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- Adsorption (1)
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Articles 1 - 12 of 12
Full-Text Articles in Engineering
Quantification Of Climate Variability And Extreme Events In The Great Plains, Angelinah Ntsieng Rasoeu
Quantification Of Climate Variability And Extreme Events In The Great Plains, Angelinah Ntsieng Rasoeu
Electronic Theses and Dissertations
Climate variability and extreme events continue to worsen resulting in significant impacts to society and the environment. Quantifying precipitation variability, streamflow, and extreme events at local scale is crucial for local planning and management due to spatial and temporal precipitation variability which influences streamflow and thus, water resources. This study uses statistical tools to analyze 1895-2019 (125 years) of historical precipitation data to examine how long-term precipitation varies annually, seasonally, and monthly, and create climate classifications. The results show that annual precipitation is increasing linearly over time ranging from 13.2 in (1976) to 43.1 in (2010) and 5 climate classes …
An Exploration Of The Application Of Spatial Network Screening Methods On Iowa Rural Road Crashes, Rosanna Maria Novellino Suarez
An Exploration Of The Application Of Spatial Network Screening Methods On Iowa Rural Road Crashes, Rosanna Maria Novellino Suarez
Electronic Theses and Dissertations
Safety on the roadway system is important due to its usage on mobility and accessibility, especially on rural roads in the state of Iowa. Single vehicle run off road crashes have been increasing in the United States and studies and research has increased due to the concern with those. For this effort, a spatial-temporal method of traffic safety network screening is utilized in order to evaluate the concerning type of crashes in particular locations. The study of single vehicle run off road crashes using the proposed method is important since distributions and clusters of crashes along roadways can be observed …
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 …
A Hydrologic Climate Study For An Arid Region, Ali Alsubeai
A Hydrologic Climate Study For An Arid Region, Ali Alsubeai
Electronic Theses and Dissertations
Water is the most precious natural resource in arid regions due to the limitation of water resources, expanding population, and increasing volumes of industrial and domestic waste. The purpose of this research was to evaluate methods to estimate water quantity in an arid region. The research consisted of three separate studies. In the first study, hydrologic models used to estimate water quantity were evaluated for suitability of use in arid regions. Most hydrologic models that have been used in arid regions were originally developed for humid regions. Rainfall events in arid regions can be characterized as short-term, high intense rainstorms …
Laboratory Measurements Of Bed Shear Stress In Open Channel Flow And Soil Erosion Rate In Cohesive Soils, Gunnar Schurmann Kern
Laboratory Measurements Of Bed Shear Stress In Open Channel Flow And Soil Erosion Rate In Cohesive Soils, Gunnar Schurmann Kern
Electronic Theses and Dissertations
The relationship between soil erosion rate and bed shear stress is an important problem in sediment transport and scour. However, reliable measurements of the soil erosion function are challenging, both in the field and in the laboratory. The objective of this study is to investigate an experimental setup for conducting bed shear stress and soil erosion rate measurements using an open channel flume with a rough bed. These experiments were performed in an A-8 Hydraulic Channel with a fixed gravel bed. The flow discharge was kept constant at 0.158 ft.3/s, and bed shear stress was varied by changing the channel …
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 Study Of Geographic Information System-Based Watershed Processing For Hydrologic Analysis Of Ungauged Watersheds, Philip Adanbe Adalikwu
A Study Of Geographic Information System-Based Watershed Processing For Hydrologic Analysis Of Ungauged Watersheds, Philip Adanbe Adalikwu
Electronic Theses and Dissertations
The increasing application of geographic information system (GIS) technology in watershed modeling makes is necessary to further evaluate its impacts on runoff characteristics as a basis for improved hydrologic analysis in ungauged watersheds. Experts in the field of water resources and hydrology have recommended the practice of subdivision when modeling a watershed, and the use of observed data from hydrologically similar watershed to calibrate and validate an ungauged watershed’s model. However, previous studies have failed to adequately address the issues of watershed heterogeneity, spatial and temporal variability in physical parameters, GIS data resolution issues, including artifacts in automated extraction of …
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 …
A Hydrologic Study Of Climate Variability In Arid Region, Abdullah Alzaydani
A Hydrologic Study Of Climate Variability In Arid Region, Abdullah Alzaydani
Electronic Theses and Dissertations
Climate variability is an important subject to study. It is the change of climate over a long time, which could have a positive or negative impact on humans, soil, and wildlife. Many environments, such as arid environment could be affected by climate variability. The research goal is studying and examining climate variability in arid environment. The research includes three different studies. The first study includes reviewing and understanding of climate variability over extended time through existing studies in arid environments. In addition, this study includes knowledge about climate negative or positive impact on the environment. This study will be reviewing …
Evaluating And Predicting The Risk Of Algal Blooms In A Freshwater Lake Through A 4-Dimensional Approach: A Case Study On Lake Mitchell, Sumit Kumar Ghosh
Evaluating And Predicting The Risk Of Algal Blooms In A Freshwater Lake Through A 4-Dimensional Approach: A Case Study On Lake Mitchell, Sumit Kumar Ghosh
Electronic Theses and Dissertations
Excessive algal growth in freshwater lakes can negatively impact ecosystems, recreation, and human health. Though algae are a natural part of freshwater ecosystems, elevated nutrient loading from anthropogenic and natural sources can lead to algal blooms. Both algae and blue-green algae (BGA) are responsible for algal blooms; however, BGA (cyanobacteria) is more dangerous. The first objective of this research was to prepare a conceptual model to understand how various environmental variables affect algae. This conceptual model was used to choose the environmental variables that help increase or decrease algae in the water environment. The second objective was to develop empirical …
Long Term Evaluation Of E. Coli Removal From Stormwater Using Recycled Steel Byproducts, Brenden Olevson
Long Term Evaluation Of E. Coli Removal From Stormwater Using Recycled Steel Byproducts, Brenden Olevson
Electronic Theses and Dissertations
Stormwater runoff often carries a variety of pollutants and pathogens that can endanger public health and wildlife. One contaminant of concern often highlighted in stormwater quality is Escherichia Coli (E.Coli) because its presence indicates microbial contamination in water. Different types of media filtration are being studied to reduce contaminant concentrations in stormwater. In this study, steel byproducts were examined as a potential material to use in media filtration to remove E. Coli and other contaminants from stormwater. Batch scale studies were conducted in laboratory to evaluate the E. Coli removal potential of steel chips and steel slag over a 24-hour …
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 …