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Wada, Yuki; Furuichi, Noriyuki*; Kusano, Eisuke*; Tsuji, Yoshiyuki*
Proceedings of 11th International Symposium on Turbulence and Shear Flow Phenomena (TSFP-11) (Internet), 6 Pages, 2019/07
This paper reports characteristics of turbulence intensity profile obtained in high Reynolds number actual flow facility in Japan. The experiments were performed in a pipe flow with water, and the friction Reynolds number was varied up to 
= 2.0 
10
. The streamwise velocity was measured by laser Doppler velocimetry (LDV). The new procedure to correct the measurement volume effect of LDV is suggested and we discuss turbulence intensity issues such as the inner peak Reynolds number dependence and the outer logarithmic behavior, it was found that these characteristic behaviors are consistent with previous turbulence studies.
Wada, Yuki; Furuichi, Noriyuki*; Kusano, Eisuke*; Tsuji, Yoshiyuki*
Proceedings of 15th International Conference on Flow Dynamics (ICFD 2018) (USB Flash Drive), p.778 - 779, 2018/11
Spatial resolution effect of LDV (Laser Doppler Velocimetry) on the time-averaged statistics is presented in high Reynolds number turbulent pipe flow. Employing PDF (Probability Density Function) of streamwise velocity, we report the study of overestimation of time-averaged statistics based on the size of measurement volume. We proposed a simple equation to estimate their spatial resolution effect. Using the proposed equation, the measurement position and the measurement volume calculated precisely based on experimental setup, it was found that the correction for spatial resolution effect is possible. Analyzing the pipe flow data measured by LDV, we estimated the expected turbulence intensity profile. The validity of the present correction method was confirmed by comparing the correction result based on the low-resolution experimental result with the high-resolution experimental result.
Suzuki, Tomoya*; Ogata, Takeshi*; Tanaka, Mikiya*; Kobayashi, Toru; Shiwaku, Hideaki; Yaita, Tsuyoshi; Narita, Hirokazu*
Metals, 8(7), p.558_1 - 558_10, 2018/07
Times Cited Count：1 Percentile：52.95(Materials Science, Multidisciplinary)The refining of platinum group metals is based mainly on solvent extraction methods, whereas Ru is selectively recovered by distillation as RuO
. Replacement of distillation byextraction is expected to simplify the purification process. To develop an effective extraction system for Ru, we analyzed the Ru species in HCl with UV-Vis and EXAFS spectroscopies, and we examined the properties of Ru extracted with N-2-ethylhexyl-bis(N-di-2-ethylhexyl-ethylamide) amine (EHBAA). EXAFS and UV-Vis spectra of Ru in HCl solutions revealed that the predominant Ru species in 0.5-10 M HCl solutions changed from [RuCl(H
O)]
to [RuCl
]
with the HCl concentration. The extraction percentages of Ru in the EHBAA system increased with increasing HCl concentration, reached 80% at [HCl] = 5 M, and decreased athigher HCl concentrations. EXAFS analysis of the extracted complex indicated that the Ru
had 5 Cl and 1 HO in its inner coordination sphere. The similarity of the dependence on HCl concentrations of the extraction in the EHBAA system and the distribution profile of [RuCl
(HO)]
on [RuCl
(HO)
]
suggested that the EHBAA extracted the pentachlorido species.
Furuichi, Noriyuki*; Terao, Yoshiya*; Wada, Yuki; Tsuji, Yoshiyuki*
Physics of Fluids, 30(5), p.055101_1 - 055101_7, 2018/05
Percentile：100(Mechanics)
-conjugated zig-zag chain of carbon atoms with sulfur-functional groupIkeura, Hiromi*; Sekiguchi, Tetsuhiro
Applied Physics Letters, 111(23), p.231605_1 - 231605_4, 2017/12
Percentile：100(Physics, Applied)Photo-oxidative doping processes were studied for the trans-polyacetylene (PA) backbone with the -SCH
side group as a chemically representative of the S-functionalized zig-zag graphene nanoribbon edge. Sulfur K-edge X-ray absorption near edge structure (XANES) spectroscopy indicates that photochemical reaction of S-CH with atmospheric O
forms selectively oxidized products such as -S(O)CH and -SO
bound to the (PA) backbone. Using the correlation between the oxidation states of sulfur and the XANES peak positions, the partial charge distribution of CHS
-PA
has been estimated. The results can provide some strategy for area-selective and controllable doping processes of atomic-scale molecular systems with the assistance of UV light.
