188 research outputs found
Renormalization in periodically driven quantum dots
We report on strong renormalization encountered in periodically driven
interacting quantum dots in the non-adiabatic regime. Correlations between lead
and dot electrons enhance or suppress the amplitude of driving depending on the
sign of the interaction. Employing a newly developed flexible renormalization
group based approach for periodic driving to an interacting resonant level we
show analytically that the magnitude of this effect follows a power law. Our
setup can act as a non-Markovian, single-parameter quantum pump.Comment: 6 pages, 3 figure
Overvåking av kystvann i vannområde Hardanger 2022
Prosjektleder: Anders RuusOvervåkingen av kystvann i vannområdet Hardanger i 2022 viste følgende: Mhp. de fysisk-kjemiske kvalitetselementene viste oksygen(minimum-) konsentrasjoner moderat tilstand på stasjon Lind1 og god tilstand på stasjonene Sø7/2 og S22Sør. Siktedypet tilsvarte dårlig tilstand på samtlige av disse tre stasjonene. Vannregionspesifikke stoffer i vann (metaller; særlig sink) oversteg grenseverdiene (EQS) på alle stasjoner hvor vann ble analysert (Lind1, Sø7/2, S22Sør og S1/4). Ingen analyserte prioriterte stoffer oversteg grenseverdiene (EQS) i overflatevann. Konsentrasjoner av kvikksølv i blåskjell var derimot for høye til å klassifisere kjemisk tilstand som god på samtlige stasjoner hvor blåskjell ble analysert. Konsentrasjoner av fluorid i sjøvann var i hovedsak lavere enn kvantifiseringsgrensen på 1,5 mg/L. gjennomsnittlige konsentrasjoner av fluorid i blåskjell var lave (1,53- 2,24 mg/kg våtvekt). Det ble kun observert konsentrasjoner av thallium på ≤0,05 μg/L i overflatevann. Tl ble funnet i blåskjell i gjennomsnittskonsentrasjoner på 0,003-0,005 mg/kg våtvekt.Boliden Odda AS, Tizir Titanium & Iron AS og Fluorsid Noralf ASpublishedVersio
ESPIAL - Data review and evaluation of historical data (WP1)
Prosjektleder Ailbhe MackenThe present report details the outcome of work package 1 of ESPIAL, with the aim of compiling the historical data from previous surveys at the aluminium sites in a common database and further to analyse the data. A graphical data displaying tool was developed as a custom interactive tool for data visualisations and was designed to be intuitive and user friendly. The main outcomes and findings of this work package can be summarized as follows: Polycyclic aromatic hydrocarbons (PAHs) constitute most data in the database; There is a decent amount of data on sediment samples in the data base, however these do not form time series; Most time series available in the data base are on blue mussel from Sunndal and northern horsemussel from Årdal; Most time series show a declining tendency; All statistically significant PAH time trends show declining concentrations; The database is likely not complete, and more data could be available; The graphical data displaying tool is a promising aid for instant insight in concentrations and time series of different analytes in environmental samples, historically collected in the vicinity of the smelters; The graphical data displaying tool makes it possible to view concentrations and trends in relation to the EQSs, giving insight in chemical status and sites of interest, in terms of possible need of remedial action or natural recovery.Aluminiumindustriens Miljøsekretariat (AMS)publishedVersio
Miljøgifter i en urban fjord, 2014
This programme, “Environmental Contaminants in an Urban Fjord” has covered sampling and analysis of organisms in a marine food web of the Inner Oslofjord, in addition to samples of sediment, blue mussel and polychaetes at selected locations in the fjord. The programme also included inputs of pollutants via surface water (storm water). Results from other monitoring programmes such as "Contaminants in coastal areas" (MILKYS) and "Riverine inputs and direct discharges to Norwegian coastal waters" (RID), as well as results from other input measurements to the inner Oslofjord, and measurements of contaminants at Bekkelaget sewage treatment plant are referred and placed in context with the results of the present programme. A vast number of chemical parameters have been quantified, and the report serves as valuable documentation of the concentrations of these chemicals in different compartments of the Inner Oslofjord marine ecosystem. Furthermore, this report presents relationships between the contaminant concentrations and various biological variables.Dette programmet, "Miljøgifter i en Urban Fjord" har omfattet prøvetaking og analyse av organismer i en marin næringskjede i Indre Oslofjord, i tillegg til prøver av sediment, blåskjell og børstemark på utvalgte lokaliteter i fjorden i 2014. Programmet omfattet også undersøkelser av tilførsler av miljøgifter via overvann. Resultater fra andre overvåkingsprogrammer som "Miljøgifter i kystnære områder" (MILKYS) og "Elvetilførselsprogrammet" (RID), og resultater fra tilførselsundersøkelser, samt målinger av miljøgifter ved Bekkelaget kloakkrenseanlegg er omtalt og satt i sammenheng med resultatene fra den foreliggende undersøkelsen.
