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.
Sleep And Aging. Older adults need about the same amount of sleep as young adultsâ7 to 9 hours each night. But seniors tend to go to sleep earlier and get up earlier than when they were younger. Older people may nap more during the day, which can sometimes make it hard to fall asleep at night. There are two kinds of sleepâREM (rapid eye movement) sleep and non-REM sleep. We dream mostly during REM sleep and have the deepest sleep during non-REM sleep.