Narita, Hirokazu*; Maeda, Motoki*; Tokoro, Chiharu*; Suzuki, Tomoya*; Tanaka, Mikiya*; Motokawa, Ryuhei; Shiwaku, Hideaki; Yaita, Tsuyoshi
Analytical Sciences, 33(11), p.1305 - 1309, 2017/11
Times Cited Count：1 Percentile：85.18(Chemistry, Analytical)
AsIida, Kazuki*; Ishikado, Motoyuki*; Nagai, Yuki; Yoshida, Hiroyuki*; Christianson, A. D.*; Murai, Naoki; Kawashima, Kenji*; Yoshida, Yoshiyuki*; Eisaki, Hiroshi*; Iyo, Akira*
Journal of the Physical Society of Japan, 86(9), p.093703_1 - 093703_4, 2017/09
Times Cited Count：14 Percentile：1.1(Physics, Multidisciplinary)Igarashi, Masayasu*; Matsumoto, Tomohiro*; Yagihashi, Fujio*; Yamashita, Hiroshi*; Ohara, Takashi; Hanashima, Takayasu*; Nakao, Akiko*; Moyoshi, Taketo*; Sato, Kazuhiko*; Shimada, Shigeru*
Nature Communications (Internet), 8, p.140_1 - 140_8, 2017/07
Times Cited Count：2 Percentile：70.98(Multidisciplinary Sciences)Narita, Hirokazu*; Suzuki, Tomoya*; Motokawa, Ryuhei
Nippon Kinzoku Gakkai-Shi, 81(4), p.157 - 167, 2017/04
Times Cited Count：2 Percentile：60.17(Metallurgy & Metallurgical Engineering)Maeda, Motoki*; Narita, Hirokazu*; Tokoro, Chiharu*; Tanaka, Mikiya*; Motokawa, Ryuhei; Shiwaku, Hideaki; Yaita, Tsuyoshi
Separation and Purification Technology, 177, p.176 - 181, 2017/04
Miyakawa, Kazuya; Ishii, Eiichi; Hirota, Akinari*; Komatsu, Daisuke*; Ikeya, Kosuke*; Tsunogai, Urumu*
Applied Geochemistry, 76, p.218 - 231, 2017/01
Times Cited Count：7 Percentile：19.24(Geochemistry & Geophysics)no abstracts in English
Asahina, Daisuke*; Aoyagi, Kazuhei; Kim, K.*; Birkholzer, J.*; Birkholzer, J. T.*; Bolander, J. E.*
Computers and Geotechnics, 81, p.195 - 206, 2017/01
Times Cited Count：11 Percentile：5.27(Computer Science, Interdisciplinary Applications)Motokawa, Ryuhei; Kobayashi, Toru; Endo, Hitoshi*; Ikeda, Takashi; Yaita, Tsuyoshi; Suzuki, Shinichi; Narita, Hirokazu*; Akutsu, Kazuhiro*; Heller, W. T.*
Journal of Nuclear Science and Technology, 53(8), p.1205 - 1211, 2016/08
Percentile：100(Nuclear Science & Technology)Takahashi, Satoru*; Okuda, Yasutake*; Kawabata, Kuniaki; Aonuma, Hitoshi*; Sato, Yutaka*; Iwata, Kenji*
Journal of Signal Processing, 20(2), p.65 - 74, 2016/03
Sekiguchi, Tetsuhiro; Baba, Yuji; Hirao, Norie; Honda, Mitsunori; Izumi, Toshinori; Ikeura, Hiromi*
Molecular Crystals and Liquid Crystals, 622(1), p.44 - 49, 2015/12
Percentile：100(Chemistry, Multidisciplinary)The molecular orientation is one of the important factors for controlling various properties in organic semiconductor materials. Films are usually heterogeneous. Thus they exist as a mixture of microscopic domains which have a variety of orientation directions. Therefore, it is essential to observe selectively microscopic domains with different orientation direction. In this work, we have developed the photoelectron emission microscopy (PEEM) system combined with the linearly polarized vacuum ultraviolet (VUV) light or synchrotron radiation (SR) X-rays. PEEM images (FOV = ca.50 micro m) for poly(3-hexylthiophene), P3HT thin films were observed under the UV irradiation with various polarization angles, including in-plain and out-of-plain polarization. Morphologies at some bright parts are different each other. The resultant observation suggests that it enables us to distinguish oriented micro-domains with specific directions of polymer chain axis from other amorphous parts.
