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151.
To understand the characteristics of non-methane hydrocarbon (NMHC) abundance in an urban air of Nagoya, one of the metropolitan areas of Japan, 48 species of C2–C11 NMHCs were measured with a measurement system, developed in this study, by using gas chromatography with flame ionization detection (GC/FID) continuously for one year from December 2003 to November 2004.Annual mean concentration of NMHCs in normal and propylene equivalent (PE) in Nagoya was compared with those in four urban areas of Seoul, London, Lille, and Dallas to extract characteristics of urban air. While the absolute values of the normal and PE concentrations of alkanes, alkenes, alkyne, and aromatics were significantly different among these urban areas, the proportions of each chemical group to the total NMHC were not so different.In Nagoya, the total normal concentration was high from November to February and low from June to August. The pattern of the seasonal variation was influenced mainly by that of alkanes. On the other hand, the total PE concentration was high from July to December and low from January to June. The pattern of the seasonal variation was influenced mainly by those of alkenes and aromatics. Particularly the normal concentration of isoprene was high from May to September because of large emission associated with activity of plants. As the results, in summer, the PE concentration of isoprene was especially high, and its contribution to the total NMHCs measured in this study was approximately 40%. The total PE concentrations were high in summer when the concentration of OH radicals is also high, suggesting that the productions of ozone and secondary organic aerosol (SOA) are likely to be promoted in summer of Nagoya.  相似文献   
152.
Ambient measurements of hydrocarbons, carbon monoxide and nitrogen oxides from three mega-cities (Beijing, Mexico City, Tokyo) are compared with similar measurements from US cities in the mid-1980s and the early 2000s. The common hydrocarbon pattern seen in all data sets suggests that emissions associated with gasoline-fueled vehicles dominate in all of these cities. This commonality suggests that it will be efficient and, ultimately, cost effective to proceed with vehicular emission controls in most emerging mega-cities, while proceeding with development of more locally appropriate air quality control strategies through emissions inventory development and ambient air monitoring. Over the three decades covered by the US data sets, the hydrocarbon emissions decreased by a significant factor (something like an order of magnitude), which is greater than suggested by emission inventories, particularly the EDGAR international inventory. The ambient hydrocarbon and CO concentrations reported for the three non-US mega-cities are higher than present US ambient concentrations, but lower than those observed in the 1980s in the US. The one exception to the preceding statement is the high concentrations of CO observed in Beijing, which apparently have a large regional contribution.  相似文献   
153.
Abstract: The objective of this study is to evaluate the effect of estrogens on fish endocrine disruption in river water and treated wastewater. Endogenous estrogen estrone (E1), 17β‐estradiol (E2), river water, and treated wastewater were used for exposure tests on male Japanese medaka. Vitellogenin induction in male medaka was regarded as the endpoint of endocrine disruption. The effective concentrations of E1 and E2 on vitellogenin induction in medaka were evaluated by breeding medaka for 14 days in tanks with various concentrations of E1 or E2. Vitellogenin induction increased with elapse of time during exposure, with higher estrogen concentrations causing greater vitellogenin induction. According to the test results, the lowest observed effect concentrations (LOECs) of E1 and E2 were estimated to be 31.6 and 5.0 ng/l, respectively; and the E2 equivalent (EEQ) LOEC value of E1 was 5.2 ng‐E2/l, derived by multiplying the relative potency of E1 by that of E2 as estimated in this study. In continuous exposure tests using river water or treated wastewater, the estrogenic activity, an index of total estrogenic potential measured by yeast screen assay and expressed as EEQ, varied widely during the exposure tests, and significant vitellogenin induction was observed after several days of high levels of estrogenic activity in water. Vitellogenin concentration tended to significantly increase if EEQ exceeded the level of 5 ng‐E2/l. The threshold value was substantially the same as the results for E1 and E2 exposure tests of medaka. Consequently, EEQ over 5 ng‐E2/l was revealed to have the potential to cause endocrine disruption of male medaka. As estrogenic activity exceeding 5 ng‐E2/l was observed in some rivers in Japan, total estrogenic potential needs to be further decreased at wastewater treatment plants to prevent fish endocrine disruption.  相似文献   
154.
Hemp bast holocellulose fiber (Cannabis sativa L. Subsp. Sativa) was oxidized by TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidation at various NaClO addition levels in water at pH 10. When carboxylate contents of the oxidized products were 1.5–1.7 mmol/g, TEMPO-oxidized cellulose nanofibrils almost completely dispersed at the individual nanofibril were obtained by mechanical disintegration of the TEMPO-oxidized hemp bast holocelluloses in water, where the nanofibrillation yields were 98–100 %. The sugar composition analysis revealed that most of hemicelluloses originally present in the hemp bast holocellulose were degraded and removed from the solid oxidized products, providing almost pure TEMPO-oxidized celluloses. X-ray diffraction patterns of all TEMPO-oxidized hemp bast holocelluloses had the same cellulose I crystal structure and similar crystallinity indices and crystal widths, indicating that carboxylate groups formed by the oxidation were selectively present on the crystalline cellulose microfibril surfaces in the holocellulose. However, the weight recovery ratios and viscosity-average degrees of polymerization of the TEMPO-oxidized hemp bast holocelluloses decreased to 69–59 % and 470–380, respectively, when their carboxylate contents increased to 1.5–1.7 mmol/g by the TEMPO-mediated oxidation. Atomic force microscopy height images showed that the nanofibril widths were 2.7–2.9 nm, and the average nanofibril lengths decreased from 590 to 400 nm as the NaClO addition level was increased from 7.5 to 12.5 mmol/g in the TEMPO-mediated oxidation.  相似文献   
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157.
