The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
N Shimoozaki - One of the best experts on this subject based on the ideXlab platform.
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withdrawn profiles of hydrogen Molar Fraction and temperature in zrv1 9fe0 1 alloy bed for hydrogen absorption
Journal of Alloys and Compounds, 2004Co-Authors: Satoshi Fukada, S Morimitsu, N Shimoozaki, Masabumi NishikawaAbstract:Profiles of hydrogen Molar Fraction and temperature in a long ZrV 1.9 Fe 0.1 alloy particle bed with a small diameter were determined experimentally and analytically as a basic study of chemical heat pumps operated at higher temperature. Since the alloy bed absorbed hydrogen even at 873 K and generated heat, the alloy was considered a suitable material for heat pump or hydrogen storage at higher temperature. Experimental profiles of both hydrogen Molar Fraction at the bed outlet and temperature inside the bed agreed with analytical solutions to heat and mass-transfer equations. The analytical solutions were obtained under the conditions where constant-pattern approximation could be applied to the temperature and concentration profiles propagating in a bed with the same velocity. Properties relating with heat transfer such as a heat capacity, enthalpy change of hydrogen absorption and a heat-transfer coefficient between a wall and particles were correlated to two dimensionless parameters, α and β.
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profiles of hydrogen Molar Fraction and temperature in zrv1 9fe0 1 alloy bed for hydrogen absorption
International Journal of Hydrogen Energy, 2004Co-Authors: Satoshi Fukada, S Morimitsu, N ShimoozakiAbstract:Abstract Profiles of hydrogen Molar Fraction and temperature in a long ZrV1.9Fe0.1 alloy particle bed with a small diameter were determined experimentally and analytically as a basic study of chemical heat pumps operated at higher temperature. Since the alloy bed absorbed hydrogen even at 873 K and generated heat, the alloy was considered a suitable material for heat pump or hydrogen storage at higher temperature. Experimental profiles of both hydrogen Molar Fraction at the bed outlet and temperature inside the bed agreed with analytical solutions to heat and mass transfer equations. The analytical solutions were obtained under the conditions where constant-pattern approximation could be applied to the temperature and concentration profiles propagating in a bed with the same velocity. Properties relating with heat transfer such as a heat capacity, enthalpy change of hydrogen absorption and a heat-transfer coefficient between a wall and particles were correlated to two dimensionless parameters, α and β.
Satoshi Fukada - One of the best experts on this subject based on the ideXlab platform.
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withdrawn profiles of hydrogen Molar Fraction and temperature in zrv1 9fe0 1 alloy bed for hydrogen absorption
Journal of Alloys and Compounds, 2004Co-Authors: Satoshi Fukada, S Morimitsu, N Shimoozaki, Masabumi NishikawaAbstract:Profiles of hydrogen Molar Fraction and temperature in a long ZrV 1.9 Fe 0.1 alloy particle bed with a small diameter were determined experimentally and analytically as a basic study of chemical heat pumps operated at higher temperature. Since the alloy bed absorbed hydrogen even at 873 K and generated heat, the alloy was considered a suitable material for heat pump or hydrogen storage at higher temperature. Experimental profiles of both hydrogen Molar Fraction at the bed outlet and temperature inside the bed agreed with analytical solutions to heat and mass-transfer equations. The analytical solutions were obtained under the conditions where constant-pattern approximation could be applied to the temperature and concentration profiles propagating in a bed with the same velocity. Properties relating with heat transfer such as a heat capacity, enthalpy change of hydrogen absorption and a heat-transfer coefficient between a wall and particles were correlated to two dimensionless parameters, α and β.
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profiles of hydrogen Molar Fraction and temperature in zrv1 9fe0 1 alloy bed for hydrogen absorption
International Journal of Hydrogen Energy, 2004Co-Authors: Satoshi Fukada, S Morimitsu, N ShimoozakiAbstract:Abstract Profiles of hydrogen Molar Fraction and temperature in a long ZrV1.9Fe0.1 alloy particle bed with a small diameter were determined experimentally and analytically as a basic study of chemical heat pumps operated at higher temperature. Since the alloy bed absorbed hydrogen even at 873 K and generated heat, the alloy was considered a suitable material for heat pump or hydrogen storage at higher temperature. Experimental profiles of both hydrogen Molar Fraction at the bed outlet and temperature inside the bed agreed with analytical solutions to heat and mass transfer equations. The analytical solutions were obtained under the conditions where constant-pattern approximation could be applied to the temperature and concentration profiles propagating in a bed with the same velocity. Properties relating with heat transfer such as a heat capacity, enthalpy change of hydrogen absorption and a heat-transfer coefficient between a wall and particles were correlated to two dimensionless parameters, α and β.
