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Visser, A. (author), Schaap, J.D. (author), Broers, H.P. (author), Bierkens, M.F.P. (author), TNO Bouw en Ondergrond (author)The production of N2 gas by denitrification may lead to the appearance of a gas phase below the water table prohibiting the conservative transport of tracer gases required for groundwater dating. We used a two-phase flow and transport model (STOMP) to study the reliability of 3H/3He, CFCs and SF6 as groundwater age tracers under agricultural...article 2009
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Visser, A. (author), Schaap, J.D. (author), Leijnse, T. (author), Broers, H.P. (author), Bierkens, M.F.P. (author), TNO Bouw en Ondergrond (author)Degassing of groundwater by excess denitrification of agricultural pollution complicates the interpretation of 3H/3He data and hinders the estimation of travel times in nitrate pollution studies. In this study we used a two-phase flow and transport model (STOMP) to evaluate the method presented by Visser (2007a) to interpret degassed 3H/ 3He...conference paper 2008
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Visser, A. (author), Broers, H.P. (author), Bierkens, M.F.P. (author), TNO Bouw en Ondergrond (author)The production of gases in groundwater under contaminated locations by geochemical and biological processes is not uncommon. Degassing of these gases from groundwater and repartitioning of noble gases between water and gas phase distorts groundwater dating by 3H/3He. We observed noble gas concentrations below atmospheric equilibrium in 20 out of...article 2007
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Griffioen, J. (author), Nederlands Instituut voor Toegepaste Geowetenschappen TNO (author)Nutrient-rich exfiltrating groundwater may impose a heavy phosphate load on surface water systems. However, iron oxides that bind PO4 precipitate fast upon oxygenation at neutral pH and PO4 may also become bound in Ca precipitates following upon pH increase, so load estimates based on conservative behaviour during exfiltration will be...article 2006
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Mertens, B.M. (author), van der Zwan, B. (author), de Jager, P.W.H. (author), Leenders, M. (author), Werij, H.G.C. (author), Benschop, J.P.H. (author), van Dijsseldonk, A.J.J. (author), Technisch Physische Dienst TNO - TH (author)Contamination of optics and mask is one of the possible show stoppers for Extreme Ultraviolet Lithography. One of the important sources of hydrocarbon contamination is the outgassing of photoresist coated wafers. Due to the vacuum conditions, these hydrocarbons can freely travel to coat the first optical component they encounter. This leads to...article 2000