Matching Items (43,917)
Description
It is estimated that wind induced soil transports more than 500 x 106 metric tons of fugitive dust annually. Soil erosion has negative effects on human health, the productivity of farms, and the quality of surface waters. A variety of different polymer stabilizers are available on the market for fugitive dust control. Most of these polymer stabilizers are expensive synthetic polymer products. Their adverse effects and expense usually limits their use. Biopolymers provide a potential alternative to synthetic polymers. They can provide dust abatement by encapsulating soil particles and creating a binding network throughout the treated area. This research into the effectiveness of biopolymers for fugitive dust control involved three phases. Phase I included proof of concept tests. Phase II included carrying out the tests in a wind tunnel. Phase III consisted of conducting the experiments in the field. Proof of concept tests showed that biopolymers have the potential to reduce soil erosion and fugitive dust transport. Wind tunnel tests on two candidate biopolymers, xanthan and chitosan, showed that there is a proportional relationship between biopolymer application rates and threshold wind velocities. The wind tunnel tests also showed that xanthan gum is more successful in the field than chitosan. The field tests showed that xanthan gum was effective at controlling soil erosion. However, the chitosan field data was inconsistent with the xanthan data and field data on bare soil.
Contributors
Alsanad, Abdullah (Author) / Kavazanjian, Edward (Thesis advisor) / Edwards, David (Committee member) / Zapata, Claudia (Committee member) / Arizona State University (Publisher)
Created
2011
Description
In this dissertation I present data gathered from an eleven-month qualitative research study with adolescents living and working on the streets of Lima, Peru. Through the pairing of photovoice with participant observations, this work incorporates distinctive methodological and theoretical viewpoints in order to complicate prevailing understandings of street life. In this dissertation, I examine the identities that children and adolescents on the street develop in context, and the ways in which photography can be a useful tool in understanding identity development among this population. Through a framework integrating theories of identity and identity performance with spatial theories, I outline how identity development among children and adolescents living on the street is directly connected to their relationships with the urban landscape and the outreach organizations that serve them. The organizations and institutions that surround children on the street shape who they are, how they are perceived by society, and how they view and understand themselves in context. It is through the interaction with aid organizations and the urban landscape that a street identity is learned and developed. Furthermore, as organizations, children and adolescents come together within the context of the city, a unique street space is created. I argue that identity and agency are directly tied to this space. I also present the street as a thirdspace of possibility, where children and adolescents are able to act out various aspects of the self that they would be unable to pursue otherwise. Weaved throughout this dissertation are non-traditional writing forms including narrative and critical personal narrative addressing my own experiences conducting this research, my impact on the research context, and how I understand the data gathered.
Contributors
Joanou, Jamie Patrice (Author) / Swadener, Beth B. (Thesis advisor) / Margolis, Eric (Committee member) / Arzubiaga, Angela (Committee member) / Fischman, Gustavo (Committee member) / Arizona State University (Publisher)
Created
2011
Description
The Civil Rights Project estimates that Black girls are among the least likely to graduate from high school. More specifically, only about half, or 56%, of freshman Black girls graduate with their class four years later. Beyond the statistics little is known about Black girls who drop out, why they leave school and what happens to them once they are gone. This study is a grounded theory analysis of the stories eight adult Black women told about dropping out of high school with a particular focus on how dropping out affected their lives as workers, mothers and returners to education. There is one conclusion about dropping out and another about Black female identity. First, the women in my study were adolescents during the 1980s, experienced life at the intersection of Blackness, womaness, and poverty and lived in the harsh conditions of a Black American hyperghetto. Using a synthesis between intersectionality and hyperghettoization I found that the women were so determined to improve their economic and personal conditions that they took on occupations that seemed to promise freedom, wealth and safety. Because they were so focused on their new lives, their school attendance suffered as a consequence. In the second conclusion I argued that Black women draw their insights about Black female identity from two competing sources. The two sources are their lived experience and popular controlling images of Black female identity.
