TU Delft Repository

The growing availability of SAR data offers a real-time deformation monitoring opportunity, but data utilization can be inefficient. Our study introduces a mathematical framework using recursive least-squares and the wrapped phase, allowing efficient updates when new data arrives. This method also incorporates prior knowledge about signal smoothness for non-linear displacement estimation. Compared to the batch solution, our recursive approach achieves parameter estimation without storing past measurements while respecting signal smoothness constraints.

In this study, we investigated the influence of structural parameters, including active region dimensions, electric field intensity, In-composition, impurity position, and potential profiles, on the energy levels, sub-gap transitions, and photovoltaic characteristics of a p-GaN/i-(In, Ga)N/GaN-n (p-QW-n) structure. The finite element method (FEM) has been used to solve numerically the Schrödinger equation. We found that particle and sub-gap energy levels are susceptible to well width, electric field, and impurity position. Particle energy decreases with increasing well size and electric field intensity, while impurity position affects energy based on proximity to the well center. Potential profile shapes, such as rectangular (RQW) and parabolic (PQW), also play a significant role, with PQW profiles providing stronger particle confinement. IB width increases with electric field intensity and saturates at higher In-content. Voc increases with field strength but decreases with In-content, and the parabolic profile yields higher efficiency than the rectangular one. Photovoltaic efficiency is improved with an appropriately oriented electric field and decreases with higher In-content and field intensity. These findings highlight the critical role of structural parameters in optimizing QW-IBSC performance.

In this thesis, the identification and generation of meteotsunamis on the Southern North Sea are investigated. Although meteotsunamis are well known in other areas, hardly any research has been done on them near the Dutch Coast. Here, nine years of sea level elevation data are evaluated using the classic approach and a subsequent wavelet analysis to identify a list of potential meteotsunamis. Six of those events have been selected, for which the atmospheric conditions were simulated by WRF. To definitively classify them as meteotsunamis, a pressure jump and atmospheric front responsible for the generation are identified. The six events are characterized by computation of their angle of incidence, wave period, and wave height, and are checked for the probability of Proudman resonance. The six selected events were all linked to a pressure jump and an atmospheric front, and thus classified as meteotsunamis. Two events propagated from the North-West and the other four from the South through the English Channel. The wave periods varied between 10 and 25 minutes, and the wave heights varied around 0.20 meters, with a maximum wave height of 0.63 meters. Three events were linked to a front propagating overseas, all of which had a high probability that Proudman resonance contributed to their amplification. These results form a foundation for future research on meteotsunamis on the Southern North Sea.

This thesis shows the development of a singulation process for steel scrap particles. This singulation process is part of a sorting line that can sort scrap into different alloy types. This is an essential step in making steel a fully circular product. The new designs are based on an already existing chute used for aluminium singulation. In the report, the scrap properties and their behaviour on the aluminium chute are analysed. These insights are used to create three new designs for a chute that can be used for steel singulation. To evaluate these designs, a Discrete Element Method (DEM) model was used.