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Integration of microreactors with spectroscopic detection for online reaction monitoring and catalyst characterization / Jun Yue in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp 14583–14609 Titre : Integration of microreactors with spectroscopic detection for online reaction monitoring and catalyst characterization Type de document : texte imprimé Auteurs : Jun Yue, Auteur ; Jaap C. Schouten, Auteur ; T. Alexander Nijhuis, Auteur Année de publication : 2013 Article en page(s) : pp 14583–14609 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Microreactors Catalyst Résumé : Microreactor technology has gained significant popularity in the chemical and process industry in the past decade. The development of microreactors either as innovative production units for chemical synthesis or as promising laboratory tools for reaction and kinetic studies relies highly on the capability of performing online analyses, which opens great opportunities for the integration of spectroscopic detection techniques. This paper gives an overview of the state-of-the-art in the combination of microreactors with spectroscopic analyses for online reaction monitoring and catalyst characterization. In this upcoming field, many studies have been carried out combining fluorescence, ultraviolet–visible, infrared, Raman, X-ray, and nuclear magnetic resonance spectroscopy. Current research progress is reviewed, with emphasis on the existing integration schemes and selected application examples that demonstrate the potential of online spectroscopic detection for rapid microreactor process analysis and optimization. An outlook on the future development in this area is also presented. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301258j [article] Integration of microreactors with spectroscopic detection for online reaction monitoring and catalyst characterization [texte imprimé] / Jun Yue, Auteur ; Jaap C. Schouten, Auteur ; T. Alexander Nijhuis, Auteur . - 2013 . - pp 14583–14609. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp 14583–14609 Mots-clés : Microreactors Catalyst Résumé : Microreactor technology has gained significant popularity in the chemical and process industry in the past decade. The development of microreactors either as innovative production units for chemical synthesis or as promising laboratory tools for reaction and kinetic studies relies highly on the capability of performing online analyses, which opens great opportunities for the integration of spectroscopic detection techniques. This paper gives an overview of the state-of-the-art in the combination of microreactors with spectroscopic analyses for online reaction monitoring and catalyst characterization. In this upcoming field, many studies have been carried out combining fluorescence, ultraviolet–visible, infrared, Raman, X-ray, and nuclear magnetic resonance spectroscopy. Current research progress is reviewed, with emphasis on the existing integration schemes and selected application examples that demonstrate the potential of online spectroscopic detection for rapid microreactor process analysis and optimization. An outlook on the future development in this area is also presented. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301258j

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Intensification approaches for biodiesel synthesis from waste cooking oil / Ganesh L. Maddikeri in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14610–14628 Titre : Intensification approaches for biodiesel synthesis from waste cooking oil : A review Type de document : texte imprimé Auteurs : Ganesh L. Maddikeri, Auteur ; Aniruddha B. Pandit, Auteur ; Parag R. Gogate, Auteur Année de publication : 2013 Article en page(s) : pp. 14610–14628 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Biodiesel Résumé : The use of biodiesel as an alternative fuel has become more attractive recently because of its environmental benefits such as nontoxicity and biodegradability. However, due to the unfavorable economics and other problems for design and operation of large scale reactors, commercialization of biodiesel has not been significantly effective. The specific challenges in the synthesis route based on transesterification include higher separation times, high operating cost, high energy consumption, and low production efficiency due to equilibrium limitations. The present work highlights the potential use of waste cooking oil as a cheap and economical feedstock discussing the advantages of the process and limitations for transesterification reaction. Improvements in the synthesis process based on the different pretreatment methods and process intensifying techniques are discussed with specific reference to transesterification of waste cooking oil. Different physical and chemical pretreatment methods required for the preparation of feedstock include filtration, drying, acidic esterification, adsorption, crystallization, and distillation for the removal of fatty acids and other contaminants. The critical review also highlights the different process intensification techniques such as cavitational reactors, microwave irradiation, microchannel reactor, oscillatory flow reactor, use of cosolvent, and supercritical transesterification process that can be used for biodiesel production process with an objective of enhancing the reaction rate, reduction in the molar ratio of alcohol to oil, and energy input by intensifying the transport processes and overcoming the equilibrium limitations. Guidelines for the selection of optimum operating parameters have also been given with comparative analysis of the different approaches of process intensification. Finally, some recommendations have been made for the possible research that needs to be done for successful commercialization of biodiesel synthesis. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301675j [article] Intensification approaches for biodiesel synthesis from waste cooking oil : A review [texte imprimé] / Ganesh L. Maddikeri, Auteur ; Aniruddha B. Pandit, Auteur ; Parag R. Gogate, Auteur . - 2013 . - pp. 14610–14628. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14610–14628 Mots-clés : Biodiesel Résumé : The use of biodiesel as an alternative fuel has become more attractive recently because of its environmental benefits such as nontoxicity and biodegradability. However, due to the unfavorable economics and other problems for design and operation of large scale reactors, commercialization of biodiesel has not been significantly effective. The specific challenges in the synthesis route based on transesterification include higher separation times, high operating cost, high energy consumption, and low production efficiency due to equilibrium limitations. The present work highlights the potential use of waste cooking oil as a cheap and economical feedstock discussing the advantages of the process and limitations for transesterification reaction. Improvements in the synthesis process based on the different pretreatment methods and process intensifying techniques are discussed with specific reference to transesterification of waste cooking oil. Different physical and chemical pretreatment methods required for the preparation of feedstock include filtration, drying, acidic esterification, adsorption, crystallization, and distillation for the removal of fatty acids and other contaminants. The critical review also highlights the different process intensification techniques such as cavitational reactors, microwave irradiation, microchannel reactor, oscillatory flow reactor, use of cosolvent, and supercritical transesterification process that can be used for biodiesel production process with an objective of enhancing the reaction rate, reduction in the molar ratio of alcohol to oil, and energy input by intensifying the transport processes and overcoming the equilibrium limitations. Guidelines for the selection of optimum operating parameters have also been given with comparative analysis of the different approaches of process intensification. Finally, some recommendations have been made for the possible research that needs to be done for successful commercialization of biodiesel synthesis. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301675j

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UV-curable functionalized graphene oxide/polyurethane acrylate nanocomposite coatings with enhanced thermal stability and mechanical properties / Bin Yu in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14629-14636 Titre : UV-curable functionalized graphene oxide/polyurethane acrylate nanocomposite coatings with enhanced thermal stability and mechanical properties Type de document : texte imprimé Auteurs : Bin Yu, Auteur ; Xin Wang, Auteur ; Weiyi Xing, Auteur Année de publication : 2013 Article en page(s) : pp. 14629-14636 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Mechanical properties Thermal stability NanocompositeUltraviolet radiation Résumé : Functionalized graphene oxide (FGO) was synthesized and subsequently incorporated into polyurethane acrylate (PUA) by UV curing technology. The structural and morphological features of FGO/PUA nanocomposite coatings were characterized by FTIR, XRD, and TEM. The results showed that FGO sheets were uniformly dispersed into the PUA matrix and formed the strong interfacial adhesion with PUA owing to the formation of the cross-linking networks between FGO and PUA after UV curing. The incorporation of FGO effectively enhanced the thermal stability and mechanical properties of host polymer. The initial degradation temperature of the PUA composite with 1.0 wt % FGO was increased to 316 °C from 299 °C for neat PUA. Meanwhile, the storage modulus and tensile strength of the PUA composite with 1.0 wt % FGO were also improved by 37% and 73%, respectively, compared with those of neat PUA. The slight increase in glass transition temperature (Tg) of the composites was observed upon the incorporation of FGO. By contrast, untreated GO/PUA nanocomposites exhibited relatively low thermal stability and poor mechanical properties than its modified-GO counterpart. The covalent functionalization of graphene oxide presented herein will provide a feasible and effective approach to obtain high-performance UV-curing nanocomposite coatings. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620375 [article] UV-curable functionalized graphene oxide/polyurethane acrylate nanocomposite coatings with enhanced thermal stability and mechanical properties [texte imprimé] / Bin Yu, Auteur ; Xin Wang, Auteur ; Weiyi Xing, Auteur . - 2013 . - pp. 14629-14636. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14629-14636 Mots-clés : Mechanical properties Thermal stability NanocompositeUltraviolet radiation Résumé : Functionalized graphene oxide (FGO) was synthesized and subsequently incorporated into polyurethane acrylate (PUA) by UV curing technology. The structural and morphological features of FGO/PUA nanocomposite coatings were characterized by FTIR, XRD, and TEM. The results showed that FGO sheets were uniformly dispersed into the PUA matrix and formed the strong interfacial adhesion with PUA owing to the formation of the cross-linking networks between FGO and PUA after UV curing. The incorporation of FGO effectively enhanced the thermal stability and mechanical properties of host polymer. The initial degradation temperature of the PUA composite with 1.0 wt % FGO was increased to 316 °C from 299 °C for neat PUA. Meanwhile, the storage modulus and tensile strength of the PUA composite with 1.0 wt % FGO were also improved by 37% and 73%, respectively, compared with those of neat PUA. The slight increase in glass transition temperature (Tg) of the composites was observed upon the incorporation of FGO. By contrast, untreated GO/PUA nanocomposites exhibited relatively low thermal stability and poor mechanical properties than its modified-GO counterpart. The covalent functionalization of graphene oxide presented herein will provide a feasible and effective approach to obtain high-performance UV-curing nanocomposite coatings. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620375

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Intercalation of gastropod shell derived calcium oxide in clay and application in phosphate removal from aqua medium / N. A. Oladoja in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14637-14645 Titre : Intercalation of gastropod shell derived calcium oxide in clay and application in phosphate removal from aqua medium Type de document : texte imprimé Auteurs : N. A. Oladoja, Auteur ; C. O. Aboluwoye, Auteur ; I. A. Ololade, Auteur Année de publication : 2013 Article en page(s) : pp. 14637-14645 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Gastropod Résumé : The phosphate sorption potential of the layered framework of naturally occurring clay, which acts as a host in the sorption process, was boosted via intercalation of CaO derived from a Gastropod shell (GS). GS was used as precursor for the synthesis of the CaO in the perspective of waste recycling and cost minimization in environmental remediation. The phosphate sorption potential, PZC, and the surface area of raw clay sample were substantially enhanced by the intercalation process. The value of the Langmuir monolayer sorption capacity (qm mg/g) increased from 49.02 to 71.43, PZC values increased from 4.70 to 7.20, and the surface area (m2/g) value increased from 23 to 103 after the intercalation process. The modification caused no change in the clay surficial microstructure but increased the lattice spacing of the clay framework. Increase in phosphate solution pH triggered monotonical reduction in the magnitude of phosphate sorbed while increase in phosphate solution ionic strength and concentration of anionic interferences caused an increase in the amount of phosphate sorbed per gram of sorbent. Phosphate sorption caused no change in the surficial microstructure of either sorbents but the crystallinity of the sorbent was considerably impacted, especially in the raw sample. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301520v [article] Intercalation of gastropod shell derived calcium oxide in clay and application in phosphate removal from aqua medium [texte imprimé] / N. A. Oladoja, Auteur ; C. O. Aboluwoye, Auteur ; I. A. Ololade, Auteur . - 2013 . - pp. 14637-14645. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14637-14645 Mots-clés : Gastropod Résumé : The phosphate sorption potential of the layered framework of naturally occurring clay, which acts as a host in the sorption process, was boosted via intercalation of CaO derived from a Gastropod shell (GS). GS was used as precursor for the synthesis of the CaO in the perspective of waste recycling and cost minimization in environmental remediation. The phosphate sorption potential, PZC, and the surface area of raw clay sample were substantially enhanced by the intercalation process. The value of the Langmuir monolayer sorption capacity (qm mg/g) increased from 49.02 to 71.43, PZC values increased from 4.70 to 7.20, and the surface area (m2/g) value increased from 23 to 103 after the intercalation process. The modification caused no change in the clay surficial microstructure but increased the lattice spacing of the clay framework. Increase in phosphate solution pH triggered monotonical reduction in the magnitude of phosphate sorbed while increase in phosphate solution ionic strength and concentration of anionic interferences caused an increase in the amount of phosphate sorbed per gram of sorbent. Phosphate sorption caused no change in the surficial microstructure of either sorbents but the crystallinity of the sorbent was considerably impacted, especially in the raw sample. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301520v

