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1. Engaging STEM Transformational Experiences for Early Momentum (ESTEEM)

   Yahdi, Mohammed ; Bracey, Zoe Buck ( November 2019 , National Science Foundation -  Hispanic-Serving Institutions (HSI) Program Principal Investigator (PI) Meeting, November 2019.)

   Need/Motivation (e.g., goals, gaps in knowledge) The ESTEEM implemented a STEM building capacity project through students’ early access to a sustainable and innovative STEM Stepping Stones, called Micro-Internships (MI). The goal is to reap key benefits of a full-length internship and undergraduate research experiences in an abbreviated format, including access, success, degree completion, transfer, and recruiting and retaining more Latinx and underrepresented students into the STEM workforce. The MIs are designed with the goals to provide opportunities for students at a community college and HSI, with authentic STEM research and applied learning experiences (ALE), support for appropriate STEM pathway/career, preparation and confidence to succeed in STEM and engage in summer long REUs, and with improved outcomes. The MI projects are accessible early to more students and build momentum to better overcome critical obstacles to success. The MIs are shorter, flexibly scheduled throughout the year, easily accessible, and participation in multiple MI is encouraged. ESTEEM also establishes a sustainable and collaborative model, working with partners from BSCS Science Education, for MI’s mentor, training, compliance, and building capacity, with shared values and practices to maximize the improvement of student outcomes. New Knowledge (e.g., hypothesis, research questions) Research indicates that REU/internship experiences canmore »be particularly powerful for students from Latinx and underrepresented groups in STEM. However, those experiences are difficult to access for many HSI-community college students (85% of our students hold off-campus jobs), and lack of confidence is a barrier for a majority of our students. The gap between those who can and those who cannot is the “internship access gap.” This project is at a central California Community College (CCC) and HSI, the only affordable post-secondary option in a region serving a historically underrepresented population in STEM, including 75% Hispanic, and 87% have not completed college. MI is designed to reduce inequalities inherent in the internship paradigm by providing access to professional and research skills for those underserved students. The MI has been designed to reduce barriers by offering: shorter duration (25 contact hours); flexible timing (one week to once a week over many weeks); open access/large group; and proximal location (on-campus). MI mentors participate in week-long summer workshops and ongoing monthly community of practice with the goal of co-constructing a shared vision, engaging in conversations about pedagogy and learning, and sustaining the MI program going forward. Approach (e.g., objectives/specific aims, research methodologies, and analysis) Research Question and Methodology: We want to know: How does participation in a micro-internship affect students’ interest and confidence to pursue STEM? We used a mixed-methods design triangulating quantitative Likert-style survey data with interpretive coding of open-responses to reveal themes in students’ motivations, attitudes toward STEM, and confidence. Participants: The study sampled students enrolled either part-time or full-time at the community college. Although each MI was classified within STEM, they were open to any interested student in any major. Demographically, participants self-identified as 70% Hispanic/Latinx, 13% Mixed-Race, and 42 female. Instrument: Student surveys were developed from two previously validated instruments that examine the impact of the MI intervention on student interest in STEM careers and pursuing internships/REUs. Also, the pre- and post (every e months to assess longitudinal outcomes) -surveys included relevant open response prompts. The surveys collected students’ demographics; interest, confidence, and motivation in pursuing a career in STEM; perceived obstacles; and past experiences with internships and MIs. 171 students responded to the pre-survey at the time of submission. Outcomes (e.g., preliminary findings, accomplishments to date) Because we just finished year 1, we lack at this time longitudinal data to reveal if student confidence is maintained over time and whether or not students are more likely to (i) enroll in more internships, (ii) transfer to a four-year university, or (iii) shorten the time it takes for degree attainment. For short term outcomes, students significantly Increased their confidence to continue pursuing opportunities to develop within the STEM pipeline, including full-length internships, completing STEM degrees, and applying for jobs in STEM. For example, using a 2-tailed t-test we compared means before and after the MI experience. 15 out of 16 questions that showed improvement in scores were related to student confidence to pursue STEM or perceived enjoyment of a STEM career. Finding from the free-response questions, showed that the majority of students reported enrolling in the MI to gain knowledge and experience. After the MI, 66% of students reported having gained valuable knowledge and experience, and 35% of students spoke about gaining confidence and/or momentum to pursue STEM as a career. Broader Impacts (e.g., the participation of underrepresented minorities in STEM; development of a diverse STEM workforce, enhanced infrastructure for research and education) The ESTEEM project has the potential for a transformational impact on STEM undergraduate education’s access and success for underrepresented and Latinx community college students, as well as for STEM capacity building at Hartnell College, a CCC and HSI, for students, faculty, professionals, and processes that foster research in STEM and education. Through sharing and transfer abilities of the ESTEEM model to similar institutions, the project has the potential to change the way students are served at an early and critical stage of their higher education experience at CCC, where one in every five community college student in the nation attends a CCC, over 67% of CCC students identify themselves with ethnic backgrounds that are not White, and 40 to 50% of University of California and California State University graduates in STEM started at a CCC, thus making it a key leverage point for recruiting and retaining a more diverse STEM workforce.« less
2. Managed sheep grazing can improve soil quality and carbon sequestration at solar photovoltaic sites

