Background/Aims: To determine the roughness of the surface of human skin at highly sun-exposed anatomical sites in a wide age range in order to derive consequences for sunscreen application. Methods: The forehead, cheek, nose, shoulder, and dorsal hand of 4 age groups (0–9, 20–39, 40– 59, and >60 years) were investigated by replica formation, and areal topography was determined by confocal chro...

The effect of the surface roughness on nanoindentation results was investigated instancing a series of CrN thin films deposited by unbalanced magnetron sputtering. The arithmetic roughness (Ra) of the films ranged between 2 and 10 nm and was measured by atomic force microscopy. The measured surface topography was incorporated into a finite element model, which allowed simulating the indentation...

Consider two sequences generated by ",,+ i Mi"„<hn)hn*\ M'i"„+X,b„), where the a„ and b„ are positive and M and M' are means. The paper discusses the nine processes which arise by restricting the choice of M and M' to the arithmetic, geometric and harmonic means, one case being that used by Archimedes to estimate it. Most of the paper is devoted to the arithmetic-harmonic mean, whose limit is e...