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Solution crystallization of vanillin in the presence of a liquid–liquid phase separation / Haiping Zhao in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14646-14652 Titre : Solution crystallization of vanillin in the presence of a liquid–liquid phase separation Type de document : texte imprimé Auteurs : Haiping Zhao, Auteur ; Chuang Xie, Auteur ; Zhao Xu, Auteur Année de publication : 2013 Article en page(s) : pp. 14646-14652 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Phase separation Liquid phase Solution crystallization Résumé : The crystallization process of vanillin in a 1-propanol/water system was investigated. It was found that liquid— liquid phase separation, also termed oiling out, will happen under some conditions. To fully understand this process, the oiling out as well as the following nucleation and crystal growth of this compound were investigated by using series of in situ tools such as FBRM, ATR-FTIR, and PVM. The phase diagram, including the solubility curve and the liquid―liquid separation curves, was determined experimentally. Meanwhile, the influence of oiling out on the properties of the final crystalline product was analyzed. It was proposed that crystallization mechanisms of vanillin might be significantly different depending on the position of the crystallization profile in the phase diagram. By using the fundamental data of phase diagram, control and optimization of solution crystallization of vanillin could be achieved to avoid or suppress the oiling out and to get products with high purity and ideal crystalline properties. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620377 [article] Solution crystallization of vanillin in the presence of a liquid–liquid phase separation [texte imprimé] / Haiping Zhao, Auteur ; Chuang Xie, Auteur ; Zhao Xu, Auteur . - 2013 . - pp. 14646-14652. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14646-14652 Mots-clés : Phase separation Liquid phase Solution crystallization Résumé : The crystallization process of vanillin in a 1-propanol/water system was investigated. It was found that liquid— liquid phase separation, also termed oiling out, will happen under some conditions. To fully understand this process, the oiling out as well as the following nucleation and crystal growth of this compound were investigated by using series of in situ tools such as FBRM, ATR-FTIR, and PVM. The phase diagram, including the solubility curve and the liquid―liquid separation curves, was determined experimentally. Meanwhile, the influence of oiling out on the properties of the final crystalline product was analyzed. It was proposed that crystallization mechanisms of vanillin might be significantly different depending on the position of the crystallization profile in the phase diagram. By using the fundamental data of phase diagram, control and optimization of solution crystallization of vanillin could be achieved to avoid or suppress the oiling out and to get products with high purity and ideal crystalline properties. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620377

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Esterification of free fatty acids in used cooking oil using ion-exchange resins as catalysts / Sumaiya Zainal Abidin in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14653-14664 Titre : Esterification of free fatty acids in used cooking oil using ion-exchange resins as catalysts : An efficient pretreatment method for biodiesel feedstock Type de document : texte imprimé Auteurs : Sumaiya Zainal Abidin, Auteur ; Kathleen F. Haigh, Auteur ; Basudeb Saha, Auteur Année de publication : 2013 Article en page(s) : pp. 14653-14664 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Pretreatment Catalyst Esterification Résumé : The esterification of used cooking oil (UCO) with methanol was studied using different types of ion-exchange resins, that is, Purolite D5081, Purolite D5082, and Amberlyst 36. Several catalyst characterization analyses (elemental analysis, surface area measurement, particle size distribution analysis, scanning electron microscopy analysis, true density measurement, and acid capacity analysis) have been conducted in the screening stage. Of all of the catalysts investigated, Purolite D5081 resin showed the best catalytic performance and was selected for further experimental studies. The esterification process was carried out in a jacketed stirred batch reactor for 8 h. Elimination of mass transfer resistances and the effect of catalyst loading (0.5―1.5% w/w), reaction temperature (50―65 °C), and methanol to UCO feed mole ratio (4:1—12:1) on the conversion of FFAs were investigated. The highest FFAs conversion was found to be 92%, at a catalyst loading of 1.25% w/w, 60 °C reaction temperature, 6:1 methanol to UCO molar ratio, and stirring speed of 475 rpm. During the reusability study, the conversion of catalyst dropped by 8―10% after each reutilization cycle. Several experiments have been conducted through the homogeneous contribution study, and the results confirmed that both resin pore blockage and sulfur leaching are dominant factors that decrease the catalytic performance of Purolite D5081 ion-exchange resin. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620378 [article] Esterification of free fatty acids in used cooking oil using ion-exchange resins as catalysts : An efficient pretreatment method for biodiesel feedstock [texte imprimé] / Sumaiya Zainal Abidin, Auteur ; Kathleen F. Haigh, Auteur ; Basudeb Saha, Auteur . - 2013 . - pp. 14653-14664. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14653-14664 Mots-clés : Pretreatment Catalyst Esterification Résumé : The esterification of used cooking oil (UCO) with methanol was studied using different types of ion-exchange resins, that is, Purolite D5081, Purolite D5082, and Amberlyst 36. Several catalyst characterization analyses (elemental analysis, surface area measurement, particle size distribution analysis, scanning electron microscopy analysis, true density measurement, and acid capacity analysis) have been conducted in the screening stage. Of all of the catalysts investigated, Purolite D5081 resin showed the best catalytic performance and was selected for further experimental studies. The esterification process was carried out in a jacketed stirred batch reactor for 8 h. Elimination of mass transfer resistances and the effect of catalyst loading (0.5―1.5% w/w), reaction temperature (50―65 °C), and methanol to UCO feed mole ratio (4:1—12:1) on the conversion of FFAs were investigated. The highest FFAs conversion was found to be 92%, at a catalyst loading of 1.25% w/w, 60 °C reaction temperature, 6:1 methanol to UCO molar ratio, and stirring speed of 475 rpm. During the reusability study, the conversion of catalyst dropped by 8―10% after each reutilization cycle. Several experiments have been conducted through the homogeneous contribution study, and the results confirmed that both resin pore blockage and sulfur leaching are dominant factors that decrease the catalytic performance of Purolite D5081 ion-exchange resin. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620378

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Adsorption features of phthalates and organophosphorus compounds on silicon wafers / Sabrine Tlili in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14665–14672 Titre : Adsorption features of phthalates and organophosphorus compounds on silicon wafers Type de document : texte imprimé Auteurs : Sabrine Tlili, Auteur ; Nathalie Hayeck, Auteur ; Sasho Gligorovski, Auteur Année de publication : 2013 Article en page(s) : pp. 14665–14672 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorption Phthalates Résumé : Short-time adsorption and desorption behavior of three high-boiling point organic contaminants, diethyl phthalate (DEP), tri-(2-chloroethyl)-phosphate (TCEP), and tri-(2-cloropropyl)-phosphate (TCPP), on silicon wafer surface were investigated. Adsorption constants kads and desorption constants kdes were experimentally measured. Comparing the obtained kinetic parameters, the time-dependent changes in their surface concentrations were found to be governed by desorption constants. The adsorption and desorption constants were also measured as a function of temperature. Subsequently, a series of time-dependent surface concentrations of DEP, TCEP, and TCPP were simulated under various ambient concentrations. Finally, an estimation of the maximum allowable wafer exposure according to the International Technology Roadmap for Semiconductors (ITRS) was performed. The results of this study can provide information to better control organic contamination and to meet requirements of the microelectronic devices qualities. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301501b [article] Adsorption features of phthalates and organophosphorus compounds on silicon wafers [texte imprimé] / Sabrine Tlili, Auteur ; Nathalie Hayeck, Auteur ; Sasho Gligorovski, Auteur . - 2013 . - pp. 14665–14672. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14665–14672 Mots-clés : Adsorption Phthalates Résumé : Short-time adsorption and desorption behavior of three high-boiling point organic contaminants, diethyl phthalate (DEP), tri-(2-chloroethyl)-phosphate (TCEP), and tri-(2-cloropropyl)-phosphate (TCPP), on silicon wafer surface were investigated. Adsorption constants kads and desorption constants kdes were experimentally measured. Comparing the obtained kinetic parameters, the time-dependent changes in their surface concentrations were found to be governed by desorption constants. The adsorption and desorption constants were also measured as a function of temperature. Subsequently, a series of time-dependent surface concentrations of DEP, TCEP, and TCPP were simulated under various ambient concentrations. Finally, an estimation of the maximum allowable wafer exposure according to the International Technology Roadmap for Semiconductors (ITRS) was performed. The results of this study can provide information to better control organic contamination and to meet requirements of the microelectronic devices qualities. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301501b

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Influence of reaction conditions on catalyst behavior during the early stages of gas phase ethylene homo- and copolymerization / Estevan Tioni in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14673-14684 Titre : Influence of reaction conditions on catalyst behavior during the early stages of gas phase ethylene homo- and copolymerization Type de document : texte imprimé Auteurs : Estevan Tioni, Auteur ; Jean Pierre Broyer, Auteur ; Vincent Monteil, Auteur Année de publication : 2013 Article en page(s) : pp. 14673-14684 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Copolymerization Catalyst Résumé : A packed bed stopped flow minireactor (3 mL) suitable for performing gas phase polymerizations of olefins has been used to study the initial phases of ethylene homo- and copolymerization with two supported metallocene catalysts. The reactor can be used to perform gas phase polymerizations at times as short as 100 ms under industrially relevant conditions. It has been used to follow the evolution of the rate of polymerization, the gas phase temperature (and indirectly the particle temperature), and the polymer properties (molecular weight distribution, melting temperature, and crystallinity) for the two catalysts. It is shown that polymerization activity during the first 2―5 s of reaction can be up to 20 times higher than what is measured at longer polymerization times. The main consequence is the release of a significant amount of heat due to the rapid reaction that has to be efficiently evacuated in order to avoid particle overheating and melting. It has been seen that insufficient heat removal can strongly influence the behavior of the active sites, eventually leading to uncontrolled transfer reactions and polymers with unusually broad molecular weight distributions (MWD). It is also observed that the kinetic behavior of the two types of catalyst is similar at short times. Finally, some influence of particle size on reaction rate and molecular weight is observed between the largest and smallest catalyst particle cuts. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620380 [article] Influence of reaction conditions on catalyst behavior during the early stages of gas phase ethylene homo- and copolymerization [texte imprimé] / Estevan Tioni, Auteur ; Jean Pierre Broyer, Auteur ; Vincent Monteil, Auteur . - 2013 . - pp. 14673-14684. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14673-14684 Mots-clés : Copolymerization Catalyst Résumé : A packed bed stopped flow minireactor (3 mL) suitable for performing gas phase polymerizations of olefins has been used to study the initial phases of ethylene homo- and copolymerization with two supported metallocene catalysts. The reactor can be used to perform gas phase polymerizations at times as short as 100 ms under industrially relevant conditions. It has been used to follow the evolution of the rate of polymerization, the gas phase temperature (and indirectly the particle temperature), and the polymer properties (molecular weight distribution, melting temperature, and crystallinity) for the two catalysts. It is shown that polymerization activity during the first 2―5 s of reaction can be up to 20 times higher than what is measured at longer polymerization times. The main consequence is the release of a significant amount of heat due to the rapid reaction that has to be efficiently evacuated in order to avoid particle overheating and melting. It has been seen that insufficient heat removal can strongly influence the behavior of the active sites, eventually leading to uncontrolled transfer reactions and polymers with unusually broad molecular weight distributions (MWD). It is also observed that the kinetic behavior of the two types of catalyst is similar at short times. Finally, some influence of particle size on reaction rate and molecular weight is observed between the largest and smallest catalyst particle cuts. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620380

