31825 research outputs found
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State-building and state-formation in Afghanistan: what went wrong?
No full textKaufman, Stuart J.This dissertation investigates the failure of the liberal state-building project in Afghanistan between 2001 and 2021. Following the US-led invasion in response to Al-Qaeda’s September 11, 2001, terrorist attacks on New York and Washington, DC, the international community undertook a two-decade long project to reconstruct Afghanistan as a democratic state aligned with the liberal international system. Despite vast investments in money and personnel, however, this project ended in failure with the Taliban’s swift return to power in August 2021. In this dissertation I ask why the state-building project failed and whether its failure was due to a flawed institutional design, the structural features of the country, or a combination of both. I argue that the mistakes typically highlighted by historical institutionalist accounts of Afghanistan’s state-building failures—poor institutional design, empowering warlords, and poorly conceived counterinsurgency tactics—did indeed matter but provide only a partial explanation. In contrast, I emphasize the degree to which these institutional mistakes must be understood in the context of pre-existing structural factors such as ethnic and tribal fragmentation and longstanding resistance to centralized authority. In short, while institutional factors mattered, they operated within a broader structural context that rendered any top-down liberal state-building project unlikely to succeed. I conclude that any meaningful future state-building attempts in Afghanistan will require not just institutional reform but a long-term societal transformation that reconciles historical patterns of decentralized governance with the obligations of modern statehood.University of Delaware, Department of Political Science and International RelationsPh.D
The design and additive manufacture of antenna systems for space-constrained environments
No full textBarrett, Andrew MarkThe increasing demand for compact, high-performance communication systems in satellite and aerospace applications necessitates innovative antenna solutions that maximize efficiency in space-constrained environments. This research investigates the utilization of additive manufacturing (AM), a rapid prototyping technology, for the design and fabrication of radiating systems in space-constrained environments. Specifically, this research advances the design and fabrication of conformal surface-wave and graded index antennas. By leveraging AM’s ability to create highly complex geometries with precision, this research aims to overcome the limitations of conventional antenna designs, enabling efficient signal propagation and redirection in confined or obstructed environments. The first study focuses on the development of low-profile and conformal surface-wave antennas (SWAs). These SWAs, optimized for multi-material additive manufacturing, take advantage of novel dielectric resins and metamaterial surfaces to confine and guide electromagnetic waves with minimal loss. The next research study involves the incorporation of unusually shaped gradient-index (GRIN) lenses that enable precise wavefront manipulation, enhancing directivity and gain while maintaining a compact form factor. Furthermore, gradient structures are employed to achieve dynamic beam-steering, allowing signals to be efficiently redirected around corners—an essential capability for densely packed satellite arrays and integrated aerospace communication networks. Computational electromagnetic modeling, topology optimization, and multi-material printing techniques are utilized to refine antenna performance, ensuring robust operation across a range of frequencies.University of Delaware, Department of Electrical and Computer EngineeringPh.D
Validation of an instrumented push-and-release test
No full textCrenshaw, Jeremy R.Introduction • Reactive Balance, i.e. the body’s rapid response to a sudden perturbation, is commonly assessed with the Push-and-Release Test, a clinical test that scores users based on the number of steps required to recover from a sudden loss of balance. While clinically feasible and able to discern between fallers and nonfallers, the Push-and-Release Test suffers from limited specificity and the inability to quantify specific aspects of the recovery response. Simple force-plate instrumentation can address these concerns. Using two force-plates, the initial conditions of the participant prior to perturbation onset and the stepping response after perturbation onset can be recorded to better estimate test performance and allow for distinct difficulty levels. This dissertation aimed (1) to assess the accuracy of using force plate-based methods of estimating test performance, (2) to understand the effect of altering test difficulty, and (3) to incorporate these findings into a real-time feedback program designed to improve Push-and-Release Test administration. ☐ Methods • We recruited 30 neurotypical individuals to complete the Push-and-Release test in the anterior, posterior, and lateral directions. Participants were instrumented with a full-body motion capture marker set and completed the test, such that the initial conditions and the stepping response were captured by two force plates. Within each direction, participants completed three separate conditions where difficulty was modulated (Medium and Challenging) or additional constraints were added to the recovery response (Restricted Step Length). Individual components of the recovery response, such as stepping kinematics and ground-reaction forces generated through the trailing limb, were quantified using both motion- and force-based data. Peak lean angular velocity (ω), a whole-body measure of reactive balance skill, was also calculated. This variable is the rate-of-change in the angle of a vector from trail limb ankle-joint-center to the whole-body center-of-mass and a vector aligned with gravity. • For our first aim, we tested two different models using force-based data to estimate ω. The first model was a regression-based approach using a multiple regression analysis that considered stepping kinematics, trail limb contributions, and