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Spreading of waxy Crude Oils on calm weather | Spreading of waxy Crude Oils on calm weather 全文
2018
Brönner, Ute | Johansen, Øistein | Leirvik, Frode | Nordam, Tor | Sørheim, Kristin Rist
Spreading of waxy Crude Oils on calm weather | Spreading of waxy Crude Oils on calm weather 全文
2018
Brönner, Ute | Johansen, Øistein | Leirvik, Frode | Nordam, Tor | Sørheim, Kristin Rist
The objective of this paper is to provide a simple extension of the much-used gravity spreading model for oil on calm water to account for the spreading behavior of waxy crude oils in cold waters – including the observed retardation and eventual termination of spreading at certain oil film thicknesses. This peculiar behavior is not predicted by traditional spreading models for oil on calm water (i.e. viscous-gravity spreading models), but may occur due to non-Newtonian oil properties caused by precipitation of wax at low temperatures. To clarify the spreading behavior of such oils, SINTEF has conducted a series of laboratory experiments with a range of waxy oil mixtures. The present paper contains analyses of data from these experiments, including favorable comparisons with calculations by a proposed improved surface spreading model. | Spreading of waxy Crude Oils on calm weather | acceptedVersion
显示更多 [+] 显示较少 [-]Spreading of waxy oils on calm water 全文
2018
Brönner, Ute | Johansen, Øistein | Leirvik, Frode | Nordam, Tor | Sørheim, Kristin R.
The objective of this paper is to provide a simple extension of the much-used gravity spreading model for oil on calm water to account for the spreading behavior of waxy crude oils in cold waters – including the observed retardation and eventual termination of spreading at certain oil film thicknesses. This peculiar behavior is not predicted by traditional spreading models for oil on calm water (i.e. viscous-gravity spreading models), but may occur due to non-Newtonian oil properties caused by precipitation of wax at low temperatures. To clarify the spreading behavior of such oils, SINTEF has conducted a series of laboratory experiments with a range of waxy oil mixtures. The present paper contains analyses of data from these experiments, including favorable comparisons with calculations by a proposed improved surface spreading model.
显示更多 [+] 显示较少 [-]L’azote, si cher à nos campagnes 全文
2016
Génermont, Sophie, | Cellier, Pierre
L’azote, si cher à nos campagnes
显示更多 [+] 显示较少 [-]Potential of copper-tolerant grasses to implement phytostabilisation strategies on polluted soils in South D. R. Congo: Poaceae candidates for phytostabilisation 全文
2016
Boisson, Sylvain | Le Stradic, Soizig | Collignon, Julien | Seleck, Maxime | Malaisse, François | Shutcha, Mylor Ngoy | Faucon, Michel-Pierre | Mahy, Grégory
Potential of copper-tolerant grasses to implement phytostabilisation strategies on polluted soils in South D. R. Congo: Poaceae candidates for phytostabilisation 全文
2016
Boisson, Sylvain | Le Stradic, Soizig | Collignon, Julien | Seleck, Maxime | Malaisse, François | Shutcha, Mylor Ngoy | Faucon, Michel-Pierre | Mahy, Grégory
peer reviewed | Phytostabilisation (i.e. using plants to immobilise contaminants) represents a well-known technology to hamper heavy metal spread across landscapes. In Katanga (D. R. Congo), Microchloa altera, a tolerant grass from the copper hills, was recently identified as a candidate species to stabilise copper in the soil. More than 50 grasses compose this flora, which may be studied to implement phytostabilisation strategies. However, little is known about their phenology, tolerance, reproductive strategy or demography. The present study aims to characterize the other Poaceae that may be used in phytostabilisation purposes based on the following criteria: their ecological distribution, seed production at two times, abundance, soil coverage and the germination percentage of their seeds. We selected seven perennial Poaceae that occur on the copper hills. Their ecological distributions (i.e. species response curves) have been modelled along copper or cobalt gradients with generalized additive models using logic link based on 172 presence/absence samples on three sites. For other variables, a total of 69 quadrats (1 m2) were randomly placed across three sites and habitats. For each species, we compared the number of inflorescence-bearing stems (IBS) by plot, the percentage of cover, the number of seeds by IBS and the estimated number of seeds by plot between sites and habitat. Three species (Andropogon schirensis, Eragrostis racemosa and Loudetia simplex) were very interesting for phytostabilisation programs. They produced a large quantity of seeds and had the highest percentage of cover. However, A. schirensis and L. simplex presented significant variations in the number of seeds and the percentage of cover according to site.
