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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Description
Metal hydride materials have been intensively studied for hydrogen storage applications. In addition to potential hydrogen economy applications, metal hydrides offer a wide variety of other interesting properties. For example, hydrogen-dominant materials, which are hydrides with the highest hydrogen content for a particular metal/semimetal composition, are predicted to display high-temperature superconductivity. On the other side of the spectrum are hydrides with small amounts of hydrogen (0.1 - 1 at.%) that are investigated as viable magnetic, thermoelectric or semiconducting materials. Research of metal hydride materials is generally important to gain fundamental understanding of metal-hydrogen interactions in materials. Hydrogenation of Zintl phases, which are defined as compounds between an active metal (alkali, alkaline earth, rare earth) and a p-block metal/semimetal, were attempted by a hot sintering method utilizing an autoclave loaded with gaseous hydrogen (< 9 MPa). Hydride formation competes with oxidative decomposition of a Zintl phase. The oxidative decomposition, which leads to a mixture of binary active metal hydride and p-block element, was observed for investigated aluminum (Al) and gallium (Ga) containing Zintl phases. However, a new phase Li2Al was discovered when Zintl phase precursors were synthesized. Using the single crystal x-ray diffraction (SCXRD), the Li2Al was found to crystallize in an orthorhombic unit cell (Cmcm) with the lattice parameters a = 4.6404(8) Å, b = 9.719(2) Å, and c = 4.4764(8) Å. Increased demand for materials with improved properties necessitates the exploration of alternative synthesis methods. Conventional metal hydride synthesis methods, like ball-milling and autoclave technique, are not responding to the demands of finding new materials. A viable alternative synthesis method is the application of high pressure for the preparation of hydrogen-dominant materials. Extreme pressures in the gigapascal ranges can open access to new metal hydrides with novel structures and properties, because of the drastically increased chemical potential of hydrogen. Pressures up to 10 GPa can be easily achieved using the multi-anvil (MA) hydrogenations while maintaining sufficient sample volume for structure and property characterization. Gigapascal MA hydrogenations using ammonia borane (BH3NH3) as an internal hydrogen source were employed in the search for new hydrogen-dominant materials. Ammonia borane has high gravimetric volume of hydrogen, and additionally the thermally activated decomposition at high pressures lead to a complete hydrogen release at reasonably low temperature. These properties make ammonia borane a desired hydrogen source material. The missing member Li2PtH6 of the series of A2PtH6 compounds (A = Na to Cs) was accessed by employing MA technique. As the known heavier analogs, the Li2PtH6 also crystallizes in a cubic K2PtCl6-type structure with a cell edge length of 6.7681(3) Å. Further gigapascal hydrogenations afforded the compounds K2SiH6 and Rb2SiH6 which are isostructural to Li2PtH6. The cubic K2SiH6 and Rb2SiH6 are built from unique hypervalent SiH62- entities with the lattice parameters of 7.8425(9) and 8.1572(4) Å, respectively. Spectroscopic analysis of hexasilicides confirmed the presence of hypervalent bonding. The Si-H stretching frequencies at 1550 cm-1 appeared considerably decreased in comparison with a normal-valent (2e2c) Si-H stretching frequencies in SiH4 at around 2200 cm-1. However, the observed stretching modes in hypervalent hexasilicides were in a reasonable agreement with Ph3SiH2- (1520 cm-1) where the hydrogen has the axial (3e4c bonded) position in the trigoal bipyramidal environment.
