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Effect of altitude on the essential oil constituents of artemisia roxburghiana besser var. purpurascens (Jacq.) hook / Flora Haider in The journal of essential oil research, Vol. 21 N° 4 (Juillet/Août 2009) 

Public ISBD [article]  in The journal of essential oil research > Vol. 21 N° 4 (Juillet/Août 2009) . - pp. 303-304 Titre : Effect of altitude on the essential oil constituents of artemisia roxburghiana besser var. purpurascens (Jacq.) hook Type de document : texte imprimé Auteurs : Flora Haider, Auteur ; Narendra Kumar, Auteur ; S. Banerjee Article en page(s) : pp. 303-304 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Artemisia  roxburghiana  var.  purpurascens  Asteraceae  Essential  oil  composition  α-thujone  Borneol  β-caryophyllene  Eugenol  Altitude  variation Index. décimale : 646 Résumé : Mature vegetative plants of Artemisia roxburghiana Besser var. purpurascens (Jacq.) Hook were collected from Mussoorie (2205 m), Bhatwari (1218 m) and Bhaldana (850 m) from Garhwal Himalayas and their essential oils were isolated and subjected to GC and GC/MS analysis. The oil yield was lowest (0.2%) in the plants collected from the relatively higher altitude of Mussoorie; it was rich in borneol (21.2%) followed by linalyl acetate (7.4%) and α-humulene (6.7%). The oils from plants collected from the lower altitudes of Bhatwari and Bhaldana yielded higher percentage of oils (0.8–0.85%) which were dominated by β-caryophyllene (16.3%, 18.4%) followed by α-thujone (12.0%) in the former and eugenol (16.2%) in the later. En ligne : http://www.jeoronline.com/archive/detail/42#top [article] Effect of altitude on the essential oil constituents of artemisia roxburghiana besser var. purpurascens (Jacq.) hook [texte imprimé] / Flora Haider, Auteur ; Narendra Kumar, Auteur ; S. Banerjee . - pp. 303-304. Génie Chimique Langues : Anglais (eng) in The journal of essential oil research > Vol. 21 N° 4 (Juillet/Août 2009) . - pp. 303-304 Mots-clés : Artemisia  roxburghiana  var.  purpurascens  Asteraceae  Essential  oil  composition  α-thujone  Borneol  β-caryophyllene  Eugenol  Altitude  variation Index. décimale : 646 Résumé : Mature vegetative plants of Artemisia roxburghiana Besser var. purpurascens (Jacq.) Hook were collected from Mussoorie (2205 m), Bhatwari (1218 m) and Bhaldana (850 m) from Garhwal Himalayas and their essential oils were isolated and subjected to GC and GC/MS analysis. The oil yield was lowest (0.2%) in the plants collected from the relatively higher altitude of Mussoorie; it was rich in borneol (21.2%) followed by linalyl acetate (7.4%) and α-humulene (6.7%). The oils from plants collected from the lower altitudes of Bhatwari and Bhaldana yielded higher percentage of oils (0.8–0.85%) which were dominated by β-caryophyllene (16.3%, 18.4%) followed by α-thujone (12.0%) in the former and eugenol (16.2%) in the later. En ligne : http://www.jeoronline.com/archive/detail/42#top

Effect of seasons and drying on the essential oil composition of leaf in ocimum kilimandscharicum guerke / Narendra Kumar in The journal of essential oil research, Vol. 21 N° 5 (Septembre/Octobre 2009) 

Public ISBD [article]  in The journal of essential oil research > Vol. 21 N° 5 (Septembre/Octobre 2009) . - pp. 400-402 Titre : Effect of seasons and drying on the essential oil composition of leaf in ocimum kilimandscharicum guerke Type de document : texte imprimé Auteurs : Narendra Kumar, Auteur ; Rajani Shukla, Auteur ; C. S. Chanotiya, Auteur Article en page(s) : pp. 400-402 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Ocimum  kilimandscharicum  Lamiaceae  Essential  oil  composition  Camphor  1,8-cineole  Drying  effect Index. décimale : 646 Résumé : The effect of seasons (winter and summer) and drying on the yield and composition of essential oil obtained from the leaves of Ocimum kilimandscharicum, cultivated at the subtropical conditions of North India, was examined by combined GC and GC/MS analysis. This chemotype was found to be rich in camphor (winter 48.9%, summer 58.9%), 1,8-cineole (winter 22.2%, summer 14.8%), and limonene (winter 5.5%, summer 5.6%). The yield of oil was observed to be more in summer (0.8%) than in winter (0.6%). On shade drying of the leaves, no effect was observed in the yield of oil in winter season. However, in summer, yield was slightly reduced on drying (from 0.8% to 0.6%). Camphor, the major constituent of the oil, showed slight degradation in quantity during drying in both winter and summer seasons. DEWEY : 665 ISSN : 1041-2905 En ligne : http://www.jeoronline.com/archive/detail/42#top [article] Effect of seasons and drying on the essential oil composition of leaf in ocimum kilimandscharicum guerke [texte imprimé] / Narendra Kumar, Auteur ; Rajani Shukla, Auteur ; C. S. Chanotiya, Auteur . - pp. 400-402. Génie Chimique Langues : Anglais (eng) in The journal of essential oil research > Vol. 21 N° 5 (Septembre/Octobre 2009) . - pp. 400-402 Mots-clés : Ocimum  kilimandscharicum  Lamiaceae  Essential  oil  composition  Camphor  1,8-cineole  Drying  effect Index. décimale : 646 Résumé : The effect of seasons (winter and summer) and drying on the yield and composition of essential oil obtained from the leaves of Ocimum kilimandscharicum, cultivated at the subtropical conditions of North India, was examined by combined GC and GC/MS analysis. This chemotype was found to be rich in camphor (winter 48.9%, summer 58.9%), 1,8-cineole (winter 22.2%, summer 14.8%), and limonene (winter 5.5%, summer 5.6%). The yield of oil was observed to be more in summer (0.8%) than in winter (0.6%). On shade drying of the leaves, no effect was observed in the yield of oil in winter season. However, in summer, yield was slightly reduced on drying (from 0.8% to 0.6%). Camphor, the major constituent of the oil, showed slight degradation in quantity during drying in both winter and summer seasons. DEWEY : 665 ISSN : 1041-2905 En ligne : http://www.jeoronline.com/archive/detail/42#top

