The NAOMI GAZL multispecies differential absorption lidar: realization and testing on the TADI gas leak simulation facility

International audienceWe report on a differential absorption lidar, designed for remote detection of CH 4 and CO 2 , based on a single-frequency 1.57-1.65 µm parametric oscillator/amplifier system. The lidar is tested on a controlled gas release facility

All-fibered coherent-differential absorption lidar at 1.645 μm for simultaneous methane and wind-speed measurements

International audienceHere we report on the development of a new coherent-DIAL system as well as first quantitative measurements of simultaneous gas mixing ratio and radial wind-speed with the instrument. Integrated measurement of atmospheric methane (CH4) mixing ratio between the instrument and a hard-target located at 2:25 km has been conducted with a relative precision of nearly 20% in 17 s. The measurement procedure also gives information on integrated water vapor (H2O) mixing ratio

Free margin length and coaptation surface area in normal tricuspid aortic valve: an anatomical study

OBJECTIVES: Aortic cusp free margins are a central target in most aortic valve repair operations to optimize valve coaptation. The objective of this anatomical study was to analyse the normal dimensions of free margin length (FML) and coaptation surface and to analyse their relationship with other valve and root dimensions in normal tricuspid aortic valves. METHODS: We analysed 25 aortic root homografts. Eight valve and root measurements were obtained from fresh specimens including the length of the free margin while applying appropriate tension on the structures. The valves were then fixed with formalin in the diastolic position under pressure to allow measurement of the coaptation surface. In addition to normal values, we analysed the correlations and ratios between the different measures. RESULTS: The mean FML was 34.3 ± 3.1 mm. The FML was similar between the 3 cusps and correlated with all other valve and root measures. The ratio of the FML to the geometric height was 1.81, and the free edge length/sinotubular junction was 1.29. The mean coaptation surface was 122 ± 21 mm2 per cusp and corresponded to 41% of the cusp surface. The central coaptation length was 3.3 ± 0.8 mm, and the lateral coaptation length was 5.9 ± 0.6 mm. The total coaptation surface per specimen was 184 ± 32 mm2. CONCLUSIONS: We described the normal dimensions of the FML and coaptation surface in the tricuspid aortic valve. These measurements will serve in the further development of an objective method of free margin shortening based on intraoperative measurements of the FML to treat cusp prolapse and low coaptation after valve-sparing surgery

Tectonic inversion along the Algerian and Ligurian margins: on the insight provided by latest seismic processing techniques applied to recent and vintage 2D offshore multichannel seismic data

International audienc

NAOMI GAZL: A Multispecies DIAL Tested on the TADI Gas Leak Simulation Facility

We report on a direct detection differential absorption lidar (DIAL), designed for remote detection of CH4 and CO2. The system is based on a single-frequency optical parametric oscillator/amplifier system, tunable in the 1.57-1.65 µm range. The DIAL system, called NAOMI GAZL, was tested on a controlled gas release facility in October 2018

NAOMI GAZL: A Multispecies DIAL Tested on the TADI Gas Leak Simulation Facility

We report on a direct detection differential absorption lidar (DIAL), designed for remote detection of CH4 and CO2. The system is based on a single-frequency optical parametric oscillator/amplifier system, tunable in the 1.57-1.65 µm range. The DIAL system, called NAOMI GAZL, was tested on a controlled gas release facility in October 2018

Remote Sensing Technologies for Detecting, Visualizing and Quantifying Gas Leaks

International audienceRemote sensing technologies can be applied for a wide range of gas leak flowrates and in three main cases: (1) major leaks in crisis management; (2) medium size leaks in safety monitoring; (3) small leaks in environmental monitoring. A gas test campaign, conducted by Total, the ONERA - the French Aerospace Lab - and ADCIS in September 2015 using three hyperspectral infrared cameras from Telops, confirmed our capacity to visualize in 3D and quantify in real time plumes of methane in the range of 1 g/s to 50g/s. The R&D project on gas remote quantification continued with a second gas test campaign in 2017. The second gas test campaign was organized on Total's Lacq Pilot Platform in France and involved several gas spectral imaging systems: (1) mobile hyperspectral cameras in the Long-Wavelength InfraRed (LWIR) band (7.7-12μm); (2) a multispectral camera in the LWIR band (7-9μm); (3) a multigas LiDAR (LIght Detection And Ranging) system coupled with a wind LiDAR system; (4) five other international teams (US, Spain, Norway and France) were also invited to assess the capacity of their remote-sensing systems to quantify methane and carbon dioxide releases. The two-week test demonstrated that methane leak emissions ranging from 0.7 g/s to 140 g/s could be visualized and quantified in real time using a mobile Telops Hyper-Cam. This campaign also served to validate the performance of several remote sensing technologies. Total's Lacq Pilot Platform is a test area for qualifying cost-effective systems designed to complement the gas detection system of a plant and provide valuable information should a gas leak incident occur. New methodologies for the early detection of anomalies using remote observation systems including drones, robots and artificial intelligence data processing systems are currently being investigated there

