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Tough Sell: Rising Powers, Domestic Legitimation and Costly International Initiatives
No full textRising powers sometimes pursue foreign policy initiatives that are costly and burdensome. While such initiatives may serve strategic or ideational purposes on the global stage, they must also be legitimized, specifically by receiving sufficient political support at home. This dissertation examines why some of these costly international initiatives succeed in garnering domestic support, while others struggle or fail. It focuses on “tough sell” initiatives that offer limited short-term material benefits to justify to domestic audiences.Building on theories of domestic legitimation, this study advances a framework of ideational legitimation strategies, emphasizing the central role of national narratives. It argues that leaders use culturally resonant narratives—rooted in national identity, historical memory, and ethical norms—to justify costly initiatives to their domestic publics. These narratives shape how such policies are received by elites, the public, and the media. The success of legitimation, however, depends how well the narrative resonates with the target audience, especially under conditions of crisis, ambiguity, or uncertainty.
To explain variation in outcomes, this dissertation disaggregates domestic legitimation into three ideal types: approval, quiescent acceptance, and disapproval. It proposes that resonance with dominant identity narratives, emotional alignment, and timing—particularly during crises—can lead to greater acceptance or even support for costly initiatives that might otherwise provoke opposition.
The study employs a comparative case study method, analyzing four costly international initiatives across two rising powers—China and India—through extensive content analysis of political speeches and media coverage, as well as elite interviews. The cases include: (1) China’s stance at the Copenhagen and Paris climate summits, (2) India’s Vaccine Maitri initiative during the COVID-19 pandemic, and (3) the 2008 Beijing Olympics and 2010 Delhi Commonwealth Games. These cases vary in outcomes and regime types but are united by their high-cost nature.
This project contributes to the study of rising powers, foreign policy legitimation, and the role of narratives in world politics. It challenges the notion that regime type alone explains domestic support for costly policies and instead highlights how narrative construction, especially when tied to identity, can overcome the barriers of domestic skepticism. It offers both theoretical and empirical insights for scholars of international relations and practitioners interested in the domestic foundations of global initiatives
Synthesis and Characterization of Methylammonium Strontium Bromide Hybrid Perovskite
No full textIn this thesis, we synthesized and investigated the properties of a Sr-containing hybrid perovskite, methylammonium strontium bromide (MASrBr3). We report on the preparation of MASrBr3 thin films and studied the effects of annealing temperature, annealing time, and precursor solution concentration on crystal growth using XRD and UV-Vis spectroscopy. The composition and crystalline nature of the MASrBr3 thin film were further confirmed using XRD and SEM-EDX. We explored the stability of the MASrBr3 thin films in three solvents and the electrochemical stability of MASrBr3 in an ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. From this study, we observed that MASrBr3 was stable from -1.75 V to 0.35 V vs. Fc/Fc+. Lastly, we determined that the MASrBr3 thin films possess an indirect band gap of 4.52 eV which is corroborated by density functional theory calculations. Taken together, these results indicate that the synthesized MASrBr3 perovskite is viable for future high-bandgap device applications
Using sEMG to investigate muscle activation during a graded exercise test while sustaining SRC
No full textSport-related concussions (SRCs) are common injuries among athletes, often resulting in cognitive, emotional, and physical impairments that can extend beyond the acute phase of injury. While SRCs are known to disrupt neuromuscular function and increase the risk of lower extremity (LE) injuries, limited research has explored the impact of SRCs on muscle activation patterns during exercise. This study aimed to investigate differences in normalized LE muscle activity in collegiate athletes with SRC during the acute phase of injury compared to their symptom-free state. Surface electromyography (sEMG) was integrated with the Buffalo Concussion Treadmill Test (BCTT) to assess muscle activation under controlled exercise conditions. A repeated-measures design was employed, with participants completing sEMG assessments during BCTT at two time points: within 48 hours of injury and after being symptom-free for at least 24 hours. Statistical analyses examined changes in LE muscle activity across conditions. Preliminary findings suggest that SRC alters neuromuscular control of the erector spinae. This muscle had significantly less muscle activation throughout the BCTT than the LE muscles, but higher gradual changes from the first minute to the last minute of the BCTT completed, potentially contributing to impaired postural stability and increased injury risk. These results underscore the importance of incorporating neuromuscular assessments into SRC rehabilitation protocols. This study provides novel insights into the physiological effects of SRC on muscle activation and highlights the potential utility of sEMG as a diagnostic and rehabilitation tool. Future research should explore larger samples and investigate how targeted interventions can mitigate neuromuscular deficits and reduce recovery time for athletes with SRC
