77 research outputs found

    Dense ceramic coatings deposited by aerosol deposition for multilayered architecture towards thermal/environmental barrier coatings

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    The demands for thermal/environmental barrier coatings (T/EBCs) have been increased as the operating temperature of gas turbines increased in harsh environment [1]. Multilayered and multifunctional coatings are required for advanced T/EBCs [2], varied from porous insulative layer to dense environmental barrier layer. Aerosol deposition (AD) method is a unique deposition method that enables the deposition of dense ceramic coatings with high adhesion strength without melting of injected powder based on room temperature impact consolidation (RTIC) phenomena [3-5]. Thus, it will be interesting to apply this process for T/EBC applications. However, in order to apply the AD method to these applications, the deposition rate and the ability of three-dimensional coverage should be improved. Mori et al. preliminary reported that the introduction of plasma assistance drastically improved the deposition rate for lead zirconate titanate [6]. Thus, it would be worth to try to enhance aerosol deposition by introduction of plasma assistance [7]. The use of mesoplasma flow, which is transitional state from thermal plasma to low-pressure plasma, is the key to the deposition [8]. Fine powder of 8-wt% yttria-stabilized zirconia was sprayed by an rf-inductively coupled plasma at a reduced pressure. The effect of plasma assistance was confirmed at the power input of several kilowatts, which was much smaller compared to conventional plasma spray. Coatings with uniform thickness of 5-20 µm was obtained. The Vickers hardness of the coating reached to 1200 HV. This coating will be useful for the architecture of multilayered advanced T/EBCs. References [1] J. M. Drexler et al., Adv. Mater., 23 (2011) 2419-2424. [2] V. Viswanathan et al., J. Am. Ceram. Soc., 97 (2014) 2770-2778. [3] J. Akedo and M. Levedev, Jpn. J. Appl. Phys. Part 1, 38 (1999) 5397-5401. [4] J. Akedo, J. Am. Ceram. Soc. 89 (2006) 1834-1839. [5] J. Akedo, J. Therm. Spray Technol. 17 (2008) 181-198. [6] M. Mori et al., Proc. IEEE Int. Symp. Appl. Ferroelectric. 1-2 (2007) 454-456. [7] A. Vardelle et al., J. Therm. Spray Technol. 25 (2016) 1376-1440 (J. Akedo and K. Shinoda, Section 2.2, 1379-1383). [8] T. Yoshida, Pure Appl. Chem. 78 (2006) 1093-1107

    Intangible Investment in Japan: New Estimates and Contribution to Economic Growth

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    The purpose of this paper is to measure intangible assets, to construct the capital stock of intangible assets, and to examine the contribution of intangible capital to economic growth in Japan. We follow the approach of Corrado, Hulten, and Sichel (2005, 2006) to measure intangible investment using the 2008 version of the Japan Industrial Productivity (JIP) Database. We find that the ratio of intangible investment to GDP in Japan has risen during the past 20 years and now stands at 11.6%, which is lower than the ratio estimated for the United States in the early 2000s. The ratio of intangible to tangible investment in Japan is also lower than equivalent values estimated for the United States. In addition, we find that, in stark contrast with the United States, where intangible capital grew rapidly in the late 1990s, the growth rate of intangible capital in Japan declined from the late 1980s to the early 2000s. In order to examine the robustness of our results, we also conducted a sensitivity analysis and found that the slowdown of the contribution of intangible capital deepening to economic growth and the recovery in Multi-Factor Productivity (MFP) growth from the second half of the 1990s observed in our base case remain unchanged even if we take on-the-job training and Japanese data with respect to investment in firm-specific resources into account.intangible investment, labor productivity, growth accounting

    Analysis of Radioactive Elements in Testes of Large Japanese Field Mice Using an Electron Probe Micro-Analyser after the Fukushima Accident

