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Izquierdo-Lara, Ray W. (author), Heijnen, Leo (author), Oude Munnink, Bas B. (author), Schapendonk, Claudia M.E. (author), Elsinga, Goffe (author), Langeveld, J.G. (author), Post, Johan (author), Prasad, Divyae K. (author), Medema, G.J. (author)Monitoring of SARS-CoV-2 in wastewater (WW) is a promising tool for epidemiological surveillance, correlating not only viral RNA levels with the infection dynamics within the population, but also to viral diversity. However, the complex mixture of viral lineages in WW samples makes tracking of specific variants or lineages circulating in the...journal article 2023
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Langeveld, J.G. (author), Schilperoort, Remy (author), Heijnen, Leo (author), Elsinga, Goffe (author), Schapendonk, Claudia E.M. (author), Fanoy, Ewout (author), de Schepper, Evelien I.T. (author), Koopmans, Marion P.G. (author), de Graaf, Miranda (author), Medema, G.J. (author)Over the course of the Corona Virus Disease-19 (COVID-19) pandemic in 2020–2022, monitoring of the severe acute respiratory syndrome coronavirus 2 ribonucleic acid (SARS-CoV-2 RNA) in wastewater has rapidly evolved into a supplementary surveillance instrument for public health. Short term trends (2 weeks) are used as a basis for policy and...journal article 2023
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de Graaf, Miranda (author), Langeveld, J.G. (author), Post, Johan (author), Carrizosa, Christian (author), Franz, Eelco (author), Izquierdo-Lara, Ray W. (author), Elsinga, Goffe (author), Heijnen, Leo (author), Medema, G.J. (author)Despite high vaccination rates in the Netherlands, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to circulate. Longitudinal sewage surveillance was implemented along with the notification of cases as two parts of the surveillance pyramid to validate the use of sewage for surveillance, as an early warning tool, and to...journal article 2023
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Wang, N. (author), Verzijlbergh, R.A. (author), Heijnen, P.W. (author), Herder, P.M. (author)Energy system optimization models are widely used to aid long-term investment decision-making for energy systems. From a socio-technical system viewpoint, existing models focus on the cost modeling of the technical subsystem, while the indirect costs of the social subsystem are not often modeled. This paper incorporates indirect costs into such...journal article 2023
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Wang, N. (author), LIU, Z. (author), Heijnen, P.W. (author), Warnier, Martijn (author)As the use of distributed energy resources increases, peer-to-peer (P2P) energy trading is becoming a promising way to harmonize the decarbonization and decentralization transformations in the energy sector. P2P markets give households the autonomy to make individual decisions and thus they may cooperate with each other to obtain economic...journal article 2022
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Frey, Daniel D. (author), Lin, Yiben (author), Heijnen, P.W. (author)This paper develops theoretical foundations for extending Gauss-Hermite quadrature to robust design with computer experiments. When the proposed method is applied with m noise variables, the method requires 4m + 1 function evaluations. For situations in which the polynomial response is separable, this paper proves that the method gives exact...journal article 2021
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Wang, N. (author), Heijnen, P.W. (author), Imhof, Pieter (author)Renewable energy investment is a complex process where multiple actors are often involved with their own, sometimes conflicting, interests. Here we propose a multi-actor multi-objective regional energy system planning approach to help actors gain mutual understanding regarding each other’s optimal investment wishes, in order to advance the...journal article 2020
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Wang, N. (author), Verzijlbergh, R.A. (author), Heijnen, P.W. (author), Herder, P.M. (author)Variable Renewable Energy Sources (VRES) are characterized by intensive land-use and variable production. In existing optimization models that minimize the total cost of the energy system, location-specific VRES production profiles are often used to estimate VRES potential, but land-use and land cover aspects have been largely ignored. In this...journal article 2020
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Hornstra, Luc M. (author), Rodrigues da Silva, T. (author), Blankert, Bastiaan (author), Heijnen, Leo (author), Beerendonk, Erwin (author), Cornelissen, Emile R. (author), Medema, G.J. (author)High pressure membranes are increasingly used for the treatment of contaminated water for various purposes including irrigation and drinking water. The lack of a fast and easy to implement membrane integrity test method with a log removal value (LRV) >3 hampers the implementation of these membranes. Current on-line methods include...journal article 2019
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Aggregator-mediated demand response: Minimizing imbalances caused by uncertainty of solar generationOkur, Ö. (author), Voulis, N. (author), Heijnen, P.W. (author), Lukszo, Z. (author)The high level of uncertainty of renewable energy sources generation creates differences between electricity supply and demand, endangering the reliable operation of the power system. Demand response has gained significant attention as a means to cope with uncertainty of renewable energy sources. Demand response of residential and service...journal article 2019
