609 research outputs found

    Deposition of boehmite on carbon nanofibers using aluminum alkoxide and its thermal transformation

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    We attempted to prepare carbon nanofibers (CNFs) bonded chemically with alumina particles using acid-treated CNFs and aluminum secbutoxide. The structure and morphology of the boehmite deposited on the CNFs, the boundary between the CNFs and the deposited boehmite, and the thermal transformation of the deposited boehmite were investigated using Raman spectroscopy, X-ray diffraction (XRD) analysis, field-emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The boehmite deposited not only particulately on the CNFs but also in a film-like manner on parts of the CNFs. In addition, the boehmite could deposit not only on the disordered inner walls of the CNFs but also on the ordered inner walls. By heating at 1200 degrees C, the boehmite on the CNFs was transformed into alpha-alumina and theta-alumina. At this time, some alumina particles, particularly those formed on the ordered inner walls of CNFs, fell out of the CNFs, and only those alumina particles which might chemically bond with CNFs remained on the CNFs. Finally, CNFs dotted with alumina particles with a size of <50 nm were obtained. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.ArticleCERAMICS INTERNATIONAL. 41(10):13171-13178 (2015)journal articl

    Three-dimensional semiautomatic liver segmentation method for non-contrast computed tomography based on a correlation map of locoregional histogram and probabilistic atlas

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    Background: We sought to evaluate a new regional segmentation method for use with three-dimensional (3D) non-contrast abdominal CT images and to report the preliminary results. Methods: The proposed method was evaluated in ten cases. Manually segmented areas were used as the gold standard for evaluation. To compare the standard and the extracted liver regions, the degree of coincidence R% was redefined by transforming a volumetric overlap error. We also evaluated the influence of varying the density window size in terms of setting the starting points. Results: We confirmed in ten cases that our method could segment the liver region more precisely than the conventional method. A size of window 15 voxels was optimal as the starting point in all cases. Conclusions: We demonstrated the accuracy of a 3D semiautomatic liver segmentation method for non-contrast CT. This method promises to offer radiologists a time-efficient segmentation aid.Yamaguchi S., Satake K., Yamaji Y., et al. Three-dimensional semiautomatic liver segmentation method for non-contrast computed tomography based on a correlation map of locoregional histogram and probabilistic atlas. Computers in Biology and Medicine 55, 79 (2014); https://doi.org/10.1016/j.compbiomed.2014.10.003

    Development of a glue-free bimorph mirror for use in vacuum chambers

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    PZT (lead zirconate titanate)-glued bimorph deformable mirrors are widely used in hard X-ray regimes; however, they have not yet been used in soft X-ray regimes because they are less compatible for usage under high vacuum. In this study, we developed a glue-free bimorph deformable mirror, in which silver nano-particles were employed to bond PZT actuators to mirror substrates. Under an appropriate bonding condition, the bonding layer was confirmed to be uniform and the mirror's bending characteristics were demonstrated to be sufficiently stable; its gas emission rate was also shown to be acceptable. Piezo responses before and after additional heating at 200 °C showed the thermal stability of its bonding and bending properties.Yoshio Ichii, Hiromi Okada, Hiroki Nakamori, Akihiko Ueda, Hiroyuki Yamaguchi, Satoshi Matsuyama, and Kazuto Yamauchi, "Development of a glue-free bimorph mirror for use in vacuum chambers", Review of Scientific Instruments 90, 021702 (2019), https://doi.org/10.1063/1.5066105
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