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330 results on '"Uto, T."'

1. Nonlinear spectroscopy of semiconductor moir\'e materials

Author

Evrard, B., Adlong, H. S., Ghita, A. A., Uto, T., Ciorciaro, L., Watanabe, K., Taniguchi, T., Kroner, M., and İmamoğlu, A.

Subjects
Condensed Matter - Strongly Correlated Electrons, Physics - Optics, Quantum Physics
Abstract

We use time-resolved nonlinear pump--probe measurements to reveal features of semiconductor moir\'e materials not accessible to linear spectroscopy. With an intense, red-detuned pump pulse, we generate a high density of virtual excitons or exciton--polarons in various moir\'e minibands. A broadband probe pulse in turn measures the response of all optical resonances induced by the pump-generated excitations. We generically observe a coherent blue shift originating from contact-like exciton--exciton interactions. At charge neutrality, these measurements allow us to assess the spatial overlap between different optical excitations and to observe signatures of a bound biexciton state between two different moir\'e exciton modes. In contrast to electron doped monolayers, spatially confined moir\'e attractive polarons behave as an ensemble of non-interacting two-level emitters, exhibiting an electron-density-independent ac-Stark effect. Tuning the pump laser into resonance with the attractive polaron, we demonstrate the filling of the moir\'e lattice with localized polarons and thereby realize a nonequilibrium Bose--Fermi mixture in moir\'e flat bands.

Published
2024

2. Screening and Coupling Currents Induced Fields on a Large-Scale Prototype REBCO Insulated Coil

Author

Zampa, A., Takahashi, K., Tsuchiya, Y., Okada, T., Awaji, S., Uto, T., Takewa, H., Hanai, S., Ioka, S., and Inagaki, J.

Abstract

The existence of screening currents is one large drawback coming from the use of REBa2Cu3O7-x with RE standing for Rare Earth (REBCO) tapes to develop superconducting coils. It not only alters the quality of the magnetic field but also implies losses and additional mechanical stresses on the tapes. The High Field Laboratory for Superconducting Materials (HFLSM) from Tohoku University, Japan, together with Toshiba are now developing a 33 T all-superconducting magnet, cooled by conduction, with a 19T Robust REBCO Insert. One important element of the design is a turn made of two-tape bundle and a turn-to-turn insulation. In addition to the screening currents, magnetic field variations will induce coupling currents developing between these two REBCO tapes in direct contact. These coupling currents also affect the magnetic field quality. Recently, a large-scale prototype of this insert was manufactured to validate the mechanical design and the protection system in the event of local dissipation coming from defects in the tapes. This article presents detailed behaviors of the screening currents and coupling currents induced fields obtained over this prototype focusing on the impact of some operating conditions such as the current ramping rate, applied-field history, and temperature of operation. The magnetic field error, i.e., the difference between the measured magnetic field and the one obtained with a homogeneous current distribution, is the main tool used to carry out this study. It reached about 0.5 T and was significantly changed by the temperature of operation and the existence of previous magnetizations, as predicted by simulations results carried out by several groups.

Published
2024
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15. Morphological changes in small pulmonary vessels are associated with severe acute exacerbation in chronic obstructive pulmonary disease

Author

Yoshimura K, Suzuki Y, Uto T, Sato J, Imokawa S, and Suda T

Subjects
chronic obstructive pulmonary disease (COPD), acute exacerbation, pulmonary vessels, cross sectional area (CSA), computed tomography, Diseases of the respiratory system, RC705-779
Abstract

Katsuhiro Yoshimura,1,2 Yuzo Suzuki,1,2 Tomohiro Uto,2 Jun Sato,2 Shiro Imokawa,2 Takafumi Suda1 1Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan; 2Department of Respiratory Medicine, Iwata City Hospital, Iwata, Japan Background: Pulmonary vascular remodeling is essential for understanding the pathogenesis of chronic obstructive pulmonary disease (COPD). The total cross-sectional area (CSA) of small pulmonary vessels has been reported to correlate with the pulmonary artery pressure, and this technique has enabled the assessment of pulmonary vascular involvements. We investigated the contribution of morphological alterations in the pulmonary vessels to severe acute exacerbation of COPD (AE-COPD).Methods: This study enrolled 81 patients with COPD and 28 non-COPD subjects as control and assessed the percentage of CSA (%CSA) less than 5 mm2 (%CSA

