7.  Intangible Assets

 

The Company recorded amortization expense of $0.1 million for each of the three and six months ended September 30, 2015. The Company recorded amortization expense of $0.1 million and $0.3 million for the three and six months ended September 30, 2014, respectively. Intangible assets consisted of the following (in thousands):

 

 

 

Expected future amortization expense of intangible assets as of September 30, 2015 is as follows (in thousands):

 

 

The manufacturing license provides the Company with the ability to manufacture recuperator cores previously purchased from Solar Turbines Incorporated (“Solar”). The Company is required to pay a per-unit royalty fee over a seventeen-year period for cores manufactured and sold by the Company using the technology. Royalties of approximately $7,000 and $19,000 were earned by Solar for the three months ended September 30, 2015 and 2014, respectively. Royalties of approximately $19,200 and $33,700 were earned by Solar for the six months ended September 30, 2015 and 2014, respectively. Earned royalties of approximately $7,000 and $19,300 were unpaid as of September 30, 2015 and March 31, 2015, respectively, and are included in accounts payable and accrued expenses in the accompanying balance sheets.