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111.
Kazuya Yamaji Hiroki Koike Yohei Kamiyama Kazuki Kirimura Shinya Kosaka 《Journal of Nuclear Science and Technology》2018,55(7):756-780
In order to achieve highly accurate resonance calculations with short computation time , a new ultra-fine-group resonance calculation method is developed. The ultra-fine-group method has a limitation in practical design applications of large and complicated geometries in fuel assembly level due to its long computation time. Therefore, we developed an enhanced one-dimensional (1D) cylindrical pin-cell model to achieve both high calculation accuracy and short computation time. In the enhanced 1D cylindrical pin-cell modeling, moderator radius is adjusted to preserve each fuel pellet's Dancoff factor obtained in the exact 2D fuel lattice arrangement. We call this model the ‘equivalent Dancoff-factor’ cell model. This model can accurately consider heterogeneity effects in PWR fuel assemblies and can represent effective cross sections obtained by the ultra-fine-group calculations in the complicated 2D square lattice arrangements. The present method is implemented with Mitsubishi Heavy Industries, Ltd. lattice physics code GALAXY. From the comparisons of neutron multiplication factors and pin power distributions between GALAXY and a continuous-energy Monte Carlo code, applicability of the present method to lattice physics calculations is confirmed. Application of GALAXY with the present method achieves high accuracy with short computation time in normal operations and accident conditions including low moderator density conditions. 相似文献
112.
New process for catalyst-free biodiesel production using subcritical acetic acid and supercritical methanol 总被引:1,自引:0,他引:1
The production of glycerol as a by-product is unavoidable in the current conventional biodiesel manufacturing processes. Since biodiesel production is expected to increase in the near future, effective utilization of glycerol will become an issue of interest. In this study, therefore, a process consisting of subcritical acetic acid treatment to convert rapeseed oil to fatty acids and triacetin followed by conversion of the obtained fatty acids to their fatty acid methyl esters in supercritical methanol treatment was investigated. The obtained results clearly revealed that this two-step reaction could proceed effectively at a high reaction rate, and that fatty acid methyl esters and triacetin could be obtained under milder reaction condition than the one-step process utilizing supercritical methyl acetate and supercritical methanol. 相似文献
113.
T Ishiyama K Watanabe K Fukuchi K Yajima M Koike S Tomoyasu N Tsuruoka 《Canadian Metallurgical Quarterly》1993,37(2-3):139-144
CD5 antigen is present on all normal alpha beta T cells and some B cells. Human NK cells do not usually express CD5 antigen, but we found a subset of CD5LOW+ (low density of CD5) NK cells in some patients with pulmonary tuberculosis. Unlike CD5-NK cells, most CD5LOW+NK cells had HLA-DR. We observed few CD5LOW+NK cells in the normal controls and some in the large granular lymphocyte (LGL) population purified by Percoll density centrifugation. Sorted CD5LOW+NK populations were LGL. The CD5LOW+NK cells had high lytic activity on K562 cells in a 4-h 51chromium release assay. Our results indicate that there is a previously unidentified subset of NK cells. 相似文献
114.
Yohei Takada Masayuki Kishimoto Nobuyuki Kawamura Norihisa Komoda Hiroaki Oiso Takahiro Yamasaki Tadao Masanari 《电信纪事》2003,58(3-4):507-530
In an exhibition hall, it is important to provide visitors with information about the exhibit. In this paper, an information service system using Bluetooth in an exhibition hall is proposed. This system automatically provides an explanation of the nearby exhibit to visitors based on the estimated location information. This system can also act as a guide through the exhibit, leading the recommended tour. Moreover, several management support functions using the visitors’ location log are proposed. To keep continuous connection between access points and a visitor’s mobile device for smooth browsing operation, a pre-download method and a special handover are proposed. The pre-download method decides the information to be downloaded based on the visitor browse. The download order is determined based on the prediction of the visitor movement. Through the simulation in various room-layouts, access point layouts and walking routes, the effectiveness of the proposed methods are shown. The prototype of the information service system that installs the proposed methods has been developed. 相似文献
115.
