Modeling and Optimization of Lactic Acid Synthesis by the Alkaline Degradation of Fructose in a Batch Reactor

The present work deals with the determination of the optimal operating conditions of lactic acid synthesis by the alkaline degradation of fructose. It is a complex transformation for which detailed knowledge is not available. It is carried out in a batch or semi-batch reactor. The ‘‘Tendency Modeling’’ approach, which consists of the development of an approximate stoichiometric and kinetic model, has been used. An experimental planning method has been utilized as the database for model development. The application of the experimental planning methodology allows comparison between the experimental and model response. The model is then used in an optimization procedure to compute the optimal process. The optimal control problem is converted into a nonlinear programming problem solved using the sequencial quadratic programming procedure coupled with the golden search method. The strategy developed allows simultaneously optimizing the different variables, which may be constrained. The validity of the methodology is illustrated by the determination of the optimal operating conditions of lactic acid production

Bran Size Distribution at Milling and Mechanical and Biochemical Characterization of Common Wheat Grain Outer Layers: A Relationship Assessment

International audienceMechanical properties of wheat grain outer layers from common wheat (Triticum aestivum L.) cultivars known to display distinct milling behavior were analyzed using uniaxial tension tests. Tensile modulus and strain to rupture of the tissues distinguished between the wheat cultivars. Values of strain to rupture were related to coarse bran size generated by grain milling, a characteristic that distinguishes the two hardness classes. As content of an aleurone marker in total or first break flour was also related to coarse bran size, extensibility of wheat grain outer layers' could be a key parameter to explain the observed tissue mechanical behavior and thus distribution of the aleurone layer content in flours. As tissue mechanical properties are generally linked to the cell wall biochemical composition and structure, analysis of the main wheat outer layers' cell wall compounds was undertaken to establish relationships with the differences observed in mechanical properties. No clear correlation could be found with one of the wheat outer layers' component but involvement of the outer layers' cell wall structure in the tissues behavior at milling was confirmed

Une methode de decouplage pour des simulations aeroacoustiques de turbomachines

Communication to : 38eme colloque d'aerodynamique appliquee AAAF, Arcachon (France), 07-08 octobre 2002Available from INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.2002 n.193 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

Identification of acute malnutrition in children in Cambodia requires both mid upper arm circumference and weight-for-height to offset gender bias of each indicator

Malnutrition remains a serious health problem in Cambodia with over 10% of children less than five years of age suffering from acute malnutrition. In addition to the presence of nutritional edema, two indicators are recommended by the World Health Organization for the diagnosis of acute malnutrition: weight-for-height Z-scores (WHZ; with acute malnutrition defined as WHZ < -2 Z-score) and mid-upper arm circumference (MUAC, with acute malnutrition defined as MUAC < 12.5 cm). Earlier, we showed that WHZ and MUAC identified different subgroups of children with acute malnutrition. To explore factors associated with both indicators of acute malnutrition, we analyzed baseline data from a longitudinal study in three provinces in Cambodia: Phnom Penh (capital, urban environment), Kratie (rural province), and Ratanakiri (hilly, rural province). Data was available for 4381 children below 30 months of age. Malnutrition rates were higher in the two rural provinces than in the capital. Although both MUAC and WHZ showed gender bias, with MUAC identifying more girls, and WHZ identifying more boys with acute malnutrition, the gender effect was strongest for MUAC. The gender bias of MUAC diminished with older age, but remained significant up to 30 months of age. Only using both MUAC and WHZ as indicators resulted in gender neutral identification of acute malnutrition. WHZ alone always identified more children with acute malnutrition than MUAC alone. In Phnom Penh, MUAC alone identified only 11% with acute malnutrition in addition to WHZ. To conclude, both MUAC and WHZ showed gender bias in this cohort of Cambodian children. In Cambodia, implementation of a MUAC-only or a WHZ-only program for the identification of acute malnutrition would be unethical as it will lead to many children remaining undiagnosed