• Proceedings of the Korea Technology Innovation Society Conference
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• 2015.11a
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• pp.479-487
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• 2015

In Korea, there are 1,474 thousand pumping wells nationwide which account for about 12% of total water use in 2012. As much as 39 hundred million tons of groundwater were used while 333 hundred million tons of total water were supplied in 2012. Because the water management authority projects that water demand will exceed supply by 2021, the authority is planning to extensively expand groundwater use in accordance with economic feasibility. Using the basic frameworks of cost-benefit analyses of the World Bank and the US Environmental Protection Agency (US EPA), the objective of this study is to examine the costs and benefits of the expansion of Korea's groundwater extraction through pumping wells. We conclude that the BC ratio of the groundwater pumping wells is 2.98. This signifies that the benefits are 2.98 times higher than the costs. The benefits include use and non-use values of pumping wells while the costs include the installation and maintenance of new wells, in addition to the restoration and pollution costs of abandoned wells, as well as fees for water quality tests, etc.

• Parasites, Hosts and Diseases
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• v.29 no.2
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• pp.189-192
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• 1991

Status of metacercarial infections of Paragcnimus westermani was observed in freshwater crabs, which were purchased at 3 markets in its peak season of 1990. All of 85 crabs were Eriocheir japenicus. No other species of Eriocheir were found. When crushed muscle and viscera was examined individually, the infection rate was 11.8% ; and mean number of metacercariae was 2.1 per infected crab. Unless adequately cooked, freshwater crabs are still potential sources of human paragonimiasis.

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.244-249
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• 2012

This study was carried out to investigate effect of serum lipid and liver tissue in lectin from Viscum album on rats. The lectin was purified by sepharose 4B affinity chromatography and gel filtration using sephadex G-150 with plant material from Viscum album. After 72 h of $CCl_4$ injection, there was a significant increase in serum total cholesterol and triglycerige levels relative to the control group. However, treatment of both Viscum album and purified lectin were significantly decreased lipid parameters against the $CCl_4$-induced. Histological observation of the liver section of rats challenged with $CCl_4$ produced a marked increase of cytoplasmic vacuoles in number, while rats administered olive oil alone did not alter the normal hepatic architecture. Histological observation of the liver section in rats treated 72 h with either Viscum album purified lectin or $CCl_4$-induced liver lipogenesis showed decreased numbers of cytoplasmic vaculoes and necrotic cells. These results suggest that Viscum album lectin has a significantly decreased lipid in serum or histological observation of the liver section decreased in lipogenesis in rats.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1729-1733
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• 2010

