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Description
Pb-free solders are used as interconnects in various levels of micro-electronic packaging. Reliability of these interconnects is very critical for the performance of the package. One of the main factors affecting the reliability of solder joints is the presence of porosity which is introduced during processing of the joints. In

Pb-free solders are used as interconnects in various levels of micro-electronic packaging. Reliability of these interconnects is very critical for the performance of the package. One of the main factors affecting the reliability of solder joints is the presence of porosity which is introduced during processing of the joints. In this thesis, the effect of such porosity on the deformation behavior and eventual failure of the joints is studied using Finite Element (FE) modeling technique. A 3D model obtained by reconstruction of x-ray tomographic image data is used as input for FE analysis to simulate shear deformation and eventual failure of the joint using ductile damage model. The modeling was done in ABAQUS (v 6.10). The FE model predictions are validated with experimental results by comparing the deformation of the pores and the crack path as predicted by the model with the experimentally observed deformation and failure pattern. To understand the influence of size, shape, and distribution of pores on the mechanical behavior of the joint four different solder joints with varying degrees of porosity are modeled using the validated FE model. The validation technique mentioned above enables comparison of the simulated and actual deformation only. A more robust way of validating the FE model would be to compare the strain distribution in the joint as predicted by the model and as observed experimentally. In this study, to enable visualization of the experimental strain for the 3D microstructure obtained from tomography, a three dimensional digital image correlation (3D DIC) code has been implemented in MATLAB (MathWorks Inc). This developed 3D DIC code can be used as another tool to verify the numerical model predictions. The capability of the developed code in measuring local displacement and strain is demonstrated by considering a test case.
ContributorsJakkali, Vaidehi (Author) / Chawla, Nikhilesh K (Thesis advisor) / Jiang, Hanqing (Committee member) / Solanki, Kiran (Committee member) / Arizona State University (Publisher)
Created2011
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Description

This thesis research aims to define, identify, and promote community theatre as a “third space” for disadvantaged youth. A third space is defined by the Oxford dictionary as “...the in-between, or hybrid, spaces, where the first and second spaces work together to generate a new third space. First and second

This thesis research aims to define, identify, and promote community theatre as a “third space” for disadvantaged youth. A third space is defined by the Oxford dictionary as “...the in-between, or hybrid, spaces, where the first and second spaces work together to generate a new third space. First and second spaces are two different, and possibly conflicting, spatial groupings where people interact physically and socially: such as home (everyday knowledge) and school (academic knowledge)” (Oxford Dictionary, 2021). For disadvantaged youth, the creation of a third space in the theatre can give them a safe environment away from issues they may have at home or at school, it can further their learning about themselves and others, and it can also help those youth feel a sense of belonging to a community larger than themselves. Because of these benefits, it is clear that performing arts programs can offer a great impact on disadvantaged youth; however, many theatre companies struggle to market their programming to said communities. This may be in part, due to low marketing budgets, no specificity in labor resources dedicated to youth programming, or ineffective marketing strategies and tactics. This research aims to provide tangible recommendations for youth programmers to better involve their target audience.

ContributorsFeuerstein, Kaleigh Nicole (Co-author) / Narducci, Emily (Co-author) / Gray, Nancy (Thesis director) / Woodson, Stephani (Committee member) / Dean, W.P. Carey School of Business (Contributor) / Department of Marketing (Contributor) / Department of Management and Entrepreneurship (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

Music has consistently been documented as a manner to bring people together across cultures throughout the world. In this research, we propose that people use similar musical taste as a strong sign of potential social connection. To investigate this notion, we draw on literature examining how music merges the public/private

Music has consistently been documented as a manner to bring people together across cultures throughout the world. In this research, we propose that people use similar musical taste as a strong sign of potential social connection. To investigate this notion, we draw on literature examining how music merges the public/private self, the link to personality, and group identity, as well as how it is linked to romantic relationships. Thus, music can be a tool when wanting to get to know someone else and/or forge a platonic relationship. To test this hypothesis, we designed an experiment comparing music relative to another commonality (sharing a sports team in common) to see which factor is stronger in triggering an online social connection. We argue that people believe they have more in common with someone who shares similar music taste compared to other commonalities. We discuss implications for marketers on music streaming platforms.

