“…decreased r a p i d l y as a f u n c t i o n o f dose a t fi r s t , b u t a t higher doses the decrease was l e s s rapid. ,However, Looniis and Gerber (43) reported that, p a r t i c u l a r l y f o r higher-oxygen samples, the hardening r a t e increased again for s t i 11 higher doses (above about 2 4 x 1 0 '~ n/cm ), w i t h an attendant f u r t h e r decrease i n i n t e r b a r r i e r spacing. I n vanadium, S h i r a i s h i e t a1 .…”