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34 results on '"Pitet, L."'

1. L'avalanche du Bourgeat survenue le 9 janvier 2018

Author

Naaim-Bouvet, F., Bellot, H., Caccamo, P., Naaim, Mohamed, Ousset, F., Thibert, Emmanuel, Ravanat, X., Faug, T., Pitet, L., Segor, V., Maggioni, M., Bruno, E., Godone, D., Ceaglio, E., Viglietti, D., Freppaz, M., Barbero, M., Barpi, F., Borri-Brunetto, M., Bovet, E., Chiaia, B., De Biagi, V., Frigo, B., Pallara, O., Érosion torrentielle, neige et avalanches (UR ETGR (ETNA)), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), REGIONE AUTONOMA VALLE D'AOSTA ITA, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), UNIVERSITA DEGLI STUDI DI TURINO ITA, DISTR POLITECNICO DI TORINO ITA, and INRAE

Subjects
[PHYS]Physics [physics], [SPI]Engineering Sciences [physics], [SDE]Environmental Sciences, [PHYS.MECA]Physics [physics]/Mechanics [physics]
Abstract

Chapeau. Le 9 janvier 2018, autour de 7h15, une avalanche d'ampleur significative descend le couloir du Bourgeat. L'écoulement de neige poudreuse, également appelé aérosol, détruit la forêt sur une largeur très importante et franchit le paravalanche du Bourgeat. Une quarantaine de chalets en aval de la digue terminale du paravalanche sont recouverts de neige par l'aérosol, et de nombreux arbres sont détruits et transportés par l'aérosol, ce qui cause les principaux dégâts qui restent fort heureusement uniquement matériels. Lors de sa propagation dans le couloir, l'écoulement dense, de neige froide au départ, se transforme en un écoulement plus lent, de neige humide, et interagit de manière complexe avec le paravalanche qui, in fine, contient bien la masse de neige lourde. Cet article propose une brève analyse qualitative des différentes hypothèses concernant les conditions de déclenchement, de propagation de l'aérosol et des écoulements denses et de leur interaction avec le paravalanche. Il dresse également une liste de questions qui peuvent se poser suite à cet événement.

Published
2018

12. Comparison between three avalanche test sites in northwestern Alps as developed in the DYNAVAL-Alcotra project

Author

Pitet, L., Segor, V., Naaim-Bouvet, F., Bellot, H., Caccamo, P., Naaim, Mohamed, Ousset, F., Thibert, Emmanuel, Ravanat, X., Faug, T., Maggioni, M., Bruno, E., Godone, D., Ceaglio, E., Viglietti, D., Freppaz, M., Barbero, M., Barpi, F., Borri-Brunetto, M., Bovet, E., Chiaia, B., De Biagi, V., Frigo, B., Pallara, O., DIREZIONE ASSETTO IDROGEOLOGICO DEI BACINI MONTANI REGIONE AUTONOMA VALLE D'AOSTA ITA, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Érosion torrentielle, neige et avalanches (UR ETGR (ETNA)), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), DI VAPRA LNSA CHIMICA AGRARIA E PEDOLOGIA UNIVERSITA DI TORINO ITA, and DISTR POLITECNICO DI TORINO ITA

Subjects
TACONNAZ, ARVES, AVALANCHE FLOW, DYNAVAL, [SDE]Environmental Sciences, FRANCE, COL DU LAUTARET, AOSTE VALLEE, ITALIE
Abstract

