This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students. 

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With the increasing focus on developing environmentally benign electronic packages, lead-free solder alloys have received a great deal of attention. Mishandling of packages, during manufacture, assembly, or by the user may cause failure of solder joint. A fundamental understanding of the behavior of lead-free solders under mechanical shock conditions is

With the increasing focus on developing environmentally benign electronic packages, lead-free solder alloys have received a great deal of attention. Mishandling of packages, during manufacture, assembly, or by the user may cause failure of solder joint. A fundamental understanding of the behavior of lead-free solders under mechanical shock conditions is lacking. Reliable experimental and numerical analysis of lead-free solder joints in the intermediate strain rate regime need to be investigated. This dissertation mainly focuses on exploring the mechanical shock behavior of lead-free tin-rich solder alloys via multiscale modeling and numerical simulations. First, the macroscopic stress/strain behaviors of three bulk lead-free tin-rich solders were tested over a range of strain rates from 0.001/s to 30/s. Finite element analysis was conducted to determine appropriate specimen geometry that could reach a homogeneous stress/strain field and a relatively high strain rate. A novel self-consistent true stress correction method is developed to compensate the inaccuracy caused by the triaxial stress state at the post-necking stage. Then the material property of micron-scale intermetallic was examined by micro-compression test. The accuracy of this measure is systematically validated by finite element analysis, and empirical adjustments are provided. Moreover, the interfacial property of the solder/intermetallic interface is investigated, and a continuum traction-separation law of this interface is developed from an atomistic-based cohesive element method. The macroscopic stress/strain relation and microstructural properties are combined together to form a multiscale material behavior via a stochastic approach for both solder and intermetallic. As a result, solder is modeled by porous plasticity with random voids, and intermetallic is characterized as brittle material with random vulnerable region. Thereafter, the porous plasticity fracture of the solders and the brittle fracture of the intermetallics are coupled together in one finite element model. Finally, this study yields a multiscale model to understand and predict the mechanical shock behavior of lead-free tin-rich solder joints. Different fracture patterns are observed for various strain rates and/or intermetallic thicknesses. The predictions have a good agreement with the theory and experiments.
ContributorsFei, Huiyang (Author) / Jiang, Hanqing (Thesis advisor) / Chawla, Nikhilesh (Thesis advisor) / Tasooji, Amaneh (Committee member) / Mobasher, Barzin (Committee member) / Rajan, Subramaniam D. (Committee member) / Arizona State University (Publisher)
Created2011
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Description
Concrete columns constitute the fundamental supports of buildings, bridges, and various other infrastructures, and their failure could lead to the collapse of the entire structure. As such, great effort goes into improving the fire resistance of such columns. In a time sensitive fire situation, a delay in the failure of

Concrete columns constitute the fundamental supports of buildings, bridges, and various other infrastructures, and their failure could lead to the collapse of the entire structure. As such, great effort goes into improving the fire resistance of such columns. In a time sensitive fire situation, a delay in the failure of critical load bearing structures can lead to an increase in time allowed for the evacuation of occupants, recovery of property, and access to the fire. Much work has been done in improving the structural performance of concrete including reducing column sizes and providing a safer structure. As a result, high-strength (HS) concrete has been developed to fulfill the needs of such improvements. HS concrete varies from normal-strength (NS) concrete in that it has a higher stiffness, lower permeability and larger durability. This, unfortunately, has resulted in poor performance under fire. The lower permeability allows for water vapor to build up causing HS concrete to suffer from explosive spalling under rapid heating. In addition, the coefficient of thermal expansion (CTE) of HS concrete is lower than that of NS concrete. In this study, the effects of introducing a region of crumb rubber concrete into a steel-reinforced concrete column were analyzed. The inclusion of crumb rubber concrete into a column will greatly increase the thermal resistivity of the overall column, leading to a reduction in core temperature as well as the rate at which the column is heated. Different cases were analyzed while varying the positioning of the crumb-rubber region to characterize the effect of position on the improvement of fire resistance. Computer simulated finite element analysis was used to calculate the temperature and strain distribution with time across the column's cross-sectional area with specific interest in the steel - concrete region. Of the several cases which were investigated, it was found that the improvement of time before failure ranged between 32 to 45 minutes.
ContributorsZiadeh, Bassam Mohammed (Author) / Phelan, Patrick (Thesis advisor) / Kaloush, Kamil (Thesis advisor) / Jiang, Hanqing (Committee member) / Arizona State University (Publisher)
Created2011
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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

