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EVOH’s excellent gas barrier properties have enabled its continued market growth in numerous applications including food packaging, fuel tanks, and construction. However, EVOH’s susceptibility to thermo-oxidation limits its ability to be reprocessed. While it is generally known that EVOH degradation leads to cross-linking, detailed degradation rates and mechanisms are not well established. Understanding EVOH degradation has been elusive because readily accessible thermal and spectroscopy methods do not reveal significant changes. Moreover, gel permeation chromatography requires specialized solvents and columns. We report that measuring changes in viscoelasticity with time-resolved rheology (TRR) is a facile way to monitor the temporal dynamics of EVOH degradation. TRR was performed on EVOH grades with ethylene copolymer contents of 27, 32, 48 mol%. As expected, the grade with the highest ethylene content was the most stable. However, with time, all the EVOH grades transitioned from a Carreau-like fluid to a power law fluid and no longer exhibited terminal behavior. Cole-Cole plots also revealed that EVOH relaxation evolved from rapid process into a long, complex process consistent with network formation. The mechanism of degradation was further elucidated by using 13C distortionless enhancement of polarization transfer (DEPT-135) nuclear magnetic resonance spectroscopy. These results showed that degradation occurred by ring-opening of lactone terminal groups that led to cross-linking. This enhanced understanding provides a foundation for developing methods to probe and mitigate EVOH degradation. 

Enhanced and rapid surveillance for diseases is critical to public health and meeting United Nations' Sustainable Development Goal for Good Health and Well‐being by allowing for targeted and accelerated prevention and control response strategies. Human malaria, caused byPlasmodiumspp. and transmitted by mosquitoes is no exception. Advances in sustainable materials provide an opportunity to improve fast, sustainable, and equitable testing assays. Here, naturally abundant polymers and biomaterials, such as cellulose nanocrystals (CNCs) and chitosan, were used to increase antibody density deposition on the assay detection line when compared to traditional free antibody deposition, and thus the sensitivity, of easily assembled rapid tests designed to detectPlasmodium vivaxinfective (sporozoite) parasites in mosquitoes, a critical indicator of malaria transmission. The immobilization of antibodies onto chitosan‐coated CNCs allowed for antigen detection with a lower number of antibodies used in each test; likewise, the immobilization allowed to directly place the CNC‐Ab without the traditionally needed blockers layer on the paper like bovine serum albumin (BSA). This bio‐based prototype of a paper‐based dipstick assay shows a promising pathway for the development of rapid disease surveillance tools using sustainable and globally available materials. 

This Innovative Practice Full Paper presents findings on the impact of framing Engineering as a prosocial career on high school students’ engineering identity formation. Engineers are often stereotyped as people who work alone and are primarily motivated by financial rewards. This stereotype may deter students who value altruism from pursuing engineering career pathways. In reality, many engineers work in collaborative, creative, interdisciplinary fields on problems that positively affect society. This work examined the impacts of framing engineering as altruistic on the engineering identity development of low socioeconomic status, predominantly Black high school students in an urban region of the Southern United States. The program consisted of a summer camp and academic year activities that included mentoring from underrepresented minority undergraduate engineering students. The program content was aligned to the US National Academy of Engineering’s Grand Challenges for Engineering (GCEs), a list of 14 critical challenges that society faces that will require engineering solutions to address. Each of these challenges highlights the exciting ways that a career in engineering allows students to serve their communities and improve the lives of others. A convergent, mixed-methods approach was used to understand how this program affected students’ perceptions of and interest in engineering. These results were compared to those for a traditional STEM Saturday informal education program with participants from the same demographic group. The altruistic framing resulted in students’ having a broader definition of engineering as well as increased interest in engineering as a potential career. 

Highlighting the role engineers have in solving community and global challenges has been shown to positively affect students' engineering identity development. Poor water quality and water scarcity have been recognized as a critical global issue by many organizations, including the United Nations. Students of all ages can relate to the importance of having drinkable water through their experiences with thirst, drought, floods, news stories, or just accidentally swallowing salt water while on holiday at a beach. This talk describes the development and implementation of a series of engineering education activities focused on water quality. These activities ranged from three-minute activities for community outreach events to week-long lessons for engineering freshmen. Younger students were able to readily recognize how using different types of filters and natural media can increase the clarity of water with particulate or color contamination. Middle and high school students were able to design and test filter set-ups and learn about the role of nanotechnology in water purification. They also developed analytical and data analysis skills through qualitative and quantitative water quality measurements. Freshman engineering students learned about the water industry, local and global water issues, and performed water quality sampling around their campuses using portable meters that log data via a cell phone app. The activities and results were then used to meet university-course outcomes related to the societal impacts of engineering, statistical analysis, plotting data, and written communication. By centering learning on a tangible and important engineering challenge, this work provides a flexible framework for learning and problem solving that can be tailored to the needs of students from different age groups and for different learning outcomes. 

Abstract BackgroundEngineering‐oriented bridge programs and camps are popular strategies for broadening participation. The students who often serve as counselors and mentors in these programs are integral to their success. PurposePredicated on the belief that mentoring contributes to positive outcomes for the mentors themselves, we sought to understand how undergraduate student mentors approached and experienced their work with a 6‐day overnight, NSF‐sponsored youth engineering camp (YEC). This study was guided by the question: How did YEC camp counselors approach and experience their roles as mentors? Design/MethodsWe conducted an exploratory qualitative study of four Black undergraduate engineering students' experiences with and approaches to near‐peer mentorship in the YEC program. Data consisted of transcripts from two post‐program interviews and one written reflection from each participant. We analyzed data through abductive coding and the funds of knowledge framework. ResultsThrough subsequent interpretation of code categories, we found YEC mentors: (1) engaged in altruistic motivations as YEC mentors, (2) leveraged previous experiences to guide their approaches to mentorship, and (3) engaged in self‐directed learning and development. ConclusionsThis study highlights the knowledge and strategies that YEC mentors drew upon in their roles, and how they sought and achieved various personal, academic, and professional benefits. Insights from this study illustrate how near‐peer mentors can support their and others' engineering aspirations.