Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2006
Forfattere
Bernt Olav HoelSammendrag
Utvikling av system for årlige, tidlige prognoser for mathvetekvalitet
Sammendrag
During snowmelt Oslo airport has on repeated occations experienced the formation of large meltwater ponds due to impermeable ice forming below the snowcover. The airport is situated on a large glacial outwash plane with coarse sandy gravely sediments, hence the area normaly has a high infiltration capacity. Focussed infiltration can cause fast transport of contaminants to the groundwater, hence improved understanding of the processes determining where and how the focussed infiltration takes place is important. Previously the melting process has been monitored successfully on a small scale (4 m2) using a two dimensional grid of permanently installed electrodes (French and Binley, 2004). In the present work snowmelt infiltration was monitored by time-lapse measurements of electrical resistivity using grounded electrodes on 4 and 20 m2 plots and a capacitively coupled resistivity system (Ohmmapper, Geometrics) on a larger scale. While the smaller scale systems provide 3D images the capacitively coupled system was used to monitor changes in two dimensional vertical sections in a retention pond adjacent to one of the runways. The area covered by 4 lines was 170 m by 340 m. The initial data were collected late in the spring (2006) during the final stages of the snowmelt. The lines were repeated later in the year when the soil profile was dryer. The lines show good consistency in the description of the general geology of the subsurface and the time-lapse changes describe the infiltration pattern that occurred during snowmelt and subsequent drainage. The surveys provide useful information about the differences in spatial distribution of snowmelt infiltration at different scales. And there are good indications that capacitively coupled resistivity surveys can be used to describe infiltration processes at relatively large spacio-temporal scales. References French, H. and A. Binley, 2004, Snowmelt infiltration: monitoring temporal and spatial variability using time-lapse geophysics, J. Hydrology, 297, 174-186
Sammendrag
During snowmelt Oslo airport has on repeated occations experienced the formation of large meltwater ponds due to impermeable ice forming below the snowcover. The airport is situated on a large glacial outwash plane with coarse sandy gravely sediments, hence the area normaly has a high infiltration capacity. Focussed infiltration can cause fast transport of contaminants to the groundwater, hence improved understanding of the processes determining where and how the focussed infiltration takes place is important. Previously the melting process has been monitored successfully on a small scale (4 m2) using a two dimensional grid of permanently installed electrodes (French and Binley, 2004). In the present work snowmelt infiltration was monitored by time-lapse measurements of electrical resistivity using grounded electrodes on 4 and 20 m2 plots and a capacitively coupled resistivity system (Ohmmapper, Geometrics) on a larger scale. While the smaller scale systems provide 3D images the capacitively coupled system was used to monitor changes in two dimensional vertical sections in a retention pond adjacent to one of the runways. The area covered by 4 lines was 170 m by 340 m. The initial data were collected late in the spring (2006) during the final stages of the snowmelt. The lines were repeated later in the year when the soil profile was dryer. The lines show good consistency in the description of the general geology of the subsurface and the time-lapse changes describe the infiltration pattern that occurred during snowmelt and subsequent drainage. The surveys provide useful information about the differences in spatial distribution of snowmelt infiltration at different scales. And there are good indications that capacitively coupled resistivity surveys can be used to describe infiltration processes at relatively large spacio-temporal scales. References French, H. and A. Binley, 2004, Snowmelt infiltration: monitoring temporal and spatial variability using time-lapse geophysics, J. Hydrology, 297, 174-186
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Bent Braskerud (permisjon)Sammendrag
Menneskelig aktivitet kan skape erosjon og grumset vann. Fangdammer lages for å bedre vannkvaliteten i bekker og redusere oppfyllingen av reservoar. Selv om anleggene er små og grunne, og vannets oppholdstid kort, viser langvarige undersøkelser at 50-70 % av partiklene kan fjernes på varig basis. Selv leire som normalt har lang bunnfellingstid holdes tilbake i de konstruerte våtmarkene. Denne artikkelen viser hvordan dette er mulig, og gir samtidig noen enkle råd om konstruering.
Sammendrag
Det er ikke registrert sammendrag
Rapport – Tiltak for oppstart av biogassproduksjon III
Tormod Briseid, Ove Bergersen, Roar Linjordet
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Nina TrandemSammendrag
Det er ikke registrert sammendrag
Sammendrag
Ulike metoder for å stimulere deklorering av DDT i sedimenter er undersøkt; ex-situ behandling av oppgravde masser i biopiles (hauger), in-situ behandling for strandkantmaterialer (in-situ land) og under vann (in-situ vann). Behandlingene ble optimalisert for å oppnå reduserende forhold og for å stimulere reduktiv omdanning av DDT til DDD. Under behandlingsforhold i dette prosjektet, var 30 ukers behandlingstid for kort tid til å bekrefte omdanning av DDT, kun trender ble observert. Kombinasjonen innstråling og plastdekke viste at en kan opprettholde en temperatur på 25-30°C i store deler av ranken ved lufttemperaturer rundt 10°C. Disse temperaturene er funnet gunstige for nedbryting av DDT. Også ved synkende lufttemperatur opprettholdes en temperatur høy nok til å stimulere nedbrytning. Underlag med 5 cm isopor hadde god evne til å hindre reduksjon i jordtemperaturen i nedre lag av jordmassene i ranken. Ulike tilsetningsmaterialer for å skape anaerobe forhold ble sammenlignet. Kumøkk og potetrev (biprodukt fra potetindustrien) gav størst reduksjon i oksygennivå
Forfattere
Peder GjerdrumSammendrag
Most (all?) equipment waste timber by turning 10% of valuable solid wood into sawdust and allowance. The presentation discusses the problem and suggests a technology project to splitting blocks of modest size with new, strong materials for thin kerfs and optimised in yield and product quality rather than in speed.