Les Inscriptions à la Bibliothèque sont ouvertes en
ligne via le site: https://biblio.enp.edu.dz
Les Réinscriptions se font à :
• La Bibliothèque Annexe pour les étudiants en
2ème Année CPST
• La Bibliothèque Centrale pour les étudiants en Spécialités
A partir de cette page vous pouvez :
Retourner au premier écran avec les recherches... |
Détail de l'auteur
Auteur Chen, Li
Documents disponibles écrits par cet auteur
Affiner la rechercheApplication of surface-based bed load transport équations to a desert gravel-bed stream / Duan, Jennifer G. in Journal of hydraulic research, Vol. 44 N°5 (2006)
[article]
in Journal of hydraulic research > Vol. 44 N°5 (2006) . - 624-630 p.
Titre : Application of surface-based bed load transport équations to a desert gravel-bed stream Titre original : Application des équations de transport de sédiamnts à un cours d'eau de désert avec un lit de gravier Type de document : texte imprimé Auteurs : Duan, Jennifer G., Auteur ; Chen, Li, Auteur ; Scott, Steve, Auteur Article en page(s) : 624-630 p. Note générale : Hydraulique Langues : Anglais (eng) Mots-clés : Sediment transport Bed load Fractional transport rate Gravel-bed river Deset Urban stream Transport de sédiment Charge de lit Taux partiel de transport Fleuve de lit de gravier Jet urbain 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 : Bed load measurements during low flow in a desert gravel-bed stream, Las Vegas Wash, were used to evaluate fractional bed load transport equations. Since the stream is an urban perennial channel that conveys primarily treated waste effluent, bed load transport is limited by the supply of transportable bed material. The Parker, Wilcock and Crowe, and Wu et al. surface-based fractional bed load transport equations were evaluated against the field data. The ratio between the calculated and measured bed load transport rate (C/O) as well as the data correlation coefficient with respect to each formula were calculated to judge the applicability of these equations to this field dataset. Comparisons showed that both the Parker and Wu et al. equations satisfactorily predicted the transport rate, while the Wilcock and Crowe equation has a larger scatter. The apparent success of Parker and Wu et al. equations can be attributed to two factors: a hiding function based on physical mechanism of the particle hiding and exposure, and the empirical coefficients calibrated using field data sources. The study results indicate that these two fractional bed load transport equations derived for perennial streams in wet regions are applicable to the field data collected at this arid region channel.
Enfoncer les mesures de charge pendant le débit faible dans un jet de lit de gravier de désert, lavage de Las Vegas, ont été employés pour évaluer des équations partielles de transport de charge de lit. Puisque le jet est un canal éternel urbain qui transporte principalement l'effluent de rebut traité, le transport de charge de lit est limité par l'approvisionnement en matériel transportable de lit. Parker, Wilcock et Crowe, et Wu et autres. la surface a basé des équations partielles de transport de charge de lit ont été évaluées contre les données de champ. Le rapport entre le taux calculé et mesuré de transport de charge de lit (C/O) aussi bien que le coefficient de corrélation de données en ce qui concerne chaque formule ont été calculés pour juger l'applicabilité de ces équations à cet ensemble de données de champ. Les comparaisons ont prouvé que Parker et Wu et autres. les équations ont d'une manière satisfaisante prévu le taux de transport, alors que l'équation de Wilcock et de Crowe a un plus grand éparpillement. Le succès apparent de Parker et de Wu et autres. des équations peuvent être attribuées à deux facteurs : une fonction se cachante basée sur le mécanisme physique de se cacher et d'exposition des particules, et les coefficients empiriques ont calibré en utilisant des points d'émission de champ. Les résultats d'étude indiquent que ces deux équations partielles de transport de charge de lit dérivées pour les jets éternels dans des régions humides sont applicables aux données de champ rassemblées à ce canal aride de région.DEWEY : 627 ISSN : 0022-1686 RAMEAU : Jets d'eau En ligne : gduan@email.arizona.ed [article] Application of surface-based bed load transport équations to a desert gravel-bed stream = Application des équations de transport de sédiamnts à un cours d'eau de désert avec un lit de gravier [texte imprimé] / Duan, Jennifer G., Auteur ; Chen, Li, Auteur ; Scott, Steve, Auteur . - 624-630 p.