...Miljødirektorate
Land-cover, climate and fjord morphology drive differences in organic matter and nutrient dynamics in two contrasting northern river-fjord systems
Climate and land-use changes are leading to impacts on individual ecosystems as well as shifts in transfer dynamics between interconnected systems. At the land-ocean interface, changes in riverine inputs of organic matter (OM) and nutrients have the potential to lead to shifts in coastal carbon and nutrient cycling with consequences for ecosystem structure and function. In this study, we assess OM and nutrient dynamics for two contrasting Norwegian river-to-fjord systems: a boreal system with a forested catchment draining into a narrow fjord (‘narrow boreal system’), and a subarctic system where lowland forests and mountainous regions drain into a broad fjord (‘broad subarctic system’). We characterized seasonal organic carbon and nutrient concentrations and DOM absorption properties for samples collected along transects from river to outer fjord during 2015/2016. While differences in catchment properties drove contrasts in river chemistry between the two study rivers, fjord morphology and hydrodynamics as well as dissolved organic carbon (DOC) and nutrient concentrations in marine receiving waters predicted water-chemistry patterns along the transect. The narrow boreal system, with high riverine DOC and nutrient concentrations, was structured mainly by a horizontal salinity gradient from river to outer fjord, with limited impact of seasonality. In contrast, the broad subarctic system tended to be dominated by vertical salinity stratification, with strong between-date differences in surface water salinity linked to seasonality in river discharge. These dynamics were also reflected in the strong horizontal gradients in DOC, nutrients and DOM properties in the narrow boreal system, in contrast to the broad subarctic system, where strong seasonality paired with a lack of strong contrast between riverine and marine concentrations of DOC and most nutrients led to an uncoupling between salinity and other water chemistry variables. In the narrow boreal system, terrestrial OM dominated both the particulate and dissolved OM pools, while OM in the broad subarctic system was derived primarily from marine phytoplankton. Non-linear declines in NO3 + NO2 were observed consistently in the boreal system and during the productive spring season in the subarctic system, suggesting biological uptake and a potentially important role of these rivers as sources of bioavailable N to coastal ecosystems. The results from these two case studies highlight the complex and interacting effects of catchment land-cover, river water chemistry and discharge, fjord morphometry and hydrodynamics in structuring the transport, fate and potential impacts of terrestrially-derived nutrients and organic matter in northern coastal environments
Possible adverse impact of contaminants on Atlantic cod population dynamics in coastal ecosystems
While many in-laboratory ecotoxicological studies have shown the adverse impact of pollutants to the fitness of an individual, direct evidence from the field on the population dynamics of wildlife animals has been lacking. Here, we provide empirical support for a negative effect of pollution on Atlantic cod (Gadus morhua) population dynamics in coastal waters of Norway by combining unique time series of juvenile cod abundance, body size, environmental concentration of toxic contaminants and a spatially structured population dynamics model. The study shows that mercury concentration might have decreased the reproductive potential of cod in the region despite the general decline in the environmental concentration
of mercury, cadmium and hexachlorobenzene since the implementation of national environmental laws. However, some cod populations appeared to be more resistant to mercury pollution than others, and the strength and shape of mercury effect on cod reproductive potential was fjord-specific. Additionally, cod growth rate changed at scales smaller than fjords with a gradient related to the exposure to the open ocean and offshore cod. These spatial differences in life-history traits emphasize the importance of local
adaptation in shaping the dynamics of local wildlife populations. Finally, this study highlights the possibility to mitigate pollution effects on natural populations by reducing the overall pollution level, but also reveals that pollution reduction alone is not enough to rebuild local cod populations. Cod population recovery probably requires complementary efforts on fishing regulation and habitat restoration.acceptedVersio
In vivo bioaccumulation of contaminants from historically polluted sediments - Relation to bioavailability estimates
