963 research outputs found
Emissie meten makkelijker gezegd dan gedaan : Lysimeter moet waterstromen in chrysantenteelt in kaart brengen (interview met o.a. Wim Voogt)
No full textOp het bedrijf van Jos en Ron Ammerlaan zijn twee lysimeters ingegraven om de uitspoeling van water en nutriënten in kaart te brengen. De onderzoekers Wim Voogt en Marius Heinen begeleiden dit project. Het blijkt in de praktijk enorm moeilijk om een juiste meting uit te voeren, die ook nog eens praktisch is. Als het lukt, dan kunnen telers zowel hun emissie terug brengen als hun teeltresultaat verder optimaliseren
Integrated assessment of estrogens and xenoestrogens in the aquatic environment of the Netherlands: weight of evidence and ecological relevance
No full textToxic pressure of chemical stressors on pelagic microalgae in Dutch estuarine and coastal waters
Full text linkVethaak, A.D. [Promotor]Voogt, W.P. de [Promotor]Leonards, P.E.G. [Copromotor]Lamoree, M.H. [Copromotor
Occurrence of Estrogenic Hormones,Bisphenol-A and Phthalates in the Aquatic Environment of the Netherlands
No full text
Perfluorinated substances in human food and other sources of human exposure
No full textPerfluorinated compounds (PFCs) are ubiquitous environmental contaminants, which persist and may bioaccumulate through the food chain (Haukås et al. 2007; Martin et al. 2004b; Taniyasu et al. 2003). As a consequence, several PFCs have been detected in different biota worldwide. In recent years, an increasing number of papers report high levels of PFCs in blood, tissues, and breast milk from both occupationally and non-occupationally exposed human populations (Kannan et al. 2004; Kärrman et al. 2007; Olsen et al. 2007). The most important exposure pathways of perfluorinated compounds for humans are thought to be intake of drinking water and food and inhalation of dust (Björklund et al. 2009; Ericson et al. 2008a). Due to the widespread distribution, environmental degradation, and metabolism of the PFCs released into the environment, a very complex exposure situation exists (Fromme et al. 2007a). As a result, the relative contribution to human exposure from different routes or from a single source (e.g., diet) is not yet known. More specifically, it is currently unknown as to what extent exposure to drinking water, food, or dust contributes to the PFCs measured in human breast milk and blood. Moreover, data on levels of PFCs in the human diet are rather scarce (Kärrman et al. 2009; Tittlemier et al. 2006, 2007). Only PFC levels in fish appear to be well documented (Houde et al. 2006). Few studies, however, report the levels of PFCs in drinking water or human food such as vegetables, meat, and eggs (FSA 2006; US EPA 2001). Food processing such as cooking (boiling, baking, or grilling) could alter the concentration of PFCs in food and as a consequence affect the risk for humans
Determination of unsteady wing loading using tuft visualization
No full textUnsteady separated flow affects the aerodynamic performance of many large-scale objects, posing challenges for accurate assessment through low-fidelity simulations. Full-scale wind tunnel testing is often impractical due to the object’s physical scale. Small-scale wind tunnel tests can approximate the aerodynamic loading, with tufts providing qualitative validation of surface flow patterns. This investigation demonstrates that tufts can quantitatively estimate unsteady integral aerodynamic lift and pitching moment loading on a wing. We present computational and experimental data for a NACA0012 wing, capturing unsteady surface flow and force coefficients beyond stall. Computational data for varying angles of attack and Reynolds numbers contain the lift coefficient and surface flow. Experimental data, including lift and moment coefficients for a tuft-equipped NACA0012 wing, were obtained at multiple angles of attack and constant Reynolds number. Our results show that a data-driven surrogate model can predict lift and pitching moment fluctuations from visual tuft observations.</p
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