ContributorsDrambarean, Julianna Rose (Co-author) / Simmons, Logan (Co-author) / Samper, Adriana (Thesis director) / Martin, Nathan (Committee member) / Department of Marketing (Contributor) / Watts College of Public Service & Community Solut (Contributor) / Dean, W.P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description
Production from a high pressure gas well at a high production-rate encounters the risk of operating near the choking condition for a compressible flow in porous media. The unbounded gas pressure gradient near the point of choking, which is located near the wellbore, generates an effective tensile stress on the

Production from a high pressure gas well at a high production-rate encounters the risk of operating near the choking condition for a compressible flow in porous media. The unbounded gas pressure gradient near the point of choking, which is located near the wellbore, generates an effective tensile stress on the porous rock frame. This tensile stress almost always exceeds the tensile strength of the rock and it causes a tensile failure of the rock, leading to wellbore instability. In a porous rock, not all pores are choked at the same flow rate, and when just one pore is choked, the flow through the entire porous medium should be considered choked as the gas pressure gradient at the point of choking becomes singular. This thesis investigates the choking condition for compressible gas flow in a single microscopic pore. Quasi-one-dimensional analysis and axisymmetric numerical simulations of compressible gas flow in a pore scale varicose tube with a number of bumps are carried out, and the local Mach number and pressure along the tube are computed for the flow near choking condition. The effects of tube length, inlet-to-outlet pressure ratio, the number of bumps and the amplitude of the bumps on the choking condition are obtained. These critical values provide guidance for avoiding the choking condition in practice.
ContributorsYuan, Jing (Author) / Chen, Kangping (Thesis advisor) / Wang, Liping (Committee member) / Huang, Huei-Ping (Committee member) / Arizona State University (Publisher)
Created2013
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Description
Tesla turbo-machinery offers a robust, easily manufactured, extremely versatile prime mover with inherent capabilities making it perhaps the best, if not the only, solution for certain niche applications. The goal of this thesis is not to optimize the performance of the Tesla turbine, but to compare its performance with various

Tesla turbo-machinery offers a robust, easily manufactured, extremely versatile prime mover with inherent capabilities making it perhaps the best, if not the only, solution for certain niche applications. The goal of this thesis is not to optimize the performance of the Tesla turbine, but to compare its performance with various working fluids. Theoretical and experimental analyses of a turbine-generator assembly utilizing compressed air, saturated steam and water as the working fluids were performed and are presented in this work. A brief background and explanation of the technology is provided along with potential applications. A theoretical thermodynamic analysis is outlined, resulting in turbine and rotor efficiencies, power outputs and Reynolds numbers calculated for the turbine for various combinations of working fluids and inlet nozzles. The results indicate the turbine is capable of achieving a turbine efficiency of 31.17 ± 3.61% and an estimated rotor efficiency 95 ± 9.32%. These efficiencies are promising considering the numerous losses still present in the current design. Calculation of the Reynolds number provided some capability to determine the flow behavior and how that behavior impacts the performance and efficiency of the Tesla turbine. It was determined that turbulence in the flow is essential to achieving high power outputs and high efficiency. Although the efficiency, after peaking, begins to slightly taper off as the flow becomes increasingly turbulent, the power output maintains a steady linear increase.
ContributorsPeshlakai, Aaron (Author) / Phelan, Patrick (Thesis advisor) / Trimble, Steve (Committee member) / Wang, Liping (Committee member) / Arizona State University (Publisher)
Created2012
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Description
Recently, the use of zinc oxide (ZnO) nanowires as an interphase in composite materials has been demonstrated to increase the interfacial shear strength between carbon fiber and an epoxy matrix. In this research work, the strong adhesion between ZnO and carbon fiber is investigated to elucidate the interactions at the