perturbation difficulty to estimate ω. All predictors were calculated using only force data. Prior to inclusion in our regression models, we evaluated concurrent validity of predictors that could be calculated with both force and motion data. These predictors were perturbation difficulty (shear ground reaction force and lean angle at perturbation onset), step length, and step time. After developing this model, we assessed validity with a leave-one-out-cross validation and applied our regression equation to a secondary dataset consisting of neurotypical young adults. The second model used a mechanical-based approach, utilizing Newton’s Second Law (∑ = a) to calculate center-of-mass motion from force data. Intraclass Correlation Coefficients (ICC(2,1)) were used to assess agreement between our mechanical model and ω. • For our second aim, we assessed the effect of perturbation difficulty on the recovery response using the same dataset by comparing the response from the Medium difficulty condition and the Challenging difficulty condition. Both motion- and force-based measures were included in the between-difficulty-level comparisons. Paired t-tests and Cohen’s d effect sizes for repeated measures were used to test for differences in the recovery response. • For our third aim, we incorporated our findings from the previous two aims to create a real-time feedback system that provides information on both practitioner and patient performance. The primary goals for this feedback system were (1) to create an user interface allowing for hardware specifications, (2) provide feedback to the examiner during test administration on current test difficulty relative to target test difficulty, and (3) provide feedback on examinee performance after test completion considering whole-body motion, individual components of the balance reaction and clinical outcomes. ☐ Results • Aim 1 – Our regression model predicting ω showed moderate-to-strong predictive power and significance across all directions (Anterior: F (5, 560) = 137.0, R2 = 0.55; Posterior: F (5, 559) = 185.3, R2 = 0.61; Lateral: F (5, 536) = 177.4, R2 = 0.63; p 0.8) for all conditions besides step time calculated from force data (IdI = 0.40) and vCOM calculated from motion data (IdI = 0.64) for anterior perturbations. Results for step length and trail limb contributions were mixed. Participants stepped further when recovering from sagittal plane perturbations (p < 0.05, IdI = 0.40 – 1.11). However, for lateral perturbations, the method used contributed to whether step length was significantly different (p < 0.01, IdI = 0.99). Estimating step length with motion data resulted in significantly different step lengths, while using center-of-pressure data resulted in no significant difference (p = 0.29). Trail limb contributions were only significantly different for lateral perturbations, where increases in perturbation difficulty resulted in increases in contributions (p < 0.01, IdI = 0.84). • Aim 3 – This developmental Aim produced the first iteration of a real-time feedback system that can quantify the recovery response mechanics and provide feedback on the difficulty level and proper delivery of the perturbation. This system is currently capable of integrating with data-collection softwares and reading in force data. All a priori goals regarding developing a user interface and providing feedback on examiner performance during test administration were met. For examinee performance, we were able to calculate characteristics of the recovery response, but were unable to detect examiner assistance during multistep recoveries to differentiate between a moderate (1) and severe (0) clinical score. ☐ Discussion • We were able to predict Push-and-Release Test performance, measured as ω, using a regression model incorporating the individual components of the recovery response and perturbation difficulty. A mechanical model of ω performed much worse, but was able to accurately predict vCOM expressed in a plane defined by perturbation direction and a vertical axis. Although planar vCOM is not commonly used as an indicator of reactive balance skill, the vCOM measure has logical validity as it aligns with the goal of arresting the momentum of a fall and concurrent validity as it is related to current estimates of reactive balance skill, such as margin of stability. Model preference (i.e. statistically estimating ω or mechanically estimating vCOM) may depend on whether the user is interested in individual components of the recovery response, but we recommend the mechanical model in most situations, as it performed better. Test difficulty, as defined as by participant lean angle, also played a significant role in affecting the individual components of the recovery response. Using graded difficulties, our test may be more suitable for detecting small changes in balance recovery skills that would not affect the number of steps required to recover from a perturbation (thus remaining undetected by the original Push-and-Release Test). Both models and suggestions on perturbation difficulty were incorporated into our real-time feedback system allowing for the test to be administered at distinct difficulties. ☐ Conclusions • This work expanded on the Push-and-Release Test, an existing clinical assessment of reactive balance, through force-plate instrumentation. In neurotypical individuals, we showed this modification was able to quantify reactive balance skills and that perturbation difficulty was linked to the recovery response. We incorporated these findings into a proof-of-concept real-time feedback system that can be useful to standardize test difficulty and easily assess patient performance. Further work should focus on validating this approach for individuals with reactive-balance impairments, as well as collecting and incorporating feedback from clinicians related to software usage and design.University of Delaware, Department of Kinesiology and Applied PhysiologyPh.D.University of Delaware, Biomechanics and Movement Science Progra
Editorial: Networks and knowledge brokering: advancing foundations, inviting complexity
No full textThis article was originally published in Frontiers in Education by Frontiers Media. The version of record is available at: https://doi.org/10.3389/feduc.2025.1555200.
