ASU Electronic Theses and Dissertations
This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.
In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.
Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.
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- Creators: Mobasher, Barzin
- Creators: Margolis, Eric
Description
The growing population of American Indian students who attend off-reservation school has been under researched. This absence in American Indian education research, their unique needs, and their growing numbers warrant more attention. To address this absence in education research literature, this study captures the experiences of American Indian students in an off-reservation high school. Through Social Reproduction Theory and Cultural Capital Theory this qualitative study makes known the varying ways that American Indian students in off-reservation high schools comply and resist formal schooling. Through interviews and observations of these students, in addition their teachers and administrators, I document and interpret their experiences. The data suggest that American Indian students strongly connect to and use their tribal identities to negotiate school. By recognizing the rules of the school, these students employ different forms of cultural and social capital, specifically the importance of space and forms of communication. Even though their high school has a high population of American Indian students, they continue to experience challenges in academic success through stereotypical assumptions, expected roles, and structural barriers. Illustrating student identity as effects of the social reproduction process clearly demonstrates resistance, compliance, and agency of these students in their high school.
ContributorsBegay, Victor H (Author) / Margolis, Eric (Thesis advisor) / Mccarty, Teresa L. (Committee member) / Appleton, Nicholas (Committee member) / Arizona State University (Publisher)
Created2014
Description
The main objective of this study is to numerically investigate: (i) the ionic transport, especially chloride ion penetration into cementitious materials under imposed electric fields, and (ii) moisture transport through cracked concretes as a function of the crack geometry. Numerical methods were implemented to simulate the ionic transport process, based on coupling the Nernst-Planck equation and Poisson's equation to account for transport dominated by electromigration. This mathematical model was also modified to account for the chloride binding mechanism (physical and chemical trapping of chlorides by the cement hydrates) and the concentration dependence of the diffusion coefficient of each ion in the transport process. To validate the numerical model, experimental data from a companion work was used in this study. The non-steady state migration test, which is one of the common accelerated chloride ion transport test, is numerically simulated. The simulation provides a linear relationship between ionic concentration and ionic flux, which indicates that the diffusion part is negligible under a strong external voltage environment. The numerical models along with adjustments for the concentration-dependent diffusion coefficients, a pore structure factor (from electrical measurements) and chloride binding considerations are found to be successful in predicting the chloride penetration depth into plain and modified concretes under imposed electrical potentials. Moisture transport through cracked concrete was examined in the second part of this thesis. To better understand the crack's influence on the permeability, modified Louis' equation was chosen to relate the permeability with crack characteristics. 3D concrete crack models were developed using a MATLAB program with distinct crack tortuosities, roughnesses and sizes. As a comparison, Navier-Stokes equation and the Lattice Boltzmann method were also applied on the 3D model of the cracked concrete to evaluate their permeability. The methodology developed here is expected to be useful in understanding the influence of cracking on moisture transport, and when properly coupled with an ionic transport model that will be further developed, helps comprehensively understand the coupling effects of moisture and ionic transport on deterioration in concrete structures.
ContributorsYang, Pu (Author) / Neithalath, Narayanan (Thesis advisor) / Dharmarajan, Subramaniam (Committee member) / Mobasher, Barzin (Committee member) / Arizona State University (Publisher)
Created2014
Description
The history of the American Old West has frequently been romanticized and idealized. This dissertation study explored four Arizona towns that developed during the era of the American Old West: Tombstone, Jerome, Oatman, and Globe. The study broadly examined issues of remembering/forgetting and historical authenticity/myth. It specifically analyzed historic tourist destinations as visual phenomenon: seeking to understand how town histories were visually communicated to contemporary tourists and what role historically-grounded visual narratives played in the overall tourist experience. The study utilized a visual methodology to organize and structure qualitative data collection and analysis; it incorporated visual data from historic and contemporary photographs and textual data from observations and interviews. Through a careful exploration of each town's past and present, the research proposed a measure to assess how the strength of visual connections between past and present impacted tourist impressions of each town. The analysis suggested that, due to a general lack of historic knowledge, tourist impressions were more closely connected to contemporary experiences and prior expectations of the American Old West than to historically-grounded visual narratives.
ContributorsMcMullen, Melissa (Author) / Margolis, Eric (Thesis advisor) / Martin, Judith (Committee member) / Rowe, Jeremy (Committee member) / Arizona State University (Publisher)
Created2014
Description
The main objective of this study is to investigate drying properties and plastic shrinkage cracking resistance of fresh cement-based pastes reinforced with fibers and textiles. Naturally occurring mineral wollastonite has been studied independently as well as in combination with AR-glass textile. A series of blended mixes with Portland cement and wollastonite nano-fibers were developed and tested under low vacuum conditions to simulate severe evaporation conditions and expedite the drying process causing plastic shrinkage cracks. Cumulative moisture loss, evaporation rates, and diffusivity were analyzed by means of a 2-stage diffusion simulation approach, developed previously in Arizona State University. Effect of fiber-matrix interaction on the transport properties of the composite were evaluated using the existing approach. Morphology of the cracked surface was investigated by the means of image analysis wherein length, width, area and density of the cracks were computed to help characterize the contribution of fiber and textile in the cracking phenomenon. Additionally, correlation between cumulative moisture loss and crack propagation was attempted. The testing procedures and associated analytical methods were applied to evaluate effectiveness of four wollastonite fiber sizes and also a hybrid reinforcement system with alkali-resistant glass (ARG) textile in improving shrinkage cracking related parameters. Furthermore, the experimental and analytical approach was extended to magnified version of the existing shrinkage testing set-up to study the size effect of these composites when subjected to matching drying conditions. Different restraining mechanisms were used to study the simulation of the cracking phenomena on a larger specimen. Paste and mortar formulations were developed to investigate size effect on shrinkage resistance of cementitious composites.
