Abstract: A smectic C liquid crystal mixture having a broad smectic C phase temperature range including room temperature, a ferroelectric smectic C liquid crystal mixture having a large spontaneous polarization, comprising the above smectic C mixture and at least one optically active compound, and a liquid crystal display element having an improved response time, containing the above ferroelectric smectic C liquid crystal mixture are provided, which smectic C liquid crystal mixture comprises(1) at least two components at least one of which is a pyrimidine compound expressed by the formula ##STR1## wherein R.sup.1 represents a linear alkyl group of 4 to 20 carbon atoms and R.sup.2 represents a linear alkyl group having 7-20 carbons and having a smectic C phase;(2) at least one pyrimidine compound of the formula (I) and at least one pyrimidine compound expressed by the formula ##STR2## wherein R.sup.3 represents a linear alkyl group of 6 to 12 carbon atoms and R.sup.

Abstract: The present invention provides diamino compounds and liquid crystal aligning films comprising polyimides which are obtained from the said diamino compounds represented by the general formula: ##STR1## wherein R.sub.1 indicates an alkyl group having 3 to 22 carbon atoms, R.sub.2 indicates a hydrogen atom or an alkyl group having 1 to 22 carbon atoms, and R.sub.3 -R.sub.10 indicate a hydrogen atom or a methyl group, respectively.The liquid crystal aligning films are useful for STN mode display cells in realizing a high pretilt angle.

Abstract: A ferroelectric liquid crystal composition comprising smectic liquid crystal compound(s) and optically active compound(s) and having high-speed response properties and a light switching element containing the same are provided, which composition comprises the following three liquid crystal components A, B and C, the respective proportions thereof being 10 to 70%, 10 to 50% and 10 to 40% each by weight based on the total weight of these components, respectively:liquid crystal component A:at least one compound selected from compounds of the formula ##STR1## wherein R.sup.1 and R.sup.2 each are 1-18C alkyl, and compounds of the formula ##STR2## wherein R.sup.3 and R.sup.4 each are 1-18C alkyl or alkoxy; liquid crystal compound B:at least one compound of the formula ##STR3## wherein R.sup.5 is a 1-18C alkyl, n is an integer of 0 to 10 and * indicates asymmetric carbon; andliquid crystal component C:at least one compound selected from compounds of the formula ##STR4## wherein R.sup.

Abstract: A nematic liquid crystal composition whose threshold voltage is scarcely influenced by temperature changes is provided, which composition comprises at least two components at least one of which is a compound expressed by the formula ##STR1## wherein R.sub.1 represents an alkyl group or an alkoxy group each of 1 to 10 carbon atoms, ##STR2## each independently represent a benzene ring or a cyclohexane ring and n represents an integer of 0 or 1, said compound being contained in 10 to 100% by weight in said composition.

Abstract: Novel ferroelectric liquid crystalline compounds having a superior stability and chiral, smectic liquid crystalline compositions containing at least one kind of the same are provided, which compounds are expressed by the formula ##STR1## wherein R is a C.sub.4 -C.sub.9 alkyl group.

Abstract: A ferroelectric liquid crystal composition having a long helical pitch and a light switching element having a quick response property are provided. This composition comprises (1) at least one member selected from the group consisting of liquid crystal compounds having a smectic C phase and no helical structure and liquid crystal compounds having only a nematic phase as a liquid crystal phase and no helical structure and (2) at least one chiral smectic liquid crystal compounds.

Abstract: A nematic liquid crystal composition having a notable increase of the twistability (i.e. the reciprocal of the intrinsic helical pitch) with temperature rise is provided, which composition comprises (i) optically active substance(s) which are the same in the helical twist sense to one another and make positive the temperature dependency of the twistability of the cholesteric phase induced when singly added to nematic compound(s), and (ii) nematic liquid crystal(s), which optically active substance(s) are a specified compound (I) containing a plurality of benzene, cyclohexane, dioxane, pyrimidine or/and pyridine ring and also having an optically active terminal group ##STR1## (R.sup.

Abstract: A nematic liquid crystal composition capable of improving reduction in the threshold voltage of TN type liquid crystal display elements and the temperature dependency thereof, and a liquid crystal display element using the composition are provided, which composition comprising 10 to 80% by weight of a first component comprising at least one compound expressed by the formula ##STR1## wherein m represents 0 or 1, R.sup.1 represents F or H and R.sup.2 represents an alkyl group of 1 to 8 carbon atoms, and 10 to 40% by weight of a second component comprising at least one compound expressed by the formula ##STR2## wherein l represents 1 or 2 and R.sup.2 is as defined above.

Abstract: Novel ferroelectric liquid crystals exhibiting a chiral smectic C phase and liquid crystal compositions containing the same are provided, which liquid crystals are substituted biphenyl esters expressed by the general formula ##STR1## wherein R.sub.1 * represents an optically active alkyl group of 4 to 18 carbon atoms; ##STR2## represents ##STR3## or ##STR4## Z represents R.sub.2, R.sub.2 CO or R.sub.2 COO wherein R.sub.2 represents an alkyl group or an alkoxy group each of 1 to 18 carbon atoms; and X and Y each represent hydrogen atom (H), bromine atom (Br), chlorine atom (Cl), fluorine atom (F) or cyano group (CN), and either one of X or Y is always hydrogen atom.