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    The Fukushima Daiichi nuclear power plant (FDNPP) accident drew global attention to the health risks of radiation exposure. The large Japanese field mice (Apodemus speciosus) are rodents endemic to, and distributed throughout, Japan. This wild rodent live in and around the ex-evacuation zone on the ground surface and/or underground. In this study, we evaluated the effect of chronic radiation exposure associated with FDNPP accident on the testes of large Japanese field mice. Morphological analysis and electron-prove X-ray microanalysis (EPMA) was undertaken on the testes. Morphological analysis of testes based on H&E staining showed that the spermatogenesis was observed normally in the breeding season of wild mice in the heavily contaminated area. However, caesium (Cs) was not detected in all testes of wild mice from FDNPP ex-evacuation zone. In conclusion, even if the testes and the process of spermatogenesis are hypersensitive to radiation, we could not detect radiation effects on the spermatogenesis and Cs in the examined large Japanese field mice testes following chronic radiation exposure associated with the FDNPP accident

    Hyperadiponectinemia enhances bone formation in mice

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    <p>Abstract</p> <p>Background</p> <p>There is growing evidence that adiponectin, a physiologically active polypeptide secreted by adipocytes, controls not only adipose tissue but also bone metabolism. However, a role for adiponectin in bone development remains controversial.</p> <p>Methods</p> <p>We therefore investigated the endocrine effects of adiponectin on bone metabolism using 12-week-old male transgenic (Ad-Tg) mice with significant hyperadiponectinemia overexpressing human full-length adiponectin in the liver.</p> <p>Results</p> <p>In Ad-Tg mice, the serum level of osteocalcin was significantly increased, but the levels of RANKL, osteoprotegerin, and TRAP5b were not. Bone mass was significantly greater in Ad-Tg mice with increased bone formation. In contrast, bone resorption parameters including the number of osteoclasts and eroded surface area did not differ between Ad-Tg and their littermates.</p> <p>Conclusions</p> <p>These findings demonstrate that hyperadiponectinemia enhances bone formation in mice.</p

    厚膜技術の必要性と最新動向

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    Characterization of Deformation Behavior of Individual Grains in Polycrystalline Cu-Al-Mn Superelastic Alloy Using White X-ray Microbeam Diffraction

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    White X-ray microbeam diffraction was applied to investigate the microscopic deformation behavior of individual grains in a Cu-Al-Mn superelastic alloy. Strain/stresses were measured in situ at different positions in several grains having different orientations during a tensile test. The results indicated inhomogeneous stress distribution, both at the granular and intragranular scale. Strain/stress evolution showed reversible phenomena during the superelastic behavior of the tensile sample, probably because of the reversible martensitic transformation. However, strain recovery of the sample was incomplete due to the residual martensite, which results in the formation of local compressive residual stresses at grain boundary regions

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    Microglia cause structural remodeling of noradrenergic axon in the trigeminal spinal subnucleus caudalis after infraorbital nerve injury in rats

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    The dysfunction of descending noradrenergic (NAergic) modulation in second-order neurons has long been observed in neuropathic pain. In clinical practice, antidepressants that increase noradrenaline levels in the synaptic cleft are used as first-line agents, although adequate analgesia has not been occasionally achieved. One of the hallmarks of neuropathic pain in the orofacial regions is microglial abnormalities in the trigeminal spinal subnucleus caudalis (Vc). However, until now, the direct interaction between descending NAergic system and Vc microglia in orofacial neuropathic pain has not been explored. We found that reactive microglia ingested the dopamine-β-hydroxylase (DβH)-positive fraction, NAergic fibers, in the Vc after infraorbital nerve injury (IONI). Major histocompatibility complex class I (MHC-I) was upregulated in Vc microglia after IONI. Interferon-γ (IFNγ) was de novo induced in trigeminal ganglion (TG) neurons following IONI, especially in C-fiber neurons, which conveyed to the central terminal of TG neurons. Gene silencing of IFNγ in the TG reduced MHC-I expression in the Vc after IONI. Intracisternal administration of exosomes from IFNγ-stimulated microglia elicited mechanical allodynia and a decrease in DβH in the Vc, which did not occur when exosomal MHC-I was knocked down. Similarly, in vivo MHC-I knockdown in Vc microglia attenuated the development of mechanical allodynia and a decrease in DβH in the Vc after IONI. These results show that microglia-derived MHC-I causes a decrease in NAergic fibers, culminating in orofacial neuropathic pain
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