Abstract: A method and system for applying a liner material to a contoured surface, such as an exposed rock face in an underground hard rock mine, is disclosed. Locations of a plurality of spatially distributed surface grid points on the contoured surface may be detected so as to generate a representative topographical profile of the contoured surface. Based on the plurality of surface grid points, a spray path for a liner application device configured to emit a spray of the liner material may be determined. In some cases, the spray path may have a trajectory that follows the topographical profile of the contoured surface offset therefrom within a spray range of the liner application device. Liner material may then be sprayed onto the contoured surface while controlling the liner application device to undertake at least one pass of the spray path.

Abstract: A method and system for applying a liner material to a contoured surface, such as an exposed rock face in an underground hard rock mine, is disclosed. Locations of a plurality of spatially distributed surface grid points on the contoured surface may be detected so as to generate a representative topographical profile of the contoured surface. Based on the plurality of surface grid points, a spray path for a liner application device configured to emit a spray of the liner material may be determined. In some cases, the spray path may have a trajectory that follows the topographical profile of the contoured surface offset therefrom within a spray range of the liner application device. Liner material may then be sprayed onto the contoured surface while controlling the liner application device to undertake at least one pass of the spray path.

Abstract: A method and system for applying a liner material to a contoured surface, such as an exposed rock face in an underground hard rock mine, is disclosed. Locations of a plurality of spatially distributed surface grid points on the contoured surface may be detected so as to generate a representative topographical profile of the contoured surface. Based on the plurality of surface grid points, a spray path for a liner application device configured to emit a spray of the liner material may be determined. In some cases, the spray path may have a trajectory that follows the topographical profile of the contoured surface offset therefrom within a spray range of the liner application device. Liner material may then be sprayed onto the contoured surface while controlling the liner application device to undertake at least one pass of the spray path.

Abstract: A compound of formula (I): where R1 is alkyl or alkenyl, Y1 and Y2 are independently selected from oxygen or sulphur, n is an integer of from 1 to 5, A is an optionally substituted phenyl or an optionally substituted cycloalkyl ring, X is a direct bond, a C1-4alkylene, a C2-4alkenylene, an acetylene, —CO(O)— or a group of sub-formula (i): where X1 and X2 are independently selected from a direct bond, a C1-4alkylene, a C2-4alkenylene, an acetylene, —CO(O)— and R2, R3 and R4 are independently selected from hydrogen, halo or cyano, provided that no more than one of R2, R3 and R4 is hydrogen. These compounds have a high dipole moment and may be used as dopants in liquid crystal mixtures.

Abstract: The use of a compound of formula (I) wherein R1 is an alkyl or alkenyl group, either of which may be optionally interposed with one or more oxygen or sulphur atoms, R2 is an alkyl or alkenyl group, Y? and Y? are independently selected from oxygen or sulphur, n is an integer from 1 to 5, X is a direct bond or a C1-4alkylene or C2-4alkenylene chain, and A is group comprising one or two rings which are independently selected from aryl, heterocylic or cycloalkyl rings, and when there are two rings, they are bonded together directly or by way of a C1-4alkylene or C2-4alkenylene group, for increasing the u.v. stability of a liquid crystal mixture. The compounds of formula (I) are u.v. stable and are useful in liquid crystal devices which are exposed to high levels of u.v. light such as phosphor display cells. Certain compounds are novel and these form a further aspect of the invention.

Abstract: The use of a compound of formula (I) 1

Abstract: Alignment layers for use in liquid crystal devices comprising photoactive pentaerythritol derivatives. 1,2,3,4-trakiskis(8-[2-oxo-2H-1-benzopyran-7-yloxy]octanoyloxy)pentaerythritol is but one example.

Abstract: Compounds of formula (I) may be used as alignment layers in liquid crystal devices wherein X1-5 are idependently selected from H, F, CN, phenylene, C1-10 alkyl, whereby when X1=X2, then X1,2=H and when X3=X4, then X3,4=H, S1-3 are spacer units, PG1-3 are photoisomerisable/dimerisable groups.

