Institutional Repository

The UDSpace Institutional Repository collects and disseminates research material from the University of Delaware.

  • Faculty, staff, and graduate students can deposit their research material directly into UDSpace. Faculty may use UDSpace to fulfill the University of Delaware Faculty Senate Open Access Resolution, and in many cases may use it to fulfill open access requirements from grant funding agencies.
  • Departments can use UDSpace to publish or distribute their working papers, technical reports, or other research material.
  • UDSpace also includes all doctoral dissertations from winter 2014 forward, and all master's theses from fall 2009 forward.

To learn more about UDSpace, and how you can make your research openly accessible to the public, visit our UDSpace Policies website.


Recent Submissions

The Use of Research in Schools: Principals’ Capacity and Contributions
(Education Sciences, 2024-05-23) Farley-Ripple, Elizabeth N.
Policy expectations for the role of research evidence in educational decision-making have grown exponentially in the U.S. and globally, yet there has been limited attention to school capacity to engage in evidence-informed improvement. In this paper, I address this gap by first conceptualizing principal leadership for evidence use and, second, use this conceptual lens to examine large-scale survey data about school evidence use practices and capacity. Drawing on data from a national survey of more than 4000 educators in 134 schools in the US, I explore school practices and capacity to use research and surface opportunities and needs for principal leadership in evidence-informed improvement. Findings suggest that there is an opportunity to improve the role of research in school improvement decision-making, and that principals may contribute to school capacity in specific ways that relate to developing human capital, influencing culture, leveraging resources, and shaping decision-making. Data reveal moderate evidence of research use in agenda setting and of organizational routines that support research use, but lack of uptake of those routines for research use as well as limited investment in resources (e.g., time). Further, decision-making was distributed across a wide range of improvement initiatives, with evidence of a lack of clarity about goals. Although principals report confidence and experience with using research, overall school staff also reported limited experience with prior research, including coursework or participation in research, and low confidence in critically consuming research. Implications point to the need to strengthen principals’ own evidence use capacity as well as focus on dimensions school capacity as part of evidence use initiatives. Recommendations suggest strategies for developing principals’ knowledge and skills around leadership for evidence-informed improvement.
Unwrapping the Native Plant Black Box: Consumer Perceptions and Segments for Target Marketing Strategies
(HortTechnology, 2024-05-23) Rihn, Alicia L.; Torres, Ariana; Behe, Bridget K.; Barton, Sue
The increasing demand for sustainable products has helped spur demand for native plants. This study used an online survey of 2066 US consumers, a factor analysis, and Ward’s linkage cluster analysis to identify unique customer segments in the native plant marketplace. The following three clusters were identified: native averse (31.6%), native curious (35.7%), and native enthusiast (32.7%). The native enthusiast cluster agreed strongly with positive statements related to native plant perceptions and attributes. The native averse cluster exhibited the lowest level of agreement with these items and the greatest level of agreement with negative or neutral statements about native plants. The native curious cluster was intermediate between the other clusters but generally agreed with positive attributes. Demographic characteristics impacted cluster membership. The marketing implications are discussed.
A Simple Mobile Plausibly Deniable System Using Image Steganography and Secure Hardware
(Proceedings of the 2024 ACM Workshop on Secure and Trustworthy Cyber-Physical Systems, 2024-06-19) Xia, Lichen; Liao, Jinghui; Chen, Niusen; Chen, Bo; Shi, Weisong
