Carbon Equivalent

The equivalent carbon content of a steel alloy refers to method of measuring the maximum hardness and the weldability of the alloy based on the chemical composition of the alloy. Higher concentrations of carbon and other alloying elements such as manganese, chromium, silicon, molybdenum, vanadium, copper, and nickel tend to increase the hardness and decrease the weldability of the material. Each of these materials tends to influence the hardness and weldability of the steel to different magnitudes, however, making a method of comparison necessary to judge the difference in hardness between two alloys made of different alloying elements. The equivalent carbon content is the most common such standard, but others exist, such as the equivalent nickel content and the equivalent chromium content (usually used together and in conjunction with the Schaeffler-Delong diagram and considered more accurate for measuring weldability). A commonly used formula for calculating the equivalent carbon content is:
See more at Wikipedia.org...

A metric measure used to compare the emissions of different greenhouse gases based upon their global warming potential (GWP). Greenhouse gas emissions in the U.S. are most commonly expressed as "million metric tons of carbon equivalents" (MMTCE). Global warming potentials are used to convert greenhouse gases to carbon dioxide equivalents - they can be converted to carbon equivalents by multiplying by 12/44 (the ratio of the molecular weight of carbon to carbon dioxide). The forumula for carbon equivalents is: MMTCE = (million metric tons of a gas) * (GWP of the gas) * (12/44) See greenhouse gas, global warming potential, metric ton, carbon dioxide equivalent.