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Watanabe K.,Shinshu University | Kim B.-S.,Shinshu University | Enomoto Y.,Toyama Industrial Technology Center | Kim I.-S.,Shinshu University
Macromolecular Materials and Engineering | Year: 2011

A straightforward method, which is termed novel handspinning, is reported for producing uniaxially aligned sPP nanofibers. As demonstrated by SEM analysis, the morphologies of handspun sPP nanofibers are strongly dependent upon the processing conditions such as spinning method and solvent system. Compared to the normal electrospun sPP nanofibers, the handspun sPP nanofibers show smoother morphologies. FT-IR analysis demonstrates a significant difference in polymer chain conformation between the handspun and electrospun sPP nanofibers. Moreover, interestingly, the handspun sPP single nanofibers show higher Young's modulus and tensile strength than electrospun sPP single nanofibers. A novel spinning technique, "Handspinning", is presented to produce uniaxially aligned nanofibers. SEM images of handspun sPP nanofibers show a smooth surface morphology and thinner fiber diameter than for electrospun sPP nanofibers, which dramatically depend on the pulling away distance and solvent system. The handspun sPP single nanofiber shows higher Young's modulus and tensile strength. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Futakuchi T.,Toyama Industrial Technology Center | Kakuda T.,Toyama Industrial Technology Center | Sakai Y.,Toyama Industrial Technology Center
Key Engineering Materials | Year: 2014

0.67BiFeO3-0.33BaTiO3 thick films were prepared by screen printing pastes prepared by kneading the 0.67BiFeO3-0. 33BaTiO3 powder in a three-roll mill with an organic vehicle. The thick films were fired with Pt bottom electrodes and ZrO2 substrates to investigate the influence of firing temperature. The microstructures and ferroelectric properties of the thick films were examined and compared with the bulk ceramics. A remanent polarization of 32.0 μC/cm2 and coercive field of 28 kV/cm were obtained for a thick film with the addition of 0.5 wt% MnO that was fired at 1050 °C. © (2014) Trans Tech Publications, Switzerland.

Sakai Y.,Toyama Industrial Technology Center | Adachi M.,Toyama Prefectural University
Japanese Journal of Applied Physics | Year: 2015

Pb(Zr,Ti)O3 and related materials have been lauded for their piezoelectric properties, but their toxicity has driven the search for alternative materials with the same high performance in electronic devices. Among these, BaTiO3-based materials are regarded as excellent substitutes. Using a screen printing method, in this study, we prepare BaTiO3 thick films on ZrO2 stabilized with 3 mol% Y2O3 (YSZ) or MgO ceramics with Pt bottom electrodes. BaTiO3 thick films prepared on YSZ and MgO substrates preferentially oriented along the a- and c-axes, respectively. The remanent polarization Pr of the MgO-based films was higher than that of the YSZ-based films (10.8 μC/cm2 vs 6.5μC/cm2) and comparable to that of BaTiO3 bulk ceramics. Thermal expansion measurements of BaTiO3, YSZ, and MgO ceramics suggested that compressive stress was exerted on the BaTiO3 thick films, causing them to orient along the c-axis. (Ba0.92Ca0.08)(Ti0.975Zr0.025)O3 thick films were also prepared on the YSZ and MgO substrates and showed similar preference for the c-axis on MgO. However, the remanent polarization of (Ba0.92Ca0.08)(Ti0.975Zr0.025)O3 thick films prepared on MgO was greater than that of bulk ceramics (14.9 μC/cm2 vs 11.0 μC/cm2). © 2015 The Japan Society of Applied Physics.

Sakai Y.,Toyama Industrial Technology Center | Futakuchi T.,Toyama Industrial Technology Center
Japanese Journal of Applied Physics | Year: 2012

Cross sections of textured BaTiO 3-based thick films prepared by screen printing were successfully analyzed by electron backscatter diffraction and scanning electron microscopy. The textured thick films were prepared by repeating the screen printing and firing processes three times. During the firing of the third layer, the calcined powder formed round particles that were integrated into the grain. The results of crystal direction map analysis of the cross sections of the thick films showed that the degree of h100i orientation increased as the firing time increased. This tendency agrees with the change in the value of the Lotgering factor. Many {111} double twins were observed in the textured thick films, which may have facilitated the formation of the textured BaTiO 3 thick film. © 2012 The Japan Society of Applied Physics.

