Starch degradation, kinetic model

Where S, G, X, E and Enz are respectively the starch, glucose, cells, ethanol and enzyme concentrations inside the reactor, Si is the starch concentration on the feed, F is the feed flow rate, V is the volume of hquid in the fermentor and (pi, (p2, (ps represent the reaction rates for starch degradation, cells growth and ethanol production, respectively. The unstructured model presented in (Ochoa et al., 2007) is used here as the real plant. The ki (for i=l to 4) kinetic parameters of the model for control were identified by an optimization procedure given in Mazouni et al. (2004), using as error index the mean square error between the state variables of the unstructured model and the model for control. 

Kinetic Model for Degradation of Starch—Plastic Blends mth ControDed-Release Potential... 

The biodegradability of starch in the plastic matrix mainly depends on the accessibility of starch to microbes and on the coimectivity of starch particles each other. Wool and Cole (8) described a simulation model based on percolation theory for predicting accessibility of starch in LDPE to microbial attack and add hydrolysis. This model predicted a percolation threshold at 30% (v/v) starch irrespective of component geometry and other influential factors. Two critical aspects, the bioavailability and the kinetics of the starch hydrolysis in the plastic matrix must be examined before such blends could be applied as controlled release formulation of pestiddes. The goal of this work was to develop a kinetic model describing the degradation and release of starch blended with hydrophobic plastics. 

Kinetic Model for Starch Digestion and Product Release. Before the comprehensive mathematical model could be constructed, some assumptions were made from prior research on polymer degradation (10) (a) the diffusion of both the enzyme and the products in the plastic matrix obeyed Pick s first law, (b) the... 

Degradation mechanisms for polymers exposed to aquatic and terrestrial environments are presented and their significance is discussed in terms of current definitions, standards, polymer materials and biodegradation kinetics in model polymer-starch blends [1],... 

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