Abstract: An intermediate jointing structure having excellent mechanical and electrical characteristics and method of preparing the same. The intermediate jointing structure includes a metal pipe and a jointing sleeve. The metal pipe is inserted between a pair of superconducting cables and is fixed to the formers by welding. A plurality of superconductor wires, shorter than the conductive metal tube, are arranged around a conductive metal tube in a longitudinal direction. The arranged superconductor wires are taped with Ag tape so as to form the jointing sleeve. The jointing sleeve is jointed and fixed on an outer surface of the metal pipe.

Abstract: A heat exchanger, which comprises a plurality of filler metal absorption means formed on both sides of each of porous smoothing tubes provided with both ends bonded to header pipes so as to prevent filler metal from flowing from the header pipes along scratches or die lines formed in the porous smoothing tubes and melting corrugated pins, thereby remarkably reducing failures generated by the melting of the pins, and having an improved external appearance compared to conventional heat exchangers having additional cutoff means.

Abstract: This invention relates to a heat driven acoustic orifice type pulse tube cryocooler for installing metal knit within a driving section cooling a driving gas of an application device using a principle of high temperature superconductivity, and then homogeneously heating the driving gas by way of premixed combustion.

Abstract: The present invention relates to silane adducts having a relatively higher adhesive strength as expressed formula X3SiR1, and manufacturing method thereof. wherein X is a hydrogenated form selected from one of epoxy compounds, amino compounds and bisphenolic, and R1 is selected from one of glycidyloxypropyl group, 2-(3,4-epoxycyclohexyl)ethyl group, 3-acryloxypropyl group, 3-methacryloxypropyl group, amino-propyl group, 3-[2-(2-aminoethylamino)ethylamino]propyl group, N-methylaminopropyl group, N-phenylaminopropyl group, N, N-dimethyl-3-aminopropyl group, mercapto-propyl group, cyano-propyl group, and isocyanato-propyl group.

Abstract: Disclosed is a fiber optic cable for a wavelength division multiplexing (WDM) optical transmission system including a plurality of connected optical fibers, wherein each of the connected optical fibers is formed of a plurality of optical fibers respectively exhibiting different dispersion values and different dispersion slopes in a predetermined operating wavelength range while having different lengths and different effective areas, the optical fibers being connected to one another in an optional order.

Abstract: Disclosed is an injection unit having a rotatable device for preventing reverse flow. To connect first flow channels formed in a spacer and second flow channels formed in a screw head when the metering is performed, and prevent reverse flow of resin by cutting off the first flow channels and the second flow channels when the resin is injected, the injection unit has a torsion spring as spring means between a shaft of the screw head and a screw, thereby rapidly preventing movement of the melted resin by restoring force of the spring when the metering of the resin is finished.

Abstract: A bundle tube type optical cable is disclosed. A bundle tube type optical cable comprises: a bundle of optical fiber tubes being arranged in the middle portion of the optical cable and each containing at least two optical fiber cores loosely arranged therein; a first water-blocking layer protecting the optical fiber cores in the optical fiber tube from external moisture by a water-blocking material filled in the inner space of the tube; an inner shell made of aluminum material enclosing the bundle of optical fiber tubes with a predetermined gap; a second water-blocking layer protecting the optical fiber tubes from external moisture by the water-blocking material filled in the inner space of the inner shell; and an outer sheath made of plastic material enclosing the outer surface of the inner shell.

Abstract: An optical cable having a metal tube receiving an optical fiber and bent to form a waved shape is disclosed. The optical cable may prevent cutoff of the optical fiber or deterioration of optical characteristics though tensile force is applied to the optical cable in its longitudinal direction since the metal is formed in a waved shape. To bend the metal tube, the metal tube is passed through roller pair(s) which are shaken in a direction perpendicular to the advancing direction of the metal tube. Thus, it is possible to obtain excess fiber length (EFL) easily and accurately as desired.

Abstract: A low noise optical amplifier used in an optical communication system includes optical amplifying elements for amplifying optical signals of a specific wavelength(&lgr;) incident from their ends(F1,F2) and endowing phase difference between ASEs, optical diverging means to interfere the amplified optical signals and the ASEs output from both ends(F1,F2), first path of length(L1) to optically connect the one end(F1) to first gate(D1) of the optical diverging means, and second path of length(L2) to optically connect the other end(F2) to second gate(D2) of the optical diverging means. The first and second paths are designed with distance(L1-L2) so that the amplified optical signal causes reinforcing interference at the third gate(D3) and destructive interference at the fourth gate(D4), and the ASE causes destructive interference at the third gate(D3) and reinforcing interference at fourth gate(D4).

Abstract: A method for manufacturing a very low roughness copper foil and an apparatus for manufacturing the copper foil. In the method of the present invention, a pickling process, an electrolytic polishing process and a washing process are successively performed after the copper foil was manufactured. In order to manufacture the very low roughness copper foil, the electrolytic polishing process is accomplished with the copper foil to face a metal cathode plate and supplying a current in order to perform the electrolytic polishing.

Abstract: The present invention relates to a method for manufacturing a low roughness electrodeposited copper foil, and an electrodeposited copper foil manufactured thereby, and uses an electrolyte which basically consists of a sulfuric acid, a copper ion and a chloride ion is adapted with an additive which consists of a HEC (Hydroxyethyl Cellulose) of 0.05˜50 ppm, a SPS (bis(sodiumsulfopropyl)disulfide) of 0.05˜20 ppm, and a gelatin of 0.1˜100 ppm. The present invention is adapted to manufacture a low roughness electrodeposited copper foil using a conventional copper foil manufacture facility and the electrodeposited copper foil according to the present invention is adapted as a material for a copper clad laminate for a printed circuit substrate and an electrode material for a lithium ion battery.

