Hormonal contraception is highly effective: when taken on the prescribed schedule, users of steroid hormone methods experience pregnancy rates of less than 1% per year. Perfect-use pregnancy rates for most hormonal contraceptives are usually around the 0.3% rate or less.
A programmable logic controller (PLC), or programmable controller is an industrial digital computer which has been ruggedised and adapted for the control of manufacturing processes, such as assembly lines, or robotic devices, or any activity that requires high reliability control and ease of programming and process fault diagnosis.
A business structure used in Europe and Canada, in which shareholder responsibility for company debt is limited, usually to the amount he/she has invested in the company. In some cases, the liability of shareholders is limited to specific pre-determined amounts (which are stated in a memorandum). Abbreviated Ltd or plc.