Abstract: The present invention relates to a composition for preventing at least one plant disease resulted from infection of plant pathogens and a method for preparing the same. Particularly, the composition contains extract of at least one plant selected from the group consisting of Coptis chinensis Franch., Phellodendron genus plant, Sanguinaria canadensis and Chelidonium majus var. asiaticum which are natural plants having anti-plant pathogen activity or berberine which is purified therefrom. The composition of the present invention can be effectively used for preventing disease pathogens such as plant powdery mildew, anthracnose of pepper, damping-off of cucumber and gray mold rot of strawberry resulted from infection of plant pathogens such as Colletrotrichum gloeosporiodes, Pythium ultimum or Botrytis cinerea.

Abstract: Disclosed herein are a high-sensitivity method and apparatus for monitoring the concentration or inflow of impurities in circulating water of a circulating water system, which can remarkably improve the measurement sensitivity by converting carbonate ions of low conductivity into chlorine or sulfate ions of increased conductivity, and which can measure the inflow of air or organic substances and the amount of inflow in a simple and efficient manner in real-time. The method of the present invention comprises the steps of: increasing a content of strong acids in sample water and thus increasing equivalent conductivity of the impurities, by utilizing cation exchange resin together with anion exchange resin, in which cations of the sample water are adsorbed on the cation exchange resin to form strong acids while weakly acidic anions of low dissociation degree in the sample water are adsorbed on the anion exchange resin to form strong acids; and measuring the increased conductivity of the impurities.

Abstract: Disclosed herein are a high-sensitivity method and apparatus for monitoring the concentration or inflow of impurities in circulating water of a circulating water system, which can remarkably improve the measurement sensitivity by converting carbonate ions of low conductivity into chlorine or sulfate ions of increased conductivity, and which can measure the inflow of air or organic substances and the amount of inflow in a simple and efficient manner in real-time. The method of the present invention comprises the steps of: increasing a content of strong acids in sample water and thus increasing equivalent conductivity of the impurities, by utilizing cation exchange resin together with anion exchange resin, in which cations of the sample water are adsorbed on the cation exchange resin to form strong acids while weakly acidic anions of low dissociation degree in the sample water are adsorbed on the anion exchange resin to form strong acids; and measuring the increased conductivity of the impurities.