Abstract: There is disclosed a method for processing a silver halide photographic light sensitive material comprising the steps ofdeveloping the light sensitive material with a developing solution,treating the light sensitive material with a fixing capacity-having solution, and thentreating the light sensitive material with a processing solution (S), wherein part of or the whole of overflow from a tank containing the processing solution (S) is allowed to flow into a tank containing the fixing capability-having solution, and wherein solid processing chemicals are added to the fixing capacity-having solution or the overflow from the tank containing the processing solution (S).

Abstract: A transparent glass preform for an optical fiber is produced by heating a glass soot preform to remove gas from the soot preform at a temperature at which the soot preform is not vitrified under reduced pressure, and then heating the preform at a temperature at which the preform is vitrified under reduced pressure, whereby the transparent glass preform containing no or little bubbles and having a uniform outer diameter is produced.

Abstract: The present invention providesa process for the dehydrating and purifying treatment by heating a porous glass preform for an optical fiber comprising passing the porous glass preform through a muffle tube having a SiC layer at least on its inner surface at a high temperature under an atmosphere comprising an inert gas and a silicon halogenide gas;a process for the fluorine-doping treatment by heating a porous glass preform for an optical fiber comprising passing a porous glass preform through a muffle tube having a SiC layer at least on its inner surface at a high temperature under an atmosphere comprising a fluorine compound gas and an inert gas; anda process for the vitrifying treatment by heating a porous glass preform for an optical fiber comprising passing the preform, which has been previously dehydrated and purified, through a muffle tube having a SiC layer at least on its inner surface at a high temperature under an atmosphere gas.

Abstract: Disclosed is a stabilizing solution for a light-sensitive silver halide color photographic material, comprises a compound represented by the following Formula I, and has a surface tension of from 15 to 60 dyne/cm at 20.degree. C.; ##STR1## wherein Z represents a group of atoms necessary to form a substituted or unsubstituted cyclic hydrocarbon or heterocyclic ring, X represents an aldehyde group, ##STR2## wherein R.sub.1 and R.sub.2 each represent a lower alkyl group. The stabilizing solution and the processing method for a light-sensitive silver halide color photographic material according to this invention, can provide a processing technique that can achieve a superior stability of dye images, can better prevent backside deposits, can promise superior solution stability, and can better prevent yellow staining.

Abstract: A heating furnace for heating a porous preform made of fine particles of quartz base glass for an optical fiber which comprises a heater and a muffle tube positioned inside the heater to separate a heating atmosphere from the heater, wherein the muffle tube body consists of highly pure carbon and an inner wall and an outer wall of the body is coated with a carbon material selected from the group consisting of pyrolytic graphite and solid-phase carbonized glassy carbon.

Abstract: A glass preform for use in the fabrication of an optical fiber having a reduced transmission loss is produced by synthesizing a soot preform by a vapor synthesis method and consolidating the soot preform in an electric furnace to obtain a glass preform, wherein an intermediate body consisting of a core portion and an inner part of a cladding portion is consolidated under atmospheric pressure and an outer part of the cladding portion which surrounds a periphery of the intermediated body is consolidated under reduced pressure or in vacuo.

Abstract: This invention relates to a sintering furnace for the production of a quartz preform which can be used for carrying out dehydration, fluorine-addition and/or sintering of a porous quartz soot preform prepared by a flame hydrolysis method such as a VAD method or a OVD method, and in particular, to such a furnace in which joints in a long furnace muffle so long that fabricating it as open body is impossible can be maintained fully gas-tight, so that it is possible to prevent H.sub.2 O, O.sub.2 and other impurities in the air from entering the muffle from outside, and corrosive and poisonous gases in the muffle are prevented from leakage to outside the muffle.

Abstract: A heating furnace for heating a porous preform made of fine particles of highly pure quartz glass for an optical fiber, which furnace comprises a cylindrical furnace body, a heater installed in said furnace body and a muffle tube installed inside said heater to separate a heating atmosphere from said heater, wherein said muffle tube is made of highly pure carbon and coated with a gas impermeable carbon, which furnace prevents contamination of the preform with impurities and has long life.

Abstract: The present invention providesa process for the dehydrating and purifying treatment by heating a porous glass preform for an optical fiber by passing the porous glass preform through a muffle tube having a SiC layer at least on its inner surface at a high temperature under an atmosphere containing an inert gas and a silicon halogenide gas;a process for the fluorine-doping treatment by heating a porous glass preform for an optical fiber by passing a porous glass preform through a muffle tube having a SiC layer at least on its inner surface at a high temperature under an atmosphere containing a fluorine compound gas and an inert gas; anda process for the vitrifying treatment by heating a porous glass preform for an opticla fiber by passing the preform, which has been previously dehydrated and purified, through a muffle tube having a SiC layer at least on its inner surface at a high temperature under an atmosphere gas.

Abstract: There is provided a heating furnace comprising a furnace body, a cylindrical zone heater in the furnace body, a muffle tube installed through the furnace body for thermally treating a porous preform made of high purity quartz glass by moving the preform vertically therethrough and a partition means in the portion of the muffle tube projecting above the furnace body to divide an interior space of the muffle tube into an upper space and a lower one.

Abstract: A heating furnace for heating a porous preform made of fine particles of quartz base glass for an optical fiber in an atmosphere comprising a fluorine-containing atmosphere to add fluorine to the preform and to vitrify the preform to produce a glass preform for an optical fiber, which comprises a heater and a muffle tube positioned inside the heater to separate a heating atmosphere from the heater, wherein at least the inner layer of the muffle tube consists of highly pure carbon.

Abstract: A raw material supplying device having a gas tight tank for receiving a material to be gasified by heating; a heater for heating the raw material within the tank and a plurality of pipes for conveying a plurality of streams of gas in parallel to each other to a plurality of ports of a reaction apparatus, and a process for using the raw material supplying device. The raw material supplying device can be used in a system for manufacturing glass fibers in which the ends of the plurality of pipes are connected to the gas feed ports of at least one multi-layer burner.

Abstract: Disclosed are a magnesia-calcium oxide refractory product comprising (i) about 100 parts by weight of a refractory aggregate consisting essentially of about 20 to about 95% by weight of MgO and about 80 to about 5% by weight of CaO and (ii) about 0.5 to about 5 parts by weight of aragonite-type calcium carbonate, and a process for preparing the same.

Abstract: A gas reaction apparatus for manufacturing base material of optical fiber and a multi-wall pipe type burner for the gas reaction apparatus. The gas reaction apparatus includes a mechanism which heats or heat insulates at least one of gas passages of the burner for gaseous raw material of optical fiber so as to set a saturated vapor pressure of whole kinds of the gaseous raw material higher than a partial pressure of raw material of optical fiber in the gaseous raw material when the gaseous raw material is fed through the one of the gas passages.

Abstract: The disclosed ion beam machining device has a plasma-generating chamber, a machining chamber, and an ion-extracting grid disposed between the two chambers, which grid has an insulator layer facing the plasma-generating chamber and a conductor layer facing the machining chamber.