Rational design of 3-D porous enzymatic electrodes for the production of gluconic acid in bioelectrochemical system

The focus of this research is on rational design of porous enzymatic electrodes as biocatalysts for gluconic acid production

Non-linear frequency response analysis of the kinetics of electrochemical reactions: a case study – ferrocyanide oxidation kinetics

In general, electrochemical (EC) systems are non-linear, which means they respond nonlinearly to a frequency-dependent periodic input perturbation of high amplitude imposed around a steady-state. In addition, the kinetics of EC reactions are quite complex and different rivalling model presentations can be formulated for certain EC reaction. While standard electrochemical methods (steady-state and electrochemical impedance spectroscopy) showed low sensitivity towards the model discrimination, non-linear frequency response analysis (NLFRA) of EC kinetics can appear advantageous for this purpose. In this work, NLFRA is applied in experimental and theoretical study of ferrocyanide oxidation as a model EC reaction.Belgrade, Serbia, June 6-10, 2010Related to the published paper in the Proceedings of the Second Regional Symposium on Electrochemistry South-East Europe, [http://cer.ihtm.bg.ac.rs/handle/123456789/3539

Non-linear frequency response analysis of the kinetics of electrochemical reactions: a case study – ferrocyanide oxidation kinetics

In general, electrochemical (EC) systems are non-linear, which means they respond nonlinearly to a frequency-dependent periodic input perturbation of high amplitude imposed around a steady-state. In addition, the kinetics of EC reactions are quite complex and different rivalling model presentations can be formulated for certain EC reaction. While standard electrochemical methods (steady-state and electrochemical impedance spectroscopy) showed low sensitivity towards the model discrimination, non-linear frequency response analysis (NLFRA) of EC kinetics can appear advantageous for this purpose. In this work, NLFRA is applied in experimental and theoretical study of ferrocyanide oxidation as a model EC reaction.Belgrade, Serbia, June 6-10, 2010Related to the published paper in the Proceedings of the Second Regional Symposium on Electrochemistry South-East Europe, [http://cer.ihtm.bg.ac.rs/handle/123456789/3539

Non-linear frequency response analysis of the kinetics of electrochemical reactions: a case study – ferrocyanide oxidation kinetics

In general, electrochemical (EC) systems are non-linear, which means they respond nonlinearly to a frequency-dependent periodic input perturbation of high amplitude imposed around a steady-state. In addition, the kinetics of EC reactions are quite complex and different rivalling model presentations can be formulated for certain EC reaction. While standard electrochemical methods (steady-state and electrochemical impedance spectroscopy) showed low sensitivity towards the model discrimination, non-linear frequency response analysis (NLFRA) of EC kinetics can appear advantageous for this purpose. In this work, NLFRA is applied in experimental and theoretical study of ferrocyanide oxidation as a model EC reaction.Belgrade, Serbia, June 6-10, 2010Related to the [http://cer.ihtm.bg.ac.rs/handle/123456789/3538

Light-Powered Reactivation of Flagella and Contraction of Microtubule Networks: Toward Building an Artificial Cell

Artificial systems capable of self-sustained movement with self-sufficient energy are of high interest with respect to the development of many challenging applications, including medical treatments, but also technical applications. The bottom-up assembly of such systems in the context of synthetic biology is still a challenging task. In this work, we demonstrate the biocompatibility and efficiency of an artificial light-driven energy module and a motility functional unit by integrating light-switchable photosynthetic vesicles with demembranated flagella. The flagellar propulsion is coupled to the beating frequency, and dynamic ATP synthesis in response to illumination allows us to control beating frequency of flagella in a light-dependent manner. In addition, we verified the functionality of light-powered synthetic vesicles in in vitro motility assays by encapsulating microtubules assembled with force-generating kinesin-1 motors and the energy module to investigate the dynamics of a contractile filamentous network in cell-like compartments by optical stimulation. Integration of this photosynthetic system with various biological building blocks such as cytoskeletal filaments and molecular motors may contribute to the bottom-up synthesis of artificial cells that are able to undergo motor-driven morphological deformations and exhibit directional motion in a light-controllable fashion.R.A., V.N., E.B., I.G., and A.G. acknowledge support from the European Union’s Horizon 2020 research and innovation programme under grant agreement MAMI No. 766007. C.K., A.B., E.B., K.S., I.G., T.V.K., and A.G. thank MaxSynBio Consortium, which is jointly funded by the Federal Ministry of Education and Research of Germany and the Max Planck Societ

Editorial on Special Issue Electrolysis Processes

Renewable energies such as solar, hydro or wind power are in principal abundant but subjected to strong fluctuations [...

Computer-Aided Nonlinear Frequency Response Method for Investigating the Dynamics of Chemical Engineering Systems

The Nonlinear Frequency Response (NFR) method is a useful Process Systems Engineering tool for developing experimental techniques and periodic processes that exploit the system nonlinearity. The basic and most time-consuming step of the NFR method is the derivation of frequency response functions (FRFs). The computer-aided Nonlinear Frequency Response (cNFR) method, presented in this work, uses a software application for automatic derivation of the FRFs, thus making the NFR analysis much simpler, even for systems with complex dynamics. The cNFR application uses an Excel user-friendly interface for defining the model equations and variables, and MATLAB code which performs analytical derivations. As a result, the cNFR application generates MATLAB files containing the derived FRFs in a symbolic and algebraic vector form. In this paper, the software is explained in detail and illustrated through: (1) analysis of periodic operation of an isothermal continuous stirred-tank reactor with a simple reaction mechanism, and (2) experimental identification of electrochemical oxygen reduction reaction

Rapid Multi-Objective Optimization of Periodically Operated Processes Based on the Computer-Aided Nonlinear Frequency Response Method

The dynamic optimization of promising forced periodic processes has always been limited by time-consuming and expensive numerical calculations. The Nonlinear Frequency Response (NFR) method removes these limitations by providing excellent estimates of any process performance criteria of interest. Recently, the NFR method evolved to the computer-aided NFR method (cNFR) through a user-friendly software application for the automatic derivation of the functions necessary to estimate process improvement. By combining the cNFR method with standard multi-objective optimization (MOO) techniques, we developed a unique cNFR-MOO methodology for the optimization of periodic operations in the frequency domain. Since the objective functions are defined with entirely algebraic expressions, the dynamic optimization of forced periodic operations is extraordinarily fast. All optimization parameters, i.e., the steady-state point and the forcing parameters (frequency, amplitudes, and phase difference), are determined rapidly in one step. This gives the ability to find an optimal periodic operation around a sub-optimal steady-state point. The cNFR-MOO methodology was applied to two examples and is shown as an efficient and powerful tool for finding the best forced periodic operation. In both examples, the cNFR-MOO methodology gave conditions that could greatly enhance a process that is normally operated in a steady state

Evaluation of Electrochemical Process Improvement Using the Computer-Aided Nonlinear Frequency Response Method: Oxygen Reduction Reaction in Alkaline Media

The intensification of an electrochemical process by forced periodic operation was studied for the first time using the computer-aided Nonlinear Frequency Response method. This method enabled the automatic generation of frequency response functions and the DC components (Faradaic rectification) of the cost (overpotential) and benefit (current density) indicators. The case study, oxygen reduction reaction, was investigated both experimentally and theoretically. The results of the cost-benefit indicator analysis show that forced periodic change of electrode potential can be superior when compared to the steady-state regime for specific operational parameters. When the electrode rotation rate is changed periodically, the process will always deteriorate as the dynamic operation will inevitably lead to the thickening of the diffusion layer. This phenomenon is explained both from a mathematical and a physical point of view