Documents disponibles écrits par cet auteur

Cyclodextrin inhibits calcium carbonate crystallization and scaling / Venous Derakhshanian in Industrial & engineering chemistry research, Vol. 51 N° 11 (Mars 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4463-4465 Titre : Cyclodextrin inhibits calcium carbonate crystallization and scaling Type de document : texte imprimé Auteurs : Venous Derakhshanian, Auteur ; Sujit Banerjee, Auteur Année de publication : 2012 Article en page(s) : pp. 4463-4465 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Crystallization Résumé : β-Cyclodextrin inhibits calcium carbonate crystallization and also reduces the degree of scaling on stainless steel surfaces. The rate of crystallization is not affected. The size of the calcium carbonate crystals is reduced by the cyclodextrin. Under the conditions used, the cyclodextrin was effective at concentrations between 5 ppm and 100 ppm. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25655656 [article] Cyclodextrin inhibits calcium carbonate crystallization and scaling [texte imprimé] / Venous Derakhshanian, Auteur ; Sujit Banerjee, Auteur . - 2012 . - pp. 4463-4465. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4463-4465 Mots-clés : Crystallization Résumé : β-Cyclodextrin inhibits calcium carbonate crystallization and also reduces the degree of scaling on stainless steel surfaces. The rate of crystallization is not affected. The size of the calcium carbonate crystals is reduced by the cyclodextrin. Under the conditions used, the cyclodextrin was effective at concentrations between 5 ppm and 100 ppm. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25655656

Factors affecting bubble size on foamed polymer-paperboard composites / Sriram K. Annapragada in Industrial & engineering chemistry research, Vol. 48 N° 8 (Avril 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 8 (Avril 2009) . - pp. 3855–3859 Titre : Factors affecting bubble size on foamed polymer-paperboard composites Type de document : texte imprimé Auteurs : Sriram K. Annapragada, Auteur ; Sujit Banerjee, Auteur Année de publication : 2009 Article en page(s) : pp. 3855–3859 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Foamed  paperboard  Pressure  bubbles  Vaporization Résumé : Foamed paperboard is a composite material with applications in the consumer products industry. The composite comprises a layer of paperboard sandwiched between two polymer films. One film foams upon heating while the other acts as a barrier. Foaming is caused by the vaporization of the small amount of moisture present in the board. The resulting increase in pressure bubbles the heat-softened polymer. During growth, the vapor driving force, which depends on the rate of vaporization, overcomes the opposing sheet resistance. Upon continued heating, the vapor escapes through the molten polymer film and from the sides of the board. Less than 2% of the total initial moisture accumulates inside the foam. The average bubble size is about five times lower than the maximum possible bubble size because of moisture losses. The final bubble size and foam thickness are dictated by the degree of bubble coalescence. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8015413 [article] Factors affecting bubble size on foamed polymer-paperboard composites [texte imprimé] / Sriram K. Annapragada, Auteur ; Sujit Banerjee, Auteur . - 2009 . - pp. 3855–3859. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 8 (Avril 2009) . - pp. 3855–3859 Mots-clés : Foamed  paperboard  Pressure  bubbles  Vaporization Résumé : Foamed paperboard is a composite material with applications in the consumer products industry. The composite comprises a layer of paperboard sandwiched between two polymer films. One film foams upon heating while the other acts as a barrier. Foaming is caused by the vaporization of the small amount of moisture present in the board. The resulting increase in pressure bubbles the heat-softened polymer. During growth, the vapor driving force, which depends on the rate of vaporization, overcomes the opposing sheet resistance. Upon continued heating, the vapor escapes through the molten polymer film and from the sides of the board. Less than 2% of the total initial moisture accumulates inside the foam. The average bubble size is about five times lower than the maximum possible bubble size because of moisture losses. The final bubble size and foam thickness are dictated by the degree of bubble coalescence. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8015413

Polysulfide distribution during kraft pulping / Sujit Banerjee in Industrial & engineering chemistry research, Vol. 49 N° 8 (Avril 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3983–3985 Titre : Polysulfide distribution during kraft pulping Type de document : texte imprimé Auteurs : Sujit Banerjee, Auteur ; Yang, Rallming, Auteur Année de publication : 2010 Article en page(s) : pp. 3983–3985 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Polysulfi  Kraft  Pulping  Kraft  Pul Résumé : Polysulfides increase yield from kraft pulping by selectively oxidizing the reducing end groups of the polysaccharides thereby protecting them from hydrolysis. The principal polysulfide homologue formed in white liquor after addition of elemental sulfur was found to be the S22− species. Analysis of both cooking liquor and wood chips during early cooking suggests that the polysulfide present in the chips degrades more slowly than the fraction dissolved in the bulk liquor. The alkalinity inside the chips is lower than that in the bulk liquor. We propose that the rate of degradation of the polysulfides contained within the chip is correspondingly reduced. As pulping proceeds and the structure of the chips open up, the diffusion barrier across the chip is reduced and the polysulfide concentration in the chip and in the bulk liquor begins to even out. It follows that pre-equilibration of wood chips with polysulfide before pulping may reduce the optimum polysulfide dose. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100176x [article] Polysulfide distribution during kraft pulping [texte imprimé] / Sujit Banerjee, Auteur ; Yang, Rallming, Auteur . - 2010 . - pp. 3983–3985. Industrial Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3983–3985 Mots-clés : Polysulfi  Kraft  Pulping  Kraft  Pul Résumé : Polysulfides increase yield from kraft pulping by selectively oxidizing the reducing end groups of the polysaccharides thereby protecting them from hydrolysis. The principal polysulfide homologue formed in white liquor after addition of elemental sulfur was found to be the S22− species. Analysis of both cooking liquor and wood chips during early cooking suggests that the polysulfide present in the chips degrades more slowly than the fraction dissolved in the bulk liquor. The alkalinity inside the chips is lower than that in the bulk liquor. We propose that the rate of degradation of the polysulfides contained within the chip is correspondingly reduced. As pulping proceeds and the structure of the chips open up, the diffusion barrier across the chip is reduced and the polysulfide concentration in the chip and in the bulk liquor begins to even out. It follows that pre-equilibration of wood chips with polysulfide before pulping may reduce the optimum polysulfide dose. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100176x