   https://doi.org/10.1002/essoar.10510141.1  

   Elizabeth Towner, Tom Karas ( January 2022 , AGU 2021 Fall Meeting)

   Solar energy development is land intensive and recent studies have demonstrated the negative impacts of large-scale solar deployment on vegetation and soil. Co-locating vegetation with managed grazing on utility scale solar PV sites could provide a sustainable solution to meeting the growing food and energy demands, along with providing several co-benefits. However, the impacts of introducing grazing on soil properties at vegetated solar PV sites are not well understood. To address this knowledge gap, we investigated the impacts of episodic sheep grazing on soil properties (micro and macro nutrients, carbon storage, soil grain size distribution) at six commercial solar PV sites (MN, USA) and compared that to undisturbed control sites. Results indicate that implementing managed sheep grazing significantly increased total carbon storage (10-80%) and available nutrients, and the magnitude of change correlated with the grazing frequency (1-5 years) at the study sites. Furthermore, it was found that sites that experienced consecutive annual grazing treatments benefitted more than intermittently grazed sites. The findings will help in designing resource conserving integrated solar energy and food/fodder systems, along with increasing soil quality and carbon sequestration.
3. Towards the commercialization of colloidal quantum dot solar cells: perspectives on device structures and manufacturing

   https://doi.org/10.1039/C9EE03348C  

   Lee, Hyunho ; Song, Hyung-Jun ; Shim, Moonsub ; Lee, Changhee ( February 2020 , Energy & Environmental Science)

   Over the past decade, colloidal quantum dot solar cells (CQD-SCs) have been developed rapidly, with their performances reaching over 16% power conversion efficiency. Accompanied by the development in materials engineering (CQD surface chemistry) and device physics (structures and defect engineering), CQD-SCs are moving towards commercialization. A broad overview of the requirements for commercialization is thus timely and imperative. Broad comprehension of structure engineering, upscaling techniques, stability and the manufacturing cost of CQD-SCs is necessary and should be established. In this review, the development of device structures is presented with their corresponding charge transfer mechanisms. Then, we overview the upscaling methods for the mass production of CQD-SCs. Comparisons between each of the upscaling techniques suggest the most advanced process close to industrialization. In addition, we have investigated the origin of the photovoltaic (PV) performance degradation. The possible degradation sources are categorized according to external environmental factors. Moreover, strategies for improving the stability of CQD-SCs are presented. In the conclusion, we have reviewed the cost-effectiveness of CQD-SCs in terms of the niche PV market. Step-wise manufacturing cost analysis for the commercial CQD-SCs is presented. In the conclusion, the future direction for environment-friendly CQD-SCs is discussed.
4. The extent of vegetation-driven panel cooling and consequent increase in electricity generation from solar PV sites depend on climate and soil properties