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Chlorohydrination of alyl chloride to dichloropropanol in a microchemical system / Jisong Zhang in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14685-14691 Titre : Chlorohydrination of alyl chloride to dichloropropanol in a microchemical system Type de document : texte imprimé Auteurs : Jisong Zhang, Auteur ; Jing Tan, Auteur ; Kai Wang, Auteur Année de publication : 2013 Article en page(s) : pp. 14685-14691 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Microchemical system Résumé : A microchemical system, including two micromixers and a delay loop, is specially designed to carry out the chlorohydrination of allyl chloride with chlorine in water. Chlorine is dissolved in water in the first micromixer and then reacts with allyl chloride to produce dichloropropanol in the second micromixer. The reaction can be accomplished in the delay loop with a residence time less than 10 s and the selectivity higher than 98%. A multistage strategy which connects several microchemical units in series has been developed and demonstrated. The dichloropropanol concentration higher than 6 wt % with the selectivity higher than 96% can be successfully reached using this strategy. The results show that low temperature and high pressure could greatly improve the microreaction performance. In contrast to the conventional reaction process, the microreaction process has the advantages for higher yield, higher dichloropropanol concentration, less water waste, and lower energy consumption. Moreover, the new process could make the reaction process employing chlorine more controllable and safe. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301816k [article] Chlorohydrination of alyl chloride to dichloropropanol in a microchemical system [texte imprimé] / Jisong Zhang, Auteur ; Jing Tan, Auteur ; Kai Wang, Auteur . - 2013 . - pp. 14685-14691. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14685-14691 Mots-clés : Microchemical system Résumé : A microchemical system, including two micromixers and a delay loop, is specially designed to carry out the chlorohydrination of allyl chloride with chlorine in water. Chlorine is dissolved in water in the first micromixer and then reacts with allyl chloride to produce dichloropropanol in the second micromixer. The reaction can be accomplished in the delay loop with a residence time less than 10 s and the selectivity higher than 98%. A multistage strategy which connects several microchemical units in series has been developed and demonstrated. The dichloropropanol concentration higher than 6 wt % with the selectivity higher than 96% can be successfully reached using this strategy. The results show that low temperature and high pressure could greatly improve the microreaction performance. In contrast to the conventional reaction process, the microreaction process has the advantages for higher yield, higher dichloropropanol concentration, less water waste, and lower energy consumption. Moreover, the new process could make the reaction process employing chlorine more controllable and safe. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301816k

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Preparation of highly dispersed nano-La2O3 particles using modified carbon black as an agglomeration inhibitor / Guirong Wang in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14692-14699 Titre : Preparation of highly dispersed nano-La2O3 particles using modified carbon black as an agglomeration inhibitor Type de document : texte imprimé Auteurs : Guirong Wang, Auteur ; Yongshan Zhou, Auteur ; David G. Evans, Auteur Année de publication : 2013 Article en page(s) : pp. 14692-14699 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Agglomeration Carbon black Preparation Résumé : Nanoparticles readily agglomerate, especially during nucleation, growth, and calcination processes. In this work, modified carbon black (MCB) has been used to prevent particle agglomeration during the nucleation step in the preparation of a highly dispersed nano-La(OH), precursor by a coprecipitation reaction. The surface carboxyl groups formed on MCB after modification can adsorb and fix positively charged La3+ ions on the surface. Therefore, nano-La(OH)3 nuclei can be uniformly deposited on the MCB surface. After nucleation, La(OH)3 particles with a size of about 20 nm with a positive surface charge still interact strongly with the negatively charged MCB surface, which effectively prevents their agglomeration during the subsequent aging process. Furthermore, due to the release of CO2 over a wide temperature range from 400 to 700 °C during a subsequent calcination process, La2O3 particles obtained by calcination of the La(OH)3 precursor can be effectively isolated at high temperature and prevented from agglomerating. By using MCB as an agglomeration inhibitor in this way, highly dispersed La2O3 nanoparticles with a size of 50 nm having excellent photoluminescence ability can be prepared. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620382 [article] Preparation of highly dispersed nano-La2O3 particles using modified carbon black as an agglomeration inhibitor [texte imprimé] / Guirong Wang, Auteur ; Yongshan Zhou, Auteur ; David G. Evans, Auteur . - 2013 . - pp. 14692-14699. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14692-14699 Mots-clés : Agglomeration Carbon black Preparation Résumé : Nanoparticles readily agglomerate, especially during nucleation, growth, and calcination processes. In this work, modified carbon black (MCB) has been used to prevent particle agglomeration during the nucleation step in the preparation of a highly dispersed nano-La(OH), precursor by a coprecipitation reaction. The surface carboxyl groups formed on MCB after modification can adsorb and fix positively charged La3+ ions on the surface. Therefore, nano-La(OH)3 nuclei can be uniformly deposited on the MCB surface. After nucleation, La(OH)3 particles with a size of about 20 nm with a positive surface charge still interact strongly with the negatively charged MCB surface, which effectively prevents their agglomeration during the subsequent aging process. Furthermore, due to the release of CO2 over a wide temperature range from 400 to 700 °C during a subsequent calcination process, La2O3 particles obtained by calcination of the La(OH)3 precursor can be effectively isolated at high temperature and prevented from agglomerating. By using MCB as an agglomeration inhibitor in this way, highly dispersed La2O3 nanoparticles with a size of 50 nm having excellent photoluminescence ability can be prepared. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620382

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Polymers (Polyvinylpyrrolidones) as active additives modifying the lubricating properties of water / Marian W. Sulek in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14700-14707 Titre : Polymers (Polyvinylpyrrolidones) as active additives modifying the lubricating properties of water Type de document : texte imprimé Auteurs : Marian W. Sulek, Auteur ; Witold Sas, Auteur ; Tomasz Wasilewski, Auteur Année de publication : 2013 Article en page(s) : pp. 14700-14707 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Additive Résumé : Surface active compounds may act as effective additives modifying water lubricity. Their action mechanism consists in the formation of a lubricating film enriched with an active compound. The reasons for the choice of polyvinylpyrrolidones as additives were their physiological inertness and a lack of harmful environmental effects. The tests were carried out on the solutions of two polyvinylpyrrolidones with degrees of polymerization of 450 (PVP 450) and 14400 (PVP 14400). A significant effect of the polymer chain length on physicochemical (viscosity, surface tension, wettability of steel) and tribological properties (resistance to motion, wear, scuffing) has been found. PVP 14400 showed a considerably greater ability to thicken solutions. Over 10 times higher coefficients of viscosity relative to an analogous PVP 450 solution were observed already at a concentration of 5%. A slightly higher ability of PVP 14400 to reduce surface tension was observed. In the case of wettability of steel, a more effective decrease in the wetting angle was observed for PVP 450. However, the differences obtained were not large and usually did not exceed 20%. The measurements of resistance to motion and wear at three constant loads (2000, 3000, 4000 N) as well as tests on antiseizure abilities under a constant velocity increment of load (409 N/s) were carried out using a four-ball tester (T-02 tester). All friction pairs were made of bearing steel. Introducing additives to water significantly affects a decrease in resistance to motion and wear as well as an increase in the ability of a tribological system to prevent seizure. The system did not undergo seizure even at a load of 4 kN. A 2-fold decrease in the coefficient of friction (μ) and an over 30% decrease in the value of wear scar diameters (d) relative to water were observed for PVP 450 and PVP 14400 solutions at 2.0 kN. The use of water as a lubricant led to seizure of the tribological system already at above 2 kN. Addition of the polymers to water also results in a significant improvement in its antiseizure properties. The values of scuffing load (Pt) and limiting pressure of seizure (poz) for individual solutions were even 5 and 15 times higher, respectively, than the values for water. Seizure load (Poz) was also relatively high, and its level was almost two times higher than that for water. The results obtained indicate that polyvinylpyrrolidone used as an additive considerably improves the tribological characteristics of water as a lubricant base. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620383 [article] Polymers (Polyvinylpyrrolidones) as active additives modifying the lubricating properties of water [texte imprimé] / Marian W. Sulek, Auteur ; Witold Sas, Auteur ; Tomasz Wasilewski, Auteur . - 2013 . - pp. 14700-14707. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14700-14707 Mots-clés : Additive Résumé : Surface active compounds may act as effective additives modifying water lubricity. Their action mechanism consists in the formation of a lubricating film enriched with an active compound. The reasons for the choice of polyvinylpyrrolidones as additives were their physiological inertness and a lack of harmful environmental effects. The tests were carried out on the solutions of two polyvinylpyrrolidones with degrees of polymerization of 450 (PVP 450) and 14400 (PVP 14400). A significant effect of the polymer chain length on physicochemical (viscosity, surface tension, wettability of steel) and tribological properties (resistance to motion, wear, scuffing) has been found. PVP 14400 showed a considerably greater ability to thicken solutions. Over 10 times higher coefficients of viscosity relative to an analogous PVP 450 solution were observed already at a concentration of 5%. A slightly higher ability of PVP 14400 to reduce surface tension was observed. In the case of wettability of steel, a more effective decrease in the wetting angle was observed for PVP 450. However, the differences obtained were not large and usually did not exceed 20%. The measurements of resistance to motion and wear at three constant loads (2000, 3000, 4000 N) as well as tests on antiseizure abilities under a constant velocity increment of load (409 N/s) were carried out using a four-ball tester (T-02 tester). All friction pairs were made of bearing steel. Introducing additives to water significantly affects a decrease in resistance to motion and wear as well as an increase in the ability of a tribological system to prevent seizure. The system did not undergo seizure even at a load of 4 kN. A 2-fold decrease in the coefficient of friction (μ) and an over 30% decrease in the value of wear scar diameters (d) relative to water were observed for PVP 450 and PVP 14400 solutions at 2.0 kN. The use of water as a lubricant led to seizure of the tribological system already at above 2 kN. Addition of the polymers to water also results in a significant improvement in its antiseizure properties. The values of scuffing load (Pt) and limiting pressure of seizure (poz) for individual solutions were even 5 and 15 times higher, respectively, than the values for water. Seizure load (Poz) was also relatively high, and its level was almost two times higher than that for water. The results obtained indicate that polyvinylpyrrolidone used as an additive considerably improves the tribological characteristics of water as a lubricant base. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620383

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An antidripping flame retardant finishing for polyethylene terephthalate fabric / Qingli Feng in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14708-14713 Titre : An antidripping flame retardant finishing for polyethylene terephthalate fabric Type de document : texte imprimé Auteurs : Qingli Feng, Auteur ; Xiaoyu Gu, Auteur ; Sheng Zhang, Auteur Année de publication : 2013 Article en page(s) : pp. 14708-14713 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Flame retardant Résumé : A flame retardant system containing 1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP) and ammonium sulfamate (AMS) was proven to be effective on improving the fire performance of polyethylene terephthalate (PET) fabric. The flammability tests indicate that this FR system can impart dripping resistance to PET fabric and the limiting oxygen index value can reach up to 28. The thermal behavior of PET fabric was investigated by thermo-gravimetric analysis. The results indicate that the residual char of treated samples was significantly improved by the presence of HEDP and AMS. The morphology of treated PET fabric residue was also characterized by scanning electron microscope analysis. It has been suggested that intumescent char structures have been formed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620384 [article] An antidripping flame retardant finishing for polyethylene terephthalate fabric [texte imprimé] / Qingli Feng, Auteur ; Xiaoyu Gu, Auteur ; Sheng Zhang, Auteur . - 2013 . - pp. 14708-14713. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14708-14713 Mots-clés : Flame retardant Résumé : A flame retardant system containing 1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP) and ammonium sulfamate (AMS) was proven to be effective on improving the fire performance of polyethylene terephthalate (PET) fabric. The flammability tests indicate that this FR system can impart dripping resistance to PET fabric and the limiting oxygen index value can reach up to 28. The thermal behavior of PET fabric was investigated by thermo-gravimetric analysis. The results indicate that the residual char of treated samples was significantly improved by the presence of HEDP and AMS. The morphology of treated PET fabric residue was also characterized by scanning electron microscope analysis. It has been suggested that intumescent char structures have been formed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620384

