Papers by Author: Antoine Aboukaïs

Abstract: To guarantee the reliability and safe operation of large-scale metallic structures exposed to cryogenic temperatures for extended periods, it is important to evaluate structural properties of the base metal as well as the welded zone in order to prevent damages that could occur. Spatially-resolved high-energy synchrotron diffraction, pulsed neutron diffraction and small-angle neutron scattering have been used to study short, intermediate and mesoscopic range order in cryogenic 9Ni steel as well as the structural changes induced by the welding. Pristine 9Ni steel appears to be a metastable Fe-Ni alloy with main bcc martensitic phase and a minority fcc austenitic phase. Welding of 9Ni steel using SMAW technique has revealed a fast intergranular nickel diffusion at high temperatures during welding originated from high nickel content in the SMAW welding alloy.

Abstract: Atmospheric Total Suspended Particles (TSP) were sampled from 16 different points in a coastal industrial region in North Lebanon, between April and October 2008. The samples were analyzed for water soluble ions and metals concentrations using Ion Chromatography (I.C.) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The results showed possible natural contribution to aerosols through sea salt emissions (Na/Cl-/Mg), and crustal sources (K/Fe/Ti). However, ions such as NH4+, NO3-, and SO42- were attributed to secondary aerosols. Finally, the result of the enrichment factor analysis showed that vehicles’ emissions (Zn/Cu/Pb/Ni/V/Cr), quarries (Ca), and phosphate rocks impurities (Zn/Cd/Cu/Pb) were the most important anthropogenic contributions to the metal’s load in the aerosols.