Abstract: The present invention relates to a nonwoven fabric or nonwoven composite material comprising the nonwoven fabric for shielding and absorbing electromagnetic waves, manufactured by using a carbon fiber plated with metal (copper and nickel) produced in an electroless or electrolysis continuous process. The nonwoven fabric of the present invention is thinner and stronger than the conventional art, and has an advantage of being capable of controlling conductivity by controlling only the content of the carbon fiber plated with metal, without need for further addition of conductive powder.

Abstract: The present invention relates to a preparation method for an electromagnetic wave shield composite material and the electromagnetic wave shield composite material prepared by the method. The present invention uses a highly conductive carbon fiber prepared by electroless and electrolytic continuous processes, and thus is suitable for an EMI shield due to having an excellent conductivity and low surface resistance, and is capable of providing the electromagnetic wave shield composite material having an excellent productivity and economic value. Furthermore, the electromagnetic wave shield composite material of the present invention can be used for blocking electromagnetic waves by being inserted into a cell phone cover and a cell phone pouch, and can also be applied to a bracket for protecting an LCD of a portable display product.

Abstract: The present invention relates to an apparatus and a method for transmitting wireless power, and more particularly, to an apparatus and a method for transmitting wireless power that rapidly and precisely adjusts impedance so as to transmit desired power. Disclosed an apparatus for transmitting wireless power that performs wireless power transmission, including: an oscillator; an amplifier; an impedance matcher including a matching network which adjusts impedance according to a digital control signal and an analog signal, a sensor, a digital controller which outputs a digital control signal, and generates an analog control start signal when adjustment of the impedance by the digital control signal is completed, and an analog controller which outputs the analog control signal, and a transmitting antenna which radiates the magnetic field by using the transmission power.

Abstract: A method of forming an SiC or SiC/Si3N4 coating layer on a bare graphite substrate via a solid-vapor process is disclosed. Synthesis of the SiC coating layer on the graphite substrate is accomplished by reaction of SiO vapor and carbon (C) of the graphite, and that of the SiC/Si3N4 coating layer is accomplished by reaction of SiO vapor, N2 and C of the graphite. Thickness of the SiC coating layer is affected by porosity of the graphite substrate, reaction temperature, and dwell time. By controlling the reaction temperature, hardness of the SiC coating may be increased to 10-15 times that of the bare graphite substrate. The SiC/Si3N4 coating is much thinner than the SiC coating and has a higher surface hardness. Thermal oxidation tests show that the SiC or SiC/Si3N4 coated substrate exhibits improved oxidation resistance over bare substrates. In particular, the SiC/Si3N4 coated substrate shows outstanding resistance to thermal oxidation.