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51.
The reaction of nitrogen dioxide (NO2) with cholesterol was investigated. NO2 reacted with the hydroxyl group in cholesterol to produce cholesteryl nitrite. In this reaction, other minor products were observed. Cholesteryl nitrate, however, was not detected as was reported by other workers. Water accelerates and oxygen retards this reaction. 相似文献
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Kato Takahiro Hatakeyama Takeshi Sugawara Katsuyasu 《Journal of Material Cycles and Waste Management》2021,23(4):1636-1645
Journal of Material Cycles and Waste Management - Biomass has been attracting attention as an environmentally friendly energy resource due to concerns about global environmental problems. Chromated... 相似文献
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Takahiro?TsukaharaEmail authorView authors OrcID profile
return OK on get Kana?Oyagi Yasuo?Kawaguchi 《Environmental Fluid Mechanics》2016,16(3):521-537
We introduce a new approach to diffusion-source estimation for quick identification of the unknown source, based on Taylor’s diffusion theory for turbulent transport of passive scalar from a fixed point source. In order to evaluate the method, we used planar laser-induced fluorescence to measure the concentration field of fluorescent dye in water flowing in a channel. We considered two kinds of datasets: basis data and observed data. The former is used to determine the basis functions characterizing the streamwise dependence of variances for three statistics: the mean concentration, root-mean-square (RMS) of fluctuations in the concentration, and RMS of the temporal gradient of the fluctuating concentration. Consistent with Taylor’s theory, we found that the lateral distribution of each statistic was basically Gaussian, and their standard deviations increased as a function of the square root of the distance from the emitted point. Based on these facts, a basis function can be formulated and expected to be valid for estimation of unknown sources. Source estimation was performed with the observed data, which corresponded to limited available information about the concentration from an unknown point source. We confirmed a good prediction accuracy of the proposed method with an averaged bias as small as the turbulent integral scale. Better precision was achieved by employing several statistics simultaneously. In this case, the standard deviation of the estimated source position was assessed at 14 % of the mean distance between the source and measurement points, after 100 source-estimate trials with different datasets. The methodology tested in this paper is expected to be applicable more general and complex environmental diffusion issues involving anisotropic turbulent dispersion, and space–time variable mainstream systems; but its versatility in such systems is currently under investigation. 相似文献
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Ako AA Shimada J Hosono T Kagabu M Ayuk AR Nkeng GE Eyong GE Fouepe Takounjou AL 《Environmental geochemistry and health》2012,34(5):615-639
Groundwater is the only reliable water resource for drinking, domestic, and agricultural purposes for the people living in the Mount Cameroon area. Hydrogeochemical and R-mode factor analysis were used to identify hydrogeochemical processes controlling spring water quality and assess its usability for the above uses. Main water types in the study area are Ca-Mg-HCO(3) and Na-HCO(3). This study reveals that three processes are controlling the spring water quality. CO(2)-driven silicate weathering and reverse cation exchange are the most important processes affecting the hydrochemistry of the spring waters. While tropical oceanic monsoon chloride-rich/sulfate-rich rainwater seems to affect spring water chemistry at low-altitude areas, strong correlations exist between major ions, dissolved silica and the altitude of springs. In general, the spring waters are suitable for drinking and domestic uses. Total hardness (TH) values indicate a general softness of the waters, which is linked to the development of cardiovascular diseases. Based on Na?%, residual sodium carbonate, sodium adsorption ratio, and the USSL classification, the spring waters are considered suitable for irrigation. Though there is wide spread use of chemical fertilizers and intense urban settlements at the lower flanks of the volcano, anthropogenic activities for now seem to have little impact on the spring water quality. 相似文献
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The gas phase equilibrium calculation for the C‐H‐O system at atmospheric pressure and temperature from 773 to 1773 K at intervals of 250 K was performed to understand the generation and decomposition behavior of dibenzo‐p‐dioxin (DD), dibenzo‐p‐furan (DF) and biphenyl (BP) in relation to the existing oxygen potential. It is possible to categorize these results into three regions from the viewpoint of this potential: region (A), region (B) and region (C) are that of the higher, modest and lower oxygen potential, respectively. In region (A), the equilibrium amounts of DD, DF and BP are nearly zero. In region (B), they increase once and then decrease with rise in temperature. In the most characteristic region (C), they increase uniformly with rise in temperature. 相似文献
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Shin-ichi Sakai Takahiro Ukai Hiroshi Takatsuki Kazuo Nakamura Sayuri Kinoshita Takumi Takasuga 《Journal of Material Cycles and Waste Management》1999,1(1):62-74
Previous reports have focused on the emission of coplanar polychlorinated biphenyls (Co-PCBs) which have a toxic mechanism
similar to that of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/DFs) released from municipal solid waste (MSW) incineration. Such emissions
accounted for a small percentage of all the dioxins (PCDDs/DFs and Co-PCBs) recorded at the toxicity equivalent (TEQ) level.
There is, however, very little information about Co-PCBs, such as the quantities being released and their effect on overall
environmental pollution. The aim of this research has been to clarify the substance flow of Co-PCBs from MSW incineration
processes. The results reveal that whereas the input of Co-PCBs into the MSW incineration facilities in Kyoto City was 0.13–0.29 μg-TEQ
per ton waste, the total output of Co-PCBs (the sum of Co-PCBs released from emission gas, fly ash, and bottom ash) was 4.9 μg-TEQ
per ton waste. The total output was therefore found to be higher than the total input. Over 90% of the total PCBs were decomposed
in the incineration process. In comparing the profiles of congeners and homologues, those in the MSW were found to be similar
to those detected in the atmosphere and products containing PCBs, but different from those in the MSW incineration gas.
Received: August 26, 1998 / Accepted: March 2, 1999 相似文献