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- Genre: Academic theses
- Creators: Ryan, Russell
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Description
ABSTRACT Electronics especially mobile electronics such as smart phones, tablet PCs, notebooks and digital cameras are undergoing rapid development nowadays and have thoroughly changed our lives. With the requirement of more transistors, higher power, smaller size, lighter weight and even bendability, thermal management of these devices became one of the key challenges. Compared to active heat management system, heat pipe, which is a passive fluidic system, is considered promising to solve this problem. However, traditional heat pipes have size, weight and capillary limitation. Thus new type of heat pipe with smaller size, lighter weight and higher capillary pressure is needed. Nanofiber has been proved with superior properties and has been applied in multiple areas. This study discussed the possibility of applying nanofiber in heat pipe as new wick structure. In this study, a needleless electrospinning device with high productivity rate was built onsite to systematically investigate the effect of processing parameters on fiber properties as well as to generate nanofiber mat to evaluate its capability in electronics cooling. Polyethylene oxide (PEO) and Polyvinyl Alcohol (PVA) nanofibers were generated. Tensiometer was used for wettability measurement. The results show that independent parameters including spinneret type, working distance, solution concentration and polymer type are strongly correlated with fiber morphology compared to other parameters. The results also show that the fabricated nanofiber mat has high capillary pressure.
ContributorsSun, Tianwei (Author) / Jiang, Hanqing (Thesis advisor) / Yu, Hongyu (Committee member) / Chen, Kangping (Committee member) / Arizona State University (Publisher)
Created2014
Description
From the time it was written, the aria "Largo al factotum" from Rossini's Il barbiere di Siviglia has been performed and ornamented in many different ways. The present study is an inventory and analysis of ornaments sung in 33 recordings from 1900 to 2011 and the major differences that they exhibit one from another. The singers in this study are baritones with international careers, who have performed the role of Figaro either at the Metropolitan Opera (New York) or at La Scala (Milan). The study identifies and tracks some of the changes in the ornamentation of the aria by noting common traits and new approaches across the one hundred eleven years of practice illustrated by the recordings.
ContributorsBriggs, Andrew Nathan (Author) / Mills, Robert (Committee member) / Oldani, Robert (Committee member) / Dreyfoos, Dale (Committee member) / FitzPatrick, Carole (Committee member) / Ryan, Russell (Committee member) / Arizona State University (Publisher)
Created2014
Description
This research focuses on the benefits of using nanocomposites in aerospace structural components to prevent or delay the onset of unique composite failure modes, such as delamination. Analytical, numerical, and experimental analyses were conducted to provide a comprehensive understanding of how carbon nanotubes (CNTs) can provide additional structural integrity when they are used in specific hot spots within a structure. A multiscale approach was implemented to determine the mechanical and thermal properties of the nanocomposites, which were used in detailed finite element models (FEMs) to analyze interlaminar failures in T and Hat section stringers. The delamination that first occurs between the tow filler and the bondline between the stringer and skin was of particular interest. Both locations are considered to be hot spots in such structural components, and failures tend to initiate from these areas. In this research, nanocomposite use was investigated as an alternative to traditional methods of suppressing delamination. The stringer was analyzed under different loading conditions and assuming different structural defects. Initial damage, defined as the first drop in the load displacement curve was considered to be a useful variable to compare the different behaviors in this study and was detected via the virtual crack closure technique (VCCT) implemented in the FE analysis.
Experiments were conducted to test T section skin/stringer specimens under pull-off loading, replicating those used in composite panels as stiffeners. Two types of designs were considered: one using pure epoxy to fill the tow region and another that used nanocomposite with 5 wt. % CNTs. The response variable in the tests was the initial damage. Detailed analyses were conducted using FEMs to correlate with the experimental data. The correlation between both the experiment and model was satisfactory. Finally, the effects of thermal cure and temperature variation on nanocomposite structure behavior were studied, and both variables were determined to influence the nanocomposite structure performance.
