Compounds having acidic protons and a molecular structure which can delocalize the electron density of the conjugate base (target compounds) are chlorinated by contacting such compounds with a perchloroalkane and aqueous base in the presence of a phase transfer catalyst which is an tetraalkylammonium hydroxide. Chlorinated products, preferably gem-dichloro compounds, are produced. The gem-dichloro compounds are useful for alkylation of aromatic compounds. For instance fluorene is chlorinated to ...

Imidazole compounds of the formula I ##STR1## in which R.sup.1 =alkyl, R.sup.2 and R.sup.3 =H, halogen or alkyl, X=OH or an amide radical having certain substituents, processes for their preparation and pharmaceuticals based on these compounds, in particular for the prophylaxis and treatment of circulatory disturbances, especially of disturbances of the microcirculation and of the disorders resulting therefrom, and some novel intermediates for the preparation of the compounds of the formula I, w...

A method of automatically ordering the presentation of documents clusters generated from a ranked corpus of documents. First, the corpus is ordered into a plurality of clusters. Next, a rank is determined for each cluster based upon the rank of a document within that cluster. Afterward, the clusters are presented to a computer user in the order determined by their rank.

A method of improving the compression ratio of image data in the form of foreground data printed over background data by arranging both kinds of data pixels into 8 by 8 pixel blocks. All blocks that do not contain at least one pixel to be printed are deleted before compression. The deleted blocks will be entirely background pixels that will be overlaid by foreground pixels, or entirely foreground pixels that will not be printed because they are located outside of foreground masks.

A compound of general formula I ##STR1## in which the 2-3 bond in ring C could be double or single bond. Ring B and its substituents may be attached at position 2 (at J) in ring C. The key feature in the modifications is that the prenylation must not cyclize through the free OH groups(s) at ortho position to the prenylation. Atoms attached at X in ring C may be S or N or P or C or O or pharmaceutically acceptable metal or CH.sub.2. Atoms attached to Y could be S or N or P or O or alkyl (C.sub.1 ...

Disclosed is a fiber optic device of the type having a plurality of light-conducting optical fibers secured together in side-by-side relation so that corresponding opposite ends of the fibers cooperate to define first and second faces. Some of the fibers have a single cladding of light absorbing material, the remainder of the fibers having a single cladding of non-absorbing material. The combined effect of this combination of fibers results in image transfer devices capable of transferring an im...

A process for preparing substantially completely cyclized aromatic polyimides, either monomeric, oligomeric or polymeric, is provided. The process involved the reaction of a mixture of at least one tetracarboxylic acid dianhydride, at least one aromatic diamine and an .alpha.,.beta.-carboxylic acid monoanhydride in at least one aromatic phenol, preferably cresols, in the presence of an organic azeotroping agent such as a cyclic hydrocarbon, preferably benzene, until substantially all of the wate...

A colour-separating prism arrangement having surfaces which adjoin dichroic layers of mutually different colors with either the lower limit of the second dichroic layer which reflects the red light being substantially equal to the upper limit of the first dichroic layer, or the upper limit of the second dichroic layer which reflects the blue light being substantially equal to the lower limit of the first dichroic layer.

Imidazole compounds of the formula I ##STR1## in which R.sup.1 =alkyl, R.sup.2 and R.sup.3 =H, halogen or alkyl, X=OH or an amide radical having certain substituents, processes for their preparation and pharmaceuticals based on these compounds, in particular for the prophylaxis and treatment of circulatory disturbances, especially of disturbances of the microcirculation and of the disorders resulting therefrom, and some novel intermediates for the preparation of the compounds of the formula I, w...

An electronic control apparatus for use in vehicles comprised of two, one-chip microcomputers. The microcomputers each have a ROM and a RAM and are used to control different systems provided in the vehicle. The ROM of the second microcomputer stores an operational program which can be used to calculate control values for controlling various types of devices. It also stores operational map data which can be used to calculate control values for controlling various types of devices. Various signals...