Mathematical modeling, non-linear investigations and experimental verification of biochemical processes.

摘要

Mathematical modeling based on rigorous integrated description of any process is a fast, efficient and economical way of gaining insight into the complex process, especially biochemical processes. This dissertation which is divided into four parts presents the mathematical modeling, non-linear investigation and experimental verification of four biochemical processes.; First two parts concentrate on the mathematical modeling, extensive non-linear analysis and experimental verification of the fuel ethanol production processes. Experimentally verified model was utilized to simulate the behavior of ethanol fermentation from glucose. Extensive non-linear analysis of the model was carried out for continuous fermentor(s) with/without ethanol removing membranes, with/without cell/sugar separation and recycle to explore complex behaviors such as static/dynamic bifurcations and chaotic behavior. Conditions were explored to maximize the sugar conversion and ethanol yield/productivity. Various batch and continuous lab experiments were carried out to confirm the existence of static and dynamic bifurcation behavior. Another process (simultaneous saccharification and fermentation or SSF) used for conversion of lignocellulosic biomass directly into ethanol is also modeled. This model depicts the kinetics of the SSF which incorporates the enzymatic hydrolysis, microbial reaction and cell growth kinetics for different substrates. Critical experiments were performed to determine the key model parameters using the multi-response nonlinear regression analysis.; Third part of dissertation concentrates on the modeling and non-linear investigation of the acetylcholine (ACh) neurotransmitter. The research is directed towards the formulation and use of available kinetics information into a diffusion-reaction model in order to simulate in-vivo ACh associated enzymes behavior. This work is a preliminary step towards deeper understanding of the actual ACh neurocycle, its bifurcation/chaotic characteristics and their relation to cholinergic diseases.; The fourth and final part of dissertation proposes the mathematical modeling of a hybrid growth (suspended and attached biomass) domestic wastewater treatment unit which can achieve improvement in the hydraulic capacity as well as the organic capacity. A detailed mathematical model was developed for the hybrid growth reactor as well as the clarifier. The heterogeneous model takes into consideration the mass transfer resistances and diffusion of substrates into the attached biofilm. The model parameters will be estimated utilizing the data obtained from a pilot plant for such a treatment system which is built at Zenein WWTP south of Cairo, Egypt.