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Rapid electromechanical transduction on a single-walled carbon nanotube film / Wonjoon Choi in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14714-14721 Titre : Rapid electromechanical transduction on a single-walled carbon nanotube film : Sensing fast mechanical loading via detection of electrical signal change Type de document : texte imprimé Auteurs : Wonjoon Choi, Auteur ; Jinkee Hong, Auteur Année de publication : 2013 Article en page(s) : pp. 14714-14721 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Loading Carbon Nanotube Résumé : Carbon nanotubes (CNTs) have been widely explored as next generation embedded-strain-pressure sensors. However, most investigations of CNT sensors did not consider the response time as a critical factor, although the ultrafast sensing of mechanical deformation is very important for the detection of dynamic loading or impact, such as in reactive armor systems. Owing to the low capacitance that shortens the response time of the electrical resistance changes induced by mechanical deformation, CNTs are expected to detect rapid electromechanical transduction without delay. Herein, we fabricate single-walled carbon nanotube (SWNT) films on diverse substrates, and evaluate their applications as sensors to detect rapid electromechanical transduction on a macroscopic scale. Under repetitive, high-speed mechanical loading, the SWNT films generate consistent electrical signal changes, which are accurately synchronized with their strain and the beginning of the deformation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301551a [article] Rapid electromechanical transduction on a single-walled carbon nanotube film : Sensing fast mechanical loading via detection of electrical signal change [texte imprimé] / Wonjoon Choi, Auteur ; Jinkee Hong, Auteur . - 2013 . - pp. 14714-14721. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14714-14721 Mots-clés : Loading Carbon Nanotube Résumé : Carbon nanotubes (CNTs) have been widely explored as next generation embedded-strain-pressure sensors. However, most investigations of CNT sensors did not consider the response time as a critical factor, although the ultrafast sensing of mechanical deformation is very important for the detection of dynamic loading or impact, such as in reactive armor systems. Owing to the low capacitance that shortens the response time of the electrical resistance changes induced by mechanical deformation, CNTs are expected to detect rapid electromechanical transduction without delay. Herein, we fabricate single-walled carbon nanotube (SWNT) films on diverse substrates, and evaluate their applications as sensors to detect rapid electromechanical transduction on a macroscopic scale. Under repetitive, high-speed mechanical loading, the SWNT films generate consistent electrical signal changes, which are accurately synchronized with their strain and the beginning of the deformation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301551a

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Mixed micelles of sodium salts of bile acids and tween 40 / Mihalj Posa in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14722-14728 Titre : Mixed micelles of sodium salts of bile acids and tween 40 : Effect of the steroid skeleton on the coefficient of interaction in mixed micelles Type de document : texte imprimé Auteurs : Mihalj Posa, Auteur ; Dejan Cirin, Auteur Année de publication : 2013 Article en page(s) : pp. 14722-14728 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Mixed micelle Résumé : Salts of bile acids are steroid amphiphilic compounds which form micelles consisting of 2―12 monomer units. In nature, the formation of mixed micelles with phospholipids (gall bladder) increases the capacity of bile salts to solubilize cholesterol. Oxo derivatives of bile salts are of special research interest because of their lower membrane toxicity compared to the corresponding OH analogues. In view of the fact that the micelles of anions of oxo derivatives have lower hydrophobicities, it was interesting to study mixed micelles of bile salts and the hydrophobic nonionic cosurfactant Tween 40. With this aim, the critical micelle concentrations were determined by conductometric and tensiometric methods. It was found that the absolute value of the interaction parameter (measure of the synergism between different constitutive units, i.e., the measure of the departure from an ideal micelle) increases with the increase in the number of equatorial OH or oxo groups in the steroid skeleton of the bile acid anion. Namely, the oxygen atoms of these groups are shifted toward the steroid skeleton mean plane, which facilitates effective formation of hydrogen bonds with the polyoxyethylene chains of the polar head. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620386 [article] Mixed micelles of sodium salts of bile acids and tween 40 : Effect of the steroid skeleton on the coefficient of interaction in mixed micelles [texte imprimé] / Mihalj Posa, Auteur ; Dejan Cirin, Auteur . - 2013 . - pp. 14722-14728. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14722-14728 Mots-clés : Mixed micelle Résumé : Salts of bile acids are steroid amphiphilic compounds which form micelles consisting of 2―12 monomer units. In nature, the formation of mixed micelles with phospholipids (gall bladder) increases the capacity of bile salts to solubilize cholesterol. Oxo derivatives of bile salts are of special research interest because of their lower membrane toxicity compared to the corresponding OH analogues. In view of the fact that the micelles of anions of oxo derivatives have lower hydrophobicities, it was interesting to study mixed micelles of bile salts and the hydrophobic nonionic cosurfactant Tween 40. With this aim, the critical micelle concentrations were determined by conductometric and tensiometric methods. It was found that the absolute value of the interaction parameter (measure of the synergism between different constitutive units, i.e., the measure of the departure from an ideal micelle) increases with the increase in the number of equatorial OH or oxo groups in the steroid skeleton of the bile acid anion. Namely, the oxygen atoms of these groups are shifted toward the steroid skeleton mean plane, which facilitates effective formation of hydrogen bonds with the polyoxyethylene chains of the polar head. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620386

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Synthesis, characterization, and activity evaluation of DyVO4/g-C3N4 composites under visible-light irradiation / Yiming He in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14729-14737 Titre : Synthesis, characterization, and activity evaluation of DyVO4/g-C3N4 composites under visible-light irradiation Type de document : texte imprimé Auteurs : Yiming He, Auteur ; Jun Cai, Auteur ; Tingting Li, Auteur Année de publication : 2013 Article en page(s) : pp. 14729-14737 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Visible radiation Composite material Résumé : DyVO4/graphitic carbon nitride (DyVO4/g-C3N4) composite photocatalyst with visible-light response was prepared by a milling and heating treatment method. The synthesized powder was characterized by X-ray diffraction, thermogravimetry/differential thermal analysis, N2 adsorption, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and UV―vis diffuse reflection spectroscopy. The activity of composite photocatalyst DyVO4/g-C3N4 for photodegradation of rhodamine B is much higher than that of either single-phase g-C3N4 or DyVO4. The obviously increased performance of DyVO4/g-C3N4 is mainly ascribed to the electron-hole separation enhancement at the interface of the two semiconductors, as proven by photoluminescence spectroscopy and photocurrent measurement. In addition, it is found that holes and •O2― are the main active species in the photocatalytic oxidation of RhB solution in the presence of DyVO4/g-C3N4 composite. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620387 [article] Synthesis, characterization, and activity evaluation of DyVO4/g-C3N4 composites under visible-light irradiation [texte imprimé] / Yiming He, Auteur ; Jun Cai, Auteur ; Tingting Li, Auteur . - 2013 . - pp. 14729-14737. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14729-14737 Mots-clés : Visible radiation Composite material Résumé : DyVO4/graphitic carbon nitride (DyVO4/g-C3N4) composite photocatalyst with visible-light response was prepared by a milling and heating treatment method. The synthesized powder was characterized by X-ray diffraction, thermogravimetry/differential thermal analysis, N2 adsorption, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and UV―vis diffuse reflection spectroscopy. The activity of composite photocatalyst DyVO4/g-C3N4 for photodegradation of rhodamine B is much higher than that of either single-phase g-C3N4 or DyVO4. The obviously increased performance of DyVO4/g-C3N4 is mainly ascribed to the electron-hole separation enhancement at the interface of the two semiconductors, as proven by photoluminescence spectroscopy and photocurrent measurement. In addition, it is found that holes and •O2― are the main active species in the photocatalytic oxidation of RhB solution in the presence of DyVO4/g-C3N4 composite. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620387

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Poly(4-vinylaniline)-polyaniline bilayer-modified stainless steels for the mitigation of biocorrosion by sulfate-reducing bacteria (SRB) in seawater / Shaojun Yuan in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14738-14751 Titre : Poly(4-vinylaniline)-polyaniline bilayer-modified stainless steels for the mitigation of biocorrosion by sulfate-reducing bacteria (SRB) in seawater Type de document : texte imprimé Auteurs : Shaojun Yuan, Auteur ; Shengwei Tang, Auteur ; Li Lv, Auteur Année de publication : 2013 Article en page(s) : pp. 14738-14751 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Seawater Sulfate-reducing bacteria Stainless steel Résumé : A novel strategy by combination of surface-initiated atom transfer radical polymerization (ATRP) and in situ chemical oxidative graft polymerization was employed to tether stainless steel (SS) with poly(4-vinylaniline)-polyaniline (PVAn-PANI) bilayer coatings for mitigating biocorrosion by sulfate-reducing bacteria (SRB) in seawater. A trichlorosilane coupling agent was first immobilized on the SS surfaces to provide sulfonyl halide groups for surface-initiated ATRP of 4-VAn. A subsequent grafting of PANI onto the PVAn-grafted surface was accomplished by in situ chemical oxidative graft polymerization of aniline. The PVAn-PANI bilayer coatings were finally quaternized by hexylbromide to generate biocidal functionality. The so-synthesized SS surface was found to significantly reduce bacterial adhesion and biofilm formation. Electrochemical results revealed that the PVAn-PANI modified SS surface exhibited high resistance to biocorrosion by SRB. With the inherent anticorrosion capability and antibacterial properties of quaternized PVAn-PANI bilayers, the functionalized SS substrates are potentially useful to steel-based equipment under harsh marine environments. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620388 [article] Poly(4-vinylaniline)-polyaniline bilayer-modified stainless steels for the mitigation of biocorrosion by sulfate-reducing bacteria (SRB) in seawater [texte imprimé] / Shaojun Yuan, Auteur ; Shengwei Tang, Auteur ; Li Lv, Auteur . - 2013 . - pp. 14738-14751. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14738-14751 Mots-clés : Seawater Sulfate-reducing bacteria Stainless steel Résumé : A novel strategy by combination of surface-initiated atom transfer radical polymerization (ATRP) and in situ chemical oxidative graft polymerization was employed to tether stainless steel (SS) with poly(4-vinylaniline)-polyaniline (PVAn-PANI) bilayer coatings for mitigating biocorrosion by sulfate-reducing bacteria (SRB) in seawater. A trichlorosilane coupling agent was first immobilized on the SS surfaces to provide sulfonyl halide groups for surface-initiated ATRP of 4-VAn. A subsequent grafting of PANI onto the PVAn-grafted surface was accomplished by in situ chemical oxidative graft polymerization of aniline. The PVAn-PANI bilayer coatings were finally quaternized by hexylbromide to generate biocidal functionality. The so-synthesized SS surface was found to significantly reduce bacterial adhesion and biofilm formation. Electrochemical results revealed that the PVAn-PANI modified SS surface exhibited high resistance to biocorrosion by SRB. With the inherent anticorrosion capability and antibacterial properties of quaternized PVAn-PANI bilayers, the functionalized SS substrates are potentially useful to steel-based equipment under harsh marine environments. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620388

