Online ISSN : 2186-2451
Print ISSN : 1344-3542
Volume 85 , Issue 6
Showing 1-19 articles out of 19 articles from the selected issue
  • Sumihiro KOYAMA, Shinro NISHI, Yuriko NAGANO, Akihiro TAME, Katsuyuki ...
    2017 Volume 85 Issue 6 Pages 297-309
    Published: June 05, 2017
    Released: June 05, 2017
    The purpose of this study was to develop a novel electrical retrieval method for living spores of streptomycetes. Five strains of deep-sea Streptomyces sp. and typical strain Streptomyces albus suspended in 1/20 artificial seawater (1/20ASW) were selectively attached to an indium tin oxide/glass (ITO) working electrode region to which a −0.2 V vs. Ag/AgCl constant potential was applied for 24 h. Spores of all six streptomycetes produced either short fibrous or membranous materials and attached to the ITO electrode region. A ±20 mV vs. Ag/AgCl, 12 MHz sine-wave potential was further applied for another 1 h to the deep-sea Streptomyces sp. ST.28 spores on the ITO electrode and colony-forming units increased 3.5 fold after 3 day cultivation compared with controls. The ST.28 spores almost completely lost the ability to adhere to the potential-applied ITO electrode when dispersed in Mg2+ free 1/20ASW. We succeeded in the attachment and cultivation of specifically positioned single ST.28 spores on an ITO microelectrode surface with −0.2 V vs. Ag/AgCl potential application. A combination of micropatterning techniques for a living single streptomycete spore on the ITO electrode and omics technologies holds potential for new bioactive compound screening concepts and applications.
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  • Akito SASAKI, Atsuya SASAKI, Yoshinori KATAOKA, Syuichi SAITO, Kumpei ...
    2017 Volume 85 Issue 6 Pages 310-314
    Published: June 05, 2017
    Released: June 05, 2017
    We have previously reported that the oxygen vacancies of tungsten oxide (WO3) play an important role in determining the charge/discharge rate of lithium ion secondary batteries (LIBs). We have fabricated electrodes by spray-coating WO3 particles onto a Ti foil, then generating oxygen vacancies and inducing necking between the particles by annealing in N2. However, this conventional method is unsuitable for use in mass production because the adhesive strength between the particles and the foil is decreased by the stress generated during heat treatment and because of the high cost of the Ti foils. In this study, with the goal of enabling the mass production of electrodes, we propose a method of synthesizing WO3 particles, in which oxygen vacancies are generated before coating to form electrodes on Al foil. A synthesized mixed layer containing WO3 particles and a conductive auxiliary agent was coated on a carbon-coated Al foil to obtain a negative electrode for LIBs. As a result, an internal resistance of 3.7 Ω·cm2 was obtained. Furthermore, evaluation of the discharge rate revealed that the capacity retention rate was 65.7% at 100 C (100% at 1 C). We succeeded in fabricating the above electrodes with high-speed charge/discharge characteristics.
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  • Tomiyuki ARAKAWA, Nobuaki WATANABE, Kenta CHOKKI, Kazuhiro YABE, Ichir ...
    2017 Volume 85 Issue 6 Pages 315-318
    Published: June 05, 2017
    Released: June 05, 2017
    Zn-Al2O3 composites were electrodeposited from a non-suspended solution containing ZnSO4·7H2O and Al2(SO4)3·14–18H2O using benzyldimethyltetradecylammonium chloride dehydrate (BDTAC) as the additive at an electrodeposition current of 50–500 A/m2 with an air or a nitrogen bubbling. Initial layers with a thickness of approximately 1 µm were observed in the Zn-Al2O3 composite on copper substrates. Furthermore, the Zn-Al2O3 composite was composed of two different crystallographic areas, namely, nano-level size deposited grains with 20–60 nm in width and 100–200 nm in length, and closely packed fine particle deposits with a diameter of approximately 5 nm containing more than 26 atomic% aluminum. The nano-level size deposited grains and the closely packed fine particle deposits comprised nano-size ZnO and θ-Al2O3, respectively. The oxygen concentration in Zn-Al2O3 composite by the air bubbling was higher than that in Zn-Al2O3 composite by the nitrogen bubbling. In contrast, the zinc content ratio in Zn-Al2O3 composite by the air bubbling was lower than that in Zn-Al2O3 composite by the nitrogen bubbling. The aluminum concentration in closely packed fine particle deposits in Zn-Al2O3 composite by the air bubbling was almost the same value as that in Zn-Al2O3 composite by the nitrogen bubbling.
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Technological Report
  • Ryo MATSUOKA, Shigeo AOYAGI, Naoshi MATSUMOTO, Masaaki MATSUDAIRA, Yas ...
    2017 Volume 85 Issue 6 Pages 319-326
    Published: June 05, 2017
    Released: June 05, 2017
    We developed three modes of high resolution scanning probe microscope system based on electrochemical principles, scanning ion conductance microscopy (SICM), scanning electrochemical microscopy-scanning ion conductance microscopy (SECM-SICM), and scanning electrochemical cell microscopy (SECCM). Firstly, a developed SICM system was constructed with a nanopipette filled with electrolyte solution as a probe. High resolution topographic images of NanoCulture®Plate with hexagonal chambers with 2 µm-width banks, electrodeposited PEDOT (poly(3,4-ethylenedioxythiophane)) film, and fixed human squamous cell carcinoma were captured by the SICM. Second, SECM-SICM was performed with a double-barrel carbon nanoprobe. The one barrel of the nanoprobe was filled with carbon and used for SECM apparatus, the other barrel was filled with electrolyte for SICM configurations. Using the SECM-SICM system, simultaneous topographic and electrochemical images of micro-band electrodes with 10 µm-width line and space, and a cathode site of corrosion in the aluminum die gusto with submicron spatial resolution were obtained. Thirdly, the SECCM featuring a nanopipette probe filled with LiCl electrolyte was applied for obtaining topographies and images of current activity of a LiFePO4 electrode.
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