<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Tent, J</style></author><author><style face="normal" font="default" size="100%">Rauret, G</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Lixiviation as a tool for radionuclide fractionation in holm oak leaves</style></title><secondary-title><style face="normal" font="default" size="100%">JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY-ARTICLES</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Holm oak</style></keyword><keyword><style  face="normal" font="default" size="100%">radionuclide</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1996</style></year></dates><publisher><style face="normal" font="default" size="100%">AKADEMIAI KIADO</style></publisher><pub-location><style face="normal" font="default" size="100%">PO BOX 245, H-1519 BUDAPEST, HUNGARY</style></pub-location><volume><style face="normal" font="default" size="100%">204</style></volume><pages><style face="normal" font="default" size="100%">321-331</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">A sequential extraction scheme, using distilled water and chloroform : hexane(1:2) was applied in a study of radionuclide retention by helm oak leaves. To perform this study, holm oak leaves were contaminated by dry deposition using a thermogenerated radioactive aerosol containing Cs-134, Sr-85 and Ag-110m. The experimental parameters tested were: type and lime of shaking, number of successive extractions in each step, and the volume of extractans. From the results obtained, two schemes which give complementary information about radionuclide retention are proposed. The first scheme, using a single water extraction with mechanical shaking, allows us to define two fractions: the fraction removed by water, which is related to total radionuclide retention on leaf surfaces, and the residual fraction, which is associated with radionuclides incorporated into the leaves. The second scheme is based on a two-step extraction with manual shaking using water and chloroform :hexane, and permits us to distinguish among three fractions:the fraction removed by water(which is related to the radionuclide fraction easily leached by rain), the fraction removed by organic solvent (which is associated with the radionuclide fraction strongly retained on leaf surface), and the residual fraction, which may represent the absorbed radionuclide content. Since our objective was to study the retention of Cs-134, Sr-85 and Ag-110m, simultaneously, the experimental conditions chosen were a compromise of individual suitable conditions for each radionuclide.</style></abstract><notes><style face="normal" font="default" size="100%">APS</style></notes><research-notes><style face="normal" font="default" size="100%">APS</style></research-notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Rauret, G</style></author><author><style face="normal" font="default" size="100%">Llauradó, M</style></author><author><style face="normal" font="default" size="100%">Tent, J</style></author><author><style face="normal" font="default" size="100%">Rigol, A</style></author><author><style face="normal" font="default" size="100%">Alegre, L H</style></author><author><style face="normal" font="default" size="100%">Utrillas, M J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Deposition on holm oak leaf surfaces of accidentally released radionuclides</style></title><secondary-title><style face="normal" font="default" size="100%">Science of The Total Environment</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cuticle thickness</style></keyword><keyword><style  face="normal" font="default" size="100%">Holm oak</style></keyword><keyword><style  face="normal" font="default" size="100%">Leaf surface</style></keyword><keyword><style  face="normal" font="default" size="100%">Radionuclide deposition</style></keyword><keyword><style  face="normal" font="default" size="100%">Radionuclide incorporation</style></keyword><keyword><style  face="normal" font="default" size="100%">Sequential extraction</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1994</style></year></dates><volume><style face="normal" font="default" size="100%">157</style></volume><pages><style face="normal" font="default" size="100%">7-16</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The retention of aerosols by canopies of holm oak trees in a typical Mediterranean forest is studied. Firstly, dry deposition is measured both under and outside the canopy during several months. No clear differences are observed either in the amount or in the chemical composition of the particles collected under and outside the canopy. Secondly, the leaf morphology and anatomy as well as the aerosol deposited onto the leaf surfaces are studied by scanning electron microscopy. Cuticle thickness is measured and differences are observed between young and old leaves. The distribution of aerosol particles over leaf surface is also established. Finally, the possible incorporation into leaves of a radioactive aerosol released in an accidental situation is studied, by means of a sequential extraction procedure using water and an organic solvent. From the results it can be deduced that neither the abiotic layer nor the cuticle play any important role in the retention of caesium. The studied radionuclides are mainly found in particulate form, soluble in water, or incorporated into leaves.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">SAURAS, T</style></author><author><style face="normal" font="default" size="100%">ROCA, M C</style></author><author><style face="normal" font="default" size="100%">Tent, J</style></author><author><style face="normal" font="default" size="100%">Llauradó, M</style></author><author><style face="normal" font="default" size="100%">VIDAL, M</style></author><author><style face="normal" font="default" size="100%">Rauret, G</style></author><author><style face="normal" font="default" size="100%">Vallejo, V R</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">MIGRATION STUDY OF RADIONUCLIDES IN A MEDITERRANEAN FOREST SOIL USING SYNTHETIC AEROSOLS</style></title><secondary-title><style face="normal" font="default" size="100%">SCIENCE OF THE TOTAL ENVIRONMENT</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">litter</style></keyword><keyword><style  face="normal" font="default" size="100%">mediterranean forest</style></keyword><keyword><style  face="normal" font="default" size="100%">RADIONUCLIDE MIGRATION</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1994</style></year></dates><publisher><style face="normal" font="default" size="100%">ELSEVIER SCIENCE BV</style></publisher><pub-location><style face="normal" font="default" size="100%">PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS</style></pub-location><volume><style face="normal" font="default" size="100%">157</style></volume><pages><style face="normal" font="default" size="100%">231-238</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Radionuclide migration in a Mediterranean forest was studied in field conditions. Fresh Holm oak leaves were exposed to a synthetic aerosol including Cs-134, Sr-85 and Ag-110m, and were incubated in the original Holm oak forest in two types of cylinder: (1) cylinders in which the contaminated litter lies directly on the original F layer; (2) cylinders with an exchange resin bag inserted between the contaminated litter and the underlying F layer. The results for 232 days of incubation showed that Cs-134 presented an initial rapid leaching period, which corresponded to the fraction extracted with water from the initially contaminated leaves. Further Cs-134 release was related to litter decompostiion. Sr-85 migration was studied for only 76 days, and its behaviour appeared to be similar to Cs-134. Both radionuclides migrated within the litter leachates. After 3 months of incubation, around 70% of the initial Cs-134 was transferred to the underlying layers, mainly to the F layer. Cs-134 absorbed into the leaves was released at the same rates as K. The Ag-110m activity lost from the contaminated litter amounted to around 45% in the open cylinders, from which 15-20% was attributed to the effect of soil faunal activity. The field method proposed proved to be useful in describing radionuclide migration in situ and the mechanisms involved.</style></abstract></record></records></xml>