Tetsuya Kimura, Yutaka Kishimoto, Masashi Omura, Ken‐ya Hashimoto,
In this paper, the use of a structure comprising a thin LiNbO3 plate and a multilayered acoustic mirror composed of SiO2 and Pt for high-performance longitudinal leaky surface acoustic wave (LLSAW) device is proposed. The mirror is expected to offer a much higher reflectivity than that composed of SiO2 and AlN, which the authors proposed previously. The field distribution of these structures is calculated by using a finite element method. It is shown that the acoustic wave energy of the proposed ...
Tópico(s): Ferroelectric and Piezoelectric Materials
2018 - Institute of Physics | Japanese Journal of Applied Physics
Hiroyuki Kishimoto, Masashi Momiyama, Ryoichi Aki, Hiroaki Kimura, Atsushi Suetsugu, Michael Bouvet, Toshiyoshi Fujiwara, Robert M. Hoffman,
Currently-used rodent tumor models, including transgenic tumor models, or subcutaneously growing tumors in mice, do not sufficiently represent clinical cancer. We report here development of methods to obtain a highly clinically-accurate rectal cancer model. This model was established by intrarectal transplantation of mouse rectal cancer cells, stably expressing green fluorescent protein (GFP), followed by disrupting the epithelial cell layer of the rectal mucosa by instilling an acetic acid solution. ...
Tópico(s): Cancer Cells and Metastasis
2013 - Public Library of Science | PLoS ONE
Takuzo Kishimoto, Masashi Sasa, Shuji Takaori,
Electrophysiological studies were performed to elucidate the effect of 5-hydroxytryptamine (5-HT) originating in the dorsal raphe nucleus (DR) on neuronal activity in the lateral vestibular nucleus (LVN) neurons, using cats anesthetized with α-chloralose. LVN neurons were classified into monosynaptic and polysynaptic neurons according to their responses to vestibular nerve stimulation. Conditioning stimuli applied to the DR inhibited orthodromic spikes elicited by vestibular nerve stimulation predominantly ...
Tópico(s): Olfactory and Sensory Function Studies
1991 - Elsevier BV | Brain Research
Uichiro Kishimoto, Masashi Tazawa,
The concentrations of K+, Na+ and Cl− in the cytoplasm of Lamprothamnium succinctum, a brackish water Characeae, are about 137, 47 and 86 mM respectively. The concentration of K+ in the cytoplasm is of the same order as that in the cell sap, while the concentrations of Na+ and Cl− are much lower than those in the cell sap (i.e., 140 mM Na+, 370 mM Cl−). In the brackish water, in which the plant grows, the internodes is never excitable electrically. However, it acquires excitability when it is kept ...
Tópico(s): Analytical chemistry methods development
1965 - Oxford University Press | Plant and Cell Physiology
Uichiro Kishimoto, Masashi Tazawa,
Tópico(s): Plant Pathogens and Fungal Diseases
1965 - Oxford University Press | Plant and Cell Physiology
Katsuyuki Teramoto, Hiroshi Iwai, Masashi Kishimoto, Tomohisa Kawaguchi, Masashi Takemoto, Motohiro Saito, Hideo Yoshida,
To control the temperature distribution in the Ni–YSZ (yttria-stabilized zirconia) anode of solid oxide fuel cells (SOFCs) by efficiently utilizing the heat generated by electrochemical reactions, the supply of methane–ammonia mixed fuel is proposed. The reaction characteristics of reforming/decomposition of the mixed fuel on a Ni–YSZ catalyst are experimentally investigated. A mixture gas of methane, steam, ammonia, and balance argon is supplied to a packed bed catalyst placed in a quartz tube in ...
Tópico(s): Catalytic Processes in Materials Science
2020 - Elsevier BV | International Journal of Hydrogen Energy
Yuan Bu, Mamoru Imade, Hiroki Kishimoto, Masashi Yoshimura, Takatomo Sasaki, Yasuo Kitaoka, Masashi Isemura, Yusuke Mori,
Abstract In this study, we investigated the relationship between surface morphology and oxygen concentration in GaN layers synthesized from Ga2O vapor and NH3. The surface morphology of GaN layers changed from rough (with large numbers of pits) to (0 0 0 1) smooth planes with the increase in NH3 concentration. SIMS mapping analysis revealed that the oxygen concentration was on the order of 1017 atoms/cm3, the lowest level obtained in GaN layers synthesized from Ga2O vapor and NH3, at the smooth (0 ...
