This will vary from place to place, the American Red Cross only lets you donate once every 28 days. Private centers will let you donate up to twice in 7 days with at least one day in between. Thatâs how they come up with figures like âmake $300 a monthâ from donating plasma.
Within this layer, temperature increases as altitude increases (see temperature inversion) ; the top of the stratosphere has a temperature of about 270 K (â3 Â°C or 26.6 Â°F), just slightly below the freezing point of water.he stratosphere is layered in temperature because ozone (O 3) here absorbs high energy ultraviolet (UVB and UVC) radiation from the Sun and is broken down into the allotropes of atomic oxygen (O 1) and common molecular oxygen (O 2).
The temperature in this layer usually decreases as the height increases up to the top of the mesosphere where the temperature can be as low as - 95 Â°C or even lower. The composition of gases in the atmosphere from the ground to the top of the mesosphere, are almost identical except for water vapor and ozone.he stratosphere extends from 10 kilometers to 50 - 55 kilometers above ground. Within the lower part which extends from the top of the troposphere to about 30-35 kilometers the temperature is almost constant, or increases slightly with height.