Radium and radiocarbon in Caribbean waters

Applications of PB-210/RA-226 and PO-210/PB-210 disequilibria in the study of marine geochemical processes

“…The standard error for predicting Ra from Si, based on the variance about the regression, is in the range 0.8-1.0 dpm/100 kg (5-10% of the predicted value). The Ra-226 activity estimated for deep water of the Venezuelan Basin (Me-32-12) is 11.8 dpm/100 kg and compares very well with the value of 12.2 dpm/100 kg measured by Szabo et al (1967). In addition, values estimated for Me-32-8 are in excellent agreement with their results for stations north of the Greater Antilles.…”

Applications of PB-210/RA-226 and PO-210/PB-210 disequilibria in the study of marine geochemical processes

“…For each of the stations a linear relationship between Ra-226 and Si is defined, and all of the correlations for the individual stations are significant at a confidence level greater than 99%. Linear regression coefficients and y-intercepts along with their 95% confidence limits are summarized in Table III 12.2 dpm/100 kg measured by, Szabo et al• (1967). In addition, values estimated for Me-32-8 are in excellent agreement with their results for stations north of the Greater Antilles.…”

Hopping-Conduction Energy of Holes in SiO2 Determined Accurately by Molecular Orbital Calculation

“…Our calculation indicatedthat one of the 2plonepairwithin MO ofoxygen (O (5) in Fig. 1(a)) was occupied by only one electron, which meansthat the oxygenatom was occupiedby a hole.…”

“…1(a)) was occupied by only one electron, which meansthat the oxygenatom was occupiedby a hole. The length of the Si-O bonds affer hole-trapping (Si(2)-O (5) and Si(3)-O(5)) was estimated as 1.8 A, whichwas 10% longer than that ofthe other Si-O bonds. These results agreed well with those reported previously [3].…”

“…In the case ofthe vacancy-free SiO2 cluster, the hole moved from one oxyge,n atom (O (5) in Fig. 1(a)) to another oxyge,lr atom (O(4), as schematically shownin Fig.…”