Inversion of back-arc basins : example of the Ligurian Basin, Western Mediterranean

The Mediterranean back-arc basins, once opened, are often rapidly submitted to inversion along the complex Eurasian-African convergent border. Along their continental margins, these small basins consist of heterogeneous systems that juxtapose lithospheres with different nature, mechanical behavior and structural inheritance. In this study, we focus on the northern Ligurian margin to examine how such complex systems might deform when they are submitted to compressive stress. The northern Ligurian margin, of Oligo-Miocene age, has been undergoing contraction over at least the last 6 Ma. Below the margin, active thrust faults responsible for the regional uplift of the continental edge have been proposed in previous works, but have never been imaged. Seaward of the margin, no recent or active crustal compressional structure has been identified so far in the oceanic domain, although seismicity extends as far as midway through the basin. We use seismic reflection data, including 72- and 12-channel high-resolution acquisitions (MALISAR, 2006 and FABLES, 2012) and 96-channel deep-penetrating ones (MALIS, 1995), to image the Ligurian margin and the adjacent oceanic domain. In the seismic lines, the Messinian event, well dated over the Mediterranean (5.96-5.32 Ma) and well identified in the seismic stratigraphy, allows us to quantify the vertical deformation over the last 5.3 Ma. The seismic reflection data set is interpreted together with 3D-velocity-depth models deduced from wide-angle seismic data (GROSMARIN, 2008). Below the margin, the contraction is characterized by folds, south verging thrusts, tilted crustal blocks, and by a global margin uplift that exceeds 1500m. Within the adjacent oceanic domain, noticeable deformation is restricted to large, SW-NE elongated salt walls located 10 to 40 km from the margin toe, over a 70 km length. We interpret them as resulting from combined deep-seated crustal and thin-skinned deformations. However, although the salt walls are well expressed in the seafloor morphology, their seismic images do not reveal any significant vertical throw across their trace, and the amount of deformation gradually disappears toward the structure ends. This suggests that the post-Messinian deformation taken along these features is moderate, compared to the margin. The synchronicity of the crustal deformation in the oceanic and the continental domains supports the idea that the lower deformation amounts observed within the deep basin are related to different mechanical behaviours within the continental margin and the adjacent oceanic domain, rather than the result of a recent basinward propagation of the deformation. Thermo-mechanical models suggest that mainly two factors could control the focused deformation along the margin: (1) the locus of highest topographic gradient of the main crustal interfaces, (2) the thermal contrast between the subsiding cooling oceanic domain and the uplifting warming margin. According to these models, the continental versus oceanic nature of the lithospheres would be of second order in the localization of the deformation

Development of a prediction model for postoperative pneumonia A multicentre prospective observational study

BACKGROUND Postoperative pneumonia is associated with increased morbidity, mortality and costs. Prediction models of pneumonia that are currently available are based on retrospectively collected data and administrative coding systems. OBJECTIVE To identify independent variables associated with the occurrence of postoperative pneumonia. DESIGN A prospective observational study of a multicentre cohort (Prospective Evaluation of a RIsk Score for postoperative pulmonary COmPlications in Europe database). SETTING Sixty-three hospitals in Europe. PATIENTS Patients undergoing surgery under general and/or regional anaesthesia during a 7-day recruitment period. MAIN OUTCOME MEASURE The primary outcome was postoperative pneumonia. Definition: the need for treatment with antibiotics for a respiratory infection and at least one of the following criteria: new or changed sputum; new or changed lung opacities on a clinically indicated chest radiograph; temperature more than 38.3 degrees C; leucocyte count more than 12 000 mu l(-1). RESULTS Postoperative pneumonia occurred in 120 out of 5094 patients (2.4%). Eighty-two of the 120 (68.3%) patients with pneumonia required ICU admission, compared with 399 of the 4974 (8.0%) without pneumonia (P < 0.001). We identified five variables independently associated with postoperative pneumonia: functional status [odds ratio (OR) 2.28, 95% confidence interval (CI) 1.58 to 3.12], pre-operative SpO(2) values while breathing room air (OR 0.83, 95% CI 0.78 to 0.84), intra-operative colloid administration (OR 2.97, 95% CI 1.94 to 3.99), intra-operative blood transfusion (OR 2.19, 95% CI 1.41 to 4.71) and surgical site (open upper abdominal surgery OR 3.98, 95% CI 2.19 to 7.59). The model had good discrimination (c-statistic 0.89) and calibration (Hosmer-Lemeshow P = 0.572). CONCLUSION We identified five variables independently associated with postoperative pneumonia. The model performed well and after external validation may be used for risk stratification and management of patients at risk of postoperative pneumonia