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- Member of: Theses and Dissertations
Description
It is the intent of this research to determine the feasibility of utilizing industrial byproducts in cementitious systems in lieu of Portland Cement to reduce global CO2 emissions. Class C and Class F Fly Ash (CFA and FFA, respectively) derived from industrial coal combustion were selected as the replacement materials for this study. Sodium sulfate and calcium oxide were used as activators. In Part 1 of this study, focus was placed on high volume replacement of OPC using sodium sulfate as the activator. Despite improvements in heat generation for both CFA and FFA systems in the presence of sulfate, sodium sulfate was found to have adverse effects on the compressive strength of CFA mortars. In the CFA mixes, strength improved significantly with sulfate addition, but began to decrease in strength around 14 days due to expansive ettringite formation. Conversely, the addition of sulfate led to improved strength for FFA mixes such that the 28 day strength was comparable to that of the CFA mixes with no observable strength loss. Maximum compressive strengths achieved for the high volume replacement mixes was around 40 MPa, which is considerably lower than the baseline OPC mix used for comparison. In Part 2 of the study, temperature dependency and calcium oxide addition were studied for sodium sulfate activated systems composed of 100% Class F fly ash. In the presence of sulfate, added calcium increased reactivity and compressive strength at early ages, particularly at elevated temperatures. It is believed that sulfate and calcium react with alumina from fly ash to form ettringite, while heat overcomes the activation energy barrier of fly ash. The greatest strengths were obtained for mixes containing the maximum allowed quantity of calcium oxide (5%) and sodium sulfate (3%), and were around 12 MPa. This is a very low compressive strength relative to OPC and would therefore be an inadequate substitute for OPC needs.
ContributorsTweedley, Shannon Elizabeth (Author) / Neithalath, Narayanan (Thesis director) / Mamlouk, Michael (Committee member) / Civil, Environmental and Sustainable Engineering Programs (Contributor) / Barrett, The Honors College (Contributor) / School of Sustainable Engineering and the Built Environment (Contributor)
Created2014-05
Description
Lactate and methanol have been the most commonly used electron donors in the Krajmalnik-Brown laboratory for efficient microbial dechlorination of trichloroethene (TCE). Our goal was to assess the technical and economic feasibility of molasses and ethanol, two alternative electron donors by evaluating their costs and ability support complete TCE dechlorination to ethene. First, ethanol and molasses, with and without methanol, were evaluated for their abilities to support complete dechlorination in batch serum bottles. Molasses, the cheapest alternative, supported a similar dechlorination performance to lactate in batch experiments, so we then used it in an upflow anaerobic bioreactor (UABR) to test its ability to support rapid dechlorination in this continuous system. Molasses supported 88% TCE conversion to ethene at a hydraulic retention time (HRT) of 13 hours after 80 days of operation in continuous mode. Compared to the UABR operated previously using lactate and methanol, molasses led to a reduction of TCE conversion to ethene, and a possible increase in time required to produce culture. Additionally, when molasses was used as the electron donor, we encountered new difficulties in the operation of the UABR, such as drastic pH changes. Therefore, I conclude that the savings from using molasses is outweighed by the costs associated with the reduction in dechlorination performance and increase in reactor maintenance. I recommend that lactate and methanol continue to be used as the electron donors in the Krajmalnik- Brown dechlorination lab to support fast-rate and cost-effective production of dechlorinating culture in an UABR. Because molasses supported fast rates of dechlorination in the batch experiment, however, it is potentially a better option than lactate and methanol for batch production of culture or for biostimulation, where the aquifer resembles a batch system. I recommend that further studies be done to reach a general conclusion about the feasibility of molasses as an electron donor for other enhanced bioremediation projects.
ContributorsBondank, Emily Nicole (Author) / Krajmalnik-Brown, Rosa (Thesis director) / Delgado, Anca (Committee member) / Torres, Cesar (Committee member) / Civil, Environmental and Sustainable Engineering Programs (Contributor) / Barrett, The Honors College (Contributor)
Created2014-12
Description
As existing typologies and precedents that integrate music into architectural form don’t pay careful consideration to the composer’s intent and technique of the score into built structure and its program, the goal is propose a new architecture that integrates the site, program, and acoustics. Scenes from Childhood (Kinderszenen), composed by Robert Schumann, depict memories, dreams, hopes, candor, and games- all lost in paradise. Schumann composed the piece as an adult, reminiscing of his childhood. The rising 6th with a four-note falling figure is the main motif. The motif opens the 1st movement, reappears in the 2nd, 4th, and 11th, and is transposed in the 6th, 7th, and 9th. This motif and the implications of each movement, as well as the piece as a whole, became the organizing principle in defining form, program, and experience: a public park wedged between two elementary schools in a low-income neighborhood in Los Angeles, California. The proposal aims to integrate the lack of the two institutions’ music programs into the experience of the 13 pavilions that reflect the 13 movements in Schumann’s piece. The manifestation of the final project was just as important as the process; the program is developed through the score, and the architectural is supported by the musical curriculum as well as Schumann’s intent.
