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- All Subjects: engineering
- Creators: Rogers, Bradley
- Creators: Engineering Programs
Description
The object of this study was a 26 year old residential Photovoltaic (PV) monocrystalline silicon (c-Si) power plant, called Solar One, built by developer John F. Long in Phoenix, Arizona (a hot-dry field condition). The task for Arizona State University Photovoltaic Reliability Laboratory (ASU-PRL) graduate students was to evaluate the power plant through visual inspection, electrical performance, and infrared thermography. The purpose of this evaluation was to measure and understand the extent of degradation to the system along with the identification of the failure modes in this hot-dry climatic condition. This 4000 module bipolar system was originally installed with a 200 kW DC output of PV array (17 degree fixed tilt) and an AC output of 175 kVA. The system was shown to degrade approximately at a rate of 2.3% per year with no apparent potential induced degradation (PID) effect. The power plant is made of two arrays, the north array and the south array. Due to a limited time frame to execute this large project, this work was performed by two masters students (Jonathan Belmont and Kolapo Olakonu) and the test results are presented in two masters theses. This thesis presents the results obtained on the north array and the other thesis presents the results obtained on the south array. The resulting study showed that PV module design, array configuration, vandalism, installation methods and Arizona environmental conditions have had an effect on this system's longevity and reliability. Ultimately, encapsulation browning, higher series resistance (potentially due to solder bond fatigue) and non-cell interconnect ribbon breakages outside the modules were determined to be the primary causes for the power loss.
ContributorsBelmont, Jonathan (Author) / Tamizhmani, Govindasamy (Thesis advisor) / Henderson, Mark (Committee member) / Rogers, Bradley (Committee member) / Arizona State University (Publisher)
Created2013
Description
While the piezoelectric effect has been around for some time, it has only recently caught interest as a potential sustainable energy harvesting device. Piezoelectric energy harvesting has been developed for shoes and panels, but has yet to be integrated into a marketable bicycle tire. For this thesis, the development and feasibility of a piezoelectric tire was done. This includes the development of a circuit that incorporates piezoceramic elements, energy harvesting circuitry, and an energy storage device. A single phase circuit was designed using an ac-dc diode rectifier. An electrolytic capacitor was used as the energy storage device. A financial feasibility was also done to determine targets for manufacturing cost and sales price. These models take into account market trends for high performance tires, economies of scale, and the possibility of government subsidies. This research will help understand the potential for the marketability of a piezoelectric energy harvesting tire that can create electricity for remote use. This study found that there are many obstacles that must be addressed before a piezoelectric tire can be marketed to the general public. The power output of this device is miniscule compared to an alkaline battery. In order for this device to approach the power output of an alkaline battery the weight of the device would also become an issue. Additionally this device is very costly compared to the average bicycle tire. Lastly, this device is extreme fragile and easily broken. In order for this device to become marketable the issues of power output, cost, weight, and durability must all be successfully overcome.
ContributorsMalotte, Christopher (Author) / Madakannan, Arunachalanadar (Thesis advisor) / Srinivasan, Devarajan (Committee member) / Rogers, Bradley (Committee member) / Arizona State University (Publisher)
Created2012
Description
Potential induced degradation (PID) due to high system voltages is one of the major degradation mechanisms in photovoltaic (PV) modules, adversely affecting their performance due to the combined effects of the following factors: system voltage, superstrate/glass surface conductivity, encapsulant conductivity, silicon nitride anti-reflection coating property and interface property (glass/encapsulant; encapsulant/cell; encapsulant/backsheet). Previous studies carried out at ASU's Photovoltaic Reliability Laboratory (ASU-PRL) showed that only negative voltage bias (positive grounded systems) adversely affects the performance of commonly available crystalline silicon modules. In previous studies, the surface conductivity of the glass surface was obtained using either conductive carbon layer extending from the glass surface to the frame or humidity inside an environmental chamber. This thesis investigates the influence of glass surface conductivity disruption on PV modules. In this study, conductive carbon was applied only on the module's glass surface without extending to the frame and the surface conductivity was disrupted (no carbon layer) at 2cm distance from the periphery of frame inner edges. This study was carried out under dry heat at two different temperatures (60 °C and 85 °C) and three different negative bias voltages (-300V, -400V, and -600V). To replicate closeness to the field conditions, half of the selected modules were pre-stressed under damp heat for 1000 hours (DH 1000) and the remaining half under 200 hours of thermal cycling (TC 200). When the surface continuity was disrupted by maintaining a 2 cm gap from the frame to the edge of the conductive layer, as demonstrated in this study, the degradation was found to be absent or negligibly small even after 35 hours of negative bias at elevated temperatures. This preliminary study appears to indicate that the modules could become immune to PID losses if the continuity of the glass surface conductivity is disrupted at the inside boundary of the frame. The surface conductivity of the glass, due to water layer formation in a humid condition, close to the frame could be disrupted just by applying a water repelling (hydrophobic) but high transmittance surface coating (such as Teflon) or modifying the frame/glass edges with water repellent properties.
