Construction of Mass Concrete Structure Utilizing Ground Settlement from Underpass Construction in the 2nd Phase Kansai International Airport Project

The man-made island of Kansai International Airport is located 5 km offshore in Osaka bay and the water depth at the point is about 20 m. Thickness of the sediments beneath the island is several hundred meters, including 20 m of very soft Holocene clay layer. Huge amount of soil had been reclaimed layer over layer and the total thickness is up to 34 to 45 m. Therefore, large amount of settlement is inevitable and the average settlement forecast in the 2nd phase island over the 60 years period from the start of reclamation work is 18 m. In this paper, design and construction of 2nd phase underpass structure is discussed. The overview of construction of the airport island and settlement prediction is described first, then the idea of constructing the under water level structure while it was still above water level is introduced. The design concept of following the large displacement and method of displacement prediction is described next and verification with survey and evaluation is concluded at last

Update on the Keio collection of Escherichia coli single-gene deletion mutants

The Keio collection (Baba et al, 2006) has been established as a set of single‐gene deletion mutants of Escherichia coli K‐12. These mutants have a precisely designed deletion from the second codon from the seventh to the last codon of each predicted ORF. Further information is available at http://sal.cs.purdue.edu:8097/GB7/index.jsp or http://ecoli.naist.jp/. The distribution is now being handled by the National Institute of Genetics of Japan (http://www.shigen.nig.ac.jp/ecoli/pec/index.jsp). To date more than 4 million samples have been distributed worldwide. As we described earlier (Baba et al, 2006), gene amplification during construction is likely to have led to a small number of mutants with genetic duplications

Mechanical strength of beryllide pebbles at high temperatures as advanced neutron multipliers

Beryllium intermetallic compounds (beryllides) are an attractive material for advanced neutron multiplier for a demonstration fusion reactor owing to their lower swelling at neutron irradiation environment as well as lower reactivity with water vapor at high temperature. These are supposed to be loaded in a blanket system as pebble types, which have been successfully fabricated by granulation of plasma sintered beryllides rods by a rotating electrode process (REP) by the authors group at Rokkasho Fusion Institute, QST in Japan. It may be anticipated that in a worst case that collapse strength of beryllide pebbles is too low, those may be broken by either vibration or gas pressure and fallen down to bottom area via cavity among pebbles, which may lead to problematic issues such as gas pressure drop and loss of tritium breeding ratio and so on. Since the beryllide pebbles are exposed at various temperature ranges while temperature distribution can be generated due to decay heat and cooling system in the blanket area, it is considerably important to clarify the strength of pebbles at high temperatures. However, few report on collapse strength of beryllide pebbles at not only room temperature but high temperature ranges found whereas many data on the strength of beryllide blocks at high temperature for refractory applications reported.In this study, collapse strength of beryllide pebbles at high temperatures will be presented with cross-section SEM observation result to clarify the strength of beryllide pebbles.第19回核融合炉材料国際会議 (ICFRM-19