Les responsabilités et assurances : droit commun ou application de la loi du 4 janvier 1978 ?

Durry Georges. Les responsabilités et assurances : droit commun ou application de la loi du 4 janvier 1978 ?. In: Droit et Ville, tome 8, 1979. La réhabilitation de l'habitat existant. pp. 169-176

Balloon-borne near-infrared diode laser spectroscopy for in situ measurements of atmospheric CH<SUB>4</SUB> and H<SUB>2</SUB>O

International audienceAbsorption spectroscopy with near-infrared telecommunication laser diodes is a very convenient technique to measure in situ methane and water vapor in both the troposphere and the lower stratosphere (LS) and thereby to address many topics in the science of the atmosphere. This technique offers a high temporal resolution that ranges from 10 ms to 1 s, a precision error in the concentration retrieval of within a few percents and a dynamic range for the measurements of four orders of magnitude. A balloon-borne near-infrared diode laser spectrometer is described that provides simultaneous in situ methane (in the 1.65-μm region) and water vapor (in the 1.39-μm region) measurements at 1 s intervals. Tropospheric and stratospheric vertical concentration profiles of methane and water vapor are reported

Chronique des Études anciennes

Radet Georges, Mathieu Georges, Durry Marcel. Chronique des Études anciennes. In: Revue des Études Anciennes. Tome 35, 1933, n°3. pp. 377-384

In situ measurements of H₂O from a stratospheric balloon by diode laser direct-differential absorption spectroscopy at 1.39 µm

International audienceA distributed-feedback InGaAs laser diode emitting near 1.393 µm is used in conjunction with an optical multipass cell that is open to the atmosphere to yield ambient water-vapor measurements by infrared absorption spectroscopy. To obtain the high dynamic range for the measurements that is required for continuous water-vapor monitoring in the upper troposphere and the lower stratosphere, we used a simple circuit that combined differential and direct detection. Furthermore, the laser emission wavelength was tuned to balance the steep decrease in H2O concentration with altitude by sweeping molecular transitions of stronger line strengths. The technique was implemented by use of the Spectromètre à Diodes Laser Accordables (SDLA), a tunable diode laser spectrometer operated from a stratospheric balloon. Absorption spectra of H2O in the 5–30-km altitude range obtained at 1-s intervals during recent balloon flights are reported. Water-vapor mixing ratios were retrieved from the absorption spectra by a fit to the full molecular line shape in conjunction with in situ pressure and temperature measurements, with a precision error ranging from 5% to 10%

Chronique des Études anciennes

Radet Georges, Mathieu Georges, Durry Marcel. Chronique des Études anciennes. In: Revue des Études Anciennes. Tome 35, 1933, n°3. pp. 377-384

Extinction layer detected by the 2003 star occultation on Pluto

International audienceA star occultation by Pluto was monitored in August 2003 by several telescopes, at several wavelengths between 0.7μm and 2.23μm. Besides information concerning pressure and temperature profiles, this observation revealed a chromatic effect in the light transmitted through the atmosphere at the limb. It was attributed to an extinction layer produced by spherical particles of about 0.2 μm, and it was suggested that such large particle size may be due to fractal particles as on Titan. In this paper, we use an aerosol microphysical model to estimate if such extinction could be due to photochemical aerosols only. We use the case of Titan to scale the haze production rate on Pluto and we show that the chromatic effect is not likely to be produced in this way. We then study how a troposphere in Pluto's atmosphere could generate condensation droplets. We conclude that such an extinction layer is produced by condensation droplets that potentially could grow as large as observed. We find that only N2 and CO are able to condense easily. CH4 probably does not condense or, if it does, it needs to reach a very high saturation ratio and, in any case, is supersaturated on Pluto. Noteworthily, a similar layer was observed on Triton by Voyager. Finally, at the end of the paper we discuss which are the conditions to detect a chromatic effect for submicrometer to micrometer particles in future observations

Evidence for long-lived polar vortex air in the mid-latitude summer stratosphere from in situ laser diode CH₄ and H₂O measurements

International audienceA balloon borne diode laser spectrometer was launched in southern France in June 2000 to yield in situ stratospheric CH4 and H2O measurements. In the altitude region ranging from 20 km to 25 km, striking large spatial structures were observed in the vertical concentration profiles of both species. We suggest these patterns are due to the presence of long-lived remnants of the wintertime polar vortex in the mid-latitude summer stratosphere. To support this interpretation, a high resolution advection model for potential vorticity is used to investigate the evolution of the Arctic vortex after its breakdown phase in spring 2000

Sondage atmosphérique par diode laser (application à la détection in situ de H2O, CH4 et CO2 dans la troposphère et la basse stratosphère)

PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF