Documents disponibles écrits par cet auteur

Comparison of interfacial forces during post-chemical-mechanical-polishing cleaning / Dedy Ng in Transactions of the ASME . Journal of tribology, Vol. 130 n°2 (Mars/Avril 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of tribology > Vol. 130 n°2 (Mars/Avril 2008) . - 5 p. Titre : Comparison of interfacial forces during post-chemical-mechanical-polishing cleaning Type de document : texte imprimé Auteurs : Dedy Ng, Auteur ; Hong Liang, Auteur Année de publication : 2008 Article en page(s) : 5 p. Note générale : Tribology Langues : Anglais (eng) Résumé : This research investigates the interfacial forces involved in tribological interactions while removing nanosized particles during post-chemical-mechanical polishing cleaning. Surface and interfacial forces are discussed to understand the particle adhesion and subsequent removal through physical and chemical interactions. Approaches include theoretical analysis combined with experimental study. The theoretical analysis was focused on the forces that exist between particles and a substrate. Surface interaction consideration includes applied pressure, frictional force, and hydrodynamic drag. The polishing experiments were carried out on silicon wafers with SiO2 slurry. Cleaning experiments were performed in de-ionized water using a polyvinyl acetal brush to remove particles from a hydrophilic-silicon surface. The fluid-drag force was found to affect the lubricating behavior of cleaning through changing material properties. Values of interfacial forces and their effects on cleaning were discussed along with a lubricating model system. En ligne : http://tribology.asmedigitalcollection.asme.org/article.aspx?articleid=1468024 [article] Comparison of interfacial forces during post-chemical-mechanical-polishing cleaning [texte imprimé] / Dedy Ng, Auteur ; Hong Liang, Auteur . - 2008 . - 5 p. Tribology Langues : Anglais (eng) in Transactions of the ASME . Journal of tribology > Vol. 130 n°2 (Mars/Avril 2008) . - 5 p. Résumé : This research investigates the interfacial forces involved in tribological interactions while removing nanosized particles during post-chemical-mechanical polishing cleaning. Surface and interfacial forces are discussed to understand the particle adhesion and subsequent removal through physical and chemical interactions. Approaches include theoretical analysis combined with experimental study. The theoretical analysis was focused on the forces that exist between particles and a substrate. Surface interaction consideration includes applied pressure, frictional force, and hydrodynamic drag. The polishing experiments were carried out on silicon wafers with SiO2 slurry. Cleaning experiments were performed in de-ionized water using a polyvinyl acetal brush to remove particles from a hydrophilic-silicon surface. The fluid-drag force was found to affect the lubricating behavior of cleaning through changing material properties. Values of interfacial forces and their effects on cleaning were discussed along with a lubricating model system. En ligne : http://tribology.asmedigitalcollection.asme.org/article.aspx?articleid=1468024