Published
2016

20. A highly miniturized single-chip MOEMS scanner for all-in-one imaging solution

Author

Jovic, A. (author), Uto, T. (author), Hei, K. (author), Sancho, Juan (author), Sanchez, Nuria (author), Zinoviev, Kirill (author), Rubio, Jose L. (author), Margallo, Eduardo (author), Pandraud, G. (author), Sarro, Pasqualina M (author), Jovic, A. (author), Uto, T. (author), Hei, K. (author), Sancho, Juan (author), Sanchez, Nuria (author), Zinoviev, Kirill (author), Rubio, Jose L. (author), Margallo, Eduardo (author), Pandraud, G. (author), and Sarro, Pasqualina M (author)

Abstract

A highly miniaturized, single-chip, large scanning range MOEMS scanner is demonstrated. This intrinsically-aligned, monolithically integrated device uses small angular displacement to provide a linear scanning range of 2000 μm in the lateral and 1000 μm in the vertical direction, at a working distance of 2 cm, with an average operating power lower than 170 mW. Within a footprint of only 7×10 mm2, the presented system fully integrates a photonic interferometer comprising a mirror, a silicon microlens and the MEMS actuator into a single chip, thus offering an unprecedentedly miniaturized scanning solution. The monolithic integration of all photonic components provides intrinsic alignment and excludes coupling losses often encountered in systems composed of discrete parts. No additional attenuation of the optical signal is observed during device operation. This small and high-performance device is suitable as complete system-on-chip for commercial, portable imaging applications., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., EKL Processing, ImPhys/Optics, Electronic Components, Technology and Materials

Published
2018
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21. Record-Breaking Efficiency Back-Contact Heterojunction Crystalline Si Solar Cell and Module

Author

Yamamoto, K., Adachi, D., Yoshikawa, K., Yoshida, W., Irie, T., Konishi, K., Fujimoto, T., Kawasaki, H., Kanematsu, M., Ishibashi, H., Uto, T., Takahashi, Y., Terashita, T., Koizumi, G., Nakanishi, N., and Yoshimi, M.

Subjects
Heterojunction Solar Cells, Silicon Photovoltaics
Abstract

33rd European Photovoltaic Solar Energy Conference and Exhibition; 201-204, Record-breaking efficiencies of crystalline Si (c- Si) solar cell (26.33%) and module (24.37%) using a backcontact heterojunction (BCHJ) technology are reported. Utilizing our surface passivation technology of c-Si by amorphous Si and metallization technology, we have achieved the record-breaking conversion efficiencies in the c-Si solar cell and module. Energy loss analysis of the 26.33% BCHJ c-Si solar cell revealed a 27%-efficiency is achievable using our technology. These results show the advantage of the BCHJ technology and provide a path to access new high-efficiency photovoltaic market for the c-Si solar cell.

Published
2017
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22. CLASSIFICATION OF STRAWBERRY FRUIT SHAPE BY MACHINE LEARNING

Author

Ishikawa, T., primary, Hayashi, A., additional, Nagamatsu, S., additional, Kyutoku, Y., additional, Dan, I., additional, Wada, T., additional, Oku, K., additional, Saeki, Y., additional, Uto, T., additional, Tanabata, T., additional, Isobe, S., additional, and Kochi, N., additional

Published
2018
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25. Anti-microbial Activities of Selected Ghanaian Medicinal Plants and Four Structurally Similar Anti-protozoan Compounds against Susceptible and Multi-drug Resistant Bacteria

Author

Antwi, A, primary, Owusu, K, additional, Amoa-Bosompem, M, additional, Williams, N, additional, Ayertey, F, additional, Akyeh, L, additional, Agyapong, J, additional, Tetteh, T, additional, Djameh, G, additional, Botchie, S, additional, Azerigyik, F, additional, Ablordey, A, additional, Tung, N, additional, Uto, T, additional, Appiah, A, additional, Iwanaga, S, additional, Shoyama, Y, additional, Ohta, N, additional, Egyir, B, additional, and Ohashi, M, additional

Published
2017
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26. Progress & Challenges in Thin-Film Silicon Photovoltaics: Heterojunctions & Multijunctions

Author

Yamamoto, K., Adachi, D., Uzu, H., Uto, T., Irie, T., Hino, M., Kanematsu, M., Kawasaki, H., Konishi, K., Mishima, R., Nakano, K., Terashita, T., Yoshikawa, K., Ichikawa, M., Kuchiyama, T., Suezaki, T., Meguro, T., Nakanishi, N., Yoshimi, M., Schroos, D., Valckx, N., Menou, N., and Hernández, J.L.

