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41.
The modeling of particle aggregation under a simple shear flow and the extension of the model to a stirred vessel is described. The model quantitatively demonstrates the change of the number of aggregates with time for each shear rate. This number increased with higher shear rate and, conversely, the aggregate size became small when raising the shear rate. This was because aggregates were broken by the stronger shear force. The number of aggregates for different impellers was determined. The shear rate was back‐calculated from the experimentally obtained aggregate size and the model equation. This shear rate was different from that estimated from the Metzner‐Otto method, consequently, some revisions of the Metzner‐Otto equation might be necessary for its application to particle aggregation. 相似文献
42.
43.
Takashi Kanno Changmin Kim Daisuke Yamanaka Ken-ichi Ishibashi Hiroshi Tanaka Naohito Ohno Yoshiyuki Adachi 《International journal of molecular sciences》2021,22(4)
Because Japanese cedar pollen (JCP) contains beta-1,3-d-glucan (BG), there is concern that its lingering presence in the atmosphere, especially during its scattering period, may cause false positives in the factor-G-based Limulus amebocyte lysate (LAL) assay used to test for deep mycosis (i.e., G-test). Hence, we examined whether the LAL assay would react positively with substances contained in JCP by using the G-test to measure JCP particles and extracts. BG was purified from the JCP extract on a BG-specific affinity column, and the percentage extractability was measured using three different BG-specific quantitative methods. The G-test detected 0.4 pg BG in a single JCP particle and 10 fg from a single particle in the extract. The percentage extractability of JCP-derived BG was not significantly different among the three quantitative methods. As the JCP particles should technically have been removed during serum separation, they should be less likely to be a direct false-positive factor. However, given that the LAL-assay-positive substances in the JCP extract were not distinguishable by the three BG-specific quantitative methods, we conclude that they may cause the background to rise. Therefore, in Japan false positives arising from JCP contamination should be considered when testing patients for deep mycosis. 相似文献
44.
45.
Dynamic mechanical properties of three‐component composites (acrylic polymer/epoxy/SiO2) in the glass‐transition region 下载免费PDF全文
Hideyuki Uematsu Takashi Nishimoto Shuichi Tanoue Yoshiyuki Iemoto Yuji Aoki Masataka Sugimoto Kiyohito Koyama 《应用聚合物科学杂志》2014,131(13)
In previous studies, we reported the linear and nonlinear rheological properties of three‐component composites consisting of acrylic polymer (AP), epoxy resin (EP), and various SiO2 contents (AP/EP/SiO2) in the molten state. In this study, the dynamic mechanical properties of AP/EP/SiO2 composites with different particle sizes (0.5 and 8 μm) were investigated in the glass‐transition region. The EP consisted of three kinds of EP components. The α relaxation due to the glass transition shifted to a higher temperature with an increase in the volume fraction (?) for the AP/EP/SiO2 composites having a particle size of 0.5 μm, but the α relaxation scarcely shifted for the composite having a particle size of 8 μm as a general result. This result suggested that the SiO2 nanoparticles that were 0.5 μm in size adsorbed a lot of the low‐glass‐transition‐temperature (Tg) component because of their large surface area. The AP/SiO2 composites did not exhibit a shift in Tg; this indicated that the composite did not adsorb any component. The modulus in the glassy state (E′g) exhibited a very weak &phis; dependence for the AP/EP/SiO2 composites having particle sizes of 0.5 and 8 μm, although E′g of the AP/SiO2 composites increased with &phis;. The AP/EP/SiO2 composites exhibited a peculiar dynamic mechanical behavior, although the AP/SiO2 composites showed the behavior of general two‐component composites. Scanning electron microscopic observations indicated that some components in the EP were adsorbed on the surface of the SiO2 particles. We concluded that the peculiar behavior of the AP/EP/SiO2 composites was due to the selective adsorption of the EP component. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40409. 相似文献
46.
Ruri Hidema Hiroshi Suzuki Shion Hisamatsu Yoshiyuki Komoda 《American Institute of Chemical Engineers》2014,60(5):1854-1862
An experimental study has been performed to investigate the relationship between the extensional viscosity of polymers and the turbulent drag reduction. Self‐standing flowing soap film was used to generate two‐dimensional (2‐D) turbulent flow to eliminate shear stress. Two types of polymers having different flexibilities were added to the 2‐D turbulence. The effects of these polymers were visualized by the interference pattern of flowing soap films. The vortex deformation by adding polymers was analyzed by Fourier transformation and wavelet transformation. The scaling exponents of the power spectrum of interference patterns indicate that the mechanism of turbulence laminarization due to the extensional viscosity is anisotropic. A wavelet analysis reveals the high and low fluctuations of the polymer‐added flow. Results from wavelet analysis indicate disappearing of original vortices, and appearing of new structures in low frequency in 2‐D flow. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1854–1862, 2014 相似文献
47.
