HIGH TEMPERATURE STRENGTH OF HYDROGEN ANNEALED SILICON WAFER

Matsushita, J.,Xin, P.,Hayashi, K.,Fujii, O.,Kawamura, N.,Kawakami, T.,Numano, M.,Kubota, H.,Matsushita, Y. 한국재료학회 1995 Fabrication and Characterization of Advanced Mater Vol.1 No.1

High temperature strength of hydrogen annealed silicaon wafer was investiaged. Wafers were 150mm in diameter, Czochralski-grown(100) silicon crystal. Silicon wafers were annealed at $1200^{\circ}C$ for 1 hour in a hydrogen atmosphere with a heating rate of $10^{\circ}C/min$ and $20^{\circ}C/min$ in an hot-wall furnace. Oxygen precipitate density in slow heating rate sample and rapid heating rate sample were $2{\times}10^{9}/cm^3$ and $3{\times}10^{7}/cm^3$, respectively. Decreasing the heating rate increases the oxygen precipitate density. The strength was measured by the three-point bending test at $1000^{\circ}C$ using strip-shpaped samples cult from silicon wafer. The maximum resolved shear stress($T_{max}$) at the specimen surface converted from the maximum load was dependent on strain rate and oxygen precipitate density constained in the silicon wafer. The $T_{max}$, 20.5 MPa for as-received samples, was reduced to 17.9MPa in slow heating rate sample. On the other hand, the $T_{max}$ was almost the same as 20.3 MPa in rapid heating rate sample under a strain rate of $6.9{\times}10^{-6}/s$ at $1000^{\circ}C$.

Recent use of deep learning techniques in clinical applications based on gait: a survey

Matsushita Yume,Tran Dinh Tuan,Yamazoe Hirotake,Lee Joo-Ho 한국CDE학회 2021 Journal of computational design and engineering Vol.8 No.6

Gait analysis has been studied for a long time and applied to fields such as security, sport, and medicine. In particular, clinical gait analysis has played a significant role in improving the quality of healthcare. With the growth of machine learning technology in recent years, deep learning-based approaches to gait analysis have become popular. However, a large number of samples are required for training models when using deep learning, where the amount of available gait-related data may be limited for several reasons. This paper discusses certain techniques that can be applied to enable the use of deep learning for gait analysis in case of limited availability of data. Recent studies on the clinical applications of deep learning for gait analysis are also reviewed, and the compatibility between these applications and sensing modalities is determined. This article also provides a broad overview of publicly available gait databases for different sensing modalities.

Experimental and Numerical Investigations on Performances of Darriues-type Hydro Turbine with Inlet Nozzle

Matsushita, Daisuke,Tanaka, Kei,Watanabe, Satoshi,OKuma, Kusuo,Furukawa, Akinori Korean Society for Fluid machinery 2014 International journal of fluid machinery and syste Vol.7 No.4

Low head hydropower is one of realistic renewable energies. The Darrieus-type hydro turbine with an inlet nozzle is available for such low head conditions because of its simple structure with easy maintenance. Experimental and numerical studies are carried out in order to examine the effects of gap distances between the runner pitch circle and two edges of inlet nozzle on turbine performances. By selecting narrower gaps of left and right edges, the performance could be improved. From the results of two dimensional numerical simulations, the relation between the performance and flow behaviors around the Darrieus blade are discussed to obtain the guideline of appropriate inlet nozzle design.

Design of flux pinning property in REBCO coated conductors with artificial pinning centers

Matsushita, Teruo,Kiuchi, Masaru The Korea Institute of Applied Superconductivity a 2018 한국초전도저온공학회논문지 Vol.20 No.1

The improvement of critical current properties of $REBa_2Cu_3O_{7-x}$ (REBCO) coated conductors by introducing artificial pinning centers (APCs) is examined with respect to the field-angle anisotropy, high-field performance and relaxation property with time. Nano-rods along the c-axis introduced by PLD method and isotropic nano-particles introduced by TFA-MOD method are treated. The theoretical analysis is also shown to understand the effect of APCs quantitatively. The effects of superconducting layer thickness that influences the high-field performance and relaxation property are also discussed. It is shown that the upper critical field, which is another important factor to determine the high-field property, can be improved by introduction of APCs through electron scattering at interfaces with the superconducting matrix. The optimum critical current property can be obtained by properly designing the morphology and number density of APCs and the superconducting layer thickness.

