630 research outputs found
Male genitalic asymmetry: the case of Onthophagus praestans Péringuey, 1901 (Coleoptera: Scarabaeidae)
The afrotropical 24th and 28th Onthophagus species groups of d’Orbigny (Coleoptera: Scarabaeidae)
Surface blistering and flaking of sintered uranium dioxide samples under high dose gas implantation and annealing
International audienceHigh helium contents will be generated within minor actinide doped uranium dioxide blankets which could be used in fourth generation reactors. In this framework, it is essential to improve our understanding of the type of damage which a pellet could incur as a result of extensive helium build-up. This paper is an attempt at tackling this issue. Sintered uranium dioxide disks have been implanted with helium ions then annealed at various temperatures. Above a concentration of 0.4 at.% and above 1000°C, optical images of the sample surface revealed swollen grains and extensive areas which have exfoliated. Nuclear reaction microanalyses and atomic force microscopy observations were performed to demonstrate that helium has substantially precipitated within the swollen grains. Massive precipitation of the gas leads under these conditions to sample surface blistering which appears to precede flaking. Deuterium ion irradiations have also been performed at ambient and a direct flaking of the sample surface was observed, but for this phenomenon to be observed required much higher doses than in the He study, indicating that temperature could be an essential ingredient for gas to migrate and cause extensive precipitation. Such phenomena could possibly lead to degradation of the fuel
Alpi e patrimonio industriale : cultura e memoria, XIX-XX sec. = Alpes et patrimoine industriel : culture et mémoire, XIXe-XXe siècles = Alpen und industrielles Erbe : Kultur und Erinnerung, 19.-20. Jahrhundert
Cosa racconta il passato industriale delle Alpi? I vari studi contenuti in questo volume si interrogano su differenze e similitudini della patrimonializzazione dell’industria rispetto all’evoluzione della memoria e della costruzione patrimoniale promossa in questi ultimi decenni nel mondo alpino
Redeveloping Derelict and Underused Historic City Areas: Evidence from a Survey of Real Estate Developers
Empirical Analysis of National Income and So2 Emissions in Selected European Countries
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