Abstract: A process and a system are proposed for short-time arc welding elements, such as for example metal studs, on to components, such as for example metal sheets, wherein an element in the context of a welding operation is initially raised in relation to the component, a welding arc is formed between the element and the component, and the element is lowered again, the lifting height of the element in relation to the component being detected at least within a time segment between raising and lowering of the element. The initiation of the lowering operation and/or the lowering operation itself is controlled as a factor of the detected lifting height such that a previously specified total welding time is achieved.

Abstract: Compounds of the general formula (I) where: R1, R2 are each independently a) H b) -M1-A1-R5 c) a straight-chain or branched alkyl radical having from 1 to 16 carbon atoms or a straight-chain or branched alkenyl radical having from 2 to 16 carbon atoms, where c1) one or more nonadjacent and nonterminal CH2 groups may be replaced by —O—, —C(?O)O—, —O—C(?O)—, —O—C(?O)—O—, —C(?O)— or —Si(CH3)2—, and/or c2) one CH2 group may be replaced by —C?C—, cyclopropane-1,2-diyl, cyclobutane-1,3-diyl, cyclohexane-1,4-diyl or phenylene-1,4-diyl, and/or c3) one or more hydrogen atoms may be replaced by F and/or Cl, p, q are each independently 0 or 1 G1-G2 is —CH2CH—, —CH?C—, —CH2CH2CH— or —CH?CH—CH— M1 is —CO—O—, —O—CO—, —CH2—O—, —O—CH2—, —CF2—O—, —O—CF2—, —CH?CH—, —CF?CF—, —C?C—, —CH2—CH2—CO—O—, —O—CO—CH2—CH2—, —CH2—CH2—, —CF2—CF2—, —(CH2)4—, —OC(?O)CF?CF— or a single bond, A1 is 1,4-phenylene where one or two hydrogen atoms may be replaced by F, Cl, CN and/or OCF3, or up to three hydrogen atoms may be replaced by

Abstract: The invention relates to fluorinated aromatics of the formula (I) where X is CH2, C?O, CF2, O or S, Y is H or F, with the proviso that Y has to be F when X is CH2, and where the other parameters are as defined in claim 1, and also to their use in liquid-crystal mixtures, and also to liquid-crystal mixtures comprising these compounds and to liquid-crystal displays comprising these mixtures.

Abstract: Compounds of the formula (I) in which the parameters are as defined herein, are suitable for use in liquid-crystal media and liquid-crystal displays which contain these media.

Abstract: A process and a system are proposed for short-time arc welding, in particular for stud welding, with the step of sampling a welding parameter, in particular the arc voltage (U), during at least one time segment (Ts) of the welding operation, in order to detect disturbances, wherein the measurement curve determined from the sampling operation is smoothed and subsequently wherein at least one tolerance curve is generated which lies at a previously adjustable distance from the smoothed measurement curve, and subsequently the unsmoothed measurement curve is compared with the tolerance curve in order to detect high-frequency disturbances.

Abstract: Liquid crystal mixture comprising one or several compounds of formula (I) (I) wherein R1, R2, R3, R4, R5, R6, M1, M2, X, A, and m are defined herein.

Abstract: Concerning the compound of the formula (I) R1, R3 are each independently, for example, H R2, R4 are each independently, for example, H X1, X2 are each independently H or F M1 is —CO—O—, —O—CO—, —CH2—O—, —O—CH2—, —CF2—O—, —O—CF2—, —CH?CH—, —CF?CF—, —C?C—, —CH2—CH2—CO—O—, —O—CO—CH2—CH2—, —CH2—CH2—, —CF2—CF2—, —(CH2)4—, —OC(?O)CF?CF— or a single bond A1 is, for example, 1,4-phenylene, and R5 has the same possible definitions as specified for R2 and R4, with the exception of -M1-A1-R5, but independently of the particular definitions of R2 and R4 with the following provisos: 1) at least one of X1, X2 has to be F 2) R1, R2, R3 and R4 must not at the same time be H 3) at most two of R1, R2, R3 and R4 may be c).

Abstract: In the compound of the formula (I), where: R1, R2 are each independently, for example, H or a straight-chain or branched alkyl radical p, q are each independently 0 or 1, i.e. at the value zero, —H is present at the appropriate position instead of —F M1 is —CO—O—, —O—CO—, —CH2—O—, —O—CH2—, —CF2—O—, —O—CF2—, —CH?CH—, —CF?CF—, —C?C—, —CH2—CH2—CO——O—,—O—CO—CH2—CH2—, —CH2—CH2—, —CF2—CF2—, —(CH2)4—, —OC(?O)CF?CF— or a single bond A1 is, for example, 1,4-phenylene R5 has the same possible definitions as specified for R1 and R2, with the exception of -M1-A1-R5, but independently of the definition of R1 and R2 X is H, F, OF3, CF3, OCF2H with the following provisos: a) at least one of p, q has to be 1 b) R1 and R2 must not at the same time be H c) R2 and X must not at the same time be H.