© 2025 MacGregor, Rodway and Farley-Ripple. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY) (http://creativecommons.org/licenses/by/4.0/). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Framing the Research Topic
As educational ecosystems become increasingly complex and diverse, understanding how knowledge brokerage and relational networks interact can offer pathways for strengthening connections among research, policy, and practice. Knowledge brokers have garnered attention for their capacity to navigate evidence and adapt it for various audiences, while relational networks—spanning professional communities, partnerships, and organizational structures—provide channels through which knowledge flows and evolves. Yet, much of the current literature examines these phenomena independently, and we lack integrated perspectives that clarify how they co-influence policy decision-making, on-the-ground educational change, and system-wide learning.
This Research Topic aims to bridge this gap by examining how knowledge brokers operate within relational networks to cultivate evidence-informed policy and practice in education. Its dual objectives are to advance theoretical and empirical understandings of these intertwined processes and to translate these insights into concrete, actionable guidance for policymakers, educational leaders and practitioners, and researchers.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest
Steering the future: expert knowledge and stakeholder voices in autonomous vehicle policy reports
No full textThis article was originally published in Policy and Society Published by Oxford University Press. The version of record is available at: https://doi.org/10.1093/polsoc/puae041.
© The Author(s) 2025. Published by Oxford University Press.
This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact [email protected] for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site–for further information please contact [email protected] anticipated arrival of autonomous vehicles has created considerable uncertainty for US states because they govern roads. In response, states activated their policy advisory systems. While policy advising at the national level has been studied, less is known about the sub-national level. Similarly, more is known about the use of scientific knowledge by policymakers than about the full range of knowledge deployed in policy advising. This study analyzes reports written for states to help them make sense of an emerging technology in preparation for governance. Committees, university researchers, staff at Department of Transportation, and legislative staff produced different types of reports, for example, more and less academic, focused more or less on topics associated with governance or engineering. Our analysis reveals that state policy advisory systems used two types of processes—convening and expert—and employed three types of expertise—academic, practical, and political—to help prepare to govern this emerging technology. The study provides insight into how states mobilized expertise to address uncertainty around an emerging technology, showing how different actors balanced the need for credible technical knowledge with legitimate stakeholder engagement.This work was supported by National Science Foundation Award 2001455
Delaware 2024 Behavioral Risk Factor Survey
No full textThis report analyzes the 2024 BRFSS data. The objective of BRFSS is “to collect uniform state-specific data on health risk, behaviors, chronic diseases and conditions, access to health care, and use of preventive health services related to the leading causes of death and disability in the United States”. The Delaware Division of Public Health (DPH) operates the state-based Behavioral Risk Factor Survey (BRFS) as part of BRFSS. BRFS is a survey of Delaware’s adult population conducted annually. It considers behaviors connected with an increased risk of disease, premature death, and disability. In 2024, BRFS surveyed 4,360 adults in Delaware aged 18 and older. This study generalizes the prevalence rates of health issues, health care access, chronic diseases, and some behavioral risk factors among the population
Detailed computational modeling of crack patterns of silicon-based anode sheet in lithium-ion batteries upon mechanical stress
No full textThis article was originally published in Energy Materials and Devices. The version of record is available at: https://doi.org/10.26599/EMD.2025.9370054.
© The Author(s) 2024. Published by Tsinghua University Press.
