＜Scienceへの論文掲載のお知らせ①＞

当社のコンサルティング企業の株式会社大勇フリーズの

凍結工法の技術について、慶應義塾大学・環境情報学部・教授の

武藤佳恭先生（冨田賢の博士号の指導教授。冨田の博士研究はこちら！）と、

大久保太陽社長の共著論文が、なんと、著名な科学ジャーナルの

「Science」のeLettersに掲載されました！2017年5月14日

Ice-like water supports hydration forces and eases sliding friction

に対する下記のeLetterです！

こちら！→http://advances.sciencemag.org/content/2/8/e1600763/tab-e-letters

PDF：eLetter_Ice-like water supports hydration forces and eases sliding friction _ Science Advances

（元の論文：Main_Paper_Ice-like water supports hydration forces and eases sliding friction _ Science Advances　）

Confined unfrozen water plays a key role for water pipe repairs

• Yoshiyasu Takefuji, advisor/professor,Keio University
• Other Contributors:
  Taiyo Okubo, inventor/CEO,Daiyufreeze

(14 March 2017)

Nishad Dhopatkar and et al. mentioned the analyzed behavior of the confined water in their paper(1). In the latest water pipe repairs, double-ice-plug freezing using liquid nitrogen is used in Japan (2). Freezing water creates an ice plug to stop water flow. The new method uses double-ice-plug freezing instead of single-ice-plug freezing. Freezing the confined water surrounded by two ice plugs in water pipe creates the third ice-plug. The static adhesive strength of double-ice-plug freezing is roughly four times higher than that of single-ice-plug. The confined unfrozen water plays a key role for achieving the very high ice adhesive strength by taking advantage of water expansion upon freezing in the pipe.

References
(1) Nishad Dhopatkar and et al., ice-like water supports hydration forces and eases sliding friction, Science Advances, 26 Aug 2016, Vol.2, no.8, e1600763
(2) https://patents.google.com/patent/JP2000028076A/en

Competing Interests: None declared.

★大勇フリーズさんのWebサイトの当該記事は、こちら！

＜Scienceへの論文掲載のお知らせ②＞

また、同じく、当社のコンサルティング先企業の株式会社新潟テクノの

フィルムに関する技術の武藤佳恭先生と佐々木社長の共著論文も、

下記のように、Scienceに掲載されました！2017年3月31日

Scalable-manufactured randomized glass-polymer hybrid metamaterial for daytime radiative cooling

に対する下記のeLetterです。

こちら！→http://science.sciencemag.org/content/355/6329/1062/tab-e-letters

(31 March 2017)

During the solar radiation peaks, Fig.4C shows that cooling power of the proposed method (1) dramatically decreases. It is because the volume of the hybrid metamaterial is not sufficient. Fig.S2A in the supplementary material indicates that the maximum refractive index is about 22 degree (arctangent((80cm/2)/100cm)=21.8). Because of 90/21.8=4.1, overlaying five films should make less likely to become hot. Because of 22-(22*5-90)=2, the near-perfect reflection can be achieved. In other words, cooling power can be improved by overlaying metamaterials.

References:
1. Yao Zhai, et al., Scalable-manufactured randomized glass-polymer hybrid metamaterial for daytime radiative cooling, Science 355, 1062–1066 (2017)

Competing Interests: None declared.

(18 February 2017)

I’m not a Science subscriber so haven’t read the full article, just the Abstract and the summary published in The Economist. I noted that The Economist stated that a pump would be required to circulate water in a practical application of this technology to cooling buildings. In fact, since the warming part of the water circuit is at the bottom (the rooms) and the cooling part of the water circuit is at the top (the roof), a pump may not be required, as the thermosiphon effect will circulate the water naturally. This would require careful design and, probably, larger pipe diameters in parts of the circuit than a pumped system, but would offer substantial benefits in running costs, maintenance and reliability.

Competing Interests: None declared.

Scienceは、世界トップの科学ジャーナルであり、そこに、当社コンサルティング先企業２社の技術が掲載されたことは、たいへん誇らしいことと考えております。

大勇フリーズさん、新潟テクノさん、このたびは、おめでとうございます！

慶應大学・武藤先生、ありがとうございました！