Matching Items (6)
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- All Subjects: Agriculture
- All Subjects: Dissertations, Academic
- Creators: Henderson, Mark
Description
Haiti has witnessed high deforestation rates in recent decades, caused largely by the fuel needs of a growing population. The resulting soil loss is estimated to have contributed towards a decline in agricultural productivity of 0.5% -1.2% per year since 1997. Recent studies show the potential of biochar use through pyrolysis technology to increase crop yields and improve soil health. However, the appropriateness of this technology in the context of Haiti remains unexplored. The three objectives of this research were to identify agricultural- and fuel-use-related needs and gaps in rural Haitian communities; determine the appropriateness of biochar pyrolyzer technology, used to convert agricultural biomass into a carbon-rich charcoal; and develop an action-oriented plan for use by development organizations, communities, and governmental institutions to increase the likelihood of adoption. Data were collected using participatory rural appraisal techniques involving 30 individual interviews and three focus-group discussions in the villages of Cinquantin and La Boule in the La Coupe region of central Haiti. Topics discussed include agricultural practices and assets, fuel use and needs, technology use and adoption, and social management practices. The Sustainable Livelihoods framework was used to examine the assets of households and the livelihood strategies being employed. Individual and focus group interviews were analyzed to identify specific needs and gaps. E.M. Rogers' Diffusion of Innovations theory was used to develop potential strategies for the introduction of pyrolysis technology. Preliminary results indicate biochar pyrolysis has potential to address agricultural and fuel needs in rural Haiti. Probable early adopters of biochar technology include households that have adopted new agricultural techniques in the past, and those with livestock. Education about biochar, and a variety of pyrolysis technology options from which villagers may select, are important factors in successful adoption of biochar use. A grain mill as an example in one of the study villages provides a model of ownership and use of pyrolysis technology that may increase its likelihood of successful adoption. Additionally, women represent a group that may be well suited to control a new local biochar enterprise, potentially benefiting the community.
ContributorsDelaney, Michael Ryan (Author) / Aggarwal, Rimjhim (Thesis advisor) / Chhetri, Nalini (Committee member) / Henderson, Mark (Committee member) / Arizona State University (Publisher)
Created2011
Description
The current research examines the influence of disciplines, advisors, committees, language, culture, and previous experiences in students' search and selection of dissertation topics, as well as whether and how students react to those influences during this process. Invention has been an area of research for rhetoricians for centuries, but most modern research focuses exclusively on the pre-writing process in first composition classrooms (Young, 1976). The current research collected survey and interview data from second- and third-year Ph.D. students in natural sciences, social sciences, and humanities at a large research university in the United States. 80 second- and third-year Ph.D. students completed an online survey; 11 students and four of their advisors participated in a semi-structured interview. The results demonstrate that the majority of students spent over three months in the selection of dissertation topics, and the humanities students tended to spend longer time in this process than social sciences or humanities students. Additionally, students have much in common in their perception of the criteria they would use in the selection of dissertation topics, and those criteria are similar to what previous researchers (Isaac, Koenigsknecht, Malaney, & Karras, 1989; Kozma, 1997; Sessions, 1971) have identified. However, when it comes to the actual selection experiences, the interviews show that students do not necessarily apply those criteria rationally. Moreover, disciplines appear to have an overarching effect on students' topic selection. Natural sciences advisors appeared to have more direct involvement in students' topic choice than advisors in social sciences or humanities. The linguistic and cultural backgrounds of the eleven doctoral participants were not found influential in their selection of dissertation topics. Finally, although Ph.D. advisors generally have a good understanding of students' academic progress, their knowledge of the students' personal and professional concerns may differ, and the latter knowledge is crucial in their advising on students' dissertation topic choice. The current study suggests invention in the scholar and researcher level is significantly different from that of first-year composition classrooms. The successful invention of dissertation topics is indispensable of the influence of disciplines, programs as well as the intellectual and practical support students can receive.