Contributors
Griffin, Erica Nicole (Author) / Powers, Jeanne (Thesis advisor) / Fischman, Gustavo (Committee member) / Margolis, Eric (Committee member) / Arizona State University (Publisher)
Created
2011
Description
This thesis seeks to build upon the empirical use of the Copenhagen School of security studies by evaluating and investigating speech-acts in recent Guatemalan newspaper media as they relate to drug trafficking within the geopolitical borders of Guatemala, particularly induced by Los Zetas, a Mexican drug cartel. The study attempts to engage a critical theoretical framework to study securitization within the country and thereby build upon the theory by conducting real-life analysis. Using a research program that is made up of content and text analysis of national press and presidential speeches, I test several hypotheses that pertain to the processes of Guatemala's current drug trade and drug trafficking securitization. By coding securitizing speech-acts and discursive frames in the national print media, I identify the national elite, the power relations between the national elite and citizenship, and attempts to dramatize the issue of drug trade. Upon analyzing the findings of such securitization, I propose several hypotheses as to why the national elite seeks high politicization of drug trade and the implications that rest on such drastic measures. This thesis itself, then, has important implications: it uses empirical tools to help further the theoretical foundations of the Copenhagen School, it examines the process of securitization study from a real world context outside the developed world, and it presents important information on the possible consequences of securitizing drug trade.
Contributors
Brinkmoeller, Matthew (Author) / Doty, Roxanne (Thesis advisor) / Gortzak, Yoav (Committee member) / Jones, Ruth (Committee member) / Arizona State University (Publisher)
Created
2011
Description
The name of Geechie Wiley has surfaced only rarely since 1931, when she recorded her second session with the Paramount Company in Grafton, WI. A few scholars including Paul Oliver and Greil Marcus unearthed and promoted her music and called for further research on this enigmatic figure. In other publications, Wiley is frequently given only passing mention in long lists of talented female blues singer-guitarists, or briefly discussed in descriptions of songsters. Her music is lauded in the liner notes of the myriad compilation albums that have re-released her recordings. However, prior to this study, Marcus's three-page profile is the longest work written about Wiley; other contributions range between one sentence and two paragraphs in length. None really answers the question: who was Geechie Wiley? This thesis begins by documenting my attempt to piece together all information presently available on Geechie Wiley. A biographical chapter, supplemented with a discussion of the blues songster, follows. I then discuss my methodology and philosophy for transcription. This is followed by a critical and comparative analysis of the recordings, using the transcriptions as supplements. Finally, my fifth chapter presents conclusions about Wiley's life, career, and disappearance. My transcriptions of Wiley's six songs are found in the first appendix. Reproductions of Paramount Records advertisements are located in the final appendix. In these ways, this thesis argues that Wiley's work traces the transformation of African-American music from the general secular music of the songsters to the iconic blues genre.
Contributors
Cordeiro, AnneMarie Youell (Author) / Norton, Kay (Thesis advisor) / Mook, Richard (Committee member) / Sunkett, Mark (Committee member) / Arizona State University (Publisher)
Created
2011
Description
This work investigates in-situ stress evolution of interfacial and bulk processes in electrochemical systems, and is divided into two projects. The first project examines the electrocapillarity of clean and CO-covered electrodes. It also investigates surface stress evolution during electro-oxidation of CO at Pt{111}, Ru/Pt{111} and Ru{0001} electrodes. The second project explores the evolution of bulk stress that occurs during intercalation (extraction) of lithium (Li) and formation of a solid electrolyte interphase during electrochemical reduction (oxidation) of Li at graphitic electrodes. Electrocapillarity measurements have shown that hydrogen and hydroxide adsorption are compressive on Pt{111}, Ru/Pt{111}, and Ru{0001}. The adsorption-induced surface stresses correlate strongly with adsorption charge. Electrocatalytic oxidation of CO on Pt{111} and Ru/Pt{111} gives a tensile surface stress. A numerical method was developed to separate both current and stress into background and active components. Applying this model to the CO oxidation signal on Ru{0001} gives a tensile surface stress and elucidates the rate limiting steps on all three electrodes. The enhanced catalysis of Ru/Pt{111} is confirmed to be bi-functional in nature: Ru provides adsorbed hydroxide to Pt allowing for rapid CO oxidation. The majority of Li-ion batteries have anodes consisting of graphite particles with polyvinylidene fluoride (PVDF) as binder. Intercalation of Li into graphite occurs in stages and produces anisotropic strains. As batteries have a fixed size and shape these strains are converted into mechanical stresses. Conventionally staging phenomena has been observed with X-ray diffraction and collaborated electrochemically with the potential. Work herein shows that staging is also clearly observed in stress. The Li staging potentials as measured by differential chronopotentiometry and stress are nearly identical. Relative peak heights of Li staging, as measured by these two techniques, are similar during reduction, but differ during oxidation due to non-linear stress relaxation phenomena. This stress relaxation appears to be due to homogenization of Li within graphite particles rather than viscous flow of the binder. The first Li reduction wave occurs simultaneously with formation of a passivating layer known as the solid electrolyte interphase (SEI). Preliminary experiments have shown the stress of SEI formation to be tensile (~+1.5 MPa).
