Abstract: Hydroxycarboxylic acids including glycolic acid are promising compounds for use as a raw material for polymers or an intermediate for medicines. However, the processes for the production of hydroxycarboxylic acids which are presently known have a problem that none of them can supply an inexpensive high-purity hydroxycarboxylic acid. An object of the invention is to produce a microorganism which highly yields in a short time a hydroxycarboxylic acid reduced in impurity content and to provide a process for producing a hydroxycarboxylic acid including glycolic acid using the microorganism. A microorganism is produced, which has the imparted or enhanced activity of an enzyme catalyzing a reaction from ethylene glycol to glycolaldehyde. Using this microorganism, a hydroxycarboxylic acid including glycolic acid which is reduced in impurity content is highly produced in a short time. The production process enables a hydroxycarboxylic acid having high purity to be supplied at low cost.

Abstract: A screw compressor is equipped with a manually operated internal volume ratio adjusting slide valve and capacity adjusting slide valve. The compressor is simple in construction, can be produced with low cost, can accommodate decrease in suction pressure, for example, in an aged gas well, and can be operated without an electric power source for controlling the operation thereof. Also a combined screw compressor unit consisting of a plurality of screw compressors for producing high discharge pressure is provided which can accommodate high suction pressure in order not to overload the higher pressure compressor or compressors with the efficiency of the unit kept as high as possible by including at least a screw compressor according to the present invention in the unit.

Abstract: The present invention provides a hydrocarbon material with a high ion adsorption ability (specific capacitance) per unit volume of the electrode obtained by heating a starting material mainly composed of polysaccharides, which are easy to obtain and inexpensive. More specifically, the hydrocarbon material can be obtained by heating a polysaccharide-based raw material together with a heat reaction auxiliary under an inert gas atmosphere, and has the following properties: (a) the hydrogen/carbon ratio (atomic ratio) is within the range of 0.05 to 0.5; (b) the specific surface area determined by the BET method is in the range of 600 to 2000 m2g; (c) the mesopore capacitance determined by the BJH method is in the range of 0.02 to 1.2 ml/g; (d) the total pore volume measured by the MP method is in the range of 0.3 to 1.25 ml/g; and (e) the bulk density of an electrode obtained using the hydrocarbon material is 0.60 g/ml or higher.

Abstract: A multi-stage screw compressor unit and method of operation thereof are provided, which enable operation with high efficiency always even when suction or discharge pressure fluctuates widely, the compressor unit comprising a combination of a compression stage provided with an unloader slide valve and that provided with an internal volume ratio control valve, or a combination of compression stage provided with an internal volume control valve and that of fixed internal volume ratio, or a combination of compression stages each provided with an internal volume control valve.

Abstract: Because conditions for recording identification data of a medium vary in accordance with the structure of different media, such as a single-layer or a multiple-layer structure, stable data recording has been a difficult task. To solve this problem, an incident side of the laser beam for recording identification data on a single-layer optical disk 5 and a double-layer optical disk 6 is the opposite side of a substrate 1 upon which user data is recorded. From this structure, even in a double-layer optical disk 6, the recording is not affected by the recording layer of a second layer 12b and the like. Therefore, in the double-layer optical disk 6, identification data of the medium can be recorded under the same conditions as the single-layer optical disk 5.

Abstract: This invention provides a novel D-aminoacylase obtained by cloning a DNA encoding the novel D-aminoacylase from Methylobacterium mesophilicum MT 10894, etc. and which shows sufficiently high activity at an industrially useful substrate concentration to allow a D-amino acid to be efficiently produced from an N-acyl-DL-amino acid; a DNA encoding the D-aminoacylase; a process for producing a D-amino acid from the corresponding N-acylamino acid using a transformant containing the DNA.

Abstract: A screw compressor is equipped with a manually operated internal volume ratio adjusting slide valve and capacity adjusting slide valve. The compressor is simple in construction, can be produced with low cost, can accommodate decrease in suction pressure, for example, in an aged gas well, and can be operated without an electric power source for controlling the operation thereof. Also a combined screw compressor unit consisting of a plurality of screw compressors for producing high discharge pressure is provided which can accommodate high suction pressure in order not to overload the higher pressure compressor or compressors with the efficiency of the unit kept as high as possible by including at least a screw compressor according to the present invention in the unit.

Abstract: In reacting pentose-1-phosphoric acid with a nucleic acid base or a nucleic acid base analogue in an aqueous reaction medium in the presence of a metal cation to produce a nucleoside compound, the timing or method of addition of at least one of these components to the aqueous reaction medium is varied; thereby, a nucleoside compound can be produced at a high yield efficiently without inviting the high viscosity or solidification of the reaction mixture, even when the above components are used in such amounts that the reaction mixture becomes highly viscous or is solidified when the components are used without the above variation of the addition timing or method. Thus, there can be provided a process for producing a nucleoside compound, which comprises a step of reacting pentose-1-phosphoric acid with a nucleic acid base or a nucleic acid base analogue in the presence of nucleoside phosphorylase activity, which gives a nucleoside compound at an improved conversion, and which has wide applicability.

Abstract: The invention provides a method of operating a screw compressor equipment without reducing the efficiency, in which a screw compressor 1 of which the internal volume ratio is variable by means of an internal volume ratio control valve is driven by a driving machine 2, the discharge side of the compressor 1 is communicated with the suction side of the same by way of a bypass control valve 9 as needed, the internal volume ratio control valve 3 is always controlled to be located at a position calculated so that the internal volume ratio with which the polytropic efficiency is maximum is obtained, and gas flow rate is controlled by controlling the rotation speed under normal conditions and controlled by controlling the bypassing flow rate from the discharge side to the suction side under very low rotation speed.