Hydraulique
Langues : Anglais (eng)
in Journal of hydraulic research > Vol. 44 N°5 (2006) . - 624-630 p.
Mots-clés : Sediment transport Bed load Fractional transport rate Gravel-bed river Deset Urban stream Transport de sédiment Charge de lit Taux partiel de transport Fleuve de lit de gravier Jet urbain 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 : Bed load measurements during low flow in a desert gravel-bed stream, Las Vegas Wash, were used to evaluate fractional bed load transport equations. Since the stream is an urban perennial channel that conveys primarily treated waste effluent, bed load transport is limited by the supply of transportable bed material. The Parker, Wilcock and Crowe, and Wu et al. surface-based fractional bed load transport equations were evaluated against the field data. The ratio between the calculated and measured bed load transport rate (C/O) as well as the data correlation coefficient with respect to each formula were calculated to judge the applicability of these equations to this field dataset. Comparisons showed that both the Parker and Wu et al. equations satisfactorily predicted the transport rate, while the Wilcock and Crowe equation has a larger scatter. The apparent success of Parker and Wu et al. equations can be attributed to two factors: a hiding function based on physical mechanism of the particle hiding and exposure, and the empirical coefficients calibrated using field data sources. The study results indicate that these two fractional bed load transport equations derived for perennial streams in wet regions are applicable to the field data collected at this arid region channel.
Enfoncer les mesures de charge pendant le débit faible dans un jet de lit de gravier de désert, lavage de Las Vegas, ont été employés pour évaluer des équations partielles de transport de charge de lit. Puisque le jet est un canal éternel urbain qui transporte principalement l'effluent de rebut traité, le transport de charge de lit est limité par l'approvisionnement en matériel transportable de lit. Parker, Wilcock et Crowe, et Wu et autres. la surface a basé des équations partielles de transport de charge de lit ont été évaluées contre les données de champ. Le rapport entre le taux calculé et mesuré de transport de charge de lit (C/O) aussi bien que le coefficient de corrélation de données en ce qui concerne chaque formule ont été calculés pour juger l'applicabilité de ces équations à cet ensemble de données de champ. Les comparaisons ont prouvé que Parker et Wu et autres. les équations ont d'une manière satisfaisante prévu le taux de transport, alors que l'équation de Wilcock et de Crowe a un plus grand éparpillement. Le succès apparent de Parker et de Wu et autres. des équations peuvent être attribuées à deux facteurs : une fonction se cachante basée sur le mécanisme physique de se cacher et d'exposition des particules, et les coefficients empiriques ont calibré en utilisant des points d'émission de champ. Les résultats d'étude indiquent que ces deux équations partielles de transport de charge de lit dérivées pour les jets éternels dans des régions humides sont applicables aux données de champ rassemblées à ce canal aride de région.DEWEY : 627 ISSN : 0022-1686 RAMEAU : Jets d'eau En ligne : gduan@email.arizona.ed Mechanical analysis for emergent vegetation in flowing fluids / Chen, Li in Journal of hydraulic research, Vol. 49 N° 6 (Novembre/Décembre 2011)
[article]
in Journal of hydraulic research > Vol. 49 N° 6 (Novembre/Décembre 2011) . - pp. 766-774
Titre : Mechanical analysis for emergent vegetation in flowing fluids Type de document : texte imprimé Auteurs : Chen, Li, Auteur ; Stone, Mark C., Auteur ; Kumud Acharya, Auteur Année de publication : 2012 Article en page(s) : pp. 766-774 Note générale : Hydraulique Langues : Anglais (eng) Mots-clés : Drag force Ecohydraulics Hydraulic roughness Stress Vegetation bending 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 : Vegetation plays an important role in stream processes and management efforts. However, the description of mechanical behaviours of vegetation–fluid interaction requires an improved understanding of the underlying physics and of the methods used for investigating this interaction. The objective of this research was to develop a method for describing vegetation mechanics in flowing fluids. This was accomplished by outlining methods for describing vegetation responses to flow under rigid and bending conditions for simple vegetation elements. The results of the theoretical analyses provide insight into influences of vegetation biomechanical properties to force distributions, bending behaviour, and potential vegetation rupture locations and conditions. The approach can be used to estimate hydraulic conditions for vegetation failure and flow resistance caused by vegetation, especially for flexible species. Although the techniques developed here are based on simplifying assumptions, the present analysis provides a foundation for future development for submerged vegetation and complex vegetation clusters.
DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.621359 [article] Mechanical analysis for emergent vegetation in flowing fluids [texte imprimé] / Chen, Li, Auteur ; Stone, Mark C., Auteur ; Kumud Acharya, Auteur . - 2012 . - pp. 766-774.
Hydraulique
Langues : Anglais (eng)
in Journal of hydraulic research > Vol. 49 N° 6 (Novembre/Décembre 2011) . - pp. 766-774
Mots-clés : Drag force Ecohydraulics Hydraulic roughness Stress Vegetation bending 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 : Vegetation plays an important role in stream processes and management efforts. However, the description of mechanical behaviours of vegetation–fluid interaction requires an improved understanding of the underlying physics and of the methods used for investigating this interaction. The objective of this research was to develop a method for describing vegetation mechanics in flowing fluids. This was accomplished by outlining methods for describing vegetation responses to flow under rigid and bending conditions for simple vegetation elements. The results of the theoretical analyses provide insight into influences of vegetation biomechanical properties to force distributions, bending behaviour, and potential vegetation rupture locations and conditions. The approach can be used to estimate hydraulic conditions for vegetation failure and flow resistance caused by vegetation, especially for flexible species. Although the techniques developed here are based on simplifying assumptions, the present analysis provides a foundation for future development for submerged vegetation and complex vegetation clusters.
DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.621359 Modified resin coalescer for oil-in-water emulsion treatment / Yan Bo Zhou in Industrial & engineering chemistry research, Vol. 48 N°3 (Février 2009)
[article]
in Industrial & engineering chemistry research > Vol. 48 N°3 (Février 2009) . - p. 1660–1664
Titre : Modified resin coalescer for oil-in-water emulsion treatment : effect of operating conditions on oil removal performance Type de document : texte imprimé Auteurs : Yan Bo Zhou, Auteur ; Chen, Li, Auteur ; Xiao Meng Hu, Auteur Année de publication : 2009 Article en page(s) : p. 1660–1664 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Resin Oil Coalescence material Résumé :
The application of modified resin as a filter medium treating the anionic surfactant stabilized oil-in-water emulsion was investigated. In this study, emulsion breaking was accelerated by the grafting cetyltrimethylammonium bromide on polystyrene resin, so the need for expensive specific chemicals was eliminated. The results indicated that, as a new type of coalescence material, the modified resin has incomparable advantages over polypropylene, ceramic, and activated carbon. A series of experiments were performed to evaluate the effect of flow velocity, bed height, oil concentration, temperature, and pH value on the oil removal performance of the modified resin coalescer. More than 80% of emulsified oil was removed under optimal operating conditions: flow velocity 60-180 mL/h, bed height 20-40 cm, temperature 20-60 °C, and pH value 2-10. The results further indicated that modified resin bed coalescer is feasible to be used in the treatment of oil-in-water emulsion due to integration of both advantages of chemical demulsification and coalescence process.En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8012242 [article] Modified resin coalescer for oil-in-water emulsion treatment : effect of operating conditions on oil removal performance [texte imprimé] / Yan Bo Zhou, Auteur ; Chen, Li, Auteur ; Xiao Meng Hu, Auteur . - 2009 . - p. 1660–1664.
