No abstract

Ce travail fait référence à un procédé automatisé pour l'élaboration du pain de sucre à partir du jus de canne à sucre. Les caractéristiques du produit traditionnel sont maintenues tout en veillant à conserver ses qualités intrinsèques qui en font un aliment naturel, peu altéré par ce procédé technique. Un procédé semi-continu a été développé pour élaborer le pain de sucre. Le procédé se subdivise en 3 étapes principales : l'extraction du jus de canne, l'épuration et la concentration du jus, enfin le moulage du pain de sucre. La dureté et la texture du produit fini sont les paramètres majeurs qui conditionnent la qualité du produit. Les fluctuations des concentrations en sucres réducteurs directs SRD influent significativement sur les paramètres dureté et texture. Ces derniers demeurent les indicateurs majeurs de critère de qualité du pain de sucre. Cette étude est un descriptif détaillé du procédé d'élaboration du pain de sucre dont la qualité dépend étroitement de la concentration en SRD tout au long de la chaîne de fabrication. Les corrélations entre les concentrations SRD et les paramètres qualité y sont également développés.

The phosphate series of Sidi Chennane (Morocco) is frequently affected by sterile bodies called “disturbances” causing many problems during the mining operation. The quantification of these bodies is thus considered as a crucial step for the OCP mining engineers. In following this research, we propose the fractal dimension as a new and simple efficient tool to analyze the disturbed areas. The work was carried out on geoelectrical maps of a study area of 50 hectares located in the northern part of the Sidi Chennane deposit. Fractal dimension was used as a representative parameter for examining the disturbed areas by using the box-counting method. The end result shows a strong linkage between the rate of the disturbances and the corresponding fractal dimension. This may have an important implication to quantify the disturbances and get a precise phosphate reserves estimate.

No abstract

Recovering and purifying organic solvents during chemical and pharmaceutical synthesis has great economic and environmental importance. Water-alcohol mixture pervaporation was investigated using a pervaporation cell and hydrophobic membranes. This work studied polydimethylsiloxane (PDMS) membrane performance and hydrophobic membranes for removing propanol from aqueous mixtures. PDMS is recognised as being alcohol permselective during pervaporation. It was also observed that water was transferred through a hydrophobic membrane as water’s molecular size is smaller than that of propanol. A laboratory-scale pervaporation unit was used for studying this membrane’s separation characteristic in terms of pervaporation flux and selectivity for feeds containing up to water mass and 30°C-50°C. Total propanol/water flux was observed to vary as operating temperature increased. Although PDMS membranes presented good characteristics for separating water/propanol mixtures, the separation factor and pervaporation flow decreased as water content in the feed increased. The tested membrane was found to be very efficient for water concentrations of less than 0.3, corresponding to total flux transfer maximum.