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- All Subjects: Sustainability
- All Subjects: Chemistry
- Creators: Arizona State University
- Status: Published
Description
Rising inequality is a defining challenge in the 21st century and although the 2030 agenda for sustainable development is far from perfect, its commitment to tackling inequalities is praiseworthy. To this end, a deeper understanding of how social inequality affects sustainable development can help us rethink development policies and practices. Social inequality is multidimensional and in the last two decades, there has been an upsurge of research in this area. However, these research do not provide a comprehensive understanding of the nature and extent of inequality and its impact on the United Nations Sustainable Development Goals. In particular, they ignore important dimensions such as wealth and the environment in their analysis. In this dissertation, the discourse on how inequality has evolved is first explored and the analysis reveals that the inequality discourse has shifted from its early focus on the measurement of conditions, defined as the unequal distribution of income and/or material goods, towards a more comprehensive approach of measuring inequality of opportunities. Second, the dissertation examines the short run and long run relationship between social inequality and sustainable development. This is achieved by relying on panel data for 142 countries using the Coefficient of Human Inequality and the Sustainable Development Goals Index and the findings reveal that social inequality and sustainable development share a negative relationship which appears to be robust to the inclusion of controls and the country’s level of development. Finally, this dissertation examines the inequality situation in Guyana by relying on a survey of 403 households and in doing so it computes a measure of social inequality using the Atkinson index along with the dimensions of income, education, health, wealth and the environment. The dissertation finds that Guyana is experiencing a high level of social inequality and it is hindering the country’s progress on the sustainable development goals.
ContributorsArmstrong, Sydney (Author) / Chhetri, Netra NC (Thesis advisor) / Hernandez-Cortes, Danae DHC (Committee member) / Chhetri, Nalini NC (Committee member) / Arizona State University (Publisher)
Created2023
Description
The cost of capturing carbon dioxide (CO2) from ambient air needs to be greatly reduced if it is to contribute significantly to mitigating climate change. Ion-exchange resin (IER) with quaternary ammonium cation binds CO2 when dry and releases it when wet without supplemental energy, making the process attractive for economical Direct Air Capture (DAC). In this study, a design case basis was developed for a system of collectors capable of capturing 1000 tons/day of CO2 via moisture swing sorption. The model uses varying weather parameters such as temperature, wind speed, and relative humidity to understand the impact of weather on the sorbent loading, cycle time (capture and regeneration), and net water loss. Two independent isotherm models, namely Flory Huggins and the modified Langmuir isotherm model were used to estimate the water and CO2 loading of the resin respectively as a function of relative humidity. The capture model suggests a higher capture rate during the summer and daytime (in a diurnal cycle) as the relative humidity is lower. A design optimization model was developed to minimize the capture time and maximize the sorbent loading. The crude rate production and the net water loss can help conduct an economic analysis to determine the cost of carbon capture.
ContributorsTalha, Mohammad Abu (Author) / Green, Matthew (Thesis advisor) / Lackner, Klaus (Committee member) / Cirucci, John (Committee member) / Arizona State University (Publisher)
Created2023
Description
University-level sustainability education in Western academia attempts to focus on eliminating future harm to people and the planet. However, Western academia as an institution upholds systems of oppression and reproduces settler colonialism. This reproduction is antithetical to sustainability goals as it continues patterns of Indigenous erasure and extractive relationships to the Land that perpetuate violence towards people and the planet. Sustainability programs, however, offer several frameworks, including resilience, that facilitate critical interrogations of social-ecological systems. In this thesis, I apply the notion of resilience to the perpetuation of settler colonialism within university-level sustainability education. Specifically, I ask: How is settler colonialism resilient in university-level sustainability education? How are, or could, sustainability programs in Western academic settings address settler colonialism? Through a series of conversational interviews with faculty and leadership from Arizona State University School of Sustainability, I analyzed how university-level sustainability education is both challenging and shaped by settler colonialism. These interviews focused on faculty perspectives on the topic and related issues; the interviews were analyzed using thematic coding in NVivo software. The results of this project highlight that many faculty members are already concerned with and focused on challenging settler colonialism, but that settler colonialism remains resilient in this system due to feedback loops at the personal level and reinforcing mechanisms at the institutional level. This research analyzes these feedback loops and reinforcing mechanisms, among others, and supports the call for anti-colonial and decolonial reconstruction of curriculum, as well as a focus on relationship building, shifting of mindset, and school-wide education on topics of white supremacy, settler colonialism, and systems of oppression in general.
