Abstract: Molecular sieves are modified by an ion exchange process where metal cations are introduced into the molecular sieves by means of solid state ion exchange. The solid state ion exchange can be carried out as follows: a weighed amount of calcined and activated zeolite is intimately mixed with a precalculated amount of PtCl.sub.2, PdCl.sub.2, RhCl.sub.3, CuCl.sub.2, V.sub.2 O.sub.5 or another compound of the noble metals (e.g., corresponding halides or oxides), the solids mixture is then heated in a current of inert gas (e.g., a current of helium gas or of nitrogen) to temperatures of 400.degree. to 600.degree. C., then cooled down to room temperature and subsequently reduced in a current of hydrogen for 10 to 14 hours at 280.degree. to 350.degree. C. in order to produce small metal clusters from the cationically introduced metal.

Abstract: A process is described for defined impregnation of honeycomb structures and a device for performing the process. The impregnating solutions are sprayed directly into the flow channels in the honeycomb structure using hollow injector needles.

Abstract: Novel N-acyl depeptides of the formula:R.sup.2 --NH--CHR.sup.1 --CO--ASin which AS, R.sup.1 and R.sup.2 have certain, more precisely defined meanings. These N-acyl dipeptides are more stable under conditions of sterilization (121.degree. C.) than corresponding, non-acylated dipeptides. On the other hand, they are cleaved more rapidly and more completely at the peptide bond in the living organism than the cleavage of the acyl group from simple N-acyl amino acids takes place. They can therefore be used with advantage as a source for the carbon terminal amino acid in mixtures and solutions for artificial nutrition or in culture media for cell cultures.

Abstract: Shaped, activated Raney metal fixed-bed catalysts are obtained by molding a powder of at least one catalyst alloy, comprising at least one Raney process metal as catalytically active component and a leachable alloy component, and a powder of pure Raney process metal as binder with the addition of a shaping aid and pore-producer and subsequent calcination at temperatures below 850.degree. C. During calcination the shaping aid and pore-producer are burned away. Catalyst alloy powder and binder powder thereby sinter together to give a mechanically stable and porous molded item. This molded item thus consists of particles of catalyst alloys which are bonded by the powder of pure Raney process metal. It has no catalytically inactive, ceramic or glassy binder. The surface layer of the molded item is activated by leaching the leachable alloy component contained in the catalyst alloys with caustic soda solution.

Abstract: Halogen thiophene carboxylic acid derivatives of the General Formula ##STR1## in which Hal signifies chlorine or bromine, n the number 2 or 3, * signifies either an enantiomer or a racemate in the case of different R.sup.2 and R.sup.3 groups,R.sup.1 stands for hydrogen or an alkyl group,R.sup.2 stands for hydrogen, an alkyl group which can optionally be substituted by hydroxy-, carboxy-, alkoxy- or alkoxycarbonyl, mercapto- or alkylmercapto- or benzylmercapto, for an aryl group or aralkyl group, wherein the ring system can optionally be substituted with fluorine, chlorine or bromine atoms, for a cycloalkyl group or a cycloalkyl-methyl group,R.sup.3 stands for hydrogen, an alkyl group, an alkenyl or alkynyl group or, optionally, R.sup.1 and R.sup.3 or R.sup.2 and R.sup.3 together can form an alkylene bridge in which one CH.sup.2 unit can optionally be substituted by NR.sup.1, O or S,Y signifies OH, OR.sup.4 or NR.sup.5 R.sup.6,in whichR.sup.

Abstract: A method is shown for the separation of catalyst-free working solution from working solution, containing noble-metal black, especially palladium black as catalyst, of the hydrogenation cycle of the so-called anthraquinone method for the production of hydrogen peroxide by filtration of the catalyst-containing working solution using filter candles. The filter candles are formed of an open-pore support body based on a carbon material or metallic or ceramic material with an average pore width in a range of 5 to 100 .mu.m and of a single-layer or multi-layer membrane of ceramic material with an average pore width in a range of at least about 1 up to 10 .mu.m located on the outside surface of the support body.

Abstract: Novel a-acyl dipeptides of the formula:R.sup.2 --NH--CHR.sup.1 --O--ASin which AS, R.sup.1 and R.sup.2 have certain, more precisely defined meanings. These N-acyl dipeptides are more stable under conditions of sterilization (121.degree. C.) than corresponding, non-acylated dipeptides. On the other hand, they are cleaved more rapidly and more completely at the peptide bond in the living organism than the cleavage of the acyl group from simple N-acyl amino acids takes place. They can therefore be used with advantage as a source for the carbon terminal amino acid in mixtures and solutions for artificial nutrition or in culture media for cell cultures.

Abstract: In order to produce bright to brilliant, leveled copper-tin alloy coatings, galvanic baths are used which contain 1 to 60 g/l copper in the form of copper(I) cyanide, 1 to 50 g/l tin in the form of alkali stannate, 0 to 10 g/l zinc in the form of zinc cyanide, 1 to 200 g/l of one or several complex binders (e.g., oligosaccharides and/or polysaccharides), 1 to 100 g/l free alkali metal cyanide, 1 to 50 g/l free alkali metal hydroxide, 0 to 50 g/l alkali metal carbonate 0.01 to 5 g/l brightener (e.g., alkene sulfonate, alkyne sulfonate, pyridine compounds or sulfur-containing propane sulfonates) and 0 to 100 mg/l lead as lead(II) acetate or lead(II) sulfonate.

