Measurement and modeling solubility of aqueous multisolute amino-acid solutions / Jan-Bernd Grosse Daldrup in Industrial & engineering chemistry research, Vol. 49 N° 3 (Fevrier 2010)

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 1395–1401 Titre : Measurement and modeling solubility of aqueous multisolute amino-acid solutions Type de document : texte imprimé Auteurs : Jan-Bernd Grosse Daldrup, Auteur ; Christoph Held, Auteur ; Feelly Ruether, Auteur Année de publication : 2010 Article en page(s) : pp. 1395–1401 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Measurement--Modeling--Solubility--Aqueous--Multisolute--Amino-Acid--Solutions Résumé : The solubilities of the ternary mixtures l-alanine/l-leucine, l-alanine/l-valine, and l-leucine/l-valine in water were measured at 303 and 323 K. The solubilities of seven binary, eight ternary, and one quaternary amino-acid systems were modeled using the PC-SAFT equation of state. For this purpose, new parameters for l-aspartic acid, l-glutamic acid, l-leucine, and l-tyrosine are presented. The model excellently reproduces binary solubility data with a linear temperature-dependent binary interaction parameter for the solute−solvent interaction. PC-SAFT allows for a very good prediction of the solubility behavior of ternary mixtures over a wide range of temperature and concentration. The aqueous mixture with three amino acids is then predicted without any further adjustment with an average relative deviation of 3.34%. ISSN : 0888-5885 [article] Measurement and modeling solubility of aqueous multisolute amino-acid solutions [texte imprimé] / Jan-Bernd Grosse Daldrup, Auteur ; Christoph Held, Auteur ; Feelly Ruether, Auteur . - 2010 . - pp. 1395–1401. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 1395–1401 Mots-clés : Measurement--Modeling--Solubility--Aqueous--Multisolute--Amino-Acid--Solutions Résumé : The solubilities of the ternary mixtures l-alanine/l-leucine, l-alanine/l-valine, and l-leucine/l-valine in water were measured at 303 and 323 K. The solubilities of seven binary, eight ternary, and one quaternary amino-acid systems were modeled using the PC-SAFT equation of state. For this purpose, new parameters for l-aspartic acid, l-glutamic acid, l-leucine, and l-tyrosine are presented. The model excellently reproduces binary solubility data with a linear temperature-dependent binary interaction parameter for the solute−solvent interaction. PC-SAFT allows for a very good prediction of the solubility behavior of ternary mixtures over a wide range of temperature and concentration. The aqueous mixture with three amino acids is then predicted without any further adjustment with an average relative deviation of 3.34%. ISSN : 0888-5885

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Modeling pH and solubilities in aqueous multisolute amino acid solutions / Jan-Bernd Grosse Daldrup in Industrial & engineering chemistry research, Vol. 50 N° 6 (Mars 2011)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 50 N° 6 (Mars 2011) . - pp. 3503–3509 Titre : Modeling pH and solubilities in aqueous multisolute amino acid solutions Type de document : texte imprimé Auteurs : Jan-Bernd Grosse Daldrup, Auteur ; Christoph Held, Auteur ; Gabriele Sadowski, Auteur Année de publication : 2011 Article en page(s) : pp. 3503–3509 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Amino acids Aqueous multisolute Résumé : The solubility of amino acids is highly depending on the prevailing pH value. However, this dependency is neglected in the state-of-the-art modeling of solubilities in multisolute solutions. In order to describe the pH-dependency of the solubilities, the PC-SAFT model is applied to aqueous solutions containing two amino acids accounting for their dissociation/association equilibria. This approach is applied to four ternary mixtures with pronounced pH-dependent solubility behavior allowing for a good description of experimental amino acid solubilities depending on temperature, cosolute concentration, and pH value. The systems considered within this work each contain two amino acids which show big differences in pI, i.e., l-glutamic acid or l/dl-aspartic acid on the one hand and glycine or l-serine on the other hand, respectively. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1010367 [article] Modeling pH and solubilities in aqueous multisolute amino acid solutions [texte imprimé] / Jan-Bernd Grosse Daldrup, Auteur ; Christoph Held, Auteur ; Gabriele Sadowski, Auteur . - 2011 . - pp. 3503–3509. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 6 (Mars 2011) . - pp. 3503–3509 Mots-clés : Amino acids Aqueous multisolute Résumé : The solubility of amino acids is highly depending on the prevailing pH value. However, this dependency is neglected in the state-of-the-art modeling of solubilities in multisolute solutions. In order to describe the pH-dependency of the solubilities, the PC-SAFT model is applied to aqueous solutions containing two amino acids accounting for their dissociation/association equilibria. This approach is applied to four ternary mixtures with pronounced pH-dependent solubility behavior allowing for a good description of experimental amino acid solubilities depending on temperature, cosolute concentration, and pH value. The systems considered within this work each contain two amino acids which show big differences in pI, i.e., l-glutamic acid or l/dl-aspartic acid on the one hand and glycine or l-serine on the other hand, respectively. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1010367