International audience; Within the Operational programme 'Italy - France (Alps - ALCOTRA) 'Project DynAval - Dynamique des avalanches: départ et interactions écoulement/obstacles three test sites were built or developed in France and Italy. The goal of the paper is to present the experimental devices and typical pressure generated by avalanches in these 3 sites differing mainly by their scale. (a) Seehore test site is located in Aosta Valley on Monte Rosa Massif. The slope, with an altitude difference of about 300 m (from 2300 to 2570 m a.s.l.), has a mean dip of about 38°. The site is instrumented with a steel obstacle on which load cells and other devices are mounted in order to measure the effects of impact of the avalanche. Surveys are made before and after each artificial event: snow density, front velocity, erosion and deposition are measured and photogrammetric and laser-scanner views are taken. (b) Col du Lautaret test site is located near the Lautaret pass (2058 m a.s.l) between Cerces and Ecrins range. Different avalanche paths are located on the south-east slope of Chaillol Mountain (2600 m a.s.l.). Small to medium avalanches occur at a sufficient frequency (up to 3 or 4 each winter). Avalanche flows are generally dense, wet or dry, with sometimes a small but fast powder cloud (or saltation layer). The dense part is usually less than one meter thick. The run-out distance is 500 to 800 m with an average gradient of 36°. Typical released volume is about 5000 m3 and front velocity can reach 30 m/s. Instrumentation includes a 3 m-high mast recording pressure and velocity each 20 cm, and a one square meter plate integrating the pressure all over the flow height. A high speed photogrammetric system is able to measure the avalanche front velocity. (c) The Taconnaz avalanche path is located in the Arves valley, close to Mont Blanc in France. The Taconnaz path is 7 km long, has a mean slope of 25° and a mean width of 300400 m. A defence structure system made of breaking mounds and dams was designed in 2009 based on a 100-year return period event of 1.6 Mm3 volume. In 2010, velocity and pressure sensors were set up on the breaking mounds in order to improve our knowledge of the interaction between avalanches and breaking dams.

Published
2011

13. Dynamique des avalanches : déclenchement et interaction flux / obstacle

Author

Segor, V., Pitet, L., Faug, T., Naaim-Bouvet, F., Naaim, Mohamed, Thibert, Emmanuel, Irstea Publications, Migration, REGION AUTONOMA VALLE D'AOSTE ITA, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Érosion torrentielle, neige et avalanches (UR ETGR (ETNA)), and Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF)

Subjects
TACONNAZ, [SDE] Environmental Sciences, PUNTA SEEHORE, [SDE]Environmental Sciences, COL DU LAUTARET
Abstract

International audience; L'article traite du projet DYNAVAL (financement INTERREG Alcotra) mené de 2009 à 2012 entre la Region Autonome de la Vallée d'Aoste et le Cemagref de Grenoble. Le projet s'appuyait sur la mise en place ou le renforcement de sites expérimentaux avalanches à différentes échelles Ces sites permettent de mieux comprendre et le déclenchement et l'intéraction entre les avalanches et les obstacles. Trois sites complémentaires sont ainsi décrits : - Punta Seehore (Italie) : Petite échelle - Col du Lautaret (France) : Moyenne échelle - Taconnaz (France) : Grande échelle

Published
2011

14. Monitoraggio del sito sperimentale della Punta Seehore

Author

Segor, V., Pitet, L., Chiaia, Bernardino, Frigo, Barbara, Barbero, Monica, Barpi, Fabrizio, BORRI BRUNETTO, Mauro, Bovet, Eloise, DE BIAGI, Valerio, Pallara, Oronzo Vito, Zanini, E., Freppaz, M., Maggioni, M., Bruno, E., Ceaglio, E., Godone, D., Viglietti, D., Brulport, A., and Bornaz, Leandro

Published
2011

16. Il distacco artificiale a Punta Seehore: metodologie impiegate e campagna sperimentale

Author

Segor, V., Pitet, L., Chiaia, Bernardino, Frigo, Barbara, Barbero, Monica, Barpi, Fabrizio, BORRI BRUNETTO, Mauro, Bovet, Eloise, DE BIAGI, Valerio, Pallara, Oronzo Vito, Zanini, E., Freppaz, M., Maggioni, M., Bruno, E., Ceaglio, E., Godone, D., Viglietti, D., Brulport, A., Cardu, Marilena, Giraudi, Alessandro, Godio, Alberto, and Rege, ROBERTO BRUNO

Published
2011

17. Il sito sperimentale della Punta Seehore

Author

Segor, V., Pitet, L., Chiaia, Bernardino, Frigo, Barbara, Barbero, Monica, Barpi, Fabrizio, BORRI BRUNETTO, Mauro, Bovet, Eloise, DE BIAGI, Valerio, Pallara, Oronzo Vito, Zanini, E., Freppaz, M., Maggioni, M., Bruno, E., Ceaglio, E., Godone, D., Viglietti, D., and Brulport, A.

Published
2011

18. Dinamica delle valanghe: distacco e interazione flusso/ostacoli

Author

Segor, V., Pitet, L., Chiaia, Bernardino, Frigo, Barbara, Barbero, Monica, Barpi, Fabrizio, BORRI BRUNETTO, Mauro, Bovet, Eloise, DE BIAGI, Valerio, Pallara, Oronzo Vito, Zanini, E., Freppaz, M., Maggioni, M., Bruno, E., Ceaglio, E., Godone, D., Viglietti, D., and Brulport, A.

