Abstract: Proposed is a precursor composition for forming a metal film including a zirconium compound represented by any one of Chemical Formulas 1 to 3 and a hafnium compound represented by any one of Chemical Formulas 4 to 6.

Abstract: Provided is a centrifugal compressor having improved operation performance to improve durability. The centrifugal compressor includes an impeller connected to a rotary shaft and configured to radially eject a fluid suctioned in an axial direction upon rotation thereof; a shroud configured to cover front and rear sides of the impeller and having a suction port formed to face one surface of the impeller at a center of one side thereof; a volute chamber formed at an outer periphery of the shroud in a circumferential direction thereof and configured to guide the fluid ejected by the impeller to an ejection port; and a regulator installed at one side of the shroud and configured to selectively communicate a space formed at the other surface of the impeller with the outside.

Abstract: Provided is a centrifugal compressor having improved operation performance to improve durability. The centrifugal compressor includes an impeller connected to a rotary shaft and configured to radially eject a fluid suctioned in an axial direction upon rotation thereof; a shroud configured to cover front and rear sides of the impeller and having a suction port formed to face one surface of the impeller at a center of one side thereof; a volute chamber formed at an outer periphery of the shroud in a circumferential direction thereof and configured to guide the fluid ejected by the impeller to an ejection port; and a regulator installed at one side of the shroud and configured to selectively communicate a space formed at the other surface of the impeller with the outside.

Abstract: Disclosed is a fluid pump comprising: a camshaft eccentrically connected to a rotating shaft of a motor to be eccentrically rotated by rotation of the motor; a rotor coupled to three crankshafts to revolve along a predetermined orbit by eccentric rotation of the camshaft, the rotor having a concave groove which is formed in a radial direction; an outer casing cooperating with the rotor to define a first fluid chamber between an outer wall of the rotor and the outer casing, the outer casing having a pair of fluid passages which are defined at both sides of a guide bank to allow fluid to be sucked and discharged therethrough, respectively; a side cover coupled to the outer casing to define a body of the fluid pump; an inner casing integrally formed with the side cover, the inner casing cooperating with the rotor to define a second fluid chamber between an inner wall of the rotor and the inner casing; the three crankshafts disposed in the outer casing and locked to the rotor inside of the inner wall of the rotor