Electric vehicle standardization across platforms, models and manufacturers. Swapping also requires many times more battery packs to be in the system. According to Department of Energy research conducted at Pacific Northwest National Laboratory, 84% of existing vehicles could be switched over to plug-in hybrids without requiring any new grid infrastructure. In terms of transportation, the net result would be a 27% total reduction in emissions of the greenhouse gases carbon dioxide, methane, and nitrous oxide, a 31% total reduction in nitrogen oxides, a slight reduction in nitrous oxide emissions, an increase in particulate matter emissions, the same sulfur dioxide emissions, and the
Sulfur hexafluoride the gas's large molar mass. Unlike helium, which has a molar mass of about 4 grams/mol and gives the voice a childish and a "chipmunk like" quality, has a molar mass of about 146 g/mol, and the speed of sound through the gas is about 134 m/s at room temperature, giving the voice a "demonic" quality when is inhaled. For comparison, the molar mass of air, which is about 80% nitrogen and 20% oxygen, is approximately 30 g/mol which leads to a speed of sound of 343 m/s. Sulfur hexafluoride has an anesthetic potency slightly lower than nitrous oxide. Sulfur