Documents disponibles écrits par cet auteur

Effect of air release height on the formation of sediment thermals in water / Bing Zhao in Journal of hydraulic research, Vol. 50 N° 5 (Septembre/Octobre 2012) 

Public ISBD [article]  in Journal of hydraulic research > Vol. 50 N° 5 (Septembre/Octobre 2012) . - pp. 532-540 Titre : Effect of air release height on the formation of sediment thermals in water Type de document : texte imprimé Auteurs : Bing Zhao, Auteur ; Adrian W.K. Law, Auteur ; Adams, E. Eric, Auteur Année de publication : 2012 Article en page(s) : pp. 532-540 Note générale : Hydraulique Langues : Anglais (eng) Mots-clés : Dredged  material  Miscible  thermal  Particle  cloud  Sediment  disposal  Virtual  origin Résumé : In this study, the underwater behaviour of sediment thermals (i.e. sediment clouds in the self-preserving phase), formed by releasing dry sediments instantaneously from various heights above water, was investigated experimentally. Measurements show that as the air release height increases, the initial acceleration phase of the sediment cloud in water is shortened, while the growth rate during its self-preserving phase remains constant. Therefore, the effect of air release height can be accounted for by utilizing a new concept of simultaneous virtual distance and time origins, which are found to be related to an impact densimetric Froude number (defined as the ratio between the impact velocity of the sediment cluster at the water surface and the characteristic velocity of the sediment thermal generated by buoyancy excess). Based on the measurement results, a semi-empirical model is utilized to predict the growth and penetration behaviours of the sediment thermal. Predictions by the model with the virtual origins correction match well with the experimental data. ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2012.715094 [article] Effect of air release height on the formation of sediment thermals in water [texte imprimé] / Bing Zhao, Auteur ; Adrian W.K. Law, Auteur ; Adams, E. Eric, Auteur . - 2012 . - pp. 532-540. Hydraulique Langues : Anglais (eng) in Journal of hydraulic research > Vol. 50 N° 5 (Septembre/Octobre 2012) . - pp. 532-540 Mots-clés : Dredged  material  Miscible  thermal  Particle  cloud  Sediment  disposal  Virtual  origin Résumé : In this study, the underwater behaviour of sediment thermals (i.e. sediment clouds in the self-preserving phase), formed by releasing dry sediments instantaneously from various heights above water, was investigated experimentally. Measurements show that as the air release height increases, the initial acceleration phase of the sediment cloud in water is shortened, while the growth rate during its self-preserving phase remains constant. Therefore, the effect of air release height can be accounted for by utilizing a new concept of simultaneous virtual distance and time origins, which are found to be related to an impact densimetric Froude number (defined as the ratio between the impact velocity of the sediment cluster at the water surface and the characteristic velocity of the sediment thermal generated by buoyancy excess). Based on the measurement results, a semi-empirical model is utilized to predict the growth and penetration behaviours of the sediment thermal. Predictions by the model with the virtual origins correction match well with the experimental data. ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2012.715094

Rapid In Situ Transesterification of Sunflower Oil / Jianli Zeng in Industrial & engineering chemistry research, Vol. 48 N°2 (Janvier 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N°2 (Janvier 2009) . - p. 850–856 Titre : Rapid In Situ Transesterification of Sunflower Oil Type de document : texte imprimé Auteurs : Jianli Zeng, Auteur ; Xiaodong Wang, Auteur ; Bing Zhao, Auteur ; Jingcan Sun, Auteur ; Yuchun Wang, Auteur Année de publication : 2009 Article en page(s) : p. 850–856 Note générale : chemical engineering Langues : Anglais (eng) Mots-clés : Sunflower  Oil--  Transesterification Résumé : A rapid in situ transesterification process of sunflower oil with methanol assisted by diethoxymethane (DEM) is described in this article. DEM served as both extraction solvent and reaction promoter in the process. The effects of moisture content of sunflower seeds, catalyst category, molar ratio of catalyst/oil, molar ratio of methanol/oil, molar ratio of DEM/oil, reaction time, reaction temperature, and agitation speed on the in situ transesterification were investigated. The most important factors which influenced the crude biodiesel yield, free fatty acid (FFA) content, and fatty acid methyl ester (FAME) purity were the molar ratio of DEM/oil, molar ratio of catalyst/oil, and molar ratio of catalyst/oil, respectively. An empirical model of the rapid in situ transesterification process was established and used to determine the optimal reaction conditions. When the in situ transesterification was carried out at the molar ratio of catalyst/oil of 0.5:1, the molar ratio of methanol/oil of 101.39:1, the molar ratio of DEM/oil of 57.85:1, the agitation speed of 150 rpm, and reaction temperature of 20 °C, a product containing 97.7% FAME and 0.74% FFA was obtained within 13 min. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8008956 [article] Rapid In Situ Transesterification of Sunflower Oil [texte imprimé] / Jianli Zeng, Auteur ; Xiaodong Wang, Auteur ; Bing Zhao, Auteur ; Jingcan Sun, Auteur ; Yuchun Wang, Auteur . - 2009 . - p. 850–856. chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°2 (Janvier 2009) . - p. 850–856 Mots-clés : Sunflower  Oil--  Transesterification Résumé : A rapid in situ transesterification process of sunflower oil with methanol assisted by diethoxymethane (DEM) is described in this article. DEM served as both extraction solvent and reaction promoter in the process. The effects of moisture content of sunflower seeds, catalyst category, molar ratio of catalyst/oil, molar ratio of methanol/oil, molar ratio of DEM/oil, reaction time, reaction temperature, and agitation speed on the in situ transesterification were investigated. The most important factors which influenced the crude biodiesel yield, free fatty acid (FFA) content, and fatty acid methyl ester (FAME) purity were the molar ratio of DEM/oil, molar ratio of catalyst/oil, and molar ratio of catalyst/oil, respectively. An empirical model of the rapid in situ transesterification process was established and used to determine the optimal reaction conditions. When the in situ transesterification was carried out at the molar ratio of catalyst/oil of 0.5:1, the molar ratio of methanol/oil of 101.39:1, the molar ratio of DEM/oil of 57.85:1, the agitation speed of 150 rpm, and reaction temperature of 20 °C, a product containing 97.7% FAME and 0.74% FFA was obtained within 13 min. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8008956