Diese Dissertation beschreibt ein System fur die Analyse haptischer Eigenschaften von Benutzerschnittstellen. Nach einer Einfuhrung in die Problemstellung und der Vorstellung eines Analyseframeworks wird die Implementierung eines beispielhaften Analysesystems fur Schalter und die Implementierung eines psychophysikalischen Modells vorgenommen.

The hydraulics of water and wastewater treatment reactors has a major impact on their performance and control. The residence time distribution as a measure for the hydraulics represents macroscopic mixing in an integrated way with no spatial information. However, with regard to optimal sensor location for process control and for process optimisation measures, spatial information about macro-mixing is helpful. Spatially distributed measurements of reactive tracers can provide this information. In this paper we generally discuss how reactive tracers can be used to detect and characterize distinct large scale flow structures. It is shown that tracer substances are particularly suited if their reaction time scale is similar to the time scale of the large scale flow structure. For nitrifying activated sludge systems, ammonium is identified to be a suitable tracer. In a comprehensive experimental study at a real aeration tank, two distinct large scale flow features were identified by distributed ammonium measurements. Flow velocity measurements using acoustic Doppler velocimetry clearly supported the nature of these flow field anomalies. Ion-selective electrodes are a well suited device for ammonium measurements providing the temporal resolution that is needed for such an analysis.

Due to the high energy input of aeration, the spatial distribution of air diffusers largely determines the flow field in aeration tanks. This has consequences on the efficiency of the aeration system, the performance of the aeration tank and on tank operation and control. This paper deals with these effects applying both Computational Fluid Dynamics (CFD) enhanced with a biokinetic model and full scale validation using velocity and reactive tracer measurements with high temporal and spatial resolution. It is shown that small changes in the diffuser arrangement drastically change the overall flow field. Using different aeration patterns in the same tank may lead to large scale instabilities in the flow field that lower plant performance and produce strong variations in concentration signals impeding their use for plant control. CFD is a valuable tool to analyze the interaction of flow field and aeration and their effects on plant performance and operation. But, in complex flow situations experimental validation is needed and strongly suggested.

Direct measurements of sewer leakage with continuous dosing of tracers are often considered too imprecise for practical applications. However, no mathematical framework for data analysis is reported in literature. In this paper, we present an improved experimental design and data analysis procedure together with a comprehensive framework for uncertainty assessment. Test runs in a 700 m-long watertight sewer showed no significant bias and a very high precision of the methodology. The standard error in the results was assessed to 2.6% of the labeled flow with a simplified model. It could be reduced to 1.2% when a dynamic data analysis procedure was applied. The major error contribution was caused by transient transport phenomena, which suggests that careful choosing of the experimental time is more important than the choice of a very specific tracer substance. Although the method is not intended to replace traditional CCTV inspections, it can provide complementary information for rational rehabilitation planning.

A direct approach to quantify exfiltration from sewers is the QUEST-C tracer method. In this study, the authors present a novel approach for the dynamic analysis of a tracer experiment, considering information on varying sewer flow. An assessment of uncertainty is developed that accounts for systematic and random errors in the measurements and the sampling scheme. It is shown that the precision of the exfiltration measurement with tracers can be significantly improved by the dynamic analysis.

In this paper the authors present a method to quantify the exfiltration from sewers with artificial tracers. In an application study Lithium and Bromide were used as ionic tracers. The results from an error analysis indicate that the main problems with the application of the method originate from the time-varying sewer flow. Accurate information on exfiltration could be used in innovative sewer operation and maintenance strategies.