Correlating low energy impact damage with changes in modal parameters: a preliminary study on composite beams

This paper is an experimental study of the effects of multi-site damage on the vibration response of a composite beam damaged by low energy impact. The variation of the modal parameters with different levels of impact energy and density of impact is studied. Specimens are impacted symmetrically in order to induce a global rate of damage. A damage detection tool Damage Index is introduced in order to verify the estimation of damping ratios. Design of Experiments is used to establish the sensitivity of both energy of impact and density of damage. The DOE analysis results (using natural frequency only) indicate that impact energy for 2nd, 3rd and 4th bending modes is the most significant factor contributing to the changes in the modal parameters for this kind of symmetrical dynamic test

Comparison of total column ozone obtained by the IASI-MetOp satellite with ground-based and OMI satellite observations in the southern tropics and subtropics

International audienceThis paper presents comparison results of the total column ozone (TCO) data product over 13 southern tropical and subtropical sites recorded from the Infrared Atmospheric Sounder Interferometer (IASI) onboard the EU-METSAT (European organization for the exploitation of METeorological SATellite) MetOp (Meteorological Operational satellite program) satellite. TCO monthly averages obtained from IASI between June 2008 and December 2012 are compared with collocated TCO measurements from the Ozone Monitoring Instrument (OMI) on the OMI/Aura satellite and the Dobson and SAOZ (Système d'Analyse par Observation Zénithale) ground-based instruments. The results show that IASI displays a positive bias with an average less than 2 % with respect to OMI and Dobson observations, but exhibits a negative bias compared to SAOZ over Bauru with a bias around 2.63 %. There is a good agreement between IASI and the other instruments, especially from 15 • S southward where a correlation coefficient higher than 0.87 is found. IASI exhibits a seasonal dependence, with an upward trend in autumn and a downward trend during spring, especially before September 2010. After September 2010, the autumn seasonal bias is considerably reduced due to changes made to the retrieval algorithm of the IASI level 2 (L2) product. The L2 product released after August (L2 O 3 version 5 (v5)) matches TCO from the other instruments better compared to version 4 (v4), which was released between June 2008 and August 2010. IASI bias error recorded from September 2010 is estimated to be at 1.5 % with respect to OMI and less than ±1 % with respect to the other ground-based instruments. Thus, the improvement made by O 3 L2 version 5 (v5) product compared with version 4 (v4), allows IASI TCO products to be used with confidence to study the distribution and interannual variability of total ozone in the southern tropics and subtropics. Keywords. Atmospheric composition and structure (middle atmosphere – composition and chemistry

A linear CO chemistry parameterization in a chemistry-transport model: evaluation and application to data assimilation

This paper presents an evaluation of a new linear parameterization valid for the troposphere and the stratosphere, based on a first order approximation of the carbon monoxide (CO) continuity equation. This linear scheme (hereinafter noted LINCO) has been implemented in the 3-D Chemical Transport Model (CTM) MOCAGE (MOdèle de Chimie Atmospherique Grande Echelle). First, a one and a half years of LINCO simulation has been compared to output obtained from a detailed chemical scheme output. The mean differences between both schemes are about ±25 ppbv (part per billion by volume) or 15% in the troposphere and ±10 ppbv or 100% in the stratosphere. Second, LINCO has been compared to diverse observations from satellite instruments covering the troposphere (Measurements Of Pollution In The Troposphere: MOPITT) and the stratosphere (Microwave Limb Sounder: MLS) and also from aircraft (Measurements of ozone and water vapour by Airbus in-service aircraft: MOZAIC programme) mostly flying in the upper troposphere and lower stratosphere (UTLS). In the troposphere, the LINCO seasonal variations as well as the vertical and horizontal distributions are quite close to MOPITT CO observations. However, a bias of ~−40 ppbv is observed at 700 Pa between LINCO and MOPITT. In the stratosphere, MLS and LINCO present similar large-scale patterns, except over the poles where the CO concentration is underestimated by the model. In the UTLS, LINCO presents small biases less than 2% compared to independent MOZAIC profiles. Third, we assimilated MOPITT CO using a variational 3D-FGAT (First Guess at Appropriate Time) method in conjunction with MOCAGE for a long run of one and a half years. The data assimilation greatly improves the vertical CO distribution in the troposphere from 700 to 350 hPa compared to independent MOZAIC profiles. At 146 hPa, the assimilated CO distribution is also improved compared to MLS observations by reducing the bias up to a factor of 2 in the tropics. This study confirms that the linear scheme is able to simulate reasonably well the CO distribution in the troposphere and in the lower stratosphere. Therefore, the low computing cost of the linear scheme opens new perspectives to make free runs and CO data assimilation runs at high resolution and over periods of several years

