• KOREAN POULTRY JOURNAL
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• v.51 no.9
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• pp.107-107
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• 2019

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.33-34
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• 2022

The purpose of this study was to provide basic data for applying oyster shells and egg shells as fireproof cladding materials by substituting fine aggregates for oyster shell powder and egg shell powder, and comparing strength and fire resistance performance. The reason for the high strength was thought to be that the oyster shell had higher strength than the egg shell itself, and both ESP and OSP were measured at a backside temperature of less than 500℃, so it was judged that it could be used as a fireproof coating for steel structures.

• Journal of the Korea Convergence Society
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• v.12 no.6
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• pp.33-38
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• 2021

In order to manufacture a lightweight medical radiation shielding sheet, a new shielding material was studied. We tried to verify the possibility of a shielding material by mixing egg shell powder, which is thrown away as food waste at home, with a polymer material. Existing lightweight materials satisfy eco-friendly conditions, but there are difficulties in the economics of shielding materials due to the cost of the material refining process. This study aims to solve this problem by using egg shells, which are household waste. A 3 mm-thick shielding sheet was fabricated using HDPE, a polymer material, and particle distribution within the cross-section of the shielding sheet was also verified. The shape of the particles was rough and there were voids between the particles, and the average weight per unit area was 1.5 g/cm². The shielding performance was around 20% in the low energy area and 10% in the high energy area, showing the possibility of a low-dose medical radiation shielding body.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.46-47
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• 2020

Oyster shells and egg shells consist of CaCO3, which is known to have excellent fire performance as the main component, and research is currently being conducted as a fireproof board material. Therefore, in this study, the physical and chemical properties of oyster shell powder and egg shell powder are studied to find out the applicability of fireproof board

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.75-76
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• 2020

Use fire resistant construction methods, of which fire resistant boards are used to protect buildings and structures from fire. However, in the case of fire resistant boards, the unit price of the main raw material is high and the cost efficiency is low. There have been studies to apply oyster shells to fire resistant boards to solve these problems. On the other hand, egg shells are also considered to be applicable to fire-resistant boards with components like oyster shells, but there is no case of using egg shells as building materials. Therefore, in this study, we confirmed the physical properties of egg shell powers used as mortar filler and compared them with the fire resistant board flexural strength standard. As a result, it was judged that the powder of egg shells could be used as a building material, because the standards for the flexural strength of fire resistant boards were satisfied except for a part.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.94-95
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• 2020

Oyster shells are characterized by coarse and coarse grains, but similar in strength to sand, and egg shells are fine grains but weak in strength. In terms of supply and demand of raw materials, oyster shells can be supplied only in limited periods and regions in winter and south coast of the year, but egg shells have the advantage of being able to supply and supply nationwide 365 days. This study aims to study the change in strength characteristics by mixing oyster shell powder and egg shell powder with the same particle size and mixing up to 150%. The conclusions of the flexural and compressive strength tests of mortar mixed with oyster shell powder and egg shell powder are as follows. The 7-day flexural and compressive strength with ESP added and the 3-day flexural and compressive strength with OSP added were similar, which is thought to be because the strength of OSP is higher than that of ESP.

• Korean Journal of Agricultural Science
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• v.35 no.2
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• pp.193-198
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• 2008

This experiment is a quantitative experiment where insoluble Vitamins E and K are extracted from the yolk of the spawning which was fed by by-products of tangerine, carrot, or Japanese apricot. Finally the purpose is to raise contents of the insoluble Vitamins E and K inside the yolk of the spawning. The saponification method through ${\alpha}$, ${\alpha}$ - dipyridyl was used to determine the content of Vitamin E. Diethyl dithiocarbamate assay was used to examine the content of Vitamin K. The contents of Vitamin E in egg yolks of chicken fed by by-products of tangerine, carrot, or Japanese apricot increased 2 - 3 times compared to control egg, while the contents of Vitamin K almost no changed.

• Korean Journal of Environment and Ecology
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• v.22 no.6
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• pp.648-657
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• 2008

This research was conducted to investigate the breeding density and seasonal food items of the magpies in Jeju Island and the near-manned islets. The examination of nest distribution to determine breeding density was performed during breeding season from February 2006 to April 2008, and that of food items from May 2006 to February 2008. A total of 2,113 nests were found across Jeju Island, the average density was $1.33\;nest/km^2$, and the magpies were distributed up to 600 meters above the sea level. The nest density was the highest in the central areas of Jeju Island, with 688 nests at $3.61\;nest/km^2$, while that in the eastern areas was the lowest, with 214 nests at $0.66\;nest/km^2$. In terms of the number of nests depending on the height above the sea level, 1,172 nests, which was equivalent to the density of $1.85\;nest/km^2$, was observed below 100m and highest among the intervals of height, but 16 nests found at 500-600m were the lowest, corresponding to $0.20\;nest/km^2$. The number of nests found in the manned islets near Jeju Island was eight in Biyang-do with the density of $15.38\;nest/km^2$, nine in U-do with $1.49\;nest/km^2$, and one in Gapa-do with $1.15\;nest/km^2$, whereas none of nests were observed in Mara-do. The contents of stomach consisted of 17 types of prey sources including countless bones, eggshells, plants, and seed, most of which were the individuals of the order Coleoptera. In spring and summer, the foraging frequency for invertebrate animals such as insects was high, but less than 30% in winter. In contrast, the magpies preyed upon plants and seeds at the frequency of 10% and 30%, respectively, in spring, while the foraging frequencies for both of them were 100% in winter and higher than any of other seasons. Eggshells and bones of birds were also detected infrequently. If the density of the magpies, which may play role as the upper predator within the ecosystem, increases, it would be expected to affect directly the reduction of the number of the species and population of endemic animals such as small birds and reptiles, etc. Therefore, it is considered that long-term monitoring for the density of the magpies and precaution is prerequisite to minimize adverse effects on ecosystem.