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121.
Keiichi Hayashi Naruo Matsumoto Evangeline T. Hayashi Tahirou Abdoulaye Hitoshi Shinjo Ramadjita Tabo Ryoichi Matsunaga Satoshi Tobita 《Nutrient Cycling in Agroecosystems》2012,92(3):289-304
To determine the efficiency of utilization of organic matter in agricultural production, nitrogen flow was estimated within
a village-farm model in the west of Niger, West Africa. Nitrogen was focused on in this study as it is known to be a major
nutrient component of organic matter and one of the limiting nutrients in Sahelian soil. Local practices regarding the use
of organic matter and pertinent information on traditional practices for soil fertility management were determined by interviews
with local farmers. To estimate nitrogen flow in farmlands and consumption in the village through various activities, quantitative
measurements of crop yield and organic amendment were carried out. Data on human and livestock excreta were taken from published
reports. The size and classification of farmlands were as follows: 0.5 ha adjacent farmland, 1.6 ha threshing farmland, 6.0 ha
transported-manure farmland, 5.5 ha corralling farmland, and 86.5 ha extensively managed farmland (EMF). Levels of nitrogen
flow from these farmlands to the studied villages were 0.9, 2.9, 9.6, 15.2, and 94.2 Mg, while the flows to these farmlands
were 14.6, 6.3, 13.7, 17.5, and 26.3 Mg, respectively. Upon calculation of nitrogen balance −8 kg ha−1 year−1 was estimated in EMF, but there was a positive balance in other types of farmland, which ranged from 4 to 262 kg ha−1 year−1, indicating inefficient use of nitrogen in the study area for crop production. The results indicated that nutrient flow in
the study site was unequally distributed and nitrogen was not recycled. Therefore, efforts should be made to establish efficient
utilization of available nutrients by reducing the loss from livestock feed and human consumption. At the same time, more
research is needed to improve the management of EMF. 相似文献
122.
Yuya Mukainakano Kaori Yoshida Kazu Okumura Kimio Kunimori Keiichi Tomishige 《Catalysis Today》2008,132(1-4):101-108
Pd–Ni bimetallic catalysts prepared by co-impregnation and sequential impregnation methods were compared in the catalytic performance in oxidative steam reforming of methane. The sequential impregnation was more effective to the suppression of hot spot formation. According to the structural analysis by in situ quick-scanning X-ray absorption fine structure (QXAFS) during the temperature programmed reduction, the sequential impregnation method gave the bimetallic particles with higher Pd surface composition because of the low possibility of the Pd–Ni bond formation. Higher surface composition of Pd with higher reducibility than Ni is connected to the enhancement of the catalyst reducibility and the suppression of the hot spot formation. 相似文献
123.
Keiichi Kaneto Hisashi Fujisue Kentaro Yamato Wataru Takashima 《Thin solid films》2008,516(9):2808-2812
Isotonic load stress dependence of biomimetic soft actuators based on polypyrrole tubes has been studied to elucidate the work behaviour. Polypyrrole (PPy) tubes were electrochemically prepared on gold coated acryl resin in an aqueous solution of pyrrole and dodecylbenzensulfonic acid (DBS). The tubes were operated electrochemically in aqueous 1 M LiCl, and the change of tube length was measured under various load stresses. It was found that with increasing load stresses the response time slowed down and the contraction ratio reduced. Hence, the current decreased and lasted longer, indicating that the tube was sensing the load stress. During contraction of the tube, the conversion efficiency was estimated from the electrical input and mechanical output energies to be 0.12%. The maximum volumetric work was approximately 120 kJ/m3. The results were discussed taking the dynamics of ion migration into consideration. 相似文献
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125.
