Evaluation of Commercial Corrosion Sensors for Real-Time Monitoring of Pipe Wall Thickness under Various Operational Conditions.

In this study, we investigated the performance and reliability of commercial corrosion sensors for monitoring the integrity of piping systems in various fluid environments as an alternative to ultrasonic transducers. To this end, we investigated pipes' wall-thinning using commercial electrical resistance (ER), linear polarization resistance (LPR), and ultrasonic transducer (UT) sensors under various operating environments. A pilot-scale closed-loop test bed was built to simulate a real pipeline flow situation, from which the sensor data were collected and analyzed. Experimental results indicate that, in the case of the LPR sensor, it is challenging to accurately measure the corrosion rate when a specific measure exceeds the threshold in a severe corrosion environment. In contrast, the ER sensor could measure metal loss under all conditions and reflect the corresponding characteristics. The metal loss (about 0.25 mm) of the real pipe after the experiment was confirmed to be equal to the metal loss (0.254 mm) measured by the sensor. Furthermore, the regression analysis revealed a high correlation between the results obtained from the ER and UT sensors. Thus, evaluating the remaining thickness of the piping system using the commercial ER sensor is deemed to be effective and reliable.

[Studies Of The Larval Trematodes From Brackish Water Fishes: 2. Observation On Metagonimus Yokogawai Katsurada, 1912]

The Parasitological investigation on the encysted metacercariae in brackish water fish, Tribolodon taczanowskii Steindachner, in the downstream of Hyungsan river which is located in Kyungpook province of Korea, were carried out, and the following results were obtained. 1)Metacercariae of Metagonimus species were found in seventy five fishes (40.5 percent) out of 185 examined. 2)Parasitic frequencies of the encysted matacercaria of Metagonimus species in Tribolodon taczanowskii were 23.2 percent (43 out of 185) in the scale, 7.0 percent (13 out of 185) in the gill, and 10.3 percent (19 out of 185) in the flesh. 3)The number of the metacercaria in the scale, gill and flesh were fewer than that of the others. 4)The worms were identified as Metagonimus yokogawai Katsurada, 1912 by morphological studies on the adults and eggs, and compared with prereported Metagonimus species.