Robust and Efficient AI-models for Medical Image Reconstruction, Segmentation, and Multimodal Knowledge Distillation
No full textArtificial intelligence (AI) is transforming the healthcare landscape, offering the promise of earlier diagnoses, more personalized treatments, and improved patient outcomes. However, despite its tremendous potential, deploying AI in real-world clinical settings remains fraught with challenges. Models must operate reliably with limited annotated data, generalize across diverse imaging modalities and patient populations, function efficiently within computationally constrained environments, and remain robust against noise and adversarial perturbations. Overcoming these barriers requires moving beyond narrowly data-driven systems toward AI frameworks that are both technically sophisticated and broadly adaptable to the complexity of clinical practice. This dissertation introduces a cohesive set of AI-driven methodologies designed to meet these demands. At the center of this work is the development of strategies for medical image reconstruction, semantic segmentation, multimodal knowledge integration, and adversarial robustness. I propose Teach-Former, a multi-teacher knowledge distillation framework that enables lightweight models to absorb rich spatial and contextual representations from multiple large networks, achieving efficient and accurate segmentation across multimodal medical images. To address the limitations of low-resolution imaging, particularly in resource-constrained environments such as spaceflight medicine, I introduce Swin-FSR, a Swin Transformer-based super-resolution model that reconstructs high-fidelity fundus images while preserving fine anatomical detail. Recognizing the importance of volumetric imaging, I further developed SwinVFTR, a transformer architecture capable of segmenting irregular fluid accumulations in 3D optical coherence tomography (OCT) volumes with enhanced precision. Beyond imaging tasks, I tackle the vulnerability of physiological signal analysis through the design of ECG-Adv-GAN and ECG-ATK-GAN, conditional generative adversarial networks that generate realistic adversarial examples and fortify the robustness of ECG arrhythmia classification models. To frame these efforts within a broader security perspective, we developed a game-theoretical framework that models adversarial interactions between attackers and defenders, offering a principled approach to designing robust machine learning systems. Extensive evaluations across diverse, real-world datasets validate the effectiveness of the proposed approaches, demonstrating improvements in segmentation accuracy, super resolution quality, adversarial defense, and computational efficiency compared to state-of-the-art baselines. Importantly, the models presented here are not confined to data-driven optimization within medical imaging alone. By focusing on generalizable learning strategies such as knowledge transfer, multimodal integration, and robustness against uncertainty, this work lays a foundation for adapting AI solutions to other domains where data is limited, interpretability is essential, and robustness against uncertainty is crucial. Overall, the contributions of this dissertation move us closer to building safe, scalable, and trustworthy AI systems capable of making a meaningful impact across a wide range of scientific and societal challenges
Mid-Atlantic Peer Exchange on Balanced Mix Design (BMD)
No full textSeven States from the Mid-Atlantic U.S. and the District of Columbia (the District) gathered for a peer exchange and discussion on implementation activities to support Balanced Mix Design (BMD). The peer exchange was sponsored by the Federal Highway Administration (FHWA). The seven States and the District met to assess the state-of-practice for the technology, tools, and techniques in designing, verifying, and accepting asphalt mixtures for different layers within the flexible pavement structure, as well as for overlays of different pavements following BMD emerging practices. The peer exchange was held in Washington, D.C. This summary report focuses on agency motivations for considering BMD, implementation challenges, key takeaways, and emerging themes.United States Department of TransportationFederal Highway Administratio
The Lab is Wild: Navigating Human-Robot Interaction as a Socio-Spatial Practice in the Design Environment
