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: Alford, Terry
- Creators: Gelderen, Elly van
- Creators: Zhang, Yanchao
Description
Emission of CO2 into the atmosphere has become an increasingly concerning issue as we progress into the 21st century Flue gas from coal-burning power plants accounts for 40% of all carbon dioxide emissions. The key to successful separation and sequestration is to separate CO2 directly from flue gas (10-15% CO2, 70% N2), which can range from a few hundred to as high as 1000°C. Conventional microporous membranes (carbons/silicas/zeolites) are capable of separating CO2 from N2 at low temperatures, but cannot achieve separation above 200°C. To overcome the limitations of microporous membranes, a novel ceramic-carbonate dual-phase membrane for high temperature CO2 separation was proposed. The membrane was synthesized from porous La0.6Sr0.4Co0.8Fe0.2O3-d (LSCF) supports and infiltrated with molten carbonate (Li2CO3/Na2CO3/K2CO3). The CO2 permeation mechanism involves a reaction between CO2 (gas phase) and O= (solid phase) to form CO3=, which is then transported through the molten carbonate (liquid phase) to achieve separation. The effects of membrane thickness, temperature and CO2 partial pressure were studied. Decreasing thickness from 3.0 to 0.375 mm led to higher fluxes at 900°C, ranging from 0.186 to 0.322 mL.min-1.cm-2 respectively. CO2 flux increased with temperature from 700 to 900°C. Activation energy for permeation was similar to that for oxygen ion conduction in LSCF. For partial pressures above 0.05 atm, the membrane exhibited a nearly constant flux. From these observations, it was determined that oxygen ion conductivity limits CO2 permeation and that the equilibrium oxygen vacancy concentration in LSCF is dependent on the partial pressure of CO2 in the gas phase. Finally, the dual-phase membrane was used as a membrane reactor. Separation at high temperatures can produce warm, highly concentrated streams of CO2 that could be used as a chemical feedstock for the synthesis of syngas (H2 + CO). Towards this, three different membrane reactor configurations were examined: 1) blank system, 2) LSCF catalyst and 3) 10% Ni/y-alumina catalyst. Performance increased in the order of blank system < LSCF catalyst < Ni/y-alumina catalyst. Favorable conditions for syngas production were high temperature (850°C), low sweep gas flow rate (10 mL.min-1) and high methane concentration (50%) using the Ni/y-alumina catalyst.
ContributorsAnderson, Matthew Brandon (Author) / Lin, Jerry (Thesis advisor) / Alford, Terry (Committee member) / Rege, Kaushal (Committee member) / Anderson, James (Committee member) / Rivera, Daniel (Committee member) / Arizona State University (Publisher)
Created2011
Description
The historical study of sentence adverbs has, before now, been based mostly on models that emphasize the pragmatic and discourse-based motivations of processes of grammaticalization. This dissertation breaks from such tradition by exploring diachronic adverb development through syntactic and morphological lenses. A generative, feature-based approach is used that incorporates the cartographic architecture developed by Cinque and combines it with a more phenomenological approach to both grammaticalization and lexicalization. Cinque's hierarchy of speech-act, evaluative, evidential, and epistemic adverbs is analyzed. It is determined (through corpus data) that these subcategories have grown in use primarily during the Modern English era, and particularly during the nineteenth and twentieth centuries. These four subcategories can be divided into two groups that are more general: speech-act adverbs, which arise from a (conditional) speech-act clause that undergoes ellipsis, and the other three types, which all arise from copula clauses. Each of these two groups is considered, and different methods of reanalysis by speakers are proposed for each. In addition, a revised model for categorizing adverbs is proposed. This model is based on morphological lexicalization (or univerbation) processes, thus accounting for the wide variety of adverbial source materials. Such lexicalization offers a pattern for sentence adverbial formation. Finally, Standard Chinese adverbials are briefly examined, with results indicating that they show very similar signs of lexicalization (within the limits of the writing system).
