Abstract: A hollow fiber membrane including a dense layer at least on an inner surface side of the hollow fiber membrane, in which when the inner surface of the hollow fiber membrane is observed under an atomic force microscope, a plurality of groove-like recesses oriented in a lengthwise direction of the hollow fiber membrane are observed, an aspect ratio defined as a ratio of a length to a width of each of the recesses is greater than or equal to 3 and less than or equal to 30, a yield strength of the hollow fiber membrane in a dry state is greater than or equal to 30 g/filament, and a breaking elongation is less than or equal to 20%/filament.

Abstract: The present invention provides a hollow fiber membrane including a cellulose acetate-based polymer, in which when an inner surface of the hollow fiber membrane is observed under an atomic force microscope, a plurality of groove-like recesses oriented in a lengthwise direction of the hollow fiber membrane are observed, an average length of the recesses is greater than or equal to 200 nm and less than or equal to 500 nm, an average width of the recesses is greater than or equal to 15 nm and less than or equal to 50 nm, and an aspect ratio defined as a ratio of the average length to the average width of each of the recesses is greater than or equal to 6 and less than or equal to 22.

Abstract: A hollow fiber membrane including a dense layer at least on an inner surface side of the hollow fiber membrane, in which when the inner surface of the hollow fiber membrane is observed under an atomic force microscope, a plurality of groove-like recesses oriented in a lengthwise direction of the hollow fiber membrane are observed, an aspect ratio defined as a ratio of a length to a width of each of the recesses is greater than or equal to 3 and less than or equal to 30, a yield strength of the hollow fiber membrane in a dry state is greater than or equal to 30 g/filament, and a breaking elongation is less than or equal to 20%/filament.

Abstract: The present invention provides a hollow fiber membrane including a cellulose acetate-based polymer, in which when an inner surface of the hollow fiber membrane is observed under an atomic force microscope, a plurality of groove-like recesses oriented in a lengthwise direction of the hollow fiber membrane are observed, an average length of the recesses is greater than or equal to 200 nm and less than or equal to 500 nm, an average width of the recesses is greater than or equal to 15 nm and less than or equal to 50 nm, and an aspect ratio defined as a ratio of the average length to the average width of each of the recesses is greater than or equal to 6 and less than or equal to 22.

Abstract: A residual magnetic flux measurement apparatus measures residual magnetic fluxes by using a transformer-voltage measurement means for measuring transformer voltages; a voltage delay means for delaying the measured signals; a DC-voltage-component calculation means for calculating DC voltage components from the latest transformer-voltage signals for a predetermined time period based on calculation-control signals; a voltage integration means for calculating voltage-integration signals by performing voltage integration of signals obtained after separating the DC voltage components from present transformer-voltage signals; a magnetic-flux DC-component calculation means for calculating magnetic-flux DC-components from the latest voltage-integration signals for a predetermined time period based on the calculation-control signals; a magnetic flux calculation means for obtaining magnetic flux signals in which the magnetic-flux DC-components are separated from present voltage-integration signals; and a control means f

Abstract: A gas circuit breaker includes a grounded tank corresponding to each one of the plurality of phases, a bushing, an upper housing, and a lower housing, those mounted on a base that is supported by a frame. The grounded tank and the upper housing are located on a plane. The lower housing is connected to the grounded tank with a connecting unit such that the lower housing can be moved from a first position for operation lower than the plane to a second position for transportation substantially on the plane.

Abstract: A gas-circuit breaker includes a cylinder, a stationary piston, and a moving piston. The cylinder has a moving contact that is fixed on one end of a rod and has a gas exhaust that faces a stationary contact. The rod is inserted into the cylinder. The stationary piston is fixed to the container, and is fitted in an opening of the cylinder to create a puffer chamber. Due to movement of the rod, the stationary piston compresses arc-extinguishing gas, and the gas blows onto the arc through gas exhaust. The moving piston partitions the puffer chamber into a first puffer chamber and a second puffer chamber. Sliding of the moving piston changes the capacity of the first puffer chamber and the second puffer chamber according to the difference in pressure in the first puffer chamber and the second puffer chamber.

