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Irradiation tests are carried out in view of selecting the cryogenic temperature sensors for use in the RIKEN Superconducting Ring Cyclotron (SRC). The cryogenic temperature sensors namely, Cernox(super TM), CGR and PtCo, at room temperature are bombarded by the intense 210 MeV proton beam at the RIKEN Accelerator Research facility of RIKEN.

Three types of cavitation instabilities through flat plate cascades, which are similar to 'forward rotating cavitation,' 'rotating-stall cavitation' and 'cavitation surge' occurring in high-speed rotating fluid machinery, are represented numerically under the three-blade cyclic condition. A numerical method employing a locally homogeneous model of compressible gas-liquid two-phase medium is applied to solve the above flow fields, because this permits the entire flow field inside and outside the cavity to be treated through only one system of governing equations. In addition, the numerical method suites to analyze unsteady cavitating flow with a long time evolution. From the calculated results of the present numerical simulation with wide range of cavitation number and flow rate, we obtain a cavitation performance curve of the present three-blade cyclic cascade, analyze the aspects of unsteady cavitation, and discuss the characteristics and mechanisms of cavitation. [DOI: 10.1115/1.1760539]

We have previously identified and characterized Drosophila hemolectin (Hml) in the conditioned medium of a Drosophila cell line. The deduced amino acids sequence contains a number of domains conserved in human von Willebrand factor, coagulation factor V/VIII, and complement factors. To characterize Hml localization and function, we have established two transgenic lines (hml-GAL4 and UAS-hmlRNAi). By crossing hml-GAL4 with UAS-eGFP, we observed that Hml is specifically expressed in embryonic and in larval hemocytes. We determined that Hml is expressed in a subpopulation of plasmatocytes and crystal cells but not in lamellocytes, hml RNAi larvae are viable and do not display obvious developmental defects under normal conditions. However, they show a bleeding defect upon injury. We confirmed that the failure to seal a wound is not due to a defect in melanin production of in phenoloxidase activity. The expression of amtimicrobial peptides was not significantly affected on hml RNAi adults. Altogether, our data strongly suggest that Hml is involved in hemostasis and/or coagulation in Drosophila larvae. Keywords: Innate immunity; Cellular response; Hemocyte; Hemostasis; RNA interference; von Willebrand factor

Two-dimensional unsteady cavity flow through a cascade of hydrofoils is numerically calculated. Particular attention is focused on instability phenomena of a sheet cavity in the transient cavitation condition, and the mechanism of the breakoff phenomenon is examined. TVD-MacCormack's scheme employing a locally homogeneous model of compressible gas-liquid two-phase medium is applied to analyze the cavity flows. The present method permits us to treat the entire cavitating/noncavitating unsteady flowfield. By analyzing the numerical results in detail it becomes clear that there are at least two mechanisms in the breakoff phenomenon of the sheet cavity: one is that re-entrant jets play a dominant role in such a breakoff phenomenon, and the other is that pressure waves propagating inside the cavity bring about another type of breakoff phenomenon accompanying with cavity surface waves. [DOI: 10.1115/1.1596239]

A new approach to optimizing a pump diffuser is presented, based on a three-dimensional inverse design method and a Computational Fluid Dynamics (CFD) technique. The blade shape of the diffuser was designed for a specified distribution of circulation and a given meridional geometry, at a low specific speed of 0.109 (non-dimensional) or 280 ([m.sup.3]/min, m, rpm). To optimize the three-dimensional pressure fields and the secondary flow behavior inside the flow passage, the diffuser blade was more fore-loaded at the hub side as compared with the casing side. Numerical calculations, using a stage version of Dawes three-dimensional Navier-Stokes code, showed that such a loading distribution can suppress flow separation at the corner region between the hub and the blade suction surface, which was commonly observed with conventional designs having a compact bowl size (small outer diameter). The improvements in stage efficiency were confirmed experimentally over the corresponding conventional pump stage. The application of multi-color oil-film flow visualization confirmed that the large area of the corner separation was completely eliminated in the inverse design diffuser. [DOI: 10.1115/1.1467599]

A computer-aided design system has been developed for hydraulic parts of pumps including impellers, bowl diffusers, volutes, and vaned return channels. The key technologies include three-dimensional (3-D) CAD modeling, automatic grid generation, CFD analysis, and a 3-D inverse design method. The design system is directly connected to a rapid prototyping production system and a flexible manufacturing system composed of a group of DNC machines. The use of this novel design system leads to a drastic reduction of the development time of pumps having high performance, high reliability, and innovative design concepts. The system structure and the design process of 'Blade Design System' and 'Channel Design System' are presented. Then the design examples are presented briefly based on the previous publications, which included a centrifugal impeller with suppressed secondary flows, a bowl diffuser with suppressed corner separation, a vaned return channel of a multistage pump, and a volute casing. The results of experimental validation, including flow fields measurements, were also presented and discussed briefly. [DOI: 10.1115/1.1471362]

Research is presented describing a superconducting bending magnet for beam injection that is being used in the construction at RIKEN of a K2500 superconducting ring cyclotron with six sectors. The ring cyclotron will be used as an energy booster for RIKEN's existing K540 ring cyclotron.

The construction of a six-sector superconducting ring cyclotron for use as the main post accelerator of the current accelerator complex for the RIKEN RI beam factory is described.

The mechanics of sector magnets for the RIKEN superconducting ring cyclotron are described including design of the main coil vessel.