본 연구에서는 7개 지점(여주, 적성, 왜관, 진동, 공주, 구례2, 나주)에 대해 유사량 특성 분석을 수행하였다. 부유사량은 강우가 집중되는 홍수기와 이의 전 후시기인 저 평수기(2회)로 나누어 왕복수심적분법(D-74)으로 측정하였고, 하상토는 BM-54, Grab Sampler(60 L), 선격자 등을 이용하여 홍수기 전 후로 2회 채취하였다. 채취된 시료는 그 목적에 따라 여과법(부유사농도), BW관법(부유사입도분포), 체분석법(하상토입도분포)으로 분석하였고, 그 결과로 작성된 평균 부유사농도 및 Oden Curve와 입도분포곡선과 수리량(수위, 유속, 측정수심, 수면폭, 수면경사, 수온)등의 자료를 이용하여 총유사량(미측정구간의 유사량 포함)을 추정(실측+계산: Modified Einstein)하였다. 총유사량 추정시, 세류사량을 제외한 부유사량을 적용하였다. 유량-부유사농도와 부유사량 및 총유사량 관계에 대한 결과는 다음과 같다: 1) 하나의 강우사상의 수위 상승-첨두-하강에 대한 측정성과는 대체적으로 Loop 형태를 보였고 이로 인해 일부 지점에서 측정성과들 간의 산포도가 다소 크게 나타났으며 수위 하강 때보다 상승시 초기 탁도의 증가 현상으로 부유사농도가 더 높은 것을 볼 수 있었다. 2) 유량-부유사농도, 부유사량, 총유사량 관계에서 왜관과 공주 지점의 경우, 첨두 수위에서 값들의 최고치를 보였고 나머지 지점들은 첨두 수위의 앞선 측정 수위에서 최고치를 보였다. 이는 강우사상별, 강우강도, 댐 방류량, 수위 상승-하강부, 유량에 따른 부유사농도와 부유사량의 특성이 각각 다른 점과 총유사량 추정시, 추정방법에서 추천하는 범위에서 벗어나는 자료를 적용해서 나타나는 결과로 판단된다. 여기서 유량, 수심, 하상토의 입도크기 등 자료의 범위가 추정공식들이 추천하는 범위에서 벗어나면 그 분석 결과도 서로 다르게 나타난다는 것은 그만큼 총유사량 공식의 범용성이 적다는 것을 의미한다. 이러한 점에서 때로는 자료 전체에 대해 전반적으로 양호한 결과를 보이는 공식보다는 정확한 답을 원하는 자료의 범위 내에서 예측하는 공식을 선정하는 것이 필요하다. 즉, 공식을 적용하여 유사량을 추정하고자 하는 하천이나 수로의 특성에 맞는 유사량 공식을 선정하는 것이 중요하다는 것이다.

• Journal of dental hygiene science
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• v.17 no.4
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• pp.283-289
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• 2017

The water discharged from dental unit waterlines (DUWLs) is heavily contaminated with bacteria. The development of efficient disinfectants is required to maintain good quality DUWL water. The purpose of this study was to establish a DUWL biofilm model using well-plates to confirm the effectiveness of disinfectants in the laboratory. Bacteria were obtained from the water discharged from DUWLs and incubated in R2A liquid medium for 10 days. The bacterial solution cultured for 10 days was made into stock and these stocks were incubated in R2A broth and batch mode for 5 days. Batch-cultured bacterial culture solution and polyurethane tubing sections were incubated in 12-well plates for 4 days. Biofilm accumulation was confirmed through plating on R2A solid medium. In addition, the thickness of the biofilm and the shape and distribution of the constituent bacteria were confirmed using confocal laser microscopy and scanning electron microscopy. The average accumulation of the cultured biofilm over 4 days amounted to $1.15{\times}10^7CFU/cm^2$. The biofilm was widely distributed on the inner surface of the polyurethane tubing and consisted of cocci, short-length rods and medium-length rods. The biofilm thickness ranged from $2{\mu}m$ to $7{\mu}m$. The DUWL biofilm model produced in this study can be used to develop disinfectants and study DUWL biofilm-forming bacteria.

• Korean Journal of Heritage: History & Science
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• v.52 no.2
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• pp.220-239
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• 2019

