The characteristics of fully-developed, laminar, pressure-driven, incompressible flow in rough circular microchannels are studied. A novel analytical model is developed that predicts the increase in pressure drop due to wall roughness in microtubes. The wall roughness is assumed to posses a Gaussian isotropic distribution. The present model is compared with experimental data, collected by other...

Skin status of produce is important in determining fruit quality. Sensory evaluation is often used to express this characteristic. A new method, atomic force microscopy (AFM), was proposed to denote the changes of skin status. Arithmetic roughness (Ra) and root mean square roughness (Rq) of ‘Jinxiu’ yellow peach (prunus persicu L. Batsch.) were analysed by AFM. The Ra and Rq values increased wi...

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 chrom...