A process for preparing a catalyst precursor comprises subjecting, in an initial treatment stage, a slurry of a catalyst support, an active catalyst component precursor, and water, to treatment at elevated temperature and at sub-atmospheric pressure, to impregnate the support with the precursor and to dry the impregnated support partially. andor by more than approximately 50\xb0 C. Said functional recess is machined out of said quantity of property-improving material. At least one of the pair of arms is movable. The apparatus includes: a first operating system; a second operating system; a USB hub, connected to at least one USB apparatus; and a switch, for disconnecting the first operating system from the USB hub and connecting the second operating system to the USB hub for gaining control over the at least one USB apparatus when the first operating system is switched to the second operating system. R1, R2=H or C1-C10 alkyl group A=Substituted phenyl group corresponding to a compound of formula or, R3, R4=H or C1-C4 alkyl group, m=0 or 1-4, n=1 to 5, k=1 or 2.