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- Creators: Haydn, Joseph, 1732-1809
Description
Although wind turbine bearings are designed to operate 18-20 years, in the recent years premature failure among these bearings has caused this life to reduce to as low as a few months to a year. One of the leading causes of premature failure called white structure flaking is a mechanism that was first cited in literature decades ago but not much is understood about it even today. The cause of this mode of failure results from the initiation of white etched cracks (WECs). In this report, different failure mechanisms, especially premature failure mechanisms that were tested and analyzed are demonstrated as a pathway to understanding this phenomenon. Through the use of various tribometers, samples were tested in diverse and extreme conditions in order to study the effect of these different operational conditions on the specimen. Analysis of the tested samples allowed for a comparison of the microstructure alterations in the tested samples to the field bearings affected by WSF.
ContributorsSharma, Aman (Author) / Foy, Joseph (Thesis director) / Adams, James (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2015-05
Description
Analysis of 4 lesson plans for primary education in which 3D printers are used either to build components or are directly used by students. Provides critique on how proper investment and utilization of this new technology can enrich education and misuse can waste time, money, and even reduce the quality of education.
ContributorsPrzeslica, Michael Cody (Author) / Adams, James (Thesis director) / Krause, Stephen (Committee member) / Barrett, The Honors College (Contributor) / Materials Science and Engineering Program (Contributor)
Created2014-05
Description
The transition to lead-free solder in the electronics industry has benefitted the environment in many ways. However, with new materials systems comes new materials issues. During the processing of copper pads, a protective surface treatment is needed to prevent the copper from oxidizing. Characterizing the copper oxidation underneath the surface treatment is challenging but necessary for product reliability and failure analysis. Currently, FIB-SEM, which is time-consuming and expensive, is what is used to understand and analyze the surface treatment-copper oxide(s)-copper system. This project's goals were to determine a characterization methodology that cuts both characterization time and cost in half for characterizing copper oxidation beneath a surface treatment and to determine which protective surface treatment is the best as defined by multiple criterion such as cost, sustainability, and reliability. Two protective surface treatments, organic solderability preservative (OSP) and chromium zincate, were investigated, and multiple characterization techniques were researched. Six techniques were tested, and three were deemed promising. Through our studies, it was determined that the best surface treatment was organic solderability preservative (OSP) and the ideal characterization methodology would be using FIB-SEM to calibrate a QCM model, along with using SERA to confirm the QCM model results. The methodology we propose would result in a 91% reduction in characterization cost and a 92% reduction in characterization time. Future work includes further calibration of the QCM model using more FIB/SEM data points and eventually creating a model for oxide layer thickness as a function of exposure time and processing temperature using QCM as the primary data source. In doing my Capstone project for Intel, a large electronics manufacturing company, I feel it is important to remember the effects of our tools and industry on the environment and to consider the product life cycle in terms other than monetary gain and raw material recycling. To this end I will be discussing how lead is and was used in manufacturing, how it is disposed of, and how this effects the environment including plant, animal, and insect life, as well as ground water contamination. Since the ban was enacted several years ago, I will compare how lead-free alternatives currently in use compare in environmental impact and possibly raise the question of whether we have simply traded one evil for another.
ContributorsBranch Kelly, Marion Zoe (Author) / Adams, James (Thesis director) / Krause, Stephen (Committee member) / Barrett, The Honors College (Contributor) / Materials Science and Engineering Program (Contributor)
Created2015-05
Description
The financial feasibility of NextPotential's X-doped photocatalyst is uncertain, the outcome depends on how much the material cost becomes reduced due to mass production techniques. If carbon taxes continue on the current trend the photocatalyst is highly likely to become financially feasible. Without carbon taxes, it is still likely the photocatalyst will achieve economical feasibility. The land area required by the photocatalyst is a feasible size. The minimal environmental downsides are that more land will be used and water will be used, but both of these are minimal compared to the benefit of eliminating carbon emissions.