Kou Sugawara Takeshi Nobukawa Masanori Yoshida Yoshihiro Sato Kazu Okumura Keiichi Tomishige Kimio Kunimori 《Applied catalysis. B, Environmental》2007,69(3-4):154-163
Effect of the loading amount of Fe over ion-exchanged Fe-MFI catalysts on the catalytic performance of N2O reduction with NH3 was investigated, and the results indicated that the turnover frequency (TOF) was almost constant in the Fe/Al range between 0.05 and 0.40. The activity of N2O + NH3 reaction was much lower than that of N2O + CH4 reaction over Fe-MFI (Fe/Al = 0.40), and the preadsorption of NH3 decreased drastically the activity of N2O + CH4 reaction. The temperature-programmed desorption (TPD) of NH3 showed the formation of stronger acid sites on Fe-MFI (Fe/Al = 0.24 and 0.40), and the amount of the acid sites agrees well with the desorption amount O2 in O2-TPD in the low temperature range. The acid sites gave a 3610 cm−1 peak (Brønsted acid) in FTIR observation. These results suggest that the acid sites were formed on the bridge oxide ions in binuclear Fe species. Adsorbed NH3 on the strong acid sites inhibited N2O dissociation, which can be related to the low activity of N2O + NH3 reaction over Fe-MFI with high Fe loading. 相似文献
126.
Keiichi Hiramoto Mitsuko Imao Eisuke F Sato Masayasu Inoue Akitane Mori 《Journal of the science of food and agriculture》2008,88(7):1151-1157
BACKGROUND: Fermented papaya preparation (FPP) from yeast fermentation of Carica papaya Linn is a natural health food that is commercially sold in Japan. A previous study revealed that FPP has antioxidant activity. However, the effect of FPP on allergic diseases remains unclear. The aim of the present work was to examine whether the oral administration of FPP to mice restrained two types of contact hypersensitivity models, FITC (Th2 type) induced ear and colon oedema, and oxazolone (Th1 type) induced ear and colon oedema. RESULTS: The sensitisation of FITC or oxazolone increased the plasma levels of IL‐10, IFN‐γ, and TNF‐α. Histological examinations revealed a marked increase of IgA, dendritic cells and inflammatory cells in the colon. When the animals were given FPP before sensitisation by FITC or oxazolone, all the events induced by either FITC or oxazolone decreased markedly. CONCLUSION: These results suggest that the oral administration of the FPP may have a therapeutic potential for the prevention of contact hypersensitive immuno‐response. Copyright © 2008 Society of Chemical Industry 相似文献
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129.
Keiichi Watanuki 《Journal of Mechanical Science and Technology》2010,24(1):257-262
When designing universal design products or their interfaces, it is necessary to have knowledge about the environment in which
the target product is going to be used. Product development should consider the interaction between the envisaged product
or a demo product with the same functions on the one hand, and the users on the other, as well as observing the everyday activities
of typical users, understanding the procedures and methods for using the product and subsequently pinpointing the areas which
are problematic or in need of improvement. To evaluate whether the designed product is easy to use, and to improve its usability,
it is also essential to record the perceptions of the people, the movement characteristics, the operability, any mental or
physical stress, and so on. There is a need for products and environments which are easily applicable to various people and
utilizational setups. In this paper, we present the development of a tangible design review system which makes use of virtual
reality technology to display a close model of the actual product, making readily available not only visual information but
also the perception of volume and weight through the fusion of kinesthetic information, enabling many people to communicate
easily while experiencing this virtual reality. Furthermore, the design review of universal design products which makes use
of this system will be discussed. 相似文献
130.
Jinting Jiu Keiichi Murai Keunsoo Kim Katsuaki Suganuma 《Journal of Materials Science: Materials in Electronics》2010,21(7):713-718
Silver nanorods have been successfully synthesized in high yield by a polyol process in the presence of FeCl3. The yield and morphology of the silver particles from these conditions were dependant on the concentration of FeCl3, and the molar ratio of the capping agent to AgNO3. The optimized conditions for the synthesis of the nanorods were: 20 μM of FeCl3 and a molar ratio of 1.8:1 of capping agent to AgNO3. The nanorods produced were used to form a silver layer at 400 °C with a low electrical resistivity of 6.1 × 10−6 Ω cm. The silver layer was applied as die-attachment films to connect a SiC chip to a copper substrate. This formed a porous
structure, which was evaluated for structure and strength. 相似文献