ContributorsBills, Haven (Author) / Klinsky, Sonja (Thesis advisor) / Goebel, Janna (Committee member) / Schoon, Michael (Committee member) / Arizona State University (Publisher)
Created2022
Description
Banded iron formations (BIFs) are among the earliest possible indicators for oxidation of the Archean biosphere. However, the origin of BIFs remains debated. Proposed formation mechanisms include oxidation of Fe(II) by O2 (Cloud, 1973), photoferrotrophy (Konhauser et al., 2002), and abiotic UV photooxidation (Braterman et al., 1983; Konhauser et al., 2007). Resolving this debate could help determine whether BIFs are really indicators of O2, biological activity, or neither.
To examine the viability of abiotic UV photooxidation of Fe, laboratory experiments were conducted in which Fe-bearing solutions were irradiated with different regions of the ultraviolet (UV) spectrum and Fe oxidation and precipitation were measured. The goal was to revisit previous experiments that obtained conflicting results, and extend these experiments by using a realistic bicarbonate buffered solution and a xenon (Xe) lamp to better match the solar spectrum and light intensity.
In experiments reexamining previous work, Fe photooxidation and precipitation was observed. Using a series of wavelength cut-off filters, the reaction was determined not to be caused by light > 345 nm. Experiments using a bicarbonate buffered solution, simulating natural waters, and using unbuffered solutions, as in prior work showed the same wavelength sensitivity. In an experiment with a Xe lamp and realistic concentrations of Archean [Fe(II)], Fe precipitation was observed in hours, demonstrating the ability for photooxidation to occur significantly in a simulated natural setting.
These results lead to modeled Fe photooxidation rates of 25 mg Fe cm-2 yr-1—near the low end of published BIF deposition rates, which range from 9 mg Fe cm-2 yr-1 to as high as 254 mg Fe cm-2 yr-1 (Konhauser et al., 2002; Trendall and Blockley, 1970). Because the rates are on the edge and the model has unquantified, favorable assumptions, these results suggest that photooxidation could contribute to, but might not be completely responsible for, large rapidly deposited BIFs such those in the Hamersley Basin. Further work is needed to improve the model and test photooxidation with other solution components. Though possibly unable to fully explain BIFs, UV light has significant oxidizing power, so the importance of photooxidation in the Archean as an environmental process and its impact on paleoredox proxies need to be determined.
To examine the viability of abiotic UV photooxidation of Fe, laboratory experiments were conducted in which Fe-bearing solutions were irradiated with different regions of the ultraviolet (UV) spectrum and Fe oxidation and precipitation were measured. The goal was to revisit previous experiments that obtained conflicting results, and extend these experiments by using a realistic bicarbonate buffered solution and a xenon (Xe) lamp to better match the solar spectrum and light intensity.
In experiments reexamining previous work, Fe photooxidation and precipitation was observed. Using a series of wavelength cut-off filters, the reaction was determined not to be caused by light > 345 nm. Experiments using a bicarbonate buffered solution, simulating natural waters, and using unbuffered solutions, as in prior work showed the same wavelength sensitivity. In an experiment with a Xe lamp and realistic concentrations of Archean [Fe(II)], Fe precipitation was observed in hours, demonstrating the ability for photooxidation to occur significantly in a simulated natural setting.
These results lead to modeled Fe photooxidation rates of 25 mg Fe cm-2 yr-1—near the low end of published BIF deposition rates, which range from 9 mg Fe cm-2 yr-1 to as high as 254 mg Fe cm-2 yr-1 (Konhauser et al., 2002; Trendall and Blockley, 1970). Because the rates are on the edge and the model has unquantified, favorable assumptions, these results suggest that photooxidation could contribute to, but might not be completely responsible for, large rapidly deposited BIFs such those in the Hamersley Basin. Further work is needed to improve the model and test photooxidation with other solution components. Though possibly unable to fully explain BIFs, UV light has significant oxidizing power, so the importance of photooxidation in the Archean as an environmental process and its impact on paleoredox proxies need to be determined.
