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
Emergent environmental issues, ever-shrinking petroleum reserves, and rising fossil fuel costs continue to spur interest in the development of sustainable biofuels from renewable feed-stocks. Meanwhile, however, the development and viability of biofuel fermentations remain limited by numerous factors such as feedback inhibition and inefficient and generally energy intensive product recovery processes. To circumvent both feedback inhibition and recovery issues, researchers have turned their attention to incorporating energy efficient separation techniques such as adsorption in in situ product recovery (ISPR) approaches. This thesis focused on the characterization of two novel adsorbents for the recovery of alcohol biofuels from model aqueous solutions. First, a hydrophobic silica aerogel was evaluated as a biofuel adsorbent through characterization of equilibrium behavior for conventional second generation biofuels (e.g., ethanol and n-butanol). Longer chain and accordingly more hydrophobic alcohols (i.e., n-butanol and 2-pentanol) were more effectively adsorbed than shorter chain alcohols (i.e., ethanol and i-propanol), suggesting a mechanism of hydrophobic adsorption. Still, the adsorbed alcohol capacity at biologically relevant conditions were low relative to other `model' biofuel adsorbents as a result of poor interfacial contact between the aqueous and sorbent. However, sorbent wettability and adsorption is greatly enhanced at high concentrations of alcohol in the aqueous. Consequently, the sorbent exhibits Type IV adsorption isotherms for all biofuels studied, which results from significant multilayer adsorption at elevated alcohol concentrations in the aqueous. Additionally, sorbent wettability significantly affects the dynamic binding efficiency within a packed adsorption column. Second, mesoporous carbons were evaluated as biofuel adsorbents through characterization of equilibrium and kinetic behavior. Variations in synthetic conditions enabled tuning of specific surface area and pore morphology of adsorbents. The adsorbed alcohol capacity increased with elevated specific surface area of the adsorbents. While their adsorption capacity is comparable to polymeric adsorbents of similar surface area, pore morphology and structure of mesoporous carbons greatly influenced adsorption rates. Multiple cycles of adsorbent regeneration rendered no impact on adsorption equilibrium or kinetics. The high chemical and thermal stability of mesoporous carbons provide potential significant advantages over other commonly examined biofuel adsorbents. Correspondingly, mesoporous carbons should be further studied for biofuel ISPR applications.
ContributorsLevario, Thomas (Author) / Nielsen, David R (Thesis advisor) / Vogt, Bryan D (Committee member) / Lind, Mary L (Committee member) / Arizona State University (Publisher)
Created2011
Description
The current study explored whether intrinsically religious individuals are able to separate the "sin" from the "sinner" (i.e., separate category membership from behavior) when judging homosexual individuals, or whether they are instead subject to the negativity bias (judgments based solely on category membership) in moral judgments. All effects were expected to occur only for participants high in homophobia. Participants were 305 undergraduate male and female students at a large, public university in the southwestern U.S. Respondents read one of five scenarios that described gay or straight targets who were celibate or engaged in same or opposite sex relationships, then were asked to respond to a series of questions evaluating attitudes and behavioral intentions toward the target. Results revealed that homophobia led to a negativity bias in judgments of gay targets, which was intensified by intrinsic religiosity. However, individuals high on intrinsic religiosity and high on homophobia also differentiated between gay targets based on sexual behavior, such that gay targets who were celibate or in an opposite-sex relationship were rated more favorably than gay targets in a same-sex relationship. These findings demonstrate that the negativity bias and "sin vs. sinner" differentiation may both be occurring for intrinsically religious individuals. The moderating effect of homophobia on the interaction between intrinsic religiosity and judgments of gay and straight targets shows us that religiosity itself is not inherently tolerant or intolerant.
