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Murviel-lès-Montpellier, France

Charnomordic B.,Montpellier SupAgro | David R.,CESAME | Dochain D.,CESAME | Hilgert N.,Montpellier SupAgro | And 3 more authors.
Mathematical and Computer Modelling of Dynamical Systems

In this article, two modelling approaches are proposed for winemaking fermentations. The first one is largely based on the first principle modelling approach and considers the main yeast physiological mechanisms. The model accurately predicts the fermentation kinetics of more than 80% of a large number of experiments performed with 20 wine yeast strains, 69 musts and different fermentation conditions. Thanks to the wide domain of validity of the model, a simulator based on this model coupled to a thermal model was developed to help winemakers to optimize tank management. It predicts the end of the fermentation and changes in the rate of fermentation but furthermore includes an optimization module based on fuzzy logic which allows, via temperature profiles and nitrogen addition strategies, to decrease the duration of fermentation and the energy requirements at winery scale according to user specifications. The objective of the second modelling approach is the development of a mathematical model of the fermentation process including some minority by-products known as characteristic flavour compounds. It refers to metabolic engineering and accounts for the intracellular behaviour of the yeast Saccharomyces cerevisiae by using approaches like the metabolic flux analysis (MFA) and the elementary flux modes (EFMs). A state of the art describes the application of these methods in the restrained field of winemaking/ fermentation conditions and underlines the potential of such approaches. © 2010 Taylor & Francis. Source

Musbah I.,Sirte University | Ciceron D.,LSPC | Garcia F.,UMR 1083 SPO | Saboni A.,Boulevard Of Luniversite | Alexandrova S.,LaTEP
Desalination and Water Treatment

Nowadays, the water resource contamination by nitrates and pesticides is a real problem for drinking water production. Together with conventional methods (active carbon adsorption, ozone oxidation), membrane processes like ultrafiltration, reverse osmosis, and nanofiltration are progressively developing due to their lower cost. This study is focused on the ability of nitrates elimination by two flat sheets of negatively charged nanofiltration membranes: NF and OPMN-K. Experiments were carried out on laboratory equipment in batch circulation at 20°C. Transmembrane pressures were varied between 10 and 25 bars, and the impact on nitrates rejection was characterized. Then, the effects of the nitrate concentration and those of the nitrate salt associated cations (Na+, K+, and Ca2+) on nitrate retention were studied. Moreover, the interactions between mono and divalent ions in nitrate rejection in complex solutions and particularly in synthetic water were also studied. At last, the influence of one typical pesticide metabolite, the desethylatrazine, on nitrates retention was also investigated. © 2015 Balaban Desalination Publications. All rights reserved. Source

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