Abstract: Disclosed is a vacuum cleaner. The vacuum cleaner according to the present disclosure includes a main body and a suction nozzle. The suction nozzle includes a housing and a rotating brush. The rotating brush includes a first rotating brush, a second rotating brush, and a coupler. The coupler couples the first rotating brush and the second rotating brush so that a rotation axis of the first rotating brush and a rotation axis of the second rotating brush are positioned on the same line.

Abstract: CROSS-REFERENCE TO RELATED APPLICATIONS This application is a National Phase Application under 35 U.S.C. § 371 of International Application No. PCT/KR2020/017380, filed on Dec. 1, 2020, which claims priority to Korean Application No. 10-2019-0159187, filed on Dec. 3, 2019. The disclosures of the prior applications are incorporated by reference in their entirety. A vacuum cleaner includes a main body and a suction nozzle. The suction nozzle includes a housing and a rotating brush. The rotating brush includes a first rotating brush, a second rotating brush, and a coupler. The coupler couples the first rotating brush and the second rotating brush so that a rotation axis of the first rotating brush and a rotation axis of the second rotating brush are positioned on the same line.

Abstract: A vacuum cleaner is disclosed. The vacuum cleaner according to the present disclosure includes a main body and a suction nozzle. The suction nozzle includes a main housing and a driver. The driver includes a motor and a transmission. The motor is provided behind a rotating brush. The transmission transfers rotational motion of the motor to the rotating brush.

Abstract: Disclosed is a vacuum cleaner. The vacuum cleaner according to the present disclosure includes a main body and a suction nozzle. The suction nozzle includes a housing and a rotating brush. The rotating brush includes a first rotating brush, a second rotating brush, and a coupler. The coupler couples the first rotating brush and the second rotating brush so that a rotation axis of the first rotating brush and a rotation axis of the second rotating brush are positioned on the same line.

Abstract: The present invention provides a method for preparing 2,4-dinitroimidazole, wherein separation of 1,4-donitroimidazole in powder form is avoided so that it is possible to eliminate allergy problems in workers and simplify the process, thereby improving process economy.

Abstract: The present invention provides a method for preparing 2,4-dinitroimidazole, wherein separation of 1,4-donitroimidazole in powder form is avoided so that it is possible to eliminate allergy problems in workers and simplify the process, thereby improving process economy.