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Full-Text Articles in Civil Engineering
Assessment Of Nitrifying Bacteria In Massard Plant Using Molecular Tools, Jennifer Puanani Holmes-Smith
Assessment Of Nitrifying Bacteria In Massard Plant Using Molecular Tools, Jennifer Puanani Holmes-Smith
Civil Engineering Undergraduate Honors Theses
The discharge of nutrients (such as nitrogen and phosphorus) from wastewater treatment plants (WWTP) has become an increasingly important issue in the United States. Ammonia (NH3) is a common contaminant found in domestic wastewater and agricultural runoff. It can cause toxicity in fish if left untreated. The United States Environmental Protection Agency (EPA) recommends low national criteria for ammonia limits in freshwater. With these greater restrictions, ammonia-nitrogen limit compliance (5 mg/L) has become an issue at the Massard WWTP in Fort Smith, Arkansas. The purpose of this research is to assess the ammonia removal in the Massard WWTP in order …
Temperature Sensitivity Of Foamed Warm Mix Asphalt, Ryan Michael Hagedorn
Temperature Sensitivity Of Foamed Warm Mix Asphalt, Ryan Michael Hagedorn
Civil Engineering Undergraduate Honors Theses
Foamed warm mix asphalt (WMA) is a technology that is beginning to be utilized across the United States. Often, producers are placing foamed WMA at decreased temperatures without fully understanding the properties of this relatively new product. By studying the volumetric properties of laboratory produced foamed WMA, this study sought to better understand the temperature sensitivity of foamed WMA and the potential factors that contribute to this sensitivity. Two mix designs containing primarily limestone aggregate were tested using differing binder grades. It was determined that binder grade, binder source and potentially the inclusion of recycled asphalt pavement all influence how …
Dynamic Excitation Related Uncertainty In Ambient Vibration Testing Of A Truss Bridge, Ryan T. Dufour
Dynamic Excitation Related Uncertainty In Ambient Vibration Testing Of A Truss Bridge, Ryan T. Dufour
Civil Engineering Undergraduate Honors Theses
The aging and deteriorating state of bridges in the US, along with the many limitations of the visual inspection data that is used for assessing and evaluating their condition, have provided motivation for research on experimental methods to quantitatively describe and evaluate their in-situ performance and condition. Ambient vibration testing is one such global characterization approach that has been widely explored due to its low cost and ease of implementation for in-service bridges. The testing is used to identify the modal properties of the structure, typically the natural frequencies, mode shapes, and damping ratios. Although ambient vibration testing has been …
Examination Of Nitrogen To Phosphorus Ratio In Nutrient Removal From Wastewater Through Chlorella Vulgaris, Courtney L. Hill
Examination Of Nitrogen To Phosphorus Ratio In Nutrient Removal From Wastewater Through Chlorella Vulgaris, Courtney L. Hill
Civil Engineering Undergraduate Honors Theses
A need for phosphorus removal is becoming increasingly evident as some wastewater treatment plants struggle to meet wastewater effluent nutrient requirements. High nutrient levels in wastewater effluents have also caused ongoing tension between the state of Oklahoma and Arkansas regarding the pollution of the Illinois River. This research seeks to establish the relationship between nitrogen to phosphorus ratio in wastewater and the level of nutrient reduction using Chlorella vulgaris. Seed cultures of Chlorella vulgaris were added into solutions with various ratios of nitrate to phosphate representative of treated domestic wastewater and the removal of nitrogen and phosphorus were measured in …
Shear Capacity Of Prestressed Lightweight Self-Consolidating Concrete, Micah Alan Wyssmann
Shear Capacity Of Prestressed Lightweight Self-Consolidating Concrete, Micah Alan Wyssmann
Civil Engineering Undergraduate Honors Theses
In prestressed members, self-consolidating concrete (SCC) has in some cases exhibited lower shear capacity than conventional concrete, which has been attributed to decreased aggregate interlock. However, little data is currently available to assess whether use of lightweight aggregate in prestressed SCC beams has further impact on aggregate interlock and shear strength. This study measured the shear capacity of six prestressed beams made from three different concrete mixtures: lightweight self-consolidating concrete (LWSCC) with expanded shale aggregate, LWSCC with expanded clay aggregate, and control normal weight SCC with limestone aggregate. Predicted shear capacities were determined based on current ACI Building Code and …
Evaluation Of The Effects Of Dynamic Excitation Characteristics On Ambient Vibration Test Results For A Multi-Girder Bridge, Gibran Santana
Evaluation Of The Effects Of Dynamic Excitation Characteristics On Ambient Vibration Test Results For A Multi-Girder Bridge, Gibran Santana
Civil Engineering Undergraduate Honors Theses
The bridge population in the US is currently aging and deteriorating rapidly. More than 30% of the bridges across the country have already exceeded their expected design life. Therefore, it is important to develop more timely, reliable and quantitative alternatives to the qualitative visual inspection approach that is currently used to evaluate these structures. One experimental approach that has been researched extensively for quantitatively characterize bridges is Ambient Vibration Testing (AVT) also known as Operational Modal Analysis (OMA). In this approach, the vibration responses of a structure due to unmeasured and uncontrolled ambient dynamic excitation are measured and analyzed to …