Abstract: The invention relates to pigments consisting of substantially spherical particles with a mean particle diameter of less than 10 .mu.m, on the basis of an oxidic or silicate substrate material with noble metal distributed extremely finely on and/or in the particles. Preferred pigments are purple-colored and are based on an oxide from the series SiO.sub.2, SnO.sub.2 and ZrO.sub.2 and gold as noble metal. The pigments are suitable for the production of ceramic decorations and for the dyeing of plastics, synthetic films and fibers as well as lacquers. Exceptional application properties are obtained by virtue of the spherical shape. The pigments are obtainable by a spray-pyrolysis process in which an aerosol consisting of a solution of at least one noble metal compound and an oxide- or silicate-forming precursor is subjected to pyrolysis; the pigment is separated from the pyrolysis gas.

Abstract: An electrolysis cell with a fixed-bed electrode and its use for the purification of waste gases. The electrolysis cell includes a fixed-bed electrode, a counterelectrode which is separated from it and designed as a gas diffusion electrode, devices for the supply and flow-off of an electrolyte as well as for the inlet and outlet of the gas to be purified and a space associated with the counterelectrode with devices for the supply and the removal of a gas. In order to purify gas the fixed-bed electrode is operated as a trickle bed and the gas to be purified flows in cocurrent or countercurrent flow to the electrolyte. In reductive purification hydrogen is supplied to the gas diffusion electrode and in oxidative purification oxygen is used.

Abstract: A platinum/ruthenium alloy catalyst that includes finely dispersed alloy particles on a powdery, electrically conductive carrier material. The catalyst is particularly resistant to carbon monoxide poisoning when the alloy particles display mean crystallite sizes of 0.5 to less than 2 nm.

Abstract: Pyrogenic oxides having a BET surface area of between 30 and 150 m.sup.2 /g have a viscosity of less than 2,500 mPas in an aqueous suspension. They are prepared by setting the hydrogen ratio gamma and the oxygen ratio lambda to less than one in a high-temperature flame hydrolysis. The pyrogenic oxides are employed in the CMP application in the electronics industry.

Abstract: The invention relates to an improved method for the production of 2,3,5-trimethylhydroquinone by rearranging 4-oxo-isophorone (keto-isophorone, 3,5,5-trimethylcyclohex-2-en[e]-1,4-dione) to a trimethylhydroquinone diester and by its subsequent saponification.

Abstract: Compounds of Formula I, and their N-oxides and agriculturally suitable salts, are disclosed which are useful for controlling undesired vegetation ##STR1## wherein X, Y, J, R.sup.1, and R.sup.2 are as defined in the disclosure. Also disclosed are compositions containing the compounds of Formula I and a method for controlling undesired vegetation which involves contacting the vegetation or its environment with an effective amount of a compound of Formula I.

Abstract: Acrolein polymer from acrolein and one or more polyhydric alcohols, characterized by release of monomeric acrolein in aqueous systems and hence by a prolonged effect on microorganisms, is prepared by adding acrolein to a reaction medium containing catalyst in dissolved form, and not allowing the temperature of the reaction medium to rise about 50.degree. C. The acrolein polymer may be used in aqueous systems as a biocide.

Abstract: A process for preparing catalytically active coatings for the synthesis of hydrogen cyanide on moulded items substantially consisting of aluminum oxide. The catalytically active coatings contain, as active components, at least one platinum group metal and a nitride waich are applied to the moulded item by means of a coating dispersion which contains the active components as finely divided solids. This means that the hitherto conventional production of aluminum nitride during the forming process is not required. The coatings therefore achieve their final activity level, which is well above that of conventional coatings, very rapidly. In addition, these catalysts can be started up under high load and have a lower operating temperature.

Abstract: Surface-modified, pyrogenically produced mixed oxides which contain two or more components of the series SiO.sub.2, Al.sub.2 O.sub.3, TiO.sub.2, ZrO.sub.2, Fe.sub.2 O.sub.3, Nb.sub.2 O.sub.5, V.sub.2 O.sub.5, WO.sub.3, SnO.sub.2, GeO.sub.2 and have been surface-modified with one to several compounds of the following groups:(a) organosilanes of the type (RO).sub.3 Si(C.sub.n H.sub.2n+1),(b) R'.sub.x (RO).sub.y Si(C.sub.n H.sub.2n+1),(c) X.sub.3 Si(C.sub.n H.sub.2n+1),(d) X.sub.2 (R')Si(C.sub.n H.sub.2n+1),(e) X(R').sub.2 Si(C.sub.n H.sub.2n+1),(f) (RO).sub.3 Si(CH.sub.2).sub.m --R',(g) (R").sub.x (RO).sub.y Si(CH.sub.2).sub.m --R',(h) X.sub.3 Si(CH.sub.2).sub.m --R',(i) (R)X.sub.2 Si(CH.sub.2).sub.m --R',(j) (R).sub.2 X Si(CH.sub.2).sub.m --R',(k) Silazanes of the type ##STR1## (l) Cyclic polysiloxanes, (m) Polysiloxanes or silicone oils.

