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- Genre: Masters Thesis
- Creators: Arizona State University
- Creators: Chakraborty, Bijeta
- Member of: ASU Electronic Theses and Dissertations
Description
Water is the defining issue in determining the development and growth of human populations of the Southwest. The cities of Las Vegas, Phoenix, Tucson, Albuquerque, and El Paso have experienced rapid and exponential growth over the past 50 years. The outlook for having access to sustainable sources of water to support this growth is not promising due to water demand and supply deficits. Regional water projects have harnessed the Colorado and Rio Grande rivers to maximize the utility of the water for human consumption and environmental laws have been adopted to regulate the beneficial use of this water, but it still is not enough to create sustainable future for rapidly growing southwest cities. Future growth in these cities will depend on finding new sources of water and creative measures to maximize the utility of existing water resources. The challenge for southwest cities is to establish policies, procedures, and projects that maximizes the use of water and promotes conservation from all areas of municipal users. All cities are faced with the same challenges, but have different options for how they prioritize their water resources. The principal means of sustainable water management include recovery, recharge, reuse, and increasing the efficiency of water delivery. Other strategies that have been adopted include harvesting of rainwater, building codes that promote efficient water use, tiered water rates, turf removal programs, residential water auditing, and native plant promotion. Creating a sustainable future for the southwest will best be achieved by cities that adopt an integrated approach to managing their water resources including discouraging discretionary uses of water, adoption of building and construction codes for master plans, industrial plants, and residential construction. Additionally, a robust plan for education of the public is essential to create a culture of conservation from a very young age.
ContributorsMalloy, Richard (Richard A.) (Author) / Brock, John (Thesis advisor) / Martin, Chris (Thesis advisor) / Thor, Eric (Committee member) / Arizona State University (Publisher)
Created2013
Description
Efficiency of components is an ever increasing area of importance to portable applications, where a finite battery means finite operating time. Higher efficiency devices need to be designed that don't compromise on the performance that the consumer has come to expect. Class D amplifiers deliver on the goal of increased efficiency, but at the cost of distortion. Class AB amplifiers have low efficiency, but high linearity. By modulating the supply voltage of a Class AB amplifier to make a Class H amplifier, the efficiency can increase while still maintaining the Class AB level of linearity. A 92dB Power Supply Rejection Ratio (PSRR) Class AB amplifier and a Class H amplifier were designed in a 0.24um process for portable audio applications. Using a multiphase buck converter increased the efficiency of the Class H amplifier while still maintaining a fast response time to respond to audio frequencies. The Class H amplifier had an efficiency above the Class AB amplifier by 5-7% from 5-30mW of output power without affecting the total harmonic distortion (THD) at the design specifications. The Class H amplifier design met all design specifications and showed performance comparable to the designed Class AB amplifier across 1kHz-20kHz and 0.01mW-30mW. The Class H design was able to output 30mW into 16Ohms without any increase in THD. This design shows that Class H amplifiers merit more research into their potential for increasing efficiency of audio amplifiers and that even simple designs can give significant increases in efficiency without compromising linearity.
ContributorsPeterson, Cory (Author) / Bakkaloglu, Bertan (Thesis advisor) / Barnaby, Hugh (Committee member) / Kiaei, Sayfe (Committee member) / Arizona State University (Publisher)
Created2013
Evaluation of sustainability in development projects utilizing renewable energy products in Zimbabwe
Description
The problem concerning the access to energy has become an increasingly acute matter of concern in low-income areas. Currently an estimated 1.2 billion people don't have access to energy (IEA, 2014). Following the declaration of 2012 as "The International Year of Sustainable Energy for All" by the United Nations General Assembly (UNDP, 2014), this alarming situation of energy poverty has resulted in the creation of new partnerships between governments, NGOs (Non-Governmental Organization), and large multi-national corporations.
This study is focused on the evaluation of sustainability of a development project in Gutu, Zimbabwe that is initiated by Schneider Electric Corporation's BipBop Program. This program aims to provide access to energy via photo-voltaic cells and battery kits for daily use. It is expected that this project will have a high impact on sustainable development, and creation of value, which in turn is expected to allow participation in global supply chains.
The results gathered from the analysis show that the development project to be piloted in Gutu, Zimbabwe is likely to have a "high impact on sustainability". The project is therefore considered an effective sustainable development project that aims to promote, and develop local Zimbabwean markets through increased transactions and the creation of sustainable supply chains that are expected to recruit Zimbabwe into the global value chains.
This study is focused on the evaluation of sustainability of a development project in Gutu, Zimbabwe that is initiated by Schneider Electric Corporation's BipBop Program. This program aims to provide access to energy via photo-voltaic cells and battery kits for daily use. It is expected that this project will have a high impact on sustainable development, and creation of value, which in turn is expected to allow participation in global supply chains.