Contributors
Mickelson, Lawrence (Author) / Friesen, Cody (Thesis advisor) / Sieradzki, Karl (Committee member) / Buttry, Daniel (Committee member) / Venables, John (Committee member) / Arizona State University (Publisher)
Created
2011
Description
This study investigates the impact of portfolio disclosure on hedge fund performance. Using a regression discontinuity design, I investigate the effect of the disclosure requirements that take effect when an investment company's assets exceed $100 million; when that occurs, a fund is required by the SEC to submit form 13F disclosing its portfolio holdings. Consistent with the argument that portfolio disclosure reveals "trade secrets" and also raises front running costs thus harms the funds that disclose, I find that there is a drop in fund performance (about 4% annually) after a fund begins filing form 13F, as well as an increase in return correlations with other hedge funds in the same investment style. The drop in performance cannot be explained by a change in the assets under management or a mean reversion in returns. Consistent with the idea that funds with illiquid holdings tend to employ sequential trading strategies, which increase the likelihood of being taken advantage of by free riders and front runners, the drop in performance is more dramatic for funds that have more illiquid holdings. In addition, I find that the incentive fees paid to fund managers are 1% higher when portfolio disclosure is required, which supports the hypothesis that investors' monitoring of portfolio holdings disciplines adverse risk-taking by fund managers and allows for higher convexity in the optimal compensation structure. Finally, there is a drop in flows into funds that file 13F, which suggests that hedge fund investors negatively value 13F disclosure. Overall, this study suggests that the cost of portfolio disclosure is economically large. It contributes to the policy debate over what constitutes optimal disclosure.
Contributors
Shi, Zhen (Author) / Hertzel, Michael (Thesis advisor) / Aragon, Georges (Thesis advisor) / Coles, Jeffrey (Committee member) / Arizona State University (Publisher)
Created
2011
Description
This study analyzed archaeological residential inventories from the center of Sauce and its hinterlands to address the possible appearance of markets and the structure of exchange during the Middle Postclassic period (A.D. 1200-1350) in south-central Veracruz, Mexico. Economic development is rarely the result of a coherent strategy either on the part of managing or consuming elites or on the part of the average consumer. Instead, a combination of strategies and overlapping exchange systems provided the context, rather than any one explanation, for how commercial market exchange develops. Identifying the context is challenging because economies have multiple exchange mechanisms, which require clearly defined expectations that separate spatial and network (distributional) data. This separation is vital because different exchange mechanisms such as centralized redistribution versus central-place marketing produce similar spatial patterns. Recent innovations in identifying exchange mechanisms use network (distributional) instead of spatial expectations. Based on this new body of knowledge, new quantitative methods were developed to distinguish between exchange through social networks versus market exchange for individual items based on comparisons of household inventories, later combining this information with spatial and contextual analyses. First, a Bayesian-inspired Monte Carlo computer simulation was designed to identify exchange mechanisms, using all household items including cooking utensils, serving dishes, chipped stone tools, etc., from 65 residential units from Sauce and its hinterland. Next, the socioeconomic rank of households, GIS spatial analyses, and quality assessments of pottery and other items were used to evaluate social and political aspects of exchange and consumption. The results of this study indicated that most products were unrestricted in access, and spatial analyses showed they were acquired in a market near Sauce. Few restrictions on most of the polychromes, chipped stone, and assorted household items (e.g., spindle whorls) lend strong support to commoner household prominence in developing markets. However, there were exceptions. Dull Buff Polychrome was associated with the Sauce center; analyses showed that its access was restricted through social networks. "Cookie-cutter" style figurines and incense burners also showed restriction. Restricted items found in Sauce and wealthier residences indicate enduring political and social inequalities within market development. For Sauce, a combination of elite and commoner household interests was crucial in supporting the growth of commercial exchange rather than a top-down directive.
