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Ye R.,Iwate University | Baba M.,Iwate University | Ohta K.,Iwate University | Suzuki K.,Iwate Industrial Research Institute
Solid-State Electronics | Year: 2010

We report the effects of thermal annealing on structure, morphology and electrical properties of fluorinated copper phthalocyanine (F 16CuPc)/α-sexithiophene (α6T) heterojunction thin films. The morphology and structure of the thin films were examined by atomic force microscopy and X-ray diffraction techniques. The thermal annealing significantly improved α6T molecular ordering although F16CuPc molecular was slightly disordered in the thermal annealing process. The smallest full width of half maximum of the 200 diffraction lines was gained at the thermal annealing temperature of 150 °C. Similarly, ambipolar performance of the F 16CuPc/α6T heterojunction transistor could be improved by the thermal annealing. At the thermal annealed temperature of 150 °C, the ambipolar device achieved high-performance with field-effect hole and electron mobilities of 8.84 × 10-3 cm2 V-1 s -1 and 1.00 × 10-2 cm2 V-1 s-1, respectively. © 2010 Elsevier Ltd. All rights reserved.

Sato E.,Iwate Medical University | Sugimura S.,Tokyo Denpa Co. | Endo H.,Iwate Industrial Research Institute | Oda Y.,Iwate Medical University | And 10 more authors.
Applied Radiation and Isotopes | Year: 2012

15. Mcps photon-counting X-ray computed tomography (CT) system is a first-generation type and consists of an X-ray generator, a turntable, a translation stage, a two-stage controller, a detector consisting of a 2. mm-thick zinc-oxide (ZnO) single-crystal scintillator and an MPPC (multipixel photon counter) module, a counter card (CC), and a personal computer (PC). High-speed photon counting was carried out using the detector in the X-ray CT system. The maximum count rate was 15. Mcps (mega counts per second) at a tube voltage of 100. kV and a tube current of 1.95. mA. Tomography is accomplished by repeated translations and rotations of an object, and projection curves of the object are obtained by the translation. The pulses of the event signal from the module are counted by the CC in conjunction with the PC. The minimum exposure time for obtaining a tomogram was 15. min, and photon-counting CT was accomplished using gadolinium-based contrast media. © 2011 Elsevier Ltd.

Meng Q.,Iwate University | Hatakeyama M.,Iwate Industrial Research Institute | Sugawara E.,Iwate University
Bioscience, Biotechnology and Biochemistry | Year: 2014

Two aroma compounds of volatile thiols, 2-furanmethanethiol (2FM) and ethyl 2-mercaptopropionate (ET2MP), were formed in five types of Japanese soy sauce during fermentation by yeast. The concentrations of 2FM and ET2MP in the soy sauce samples increased during alcoholic fermentation. The concentrations of 2FM and ET2MP were higher in the soy sauce fermented by Zygosaccharomyces rouxii than in that fermented by Candida versatilis. The enantiomers of ET2MP were separated by gas chromatography in a capillary column. The average enantiomeric ratio of ET2MP in the soy sauce was approximately 1:1. 2FM was formed by yeast in a medium prepared from cysteine and furfural, and cysteine is considered the key precursor of 2FM by yeast in soy sauce. © 2014 Japan Society for Bioscience, Biotechnology, and Agrochemistry.

Belmoubarik M.,Tohoku University | Nozaki T.,Tohoku University | Endo H.,Iwate Industrial Research Institute | Sahashi M.,Tohoku University
Journal of Applied Physics | Year: 2013

Deposition of ZnO thin films on a ferromagnetic metallic buffer layer (Co3Pt) by molecular beam epitaxy technique was investigated for realization of ZnO-based magnetic tunneling junctions with good quality hexagonal ZnO films as tunnel barriers. For substrate temperature of 600 °C, ZnO films exhibited low oxygen defects and high electrical resistivity of 130 Ω cm. This value exceeded that of hexagonal ZnO films grown by sputtering technique, which are used as tunnel barriers in ZnO-MTJs. Also, the effect of oxygen flow during deposition on epitaxial growth conditions and Co 3Pt surface oxidation was discussed. © 2013 American Institute of Physics.

Sun S.-H.,Tohoku University | Koizumi Y.,Tohoku University | Kurosu S.,Iwate Industrial Research Institute | Li Y.-P.,Tohoku University | Chiba A.,Tohoku University
Acta Materialia | Year: 2015

Co-28Cr-6Mo-0.23C-0.17N alloy cylindrical rods were fabricated by electron beam melting (EBM) with cylindrical axes along the build direction. The inhomogeneity in microstructures of the as-fabricated rods and heat-treated rods were investigated, along with the creep behavior of the heat-treated rods, focusing on the influence of microstructural inhomogeneity. Although the constituent phase varied along the build direction in the as-EBM-built rod, from single ε-hexagonal close-packed (hcp) phase in the bottom to single γ-face-centered cubic (fcc) phase in the top, the γ-fcc phase can be kept in a wide range of build height, i.e. ∼40 mm from the top finishing plane. The as-EBM-built rods consisting of both ε phase and γ phase can be transformed into single ε-hcp phase by the aging treatment at 800 °C for 24 h. However, the ε-hcp grain size in the aged rod was heterogeneous along the build height. The grain size increased along the build height at first, then decreased gradually to the position where the phase transitioned from γ-fcc to ε-hcp in the as-EBM-built rod. The grain size was nearly uniform on the top part, which used to be single γ-fcc phase. The values of stress exponent n and apparent activation energy Q were determined to be 5.0 and 365 kJ mol-1, respectively. Intergranular fracture occurred, and fracture nearly always occurred in the homogeneous fine-grain region. The decrease in stacking fault energy with increasing temperature keeps the dislocations expanding and increases the apparent activation energy. © 2014 Acta Materialia Inc.

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