Escapement spring made accurate timepieces possible, it has been estimated that more than three hundred different mechanical escapements have been devised, but only about 10 have seen widespread use. These are described below. In the 20th century, electric timekeeping methods replaced mechanical clocks and watches, so escapement design became a little-known curiosity. The earliest mechanical escapement from about 1275) was the verge escapement, also known as the crown-wheel escapement. It was used in the first mechanical clocks and was originally controlled by a foliot, a horizontal bar with weights at either end. The escapement consists of an escape wheel shaped somewhat
Controlled internal drug release by AHI Plastic Moulding Company in Hamilton, New Zealand, in conjunction with the Ministry of Agriculture and Forestry (New Zealand). Developmental trials began in 1981. The CIDR-S was licensed in 1986 and the CIDR-G in 1988. 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