Flow-control valves. The purpose of flow control in a hydraulic system is to regulate speed. All the devices discussed here control the speed of an actuator by regulating the flow rate. Flow rate also determines rate of energy transfer at any given pressure.
Hooke had discovered plant cells -- more precisely, what Hooke saw were the cell walls in cork tissue. In fact, it was Hooke who coined the term cells: the boxlike cells of cork reminded him of the cells of a monastery.Hooke also reported seeing similar structures in wood and in other plants.o portrait survives of Robert Hooke. His name is somewhat obscure today, due in part to the enmity of his famous, influential, and extremely vindictive colleague, Sir Isaac Newton. Yet Hooke was perhaps the single greatest experimental scientist of the seventeenth century.
The cell was first discovered and named by Robert Hooke in 1663. He remarked that it looked strangely similar to cellula or small rooms which monks inhabited, thus deriving the name. However what Hooke actually saw was the dead cell walls of plant cells also known as cork.