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Ihara T.,Norwegian University of Science and Technology | Ihara T.,Takenaka Research and Development Institute | Jelle B.P.,Norwegian University of Science and Technology | Jelle B.P.,Sintef | And 2 more authors.
Energy and Buildings | Year: 2016

Cool colored materials like membrane sheets and dried coatings exhibit higher reflectances in the near infrared region compared to conventional materials of the same color and are therefore desirable, as they provide energy economy and thermal comfort in cooling-dominated climates. They can also make reflective envelopes durable, owing to their lower surface temperatures. In this study, we experimentally show that different types of treated aluminum, like electrolytically anodized aluminum and aluminum with highly reflective baked-on coatings, can be employed as cool colored materials. Dark brown and light brown samples were examined in an accelerated aging test, and the optical properties and surface colors of the samples were compared with those of steels with reflective dried-on coatings. The treated aluminum samples exhibited stable optical properties and were durable. The accelerated aging tests, which involved exposure to ultraviolet radiation, heat, and water, were considered equivalent to actual long-term exposure, as evident from the decrease in gloss values of the samples. The aging conditions did not have a significant impact on the reflectances of the treated aluminum samples. Instead, our findings strongly suggest that the change in the reflectances of the tested samples may be due to accumulation of soil/dust and not due to surface aging. © 2015 Elsevier B.V. All rights reserved. Source


Yamada Y.,Takenaka Research and Development Institute
Proceedings of Forum Acusticum | Year: 2011

The potential capability of the active technique to suppress acoustic modes is verified by assuming the ideal condition under which a control model can be made determinate. A control experiment was conducted in a small rectangular room with the realistic scale as an architectural space. Results suggest that the sound field obtained using the Wiener filter would approach a globally controlled state if the number of control points is considerably increased. Also, it was actually confirmed that the global control only reduce the reverberant sound component and does not make any contribution to the direct sound. Source


Ihara T.,Norwegian University of Science and Technology | Ihara T.,Takenaka Research and Development Institute | Gustavsen A.,Norwegian University of Science and Technology | Jelle B.P.,Norwegian University of Science and Technology | Jelle B.P.,Sintef
Construction and Building Materials | Year: 2014

A highly reflective facade may enhance the durability of sealant joints. This study investigates that reflective facades reduce thermal movement loading to sealant joints due to less fluctuations of surface temperature, and therefore lower fatigue damage of sealant joints. Cumulative fatigue damage was calculated to less than 1.6% in the first year. This damage considering only the first year is not that large, however, serious fatigue damage would ensue from the accumulated deterioration of sealants during a longer period, e.g. 10-25 years. It is therefore recommended that the facade solar reflectance should be made as high as possible. © 2014 Elsevier Ltd. All rights reserved. Source


Ihara T.,Norwegian University of Science and Technology | Ihara T.,Takenaka Research and Development Institute | Gustavsen A.,Norwegian University of Science and Technology | Jelle B.P.,Norwegian University of Science and Technology | Jelle B.P.,Sintef
Applied Energy | Year: 2015

Properties of facade materials should be considered to determine which of them strongly affect building energy performance, regardless of the building shapes, scales, ideal locations, and building types, and thus may be able to promote energy efficiency in buildings. In this study, the effects of four fundamental facade properties related to the energy efficiency of office buildings in Tokyo, Japan, were investigated with the purpose of reducing the heating and cooling energy demands. Some fundamental design factors such as volume and shape were also considered. It was found that the reduction in both the solar heat gain coefficient and window U-value and increase in the solar reflectance of the opaque parts are promising measures for reducing the energy demand. Conversely, the reduction in the U-value of the opaque parts decreased the heating energy demand, and this was accompanied by an increase in the cooling energy demand in some cases because the total energy demands were predominantly for cooling. The above-mentioned promising measures for reducing building energy demands are thus recommended for use, and an appropriate U-value should be applied to the opaque parts based on careful considerations. This study provides some fundamental ideas to adjust the facade properties of buildings. © 2015 Elsevier Ltd. Source


Hata T.,Toyama Prefectural University | Kaneda K.,Takenaka Research and Development Institute | Tanikawa T.,Takenaka Research and Development Institute
International Journal of GEOMATE | Year: 2016

In recent years, erosion control has been increasingly implemented for land embankments of public roadways (e.g., express highways). In the field of geo-environmental engineering, it is important to develop an easy-to-use maintenance method for such embankments based on a natural process. This study aims to develop an eco-friendly and inexpensive maintenance method for embankment management. In this paper, the general concept of the newly proposed method is presented based on the results of laboratory tests and numerical simulations. The most important advantage of this method is the enhancement of urease activity in the in-situ microorganism community. Laboratory tests showed that microbial carbonate precipitation (MCP)-treated sand can increase the liquefaction strength. The numerical simulation results show that an MCP-treated embankment surface shows a rigid frame structure. These results show that the proposed method is suitable for use as an embankment maintenance method. Source

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