Isamu Akasaki - One of the best experts on this subject based on the ideXlab platform.
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Current injection and light confinement for UVB light emitting devices with graded p-AlGaN
2019 Compound Semiconductor Week (CSW), 2019Co-Authors: Kosuke Sato, Motoaki Iwaya, Tetsuya Takeuchi, Satoshi Kamiyama, Shinji Yasue, Yuya Ogino, Isamu AkasakiAbstract:An optimized graded p-AlGaN in which average AlN Molar Fraction is 0.55 was used for p-type layer in ultraviolet (UV)-B light emitting device. The maximum current density at 20 kA/cm2 was achieved by optimizing graded p-AlGaN structure especially in the region at high AlN Molar Fraction. A single peak emission at 295 nm from MQW was obtained from the backside of sapphire substrate.
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reduction of contact resistance in v based electrode for high aln Molar Fraction n type algan by using thin sinx intermediate layer
Physica Status Solidi (c), 2016Co-Authors: Noriaki Nagata, Motoaki Iwaya, Tetsuya Takeuchi, Satoshi Kamiyama, Takashi Senga, Isamu AkasakiAbstract:We found out the reduction of contact resistance in V-based electrode for high AlN Molar Fraction n-type AlGaN by using thin SiNx intermediate layer. The contact resistivity for n -type Al0.70Ga0.30N with the V/Al/Ni/Au electrode using SiNx intermediated layer reached 1.13 × 10-6 Ω cm2. Moreover, contact resistivity using SiNx intermediated layer had been reduced more than one order of magnitude in all AlN Molar Fractions from 0.62 to 0.87. Using this electrode, we also demonstrated UV light-emitting diodes (LEDs) on n -type Al0.70Ga0.30N underlying layer with an emission wavelength of approximately 283 nm. An operating LED voltage using a V/Al/Ni/Au electrode with SiNx intermediated layer was 3.3 V lower at 100 mA current injection than that without SiNx intermediated layer. (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
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Reduction of contact resistance in V‐based electrode for high AlN Molar Fraction n‐type AlGaN by using thin SiNx intermediate layer
Physica Status Solidi (c), 2016Co-Authors: Noriaki Nagata, Motoaki Iwaya, Tetsuya Takeuchi, Satoshi Kamiyama, Takashi Senga, Isamu AkasakiAbstract:We found out the reduction of contact resistance in V-based electrode for high AlN Molar Fraction n-type AlGaN by using thin SiNx intermediate layer. The contact resistivity for n -type Al0.70Ga0.30N with the V/Al/Ni/Au electrode using SiNx intermediated layer reached 1.13 × 10-6 Ω cm2. Moreover, contact resistivity using SiNx intermediated layer had been reduced more than one order of magnitude in all AlN Molar Fractions from 0.62 to 0.87. Using this electrode, we also demonstrated UV light-emitting diodes (LEDs) on n -type Al0.70Ga0.30N underlying layer with an emission wavelength of approximately 283 nm. An operating LED voltage using a V/Al/Ni/Au electrode with SiNx intermediated layer was 3.3 V lower at 100 mA current injection than that without SiNx intermediated layer. (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
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low ohmic contact resistance v based electrode for n type algan with high aln Molar Fraction
Japanese Journal of Applied Physics, 2016Co-Authors: Kazuki Mori, K Takeda, Toshiki Kusafuka, Motoaki Iwaya, Tetsuya Takeuchi, Satoshi Kamiyama, Isamu Akasaki, Hiroshi AmanoAbstract:We investigated a V-based electrode for the realization of low ohmic-contact resistivity in n-type AlGaN with a high AlN Molar Fraction characterized by the circular transmission line model. The contact resistivity of n-type Al0.62Ga0.38N prepared using the V/Al/Ni/Au electrode reached 1.13 × 10−6 Ω cm2. Using this electrode, we also demonstrated the fabrication of UV light-emitting diodes (LEDs) with an emission wavelength of approximately 300 nm. An operating voltage of LED prepared using a V/Al/Ni/Au electrode was 1.6 V lower at 100 mA current injection than that prepared using a Ti/Al/Ti/Au electrode, with a specific contact resistance of approximately 2.36 × 10−4 Ω cm2 for n-type Al0.62Ga0.38N.
