(19)

(11)

EP 0 144 421 A1

(12)

(43) Date of publication: 19.06.1985 Bulletin 1985/25 (21) Application number: 84902567.0 (22) Date of filing: 13.06.1984

(51) International Patent Classification (IPC):  B03D 1/ 02( . ) B03D 1/ 24( . ) (86) International application number: PCT/US1984/000926 (87) International publication number: WO 1985/000021 (03.01.1985 Gazette 1985/01)

(84) Designated Contracting States: AT BE CH DE FR GB LI LU NL SE (30) Priority: 16.06.1983 US 19830504793 (71) Applicant: BOARD OF CONTROL OF MICHIGAN TECHNOLOGICAL UNIVERSITY Houghton, Michigan 49931 (US)	(72) Inventor: YANG, David, C. Houghton, MI 49931 (US) (74) Representative: Corin, Christopher John, et al  Mathisen Macara & Co. The Coach House 6-8 Swakeleys Road Ickenham Uxbridge UB10 8BZ Ickenham Uxbridge UB10 8BZ (GB)