Abstract: A process for preparing a polyamide is provided. The polyamide is prepared by causing a dicarboxylic acid and a diamine to polycondensate directly under an atmosphere of an inert gas at atmospheric pressure. The polycondensation reaction is mainly carried out in two diamine component-adding steps, one step comprising adding part of the diamine to the molten dicarboxylic acid until the molar ratio of the diamine to the dicarboxylic acid is brought to within the range of from 0.900 to 0.990 while raising continuously the temperature of the reaction mixture to a temperature not exceeding about 5.degree. C. above the melting point of the object polyamide and the other step comprising adding the remainder of the diamine to the reaction mixture maintained at a temperature higher than about 10.degree. C., but not exceeding about 35.degree. C. above the melting point of the object polyamide until the overall molar ratio of the diamine to the dicarboxylic acid is brought to within the range of from 0.995 to 1.005.

Abstract: A process for preparing a polyamide is provided. The polyamide is prepared by effecting direct polycondensation reaction of a dicarboxylic acid component containing at least 80 mole % of adipic acid and a diamine component containing at least 70 mole % of m-xylylene diamine under an atmosphere of an inert gas and at atmospheric pressure at a controlled temperature which is higher than the melting point of the dicarboxylic acid component and which can maintain the reaction mixture in a uniformly-fluidized state throughout the reaction.

Abstract: A composite sinter of silicon nitride/boron nitride, which consists essentially of, in weight percentage, silicon nitride within the range of from 60 to 97% and boron nitride within the range of from 3 to 40%, and wherein said boron nitride is present as a dispersed phase in the network of said silicon nitride; said composite sinter of silicon nitride/boron nitride being manufactured by the steps of: kneading a silicon powder within the range of from 47.3 to 95.1 wt.% and a boron nitride powder within the range of from 4.9 to 52.7 wt. %, as raw materials, with the use of an organic solvent solution containing a dispersant and a binder; press-forming the resultant kneaded mixture to prepare a green compact; sintering said green compact in a non-oxidizing atmosphere at a temperature within the range of from 1,100.degree. to 1,300.degree. C.

Abstract: A process for the preparation of a modified aromatic hydrocarbon resin which comprises reacting an aromatic hydrocarbon-formaldehyde resin with an unsaturated polybasic acid or an anhydride thereof, together with a saturated polybasic acid or an anhydride thereof if necessary, in the presence or absence of water, while introducing steam into the reaction system to remove by-produced formaldehyde out of the reaction system, and reacting the formed reaction product with at least one dihydroxy compound selected from the group consisting of (A) a glycol and (B) a hydroxy-terminated oligomer obtained by reacting a glycol with an unsaturated polybasic acid or an anhydride thereof; the cured product of the modified aromatic hydrocarbon resin being excellent in mechanical strength and resistance to water and alkalis.

Abstract: A modified aromatic hydrocarbon resin is prepared by reacting an aromatic hydrocarbon-formaldehyde resin with an unsaturated polybasic acid or an anhydride thereof, if desired, together with a saturated polybasic acid or an anhydride thereof, while making water or water and an aliphatic alcohol present in the reaction system and removing the formaldehyde formed by the reaction. The cured product has a good mechanical strength and a high resistance to water and alkalis.

Abstract: Processes for producing an oligoester and producing unsaturated polyester resin by use of the oligoester using unsaturated dibasic acid or its anhydride and isophthalic acid as dibasic acid components, and propylene oxide as a polyol component, characterized by (a) the step of reacting isophthalic acid with propylene oxide in the presence of an amine compound catalyst to form an oligoester, (b) the step of removing volatile components from the oligoester by heating it at a temperature range of 180.degree.-300.degree. C., (c) the step of treating the resulting oligoester with silica-alumina compound having adsorbing property, and (d) the step of reacting the oligoester so treated with the unsaturated dibasic acid or its anhydride.

Abstract: A therapeutic agent for treating consciousness disorder and perception and movement which comprises as an essential active ingredient a phosphatidic acid derivative selected from a phosphatidylcholine, a phosphatidic acid and a phosphatidylethanolamine in admixture with a conventional carrier. Said agent is administered to the patient suffered from consciousness disorder and perception and movement disorder, particularly the post-traumatic syndrome of the head injury and the sequelae of apoplexy or whiplash injury in oral or parenteral route, preferably in an intravenous route.

