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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. 

Abstract: Nationwide K–6 engineering and coding standards have made it increasingly important to prepare elementary preservice teachers (PSTs) to teach these subjects confidently and effectively. Robotics, which combines coding and engineering, provides a rich context for developing PSTs’ expertise and self-efficacy. This study builds on prior work in which PSTs in an instructional technology course collaborated with undergraduate engineering students to co-teach robotics lessons to fifth graders. Using a multiple-embedded case study approach, we examine how the interactions and teaching roles within these partnerships influenced PSTs’ teaching self-efficacy. Drawing on reflections, lesson recordings, surveys, and interviews, we present the cases of three PSTs—Lisa, Madison, and Kayla—who experienced varying levels of partner support and student engagement. Lisa and Madison were both compelled to lead robotics instruction due to perceived lack of support from their engineering partners, yet they experienced contrasting outcomes: Lisa struggled with disengaged students and malfunctioning robots, which diminished her self-efficacy, while Madison's success with highly engaged students bolstered hers. Kayla, in contrast, developed self-efficacy over time through a productive partnership with a supportive engineering student. These cases highlight the complex relationship between partner dynamics, teaching roles, perceived success, and self-efficacy development. Implications for supporting PSTs in engineering-integrated experiences are discussed. 

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. 

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