Published
2011

19. Prove sperimentali al sito della Punta Seehore nelle stagioni 2010 e 2011

Author

Segor, V., Pitet, L., Chiaia, Bernardino, Frigo, Barbara, Barbero, Monica, Barpi, Fabrizio, BORRI BRUNETTO, Mauro, Bovet, Eloise, DE BIAGI, Valerio, Pallara, Oronzo Vito, Zanini, E., Freppaz, M., Maggioni, M., Bruno, E., Ceaglio, E., Godone, D., Viglietti, D., Brulport, A., and Bornaz, Leandro

Published
2011

20. Preliminary measurements and survey at the Italian avalanche test site Punta Seehore

Author

Barbero, Monica, Barpi, Fabrizio, Bornaz, Leandro, BORRI BRUNETTO, Mauro, Bovet, Eloise, Bruno, E., Ceaglio, E., Chiaia, Bernardino, DE BIAGI, Valerio, Fassin, D., Freppaz, M., Frigo, Barbara, Godone, D., Maggioni, M., Pallara, Oronzo Vito, Pitet, L., Segor, V., Torretta, F., Viglietti, D., Welf, A., and Zanini, E.

Published
2011

26. Altering Mechanical Properties to Improve Electrode Contacts by Organic Modification of Silica-Based Ionogel Electrolytes for Sodium-Ion Batteries.

Author

Mercken J, De Sloovere D, Joos B, Calvi L, Mangione G, Pitet L, Derveaux E, Adriaensens P, Van Bael MK, and Hardy A

Abstract

Sodium-ion batteries (SIBs) are a possible candidate to create safe, sustainable, and cost-effective batteries. Solid sodium-ion conducting organically modified ionogel electrolytes are investigated. Silica-based ionogels typically consist of an ionic liquid electrolyte (ILE) confined within a silica matrix and possess high thermal stability, good ionic conductivity, safety, and good electrochemical stability. However, they readily deteriorate when stress is applied, decreasing the electrolyte's and battery's overall performance. The mechanical characteristics of silica can be improved using organic moieties, creating Ormosils®. Silica-based ionogels with phenyl-modified silanes improve the mechanical characteristics by a reduction of their Young's modulus (from 29 to 6 MPa). This is beneficial to the charge-transfer resistance, which decreases after implementing the electrolyte in half cells, demonstrating the improved interfacial contact. Most importantly, the phenyl groups change the interacting species at the silica interface. Cationic imidazolium species pi-stacked to the phenyl groups of the silica matrix, pushing the anions to the bulk of the ILE, which affects the ionic conductivity and electrochemical stability, and might affect the quality of the SEI in half cells. In essence, the work at hand can be used as a directory to improve mechanical characteristics and modify and control functional properties of ionogel electrolytes., (© 2023 Wiley-VCH GmbH.)

Published
2023
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27. [Three-dimensional imaging of the carpus].

Author

Moutet F, Chapel A, Cinquin P, and Rose-Pitet L

Subjects
Humans, Carpal Bones diagnostic imaging, Tomography, X-Ray Computed methods
Abstract

Since 1987, the authors have developed three-dimensional (3D) imaging of the carpus. This reconstruction based on 30 CT scans of the carpus is a new approach to imaging and allows spatial visualisation of the complex shapes of the carpal skeleton from all angles. The development of this technique should lead to a better understanding of the intimate physiology of the carpus and should allow the development of a real simulator of the wrist for precise planning of surgical procedures (osteotomy, intracarpal arthrodeses, etc.). It also helps to elucidate complex pathological images which are not always easy to interpret on CT scans.

Published
1990

29. [The operability evaluation of bronchial cancer. Respective value of x-ray computed tomography and magnetic resonance imaging. Comparison with axial mediastinoscopy. Apropos of 61 patients].