No full textThis thesis reframes the study of human-robot interaction (HRI) by turning ethnographic attention toward the design environment itself. While HRI research often centers on end-users and robots “in the wild,” this study focuses on the engineers as creators, arguing that the lab is not a neutral backdrop, but rather a dynamic, relational space where the social dimensions of robotics are actively shaped. Drawing on nearly four years of participant-observation within the Socially Assistive Robotics Group (SARG) at the University of Nevada, Reno, this research examines how interdisciplinary collaborators—faculty, staff, and students—navigate the social, spatial, and technical entanglements of building a socially interactive museum tour guide robot. Through attention to collaboration, friction, failure, and informal practices—such as coffee rituals, shared workspaces, and spatial improvisation—it reveals how the design process is influenced by more than technical objectives: it is shaped by institutional structures, embodied labor, and narratives about robotics’ futures. Guided by socio-spatial theory from human geography and critical robotics studies, the thesis conceptualizes HRI as a socio-spatial practice—emerging not only in public interactions, but through the iterative, affectively charged labor of robot design. Ethnography, participant-observation, and rhetorical analysis are used to examine how space, labor, and language co-construct the possibilities of social robotics. By reframing the human actor as designer rather than user, this study provides new insights into HRI, foregrounding the socio-technical processes that underpin robotic development. It argues that understanding robots as social agents requires understanding the social conditions of their making—and that the lab, with its disorder and improvisation, is itself a wild and generative space. The thesis highlights the design environment’s crucial role in shaping both robotic technologies and the narratives that frame their integration into human-centered settings
Cyclic Iodine Loading and Regeneration of Silver-Loaded Engineered Zeolites for Off-Gas Treatment Applications
No full textAqueous reprocessing of used nuclear fuel results in the release of gaseous radioiodine. Silver-exchanged zeolites have long been considered effective sorbents for the capture of radioiodine from off-gas streams. Although regeneration and reuse of these costly, yet effective, sorbents were explored decades ago by the Department of Energy (DOE), the approach was likely abandoned due to poor performance during subsequent capture and regeneration cycles. In this study, loading and regeneration cycles were performed on two different sorbents to understand the properties that lead to regeneration longevity: silver-exchanged faujasite (Ag-400) with 37 mass% silver and silver-containing mordenite (Nex) with 10 mass% silver. The sorbents were in the form of engineered beads or extrudates; however, no binder material was identified. Pure silver wire (Ag) was also evaluated to understand the reactions between silver and iodine without the influence of an additional sorbent substrate. Cyclic testing was conducted by exposing sorbents to a saturated I2(g) environment at 150°C to form AgI(s), followed by regeneration at 500°C using H2(g) to strip iodine as HI(g). Ag-400 showed degradation after initial iodine loading, resulting in increased capture performance during the second cycle due to more exposure of previously inaccessible silver sites. However, the capture performance is unclear as full regeneration of the sample did not occur after the second loading cycle. Nex exhibited no visible structural changes, nor any decline in capture performance, after 5 cycles. Silver wire had limited iodine penetration of 60 µm after 18 h and AgI(s) formation during saturation testing with an 8 µm h-1 AgI(s) transformation rate that slowed down as exposure time increased. Regeneration of fully transformed wire with 18 h regeneration
time failed, only reducing a thin shell of the wire back to Ag0(s) with varying thickness between 10-30 µm. Although unsuccessful, these observations offered insight into how slow regeneration kinetic rates were and how this led to the failed regeneration of larger silver particles later observed in the Ag-400 cyclic testing. Ag-400 has silver ions uniformly distributed throughout the material. The structural degradation of Ag-400 is attributed to a combination of AgI(s) formation upon loading and reduction of Ag+ to Ag0 during regeneration, the effects of which are exacerbated due to the high silver loading. The X-ray diffraction (XRD) patterns showed amorphization of the faujasite (FAU) framework by the first cycle of regeneration. The removal of Ag+ from its framework-stabilizing position and subsequent precipitation as AgI(s) initiates the collapse of the FAU structure. Upon regeneration, the release of iodine as HI(g) is accompanied by the reduction of silver, which subsequently aggregates to form metallic particles of 0.5-4 µm. Further cycles lead to repeated aggregation and particle growth, resulting in silver- rich particles of 5-25 µm. Nex is comprised of 400-700 nm Ag-containing particles forming large clusters of 10-25 µm, and silver uniformly distributed throughout an unidentified mordenite (MOR) matrix. Changes in the silver distribution and particle morphology were observed with cycling- silver clusters aggregate into AgI(s) particles of a similar size as the whole clusters that, upon regeneration, separate and redistribute as smaller, 1-2 µm reduced metallic particles that do not sinter or aggregate further, which repeats upon subsequent cycles. MOR regions without the silver clusters experience small-scale aggregation of the uniformly distributed silver into sub-micron (400-700 nm) particles throughout the bulk upon initial loading and regeneration, but do not aggregate further upon additional cycles.