Livestock manure is suitable for use as a composting material. However, various intestinal microbes, such as Escherichia coli, are significant components of such manures. Thus, it is desirable that the level of intestinal microbes, and particularly opportunistic pathogens, in compost is inspected and counted regularly. The sensitivity and specificity of detection of E. coli in compost have been improved by selective cultivation followed by colony polymerase chain reaction (PCR) using the ECO primer. Indeed, the sensitivity of this method is higher than that of DNA extraction from compost and PCR. In this study, changes in numbers of E. coli present in a field-scale composting process over time was assessed using selective cultivation and colony PCR. Numbers of ECO-positive colonies after 24 h decreased, with a concomitant rise in compost temperature. ECO-positive colonies were not detected from 33 to 48 h. However, ECO-positive colony numbers increased beginning on day 4 and continuing until day 42. Thus, it seems likely that the high temperatures reached during the composting process did not affect E. coli numbers in the final compost. Additionally, selective cultivation followed by colony PCR using specific primers is an appropriate method of determining levels of cultivable pathogens in composted materials.  相似文献   
158.
Three experiments were designed to determine the effects of SO2 concentration on two Southeastern oat varieties—Caroiee and Coker 227. The plants were grown under uniform conditions prior to and after the experimental growth period. During the 7 to 14 day experimental growth period the plants were subjected to four growth temperatures (18/14, 22/18, 26/22 and 30/26° C day/night temperatures) and exposed 2 or 4 times to specific concentrations of SO2 (from 0 to 4 ppm) for 1.5 or 3.0 hr periods. In the first two experiments, the exposure temperatures were varied (18° to 30° C). In the third design, the exposure temperatures remained constant and two exposure relative humidities (55 and 80%) were used. Injury and growth reductions were more severe in Coker 227 than in Caroiee. Root dry weight (RDW) was affected more than top dry weight (TDW). Plants were more sensitive at the higher growth temperatures. Exposure temperatures had little to variable effects. Plants were more sensitive at 80% than at 55% relative humidity. Biomass was reduced at 0.4 ppm SO2 after four 3 hr exposures and at 0.75 ppm after two 1.5 hr exposures, but growth was also increased as often. These concentrations approached the accepted threshold for adverse effects to sensitive vegetation. Foliar injury was highly correlated with growth reductions.  相似文献   
159.
Abstract

After strontium/transuranics removal by precipitation followed by cesium/technetium removal by ion exchange, the remaining low-activity waste in the Hanford River Protection Project Waste Treatment Plant is to be concentrated by evaporation before being mixed with glass formers and vitrified. To provide a technical basis to permit the waste treatment facility, a relatively organic-rich Hanford Tank 241-AN-107 waste simulant was spiked with 14 target volatile, semi-volatile, and pesticide compounds and evaporated under vacuum in a bench-scale natural circulation evaporator fitted with an industrial stack off-gas sampler at the Savannah River National Laboratory. An evaporator material balance for the target organics was calculated by combining liquid stream mass and analytical data with off-gas emissions estimates obtained using U.S. Environmental Protection Agency (EPA) SW-846 Methods. Volatile and light semi-volatile organic compounds (<220 °C BP, >1 mm Hg vapor pressure) in the waste simulant were found to largely exit through the condenser vent, while heavier semi-volatiles and pesticides generally remain in the evaporator concentrate. An OLI Environmental Simulation Program (licensed by OLI Systems, Inc.) evaporator model successfully predicted operating conditions and the experimental distribution of the fed target organics exiting in the concentrate, condensate, and off-gas streams, with the exception of a few semi-volatile and pesticide compounds. Comparison with Henry's Law predictions suggests the OLI Environmental Simulation Program model is constrained by available literature data.  相似文献   
160.
Sun-blocking agents including eight UV filters (UVF) and 10 UV light stabilizers (UVLS) were measured in water and sediment collected from 22 rivers, four sewage treatment plant effluents (STPE) and three lakes in Japan. Total sun blocking agents levels ranged from N.D. to 4928 ng/L and from 2.0 to 3422 μg/kg dry wt in surface water and in sediment, respectively. Benzyl salicylate, benzophenone-3, 2-ethyl hexyl-4-methoxycinnamte (EHMC) and octyl salicylate were dominant in surface water receiving wastewater effluents and STPE, although UV-328, benzophenone and EHMC were dominant in other surface water except background sites. Three UVF and nine UVLS were observed from all sediment and their compositions showed similar patterns with UV-328 and UV-234 as the most prevalent compounds. Homosalate, octocrylene, UV-326, UV-327, UV-328 and UV-234 were significantly correlated with Galaxolide® in sediments. Concentrations of UV-327 and UV-328 also had strong correlation between those of UV-326 in sediment.  相似文献   
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