ContributorsCastleberry, Parker (Author) / Anbar, Ariel D (Thesis advisor) / Herckes, Pierre (Committee member) / Lyons, James (Committee member) / Arizona State University (Publisher)
Created2017
Description
Demand for specialty coffee worldwide is increasing, yet producers primarily located in developing countries struggle to cover their production costs and sustain their livelihood. Coffee producers are globally seeking higher profits by adapting their conventional production practices to be more socially and environmentally responsible. This dissertation aims to analyze the U.S. import demand for coffee and investigate consumer preferences and willingness to pay for coffee labels representing sustainability efforts. Chapter one introduces the coffee industry and the three chapters of this research. In the second chapter, I analyze the influence of consumers' values and the warm glow effect of giving on their willingness to pay for sustainable coffee using a non-hypothetical auction mechanism. I use an information treatment to test the effect of information on consumers' willingness to pay. Providing information increases the premium consumers are willing to pay for sustainable coffee. Regarding values, consumers that like coffee and experience the warm glow of giving are willing to pay a premium for coffee with a sustainability label. Using a hypothetical online choice experiment, in the third chapter, I investigate coffee consumers' preferences and willingness to pay for Fair Trade, Direct Trade, Rainforest Alliance and USDA Organic coffee. I find that consumers value sustainability labels that aim to solve social issues more than those whose primary goal is to solve environmental problems. I find that when two labels are together on a coffee bag, there is no effect on consumers’ utility. However, there is a positive effect on consumers' willingness to pay for coffee labeled simultaneously for Fair Trade and Organic, and simultaneously for Direct Trade and Organic. In the fourth chapter, I estimate coffee price elasticities between major coffee exporters to the U.S. and calculate pass-through import cost using a system-wide differential demand system. I compare imports of arabica and robusta green coffee and estimate the degree to which they complement each other or substitute one another. I find that arabica and robusta from Brazil, Colombia, and Mexico are substitutes but some exceptions show a complementary relationship. The inclusion of the exchange rate into the demand system has a significant effect on U.S. coffee demand. I find an incomplete pass-through cost of the exchange rate to U.S. import prices.
Chapter six concludes by summarizing the results of this dissertation and discussing the future challenges for the coffee industry.
ContributorsFuller, Katherine (Author) / Grebitus, Carola (Thesis advisor) / Schmitz, Troy (Committee member) / Hughner, Renee (Committee member) / Arizona State University (Publisher)
Created2022
Description
Late first row transitional metals have attracted attention for the development of sustainable catalysts due to their low cost and natural abundance. This dissertation discusses the utilization of redox-active ligands to overcome one electron redox processes exhibited by these base metals. Previous advances in carbonyl and carboxylate hydrosilylation using redox active ligand-supported complexes such as (Ph2PPrPDI)Mn and (Ph2PPrDI)Ni have been reviewed in this thesis to set the stage for the experimental work described herein.The synthesis and electronic structure of late first row transition metal complexes featuring the Ph2PPrPDI chelate was pursued. Utilizing these complexes as catalysts for a variety of reactions gave a recurring trend in catalytic activity. DFT calculations suggest that the trend in activity observed for these complexes is associated with the ease of phosphine arm dissociation.
Furthermore, the synthesis and characterization of a phosphine-substituted aryl diimine ligand, Ph2PPrADI-H was explored. Addition of Ph2PPrADI-H to CoCl2 resulted in C-H activation of the ligand backbone and formation of [(Ph2PPrADI)CoCl][Co2Cl6]0.5. Reduction of [(Ph2PPrADI)CoCl][Co2Cl6]0.5 afforded the precatalyst, (Ph2PPrADI)Co, that was found to effectively catalyze carbonyl hydrosilylation. At low catalyst loading, TOFs of up to 330 s-1 could be achieved, the highest ever reported for metal-catalyzed carbonyl hydrosilylation.
This dissertation also reports the first cobalt catalyzed pathway for dehydrocoupling diamines or polyamines with polymethylhydrosiloxanes to form crosslinked copolymers. At low catalyst loading, (Ph2PPrADI)Co was found to catalyze the dehydrocoupling of 1,3-diaminopropane and TMS-terminated PMHS with TOFs of up to 157 s-1, the highest TOF ever reported for a Si-N dehydrocoupling reaction. Dehydrocoupling of diamines with hydride-terminated polydimethylsiloxane yielded linear diamine siloxane copolymers as oils.
Finally, dehydrocoupling between diamines and organosilanes catalyzed by a manganese dimer complex, [(2,6-iPr2PhBDI)Mn(μ-H)]2, has allowed for the preparation of silane diamine copolymers. Exceptional solvent absorption capacity was demonstrated by the solid networks, which were found to absorb up to 7 times their own weight. Furthermore, degradation of these networks revealed that their Si-N backbones are easily hydrolysable when exposed to air. The use of lightly crosslinked copolymers as coatings was also studied using SEM analysis.
