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排序方式: 共有3691条查询结果,搜索用时 15 毫秒
91.
Jun Okamoto Jr. Valdir Grassi Jr. Paulo Faria Santos Amaral Benedito Geraldo Miglio Pinto Daniel Pipa Gustavo Pinto Pires Marcus Vinicius Maciel Martins 《Journal of Intelligent and Robotic Systems》2012,66(1-2):23-35
Inspection for corrosion of gas storage spheres at the welding seam lines must be done periodically. Until now this inspection is being done manually and has a high cost associated to it and a high risk of inspection personel injuries. The Brazilian Petroleum Company, Petrobras, is seeking cost reduction and personel safety by the use of autonomous robot technology. This paper presents the development of a robot capable of autonomously follow a welding line and transporting corrosion measurement sensors. The robot uses a pair of sensors each composed of a laser source and a video camera that allows the estimation of the center of the welding line. The mechanical robot uses four magnetic wheels to adhere to the sphere’s surface and was constructed in a way that always three wheels are in contact with the sphere’s metallic surface which guarantees enough magnetic atraction to hold the robot in the sphere’s surface all the time. Additionally, an independently actuated table for attaching the corrosion inspection sensors was included for small position corrections. Tests were conducted at the laboratory and in a real sphere showing the validity of the proposed approach and implementation. 相似文献
92.
Surface degradation of polyamide nanocomposites caused by partial discharges using IEC (b) electrodes 总被引:1,自引:0,他引:1
Kozako M. Fuse N. Ohki Y. Okamoto T. Tanaka T. 《Dielectrics and Electrical Insulation, IEEE Transactions on》2004,11(5):833-839
Partial discharge (PD) degradation of polyamide both without nanoscale fillers (nanofillers) and with 2,4 and 5 wt% additions of nanofillers was investigated. Such materials were subjected to PDs using the IEC (b) electrodes for evaluation. Comparisons were made as to the surface roughness observed by scanning electron microscopy and atomic force microscopy. It was found that the change in the surface roughness is far smaller in specimens with nanofillers than those without nanofillers, and that the 2 wt% addition is sufficient for improvement of the surface roughness. Furthermore, it was elucidated that the difference of surface roughness of the degraded area due to PDs among the specimens originates from the difference in their crystalline structures. These results indicate that polyamide nanocomposite is more resistance to PDs than polyamide without nanofillers. 相似文献
93.
Y Kawano Y Takaue P Law T Watanabe T Abe Y Okamoto A Makimoto J Sato R Nakagawa T Kajiume A Hirao A Watanabe Y Kuroda 《Canadian Metallurgical Quarterly》1998,22(10):1011-1017
The quality of population-based cancer registries has been measured by the indices of the proportion of total incident cases (DCO%) registered by death certificate only (DCO), and the ratio of incidence to mortality (I/D ratio). Recently it has been recommended that DCO% should be used as an index for the reliability of diagnosing cancers and that the proportion of cases first notified via death certificate (DCN, DCN%) be used as an index for the completeness of registration. Parkin introduced a method to estimate the registration rate, the estimated proportion of the "true incidence" that are registered in population-based registries. We recommend a modified method for estimating the registration rate for cancer registries where DCN% is relatively high, as it is in Japan, as Parkin's method may overestimate the registration rate. The method is as follows: the registration rate = (1-DCN% x 1/D ratio)/(1-DCN%). The registration rates at the Osaka Cancer Registry between 1966 and 1992 were estimated using our method. During this period, the yearly registration rate was 74.6-78.4% for males and 69.1-73.3% for females. When the cancer cases were looked at according to site, the yearly registration rate was 74.2-81.6% for stomach cancer, 81.2-89.3% for lung cancer, and 71.3-76.9% for uterine cancer. These results show that the registration rate is high for cancers that have an unfavorable prognosis and low for cancers that have a favorable prognosis. We recommend that all cancer registries in Japan calculate the completeness of registration by utilizing DCN defined as the sum of DCO plus cases not reported as cancer but with supportive clinical information of such obtained through survey of the registry for DCN. 相似文献
94.
Tomohiro Fujii Jun Nishikawa Soichiro Fukuda Naoto Kubota Junzo Nojima Koichi Fujisawa Ryo Ogawa Atsushi Goto Koichi Hamabe Shinichi Hashimoto Aung Phyo Wai Hisashi Iizasa Hironori Yoshiyama Kohei Sakai Yutaka Suehiro Takahiro Yamasaki Taro Takami 《International journal of molecular sciences》2022,23(18)
DNA methylation of both viral and host DNA is one of the major mechanisms involved in the development of Epstein–Barr virus-associated gastric carcinoma (EBVaGC); thus, epigenetic treatment using demethylating agents would seem to be promising. We have verified the effect of , which was discovered by screening for demethylating agents. MC180295 inhibited cell growth of the EBVaGC cell lines YCCEL1 and SNU719 in a dose-dependent manner. In a cell cycle analysis, growth arrest and apoptosis were observed in both YCCEL1 and SNU719 cells treated with MC180295. MKN28 cells infected with EBV were sensitive to MC180295 and showed more significant inhibition of cell growth compared to controls without EBV infection. Serial analysis of gene expression analysis showed the expression of genes belonging to the role of BRCA1 in DNA damage response and cell cycle control chromosomal replication to be significantly reduced after MC180295 treatment. We confirmed with quantitative PCR that the expression levels of BRCA2, FANCM, RAD51, TOP2A, and CDC45 were significantly decreased by MC180295. LMP1 and BZLF1 are EBV genes with expression that is epigenetically regulated, and MC180295 could up-regulate their expression. In conclusion, MC180295 inhibited the growth of EBVaGC cells by suppressing DNA repair and the cell cycle. MC180295相似文献
95.
