Abstract: The invention relates to a process for the production of di- and polyisocyanates of the diphenylmethane series and mixtures thereof, in which aniline and formaldehyde are reacted in the presence of an acid catalyst to form di- and polyamines of the diphenylmethane series; the di- and polyamines of the diphenylmethane series are phosgenated, optionally in the presence of a solvent, to obtain a crude di- and polyisocyanate; from the crude di- and polyisocyanate, at least one fraction containing at least 5 wt. % 3-ring and multi-ring MDI and at least one fraction containing at least 95 wt. % 2-ring MDI are separated by distillation, and the acidities of the fraction containing at least 5 wt. % 3-ring MDI and multi-ring MDI, and/or the fraction containing at least 95 wt. % 2-ring MDI are determined analytically; and an acidic compound is added to the fraction containing at least 5 wt. % 3-ring MDI and multi-ring MDI, and/or the fraction containing at least 95 wt.

Abstract: The invention relates to a method for generating at least one electrically contactable area on a polymer which is doped with a conductive substance, wherein a contact material is applied onto the polymer, which has a lower specific resistance at 23° C. than the polymer. According to the invention the contact material is applied onto the polymer so tightly that close contact between the contact material and the conductive substance is achieved. Due to the tight application of the contact material, which has a lower specific resistance than the polymer, the input resistance of the doped polymer is effectively reduced. The invention further concerns a formed body made of a polymer which is doped with a conductive substance, which has at least one contactable area, within which a contact material is applied onto the polymer, which has a lower specific resistance at 23° C. than the polymer.

Abstract: A process for preparing a shell-type catalyst which comprises applying to a substantially nonporous inorganic support material having a BET surface area of <80 m2/g, a catalytically active outer shell of a suspension containing at least one water soluble noble metal compound and a substantially water insoluble coating compound, drying the suspension onto the support material, and activating the coated support material in a reducing gas stream.

Abstract: The invention relates to a container 20, 30 for receiving an aqueous solution, which is formed at least partially by an outer limit 21 forming an inner chamber 22, 32 for receiving the solution, and which comprises at least one area which acts as an electrode 25, 26, 33, 34 when an electric voltage is applied and a subsequent discharge occurs, wherein at least one electrode 25, 26, 33, 34 is made of a conductive synthetic material at least based on a plastic material which is doped with at least one conductive substance. A container 20, 30 of the above-mentioned kind is created this way, which is simple and economical to produce and also, for example, enables an efficient transfection of living cells by means of electroporation or an effective electrofusion.

Abstract: The invention relates to a buffer solution for suspending animal or human cells and for dissolving biologically active molecules in order to introduce said biologically active molecules into the cells using an electric current and to a method for introducing biologically active molecules into animal or human cells using an electric current and a buffer solution. The inventive buffer solution has a buffering capacity of at least 20 mmol*I?1*pH?1 and an ionic strength of at least 200 mmol*I?1 during a change to the pH value from pH 7 to pH 8 and at a temperature of 25° C. The use of a buffer solution of this type in the corresponding method allows biologically active molecules to be introduced into animal and human cells with a high degree of transfection efficiency and at the same time a low cell mortality. Different cell types, in particular dormant and actively dividing cells of low activity, can be successfully transfected in said buffer solution.

Abstract: A screwing station, in particular along an assembly line, comprises at least one machine frame and a screwing tool adjustably supported relative thereto between at least one retracted and one operative position and connected to a supply and, optionally, a measuring line. To improve a screwing station of this type in such a way that less mass has to be moved while the screwing station is of a simple construction, so that wear, maintenance work and energy consumption are reduced and a concurrent movement of supply and measuring lines is prevented at the same time, which might otherwise result in damage to the lines, the screwing tool comprises a drive shaft supported on the machine frame and a wrench head telescopically displaceable relative to said shaft, the drive shaft and wrench head being drivingly connected and the wrench head being movable by means of a lifting and lowering means between retracted and operative position.

Abstract: The invention relates to a method for determining the isomer composition in an isocyanate isomer mixture, wherein a spectrum of the isomer mixture is recorded and the spectrum is entered into a chemometric calibration model.

Abstract: According to the invention, a power characteristic information concerning a power characteristic profile of a target terminal is transmitted to a base terminal, before transferring signaling of a connection set up from a base terminal to a target terminal. As a result of the connection set up signaling, a power characteristic request is transferred based on the power characteristic information.

Abstract: A sliding bearing for axial and/or radial arrangement of a first bearing member in relation to a second bearing member, comprises a second bearing member, which has a bearing recess provided with a second slide face; a first bearing member, which is lodged in the bearing recess and which is mounted axially and/or radially, the first bearing member having a first slide face, which is opposite the second slide face and spaced therefrom by a clearance; at least one sliding/guiding element, which is disposed between the first and the second bearing members and fixed in relation to one bearing member, for guidance of a motion of the first relative to the second bearing member; an equalizing compound, which is disposed between the at least one sliding/guiding element and the bearing member relative to which is fixed the at least one sliding/guiding element, for adaptation of the guide clearance between the at least one sliding/guiding element and the slide face that is displaceable in relation thereto, the equalizi

Abstract: The invention relates to a novel circuit arrangement for electrotransfection or electrofusion, which enables the transportation of DNA and/or other biologically active molecules to the nucleus of higher eukaryotic cells or the fusion of cells, independent of cell division and with reduced cell mortality.

