Abstract: A method is provided for limiting the inflow of formation water during a well turn around to maximize polymer recovery after a hydraulic fracturing treatment of a formation. The method includes a step for selectively blocking the pore structure in a water-bearing zone and not blocking the pore structure of a hydrocarbon zone at the formation face; performing a hydraulic fracturing treatment using a fluid having a polymer; and turning the well around to recover the polymer. There is also provided a method of acidizing, preferably matrix acidizing, a formation having a hydrocarbon zone and a water-bearing zone. The method includes a step for selectively blocking the pore structure in the water-bearing zone at the formation face to selectively retard migration of acid into the water-bearing zone; and injecting acid into the formation, wherein the acid is diverted from the water-bearing zone to the hydrocarbon zone as a result of the selective blocking step.

Abstract: An optical alignment composition including polyimide having a cinnamate group at its side chain is disclosed. Also, there are disclosed an alignment layer formed using the composition and a liquid crystal display device (LCD) having the same. The alignment layer has an excellent thermal stability. According to the present invention, Since the alignment layer with excellent thermal stability is obtained, the LCD having excellent performance can be manufactured.

Abstract: An acrylonitrile derivative expressed by the following general formula I, a composition comprising the derivative and having an improved viscosity and optical anisotropy, and a liquid crystal display device: ##STR1## wherein rings A.sup.1 to A.sup.3 represent phenylene, cyclohexylene, dioxane, or pyrimidine, R.sup.

Abstract: A self cleaning filter for aqueous media such as sewage effluent which comprises a ventilated bed of discrete filtration material such as particulates, finely ground or shredded non-oil plastic materials, clay particulates, ground zeolite, diatomaceous earth powdered activated carbon, short fibre carbon and fine crushed charcoal, in which is dispersed a population of living organisms such as worms, insects, mothfly larvae, collembola, crustaceans and mites, which organisms have the ability to maintain at least a surface layer of the bed in an open and aerobic state.

Abstract: A swallow-tail-shaped liquid crystal compound of the following general formula (1), ##STR1## wherein A is --O--, --COO-- or a single bond (--), m is an integer of 4 to 12, and n is an integer of 2 to 4.The above swallow-tail-shaped liquid crystal compound of the present invention is a novel achiral anti-ferroelectric liquid crystal and can be converted to an optically active anti-ferroelectric liquid crystal by mixing it with an optically active compound as a chiral dopant.

Abstract: A liquid crystal cell which minimizes disordered orientation occurring with temperature changes even across a wide range, to exhibit good contrast and high reliability, as well as a smectic liquid crystal composition for use the liquid crystal cell are provided. In smectic liquid crystal compositions having a layer construction in the liquid crystal molecular arrangement, it was found that antiferroelectric liquid crystal compositions resistant to variation in the layer spacing of the smectic phase due to temperature changes are resistant to disordered orientation. Specifically, if the antiferroelectric liquid crystal composition contains at lest 45 wt % of an antiferroelectric liquid crystal compound with roughly constant layer spacing in a temperature range from the temperature t.sub.1 which gives the minimum value for the layer spacing of the smectic C.sub.A * phase to -20.degree. C., no disordered liquid crystal orientation results even after cold/hot temperature cycles.

Abstract: In a method for producing a semiconductor device using a dual tube reactor, inert gas is fed into the vertical reaction-tube, a reaction gas is introduced into the vertical reaction-tube, the inert gas is exhausted through the annular channel formed between the inner tube and the outer tube at a bottom portion of the vertical reaction-tube; and, a wafer is heat treated in the vertical reaction-tube by means of a heating furnace. In order to decrease the number and size of the particles, the wafer is displaced upward and then positioned at a level substantially the same as or above the top end of the inner tube, and the reaction gas is introduced into the vertical reaction-tube at or above the position of the wafer. Furthermore, the inert gas is caused to flow from a bottom portion of the inner tube toward the wafer positioned as above. As a result, inflow of the reaction gas into the inner tube is impeded, and the generation of particles there can be lessened.

Abstract: The invention, in one embodiment, is a novel fracturing fluid composition comprising an aqueous metal hydrated galactomannan gum, buffered to a pH of from about 9 to about 11. In another embodiment, a method of fracturing a formation is disclosed, the method being characterized by the use of the compositions mentioned.

Abstract: In the presence of certain crude oils, when ferric iron exists in very acidic fluid, it practically instantaneously forms precipitates known as sludges which lead to irreversible damage. Iron control compositions and acid fluids containing such iron control compositions are disclosed. For acid fluids containing up to 15% acid, the iron control composition includes a reducing agent selected from a substituted and unsubstituted thiourea compounds, and a reduction catalyst including a copper (cuprous or cupric) compound. When the acid fluid contains more than 15% acid, for example from 15 to 28% acid, the reducing agent is again selected from substituted or unsubstituted thiourea compounds, and the reduction catalyst is a combination of a copper (cuprous or cupric) compound and iodine (iodine or iodide ions).

Abstract: A liquid primer is misted, flowed into a deposition chamber and deposited on a substrate. A liquid precursor is then misted, flowed into a deposition chamber and deposited on the substrate. The primer and precursor are dried to form a solid thin film, which is then annealed to form a part of an electronic component in an integrated circuit, such as the dielectric in a memory cell. The primer is a solvent, and the precursor includes a metal carboxylate, a metal alkoxide, or a metal alkoxycarboxylate in a precursor solvent. Preferably, the primer and the precursor solvent are the same solvent, such as 2-methoxyethanol, xylenes, or n-butyl acetate.