Development of innovative superconducting DC power cable

Matsushita, Teruo,Kiuchi, Masaru The Korea Institute of Applied Superconductivity a 2017 한국초전도저온공학회논문지 Vol.19 No.3

It is required to reduce the cost of superconducting cable to realize a superconducting DC power network that covers a wide area in order to utilize renewable energy. In this paper a new concept of innovative cable is introduced that can enhance the current-carrying capacity even though the same superconducting tape is used. Such a cable can be realized by designing an optimal winding structure in such a way that the angle between the tape and magnetic field becomes small. This idea was confirmed by preliminary experiments for a single layer model cable made of Bi-2223 tapes and REBCO coated conductors. Experiments of three and four layer cables of practical sizes were also done and it was found that the current-carrying capacity increased as theoretically predicted. If the critical current properties of commercial superconducting tapes are further improved in a parallel magnetic field, the enhancement will become pronounced and this technology will surely contribute to realization of superconducting DC power network.

Excellent Crystallinity of Ba Ferrite Layers Deposited on Pt(111) Underlayers

Matsushita, Nobuhiro,Feng, Jie,Watanabe, Koh,Ichinose, Makoto,Nakagawa, Shigeki,Naoe, Masahiko The Korean Ceramic Society 2000 The Korean journal of ceramics Vol.6 No.3

A magnetoplumbite type of Ba ferrite(BaM) layers were deposited on Pt(111) and Pt(200) layers, and their c-axis orientation and magnetic characteristics were compared each other. The as-deposited BaM layer on Pt(111) one at the substrate temperature $T_s$ above $500^{\circ}C$ revealed remarkable c-axis orientation. The saturation magnetization 4$\piM_s$ and the perpendicular coercivity $H_{c⊥}$ of the films as-deposited at $T_s$ of $600^{\circ}C$ were 4.0kG and 2.5kOe, respectively. On the other hand, BaM ferrite layer deposited on Pt(200) layer at $T_s$ as relatively low as $500^{\circ}C$ also revealed weak c-axis orientation as well as (107) one and the films as-deposited at $T_s$ of $600^{\circ}C$ exhibited 4$\piMs_{and}$ $H_{c⊥}$ of 2.8kG and 2.5kOe, respectively. It was suggested that although chemical activity of Pt surface was effective for the formation of BaM crystallites, the lattice matching was also important for obtaining BaM layer with good c-axis orientation and large perpendicular anisotropy.sotropy.

Firmicutes in Gut Microbiota Correlate with Blood Testosterone Levels in Elderly Men

Matsushita Makoto,Fujita Kazutoshi,Motooka Daisuke,Hatano Koji,Hata Junya,Nishimoto Mitsuhisa,Banno Eri,Takezawa Kentaro,Fukuhara Shinichiro,Kiuchi Hiroshi,Pan Yue,Takao Toshifumi,Tsujimura Akira,Yach 대한남성과학회 2022 The World Journal of Men's Health Vol.40 No.3

Purpose: In males, testosterone levels have been implicated in various diseases. Recently, the influence of gut microbialderived compounds on host metabolism has become evident, and it has been suggested that some gut bacteria may be involved in testosterone metabolism. In the present study, we examined the relationship between testosterone levels and gut microbiota in elderly Japanese men. Materials and Methods: We collected samples from Japanese male subjects suspected of having prostate cancer and underwent prostate biopsies and excluded patients with positive biopsies to avoid the effect of prostate cancer on the gut microbiota. In total, 54 Japanese males with negative biopsy results were included in our study. The gut microbiota was analyzed by 16S rRNA gene sequencing of bacterial DNA extracted from rectal swabs. Gut microbiota compositions were compared between the two groups according to the level of serum testosterone (above or below 3.5 ng /mL). Results: The median age of the cohort was 71 years, and the quartile range was 67 to 73 years. We observed no significant difference in alpha or beta diversity, but some bacteria belonging to the phylum Firmicutes (Clostridiales, Turicibacter, and Gemella) were increased in the high testosterone group. Serum testosterone levels positively correlated with the relative amount of Firmicutes (rS=0.3323, p=0.0141), and the amount of Firmicutes affected serum testosterone levels independent of host factors (age, body mass index, triglyceride, and total cholesterol; β=0.770, p=0.0396). Conclusions: Some intestinal bacteria belonging to the phylum Firmicutes were associated with testosterone levels in elderly males. Therefore, the gut microbiota could affect testosterone metabolism in elderly males.

