Fish scale the surface, interacting only with the riblet tips, not causing any high-veloctiy flow in the valleys. Since this high velocity flow now only interacts with the riblet-tip, which is a very small surface area, the momentum transfer which causes drag is now much lower than before, thereby effectively reducing drag. Also, this reduces the cross-stream velocity fluctuations, which aids in momentum transfer too. The rough, sandpaper-like texture of shark and ray skin, coupled with its toughness, has led it to be valued as a source of rawhide leather, called shagreen. One of the many historical applications of shark shagreen was
Terror-Creatures from the Grave Terror-Creatures from the Grave Terror-Creatures from the Grave () is a 1965 horror film directed by Domenico Massimo Pupillo. The film was a co-production between Italy and the United States through M.B.S. Cinematografica, G.I.A. Cinematografica and International Entertainment Corp.. An attorney arrives at a castle to settle the estate of its recently deceased owner. The owner's widow and daughter claim that the late lord could summon the souls of ancient plague victims, and that his spirit roams the castle. Soon occupants of the castle begin to die in gruesome, violent ways. Before 2015, Ralph Zucker was credited as an alias