NATIONAL SCIENCE FOUNDATION 



WASHINGTON, D.C. 20550 



OFFICIAL BUSINESS 

 PENALTY FOR PRIVATE USE S300 



RETURN THIS COVER SHEET TO ROOM 233. IF YOU DO 

 NOT WISH TO RECEIVE THIS MATERIAL D , OR IF 

 CHANGE OF ADDRESS IS NEEDED Q , INDICATE 

 CHANGE. INCLUDING ZIP CODE ON THE LABEL (DO 

 NOT REMOVE LABEL). 



NSF 89-98 



