Foamed plastic insulations installed into buildings are now expected to be long-lasting materials. However, in recent years, it has been reported that the foamed plastic insulation installed in the high-humid environment, such as under waterproof sheets on a rooftop, absorbs moisture and subsequently increases the thermal conductivity. The mechanism of moisture absorption is not sufficiently clear, and the test method for thermal conductivity of building insulating materials does not consider the influence of humidity. This study observed both moisture absorption and changes of physical properties of foamed plastic insulations after exposed at high humidity and discussed the moisture-induced deterioration.
This paper proposes a cost estimation sheet supporting decision making for city planning. The urban form is represented by 30 by 30 cells on the sheet and the cost is estimated regarding population distribution, population projection, maintenance cost of road network, water supply and sewerage network, and investment for new development site. The sheet first requests its user to input current population distribution and several cost parameters. Then the sheet designates the downtown cells. A distance from closest downtown cell is calculated for each cell, which is used for cost estimation. User will be asked to finalize the spatial plan where cells are given the following labels; downtown, to be developed as new sub centers, to be disengaged. The maintenance cost is calculated by number of cells, distance from closest downtown, and population within the cell. Finally, the sheet gives how long does it take until the saving of maintenance cost by disengagement will balance the development cost of new sub centers.
In this research, we propose a method to evaluate the adhesion of exterior tiles based on non-contact laser excitation/measurement technology using laser-induced plasma. In this method, laser ablation is used for excitation, and a laser Doppler vibrometer is used for measurement. A test specimen including tiles with insufficient adhesion is manufactured and evaluated. As a result of the laser excitation experiments, we found that the power spectrum increased in a specific frequency band at the floating part compared with the sound part. Furthermore, RT method was applied to the measurement data, resulting in a quantitative extraction of characteristic change due to the insufficient adhesion of the tiles.
In this research, we propose a method to evaluate the adhesion of exterior tiles based on non-contact laser excitation/measurement technology using laser-induced plasma. In this method, laser ablation is used for excitation, and a laser Doppler vibrometer is used for measurement. A test specimen including tiles with insufficient adhesion is manufactured and evaluated. As a result of the laser excitation experiments, we found that the power spectrum increased in a specific frequency band at the floating part compared with the sound part. Furthermore, RT method was applied to the measurement data, resulting in a quantitative extraction of characteristic change due to the insufficient adhesion of the tiles.