Proton exchange membranes were prepared and characterized for utilization in high-temperature proton exchange membrane fuel cells, HT-PEMFCs. 1-vinylimidazole (1-VIm) and 4-vinylpyridine (4VP) monomers were simultaneously grafted onto pre-irradiated ETFE (ethylene-co-tetrafluoroethylene) films which were prepared using γ-rays with a dose of 100 kGy, as a robust substrate to prepare acid−base composite membranes. The grafting reaction was performed at 60°C for 24 h followed by protonation via phosphoric acid doping in the subsequent step. The effect of adding ferrous salts as promoters in grafting was investigated by characterization of resultant membranes via thermal gravimetric analysis and mechanical tests. The fuel cell tests were conducted under different relative humidities (RHs) and applied temperatures. Membranes prepared with salt addition exhibited superior proton conductivities. Results including up to 80 mS cm −1 conductivity at 110°C in 60% RH and excellent thermal stability, even at 300°C, suggest these membranes are promising for HT-PEMFC applications.
The cultivation area and diversity of genetically modified (GM) crop varieties worldwide is increasing rapidly. Taking Turkey as an example of a country with tight restrictions on the import and use of GM crops but limited resources for product monitoring, we developed a cost-effective 3-tier screening protocol, and tested 110 retail food products and 13 animal feeds available in 2016-2017 for GM ingredients. No evidence was found for the presence of GM wheat or rice in the foodstuffs tested; however, 6 feeds and 3 food products containing soybean and/or maize were positive for one or more GM elements. GM events present in positive samples were identified by event-specific PCR and quantified by real-time PCR. We also compared the results with previous surveys in Turkey.Overall, we observed consistent use of GM animal feeds; however, these were not labelled as GM at the point of sale. Occasional food products also tested positive for GM ingredients, usually at low concentrations that could be attributed to accidental contamination.
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