A direct kinetics study of the product-forming channels of the reaction of isoprenederived hydroxyalkylperoxy radicals with NO has been performed at 100 Torr pressure and 298 K using the turbulent flow technique with high-pressure chemical ionization mass spectrometry for the detection of reactants and products. For comparative purposes, a similar study was also performed for the reaction of 1-and 2-butene-derived hydroxyalkylperoxy radicals with NO. The measured hydroxyalkylnitrate product channel branching ratios were determined to be 0.061, 0.068, and 0.070 for the 1-butene, 2-butene, and isoprene systems, respectively. The results are compared to previous measurements of the hydroxyalkylnitrate-branching ratios for these systems, and the atmospheric significance of the results is discussed.
The overall rate constants of the NO reaction with chloroalkylperoxy radicals derived from the Cl-initiated oxidation of several atmospherically abundant alkenes-ethene, propene, 1-butene, 2-butene, 2-methylpropene, 1,3-butadiene, and isoprene (2-methyl-1,3-butadiene)-were determined for the first time via the turbulent flow technique and pseudo-first-order kinetics conditions with high-pressure chemical ionization mass spectrometry for the direct detection of chloroalkylperoxy radical reactants. The individual 100 Torr, 298 K rate constants for each monoalkene system were found to be identical within the 95% confidence interval associated with each separate measurement, whereas the corresponding rate constants for 1,3-butadiene and isoprene were both approximately 20% higher than the monoalkene mean value. Our previous study of the reaction of hydroxylalkylperoxy radicals (derived from the OH-initiated oxidation of alkenes) with NO yielded identical rate constants for all of the alkenes under study, with a rate constant value within the statistical uncertainty of the value determined here for the NO reaction of chloroalkylperoxy radicals derived from monoalkenes. Thus, the reaction of NO with chloroalkylperoxy radicals derived from dialkenes is found to be significantly faster than the NO reaction with either chloroalkylperoxy radicals derived from monoalkenes or hydroxyalkylperoxy radicals derived from either mono- or dialkenes.
This article describes an innovative application of a social justice-infused pedagogy to an out-of-school program for urban high school students. Using an interdisciplinary framework, the program featured a coherent synthesis of science, technology, engineering, and math (STEM) education, highlighting environmental and food justice perspectives; social justice education; and career and college planning. We used qualitative content analysis to analyze two separate interviews with six female and three male students of color ranging in age from 15 to 18 with an average age of 16.1 (SD=1.26) across an approximately 10-month time span. Utilizing a model of critical consciousness development as our organizing framework, we explored the students' understanding of environmental and food justice issues. Participants indicated that they were actively engaged in learning about food and environmental justice, exploring STEM careers, and investigating
This study examines an out-of-school time program targeting elementary-aged youth from populations that are typically underrepresented in science fields (primarily African-American, Hispanic, and/or English Language Learner participants). The program aimed to foster positive attitudes toward science among youth by engaging them in growing plants hydroponically (in water without soil). Participants' attitudes toward science, including anxiety, desire, and self-concept, were examined through pre-post survey data (n = 234) over the course of an afterschool program at three separate sites. Data showed that participants' anxiety decreased and desire increased for both male and female participants over the program. Self-concept increased for female participants at all three sites but did not change significantly for male participants. Participants' first language (English or Spanish) was not a factor in attitude outcomes. The primarily positive outcomes suggest that hydroponics can be a useful educational platform for engaging participants in gardenbased programming year round, particularly for settings that do not have the physical space or climate to conduct outdoor gardening. Similarities in positive attitude outcomes at the three sites despite differences in format, implementation, and instructor background experience suggest that the program is resilient to variation in context. Understanding which aspects of the program facilitated positive outcomes in the varied contexts could be useful for the design of future programs.
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