显示更多 [+] 显示较少 [-]Potential of copper-tolerant grasses to implement phytostabilisation strategies on polluted soils in South D. R. Congo : Poaceae candidates for phytostabilisation 全文
2016
Boisson, Sylvain | Le Stradic, Soizig | Collignon, Julien | Séleck, Maxime | Malaisse, François | Ngoy Shutcha, Mylor | Faucon, Michel-Pierre | Mahy, Grégory
Phytostabilisation (i.e. using plants to immobilise contaminants) represents a well-known technology to hamper heavy metal spread across landscapes. Southeastern D.R. Congo, Microchloa altera, a tolerant grass from the copper hills, was recently identified as a candidate species to stabilise copper in the soil. More than 50 grasses compose this flora, which may be studied to implement phytostabilisation strategies. However, little is known about their phenology, tolerance, reproductive strategy or demography. The present study aims to characterize the Poaceae that may be used in phytostabilisation purposes based on the following criteria: their ecological distribution, seed production at two times, abundance, soil coverage and the germination percentage of their seeds. We selected seven perennial Poaceae that occur on the copper hills. Their ecological distributions (i.e. species response curves) have been modelled along copper or cobalt gradients with generalised additive models using logic link based on 172 presence-absence samples on three sites. For other variables, a total of 69 quadrats (1 m²) were randomly placed across three sites and habitats. For each species, we compared the number of inflorescence-bearing stems (IBS) by plot, the percentage of cover, the number of seeds by IBS and the estimated number of seeds by plot between sites and habitat. Three species (Andropogon schirensis, Eragrostis racemosa and Loudetia simplex) were very interesting for phytostabilisation programs. They produced a large quantity of seeds and had the highest percentage of cover. However, A. schirensis and L. simplex presented significant variations in the number of seeds and the percentage of cover according to site.
显示更多 [+] 显示较少 [-]Contribution de la combustion de biomasse sur les niveaux de PM10 dans la Vallée de l’Arve 全文
2014
Chevrier, F. | Močnik, G. | Brulfert, G. | Laurent, J.-P. | Jaffrezo, J.-L. | Besombes, Jean-Luc
Metallothioneins pattern during ontogeny of coastal dolphin, Pontoporia blainvillei, from Argentina 全文
2014
Polizzi, P.S. | Romero, M.B. | Chiodi Boudet, L.N. | Das, Krishna | Denuncio, P.E. | Rodriguez, D.H. | Gerpe, M.S.
Metallothioneins pattern during ontogeny of coastal dolphin, Pontoporia blainvillei, from Argentina 全文
2014
Polizzi, P.S. | Romero, M.B. | Chiodi Boudet, L.N. | Das, Krishna | Denuncio, P.E. | Rodriguez, D.H. | Gerpe, M.S.
peer reviewed | Metallothioneins are signals of metal exposure and widely used in biomonitoring. Franciscana dolphin is an endemic cetacean from the Southwestern Atlantic Ocean, classified as Vulnerable A3d by the IUCN. Metallothionein, copper and zinc in Franciscana were assessed in two geographic groups; one inhabits La Plata River estuary, anthropogenically impacted, and the other inhabits marine coastal ecosystems, with negligible pollution. Despite the environment, hepatic and renal MT concentrations were similar, but there was a declining trend from early to later developmental stages. Metallothionein K/L, Cu and Zn levels corresponded to normal reported ranges. MT was not related with Cd. Fetal concentrations were higher than its mother. These results and the health status of dolphins are suggesting that MT correspond to physiological ranges for the species, and they are closely to homeostasis of Zn and Cu, according to its ontogenetic changes. The information constitutes the first MT information on Franciscana dolphin and can be considered as baseline for the species conservation.
显示更多 [+] 显示较少 [-]Metallothioneins pattern during ontogeny of coastal dolphin, Pontoporia blainvillei, from Argentina 全文
2014
Polizzi, P.S. | Romero, M.B. | Chiodi Boudet, L.N. | Das, K. | Denuncio, P.E. | Rodríguez, D.H. | Gerpe, M.S.