ContributorsSharma, Anuja (Author) / Trovitch, Ryan J. (Thesis advisor) / Seo, Dong-Kyun (Committee member) / Moore, Gary F. (Committee member) / Arizona State University (Publisher)
Created2024
Description
Amidst mounting global crises spanning environmental, social, and economic domains, sustainability education has emerged as a vital pathway toward a thriving future. However, despite its promise, the concept of sustainability often remains superficial, leaving educators ill-equipped to address its complexities. While efforts to integrate sustainability into education are underway, critical pedagogy, a crucial tool for fostering social change, is notably absent from instructional practices. This action research project utilized critical pedagogy to design and implement a critical professional development (CPD) workshop within a larger fellowship program to center justice within sustainability in both content and pedagogical approach. As a result, participants’ definitions and understandings of sustainability increased across all measurements of extent, breadth, and depth. Specifically, participants redefined collaborative relationships and more prominently included notions of justice and equity in their conceptualizations of sustainability and sustainability education. The use of critical pedagogy encouraged teachers to analyze intersectional oppressive systems and fostered a new, critical perspective on sustainability. In their own educational designs, participants demonstrated an intention to model elements of critical pedagogy, such as dialogic action and permeable content. Finally, in alignment with the intended outcomes of CPD, participants developed cooperative space for co-learning, built unity, shared leadership, and felt confident implementing their own professional development to address context-specific concerns. By using critical pedagogy in sustainability education, the workshop participants prioritized deep and caring relationships which fostered empathic engagement with the intersectional and often dehumanizing systems that have led to interconnected global crises. The results indicated that using CPD as a framework could be effective in teacher professional development for sustainability as a design and implementation tool to center critical work that examines systemic issues of injustice and exploitation against both humans and our planet.
ContributorsCashion, Molly Elise (Author) / Judson, Eugene (Thesis advisor) / Casanova, Carlos (Committee member) / Goebel, Janna (Committee member) / Boyce, Ayesha (Committee member) / Arizona State University (Publisher)
Created2024
Description
Engineering polymers are critical for contemporary high-performance applications where toughness, thermal stability, and density are at a premium. These materials often demand high-energy processing conditions or highly reactive monomers that hold negative impacts on human and environmental health. Thus, this work serves to remediate the negative impacts of engineering polymer synthesis by addressing toxicity and processing at the monomer level, while maintaining or exceeding previous thermomechanical and stimuli-responsive performance. Polyurethanes (PUs) represent a class of engineering polymers that possess highly modular properties due to the diverse monomer selection available for their synthesis. The efficient reaction between isocyanates and hydroxyls impart stellar properties and flexible processing modalities, however recent scrutiny regarding the toxicity of the isocyanate precursors has driven the search for non-isocyanate polyurethane (NIPU) pathways. The advancement of bis-carbonylimidazolide (BCI) monomers for the synthesis of NIPU thermoplastics and foams is thoroughly investigated in this work. Remarkably, a novel decarboxylation pathway for BCI monomers controlled by catalyst loading enabled in-situ CO2 generation during crosslinking with trifunctional amines, and resulted in a facile synthetic route for NIPU foams. Further explorations into catalyst considerations revealed Dabco® 33-LV as a suitable mechanism for controlling reaction times and careful selection of surfactant concentration provided control over pore size and geometry. This led to a library of flexible and rigid NIPU foams that displayed a wide range of thermomechanical properties. Furthermore, sequestration of the imidazole byproduct through an efficient Michael reaction identified maleimide and acrylate additives as a viable pathway to eliminate post-processing steps resulting in NIPU foam synthesis that is amenable to current industrial standards. This route held advantages over the isocyanate route, as condensate removal drove molecular weight increase and ultimately achieved the first reported phase separation behavior of a NIPU thermoplastic containing a poly(ethylene glycol) soft segment. Furthermore, sustainable considerations for engineering polymers were explored with the introduction of a novel cyclobutane bisimide monomer that readily installs into various polymeric systems. Direct installation of this monomer, CBDA-AP-I, into a polysulfone backbone enabled controlled photo-cleavage, while further hydroxy ethyl functionalization allowed for incorporation into PU systems for photo-cleavable high-performance adhesive applications.
