Documents disponibles écrits par cet auteur

Boiling and two-phase flow phenomena of refrigerant-based nanofluids / Lixin Cheng in International journal of refrigeration, Vol. 36 N° 2 (N° spécial) (Mars 2013) 

Public ISBD [article]  in International journal of refrigeration > Vol. 36 N° 2 (N° spécial) (Mars 2013) . - pp. 421–446 Titre : Boiling and two-phase flow phenomena of refrigerant-based nanofluids : fundamentals, applications and challenges Titre original : Ebullition et phénomènes d'écoulement diphasique des nanofluides à base de frigorigènes : principes de base, applications et défis Type de document : texte imprimé Auteurs : Lixin Cheng, Auteur ; Lei Liu, Auteur Année de publication : 2013 Article en page(s) : pp. 421–446 Note générale : Refrigeration Langues : Anglais (eng) Mots-clés : Refrigerant-based  nanofluids;  Two-phase  flow;  Pool  boiling;  Flow  boiling;  Condensation;  Heat  transfer;  Flow  patterns;  Pressure  drop;  Correlation;  Prediction  methods;  Nanoparticle;  Nanolubricant;  Mechanism;  Review Résumé : The study of refrigerant-based nanofluid boiling and two-phase flow phenomena is still in its infancy. This field of research provides many opportunities to study new frontiers but also poses great challenges. To summarize the current status of research in this newly developing interdisciplinary field and to identify the future research needs as well, this paper presents a comprehensive review of nucleate pool boiling, flow boiling, condensation and two-phase flow of refrigerant-based nanofluids. The effects of nanolubricants on boiling and two phase flow phenomena are presented as well. Furthermore, studies of applications and challenges of refrigerant-based nanofluids are presented and future research needs are identified. For the limited studies done so far, there are some controversies from one study to another. Conclusions and contradictions on the available refrigerant-based studies of physical properties, boiling and two phase flow are presented. According to this review, it has been realized that the physical properties have significant effects on the refrigerant-based nanofluid boiling and two-phase flow characteristics but the lack of the accurate knowledge of these physical properties has greatly limited the study in this interdisciplinary field. Furthermore, the limited available experiments and quite contradictive results have limited the understanding of the fundamentals of boiling and two phase flow phenomena. Flow regimes are very important in understanding the phenomena but less investigated so far. Apparently it is still a long way to go to achieve systematic fundamental knowledge and theory in the relevant subject. Therefore, effort should be made to contribute to the physical property database of nanofluids as a first priority. Secondly, systematic accurate experiments and flow regime observations on boiling and two-phase flow phenomena under a wide range of test conditions and nanofluid types should be emphasized to understand the fundamentals. Finally, physical mechanisms and prediction methods for boiling heat transfer and two phase flow characteristics should be targeted and applied research should also be focused on in the future. En ligne : http://www.sciencedirect.com/science/article/pii/S014070071200309X [article] Boiling and two-phase flow phenomena of refrigerant-based nanofluids = Ebullition et phénomènes d'écoulement diphasique des nanofluides à base de frigorigènes : principes de base, applications et défis : fundamentals, applications and challenges [texte imprimé] / Lixin Cheng, Auteur ; Lei Liu, Auteur . - 2013 . - pp. 421–446. Refrigeration Langues : Anglais (eng) in International journal of refrigeration > Vol. 36 N° 2 (N° spécial) (Mars 2013) . - pp. 421–446 Mots-clés : Refrigerant-based  nanofluids;  Two-phase  flow;  Pool  boiling;  Flow  boiling;  Condensation;  Heat  transfer;  Flow  patterns;  Pressure  drop;  Correlation;  Prediction  methods;  Nanoparticle;  Nanolubricant;  Mechanism;  Review Résumé : The study of refrigerant-based nanofluid boiling and two-phase flow phenomena is still in its infancy. This field of research provides many opportunities to study new frontiers but also poses great challenges. To summarize the current status of research in this newly developing interdisciplinary field and to identify the future research needs as well, this paper presents a comprehensive review of nucleate pool boiling, flow boiling, condensation and two-phase flow of refrigerant-based nanofluids. The effects of nanolubricants on boiling and two phase flow phenomena are presented as well. Furthermore, studies of applications and challenges of refrigerant-based nanofluids are presented and future research needs are identified. For the limited studies done so far, there are some controversies from one study to another. Conclusions and contradictions on the available refrigerant-based studies of physical properties, boiling and two phase flow are presented. According to this review, it has been realized that the physical properties have significant effects on the refrigerant-based nanofluid boiling and two-phase flow characteristics but the lack of the accurate knowledge of these physical properties has greatly limited the study in this interdisciplinary field. Furthermore, the limited available experiments and quite contradictive results have limited the understanding of the fundamentals of boiling and two phase flow phenomena. Flow regimes are very important in understanding the phenomena but less investigated so far. Apparently it is still a long way to go to achieve systematic fundamental knowledge and theory in the relevant subject. Therefore, effort should be made to contribute to the physical property database of nanofluids as a first priority. Secondly, systematic accurate experiments and flow regime observations on boiling and two-phase flow phenomena under a wide range of test conditions and nanofluid types should be emphasized to understand the fundamentals. Finally, physical mechanisms and prediction methods for boiling heat transfer and two phase flow characteristics should be targeted and applied research should also be focused on in the future. En ligne : http://www.sciencedirect.com/science/article/pii/S014070071200309X

