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Polyethylene oxide (PEO)-based solid composite electrolytes (SCEs), with inorganic fillers, are studied extensively due to their effective balance between mechanical and electrochemical properties. The correlation between the composition of SCEs and their electrochemical behavior has been studied extensively, primarily focusing on the type of polymer matrix with a bias towards high lithium (Li) salt. In this study, we examine the changes in the properties of SCEs at two low EO : Li ratios, 43:1 and 18:1, in the PEO-LiTFSI matrix (with and without 10 wt% of 5 μm LLZTO) and evaluate their impact on Li stripping and plating reactions. Although higher salt concentration (18:1) results in substantially higher ionic conductivity (by approximately an order of magnitude), interestingly we observe that lower salt concentration (43:1) exhibits up to 3 times longer Li cycling life. Notably, electrolytes with low salt concentration (43:1) are much stiffer, with compressive modulus more than twice as high as the 18:1 counterpart. Although the ionic conductivity of the electrolyte is often the most immediate concern in the electrolyte design process, these findings accentuate the equal importance of mechanical properties in order to ensure successful electrolyte performance throughout prolonged Li cycling. 

Zinc dry electrodes were fabricated and investigated for wearable electrophysiology recording. Results from electrochemical impedance spectroscopy and electromyography functionality testing show that zinc electrodes are suitable for use in electrophysiology. Two electrode configurations were tested: a standard disc and a custom tripolar concentric ring configuration. However, no functional benefit was observed with the tripolar concentric ring electrodes as compared to the disc electrodes.Zinc, Electrodes, Concentric Ring Electrodes, EMG, Biosensing 

Public agencies and other funding organizations have often defined rural in reference to “urban” and using parameters such as population density, access to cities, and distance to market areas. Using such definitions of rurality within the context of K-12 education as a way to support these systems is challenging because of the diverse geographic and socio-cultural identities of these places despite a common “rural” designation. This study aims to analyze elementary teachers’ perceptions of their school context and role within that context to better understand the diversity of what it means to be rural. Semi-structured interviews with 3rd–5th-grade teachers (n = 35) were used. Data sources also included identity and community walk slides created by these teachers. Structured interview prompts were tailored to these activities. A priori and emergent coding analyses were used to examine teachers’ conception of their rural context and their role within that context. The results show that rural, as defined by teachers, is a diverse and connected place in which diverse community assets support teachers in their instruction in unique ways. By better understanding the diversity of what it means to be rural, we begin to understand the ways in which context shapes experience and best determine how to support rural educational experiences for both teachers and students. 

Abstract Knowledge of the behaviour of marine‐based ice sheets during times of climatic warming, such as the last deglaciation, provides important information to understand how ice sheets respond to external forcing. We analysed swath bathymetric and acoustic sub‐bottom profiler data from Wrigley Gulf on the western Amundsen Sea shelf, West Antarctica, to identify glacial features and reconstruct past changes in the extent of the West Antarctic Ice Sheet (WAIS) and ice flow directions. Glacial bedforms mapped within a bathymetric cross‐shelf trough include features showing cross‐cutting and overprinting relationship and indicate changes in ice‐flow orientation. Here, we distinguish at least two phases of different ice‐flow patterns on the Wrigley Gulf shelf. During the earlier phase, seaward ice stream flow on the inner shelf was deflected towards the east due to the existence of an ice dome on the middle‐outer continental shelf. Retreat of grounded ice towards the centre of this dome is indicated by the asymmetric cross profile of recessional moraines mapped on the middle shelf. The later glaciation phase was characterized by fast, NNW‐directed ice flow across the shelf along a broad front and subsequent stepwise landward retreat, which is evident from the common occurrence and orientation of mega‐scale glaciation lineations and grounding zone wedges on the middle‐inner shelf. It is uncertain whether the two phases of glaciation recorded on the seafloor occurred during the last and penultimate glacial periods or at different times of the last glaciation. Reliable chronological constraints from sediment cores and additional geomorphological information are needed to understand the cause of the changes in WAIS dynamics reflected by the two ice‐flow phases. 

Despite the intent to advance engineering education with the NGSS, teachers across all grade levels lack confidence in their engineering content knowledge and pedagogy (Hammack & Ivey, 2019). This dilemma is exacerbated by a lack of quality NGSS-aligned curricular materials that integrate science and engineering at the elementary grades— currently, only one elementary unit reviewed by Achieve has received an NGSS Design Badge that includes engineering (NextGenScience, 2020), and these materials are especially unavailable in schools serving high-needs students (Banilower, 2019). Implementation research now acknowledges that contexts and conditions can, and often do, affect the enactment of innovations and that “improving education requires processes for changing individuals, organizations, and systems” (Century & Cassata, 2016, p. 172). Due to geographic location and, often, smaller collegial networks of teachers who teach science, and engineering, rural schools encounter acute challenges in recruiting and retaining teachers (Arnold et al., 2005) and providing content-specific Professional Learning (PL) (Harmon & Smith, 2007). The goal of this NSF DRK12 multi-institution project is to longitudinally investigate the impacts, sustainability, and costs of NGSS implementation, especially in rural contexts. Our approach differs from most interventions in that it is tailored to rural educators in grades 3–5 and offers curriculum-agnostic, fully online PL that supports teachers in utilizing resources and phenomena found in their local contexts to develop and implement engaging, NGSS-aligned engineering instruction. Our intervention began with a five-day (i.e., weeklong) online PL experience in the summer of 2023 for grades 3–5 teachers in each of four western states. Examples of PL sessions provided include: (1) an overview of three-dimensional learning and phenomena-based instruction; (2) a deep dive into the NGSS Science and Engineering Practices (SEPs); (3) instructional practices that encourage equitable student participation and epistemic agency; and (4) building understanding and comfort with NGSS-aligned engineering and design-based instruction for the elementary grades. The initial intensive PL experience had immediate positive impacts on grades 3–5 teachers’ attitudes and efficacy for teaching engineering. We are now exploring how modest supports influence the sustainability of these changes. Over the 2023-2024 academic year, we are providing teachers with a menu of modest supports including: three 90-minute-long online PL meetings each semester, materials for teaching a locally focused engineering design task, and access to a variety of electronic supports (e.g., Google Classroom Site, shared resources). The fall semester online meetings have focused on supporting teachers to identify connections to science and engineering in their school’s community and how to develop NGSS-aligned engineering design tasks that connect to their local communities. Teachers will be implementing their engineering lessons during December 2023 and January 2024.