Abstract: An adjustable-length actuating element comprises an energy storing device. A casing and a piston rod, which is displaceable in the casing, are provided within the actuating element. A spindle drive is integrated in the energy storing device. A driving shaft is in rotary driving connection with the piston rod.

Abstract: Polyisocyanates of the diphenylmethane series are produced by a) reacting aniline and formaldehyde in the presence of an acidic catalyst to produce a polyamine, b) neutralizing the reaction mixture from step a) with a base at a temperature of more than 110° C. or neutralizing the reaction mixture from step a) with a base and heating the neutralized mixture to a temperature of more than 110° C., and c) phosgenating the polyamine from step b) to convert it to the corresponding polyisocyanate.

Abstract: The invention relates to a process for the preparation of polyamines of the diphenylmethane series, comprising

Abstract: The present invention concerns a process for the production of methylenedianiline (MDA) having a high monomer content.

Abstract: The invention relates to a method for continuously or discontinuously producing tetrahydrofuran polymers by homopolymerization of tetrahydrofuran, alkyl-substituted tetrahydrofurans and/or alkylene oxides in the presence of carboxylic acid anhydrides or compounds containing reactive hydrogen using an optionally non-acidified or acid-activated calcined and granular natural amorphous aluminum silicate catalyst. The inventive method provides a means for substantially suppressing the formation of cyclic ethers and for obtaining a polymer with a narrow molecular weight distribution by keeping the concentration of carboxylic acid anhydrides or alkylene oxide constantly below 1 wt. % during polymerization. The catalysts have a long life span and lead to polymers that are characterized by highly uniform properties and a narrow molecular weight distribution even if a fairly impure monomer is used.

Abstract: Polyisocyanates of the diphenylmethane series are produced by a) reacting aniline and formaldehyde in the presence of an acidic catalyst to produce a polyamine, b) neutralizing the reaction mixture from step a) with a base at a temperature of more than 110° C. or neutralizing the reaction mixture from step a) with a base and heating the neutralized mixture to a temperature of more than 110° C., and c) phosgenating the polyamine from step b) to convert it to the corresponding polyisocyanate.

Abstract: A thermoplastic trim strip is mounted to an edge face of a wood-core furniture panel by applying a face of the trim strip directly to the edge face and bonding the trim-strip face directly to the panel-edge face. The panel has outer faces terminating at the edge face and the trim strip is provided with edge lips that project past the broad faces when the strip is bonded to the edge face. The edge lips are melted over onto the panel faces and trimmed off where they project past the panel faces. A thin layer of glue can be applied between a face of the trim strip and the edge face and the trim-strip face is bonded to the panel-edge face by means of the glue layer.

Abstract: The inventive paint dryer, comprises a cabin (12) for housing objects (15) that are to be painted and dried. At least one fresh air supply (8) is provided in order to introduce fresh air into an air circulation system pertaining to the dryer (1) resulting in the circulation of said air. At least one pure gas supply line (7) is provided, wherein thermally cleaned and heated waste air is introduced as a pure gas, thereby maintaining the waste gas circulated in the circulation system at the desired temperature in such a way that objects (15) arranged in the cabin (12) can be dried by radiation and/or convection. The pure gas supply line (7) is surrounded by the fresh air supply line (8) at least along a longitudinal pipe segment and at least in said longitudinal pipe section the pure gas supply pipe (7) is constructed in such a way as to allow for the transmission of heat to fresh air flowing into the fresh air supply (8).

Abstract: A process for preparing a shell-type catalyst which comprises applying to a substantially nonporous inorganic support material having a BET surface area of <80 m2/g, a catalytically active outer shell of a suspension containing at least one water soluble noble metal compound and a substantially water insoluble coating compound, drying the suspension onto the support material, and activating the coated support material in a reducing gas stream.

Abstract: An improved process for the preparation of polytetramethylene ether glycol diesters of the formula R—CO—O(—CH2-CH2-CH2-CH2-O)n-COR1 in which R and R1 are identical or different and are an alkyl radical or a derivative thereof, by polymerization of tetrahydrofuran in the presence of a fixed-bed polymerization catalyst and a carboxylic acid anhydride. Through use of neutral or weakly basic magnesium-aluminium hydrosilicates instead of the known acidic montmorillonite, zeolite or kaolin catalysts, polymers with more uniform properties and a narrower molecular weight distribution are obtained at a higher rate of polymerization, even when technical-grade tetrahydrofuran is used.