The absence of bulk structural changes indicates that the compliant matrix and low silver content were suitable to accommodate the volumetric stresses induced by repeated loading and regeneration. Despite the significant difference in silver concentration, the Ag-400 and Nex had similar iodine loading levels of 448 and 324 mg g-1, respectively. Based on these results, sorbents with silver loading and forms that minimize mechanical disruption of the substrate at the bulk scale are expected to perform better under regeneration conditions. Although the sorbents used in this study differ somewhat from those evaluated in the original DOE regeneration tests, similar trends were observed with MOR-based sorbents overperforming the FAU-based counterpart. It remains unclear whether FAU would undergo the same degree of structural collapse at lower silver exchange levels similar to the MOR. However, the excess negative charge associated with the high aluminum content in low Si/Al FAU (X) reduces framework stability, particularly in acidic environments and elevated temperatures. The ease of migration and growth of the silver particles through the bulk upon regeneration leads to the structural collapse of the engineered pellet. In contrast, the higher Si/Al of the MOR (Z) is less reliant on cation stabilization and exhibits improved thermal stability. Prolonged cycling would be required to determine whether embedded silver particles eventually lead to structural damage in the sorbent matrix, but even in the absence of regeneration, MOR would make a better choice than FAU for iodine capture in extreme environments
Multiwavelength Signatures of Super-Eddington Accretion in Active Galactic Nuclei
No full textQuasars are present at high redshift, suggesting that some supermassive black holes grew quickly through accretion and/or mergers soon after the Big Bang. Growth through accretion likely required episodes exceeding the Eddington limit. To improve our understanding of how efficiently seed black holes can be fed, we need better constraints on the observational characteristics of near/super-Eddington accretion in active galactic nuclei (AGNs) -- particularly changes to the structure and radiative output of the central engine. Accretion disks in the standard AGN model are geometrically thin and radiatively efficient at low-to-moderate accretion rates, but above near-Eddington rates the disk may inflate at small radii, becoming a geometrically thick and radiatively inefficient "slim" disk. This change facilitates a transition to super-Eddington accretion, and it undoubtedly impacts the appearance and radiative output of the AGN central engine and its surrounding regions, necessitating multiwavelength studies. I performed tests using new and archival observations across radio, optical, ultraviolet, and X-ray bands, from which I find support for the slim-disk accretion state in samples of both supermassive and low-mass AGNs. First, I used optical, ultraviolet, and X-ray observations to examine a sample of quasars with unusually weak broad emission lines, and I found that their emission-line weakness may result from a slim disk shielding the broad emission-line region gas from ionizing radiation. Next, I used radio and X-ray observations to examine a sample of low-mass AGNs that display a puzzling trend toward unusual X-ray weakness, which I found may result from a slim disk shielding their X-ray emission from our line of sight. Finally, I examined the origin of radio emission in a sample of radio-quiet AGNs in the context of how a slim disk is likely to alter the optical, X-ray, and outflow characteristics of the central engine, and I found that they may be dominated by radio emission from a compact corona with the addition of uncollimated outflows at higher accretion rates. I conclude with a brief discussion of future observational prospects to improve our understanding of the interaction between AGN emission mechanisms and the efficiency of black hole growth through accretion
Refinements to Superpave Volumetric Mix Design: Incremental Gains and Remaining Gaps in Mixture Performance
