Abstract: There is provided a frequency Selective Surface (FSS) structure for multi frequency bands configured with unit cells, each including a loop unit, arranged at regular intervals, wherein each unit cell includes: a dielectric layer; and the loop unit having a fixed width and formed on the dielectric layer, wherein the loop unit includes a first loop and a second loop formed inside the first loop with a predetermined space away from the first loop, each of the first loop and the second loop being formed sinuously in at least one portion.

Abstract: A method for preparing nanotubes by providing nanorods of a piezoelectric material having an asymmetric crystal structure and by further providing hydroxide ions to the nanorods to etch inner parts of the nanorods to form the nanotubes.

Abstract: Disclosed is an apparatus for generating electrical energy that includes; a first electrode, and a second electrode spaced apart from the first electrode, and an energy generation layer disposed between the first electrode and the second electrode, wherein the energy generation layer comprises a photoelectric conversion layer and a plurality of piezoelectric nanowires, and wherein when an external force is applied to at least one of the first electrode and the second electrode, the plurality of piezoelectric nanowires are transformed to generate electrical energy.

Abstract: A method for preparing nanotubes by providing nanorods of a piezoelectric material having an asymmetric crystal structure and by further providing hydroxide ions to the nanorods to etch inner parts of the nanorods to form the nanotubes.

Abstract: Disclosed is an apparatus for generating electrical energy that includes; a first electrode, and a second electrode spaced apart from the first electrode, and an energy generation layer disposed between the first electrode and the second electrode, wherein the energy generation layer comprises a photoelectric conversion layer and a plurality of piezoelectric nanowires, and wherein when an external force is applied to at least one of the first electrode and the second electrode, the plurality of piezoelectric nanowires are transformed to generate electrical energy.

Abstract: Provided is a time-domain voltage comparator including a voltage-time converter. The voltage-time converter includes a conversion unit and an output unit. The conversion unit includes a first MOS transistor which shifts a voltage level of the first detection node according to an external first voltage signal, and a second MOS transistor which shifts a voltage level of the second detection node according to an external second voltage signal. The output unit generates first and second output signals in response to voltages of the first and second detection nodes. The output unit determines a shifted time of the first output signal according to a voltage level of the first detection node and determines a shifted time of the second output signal according to a voltage level of the second detection node.

Abstract: Proton-conducting hybrid glass and a method for manufacturing the same. The proton-conducting hybrid glass has CsPWA created inside the pores of borosilicate glass. The proton-conducting hybrid glass can be used as an electrolyte for electrochemical devices, such as fuel cells and sensors. When the proton-conducting hybrid glass is used as an electrolyte membrane for a fuel cell, excellent thermal and chemical stability is realized in the range from a high temperature to an intermediate temperature of 120° C. A high proton conductivity of 10?3S/cm or higher and good catalytic activity are realized. In addition, high volumetric stability and excellent moisture retention characteristics in high and intermediate temperature ranges are achieved.

Abstract: A high molecular nanocomposite membrane for a Direct Methanol Fuel Cell (DMFC), and a Membrane-Electrode Assembly (MEA) and a methanol fuel cell including the same membrane. The high molecular nanocomposite membrane for a DMFC includes a Nafion® high molecular membrane in which hydrophobic silica nanoparticles made of a silane compound having a water repellent functional group are dispersed. Since the high molecular nanocomposite membrane for a DMFC has lower permeability of methanol than a commercially available Nafion® high molecular membrane, the MEA fabricated using the high molecular nanocomposite membrane has little crossover of reaction fuel at the negative electrode. In addition, the methanol fuel electrode fabricated using the MEA that includes the high molecular nanocomposite membrane can decrease fuel loss and voltage loss.

Abstract: An apparatus for generating electrical energy including a first electrode, a second electrode and one or more nanowires, and a method for manufacturing the apparatus for generating electrical energy. The second electrode may have a concave portion and a convex portion. The first electrode and the nanowire are formed of different materials. The nanowire is formed on the first electrode and is positioned between the first electrode and the second electrode. Because the nanowire is formed on the first electrode, the nanowire may be grown vertically and the uniformity and conductivity of the nanowires may be improved. When a stress is applied to the first electrode or the second electrode, the nanowire is deformed and an electric current is generated from the nanowire due to a piezoelectric effect of the nanowire and a Schottky contact between the nanowire and the electrode which makes contact with the nanowire.

