16 research outputs found

    Radioécologie marine

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    New estimation of La Hague contribution to the artificial radioactivity of Norwegian waters (1992-1995) and Barents Sea

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    International audienceA release of 10000 GBq per month of a conservative radionuclide into the central part of the English Channel gives rise to activities (in Bq m-3) of 68-89 at Goury, 50-70 in Cherbourg (5 and 30 km from the waste outlet of La Hague), 25-40 in the Straits of Dover, 4-5 at the entrance of the Norwegian Channel and l-3 at the entrance of the Barents Sea. Taking account of La Hague releases and transit times of 17 and 36 months, a calculation of the contribution of La Hague to the artificial radioactivity of the entrance to the Norwegian Channel and the Barents Sea is given

    FLUXMANCHE radiotracers measurements: A contribution to the dynamics of the English Channel and North Sea

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    International audienceFrom 1986 to 1992, 125Sb released by the nuclear fuel reprocessing plant at La Hague has been used to study the transfer of waters from mid-Channel areas towards the Straits of Dover. Since 1940, these investigations have formed part of the MAST 53 FLUXMANCHE programme and have involved repeated measurements on a Straits of Dover transect. A discussion of the results is presented here which takes into account new information provided by a hydrodynamic model developed in the framework of FLUXMANCHE; it combines knowledge of the monthly fluxes of water trough the Straits of Dover and week-by-week simulation of the 125Sb activities of waters flowing in this aera. It is proposed that soluble radionuclides introduced into the central Channel are transferred towards the Straits of Dover over a time which varies from four to seven months depending on the route taken

    The distribution of artificial radionuclides in the English Channel, southern North Sea, Skagerrak and Kattegat, 1990–1993

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    International audienceThis paper presents the initial results concerning the distribution of artificial radionuclides from research cruises conducted in collaboration by three European institutes as part of an EEC MAST research project. Ten cruises were undertaken covering the English Channel, southern and eastern North Sea, Skagerrak and Kattegat over a period of 2.5 yr. A large number of analyses of four artificial radionuclides (13'Cs, "Tc, '*%b, !%r), which behave conservatively in seawater, provided information about the general distribution of water masses and circulation patterns as well as about single transport events in the study area. Controlled liquid releases from the La Hague nuclear fuel reprocessing plant are transported eastwards, forming a characteristic distribution pattern in the Channel and the southern North Sea. This includes a near-coastal "plume" and a distinct boundary between waters contaminated predominantly by La Hague and by Sellafield. Spatial and temporal distributions of radionuclide ratios were used, for the first time, to calculate transit times from the English Channel to the coast of Jutland. The data published herein provide an essential input to the calibration of numerical models simulating water transport processes. The results demonstrate the continuing usefulness of artificial radionuclides as oceanographic tracers, even at the very low concentrations observed at present in northwest European Shelf waters

    A quantitative estimate of English Channel water fluxes into the North Sea from 1987 to 1992 based on radiotracer distribution

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    International audienceSeven oceanographic campaigns carried out in the North Sea between July 1987 and January 1992 by the Marine Radioecology Laboratory (LRM) of La Hague have led to the drawing of general maps showing the distribution of the radionuclides 125Sb, 137Cs, 134Cs and 99Tc in seawater. In this way, the total amounts of radioactivity (inventories) present in the southern North Sea were evaluated from each separate campaign, thus leading to an assessment of the mean distribution of water masses, originating from the English Channel, which is siutated between the Straits of Dover and Skagerrak. On this basis, it is possible to link the flux of radionuclides released from the nuclear fuel reprocessing plant at La Hague (125Sb and99Tc) with the inventories of radiotracers observed in the southern North Sea. Hence, the most probable mean transit time of Channel waters entering the North Sea were calculated for each campaign; Channel waters take 110–152 days to flow from Cap de la Hague to the Straits of Dover and 170–250 days to travel from there to the entrance of the Baltic. The water flux through the Straits of Dover is estimated to lie in the range 97,000–195,000 m3/s for the period between January and July 1988. Very good agreement is found between the activities measured at different times and the results of a model simulating the hydrodynamic behaviour of the North Sea

    Decision-support tools to manage drug incompatibilities: evaluation by nurses

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    Introduction Preventing drug incompatibilities has a high impact onthe safety of drug therapy. Although there are no internationalguidelines to manage drug incompatibilities, different decision-supporttools such as handbooks, cross-tables and databases are available.In a previous study, two decision-support tools have been pre-selectedby pharmacists as fitting nurses' needs on the wards1. The objective ofthis study was to have these both tools evaluated by nurses todetermine which would be the most suitable for their daily practice.Materials & Methods Evaluated tools were:1. Cross-table of drug pairs (http://files.chuv.ch/internet-docs/pha/medicaments/pha_phatab_compatibilitessip.pdf)2. Colour-table (a colour for each drug according to the pH: red =acid; blue = basic; yellow = neutral; black = to be infused alone)2Tools were assessed by 48 nurses in 5 units (PICU, adult andgeriatric intensive care, surgery, onco-hematology) using a standardizedform1. The scientific accuracy of the tools was evaluated bydetermining the compatibility of five drugs pairs (rate of correctanswers according to the Trissel's Handbook on Injectable Drugs,chi-square test). Their ergonomics, design, reliability and applicabilitywere estimated using visual analogue scales (VAS 0-10; 0 =null, 10 = excellent). Results are expressed as the median and interquartilerange (IQR) for 25% and 75% (Wilcoxon rank sum test).Results The rate of correct answers was above 90% for both tools(cross-table 96.2% vs colour-table 92.5%, p[0.05).The ergonomics and the applicability were higher for the crosstable[7.1 (IQR25 4.0, IQR75 8.0) vs 5.0 (IQR25 2.7, IQR75 7.0), p =0.025 resp. 8.3 (IQR25 7.4, IQR75 9.2) vs 7.6 (IQR25 5.9, IQR75 8.8)p = 0.047].The design of the colour-table was judged better [4.6 (IQR25 2.9,IQR75 7.1) vs 7.1 (IQR25 5.4, IQR75 8.4) p = 0.002].No difference was observed in terms of reliability [7.3 (IQR25 6.5,IQR75 8.4) vs 6.7 (IQR25 5.0, IQR758.6) p[0.05].The cross-table was globally preferred by 65% of the nurses (27%colour-table, 8% undetermined) and 68% would like to have thisdecision-support tool available for their daily practice.Discussion & Conclusion Both tools showed the same accuracy toassess drug compatibility. In terms of ergonomics and applicabilitythe cross-table was better than the colour-table, and was preferred bythe nurses for their daily practice. The cross-table will be implementedin our hospital as decision-support tool to help nurses tomanage drug incompatibilities

    La dynamique des masses d'eaux et des matieres en suspension en Manche Orientale

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    The structuration between nearshore and offshore waters along the macrotidal French Eastern Channel coast is demonstrated by longitudinal and vertical continuous recordings of salinity, temperature, turbidity and fluorimetry. The distribution of suspended particulate matter, one dissolved marker ( super(125)Sb) and particulate markers (such as diatoms) indicates the variability of the waters from coast to open sea. Semidiurnal and semilunar tidal cycles induce the birth and the evolution of frontal structures along shore-lines with or without estuaries. The hydrodynamic consequences for suspended matter fluxes are presented
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