CONDUITE A TENIR DEVANT UN CORPS ETRANGER DU GLOBE OCULAIRE

Les corps étrangers (C.E.) du globe oculaire sont fréquents en traumatologie oculaire (18%) et peuvent être responsables de complications graves qui aboutissent parfois à la perte anatomique et /ou fonctionnelle de l’œil. Ils doivent toujours être recherchés devant un œil rouge ou un œil traumatique (plaie, brûlure oculaire ...etc.). C’est une urgence diagnostique et thérapeutique et le praticien doit toujours mener son examen avec l’arrière pensée de l’existence d’un corps étranger intraoculaire devant un traumatisé oculaire. Avant d’adresser le patient vers un ophtalmologiste, l’omnipraticien peut déjà à ce stade évaluer la gravité de la lésion et son degré d’urgence et commencer même certaines attitudes thérapeutiques qui peuvent jouer un rôle primordial dans le pronostic fonctionnel du patient si elles sont prises précocement. Lors de l’examen un éclairage direct et un système grossissant (loupes, lunettes, ophtalmoscope direct…) sont indispensables pour le diagnostic. Ces corps étrangers peuvent être subdivisés en corps étrangers superficiels et corps étrangers intra-oculaires

APPORT DE L’IMAGERIE DANS L’ABDOMEN AIGU NON FEBRILE

The non febrile abdominal pains are very frequent and their causes are multiple. The imaging is important in the diagnosis, the complete physical examination, the follow-up and the treatment of the abdominopelvic lesions. The abdominal negatives without preparation are still used for the search of intestinal occlusion, acute intestinal ischemia. The echography is indicated particularly in the abdominal traumatisms, pelvic pain in the woman and for the search of lithiasis in the case of biliary ileus. The echo-doppler is indicated mainly in the vascular pathology. The computerized tomography is still the preferable examination in the diagnosis of the non febrile acute abdomens. The angiography is necessary if there is suspicion of mesenteric ischemia, digestive hemorrhage and particularly in an interventional gesture.Les douleurs abdominales aiguës non fébriles sont très fréquentes et relèvent de causes multiples. L’imagerie prend une place importante dans le diagnostic, le bilan, le suivi et le traitement des lésions abdomino-pelviennes. Les clichés d’abdomen sans préparation gardent leur indication à la recherche d’une occlusion intestinale, d’une ischémie intestinale aiguë. L’échographie est indiquée surtout dans les traumatismes abdominaux, douleurs pelviennes chez la femme et  à la recherche de lithiase en cas d’iléus biliaire. L’écho-doppler est indiquée principalement dans la pathologie vasculaire. La TDM reste l’examen de choix dans le diagnostic des abdomens aigus non fébriles. L’angiographie est justifiée en cas de suspicion d’une ischémie mésentérique, d’une hémorragie digestive et surtout dans un geste interventionnel

Analysis of a rapid increase of stratospheric ozone during late austral summer 2008 over Kerguelen (49.4° S, 70.3° E)

This paper reports on an increase of ozone event observed over Kerguelen (49.4° S, 70.3° E) in relationship with large-scale isentropic transport. This is evidenced by ground-based observations (co-localised radiosonde and SAOZ experiments) together with satellite global observations (Aura/MLS) assimilated into MOCAGE, a Méteo-France model. <br><br> The study is based on the analyses of the first ozonesonde experiment never recorded at the Kerguelen site within the framework of a French campaign called ROCK that took place from April to August 2008. <br><br> Comparisons and interpretations of the observed event are supported by co-localised SAOZ observations, by global mapping of tracers (O<sub>3</sub>, N<sub>2</sub>O and columns of O<sub>3</sub>) from Aura/MLS and Aura/OMI experiments, and by model simulations of Ertel Potential Vorticity initialised by the ECMWF (European Centre for Medium-Range Weather Forecasts) data reanalyses. <br><br> Satellite and ground-based observational data revealed a consistent increase of ozone in the local stratosphere by mid-April 2008. Additionally, Ozone (O<sub>3</sub>) and nitrous oxide (N<sub>2</sub>O) profiles obtained during January–May 2008 using the Microwave Limb Sounder (MLS) aboard the Aura satellite are assimilated into MOCAGE (MOdèle de Chimie Atmosphérique à Grande Echelle), a global three-dimensional chemistry transport model of Météo-France. The assimilated total O<sub>3</sub> values are consistent with SAOZ ground observations (within ±5%), and isentropic distributions of O<sub>3</sub> match well with maps of advected potential vorticity (APV) derived from the MIMOSA model, a high-resolution advection transport model, and from the ECMWF reanalysis. <br><br> The event studied seems to be related to the isentropic transport of air masses that took place simultaneously in the lower- and middle-stratosphere, respectively from the polar region and from the tropics to the mid-latitudes. <br><br> In fact, the ozone increase observed by mid April 2008 resulted simultaneously: (1) from an equator-ward departure of polar air masses characterised with a high-ozone layer in the lower stratosphere (near the 475 K isentropic level), and (2) from a reverse isentropic transport from the tropics to mid- and high-latitudes in the upper stratosphere (nearby the 700 K level). The increase of ozone observed over Kerguelen from the 16-April ozonesonde profile is thus attributed to a concomitant isentropic transport of ozone in two stratospheric layers: the tropical air moving southward and reaching over Kerguelen in the upper stratosphere, and the polar air passing over the same area but in the lower stratosphere

Midlatitude stratosphere - troposphere exchange as diagnosed by MLS O3 and MOPITT CO assimilated fields