ContributorsBerry, James Andrew (Author) / Gelderen, Elly van (Thesis advisor) / Adams, Karen (Committee member) / Mailhammer, Robert (Committee member) / Arizona State University (Publisher)
Created2011
Description
ABSTRACT For this study, I chose to look at the influence that linguistics has on the publishing industry, both in writing and editing literary fiction. Both sides of publishing deal with the words and language of a novel, which is what the study of linguistics entails. Throughout this study, I researched the different areas of the publishing industry, academic programs that focus on publishing, and how-to guides on writing literary fiction in order to find out to what extent--if any--linguistics is involved. Also, through editors that I have worked with, and recommendations from various acquaintances, I interviewed two authors--one published and one unpublished--to see if they used any aspects of linguistics in their writing techniques. I found that linguistics was never specifically mentioned in the descriptions of publishing courses, in the how-to guides, nor in the answers from the authors on different writing techniques used; however, linguistics may be used or studied unintentionally.
ContributorsMoeser, Amy (Author) / Gelderen, Elly van (Thesis advisor) / Major, Roy (Committee member) / Szuter, Christine (Committee member) / Arizona State University (Publisher)
Created2011
Description
Thin films of ever reducing thickness are used in a plethora of applications and their performance is highly dependent on their microstructure. Computer simulations could then play a vital role in predicting the microstructure of thin films as a function of processing conditions. FACET is one such software tool designed by our research group to model polycrystalline thin film growth, including texture evolution and grain growth of polycrystalline films in 2D. Several modifications to the original FACET code were done to enhance its usability and accuracy. Simulations of sputtered silver thin films are presented here with FACET 2.0 with qualitative and semi-quantitative comparisons with previously published experimental results. Comparisons of grain size, texture and film thickness between simulations and experiments are presented which describe growth modes due to various deposition factors like flux angle and substrate temperature. These simulations provide reasonable agreement with the experimental data over a diverse range of process parameters. Preliminary experiments in depositions of Silver films are also attempted with varying substrates and thickness in order to generate complementary experimental and simulation studies of microstructure evolution. Overall, based on the comparisons, FACET provides interesting insights into thin film growth processes, and the effects of various deposition conditions on thin film structure and microstructure. Lastly, simple molecular dynamics simulations of deposition on bi-crystals are attempted for gaining insight into texture based grain competition during film growth. These simulations predict texture based grain coarsening mechanisms like twinning and grain boundary migration that have been commonly reported in FCC films.
ContributorsRairkar, Asit (Author) / Adams, James B (Thesis advisor) / Krause, Stephen (Committee member) / Alford, Terry (Committee member) / Arizona State University (Publisher)
Created2011
Description
The speech of non-native (L2) speakers of a language contains phonological rules that differentiate them from native speakers. These phonological rules characterize or distinguish accents in an L2. The Shibboleth program creates combinatorial rule-sets to describe the phonological pattern of these accents and classifies L2 speakers into their native language. The training and classification is done in Shibboleth by support vector machines using a Gaussian radial basis kernel. In one experiment run using Shibboleth, the program correctly identified the native language (L1) of a speaker of unknown origin 42% of the time when there were six possible L1s in which to classify the speaker. This rate is significantly better than the 17% chance classification rate. Chi-squared test (1, N=24) =10.800, p=.0010 In a second experiment, Shibboleth was not able to determine the native language family of a speaker of unknown origin at a rate better than chance (33-44%) when the L1 was not in the transcripts used for training the language family rule-set. Chi-squared test (1, N=18) =1.000, p=.3173 The 318 participants for both experiments were from the Speech Accent Archive (Weinberger, 2013), and ranged in age from 17 to 80 years old. Forty percent of the speakers were female and 60% were male. The factor that most influenced correct classification was higher age of onset for the L2. A higher number of years spent living in an English-speaking country did not have the expected positive effect on classification.
