New Guidelines for the Quality Control of Risk Analyses of Critical Hydraulic Structures

The efficacy of risk models and risk analyses critically hinges on sufficient model evaluation. Nevertheless, the usefulness for the intended purpose is rarely systematically assessed. Poor or even lacking model evaluation of the applied risk models and analyses also troubles the asset management of storm surge barriers in the Netherlands. In...

Assessing the transition effects in a drinking water distribution system caused by changing supply water quality: an indirect approach by characterizing suspended solids

Worldwide, it is common that the drinking water distribution systems (DWDSs) may be subjected to changes of supply water quality due to the needs of upgrading the treatment processes or switching the source water. However, the potential impacts of quality changed supply water on the stabilized ecological niches within DWDSs and the associated...

Feasibility of surface sampling in automated inspection of concrete aggregates during bulk transport on a conveyor

Automated optic inspection of concrete aggregates for pollutants (e.g. wood, plastics, gypsum and brick) is required to establish the suitability for reuse in new concrete products. Inspection is more efficient when directly sampling the materials on the conveyor belt instead of feeding them in a sampled stream to the sensor system. However,...

Feasibility of surface sampling in automated inspection of concrete aggregates during bulk transport on a conveyor

Automated optic inspection of concrete aggregates for pollutants (e.g. wood, plastics, gypsum and brick) is required to establish the suitability for reuse in new concrete products. Inspection is more efficient when directly sampling the materials on the conveyor belt instead of feeding them in a sampled stream to the sensor system. However,...

On the homogeneity of a thick layer of mixed granules in optical quality inspection

Optical inspection of a thick layer of granules for foreign particles does not directly reveal their true number and the more so if the layer is not homogenous. This raises questions such as “how do I know if the layer is homogenous?” and “what is the relation between the observable particles and the true number?” In this work a theory is...

Ultrasound imaging for quantitative measurement of immersed plastic waste particles

Ultrasound imaging techniques are proposed for measuring the shape and thickness of immersed waste particles (10-20 mm size) using a linear sensor array from a fixed position. For these purposes both the front and back surface of a particle needs to be reconstructed. Raw ultrasound pulse-echo and plane wave datasets and different imaging...

Higher energy efficiency and better water quality by using model predictive flow control at water supply systems

Half of all water supply systems in the Netherlands are controlled by model predictive flow control; the other half are controlled by conventional level based control. The differences between conventional level based control and model predictive control were investigated in experiments at five full scale water supply systems in the first half of...

Propagation of a cadmium spill through an impounded river system

In this paper, the influence of impoundments (sluices, weirs, etc.) and stream components (tributaries, river branches, associated canals) on the metal content in water and suspended particulate matter (SPM) in the Dutch part of the River Meuse is assessed using the decrease in the cadmium content of the particulate and dissolved phase during...