Chemical engineering
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 48 N°3 (Février 2009) . - p. 1660–1664
Mots-clés : Resin Oil Coalescence material Résumé :
The application of modified resin as a filter medium treating the anionic surfactant stabilized oil-in-water emulsion was investigated. In this study, emulsion breaking was accelerated by the grafting cetyltrimethylammonium bromide on polystyrene resin, so the need for expensive specific chemicals was eliminated. The results indicated that, as a new type of coalescence material, the modified resin has incomparable advantages over polypropylene, ceramic, and activated carbon. A series of experiments were performed to evaluate the effect of flow velocity, bed height, oil concentration, temperature, and pH value on the oil removal performance of the modified resin coalescer. More than 80% of emulsified oil was removed under optimal operating conditions: flow velocity 60-180 mL/h, bed height 20-40 cm, temperature 20-60 °C, and pH value 2-10. The results further indicated that modified resin bed coalescer is feasible to be used in the treatment of oil-in-water emulsion due to integration of both advantages of chemical demulsification and coalescence process.En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8012242 Novel inherently flame-retardant poly(trimethylene terephthalate) copolyester with the phosphorus-containing linking pendent group / Hong-Bing Chen in Industrial & engineering chemistry research, Vol. 49 N° 15 (Août 2010)
[article]
in Industrial & engineering chemistry research > Vol. 49 N° 15 (Août 2010) . - pp 7052–7059
Titre : Novel inherently flame-retardant poly(trimethylene terephthalate) copolyester with the phosphorus-containing linking pendent group Type de document : texte imprimé Auteurs : Hong-Bing Chen, Auteur ; Yi Zhang, Auteur ; Chen, Li, Auteur Année de publication : 2010 Article en page(s) : pp 7052–7059 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Copolyester Phosphorus. Résumé : A novel phosphorus-containing copolyester, poly(trimethylene terephthalate)-co-poly(trimethylene DDP)s (PTTP), was synthesized through esterification and polycondensation of terephthalic acid (TPA), 1,3-propane diol (PDO), and 9,10-dihydro-10-[2,3-di(hydroxycarbonyl)propyl]-10-phospha-phenanthrene-10-oxide (DDP). The analysis of phosphorus content and the test of intrinsic viscosity indicated that DDP was successfully introduced to the poly(trimethylene terephthalate) (PTT) chain. The chemical structure of the resulting copolyesters was further confirmed by 1H NMR and 31P NMR. The thermal behaviors were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), and it was shown that the introduction of DDP lowered the melting temperature and crystallization because of its bulky pendent groups and decreased the initial decomposition temperature in the nitrogen atmosphere due to its weak P−C bond. The flame retardant properties of the resulting copolyesters were characterized by limiting oxygen index (LOI) and cone calorimeter, and it was shown that the copolyesters had good inherent flame retardancy. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1006917 [article] Novel inherently flame-retardant poly(trimethylene terephthalate) copolyester with the phosphorus-containing linking pendent group [texte imprimé] / Hong-Bing Chen, Auteur ; Yi Zhang, Auteur ; Chen, Li, Auteur . - 2010 . - pp 7052–7059.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 15 (Août 2010) . - pp 7052–7059
Mots-clés : Copolyester Phosphorus. Résumé : A novel phosphorus-containing copolyester, poly(trimethylene terephthalate)-co-poly(trimethylene DDP)s (PTTP), was synthesized through esterification and polycondensation of terephthalic acid (TPA), 1,3-propane diol (PDO), and 9,10-dihydro-10-[2,3-di(hydroxycarbonyl)propyl]-10-phospha-phenanthrene-10-oxide (DDP). The analysis of phosphorus content and the test of intrinsic viscosity indicated that DDP was successfully introduced to the poly(trimethylene terephthalate) (PTT) chain. The chemical structure of the resulting copolyesters was further confirmed by 1H NMR and 31P NMR. The thermal behaviors were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), and it was shown that the introduction of DDP lowered the melting temperature and crystallization because of its bulky pendent groups and decreased the initial decomposition temperature in the nitrogen atmosphere due to its weak P−C bond. The flame retardant properties of the resulting copolyesters were characterized by limiting oxygen index (LOI) and cone calorimeter, and it was shown that the copolyesters had good inherent flame retardancy. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1006917 Toward polymer product design. I. dynamic optimization of average molecular weights and polydispersity index in batch free radical polymerization / Xi Chen in Industrial & engineering chemistry research, Vol. 48 N° 14 (Juillet 2009)
