Optimal Input Design for Model Discrimination

Abstract: The paper presents a methodology for optimal input design for model discrimination from experimental data. To allow analytical solutions, the method, using Pontryagin’s maximum principle, is initially developed for non-linear single state systems that are affine in their joint input. The method is demonstrated on a fed-batch reactor case study with zero-, first-order and Monod kinetics

Exploring the feasibility of a novel municipal wastewater treatment system via dynamic plant-wide simulation

A plant-wide simulation study is presented in which we investigated the feasibility of a novel centralized municipal wastewater treatment system design as previously proposed by Khiewwijit et al. (2015). This design includes processes as bioflocculation (BF), anaerobic digestion (AD), partial nitritation (PN) and Anammox (ANA). We specifically investigate the effects of operational conditions (SRT, HRT, dissolved oxygen set point and temperature) on carbon recovery potential and ability to meet N discharge criteria according to European legislation. The results suggest that BF-AD can be a promising technology combination for carbon recovery. However, PN-ANA is as yet not suitable for European conditions within the context of studied design at the current state of technology development.</p

Skyrmions in square-lattice antiferromagnets

The ground states of square-lattice two-dimensional antiferromagnets with anisotropy in an external magnetic field are determined using Monte Carlo simulations and compared to theoretical analysis. We find a phase in between the spin-flop and spiral phase that shows strong similarity to skyrmions in ferromagnetic thin films. We show that this phase arises as a result of the competition between Zeeman and Dzyaloshinskii-Moriya interaction energies of the magnetic system. Moreover, we find that isolated (anti-)skyrmions are stabilized in finite-sized systems, even at higher temperatures. The existence of thermodynamically stable skyrmions in square-lattice antiferromagnets provides an appealing alternative over skyrmions in ferromagnets as data carriers