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Davies, Peter; Reaud, Yvan; Dussud, Loic; Woerther, Patrice. |
This paper describes the mechanical behaviour of ropes used for deep sea oceanographic operations. First the requirements of deep sea handling ropes are presented. Two high performance fibres are commonly used, aramid co-polymer and high modulus polyethylene (HMPE), and these are then compared. Results from tests on single fibres and 50 ton break load braided ropes are presented, which show that the initial stiffness of a new HMPE rope increases with load level in a bedding-in process resulting from both molecular alignment and construction reorientation. The aramid rope is less sensitive to this effect and shows a high stiffness from first loading. Measurements made at sea on oceanographic ropes of both materials using an elastic recoil method are... |
Tipo: Text |
Palavras-chave: Fibre rope; Deep sea coring; Stiffness; Aramid; HMPE. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00054/16573/14068.pdf |
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Bourillet, Jean-francois; Damy, Gilbert; Dussud, Loic; Sultan, Nabil; Woerther, Patrice; Migeon, Sebastien. |
Various observations pointed out that cores performed with gravity piston corer show signifi cant distortions mainly located at the top of the core. A series of 15 cores were performed at the same location on a submarine sand wave (Var canyon, France). Six different settings of the corer – three freefall heights and three slacks of the piston cable – were tested, including duplicates. Two accelerometers recorded simultaneously the movements of the core tube and the movements of the triggering arm. Then the z displacements were obtained by a double integration versus time of the measured acceleration. The analyses of results allowed the authors to estimate the amplitude and the duration of the elastic recoil of the aramid cable, andto distinguish four steps... |
Tipo: Text |
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Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/00071/18198/15766.pdf |
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Leblond, Emilie; Lazure, Pascal; Laurans, Martial; Rioual, Celine; Woerther, Patrice; Quemener, Loic; Berthou, Patrick. |
Face to the lack of data to assess precisely the spatial distribution of catches and fishing effort and for the environmental characterization of the fishing area, Ifremer has been implemented since 2005 a new project, Recopesca. It consists in fitting out a sample of voluntary fishing vessels with sensors recording data on fishing effort (and at mid-terms catches) and physical parameters such as temperature or salinity. Recopesca aims at setting up a network of sensors, for scientific purposes, to collect data and improve resources assessment and diagnostics on fisheries, and environmental data required for ecosystem-based management initiatives. The challenge was to develop sensors with no trouble for the fishermen, tough enough to be fixed up on fishing... |
Tipo: Text |
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Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00024/13500/10514.pdf |
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Etcheber, H.; Schmidt, S.; Sottolichio, Aldo; Maneux, E.; Chabaux, G.; Escalier, J. -m.; Wennekes, H.; Derriennic, H.; Schmeltz, M.; Quemener, Loic; Repecaud, Michel; Woerther, Patrice; Castaing, P.. |
The Gironde Estuary, one of the largest European ones, presents temporary low dissolved oxygen content in its fluvial section close to the Bordeaux urban area. In a context of population growth and of long-term environmental changes, the development of a high-frequency monitoring programme of the fluvial-estuarine system of the Gironde, called MAGEST (MArel Gironde ESTuary), had appeared essential to address current and future water-quality issues/evaluations. The objectives of the MAGEST survey program are to establish a reference database to improve the knowledge of the Gironde Estuary functioning, encompassing the aspects of hydrology, sediment dynamics and biogeochemistry. Through examples of results from intratidal to seasonal time scales, we... |
Tipo: Text |
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Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00033/14466/11766.pdf |
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Samain, Jean-francois; Ropert, Michel; Bedier, Edouard; Soletchnik, Patrick; Mazurie, Joseph; Le Coz, Florence; Blin, Jean-louis; Mille, Dominique; Pajot, Régis; Haffray, Patrick; Bacher, Cedric; Grangere, Karine; Grangere, Karine; Pouvreau, Stephane; Bourles, Yves; Gohin, Francis; Woerther, Patrice; Boudry, Pierre. |
Summer mortality has been reported in the Pacific oyster, Crassostrea gigas, for many years in Japan, US and Europe. It affects both adults and juveniles and the causes of this phenomenon are complex. Environmental, physiological or pathological putative causes were studied all over the world. Recently, the MOREST project ((MORtalitEStivale) a multidisciplinary project (2001-2005) focused on his problem led to a better understanding of this phenomenon in France. The results showed in these geographical conditions, the main interactions between the oysters, their environment and certain pathogens. |
Tipo: Text |
Palavras-chave: Interaction model; Environmental parameters; Summer mortality; Crassostrea gigas; Pacific oyster. |
Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/2006/acte-3476.pdf |
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Leblond, Emilie; Berthou, Patrick; Laurans, Martial; Woerther, Patrice; Quemener, Loic. |
Face to the lack of data to assess precisely the spatial distribution of catches and fishing effort and for the environmental characterization of the fishing area, Ifremer has been implemented since 2005 a new project, Recopesca. It consists in fitting out a sample of voluntary fishing vessels with sensors recording data on fishing effort (and at mid-terms catches) and physical parameters such as temperature or salinity. Recopesca aims at setting up a network of sensors, for scientific purposes, to collect data allowing improving resources assessment and diagnostics on fisheries, and environmental data required for ecosystem-based management initiatives. The challenge was to develop sensors with no trouble for the fishermen, tough enough to be fixed up on... |
Tipo: Text |
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Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/00059/17000/14501.pdf |
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