The diatoms abrade the insects' surfaces, causing them to dehydrate and die. Their bodies are covered in delicate silvery scales which abrade easily. When studs come into contact with pavements they abrade the asphalt or concrete surface. Smaller particles abrade smaller amounts of material and are used to produce a finer finish. Fine-grained ash can infiltrate openings in cars and abrade most surfaces, especially between moving parts. The discarded lines abrade coral polyps and upper tissue layers. Wind-blown sand grains striking any solid object in their path can abrade the surface. Studs abrade dry pavement, causing dust and creating wear in the wheel path. In addition, plaster is much smoother and does not snag clothing or abrade the skin. Inclusions in steel, especially oxides, may abrade the cutting tool. The solid vanadium compounds also abrade engine components. A cast saw can cut, abrade, or burn skin, but those results are uncommon. Akwamus are the Abrade (Aduana) Clan of the Akan ethinic group. If anything, his paintings abrade the false dichotomy between innocence and understanding.