An Investigation of the Electrical Properties of Pressboard Impregnated with Mineral Oil-Based Nanofluids at Different Concentrations of Fe₃O₄ Magnetic Nanoparticles

Figure 7

Scanning electron microscopy (SEM) images of the pressboard surface. (a) The surface features of impregnated pressboard with conventional mineral oil. (b) The surface features of impregnated pressboard with mineral oil-based Fe₃O₄ (0.01%). (c) The surface features of impregnated pressboard with mineral oil-based Fe₃O₄ (0.03%). (d) The surface features of impregnated pressboard with mineral oil-based Fe₃O₄ (0.05%).

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(b)

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