Essential oil profile of natural-temperate and domesticated-subtropical artemisia myriantha wall.ex bess. var. pleiocephala (Pamp.) ling. plants / G. D. Bagchi in The journal of essential oil research, Vol. 21 N°1 (Janvier/Février 2009) 

Public ISBD [article]  in The journal of essential oil research > Vol. 21 N°1 (Janvier/Février 2009) . - pp. 43-45 Titre : Essential oil profile of natural-temperate and domesticated-subtropical artemisia myriantha wall.ex bess. var. pleiocephala (Pamp.) ling. plants Type de document : texte imprimé Auteurs : G. D. Bagchi, Auteur ; Flora Haider, Auteur ; Narendra Kumar, Auteur Article en page(s) : pp. 43-45 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Artemisia  myriantha  var.  pleiocephala  Asteraceae  Essential  oil  composition  Limonene  Chrysanthenone  Camphor Index. décimale : 646 Résumé : Artemisia myriantha var. pleiocephala plants collected from the temperate Garhwal region of Western Himalayas were domesticated in the subtropical conditions of North Indian plains. Considerable changes were observed in the oil constituents of the plant after domestication from temperate conditions to subtropical conditions. In the naturally growing temperate plants, major constituents of the oil were chrysanthenone (7.3%) followed by δ-cadinene (5.7%) and 1,8,cineole (5.3%) during flowering. After domestication at subtropical conditions of Lucknow, although the major constituent of the oil remained chrysanthenone, its quantity increased considerably (15.0–29.1%) during flowering. Another important constituent of the oil of the domesticated plants during flowering was limonene (6.1–15.1%). However, during the vegetative stage, camphor (74.9%) was its major constituent. DEWEY : 665 ISSN : 1041-2905 En ligne : http://www.jeoronline.com/archive/detail/42#top [article] Essential oil profile of natural-temperate and domesticated-subtropical artemisia myriantha wall.ex bess. var. pleiocephala (Pamp.) ling. plants [texte imprimé] / G. D. Bagchi, Auteur ; Flora Haider, Auteur ; Narendra Kumar, Auteur . - pp. 43-45. Génie Chimique Langues : Anglais (eng) in The journal of essential oil research > Vol. 21 N°1 (Janvier/Février 2009) . - pp. 43-45 Mots-clés : Artemisia  myriantha  var.  pleiocephala  Asteraceae  Essential  oil  composition  Limonene  Chrysanthenone  Camphor Index. décimale : 646 Résumé : Artemisia myriantha var. pleiocephala plants collected from the temperate Garhwal region of Western Himalayas were domesticated in the subtropical conditions of North Indian plains. Considerable changes were observed in the oil constituents of the plant after domestication from temperate conditions to subtropical conditions. In the naturally growing temperate plants, major constituents of the oil were chrysanthenone (7.3%) followed by δ-cadinene (5.7%) and 1,8,cineole (5.3%) during flowering. After domestication at subtropical conditions of Lucknow, although the major constituent of the oil remained chrysanthenone, its quantity increased considerably (15.0–29.1%) during flowering. Another important constituent of the oil of the domesticated plants during flowering was limonene (6.1–15.1%). However, during the vegetative stage, camphor (74.9%) was its major constituent. DEWEY : 665 ISSN : 1041-2905 En ligne : http://www.jeoronline.com/archive/detail/42#top

