Time filter

Source Type

Chūō-ku, Japan

Kitakaze A.,Yamaguchi University | Itoh H.,Yamaguchi University | Komatsu R.,Yamaguchi University | Higuchi Y.,Godo Shigen Sangyo Co.
Canadian Mineralogist | Year: 2012

Baumstarkite, ideally AgSbS2, was found as aggregates of euhedral crystals in the Koryu mine, Hokkaido, Japan. The optical properties, chemical composition, and cell parameters of this mineral are presented. The compositional ranges are from 1.8 to 7.0 at.% As (7.4 to 28.2 mol.% AgAsS 2). The unit cell of a sample with 10 mol.% AgAsS 2 is triclinic, P1̄ with a 7.778(1), b 8.326(1), c 8.814(1) Å, α 100.90(1), β 104.01(1), γ 90.06(1)°, and V 543.2(1) Å3; these values are in very good accordance with those of the type mineral as well as those of synthetic material.

Molla M.Z.,Kyushu Institute of Technology | Mizukoshi N.,Godo Shigen Sangyo Co. | Furukawa H.,Kyushu Institute of Technology | Ogomi Y.,Kyushu Institute of Technology | And 3 more authors.
Progress in Photovoltaics: Research and Applications | Year: 2015

Transparent conductive oxide-less (TCO-less) dye-sensitized solar cells (DSSCs) have been fabricated and characterized using nanoporous TiO2-coated stainless steel metal mesh as flexible photoanode and cobalt bipyridyl complex (Co(bpy))-based one electron redox shuttle electrolyte. Attempts have been made towards enhancing the efficiency of TCO-less DSSCs to match with their TCO-based DSSC counterparts. It has been found that surface protection of metal mesh is highly required for enhancing the efficiency of TCO-less DSSCs specially using cobalt electrolytes as confirmed by dark current-voltage characteristics. Photocurrent action spectra clearly reveal that TCO-based DSSCs using (Co(bpy)) electrolyte exhibits photon harvesting (incident photon to current conversion efficiency (IPCE) 52%) in the 370-450 nm wavelength region as compared to photon harvesting at peak absorption of the dye (IPCE 56% at 550 nm), which is almost the same (IPCE 47%) in the 400-610 nm wavelength region for TCO-less DSSCs. Under similar experimental conditions, replacing indoline dye D-205 to porphyrin-based dye YD2-o-C8 led to the enhancement in the photoconversion efficiency from 3.33% to 4.84% under simulated solar irradiation. Copyright © 2014 John Wiley & Sons, Ltd.

Nakagawa T.,Kanto Natural Gas Development Co. | Suzuki I.,INPEX Corporation | Manabu N.,Godo Shigen Sangyo Co. | Ogatsu T.,Kanto Natural Gas Development Co. | Higuchi T.,Kanto Natural Gas Development Co.
IAHS-AISH Publication | Year: 2010

For four years from 1996 to 1999, the former Japan National Oil Corporation and eight companies developed the JARAS/3D simulator. This simulator is characterized by its ability to express two types of gas production performance in the Southern Kanto Natural Gas Field, and evaluate amounts of land subsidence associated with gas production. This simulator has already been used in several studies by the Environment Committee. This paper introduces this simulator. Copyright © 2010 IAHS Press.

Wakizono R.,Kyushu University | Sugai Y.,Kyushu University | Sasaki K.,Kyushu University | Higuchi Y.,Godo Shigen Sangyo Co. | Muraoka N.,Godo Shigen Sangyo Co.
Society of Petroleum Engineers - SPE Asia Pacific Oil and Gas Conference and Exhibition 2011 | Year: 2011

The brine that has been produced from water-dissolved natural gas reservoirs should be returned into reservoirs after the resources have been extracted to prevent the subsidence. However, the re-injectivity of the brine declines gradually; therefore, re-injection wells should be maintained by backwashing treatments. Colloidal materials like biofilms can be observed in solid materials that have been produced by the backwashing from the re-injection wells. Because the brine contains not only dissolved natural gas but also high levels of iodine, the iodine is also extracted from the brine chemically using sulfuric acid and oxidizing agent; therefore, re-injected brine contains sulfate and dissolved oxygen abundantly. These chemicals may stimulate the metabolites of microorganisms that have influences on the clogging; therefore, we considered the influences of these materials on microorganisms that may cause the clogging in this study. Column experiments were carried out using sand and brine that were collected in the gas field. The columns that the brine including indigenous microorganisms, dissolved oxygen and sulfate was injected into were clogged significantly. Iodide-oxidizing bacteria, iron-oxidizing bacteria and sulfate-reducing bacteria were found specifically in clogged columns, suggesting these microorganisms had influences on the clogging. In particular, Iodide-oxidizing bacteria were also found in original brine; therefore, it was assumed to have an important influence on the clogging. Iodide-oxidizing bacteria convert iodide into iodine that corrodes iron in the sand under the presence of dissolved oxygen. Iron (II) ion that has been eluted from the sand is oxidized to iron (III) ion by iron-oxidizing bacteria under the presence of dissolved oxygen. Iron (III) ion forms ferric hydroxide colloid in the brine and it causes the clogging of the porous media. From these mechanisms of the clogging, we can suggest removing dissolved oxygen as the most feasible countermeasures for the clogging. Copyright 2011, Society of Petroleum Engineers.

Tanishima M.,Kyoto University | Goto A.,Kyoto University | Lei L.,Kyoto University | Ohtsuki A.,Kyoto University | And 8 more authors.
Polymers | Year: 2014

Well-defined diblock and triblock copolymers, star polymers, and concentrated polymer brushes on solid surfaces were prepared using living radical polymerization with organic catalysts. Polymerizations of methyl methacrylate, butyl acrylate, and selected functional methacrylates were performed with a monofunctional initiator, a difunctional initiator, a trifunctional initiator, and a surface-immobilized initiator. © 2014 by the authors.

Discover hidden collaborations