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 lays the groundwork for a productive day ahead. Although most people need seven to nine hours of sleep each night to function well the next day, the National Sleep Foundation (NSF) 1998 Women and Sleep Poll found that the average woman aged 30-60 sleeps only six hours and forty-one minutes during the workweek.