Glucose sensor based on nanostructured carbon electrode with immobilized PQQ-containing glucose dehydrogenase: Construction, experimental study and mathematical modeling

Oxidized graphite (OG) has been prepared by carrying out the synthesis of graphene in the alkaline media using K3[Fe(CN)6] as the oxidizing agent. This synthesis protocol allowed us to obtain and further to apply the OG as an effective electrode material for the reagentless enzyme electrode in which electron transfer between electrode and enzyme active site proceeds directly, without any additional mediators. Direct electron transfer in this bioelectrocatalytic system has been achieved from the active site of pyrroloquinoline quinone-containing glucose dehydrogenase (PQQ-GDH) to the nanostructurized carbon electrode surface. The numerical modeling of biosensor made possible to determine several structural and kinetic parameters of the sensor constructed. Our model of PQQ-GDH-based biosensor is built under three main assumptions. First, we assume that the electron transfer between enzyme active center and OG proceeds via the electron hopping mechanism, and therefore the rate of this reaction depends on the diffusion coefficient of an electron in OG layer. Second, enzyme is immobilized, and its diffusion coefficient is assumed to be zero. Finally, after the reaction with substrate, enzyme needs to be regenerated by the oxidized functionalities of OG

The modeling of LED's disposition.

The goal of this work is to construct the scheme of constructing light - emitting diodes system. The mathematical model was written for a light-emitting lamp. The finite technique was used for the discretization of mathematical model

Mokslininkų tarpuniversitetinis bendradarbiavimas pandemijos metu nenutrūksta

Kauno technologijos universitetasVilniaus universitetasVytauto Didžiojo universitetasŽemės ūkio akademij

Nitrate removal in woodchip denitrification bioreactor – an approach combining mathematical modelling and PI control

A mathematical model of nitrate removal in woodchip denitrification bioreactor based on field experiment measurements was developed in this study. The approach of solving inverse problem for nonlinear system of differential convection-reaction equations was applied to optimize the efficiency of nitrate removal depending on bioreactor’s length and flow rate. The approach was realized through the developed algorithm containing a nonlocal condition with an incorporated PI controller. This allowed to adjust flow rate for varying inflow nitrate concentrations by using PI controller. The proposed model can serve as a useful tool for bioreactor design. The main outcome of the model is a mathematical relationship intended for bioreactor length selection when nitrate concentration at the inlet and the flow rate are known. Custom software was developed to solve the system of differential equations aiming to ensure the required nitrate removal efficiency