Abstract: A first gas sensor having a first sensor element includes a first protective cover that protects the first sensor element, and a second gas sensor having a second sensor element includes a second protective cover that protects the second sensor element. The first protective cover is coated with an oxidation catalyst for one target component from among a plurality of target components, and the second protective cover is coated with an inert catalyst for the one target component.

Abstract: In a gas sensor, which measures a measurement pump current Ip3 of a measurement chamber, while switching a preliminary pump cell of a preliminary chamber ON or OFF at a constant period, there are formed in communication with each other sequentially from a gas introduction port in the interior of a structural body made from a solid electrolyte, a preliminary chamber, an oxygen concentration adjustment chamber, and a measurement chamber. The gas sensor rapidly determines a steady-state value of a measurement pump current Ip3, based on a peak value of a rate of change over time dIp3/dt of the measurement pump current Ip3, thereby hastening an ON/OFF switching period of the preliminary pump cell.

Abstract: A first gas sensor having a first sensor element includes a first protective cover that protects the first sensor element, and a second gas sensor having a second sensor element includes a second protective cover that protects the second sensor element. The first protective cover is coated with an oxidation catalyst for one target component from among a plurality of target components, and the second protective cover is coated with an inert catalyst for the one target component.

Abstract: A gas sensor that measures concentrations of a first target component and a second target component includes a first switch that controls driving of a first preliminary adjustment pump cell to be turned ON or OFF, a second switch that controls driving of a second preliminary adjustment pump cell to be turned ON or OFF, and a switching control device that controls switching between the first switch and the second switch.

Abstract: A sensor element includes a NOx sensor part, a NH3 gas sensor part, and a single common electrode shared by the both parts. The former has a pump cell including a measurement electrode facing an internal space, a pump electrode formed on a surface of the element, and a solid electrolyte therebetween. The latter includes a sensing electrode formed on a surface of the element and having catalytic activity inactivated for a NH3 gas. The common electrode is located to be in contact with a reference gas. The NOx concentration is determined based on a potential difference occurring between the sensing electrode and the common electrode, and a current flowing through the pump cell in a state of controlling a voltage applied across the electrodes to maintain a potential difference between the measurement electrode and the common electrode constant.

Abstract: In a gas sensor, which measures a measurement pump current Ip3 of a measurement chamber, while switching a preliminary pump cell of a preliminary chamber ON or OFF at a constant period, there are formed in communication with each other sequentially from a gas introduction port in the interior of a structural body made from a solid electrolyte, a preliminary chamber, an oxygen concentration adjustment chamber, and a measurement chamber. The gas sensor rapidly determines a steady-state value of a measurement pump current Ip3, based on a peak value of a rate of change over time dIp3/dt of the measurement pump current Ip3, thereby hastening an ON/OFF switching period of the preliminary pump cell.

Abstract: Provided is a gas sensor having simpler configuration than a conventional multi-gas sensor, and being capable of measuring NOx and NH3 simultaneously. In the gas sensor determining a NOx concentration in a measurement gas based on a pump current flowing between a NOx measurement electrode and an outer pump electrode, the outer pump electrode has catalytic activity inactivated for NH3 so that a sensor element further includes a NH3 sensor part having a mixed potential cell constituted by the outer pump electrode, a reference electrode, and a solid electrolyte between these electrodes, and determination of a NH3 concentration based on a potential difference occurring between the outer pump electrode and the reference electrode and determination of a NOx concentration based on the pump current and the NH3 concentration can be performed simultaneously or selectively when the sensor element is heated to 400° C. or higher and 600° C. or lower.

Abstract: A slope ?t1HC in a linear area of sensor output characteristics for a mixed atmosphere of CO and THC and a slope ?t1NH in the linear area of the sensor output characteristics for NH3 are specified in advance at a time when a time t1 has elapsed since a start of use of an engine. In performing calibration of an NH3 sensor when a time t2 (greater than the time t1) has elapsed, a slope ?t2HC in the linear area of the sensor output characteristics for the mixed atmosphere is specified, a value ?t2NH is calculated from an equation ?t2NH=?t2HC/(?t1HC/?t1NH), and the calculated value ?t2NH is determined as a new slope in the linear area of the sensor output characteristics for an NH3 gas.