Recently, the use of zinc oxide (ZnO) nanowires as an interphase in composite materials has been demonstrated to increase the interfacial shear strength between carbon fiber and an epoxy matrix. In this research work, the strong adhesion between ZnO and carbon fiber is investigated to elucidate the interactions at the interface that result in high interfacial strength. First, molecular dynamics (MD) simulations are performed to calculate the adhesive energy between bare carbon and ZnO. Since the carbon fiber surface has oxygen functional groups, these were modeled and MD simulations showed the preference of ketones to strongly interact with ZnO, however, this was not observed in the case of hydroxyls and carboxylic acid. It was also found that the ketone molecules ability to change orientation facilitated the interactions with the ZnO surface. Experimentally, the atomic force microscope (AFM) was used to measure the adhesive energy between ZnO and carbon through a liftoff test by employing highly oriented pyrolytic graphite (HOPG) substrate and a ZnO covered AFM tip. Oxygen functionalization of the HOPG surface shows the increase of adhesive energy. Additionally, the surface of ZnO was modified to hold a negative charge, which demonstrated an increase in the adhesive energy. This increase in adhesion resulted from increased induction forces given the relatively high polarizability of HOPG and the preservation of the charge on ZnO surface. It was found that the additional negative charge can be preserved on the ZnO surface because there is an energy barrier since carbon and ZnO form a Schottky contact. Other materials with the same ionic properties of ZnO but with higher polarizability also demonstrated good adhesion to carbon. This result substantiates that their induced interaction can be facilitated not only by the polarizability of carbon but by any of the materials at the interface. The versatility to modify the magnitude of the induced interaction between carbon and an ionic material provides a new route to create interfaces with controlled interfacial strength.
ContributorsGalan Vera, Magdian Ulises (Author) / Sodano, Henry A (Thesis advisor) / Jiang, Hanqing (Committee member) / Solanki, Kiran (Committee member) / Oswald, Jay (Committee member) / Speyer, Gil (Committee member) / Arizona State University (Publisher)
Created2013
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Description
With increasing concerns of the intrinsic toxicity of lead (Pb) in electronics, a series of tin (Sn) based alloys involving silver (Ag) and copper (Cu) have been proposed as replacements for Pb-Sn solder and widely accepted by industry. However, they have a higher melting point and often exhibit poorer damage

With increasing concerns of the intrinsic toxicity of lead (Pb) in electronics, a series of tin (Sn) based alloys involving silver (Ag) and copper (Cu) have been proposed as replacements for Pb-Sn solder and widely accepted by industry. However, they have a higher melting point and often exhibit poorer damage tolerance than Pb-Sn alloys. Recently, a new class of alloys with trace amount of rare-earth (RE) elements has been discovered and investigated. In previous work from Prof. Chawla's group, it has been shown that cerium (Ce)-based Pb-free solder are less prone to oxidation and Sn whiskering, and exhibit desirable attributes of microstructural refinement and enhanced ductility relative to lanthanum (La)-based Sn-3.9Ag-0.7Cu (SAC) alloy. Although the formation of RESn3 was believed to be directly responsible for the enhanced ductility in RE-containing SAC solder by allowing microscopic voids to nucleate throughout the solder volume, this cavitation-based mechanism needs to be validated experimentally and numerically. Additionally, since the previous study has exhibited the realistic feasibility of Ce-based SAC lead-free solder alloy as a replacement to conventional SAC alloys, in this study, the proposed objective focuses on the in in-depth understanding of mechanism of enhanced ductility in Ce-based SAC alloy and possible issues associated with integration of this new class of solder into electronic industry, including: (a) study of long-term thermal and mechanical stability on industrial metallization, (b) examine the role of solder volume and wetting behavior of the new solder, relative to Sn-3.9Ag-0.7Cu alloys, (c) conduct experiments of new solder alloys in the form of mechanical shock and electromigration. The research of this new class alloys will be conducted in industrially relevant conditions, and the results would serve as the first step toward integration of these new, next generation solders into the industry.
ContributorsXie, Huxiao (Author) / Chawla, Nikhilesh (Thesis advisor) / Krause, Stephen (Committee member) / Solanki, Kiran (Committee member) / Mirpuri, Kabir (Committee member) / Arizona State University (Publisher)
Created2012
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Description
The following is a report that will evaluate the microstructure of the nickel-based superalloy Hastelloy X and its relationship to mechanical properties in different load conditions. Hastelloy X is of interest to the company AORA because its strength and oxidation resistance at high temperatures is directly applicable to their needs

