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Fujiia T.,Institute for Geo Resources and Environment | Endo K.,Tohoku University | Nakagawa S.,Tohoku University | Sato Y.,Tohoku University | And 3 more authors.
Energy Procedia | Year: 2013

The purpose of this study is to examine the CO2 sorption amount for Kimachi sandstone and Berea sandstone in water-saturated and air-dry states using the pressure decay method (manometric method) at 50 °C and pressure of up to 20 MPa and to provide useful information for assessing the effect of water saturation state on sorption behavior of CO2 in host reservoir rocks.


Fujii T.,Institute for Geo Resources and Environment | Uehara S.-I.,Toho University | Sorai M.,Institute for Geo Resources and Environment
Energy Procedia | Year: 2014

In this study, we investigated effective pressure of dependence on hydraulic properties (i.e. threshold pressure and permeability) of Kazusa group mudstones, which is taken from Boso peninsula in Japan, at 40°C and effective pressures up to 20 MPa. Additionally, to assess a correlation between these properties, a porosity change depending on effective stress is also examined. Our results demonstrates that for mudstones tested, the relationship between threshold pressure and permeability depends strongly on changes in pore structures as a function of effective pressure. © 2014 The Authors Published by Elsevier Ltd.


Hiradate S.,Japan National Institute for Agro - Environmental Sciences | Morita S.,Japan National Institute for Agro - Environmental Sciences | Hata K.,Tokyo Metroplitan University | Hata K.,Institute for Geo Resources and Environment | And 4 more authors.
Catena | Year: 2015

To conserve indigenous natural ecosystem and help in the recovery of natural vegetation on Nakoudojima Island, which is a subtropical oceanic island in Ogasawara Islands in Japan, we clarified the mechanisms of the changes in soil chemical properties as affected by soil erosion and seabird activities on the island. Under grassland vegetation where influence of feral goat (exotic species) had been severe, the chemical properties of surface soils with a thickness of 5cm were variable even in a small area of 0.375 km2; pH(H2O) value range between 4.6 and 6.9, total C content range between 0.36 and 5.62%, total N content range between 0.03 and 0.45%, exchangeable acidity range between 0.5 and 50mmolckg-1, and plant-available phosphate (Bray II P) range between 0.4 and 170 mg P2O5 100 g-1. By clarifying soil profile characteristics under natural and disturbed vegetation and distribution patterns of these soils on the island, the changes in the soil chemical properties were reasonably assigned to the effect of soil erosion caused by feral goats for increased soil exchangeable acidity and decreased soil pH (mainly found in inland area) and to the effect of seabird activities for increased Bray II P and soil exchangeable acidity and decreased soil pH (mainly found in outer rim area with high altitude). It was also clarified that the high soil exchangeable acidity was significantly related to the low productivity of plant biomass for these plots (P<0.01). Soil erosion would have removed surface soils having weak acidity and exposed subsoils having strong acidity to the ground surface, resulting in inhibition of plant growth and delay of vegetation recovery. Based on the findings obtained in the present study, several options were proposed to stop soil erosion and to recover the vegetation, although careful preliminary examination would be necessary for applying them. © 2015 Elsevier B.V.


Miyazaki K.,Japan National Institute of Advanced Industrial Science and Technology | Aoki K.,Japan National Institute of Advanced Industrial Science and Technology | Tenma N.,Japan National Institute of Advanced Industrial Science and Technology | Sakamoto Y.,Institute for Geo Resources and Environment | Yamaguchi T.,Toho University
Proceedings of the ISOPE Ocean Mining Symposium | Year: 2011

A nonlinear elastic constitutive model for artificial methane-hydrate- bearing sediment samples was presented. The triaxial compressive properties reported in an earlier work were analyzed to examine the applicability of Duncan-Chang model. The presented constitutive model considers the dependences of the mechanical properties of the samples on methane hydrate saturation and effective confining pressure. Copyright © 2011 by The International Society of Offshore and Polar Engineers (ISOPE).


Mori C.,University of Tokyo | Sato T.,University of Tokyo | Kano Y.,University of Tokyo | Kano Y.,Institute for Geo Resources and Environment | Aleynik D.,Scottish Association for Marine Science
Energy Procedia | Year: 2013

To quantify the risk and impact of CO2 seepage to the marine ecosystem, the Quantifying and Monitoring Potential Ecosystem Impacts of Geological Carbon Storage project is now undergoing in a bay in Scotland. In advance of the field experiment of this project, we conducted the numerical simulation of CO2 seepage. From this numerical study, we predicted how CO2 behave in the bay and how the condition of the sea changes.


