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Misssaoui I.,Tunis el Manar University | Lachiri Z.,Institute National Des Science Appliquees Et Of Technology Insat
2013 World Congress on Computer and Information Technology, WCCIT 2013 | Year: 2013

This paper presents a blind speech separation (BSS) method based on Degenerate Unmixing Estimation Technique (DUET) and binary time-frequency masking approach. Firstly, the speech signals are extracts from the anechoic speech mixtures using the DUET algorithm. Then, a temporal smoothing procedure is applied in the cepstral domain to the spectral masks. The latter are estimated from the obtained signals. The smoothing procedure is capable of reducing musical noise artifacts in the separated signal which is often generated by the time-frequency binary mask based BSS approaches. Experimental results indicate that the proposed method provides high interference suppression and musical noise reduction. © 2013 IEEE.

Besbes N.,Institute National Des Science Et Technologies Of La Mer Instm | Fattouch S.,Institute National Des Science Appliquees Et Of Technology Insat | Sadok S.,Institute National Des Science Et Technologies Of La Mer Instm
Food Control | Year: 2012

Correct identification of fish species including their origin requires a compilation of recognized material to verify the conformity of the product with the labelling requirement. Sardine is among the internationally disputed example of species identification conflicts, with the lack of genetic reference material at the Southern part of the Mediterranean. Therefore a method was developed to discriminate between Tunisian small pelagic fish: Sardina pilchardus, Sardinella aurita and Engraulis encrasicolus. DNA extraction from fresh fish and from 12 canned sardine and 2 anchovy-type products, was followed by a PCR method that specifically amplifies a 252 bp fragment of the cytochrome b gene. The new sequences which were deposited in the NCBI GenBank, were searched against a nucleotide sequence database (GenBank) and phylogenetically analyzed with the MEGA software. Multiple alignments of 3 analyzed reference samples belonging to Clupeomorpha species was performed versus the canned samples. Low intraspecific variability was observed for canned anchovy and sardine (<0.05), whereas mean interspecific variability was 0.23. A phylogenetic tree was constructed, and the calculated bootstrap values (BP, 71-100%) were used as indicators of the correct assignment of unknown canned samples to reference species. Postamplification digestion with HaeIII and ALuI restriction enzymes, yielded specific profiles that enabled anchovy to be distinguished from either of the sardine species. This PCR-RFLP was found to be reliable for species identification of canned fish products. © 2011 Elsevier Ltd.

Kasmi M.,University of Carthage | Chatti A.,University of Carthage | Hamdi M.,Institute National Des Science Appliquees Et Of Technology Insat | Trabelsi I.,University of Carthage
Clean Technologies and Environmental Policy | Year: 2016

Soft drink industries suffer inadequate handling of their product losses generally considered as wastes. Those products contribute to the wastewater organic load augmentation and cause fastidious environmental impact. In this study, an industrial scale bioconversion process based on multistage fermentation was proposed to treat and reuse soft drink factories’ high-loaded effluents for valuable components production. An upstream segregation of non-consumed beverage was performed to reduce the organic load of the soft drink wastewater. Beverage characterization revealed an important sugar content. Such an organic compound is undoubtedly responsible of the high organic load of soft drink wastewater. Thus, the bioconversion of the sugar content of soft drink waste to single-cell proteins was proposed as a solution to reduce wastewater polluting load. Soft drink wastewater including rejected and returned products was tested to be used as a substrate for yeast biomass production using a commercial yeast strain of Saccharomyces cerevisiae. The effect of nutrient supplementation and the initial sugar concentration effect in culture media on the biomass production were investigated using batch and fed-batch process. Results indicated that supplementation is necessary for successful fermentation. Juices and nectars gave better sugar-biomass conversion yields (0.38–0.45 g g−1). Depletion of the sugar contained in the soft drinks exceeded 96 % for all fermented media. Fed-batch culture revealed a biomass concentration improvement reaching 9.16 g L−1 compared to batch biomass concentration resulting from batch cultures (5.2 g L−1). The proposed process was shown to enable beverage industries to reduce water pollution generation through an on-site segregation procedure and a storage system to valorize product losses as source medium for single-cell protein production. © 2016 Springer-Verlag Berlin Heidelberg

Lazrag H.,National Engineering School of Tunis | Naceur M.S.,National Engineering School of Tunis | Naceur M.S.,Institute National Des Science Appliquees Et Of Technology Insat
International Journal of Biomedical Imaging | Year: 2012

Intravascular ultrasound (IVUS) imaging is a catheter-based medical methodology establishing itself as a useful modality for studying atherosclerosis. The detection of lumen and media-adventitia boundaries in IVUS images constitutes an essential step towards the reliable quantitative diagnosis of atherosclerosis. In this paper, a novel scheme is proposed to automatically detect lumen and media-adventitia borders. This segmentation method is based on the level-set model and the contourlet multiresolution analysis. The contourlet transform decomposes the original image into low-pass components and band-pass directional bands. The circular hough transform (CHT) is adopted in low-pass bands to yield the initial lumen and media-adventitia contours. The anisotropic diffusion filtering is then used in band-pass subbands to suppress noise and preserve arterial edges. Finally, the curve evolution in the level-set functions is used to obtain final contours. The proposed method is experimentally evaluated via 20 simulated images and 30 real images from human coronary arteries. It is demonstrated that the mean distance error and the relative mean distance error have increased by 5.30 pixels and 7.45%, respectively, as compared with those of a recently traditional level-set model. These results reveal that the proposed method can automatically and accurately extract two vascular boundaries. Copyright © 2012 Hassen Lazrag and Med Saber Naceur.

Aissaoui N.,University Pierre and Marie Curie | Aissaoui N.,CNRS Surface Science Lab | Aissaoui N.,Institute National Des Science Appliquees Et Of Technology Insat | Bergaoui L.,Institute National Des Science Appliquees Et Of Technology Insat | And 6 more authors.
Langmuir | Year: 2012

In this work the mechanism of (3-aminopropyl)triethoxysilane (APTES) interaction with silicon surfaces is investigated at the molecular level. We studied the influence of experimental parameters such as time, temperature, and concentration on the quality of the APTES layer in terms of chemical properties, morphology, and stability in aqueous medium. This was achieved using a highly sensitive IR mode recently developed, grazing angle attenuated total reflection (GA-ATR). This technique provides structural information on the formed APTES layer. The topography of this layer was investigated by atomic force microscopy in aqueous medium. The hydrophilicity was also studied using contact angle measurement. Combining these techniques enables discussion of the mechanism of silane grafting. Considerable differences were observed depending on the reaction temperature, room temperature or 90 °C. The data suggest the presence of two adsorption sites with different affinities on the oxidized silicon layer. This also allows the optimal parameters to be established to obtain an ordered and stable silane layer. The adsorption of proteins on the APTES layer was achieved and monitored using in situ quartz crystal microbalance with dissipation monitoring and ex situ GA-ATR analyses. © 2011 American Chemical Society.

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