Matching Items (12)
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
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
Sustainable production of microalgae for biofuel requires efficient phosphorus (P) utilization, which is a limited resource and vital for global food security. This research tracks the fate of P through biofuel production and investigates P recovery from the biomass using the cyanobacterium Synechocystis sp. PCC 6803. Our results show that Synechocystis contained 1.4% P dry weight. After crude lipids were extracted (e.g., for biofuel processing), 92% of the intracellular P remained in the residual biomass, indicating phospholipids comprised only a small percentage of cellular P. We estimate a majority of the P is primarily associated with nucleic acids. Advanced oxidation using hydrogen peroxide and microwave heating released 92% of the cellular P into orthophosphate. We then recovered the orthophosphate from the digestion matrix using two different types of anion exchange resins. One resin impregnated with iron nanoparticles adsorbed 98% of the influent P through 20 bed volumes, but only released 23% during regeneration. A strong-base anion exchange resin adsorbed 87% of the influent P through 20 bed volumes and released 50% of it upon regeneration. This recovered P subsequently supported growth of Synechocystis. This proof-of-concept recovery process reduced P demand of biofuel microalgae by 54%.
ContributorsGifford, McKay (Author) / Liu, Jianyong (Author) / Rittmann, Bruce (Author) / Vannela, Raveender (Author) / Westerhoff, Paul (Author) / Ira A. Fulton School of Engineering (Contributor) / School of Sustainable Engineering and the Built Environment (Contributor) / Biodesign Institute (Contributor) / Swette Center for Environmental Biotechnology (Contributor)
Created2015-03-01
Description
Inhibition by ammonium at concentrations above 1000 mgN/L is known to harm the methanogenesis phase of anaerobic digestion. We anaerobically digested swine waste and achieved steady state COD-removal efficiency of around 52% with no fatty-acid or H[subscript 2] accumulation. As the anaerobic microbial community adapted to the gradual increase of total ammonia-N (NH[subscript 3]-N) from 890 ± 295 to 2040 ± 30 mg/L, the Bacterial and Archaeal communities became less diverse. Phylotypes most closely related to hydrogenotrophic Methanoculleus (36.4%) and Methanobrevibacter (11.6%), along with acetoclastic Methanosaeta (29.3%), became the most abundant Archaeal sequences during acclimation. This was accompanied by a sharp increase in the relative abundances of phylotypes most closely related to acetogens and fatty-acid producers (Clostridium, Coprococcus, and Sphaerochaeta) and syntrophic fatty-acid Bacteria (Syntrophomonas, Clostridium, Clostridiaceae species, and Cloacamonaceae species) that have metabolic capabilities for butyrate and propionate fermentation, as well as for reverse acetogenesis. Our results provide evidence countering a prevailing theory that acetoclastic methanogens are selectively inhibited when the total ammonia-N concentration is greater than ~1000 mgN/L. Instead, acetoclastic and hydrogenotrophic methanogens coexisted in the presence of total ammonia-N of ~2000 mgN/L by establishing syntrophic relationships with fatty-acid fermenters, as well as homoacetogens able to carry out forward and reverse acetogenesis.
ContributorsEsquivel Elizondo, Sofia (Author) / Parameswaran, Prathap (Author) / Delgado, Anca (Author) / Maldonado, Juan (Author) / Rittmann, Bruce (Author) / Krajmalnik-Brown, Rosa (Author) / Biodesign Institute (Contributor) / Swette Center for Environmental Biotechnology (Contributor) / Ira A. Fulton School of Engineering (Contributor) / School of Sustainable Engineering and the Built Environment (Contributor)
Created2016-08-11
Description
Recent studies indicate the presence of nano-scale titanium dioxide (TiO[subscript 2]) as an additive in human foodstuffs, but a practical protocol to isolate and separate nano-fractions from soluble foodstuffs as a source of material remains elusive. As such, we developed a method for separating the nano and submicron fractions found in commercial-grade TiO[subscript 2] (E171) and E171 extracted from soluble foodstuffs and pharmaceutical products (e.g., chewing gum, pain reliever, and allergy medicine). Primary particle analysis of commercial-grade E171 indicated that 54% of particles were nano-sized (i.e., < 100 nm). Isolation and primary particle analysis of five consumer goods intended to be ingested revealed differences in the percent of nano-sized particles from 32%‒58%. Separation and enrichment of nano- and submicron-sized particles from commercial-grade E171 and E171 isolated from foodstuffs and pharmaceuticals was accomplished using rate-zonal centrifugation. Commercial-grade E171 was separated into nano- and submicron-enriched fractions consisting of a nano:submicron fraction of approximately 0.45:1 and 3.2:1, respectively. E171 extracted from gum had nano:submicron fractions of 1.4:1 and 0.19:1 for nano- and submicron-enriched, respectively. We show a difference in particle adhesion to the cell surface, which was found to be dependent on particle size and epithelial orientation. Finally, we provide evidence that E171 particles are not immediately cytotoxic to the Caco-2 human intestinal epithelium model. These data suggest that this separation method is appropriate for studies interested in isolating the nano-sized particle fraction taken directly from consumer products, in order to study separately the effects of nano and submicron particles.
