L'aquaculture intensive est considérée comme une source de pollution. Les interactions étroites entre le milieu d'élevage et l'écosystème où est implanté l'élevage confèrent des caractères particuliers à cette pollution. Les formes de pollution par l'aquaculture sont variées : pollutions organique, chimique, bactériologique, génétique etc. Les flux polluants peuvent être importants localement et géographiquement. On estime que la production d'une tonne de saumons implique 1 km' marin, et que les élevages norvégiens contribuent pour 8 % et 14 % de l'azote et du phosphore respectivement rejetés en mer du Nord. La législation n'est pas adaptée aux problèmes tels qu'ils se posent en pisciculture. Une législation européenne plutôt axée sur le contrôle des intrants dans l'aliment semble se profiler avec l'exemple danois. Le moyen le plus rapide de réduire la pollution générée par l'aquaculture semble être, pour l'instant, d'abaisser la quantité d'aliments déversés par augmentation de la valeur énergétique de ceux-ci (ce qui diminuera la quantité de matières en suspension), et de remplacer une partie des protéines par des lipides. La mise en oeuvre de ce type d'aliment demande toutefois une technicité élevée. L'avenir des traitements en aval semble limité par le caractère très dilué des polluants et les grands volumes d'eau à traiter. L'aquaculture en tant que production dépendante de l'Environnement peut être un lien privilégié pour des études sur le coût de l'Environnement. ; Aquaculture is often considered as a source of pollution. The pollution associated with aquaculture has special features due to the fact that the fish-farming environment and the surrounding ecosystem are inextricably linked. There are a variety of forms of pollution connected with aquaculture : organic pollution, chemical pollution, bacteriological pollution, genetic pollution etc.The amount of pollutants may be high in the near vicinity of the fish farm and also relatively high, in proportion to the total pollution,further afield. It is estimated that the production of a metric ton of salmon involves a sea area of 1 sq km and that Norwegian fish farms contribute 8 % of nitrogenous and 14 % of phosphates discharged into the North Sea. The law is not adapted to such problems as those encountered in fish-farming. European regulations, inspired by Danish legislation, primarily seeking to control the composition of foodstuffs seem to be in preparation. The quickest way to reduce pollution produced by aquaculture seems for the moment to be by reducing the quantity of food used, by increasing it's calorific value (thereby reducing the quantity of suspended solids) and byreplacing a part of the proteins with lipids.The introduction of this type of food stuff however demands a high degree of technical know-how. The future of downstream water treatment seems to be limited by the difficulty of treating the low levels of pollutants and the large volumes involved. Environment sensitive aquaculture can serve as a model for studies on environmental cost.
Proportional methods are used either for apportioning seats to states in proportion to their respective populations, or for allocating seats to lists in proportion to their respective scores in a poll. A family of such methods has been extensively studied and used. Generalizes them as 'multiplicative methods', and shows that there is another family, 'additive methods', that generalizes the greatest remainders method. (Abstract amended)
International audience ; Mid infrared (3-12 µm) laser sources are essential for applications such as optical counter-measures (missile jamming) for military and civil aircraft security or remote chemical sensing. The principle of those sources is based on non linear effect: a short wavelength laser emission (1 or 2 µm) is converted into two long wavelength laser emissions, with complementary energies, inside a non linear crystal in an Optical Parametric Oscillator (OPO). The first critical parameter for our applications is the transparency of the crystals in the mid-IR range. However, classical non linear oxide crystals, which have a transparency limited to 4 µm due to multiphonon absorptions, are not appropriate. Thus, to go beyond this limit, non oxide materials are required like phosphides, selenides sulfides… Moreover, other important parameters are the crystal's resistance to high power and its non linear coefficients which have a direct influence on the energy conversion efficiency. ZnGeP2 (ZGP) presents a good compromise between these properties and is a ternary compound of choice considering the applications cited above. In this work, the high quality ZGP single crystal processing will be presented. It is divided into three main steps which will be precisely described: i) The chemical synthesis from high purity elements Zn, Ge and P which is carried out in a special designed furnace. The main difficulty of this step is to complete the chemical reaction while avoiding the reactor explosion which can occur because of the high vapor pressure of volatile compounds. ii) The crystal growth which is performed using the vertical Bridgman method. iii) Annealing post-treatments which are necessary to reduce the residual absorption around 2 µm. The absorption coefficient at this wavelength, which is the pumping wavelength for a ZGP based OPO, has to be as low as possible to increase the energy conversion efficiency. Crack free ZGP single crystals were grown following our process (Figure 1). Structural and optical ...