Contributors
Ossa, Alanna (Author) / Stark, Barbara L. (Thesis advisor) / Cowgill, George L. (Committee member) / Smith, Michael E. (Committee member) / Simon, Arleyn W. (Committee member) / Umberger, Emily (Committee member) / Arizona State University (Publisher)
Created
2011
Description
In this study, I investigate the digital literacy practices of adult immigrants, and their relationship with transnational processes and practices. Specifically, I focus on their conditions of access to information and communication technologies (ICTs) in their life trajectories, their conditions of learning in a community center, and their appropriation of digital literacy practices for transnational purposes. By studying the culturally situated nature of digital literacies of adult learners with transnational affiliations, I build on recent empirical work in the fields of New Literacy Studies, sociocultural approaches to learning, and transnational studies. In this qualitative study, I utilized ethnographic techniques for data collection, including participant observation, interviewing, and collection of material and electronic artifacts. I drew from case study approaches to analyze and present the experiences of five adult first-generation immigrant participants. I also negotiated multiple positionalities during the two phases of the study: as a participant observer and instructor's aide during the Basic Computer Skills course participants attended, and as a researcher-practitioner in the Web Design course that followed. From these multiple vantage points, my analysis demonstrates that participants' access to ICTs is shaped by structural factors, family dynamics, and individuals' constructions of the value of digital literacies. These factors influence participants' conditions of access to material resources, such as computer equipment, and access to mentoring opportunities with members of their social networks. In addition, my analysis of the instructional practices in the classroom shows that instructors used multiple modalities, multiple languages and specialized discourses to scaffold participants' understandings of digital spaces and interfaces. Lastly, in my analysis of participants' repertoires of digital literacy practices, I found that their engagement in technology use for purposes of communication, learning, political participation and online publishing supported their maintenance of transnational affiliations. Conversely, participants' transnational ties and resources supported their appropriation of digital literacies in everyday practice. This study concludes with a discussion on the relationship among learning, digital literacies and transnationalism, and the contributions of critical and ethnographic perspectives to the study of programs that can bridge digital inequality for minority groups.
Contributors
Noguerón, Silvia Cecilia (Author) / Warriner, Doris S (Thesis advisor) / Faltis, Christian J (Committee member) / Mccarty, Teresa (Committee member) / Wiley, Terrence (Committee member) / Arizona State University (Publisher)
Created
2011
Description
Traumas are moments which disrupt a way of being, often involving death or injury and a period of recovery for its survivors. They can be personal, experienced by an individual, or collective, experienced by a group of individuals, such as a family. Others, like the bombing of Hiroshima, impact much larger communities, such as an entire town, an entire nation, or even the world. These national traumas often include large-scale death or injury and impact the lives of thousands. In addition to their immediate physical and material affects (mortalities, economic impact, creating a need for aid), these events shatter not only an individual's sense of well- being, but also larger notions of national identity, stability and security. In many cases, they also reveal the limits of prevailing concepts of national cohesiveness, citizenship and belonging while often simultaneously upholding or reconstructing newly problematic concepts of national cohesion. Traumas are documented and grappled with through various media, including literature, poetry, art, photography, and journalism. This dissertation, "Performing Nation, Performing Trauma: Theatre and Performance after September 11th, Hurricane Katrina and the Peruvian Dirty War" examines how theatre and performance are utilized to respond to, document, memorialize and represent national traumas resulting from such historical crises as the Peruvian Dirty Wars, Hurricane Katrina, and September 11th, as well as how they resist dominant narratives that construct national traumas as such. These traumas are relived and expressed through performance perhaps precisely because the members of a nation (consciously or subconsciously) recognize that nation is also performed. This dissertation focuses on both the content of and the reception of these performances and the particular implications that performances about national traumas hold for theatre critics/scholars, performance practitioners and audience members (those immediately connected and not so obviously connected to the event).
Contributors
Nigh, Katherine Jean (Author) / Underiner, Tamara (Thesis advisor) / Woodson, Stephani (Committee member) / Whitaker, Matthew C. (Committee member) / Arizona State University (Publisher)
Created
2011