Note 9 - Significant Customers / Concentration / Disaggregated Revenue (Tables)

3 Months Ended

Mar. 31, 2019

Notes Tables

Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Table Text Block]

	For the Three Months Ended March 31 ,
	201 9		201 8
United States and Canada	$	113,059	$	109,225
Australia		62,113		200,303
South America		319,528		3,428
Asia		1,239,113		817,601
Europe		5,687,385		1,260,825
	$	7,421,198	$	2,391,382

Reconciliation of Revenue from Segments to Consolidated [Table Text Block]

	For the Three Months Ended March 31 ,
	201 9		201 8
Ceramic diesel particulate	$	2,243,268	$	1,770,493
Liquid filters and systems		5,040,333		463,277
Development projects		137,597		157,612
	$	7,421,198	$	2,391,382