International audience ; Mid infrared (3-12 µm) laser sources are essential for applications such as optical counter-measures (missile jamming) for military and civil aircraft security or remote chemical sensing. The principle of those sources is based on non linear effect: a short wavelength laser emission (1 or 2 µm) is converted into two long wavelength laser emissions, with complementary energies, inside a non linear crystal in an Optical Parametric Oscillator (OPO). The first critical parameter for our applications is the transparency of the crystals in the mid-IR range. However, classical non linear oxide crystals, which have a transparency limited to 4 µm due to multiphonon absorptions, are not appropriate. Thus, to go beyond this limit, non oxide materials are required like phosphides, selenides sulfides… Moreover, other important parameters are the crystal's resistance to high power and its non linear coefficients which have a direct influence on the energy conversion efficiency. ZnGeP2 (ZGP) presents a good compromise between these properties and is a ternary compound of choice considering the applications cited above. In this work, the high quality ZGP single crystal processing will be presented. It is divided into three main steps which will be precisely described: i) The chemical synthesis from high purity elements Zn, Ge and P which is carried out in a special designed furnace. The main difficulty of this step is to complete the chemical reaction while avoiding the reactor explosion which can occur because of the high vapor pressure of volatile compounds. ii) The crystal growth which is performed using the vertical Bridgman method. iii) Annealing post-treatments which are necessary to reduce the residual absorption around 2 µm. The absorption coefficient at this wavelength, which is the pumping wavelength for a ZGP based OPO, has to be as low as possible to increase the energy conversion efficiency. Crack free ZGP single crystals were grown following our process (Figure 1). Structural and optical quality characterizations will be presented and discussed. A very low absorption coefficient at 2 µm (~0.1 cm-1) was obtained.OPO tests as well as bigger crystal processing are currently in progress.
Cet article présente les résultats d'une recherche pluridisciplinaire (géochimie, sociologie) portant sur l'accroissement observé des concentrations d'argent sous la forme particulaire et nanoparticulaire (Ag et nanoAg) dans les milieux aquatiques de l'estuaire de la Gironde. Il propose conjointement d'analyser les risques d'une contamination des milieux aquatiques par l'argent et d'observer le processus de construction sociale et politique de ce risque par les gestionnaires de l'eau, les autorités sanitaires, les agences et comités d'expertise et d'évaluation des risques, des associations environnementales et des industriels utilisateurs d'argent. La mise à jour de quatre types de construction du risque permet de comprendre les différentes logiques d'argumentation mobilisées. Cette coopération scientifique pluridisciplinaire ouvre des perspectives sur les problématiques santé-environnement en diffusant des savoirs pour l'action et en favorisant la réflexivité des acteurs locaux confrontés au problème émergent de la concentration de l'argent dans les milieux aquatiques. / This article presents the results of multidisciplinary research (geochemistry, sociology) into the increasing concentrations of silver (Ag and nanoAg) in the environment and their potential impact on aquatic environments. We investigate simultaneously the risk of contamination of these environments by silver and the process of the social and political construction of this risk by water managers, health authorities, agencies and committees responsible for expert evaluations, environmental associations, and potential users of silver or nano-silver. Four updated models of risk construction allow us to understand the logic of arguments mobilized at this stage of the emerging risk. This interdisciplinary cooperation opens up possibilities for dealing with some environmental health issues; it highlights the benefits of an approach aiming to disseminate knowledge to enable action and to promote awareness and analysis by the local stakeholders and ...
