10 research outputs found

    Defluorination of perfluoroalkyl acids is followed by production of monofluorinated fatty acids

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    We investigated the capability of microorganisms isolated from environments polluted with perfluoroalkyl adds (PFAAs) to conduct biotransformation of these emerging pollutants. Two different microbial consortia (chemoorganoheterotrophic bacteria and total yeast and molds) were isolated from two river sediments in Saitama and Osaka, Japan, known for long term pollution with perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). The microbial consortia were incubated in the presence of added PFOS and PFOA, and decreases in concentrations of these compounds were between 46-69% and 16-36%, respectively. Decreases in concentrations were, in part, due to sorption on biomass, but defluorinated PFOS and PFOA products were not detected. However, untargeted analysis suggested the presence of several metabolites found only in samples from consortia with PFOS and PFOA but not in the control samples. Molecular formula candidates were narrowed down to two options, C18H28O5F and C21H27O4. It was assumed that these formulas were associated with unsaturated monofluorinated fatty acids and hydrocarbons with multiple unsaturated bonds or ring structures. (C) 2018 Elsevier B.V. All rights reserved.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3114

    Construction and Effect of the community developing the class of technology subject.

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    本研究は、技術科の授業を開発する教員の共同体を構築することによって、授業が改善されるとともに、参画した教員が授業開発に対する知見を獲得できることを実証した。改善した授業は、「技術ゲーム」と呼んでいる授業である。改善のプロセスを記述し、コミュニティに参加した教員の考えについての調査結果をもとに考察した。This study demonstrated that the class was improved and teachers got that knowledge to develop the class by constructing the community of teachers that developed the class of the technology subject. The improved class is named "the technology game". We described process of the improvement. And we considered it based on the result that investigated the thought of teachers that participated in the community
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