ContributorsMcmullan, Kyle Jonathan (Co-author) / Lahpai, Mun (Co-author) / Donnelly, Connor (Co-author) / Puzhaev, Boris (Co-author) / Adams, James (Thesis director) / Krause, Stephen (Committee member) / Barrett, The Honors College (Contributor) / Materials Science and Engineering Program (Contributor)
Created2015-05
Description
The transition to lead-free solder in the electronics industry has benefited the environment in many ways. However, with new materials systems comes new materials issues. During the processing of copper pads, a protective surface treatment is needed to prevent the copper from oxidizing. Characterizing the copper oxidation underneath the surface treatment is challenging but necessary for product reliability and failure analysis. Currently, FIB-SEM, which is time-consuming and expensive, is what is used to understand and analyze the surface treatment-copper oxide(s)-copper system. This project's goals were to determine a characterization methodology that cuts both characterization time and cost in half for characterizing copper oxidation beneath a surface treatment and to determine which protective surface treatment is the best as defined by multiple criterion such as cost, sustainability, and reliability. Two protective surface treatments, organic solderability preservative (OSP) and chromium zincate, were investigated, and multiple characterization techniques were researched. Six techniques were tested, and three were deemed promising. Through our studies, it was determined that the best surface treatment was organic solderability preservative (OSP) and the ideal characterization methodology would be using FIB-SEM to calibrate a QCM model, along with using SERA to confirm the QCM model results. The methodology we propose would result in a 91% reduction in characterization cost and a 92% reduction in characterization time. Future work includes further calibration of the QCM model using more FIB/SEM data points and eventually creating a model for oxide layer thickness as a function of exposure time and processing temperature using QCM as the primary data source. An additional short essay on the role of SEM on the continuing miniaturization of integrated circuits is included at the end. This paper explores the intertwined histories of the scanning electron microscope and the integrated circuit, highlighting how advances in SEM influence integrated circuit advances.
ContributorsSmith, Bethany Blair (Co-author) / Marion, Branch Kelly (Co-author) / Cruz, Hernandez (Co-author) / Kimberly, McGuiness (Co-author) / Adams, James (Thesis director) / Krause, Stephen (Committee member) / Barrett, The Honors College (Contributor) / Materials Science and Engineering Program (Contributor)
Created2015-05
Description
The unemployment rate for adults with Autism Spectrum Disorders (ASDs) sits between 88 and 95 percent. With the prevalence of ASDs growing by the year, the transition into adulthood is a problem this country will increasingly face. To shed light on this issue and spread awareness, the method was to create a documentary 26 minutes in length about the transition adults with ASDs face after graduating high school. The result was "Breaking the Spectrum," which includes testimony from adults with ASDs who have jobs, attend skills programs or go to college, experts in the field and founders of organizations who seek to decrease the unemployment rate.
ContributorsLancial, Alexandra Marie (Author) / Craft, John (Thesis director) / Adams, James (Committee member) / Dodge, Nancie (Committee member) / Barrett, The Honors College (Contributor) / Walter Cronkite School of Journalism and Mass Communication (Contributor)
Created2014-05
Description
The work for this thesis was done in conjunction to that of my capstone project, which focused on understanding the effects of powder re-use on products built via Direct Metal Laser Sintering (DMLS), a specific additive manufacturing (AM) technique where powder particles are sintered together to form final parts. Honeywell Aerospace helped support this research by providing materials and mentorship; this work will play a key role in their decision to implement DMLS and other AM methods on a larger scale. Whereas the capstone focuses on the technical details of constructing characterization equipment, analyzing data, and formulating a concluding recommendation on whether the powder can be re-used, the thesis attempts to put this body of work in its greater context, surveying the economic and environmental effects of additive manufacturing technologies with a slant towards the aerospace industry. Shifts in the supply chain with aircraft parts and how this affects costs are explored, as well as how the quality and reliability of additively manufactured parts differs from their traditionally manufactured counterparts and the effects of this on related industries and purchasers.