   Bertel, R. ; Choi, C. S. ; Macknick, J. ; McCall, J. ; Ravi, S ( December 2021 , AGU 2021 Fall Meeting Meeting New Orleans, LA)

   Co-locating solar photovoltaics (PV) with agriculture or natural vegetation could provide a sustainable solution to meeting growing food and energy demands, particularly considering the recent concerns of solar PV encroaching on agricultural and natural areas. However, the identification and quantification of the mutual interactions between the solar panels and the underlying soil-vegetation system are scarce. This is a critical research gap, as understanding these feedbacks are important for minimizing environmental impacts and for designing resource conserving and climate-resilient food-energy production systems. We monitored the microclimate, soil moisture distribution, and soil properties at three utility-scale solar facilities (MN, USA) with different site management practices, with an emphasis on verifying previously hypothesized vegetation-driven cooling of solar panels. The microclimatic variables (air and soil temperature, relative humidity, wind speed and direction) and soil moisture were significantly different between the PV site with bare soil (bare-PV) and vegetated PV (veg.-PV) site. Compared to the bare-PV site, the veg.-PV site also had significantly higher levels of total soil carbon and total soil nitrogen, as well as higher humidity and lower air and soil temperatures. Further, soil moisture heterogeneity created by the solar panels was homogenized by vegetation at the veg.-PV sites. However, we found nomore »significant panel cooling or increase in electricity output that could be linked to co-location of the panels with vegetation in these facilities. We link these outcomes to the background climatic conditions (not water limited system) and soil moisture conditions. In regions with persistent high soil moisture (more frequent rainfall events) soil evaporation from wet bare soil may be comparable or even higher than from a vegetated surface. Thus, the cooling effects of vegetation on solar panels are not universal but rather site-specific depending on the background climate and soil properties. Regardless, the other co-benefits of maintaining vegetation at solar PV sites including the impacts on microclimate, soil moisture distribution, and soil quality support the case for solar PV–vegetation co-located systems.« less
5. The value of community technology workers for LPG use: A pilot in Shirati, Tanzania

   https://doi.org/10.1186/s13705-022-00331-x  

   Gill-Wiehl, Annelise ; Sievers, Sara ; Kammen, Daniel M. ( January 2022 , Energy, Sustainability and Society)

   Sustainable Development Goal (SDG) 7 calls for the adoption and continued use of clean-burning stoves by the 2.9 billion people relying on unclean fuels (both solid biomass and kerosene). However, to date, the clean cooking literature has found low rates of efficient stove adoption and continued use. This paper presents the application of a public health community engagement model to the use of clean cooking fuels. We implemented a pilot study with Community Technology Workers (CTWs) as a means to overcome maintenance, education, and behavioral barriers to clean fuel use in rural Tanzania.

   The intervention was a free 6 kg Liquified Petroleum Gas (LPG) cylinder and stove coupled with education from a local technically trained CTW on LPG use. We evaluated the training, work, and impact of a CTW on LPG use on 30 randomly selected households from two villages in a rural district of Tanzania over a 1-year period. After an initial baseline survey, technically trained local CTWs educated the households on safe LPG use and conducted 34 follow up surveys over the next year on their cooking fuel use. Additionally, we conducted qualitative interviews with all households and a focus group with six of the households.

   The resultsmore »from the mixed methods approach show that 80% of families (n = 24) consistently refilled their LPG cylinders and ~ 40% of households exclusively used LPG. Households reported appreciating the CTWs’ visits for providing education and maintenance support, giving them confidence to use LPG safely, reminding them to save for their cylinder, and providing a community driven effort to use clean fuel.

   The findings demonstrate the feasibility of this type of community infrastructure model to promote and facilitate consistent LPG use, but suggest the need to couple this local support with financial mechanisms (e.g., a microsavings program). This model could be a mechanism to increase LPG use, particularly in rural, low-income areas.

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