Utslipp til sjø – kan enkle modeller gi tilstrekkelig grunnlag for vurdering av spredning, fortynning og surhetsgrad?

Det forelå i 2016 ca. 2500 utslippstillatelser for utslipp til kystvann i Norge. Til tross for mange bestrebelser på å redusere utslippene må en forvente at en også i fremtiden må leve med betydelige utslipp til sjø. For at dette skal være akseptabelt må det bestrebes å redusere innholdet av forurensende stoffer i utslippsvannet og benytte utslippsarrangement som gir minst mulig skadelige effekter. For å få til det er det nødvendig å få kartlagt i hvilke dyp et utslipp vil innlagres og den videre fortynningen. Modeller er viktige verktøy for optimalisering av utslippsarrangementet for å minimalisere risikoen for skadelige effekter. 3D-modeller er kompliserte og mer tidkrevende å bruke enn 2D modeller og ikke alltid hensiktsmessige når det er behov for enklere vurderinger. Vi vil her gi eksempler på hvordan enkle 2D modeller og sporstoff-forsøket med et fargestoff har vært brukt som grunnlag for å bestemme spredning og fortynning av et utslipp. Vi vil også vise hvordan utslipp av syre og base kan påvirke pH i en resipient.publishedVersio

The ecotoxicology of marine tributyltin (TBT) hotspots: A review

Tributyltin (TBT) was widely used as a highly efficient biocide in antifouling paints for ship and boat hulls. Eventually, TBT containing paints became globally banned when TBT was found to cause widespread contamination and non-target adverse effects in sensitive species, with induced pseudohermaphroditism in female neogastropods (imposex) being the best-known example. In this review, we address the history and the status of knowledge regarding TBT pollution and marine TBT hotspots, with a special emphasis on the Norwegian coastline. The review also presents a brief update on knowledge of TBT toxicity in various marine species and humans, highlighting the current understanding of toxicity mechanisms relevant for causing endocrine disruption in marine species. Despite observations of reduced TBT sediment concentrations in many marine sediments over the recent decades, contaminant hotspots are still prevalent worldwide. Consequently, efforts to monitor TBT levels and assessment of potential effects in sentinel species being potentially susceptible to TBT in these locations are still highly warranted.publishedVersio

Overvåking av Indre Oslofjord i 2011

Denne rapporten gir en kortfattet oversikt over resultatene fra overvåkingen foretatt for Fagrådet for vann- og avløpsteknisk samarbeid i Indre Oslofjord i 2011. En mer utfyllende beskrivelse av resultatene er presentert i en vedleggsrapport (l. nr.6372). Undersøkelsene omfatter fysiske, kjemiske og biologiske forhold. Overgjødsling har vært et hovedtema i overvåkingen, men miljøgiftsproblematikk er nå også inkludert. Overvåkingen i 2011 ble gjennomført av Norsk institutt for vannforskning (NIVA) i samarbeid med Biologisk Institutt ved Universitetet i Oslo (UiO). Havforskningsinstituttet (HI) har også vært involvert.Fagrådet for vann- og avløpsteknis

The dynamic analysis of continuous-time life-cycle savings growth models

Working with the framework of a continuous-time overlapping-generations model, this paper examines equilibrium growth paths (consistent with perfect foresight). In particular, we develop a methodology for characterizing the adjustment paths converging to new stationary states following exogenous shocks. The solution technique yields sequences of derivatives approximating the true dynamic paths and bounds for the errors of approximation. In practice, aggregating behavior over discrete-time intervals can save a great deal of effort -- considerably enhancing the set of models feasible for analysis; our error bounds enable us to aggregate without compromising our results to an unknown degree.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26597/1/0000138.pd

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements