Annealing‐promoted unidirectional migration of organic‐modified nanoparticles embedded two‐dimensionally in polymer thin films

The spatial structures of oleic acid‐modified CeO₂ nanoparticles in polystyrene (PS) thin films spin‐coated on silicon substrates were observed by transmission electron microscopy, when the films underwent thermal annealing above the glass‐transition temperature of PS. Before annealing, the nanoparticles have segregated to the surface of the films, and formed two‐dimensional spatial structures in the PS films. Then, the nanoparticles migrated away from the film surface to the substrate/film interface during thermal annealing, maintaining the two‐dimensional spatial structures. In addition, we demonstrated that such unidirectional migration of nanoparticles across the PS film occurs regardless of the characteristics of the substrate surface, the concentration of nanoparticles, and the thickness of the films. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42760.     

SANS studies on catalyst ink of fuel cell

The structure of solid polymer electrode and catalyst ink of fuel cell has been investigated by focusing‐ (FSANS) and contrast‐variation small‐angle neutron scattering (CV‐SANS). The solid polymer electrode, consisting of carbon (C), platinum, and ionomer (polymer, P), exhibited a power‐law function with two asymptotes, i.e., from I(q) ～ q^?1 to I(q) ～ q^?4 with a crossover around q ≈ 0.005 Å^?1. The scattering functions of the catalyst ink, i.e., the polymer electrodes dispersed in water, were successfully decomposed to the corresponding partial structure factors, S_CC(q), S_PP(q), S_CP(q), exclusively representing C‐C, P‐P, and C‐P correlations. S_CC(q) was a monotonic decreasing function of q, dominating in the scattering from carbon clusters. On the other hand, S_PP(q) exhibited a scattering maximum characteristic of polyelectrolyte solutions. This suggests that ionic clusters in polyelectrolyte solutions are formed in catalyst ink. The cross term, S_CP(q), indicated that the carbon scattering is dominant and significant amount of ionomer is adsorbed on the carbon agglomerates. It is concluded that the catalyst ink consists of carbon agglomerates surrounded by ionomers and the presence of ionic‐cluster path plays a key role in the performance of the solid polymer electrodes in polymer electrolyte fuel cells. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39842.     

An Analysis of the Post-earthquake Fire Safety of Historic Buildings in Kyoto,Japan

Relative to other cities in Japan, Kyoto contains an outstanding agglomeration of historic buildings. These historic buildings are crucial for maintaining Kyoto’s irregular ranking as a historical city. However, several active faults occur near Kyoto that could cause severe seismic damage to the city. Thus, post-earthquake fire is one of the most threatening potential disasters that could destroy Kyoto’s invaluable historic buildings. Here, the post-earthquake fire safety of 2,131 historic buildings in the city of Kyoto was analyzed. This analysis was conducted by Monte Carlo simulation with a physics-based urban fire spread model that was formerly developed by the author. This scenario assumes the three following exclusive events that lead to the burn-down of historic buildings: (I) the ignition in the vicinity of the target historic building; (II) inadequate firefighting activity during the initial stage of the fire; and (III) the occurrence of widespread fire in urban areas following ignition. In general, the post-earthquake fire safety of designated and registered historic buildings was greater than that of undesignated and unregistered historic buildings. In addition, in the worst case scenario, 30% of the national treasures and important cultural properties would be damaged in the center of Kyoto city.     

Fabrication of Langmuir-Blodgett films using amphiphilic peptides

To introduce self-organization ability of transmembrane proteins into Langmuir (L) and Langmuir-Blodgett (LB) techniques, we focused on "amphiphilic peptide" (AP) which is composed of two distinct hydrophilic and hydrophobic domains. Three types of APs of different average hydropathies were used to prepare the AP/lipid mixed L and LB films. According to the circular dichroism spectra, the secondary structures of APs were not uniform but were a mixture of alpha-helix, beta-strand and random coil. The fraction of alpha-helix was higher for lower hydropathy AP. The interaction between AP and lipid in the L film and the structure of the LB film were also depended on the APs used.     

Properties of quantum gain of coding with information criterion by binary linear codes

In quantum information theory, superadditivity in the capacity of a quantum channel occurs as a special property. We present a method of calculating the mutual information analytically for binary linear codes by using square‐root measurement as the decoding process. Many examples of codes showing the existence of superadditivity in capacity have been given in the past, but the scope of the method was not clarified. In the present paper, we show that the method can be applied to any binary linear codes. We also show that the quantum channel capacity is almost fully attained in a finite codeword length by using approximation to simplex code. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 163(4): 48–57, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20646     

Motion recognition using local auto-correlation of space–time gradients

In this paper, we propose a motion recognition scheme based on a novel method of motion feature extraction. The feature extraction method utilizes auto-correlations of space–time gradients of three-dimensional motion shape in a video sequence. The method effectively exploits the local relationships of the gradients corresponding to the space–time geometric characteristics of the motion. For recognizing motions, we apply the framework of bag-of-frame-features, which, in contrast to the standard bag-of-features framework, enables the motion characteristics to be captured sufficiently and the motions to be quickly recognized. In experiments on various datasets for motion recognition, the proposed method exhibits favorable performances as compared to the other methods, and faster computational time even than real time.     

Numerical study of flow and heat-transfer characteristics of cryogenic slush fluid in a horizontal circular pipe (SLUSH-3D)

Cryogenic slush fluids, such as slush hydrogen and slush nitrogen, are two-phase, single-component fluids containing solid particles in a liquid. Since their density and refrigerant capacity are greater than those of liquid-state fluids alone, there are high expectations for use of slush fluids as functionally thermal fluids in various applications, such as fuels for spacecraft engines, clean energy fuels to improve the efficiency of transportation and storage, and as refrigerants for high-temperature superconducting equipment. In this research, a three-dimensional numerical simulation code (SLUSH-3D), including the gravity effect based on the thermal non-equilibrium, two-fluid model, was constructed to clarify the flow and heat-transfer characteristics of cryogenic slush fluids in a horizontal circular pipe. The calculated results of slush nitrogen flow performed using the numerical code were compared with the authors’ experimental results obtained using the PIV method. As a result of these comparisons, the numerical code was verified, making it possible to analyze the flow and heat-transfer characteristics of slush nitrogen with sufficient accuracy. The numerical results obtained for the flow and heat-transfer characteristics of slush nitrogen and slush hydrogen clarified the effects of the pipe inlet velocity, solid fraction, solid particle size, and heat flux on the flow pattern, solid-fraction distribution, turbulence energy, pressure drop, and heat-transfer coefficient. Furthermore, it became clear that the difference of the flow and heat-transfer characteristics between slush nitrogen and slush hydrogen were caused to a large extent by their thermo-physical properties, such as the solid–liquid density ratio, liquid viscosity, and latent heat of fusion.     

Photoluminescence and scintillation properties of Eu2O3–BaO–Nb2O5–TeO2 glass and glass ceramics

Journal of Materials Science: Materials in Electronics - 1Eu2O3–3BaO–20Nb2O5–76TeO2 glass and the corresponding glass-ceramics were synthesized with the aim to investigate the...