ContributorsFaust, James (Author) / Doudrick, Kyle (Author) / Yang, Yu (Author) / Capco, David (Author) / Westerhoff, Paul (Author) / College of Liberal Arts and Sciences (Contributor) / Molecular and Cellular Biology (Contributor) / School of Life Sciences (Contributor) / Ira A. Fulton School of Engineering (Contributor) / School of Sustainable Engineering and the Built Environment (Contributor)
Created2016-10-31
Description
pH and fermentable substrates impose selective pressures on gut microbial communities and their metabolisms. We evaluated the relative contributions of pH, alkalinity, and substrate on microbial community structure, metabolism, and functional interactions using triplicate batch cultures started from fecal slurry and incubated with an initial pH of 6.0, 6.5, or 6.9 and 10 mM glucose, fructose, or cellobiose as the carbon substrate. We analyzed 16S rRNA gene sequences and fermentation products. Microbial diversity was driven by both pH and substrate type. Due to insufficient alkalinity, a drop in pH from 6.0 to ~4.5 clustered pH 6.0 cultures together and distant from pH 6.5 and 6.9 cultures, which experienced only small pH drops. Cellobiose yielded more acidity than alkalinity due to the amount of fermentable carbon, which moved cellobiose pH 6.5 cultures away from other pH 6.5 cultures. The impact of pH on microbial community structure was reflected by fermentative metabolism. Lactate accumulation occurred in pH 6.0 cultures, whereas propionate and acetate accumulations were observed in pH 6.5 and 6.9 cultures and independently from the type of substrate provided. Finally, pH had an impact on the interactions between lactate-producing and -consuming communities. Lactate-producing Streptococcus dominated pH 6.0 cultures, and acetate- and propionate-producing Veillonella, Bacteroides, and Escherichia dominated the cultures started at pH 6.5 and 6.9. Acid inhibition on lactate-consuming species led to lactate accumulation. Our results provide insights into pH-derived changes in fermenting microbiota and metabolisms in the human gut.
ContributorsIlhan, Zehra (Author) / Marcus, Andrew (Author) / Kang, Dae-Wook (Author) / Rittmann, Bruce (Author) / Krajmalnik-Brown, Rosa (Author) / Biodesign Institute (Contributor) / Swette Center for Environmental Biotechnology (Contributor) / College of Liberal Arts and Sciences (Contributor) / School of Life Sciences (Contributor) / Fundamental and Applied Microbiomics (Contributor) / Ira A. Fulton School of Engineering (Contributor) / School of Sustainable Engineering and the Built Environment (Contributor)
Created2017-05-03
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 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 research and design project proposes an active (resilient/adaptive) architecture to address the problem of natural disasters in developing communities. Natural disasters are the outcome created when mankind stops listening and learning to the surrounding environment. They are like any other natural hazard created by the environment, or human activity, the only difference is that natural disasters are destructive, claiming lives and damaging economies of affected areas. Research shows that it is more expensive for a community to recover from a disaster than it is to prevent it from happening in the first place or trying to prevent factors that might increase fatality. Therefore, rather than dealing with the after-effects, this project proposes solutions for the prevention of the adverse effects of natural disasters during the process of building rural communities \u2014 to better adapt for those events. Furthermore, research has shown that natural disasters have little power in taking lives and weakening economies alone. In his book, 2000 Years of Mayan Literature, Professor of Anthropology Dennis Tedlock, explains that many historical civilizations collapsed in part due to the inadequate relationship between society and the environmental conditions upon which societies rely. He compares this situation with our own, pointing to the parallel between the isolation of Easter Island, set apart by the vast wastes of the Pacific Ocean, with the isolation of the Earth in space. Tedlock's statement remains relevant in our time, yet mankind still turns a blind eye, and together with unprepared infrastructure, natural disasters can become exceedingly devastating and have long-term destructive effects. Active Architecture is the form of architecture that adapts to challenges and reacts to them accordingly and repeatedly, according to challenges introduces and forces present. Architecture plays a huge role in how natural disasters are dealt handled. In an interview with Arbuckle Industries, architect and humanitarian Shigeru Ban argues that natural disasters are manmade. He says that the earthquake alone cannot kill a person, the collapse of a building does. The actions of mankind are implicit in the massive destruction when a disaster occurs. Ban stresses it is the responsibility of an architect to make safe spaces. My proposal is that safe spaces can be created through active architecture. One example of active architecture is the civilization created by the people of Badjao, a 21st-century sea people. They are a relevant case study in my research because of their five (5) core technics in creating their active architecture: 1) architecture can be collective initiative, 2) adaptability goes beyond the building, 3) successful design can be born from fragility instead of stability, 4) listen to their environment, and 5) use surroundings and ecological impact as the defining qualities of their work in the long-term. In this paper, I will discuss the techniques of active architecture through a study of natural disasters in the form of landslides that occur often in my native country, Rwanda. Landslides, floods, droughts and heavy rain all routinely affect the country, however, landslides are the most urgent problem to be dealt with. In the final section of my paper, I use my research to develop an architectural solution to the issue of landslides in Rwanda and I project what the future of the country could look like if the proposal is implemented. The proposal describes a more active form of architecture that is responsive to the site and offers a resilient yet solid infrastructural solution to the problem of landslides.
ContributorsKarenzi, Emery (Author) / Vekstein, Claudio (Thesis director) / Hejduk, Renata (Committee member) / Mesa, Felipe (Committee member) / The Design School (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05