Abstract: A system for monitoring the operation of a plant, which includes the facility of simulating the corrosion potential of a material and which can assess the effect of a countermeasure for mitigating the corrosion environment of the material, with the corrosion potential obtained by the simulation. The corrosion potential of the structural material of the plant is computed through a numerical analysis by applying an electrochemical mixed-potential theorem on the basis of the analytical result of a charge transfer reaction. Programs for such potential computations are prestored in a computer system from which data are accepted into a host computer. The computed corrosion potential is related with water quality data (for example, the concentration of hydrogen injected into the plant), and the relationship is output to a display unit.

Abstract: A 3-propenylcephem derivative of the following formula: ##STR1## wherein R.sub.1 represents a fluoro-substituted lower alkyl group or a cyano-substituted lower alkyl group, and A represents a cyclic or an acylic ammonio group, or a pharmaceutically acceptable salt thereof, exhibiting excellent anti-bacterial activities against both Gram-positive bacteria and Gram-negative bacteria; Process for the preparation thereof; Anti-bacterial composition; intermediate for the 3-propenylcephem derivative; and Process for the preparation of the intermediate.