one of a group of cells that develop in the walls of the seminiferous tubules. Spermatogenic cells include spermatogonia, spermatocytes, and spermatidsâall of which are transitional forms between primary sexual cells and spermatozoa.
long-haul optics. Long-haul optics refers to the transmission of visible light signals over optical fiber cable for great distances, especially without or with minimal use of repeaters. Normally, repeaters are necessary at intervals in a length of fiber optic cable to keep the signal quality from deteriorating to the point of non-usability. In long-haul optical systems, the goal is to minimize the number of repeaters per unit distance, and ideally, to render repeaters unnecessary.
Hemp Fiber. Hemp is traditionally known as a fiber plant and most historical cultivation of the plant in the United States from the 17th to mid-20th centuries was with fiber use in mind. Two kinds of fibers are derived from the hemp plantâs stalk.These are long (bast) fibers and the short (core fibers).hen grown as a fiber crop, hemp grows to a height of 6-12 feet without branching. Dense plantings (as many as 300 plants per square yard) help ensure that the plant grows straight. An ideal sized fiber plant has the same diameter as a #2 pencil (about Â¼ inch or 6 mm).