No full textThe Superpave volumetric mix design system, introduced in the early 1990s, has significantly improved the rutting resistance of asphalt pavements. However, the system has not sufficiently addressed the growing need for improved cracking resistance and long-term durability, particularly for mixtures with high proportions of reclaimed materials. In response, state departments of transportation (DOTs) have implemented several approaches to improve traditional volumetric mix design procedures. These approaches include: (1) regressed air voids to increase optimum asphalt contents, (2) increased minimum voids in mineral aggregate (VMA) requirements and/or lowered design air voids to yield higher optimum asphalt contents, (3) corrected optimum asphalt content (COAC) to account for reduced binder availability in recycled mixtures, and (4) the Superpave 5 approach to increase in-place density. This tech brief summarizes those approaches and highlights other complementary strategies, including adjustments to design gyrations, minimum asphalt content thresholds, and effective binder volume requirements. While these refinements have demonstrated measurable benefits, they reinforce the need for performance-related approaches such as Balanced Mix Design (BMD).U.S. Department of TransportationFederal Highway Administratio
Post-wildfire mobilization of nutritional elements
No full textWildfires significantly alter watershed dynamics by mobilizing organic carbon (OC) and nitrogen (N) from terrestrial to aquatic ecosystems, impacting watershed functions and water quality. This Ph.D. project investigated both immediate (0-year) and extended (2-year) effects of wildfires on OC and N mobilization in soils and ashes from three major wildfire sites in northern California and Nevada (Dixie, Beckworth, and Caldor fires), emphasizing the role of physicochemical properties of ashes and soils as well as aging process in controlling nutrient mobilization over time.Immediately after the fires, ashes had elevated bulk OC (9.2 – 57.3 mg/g) and N (2.81 – 5.15 mg N/g) contents compared to control soils. Mobile fraction of OC ranged from 0.0093 to 0.029 in ashes and 0.010 to 0.065 in soils. The total mobile OC was substantially increased by wildfires, when the redox reactions played an important role. Wildfire increased the total amount of mobile OC substantially by 5.2 – 574% compared to control soils.
The mobile fraction of N ranged from 0.025 to 0.070 in ashes, with NO3-, NO2-, NH3/NH4+, and organic N representing distinct contributions. Ashes exhibited lower N mobility than soils, potentially due to transformations in N speciation. Notably, the mobile fraction of N was approximately 11 times the values for OC reflecting the greater solubility and high mobility of inorganic and nitrogenous organic compounds post wildfire. The mobile fraction of N was associated with redox reactions of iron (Fe) during wildfires, regulated by the redox reactivity of OC. Similarly as OC, total amount of mobile N was increased by wildfires, for which the relative degree was closely related to the severity of wildfires.
Two years after wildfires, OC mobility ranged from 0.009 to 0.114 in ashes and 0.002 to 0.582 in soils, with a higher aromatic fraction in mobile OC from ashes (40.0 – 65.3%) than control soils (23.3 – 47.0%). The mobility of OC exhibited a significant negative correlation with the aromatic fraction in mobile OC for 2-year samples, not present for 0-year samples, indicating the more important role of aromatic OC in its mobility after aging.
The mobile fraction of N in ashes ranged from 0.052 to 0.118, with significantly higher NO2- concentrations than 0-year samples, indicating substantial denitrification over time. Dissolved organic nitrogen (DON) mobilized from aged ashes was also markedly higher than in fresh samples. Redox reactions played an important role for the mobile fraction of OC and N, when X-ray absorption near edge spectra showed reduction of iron (Fe) through the aging process. The impact of aging on the mobility of OC was closely dependent on the aromatic carbon in ashes and soils impacted by wildfire.
Overall, these findings demonstrate both immediate and prolonged effects of wildfires on OC and N mobilization, with implications for downstream water quality. The sustained export of OC and N, influenced by physicochemical properties and aging, posed risks for eutrophication and disinfection byproduct formation. This study underscores the need for watershed management strategies that address both short- and long-term impacts of wildfires on nutrient dynamics in fire-prone regions