ContributorsXia, Jing (Author) / Matsuda, Paul K (Thesis advisor) / James, Mark (Committee member) / Renaud, Claire (Committee member) / Arizona State University (Publisher)
Created2013
Description
This research focused on how low-income communities in Ghana could convert Waste Vegetable Oil (WVO) into biodiesel to supplement their energy demands. The 2016 World Energy Outlook estimates that about 8 million Ghanaians do not have access to electricity while 82% of the population use biomass as cooking fuel. However, WVO is available in almost every home and is also largely produced by hotels and schools. There are over 2,700 registered hotels and more than 28,000 educational institutions from Basic to the Tertiary level. Currently, most WVOs are often discarded in open gutters or left to go rancid and later disposed of. Therefore, WVOs serve as cheap materials available in large quantities with a high potential for conversion into biodiesel and commercializing to support the economic needs of low-income communities. In 2013, a group of researchers at Kwame Nkrumah University of Science and Technology (KNUST) in Ghana estimated that the country could be producing between 82,361 and 85,904 tons of biodiesel from WVOs generated by hotels alone in 2015. Further analysis was also carried out to examine the Ghana National Biofuel Policy that was introduced in 2005 with support from the Ghana Energy Commission. Based on the information identified in the research, a set of recommendations were made to help the central government in promoting the biodiesel industry in Ghana, with a focus on low-income or farming communities. Lastly, a self-sustaining biodiesel production model with high potential for commercialization, was proposed to enable low-income communities to produce their own biodiesel from WVOs to meet their energy demands.
ContributorsAnnor-Wiafe, Stephen (Author) / Henderson, Mark (Thesis director) / Rogers, Bradley (Committee member) / Engineering Programs (Contributor) / Department of Management and Entrepreneurship (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
Honors colleges have offered an academically rigorous option for growing numbers of diverse students. This study took place at a large, public university that required undergraduate students to complete a thesis to graduate from the honors college. In 2017, 97% of students who began the honors thesis prior to senior year completed it. Thus, the aim of this study was to help more students begin the honors thesis process early.
Thesis Launch was a six-week intervention that was designed to provide support for students in the critical early steps of thesis work such as brainstorming topics, examining professors’ research interests, reaching out to professors, preparing for meetings with potential thesis committee members, and writing a thesis prospectus. Thesis Launch offered web-based resources, weekly emails and text message reminders, and was supplemented by in-person advising options.
A mixed methods action research study was conducted to examine: (a) students’ perceptions of barriers that prevented beginning thesis work; (b) self-efficacy towards thesis work; (c) how to scale the intervention using technology; and (d) whether participants began the thesis early. Quantitative data was collected via pre- and post-intervention surveys, journals, and prospectus submissions. Qualitative data came from student interviews, journals, and open-ended questions on the surveys.
Quantitative data showed that after students participated in Thesis Launch, they had higher self-efficacy to work with professors, perceived fewer barriers to thesis work, and greater proportions of students began thesis work early. The qualitative data were complementary and showed that participants overcame barriers to thesis initiation, built self-efficacy, preferred an online intervention, and began thesis work early. Findings also showed that a primarily technology-based intervention was preferred by students and showed promise for scaling to a larger audience.
Thesis Launch provided a framework for students to begin work on the honors thesis and have mastery experiences to build self-efficacy. Strategies that fostered “small wins” and reflective efforts also assisted in this aim. Participants accomplished tasks tied to thesis work and customized their personal thesis timelines based on work begun during Thesis Launch. Finally, a discussion of limitations, implications for practice and research, and personal reflection was included.
Thesis Launch was a six-week intervention that was designed to provide support for students in the critical early steps of thesis work such as brainstorming topics, examining professors’ research interests, reaching out to professors, preparing for meetings with potential thesis committee members, and writing a thesis prospectus. Thesis Launch offered web-based resources, weekly emails and text message reminders, and was supplemented by in-person advising options.
A mixed methods action research study was conducted to examine: (a) students’ perceptions of barriers that prevented beginning thesis work; (b) self-efficacy towards thesis work; (c) how to scale the intervention using technology; and (d) whether participants began the thesis early. Quantitative data was collected via pre- and post-intervention surveys, journals, and prospectus submissions. Qualitative data came from student interviews, journals, and open-ended questions on the surveys.
Quantitative data showed that after students participated in Thesis Launch, they had higher self-efficacy to work with professors, perceived fewer barriers to thesis work, and greater proportions of students began thesis work early. The qualitative data were complementary and showed that participants overcame barriers to thesis initiation, built self-efficacy, preferred an online intervention, and began thesis work early. Findings also showed that a primarily technology-based intervention was preferred by students and showed promise for scaling to a larger audience.
