Abstract: The invention concerns a method for producing an oxygen-containing compound used as fuel additive, in particular in diesel fuels, gasoline and rapeseed methyl ester. The method consists in a) reacting a polyvalent alcohol with an aldehyde or a ketone to produce an acetal and b) etherifying the subsisting free hydroxyl groups in the acetal produced at step a) with tertiary olefins.

Abstract: A method for work-hardening a component to be loaded along a loading axis includes rolling in a notch extending approximately at right angles to the loading axis. The notch has a minimum radius of curvature to be determined in a cross-section parallel to the loading axis. The notch is work-hardened by rolling along a plurality of tracks being adjacent one another along the loading axis and being directed approximately at right angles to the loading axis, with each track covering only a part of the notch. Compressive internal stresses are generated which have axial components and tangential components relative to the loading axis. The axial components are substantially larger than the tangential components. The method is particularly suitable for work-hardening by rolling of a retention groove in a root part of a turbine blade.