The supercontainer is the reference concept for the post-conditioning of vitrified high-level radioactive waste and spent fuel in Belgium. It comprises a prefabricated concrete buffer that completely surrounds a carbon steel overpack. In this highly alkaline environment (pH ∼13.6) and under normal conditions (i.e. without the ingress of aggressive species), the carbon steel overpack will be protected by a passive oxide film, which is expected to result in very low uniform corrosion rates. Considering the long timescales applicable to waste disposal, determining accurate and reliable estimates of the uniform corrosion rate under anoxic conditions forms a very important part of the safety and feasibility strategy. On the other hand, the occurrence of localised forms of corrosion cannot be neglected and, therefore, it is also crucial to demonstrate that no other form of corrosion apart from uniform corrosion can take place. This paper gives an overview of the status of the research into the uniform corrosion, pitting corrosion and stress corrosion cracking behaviour of P355 QL2 grade carbon steel exposed to an artificial concrete pore water solution.This paper is part of a supplement on the 6th International Workshop on Long-Term Prediction of Corrosion Damage in Nuclear Waste Systems.
Distributed Hash Tables (DHTs) are scalable peer-to-peer systems that support exact match lookups. This paper describes the construction and use of a Prefix Hash Tree (PHT) -- a distributed data structure that supports range queries over DHTs. PHTs use the hash-table interface of DHTs to construct a search tree that is efficient (insertions/lookups take ##### ### #### DHT lookups, where D is the data domain being indexed) and robust (the failure of any given node in the search tree does not affect the availability of data stored at other nodes in the PHT).
The adsorption of acetic acid and of propanoic acid on Ag(111) and Pt(111) single crystal surfaces has been studied with LEED. Both acetic acid and propanoic acid formed two-dimensional structures in two different types of orientation on Ag(111) and propanoic acid apparently formed the same structure on graphite covered Pt(111). Neither acid formed ordered monolayers when adsorbed on clean Pt(111). The similar LEED data and physical properties of the acid molecules suggested similar structures for both acids consisting of closely packed arrays of hydrogen-bonded dimers.
A given set of users share the submodular cost of access to a network (or, more generally, the submodular cost of any idiosyncratic binary good). We compare strategyproof mechanisms that serve the efficient set of users (but do not necessarily balance the budget) with those that exactly cover costs (but are not necessarily efficient). Under the requirements of individual rationality (guarante eing voluntary participation) and consumer sovereignty (an agent will obtain access if his willingness to pay is high enough), we find:
