Documents disponibles écrits par cet auteur

Predicting the effect of the homogenization pressure on emulsion drop-size distributions / Neha B. Raikar in Industrial & engineering chemistry research, Vol. 50 N° 10 (Mai 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6089–6100 Titre : Predicting the effect of the homogenization pressure on emulsion drop-size distributions Type de document : texte imprimé Auteurs : Neha B. Raikar, Auteur ; Surita R. Bhatia, Auteur ; Michael F. Malone, Auteur Année de publication : 2011 Article en page(s) : pp. 6089–6100 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Homogenization  pressure  Emulsion Résumé : We have previously developed a population balance equation (PBE) model for emulsion drop breakage in a high-pressure homogenizer that incorporated multiple-drop formation within two mechanisms of turbulent drop breakage. The model was found to satisfactorily predict the effects of formulation variables on the drop-size distribution, but the model was not extensible to a range of homogenization pressures. The objective of this paper is to determine the additional model elements necessary to obtain acceptable predictions over a wide range of pressures. The most significant improvements were obtained by increasing the number of daughter drops formed upon breakage from 20 to 150 drops and by introducing a maximum stable diameter, below which drops could not break. Smaller improvements were obtained by introducing terms that describe the loss of energy available for drop breakage due to thermal heating of the sample and homogenizer and by extending the model to account for the effects of surfactant adsorption and deficiency on the interfacial tension. The simultaneous implementation of all five enhancements was shown to produce a 62% improvement over the previous model, as measured by a least-squares objective based on the difference between the measured and predicted drop-size distributions over five homogenization passes and five pressures in the range 250−1250 bar. The resulting model was also validated over a range of oil and surfactant concentrations and shown to provide satisfactory predictions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101818h [article] Predicting the effect of the homogenization pressure on emulsion drop-size distributions [texte imprimé] / Neha B. Raikar, Auteur ; Surita R. Bhatia, Auteur ; Michael F. Malone, Auteur . - 2011 . - pp. 6089–6100. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6089–6100 Mots-clés : Homogenization  pressure  Emulsion Résumé : We have previously developed a population balance equation (PBE) model for emulsion drop breakage in a high-pressure homogenizer that incorporated multiple-drop formation within two mechanisms of turbulent drop breakage. The model was found to satisfactorily predict the effects of formulation variables on the drop-size distribution, but the model was not extensible to a range of homogenization pressures. The objective of this paper is to determine the additional model elements necessary to obtain acceptable predictions over a wide range of pressures. The most significant improvements were obtained by increasing the number of daughter drops formed upon breakage from 20 to 150 drops and by introducing a maximum stable diameter, below which drops could not break. Smaller improvements were obtained by introducing terms that describe the loss of energy available for drop breakage due to thermal heating of the sample and homogenizer and by extending the model to account for the effects of surfactant adsorption and deficiency on the interfacial tension. The simultaneous implementation of all five enhancements was shown to produce a 62% improvement over the previous model, as measured by a least-squares objective based on the difference between the measured and predicted drop-size distributions over five homogenization passes and five pressures in the range 250−1250 bar. The resulting model was also validated over a range of oil and surfactant concentrations and shown to provide satisfactory predictions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101818h

Scheduling in the FMCG industry / Martijn A. H. van Elzakker in Industrial & engineering chemistry research, Vol. 51 N° 22 (Juin 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 22 (Juin 2012) . - pp. 7800–7815 Titre : Scheduling in the FMCG industry : An industrial case study Type de document : texte imprimé Auteurs : Martijn A. H. van Elzakker, Auteur ; Edwin Zondervan, Auteur ; Neha B. Raikar, Auteur Année de publication : 2012 Article en page(s) : pp. 7800–7815 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Scheduling  Industry Résumé : A problem-specific model is presented for the short-term scheduling problem in the Fast Moving Consumer Goods (FMCG) industry. To increase the computational efficiency, the limited intermediate inventory is modeled indirectly by relating mixing and packing intervals. In addition, the model size is reduced by exploiting the process characteristics by dedicating time intervals to product types. The efficiency and flexibility of the formulation is demonstrated using ten examples based on an ice cream scheduling case study. The examples contain 62–73 batches of 8 products that must be produced within a 120-h horizon. All cases can be solved to optimality within 170 s. The addition of a periodic cleaning requirement on the mixing lines significantly increases the complexity of the problem. An algorithm is proposed that solves to optimality within half an hour 9 out of 10 cases with periodic cleaning. For the 10th case the makespan obtained was 0.6% higher than the theoretical minimum makespan. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202106k [article] Scheduling in the FMCG industry : An industrial case study [texte imprimé] / Martijn A. H. van Elzakker, Auteur ; Edwin Zondervan, Auteur ; Neha B. Raikar, Auteur . - 2012 . - pp. 7800–7815. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 22 (Juin 2012) . - pp. 7800–7815 Mots-clés : Scheduling  Industry Résumé : A problem-specific model is presented for the short-term scheduling problem in the Fast Moving Consumer Goods (FMCG) industry. To increase the computational efficiency, the limited intermediate inventory is modeled indirectly by relating mixing and packing intervals. In addition, the model size is reduced by exploiting the process characteristics by dedicating time intervals to product types. The efficiency and flexibility of the formulation is demonstrated using ten examples based on an ice cream scheduling case study. The examples contain 62–73 batches of 8 products that must be produced within a 120-h horizon. All cases can be solved to optimality within 170 s. The addition of a periodic cleaning requirement on the mixing lines significantly increases the complexity of the problem. An algorithm is proposed that solves to optimality within half an hour 9 out of 10 cases with periodic cleaning. For the 10th case the makespan obtained was 0.6% higher than the theoretical minimum makespan. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202106k