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Analytical Froude number solution for reservoir density inflows / Yuanya Li in Journal of hydraulic research, Vol. 49 N° 5 (Septembre/Octobre 2011) 

Public ISBD [article]  in Journal of hydraulic research > Vol. 49 N° 5 (Septembre/Octobre 2011) . - pp. 693-696 Titre : Analytical Froude number solution for reservoir density inflows Type de document : texte imprimé Auteurs : Yuanya Li, Auteur ; Junhua Zhang, Auteur ; Huaibao Ma, Auteur Année de publication : 2011 Article en page(s) : pp. 693-696 Note générale : Hydraulique Langues : Anglais (eng) Mots-clés : Energy  balance  Froude  number  Gravity  current  Reservoir  sedimentation  Turbidity  current Index. décimale : 627 Ingénierie des cours d'eau naturels, des ports, des rades et des cotes. Installations de navigation, de dragage, de récupération et de sauvetage. Barrages et centrales électriques hydrauliques Résumé : This research presents a theoretical Froude number model at the incipient plunging point for a gravity current advancing into a sloping ambient reservoir. The analysis is based on the balance of potential energy, kinetic energy and energy losses. The Froude number at the incipient plunging point attracted attention in recent years. There are two opinions: either the Froude number is considered a constant, whereas others find it as variable in a wide range, depending on the bottom slope and the sediment concentration. The theoretical solution presented herein resolves the problem by stating that the Froude number is the function of bottom slope, relative thickness of the density current and the friction coefficient. Moreover, this theoretical analysis unifies all previous researches culminating in a general solution of the problem. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.593905 [article] Analytical Froude number solution for reservoir density inflows [texte imprimé] / Yuanya Li, Auteur ; Junhua Zhang, Auteur ; Huaibao Ma, Auteur . - 2011 . - pp. 693-696. Hydraulique Langues : Anglais (eng) in Journal of hydraulic research > Vol. 49 N° 5 (Septembre/Octobre 2011) . - pp. 693-696 Mots-clés : Energy  balance  Froude  number  Gravity  current  Reservoir  sedimentation  Turbidity  current Index. décimale : 627 Ingénierie des cours d'eau naturels, des ports, des rades et des cotes. Installations de navigation, de dragage, de récupération et de sauvetage. Barrages et centrales électriques hydrauliques Résumé : This research presents a theoretical Froude number model at the incipient plunging point for a gravity current advancing into a sloping ambient reservoir. The analysis is based on the balance of potential energy, kinetic energy and energy losses. The Froude number at the incipient plunging point attracted attention in recent years. There are two opinions: either the Froude number is considered a constant, whereas others find it as variable in a wide range, depending on the bottom slope and the sediment concentration. The theoretical solution presented herein resolves the problem by stating that the Froude number is the function of bottom slope, relative thickness of the density current and the friction coefficient. Moreover, this theoretical analysis unifies all previous researches culminating in a general solution of the problem. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.593905

Variables affecting biodiesel production from zanthoxylum bungeanum seed oil with high free fatty acids / Junhua Zhang in Industrial & engineering chemistry research, Vol. 51 N° 9 (Mars 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 9 (Mars 2012) . - pp. 3525-3530 Titre : Variables affecting biodiesel production from zanthoxylum bungeanum seed oil with high free fatty acids Type de document : texte imprimé Auteurs : Junhua Zhang, Auteur ; Zhang, Lei, Auteur ; Lili Jia, Auteur Année de publication : 2012 Article en page(s) : pp. 3525-3530 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Production  Biodiesel Résumé : The Zanthoxylum bungeanum seed oil (ZSO) having high free fatty acids was successfully transformed into biodiesel by acid-catalyzed esterification and alkali-catalyzed transesterification and high conversion to biodiesel was obtained in a short time compared to acid-catalyzed transesterification. Methanol-to-oil molar ratio, catalyst amount, and reaction time were found to clearly affect the ferric sulfate-catalyzed esterification of ZSO. The acid value of ZSO was reduced to less than 2 mg of KOH/g with a methanol-to-oil molar ratio of 16:1, catalyst amount of 2%, and reaction time of 3 h, following transesterification using an alkaline catalyst. The conversion to biodiesel by potassium hydroxide-catalyzed transesterification was achieved above 98% under optimum conditions: a methanol-to-oil molar ratio of 6:1, catalyst amount of 1.5%, reaction time of 60 min, and reaction temperature of 60 °C. The biodiesel production process was also confirmed by 1H NMR and FTIR. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200306w [article] Variables affecting biodiesel production from zanthoxylum bungeanum seed oil with high free fatty acids [texte imprimé] / Junhua Zhang, Auteur ; Zhang, Lei, Auteur ; Lili Jia, Auteur . - 2012 . - pp. 3525-3530. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 9 (Mars 2012) . - pp. 3525-3530 Mots-clés : Production  Biodiesel Résumé : The Zanthoxylum bungeanum seed oil (ZSO) having high free fatty acids was successfully transformed into biodiesel by acid-catalyzed esterification and alkali-catalyzed transesterification and high conversion to biodiesel was obtained in a short time compared to acid-catalyzed transesterification. Methanol-to-oil molar ratio, catalyst amount, and reaction time were found to clearly affect the ferric sulfate-catalyzed esterification of ZSO. The acid value of ZSO was reduced to less than 2 mg of KOH/g with a methanol-to-oil molar ratio of 16:1, catalyst amount of 2%, and reaction time of 3 h, following transesterification using an alkaline catalyst. The conversion to biodiesel by potassium hydroxide-catalyzed transesterification was achieved above 98% under optimum conditions: a methanol-to-oil molar ratio of 6:1, catalyst amount of 1.5%, reaction time of 60 min, and reaction temperature of 60 °C. The biodiesel production process was also confirmed by 1H NMR and FTIR. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200306w