Electron microscopes take advantage of a beam of electrons to illuminate a specimen and extract the needed information from the interaction of particles with matter in order to produce a high resolution image. The main research question of the present study arose from the fact that this resolution is degraded when a given specimen contains insulating materials. In the electron microscopy of insulators the effect behind the degradation of an image resolution is known as the charging effect. The charging effect needs to be studied and understood, in particular, since biological specimens are either insulators or contain insulating parts.@en

This paper presents a modified self-consistent drift-diffusion-reaction model suitable for the analysis of electron-beam irradiated insulators at both short and long time scales. A novel boundary condition is employed that takes into account the reverse electron current and a fully dynamic trap-assisted generation-recombination mechanism is implemented. Sensitivity of the model with respect to material parameters is investigated and a calibration procedure is developed that reproduces experimental yield-energy curves for uncharged insulators. Long-time charging and yield variations are analyzed for stationary defocused and focused beams as well as moving beams dynamically scanning composite insulators.

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Dike reinforcement decision making under uncertainty is a challenging task. This paper examines whether increasing the managerial flexibility of a reinforcement strategy can improve the lifecycle cost-effectiveness for the Dutch flood defences. Two flexible strategies are developed and compared to an inflexible baseline strategy. The strategies are examined in eight case studies, two sea level rise scenarios, and four discount rates. It is shown that increasing the flexibility of reinforcement can improve the cost-effectiveness for monofunctional dikes. The relative cost-effectiveness of flexible strategies decreases as the dike becomes multifunctional. The results prove to be sensitive to the choice of the scenario and discount rate. It is concluded that reinforcement decision making should address uncertainty explicitly and account for smaller scale developments around the dike. It is suggested that current engineering practice can be improved if the possibility of a variable design lifetime is also addressed in reinforcement decision making.@en