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| Registros recuperados: 14 | |
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| Ikhennicheu, Maria; Gaurier, Benoit; Druault, Philippe; Germain, Gregory. |
| The present study aims at investigating turbulence characteristics in high flow velocity areas like those suitable for marine energy application. The Reynolds number, based on the rugosity height and mean flow velocity, is rather high: . For that purpose, experiments are carried out in a flume tank with as high as achievable in Froude similitude (in the tank: and ). Obstacles are canonical wall-mounted elements chosen to be representative of averaged bathymetric variations: a cube and a cube followed by an inclined floor. First, the wake topology past a canonical wall-mounted cube is illustrated from PIV measurements. Results show a flow behaviour already observed in the literature but for different upstream conditions ( and turbulence intensity). Second,... |
| Tipo: Text |
Palavras-chave: Turbulence; Experimental trials; Wall-mounted obstacles; PIV; POD; Quadrant method. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00449/56050/57570.pdf |
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| Bouhoubeiny, Elkhadim; Druault, Philippe; Germain, Gregory. |
| Time-Resolved Particle Image Velocimetry (PIV) measurements are performed to investigate the hydrodynamic flow interaction with a representative piece of fishing net structure. Using the advanced post-processing mathematical tool based on Proper Orthogonal Decomposition, the phase averaged mean properties of turbulent flows are extracted from PIV database, demonstrating the existence of a Turbulent Boundary Layer (TBL) flow developing all around the sheet of net. The results also show that the mesh opening and so the turbulent flow passing through the structure are strongly influenced by the structure oscillations. This work allows us to demonstrate that the drag computation of fishing gear, commonly based on uniform velocity, needs to consider not only... |
| Tipo: Text |
Palavras-chave: Fishing net structure; Hydrodynamics; PIV; Turbulent boundary layer flow. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00184/29552/27878.pdf |
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| Gaurier, Benoit; Druault, Ph.; Ikhennicheu, Maria; Germain, Gregory. |
| In the main tidal energy sites like Alderney Race, turbulence intensity is high and velocity fluctuations may have a significant impact on marine turbines. To understand such phenomena better, a three-bladed turbine model is positioned in the wake of a generic wall-mounted obstacle, representative of in situ bathymetric variation. From two-dimensional Particle Image Velocimetry planes, the time-averaged velocity in the wake of the obstacle is reconstructed in the three-dimensional space. The reconstruction method is based on Proper Orthogonal Decomposition and enables access to a representation of the mean flow field and the associated shear. Then, the effect of the velocity gradient is observed on the turbine blade root force, for four turbine locations... |
| Tipo: Text |
Palavras-chave: Tidal turbine; Blade force; Turbulent wake; Experimental trials; PIV; POD. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75535/76540.pdf |
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| Ikhennicheu, Maria; Germain, Gregory; Druault, Philippe; Gaurier, Benoit. |
| In high flow velocity areas like those suitable for marine energy application, bathymetry variations create strong velocity fluctuations in the water column. It is therefore essential to characterize the turbulence evolution in the wake of seabed elements which may impact the loads on tidal turbines. For that purpose, experiments are carried out in a flume tank with Re as high as achievable in Froude similitude, with bathymetry variations experimentally represented with various wall-mounted square elements of height H: a cylinder or a cube as unitary obstacles and combinations of these elements followed by an inclined floor to resemble smooth bathymetry changes. The onset flow is a simple boundary layer profile with height 1.3 H and a low turbulence... |
| Tipo: Text |
Palavras-chave: Turbulence; Experimental trials; Wall-mounted obstacles; PIV; LDV; Marine energy. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00502/61356/64997.pdf |
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| Ikhennicheu, Maria; Germain, Gregory; Druault, Philippe; Gaurier, Benoit. |
| In high flow velocity areas like those suitable for tidal applications, turbulence intensity is high and flow variations may have a major impact on tidal turbines behaviour. Large boils that can be observed at the sea surface are emitted from the sea floor and may interact with the tidal turbines. These boils have then to be characterized. The Reynolds number, based on the rugosity height and the mean flow velocity, is rather high in this context: Re ¼ 2:5 107. For that purpose, experiments are carried out in a flume tank with Re as high as achievable in Froude similitude (in the tank: Re ¼ 2:5 105 and Fr ¼ 0:23) in order to study coherent flow structures emitted behind seabed obstacles. The obstacle is here a canonical square wall-mounted cylinder chosen... |
| Tipo: Text |
Palavras-chave: Turbulence; Experimental trials; Wall-mounted cylinder; PIV; LDV; POD; Lamb-Oseen. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00494/60527/64189.pdf |
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| Araújo,M.C.C.; Vale Filho,V.R.; Ferreira,A.M.; Sá,W.F.; Barreto Filho,J.B.; Camargo,L.S.A.; Serapião,R.V.; Silva,M.V.G.B.. |
| The effect of cryopreservation in IFN-tau, from bovine embryos produced in vitro was evaluated. Two treated groups (G1= fresh bovine embryos, n=59 and G2= freezed embryos, n=84) were used to study the effect of cryopreservation on IFN-tau secretion. After reaching the blastocyst phase, the embryos were kept on individual culture for additional period of 7 days. On days 3 and 7 after the beginning of embryos cultivation, samples of the media culture were taken for IFN-tau secretion titration. Oocysts taken from follicles ranging from 3 to 5mm in diameter were obtained from ovaries of females at slaughterhouse. The embryos were frozen, after being dehydrated with ethylene glycol (1.8m), conditioned on 0.5ml palletes and frozen. Frozen embryos secreted lower... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bovine; Embryo; PIV; Interferon-tau. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352005000600008 |
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| Leivas,Fábio Gallas; Brum,Daniela dos Santos; Mezzalira,Alceu; Pilla,Luis Fernando Cáceres; Bernardi,Mari Lourdes; Rubin,Mara Iolanda Batistella; Silva,Carlos Antonio Mondino. |
| Oócitos (n=1177) bovinos obtidos da aspiração de folículos com diâmetro entre 2 e 8mm, de ovários de matadouro foram divididos aleatoriamente em quatro tratamentos com 11 repetições. Os oócitos foram maturados por 24h em TCM-199 Sais de Earle, acrescido de 25mM de bicarbonato de sódio, 25mM de HEPES, rFHS-h, Soro de Vaca em Estro (SVE) e piruvato, em estufa a 39ºC, com 5% de CO2 em ar e umidade saturada (Grupo Controle, n=296) ou, submetidos ao transporte simulado por 6 (T6, n=286), 12 (T12, n=294) ou 18h (T18, n=301) em meio de maturação TCM+HEPES, em banho-maria a 39ºC, com os mesmos componentes utilizados para o Grupo Controle, porém com apenas 1mM de bicarbonato. Decorrido cada período de transporte, os mesmos foram transferidos para placas com meio de... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Oócitos bovinos; Hepes; OPU; PIV; Transporte. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782004000100034 |
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| Registros recuperados: 14 | |
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