Traditional encryption methods cannot defend against coercive attacks in which the adversary captures both the user and the possessed computing device, and forces the user to disclose the decryption keys. Plausibly deniable encryption (PDE) has been designed to defend against this strong coercive attacker. At its core, PDE allows the victim to plausibly deny the very existence of hidden sensitive data and the corresponding decryption keys upon being coerced. Designing an efficient PDE system for a mobile platform, however, is challenging due to various design constraints bound to the mobile systems. Leveraging image steganography and the built-in hardware security feature of mobile devices, namely TrustZone, we have designed a Simple Mobile Plausibly Deniable Encryption (SMPDE) system which can combat coercive adversaries and, meanwhile, is able to overcome unique design constraints. In our design, the encoding/decoding process of image steganography is bounded together with Arm TrustZone. In this manner, the coercive adversary will be given a decoy key, which can only activate a DUMMY trusted application that will instead sanitize the sensitive information stored hidden in the stego-image upon decoding. On the contrary, the actual user can be given the true key, which can activate the PDE trusted application that can really extract the sensitive information from the stego-image upon decoding. Security analysis and experimental evaluation justify both the security and the efficiency of our design.
(University of Delaware, 2023-05) Cobb, Holly
Produced water is a highly concentrated brine produced during the extraction of oil and natural gas from geological formations. When spilled, it threatens nearby vegetation and groundwater. The current way of dealing with produced water spills is to excavate the impacted soil and send it to a specialized landfill. This study is concerned with the lab-scale development of an engineered system to remediate salt contamination from produced water spills. Evaporative flux is the process where water passes upward through soil as it evaporates at the surface, carrying solutes with it. Crystallization modifiers are compounds that alter the precipitation of minerals, delaying the onset of crystallization and/or modifying crystal habit, until salts approach or emerge at the surface. Evaporative flux and crystallization modifiers provide the basis for the design evaluated herein, where a constant supply of treatment solution consisting of water and crystallization modifier is supplied at the base of contaminated soil and transports through soil via evaporative flux. A remediation system was devised in the lab based upon these ideas, where a Mariotte bottle which exerts a constant hydraulic head on the system is connected to a beaker containing a 3cm depth of contaminated soil. To create a brine-contaminated soil, a 3.8M salt solution saturates a loamy sand followed by oven drying. This contaminated soil was passively flushed with treatment solution containing various concentrations of a crystallization modifier for five days, before being dried and analyzed by depth. The electrical conductivity of each depth layer of the soil column was collected to understand where the salt was removed and where it remained. Lab-scale experiments show up to 96% removal using a 3mM potassium ferrocyanide solution. Experiments testing the ideal dosage and application of crystallization modifier, the potential use of fabrics to harvest salts, and the impact of using real produced waters were evaluated to improve this system before it is repeated at pilot scale.
(University of Delaware, 2023-05) Rzepski, Alissa
Cartilage is an avascular tissue that allows frictionless mobility of joints. Cartilage cells (chondrocytes) reside in a matrix of collagens (type II collagen [Col2]) and proteoglycans (aggrecan [Acan]) to bear mechanical load [2, 10, 14]. Unfortunately, cartilage is incapable of self-repair and damage leads to cartilage degradation in osteoarthritis (OA). Autologous chondrocyte implantation (ACI) is used to treat small, focal cartilage defects. Chondrocytes are isolated from healthy regions of cartilage in damaged joints, expanded on stiff polystyrene to increase number, then reimplanted into damaged regions to stimulate repair. Unfortunately, ACI ultimately fails [9, 18, 20, 23]. During expansion, chondrocytes become larger, elongated, and express fibroblastic matrix (type I collagen [Col1]) and contractile (transgelin [Tagln]) molecules, which are biomechanically inferior [2, 14, 22, 23, 39, 41, 43]. Additionally, cellular filamentous (F-)actin organization changes from cortical F actin to F-actin stress fibers. Our previous research indicates formation of F-actin stress fibers plays a key role in chondrocyte dedifferentiation [1]. In the present study, we examined ways to repress F-actin stress fiber formation by examining master regulators of actin networks, the Tropomyosins (Tpm), which bind and stabilize specific F-actinnetworks [32, 41]. Therefore, we hypothesize that targeting specific stress fiber actin stabilizing Tpms will repress F-actin stress fiber networks and promote chondrogenic redifferentiation after expansion.