ContributorsKachala, Robert (Author) / Mobasher, Barzin (Thesis advisor) / Dharmarajan, Subramaniam (Committee member) / Neithalath, Narayanan (Committee member) / Arizona State University (Publisher)
Created2014
Description
This study focuses on the principles of caring and respect for persons, and how they are manifested in the preschool classroom. Caring and respect are core ethical principles. When applied, they inform our thinking and guide our behavior. Leading ethicists, including Immanuel Kant and Nel Noddings, have argued that caring and respect are vital elements in ethical human relationships. This dissertation is at the forefront of a new line of inquiry which is seeking to connect the philosophical with the empirical in ways that can be illuminating for both, and for education research and practice more generally. The study connects ethical theory with a qualitative analysis of how the principles of caring and respect do and do not manifest in pre-K classrooms. The empirical portion of this study is a secondary data analysis of classroom videos collected for a large-scale research project conducted by the National Center for Research on Early Childhood Education (NCRECE). Using maximum variation sampling, I identified six preschool classrooms to examine in regard to my research questions and identify observable behaviors associated with caring and respectful interactions. These video samples of teachers interactions with small and larger groups of children were then transcribed, described, analyzed, and discussed through the lens of the ethics of care and respect for persons. The study found that caring and respect for persons were either not demonstrated or were demonstrated in very limited ways in the observable behaviors of teachers in the samples of preschool classrooms under examination. These findings point to the importance of connecting ethics and practice in educational research and the professional development of early childhood educators.
ContributorsPaxton, Kate (Author) / Margolis, Eric (Thesis advisor) / Swadener, Beth (Thesis advisor) / Fischman, Gustavo (Committee member) / Arizona State University (Publisher)
Created2014
Description
Concrete is the most widely used infrastructure material worldwide. Production of portland cement, the main binding component in concrete, has been shown to require significant energy and account for approximately 5-7% of global carbon dioxide production. The expected continued increased use of concrete over the coming decades indicates this is an ideal time to implement sustainable binder technologies. The current work aims to explore enhanced sustainability concretes, primarily in the context of limestone and flow. Aspects such as hydration kinetics, hydration product formation and pore structure add to the understanding of the strength development and potential durability characteristics of these binder systems. Two main strategies for enhancing this sustainability are explored in this work: (i) the use of high volume limestone in combination with other alternative cementitious materials to decrease the portland cement quantity in concrete and (ii) the use of geopolymers as the binder phase in concrete. The first phase of the work investigates the use of fine limestone as cement replacement from the perspective of hydration, strength development, and pore structure. The nature of the potential synergistic benefit of limestone and alumina will be explored. The second phase will focus on the rheological characterization of these materials in the fresh state, as well as a more general investigation of the rheological characterization of suspensions. The results of this work indicate several key ideas. (i) There is a potential synergistic benefit for strength, hydration, and pore structure by using alumina and in portland limestone cements, (ii) the limestone in these systems is shown to react to some extent, and fine limestone is shown to accelerate hydration, (iii) rheological characteristics of cementitious suspensions are complex, and strongly dependent on several key parameters including: the solid loading, interparticle forces, surface area of the particles present, particle size distribution of the particles, and rheological nature of the media in which the particles are suspended, and (iv) stress plateau method is proposed for the determination of rheological properties of concentrated suspensions, as it more accurately predicts apparent yield stress and is shown to correlate well with other viscoelastic properties of the suspensions.