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Heijnen, P.W. (author), Chappin, E.J.L. (author), Herder, P.M. (author)Systems engineers are equipped to design complex networked systems such as infrastructures. A key goal is cost minimization over a vast solution space. However, finding a minimum-cost system while comprehensively satisfying different stakeholders is challenging and lacks proper methodological support. Stakeholders often employ their own...journal article 2019
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Wang, G. (author), Zhao, Junfei (author), Haringa, C. (author), Tang, W. (author), Xia, Jianye (author), Chu, Ju (author), Zhuang, Yingping (author), Zhang, Siliang (author), Deshmukh, A.T. (author), van Gulik, W.M. (author), Heijnen, J.J. (author), Noorman, H.J. (author)In a 54 m<sup>3</sup> large-scale penicillin fermentor, the cells experience substrate gradient cycles at the timescales of global mixing time about 20–40 s. Here, we used an intermittent feeding regime (IFR) and a two-compartment reactor (TCR) to mimic these substrate gradients at laboratory-scale continuous cultures. The IFR was applied to...journal article 2018
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Haringa, C. (author), Tang, W. (author), Wang, G. (author), Deshmukh, A.T. (author), van Winden, Wouter A. (author), Chu, Ju (author), van Gulik, W.M. (author), Heijnen, J.J. (author), Mudde, R.F. (author), Noorman, H.J. (author)We assess the effect of substrate heterogeneity on the metabolic response of P. chrysogenum in industrial bioreactors via the coupling of a 9-pool metabolic model with Euler-Lagrange CFD simulations. In this work, we outline how this coupled hydrodynamic-metabolic modeling can be utilized in 5 steps. (1) A model response study with a fixed...journal article 2018
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da Fonte Lameiras, F. (author), Ras, C. (author), ten Pierick, A. (author), Heijnen, J.J. (author), van Gulik, W.M. (author)In its natural environment, the filamentous fungus Aspergillus niger grows on decaying fruits and plant material, thereby enzymatically degrading the lignocellulosic constituents (lignin, cellulose, hemicellulose, and pectin) into a mixture of mono- and oligosaccharides. To investigate the kinetics and stoichiometry of growth of this fungus...journal article 2017
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Noorman, H.J. (author), Heijnen, J.J. (author)Building on the recent revolution in molecular biology, enabling a wealth of bio-product innovations made from renewable feedstocks, the biotechnology field is in a transition phase to bring the products to the market. This requires a shift from natural sciences to engineering sciences with first conception of new, efficient large-scale...journal article 2017
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Cueto Rojas, H.F. (author), Maleki Seifar, R. (author), ten Pierick, A. (author), Heijnen, J.J. (author), Wahl, S.A. (author)Ammonium (NH4+) is the most common N-source for yeast fermentations, and N-limitation is frequently applied to reduce growth and increase product yields. While there is significant molecular knowledge on NH4 + transport and assimilation, there have been few attempts to measure the in vivo concentration of this metabolite. In this article, we...journal article 2016
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Suarez Mendez, C.A. (author), Hanemaaijer, M. (author), Ten Pierick, A. (author), Wolters, J.C. (author), Heijnen, J.J. (author), Wahl, S.A. (author)13C labeling experiments in aerobic glucose limited cultures of Saccharomyces cerevisiae at four different growth rates (0.054; 0.101, 0.207, 0.307 h?1) are used for calculating fluxes that include intracellular cycles (e.g., storage carbohydrate cycles, exchange fluxes with amino acids), which are rearranged depending on the growth rate. At low...journal article 2016
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Cueto Rojas, H.F. (author), Maleki Seifar, R. (author), ten Pierick, A. (author), van Helmond, W. (author), Pieterse, M.M. (author), Heijnen, J.J. (author), Wahl, S.A. (author)Ammonium is the most common N source for yeast fermentations. Although its transport and assimilation mechanisms are well documented, there have been only a few attempts to measure the in vivo intracellular concentration of ammonium and assess its impact on gene expression. Using an isotope dilution mass spectrometry (IDMS)-based method, we...journal article 2016
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Haringa, C. (author), Tang, Wenjun (author), Deshmukh, Amit T. (author), Xia, Jianye (author), Reuss, Matthias (author), Heijnen, J.J. (author), Noorman, H.J. (author), Mudde, R.F. (author)The trajectories, referred to as lifelines, of individual microorganisms in an industrial scale fermentor under substrate limiting conditions were studied using an Euler-Lagrange computational fluid dynamics approach. The metabolic response to substrate concentration variations along these lifelines provides deep insight in the dynamic...journal article 2016
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Melese, Y.G. (author), Heijnen, P.W. (author), Stikkelman, R.M. (author), Herder, P.M. (author)Energy and industrial networks such as pipeline-based carbon capture and storage infrastructures and (bio)gas infrastructures are designed and developed in the presence of major uncertainties. Conventional design methods are based on deterministic forecasts of most likely scenarios and produce networks that are optimal under those scenarios....journal article 2016