Abstract: Polymeric well completion and remedial compositions which form highly pliable impermeable masses of desired rigidity and methods of using the compositions are provided. The compositions are basically comprised of water, a water soluble polymerizable monomer, a polymerization initiator and an oxygen scavenging agent. The composition is usually foamed and contains a gelling agent and a solid filler material to increase the density and/or rigidity of the impermeable mass formed.

Abstract: Liquid-crystalline medium based on a mixture of polar compounds having positive dielectric anisotropy, characterized in that it comprises one or more compounds of the general formula I, ##STR1## in which R is H, an alkyl or alkenyl radical having 1 to 15 carbon atoms which is unsubstituted by CN or CF.sub.3 or at least monosubstituted by halogen, it also being possible for one or more CH.sub.2 groups in these radicals to be replaced, in each case independently of one another, by --O--, --S--, ##STR2## --CO--, --CO--O--, O--CO-- or --O--CO--O-- in such a way that O atoms are not linked directly to one another and additionally comprises one or more compounds selected from the group consisting of the general formulae II, III, IV, V and VI defined herein.

Abstract: The improved recovery of hydrocarbons from subterranean formations by hydraulically fracturing a subterranean formation is accomplished. Fracturing fluids using a viscoelastic surfactant fluid containing wormlike micelles are useful to improve recovery of hydrocarbons and limit the loss of fracturing fluid into the formation fracture face. The invention further relates to novel fracturing methods useful for increasing hydrocarbon production, limiting connate water production, resisting fracturing fluid loss into the subterranean formation, and reducing the equipment requirements in mixing and pumping fracturing fluid. The action of micelles of surfactant in aqueous zones of the subterranean formation facilitates the flowback of increased amounts of hydrocarbons once a fractured well is placed back on production.

Abstract: An optically active compound which itself generally exhibits no antiferroelectric liquid crystal phase, but which can be added to an antiferroelectric liquid crystal or composition thereof having a high threshold voltage to reduce the threshold voltage of the resulting composition. Also disclosed is an antiferroelectric liquid crystal composition containing the optically active compound, a process for reducing the threshold voltage of an antiferroelectric liquid crystal composition, a process for producing the optically active compound, and a process for producing an optically active carboxylic acid as an intermediate.

Abstract: There is provided a liquid crystal composition in particular with a low threshold voltage and a wide range of nematic phase temperature (with high TNI point and low TC), while satisfying various properties required for liquid crystal compositions for active matrix type liquid crystal display elements. The composition contains, for example, compounds represented by general formulas (1-1) and (2-1): ##STR1## where each R.sub.1 independently represents an alkyl group having 1 to 10 carbon atoms; X.sub.1 represents H or F; and each X.sub.2 independently represents F, OCF.sub.3, CF.sub.3, or OCF.sub.2 H.

Abstract: A cut flower preservative slurry composition comprising a water insoluble or hardly soluble cut flower preservative component and a dispersing agent for dispersing the preservative component in water to form a slurry.

Abstract: 1,3-Dioxane compounds of the formula IR.sup.1 --(A.sup.1 --Z.sup.1).sub.m --W--(Z.sup.2 --A.sup.2).sub.n --R.sup.2(I)in whichW is ##STR1## and R.sup.1, R.sup.2, A.sup.1, A.sup.2, Z.sup.1, Z.sup.2, m, n, ##STR2## n.sub.1, n.sup.2, n.sub.3, n.sub.4, n.sub.5, n.sub.6, Z.sup.3 and Z.sup.4 are as defined herein,are suitable as components of liquid-crystalline media.

Abstract: The present invention relates to a perfume base composition comprising a carrier and a benzyl-substituted cyclohexanol having formula (1), wherein the dashed line denotes an optional double bond and the benzyl group is in the 2-, 3- or 4-position of the cyclohexanol ring, with the proviso that the benzyl group is in the 4-position when a double bond is present in the cyclohexanol ring. The composition has not only a well-balanced fragrance but also excellent retentivity of fragrance.

Abstract: A rust preventive composition which is obtained by blending at least one base oil selected from the group consisting of a hydrocarbon solvent, a mineral oil and a synthetic oil with, as essential components,(A) an organophosphoric ester calcium salt represented by the following general formula (1) in an amount of 0.1 to 5.0% by mass based on the total mass of the composition ##STR1## wherein R.sup.1 and R.sup.2 are each an alkyl group having 6 to 18 carbon atoms; and a and b are each an integer of 1 to 6,(B) water in an amount of 0.1 to 3.0 parts by weight based on 1 part by weight of the component (A), and(C) a rust inhibitor in an amount of 2.0 to 30% by mass based on the total mass of the composition.

Abstract: A silver sol comprises silver particles having a particle size ranging from 1 to 100 nm and a silver solid content ranging from 1 to 80% by weight. The silver sol can be prepared by a method comprising the steps of reacting a solution of a silver compound with a reducing agent at a temperature ranging from 5 to 50.degree. C. and a stirring speed falling within the range of from 1,000 to 10,000 rpm to form silver fine particles; recovering the resulting silver fine particles using a centrifugal separator; and then dispersing the silver fine particles in a medium to give a silver sol having a silver solid content ranging from 1 to 80% by weight. The silver sol or a coating material obtained by diluting the sol to a desired silver solid content and, if desired, adding a binder permits the formation of a transparent conductive film on, for instance, a cathode-ray tube while reducing the production cost.