Blade topography

Detailed observations of hamsters indicate, however, that one individual often does not completely cover the scent mark of another. In addition, I expect that complete covering of one mark by another would be extremely difficult to accomplish for many mammals for a variety of reasons.. For example, if on animal sprays a scent onto a surface it would be difficult for a second to cover each separate spot of scent. Rough surfaces present similar difficulties, and the topography of some scent marks, such as globs of scent on a twig or blade of grass, may also be difficult to cover. 

The common feature of microfibrous surfaces is their topography, rather than their chemical nature. It is well known that certain oxidation conditions produce a whisker or blade-like oxide growth on a metal surface, rather than a film of uniform thickness. Similarly, certain conditions of electrodeposition give dendritic crystals of the deposited metal, not a smooth coating. These are ways of preparing microfibrous surfaces. Details of some typical methods are given in Ref. [1]. 

Computer-aided topography (CAT) scan. CAT scanners locate internal defects in engine components. It is particularly usefiil for sophisticated components such as blades and airfoils with internal passages and cavities. 

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