Tosha T.,Institute for Geo Resources and Environment | Sakaguchi K.,Renewable Energy Research Center
AIST Today (International Edition) | Year: 2014

The impact of large-scale developments like those of geothermal power plants on hot springs, is ongoing cause for concern. The use of heat pumps allows heating and cooling in areas where it is difficult to use ground heat sources with previous technology. In the case of photovoltaic power generation, the amount of power that can be generated at a particular location can be calculated approximately by measuring the solar insolation and daylight hours. Using the 'Geothermal Potential Map in Japan' published by AIST, it is possible to evaluate geothermal resources. It is estimated that if all the geothermal reservoirs of 150°C or above throughout Japan were developed without restrictions. AIST is currently engaged in research aimed at creating an improved geothermal resource map.


Sanematsu K.,Institute for Geo Resources and Environment | Ishihara S.,Geological Survey of Japan
Resource Geology | Year: 2011

40Ar/39Ar dating was conducted on the Da Lien granite related to greisen-skarn type polymetallic (W-CaF2-Cu-Bi-Au) mineralization in Nui Phao, northern part of Vietnam in the South China Plate. Biotite and muscovite separates from the biotite-muscovite granite and greisenized granite indicate four plateau ages: 82.2 ± 0.4Ma, 82.8 ± 0.3Ma, 81.5 ± 0.3Ma and 82.5 ± 0.4Ma. The plateau ages were not significantly influenced by excess 40Ar in dated minerals or by loss of radiogenic 40Ar due to hydrothermal activities. The results indicate that solidification of granite related to the polymetallic mineralization occurred in the Late Cretaceous between 82.8Ma and 81.5Ma. © 2011 The Authors. Resource Geology © 2011 The Society of Resource Geology.


Yanagisawa N.,Institute for Geo Resources and Environment
Transactions - Geothermal Resources Council | Year: 2015

In geothermal field, the fluid geochemistry of several production well changed with operation of geothermal power plant. The change of fluid geochemistry affects to scale properties. For example, the Kakkonda geothermal field, North-eastern Japan, several deep reservoir is developed until the boundary between Quaternary Kakkonda granite and Pre-Tertiary formations. On progress of production the fluids from deep reservoir suffered by the fluid of shallow reservoir and meteoritic water. With temperature of production well decreasing and chemical composition changed, silica precipitation decreased and the metal sulfide mineral assemblage of scales of Well-13 changed from chalcocite (Cu2S), loellingite (FeAs2) and native antimony (Sb) to tetrahedrite (Cu10[Fe,Zn]2[As,Sb]4S3). © Copyright (2015) by Geothermal Resources Council All rights reserved.


Sanematsu K.,Institute for Geo Resources and Environment
AIST Today (International Edition) | Year: 2010

Rare earth elements (REE) are considered to be seventeen elements consisting of lanthanoids, yttrium, and scandium. Deposits that supply rare earth resources can be divided into two categories igneous deposits formed by ignoeus rocks or associated hydrothermal activity and weathering deposits created from weathered rocks. Weathering deposits include laterite deposits, ion-adsorption type deposits, and placer deposits. The ore minerals contaning REEs consists of carbonates, phosphates, oxides and ion-adsorption clays. With ion-adsorption clays containing kaolinite and other materials as REE are electrically adsorbed onto the mineral surfaces, they can be recovered by ion exchange using a mild acid without decomposing the minerals themselves. Identification of heavy rare earth materials (HREE) deposits and of REE minerals are two of the challenges facing research on REE deposits.


Tosha T.,Institute for Geo Resources and Environment
AIST Today (International Edition) | Year: 2014

The 'Renewable Energy Research Center' which focuses on research and development of solar and wind power generation, energy storage and transport, and system integration technology, as well as geothermal and shallow geothermal energies, was also established under the research institute. When GSHIP systems are used in Japan, the efficiently of heat exchange under the ground clearly depends on the groundwater flow. The research center will be conducting groundwater surveys to create potential maps for the GSHP system for the plains and basins of the Tohoku district, identifying appropriate locations for applications of GSHP systems, and formulating design guidelines for borehole heat exchangers. This will be done through partnerships with universities, the Fukushima Prefecture Hi-tech Plaza, and local companies.

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