Experiments were conducted to test T section skin/stringer specimens under pull-off loading, replicating those used in composite panels as stiffeners. Two types of designs were considered: one using pure epoxy to fill the tow region and another that used nanocomposite with 5 wt. % CNTs. The response variable in the tests was the initial damage. Detailed analyses were conducted using FEMs to correlate with the experimental data. The correlation between both the experiment and model was satisfactory. Finally, the effects of thermal cure and temperature variation on nanocomposite structure behavior were studied, and both variables were determined to influence the nanocomposite structure performance.
ContributorsHasan, Zeaid (Author) / Chattopadhyay, Aditi (Thesis advisor) / Dai, Lenore (Committee member) / Jiang, Hanqing (Committee member) / Rajadas, John (Committee member) / Liu, Yongming (Committee member) / Arizona State University (Publisher)
Created2014
Description
Damage detection in heterogeneous material systems is a complex problem and requires an in-depth understanding of the material characteristics and response under varying load and environmental conditions. A significant amount of research has been conducted in this field to enhance the fidelity of damage assessment methodologies, using a wide range of sensors and detection techniques, for both metallic materials and composites. However, detecting damage at the microscale is not possible with commercially available sensors. A probable way to approach this problem is through accurate and efficient multiscale modeling techniques, which are capable of tracking damage initiation at the microscale and propagation across the length scales. The output from these models will provide an improved understanding of damage initiation; the knowledge can be used in conjunction with information from physical sensors to improve the size of detectable damage. In this research, effort has been dedicated to develop multiscale modeling approaches and associated damage criteria for the estimation of damage evolution across the relevant length scales. Important issues such as length and time scales, anisotropy and variability in material properties at the microscale, and response under mechanical and thermal loading are addressed. Two different material systems have been studied: metallic material and a novel stress-sensitive epoxy polymer.
For metallic material (Al 2024-T351), the methodology initiates at the microscale where extensive material characterization is conducted to capture the microstructural variability. A statistical volume element (SVE) model is constructed to represent the material properties. Geometric and crystallographic features including grain orientation, misorientation, size, shape, principal axis direction and aspect ratio are captured. This SVE model provides a computationally efficient alternative to traditional techniques using representative volume element (RVE) models while maintaining statistical accuracy. A physics based multiscale damage criterion is developed to simulate the fatigue crack initiation. The crack growth rate and probable directions are estimated simultaneously.
Mechanically sensitive materials that exhibit specific chemical reactions upon external loading are currently being investigated for self-sensing applications. The "smart" polymer modeled in this research consists of epoxy resin, hardener, and a stress-sensitive material called mechanophore The mechanophore activation is based on covalent bond-breaking induced by external stimuli; this feature can be used for material-level damage detections. In this work Tris-(Cinnamoyl oxymethyl)-Ethane (TCE) is used as the cyclobutane-based mechanophore (stress-sensitive) material in the polymer matrix. The TCE embedded polymers have shown promising results in early damage detection through mechanically induced fluorescence. A spring-bead based network model, which bridges nanoscale information to higher length scales, has been developed to model this material system. The material is partitioned into discrete mass beads which are linked using linear springs at the microscale. A series of MD simulations were performed to define the spring stiffness in the statistical network model. By integrating multiple spring-bead models a network model has been developed to represent the material properties at the mesoscale. The model captures the statistical distribution of crosslinking degree of the polymer to represent the heterogeneous material properties at the microscale. The developed multiscale methodology is computationally efficient and provides a possible means to bridge multiple length scales (from 10 nm in MD simulation to 10 mm in FE model) without significant loss of accuracy. Parametric studies have been conducted to investigate the influence of the crosslinking degree on the material behavior. The developed methodology has been used to evaluate damage evolution in the self-sensing polymer.
For metallic material (Al 2024-T351), the methodology initiates at the microscale where extensive material characterization is conducted to capture the microstructural variability. A statistical volume element (SVE) model is constructed to represent the material properties. Geometric and crystallographic features including grain orientation, misorientation, size, shape, principal axis direction and aspect ratio are captured. This SVE model provides a computationally efficient alternative to traditional techniques using representative volume element (RVE) models while maintaining statistical accuracy. A physics based multiscale damage criterion is developed to simulate the fatigue crack initiation. The crack growth rate and probable directions are estimated simultaneously.
