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51.
It has been found that tack values of pressure-sensitive adhesives are dependent on the surface energies for adherends. The parabolic curves with maxima are obtained from the plots of tack values versus critical surface tensions for the substrates. The maximum occurs at the region where the two surface tensions are almost similar. On the other hand, tack is measured as a dynamic value indicated as the force necessary to deform the adhesive mass. To explain why the tack values is controlled by the surface character of the adherend, a mechanism is proposed for adhesive bond breaking. Primarily, bonding occurs by wetting the surface with adhesive. When the adhesive bond breaks by external force, unbonding proceeds from the viscoelastic deformation of the adhesive mass around the wetted spots on the surface of the adherend. As the total area of wetted spots is determined by surface energy, the tack value is dependent on the critical surface tension of the adherend. 相似文献
52.
Taku Michael Aida Yukiko Sato Masaru Watanabe Kiyohiko Tajima Toshiyuki Nonaka Hideo Hattori Kunio Arai 《The Journal of Supercritical Fluids》2007,40(3):381-388
Reaction of d-glucose in water to yield 5-hydroxymethylfurfural (5-HMF), 1,2,4-benzenetriol (BTO) and furfural was studied at high temperatures (up to 400 °C) and high pressures (up to 80 MPa) using a continuous flow reactor. Maximum temperature and pressure conditions gave maximum furfural yield. Increasing pressure from 40 to 70 and 80 MPa enhanced dehydration reactions to 5-HMF, but also enhanced hydrolysis of 5-HMF leading to the production of BTO and thus lead to lower yields of 5-HMF (below 10%). Remarkably, the dehydration reaction to 5-HMF and the hydrolysis of 5-HMF were both enhanced by the increase in water density at 400 °C. 相似文献
53.
Kazuhiro Akiyama Nosho Toyama Kazuyoshi Muraoka Makoto Tsunashima 《Journal of the American Ceramic Society》1998,81(4):1071-1073
The physical and chemical configuration of anatase-form titanium dioxide pigment particles was investigated with a field-emission gun using transmission electron microscopy and energy-dispersive spectroscopy (EDX). The particle was ∼0.2 µm in average size and had an amorphous-surface-layer thickness of 1-2 nm around the single-crystallized matrix. Niobium that had segregated in the amorphous surface layer was detected via EDX analysis. 相似文献
54.
Masahiko Satoh Tamie Suzuki Tetsuhito Sakurai Sumika Toyama Yayoi Kamata Shinya Kondo Yasushi Suga Mitsutoshi Tominaga Kenji Takamori 《International journal of molecular sciences》2021,22(19)
Neuronal morphological changes in the epidermis are considered to be one of causes of abnormal skin sensations in dry skin-based skin diseases. The present study aimed to develop an in vitro model optimised for human skin to test the external factors that lead to its exacerbation. Human-induced pluripotent stem cell-derived sensory neurons (hiPSC-SNs) were used as a model of human sensory neurons. The effects of chemical substances on these neurons were evaluated by observing the elongation of nerve fibers, incidence of blebs (bead-like swellings), and the expression of nicotinamide mononucleotide adenylyl transferase 2 (NMNAT2). The nerve fiber length increased upon exposure to two common cosmetic preservatives—methylparaben and phenoxyethanol—but not to benzo[a]pyrene, an air pollutant at the estimated concentrations in the epidermis. Furthermore, the incidence of blebs increased upon exposure to benzo[a]pyrene. However, there was a decrease in the expression of NMNAT2 in nerve fibers, suggesting degenerative changes. No such degeneration was found after methylparaben or phenoxyethanol at the estimated concentrations in the epidermis. These findings suggest that methylparaben and phenoxyethanol promote nerve elongation in hiPSC-SNs, whereas benzo[a]pyrene induces nerve degeneration. Such alterations may be at least partly involved in the onset and progression of sensitive skin. 相似文献
55.
Takehiro Kaneko Yasuhiro Watanuki Takeshi Toyama Yoshiyuki Kojima Nobuyuki Nishimiya 《International Journal of Hydrogen Energy》2017,42(15):10014-10022
In order to enhance hydrogen storage capacity of carbonaceous materials through metal modification, FeNiCr-carbon composites were prepared by calcination of Fe, Ni and Cr-containing polyacrylonitrile (PAN) fibers fabricated by electrospinning method. Fe (III), Ni (II) and Cr (III) acetylacetonates (M (acac)n) were selected as metal sources. Increase of specific surface area and formation of micropores were observed on heat decomposition of M (acac)n particularly through introduction of steam. Maximal hydrogen content, 1.62 mass%, was obtained at 77 K under 0.8 MPa of hydrogen for a FeNiCr-carbon composite, which contained about 15.5 mass% of metals and had specific surface area of 501 m2 g?1. The hydrogen content exceeded the hydrogen physisorption limit, 2.34 mass% per 1000 m2 g?1, which was calculated on the basis of the commensurate–incommensurate transition with an enhancing factor ρ of 1.126. After hydrogenation at 653 K, no hydrogen desorption peaks were observed for FeNiCr powders derived from M (acac)n, and one peak at 828 K for a carbonaceous sample prepared from unmodified PAN fibers. From the most promising FeNiCr-carbon composite, another peak was recorded at 752 K in addition to the peak at 828 K. The former would be originated from hydrogen on novel sorption sites additionally created on the composite formation. 相似文献
56.
