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51.
Nassim Sahboun Kazuhiro Sawa Yasunori Yamamoto Yuta Watanabe Tomomasa Ito 《Journal of Nuclear Science and Technology》2020,57(9):1111-1120
ABSTRACT In the event of a severe accident, past experiences such as Three Mile Island and Fukushima Daichi have shown that the reactor core of a light-water nuclear reactor, if not properly safeguarded, could go through a meltdown. This will be followed by the formation of a corium, a mix of molten fuel elements, and liquid metals from the Reactor Pressure Vessel (RPV). In the worst-case scenario, a melt through from the RPV can occur and lead to the spreading of the corium, in the form of a molten element’s jet impinging on a flat concrete structure of the Primary Containment Vessel (PCV). To enhance the decommissioning and the safety procedure, scope of the present article is to deepen the understanding of the phenomena involved in the mentioned scenario, mainly jet-instability and molten material spreading. In the present study, experiments were carried out, by using corium simulant materials such as Copper and Tin, to investigate the link between the instability of the gravity-driven molten metal jet and the impinging followed by its spreading over a flat area. 相似文献
52.
Feng B Morita M Imanaka H Imamura K Nakanishi K 《Journal of Bioscience and Bioengineering》2006,102(5):470-473
We identified 22 genes from Aspergillus oryzae that are preferentially expressed in membrane-surface liquid culture (MSLC), among which Ser/Thr protein kinase (aopk1) and phosphatase (aoppt) genes were cloned. We also revealed that aopk1 encodes a protein with an N-terminal sequence 150 amino acid residues longer than that predicted from the registered sequence in GenBank. 相似文献
53.
Volatiles were extracted from rice plants of various growth stages with solid-phase microextraction (SPME) and analyzed by
gas chromatography-mass spectrometry (GC-MS) to identify attractants that cause invasion of the rice leaf bug Trigonotylus caelestialium (Kirkaldy) into paddy fields. The composition of volatile blends produced by rice plants changed with rice development. In
addition, volatile blend compositions differed between the panicles and the stems and leaves. The relative geranyl acetone
content was high in all plant structures analyzed. In volatiles from whole plants in the fourth-leaf stage and panicles in
the full-ripe stage, the relative content of green leaf volatiles (GLVs) was higher than that found in other rice plant structures.
In contrast, relative terpene levels emitted from whole plants in the panicle-formation stage and by panicles and stems and
leaves in the flowering stage were higher than those of other rice plant structures. However, the type of terpenes found differed
between the panicles and the stems and leaves. Relative levels of β-caryophyllene in whole plants in the panicle-formation
stage and panicles in the flowering stage were much higher than that in stems and leaves in the flowering stage. Our previous
studies demonstrated that the odor from whole plants in the panicle-formation stage and panicles in the flowering stage is
attractive to rice leaf bugs. Here, the attractiveness of β-caryophyllene to adult bugs was investigated in olfactometer assays.
Adult females were attracted to β-caryophyllene at a concentration of 0.001%, which is approximately equivalent to the concentration
produced by flowering rice panicles. However, β-caryophyllene also was present in the odor of whole plants in the fourth-leaf
stage and in stems and leaves in the flowering stage. Furthermore, the amounts of this compound emitted from these structures
were similar. Therefore, we suggest that the relative abundance of this compound in a volatile blend is important for attractance
of the bugs. 相似文献
54.
A novel packet bit error rate (BER) and loss measurement method and system is proposed. A proposed 40 Gbit/s packet BER and loss measurement system is expressed in detail. A 40 Gbit/s BER and loss measurement with various conditions is demonstrated experimentally. In real time, only the payload part of a packet and burst stream with fluctuated guard time is evaluated. The BER and packet loss of a randomly received packet sequence due to routing and buffering can be also evaluated by the measurement system. A 10 Gbit/s packet BER and loss measurement with optical label switching, buffering, and preamble-free optical packet 3R are demonstrated experimentally. 相似文献
55.
