Daido University

About: Daido University is a education organization based out in Nagoya, Japan. It is known for research contribution in the topics: Ultimate tensile strength & Proton exchange membrane fuel cell. The organization has 209 authors who have published 423 publications receiving 3223 citations.

Neutron diffraction measurement of internal strain in the first Japanese ITER CS conductor sample

Abstract: Several conductor samples were fabricated and tested in the SULTAN facility at CRPP for ITER Central Solenoid (CS) conductor qualification. From the result of the cyclic testing on the first and second conductor samples named CSJA01 and CSJA02, continuous linear degradation of the current sharing temperature (Tcs) was found. From the result of the visual inspection, a large deflection on the lower loading side (LLS) in the high field zone (HFZ) was observed. The bending strain of the strands cannot be evaluated from only the deflection obtained visually. To evaluate the strain of strands in CSJA01 quantitatively, a neutron diffraction measurement of the CSJA01 left leg was performed using the engineering materials diffractometer ‘Takumi’ in J-PARC. From the result, the large bending strain at the LLS in the HFZ was found. Therefore, the Tcs degraded position in the conductor sample due to the cyclic testing can be determined.

Uniaxial strain dependence of the critical current of DI-BSCCO tapes

Abstract: In order to explain the effect of uniaxial strain on the critical current of DI-BSCCO-Bi2223 tapes, we employed a springboard sample holder that can smoothly and continuously apply both tensile and compressive strains to tape samples. Over a narrow tensile strain region, the critical current in the tapes decreased linearly with increasing strain and returned reversibly with decreasing strain. When compressive strain was applied, the critical current first increased and then reached a weak maximum. Thereafter, it decreased monotonically with further increases in compressive strain. At room temperature, the local strain exerted on BSCCO filaments was measured by means of a quantum beam diffraction technique. Over the whole tensile strain region up to 0.2% and the small compressive strain range, the local strain changed linearly with applied strain. When the compressive strain was applied beyond the relaxation strain, the local strain (measured by diffraction) versus the applied strain (measured using a strain gauge) deviated from linearity, which is characteristic of strain relaxation and the onset of BSCCO filament fracture. Thus, the strain at the maximum critical current corresponds to a crossover point in strain, above which the critical current decreased linearly and reversibly with increasing applied strain, and below which the critical current decreased due to the BSCCO filament fracture. In this paper, we clearly characterize the reversible range terminated by both compressive and tensile strains, in which filaments do not fracture. Our analysis of the compressive regime beyond the relaxation strain suggests that although BSCCO filament fracture is the primary factor that leads to a decrease in critical current, the critical current in those regions of filaments that are not fractured increases linearly and reversibly with decreasing applied strain at compressive strains well beyond the reversible region for the tape.

Catalytic Reactivity of Molybdenum-Trihalide Complexes Bearing PCP-Type Pincer Ligands.

Abstract: Molybdenum-iodide complexes bearing a PCP[1] ligand have been found to work as excellent catalysts toward ammonia formation under ambient reaction conditions among dinitrogen-bridged dimolybdenum complexes and other molybdenum complexes bearing PNP and PCP[2] ligands.

To What Extent Is the Entropy-Area Law Universal? Multi-Horizon and Multi-Temperature Spacetime May Break the Entropy-Area Law

Abstract: It seems to be a common understanding at present that, once event horizons are in thermal equilibrium, the entropy-area law holds inevitably. However no rigorous verification is given to such a very strong universality of the law in multi-horizon spacetimes. Then, on the basis of thermodynamically consistent and rigorous discussion, this paper suggests an evidence of breakdown of entropy-area law for horizons in Schwarzschild-de Sitter spacetime, in which the temperatures of the horizons are different. The outline is as follows: We construct carefully two thermal equilibrium systems individually for black hole event horizon (BEH) and cosmological event horizon (CEH), for which the Euclidean action method is applicable. The integration constant (subtraction term) in Euclidean action is determined with referring to Schwarzschild and de Sitter canonical ensembles. The free energies of the two thermal systems are functions of three independent state variables, and we find a similarity of our two thermal systems with the magnetized gas in laboratory, which gives us a physical understanding of the necessity of three independent state variables. Then, via the thermodynamic consistency with three independent state variables, the breakdown of entropy-area law for CEH is suggested. The validity of the law for BEH cannot be judged, but we clarify the key issue for BEH’s entropy. Finally we make comments which may suggest the breakdown of entropy-area law for BEH, and also propose two discussions; one of them is on the quantum statistics of underlying quantum gravity, and the other is on the SdS black hole evaporation from the point of view of non-equilibrium thermodynamics. Subject Index: 451, 454