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Naoya Enomoto;Tang, Jun-Mu;Masato Uehara;Hideaki Maeda;Junichi Hojo;Nakagawa, Zenbe-e
- Proceedings of the Korea Association of Crystal Growth Conference
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- 2000.06a
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- pp.143-150
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- 2000
Wet-chemical process using ammonia to precipitate aluminum ion dissolved in a zirconia sol solution is examined. Formation of crystalline bayerite is unfavorable for fine dispersion of zirconia nanoparticles in alumina matrix after heat treatment. To avoid the bayerite formation, it was preferred to make a precipitation with a diluted ammonia or with an ammonia gas flow at high temperature. By optimizing the precipitation process and the calcination temperature, we successfully prepared the uniform microstructure in which tetragonal zirconia particles of ∼30nm is finely dispersed within the alumina grains.
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Tanaka, Kei;Hirowatari, Kotaro;Shimokawa, Kai;Watanabe, Satoshi;Matsushita, Daisuke;Furukawa, Akinori
- International Journal of Fluid Machinery and Systems
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- v.6 no.3
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- pp.152-159
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- 2013
A two-dimensional Darrieus-type hydroturbine system, installed with a wear for flow streams such as small rivers and waterways, has been developed for hydropower utilization of extra-low head less than 2m. There are several problems such as flow rate change and flowing wastes to be solved for its practical use in natural flow streams. In the present study, at first, a design guideline in the case of overflow or bypass flow is shown by using simple flow model. Next, in order to avoid the unexpected obstacles flowing into the hydroturbine, an installation of waste screening system is examined. It is confirmed that the screen is effective with some amount of bypass flow rate, however the output power is remarkably deteriorated.
https://doi.org/10.5293/IJFMS.2013.6.3.152 인용 PDF KSCI