Modeling of water-spray application in the forced dispersion of LNG vapor cloud using a combined eulerian–lagrangian approach / Byung Kyu Kim in Industrial & engineering chemistry research, Vol. 51 N° 42 (Octobre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13803–13814 Titre : Modeling of water-spray application in the forced dispersion of LNG vapor cloud using a combined eulerian–lagrangian approach Type de document : texte imprimé Auteurs : Byung Kyu Kim, Auteur ; Dedy Ng, Auteur ; Ray A. Mentzer, Auteur Année de publication : 2012 Article en page(s) : pp. 13803–13814 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : LNG  Eulerian  lagrangian Résumé : The safety and security of liquefied natural gas (LNG) facilities has prompted the need for continued study of LNG mitigation systems. Water-spray curtains are widely recognized as an effective measure for dispersing LNG vapor clouds (Martinsen et al. Hydrocarbon Process. 1977, 56, 260−267). Currently, there are no engineering guidelines available for water-curtain applications in the LNG industry because of a lack of understanding of the complex interactions between the LNG vapor cloud and water droplets. This work applies computational fluid dynamics (CFD) modeling to investigate the dominant mechanisms observed in the forced dispersion of LNG vapor using upward-oriented full-cone spray nozzles. An Eulerian–Lagrangian approach was used for the continuous and discrete phases to simulate the energy and momentum exchange between the two phases. Discussed are the physical parameters that are essential inputs to the CFD simulation of the water spray–LNG system. The prediction results were also validated with the Mary Kay O’Connor Process Safety Center’s LNG outdoor experimental data collected in March 2009 at the Brayton Fire Training Field. On the basis of these findings, dominant mechanisms that govern the effectiveness of water spray in the forced dispersion of LNG vapor clouds are discussed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3003864 [article] Modeling of water-spray application in the forced dispersion of LNG vapor cloud using a combined eulerian–lagrangian approach [texte imprimé] / Byung Kyu Kim, Auteur ; Dedy Ng, Auteur ; Ray A. Mentzer, Auteur . - 2012 . - pp. 13803–13814. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13803–13814 Mots-clés : LNG  Eulerian  lagrangian Résumé : The safety and security of liquefied natural gas (LNG) facilities has prompted the need for continued study of LNG mitigation systems. Water-spray curtains are widely recognized as an effective measure for dispersing LNG vapor clouds (Martinsen et al. Hydrocarbon Process. 1977, 56, 260−267). Currently, there are no engineering guidelines available for water-curtain applications in the LNG industry because of a lack of understanding of the complex interactions between the LNG vapor cloud and water droplets. This work applies computational fluid dynamics (CFD) modeling to investigate the dominant mechanisms observed in the forced dispersion of LNG vapor using upward-oriented full-cone spray nozzles. An Eulerian–Lagrangian approach was used for the continuous and discrete phases to simulate the energy and momentum exchange between the two phases. Discussed are the physical parameters that are essential inputs to the CFD simulation of the water spray–LNG system. The prediction results were also validated with the Mary Kay O’Connor Process Safety Center’s LNG outdoor experimental data collected in March 2009 at the Brayton Fire Training Field. On the basis of these findings, dominant mechanisms that govern the effectiveness of water spray in the forced dispersion of LNG vapor clouds are discussed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3003864

New approach to optimizing the facility siting and layout for fire and explosion scenarios / Seungho Jung in Industrial & engineering chemistry research, Vol. 50 N° 7 (Avril 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 7 (Avril 2011) . - pp. 3928–3937 Titre : New approach to optimizing the facility siting and layout for fire and explosion scenarios Type de document : texte imprimé Auteurs : Seungho Jung, Auteur ; Dedy Ng, Auteur ; Christian Diaz-Ovalle, Auteur Année de publication : 2011 Article en page(s) : pp. 3928–3937 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Optimization Résumé : Accidents involving flammable materials often resulted in a fire or an explosion. In addition to property damages caused by fire/explosion, the concern about the potential of structural collapse on building occupants has become an increasingly emergent. The present work describes a new approach to optimizing facility siting and layout for flammable gas release scenarios, thereby minimizing the consequences of fire and explosion. This approach focuses on integrating quantitative risk analysis in the optimization formulation to obtain the optimal allocation of new facilities based on particular risk criteria derived from accident scenarios. Three different approaches to configure the optimal location of new facilities were used: fixed distance (recommended separation distance), optimized layout by considering the structural damage due to blast overpressures, and, finally, integration of the first two approaches with weighting factors to account for the risk to building occupants and the likelihood of the domino effect. The proposed approach was formulated as a mixed integer nonlinear program (MINLP) problem that determines safe locations of facilities by minimizing the overall cost. Furthermore, the proposed methodology was evaluated using a flame acceleration simulator (FLACS) to consider the congestion and confinement effects in the plant in order to provide substantial guidance for deciding the optimal layout. The outcome of this study can be used as a tool to assess a new or current layout of process plant buildings and to manage fire and explosion risks in the chemical process plant. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101367g [article] New approach to optimizing the facility siting and layout for fire and explosion scenarios [texte imprimé] / Seungho Jung, Auteur ; Dedy Ng, Auteur ; Christian Diaz-Ovalle, Auteur . - 2011 . - pp. 3928–3937. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 7 (Avril 2011) . - pp. 3928–3937 Mots-clés : Optimization Résumé : Accidents involving flammable materials often resulted in a fire or an explosion. In addition to property damages caused by fire/explosion, the concern about the potential of structural collapse on building occupants has become an increasingly emergent. The present work describes a new approach to optimizing facility siting and layout for flammable gas release scenarios, thereby minimizing the consequences of fire and explosion. This approach focuses on integrating quantitative risk analysis in the optimization formulation to obtain the optimal allocation of new facilities based on particular risk criteria derived from accident scenarios. Three different approaches to configure the optimal location of new facilities were used: fixed distance (recommended separation distance), optimized layout by considering the structural damage due to blast overpressures, and, finally, integration of the first two approaches with weighting factors to account for the risk to building occupants and the likelihood of the domino effect. The proposed approach was formulated as a mixed integer nonlinear program (MINLP) problem that determines safe locations of facilities by minimizing the overall cost. Furthermore, the proposed methodology was evaluated using a flame acceleration simulator (FLACS) to consider the congestion and confinement effects in the plant in order to provide substantial guidance for deciding the optimal layout. The outcome of this study can be used as a tool to assess a new or current layout of process plant buildings and to manage fire and explosion risks in the chemical process plant. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101367g