Abstract: Compounds of the formula (I) in which R1, R2, p, q, G and X are each as defined in the description, use of compounds of the formula (I) in liquid-crystal mixtures, liquid-crystal mixture comprising one or more compounds of the formula (I), and a liquid-crystal display comprising an inventive liquid-crystal mixture.

Abstract: Compounds of the formula (I) are described in which M1 is, for example, —CO—O— or a single bond A1 is, for example, 1,4-phenylene, R5 has the same possible definitions specified for R1, with the exception of -M1-A1-R5, but independently of the definition of R1 G1-G2 is CH2CH2, CH?CH, CF2CF2, CF?CF, CF?CH, CH?CF X1, X2, X3, X4, X5 are each independently H or F R1, Y1, Y2 are each independently a) H b) F where Y1, R1, (R1 and Y1) or (R1 and Y2) may also have the definitions c) and/or d), but only in each case not more than one of (R1 and Y1) and of (R1 and Y2) may have the definition d) c) is, for example, a straight-chain or branched alkyl radical having from 1 to 16 carbon atoms or a straight-chain or branched alkenyl radical having from 2 to 16 carbon atoms, d) -M1-A1-R5 with the following provisos: a) at least one of X1, X2, X3, X4, X5, G1-G2 is or contains F b1) when at least one of Y1 and X1 is F and/or G1-G2 contains F, it is possible for R1, X2, X3, X4 not to be F b2) when at least one

Abstract: A compound of the formula (I) is described where: R1 is a) H b) a straight-chain or branched alkyl radical having from 1 to 16 carbon atoms or a straight-chain or branched alkenyl radical having from 2 to 16 carbon atoms, in which b1) one or more nonadjacent and nonterminal CH2 groups may be replaced by —O—, —C(?O)O—, —O—C(?O)—, —O—C(?O)—O—, —C(?O)— or —Si(CH3)2— and/or b2) one CH2 group may be replaced by —C?C—, cyclopropane-1,2-diyl, cyclobutane-1,3-diyl, cyclohexane-1,4-diyl or phenylene-1,4-diyl and/or b3) one or more hydrogen atoms may be replaced by F and/or Cl c) -M1-A1-R5 R2 has the same possible definitions as specified for R1, with the exception of H, but independently of the definition of R1 and R5 R5 has the same possible definitions as specified for R1, with the exception of -M1-A1-R5, but independently of the definition of R1 and R3 M1 is —CO—O—, —O—CO—, —CH2—O—, —O—CH2—, —CF2—O—, —O—CF2—, —CH?CH—, —CF?CF—, —C?C—, —CH2—CH2—CO—O—, —O—CO—CH2—CH2—, —CH2—CH2—, —CF2—CF2—, —(CH2)4—, —OC(?

Abstract: The invention relates to materials which are stable at high temperatures and which have high specific surfaces. Said materials are produced by heating them to a temperature in a matrix above the later temperature at which they are used, e.g. aluminum oxide or zirconium oxide. The temperature of the specific surfaces thereof, after relatively long tempering, is 1100° C. or 1000° C., even above 50 m2/g or 10 m2/g. Carrier catalysts can be also be produced according to said method.

Abstract: Liquid crystal mixture comprising compounds of formula (I) wherein R1: is H or a linear or branched alkyl group or branched alkenyl group R2: stands for a) H or F b) a linear or branched alkyl group or a linear or branched alkenyl group c) a radical wherein R3, R4, R5, R6: are an alkyl group M1, M2: represent independently from another a single bond, —OC(?O), —C(?O)O—, —OCH2—, —NH— A: is a) a linear or branched alkan-?,?-diylgroup or alkene-?,?-diyl group b) the group —C(?Y)— wherein Y is CH-Z with Z being phenylen-1,4-diyl, optionally substituted by one to three halogenatoms, alkyl or alkyloxy groups, c) the group —CHY wherein Y is CH2-Z with Z being phenylen-1,4-diyl, optionally substituted by one to three halogenatoms, alkyl or alkyloxy groups d) a group wherein p, q are 0, 1 or 2; M3 is a single bond or —OC(?O)—, —C(?O)O—, —OCH2—, —CH2O—, —C?C—, —CH2CH2—, —CH2CH2CH2CH2— the radicals are phenylen-1,4-diyl, X is H, OH, a linear or branched alkyl or alkyloxy group, m: is 0 or 1 X and M1-(A

