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Just Because They Say It: Does the U.S. Really Have the “First-Ever Comprehensive Framework” For Digital Assets?
Get PDFOn March 9, 2022, President Biden made history by signing an Executive Order on Ensuring Responsible Development of Digital Assets. On September 16, 2022, the White House released a fact sheet proclaiming that it had produced the “First Ever Comprehensive Framework for Responsible Development of Digital Assets,” based on nine reports stemming from the Executive Order. This Article is divided into two main parts. Part one reviews the reports received by the White House, explaining what they address while pointing out open issues for which no particular direction is established. Part two assesses regulatory gaps in the crypto space in order to make the case that we are far from a comprehensive approach to crypto (or digital assets, as they are sometimes called)
School Readiness Social Questions and Generalization to NET Using AAC Devices for Early Childhood Students with Autism
Get PDFThis study’s purpose was to provide intervention support with communication for participants on the autism spectrum between the ages of four and five years old before entering kindergarten using a handheld speech-generating device (SGD). With a multiple-baseline across-subjects approach, participants gained the skills to communicate their knowledge on kindergarten readiness questions whether verbally or through the assistance of a handheld speech-generating device (SGD) exposed to them during the intervention. This single-subject research study done during my internship taught school-readiness social questions to preschool students with autism with generalization to the natural environment teaching (NET). Using the natural environment teaching method allowed applied behavior analysis (ABA) practitioners to incorporate the learner\u27s natural environment into the teaching, development, and generalization of the skills. During my time completing the internship at the Sunshine School in Rogers, Arkansas we asked participants a variety of personal questions and colors to gauge their kindergarten readiness levels
Thermal Buffer Characterization of PCM on High Current SiC Solid-State Circuit Breakers
No full textThe expeditious implementation of electronic systems in confined spaces are continuing to decrease in size, this puts pressure on thermal management systems to follow this trend. This effect is amplified where peak power loss far exceeds average power loss. This leads to over spec’d thermal management system that is often greatly underutilized, PCM enhanced Heat Sinks provide a solution. They absorb excess heat during peak periods and release it when power loss returns to average levels. PCM heat sink will require less volume and material to deal with the extra power loss. PCM’s utilize the latent heat capacity when transitioning from a solid to a liquid to absorb energy without an increase in temperature. PCM enhanced heat sinks can decrease the maximum temperature achieved during transient power loss applications. This project primary objective aims to provide the University of Arkansas’s Power Switch Lab with a unique thermal solution utilizing phase changing material for a high current SiC SSCB. This thermal solution will help define the various effects of implementing a thermal buffer during transient power loss conditions. The current thermal solution is a direct metal laser sintered heat sink made of an aluminum composite, AlSi10Mg. This hybrid heat sink attaches directly to the SiC SSCB via machine screws. The thermal solution also comes equipped with a fan that connects to the heat sink, to provide a solid thermal solution with zero moving parts. The phase changing material is sealed within a cavity using a breather vent that allows air the chamber pressure to reach equilibrium with the outside atmosphere while keeping the liquid PCM confined. This thesis aims to present a detailed procedural outline encompassing the design, manufacturing, and testing phases, as well to investigates the viability of Phase Change Materials (PCMs) as a solution for Solid State Circuit Breaker (SSCB) and prospective cooling applications
Towards Sustainable Architecture: Exploring the Potential for Mold Making in Cob Building
Get PDFWith the call for sustainable design appearing to be on the rise in recent decades, cob can offer a unique solution for creating sturdy, long-lasting, environmentally friendly, and moldable homes. With the need for sustainability in architecture and construction becoming more evident, a return to well-documented ancient building practices that have proven to stand the test could create a unique solution for some wanting to find an alternative to modern construction and design. Traditionally a method of construction lacking an architect’s input and seen as a pure vernacular form of architecture, could added awareness and the ability to create more unique surface patterns renew interest in cob the same way earth ships and adobe have gained popularity in North America today? Through a series of tests to determine cob mixing rations, the creation of detailed wooden molds, and experimentation with surface qualities, this study aims to examine if molds could be utilized to bring cob into the 21st century. Intended to be a jumping-off point for further research, this study provides scholarly resources, historical information, and test results for those interested in continuing to test the limits of cob design
Labeling Energy Drinks: Tackling a Monster of a Problem
Get PDFEnergy drinks first rose to popularity in the 1980s after the creation of Red Bull. In addition to high caffeine amounts, energy drinks often contain herbal stimulant additives, vitamin and mineral mixtures, and sugar. There is very little information available on the long-term effects of these stimulant mixtures on the body. Although many consumers purchase energy drinks because of their caffeine content, many are left in the dark when it comes to labeling transparency and are unaware of their true contents. Energy drinks are classified as dietary supplements, meaning they are not directly regulated by the FDA before hitting store shelves. Instead, energy drink labels follow the Dietary Supplement Health and Education Act (DSHEA) guidelines. Under DSHEA, energy drinks face lax labeling regulations, which leaves consumers unaware of the dangers of high caffeine contents, stimulative additives, proprietary blends, and excessive sugar. We will discuss the dangers of energy drinks, the current regulatory framework and the problems it causes, why these problems should be corrected, and potential policy changes to fix those problems
