Multiwalled carbon nanotubes have been used for the first time as solid-phase extraction sorbents for the extraction of five N-methylcarbamate insecticides (i.e., carbaryl, carbofuran, aminocarb, methiocarb, and zectran) from different surface water samples. An effective and sensitive method was developed by combining solid-phase extraction and liquid chromatography-electrospray ionization-mass spectrometry detection. Important parameters influencing the extraction efficiency such as kind and volume of elute, volume of water samples, and adsorbent mass were optimized. Under the optimized extraction conditions, good linearity was obtained for all carbamates (r 2 [ 0.995) over the range of 0.005-1 mg L -1 . The limits of detection and quantification were 0.01-0.05 and 0.08-0.2 lg L -1 , respectively. The optimized solid-phase extraction procedure was compared in terms of adsorption capacity to C18 silica and activated carbon. The adsorption capacity of multiwalled carbon nanotubes was larger than activated carbon. The proposed method was successfully applied to the analysis of tap and surface waters, and mean recoveries for five carbamates were from 92.2 to 103.9 % with relative standard deviation between 0.4 and 7.0 %.

International audienceDigital watermarking can be used as data hiding technique to interleave cover content with auxiliary information before transmitting and storing applications. While image and video watermarking has been widely studied, much less attention has been paid to its application in 3D mesh models. This is principally due to their intrinsic irregular sampling nature. This paper proposes a high-capacity watermarking scheme for the purpose of inserting meta-data into 3D triangle meshes. Our proposal can be applied to meshes with arbitrary topology by using irregular wavelet-based analysis. The watermark is embedded in an appropriate resolution level by quantizing the norms of wavelet coefficient vectors. To ensure robustness to similarity transformation, a robust synchronization (indexing) mechanism is performed on the 3D model after irregular wavelet analysis. Experimental results show that our watermarking framework is robust to common geometric attacks and can provide relatively high data embedding rate whereas keep a relative lower distortion

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