Modeling and Optimization of M-cresol Isopropylation for Obtaining N-thymol: Combining a Hybrid Artificial Neural Network with a Genetic Algorithm

The application of a hybrid framework based on the combination, artificial neural network-genetic algorithm (ANN-GA), for n-thymol synthesis modeling and optimization has been developed. The effects of molar ratio propylene/cresol (X1), catalyst mass (X2) and temperature (X3) on n-thymol selectivity Y1 and m-cresol conversion Y2 were studied. A 3-8-2 ANN model was found to be very suitable for reaction modeling. The multiobjective optimization, led to optimal operating conditions (0.55 ≤X1≤0.77; 1.773 g ≤ X2 ≤1.86 g; 289.74 °C ≤ X3 ≤291.33 °C) representing good solutions for obtaining high n-thymol selectivity and high m-cresol conversion. This optimal zone corresponded to n-thymol selectivity and m-cresol conversion ranging respectively in the interval [79.3; 79.5]% and [13.4 %; 23.7]%. These results were better than those obtained with a sequential method based on experimental design for which, optimum conditions led to n-thymol selectivity and m-cresol conversion values respectively equal to 67%and 11%. The hybrid method ANN-GA showed its ability to solve complex problems with a good fitting

Conceiving of an Electrochemical Cell for In Situ Hydrodynamic Approach

International audienceIn the purpose of in situ control of hydrodynamic influence on electrochemical processes, a cell jet device has been conceived and characterized. This cell was sensitive to parameters that are the jet tube diameter, and its height versus the working electrode. So, the three hydrodynamic flow modes have been established from the non dimensional Reynolds number. From the use of this cell for the study of co deposition from the Ni/SiC system with a WATT bath, it was shown that the turbulent flow to favor more embedment of SiC particles in the nickel matrix. It also noted an influence of the flow mode and SiC particles on the working current

Etude de la Migration Globale et de l\'Etancheite de Quelques Emballages Plastiques Fabriques en Côte d\'Ivoire

In this study we have placed in a prominent position of the important part of plastic films used as packing for aliment quality conservation. The migrations phenomena between plastic films and aliment on the one hand and air diffusion through film on the other hand have been studied. We have shown that these phenomena are responsible of nutritional and organoleptic deterioration of aliment. To limit these phenomena we have found that it is necessary to use thick plastic film and conduct the conservation at obscurity. Keywords: Global migration, plastic films permeability, simulation, plastic packing. Résumé Dans cette étude nous avons mis en évidence l\'importance des films plastiques utilisés en Côte d\'Ivoire comme emballage dans la conservation des aliments. Les phénomènes de migration entre les films plastiques et les aliments d\'une part et la diffusion de l\'air atmosphérique à travers les micro pores au sein des films d\'autre part ont été étudiés. Il ressort de ces investigations que ces phénomènes sont responsables de la détérioration de la valeur nutritionnelle et organoleptique des aliments. Pour limiter ces altérations, nous avons montré qu\'il est nécessaire d\'utiliser des emballages plus épais et une conservation à l\'obscurité. Mots clés : Migration globale, perméabilité des films plastiques, simulation, emballage plastique (Af. J. of Science and Technology: 2002 3(2): 76-83

Cocoa Butter Color Development during Processing

Abstract: Color parameters were measured using a CM-2002 Minolta Spectrocolorimeter. Lightness varied from its lowest value of 77.68 to its highest value of 79.60 with coefficients of variation less than 1%. Lightness was statistically (p<0.05) the same for filtration and clarification; and for drying and deodorization. There was no significant difference in greenness from filtration through drying, although the highest greenness (a = -1.18) was obtained after deodorization. Yellowness was statistically equal at filtration (b = 31.34) and clarification (b = 31.19); at washing (b = 33.08) and drying (b = 33.02). Results showed that the spectrocolorimeter was consistent and the step of washing yielded the lightest cocoa butter

Industrial Brewery Modelling by Using Artificial Neural Network

Fermentation is a complex phenomenon well studied which still provides challenges to brewers. In this study, artificial neural network, precisely multi layer perceptron and recurrent one were utilised for modelling either static (yeast quantity to add to wort for fermentation) or dynamic (fermentation process) phenomena. In both cases, the simulated responses are very close to the observed ones with residual biases inferior to 4.5%. Thus, ANN models present good predictive ability confirming the suitability of ANN for industrial process modelling