INTANGIBLE ASSETS

6 Months Ended

Oct. 31, 2011

Notes to Financial Statements

INTANGIBLE ASSETS

The following table summarizes our intangible assets as of October 31, 2011:

Asset Category	Value Assigned		Weighted Average Amortization Period (in Years)		Impairments		Accumulated Amortization			Carrying Value (Net of Impairments and Accumulated Amortization)
Patents	$	471,918		11.4	$	—	$	(223,221	)	$	248,697
License Rights		523,970		17.1		—		(76,164	)		447,806
Trademarks		134,904		N/A		—		—			134,904
Total	$	1,130,792			$	—	$	(299,385	)	$	831,407

The following table summarizes our intangible assets as of April 30, 2011:

Asset Category	Value Assigned		Weighted Average Amortization Period (in Years)		Impairments			Accumulated Amortization			Carrying Value (Net of Impairments and Accumulated Amortization)
Patents	$	566,564		10.1	$	(202,934	)	$	(214,840	)	$	148,790
License Rights		558,532		17.6		(68,602	)		(63,395	)		426,535
Trademarks		155,134		N/A		(30,508	)		—			124,626
Total	$	1,280,230			$	(302,044	)	$	(278,235	)	$	699,951

For the three months ended October 31, 2011 and 2010, the aggregate amortization expense on the above intangibles was approximately $10,000 and $15,000, respectively.

For the six months ended October 31, 2011 and 2010, the aggregate amortization expense on the above intangibles was approximately $21,000 and $108,000, respectively.

Patents and License Rights—The Company currently holds, has filed for, or owns exclusive rights to, US and worldwide patents covering 13 various methods and uses of our PFC technology. It capitalizes amounts paid to third parties for legal fees, application fees and other direct costs incurred in the filing and prosecution of its patent applications. These capitalized costs are amortized on a straight-line method over their useful life or legal life, whichever is shorter.

Trademarks—The Company currently holds, or has filed for, trademarks to protect the use of names and descriptions of its products and technology. It capitalizes amounts paid to third parties for legal fees, application fees and other direct costs incurred in the filing and prosecution of its trademark applications. These trademarks are evaluated annually in accordance with ASC 350, Intangibles – Goodwill and other. The Company evaluates (i) its expected use of the underlying asset, (ii) any laws, regulations, or contracts that may limit the useful life, (iii) the effects of obsolescence, demand, competition, and stability of the industry, and (iv) the level of costs to be incurred to commercialize the underlying asset.