The results gathered from the analysis show that the development project to be piloted in Gutu, Zimbabwe is likely to have a "high impact on sustainability". The project is therefore considered an effective sustainable development project that aims to promote, and develop local Zimbabwean markets through increased transactions and the creation of sustainable supply chains that are expected to recruit Zimbabwe into the global value chains.
ContributorsDemirciler, Barlas (Author) / Parmentier, Mary Jane (Thesis advisor) / Grossman, Gary (Committee member) / Maltz, Arnold (Committee member) / Arizona State University (Publisher)
Created2014
Description
The current study sought to reevaluate Cass' Theory of sexual identity formation in terms of lesbian identity development over the past twenty years and how media acts as mediation in lesbian identity development. Ten semi-structured interviews were conducted with only nine useable transcripts analyzed for this thesis. This study is an explanatory investigation into linear stage theory, specifically Cass' theory, as well as the impact of media as a mediator during lesbian identity development. This study had three objectives 1) to gain an understanding of the theory and its components related to lesbian identity development 2) to understand the lesbian identity formation process and 3) to understand the impact and influence if any, media has had on lesbian self-reported identity development. Qualitative methods were used to obtain information and analyze the responses. Results indicate that the participants in this study believed that the coming out process was important. This study's results showed that several of the participants entered each stage of the theory, while others did not. Media had little influence on the identity development, and the participants had mixed reviews of medias portrayal of lesbians. Implications for practice and further research are discussed.
ContributorsHaseley, Hilary (Author) / Lacasse, Jeffrey R (Thesis advisor) / Segal, Elizabeth (Committee member) / Rounds, Tamara (Committee member) / Arizona State University (Publisher)
Created2011
Description
Despite a wealth of academic literature critiquing current tensions within the Fair Trade (FT) movement, very little work has focused on examining the birth and evolution of the FT movement within the broader context of the international political economy (IPE), specifically in reference to the ideological and policy changes that ushered in an era of free trade and deregulated markets for both trade and finance. From such an optic, it is no longer enough to merely question the extent to which the market should be engaged. Rather, one must question whether the engagement of the market strips the movement of its power to affect long term development in local economies. Drawing upon the historical record, this thesis focuses attention on the complexity of the linkages that exist between political ideology, trade policy, and development. While Fair Trade is commonly understood to be a responsive effort to create more equitable trade relations with producers in the least developed countries, less emphasis is placed on understanding the state-centered political structures that contributed to a capitalist push-back and the implementation of today's liberalized trade policy, and yet to do so is absolutely critical if we are to gain a deeper understanding of the limits and constraints of Fair Trade. Full engagement with mainstream markets has led to robust growth in the FT market per annum, yet countries that are heavily engaged with the FT market show little evidence of development or poverty reduction at a macro-level. Thus, Fair Trade must define itself as more than principled opposition to labor exploitation if it is to present itself as a credible instrument of economic development.
ContributorsSugata, Michihiro (Author) / Simmons, William (Thesis advisor) / Stancliff, Michael (Committee member) / Haglund, LaDawn (Committee member) / Arizona State University (Publisher)
Created2011
Description
Class D Amplifiers are widely used in portable systems such as mobile phones to achieve high efficiency. The demands of portable electronics for low power consumption to extend battery life and reduce heat dissipation mandate efficient, high-performance audio amplifiers. The high efficiency of Class D amplifiers (CDAs) makes them particularly attractive for portable applications. The Digital class D amplifier is an interesting solution to increase the efficiency of embedded systems. However, this solution is not good enough in terms of PWM stage linearity and power supply rejection. An efficient control is needed to correct the error sources in order to get a high fidelity sound quality in the whole audio range of frequencies. A fundamental analysis on various error sources due to non idealities in the power stage have been discussed here with key focus on Power supply perturbations driving the Power stage of a Class D Audio Amplifier. Two types of closed loop Digital Class D architecture for PSRR improvement have been proposed and modeled. Double sided uniform sampling modulation has been used. One of the architecture uses feedback around the power stage and the second architecture uses feedback into digital domain. Simulation & experimental results confirm that the closed loop PSRR & PS-IMD improve by around 30-40 dB and 25 dB respectively.
ContributorsChakraborty, Bijeta (Author) / Bakkaloglu, Bertan (Thesis advisor) / Garrity, Douglas (Committee member) / Ozev, Sule (Committee member) / Arizona State University (Publisher)
Created2012
Description
Development throughout the course of history has traditionally resulted in the demise of biodiversity. As humans strive to develop their daily livelihoods, it is often at the expense of nearby wildlife and the environment. Conservation non-governmental organizations (NGOs), among other actors in the global agenda, have blossomed in the past century with the realization that there is an immediate need for conservation action. Unlike government agencies, conservation NGOs have an independent, potentially more objective outlook on procedures and policies that would benefit certain regions or certain species the most. They often have national and international government support, in addition to the credibility and influencing power to sway policy decisions and participate in international agendas. The key to their success lies in the ability to balance conservation efforts with socioeconomic development efforts. One cannot occur without the other, but they must work in coordination. This study looks at the example of African Great Apes. Eight ape-focused NGOs and three unique case studies will be examined in order to describe the impact that NGOs have. Most of these NGOs have been able to build the capacity from an initial conservation agenda, to incorporating socioeconomic factors that benefit the development of local communities in addition to the apes and habitat they set out to influence. This being the case, initiatives by conservation NGOs could be the key to a sustainable future in which humans and biodiversity coexist harmoniously.
