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11.
T. Matsuda M. Yashima M. Nifuku H. Enomoto 《Journal of Loss Prevention in the Process Industries》2001,14(6):449-453
The dust explosion committee of the Association of Powder Process Industry and Engineering, Japan recently established two testing standards for dust explosions. In the investigations for the standardization, many experimental data have been obtained for the dusts currently used in Japanese industries. Data for zirconium, tantalum and silicone dusts are presented to discuss the use of test methods, which have been accepted internationally. The test methods for dust explosions have to consider a variety of kinds and forms of dusts to be tested. 相似文献
12.
Junichi Okuyama Takashi Kitagawa Kei Zenimoto Shingo Kimura Nobuaki Arai Yoshikazu Sasai Hideharu Sasaki 《Marine Biology》2011,158(9):2055-2063
We used Lagrangian numerical simulations to examine the trans-Pacific dispersal processes of loggerhead turtle hatchlings.
Ten thousand simulated particles were released from each of the three nesting regions in Japan and tracked for 5 years. Results
showed many particles moving eastward, drifting in the Kuroshio Current followed by the Kuroshio Extension Current. However,
no particles reached Baja California, a known feeding area, through passive processes, indicating that trans-Pacific transportation
requires active swimming by turtles. The duration of the trans-Pacific dispersal was estimated to be at least 1.6–3.4 years,
with some turtles drifting in the Kuroshio Countercurrent and remaining in the western Pacific even after 5 years. This indicates
that as revealed by previous genetic studies, not all loggerheads always disperse along a trans-Pacific route. The findings
showed that survival and expected growth rates varied widely according to ambient temperatures during drifting, which in turn
depended on nesting location. 相似文献
13.
The basic properties of poly(lactic acid) produced by the direct condensation polymerization of lactic acid 总被引:8,自引:0,他引:8
M. Ajioka K. Enomoto K. Suzuki A. Yamaguchi 《Journal of Polymers and the Environment》1995,3(4):225-234
Poly(lactic acids) with high molecular weights have been synthesized by direct condensation polymerization of lactic acid. These polymers have good mechanical properties and can be processed into products such as cups, film, and fiber, which can be used as compostable materials. This polymerization method can be applied to the synthesis of copolymers of lactic acid and other hydroxyacids. The properties of poly(lactic acid) and copolymers synthesized by the direct process are different from those of polymers obtained by the conventional lactide process. 相似文献
14.
Arsenic water pollution is a big issue worldwide. Determination of inorganic arsenic in each oxidation state is important because As(III) is much more toxic than As(V). An automated arsenic measurement system was developed based on complete vaporization of As by a sequential procedure and collection/preconcentration of the vaporized AsH(3), which was subsequently measured by a flow analysis. The automated sensitive method was applied to monitoring As(III) and As(V) concentrations in contaminated water standing overnight. Behaviors of arsenics were investigated in different conditions, and unique time dependence profiles were obtained. For example, in the standing of anaerobic water samples, the As(III) concentration immediately began decreasing whereas dead time was observed in the removal of As(V). In normal groundwater conditions, most arsenic was removed from the water simply by standing overnight. To obtain more effective removal, the addition of oxidants and use of steel wools were investigated. Simple batch wise treatments of arsenic contaminated water were demonstrated, and detail of the transitional changes in As(III) and As(V) were investigated. 相似文献
15.
16.
Fertilization success and sexual behavior in male medaka, Oryzias latipes, exposed to tributyltin 总被引:5,自引:0,他引:5
Nakayama K Oshima Y Yamaguchi T Tsuruda Y Kang IJ Kobayashi M Imada N Honjo T 《Chemosphere》2004,55(10):1331-1337
We evaluated the effects of tributyltin (TBT), polychlorinated biphenyls (PCBs), and a mixture of TBT and PCBs on reproduction, gonadal histology, and sexual behavior in Japanese medaka (Oryzias latipes). We administered TBT (1 microg g(-1) body weight [b.w.] daily), PCBs (1 microg g(-1) b.w. daily), or both to medaka for 3 weeks. We assessed reproductive success during week 3 and the sexual behavior of male medaka after the exposure period. Fertilization success was significantly decreased in groups that received TBT. The profiles of fertility developed a bimodal distribution in the TBT and TBT+PCBs groups, and the numbers of males that performed "following" and "dancing" were significantly decreased in the TBT+PCBs group. The frequency of "dancing" also decreased after treatment with TBT, whereas fish that received PCBs only showed no difference in sexual behavior. Testes that had oocytes showed normal spermatogenesis, even though two of the five males treated with TBT+PCBs had some indication of testis-ova, which did not occur in any other group. Our results indicate that TBT, but not PCBs, affects sexual behavior and reproduction in medaka. 相似文献
17.
