The deuterium/hydrogen distribution in chondritic organic matter attests to early ionizing irradiation

International audiencePrimitive carbonaceous chondrites contain a large array of organic compounds dominated by insoluble organic matter (IOM). A striking feature of this IOM is the systematic enrichment in deuterium compared with the solar hydrogen reservoir. This enrichment has been taken as a sign of low-temperature ion-molecule or gas-grain reactions. However, the extent to which Solar System processes, especially ionizing radiation, can affect D/H ratios is largely unknown. Here, we report the effects of electron irradiation on the hydrogen isotopic composition of organic precursors containing different functional groups. From an initial terrestrial composition, overall D-enrichments and differential intramolecular fractionations comparable with those measured in the Orgueil meteorite were induced. Therefore, ionizing radiation can quantitatively explain the deuteration of organics in some carbonaceous chondrites. For these meteorites, the precursors of the IOM may have had the same isotopic composition as the main water reservoirs of the inner Solar System

Etude des relations structure - propriétés de films soufflés multicouches de type PE/liant/PA6

National audienc

Techniques for Securing Web Content

Abstract: This paper analyzes the dangers to which web content is exposed, demonstrates how data from the Internet can be gathered and used to obtain profit, how an application can stealthily make use of complicated processing without implementing them and how a website can be cloned in real time. For the considered attacks and vulnerabilities I present, explain, group and evaluate the existing solutions to secure content and last but not least, I suggest a new solution: a library for link encryption

FIR and Submm Optical Properties of Astrophysically Relevant Minerals

International audienc