What does TKN stand for?

What does TKN mean?

TKN	Total Kjeldahl Nitrogen Academic & Science » Physics
TKN	Trade Knowledge Network Business » Firms
TKN	Thermotrex Corporation Business » AMEX Symbols
TKN	Tokuno Shima, Japan Regional » Airport Codes
TKN	Teens Kickin Nicotine Community » Non-Profit Organizations
TKN	TouchKey Network Business » Firms
TKN	The Kristina Network Miscellaneous » Funnies
TKN	The Knowledge Network of Greater Omaha Business » Firms
TKN	Total Kjeldahl Nitrogen Academic & Science » Chemistry