Original Paper
Permeability of underground rock mass influenced by mining
Kazuo AOKI, Haruyuki ISHIHARA (Geomechanics Div., Geotechnology Dept., NIRE)
Takehiro ISEI (Safety Engineering Dept., NIRE)
Tetsuro ESAKI (Faculty of Engineering, Kyushu Univ.)
Abstract
We discussed permeability of underground rock mass with mined out space based on in-situ hydrological data. Consequently, it was found that coal minings caused an increase of the permeability of rock mass and the change in groundwater flow. The main factor to induce the hydrological change is that the rock mass around mined out space have been deteriorated by mining. The coefficient of permeability of rock in deteriorated areas is about 10-3-10-4cm/s and that in non-deteriorated areas is about 10-5-10-6cm/s. And, the deteriorated areas have been formed upward in the upper strata of goaf.
Key words : permeability, coal mine, groundwater
(Language:Japanese)
Original Paper
Syntheses of Carbonate and Carbamate Esters from Carbon Dioxide,
Alcohols, and tert-Amines Mediated by Acetylene
Yoshiyuki SASAKI and Ken-ichi Tominaga (Chemical Process Div., Global Warming Control Dept., NIRE)
Abstract
It was found that the acetylene-mediated reaction of carbon dioxide, ethanol, and triethylaminegave diethyl carbonate, the selectivity of which reached up to 78% based on amine converted. When prim- or sec-amine was used in place of alcohol, corresponding carbamic acid esters were formed in poor to fair yields. On the other hand, N, N-diethylaminoalkyldiethylcarbamates were mainly formed together with diols in the reaction of carbon dioxide with N, Ndiethylaminoalcohols in the presence of acetylene.
This reaction provides a new method for the fixation of carbon dioxide into useful organic compounds, carbonic acid diesters and carbamic acid esters.
Key words : Carbon Dioxide, Carbonate, Carbamate, Acetylene
(Language:Japanese)
Original Paper
A Numerical Analysis of the Diffusion of Volcanic Gases
Hiroaki KONDO (Department of Environmental Inpact Asessment)
Tateki MIZUNO (Deputy Director General)
Fa-hua LIU and Hisashi FUKUDA (CRC Research Institute, Inc.)
Abstract
The diffusion of volcanic gases from Mt. Aso (in Kumamoto prefecture) and Mt. Adatara (in Fukushima prefecture) was investigated by a numerical model with the aid of wind tunnel and water tank experiments. The gases of Mts. Aso and Adatara are SO2 and H2S respectively. The emission rate from Mt. Aso in stable conditions can be estimated as 40t/day, but that from Mt. Adatara is uncertain. The concentration outside of the crater of Mt. Aso extends to downstream side of the crater. The area where tourists can visit suffers from high concentration (higher than 2ppm) under northerly wind. There are some visible source points of the gas in the bottom of the crater of Mt. Adatara but the results of numerical analysis do not show the high concentration at the point in the surrounding wall of the crater, where the accident occurred.
Key words : volcanic gas, SO2, H2S, Diffusion in the mountains
(Language:Japanese)
Original Paper
Ecological processes for Environmental Impact Assessment in Coastal Waters
Kimitoshi Ishikawa (Environmental Assessment Dept., NIRE)
Abstract
This paper focuses on a method for estimating adverse effects on natural environment by economic development in coastal waters in Japan. In particular, the most critical relations concerning the impact on marine organisms is pointed out and discussed according to an environmental impact assessment.
Relations between environmental impact assessment and marine organisms needs a quantitative ecological approach in order to succeed in sustainable development of coastal waters management. Recently, the Environment Agency of Japan pointed out the unreliability and the theme on accuracy and the staff for biology and ecology in the environmental impact study. Ecological response to environmental impact occurs in a wide spectrum of physiological and biological functions. Therefore biological monitoring measures must correspond to the given time-space scale of natural mechanisms. For the evaluation of environmental impact, it is desire able to develop of experimental technics and collect biological and ecological basic data for the object. I recomended the following: 1. Reconstructing a clearlistic EIA process by EIA agencies and practitioners, 2. Scorping the biological and ecological issues by EIA professionals, 3. Using the current computer technology, 4. Considering monitoring
systems over scales of time and space for the ecological target and 5. Making available to public all monitoring data and reports of EIA.
Finally, some subjects and hints are presented for an implementation of an environmental impact study.
Key words : Environmental Impact Assessment (EIA), Coastal waters, Ecological process
(Language:Japanese)
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