ContributorsFrost, Wende (Author) / Gelderen, Elly van (Thesis advisor) / Perzanowski, Dennis (Committee member) / Gee, Elisabeth (Committee member) / Arizona State University (Publisher)
Created2013
Description
The cyber-physical systems (CPS) are emerging as the underpinning technology for major industries in the 21-th century. This dissertation is focused on two fundamental issues in cyber-physical systems: network interdependence and information dynamics. It consists of the following two main thrusts. The first thrust is targeted at understanding the impact of network interdependence. It is shown that a cyber-physical system built upon multiple interdependent networks are more vulnerable to attacks since node failures in one network may result in failures in the other network, causing a cascade of failures that would potentially lead to the collapse of the entire infrastructure. There is thus a need to develop a new network science for modeling and quantifying cascading failures in multiple interdependent networks, and to develop network management algorithms that improve network robustness and ensure overall network reliability against cascading failures. To enhance the system robustness, a "regular" allocation strategy is proposed that yields better resistance against cascading failures compared to all possible existing strategies. Furthermore, in view of the load redistribution feature in many physical infrastructure networks, e.g., power grids, a CPS model is developed where the threshold model and the giant connected component model are used to capture the node failures in the physical infrastructure network and the cyber network, respectively. The second thrust is centered around the information dynamics in the CPS. One speculation is that the interconnections over multiple networks can facilitate information diffusion since information propagation in one network can trigger further spread in the other network. With this insight, a theoretical framework is developed to analyze information epidemic across multiple interconnecting networks. It is shown that the conjoining among networks can dramatically speed up message diffusion. Along a different avenue, many cyber-physical systems rely on wireless networks which offer platforms for information exchanges. To optimize the QoS of wireless networks, there is a need to develop a high-throughput and low-complexity scheduling algorithm to control link dynamics. To that end, distributed link scheduling algorithms are explored for multi-hop MIMO networks and two CSMA algorithms under the continuous-time model and the discrete-time model are devised, respectively.
ContributorsQian, Dajun (Author) / Zhang, Junshan (Thesis advisor) / Ying, Lei (Committee member) / Zhang, Yanchao (Committee member) / Cochran, Douglas (Committee member) / Arizona State University (Publisher)
Created2012
Description
This thesis explores the distribution of certain lexical items in Modern Standard Arabic (MSA) and their relationship with two linguistic phenomena, negative concord (NC) and negative polarity items (NPIs). The present study examines two central questions: the first question investigates whether or not MSA shows the patterns of negative concord languages. The second question concerns the distribution of N-words and NPIs in MSA, and in which environments they appear. To answer the research questions, the thesis uses the framework of generative grammar of Chomsky (1995) and The (Non)veridicality Approach by Giannakidou (1998, 2000, 2002). The data reveal that MSA shows the patterns of strict negative concord languages that are suggested by Giannakidou (2000) in the sense that the negative particle obligatorily co-occurs with the N-words which strengthen the degree of negation, and never lead to a double negation interpretation. Moreover, the data show that there is only one pure NPI which appears optionally in two environments, antiveridical and nonveridical environments, and it is disallowed in veridical environments. On the other hand, the investigated indefinite nouns show a mixed picture since they work differently from their counterparts in Arabic dialects. Their descendants in Arabic dialects appear as NPIs while they tend to be indefinite nouns rather than NPIs in MSA.
