Barrett, The Honors College Thesis/Creative Project Collection
Barrett, The Honors College at Arizona State University proudly showcases the work of undergraduate honors students by sharing this collection exclusively with the ASU community.
Barrett accepts high performing, academically engaged undergraduate students and works with them in collaboration with all of the other academic units at Arizona State University. All Barrett students complete a thesis or creative project which is an opportunity to explore an intellectual interest and produce an original piece of scholarly research. The thesis or creative project is supervised and defended in front of a faculty committee. Students are able to engage with professors who are nationally recognized in their fields and committed to working with honors students. Completing a Barrett thesis or creative project is an opportunity for undergraduate honors students to contribute to the ASU academic community in a meaningful way.
Displaying 1 - 7 of 7
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- All Subjects: Biofuels
- All Subjects: community
- Creators: School of Sustainability
Description
While biodiesel production from photosynthesizing algae is a promising form of alternative energy, the process is water and nutrient intensive. I designed a mathematical model for a photobioreactor system that filters the reactor effluent and returns the permeate to the system so that unutilized nutrients are not wasted, addressing these problems. The model tracks soluble and biomass components that govern the rates of the processes within the photobioreactor (PBR). It considers light attenuation and inhibition, nutrient limitation, preference for ammonia consumption over nitrate, production of soluble microbial products (SMP) and extracellular polymeric substance (EPS), and competition with heterotrophic bacteria that predominately consume SMP. I model a continuous photobioreactor + microfiltration system under nine unique operation conditions - three dilution rates and three recycling rates. I also evaluate the health of a PBR under different dilution rates for two values of qpred. I evaluate the success of each run by calculating values such as biomass productivity and specific biomass yield. The model shows that for low dilution rates (D = <0.2 d-1) and high recycling rates (>66%), nutrient limitation can lead to a PBR crash. In balancing biomass productivity with water conservation, the most favorable runs were those in which the dilution rate and the recycling rate were highest. In a second part of my thesis, I developed a model that describes the interactions of phototrophs and their predators. The model also shows that dilution rates corresponding to realistic PBR operation can washout predators from the system, but the simulation outputs depend heavily on the accuracy of parameters that are not well defined.
ContributorsWik, Benjamin Philip (Author) / Marcus, Andrew (Thesis director) / Rittmann, Bruce (Committee member) / School of Sustainability (Contributor) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Acyl Carrier Protein (ACP) is a small, acidic protein that plays an essential role in fatty acid synthesis by elongating fatty acid chains. ACP was isolated from an extract of a modified strain of Synechocystis sp. PCC 6803 that contains a thioesterase and from which the acyl-ACP synthetase has been deleted. Using ammonium sulfate precipitation to isolate a crude protein fraction containing ACP, immunoblot analysis was performed to determine relative amounts of free and acylated-ACP in the cell. The nature of fatty acids attached to ACP was determined by creating butylamide derivatives that were analyzed using GC/MS. Immunoblot analysis showed a roughly 1:1 ratio of acylated ACP to free ACP in the cell depending on the nutritional state of the cell. From GC/MS data it was determined that palmitic acid was the predominate component of acyl groups attached to ACP. The results indicate that there is a significant amount of acyl-ACP, a feedback inhibitor of early steps in the fatty acid biosynthesis pathway, in the cell. Moreover, the availability of free ACP may also limit fatty acid biosynthesis. Most likely it is necessary for ACP to be overexpressed or to have the palmitic acid cleaved off in order to synthesize optimal amounts of lauric acid to be used for cyanobacterial biofuel production.
ContributorsWu, Sharon Gao (Author) / Vermaas, Willem (Thesis director) / Redding, Kevin (Committee member) / School of Sustainability (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / School of Molecular Sciences (Contributor) / School of International Letters and Cultures (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
"Black in Bleu" is a reflection on my life as a young, Black woman in America told through poetry, and music in conjunction with feminist activists' work as well as results from a survey amongst other young, black students. This paper is a window into Blackness reflecting my experiences as well as many others in a way to find love in that reflection. There is a playlist that goes along with the paper meant to be listened to simultaneously with the reading.