Exotemplating synthesis of nitrogen - doped carbon materials with hierarchically porous structure and their application for lysozyme adsorption / Gao-Song Shao in Chemical engineering journal, Vol. 174 N° 1 (Octobre 2011) 

Public ISBD [article]  in Chemical engineering journal > Vol. 174 N° 1 (Octobre 2011) . - pp. 452–460 Titre : Exotemplating synthesis of nitrogen - doped carbon materials with hierarchically porous structure and their application for lysozyme adsorption Type de document : texte imprimé Auteurs : Gao-Song Shao, Auteur ; Lei Liu, Auteur ; Tian-Yi Ma, Auteur Année de publication : 2012 Article en page(s) : pp. 452–460 Note générale : Génie chimique Langues : Anglais (eng) Mots-clés : Hierarchical  porosity  Exotemplating  Nitrogen-doping  Carbon  Vitamin  B6  Lysozyme  adsorption Résumé : Nitrogen-doped carbon materials with hierarchically porous structure were prepared by employing meso-/macroporous titania (MMT) as exotemplate with the use of Vitamin B6 (VB6) as both the carbon precursor and the nitrogen source for elemental doping. The synthesized materials were characterized by N2 sorption, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The obtained N-doped carbon materials have a multi-scaled porous hierarchy with pore sizes ranging from micropores, mesopores to macropores, and their morphology can be easily tuned through a simple adjustment of the weight ratio of VB6 to MMT. The different chemical state (pyridine-like N, quaternary N and oxidized N) and the content of nitrogen were analyzed by XPS. The prepared materials were used as the adsorbents for lysozyme. The effect of nitrogen doping on the lysozyme adsorption capability was investigated by comparison of the lysozyme adsorption behavior on the nitrogen-doped and nitrogen-free carbon materials with a similar pore structure. It was found that the nitrogen-containing carbon had higher adsorption capacity of lysozyme than that of the nitrogen-free carbons. En ligne : http://www.sciencedirect.com/science/article/pii/S1385894711010345 [article] Exotemplating synthesis of nitrogen - doped carbon materials with hierarchically porous structure and their application for lysozyme adsorption [texte imprimé] / Gao-Song Shao, Auteur ; Lei Liu, Auteur ; Tian-Yi Ma, Auteur . - 2012 . - pp. 452–460. Génie chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 174 N° 1 (Octobre 2011) . - pp. 452–460 Mots-clés : Hierarchical  porosity  Exotemplating  Nitrogen-doping  Carbon  Vitamin  B6  Lysozyme  adsorption Résumé : Nitrogen-doped carbon materials with hierarchically porous structure were prepared by employing meso-/macroporous titania (MMT) as exotemplate with the use of Vitamin B6 (VB6) as both the carbon precursor and the nitrogen source for elemental doping. The synthesized materials were characterized by N2 sorption, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The obtained N-doped carbon materials have a multi-scaled porous hierarchy with pore sizes ranging from micropores, mesopores to macropores, and their morphology can be easily tuned through a simple adjustment of the weight ratio of VB6 to MMT. The different chemical state (pyridine-like N, quaternary N and oxidized N) and the content of nitrogen were analyzed by XPS. The prepared materials were used as the adsorbents for lysozyme. The effect of nitrogen doping on the lysozyme adsorption capability was investigated by comparison of the lysozyme adsorption behavior on the nitrogen-doped and nitrogen-free carbon materials with a similar pore structure. It was found that the nitrogen-containing carbon had higher adsorption capacity of lysozyme than that of the nitrogen-free carbons. En ligne : http://www.sciencedirect.com/science/article/pii/S1385894711010345