From exploring coffee plantations with an old Irishman in the mountains of Colombia to watching the sun set over the Strait of Gibraltar from the terrace of an ancient Moroccan cafe, this thesis sent Charles and Zane on an elaborate cafe-crawl across ten countries, with stops at a few of

From exploring coffee plantations with an old Irishman in the mountains of Colombia to watching the sun set over the Strait of Gibraltar from the terrace of an ancient Moroccan cafe, this thesis sent Charles and Zane on an elaborate cafe-crawl across ten countries, with stops at a few of the world’s most interesting coffee houses. Some of these cafes, such as the world-renowned Caffé Florian (opened in 1720) and Caffé Greco (1760), are built on long-standing traditions. Others are led by innovators championing high-quality boutique shops, challenging mass production chains such as Starbucks and Tim Hortons. These newer cafes fuel a movement classified as the “Third Wave”. With a foundation gained from specialized courses with Patrick O’Malley, North America’s leading voice in coffee, Zane and Charles conducted first-hand research into the unique coffee preferences of multiple cultures, the emergence and impact of the Third Wave in these countries, and what the future may hold for coffee lovers.

ContributorsFerguson, Charles William (Co-author) / Jarecke, Zane (Co-author) / Eaton, John (Thesis director) / Bonfiglio, Thomas (Committee member) / Dean, W.P. Carey School of Business (Contributor, Contributor) / Department of Marketing (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

From exploring coffee plantations with an old Irishman in the mountains of Colombia to watching the sun set over the Strait of Gibraltar from the terrace of an ancient Moroccan cafe, this thesis sent Charles and Zane on an elaborate cafe-crawl across ten countries, with stops at a few of

From exploring coffee plantations with an old Irishman in the mountains of Colombia to watching the sun set over the Strait of Gibraltar from the terrace of an ancient Moroccan cafe, this thesis sent Charles and Zane on an elaborate cafe-crawl across ten countries, with stops at a few of the world’s most interesting coffee houses. Some of these cafes, such as the world-renowned Caffé Florian (opened in 1720) and Caffé Greco (1760), are built on long-standing traditions. Others are led by innovators championing high-quality boutique shops, challenging mass production chains such as Starbucks and Tim Hortons. These newer cafes fuel a movement classified as the “Third Wave”. With a foundation gained from specialized courses with Patrick O’Malley, North America’s leading voice in coffee, Zane and Charles conducted first-hand research into the unique coffee preferences of multiple cultures, the emergence and impact of the Third Wave in these countries, and what the future may hold for coffee lovers.

ContributorsJarecke, Zane Micheal (Co-author) / Ferguson, Charles (Co-author) / Eaton, John (Thesis director) / Bonfiglio, Thomas (Committee member) / Dean, W.P. Carey School of Business (Contributor) / Department of Management and Entrepreneurship (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description

In the early years of the National Football League, scouting and roster development resembled the wild west. Drafts were held in hotel ballrooms the day after the last game of regular season college football was played. There was no combine, limited scouting, and no salary cap. Over time, these aspects