ContributorsKim, Cecile (Author) / Vekstein, Claudio (Thesis director) / Mclean, Elizabeth (Committee member) / The Design School (Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Throughout history people have used storytelling to leave remnants of their life and culture in the world. From the ancient cave paintings to the Egyptian hieroglyphics and from Greek mythologies to our modern-day novels, storytelling reflects parts another person’s life from a different time and place. Stories have a way of taking us out of our place in time and sending us into a realm created by the storyteller. We listen and tell stories every day to the people around us, whether they are our own stories or another person’s story. It is how we connect with each other intimately. Through storytelling, you give your audience a glimpse into your mind, the way you think and the way you perceive the world by how you illustrate the story. Architects create the frame for the user to define the space and the opportunity for the narrative of the user to be reflected in the frame and space of the architecture. Storytelling is used in architecture to bring the audience into the narrative constructed by the architect to create the experience. For my in-studio thesis project, I created a short film to tell the story of the Architectural Studio VI class. The images and video footage that I included are used to allow the audience to have a glimpse of what the life and environment of studio was like as the students were working collaboratively and independently to develop their designs. I produced this film with the intention to not only tell the story of the Architectural Studio VI class but to also bring my audience into the story through the images and video footage.
ContributorsHartono, Tiffany (Author) / Spellman, Catherine (Thesis director) / Vekstein, Claudio (Committee member) / Mesa Rico, Juan Felipe (Committee member) / The Design School (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
The effect of an anaerobic reductive environment produced by the oxidation of zero valent iron (ZVI) on the microbial reductive dechlorination of trichloroethylene and its applicability to in-situ bioremediation processes was investigated using microcosms and soil column studies. I learned that microbial dechlorination requires a highly reductive environment, as represented by negative values for oxidation-reduction potential (ORP), which can be maintained through the addition of reducing agents such as ZVI, or to a lesser extent, the fermentation of added substrates such as lactate. Microcosm conditions represented distance from an in-situ treatment injection well and contained different types of iron species and dechlorinating bioaugmentation cultures. Diminishing efficacy of microbial reductive dechlorination along a gradient away from the injection zone was observed, characterized by increasing ORP and decreasing pH. Results also suggested that the use of particular biostimulation substrates is key to prioritizing the dechlorination reaction against competing microbial and abiotic processes by supplying electrons needed for microbial dechlorination.
ContributorsMouti, Aatikah (Author) / Krajmalnik-Brown, Rosa (Thesis director) / Delgado, Anca (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
The purpose of this text is to research and specify inequities present within three South American cities; Medellin, Columbia, Mexico City, Mexico, and Rio de Janeiro, Brazil. This research then considers specific neighborhoods within these cities that have become underprivileged as a result of the inequities, and analyzes architectural insertions that have been placed in these communities in hopes of balancing the inequities secluding the communities from the rest of the city. With the information gathered from the three case study cities, another city, Tijuana, Mexico, is examined and ascertained as to what type of inequities are present. Using the methodology implemented in the case studies, a specific architectural insertion is proposed in relation to the problems at hand, with the intent of balancing the inequalities present in an underprivilege neighborhood in Tijuana. Ultimately, the text strives to demonstrate the power of architectural insertions within a community, while highlighting the importance of the effects upon the daily lives of the inhabitants, as well as the dynamics within the community and greater city.
ContributorsBorie, Isabelle Ethelbah (Author) / Spellman, Catherine (Thesis director) / Vekstein, Claudio (Committee member) / Hejduk, Renata (Committee member) / The Design School (Contributor) / School of Sustainable Engineering and the Built Environment (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
This project addresses the high demand of housing units in the Gila River Indian Community and proposes an architectural intervention with the intent of bringing tribal culture into the everyday context of the home. Initially, the existing condition is critiqued from an architectural and cultural lens, and establishes the current realities of the residents. An investigation of the existing condition and the surrounding context determined that the immediate contradiction to the existing house is the storytelling tradition of the Akimel O'odham and Pee Posh tribes. This project accepts and revises the existing condition and attempts to combine it with the fundamental traits of storytelling culture to create a house that encourages storytelling across generations, and serves as a space that allows residents to practice culture in the every day.
