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  • Author or Editor: R. Hartwig x
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The notion of subscripted variable leads to several complications in computer science. Our aim is to clarify this notion in a mathematically proper way. In this paper languages with subscripted variables are considered as certain two-sorted Peano-algebras; semantics and substitution are treated on this foundation. The Hoare axiom for assignments to subscripted variables is derived as an example for application of this algebraic approach.

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Authors: D. Robertson, A. Schilk, K. Abel, E. Lepel, C. Thomas, S. Pratt, E. Cooper, P. Hartwig and R. Killey


In order to more accurately predict the rates and mechanisms of radionuclide migration from lowlevel waste disposal facilities via groundwater transport, ongoing studies are being conducted at field sites at Chalk River Laboratories to identify and characterize the chemical speciation of mobile, long-lived radionuclides migrating in groundwaters. Large-volume water sampling techniques are being utilized to separate and concentrate radionuclides into particulate, cationic, anionic, and nonionic chemical forms. Most radionuclides are migrating as soluble, anionic species which appear to be predominately organoradionuclide complexes. Laboratory studies utilizing anion exchange chromatography have separated several anionically complexed radionuclides, e.g.,60Co and106Ru, into a number of specific compounds or groups of compounds. Large-volume ultra-filtration experiments have shown that significant fractions of the radionuclides are being transported in these groundwaters in the form of macromolecules having molecular weights ranging from less than 3,000 to 100,000.

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