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21.
Tomoki Nakayama Rie Hagino Yutaka Matsumi Yosuke Sakamoto Masahiro Kawasaki Akihiro Yamazaki Akihiro Uchiyama Rei Kudo Nobuhiro Moteki Yutaka Kondo Kenichi Tonokura 《Atmospheric environment (Oxford, England : 1994)》2010,44(25):3034-3042
A highly sensitive cavity ring-down spectrometer (CRDS) was used to monitor the aerosol extinction coefficient at 532 nm. The performance of the spectrometer was evaluated using measurements of nearly monodisperse polystyrene particles with diameters between 150 and 500 nm. By comparing the observed results with those determined using Mie theory, the accuracy of the CRDS instrument was determined to be >97%, while the upper limit for the precision of the instrument was estimated to be 0.6–3.5% (typically 2%), depending on the particle number concentration, which was in the range of 30–2300 particles cm?3. Simultaneous measurements of the extinction (bext), scattering (bsca) and absorption (babs) coefficients of ambient aerosols were performed in central Tokyo from 14 August to 2 September 2007 using the CRDS instrument, two nephelometers and a particle/soot absorption photometer (PSAP), respectively. The value of bext measured using the CRDS instrument was compared with the sum of the bsca and babs values measured with a nephelometer and a PSAP, respectively. Good agreement between the bext and bsca + babs values was obtained except for data on days when high ozone mixing ratios (>130 ppbv) were observed. During the high-O3 days, the values for bsca + babs were ~7% larger than the value for bext, possibly because the value for babs measured by the PSAP was overestimated due to interference from coexisting non-absorbing aerosols such as secondary organic aerosols. 相似文献
22.
Analysis of the ability of water resources to reduce the urban heat island in the Tokyo megalopolis 总被引:2,自引:0,他引:2
Simulation procedure integrated with multi-scale in horizontally regional-urban-point levels and in vertically atmosphere-surface-unsaturated-saturated layers, was newly developed in order to predict the effect of urban geometry and anthropogenic exhaustion on the hydrothermal changes in the atmospheric/land and the interfacial areas of the Japanese megalopolis. The simulated results suggested that the latent heat flux in new water-holding pavement (consisting of porous asphalt and water-holding filler made of steel by-products based on silica compound) has a strong impact on hydrologic cycle and cooling temperature in comparison with the observed heat budget. We evaluated the relationship between the effect of groundwater use as a heat sink to tackle the heat island and the effect of infiltration on the water cycle in the urban area. The result indicates that effective management of water resources would be powerful for ameliorating the heat island and recovering sound hydrologic cycle there. 相似文献
23.
Nakayama SM Ikenaka Y Hamada K Muzandu K Choongo K Teraoka H Mizuno N Ishizuka M 《Environmental pollution (Barking, Essex : 1987)》2011,159(1):175-181
Metal (Cr, Co, Cu, Zn, Cd, Pb, Ni) and metalloid (As) accumulation was studied in roadside soil and wild rat (Rattus sp.) samples from near a Pb-Zn mine (Kabwe, Zambia) and the capital city of Zambia (Lusaka). The concentrations of the seven metals and As in the soil samples and Pb in the rat tissue samples were quantified using atomic absorption spectroscopy. The concentrations of Pb, Zn, Cu, Cd, and As in Kabwe soil were much higher than benchmark values. Geographic Information System analysis indicated the source of metal pollution was mining and smelting activity. Interestingly, the area south of the mine was more highly contaminated even though the prevailing wind flow was westward. Wild rats from Kabwe had much higher tissue concentrations of Pb than those from Lusaka. Their body weight and renal Pb levels were negatively correlated, which suggests that mining activity might affect terrestrial animals in Kabwe. 相似文献
24.
Takeshi Yamaguchi Tomoki UmetsuYusuke Ishizuka Kenichi KasugaTakayuki Ito Satoru IshizawaKazuo Hokkirigawa 《Safety Science》2012,50(4):986-994
In this study, a new rubber surface pattern for a footwear sole was developed to prevent slip-related falls. This pattern shows a high static coefficient of friction (SCOF) and a high dynamic coefficient of friction (DCOF) when sliding against a liquid contaminated surface. A hybrid rubber block, in which a rubber block with a rough surface (Ra = 30.4 μm) was sandwiched between two rubber blocks with smooth surfaces (Ra = 0.98 μm), was prepared. The ratio of the rough surface area to the whole rubber block surface area r was 0%, 30%, 50%, 80%, and 100%. The coefficient of friction of the rubber blocks was measured when sliding against a stainless steel plate with Ra of 0.09 μm contaminated with a 90% aqueous solution of glycerol. While the SCOF increased with an increase of the rough surface area ratio r, the DCOF during steady-state sliding decreased with an increase of the rough surface area ratio r. The rough surface area ratio of 50% achieved a SCOF value around 0.5 or more and a DCOF value greater than 0.5. Furthermore, the difference in the value of the SCOF and DCOF was the smallest for the rubber block with r of 50%. The results indicated that the rubber block with r of 50% would be applicable to a footwear sole surface pattern to prevent slip and fall accidents on contaminated surfaces. 相似文献
25.
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
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This article proposes to analyze the quantitative effects of a gradual physical and "social" exhaustion of a landfill site on an equilibrium waste management service. A gradual social exhaustion of a landfill is defined here as an upward shift of a "subjective factor" associated with the amount of waste, based on the plausible hypothesis that an individual will not accept excessive presence of landfilled waste. Physical exhaustion occurs when the absolute capacity of a landfill site decreases. The paper shows some numerical examples using specific functions and parameters, and proposes appropriate directions for three policy objectives: to decrease the equilibrium waste disposal, to increase the economic surplus of the individual and/or the waste management firm, and to lower the equilibrium collection fee. 相似文献
29.
Ueda Hiroyuki Fukuta Rino Ohno Tomoki Moriyama Akihiro Himaki Takehiro Iwahashi Hitoshi Moritomi Hiroshi 《Journal of Material Cycles and Waste Management》2021,23(3):1071-1080
Journal of Material Cycles and Waste Management - Carbon-fiber-reinforced plastics (CFRPs) are used as structural materials in the aircraft and automotive industries owing to their lightweight and... 相似文献
30.
Yasukatsu Maeda Atsuyoshi Nakayama Norioki Kawasaki Kazuko Hayashi Seiichi Aiba Noboru Yamamoto 《Journal of Polymers and the Environment》1996,4(4):225-233
Chain-extension reactions were carried out using titanium-iso-propoxide (TIP) as a catalyst for a series of polyesters or copolyesterethers with low molecular weights (M
n
=1500–10,000) synthesized by the ring-opening copolymerization of succinic anhydride (SA) with ethylene oxide (EO). The copolymers having aM
n
from 25,000 to 50,000 of different properties were obtained. Both the melting point (T
m
) and the fusion heat (H), which indicate the crystallinity of the copolymers, rose with an increase in SA content in the copolymers. Semitransparent films were prepared by compression molding of the copolymers. The biodegradation of the copolymer films was evaluated by enzymatic hydrolysis by lipases and by an aerobic gas evolution test in standard activated sludge. The hydrolyzability of these copolymers by three kinds of lipases was affected by their copolymer composition SA/EO, form, andM
n
. The copolyesterether (SA/EO=43/57,M
n
=48,900) was more easily biodegraded by standard activated sludge compared to the polyester (SA/EO=47/53,M
n
=36,300).Presented at the Pacifichem-95, December 17–22, 1995, Honolulu, Hawaii. 相似文献