Note 7 - Disaggregated Revenues and Segment Information - Net Revenue, Classified by Geography (Details) - USD ($)	3 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Net revenues	$ 721,358	$ 569,093
Chemical [Member]
Net revenues	315,257	186,523
Electronics [Member]
Net revenues	222,574	288,062
Engineering [Member]
Net revenues	183,527	94,508
UNITED STATES
Net revenues	639,405	544,427
UNITED STATES | Chemical [Member]
Net revenues	233,304	161,857
UNITED STATES | Electronics [Member]
Net revenues	222,574	288,062
UNITED STATES | Engineering [Member]
Net revenues	183,527	94,508
Non-US [Member]
Net revenues	81,953	24,666
Non-US [Member] | Chemical [Member]
Net revenues	81,953	24,666
Non-US [Member] | Electronics [Member]
Net revenues	0	0
Non-US [Member] | Engineering [Member]
Net revenues	$ 0	$ 0