To make white sugar, sulfur dioxide is added to cane juice before it gets evaporated. This gas does the bleaching of the juice so that it does not turn brown and produces white sugar. At later stages, phosphoric acid, calcium hydroxide or carbon dioxide is added to absorb impurities.
The first REM sleep period usually occurs about 70 to 90 minutes after we fall asleep. A complete sleep cycle takes 90 to 110 minutes on average. The first sleep cycles each night contain relatively short REM periods and long periods of deep sleep.
âYou can never quite make it up,â she says. Adults aged 18 to 64 need to sleep for seven to nine hours a night, but some cope on six. For people over the age of 65, the recommended amount is between seven and eight hours, although some survive on five hours sleep (often waking up earlier and napping during the day).