Escapement techniques used escapements, but these have only the name in common. The Chinese one worked intermittently; the European, in discrete but continuous beats. Both systems used gravity as the prime mover, but the action was very different. In the mechanical clock, the falling weight exerted a continuous and even force on the train, which the escapement alternately held back and released at a rhythm constrained by the controller. Ingeniously, the very force that turned the scape wheel then slowed it and pushed it part of the way back... In other words, a unidirectional force produced a self-reversing action—about one step
Controlled internal drug release Controlled internal drug release Controlled internal drug release (CIDR) devices are used in livestock for the synchronization of estrus. They are T-shaped devices with a silicone-coated nylon core. The silicone coating is impregnated with progesterone. CIDRs are inserted intra-vaginally using a specialized applicator. The flexible wings collapse for facilitated insertion and expand once placed appropriately within the vagina. The expansion of the wings retains its position; CIDRs have very high retention rates that may exceed 97%. A thin nylon tail remains exteriorized and is used for removal. Once inserted, CIDRs provide slow-release administration of progesterone, which artificially extends the luteal