Cet article présente les résultats d'une recherche pluridisciplinaire (géochimie, sociologie) portant sur l'accroissement observé des concentrations d'argent sous la forme particulaire et nanoparticulaire (Ag et nanoAg) dans les milieux aquatiques de l'estuaire de la Gironde. Il propose conjointement d'analyser les risques d'une contamination des milieux aquatiques par l'argent et d'observer le processus de construction sociale et politique de ce risque par les gestionnaires de l'eau, les autorités sanitaires, les agences et comités d'expertise et d'évaluation des risques, des associations environnementales et des industriels utilisateurs d'argent. La mise à jour de quatre types de construction du risque permet de comprendre les différentes logiques d'argumentation mobilisées. Cette coopération scientifique pluridisciplinaire ouvre des perspectives sur les problématiques santé-environnement en diffusant des savoirs pour l'action et en favorisant la réflexivité des acteurs locaux confrontés au problème émergent de la concentration de l'argent dans les milieux aquatiques. / This article presents the results of multidisciplinary research (geochemistry, sociology) into the increasing concentrations of silver (Ag and nanoAg) in the environment and their potential impact on aquatic environments. We investigate simultaneously the risk of contamination of these environments by silver and the process of the social and political construction of this risk by water managers, health authorities, agencies and committees responsible for expert evaluations, environmental associations, and potential users of silver or nano-silver. Four updated models of risk construction allow us to understand the logic of arguments mobilized at this stage of the emerging risk. This interdisciplinary cooperation opens up possibilities for dealing with some environmental health issues; it highlights the benefits of an approach aiming to disseminate knowledge to enable action and to promote awareness and analysis by the local stakeholders and ...
Cet article présente les résultats d'une recherche pluridisciplinaire (géochimie, sociologie) portant sur l'accroissement observé des concentrations d'argent sous la forme particulaire et nanoparticulaire (Ag et nanoAg) dans les milieux aquatiques de l'estuaire de la Gironde. Il propose conjointement d'analyser les risques d'une contamination des milieux aquatiques par l'argent et d'observer le processus de construction sociale et politique de ce risque par les gestionnaires de l'eau, les autorités sanitaires, les agences et comités d'expertise et d'évaluation des risques, des associations environnementales et des industriels utilisateurs d'argent. La mise à jour de quatre types de construction du risque permet de comprendre les différentes logiques d'argumentation mobilisées. Cette coopération scientifique pluridisciplinaire ouvre des perspectives sur les problématiques santé-environnement en diffusant des savoirs pour l'action et en favorisant la réflexivité des acteurs locaux confrontés au problème émergent de la concentration de l'argent dans les milieux aquatiques. / This article presents the results of multidisciplinary research (geochemistry, sociology) into the increasing concentrations of silver (Ag and nanoAg) in the environment and their potential impact on aquatic environments. We investigate simultaneously the risk of contamination of these environments by silver and the process of the social and political construction of this risk by water managers, health authorities, agencies and committees responsible for expert evaluations, environmental associations, and potential users of silver or nano-silver. Four updated models of risk construction allow us to understand the logic of arguments mobilized at this stage of the emerging risk. This interdisciplinary cooperation opens up possibilities for dealing with some environmental health issues; it highlights the benefits of an approach aiming to disseminate knowledge to enable action and to promote awareness and analysis by the local stakeholders and officials who face this emerging problem.
Cet article présente les résultats d'une recherche pluridisciplinaire (géochimie, sociologie) portant sur l'accroissement observé des concentrations d'argent sous la forme particulaire et nanoparticulaire (Ag et nanoAg) dans les milieux aquatiques de l'estuaire de la Gironde. Il propose conjointement d'analyser les risques d'une contamination des milieux aquatiques par l'argent et d'observer le processus de construction sociale et politique de ce risque par les gestionnaires de l'eau, les autorités sanitaires, les agences et comités d'expertise et d'évaluation des risques, des associations environnementales et des industriels utilisateurs d'argent. La mise à jour de quatre types de construction du risque permet de comprendre les différentes logiques d'argumentation mobilisées. Cette coopération scientifique pluridisciplinaire ouvre des perspectives sur les problématiques santé-environnement en diffusant des savoirs pour l'action et en favorisant la réflexivité des acteurs locaux confrontés au problème émergent de la concentration de l'argent dans les milieux aquatiques. / This article presents the results of multidisciplinary research (geochemistry, sociology) into the increasing concentrations of silver (Ag and nanoAg) in the environment and their potential impact on aquatic environments. We investigate simultaneously the risk of contamination of these environments by silver and the process of the social and political construction of this risk by water managers, health authorities, agencies and committees responsible for expert evaluations, environmental associations, and potential users of silver or nano-silver. Four updated models of risk construction allow us to understand the logic of arguments mobilized at this stage of the emerging risk. This interdisciplinary cooperation opens up possibilities for dealing with some environmental health issues; it highlights the benefits of an approach aiming to disseminate knowledge to enable action and to promote awareness and analysis by the local stakeholders and ...