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Two-degree-of-freedom controller design for an Ill-conditioned process using H2 decoupling control / Wei Zhang in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14752-14758 Titre : Two-degree-of-freedom controller design for an Ill-conditioned process using H2 decoupling control Type de document : texte imprimé Auteurs : Wei Zhang, Auteur ; Xing He, Auteur ; Shihe Chen, Auteur Année de publication : 2013 Article en page(s) : pp. 14752-14758 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Design Résumé : In this paper, a two-degree-of-freedom (TDOF) controller is designed for an ill-conditioned process based on the H2 decoupling control method. The ill-conditioned process considered stems from the benchmark problem formulated in the IEEE Conference on Decision and Control (CDC). The goal of this paper is to show that lower order controllers can be reached with respect to the given plant and the corresponding design specifications. The orders of the designed TDOF controllers are 2 and 1, respectively, which is much lower than the previously developed methods. The additional benefit is that the new design procedure is simpler than the developed methods as well. In the proposed design procedure, no weight function needs to be chosen and the controller is given in an analytical form. Simulation shows that the designed controllers satisfy all design specifications of the CDC problem. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620389 [article] Two-degree-of-freedom controller design for an Ill-conditioned process using H2 decoupling control [texte imprimé] / Wei Zhang, Auteur ; Xing He, Auteur ; Shihe Chen, Auteur . - 2013 . - pp. 14752-14758. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14752-14758 Mots-clés : Design Résumé : In this paper, a two-degree-of-freedom (TDOF) controller is designed for an ill-conditioned process based on the H2 decoupling control method. The ill-conditioned process considered stems from the benchmark problem formulated in the IEEE Conference on Decision and Control (CDC). The goal of this paper is to show that lower order controllers can be reached with respect to the given plant and the corresponding design specifications. The orders of the designed TDOF controllers are 2 and 1, respectively, which is much lower than the previously developed methods. The additional benefit is that the new design procedure is simpler than the developed methods as well. In the proposed design procedure, no weight function needs to be chosen and the controller is given in an analytical form. Simulation shows that the designed controllers satisfy all design specifications of the CDC problem. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620389

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Polymer extrusion / Zhijun Jiang in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14759-14770 Titre : Polymer extrusion : From control system design to product quality Type de document : texte imprimé Auteurs : Zhijun Jiang, Auteur ; Yi Yang, Auteur ; Shengyong Mo, Auteur Année de publication : 2013 Article en page(s) : pp. 14759-14770 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : System design Control system Résumé : As a major polymer processing technique, polymer extrusion is a continuous process, during which material properties, machine variables, and process variables interact with each other to determine the final product quality. Precise control of key process variables such as barrel temperatures and melt pressure are crucial to ensure a good product quality in the extrusion process. In this paper, the overall extruder control system is constructed by two independent control loops, a single-input―single-output (SISO) control of the melt pressure at die output, and a multiinput―multioutput (MIMO) control of the barrel temperatures. The dynamic behaviors of melt pressure and barrel temperatures were analyzed first. The characteristics of the melt pressure dynamics were as follows: nonlinear and time-varying while the extruder barrel temperatures were nonlinear, slow response, and different zones were highly coupled. Advanced control algorithms were adopted to control these key variables. Experimental results demonstrate the fast response, near-zero overshoot, and precise tracking performance of the proposed control strategies. The robustness of the entire control system was verified through different operating conditions including materials and set points. Ultimately the performance of the entire control system was verified by product quality. The product quality improved significantly with the proposed controller. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620390 [article] Polymer extrusion : From control system design to product quality [texte imprimé] / Zhijun Jiang, Auteur ; Yi Yang, Auteur ; Shengyong Mo, Auteur . - 2013 . - pp. 14759-14770. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14759-14770 Mots-clés : System design Control system Résumé : As a major polymer processing technique, polymer extrusion is a continuous process, during which material properties, machine variables, and process variables interact with each other to determine the final product quality. Precise control of key process variables such as barrel temperatures and melt pressure are crucial to ensure a good product quality in the extrusion process. In this paper, the overall extruder control system is constructed by two independent control loops, a single-input―single-output (SISO) control of the melt pressure at die output, and a multiinput―multioutput (MIMO) control of the barrel temperatures. The dynamic behaviors of melt pressure and barrel temperatures were analyzed first. The characteristics of the melt pressure dynamics were as follows: nonlinear and time-varying while the extruder barrel temperatures were nonlinear, slow response, and different zones were highly coupled. Advanced control algorithms were adopted to control these key variables. Experimental results demonstrate the fast response, near-zero overshoot, and precise tracking performance of the proposed control strategies. The robustness of the entire control system was verified through different operating conditions including materials and set points. Ultimately the performance of the entire control system was verified by product quality. The product quality improved significantly with the proposed controller. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620390

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Circumventing the black-hole problem in design and control of dividing-wall distillation columns / Yufeng Wang in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14771-14792 Titre : Circumventing the black-hole problem in design and control of dividing-wall distillation columns Type de document : texte imprimé Auteurs : Yufeng Wang, Auteur ; Kejin Huang, Auteur ; Shujun Luan, Auteur Année de publication : 2013 Article en page(s) : pp. 14771-14792 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Distillation column Design Résumé : Owing to the great degree of mass integration and energy integration between the prefractionator and the main distillation column, it is usually infeasible to achieve a four-point composition control policy (i.e., the control of the main compositions of the three products and the ratio of the two impurities in the intermediate product) in a dividing-wall distillation column (DWDC), and this restricts, to a certain extent, process applicability and flexibility. The issue is referred to as the black-hole problem in the current work and has received very little attention so far. In this paper, an attempt is made to tackle this intricate problem, and the number of stages in each section of the DWDC is used as adjustment variables to coordinate the relationship between the prefractionator and the main distillation column involved. A simple and yet effective procedure is devised to guide the structural modifications of a given DWDC and the separation of two ternary mixtures of hypothetical components, A, B, and C, and benzene, toluene, and o-xylene are chosen as illustrative examples to evaluate its feasibility and effectiveness. Through steady-state analysis and closed-loop operation studies, it is demonstrated that the black-hole problem can be completely circumvented with the careful adjustment of the number of stages in each section of the DWDC. This outcome gives evidence to the feasibility and effectiveness of the proposed philosophy and indicates a reasonable way to enhance the applicability and flexibilities of the DWDC. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620391 [article] Circumventing the black-hole problem in design and control of dividing-wall distillation columns [texte imprimé] / Yufeng Wang, Auteur ; Kejin Huang, Auteur ; Shujun Luan, Auteur . - 2013 . - pp. 14771-14792. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14771-14792 Mots-clés : Distillation column Design Résumé : Owing to the great degree of mass integration and energy integration between the prefractionator and the main distillation column, it is usually infeasible to achieve a four-point composition control policy (i.e., the control of the main compositions of the three products and the ratio of the two impurities in the intermediate product) in a dividing-wall distillation column (DWDC), and this restricts, to a certain extent, process applicability and flexibility. The issue is referred to as the black-hole problem in the current work and has received very little attention so far. In this paper, an attempt is made to tackle this intricate problem, and the number of stages in each section of the DWDC is used as adjustment variables to coordinate the relationship between the prefractionator and the main distillation column involved. A simple and yet effective procedure is devised to guide the structural modifications of a given DWDC and the separation of two ternary mixtures of hypothetical components, A, B, and C, and benzene, toluene, and o-xylene are chosen as illustrative examples to evaluate its feasibility and effectiveness. Through steady-state analysis and closed-loop operation studies, it is demonstrated that the black-hole problem can be completely circumvented with the careful adjustment of the number of stages in each section of the DWDC. This outcome gives evidence to the feasibility and effectiveness of the proposed philosophy and indicates a reasonable way to enhance the applicability and flexibilities of the DWDC. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620391

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Synthesis of interplant water-allocation and heat-exchange networks. Part 2 / Rui-Jie Zhou in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14793-14805 Titre : Synthesis of interplant water-allocation and heat-exchange networks. Part 2 : Integrations between fixed flow rate and fixed contaminant-load processes Type de document : texte imprimé Auteurs : Rui-Jie Zhou, Auteur ; Li-Juan Li, Auteur ; Hong-Guang Dong, Auteur Année de publication : 2013 Article en page(s) : pp. 14793-14805 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Pollution Résumé : Part 1 of the series proposes a multiscale state-space superstructure for interplant water-allocation and heat-exchange networks (IWAHENs) design with direct and indirect integration schemes in fixed flow rate (FF) processes (Zhou, R. J.; Li. L. J.; Dong, H. G.; Grossmann, I. E. Synthesis of Interplant Water-Allocation and Heat-Exchange Networks. Part 1: Fixed Flowrate Processes. Ind. Eng. Chem. Res. 2012, 51, 4299). Based on the same superstructure, part 2 of this series extends the IWAHEN integration methods to fixed contaminant-load (FC) processes as well as integration of FF and FC processes. The integrations are performed by solving the corresponding mixed-integer nonlinear programming (MINLP) models based on the multiscale state-space superstructure. Several relevant examples, including both direct and indirect integrations for IWAHENs, are presented to illustrate various aspects of the proposed approach. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620392 [article] Synthesis of interplant water-allocation and heat-exchange networks. Part 2 : Integrations between fixed flow rate and fixed contaminant-load processes [texte imprimé] / Rui-Jie Zhou, Auteur ; Li-Juan Li, Auteur ; Hong-Guang Dong, Auteur . - 2013 . - pp. 14793-14805. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14793-14805 Mots-clés : Pollution Résumé : Part 1 of the series proposes a multiscale state-space superstructure for interplant water-allocation and heat-exchange networks (IWAHENs) design with direct and indirect integration schemes in fixed flow rate (FF) processes (Zhou, R. J.; Li. L. J.; Dong, H. G.; Grossmann, I. E. Synthesis of Interplant Water-Allocation and Heat-Exchange Networks. Part 1: Fixed Flowrate Processes. Ind. Eng. Chem. Res. 2012, 51, 4299). Based on the same superstructure, part 2 of this series extends the IWAHEN integration methods to fixed contaminant-load (FC) processes as well as integration of FF and FC processes. The integrations are performed by solving the corresponding mixed-integer nonlinear programming (MINLP) models based on the multiscale state-space superstructure. Several relevant examples, including both direct and indirect integrations for IWAHENs, are presented to illustrate various aspects of the proposed approach. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620392