Metallothioneins are signals of metal exposure and widely used in biomonitoring. Franciscana dolphin is an endemic cetacean from the Southwestern Atlantic Ocean, classified as Vulnerable A3d by the IUCN. Metallothionein, copper and zinc in Franciscana were assessed in two geographic groups; one inhabits La Plata River estuary, anthropogenically impacted, and the other inhabits marine coastal ecosystems, with negligible pollution. Despite the environment, hepatic and renal MT concentrations were similar, but there was a declining trend from early to later developmental stages. Metallothionein K/L, Cu and Zn levels corresponded to normal reported ranges. MT was not related with Cd. Fetal concentrations were higher than its mother. These results and the health status of dolphins are suggesting that MT correspond to physiological ranges for the species, and they are closely to homeostasis of Zn and Cu, according to its ontogenetic changes. The information constitutes the first MT information on Franciscana dolphin and can be considered as baseline for the species conservation.
显示更多 [+] 显示较少 [-]How can magnetic resonance imaging (MRI) and particulate contrast agents with finely tuned interfacial properties help understanding particle transport in soil. 全文
2012
Michel, E. | Faure, P. | Guillet, P. | Lafolie, Francois | Neveu, S. | Sammartino, Stéphane | Polidori, A.
Wood burning impact on the ambient air quality of four French cities : Evaluation of the approach by organic tracers | Impact de la combustion du bois sur la qualité de l'air ambiant de quatre villes de France : évaluation de l'approche par traceurs organiques 全文
2009
Pissot, Nicolas | Besombes, Jean-Luc | Leoz-Garziandia, Eva | Jaffrezo, Jean-Luc
Nowadays, promoted as a renewable energy, biomass burning becomes more and more widespread all over the world. In urban and rural areas biomass, mainly wood, is burned for heating, cooking, and waste disposal purposes. This biofuel seems to be an alternative to the rarefaction of the fossil fuel and, moreover it decreases the emission of carbon dioxide causing global warming. However, wood smoke contains various air pollutants such as fine particulate matter (PM10, PM2.5), polycyclic aromatic hydrocarbons (PAHs), benzene, dioxins... and in consequence has an impact on the air quality. In order to estimate the contribution of wood burning on the atmospheric organic aerosol of urban areas, the French ministry of environment (MEEDDAT), called upon this study during the winter 2006/2007, in the French cities of Grenoble, Lille, Strasbourg and Gennevilliers. For this work, different species have been looked after. The global characterization of the atmospheric aerosols has been made taking in account the PM10, the organic carbon (OC), and the elementary carbon (EC). Measurement of biomass burning tracers (levoglucosan, mannosan, and galactosan) has been undertaken, as well as methoxyphenols, which are more specific wood smoke tracers. The analyses of organic tracers by gas chromatography coupled with a mass spectrometer detector (GC/MS) show average concentrations of levoglucosan in the range of 272 ng.m-3 for Gennevilliers to 1 148 ng.m-3 for Grenoble. Mannosan and galactosan have also been measured in all cities but in lower quantities. The methoxyphenols have been detected only in rare occasions and at the limit of detection of the analytical method. PM10 measurements range from 20.6 micro g.m-3 for Gennevilliers to 35.8 micro g.m-3 for Grenoble. At the same time, OC values range from 3.61 micro g.m-3 to 11.15 micro g.m-3. Moreover high correlations have been observed between levoglucosan and OC, respectively 0.80 and 0.86 for Grenoble and Strasbourg. In addition, with respectively 10.98 ng.m-3 and 8.20 ng.m-3, Grenoble and Strasbourg present the highest particulate PAHs average concentrations of the four cities. All these results seem to indicate that Grenoble and Strasbourg are more impacted by the biomass burning than the two other cities. And more particularly in Grenoble where the organic aerosol fraction is very huge, this last phenomenon is typically characteristic of the biomass burning. To conclude, this study shows and confirms the usefulness of levoglucosan as biomass burning tracer and the difficulty to use methoxyphenols as woodsmoke tracers in ambient areas. | De nos jours, l'utilisation du bois en tant que combustible est relativement répandue en France et dans le monde entier. L'augmentation du prix du pétrole et des autres sources d'énergie épuisables va certainement engendrer dans les années à venir une