Abstract: The invention concerns a casting vessel having a basic lining, and usage thereof. For putting in practice the casting vessel employing basic refractories as a lining material and in order to avoid such phenomena as exfoliation or others caused by thermal stress generated in the inside of the lining, a backing between the lining and an outer shell is partially or entirely composed of cushion material having thickness within specific range, thereby to absorb said stress and save a life of the lining, and further temperature within the casting vessel is kept above determined temperature before it holds molten metal, thereby to make more efficient use of the life of the basic lining.

Abstract: A magnetic video recording and reproducing system in which a luminescence signal of a color television signal is frequency-modulated and a carrier chrominance signal is frequency-converted to a lower frequency side is disclosed, wherein during recording operation a burst signal of an input carrier chrominance signal is phase-compared with a signal from a variable frequency oscillator to produce an error signal which is used to control the variable frequency oscillator, and during playback operation a burst signal of a reproduced carrier chrominance signal is phase-compared with an output signal from a fixed frequency oscillator to produce an error signal which is used to control the variable frequency oscillator.

Abstract: The invention concerns a casting vessel having a basic lining, and usage thereof. For putting in practice the casting vessel employing basic refractories as a lining material and in order to avoid such phenomena as exfoliation or others caused by thermal stress generated in the inside of the lining, a backing between the lining and an outer shell is partially or entirely composed of cushion material having thickness within specific range, thereby to absorb said stress and save a life of the lining, and further temperature within the casting vessel is kept above determined temperature before it holds molten metal, thereby to make more efficient use of the life of the basic lining.

Abstract: Improved process for preparing 1,2-diacyl-3-glycerylphosphorylcholines, wherein the diacyl groups are, different or the same, a residue of a saturated or unsaturated fatty acid, particularly one of the acyl groups being a residue of a highly unsaturated fatty acid or being a residue of a saturated or unsaturated fatty acid labelled with an isotope, which comprises acylating a glyceryl-phosphorylcholine or monoacyl derivative thereof or the salt thereof with an acylating agent (e.g. 1-acylimidazole or 4-acyl-3-phenyl-1,2,4-oxadiazol-5-one) in the presence of a catalyst (e.g. an alkali salt of a nitrogen-containing 5-membered heterocyclic compound or sodium oxide).

Abstract: A periscope-type rear view mirror for automobiles which has a planar objective mirror positioned above an aperture formed through the roof of the driver's compartment of the automobile body for reflecting the light rays coming from behind the automobile forwardly and downwardly into the driver's compartment. A planar reflecting mirror is positioned substantially parallel to the objective mirror in the driver's compartment for reflecting the light rays reflected from said objective mirror forwardly and upwardly to a planar eye-piece mirror positioned close to said reflecting mirror and having a mirror surface crossing obliquely at an acute angle for reflecting the light rays reflected from said reflecting mirror into the driver's eye position. Said reflecting mirror is fixed to a stay, and said eye-piece mirror is pivotally secured to said stay which, in turn, is pivotably secured to the inner wall of the automobile at a position close to said aperture.

Abstract: A polyamide molding composition is disclosed comprising the admixture of glass fibers, nylon 6,6, and an MX nylon, obtained from the condensation of a xylylenediamine and an .alpha.,.omega.-straight chain aliphatic dibasic acid having 6-12 carbon atoms.

Abstract: A glass fiber-reinforced polyamide resin molding material, comprising a polyamide resin obtained by the condensation reaction of xylylene diamine with at least one member selected from straight-chain aliphatic .alpha.,.omega.-dicarboxylic acids having 6 to 12 carbon atoms and incorporated therein, glass fiber in an amount of 5 to 50% by weight based on the total weight of the polyamide resin and the glass fiber, and a shaped article obtained by molding aforesaid molding material.

Abstract: A periscope-type rear view mirror apparatus for automobiles is disclosed. The apparatus includes a roof-top planar objective mirror positioned above an aperture formed in the roof of the driver's chamber of an automobile for reflecting forwardly and downwardly the light rays coming from the rear of the automobile into the driver's chamber, a first planar reflecting mirror positioned in the driver's chamber for reflecting forwardly and upwardly the light rays reflected by the objective mirror, and a second planar reflecting mirror positioned close to the first reflecting mirror for reflecting the light rays reflected by the first reflecting mirror to the eyes of the driver. The first reflecting mirror is supported by a pivotably hinged holder to allow the vertical angular adjustment of the holder, whereby the first reflecting mirror can be used as an ordinary rear view mirror of the type normally installed in the driver's chamber.