In the early years of the National Football League, scouting and roster development resembled the wild west. Drafts were held in hotel ballrooms the day after the last game of regular season college football was played. There was no combine, limited scouting, and no salary cap. Over time, these aspects have changed dramatically, in part due to key figures from Pete Rozelle to Gil Brandt to Bill Belichick. The development and learning from this time period have laid the foundational infrastructure that modern roster construction is based upon. In this modern day, managing a team and putting together a roster involves numerous people, intense scouting, layers of technology, and, critically, the management of the salary cap. Since it was first put into place in 1994, managing the cap has become an essential element of building and sustaining a successful team. The New England Patriots’ mastery of the cap is a large part of what enabled their dynastic run over the past twenty years. While their model has undoubtedly proven to be successful, an opposing model has become increasingly popular and yielded results of its own. Both models center around different distributions of the salary cap, starting with the portion paid to the starting quarterback. The Patriots dynasty was, in part, made possible due to their use of both models over the course of their dominance. Drafting, organizational culture, and coaching are all among the numerous critical factors in determining a team’s success and it becomes difficult to pinpoint the true source of success for any given team. Ultimately, however, effective management of the cap proves to be a force multiplier; it does not guarantee that a team will be successful, but it helps teams that handle the other variables well sustain their success.

ContributorsBolger, William (Author) / Eaton, John (Thesis director) / Mokwa, Michael (Committee member) / Department of Marketing (Contributor) / Sandra Day O'Connor College of Law (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

Especially during the current COVID-19 pandemic and age of social unrest in the United States, there has been an increasing need for comfort, yet the idea of comfort is quite vague and rarely elaborated upon. To simplify the idea of comfort and communicate the ideas around it effectively, I am

Especially during the current COVID-19 pandemic and age of social unrest in the United States, there has been an increasing need for comfort, yet the idea of comfort is quite vague and rarely elaborated upon. To simplify the idea of comfort and communicate the ideas around it effectively, I am defining comfort as a subset of escapism in which a person escapes to reduce or alleviate feelings of grief or distress. As companies rush to comfort their customers in this current state of uncertainty, marketers are pressed to identify people’s insecurities and comfort them without coming off as insensitive or trite. Current comfort marketing focuses on inspiring nostalgia in its customers, having them recall previous positive experiences or feelings to comfort them. Nostalgic marketing techniques may ease mild grief in some cases, but using them to alleviate severe distress probably will not be as effective, and has contributed to several seemingly out-of-touch “COVID-19 era” commercials.<br/>When addressing comfort, marketers should understand the type and hierarchy of comfort that they are catering to. Not all comforts are equal, in that some comforts make us feel better than others and some do not comfort us at all. A better understanding of how and why comforts change among different individuals, and possibly being able to predict the comfort preference based on a product or service, will help marketers market their goods and services more effectively. By diversifying and specializing comfort marketing using this hierarchical method, marketers will be able to more significantly reach their customers during “uncertain times.”

ContributorsTarpley, Rachel Michelle (Author) / Eaton, John (Thesis director) / Mokwa, Michael (Committee member) / Department of Management and Entrepreneurship (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

The purpose of this paper is to raise awareness about the problem nonrevenue sports face today by analyzing the key factors of the failing Division 1 model and providing some unforeseen consequences in the elimination of nonrevenue sports. The first section will explore the elimination and financial trends of NCAA

The purpose of this paper is to raise awareness about the problem nonrevenue sports face today by analyzing the key factors of the failing Division 1 model and providing some unforeseen consequences in the elimination of nonrevenue sports. The first section will explore the elimination and financial trends of NCAA Division 1 in a historical and contemporary context. The second section will provide the deep-rooted problems associated with collegiate sports. Lastly, the third section will analyze unforeseen consequences for athletic departments that should be accounted for when contemplating the elimination of a nonrevenue program.

ContributorsBelshay, Cade Michael (Author) / Eaton, John (Thesis director) / Mowka, Michael (Committee member) / Department of Finance (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description
Increasing demand for high strength powder metallurgy (PM) steels has resulted in the development of dual phase PM steels. In this work, the effects of thermal aging on the microstructure and mechanical behavior of dual phase precipitation hardened powder metallurgy (PM) stainless steels of varying ferrite-martensite content were examined. Quantitative