Heki K.,Hokkaido University | Enomoto Y.,Toyama Industrial Technology Center
Journal of Geophysical Research: Space Physics | Year: 2013

Possible enhancement of ionospheric Total Electron Content (TEC) immediately before the 2011 Tohoku-oki earthquake (Mw9.0) has been reported by Heki (2011). Critical responses to it often come in two stages; they first doubt the enhancement itself and attribute it to an artifact. Second (when they accept the enhancement), they doubt the significance of the enhancement among natural variability of space weather origin. For example, Kamogawa and Kakinami (2013) attributed the enhancement to an artifact falsely detected by the combined effect of the highly variable TEC under active geomagnetic condition and the occurrence of a tsunamigenic ionospheric hole. Here we closely examine the time series of vertical TEC before and after the 2011 Tohoku-oki earthquake. We first demonstrate that the tsunami did not make an ionospheric hole, and next confirm the reality of the enhancement using data of two other sensors, ionosonde and magnetometers. The amplitude of the preseismic TEC enhancement is within the natural variability, and its snapshot resembles to large-scale traveling ionospheric disturbances. However, distinction could be made by examining their propagation properties. Similar TEC anomalies occurred before all the M ≥ 8.5 earthquakes in this century, suggesting their seismic origin. Key Points Tsunami does not make an ionpsheric hole TEC enhancement, changes in foEs and declination started together All earthquakes exceeding M8.5 are preceded by TEC enhancements ©2013. American Geophysical Union. All Rights Reserved.

Takei S.,Toyama Prefectural University | Takei S.,Osaka University | Mochiduki K.,Toyama Prefectural University | Kubo N.,Toyama Prefectural University | Yokoyama Y.,Toyama Industrial Technology Center
Applied Physics Letters | Year: 2012

This paper reports an approach using nanoparticle free polymer blends for light scattering films in liquid crystal displays. The ability to create the regularly structured circle of approximately 200 nm diameter in the light scattering film by blending two specified polymers with carboxylic acid groups and epoxy groups was demonstrated. The developed light scattering film based on thermosetting system indicated regularly structured nanomorphology, high light scattering rates of more than 3.9 at 300-600 nm of wavelength, and fast thermal cross-linking reaction at 150 °C and 60 s in thermosetting conditions for high productivity. © 2012 American Institute of Physics.

Enomoto Y.,Toyama Industrial Technology Center
Geophysical Journal International | Year: 2012

The mechanisms of seismo-electromagnetic phenomena remain largely unexplained. To address this issue, we introduce a fault model that takes account of a coupled interaction between earthquake nucleation and deep Earth gases. This interaction causes a negatively electrified gas flow due to an exo-electron attachment reaction, as the gases pass through fractured asperities. This transient activity may be regarded to be a pressure-impressed electric current generator. In the model, the current and frequency are formulated as functions of earthquake parameters. The estimated current is sufficient to explain the seismic electromagnetic signals observed at ground level. A physical model of how current generation is coupled with ionospheric electromagnetic disturbances is explained in terms of magnetic induction coupling for strong offshore earthquakes, which may provide a plausible explanation of observed ionospheric electron enhancement prior to some recent offshore earthquakes. The model also suggests that geomagnetic observations close to an epicentre of a strong offshore earthquake may provide an effective means of detecting clear and identifiable precursor signals. © 2012 The Author Geophysical Journal International © 2012 RAS.

Yamazaki S.,Toyama Industrial Technology Center
Journal of Organic Chemistry | Year: 2012

Homoallylic alcohols were efficiently converted to the corresponding 3,4-epoxy alcohols in excellent yields by methyltrioxorhenium (MTO)-catalyzed epoxidation with aqueous hydrogen peroxide as the terminal oxidant and 3-methylpyrazole (10 mol %) as an additive. The epoxidations of homoallylic alcohols proceeded under organic solvent-free conditions faster than those in dichloromethane. © 2012 American Chemical Society.

Kawasegi N.,Toyama Industrial Technology Center | Monta N.,University of Toyama
Journal of Nanoscience and Nanotechnology | Year: 2010

This study investigated methods of fabricating high-aspect-ratio structures on a silicon surface using a combination of tribo-nanolithography and wet chemical etching. Tribo-nanolithography forms an amorphous phase on a single-crystal silicon surface that has an etch resistance against potassium hydroxide so that a protruding structure can be fabricated by wet chemical etching. To fabricate highaspect-ratio structures, (110)-oriented silicon was used, and the effect of machining parameters on the structure shape was investigated. The results showed that a structure with vertical side walls could be fabricated by machining along the (112) direction. The etch resistance against potassium hydroxide depended on the normal load and number of repetitions, and the width and the maximum height were functions of these conditions. The aspect ratio of the structure increased with the etch time as long as the amorphous phase was maintained. A sub-micrometer-scale high-aspect-ratio structure was fabricated based on these results, demonstrating the possibility of using this simple and effective method. Copyright © 2010 American Scientific Publishers All rights reserved.

An effective method for suppression of ring opening and rearrangement of acid-sensitive epoxides during methyltrioxorhenium(MTO)-catalyzed epoxidation of alkenes with H2O2 by using 1-methylimidazole as a co-additive has been found. The combined use of 3-methylpyrazole and 1-methylimidazole as the additives has been found to be an effective procedure that affords excellent yields of acid-sensitive epoxides for MTO-catalyzed epoxidation. © 2010 The Royal Society of Chemistry.

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