Author

Brichon PY, Blanc-Jouvan F, Rose-Pitet L, Coulomb M, Brambilla E, Premy M, Pilichowski P, Sarrazin R, and Latreille R

Subjects
Adult, Aged, Aged, 80 and over, Bronchial Neoplasms pathology, Female, Humans, Magnetic Resonance Imaging, Male, Mediastinoscopy, Middle Aged, Neoplasm Staging, Prospective Studies, Tomography, X-Ray Computed, Bronchial Neoplasms surgery
Published
1988

30. [Neonatal septicemia and arthritis caused by an unusual germ].

Author

Plasse M, Stahl JP, Rose-Pitet L, Joannard A, Guillen MC, and Beaudoing A

Subjects
Female, Humans, Infant, Newborn, Pasteurella Infections drug therapy, Penicillins therapeutic use, Arthritis, Infectious microbiology, Infant, Newborn, Diseases microbiology, Pasteurella Infections diagnosis, Sepsis microbiology
Published
1982

32. [Magnetic resonance imaging in dissection of the aorta].

Author

Wolf JE, Rose-Pitet L, Pilichowski P, Reboud JP, Vailloud G, Lebas JF, Bourlard P, Machecourt J, Coulomb M, and Denis B

Subjects
Adult, Aged, Aortic Dissection surgery, Aorta, Aorta, Thoracic, Aortic Aneurysm surgery, Blood Flow Velocity, Blood Vessel Prosthesis, Female, Humans, Male, Middle Aged, Postoperative Period, Aortic Dissection diagnosis, Aortic Aneurysm diagnosis, Magnetic Resonance Imaging
Abstract

In order to evaluate the usefulness of this new exploratory method in dissection of the aorta, 13 patients (10 men and 3 women, mean age 58 +/- 14 years) were examined by means of an 0.5 Tesla Magniscan 5000 nuclear magnetic resonance machine. Fifteen examinations were performed: 5 in patients with actual aortic dissection (type A 4 including one acute, type B1), 5 in patients previously operated upon for type A dissection and 5 for suspected acute aortic dissection unconfirmed by other examinations. Magnetic resonance imaging (MRI), synchronized with electrocardiography, was carried out using spin-echo techniques with 1 to 3 echoes and multiple contiguous sections along several planes. In the 5 patients with actual dissection the 2 channels separating the membrane could be demonstrated, thus providing a firm diagnosis (MRI proved superior to angiography in 2/5 patients). All 5 patients could be classified as either type A or type B. Extension to the cervical vessels was observed in 3 cases and the portal of entry was seen in one case, but the origin of the coronary arteries was never visualized. In the 5 patients previously operated upon MRI provided detailed analysis of the prosthesis of the supra-coronary ascending aorta implanted in all cases, of the aorta proximal and distal to that segment and of the periaortic mediastinum. By studying the signal from the false channel distal to the prosthesis information was obtained as to the presence in it (2 patients) or absence of circulating blood.(ABSTRACT TRUNCATED AT 250 WORDS)

Published
1987

33. [Comparative study of magnetic resonance imaging and tomodensitometry in the diagnosis of locoregional extension in 61 patients with bronchial cancers].

Author

Blanc-Jouvan F, Rose-Pitet L, Brichon PY, Brambilla E, Aguilaniu B, Latreille R, Sarrazin R, Coulomb M, Paramelle B, and Brambilla C

Subjects
Bronchial Neoplasms diagnosis, Bronchial Neoplasms diagnostic imaging, Female, Humans, Male, Mediastinoscopy, Neoplasm Staging, Prospective Studies, Bronchial Neoplasms pathology, Magnetic Resonance Imaging, Tomography, X-Ray Computed
Abstract

In order to assess the value of nuclear magnetic imagery NMR in the diagnosis of the extent of bronchial cancers, 61 patients with operable bronchial carcinoma had both a CT scan and an NMR scan pre-operatively. Fifty one mediastinoscopies were performed. Twelve times there were mediastinal glandular enlargement. Ten times the thoracotomy was performed straight away. After pathological studies of the biopsy, 24 patients were N2, 25 N1, 12 N0; the sensibility of NMR to foresee lymph node invasions was 83% (specificity 70%), for CT scanning 75% (specificity 81%). Thirteen patients presented with a direct mediastinal or parietal invasion. The sensibility of detecting these invasions was only 38% for NMR (specificity 94.5%) and for CT scanning 54% (specificity 94.5%). There is little difference in the results and no statistical difference. This leads us to conclude that at present, NMR does not give more information than TDM in the diagnosis of operability in bronchial cancers.

Published
1987

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