Inert gas asphyxiation lacks oxygen and consists of an asphyxiant gas (one or more of argon, nitrogen or carbon dioxide), causing the animals to lose consciousness. Argon and nitrogen are important components of a gassing process which seem to cause no pain, and for this reason many consider some types of controlled atmosphere killing more humane than other methods of killing. However, "stunning" is often done using carbon dioxide. If carbon dioxide is used, controlled atmosphere killing is not the same as inert gas asphyxia, because carbon dioxide at high concentrations (above 5%) is not biologically inert, but rather is toxic and also
Shale gas in the United States in Illinois, Indiana, and Kentucky. The New Albany has been a gas producer in this area for more than 100 years, but recent higher gas prices and improved well completion technology have increased drilling activity. Wells are 250 to deep. The gas is described as having a mixed biogenic and thermogenic origin. As of 2007, operators had completed approximately 50 wells in the Pearsall Shale in the Maverick Basin of south Texas. The most active company in the play has been TXCO Resources, although EnCana and Anadarko Petroleum have also acquired large land positions in the basin. The gas wells