ContributorsTatapudi, Sai Ravi Vasista (Author) / Tamizhmani, Govindasamy (Thesis advisor) / Srinivasan, Devarajan (Committee member) / Rogers, Bradley (Committee member) / Arizona State University (Publisher)
Created2012
Description
This report presents the effects and analysis of the effects of Pulsed-Gas Metal Arc Welding's (P-GMAW) on Lean Duplex stainless steel. Although the welding of Duplex and Super Duplex Stainless steels have been well documented in both the laboratory and construction industry, the use of Lean Duplex has not. The purpose for conducting this research is to ensure that the correct Ferrite-Austenite phase balance along with the correct welding procedures are used in the creation of reactor cores for new construction nuclear power generation stations. In this project the effects of Lincoln Electrics ER-2209 GMAW wire are studied. Suggestions and improvements to the welding process are then proposed in order to increase the weldability, strength, gas selection, and ferrite count. The weldability will be measured using X-Ray photography in order to determine if any inclusions, lack of fusion, or voids are found post welding, along with welder feedback. The ferritic point count method in accordance with ASTM A562-08, is employed so that the amount of ferrite and austenite can be calculated in the same manor that is currently being used in industry. These will then be correlated to the tensile strength and impact toughness in the heat-affected zone (HAZ) of the weld based on the ASTM A923 testing method.
ContributorsCarter, Roger (Author) / Rogers, Bradley (Thesis advisor) / Gintz, Jerry (Committee member) / Georgeou, Trian (Committee member) / Arizona State University (Publisher)
Created2012
Description
The action/adventure game Grad School: HGH is the final, extended version of a BME Prototyping class project in which the goal was to produce a zombie-themed game that teaches biomedical engineering concepts. The gameplay provides fast paced, exciting, and mildly addicting rooms that the player must battle and survive through, followed by an engineering puzzle that must be solved in order to advance to the next room. The objective of this project was to introduce the core concepts of BME to prospective students, rather than attempt to teach an entire BME curriculum. Based on user testing at various phases in the project, we concluded that the gameplay was engaging enough to keep most users' interest through the educational puzzles, and the potential for expanding this project to reach an even greater audience is vast.
ContributorsNitescu, George (Co-author) / Medawar, Alexandre (Co-author) / Spano, Mark (Thesis director) / LaBelle, Jeffrey (Committee member) / Guiang, Kristoffer (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2014-05
Description
This thesis presents a kit of materials intended to present students with a glimpse of what engineering entails by guiding them through building engineering projects similar to what is in the real world. The objective of this project is to pique the interest of children by introducing them to lesser known engineering related topics, and increasing their literacy of terms and methods engineers use to solve problems. The effectiveness of the kit’s content and teaching methods was tested in a classroom of 6th graders and was measured using the responses from surveys handed out. I found that kit did in fact positively lead to a change in the way the students perceived engineering, and it taught students about new engineering related topics. Students were capable of completing difficult tasks of wiring and coding successfully through the use of detailed instruction. However, the instructions were seen in two opposing views of either being too overwhelming or more guidance was necessary.