The articles published in this open access journal are distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Silicon (Si)-based anodes, where Si serves as the active material, have garnered significant attention due to their potential to achieve high electric capacity in lithium-ion batteries (LIBs). A key challenge with Si-based anodes is their susceptibility to create in-plane cracks caused by stresses from the manufacturing process and cyclic charging, which ultimately shortens battery life and reduces the overall electrochemical capacity. To address this issue, a refined microstructural design of the active material layer is in pressing need to enhance both the performance and longevity of LIBs. We successfully applied the Oyane failure criterion, which models ductile failure under stress triaxiality, to simulate crack initiation and propagation in the binder matrix containing Si particles in the finite element modeling. Given the non-linear plastic deformation of the binder, this criterion was formulated based on cumulative strain increments. The computational results of microcrack formation within the active material layer under uniaxial tension were then validated by the experimental observations. Furthermore, we developed several models with varied particle arrangements, comparing each simulated crack path to actual microstructural images obtained via scanning electron microscopy. The findings confirm the accuracy of the model, underlying its promising application in optimizing the microstructure of Si-based anodes for enhanced LIB performance and durability.
Graphical Abstract available at: https://doi.org/10.26599/EMD.2025.9370054.Akio Yonezu acknowledges the support of JSPS KAKENHI (Grant No. 21H01217) from the Japan Society for the Promotion of Science. Jun Xu acknowledges the support of the Startup funds from the University of Delaware
Ergotism in an organic sow herd and the impact on lactation performance and subsequent reproductive performance
No full textThis article was originally published in Journal of Swine Health and Production. The version of record is available at: https://doi.org/10.54846/jshap/1408.
© 2025 American Association of Swine Veterinarians. This work is licensed under Creative Commons Attribution-NonCommercial 4.0 International (https://creativecommons.org/licenses/by-nc/4.0).Ergot alkaloids (EA) are produced by fungi, including Claviceps purpurea, which can lead to EA contamination of wheat and cereal grains and cause sow agalactia by inhibiting prolactin production. In this case of sow agalactia and increased piglet mortality, a diagnosis of ergotism was made based on clinical signs and feed analysis. The lactation diet had EA at 330 ppb and was fed to sows for 12 to 14 days resulting in 79% (50%) mean (SD) mortality in exposed litters. Ergot alkaloid levels as low as 0.33 mg/kg of feed (0.33 ppm) may result in clinical signs in lactating sows
Sources, fate, and biological impacts of microplastic debris in the Delaware Estuary
No full textCohen, Jonathan H.The goal of this project was to determine the sources, distribution, composition, and biologic impact of microplastic debris within the Delaware Estuarine system. Specifically, this project (1) provides the methodology to quantify mismanaged plastic debris entering the coastal Delaware Bay from terrestrial sources through watershed raster modeling; (2) quantifies and characterizes microplastic debris throughout the water-column in the Estuarine Turbidity Maximum; and (3) seeks to determine the biological impact plastic has to the estuary through body burden analysis of ecologically important species and physiological impacts to important zooplankton species. ☐ I developed a geospatial hydrologic model quantifying mismanaged plastic debris based on land-use characteristics to determine areas of high plastic output along the coastal Delaware Bay watersheds. This model, along with past observations, aids in interpreting plastic concentrations throughout the Delaware Bay with a focus on previously recorded high plastic zones. The model will be constructed through aggregation of population density, industrial, commercial, and institutional (ICI) land-use, as well as municipal and mismanaged waste data. Utilizing reported United States litter statistics I calculate that an additional 1.8% of municipal solid waste is released into the environment as plastic litter. Given land-use characteristics I find that residential land-use litter between 6 x 10-7 tons m-2 to 0.001 tons m-2 given population density. Additionally, ICI wastes 6 x 10-6 tons m-2. Using these spatial statistics, a modeling case study of the St. Jones River Watershed find that 2.7 tons of plastic is exported to the Delaware Bay annually by the St. Jones River watershed. This model was used to determine that northern Delaware watershed had the potential to contribute more plastic litter into the environment than southern Delaware watersheds. ☐ Marine microplastics are a pervasive pollutant, with estuaries considered a sink for plastic debris. Due to dynamic physical influences in an estuarine system, residence times of particulate debris – including plastic material – increase, thus aggregating material at higher rates than the open ocean. The goal of Chapter 3 was to quantify, characterize, and contextualize microplastic debris in the Delaware Bay’s Estuarine Turbidity Maximum (ETM) and the surrounding region. In the Delaware Estuary it was previously found that the ETM region accumulates microplastics at higher concentrations relative to the remainder of the bay. Previous research in this region