Xuan Quy Tran Stuart D. McDonald Qinfen Gu Xin Fu Tan Kazuhiro Nogita 《International Journal of Hydrogen Energy》2017,42(10):6851-6861
Mg–Ni alloys are among the most promising candidates for solid-state hydrogen storage systems. This paper reveals the effect of Na doping in accelerating initial hydrogen uptake in Mg–Ni alloys using in-situ Synchrotron X-ray powder diffraction. A minimum concentration of approximately 0.2 wt.% Na must be achieved for the alloys to show reasonably fast hydriding kinetics. Surface analysis shows that a Na-modified Mg–Ni surface facilitates the chemisorption and dissociation of hydrogen molecules in the early stage of hydriding as evidenced by a rapid formation of the saturated hydrogen solid solution Mg2NiH0.3 from the original Mg2Ni. The subsequent hydrogen absorption is based on a mechanism of nucleation and growth of MgH2 where a high density of dislocations develops ahead of the growing hydride-metal interface. 相似文献
56.
57.
Kamran Sayrafian-Pour Wen-Bin Yang John Hagedorn Judith Terrill Kamya Yekeh Yazdandoost Kiyoshi Hamaguchi 《International Journal of Wireless Information Networks》2010,17(3-4):105-112
Information regarding the propagation media is typically gathered by conducting physical experiments, measuring and processing the corresponding data to obtain channel characteristics. When this propagation media is human body, for example in case of medical implants, then this approach might not be practical. In this paper, an immersive visualization environment is presented, which is used as a scientific instrument that gives us the ability to observe RF propagation from medical implants inside a human body. This virtual environment allows for more natural interaction between experts with different backgrounds, such as engineering and medical sciences. Here, we show how this platform has been used to determine channel models for medical implant communication systems. 相似文献
58.
59.
Jun-ichi Tomioka Kazuhiro Kiguchi Yohsuke Tamura Hiroyuki Mitsuishi 《International Journal of Hydrogen Energy》2011,36(3):2513-2519
The influence of environmental temperatures on the fatigue strength of compressed-hydrogen tanks for vehicles was investigated. The fatigue strength of Type-3 tanks was found to decrease in a low-temperature environment and increase in a high-temperature environment. The Type-3 tank has been subjected to autofrettage to improve fatigue strength. The investigation clarified that the effect of autofrettage changes according to the environmental temperature due to the difference between the coefficients of thermal expansion of carbon fiber reinforced plastic and aluminum alloy. This causes fatigue strength to change with changes in temperature. The Type-4 tank has a very long fatigue life and did not break after 45,000 cycles in a room-temperature or low-temperature environment. In a high-temperature environment, however, the tank broke in fewer than 45,000 cycles. The fatigue of carbon fiber reinforced plastic was promoted in the high-temperature environment, resulting in breakage of the tank. These results indicate that the fatigue strength of the tanks is influenced by the environmental temperature. 相似文献
60.
Kaoru Abe Yasuhiro Sakurai Akira Okuyama Kazuhiro Sasaki Kei Tawarada 《Journal of the science of food and agriculture》2009,89(6):1097-1100
BACKGROUND: The behavior of cadmium in ecosystems needs to be monitored because of the human toxicity of this heavy metal. The need recently arose for a simple and quick on‐site test for trace levels of Cd in food and environmental samples. In response, an immunochromatographic assay kit for detecting Cd was manufactured by Kansai Electric Power Co. of Japan. This kit uses the antigen–antibody complex reaction between the Cd–EDTA complex and an anti‐Cd–EDTA antibody and shows the results in terms of the degree of color developed on a test paper. We previously reported the successful use of this kit to determine Cd concentrations in brown rice. Here, we applied the kit to the determination of Cd concentrations in rice foliage and soil. RESULTS: Cadmium in rice foliage was not extracted successfully by the method used for brown rice. However, it was successfully extracted by 0.1 mol L?1 HCl solution at a rice foliage:HCl ratio of 1:20, and coexisting metals were removed sufficiently by the column treatment. The Cd concentrations determined by immunochromatographic assay were well correlated with the values obtained by acid decomposition and inductively coupled plasma mass spectrometry. The 0.1 mol L?1 HCl‐extractable Cd concentration in soil was also determined successfully with the kit. CONCLUSION: Approximate Cd concentrations in rice plants and 0.1 mol L?1 HCl‐extractable Cd concentrations in soil can be monitored easily and quickly by this method at locations where facilities for acid digestion and precision analysis are not available. Copyright © 2009 Society of Chemical Industry 相似文献