QSPR flash point prediction of solvents using topological indices for application in computer aided molecular design / Suhani J. Patel in Industrial & engineering chemistry research, Vol. 48 N° 15 (Août 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 15 (Août 2009) . - pp. 7378–7387 Titre : QSPR flash point prediction of solvents using topological indices for application in computer aided molecular design Type de document : texte imprimé Auteurs : Suhani J. Patel, Auteur ; Dedy Ng, Auteur ; M. Sam Mannan, Auteur Année de publication : 2009 Article en page(s) : pp. 7378–7387 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Solvents  Computer  aided  molecular  design  Quantitative  structure  property  relationship  Topological  indices Résumé : Incorporating consideration for safety issues while selecting solvents for processes has become crucial in light of the chemical process accidents involving solvents that have taken place in recent years. Computer aided molecular design (CAMD) is a methodology that has been researched recently for designing compounds with required target properties and can be applied for selection of safer solvents as well. An important aspect of this methodology concerns the prediction of properties given the structure of the molecule. This paper utilizes one such emerging method for prediction of a hazardous property, flash point, which is indicative of the flammability of solvents. Quantitative structure property relationship (QSPR) and topological indices have been used in this paper to predict flash point properties of different classes of solvents. Multiple linear regression and back-propagation neural network analysis were used to model the flash point. The neural network model showed higher accuracy (training set, r = 0.948, R2 = 0.898). However, there are certain limitations associated with using QSPR in CAMD which have been discussed and need further work. This paper advances the “forward problem” of CAMD using QSPR which has not been researched extensively in the past. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9000794 [article] QSPR flash point prediction of solvents using topological indices for application in computer aided molecular design [texte imprimé] / Suhani J. Patel, Auteur ; Dedy Ng, Auteur ; M. Sam Mannan, Auteur . - 2009 . - pp. 7378–7387. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 15 (Août 2009) . - pp. 7378–7387 Mots-clés : Solvents  Computer  aided  molecular  design  Quantitative  structure  property  relationship  Topological  indices Résumé : Incorporating consideration for safety issues while selecting solvents for processes has become crucial in light of the chemical process accidents involving solvents that have taken place in recent years. Computer aided molecular design (CAMD) is a methodology that has been researched recently for designing compounds with required target properties and can be applied for selection of safer solvents as well. An important aspect of this methodology concerns the prediction of properties given the structure of the molecule. This paper utilizes one such emerging method for prediction of a hazardous property, flash point, which is indicative of the flammability of solvents. Quantitative structure property relationship (QSPR) and topological indices have been used in this paper to predict flash point properties of different classes of solvents. Multiple linear regression and back-propagation neural network analysis were used to model the flash point. The neural network model showed higher accuracy (training set, r = 0.948, R2 = 0.898). However, there are certain limitations associated with using QSPR in CAMD which have been discussed and need further work. This paper advances the “forward problem” of CAMD using QSPR which has not been researched extensively in the past. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9000794

