Abstract: The present invention relates to a method for preparing polylactic acid. According to the method for preparing polylactic acid, high quality polylactic acid can be provided by effectively removing residual monomers while minimizing property changes of the polylactic acid.

Abstract: A remote control system to remotely control a take-out robot of an injection molding machine on a production site through network includes an injection molding machine to produce and convey injection molded products through the take-out robot. A remote controller transmits and receives the operation data of the take-out robot and the information data on the injection molding to and from the injection molding machine through the wireless internet. The remote controller remotely controls the injection molding machine based on the utilized operation data and information data. A control pendent connected to the injection molding machine remotely controls the take-out robot, performs three-dimensional graphic simulation for the previous operations before operating the take-out robot and for loading motions of the injection molded products, and stores and outputs the three-dimensional graphic images of the injection molded products, based on a previously stored remote control access program.

Abstract: The present invention relates to a method for preparing polylactic acid. According to the method for preparing polylactic acid, high quality polylactic acid can be provided by effectively removing residual monomers while minimizing property changes of the polylactic acid.

Abstract: Disclosed are antibacterial fibers, a master batch for manufacturing antibacterial fibers, and a method for manufacturing antibacterial fibers. The antibacterial fibers can exhibit excellent antibacterial activity by using, as an antibacterial agent, zinc oxide nanoparticles having a high specific surface area, a low melting temperature, and a stable crystal structure.

Abstract: The present invention relates to a single CSTR bioreactor equipped with a cell recycle unit, and a multi-stage CSTR bioreactor system in which 2-7 such single CSTR bioreactors are connected in series with each other. According to the present invention, multi-stage fermentation is carried out in the bioreactor equipped with the cell recycle unit, and thus the production of products (alcohols, organic acids, antibiotics, recombinant proteins, etc.) by anaerobic or aerobic microbial fermentation can be increased, and in addition, a final product can be obtained at high concentration, thus improving the productivity and economic efficiency of a microbial process.