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Pyon, S.*; Kudo, Kazutaka*; Matsumura, Junichi*; Ishii, Hiroyuki*; Matsuo, Genta*; Nohara, Minoru*; Hojo, Hajime*; Oka, Kengo*; Azuma, Masaki*; Garlea, V. O.*; et al.
Journal of the Physical Society of Japan, 83(9), p.093706_1 - 093706_5, 2014/09
Times Cited Count:33 Percentile:82.71(Physics, Multidisciplinary)Nago, Makito*; Hagihara, Takeshi*; Minamide, Masashi*; Motoshima, Takayuki*; Jin, Kazumi; Kudo, Hajime; Sugita, Yutaka; Miura, Yoichi*
Dai-49-Kai Zenkoku Kensetsugyo Rodo Saigai Boshi Taikai Kenkyu Rombunshu (CD-ROM), p.77 - 80, 2012/10
This paper presents measures against gas emission during deep shaft excavation in the Horonobe Underground Research Laboratory Project (Horonobe URL Project). The gas control measures taken in the Horonobe URL Project include the following: (1) determination of the amount of methane contained in surrounding strata and groundwater, and gas concentration based on preliminary investigations, (2) determination of the specifications of fans, dust collectors, and ducts through ventilation network analysis (simulation), (3) reduction of methane gas emission through the use of waterproofing grout, (4) prohibition on the use of internal-combustion engine and the adoption of explosion-proof equipment, (5) development of methane gas control system, and (6) monitoring of methane gas emission. (3) to (6) described above are performed daily in the safety management activities and described in detail in this paper. The ventilation and eastern access shafts have currently reached a depth of 290 m and 250 m, respectively. The emission of methane gas has been observed to rise 0.3 % to 1.3 % in the fault zone, and it is controlled appropriately according to the gas control measures described above. As the measure to reduce the methane gas concentration, monitoring is confirmed to be effective.
Tsusaka, Kimikazu; Sugita, Yutaka; Kudo, Hajime
Doboku Gijutsu, 67(4), p.74 - 80, 2012/04
In this paper, the authors described a summery of the construction of the Horonobe Underground Research Laboratory and the technical features from the viewpoint of civil engineering. There are three important technical points in the construction. The first is the construction of shafts at great depth (500 m below the ground surface) through the soft sedimentary rocks. The second is pre-excavating grouting operation to fracture zone with high permeability. The third is to build gas-sensing system of methane dissolving in the groundwater in the drifts.
Shiraki, Fumiya*; Yoshikawa, Taeko*; Oshima, Akihiro*; Oshima, Yuji*; Takasawa, Yuya*; Fukutake, Naoyuki*; Oyama, Tomoko*; Urakawa, Tatsuya*; Fujita, Hajime*; Takahashi, Tomohiro*; et al.
Nuclear Instruments and Methods in Physics Research B, 269(15), p.1777 - 1781, 2011/08
Times Cited Count:8 Percentile:53.37(Instruments & Instrumentation)The graded energy deposition of heavy ion beam irradiation to polymeric materials was utilized to synthesize a novel proton exchange membrane (PEM) with the graded density of sulfonic acid groups toward the thickness direction. Stacked Poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) films were irradiated by Xe ion beam with the energy of 6 MeV/u under a vacuum condition. Irradiated films were grafted with styrene monomer and then sulfonated. The membrane electrode assembly (MEA) fabricated by the function graded PEM showed improved fuel cell performance in terms of voltage stability. It was expected that the function-graded PEM could control the graded concentration of sulfonic acid groups in PEM.
Oshima, Akihiro*; Shiraki, Fumiya*; Takasawa, Yuya*; Fujita, Hajime*; Yoshikawa, Taeko*; Tatsumi, Takahiro*; Tsubokura, Hidehiro*; Takahashi, Tomohiro*; Gowa, Tomoko*; Sakaue, Kazuyuki*; et al.
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Washio, Masakazu*; Shiraki, Fumiya*; Oshima, Yuji*; Takasawa, Yuya*; Fujita, Hajime*; Gowa, Tomoko*; Kudo, Hisaaki*; Oka, Toshitaka; Hama, Yoshimasa*; Murakami, Takeshi*; et al.
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Hagihara, Takeshi*; Nago, Makito*; Minamide, Masashi*; Ogawa, Hiroyuki*; Uyama, Mikinori*; Demma, Keisuke*; Kisu, Yoshio*; Morimoto, Tsutomu*; Kudo, Hajime; Tsusaka, Kimikazu
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Minamide, Masashi*; Hagihara, Takeshi*; Nago, Makito*; Ogawa, Hiroyuki*; Uyama, Mikinori*; Demma, Keisuke*; Kisu, Yoshio*; Morimoto, Tsutomu*; Kudo, Hajime; Tsusaka, Kimikazu
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Hagihara, Takeshi*; Nago, Makito*; Kudo, Hajime; Tsusaka, Kimikazu
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Igarashi, Toshifumi*; Ueda, Takahiro*; Hokora, Hideyuki*; Jo, Mayumi*; Kudo, Hajime
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Horonobe Underground Research Center, located in northern Hokkaido, Japan, has been excavating shafts and drifts of an underground research facility to establish general techniques for the assessment of deep geological environment. In this site, the groundwater seepage from the shafts and drifts as well as leachate from the excavated rock storage site contain high concentrations of total nitrogen. Ammonium-nitrogen (NH-N), the major nitrogen species in the seepage and leachate, has been removed by a nearby treatment facility. However, NH-N is easily oxidized to nitrite-nitrogen (NO-N) and nitrate-nitrogen (NO-N) by nitrification in the excavated rock storage site, which makes the removal process employed on site less effective. Therefore, column experiments that simulated the infiltration of rainwater through the storage site were carried out to understand the leaching and nitrification of nitrogen species and the factors affecting the phenomena. The results showed that the nitrification was inhibited when the rock layer was almost saturated, and that this process was temperature dependent. These indicate that nitrification can be mitigated by controlling hydrological conditions like water saturation.
Hagihara, Takeshi*; Minamide, Masashi*; Nago, Makito*; Ogawa, Hiroyuki*; Uyama, Mikinori*; Kisu, Yoshio*; Morimoto, Tsutomu*; Kudo, Hajime; Tsusaka, Kimikazu
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Minamide, Masashi*; Hagihara, Takeshi*; Nago, Makito*; Ogawa, Hiroyuki*; Uyama, Mikinori*; Kisu, Yoshio*; Morimoto, Tsutomu*; Yabuki, Yoshio*; Kudo, Hajime; Inagaki, Daisuke; et al.
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Minamide, Masashi*; Kudo, Hajime; Tsusaka, Kimikazu; Hagihara, Takeshi*; Ogawa, Hiroyuki*; Morimoto, Tsutomu*; Yabuki, Yoshio*; Nago, Makito*
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Taniguchi, Takumi; Irisawa, Keita; Ito, Yuzuru; Namiki, Masahiro; Osugi, Takeshi; Abe, Tomohisa; Sato, Junya; Sakakibara, Tetsuro; Nakazawa, Osamu; Meguro, Yoshihiro; et al.
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