Abstract: The invention relates to gas chromatography analysis of a sample having components to be investigated and water contained therein, which after thermodesorption is separated and analyzed, the thermodesorbed sample being transferred by means of carrier gas into a first polar separation column which retains higher-boiling components and water and passes low-boiling components, the lafter being led, past a branching point which leads, on the one hand, to a second polar or non-polar separation column and, on the other hand, to the non-polar separation column, to the non-polar separation column in a fashion excluding access to the second polar or non-polar separation column, after which higher-boiling components and water are transferred to the second polar or non-polar separation column in a fashion excluding access to the non-polar separation column, water being eliminated upstream of the second polar or non-polar separation column by means of cryofocussing.

Abstract: A process is described for the production of 3-alkyl-3-hydroxymethyloxetanes of the general formula (1), ##STR1## in which R.sup.1 denotes a linear or branched C.sub.1 -C.sub.12 alkyl group, which process comprises reacting a trimethylolalkane of the general formula (2),(HO--CH.sub.2).sub.3 C--R.sup.1 (2)in which R.sup.1 is defined as above, with a dialkyl carbonate of the general formula (3),R.sup.2 --O--(C.dbd.O)--O--R.sup.2 (3)in which R.sup.2 denotes a linear or branched C.sub.1 -C.sub.4 alkyl group, in the presence of a basic catalyst, wherein in a first stage the reaction mixture is stirred for at least 6 hours with refluxing at a temperature of 90-120.degree. C., in a second stage the alcohol formed R.sub.2 OH is distilled off at the same temperature and in a third stage the product formed is decarboxylated and deoligomerised at a temperature of 125-150.degree. C. and the desired 3-alkyl-3-hydroxymethyloxetane is simultaneously distilled off.

Abstract: A sunroof, for a motor vehicle having a roof opening, includes a roof frame locatable in the roof opening for defining the perimeter of the roof opening and at least one panel fitting within the roof frame arranged to close the roof opening. The panel is hingedly mounted to the roof frame at a forward panel edge so that the panel can pivot about the hinged mounting so as to rise at a rear panel edge to open the sunroof. A positioning device is arranged adjacent the rear panel edge to hold the panel open. The positioning device includes at least an upper link and a lower link connected pivotally together at a knee joint which is movable with respect to the roof frame, with the upper link being connected to the panel at the end of the panel opposite the knee joint and the lower link being connected to the roof frame. A clamp is arranged at the knee joint to lock the knee joint.

Abstract: Rhenium oxide catalysts carried on aluminium silicates, if required with added boric oxide, tungsten oxide, molybdenum oxide or vanadium oxide for the metathesis of olefins and functionalised olefins, in particular of carboxylic acid esters, are provided, whereby the carrier material was hydrothermally treated.

Abstract: The invention relates to a cyanide-free electrolyte being harmless to the environment and to health which makes feasible the production of black surface layers on light metals or on alloys of the latter, preferably titanium, remaining deeply-black and adhesive even after extreme changes in the ambient temperature and having nearly equal values of the optical absorptivity of radiation and of the thermal emission capability (the .alpha./.epsilon.-ratio is about 0.95) by means of the anodic oxidation by spark discharge (ANOF-method). These layers are absolutely X-amorphous and show, hence, an ideal optically isotropic behavior regarding the reflection of radiation. Due to their minimum evolution of gases they offer a high thermovacuum stability. The electrolyte consists of an ammoniacal solution of K.sub.2 H.sub.2 PO.sub.4 potssium dihydrogenphosphate and K.sub.2 CRO.sub.4 potassium chromate. The homogeneity of the optically black layers is ensured by not using fluoride ions and employing acetate ions.