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Semiconductor nanocrystals (NCs), which can have a variety of sizes, shapes and chemical compositions, will be a large and important family of future advanced materials.This thesis focuses on colloidal semiconductor NC solids, also called quantum-dot (QD) solids, which are promising materials for many applications, such as photo-detectors, field-effect transistors, solar cells, light-emitting diodes, and lasers. The thesis presents studies on the charge carrier properties of PbSe QD solids, going through the charge carrier photogeneration, thermalization, diffusion and decay, which together are the ``life and fate'' of the charge carriers. Diverse tools have been utilized to reveal the whole picture of the ``life and fate''. The most important ones are: femtosecond transient absorption spectroscopy (TA) (Chapter 2, 3, 4), picosecond Terahertz spectroscopy (THz) (Chapter 2), the nanosecond time-resolved microwave conductivity technique (TRMC) (Chapter 2-5), and Monte Carlo simulations (Chapter 4).

This contribution focuses on geodetic sensor systems and sensor networks for positioning and applications. The key problems in this area will be addressed together with an overview of applications. Global Navigation Satellite Systems (GNSS) and other geodetic techniques play a central role in many applications like engineering, mapping and remote sensing. These techniques include precise positioning, but also research into non-positioning applications like atmospheric sounding using continuously operating GNSS networks. An important research area is multi-sensor system theory and applications to airborne and land-based platforms, indoor and pedestrian navigation, as well as environmentalmonitoring. The primary sensors of interest are GNSS and inertial navigation systems. Furthermore, Interferometric Synthetic Aperture Radar (InSAR) is recognized as one of the most important state-of-the-art geodetic technologies used for generation of Digital Elevation Models and accurately measuring ground deformations

GNSS, InSAR and LIDAR are identified as important techniques when it comes to monitoring and remote sensing of our planet Earth and its atmosphere. In fact, these techniques can be considered as key elements of the Global Geodetic Observing System. Examples of applications are: environmental monitoring; volcano monitoring, land slides, tectonic motion, deforming structures, atmosphere modeling, and ocean remote sensing. Hence, it concerns applications at local and regional scales, as well as at global scales. The main issues can be summarized as: need for a better understanding of processes, leading to better models; need for observational material; and adequate modeling techniques