ContributorsFilip-Crawford, Gabrielle (Author) / Nagoshi, Craig T. (Thesis advisor) / Kwan, Virginia S.Y. (Committee member) / Neuberg, Steven L. (Committee member) / Arizona State University (Publisher)
Created2011
Description
This dissertation examines associations between religious affiliation, religious community context and health of women and their children in Mozambique focusing on the following issues: (1) attending prenatal consultations and delivering children in a health facility; (2) women's symptoms of STDs; and (3) under-five mortality. Estimation of random intercept Poisson regression for the outcome about attending prenatal consultations demonstrated a favorable effect of affiliation to Catholic or Mainline Protestant and Apostolic religious groups. The concentration of Zionist churches in the community had a negative influence. Random intercept logistic regression was used to estimate the relationship between religion and institutional child delivery. Affiliation to Catholic or Mainline Protestant denominations as well as concentration of Catholic or Mainline Protestant churches in the community had some beneficial effect on giving birth in health clinics. The presence of Zionist churches in the community had some negative effect and that of other groups no significant influence. Random intercept logistic regression was also employed for investigating the influence of religion on women's symptoms of STDs. Belonging to the Catholic or Mainline Protestant church had some protective effect on reporting symptoms of STDs. There was no effect of religious context, except that the concentration of Other Pentecostal churches had a positive effect on reporting symptoms of SDTs. Event-history analysis was conducted for examining relationships between maternal religious affiliation with under-five mortality. Affiliation to Catholic or Mainline Protestant churches and to Apostolic denominations increased the odds of child survival, although, the influence of having a mother belonging to Catholic or Mainline Protestant churches lost statistical significance after accounting particularly for the average level of education in the community, for the period of 5 years preceding the survey date. Taken together, the results in this dissertation show some protective effect of religion that varies primarily by denominational group to which women are affiliated. They also indicate that religious community context may have some negative effect on health of women and children. The nature of the effect of religious community context varies with the type of outcome considered and the type of religious mixture in the community.
ContributorsCau, Boaventura Manuel (Author) / Agadjanian, Victor (Thesis advisor) / Hayford, Sarah (Committee member) / Yabiku, Scott (Committee member) / Arizona State University (Publisher)
Created2011
Description
In the current context of fiscal austerity as well as neo-colonial criticisms, the discipline of religious studies has been challenged to critically assess its teaching methods as well as articulate its relevance in the modern university setting. Responding to these needs, this dissertation explores the educational outcomes on undergraduate students as a result of religious studies curriculum. This research employs a robust quantitative methodology designed to assess the impact of the courses while controlling for a number of covariates. Based on data collected from pre- and post-course surveys of a combined 1,116 students enrolled at Arizona State University (ASU) and two area community colleges, the research examines student change across five outcomes: attributional complexity, multi-religious awareness, commitment to social justice, individual religiosity, and the first to be developed, neo-colonial measures. The sample was taken in the Fall of 2009 from courses including Religions of the World, introductory Islamic studies courses, and a control group consisting of engineering and political science students. The findings were mixed. From the "virtues of the humanities" standpoint, select within group changes showed a statistically significant positive shift, but when compared across groups and the control group, there were no statistically significant findings after controlling for key variables. The students' pre-course survey score was the best predictor of their post-course survey score. In response to the neo-colonial critiques, the non-findings suggest the critiques have been overstated in terms of their impact pedagogically or in the classroom.
ContributorsLewis, Bret (Author) / Gereboff, Joel (Thesis advisor) / Foard, James (Committee member) / Levy, Roy (Committee member) / Woodward, Mark (Committee member) / Arizona State University (Publisher)
Created2011
Description
The Mormon Plan of Salvation explains that people originate in a heavenly state and are sent to Earth in a physical form, where they aspire to lead good lives and gain wisdom in order to reach glory in the afterlife. The dance piece "From There to Here to There: Whose Journey is it Anyway?" explores each stage in the Plan of Salvation at a different location, requiring dancers and audience to travel both metaphorically and physically. The piece incorporates several kinds of journeys: the collective journey of humankind based on the Plan of Salvation, the dancers' own journeys, and audience's journey as they watch the piece, and my journey as an artist. In the process of making this piece, I refined my identity as a 21st century Mormon artist interested in conveying religious messages through the traditionally secular art form of postmodern dance.