Many contaminants are recalcitrant against degradation. Therefore, when primary sources have been discontinued, contaminated sediments often function as important secondary pollution sources. Since the management and potential remediation of contaminated marine sediments may be very costly, it is important that the environmental risks of contaminants present in these sediments and benefits of remediation are evaluated as accurately as possible. The objective of this study was to evaluate the bioavailability of common organochlorine contaminants and polycyclic aromatic hydrocarbons (PAHs) in selected polluted sediments from Norway by simple generic sorption models (free energy relationships), as well as by pore water concentration measurements. Furthermore, the aim was to predict bioaccumulation from these bioavailability estimates for comparison with in vivo bioaccumulation assessments using ragworm (Nereis virens) and netted dogwhelk (Hinia reticulata). Predicted biota-to-sediment accumulation factors (BSAFs) derived from pore water concentration estimates were in better agreement with the bioaccumulation observed in the test organisms, than the generic BSAFs expected based on linear sorption models. The results therefore support that site-specific evaluations of bioaccumulation provide useful information for more accurate risk assessments. A need for increased knowledge of the specific characteristics of benthic organisms, which may influence the exposure, uptake and elimination of contaminants, is however emphasized.acceptedVersio
Maternal transfer and occurrence of siloxanes, chlorinated paraffins, metals, PFAS and legacy POPs in herring gulls (Larus argentatus) of different urban influence
Urban herring gulls (Larus argentatus) are exposed to contaminants from aquatic, terrestrial and anthropogenic sources. We aim to assess if differences in urbanisation affect ecological niche and contaminant concentrations in female herring gulls. Furthermore, we investigated maternal transfer from mothers to eggs for all the target compounds, including chlorinated paraffins (CPs) and cyclic volatile methyl siloxane (cVMSs), which to our knowledge have not been assessed in herring gulls previously. We compare concentrations of legacy and emerging contaminants and metals in blood and eggs between two herring gull colonies located 51 km apart, in the urban influenced Norwegian Oslofjord. While both colonies are within an urbanised area, the inner fjord is more so, as it is surrounded by Oslo, the capital and largest city in Norway Stable isotopes of carbon and nitrogen indicated a more marine ecological niche in the outer than the inner fjord colony, although with overlap. Persistent organic pollutant (POP) concentrations were similar in the inner and outer fjord colonies, while the short-chained chlorinated paraffins (SCCP), which are recently added to the Stockholm convention and contaminants of emerging concern (CECs) varied, with higher concentrations of SCCP and the cVMS decamethylcyclopentasiloxane (D5) in females and eggs of the inner fjord colony. Per- and polyfluorinated substances (PFAS) concentrations were higher in the outer fjord colony, likely linked to releases from a point-source (airport and waste management facility with open access to food waste). In blood, chlorinated paraffins contributed most the total lipophilic contaminants (inner: 78%, outer: 56%), while polychlorinated biphenyls (PCBs) were the most abundant lipophilic contaminants in eggs (inner: 62%, outer: 46%). Dechloranes and brominated flame retardants (BFRs) were detected in few samples. Maternal transfer, assessed by egg to blood ratios, of cVMSs were similar to the POPs with mean log ratio 0.39 (D5), while it was lower for SCCPs, with log ratios-0.77. Our results indicate comparable POP exposure of the herring gulls in the inner and outer Oslofjord, likely due to overlap in ecological niches between the colonies and wide distribution of POPs. The differences between the colonies in concentrations of PFAS, cVMS and CPs shows that point source exposures and urban influence may be more important than ecological niche for these compounds.publishedVersio
Health and environmental risk evaluation of microorganisms used in bioremediation. Scientific Opinion of the Panel on Microbial Ecology of the Norwegian Scientific Committee for Food Safety
In 2015, The Norwegian Environment Agency requested the Norwegian Scientific Committee
for Food Safety (VKM) to collate an overview of bioremediation of polluted ground based on
bioaugmentation described in literature for the degradation of various types of pollutants,
(including hydrocarbons, heavy metals, chlorinated compounds, explosives etc.).The
assessment of genetically modified microorganisms (GMO), phytoremediation,
bioremediation based on natural attenuation, bio-stimulation or biodegradation, including
composting, are not included in this report
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