Abstract: A biodegradable polyester is formed by carrying out esterification and polycondensation with a carboxylic acid monomer group comprising at least one aliphatic dicarboxylic acid containing 2 to 14 carbon atoms and at least one aromatic or alicyclic carboxylic acid, and at least one glycol in the presence of a composite catalyst comprising a titanium compound, a zinc compound, an antimony compound and a phosphorous compound. The composite catalyst significantly improves the reaction rate of polyester polymerization as well as increases the production amounts of the polyester, as compared with conventional catalysts. The polyester is high in molecular weight, excellent in thermal and mechanical properties by virtue of the introduction of the aromatic or alicyclic carboxylic acid or its derivative, in addition to showing good biodegradability. This polyester can replace preexisting, expensive aliphatic polyesters.

Abstract: The invention relates to the method and device for generating the uniformalized laser beam, wherein passing through a triplet alpanatic convex lens, the focal point size is minimized, after the condensed laser beam being incident upon the optical fiber and passing through the bent optical fiber in circle form in first and second place (and third plane) each vertically arranged, is uniformed by accelerated screw increments and diffused reflections, the laser energy condensed in the center portion is diffused uniformly all over the section area, and also one base plate formed on which one bending guide for winding and suspending the optical fiber passing through each circular and local bending, and one local bending adjusting portion for shaping the said fiber wound around the local bending portion of said bending guide into locally bent form are fixed each other of one bending portion, by arranging and fixing said two bending portions vertically each other, the optical fiber is put in order along the bending g

Abstract: A method for the deposition of a diamond film, which includes the steps of immersing metallic or nonmetallic substrate in and electroless nickel plating bath containing a reducing agent to form a nickel layer; and depositing the diamond film on the electroless nickel plated substrate. As a result, employing electroless plating to form an inter layer is improved. In addition, the diamond film can be formed regardless of the type of materials used.