ContributorsDowning, Ciarra (Author) / Acierto, Alejandro (Thesis director) / Reyes, Ernesto (Committee member) / Barrett, The Honors College (Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / School of Sustainability (Contributor)
Created2023-05
Description
Fossil fuels have been the primary source of energy in the world for many decades. However, they are among the top contributors of the greenhouse gas emissions in the atmosphere. The objective of this research was to produce a more environmentally friendly biofuel from Algae-Helix and Salicornia biomasses. Experiments were conducted using a hydrothermal liquefaction (HTL) technique in the HTL reactor to produce biofuel that can potentially replace fossil fuel usage. Hydrothermal Liquefaction is a method used to convert the biomass into the biofuels. HTL experiments on Algae-Helix and Salicornia at 200°C-350°C and 430psi were performed to investigate the effect of temperature on the biocrude yield of the respective biomass used. The effect of the biomass mixture (co-liquefaction) of Salicornia and algae on the amount of biocrude produced was also explored. The biocrude and biochar (by-product) obtained from the hydrothermal liquefaction process were also analyzed using thermogravimetric analyzer (TGA). The maximum biocrude yield for the algae-helix biomass and for the Salicornia biomass were both obtained at 300°C which were 34.63% and 7.65% respectively. The co-liquefaction of the two biomasses by 50:50 provided a maximum yield of 17.26% at 250°C. The co-liquefaction of different ratios explored at 250°C and 300°C concluded that Salicornia to algae-helix ratio of 20:80 produced the highest yields of 22.70% and 31.97%. These results showed that co-liquefaction of biomass if paired well with the optimizing temperature can produce a high biocrude yield. The TGA profiles investigated have shown that salicornia has higher levels of ash content in comparison with the algae-helix. It was then recommended that for a mixture of algae and Salicornia, large-scale biofuel production should be conducted at 250℃ in a 20:80 salicornia to algae biocrude ratio, since it lowers energy needs. The high biochar content left can be recycled to optimize biomass, and prevent wastage.
ContributorsLuboowa, Kato Muhammed (Co-author) / Laideson, Maymary (Co-author) / Deng, Shuguang (Thesis director) / Nielsen, David (Committee member) / Chemical Engineering Program (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
The algal fuel industry has existed since the 1980s without fully commercializing a product. Algal fuels are potentially viable replacements for fossil fuels due to their fast cultivation, high oil content, carbon dioxide sequestration during growth, and ability to be grown on non-arable land. For this thesis, six companies from 61 investigated were interviewed about their history with biofuels, technological changes they have gone through, and views for the future of the industry. All companies interviewed have moved away from fuel production largely due to high production costs and have moved primarily toward pharmaceuticals and animal feed production as well as wastewater treatment. While most do not plan to return to the biofuel industry in the near future, a return would likely require additional legislation, increased technological innovation, and coproduction of multiple products.
ContributorsMassey, Alexandria Rae (Author) / Parker, Nathan (Thesis director) / Agusdinata, Buyung (Committee member) / Chemical Engineering Program (Contributor, Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Food waste is a significant problem in many developed nations, especially the United States. Each year millions of pounds of uneaten or partially eaten food scraps are thrown into landfill, where it degrades anaerobically, producing methane gas emissions, contributing to foul odors, and contributing to an unsustainable food system. This thesis project set out to conduct a small-scale composting system that diverted would-be food waste from a local food bank to a community garden, where food scraps would decompose into compost to then be turned into a valuable, nutrient-rich amendment in that local garden. Engaging with this food bank and community garden allowed us to leverage the existing relationship between the two, and experiment and develop a framework that would demonstrate the feasibility of a long-term composting system in this community. By conducting this project throughout 2021, we saw where strategies worked well, what challenges remained, and where future opportunities could be expanded on. In the end, we diverted over 2000 lbs of uneaten food away from the food bank and into our composting system. We concluded our project report by providing a set of actionable recommendations and future framework guidelines that could be used by the local community garden in the future or be referenced to by other interested parties.
ContributorsBardon, Lee (Author) / Marshall, Meghan (Co-author) / Nelson, Melissa (Thesis director) / Winburn, Morgan (Committee member) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2021-12
Description
Food waste is a significant problem in many developed nations, especially the United States. Each year millions of pounds of uneaten or partially eaten food scraps are thrown into landfill, where it degrades anaerobically, producing methane gas emissions, contributing to foul odors, and contributing to an unsustainable food system. This thesis project set out to conduct a small-scale composting system that diverted would-be food waste from a local food bank to a community garden, where food scraps would decompose into compost to then be turned into a valuable, nutrient-rich amendment in that local garden. Engaging with this food bank and community garden allowed us to leverage the existing relationship between the two, and experiment and develop a framework that would demonstrate the feasibility of a long-term composting system in this community. By conducting this project throughout 2021, we saw where strategies worked well, what challenges remained, and where future opportunities could be expanded on. In the end, we diverted over 2000 lbs of uneaten food away from the food bank and into our composting system. We concluded our project report by providing a set of actionable recommendations and future framework guidelines that could be used by the local community garden in the future or be referenced to by other interested parties.
ContributorsMarshall, Meghan (Author) / Bardon, Lee (Co-author) / Nelson, Melissa (Thesis director) / Winburn, Morgan (Committee member) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2012-12