Matching Items (530)
Description
The story of graphene truly began in what was simply a stub in the journal Physical Review not two years after the end of World War II. In 1947, McGill University physicist P.R. Wallace authored “The Band Theory of Graphite” and attempted to develop a foundation on which the structure-property relationship of graphite could be explored; he calculates the number of free electrons and conductivity of what he describes as “a single hexagonal layer” and “suppos[es] that conduction takes place only in layers” in bulk graphite to predict wave functions, energies at specific atomic sites in the hexagonal lattice, and energy contours using a tight binding approximation for a hypothesized version of what we now call ‘armchair-style’ graphene. While Wallace was the first to explore the band structure and Brillouin Zones of single-layer graphite, the concept of two-dimensional materials was not new. In fact, for years, it was dismissed as a thermodynamic impossibility.
Everything seemed poised against any proposed physical and experimental stability of a structure like graphene. “Thermodynamically impossible”– a not uncommon shutdown to proposed novel physical or chemical concepts– was once used to describe the entire field of proposed two-dimensional crystals functioning separately from a three-dimensional base or crystalline structure. Rudolf Peierls and Lev Davoidovich Landau, both very accomplished physicists respectively known for the Manhattan Project and for developing a mathematical theory of helium superfluidity, rejected the possibility of isolated monolayer to few-layered crystal lattices. Their reasoning was that diverging thermodynamic-based crystal lattice fluctuations would render the material unstable regardless of controlled temperature. This logic is flawed, but not necessarily inaccurate– diamond, for instance, is thermodynamically metastable at room temperature and pressure in that there exists a slow (i.e. slow on the scale of millions of years) but continuous transformation to graphite. However, this logic was used to support an explanation of thermodynamic impossibility that was provided for graphene’s lack of isolation as late as 1979 by Cornell solid-state physicist Nathaniel David Mermin. These physicists’ claims had clear and consistent grounding in experimental data: as thin films become thinner, there exists a trend of a decreasing melting temperature and increasing instability that renders the films into islands at somewhere around ten to twenty atomic layers. This is driven by the thermodynamically-favorable minimization of surface energy.
Everything seemed poised against any proposed physical and experimental stability of a structure like graphene. “Thermodynamically impossible”– a not uncommon shutdown to proposed novel physical or chemical concepts– was once used to describe the entire field of proposed two-dimensional crystals functioning separately from a three-dimensional base or crystalline structure. Rudolf Peierls and Lev Davoidovich Landau, both very accomplished physicists respectively known for the Manhattan Project and for developing a mathematical theory of helium superfluidity, rejected the possibility of isolated monolayer to few-layered crystal lattices. Their reasoning was that diverging thermodynamic-based crystal lattice fluctuations would render the material unstable regardless of controlled temperature. This logic is flawed, but not necessarily inaccurate– diamond, for instance, is thermodynamically metastable at room temperature and pressure in that there exists a slow (i.e. slow on the scale of millions of years) but continuous transformation to graphite. However, this logic was used to support an explanation of thermodynamic impossibility that was provided for graphene’s lack of isolation as late as 1979 by Cornell solid-state physicist Nathaniel David Mermin. These physicists’ claims had clear and consistent grounding in experimental data: as thin films become thinner, there exists a trend of a decreasing melting temperature and increasing instability that renders the films into islands at somewhere around ten to twenty atomic layers. This is driven by the thermodynamically-favorable minimization of surface energy.
ContributorsShulman, Neal Arthur (Author) / Adams, James (Thesis director) / Islam, Rafiqul (Committee member) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Freshwater is an essential component of life for most organisms on earth. "Civilization itself is built on a foundation of water (Fagan, 2011)," as people often congregate near water sources, and find innovative solutions to exploit these resources for food production and domestic needs. Rising demand for water due to altered lifestyles and population increase pose further stress on water availability. Alterations and pollution of freshwater ecosystems can dramatically compromise ecological services that many species, among them humans, depend on. Arid places are specifically vulnerable in regards to water, characterized by very low levels of precipitation, as well as many dry months, which are often followed by a short time of severe storms. Considering the interconnectedness of social and ecological systems in regards to freshwater services is crucial in order to sustainably manage freshwater resources and avoid ecological crises that in turn are likely to lead to social crises around the globe (Berkes et. al., 2003).
ContributorsHenenson, Einav (Author) / Anderies, M. John (Thesis director) / Aggarwal, Rimjhim (Committee member) / Golub, Aaron (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor)
Created2012-12
Description
The efficiency of communication in the construction industry is crucial for the successful management of construction projects. Frontline Supervisors are construction professionals that have daily impact on physical construction. These supervisors have the unique challenge of managing various tasks, schedules, and people in order to complete their scope of work on time. With many methods of communication today, construction managers are searching for the most effective way to communicate with supervisors on all levels. This research project aims to study the quality of communication and quantity of communication methods among front line supervisors working on construction sites in Phoenix, Arizona. Findings may inform what types of communication, e.g., face-to-face individual conversations, in-person meeting, cell phone conversations, emails, etc., are most effective for frontline supervisors.