Cet article présente les résultats d'une recherche pluridisciplinaire (géochimie, sociologie) portant sur l'accroissement observé des concentrations d'argent sous la forme particulaire et nanoparticulaire (Ag et nanoAg) dans les milieux aquatiques de l'estuaire de la Gironde. Il propose conjointement d'analyser les risques d'une contamination des milieux aquatiques par l'argent et d'observer le processus de construction sociale et politique de ce risque par les gestionnaires de l'eau, les autorités sanitaires, les agences et comités d'expertise et d'évaluation des risques, des associations environnementales et des industriels utilisateurs d'argent. La mise à jour de quatre types de construction du risque permet de comprendre les différentes logiques d'argumentation mobilisées. Cette coopération scientifique pluridisciplinaire ouvre des perspectives sur les problématiques santé-environnement en diffusant des savoirs pour l'action et en favorisant la réflexivité des acteurs locaux confrontés au problème émergent de la concentration de l'argent dans les milieux aquatiques. / This article presents the results of multidisciplinary research (geochemistry, sociology) into the increasing concentrations of silver (Ag and nanoAg) in the environment and their potential impact on aquatic environments. We investigate simultaneously the risk of contamination of these environments by silver and the process of the social and political construction of this risk by water managers, health authorities, agencies and committees responsible for expert evaluations, environmental associations, and potential users of silver or nano-silver. Four updated models of risk construction allow us to understand the logic of arguments mobilized at this stage of the emerging risk. This interdisciplinary cooperation opens up possibilities for dealing with some environmental health issues; it highlights the benefits of an approach aiming to disseminate knowledge to enable action and to promote awareness and analysis by the local stakeholders and ...
Similarities and differences in the submicron atmospheric aerosol chemical composition are analyzed from a unique set of measurements performed at 21 sites across Europe for at least one year. These sites are located between 35 and 62°N and 10° W – 26°E, and represent various types of settings (remote, coastal, rural, industrial, urban). Measurements were all carried out on-line with a 30-min time resolution using mass spectroscopy based instruments known as Aerosol Chemical Speciation Monitors (ACSM) and Aerosol Mass Spectrometers (AMS) and following common measurement guidelines. Data regarding organics, sulfate, nitrate and ammonium concentrations, as well as the sum of them called non-refractory submicron aerosol mass concentration ([NR-PM1]) are discussed. NR-PM1 concentrations generally increase from remote to urban sites. They are mostly larger in the mid-latitude band than in southern and northern Europe. On average, organics account for the major part (36–64%) of NR-PM1 followed by sulfate (12–44%) and nitrate (6–35%). The annual mean chemical composition of NR-PM1 at rural (or regional background) sites and urban background sites are very similar. Considering rural and regional background sites only, nitrate contribution is higher and sulfate contribution is lower in mid-latitude Europe compared to northern and southern Europe. Large seasonal variations in concentrations (μg/m³) of one or more components of NR-PM1 can be observed at all sites, as well as in the chemical composition of NR-PM1 (%) at most sites. Significant diel cycles in the contribution to [NR-PM1] of organics, sulfate, and nitrate can be observed at a majority of sites both in winter and summer. Early morning minima in organics in concomitance with maxima in nitrate are common features at regional and urban background sites. Daily variations are much smaller at a number of coastal and rural sites. Looking at NR-PM1 chemical composition as a function of NR-PM1 mass concentration reveals that although organics account for the major fraction of NR-PM1 at all concentration levels at most sites, nitrate contribution generally increases with NR-PM1 mass concentration and predominates when NR-PM1 mass concentrations exceed 40 μg/m³ at half of the sites. ; This study was partially supported by the European Union's projects ACTRIS (EU FP7-262254) and ACTRIS-2 (EU Horizon 2020–654109). COST Action CA16109 COLOSSAL, Chemical On-Line cOmpoSition and Source Apportionment of fine aerosoL, is acknowledged. The ACSM observations at Birkenes was funded by the