Ichiro Sasagawa Mikio Ishiyama Hiroyuki Yokosuka Masato Mikami 《Frontiers of Materials Science in China》2008,2(2):134-142
The fine structure of collar enamel and the cells constituting the enamel organ during amelogenesis in Lepisosteus oculatus was observed by light, scanning electron and transmission electron microscopy. In the enamel, slender crystals were arranged
perpendicular to the surface and the stripes that were parallel to the surface were observed, suggesting that the enamel in
Lepisosteus shares common morphological features with that in sarcopterygian fish and amphibians. Ameloblasts containing developed Golgi
apparatus, rough endoplasmic reticulum (rER) and secretory granules were found in the secretory stage. In the maturation stage,
a ruffled border was not seen at the distal end of the ameloblasts, while many mitochondria and lysosome-like granules were
obvious in the distal cytoplasm. The enamel organ consisted of the outer dental epithelial cells, stratum reticulum cells
and ameloblasts, but there was no stratum intermedium. It is likely that the ameloblasts have less absorptive function in
comparison with the inner dental epithelial cells facing cap enameloid. 相似文献
116.
A new scanning mechanism for changing long optical paths is proposed. This mechanism consists of corner reflectors arranged equally upon a disk and an outer mirror. Rotating the 120-mm disk causes a long-optical-path change in each reflector with a near linearity of more than 40 mm. An optical coherence tomography system is described that confirms the usefulness of the proposed mechanism. Its operating characteristics and accuracy are evaluated by analysis and experiment. The deviation of the optical-path change is less than 1.52% at a reflector rotation angle of +/-10 degrees. A high-speed lock-in amplifier is utilized for fundamental measurements of glass samples. 相似文献
117.
This paper presents an analytical method to predict contact stiffness and friction damping in bolted connections. Despite its importance in machine design, analytical prediction of the contact parameters has not been realized because of difficulty in time-history nonlinear analysis of sticking/sliding contact. In this study, a torsional contact model around a connecting bolt is developed. Linear phenomena are extracted and solved by FEM analysis, and then linear combination of the FEM results is calculated iteratively to search sticking/sliding zones in torque equilibrium. Proposed model is experimentally validated, and it will lead to fully analytical modelling of practical machines. 相似文献
118.
119.
Given a set of rectangles and a rectangular container with a fixed width, called a strip, the two-dimensional strip packing problem (2SP) requires all the given rectangles to be placed orthogonally without overlap within the strip so as to minimize the height of the strip. 2SP and its variants have many applications in steel and textile industries, including an indirect application in scheduling problems. However, 2SP is known to be NP-hard. 相似文献
120.
Takayasu Ideta Yohei Shirakami Tsuneyuki Miyazaki Takahiro Kochi Hiroyasu Sakai Hisataka Moriwaki Masahito Shimizu 《International journal of molecular sciences》2015,16(12):29207-29218
Non-alcoholic fatty liver disease (NAFLD), which is strongly associated with metabolic syndrome, is increasingly a major cause of hepatic disorder. Dipeptidyl peptidase (DPP)-4 inhibitors, anti-diabetic agents, are expected to be effective for the treatment of NAFLD. In the present study, we established a novel NAFLD model mouse using monosodium glutamate (MSG) and a high-fat diet (HFD) and investigated the effects of a DPP-4 inhibitor, teneligliptin, on the progression of NAFLD. Male MSG/HFD-treated mice were divided into two groups, one of which received teneligliptin in drinking water. Administration of MSG and HFD caused mice to develop severe fatty changes in the liver, but teneligliptin treatment improved hepatic steatosis and inflammation, as evaluated by the NAFLD activity score. Serum alanine aminotransferase and intrahepatic triglyceride levels were significantly decreased in teneligliptin-treated mice (p < 0.05). Hepatic mRNA levels of the genes involved in de novo lipogenesis were significantly downregulated by teneligliptin (p < 0.05). Moreover, teneligliptin increased hepatic expression levels of phosphorylated AMP-activated protein kinase (AMPK) protein. These findings suggest that teneligliptin attenuates lipogenesis in the liver by activating AMPK and downregulating the expression of genes involved in lipogenesis. DPP-4 inhibitors may be effective for the treatment of NAFLD and may be able to prevent its progression to non-alcoholic steatohepatitis. 相似文献