20 research outputs found

    Inviscid approach for upwind sails aerodynamics. How far can we go?

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    This work presents a full-scale experimental study of a yacht rig and sails in real upwind sailing conditions and a comparison with Fluid Structure Interaction (FSI) simulations with the ARAVANTI model (Finite Element Method for the structure and Vortex Lattice Method for the fluid). An specific on-board instrumentation system simultaneously measures loads in the rig and sails, sailing data (wind, boat attitude and speed) and the shape of sails in real navigation conditions (flying shape). Flying shape parameters are extracted using the camera-based VSPARS system to characterize the effects of sail trims and to be compared with the results of the simulation. The potential flow solver gives fast and accurate predictions of both the flying shape and the loads in the rig in most conditions. The inviscid approach, commonly used in the early stage of design, must be checked, as in particular cases where the sails are heavily loaded, flow separation is significant and results from a potential flow solver are inaccurate. A new version of the model including the heel angle as an additional degree of freedom in the structural solver enables to detect when the inviscid flow approach overestimates the aerodynamic load. This upgrade improves the utility and reliability of the inviscid flow approach which remains relevant at the early stages of design as it is much more cost-effective than RANS models.Brest MĂ©tropole OcĂ©ane, RĂ©gion Bretagne and the European Union’s Seventh Framework Programme (FP7/2007-2013) under REA grant agreement PCOFUND-GA-2013-609102 (PRESTIGE-Campus France

    Recent developments of marine ingredients for food and nutraceutical applications: a review.

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    Remerciements Ă  l'Ă©diteur pour son accord de diffusion. L'article original est aussi accessible sur le site de l'Ă©diteur Ă  l'adresse : http://www.halieutique.org/23201b.htmlInternational audienceIn a global context of marine biological resource overexploitation, a better upgrading of fish and shellfish biomass is a challenge for the 21st century. One of the main and promising issues will be the production of marine bio-ingredients using enzymatic hydrolysis. This paper presents the key steps in the production of enzymatic hydrolysates, such as (i) enzymatic treatment for the bioconversion of solid discards, and more particularly, use of proteases, (ii) quantification of the proteolysis extend and procedures of quality-control and (iii) identification of biological activity, using in vitro and in vivo methods. In the last part, examples of marine, commercially available functional foods or nutraceutical ingredients carrying bioactive properties are presented in order to demonstrate the interest of biotechnological exploitation of marine resources

    Empiric antimicrobial therapy for ventilator-associated pneumonia after brain injury

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    International audienceIssues regarding recommendations on empiric antimicrobial therapy for ventilator-associated pneumonia (VAP) have emerged in specific populations.To develop and validate a score to guide empiric therapy in brain-injured patients with VAP, we prospectively followed a cohort of 379 brain-injured patients in five intensive care units. The score was externally validated in an independent cohort of 252 brain-injured patients and its extrapolation was tested in 221 burn patients.The multivariate analysis for predicting resistance (incidence 16.4%) showed two independent factors: preceding antimicrobial therapy ≄48 h (p\textless0.001) and VAP onset ≄10 days (p\textless0.001); the area under the receiver operating characteristic curve (AUC) was 0.822 (95% CI 0.770-0.883) in the learning cohort and 0.805 (95% CI 0.732-0.877) in the validation cohort. The score built from the factors selected in multivariate analysis predicted resistance with a sensitivity of 83%, a specificity of 71%, a positive predictive value of 37% and a negative predictive value of 96% in the validation cohort. The AUC of the multivariate analysis was poor in burn patients (0.671, 95% CI 0.596-0.751).Limited-spectrum empirical antimicrobial therapy has low risk of failure in brain-injured patients presenting with VAP before day 10 and when prior antimicrobial therapy lasts \textless48 

    ContrÎles microbiologiques des endoscopes au centre hospitalier régional de Brest du 1er janvier 2007 au 31 décembre 2009. [Microbiological investigation of endoscopes at Brest Hospital over a period from 2007 to 2009].

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    International audienceOBJECTIVES: The aim of this study is to evaluate the quality of disinfection of endoscopes at Brest hospital over a period from 2007 to 2009. PATIENTS AND METHODS: Retrospective study of microbiological investigations of endoscopes done at Brest hospital from 2007 to 2009. The interpretation of the microbiological investigations is based on the recommendations of the Comité technique national des infections nosocomiales et infections liées aux soins (CTINILS) of 2007. RESULTS: Most of the controls realized over the period deal with gastroenterological endoscopes (63.4 %) and bronchial endoscopes (21.8 %). Most of the controls (66.8 %) are conformed to the target level. Only 26.7 % of the controls get the level of action. Globally, the rate of level of action significantly increases (p=0.004) from 2007 (21.2 %) to 2009 (35.6 %). This increase is relatively important in gastroenterology endoscopy (46.8 % in 2009 versus 24.1 % in 2007) whereas the rate decreases in bronchial endoscopy (14.8 % in 2009 versus 25.9 % in 2007). In gastroenterological endoscopy, rates vary with the type of endoscopes and the context of controls, but there is no significant difference between manual disinfection and automated disinfection. The most frequent germ found in gastroenterological and bronchial endoscopies is Pseudomonas aeruginosa. CONCLUSION: Our results show that it is very difficult to insure a perfect disinfection of endoscopes. Difficulties met are certainly related with the complexity of the endoscopes and of the techniques of disinfection. Infections of patients are very infrequent in endoscopy, which takes the question of the pertinence of the threshold used for microbiological investigations