ContributorsFrost, Randi (Author) / Kaplan, Robert (Thesis advisor) / Daughtrey, Doe (Committee member) / Schupp, Karen (Committee member) / Arizona State University (Publisher)
Created2011
Description
Proton exchange membrane fuel cells (PEMFCs) run on pure hydrogen and oxygen (or air), producing electricity, water, and some heat. This makes PEMFC an attractive option for clean power generation. PEMFCs also operate at low temperature which makes them quick to start up and easy to handle. PEMFCs have several important limitations which must be overcome before commercial viability can be achieved. Active areas of research into making them commercially viable include reducing the cost, size and weight of fuel cells while also increasing their durability and performance. A growing and important part of this research involves the computer modeling of fuel cells. High quality computer modeling and simulation of fuel cells can help speed up the discovery of optimized fuel cell components. Computer modeling can also help improve fundamental understanding of the mechanisms and reactions that take place within the fuel cell. The work presented in this thesis describes a procedure for utilizing computer modeling to create high quality fuel cell simulations using Ansys Fluent 12.1. Methods for creating computer aided design (CAD) models of fuel cells are discussed. Detailed simulation parameters are described and emphasis is placed on establishing convergence criteria which are essential for producing consistent results. A mesh sensitivity study of the catalyst and membrane layers is presented showing the importance of adhering to strictly defined convergence criteria. A study of iteration sensitivity of the simulation at low and high current densities is performed which demonstrates the variance in the rate of convergence and the absolute difference between solution values derived at low numbers of iterations and high numbers of iterations.
ContributorsArvay, Adam (Author) / Madakannan, Arunachalanadar (Thesis advisor) / Peng, Xihong (Committee member) / Liang, Yong (Committee member) / Subach, James (Committee member) / Arizona State University (Publisher)
Created2011
Description
Infant mortality rate of field deployed photovoltaic (PV) modules may be expected to be higher than that estimated by standard qualification tests. The reason for increased failure rates may be attributed to the high system voltages. High voltages (HV) in grid connected modules induce additional stress factors that cause new degradation mechanisms. These new degradation mechanisms are not recognized by qualification stress tests. To study and model the effect of high system voltages, recently, potential induced degradation (PID) test method has been introduced. Using PID studies, it has been reported that high voltage failure rates are essentially due to increased leakage currents from active semiconducting layer to the grounded module frame, through encapsulant and/or glass. This project involved designing and commissioning of a new PID test bed at Photovoltaic Reliability Laboratory (PRL) of Arizona State University (ASU) to study the mechanisms of HV induced degradation. In this study, PID stress tests have been performed on accelerated stress modules, in addition to fresh modules of crystalline silicon technology. Accelerated stressing includes thermal cycling (TC200 cycles) and damp heat (1000 hours) tests as per IEC 61215. Failure rates in field deployed modules that are exposed to long term weather conditions are better simulated by conducting HV tests on prior accelerated stress tested modules. The PID testing was performed in 3 phases on a set of 5 mono crystalline silicon modules. In Phase-I of PID test, a positive bias of +600 V was applied, between shorted leads and frame of each module, on 3 modules with conducting carbon coating on glass superstrate. The 3 module set was comprised of: 1 fresh control, TC200 and DH1000. The PID test was conducted in an environmental chamber by stressing the modules at 85°C, for 35 hours with an intermittent evaluation for Arrhenius effects. In the Phase-II, a negative bias of -600 V was applied on a set of 3 modules in the chamber as defined above. The 3 module set in phase-II was comprised of: control module from phase-I, TC200 and DH1000. In the Phase-III, the same set of 3 modules which were used in the phase-II again subjected to +600 V bias to observe the recovery of lost power during the Phase-II. Electrical performance, infrared (IR) and electroluminescence (EL) were done prior and post PID testing. It was observed that high voltage positive bias in the first phase resulted in little
o power loss, high voltage negative bias in the second phase caused significant power loss and the high voltage positive bias in the third phase resulted in major recovery of lost power.
o power loss, high voltage negative bias in the second phase caused significant power loss and the high voltage positive bias in the third phase resulted in major recovery of lost power.