We fabricated high performance films using cellulose butyral (CB) synthesized from native cellulose. Two-step reactions were adopted to produce the derivative CB, including etherification of cellulose with glycidol in NaOH/urea aqueous solution to yield O-(2,3-dihydroxypropyl) cellulose (DHPC), and butyralization of DHPC. Both DHPC and CB products were easily processed into a thin film by hot-press molding. The butyral modifier significantly improved the tenacity of highly ductile DHPC, by virtue of the possible chain-entangling action of the ring structures in the stretching process. Thereby the film toughness was markedly enhanced. The CB films exhibited excellent optical transparency and a good adhesive property to glass plates. Thus the films may be comparable to commercial poly(vinyl butyral) (PVB) films in optical and mechanical performances and therefore possess a potential applicability as interlayer for laminated glasses. 相似文献
48.
Yin Zhang Jianan Ai Dinggai Wang Zhongrong Hong Wenhui Li Yoshiyuki Yokogawa 《Ceramics International》2013
Biphasic calcium phosphate (BCP) bimodal porous ceramics were prepared from a mixture of fine powders of hydroxyapatite (HAp) and beta-tricalcium phosphate (β-TCP) with varying HAp/β-TCP ratios. Two types of HAp powders and one type of β-TCP powder were used to produce porous BCP bioceramics with HAp/β-TCP weight ratios of 20/80, 40/60, and 80/20. Dissolution tests were performed to compare the dissolution properties of BCP-based bioceramics with different structural properties. Porous ceramic samples of approximately 0.5 g were individually soaked in 30 ml of simulated body fluid (SBF) solution at 36.5 °C for 1, 3, 7 and 10 days, respectively. The calcium content of the SBF solution was analyzed by ICP. The porous bodies were filtered, dried, and characterized using SEM, XRD, and FT-IR. The results indicate that the sample structural properties seem to have a greater effect than the storage environment on the dissolution properties. 相似文献
49.
Hiromi Yoshida Yuka Tomiyama Masayuki Saiki Yoshiyuki Mizushina 《Journal of the American Oil Chemists' Society》2007,84(11):1031-1038
The positional distribution of fatty acids (FA) of triacylglycerols (TAG) and major phospholipids (PL) prepared from four
cultivars of peas (Pisum sativum L.) were investigated as well as their tocopherol contents. The lipids extracted from these peas were separated by thin-layer
chromatography (TLC) into seven fractions. The major lipid components were PL (52.2–61.3%) and TAG (31.2–40.3%), while the
other components were also present in minor proportions (5.6–9.2%). γ-Tocopherol was present in the highest concentration,
and α- and δ-tocopherols were very small amounts. The main PL components isolated from the four cultivars were phosphatidylcholine
(42.3–49.2%), followed by phosphatidylinositol (23.3–25.2%) and then phosphatidylethanolamine (17.7–20.5%). Small but significant
differences (P < 0.05) in FA distribution existed when different pea cultivars were determined. However, the principal characteristics of
the FA distribution in the TAG and the three PL were evident among the four cultivars; unsaturated FA were predominantly located
in the sn-2 position, and saturated FA primary occupied the sn-1 or sn-3 position in the oils of the peas. These results suggest that the regional distribution of tocopherols and fatty acids in
peas is not dependent on the climatic conditions and the soil characteristics of the cultivation areas during the growing
season. 相似文献
50.
Hydrogen and carbon dioxide adsorption with tetra‐n‐butyl ammonium semi‐clathrate hydrates for gas separations 下载免费PDF全文
Hiroyuki Komatsu Masaki Ota Yoshiyuki Sato Masaru Watanabe Richard L. Smith Jr. 《American Institute of Chemical Engineers》2015,61(3):992-1003
Gas adsorption rates of H2, CO2, and H2‐CO2 gas mixture (H2/CO2 = 3.4) with tetra‐n‐butyl ammonium salt (bromide, chloride, and fluoride) semi‐clathrate hydrate particles were measured at 269 K to assess their properties for gas separation. Equilibrium gas occupancies in the S‐cages of the particles were in order of (high to low) for hexagonal structure‐I, tetragonal structure‐I, and superlattice of cubic structure‐I structures with the maximum fractional occupancy by CO2 being about 40%. The CO2 diffusion rate depended on the anion size of the salt, which is attributed to distortion of the S‐cage that is close to the molecular size of CO2. Simulations of semi‐clathrate hydrate particles with theory showed that H2/CO2 selectivities could be as high as 36 (3.0 mol% TBAF) and that selectivities for an ideal membrane (3.3 mol% TBAF) could be >100 (269 K, 0.3–4.5 MPa). Semi‐clathrate hydrates have wide application as separation media for gas mixtures. © 2014 American Institute of Chemical Engineers AIChE J, 61: 992–1003, 2015 相似文献