As part of the SAFElevee project Delft University of Technology collabored with Flanders Hydraulics Research, and Infram B.V. in the preperation and execution of a full scale embankment breach experiment in November 2015. This breach experiment was performed on an 3.5m high embankment with a sand core and clay outer layer situated along the tidal river Scheldt in Belgium near Schellebelle. During the experiment a wave overtopping simulator and overflow simulator were used to initiate a breach. Both simulators were placed near the top of the waterside slope. The use of the simulators facilitated comparison between the effects of continueous overflow and the effects of intermittent wave overtopping. This paper presents the data collected during the experiment, describe the development of hypotheses on the failure processes using the latest insights, and comment on the failure initiation process of a grass covered flood embankment with a clay outer layer and a sandy core.@en

Optical analysis of hydrogenated amorphous silicon (a-Si:H) solar cells with a periodic texture applied to the interfaces was carried out by two-dimensional optical simulator. The optical simulator solves the electromagnetic wave equations by means of finite element method using triangular elements for the discretization of space. The periodic texture with rectangular-like shape acts as a diffraction grating which scatters light into selective angles and thus gives a potential for significant prolongation of optical paths in thin absorber layers of the cells. Optimization of the geometrical parameters (period, height and duty-cycle) of the periodic texture was carried out in order to obtain the highest photocurrent from a-Si:H solar cells. The a-Si:H solar cell with the optimal periodic texture parameters (period of 300¿nm, height of 300¿nm and duty cycle of 50%) and the absorber layer thickness of 300¿nm generates up to 35% more photocurrent in comparison to the cell with flat interfaces. The optical analysis demonstrates that the optimal periodic texture in the a-Si:H solar cell results in the best trade-off between the antireflection effect at front interfaces, light scattering efficiency and the absorption losses at realistic metal back contact.@en

In this paper, a hybrid system consisting of metal nano-particles dispersed on the surface of a dielectric layer is presented: a remote Expanding Thermal Plasma CVD system is used for the deposition of the inorganic (i.e. SiO2) layers from hexamethyldisiloxane/oxygen mixtures in combination with an rf magnetron sputtering tool for the deposition of metallic (i.e. gold) nanoparticles on top of the SiO2 layers. The optical properties of the Au/SiO2 layers have been investigated by means of UV-VIS-NIR variable angle spectroscopic ellipsometry. Rutherford backscattering and transmission electron microscopy were used to determine the film density, the nanoparticle size and its distribution, respectively. The uniform distribution of gold nanoparticles on the surface of the SiO2 layers allows obtaining red- to blue- colored coatings as a consequence of the shift of the surface plasmon resonance band to higher wavelengths, caused by an increase in size of nanoparticles and metal surface coverage.@en