Turbulence on Toluene Removal in a Laboratory-Scale Membrane Bioreactor. Initial …
Biological Fixed-Film Systems, Mark W. Fitch, Jeffrey B. Murphy, Stephen S. Sowell
Biological Fixed-Film Systems, Mark W. Fitch, Jeffrey B. Murphy, Stephen S. Sowell
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The Microbiological Degradation of Wastewater and its Application using a Fixed-Film Reactor is Reviewed. the Technical and Technological Characteristics, as Well as the Efficiency of Nitrification and Denitrification Processes Were Taken into Consideration. the Review Elucidated the Experimental Measurements of Effective Diffusive Permeabilities and Effective Diffusion Coefficients of Biofilms.
Natural Treatment And On-Site Processes, Kevin D. White, Joel Gerard Burken
Natural Treatment And On-Site Processes, Kevin D. White, Joel Gerard Burken
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The Natural Treatment Systems, Which is Divided into Land-Treatment, Wetland, Aquatic, Onsite and Small Community, and Phytoremediation Systems, Are Discussed. This Include the Free Water Surface Constructed Wetlands, Subsurface Flow Constructed Wetlands, Vertical Flow Constructed Wetlands,ponds, Floating Aquatic Plant Systems, Solar Aquatic Systems, Small Treatment Systems, and In-Ground Disposals.
Liquefaction Of Silts And Silt-Clay Mixtures, Tianqiang Guo, Shamsher Prakash
Liquefaction Of Silts And Silt-Clay Mixtures, Tianqiang Guo, Shamsher Prakash
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Low plasticity silts and silty clays occur extensively in the central United States. For evaluating their liquefaction potential during an earthquake, no guidelines are available based on their density, void ratio, plasticity index, standard penetration values, or any other simple soil property. Their liquefaction behavior is not properly understood at present and is often confused with that of sand-silt mixtures. Pore water pressures and liquefaction in silt and silt-clay mixtures are discussed, and the influences of plasticity index on their cyclic strength are reviewed critically. It is concluded that considerable additional work is needed to fully understand the liquefaction behavior …
Optimized Calibration For Unsteady Flow Modeling Using A Genetic Algorithm, Daniel Sanchez, Jerome A. Westphal
Optimized Calibration For Unsteady Flow Modeling Using A Genetic Algorithm, Daniel Sanchez, Jerome A. Westphal
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The calibration of an unsteady flow model generally relies on the estimation of roughness coefficients, which act as descriptors of friction resistance along the channel. Here an optimized procedure is implemented by incorporating a genetic algorithm (GA) to automate the process. This approach is suitable because discrete parameters are considered. The target is a one-dimensional unsteady flow model in which the roughness coefficient is allowed to vary not only along the river axis, but also dynamically with discharge. The objective function is the root mean square of the difference between measured and computed water levels at a given cross section. …
Stage-Discharge Relations On The Middle Mississippi River, Jerome A. Westphal, D. B. Thompson, Glendon Taylor Stevens, C. N. Strauser
Stage-Discharge Relations On The Middle Mississippi River, Jerome A. Westphal, D. B. Thompson, Glendon Taylor Stevens, C. N. Strauser
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Based on measurements made on the Middle Mississippi River during the 1993 flood, stage-discharge relations for the rating curve are not single-valued. Analyses of these data suggest that the range of flow rates at a given stage is larger than that attributable to measurement replication error alone. Patterns of stage-discharge measurements also imply a tendency toward hysteresis. However, neither changes in stage nor changes in flow rate correlate with short-term scour and fill at gauging sites.
Crippling Capacity Of Web Elements With Openings, Roger A. Laboube, W. W. Yu, S. U. Deshmukh, C. A. Uphoff
Crippling Capacity Of Web Elements With Openings, Roger A. Laboube, W. W. Yu, S. U. Deshmukh, C. A. Uphoff
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Commonly used cold-formed steel sections utilized as either wall studs or floor joists contain web holes. The web holes may be factory punched or field cut. Because the Specification for the Design of Cold-Formed Steel Structural Members does not address the potential impact that a web hole can have on the structural integrity of the cold-formed steel member, research was necessary. Researchers at the University of Missouri-Rolla have explored the behavior of a flexural member that possesses a web hole. The scope of the UMR research includes flexure, shear, web crippling, and combinations thereof. The present paper will summarize the …