The results of this research paper will be used to aid general contractors in their communication decisions. This research will also serve as a jumping point for future research on construction communication. Researchers at Arizona State University will be able to use the information collected in this research paper to continue communication surveys in the Phoenix metro area. By continuing this project, researchers will be able to inform contractors to make decisions that benefit trade partners and contractors.
ContributorsBorgman, Harrison (Author) / Becker, Timothy (Thesis director) / Sullivan, Kenneth (Committee member) / Parrish, Kristen (Committee member) / Barrett, The Honors College (Contributor) / Del E. Webb Construction (Contributor)
Created2024-05
Description
Historically, young people have spearheaded environmental movements, demanding equitable involvement in decision-making processes that impact their future. Despite their active participation, barriers such as inadequate knowledge, lack of empowerment, and diminished hope often hinder meaningful engagement and impact. This study addresses these challenges by implementing a series of educational workshops designed to equip youth with the necessary tools to effectively influence climate policy and urban planning so that they can feel more hopeful about the future in the face of climate change. Utilizing both qualitative and quantitative methods, this research evaluates how different methods of arts-based educational engagement impact workshop participants' knowledge, empowerment, and optimism regarding their ability to inspire environmental change. The findings aim to contribute to the discourse on effective youth engagement in environmental justice, advocating for strategies that equip youth with the tools they need to foster sustainable community development and hope for the future.
ContributorsKarthikeyan, Amritha (Author) / Eakin, Hallie (Thesis director) / Pfeiffer, Deirdre (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor) / School of Art (Contributor) / School of Mathematical and Statistical Sciences (Contributor)
Created2024-05
Description
Nitrate (NO3-) pollution in surface and groundwater, worsened by nitrogen-rich fertilizers in agriculture, poses a significant challenge. Conventional methods remove NO3- physically, yielding concentrated reject water needing further treatment. Electrochemical processes use electrons to convert NO3- into ammonia (NH3) or dinitrogen (N2). This project explores photoelectrocatalysis, enhancing selectivity for NH3 as an added-value product using a photocathode based on tri-layers.
Titanium oxide (TiO2) nanorods modified with Ag and CuOx nanoparticles that exhibit high NO3- conversion rates and exceptional NH3 selectivity. Mechanism evaluation reveals additive effects between photocatalysis and electrocatalysis, surpassing individual performances. This approach offers promising solution for NO3- pollution remediation and sustainable resource recovery in agriculture.
ContributorsButzine, Noah (Author) / Garcia-Segura, Sergi (Thesis director) / Cerron-Calle, Gabriel (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainable Engineering & Built Envirnmt (Contributor) / School of Sustainability (Contributor)
Created2024-05
Description
As climate change accelerates worldwide, coastal communities face escalating threats, including sea level rise, saltwater intrusion, erosion, and flooding, jeopardizing their physical, economic, and cultural integrity. In the coastal community of Charlotteville, a non-profit organization called the Environmental Research Institute of Charlotteville (ERIC) is dedicated to creating a “mutually beneficial relationship between the coastal communities and ecosystems of North East Tobago”. Their work includes the training and staffing of Community-Based Field Technicians (CBFTs) - Charlotteville residents who have been trained by ERIC in their conservation work and practices and now work for the organization within their community. This research delves into the intricate relationship between cultural narratives and community resilience in Charlotteville, Tobago. Through targeted surveys of Charlotteville residents, ERIC, and CBFTs, this research explores how cultural traditions and conservation work can impact a community’s resilience to climate change. Initial findings suggest the profound significance of the sea to Charlotteville residents and potentially echo a collective desire to safeguard marine resources for future generations. Moreover, aligning conservation projects with immediate community needs and securing additional funding could potentially bolster resilience-building initiatives. The CBFTs emerge as a potentially crucial stakeholder, as survey data suggests that they facilitate communication, collaboration, and knowledge sharing between ERIC and the community. By beginning to illuminate the complex relationship between cultural heritage, environmental stewardship, and community resilience, this research offers potential insights for fostering resilience in coastal communities worldwide.
ContributorsValencia Neyra, Maria (Author) / Briggs, Georgette (Thesis director) / Martin, Thomas (Committee member) / Fanovich, Lanya (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainable Engineering & Built Envirnmt (Contributor) / School of Sustainability (Contributor)
Created2024-05
Description
Autism Spectrum Disorder (ASD) is a complex neurodevelopmental condition characterized by a wide range of symptoms and severities, affecting communication, behavior, and social interactions. With the prevalence of ASD rising to affect nearly 1 in 36 children in the United States, understanding and addressing the multifaceted needs of those with ASD is increasingly critical. This review explores the interplay between genetic, environmental, and immune factors in the onset of ASD, focusing on metabolic dysfunctions and the role of the gut-brain axis. Emerging research highlights the significance of abnormal metabolites and gut microbiota imbalances in contributing to the pathophysiology of ASD, suggesting that these factors may influence neurological function and behavior through modulating immune responses.