International audienceThis paper presents a comprehensive characterization of a very deep stratospheric intrusion which occurred over the British Isles on 15 August 2007. The signature of this event is diagnosed using ozonesonde measurements over Lerwick, UK (60.14 N, 1.19 W) and is also well characterized using meteorological analyses from the global operational weather prediction model of Météo-France, ARPEGE. Modelled as well as assimilated fields of both ozone (O3) and carbon monoxide (CO) have been used in order to better document this event. O3 and CO from Aura/MLS and Terra/MOPITT instruments, respectively, are assimilated into the three-dimensional chemical transport model MOCAGE of Météo-France using a variational 3-DFGAT (First Guess at Appropriate Time) method. The validation of O3 and CO assimilated fields is done using selfconsistency diagnostics and by comparison with independent observations such as MOZAIC (O3 and CO), AIRS (CO) and OMI (O3). It particularly shows in the upper troposphere and lower stratosphere region that the assimilated fields are closer to MOZAIC than the free model run. The O3 bias between MOZAIC and the analyses is −11.5 ppbv with a RMS of 22.4 ppbv and a correlation coefficient of 0.93, whereas between MOZAIC and the free model run, the corresponding values are 33 ppbv, 38.5 ppbv and 0.83, respectively. In the same way, for CO, the bias, RMS and correlation coefficient between MOZAIC and the analyses are −3.16 ppbv, 13 ppbv and 0.79, respectively, whereas between MOZAIC and the free model run, the corresponding values are 33 ppbv, 38.5 ppbv and 0.83, respectively. In the same way, for CO, the bias, RMS and correlation coefficient between MOZAIC and the analyses are −3.16 ppbv, 13 ppbv and 0.79, respectively, whereas between MOZAIC and the free model they are 6.3 ppbv, 16.6 ppbv and 0.71, respectively. The paper also presents a demonstration of the capability of O3 and CO assimilated fields to better describe a stratosphere-troposphere exchange (STE) event in comparison with the free run modelled O3 and CO fields. Although the assimilation of MLS data improves the distribution of O3 above the tropopause compared to the free model run, it is not sufficient to reproduce the STE event well. Assimilated MOPITT CO allows a better qualitative description of the stratospheric intrusion event. The MOPITT CO analyses appear more promising than the MLS O3 analyses in terms of their ability to capture a deep STE event. Therefore, the results of this study open the perspectives for using MOPITT CO in the STE studies

TUBERCULOSE OCULAIRE

Ocular manifestations in tuberculosis are rare, they are observed only in 1 to 2% of cases. With the advent of AIDS, ocular affections in tuberculosis have been encountered with increased frequency. We report a serie of six cases of ocular tuberculosis admitted in our Ophthalmology department between 2004 and 2006. Among the six cases of tuberculosis eye, there is a notion of tuberculosis contagion in one case, extra ocular tuberculosis in three cases. A palpebral nodule is found in one case; follicular conjunctivitis in one case; interstitial keratitis in one case, an uveitis in three cases. The diagnosis is based on the clinical, para-clinical arguments. Chemotherapy was instituted in all patients with treatment-steroidal anti-inflammatory in three cases. Evolution was favourable in five cases. Ocular tuberculosis is an affection less often than before. A resurgence in recent years due to the spread of AIDS and multi-resistant forms. is noted Uveal involving is the most common ocular presentation. The diagnosis is based on a clinical, biological, para-clinical and histological arguments Tuberculosis treatment is principally related to preventive measures. The authors report ocular tuberculosis diagnostic problems on the necessity of regular ophthalmic examination of patients under treatment.Les manifestations oculaires au cours de la tuberculose sont rares, puisqu’elles ne sont observées que dans 1 à 2% des cas. Cette atteinte oculaire connaît actuellement une recrudescence avec l’avènement du SIDA. Nous rapportons une série de six cas de tuberculose oculaire colligée dans notre service d’Ophtalmologie Adulte entre 2004 et 2006. Sur les six cas de tuberculose oculaire, on retrouve une notion de contage tuberculeux dans un cas, une tuberculose extra oculaire dans trois cas. Un nodule palpébral est retrouvé dans un cas ; une conjonctivite folliculaire dans un cas ; une kératite interstitielle dans un cas ; une uvéite dans trois cas.  Le diagnostic est posé sur l’aspect clinique et sur un faisceau d’arguments para-cliniques. La chimiothérapie a été instituée chez tous les malades avec un traitement anti-inflammatoire stéroïdien dans trois cas. L’évolution a été favorable dans cinq cas sur six. La tuberculose oculaire est une affection moins rare qu’auparavant. Elle connaît une recrudescence ces dernières années due à l’extension du SIDA et des formes multi résistantes. L’atteinte du tractus uvéal est la manifestation oculaire la plus fréquente. Le diagnostic repose sur un faisceau d’arguments cliniques, biologiques, para-cliniques et histologique. Le traitement de la tuberculose est d’abord préventif. Les auteurs insistent sur les problèmes diagnostiques de la tuberculose oculaire et sur la nécessité d’une surveillance ophtalmologique régulière des patients sous traitement antibacillaire