Abstract: Disclosed herein is a method and structure for connecting first (110) and second (120) plastic pipes to each other. The structure includes: an arch-shaped heating element (130) which is made of conductive plastic material and has an arch cross-sectional shape to cover the connection hole (111), with an opening (131) formed in a central portion of the arch-shaped heating element (130); an electricity supply assembly including a plurality of unit electricity supplies disposed around the opening (131) in different directions, each of the unit electricity supplies including a pair of electric connection terminals (140) disposed parallel to each other in the arch-shaped heating element (130) on opposite sides of the opening (131); and the second plastic pipe (120) provided on the end thereof with a cover (121) covering at least an outer surface of the arch-shaped heating element (130).

Abstract: Disclosed herein is a method for connecting first (110) and second (120) plastic pipes.

Abstract: Provided is an electric power control apparatus of an electrofusion coupling pipe using a conductive polymer composite as a heating element and a method of controlling electric power using the same. The electric power control apparatus supplies electric power to the electrofusion coupling pipe using a conductive polymer composite as a heating element to detect resistance variation of the conductive polymer composite and then controls electric power supplied to the synthetic resin pipe electrofusion coupling pipe on the basis of the detected resistance variation.

Abstract: A method for the cultivation of microorganisms, especially phototrophic microorganisms in a bioreactor or photobioreactor, wherein bicarbonate ions and carbonate ions or a cation surplus concentration in the culture medium is added. A tubular bioreactor and photobioreactor is disclosed for carrying out the method.