According to the National Currency (國幣) article in GyeongGukDaeJeon (經國大典), the ChoSonT'ongPaeJiIn (朝鮮通幣之印) was a seal that was imprinted on both ends of a piece of hemp fabric (布). It was used for the circulation of hemp fabric as a fabric currency (布幣). The issued fabric currency was used as a currency for trade or as pecuniary means to have one's crime exempted or replace one's labor duty. The ChoSonT'ongPaeJiIn would be imprinted on a piece of hemp fabric (布) to collect one-twentieth of tax. The ChoSonT'ongPaeJiIn (朝鮮通幣之印) was one of the historical currencies and seal materials used during the early Chosun dynasty. Its imprint was a means of collecting taxes; hence, it was one of the taxation research materials. Despite its value, however, there has been no active research undertaken on it. Thus, the investigator conducted comprehensive research on it based on related content found in JeonRokTongGo (典錄通考), Dae'JeonHu-Sok'Rok (大典後續錄), JeongHeonSwaeRok (貞軒?錄) and other geography books (地理志) as well as the materials mentioned by researchers in previous studies. The investigator demonstrated that the ChoSonT'ongPaeJiIn was established based on the concept of circulating Choson fabric notes (朝鮮布貨) with a seal on ChongOseungp'o (正五升布) in entreaty documents submitted in 1401 and that the fabric currency (布幣) with the imprint of the ChoSonT'ongPaeJiIn was used as a currency for trade, pecuniary or taxation means of having one's crime exempted, or replacing one's labor, and as a tool of revenue from ships. The use of ChoSonT'ongPaeJiIn continued even after a ban on fabric currencies (布幣) in March 1516 due to a policy on the "use of Joehwa (paper notes)" in 1515. It was still used as an official seal on local official documents in 1598. During the reign of King Yeongjo (英祖), it was used to make a military service (軍布) hemp fabric. Some records of 1779 indicate that it was used as a means of taxation for international trade. It is estimated that approximately 330 ChoSonT'ongPaeJiIn were in circulation based on records in JeongHeonSwaeRok (貞軒?錄). Although there was the imprint of ChoSonT'ongPaeJiIn in An Inquiry on Choson Currency (朝鮮貨幣考) published in 1940, there had been no fabric currencies (布幣) with its imprint on them or genuine cases of the seal. It was recently found among the artifacts of Wongaksa Temple. The seal imprint was also found on historical manuscripts produced at the Jikjisa Temple in 1775. The investigator compared the seal imprints found on the historical manuscripts of the Jikjisa Temple, attached to TapJwaJongJeonGji (塔左從政志), and published in An Inquiry on Choson Currency with the ChoSonT'ongPaeJiIn housed at the Wongaksa Temple. It was found that these seal imprints were the same shape as the one at Wongaksa Temple. In addition, their overall form was the same as the one depicted in Daerokji (大麓誌) and LiJaeNanGo (?齋亂藁). These findings demonstrate that the ChoSonT'ongPaeJiIn at Wongaksa Temple was a seal made in the 15th century and is, therefore, an important artifact in the study of Choson's currency history, taxation, and seals. There is a need for future research examining its various aspects.

• Food Science of Animal Resources
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• v.20 no.2
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• pp.159-165
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• 2000

Glycomacropeptide(GMP) was purified from cheese whey which is obtaining as a byproduct in cheese producing. Cheese whey was first concentrated 10 times with a ultrafiltration aparratus, and then heated at 95$^{\circ}C$ for 5 min. The concentrated fraction was centrifuged at 20,000$\times$g for 30 min to remove fat layer. The supernatant layer enriched GMP protein was fractionated by ion exchange chromatography on DEAE-Sepharose Fast Flow column. GMP was bound to DEAE resin and eluted with 0.1~0.25 M NaCl when using a linear NaCl gradient from 0 M to 0.5 M. The purified GMP gave a single band of 24 kDa which seems to be trimer molecular weight in SDS-PAGE, and migrated to the same molecular weight with control GMP obtained commercially. Its amino acid composition were consistent with that of standard GMP. About 0.71 g of GMP was recovered from 1 L of cheese whey. These results indicate that glycomacropeptide could be simply purified from cheese whey by using ultrafiltration and DEAE column chromatography.

• Korean Journal of Ecology and Environment
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• v.39 no.2 s.116
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• pp.271-283
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• 2006

