Abstract: A laser control method includes the steps of: using a laser control circuit which includes a constant current circuit that maintains a constant current flowing through a semiconductor laser element, and which includes an adder and a multiplier connected to a stage preceding the constant current circuit, and using detection means for calibration for detecting an applied laser output; calculating, on the basis of a detection signal output from the detection means, a reference bias value and a reference gain value for obtaining a specified laser output with respect to a specified input to the multiplier; inputting the reference bias value and the reference gain value to the adder and the multiplier, respectively; and controlling the applied laser output from the semiconductor laser element by performing calibration.

Abstract: A porous substrate with a seed crystal-containing layer for manufacturing a zeolite membrane includes: a ceramic porous substrate, and a seed crystal-containing layer containing a zeolite powder to function as a seed crystal for forming a zeolite membrane and a ceramic powder and being loaded on a surface of the ceramic porous substrate and fired to fix the seed crystal-containing layer on the porous substrate. The porous substrate with a seed crystal-containing layer used for manufacturing a zeolite membrane inhibits a defect such as a crack from being generated in the zeolite layer upon manufacture or use by manufacturing a zeolite membrane by the use of the substrate which then can be subjected to air-spraying, washing, and processing for the purpose of removing a foreign substance, etc., prior to hydrothermal synthesis.

Abstract: A dehydration method by which water is selectively separated from a water-containing mixture 31 with a separation membrane. The separation membrane is a DDR type zeolite membrane 2. The dehydration method includes bringing the mixture 31 into contact with one side of the DDR type zeolite membrane 2 and causing a pressure difference between that side of the DDR type zeolite membrane 2 which is in contact with the mixture and the other side of the DDR type zeolite membrane 2 to thereby cause the water to selectively permeate and separate out. By the dehydration method, water can be selectively separated from a water-containing mixture without the need of a high energy cost. The separation membrane has excellent acid resistance.

Abstract: A laser control method includes the steps of: using a laser control circuit which includes a constant current circuit that maintains a constant current flowing through a semiconductor laser element, and which includes an adder and a multiplier connected to a stage preceding the constant current circuit, and using detection means for calibration for detecting an applied laser output; calculating, on the basis of a detection signal output from the detection means, a reference bias value and a reference gain value for obtaining a specified laser output with respect to a specified input to the multiplier; inputting the reference bias value and the reference gain value to the adder and the multiplier, respectively; and controlling the applied laser output from the semiconductor laser element by performing calibration.

Abstract: A gas separator is provided, including a porous substrate made of a first ceramic and a gas-separating layer containing zeolite disposed on the surface of the porous substrate. The gas-separating layer further contains, in addition to zeolite, a thermal expansion coefficient-adjusting material made of a second ceramic having a linear thermal expansion coefficient satisfying a predetermined relationship, so that the difference between the thermal expansion coefficient of the porous substrate and the gas-separating layer can be reduced.

Abstract: A dehydration method by which water is selectively separated from a water-containing mixture 31 with a separation membrane. The separation membrane is a DDR type zeolite membrane 2. The dehydration method includes bringing the mixture 31 into contact with one side of the DDR type zeolite membrane 2 and causing a pressure difference between that side of the DDR type zeolite membrane 2 which is in contact with the mixture and the other side of the DDR type zeolite membrane 2 to thereby cause the water to selectively permeate and separate out. By the dehydration method, water can be selectively separated from a water-containing mixture without the need of a high energy cost. The separation membrane has excellent acid resistance.

Abstract: A method for producing a DDR type zeolite membrane, comprising immersing a porous substrate in a raw material solution containing 1-adamantanamine, silica, and water; and carrying out a hydrothermal synthesis of DDR type zeolite in the presence of a DDR type zeolite seed crystal (seed crystal) to form a DDR type zeolite membrane on the surface of the porous substrate by making a content ratio of 1-adamantanamine to silica (1-adamantanamine/silica) in the range of 0.002 to 0.4 in terms of molar ratio and a content ratio of water to silica (water/silica) in the range of 10 to 500 in terms of molar ratio, and an average particle diameter of the seed crystal to 300 nm or less to provide a method for producing stably a DDR type zeolite membrane of uniform and thin membrane thickness with high gas permeability.

Abstract: A porous substrate with a seed crystal-containing layer for manufacturing a zeolite membrane includes: a ceramic porous substrate, and a seed crystal-containing layer containing a zeolite powder to function as a seed crystal for forming a zeolite membrane and a ceramic powder and being loaded on a surface of the ceramic porous substrate and fired to fix the seed crystal-containing layer on the porous substrate. The porous substrate with a seed crystal-containing layer used for manufacturing a zeolite membrane can inhibit a defect such as a crack from being generated in the zeolite layer upon manufacture or use by manufacturing a zeolite membrane by the use of the substrate and can be subjected to air-spraying, washing, and processing for the purpose of removing a foreign substance, etc., prior to hydrothermal synthesis.

Abstract: The present invention discloses a gas separator comprising a porous substrate composed of a first ceramic and a gas-separating layer containing zeolite, disposed on the surface of the porous substrate, wherein the gas-separating layer contains, in addition to zeolite, a thermal expansion coefficient-adjusting material composed of a second ceramic having a linear thermal expansion coefficient satisfying a predetermined relation so that the difference in thermal expansion coefficient between the porous substrate and the gas-separating layer can be reduced. The gas separator of the present invention can be used preferably particularly in selective separation of carbon dioxide (CO2) or the like from a mixed gas such as natural gas or the like.