Mechanically sensitive materials that exhibit specific chemical reactions upon external loading are currently being investigated for self-sensing applications. The "smart" polymer modeled in this research consists of epoxy resin, hardener, and a stress-sensitive material called mechanophore The mechanophore activation is based on covalent bond-breaking induced by external stimuli; this feature can be used for material-level damage detections. In this work Tris-(Cinnamoyl oxymethyl)-Ethane (TCE) is used as the cyclobutane-based mechanophore (stress-sensitive) material in the polymer matrix. The TCE embedded polymers have shown promising results in early damage detection through mechanically induced fluorescence. A spring-bead based network model, which bridges nanoscale information to higher length scales, has been developed to model this material system. The material is partitioned into discrete mass beads which are linked using linear springs at the microscale. A series of MD simulations were performed to define the spring stiffness in the statistical network model. By integrating multiple spring-bead models a network model has been developed to represent the material properties at the mesoscale. The model captures the statistical distribution of crosslinking degree of the polymer to represent the heterogeneous material properties at the microscale. The developed multiscale methodology is computationally efficient and provides a possible means to bridge multiple length scales (from 10 nm in MD simulation to 10 mm in FE model) without significant loss of accuracy. Parametric studies have been conducted to investigate the influence of the crosslinking degree on the material behavior. The developed methodology has been used to evaluate damage evolution in the self-sensing polymer.
ContributorsZhang, Jinjun (Author) / Chattopadhyay, Aditi (Thesis advisor) / Dai, Lenore (Committee member) / Jiang, Hanqing (Committee member) / Papandreou-Suppappola, Antonia (Committee member) / Rajadas, John (Committee member) / Arizona State University (Publisher)
Created2014
Description
The commissioning and recording of music from living composers is a very important tradition in the art of music. The ability to work with living composers gives the performer insight into the music that is far beyond reading the notes on the page. For my research paper, I commissioned two new works for the cello by the composers Joseph Hallman and Christian Asplund, in an effort to continue adding great pieces to the cello repertoire. This paper documents my experiences in finding and working with selected composers. It includes detailed descriptions of the pieces with practice and performance suggestions as well as recordings of the pieces. Commissioning new works often creates many first-hand artistic decisions for the performer as well as many new technical difficulties on the instrument. The two pieces commissioned offer insight into two different instrumentations: the sonata for cello and piano, and a solo cello suite. In this paper I describe various important aspects of these compositions and point out ways to make informed artistic decisions when approaching form, harmony, motive, and extended techniques on the cello. Providing this information on commissioning and collaborating with living composers will help continue this tradition into the future for classical music.
ContributorsKesler, Michelle (Contributor) / Landschoot, Thomas (Committee member) / Carpenter, Ellon (Committee member) / McLin, Katherine (Committee member) / Spring, Robert (Committee member) / Ryan, Russell (Committee member) / Arizona State University (Publisher)
Created2014
Description
Geirr Tveitt (1908-1981) was a central figure of the national movement in Norwegian cultural life during the 1930s. He studied composition with masters such as Arthur Honegger, Heitor Villa-Lobos, and Nadia Boulanger, achieving international acclaim for many of his works. However, his native Norway was slow to follow this praise, as post-World War II intellectuals disregarded anything that resembled nationalism. Tveitt's music was considered obsolete. He became isolated and withdrawn and died in 1981 after a house fire destroyed the manuscripts of nearly three hundred opuses, leaving only a handful of works, some of which were not yet published. Tveitt was raised in a remote part of Norway where the folk tradition was strong. Because of his close ties with the Hardanger community, he was able to bring to light many undiscovered folk tunes and exceptional practices. Tveitt utilizes this first-hand knowledge in his works for solo piano, and successfully combines them with his roots in both Germanic and Nordic traditions, eventually becoming a well-known and respected composer to the Norwegian people. However, he remains virtually unknown to the rest of the world. All of his music was deeply influenced by folk traditions and instruments. Techniques such as planing, drones, modal scales and passages, ornamentation, and simple melodies are pervasive in each piece, and are often the building blocks of main themes and motives. Because of the ambiguity of the status of many works, this paper examines only his published works for solo piano. Discussions of each piece will focus on folk influences within each work, including basic form, texture, and pianistic concerns.