Integrated biological and electrochemical oxidation treatment for high toxicity pesticide pollutant / Lei Liu in Industrial & engineering chemistry research, Vol. 49 N° 12 (Juin 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5496–5503 Titre : Integrated biological and electrochemical oxidation treatment for high toxicity pesticide pollutant Type de document : texte imprimé Auteurs : Lei Liu, Auteur ; Guohua Zhao, Auteur ; Yaning Pang, Auteur Année de publication : 2010 Article en page(s) : pp. 5496–5503 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : integrated  biological  oxidation  Electrochemical  oxidation  Toxicity  pesticide Résumé : A novel integrated biological and electrochemical oxidation (BEO) process was proposed for the treatment of biorefractory pesticide wastewater with high toxicity. An acetamiprid solution of 1000 mg L−1 was used as the target pollutant. Its biodegradability in terms of biochemical oxygen demand in a 5-d test period (BOD5)/total organic carbon (TOC) was only 0.0057, presenting its high biorefractory property. In the BEO system with boron-doped diamond electrode (BDD), the value of BOD5/TOC was improved to 1.17 and the toxicity was reduced by 40% in 3 h, maintaining the activity of microorganisms on a biofilter at an appropriate level. The intermediates (mainly small molecule carboxylic acids) produced in the electrochemical process served as nutrients for the microorganisms and then were biodegraded, while the biodegradation of these intermediates further enhanced the electrochemical oxidation of the original pollutant. The synergy of electrochemical and biological processes improved the removal of acetamiprid and TOC with higher efficiency and lower energy consumption. For the same TOC removal, the mineralization current efficiency (MCE) in the BEO was at least 40% higher than that in a single electrochemical oxidation (EO), and the energy consumption was only 53.3 (kW h)/m3 in the BEO in 5 h, which was 44.5% lower than that in the EO. The BEO technique is an efficient method for the treatment of highly concentrated and biorefractory wastewater. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100333v [article] Integrated biological and electrochemical oxidation treatment for high toxicity pesticide pollutant [texte imprimé] / Lei Liu, Auteur ; Guohua Zhao, Auteur ; Yaning Pang, Auteur . - 2010 . - pp. 5496–5503. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5496–5503 Mots-clés : integrated  biological  oxidation  Electrochemical  oxidation  Toxicity  pesticide Résumé : A novel integrated biological and electrochemical oxidation (BEO) process was proposed for the treatment of biorefractory pesticide wastewater with high toxicity. An acetamiprid solution of 1000 mg L−1 was used as the target pollutant. Its biodegradability in terms of biochemical oxygen demand in a 5-d test period (BOD5)/total organic carbon (TOC) was only 0.0057, presenting its high biorefractory property. In the BEO system with boron-doped diamond electrode (BDD), the value of BOD5/TOC was improved to 1.17 and the toxicity was reduced by 40% in 3 h, maintaining the activity of microorganisms on a biofilter at an appropriate level. The intermediates (mainly small molecule carboxylic acids) produced in the electrochemical process served as nutrients for the microorganisms and then were biodegraded, while the biodegradation of these intermediates further enhanced the electrochemical oxidation of the original pollutant. The synergy of electrochemical and biological processes improved the removal of acetamiprid and TOC with higher efficiency and lower energy consumption. For the same TOC removal, the mineralization current efficiency (MCE) in the BEO was at least 40% higher than that in a single electrochemical oxidation (EO), and the energy consumption was only 53.3 (kW h)/m3 in the BEO in 5 h, which was 44.5% lower than that in the EO. The BEO technique is an efficient method for the treatment of highly concentrated and biorefractory wastewater. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100333v