Fukuoka-shi, Japan
Fukuoka-shi, Japan

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Yamashita S.,2 3 1 Matsukadai | Shimatani Y.,744 Motooka | Watanabe R.,8 19 1 Nanakuma | Moriyama T.,3 30 1 Wajiro | And 3 more authors.
Water Science and Technology | Year: 2013

In July 2009, the city of Fukuoka, Japan experienced a flood disaster along the Hii River, which runs through densely populated, concrete-covered areas of the city. The drainage system was overwhelmed and the river overflowed due to heavy rainfall and rapid runoff. The event led citizens in its watershed to plan and implement comprehensive flood control. The plan aims not only to mitigate floods but also to revitalize the river environment and populated communities in urban areas. This study reports the activities led by the citizens. They organized and carried out civic forums, workshops, and fieldwork to share views as to how the flood disaster was caused, how floods in the watershed should be controlled, and how the river environment should be rehabilitated. This study illuminates how people, including the flood victims and municipal engineers, can change drastically and communicate effectively in the course of discussing and implementing the comprehensive flood control measures. © IWA Publishing 2013.

Yamaguchi T.,8 19 1 Nanakuma | Lee K.,8 19 1 Nanakuma | Yamauchi M.,8 19 1 Nanakuma | Fukuyama N.,8 19 1 Nanakuma | Yoshida K.,8 19 1 Nanakuma
Bunseki Kagaku | Year: 2015

Raman scattering measurements were conducted at 25 - 350 °C and 40 MPa on a 1 mol dm-3Mg(NO3)2 aqueous solution. Along with elevating temperature, the N-O v1 band of the nitrate ion at 1050 cm- 1 shifts to a lower wave number, whereas the O-D v1 band of a water molecule does to a higher wave number at 2540 cm-1. For the both bands, an inflection point was observed at around 200 °C, suggesting a structure change in the hydration shell of nitrate ion and the solvent water hydrogen network. Energy-dispersive X-ray diffraction measurements were also performed at 25 - 210 °C and 40 MPa on a 1 mol dm-3 Mg(NO3)2 aqueous solution. The experimental structure factors were subjected to empirical potential structure refinement (EPSR) modeling to reveal 3D structures of solvent water, ion hydration and ion-pairs. For solvent water, there was no significant structure change in the first coordination shell of a water molecule, but the number of the second coordination shell decreased from 10.5 at 25 °C and 0.1 MPa to 8.5 at 210 °C and 40 MPa. A Mg2+ ion is surrounded by six water molecules in an octahedral manner at 25 °C and 0.1 MPa. At 210 °C and 40 MPa one nitrate ion enters the first coordination shell of Mg2+ to form a contact ion pair in a monodentate fashion with a Mg-ON -N bond angle of about 150°. About 11 water molecules surround a central nitrate ion without specific coordination sites over the measured temperature range, except for a slight decrease in the coordination number of the nitrate ion at 210 °C and 40 MPa, probably due to the formation of a Mg2+ -NO3- ion pair. © 2015 The Japan Society for Analytical Chemistry.

Tanaka M.,8 19 1 Nanakuma
Journal of Physics: Conference Series | Year: 2010

Tsallis entropy, which is one of nonextensive entropies, gives a q-normal distribution as an equilibrium probability density function. Although a q-normal distribution is popular, there exists a problem what it means by calculating an expectation value with a corresponding escort distribution not a q-normal distribution itself. But we have an amazing property such that an escort distribution obtained by a q-normal distribution with a parameter q and a variance is another q-normal distribution with a different value of q and a scaled variance. Therefore calculating an expectation value with an escort distribution corresponds to calculating the expectation value with another q-normal distribution, that is to say, an escort distribution is nothing but another q-normal distribution. However it still remains the question why an expectation value should be calculated by another q-normal distribution. We call the procedure to get another q-normal distribution from a q-normal distribution through an escort distribution τ-transformation. This τ-transformation keeps a support of a q-normal distribution invariant, and makes the tails of a q-normal distribution thicker/thinner depending on a value of q. Thus a τ-transformation looks like a kind of multiresolutional analysis, if we consider a q-normal distribution as a window function. © 2010 IOP Publishing Ltd.

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