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GaNSb alloys grown with H2and N2carrier gases
Japanese Journal of Applied Physics, 2016Co-Authors: Daisuke Komori, Motoaki Iwaya, Tetsuya Takeuchi, Satoshi Kamiyama, Kaku Takarabe, Takao Miyajima, Isamu AkasakiAbstract:We grew GaNSb layers with H2 and N2 carrier gases by metalorganic vapor phase epitaxy. We estimated the GaSb Molar Fraction in a GaNSb layer grown with H2 by Rutherford backscattering spectroscopy. A 0.8% GaSb Molar Fraction was obtained, which was consistent with the value obtained by secondary ion mass spectroscopy. We correlated the obtained GaSb Molar Fraction with the c-axis lattice constant of GaSb estimated from an X-ray difFraction pattern. We investigated GaSb Molar Fractions in GaNSb grown with H2 and N2 at various growth temperatures. While GaSb Molar Fractions in the H2 case showed a plateau at 0.8% at less than 800 °C, those in the N2 case increased to 1.1% with a decrease in the growth temperature to 750 °C. Sb incorporation into GaNSb could be further improved by carrying out growth under N2, similar to the case of GaInN growth.
Fatima Lafrad - One of the best experts on this subject based on the ideXlab platform.
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what is the state of aggregation of ethanol molecules in ethanol supercritical carbon dioxide mixtures an ftir investigation in the full Molar Fraction range
Journal of Supercritical Fluids, 2014Co-Authors: Fatima Lafrad, A Idrissi, Thierry TassaingAbstract:Abstract The evolution of the degree of hydrogen bonding of ethanol molecules in scCO2–ethanol mixtures for different Molar Fraction (from 0.5 to 100% in ethanol) in the temperature range 40–200 °C and at two different constant pressures P = 15 and 20 MPa is reported in this paper. For a given pressure, we observe a strong dependence of the degree of hydrogen bonding as a function of temperature and ethanol Molar Fraction. We emphasize that a detailed knowledge of the degree of hydrogen bonding of ethanol molecules in these binary systems is important for the understanding and the further development of the supercritical fluid technology.
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What is the state of aggregation of ethanol molecules in ethanol–supercritical carbon dioxide mixtures? An FTIR investigation in the full Molar Fraction range
Journal of Supercritical Fluids, 2014Co-Authors: Fatima Lafrad, A Idrissi, Thierry TassaingAbstract:Abstract The evolution of the degree of hydrogen bonding of ethanol molecules in scCO2–ethanol mixtures for different Molar Fraction (from 0.5 to 100% in ethanol) in the temperature range 40–200 °C and at two different constant pressures P = 15 and 20 MPa is reported in this paper. For a given pressure, we observe a strong dependence of the degree of hydrogen bonding as a function of temperature and ethanol Molar Fraction. We emphasize that a detailed knowledge of the degree of hydrogen bonding of ethanol molecules in these binary systems is important for the understanding and the further development of the supercritical fluid technology.
Masabumi Nishikawa - One of the best experts on this subject based on the ideXlab platform.
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withdrawn profiles of hydrogen Molar Fraction and temperature in zrv1 9fe0 1 alloy bed for hydrogen absorption
Journal of Alloys and Compounds, 2004Co-Authors: Satoshi Fukada, S Morimitsu, N Shimoozaki, Masabumi NishikawaAbstract:Profiles of hydrogen Molar Fraction and temperature in a long ZrV 1.9 Fe 0.1 alloy particle bed with a small diameter were determined experimentally and analytically as a basic study of chemical heat pumps operated at higher temperature. Since the alloy bed absorbed hydrogen even at 873 K and generated heat, the alloy was considered a suitable material for heat pump or hydrogen storage at higher temperature. Experimental profiles of both hydrogen Molar Fraction at the bed outlet and temperature inside the bed agreed with analytical solutions to heat and mass-transfer equations. The analytical solutions were obtained under the conditions where constant-pattern approximation could be applied to the temperature and concentration profiles propagating in a bed with the same velocity. Properties relating with heat transfer such as a heat capacity, enthalpy change of hydrogen absorption and a heat-transfer coefficient between a wall and particles were correlated to two dimensionless parameters, α and β.
