Semiconductor devices and methods of manufacture thereof are disclosed. The present invention relates to a production method of a pyridine derivative having a substituent at the 2-position of a heterocyclic structure, which is represented by the formula, which includes reacting a 2-sulfonylpyridine derivative of the formula with an organometallic compound of the formula and the like, and the like:wherein each symbol is as defined in the Description. A first flow path within the single, common recuperator section is configured to receive compressed air produced by the compressor section of each gas turbine engine. The electrochemical impedance Z of the system studied is determined and its SoC is estimated using the model applied to electrochemical impedance Z. A shut-off valve assembly automatically blocks fluid flow through the shunt in response to injection of the fluid into the arterial access device.