Abstract: A friction stir spot welding method performs friction stir spot welding of a pair of workpieces having a coating film formed on at least one welding surface by using a refill friction stir spot welding device including rotary tools. The method includes removing the coating film by plunging a distal end of the shoulder member into one workpiece up to a position closer to the surface than the welding surface, while rotating the shoulder member as a rotary tool around the axis, and rotating the shoulder member in a state in which the surface of one of the pair of workpieces, with the welding surfaces being overlaid on each other, is pressed by the end face of the clamp member and performing friction stir spot welding of the pair of workpieces after the coating film removal by using the pin member and the shoulder member as rotary tools.

Abstract: A current collector monitoring system in one aspect of the present disclosure is provided with: a collected current measurement unit; a collected current state determination unit; an image acquisition unit; an event recognition unit; an event determination unit; and a determination result output unit. When a state of collected current corresponds to an abnormal state, the image acquisition unit acquires an image including, within an angle of view, a collector shoe provided to a current collector.

Abstract: A friction stir spot welding method performs friction stir spot welding of a pair of workpieces having a coating film formed on at least one welding surface by using a refill friction stir spot welding device including rotary tools. The method includes removing the coating film by plunging a distal end of the shoulder member into one workpiece up to a position closer to the surface than the welding surface, while rotating the shoulder member as a rotary tool around the axis, and rotating the shoulder member in a state in which the surface of one of the pair of workpieces, with the welding surfaces being overlaid on each other, is pressed by the end face of the clamp member and performing friction stir spot welding of the pair of workpieces after the coating film removal by using the pin member and the shoulder member as rotary tools.

Abstract: A power conversion system includes a transformer, a power conversion device for travel, a power conversion device for auxiliary power sources, an electrical storage device, and an auxiliary device. The power conversion device for travel converts AC power into power for travel and supplies it to a travel motor. The power conversion device for auxiliary power sources includes an AC to DC conversion unit which converts AC power into DC power, a power conversion unit for AC loads which converts the DC power into AC power and supplies it to an AC load, and a power conversion unit for DC loads which converts DC power to DC power and supplies it to a DC load. The electrical storage device is connected to power lines connecting DC power output terminals of the AC to DC conversion unit and DC power input terminals of both the power conversion units for AC and DC loads.

Abstract: A current collector monitoring system in one aspect of the present disclosure is provided with: a collected current measurement unit; a collected current state determination unit; an image acquisition unit; an event recognition unit; an event determination unit; and a determination result output unit. When a state of collected current corresponds to an abnormal state, the image acquisition unit acquires an image including, within an angle of view, a collector shoe provided to a current collector.

Abstract: A saccharified solution production method includes: a saccharifying step of saccharifying hemicellulose or cellulose contained in cellulosic biomass to C5 or C6 saccharides by subjecting a slurry of cellulosic biomass to a hot water treatment in a supercritical state or subcritical state; a washing step of successively washing a solid in the slurry with washing water after the saccharifying step, by using multiple stages of thickeners for washing arranged in series so that the direction of movement of the solid in the slurry and the direction of movement of overflow water are opposite to each other; and a concentration step of removing a solid residue from the washing water recovered in the washing step by using a thickener for still standing that is different from the thickeners for washing, and then concentrating a supernatant of the thickener for still standing by using a concentration device to give a saccharified solution.

Abstract: A power conversion system includes a transformer, a power conversion device for travel, a power conversion device for auxiliary power sources, an electrical storage device, and an auxiliary device. The power conversion device for travel converts AC power into power for travel and supplies it to a travel motor. The power conversion device for auxiliary power sources includes an AC to DC conversion unit which converts AC power into DC power, a power conversion unit for AC loads which converts the DC power into AC power and supplies it to an AC load, and a power conversion unit for DC loads which converts DC power to DC power and supplies it to a DC load. The electrical storage device is connected to power lines connecting DC power output terminals of the AC to DC conversion unit and DC power input terminals of both the power conversion units for AC and DC loads.

Abstract: A compressed air supply apparatus includes a control unit configured to operate an air compressor when a measurement value of a pressure measurement unit reaches a first pressure or less, and configured to stop the air compressor when the measurement value reaches a second pressure higher than the first pressure, and a plurality of relief valve apparatuses installed in each of the connection flow path between the air compressor and each of a plurality of air tanks, wherein each of the plurality of relief valve apparatuses is configured to open the connection flow path to the atmosphere when the measurement value reaches a third pressure higher than the second pressure and close the connection flow path when the measurement value reaches a fourth pressure higher than the second pressure and lower than the third pressure after the opening.

Abstract: A saccharified solution production method includes: a saccharifying step of saccharifying hemicellulose or cellulose contained in cellulosic biomass to C5 or C6 saccharides by subjecting a slurry of cellulosic biomass to a hot water treatment in a supercritical state or subcritical state; a washing step of successively washing a solid in the slurry with washing water after the saccharifying step, by using multiple stages of thickeners for washing arranged in series so that the direction of movement of the solid in the slurry and the direction of movement of overflow water are opposite to each other; and a concentration step of removing a solid residue from the washing water recovered in the washing step by using a thickener for still standing that is different from the thickeners for washing, and then concentrating a supernatant of the thickener for still standing by using a concentration device to give a saccharified solution.

Abstract: A compressed air supply apparatus includes a control unit configured to operate an air compressor when a measurement value of the pressure measurement unit reaches a first pressure or less, and configured to stop the air compressor when the measurement value reaches a second pressure higher than the first pressure, and a plurality of relief valve apparatuses installed in each of the connection flow path between the air compressor and each of a plurality of air tanks, wherein the relief valve apparatus configures to open the connection flow path to the atmosphere when the measurement value reaches a third pressure higher than the second pressure and close the connection flow path when the measurement value reaches a fourth pressure higher than the second pressure and lower than the third pressure after the opening.

Abstract: An object of the invention is to provide an inexpensive and efficient ethanol production method using lignocellulosic biomass as a raw material. The method for producing ethanol from lignocellulosic biomass of the present invention includes a lignocellulose decomposition step of subjecting lignocellulosic biomass to a steam explosion treatment or hydrolysis in a subcritical state followed by a flash treatment; a lignin removal step of immersing a solid residue resulting from the decomposition step in ethanol to remove lignin; and a C6 saccharification/simultaneous fermentation step of saccharifying the solid residue resulting from the lignin removal step with an enzyme and further fermenting the resulting product into ethanol with a C6 fermentation microorganism. By combining the steam explosion treatment and the lignin removal process by ethanol immersion, higher rates are achieved for the saccharification and fermentation of the biomass.