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Full-Text Articles in Engineering

The Effect Of Edge-Of-Field Nutrient Management Practices On Microbial Concentrations In Subsurface Drainage Water And The Associated Risk Of Antibiotic Resistance Dissemination, Sara Mardani Jan 2019

The Effect Of Edge-Of-Field Nutrient Management Practices On Microbial Concentrations In Subsurface Drainage Water And The Associated Risk Of Antibiotic Resistance Dissemination, Sara Mardani

Electronic Theses and Dissertations

Many in-field and edge-of-field management practices have been used to reduce nutrient loads from agricultural fields. The denitrification woodchip bioreactor (WB) is one edgeof- field management practice that has proven to be effective in removing nitrate from subsurface drainage water. The success in nitrate removal achieved with WBs has raised interest in expanding their capabilities for removing other agricultural pollutants, including phosphorus, by using other types of media like phosphorus-sorbing filters or combining these filters with woodchips to remove both nitrate and phosphorus as dual-nutrient removal systems. Despite the extensive research done on WBs and nutrient filter materials, little consideration …


Field And Numerical Study For Deteriorating Precast Double-Tee Girder Bridges, Brian Kidd Jan 2019

Field And Numerical Study For Deteriorating Precast Double-Tee Girder Bridges, Brian Kidd

Electronic Theses and Dissertations

Two deteriorating DT bridges in South Dakota, both over 30-years old, were field tested with a static and dynamic load. From the recorded strain values, the liveload distribution factors (LLDFs) and dynamic load allowance (IM) factors were calculated. The AASHTO LRFD and AASHTO Standard Specifications were compared with the field LLDFs and IMs. It was determined that the AASHTO LRFD Specifications were conservative for deteriorating DT girder bridges, with two exceptions. The AASHTO Standard codified LLDFs were significantly higher than the field LLDFs in all cases. The AASHTO LRFD and AASHTO Standard specifications were conservative when calculating the IM factors …


Natural Sunlight Photodegradation Of Halogenated Disinfection Byproducts In Water, Ibrahim Abusallout Jan 2019

Natural Sunlight Photodegradation Of Halogenated Disinfection Byproducts In Water, Ibrahim Abusallout

Electronic Theses and Dissertations

Disinfection byproducts (DBPs) presence in wastewater effluents and receiving waters may impact the quality of drinking water during water reuse practices. Natural solar photolysis is one of the biogeochemical processes that may lead to decreased DBPs concentrations in water. The purpose of this dissertation is to determine the fate of chlorinated, brominated and iodinated DBPs in surface water by natural sunlight photolysis and investigate the use of solar-based advanced oxidation processes (AOPs) for removal of DBPs in water. Total organic halogen (TOX) was used to measure total chlorinated- (TOCl), brominated- (TOBr) and iodinated-DBPs (TOI) in water. The first objective was …


Repairable Moment-Resisting Steel Buildings, Heath William Pederson Jan 2019

Repairable Moment-Resisting Steel Buildings, Heath William Pederson

Electronic Theses and Dissertations

Current seismic design codes ensure life safety for buildings, but structural members may significantly yield or even fail under strong earthquakes. A new design approach is to implement connections that localize the yielding and failure to fuses. A more sophisticated approach is to be able to replace the fuses after the event. The present study was carried out to develop repairable moment-resisting (MR) connections for steel buildings and to investigate their seismic performance through nonlinear finite element analyses (FEA). Two details were proposed using buckling restrained fuses (BRFs) and buckling restrained reinforcement (BRR). Test data was collected from the literature …


A Study Of The Effect Of Heat Treatment On 3d Printed Pla Impact Strength, Suresh Thota Jan 2019

A Study Of The Effect Of Heat Treatment On 3d Printed Pla Impact Strength, Suresh Thota

Electronic Theses and Dissertations

Environmental conditions have a significant effect on the mechanical properties of various materials. Environmental parameters such as temperature and humidity have a major impact on mechanical properties of materials such as compressive strength, tensile strength, bending strength and impact strength. The purpose of this research is to study how temperature and humidity affect the impact strength of 3D printed PLA plastic. Impact strength is the ability of a material to absorb energy subjected to an impact load by a pendulum. In this research, 3D printing was employed to produce PLA specimens which were later used for different experimental testings. For …


