&
’
DISCLAIMER
This report was prepared as an account of work sponsored byan agencyof the United
States Government. Neither the United States Government nor anyagencythereof,
nor anyof their employees, nor anyof their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes anvlegal liability or re-
sponsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe pri-
vately owned rights. Reference herein to anyspecific commercial product, process. or
service by trade name, trademark, manufacturer, or otherwise, does not necessarily
constitute or imply its endorsement, recommendation, or favoring by the United
States Government or any agency, contractor or subcontractor thereof The views and
opinions of authors expressed herein do not necessarilystate or reflect those of the
United States Government or any agency, contractor or subcontractor thereof.
Printed in the United States ofAmerica
Available from
National Technical Information Service
U.S. Department of Commerce
5285 Port Royal Road
Springfield, VA 22161
Price: Printed Copy $7.00; Microfiche $3.50