Increasing demand for high strength powder metallurgy (PM) steels has resulted in the development of dual phase PM steels. In this work, the effects of thermal aging on the microstructure and mechanical behavior of dual phase precipitation hardened powder metallurgy (PM) stainless steels of varying ferrite-martensite content were examined. Quantitative analyses of the inherent porosity and phase fractions were conducted on the steels and no significant differences were noted with respect to aging temperature. Tensile strength, yield strength, and elongation to fracture all increased with increasing aging temperature reaching maxima at 538oC in most cases. Increased strength and decreased ductility were observed in steels of higher martensite content. Nanoindentation of the individual microconstituents was employed to obtain a fundamental understanding of the strengthening contributions. Both the ferrite and martensite hardness values increased with aging temperature and exhibited similar maxima to the bulk tensile properties. Due to the complex non-uniform stresses and strains associated with conventional nanoindentation, micropillar compression has become an attractive method to probe local mechanical behavior while limiting strain gradients and contributions from surrounding features. In this study, micropillars of ferrite and martensite were fabricated by focused ion beam (FIB) milling of dual phase precipitation hardened powder metallurgy (PM) stainless steels. Compression testing was conducted using a nanoindenter equipped with a flat punch indenter. The stress-strain curves of the individual microconstituents were calculated from the load-displacement curves less the extraneous displacements of the system. Using a rule of mixtures approach in conjunction with porosity corrections, the mechanical properties of ferrite and martensite were combined for comparison to tensile tests of the bulk material, and reasonable agreement was found for the ultimate tensile strength. Micropillar compression experiments of both as sintered and thermally aged material allowed for investigation of the effect of thermal aging.
ContributorsStewart, Jennifer (Author) / Chawla, Nikhilesh (Thesis advisor) / Jiang, Hanqing (Committee member) / Krause, Stephen (Committee member) / Arizona State University (Publisher)
Created2011
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Description
ABSTRACT &eacutetudes; written for violin ensemble, which include violin duets, trios, and quartets, are less numerous than solo &eacutetudes.; These works rarely go by the title "&eacutetude;," and have not been the focus of much scholarly research. Ensemble &eacutetudes; have much to offer students, teachers and

ABSTRACT &eacutetudes; written for violin ensemble, which include violin duets, trios, and quartets, are less numerous than solo &eacutetudes.; These works rarely go by the title "&eacutetude;," and have not been the focus of much scholarly research. Ensemble &eacutetudes; have much to offer students, teachers and composers, however, because they add an extra dimension to the learning, teaching, and composing processes. This document establishes the value of ensemble &eacutetudes; in pedagogy and explores applications of the repertoire currently available. Rather than focus on violin duets, the most common form of ensemble &eacutetude;, it mainly considers works for three and four violins without accompaniment. Concentrating on the pedagogical possibilities of studying &eacutetudes; in a group, this document introduces creative ways that works for violin ensemble can be used as both &eacutetudes; and performance pieces. The first two chapters explore the history and philosophy of the violin &eacutetude; and multiple-violin works, the practice of arranging of solo &eacutetudes; for multiple instruments, and the benefits of group learning and cooperative learning that distinguish ensemble &eacutetude; study from solo &eacutetude; study. The third chapter is an annotated survey of works for three and four violins without accompaniment, and serves as a pedagogical guide to some of the available repertoire. Representing a wide variety of styles, techniques and levels, it illuminates an historical association between violin ensemble works and pedagogy. The fourth chapter presents an original composition by the author, titled Variations on a Scottish Folk Song: &eacutetude; for Four Violins, with an explanation of the process and techniques used to create this ensemble &eacutetude.; This work is an example of the musical and technical integration essential to &eacutetude; study, and demonstrates various compositional traits that promote cooperative learning. Ensemble &eacutetudes; are valuable pedagogical tools that deserve wider exposure. It is my hope that the information and ideas about ensemble &eacutetudes; in this paper and the individual descriptions of the works presented will increase interest in and application of violin trios and quartets at the university level.
ContributorsLundell, Eva Rachel (Contributor) / Swartz, Jonathan (Thesis advisor) / Rockmaker, Jody (Committee member) / Buck, Nancy (Committee member) / Koonce, Frank (Committee member) / Norton, Kay (Committee member) / Arizona State University (Publisher)
Created2011