Abstract: The present invention relates to vinyl-phenyl monomers and polymers prepared therefrom.

Abstract: The present invention relates to fluorine-containing triarylphosphine oxide derivatives and preparing method thereof. Particularly, the present invention relates to both fluorine- and phosphine oxide-containing triarylphosphine oxide derivatives which can be utilized in preparing polyimides having excellent adhesion, fire retardancy and low dielectric constant as well as superior thermal stability and mechanical properties, and preparing method thereof.

Abstract: The present invention relates to an apparatus for measuring the thickness of materials using the focal length of a lensed fiber and a method thereof. More particularly, the invention relates to a method of measuring the thickness of materials using the strength of the beam reflected from the focal length when the beam emitted from a lensed fiber is focused on a material.

Abstract: Disclosed are polyarylene ether sulfides and polyarylene ether sulfones for optical device and a method for preparing the same. Polyarylene ether sulfides containing fluorine and polyarylene ether sulfones containing fluorine are synthesized through polycondensation of pentafluorophenyl sulfide and pentafluorophenyl sulfone monomer with dihydroxy monomer. In addition, by attaching ethynyl phenol and phenylethynylphenol to terminals of the high molecular weight polymer, solvent resistance of the polymer is increased. Thus, the high molecular weight polymers prepared by very simplified process have low light loss, excellent resistance for heat, solvent and water, and so can be used to manufacture inactive optical waveguide devices.

Abstract: Described in the present invention are a method for determining the pore size distribution of a membrane filter based on the molecular mass distribution curve of the rejected solute fraction of a feed solution when the feed is passed through the membrane, and an apparatus suitable for practicing said method.

Abstract: A method for preparing a platinum alloy electrode catalyst for DMFC using anhydrous metal chlorides. The method includes reducing platinum chloride and non-aqueous second metal chloride with boron lithium hydride (LiBH4) in a water-incompatible organic solvent in a nitrogen atmosphere to form nano-sized particles of colloidal platinum alloy, and drying the platinum alloy particles without any heat treatment. The method of preparing a platinum alloy catalyst according to the present invention makes it possible to prepare platinum alloy particles having a narrow range of size distribution and an average particle size of less than 2 nm with ease, relative to the conventional methods. The platinum alloy particles thus obtained can be used as an electrode catalyst for DMFC to enhance methanol oxidation performance.

Abstract: The present invention relates to vinyl-phenyl monomers and polymers prepared therefrom. More particularly, the present invention is to provide the vinyl-phenyl monomers expressed by formula (1) which are capable of various polymerization such as radical polymerization, cation polymerization, anion polymerization and metallocene catalyzed polymerization due to resonance effect of phenyl group and changing characteristics variously and thus, suitable in the synthesis of general-purpose polymers which can be used in photo-functional materials by forming a complex with a metal component having an optical characteristic.

Abstract: The present invention relates to an orthogonal frequency division multiplexing(OFDM) system.

Abstract: The present invention relates to a light-emitting device utilizing amorphous silicon quantum dot nanostructures, wherein the light-emitting device can be fabricated using the existing silicon semiconductor fabrication technology, is excellent in light-emitting efficiency, and can emit light in the visible region including short wavelength region such as green and blue.

Abstract: The present invention relates to a measurement method of resonant nonlinearity in a nonlinear optical fiber using a long period fiber grating pair. In particular, it relates to a characteristic evaluation method that can simply, but accurately, measure the nonlinear optical characteristics of an optical fiber.

Abstract: The present invention relates to fluorine-containing 3,6-di(3′,5′-bis(trifluoromethyl)benzene)pyromellitic dianhydride as a monomer which can be used in preparing polyimides with high glass transition temperature, low dielectric constant and excellent processability, and preparing method thereof.

Abstract: The present invention relates to fluorine-containing 3,6-di(3′,5′-bis(trifluoromethyl)benzene)pyromellitic dianhydride as a monomer which can be used in preparing polyimides with high glass transition temperature, low dielectric constant and excellent processability, and preparing method thereof.