Abstract: Cadmium-free brazing solders with working temperatures under 630.degree. C. containing 45 to 80 wt. % silver, 14 to 25 wt. % copper 10 to 25 wt. % gallium, 1 to 7 wt. % zinc and 0 to 5 wt. % indium and/or tin. The alloys have good cold workability and ductility.

Abstract: Molecular sieves are modified by an ion exchange process where metal cations are introduced into the molecular sieves by means of solid state ion exchange. The solid state ion exchange can be carried out as follows: a weighed amount of calcined and activated zeolite is intimately mixed with a precalculated amount of PtCl.sub.2, PdCl.sub.2, RhCl.sub.3, CuCl.sub.2, V.sub.2 O.sub.5 or another compound of the noble metals (e.g., corresponding halides or oxides), the solids mixture is then heated in a current of inert gas (e.g., a current of helium gas or of nitrogen) to temperatures of 400.degree. to 600.degree. C., then cooled down to room temperature and subsequently reduced in a current of hydrogen for 10 to 14 hours at 280.degree. to 350.degree. C. in order to produce small metal clusters from the cationically introduced metal.

Abstract: A process for the isolation of L-leucine and L-isoleucine from an aqueous solution containing these amino acids and their separation from each other by contacting the solution with a zeolite under acid conditions.

Abstract: A catalyst includes or consists essentially of the oxides of silicon, aluminum and titanium, characterized in that the catalyst particles are built up from a core with the composition (SiO.sub.2).sub.y (AlO.sub.2).sub.y M.sub.y, wherein x/y=10 to .infin. and M=H, Na, K, NH.sub.4, or NR.sub.4, wherein R is a C.sub.1-8 -alkyl, and a shell with the composition (SiO.sub.2).sub.n (TiO.sub.2).sub.m, wherein n/m=12 to 1000. Both the core and the shell have a crystal structure of MFI or MEL. The catalyst can be prepared by preparing a synthesis gel for the preparation of a titanium silicalite, thereafter introducing an aluminosilicate of the MFI or MEL structural type into this synthesis gel, and working up the synthesis gel in a known manner to obtain the product.

Abstract: A method is disclosed for the semi-continuous melting of ceramic material by means of inductive melting in high-frequency and medium-frequency induction melting furnaces whose melting coil surrounds a sintering crust crucible and contains a run-out channel. In the method, melt is periodically run out and material to be melted is supplied to the crucible so as to replace the material removed preferably so as to maintain a constant level. An intensively cooled channel is used as a run-out device. For the melt broaching, the melt nose is grasped from below by way of an automatically controllable broaching lance of a broaching device and raised. The broaching lance is then advanced between the bottom of the channel and the solidified melt until the sintering crust is pierced. The method permits a reliable and economic management of the process and the maintenance of the quality of the melted products.

Abstract: Hard and scratch-proof objects of platinum and palladium or their alloys comprise a boron-containing surface layer which is 20 to 500 .mu.m thick and contains 0.3 to 1.5% by weight boron embedded in the metal lattice.

Abstract: A polymerizable (meth)acrylate system which can be cured at ambient temperature to provide a conductive floor coating or shaped article. The composition comprises (meth)acrylates and optionally other monomers and other components such as pre-polymers, plasticizers, customary additives etc., in combination with amorphous or spheroidal graphite and/or carbon fibers and/or finely divided metal. Other fillers may be added. In particular, amorphous natural graphite, preferably having the particle size 20 to 1000 .mu.m, is suitable. Coatings prepared in this way fulfill the requirements in respect of DIN 51 953.

Abstract: The invention relates to novel microorganisms, their use and method of producing L-.alpha.-amino acids. In particular, microorganisms DSM 7329 and 7330 are suitable for the production of L-.alpha.-amino acids from corresponding hydantoins or carbamoyl-.alpha.-amino acids. These novel microorganisms are simple to cultivate and make possible high L-.alpha.-amino acid yields from different substrates.

Abstract: A process for applying a coating to honeycomb structures in an exhaust gas converter which contains two such honeycomb structures in a common housing or enveloping tube which are arranged one after the other and which are separated from each other by a gap. The coating dispersion is first supplied from one end of the exhaust gas converter up to the gap between the two honeycomb structures. Then excess coating dispersion is driven out using a blast of air from the direction of the uncoated honeycomb structure. To coat the second honeycomb structure, the exhaust gas converter is inverted and the coating dispersion is then applied in the same way but from the uncoated end. Following the dispersion coating procedure, production of the catalyst is completed by drying and optionally calcining.

Abstract: The invention relates to a transposon consisting of a fragment of the R plasmid pCxM82B from Corynebacterium xerosis DSM 5021, to mobilizable, non-self-transferrable vectors which contain this transposon, and to methods for the mutagenesis of gram-positive bacteria by means of the transfer of these vectors and the generation of auxotrophic mutants.

Abstract: A modified supported noble metal catalyst is disclosed for the selective hydrogenation of aromatic halonitro compounds to form aromatic haloamines. The support consists of active carbon. The active component is platinum modified with copper. The new catalyst is distinguished by good selectivity and a high yield.

Abstract: Storage stability of finely divided sodium percarbonate is improved by melt-coating of water-insoluble encapsulation agents.