Tópico(s): ZnO doping and properties
2011 - Elsevier BV | Journal of Crystal Growth
Harumi Yokokawa, Yuichi Hori, T. Shigehisa, M. Suzuki, Shuichi Inoue, Toshihide Suto, Kazuo Tomida, Megumi Shimazu, Akira Kawakami, Hirofumi Sumi, Makoto Ohmori, Nobuhiko Mori, T. Iha, Katsuhiko Yamaji, Haruo Kishimoto, Katherine Develos-Bagarinao, Kazunari Sasaki, Shunsuke Taniguchi, Tatsuya Kawada, Mayu Muramatsu, Kenjiro Terada, Koichi Eguchi, Toshiaki Matsui, Hiroshi Iwai, Masashi Kishimoto, Naoki Shikazono, Yoshihiro Mugikura, Tohru Yamamoto, Masahiro Yoshikawa, Kenji Yasumoto, K. Asano, Yoshio Matsuzaki, Shinji Amaha, Takaaki Somekawa,
Abstract Long‐term performance testes by CRIEPI (Central Research Institute for Electric Power Industry) on six industrial stacks have revealed an interesting correlation between cathode polarization loss and ohmic loss. To make clear the physicochemical meaning of this correlation, detailed analyses were made on the conductivity degradation of YSZ electrolyte in button cells and then on the ohmic losses in the industrial cells in terms of time constants which are determined from speed of the tetragonal ...
Tópico(s): Molten salt chemistry and electrochemical processes
2017 - Wiley | Fuel Cells
Harumi Yokokawa, M. Suzuki, Masakazu Yoda, Toshihide Suto, Kazuo Tomida, Kenichi Hiwatashi, Megumi Shimazu, Akira Kawakami, Hirofumi Sumi, Makoto Ohmori, Tomohiro Ryu, Nobuhiko Mori, Michiaki Iha, Shinnichi Yatsuzuka, Katsuhiko Yamaji, Haruo Kishimoto, Katherine Develos-Bagarinao, Taro Shimonosono, Kazunari Sasaki, Shunsuke Taniguchi, Tatsuya Kawada, Mayu Muramatsu, Kenjiro Terada, Koichi Eguchi, Toshiaki Matsui, Hiroshi Iwai, Masashi Kishimoto, Naoki Shikazono, Yoshihiro Mugikura, Tohru Yamamoto, Masahiro Yoshikawa, Kenji Yasumoto, K. Asano, Yoshio Matsuzaki, Koki Sato, Takaaki Somekawa,
Abstract Achievements of NEDO durability projects on SOFC mode are summarized with a focus on the physicochemical mechanisms characterized by diffusion properties of cell components and chemical reactions of cell components with gaseous impurities. Ni sintering and depletion including impurity (P, B, S) effects have been examined in terms of the surface/interface energies of Ni/oxide cermet anodes. The conductivity degradation due to the transformation of the cubic YSZ electrolyte was found to be ...
Tópico(s): Fuel Cells and Related Materials
2019 - Wiley | Fuel Cells
Haewon Seo, Masashi Kishimoto, Taishi Nakagawa, Hiroshi Iwai, Hideo Yoshida,
The mechanism whereby structural modification on the mesoscale order (10–100 μm) improves the electrochemical performance of anode-supported solid oxide fuel cells (SOFCs) is elucidated. After preparing two types of anode-supported SOFC having different electrode–electrolyte interfacial areas, we carry out their structural analyses and electrochemical characterization. Next, we develop a two-dimensional (2D) numerical model in which the structures of the cells are implemented and then verify its validity ...
Tópico(s): Catalysis and Oxidation Reactions
2021 - Elsevier BV | Journal of Power Sources
Mengzheng Ouyang, Antonio Bertei, Samuel J. Cooper, Yufei Wu, Paul Boldrin, Xinhua Liu, Masashi Kishimoto, Huizhi Wang, Max Naylor Marlow, Jingyi Chen, Xiaolong Chen, Yuhua Xia, Billy Wu, Nigel P. Brandon,
Tópico(s): Electrocatalysts for Energy Conversion
2020 - Elsevier BV | Journal of Energy Chemistry
Grzegorz Brus, Piotr F. Raczkowski, Masashi Kishimoto, Hiroshi Iwai, Janusz S. Szmyd,
A standard fuel cell requires hydrogen for operation; however, to achieve near-term applications fuel cells need to use the existing infrastructure and already available fuels such as methane. In this respect, solid oxide fuel cells are promising candidates for distributed stationary power generation. However, feeding methane directly into the anode is liable to carbon deposition at low temperatures or to cause thermal stress due to the endothermic steam-methane reforming reaction at high temperatures. ...