ContributorsVance, Kirk (Author) / Neithalath, Narayanan (Thesis advisor) / Rajan, Subramaniam D. (Committee member) / Mobasher, Barzin (Committee member) / Chawla, Nikhilesh (Committee member) / Marzke, Robert (Committee member) / Arizona State University (Publisher)
Created2014
Description
Guided by Clifford Geertz's notion of culture as symbolic stories people tell themselves about themselves, the purpose of this study is to examine how youth in an urban area of Phoenix, AZ experience collectively creating and performing original documentary theatre. I pay attention to the ways youth participants--also known as artist-researchers--construct, perform, and/or perceive their identities as they practice drama techniques including improvisation, physical theatre, and Theatre of the Oppressed for the purposes of making docutheatre for social justice. First the artist-researchers chose the topics for their play. Next, they learned and applied drama and research skills to gather and examine data sources used to construct a script that explores hiding and exposure. In the process of sharing and gathering true stories our unique docutheatre-making culture was created. This multimodal qualitative research case study draws upon the genres of arts-based research and visual ethnography as primary modes of data collection and interpretation. Narrative description and the ethnodramatic mode of representation are used in conjunction with still images and this study's companion website (www.meant2see.com) to report research findings. Primary data sources include participant observation fieldnotes, over twenty hours of recorded video footage, photographs, and the project's original script and performance of To Be What's Not Meant to See . Further data include journal entries, drawings, and social media. All data were coded using In Vivo and Process Coding methods and analyzed through a cultural studies lens. Codes were sorted into phenomenological categories representative of recurring ideas and themes. Assertions were then solidified once specific key linkages were constructed. This study's key assertions are: Key Assertion 1: Participation in devising documentary social justice theatre influences and affects the construction, perception, and/or performance of urban youth identities through profound connections made with interviewees during the interview process and through the collection of true stories that provide new information and rare opportunities for self-reflection and self-realization; Key Assertion 2: Portions of the roles urban youth play in their identity narratives are disguised or hidden--purposefully, reluctantly, and/or subconsciously--in order to appeal to friends, families, or the codes of dominant culture.
ContributorsGiannone, Enza (Author) / Saldana, Johnny (Thesis advisor) / Etheridge Woodson, Stephani (Committee member) / Margolis, Eric (Committee member) / Arizona State University (Publisher)
Created2014
Description
Working with participants in schools for highly gifted students, this study asked adolescents to create a digital story to address the prompt, "How has your life changed since coming to this school?" Participant interviews were conducted in an attempt to determine how gifted students view their educational experiences and how those experiences influence the current development of self-identity. Digital story creation and photo elicitation methods were chosen in an effort to remove researcher bias and allow participant voices to be heard more accurately. Parent and educator interviews were also conducted. Data analysis was completed using narrative construction methods. Findings include several themes among participant self-identity influences including how labels affect participant's view of themselves, perfectionism and competitive drive function in each gifted child, necessity of intellectual challenge, appropriate learning environment helps to create self-confidence and self-identity, and grades are more important than learning for knowledge.
ContributorsHart, Courtney Brook (Author) / Ganesh, Tirupalavanam G. (Thesis advisor) / Margolis, Eric (Thesis advisor) / Sandlin, Jennifer (Committee member) / Arizona State University (Publisher)
Created2014
Description
The main objective of this study is to investigate the behaviour and applications of strain hardening cement composites (SHCC). Application of SHCC for use in slabs of common configurations was studied and design procedures are prepared by employing yield line theory and integrating it with simplified tri-linear model developed in Arizona State University by Dr. Barzin Mobasher and Dr. Chote Soranakom. Intrinsic material property of moment-curvature response for SHCC was used to derive the relationship between applied load and deflection in a two-step process involving the limit state analysis and kinematically admissible displacements. For application of SHCC in structures such as shear walls, tensile and shear properties are necessary for design. Lot of research has already been done to study the tensile properties and therefore shear property study was undertaken to prepare a design guide. Shear response of textile reinforced concrete was investigated based on picture frame shear test method. The effects of orientation, volume of cement paste per layer, planar cross-section and volume fraction of textiles were investigated. Pultrusion was used for the production of textile reinforced concrete. It is an automated set-up with low equipment cost which provides uniform production and smooth final surface of the TRC. A 3-D optical non-contacting deformation measurement technique of digital image correlation (DIC) was used to conduct the image analysis on the shear samples by means of tracking the displacement field through comparison between the reference image and deformed images. DIC successfully obtained full-field strain distribution, displacement and strain versus time responses, demonstrated the bonding mechanism from perspective of strain field, and gave a relation between shear angle and shear strain.
ContributorsAswani, Karan (Author) / Mobasher, Barzin (Thesis advisor) / Dharmarajan, Subramaniam (Committee member) / Neithalath, Narayanan (Committee member) / Arizona State University (Publisher)
Created2014
Description
Laminated composite materials are used in aerospace, civil and mechanical structural systems due to their superior material properties compared to the constituent materials as well as in comparison to traditional materials such as metals. Laminate structures are composed of multiple orthotropic material layers bonded together to form a single performing part. As such, the layup design of the material largely influences the structural performance. Optimization techniques such as the Genetic Algorithm (GA), Differential Evolution (DE), the Method of Feasible Directions (MFD), and others can be used to determine the optimal laminate composite material layup. In this thesis, sizing, shape and topology design optimization of laminated composites is carried out. Sizing optimization, such as the layer thickness, topology optimization, such as the layer orientation and material and the number of layers present, and shape optimization of the overall composite part contribute to the design optimization process of laminates. An optimization host program written in C++ has been developed to implement the optimization methodology of both population based and numerical gradient based methods. The performance of the composite structural system is evaluated through explicit finite element analysis of shell elements carried out using LS-DYNA. Results from numerical examples demonstrate that optimization design processes can significantly improve composite part performance through implementation of optimum material layup and part shape.
ContributorsMika, Krista (Author) / Rajan, Subramaniam D. (Thesis advisor) / Neithalath, Narayanan (Committee member) / Mobasher, Barzin (Committee member) / Arizona State University (Publisher)
Created2014