Abstract: A multi-stage screw compressor unit and method of operation thereof are provided, which enable operation with high efficiency always even when suction or discharge pressure fluctuates widely, the compressor unit comprising a combination of a compression stage provided with an unloader slide valve and that provided with an internal volume ratio control valve, or a combination of compression stage provided with an internal volume control valve and that of fixed internal volume ratio, or a combination of compression stages each provided with an internal volume control valve.

Abstract: This invention provides a novel D-aminoacylase obtained by cloning a DNA encoding the novel D-aminoacylase from Methylobacterium mesophilicum MT 10894, etc. and which shows sufficiently high activity at an industrially useful substrate concentration to allow a D-amino acid to be efficiently produced from an N-acyl-DL-amino acid; a DNA encoding the D-aminoacylase; a process for producing a D-amino acid from the corresponding N-acylamino acid using a transformant containing the DNA.

Abstract: The invention provides a method of operating a screw compressor equipment without reducing the efficiency, in which a screw compressor 1 of which the internal volume ratio is variable by means of an internal volume ratio control valve is driven by a driving machine 2, the discharge side of the compressor 1 is communicated with the suction side of the same by way of a bypass control valve 9 as needed, the internal volume ratio control valve 3 is always controlled to be located at a position calculated so that the internal volume ratio with which the polytropic efficiency is maximum is obtained, and gas flow rate is controlled by controlling the rotation speed under normal conditions and controlled by controlling the bypassing flow rate from the discharge side to the suction side under very low rotation speed.

Abstract: The optical recording medium includes at least a recording layer, a recording supplemental layer, a reflection layer and a protection layer on a light permeable substrate, each of the recording layer and the recording supplemental layer is made mainly of an organic pigment material, with the optical recording medium, recording and reproducing is possible using a laser beam having a wavelength of &lgr;1 and also recording and/or reproducing is possible using a laser beam having a wavelength of &lgr;2 which is shorter than &lgr;1, a spectral absorbance of the recording layer is in the range between 5% and 35% at a wavelength of &lgr;1 and not less than 15% at a wavelength of &lgr;2, and the recording supplemental layer has a peak of spectral reflectance at a wavelength in the vicinity of &lgr;2.

Abstract: An optical recording medium having a light absorption layer formed on a substrate having a spiral groove by means of the vacuum deposition and a reflective layer formed on the light absorption layer, wherein: (1) the groove of the substrate has a groove section of which cross section is a trapezoidal; (2) a ratio of a groove width (W) to a track pitch (TP) (W/TR) of the substrate falls within a range of 0.25 to 0.45; (3) a groove depth (D) is 20 to 80% of (&lgr;/4n) (wherein A is a wavelength of a laser beam, and n is a refractive index of the substrate); and (4) angles a1 and a2 formed by both side surfaces of the groove section and surfaces vertical to a groove bottom surface on cross lines between the both side surfaces of the groove section and the groove bottom surface are 45 to 80°, and a difference between a1 and a2 (a1−a2) is not more than ±10°.

Abstract: A heat exchanger is made of a metal such as aluminum and for use in the air conditioning apparatuses such as the car coolers and the room air conditioners. A coolant inlet pipe (6) has an end which is forced into a pipe insertion bore (10) of a pipe joint (8) for connection to an external piping, with a cylindrical brazing agent piece (15) being interposed between the outer periphery of the inlet pipe end and the inner peripheral wall of the bore, such that the pipe (6) is brazed integral to the joint (8) by means of the cylindrical piece (15). This cylindrical brazing agent piece (15) is composed of a core layer which has an outer and inner surfaces clad with a brazing agent layer. The pipe (6) and the joint (8) can be preassembled without failing to interpose between them the brazing agent piece (15), so that said pipe and said joint can be brazed one to another surely and at a lowered cost.

Abstract: A fluorene derivative of high purity is produced by reacting fluorenone with phenoxyethanol in the presence of a sulfuric acid-thiol catalyst system, dissolving the reaction mixture in a lower aliphatic alcohol and adding water to the resulting solution for precipitation of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene [fluorene derivative]. A fluorene derivative of still higher purity is obtained by recrystallization from a lower aliphatic alcohol.In accordance with this invention, a fluorene derivative can be produced advantageously on a commercial scale without incurring any appreciable loss of fluorenone, in good yield, with high efficiency and in a reduced production time.

Abstract: A semiconductor includes a conductor layer formed on one side thereof toward a first surface of a substrate, and a first interlayer insulation layer on the conductor layer. The first interlayer insulation layer has a first opening extending therethrough to the conductor layer. A first wiring layer is provided on the first interlayer insulation layer, and connected to the conductor layer via the first opening. A second interlayer insulation layer is formed on the first wiring layer and has a second opening extending through the first opening to the first wiring layer. A second wiring layer is formed on the second interlayer insulation layer and extends through the second interlayer to the first wiring layer and/or the conductor layer via the first opening and the second opening.

Abstract: A non-volatile semiconductor memory device is comprised of a floating gate electrode disposed on and electrically insulated from a semiconductor substrate for storing electric charge. A tunnel insulating film is disposed in contact with the floating gate electrode to inject and extract the electric charge to and from the floating gate electrode in the form of an electric tunnel current flowing through the tunnel insulating film. The tunnel insulating film is composed of silicon oxide chemically-vapor-deposited at a temperature between 700.degree. C. and 900.degree. C. from the vapor mixture of dichlorosilane and dinitrogen monoxide on the order of 100 .ANG. thickness to thereby establish a breakdown current density more than 1.0 A/cm.sup.2.