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Rietveld, M.W.J. (author), Clemens, F.H.L.R. (author), Langeveld, J.G. (author)Runoff entering urban drainage systems contains suspended solids, which carry pollutants and may cause blockages in downstream parts of the system (for example infiltration facilities). Suspended solids inflow should, therefore, preferably be controlled by solids removal at gully pots. This paper presents the results of lab experiments on the...journal article 2020
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Tscheikner-Gratl, F. (author), Bellos, Vasilis (author), Schellart, Alma (author), Moreno Rodenas, A. (author), Muthusamy, Manoranjan (author), Langeveld, J.G. (author), Clemens, F.H.L.R. (author), Shucksmith, James (author), Heuvelink, Gerard B.M. (author)This paper aims to stimulate discussion based on the experiences derived from the QUICS project (Quantifying Uncertainty in Integrated Catchment Studies). First it briefly discusses the current state of knowledge on uncertainties in sub-models of integrated catchment models and the existing frameworks for analysing uncertainty. Furthermore, it...review 2019
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Rietveld, M.W.J. (author), Clemens, F.H.L.R. (author), Langeveld, J.G. (author)Sewer and urban drainage systems deal with the runoff of areas that lack infiltration capacity. During wet weather, solids that are present on the street are (re)mobilised and transported to the drainage system by the runoff. These solids and their associated pollutants can have detrimental effects on receiving water quality. This paper presents...conference paper 2019
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Moreno Rodenas, A. (author), Tscheikner-Gratl, F. (author), Langeveld, J.G. (author), Clemens, F.H.L.R. (author)Receiving water quality simulation in highly urbanised areas requires the integration of several processes occurring at different space-time scales. These integrated catchment models deliver results with a significant uncertainty level associated. Still, uncertainty analysis is seldom applied in practice and the relative contribution of the...journal article 2019
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Meijer, D.W.J. (author), Scholten, L. (author), Clemens, F.H.L.R. (author), Knobbe, Arno (author)Sewer pipes are commonly inspected in situ with CCTV equipment. The CCTV footage is then reviewed by human operators in order to classify defects in the pipes and make a recommendation on possible interventions. This process is both labor-intensive and error-prone. Other researchers have suggested machine learning techniques to (partially)...journal article 2019
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Moreno Rodenas, A. (author), Langeveld, J.G. (author), Clemens, F.H.L.R. (author)Water quality environmental assessment often requires the joint simulation of several subsystems (e.g. wastewater treatment processes, urban drainage and receiving water bodies). The complexity of these integrated catchment models grows fast, leading to potentially over-parameterised and computationally expensive models. The receiving water body...journal article 2019
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Mehta, D. (author), Thota Radhakrishnan, A.K. (author), van Lier, J.B. (author), Clemens, F.H.L.R. (author)This article follows from a previous study by the authors on the computational fluid dynamics-based analysis of Herschel-Bulkley fluids in a pipe-bounded turbulent flow. The study aims to propose a numerical method that could support engineering processes involving the design and implementation of a waste water transport system, for...journal article 2019
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Makris, K. (author), Langeveld, J.G. (author), Clemens, F.H.L.R. (author)Polyvinyl chloride (PVC) has become one of the dominant construction materials for sewer systems over the past decades, as a result of its reputed merits. However, since PVC sewer pipes have operated for decades in a hostile environment, concern over their longevity has been lately raised by sewer managers in the Netherlands. Towards that...journal article 2019
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Tscheikner-Gratl, Franz (author), Caradot, Nicolas (author), Cherqui, Frederic (author), Leitão, Joao P. (author), Langeveld, J.G. (author), Scholten, L. (author), Lepot, M.J. (author), Stegeman, B. (author), Clemens, F.H.L.R. (author)Sewer asset management gained momentum and importance in recent years due to economic considerations, since infrastructure maintenance and rehabilitation directly represent major investments. Because physical urban water infrastructure has life expectancies of up to 100 years or more, contemporary urban drainage systems are strongly influenced...review 2019
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Stegeman, B. (author), Langeveld, J.G. (author), Bogaard, T.A. (author), Clemens, F.H.L.R. (author)Due to the ageing of our underground wastewater infrastructure, leakage of sewers and pressure mains and subsequent infiltration or exfiltration are becoming an increasingly important issue. Herein, we present a novel method to detect and potentially quantify exfiltration from sewer systems under variable flow conditions; the DEST method. The...conference paper 2019
