226Ra determination

El-Daoushy, M. F. A. F., The determination of 210Pb and 226Ra in lake sediments and dating application, Uppsala, Sweden report UUIP-979 (1976). 

Paytan, A., W.S. Moore and M. Kastner. 1996. Sedimentation rate as determined by 226Ra activity in marine barite. Geochimica et Cosmochimica Acta 60(22) 4313-4319. 

Apparatus and Procedure. Surface Isotherms. The technique for determining the n-A and AV-A curves of the lipid films has been described (6). Briefly, the Wilhelmy plate method was used to measure surface tension, from which the surface pressure was calculated (n = 7h2o—yfiim) The surface potential was measured by means of a radioactive (226Ra) air electrode and a saturated calomel electrode connected to a high impedance model 610 B Keithley electrometer (Keithley Instruments, Cleveland, Ohio). 

Natural Radioactivity Measurement. The naturally occurring radionuclides U(226Ra), Th(232Th), and K(40K) can also be determined on 100-g samples by direct counting of unirradiated samples using anticoincidence shielded multidimensional y-ray spectrometers (29, 30). These spectrometers use large (12 in. diameter X 8 in thick) principal Nal(Tl)... 

Benkhedda, K., Lariviere, D., Scott, S., and Evans, D., Hyphenation of flow-injection preconcentration and ICP-MS for the rapid determination of 226ra in natural waters,./. Anal. At. Spectrom., 20, 523-528, 2005. 

The half-life of radium 226 makes its abundance in the upper layers of ocean sediments, which settled within the past 10,000 years (Holocene epoch), convenient to measure. A comparison of 226Ra abundance to 228Ra in various ocean locations allows for determination of ocean current directional flow Because 228Ra is produced more strongly in shallow areas, and its lifetime is so much shorter, observation of radium 228 far from shore can indicate offshore currents that are otherwise difficult to measure. 

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