Sumika Toyama Mitsutoshi Tominaga Kenji Takamori 《International journal of molecular sciences》2021,22(22)
Although histamine is a well-known itch mediator, histamine H1-receptor blockers often lack efficacy in chronic itch. Recent molecular and cellular based studies have shown that non-histaminergic mediators, such as proteases, neuropeptides and cytokines, along with their cognate receptors, are involved in evocation and modulation of itch sensation. Many of these molecules are produced and secreted by immune cells, which act on sensory nerve fibers distributed in the skin to cause itching and sensitization. This understanding of the connections between immune cell-derived mediators and sensory nerve fibers has led to the development of new treatments for itch. This review summarizes current knowledge of immune cell-derived itch mediators and neuronal response mechanisms, and discusses therapeutic agents that target these systems. 相似文献
57.
A. Kuramoto T. Toyama Y. Nagai K. Inoue Y. Nozawa M. Hasegawa M. Valo 《Acta Materialia》2013,61(14):5236-5246
We present a microstructural study of a surveillance test specimen from a reactor pressure vessel steel of a Russian-type nuclear reactor after neutron irradiation, post-irradiation annealing and re-irradiation, using atom probe tomography (APT) and positron annihilation spectroscopy (PAS). The APT results showed the formation of Cu-rich solute nano-clusters (CRCs) during the initial irradiation and their subsequent coarsening during annealing. After re-irradiation, new CRCs have been observed. The irradiation-hardening almost recovered during annealing. However, by re-irradiation, hardening comparable to that by the initial irradiation was observed. The hardening due to the CRCs formed during the initial irradiation, estimated using the Russell–Brown model, was almost the same as that observed. However, the estimated hardening after the re-irradiation was about half of the measured one. The other hardening is attributed to the newly formed MDs by the re-irradiation, which was evidenced by PAS. 相似文献
58.
Toyama T Murashita M Kobayashi K Kikuchi S Sei K Tanaka Y Ike M Mori K 《Environmental science & technology》2011,45(15):6524-6530
We investigated biodegradation of technical nonylphenol (tNP) in Phragmites australis rhizosphere sediment by conducting degradation experiments using sediments spiked with tNP. Accelerated tNP removal was observed in P. australis rhizosphere sediment, whereas tNP persisted in unvegetated sediment without plants and in autoclaved sediment with sterile plants, suggesting that the accelerated tNP removal resulted largely from tNP biodegradation by rhizosphere bacteria. Three bacterial strains, Stenotrophomonas sp. strain IT-1 and Sphingobium spp. strains IT-4 and IT-5, isolated from the rhizosphere were capable of utilizing tNP and 4-tert-octylphenol as a sole carbon source via type II ipso-substitution. Oxygen from P. australis roots, by creating highly oxygenated conditions in the sediment, stimulated cell growth and the tNP-degrading activity of the three strains. Moreover, organic compounds from P. australis roots functioned as carbon and energy sources for two strains, IT-4 and IT-5, supporting cell growth and tNP-degrading activity. Thus, P. australis roots elevated the cell growth and tNP-degrading activity of the three bacterial strains, leading to accelerated tNP removal. These results demonstrate that rhizoremediation of tNP-contaminated sediments using P. australis can be an effective strategy. 相似文献
59.
Shouji Sugimura Tadashi Naitoh Atsushi Toyama Fumihiko Ohta 《Electrical Engineering in Japan》2013,182(1):18-29
There are many PWM control devices, which are higher harmonics current sources, in distribution systems, and higher harmonics cause overcurrents by parallel resonance. To avoid overcurrents, it is necessary to suppress resonance. In this paper, a new suppression method, which uses the effect of source connected points in resonance circuits, is proposed. First it shows that the optimal point, which gives a minimum current amplification degree, is orthogonal to the static condenser voltage. Then, using the eigenvector of the state equation, the participation factor is defined. When the participation factor is zero, the orthogonality condition is introduced. Therefore, the optimal point is obtained with the participation factor. Finally, numerical investigation shows that multiple optimal points usually exist. Therefore, we can choose the most advantageous point as a source‐connected node. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 182(1): 18–29, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22307 相似文献
60.
• | Analyzing the nature of competitive interaction among multinational firms in the tire industry, we find that the histories of the interactions between particular rivals matter. |
• | The decision to enter a new foreign market in the era of global consolidation is related to the identities of rivals in the market, characteristics of the firm and the market, and the extent of past competitive interactions with the international pioneering firm. |
• | Results suggest that, in an oligopolistic environment, aspects of multimarket competition are important to foreign direct investment decisions. |