Abstract: The present invention relates to a tube-enclosed optical cable containing ribbon units, and more specifically to a tube-enclosed optical cable containing ribbon units which can improve the economical efficiency of the process by simplifying the manufacturing process of optical cable and at the same time can improve the water blocking capability and compression characteristics of optical cable, providing optical cable characterized by coating particularly the central member of the cable with an absorptive substance and optical cable characterized by inserting interstices coated with an absorptive substance into the empty spaces between one more tubes encircling the central member and the sheath enclosing the tubes.

Abstract: A furnace for drawing an optical fiber includes a body having an upper and lower openings for supplying a preform and discharging a drawn optical fiber, a heating unit installed in the body for receiving and melting the preform, an atmosphere blocking tube installed to the lower opening for discharging the drawn optical fiber and blocking the optical fiber from the atmosphere, an upper introduction port formed at an upper portion of the body for introducing an inert gas toward the preform and partially discharged outside through a gap between the preform and the upper opening, a central and lower introduction ports formed at central and lower portions for introducing an inert gas into the body, a first flow guiding means for guiding the inert gas introduced through the central introduction port upward and then flowed down along a surface of the preform, and a second flow guiding means for guiding the inert gas introduced through the lower introduction port upward and then discharged outside through the atmosp

Abstract: In an optical fiber drawing apparatus capable of drawing one piece of an optical fiber, the present invention provides an optical fiber drawing apparatus which is adapted to decrease a break of an optical fiber to be adjusted a curvature radius thereof by at least one or more moving rollers continuously installed after a fixing roller and to decrease a polarization mode dispersion (PMD) by a birefringence which is not desired in an optical fiber.

Abstract: An apparatus for reversing upper and lower surfaces of a lead frame which passes through a silver-plating process in a lead frame manufacturing process includes at least one guide rail having a curved portion for guiding the lead frame to be fallen down and reversed along an arc of the curved portion, and a conveying roller provided under the guide rail to horizontally convey the fallen lead frame. Thus, since the lead frame is reversed through a specific structure without use of any robot, the malfunction problem of the prior art is solved and costs are reduced.

Abstract: Disclosed is an optical fiber having a desired dispersion value to sufficiently suppress a non-linearity phenomenon, that is, a four-wave mixing phenomenon, occurring at a channel spacing of 50 GHz while minimizing the expense consumed for a compensation for dispersion. The optical fiber satisfies optical characteristics defined by a dispersion value of 7 to 10 ps/nm-km at a wavelength of 1,550 nm, a zero dispersion wavelength of 1,450 nm or less, and a cut-off wavelength of 1,250 nm or less. The optical fiber includes a core having a desired diameter (d1) and a desired refractive index (n1), the cladding surrounding the core and having a refractive index (ncl) less than the (n1), of the core (ncl<n1) or (n2) less than the outer cladding (n2<ncl). The (n2) of the inner cladding may also be less than the (n1) of the core and more than the (ncl) of the outer cladding.

Abstract: A low noise optical amplifier used in an optical communication system includes optical amplifying elements for amplifying optical signals of a specific wavelength(&lgr;) incident from their ends(F1,F2) and endowing phase difference between ASEs, optical diverging means to interfere the amplified optical signals and the ASEs output from both ends(F1,F2), first path of length(L1) to optically connect the one end(F1) to first gate(D1) of the optical diverging means, and second path of length(L2) to optically connect the other end(F2) to second gate(D2) of the optical diverging means. The first and second paths are designed with distance(L1-L2) so that the amplified optical signal causes reinforcing interference at the third gate(D3) and destructive interference at the fourth gate(D4), and the ASE causes destructive interference at the third gate(D3) and reinforcing interference at fourth gate(D4).

Abstract: The present invention is related to a dispersion-shifted optical fiber for use in a wavelength division multiplexing system, which comprises a core, an inner clad, and a silica clad, wherein the optical fiber has a relatively low dispersion at a wavelength of 1550 nm, an effective area of 60 &mgr;m2 and small bending loss. The core consists of a first and a second core, wherein the core has a refractive index distribution. The inner clad consists of a first inner clad having a refractive index smaller than that of the second core and a second inner clad having a refractive index smaller than that of the second inner clad. A silica clad surrounds the inner clad and has a refractive index smaller than that of the second inner clad.

Abstract: Disclosed is a method of adjusting a tractor to a horizontal position and an apparatus for performing the same. The method comprises the steps of determining whether or not the tractor is in an automatic mode, determining whether the tractor is in a flat land or in a slope land if the tractor is in the automatic mode, adjusting a height of the body with respect to a ground if the tractor is in the flat land, determining a driving direction of the tractor if the tractor is in the slope land, adjusting the body to the horizontal position by controlling the body in left and right directions thereof if the tractor is driving in a contour direction, adjusting the body to the horizontal position by controlling the body in front and rear directions thereof if the tractor is driving in a latitudinal direction, and adjusting the body to the horizontal position by controlling the body in front, rear, left and right directions thereof if the tractor is driving in an oblique direction.