has focused on the characterization of surface material. In this study, I characterize the morphology, size, and polymer identities of microplastic material throughout the water column within the Delaware Bay ETM region. Microplastics were found at all stations throughout the sampling region, with average ETM concentrations of 1.4 MP/m3, 0.5 MP/m3, and 0.8 MP/m3 found at the surface (0.5m), mid-water (7m), and bottom (12m) depths, respectively. Fragments were the most abundant plastic type, followed by fibers, across all depths, whereas beads were found more commonly at depth. µFTIR analysis suggests fragments were predominately polyethylene, fibers were commonly polyester or rayon (a semi-synthetic material), and beads were primarily polystyrene. These analyses establish that microplastics are not simply a surface water feature and provide a comprehensive understanding of common microplastic characteristics. In doing so, we further contextualize the microplastic problem in the Delaware Estuary. ☐ Plastic concentrations in the water column were then related to the occurrence of plastic material within estuarine fish and invertebrate digestive tracts and gills, with a focus on the economically important blue crab, Callinectes sapidus. The aim of Chapter 4 is to investigate whether such plastic aggregations correlate with plastic body burdens in estuarine organisms, such as the Atlantic Blue Crab (Callinectes sapidus) and other abundant and ecologically important species. Estuarine organisms were sampled across 4 stations within the Delaware Bay throughout the spring of 2021, in regions of high and low plastic concentrations. Additionally, monthly mature female blue crab stomach samples were collected throughout 2021 and summer of 2023, along with mature male blue crabs in June of 2024. While 12% of estuarine organisms contained plastic in their stomach or gills, 26% of C. sapidus females, and 30% of C. sapidus males containing plastic. Plastic identified were predominantly fibers with an average of 1-2 pieces found per organism. Seasonal analysis reveals C. sapidus collected in the spring (April and May) contained more plastic than other seasons. Plastic body burdens were prevalent across sampling locations and species, with no significant differences observed based on uptake method, age, size, or habitat. These analyses provide insight into spatial patterns of microplastic body burdens within an array of estuarine organisms and C. sapidus. ☐ Finally, zooplankton physiological condition in response to environmental plastic was assessed for the mysid shrimp, Neomysis americana, a key component to the estuarine food web. Using thermal performance curves for metabolic rate, coupled with O:N ratios as an indicator of metabolic substrate, I tested for seasonal (summer, winter) and location (low and high plastic load) effects on these metrics of physiological performance. The estuarine mysid species, Neomysis americana, was collected from high microplastic and low microplastic locations within the Delaware Bay. Mysids were assessed for their respiration and excretion rate when acutely acclimated in the laboratory to a range of temperatures, representing a multi-stressor scenario. No difference was observed between respiration rates, nitrogen excretion or O:N between locations. Although, an increase in respiration rate and nitrogen excretion rate was observed from winter to summer at the high microplastic location. Specifically, during winter, we see a drastic increase in respiration rate at 10°C, with a high Q10 (11.6) between 2°C and 10°C. These results may indicate an initial stress response at acute temperatures of 10°C in the winter as opposed to a larger thermal window in the summer. Furthermore, no metabolic differences were detected at the current concentrations of microplastic in the bay. However, future studies exploring theoretical microplastic exposure limit or ingestion may reveal additional trends. ☐ Overall, this dissertation identifies sources and hotspots of terrestrial plastic waste through land use modeling, the accumulation and identification of microplastic in the Delaware Bay, and highlights potential ecological implications. This work lays the foundation for targeted mitigation and management strategies through identifying body burdens of estuarine species, metabolic effects on zooplankton, and identifying regional plastic litter aggregations. Ultimately, this work serves to address the pervasive issue of plastic pollution and its threat to ecosystem health.University of Delaware, School of Marine Science and PolicyPh.D
Raja Redux
No full textThis article was originally published in International Textile and Apparel Association Annual Conference Proceedings. The version of record is available at: https://doi.org/10.31274/itaa.18645.
© 2024 The author(s). Published under a Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Raja Redux reflects an Indian-American heritage by blending tradition and modernity. Inspired by the saree’s pleating and draping with the structured masculinity of menswear oxfords, this design symbolizes balancing cultural identity and new influences. The design pays homage to Rajasthan’s saree draping style (Kaamya, 2019) while incorporating traditional block printing and sheesha embroidery (Ganguly, 2013). Drawing from designers like Siddhartha Tytler, Jugnu Lahore, and Suketdhir, the design fuses fashion, merging cultural craftsmanship with Western silhouettes. This garment celebrates Indian sartorial history while reinterpreting it through contemporary formalwear, honoring heritage while embracing innovation