Air conditioning eventually reach the upper atmosphere. Once the refrigerant reaches the stratosphere, UV radiation from the Sun homolytically cleaves the chlorine-carbon bond, yielding a chlorine radical. These chlorine radicals catalyze the breakdown of ozone into diatomic oxygen, depleting the ozone layer that shields the Earth's surface from strong UV radiation. Each chlorine radical remains active as a catalyst until it binds with another radical, forming a stable molecule and quenching the chain reaction. Prior to 1994, most automotive air conditioning systems used R-12 as a refrigerant. It was replaced with R-134a refrigerant, which has no ozone depletion potential. Old R-12 systems
High Roller (Stratosphere) High Roller (Stratosphere) The High Roller (also known as the Let it Ride High Roller), was a steel roller coaster constructed on top of a building over the Las Vegas Strip. It was the highest roller coaster in the world when compared to the surrounding terrain. It was located on top of the Stratosphere Tower, Las Vegas, Nevada, which is the tallest free-standing observation tower in the United States. The coaster was manufactured by S&MC GmbH Structures and Machines. The ride opened on April 29, 1996, in a special VIP gala opening, one day before the ride and casino opened