    In-situ Identification of Spilled Oils Using Mass Spectrometry

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    International audienceTwo mass spectrometers (PTR-MS and Portable Electron Impact) have been used to characterize oil samples both in the laboratory and in the field. These instruments offer the possibility of real-time analysis of fresh samples and so can be used for a rough classification of the oil studied. © Proceedings - 45th AMOP Technical Seminar on Environmental Contamination and Response

    In-situ Identification of Spilled Oils Using Mass Spectrometry

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    International audienceTwo mass spectrometers (PTR-MS and Portable Electron Impact) have been used to characterize oil samples both in the laboratory and in the field. These instruments offer the possibility of real-time analysis of fresh samples and so can be used for a rough classification of the oil studied. © Proceedings - 45th AMOP Technical Seminar on Environmental Contamination and Response

    Clinical application of a population-based input function (PBIF) for a shortened dynamic whole-body FDG-PET/CT protocol in patients with metastatic melanoma treated by immunotherapy

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    Abstract Background The aim was to investigate the feasibility of a shortened dynamic whole-body (dWB) FDG-PET/CT protocol and Patlak imaging using a population-based input function (PBIF), instead of an image-derived input function (IDIF) across the 60-min post-injection period, and study its effect on the FDG influx rate (Ki) quantification in patients with metastatic melanoma (MM) undergoing immunotherapy. Methods Thirty-seven patients were enrolled, including a PBIF modeling group (n = 17) and an independent validation cohort (n = 20) of MM from the ongoing prospective IMMUNOPET2 trial. All dWB-PET data were acquired on Vision 600 PET/CT systems. The PBIF was fitted using a Feng’s 4-compartments model and scaled to the individual IDIF tail’s section within the shortened acquisition time. The area under the curve (AUC) of PBIFs was compared to respective IDIFs AUC within 9 shortened time windows (TW) in terms of linear correlation (R 2) and Bland–Altman tests. Ki metrics calculated with PBIF vs IDIF on 8 organs with physiological tracer uptake, 44 tumoral lesions of MM and 11 immune-induced inflammatory sites of pseudo-progression disease were also compared (Mann–Whitney test). Results The mean ± SD relative AUC bias was calculated at 0.5 ± 3.8% (R 2 = 0.961, AUCPBIF = 1.007 × AUCIDIF). In terms of optimal use in routine practice and statistical results, the 5th–7th pass (R 2 = 0.999 for both Ki mean and Ki max) and 5th–8th pass (mean ± SD bias = − 4.9 ± 6.5% for Ki mean and − 4.8% ± 5.6% for Ki max) windows were selected. There was no significant difference in Ki values from PBIF5_7 vs IDIF5_7 for physiological uptakes (p > 0.05) as well as for tumor lesions (mean ± SD Ki IDIF5_7 3.07 ± 3.27 vs Ki PBIF5_7 2.86 ± 2.96 100ml/ml/min, p = 0.586) and for inflammatory sites (mean ± SD Ki IDIF5_7 1.13 ± 0.59 vs Ki PBIF5_7 1.13 ± 0.55 100ml/ml/min, p = 0.98). Conclusion Our study showed the feasibility of a shortened dWB-PET imaging protocol with a PBIF approach, allowing to reduce acquisition duration from 70 to 20 min with reasonable bias. These findings open perspectives for its clinical use in routine practice such as treatment response assessment in oncology

    Recent developments of marine ingredients for food and nutraceutical applications: a review.

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    Remerciements Ă  l'Ă©diteur pour son accord de diffusion. L'article original est aussi accessible sur le site de l'Ă©diteur Ă  l'adresse : http://www.halieutique.org/23201b.htmlInternational audienceIn a global context of marine biological resource overexploitation, a better upgrading of fish and shellfish biomass is a challenge for the 21st century. One of the main and promising issues will be the production of marine bio-ingredients using enzymatic hydrolysis. This paper presents the key steps in the production of enzymatic hydrolysates, such as (i) enzymatic treatment for the bioconversion of solid discards, and more particularly, use of proteases, (ii) quantification of the proteolysis extend and procedures of quality-control and (iii) identification of biological activity, using in vitro and in vivo methods. In the last part, examples of marine, commercially available functional foods or nutraceutical ingredients carrying bioactive properties are presented in order to demonstrate the interest of biotechnological exploitation of marine resources
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