Abstract: Compounds of formula (I) are provided 1

Abstract: Liquid crystalline compounds useful in super twisted nematic liquid crystal displays are described and have the formula: wherein n is 1-5; m is 0-5; p is 0, 1 or 2; q is 0, 1 or 2 p+q is less than or equal to 3; A1, A2, A3 are independently chosen from 1,4-disubstituted benzene, 2,5-disubstituted pyrimidine, 1,5-disubstituted pyridine, 2,6-disubstituted naphthalene which may be laterally substituted with F, Cl, Br or CN, trans-1,4-disubstituted cyclohexane, 2,5-disubstituted dioxane, 2,5-disubstituted thiophene, 2,5-disubstituted furan, 2,5-disubstituted thiodiazole Z1 may be COO, OOC, OCH2, O; Z2, Z3 are independently chosen from a direct bond, COO, OOC, C2H4, CH2O, OCH2, C4H8, C3H6O, (E)—CH═CHC2H4, (E)—CH═CHCH2O, —C≡C—; R1 is alkyl, and may contain up to 20 carbon atoms and may be branched or a straight chain; provided that at least one of, A1, A2, A3 is selected from 1,4-disubstituted thiophene.

Abstract: Compounds of formula (I) are provided which are particularly useful in super twisted nematic devices, where n may be 0-5; m may be 0-5; p may be 1-9; q may be 1, 1, or 2; A1, A2 are independently chosen from 1-4, -disubstituted benzene, 2,5-disubstituted pyrimidine, or 2,5-disubstituted pyridine, trans- 1,4-disubstituted cyclohexane, trans- 2,5-disubstitued dioxane. The aromatic rings may be laterally substituted with F, Cl, Br or CN; Z1 may be O, COO, OOC; Z2, Z3 are independent chosen from a direct bond, COO, OOC, C2H4, CH2O, OCH2, or -c≡c-, provided that when Z1 is O and m is 1, 3 or 5 the carbon—carbon double bond configuration is E; provided that when Z1 is O and m is 2 or 4 the carbon—carbon double bond configuration is Z; provided that when Z1 is COO or OOC and m is 0, 2 or 4 the carbon—carbon double bond configuration is E; and provided that when Z1 is COO or OOC and m is 1, 3 or 5 the carbon—carbon double bond configuration is Z.

Abstract: Liquid crystalline compounds useful in super twisted nematic liquid crystal displays are described and have the formula: ##STR1## wherein n is 1-5;m is 0-5;p is 0, 1 or 2;q is 0, 1 or 2p+q is less than or equal to 3;A.sub.1, A.sub.2, A.sub.3 are independently chosen from 1,4-disubstituted benzene 2,5-disubstituted pyrimidine, 1,5-disubstituted pyridine, 2,6-disubstituted naphthalene which may be laterally substituted with F, Cl, Br or CN, trans-1,4-disubstituted cyclohexane 2,5-disubstituted dioxane, 2,5-disubstituted thiophene, 2,5-disubstituted furan, 2,5-disubstituted thiodiazoleZ.sub.1 may be COO, OOC, OCH.sub.2, O;Z.sub.2, Z.sub.3 are independently chosen from a direct bond, COO, OOC, C.sub.2 H.sub.4, CH.sub.2 O, OCH.sub.2, C.sub.4 H.sub.8, C.sub.3 H.sub.6 O, (E)--CH.dbd.CHC.sub.2 H.sub.4, (E)--CH.dbd.CHCH.sub.2 O, --C.tbd.C--;R.sub.1 is alkyl, and may contain up to 20 carbon atoms and may be branched or a straight chain; provided that at least one of, A.sub.1, A.sub.2, A.sub.

Abstract: Anisotropic compounds of the formula (1) specified in claim 1 are suitable, owing to their low .DELTA..epsilon./.epsilon..perp. values for liquid crystal displays which have high information densities of for examples up to 10.sup.6 image dots and accordingly need to be highly multiplexible; compared with known compounds they offer improved application properties and are relatively simple to synthesize.