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Mehta, D. (author), Thota Radhakrishnan, A.K. (author), van Lier, J.B. (author), Clemens, F.H.L.R. (author)The concentration of domestic slurry has two advantages, it promotes resource recovery (nutrients and biomass) and saves water. But the design of a relevant sewerage requires a clear understanding of the frictional losses incurred during the transport of the slurry. This abstracts describes numerical & CFD-based methods to estimate losses...conference paper 2019
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Moreno Rodenas, A. (author), Bellos, V. (author), Langeveld, J.G. (author), Clemens, F.H.L.R. (author)This work presents a method to emulate the flow dynamics of physically based hydrodynamic simulators under variations of time-dependent rainfall and parametric scenarios. Although surrogate modelling is often employed to deal with the computational burden of this type of simulators, common techniques used for model emulation as polynomial...journal article 2018
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Thota Radhakrishnan, A.K. (author), van Lier, J.B. (author), Clemens, F.H.L.R. (author)Information on the rheology of domestic slurries is essential in designing pipeline transportation in novel sanitation systems. As concentrated slurries in their original collected state have wide particle size distribution, with particles up to 2 mm, a wide gap rheometer is used to acquire the rheograms. Rheograms obtained from a wide gap...journal article 2018
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Thota Radhakrishnan, A.K. (author), van Lier, J.B. (author), Clemens, F.H.L.R. (author)The much over-looked element in new sanitation, the transport systems which bridge the source and treatment facilities, is the focus of this study. The knowledge of rheological properties of concentrated domestic slurry is essential for the design of the waste collection and transport systems. To investigate these properties, samples were...journal article 2018
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Nieuwenhuis, E.M. (author), Post, J.A.B. (author), Duinmeijer, S.P.A. (author), Langeveld, J.G. (author), Clemens, F.H.L.R. (author)The accumulation of FOG (Fat, Oil and Grease) deposits in sewer pumping stations results in an increase in maintenance costs, malfunctioning of pumps and, a potential increase of wastewater spills in receiving open water bodies. It is thought that a variety of parameters (e.g. geometry of the pump sump, pump operation, socioeconomic...journal article 2018
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van Bijnen, J.A.C. (author), Korving, J.L. (author), Langeveld, J.G. (author), Clemens, F.H.L.R. (author)Due to a variety of contaminants in floodwater, exposure to urban pluvial flooding may pose a health risk to humans. In-sewer defects may cause increased pluvial flooding, possibly increasing health risks. This paper addresses the impact of in-sewer defects on urban pluvial flooding and, subsequently, on infection probabilities for humans. As...journal article 2018
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Meijer, D.H. (author), van Bijnen, J.A.C. (author), Langeveld, J.G. (author), Korving, J.L. (author), Post, J.A.B. (author), Clemens, F.H.L.R. (author)Underground water infrastructure is essential for life in cities. The aging of these infrastructures requires maintenance strategies to maintain a minimum service level. Not all elements are equally important for the functioning of the infrastructure as a whole. Identifying the most critical elements in a network is crucial for formulating...journal article 2018
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Mehta, D. (author), Thota Radhakrishnan, A.K. (author), van Lier, J.B. (author), Clemens, F.H.L.R. (author)The concentration (using a lesser amount of water) of domestic slurry promotes resource recovery (nutrients and biomass) while saving water. This article is aimed at developing numerical methods to support engineering processes such as the design and implementation of sewerage for concentrated domestic slurry. The current industrial standard...journal article 2018
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Hofer, Christina (author), Bliznuk, Vitaliy (author), Verdiere, An (author), Petrov, R.H. (author), Winkelhofer, Florian (author), Clemens, Helmut (author), Primig, Sophie (author)The multiphase microstructure of carbide-free bainitic steels comprises bainitic ferrite laths, retained austenite with different morphologies, a minor fraction of carbides and so-called martensite-austenite areas, which partially transform during the last cooling step. While the other constituent received much attention, little is known...journal article 2018
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Mahmoodian, M. (author), Carbajal, Juan Pablo (author), Bellos, Vasilis (author), Leopold, Ulrich (author), Schutz, Georges (author), Clemens, F.H.L.R. (author)Urban drainage modelling typically requires development of highly detailed simulators due to the nature of various underlying surface and drainage processes, which makes them computationally too expensive. Application of such simulators is still challenging in activities such as real-time control (RTC), uncertainty quantification analysis or...journal article 2018