Preparation and characterization of alumina - based microreactors for application in methyl chloride synthesis / Sabrina A. Schmidt in Industrial & engineering chemistry research, Vol. 51 N° 12 (Mars 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4545–4555 Titre : Preparation and characterization of alumina - based microreactors for application in methyl chloride synthesis Type de document : texte imprimé Auteurs : Sabrina A. Schmidt, Auteur ; Narendra Kumar, Auteur ; Biao Zhang, Auteur Année de publication : 2012 Article en page(s) : pp. 4545–4555 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Microreactors  Alumina  catalyst Résumé : Microreactor platelets were coated with an alumina catalyst for use in methyl chloride synthesis. The coating was extensively characterized regarding its uniformity, thickness, and stability by using SEM, confocal microscopy, and EDX. The influence of the platelet pretreatment on the coating stability was investigated with different stability tests. A straightforward method to obtain a stable and uniform coating was developed, and the coated platelets were used for the synthesis of methyl chloride. The performance of the microreactor was compared with a tubular fixed bed reactor. The results obtained with both reactors were comparable, but the microreactor allows a rapid catalytic screening with a low consumption of chemicals. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202922x [article] Preparation and characterization of alumina - based microreactors for application in methyl chloride synthesis [texte imprimé] / Sabrina A. Schmidt, Auteur ; Narendra Kumar, Auteur ; Biao Zhang, Auteur . - 2012 . - pp. 4545–4555. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4545–4555 Mots-clés : Microreactors  Alumina  catalyst Résumé : Microreactor platelets were coated with an alumina catalyst for use in methyl chloride synthesis. The coating was extensively characterized regarding its uniformity, thickness, and stability by using SEM, confocal microscopy, and EDX. The influence of the platelet pretreatment on the coating stability was investigated with different stability tests. A straightforward method to obtain a stable and uniform coating was developed, and the coated platelets were used for the synthesis of methyl chloride. The performance of the microreactor was compared with a tubular fixed bed reactor. The results obtained with both reactors were comparable, but the microreactor allows a rapid catalytic screening with a low consumption of chemicals. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202922x

Skeletal isomerization of butene in fixed beds. 1. experimental investigation and structure-performance effects / Matias Kangas in Industrial & engineering chemistry research, Vol. 47 n°15 (Août 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°15 (Août 2008) . - p. 5402–5412 Titre : Skeletal isomerization of butene in fixed beds. 1. experimental investigation and structure-performance effects Type de document : texte imprimé Auteurs : Matias Kangas, Auteur ; Narendra Kumar, Auteur ; Elina Harlin, Auteur Année de publication : 2008 Article en page(s) : p. 5402–5412 Note générale : Bibliogr. p. 5412 Langues : Anglais (eng) Mots-clés : Skeletal  isomerization  --  structure-performance;  Butene Résumé : An experimental investigation of structure-performance effects in zeolite catalyzed skeletal isomerization has been carried out. Two structurally different, medium-pore-size zeolites (H-TON and H-FER) with similar acidities were compared in butene skeletal isomerization. While both catalysts proved to be efficient in the test reaction, their deactivation behavior differed substantially. H-FER exhibited significantly higher initial isobutene yields and selectivities, and the catalyst performance was also more stable with time-on-stream. H-TON, on the other hand, needed prolonged operation times in order to achieve product distributions comparable to those of H-FER. The predominant route to isobutene was found to be the monomolecular one, with the bimolecular paths of butene largely responsible for byproduct formation. H-TON was more selective toward disproportionation and, owing to its slightly larger pore dimensions, hydrogen transfer products. H-TON was also observed to be less sensitive to feed reactant than H-FER was, confirming previous theoretically calculated structure effects. Coke belonging to both aliphatic and aromatic families was detected over both zeolites, although the coke formed on H-FER was overall heavier and more aromatic in nature. The tested zeolites could be regenerated by burning of the carbonaceous deposits in air, and both catalysts regained almost all of their initial activities. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800061q [article] Skeletal isomerization of butene in fixed beds. 1. experimental investigation and structure-performance effects [texte imprimé] / Matias Kangas, Auteur ; Narendra Kumar, Auteur ; Elina Harlin, Auteur . - 2008 . - p. 5402–5412. Bibliogr. p. 5412 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°15 (Août 2008) . - p. 5402–5412 Mots-clés : Skeletal  isomerization  --  structure-performance;  Butene Résumé : An experimental investigation of structure-performance effects in zeolite catalyzed skeletal isomerization has been carried out. Two structurally different, medium-pore-size zeolites (H-TON and H-FER) with similar acidities were compared in butene skeletal isomerization. While both catalysts proved to be efficient in the test reaction, their deactivation behavior differed substantially. H-FER exhibited significantly higher initial isobutene yields and selectivities, and the catalyst performance was also more stable with time-on-stream. H-TON, on the other hand, needed prolonged operation times in order to achieve product distributions comparable to those of H-FER. The predominant route to isobutene was found to be the monomolecular one, with the bimolecular paths of butene largely responsible for byproduct formation. H-TON was more selective toward disproportionation and, owing to its slightly larger pore dimensions, hydrogen transfer products. H-TON was also observed to be less sensitive to feed reactant than H-FER was, confirming previous theoretically calculated structure effects. Coke belonging to both aliphatic and aromatic families was detected over both zeolites, although the coke formed on H-FER was overall heavier and more aromatic in nature. The tested zeolites could be regenerated by burning of the carbonaceous deposits in air, and both catalysts regained almost all of their initial activities. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800061q