ContributorsPuhakainen, Kati (Author) / Häussermann, Ulrich (Thesis advisor) / Seo, Dong (Thesis advisor) / Kouvetakis, John (Committee member) / Wolf, George (Committee member) / Arizona State University (Publisher)
Created2013
Description
In the last years of the twentieth century, while the narrative of women in other Latin American countries has received critical attention, Bolivian women's narrative has been widely ignored. The fact that the voice of Bolivian women in Latin American feminist discourse is rarely discussed in Latin American criticism is enough to justify the present study. This work focuses on three prominent Bolivian writers: Gaby Vallejos, Giovanna Rivero Santa Cruz, and Erika Bruzonic. The short stories of these three authors are characterized by accentuating certain telluric features revealed in the background of their feminine/feminist narratives. At the same time, based on the American and European feminist literary critique, this work analyzes the feminine/feminist themes mounted in the narrative of these authors. Gaby Vallejos, with a cinematic style, chronicles the life and customs of the "valluno" context, building a mosaic of different voices in dialogue. Her topics revolve around binaries: life-death, and pain and pleasure, voicing condemnation for a patriarchal society. Ericka Bruzonic deals with women and identity, memory and the breaking of lineage as an imposing structure. Her themes are built around the cosmopolitism of "paceña" urban life, and her voice transgresses the binomials established by a patriarchal society. Finally Giovanna Rivero Santa Cruz takes the life and customs of the Santa Cruz and the Guarani culture and her plots weave these elements reaching for myths and taboos, involving the reader into her stories. In this manner, her narrative makes an incursion into the conscious and unconscious realm of the readers questioning their wealth of moral and social values, their notions of heterosexuality, and sexual taboos. The three writers, with different narrative styles yet dialogical, narrate various experiences of women from different regions, social classes, ages, education, and sexual orientations. Our authors give high value to the word and the body embedded in the culture, thereby affirming their woman's voice as Bolivians and their literary presence in the context of Latin American literature.
ContributorsLopez, Norma (Author) / Urioste-Ascorra, Carmen (Thesis advisor) / Tompkins, Cynthia (Committee member) / Rosales, Jesus (Committee member) / Arizona State University (Publisher)
Created2013
Description
Topological insulators with conducting surface states yet insulating bulk states have generated a lot of interest amongst the physics community due to their varied characteristics and possible applications. Doped topological insulators have presented newer physical states of matter where topological order co&ndashexists; with other physical properties (like magnetic order). The electronic states of these materials are very intriguing and pose problems and the possible solutions to understanding their unique behaviors. In this work, we use Electron Energy Loss Spectroscopy (EELS) – an analytical TEM tool to study both core&ndashlevel; and valence&ndashlevel; excitations in Bi2Se3 and Cu(doped)Bi2Se3 topological insulators. We use this technique to retrieve information on the valence, bonding nature, co-ordination and lattice site occupancy of the undoped and the doped systems. Using the reference materials Cu(I)Se and Cu(II)Se we try to compare and understand the nature of doping that copper assumes in the lattice. And lastly we utilize the state of the art monochromated Nion UltraSTEM 100 to study electronic/vibrational excitations at a record energy resolution from sub-nm regions in the sample.
ContributorsSubramanian, Ganesh (Author) / Spence, John (Thesis advisor) / Jiang, Nan (Committee member) / Chen, Tingyong (Committee member) / Chan, Candace (Committee member) / Arizona State University (Publisher)
Created2013
Community-based development: scaling up the correct use of misoprostol at home births in Afghanistan
Description
Globally, more than 350 000 women die annually from complications during pregnancy and childbirth (UNFPA, 2011). Nearly 99% of these, according to World Health Organization (WHO) trends (2010) occur in the developing world outside of a hospital setting with limited resources including emergency care (WHO, 2012; UNFPA, 2011). The most prevalent cause of death is postpartum hemorrhage (PPH), accounting for 25% of deaths according to WHO statistics (2012). Conditions in Afghanistan are reflective of the scope and magnitude of the problem. In Afghanistan, maternal mortality is thought to be among the highest in the world. The Afghan Mortality Survey (AMS) data implies that one Afghan woman dies about every 2 hours from pregnancy-related causes (AMS, 2010). Lack of empowerment, education and access to health care resources increase a woman's risk of dying during pregnancy (AMS, 2010). This project aims to investigate the prospects of scaling-up the correct use of misoprostol, a prostaglandin E1 analogue, to treat PPH in developing countries where skilled assistance and resources are scant. As there has been little published on the lessons learned from programs already in place, this study is experience-driven, based on the knowledge of industry experts. This study employs a concurrent triangulation approach to synthesize quantitative data obtained from previous studies with qualitative information gathered through the testimonies of key personnel who participated in pilot programs involving misoprostol. There are many obstacles to scaling-up training initiatives in Afghanistan and other low-resource areas. The analysis concludes that the most crucial factors for scaling-up community-based programs include: more studies analyzing lessons learns from community driven approaches; stronger partnerships with community health care workers; overcoming barriers like association with abortion, misuse and product issues; and a heightened global and community awareness of the severity of PPH without treatment. These results have implications for those who actively work in Afghanistan to promote maternal health and other countries that may use Afghanistan's work as a blueprint for reducing maternal mortality through community-based approaches. Keywords: Afghanistan, community-based interventions, community-driven, maternal mortality, MDG5, misoprostol, postpartum hemorrhage, reproduction, scale-up