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Experimental investigation of methane separation from low-concentration coal mine gas (CH4/N2/O2) by tetra-n-butyl ammonium bromide semiclathrate hydrate crystallization / Dong-liang Zhong in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14806-14813 Titre : Experimental investigation of methane separation from low-concentration coal mine gas (CH4/N2/O2) by tetra-n-butyl ammonium bromide semiclathrate hydrate crystallization Type de document : texte imprimé Auteurs : Dong-liang Zhong, Auteur ; Yang Ye, Auteur ; Chen Yang, Auteur Année de publication : 2013 Article en page(s) : pp. 14806-14813 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Crystallization Coal mine Résumé : In this work, tetra-n-butyl ammonium bromide (TBAB) semiclathrate hydrate was employed in a batch operation to separate CH4 from low-concentration coal mine methane (CMM) gas with a mole composition of 30% CH4, 60% N2, and 10% O2. TBAB semiclathrate hydrate formed from the low-concentration CMM gas has more favorable incipient equilibrium conditions than gas hydrates formed from the same gas mixture. The experiments were carried out at a fixed pressure of 4.0 MPa, three TBAB mole concentrations of 0.29, 0.62, and 1.38 %, and in the temperature range of 274.75―283.35 K. The effects of TBAB concentrations and subcoolings (ΔTsub) on CH4 separation from the low-concentration CMM gas were investigated. The results indicated that CH4 was preferentially incorporated into the hydrate crystals rather than N2 and O2 in the presence of TBAB. The experimental conditions of the TBAB concentration of 1.38%, 4.0 MPa, and ΔTsub = 7.0 K were most favorable for TBAB semiclathrate hydrate to separate CH4 from the low-concentration CMM gas. The CH4 recovery obtained at these conditions was approximately 27%. Compared with CH4 content in the low-concentration CMM gas, the mole fraction of CH4 in TBAB semiclathrate hydrate was increased to 41%. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620393 [article] Experimental investigation of methane separation from low-concentration coal mine gas (CH4/N2/O2) by tetra-n-butyl ammonium bromide semiclathrate hydrate crystallization [texte imprimé] / Dong-liang Zhong, Auteur ; Yang Ye, Auteur ; Chen Yang, Auteur . - 2013 . - pp. 14806-14813. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14806-14813 Mots-clés : Crystallization Coal mine Résumé : In this work, tetra-n-butyl ammonium bromide (TBAB) semiclathrate hydrate was employed in a batch operation to separate CH4 from low-concentration coal mine methane (CMM) gas with a mole composition of 30% CH4, 60% N2, and 10% O2. TBAB semiclathrate hydrate formed from the low-concentration CMM gas has more favorable incipient equilibrium conditions than gas hydrates formed from the same gas mixture. The experiments were carried out at a fixed pressure of 4.0 MPa, three TBAB mole concentrations of 0.29, 0.62, and 1.38 %, and in the temperature range of 274.75―283.35 K. The effects of TBAB concentrations and subcoolings (ΔTsub) on CH4 separation from the low-concentration CMM gas were investigated. The results indicated that CH4 was preferentially incorporated into the hydrate crystals rather than N2 and O2 in the presence of TBAB. The experimental conditions of the TBAB concentration of 1.38%, 4.0 MPa, and ΔTsub = 7.0 K were most favorable for TBAB semiclathrate hydrate to separate CH4 from the low-concentration CMM gas. The CH4 recovery obtained at these conditions was approximately 27%. Compared with CH4 content in the low-concentration CMM gas, the mole fraction of CH4 in TBAB semiclathrate hydrate was increased to 41%. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620393

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Isolation of pharmaceutical intermediates through solid supported evaporation. semicontinuous Operation Mode / Matthaus U. Babler in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14814–14823 Titre : Isolation of pharmaceutical intermediates through solid supported evaporation. semicontinuous Operation Mode Type de document : texte imprimé Auteurs : Matthaus U. Babler, Auteur ; Mebatsion L. Kebede, Auteur ; Raquel Rozada-Sanchez, Auteur Année de publication : 2013 Article en page(s) : pp. 14814–14823 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Solid evaporationi Solating nonvolatile Résumé : Solid supported evaporation (SSE) is a simple, nonselective method for isolating nonvolatile compounds from a solution. The solution is put in contact with porous polymer beads onto which the compound deposits upon evaporation of the solvent. This brings some advantages over direct evaporation to dryness in terms of safety, thermal decomposition, and solid handling, as the loaded beads form a free-flowing granular material that is easily recovered. In this paper, SSE in a semicontinuous operating mode is investigated where the solution is continuously fed to (respectively sprayed over) an agitated bed of dry beads put under vacuum. It is found that under conditions where the solvent evaporation rate is high with respect to the feed rate, high bead loadings can be achieved before extensive sticking of beads and compound to the vessel walls occurs. The type of compound and solvent had little influence on the process performance, and, in cases where this was explored, the bead loading was found to be homogeneous. Based on a balance equation for the solvent fed to the system, a model is developed that results in a simple scale up criterion. The latter was successfully applied for transferring SSE from lab to the kilo lab scale. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301359c [article] Isolation of pharmaceutical intermediates through solid supported evaporation. semicontinuous Operation Mode [texte imprimé] / Matthaus U. Babler, Auteur ; Mebatsion L. Kebede, Auteur ; Raquel Rozada-Sanchez, Auteur . - 2013 . - pp. 14814–14823. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14814–14823 Mots-clés : Solid evaporationi Solating nonvolatile Résumé : Solid supported evaporation (SSE) is a simple, nonselective method for isolating nonvolatile compounds from a solution. The solution is put in contact with porous polymer beads onto which the compound deposits upon evaporation of the solvent. This brings some advantages over direct evaporation to dryness in terms of safety, thermal decomposition, and solid handling, as the loaded beads form a free-flowing granular material that is easily recovered. In this paper, SSE in a semicontinuous operating mode is investigated where the solution is continuously fed to (respectively sprayed over) an agitated bed of dry beads put under vacuum. It is found that under conditions where the solvent evaporation rate is high with respect to the feed rate, high bead loadings can be achieved before extensive sticking of beads and compound to the vessel walls occurs. The type of compound and solvent had little influence on the process performance, and, in cases where this was explored, the bead loading was found to be homogeneous. Based on a balance equation for the solvent fed to the system, a model is developed that results in a simple scale up criterion. The latter was successfully applied for transferring SSE from lab to the kilo lab scale. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301359c

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Vapor-phase adsorption and separation of ethylbenzene and styrene on the metal–organic frameworks MIL-47 and MIL-53(Al) / Tom Remy in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14824-14833 Titre : Vapor-phase adsorption and separation of ethylbenzene and styrene on the metal–organic frameworks MIL-47 and MIL-53(Al) Type de document : texte imprimé Auteurs : Tom Remy, Auteur ; Lina Ma, Auteur ; Michael Maes, Auteur Année de publication : 2013 Article en page(s) : pp. 14824-14833 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorption Résumé : Separation of styrene (ST) from ethylbenzene (EB) remains an industrially relevant challenge in the production of polystyrene. Adsorptive separation with metal—organic frameworks (MOFs) is a potential alternative for the conventional vacuum distillation process. Adsorption and separation of ST and EB on the MOFs MIL-47 and MIL-53(Al) were studied under vapor-phase conditions. ST and EB show traditional type I isotherms on MIL-47. Contrarily, ST adsorption isotherms show steep steps on MIL-53(Al) as a result of the breathing of the flexible MOF upon increased adsorbate pressure. The separation potential of both MOFs was investigated by performing vapor-phase breakthrough experiments at total hydrocarbon partial pressures between 1.14 and 16.4 mbar and temperatures between 35 and 90 °C. ST is preferentially adsorbed on both MOFs. Although the MOFs are isostructural, the evolution of selectivity with temperature and pressure is different for both materials due to the different interaction and separation mechanisms. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620395 [article] Vapor-phase adsorption and separation of ethylbenzene and styrene on the metal–organic frameworks MIL-47 and MIL-53(Al) [texte imprimé] / Tom Remy, Auteur ; Lina Ma, Auteur ; Michael Maes, Auteur . - 2013 . - pp. 14824-14833. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14824-14833 Mots-clés : Adsorption Résumé : Separation of styrene (ST) from ethylbenzene (EB) remains an industrially relevant challenge in the production of polystyrene. Adsorptive separation with metal—organic frameworks (MOFs) is a potential alternative for the conventional vacuum distillation process. Adsorption and separation of ST and EB on the MOFs MIL-47 and MIL-53(Al) were studied under vapor-phase conditions. ST and EB show traditional type I isotherms on MIL-47. Contrarily, ST adsorption isotherms show steep steps on MIL-53(Al) as a result of the breathing of the flexible MOF upon increased adsorbate pressure. The separation potential of both MOFs was investigated by performing vapor-phase breakthrough experiments at total hydrocarbon partial pressures between 1.14 and 16.4 mbar and temperatures between 35 and 90 °C. ST is preferentially adsorbed on both MOFs. Although the MOFs are isostructural, the evolution of selectivity with temperature and pressure is different for both materials due to the different interaction and separation mechanisms. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620395

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Discrete equilibrium data from dynamic column breakthrough experiments / Reza Haghpanah in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14834-14844 Titre : Discrete equilibrium data from dynamic column breakthrough experiments Type de document : texte imprimé Auteurs : Reza Haghpanah, Auteur ; Arvind Rajendran, Auteur ; Shamsuzzaman Farooq, Auteur Année de publication : 2013 Article en page(s) : pp. 14834-14844 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Isotherm Discrete equilibrium data Résumé : A new method for extracting discrete equilibrium data from a set of dynamic column breakthrough experiments is described. Instead of the classical approach where an isotherm model, i.e., a function, is used to describe the equilibrium, this approach represents the isotherm as a set of discrete points. For a given set of discrete fluid phase concentrations, an optimization method is used to determine the corresponding solid loadings that lead to the best-fit prediction of the experimental breakthrough profile. In this work, we develop the algorithm and validate it using single-component case studies, for a variety of isotherm shapes. The practical use of the method is demonstrated by applying it to experimentally measured breakthrough profiles taken from the literature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3015457 [article] Discrete equilibrium data from dynamic column breakthrough experiments [texte imprimé] / Reza Haghpanah, Auteur ; Arvind Rajendran, Auteur ; Shamsuzzaman Farooq, Auteur . - 2013 . - pp. 14834-14844. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14834-14844 Mots-clés : Isotherm Discrete equilibrium data Résumé : A new method for extracting discrete equilibrium data from a set of dynamic column breakthrough experiments is described. Instead of the classical approach where an isotherm model, i.e., a function, is used to describe the equilibrium, this approach represents the isotherm as a set of discrete points. For a given set of discrete fluid phase concentrations, an optimization method is used to determine the corresponding solid loadings that lead to the best-fit prediction of the experimental breakthrough profile. In this work, we develop the algorithm and validate it using single-component case studies, for a variety of isotherm shapes. The practical use of the method is demonstrated by applying it to experimentally measured breakthrough profiles taken from the literature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3015457

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Effect of impurity on the lateral crystal growth of l-alanine / Xiangyu Yang in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14845-14849 Titre : Effect of impurity on the lateral crystal growth of l-alanine : A combined simulation and experimental study Type de document : texte imprimé Auteurs : Xiangyu Yang, Auteur ; Gang Qian, Auteur Année de publication : 2013 Article en page(s) : pp. 14845-14849 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Crystal growth Impurity Résumé : The effects of L-valine on the lateral growth of (011) and (120) surfaces of L-alanine are studied by combining molecular simulation and experimental studies. The growth of the (120) surface is significantly inhibited by L-valine, while the growth of the (011) surface is less affected. An intrinsic impurity effectiveness parameter is proposed by taking into consideration the selectivity of impurities to adsorb on both step and terrace, which explains the different inhibition effects of an impurity on different surfaces. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620397 [article] Effect of impurity on the lateral crystal growth of l-alanine : A combined simulation and experimental study [texte imprimé] / Xiangyu Yang, Auteur ; Gang Qian, Auteur . - 2013 . - pp. 14845-14849. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14845-14849 Mots-clés : Crystal growth Impurity Résumé : The effects of L-valine on the lateral growth of (011) and (120) surfaces of L-alanine are studied by combining molecular simulation and experimental studies. The growth of the (120) surface is significantly inhibited by L-valine, while the growth of the (011) surface is less affected. An intrinsic impurity effectiveness parameter is proposed by taking into consideration the selectivity of impurities to adsorb on both step and terrace, which explains the different inhibition effects of an impurity on different surfaces. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620397