The following is a report that will evaluate the microstructure of the nickel-based superalloy Hastelloy X and its relationship to mechanical properties in different load conditions. Hastelloy X is of interest to the company AORA because its strength and oxidation resistance at high temperatures is directly applicable to their needs in a hybrid concentrated solar module. The literature review shows that the microstructure will produce different carbides at various temperatures, which can be beneficial to the strength of the alloy. These precipitates are found along the grain boundaries and act as pins that limit dislocation flow, as well as grain boundary sliding, and improve the rupture strength of the material. Over time, harmful precipitates form which counteract the strengthening effect of the carbides and reduce rupture strength, leading to failure. A combination of indentation and microstructure mapping was used in an effort to link local mechanical behavior to microstructure variability. Electron backscatter diffraction (EBSD) and energy dispersive spectroscopy (EDS) were initially used as a means to characterize the microstructure prior to testing. Then, a series of room temperature Vickers hardness tests at 50 and 500 gram-force were used to evaluate the variation in the local response as a function of indentation size. The room temperature study concluded that both the hardness and standard deviation increased at lower loads, which is consistent with the grain size distribution seen in the microstructure scan. The material was then subjected to high temperature spherical indentation. Load-displacement curves were essential in evaluating the decrease in strength of the material with increasing temperature. Through linear regression of the unloading portion of the curve, the plastic deformation was determined and compared at different temperatures as a qualitative method to evaluate local strength.
ContributorsCelaya, Andrew Jose (Author) / Peralta, Pedro (Thesis director) / Solanki, Kiran (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2015-05
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Description

What if I told you that a few photos of a sweatshirt, delivered at the perfect time, cracked a case that had stumped some of the world’s greatest marketing minds for more than twenty years? What if I told you that a dismissed lawsuit played an integral part in this?