ContributorsCristy, Candice (Author) / Grossman, Gary (Thesis advisor) / Parmentier, Mary-Jane (Committee member) / Byrd, Denise (Committee member) / Arizona State University (Publisher)
Created2013
Description
The alkali activation of aluminosilicate materials as binder systems derived from industrial byproducts have been extensively studied due to the advantages they offer in terms enhanced material properties, while increasing sustainability by the reuse of industrial waste and byproducts and reducing the adverse impacts of OPC production. Fly ash and ground granulated blast furnace slag are commonly used for their content of soluble silica and aluminate species that can undergo dissolution, polymerization with the alkali, condensation on particle surfaces and solidification. The following topics are the focus of this thesis: (i) the use of microwave assisted thermal processing, in addition to heat-curing as a means of alkali activation and (ii) the relative effects of alkali cations (K or Na) in the activator (powder activators) on the mechanical properties and chemical structure of these systems. Unsuitable curing conditions instigate carbonation, which in turn lowers the pH of the system causing significant reductions in the rate of fly ash activation and mechanical strength development. This study explores the effects of sealing the samples during the curing process, which effectively traps the free water in the system, and allows for increased aluminosilicate activation. The use of microwave-curing in lieu of thermal-curing is also studied in order to reduce energy consumption and for its ability to provide fast volumetric heating. Potassium-based powder activators dry blended into the slag binder system is shown to be effective in obtaining very high compressive strengths under moist curing conditions (greater than 70 MPa), whereas sodium-based powder activation is much weaker (around 25 MPa). Compressive strength decreases when fly ash is introduced into the system. Isothermal calorimetry is used to evaluate the early hydration process, and to understand the reaction kinetics of the alkali powder activated systems. A qualitative evidence of the alkali-hydroxide concentration of the paste pore solution through the use of electrical conductivity measurements is also presented, with the results indicating the ion concentration of alkali is more prevalent in the pore solution of potassium-based systems. The use of advanced spectroscopic and thermal analysis techniques to distinguish the influence of studied parameters is also discussed.
ContributorsChowdhury, Ussala (Author) / Neithalath, Narayanan (Thesis advisor) / Rajan, Subramanium D. (Committee member) / Mobasher, Barzin (Committee member) / Arizona State University (Publisher)
Created2013
Description
This dissertation integrates humanities with social science methodologies within a critical framework, seeking to explore the relationship between the neoliberal restructuring and the intersection of gender, class and heteronormativity in contemporary China. In this project, neoliberalism is conceptualized as an art of governance centering on the intersection of race, gender, class and sexuality to create market subjects and sustain market competition. Focusing on China's recent socio-economic and cultural upheavals, this dissertation tries to address these questions: 1. How have class inequalities, binaristic gender and heteronormative discourses been employed intersectionally by the Chinese state to facilitate China's social transformation? 2. How has this process been justified and consolidated through the intersection of gender, class, sexuality and race? 3. How do the marginalized groups respond to these material and cultural practices? Building on the discursive analysis of China's televised 60th anniversary ceremony and If You Are the One, a popular Chinese reality show, as well as the data from the interview, focus group and participant observation of more than 100 informants, it is found that the intersection of gender, class and heteronormativity is central to China's neoliberal transition. A group of flexible and cheap laborers have been disarticulated and rearticulated from the population as the voluntary servitude to China's marketization and re-integration with the global economy. New controlling images, such as the bourgeois nucleus family, are created to legitimize this process. However, these disparate material and discursive practices have entailed contradictions and conflicts within the intersectional biopolitical system, and created contingent spaces of ungovernability for the marginalized groups. Building on these discursive analyses and empirical data, I reconceptualize intersectionality as a multi-dimensional-and-directional network to regulate and manage power for social organization and regulation, which grounds the biopolitical basics for the neoliberal economy. Thus I argue that we need to engage with the dynamics between the intersectional biopolitical structure and people's emerging experiences to construct a grounded utopia alternative to the neoliberal dominance for substantive social changes.