Pilot Scale Evaluation Of E. Coli Filtration Removal From Stormwater Using Recycled Steel, Jason Neville Jan 2019

Pilot Scale Evaluation Of E. Coli Filtration Removal From Stormwater Using Recycled Steel, Jason Neville

Electronic Theses and Dissertations

Microbial pathogens are considered one of the most important pollutants in regards to surface waters such as coastal waters, rivers and urban estuaries. Escherichia Coli (E. coli) is a bacterial microorganism found in the guts of humans and some animals that if ingested can cause diarrhea, severe stomach cramps, and vomiting. E. coli carried by stormwater runoff can deteriorate water quality of receiving bodies of water. It is necessary to develop technologies to remove E. coli from stormwater runoff to protect surface waters and public health. The use of steel byproducts as an adsorption technology is an emerging stormwater treatment …


Variability Of E. Coli In Streambed Sediments And Its Implication For Water Quality, Sadia Salam Jan 2019

Variability Of E. Coli In Streambed Sediments And Its Implication For Water Quality, Sadia Salam

Electronic Theses and Dissertations

Fecal indicator bacteria (FIB), including E. coli, are the number one cause of water quality impairments in the United States according to the USEPA. FIB are used as a predictor to identify the possible presence of pathogens in waterbodies. E. coli is a useful indicator of gastrointestinal (GI) related illnesses from contact with fresh water. While surface water is routinely monitored for water quality, streambed sediments are rarely considered as a source of FIB to the overlying water column. This study focuses on understanding the variation of E. coli concentrations in streambed sediments and the potential impact of sediment sources …


Escherichia Coli Removal From Stormwater Using Steel Chips Filter, Peng Dai Jan 2019

Escherichia Coli Removal From Stormwater Using Steel Chips Filter, Peng Dai

Electronic Theses and Dissertations

Media filtration has received increasing attention as an effective technology that can facilitate the removal of particles and dissolved pollutions in the stormwater. However, most traditional media filtration systems are generally ineffective in removing bacteria, causing pollution of groundwater and receiving surface water. In this study, recycled steel chips were evaluated as low-cost filter materials for bacterial removal from stormwater. Laboratory column experiments were conducted to evaluate the impact of steel chips particle size, flow rate, initial E.coli concentration, pH, natural organic matter (NOM), steady and intermittent flow on E.coli removal. The results showed that E.coli removal decreased from 99.4% …


An Initial Exploration Of The 2005 Iowa Rural Interstate Speed Limit Increase Using Linear Regression, Thomas Ryan Cook Jan 2019

An Initial Exploration Of The 2005 Iowa Rural Interstate Speed Limit Increase Using Linear Regression, Thomas Ryan Cook

Electronic Theses and Dissertations

Speed limit increases, particularly on interstates have been studied and researched many times over the course of the last 50 years in the United States. These research efforts began after the implementation of the National Maximum Speed Law (NMSL), which reduced all speed limits to a maximum of 55-mph. In the years that followed, this restriction was relaxed to 65-mph with the Surface Transportation and Uniform Relocation Assistance Act (STURAA) and ultimately repealed later by the National Highway System Designation Act (NHSDA). Since the repeal, states reacted in myriad of ways and many studies documented the changes of those reactions. …


Stream Flow Analysis Of The Big Sioux River Just South Of Brookings, South Dakota, Samuel Ruppert Jan 2019

Stream Flow Analysis Of The Big Sioux River Just South Of Brookings, South Dakota, Samuel Ruppert

Electronic Theses and Dissertations

Floods are the most common type of natural disaster in the world and one of the most damaging. Changes in climate conditions such as precipitation and temperature are causing changes in stream flow. This means that in order to better understand flooding and possibly develop a system for making flood predictions, stream flow needs to be analyzed more closely. The primary objective of this thesis is to analyze the Big Sioux River just south of Brookings, South Dakota, both annually and seasonally. The United States Geological Survey (USGS) has stream gauges placed in rivers and streams all over the United …