Abstract: The invention relates to a new process for the preparation of optically active amino acids and amino acid derivatives of the general formula (I), wherein *, X and R.sup.1 to R.sup.4 have the meaning given in the description. Starting from commercially obtainable (-)-menthol or (+)-menthol, the enantiomerically pure compounds of the formula (I) are obtained in high yields. The method is particularly suitable for the preparation of sterically demanding amino acids and amino acid derivatives.

Abstract: The present invention relates to a process for the production of five-membered or six-membered cyclic ethers, in particular of anhydropolyols, by acid-catalysed cyclodehydration of polyols that contain at least two hydroxyl groups with a spacing enabling ring formation--that is to say, preferably with a spacing of 4 or 5 C atoms. The invention is directed in particular towards the production of anhydrotetritols, anhydropentitols and, particularly preferred, anhydrohexitols, from tetritols, pentitols and hexitols, respectively.

Abstract: With a view to increasing the lifespan of metallic dental components as regards fatigue fractures, compressive stresses are introduced into the surface layer of these components, such as by means of shot-peening.

Abstract: A platinum supported catalyst is disclosed for the anode in a PEM fuel cell with high resistance to poisoning by carbon monoxide. The catalyst contains the noble metals platinum and ruthenium on a finely divided, conductive support material. The two noble metals are not alloyed with each other and are present in highly dispersed form on the support material, wherein the crystallite size of the platinum is less than 2 nm and that of the ruthenium is less than 1 nm.

Abstract: A method for obtaining 2-hydroxy-4-methylthiobutyric acid (methionine-hydroxy analog, MHA) in primarily free form which is stable in storage by distilling a product solution containing MHA and by producing MHA product mixtures with improved storage stability from such a distillate. The distillate can be produced directly starting from MHA raw products from any MHA production process, which can optionally also contain solvent or water. The starting material may also be a commercial MHA product.

Abstract: A method of producing 3,5,5-trimethylcyclohexa-3-ene-1-one (.beta.-isophorone) including a catalyst of an oxide or mixed oxide of at least one element of the groups IIa, VIII, Ib, IIIa and Va of the periodic system. Isomerization is carried out without the addition of an organic base. The space-time yield in the production of .beta.-isophorone by the isomerization of .alpha.-isophorone is at a level suitable for an industrial application. .beta.-isophorone is especially suitable as an intermediate product for producing ketoisophorone.

Abstract: Problems encountered when discharging bulk containers using a blow-through rotary valve can be avoided by the discharge device, according to the invention, in which a vent connection of the rotary valve is in connection with the internal chamber of the container through a filter hose open on both ends.

Abstract: A process for the preparation of methionine or a salt of methionine by reaction of the components 3-methylmercaptopropionaldhyde, hydrogen cyanide, ammonia and carbon dioxide or components from which the above-mentioned components can be prepared, optionally in the presence of water, to 5-(2-methylmercaptoethyl)-hydantoin and further reaction thereof to methionine or the salt thereof, characterised in that the reaction of the components is initiated by means of at least one premixture in such a way that a first mixture is formed containing at least the predominant proportion (at least 5/10) of the 3-methylmercaptopropionaldeyde and at least 1/10 of the hydrogen cyanide component or corresponding quantities of components from which these components can be prepared, and less than 5/10 of one of the components ammonia, carbon dioxide or of the components from which ammonia or carbon dioxide can be prepared, and in that this first mixture is combined with the other component(s) for the reactive conversion to 5-(2

Abstract: Sintered silver-iron material for electrical contacts, with properties comparable with those of silver-nickel materials, is obtained by using iron powder having more than 0.25% carbon by weight and microhardness higher than 200 HV 0.025 and sintering in a hydrogen-free protective gas.

Abstract: A plant peptide amidase from the flavedo of oranges is known; this can be obtained only in small quantities and is seasonal. The proposed new enzymes are microbial peptide amidases which can be obtained from micro-organisms recovered from soil samples in a "double screening" and grown. These microbial peptide amidases are particularly useful for (a) the production of peptides and N-terminal-protected amino acids, (b) racemate splitting of N-protected amino acid amides, (c) obtaining non-proteinogenous D-amino acids, and (d) obtaining new N.sub..alpha. -protected D-amino acid amides.

Abstract: It is known to isolate MHA from a reaction mixture obtained by the addition of hydrocyanic acid (HCN) to methyl mercaptopropionic aldehyde (MMP) and the hydrolysis of the methyl mercapto propionic aldehyde cyanohydrine (MMP-CH) obtained thereby with sulphuric acid, in which the reaction mixture is brought into contact with a substantially non-water-miscible organic solvent, in order to form an extraction solution having the solvent and MHA transferred from the reaction mixture, and the MHA is obtained as an extract from this extraction solution by concentration. The simplest and most economical process of the invention concerning the processing of the reaction product which facilitates the production of a highly concentrated product with an extremely low dimer, oligomer and by-product content, is characterised in that the concentration is conducted in such a way that the remaining extract contains less than 4 wt % and preferably less than 2 wt % of water.