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11.
TOMIOKA Kenichi OGUMA Koichi SEKITatsuya 《环境化学》2003,22(3):211-214
1 IntroductionLeadiswellknownasoneofthemosttoxicmetalsandnotedinthefieldofenvironmentalchemistry[1 ] .Theleadconcentrationinnaturalwaterisextremelylow (sub μg·l-1 level)sothatsomepreconcentrationstepmustbeincludedtoassurethesensitivityofaconventionalin… 相似文献
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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
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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
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Behnisch PA Hosoe K Shiozaki K Kiryu T Komatsu K Schramm KW Sakai S 《Environmental science and pollution research international》2002,9(5):337-344
Control of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in emissions and thermal residues from incinerators has been a cause of public concern for more than one decade. Recently, several studies showed that other persistent organic pollutants (POPs) such as coplanar polychlorinated biphenyls (co-PCBs) also have dioxin-like activity and are released from incinerators. Therefore, the present study was aimed at making a risk assessment about dioxin-like activity in extracts of thermal waste residues (e.g. combustion gas; fly ash, slag) from incineration and melting processes in Germany and Japan. For this purpose, polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), coplanar polychlorinated biphenyls (co-PCBs), polychlorinated naphthalenes (PCNs) and polyaromatic hydrocarbons (PAHs) were analyzed by chemical analysis. Additionally, 2, 3, 7, 8-TCDD equivalents (EROD-TEQs) were determined by in vitro Micro-EROD bioassay using rat H4IIE hepatoma cells. EROD-TEQs could be correlated to I-TEQ values (from PCDD/Fs/co-PCBs) analyzed by chemical analysis resulting in a maximal sixfold higher estimate. Our study indicates minor influences of co-PCBs, PAHs and PCNs to the sum of dioxin-like toxicity in the extracts of thermal waste residues as determined here. Furthermore, we showed that the levels of dioxins and co-PCBs contained in slag from melting processes and bottom ashes from incineration processes were lower by 1-2 orders of magnitude than that in fly ash. 相似文献
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Hanaoka K Ohno H Wada N Ueno S Goessler W Kuehnelt D Schlagenhaufen C Kaise T Irgolic KJ 《Chemosphere》2001,44(4):743-749
Water-soluble arsenic compound fractions were extracted from seven species of jellyfishes and subjected to analysis by high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) for arsenicals. A low content of arsenic was found to be the characteristic of jellyfish. Arsenobetaine (AB) was the major arsenic compound without exception in the tissues of the jellyfish species and mucus-blobs collected from some of them. Although the arsenic content in Beroe cucumis, which preys on Bolinopsis mikado, was more than 13 times that in B. mikado, the chromatograms of these two species were similar in the distribution pattern of arsenicals. The nine species of jellyfishes including two species treated in the previous paper can be classified into arsenocholine (AC)-rich and AC-poor species. Jellyfishes belonging to Semaostamae were classified as AC-rich species. 相似文献
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Nguyen Cao Don Hiroyuki Araki Nguyen Thi Minh Hang Hiroyuki Yamanishi Kenichi Koga 《Environment, Development and Sustainability》2008,10(2):219-231
Groundwater is an important resource in the alluvial coastal lowland plains. In the Shiroishi lowland plain, southwestern
Kyushu Island of Japan, land subsidence due to groundwater development has long been recognized as an environmental issue.
Land subsidence can have several negative economic and social implications. In this study, an integrated numerical groundwater
and land subsidence model, which combines a three-dimensional numerical groundwater flow model and a one-dimensional soil
consolidation model, was used to simulate the dynamic groundwater flow and ground subsidence due to pumping. On the other
hand, a groundwater optimization model was also formulated to search for an optimal safe yield of groundwater pumping without
violating physical, environmental, social-economic constraints. The model results reveal that groundwater levels in the aquifers
greatly vary from season to season in response to varying climatic and pumping conditions. Consequently, land subsidence has
rapidly occurred throughout the area with the central prone in Shiroishi plain. The study also proposes a countermeasure against
subsiding process in the area by means of numerical models. The optimization model result suggests that pumping can be increased
in the northern part of the study area without leading to significant land subsidence. 相似文献
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Trends in waste plastics and recycling 总被引:2,自引:0,他引:2
Tadao Kasakura Reiji Noda Kenichi Hashiudo 《Journal of Material Cycles and Waste Management》1999,1(1):33-37
Zero emission is an ambitious project aimed at the conversion of the conventional top-down or one-directional flow type production
systems of modern society to those of a recycling type. The basic idea underlying this project is to understand in detail
the material flow mechanism in a particular segment of society and to evaluate the transformability of the hitherto one-directional
types of process into recycling types. The authors, members of the Zero-Emission Research Group of Japan, are investigating
the material flow of plastics in Japan. The present work describes the features of this project, as well as the results obtained
so far.
Received: May 28, 1998 / Accepted: October 16, 1998 相似文献
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The bioconcentration factors (BCFs) of seven new aryl fluoroalkyl ethers--four bis-4-tetrafluoroethoxyphenyl-type (bis-type) compounds and three mono-4-tetrafluoroethoxyphenyl-type (mono-type) compounds--were obtained by bioconcentration tests using common carp. The BCFs of 4 of the 7 ethers were higher than 5000, indicating their high bioconcentration potential. The bioconcentration characteristics of the bis-type compounds were different from those of the mono-type compounds and non-fluoro diphenylmethanes with a similar skeleton structure to the bis-type compounds, in taking longer to reach a plateau and having a slower elimination rate and in their distribution patterns in the fish body. The BCF of 1 bis-type compound was much higher than the value predicted by an accepted correlation equation between BCF and P(ow). In addition, the logP(ow) of the bis-type compounds calculated by commercially available computer software was remarkably different from that measured. 相似文献