Tópico(s): Electrocatalysts for Energy Conversion
2020 - Elsevier BV | Energy Conversion and Management
Haewon Seo, Masashi Kishimoto, Changsheng Ding, Hiroshi Iwai, M. Saito, Hideo Yoshida,
Abstract To improve the electrochemical performance of anode‐supported solid oxide fuel cells (SOFCs), microextrusion printing and wet infiltration techniques are employed for structural modification on the meso‐ (10–100 µm) and nanoscale order, respectively. In the mesoscale structural modification, anode ridge structures are fabricated by extruding an anode slurry on the surface of a flat anode disk to extend the electrode–electrolyte interfacial area. In the nanoscale structural modification, gadolinium‐ ...
Tópico(s): Magnetic and transport properties of perovskites and related materials
2020 - Wiley | Fuel Cells
Masashi Kishimoto, Hiroki Muroyama, Shinsuke Suzuki, M. Saito, Tomoyo Koide, Yosuke Takahashi, Toshitaka Horiuchi, H Yamasaki, S. Matsumoto, Hidehito Kubo, N. Takahashi, Akihiro Okabe, Satoshi Ueguchi, Mun-Suk Jun, Akira Tateno, Takahiro Matsuo, Toshiaki Matsui, Hiroshi Iwai, Hideo Yoshida, Koichi Eguchi,
Abstract Power generation performance and long‐term durability of ammonia‐fueled solid oxide fuel cell (SOFC) systems are investigated with SOFC stacks consisting of 30 planar anode‐supported cells. SOFC systems with three different operation modes are employed: direct ammonia, external decomposition and autothermal decomposition. A novel BaO/Ni/Sm 2 O 3 /MgO catalyst is newly developed for the external ammonia cracker, whereas a Co‐Ce‐Zr composite oxide catalyst is used for the autothermal ammonia ...
Tópico(s): Electrocatalysts for Energy Conversion
2020 - Wiley | Fuel Cells
Haewon Seo, Hiroshi Iwai, Masashi Kishimoto, Changsheng Ding, Motohiro Saito, Hideo Yoshida,
Microextrusion printing is employed for increasing the interfacial area between the electrode and electrolyte of anode-supported solid oxide fuel cells (SOFCs) to enhance their electrochemical performance. A homogeneous anode paste is prepared as an extrusion material and its rheological properties are measured. Then, the printing resolution (line width of the printed paste) is evaluated by extruding the paste under various printing conditions to determine the appropriate stage speed and flow rate ...
Tópico(s): Electrocatalysts for Energy Conversion
2020 - Elsevier BV | Journal of Power Sources
Tan Wee Choon, Hiroshi Iwai, Masashi Kishimoto, Hideo Yoshida,
The effects of flow configuration in solid oxide fuel cell (SOFC) stacks are investigated using a quasi-three-dimensional numerical model. Flow configurations with alternated air flows in parallel and perpendicular to the fuel flows are considered in addition to the conventional co-, counter-, and cross-flow configurations. The stacks have eight cells with unity aspect ratio and an active area of 4900 mm2 and are compared at fuel utilization of 0.193, 0.386, 0.579, and 0.772. The numerical model ...
Tópico(s): Chemical Looping and Thermochemical Processes
2018 - Elsevier BV | Journal of Power Sources
Tan Wee Choon, Hiroshi Iwai, Masashi Kishimoto, Grzegorz Brus, Janusz S. Szmyd, Hideo Yoshida,
Planar solid oxide fuel cells (SOFCs) with decomposed ammonia are numerically studied to investigate the effect of the cell aspect ratio. The ammonia decomposer is assumed to be located next to the SOFCs, and the heat required for the endothermic decomposition reaction is supplied by the thermal radiation from the SOFCs. Cells with aspect ratios (ratios of the streamwise length to the spanwise width) between 0.130 and 7.68 are provided with the reactants at a constant mass flow rate. A parametric ...
Tópico(s): Catalysis and Oxidation Reactions
2018 - Elsevier BV | Journal of Power Sources
Masashi Kishimoto, Tatsuya Kume, Hiroshi Iwai, Hideo Yoshida,
Two-dimensional numerical model of an ammonia-fueled planar solid oxide fuel cell is developed to investigate the distributions of flow, temperature, species and electrochemical quantities within the cell. The model consists of the conservation equations of mass, momentum, energy, species and charge carriers, which are coupled by the electrochemical oxidation of hydrogen and the ammonia decomposition reaction. Comparison between the direct ammonia supply and pre-decomposed ammonia supply cases gives ...