Ikeura, Hiromi*; Sekiguchi, Tetsuhiro
Molecular Crystals and Liquid Crystals, 622(1), p.50 - 54, 2015/12
Percentile：100(Chemistry, Multidisciplinary)Organic electrically conducting -stacked molecules are widely regarded as promising materials for future application of nanoelectronics. Direct measurements of electronic structures of unoccupied states in organic semiconductors lead to better understanding of mechanism of electron conduction. For probing unoccupied partial density of states (DOS), X-ray absorption spectroscopy (XAS) is commonly used, where selective excitation of the 1s core electron to the unoccupied conduction band is possible. However, XAS cannot distinguish localized and delocalized features without comparing any theoretical approach. In this work, the core-hole-clock method in resonant Auger spectroscopy (RAS) has been applied to probe electron delocalization through the empty conduction band in the attosecond domain for the purpose of exploring electronic materials with high-speed electron transport. We will discuss some organic molecules such as pentacenes.
Ogawa, Hiroshi*; Ikeura, Hiromi*; Sekiguchi, Tetsuhiro
Molecular Crystals and Liquid Crystals, 622(1), p.164 - 169, 2015/11
Percentile：100(Chemistry, Multidisciplinary)Unoccupied electronic states near the Fermi level of poly(dimethylsilane) were probed using Si 1s X-ray absorption spectroscopy (XAS) and Si KL
L resonant Auger spectroscopy (RAS). The measured resonance peaks of XAS spectra near Si K-edge have been assigned in comparison with the discrete variational (DV)-X
molecular orbital calculations. The rapid delocalization of Si 1s core-excited electron through the empty conduction band was observed along the polymer chain with the energy dependent RAS measurement, and the electron delocalization time was estimated based on the core-hole clock method.
Amemiya, Kuniaki*; Koshikawa, Hiroshi; Yamaki, Tetsuya; Maekawa, Yasunari; Shitomi, Hiroshi*; Numata, Takayuki*; Kinoshita, Kenichi*; Tanabe, Minoru*; Fukuda, Daiji*
Nuclear Instruments and Methods in Physics Research B, 356-357, p.154 - 159, 2015/08
Percentile：100(Instruments & Instrumentation)Broadband low reflectance materials have various applications in the field of optical energy management; however, materials with ultra-low reflectance (below 0.1%) have been considered as mechanically delicate. We have developed a novel hard-surface optical absorber with microstructured, diamond-like carbon coated ion tracks on CR-39 plastic substrate. The spectral reflectance of the first prototype was below 2% for wavelengths ranging from 400 nm to 1400 nm; moreover, the optical absorber had mechanically hard surface and exhibited temporal durability. Choosing the appropriate design of the surface structure and coating layer is likely to reduce the reflectance to the order of 0.1%. This technique yields easy-to-handle broadband ultra-low reflectance absorbers.
impactsKitayama, Takumi*; Nakajima, Kaoru*; Suzuki, Motofumi*; Narumi, Kazumasa; Saito, Yuichi; Matsuda, Makoto; Sataka, Masao*; Tsujimoto, Masahiko*; Isoda, Shoji*; Kimura, Kenji*
Nuclear Instruments and Methods in Physics Research B, 354, p.183 - 186, 2015/07
Times Cited Count：2 Percentile：66.76(Instruments & Instrumentation)
-rayKitatani, Fumito; Harada, Hideo; Goko, Shinji*; Utsunomiya, Hiroaki*; Akimune, Hidetoshi*; Toyokawa, Hiroyuki*; Yamada, Kawakatsu*
JAEA-Conf 2014-002, p.57 - 62, 2015/02
