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- All Subjects: Characterization
- All Subjects: energy
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
In microbial fuel cells (MFCs) the biocathode is developed as a potential alternative to chemical cathodic catalysts, which are deemed as expensive and unsustainable for applications. These cells utilize different types of microorganisms as catalysts to promote biodegradation of organic matter while simultaneously converting energy released in metabolic reactions into electrical energy. Most current research have focused more on the anodic microbes, including the current generating bacteria species, anodic microbial community composition, and the mechanisms of the extracellular electron transfer. Compared to the anode, research on the microbes of the biocathode of the MFCs are very limited and are heavily focused on the role of the bacteria in the system. Thus, further understand of the mechanism of the microbial community in the biocathode will create new engineering applications for sustainable energy. Previous research conducted by Strycharz-Glaven et al. presented an electrochemical analysis of a Marinobacter-dominated biocathode communitygrown on biocathodes in sediment/seawater-based MFCs. Chronoamperometry results indicated that current densities up to -0.04 A/m2 were produced for the biocathode. Cyclic voltammetry responses indicated a midpoint potential at 0.196 V ± 0.01 V. However, the reactor design for these experiments showed that no oxygen is supplied to the electrochemical system. By incorporating an air diffusion membrane to the cathode of the reactor, chronoamperometry results have produced current density in the system up to -0.15 A/m2. Cyclic voltammetry results have also displayed a midpoint potential of 0.25 V ± 0.01 V under scan rates of 0.2 mV/s. Thus, this electrochemical setup has increased the current output of the system.
ContributorsWang, Zixuan (Author) / Torres, Cesar (Thesis director) / Hart, Steven (Committee member) / Materials Science and Engineering Program (Contributor) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
There is surprisingly little scientific literature describing whether a hockey slap shot positively or negatively transfers to a driving golf swing. Golf and hockey use a similar kinematic sequence to send the ball / puck towards a target, but does that directly translate to positive skill transfer between the two sports, or are there other important factors that could result in a negative skill transfer? The aim of this study is to look further into the two kinematic sequences and determine their intertask skill transfer type. A field experiment was conducted, following a specific research design, in order to compare performance between two groups, one being familiar with the skill that may transfer (hockey slapshot) and the other group being unfamiliar. Both groups had no experience in the skill being tested (driving golf swing) and various data was collected as all of the subjects performed 10 golf swings. The results of the data analysis showed that the group with experience in hockey had a higher variability of ball distance and ball speed. There are many factors of a hockey slapshot that are likely to develop a negative intertask skill transfer, resulting in this group's high inconsistency when performing a golf swing. On the other hand, the group with hockey experience also had higher mean club speed, showing that some aspects of the hockey slapshot resulted in a positive skill transfer, aiding their ability to perform a golf swing.
ContributorsLarson, Finn Althea (Author) / Peterson, Daniel (Thesis director) / Cryer, Michael (Committee member) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
With renewable energy on the rise, researchers have turned their funding and their focus towards new solar cell technologies, and perovskites are a major source of interest. This class of materials is particularly interesting due to their quick, simple synthesis as well as their physical and electrical superiority when compared to current silicon-based solar cells. Through this thesis, we will explore the synthesis of various types of perovskites and their subsequent characterization, which includes optical microscopy, photoluminescence spectroscopy, Raman microscopy, and X-ray diffraction. Analyzing two different perovskites both before and after a two-week period of storage revealed that while synthesis is indeed experiment-friendly, these materials have a concerning lack of stability even in ideal conditions.
ContributorsBuzas, Benjamin Joseph (Author) / Tongay, Sefaattin (Thesis director) / Muhich, Christopher (Committee member) / Materials Science and Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Hyperspectral imaging is a novel technology which allows for the collection of reflectance spectra of a sample in-situ and at a distance. A rapidly developing technology, hyperspectral imaging has been of particular interest in the field of art characterization, authentication, and conservation as it avoids the pitfalls of traditional characterization techniques and allows for the rapid and wide collection of data never before possible. It is hypothesized that by combining the power of hyperspectral imaging with machine learning, a new framework for the in-situ and automated characterization and authentication of artworks can be developed. This project, using the CMYK set of inks, began the preliminary development of such a framework. It was found that hyperspectral imaging and machine learning as a combination show significant potential as an avenue for art authentication, though further progress and research is needed to match the reliability of status quo techniques.
ContributorsChowdhury, Tanzil Aziz (Author) / Newman, Nathan (Thesis director) / Tongay, Sefaattin (Committee member) / School of Politics and Global Studies (Contributor) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05