Thesis Launch provided a framework for students to begin work on the honors thesis and have mastery experiences to build self-efficacy. Strategies that fostered “small wins” and reflective efforts also assisted in this aim. Participants accomplished tasks tied to thesis work and customized their personal thesis timelines based on work begun during Thesis Launch. Finally, a discussion of limitations, implications for practice and research, and personal reflection was included.
ContributorsEardley, Trisha Lynn (Author) / Buss, Ray (Thesis advisor) / Henderson, Mark (Committee member) / Johnson, Melissa (Committee member) / Arizona State University (Publisher)
Created2019
Description
Microalgae represent a potential sustainable alternative for the enhancement and protection of agricultural crops. The dry biomass and cellular extracts of Scenedesmus dimorphus were applied as a biofertilizer, a foliar spray, and a seed primer to evaluate seed germination, plant growth, and crop yield of Roma tomato plants. The dry biomass was applied as a biofertilizer at 50 g and 100 g per plant, to evaluate its effects on plant development and crop yield. Biofertilizer treatments enhanced plant growth and led to greater crop (fruit) production. Timing of biofertilizer application proved to be of importance - earlier 50 g biofertilizer application resulted in greater plant growth. Scenedesmus dimorphus culture, growth medium, and different concentrations (1%, 5%, 10%, 25%, 50%, 75%, 100%) of aqueous cell extracts were used as seed primers to determine effects on germination. Seeds treated with Scenedesmus dimorphus culture and with extract concentrations higher than 50 % (0.75 g ml-1) triggered faster germination - 2 days earlier than the control group. Extract foliar sprays of 50 ml and 100 ml, were obtained and applied to tomato plants at various extract concentrations (10%, 25%, 50%, 75% and 100%). Plant height, flower development and number of branches were significantly enhanced with 50 % (7.5 g ml-1) extracts. Higher concentration sprays led to a decrease in growth. The extracts were further screened to assess potential antimicrobial activity against the bacterium Escherichia coli ATCC 25922, the fungi Candida albicans ATCC 90028 and Aspergillus brasiliensis ATCC 16404. No antimicrobial activity was observed from the microalga extracts on the selected microorganisms.
ContributorsGarcia-Gonzalez, Jesus (Author) / Sommerfeld, Milton (Thesis advisor) / Steele, Kelly (Committee member) / Henderson, Mark (Committee member) / Arizona State University (Publisher)
Created2014
Description
This project investigated second language writing teachers’ writing assessment literacy by looking at teachers’ practices of electronic writing portfolios (e-WPs), as well as the sources that shape L2 writing teachers’ knowledge of e-WPs in the context of multilingual First-Year Composition (FYC) classrooms. By drawing on Borg’s (2003) theory of teacher cognition and Crusan, Plakans, and Gebril’s (2016) definition of assessment literacy, I define L2 teachers’ writing assessment literacy as teachers’ knowledge, beliefs and practices of a particular assessment tool, affected by institutional factors. While teachers are the main practitioners who help students create e-WPs (Hilzensauer & Buchberger, 2009), studies on how teachers actually incorporate e-WPs in classes and what sources may influence teachers’ knowledge of e-WPs, are scant. To fill in this gap, I analyzed data from sixteen teachers’ semi-structured interviews. Course syllabi were also collected to triangulate the interview data. The interview results indicated that 37.5 % of the teachers use departmental e-WPs with the goal of guiding students throughout their writing process. 43.7 % of the teachers do not actively use e-WPs and have students upload their writing projects only to meet the writing program’s requirement at the end of the semester. The remaining 18.7 % use an alternative platform other than the departmental e-WP platform, throughout the semester. Sources influencing teachers’ e-WP knowledge included teachers’ educational and work experience, technical difficulties in the e-WP platform, writing program policies and student reactions. The analysis of the course syllabi confirmed the interview results. Based on the findings, I argue that situated in the context of classroom assessment, institutional factors plus teachers’ insufficient knowledge of e-WPs limit the way teachers communicate with students, whose reactions cause teachers to resist e-WPs. Conversely, teachers’ sufficient knowledge of e-WPs enables them to balance the pressure from the institutional factors, generating positive reactions from the students. Students’ positive reactions encourage teachers to accept the departmental e-WPs or use similar alternative e-WP platforms. Pedagogical implications, limitations of the study and suggestions for future research are reported to conclude the dissertation.
ContributorsWu, Tai-Min (Author) / Matsuda, Paul K (Thesis advisor) / James, Mark A (Committee member) / Smith, Bryan (Committee member) / Arizona State University (Publisher)
Created2018