Britta Petersen

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Thesis submitted in fulfillment of the requirements for the degree of Doctor (Ph.D) in Applied Biological Sciences Proefschrift voorgedragen tot het bekomen van de graad van Doctor in de Toegepaste Biologische Wetenschappen op gezag vanSummary The activated sludge process is one of the most widespread biological wastewater purification technologies.(More)
An earlier study on theoretical identifiability of parameters for a two-step nitrification model showed that a unique estimation of the yield YA1 is possible with combined respirometric-titrimetric data, contrary to the case where only one type of measurement is available. Here, the practical identifiability of model parameters was investigated via(More)
A short review of different respirometric methods is presented, and advantages and disadvantages of different principles are discussed. In this study a combined respirometric-titrimetric set-up was applied to monitor the degradation processes during batch experiments with activated sludge. The respirometer consists of an open aerated vessel and a closed(More)
Experimental results obtained in a batch reactor are presented showing different fast dynamic phenomena. All measured OUR-profiles show a 'start-up' phase upon substrate addition. Neither the response time of the DO-electrode, the mixing characteristics in the reactor or the extracellular transport limitations could explain this behaviour. It is(More)
A methodology for calibration of the activated sludge plant models is proposed on the basis of consolidated engineering experience and a scientific approach. According to the method, the definition of the target(s) plays a crucial role in the selection of the steps incorporated in this so-called 'Biomath-Calibration' protocol. For the activated sludge(More)
The structural and practical identifiability of a model for description of respirometric-titrimetric data derived from aerobic batch substrate degradation experiments of a C(x)H(y)O(z) carbon source with activated sludge was evaluated. The model processes needed to describe titrimetric data included substrate uptake, CO(2) production, and NH(3) uptake for(More)
The first step in the estimation of parameters of models applied for data interpretation should always be an investigation of the identifiability of the model parameters. In this study the structural identifiability of the model parameters of Monod-based activated sludge models (ASM) was studied. In an illustrative example it was assumed that respirometric(More)
Many scientific disciplines ranging from physics, chemistry and biology to material sciences, geophysics and medical diagnostics need a powerful X-ray source with pulse lengths in the femtosecond range 1-4. This would allow, for example, time-resolved observation of chemical reactions with atomic resolution. Such radiation of extreme intensity, and tunable(More)
AIMS Development of a predictive model for the determination of the shelf life of modified atmosphere-packed (MAP) cooked sliced ham in each step of the cold chain. METHODS AND RESULTS The growth of lactic acid bacteria (LAB), as well as the development of the total viable count and changes of sensory and pH value parameters in MAP cooked sliced ham,(More)
The Tera-eV Energy Superconducting Linear Accelerator (TESLA), a 32 km long superconducting linear electron/positron collider of 500 GeV (upgradeable to 800 GeV) centre of mass energy, presently in the planning phase at DESY, will consist of about 21000 superconducting RF 9-cell cavities of pure Niobium. Each cavity of about 1 m length has to be cooled in a(More)