ContributorsPrickett, Laura (Author) / Parmentier, Mary Jane (Thesis advisor) / Zachary, Gregg (Committee member) / Gerber, Leah (Committee member) / Arizona State University (Publisher)
Created2019
Description
Online language learning is becoming increasingly popular with advances in technology that facilitate the acquisition of language in virtual environments (Duensing et al., 2006). Much of the recent literature on online foreign language instruction has focused on the possibilities presented by online technologies but has failed to examine the practical side of how and by whom online language courses are delivered. Several authors have published articles on the skills needed to be a successful online language teacher using empirical approaches (Comas-Quinn, 2011; Ernest et al., 2013; Shelly et al., 2006) and some focus more on the theoretical discussions (Compton, 2009; Hampel & Stickler, 2005). The current study drew on the existing frameworks in the previous literature to operationalize and measure the participants’ online language teaching skills while they taught a class online. These participants were graduate student instructors of Spanish at a large public university (n = 3). Using a case study approach to data analysis (Duff, 2008), and gathering data through a background questionnaire, pre-and post assessments, bi-monthly teaching journals, self- and researcher observations, an exit survey and a semi-structured post-interview, this study investigated how the participants online language teaching skills, proposed by Hampel and Stickler (2005) and Compton (2009), changed over the course of them teaching an online language course and the factors that seemed to influence more or less development in each skill area. Additionally, it compares the main findings from this study with those found in previous literature and offers recommendations of how to promote the development and sustainability of these online language teachers’ skills. This study serves as one of the few empirical studies conducted in the United States that concretely operationalizes and measures through carefully designed instruments the prescribed online language teaching skills in an effort to gain insights into what contributes to their development and how to sustain their continued growth.
ContributorsBerber-McNeill, Rebecca Sue Epps (Author) / Lafford, Barbara A. (Thesis advisor) / Ghanem, Carla (Committee member) / González López, Verónica (Committee member) / Arizona State University (Publisher)
Created2015
Description
In this thesis, a digital input class D audio amplifier system which has the ability
to reject the power supply noise and nonlinearly of the output stage is presented. The main digital class D feed-forward path is using the fully-digital sigma-delta PWM open loop topology. Feedback loop is used to suppress the power supply noise and harmonic distortions. The design is using global foundry 0.18um technology.
Based on simulation, the power supply rejection at 200Hz is about -49dB with
81dB dynamic range and -70dB THD+N. The full scale output power can reach as high as 27mW and still keep minimum -68dB THD+N. The system efficiency at full scale is about 82%.
to reject the power supply noise and nonlinearly of the output stage is presented. The main digital class D feed-forward path is using the fully-digital sigma-delta PWM open loop topology. Feedback loop is used to suppress the power supply noise and harmonic distortions. The design is using global foundry 0.18um technology.
Based on simulation, the power supply rejection at 200Hz is about -49dB with
81dB dynamic range and -70dB THD+N. The full scale output power can reach as high as 27mW and still keep minimum -68dB THD+N. The system efficiency at full scale is about 82%.
ContributorsBai, Jing (Author) / Bakkaloglu, Bertan (Thesis advisor) / Arizona State University (Publisher)
Created2015
Description
The present study aimed to test the effect of role socialization processes on declines in drinking after marriage. Role socialization as it relates to marriage theorizes that after occupying a role, individuals are likely to change their behaviors to conform to role expectations of marriage, such as reductions in drinking (Yamaguchi & Kandel, 1985). Previous literature has examined declines in drinking behaviors after marriage and inferred that role socialization was the underlying process. This study is the first to directly test whether beliefs that alcohol is harmful to the marital role predicted declines in frequency of drunkenness after marriage. Ordered probit regression was used to test the effect of marriage-related motives to limit drinking on declines in frequency of drunkenness from before marriage to after marriage. Analyses revealed that marriage-related motives to limit drinking were not significantly predictive of declines in frequency of drunkenness after marriage. Only partner drinking emerged as a significant predictor of declines in frequency of drunkenness after marriage. These results highlight the need for a reliable and valid measure of role socialization processes as they relate to the marital role. Furthermore, future studies should consider studying participants at different time points after marriage and consider measuring commitment to the marital role as a moderator. Such studies will help to better understand the results of this study as well as better understand the marriage effect on drinking.
ContributorsSternberg, Ariel (Author) / Chassin, Laurie (Thesis advisor) / Grimm, Kevin (Committee member) / Corbin, Will (Committee member) / Arizona State University (Publisher)
Created2016