Abstract: A slope ?t1HC in a linear area of sensor output characteristics for a mixed atmosphere of CO and THC and a slope ?t1NH in the linear area of the sensor output characteristics for NH3 are specified in advance at a time when a time t1 has elapsed since a start of use of an engine. In performing calibration of an NH3 sensor when a time t2 (greater than the time t1) has elapsed, a slope ?t2HC in the linear area of the sensor output characteristics for the mixed atmosphere is specified, a value ?t2NH is calculated from an equation ?t2NH=?t2HC/(?t1HC/?t1NH), and the calculated value ?t2NH is determined as a new slope in the linear area of the sensor output characteristics for an NH3 gas.

Abstract: Provided is a gas sensor having simpler configuration than a conventional multi-gas sensor, and being capable of measuring NOx and NH3 simultaneously. In the gas sensor determining a NOx concentration in a measurement gas based on a pump current flowing between a NOx measurement electrode and an outer pump electrode, the outer pump electrode has catalytic activity inactivated for NH3 so that a sensor element further includes a NH3 sensor part having a mixed potential cell constituted by the outer pump electrode, a reference electrode, and a solid electrolyte between these electrodes, and determination of a NH3 concentration based on a potential difference occurring between the outer pump electrode and the reference electrode and determination of a NOx concentration based on the pump current and the NH3 concentration can be performed simultaneously or selectively when the sensor element is heated to 400° C. or higher and 600° C. or lower.

Abstract: In a gas sensor determining a NOx concentration in a measurement gas based on a pump current flowing between a NOx measurement electrode and an outer pump electrode, the outer pump electrode has catalytic activity inactivated for HC and CO, so that a sensor element further includes a HC sensor part having a mixed potential cell constituted by the outer pump electrode, a reference electrode, and a solid electrolyte between these electrodes, and a HC mode for determining a HC concentration in the measurement gas based on a potential difference between the outer pump electrode and the reference electrode when the sensor element is heated to a temperature which is 400° C. or higher and 650° C. or lower and a NOx mode for determining a NOx concentration in the measurement gas based on the pump current can selectively be performed based on the temperature of the sensor element.

Abstract: A sensor element includes a NOx sensor part, a NH3 gas sensor part, and a single common electrode shared by the both parts. The former has a pump cell including a measurement electrode facing an internal space, a pump electrode formed on a surface of the element, and a solid electrolyte therebetween. The latter includes a sensing electrode formed on a surface of the element and having catalytic activity inactivated for a NH3 gas. The common electrode is located to be in contact with a reference gas. The NOx concentration is determined based on a potential difference occurring between the sensing electrode and the common electrode, and a current flowing through the pump cell in a state of controlling a voltage applied across the electrodes to maintain a potential difference between the measurement electrode and the common electrode constant.

Abstract: A method for manufacturing a silica membrane filter includes performing, at least once, a fired membrane forming operation having a membrane forming step of applying, to a porous substrate, a precursor sol which is a sol of a silicon alcoxide including a p-tolyl group to form a precursor sol membrane, a drying step of drying the precursor sol membrane formed in the porous substrate to form a dried membrane, and a firing step of firing the dried membrane formed in the porous substrate to form a fired membrane, thereby preparing the silica membrane filter including the porous substrate and a silica membrane which is the fired membrane formed in the porous substrate, and a ratio of a total mass of the silica membrane to a total mass of the dried membrane is 38 mass % or more and 85 mass % or less.

Abstract: A method for manufacturing a silica membrane filter includes performing, at least once, a fired membrane forming operation having a membrane forming step of applying, to a porous substrate, a precursor sol which is a sol of a silicon alcoxide including a p-tolyl group to form a precursor sol membrane, a drying step of drying the precursor sol membrane formed in the porous substrate to form a dried membrane, and a firing step of firing the dried membrane formed in the porous substrate to form a fired membrane, thereby preparing the silica membrane filter including the porous substrate and a silica membrane which is the fired membrane formed in the porous substrate, and a ratio of a total mass of the silica membrane to a total mass of the dried membrane is 38 mass % or more and 85 mass % or less.