contribution accrue du chauffage domestique au bois. L'utilisation de cette source d'énergie renouvelable pose cependant de nombreux problèmes sur la santé humaine. En effet, la fumée émise lors de la combustion du bois contient un certain nombre de composés polluants, tels que les hydrocarbures aromatiques polycycliques (HAP), le benzène, les fines particules (PM10, PM2,5)... Les émissions de la combustion du bois ont donc un impact sur la qualité de l'air. Cet impact peut être évalué par l'étude de traceurs organiques spécifiques de la combustion du bois identifiables au sein de la composante organique des aérosols. Ces traceurs sont des produits provenant de la combustion de la cellulose et de l'hémicellulose tels que le lévoglucosan, mannosan, galactosan et des composés issus de la thermodégradation de la lignine tels que les méthoxyphénols. Cette méthode a été appliquée à une étude commanditée à l'INERIS par le ministère de l'Écologie, de l'Énergie, du Développement Durable et de l'Aménagement du Territoire (MEEDDAT), en partenariat avec des Associations agréées de la surveillance de la qualité de l'air (AASQA). L'objectif était de caractériser l'influence de la combustion du bois sur la composante organique de l'aérosol atmosphérique en site urbain. Des prélèvements d'aérosols ont été effectués sur une période allant de novembre 2006 à avril 2007, dans quatre grandes villes de France : Grenoble, Lille, Strasbourg, et Gennevilliers. L'analyse par chromatographie gazeuse couplée à un spectromètre de masse (GC/MS) des traceurs organiques les plus stables, lévoglucosan, mannosan et galactosan, confirme l'influence de cette source sur la qualité de l'air des quatre villes. Sur la période d'étude, la concentration moyenne en lévoglucosan varie de 272 ng.m-3 pour la ville de Gennevilliers à 1 148 ng.m-3 pour la ville de Grenoble. La confrontation des résultats de ces traceurs avec les données usuelles de caractérisation de l'aérosol, telles que le carbone organique (OC) et le carbone élémentaire (EC), montre une participation du chauffage au bois plus importante dans les villes de Grenoble et de Strasbourg. Les résultats d'analyse du lévoglucosan obtenus sur la ville de Gennevilliers indiquent une très bonne corrélation avec les HAP particulaires et les PM10. Ces résultats prouvent que la combustion du bois joue un rôle important sur la composition de la matière organique de l'aérosol atmosphérique et sur la pollution particulaire en milieu urbain. En revanche, les méthoxyphénols ont été peu détectés sur les divers échantillons analysés.
显示更多 [+] 显示较少 [-]Cocaïne and metabolites in waste and surface water across Belgium. 全文
2009
Van Nuijs, Alexander | Pecceu, Bert | Theunis, Laetitia | Dubois, Nathalie | Charlier, Corinne | Jorens, Philippe | Bervoets, Lieven | Blust, Ronny | Neels, Hugo | Covaci, Adrian | Aquapôle - ULiège
peer reviewed
显示更多 [+] 显示较少 [-]Inter-species differences for polychlorinated biphenyls and polybrominated diphenyl ethers in marine top predators from the Southern North Sea: Part 2. Biomagnification in harbour seals and harbour porpoises 全文
2009
Weijs, Liesbeth | Dirtu, Alin C | Das, Krishna | Ghorghe, Adriana | Reijnders, Peter | Neels, Hugo | Blust, Ronny | Covaci, Adrian | MARE - Centre Interfacultaire de Recherches en Océanologie - ULiège
peer reviewed | Harbour porpoises (Phocoena phocoena) and harbour seals (Phoca vitulina) were found to differ in the ability to metabolize polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). Biomagnification factors (BMFs), calculated between both predators and their prey (sole – Solea solea and whiting – Merlangius merlangus), had a large range of variation (between 0.5 and 91 for PCBs and between 0.6 and 53 for PBDEs). For the higher chlorinated PCBs and the highest brominated PBDEs, the BMF values in adult males were significantly higher than in the juvenile individuals of both species. BMF values of hexa- to octa-PCBs were the highest, suggesting reduced ability to degrade these congeners. Harbour porpoises had higher BMFs for lower chlorinated PCBs and for all PBDEs compared to harbour seals. Other factors, which may influence biomagnification, such as the octanol–water partition coefficients and the trophic level position measured through stable isotope (d15N) analysis, were found to be of lesser importance to predict biomagnification in the studied food chain.
显示更多 [+] 显示较少 [-]Impacts potentiels de la pollution par l'ozone sur le rendement du blé en Ile-de-France: Analyse de la variabilité spatio-temporelle 全文
2003
Castell, J.F. | Lebard, Stéphanie
