The tangential cells are known to be directionally selective with distinctive directional preference. Anisotropic energy is energy that is directionally specific. This bulging is caused by slower and less anisotropic, or directionally dependent, growth. The onshore area contains a cluster of wells directionally drilled into offshore formations. The varying composition of the melon creates a sound velocity gradient that refracts sound directionally. Many modern oil and gas wells are drilled directionally. This is considered as directionally unstable kinked crack growth. This is considered as directionally stable kinked crack growth. Analogous directionally selective cells are not thought to exist in the primate retina . Nonwovens consist of a manufactured sheet, web or mat of directionally or randomly oriented fibers. This feels like the fibers are directionally arranged. When echolocating, the sperm whale emits a directionally focused beam of broadband clicks. Above this speed, the vehicle will be directionally (yaw) unstable. They are characterized by symmetry, morphology, and directionally dependent physical properties. Each layer is coated with resin, followed by another directionally alternating layer laid on top.