Abstract: A target-closing phase-map generating section generates in advance a target closing phase map in consideration of a pre-arc characteristic and variations of a mechanical action of a breaker, and amplitude fluctuations of the load voltage. A target-closing time calculating section calculates a target closing time string from frequencies and phases of the power source voltage and the load voltage, respectively, of the breaker referring to the target closing phase map. A closing control section, when a close command 11 is inputted, controls the timing of outputting a closing control signal based on a predicted closing time and the target closing time string.

Abstract: This invention provides a polyester and a polyester molded product, which, while maintaining color tone, transparency, and thermal stability, can realize a high polycondensation rate, are less likely to cause the production of polycondensation catalyst-derived undesired materials, and can simultaneously meet both quality and cost effectiveness requirements, which can exhibit the characteristic features, for example, in the fields of ultrafine fibers, high transparent films for optical use, or ultrahigh transparent molded products. These advantages can be realized by using, in the production of a polyester in the presence of an aluminum compound-containing polyester polycondensation catalyst, an aluminum compound having an absorbance of not more than 0.0132 as measured in the form of an aqueous aluminum compound solution, prepared by dissolving the aluminum compound in pure water to give a concentration of 2.

Abstract: A puffer-type gas blast circuit breaker is capable of restraining reduction in creepage insulation resistance of an insulating support and an insulating rod due to insulating gas of high temperature. An electrode section is mounted on a stationary member supported on an insulating support, and a stationary side arc contact and moving side arc contact are disposed facing each other to contact and separate; a hollow piston rod and an insulating rod are connected to the moving side arc contact, and inserted in a stationary member body portion; and a gas flow blocking member is mounted on an end of the piston rod to prevent an insulating gas heated and coming to the stationary side from getting into the insulating rod side. The stationary member body portion is formed cylindrical so that a gap between the body portion of the stationary member and the gas flow blocking member is minimized.

Abstract: A residual magnetic flux measurement apparatus measures residual magnetic fluxes by using a transformer-voltage measurement means for measuring transformer voltages; a voltage delay means for delaying the measured signals; a DC-voltage-component calculation means for calculating DC voltage components from the latest transformer-voltage signals for a predetermined time period based on calculation-control signals; a voltage integration means for calculating voltage-integration signals by performing voltage integration of signals obtained after separating the DC voltage components from present transformer-voltage signals; a magnetic-flux DC-component calculation means for calculating magnetic-flux DC-components from the latest voltage-integration signals for a predetermined time period based on the calculation-control signals; a magnetic flux calculation means for obtaining magnetic flux signals in which the magnetic-flux DC-components are separated from present voltage-integration signals; and a control means f

Abstract: A target-closing phase-map generating section generates in advance a target closing phase map in consideration of a pre-arc characteristic and variations of a mechanical action of a breaker, and amplitude fluctuations of the load voltage. A target-closing time calculating section calculates a target closing time string from frequencies and phases of the power source voltage and the load voltage, respectively, of the breaker referring to the target closing phase map. A closing control section, when a close command 11 is inputted, controls the timing of outputting a closing control signal based on a predicted closing time and the target closing time string.

Abstract: A gas circuit breaker includes a grounded tank corresponding to each one of the plurality of phases, a bushing, an upper housing, and a lower housing, those mounted on a base that is supported by a frame. The grounded tank and the upper housing are located on a plane. The lower housing is connected to the grounded tank with a connecting unit such that the lower housing can be moved from a first position for operation lower than the plane to a second position for transportation substantially on the plane.

Abstract: This invention provides a polyester and a polyester molded product, which, while maintaining color tone, transparency, and thermal stability, can realize a high polycondensation rate, are less likely to cause the production of polycondensation catalyst-derived undesired materials, and can simultaneously meet both quality and cost effectiveness requirements, which can exhibit the characteristic features, for example, in the fields of ultrafine fibers, high transparent films for optical use, or ultrahigh transparent molded products. These advantages can be realized by using, in the production of a polyester in the presence of an aluminum compound-containing polyester polycondensation catalyst, an aluminum compound having an absorbance of not more than 0.0132 as measured in the form of an aqueous aluminum compound solution, prepared by dissolving the aluminum compound in pure water to give a concentration of 2.

