URL: https://www.researchgate.net/profile/Sreejith-Mohan/publication/323299175/figure/fig2/AS:635594308861953@1528548900849/Sem-images-of-nano-alumina-coated-specimens-a-run-6-b-run-1-and-c-run-9_Q640.jpg
URL2: https://www.researchgate.net/figure/Sem-images-of-nano-titania-coated-specimens-a-run-8-b-run-6-and-c-run-1_fig7_323299175