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Full-Text Articles in Engineering

Additive And Interface Engineering Of Lead-Tin Mixed Low-Bandgap Perovskite Solar Cells For Higher Efficiency And Improved Stability, Nabin Ghimire Jan 2021

Additive And Interface Engineering Of Lead-Tin Mixed Low-Bandgap Perovskite Solar Cells For Higher Efficiency And Improved Stability, Nabin Ghimire

Electronic Theses and Dissertations

Lead (Pb) -Tin (Sn) mixed perovskites suffer from large open-circuit voltage (VOC) loss due to the rapid crystallization of perovskite film, creating Sn and Pb vacancies. Such vacancies act as defect sites expediting charge carrier recombination, thus hampering the charge carrier dynamics and optoelectronic properties of perovskite films. In the first project, we focused on the passivation of perovskite surface defects to increase the opencircuit voltage of the 1.25 eV low-bandgap perovskite solar cells by utilizing a trace amount of Phenethylammonium iodide (PEAI) in the perovskite precursor solution as a doping agent. The incorporation of PEAI in perovskite precursors improved …


A Hydrologic Study Of Climate Variability In Arid Region, Abdullah Alzaydani Jan 2021

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 …


Long Term Evaluation Of E. Coli Removal From Stormwater Using Recycled Steel Byproducts, Brenden Olevson Jan 2021

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 Jan 2021

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 …