4,375 datasets found

The variations of the metabolism of the glaciers and the polar ice sheets reflect the climate fluctuations. On the yearly time scale, these fluctuations result in...

Many questions of glaciological interest can be recognized as inverse problems. In this thesis, l illustrate this point through three examples: * Reconstruction of...

Observations of crystal orientations on deep ice-cores from Antactica and Greenland have shown that polar ice acquires a fabric, characteristic of the strain-history...

The 420 000-year climatic and atmospheric record represented by the Vostok ice core, gives a unique opportunity to reconstruct evolution of atmospheric carbon dioxide...

Direct aerosol radiative forcing is modulated by many factors, including the chemical nature of the components and their size distribution, and the variability of...

The Illimani ice cores, extracted in 1999 in the Bolivian Andes thanks to the GREAT ICE team of IRD and analysed over the following years at LGGE, have shown a strong...

The presence of snow locally modifies the atmospheric concentrations of trace gases. This is confirmed by numerous and recent experimental observations that raised the...

The ice single crystal possesses a strong viscoplastic anisotropy, it deforms mainly by dislocation glide in the basal plane. A constitutive model for the single...

Interstitial air extracted from the firn at 4 polar sites has given access to air samples aging back to a hundred years in sufficient amount for isotopic analysis of...

The analysis of isotope ratios is of increasing importance to study the sources and sinks of atmospheric trace gases and to investigate their chemical reaction...

The mineral dust of continental origin windblown to the East Antarctic Plateau has been studied for its geographical provenance and variability during the Quaternary....

In order to unserstand the fragement production which occurs in heavy ion collisions at intermediate energies we have performed in this work an expérimental and...

The aim of this study is to bring new elements concerning the astronomical theory of paleoclimates using two tools : glaciological dating of polar ice cores using an...

Software tools for risk analysis contribute to the quality control of products, notably by allowing the identification of their potential failure modes. The thesis...

The main goals of the present study are, first, determination of the relationship between local air temperature and snow isotope composition at Vostok Station (East...

Generally, Operating Systems control and execute applications based on a best effort policy. As long as resources are sufficient, applications are normally executed...

The sphingolipids are a family of membrane lipids with only a structural role, influencing lipid bilayer properties, but they also act as effector molecules with...

The life time of mechanical components can be increased by the presence of compressive residual stresses. Inherent to most production processes, residual stresses play...

Ferroelectric materials are characterized by their spontaneous polarization, whose direction can be reversed by the application of a suitable electric field. Using...

This thesis falls under an approach of investigation on the damage mechanisms of high zirconia fused-cast refractories. The focus is particularly set on the...