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The interplay between individual and collective knowledge / Joachim Kimmerle in Knowledge management research and practice, Vol. 8 N° 1 (Mars 2010)  

Public ISBD [article]  inKnowledge management research and practice > Vol. 8 N° 1 (Mars 2010) . - pp. 33-44 Titre : The interplay between individual and collective knowledge : Technologies for organisational learning and knowledge building Type de document : texte imprimé Auteurs : Joachim Kimmerle, Auteur ; Ulrike Cress, Auteur ; Christoph Held, Auteur Année de publication : 2011 Article en page(s) : pp. 33-44 Note générale : Management Langues : Anglais (eng) Mots-clés : Collaborative systems Knowledge and information communities management tools Organisational learning Tacit knowledge Index. décimale : 658 Organisation des entreprises. Techniques du commerce Résumé : This article presents a framework model that defines knowledge building as a co-evolution of cognitive and social systems. Our model brings together Nonaka's knowledge-creating theory and Luhmann's systems theory. It is demonstrated how collaborative knowledge building may occur – in an ideal situation – within an organisation, when people interact with each other using shared digital artefacts. For this purpose, three different technologies are introduced as examples: social-tagging systems, pattern-based task-management systems, and wikis. These examples have been chosen to demonstrate that knowledge building can occur with respect to both declarative and procedural knowledge. The differences and similarities between these technologies, as far as their potential for organisational knowledge building is concerned, are discussed in the light of the framework model. DEWEY : 658 ISSN : 1477-8238 En ligne : http://www.palgrave-journals.com/kmrp/journal/v8/n1/index.html [article] The interplay between individual and collective knowledge : Technologies for organisational learning and knowledge building [texte imprimé] / Joachim Kimmerle, Auteur ; Ulrike Cress, Auteur ; Christoph Held, Auteur . - 2011 . - pp. 33-44. Management Langues : Anglais (eng) in Knowledge management research and practice > Vol. 8 N° 1 (Mars 2010) . - pp. 33-44 Mots-clés : Collaborative systems Knowledge and information communities management tools Organisational learning Tacit knowledge Index. décimale : 658 Organisation des entreprises. Techniques du commerce Résumé : This article presents a framework model that defines knowledge building as a co-evolution of cognitive and social systems. Our model brings together Nonaka's knowledge-creating theory and Luhmann's systems theory. It is demonstrated how collaborative knowledge building may occur – in an ideal situation – within an organisation, when people interact with each other using shared digital artefacts. For this purpose, three different technologies are introduced as examples: social-tagging systems, pattern-based task-management systems, and wikis. These examples have been chosen to demonstrate that knowledge building can occur with respect to both declarative and procedural knowledge. The differences and similarities between these technologies, as far as their potential for organisational knowledge building is concerned, are discussed in the light of the framework model. DEWEY : 658 ISSN : 1477-8238 En ligne : http://www.palgrave-journals.com/kmrp/journal/v8/n1/index.html

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