Abstract: A welding gun is incorporated into a unidirectional welding system, where the unidirectional welding system includes: the welding gun performing welding when a set pressing force is applied; a power portion configured to generate power to be applied to the welding gun; a power connecting portion having one end portion connected to the power portion through a power wire and an opposite end portion engaged with the welding gun; and a power switch provided at the power connecting portion to selectively apply the power generated from the power portion to the welding gun.

Abstract: A welding gun is incorporated into a unidirectional welding system, where the unidirectional welding system includes: the welding gun performing welding when a set pressing force is applied; a power portion configured to generate power to be applied to the welding gun; a power connecting portion having one end portion connected to the power portion through a power wire and an opposite end portion engaged with the welding gun; and a power switch provided at the power connecting portion to selectively apply the power generated from the power portion to the welding gun.

Abstract: A vacuum cleaner includes a vacuum suction pipe through which impurities are collected together with air. A suction side plate has a central hole which corresponds with the vacuum suction pipe so that the vacuum suction pipe is fitted in the central hole. A holding plate is spaced apart from the suction side plate. A spring unit connects the suction side plate with the holding plate to elastically adjust a distance between the suction side plate and the holding plate.

Abstract: A vacuum cleaner includes a vacuum suction pipe through which impurities are collected together with air. A suction side plate has a central hole which corresponds with the vacuum suction pipe so that the vacuum suction pipe is fitted in the central hole. A holding plate is spaced apart from the suction side plate. A spring unit connects the suction side plate with the holding plate to elastically adjust a distance between the suction side plate and the holding plate.

Abstract: A vacuum cleaner includes a vacuum suction pipe through which impurities are collected together with air. A suction side plate has a central hole which corresponds with the vacuum suction pipe so that the vacuum suction pipe is fitted in the central hole. A holding plate is spaced apart from the suction side plate. A spring unit connects the suction side plate with the holding plate to elastically adjust a distance between the suction side plate and the holding plate.

Abstract: Disclosed are a terminally modified polyoxyalkylene glycol which may dramatically improve color uniformity and machinability, when applied to a polycarbonate resin transmittance, a polycarbonate resin composition comprising the same, and a light guide plate manufactured using the same.

Abstract: Disclosed are a terminally modified polyoxyalkylene glycol which may dramatically improve color uniformity and machinability, when applied to a polycarbonate resin transmittance, a polycarbonate resin composition comprising the same, and a light guide plate manufactured using the same.

Abstract: A cooling system for a spot welding device which cools heating parts of a spot welding device including two electrodes, a gun body, and a transformer, may include an air compressor, an air separator connected with the air compressor and separating compressed air supplied from the air compressor into hot air and cooling air, and a connection line supplying the cooling air separated by the air separator to a heating part of the spot welding device.

Abstract: The present invention relates to a thermal-cracking method of hydrocarbon using a hydrocarbon thermal-cracking apparatus including a tube type furnace having a radiation part for thermally cracking hydrocarbon feedstocks supplied together with steam and a convection part. A hydrocarbon thermal-cracking catalyst is packed in some or entire area of the tube placed in the radiation part of the tube type furnace, wherein the hydrocarbon thermal-cracking catalyst includes an oxide catalyst represented by CrZrjAkOx (wherein, 0.5?j?120 and 0?k?50, A is a transition metal, and x is a number corresponding to the atomic values of Cr, Zr, and A and the numbers of j and k). Therefore, it is possible to improve yield and selectivity of olefin, reduce fuel consumption due to an excellent heat transfer efficiency and extend decoking interval by reduced production of coke deposited to an inside wall of a tube, in steam cracking of hydrocarbon for producing olefin.

Abstract: The present invention relates to a thermal-cracking method of hydrocarbon using a hydrocarbon thermal-cracking apparatus including a tube type furnace having a radiation part for thermally cracking hydrocarbon feedstocks supplied together with steam and a convection part. A hydrocarbon thermal-cracking catalyst is packed in some or entire area of the tube placed in the radiation part of the tube type furnace, wherein the hydrocarbon thermal-cracking catalyst includes an oxide catalyst represented by CrZrjAkOx (wherein, 0.5?j?120 and 0?k?50, A is a transition metal, and x is a number corresponding to the atomic values of Cr, Zr, and A and the numbers of j and k). Therefore, it is possible to improve yield and selectivity of olefin, reduce fuel consumption due to an excellent heat transfer efficiency and extend decoking interval by reduced production of coke deposited to an inside wall of a tube, in steam cracking of hydrocarbon for producing olefin.