Redeemable Preferred Stock	12 Months Ended
Dec. 31, 2015
Redeemable Preferred Stock
Redeemable Preferred Stock	12. Redeemable Preferred Stock On May 8, 2013, the Company entered into a Securities Purchase Agreement with Air Liquide, pursuant to which the Company agreed to issue and sell 10,431 shares of the Company's Series C Redeemable Convertible Preferred Stock, par value $0.01 per share, for an aggregate purchase price of approximately $2.6 million (Euro 2 million) in cash. On August 26, 2014, Air Liquide acquired 5,521,676 shares of Common Stock by converting 5,200 shares of Series C Preferred Stock at the conversion price of $0.2343. Following the conversion, Air Liquide continues to own 5,231 shares of Series C Preferred Stock. The holder of these shares is entitled to designate one director to the Company's Board of Directors. The Series C Preferred Stock ranks senior to the Common Stock with respect to rights upon the liquidation, dissolution or winding up of the Company. In the event of any voluntary or involuntary liquidation, dissolution or winding up of the Company, or other deemed liquidation event, as defined in the Securities Purchase Agreement, the holder of the Series C Preferred Stock will be entitled to be paid an amount per share equal to the greater of (i) the original issue price, plus any accrued but unpaid dividends or (ii) the amount per share that would have been payable had all shares of the Preferred Stock been converted to shares of common stock immediately prior to such liquidation event. The Series C Preferred Stock may not be redeemed by the Company until May 8, 2016. After this date, the Series C Preferred Stock is redeemable at the election of the holder of the Series C Preferred Stock or the Company. The holder of the Series C Preferred Stock is entitled to receive dividends at a rate of 8% per annum, based on the original issue price of $2,595,400, payable in equal quarterly installments in cash or in shares of Common Stock, at the Company's option. During the years ended December 31, 2015, 2014 and 2013 dividends have been paid in the form of shares of Common Stock. The Series C Preferred Stock is convertible into shares of Common Stock with the number of shares of Common Stock issuable upon conversion determined by dividing the original issue price of $2,595,400 by the conversion price in effect at the time the shares are converted. The conversion price of the Series C Preferred Stock as of December 31, 2015 and 2014 was $0.2343. The Series C Preferred Stock votes together with the Common Stock on an as-converted basis on all matters.

12. Redeemable Preferred Stock

On May 8, 2013, the Company entered into a Securities Purchase Agreement with Air Liquide, pursuant to which the Company agreed to issue and sell 10,431 shares of the Company's Series C Redeemable Convertible Preferred Stock, par value $0.01 per share, for an aggregate purchase price of approximately $2.6 million (Euro 2 million) in cash. On August 26, 2014, Air Liquide acquired 5,521,676 shares of Common Stock by converting 5,200 shares of Series C Preferred Stock at the conversion price of $0.2343. Following the conversion, Air Liquide continues to own 5,231 shares of Series C Preferred Stock. The holder of these shares is entitled to designate one director to the Company's Board of Directors. The Series C Preferred Stock ranks senior to the Common Stock with respect to rights upon the liquidation, dissolution or winding up of the Company. In the event of any voluntary or involuntary liquidation, dissolution or winding up of the Company, or other deemed liquidation event, as defined in the Securities Purchase Agreement, the holder of the Series C Preferred Stock will be entitled to be paid an amount per share equal to the greater of (i) the original issue price, plus any accrued but unpaid dividends or (ii) the amount per share that would have been payable had all shares of the Preferred Stock been converted to shares of common stock immediately prior to such liquidation event. The Series C Preferred Stock may not be redeemed by the Company until May 8, 2016. After this date, the Series C Preferred Stock is redeemable at the election of the holder of the Series C Preferred Stock or the Company.

The holder of the Series C Preferred Stock is entitled to receive dividends at a rate of 8% per annum, based on the original issue price of $2,595,400, payable in equal quarterly installments in cash or in shares of Common Stock, at the Company's option. During the years ended December 31, 2015, 2014 and 2013 dividends have been paid in the form of shares of Common Stock. The Series C Preferred Stock is convertible into shares of Common Stock with the number of shares of Common Stock issuable upon conversion determined by dividing the original issue price of $2,595,400 by the conversion price in effect at the time the shares are converted. The conversion price of the Series C Preferred Stock as of December 31, 2015 and 2014 was $0.2343. The Series C Preferred Stock votes together with the Common Stock on an as-converted basis on all matters.