Abstract: The present disclosure provides a composite wherein NaCl nanoparticles are uniformly dispersed on reduced graphene oxide (rGO), a positive electrode active material including the same, a sodium secondary battery including the same, and a method for preparing the same. The positive electrode active material according to the present disclosure has a structure wherein NaCl nanoparticles are uniformly dispersed on rGO in a one-step process through chemical self-assembly. Therefore, the positive electrode active material according to the present disclosure exhibits superior electrochemical properties with high capacity because the small NaCl particles are dispersed uniformly and is economically favorable because the preparation process is simple.

Abstract: The present disclosure provides a composite wherein NaCl nanoparticles are uniformly dispersed on reduced graphene oxide (rGO), a positive electrode active material including the same, a sodium secondary battery including the same, and a method for preparing the same. The positive electrode active material according to the present disclosure has a structure wherein NaCl nanoparticles are uniformly dispersed on rGO in a one-step process through chemical self-assembly. Therefore, the positive electrode active material according to the present disclosure exhibits superior electrochemical properties with high capacity because the small NaCl particles are dispersed uniformly and is economically favorable because the preparation process is simple.

Abstract: Sodium negative active material may have a metal phosphate having a uniform size distribution structures to graphene surface. The negative active material is a metal or a metal oxide precursor in a graphite dispersion solution; And the addition of phosphate, and then applying a microwave, can be produced by heat treatment.

Abstract: Sodium negative active material may have a metal phosphate having a uniform size distribution structures to graphene surface. The negative active material is a metal or a metal oxide precursor in a graphite dispersion solution; And the addition of phosphate, and then applying a microwave, can be produced by heat treatment.

Abstract: Method and system to detect orientations of a moving object using one or more magnetic compasses. The method and system minimize magnetic field interference in a space where an object is moving such that the orientations of the moving object can be precisely detected. The method includes setting one or more earth magnetic field (EMF) conditions without a magnetic field interference component to determine whether the one or more magnetic compasses are located in an EMF area, calculating a magnitude of a magnetic field applied to the moving object using the one or more magnetic field compasses, and detecting an orientation of the moving object by determining whether the calculated magnitude of the magnetic field satisfies the one or more EMF conditions.

Abstract: The present invention relates to a recording and storage means in digital STB (Set Top Box) and PVR (Personal Video Recorder) and method thereof The digital broadcast receiver for receiving real-time digital broadcast programs comprises: storage means for storing broadcast programs, being attachable and separable to and from a set by a user without taking the set apart; a coupling means for attachment and separation of the storage means to and from a main body of the broadcast receiver; and a connection means as a path for power supply of the storage means, and signal.