In this work we concentrate on an experimental validation of the Lifshitz theory for the van der Waals and the Casimir forces in gold-alcohol-glass systems. From this theory weak dispersive forces are predicted when the dielectric properties of the intervening medium become comparable to one of the interacting surfaces. Using inverse colloid probe atomic force microscopy dispersive forces were measured occasionally and under controlled conditions by addition of salt to screen the electrostatic double layer force if present. The dispersive force was found to be attractive and an order of magnitude weaker than that in air. Although the theoretical description of the forces becomes less precise for these systems even with full knowledge of the dielectric properties, we find still our results in reasonable agreement with the Lifshitz theory.

This paper reports on the mechanical strength of highly porous ceramics in terms of the Weibull and Duxbury-Leath distributions.More than 1000 side-crushing strength tests on silicacatalyst carriers of various particle sizes have been performed in series. Within a series, preparation conditions were kept constant. Analysis of the fluctuations of the failure pressure around its expectation value proves that the length dependence of the mechanical strength is well described by both distributions.

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Spin lattice relaxation time in the rotating frame [T1ρ] is investigated in pure NaCl single crystals as a function of temperature in-situ during deformation. Transition from 2- phonon Raman process to atomic diffusion was noted at around 500K in the undeformed material and the activation energy was determined to be that for the diffusion of extrinsic vacancies. Enhanced spin relaxation rates were noted during constant strain-rate deformation at temperatures from ambient to about 750K. These enhancements were identified to arise from dislocation motion at lower temperatures while enhanced diffusion due to excess vacancies at higher temperatures. This excess concentration increased with increased strain-rate and in-situ annealing of deforma-tion induced excess vacancies is noted at high temperatures.

During laser alloying, a melt pool is created at the passage of a laser beam in which mixing occurs by convection because of surface tension gradients. This mixing process in the melt bath is reported here in different alloying elements on aluminium (manganese, nickel, cobalt) and steel (nickel) substrates and a homogeneous distribution did not appear to be evident. It is concluded that density differences, interface tensions and diffusion are the main factors affecting the mixing process.