ContributorsAlanazi, Muqbil (Author) / Gelderen, Elly van (Thesis advisor) / Gillon, Carrie (Committee member) / Major, Roy (Committee member) / Arizona State University (Publisher)
Created2013
Description
Carrier lifetime is one of the few parameters which can give information about the low defect densities in today's semiconductors. In principle there is no lower limit to the defect density determined by lifetime measurements. No other technique can easily detect defect densities as low as 10-9 - 10-10 cm-3 in a simple, contactless room temperature measurement. However in practice, recombination lifetime τr measurements such as photoconductance decay (PCD) and surface photovoltage (SPV) that are widely used for characterization of bulk wafers face serious limitations when applied to thin epitaxial layers, where the layer thickness is smaller than the minority carrier diffusion length Ln. Other methods such as microwave photoconductance decay (µ-PCD), photoluminescence (PL), and frequency-dependent SPV, where the generated excess carriers are confined to the epitaxial layer width by using short excitation wavelengths, require complicated configuration and extensive surface passivation processes that make them time-consuming and not suitable for process screening purposes. Generation lifetime τg, typically measured with pulsed MOS capacitors (MOS-C) as test structures, has been shown to be an eminently suitable technique for characterization of thin epitaxial layers. It is for these reasons that the IC community, largely concerned with unipolar MOS devices, uses lifetime measurements as a "process cleanliness monitor." However when dealing with ultraclean epitaxial wafers, the classic MOS-C technique measures an effective generation lifetime τg eff which is dominated by the surface generation and hence cannot be used for screening impurity densities. I have developed a modified pulsed MOS technique for measuring generation lifetime in ultraclean thin p/p+ epitaxial layers which can be used to detect metallic impurities with densities as low as 10-10 cm-3. The widely used classic version has been shown to be unable to effectively detect such low impurity densities due to the domination of surface generation; whereas, the modified version can be used suitably as a metallic impurity density monitoring tool for such cases.
ContributorsElhami Khorasani, Arash (Author) / Alford, Terry (Thesis advisor) / Goryll, Michael (Committee member) / Bertoni, Mariana (Committee member) / Arizona State University (Publisher)
Created2013
Description
Linguistic subjectivity and subjectification are fields of research that are relatively new to those working in English linguistics. After a discussion of linguistic subjectivity and subjectification as they relate to English, I investigate the subjectification of a specific English adjective, and how its usage has changed over time. Subjectivity is held by many linguists of today to be the major governing factor behind the ordering of English prenominal adjectives. Through the use of a questionnaire, I investigate the effect of subjectivity on English prenominal adjective order from the perspective of the native English speaker. I then discuss the results of the questionnaire, what they mean in relation to how subjectivity affects that order, and a few of the patterns that emerged as I analyzed the data.
ContributorsSkarstedt, Luke (Author) / Gelderen, Elly van (Thesis advisor) / Bjork, Robert (Committee member) / Adams, Karen (Committee member) / Arizona State University (Publisher)
Created2013
Description
This thesis investigates the pronominal system in Standard Arabic. It seeks to unravel the correlation between independent and dependent personal pronouns. Although both pronoun groups are treated as distinct parts of the lexicon, I argue that dependent pronouns are reduced forms derived from the strong counterparts. This study examines how these forms (reduced and non-reduced) relate to one another phonologically and syntactically. Various analytical tools are utilized including vowel harmony, syllable structure as well as some principles of Distributed Morphology and Chomsky's 1995 Minimalist Program. With regard to the phonological relations, I argue that dependent subject pronouns are generated from their parallel strong forms by omitting the initial syllable. Dependent object pronouns are formed by omitting the first two syllables. The first person singular and third person plural masculine subject pronouns are suppletive forms completing the paradigm. They are not derived by reduction from their full counterparts. After investigating the distributional properties of both sets of pronouns, I propose a bipartite subcategorization of reduced pronominals into two subclasses: clitics and affixes. Clitics surface in positions in which strong pronouns cannot occur. As for affixes, they are used to mark verb-argument agreement. In light of these positions, I argue that dependent subject pronouns are always affixes while dependent object pronouns are always clitics. Clitics function as syntactically independent units which combine with hosts at the phonological phase as a result of their prosodic deficiency while affixes associate with hosts when features are valued during a sentence derivation.
ContributorsAlbuhayri, Salem (Author) / Gelderen, Elly van (Thesis advisor) / Adams, Karen (Committee member) / Major, Roy (Committee member) / Arizona State University (Publisher)
Created2013