ContributorsZhang, Charlie Yi (Author) / Quan, H. L. T. (Thesis advisor) / Fonow, Mary Margaret (Thesis advisor) / Martinez, Jacqueline M. (Committee member) / Lee, Charles T. (Committee member) / Arizona State University (Publisher)
Created2013
Description
The purpose of my dissertation project is to understand how Same-Gender Loving (SGL) Black Christian men negotiate their sexuality and spirituality in spaces that are not always accepting of SGL people, by examining on how Black SGL men perform their sexual identities within hegemonic institutions that often deny their existence or outwardly seek to exclude them from their communities. I have identified three scripts that Black SGL men often follow within Black religious settings. The first script that SGL people often follow in the church is that of deliverance-- confessing their same-gender desires and maintaining that they have been delivered from those desires The second is "don't ask don't tell" performed by men who many believe and suspect of being SGL; so long as they do not publicly affirm these beliefs they are able to hold a variety of positions in their religious communities.. The last script involves accepting one's same-gender desires and also affirming one's Christian beliefs, proclaiming that the two are not at odds with one another. I examine how these scripts and/or others are performed by and on the bodies of Black SGL males in two distinct sites. The first is the career and music of former gospel star Anthony Charles Williams II (Tonex / B. Slade), who has utilized the three scripts at various times in his career. The next site is that of theatre, where I explore how these scripts have been employed in dramatic texts. By reading Christian Black SGL performance through its theological parameters, I aim to discern the avenues in which Black people in the United States are able to perform same-gender sexual identities in spaces that are constructed as "homophobic," and in so doing combat the narrative of hyper-homophobia in Black communities.
ContributorsChester, Tabitha Jamie Mary (Author) / Anderson, Lisa (Thesis advisor) / Leong, Karen J (Committee member) / Honegger, Gitta (Committee member) / Arizona State University (Publisher)
Created2013
Description
This study was done in collaboration with the Kino Border Initiative. The Kino Border Initiative is a Catholic, bi-national organization run by Missionary Sisters of the Eucharist, Jesuit priests and lay people. The organization is dedicated to providing services to recently deported migrants and migrants-in-transit through their soup kitchen, women's shelter and first aid station in Nogales, Sonora. Based on their experiences in the women's shelter, the Missionary Sisters of the Eucharist and researcher sought out to further understand migrant women's experiences of gender-based violence prior to migration. Using data collected by the Sisters, it was decided to use an analysis rooted in testimonio, and, in this way, use the women's words as a foundational basis for understanding the migration of women. The analysis is based on 62 testimonies related to women's histories of violence and their migration experiences, and the information from 74 intake questionnaires that were all analyzed retroactively. The analysis of data and testimonios has led to the realization that violence suffered by migrant women is not limited to the journey itself, and that 71% of women report having suffered some sort of violence either prior to or during migration. Often times, the first experiences of violence originated in their homes when they were children and continue to repeat itself throughout their lifetimes in varied forms. Their stories reveal how the decision to migrate is a consequence to the transnational and structural violence that pushes women to seek out ways to survive and provide for their families.