Abstract: Disclosed are an epitaxial structure for low ohmic contact resistance in p-type GaN-based semiconductors and a method for growing such a structure. A very high density of p-type doped GaAs or p-type graded AlxGa1−xAs (0<x≦1) is formed between an ohmic metal and a p-type GaN and subjected to crystal growth. The doped p-type GaAs or graded p-type AlxGa1−xAs reduces the potential barrier formed in the p-type GaN, thus significantly reducing the ohmic resistance. This structure can be applied for the improvement in the power efficiency and function of GaN-based optical devices and ultra-speed electronic devices.

Abstract: The invention relates to triarylphosphine oxide derivatives containing fluorine substituents that are useful as a monomer in preparation of polymers with improved properties such as chemical resistance and electrical insulating property as well as adhesiveness and flame retardancy. The triarylphosphine oxide derivatives containing fluorine substituents are represented by the chemical formula 1: wherein R1 and R2 are independently a fluorine-substituted alkyl group; and X is hydrogen, a nitro group, or an amine group.

Abstract: A method of fabricating on ohmic metal electrode. The p-type ohmic metal electrode according to the present invention employs Ru and RuOx as the cover layer in lieu of conventional Au, in order to effectively prevent penetration by contaminants in the air, such as oxygen, carbon, and H2O, and to form a stable metal-Ga intermetallic phase at the junction between the contact layer and the nitride compound semiconductor. The n-type ohmic metal electrode according to the present invention employs Ru as the diffusion barrier in lieu of conventional Ni or Pt, in order to effectively form a metal-nitride phase such as titanium nitride that contributes to superior ohmic characteristics during the heating process, without destruction of the junction. According to the present invention, it is possible to fabricate devices having superior electrical, optical, and thermal characteristics compared with conventional devices.

Abstract: Disclosed herein is a method for synthesizing a composite of a conductive macromolecule and a protein component. The method utilizes, as the protein component, a protein composite consisting of protein bonded to a macromolecular anion. The protein composite can serve as a dopant to improve an electrical conductivity of the conductive macromolecule and also to impart multifunctional properties to the conductive macromolecule.

Abstract: Disclosed is a method for manufacturing a high conductivity p-type GaN-based thin film superior in electrical and optical properties by use of nitridation and RTA (rapid thermal annealing) in combination. A GaN-based epitaxial layer is grown to a desired thickness while being doped with Mg dopant with a carrier gas of hydrogen by use of a MOCVD process. The film thus obtained is subjected to nitridation using nitrogen plasma and RTA in combination. The p-type GaN-based thin film exhibits high hole concentration as well as low resistivity, so that it can be used where high electrical, optical, thermal and structural properties are needed. The method finds application in the fabrication of blue/white LEDs, laser diodes and other electronic devices.

Abstract: A contactless eddy current brake for cars is disclosed. In the brake, two cores are arranged around the edge of a brake disc while being spaced apart from each other at an angle of 90°. Each of the cores is wound with a coil, thus forming an electric magnet. A speed sensor is positioned around the axle, thus sensing revolutions of the wheel. A control unit calculates a DC or AC control current in response to a speed signal output from the sensor, thus outputting an appropriate control current value to the coils. A current amplifier supplies the control current value from the control unit or a current value from a brake pedal to the coils of the cores. The control unit allows a DC current to be supplied to the coils when the car runs at a high speed or allows an AC current with different phases to be supplied to the coils when the car runs at a low speed or is stopped on a slope.

Abstract: Disclosed is a multiple-stage cyclone including a double-stage cyclone and a triple-stage cyclone.

Abstract: A metal thin film with an ohmic contact for light emit diodes and a method of producing such a film are disclosed. The metal thin film has a p-type gallium nitride (GaN) semiconductor layer. Nickel (Ni), platinum (Pt) and gold (Au) layers are deposited on the GaN semiconductor layer in a way such that the gold layer forms a top layer, with either one of the platinum and nickel layers being selectively used as an inter-diffusion barrier between metal layers. The inter-diffusion barrier may be formed by depositing platinum between the nickel and gold layers, thus forming an Ni/Pt/Au metal thin film, or formed by depositing nickel between the platinum and gold layers, thus forming an Pt/Ni/Au metal thin film. In the method, a GaN semiconductor is washed so as to be free from carbide and oxide layers. The Ni, Pt and Au layers are formed on the GaN semiconductor layer through a vacuum deposition process at 5×10−5-2×10−1 torr.