ContributorsGreene, Joshua Michael (Author) / Vekstein, Claudio (Thesis director) / Hejduk, Renata (Committee member) / Malnar, Joy (Committee member) / W. P. Carey School of Business (Contributor) / The Design School (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
Hydrogen is a key indicator of microbial activity in soils/sediments and groundwater because of its role as an electron donor for reducing sulfate and nitrate and carrying out other metabolic processes. The goal of this study was to quantitatively measure the total biological hydrogen demand (TBHD) of soils and sediments in anaerobic environments. We define the total biological hydrogen demand as the sum of all electron acceptors that can be used by hydrogen-oxidizing microorganisms. Three sets of anaerobic microcosms were set up with different soils/sediments, named Carolina, Garden, and ASM. The microcosms included 25g of soil/sediment and 75 mL of anaerobic medium. 10 mL of hydrogen were pulse-fed for 100 days. Hydrogen consumption and methane production were tracked using gas chromatography. Chemical analysis of each soil was performed at the beginning of the experiment to determine the concentration of electron acceptors in the soils/sediments, including nitrate, sulfate, iron and bicarbonate. An analysis of the microbial community was done at t = 0 and at the end of the 100 days to examine changes in the microbial community due to the metabolic processes occurring as hydrogen was consumed. Carolina consumed 9810 43 mol of hydrogen and produced 19,572 2075 mol of methane. Garden consumed 4006 33 mol of hydrogen and produced 7,239 543 mol of methane. Lastly, ASM consumed 1557 84 mol of hydrogen and produced 1,325 715 mol of methane. I conclude that the concentration of bicarbonate initially present in the soil had the most influence over the hydrogen demand and microbial community enrichment. To improve this research, I recommend that future studies include a chemical analysis of final soil geochemistry conditions, as this will provide with a better idea of what pathway the hydrogen is taking in each soil.
ContributorsLuna Aguero, Marisol (Author) / Krajmalnik-Brown, Rosa (Thesis director) / Delgado, Anca (Committee member) / Civil, Environmental and Sustainable Engineering Programs (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
This is an applied research paper, where a micro campus was designed for the San Carlos Apache Community with a goal of meeting requirements for at least three petals of Living Building Challenge. The end goal was to submit recommendations for attaining the petal certifications. The process of design not only included following spatial requirements of designing the building, but also including a wider perspective of construction and energy management in it. The first step of the research was getting to know the community and their requirements and priorities. This was done in 1st semester as a part of an applied class Indigenous Project Delivery. The second part of the research was to design a micro campus for the community that is in sync with the main campus. The intent of design is to respect the community’s culture and help them pass it on to the next generation while abiding by the Living Building Challenge standards. The third step of this research was to back up the design with recommendations for petal certifications.
ContributorsSingaraju, Meghana (Author) / Costa, Wanda Dalla (Thesis advisor) / Coseo, Paul (Committee member) / Vekstein, Claudio (Committee member) / Parrish, Kristen (Committee member) / Arizona State University (Publisher)
Created2022
Description
In the realm of environmental engineering, the compound N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD), has recently emerged as an environmental concern. 6PPD serves as a tire additive to prolong the lifespan of rubber but can transform into a more toxic derivative, N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine-quinone (6PPD-quinone), when exposed to ground-level ozone. Initially, my research sought to investigate the biodegradation of 6PPD and 6PPD-quinone using microbial cultures. However, unexpected challenges arising from limited solubility and potential toxicity to microorganisms led to a shift in research objectives. The study then refocused on developing methods for detecting and quantifying 6PPD and 6PPD-quinone. The scarcity of literature available on the environmental fate and transport of these compounds underscores the pressing need for further research to gain a comprehensive understanding of the behavior of these chemicals. Consequently, the development of effective detection strategies will enable the development of effective remediation strategies to safeguard aquatic ecosystems.
ContributorsKoenig-Vinicombe, Ryan (Author) / Delgado, Anca (Thesis director) / Skinner, Justin (Committee member) / Barrett, The Honors College (Contributor) / College of Integrative Sciences and Arts (Contributor) / School of Sustainability (Contributor) / School of Sustainable Engineering & Built Envirnmt (Contributor)
Created2023-12