ContributorsGoranti, Sandhya (Author) / Tamizhmani, Govindasamy (Thesis advisor) / Rogers, Bradley (Committee member) / Macia, Narciso (Committee member) / Arizona State University (Publisher)
Created2011
Description
Building Applied Photovoltaics (BAPV) form an essential part of today's solar economy. This thesis is an effort to compare and understand the effect of fan cooling on the temperature of rooftop photovoltaic (PV) modules by comparing two side-by-side arrays (test array and control array) under identical ambient conditions of irradiance, air temperature, wind speed and wind direction. The lower operating temperature of PV modules due to fan operation mitigates array non uniformity and improves on performance. A crystalline silicon (c-Si) PV module has a light to electrical conversion efficiency of 14-20%. So on a cool sunny day with incident solar irradiance of 1000 W/m2, a PV module with 15% efficiency, will produce about only 150 watts. The rest of the energy is primarily lost in the form of heat. Heat extraction methods for BAPV systems may become increasingly higher in demand as the hot stagnant air underneath the array can be extracted to improve the array efficiency and the extracted low-temperature heat can also be used for residential space heating and water heating. Poly c-Si modules experience a negative temperature coefficient of power at about -0.5% /o C. A typical poly c-Si module would experience power loss due to elevation in temperature, which may be in the range of 25 to 30% for desert conditions such as that of Mesa, Arizona. This thesis investigates the effect of fan cooling on the previously developed thermal models at Arizona State University and on the performance of PV modules/arrays. Ambient conditions are continuously monitored and collected to calculate module temperature using the thermal model and to compare with actually measured temperature of individual modules. Including baseline analysis, the thesis has also looked into the effect of fan on the test array in three stages of 14 continuous days each. Multiple Thermal models are developed in order to identify the effect of fan cooling on performance and temperature uniformity. Although the fan did not prove to have much significant cooling effect on the system, but when combined with wind blocks it helped improve the thermal mismatch both under low and high wind speed conditions.
ContributorsChatterjee, Saurabh (Author) / Tamizhmani, Govindasamy (Thesis advisor) / Rogers, Bradley (Committee member) / Macia, Narciso (Committee member) / Arizona State University (Publisher)
Created2011
Description
Photovoltaic (PV) modules undergo performance degradation depending on climatic conditions, applications, and system configurations. The performance degradation prediction of PV modules is primarily based on Accelerated Life Testing (ALT) procedures. In order to further strengthen the ALT process, additional investigation of the power degradation of field aged PV modules in various configurations is required. A detailed investigation of 1,900 field aged (12-18 years) PV modules deployed in a power plant application was conducted for this study. Analysis was based on the current-voltage (I-V) measurement of all the 1,900 modules individually. I-V curve data of individual modules formed the basis for calculating the performance degradation of the modules. The percentage performance degradation and rates of degradation were compared to an earlier study done at the same plant. The current research was primarily focused on identifying the extent of potential induced degradation (PID) of individual modules with reference to the negative ground potential. To investigate this, the arrangement and connection of the individual modules/strings was examined in detail. The study also examined the extent of underperformance of every series string due to performance mismatch of individual modules in that string. The power loss due to individual module degradation and module mismatch at string level was then compared to the rated value.
ContributorsJaspreet Singh (Author) / Tamizhmani, Govindasamy (Thesis advisor) / Srinivasan, Devarajan (Committee member) / Rogers, Bradley (Committee member) / Arizona State University (Publisher)
Created2011
Description
Many of the works of Dominick Argento have been researched and analyzed, but his choral work Evensong: Of Love and Angels s has received limited attention thus far. Written in memoriam for his wife Carolyn Bailey Argento, Evensong draws its musical material from her initials C.B.A. These letters, translated into note names, form a conspicuous head motive that is present in each movement of the work, and it serves multiple functions: as a melodic feature, as the foundation for a twelve-tone row, and as a harmonic base. This paper provides an overview of the work's conception with specific relation to Argento's biographical details, compositional style, and work habits; a brief review of the critical reception of the work; and a succinct analysis of the form and cyclical materials found in each movement.
ContributorsPage, Carrie Leigh, 1980- (Author) / Rogers, Rodney (Thesis advisor) / DeMars, James (Committee member) / Levy, Benjamin (Committee member) / Oldani, Robert (Committee member) / Arizona State University (Publisher)
Created2011