Abstract: Chiral smectic compounds having a high response rate and being superior as a ferroelectric liquid crystalline material, and chiral smectic mixtures containing the same are provided, which compounds being expressed by the formula ##STR1## wherein X represents --CH.sub.2 --, --O-- or --CO--; n represents 0, 1 or 2; when X represents --CH.sub.2 --, Y represents R--, R--CO--, ROCO--, ##STR2## wherein R represents an alkyl group having 1 to 18 carbon atoms, and when X represents --O-- or --CO--, Y represents R; and * represents a symbol indicating an optically active carbon atom.

Abstract: A liquid crystal compound containing an optically active group, suitable for being used for display mode utilizing ferroelectric liquid crystals, and a composition containing the same are provided, which compound is an optically active pyridazine compound expressed by the general formula ##STR1## wherein X represents an alkyl group or an alkoxy group each having 1 to 18 carbon atoms and R* represents an optically active group.

Abstract: Novel chiral smectic ester compounds suitable for a display mode utilizing ferroelectric liquid crystals, and liquid crystal compositions containing the same are provided, which compounds are expressed by the formula ##STR1## wherein R represents an alkyl group of 1 to 18 carbon atoms; R* represents an optically active alkyl group of 4 to 18 carbon atoms; X represents either one of a single bond, --O-- ##STR2## A represents ##STR3## and m and n each is 1 or 2.

Abstract: Chiral smectic compounds having a high response rate and being superior as a ferroelectric liquid crystalline material, and chiral smectic mixtures containing the same are provided, which compounds being expressed by the formula ##STR1## wherein X represents --CH.sub.2 --, --O-- or --CO--; n represents 0, 1 or 2; when X represents --CH.sub.2 --, Y represents R--, R--CO--, ROCO--, ##STR2## wherein R represents an alkyl group having 1 to 18 carbon atoms, and when X represents --O-- or --CO--, Y represents R; and * represents a symbol indicating an optically active carbon atom.

Abstract: Novel ferroelectric liquid crystalline compounds having a superior stability and chiral, smectic liquid crystalline compositions containing at least one kind of the same are provided, which compounds are expressed by the general formula ##STR1## wherein ##STR2## represents 1,4-phenylene group ##STR3## or 1,4-trans-cyclohexane group ##STR4## R*, an optically active alkyl group; m=o, 1 or 2; n=1 or 2; X, a linear chain or branched alkyl group or alkoxy group, each having 1 to 18 carbon atoms; and when ##STR5## represents ##STR6## m=1; and n=1, X represents a linear chain or branched alkyl group having 1 to 18 carbon atoms or a linear chain alkoxy group having 11 to 18 carbon atoms.

Abstract: A novel chiral liquid crystalline compound having an optically active group and a liquid crystal composition containing the same are provided, which compound is expressed by the general formula ##STR1## wherein R is a linear chain or branched alkyl group of 1.about.18 C; l is 0 or 1; X is COO or --O-- in the case of l=0 and COO, --O-- or --CH.sub.2 -- in the case of l=1; and * represents optically active carbon, and which compound, when used as a display element, brings about a higher response velocity.

Abstract: The present invention is characterized by a smectic liquid crystal compound represented by the following formula: ##STR1## wherein R is selected from alkyl and alkoxy groups; X from ##STR2## m and n are natural numbers; and R* is an optically active group containing an asymmetric carbon atom, and a liquid crystal composition containing said compound as a component. This compound is excellent in optical stability and high-speed response.

Abstract: In the delayed coking of a coking feedstock wherein the feedstock is continuously heated in a coking heater and introduced into a coke drum, the heater is operated to provide a coke drum temperature of from 415.degree. to 455.degree. C., and, after filling of the drum to the desired level, feedstock introduction is discontinued and the coke drum contents are heated at a temperature of 450.degree. C. to 500.degree. C., and which heating temperature is at least 10.degree. C. greater than the coking temperature, by passing a non-coking vapor through the contents of the drum to reduce the volatile combustible matter content to a value of 4% to 10% by weight and thereby reduce the CTE of the formed coke. The process is applicable to the production of needle coke from various kinds of feedstocks, in particular from a petroleum feedstock wherein the feedstock is initially treated by thermal soaking in the presence of sulfur, followed by thermal cracking to increase the aromaticity.

Abstract: A blower casing has a through hole formed in an end face, through which extends a motor which is drivingly coupled to a fan. An annular fitting flange member is rigidly fitted on the outer peripheral surface of the motor and joined at its peripheral edge to a portion of the above end face of the casing surrounding the through hole, for mounting the motor on the casing. The above through hole of the casing has its inner peripheral surface formed with an annular ridge which sealingly abuts against an opposed outer peripheral surface of the fitting flange member.

Abstract: A casing accommodating the heater core comprises a main body formed by first and second casing elements joined together at their peripheral edges, and a third casing element detachably joined to the main body and formed with hot air outlets. Part of the peripheral edges of the first and second casing elements cooperate to define an opening at which the third casing element is joined to the main body. The opening is exposed to the outside when the third casing element is detached from the main body, and through which the heater core can be removed from and fitted into the casing with ease.

Abstract: A heater (19) is disposed in an air flow duct (12) having an upper air outlet (22). An air filter (36) is disposed in a bypass duct (31) having an outlet (32) communicating with the upper outlet (22). Cool air flows into the bypass duct (31) from the air flow duct (12) upstream of the heater (19). Warm air is mixed with the cold air in the bypass duct (31) and is obtained either from the air flow duct (12) downstream of the heater (19) or is constituted by recirculated air from a vehicle passenger compartment.