• Title/Summary/Keyword: Tokyo Metropolitan

Search Result 245, Processing Time 0.026 seconds

Development of a 1500N-thrust Swirling-Oxidizer-Flow-Type Hybrid Rocket Engine

  • Sakurazawa, Toshiaki;Kitagawa, Koki;Hira, Ryuji;Matsuo, Yuji;Sakurai, Takashi;Yuasa, Saburo
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2008.03a
    • /
    • pp.849-854
    • /
    • 2008

  • We have been developing a 1500N-thrust Swirling-Oxidizer-Flow-Type hybrid rocket engine. In order to put the engine into practical use, we conducted long duration burning experiments up to 25s to examine the influence of configuration change of fuel grain on the engine performance and designed an LOX vaporization nozzle to supply GOX for the 1500N-thrust engine. The experiment with a small hybrid rocket engine showed that combustion was stable and the engine performance was approximately constant during combustion. There was no essential problem to with increasing combustion time. The LOX vaporization nozzle designed had 30 rectangular channels with a depth of 0.5mm. During passing through the nozzle, the LOX increased in temperature and vaporized sufficiently.

  • PDF

Emission of Biogenic Volatile Organic Compounds from Trees along Streets and in Urban Parks in Tokyo, Japan

  • Matsunaga, Sou N.;Shimada, Kojiro;Masuda, Tatsuhiko;Hoshi, Junya;Sato, Sumito;Nagashima, Hiroki;Ueno, Hiroyuki
    • Asian Journal of Atmospheric Environment
    • /
    • v.11 no.1
    • /
    • pp.29-32
    • /
    • 2017

  • Ozone concentration in Tokyo Metropolitan area is one of the most serious issues of the local air quality. Tropospheric ozone is formed by radical reaction including volatile organic compound (VOC) and nitrogen oxides ($NO_x$). Reduction of the emission of reactive VOC is a key to reducing ozone concentrations. VOC is emitted from anthropogenic sources and also from vegetation (biogenic VOC or BVOC). BVOC also forms ozone through $NO_x$ and radical reactions. Especially, in urban area, the BVOC is emitted into the atmosphere with high $NO_x$ concentration. Therefore, trees bordering streets and green spaces in urban area may contribute to tropospheric ozone. On the other hand, not all trees emit BVOC which will produce ozone locally. In this study, BVOC emissions have been investigated (terpenoids: isoprene, monoterpenes, sesquiterpenes) for 29 tree species. Eleven in the 29 species were tree species that did not emit BVOCs. Three in 12 cultivars for future planting (25 %) were found to emit no terpenoid BVOCs. Eight in 17 commonly planted trees (47%) were found to emit no terpenoid BVOC. Lower-emitting species have many advantages for urban planting. Therefore, further investigation is required to find the species which do not emit terpenoid BVOC. Emission of reactive BVOC should be added into guideline for the urban planting to prevent the creation of sources of ozone. It is desirable that species with no reactive BVOC emission are planted along urban streets and green areas in urban areas, such as Tokyo.

  • https://doi.org/10.5572/ajae.2017.11.1.029 인용 PDF KSCI

Target-Composition Effect on Hydroxyapatite Thin Films Coated on Titanium by r.f. Sputtering

  • Hamagami, Jun-ichi;Kokubu, Daisuke;Umegaki, Takao;Yamashita, Kimihiro
    • The Korean Journal of Ceramics
    • /
    • v.4 no.4
    • /
    • pp.372-376
    • /
    • 1998

  • Using calcium-phosphate-powder targets with the Ca/P ratios of 1.0-1.67, hydroxyapatite ($Ca_{10}(PO_4)_6(OH)_2$, HAp) thin films with 4-7㎛ thickness were prepared on titanium metal plates by r.f. magnetron sputtering, followed an annealing at $200^{\circ}C$ for 24 hr under a high water vapor pressure using an autoclave. All the specimens were systematically characterized by XRD, FT-IR, SEM and EDS analyses. The post-annealed films were confirmed to be a nonstoichiometric oxyhydroxyapatite by XRD and FT-IR measurements.

  • PDF