Abstract: In a method for quenching metal parts, a quenching chamber is provided in which the quenching oil is continuously supplied from below the steel parts and circulated upward through the parts in a laminar flow. The circulation is accomplished by feeding the quenching oil onto the bottom of the quenching chamber of an auxiliary chamber surrounding it.

Abstract: In a cementation method of metals in which hydrocarbon gas and oxidization gas are introduced into a heat treatment furnace, a small quantity of hydrocarbon gas of is introduced at a low pressure into the heat treatment furnace. The shift time and the gradient of the carbon potential varying toward a predetermined high or low level are controlled by increasing or decreasing the quantity of cementation gas and oxidization gas to be supplied to the furnace. After the carbon potential is reached to the high or low level, the carbon potential is maintained for a predetermined time period so as to prevent the deposited carbide from being bulked. In order to prevent the gas supply pipe from being choked with the soot of the hydrocarbon, oxidization gas of intermediate pressure is flushed into the gas supply pipe.

Abstract: A treating material W pre-heated to a carburizing temperature of 750.degree.-950.degree. C. is heat-treated in a carburizing atmosphere directly supplied with hydrocarbon and oxidizing gases and heated to 1000.degree.-1100.degree. C. Then, the treating material W is forcibly cooled to a temperature below 600.degree. C., the treating material W is re-heated to 750.degree.-850.degree. C., and then it is hardened.Energy required to the carburization can be saved because drastic reduction of the treating time is possible.

Abstract: A gas-carburizing process wherein an article is treated by feeding a hydrocarbon gas and an oxidative gas of raw material gases directly into an atmospheric heat treating furnace, characterized in that, when the pressure within the furnace is negative, CO.sub.2 is fed as a negative pressure dissolving means.A gas-carburizing apparatus wherein a gas inlet for feeding a hydrocarbon gas and an oxidative gas provided in the ceiling part of an atmospheric heat treating furnace is provided with a CO.sub.2 feeding part for dissolving the negative pressure within the furnace.

Abstract: A gas-carburizing process wherein an article is treated by feeding a hydrocarbon gas and an oxidative gas of raw material gases directly into an atmospheric heat treating furnace, characterized in that, when the pressure within the furnace is negative, CO.sub.2 is fed as a negative pressure dissolving or eliminating means.A gas-carburizing apparatus wherein a gas inlet for feeding a hydrocarbon gas and an oxidative gas provided in the ceiling part of an atmospheric heat treating furnace is provided with a CO.sub.2 feeding part for eliminating the negative pressure within the furnace.

Abstract: In a gas carburizing method, a hydrocarbon gas and air are supplied to a furnace main body that carburizes a workpiece. The hydrocarbon gas and air react with one another in the furnace main body to generate an atmospheric gas having a carburizing property. The flow rate of the hydrocarbon gas to be supplied is maintained at a predetermined value. The flow rate of air to be supplied can be altered by adjusting the carbon potential of the atmospheric gas.A gas carburizing apparatus includes a furnace main body and load and unload chambers provided on two ends of the furnace main body. The load and unload chambers have combustion units. The combustion units communicate with the interiors of the load and unload chambers and burn a hydrocarbon gas. The combustion gas of the hydrocarbon gas is supplied to the load and unload chambers.

Abstract: L-2-Amino-4-methylphosphinobutyric acid (L-MPGA) which is useful as bactericide and herbicide can be prepared by optical resolution of its racemic mixture, D,L-MPGA with the action of a microbial acylase. The process comprises providing D,L-MPGA in the form of its N-acyl derivative, reacting N-acyl-D,L-MPGA in an aqueous medium with a microbial acylase having an optically specific hydrolytic activity, whereby selectively eliminating the acyl group of N-acyl-L-MPGA to give a mixture of L-MPGA and N-acyl-D-MPGA and isolating L-MPGA from the mixture. The acylase is produced by cultivating a microbial strain belonging to the genus Pseudomonas, Streptomyces or Aspergillus, particularly Pseudomonas maltophilia BN-233, Streptomyces violascens SF 2072, Streptomyces diastatochromogenes SF 2073, Aspergillus sp. KS-101 or Aspergillus sp. KS-102.

Abstract: Compounds are provided having the general formula I: ##STR1## wherein X represents an hydroxyl group, an acetoxy group or a thiosulfuric acid residue. The formula I compounds are prepared from compounds of the general formula II: ##STR2## wherein R.sub.1 represents hydrogen, a lower alkanoyl group, an arylalkanoyl group, an alkoxycarbonyl group, a lower haloalkoxycarbonyl group, a substituted or unsubstituted aroyl group, a N-arylcarbamoyl group of a substituted or unsubstituted aryl group; R.sub.2 either represents hydrogen or, together with the ##STR3## group, represents a phthalimido group; and X represents an hydroxyl group, an acetoxy group or a thiosulfuric acid residue, or their metal salts or their salts with organic bases, by causing the culture of a cephalosporin C acylase-producing strain of a microorganism, especially a mold, fungus, or the secondary preparation therefrom, to act on the latter compounds II in the presence of an aqueous medium.

Abstract: Novel 7-(5-amino-5-carboxyvaleramido)-7-methoxy-3-hydroxymethyl-3-cephem-4-carbo xylic acid derivatives. Such derivatives are prepared by subjecting cephamycin type compounds to the action of esterase enzyme of mold fungi.