Abstract: A gas-circuit breaker includes a cylinder, a stationary piston, and a moving piston. The cylinder has a moving contact that is fixed on one end of a rod and has a gas exhaust that faces a stationary contact. The rod is inserted into the cylinder. The stationary piston is fixed to the container, and is fitted in an opening of the cylinder to create a puffer chamber. Due to movement of the rod, the stationary piston compresses arc-extinguishing gas, and the gas blows onto the arc through gas exhaust. The moving piston partitions the puffer chamber into a first puffer chamber and a second puffer chamber. Sliding of the moving piston changes the capacity of the first puffer chamber and the second puffer chamber according to the difference in pressure in the first puffer chamber and the second puffer chamber.

Abstract: The gas insulated switchgear includes a rotary shaft which penetrates a pressure vessel is connected with a moving part which is housed in the pressure vessel by way of a lever, and is connected to the moving part, and brackets which support the rotary shaft and are mounted on a mounting portion which is formed on the pressure vessel. The brackets are fixed to the mounting portion formed on the pressure vessel using a plurality of fixing bolts which are arranged in a spaced-apart manner on an eccentric circle having the center at a point x2 offset from the center of rotation x1 of a rotary shaft and hence, the brackets can be fixed to the mounting portion formed on the pressure vessel at a predetermined angular position which uses the point x2 offset from the center of rotation x1 of the rotary shaft as the center of rotation.

Abstract: A puffer-type gas blast circuit breaker is capable of restraining reduction in creepage insulation resistance of an insulating support and an insulating rod due to insulating gas of high temperature. An electrode section is mounted on a stationary member supported on an insulating support, and a stationary side arc contact and moving side arc contact are disposed facing each other to contact and separate; a hollow piston rod and an insulating rod are connected to the moving side arc contact, and inserted in a stationary member body portion; and a gas flow blocking member is mounted on an end of the piston rod to prevent an insulating gas heated and coming to the stationary side from getting into the insulating rod side. The stationary member body portion is formed cylindrical so that a gap between the body portion of the stationary member and the gas flow blocking member is minimized.

Abstract: Respective contact terminals in respective arc-suppressing spaces of respective breakers are opened at a voltage zero point of any phase of three phases, simultaneously among the three phases. If current breaking is carried out for the three phases at the same time, when the breakers of the three phases are opened, the residual magnetic levels of the respective phases of a transformer can be controlled so that the residual magnetic flux level of the phase opened at the voltage zero point is maximum (for example, ?2K or +2K) and the residual magnetic flux level of the other two phases are opposite in polarity to the residual magnetic flux level of the phase concerned and equal to substantially the same residual magnetic flux (for example, +K and +K or ?K and ?K) which is equal to about one half of the residual magnetic flux level of the phase concerned.

Abstract: The gas insulated switchgear includes a rotary shaft which penetrates a pressure vessel is connected with a moving parts which is housed in the pressure vessel by way of a lever, and is connected to the moving parts, and brackets which support the rotary shaft and are mounted on a mounting portion which is formed on the pressure vessel. The brackets are fixed to the mounting portion formed on the pressure vessel using a plurality of fixing bolts which are arranged in a spaced-apart manner on an eccentric circle having the center at a point x2 offset from the center of rotation x1 of a rotary shaft and hence, the brackets can be fixed to the mounting portion formed on the pressure vessel at a predetermined angular position which uses the point x2 offset from the center of rotation x1 of the rotary shaft as the center of rotation.

Abstract: A closing phase that produces the smallest energization flux error at a connection input point is calculated based upon a residual flux of the first closing phase and the preliminarily given pre-arc characteristic and closing time deviation characteristic of a three-phase circuit breaker, so that the calculated phase value is set as a target closing phase of the first closing phase. A closing phase that produces the smallest energization flux error when a residual flux of zero is calculated, so that the calculated phase value is set as a target closing phase of the remaining two phases. The total time required from the reference point to the target closing phases of the remaining two phases and a delay time corresponding to an integer multiple of a given cycle of the three-phase power supply is set as a target closing time of the remaining two phases.