[en] The commercial aviation sector accounts for 2.5 % of total worldwide anthropogenic carbon dioxide (CO₂) emissions. Water vapour (H₂O) and NO_x emissions, the formation of condensation trails and increased formation of cirrus clouds due to altitude (indirect effects) also accentuate the greenhouse effect. The Intergovernmental Panel on Climate Change (IPCC) estimates that the effects apart from CO₂ emissions are relatively higher for aviation than for other human activities. For one tonne of CO₂ emissions, the radiative forcing of aviation is twice as important as other activities. On this basis, a Paris-New York return trip for one passenger on a charter flight corresponds to a quarter of the total climate impact caused by the annual consumption of a French person. Increased mobility and a rise in international tourism suggest that past trends in the growth of air passenger transport will continue. The improvements in energy efficiency achieved are seemingly not sufficient to prevent a significant increase in the impact of air transport on climate change. (author)

[en] Prediction of seasonal epidemics have been widely treated in the medical literature, with various methods to forecast the future cases of a given disease, when it’s about infectious diseases: compartmental methods that forecast the number of persons at each state of the epidemic (susceptible, infected, resistant) are used (1), as well as methods based on time series (ARMA ,ARCH,…)(2), this last method can be successful with large sample of data, assuming their normal distribution. Here, we propose to test time series for count data when the continuous time series are not adapted to predict health activity. The aim of this work is to predict the number of hospital admissions of future weeks at local scale, using methods for integer-valued time series: INAR(p) and INGARCH(p,q) methods(3– 5), we have also test the autoregressive methods for continuous data.

[en] The development of the tertiary sector appears to support sustainable development since it now accounts for almost two thirds of the national economy and is responsible for low CO₂ emission levels. Between 1980 and 1997, CO₂ emissions from the tertiary sector increased by 20 % compared with a 48 % rise in the sector value added. In terms of production, CO₂ levels in the tertiary sector are low, compared with 55 % for the secondary sector (industry). However, when trade between economic activities is taken into account, there is cause to qualify the assessment. This makes it possible to ascertain emissions from the point of view of satisfying final demand for products, and to identify direct and indirect emissions in each branch of activity. Thus, when emissions from certain industrial and agricultural activities are redistributed specifically to branches of activity in the tertiary sector, CO₂ emissions in this sector account for almost one-third of total emissions. (A.L.B.)

[en] The study of pressure vessel accidents and degradation processes that lead to rupture is very useful to improve the reliability of vessels and accordingly that of nuclear boilers. The accident statistics are very insufficient in France, nevertheless it is possible to classify the accidents in categories and to determine the accident probability in each category. Some cases of accidents and ruptures are analyzed and two of them are particularly discussed

[en] A range of commercially important powders (hydrated alumina, limestone, titania and zeolite) and glass ballotini were attached to atomic force microscope cantilevers, and inter-particle friction forces studied in air using lateral force microscopy (LFM). The in situ calibration procedure for friction forces is described. LF images, line profiles, LF histograms, surface roughness, pull-off forces, and the load dependence of friction in the range 0-25 nN were studied for both particle-particle and particle-wall (steel) contacts. The single-particle friction results are discussed in terms of contact mechanics theory. Particle-particle contacts showed load-dependent friction, involving single asperity contacts (non-linear behaviour) or multi-asperity contacts (linear behaviour). Particle-wall contacts usually showed little load dependence and were more adhesive. The results are also related to shear stress-normal stress data (yield loci) for the same materials from bulk shear testers

[en] This paper addresses the problem of finding appropriate method for analysis of non-stationary time series with complex trends and possibly with distinct periodic components in power spectrum. A well established Multifractal Detrended Fluctuation Analysis (MDFA) combined with Singular Spectrum Analysis (SSA) used on several artificial examples to demonstrate the capabilities of the method. In this combined method SSA is used for nonparametric periodic components extraction and for adaptive automatic nonparametric trend extraction.

[en] The Rayleigh-Brillouin spectrum of light scattered from hydrogen at high densities is reported. The observations are compared with translational hydrodynamic theory and ultrasonic experiments. The range of densities includes the relaxation region and we find evidence for multiple relaxation. A mean relaxation time for normal hydrogen at 24 deg C of (1.41 +- 0.06) x 10^-8 s is found, in agreement with theoretical calculations. (author)

No abstract available

[en] In the study of microscopic flows, self-propulsion has been particularly topical in recent years, with the rise of miniature artificial swimmers as a new tool for flow control, low Reynolds number mixing, micromanipulation or even drug delivery. It is possible to take advantage of interfacial physics to propel these microrobots, as demonstrated by recent experiments using the proximity of an interface, or the interface itself, to generate propulsion at low Reynolds number. This paper discusses how a nearby interface can provide the symmetry breaking necessary for propulsion. An overview of recent experiments illustrates how forces at the interface can be used to generate locomotion. Surface swimmers ranging from the microscopic scale to typically the capillary length are covered. Two systems are then discussed in greater detail. The first is composed of floating ferromagnetic spheres that assemble through capillarity into swimming structures. Two previously studied configurations, triangular and collinear, are discussed and contrasted. A new interpretation for the triangular swimmer is presented. Then, the non-monotonic influence of surface tension and viscosity is evidenced in the collinear case. Finally, a new system is introduced. It is a magnetically powered, centimeter-sized piece that swims similarly to water striders. Graphical abstract:

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[en] The LOTIS Collimator provides scene projection within a 6.5m diameter collimated beam used for optical testing research in air and vacuum. Diffraction-limited performance (0.4 to 5μm wavelength) requires active wavefront control of the alignment and primary mirror shape. A hexapod corrects secondary mirror alignment using measurements from collimated sources directed into the system with nine scanning pentaprisms. The primary mirror shape is controlled with 104 adjustable force actuators based on figure measurements from a center-of-curvature test. A variation of the Hartmann test measures slopes by monitoring the reflections from 36 small mirrors bonded to the optical surface of the primary mirror. The Hartmann source and detector are located at the f/15 Cassegrain focus. Initial operation has demonstrated a closed-loop 110nmrms wavefront error in ambient air over the 6.5mcollimated beam.