Abstract: A porous carbon material, a method for preparing the same, a positive electrode including the same, and a lithium-sulfur battery including the same are provided. The porous carbon material has a specific surface area of 200 to 1,700 m2/g and impurities therefrom are removed through pre-treatment using microwaves. The porous carbon material, when applied to the positive electrode of the lithium-sulfur battery, improves the charging overvoltage problem of the lithium-sulfur battery.

Abstract: An electronic device is provided. The electronic device includes a display module, at least one camera disposed on the rear surface of the display module, memory for storing information related to user authentication, and a processor operatively connected to the display module, the at least one camera, and the memory. The processor is configured to executes a function for the user authentication, identify face position information of a user by using the at least one camera, identify coordinate information according to a user's touch input inputted through the display module, select the at least one camera based on the face position information and the coordinate information, obtain at least one image using the selected at least one camera, and perform the function for the user authentication based on the obtained at least one image.

Abstract: Disclosed is a plasma generation apparatus which can efficiently generate plasma by using atmospheric air without separately supplying a gas for plasma generation, and is suitable for use in applications for skin care. A plasma generation apparatus according to an embodiment of the present invention comprises a plasma generation part including a plasma tip and configured to generate plasma within the plasma tip and deliver the plasma to an object. The plasma tip comprises: a tip body having an internal space in which the plasma is generated; an electrode part provided in the internal space within the tip body and configured such that power for generating the plasma is applied thereto; and an air inlet passage connecting an outer area of the tip body and the internal space so that air flows from the outer area of the tip body toward the electrode part.

Abstract: A switched-mode power supply including a primary rectifying circuit connected to an AC power supply, a transformer connected to the primary rectifying circuit, a secondary rectifying circuit connected to the secondary side of the transformer, a voltage fluctuation detector for sensing fluctuation in the output voltage, a signal generator for generating switching signals in response to the fluctuation detector, a switching tansistor for shunting the transformer to ground in response to the switching signals, a protective circuit responsive to the output voltage for stopping any abnormal operation of the switching signal generator, and an auxiliary power circuit for supplying power to the switching signal generator and to the protective circuit.