Brominated flame retardants (BFRs) were investigated in juvenile common sole from nursery zones situated along the French coast in 2007, 2008 and 2009. Extensive identification was performed with regard to PBDEs, novel BFRs 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) and decabromodiphenylethane (DBDPE), and other non-PBDE BFRs, namely, hexabromobenzene (HBB) and 2,2′,4,4′,5,5′-hexabromobiphenyl (BB-153). Polybrominated diphenyl ether (PBDE) concentrations (Σ 14 congeners) ranged from 0.01 ng/g to 0.16 ng/g wet weight (ww) in muscle, and 0.07 ng/g to 2.8 ng/g ww in liver. Concentrations were in the lower range of those reported in the literature in other European locations. Lower PBDE concentrations, condition indices and lipid contents were observed in the Seine estuary in 2009, possibly in relation to a lower water flow. The PBDE patterns and ratios we observed suggested that juvenile sole have a relative high metabolic degradation capacity. Non-PBDE BFRs were detected at lower levels than PBDEs, i.e., within the < method detection limit - 0.005 ng/g ww range in muscle, and < method detection limit - 0.2 ng/g ww range in liver. The data obtained is of particular interest for the future monitoring of these compounds in the environment. 相似文献
This paper presents a comprehensive review of the mechanisms responsible for the transfer of atmospheric particulate deposition and soil particulate re-suspension onto vegetation. The nature of atmospheric aerosols and dry/wet particulate deposition are reviewed, together with information from the literature on radionuclides as tracers of the air particle/soil particle to vegetation transfer processes. Information from these fields is used to make inferences about the potential significance of these pathways in supplying particle-bound semi-volatile organic chemicals (e.g. polycyclic aromatic hydrocarbons, polychlorinated dibenzo-p-dioxins and dibenzofurans, polychlorinated biphenyls) to vegetation. Retention of compounds on particles brought to the above-ground plant surfaces is discussed. In the absence of definitive field/experimental studies, calculations are made drawing on the literature data to estimate the contributions of atmospheric and soil particle-bound organic contaminants to the plant concentration. These show that depending on the site-specific, species-specific and compound-specific scenarios considered, particulate-bound inputs may be negligible or may dominate the supply of organic contaminants to the above-ground portion of plants. However, field/experimental studies and direct measurements are needed to provide reliable quantitative data on this topic. 相似文献
What are the effects of flame behavior of a number of fires burning in close proximity to one another? The results of measurements of burning rates, heat feedback, flame height, and flame trailing are reported for fires involving liquid pools. 相似文献
The purpose of this paper is to present a formulation of a curved thin-walled box beam finite element having a variable cross-section with at least one vertical axis of symmetry.
To allow for the effects of warping and distortion, three degrees of freedom have been included in the formulation. These degrees of freedom have been designated as the rate of change of twisting angle, the distortional angle of the cross-section, and the rate of change of distortional angle. The effect of shear lag has also been included.
The element may be used for the elastic analysis of a variety of thin-walled structures and in particular for the preliminary analysis of box bridge decks where a three-dimensional analysis may be unnecessary. The accuracy of the element has been demonstrated by comparison of the results obtained with known results from other methods for some examples. 相似文献
Although it is extensively researched, flocculation in the water-treatment industry lacks a design procedure to assess accurately the performance of the different types of agitator impeller which are available. New high-efficiency, hydrofoil-type impellers offer substantial potential for flocculation duties in many areas, provided that they are applied correctly. This paper highlights the importance of the 'velocity gradient'and the distribution of shear within the agitation system. The objective of the paper is to help engineers to evaluate different types of proprietary impeller designs, using various techniques to examine the shear distribution applied to the system. 相似文献