Scale inhibition and removal in continuous pulp digesters / Sujit Banerjee in Industrial & engineering chemistry research, Vol. 51 N° 30 (Août 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 30 (Août 2012) . - pp. 10283-10286 Titre : Scale inhibition and removal in continuous pulp digesters Type de document : texte imprimé Auteurs : Sujit Banerjee, Auteur ; Tuan Le, Auteur Année de publication : 2012 Article en page(s) : pp. 10283-10286 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Calcium  carbonate  Pulp  digesters Résumé : Calcium carbonate scaling occurs in the chip feed system and the cooking vessel of continuous digesters in pulp mills, and it arises from the reaction of calcium from wood chips with carbonate in the cooking liquor. Commercial antiscalants are typically expensive and rarely keep the system scale-free. Lignin derivatives have been proposed as antiscalants, because of their ability to chelate calcium, but they have not been adopted commercially. We demonstrate that addition of 1% black liquor to white liquor reduces or prevents calcium scaling, as shown by a simple new test that measures the degree to which scale resists abrasive removal from a metal surface. These findings were validated in a full-scale mill trial, where the black liquor not only inhibited calcium scale formation, but also removed existing scale. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301352j [article] Scale inhibition and removal in continuous pulp digesters [texte imprimé] / Sujit Banerjee, Auteur ; Tuan Le, Auteur . - 2012 . - pp. 10283-10286. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 30 (Août 2012) . - pp. 10283-10286 Mots-clés : Calcium  carbonate  Pulp  digesters Résumé : Calcium carbonate scaling occurs in the chip feed system and the cooking vessel of continuous digesters in pulp mills, and it arises from the reaction of calcium from wood chips with carbonate in the cooking liquor. Commercial antiscalants are typically expensive and rarely keep the system scale-free. Lignin derivatives have been proposed as antiscalants, because of their ability to chelate calcium, but they have not been adopted commercially. We demonstrate that addition of 1% black liquor to white liquor reduces or prevents calcium scaling, as shown by a simple new test that measures the degree to which scale resists abrasive removal from a metal surface. These findings were validated in a full-scale mill trial, where the black liquor not only inhibited calcium scale formation, but also removed existing scale. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301352j

Scanning electron microscopy measurements of the surface roughness of paper / Sujit Banerjee in Industrial & engineering chemistry research, Vol. 48 N° 9 (Mai 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 9 (Mai 2009) . - pp. 4322–4325 Titre : Scanning electron microscopy measurements of the surface roughness of paper Type de document : texte imprimé Auteurs : Sujit Banerjee, Auteur ; Yang, Rallming, Auteur ; Charles E. Courchene, Auteur Année de publication : 2009 Article en page(s) : pp. 4322–4325 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Paper  sheet  X-y  uniformity  Roughness  Scanning  electron  microscopy Résumé : A new approach to the measurement of x−y uniformity of the surface of a paper sheet is described. Scanning electron micrographs are taken of both the top and bottom surfaces of a paper sheet and image-analyzed. The images were converted to grayscale, and the standard deviation of the pixel brightness was called the “SEM roughness index” and calculated for each surface. Both commercial newsprint sheets and handsheets made with kraft, TMP, and recycled fibers were examined. Debonders and cationic polymers were added to some sheets. The addition of debonders increases the index on the top side of the sheet but decreases it on the bottom. This is caused by the movement of fines from the top to the bottom side. The addition of cationic polymers increases the SEM roughness index by increasing the degree of microfloc formation. Samples taken across a reel from a commercial paper machine tend to show a mirror image relationship between the top and bottom surfaces. The SEM roughness index is able to detect subtle changes in sheet structure caused by differences in the mode of addition of polymers used for retaining fines in the sheet. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900029v [article] Scanning electron microscopy measurements of the surface roughness of paper [texte imprimé] / Sujit Banerjee, Auteur ; Yang, Rallming, Auteur ; Charles E. Courchene, Auteur . - 2009 . - pp. 4322–4325. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 9 (Mai 2009) . - pp. 4322–4325 Mots-clés : Paper  sheet  X-y  uniformity  Roughness  Scanning  electron  microscopy Résumé : A new approach to the measurement of x−y uniformity of the surface of a paper sheet is described. Scanning electron micrographs are taken of both the top and bottom surfaces of a paper sheet and image-analyzed. The images were converted to grayscale, and the standard deviation of the pixel brightness was called the “SEM roughness index” and calculated for each surface. Both commercial newsprint sheets and handsheets made with kraft, TMP, and recycled fibers were examined. Debonders and cationic polymers were added to some sheets. The addition of debonders increases the index on the top side of the sheet but decreases it on the bottom. This is caused by the movement of fines from the top to the bottom side. The addition of cationic polymers increases the SEM roughness index by increasing the degree of microfloc formation. Samples taken across a reel from a commercial paper machine tend to show a mirror image relationship between the top and bottom surfaces. The SEM roughness index is able to detect subtle changes in sheet structure caused by differences in the mode of addition of polymers used for retaining fines in the sheet. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900029v