Abstract: There is provided a silica membrane filter having performance of selectively separating an aromatic compound and performance of selectively separating an alcohol. The silica membrane filter is provided with a porous substrate and a silica membrane. The ratio of a He gas permeation amount to an N2 gas permeation amount (He gas permeation amount/N2 gas permeation amount) is 7 or less, and the ratio of the N2 gas permeation amount to a SF6 gas permeation amount (N2 gas permeation amount/SF6 gas permeation amount) is 1.5 or more.

Abstract: There is provided a zeolite separation membrane-provided article having gaps or pores larger than pores inherent to zeolite crystals and controlled within an appropriate range and being capable of achieving both high permeability and high separability for components with small difference in adsorption properties or a component having a smaller molecular diameter than the diameter of the pores, a method for producing the same, a method for separating mixed fluids, and a device for separating mixed fluids. The zeolite separation membrane-provided article is provided with a zeolite membrane having an N2 gas permeation speed at room temperature of 1.0×10?6 mol·m?2·s?1·Pa?1 or more and a permeation speed ratio of 1,3,5-trimethylbenzene/N2 at room temperature of 0.17 or more and being free from dyeing caused by the impregnation with Rhodamine B.

Abstract: A method for producing a carbon membrane of the present invention is a production method where a carbon membrane obtained by subjecting a carbon-containing layer to thermal decomposition in an oxygen inert atmosphere while sending a gas mixture containing an oxidizing gas thereinto is thermally heated. The carbon membrane is subjected to a heating oxidation treatment with controlling the ratio of the flow rate of the gas mixture to the areas of the carbon membrane to 0.5 cm/min. or more to control (temperature ° C.)2×time (h)/10000, which is the relation between the temperature of the gas mixture and the flow time, to 9 to 32. This enables to obtain a carbon film which selectively separates alcohols having 2 or less carbon atoms from a liquid mixture of the alcohols having 2 or less carbon atoms and organic compounds having 5 to 9 carbon atoms.

Abstract: A method for producing a carbon membrane of the present invention is a production method where a carbon membrane obtained by subjecting a carbon-containing layer to thermal decomposition in an oxygen inert atmosphere while sending a gas mixture containing an oxidizing gas thereinto is thermally heated. The carbon membrane is subjected to a heating oxidation treatment with controlling the ratio of the flow rate of the gas mixture to the areas of the carbon membrane to 0.5 cm/min. or more to control (temperature ° C.)2×time (h)/10000, which is the relation between the temperature of the gas mixture and the flow time, to 9 to 32. This enables to obtain a carbon film which selectively separates alcohols having 2 or less carbon atoms from a liquid mixture of the alcohols having 2 or less carbon atoms and organic compounds having 5 to 9 carbon atoms.

Abstract: There is disclosed a permselective membrane reactor which efficiently forms hydrogen by use of a water-gas shift reaction and which is excellent in an aspect of manufacturing cost. In a permselective membrane reactor, a permselective membrane is a Pd membrane or a Pd alloy membrane, and a catalyst layer includes a first catalyst layer on the side of the permselective membrane and a second catalyst layer disposed apart from the permselective membrane. The first catalyst layer has a noble metal-based catalyst, and the second catalyst layer has an iron-based catalyst.

Abstract: There is provided a zeolite separation membrane-provided article having gaps or pores larger than pores inherent to zeolite crystals and controlled within an appropriate range and being capable of achieving both high permeability and high separability for components with small difference in adsorption properties or a component having a smaller molecular diameter than the diameter of the pores, a method for producing the same, a method for separating mixed fluids, and a device for separating mixed fluids. The zeolite separation membrane-provided article is provided with a zeolite membrane having an N2 gas permeation speed at room temperature of 1.0×10?6 mol·m?2·s?1·Pa?1 or more and a permeation speed ratio of 1,3,5-trimethylbenzene/N2 at room temperature of 0.17 or more and being free from dyeing caused by the impregnation with Rhodamine B.