The guideline of dust control for tunnel construction works, published by the Ministry of Health, Labor and Welfare of Japan, dictates that the employer has a management duty to control the suspended dust density for the safety of workers in the tunnel construction work. The "Digital dust Indicator"(DDI) is the most accurate instrument for dust density measurements. However, DDI is also expensive.
  In this paper, the authors propose a dust density measuring method which measures the dust density from the digital image which carried out the flash photography. The feasibility test of real tunnel construction site, there was the high correlation in this study and DDI, and the effectiveness of this new method was confirmed.

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  A combined system of DHS (Down-flow Hanging Sponge) reactor and following USB (Up-flow Sludge Blanket) reactor, was applied for biological nitrogen removal from landfill leachate. The DHS and the USB reactors were employed, respectively, as a nitrification process and as a denitrification process. The system performance with respect of nitrogen removal was evaluated by feeding an actual landfill leachate containing 158 mg NH₄⁺-N/L and high salinity (approx. 22200 mg Cl^-/L) for an experimental duration of 400 days.
  The system exhibited a satisfactory nitrogen removal of 90% at an ammonium-nitrogen loading rate of 0.30 kg N/m³-spomge/d and HRT of 15 h (12 h for DHS reactor and 3 h for USB reactor, respect ively). The DHS seems reasonably promising as an energy-saving and high-rate nitrification process, since it requires neither external aeration input nor tedious operation -and -maintenance.

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  In this study, we developed a GIS-based decision support system to integrate plans of block renewal and sustainable energy management at a regional level. We also designed four block renewal scenarios and two technological options on future energy system for three types of block with different density, and estimated CO₂ reduction potential applying the developed system to Yokohama. From the study, we reached the following conclusions; 1) CO₂ emission in 2050 could be reduced by 48-70% through innovating new energy system for renewal block, 2) the micro grid system would have higher potential of CO₂ emission reduction than the heat pump system in commercial detached house block, 3) the construction of low-density urban area could bring the most CO₂ emission reduction.

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  A finite difference analysis method is developed to simulate outdoor sound field considering the effects of ground surface geometry and wind flow over complex terrains. The perfectly reflective boundary conditions are investigated for various ground surface geometries. Then the mass consistent model of wind field is employed to consider the effects of the wind on the sound field. It is verified that the numerical results with the perfectly reflective boundary conditions used in this study agree well with the results of the mirror image models. In addition, this numerical analysis properly simulated the sound field under the effects of wind flow over complex terrains.

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  Microbial community structure in a G3-type Down-flow Hanging Sponge (DHS) reactor was investigated by rRNA approach. Cloning analyses indicated that the microbial community structure was successionally changed along with the height of the reactor. Dechloromonas sp. was predominant at the upper portion of the reactor, indicating contribution of this group to organic removal. Ammonia-and nitrite-oxidizers were quantified by quantitative real-time PCR, which revealed that the populations of both groups gradually increased along with the height of the reactor. A part of reasons for stable treatment of the DHS reactor is found by the microbial community structure analysis.

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  The accurate information on vegetation-covered area as a pervious surface is necessary to improve the accuracy of runoff analysis for non-point pollutant loading and groundwater recharge in urban region. In this study, practical bisection method for distinguishing vegetation from non-vegetation in urban regions was proposed. The Green Bias Index (GBI) which is derived from the strong relationship between the red edge and green edge in high resolution satellite image stands for the pigment property of vegetation as the bias terms of the green reflectance between near-infrared and red reflectance. Through the application of the GBI in study area, the vegetation higher than 99.7% to ground truth data could be identified, while the misidentification rate from non-vegetation is lower than 0.2% and 0.1% in roof and road, respectively. The width error between identified and measured vegetations was zero to one pixel for eleven sites selected in the study area. Finally, the spatial and temporal variance of GBI was investigated with five satellite images obtained on different date and location.

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