ContributorsSintas, Jose Ignacio (Author) / Long, Timothy E (Thesis advisor) / Sample, Caitlin S. (Committee member) / Jin, Kailong (Committee member) / Arizona State University (Publisher)
Created2024
Description
Microplastics, plastics smaller than 5 mm, are an emerging concern worldwide due to their potential adverse effects on the environment and human health. Microplastics have the potential to biomagnify through the food chain, and are prone to adsorbing organic pollutants and heavy metals. Therefore, there is an urgent need to assess the extent of microplastic contamination in different environments. The occurrence of microplastics in the atmosphere of Tempe, AZ was investigated and results show concentrations as high as 1.1 microplastics/m3. The most abundant identified polymer was polyvinyl chloride. However, chemical characterization is fraught with challenges, with a majority of microplastics remaining chemically unidentified. Laboratory experiments simulating weathering of microplastics revealed that Raman spectra of microplastics change over time due to weathering processes. This work also studied the spatial variation of microplastics in soil in Phoenix and the surrounding areas of the Sonoran Desert, and microplastic abundances ranged from 122 to 1299 microplastics/kg with no clear trends between different locations, and substantial total deposition of microplastics occurring in the same location with resuspension and redistribution of deposited microplastics likely contributing to unclear spatial trends. Temporal variation of soil microplastics from 2005 to 2015 show a systematic increase in the abundance of microplastics. Polyethylene was prominent in all soil samples.
Further, recreational surface waters were investigated as a potential source of microplastics in aquatic environments. The temporal variation of microplastics in the Salt River, AZ over the course of one day depicted an increase of 8 times in microplastic concentration at peak activity time of 16:00 hr compared to 8:00 hr. Concurrently, microplastic concentrations in surface water samples from apartment community swimming pools in Tempe, AZ depicted substantial variability with concentrations as high as 254,574 MPs/m3. Polyester and Polyamide fibers were prevalent in surface water samples, indicating a release from synthetic fabrics. Finally, a method for distinguishing tire wear microplastics from soot in ambient aerosol samples was developed using Programmed Thermal Analysis, that allows for the quantification of Elemental Carbon. The method was successfully applied on urban aerosol samples with results depicting substantial fractions of tire wear in urban atmospheric environments.
ContributorsChandrakanthan, Kanchana (Author) / Herckes, Pierre (Thesis advisor) / Fraser, Matthew (Committee member) / Shock, Everett (Committee member) / Arizona State University (Publisher)
Created2024
Description
Words wield immense power. They help to shape realities, tell stories, and encompass deeper values and intentions on behalf of their users. Buzzwords are imprecise, trendy – and often-frustrating – words that are encountered in daily life. They frame problems, evoke emotional responses, and signal moral values. In this dissertation, I study buzzword use within the field of environmental conservation to better untangle the inherent tension they have long produced: do buzzwords help or hurt collective conservation efforts? Using a mixed methods approach, this dissertation provides descriptive and causal empirical evidence on many of the untested assumptions regarding the behavior, use, and impacts of buzzwords on conservation decision making. First, through a series of expert interviews with conservation professionals, I develop an empirically informed definition and understanding of buzzwords that builds upon the scholarly literature. It identifies eight defining characteristics, elaborates on the nuances of their use, life cycle, and context dependence, and sets forth a series of testable hypotheses on the relationship between buzzwords, trust, and perceptions. Second, I take this empirically informed understanding and employ a large-scale text analysis to interrogate the mainstream conservation discourse. I produce a list of buzzwords used across institutions (e.g., academia, NGOs) in the past five years and link them to predominant conservation frames, comparing the ways in which different institutions relate to and discuss conservation concepts. This analysis validates many long-held paradigms and ubiquitous buzzwords found in conservation such as sustainability and biodiversity, while identifying a more recently emerging framing of inclusive conservation. Third, I experimentally test a set of hypotheses on the effects that buzzwords have on decision making, as moderated through trust. This study finds evidence of a greenwashing effect, whereby buzzwords may produce marginal benefits to less trustworthy organizations through increases in credibility and group identity alignment, but do not outweigh the benefits of being trustworthy in the first place. In the face of many current global challenges requiring cooperation and collective action – such as climate change and environmental degradation – it is imperative to better understand the ways in which communication and framing (including buzzwords) influence decision making.
ContributorsClaborn, Kelly (Author) / Drummond Otten, Caitlin (Thesis advisor) / Janssen, Marcus A. (Thesis advisor) / Anderies, John M. (Committee member) / Carley, Kathleen M. (Committee member) / Arizona State University (Publisher)
Created2024