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51.
52.
Heat-moisture treatment of high-amylose corn starch increases dietary fiber content and lowers plasma cholesterol in ovariectomized rats 总被引:1,自引:0,他引:1
ABSTRACT: The effect of dietary high-amylose corn starch (HACS) of varying dietary fiber (DF) content on plasma cholesterol was examined in ovariectomized (OVX) rats. Gelatinized normal corn starch (G-CS) was used as a reference. OVX rats were fed a fiber-free purified diet containing G-CS, HACS, gelatinized high-amylose corn starch (G-HACS), or heat-moisture treated HACS (HM-HACS) at 400 g starch/kg diet for 21 d. The DF content of G-CS, HACS, G-HACS, and HM-HACS measured by the AOAC method was 0.1, 19.3, 2.4, and 64.5 g/100 g, respectively. The dry weight of cecal contents, cecal wall weight, the amount of short chain fatty acids in cecal contents, the amount of bile acids in small intestinal contents, and fecal excretion of neutral sterols increased logarithmically with increasing DF, while total plasma cholesterol concentration decreased. On the other hand, hepatic CYP7A1 activity, fecal dry weight, and fecal excretion of bile acids increased linearly with increasing DF, while body weight gain decreased. The hypocholesterolemic effect of HACS in OVX-rats appeared to be more effective by heat-moisture treatment. 相似文献
53.
Crack-Healing Behavior of Si3 N4 /SiC Ceramics under Cyclic Stress and Resultant Fatigue Strength at the Healing Temperature 总被引:1,自引:0,他引:1
Kotoji Ando Koji Takahashi Shin Nakayama Shinji Saito 《Journal of the American Ceramic Society》2002,85(9):2268-2272
Si3 N4 /SiC composite ceramics were sintered and subjected to three-point bending. A semi-elliptical surface crack of 100 μm surface length was made on each specimen. The crack-healing behavior under cyclic stress of 5 Hz, and resultant cyclic fatigue strengths at healing temperatures of 1100° and 1200°C, were systematically investigated. The main conclusions are as follows: (1) Si3 N4 /SiC composite ceramics have an excellent ability to heal a crack at 1100° and 1200°C. (2) This sample could heal a crack even under cyclic stress at a frequency of 5 Hz. (3) The crack-healed sample exhibited quite high cyclic fatigue strength at each crack-healing temperature, 1100° and 1200°C. 相似文献
54.
Ken Ando Masataka Momoda Takeshi Azumi Sadakichi Kitajima 《Journal of the American Ceramic Society》1987,70(11):309-C
Solubility of NiO in Al2 O3 was determined by electron probe microanalysisy A diffusion couple method was used by coupling an NiO-doped Al2 O3 polycrystal to a pure single crystal of Al2 O3 . The solubility of NiO in Al2 O3 in air was 230 wt ppm (157 at. ppm of cations) and 170 wt ppm (116 at. ppm) at 2073 and 1973 K, respectively. The solubility of NiO in Al2 O3 obtained in this work was compared with our previous work of the solubility of MgO in Al2 o3 . 相似文献
55.
Manabu Tsuburaya 《Polymer》2004,45(3):1027-1032
We found that amorphous polycarbonate (PC) can be crystallized in several minutes by blending poly(ethylene oxide) (PEO). When the blends were annealed in the two-phase region below the upper critical solution temperature, highly interconnected two-phase structure characteristic of the spinodal decomposition was developed and then the crystallization occurred in the PC-rich phase during the spinodal decomposition. As the molecular weight of PEO decreased, the crystallization rate decreased and the crystallizable temperature became narrower in spite of the acceleration of the polymeric segmental motion. These results suggest that the crystallization of the PC is not induced by the acceleration of the polymeric segmental motion, but by the up-hill diffusion of the liquid-liquid phase separation via spinodal decomposition. Owing to the competitive progress of the crystallization and the spinodal decomposition, the melting peak of the PC crystallites shifted to lower temperature with increasing annealing temperature. 相似文献
56.
Manabu Gotoh 《Metals and Materials International》1998,4(4):628-639
Various types of behavior due to plastic instability under uniaxial tension and compression are numerically investigated regarding
sheet materials, plane strain blocks, and cylindrical bars and hollow cylinders. The code GOLDA for analysis of large elastic-plastic
deformation previously developed by the author is used, which is one of quasi-static explicit FEM programs. Both of diffuse
type and localized type of instability are concerned with. The role of vertex-hardening in plastic instability is payed attention,
by using the J2G (J2-Gotoh’s corner theory) as the plasticity constitutive equation, which was proposed previously by the
author and is a kind of vertex-hardening theory. Following results are mainly derived. 1) In plane strain tension, shear-type
strain localization is realized by the use of J2G, but not by the conventional J2F (J2-flow theory). In axisymmetric tension
of a cylindrical solid bar, however, such strain localization would never appear even by J2G, as expected by the experiment.