Leveraging Machine Learning and Stochastic Programming to Address Vaccine Hesitancy in Public Health Resource Allocation
Get PDFInfectious disease outbreaks highlight the urgent need for effective strategies to distribute vaccines and allocate critical healthcare resources to contain the disease and reduce its negative impacts on the population. Managing these allocations is a significant challenge, especially in marginalized communities facing uncertainty in healthcare demand and logistical constraints. This dissertation addresses these challenges by investigating factors that influence dynamic changes in vaccine hesitancy (VH) and its implications for disease spread and healthcare resource demand. It develops optimization models for vaccine distribution and resource allocation under uncertainty, validated with data from the COVID-19 pandemic in the U.S. The first study uses machine learning (ML) models to identify key factors influencing VH at the county level, considering both static (e.g., demographics) and dynamic (e.g., social media sentiment) factors. A metric, VHb, is proposed to track changes in VH behavior over time. Data from between January and October 2021 is used to build and validate this metric. The goodness of variance fit method identifies five distinct county clusters based on VHb. The ML (i.e., Random Forest) model indicates that factors like Google search trends and political affiliation can effectively predict VH trends at the county level. These results reveal that strict vaccination policies can be effective in increasing vaccination rates in counties with low resistance to vaccines. Furthermore, the results reveal significant variation in VH across the U.S., complicating decisions about resource allocation. This motivates the subsequent studies to enhance allocation strategies under stochastic VH trends. The second study proposes a compartmental multi-stage stochastic programming (MSP) model to optimize the allocation of scarce healthcare resources (e.g., ventilators) during a pandemic. The model captures the impact of stochastic VH on disease spread and the need for critical resources. This compartmental model simulates dynamic changes in the population in response to VH over time and space, enhancing the ability of the MSP to adapt resource allocation strategies to the evolving spread of disease and population behavior. Our numerical analysis highlights the significant impact of resource deployment timing and size on managing disease spread and mortality rates. The results emphasize the importance of advanced planning, effective management of critical resources, and balancing equity and effectiveness in resource allocation. The timing of vaccination plays a crucial role in the stochastic behavior of VH. The third study improves the previous compartmental MSP model to optimize vaccine allocation, aiming to better understand the impact of vaccination strategies on VH. The model accounts for how the timing of vaccination influences VH behavior over time and determines optimal vaccination sequences for different population groups. Various prioritization strategies were analyzed to understand their impact on reducing deaths and infections. The study finds that flexible and adaptive strategies, such as the Available-for-All vaccination policy, are key to minimizing deaths and infections. Early vaccination of groups with high transmission rate, rather than strictly prioritizing by age or occupation, can significantly enhance public health outcomes. The findings and methodologies presented in this dissertation offer robust tools for managing VH and optimizing resource allocation during health crises, ultimately improving public health outcomes during future pandemics and health emergencies
Assessing Consumer Willingness to Pay for Zinc-Biofortified Rice – the Case of Colombia
Get PDFHidden hunger, a form of undernourishment caused by micronutrient deficiencies, remains a critical global challenge affecting billions worldwide. Biofortification of staple crops, such as rice, offers a promising solution to address this problem. However, changes in the physical and culinary characteristics due to biofortification may hinder consumer acceptance and limit the benefits of this approach. This research explores consumer preferences and willingness to pay (WTP) for zinc-biofortified rice in Cartagena, Colombia. A non-hypothetical experimental auction, including 400 consumers in five different locations within Cartagena, was conducted to analyze the impact of information, socioeconomic factors, and consumer nutrition knowledge on WTP for zinc-biofortified rice. The results indicate that zinc-biofortified rice is priced as a premium-quality rice relative to other rice market alternatives, highlighting that the high zinc content did not affect the sensory characteristics of the rice. The information treatment about either the “Benefits of zinc-biofortified rice” or the “Problems of zinc deficiency” had a positive impact on the WTP for zinc-biofortified rice, which was reinforced by participants\u27 nutrition knowledge. These findings provide valuable insights for policymakers and stakeholders aiming to address malnutrition effectively, as well as retail companies hoping to market biofortified staple crops to vulnerable populations
A 10 kV SiC MOSFET Power Module with Optimized System Interface and Electric Field Distribution
