194 FOOTE 0.7 0.6 2 ts | i | | eS Ny MATRIX AMOUNT - o 1500 _ a Poy ot thI MC/SQ MILE ILE— | | | 7 | | | wane ee ee 0.5 I | L i f ! t t { { | } i : | I | | 1 i | 1 ' Q.1 DEC JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL 1963 1964 FIELD INTENSITY, MC/SQ MILE Fig, 13—Praseodymium-l4i effective suitace amounts as a function of time, 11 by 11 matrix reduction. 300 fF a Th ce ences _ _— ee tee ee nae 200 panes ok ope wm ee — Bho ~ . we eee. ee 1 Pn a 7 a _ _ _ 4 ! Fr * [oh La AMOUNTS AS A FUNCTION OF TIME +— we wot + 100 ' ya je — — to tot : *y. _ ‘a _——t iT . namaeeanns $ oy L { — Joi ah oo PT ph tS * _ : ~ ry : oe ‘eit dod + T . tal bob aoa DEC JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL 1963 1964 Fig. lo—Lanthanum-140 effective surface amounts as a function of time, li by Il inatrix reduction.