ContributorsHunter, Karali (Author) / Meir, Baruch (Thesis advisor) / Carpenter, Ellon (Committee member) / Ryan, Russell (Committee member) / Arizona State University (Publisher)
Created2014
Description
This study examines the effectiveness of various types of alternative resources in organ building in order to determine whether a change to more sustainable materials would benefit or hinder the overall sound production of the instrument. The qualities of the metals and woods currently used in organ production (e.g. lead, walnut, etc.) have been prized for centuries, so the substitution of different, more sustainable materials must be considered with regards to the sonic alterations, as well as the financial implications, of using alternatives to make the organ more “green.”
Five organ builders were interviewed regarding their views on sustainable materials. In addition, the author consulted the websites of nine national and four international organ builders for information about sustainability, indicating that each organ builder defines the term somewhat differently. Decisions on the woods and metals to be used in building or refurbishing an existing organ are based more on the visual appearance, the sound desired, and the potential for reuse of existing materials. A number of sustainability practices are currently in use by organ builders in the United States and Europe. These include the reuse of transportation boxes, efforts towards recycled metal and wood pipework, and the use of high efficiency lighting.
The investigations into sustainable practice that are presented here document a variety of approaches to sustainability in organ building in the United States, Canada and Europe. This research should assist in the evaluation of further efforts to conserve valuable resources while ensuring the high quality of sound that has characterized the organ throughout its long history.
Five organ builders were interviewed regarding their views on sustainable materials. In addition, the author consulted the websites of nine national and four international organ builders for information about sustainability, indicating that each organ builder defines the term somewhat differently. Decisions on the woods and metals to be used in building or refurbishing an existing organ are based more on the visual appearance, the sound desired, and the potential for reuse of existing materials. A number of sustainability practices are currently in use by organ builders in the United States and Europe. These include the reuse of transportation boxes, efforts towards recycled metal and wood pipework, and the use of high efficiency lighting.
The investigations into sustainable practice that are presented here document a variety of approaches to sustainability in organ building in the United States, Canada and Europe. This research should assist in the evaluation of further efforts to conserve valuable resources while ensuring the high quality of sound that has characterized the organ throughout its long history.
ContributorsGregoire, Jonathan M (Author) / Marshall, Kimberly (Thesis advisor) / Feisst, Sabine (Committee member) / Ryan, Russell (Committee member) / Arizona State University (Publisher)
Created2014
Description
This dissertation presents my work on development of deformable electronics using microelectromechanical systems (MEMS) based fabrication technologies. In recent years, deformable electronics are coming to revolutionize the functionality of microelectronics seamlessly with their application environment, ranging from various consumer electronics to bio-medical applications. Many researchers have studied this area, and a wide variety of devices have been fabricated. One traditional way is to directly fabricate electronic devices on flexible substrate through low-temperature processes. These devices suffered from constrained functionality due to the temperature limit. Another transfer printing approach has been developed recently. The general idea is to fabricate functional devices on hard and planar substrates using standard processes then transferred by elastomeric stamps and printed on desired flexible and stretchable substrates. The main disadvantages are that the transfer printing step may limit the yield. The third method is "flexible skins" which silicon substrates are thinned down and structured into islands and sandwiched by two layers of polymer. The main advantage of this method is post CMOS compatible. Based on this technology, we successfully fabricated a 3-D flexible thermal sensor for intravascular flow monitoring. The final product of the 3-D sensor has three independent sensing elements equally distributed around the wall of catheter (1.2 mm in diameter) with 120° spacing. This structure introduces three independent information channels, and cross-comparisons among all readings were utilized to eliminate experimental error and provide better measurement results. The novel fabrication and assembly technology can also be applied to other catheter based biomedical devices. A step forward inspired by the ancient art of folding, origami, which creating three-dimensional (3-D) structures from two-dimensional (2-D) sheets through a high degree of folding along the creases. Based on this idea, we developed a novel method to enable better deformability. One example is origami-enabled silicon solar cells. The solar panel can reach up to 644% areal compactness while maintain reasonable good performance (less than 30% output power density drop) upon 40 times cyclic folding/unfolding. This approach can be readily applied to other functional devices, ranging from sensors, displays, antenna, to energy storage devices.