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Visualization of protein fouling inside a hollow fiber ultrafiltration membrane by fluorescent microscopy / Yan Hao in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14850-14858 Titre : Visualization of protein fouling inside a hollow fiber ultrafiltration membrane by fluorescent microscopy Type de document : texte imprimé Auteurs : Yan Hao, Auteur ; Cui Liang, Auteur ; Akihito Moriya, Auteur Année de publication : 2013 Article en page(s) : pp. 14850-14858 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Membrane separation Ultrafiltration Hollow fiber Fouling Résumé : Membrane fouling caused by macromolecular species such as proteins remains a major problem, especially in ultrafiltration processes. In this work, we developed a method of direct observation of protein fouling inside a hollow-fiber membrane using fluorescent microscopy. Fluorescent microscope images showed where proteins accumulated inside the membrane during filtration. Commercially available membranes with differing molecular weight cutoffs had differing geometries of internal protein deposition. Different types of proteins (BSA, casein, and lysozyme) also induced different internal membrane foulings. Poly(vinylidene fluoride) hollow-fiber membranes with and without a skin layer were prepared by phase separation methods, and the present observation method revealed that the structural differences between the membranes significantly affected internal membrane fouling. Finally, the protein-fouled membrane was backwashed with various cleaning agents. The fluorescent microscopic observation visualized the effects of backwashing with the cleaning agents. These results reveal fouling behaviors inside an ultrafiltration hollow-fiber membrane and provide important insights into membrane fouling. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620398 [article] Visualization of protein fouling inside a hollow fiber ultrafiltration membrane by fluorescent microscopy [texte imprimé] / Yan Hao, Auteur ; Cui Liang, Auteur ; Akihito Moriya, Auteur . - 2013 . - pp. 14850-14858. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14850-14858 Mots-clés : Membrane separation Ultrafiltration Hollow fiber Fouling Résumé : Membrane fouling caused by macromolecular species such as proteins remains a major problem, especially in ultrafiltration processes. In this work, we developed a method of direct observation of protein fouling inside a hollow-fiber membrane using fluorescent microscopy. Fluorescent microscope images showed where proteins accumulated inside the membrane during filtration. Commercially available membranes with differing molecular weight cutoffs had differing geometries of internal protein deposition. Different types of proteins (BSA, casein, and lysozyme) also induced different internal membrane foulings. Poly(vinylidene fluoride) hollow-fiber membranes with and without a skin layer were prepared by phase separation methods, and the present observation method revealed that the structural differences between the membranes significantly affected internal membrane fouling. Finally, the protein-fouled membrane was backwashed with various cleaning agents. The fluorescent microscopic observation visualized the effects of backwashing with the cleaning agents. These results reveal fouling behaviors inside an ultrafiltration hollow-fiber membrane and provide important insights into membrane fouling. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620398

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Simultaneous purification of pulchinenoside B4 and B5 from pulsatilla chinensis using macroporous resin and preparative high performance liquid chromatography / Liming Wang in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14859-14866 Titre : Simultaneous purification of pulchinenoside B4 and B5 from pulsatilla chinensis using macroporous resin and preparative high performance liquid chromatography Type de document : texte imprimé Auteurs : Liming Wang, Auteur ; Qiongming Xu, Auteur ; Sheng Su, Auteur Année de publication : 2013 Article en page(s) : pp. 14859-14866 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : HPLC chromatography Macroporosity Purification Résumé : Pulchinenoside B4 and B5 (PB4, PB5) are two major triterpenoid saponins existing in the roots of Pulsatilla chinensis (Bunge) Regel. In this study, a systematic preparative process was developed for the simultaneous purification of PB4 and PB5 from the herb. The performance and separation characteristics of nine types of macroporous resins were critically evaluated. Static absorption/desorption experiments revealed that LX17 belonging to the polyacrylate class possessed superior separation properties. Further dynamic absorption/desorption experiments on LX17 column were conducted to obtain the optimal parameters. To obtain both compounds with high purity, a second stage procedure was developed using preparative reversed-phase high performance liquid chromatography with a dynamic axial compression column system. The separation process was high-efficiency and low-cost, which indicated potential for industrial applications. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620399 [article] Simultaneous purification of pulchinenoside B4 and B5 from pulsatilla chinensis using macroporous resin and preparative high performance liquid chromatography [texte imprimé] / Liming Wang, Auteur ; Qiongming Xu, Auteur ; Sheng Su, Auteur . - 2013 . - pp. 14859-14866. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14859-14866 Mots-clés : HPLC chromatography Macroporosity Purification Résumé : Pulchinenoside B4 and B5 (PB4, PB5) are two major triterpenoid saponins existing in the roots of Pulsatilla chinensis (Bunge) Regel. In this study, a systematic preparative process was developed for the simultaneous purification of PB4 and PB5 from the herb. The performance and separation characteristics of nine types of macroporous resins were critically evaluated. Static absorption/desorption experiments revealed that LX17 belonging to the polyacrylate class possessed superior separation properties. Further dynamic absorption/desorption experiments on LX17 column were conducted to obtain the optimal parameters. To obtain both compounds with high purity, a second stage procedure was developed using preparative reversed-phase high performance liquid chromatography with a dynamic axial compression column system. The separation process was high-efficiency and low-cost, which indicated potential for industrial applications. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620399

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Effects of particle blockage and eccentricity in location on the non-newtonian fluid hydrodynamics around a sphere / Suresh Krishnan in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14867-14883 Titre : Effects of particle blockage and eccentricity in location on the non-newtonian fluid hydrodynamics around a sphere Type de document : texte imprimé Auteurs : Suresh Krishnan, Auteur ; A. Kannan, Auteur Année de publication : 2013 Article en page(s) : pp. 14867-14883 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrodynamics Non Newtonian fluid Résumé : The flow of an incompressible non-Newtonian fluid over an eccentrically located sphere confined in a circular tube was investigated using three-dimensional steady state Computational Fluid Dynamics simulations. Pseudoplastic fluids with different power-law indices of 0.57, 0.76, and 0.94 were considered. The effects of ratio of particle diameter to tube diameter (blockage ratio, BR) and ratio of offset of the sphere position from the tube axis to the tube radius (eccentricity, Ec) on the hydrodynamic phenomena around the sphere are reported over a range of particle Reynolds numbers (Rep). The simulations were carried out in the range (0.1 ≤ Rep ≤ 40, 0.01 ≤ BR ≤ 0.5, and 0.0 ≤ Ec ≤ 0.6). The drag coefficient predictions for an unconfined sphere were found to be sensitive to the value of the consistency index parameter (K) in the viscous flow regime, especially at lower n values. At lower particle Reynolds numbers and centrally located sphere, the enhancement in drag coefficient due to blockage ratio was felt least by the fluid with the lowest n value. Even at higher Rep, higher blockage ratios still could cause significant enhancements in the drag coefficients (∼20%) for centrally located spheres. Irrespective of the power-law index, eccentric location of the sphere caused a decline in the overall drag coefficient due to the dominant influence of the lower hemisphere which was closer to the tube wall. At the highest particle Reynolds numbers, eccentricity, and blockage ratio, asymmetric fluid flow distribution caused opposing effects by decreasing the viscous drag coefficient and increasing the form drag coefficient relative to those obtained with the centrally confined sphere. Sharp variations in the shear rate dependent viscosity at the sphere surface could be associated with boundary layer separation. Wall effects at higher blockage ratio suppressed the boundary layer separation in the case of the fluid with the highest power-law index. Eccentricity also caused accelerated boundary layer separation at the upper hemisphere and absence of boundary layer separation along the lower hemisphere. At lower blockage ratios a maximum in the lift coefficient versus particle Reynolds number was usually observed. This study will be relevant in applications such as aseptic food processing, petroleum well drilling, fluidization, and particle transport in microfluidic devices. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620400 [article] Effects of particle blockage and eccentricity in location on the non-newtonian fluid hydrodynamics around a sphere [texte imprimé] / Suresh Krishnan, Auteur ; A. Kannan, Auteur . - 2013 . - pp. 14867-14883. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14867-14883 Mots-clés : Hydrodynamics Non Newtonian fluid Résumé : The flow of an incompressible non-Newtonian fluid over an eccentrically located sphere confined in a circular tube was investigated using three-dimensional steady state Computational Fluid Dynamics simulations. Pseudoplastic fluids with different power-law indices of 0.57, 0.76, and 0.94 were considered. The effects of ratio of particle diameter to tube diameter (blockage ratio, BR) and ratio of offset of the sphere position from the tube axis to the tube radius (eccentricity, Ec) on the hydrodynamic phenomena around the sphere are reported over a range of particle Reynolds numbers (Rep). The simulations were carried out in the range (0.1 ≤ Rep ≤ 40, 0.01 ≤ BR ≤ 0.5, and 0.0 ≤ Ec ≤ 0.6). The drag coefficient predictions for an unconfined sphere were found to be sensitive to the value of the consistency index parameter (K) in the viscous flow regime, especially at lower n values. At lower particle Reynolds numbers and centrally located sphere, the enhancement in drag coefficient due to blockage ratio was felt least by the fluid with the lowest n value. Even at higher Rep, higher blockage ratios still could cause significant enhancements in the drag coefficients (∼20%) for centrally located spheres. Irrespective of the power-law index, eccentric location of the sphere caused a decline in the overall drag coefficient due to the dominant influence of the lower hemisphere which was closer to the tube wall. At the highest particle Reynolds numbers, eccentricity, and blockage ratio, asymmetric fluid flow distribution caused opposing effects by decreasing the viscous drag coefficient and increasing the form drag coefficient relative to those obtained with the centrally confined sphere. Sharp variations in the shear rate dependent viscosity at the sphere surface could be associated with boundary layer separation. Wall effects at higher blockage ratio suppressed the boundary layer separation in the case of the fluid with the highest power-law index. Eccentricity also caused accelerated boundary layer separation at the upper hemisphere and absence of boundary layer separation along the lower hemisphere. At lower blockage ratios a maximum in the lift coefficient versus particle Reynolds number was usually observed. This study will be relevant in applications such as aseptic food processing, petroleum well drilling, fluidization, and particle transport in microfluidic devices. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620400

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Quantitative structure–property relationship study to predict speed of sound in diverse organic solvents from solvent structural information / Bahram Hemmateenejad in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14884-14891 Titre : Quantitative structure–property relationship study to predict speed of sound in diverse organic solvents from solvent structural information Type de document : texte imprimé Auteurs : Bahram Hemmateenejad, Auteur ; Poorandokht Ilani-Kashkouli, Auteur Année de publication : 2013 Article en page(s) : pp. 14884-14891 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Organic solvent Property structure relationship Résumé : The interaction of solvents with ultrasonic waves is of drastic importance and has been the subject of many studies in recent years. In this study, the effect of solvent structural parameters on the speed of sound in chemical solvents was investigated through a quantitative structure―property relationship (QSPR). Genetic algorithm―multiple linear regression (GA-MLR) analysis was employed to select the most relevant subset of descriptors and, then, to develop the model. The validity of the obtained 10-parameter model was assessed by most widely used validation techniques. The predictive power of the model was evaluated by use of an external data set. The high level of accuracy of results approved the model. According to the model, those solvents that have stronger solvent―solvent interactions can create a more appropriate medium for passing and propagating sound waves and will result in higher speed of sounds. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620401 [article] Quantitative structure–property relationship study to predict speed of sound in diverse organic solvents from solvent structural information [texte imprimé] / Bahram Hemmateenejad, Auteur ; Poorandokht Ilani-Kashkouli, Auteur . - 2013 . - pp. 14884-14891. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14884-14891 Mots-clés : Organic solvent Property structure relationship Résumé : The interaction of solvents with ultrasonic waves is of drastic importance and has been the subject of many studies in recent years. In this study, the effect of solvent structural parameters on the speed of sound in chemical solvents was investigated through a quantitative structure―property relationship (QSPR). Genetic algorithm―multiple linear regression (GA-MLR) analysis was employed to select the most relevant subset of descriptors and, then, to develop the model. The validity of the obtained 10-parameter model was assessed by most widely used validation techniques. The predictive power of the model was evaluated by use of an external data set. The high level of accuracy of results approved the model. According to the model, those solvents that have stronger solvent―solvent interactions can create a more appropriate medium for passing and propagating sound waves and will result in higher speed of sounds. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620401