Tópico(s): Electrocatalysts for Energy Conversion
2017 - Institute of Physics | ECS Transactions
Takeou Okanishi, Keisho Okura, Atthapon Srifa, Hiroki Muroyama, Toshiaki Matsui, Masashi Kishimoto, M. Saito, Hiroshi Iwai, Hideo Yoshida, M. Saito, Tomoyo Koide, Hiroshi Iwai, Shinsuke Suzuki, Yosuke Takahashi, Toshitaka Horiuchi, H Yamasaki, S. Matsumoto, Shuji Yumoto, Hidehito Kubo, Jun Kawahara, Akihiro Okabe, Yuki Kikkawa, Taiji Isomura, Koichi Eguchi,
Abstract Several solid oxide fuel cell (SOFC) systems can be considered for the NH 3 utilization. In this study, the catalytic activity and long‐term stability of the NH 3 decomposition reactor with the Ni/Y 2 O 3 ‐based catalysts and the autothermal NH 3 cracker with the Co–Ce–Zr composite oxide catalyst were investigated. Moreover, the NH 3 decomposition reactor and the autothermal NH 3 cracker were combined with the SOFC stack and their performances of the stack were compared to those fueled with ...
Tópico(s): Ammonia Synthesis and Nitrogen Reduction
2017 - Wiley | Fuel Cells
Masashi Kishimoto, Y Kawakami, Yuki Otani, Hiroshi Iwai, Hideo Yoshida,
Ni/yttria-stabilized zirconia anodes of solid oxide fuel cells are fabricated by a wet infiltration technique and the ability of the infiltration technique to control the anode microstructure is quantitatively demonstrated by a detailed three-dimensional microstructural analysis. The microstructural analysis reveals favorable aspects of the infiltrated anodes, such as larger triple-phase boundary density and sufficiently large pore size, and they are mostly unachievable by the conventional powder- ...
Tópico(s): Fuel Cells and Related Materials
2017 - Elsevier BV | Scripta Materialia
Moshiel Biton, Vladimir Yufit, Farid Tariq, Masashi Kishimoto, Nigel P. Brandon,
In this study we present a novel method of lithium ion battery electrode sample preparation with a new type of epoxy impregnation, brominated (Br) epoxy, which is introduced here for the first time for this purpose and found suitable for focused ion beam scanning electron microscope (FIB-SEM) tomography. The Br epoxy improves image contrast, which enables higher FIB-SEM resolution (3D imaging), which is amongst the highest ever reported for composite LFP cathodes using FIB-SEM. In turn it means that ...
Tópico(s): Electron and X-Ray Spectroscopy Techniques
2016 - Institute of Physics | Journal of The Electrochemical Society
Kota Miyoshi, Takuma Miyamae, Hiroshi Iwai, Motohiro Saito, Masashi Kishimoto, Hideo Yoshida,
In this paper, we propose an empirical formula for i0,TPB, the exchange current density per unit triple-phase boundary (TPB) length, for porous lanthanum strontium manganite (LSM) cathodes of solid oxide fuel cells (SOFCs); the evaluation of i0,TPB is of crucial importance in numerical simulations of electrodes based on reconstructed microstructures obtained by a dual beam focused ion beam scanning electron microscopy (FIB-SEM) and tomography techniques. To derive a widely applicable empirical formula ...
Tópico(s): Magnetic and transport properties of perovskites and related materials
2016 - Elsevier BV | Journal of Power Sources
Masashi Kishimoto, Naoto Furukawa, Tatsuya Kume, Hiroshi Iwai, Hideo Yoshida,
Ammonia decomposition rate on a conventional porous Ni-YSZ anode of solid oxide fuel cells (SOFCs) is experimentally investigated under various temperatures and gas compositions to formulate a reaction rate equation. It is confirmed that the decomposition rate depends not only on the partial pressure of ammonia but also on that of hydrogen at the common operating conditions of SOFCs, with larger hydrogen concentration significantly reducing the decomposition rate. 3D microstructure of the tested ...
