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Ogawa M.,Osaka Institute of Technology | Okimori Y.,General Environmental Technos Co.
Australian Journal of Soil Research | Year: 2010

In Asian countries, people have a long history of using rice husk charcoal or wood ash as an agricultural soil amendment, but evidence of this has been long obscured. Since the 1980s, microbiological studies, mainly on symbiotic organisms, have been performed in Japan. Charcoal is a porous material with high water and air retention capacities and high alkalinity. Therefore, it stimulates root growth and enhances the infection of various symbiotic microbes to plant partners. The use of carbonised materials in agriculture, forestry, and construction will contribute to the sustainability of crop production, soil conservation, and carbon sequestration. Biochar-related research accumulated mainly in Japan is reviewed. © CSIRO 2010.

Moriizumi Y.,Yokohama National University | Matsui N.,General Environmental Technos Co. | Hondo H.,Yokohama National University
Journal of Cleaner Production | Year: 2010

Sustainable mangrove management needs to consider trade-offs between multiple benefits provided by mangrove ecosystems and to balance the conflicting objectives of various stakeholders. The aim of the present study is to assess the sustainability of mangrove management based on the life cycle approach. We examine two mangrove management systems in Thailand, namely, the strict preservation and charcoal production systems. The results show that the strict preservation system has an advantage over the charcoal production system from the environmental perspective (the net amount of CO2 absorbed by mangroves) while the charcoal production is a more favorable system than strict preservation from the social perspective (the amount of employment created in local communities). On the other hand, it is difficult to say that both systems are sustainable from an economic aspect. The charcoal production system needs to develop improved management regimes for commercial charcoal production and requires financial assistance in the period when its net cash flows are negative. As solutions for these problems, the introduction of community forest management and the utilization of a fund for REDD (Reducing Emissions from Deforestation and Degradation in Developing Countries) can be proposed. © 2010 Elsevier Ltd. All rights reserved.

Fujioka M.,Japan Coal Energy Center | Yamaguchi S.,Akita University | Nako M.,General Environmental Technos Co.
International Journal of Coal Geology | Year: 2010

The feasibility of extracting gas from coal seam while storing carbon dioxide underground was evaluated in Japan. A CO2-ECBM project had begun near the town of Yubari on the island of Hokkaido in northern Japan. The primary coal seam of interest was a 5-6m thick Yubari coal seam located at the depth of 900m. A micro-pilot test with a single well and multi-well CO2 injection tests, involving an injection and production wells, were carried out in the period between May 2004 and October 2007. There were a variety of tests conducted in the injection well, including an initial water injection fall-off test and a series of CO2 injection and fall-off tests. Although gas production rate was obviously enhanced by CO2 injection, water production rate was not clearly affected by CO2 injection. Several injection tests suggested that injectivity of CO2 into the virgin coal seam saturated with water was eventually increased as the water saturation near the injector was decreased by the injected CO2. It was estimated that low injectivity of CO2 was caused by the reduction in permeability induced by coal swelling. N2 flooding test was performed in 2006 to evaluate the effectiveness of N2 injection on improving well injectivity. The N2 flooding test showed that daily CO2 injection rate was boosted, but only temporarily. Moreover, the permeability did not return to the initial value after CO2 and N2 were repeatedly injected. It was also indicated that the coal matrix swelling might create a high stress zone near to the injection well. © 2010 Elsevier B.V.

Orihara T.,Tottori University | Sawada F.,2 11 12 Tsujido taiheidai | Ikeda S.,Forest Development Technological Institute | Yamato M.,General Environmental Technos Co. | And 5 more authors.
Mycologia | Year: 2010

During taxonomic revision of genus Octaviania in Japan we examined herbarium and fresh specimens of O. columellifera and O. asterosperma sensu S. Yoshimi & Y. Doi with morphological and molecular techniques. These two species were identical in both macro- and micromorphological characters and were clearly different from the generally known O. asterosperma. The identity of the two species and their distinctness from O. asterosperma was further supported by both nuclear large subunit and ITS rDNA phylogeny. The molecular analyses also revealed that O. columellifera shares its lineage with the boletoid mushroom-forming Xerocomus chrysenteron complex and that it does not form a monophyletic clade with other Octaviania species. Our morphological reevaluation, including transmission electron microscopic observation of basidiospores, clarified the taxonomic boundary between O. columellifera and other Japanese Octaviania species. Accordingly we propose a new genus, Heliogaster, for O. columellifera with designation of the lectotype. We discuss phylogenetic relationships with Octaviania sensu stricto species and the closely related boletoid (pileate-stipitate) fungi, generic characters of Helio-gaster and intraspecific phylogeny. © 2010 by The Mycological Society of America.

Kimura J.-I.,Japan Agency for Marine - Earth Science and Technology | Gill J.B.,University of California at Santa Cruz | Kunikiyo T.,WORLD Survey and Design Co. | Osaka I.,IZUTEC Co. | And 10 more authors.
Geochemistry, Geophysics, Geosystems | Year: 2014

In response to the subduction of the young Shikoku Basin of the Philippine Sea Plate, arc magmas erupted in SW Japan throughout the late Cenozoic. Many magma types are present including ocean island basalt (OIB), shoshonite (SHO), arc-type alkali basalt (AB), typical subalkalic arc basalt (SAB), high-Mg andesite (HMA), and adakite (ADK). OIB erupted since the Japan Sea back-arc basin opened, whereas subsequent arc magmas accompanied subduction of the Shikoku Basin. However, there the origin of the magmas in relation to hot subduction is debated. Using new major and trace element and Sr-Nd-Pb-Hf isotope analyses of 324 lava samples from seven Quaternary volcanoes, we investigated the genetic conditions of the magma suites using a geochemical mass balance model, Arc Basalt Simulator version 4 (ABS4), that uses these data to solve for the parameters such as pressure/temperature of slab dehydration/melting and slab flux fraction, pressure, and temperature of mantle melting. The calculations suggest that those magmas originated from slab melts that induced flux melting of mantle peridotite. The suites differ mostly in the mass fraction of slab-melt flux, increasing from SHO through AB, SAB, HMA, to ADK. The pressure and temperature of mantle melting decreases in the same order. The suites differ secondarily in the ratio of altered oceanic crust to sediment in the source of the slab melt. The atypical suites associated with hot subduction result from unusually large mass fractions of slab melt and unusually cool mantle temperatures. Key Points Slab melts generate various magma types in SW Japan arc Numerical mass balance geochemical model revealed source conditions of magmas Origin of magma genesis between hot and cold subduction zones is discussed © 2014. American Geophysical Union. All Rights Reserved.

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