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Lubricating and waxy esters II / Laziz Bouzidi in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14892-14902 Titre : Lubricating and waxy esters II : Synthesis, crystallization, and melt behavior of branched monoesters Type de document : texte imprimé Auteurs : Laziz Bouzidi, Auteur ; Shaojun Li, Auteur ; Steve Di Biase, Auteur Année de publication : 2013 Article en page(s) : pp. 14892-14902 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Crystallization Résumé : A comprehensive study of branched derivatives of four pure jojoba wax-like esters (JLEs), having 36, 40 (two isomers), and 44 carbons was conducted to elucidate their crystallization and melting behavior. Crystallization and melting characteristics depended strongly on the number of branches, molar mass, and symmetry. The derivatives demonstrated a very strong tendency to form glassy liquids rather than crystal phases and remain liquid-like at very low temperatures. As the number of branches increased, their crystallinity decreased drastically while their glassy phase increased concomitantly with the depression of the onset of crystallization and/or glass transition temperature. A variety of possible transformation paths, ranging from very little polymorphic activity to extremely polymorphic behavior, depending on number of branches, mass, and symmetry were revealed. It is shown that asymmetry plays a large role in the low temperature behavior, rendering the branched derivatives of the asymmetrical JLEs much better candidates for lubricant formulations. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620402 [article] Lubricating and waxy esters II : Synthesis, crystallization, and melt behavior of branched monoesters [texte imprimé] / Laziz Bouzidi, Auteur ; Shaojun Li, Auteur ; Steve Di Biase, Auteur . - 2013 . - pp. 14892-14902. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14892-14902 Mots-clés : Crystallization Résumé : A comprehensive study of branched derivatives of four pure jojoba wax-like esters (JLEs), having 36, 40 (two isomers), and 44 carbons was conducted to elucidate their crystallization and melting behavior. Crystallization and melting characteristics depended strongly on the number of branches, molar mass, and symmetry. The derivatives demonstrated a very strong tendency to form glassy liquids rather than crystal phases and remain liquid-like at very low temperatures. As the number of branches increased, their crystallinity decreased drastically while their glassy phase increased concomitantly with the depression of the onset of crystallization and/or glass transition temperature. A variety of possible transformation paths, ranging from very little polymorphic activity to extremely polymorphic behavior, depending on number of branches, mass, and symmetry were revealed. It is shown that asymmetry plays a large role in the low temperature behavior, rendering the branched derivatives of the asymmetrical JLEs much better candidates for lubricant formulations. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620402

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Approach to Improve Speed of Sound Calculation within PC-SAFT Framework / Xiaodong Liang in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14903–14914 Titre : Approach to Improve Speed of Sound Calculation within PC-SAFT Framework Type de document : texte imprimé Auteurs : Xiaodong Liang, Auteur ; Bjorn Maribo-Mogensen, Auteur ; Kaj Thomsen, Auteur Année de publication : 2013 Article en page(s) : pp. 14903–14914 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Speed sound data parameter estimation Résumé : An extensive comparison of SRK, CPA, and PC-SAFT for the speed of sound in normal alkanes has been performed. The results reveal that PC-SAFT captures the curvature of the speed of sound better than cubic EoS, but the accuracy is not satisfactory. Two approaches have been proposed to improve PC-SAFT’s accuracy for speed of sound: (i) putting speed of sound data into parameter estimation; (ii) putting speed of sound data into both universal constants regression and parameter estimation. The results have shown that the second approach can significantly improve the speed of sound (3.2%) prediction while keeping acceptable accuracy for the primary properties, i.e. vapor pressure (2.1%) and liquid density (1.5%). The two approaches have also been applied to methanol, and both give very good results. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3018127 [article] Approach to Improve Speed of Sound Calculation within PC-SAFT Framework [texte imprimé] / Xiaodong Liang, Auteur ; Bjorn Maribo-Mogensen, Auteur ; Kaj Thomsen, Auteur . - 2013 . - pp. 14903–14914. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14903–14914 Mots-clés : Speed sound data parameter estimation Résumé : An extensive comparison of SRK, CPA, and PC-SAFT for the speed of sound in normal alkanes has been performed. The results reveal that PC-SAFT captures the curvature of the speed of sound better than cubic EoS, but the accuracy is not satisfactory. Two approaches have been proposed to improve PC-SAFT’s accuracy for speed of sound: (i) putting speed of sound data into parameter estimation; (ii) putting speed of sound data into both universal constants regression and parameter estimation. The results have shown that the second approach can significantly improve the speed of sound (3.2%) prediction while keeping acceptable accuracy for the primary properties, i.e. vapor pressure (2.1%) and liquid density (1.5%). The two approaches have also been applied to methanol, and both give very good results. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3018127

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Selective adsorption of methylparaben by submicrosized molecularly imprinted polymer / Minjia Meng in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14915–14924 Titre : Selective adsorption of methylparaben by submicrosized molecularly imprinted polymer : Batch and dynamic flow mode studies Type de document : texte imprimé Auteurs : Minjia Meng, Auteur ; Zhipeng Wang, Auteur ; Linli Ma, Auteur Année de publication : 2013 Article en page(s) : pp. 14915–14924 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorption Polymer Résumé : Highly selective submicrosized molecularly imprinted polymer (SMIPMP) for methylparaben (MP) was synthesized by molecular imprinting technique with a sol–gel process on silica submicroparticles. The prepared SMIPMP was characterized by FT-IR, SEM, TG, and N2 adsorption–desorption techniques. Compared with microsized methylparaben imprinted polymer (MMIPMP) adsorbent, SMIPMP adsorbent with small particle size and high specific surface area showed faster adsorption rate and stronger adsorption capacity for MP. The maximum static adsorption capacity for MP of SMIPMP was 32.68 mg g–1, and the adsorption equilibrium could be reached in 40 min. The SMIPMP adsorbent could be used at least 5 times without significant loss in adsorption capacity. Compared with submicrosized nonimprinted polymer (SNIP), SMIPMP indicated excellent recognition and binding affinity toward MP molecules, whose selectivity coefficients for MP relative to methyl salicylate (MS) and p-hydroxybenzoic acid (p-HB) were 5.664 and 6.129, respectively. The mechanism for static adsorption of MP onto SMIPMP was found to follow Freundlich, Redlich-Peterson isotherm, and pseudo-second-order model. Thomas’ model was applied in the quantitative description and parametrization of the dynamic adsorption of MP to SMIPMP and SNIP, which showed that the linear and nonlinear methods were both suitable to predict the breakthrough curves but the nonlinear method was better. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301890b [article] Selective adsorption of methylparaben by submicrosized molecularly imprinted polymer : Batch and dynamic flow mode studies [texte imprimé] / Minjia Meng, Auteur ; Zhipeng Wang, Auteur ; Linli Ma, Auteur . - 2013 . - pp. 14915–14924. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14915–14924 Mots-clés : Adsorption Polymer Résumé : Highly selective submicrosized molecularly imprinted polymer (SMIPMP) for methylparaben (MP) was synthesized by molecular imprinting technique with a sol–gel process on silica submicroparticles. The prepared SMIPMP was characterized by FT-IR, SEM, TG, and N2 adsorption–desorption techniques. Compared with microsized methylparaben imprinted polymer (MMIPMP) adsorbent, SMIPMP adsorbent with small particle size and high specific surface area showed faster adsorption rate and stronger adsorption capacity for MP. The maximum static adsorption capacity for MP of SMIPMP was 32.68 mg g–1, and the adsorption equilibrium could be reached in 40 min. The SMIPMP adsorbent could be used at least 5 times without significant loss in adsorption capacity. Compared with submicrosized nonimprinted polymer (SNIP), SMIPMP indicated excellent recognition and binding affinity toward MP molecules, whose selectivity coefficients for MP relative to methyl salicylate (MS) and p-hydroxybenzoic acid (p-HB) were 5.664 and 6.129, respectively. The mechanism for static adsorption of MP onto SMIPMP was found to follow Freundlich, Redlich-Peterson isotherm, and pseudo-second-order model. Thomas’ model was applied in the quantitative description and parametrization of the dynamic adsorption of MP to SMIPMP and SNIP, which showed that the linear and nonlinear methods were both suitable to predict the breakthrough curves but the nonlinear method was better. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301890b

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A systematic computer-aided product design and development procedure / Navid Omidbakhsh in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14925-14934 Titre : A systematic computer-aided product design and development procedure : Case of disinfectant formulations Type de document : texte imprimé Auteurs : Navid Omidbakhsh, Auteur ; Thomas A. Duever, Auteur ; Ali Elkamel, Auteur Année de publication : 2013 Article en page(s) : pp. 14925-14934 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Product development Computer aid Résumé : Product formulation design involves selecting a few ingredients from a large set through screening based on several criteria, and using the optimal proportion in the formulation. The limitation in the traditional strategy for chemical product formulation design is to carry out a large number of trials, which in most practical cases, is either economically infeasible or a very slow process. Furthermore, the presence of constraints, sometimes contradictory to some extent, further complicates the formulation design process. Such traditional trial-and-error and one-factor-at-a-time methodologies can be very cumbersome. They can also lead to a slow and high-cost process. The outcome of following such techniques does not usually lead to optimal designs. In this work, a methodology that deals with the complexity of product formulation design problem with contradictory constraints is presented and illustrated in a real case study. This methodology starts with defining needs for a new product and generating ideas. It then screens the candidate ingredients, using design of experiment techniques, and develops a model for each response. It then inverts the models using a nonlinear optimization technique, and obtains an optimal design for the product based on the desired properties. This methodology is proven to be more effective, faster, and less expensive in the development of new products or improvements on the existing ones. Furthermore, the final product is an optimal formulation, with respect to a preset performance measure and desired properties. The procedure is illustrated and tested on the case of disinfectant formulations. The optimized formulation was prepared, tested, and compared to an existing formulation. The optimized formulation faired significantly better than the existing product, in terms of technical and economic preference. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620405 [article] A systematic computer-aided product design and development procedure : Case of disinfectant formulations [texte imprimé] / Navid Omidbakhsh, Auteur ; Thomas A. Duever, Auteur ; Ali Elkamel, Auteur . - 2013 . - pp. 14925-14934. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14925-14934 Mots-clés : Product development Computer aid Résumé : Product formulation design involves selecting a few ingredients from a large set through screening based on several criteria, and using the optimal proportion in the formulation. The limitation in the traditional strategy for chemical product formulation design is to carry out a large number of trials, which in most practical cases, is either economically infeasible or a very slow process. Furthermore, the presence of constraints, sometimes contradictory to some extent, further complicates the formulation design process. Such traditional trial-and-error and one-factor-at-a-time methodologies can be very cumbersome. They can also lead to a slow and high-cost process. The outcome of following such techniques does not usually lead to optimal designs. In this work, a methodology that deals with the complexity of product formulation design problem with contradictory constraints is presented and illustrated in a real case study. This methodology starts with defining needs for a new product and generating ideas. It then screens the candidate ingredients, using design of experiment techniques, and develops a model for each response. It then inverts the models using a nonlinear optimization technique, and obtains an optimal design for the product based on the desired properties. This methodology is proven to be more effective, faster, and less expensive in the development of new products or improvements on the existing ones. Furthermore, the final product is an optimal formulation, with respect to a preset performance measure and desired properties. The procedure is illustrated and tested on the case of disinfectant formulations. The optimized formulation was prepared, tested, and compared to an existing formulation. The optimized formulation faired significantly better than the existing product, in terms of technical and economic preference. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620405

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