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排序方式: 共有583条查询结果,搜索用时 15 毫秒
141.
Ravikumar Ramakrishnaiah Abdulaziz Abdullah Alkheraif Darshan Devang Divakar Khuloud Fahad Alghamdi Jukka Pekka Matinlinna Christie Ying Kei Lung Sunil Cherian Pekka Kalevi Vallittu 《SILICON》2018,10(6):2391-2397
This in vitro study was aimed to evaluate the possible changes in wettability of an etched glass ceramic surface to silane primers, adhesive resin and resin cement when the surface had been neutralized by a special neutralizing agent after etching. Rectangular shaped specimens were cut from the CAD blocks of an e-max lithium disilicate glass ceramic, cut specimens were sequentially polished and ultrasonically cleaned. All the specimens were etched for 20 s with 5% hydrofluoric acid and ultrasonically cleaned. Specimens were randomly assigned to one control group (without neutralization) and one treatment group (with neutralization) having 20 specimens each. The specimens of each group were further divided into two subgroups having 10 specimens each and tested to determine the effect of neutralizing agent on wettability of experimental and commercial silanes. Each subgroup specimen was tested for wettability to adhesive resin and commercial resin cement. Data were analyzed using two-way ANOVA. Neutralizing the ceramic surface did not show a significant effect on wettability to the silanes and the resin based materials, but the experimental silane showed better wettability than the commercial silane. The adhesive resin had statistically significant lower contact angle (high wettability) values than the commercial resin cement. The results of the current study suggested that the neutralizing agent did not have an impact on the wettability of the etched ceramic. However, there were differences in wetting properties of the silane primers, and adhesive resin versus resin composite luting cements. 相似文献
142.
Hiroyuki Nakagomi Yoshihiro Fuse Hidehiko Hosaka Hironaga Miyamoto Takashi Nakamura Akira Yoneyama Masashi Yokotsuka Akiya Kamimura Hiromi Watanabe Tsutomu Tanzawa Shinji Kotani 《Electrical Engineering in Japan》2019,209(3-4):14-25
In order to enable an autonomous mobile robot to travel over rough terrain, it necessitates the capability to detect self‐position accurately even when the odometry errors are increased in traveling. The conventional method can keep high speed and precise localization using iterative closest point algorithms or feature matching techniques. However, effects of steep changes of a mobile robot position are not considered when it travels over rough terrain. In this article, we propose the method for efficient real‐time 6D pose tracking using a rotating 2D laser scanner in traveling over rough terrain. For adaptation to steep changes of the position, weighted point clouds are generated based on the angular and the linear velocity measured by sensors mounted on the robot. And the position and posture of the robot are sequentially optimized by the scan matching in increments of 10 scans. In indoor experiments, we evaluated accuracy of our method when the robot passes on rugged floor. As a result, our method was performed with less than 0.078 m RMS positional error in real time. 相似文献
143.
The prototype fast breeder reactor "MONJU" has an EVSS (ex-vessel fuel storage system) which consists mainly of an EVST (ex-vessel fuel storage tank) and an EVST sodium cooling system. EVST sodium cooling system consists of three independent loops. During the normal operation, the primary sodium in the EVST is circulated by natural convection and the secondary circulation in the EVST sodium cooling system is powered by electromagnetic pumps. When an SBO (station blackout) occurs, all the pumps and blowers are tripped. Therefore, it was necessary to evaluate the cooling ability by the natural circulation of sodium in the EVST sodium cooling system and air through the air cooler during the SBO. In this study, an analysis and evaluation of the plant dynamics for the spent fuel and the EVSS structural integrity during an SBO were performed. When the number of cooling loops was not changed and natural circulation occurred in only two loops, the sodium temperature in the EVST increased to approximately 450 ~C. However, the structural integrity of the EVSS was maintained. The analytical results, therefore, help clarify the number of necessary cooling loops for efficient decay heat removal and sodium temperature behavior in an SBO. 相似文献
144.
