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91.
Ekenechukwu C. Okafor Masaaki Tsukamoto Akihiro Hayakawa K.D. Kunkuma A. Somarathne Taku Kudo Taku Tsujimura Hideaki Kobayashi 《Proceedings of the Combustion Institute》2021,38(4):5139-5146
The influence of wall heat loss on the emission characteristics of ammonia-air swirling flames has been investigated employing Planar Laser-Induced Fluorescence imaging of OH radicals and Fourier Transform Infrared spectrometry of the exhaust gases in combustors with insulated and uninsulated walls over a range of equivalence ratios, ?, and pressures up to 0.5 MPa. Strong influence of wall heat loss on the flames led to quenching of the flame front near the combustor wall at 0.1 MPa, resulting in large unburned NH3 emissions, and inhibited the stabilization of flames in the outer recirculating zone (ORZ). A decrease in heat loss effects with an increase in pressure promoted extension of the fuel-rich stabilization limit owing to increased recirculation of H2 from NH3 decomposition in the ORZ. The influence of wall heat loss resulted in emission trends that contradict already reported trends in literature. NO emissions were found to be substantially low while unburned NH3 and N2O emissions were high at fuel-lean conditions during single-stage combustion, with values such as 55 ppmv of NO, 580 ppmv of N2O and 4457 ppmv of NH3 at ? = 0.8. In addition, the response of the flame to wall heat loss as pressure increased was more important than the effects of pressure on fuel-NO emission, thereby leading to an increase in NO emission with pressure. It was found that a reduction in wall heat loss or a sufficiently long fluid residence time in the primary combustion zone is necessary for efficient control of NH3 and N2O emissions in two-stage rich-lean ammonia combustors, the latter being more effective for N2O in addition to NO control. This study demonstrates that the influence of wall heat loss should not be ignored in emissions measurements in NH3-air combustion, and also advances the understanding of previous studies on ammonia micro gas turbines. 相似文献
92.
Ali Khumaeni Masahiko Tani Kazuyoshi Kurihara Kiichiro Kagawa Hideaki Niki 《Analytical letters》2017,50(12):1992-1999
A novel method of laser-induced plasma spectroscopy utilizing a pulsed transversely excited atmospheric CO2 laser has been developed for the high-sensitivity determination of heavy metals in soil. A coarse metal powder was used to trap the soil and to assist with plasma generation. When the CO2 laser (10.6?µm, 1.5?J, 200?ns) was irradiated on the metal and soil powder, a high-temperature and long-lifetime luminous plasma was induced. Fine particles of soil were dissociated and were excited in the plasma region. The method was used for the rapid determination of Cr, Pb, and Hg in loam. The limits of detection for Cr, Pb, and Hg were approximately 0.8, 15, and 0.7?mg/kg, respectively. 相似文献
93.
A moderately hydrophobic ionic liquid, tributyl(2-methoxyethyl)phosphonium bis(pentafluoroethanesulfonyl)amide ([TBMOEP+][C2C2N−]), shows a very stable liquid junction potential upon contact with an aqueous solution whose ionic strength is as low as 1 μmol dm−3. The stability with the maximum excursion of the potential within ±0.5 mV for 30 min is very promising for accurate determination of pH and other single ion activities potentiometrically. 相似文献
94.
Noriaki Suetake Hideaki Kawano Go Tanaka Hidenobu Hashikami Eiji Uchino 《Optical Review》2011,18(6):423-429
In this paper, a new image enlargement method applying the backprojection for lost pixel (BPLP) to the predefined codebook-based
method is proposed. BPLP is a method for image restoration. In BPLP, the eigenspace reflecting the characteristics of an input
image is generated from the remained pixels and is used to restore the missing pixels. In the proposed method, the eigenspace
is replaced by one generated from the predefined codebook (PDC). PDC represents edge-blurring properties in a small image
patch and consists of pairs of low- and high-frequency image patches on various edge patterns. By replacing the PDC-based
estimation of lost high-frequency components with BPLP, a fast image enlargement method retaining its performance can be developed.
