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Statut |
Confirmé |
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Série |
SEM-BESSON |
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Domaines |
cond-mat |
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Date |
Mardi 10 Avril 2012 |
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Heure |
14:30 |
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Institut |
IMPMC |
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Salle |
Salle de Conférence, couloir 22-23, 4ème ét., UMPMC, 4, Place Jussieu, Paris |
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Nom de l'orateur |
Kroeker |
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Prenom de l'orateur |
Scott |
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Addresse email de l'orateur |
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Institution de l'orateur |
Dept. of Chemistry, University of Manitoba, Winnipeg, Manitoba, Canada, R3T 2N2 |
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Titre |
NMR Studies of Nuclear Waste Materials: Cutting Through Compositional and Morphological Complexity |
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Résumé |
Multinuclear magnetic resonance spectroscopy is used to identify and quantify devitrification products in heterogeneous model nuclear waste materials containing up to 19 oxide components. These complex phase assemblages contain mixed-alkali compounds and substitutionally disordered chromate/molybdates. The presence of paramagnetic ions complicates the NMR analysis but also provides valuable information about the partitioning of species amongst phases. Hydration reactions appear to play a critical role in the formation of some precipitates which may impact the long-term chemical durability of these materials. Circumventing the formation of such phases requires knowledge of the high-temperature behaviour of the melt and the formation mechanisms during cooling. High-temperature magic-angle spinning NMR is used to characterize phase transformations and reactions amongst devitrification products during cooling, under conditions mimicking those of industrial processes and long-term storage. |
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Numéro de preprint arXiv |
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Commentaires |
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Fichiers attachés |
- seminKROEKER2012a.pdf (149564 bytes)
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