Abstract: A material including: graphene; and an inorganic material having a crystal system, wherein a crystal plane of the inorganic material is oriented parallel to the (0001) plane of the graphene. The crystal plane of the inorganic material has an atomic arrangement of a hexagon, a tetragon, or a pentagon.

Abstract: An apparatus for generating electrical energy including a first electrode, a second electrode and one or more nanowires, and a method for manufacturing the apparatus for generating electrical energy. The second electrode may have a concave portion and a convex portion. The first electrode and the nanowire are formed of different materials. The nanowire is formed on the first electrode and is positioned between the first electrode and the second electrode. Because the nanowire is formed on the first electrode, the nanowire may be grown vertically and the uniformity and conductivity of the nanowires may be improved. When a stress is applied to the first electrode or the second electrode, the nanowire is deformed and an electric current is generated from the nanowire due to a piezoelectric effect of the nanowire and a Schottky contact between the nanowire and the electrode which makes contact with the nanowire.

Abstract: Disclosed is an apparatus for generating electrical energy that includes; a first electrode, and a second electrode spaced apart from the first electrode, and an energy generation layer disposed between the first electrode and the second electrode, wherein the energy generation layer comprises a photoelectric conversion layer and a plurality of piezoelectric nanowires, and wherein when an external force is applied to at least one of the first electrode and the second electrode, the plurality of piezoelectric nanowires are transformed to generate electrical energy.

Abstract: An apparatus for storing energy may include: a plurality of nanowire cells electrically connected to each other; and a storage for storing electrical energy generated from the nanowire cells. Each of the plurality of nanowire cells may include: first and second electrodes disposed at an interval; and a nanowire, which is disposed between the first and the second electrodes and made of a piezoelectric material. The plurality of nanowire cells may be electrically connected, so that voltage or current may be increased. Therefore, wireless recharging of the storage connected to the nanowire cells with electrical energy may be enabled.

Abstract: A method for forming a nanostructure, a nanostructure and a device using the nanostructure, wherein hydroxide ions are provided to a surface of a nanostructure including a piezoelectric material in order to etch an outer surface of the nanostructure. In an exemplary embodiment, the nanostructure may be etched by contacting the nanostructure with a basic solution. In other exemplary embodiments the etching of the nanostructure may be performed while controlling at least one of the concentration of the basic solution, the temperature of the basic solution and the etching time. The resultant nanostructure includes a piezoelectric material and has an etched outer surface. The nanostructure may be applied to various devices.

Abstract: A method for preparing nanotubes by providing nanorods of a piezoelectric material having an asymmetric crystal structure and by further providing hydroxide ions to the nanorods to etch inner parts of the nanorods to form the nanotubes.

Abstract: An apparatus for generating electrical energy including a first electrode, a second electrode and one or more nanowires, and a method for manufacturing the apparatus for generating electrical energy. The second electrode may have a concave portion and a convex portion. The first electrode and the nanowire are formed of different materials. The nanowire is formed on the first electrode and is positioned between the first electrode and the second electrode. Because the nanowire is formed on the first electrode, the nanowire may be grown vertically and the uniformity and conductivity of the nanowires may be improved. When a stress is applied to the first electrode or the second electrode, the nanowire is deformed and an electric current is generated from the nanowire due to a piezoelectric effect of the nanowire and a Schottky contact between the nanowire and the electrode which makes contact with the nanowire.

Abstract: A negative active material for a lithium secondary battery according to an embodiment of the present invention includes a core material including an inorganic particulate that is capable of forming a compound by a reversible reaction with lithium, and a surface-treatment layer disposed on the surface of the core material. The surface-treatment layer includes a metal having electronic conductivity of 103 S/cm or more. The negative active material can improve high-rate performance of a lithium secondary battery.