年間 12 号発行
ISSN 印刷: 1091-028X
ISSN オンライン: 1934-0508
Indexed in
AN EXPERIMENTAL STUDY ON THE PERMEABILITY OF FLYING AND FLIGHTLESS BIRDS’ CONTOUR FEATHERS
要約
Contour feathers of birds consist of layers of plumulaceous and pennaceous feathers. Differences in the structures of plumulaceous and pennaceous feathers lead to differences in such functions as heat transfer and air penetration. In this study, samples were collected from plumulaceous and pennaceous feathers of chickens, pigeons, magpies, and ostriches. Measurements were carried out to determine the density and diameter of the plumulaceous barbules as well as layer thicknesses of the pennaceous feathers. Permeability coefficients of the plumulaceous and pennaceous feathers were obtained using an air permeability tester and compared to investigate the effects of fiber diameter, porosity, and number of layers. The highest permeability coefficients were obtained for the plumulaceous and pennaceous contour feathers of the ostrich and chicken while pigeon and magpie recorded the lowest values. The permeability coefficients measured for the plumulaceous contour confirmed the validity of the Carman–Kozeny Relation.