Abstract: Compounds of the formula (I) where: R1, R2 are each independently a) H b) -M1-A1-R5 c) a straight-chain or branched alkyl radical having from 1 to 16 carbon atoms or a straight-chain or branched alkenyl radical having from 2 to 16 carbon atoms, where c1) one or more nonadjacent and nonterminal CH2 groups may be replaced by —O—, —C(?O)O—, —O—C(?O)—, —O—C(?O)—O—, —C(?O)— or —Si(CH3)2—, and/or c2) one CH2 group may be replaced by —C?C—, cyclopropane-1,2-diyl, cyclobutane-1,3-diyl, cyclohexane-1,4-diyl or phenylene-1,4-diyl, and/or c3) one or more hydrogen atoms may be replaced by F and/or Cl, p, q, r are each independently 0 or 1 M1—is —CO—O—, —O—CO—, —CH2—O—, —O—CH2—, —CF2—O—, —O—CF2—, —CH?CH—, —CF?CF—, —C?C—, —CH2—CH2—CO—O—, —O—CO—CH2—CH2—, —CH2—CH2—, —CF2—CF2—, —(CH2)4—, —OC(?O)CF?CF— or a single bond, A1 is 1,4-phenylene where one or two hydrogen atoms may be replaced by F, Cl, CN and/or OCF3, or up to three hydrogen atoms may be replaced by fluorine, 1,4-cyclohexylene where one or two hydrogen at

Abstract: There is provided a method of simultaneously detecting at least two mutually different nucleic acid molecules in a sample, wherein in a first step a multiplex-PCR and in a second step a hybridizing reaction is carried out with probes immobilized on a microarray, whereupon the hybridized PCR products are detected and optionally quantitated, wherein the probes employed for the hybridizing reaction which in each case will hybridize specifically with the mutually different nucleic acid molecules have melting temperatures which differ from each other by 2° C. at the most, preferably by 1° C. at the most.

Abstract: The invention relates to a liquid-crystalline medium based on a mixture of polar compounds of negative dielectric anisotropy which comprises at least one compound of the formula I in which R11 and R12, ring A, Z, a, L1 and L2 are as defined in claim 1, and the use thereof for an active-matrix display based on the ECB effect.

Abstract: The invention relates to a cutting system for splitting pipes. The system includes a main body and at least one blade and at least two blade mount assemblies by which the blade may optionally be connected to the main body. The first blade mount assembly, in a particular fitted state, holds the blade at a different distance from the longitudinal axis of the main body than the second blade mount assembly.

Abstract: Compounds of the formula (I) where: R1, R2 are each independently a) H b) -M1-A1-R5 c) a straight-chain or branched alkyl radical having from 1 to 16 carbon atoms or astraight-chain or branched alkenyl radical having from 2 to 16 carbon atoms, where c1) one or more nonadjacent and nonterminal CH2 groups may be replaced by —O—, —C(?O)O—, —O—C(?O)—, —O—C(?O)—O—, —C(?O)— or —Si(CH3)2—, and/or c2) one CH2 group may be replaced by —C?C—, cyclopropane-1,2-diyl, cyclobutane-1,3-diyl, cyclohexane-1,4-diyl or phenylene-1,4-diyl, and/or c3) one or more hydrogen atoms may be replaced by F and/or Cl, p, q, r are each independently 0 or 1 M1—is —CO—O—, —O—CO—, —CH2—O—, —O—CH2—, —CF2—O—, —O—CF2—, —CH?CH—, —CF?CF—, —C?C—, —CH2—CH2—CO—O—, —O—CO—CH2—CH2—, —CH2—CH2—, —CF2—CF2—, —(CH2)4—, —OC(?O)CF?CF— or a single bond, A1 is 1,4-phenylene where one or two hydrogen atoms may be replaced by F, Cl, CN and/or OCF3, or up to three hydrogen atoms may be replaced by fluorine, 1,4-cyclohexylene where one or two hydrogen

Abstract: Compounds of the formula (I) where: X1 is H or F G1-G2 is —CH2—CH— or CH?C— R1, R2 are a) H b) the M2-A2-R5 moiety c) for example, a straight-chain or branched alkyl radical having from 1 to 16 carbon atoms R3 and R4 are each, for example, H, the M2-A2-R5 moiety or a straight-chain or branched alkyl or alkyloxy radical having from 1 to 16 carbon atoms A2 is, for example, 1,4-phenylene, with the provisos that a) when R2 is not H, R1 and R3 have to be H, b) when R2 is H, R4 must not have the definitions c) or d), c) R1, R2, R3 and R4 must not at the same time be H.

Abstract: A vibration sensor for direct or indirect mounting on a vibrating component has a housing, a pressure sleeve having a central bore and a piezoelectric disk situated between two insulator disks and two contact disks, a seismic mass acting on the disks by way of a spring element. The spring element is designed with a ring shape and has a projection on its inside ring area. On the outside circumference of the pressure sleeve there is a recess which is designed to correspond to the projection and is formed to accommodate the projection on the spring element.