ContributorsTang, Rui (Author) / Yu, Hongyu (Thesis advisor) / Jiang, Hanqing (Committee member) / Pan, George (Committee member) / Goryll, Michael (Committee member) / Arizona State University (Publisher)
Created2014
Description
By studying of a piece of music paired with specific artwork from the time and place of its composition, one can learn more about the character and artistic merits of both the art and music, as well as their relationship to the culture in which they were created. It is the purpose of this paper to examine one specific idea within this vein of interdisciplinary study. This study explores the presentation of American visual art from the 1920s alongside Dupré's Variations sur un Noël, Op. 20. This correlation provides a platform for deeper insight into the composition. The sights and sounds of America that Dupré observed while composing his variation set, captured in artwork from that period, illustrate some of the unique and distinguishing features of the musical work. This study also explores the history and culture around music and art in the 1920's, as well as some of the existing research on the relationship between music and visual art.
ContributorsSnavley, Ashley Nicole (Author) / Marshall, Kimberlt (Thesis advisor) / Rogers, Rodney (Committee member) / Ryan, Russell (Committee member) / Arizona State University (Publisher)
Created2014
Description
Fission products in nuclear fuel pellets can affect fuel performance as they change the fuel chemistry and structure. The behavior of the fission products and their release mechanisms are important to the operation of a power reactor. Research has shown that fission product release can occur through grain boundary (GB) at low burnups. Early fission gas release models, which assumed spherical grains with no effect of GB diffusion, did not capture the early stage of the release behavior well. In order to understand the phenomenon at low burnup and how it leads to the later release mechanism, a microstructurally explicit model is needed. This dissertation conducted finite element simulations of the transport behavior using 3-D microstructurally explicit models. It looks into the effects of GB character, with emphases on conditions that can lead to enhanced effective diffusion. Moreover, the relationship between temperature and fission product transport is coupled to reflect the high temperature environment.
The modeling work began with 3-D microstructure reconstruction for three uranium oxide samples with different oxygen stoichiometry: UO2.00 UO2.06 and UO2.14. The 3-D models were created based on the real microstructure of depleted UO2 samples characterized by Electron Backscattering Diffraction (EBSD) combined with serial sectioning. Mathematical equations on fission gas diffusion and heat conduction were studied and derived to simulate the fission gas transport under GB effect. Verification models showed that 2-D elements can be used to model GBs to reduce the number of elements. The effect of each variable, including fuel stoichiometry, temperature, GB diffusion, triple junction diffusion and GB thermal resistance, is verified, and they are coupled in multi-physics simulations to study the transport of fission gas at different radial location of a fuel pellet. It was demonstrated that the microstructural model can be used to incorporate the effect of different physics to study fission gas transport. The results suggested that the GB effect is the most significant at the edge of fuel pellet where the temperature is the lowest. In the high temperature region, the increase in bulk diffusivity due to excess oxygen diminished the effect of GB diffusion.
The modeling work began with 3-D microstructure reconstruction for three uranium oxide samples with different oxygen stoichiometry: UO2.00 UO2.06 and UO2.14. The 3-D models were created based on the real microstructure of depleted UO2 samples characterized by Electron Backscattering Diffraction (EBSD) combined with serial sectioning. Mathematical equations on fission gas diffusion and heat conduction were studied and derived to simulate the fission gas transport under GB effect. Verification models showed that 2-D elements can be used to model GBs to reduce the number of elements. The effect of each variable, including fuel stoichiometry, temperature, GB diffusion, triple junction diffusion and GB thermal resistance, is verified, and they are coupled in multi-physics simulations to study the transport of fission gas at different radial location of a fuel pellet. It was demonstrated that the microstructural model can be used to incorporate the effect of different physics to study fission gas transport. The results suggested that the GB effect is the most significant at the edge of fuel pellet where the temperature is the lowest. In the high temperature region, the increase in bulk diffusivity due to excess oxygen diminished the effect of GB diffusion.
ContributorsLim, Harn Chyi (Author) / Peralta, Pedro (Thesis advisor) / Jiang, Hanqing (Committee member) / Solanki, Kiran (Committee member) / Arizona State University (Publisher)
Created2014