• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.931-932
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• 2009

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.4
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• pp.526-532
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• 2000

Recent studies have been directed toward obtaining a better understanding of the application of electrostatic precipitators to collect fly ash particles produced in a coal-fired power plant. Electrical resistivity can be described as the resistance of the collected dust layer to the flow of electrical current and is an important property for the collection efficiency in the electrostatic precipitator. In this paper, fly ash resistivity as a function of temperature up to $450^{\circ}C$ has been experimentally investigated using the resistivity meter consisted of the movable electrode, dust cup, and furnace. Resistivity was found to increase with increased temperature up to $200^{\circ}C$ due to the reduction of water concentration and then gradually decrease with increased temperature due to the activation of electrons. As the resistivity of fly ash in the flue gas temperature of $150^{\circ}C$ was measured >$10^{10}$ ohm cm, the efficiency of fly ash removal in the electrostatic precipitator might be expected to be low due to back-corona phenomenon. Flue gas conditioning in the electrostatic precipitator to reduce the resistivity of fly ash as required.

• Korean Journal of Heritage: History & Science
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• v.57 no.1
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• pp.162-178
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• 2024

Swans are representative migratory birds that spend winter in East Asia, and have long been considered rare birds. In particular, they were regarded as king of Japan. The process of designating a natural monument in Hapcheon Swan Sanctuary is an interesting story. In this study, the designation and release process of Hapcheon Swan Sancturay ((Bakgok-ji, Yongju-myeon 龍州面 朴谷池), (Jeongyang-ji, Daeyang-myeon 大陽面 正陽池), Gaho, Cheongdeok-myeon 淸德面 嘉湖)) Natural Monument, was examined. These places were designated as a natural monument on August 27, 1934, during the Japanese colonial period, and was lifted on August 14, 1973, after the Cultural Protection Act was enacted after liberation. From the beginning of the new year in 1929, the Japanese Government-General of Korea (朝鮮總督府) decided to capture swans alive to give to the king of Japan. An official of the Japanese Government-General of Korea (統監) decided to offer swans to the king during his New Year's greeting visit. The department in charge of capturing swans was the Gyeongsangnam-do Provincial Police Department, and the execution was the police station of each county (郡). The reason is believed to be that it is easy to forcibly mobilize, control, or urge people, and the capture activity had to be completed as soon as possible. A total of three swans were captured in Hapcheon-gun from January 12 to 14, 1929. At that time, various newspapers published related information. Based on these facts and experiences, it is estimated that the Hapcheon area was selected when designating a natural monument in 1934. Hapcheon Swan Sancturay, Natural Monument lost its function due to excessive human interference of various developments, illegal capture, and use of poison to catch swans. Their number has also significantly decreased. It was thus removed from the natural monument in 1973. One of the three swan sanctuaries (Gaho 嘉湖) has been completely reclaimed, one (Bakgok-ji 朴谷池) has almost no migratory birds due to the conversion of wetlands, and one (Jeongyang-ji 正陽池) has swans flying back. In the case of Jeongyangji (正陽池), It is an encouraging sign that many swans fly as the surrounding environment and growing conditions change. This phenomenon is interpreted to mean that nature and climate are recovering and healing.