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971.
Masahiko Yamada Shoichiro Fukusako Tsuyoshi Kawanami Masanori Kurita Cheol Oh 《亚洲传热研究》1998,27(1):43-56
Experiments were carried out to determine the effect of flow separation on freezing heat transfer characteristics along a horizontal cooled flat plate immersed within a rectangular duct. The flow separation was induced by a vertically situated thin plate placed against the flow at the leading edge of a uniformly cooled plate. The degree of flow separation was altered by employing vertical plates of various heights. The Reynolds number and the cooling temperature ratio ranged from 5.6 x 102 to 8.4 x 104 and from 3.0 to 10.0, respectively. The measurements showed that the flow separation exerts a marked influence on the local ice formation characteristics. Two kinds of ice formation of convex and concave profiles were observed to occur as a function of the Reynolds number, as well as of the cooling temperature ratio. © 1998 Scripta Technica. Heat Trans Jpn Res, 27(1): 43–56, 1998 相似文献
972.
Tsuyoshi Nishi Takumi Manako Katsuya Ohnuma Hiromichi Ohta Sohei Sukenaga Hiroyuki Shibata 《Journal of Nuclear Science and Technology》2019,56(8):710-715
Borosilicate glasses are candidate materials for the immobilization of high-level radioactive waste. The values of thermal conductivity of different borosilicate melts are thus indispensable information when optimizing the temperature distribution in a glass melting furnace. In this study, the thermal effusivity of Na2O–B2O3–SiO2 melts was measured using a front heating–front detection laser-flash method. The thermal conductivity, which can be obtained by combining the measured thermal effusivity with the specific heat capacity and density, was calculated using the least-squares method; the values for the Na2O–B2O3–SiO2 melts either slightly decreased linearly with increasing temperature or remained almost constant over the investigated temperature range. The values of thermal conductivity of the Na2O–B2O3–SiO2 melts were higher than those of B2O3–SiO2 melts and lower than those of CaO–B2O3–SiO2 melts. Furthermore, the thermal conductivity of the Na2O–B2O3–SiO2 melts was compared with those of the B2O3–SiO2 and CaO–B2O3–SiO2 samples. 相似文献
973.
Takahiro Ishikawa Hiroyuki Iso Masakazu Oikawa Teruaki Konishi Hisashi Kitamura Yuichi Higuchi Noriyoshi Suya Tsuyoshi Hamano Hitoshi Imaseki 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2009,267(12-13):2032-2035
Microbeam scanning-PIXE (micro-PIXE) analysis is a useful method for obtaining information of multi-elemental distribution in samples by two-dimensional images of sample surfaces such as mammalian cells, tissues, and other environmental monitoring species. In addition to elemental distribution information, quantitative analysis is in demand for further investigations of environmental and biomedical studies concerning heavy metals accumulated in terms of cells and sub-cellular organelles. To make quantitative analysis possible, a real-time beam monitoring system that gives a precise number of ions, and an output independent from a sample that enables one to keep a beam resolution of micrometer size is required. In this paper, we report on the development of beam current monitoring. The beam current was monitored using a ceramic channel electron multiplier (CEM) to detect secondary electrons induced from a 50 nm thick carbon film (10 μg/cm2). This carbon film was attached to a sample holder, which was set at the targeted sample position. The output value of the CEM was proportional to the Faraday cup installed just after the sample position. The beam resolution was measured using off-axis STIM by scanning a copper grid, and was estimated at 1.79 and 1.72 μm for the horizontal and vertical directions, respectively, sufficient for routine micro-PIXE analysis. 相似文献
974.
Araki Wakiuchi Shogo Takasuka Shigehito Asano Ryo Hashizume Aniruddha Nag Miho Hatanaka Tomoyuki Miyao Yuya Ohnishi Takamitsu Matsubara Tsuyoshi Ando Tetsunori Sugawara Mikiya Fujii Hiroharu Ajiro 《大分子材料与工程》2023,308(6):2200626
It is important to match the feeding ratio of comonomers to the composition ratio in the resulting copolymers as closely as possible in industrial production, where the goal is often to produce more a homogeneous composition in copolymers. In this study, a flow copolymerization system with a conventionally initiated free radical method, together with randomly selected polymerization conditions is investigated. It is succeeded in achieving a closer match between the composition ratio and feeding ratio than previously reported in the copolymerization of styrene with methyl methacrylate and of glycidyl methacrylate with methyl methacrylate, which will widen the range of applications, by precisely controlling the mixing and heating in a flow polymerization apparatus. This is confirmed by the fact that the estimated values of reactivity ratios, r1 and r2, which are used in the reaction kinetics of copolymerization, are close to 1. 相似文献
975.
This paper proposes methodology and gate drive circuit that can immediately detect short-circuit (SC) of multiparalleled SiC-MOSFETs even under current imbalance condition. Proposed method detects SC current using an integration circuit that can sense di/dt. The detection level of SC current can be adjusted to a desired value regardless of the number of SiC-MOSFETs connected in parallel. The effectiveness of the proposed approach was experimentally validated for four-paralleled SiC-MOSFETs under extreme current imbalance in SC condition. SC was detected within 0.5 μs and all SiC-MOSFETs were protected without destruction at most 2.2 μs after the onset of SC, for all types of SC 1, 2, and 3. 相似文献
976.
Kenji Saito Tsuyoshi Ito Takashi Kuribayashi Kazumi Mochida Teruo Nakakuki Masaru Shibata Masayoshi Sugawara 《Starch - St?rke》2001,53(9):424-430
Resistant starch content of high‐amylose corn starch (HAS) was doubled by heat‐moisture treatment. Resistant starch content of HAS and heat‐moisture treated high‐amylose corn starch (HMT‐HAS) were 31.8 and 67.3%, respectively, as determined by enzymatic‐gravimetric method. Effects of the two types of high‐amylose corn starches, HAS and HMT‐HAS, on starch fermentation, microflora, pH, short chain fatty acid (SCFA) content and β‐glucuronidase activity in the cecal content have been investigated. Rats were given ordinary corn starch (OCS; control), HAS or HMT‐HAS at 10% level for 10 13 days. The cecal and colorectal content s weights were larger in HAS and HMT‐HAS groups than in the OCS group. The cecal content s weight did not differ between HAS and HMT‐HAS groups, while the colorectal content s weight was higher in the HMT‐HAS group than in the HAS group. The upper and lower small intestinal and cecal starch contents were significantly higher in the HAS and HMT‐HAS groups than in the OCS group, whereas there were no differences between colorectal starch content in group OCS and HAS. Starch excretion in feces was significantly higher in groups HAS and HMT‐HAS than in group OCS, the increase in the HMT‐HAS group was especially remarkable. The composition of the cecal microflora was not effected by the diet. β‐Glucuronidase activities in rats fed HAS or HMT‐HAS decreased. SCFA concentration was higher in groups HAS and HMT‐HAS than in group OCS, and the cecal pH was lower in groups HAS and HMT‐HAS than in group OCS. 相似文献
977.
978.
979.