No full textThis dissertation introduces a holistic and systematic design methodology tailored to the 10 kV silicon carbide (SiC) MOSFET power modules to achieve multi-objective optimization with enhanced electric-field (E-field) distribution, minimized common-mode (CM) parasitic capacitance, and reduced system-level parasitic inductances. The proposed approach encompasses two innovative techniques: 1) an electric-potential-oriented module-system interface to reduce system-level parasitic inductance while maximizing insulation capability; 2) stacked substrates with patterned middle layer copper to alleviate the E-field concentration at the triple-point and reduce the maximum E-field without compromising on thermal resistance. The effectiveness of these innovative approaches is substantiated through the development of a 10 kV SiC MOSFET power module. Experimental validation showcases its robust voltage insulation capability with 0.87 µA leakage current at 10 kV, a 33 kV DC and 25 kV AC surface flashover for worst-case system fault conditions, a well-balanced 5.6 nH power loop inductance with embedded decoupling capacitors, a record-low 28 pF common mode (CM) parasitic capacitance, owing to the middle layer pattern structure, as well as a 38.6% E-filed concentration reduction at the triple-point. The partial discharge inception voltage (PDIV) of the proposed middle layer patterned stacked substrates is verified at 16.8 kVrms. Dynamic performance validation through a double-pulse test at 5 kV showcases negligible ringing and voltage overshot. All these exceptional attributes position the packaged 10 kV SiC MOSFET power module as an exemplary choice for MV power electronics applications
An Investigation of the Effect of Performance Engineered Mixture (PEM) Design on Durability and Air Void Matrix of Concrete Pavements
Get PDFPerformance Engineered Mixture (PEM) design is a novel method of creating concrete pavement that is economical achieving desirable performance properties such as durability, strength, and workability. Performance-based design is critical for concrete pavements, so the fresh concrete can be placed without issue and the hardened concrete can withstand deterioration and environmental damage such as freezing and thawing. To achieve economical concrete, PEM utilizes tools such as the tarantula curve for aggregate grading, and the Super Air Meter (SAM) test, providing information regarding the air void matrix while the concrete is fresh. To achieve these properties with less cement will lead to decreased material costs, decreased concrete carbon footprint, and decreased durability issues associated with the cement paste. In this study, seven mixtures were developed. Two with aggregate gradations, followed by the same two mixtures with fly ash replacement of cement. A “truly” optimized aggregate mixture with fly ash replacement of cement. And finally, two mixtures with increased air contents. There was a mixture with solely #57 aggregate, a mixture with a blend of #57 and #7 aggregate, a “truly” optimized mixture whose combined gradation is nearly centered on the tarantula curve, and an additional #57 mixture and “truly” optimized mixture with an increased air content to correlate a good SAM number and spacing factor. Each mixture was evaluated by collecting a SAM number, ASTM C666 freeze/thaw test prisms, and a prism to conduct ASTM C457 spacing factor analysis. It was found that cement content in portland cement concrete pavement (PCCP) could be reduced to 440 pounds per cubic yard while maintaining strength, workability, and air content requirements. Aggregate composition in some mixtures had an undesirable effect on freeze/thaw resistance of the mixtures, with permeable or lightweight aggregates performing poorly. Spacing factor data was inconclusive, due to issues concerning the polishing procedure that were encountered during analysis
Desire Lines: Reading Queerly Through the Forests of Medieval Love Literature
Get PDFThis dissertation conducts queer eco-sensitive readings of a selection of medieval love texts in Middle English and Old French. Informed in turns by the works of feminist, queer, and ecocritical scholars, each chapter engages with a different iteration of literary queerness by bringing the representation of natural spaces and objects (especially the forest) to the fore and reading through nature depicted in the texts. The readings all share a broad goal of inviting modern audiences to play with desire and its manifestations within each text to make meaning and compel intimacy between the work and its current audience. Chapter 1 argues that the Middle English Amis and Amiloun queers genre, and the forest acts as a haven for the two titular protagonists to engage in homoerotic gender parody play. Drawing on queer touchstones from other premodern and early modern narratives, I assert that the friendship between Amis and Amiloun teems with homoerotic overtones corresponding to the other characters in their story. Chapter 2 explores the Middle English lyric’s tendency to queer women into nature objects. I argue that such naturalizing begins as poetic metaphor when courtly suitors attempt to seduce women at court, but it eventually dehumanizes women and weaponizes natural-world discourse against them when they are in unprotected, unsupervised, and isolated spaces. Finally, I propose that in some lyrics, queered young women reclaim their diminished humanity to resist and survive the sexual encounters they are subjected to. Chapter 3 proposes an alternative framework for power modelled by the Old French Yvain, ou le chevalier au lion. Working closely with Donna Haraway’s ideas on kinship during the chthulucene, I decenter the knight Yvain to reveal the depth of connectivity among the constellation of characters in the tale named for a single knight. Finally, Chapter 4 draws attention to the villain of Le Roman de Silence, a 13th century French tale mostly known because of its girl-knight who is raised as a boy. I argue that Queen Eufeme is a queer-coded villain who is, in fact, more transgressive in her sexuality and gender performativity than the girl-knight Silence, and with the help of Elizabeth Jane Burns’s thorough work on the queering of fabliaux women, I construe Queen Eufeme as a genre-queer fabliau woman trapped in the role of a courtly lady. Working with the vast but relatively novel body of queer-medieval scholarship, I draw out the natural world as a focal place of meaning, more significant than its role as mere setting suggests. Partly an effort to trouble the persistence of binaries (male-female, Subject-object, human-nature, self-Other) in feminist and queer readings of medieval courtly love texts, each chapter shifts its gaze to a different possibility for queerness in the medieval, purposefully refusing to land on certainty and dedicated to relishing the perplexity of desire and its many faces in medieval love