ContributorsMurella, Anoosha Sainagaki (Author) / Adams, James (Thesis director) / Tasooji, Amaneh (Committee member) / Materials Science and Engineering Program (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
In injection molded plastic parts, knit lines occur where opposing streams of material fuse together while the mold cavity fills. When parts with knit lines experience external loading, the knit lines cause areas of mechanical weakness. This weakness is especially drastic in fiber-reinforced polymers due to an unfavorable orientation of fibers at the knit line. A possible way to reduce the impact of knit lines is to incorporate overflow tabs into the mold design. An overflow tab is a chamber attached to the mold cavity that provides an extra space for the end of material flow to occur. Research shows that overflow tabs improve the fiber orientation at the knit line, resulting in increased mechanical strength. The goal of this study is to utilize overflow tabs to optimize the knit line strength of nylon 6-6 that is 30% carbon fiber reinforced. In this project, an initial overflow tab is first designed. Then four modifications are made to the tab design, each altering a separate variable while holding the others constant. The design changes explored for the tab in this project include adding radii to the inlet, shifting the inlet location, increasing the inlet cross-sectional area by 50%, and increasing the tab chamber volume by 50%. Specimens were molded using the initial tab design and the modified tab designs. Testing for this experiment consists of three specimens of each type for three-point bending tests, and five specimens of each type for tensile tests. The material properties analyzed are the flexural modulus, flexural strength, tensile modulus, and tensile strength. From the testing, the tab with the 50% increased volume consistently yielded the highest results and showed large improvement from the initial tab design. However, the other three tab modifications either showed negative change or slight improvement from the initial tab design. Based on the results of this study, the overflow tab volume is the most beneficial design parameter to adjust.
ContributorsJones, Justin Michael (Author) / Adams, James (Thesis director) / Wamsley, Steven (Committee member) / Computer Science and Engineering Program (Contributor) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
Graphene has the ability to advance many common fields, including: membranes, composites and coatings, energy, and electronics. For membranes, graphene will be used as a filter for desalination plants which will reduce the cost of desalination and greatly increase water security in developing countries. For composites and coatings, graphene's strength, flexibility, and lightweight will be instrumental in producing the next generation of athletic wear and sports equipment. Graphene's use in energy comes from its theorized ability to charge a phone battery in seconds or an electric car in minutes. Finally, for electronics, graphene will be used to create faster transistors, flexible electronics, and fully integrated wearable technology.
ContributorsSiegel, Adam (Author) / Adams, James (Thesis director) / Krause, Stephen (Committee member) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
This is a two-part thesis, completed in conjunction with my Materials Science and Engineering Capstone Project. The first part involves the design and testing of cold-extruded high-density polyethylene for student oboe reeds. The goal of this section was to create a longer-lasting reed that produces a similar sound to a cane reed, has less variation in quality, and costs less per year than cane reeds. For low-income students in particular, the cost of purchasing cane oboe reeds ($500-$2,000 per year) is simply not feasible. This project was designed to allow oboe to be a more affordable option for all students. Money should not be a factor that limits whether or a not a child is able to explore their interests. The process used to create the synthetic reed prototype involves cold-extrusion of high-density polyethylene in order to induce orientation in the polymer to replicate the uniaxial orientation of fibrous cane. After successful cold-extrusion of a high-density polyethylene (HDPE) cylinder, the sample was made into a reed by following standard reedmaking procedures. Then, the HDPE reed and a cane reed were quantitatively tested for various qualities, including flexural modulus, hardness, and free vibration frequency. The results from the design project are promising and show a successful proof of concept. The first prototype of an oriented HDPE reed demonstrates characteristics of a cane reed. The areas that need the most improvement are the flexural modulus and the stability of the higher overtones, but these areas can be improved with further development of the cold-extrusion process. The second part of this thesis is a survey and analysis focusing on the qualitative comparison of synthetic and cane oboe reeds. The study can be used in the future to refine the design of synthetic reeds, more specifically the cold-extruded high-density polyethylene student oboe reed I designed, to best replicate a cane reed. Rather than approaching this study from a purely engineering mindset, I brought in my own experience as an oboist. Therefore, the opinions of oboists who have a wide range of experience are considered in the survey. A panel of five oboists participated in the survey. They provided their opinion on various aspects of the five reeds, including vibrancy, response, stability, resistance, tone, and overall quality. Each of these metrics are rated on a scale from one to five, from unacceptable to performance quality. According to the survey, a participant's personal, hand-made cane reed is overall the most preferred option. My prototype HDPE student reed must be improved in many areas in order to rank near the other four reeds. However, its vibrancy and resistance already rival that of a Jones student reed. As this is just the first prototype, that is a significant accomplishment. With further refinement of the cold-extrusion and reedmaking method, the other areas of the HDPE reed may be improved, and the reed may eventually compete with the existing synthetic and cane reeds on the market.
ContributorsMitchell, Alexis Jacqueline (Author) / Adams, James (Thesis director) / Schuring, Martin (Committee member) / School of Music (Contributor) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05