Here, the hypothesis is that human-related emissions of CO2 are the cause of the rise in atmospheric CO2. They used nanotubes that were particularly small — more than 50, times thinner than a human hair.
The recent history of atmospheric CO2, derived from the Mauna Loa observations back to and ice core data back to shows a dramatic increase beginning in the late s, at the onset of the Industrial Revolution. Because of this concern, there is a tremendous effort underway to better understand the global carbon cycle.
For example, it is believed that natural climate excursions, along with other factors, contributed to the end of the Anasazi and Mayan civilizations in the southwestern United States and Central America Diamond, ; Tainter, Carbon has a half-life of 5, years, meaning that after that time, half of the carbon in a sample decays away, according to the University of Arizona.
Topics covered include the mechanisms of formation of isotropic and anisotropic carbons, physical properties of pitch relevant to the fabrication of carbon materials; kinetics and catalysis of carbon gasification; and porosity in carbons and graphites.
Although carbon decays into nitrogen through beta decaythe amount of carbon in the environment remains constant because new carbon is always being created in the upper atmosphere by cosmic rays. Although commonly called leadthe black material used in pencils is actually graphite.
In the nanotube study, the scientists mimicked the way biological membranes are structured: essentially a matrix with pores inside the membrane.