Subjects
Silicon-based Thin Film and Silicon-Heterojunction Solar Cells and Modules, THIN FILM SOLAR CELLS AND MODULES
Abstract

31st European Photovoltaic Solar Energy Conference and Exhibition; 1003-1005, Thin-film Si technology for solar cell has been developed for ~40 years. Improvement of efficiency and industrialization of thin-film Si solar cell have been realized by continuous research and development of the thinfilm Si technology. The thin-film Si technology covers a wide range of fields such as the fundamental understanding of the nature of thin-film Si, the cell/module production, the simulation, and the reliability technologies. These technologies are also significant for solar cells other than the thin-film Si solar cell. Thanks to the highly developed thin-film Si solar cell technology, we have achieved a certified efficiency of 25.1% by an aperture area measurement (area: 151.8 cm2) and an efficiency of 24.5% by a total area measurement (area: 239.0 cm2) using heterojunction (HJ) crystalline Si (c-Si) solar cells. These efficiencies are a record efficiency for c-Si cell with area of >150cm2 and a record power/wafer for c-Si solar cell with 6-inch semi-square wafer, respectively.

Published
2015
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27. High Efficiency Copper Electroplated Heterojunction Solar Cells and Modules – The Path towards 25% Cell Efficiency

Author

Hernández, J.L., Adachi, D., Schroos, D., Valckx, N., Menou, N., Uto, T., Hino, M., Kanematsu, M., Kawasaki, H., Mishima, R., Nakano, K., Uzu, H., Terashita, T., Yoshikawa, K., Kuchiyama, T., Hiraishi, M., Nakanishi, N., Yoshimi, M., and Yamamoto, K.

Subjects
WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY, Silicon Solar Cell Improvements
Abstract

28th European Photovoltaic Solar Energy Conference and Exhibition; 741-743, In this work, we present the latest results from Kaneka on high efficiency heterojunction crystalline silicon (c-Si) solar cells with a copper metallization scheme. We report copper plated heterojunction c-Si solar cells on 6 inch c-Si Cz wafers with a world record conversion on efficiency and generated power. Efficiencies of 24.2% (aperture area) and powers of 5.64 W (total area measurement) at 1 sun STC measurement have been certified by an independent laboratory. Values of open circuit voltage above 745mV, values of short circuit current above 40 mA/cm2, and values of fill factor above 82% have been reached. Results of the impact of the silicon wafer thickness on the efficiency of heterojunction c-Si solar cells are presented. Damp heat and thermal cycling reliability data of the copper electroplated heterojunction show comparable performance with Ag printed heterojunction. Temperature coefficient of -0.23%/ºC has been achieved which will translate in a higher total power of these devices under outdoor operation. We present the path toward efficiencies above 25% for low concentrations which combined with the good temperature coefficient show the potential of heterojunction technology for LCPV applications in warm climates.

Published
2013
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28. High Efficiency Copper Electroplated Heterojunction Solar Cells

Author

Hernández, J.L., Adachi, D., Yoshikawa, K., Schroos, D., Van Assche, E., Feltrin, A., Valckx, N., Menou, N., Poortmans, J., Yoshimi, M., Uto, T., Uzu, H., Hino, M., Kawasaki, H., Kanematsu, M., Nakano, K., Mishima, R., Kuchiyama, T., Koizumi, G., Allebé, C., Terashita, T., Hiraishi, M., Nakanishi, N., and Yamamoto, K.

Subjects
Wafer-Based Silicon Solar Cells and Materials Technology, Silicon Solar Cell Improvements
Abstract

27th European Photovoltaic Solar Energy Conference and Exhibition; 655-656, In this work, we present the latest result of the Cu electroplated heterojunction by Kaneka Corporation. The top electrode on heterojunction crystalline silicon (c-Si) solar cells usually defined by silver screen printing is replaced with a copper metallization scheme that has the potential to reduce the manufacturing cost while improving the heterojunction performance. We show the progress on the heterojunction c-Si solar cells by Kaneka and report on heterojunction c-Si solar cells on 6 inch wafers with a conversion efficiency of 23.5% independently confirmed by ISE-CALLAB (Voc = 737 mV, Jsc = 39.97 mA/cm2, FF = 79.77%). Heat-damp reliability tests show comparable performance for mini-modules fabricated with copper metalized as for conventional silver screen printed heterojunction c-Si solar cells.

