Intangible assets consist of the following (dollars in thousands): DECEMBER 31,2003 DECEMBER 31,2002 AVERAGE LIFE GROSS CARRYING ACCUMULATED GROSS CARRYING ACCUMULATED (YEARS) AMOUNT AMORTIZATION AMOUNT AMORTIZATION Amortizable intangible assets: Patents 12.85 $ 9,250 $ 7,151 $ 9,250 $ 6,847 Intangible assets not subject to amortization: Goodwill $ 9,730 — $ 9,730 — Aggregate amortization expense for patents and goodwill was $304,000, $304,000 and $907,000 for 2003, 2002 and 2001, respectively. Estimated future amortization expense for each of the years ending December 31, is as follows (in thousands): 2004 $ 304 2005 $ 271 2006 $ 169 2007 $ 144 2008 $ 144 There was no change in the carrying amounts of goodwill for 2003. During 1997, the Company sold all of its natural gas operations. The consolidated financial statements presented herein reflect the Company’s natural gas operations as discontinued operations for all periods presented. The consolidated financial statements reflect a gain on disposal of these discontinued operations of $165,000 in 2003 and 2002, and $5.5 million in 2001. These amounts are net of income tax expense of $85,000 in 2003 and 2002, and include an income tax benefit of $5.1 million in 2001.  In addition to the initial consideration received in 1997 upon the sale of the natural gas operations, certain annual contingent deferred payments of up to $250,000 per year were to be paid to the Company over an eight-year period which began in 1999, with the amount paid each year to be dependent upon revenues received by the purchaser from certain gas transportation contracts. The Company received deferred payments of $250,000 each, before tax, from the purchaser in April 2003, 2002 and 2001 which are reflected in each year as a gain from discontinued operations of $165,000, net of tax. The 2001 gain also includes a $5.3 million non-cash gain from reversal of a reserve established when the Company disposed of its natural gas operations in 1997. This reversal in the third quarter of 2001 followed the resolution of an outstanding contingency related to the sale of those assets.  The Company has a revolving credit facility (“Credit Facility”) with a regional bank. In December 2001, the Credit Facility arrangement was amended to increase the credit line under the Credit Facility from $18.5 million to $25.0 million. Under the Credit Facility, the Company and certain of its subsidiaries have a line of credit which is secured by substantially all inventory, equipment and accounts receivable of the Company. Interest under the Credit Facility is assessed at 30-day, 60-day or 90-day LIBOR, as selected by the Company, plus one percent (2.17 percent at December 31, 2003) and is payable monthly. At December 31, 2003, and 2002, $4.3 million and $10.3 million, respectively, was outstanding under the line of credit. The Credit Facility expires November 12, 2006, and may be extended under certain circumstances. At any time during the term, the Company may convert any or all outstanding amounts under the Credit Facility to a term loan with a maturity of two years. The Company’s ability to borrow funds under the Credit Facility from time to time is contingent on meeting certain covenants in the loan agreement, the most restrictive of which is the ratio of total debt to earnings before interest, income tax, depreciation and amortization. At December 31, 2003, the Company was in compliance with all financial covenants. DISCONTINUED OPERATIONS 3 LINE OF CREDIT 4 15