ContributorsQuezada, Hebellyn Arleth (Author) / Aukes, Daniel (Thesis director) / Kellam, Nadia (Committee member) / Engineering Programs (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
The relationship between video games and education is something that has been studied extensively in academia. Based upon these studies a new concept was created, gamification. Gamification is the next step in video game research to analyze why video games enhance learning. The interest and research into this concept have developed so much so that it has become its own topic area for research. This study is looking to analyze the effect that gamification has on not only learning, but also self-efficacy. Through a choose your own adventure game, the knowledge and self-efficacy of participants will be examined to observe the differences when learning difficult engineering concepts with and without gamification. It is expected that participants that experienced training through gamification will demonstrate deeper learning and higher self-efficacy than trained through a video. Furthermore, it is anticipated that some video trained participants’ self-efficacy will increase; however, their comprehension will be less than participants trained through gamification. The results of this study can help promote the interest in researching gamification and education, while influencing educators to corporate gamification elements when designing their courses. Moreover, this study continued through adaptation and integration into a statics forces class, investigated if the same results can be found within a classroom setting.
ContributorsKanechika, Amber (Author) / Craig, Scotty (Thesis director) / Roscoe, Rod (Committee member) / Engineering Programs (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
The purpose of this study is to spark a discussion for engineers and their firms to consider the impact of border barriers on wildlife. The focus of this study is to consider if or how engineers make those considerations, such as through design modifications. Barriers block wildlife migration patterns, disabling them from life-sustaining resources. This is particularly important due to an increasing trend in habitat loss, urban development, and climate change. During literature analysis of border barrier impacts, and outreaching to relevant organizations and individuals, there was little to no public documentation or discussion from the engineering community found. Discussion that was found is included in this study, but the lack of connection between conservation and engineering professionals is eminently profound. Therefore, the analysis of studying engineering design considerations additionally studied the relationship between environmental and engineering professionals. Types of research included involves literature analysis of journal articles, reports, project plans for construction, and environmental laws pertinent to wildlife impact.
ContributorsMcMillin, Kaci (Author) / Karwat, Darshan (Thesis director) / Senko, Jesse (Committee member) / Engineering Programs (Contributor) / Environmental and Resource Management (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
This creative project is a children’s book designed to teach young readers about engineering through a fictional story about a group of children creating a robot for their school’s show-and-tell. The story aims to teach engineering principles to children in a lighthearted and entertaining form, narrating notions such as the design process, prototyping, specialty fields, and repurposing. Other principles such as learning patience, compromise and teamwork are also conveyed throughout the plot details. Small life lessons that transcend the realm of engineering are also embodied throughout. The plot of the story is a young girl who goes to visit her grandfather who is a garage tinkerer with a love of spare parts. He tells her about his job as a robotics engineer, and she loves it. She goes and tells her friends who decide they want to make a robot for show-and-tell at school. The grandfather agrees to help them build a robot and thus the group of kids are walked through the engineering design process, learning new things (and specialization) along the way. The story ends by revealing that the whole story was a flashback the main character was having as she is about to start her first day at an engineering firm.
ContributorsReed, Shelby Marie (Author) / Oberle, Eric (Thesis director) / Williams, Wendy (Committee member) / Engineering Programs (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
With the ongoing development of simulation technology, classic barriers to social interactions are beginning to be dismantled. One such exchange is encapsulated within education—instructors can use simulations to make difficult topics more manageable and accessible to students. Within simulations that include virtual humans, however, there are important factors to consider. Participants playing in virtual environments will act in a way that is consistent with their real-world behaviors—including their implicit biases. The current study seeks to determine the impact of virtual humans’ skin tone on participants’ behaviors when applying engineering concepts to simulated projects. Within a comparable study focused on a medical training simulation, significantly more errors and delays were made when working for the benefit of dark-skinned patients in a virtual context. In the current study, participants were given a choose-your-own-adventure style game in which they constructed simulated bridges for either a light- ordark-skinned community, and the number of errors and time taken for each decision was tracked. Results are expected to be consistent with previous study, indicating a higher number of errors and less time taken for each decision, although these results may be attenuated by a
lack of time pressure and urgency to the given situations. If these expected results hold, there may be implications for both undergraduate engineering curriculum and real-world engineering endeavors.
lack of time pressure and urgency to the given situations. If these expected results hold, there may be implications for both undergraduate engineering curriculum and real-world engineering endeavors.
ContributorsEldemire, Kate (Author) / Craig, Scotty D. (Thesis director) / Roscoe, Rod D. (Committee member) / Engineering Programs (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05