[article]
in Industrial & engineering chemistry research > Vol. 48 N° 14 (Juillet 2009) . - pp. 6739–6748
Titre : Toward polymer product design. I. dynamic optimization of average molecular weights and polydispersity index in batch free radical polymerization Type de document : texte imprimé Auteurs : Xi Chen, Auteur ; Chen, Li, Auteur ; Jian Feng, Auteur Année de publication : 2009 Article en page(s) : pp. 6739–6748 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Polymer products Molecular weight distribution Polydispersity index Stickler−Panke−Hamielec model Résumé : In the polymer industry, product quality is usually determined by the molecular weight distribution of polymer products. We propose a comprehensive study of polymer product design through dynamic optimization of average molecular weights and the polydispersity index in batch free radical polymerization. After analyzing and validating the modified Stickler−Panke−Hamielec (SPH) model, this paper extends the model to achieve product design with a specified polymer molecular weight distribution for various optimization goals. Conversion maximization under isothermal conditions was studied first. We concluded that dynamic optimization is useful to obtain desired products. However, some specifications of polymer molecular weight distribution cannot be achieved under isothermal conditions. Therefore, optimization with piecewise constant temperature profiles was also studied to extend the range of product specifications. Considering the practical requirement for productivity in engineering applications, reaction time minimization with specified conversion was studied with various temperature profiles. Besides the strategy of optimizing the temperature profile, dynamic optimization of initiator feed profiles is also presented. The results show that polymer product design with a specified polymer molecular weight distribution can be achieved using dynamic optimization of the temperature and initiator profiles in a batch reaction. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801844u [article] Toward polymer product design. I. dynamic optimization of average molecular weights and polydispersity index in batch free radical polymerization [texte imprimé] / Xi Chen, Auteur ; Chen, Li, Auteur ; Jian Feng, Auteur . - 2009 . - pp. 6739–6748.
Chemical engineering
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 48 N° 14 (Juillet 2009) . - pp. 6739–6748
Mots-clés : Polymer products Molecular weight distribution Polydispersity index Stickler−Panke−Hamielec model Résumé : In the polymer industry, product quality is usually determined by the molecular weight distribution of polymer products. We propose a comprehensive study of polymer product design through dynamic optimization of average molecular weights and the polydispersity index in batch free radical polymerization. After analyzing and validating the modified Stickler−Panke−Hamielec (SPH) model, this paper extends the model to achieve product design with a specified polymer molecular weight distribution for various optimization goals. Conversion maximization under isothermal conditions was studied first. We concluded that dynamic optimization is useful to obtain desired products. However, some specifications of polymer molecular weight distribution cannot be achieved under isothermal conditions. Therefore, optimization with piecewise constant temperature profiles was also studied to extend the range of product specifications. Considering the practical requirement for productivity in engineering applications, reaction time minimization with specified conversion was studied with various temperature profiles. Besides the strategy of optimizing the temperature profile, dynamic optimization of initiator feed profiles is also presented. The results show that polymer product design with a specified polymer molecular weight distribution can be achieved using dynamic optimization of the temperature and initiator profiles in a batch reaction. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801844u