Study on flame characteristics in aerosols by industrial heat transfer fluids / Peng Lian in Industrial & engineering chemistry research, Vol. 50 N° 12 (Juin 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7644-7652 Titre : Study on flame characteristics in aerosols by industrial heat transfer fluids Type de document : texte imprimé Auteurs : Peng Lian, Auteur ; Dedy Ng, Auteur ; Andres F. Mejia, Auteur Année de publication : 2011 Article en page(s) : pp. 7644-7652 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Aerosols  Flame Résumé : Due to the complexity of aerosol formation and the combustion process, fire and explosion hazards of flammable aerosols formed in the process industry are not fully understood. In this study, the flame propagation process of aerosolized industrial heat transfer fluids was investigated to understand the combustion phenomena in aerosol systems. Experimental observation shows different characteristics of flames propagation in aerosol systems, which are determined by the evaporated fuel vapor in aerosol system prior to encountering the flame and the amount of fuel vapor from droplets evaporating inside flames. Numerical modeling revealed that these factors were mainly determined by aerosol droplet size and velocity. The observed characteristics of the aerosol flames and the nature of continuous fuel evaporation that causes the reduction of droplet sizes suggest that ignition of flammable aerosols in the process plant might create more severe consequences than ignition of vapor mixtures. Results also imply that the aerosol dispersion conditions, as well as its formation conditions in scenarios of industrial fluid release, which determine the droplet size and movement velocity, need to be considered in assessment of fire hazard from the flammable aerosols. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239081 [article] Study on flame characteristics in aerosols by industrial heat transfer fluids [texte imprimé] / Peng Lian, Auteur ; Dedy Ng, Auteur ; Andres F. Mejia, Auteur . - 2011 . - pp. 7644-7652. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7644-7652 Mots-clés : Aerosols  Flame Résumé : Due to the complexity of aerosol formation and the combustion process, fire and explosion hazards of flammable aerosols formed in the process industry are not fully understood. In this study, the flame propagation process of aerosolized industrial heat transfer fluids was investigated to understand the combustion phenomena in aerosol systems. Experimental observation shows different characteristics of flames propagation in aerosol systems, which are determined by the evaporated fuel vapor in aerosol system prior to encountering the flame and the amount of fuel vapor from droplets evaporating inside flames. Numerical modeling revealed that these factors were mainly determined by aerosol droplet size and velocity. The observed characteristics of the aerosol flames and the nature of continuous fuel evaporation that causes the reduction of droplet sizes suggest that ignition of flammable aerosols in the process plant might create more severe consequences than ignition of vapor mixtures. Results also imply that the aerosol dispersion conditions, as well as its formation conditions in scenarios of industrial fluid release, which determine the droplet size and movement velocity, need to be considered in assessment of fire hazard from the flammable aerosols. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239081

Study on the reaction mechanism and kinetics of the thermal decomposition of nitroethane / Qingsheng Wang in Industrial & engineering chemistry research, Vol. 48 N° 18 (Septembre 2009) 

Permalink

Study on the reaction mechanism and kinetics of the thermal decomposition of nitroethane / Qingsheng Wang in Industrial & engineering chemistry research, Vol. 48 N° 18 (Septembre 2009) 

Permalink