We investigated the epilithic diatom assemblage of samples collected from three sites of the Hakata River, Fukuoka, Japan, on November 26, 2008. Each taxon was photographed and identified. The 1747 diatom frustules collected were classified into 33 taxa belonging to 17 genera. Nitzschia fonticola was abundant at all sites. The DAIpo (the diatom assemblage index to organic water pollution) values for sites 1, 2, and 3 were 50.2, 44.1 and 48.0, respectively, indicating that the water quality of the Hakata River was at β-mesosaprobic level. 相似文献
18.
Amemiya Takashi Denou Masato Enomoto Hiroshi Ito Takuya Kaibe Kenji Sawada Naomi Tomari Miyuki Matsumura Yukihiko 《Environmental science and pollution research international》2021,28(37):51060-51071
Environmental Science and Pollution Research - There is an abundance of woody biomass in Japan. However, its economic feasibility is limited. There have been several discussions on whether... 相似文献
19.
Kei Nakagawa Kazuro Momii Ronny Berndtsson 《Environmental Modeling and Assessment》2011,16(4):335-342
Groundwater under agricultural lands is often contaminated by nitrate. In southern Japan, aquifers are covered by volcanic
ash soils that can leach nitrate to the groundwater. In this study, column experiments using two volcanic ash soils (Kuroboku
and Akahoya) were carried out. A mixed solution of KNO3 and K2SO4 was used in the leaching experiments. Based on the experiments, a reactive transport model was developed using the Constrained
Interpolation Profile method for ion transport and used to calculate chemical equilibrium for the cation exchange reactions.
Anion adsorption was modeled by retardation in the numerical model. The developed simulation model results were compared to
results obtained by the reactive transport model PHAST. The developed model was shown to quite well reproduce general characteristics
of the experimental results. Also, the developed model results agreed well with results from PHAST. Slight discrepancy between
observed and calculated breakthrough curves was probably caused by ignoring the kinetic reaction in the model calculations. 相似文献
20.
Kei Sato Akinori Takami Tasuku Isozaki Toshihide Hikida Akio Shimono Takashi Imamura 《Atmospheric environment (Oxford, England : 1994)》2010,44(8):1080-1087
From measurements by an Aerodyne Aerosol Mass Spectrometer (AMS), secondary organic aerosol (SOA) formed in laboratory chambers is believed to be less oxidized than well-oxidized ambient organic aerosol (OA). However, the mass spectrum of SOA formed from the photo-oxidation of aromatic hydrocarbons has not been sufficiently studied by using AMS though these reactions are potential sources of urban SOA. In this study, we studied SOA formed from the photo-oxidation of seven aromatic hydrocarbons by using Time-of-Flight AMS. Strong mass signals from SOA were found at m/z 43 (m43) and 44 (m44) in all the experiments. The m44 to total organic aerosol mass ratio (m44/OA) increased with irradiation time. For example, the m44/OA ratio increased from 10.6% to 13.3% during irradiation for 11 h in an experiment with toluene. The average m44/OA ratios were determined to be 5.8–17.1% for all the experiments. The m44/OA decreased and the m43/OA increased with increasing number of alkyl substituents of precursor aromatic hydrocarbons. This is because low-reactive ketones are preferentially produced rather than aldehydes with increasing number of alkyl substituents. The m44/OA ratios of the benzene and monoalkylbenzene oxidation were 12.2–17.1% and were close to those of well-oxidized ambient OA. These findings are consistent with the hypothesis that the photo-oxidation of aromatic hydrocarbons is a potential source of urban SOA. In addition to oxygenated organic compounds, organic nitrogen oxides were also shown to be present in SOA by high-resolution mass spectra. 相似文献