Recent analyses have uncovered metabolic disturbances in ASD, affecting amino acid metabolism, glutathione metabolism, glycolysis and the TCA cycle, homocysteine metabolism, ketone body synthesis, and lipid metabolism. These disturbances offer insights into how metabolic dysfunctions may contribute to the neurological and behavioral features of ASD. Furthermore, the gut microbiota's role in immune responses and the controversial impact of antibiotic use on gut flora composition is important to the complexity of ASD and the need for a nuanced understanding of treatment effects.
This review delves into the current understanding of metabolic dysfunctions in children with ASD, emphasizing the critical role of gut microbiota and the impact of antibiotic use. Specifically, this review discusses SCFAs, para-cresol, amino acid metabolites, and glutathione and their respective specific treatments. It also explores the potential of vitamin/mineral supplementation as a therapeutic strategy, highlighting significant improvements in metabolic markers and behavioral symptoms associated with ASD. The findings from key studies, including those by Adams et al., suggest that targeted nutritional interventions and careful management of gut health could offer promising avenues for improving the quality of life for individuals with ASD. The review also acknowledges the need for further research to confirm the long-term effects of these interventions and to develop personalized treatment approaches that consider the unique needs in individuals with ASD.
ContributorsNandakumar, Keshav (Author) / Adams, James (Thesis director) / Flynn, Christina (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor)
Created2024-05
Description
Sustainability has become an increasingly important field over the past few decades, especially in relation to the field of urban planning and development. Sustainable communities play a pivotal role in balancing residents' current and future needs while nurturing diversity within the community. Elements such as economic diversity, mixed land use, walkability, green spaces, varying age groups, and efficient resource and service provision cultivate sustainable communities that encourage residents to age in place. Urban planning is focused on promoting the presence of these elements in communities, but the process of turning them into reality is often difficult due to existing infrastructure, lack of resources, and failure to receive government approval. When communities fail to provide residents with the facilities necessary to foster sustainability, instability often follows as residents do not favor aging in place in communities that do not meet their current needs or will not meet their future needs. Accessory dwelling units have emerged as a strategy for encouraging and allowing aging in place to occur in the United States. Some states have legalized the development of these units to increase urban density and to provide affordable housing options in cities where residents might not be able to afford other options. Accessory dwelling units are a potential solution to address the housing affordability crisis in Hawaii by encouraging aging in place and supporting multigenerational families. Encouraging aging in place allows Hawaiian communities to become more sustainable by supporting multiple generations. Hawaii is one of the states that have legalized accessory dwelling units to address issues in the state housing market, which has provided the state with a new opportunity to experiment with an affordable housing solution that aligns with the state’s cultural values. The island state of Hawaii provides a unique opportunity to dissect the importance of sustainable communities and aging in place. Native Hawaiians place tremendous cultural emphasis on the family unit, which makes the state an excellent place to encourage sustainable design in communities to facilitate aging in place. Hawaii has struggled to develop sustainable communities historically with a growing tourism industry that provides significant revenue to the state government playing a large role in the state’s housing market. This has contributed to an unsustainable situation in Hawaii where it has become more difficult to age in place over time. Given this situation, this report will address the following research question:
What factors limit the ability of Hawaiians to “age in place” and how might accessory dwelling units help promote an environment of sustainable communities in Hawaii that fosters such aging in place?
To address this question, the existing literature will be utilized to highlight areas that promote housing affordability and aging in place as well as to highlight areas that are detrimental to aging in place across the state and at the county level. This thesis seeks to provide context for the factors that have prevented sustainable community development by conducting a literature review that encompasses the current state of housing development in Hawaii. Data from the University of Hawaii Economic Research Organization will be used to portray the current state of housing development in each Hawaiian county. My methods will examine how the state of Hawaii has previously utilized accessory dwelling units and discuss the potential for these developments given the statewide barriers Hawaiians face and the connection between Hawaiian culture and these units.
ContributorsStrydom, Dylan (Author) / Kelley, Jason (Thesis director) / Pfeiffer, Deirdre (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor)
Created2024-05
Description
Tempe City Roots is an upcoming music festival that aims to promote sustainability and community in the City of Tempe. Accessibility has been notably absent from the ideation process for this festival, despite being essential for a sustainable and community-oriented festival. Equity and justice are core to sustainability and disabled people are important members of the Tempe community. I have undergone a thorough research and ideation process to create nine accessibility-centered ideas for Tempe City Roots based on the thoughts and experiences of the disabled community. These ideas would make Tempe City Roots more accessible and inclusive for all, and allow each attendee to have a safe and enjoyable experience.
ContributorsColucci, Melody (Author) / Reeves, James Scott (Thesis director) / Kuhn, Anthony (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor) / School of International Letters and Cultures (Contributor)
Created2024-05
DescriptionSecondhand Saves repurposes donated clothes by giving them the new purpose of sustainability education through attaching embroidered patches made from recycled plastic.
ContributorsBullock, Jessica (Author) / Byrne, Jared (Thesis director) / Giles, Charles (Committee member) / Barrett, The Honors College (Contributor) / Graphic Information Technology (Contributor) / School of Sustainability (Contributor) / Hugh Downs School of Human Communication (Contributor)
Created2024-05