What if I told you that a few photos of a sweatshirt, delivered at the perfect time, cracked a case that had stumped some of the world’s greatest marketing minds for more than twenty years? What if I told you that a dismissed lawsuit played an integral part in this? One made possible by a rainy night in Couva, Trinidad? Or that all of this, hundreds of years in the making, could aid a wrongfully incarcerated man in being freed after spending twenty two years in prison, and pioneer one of the largest-scale social justice movements of the 21st century? All catalyzed by the effects of a global pandemic? If I told you, would you believe me? But let’s get back to that sweatshirt for now.<br/>In January 2020, the Coronavirus was a seemingly distant issue for another part of the world to most Americans. A generation that had seen the likes of H1N1 and Ebola come, cause irrational panic, and subsequently disappear had grown complacent with regard to unknown diseases. On March 9th, Utah Jazz center Rudy Gobert took a defiant step in dispelling fears of COVID-19 by touching every microphone in the room at the end of an interview. Two days later, a test revealed that he had contracted the virus, the first professional athlete to do so. The NBA suspended all activities, and thus began the succession of sports leagues across the nation suspending their seasons as global infection numbers rose. But we humans are resilient. As weeks became months, the NBA and WNBA were able to engineer “bubbles” to play in: isolated areas with only the players and essential personnel to play the games, equipped with safety precautions and persistent testing. With no fans allowed inside, social media and media members provided the only glimpse into the “bubble” that ordairy fans would get.<br/>The mornings of July 25th and 26th, as the players arrived for the first games of the day and were snapped by photographers, many sported orange hoodies with the trademark white WNBA logo in the center, to promote the start of the WNBA’s “bubble” season that summer. This sent the internet into a frenzy. “#OrangeHoodie” was trending across all social media platforms, the item sold out on many websites, and more people than ever were talking about the WNBA online. That season, WNBA viewership spiked. More people watched the WNBA than ever before, even with the NBA’s playoffs taking place at the same time. How, then, did a single orange hoodie change the future of marketing the WNBA? What does that tell us about other women’s sports that have similarly struggled with attention and viewership? What role does media exposure play in all of this; do we perceive women differently in the media than we do men? Are these issues rooted in deeper societal prejudices, or are women’s sports simply quantifiably less entertaining?<br/>On a journey to find the answers to these questions, I learned a lot about the relationship of media and culture, about sport, and about the outstanding untold stories of American sportswomen. However, the most important thing I found was that women are marketable. After long being denied the opportunities and exposure they deserve, American culture has as a result pushed women to the background under the guise of them not being demanded or marketable. This could not be further from the truth. They are not demanded because they are not seen. Investing in sportswomen would not only create a better future for all women, but for all people. How, then, is this achievable? How will the powers that be allow for changes to be made? How can we as individuals be receptive to this change? In this thesis, I will take you on a journey where media is fun and fair, and where the future is female.

ContributorsLandrau, Roberto Luis (Author) / Eaton, John (Thesis director) / Wong, Kelvin (Committee member) / Dean, W.P. Carey School of Business (Contributor) / Department of Marketing (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description

Make-A-Wish America has a world-renowned reputation as one of the best nonprofits in the world, and is widely known amongst many individuals looking to support or donate to nonprofits. Their work is not only a fundamental part of human services care within the nonprofit world, but their unique online platform

Make-A-Wish America has a world-renowned reputation as one of the best nonprofits in the world, and is widely known amongst many individuals looking to support or donate to nonprofits. Their work is not only a fundamental part of human services care within the nonprofit world, but their unique online platform and social media presence is a differentiating factor among many other nonprofits and for-profit businesses alike. The purpose of this study is to research Make-A-Wish America’s brand management and marketing strategies as a nonprofit, including secondary research on the brand itself, analyze all environmental factors that affect its marketing strategy, assess their market segmentation, targeting, and positioning, and evaluate their integrated marketing communications strategy. Additionally, I conducted interviews with Make-A-Wish America professionals working within the brand management department at the national office. The individuals were interviewed with various marketing backgrounds within the brand department to gain a deeper insight into their individual experiences and assessments of Make-A-Wish America’s brand management and marketing strategy. My specific thesis goals include utilizing my marketing recommendations to grow Make-A-Wish America’s profits, specifically in actions to increase fundraising. Also, my thesis goal is to find recommendations to outperform competition in gaining supporters and donors as well as, more recently, analyzing the effects of the COVID-19 pandemic and making recommendations on how they can grow despite this economic tragedy. The results suggest that there are common themes amongst my secondary research and primary research, resulting in marketing recommendations that Make-A-Wish America can utilize to better market to donors and supporters in the future, giving them competitive advantage over other nonprofits and combatting the effects of COVID-19. Recommendations for Make-A-Wish America include investing in their own research and development in terms of customer relationship management tools, online fundraising campaigns, and technology to better inform donors of their mission, vision, and values, diversifying their donor profile and targeted communities, and taking advantage of their point of parity within their social media online platform.

ContributorsBarton, Maddy Taylor (Author) / Montoya, Detra (Thesis director) / Ostrom, Lonnie (Committee member) / Department of Economics (Contributor) / Department of Marketing (Contributor) / School of Community Resources and Development (Contributor) / Dean, W.P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05