Norwegian Ministry of Climate and Environment Strategic Institute Program. IDAEA-CSIC (3 datasets: BCN, MSA, MSY) was partially supported by the Spanish Ministry of Economy and Competitiveness and FEDER funds under the PRISMA project (CGL 2012-39623-C02-1). The London measurements were supported by the UK National Research Council through the ClearfLo project and a PhD studentship (grant refs. NE/H008136/1 and NE/I528142/1) and the Department of Environment, Food and Rural Affairs (DEFRA). ECPL personel, namely Nikolaos Mihalopoulos, Aikaterini Bougiatioti and Iasonas Stavroulas acknowledge support by the project "Panhellenic infrastructure for atmospheric composition and climate change, PANACEA" (MIS 5021516) which is implemented under the Action "Reinforcement of the Research and Innovation Infrastructure", funded by the Operational Programme" Competitiveness, Entrepreneurship and Innovation" (NSRF 2014–2020) and co-financed by Greece and the European Union (European Regional Development Fund). IMT Lille Douai acknowledges financial support from the CaPPA (Chemical and Physical Properties of the Atmosphere) project funded by the French National Research Agency (ANR) through the PIA (Programme d'Investissement d'Avenir) under contract ANR-11-LABX-0005-01, and two CPER projects funded by the French Ministry of Higher Education and Research, the CNRS, the Regional Council "Hauts-de-France" and the European Regional Development Fund (ERDF): Climibio, and IRENI (additionally financed by the Communauté Urbaine de Dunkerque). S. Zhang thanks IMT Lille Douai and the Regional Council "Hauts-de-France" for her PhD grant. Prague co-authors would like to acknowledge a Czech MEYS's project under INTER-EXCELENCE INTERCOST program under grant agreement LTC18068 and from European Regional Development Fund-Project under the grant ACTRIS-CZ RI (CZ.02.1.01/0.0/0.0/16_013/0001315). EPA Ireland, Department of Communications, Climate Action and Environment (DCCAE) and the European Union's Seventh Framework Programme (FP7/2007–2013) project BACCHUS under grant agreement n_603445 are acknowledged for research support at Mace Head. The physical measurements were also funded by the German Ultrafine Aerosol Network GUAN, which was jointly established with help of the German Federal Environment Ministry (BMU) grants F&E 370343200 (German title: "Erfassung der Zahl feiner und ultrafeiner Partikel in der Auβenluft"), 2008–2010, and F&E 371143232 (German title: "Trendanalysen gesundheitsgefährdender Fein-und Ultrafeinstaubfraktionen unter Nutzung der im German Ultrafine Aerosol Network (GUAN) ermittelten Immissionsdaten durch Fortführung und Interpretation der Messreihen") 2012–2014. We also acknowledge the WCCAP (World Calibration Center for Aerosol Physics) as part of the WMO-GAW program. The WCCAP is base-funded by the German Federal Environmental Agency (Umweltbundesamt), Germany. Support by the European Regional Development Funds (EFRE – Europe funds Saxony) is gratefully acknowledged. Atmospheric measurements performed in Corsica is part of the ChArMEx project supported by CNRS-INSU, ADEME, Météo-France and CEA in the framework of the multidisciplinary programme MISTRALS (Mediterranean Integrated Studies aT Regional And Local Scales; http://mistrals-home.org/, last access: June 10, 2020). Final data processing of these measurements has been supported by the EMME-CARE (Eastern Mediterranean and Middle East Climate and Atmosphere Research Center) which has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 856612 and the Cyprus Government. The measurements in Switzerland were supported by the Federal Office for the Environment. We thank the International Foundation High Altitude Research Stations Jungfraujoch and Gornergrat (HFSJG) for the opportunity to perform experiments on the Jungfraujoch. ; Peer reviewed
This anthology provides an historical overview of the scientific ideas behind environmental prediction and how, as predictions about environmental change have been taken more seriously and widely, they have affected politics, policy, and public perception. Through an array of texts and commentaries that examine the themes of progress, population, environment, biodiversity and sustainability from a global perspective, it explores the meaning of the future in the twenty-first century. Providing access and reference points to the origins and development of key disciplines and methods, it will encourage policy makers, professionals, and students to reflect on the roots of their own theories and practices
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