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- All Subjects: Materials Science
- All Subjects: Sustainability
- Creators: Arizona State University
- Status: Published
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
The Intercoupling of Thermal Transport and Mechanical Properties in Colloidal Nanocrystal Assemblies
Description
Colloidal nanocrystals (NCs) are promising candidates for a wide range of applications (electronics, optoelectronics, photovoltaics, thermoelectrics, etc.). Mechanical and thermal transport property play very important roles in all of these applications. On one hand, mechanical robustness and high thermal conductivity are desired in electronics, optoelectronics, and photovoltaics. This improves thermomechanical stability and minimizes the temperature rise during the device operation. On the other hand, low thermal conductivity is desired for higher thermoelectric figure of merit (ZT). This dissertation demonstrates that ligand structure and nanocrystal ordering are the primary determining factors for thermal transport and mechanical properties in colloidal nanocrystal assemblies. To eliminate the mechanics and thermal transport barrier, I first propose a ligand crosslinking method to improve the thermal transport across the ligand-ligand interface and thus increasing the overall thermal conductivity of NC assemblies. Young’s modulus of nanocrystal solids also increases simultaneously upon ligand crosslinking. My thermal transport measurements show that the thermal conductivity of the iron oxide NC solids increases by a factor of 2-3 upon ligand crosslinking. Further, I demonstrate that, though with same composition, long-range ordered nanocrystal superlattices possess higher mechanical and thermal transport properties than disordered nanocrystal thin films. Experimental measurements along with theoretical modeling indicate that stronger ligand-ligand interaction in NC superlattice accounts for the improved mechanics and thermal transport. This suggests that NC/ligand arranging order also plays important roles in determining mechanics and thermal transport properties of NC assemblies. Lastly, I show that inorganic ligand functionalization could lead to tremendous mechanical enhancement (a factor of ~60) in NC solids. After ligand exchange and drying, the short inorganic Sn2S64- ligands dissociate into a few atomic layers of amorphous SnS2 at room temperature and interconnects the neighboring NCs. I observe a reverse Hall-Petch relation as the size of NC decreases. Both atomistic simulations and analytical phase mixture modeling identify the grain boundaries and their activities as the mechanic bottleneck.
ContributorsWang, Zhongyong (Author) / Wang, Robert RW (Thesis advisor) / Wang, Liping LW (Committee member) / Newman, Nathan NN (Committee member) / Arizona State University (Publisher)
Created2021
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
Over the past few years, research into the use of doped diamond in electronics has seen an exponential growth. In the course of finding ways to reduce the contact resistivity, nanocarbon materials have been an interesting focus. In this work, the transfer length method (TLM) was used to investigate Ohmic contact properties using the tri-layer stack Ti/Pt/Au on nitrogen-doped n-type conducting nano-carbon (nanoC) layers grown on (100) diamond substrates. The nanocarbon material was characterized using Secondary Ion Mass Spectrometry (SIMS), Scanning electron Microscopy (SEM) X-ray diffraction (XRD), Raman scattering and Hall effect measurements to probe the materials characteristics. Room temperature electrical measurements were taken, and samples were annealed to observe changes in electrical conductivity. Low specific contact resistivity values of 8 x 10^-5 Ωcm^2 were achieved, which was almost two orders of magnitude lower than previously reported values. The results were attributed to the increased nitrogen incorporation, and the presence of electrically active defects which leads to an increase in conduction in the nanocarbon. Further a study of light phosphorus doped layers using similar methods with Ti/Pt/Au contacts again yielded a low contact resistivity of about 9.88 x 10^-2 Ωcm^2 which is an interesting prospect among lightly doped diamond films for applications in devices such as transistors. In addition, for the first time, hafnium was substituted for Ti in the contact stack (Hf/Pt/Au) and studied on nitrogen doped nanocarbon films, which resulted in low contact resistivity values on the order of 10^-2 Ωcm^2. The implications of the results were discussed, and recommendations for improving the experimental process was outlined. Lastly, a method for the selective area growth of nanocarbon was developed and studied and the results provided an insight into how different characterizations can be used to confirm the presence of the nanocrystalline diamond material, the limitations due to the film thickness was explored and ideas for future work was proposed.
ContributorsAmonoo, Evangeline Abena (Author) / Thornton, Trevor (Thesis advisor) / Alford, Terry L (Thesis advisor) / Anwar, Shahriar (Committee member) / Theodore, David (Committee member) / Arizona State University (Publisher)
Created2023
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
Integrating advanced materials with innovative manufacturing techniques has propelled the field of additive manufacturing into new frontiers. This study explores the rapid 3D printing of reduced graphene oxide/polymer composites using Micro-Continuous Liquid Interface Production (μCLIP), a cutting-edge technology known for its speed and precision. A printable ink is formulated with reduced graphene oxide for μCLIP-based 3D printing. The research focuses on optimizing μCLIP parameters to fabricate reduced graphene composites efficiently. The study encompasses material synthesis, ink formulation and explores the resulting material's structural and electrical properties. The marriage of graphene's unique attributes with the rapid prototyping capabilities of μCLIP opens new avenues for scalable and rapid production in applications such as energy storage, sensors, and lightweight structural components. This work contributes to the evolving landscape of advanced materials and additive manufacturing, offering insights into the synthesis, characterization, and potential applications of 3D printed reduced graphene oxide/polymercomposites.
ContributorsRavishankar, Chayaank Bangalore (Author) / Chen, Xiangfan (Thesis advisor) / Bhate, Dhruv (Committee member) / Azeredo, Bruno (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
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