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v3.25.1

Note 11 - Business Segment and Geographic Financial Data - Reporting Segment Net Sales and Gross Margin (Details) - USD ($) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2025 | Mar. 31, 2024
Revenues from external customers | $ 6,382 | $ 4,957
Cost of sales | (3,423) | (2,928)
Gross margin | 2,959 | 2,029
Selling, general and administrative | (3,341) | (3,345)
Research and development | (570) | (376)
Operating income (loss) from operations | (952) | (1,692)
Air Pollution Control [Member] |  |
Revenues from external customers | 1,303 | 2,318
Cost of sales | (878) | (1,428)
Gross margin | 425 | 890
Selling, general and administrative | 0 | 0
Research and development | 0 | 0
Operating income (loss) from operations | 425 | 890
FUEL CHEM [Member] |  |
Revenues from external customers | 5,079 | 2,639
Cost of sales | (2,545) | (1,500)
Gross margin | 2,534 | 1,139
Selling, general and administrative | 0 | 0
Research and development | 0 | 0
Operating income (loss) from operations | 2,534 | 1,139
Other Operating Segment [Member] |  |
Revenues from external customers | 0 | 0
Cost of sales | 0 | 0
Gross margin | 0 | 0
Selling, general and administrative | (3,341) | (3,345)
Research and development | (570) | (376)
Operating income (loss) from operations | $ (3,911) | $ (3,721)

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