ContributorsConrad, Marla (Author) / Elenes, C. Alejandra (Thesis advisor) / Simmons, William P. (Committee member) / Téllez, Michelle (Committee member) / Arizona State University (Publisher)
Created2013
Description
The thesis studies new methods to fabricate optoelectronic Ge1-ySny/Si(100) alloys and investigate their photoluminescence (PL) properties for possible applications in Si-based photonics including IR lasers. The work initially investigated the origin of the difference between the PL spectrum of bulk Ge, dominated by indirect gap emission, and the PL spectrum of Ge-on-Si films, dominated by direct gap emission. It was found that the difference is due to the supression of self-absorption effects in Ge films, combined with a deviation from quasi-equilibrium conditions in the conduction band of undoped films. The latter is confirmed by a model suggesting that the deviation is caused by the shorter recombination lifetime in the films relative to bulk Ge. The knowledge acquired from this work was then utilized to study the PL properties of n-type Ge1-ySny/Si (y=0.004-0.04) samples grown via chemical vapor deposition of Ge2H6/SnD4/P(GeH3)3. It was found that the emission intensity (I) of these samples is at least 10x stronger than observed in un-doped counterparts and that the Idir/Iind ratio of direct over indirect gap emission increases for high-Sn contents due to the reduced gamma-L valley separation, as expected. Next the PL investigation was expanded to samples with y=0.05-0.09 grown via a new method using the more reactive Ge3H8 in place of Ge2H6. Optical quality, 1-um thick Ge1-ySny/Si(100) layers were produced using Ge3H10/SnD4 and found to exhibit strong, tunable PL near the threshold of the direct-indirect bandgap crossover. A byproduct of this study was the development of an enhanced process to produce Ge3H8, Ge4H10, and Ge5H12 analogs for application in ultra-low temperature deposition of Group-IV semiconductors. The thesis also studies synthesis routes of an entirely new class of semiconductor compounds and alloys described by Si5-2y(III-V)y (III=Al, V= As, P) comprising of specifically designed diamond-like structures based on a Si parent lattice incorporating isolated III-V units. The common theme of the two thesis topics is the development of new mono-crystalline materials on ubiquitous silicon platforms with the objective of enhancing the optoelectronic performance of Si and Ge semiconductors, potentially leading to the design of next generation optical devices including lasers, detectors and solar cells.
ContributorsGrzybowski, Gordon (Author) / Kouvetakis, John (Thesis advisor) / Chizmeshya, Andrew (Committee member) / Menéndez, Jose (Committee member) / Arizona State University (Publisher)
Created2013
Description
Nitrate is the most prevalent water pollutant limiting the use of groundwater as a potable water source. The overarching goal of this dissertation was to leverage advances in nanotechnology to improve nitrate photocatalysis and transition treatment to the full-scale. The research objectives were to (1) examine commercial and synthesized photocatalysts, (2) determine the effect of water quality parameters (e.g., pH), (3) conduct responsible engineering by ensuring detection methods were in place for novel materials, and (4) develop a conceptual framework for designing nitrate-specific photocatalysts. The key issues for implementing photocatalysis for nitrate drinking water treatment were efficient nitrate removal at neutral pH and by-product selectivity toward nitrogen gases, rather than by-products that pose a human health concern (e.g., nitrite). Photocatalytic nitrate reduction was found to follow a series of proton-coupled electron transfers. The nitrate reduction rate was limited by the electron-hole recombination rate, and the addition of an electron donor (e.g., formate) was necessary to reduce the recombination rate and achieve efficient nitrate removal. Nano-sized photocatalysts with high surface areas mitigated the negative effects of competing aqueous anions. The key water quality parameter impacting by-product selectivity was pH. For pH < 4, the by-product selectivity was mostly N-gas with some NH4+, but this shifted to NO2- above pH = 4, which suggests the need for proton localization to move beyond NO2-. Co-catalysts that form a Schottky barrier, allowing for localization of electrons, were best for nitrate reduction. Silver was optimal in heterogeneous systems because of its ability to improve nitrate reduction activity and N-gas by-product selectivity, and graphene was optimal in two-electrode systems because of its ability to shuttle electrons to the working electrode. "Environmentally responsible use of nanomaterials" is to ensure that detection methods are in place for the nanomaterials tested. While methods exist for the metals and metal oxides examined, there are currently none for carbon nanotubes (CNTs) and graphene. Acknowledging that risk assessment encompasses dose-response and exposure, new analytical methods were developed for extracting and detecting CNTs and graphene in complex organic environmental (e.g., urban air) and biological matrices (e.g. rat lungs).
ContributorsDoudrick, Kyle (Author) / Westerhoff, Paul (Thesis advisor) / Halden, Rolf (Committee member) / Hristovski, Kiril (Committee member) / Arizona State University (Publisher)
Created2013