Candida kefyr is a common yeast species that can be found in fermented milk and cheeses. As a first step to developing a gene transfer system for C. kefyr, the orotidine‐5′‐phosphate decarboxylase (URA3) gene was cloned, using degenerate PCR and genome walking. The uninterrupted open reading frame of the C. kefyr URA3 gene spans 801 bp, corresponding to 267 amino acid residues. The functionality of the gene was confirmed by complementation of ura3 auxotrophs of C. albicans and Saccharomyces cerevisiae. Phylogenetic analysis of the deduced amino acid sequence indicated that it shares a high degree of homology with other Candida URA3 homologues. The GenBank Accession No. of the C. kefyr URA3 gene is FJ914763. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
145.
Makoto Saiki Thi Phuong Mai Nguyen Junko Shindo Kei Nishida 《Nutrient Cycling in Agroecosystems》2020,117(3):411-411
The article Nitrogen balance in paddy fields under flowing-irrigation condition, written by Makoto Saiki, Thi Phuong Mai Nguyen, Junko Shindo, Kei Nishida, was originally published Online First... 相似文献
146.
C. C. Kei Y. S. Yu J. Racek D. Vokoun P. Šittner 《Journal of Materials Engineering and Performance》2014,23(7):2641-2649
Atomic layer deposition is introduced as a method suitable for preparation of Al2O3 layers on the surface of NiTi medical devices such as stents because of the excellent thickness control and conformal protective coating on complex structures. The corrosion properties of NiTi plates with Al2O3 coatings of various thicknesses in an environment similar to that occurring in the human body were studied using open circuit potential, potentiostatic electrochemical impedance spectroscopy, and cyclic polarization tests. It shows that the layer thickness plays a key role in the inhibition of corrosion. The thinner layers are more diffuse and make it easier for anodic reaction of passive NiTi with protective TiO2 underneath of Al2O3, while the thicker layers have the barrier effect with local pores initiating pitting corrosion. The results of our electrochemical experiments consistently show that corrosion properties of thick Al2O3 coatings on NiTi plate are inferior compared to the thin layers. 相似文献
147.
The application of thermal microscopes to the measurement of local thermal properties has drawn considerable scientific interest. We report on the application of a thermal microscope to the measurement of thermal effusivity for films comprising alumina deposited on a substrate, which were fabricated by an electrophoretic deposition method. The measured data was analyzed to consider the undulations on the sample surface The thermal effusivity of these samples was approximately 1×103 Js?0.5m?2K?1; this value is smaller than that for dense alumina because the alumina grain makes contact with a point. © 2008 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20227 相似文献
148.
Satoru Fujishige Takumi Hayashi Kei Yamashita Uwe Zimmermann 《Optimization and Engineering》2009,10(2):193-205
Although linear programming problems can be solved in polynomial time by the ellipsoid method and interior-point algorithms,
there still remains a long-standing open problem of devising a strongly polynomial algorithm for linear programming (or of
disproving the existence of such an algorithm). The present work is motivated by an attempt toward solving this problem.
Linear programming problems can be formulated in terms of a zonotope, a kind of greedy polyhedron, on which linear optimization
is made easily. We propose a method, called the LP-Newton method, for linear programming that is based on the zonotope formulation
and the minimum-norm-point algorithm of Philip Wolfe. The LP-Newton method is a finite algorithm even for real-number input
data with exact arithmetic computations. We show some preliminary computational results to examine the behavior of the LP-Newton
method.
Major part of this paper was presented as a plenary talk with the same title at ICOTA7 (December 12–15, 2007, Kobe, Japan)
by the first author. The fourth author’s research was carried out while visiting RIMS in August 2007. 相似文献
149.
Md. Sirajul Islam Taikan Oki Shinjiro Kanae Naota Hanasaki Yasushi Agata Kei Yoshimura 《Water Resources Management》2007,21(1):19-33
A 0.5-degree grid-based assessment of the scarcity of global water resources including virtual water trading has been made.
The three components of water availability considered for each grid were local runoff, routed flow from upstream and virtual
water trading. Several assumptions were postulated to convert country-base estimations of virtual water trading to grid values.
The results show that unequal spatial distribution of global water resources had been considerably neutralized by virtual
water trading. A large proportion of people in the Middle-East, North-Africa and Sub-Sahara region are able to relieve their
water stress through virtual water import. The paper also reports two hypothetical scenarios with extremes of natural flow
availability based on the presence and absence of routed upstream flow. 相似文献
150.