Published
2012
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31. Magnetotelluric transect across the Niigata-Kobe Tectonic Zone, central Japan: A clear correlation between strain accumulation and resistivity structure

Author

Yoshimura, R., primary, Oshiman, N., additional, Uyeshima, M., additional, Toh, H., additional, Uto, T., additional, Kanezaki, H., additional, Mochido, Y., additional, Aizawa, K., additional, Ogawa, Y., additional, Nishitani, T., additional, Sakanaka, S., additional, Mishina, M., additional, Satoh, H., additional, Goto, T., additional, Kasaya, T., additional, Yamaguchi, S., additional, Murakami, H., additional, Mogi, T., additional, Yamaya, Y., additional, Harada, M., additional, Shiozaki, I., additional, Honkura, Y., additional, Koyama, S., additional, Nakao, S., additional, Wada, Y., additional, and Fujita, Y., additional

Published
2009
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35. Swimming depth of migrating silver eels Anguilla japonica released at seamounts of the West Mariana Ridge, their estimated spawning sites

Author

Aoyama, J., Hissmann, Karen, Yoshinaga, T., Sasai, S., Uto, T., Ueda, H., Aoyama, J., Hissmann, Karen, Yoshinaga, T., Sasai, S., Uto, T., and Ueda, H.

Abstract

Five hormone-treated female Japanese silver eels Anguilla japonica were tagged with ultrasonic transmitters and released by submersible in the West Pacific at seamounts of the West Mariana Ridge, their supposed spawning grounds. Four eels were tracked for 60 to 423 min in the vicinity of the seamounts. They did not settle at the seamounts but swam at a mean speed of 0.37 m s-1 into open water above deep ground. Their mean swimming depth ranged from 81 to 172 m. Experiments suggest that pre-matured A. japonica migrate to their spawning grounds in temperate warm water and at shallow depths.

Published
1999
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48. Eriobotryae folium extract suppresses LPS-induced iNOS and COX-2 expression by inhibition of NF-κB and MAPK activation in murine macrophages.

Author

Uto T, Suangkaew N, Morinaga O, Kariyazono H, Oiso S, and Shoyama Y

Abstract

Eriobotryae folium (EF), the dried leaves of Eriobotrya japonica (Thunb.) Lindl. has been traditionally used to treat various diseases such as chronic bronchitis, cough, inflammation, skin diseases, and diabetes. In this study, we examined the effects of Eriobotryae folium extract (EFE) on lipopolysaccharide (LPS)-induced production of nitric oxide (NO) and prostaglandin E2(PGE2) in RAW264 murine macrophage cells. EFE suppressed LPS-induced NO and PGE2 production in a dose-dependent manner. Consistent with these observations, EFE reduced the LPS-induced expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at both protein and mRNA levels. Furthermore, EFE significantly inhibited LPS-induced NF-κB binding activity, which was associated with the inhibition of IκB-α degradation. EFE also attenuated LPS-induced phosphorylation of mitogen-activated protein kinases (MAPKs) including extracellular signal-regulated kinase (ERK), p38 MAPK and c-Jun N-terminal kinase (JNK). These results suggest that the anti-inflammatory properties of EF might result from inhibition of iNOS and COX-2 expression through the downregulation of NF-κB activation and MAPK phosphorylation in LPS-stimulated RAW264 cells. [ABSTRACT FROM AUTHOR]

Published
2010
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49. Evaluation of a new eastern blotting technique for the analysis of ginsenoside Re in American ginseng berry pulp extracts.

Author

Morinaga O, Uto T, Yuan C, Tanaka H, and Shoyama Y

Abstract

A new eastern blotting technique has been established for ginsenoside Re (G-Re) contained in American ginseng berry pulp extracts. G-Re in American ginseng berry pulp was extracted using 100% methanol, 100% ethanol, 50% aqueous methanol, and 50% aqueous ethanol. The combined crude extracts were applied onto a polyethersulfone membrane and developed using the methanol-water-acetic acid solvent system (45:55:1 v/v). Separated components were immunostained using anti-G-Re monoclonal antibody. G-Re was first specifically detected and then quantitatively analyzed using NIH Imaging software. We also confirmed that the most suitable solvent was 50% aqueous methanol for extracting G-Re from American ginseng berry pulp. (c) 2009 Elsevier B.V. All rights reserved. [ABSTRACT FROM AUTHOR]

Published
2010
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50. Enzyme-linked immunosorbent assay for total sennosides using anti-sennside [sic] A and anti-sennoside B monoclonal antibodies.

Author

Morinaga O, Uto T, Sakamoto S, Tanaka H, and Shoyama Y

Abstract

Total sennosides concentration is a very important factor when rhubarb and senna will be used as crude drugs. However, one-step analytical technique for total sennosides has not been reported except HPLC. An enzyme-linked immunosorbent assay (ELISA) for total sennosides concentration by using the combination of anti-sennoside A (SA) and anti-sennoside B (SB) monoclonal antibodies (MAbs) in a single assay has been investigated. Total sennosides concentration in rhubarb and senna samples determined by newly developed assay system showed good agreement with those analyzed by ELISA using anti-SA MAb and anti-SB MAb, respectively. [ABSTRACT FROM AUTHOR]

Published
2009
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