2) In axisymmetric tension of a hollow cylinder under the condition of no contractlion of its bore (therefore, in almost plane
strain state with no circumferential strain), it is found that shear-type strain localization could occur. This is realized
again by the use of J2G, whereas J2F never allows such strain localization. 3) In compression under the embedded edges condition,
it is found that a sheet with initial aspect ratio of 2:1 (in height:breadth) yields double barreling, whereas a plane strain
block yields double barreling at the initial aspect ratio of 3:1, not at 2:1 though expected from the conventional slip-line
theory. As for a cylindrical solid bar, double barreling appears for the initial aspect ratio of 2:1 but only for higher n-vaiue
(the strain hardening exponent), say n=0.5. 4) As for barreling mode, when thick-walled axisymmetric tubes with the initial
ratio of thickness to inner diameter 1/5 to 1/3 are compressed axially, corresponding to the initial aspect ratios of 3:1,
2:1 and 1:1, triple barreling, double barreling and single barreling appear, respectively. 5) It is found that thin-walled
tubes buckle in a progressive periodic mode with almost stationary compressive load under axial compression. Thus it can be
used as a simplified model for buckling of more complex structures such as the honeycomb. 相似文献
57.
In this study,the permeabilities of Berea and Otway sandstones were measured under different confining pressures,and porosity was investigated through mercury intrusion porosimetry(MIP).The total porosities of the Berea and Otway sandstones were approximately 17.4%and 25%,respectively.Pore size distributions of each sandstone were almost the same,but the pores in the Otway sandstone were slightly narrower.However,the permeability of the Otway sandstone was smaller than that of the Berea sandstone by one order of magnitude.Three-dimensional(3D)void geometry and geometrical properties of the void spaces relevant to flow were compared to obtain the relation between the permeability differences and porosities of the two sandstones.The 3D geometrical analysis using microfocus X-ray computed tomography(CT)was performed,and the pore geometries of both sandstones were compared using the 3D medial axis(3DMA)method.Pore and throat radii,pore coordination number,tortuosity,number of connecting paths,connecting path volume,and other factors were determined using 3DMA.The Otway sandstone was characterized by a small effective throat/pore radius ratio.Based on the fluid flow mechanism,the lower effective throat/pore radius ratio results in a lower permeability induced by the fluid energy loss,which means that the 3D geometrical shape of void spaces affects the permeability value. 相似文献
58.
Manabu TangeTetsuhiko Maeda Akihiro NakanoHiroshi Ito Yoshiaki KawakamiMasao Masuda Toru Takahashi 《International Journal of Hydrogen Energy》2011,36(18):11767-11776
Experimental results for hydrogen storage tanks with metal hydrides used for load leveling of electricity in commercial buildings are described. Variability in electricity demand due to air conditioning of commercial buildings necessitates installation of on-site energy storage. Here, we propose a totalized hydrogen energy utilization system (THEUS) as an on-site energy storage system, present feasibility test results for this system with a metal hydride tank, and discuss the energy efficiency of the system. This system uses a water electrolyzer to store electricity energy via hydrogen at night and uses fuel cells to generate power during the day. The system also utilizes the cold heat of reaction heat during the hydrogen desorption process for air conditioning. The storage tank has a shell-like structure and tube heat exchangers and contains 50 kg of metal hydride. Experimental conditions were specifically designed to regulate the pressure and temperature range. Absorption and desorption of 5,400 NL of hydrogen was successfully attained when the absorption rate was 10 NL/min and desorption rate was 6.9 NL/min. A 24-h cycle experiment emulating hydrogen generation at night and power generation during the day revealed that the system achieved a ratio of recovered thermal energy to the entire reaction heat of the hydrogen storage system of 43.2% without heat loss. 相似文献
59.
A straight-bladed vertical axis wind turbine with a directed guide vane row — Effect of guide vane geometry on the performance — 总被引:2,自引:0,他引:2
Manabu Takao Hideki Kuma Takao Maeda Yasunari Kamada Michiaki Oki Atsushi Minoda 《热科学学报(英文版)》2009,18(1):54-57
The objective of this study is to show the effect of guide vane geometry on the performance. In order to overcome the disadvantages
of vertical axis wind turbine, a straight-bladed vertical axis wind turbine (S-VAWT) with a directed guide vane row has been
proposed and tested by the authors. According to previous studies, it was clarified that the performance of the turbine can
be improved by means of the directed guide vane row. However, the guide vane geometry of S-VAWT has not been optimized so
far. In order to clarify the effect of guide vane geometry, the effects of setting angle and gap between rotor blade and guide
vane on power coefficient and starting characteristic were investigated in the experiments. The experimental study of the
proposed wind turbine was carried out by a wind tunnel. The wind tunnel with a diameter of 1.8m is open jet type. The wind
velocity is 8 m/s in the experiments. The rotor has three straight blades with a profile of NACA0018 and a chord length of
100 mm, a diameter of 0.6 m and a blade height of 0.7 m. The guide vane row consists of 3 arc plates. 相似文献