Design and manufacturing of JT-60SA vacuum vessel

JT-60 is planned to be upgraded to JT-60SA tokamak machine with fully superconducting coils, which is a project of the JA-EU satellite tokamak program under both Broader Approach program and Japanese domestic program. The JT-60SA vacuum vessel (VV) has a D-shape poloidal cross section and a toroidal configuration with 10° facet segmented in toroidal direction. The material of the VV is 316L stainless steel with low cobalt content of <0.05 wt%. A double wall structure is adopted for the VV to ensure high rigidity and high toroidal one-turn resistance simultaneously.Fundamental welding R&D and a trial manufacturing of the 20° upper half of the VV have been performed to study the manufacturing procedure. After the confirmation of the quality of the mock-up, manufacturing of the actual VV started in November 2009.     

Microstructure of a Molybdenum Nitride Layer Formed by Nitriding Molybdenum Metal

For pure molybdenum nitrided at 1373 K in NH₃ gas, microstructural observations of a molybdenum nitride layer were conducted through a transmission electron microscope. The molybdenum nitride layer consisted of two molybdenum nitrides: an outer one of γ-Mo₂N and an inner one of β-Mo₂N. A great number of (011)[0     1] type twins were observed in the β-Mo₂N phase, whereas the microstructure of the γ-Mo₂N phase was almost free from lattice defects except for slightly observed {111}〈112〉 type twin.     

Wireless Body Area Network Combined with Satellite Communication for Remote Medical and Healthcare Applications

Wireless Body Area Network (WBAN) is expected to play an important role in supporting medical and healthcare services with increased convenience and comfort. One main advantage of WBAN is that it enables automatic biosignal collection in real time which is essential in medical treatment and healthcare vigilance. To harmonize with the strong demands from both medical and healthcare societies, and information and communications technology industries, IEEE 802 Standard Committee set up a task group of TG15.6 to develop an IEEE wireless standard on WBAN. In this paper, we first review the main activities of TG15.6 with the updated status. Then, we present a prototype WBAN system that is implemented by using ultra-wideband technology. Multi-hop mechanism is adopted to guarantee reliable connection. Finally, we describe an experimental system that uses the developed WBAN system by combining with satellite communication in supporting remote medical treatment and healthcare. In case of less of medical resources such as in emergency, in rural or isolated areas, such a system is important in sending the corresponding biosignal to a remote hospital in real time to help patient management. The relative delay of WBAN data delivery via satellite is measured which is dependent on the satellite link capacity.     

Lifetime prediction of woven GFRP laminates under constant tensile loading in hydrothermal environment

This study aims to investigate the effects of a hydrothermal environment on the creep behavior of woven glass fiber reinforced plastics (GFRPs) and to propose a method for predicting their lifetime. Toward this end, experiments were carried out in air and deionized water at 40, 60, 80 and 95 ^°C. Static tensile tests of woven GFRP were conducted in air and in deionized water to evaluate its mechanical properties and to determine suitable experimental conditions for subsequent constant tensile load tests. The mechanical properties of the woven GFRP decreased with an increase in temperature and with water immersion. Constant tensile load tests were also conducted in air and in deionized water to investigate the creep behavior and fracture time. The fracture time decreased with an increase in stress and water temperature and demonstrated the possibility of a threshold stress for fracturing. In addition, the fracture time during each constant tensile load test was predicted using a modified Reiner–Weissenberg (R-W) criterion, which is a failure criterion for linear viscoelastic materials based on the accumulation of dissolved energy within the GFRP. In this study, the R-W criterion was modified to consider the effects of degradation and its acceleration, which are due to the applied stress and immersion in a solution. The predicted results were in good agreement with the experimental data when considering the effects of hydrothermal aging.     

Growth and differentiation potentials in confluent state of culture of human skeletal muscle myoblasts

The transitional behaviors of myoblasts toward differentiation were investigated in the cultures at the low and high seeding densities (respectively, X₀ = 1.0 × 10³ and 2.0 × 10⁵ cells/cm²). In the culture at the low seeding density, an increase in confluence degree accompanied a decrease in growth potential (R_p), being R_p = 0.85 and 0.11 at t = 48 and 672 h, respectively. Myoblasts seeded at the high density resulted in the immediate cessation of growth with keeping the low range of R_p = 0.02–0.09 throughout the culture. The reduction of R_p led to the generation of three subpopulations of cells in proliferative, quiescent and differentiated states. Close cell contacts in the confluent state of high seeding culture induced cell quiescence to a higher extent with suppressing differentiation.     

Fabrication of aluminium foams from powder by hot extrusion and foaming

In order to produce aluminium foams for light-weight and energy absorbing structures of automobiles, a method for fabricating aluminium foam from powder mixed with a foaming agent by using a mould is proposed. The method consists of four sequential processes: powder compacting, extruding, foaming and moulding. In the experiment for fabricating aluminium foam from powder, the conditions of powder extrusion and foaming by the heated die are determined from the density of the aluminium foams made without a mould. The experimental results show that the relative density of the aluminium foam made under appropriate conditions is 0.22. In moulding of aluminium foam, a stainless steel pipe is used as a mould and the cylindrical aluminium foam is produced by filling into the pipe mould. The distribution of relative density within the aluminium foam bar is in a range of 0.2–0.3 by rapid cooling of the pipe. To examine the ratio of deformation energy to weight of the pipe including the aluminium foam, a compression test using a press is carried out. The deformation energy of the pipe can be increased with aluminium foam filled by the proposed method.     

Cloning and characterization of a β-N-acetylglucosaminidase (BmFDL) from silkworm Bombyx mori

In insects, β-N-acetylglucosaminidase (GlcNAcase) participates in critical physiological processes such as fertilization, metamorphosis, and glycoconjugate degradation. Insects produce glycoproteins carrying paucimannosidic-type N-glycans, the terminal GlcNAc residue of which is cleaved by a GlcNAc-linkage specific GlcNAcase, also known as the fused lobes (FDL) protein. To obtain information on the structure of GlcNAcases and insight into their contribution to physiological processes, we cloned Bombyx mori FDL (BmFDL) from silkworm larvae. The full-length cDNA (1.9 kb) encoded a protein of 633 amino acids with 42% amino acid sequence identity to Drosophila melanogaster FDL (DmFDL). Recombinant BmFDL cleaved only β-1,2-linked GlcNAc residues from the α-1,3 branch of biantennary N-glycan. This substrate specificity was similar to that of DmFDL. Microsomal FDL activity was inhibited by anti-BmFDL antibodies. Taken together, our results suggest that BmFDL is a N-glycan-processing GlcNAcase in B. mori.     

Annealing Effect in GaDyN on Optical and Magnetic Properties

The annealing effect on the optical and magnetic properties of the GaDyN layers was studied. The PL intensities of yellow and green bands as well as the intra-4f orbital transition of Dy³⁺ ions were found to decrease for the samples annealed at 900 and 1000 °C. It is supposed that the intra-4f orbital transition is related to the broad peak luminescence coming from defects. Increasing the annealing temperature, the magnetization becomes smaller. It is considerable that the number of electrons coming from defects was reduced by the annealing treatments and that the ferromagnetism in GaDyN is attributed as carrier induced ferromagnetism.