Abstract: A laser beam is obtained from a semiconductor laser by a stable emission light amount. A first semiconductor laser is thermally coupled with a second semiconductor laser and driven by a feedback circuit constructed by a photodetector, an I-V converter, and a current generator so as to stabilize the emission light amount. A current I0? having a correlation with a drive current I0 of the 1st laser is outputted from a current mirror circuit. A modulation signal is supplied to a current pull-in type current driving circuit via a multiplier and a linearity compensating circuit and a current I2 according to the modulation signal is extracted from a collector of a transistor. The 2nd laser is driven by a current I1 (I0??I2) and a laser beam modulated by the modulation signal is generated. Since the signal modulation by the 2nd laser is performed without influencing on I0 and the 2nd laser is driven by I0?, the emission light amount is stabilized.

Abstract: A DDR type zeolite membrane formed on a substrate includes silica as a main component. The DDR type zeolite membrane separates at least one type of a gas component from a mixed gas containing at least two types of gases selected from a group consisting of carbon dioxide (CO2), hydrogen (H2), oxygen (O2), nitrogen (N2), methane (CH4), normal butane (n-C4H10), isobutane (i-C4H10), sulfur hexafluoride (SF6), ethane (C2H6), ethylene (C2H4), propane (C3H8), propylene (C3H6), carbon monoxide (CO), and nitrogen monoxide (NO). Each single gas permeance at room temperature and 100° C. are different, respectively, in order to separate at least one selected gas component from the mixed gas.

Abstract: A DDR type zeolite membrane formed on a substrate includes silica as a main component. The DDR type zeolite membrane separates at least one type of a gas component from a mixed gas containing at least two types of gases selected from a group consisting of carbon dioxide (CO2), hydrogen (H2), oxygen (O2), nitrogen (N2), methane (CH4), normal butane (n-C4H10), isobutane (i-C4H10), sulfur hexafluoride (SF6), ethane (C2H6), ethylene (C2H4), propane (C3H8), propylene (C3H6), carbon monoxide (CO), and nitrogen monoxide (NO). Each single gas permeance at room temperature and 100° C. are different, respectively, in order to separate at least one selected gas component from the mixed gas.

Abstract: This invention provides a DDR type zeolite membrane, characterized in that it is formed as a membrane on a substrate and its main component is silica, and that each single gas permeance at room temperature and 100° C. are different, respectively among at least two types of gases selected from a group consisting of carbon dioxide (CO2), hydrogen (H2), oxygen (O2), nitrogen (N2), methane (CH4), normal butane (n-C4H10), isobutane (i-C4H10), sulfur hexafluoride (SF6), ethane (C2H6), ethylene (C2H4), propane (C3H8), propylene (C3H6), carbon monoxide (CO), and nitrogen monoxide (NO).

Abstract: This invention provides a DDR type zeolite membrane, characterized in that it is formed as a membrane on a substrate and its main component is silica, and that each single gas permeance at room temperature and 100° C. are different, respectively among at least two types of gases selected from a group consisting of carbon dioxide (CO2), hydrogen (H2), oxygen (O2), nitrogen (N2), methane (CH4), normal butane (n-C4H10), isobutane (i-C4H10), sulfur hexafluoride (SF6), ethane (C2H6), ethylene (C2H4), propane (C3H8), propylene (C3H6), carbon monoxide (CO), and nitrogen monoxide (NO).

Abstract: A laser beam is obtained from a semiconductor laser by a stable emission light amount. A first semiconductor laser is thermally coupled with a second semiconductor laser and driven by a feedback circuit constructed by a photodetector, an I-V converter, and a current generator so as to stabilize the emission light amount. A current I0′ having a correlation with a drive current I0 of the 1st laser is outputted from a current mirror circuit. A modulation signal is supplied to a current pull-in type current driving circuit via a multiplier and a linearity compensating circuit and a current I2 according to the modulation signal is extracted from a collector of a transistor. The 2nd laser is driven by a current I1 (I0′-I2) and a laser beam modulated by the modulation signal is generated. Since the signal modulation by the 2nd laser is performed without influencing on I0 and the 2nd laser is driven by I0′, the emission light amount is stabilized.

Abstract: A method for producing a zeolite composite membrane in which a zeolite membrane is formed on a porous substrate includes the steps of: coating a zeolite membrane on a porous substrate made of zeolite having the same or a similar composition as the zeolite membrane and containing the same template as the zeolite membrane; and calcining the porous substrate having the zeolite membrane thereon to remove the template from the zeolite membrane and the porous substrate at once. A zeolite composite membrane that does not have cracks can be obtained by almost equalizing thermal expansion coefficients of the porous substrate and the zeolite membrane.

Abstract: A method and message router that breaks up files to be transferred over a network connection within a specified deadline into fixed-sized pieces. Each piece contains enough redundant information so that a subset (but not all) of the pieces will be sufficient to construct the file at the destination. The method and router determine optimal values for the number of pieces the file should be split into and the subset of pieces required to reconstruct the full contents of the file in order to maximize the probability that the file can be reconstructed at the destination by the specified deadline. The method and router provide an expected QoS guarantee by using redundancy with a deadline rather than reservations.

Abstract: An optical recording disc on which an analog audio signal and a digital audio signal are recorded is tested. The analog audio signal results from FM-modulating 2-channel audio signals, and the digital audio signal results from modulating the same 2-channel audio signals in a digital fashion, in order to perform the test, a signal mixed with 2-channel audio signals resulting demodulating an analog audio signal and a signal mixed with 2-channel audio signals resulting from demodulating a digital audio signal are simultaneously reproduced by an electroacoustic transducer and evaluated.