Particle toughened, fiber-reinforced composites include a fiber region and an interlayer region between the fibers. The present invention provides a hair growth promoting composition having excellent effects on promoting hair regrowth, preventing or inhibiting hair loss, and the like in human by compounding above-specified phenylacetonitrile derivative as a effective ingredient thereto. One or more mounts and housings may be arrayed on a pipe exterior in modular fashion, for different metering applications. agitated or otherwise brought into contact to produce numerous surface collisions.