ASIAA EXTRAGALACTIC STUDY WITH THE SMA

MATSUSHITA SATOKI,MAO RUI-QING,MULLER SEBASTIEN,CHOU CHUEN- YI,SAWADA-SATOH SATOKO,TRUNG DINH-VAN,LIM JEREMY,HSIEH PEI-YING,PECK ALISON B. The Korean Astronomical Society 2005 Journal of The Korean Astronomical Society Vol.38 No.2

We present CO(3-2), CO(2-1), and 230 GHz (1.3 mm) continuum images of nearby galaxies taken with the Submillimeter Array (SMA). Our main topic is to study the relation between higher-J molecular gas (e.g., CO J=3-2, 2-1) and nuclear activities (e.g., active galactic nuclei [AGNs] and starbursts). The nearby Seyfert 2 galaxy M51 shows strong CO(3-2) emission from the circumnuclear molecular gas, with an intensity twice as strong as that of the CO(1-0) emission. Strong CO(3-2) emission enhancement suggests that the circum nuclear molecular gas in M51 is warm and dense, which may be related to the AGN activities. Molecular gas in the nearby moderate starburst galaxy NGC 6946 is distributed along the large-scale bar or spiral arms and along the minibar, and the multi-J CO line images show very similar distribution to each other. For this galaxy, there is no clear enhancement in higher-J lines as seen in M51, which may be because NGC 6946 does not have clear AGN activities. Based on the results of these two galaxies, the physical conditions of the circum nuclear molecular gas may be related to the AGN activities. We also observed the nearby edge-on starburst galaxy NGC 3628 and the starburst/Seyfert composite galaxy NGC 4945 with the CO(2-1) line and 230 GHz (1.3 mm) continuum emission. These information will give us some hints for understanding the relation between nuclear activities and circum nuclear molecular gas and dust.

MOLECULAR GAS AND RADIO JET INTERACTION: A CASE STUDY OF THE SEYFERT 2 AGN M51

MATSUSHITA, SATOKI,TRUNG, DINH-V,BOONE, FRDERIC,KRIPS, MELANIE,LIM, JEREMY,MULLER, SEBASTIEN The Korean Astronomical Society 2015 天文學論叢 Vol.30 No.2

We observed multiple CO transition lines and the HCN(1-0) line at ~ 1" (~ 34 pc) or higher resolution toward the Seyfert 2 nucleus of M51 using the IRAM Plateau de Bure Interferometer (PdBI) and the Submillimeter Array (SMA). All the images show very similar overall molecular gas distribution; there are two discrete clouds at the eastern and western sides of the nucleus, and the western cloud exhibits an elongated distribution and velocity gradient along the radio jet. In addition, high HCN(1-0)/CO(1-0) brightness temperature ratios of about unity have been observed, especially along the radio jet, similar to those observed in shocked molecular gas in our Galaxy. This strongly indicates that the molecular gas along the jet is shocked, that the radio jet and the molecular gas are interacting, and the jet is entraining both diffuse (CO) and dense (HCN) molecular gas outwards from the circumnuclear region. This is the first clear imaging of the outflowing molecular gas entrained by the AGN jet, and showing the detailed physical status of outflowing molecular gas. Since a relatively high HCN(1-0)/CO(1-0) ratio has been observed in the high velocity wing of ultraluminous infrared galaxies, it can also be explained by a similar mechanism to those we describe here.

Soluble Host-Defense Lectins

Matsushita, Misao,Kilpatrick, David C.,Lee, Bok Luel,Wakamiya, Nobutaka Hindawi Publishing Corporation 2012 Journal of biomedicine & biotechnology Vol.2012 No.-