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As track behavior varies in a wide range of service lives and maintenance demands must be specified. The Standard Element Approach provides a specification based on the most important boundary conditions influencing track behavior such as transport load, alignment, superstructure components as well as substructure qualities, and last but not least the functionality of the dewatering system. These parameters show several possible values. The mix of all of these parameter values describes tracks in the entire network. This clustering helps for decision making for strategic asset management: superstructure component use for different parameter sets, calculating average maintenance and renewal demands and thus the respective budgets for a sustainable track strategy avoiding or reducing backlogs. The Standard Element Approach works for all railway infrastructure assets, this chapter focuses on track in detail.

We report on nanoscopic exploration of the luminescence from individual InP quantum dots (QDs) by means of highly spatially resolved cathodoluminescence (CL) spectroscopy directly performed in a scanning transmission electron microscope (STEM). A 7-fold layer stack with high-density InP quantum dots is embedded as an active medium membrane in an external-cavity surface-emitting laser. We characterize the vertical transfer of carriers within the periodic separate confinement heterostructure and determine the capture efficiency of carriers from the cladding layer into the quantum dot layers. Benefiting from the nanoscale resolution of our STEM-CL, we perform single-dot spectroscopy on single isolated QDs in the STEM lamella resolving the details of the excitonic structure of individual quantum dots. Executing highly spatially resolved spectrum line scans within the QD layers, we directly visualize the lateral transport