Through some experiments, the effectiveness of the proposed method was demonstrated. Especially, it was confirmed that the
processing time of the proposed method was shortened to about 1/50 that of the PDC-based method. 相似文献
95.
96.
This paper proposes a method of structuring public policy by incorporating reciprocal expectation analysis. The proposed method is characterized by three components: identification of the problem structure perceived by stakeholders using cognitive maps, policy structuring analysis with a value–driver matrix and a reciprocal expectation matrix, and feasibility analysis of agreements among the stakeholders. The three types of relationship among stakeholders are derived from the feasibility analysis, which are “Dosho-imu”, “Isho-imu”, and “Domu”. Three tests of feasibility to reach the agreement are then proposed: “information-sharing test”, “bargaining test”, and “reframing test”. A case study is presented, applying the method to strategic transportation planning in the Kanto region of Japan. Finally, the potential functions of the proposed method in practice are discussed. 相似文献
97.
Toshinori Taishi Hideaki Ise Yu Murao Takayuki Osawa Masashi Suezawa Yuki Tokumoto Yutaka Ohno Keigo Hoshikawa Ichiro Yonenaga 《Journal of Crystal Growth》2010,312(19):2783-2787
Oxygen-containing germanium (Ge) single crystals with low density of grown-in dislocations were grown by the Czochralski (CZ) technique from a Ge melt, both with and without a covering by boron oxide (B2O3) liquid. Interstitially dissolved oxygen concentrations in the crystals were determined by the absorption peak at 855 cm−1 in the infrared absorption spectra at room temperature. It was found that oxygen concentration in a Ge crystal grown from melt partially or fully covered with B2O3 liquid was about 1016 cm−3 and was almost the same as that in a Ge crystal grown without B2O3. Oxygen concentration in a Ge crystal was enhanced to be greater than 1017 cm−3 by growing a crystal from a melt fully covered with B2O3; with the addition of germanium oxide powder, the maximum oxygen concentration achieved was 5.5×1017 cm−3. The effective segregation coefficients of oxygen in the present Ge crystal growth were roughly estimated to be between 1.0 and 1.4. 相似文献
98.
Masayuki Nogami Shohei Hotta Kazumasa Kugimiya Hideaki Matsubara 《Journal of Sol-Gel Science and Technology》2010,56(2):107-113
Silica-based aerogels with high transparency and high bending strength were prepared using methyltrimethoxysilane and non-ionic
surfactant under supercritical drying condition of CO2. Non-ionic surfactant, ethylene oxide/propylene oxide block copolymer, was appropriate to form the three dimensional-connected
thinner fibers of silica skeletons, which was extruded by soaking the wet gel in hot water at 50 °C, resulting in the formation
of porous materials having small pores with narrow size distribution. The transparency of aerogels increased with decreasing
the pore size, reaching to higher than 65 and 88% at 400 and 600 nm wavelength, respectively, for 10 mm thickness of sample.
The formation of fiber skeletons were discussed using small angle X-ray scattering experiments. 相似文献
99.
100.
Hideaki Ichiba Mio Nakamoto Takehiko Yajima Mitsuo Takayama Takeshi Fukushima 《Biomedical chromatography : BMC》2010,24(2):140-147
The C‐terminal octapeptide of cholecystokinin (CCK8) includes some easily oxidizable amino acids. The oxidation of CCK8 by reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) and hydroxyl radicals (OH?) was investigated using reversed‐phase high performance liquid chromatography (RP‐HPLC) and subsequent electrospray ionization mass spectrometry. The mechanism of oxidation of CCK8 in the H2O2 system differed from that of CCK8 in the Fenton system, in which OH? are produced. In the H2O2 system, 28Met and 31Met were oxidized to methionine sulfoxide, and no further oxidation or degradation/hydrolysis occurred. On the other hand, in the Fenton system, 28Met and 31Met residues were oxidized to methionine sulfone via the formation of methionine sulfoxide. In addition, the oxidized product was observed at the Trp residue but not at the Tyr residue, and small peptide fragments from CCK8 were observed in the Fenton system. From these results, it was concluded that 28Met and 31Met residues of CCK8 are susceptible to oxidation by ROS. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献