Tópico(s): Electrocatalysts for Energy Conversion
2016 - Elsevier BV | International Journal of Hydrogen Energy
Kota Miyoshi, Hiroshi Iwai, Masashi Kishimoto, Motohiro Saito, Hideo Yoshida,
A three-dimensional numerical model of a single solid oxide fuel cell (SOFC) considering chromium poisoning on the cathode side has been developed to investigate the evolution of the SOFC performance over long-term operation. The degradation model applied in the simulation describes the loss of the cathode electrochemical activity as a decrease in the active triple-phase boundary (TPB) length. The calculations are conducted for two types of cell: lanthanum strontium manganite (LSM)/yttria-stabilized ...
Tópico(s): Magnetic and transport properties of perovskites and related materials
2016 - Elsevier BV | Journal of Power Sources
Masashi Kishimoto, Marina Lomberg, Enrique Ruiz‐Trejo, Nigel P. Brandon,
A one-dimensional numerical model of a nickel-infiltrated gadolinium-doped ceria (Ni-GDC) electrode has been developed to investigate the effects of electrode microstructure on performance. Electrode microstructural information was obtained with focused ion beam tomography and microstructural parameters were quantified, such as tortuosity factor, surface area and particle/pore sizes. These have been used to estimate the effective transport coefficients and the electrochemical reaction rate in the ...
Tópico(s): Magnetic and transport properties of perovskites and related materials
2015 - Elsevier BV | Electrochimica Acta
Khalil Rhazaoui, Qiong Cai, Masashi Kishimoto, Farid Tariq, Mahendra Rao Somalu, Claire S. Adjiman, Nigel P. Brandon,
© 2015 Elsevier Ltd. All rights reserved.The effective conductivity of thick-film solid oxide fuel cell (SOFC) electrodes plays a key role in their performance. It determines the ability of the electrode to transport charge to/from reaction sites to the current collector and electrolyte. In this paper, the validity of the recently proposed 3D resistor network model for the prediction of effective conductivity, the ResNet model, is investigated by comparison to experimental data. The 3D microstructures ...
Tópico(s): Fuel Cells and Related Materials
2015 - Elsevier BV | Electrochimica Acta
V. Duboviks, Robert C. Maher, Masashi Kishimoto, L. F. Cohen, Nigel P. Brandon, Gregory J. Offer,
In situ and ex situ Raman analyses of porous Ni/CGO electrodes reveal differences in the amount, location and type of carbon formed during CO/CO 2 electrolysis. The majority of the carbon forms in the region of the anode, which lies in the range of ca . 4 micrometers from the electrode–electrolyte interface.
Tópico(s): Electrocatalysts for Energy Conversion
2014 - Royal Society of Chemistry | Physical Chemistry Chemical Physics
Kosuke Miyawaki, Masashi Kishimoto, Hiroshi Iwai, Motohiro Saito, Hideo Yoshida,
This paper reports the evaluation of the electrochemically active region in solid oxide fuel cell (SOFC) electrodes through experimental, numerical and semi-analytical approaches. In the experiment, anodes with several different thicknesses were fabricated and their performance was measured to find its dependence on the anode thickness, microstructure and operating conditions. The three-dimensional (3D) microstructure of the anodes was imaged using focused ion beam scanning electron microscopy (FIB- ...
Tópico(s): Fuel Cells and Related Materials
2014 - Elsevier BV | Journal of Power Sources
Masashi Kishimoto, Marina Lomberg, Enrique Ruiz‐Trejo, Nigel P. Brandon,
This paper, for the first time, demonstrates the three-dimensional imaging of nano-particle infiltrated Ni–GDC (gadolinia-doped ceria) electrodes using focused ion beam tomography. Microstructural parameters of the actual electrode microstructure are quantified, such as volume fraction, TPB density and mean particle/pore sizes. These microstructural parameters reveal that the infiltrated electrodes have eight times larger TPB density than conventional electrodes fabricated by powder mixing and sintering ...
Tópico(s): Semiconductor materials and devices
2014 - Elsevier BV | Journal of Power Sources
Farid Tariq, Masashi Kishimoto, Vladimir Yufit, Guangshun Cui, Mahendra Rao Somalu, Nigel P. Brandon,
Solid oxide fuel cells (SOFCs) are functional electrochemical conversion devices whose performance is strongly dependent on electrode microstructure. Both the performance and lifetime of these electrochemical devices can be considerably enhanced by the ability to design better electrodes. Data acquired from high resolution 3D imaging techniques were used in the quantification of two electrode structures of different compositions. The quantified nickel-based anode data through the analysis of particle ...
Tópico(s): Semiconductor materials and devices
2014 - Elsevier BV | Journal of the European Ceramic Society