Abstract: Nematic compounds with a negative DC antisotropy, characterized by the formula I ##STR1## in which m=1 or 2, r is zero or 1 and m+r=1 or 2, and R.sup.1 and R.sup.2 are identical or different and are selected from alkyl and alkoxy groups each having 1-12 carbon atoms in a straight or branched chain, which may be chiral, Z is a bridge member selected from a single bond and the groups of the formulae --CH.sub.2 CH.sub.2 --, --OCH.sub.2 --, --O--CO-- or --CO--O--, one of the groups X and Y is selected from fluorine, chlorine, bromine and cyano and the other of the groups X and Y is selected from hydrogen, fluorine, chlorine, bromine and cyano, with the proviso that m=r=1 if X and Y are both cyano, are suitable as components for liquid crystal mixtures having an overall negative DC anisotropy, such as are required in particular for electro-optical displays of the type of guest/host displays or homotropic-nematic displays.

Abstract: Anisotropic compounds having negative DC anisotropy and improved photochemical stability have the formula (1) given in patent claim 1; none of the benzene rings present in the molecule (1) is bonded directly to two oxygen atoms, as a result of which quinoidal bonding states which reduce the photochemical stability of anisotropic compounds in the case of benzene rings with two lateral nitrile groups are excluded.

Abstract: Novel liquid crystal ester compounds exhibiting a low or negative dielectric anisotropy have a structural formula: ##STR1## where R.sub.1 is an alkyl group, R.sub.2 is an alkyl or alkoxy group, ##STR2## is a 1,4-disubstituted bicyclo(2,2,2) octane ring and ##STR3## is a 1,4-disubstituted ring selected from the following: (i) a 1,4-disubstituted bicyclo(2,2,2) octane ring;(ii) a trans-1,4-disubstituted cyclohexane ring;(iii) a laterally substituted benzene ring ##STR4## where of the two groups Y and Z one is a halogen or a cyano group and the other is hydrogen or a halogen or a cyano group such that Y is the same as Z.These esters may be used in a number of known applications including liquid crystal materials for multiplexed twisted nematic devices.The esters may be made by preparative methods involving known steps.

Abstract: Novel liquid crystal compounds exhibiting a low dielectric anisotropy have a structural formula: ##STR1## where R.sub.1 is an alkyl group, R.sub.2 is a group containing an alkyl group R and is either an alkyl group R, an alkoxy group OR, an alkylcarbonyloxy group OCOR or an alkoxycarbonyloxy group OCOOR, R.sub.1 and R containing up to 18 carbon atoms, ##STR2## is a trans-1,4-disubstituted cyclohexane ring ##STR3## or a 1,4-disubstituted bicyclo(2,2,2)octane ring ##STR4## and Ar is a 1,4 disubstituted benzene ring ##STR5## a 3-fluoro-1,4 disubstituted benzene ring ##STR6## or a 2,6 disubstituted naphthalene ring ##STR7## These compounds may be used in liquid crystal mixture compositions for use in a number of known electro-optic effects.The compounds may be prepared by routes in which the individual steps involved are known.

Abstract: A novel liquid crystal compound has the molecular structure: ##STR1## where R is an alkyl group, which may contain up to 18 carbon atoms and which may be normal or branched and may contain a chiral center, ##STR2## is a bicyclo (2.2.2) octane ring, --X-- is and Y is a cyano group CN or R.sup.1 or OR.sup.1 where R.sup.1 has the same definition as R.The compound may be used in mixtures with other liquid crystal compounds in the same or other families and the compound or mixtures may be used in known liquid crystal devices, eg the twisted nematic and cholesteric-to-nematic phase change devices, depending on its properties.

Abstract: A novel liquid crystal compound has the molecular structure: ##STR1## where R is an alkyl group, which may contain up to 18 carbon atoms and which may be normal or branched and may contain a chiral center, ##STR2## is a bicyclo (2.2.2) octane ring, ##STR3## is a phenyl ring and CN is a cyano group, n being an integer greater than 0 preferably 1 or 2.The compound may be used in mixtures with other liquid crystal compounds in the same or other families and the compound or mixtures may be used in known liquid crystal devices, eg the twisted nematic and cholesteric-to-nematic phase change devices, depending on its properties.

Abstract: Anisotropic compounds of the formula (1) specified in claim 1 are suitable, owing to their low .DELTA..epsilon./.epsilon..perp. values for liquid crystal displays which have high information densities of for examples up to 10.sup.6 image dots and accordingly need to be highly multiplexible; compared with known compounds they offer improved application properties and are relatively simple to synthesize.