A systematic water quality survey was conducted in August, 2005 for a drinking water supply reservoir (the Jeolgol reseuoir located in an island), which is at an early stage of impoundment, to investigate the causes of water color deterioration of the reservoir and the clogging of filter beds of a water treatment plant. The reservoir shape was simple and its average depth was 5.5 m, increasing from upreservoir toward the downreservoir end near the dam. Dissolved oxygen (DO) and chloropllyll-a (chi-a) showed a large variation while water temperature had a smaller range. Transparency ranged from 0.6 to 0.9 m (average 0.7 m). The average value of turbidity was 9.3 NTU, ranging from 8.0 ${\sim}$ 12.1 NTU. The transparency and the turbidity appear to be affected by a combination of biological and non-biological factors. The poor transparency was explained by an increase of inorganic colloids and algal bloom in the reservoir. The blockage of the filter bed was attributed to the oversupply of phytoplanktons from the reservoir. The range and the average concentration of chi-a within the reservoir were 31.6 ${\sim}$ 258.9 ${\mu}g\;L^{-1}$, 123.6 ${\mu}g\;L^{-1}$ for the upper layer, and 17.0 ${\sim}$ 37.4 ${\mu}g\;L^{-1}$, 26.5 ${\mu}g\;L^{-1}$ for the bottom layer, respectively. A predominant species contributing the algal bloom was Dinophyceae, Peridinium bipes f. occultatum. The distribution of Peridinium spp. was correlated with chi-a concentrations. The standing crop of phytoplankton was highest in the upreservoir with $8.5\;{\times}\;103\;cells\;mL^{-1}$ and it decreased toward the downresevoir. Synedra of Bacillariophyceae and Microcystis aeruginosa of Cyanophyceae appeared to contribute to the algal bloom, although they are not dominated. It is mostly likely that sloped farmlands located in the watershed of the reservoir caused water quality problems because they may contain a significant amount of the nutrients originated from fertilizers. In addition, the aerators installed in the reservoir and a shortage of the inflowing water may be related to the poor water quality. A long-term monitoring and an integrated management plan for the water quality of the watersheds and the reservoir may be required to improve the water quality of the reservoir.

• Journal of Radiation Protection and Research
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• v.28 no.3
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• pp.165-172
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• 2003

Humic acids present in the soils at the vicinity of domestic atomic power plants(NPPs), located in Yeongkwang(YK), Uljin(UJ), Kori(KR), Koseong(KS), Wolseong(WS) area were isolated, and characterized using elemental analysis and UV/Vis, IR, CPMAS $^{13}C$ NMR spectroscopic methods. The characteristics were compared with one another and with commercial humic acid (Aldrich Co.). Molecular size distributions of the humic acids were determined using a stirred cell ultrafiltration technique. The results of elemental analysis showed that soil humic acid from UJ contains higher oxygen content than humic acids from KR and KS (O/C ratios: 0.51 (UJHA) us. 0.45(KRHA), 0.43(KSHA)). The molecular size distribution revealed that the soil humic acids of UJ and YK contained a higher percentage of larger molecules of > 30,000 daltons, compared to those of KR and KS. The spectral features obtained from UV/vis., IR and CPMAS $^{13}C$ NMR showed that the aromatic character and oxygen containing functional groups in the humic acids from UJ and YK were relatively higher than those of KR and KS. These results indicate that the soil humic acids from UJ and YK were in a higher degree of humification, which may suggest higher affinity of the humic acids with radionuclides released in the soil environments.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.25 no.3
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• pp.95-99
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• 2019

In the modified atmosphere packaging of powdered infant formula, the oxygen inside the package may cause its quality deterioration and needs to be minimized for quality preservation. A way of oxygen scavenger inclusion in the single-serve package without contacting the product was devised for removing oxygen residing initially and permeating through the seal layer during the storage. A polyethylene/pulp multi-layer porous filter bag of 5 × 7 cm containing 13 g of powdered infant formula was packaged in an 8 × 9 cm size aluminium laminated film package with a Fe-based oxygen scavenger of 1.8 g. After nitrogen flushed packaging, the active packages were stored at 30℃ for 254 days with periodical quality measurement. The active package could remove the initial residual oxygen of 1.4% completely and maintain absence of oxygen for the whole storage, which contributed to reduced oxidation observed in lower product peroxide value compared to that of the product in the control package. There was no influence of packaging treatment on content of 5-hydroxymethylfurfural, reaction product of initial nonenzymatic browning. The devised oxygen-scavenging single-serve package showed a potential to improve the preservation of infant formula powder and extend the shelf life.