Kosuke Oiwa Rikito Okamoto Shizuka Bando Akio Nozawa 《Artificial Life and Robotics》2018,23(2):218-224
The amount of mental work using information equipment has been increasing because of a rapid growth of an information society. Accumulation of short-term mental work can cause various stresses and a disturbance of circadian rhythm and lead to fatigue, anxiety, and distraction. Estimation and understanding the physiopsychological states is desired for decreasing or controlling stresses to maintain health. There have been several investigations on the assessment of short-term physiopsychological states using infrared thermography. However, the method has been used rarely for assessing long-term physiopsychological states. In the present study, extraction of independent components related to long-term physiological signals is attempted by applying independent component analysis to facial thermal images obtained over 6 months (July–December). Furthermore, multiple regression analysis is attempted to create psychological model by facial thermal images. As the result, extracted independent components are shown to represent the strong features in nasal, mouth, cheek, eyebrow, and forehead regions. Attempting multiple regression analysis, features in nasal and mouth regions contributed to depression or dejection mood, features in cheek, eyebrow and forehead regions contributed to fatigue and features in tip of nasal, eyebrow and mouth regions contributed to state anxiety. 相似文献
96.
The viscoelastic properties of soybean curd (tofu) as affected by soymilk concentration and type of coagulant 总被引:1,自引:0,他引:1
Yongqiang Cheng Naoto Shimizu & Toshinori Kimura 《International Journal of Food Science & Technology》2005,40(4):385-390
The viscoelastic properties of different types of tofu were investigated. Soymilk concentrations were 5, 6, 7, 8 and 9%. Coagulants used were 30 mm CaSO4 or 30 mm glucono‐delta‐lactone (GDL). As the concentration of soymilk was increased viscosity and handling difficulties increased. A high concentration of soymilk in tofu gave a high break stress and produced hard tofu. The four‐element Burgers model fitted the creep behaviour and both viscous and elastic parameters could be acquired from model analysis, reflecting changes in elasticity and viscosity of tofu. The constant viscous parameter in the model increased with increasing soymilk concentration. The viscous parameters of viscoelastic materials like tofu gel, obtained from small deformation tests, seemed to correlate, to some extent, with the break stress obtained from large deformation tests. For hard tofu production increasing the soymilk concentration within a certain range and the partial replacement of calcium sulphate coagulant by GDL could be effective options. 相似文献
97.
Comparison of pool boiling CHF of a polished copper block and carbon steel block on a declined slope
Kai Wang Nejdet Erkan Laishun Wang Koji Okamoto 《Journal of Nuclear Science and Technology》2018,55(9):1065-1078
This study conducts a critical heat flux (CHF) experiment on a carbon steel block, and the block is positioned on slope that is declined at angles of 5° and 10°. The results of the carbon steel block experiment were then analyzed and compared with the results obtained from a copper block experiment that had been conducted previously at the same test facility. The comparison showed that several different types of phenomena had occurred, and the carbon steel block CHF at both 5° and 10° was much lower than that of the copper block. Detailed images of the heating surface of each material were acquired by a high-speed camera under different heat fluxes and analyzed. The carbon steel block surface generates more bubbles compared to the copper block under the same heat flux, which indicates that the carbon steel block should have a large number of nucleation sites. This causes a higher CHF. Finally, several existing theories on CHF mechanisms were also analyzed in an attempt to explain the difference of copper and carbon steel. It seemed that the contact angle alone was not sufficient to explain the large CHF decrease in the carbon steel block. 相似文献
98.
Ichiro Hirosawa Tetsuo Honma Kazuo Kato Naoto Kijima Yasuo Shimomura 《Journal of the Society for Information Display》2004,12(3):269-273
Abstract— We studied the influence of annealing in air on doped europium in BaMgAl10O17 by performing x‐ray absorption fine‐structure measurements. We determined the oxidation of doped divalent europium by annealing in air at over 500°C. The interatomic distance between the europium and the surrounding oxygen atoms was compressed by oxidation. It also appears that the oxidation process of europium is determined by the diffusion of oxygen into BaMgAl10O17. 相似文献
99.
Hiroaki Okamoto 《Journal of Phase Equilibria and Diffusion》2013,34(3):251-263
Recent literature on Cs-In, Cs-K, Cs-Rb, Eu-In, Ho-Mn, K-Rb, Li-Mg, Mg-Nd, Mg-Zn, Mn-Sm, O-Sb, and Si-Sr phase diagrams is reviewed in this article in order to update the 1990 compilation Binary Alloy Phase Diagrams, 2nd edition, by T.B. Massalski, et al. For some systems reaction tables and crystal structure data have been included, as well. Diagrams have been checked for consistency with rules for phase diagram construction and modified when necessary. In addition, diagrams needing more work have been identified. 相似文献
100.
Scale free graphs have attracted attention by their non-uniform structure that can be used as a model for various social and physical networks. In this paper, we propose a natural and simple random model for generating scale free interval graphs. The model generates a set of intervals randomly under a certain distribution, which defines a random interval graph. The main advantage of the model is its simpleness. The structure/properties of generated graphs are analyzable by relatively simple probabilistic and/or combinatorial arguments, which is different from many other models. Based on such arguments, we show for our random interval graph that its degree distribution follows a power law, and that it has a large average clustering coefficient. 相似文献