• Conservation Science in Museum
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• v.29
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• pp.65-80
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• 2023

This study investigated seven specimens of lead-glazed paving bricks in order to identify the materialistic characteristics of the lead glaze used for paving bricks during the late Unified Silla period in Korea. The samples were excavated from the Beopgwangsa Temple site, Pohang. As a result of observing the surface and cross-section of the glaze with a microscope, the study confirmed that the lead glaze demonstrates various traits of hydration, which were classified into four layers: Surface layer, hydration layer A, hydration layer B, and green layer. After measuring the composition of each layer with SEM-EDS analysis, the green layer was found to have been less affected by the external environment, which renders it highly reasonable to view the green layer as the original composition of the lead glaze. The green layer is a low-temperature glaze composed mainly of PbO and SiO₂ at a ratio of 8:2, with approximately 2% CuO acting as the main colorant. Comparing the green layer composition with those from Gyeongsang-do, it was confirmed that the mixture ratio of lead glaze materials was similar to other sites such as the Sacheonwangsa Temple site, the Cheonryongsa Temple site, and the Buseoksa Temple site.

• 월간낙농육우
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• v.26 no.7 s.291
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• pp.152-157
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• 2006

하절기에는 이등유에 의한 납유정지. 서균수 및 체세포수의 증가에 따른 위생등급 하락. 0.2% 정도의 유지율 저하 및 10% 이상의 산유랑 감소에 의하여 일년 중 유대 수입이 가장 적은 계절이다. 이러한 유질저하 및 산유량 감소에 따른 경제적 손실은 목장 규모 및 사양관리수준에 의해서 수십만원에서부터 수백만원에 이르기까지 매우 다양하다. 그래서 낙농가에 있어서는 가장 힘든 계절이다.

• Economic and Environmental Geology
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• v.57 no.3
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• pp.343-352
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• 2024

Composition analysis and lead isotope ratio analysis were conducted to determine the coloring machanism on lead glaze used in Gyeongbokgung Palace and the provenance of the lead used as a flux. 31 blue tiles were classified into green, blue, and yellow. The chemical analysis of lead glazes on the blue tiles revealed that Pb, Si, and Cu were the main components, and trace amounts of Fe, Ca, Mg, and Al were detected. The Cu content was high in blue lead glaze, while Cu was not detected in yellow or brown lead glaze which instead had high Fe content. Therefore, it was found that lead was used as a flux and copper oxide as a coloring agent in the production of lead glaze. In addition, the lead isotope ratios of the lead glaze used in the blue tiles of Gyeongbokgung palace were plotted in zone 3 on the distribution map of lead isotope ratios on the Korean Peninsula, which includes Chungcheong-do and Jeolla-do. It is presumed that the flux for the lead glaze was sourced from galena found in these regions. The lead isotope ratios of the green glaze from the Three Kingdoms and Unified Silla period were mostly located outside the Korean Peninsula, showing that the provenance of lead had changed. In particular, the lead isotope ratios of the green glaze from the Three Kingdoms and Unified Silla period suggest exchange with neighboring countries. Also the lead isotope ratios of the green glazes from the same temple are different, so it is believed that they were made at different times or in different workshops.

• Korean Journal of Veterinary Service
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• v.13 no.1
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• pp.27-31
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• 1990

This study was carried out to obtain basic data for the Improvement of microbiological quality of raw milk. Total bacterial, psychrotrophic, thermoduric and spore counts of raw milk samples taken from milk tankers in the nothern part of kyeongnam were investigated for one year from March, 1989. The result obtained were summarized as follow 1. The number of total bacteria in raw milk averaged $4.0{\times}10^6$ CFU / ml and was not affected by seasons 2. The psychrotrophic counts of raw milk averaged $1.5{\times}10^6$ CFU / ml and it was higher in winter than in summer 3. The thermoduric counts of raw milk averaged $5.8{\times}10^4$ CFU / ml and was the lowest in winter 4. The spore counts of raw milk ranging from 3-1, 880/ ml averaged 306/ ml and was the lowest in summer

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.2
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• pp.105-109
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• 1983

Electrical conductivity of raw milk obtained from milk cans transported from various dairy farms was discussed in relation to the contents of lactose, chloride and Koestler number to check the possibility of its application as a method for evaluation and detection of abnormality of raw milk. Correlation between the electrical conductivity and Koestler number was recognized with a coefficient of 0.76. The percentages of abnormal milk based on the Koestler number 3.5, chloride content 0.14% and the electrical conductivity $6.260({\mu}mho/cm){\times}10^3$ were 14.0%, 15.3% and 14.0%, respectively. In case of, the watered and salted milk, measurement of the specific gravity was necessary as an auxiliary process because of the decreasing electrical conductivity with increasing water content.